Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Sensors (Basel) ; 24(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38894145

RESUMO

Advanced glycation end-products (AGEs) are complex compounds closely associated with several chronic diseases, especially diabetes mellitus (DM). Current methods for detecting AGEs are not suitable for screening large populations, or for long-term monitoring. This paper introduces a portable autofluorescence detection system that measures the concentration of AGEs in the skin based on the fluorescence characteristics of AGEs in biological tissues. The system employs a 395 nm laser LED to excite the fluorescence of AGEs, and uses a photodetector to capture the fluorescence intensity. A model correlating fluorescence intensity with AGEs concentration facilitates the detection of AGEs levels. To account for the variation in optical properties of different individuals' skin, the system includes a 520 nm light source for calibration. The system features a compact design, measuring only 60 mm × 50 mm × 20 mm, and is equipped with a miniature STM32 module for control and a battery for extended operation, making it easy for subjects to wear. To validate the system's effectiveness, it was tested on 14 volunteers to examine the correlation between AGEs and glycated hemoglobin, revealing a correlation coefficient of 0.49. Additionally, long-term monitoring of AGEs' fluorescence and blood sugar levels showed a correlation trend exceeding 0.95, indicating that AGEs reflect changes in blood sugar levels to some extent. Further, by constructing a multivariate predictive model, the study also found that AGEs levels are correlated with age, BMI, gender, and a physical activity index, providing new insights for predicting AGEs content and blood sugar levels. This research supports the early diagnosis and treatment of chronic diseases such as diabetes, and offers a potentially useful tool for future clinical applications.


Assuntos
Produtos Finais de Glicação Avançada , Humanos , Produtos Finais de Glicação Avançada/análise , Feminino , Masculino , Adulto , Hemoglobinas Glicadas/análise , Pessoa de Meia-Idade , Glicemia/análise , Pele/química , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/sangue , Fluorescência , Imagem Óptica/métodos , Imagem Óptica/instrumentação , Espectrometria de Fluorescência/métodos
2.
Sensors (Basel) ; 24(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38894406

RESUMO

A two-axis stabilizing gimbal is a device that ensures a sensor is working properly on a moving platform. When classical mechanics (Newton-Euler and Lagrange) is employed to model a two-axis stable gimbal, its limitations can complicate the modeling process. To address this issue, a method for establishing a dynamic model for a two-axis stabilizing platform based on the Kane method is proposed in this paper. The Kane method offers the advantage of a simple model structure and computational efficiency. Initially, utilizing a generalized coordinate system, expressions of the generalized velocities, deflection velocities and angular velocities are derived. Subsequently, the generalized active forces and inertial forces acting on the two-axis stabilized gimbal are analyzed. Finally, by combining force and velocity with the Kane equation, the dynamic model of the two-axis stable platform is obtained, demonstrating the validity of the Kane method for establishing the two-axis stable platform model. To ensure the pointing accuracy stability of the two-axis stabilizing platform, a Novel Particle Swarm Optimization Proportion Integration Differentiation (NPSO-PID) controller is designed using the PSO algorithm. It is then simulated in MATLAB/Simulink and compared with a classical PID controller. Simulation results demonstrate that NPSO-PID exhibits superior object tracking performance compared to classical PID controllers and better optimization of control parameters compared to traditional PSO-PID controllers.

3.
Langmuir ; 39(20): 7212-7220, 2023 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-37172413

RESUMO

With increasing awareness about the ecological environment, increased attention has been paid to the application of eco-friendly materials in the field of marine antifouling. In this work, a novel coating having good mechanical strength and static marine antifouling characteristics was fabricated using cellulose nanocrystals (CNCs) as the skeleton material, with in situ growth of SiO2 as the basic superhydrophobic material and introducing hexadecyl trimethyl ammonium bromide (CTAB) and 4-bromo2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile (Econea) into the coating. Due to the high strength and rod structure of CNCs, the coating maintained super-hydrophobicity after 50 cycles of abrasion tests. Moreover, the addition of CTAB during the synthesis of SiO2 led to the hydrolysis and polycondensation of tetraethyl orthosilicate at the micellar interface. Econea was fully mixed with SiO2 nanoparticles, thus slowing down the rate of release of Econea. Meanwhile, the adhesion between the coating and the substrate reached 1.9 MPa, which can meet the application requirements for marine environments. The bioassay using bacteria (Escherichia coli) and diatoms (Nitzschia closterium) showed that the rate of inhibition of the coating on bacteria and diatoms could reach 99 and 90%, respectively, after immersion in artificial seawater for 28 days. This research provides a facile and promising fabricating solution of an eco-friendly CNC-based coating having strong antifouling characteristics suitable for marine environments.


Assuntos
Incrustação Biológica , Diatomáceas , Desinfetantes , Nanopartículas , Celulose/química , Incrustação Biológica/prevenção & controle , Cetrimônio , Dióxido de Silício , Nanopartículas/química
4.
Water Sci Technol ; 85(10): 2912-2927, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35638796

RESUMO

Degradation mechanism of methyl orange (MO), a typical azo dye, with pyrite (FeS2) activated persulfate (PS) was explored. The results showed that when the initial concentration of MO was 0.1 mM, FeS2 was 1.6 g/L and PS was 1.0 mM, the removal rate of MO could reach 92.9% in 150 min, and the removal rate of total organic carbon could reach 14.1%. In addition, both pH ≤ 2 and pH ≥ 10 could have an inhibitory effect in the FeS2/PS system. Furthermore, Cl- and low concentrations of HCO-3 had little effect on the degradation of MO with FeS2/PS. However, H2PO-4 and high concentrations of HCO-3 could inhibit the degradation of MO in the system. Besides, MO in river water and tap water were not degraded in FeS2/PS system, but acidification (pH = 4) would greatly promote the degradation. In addition, the removal rate of MO with FeS2/PS could still reach about 90% after five cycles of FeS2. Furthermore, the intermediates and possible degradation pathways were speculated by LC-MS, and the degradation mechanism of MO by FeS2/PS was that the cycle of Fe(III)/Fe(II) could continuously activate persulfate to produce SO4•-. The results could provide technical support for azo dye degradation in the FeS2/PS system.


Assuntos
Sulfatos , Água , Compostos Azo , Compostos Férricos , Ferro , Sulfetos
5.
Med Sci Monit ; 26: e920445, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32107363

RESUMO

BACKGROUND Cerebral ischemia/reperfusion (I/R) injury contributes to mortality and morbidity in preterm infants. Curcumin has been shown to exert neuro-protective effects in the central nervous system (CNS). The aim of this study was to investigate the neuro-protective activity of curcumin and the possible underlying molecular mechanisms. MATERIAL AND METHODS A hypoxia/reoxygenation (H/R) protocol was used to simulate I/R injury in vitro. Isolated neonatal neurons were pre-treated with curcumin at serially diluted concentrations and exposed to H/R injury. Cell viability and apoptosis were assessed by MTT and flow cytometry, respectively. Contents of TNFa and IL6 in supernatant of cell culture medium were detected by ELISA. Protein expression, phosphorylation, and nuclear translocation levels were studied by Western blotting. RESULTS H/R reduced cell viability and increased apoptosis of neurons. H/R significantly increased Wnt5a expression, JNK1 phosphorylation, and NF-kappaB nuclear translocation. Moreover, expression levels of cleaved caspase3, TNFalpha, and IL6 were elevated in H/R-exposed neurons. Curcumin pre-treatment significantly increased cell viability and inhibited apoptosis of neurons exposed to H/R, in a concentration-dependent manner. Moreover, curcumin pre-treatment significantly decreased expression levels of Wnt5a, IL6, TNFalpha, and phosphorylation level of JNK1, as well as the nuclear translocation level of NF-kappaB in H/R-exposed neurons, in a concentration-dependent manner. CONCLUSIONS Curcumin exerted neuro-protective effects against H/R-induced neuron apoptosis and inflammation by inhibiting activation of the Wnt/JNK1 signaling pathway.


Assuntos
Curcumina/farmacologia , Neurônios/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Curcumina/metabolismo , Feminino , Feto , Hipóxia/metabolismo , Inflamação/metabolismo , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Gravidez , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos
6.
Hum Mutat ; 40(4): 380-391, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30585370

RESUMO

Though many mutations have been identified to be associated with the occurrence of congenital cataract, pathogenic loci in some affected families are still unknown. Clinical data and genomic DNA were collected from a four-generation Chinese family. Candidate mutations were independently verified for cosegregation in the whole pedigree. Linkage analysis showed that the disease-causing mutation was located between 1p36.21 and 1p36.33. Analysis of the whole-exome sequencing data combined with linkage analysis identified a novel pathogenic variant (g.2451906C>T) at intron 4 of Pantothenate kinase 4 (PANK4 protein, PANK4 gene) in 1p36.32|606162. This variant showed complete cosegregation with the phenotype in the pedigree. The mutation was not detected in 106 normal controls nor in 40 sporadic congenital cataract patients. The mutation was demonstrated to significantly reduce the expression of the PANK4 protein level in the blood of cataract patients than that in normal individuals by ELISA. Pank4-/- mice showed a cataract phenotype with increased numbers of apoptotic lens epithelial cells, fiber cell aggregation, and significant mRNA variation of crystallin family members. Thus, the association of a new entity of an autosomal dominant cataract with mutations in PANK4, which influences cell proliferation, apoptosis of lens epithelial cells, crystallin abnormalities, and fiber cell derangement, subsequently induces cataract.


Assuntos
Catarata/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Mutação , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Alelos , Animais , Apoptose/genética , Catarata/diagnóstico , Linhagem Celular , Análise Mutacional de DNA , Modelos Animais de Doenças , Expressão Gênica , Ligação Genética , Genótipo , Humanos , Camundongos , Linhagem , Fenótipo , Sequenciamento do Exoma
7.
J Cell Biochem ; 120(10): 17912-17925, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31135072

RESUMO

OBJECTIVE: To investigate the regulation of special protein 1 (SP1) and hypoxia-inducible factor-1α (HIF1α) on human microvascular endothelial cells (HMEC-1) under hypoxic conditions. METHODS: The expression of SP1 and HIF1α under normoxia and hypoxic conditions were assessed by Western blot. SP1 and HIF1α were knocked down by small interfering RNA (siRNA) under hypoxic conditions. The proliferation, migration, and invasion of HMEC-1 were measured by cell counting kit 8, 5-ethynyl-2'-deoxyuridine and Transwell coculture system. Western blot analysis and Immunofluorescence were carried out to study the mechanisms of simultaneously inhibiting the adenosine triphosphatase (CD39), 5'-nucleotidase (CD73), adenosine, and vascular endothelial growth factor (VEGF). We compared the inhibitory effects between groups concurrently interfering SP1, HIF-1α, and ranibizumab under hypoxic conditions. RESULTS: Under hypoxic conditions, the protein expression of SP1 and HIF1α was increased in HMEC-1, contrarily, SP1 siRNA and HIF1α siRNA downregulated the expression. Simultaneous inhibition of SP1 and HIF1α demonstrated a much greater restraint of proliferation, migration, and invasion characteristics on HMEC-1 than respectively knocking down SP1 or HIF1α and anti-VEGF drugs (0.5 mg/mL ranibizumab) (siRNA and the VEGF inhibitor were applied separately in different groups). Meanwhile, simultaneous inhibition of SP1 and HIF1α effectively reduced the expression of CD39, CD73, adenosine, and VEGF on HMEC-1 under hypoxic conditions. CONCLUSIONS: Our study demonstrated that both SP1 and HIF1α played important roles in HMEC-1 under hypoxia condition. Simultaneous inhibition of SP1 and HIF1α effectively decreased the activity of HMEC-1 under hypoxic conditions through the CD39-CD73-adenosine and VEGF angiogenesis pathways. Our study may provide a new approach to the treatment of retinal neovascular diseases.


Assuntos
Movimento Celular , Células Endoteliais/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Microvasos/patologia , Fator de Transcrição Sp1/metabolismo , Adenosina/farmacologia , Antígenos CD/metabolismo , Hipóxia Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Inativação Gênica/efeitos dos fármacos , Humanos , RNA Interferente Pequeno/metabolismo , Ranibizumab/farmacologia , Regulação para Cima/efeitos dos fármacos
8.
J Sci Food Agric ; 98(11): 4357-4368, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29532474

RESUMO

BACKGROUND: Water deficiency affects grain proteome dynamics and storage protein compositions, resulting in changes in gluten viscoelasticity. In this study, the effects of field water deficit on wheat breadmaking quality and grain storage proteins were investigated. RESULTS: Water deficiency produced a shorter grain-filling period, a decrease in grain number, grain weight and grain yield, a reduced starch granule size and increased protein content and glutenin macropolymer contents, resulting in superior dough properties and breadmaking quality. Reverse phase ultra-performance liquid chromatography analysis showed that the total gliadin and glutenin content and the accumulation of individual components were significantly increased by water deficiency. Two-dimensional gel electrophoresis detected 144 individual storage protein spots with significant accumulation changes in developing grains under water deficit. Comparative proteomic analysis revealed that water deficiency resulted in significant upregulation of 12 gliadins, 12 high-molecular-weight glutenin subunits and 46 low-molecular-weight glutenin subunits. Quantitative real-time polymerase chain reaction analysis revealed that the expression of storage protein biosynthesis-related transcription factors Dof and Spa was upregulated by water deficiency. CONCLUSION: The present results illustrated that water deficiency leads to increased accumulation of storage protein components and upregulated expression of Dof and Spa, resulting in an improvement in glutenin strength and breadmaking quality. © 2018 Society of Chemical Industry.


Assuntos
Pão/análise , Triticum/química , Água/análise , Farinha/análise , Manipulação de Alimentos , Armazenamento de Alimentos , Proteínas de Plantas/análise , Viscosidade
9.
Electromagn Biol Med ; 36(1): 1-7, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27355558

RESUMO

The biological effects of electromagnetic pulse (EMP) on the brain have been focused on for years. It was reported that gelatinase played an important role in maintaining brain function through regulating permeability in the blood-brain barrier (BBB). To investigate the effects of EMP on gelatinase of BBB, an in vitro BBB model was established using primary cultured rat brain microvascular endothelial cells (BMVEC), astrocytes and half-contact culture of these cells in a transwell chamber. Cultured supernatant and cells were collected at different time points after exposure to EMP (peak intensity 400 kV/m, rise time 10 ns, pulse width 350 ns, 0.5 pps and 200 pulses). Protein levels of cellular gelatinase MMP-2 and MMP-9, and endogenous inhibitor TIMP-1 and TIMP-2 were detected by Western blot. The activity of gelatinase in culture supernatant was detected by gelatin zymography. It was found that compared with the sham-exposed group, the protein level of MMP-2 was significantly increased at 6 h (p < 0.05), and the protein level of its endogenous inhibitor TIMP-2 did not change after EMP exposure. In addition, the protein levels of MMP-9 and its endogenous inhibitor TIMP-1 did not change after EMP exposure. Gelatin zymography results showed that the activity of MMP-2 in the inner pool and the outer pool of the transwell chamber was significantly increased at 6 h after EMP exposure compared with that of the sham group. These results suggested that EMP exposure could affect the expression and activity of MMP-2 in the BBB model.


Assuntos
Barreira Hematoencefálica/enzimologia , Barreira Hematoencefálica/efeitos da radiação , Fenômenos Eletromagnéticos , Gelatinases/metabolismo , Animais , Barreira Hematoencefálica/metabolismo , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos da radiação , Masculino , Ratos , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Inibidor Tecidual de Metaloproteinase-2/metabolismo
10.
J Sci Food Agric ; 96(11): 3731-40, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26676564

RESUMO

BACKGROUND: Metabolites in wheat grains greatly influence nutritional values. Wheat provides proteins, minerals, B-group vitamins and dietary fiber to humans. These metabolites are important to human health. However, the metabolome of the grain during the development of bread wheat has not been studied so far. In this work the first dynamic metabolome of the developing grain of the elite Chinese bread wheat cultivar Zhongmai 175 was analyzed, using non-targeted gas chromatography/mass spectrometry (GC/MS) for metabolite profiling. RESULTS: In total, 74 metabolites were identified over the grain developmental stages. Metabolite-metabolite correlation analysis revealed that the metabolism of amino acids, carbohydrates, organic acids, amines and lipids was interrelated. An integrated metabolic map revealed a distinct regulatory profile. The results provide information that can be used by metabolic engineers and molecular breeders to improve wheat grain quality. CONCLUSION: The present metabolome approach identified dynamic changes in metabolite levels, and correlations among such levels, in developing seeds. The comprehensive metabolic map may be useful when breeding programs seek to improve grain quality. The work highlights the utility of GC/MS-based metabolomics, in conjunction with univariate and multivariate data analysis, when it is sought to understand metabolic changes in developing seeds. © 2015 Society of Chemical Industry.


Assuntos
Grão Comestível/metabolismo , Metaboloma , Valor Nutritivo , Organogênese Vegetal/fisiologia , Triticum/metabolismo , Pão , China , Grão Comestível/crescimento & desenvolvimento , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Metabolômica , Triticum/crescimento & desenvolvimento
11.
Heliyon ; 10(8): e29428, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38638966

RESUMO

Activated astrocytes are a primary source of inflammatory factors following traumatic optic neuropathy (TON). Accumulation of inflammatory factors in this context leads to increased axonal damage and loss of retinal ganglion cells (RGCs). Therefore, in the present study, we explored the role of the astrocyte G protein-coupled estrogen receptor (GPER) in regulating inflammatory factors following optic nerve crush (ONC), and analyzed its potential regulatory mechanisms. Overall, our results showed that GPER was abundantly expressed in the optic nerve, and co-localized with glial fibrillary acidic proteins (GFAP). Exogenous administration of G-1 led to a significant reduction in astrocyte activation and expression of inflammation-related factors (including IL-1ß, TNF-α, NFκB, and p-NFκB). Additionally, it dramatically increased the survival of RGCs. In contrast, astrocytes were activated to a greater extent by exogenous G15 administration; however, RGCs survival was significantly reduced. In vitro, GPER activation significantly reduced astrocyte activation and the release of inflammation-related factors. In conclusion, activation of astrocyte GPER significantly reduced ONC inflammation levels, and should be explored as a potential target pathway for protecting the optic nerve and RGCs after TON.

12.
Sci Total Environ ; 941: 173680, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38844212

RESUMO

Microorganisms play a critical role in the biogeochemical cycling of selenium in natural ecosystems, particularly in reducing selenite (Se(IV)) to element selenium (Se(0)) which reduces its mobility and bioavailability. However, Se(IV)-reducing bacteria and their reducing characteristics in estuarine sediments remain inadequately understood. In this study, the reduction of Se(IV) was confirmed to be microbially driven through the cultivation of a mixture of estuarine sediment and Se(IV) under aerobic conditions. Community analysis indicates that Bacillus was primarily involved in the reduction of Se(IV). A strain with high salt tolerance (7.5 % NaCl) and Se(IV) resistance (up to 200 mM), Bacillus cereus SD1, was isolated from an estuarine sediment. The reduction of Se(IV) occurred concomitantly with the onset of microbial growth, and reduction capacity increased approximately 5-fold by adjusting the pH. In addition, Se(IV) reduction in Bacillus cereus SD1 was significantly inhibited by sulfite, and the key enzyme activity tests revealed the possible presence of a sulfite reductase-mediated Se(IV) reduction pathway. These research findings provide new insights into the bioreducing characteristics and the biogeochemical cycling of selenium in estuarine environments.


Assuntos
Estuários , Sedimentos Geológicos , Selênio , Sedimentos Geológicos/microbiologia , Sedimentos Geológicos/química , Selênio/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Bacillus cereus/metabolismo , Oxirredução , Bactérias/metabolismo
13.
ChemSusChem ; 16(10): e202202365, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-36737418

RESUMO

The carbonylation of alkynes using CO2 to generate aurones is to date unknown. In this study, a palladium-catalyzed carbonylation of terminal aromatic alkynes and the waste hydrosilane, poly(methylhydrosiloxane) (PMHS), is carried out with 2-iodophenol using CO2 to produce aurones. A variety of terminal alkynes and substituted 2-iodophenols are transformed into aurones in good yields. Preliminary mechanistic studies indicate that silyl formate, generated from CO2 and PMHS, plays a crucial role in the carbonylation reaction.

14.
Invest Ophthalmol Vis Sci ; 64(5): 7, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37145604

RESUMO

Purpose: Microglial clearance of axonal debris is an essential response for management of traumatic optic neuropathy. Inadequate removal of axonal debris leads to increased inflammation and axonal degeneration after traumatic optic neuropathy. The present study investigated the role of CD11b (Itgam) in axonal debris clearance and axonal degeneration. Methods: Western blot and immunofluorescence were used to detect CD11b expression in the mouse optic nerve crush (ONC) model. Bioinformatics analysis predicted the possible role of CD11b. Cholera toxin subunit B (CTB) and zymosan were used to assay phagocytosis by microglia in vivo and in vitro, respectively. CTB was also used to label functionally intact axons after ONC. Results: CD11b is abundantly expressed after ONC and participates in phagocytosis. Microglia from Itgam-/- mice exhibited more significant phagocytosis of axonal debris than wild-type microglia. In vitro experiments confirmed that the CD11b gene defect in M2 microglia leads to increased insulin-like growth factor-1 secretion and thus promotes phagocytosis. Lastly, following ONC, Itgam-/- mice exhibited elevated expression of neurofilament heavy peptide and Tuj1, along with more intact CTB-labeled axons when compared with wild-type mice. Moreover, the inhibition of insulin-like growth factor-1 decreased CTB labeling in Itgam-/- mice after injury. Conclusions: CD11b limits microglial phagocytosis of axonal debris in traumatic optic neuropathy, as demonstrated by increased phagocytosis with CD11b knockout. The inhibition of CD11b activity may be a novel approach to promote central nerve repair.


Assuntos
Microglia , Traumatismos do Nervo Óptico , Camundongos , Animais , Microglia/metabolismo , Traumatismos do Nervo Óptico/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Camundongos Knockout , Axônios/metabolismo , Compressão Nervosa , Camundongos Endogâmicos C57BL
15.
FEMS Microbiol Ecol ; 99(11)2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37766397

RESUMO

Large amounts of carbon sequestered in permafrost on the Tibetan Plateau (TP) are becoming vulnerable to microbial decomposition in a warming world. However, knowledge about how the responsible microbial community responds to warming-induced permafrost thaw on the TP is still limited. This study aimed to conduct a comprehensive comparison of the microbial communities and their functional potential in the active layer of thawing permafrost on the TP. We found that the microbial communities were diverse and varied across soil profiles. The microbial diversity declined and the relative abundance of Chloroflexi, Bacteroidetes, Euryarchaeota, and Bathyarchaeota significantly increased with permafrost thawing. Moreover, warming reduced the similarity and stability of active layer microbial communities. The high-throughput qPCR results showed that the abundance of functional genes involved in liable carbon degradation and methanogenesis increased with permafrost thawing. Notably, the significantly increased mcrA gene abundance and the higher methanogens to methanotrophs ratio implied enhanced methanogenic activities during permafrost thawing. Overall, the composition and functional potentials of the active layer microbial community in the Tibetan permafrost region are susceptible to warming. These changes in the responsible microbial community may accelerate carbon degradation, particularly in the methane releases from alpine permafrost ecosystems on the TP.


Assuntos
Euryarchaeota , Microbiota , Pergelissolo , Pergelissolo/química , Tibet , Microbiota/genética , Archaea/genética , Archaea/metabolismo , Solo/química , Euryarchaeota/genética , Euryarchaeota/metabolismo , Carbono/metabolismo
16.
Environ Technol ; 43(24): 3706-3718, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34018903

RESUMO

The effect of pH regulation on schwertmannite bio-synthesis and its As removal ability were investigated in this study. The total Fe precipitation efficiency in a conventional schwertmannite bio-synthesis system (CK) reached 26.5%, with a mineral weight of 5.21 g/L and a mineral specific surface area of 3.18 m2/g. The total Fe precipitation efficiency increased to 88.4-95.8%, the mineral weight increased to 17.10-18.62 g/L, and the specific surface area increased to 3.61-90.67 m2/g of five different treatments in which the system pH was continually adjusted to 2.50, 2.70, 2.90, 3.10, and 3.30 every 3 h, respectively. The very small amounts of schwertmannite were transformed to goethite when the system pH was periodically adjusted to 2.90, 3.10 and 3.30. The increased specific surface area of bio-schwertmannite was due to the contribution of mesopores, with most pores having a diameter of 2-20 nm. For actual As-containing groundwater (27.4 µg/L), the As removal rate was 52.9% for bio-schwertmannite collected from the CK system. However, the removal rate of As increased to 92.7-97.8% for minerals which were collected after five adjusted pH treatments. The outcomes of this study provide a fresh insight into the bio-synthesis regulation of schwertmannite, and have great significance for the treatment of As-containing groundwater.


Assuntos
Arsênio , Compostos de Ferro , Acidithiobacillus , Concentração de Íons de Hidrogênio , Minerais , Oxirredução
17.
Zhonghua Yi Xue Za Zhi ; 90(45): 3231-4, 2010 Dec 07.
Artigo em Zh | MEDLINE | ID: mdl-21223775

RESUMO

OBJECTIVE: To investigate the exposure effect of electromagnetic pulse (EMP) on the structure and secretion of pituitary gland in rats. METHODS: Forty-eight male SD rats were randomly divided into eight groups. Four groups were subject to the EMP exposure of 200 kV/m and the others received a sham exposure. At different time points (12, 24, 48 & 96 h) post-exposure, the pathological changes of pituitary gland were observed by light and transmission electron microscope. And the serum levels of prolactin (PRL), growth hormone (GH), adrenocorticotropic hormone (ACTH), thyroid stimulating hormone (TSH) and luteinizing hormone (LH) were measured dynamically by radioimmunoassay. RESULTS: At 12 h post-exposure, swollen mitochondria with cristae loss, dilatation of Golgi complex and diffusive lysosomes were found in endocrine cells of pituitary gland. The above changes became gradually worse. Mitochondrial vacuolization, the formation of myelin figures, distinct dilatation of endoplasmic reticulum, the occurrence of numerous secondary lysosomes and the clustering of heterochromatin under the nuclear membranes could be observed at 48 h. These lesions were alleviated to some degree at 96 h. The serum levels of PRL and ACTH both increased significantly at 12 h (P < 0.01, P < 0.05) and returned to normal at 24 h. The level of GH decreased significantly at 12 h and then returned gradually to normal at 48 h. The level of TSH decreased at 12 h and reached the lowest point at 24 h, then returned to normal at 96 h. LH increased significantly from 24 h to 96 h. CONCLUSION: The EMP exposure of 200 kV/m may induce the changes of the structure and secretion of pituitary gland in rats.


Assuntos
Campos Eletromagnéticos , Hipófise/metabolismo , Hipófise/ultraestrutura , Animais , Masculino , Hipófise/efeitos da radiação , Ratos , Ratos Sprague-Dawley
18.
Interdiscip Sci ; 12(2): 226-236, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32297074

RESUMO

Hepatocellular carcinoma (HCC) is a common cancer of high mortality, mainly due to the difficulty in diagnosis during its clinical stage. Here we aim to find the gene biomarkers, which are of important significance for diagnosis and treatment. In this work, 3682 differentially expressed genes on HCC were firstly differentiated based on the Cancer Genome Atlas database (TCGA). Co-expression modules of these differentially expressed genes were then constructed based on the weighted correlation network algorithm. The correlation coefficient between the co-expression module and clinical data from the Broad GDAC Firehose was thereafter derived. Finally, the interactive network of genes was then constructed. Then, the hub genes were used to implement enrichment analysis and pathway analysis in the Database for Annotation, Visualization and Integrated Discovery (DAVID) database. Results revealed that the abnormally expressed genes in the module played an important role in the biological process including cell division, sister chromatid cohesion, DNA repair, and G1/S transition of mitotic cell cycle. Meanwhile, these genes also enriched in a few crucial pathways related to Cell cycle, Oocyte meiosis, and p53 signaling. Via investigating the closeness centrality of the interactive network, eight gene biomarkers including the CKAP2, TPX2, CDCA8, KIFC1, MELK, SGO1, RACGAP1, and KIAA1524 gene were discovered, whose functions had been indeed revealed to be correlated with HCC. This study, therefore, suggests that the abnormal expression of those eight genes may be taken as gene biomarkers of HCC.


Assuntos
Carcinoma Hepatocelular/genética , Expressão Gênica , Genes Neoplásicos , Neoplasias Hepáticas/genética , Mapas de Interação de Proteínas , Autoantígenos/genética , Autoantígenos/metabolismo , Biomarcadores Tumorais , Carcinoma Hepatocelular/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Bases de Dados Factuais , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Perfilação da Expressão Gênica , Marcadores Genéticos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Cinesinas/genética , Cinesinas/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo
19.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(2): 134-137, 2020 Mar.
Artigo em Zh | MEDLINE | ID: mdl-32744006

RESUMO

Objective: To observe the effects of repeated horizontal -Gx acceleration exposure on cardiac structure in New Zealand rabbits. Methods: Twenty New Zealand rabbits were divided into 2 groups (n=10): control group and -Gx acceleration exposure group. The rabbits in -Gx acceleration exposure group were exposed to -3. 6 Gx with 2 s, at intervals of 5 min, repeated 20 times daily, with a total of 30 d; the control group didn't undergo the acceleration stress. After the last -Gx acceleration exposure, the animals were killed by intravenous injection of air, and two small pieces of myocardium were immediately dissected from the left ventricles for structure examination using optical microscope and transmission electron microscope. Results: There was no significant difference in the myocardial cell morphology and arrangement observed under the optical microscope between the -Gx acceleration exposure group and the control group; the myocardial fibers arranged in disorder, myocardial cell edema, nuclear membrane expansion, vascular endothelial basement membrane separation were observed in the -Gx acceleration exposure group under transmission electron microscope, compared with the control group. Conclusion: -Gx acceleration exposure can lead to ultrastructural damage in rabbit cardiac myocytes. It suggested that the more attention should be paid to the effect and protection of long-term horizontal -Gx acceleration exposure on the cardiac function of carrier fighter pilots.


Assuntos
Aceleração , Miocárdio/patologia , Miócitos Cardíacos/patologia , Animais , Coelhos
20.
Artigo em Zh | MEDLINE | ID: mdl-20137299

RESUMO

OBJECTIVE: To study the effect of electromagnetic pulse (EMP) on the permeability of blood-brain barrier, tight junction (TJ)-associated protein expression and localization in rats. METHODS: 66 male SD rats, weighing (200 approximately 250) g, were sham or whole-body exposed to EMP at 200 kV/m for 200 pulses. The repetition rate was 1 Hz. The permeability of the blood-brain barrier in rats was assessed by albumin immunohistochemistry. The expression of typical tight junction protein ZO-1 and occludin in both cerebral cortex homogenate and cerebral cortex microvessel homogenate was analyzed by the Western blotting and the distribution of ZO-1 and occludin was examined by immunofluorescence microscopy. RESULTS: In the sham exposure rats, no brain capillaries showed albumin leakage, at 0.5 h after 200 kV/m EMP exposure for 200 pulses; a few brain capillaries with extravasated serum albumin was found, with the time extended, the number of brain capillaries with extravasated serum albumin increased, and reached the peak at 3 h, then began to recover at 6 h. In addition, no change in the distribution of the occludin was found after EMP exposure. Total occludin expression had no significant change compared with the control. However, the expression level of ZO-1 significantly decreased at 1 h and 3 h after EMP exposure in both cerebral cortex homogenate and cerebral cortex microvessel homogenate. Furthermore, immunofluorescence studies also showed alterations in ZO-1 protein localization in cerebral cortex microvessel. CONCLUSION: The EMP exposure (200 kV/m, 200 pulses) could increase blood-brain barrier permeability in rat, and this change is associated with specific alterations in tight junction protein ZO-1.


Assuntos
Barreira Hematoencefálica/efeitos da radiação , Permeabilidade Capilar/efeitos da radiação , Campos Eletromagnéticos/efeitos adversos , Proteínas de Membrana/metabolismo , Fosfoproteínas/metabolismo , Animais , Encéfalo/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Proteína da Zônula de Oclusão-1
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA