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1.
Plant Cell ; 36(1): 112-135, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37770034

RESUMO

Reactive oxygen species (ROS) play an essential role in plant growth and responses to environmental stresses. Plant cells sense and transduce ROS signaling directly via hydrogen peroxide (H2O2)-mediated posttranslational modifications (PTMs) on protein cysteine residues. Here, we show that the H2O2-mediated cysteine oxidation of NAC WITH TRANS-MEMBRANE MOTIF1-LIKE 1 (GmNTL1) in soybean (Glycine max) during salt stress promotes its release from the endoplasmic reticulum (ER) membrane and translocation to the nucleus. We further show that an oxidative posttranslational modification on GmNTL1 residue Cys-247 steers downstream amplification of ROS production by binding to and activating the promoters of RESPIRATORY BURST OXIDASE HOMOLOG B (GmRbohB) genes, thereby creating a feed-forward loop to fine-tune GmNTL1 activity. In addition, oxidation of GmNTL1 Cys-247 directly promotes the expression of CATION H+ EXCHANGER 1 (GmCHX1)/SALT TOLERANCE-ASSOCIATED GENE ON CHROMOSOME 3 (GmSALT3) and Na+/H+ Antiporter 1 (GmNHX1). Accordingly, transgenic overexpression of GmNTL1 in soybean increases the H2O2 levels and K+/Na+ ratio in the cell, promotes salt tolerance, and increases yield under salt stress, while an RNA interference-mediated knockdown of GmNTL1 elicits the opposite effects. Our results reveal that the salt-induced oxidation of GmNTL1 promotes its relocation and transcriptional activity through an H2O2-mediated posttranslational modification on cysteine that improves resilience of soybean against salt stress.


Assuntos
Glycine max , Tolerância ao Sal , Glycine max/genética , Tolerância ao Sal/genética , Peróxido de Hidrogênio/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Cisteína/metabolismo , Estresse Fisiológico/genética , Plantas Geneticamente Modificadas/metabolismo , Regulação da Expressão Gênica de Plantas
2.
Exp Eye Res ; 243: 109907, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38649019

RESUMO

Sleep loss is common in modern society and is increasingly associated with eye diseases. However, the precise effects of sleep loss on retinal structure and function, particularly on the retinal circadian system, remain largely unexplored. This study investigates these effects using a chronic sleep deprivation (CSD) model in mice. Our investigation reveals that CSD significantly alters the retinal circadian transcriptome, leading to remarkable changes in the temporal patterns of enriched pathways. This perturbation extends to metabolic and immune-related transcriptomes, coupled with an accumulation of reactive oxygen species in the retina. Notably, CSD rhythmically affects the thickness of the ganglion cell complex, along with diurnal shifts in microglial migration and morphology within the retina. Most critically, we observe a marked decrease in both scotopic and photopic retinal function under CSD conditions. These findings underscore the broad impact of sleep deprivation on retinal health, highlighting its role in altering circadian gene expression, metabolism, immune response, and structural integrity. Our study provides new insights into the broader impact of sleep loss on retinal health.


Assuntos
Ritmo Circadiano , Camundongos Endogâmicos C57BL , Retina , Privação do Sono , Transcriptoma , Animais , Privação do Sono/fisiopatologia , Privação do Sono/metabolismo , Privação do Sono/genética , Camundongos , Ritmo Circadiano/fisiologia , Masculino , Retina/metabolismo , Retina/fisiopatologia , Modelos Animais de Doenças , Células Ganglionares da Retina/patologia , Células Ganglionares da Retina/metabolismo , Eletrorretinografia , Regulação da Expressão Gênica , Doença Crônica
3.
Exp Eye Res ; 246: 110008, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39025460

RESUMO

This study aims to explore the effects of long-term high fructose intake (LHFI) on the structure, functionality, and physiological homeostasis of mouse extra-orbital lacrimal glands (ELGs), a critical component of ocular health. Our findings reveal significant reprogramming of the circadian transcriptome in ELGs following LHFI, alongside the activation of specific inflammatory pathways, as well as metabolic and neural pathways. Notably, LHFI resulted in increased inflammatory infiltration, enhanced lipid deposition, and reduced nerve fiber density in ELGs compared to controls. Functional assessments indicated a marked reduction in lacrimal secretion following cholinergic stimulation in LHFI-treated mice, suggesting impaired gland function. Overall, our results suggest that LHFI disrupts lacrimal gland homeostasis, potentially leading to dry eye disease by altering its structure and secretory function. These insights underscore the profound impact of dietary choices on ocular health and highlight the need for strategies to mitigate these risks.


Assuntos
Ritmo Circadiano , Frutose , Homeostase , Aparelho Lacrimal , Camundongos Endogâmicos C57BL , Transcriptoma , Animais , Aparelho Lacrimal/metabolismo , Aparelho Lacrimal/efeitos dos fármacos , Camundongos , Ritmo Circadiano/fisiologia , Masculino , Lágrimas/metabolismo , Síndromes do Olho Seco/metabolismo , Síndromes do Olho Seco/genética , Modelos Animais de Doenças , Feminino
4.
Biotechnol Bioeng ; 121(2): 551-565, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37921467

RESUMO

Clostridium butyricum is a probiotic that forms anaerobic spores and plays a crucial role in regulating gut microbiota. However, the total viable cell count and spore yield of C. butyricum in industrial production are comparatively low. To this end, we investigated the metabolic characteristics of the strain and proposed three distinct pH regulation strategies for enhancing spore production. In addition, precise measurement of fermentation parameters such as substrate concentration, total viable cell count, and spore concentration is crucial for successful industrial probiotics production. Nevertheless, online measurement of these intricate parameters in the fermentation of C. butyricum poses a considerable challenge owing to the complex, nonlinear, multivariate, and strongly coupled characteristics of the production process. Therefore, we analyzed the capacitance and conductivity acquired from a viable cell sensor as the core parameters for the fermentation process. Subsequently, a robust soft sensor was developed using a seven-input back-propagation neural network model with input variables of fermentation time, capacitance, conductivity, pH, initial total sugar concentration, ammonium ion concentration, and calcium ion concentration. The model enables the online monitoring of total viable biomass count, substrate concentrations, and spore yield, and can be extended to similar fermentation processes with pH changes as a characteristic feature.


Assuntos
Clostridium butyricum , Clostridium butyricum/metabolismo , Esporos Bacterianos , Fermentação , Redes Neurais de Computação , Concentração de Íons de Hidrogênio
5.
Langmuir ; 40(40): 21067-21076, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39329510

RESUMO

Understanding the interlayer interaction between 2D layered structures is critical for the construction of various micro- and nanoscale functional devices. However, both the normal and the tangential interlayer interactions between 2D layered materials have rarely been studied simultaneously. In this work, an immersion and lift-up method is proposed to wrap a layer of graphene flakes onto a plasma-pretreated atomic force microscopy (AFM) nanoprobe for the measurements of interaction forces by AFM. The normal interactions (adhesion force and adhesion energy) and tangential interactions (friction force) between two different probes (Pt-coated probe and graphene-wrapped probe) and two different 2D graphene materials [graphene and graphene oxide (GO)] were systematically measured, respectively. The adhesion energies of Pt-GO, Pt-graphene, graphene-GO, and graphene-graphene were measured to be 0.72 ± 0.05, 0.41 ± 0.03, 0.19 ± 0.02, and 0.10 ± 0.02 J m-2, respectively. The graphene-graphene contact pair showed the lowest adhesion force (5.57 ± 1.03 nN) and adhesion energy (0.10 ± 0.02 J m-2), which was attributed to the strong covalent bonds and charge density distribution. The friction coefficients of Pt-GO, graphene-GO, Pt-graphene, and graphene-graphene were determined to be 0.38, 0.14, 0.054, and 0.013. The graphene-graphene tribo-pair exhibited a superlow friction state for a long time, which was attributed to incommensurate contact and weak van der Waals interactions. These findings provide a technical route to reveal the interlayer interactions of various 2D layered materials, which can be widely applied in microelectromechanical systems.

6.
BMC Infect Dis ; 24(1): 116, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38254025

RESUMO

OBJECTIVE: This study aimed to explore the characteristics of carbapenem-resistant Enterobacterales (CRE) patients in the intensive care unit (ICU) in different regions of Henan Province to provide evidence for the targeted prevention and treatment of CRE. METHODS: This was a cross-sectional study. CRE screening was conducted in the ICUs of 78 hospitals in Henan Province, China, on March 10, 2021. The patients were divided into provincial capital hospitals and nonprovincial capital hospitals for comparative analysis. RESULTS: This study involved 1009 patients in total, of whom 241 were CRE-positive patients, 92 were in the provincial capital hospital and 149 were in the nonprovincial capital hospital. Provincial capital hospitals had a higher rate of CRE positivity, and there was a significant difference in the rate of CRE positivity between the two groups. The body temperature; immunosuppressed state; transfer from the ICU to other hospitals; and use of enemas, arterial catheters, carbapenems, or tigecycline at the provincial capital hospital were greater than those at the nonprovincial capital hospital (P < 0.05). However, there was no significant difference in the distribution of carbapenemase strains or enzymes between the two groups. CONCLUSIONS: The detection rate of CRE was significantly greater in provincial capital hospitals than in nonprovincial capital hospitals. The source of the patients, invasive procedures, and use of advanced antibiotics may account for the differences. Carbapenem-resistant Klebsiella pneumoniae (CR-KPN) was the most prevalent strain. Klebsiella pneumoniae carbapenemase (KPC) was the predominant carbapenemase enzyme. The distributions of carbapenemase strains and enzymes were similar in different regions.


Assuntos
Antibacterianos , Temperatura Corporal , Humanos , Estudos Transversais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Cânula , Carbapenêmicos/farmacologia , Klebsiella pneumoniae
7.
J Integr Plant Biol ; 66(8): 1620-1638, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38860597

RESUMO

The development of flowers in soybean (Glycine max) is essential for determining the yield potential of the plant. Gene silencing pathways are involved in modulating flower development, but their full elucidation is still incomplete. Here, we conducted a forward genetic screen and identified an abnormal flower mutant, deformed floral bud1-1 (Gmdfb1-1), in soybean. We mapped and identified the causal gene, which encodes a member of the armadillo (ARM)-repeat superfamily. Using small RNA sequencing (sRNA-seq), we found an abnormal accumulation of small interfering RNAs (siRNAs) and microRNA (miRNAs) in the Gmdfb1 mutants. We further demonstrated that GmDFB1 interacts with the RNA exosome cofactor SUPER KILLER7 (GmSKI7). Additionally, GmDFB1 interacts with the PIWI domain of ARGONAUTE 1 (GmAGO1) to inhibit the cleavage efficiency on the target genes of sRNAs. The enhanced gene silencing mediated by siRNA and miRNA in the Gmdfb1 mutants leads to the downregulation of their target genes associated with flower development. This study revealed the crucial role of GmDFB1 in regulating floral organ identity in soybean probably by participating in two distinct gene silencing pathways.


Assuntos
Flores , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Glycine max , MicroRNAs , Proteínas de Plantas , RNA Interferente Pequeno , Glycine max/genética , Glycine max/crescimento & desenvolvimento , Glycine max/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/genética , Mutação/genética
8.
Langmuir ; 39(45): 16151-16162, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37910769

RESUMO

This study presented a novel modification method for fine SiC powder by using sodium lignosulfonate as a dispersant. The adsorption behavior of sodium lignosulfonate on the SiC/water interface and its effect on the performance of a fine SiC slurry were systematically investigated. The adsorption results showed that sodium lignosulfonate formed monolayer adsorption on the surface of fine SiC and that the saturated adsorption capacity was 1.3263 mg/g. The adsorption reached equilibrium within 3 h and was mainly controlled by active sites on the SiC surface. The dispersion, stability, and zeta potential of modified SiC powder were improved after sodium lignosulfonate adsorption. The zeta potential of modified SiC reached a minimum value of -44.8 mV at pH 12. Modified SiC suspensions had great stability in a wider pH range of 6-12. Modified SiC slurry with 54 vol % solid loading had a low viscosity of 173 mPa·s at pH 10. Subsequently, coarse SiC powder was added for slip casting. A mixed slurry with high solid loading (69 vol %) and low viscosity (583 mPa·s) was prepared using modified SiC and coarse SiC powders at a mass ratio of 2:3. Finally, recrystallized SiC green body with high density (2.6492 g/cm3) was obtained.

9.
J Microsc ; 291(3): 229-236, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37358710

RESUMO

Many diseases are related to changes in the biomechanical properties of cells; their study can provide a theoretical basis for drug screening and can explain the internal working of living cells. In this study, the biomechanical properties of nephrocytes (VERO cells), hepatocytes (HL-7702 cells), and hepatoma cells (SMCC-7721 cells) in culture were detected by atomic force microscopy (AFM) to analyse the side effects of colchicine at different concentrations (0.1 µg/mL (A) and 0.2 µg/mL (B)) at the nanoscale for 2, 4 and 6 h. Compared with the corresponding control cells, the damage to the treated cells increased in a dose-dependent manner. Among normal cells, the injury of nephrocytes (VERO cells) was markedly worse than that of hepatocytes (HL-7702 cells) in both colchicine solutions A and B. Based on the analyses of biomechanical properties, the colchicine solution reduced the rate of division and inhibited metastasis of SMCC-7721 cells. By comparing these two concentrations, we found that the anticancer effect of colchicine solution A was greater than that of solution B. Studying the mechanical properties of biological cells can help understand the mechanism of drug action at the molecular level and provide a theoretical basis for preventing the emergence and diagnosis of diseases at the nanoscale.


Assuntos
Colchicina , Hepatócitos , Animais , Chlorocebus aethiops , Colchicina/toxicidade , Fenômenos Biomecânicos , Células Vero , Microscopia de Força Atômica
10.
Environ Sci Technol ; 57(23): 8467-8475, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37256786

RESUMO

Residential emissions significantly contribute to air pollution. To address this issue, a clean heating campaign was implemented to replace coal with electricity or natural gas among 13.9 million rural households in northern China. Despite great success, the cost-benefits and environmental equity of this campaign have never been fully investigated. Here, we modeled the environmental and health benefits, as well as the total costs of the campaign, and analyzed the inequality and inequity. We found that even though the campaign decreased only 1.1% of the total energy consumption, PM2.5 emissions and PM2.5 exposure experienced 20% and 36% reduction, respectively, revealing the amplification effects along the causal pathway. Furthermore, the number of premature deaths attributable to residential emissions reduced by 32%, suggesting that the campaign was highly beneficial. Governments and residents shared the cost of 2,520 RMB/household. However, the benefits and the costs were unevenly distributed, as the residents in mountainous areas were not only less benefited from the campaign but also paid more because of the higher costs, resulting in a notably lower cost-effectiveness. Moreover, villages in less developed areas tended to choose natural gas with a lower initial investment but a higher total cost (2,720 RMB/household) over electricity (2,190 RMB/household). With targeted investment and subsidies in less developed areas and the promotion of electricity and other less expensive alternatives, the multidevelopment goals of improved air quality, reduced health impacts, and reduced inequity in future clean heating interventions could be achieved.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Humanos , Análise Custo-Benefício , Material Particulado/análise , Calefação , Gás Natural , Poluição do Ar/análise , China , Poluentes Atmosféricos/análise
11.
J Immunol ; 206(10): 2412-2419, 2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-33911005

RESUMO

Sepsis induces significant immune dysregulation characterized by lymphocyte apoptosis and alterations in the cytokine milieu. Because cancer patients exhibit a 10-fold greater risk of developing sepsis compared with the general population, we aimed to understand how pre-existing malignancy alters sepsis-induced immune dysregulation. To address this question, we assessed the impact of tumor-specific CD8+ T cells on the immune response in a mouse model of cecal ligation and puncture (CLP)-induced sepsis. Tumor-bearing animals containing Thy1.1+ tumor-specific CD8+ T cells were subjected to CLP, and groups of animals received anti-Thy1.1 mAb to deplete tumor-specific CD8+ T cells or isotype control. Results indicated that depleting tumor-specific T cells significantly improved mortality from sepsis. The presence of tumor-specific CD8+ T cells resulted in increased expression of the 2B4 coinhibitory receptor and increased apoptosis of endogenous CD8+ T cells. Moreover, tumor-specific T cells were not reduced in number in the tumors during sepsis but did exhibit impaired IFN-γ production in the tumor, tumor draining lymph node, and spleen 24 h after CLP. Our research provides novel insight into the mechanisms by which pre-existing malignancy contributes to increased mortality during sepsis.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Imunidade , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/imunologia , Melanoma Experimental/complicações , Melanoma Experimental/imunologia , Sepse/complicações , Sepse/imunologia , Neoplasias Cutâneas/complicações , Neoplasias Cutâneas/imunologia , Animais , Apoptose/imunologia , Linhagem Celular Tumoral , Citocinas/sangue , Interferon gama/metabolismo , Neoplasias Pulmonares/sangue , Linfonodos/imunologia , Masculino , Melanoma Experimental/sangue , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo , Sepse/sangue , Sepse/mortalidade , Neoplasias Cutâneas/sangue , Baço/imunologia , Antígenos Thy-1/genética
12.
Nano Lett ; 22(2): 740-750, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-35019663

RESUMO

Flexible transparent electrodes demand high transparency, low sheet resistance, as well as excellent mechanical flexibility simultaneously, however they still remain to be a great challenge due to"trade-off" effect. Herein, inspired by a hollow interconnected leaf vein, we developed robust transparent conductive mesh with biomimetic interwoven structure via hierarchically self-assembles silver nanowires interwoven metal carbide/nitride (MXene) sheets along directional microfibers. Strong interfacial interactions between plant fibers and conductive units facilitate hierarchically interwoven conductive mesh constructed orderly on flexible and lightweight veins while maintaining high transparency, effectively avoiding the trade-off effect between optoelectronic properties. The flexible transparent electrodes exhibit sheet resistance of 0.5 Ω sq-1 and transparency of 81.6%, with a remarkably high figure of merit of 3523. In addition, invisible camouflage sensors are further successfully developed as a proof of concept that could monitor human body motion signals in an imperceptible state. The flexible transparent conductive mesh holds great potential in high-performance wearable optoelectronics and camouflage electronics.


Assuntos
Nanofios , Biomimética , Eletrodos , Eletrônica , Humanos , Nanofios/química , Prata/química
13.
Plant Cell ; 31(9): 2107-2130, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31227558

RESUMO

Abscisic acid (ABA) and reactive oxygen species (ROS) act as key signaling molecules in the plant response to salt stress; however, how these signals are transduced and amplified remains unclear. Here, a soybean (Glycine max) salinity-induced NAM/ATAF1/2/CUC2 (NAC) transcription factor encoded by SALT INDUCED NAC1 (GmSIN1) was shown to be a key component of this process. Overexpression of GmSIN1 in soybean promoted root growth and salt tolerance and increased yield under salt stress; RNA interference-mediated knockdown of GmSIN1 had the opposite effect. The rapid induction of GmSIN1 in response to salinity required ABA and ROS, and the effect of GmSIN1 on root elongation and salt tolerance was achieved by boosting cellular ABA and ROS contents. GmSIN1 upregulated 9-cis-epoxycarotenoid dioxygenase coding genes in soybean (GmNCED3s, associated with ABA synthesis) and Respiratory burst oxidase homolog B genes in soybean (GmRbohBs, associated with ROS generation) by binding to their promoters at a site that has not been described to date. Together, GmSIN1, GmNCED3s, and GmRbohBs constitute a positive feed-forward system that enables the rapid accumulation of ABA and ROS, effectively amplifying the initial salt stress signal. These findings suggest that the combined modulation of ABA and ROS contents enhances soybean salt tolerance.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Dioxigenases/metabolismo , Glycine max/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Ribonuclease III/metabolismo , Estresse Salino/fisiologia , Ácido Abscísico/metabolismo , Proteínas de Arabidopsis , Proteínas de Ciclo Celular/genética , Dioxigenases/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Espécies Reativas de Oxigênio/metabolismo , Ribonuclease III/genética , Salinidade , Estresse Salino/genética , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Glycine max/genética , Estresse Fisiológico
14.
Chemistry ; 27(50): 12758-12762, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34181286

RESUMO

Dynamic nuclear polarization (DNP) is a powerful method to enhance the sensitivity of solid-state magnetic nuclear resonance (ssNMR) spectroscopy. However, its biomolecular applications at high magnetic fields (preferably>14 T) have so far been limited by the intrinsically low efficiency of polarizing agents and sample preparation aspects. Herein, we report a new class of trityl-nitroxide biradicals, dubbed SNAPols that combine high DNP efficiency with greatly enhanced hydrophilicity. SNAPol-1, the best compound in the series, shows DNP enhancement factors at 18.8 T of more than 100 in small molecules and globular proteins and also exhibits strong DNP enhancements in membrane proteins and cellular preparations. By integrating optimal sensitivity and high resolution, we expect widespread applications of this new polarizing agent in high-field DNP/ssNMR spectroscopy, especially for complex biomolecules.


Assuntos
Campos Magnéticos , Óxidos de Nitrogênio , Espectroscopia de Ressonância Magnética , Proteínas de Membrana
15.
Nanotechnology ; 33(5)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34284356

RESUMO

The nanoprobe is a powerful tool in scanning probe microscopy (SPM) that is used to explore various fields of nanoscience. However, the tips can wear out very fast due to the low stability of conventional probes, especially after the measurement of high currents or lateral friction, which results in image distortion and test imprecision. Herein, a novel functional nanoprobe is presented using graphene sheets in a high-quality graphene solution wrapped round a plasma-treated conventional Pt-Ir coated nanoprobe, which shows highly stability and resistance to degradation, leading to a significantly increased lifetime. Furthermore, we show that the graphene-wrapped nanoprobes have the advantages of enhanced electrical conductivity and reduced tip-sample friction, compared with Pt-Ir coated nanoprobes. The simplicity and low cost of this method make it valuable to various functional graphene-wrapped nanoprobes and applications.

16.
Nanotechnology ; 33(5)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34134105

RESUMO

Conductive atomic force microscopy (C-AFM) is a powerful tool used in the microelectronics analysis by applying a certain bias voltage between the conducting probe and the sample and obtaining the electrical information of sample. In this work, the surface morphological information and current images of the lambda DNA (λDNA) molecules with different distributions were obtained by C-AFM. The 1 and 10 ngµl-1DNA solutions were dripped onto mica sheets for making randomly distributed DNA and DNA network samples, and another 1 ngµl-1DNA sample was placed in a DC electric field with a voltage of 2 V before being dried for stretching the DNA sample. The results show that the current flowing through DNA networks was significantly higher than the stretched and random distribution of DNA in the experiment. TheI-Vcurve of DNA networks was obtained by changing the bias voltage of C-AFM from -9 to 9 V. The currents flowing through stretched DNA at different pH values were studied. When the pH was 7, the current was the smallest, and the current was gradually increased as the solution became acidic or alkaline.

17.
Environ Sci Technol ; 55(15): 10300-10309, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34296598

RESUMO

Atmospheric black carbon (BC) concentrations are governed by both emissions and meteorological conditions. Distinguishing these effects enables quantification of the effectiveness of emission mitigation actions by excluding meteorological effects. Here, we develop reduced-form models in both direct (RFDMs) and inverse (RFIMs) modes to estimate ambient BC concentrations. The models were developed based on outputs from multiyear simulations under three conditional scenarios with realistic or fixed emissions and meteorological conditions. We established a set of probabilistic functions (PFs) to quantify the meteorological influences. A significant two-way linear relationship between multiyear annual emissions and mean ambient BC concentrations was revealed at the grid cell scale. The correlation between them was more significant at grid cells with high emission densities. The concentrations and emissions at a given grid cell are also significantly correlated with emissions and concentrations of the surrounding areas, respectively, although to a lesser extent. These dependences are anisotropic depending on the prevailing winds and source regions. The meteorologically induced variation at the monthly scale was significantly higher than that at the annual scale. Of the major meteorological parameters, wind vectors, temperature, and relative humidity were found to most significantly affect variation in ambient BC concentrations.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Meteorologia , Fuligem/análise , Vento
18.
Environ Sci Technol ; 55(12): 7869-7879, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34096723

RESUMO

Accurate estimation of black carbon (BC) emissions is essential for assessing the health and climate impact of this pollutant. Past emission inventories were associated with high uncertainty due to data limitations, and recent information has provided a unique updating opportunity. Moreover, understanding the drivers that cause temporal emission changes is of research value. Here, we update the global BC emission estimates using new data on the activities and emission factors (EFs). The new inventory covers 73 detailed sources at 0.1° × 0.1° spatial resolution and monthly temporal resolution from 1960 to 2017. The estimated annual emissions were 32% higher than the average of several previous inventories, which was primarily due to field-measured EFs for residential stoves and differentiated EFs for motor vehicles. In addition, the updated emissions show an inverse U-shaped temporal trend, which was mainly driven by the interaction between the positive effects of population growth, per capita energy consumption, and vehicle fleet and the negative effects of residential energy switching, stove upgrading, phasing out of beehive coke ovens, and reduced EFs for vehicles and industrial processes. Urbanization caused a significant increase in urban emissions accompanied by a more significant decline in rural emissions.


Assuntos
Poluentes Atmosféricos , Utensílios Domésticos , Poluentes Atmosféricos/análise , Carbono , Monitoramento Ambiental , Veículos Automotores , Fuligem/análise , Emissões de Veículos/análise
19.
Environ Sci Technol ; 55(11): 7316-7326, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33977718

RESUMO

Coal abatement actions for pollution reduction often target total coal consumption. The health impacts of coal uses, however, vary extensively among sectors. Here, we modeled the sectorial contributions of coal uses to emissions, outdoor and indoor PM2.5 (particulate matter with an aerodynamic diameter of less than 2.5 mm) concentrations, exposures, and health outcomes in China from 1970 to 2014. We show that in 2014, residential coal accounted for 2.9% of total energy use but 34% of premature deaths associated with PM2.5 exposure, showing that effects were magnified substantially along the causal path. The number of premature deaths attributed to unit coal consumption in the residential sector was 40 times higher than that in the power and industrial sectors. Emissions of primary PM2.5 were more important than secondary aerosol precursors in terms of health consequences, and indoor exposure accounted for 97% and 91% of total premature deaths attributable to PM2.5 from coal combustion in 1974 and 2014, respectively. Our assessment raises a critical challenge in the switching of residential coal uses to effectively mitigate PM2.5 exposure in the Chinese population.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Carvão Mineral/análise , Material Particulado/análise
20.
FASEB J ; 33(10): 11258-11269, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31306584

RESUMO

The microbiome is increasingly implicated in immune regulation and mortality from sepsis. Mice with identical genetic backgrounds but distinct microbiomes were obtained from different vendors and analyzed following cecal ligation and puncture (CLP). ß diversity of the microbiome measured from feces demonstrated significant differences between The Jackson Laboratory (Jax; Bar Harbor, ME, USA) and Charles River Laboratories (CR; Wilmington, MA, USA) C57/B6 mice. Jax mice had 7-d mortality of 90% following CLP, whereas CR mice had a mortality of 53%. Differences in vendor were associated with altered immunophenotype with increased splenic IFN-γ+CD4+ T cells, effector memory CD4+ T cells, and central memory CD4+ T cells and increased Peyer's patch effector memory CD4+ T cells in septic CR mice. To determine whether differences in the microbiome were responsible for these differences, Jax and CR mice were cohoused for 3 wk, after which they assumed a similar microbiota composition. Cohoused mice had improved survival following CLP compared to Jax mice and had similar survival regardless of their vendor of origin. All differences in immunophenotype between septic Jax and CR mice disappeared following cohousing. These findings suggest that the microbiome plays a crucial role in survival and the host immune response from sepsis and represents a potential target for therapeutic intervention.-Fay, K. T., Klingensmith, N. J., Chen, C.-W., Zhang, W., Sun, Y., Morrow, K. N., Liang, Z., Burd, E. M., Ford, M. L., Coopersmith, C. M. The gut microbiome alters immunophenotype and survival from sepsis.


Assuntos
Microbioma Gastrointestinal/imunologia , Sepse/imunologia , Sepse/microbiologia , Animais , Linfócitos T CD4-Positivos/imunologia , Fezes/microbiologia , Feminino , Interferon gama/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microbiota/imunologia , Nódulos Linfáticos Agregados/imunologia
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