RESUMO
Biofilters are the important source and sink of antibiotic resistance genes (ARGs) and antibiotic resistance bacteria (ARB) in the drinking water. Current studies generally ascribed the prevalence of BAR in biofilter from the perspective of gene behavior, i.e. horizontal gene transfer (HGT), little attentions have been paid on the ARGs carrier- ARB. In this study, we proposed the hypothesis that ARB participating in pollutant metabolism processes and becoming dominant is an important way for the enrichment of ARGs. To verify this, the antibiotic resistome and bacterial functional metabolic pathways of a sand filter was profiled using heterotrophic bacterial plate counting method (HPC), high-throughput qPCR, Illumina Hiseq sequencing and PICRUSt2 functional prediction. The results illustrated a significant leakage of ARB in the effluent of the sand filter with an average absolute abundance of approximately 102-103 CFU/mL. Further contribution analysis revealed that the dominant genera, such as Acinetobacter spp., Aeromonas spp., Elizabethkingia spp., and Bacillus spp., were primary ARGs hosts, conferring resistance to multiple antibiotics including sulfamethoxazole, tetracycline and ß-lactams. Notably, these ARGs hosts were involved in nitrogen metabolism, including extracellular nitrate/nitrite transport and nitrite reduction, which are crucial in nitrification and denitrification in biofilters. For example, Acinetobacter spp., the dominant bacteria in the filter (relative abundance 69.97 %), contributed the majority of ARGs and 53.79 % of nitrite reduction function. That is, ARB can predominate by participating in the nitrogen metabolism pathways, facilitating the enrichment of ARGs. These findings provide insights into the stable presence of ARGs in biofilters from a functional metabolism perspective, offering a significant supplementary to the mechanisms of the emergence, maintenance, and transmission of BARin drinking water.
Assuntos
Antibacterianos , Água Potável , Antibacterianos/farmacologia , Antibacterianos/análise , Genes Bacterianos , Antagonistas de Receptores de Angiotensina/análise , Nitritos/análise , Resistência Microbiana a Medicamentos/genética , Inibidores da Enzima Conversora de Angiotensina/análise , Nitrogênio/análiseRESUMO
Background: This single-center retrospective study compared the efficacy of breast-conserving therapy along with axillary lymph node dissection (ALND) with mastectomy and ALND with regard to survival of Chinese patients with occult breast cancer. Materials & methods: Univariate Kaplan-Meier analysis and multivariate Cox proportional hazards model were used to compare treatments and prognosis. Results: A total of 111 patients with a median follow-up of 72.9 months were included. 39 patients with mastectomy + ALND had better disease-free survival than 72 patients with breast-conserving therapy + ALND (HR = 0.31; p = 0.012). Patients with radiotherapy demonstrated inferior survival for both overall survival (HR = 2.67; p = 0.071) and disease-free survival (HR = 5.35; p = 0.002). Surgical strategies and radiotherapy remained significantly predictive of better disease-free survival in multivariate analyses. Conclusion: Mastectomy and ALND demonstrate superior disease-free prognosis compared with breast-conserving therapy and ALND in occult breast cancer.
Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/cirurgia , Mastectomia , Estudos Retrospectivos , Prognóstico , Mastectomia Segmentar , Excisão de Linfonodo/efeitos adversos , Biópsia de Linfonodo SentinelaRESUMO
Milk fat globules (MFGs) surround the triacylglycerol core that composes milk fat. The aim of this study is to induce milk fat depression via dietary conjugated linoleic acid (CLA) supplementation to study MFG size parameters, number and glycerophospholipid composition. Eighteen Holstein dairy cows (136 ± 28 days in milk, 571 ± 37.9 kg body weight, 27.6 ± 2.1 kg milk/day) were selected and randomly assigned to a control or CLA group for a 14-day period. Cows were fed a basal diet (control, n = 8) or the control plus 400 g/day CLA (C18:2 cis-9, trans-11 38.1% and C18:2 trans-10, cis-12 36.8%) (n = 10) for 7 days after which the CLA group was switched to the basal diet for another 7 days along with the control group. Cow performance, milk composition, MFG size and numbers were measured daily. On the seventh day after the start of the experiment, milk samples were identified and the quantification of glycerophospholipid compounds, and RNA were isolated from milk fat samples for a real-time polymerase chain reaction. Compared with control, at Day 7 from the start of feeding, supplemental CLA did not affect milk production (28.09 vs. 28.50 kg/day), dry matter intake (14.9 vs. 15.4 kg/day), or milk protein (3.55/100 vs. 3.70 g/100 ml) and lactose contents (5.11/100 vs. 5.17 g/100 ml). However, although the specific surface area of MFG (2138 vs. 1815 m²/kg) was greater, CLA reduced milk fat content (1.95/100 vs 3.64 g/100 ml on Day 7) and particle size parameters of MFG. The number of MFG gradually decreased until Day 7 of feeding, and then increased by Day 14 (2.96 × 109 on Day 1, 1.63 × 109 on Day 7 and 2.28 × 109 on Day 14) in the CLA group. Compared with control, glycerophospholipid analysis revealed that concentrations of phosphatidylcholine (PC) (e.g., PC [16:0/18:1] 20322 vs. 29793 nmol/L), lysophosphatidylethanolamine (LPE) (e.g., LPE [18:1] 956 vs. 4610 nmol/L) and phosphatidylethanolamine (PE) (e.g., PE [16:0/18:1] 7000 vs. 9769 nmol/L) in milk lipids decreased during CLA feeding. In contrast, concentrations of phosphatidylinositol (PI) (e.g., PI [18:0/18:1] 4052 vs. 1799 nmol/L) and phosphatidylserine (PS) (e.g., PS [18:1/18:2] 9500 vs. 6843 nmol/L) increased. The messenger RNA abundance of fatty acid synthase, diacylglycerol O-acyltransferase 1, glycerol-3-phosphate acyltransferase 4 and phosphate cytidylyltransferase 1, choline, alpha (PCYT1A) were downregulated in the CLA group, confirming published data demonstrating a negative effect of CLA on lipogenesis in the mammary gland. Overall, these results provided evidence for the important role of lipogenic gene expression in the regulation of MFG size, number and glycerophospholipid composition.
Assuntos
Ácidos Linoleicos Conjugados , Feminino , Animais , Bovinos , Ácidos Linoleicos Conjugados/farmacologia , Lactação/fisiologia , Ácidos Graxos/metabolismo , Fosfolipídeos , Dieta/veterinária , Glicerofosfolipídeos/farmacologia , Suplementos Nutricionais/análiseRESUMO
Electrochemical reduction reaction of carbon monoxide (CORR) offers a promising way to manufacture acetic acid directly from gaseous CO and water at mild condition. Herein, we discovered that the graphitic carbon nitride (g-C3 N4 ) supported Cu nanoparticles (Cu-CN) with the appropriate size showed a high acetate faradaic efficiency of 62.8 % with a partial current density of 188â mA cm-2 in CORR. In situ experimental and density functional theory calculation studies revealed that the Cu/C3 N4 interface and metallic Cu surface synergistically promoted CORR into acetic acid. The generation of pivotal intermediate -*CHO is advantage around the Cu/C3 N4 interface and migrated *CHO facilitates acetic acid generation on metallic Cu surface with promoted *CHO coverage. Moreover, continuous production of acetic acid aqueous solution was achieved in a porous solid electrolyte reactor, indicating the great potential of Cu-CN catalyst in the industrial application.
RESUMO
With the ever-increasing severity of the ongoing water crisis, it is of great significance to develop efficient, eco-friendly water treatment technologies. As an emerging oxidant in the advanced oxidation processes (AOPs), periodate (PI) has received worldwide attention owing to the advantages of superior stability, susceptible activation capability, and high efficiency for decontamination. This is the first review that conducts a comprehensive analysis of the mechanism, pollutant transformation pathway, toxicity evolution, barriers, and future directions of PI-based AOPs based on the scientific information and experimental data reported in recent years. The pollutant elimination in PI-based AOPs was mainly attributed to the in situ generate reactive oxygen species (e.g., â¢OH, O(3P), 1O2, and O2â¢-), reactive iodine species (e.g., IO3⢠and IO4â¢), and high-valent metal-oxo species with exceptionally high reactivity. These reactive species were derived from the PI activated by the external energy, metal activators, alkaline, freezing, hydroxylamine, H2O2, etc. It is noteworthy that direct electron transport could also dominate the decontamination in carbon-based catalyst/PI systems. Furthermore, PI was transformed to iodate (IO3-) stoichiometrically via an oxygen-atom transfer process in most PI-based AOPs systems. However, the production of I2, I-, and HOI was sometimes inevitable. Furthermore, the transformation pathway of typical micropollutants was clarified, and the in silico QSAR-based prediction results indicated that most transformation products retained biodegradation recalcitrance and multi-endpoint toxicity. The barriers faced by the PI-based AOPs were also clarified with potential solutions. Finally, future perspectives and research directions are highlighted based on the current state of PI-based AOPs. This review enhances our in-depth understanding of PI-based AOPs for pollutant elimination and identifies future research needs to focus on the reduction of toxic byproducts.
Assuntos
Poluentes Ambientais , Iodo , Poluentes Químicos da Água , Purificação da Água , Carbono , Descontaminação , Hidroxilaminas , Iodatos , Oxidantes , Oxirredução , Oxigênio , Ácido Periódico , Espécies Reativas de Oxigênio , Purificação da Água/métodosRESUMO
Aplastic anemia (AA) and myelodysplastic syndrome (MDS) are clonal diseases with hemopoietic stem cell (HSC) abnormalities,which are sometimes difficult to be distinguished from each other.The development of molecular detection techniques has facilitated our understanding of the molecular pathogenesis of the two diseases.This article reviewed the somatic mutation (SM) and cytogenetic changes of AA,and analyzed their molecular relationship with MDS and their roles in disease transformation.The most common somatic change in AA is the loss of PIGA and HLA alleles,which,along with trisomy 8 and del(13q),is related to the immune pathogenesis of AA.Among the 5 most common mutations in AA,PIGA and BCOR/BCORL1 mutations are related to a good prognosis,while DNMT3A and ASXL1 mutations are likely associated with clonal evolution and a poor prognosis.The risk factors for secondary MDS after AA include SM and cytogenetic changes such as del(7q) associated with poor prognosis,prolonged disease duration after diagnosis,onset age of AA,and leukocyte telomere attrition.Although role of SM in disease progression remains unclear because of its dynamic change and unknown significance,prognostic assessment based on the monitoring of SM and clinical features may guide the treatment.
Assuntos
Anemia Aplástica , Síndromes Mielodisplásicas , Anemia Aplástica/genética , Humanos , Mutação , Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Prognóstico , Fatores de RiscoRESUMO
Nanoconfinement provides a promising solution to promote electrocatalytic C-C coupling, by dramatically altering the diffusion kinetics to ensure a high local concentration of C1 intermediates for carbon dimerization. Herein, under the guidance of finite-element method simulations results, a series of Cu2 O hollow multi-shell structures (HoMSs) with tunable shell numbers were synthesized via Ostwald ripening. When applied in CO2 electroreduction (CO2 RR), the in situ formed Cu HoMSs showed a positive correlation between shell numbers and selectivity for C2+ products, reaching a maximum C2+ Faradaic efficiency of 77.0±0.3 % at a conversion rate of 513.7±0.7â mA cm-2 in a neutral electrolyte. Mechanistic studies clarified the confinement effect of HoMSs that superposition of Cu shells leads to a higher coverage of localized CO adsorbate inside the cavity for enhanced dimerization. This work provides valuable insights for the delicate design of efficient C-C coupling catalysts.
RESUMO
This study was carried out to explore the role of the long noncoding RNA (lncRNA) SAMMSON in triple-negative breast cancer (TNBC). The research patients in this study included 68 TNBC patients. Cell Counting Kitcck-8 were utilized to determine cell proliferation abilities, respectively. Proteins and mRNAs were estimated by western blot and Methylation-specific polymerase chain reaction, respectively. We found that SAMMSON was upregulated, while p53 was downregulated in cancer (TNBC) tissues than in non-cancer tissues of TNBC patients. SAMMSON expression levels in TNBC tissues increased with the increase of clinical stages of TNBC patients. SAMMSON and p53 were inversely correlated in TNBC tissues. In TNBC cells, SAMMSON overexpression decreased p53 expression, while p53 overexpression failed to affect SAMMSON expression. In addition, SAMMSON overexpression increased TNBC cell proliferation, while p53 overexpression decreased the proliferation rates of TNBC cells. In addition, p53 overexpression attenuated the effects of SAMMSON overexpression. Therefore, overexpression of SAMMSON could promote TNBC cell proliferation by interacting with p53.
Assuntos
MicroRNAs , RNA Longo não Codificante , Neoplasias de Mama Triplo Negativas , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , RNA Longo não Codificante/genética , Neoplasias de Mama Triplo Negativas/genética , Proteína Supressora de Tumor p53/genéticaRESUMO
BACKGROUND: Unilateral breast cancer (UBC) patients with germline pathogenic BRCA1/2 variants have a higher risk of developing contralateral breast cancer (CBC) and need contralateral risk-reducing local treatments, including contralateral risk-reducing mastectomy (CRRM) and prophylactic irradiation (CPI). The aim of our study was to systematically explore the efficacy of CRRM and CPI in reducing CBC risk and increasing survival. METHODS: A search was done, and eligible randomized trials and cohort studies should include and compare UBC patients with germline pathogenic BRCA1/2 variants who have and have not received contralateral risk-reducing local treatment. Random-effects meta-analysis was used in this study. Primary outcomes of the studies included overall survival (OS) and the incidence of contralateral breast cancer (CBC), and secondary outcomes included breast cancer-specific survival (BCSS). RESULTS: A total of five studies with 1769 UBC patients with germline pathogenic BRCA1/2 variants were enrolled in our meta-analysis. CRRM was correlated with a lower risk of CBC in UBC patients with germline pathogenic BRCA1/2 variants (summary RR = 0.07; 95%CI 0.03-0.13, I2 = 3%), a significantly increased OS (summary RR, 1.15; 95%CI 1.04-1.26, I2 = 26%) and a significantly increased BCSS (summary RR, 1.18; 95%CI 1.07-1.31, I2 = 64%) compared with surveillance. CPI also decreased the risk of CBC (RR 0.02; 95%CI 0.05-0.88) but did not significantly improve OS (RR 0.97; 95%CI 0.90-1.05) and BCSS (RR 0.97; 95%CI 0.90-1.05) compared with surveillance. CONCLUSIONS: CRRM reduces CBC risk and increases OS and BCSS in UBC patients with germline pathogenic BRCA1/2 variants, and could be offered as a risk-reducing local treatment. For those who oppose CRRM, CPI could be offered for CBC-risk reduction, while its survival benefit is still uncertain.
RESUMO
Acetyl-CoA synthetase 2 (ACSS2) is a conserved nucleocytosolic enzyme that converts acetate to acetyl-CoA. Adult mice lacking ACSS2 appear phenotypically normal but exhibit reduced tumor burdens in mouse models of liver cancer. The normal physiological functions of this alternate pathway of acetyl-CoA synthesis remain unclear, however. Here, we reveal that mice lacking ACSS2 exhibit a significant reduction in body weight and hepatic steatosis in a diet-induced obesity model. ACSS2 deficiency reduces dietary lipid absorption by the intestine and also perturbs repartitioning and utilization of triglycerides from adipose tissue to the liver due to lowered expression of lipid transporters and fatty acid oxidation genes. In this manner, ACSS2 promotes the systemic storage or metabolism of fat according to the fed or fasted state through the selective regulation of genes involved in lipid metabolism. Thus, targeting ACSS2 may offer a therapeutic benefit for the treatment of fatty liver disease.
Assuntos
Acetato-CoA Ligase/metabolismo , Tecido Adiposo/metabolismo , Fígado Gorduroso/metabolismo , Regulação da Expressão Gênica , Metabolismo dos Lipídeos , Fígado/metabolismo , Acetato-CoA Ligase/genética , Acetilcoenzima A/genética , Acetilcoenzima A/metabolismo , Tecido Adiposo/patologia , Animais , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Fígado/patologia , Camundongos , Camundongos KnockoutRESUMO
Objective To compare the efficacy and safety of cyclosporin A(CsA)and CsA combined with recombined human erythropoietin(rhEPO)in the treatment of patients with chronic aplastic anemia(CAA).Methods Data of 79 patients with CAA treated at Department of Hematology,PUMC Hospital between January 2016 and June 2018 were collected for retrospective analysis.Forty-five patients were treated with CsA+rhEPO,and the other 34 patients with CsA alone.All the enrolled patients were treated for at least 1.5-2.0 years and followed for at least 1.0 year.The efficacy,side effects,long-term outcomes were compared between the two groups,and factors that may influence the efficacy were analyzed.Results The patients treated with CsA+rhEPO included 14 males and 31 females,with a median age of 43(19,73)years old.The median treatment duration of CsA and rhEPO was 26(12,38)and 4(3,6)months,respectively,and the median followed-up time was 24(12,42)months.The patients treated with CsA alone included 16 males and 18 females,with a median age of 36(16,85)years old.The median CsA treatment duration was 24(12,40)months and the median follow-up time was 25(12,40)months.There was no statistical difference in baseline characteristics between the two groups(all P>0.05).After 6 months of treatment,CsA+rhEPO group had higher overall response(OR)rate(55.6% vs. 31.3%;χ 2=4.456,P=0.040)and partial response(PR)rate(53.3% vs. 25.0%;χ2=6.181,P=0.019)than CsA group,and the complete response(CR)rate showed no statistical difference between the two groups(2.2% vs. 6.3%;χ2=0.810,P=0.567).The CR,PR,and OR rates showed no statistical difference between the two groups after 3 and 12 months of treatment and at the end of follow-up(all P>0.05).Similarly,the hemoglobin level at the sixth month of treatment with CsA+rhEPO was higher than that with CsA alone [(102.6±24.0)g/L vs.(90.3±29.1)g/L;t=2.017,P=0.047].However,it showed no significant difference between the two groups at other time points(all P>0.05).The side effects,including an increase in serum creatinine,slight increase in bilirubin,increase in aminotransferase,mild to moderate gingival hyperplasia,gastrointestinal reaction,and muscular fibrillation,had no significant differences between the two groups(all P>0.05),except that 11.1%(5/45)patients in the CsA+rhEPO group reported soreness at the injection site.The two groups showed similar rates of clonal revolution during the follow-up period and no death.No clinical factor was found for prediction of the efficacy of CsA+rhEPO. Conclusion CsA+rhEPO has higher OR rate and hemoglobin level than CsA alone at the sixth month of treatment,and it has similar side effects compared with CsA alone.
Assuntos
Anemia Aplástica , Eritropoetina , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia Aplástica/tratamento farmacológico , Ciclosporina/uso terapêutico , Eritropoetina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes , Indução de Remissão , Estudos Retrospectivos , Adulto JovemRESUMO
Microbial contamination during fuel storage can cause fuel system fouling and corrosion. Characterizing microbial contamination is critical for preventing and solving these problems. In this study, culture-based combing with the culture-independent methods, were used to profile the microbial contamination in aviation fuel. High-throughput sequencing (HTS) modified by propidium monoazide (PMA) revealed a higher diversity of contaminating microorganisms in samples than the culture method. Proteobacteria (47%), Actinobacteria (21%) and Ascomycota (>99%, fungi) were the most abundant phyla, and the neglected archaea was also detected. Additionally, qPCR-based methods revealed all samples contained a heavy level of microbial contamination, which was more accurate than its culturable counterparts, and fungal contamination was still a problem in aviation fuel. The application of a PCR-based method gives deeper insight into microbial contamination in aviation fuel than the conventional culture method, thus using it for regular detection and accurate description of fuel contamination is strongly recommended in the case of explosive microbial growth.
Assuntos
Actinobacteria/isolamento & purificação , Aeroportos , Ascomicetos/isolamento & purificação , Incrustação Biológica/prevenção & controle , Gasolina/microbiologia , Proteobactérias/isolamento & purificação , Gasolina/normas , Sequenciamento de Nucleotídeos em Larga Escala , Microbiota/genética , RNA Ribossômico 16S , Reação em Cadeia da Polimerase em Tempo RealRESUMO
In milk, fat exists in the form of milk fat globules (MFGs). The average size (average fat globules of different particle sizes) is the most common parameter when describing MFG size. There are different views on whether there is a correlation between MFG size and milk fat content. Is the MFG size correlated with milk fat content in ruminants? To address this question, we conducted two experiments. In experiment â , dairy cows (n = 40) and dairy goats (n = 30) were each divided into a normal group and a low-fat group according to the milk fat content. In experiment â ¡, dairy cows (n = 16) and dairy goats (n = 12) were each divided into a normal group and a conjugated linoleic acid (CLA)-induced low-fat group. The normal groups were fed a basal diet, and the CLA-induced low-fat groups were fed the basal diet + 300 g/d CLA (cows) or the basal diet + 90 g/d CLA (goats). In both experiments, we determined the correlation between MFG size and milk composition and MFG distribution. The results showed that in the normal and low-fat groups of cows and goats, MFG size was not correlated with milk fat, protein, or lactose content or fat-to-protein ratio. Additionally, there was no difference in the distribution of large, medium, and small MFGs (P > 0.05). However, in the CLA-induced low-fat groups, we found a correlation between MFG size and milk fat content and fat-to-protein ratio (R2 > 0.3). Moreover, there was a significant change in the size distribution of MFGs. Therefore, in natural milk, MFG size was not correlated with milk fat content. Following CLA supplementation, MFG size was correlated with milk fat content. Our findings revealed that CLA and not milk fat affects MFG distribution and size.
Assuntos
Lactação , Ácidos Linoleicos Conjugados , Feminino , Bovinos , Animais , Ácidos Graxos/metabolismo , Leite/metabolismo , Dieta/veterinária , Cabras/metabolismo , Ácidos Linoleicos Conjugados/metabolismo , Suplementos NutricionaisRESUMO
The presence of "viable but nonculturable" (VBNC) state and bacterial antibiotic resistance (BAR) both pose significant threats to the safety of drinking water. However, limited data was available that explicitly addressed the contribution of bacterial VBNC state in the maintenance and propagation of BAR. Here, the VBNC state induction and resuscitation of two antibiotic-resistant Escherichia coli K12 strains, one carrying multidrug-resistant plasmid (RP4 E. coli) and the other with chromosomal mutation (RIF E. coli) were characterized by subjecting them to different doses of UV/chlorine. The results illustrated that the induction, resuscitation, and associated mechanisms of VBNC ARB exhibit variations based on resistance determinants. RP4 E. coli exhibited a higher susceptibility to enter VBNC state compared to the RIF E. coli., and most VBNC state and resuscitated RP4 E. coli retained original antibiotic resistance. While, reverse mutation in the rpoB gene was observed in VBNC state and recovered RIF E. coli strains induced by high doses of UV/chlorine treatment, leading to the loss of rifampicin resistance. According to RT-qPCR results, ARGs conferring efflux pumps appeared to play a more significant role in the VBNC state formation of RP4 E. coli and the down-regulation of rpoS gene enhanced the speed at which this plasmid-carrying ARB entered into the dormant state. As to RIF E. coli, the induction of VBNC state was supposed to be regulated by the combination of general stress response, SOS response, stringent response, and TA system. Above all, this study highlights that ARB could become VBNC state during UV/chlorine treatments and retain, in some cases, their ability to spread ARGs. Importantly, compared with chromosomal mutation-mediated ARB, both VBNC and resuscitated state ARB that carries multidrug-resistant plasmids poses more serious health risks. Our study provides insights into the relationship between the VBNC state and the propagation of BAR in drinking water systems.
Assuntos
Cloro , Escherichia coli , Raios Ultravioleta , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Cloro/farmacologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Plasmídeos , Proteínas de Escherichia coli/genética , Mutação , Viabilidade MicrobianaRESUMO
Most polycyclic aromatic hydrocarbons (PAHs), which are persistent organic pollutants, have strong carcinogenicity, teratogenicity, and mutagenicity, and pose serious threats to the ecological environment and human health. Owing to the complexity of the matrix and low PAH content of environmental samples, separating and enriching PAHs in environmental samples is necessary prior to their detection. Solid-phase microextraction (SPME) technology is commonly used to detect PAHs owing to its advantages of simple operation, online connection with other instruments, low solvent usage, and integrability of sampling separation, enrichment, and desorption. The extraction coating is the core of this technology, and the type and thickness of the coating are important factors affecting the sensitivity and accuracy of the analysis. Common commercial extraction coatings include polydimethylsiloxane and quartz fiber; however, these materials have a number of disadvantages, such as poor thermal stability and high cost. Several methods, including electrochemical, sol-gel, molecular imprinting, and other coating methods, have been developed to prepare SPME coatings. Electrochemical methods have attracted considerable attention because of their simplicity, short duration, and high coating stability. In the development of an electrochemical method, the selection of the conductive polymer is of particular importance. Polypyrroles (Ppy) are easily synthesized and have numerous advantages, such as good conductivity and stable chemical properties. Thus, their use as a substrate material for SPME coatings is beneficial for improving the overall stability of the coating. Copolymerization with other polymers can enhance the adsorption performance of such coatings via synergistic effects. When doped with inorganic materials with high thermal stability, the composite coating can exhibit high temperature resistance. In this study, a porous boron nitride-doped Ppy-2,3,3-trimethylindole (Ppy/P2,3,3-TMe@In/BN) composite was prepared as a new SPME copolymer coating to detect three PAHs: naphthalene (NAP), acenaphthene (ANY), and fluorene (FLU). Scanning electron microscopy, thermal stability analysis, Fourier transform infrared spectroscopy, and other techniques were used to characterize the Ppy/P2,3,3-TMe@In/BN composite coating. The results showed that the coating featured a large number of porous and wrinkled dendritic structures, which increased the specific surface area of the composite coating and enabled the extensive enrichment of the three PAHs. When the sample inlet temperature of the chromatograph is 320 â, the chromatographic baseline of the coating is basically stable. Compared with commercial coatings, the prepared coating had better thermal stability. The coating formed stable intermolecular forces with the three PAHs owing to its numerous carbon-carbon double bonds (C=C), hydrogen bonds, and other structures, thereby achieving excellent enrichment of the target analytes. Compared with Ppy, Ppy/PIn, Ppy/P2,3,3-TMe@In, Ppy/BN, and polydimethylsiloxane (PDMS) coatings, the prepared Ppy/P2,3,3-TMe@In/BN composite coating exhibited better extraction effects for the three PAHs. The Ppy/P2,3,3-TMe@In/BN composite coating was polymerized on the surface of a stainless-steel wire by cyclic voltammetry and combined with gas chromatography-hydrogen flame ionization detection (GC-FID) to optimize the conditions influencing the extraction and separation of the three PAHs, thereby establishing a highly sensitive analytical method for detecting NAP, ANY, and FLU. This method had low limits of detection (LODs) of 10.6-14.5 ng/L (S/N=3) and high stability. The SPME-GC-FID method was used to detect the three PAHs in two environmental water samples, and a small amount of ANY (1.39 µg/L) was detected in one water sample. Satisfactory recoveries (82.5%-113.9%) were obtained when both water samples were spiked with the three PAHs at three levels. The experimental results indicate that the established analytical method can detect the three PAHs in environmental water samples.
RESUMO
Tetracycline's (TC) incomplete self-photolysis by light irradiation generally produces toxic intermediate products, which posing serious harm to the aqueous environment. In order to diminish the environmental risks of TC self-photolysis, an iron(III)-alginate (Fe-SA) hydrogel assisted photocatalytic method was developed and the underlying mechanisms was also analyzed in this work. Under simulated sunlight, the photo-degradation efficiency of TC was 61.1% at pH 7.0 within 2 h. Importantly, four of the seven intermediate products that identified during the self-photolysis of TC were found toxic based on QSAR analysis. In contrast, the removal efficiency of TC could be improved to 87.4% by adding Fe-SA under the same conditions. Moreover, only two relatively weakly toxic intermediate products were detected after exposing to the Fe-SA photocatalytic system, indicating a significant reduction of the potential ecological risks caused by TC self-photolysis. Furthermore, the determination of reactive oxidation species (ROS) demonstrated that the addition of Fe-SA primarily facilitated the degradation of TC and the related toxic intermediate products through assisting the free radical (âOH and âO2-) photocatalytic degradation pathway. Additionally, the photocatalytic application under actual sunlight conditions and the reusability experiments of Fe-SA further confirmed its effectiveness and low cost in removing TC. This study revealed the photodegradation mechanisms of TC from the perspective of the self-photolysis process, and also offering new insights into the removal of TC pollution in the environment.
Assuntos
Compostos Heterocíclicos , Águas Residuárias , Fotólise , Alginatos , Ferro , Tetraciclina , Antibacterianos , AquiculturaRESUMO
Background: Clinically, unilateral peripheral vestibular dysfunction (UPVD) with dizziness or vertigo as the chief complaint is quite common. This study aimed to investigate the correlations between 3-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI) findings and cochleovestibular function test results in patients with UPVD and to explore the possible etiologies of UPVD. Methods: This retrospective study enrolled 76 patients with UPVD. Endolymphatic hydrops (EH) and perilymphatic enhancement (PE) in the vestibule and cochlea on 3D-FLAIR images, their correlations with the parameters of the cochleovestibular function test and vascular risk factors, and the immunological findings of patients with EH and PE were assessed. Results: Of the included patients, 48.7% showed positive MRI findings (the presence of EH and PE on 1 side). The pure-tone average (PTA) was higher in patients with cochlear PE than in those with vestibular (P=0.014) and cochlear EH (P=0.02). The canal paresis (CP) value was also higher in patients with vestibular PE than in those with vestibular (P=0.002) and cochlear EH (P=0.003). Video head impulse test (vHIT) gains were lower in patients with vestibular and cochlear PE than in those with vestibular and cochlear EH (P<0.001). A positive correlation was observed between the degree of vestibular and cochlear EH and PTA (both P values <0.001). PTA and CP with a cutoff value of 32 dB and 46.5%, respectively, yielded high sensitivity and specificity in determining positive MRI findings (P<0.001 and P=0.029, respectively). The prevalence of vascular risk factors was significantly higher in patients with PE than in those with EH (P=0.033). Conclusions: (I) Nearly half of the patients UPVD exhibited abnormal MRI findings. Cutoff values for PTA and CP of 32 dB and 46.5%, respectively, indicated that patients were more likely to have abnormal imaging findings. (II) The severity of EH was positively correlated with hearing impairment. (III) Patients with PE showed severe hearing impairment and vestibular dysfunction, which was presumed to be associated with vascular damage.
RESUMO
OBJECTIVES: The occurrence of direction-reversing nystagmus during positional testing in patients with benign paroxysmal positional vertigo (BPPV) is not uncommon. Further in-depth analysis of the characteristics and possible mechanisms of direction-reversing nystagmus will help us to diagnose and treat BPPV more precisely. The study aimed to analyze the incidence and characteristics of direction-reversing nystagmus during positional testing in BPPV patients, evaluate the outcomes of canalith repositioning procedure for these patients, and further explore the possible mechanism of reversal nystagmus in BPPV patients. STUDY DESIGN: Retrospective study. SETTING: Single-center study. PATIENTS: A total of 575 patients with BPPV who visited the Vertigo Clinic of our hospital between April 2017 and June 2021 were enrolled. MAIN OUTCOME MEASURES: Dix-Hallpike and supine roll tests were performed. The nystagmus was recorded using videonystagmography. The characteristics of direction-reversing nystagmus and the possible underlying mechanism were analyzed. RESULTS: Patients with BPPV who showed reversal nystagmus accounted for 9.39% (54 of 575) of all BPPV patients visiting our hospital during the same period, of which 5.57% (32 of 575) had horizontal semicircular canal BPPV (HC-BPPV), and 3.83% (22 of 575) had posterior semicircular canal BPPV (PC-BPPV). The maximum slow-phase velocities (mSPVs) of the first-phase nystagmus were greater in HC-BPPV and PC-BPPV patients with reversal nystagmus than those without ( p = 0.04 and p = 0.01, respectively). In all HC-BPPV and PC-BPPV patients with reversal nystagmus, the mSPV of the first-phase nystagmus was greater than that of the second-phase nystagmus ( p < 0.01). The duration of the second-phase nystagmus was longer than 60 seconds in 93.75% (30 of 32) of the HC-BPPV patients and 77.27% (17 of 22) of the PC-BPPV patients ( p = 0.107, Fisher exact test). HC-BPPV and PC-BPPV patients with reversal nystagmus both required more than one canalith repositioning procedure compared with those without (HC-BPPV: 75 versus 28.13%, p < 0.001; PC-BPPV: 59.09 versus 13.64%, p = 0.002). CONCLUSIONS: The cause of second-phase nystagmus in BPPV patients with direction-reversing nystagmus may be related to the involvement of central adaptation mechanisms secondary to the overpowering mSPV of the first-phase nystagmus.
Assuntos
Vertigem Posicional Paroxística Benigna , Nistagmo Patológico , Humanos , Vertigem Posicional Paroxística Benigna/terapia , Estudos Retrospectivos , Nistagmo Patológico/diagnóstico , Nistagmo Patológico/etiologia , Testes de Função Vestibular/efeitos adversos , Canais SemicircularesRESUMO
Introduction: Non-tuberculous mycobacteria (NTM) is a major category of environmental bacteria in nature that can be divided into rapidly growing mycobacteria (RGM) and slowly growing mycobacteria (SGM) based on their distinct growth rates. To explore differential molecular mechanisms between RGM and SGM is crucial to understand their survival state, environmental/host adaptation and pathogenicity. Comparative genomic analysis provides a powerful tool for deeply investigating differential molecular mechanisms between them. However, large-scale comparative genomic analysis between RGM and SGM is still uncovered. Methods: In this study, we screened 335 high-quality, non-redundant NTM genome sequences covering 187 species from 3,478 online NTM genomes, and then performed a comprehensive comparative genomic analysis to identify differential genomic characteristics and featured genes/protein domains between RGM and SGM. Results: Our findings reveal that RGM has a larger genome size, more genes, lower GC content, and more featured genes/protein domains in metabolism of some main substances (e.g. carbohydrates, amino acids, nucleotides, ions, and coenzymes), energy metabolism, signal transduction, replication, transcription, and translation processes, which are essential for its rapid growth requirements. On the other hand, SGM has a smaller genome size, fewer genes, higher GC content, and more featured genes/protein domains in lipid and secondary metabolite metabolisms and cellular defense mechanisms, which help enhance its genome stability and environmental adaptability. Additionally, orthogroup analysis revealed the important roles of bacterial division and bacteriophage associated genes in RGM and secretion system related genes for better environmental adaptation in SGM. Notably, PCoA analysis of the top 20 genes/protein domains showed precision classification between RGM and SGM, indicating the credibility of our screening/classification strategies. Discussion: Overall, our findings shed light on differential underlying molecular mechanisms in survival state, adaptation and pathogenicity between RGM and SGM, show the potential for our comparative genomic pipeline to investigate differential genes/protein domains at whole genomic level across different bacterial species on a large scale, and provide an important reference and improved understanding of NTM.
RESUMO
BACKGROUND: Evaluation of vestibular graviceptive pathway (VGP) in patients with unilateral peripheral vestibular dysfunction (UPVD) has received increasing attention from researchers. The study aimed to investigate the value of VGP evaluation in the diagnosis of UPVD. METHODS: Ninety-five UPVD patients were divided into attack and remission phase groups. VGP evaluation-related indicators, including subjective visual vertical (SVV), subjective visual horizontal (SVH), head tilt, ocular torsion (OT), and skew deviation (SD), were measured, and their correlations with cochleovestibular function test results were analyzed. The possible etiologies of contralesional VGP (c-VGP) were analyzed. RESULTS: Positive rates of SVV, SVH, OT, and SD were significantly higher, and the degrees of SVV, SVH, and OT were significantly greater in the attack phase group than the remission phase group. The sides with abnormal VGP evaluation results were correlated with the sides with hearing loss, abnormal caloric, and video head impulse test (vHIT) results. A total of 14 patients showed c-VGP, and possible etiologies included contralateral benign paroxysmal positional vertigo (n = 4), bilateral hearing loss (n = 8), bilateral vHIT gain reduction (n = 1), autoimmune diseases (n = 6), vascular risk factors (n = 6), lacunar infarction (n = 3), and endolymphatic hydrops (n = 3). CONCLUSIONS: Alterations in SVV, SVH, OT, and SD were noted in UPVD patients in different phases, which are presumed to be related to dynamic vestibular compensation; correlations between VGP evaluation results and cochleovestibular function test results indicate that VGP evaluation may be helpful for the diagnosis of the side affected in UPVD; the presence of c-VGP may be related to bilateral labyrinth lesions or endolymphatic hydrops on the affected side; and the involvement of autoimmune mechanisms also deserves attention.