Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 122
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Infection ; 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38884857

RESUMEN

OBJECTIVES: In this retrospective observational multicenter study, we aimed to assess efficacy and mortality between ceftazidime/avibactam (CAZ/AVI) or polymyxin B (PMB)-based regimens for the treatment of Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections, as well as identify potential risk factors. METHODS: A total of 276 CRKP-infected patients were enrolled in our study. Binary logistic and Cox regression analysis with a propensity score-matched (PSM) model were performed to identify risk factors for efficacy and mortality. RESULTS: The patient cohort was divided into PMB-based regimen group (n = 98, 35.5%) and CAZ/AVI-based regimen group (n = 178, 64.5%). Compared to the PMB group, the CAZ/AVI group exhibited significantly higher rates of clinical efficacy (71.3% vs. 56.1%; p = 0.011), microbiological clearance (74.7% vs. 41.4%; p < 0.001), and a lower incidence of acute kidney injury (AKI) (13.5% vs. 33.7%; p < 0.001). Binary logistic regression revealed that the treatment duration independently influenced both clinical efficacy and microbiological clearance. Vasoactive drugs, sepsis/septic shock, APACHE II score, and treatment duration were identified as risk factors associated with 30-day all-cause mortality. The CAZ/AVI-based regimen was an independent factor for good clinical efficacy, microbiological clearance, and lower AKI incidence. CONCLUSIONS: For patients with CRKP infection, the CAZ/AVI-based regimen was superior to the PMB-based regimen.

2.
Inorg Chem ; 2024 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-39436811

RESUMEN

Transition-metal-catalyzed enantioselective C-O bond constructions via hydrofunctionalization involving the use of O-based nucleophiles are an important topic in synthetic chemistry. Herein, density functional theory calculations were conducted to unveil the mechanism and enantioselectivity of Pd-catalyzed asymmetric hydrofunctionalization of conjugated dienes. We found that the base-assisted 4,3-activation model of the ligand-to-ligand hydrogen transfer (LLHT) mechanism is the most preferred one among all the cases, which could be ascribed to the favorable C-H···O interactions and the electrostatic interactions. For the enantioselective C-O bond formation process, the orientation of the substrate in the chiral pocket plays a significant role in controlling the enantioselectivity by contributing different noncovalent interactions. On the basis of the distortion/interaction model and energy decomposition analysis, the distortion energy is identified as the dominant factor controlling the product chemoselectivity. BnOH acts as the substrate, proton shuttle, and stabilizer to facilitate the H-transfer process in both LLHT and the C-O bond formation process. This study provides molecular-level insights into the collaborative effect of the base and P,N-ligand to perform the catalytic activity in the asymmetric hydrofunctionalization of conjugated dienes, which might open a new avenue for designing more efficient base-assisted enantioselective hydrofunctionalization by Pd catalysis.

3.
Cell ; 138(6): 1236-46, 2009 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-19747717

RESUMEN

The eukaryotic circadian oscillators consist of autoregulatory negative feedback loops. However, little is known about the role of posttranscriptional regulation of RNA in circadian oscillators. In the Neurospora circadian negative feedback loop, FRQ and FRH form the FFC complex that represses frq transcription. Here, we show that FFC also binds frq RNA and interacts with the exosome to regulate frq RNA decay. Consequently, frq RNA is robustly rhythmic as it is more stable when FRQ levels are low. Silencing of RRP44, the catalytic subunit of the exosome, elevates frq RNA levels and impairs clock function. In addition, rrp44 is a clock-controlled gene and a direct target of the WHITE COLLAR complex, and RRP44 controls the circadian expression of some ccgs. Taken together, these results suggest that FFC and the exosome are part of a posttranscriptional negative feedback loop that regulates frq transcript levels and the circadian output pathway.


Asunto(s)
Ritmo Circadiano , Exosomas/metabolismo , Regulación Fúngica de la Expresión Génica , Neurospora/genética , Relojes Biológicos , Proteínas Fúngicas/metabolismo , Neurospora/metabolismo , Procesamiento Postranscripcional del ARN
4.
Int J Phytoremediation ; 26(4): 524-534, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37641540

RESUMEN

Mercury (Hg) pollution has seriously threatened the crop productivity and food security. In the present research, experiments were conducted to assess the influence of nanoscale sulfur/sulfur nanoparticles and the corresponding bulk and ionic sulfur forms on the growth and Hg accumulation of oilseed rape seedlings grown on Hg-contaminated soil, as well as the transformation of soil Hg fractions. The results showed a significant reduction in fresh biomass for seedlings grown on 80-200 mg/kg Hg-polluted soil after 30 days. At 120 mg/kg Hg treatment, 100-300 mg/kg sulfur nanoparticles (SNPs) application counteracted Hg toxicity more effectively compared to the corresponding bulk sulfur particles (BSPs) and ionic sulfur (sulfate) treatments. The seedlings treated with 120 mg/kg Hg + 300 mg/kg SNPs gained 54.2 and 56.9% more shoot and root biomass, respectively, compared to those treated with Hg alone. Meanwhile, 300 mg/kg SNPs application decreased Hg accumulation by 18.9 and 76.5% in shoots and roots, respectively, relative to Hg alone treatment.SNPs treatment caused more Hg to be blocked in the soil and accumulating significantly less Hg in plants as compared to other S forms. The chemical fractions of Hg in the soil were subsequently investigated, and the solubility of Hg was significantly decreased by applying SNPs to the soil. Especially 200-300 mg/kg SNPs treatments caused the ratio of the soluble/exchangeable and the specifically absorbed fraction to be the lowest, accounting for 1.95-4.13% of the total Hg of soil. These findings suggest that adding SNPs to Hg-contaminated soils could be an effective measure for immobilizing soluble Hg and decreasing the Hg concentration in the edible parts of crops. The results of the current study hold promise for the practical application of SNPs to Hg-contaminated farmland for better yields and simultaneously increasing the food safety.


The novelty of this study is the selection of oilseed rape and nanoscale sulfur (NS) or sulfur nanoparticles (SNPs) as nontoxic nanomaterial to counteract the Hg toxicity and accumulation. Oilseed rape was selected due to its wide adaptability to various environmental conditions and the high-value oil for human consumption and biofuels production. These advantages make oilseed rape a highly valuable crop for various applications. NS was selected due to its reported ability to limit the uptake of heavy metals in oilseed rape, rice, and wheat along with other crops and subsequently restrict the toxicity of heavy metals in these plants and improve food safety. In this study, we evaluated the growth, Hg accumulation, and the resulting toxicity in oilseed rape grown on Hg-contaminated soil, with or without amendments with NS. The outcomes from this study provided evidence of the significant potential of NS in preventing Hg bioaccumulation and improving crop yields in oilseed rape. This provides opportunity to use NS as an ideal non-GMO approach to limit toxic metals in crops.


Asunto(s)
Brassica napus , Mercurio , Contaminantes del Suelo , Plantones/química , Biodegradación Ambiental , Suelo , Azufre , Contaminantes del Suelo/análisis , Cadmio
5.
Int J Phytoremediation ; 26(10): 1545-1555, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38597454

RESUMEN

In the present study, experiments were conducted to assess the influence of nanoscale sulfur in the microbial community structure of metallophytes in Hg-contaminated rhizosphere soil for planting rapeseed. The results showed that the richness and diversity of the rhizobacteria community decreased significantly under Hg stress, but increased slightly after SNPs addition, with a reduction in the loss of Hg-sensitive microorganisms. Moreover, all changes in the relative abundances of the top ten phyla influenced by Hg treatment were reverted when subjected to Hg + SNPs treatment, except for Myxococcota and Bacteroidota. Similarly, the top five genera, whose relative abundance decreased the most under Hg alone compared to CK, increased by 19.05%-54.66% under Hg + SNPs treatment compared with Hg alone. Furthermore, the relative abundance of Sphingomonas, as one of the dominant genera for both CK and Hg + SNPs treatment, was actively correlated with plant growth. Rhizobacteria, like Pedobacter and Massilia, were significantly decreased under Hg + SNPs and were positively linked to Hg accumulation in plants. This study suggested that SNPs could create a healthier soil microecological environment by reversing the effect of Hg on the relative abundance of microorganisms, thereby assisting microorganisms to remediate heavy metal-contaminated soil and reduce the stress of heavy metals on plants.


In this manuscript, we first comprehensively investigated the changes in the rhizosphere microbial community structure of metallophytes in Hg-contaminated soil with SNPs addition, as well as the relationship between soil microbiology and plant resistance to Hg stress. Our results demonstrated that SNPs exhibit a significant advantage in improving rhizosphere microecology by increasing the abundance of beneficial rhizobacteria, thereby alleviating heavy metal toxicity, and promoting plant growth. This study is the first study describing the response of soil microorganisms coexposed to heavy metals and SNPs, providing valuable information for the potential use of SNPs to assist phytoremediation of toxic metal pollution and its impact on soil microbial communities.


Asunto(s)
Biodegradación Ambiental , Mercurio , Microbiota , Nanopartículas , Rizosfera , Microbiología del Suelo , Contaminantes del Suelo , Azufre , Mercurio/metabolismo , Contaminantes del Suelo/metabolismo , Bacterias/metabolismo , Brassica rapa , Brassica napus/microbiología
6.
J Environ Manage ; 354: 120486, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38417363

RESUMEN

Alterations in water regimes or nitrogen (N) availability lead to shifts in the assemblage of rhizosphere microbial community; however, how the rhizosphere microbiome response to concurrent changes in water and N availability remains largely unclear. Herein, we investigated the taxonomic and functional characteristics of rhizobacteria associated with stevia (Stevia rebaudiana Bertoni) under varying combinations of water and N levels. Community diversity and predicted functions of rhizobacteria were predominantly altered by drought stress, with N-starvation modulating these effects. Moreover, N fertilization simplified the ecological interactions within rhizobacterial communities and heightened the relative role of stochastic processes on community assembly. In terms of rhizobacterial composition, we observed both common and distinctive changes in drought-responsive bacterial taxa under different N conditions. Generally, the relative abundance of Proteobacteria and Bacteroidetes phyla were depleted by drought stress but the Actinobacteria phylum showed increases. The rhizobacterial responses to drought stress were influenced by N availability, where the positive response of δ-proteobacteria and the negative response of α- and γ-proteobacteria, along with Bacteroidetes, were further heightened under N starvation. By contrast, under N fertilization conditions, an amplified negative or positive response to drought were demonstrated in Firmicutes and Actinobacteria phyla, respectively. Further, the drought-responsive rhizobacteria were mostly phylogenetically similar, but this pattern was modulated under N-rich conditions. Overall, our findings indicate an N-dependent specific restructuring of rhizosphere bacteria under drought stress. These changes in the rhizosphere microbiome could contribute to enhancing plant stress tolerance.


Asunto(s)
Actinobacteria , Stevia , Sequías , Bacterias , Proteobacteria , Rizosfera , Agua , Microbiología del Suelo
7.
J Org Chem ; 88(23): 16132-16143, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38037695

RESUMEN

Comprehensive computational studies were carried out to explore the mechanisms and origin of regioselectivity in the Pd-catalyzed regiodivergent coupling reaction of indazoles and isoprene. Three different insertion models were investigated for regioselectivity 1,2- or 4,3-insertion with respect to the electrophilic sites on isoprene under two different ligands (L1 and L2) and acids ((PhO)2PO2H, (nBuO)2PO2H) via PdII-H species, allyl-π-PdII-O, and indazoles-acid-assisted PdII-π-allyl. The calculated results show that the PdII-π-allyl coordinated mechanism is the most preferred one. The noncovalent interactions between the less bulky ligand L1, substrates, and (PhO)2PO2- are found to be key factors for 1,2-insertion. The 4,3-insertion selectivity is primarily controlled by the steric repulsion of the t-Bu group of bulky ligand L2 and substrate, as well as the geometry distortion. Therefore, the regioselectivity difference of the 1,2- and 4,3-insertion on electrophilic sites is controlled by the synergistic effect of ligands and acids instead of the size of the ligand. Similarly, nucleophilic site selectivity at N1 or N2 of indazoles is governed by cooperative acid BF3 and solvent iPrOH rather than BF3 alone. Overall, our findings might open a new avenue for designing more efficient regioselective 1,2- or 4,3-addition or N1-/N2-selective nucleophilic reactions.

8.
Eur Spine J ; 32(1): 149-166, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36450863

RESUMEN

PURPOSE: Osteoporosis is a risk factor for idiopathic scoliosis (IS) progression, but it is still unclear whether IS patients have bone mineral density (BMD) loss and a higher risk of osteoporosis than asymptomatic people. This systematic review aims to explore the differences in BMD and prevalence of osteoporosis between the IS group and the control group. METHODS: We searched 5 health science-related databases. Studies that were published up to February 2022 and written in English and Chinese languages were included. The primary outcome measures consisted of BMD z score, the prevalence of osteoporosis and osteopenia, and areal and volumetric BMD. Bone morphometry, trabecular microarchitecture, and quantitative ultrasound measures were included in the secondary outcome measures. The odds ratio (OR) and the weighted mean difference (WMD) with a 95% confidence interval (CI) were used to pool the data. RESULTS: A total of 32 case-control studies were included. The pooled analysis revealed significant differences between the IS group and the control group in BMD z score (WMD -1.191; 95% CI - 1.651 to -0.732, p < 0.001). Subgroup analysis showed significance in both female (WMD -1.031; 95% CI -1.496 to -0.566, p < 0.001) and male participants (WMD -1.516; 95% CI -2.401 to -0.632, p = 0.001). The prevalence of osteoporosis and osteopenia in the group with IS was significantly higher than in the control group (OR = 6.813, 95% CI 2.815-16.489, p < 0.001; OR 1.879; 95% CI 1.548-2.281, p < 0.000). BMD measures by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography showed a significant decrease in the IS group (all p < 0.05), but no significant difference was found in the speed of sound measured by quantitative ultrasound between the two groups (p > 0.05). CONCLUSION: Both the male and female IS patients had a generalized lower BMD and an increased prevalence of osteopenia and osteoporosis than the control group. Future research should focus on the validity of quantitative ultrasound in BMD screening. To control the risk of progression in IS patients, regular BMD scans and targeted intervention are necessary for IS patients during clinical practice.


Asunto(s)
Enfermedades Óseas Metabólicas , Osteoporosis , Escoliosis , Humanos , Masculino , Femenino , Niño , Adulto Joven , Densidad Ósea , Escoliosis/diagnóstico por imagen , Escoliosis/epidemiología , Escoliosis/complicaciones , Osteoporosis/diagnóstico por imagen , Osteoporosis/epidemiología , Osteoporosis/complicaciones , Enfermedades Óseas Metabólicas/diagnóstico por imagen , Enfermedades Óseas Metabólicas/epidemiología , Enfermedades Óseas Metabólicas/complicaciones , Absorciometría de Fotón
9.
J Environ Manage ; 345: 118721, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37536134

RESUMEN

Forest soil is a vital pool of organic carbon, which is sensitive to management. Biochar addition could change the CO2 emissions from soil, but its effects are still ambiguous. Moreover, the impacts of particle sizes of biochar on CO2 emissions are still unknown. In this study, a series of field experiments were conducted to investigate the effects of biochar addition on CO2 emissions in a poplar plantation (Populus nigra), China. Biochar with two application rates of (10 and 50 t/ha) and three particle sizes (3-1 mm, 1-0.1 mm, and <0.1 mm) was applied into the surface soil (0-10 cm), and the soil without biochar was set as control. The results showed that a high level of fine biochar addition (1-0.1 mm and <0.1 mm) had similar and positive effects on CO2 emissions by increasing the contents of soil ammonium, available phosphorus, easily oxidizable carbon, soil moisture, soil capillary pore, and the activity of ß-glucosidase. However, biochar addition (1-0.1 mm and <0.1 mm) reduced the bioavailability of dissolved organic carbon (DOC), producing a negative relationship between DOC content and CO2 emissions. This investigation highlights the importance of biochar with different particle sizes in adjusting CO2 emissions from temperate soils.


Asunto(s)
Dióxido de Carbono , Populus , Dióxido de Carbono/análisis , Tamaño de la Partícula , Ríos , Carbón Orgánico , Carbono , Suelo , China , Óxido Nitroso/análisis , Agricultura
10.
J Environ Sci (China) ; 124: 319-329, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36182142

RESUMEN

Experiments were performed to explore the impact of sulfur nanoparticles (SNPs) on growth, Cu accumulation, and physiological and biochemical responses of oilseed rape (Brassica napus L.) inoculated with 5 mg/L Cu-amended MS medium supplemented with or without 300 mg/L SNPs exposure. Cu exerted severe phytotoxicity and inhibited plant growth. SNPs application enhanced the shoot height, root length, and dry weight of shoot and root by 34.6%, 282%, 41.7% and 37.1%, respectively, over Cu treatment alone, while the shoot and root Cu contents and Cu-induced lipid perodixation as the malondialdehyde (MDA) levels in shoots and roots were decreased by 37.6%, 35%, 28.4% and 26.8%. Further, the increases in superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione S-transferase (GST) enzyme activities caused by Cu stress were mitigated in shoots (10.9%-37.1%) and roots (14.6%-35.3%) with SNPs addition. SNPs also positively counteracted the negative effects on shoot K, Ca, P, Mg, Mn, Zn and Fe contents and root K, Ca, Mg and Mn contents from Cu exposure alone, and significantly promoted the nutrients accumulation in plant. Additionally, in comparison with common bulk sulfur particles (BSPs) and sulfate, SNPs showed more positive effects on promoting growth in shoots (6.7% and 19.5%) and roots (10.9% and 15.1%), as well as lowering the shoot Cu content (40.1% and 43.3%) under Cu stress. Thus, SNPs application has potential to be a green and sustainable technology for increasing plant productivity and reducing accumulation of toxic metals in heavy metal polluted soils.


Asunto(s)
Brassica napus , Metales Pesados , Nanopartículas , Antioxidantes/metabolismo , Ascorbato Peroxidasas/metabolismo , Brassica napus/metabolismo , Catalasa/metabolismo , Glutatión Reductasa/metabolismo , Glutatión Reductasa/farmacología , Glutatión Transferasa , Peróxido de Hidrógeno , Lípidos/farmacología , Malondialdehído , Metales Pesados/farmacología , Estrés Oxidativo , Peroxidasas , Raíces de Plantas/metabolismo , Suelo , Sulfatos , Azufre , Superóxido Dismutasa/metabolismo
11.
J Org Chem ; 87(24): 16604-16616, 2022 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-36469572

RESUMEN

A photocatalyst-free radical cleavage of α-diazo sulfonium salts has been developed for the first time. The reaction provides an efficient method for the generation of diazomethyl radicals from α-diazosulfonium triflates under photochemical conditions. Utilizing the in situ generated diazomethyl radicals as key intermediate, the coupling cyclization reaction of α-diazosulfonium triflates with α-oxocarboxylic acids or alkynes has been achieved. The method affords a diverse set of important 2,5-disubstituted 1,3,4-oxadiazoles and 3,5-disubstituted-1H-pyrazoles with excellent regioselectivity in a single step. A reaction mechanism involving a radical pathway was further supported by control experiments and DFT calculations.

12.
BMC Health Serv Res ; 22(1): 299, 2022 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-35246117

RESUMEN

BACKGROUND: The COVID-19 pandemic has exerted an unprecedented and universal impact on global health system, resulting in noticeable challenges in traditional chronic disease care, of which diabetes was reported to be most influenced by the reduction in healthcare resources in the pandemic. China has the world's largest diabetes population, and current diabetes management in China is unsatisfactory, particularly in rural areas. Studies in developed countries have demonstrated that physician-pharmacist collaborative clinics are efficient and cost-effective for diabetes management, but little is known if this mode could be adapted in primary hospitals in China. The aim of this proposed study is to develop and evaluate physician-pharmacist collaborative clinics to manage type 2 diabetes mellitus (T2DM) in primary hospitals in Hunan province. METHODS: A multi-site randomized controlled trial will be conducted to evaluate the effectiveness and cost-effectiveness of the physician-pharmacist collaborative clinics compared with usual care for Chinese patients with T2DM. Six primary hospitals will participate in the study, which will recruit 600 eligible patients. Patients in the intervention group will receive services from both physicians and pharmacists in the collaborative clinics, while the control group will receive usual care from physicians. Patients will be followed up at the 3rd, 6th, 9th and 12th month. Comparison between the two groups will be conducted by assessing the clinical parameters, process indicators and costs on diabetes. A satisfaction survey will also be carried out at the end of the study. DISCUSSION: If effective, the physician-pharmacist collaborative clinics can be adapted and used in primary hospitals of China to improve glycemic control, enhance medication adherence, decrease incidence of complications and reduce patients' dependence on physicians. Findings from the present study are meaningful for developing evidence-based diabetes care policy in rural China, especially in the COVID-19 pandemic era. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2000031839 , Registered 12 April 2020.


Asunto(s)
COVID-19 , Diabetes Mellitus Tipo 2 , Relaciones Interprofesionales , Farmacéuticos , Médicos , COVID-19/epidemiología , China/epidemiología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/epidemiología , Hospitales , Humanos , Estudios Multicéntricos como Asunto , Pandemias , Ensayos Clínicos Controlados Aleatorios como Asunto
13.
J Org Chem ; 86(5): 4121-4130, 2021 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-33617248

RESUMEN

Computational studies of chiral phosphoric acid (CPA)-catalyzed dynamic kinetic asymmetric hydroamination (DyKAH) of racemic allenes show that the reaction proceeds through a catalytic asymmetric model involving a highly reactive π-allylic carbocationic intermediate, generated from a racemic allene through an intermolecular proton transfer mediated by CPA, which also results in a high E/Z selectivity. Moreover, the distortion-interaction, atom in molecule, and electrostatic interaction analyses and space-filling models are employed on the basis of the DyKAH catalyzed by (S)-A5 (reaction 1) or (R)-A2 (reaction 2) to explain the high enantioselectivity and the controlling effects of SPINOL scaffolds on the signs of enantioselectivity. Our calculations indicate that the enantioselectivity of reactions 1 and 2 can be mainly ascribed to the favorable noncovalent interactions within the stronger chiral electrostatic environment created by the phosphoric acid in the preferential transition states. Finally, the effect of (S/R)-SPINOL-based CPAs on the signs of enantioselectivity can be explained by the different combination modes of substrates into the chiral binding pocket of the catalyst controlled by the chirality of SPINOL backbones. Overall, the new insights into the reaction rationalize the outcome and these key factors that affect the product enantioselectivity are important to guide the DyKAHs.


Asunto(s)
Fosfatos , Alcadienos , Catálisis , Ácidos Fosfóricos , Estereoisomerismo
14.
Inorg Chem ; 60(3): 1716-1725, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33471502

RESUMEN

Metal-organic frameworks (MOFs) and MOF-based composites as luminescent sensors with excellent economic practicability and handy operability have attracted much attention. Herein, we designed and fabricated a porous Zn-based MOF, [Zn(OBA)2(L1)·2DMA]n [1; H2OBA = 4,4'-oxybis(benzoic acid), L1 = 2,4,6-tris(4-pyridyl)pyridine, and DMA = N,N-dimethylacetamide], with mixed nodes under solvothermal conditions, and the pore size of 5.9 Å was calculated from N2 adsorption isotherms by using a density functional theory model. The as-synthesized compound 1 is stable in different boiling organic solvents and water solutions with a wide pH range of 2-12 and exhibits intense luminescence emission at 360 nm under excitation of 290 nm. Significantly, compound 1 shows high selective detection of Fe3+, CrO42-, and Cr2O72- in aqueous solution even under the interference of other ions. Compound 1 can quickly sense these ions in a short time and has a striking sensitivity toward Fe3+ with an ultralow limit of detection (LOD) of 1.06 µM. The relatively low LODs for CrO42- and Cr2O72- are 3.87 and 2.37 µM, respectively, compared to the reported works. Meanwhile, compound 1 can be reused to detect Fe3+, CrO42-, and Cr2O72- six times by simple regeneration. Considering the practicability, a mixed-matrix membrane (MMM) incorporated compound 1 and poly(methyl methacrylate) has been constructed. This MMM displays quick detection of Fe3+, CrO42-, and Cr2O72- and prompt regeneration by lifting from the analyte. This useful MMM shows a comparable LOD below 4.35 µM for these ions. This work presents a cost-effective Zn-based MOF as a functional platform for simple but useful sensing of Fe3+, CrO42-, and Cr2O72- in aqueous solution.

15.
Environ Sci Technol ; 55(20): 13490-13503, 2021 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-34570468

RESUMEN

Rice is known to accumulate arsenic (As) in its grains, posing serious health concerns for billions of people globally. We studied the effect of nanoscale sulfur (NS) on rice seedlings and mature plants under As stress. NS application caused a 40% increase in seedling biomass and a 26% increase in seed yield of mature plants compared to untreated control plants. AsIII exposure caused severe toxicity to rice; however, coexposure of plants to AsIII and NS alleviated As toxicity, and growth was significantly improved. Rice seedlings treated with AsIII + NS produced 159 and 248% more shoot and root biomass, respectively, compared to plants exposed to AsIII alone. Further, AsIII + NS-treated seedlings accumulated 32 and 11% less As in root and shoot tissues, respectively, than the AsIII-alone treatment. Mature plants treated with AsIII + NS produced 76, 110, and 108% more dry shoot biomass, seed number, and seed yield, respectively, and accumulated 69, 38, 18, and 54% less total As in the root, shoot, flag leaves, and grains, respectively, compared to AsIII-alone-treated plants. A similar trend was observed in seedlings treated with AsV and NS. The ability of sulfur (S) to alleviate As toxicity and accumulation is clearly size dependent as NS could effectively reduce bioavailability and accumulation of As in rice via modulating the gene expression activity of As transport, S assimilatory, and glutathione synthesis pathways to facilitate AsIII detoxification. These results have significant environmental implications as NS application in agriculture has the potential to decrease As in the food chain and simultaneously enable crops to grow and produce higher yields on marginal and contaminated lands.


Asunto(s)
Arsénico , Oryza , Contaminantes del Suelo , Arsénico/toxicidad , Humanos , Raíces de Plantas/química , Plantones , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad , Azufre
16.
Plant Cell Rep ; 40(9): 1709-1722, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34129077

RESUMEN

KEY MESSAGE: Transcriptome analysis revealed the potential mechanism of nitrogen regulating steviol glycosides synthesis via shifting of leaf carbon metabolic flux or inducing certain transcription factors. Nitrogen (N) plays key regulatory roles in both stevia (Stevia rebaudiana) growth and the synthesis of its functional metabolite steviol glycosides (SGs), but the mechanism by which this nutrient regulates SGs synthesis remains to be elucidated. To address this question, a pot experiment was performed in a greenhouse where stevia plants fertilized with N (the control as CK plants) and compared with plants without the supply of N. Physiological and biochemical analyses were conducted to test the growth and metabolic responses of plants to N regimes. Our results showed that N deficiency significantly inhibited plant growth and leaf photosynthesis, while increased leaf SGs contents in stevia (49.97, 46.64 and 84.80% respectively for rebaudioside A, stevioside, and rebaudioside C), which may be partly due to "concentration effect". Then, transcriptome analysis was conducted to understand the underlying mechanisms. A total of 535 differentially expressed genes were identified, and carbon metabolism-related events were highlighted by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Many of these genes were significantly upregulated by N-deficiency, including those involved in "phenylpropanoid biosynthesis", "flavonoid biosynthesis" and "starch and sucrose metabolism". Our study also analyzed the expression patterns of SGs synthesis-related genes under two N regimes and the potential transcription factors linking N nutrition and SG metabolism. N-deficiency may promote SGs synthesis by changing the carbon metabolism flux or inducing certain transcription factors. Our results provide deeper insight into the relationship between N nutrition and SGs synthesis in stevia plants.


Asunto(s)
Diterpenos de Tipo Kaurano/metabolismo , Hojas de la Planta/metabolismo , Stevia/genética , Stevia/metabolismo , Carbono/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Glucósidos/metabolismo , Glicósidos/metabolismo , Nitrógeno/metabolismo , Oligosacáridos/metabolismo , Hojas de la Planta/genética , Proteínas de Plantas/genética , Reproducibilidad de los Resultados , Stevia/crecimiento & desarrollo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
17.
J Clin Lab Anal ; 35(3): e23656, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33314296

RESUMEN

BACKGROUND: The present study aimed to explore the correlation of long non-coding RNA highly up-regulating in liver cancer (lncRNA HULC) with disease risk, inflammatory cytokines, biochemical indexes, disease severity, infective features, and 28-day mortality of sepsis. METHODS: Totally 174 sepsis patients and 100 controls were enrolled. Peripheral blood samples were collected from sepsis patients after diagnosis and from controls at enrollment, respectively, and further for separation of peripheral blood mononuclear cell (PBMC) and serum samples. PBMC samples were for lncRNA HULC detection, and serum samples were for inflammatory cytokine detection. RESULTS: LncRNA HULC expression was increased in sepsis patients compared with controls. Moreover, lncRNA HULC was positively associated with TNF-α, IL-6, IL-17, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, serum creatinine, white blood cell, and C-reactive protein in sepsis patients, but not in controls. Furthermore, in sepsis patients, lncRNA HULC expression was positively correlated with acute physiology and chronic health evaluation II score and sequential organ failure assessment score, but not correlated with primary infection sites or primary infection organisms; meanwhile, lncRNA HULC expression was increased in deaths compared with survivors; subsequent receiver operating characteristic curve indicated that lncRNA HULC presented good value in predicting increased 28-day mortality (AUC: 0.785, 95% CI: 0.713-0.857), and its independent predictive value for mortality was also verified by multivariate analysis. CONCLUSION: LncRNA HULC is correlated with higher disease risk, severity, and inflammation and serves as an independent factor for predicting increased mortality, suggesting its potential in promoting accuracy of prognostic prediction for sepsis management.


Asunto(s)
ARN Largo no Codificante/sangre , Sepsis/etiología , Sepsis/mortalidad , Adulto , Anciano , Estudios de Casos y Controles , Citocinas/sangre , Citocinas/genética , Femenino , Marcadores Genéticos , Humanos , Masculino , Persona de Mediana Edad , Puntuaciones en la Disfunción de Órganos , Sepsis/genética , Índice de Severidad de la Enfermedad
18.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-34445524

RESUMEN

The family of B-box (BBX) transcription factors contains one or two B-BOX domains and sometimes also features a highly conserved CCT domain, which plays important roles in plant growth, development and stress response. Nevertheless, no systematic study of the BBX gene family in Iris germanica L. has been undertaken. In this study, a set of six BBX TF family genes from I. germanica was identified based on transcriptomic sequences, and clustered into three clades according to phylogenetic analysis. A transient expression analysis revealed that all six BBX proteins were localized in the nucleus. A yeast one-hybrid assay demonstrated that IgBBX3 has transactivational activity, while IgBBX1, IgBBX2, IgBBX4, and IgBBX5 have no transcriptional activation ability. The transcript abundance of IgBBXs in different tissues was divided into two major groups. The expression of IgBBX1, IgBBX2, IgBBX3 and IgBBX5 was higher in leaves, whereas IgBBX4 and IgBBX6 was higher in roots. The stress response patterns of six IgBBX were detected under phytohormone treatments and abiotic stresses. The results of this study lay the basis for further research on the functions of BBX gene family members in plant hormone and stress responses, which will promote their application in I. germanica breeding.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Genoma de Planta , Género Iris/metabolismo , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Transcriptoma , Perfilación de la Expresión Génica , Género Iris/genética , Género Iris/crecimiento & desarrollo , Familia de Multigenes , Filogenia , Proteínas de Plantas/genética , Estrés Fisiológico , Factores de Transcripción/genética
19.
Int J Mol Sci ; 22(16)2021 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-34445254

RESUMEN

Nitrogen forms (nitrate (NO3-) or ammonium (NH4+)) are vital to plant growth and metabolism. In stevia (Stevia rebaudiana), it is important to assess whether nitrogen forms can influence the synthesis of the high-value terpene metabolites-steviol glycosides (SGs), together with the underlying mechanisms. Field and pot experiments were performed where stevia plants were fertilized with either NO3- or NH4+ nutrition to the same level of nitrogen. Physiological measurements suggested that nitrogen forms had no significant impact on biomass and the total nitrogen content of stevia leaves, but NO3--enhanced leaf SGs contents. Transcriptomic analysis identified 397 genes that were differentially expressed (DEGs) between NO3- and NH4+ treatments. Assessment of the DEGs highlighted the responses in secondary metabolism, particularly in terpenoid metabolism, to nitrogen forms. Further examinations of the expression patterns of SGs synthesis-related genes and potential transcription factors suggested that GGPPS and CPS genes, as well as the WRKY and MYB transcription factors, could be driving N form-regulated SG synthesis. We concluded that NO3-, rather than NH4+, can promote leaf SG synthesis via the NO3--MYB/WRKY-GGPPS/CPS module. Our study suggests that insights into the molecular mechanism of how SG synthesis can be affected by nitrogen forms.


Asunto(s)
Amoníaco/farmacología , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Glucósidos/biosíntesis , Nitratos/metabolismo , Stevia/metabolismo , Transcripción Genética/efectos de los fármacos , Diterpenos de Tipo Kaurano , Perfilación de la Expresión Génica , Glucósidos/genética , Nitratos/farmacología , Stevia/genética
20.
J Environ Sci Health B ; 56(8): 741-752, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34388056

RESUMEN

Using polyethylene wax (PW) as the coating matrix, the lambda-cyhalothrin-PW nanosuspoemulsion (LC-PW) with a particle size of 80-150nm was prepared through high-speed stirring, hot melt emulsification and ultrasonic dispersion. The formulation and composition of the LC-PW were optimized, the morphology of the LC-PW was analyzed by dynamic light scattering (DLS) and TEM, and the structure of the LC-PW was characterized by UV and IR. The anti-photolysis test showed that LC-PW had a good anti-photolysis performance. Furthermore, LC-PW could sustainably release Lambda-cyhalothrin, which was pH- and temperature dependent. The insecticidal activity analysis in the greenhouse indicated that the toxic strength between LC-PW and LC-SC (lambda-cyhalothrin-suspension concentrate) to Mythimna separata was similar within the same concentration ranges tested, but the insecticidal duration of LC-PW was significantly longer than LC-SC. Thus, the new type of LC-PW with the properties of anti-photolysis and controlled release is suitable for application in the field as a better insecticide.


Asunto(s)
Insecticidas , Piretrinas , Concentración de Iones de Hidrógeno , Nitrilos , Polietilenos , Temperatura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA