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1.
FASEB J ; 38(13): e23743, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38877852

RESUMO

Kisspeptin signaling regulates energy homeostasis. Adiposity is the principal source and receiver of peripheral Kisspeptin, and adipose Kiss1 metastasis suppressor (Kiss1) gene expression is stimulated by exercise. However, whether the adipose Kiss1 gene regulates energy homeostasis and plays a role in adaptive alterations during prolonged exercise remains unknown. Here, we investigated the role of Kiss1 role in mice and adipose tissues and the adaptive changes it induces after exercise, using adipose-specific Kiss1 knockout (Kiss1adipoq-/-) and adeno-associated virus-induced adipose tissue Kiss1-overexpressing (Kiss1adipoq over) mice. We found that adipose-derived kisspeptin signal regulates lipid and glucose homeostasis to maintain systemic energy homeostasis, but in a sex-dependent manner, with more pronounced metabolic changes in female mice. Kiss1 regulated adaptive alterations of genes and proteins in tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OxPhos) pathways in female gWAT following prolonged aerobic exercise. We could further show that adipose Kiss1 deficiency leads to reduced peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α) protein content of soleus muscle and maximum oxygen uptake (VO2 max) of female mice after prolonged exercise. Therefore, adipose Kisspeptin may be a novel adipokine that increases organ sensitivity to glucose, lipids, and oxygen following exercise.


Assuntos
Tecido Adiposo , Metabolismo Energético , Homeostase , Kisspeptinas , Camundongos Knockout , Condicionamento Físico Animal , Animais , Kisspeptinas/metabolismo , Kisspeptinas/genética , Feminino , Camundongos , Condicionamento Físico Animal/fisiologia , Masculino , Tecido Adiposo/metabolismo , Camundongos Endogâmicos C57BL , Adaptação Fisiológica
2.
Plant Cell ; 33(4): 1196-1211, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-33604650

RESUMO

Arabidopsis thaliana CONSTANS (CO) is an essential transcription factor that promotes flowering by activating the expression of the floral integrator FLOWERING LOCUS T (FT). A number of histone modification enzymes involved in the regulation of flowering have been identified, but the involvement of epigenetic mechanisms in the regulation of the core flowering regulator CO remains unclear. Previous studies have indicated that the transcription factors, FLOWERING BHLH1 (FBH1), FBH2, FBH3, and FBH4, function redundantly to activate the expression of CO. In this study, we found that the KDM3 group H3K9 demethylase JMJ28 interacts with the FBH transcription factors to activate CO by removing the repressive mark H3K9me2. The occupancy of JMJ28 on the CO locus is decreased in the fbh quadruple mutant, suggesting that the binding of JMJ28 is dependent on FBHs. Furthermore, genome-wide occupancy profile analyses indicate that the binding of JMJ28 to the genome overlaps with that of FBH3, indicating a functional association of JMJ28 and FBH3. Together, these results indicate that Arabidopsis JMJ28 functions as a CO activator by interacting with the FBH transcription factors to remove H3K9me2 from the CO locus.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Ligação a DNA/metabolismo , Flores/fisiologia , Histona Desmetilases/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Ligação a DNA/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Histona Desmetilases/genética , Histonas/metabolismo , Lisina/metabolismo , Plantas Geneticamente Modificadas/genética , Fatores de Transcrição/genética
3.
Mol Pharm ; 21(7): 3684-3692, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38899595

RESUMO

Early detection of pulmonary fibrosis is a critical yet insufficiently met clinical necessity. This study evaluated the effectiveness of FAPI-LM3, a 68Ga-radiolabeled heterobivalent molecular probe that targets fibroblast activating protein (FAP) and somatostatin receptor 2 (SSTR2), in the early detection of pulmonary fibrosis, leveraging its potential for early disease identification. A bleomycin-induced early pulmonary fibrosis model was established in C57BL/6 mice for 7 days. FAP and SSTR2 expression levels were quantitatively assessed in human idiopathic pulmonary fibrosis lung tissue samples and bleomycin-treated mouse lung tissues by using western blotting, real-time quantitative PCR (RT-qPCR), and immunofluorescence techniques. The diagnostic performance of FAPI-LM3 was investigated by synthesizing monomeric radiotracers 68Ga-FAPI-46 and 68Ga-DOTA-LM3 alongside the heterobivalent probe 68Ga-FAPI-LM3. These imaging radiopharmaceuticals were used in small-animal PET to compare their uptake in fibrotic and normal lung tissues. Results indicated significant upregulation of FAP and SSTR2 at both RNA and protein levels in fibrotic lung tissues compared with that in normal controls. PET imaging demonstrated significantly enhanced uptake of the 68Ga-FAPI-LM3 probe in fibrotic lung tissues, with superior visual effects compared to monomeric tracers. At 60 min postinjection, early stage fibrotic tissues (day 7) demonstrated low-to-medium uptake of monomeric probes, including 68Ga-DOTA-LM3 (0.45 ± 0.04% ID/g) and 68Ga-FAPI-46 (0.78 ± 0.09% ID/g), whereas the uptake of the heterobivalent probe 68Ga-FAPI-LM3 (1.90 ± 0.10% ID/g) was significantly higher in fibrotic lesions than in normal lung tissue. Blockade experiments confirmed the specificity of 68Ga-FAPI-LM3 uptake, which was attributed to synergistic targeting of FAP and SSTR2. This study demonstrates the potential of 68Ga-FAPI-LM3 for early pulmonary fibrosis detection via molecular imaging, offering significant benefits over monomeric tracers 68Ga-FAPI-46 and 68Ga-DOTA-LM3. This strategy offers new possibilities for noninvasive and precise early detection of pulmonary fibrosis.


Assuntos
Radioisótopos de Gálio , Camundongos Endogâmicos C57BL , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Receptores de Somatostatina , Animais , Camundongos , Receptores de Somatostatina/metabolismo , Humanos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/química , Fibrose Pulmonar/diagnóstico por imagem , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/induzido quimicamente , Pulmão/diagnóstico por imagem , Pulmão/patologia , Pulmão/metabolismo , Masculino , Bleomicina , Endopeptidases/metabolismo , Modelos Animais de Doenças , Feminino , Fibrose Pulmonar Idiopática/diagnóstico por imagem , Fibrose Pulmonar Idiopática/metabolismo , Proteínas de Membrana/metabolismo , Serina Endopeptidases/metabolismo , Quinolinas
4.
J Exerc Sci Fit ; 22(2): 168-177, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38464601

RESUMO

Background: Resistance training (RT) and protein supplementation have beneficial effects on the human body. However, it is unknown if RT's health-promoting benefits are enhanced by food-borne protein, such as cheese supplements. This study investigated at how the body composition, lipid profile, muscle strength and intestinal microbiota changed following four weeks of RT combined with cheese supplementation. Methods: Thirty-five male and untrained adults were divided into 4 groups [control group (CON), low-dose group (LG), medium-dose group (MG), and high-dose group (HG)] and underwent a 4-week RT (3 times/week) in combination with cheese supplementation. Participants received 108 g (LG), 216 g (MG), or 324 g (HG) of cheese on the day of RT, and each serving (108 g) of cheese contained 6.7 g of food-borne protein. The RT program was a whole-body program with movements such as chest presses, leg presses, seated rowing, knee extensions and triceps pushdown. The exercise consisted of 3 sets of 8-12 repetitions at 70%RM, with a 120-s break in between. Body parameters (body composition, lipid profile and muscle strength) were assessed at baseline and after the 4 weeks of the intervention. The feces sample was taken every weekend. A two-way (group × time) mixed-design ANOVA was used to examine the body parameters. Independent one-way ANOVA was used to analyze the differences between groups in baseline characteristics and different values of each parameter. Results: HDL-C level was higher in MG than in LG. In comparison to LG, MG had lower levels of total cholesterol, low-density lipoprotein cholesterol, body weight, body mass index, body fat mass and body fat percentage. However, there was no difference in muscle strength between in the four groups. The abundance of Actinobacteria was higher in LG and Erysipelotrichaceae was lower in MG and HG. Conclusion: The findings suggest that cheese could be a readily available food-borne protein supplement to enhance the beneficial effects of RT on health. It may improve body composition and lipid profile by altering the proportion of intestinal microbiota. During the 4-week RT intervention, 13.4 g of foodborne protein in the form of cheese 3 times per week was the ideal dosage.

5.
Eur J Nucl Med Mol Imaging ; 50(2): 593-601, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36222855

RESUMO

BACKGROUND: This study aimed to investigate the prognostic value of semiquantitative parameters derived from [68 Ga]Ga-fibroblast activation protein inhibitor (FAPI) PET/CT for patients with esophageal squamous cell carcinoma (ESCC) treated with definitive chemoradiotherapy. METHODS: We conducted a retrospective analysis on patients from a prospective parent study (NCT04416165). A total of 45 patients with locally advanced ESCC who underwent [68 Ga]Ga-FAPI from December 2019 to March 2021 were included. The maximum standard uptake value (SUVmax), gross tumor volume (GTV), and total lesion-FAPI (TL-FAPI) of the primary tumor were calculated from the corresponding PET/CT image. Unpaired parameters were compared using Student's t test or the Mann-Whitney U test. Paired parameters were compared using the paired t test or the Wilcoxon matched-pairs signed-rank test. Kaplan-Meier curves were generated to calculate progression-free survival (PFS) and overall survival (OS) rates, and Cox regression analysis was performed to determine which PET/CT parameters were prognostic factors for PFS and/or OS. RESULTS: Thirty-four of the 45 patients met the criteria, and the median follow-up time was 24 months (16-29 months). SUVmax-FAPI, GTVFAPI, and TL-FAPI in patients with stage T4 tumors were significantly higher than those in patients with stage T2/T3 tumors (all P < 0.01). In the univariate Cox regression analysis, T stage, N stage, GTVFAPI, and TL-FAPI were associated with PFS, and T stage, GTVFAPI, and TL-FAPI were associated with OS. Upon multivariable analysis, GTVFAPI was an independent prognostic factor for both PFS (hazard ratio (HR), 5.76; 95% confidence interval (CI), 2.13-15.57, P = 0.001) and OS (HR, 4.96; 95% CI, 2.55-18.79, P = 0.001). CONCLUSION: This pilot study revealed that [68 Ga]Ga-FAPI PET/CT may have prognostic value for patients with ESCC treated with definitive chemoradiotherapy. It may aid in personalized patient management by steering treatment modifications before therapy. Prospective studies with larger samples and longer observation periods are needed.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/terapia , Carcinoma de Células Escamosas do Esôfago/diagnóstico por imagem , Carcinoma de Células Escamosas do Esôfago/terapia , Fibroblastos/metabolismo , Fluordesoxiglucose F18/metabolismo , Radioisótopos de Gálio , Projetos Piloto , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Carga Tumoral
6.
Fam Pract ; 2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36866698

RESUMO

BACKGROUND: Integrated care has been proven to be effective among stroke survivors. However, in China, these services mainly focus on connecting the healthcare system (acute, primary medical, and skilled) at the individual level. Closer health and social care integration is a new concept. OBJECTIVE: This study aimed to compare health-related outcomes 6 months after the implementation of the 2 integrated care models. METHODS: It was a 6-month follow-up of an open, prospectively study comparing the outcomes of a model of integrated health and social care (IHSC) versus a usual integrated healthcare (IHC) model. Outcomes were measured by Short-Form Health Survey-36 (SF-36), Modified Barthel Index (MBI), and Caregiver Strain Index (CSI) at 3 and 6 months, respectively. RESULTS: There were no statistically significant differences in MBI scores between patients in the 2 models either after 3 months or at the end of intervention. The same trend was not seen in Physical Components Summary, an integral component of SF-36. Patients in IHSC model scored statistically significant higher points in Mental Components Summary, another integral part of SF-36 than patients in IHC model after 6 months. Average scores of CSI were statistically significant lower for IHSC model than for IHC model after 6 months. CONCLUSION: The findings suggest the need to improve the scales of integration and recognize the vital role played by social care services when designing or improving an integrated care for older people with stroke.

7.
Eur J Nucl Med Mol Imaging ; 49(4): 1360-1373, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34665275

RESUMO

PURPOSE: To explore the feasibility of [68Ga]Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) in patients with non-keratinizing nasopharyngeal carcinoma (NPC) and to evaluate whether [68Ga]Ga-DOTATATE PET/CT could be used for non-invasive determination of somatostatin receptor 2 (SSTR2) expression in NPC. METHODS: This prospective study included patients with NPC who underwent [68Ga]Ga-DOTATATE PET/CT between February and May 2021. The [68Ga]Ga-DOTATATE and [18F]FDG uptakes in primary and metastatic NPC lesions were calculated and compared, and the [68Ga]Ga-DOTATATE uptake between SSTR2 score groups was analysed. RESULTS: A total of 36 participants (25 patients, initial staging; 11 patients, recurrence detection) were included; 33 patients also underwent [18F]FDG PET/CT for staging/restaging as a part of their routine diagnostic workup. [68Ga]Ga-DOTATATE PET/CT showed an intense tracer uptake in primary and metastatic NPC lesions. The radiotracer uptake was higher with [68Ga]Ga-DOTATATE than with [18F]FDG PET in primary NPC lesions (SUVmax: 12.03 vs. 10.07, P = 0.048; tumour-to-brain ratio: 36.16 vs. 0.86, P < 0.001) and regional lymph node metastases (median SUVmax: 9.11 vs. 6.12, P < 0.001) and comparable in bone and visceral metastases. Importantly, most NPC lesions showed intense SSTR2 expression (85.7%), which was strongly correlated with the [68Ga]Ga-DOTATATE uptake. The SUVmax of SSTR2-negative lesions was significantly lower than that of SSTR2-positive lesions (SUVmax: 4.95 vs. 12.61, P = 0.013). CONCLUSION: [68Ga]Ga-DOTATATE PET/CT is a promising imaging modality for detecting primary and metastatic NPC, with favourable image contrast and comparable diagnostic efficacy when compared to [18F]FDG PET/CT. An intense SSTR2 expression was observed in most NPCs, and this expression was significantly correlated with the [68Ga]Ga-DOTATATE uptake.


Assuntos
Neoplasias Nasofaríngeas , Compostos Organometálicos , Fluordesoxiglucose F18 , Radioisótopos de Gálio , Humanos , Carcinoma Nasofaríngeo/diagnóstico por imagem , Neoplasias Nasofaríngeas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons , Estudos Prospectivos , Cintilografia , Compostos Radiofarmacêuticos , Receptores de Somatostatina/metabolismo
8.
Mol Pharm ; 19(10): 3640-3651, 2022 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-35917335

RESUMO

Fibroblast activation protein (FAP), a fundamental component of the tumor stroma, is overexpressed in cancer-associated fibroblasts (CAFs). As a promising theranostic probe, we evaluated whether the FAP inhibitor (FAPI) dimer (DOTA-2P[FAPI]2) is more effective than its monomeric analogs for FAP-targeted radionuclide therapy. [68Ga]Ga/[177Lu]Lu-DOTA-2P(FAPI)2 were assayed in a stability study, small-animal positron emission tomography (PET) and single-photon emission computed tomography (SPECT), biodistribution, and radionuclide therapy to comprehensively evaluate their preclinical pharmacokinetics. The pharmacokinetics of [68Ga]Ga-DOTA-2P(FAPI)2 and [177Lu]Lu-DOTA-2P(FAPI)2 were determined in FAP-positive hepatocellular carcinoma patient-derived xenografts (PDXs) and HT-1080-FAP cell-derived xenografts (CDXs). [68Ga]Ga-DOTA-2P(FAPI)2 and [177Lu]Lu-DOTA-2P(FAPI)2 were stable in phosphate-buffered saline for 4 h. The tumor retention of [68Ga]Ga-DOTA-2P(FAPI)2 was better than that of [68Ga]Ga-FAPI-46 in HT-1080-FAP CDXs, while healthy organs showed low tracer uptake and fast body clearance. In single-photon emission computed tomography, [177Lu]Lu-DOTA-2P(FAPI)2 showed a higher uptake and longer retention for tumors in both PDXs and CDXs from 1-48 h. [177Lu]Lu-DOTA-2P(FAPI)2 showed the best inhibition of tumor growth in PDXs and CDXs. DOTA-2P(FAPI)2 has increased tumor uptake and retention properties compared to FAPI-46, which significantly improves the use of FAPI-based vectors for PET imaging and radionuclide therapy. [177Lu]Lu-DOTA-2P(FAPI)2 may be safe and effective for the treatment of FAP-positive malignant tumors.


Assuntos
Fibroblastos Associados a Câncer , Neoplasias , Animais , Radioisótopos de Gálio , Humanos , Proteínas de Membrana/metabolismo , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Fosfatos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Distribuição Tecidual
9.
BMC Health Serv Res ; 22(1): 575, 2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35488231

RESUMO

BACKGROUND: In China, the majority of community care for older people is planned and offered in a few large cities. The provision of community care to the rural population is a new concept. This study aimed to assess the prevalence of willingness to receive a novel community care service that incorporates community rehabilitation among older people, and identify the possible factors influencing utilization willingness in Foshan, China. METHODS: A cross-sectional study was conducted involving 413 older people in Lishui county, China from January to March 2021. Trained staff interviewed older people using structured questionnaires. Multivariate logistic regression analysis was used to determine factors that were significantly associated with the willingness to receive this novel community care. RESULTS: The prevalence of willingness to receive community care for older people was 61.9% (n = 245) in Foshan, China. Older people who were living alone or living with spouses were about two times significantly more likely to receive community care compared to those living with children/others (OR = 2.19, 95%CI:2.44 ~ 3.19, OR = 2.015, 95%CI: 1.39 ~ 2.23, respectively). Older people who lived closer to the community care center were about two times significantly more likely to receive community care compared to those who lived far away (OR = 2.10, 95%CI: 1.61 ~ 2.41). Older people with activity of daily living disability were about three times significantly more likely to receive community care compared to those without a disability (OR = 3.13, 95%CI: 2.38 ~ 3.29). CONCLUSIONS: A majority of rural older people were willing to receive this novel community care service that includes community rehabilitation. The findings suggest the need for policies and programs to not only improve the provision of this novel community care service but also promote its uptake among older people in the study setting.


Assuntos
Pessoas com Deficiência , População Rural , Idoso , Criança , China/epidemiologia , Estudos Transversais , Humanos , Inquéritos e Questionários
10.
Plant J ; 103(5): 1735-1743, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32445267

RESUMO

Plant trichomes are large single cells that are organized in a regular pattern and play multiple biological functions. In Arabidopsis, trichome development is mainly governed by the core trichome initiation regulators, including the R2R3 type MYB transcript factor GLABRA 1 (GL1), bHLH transcript factors GLABRA 3/ENHANCER OF GLABRA 3 (GL3/EGL3), and the WD-40 repeat protein TRANSPARENT TESTA GLABRA 1 (TTG1), as well as the downstream trichome regulator GLABRA 2 (GL2). GL1, GL3/EGL3, and TTG1 can form a trimeric activation complex to activate GL2, which is required for the trichome initiation and maintenance during cell differentiation. Arabidopsis JMJ29 is a JmjC domain-containing histone demethylase belonging to the JHDM2/KDM3 group. Members of the JHDM2/KDM3 group histone demethylases are mainly responsible for the H3K9me1/2 demethylation. In the present study, we found that the trichome density on leaves and inflorescence stems is significantly decreased in jmj29 mutants. The expression of the core trichome regulators GL1, GL2, and GL3 is decreased in jmj29 mutants as well. Furthermore, JMJ29 can directly target GL3 and remove H3K9me2 on the GL3 locus. Collectively, we found that Arabidopsis JMJ29 is involved in trichome development by directly regulating GL3 expression. These results provide further insights into the molecular mechanism of epigenetic regulation in Arabidopsis trichome development.


Assuntos
Proteínas de Arabidopsis/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores Genéricos de Transcrição/fisiologia , Tricomas/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Fatores Genéricos de Transcrição/genética , Fatores Genéricos de Transcrição/metabolismo , Tricomas/metabolismo
11.
Curr Microbiol ; 78(1): 383-388, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33258058

RESUMO

A Gram-staining-negative, aerobic, non-motile, rod-shaped bacterium with degradation ability of chitin, designated strain YD-1 T, was isolated from landfill soil sample collected in Wenzhou, Zhejiang province, China. The growth of strain YD-1 T occurred optimally in the tryptone soy broth (TSB) with 1.0% NaCl at pH 7.0-8.0, 30 °C. Ubiquinone-8 (Q-8) was the predominant quinone. The polar lipids of strain YD-1 T consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, five glycolipids and four lipids. The major fatty acids were iso-C15:0 (30.7%), iso-C17:1ω9c (23.2%), iso-C11:0 (18.9%), iso-C11:0 3-OH (6.8%) and iso-C17:0 (5.9%). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain YD-1 T was affiliated to the genus Luteimonas with the highest similarity to Luteimonas marina KCTC 12327 T (97.3%), followed by Luteimonas aquatica DSM 22088 T (96.5%) and Luteimonas composti CCUG 53595 T (96.4%). The genomic DNA G + C content of strain YD-1 T was 71.8 mol%. Average nucleotide identity (ANI) and the digital DNA-DNA hybridizations (dDDH) for draft genomes between strain YD-1 T and Luteimonas marina KCTC 12327 T were 82.7% and 26.1%, respectively. On the basis of genotypic, phenotypic and chemotaxonomic data, strain YD-1 T is considered to represent a novel species to degrade chitin in the genus Luteimonas, for which the name Luteimonas wenzhouensis sp. nov. is proposed, with YD-1 T (= KCTC 72425 T = CCTCC AB 2019153 T) as the type strain.


Assuntos
Fosfolipídeos , Solo , Técnicas de Tipagem Bacteriana , China , DNA Bacteriano/genética , Ácidos Graxos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Instalações de Eliminação de Resíduos , Xanthomonadaceae
12.
Nat Mater ; 18(5): 476-481, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30833780

RESUMO

The experimental manifestation of topological effects in bulk materials is attracting enormous research interest. However, direct experimental evidence of the effective k-space monopole of the Weyl nodes has so far been lacking. Here, signatures of the singular topology of the type-II Weyl semimetal TaIrTe4 are revealed in the photoresponses, which are related to divergence of the Berry curvature. TaIrTe4 exhibits a large photoresponsivity of 130.2 mA W-1-with 4 µm excitation in an unbiased field-effect transistor at room temperature-arising from the third-order nonlinear optical response, approaching the performance of commercial low-temperature detectors. In addition, the circularly polarized galvanic response is enhanced at 4 µm, possibly due to the same Berry curvature singularity enhancement. Considering the optical selection rule of chiral Weyl cones, this may open the door for studying and controlling the chiral polarization of Weyl fermions with an electric field in addition to the optical helicities.

14.
Nucleic Acids Res ; 46(20): 10669-10681, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30124938

RESUMO

In Arabidopsis, the circadian clock central oscillator genes are important cellular components to generate and maintain circadian rhythms. There is a negative feedback loop between the morning expressed CCA1 (CIRCADIAN CLOCK ASSOCIATED 1)/LHY (LATE ELONGATED HYPOCOTYL) and evening expressed TOC1 (TIMING OF CAB EXPRESSION 1). CCA1 and LHY negatively regulate the expression of TOC1, while TOC1 also binds to the promoters of CCA1 and LHY to repress their expression. Recent studies indicate that histone modifications play an important role in the regulation of the central oscillators. However, the regulatory relationship between histone modifications and the circadian clock genes remains largely unclear. In this study, we found that the Lysine-Specific Demethylase 1 (LSD1)-like histone demethylases, LDL1 and LDL2, can interact with CCA1/LHY to repress the expression of TOC1. ChIP-Seq analysis indicated that LDL1 targets a subset of genes involved in the circadian rhythm regulated by CCA1. Furthermore, LDL1 and LDL2 interact with the histone deacetylase HDA6 and co-regulate TOC1 by histone demetylation and deacetylaion. These results provide new insight into the molecular mechanism of how the circadian clock central oscillator genes are regulated through histone modifications.


Assuntos
Proteínas de Arabidopsis/genética , Relógios Circadianos/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/genética , Histona Desmetilases/genética , Fatores de Transcrição/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , Perfilação da Expressão Gênica , Código das Histonas/genética , Histona Desacetilases/metabolismo , Histona Desmetilases/metabolismo , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Ligação Proteica , Fatores de Transcrição/metabolismo
15.
Nano Lett ; 19(3): 2148-2153, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30835131

RESUMO

Emerging two-dimensional (2D) semiconducting materials serve as promising alternatives for next-generation digital electronics and optoelectronics. However, large-scale 2D semiconductor films synthesized so far are typically polycrystalline with defective grain boundaries that could degrade their performance. Here, for the first time, wafer-size growth of a single-crystal Bi2O2Se film, which is a novel air-stable 2D semiconductor with high mobility, was achieved on insulating perovskite oxide substrates [SrTiO3, LaAlO3, (La, Sr)(Al, Ta)O3]. The layered Bi2O2Se epilayer exhibits perfect lattice matching and strong interaction with perovskite oxide substrates, which enable unidirectional alignment and seamless mergence of multiple seeds into single-crystal continuous films free of detrimental grain boundaries. The single-crystal Bi2O2Se thin films show excellent spatial homogeneity over the entire wafer and allow for the batch fabrication of high-performance field-effect devices with high mobilities of ∼150 cm2 V-1 s-1 at room temperature, excellent switching behavior with large on/off ratio of >105, and high drive current of ∼45 µA µm-1 at a channel length of ∼5 µm. Our work makes a step toward the practical applications of high-mobility semiconducting 2D layered materials and provides an alternative platform of oxide heterostructure to investigate novel physical phenomena.

16.
Protein Expr Purif ; 164: 105481, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31470096

RESUMO

The lamC gene encoding a novel ß-(1,3)-glucanase was cloned from Corallococcus sp. EGB and successfully expressed in the industrial yeast Pichia pastoris. The mature protein without the initial 26 residues of signal peptide, designated LamC27, was found to be composed of fascin-like module and laminarinase-like catalytic module. The purified recombinant enzyme (rLamC27) with a calculated molecular mass of 45.3 kDa displays activities toward a broad range of ß-linked polysaccharides, including laminarin, curdlan, pachyman, lichenan, and CMC. Enzymological characterization showed that rLamC27 performes its optimal activity under the condition of 45 °C and pH 7.0, respectively, and preferentially catalyzes the hydrolysis of glucans with a ß-1,3-linkage, which is similar to the LamC previously expressed in E. coli. TherLamC27 enzyme was activated by Mn2+ and Ba2+, while it was inhibited by Cu2+, Zn2+, and Co2+. Moreover, rLamC27 was strongly inhibited by 10 mM EDTA with 7.5% of its original activity remiaining, and weakly by SDS and Triton X-100. In antifungal assay, rLamC27 was conformed to possess lytic and antifungal activity against rice blast fungus. Specifically, a significant decrease germ tube and appressorium formation ratios from 94% to 59% and 97%-51%, respectively, were observed following exposure to rLamC27. H2DCFDA and CFW staining further demonstrated that the fungistasis capability of rLamC27 could be contributed by its ability to hydrolyze components of the cell wall. All these favorable properties indicate a promising potential for using rLamC27 as a biological antifungal agent in areas such as plant protection and food preservation.


Assuntos
Endo-1,3(4)-beta-Glucanase/metabolismo , Myxococcales/enzimologia , Clonagem Molecular , Endo-1,3(4)-beta-Glucanase/genética , Endo-1,3(4)-beta-Glucanase/farmacologia , Fungicidas Industriais/metabolismo , Fungicidas Industriais/farmacologia , Expressão Gênica , Metais/metabolismo , Myxococcales/genética , Myxococcales/metabolismo , Oryza/microbiologia , Pichia/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Especificidade por Substrato
17.
Appl Microbiol Biotechnol ; 103(8): 3289-3295, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30850873

RESUMO

Chitinases are hydrolases that catalyze the cleavage of the ß-1,4-O-glycosidic linkages in chitin, a polysaccharide abundantly found in nature. Although numerous chitinolytic enzymes have been studied in detail, relatively little is known about chitinases capable of broad specificity. Broad-specificity chitinases are a sort of novel chitinases possessing two or three different catalytic activities among exochitinase, endochitinase, and N-acetylglucosaminidase. In the light of the difference of module composition and catalytic mechanism, the broad-specificity chitinases included two broad categories, broad-specificity chitinases with a single catalytic domain or multi-catalytic domains. This broad-specificity chitinases have great potential in chitin conversion. In this review, we summarize all reported cases of broad-specificity chitinases and provide an overview of the recent findings on their origin, characterization, catalytic mechanism, and potential application. Moreover, in-depth study into these chitinases could contribute to our understanding of other broad-specificity enzymes which may have some benefits on progress of biotechnology.


Assuntos
Quitina/metabolismo , Quitinases/metabolismo , Acetilglucosaminidase/metabolismo , Biotecnologia , Catálise , Domínio Catalítico , Quitinases/química , Hexosaminidases/química , Hexosaminidases/metabolismo , Especificidade por Substrato
18.
Foodborne Pathog Dis ; 13(4): 171-6, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27074376

RESUMO

The distribution of 18 staphylococcal enterotoxin (SE) or SE-like (SEl) genes in Staphylococcus aureus strains from different sources in east China was investigated. Among all 496 S. aureus strains, 291 strains carried one or more SE genes. The more frequently occurred genes were sea, seb, seg, selk, sell, selm, selo, and seq; the less frequent occurred genes were sec, selj, and ser. The classic SE genes and the enterotoxin gene cluster (egc) (seg, sei, selm, seln, selo, and/or selu) accounted for 25.67% and 61.68% of all detected genes, respectively. There were three gene clusters (egc, sea-sek-seq, and sed-sej-ser), of which the egc cluster was the important one that could generate novel complexes, and the sea-sek-seq cluster was a close relative to the hospital-acquired methicillin-resistant S. aureus. The SE gene distributions were different among strains of different sources and formed diverse toxin gene profiles. The human- and foodborne-origin strains harbored classic and novel SE and SEl genes, whereas animal-origin strains harbored egc and other novel SE and SEl genes mainly. The foodborne- and human-origin strains were the main dangerous factors of classic staphylococcal foodborne poisoning, whereas the strains (especially from animals) that carried egc and other novel genes mainly should be new potential dangerous factors for food safety.


Assuntos
Proteínas de Bactérias/genética , Enterotoxinas/genética , Genes Bacterianos , Staphylococcus aureus/genética , Fatores de Virulência/genética , Animais , Animais Domésticos/microbiologia , Proteínas de Bactérias/metabolismo , China , Enterotoxinas/metabolismo , Inspeção de Alimentos , Microbiologia de Alimentos , Hospitais Veterinários , Humanos , Leite/microbiologia , Tipagem Molecular/veterinária , Família Multigênica , Intoxicação Alimentar Estafilocócica/microbiologia , Intoxicação Alimentar Estafilocócica/veterinária , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/classificação , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/metabolismo , Centros de Atenção Terciária , Fatores de Virulência/metabolismo
19.
Ultrason Sonochem ; 102: 106736, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38109798

RESUMO

Sludge dewatering plays a critical role in the efficient and cost-effective management of wastewater treatment plants. Ultrasonic treatment has emerged as a promising technique for improving dewatering processes. This study aims to evaluate the impact of ultrasonic treatment on sludge dewatering characteristics. A series of experiments were conducted to evaluate the dewatering characteristics of sludge under ultrasonic treatment. Experimental data was collected, and the effects of ultrasonic parameters on dewatering efficiency were analyzed. Ultrasound has the capacity to disintegrate sludge flocs, liberate tightly bound water, and enhance sludge dewatering capabilities. The application of ultrasound leads to the breakdown of sludge flocs, which facilitates a substantial amount of organic acids or carbonates. This, in turn, modifies the pH value of the sludge. Additionally, ultrasound induces instantaneous high temperature and pressure within the liquid phase, consequently elevating the temperature of the sludge slurry. Optimum ultrasound energy density and duration of ultrasound treatment exist. For the sludge samples analyzed in this investigation, it was determined that the optimal ultrasonic energy density is 9.8 W, while the optimal duration of ultrasound treatment is 30 s. Excessively escalating the sound energy density or prolonging the duration of ultrasound may yield unfavorable outcomes in terms of sludge dewatering effectiveness. To enhance sludge dewatering, it is crucial to select appropriate ultrasonic energy density and duration of ultrasonic treatment. This study demonstrates the positive impact of ultrasonic treatment on the dewatering characteristics of sludge. The findings provide valuable insights into the potential of ultrasonic technology for enhancing sludge dewatering.

20.
Adv Mater ; 36(23): e2313219, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38597361

RESUMO

The development of novel materials and structures for efficient second-order nonlinear micro/nano devices remains a significant challenge. In this study, the remarkable enhancement of second-harmonic generation (SHG) and cascaded sum frequency generation in whispering gallery mode microspheres made of surface-crystallized glass with a 6-µm Ba2TiSi2O8 crystal layer are demonstrated. Attributed to the core-shell design, the Ba2TiSi2O8 located on the surface can be efficiently coupled with whispering gallery modes, resulting in a highly efficient micron-scale cavity-enhanced second-order optical nonlinearity. Greatly enhanced SHG of the microcavity is observed, which is up to 80 times stronger than that of a non-resonant sample. Furthermore, owing to the wavelength non-selectivity of random quasi-phase matching, ultra-wideband SHG with a strong response ranging from 860 to 1600 nm and high-contrast polarization characteristics is demonstrated. The glass-ceramic-based microsphere cavity also boosts the cascading optical nonlinearity, manifested by a two-magnitude enhancement of cascaded sum frequency generation. This work delineates an efficient strategy for boosting nonlinear optical response in glass ceramics, which will open up new opportunities for applications in photonics and optical communications.

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