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1.
Proc Natl Acad Sci U S A ; 121(28): e2322972121, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38968116

RESUMO

Rapid accumulation of repair factors at DNA double-strand breaks (DSBs) is essential for DSB repair. Several factors involved in DSB repair have been found undergoing liquid-liquid phase separation (LLPS) at DSB sites to facilitate DNA repair. RNF168, a RING-type E3 ubiquitin ligase, catalyzes H2A.X ubiquitination for recruiting DNA repair factors. Yet, whether RNF168 undergoes LLPS at DSB sites remains unclear. Here, we identified K63-linked polyubiquitin-triggered RNF168 condensation which further promoted RNF168-mediated DSB repair. RNF168 formed liquid-like condensates upon irradiation in the nucleus while purified RNF168 protein also condensed in vitro. An intrinsically disordered region containing amino acids 460-550 was identified as the essential domain for RNF168 condensation. Interestingly, LLPS of RNF168 was significantly enhanced by K63-linked polyubiquitin chains, and LLPS largely enhanced the RNF168-mediated H2A.X ubiquitination, suggesting a positive feedback loop to facilitate RNF168 rapid accumulation and its catalytic activity. Functionally, LLPS deficiency of RNF168 resulted in delayed recruitment of 53BP1 and BRCA1 and subsequent impairment in DSB repair. Taken together, our finding demonstrates the pivotal effect of LLPS in RNF168-mediated DSB repair.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , Proteína 1 de Ligação à Proteína Supressora de Tumor p53 , Ubiquitina-Proteína Ligases , Ubiquitinação , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Humanos , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética , Ubiquitina/metabolismo , Histonas/metabolismo , Histonas/genética , Poliubiquitina/metabolismo
2.
Reprod Biol Endocrinol ; 22(1): 19, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38308329

RESUMO

BACKGROUND: Previous studies have suggested that oil-based contrast agents used during hysterosalpingography (HSG) in infertile patients can enhance fertility. However, limited research has investigated the effect of oil-based contrast medium specifically in individuals with endometriosis-related infertility. OBJECTIVE: This study aims to explore the impact of oil-based contrast medium on fertility outcomes in women with endometriosis-related infertility. METHODS: Conducted at the First Affiliated Hospital of Guangxi Medical University (January 2020 to June 2022), the study included 512 patients undergoing HSG. Patients were categorized into oil-based and non-oil-based groups, and after propensity score matching, demographic characteristics were compared. Main outcomes included clinical pregnancy rates, live birth rates, early miscarriage rates, and ectopic pregnancy rates. RESULTS: In our analysis, the Oil-based group showed significantly better outcomes compared to the Non-oil-based group. Specifically, the Oil-based group had higher clinical pregnancy rates (51.39% vs. 27.36%) and increased live birth rates (31.48% vs. 19.93%). This trend held true for expectant treatment, IUI, and IVF/ICSI, except for surgical treatment where no significant difference was observed. After adjusting for various factors using propensity score matching, the Non-oil-based group consistently exhibited lower clinical pregnancy rates compared to the Oil-based group. The Odds Ratio (OR) was 0.38 (95%CI: 0.27-0.55) without adjustment, 0.34 (0.22-0.51) in multivariable analysis, 0.39 (0.27-0.57) using inverse probability of treatment weighting (IPTW), and 0.22 (0.14-0.35) in propensity score matching. CONCLUSION: Oil-based contrast medium used in HSG for women with endometriosis-related infertility is associated with higher clinical pregnancy rates and live birth rates compared to Non-oil-based contrast medium.


Assuntos
Endometriose , Infertilidade Feminina , Gravidez , Humanos , Feminino , Meios de Contraste , Histerossalpingografia , Endometriose/complicações , Endometriose/diagnóstico por imagem , Infertilidade Feminina/diagnóstico por imagem , Infertilidade Feminina/etiologia , Infertilidade Feminina/terapia , Estudos Retrospectivos , China/epidemiologia , Fertilidade , Taxa de Gravidez , Nascido Vivo
3.
Reprod Biomed Online ; 49(3): 103914, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38917774

RESUMO

RESEARCH QUESTION: What impact does dehydroepiandrosterone (DHEA) have on ovarian angiogenesis and function in a rat model of with premature ovarian insufficiency (POI), and what are the potential mechanisms of action? DESIGN: DHEA was added to a culture of human microvascular endothelial cells (HMEC-1) to investigate its effects on cell proliferation, migration and tube formation. A rat model of POI was established by intraperitoneal injection of cyclophosphamide, followed by continuous oral administration of DHEA or vehicle for 28 days. Ovarian angiogenesis, follicular growth and granulosa cell survival in ovarian tissues were assessed through haematoxylin and eosin staining, immunohistochemistry and TdT (terminal deoxynucleotidyl transferase)-mediated dUTP nick-end labelling (TUNEL). The effect of DHEA on the fertility of rats with POI was evaluated in pregnant animals. The expression levels of characteristic genes and proteins in the hypoxia-inducible factor (HIF)-1α/vascular endothelial growth factor (VEGF) pathway was determined using quantitative reverse transcription PCR and western blotting. RESULTS: In-vitro experiments revealed that DHEA stimulated the proliferation, migration and tube formation of HMEC-1. In in-vivo studies, DHEA treatment improved the disruption of the oestrous cycle and hormone imbalances in POI rats. Key genes in the HIF-1α/VEGF pathway exhibited up-regulated expression, promoting ovarian angiogenesis in POI rats, and enhancing follicular development and granulosa cell survival, thereby restoring fertility in rats. CONCLUSIONS: DHEA can potentially restore ovarian function in rats with cyclophosphamide-induced POI by up-regulating HIF-1α/VEGF signalling, which promotes the growth of blood vessels in the ovaries.

4.
PLoS Comput Biol ; 19(2): e1010914, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36848379

RESUMO

Environmentally induced or epigenetic-related beta-cell dysfunction and insulin resistance play a critical role in the progression to diabetes. We developed a mathematical modeling framework capable of studying the progression to diabetes incorporating various diabetogenic factors. Considering the heightened risk of beta-cell defects induced by obesity, we focused on the obesity-diabetes model to further investigate the influence of obesity on beta-cell function and glucose regulation. The model characterizes individualized glucose and insulin dynamics over the span of a lifetime. We then fit the model to the longitudinal data of the Pima Indian population, which captures both the fluctuations and long-term trends of glucose levels. As predicted, controlling or eradicating the obesity-related factor can alleviate, postpone, or even reverse diabetes. Furthermore, our results reveal that distinct abnormalities of beta-cell function and levels of insulin resistance among individuals contribute to different risks of diabetes. This study may encourage precise interventions to prevent diabetes and facilitate individualized patient treatment.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Humanos , Diabetes Mellitus Tipo 2/complicações , Resistência à Insulina/fisiologia , Insulina , Obesidade/complicações , Glucose , Glicemia
5.
Biol Reprod ; 109(5): 736-748, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37602667

RESUMO

BACKGROUND: Invasion of the endometrium by trophoblast cells is a key event during pregnancy, although the underlying mechanism remains unclear. Aquaporin 9 (AQP 9) is expressed in many eukaryotes and is associated with cell invasion. The objective of this study was to evaluate the significance of AQP9 in recurrent spontaneous abortion. METHODS: We screened the GSE22490 dataset and further differentiated aquaporin 9 expression in villi. AQP9 was evaluated as one of the key factors in abortion by injecting AQP9 overexpressed plasmid into the uterus of CD1 mice. Trophoblast cells were transfected with AQP9-overexpressing plasmid or siAQP9 to measure cell proliferation, migration, invasion, and apoptosis. Western blot was used to measure changes in the expression of invasion, epithelial-mesenchymal transformation process, and PI3K/AKT pathway. Finally, the role of AQP9 in PI3K/AKT signaling pathway was determined using the PI3K/AKT inhibitor, LY294002, and activator, 740Y-P. RESULTS: AQP9 is highly expressed in recurrent spontaneous abortion villus. Intrauterine injections of AQP9-overexpressing plasmid into CD1 mice resulted in atrophy and blackness of the gestational sac and increased the absorption rate, it is the causative factor of abortion. AQP9 upregulation inhibited the proliferation, invasion, migration, and epithelial-mesenchymal transformation process in vitro of trophoblast cells and increased cell apoptosis. The opposite result was observed after silencing AQP9. AQP9 overexpression also inhibited the PI3K/AKT pathway. LY294002 and 740Y-P partially recovered AQP9-induced trophoblast invasion and migration via the PI3K/AKT pathway. CONCLUSIONS: AQP9 reduces the invasive ability of trophoblast cells by regulating PI3K/AKT signaling pathway, participating in recurrent spontaneous abortion.


Assuntos
Aborto Espontâneo , Aquaporinas , Fragmentos de Peptídeos , Receptores do Fator de Crescimento Derivado de Plaquetas , Humanos , Gravidez , Feminino , Animais , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Trofoblastos/metabolismo , Aquaporinas/genética , Aquaporinas/metabolismo , Proliferação de Células , Transição Epitelial-Mesenquimal , Movimento Celular
6.
Mol Ecol ; 32(11): 2884-2897, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36811404

RESUMO

Many animals, including insects, exhibit plasticity of body colour in response to environmental changes. Varied expression of carotenoids, major cuticle pigments, significantly contributes to body colour flexibility. However, the molecular mechanisms by which environmental cues regulate carotenoid expression remain largely unknown. In this study, we used the ladybird Harmonia axyridis as a model to investigate the photoperiodic-responsive plasticity of elytra coloration and its endocrine regulation. It was found that H. axyridis females under long-day conditions develop elytra that are much redder than those under short-day conditions, resulting from the differential accumulation of carotenoids. Exogenous hormone application and RNAi-mediated gene knockdown indicate that carotenoid deposition was directed through the juvenile hormone (JH) receptor-mediated canonical pathway. Moreover, we characterized an SR-BI/CD36 (SCRB) gene SCRB10 as the carotenoid transporter responding to JH signalling and regulating the elytra coloration plasticity. Taken together, we propose that JH signalling transcriptionally regulates the carotenoid transporter gene for the photoperiodic coloration plasticity of elytra in the beetles, which reveals a novel role of the endocrine system in the regulation of carotenoid-associated animal body coloration under environmental stimuli.


Assuntos
Besouros , Animais , Feminino , Besouros/genética , Pigmentação/genética , Carotenoides , Interferência de RNA
7.
Reprod Biol Endocrinol ; 21(1): 120, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38087312

RESUMO

BACKGROUND: Survival rates of young women undergoing cancer treatment have substantially improved, with a focus on post-treatment quality of life. Ovarian tissue transplantation (OTT) is a viable option to preserve fertility; however, there is no consensus on the optimal transplantation site. Most studies on OTT are nonrandomized controlled trials with limited sample sizes and uncontrolled statistical analyses, leaving the question of which transplant site yields the highest chance of achieving a live birth unanswered. OBJECTIVE: This meta-analysis aimed to assess the effect of different ovarian transplant sites on postoperative reproductive outcomes. METHODS: We adhered to the PRISMA Reporting Items for Systematic Reviews and Meta-Analyses recommendations. Systematic searches were conducted in PubMed, Embase, Web of Science, and the Cochrane Library from inception to September 17, 2023. The inclusion criteria were as follows: (1) women who underwent OTT with a desire for future childbirth, and (2) reports of specific transplant sites and corresponding pregnancy outcomes. The exclusion criteria included the inability to isolate or extract relevant outcome data, case reports, non-original or duplicate data, and articles not written in English. RESULTS: Twelve studies (201 women) were included in the meta-analysis of cumulative live birth rates (CLBR) after OTT. The CLBR, which encompasses both spontaneous pregnancies and those achieved through assisted reproductive technology (ART) following OTT to the ovarian site, was 21% (95% CI: 6-40, I2: 52.81%, random effect). For transplantation to the pelvic site, the live birth rate was 30% (95% CI: 20-40, I2: 0.00%, fixed effect). Combining transplantation to both the pelvic and ovarian sites resulted in a live birth rate of 23% (95% CI: 11-36, I2: 0.00%, fixed effect). Notably, heterotopic OTT yielded a live birth rate of 3% (95% CI: 0-17, I2: 0.00%, fixed effect). CONCLUSION: Pregnancy outcomes were not significantly different after orthotopic ovarian transplantation, and pregnancy and live birth rates after orthotopic OTT were significantly higher than those after ectopic transplantation. REGISTRATION NUMBER: INPLASY202390008.


Assuntos
Ovário , Qualidade de Vida , Gravidez , Feminino , Humanos , Técnicas de Reprodução Assistida , Resultado da Gravidez , Gravidez Múltipla , Nascido Vivo , Taxa de Gravidez
8.
BMC Cancer ; 23(1): 1128, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37986152

RESUMO

BACKGROUND: The roles of low molecular mass polypeptide 2 (LMP2) and transporter-associated with antigen processing (TAP2) in tumorigenesis are controversial. Here we aimed to explore the effect of LMP2 and TAP2 on the oncogenesis and metastasis of cervical cancer cells. METHODS: The expressions of LMP2 and TAP2 in cervical cancer and normal tissues were determined by qPCR. Plate colony formation, cell counting kit-8 analysis and in vivo tumor xenograft assays were used to detect the tumor growth. Wound healing and transwell assays were used to detect the metastasis of cervical cancer. Gelatin zymography and western blotting assays were used to detect the effect of LMP2 and TAP2 on the EMT and Wnt/ß-catenin pathway in cervical cancer cells. RESULTS: In the present study, we reported that LMP2 and TAP2 levels were overexpressed in cervical cancer. Overexpression of LMP2 and TAP2 impaired the proliferation of Hela cells. In vivo studies substantiated that LMP2 and TAP2 antagonized tumor growth. Likewise, LMP2 and TAP2 overexpression decreased the migration and invasion ability of Hela cells by regulating the process of epithelial-mesenchymal transition (EMT). Mechanically, LMP2 and TAP2 subverted the protein abundance of Wnt1 and ß-catenin, thereby downregulating their downstream targets Cyclin D1 and c-Myc. In addition, Wnt1 overexpression partially rescued the observed consequences of ectopic expression of LMP2 and TAP2 in cervical cancer cells. Taken together, our study revealed that LMP2 and TAP2 suppress the oncogenesis and metastasis of cervical cancer cells by Wnt/ß-catenin pathway and altering EMT. CONCLUSION: LMP2 and TAP2 may inhibit the oncogenesis and metastasis of cervical cancer cells by inhibiting the process of EMT and the Wnt/ß-catenin signaling pathway, which may provide important insight into prospective targets for the treatment of cervical cancer.


Assuntos
Neoplasias do Colo do Útero , beta Catenina , Feminino , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Via de Sinalização Wnt , Neoplasias do Colo do Útero/genética , Células HeLa , Transição Epitelial-Mesenquimal/genética , Carcinogênese/genética , Proliferação de Células , Movimento Celular , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Membro 3 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/metabolismo
9.
Reprod Biomed Online ; 46(3): 425-435, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36604215

RESUMO

RESEARCH QUESTION: What are the levels of progranulin (PGRN) expression in primary endometrial stromal cells (ESC) and endometrial tissue in patients with endometriosis (EMS)? What is the role and mechanism of action of PGRN in EMS? DESIGN: Endometrial tissue was collected from 30 patients, 15 with EMS (EMS group) and 15 without EMS (non-EMS group). PGRN expression in endometrial tissue and ESC was analysed by immunohistochemistry, immunofluorescence, western blotting and quantitative reverse transcription polymerase chain reaction. PGRN overexpression and silencing ESC were established with lentivirus to detect the effect on proliferation, invasion and migration. The relationship between PGRN and the phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) signalling pathway was verified by western blotting. A rescue assay was performed with PI3K inhibitor treatment. RESULTS: The PGRN expression was significantly higher in EMS samples. PGRN up-regulation promoted proliferation (P = 0.007), migration (P = 0.002) and invasion (P < 0.001) of eutopic endometrial stromal cells (EUESC). The ratio of p-AKT/AKT was higher in the overexpression PGRN (ovPGRN) group than in the overexpression-NC (ovNC) group (P = 0.004). Silencing PGRN produced the opposite results, and LY2940002 addition reversed the effect of PGRN up-regulation on the proliferation, invasion and migration of EUESC. CONCLUSIONS: PGRN might promote the proliferation, invasion and migration of EUESC via the PI3K/Akt signalling pathway. These preliminary in-vitro findings may present a new perspective and inspire further study of the mechanism of EMS.


Assuntos
Endometriose , Proteínas Proto-Oncogênicas c-akt , Feminino , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Endometriose/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Progranulinas/metabolismo , Progranulinas/farmacologia , Movimento Celular , Proliferação de Células , Células Estromais/metabolismo , Endométrio/metabolismo
10.
Analyst ; 148(20): 5041-5049, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37667671

RESUMO

Uromodulin (Umod, Tamm-Horsfall protein) is the most abundant urinary N-glycoprotein produced exclusively by the kidney. It can form filaments to antagonize the adhesion of uropathogens. However, the site-specific N-glycosylation signatures of Umod in healthy individuals and patients with IgA nephropathy (IgAN) remain poorly understood due to the lack of suitable isolation and analytical methods. In this study, we first presented a simple and fast method based on diatomaceous earth adsorption to isolate Umod. These isolated glycoproteins were digested by trypsin and/or Glu-C. Intact N-glycopeptides with or without HILIC enrichment were analyzed using our developed EThcD-sceHCD-MS/MS. Based on the optimized workflow, we identified a total of 780 unique intact N-glycopeptides (7 N-glycosites and 152 N-glycan compositions) from healthy individuals. As anticipated, these glycosites exhibited glycoform heterogeneity. Almost all N-glycosites were modified completely by the complex type, except for one N-glycosite (N275), which was nearly entirely occupied by the high-mannose type for mediating Umod's antiadhesive activity. Then, we compared the N-glycosylation of Umod between healthy controls (n = 9) and IgAN patients (n = 9). The N-glycosylation of Umod in IgAN patients will drastically decrease and be lost. Finally, we profiled the most comprehensive site-specific N-glycosylation map of Umod and revealed its alterations in IgAN patients. Our method provides a high-throughput workflow for characterizing the N-glycosylation of Umod, which can aid in understanding its roles in physiology and pathology, as well as serving as a potential diagnostic tool for evolution of renal tubular function.

11.
BMC Womens Health ; 23(1): 344, 2023 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-37391748

RESUMO

BACKGROUND: The aim of this retrospective study was to investigate whether oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone) are beneficial for patients with repeated implantation failure (RIF) and chronic endometritis (CE) to improve clinical pregnancy outcomes. METHODS: Patients with RIF and CE were diagnosed using hysteroscopy and histology together. A total of 42 patients were enrolled in the study. All patients received oral antibiotics (doxycycline combined with metronidazole) and 22 patients underwent intrauterine perfusion (gentamicin combined with dexamethasone) immediately after the end of oral antibiotic therapy. Pregnancy outcomes were evaluated during the first in vitro fertilization (IVF) and embryo transfer (ET) cycle. RESULTS: For the first D3 ET after treatment with oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone), higher embryo implantation rate (30.95% vs. 26.67%, P = 0.0308), clinical pregnancy rate (30% vs. 50%, P < 0.001), live birth rate (33.33% vs. 45.45%, P < 0.0001). No fetal malformations or ectopic pregnancies were observed. CONCLUSION: We report oral antibiotics (doxycycline and metronidazole) combined with intrauterine perfusion (gentamicin and dexamethasone) as a novel treatment for CE to improve the outcomes of successful pregnancy compared with those of oral antibiotics alone.


Assuntos
Doxiciclina , Endometrite , Feminino , Gravidez , Humanos , Metronidazol/uso terapêutico , Resultado da Gravidez , Endometrite/tratamento farmacológico , Estudos Retrospectivos , Perfusão , Antibacterianos/uso terapêutico , Transferência Embrionária , Fertilização in vitro , Gentamicinas/uso terapêutico , Doença Crônica , Implantação do Embrião , Dexametasona
12.
J Math Biol ; 87(5): 73, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37856001

RESUMO

This paper investigates the dynamics of a glucose-insulin regulatory system model that incorporates: (1) insulin-degrading enzyme in the insulin equation; and (2) discrete time delays respectively in the insulin production term, hepatic glucose production term, and the insulin-degrading enzyme. We provide rigorous results of our model including the asymptotic stability of the equilibrium solution and the existence of Hopf bifurcation. We show that analytically and numerically at a certain value the time delays driven stability or instability occurs when the corresponding model has an interior equilibrium. Moreover, we illustrate the oscillatory regulation and insulin secretion via numerical simulations, which show that the model dynamics exhibit physiological observations and more information by allowing parameters to vary. Our results may provide useful biological insights into diabetes for the glucose-insulin regulatory system model.


Assuntos
Insulinas , Insulisina , Simulação por Computador , Fatores de Tempo , Modelos Biológicos
13.
BMC Plant Biol ; 21(1): 404, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488625

RESUMO

BACKGROUND: Brassica carinata (A) Braun has recently gained increased attention across the world as a sustainable biofuel crop. B. carinata is grown as a summer crop in many regions where high temperature is a significant stress during the growing season. However, little research has been conducted to understand the mechanisms through which this crop responds to high temperatures. Understanding traits that improve the high-temperature adaption of this crop is essential for developing heat-tolerant varieties. This study investigated lipid remodeling in B. carinata in response to high-temperature stress. A commercial cultivar, Avanza 641, was grown under sunlit-controlled environmental conditions in Soil-Plant-Atmosphere-Research (SPAR) chambers under optimal temperature (OT; 23/15°C) conditions. At eight days after sowing, plants were exposed to one of the three temperature treatments [OT, high-temperature treatment-1 (HT-1; 33/25°C), and high-temperature treatment-2 (HT-2; 38/30°C)]. The temperature treatment period lasted until the final harvest at 84 days after sowing. Leaf samples were collected at 74 days after sowing to profile lipids using electrospray-ionization triple quadrupole mass spectrometry. RESULTS: Temperature treatment significantly affected the growth and development of Avanza 641. Both high-temperature treatments caused alterations in the leaf lipidome. The alterations were primarily manifested in terms of decreases in unsaturation levels of membrane lipids, which was a cumulative effect of lipid remodeling. The decline in unsaturation index was driven by (a) decreases in lipids that contain the highly unsaturated linolenic (18:3) acid and (b) increases in lipids containing less unsaturated fatty acids such as oleic (18:1) and linoleic (18:2) acids and/or saturated fatty acids such as palmitic (16:0) acid. A third mechanism that likely contributed to lowering unsaturation levels, particularly for chloroplast membrane lipids, is a shift toward lipids made by the eukaryotic pathway and the channeling of eukaryotic pathway-derived glycerolipids that are composed of less unsaturated fatty acids into chloroplasts. CONCLUSIONS: The lipid alterations appear to be acclimation mechanisms to maintain optimal membrane fluidity under high-temperature conditions. The lipid-related mechanisms contributing to heat stress response as identified in this study could be utilized to develop biomarkers for heat tolerance and ultimately heat-tolerant varieties.


Assuntos
Brassica/metabolismo , Metabolismo dos Lipídeos , Lipídeos/química , Folhas de Planta/metabolismo , Estresse Fisiológico , Temperatura Alta
14.
J Environ Manage ; 270: 110878, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721317

RESUMO

Located in the hinterland of the Eurasian continent, the inland areas of northwestern China have an arid climate and are confronted with continuing challenges in water resources quantity and quality. Reclaimed water plays an important role in maintaining the sustainable use of urban water resources, especially in arid regions. In this paper, a system dynamics urban reclaimed water model (SDURWM) considering the status of arid regions in northwestern China was constructed. The supply and demand balance index (RWB) and the utilization efficiency index (RWUE) of reclaimed water were proposed as evaluation indicators. The potential of reclaimed water utilization (2016-2025) in three typical cities with similar natural environments and population sizes but with large economic differences were estimated by the SD model. Then the relevant values of reclaimed water quota, supply and resident awareness were adjusted within the range of 10%-20%. The predicted results from intervention demonstrate that the RWB of three cities will be closer or maintain to the ideal value, and that the RWUE will increase by about 0.1, compared with the non-intervention results. This indicates that a minor change of the targeted policies can invigorate the capacity of reclaimed water use in droughty cities. This paper provides some effective solutions for the government's planning of developing the potential of reclaimed water.


Assuntos
Purificação da Água , Água , China , Cidades , Abastecimento de Água
15.
Langmuir ; 33(50): 14295-14303, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29206047

RESUMO

Macroporous materials polymerized from high internal phase emulsions (PolyHIPEs) possess well-defined interconnected porous structures and tunable device shapes. This provides interesting property characteristics well-suited for a variety of applications. However, such materials also demonstrate poor mechanical performances, which limit their potential use. As will be demonstrated, this results from the high surfactant content required by PolyHIPEs. Herein, a new approach is introduced for designing a highly efficient polymeric surfactant, which generates interconnected pores in PolyHIPEs through designing an incompatible surfactant and skeleton material. The surfactant also possesses a hyperbranched topology, which combines the strong amphipathy of small molecular surfactants and the nanosphere structure of Pickering emulsifiers to provide an excellent colloidal stability to HIPEs. A hyperbranched polyethylene having pendant sodium sulfonate groups (HBPE-SO3Na) was thus designed and synthesized via chain walking copolymerization of ethylene and 2-trimethylsilyloxyethyl acrylate followed by sulfonation. Stable HIPEs of styrene/divinylbenzene and water at a weight ratio of 1 to 5 were obtained with using HBPE-SO3Na. The polymerization of HIPEs produced interconnected macroporous polystyrenes (PSs) at a substantially lower surfactant content, for example, 0.5 wt % HBPE-SO3Na. The compressive Young's moduli of PolyHIPEs reached 104-111 MPa with 0.5-2 wt % HBPE-SO3Na, which is the first reported case of a PS-based PolyHIPE achieving its theoretical modulus. The PolyHIPE was used to support Au nanoparticles and embed in a column for oxidation of dimethylphenylsilane. A complete conversion of dimethylphenylsilanol was achieved with low column back pressure in a 50 h continuous reaction with no degradation of PolyHIPE integrity and mechanical property.

16.
Chaos ; 27(11): 114324, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29195308

RESUMO

Type 2 diabetes mellitus (T2DM) has become prevalent pandemic disease in view of the modern life style. Both diabetic population and health expenses grow rapidly according to American Diabetes Association. Detecting the potential onset of T2DM is an essential focal point in the research of diabetes mellitus. The intravenous glucose tolerance test (IVGTT) is an effective protocol to determine the insulin sensitivity, glucose effectiveness, and pancreatic ß-cell functionality, through the analysis and parameter estimation of a proper differential equation model. Delay differential equations have been used to study the complex physiological phenomena including the glucose and insulin regulations. In this paper, we propose a novel approach to model the time delay in IVGTT modeling. This novel approach uses two parameters to simulate not only both discrete time delay and distributed time delay in the past interval, but also the time delay distributed in a past sub-interval. Normally, larger time delay, either a discrete or a distributed delay, will destabilize the system. However, we find that time delay over a sub-interval might not. We present analytically some basic model properties, which are desirable biologically and mathematically. We show that this relatively simple model provides good fit to fluctuating patient data sets and reveals some intriguing dynamics. Moreover, our numerical simulation results indicate that our model may remove the defect in well known Minimal Model, which often overestimates the glucose effectiveness index.


Assuntos
Glucose/administração & dosagem , Modelos Biológicos , Simulação por Computador , Teste de Tolerância a Glucose , Fatores de Tempo
17.
Acta Physiol Plant ; 39(10)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31736527

RESUMO

In order to explore the salt-stress responses of two rice varieties, the physiological responses and biochemical responses were investigated using proteomics and classical biochemical methods. The results showed that the seedling growth was inhibited under salt condition in two rice varieties, the seedling growth in the tolerant variety was better than the sensitive variety. The sensitive variety(L7) appeared obvious salt-injury under 3-day salt stress, the tolerant variety (T07339) keep normal growth under 7-day salt stress except that the shoot length was decreased. Through the growth-parameters analysis, most of them in L7 were restrained by salinity and most in T07339 were unaffected. In T07339, the fresh root weight, the content of chlorophyll and the fresh shoot weight were even increased after 7 days of salt stress. A comparison of two-dimensional gel electrophoresis (2-DGE) protein profiles revealed 8 differently expressed proteins. Four proteins were expressed in different pattern between sensitive and tolerant varieties. These results provide novel insights into the investigations of the salt-response proteins that involved in improved salt tolerance.

19.
IEEE Trans Neural Netw Learn Syst ; 35(3): 3365-3379, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37310817

RESUMO

This article investigates the fault-tolerant formation control (FTFC) problem for networked fixed-wing unmanned aerial vehicles (UAVs) against faults. To constrain the distributed tracking errors of follower UAVs with respect to neighboring UAVs in the presence of faults, finite-time prescribed performance functions (PPFs) are developed to transform the distributed tracking errors into a new set of errors by incorporating user-specified transient and steady-state requirements. Then, the critic neural networks (NNs) are developed to learn the long-term performance indices, which are used to evaluate the distributed tracking performance. Based on the generated critic NNs, actor NNs are designed to learn the unknown nonlinear terms. Moreover, to compensate for the reinforcement learning errors of actor-critic NNs, nonlinear disturbance observers (DOs) with skillfully constructed auxiliary learning errors are developed to facilitate the FTFC design. Furthermore, by using the Lyapunov stability analysis, it is shown that all follower UAVs can track the leader UAV with predesigned offsets, and the distributed tracking errors are finite-time convergent. Finally, comparative simulation results are presented to show the effectiveness of the proposed control scheme.

20.
Food Chem ; 438: 137939, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38006697

RESUMO

A novel carbon dot/g-C3N4 nanocomposite (CCN) exhibiting enhanced photocatalytic activity was developed and used as a photoactive nanofiller to construct corn starch/carboxymethyl cellulose (CS/CMC)-based functional films. The morphologies and structures of the CCN-CS/CMC composite films were investigated with scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The effects of the CCN on the physicochemical properties and antibacterial activities of the films were analyzed. The properties of the films were optimized with the addition of CCN (0.20 mg/mL), and the tensile strength of the film was increased to 11.9 MPa and the water contact angle was increased to 103.39°. The optimal active film showed > 99.9 % antibacterial efficiencies against Escherichia coli and Staphylococcus aureus under visible light and prolonged the shelf lives of bananas for more than four days compared to the 4-day shelf life of the control. This work provides a novel route for developing antimicrobial active packaging.


Assuntos
Anti-Infecciosos , Nanocompostos , Carbono , Embalagem de Alimentos/métodos , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Escherichia coli , Nanocompostos/química
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