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1.
BMC Geriatr ; 24(1): 466, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38807058

RESUMO

BACKGROUND: With the aging population, the number of individuals with dementia in China is increasing rapidly. This community-based study aimed to investigate the prevalence and risk factors for dementia and mild cognitive impairment (MCI) among older adults in China. METHODS: In this study, 20,070 individuals aged ≥ 65 were recruited between January 1, 2022, and February 1, 2023, from ten communities in Xiamen City, China. We collected data on age, sex, level of education, and medical history, as well as global cognition and functional status. The prevalence of dementia and MCI was examined, and the risk factors for different groups were assessed. RESULTS: The overall prevalence of dementia and MCI was approximately 5.4% (95% confidence interval [CI], 5.1-5.7) and 7.7% (95% CI, 7.4-8.1), respectively. The results also indicated that dementia and MCI share similar risk factors, including older age, female sex, hypertension, and diabetes mellitus. Compared with individuals with no formal education, those with > 6 years of education had an odds ratio for MCI of 1.83 (95% CI, 1.49-2.25). We also found that only 5.5% of the positive participants chose to be referred to the hospital for further diagnosis and treatment during follow-up visits. CONCLUSIONS: This study estimated the prevalence and risk factors for dementia and MCI among individuals aged ≥ 65 years in Southeast China. These findings are crucial for preventing and managing dementia and MCI in China.


Assuntos
Disfunção Cognitiva , Demência , Humanos , Masculino , Feminino , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/diagnóstico , Idoso , China/epidemiologia , Demência/epidemiologia , Demência/diagnóstico , Prevalência , Fatores de Risco , Idoso de 80 Anos ou mais
2.
J Colloid Interface Sci ; 652(Pt A): 653-662, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37543477

RESUMO

Ensuring the consumption rate of noble metals while guaranteeing satisfactory hydrogen evolution reaction (HER) performance at different pH values is imperative to the development of Ru-based catalysts. Herein, we design a Mott-Schottky electrocatalyst (Ru/CeO2) with a built-in electric field (BEF) based on density functional theory (DFT). The Ru/CeO2 achieves the criterion current density of 10 mA cm-2 at overpotentials of 55 mV, 80 mV, and 120 mV in alkaline, acidic and neutral media, respectively. Both theoretical calculations and experimental analysis confirm that the improved HER activity in the Ru/CeO2 catalyst could be due to the successful construction of BEF at the interface between the prepared Ru clusters and CeO2. Under the action of BEF, the electron-deficient Ru atoms can optimize the adsorption energy of H* and H2O and thus promote HER kinetics. Furthermore, the Ru/CeO2 catalyst delivers a power density of approximately 94.5 mW cm-2 in alkaline-acidic Zn-H2O cell applications while maintaining good H2 production stability. In this work, we optimize the electrocatalytic performance of the Ru/CeO2 catalyst through examination of the interfacial BEF electrical charge, which combines hydrogen production with power generation and provides a promising method for sustainable energy conversion.

3.
Adv Sci (Weinh) ; 10(27): e2302518, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37505447

RESUMO

The catalytic performance of metal-organic frameworks (MOFs) in Li-S batteries is significantly hindered by unsuitable pore size, low conductivity, and large steric contact hindrance between the catalytic site and lithium polysulfide (LPSs). Herein, the smallest π-conjugated hexaaminobenzene (HAB) as linker and Ni(II) ions as skeletal node are in situ assembled into high crystallinity Ni-HAB 2D conductive MOFs with dense Ni-N4 units via dsp2 hybridization on the surface of carbon nanotube (CNT), fabricating Ni-HAB@CNT as separator modified layer in Li-S batteries. As-obtained unique π-d conjugated Ni-HAB nanostructure features ordered micropores with suitable pore size (≈8 Å) induced by HAB ligands, which can cooperate with dense Ni-N4 chemisorption sites to effectively suppress the shuttle effect. Meanwhile, the conversion kinetics of LPSs is significantly accelerated owing to the small steric contact hindrance and increased delocalized electron density endued by the planar tetracoordinate structure. Consequently, the Li-S battery with Ni-HAB@CNT modified separator achieves an areal capacity of 6.29 mAh cm-2 at high sulfur loading of 6.5 mg cm-2 under electrolyte/sulfur ratio of 5 µL mg-1 . Moreover, Li-S single-electrode pouch cells with modified separators deliver a high reversible capacity of 791 mAh g-1 after 50 cycles at 0.1 C with electrolyte/sulfur ratio of 6 µL mg-1 .

4.
Plant Cell Environ ; 46(8): 2296-2309, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37294176

RESUMO

While variation in mean annual precipitation (MAP) of the native habitat of a species has been shown to determine the ability of a species to resist a hydraulic decrease during drought, it remains unknown whether these variations in MAP also influence the ability of a species to recover and survive drought. Leaf hydraulic and gas exchange recovery following drought and the underlying mechanisms of these responses in six Caragana species from habitats along a large precipitation gradient were investigated during rehydration in a common garden. The gas exchange of species from arid habitats recovered more rapidly during rehydration after mild, moderate and severe drought stress treatments than species from humid habitats. The recovery of gas exchange was not associated with foliar abscisic acid concentration, but tightly related to the recovery of leaf hydraulic conductance (Kleaf ). The recovery of Kleaf was associated with the loss of Kleaf during dehydration under mild and moderate drought stress, and to leaf xylem embolism formation under severe drought stress. Results pointed to the different ability to recover in gas exchange in six Caragana species post-drought is associated with the MAP of the species in its native habitat.


Assuntos
Caragana , Água , Água/fisiologia , Secas , Folhas de Planta/fisiologia , Xilema/fisiologia
5.
Adv Sci (Weinh) ; 10(22): e2300526, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37246284

RESUMO

Functionalized porous carbons are central to various important applications such as energy storage and conversion. Here, a simple synthetic route to prepare oxygen-rich carbon nitrides (CNOs) decorated with stable Ni and Fe-nanosites is demonstrated. The CNOs are prepared via a salt templating method using ribose and adenine as precursors and CaCl2 ·2H2 O as a template. The formation of supramolecular eutectic complexes between CaCl2 ·2H2 O and ribose at relatively low temperatures facilitates the formation of a homogeneous starting mixture, promotes the condensation of ribose through the dehydrating effect of CaCl2 ·2H2 O to covalent frameworks, and finally generates homogeneous CNOs. As a specific of the recipe, the condensation of the precursors at higher temperatures and the removal of water promotes the recrystallization of CaCl2 (T < Tm = 772 °C), which then acts as a hard porogen. Due to salt catalysis, CNOs with oxygen and nitrogen contents as high as 12 and 20 wt%, respectively, can be obtained, while heteroatom content stayed about unchanged even at higher temperatures of synthesis, pointing to the extraordinarily high stability of the materials. After decorating Ni and Fe-nanosites onto the CNOs, the materials exhibit high activity and stability for electrochemical oxygen evolution reaction with an overpotential of 351 mV.

6.
Pharmacoepidemiol Drug Saf ; 32(2): 107-125, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36224724

RESUMO

BACKGROUND: Some early reports in the medical literature have raised concern about a possible increased risk of pancreatic cancer associated with the use of two broad classes of incretin-based therapies, dipeptidyl peptidase-4 inhibitors, and glucagon-like peptide-1 receptor agonists. This possibility has been somewhat mitigated by the null findings meta-analyses of randomized controlled trials, but the usefulness of their findings was hampered by serious shortcomings of lack of power and representativeness. These shortcomings can typically be addressed by observational studies, but observational studies on the topic have yielded conflicting findings. A systematic review and meta-analysis of observational studies was performed to qualitatively and quantitatively appraise the totality of evidence on the association between the use of incretin-based therapies and the risk of pancreatic cancer in routine clinical practice. METHODS: The PubMed, Web of Science, Embase, and Google Scholar databases were searched. The study quality was appraised using the ROBINS-I tool and based on the presence of pharmacoepidemiology biases. A random-effects model was used to estimate the summary relative risks with corresponding CIs. RESULTS: A total of 14 studies were included. The qualitative assessment revealed that all studies had inadequate follow-up (≤5 years), 12 studies were suspected to suffer from time-lag bias (due to inappropriate choice of comparator group) to varying extent, five studies included prevalent users, five studies did not implement exposure lag period, five studies had a serious risk of bias due to confounding, and one study had a time-window bias. The quantitative assessment showed no indication of an increased risk when all studies were pooled together (RR 1.04, 95% CI 0.87, 1.24) and when the analysis was restricted to the studies with the least bias (RR 0.77, 95% CI 0.51, 1.17). However, the pooled RRs were more frequently higher in the studies with less rigorous design and analysis. Specifically, a tendency toward an increased risk was observed in the studies with (RR 1.34, 95% CI 1.04, 1.72) or possibly with (RR 1.10, 95% CI 0.89, 1.36) time-lag bias, in the studies that did not apply (RR 1.23, 95% CI 0.93, 1.63) or with potentially inadequate exposure lag period of 6 months (RR 1.13, 95% CI 0.66, 1.94), in the studies that inappropriate comparator group of a combination of unspecified (RR 1.49, 95% CI 1.25, 1.78) or non-insulin (RR 1.15, 95% CI 0.93, 1.42) antidiabetic drugs, and in the studies with serious risk of bias due to confounding (RR 1.18, 95% CI 0.56, 2.49). CONCLUSIONS: In summary, the totality of evidence from observational studies does not support the claim that the use of incretin-based therapies is associated with an increased risk of pancreatic cancer in routine clinical practice. The increased risk of pancreatic cancer observed in observational studies reflects bias resulting from suboptimal methodological approaches, which need to be avoided by future studies.


Assuntos
Inibidores da Dipeptidil Peptidase IV , Neoplasias Pancreáticas , Humanos , Incretinas/efeitos adversos , Hipoglicemiantes/efeitos adversos , Neoplasias Pancreáticas/induzido quimicamente , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Neoplasias Pancreáticas
7.
Tree Physiol ; 43(6): 883-892, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-36547259

RESUMO

Clarifying the mechanisms underlying the recovery of gas exchange following drought is the key to providing insights into plant drought adaptation and habitat distribution. However, the mechanisms are still largely unknown. Targeting processes known to inhibit gas exchange during drought recovery, we measured leaf water potential, the leaf hydraulic conductance, stomatal reopening, abscisic acid (ABA) and the ethylene emission rate (EER) following moderate drought stress in seedlings of the globally pervasive woody tree Fraxinus chinensis. We found strong evidence that the slow stomatal reopening after rehydration is regulated by a slow decrease in EER, rather than changes in leaf hydraulics or foliar ABA levels. This was supported by evidence of rapid gas exchange recovery in plants after treatment with the ethylene antagonist 1-methylcyclopropene. These findings provide evidence to rigorously support ethylene as a key factor constraining stomatal reopening from moderate drought directly, thereby potentially opening new windows for understanding species drought adaptation.


Assuntos
Fraxinus , Estômatos de Plantas , Secas , Folhas de Planta , Água , Ácido Abscísico , Etilenos
8.
BMC Med Genomics ; 15(1): 263, 2022 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-36528763

RESUMO

BACKGROUND: Recent studies have demonstrated that long non-coding RNAs (lncRNAs) are involved in regulating tumor cell ferroptosis. However, prognostic signatures based on ferroptosis-related lncRNAs (FRLs) and their relationship to the immune microenvironment have not been comprehensively explored in clear cell renal cell carcinoma (ccRCC). METHODS: In the present study, the expression profiles of ccRCC were acquired from The Cancer Genome Atlas (TCGA) database; 459 patient specimens and 69 adjacent normal tissues were randomly separated into training or validation cohorts at a 7:3 ratio. We identified 7 FRLs that constitute a prognostic signature according to the differential analysis, correlation analysis, univariate regression, and least absolute shrinkage and selection operator (LASSO) Cox analysis. To identify the independence of risk score as a prognostic factor, univariate and multivariate regression analyses were also performed. Furthermore, CIBERSORT was conducted to analyze the immune infiltration of patients in the high-risk and low-risk groups. Subsequently, the differential expression of immune checkpoint and m6A genes was analyzed in the two risk groups. RESULTS: A 7-FRLs prognostic signature of ccRCC was developed to distinguish patients into high-risk and low-risk groups with significant survival differences. This signature has great prognostic performance, with the area under the curve (AUC) for 1, 3, and 5 years of 0.713, 0.700, 0.726 in the training set and 0.727, 0.667, and 0.736 in the testing set, respectively. Moreover, this signature was significantly associated with immune infiltration. Correlation analysis showed that risk score was positively correlated with regulatory T cells (Tregs), activated CD4 memory T cells, CD8 T cells and follicular helper T cells, whereas it was inversely correlated with monocytes and M2 macrophages. In addition, the expression of fourteen immune checkpoint genes and nine m6A-related genes varied significantly between the two risk groups. CONCLUSION: We established a novel FRLs-based prognostic signature for patients with ccRCC, containing seven lncRNAs with precise predictive performance. The FRLs prognostic signature may play a significant role in antitumor immunity and provide a promising idea for individualized targeted therapy for patients with ccRCC.


Assuntos
Carcinoma de Células Renais , Ferroptose , Neoplasias Renais , RNA Longo não Codificante , Humanos , Carcinoma de Células Renais/genética , RNA Longo não Codificante/genética , Ferroptose/genética , Prognóstico , Neoplasias Renais/genética , Microambiente Tumoral
9.
Neurosci Lett ; 790: 136880, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36150414

RESUMO

Genetic factors play an important role in early-onset Parkinson's disease (EOPD). The genetic spectrum of patients with EOPD varies widely among different ethnicities, with extensive investigations having been performed in Caucasian populations; however, research in Chinese populations remains limited. In this study, we performed multiplex ligation-dependent probe amplification assay and whole-exome sequencing in 15 unrelated Chinese EOPD patients with age of onset before 40 years. Among them, a patient carried compound heterozygous exon duplications in Parkin (exon 3 duplication and exon 4 duplication) (6.67 %) and two patients carried the homozygous pathogenic variant (p.D331Y) in PLA2G6 (13.33 %). Three novel variants in EIF4G1 (p.P1043S, p.R1505Q, and p.P266A) were identified and classified as uncertain significance. Additionally, a risk variant in GBA (p.L483P) was detected in one patient (6.67 %). PLA2G6 (13.33 %) was the most common causative gene among our EOPD patients. Furthermore, detailed clinical features were presented. Our results broaden the genetic spectrum and clinical phenotypic spectrum of EOPD patients.


Assuntos
Doença de Parkinson , Humanos , Adulto , Doença de Parkinson/genética , Idade de Início , Mutação , Ubiquitina-Proteína Ligases/genética , China
10.
ACS Appl Bio Mater ; 5(6): 2622-2632, 2022 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-35543617

RESUMO

Designing absorbents having specific wettability toward both oil and water is the key for selective and effective oil absorption and removal. For this purpose, establishing explicit correlations between surface tension of oils and surface wettability of absorbent is crucial. In this study, we modified common low-cost cellulose sponges with various organosilanes to achieve a range of hydrophobicity/oleophilicity and then assessed their oil uptake selectivity and capability. Oil uptake was followed as mass uptake versus time and analyzed based on the spreading coefficient (S) of a liquid over a solid surface. The results showed that sponges needed to be hydrophobic, not necessarily superhydrophobic, to selectively absorb oil from an oil/water mixture. To achieve a fast uptake and a high uptake capacity, an S ≥ 0 was necessary, that is, when the sponges were completely wet by the oil. Increasing the porosity of cellulose sponge led to a slight increase in oil uptake capacity, and a greater increase resulted when bacterial cellulose sponges that consisted of smaller and more uniform voids/pores were used. S ≥ 0 could be used as a criterion for evaluating effective and rapid oil uptake for porous absorbents, especially for those containing heterogeneous pore structures, such as common cellulose sponges.


Assuntos
Celulose , Óleos , Celulose/química , Interações Hidrofóbicas e Hidrofílicas , Óleos/química , Porosidade , Molhabilidade
11.
Tree Physiol ; 42(2): 325-336, 2022 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-34387352

RESUMO

Resprouting plants are distributed in many vegetation communities worldwide. With increasing resprout age post-severe-disturbance, new stems grow rapidly at their early age, and decrease in their growth with gradually decreasing water status thereafter. However, there is little knowledge about how stem hydraulic strategies and anatomical traits vary post-disturbance. In this study, the stem water potential (Ψstem), maximum stem hydraulic conductivity (Kstem-max), water potential at 50% loss of hydraulic conductivity (Kstem  P50) and anatomical traits of Caragana korshinkii resprouts were measured during a 1- to 13-year post-disturbance period. We found that the Kstem-max decreased with resprout age from 1-year-old resprouts (84.2 mol m-1 s-1 MPa-1) to 13-year-old resprouts (54.2 mol m-1 s-1 MPa-1) as a result of decreases in the aperture fraction (Fap) and the sum of aperture area on per unit intervessel wall area (Aap). The Kstem  P50 of the resprouts decreased from 1-year-old resprouts (-1.8 MPa) to 13-year-old resprouts (-2.9 MPa) as a result of increases in vessel implosion resistance (t/b)2, wood density (WD), vessel grouping index (GI) and decreases in Fap and Aap. These shifts in hydraulic structure and function resulted in an age-based divergence in hydraulic strategies i.e., a change from an acquisitive strategy to a conservative strategy, with increasing resprout age post-disturbance.


Assuntos
Caragana , Folhas de Planta , Caules de Planta , Água , Madeira , Xilema
12.
World J Clin Cases ; 9(26): 7717-7728, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34621822

RESUMO

BACKGROUND: Non-alcoholic fatty liver disease has become the most common chronic liver disease worldwide, which originates from the accumulation of triglyceride (TG) in the liver. Patients with type 2 diabetes mellitus (T2DM) are considered to have a predisposition to hepatic steatosis. However, the influencing factors for hepatic fat accumulation in T2DM patients remain unclear. AIM: To investigate the influencing factors for hepatic fat accumulation in T2DM patients. METHODS: We enrolled 329 T2DM patients admitted to the Endocrinology Department of the First Affiliated Hospital of Soochow University, who underwent MR mDIXON-Quant examination to quantify the hepatic fat fraction (HFF). According to body mass index (BMI), the patients were divided into normal weight, overweight, and obese groups. The differences in general statistics, biochemical parameters, islet function, and HFF were compared among the three groups. The associations between HFF and other parameters and the influences of various parameters on the severity of hepatic fat accumulation were analyzed. RESULTS: The HFF of T2DM patients gradually increased in the normal weight, overweight, and obese groups (P < 0.05). Spearman correlation analysis showed that in T2DM patients, HFF was negatively correlated with age and high-density lipoprotein cholesterol (P < 0.05), whereas it was positively correlated with BMI, waist-hip ratio, fasting plasma glucose, alanine aminotransferase (ALT), aspartate aminotransferase, bilirubin, glutamyl transpeptidase, lactate dehydrogenase, albumin (ALB), uric acid (UA), total cholesterol, TG, low-density lipoprotein cholesterol (LDL-C), C-reactive protein, free triiodothyronine, fasting insulin, fasting C-peptide, and homeostasis model assessment of insulin resistance (P < 0.05). Multiple linear regression analysis showed significant positive influences of BMI, ALT, LDL-C, UA, and ALB on HFF in T2DM patients (P < 0.05). Binary logistic regression analysis showed that BMI, ALT, ALB, and LDL-C were independent risk factors for moderate to severe fatty liver in T2DM patients, and obesity increased the risk of being complicated with moderate to severe fatty liver by 4.03 times (P < 0.05). CONCLUSION: The HFF of T2DM patients increases with BMI. Higher BMI, ALT, ALB, and LDL-C are independent risk factors for moderate to severe fatty liver in T2DM patients.

13.
Environ Sci Pollut Res Int ; 28(40): 56606-56614, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34061272

RESUMO

Growing evidences suggested that lncRNAs played functional role in several cell functions such as cell growth, invasion, migration, metabolize, apoptosis, and differentiation. However, roles of lncRNA in the development and progression of IgAN remain unknown. In this reference, we indicated that PTTG3P level was overexpressed in IgAN samples compared to healthy subject. PTTG3P expression was also higher in urinary of IgAN cases than in urinary of healthy control. Furthermore, the urinary expression of PTTG3P was correlated with PTTG3P expression in intra-renal of IgAN cases. PTTG3P overexpression induced B cell growth and enhanced cyclin D1 and ki-67 expression. Overexpression of PTTG3P induced IL-1ß and IL-8 production. miR-383 level was decreased in IgAN samples compared to healthy subject. In addition, miR-383 expression was also lower in urinary of IgAN cases than in urinary of healthy control. Elevated miR-383 expression decreased luciferase intensity regulated with PTTG3P, while overexpression of miR-383 had no effect on luciferase intensity of the mutant PTTG3P. PTTG3P overexpression suppressed miR-383 expression in B cells. Ectopic miR-383 expression suppressed B cell growth and IL-1ß and IL-8 production. Finally, we showed that overexpression of PTTG3P promoted B cell growth and IL-1ß and IL-8 production via regulating miR-383. There results proved that PTTG3P played crucial role in progression of IgAN.


Assuntos
Glomerulonefrite por IGA , MicroRNAs , RNA Longo não Codificante , Linfócitos B , Glomerulonefrite por IGA/genética , Humanos , Imunoglobulina A , MicroRNAs/genética
14.
Int J Geriatr Psychiatry ; 36(10): 1514-1523, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33899959

RESUMO

BACKGROUND: Both the quality of sleep and depression impact short-term memory (STM) while they influence each other. However, the underlying mechanisms are not yet clear. Herein, we aimed to explore the mediating effect of depression between sleep quality and STM in older adults and further test the gender differences in this relationship. METHODS: A cluster sampling survey was carried out among 903 residents that were aged 60+ years in a semi-closed island of Xiamen, China, in 2019. The subjects' sleep quality and depression were measured using the Pittsburgh Sleep Quality Index (PSQI) and the 15-item Geriatric Depression Scale (GDS-15), respectively. The three-item recall test was utilized to measure STM function. Mediation analyses were performed using the structural equation model and bias-corrected bootstrap method. Next, the Wald-test was utilized to determine gender differences in the pathway. RESULTS: Overall, 355 men and 508 women, with a mean age of 69.55 and 70.97, respectively, had valid data on the main variables. Depression was found to mediate the effect of sleep quality on STM (a*b = -0.076, p < 0.05). Interestingly, while this indirect effect existed in the female group (af *bf  = -0.126, p < 0.05), it did not in the male group (am *bm  = 0.017, p = 0.677). The Wald-test indicated no gender differences in the pathway from sleep quality to depression (p = 0.303). However, the pathway from depression to STM function was found to be significantly stronger for females than males (p = 0.0198). CONCLUSION: Higher sleep quality was found to be associated with improved STM function. Furthermore, the association was found to be regulate indirectly by lower depressive symptoms for females, but directly for males. Therefore, appropriate psychological interventions may be beneficial to the maintenance of STM for older adults, particularly for women.


Assuntos
Depressão , Memória de Curto Prazo , Idoso , China/epidemiologia , Depressão/epidemiologia , Feminino , Humanos , Masculino , Sono , Inquéritos e Questionários
15.
New Phytol ; 230(5): 2001-2010, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33586157

RESUMO

Plants control water-use efficiency (WUE) by regulating water loss and CO2 diffusion through stomata. Variation in stomatal control has been reported among lineages of vascular plants, thus giving rise to the possibility that different lineages may show distinct WUE dynamics in response to water stress. Here, we compared the response of gas exchange to decreasing leaf water potential among four ferns and nine seed plant species exposed to a gradually intensifying water deficit. The data collected were combined with those from 339 phylogenetically diverse species obtained from previous studies. In well-watered angiosperms, the maximum stomatal conductance was high and greater than that required for maximum WUE, but drought stress caused a rapid reduction in stomatal conductance and an increase in WUE in response to elevated concentrations of abscisic acid. However, in ferns, stomata did not open beyond the optimum point corresponding to maximum WUE and actually exhibited a steady WUE in response to dehydration. Thus, seed plants showed improved photosynthetic WUE under water stress. The ability of seed plants to increase WUE could provide them with an advantage over ferns under drought conditions, thereby presumably increasing their fitness under selection pressure by drought.


Assuntos
Gleiquênias , Ácido Abscísico , Desidratação , Secas , Folhas de Planta , Estômatos de Plantas , Sementes , Água
17.
Plant Cell Environ ; 44(2): 399-411, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33131059

RESUMO

Drought is a cyclical phenomenon in natural environments. During dehydration, stomatal closure is mainly regulated by abscisic acid (ABA) dynamics that limit transpiration in seed plants, but following rehydration, the mechanism of gas exchange recovery is still not clear. In this study, leaf water potential (ψleaf ), stomatal conductance (gs ), leaf hydraulic conductance (Kleaf ), foliar ABA level, ethylene emission rate in response to dehydration and rehydration were investigated in four Caragana species with isohydric (Caragana spinosa and C. pruinosa) and anisohydric (C. intermedia and C. microphylla) traits. Two isohydric species with ABA-induced stomatal closure exhibited more sensitive gs and Kleaf to decreasing ψleaf than two anisohydric species which exhibited a switch from ABA to water potential-driven stomatal closure during dehydration. Following rehydration, the recovery of gas exchange was not associated with a decrease in ABA level but was strongly limited by the degradation of the ethylene emission rate in all species. Furthermore, two anisohydric species with low drought-induced ethylene production exhibited more rapid recovery in gas exchange upon rehydration. Our results indicated that ethylene is a key factor regulating the drought-recovery ability in terms of gas exchange, which may shape species adaptation to drought and potential species distribution.


Assuntos
Caragana/fisiologia , Etilenos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Transpiração Vegetal/fisiologia , Ácido Abscísico/metabolismo , Adaptação Fisiológica , Secas , Folhas de Planta/fisiologia , Estômatos de Plantas/fisiologia , Sementes/fisiologia , Especificidade da Espécie , Água/metabolismo
18.
ACS Biomater Sci Eng ; 6(12): 7051-7060, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33320596

RESUMO

Thermoresponsive polymers (TRP)s have been widely used for various applications from controlling membrane fouling in separation to cell/cell sheet harvesting in regenerative medicine. While poly(N-isopropylacrylamide) (pNIPAAm) is the most commonly used TRP, less expensive and easily processed poly(vinyl methyl ether) (PVME) also shows a hydrophilic to hydrophobic transition at 32-35 °C, near physiological conditions. In this study, we investigated the processing conditions for retaining a stable layer of PVME thin film on silica surfaces via entrapment in a 3-aminopropyltriethoxysilane (APTES) network. In addition, the thermoresponsive behaviors (TRB) of the retained PVME films were evaluated. Blend thin films of PVME/APTES with 90:10 and 50:50 mass ratios were spin-coated from their solutions in ethanol under ambient conditions and then annealed in a vacuum oven at 40, 60, 80, or 120 °C for 1, 2, or 3 days. The annealed films were then thoroughly rinsed with room temperature water and then soaked in water for 3 days. Our results showed that annealing at a temperature of ≥40 °C was necessary for retaining a PVME film on the surface. The higher annealing temperature led to greater film retention, probably due to the formation of a tighter APTES network. Regardless of processing conditions, all retained PVME films showed TRB, determined by water contact angles below and above the transition temperature of PVME. Additionally, particle attachment and protein adsorption on retained PVME films showed lower attachment or adsorption at room temperature as compared to that at 37 °C, and a greater difference was observed for the 90:10 blend where more PVME was consisted. Furthermore, human mesenchymal stem cells attached and proliferated on the retained PVME surfaces at 37 °C and rapidly detached at room temperature. These results illustrated the potential applications of PVME surfaces as thermoresponsive supports for low-fouling applications and noninvasive cell harvesting.


Assuntos
Propilaminas , Silanos , Humanos , Éteres Metílicos , Polivinil , Propriedades de Superfície
19.
Polymers (Basel) ; 12(9)2020 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-32872461

RESUMO

Natural rubber latex foam (NRLF) was reinforced with micro- and nanofibrillated cellulose at a loading content of 5-20 parts per hundred of rubber (phr) via the Dunlop process. Cellulose powder from eucalyptus pulp and bacterial cellulose (BC) was used as a microcellulose (MC) and nanocellulose (NC) reinforcing agent, respectively. NRLF, NRLF-MC, and NRLF-NC exhibited interconnected macroporous structures with a high porosity and a low-density. The composite foams contained pores with sizes in a range of 10-500 µm. As compared to MC, NC had a better dispersion inside the NRLF matrix and showed a higher adhesion to the NRLF matrix, resulting in a greater reinforcement. The most increased tensile strengths for MC and NC incorporated NRLF were found to be 0.43 MPa (1.4-fold increase) and 0.73 MPa (2.4-fold increase), respectively, by reinforcing NRLF with 5 phr MC and 15 phr NC, whereas the elongation at break was slightly reduced. Compression testing showed that the recovery percentage was improved to 34.9% (1.3-fold increase) by reinforcement with 15 phr NC, whereas no significant improvement in the recovery percentage was observed with MC. Both NRLF-MC and NRLF-NC presented hydrophobic surfaces and good thermal stability up to 300 °C. Due to their highly porous structure, after a prolong immersion in water, NRLF composites had high water uptake abilities. According to their properties, the composite foams could be further modified for use as green absorption or supporting materials.

20.
Front Genet ; 11: 713, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32754199

RESUMO

Familial Alzheimer's disease (FAD) present as a positive family history of cognitive decline, with early onset and an autosomal dominant inheritance pattern. FAD is mainly caused by the mutations in the genes encoding for amyloid precursor protein (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2). In the present study, we identified a variant (c.529T > G, p.Phe177Val) in PSEN1 across three generations in a Chinese family with FAD using whole-exome sequencing. The mean age of onset was 39 years (range: 37 to 40 years) in this family. In cell transfection studies, the mutant PSEN1 protein carrying p.Phe177Val increased both the production of Aß42 and the ratio of Aß42 over Aß40, as compared to wild-type PSEN1. Our results confirm the pathogenicity of PSEN1 p.Phe177Val variant in FAD and broaden the clinical phenotype spectrum of FAD patients with PSEN1 p.Phe177Val variant.

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