Identification, expression and DNA variation analysis of high affinity nitrate transporter NRT2/3 gene family in Sorghum bicolor / 生物工程学报

Nitrate is the main form of inorganic nitrogen that crop absorbs, and nitrate transporter 2 (NRT2) is a high affinity transporter using nitrate as a specific substrate. When the available nitrate is limited, the high affinity transport systems are activated and play an important role in the process of nitrate absorption and transport. Most NRT2 cannot transport nitrates alone and require the assistance of a helper protein belonging to nitrate assimilation related family (NAR2) to complete the absorption or transport of nitrates. Crop nitrogen utilization efficiency is affected by environmental conditions, and there are differences between varieties, so it is of great significance to develop varieties with high nitrogen utilization efficiency. Sorghum bicolor has high stress tolerance and is more efficient in soil nitrogen uptake and utilization. The S. bicolor genome database was scanned to systematically analyze the gene structure, chromosomal localization, physicochemical properties, secondary structure and transmembrane domain, signal peptide and subcellular localization, promoter region cis-acting elements, phylogenetic evolution, single nucleotide polymorphism (SNP) recognition and annotation, and selection pressure of the gene family members. Through bioinformatics analysis, 5 NRT2 gene members (designated as SbNRT2-1a, SbNRT2-1b, SbNRT2-2, SbNRT2-3, and SbNRT2-4) and 2 NAR2 gene members (designated as SbNRT3-1 and SbNRT3-2) were identified, the number of which was less than that of foxtail millet. SbNRT2/3 were distributed on 3 chromosomes, and could be divided into four subfamilies. The genetic structure of the same subfamilies was highly similar. The average value of SbNRT2/3 hydrophilicity was positive, indicating that they were all hydrophobic proteins, whereas α-helix and random coil accounted for more than 70% of the total secondary structure. Subcellular localization occurred on plasma membrane, where SbNRT2 proteins did not contain signal peptides, but SbNRT3 proteins contained signal peptides. Further analysis revealed that the number of transmembrane domains of the SbNRT2s family members was greater than 10, while that of the SbNRT3s were 2. There was a close collinearity between NRT2/3s of S. bicolor and Zea mays. Protein domains analysis showed the presence of MFS_1 and NAR2 protein domains, which supported executing high affinity nitrate transport. Phylogenetic tree analysis showed that SbNRT2/3 were more closely related to those of Z. mays and Setaria italic. Analysis of gene promoter cis-acting elements indicated that the promoter region of SbNRT2/3 had several plant hormones and stress response elements, which might respond to growth and environmental cues. Gene expression heat map showed that SbNRT2-3 and SbNRT3-1 were induced by nitrate in the root and stem, respectively, and SbNRT2-4 and SbNRT2-3 were induced by low nitrogen in the root and stem. Non-synonymous SNP variants were found in SbNRT2-4 and SbNRT2-1a. Selection pressure analysis showed that the SbNRT2/3 were subject to purification and selection during evolution. The expression of SbNRT2/3 gene and the effect of aphid infection were consistent with the expression analysis results of genes in different tissues, and SbNRT2-1b and SbNRT3-1 were significantly expressed in the roots of aphid lines 5-27sug, and the expression levels of SbNRT2-3, SbNRT2-4 and SbNRT3-2 were significantly reduced in sorghum aphid infested leaves. Overall, genome-wide identification, expression and DNA variation analysis of NRT2/3 gene family of Sorghum bicolor provided a basis for elucidating the high efficiency of sorghum in nitrogen utilization.

Environmental exposure to perchlorate, nitrate, and thiocyanate in relation to chronic kidney disease in the general US population, NHANES 2005-2016 / 中华医学杂志(英文版)

BACKGROUND@#Few studies have explored the impact of perchlorate, nitrate, and thiocyanate (PNT) on kidney function. This study aimed to evaluate the association of urinary levels of PNT with renal function as well as the prevalence of chronic kidney disease (CKD) among the general population in the United States.@*METHODS@#This analysis included data from 13,373 adults (≥20 years) from the National Health and Nutrition Examination Survey 2005 to 2016. We used multivariable linear and logistic regression, to explore the associations of urinary PNT with kidney function. Restricted cubic splines were used to assess the potentially non-linear relationships between PNT exposure and outcomes.@*RESULTS@#After traditional creatinine adjustment, perchlorate (P-traditional) was positively associated with estimated glomerular filtration rate (eGFR) (adjusted β: 2.75; 95% confidence interval [CI]: 2.25 to 3.26; P  < 0.001), and negatively associated with urinary albumin-to-creatinine ratio (ACR) (adjusted β: -0.05; 95% CI: -0.07 to -0.02; P  = 0.001) in adjusted models. After both traditional and covariate-adjusted creatinine adjustment, urinary nitrate and thiocyanate were positively associated with eGFR (all P values <0.05), and negatively associated with ACR (all P values <0.05); higher nitrate or thiocyanate was associated with a lower risk of CKD (all P values <0.001). Moreover, there were L-shaped non-linear associations between nitrate, thiocyanate, and outcomes. In the adjusted models, for quartiles of PNT, statistically significant dose-response associations were observed in most relationships. Most results were consistent in the stratified and sensitivity analyses.@*CONCLUSIONS@#Exposures to PNT might be associated with kidney function, indicating a potential beneficial effect of environmental PNT exposure (especially nitrate and thiocyanate) on the human kidney.

Construction and biological characterization of a Proteus mirabilis strain with modABC gene deletion / 南方医科大学学报

OBJECTIVE@#To construct a modABC gene knockout strain of Proteus mirabilis and explore the effect of modABC gene deletion on biological characteristics of Proteus mirabilis.@*METHODS@#Fusion PCR was used to obtain the fusion gene of modABC and the kanamycin-resistant gene Kn, which was ligated with the suicide vector pCVD442 and transduced into Proteus mirabilis. The modABC gene knockout strain of Proteus mirabilis was obtained after homologous recombination with the suicide vector. PCR and Sanger sequencing were used to identify genomic deletion of modABC gene in the genetically modified strain. The concentration of molybdate in the wild-type and gene knockout strains was determined using inductively coupled plasma mass spectrometry (ICP-MS), and their survival ability in LB medium was compared under both aerobic and anaerobic conditions.@*RESULTS@#PCR and sanger sequencing confirmed genomic deletion of modABC gene in the obtained Proteus mirabilis strain. The concentration of intracellular molybdenum in the modABC gene knockout strain was 1.22 mg/kg, significantly lower than that in the wild-type strain (1.46 mg/kg, P < 0.001). Under the aerobic condition, the modABC gene knockout strain grown in LB medium showed no significant changes in survival ability compared with the wild-type strain, but its proliferation rate decreased significantly under the anaerobic condition and also when cultured in nitrate-containing LB medium under anaerobic condition.@*CONCLUSION@#Homologous recombination with the suicide vector can be used for modABC gene knockout in Proteus mirabilis. modABC gene participates in molybdate uptake and is associated with anaerobic growth of Proteus mirabilis in the presence of nitrate.

Homeostatic medicine: new strategy and concept of health maintenance as well as diagnosis and treatment of diseases / 中华口腔医学杂志

Homeostasis is a dynamic balance process of self-regulating. Biological systems remain stable through adapting to changing external conditions to maintain normal life activities. Homeostatic medicine is the science of studying homeostasis of human molecules, cells, organs and the whole body. It is a comprehensive discipline based on maintaining homeostasis to keep human health and assist for diseases prevention and diagnoses. Homeostatic medicine focuses on the whole body and on the role of homeostasis in health and disease, which is expected to provide new ideas and strategies for maintaining health as well as diagnosing and treating diseases. Nitric oxide (NO) plays an important role in the control of multisystem homeostasis. Nitrate is an important substance in regulating NO homeostasis through the nitrate-nitrite-NO pathway. Sialin, nitrate transporter which is located in the cell membrane and cytoplasm, mediates multiple cellular biological functions. The nitrate-nitrite-NO pathway and sialin-mediated biological functions play an important role in the regulation of body homeostasis.

Cardiopatía isquémica. Consideraciones para la atención odontológica / Ischemic heart disease. Considerations for dental treatment

La cardiopatía isquémica es un padecimiento que se caracteriza por la falta de oxígeno del músculo cardiaco y es la principal causa de infarto de miocardio. Existen múltiples factores que predisponen al desarrollo de ésta como la obesidad, la hiperlipidemia, el sedenta- rismo, tabaquismo, diabetes e hipertensión. Dadas las características que configuran la fisiopatología de la cardiopatía isquémica, existen diversas consideraciones que deben ser tomadas en cuenta toda vez que el estomatólogo brinde atención a un paciente con este padecimiento. El objetivo del presente artículo es conocer todo lo relacionado con la fisiopatología de la cardiopatía isquémica, sus manifestaciones clínicas, su tratamiento médico y lo más importante, las consideraciones que deben tomarse en el consultorio dental cuando se atienda a un paciente que padezca esta condición (AU)

Ischemic heart disease is a condition characterized by a lack of oxygen in the heart muscle and is the main cause of myocardial infarction. There are multiple factors that predispose to the development of this, such as obesity, hiyperlipidemia, sedentary lifestyle, smoking, diabetes and hypertension. Given the characteristics that make up the pathophysiology of ischemic heart disease, there are various considerations that must be taken into account whenever the stomatologist provides care to a patient with this condition. The objective of this article is to know everything related to the pathophysiology of ischemic heart disease, its clinical manifestation, its medical treatment and most importantly, the considerations that must be taken in the dental office when caring for a patient with this condition (AU)

Ionic homeostasis, biochemical components and yield of Italian zucchini under nitrogen forms and salt stress / Homeostase iônica, componentes bioquímicos e produção da abobrinha italiana sob formas de nitrogênio e estresse salino

This research was carried out aiming at evaluating the effects of nitrate and ammonium ions on nutrient accumulation, biochemical components and yield of Italian zucchini (cv. Caserta) grown in a hydroponic system under salt stress conditions. The experiment was carried out in a greenhouse utilizing an experimental design in randomized blocks, arranged in a 2 x 5 factorial scheme, with 4 replications. The treatments consisted of two forms of nitrogen (nitrate - NO3 - and ammonium - NH4 + ) and 5 electrical conductivity levels of irrigation water (ECw) (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1). The analysis of the results indicated that supply of N exclusively in NH4 + form promotes greater damage to the leaf membrane and reduction in accumulation of macronutrients and higher Na+ /K+ , Na+ /Ca++ and Na+ /Mg++ ratios in the shoots of zucchini plants. Electrical conductivity of irrigation water above 2.0 dS m-1 reduces the accumulation of nutrients in shoot and yield of Italian zucchini plant. The toxicity of NH4 + under Italian zucchini plants overlap the toxicity of the salinity, since its fertilization exclusively with this form of nitrogen inhibits its production, being the NO3 - form the most suitable for the cultivation of the species.

Este trabalho foi desenvolvido com o objetivo de avaliar os efeitos dos íons nitrato e amônio sobre o acúmulo de nutrientes e produção da abobrinha italiana (cv. Caserta) cultivada em sistema hidropônico sob estrese salino. O experimento foi conduzido em casa de vegetação utilizando o delineamento experimental em blocos casualizados, arranjados em esquema fatorial 2 x 5, com 4 repetições. Os tratamentos foram constituídos de duas formas de nitrogênio (nitrato - NO3 - e amônio - NH4 + ) e cinco níveis de condutividade elétrica da água de irrigação (CEa ) (0,5; 2,0; 3,5; 5,0 e 6,5 dS m-1). As análises dos resultados indicaram que suprimento de N exclusivamente em forma de NH4 + promove maiores danos na membrana foliar e redução no acúmulo de macronutrientes e maiores relações Na+ /K+ , Na+ /Ca++ e Na+ /Mg++ na parte aérea das plantas de abobrinha. A irrigação com água a cima de 2,0 dS m-1 reduz o acúmulo de nutrientes na parte aérea das plantas e a produção de abobrinha. A toxicidade do NH4 + sob abobrinha italiana sobrepõe-se à toxicidade da salinidade, pois a fertilização exclusiva com esta forma de nitrogênio inibe sua produção, sendo a forma NO3 - a mais adequada para o cultivo da espécie.

A Physiological behavior and tolerance of Lactuca sativa to lead nitrate and silver nitrate heavy metals / Comportamento fisiológico e tolerância de Lactuca sativa aos metais pesados nitrato de chumbo e nitrato de prata

This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.

Este estudo teve como objetivo avaliar os efeitos de diferentes concentrações de chumbo (Pb) e prata (Ag) na germinação, crescimento inicial e alterações anatômicas de Lactuca sativa L. As plantas utilizam vários mecanismos para reduzir os impactos causados pela ação antrópica, como elementos xenobióticos de solos e água contaminada por metais pesados. Esses metais foram fornecidos como nitrato de chumbo e nitrato de prata e foram estabelecidos os seguintes tratamentos: controle para ambos os metais, dose máxima de metais pesados, para solos cultiváveis, permitida pelo Conselho Nacional do Meio Ambiente (Ag = 25mg.Kg-1, Pb = 180mg.Kg-1), dobro (Ag = 50mg.Kg-1, Pb = 360mg.Kg-1) e triplo (Ag = 75mg.Kg-1, Pb = 540 mg.Kg -1) desta dosagem. Foram realizados testes de vigor e germinação das sementes e possíveis alterações anatômicas nas folhas e raízes das plantas de alface. A espécie apresentou alta capacidade de germinar sob estresse de Ag e Pb, e a germinação nunca foi completamente inibida; entretanto, a germinação diminuiu com o aumento das concentrações de Pb, mas não sob estresse de Ag. O uso de doses crescentes dos metais, reduziu o vigor das sementes e aumentou o teor de clorofila. Também foi observado aumento da biomassa nas plantas a partir dos tratamentos submetidos ao Pb. Os efeitos fitotóxicos dos metais foram mais acentuados aos 15 dias após a semeadura. Anatomicamente, L. sativa foi influenciada pelas concentrações de metais, e teve uma redução de até 79,9% na espessura da epiderme radicular na maior concentração de Pb, embora algumas estruturas não tenham sofrido alterações significativas. Os resultados sugerem que L. sativa apresenta tolerância a altas concentrações de metais pesados, mostrando possíveis mecanismos para superar o estresse causado por esses metais. Nesta pesquisa a alface possivelmente utilizou o mecanismo de exclusão de metais retendo Pb e Ag nas raízes preservando o aparato fotossintético na parte aérea das plantas. De forma geral o elemento químico Pb se mostrou mais tóxico que Ag, nestas condições experimentais.

Clinical and toxicological findings in nitrate and nitrite poisoning in cattle in Northeastern Brazil / Achados clínicos e toxicológicos na intoxicação por nitrato e nitrito em bovinos no Nordeste do Brasil

We report two outbreaks of nitrate and nitrite poisoning in Paraíba, Northeast Brazil. The first, due to Pennisetum purpureum (elephant grass), and the second, due to P. purpureum and Brachiaria spp. (brachiaria grass), both occurred during a prolonged drought. In the first outbreak, the irrigation of the pastures with wastewater and sewage contributed to nitrate accumulation. The second outbreak occurred in pastures cultivated in the border of a dam, that had been submerged for long time accumulating large amounts of organic matter in the soil. Other probably risk factors for nitrate accumulation included the use of chemical fertilizers and herbicides and burning of the vegetation. In the first outbreak, four calves out of a total of 42 cattle died, and in the second outbreak 49 out of 243 cattle, including adults, yearlings, and a 2-day-old calf died. The clinical signs included dyspnea, cyanosis, ataxia, and falls, leading to death. The presence of nitrates was detected in both outbreaks using the diphenylamine test. Quantitative tests were performed in the second outbreak using a portable nitrate meter, and high nitrate concentrations were found. The characteristic macroscopic findings and absence of microscopic lesions and response to treatment with methylene blue were key to the diagnosis of poisoning by nitrates and nitrites. We conclude that poisoning by nitrates and nitrites in ruminants in the semiarid region of Northeastern Brazil is frequent due to the cultivation of grasses in the border of dams that had been covered by water for long periods or in areas irrigated by wastewater and/or sewage. In addition, the use of a portable measuring device is an effective alternative for the quantification of nitrates in pastures.(AU)

Relatamos dois surtos de intoxicação por nitrato e nitrito na Paraíba, Nordeste do Brasil. O primeiro por Pennisetum purpureum (capim-elefante), e o segundo por P. purpureum e Brachiaria spp. (capim braquiária); ambos ocorreram durante uma estiagem prolongada. No primeiro surto, a irrigação das pastagens com água poluída e esgoto contribuiu para o acúmulo de nitrato. O segundo surto ocorreu em pastagens cultivadas na borda de uma barragem, que há muito tempo ficavam submersas, acumulando grande quantidade de matéria orgânica no solo. Outros prováveis fatores de risco para o acúmulo de nitrato incluíram o uso de fertilizantes químicos e herbicidas e a queima da vegetação. No primeiro surto, quatro bezerros de um total de 42 bovinos morreram, e no segundo surto 49 de 243 bovinos, incluindo adultos, jovens de um ano e um bezerro de 2 dias de idade morreram. Os sinais clínicos incluíram dispneia, cianose, ataxia e quedas, levando à morte. A presença de nitratos foi detectada em ambos os surtos pelo teste de difenilamina. Testes quantitativos foram realizados no segundo surto usando um medidor portátil de nitrato, e altas concentrações de nitrato foram encontradas. Os achados macroscópicos característicos e a ausência de lesões microscópicas e a resposta ao tratamento com azul de metileno foram fundamentais para o diagnóstico de intoxicação por nitratos e nitritos. Concluímos que a intoxicação por nitratos e nitritos em ruminantes na região semiárida do Nordeste do Brasil é frequente devido ao cultivo de gramíneas nas bordas de barragens que estiveram cobertas por água por longos períodos ou em áreas irrigadas por água poluída e/ou esgoto. Além disso, o uso de medidor portátil é uma alternativa eficaz para a quantificação de nitratos em pastagens.(AU)

Clinical and toxicological findings in nitrate and nitrite poisoning in cattle in Northeastern Brazil / Achados clínicos e toxicológicos na intoxicação por nitrato e nitrito em bovinos no Nordeste do Brasil

We report two outbreaks of nitrate and nitrite poisoning in Paraíba, Northeast Brazil. The first, due to Pennisetum purpureum (elephant grass), and the second, due to P. purpureum and Brachiaria spp. (brachiaria grass), both occurred during a prolonged drought. In the first outbreak, the irrigation of the pastures with wastewater and sewage contributed to nitrate accumulation. The second outbreak occurred in pastures cultivated in the border of a dam, that had been submerged for long time accumulating large amounts of organic matter in the soil. Other probably risk factors for nitrate accumulation included the use of chemical fertilizers and herbicides and burning of the vegetation. In the first outbreak, four calves out of a total of 42 cattle died, and in the second outbreak 49 out of 243 cattle, including adults, yearlings, and a 2-day-old calf died. The clinical signs included dyspnea, cyanosis, ataxia, and falls, leading to death. The presence of nitrates was detected in both outbreaks using the diphenylamine test. Quantitative tests were performed in the second outbreak using a portable nitrate meter, and high nitrate concentrations were found. The characteristic macroscopic findings and absence of microscopic lesions and response to treatment with methylene blue were key to the diagnosis of poisoning by nitrates and nitrites. We conclude that poisoning by nitrates and nitrites in ruminants in the semiarid region of Northeastern Brazil is frequent due to the cultivation of grasses in the border of dams that had been covered by water for long periods or in areas irrigated by wastewater and/or sewage. In addition, the use of a portable measuring device is an effective alternative for the quantification of nitrates in pastures.

Relatamos dois surtos de intoxicação por nitrato e nitrito na Paraíba, Nordeste do Brasil. O primeiro por Pennisetum purpureum (capim-elefante), e o segundo por P. purpureum e Brachiaria spp. (capim braquiária); ambos ocorreram durante uma estiagem prolongada. No primeiro surto, a irrigação das pastagens com água poluída e esgoto contribuiu para o acúmulo de nitrato. O segundo surto ocorreu em pastagens cultivadas na borda de uma barragem, que há muito tempo ficavam submersas, acumulando grande quantidade de matéria orgânica no solo. Outros prováveis fatores de risco para o acúmulo de nitrato incluíram o uso de fertilizantes químicos e herbicidas e a queima da vegetação. No primeiro surto, quatro bezerros de um total de 42 bovinos morreram, e no segundo surto 49 de 243 bovinos, incluindo adultos, jovens de um ano e um bezerro de 2 dias de idade morreram. Os sinais clínicos incluíram dispneia, cianose, ataxia e quedas, levando à morte. A presença de nitratos foi detectada em ambos os surtos pelo teste de difenilamina. Testes quantitativos foram realizados no segundo surto usando um medidor portátil de nitrato, e altas concentrações de nitrato foram encontradas. Os achados macroscópicos característicos e a ausência de lesões microscópicas e a resposta ao tratamento com azul de metileno foram fundamentais para o diagnóstico de intoxicação por nitratos e nitritos. Concluímos que a intoxicação por nitratos e nitritos em ruminantes na região semiárida do Nordeste do Brasil é frequente devido ao cultivo de gramíneas nas bordas de barragens que estiveram cobertas por água por longos períodos ou em áreas irrigadas por água poluída e/ou esgoto. Além disso, o uso de medidor portátil é uma alternativa eficaz para a quantificação de nitratos em pastagens.

Identification and analysis of 2 Corynebacterium diphtheria strains in Guangdong Province / 中华预防医学杂志

Objective: To identify and analyze two strains of C. diphtheriae in Guangdong Province by combining whole genome sequencing with traditional detection methods. Methods: The C. diphtheriae was isolated from Guangzhou in 2010 and Zhuhai in 2020 respectively. Isolates were identified by API Coryne strips and MALDI-TOF-MS. Genomic DNA was sequenced by using Illumina. The assembly was performed for each strain using CLC software. J Species WS online tool was used for average nucleoside homology identification, then narKGHIJ and tox gene were detected by NCBI online analysis tool BLSATN. MEGA-X was used to build a wgSNP phylogenetic tree. Results: GD-Guangzhou-2010 was Belfanti and GD-Zuhai-2020 was Gravis. ANIb between GD-Guangzhou-2010 and C. belfantii was 99.61%. ANI between GD-Zhuhai-2020 and C. diphtheriae was 97.64%. BLASTN results showed that the nitrate reduction gene narKGHIJ and tox gene of GD-Guangzhou-2010 was negative, while GD-Zhuhai-2020 nitrate reduction gene narKGHIJ was positive. There were two obvious clades in wgSNP phylogenetic tree. The first clades included all Mitis and Gravis types strains as well as GD-Zhuhai-2020. The second clades contained all isolates of C.belfantii, C.diphtheriae subsp. lausannense and GD-guangzhou-2010. Conclusion: Two non-toxic C. diphtheriae strains are successfully isolated and identified. The phylogenetic tree suggests that GD-Guangzhou-2010 and GD-Zhuhai-2020 are located in two different evolutionary branches.

Calidad del aire interior mediante indicadores ecológicos y sociales asociados a la inmisión de material particulado (PM10) en la zona este 2 / Indoor air quality through ecological and social indicators associated with the immission of particulate matter (PM10) in the eastern zone 2

El material particulado (PM) es uno de los contaminantes más importantes presentes en el aire, representando un riesgo medioambiental para la salud. Las partículas con un diámetro de 10 micrones o menos (PM10), al ser inhalables, pueden penetrar y alojarse profundamente en los pulmones, contribuyendo al riesgo de desarrollar enfermedades cardiovasculares y respiratorias, así como cáncer de pulmón, enfermedades mentales, dermatitis, daño ocular e incluso al aumento en las tasas de mortalidad. Se estableció como objetivo determinar la calidad del aire interior asociada a la inmisión de material particulado (PM10) en la zona este 2, un sector industrial ubicado en los distritos san juan de Lurigancho y Lurigancho-Chosica, Perú. Para tal fin, se propone el uso de indicadores duales: ecológicos y sociales. De acuerdo a los indicadores ecológicos explorados, la concentración media de PM10 en el aire exterior (CME) superó el límite de 100 µg/m3 establecido por MINAM. Aunque la mediana de CME (93,7µg/m3; IC 95%=89,07-98,33) estuvo por debajo de este límite, el cuartil superior lo superó, entendido por elevaciones puntuales de hasta 131 µg/m3 (Figura 2), potencialmente dañinos para la salud humana. El coeficiente de correlación de Spearman de 0,921, obtenido del análisis bivariado entre los valores de concentración media diaria de PM10 exterior e interior, previo a la instalación de filtros en los sistemas de ventilación, es sugerente del efecto que puede tener la inmisión de aire ambiental con material particulado como vector de la contaminación del aire interior. al considerar los valores de la concentración media diaria, obtenidos en los 15 días posteriores a la instalación de los filtros (CMIFI), se observa que la concentración media de PM10 en el interior disminuyó en relación a la quincena anterior. El coeficiente de correlación de Spearman de 0,869 entre los indicadores CMIFI y CME, permite proponer que, en esta segunda fase, la calidad del aire interior fue influenciada en menor proporción por la contaminación de material particulado del aire ambiental, es decir que se presentó menos inmisión de PM10, gracias al proceso de filtrado, lo que disminuye el riesgo para la salud de los trabajadores(AU)

Particulate matter (PM) is one of the most important pollutants present in the air, representing an environmental risk to health. Particles with a diameter of 10 microns or less (PM10), being inhalable, can penetrate and lodge deep in the lungs, contributing to the risk of developing cardiovascular and respiratory diseases, as well as lung cancer, mental illness, dermatitis, eye damage and even increased mortality rates. The objective was to determine the indoor air quality associated with the immission of particulate matter (PM10) in East Zone 2, an industrial sector located in the districts of San Juan de Lurigancho and Lurigancho-Chosica, Peru. To this end, the use of dual indicators is proposed: ecological and social. According to the ecological indicators explored, the average concentration of PM10 in outdoor air (CME) exceeded the limit of 100 µg/m3 established by MINAM. Although the CME median (93.7µg/m3; 95% CI=89.07-98.33) was below this limit, the upper quartile exceeded it, understood as point elevations of up to 131µg/m3 (Figure 2 ), potentially harmful to human health. Spearman's correlation coefficient of 0.921, obtained from the bivariate analysis between the daily average concentration values of outdoor and indoor PM10, prior to the installation of filters in the ventilation systems, is suggestive of the effect that the immission of ambient air can have with particulate matter as a vector of indoor air pollution. When considering the values of the average daily concentration, obtained in the 15 days after the installation of the filters (CMIFI), it is observed that the average concentration of PM10 in the interior decreased in relation to the previous fortnight. Spearman's correlation coefficient of 0.869 between the CMIFI and CME indicators allows us to propose that, in this second phase, indoor air quality was influenced to a lesser extent by particulate matter contamination in the ambient air, that is, there was less PM10 immission, thanks to the filtering process, which reduces the risk to the health of workers(AU)

Water quality in the Lachuá Ecoregion Landscape: Comparing streams from Forest, Milpa, and an Oil Palm plantation / Calidad del agua en el paisaje de la Ecorregión Lachuá: Comparando arroyos en bosques, milpa y palma africana

The hydrological network in the Lachuá Ecoregion (EL), Alta Verapaz, Guatemala, hosts high levels of biodiversity and supplies water to 44 Mayan communities. Despite this critical fact, this network has been threatened by scarcely monitored industrial activities including the rapidly expanding oil palm monoculture (Elaeis guineensisJacq). Regardless of Lachua's freshwaters importance, there is little information on how this monoculture impacts them. We compared water-quality properties from streams in oil palm plantations (P), paddock and milpa systems (M), and primary forests (F) in the EL. During 2015-2016, 13 rivers were sampled (5 times) for water temperature, pH, dissolved oxygen (DO), conductivity, hardness, chemical and biochemical oxygen demand (COD and BOD), and concentration of silica, nitrates, phosphates, and ammonia. Several parameters showed significant differences. P were 2.7 ºC and 1.8 ºC warmer than M and F and carried 1.4 mg/L more nitrates than F. F carried 10.8 mg/L and 11.8 mg/L more silica than M and P. M showed intermediate temperatures and silica concentrations, as well as 14.8 µS/cm and 8.9 µS/cm lower conductivities than P and F, respectively. Additionally, COD in M was 9.9 mg/L and 4.6 mg/L lower than P and F, respectively. We believe higher temperatures and lower silica in P are due to the loss of riparian forest and their role in buffering temperatures and recycling silicon. In addition, the existence of secondary forest (guamil) in M might explain the intermediate temperatures and silica concentrations. Our results highlight the contributions of forests to waterways and suggest potential water-quality depletion from the oil palm expansion in the EL.

La red hídrica en la Ecorregión Lachuá (EL), Alta Verapaz, Guatemala, alberga una alta biodiversidad y abastece de agua a 44 comunidades mayas. Sin embargo, recientemente se ha visto amenazada por actividades industriales escasamente monitoreadas, incluido el creciente monocultivo de palma africana (Elaeis guineensis Jacq) del cual se desconocen sus impactos en la EL. Este estudio explora la calidad del agua de arroyos en plantaciones de palma africana (P), bosques primarios (B), y sistemas de potrero y milpa (M) en Lachuá. Durante 2015-2016, se tomaron muestras de 13 ríos (5 veces) para medir la temperatura del agua, pH, oxígeno disuelto (OD), conductividad, dureza, demanda química y bioquímica de oxígeno (DQO y DBO) y la concentración de sílice, nitratos, fosfatos, y amoníaco. Varios parámetros mostraron diferencias significativas. P fue 2.7 ºC y 1.8 ºC más calientes que M y F y portó 1.4 mg/L más nitrato que F. F portó 10.8 mg/L y 11.8 mg/L más sílice que M y P. M mostró temperaturas y concentraciones de sílice intermedias y conductividades 14.8 µS/cm y 8.9 µS/cm menores que P y F. La DQO en M fue 9.9 mg/L y 4.6 mg/L menor que P y F. El aumento de temperatura y la disminución de sílice en P podría deberse a la pérdida de bosques ribereños los cuales amortiguan la tempe-ratura y reciclan el silicio. La presencia de bosque secundarios (guamil) en M podría explicar las temperaturas y las concentraciones de sílice intermedias resaltando la importancia de los bosques en la red hídrica. Se predice un posible deterioro en el agua resultado de la expansión de palma africana en la EL.

Removal of nutrients from Organic Liquid Agricultural Waste using filamentous algae / Remoção de nutrientes de Resíduos Agrícolas Líquidos Orgânicos utilizando algas filamentosas

Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.

Resumo Uma análise de viabilidade do tratamento terciário para Resíduos Agrícola Líquidos Orgânicos é apresentada usando algas filamentosas pertencentes ao gênero Cladophora sp. como alternativa ao tratamento químico terciário. Os tratamentos terciários que utilizam sistemas biológicos têm baixo custo de investimento e a dependência de variáveis ​​ambientais é mínima. Neste trabalho, é demonstrado que essas algas filamentosas reduzem a carga nutricional de nitrato (circa 75%) e fosfato (circa 86%) dos efluentes de resíduos orgânicos provenientes de fazendas de leite em nove dias de cultura e tem a vantagem de que as algas podem ser facilmente coletadas posteriormente. Atualmente, as águas residuais orgânicas são descartadas nos campos e córregos locais. Posteriormente, as algas podem ser consideradas como matéria prima, uma vez que possuem várias utilidades como composto, celulose e biogás. Uma desvantagem desse sistema é que água limpa deve ser usada para obter transparência de água suficiente para permitir o crescimento de algas. Mesmo assim, o sistema de redução de nutrientes dos efluentes orgânicos propostos e amigável ao ecossistema, comparado aos tratamentos terciários que utilizam produtos químicos para precipitar e coletar nutrientes como nitratos e fosfatos.

Identification and expression analysis of NRT1 family genes in Rehmannia glutinosa / 中国中药杂志

NRT1 family proteins play an important roles for absorbing and transporting of nitrate in different plants. In order to identify the NRT1 family genes of Rehmannia glutinosa, this study used 11 NRT1 homologous proteins of Arabidopsis as probe sequences and aligned with the transcriptome data of R. glutinosa by using NCBI BLASTN software. Resulting there were 18 NRT1 proteins were identified in R. glutinosa. On basis of this, a series of the molecular characteristics of R. glutinosa NRT1 proteins including the conserved domains, the transmembrane structure, the subcellular location and phylogenetic features were in detail analyzed. At same time, it were systematically analyzed that the temporal and spatial expression patterns and characteristics of R. glutinosa NRT1 family genes in response to different stress factors. The results indicated that 18 R. glutinosa NRT1 family genes with the length of coding region from 1 260 bp to 1 806 bp, encoded proteins ranging from 419 to 601 amino acids, and all of they owned the domains of typical peptide transporter with 7 to 12 transmembrane domains. These R. glutinosa NRT1 family proteins mostly were found to locate on cellular plasma membrane, and belonged to the hydrophobic proteins. Furthermore, the evolutionary analysis found that the 18 R. glutinosa NRT1 protein family could be divided into two subfamilies, of which 14 NRT1 family genes might occur the positive selection, and 4 genes occur the passivation selection during the evolution process of R. glutinosa. In addition the expression analysis showed that 18 R. glutinosa NRT1 family genes have the distinct expression patterns in different tissues of R. glutinosa, and their expression levels were also obvious difference in response to various stress. These findings infield that 18 R. glutinosa NRT1 family proteins might have obviously different functional roles in nitrate transport of R. glutinosa. In conclusion, this study lays a solid theoretical foundation for clarifying the absorption and transport molecular mechanism of N element during R. glutinosa growth and development, and at same time for deeply studying the molecular function of R. glutinosa NRT1 proteins in absorption and transport of nitrate.

Effects of Fe₃O₄ on the denitrification performance of Pseudomonas stutzeri / 生物工程学报

Biological denitrification is the most widely used technology for nitrate removal in wastewater treatment. Conventional denitrification requires long hydraulic retention time, and the nitrate removal efficiency in winter is low due to the low temperature. Therefore, it is expected to develop new approaches to enhance the denitrification process. In this paper, the effect of adding different concentrations of Fe₃O₄ nanoparticles on the denitrification catalyzed by Pseudomonas stutzeri was investigated. The maximum specific degradation rate of nitrate nitrogen improved from 18.0 h⁻¹ to 23.7 h⁻¹ when the concentration of Fe₃O₄ increased from 0 mg/L to 4 000 mg/L. Total proteins and intracellular iron content also increased along with increasing the concentration of Fe₃O₄. RT-qPCR and label-free proteomics analyses showed that the relative expression level of denitrifying genes napA, narJ, nirB, norR, nosZ of P. stutzeri increased by 55.7%, 24.9%, 24.5%, 36.5%, 120% upon addition of Fe₃O₄, and that of denitrifying reductase Nap, Nar, Nir, Nor, Nos increased by 85.0%, 147%, 16.5%, 47.1%, 95.9%, respectively. No significant difference was observed on the relative expression level of denitrifying genes and denitrifying reductases between the bacteria suspended and the bacteria adhered to Fe₃O₄. Interestingly, the relative expression level of electron transfer proteins of bacteria adhered to Fe₃O₄ was higher than that of the bacteria suspended. The results indicated that Fe₃O₄ promoted cell growth and metabolism through direct contact with bacteria, thereby improving the denitrification. These findings may provide theoretical support for the development of enhanced denitrification.

Pediatric patients head-up-tilt-test with pharmacological challenge, it is safe? / Mesa inclinada en pacientes pediátricos con reto farmacológico, ¿es seguro?

Abstract Syncope in pediatrics represents an important cause of visits to the emergency units. For this reason, excluding a cardiac or malignant origin is essential at the time of the initial approach to determine what is the next step in management, or if they need to be referred to a pediatric cardiologist and/or electrophysiologist. Vasovagal syncope is the most frequent cause of syncope in pediatrics, in which a detailed clinical history is enough to make the diagnosis. If no diagnosis is concluded by the history, or if it is necessary to define the hemodynamic response of the patients, the head-up-tilt-test is indicated; this will trigger syncope due to an orthostatic stress caused by the angulated table (passive phase). If a negative response remains, it can be followed by a pharmacologic challenge to trigger the hemodynamic response, which is still controversial in pediatrics. The pharmacologic challenge increases the sensitivity with a slight reduction in test specificity. Although there is not a specific drug for the challenge in pediatric patients yet, the most commonly drugs used are nitrates and isoproterenol, the latter related to a great number of adverse effects. Sublingual administration of nitrates in the challenge has been proven to be ideal, effective, and safe in this specific age group. The aim of this article is to make a literature search to demonstrate the effectiveness and safety of the pharmacologic challenge during the head-up-tilt-test in pediatrics, emphasizing a study conducted at the National Institute of Cardiology with isosorbide dinitrate.

Resumen El síncope en edades pediátricas representa una causa importante en las visitas a unidades de urgencias, por lo que excluir un origen cardíaco o maligno es fundamental al momento del abordaje inicial para determinar la conducta a seguir o la necesidad de derivar al cardiólogo pediatra o electrofisiólogo. El síncope vasovagal (SVV) es la causa más frecuente de síncope en pediatría, para cuyo diagnóstico basta una historia clínica detallada. Cuando ésta no es suficiente para determinar el diagnóstico de síncope reflejo o es necesario definir el tipo de respuesta que lo origina, está indicada una prueba de mesa inclinada que produce un estrés ortostático por la angulación y ello desencadena un síncope (fase pasiva). En pruebas no concluyentes está indicado un reto farmacológico para precipitar la respuesta hemodinámica, pero aún es un tema de controversia en edades pediátricas. El reto farmacológico incrementa la sensibilidad de la prueba, con una ligera reducción de la especificidad. Si bien no existe todavía un medicamento específico para la población pediátrica, los más empleados son los nitratos y el isoproterenol, este último relacionado con un mayor número de efectos adversos. La administración sublingual de los nitratos utilizados ha demostrado ser ideal, efectiva y segura en los pacientes pediátricos. El objetivo del artículo es realizar una revisión de las publicaciones médicas que demuestran la efectividad y seguridad del reto farmacológico durante la prueba de mesa inclinada en pacientes pediátricos, con énfasis en un estudio conducido en el Instituto Nacional de Cardiología con dinitrato de isosorbida (DNIS).

Avaliação da contaminação de nitrato e Escherichia coli em água subterrânea no município de Carapicuiba (SP) / Evaluation of nitrate and Escherichia coli contamination on groundwater in the city of Carapicuiba (SP)

Objetivo ­ Verificar a concentração de nitrato e a presença ou ausência de bactérias da espécie Escherichia coli em amostras de água subterrânea (poços) destinadas ao consumo humano e comparar os resultados aos Valores Máximos Permitidos (VMP) pela Portaria 2.914 do Ministério da Saúde. Métodos ­ Durante um ano (2017-2018), semestralmente, foram coletadas amostras de águasconsumidas por moradores em diferentes pontos: poços 1 e 2, ambos sem tratamento e com o auxílio de amostradores descartáveis do tipo bailer e; torneiras, denominados S1 e S2, água tratada pela Companhia de Saneamento Básico do Estado de São Paulo (SABESP) e destinadas ao abastecimento público. Esses últimos como grupo controle, pois não foram identificados poços de monitoramento ou nascentes próximas sem contaminação. As amostras em frascos apropriados foram preservadas em caixas térmicas (± 4°C) e encaminhadas para análise química e microbiológica, seguindo os protocolos de coletas da CETESB e USEPA e os métodos 4500-NO3-B e 9215c da APHA. As análises físico-químicas, tais como pH, OD, temperatura, cloro livre, condutividade elétrica e profundidade foram realizadas em campo com equipamentos, tais como multiparâmetro da marca Hanna Hi 9828 e outros. Resultados ­ Verificou-se que as águas subterrâneas são de natureza rasas (poços com profundidade < 20 m) e suas águas ligeiramente ácida (pH=5,0). Em ambos os poços houve a presença de bactérias E. coli e elevada concentração do íon nitrato (>18 mg/L) no período seco e chuvoso, estando em não conformidade ao VMP dado pela Portaria 2.914. As amostras S1 e S2 apresentaram ausência de E.coli e valores abaixo de 0,5 mg/L de N-NO-3. informação dos parâmetros de qualidade nos rótulos. O levantamento de alguns rótulos, mostrou que em cinco marcas de água envasadas, três delas estão não conforme a VMP ora citada (NO-3-N > 10 mg/L). Conclusão ­ O presente estudo demonstrou que para fins de potabilidade a água dos poços está imprópria para o consumo humano

Objective ­ To verify nitrate concentration, the presence or absence of Escherichia coli bacterium in groundwater samples (wells) intended for human consumption, and to compare the results to Maximum Permitted Values (MPV) by Portaria 2.914 of the Ministry of Health. Methods ­ During one year (2017-2018), samples of water consumed by residents at different points were taken every semester: wells 1 and 2, both without treatment and with the aid of disposable samplers of the bailer type; taps, called S1 and S2, water treated by the Basic Sanitation Company of the State of São Paulo (SABESP) and intended for public supply. The latter as a control group because no monitoring wells or nearby springs were identified without contamination. The samples in appropriate flasks were preserved in thermal boxes (± 4°C) and sent for chemical and microbiological analysis, following CETESB and USEPA collection protocols and APHA methods 4500-NO3-B and 9215c. Physical-chemical analyzes, such as pH, OD, temperature, free chlorine, electrical conductivity and depth were performed in the field with equipment such as multi-parameter, Hanna brand and others. Results ­ Groundwaters were found to be shallow (wells with depth <20 m) and their waters slightly acidic (pH = 5.0). In both wells, the presence of E. coli bacteria and high concentration of nitrate ion (> 18 mg / L) in the dry and rainy season were observed, being in non-compliance with the MPV given by Portaria 2.914. Samples S1 and S2 showed absence of E.coli and values below 0.5 mg / L of N-NO-3. Information on the quality parameters on the labels. The survey of some labels showed that in five bottled watermarks, three of them are contaminated by nitrate according to the MPV (NO-3-N> 10 mg / L). Conclusion ­ The present study demonstrates that drinking water from wells is unfit for human consumption.

Kinetic characterization and modeling of a microalgae consortium isolated from landfill leachate under a high CO2 concentration in a bubble column photobioreactor

BACKGROUND: The determination of kinetic parameters and the development of mathematical models are of great interest to predict the growth of microalgae, the consumption of substrate and the design of photobioreactors focused on CO2 capture. However, most of the models in the literature have been developed for CO2 concentrations below 10%. RESULTS: A nonaxenic microalgal consortium was isolated from landfill leachate in order to study its kinetic behavior using a dynamic model. The model considered the CO2 mass transfer from the gas phase to the liquid phase and the effect of light intensity, assimilated nitrogen concentration, ammonium concentration and nitrate concentration. The proposed mathematical model was adjusted with 13 kinetic parameters and validated with a good fit obtained between experimental and simulated data. CONCLUSIONS: Good results were obtained, demonstrating the robustness of the proposed model. The assumption in the model of DIC inhibition in the ammonium and nitrate uptakes was correct, so this aspect should be considered when evaluating the kinetics with microalgae with high inlet CO2 concentrations.

High efficient assimilation of NO₃⁻-N with coproduction of microalgal proteins by Chlorella pyrenoidosa / 生物工程学报

The aim of this study was to establish a novel technology using microalgae for NO₃⁻ removal from high concentration wastewater and conversion to algal proteins. The effects of cultivation modes and illumination modes on the biomass yield, NO₃⁻ assimilation rate and algal protein yield were first investigated in shaking flasks for mixotrophic cultivation of Chlorella pyrenoidosa, and subsequently the scale-up verification in 5-L photo fermenter was successfully conducted. Fed-batch cultivation without medium recycling was the best cultivation mode in shaking flask system, in which the highest biomass yield (35.95 g/L), the average NO₃⁻ assimilation rate (2.06 g/(L·d)) and algal protein content (up to 42.44% of dry weight) were achieved. By using a staged increase of light intensity as illumination modes, the specific growth rate of cells could be significantly promoted to the highest (0.65 d⁻¹). After a 128-hour continuous cultivation in a 5-L photo fermenter, the highest biomass yield and the average NO₃⁻ assimilation rate were reached to 66.22 g/L and 4.38 g/(L·d) respectively, with the highest algal protein content at 47.13% of dry weight. Our study could provide a photo fermentation technology of microalgae for highly efficient treatment of waste industrial nitric acid and/or high concentration nitrate wastewater. This microalgae-based bioconversion process could coproduce protein-rich microalgal biomass, which facilitates the resource utilization of these type wastewater by trash-to-treasure conversion.