RESUMO
PURPOSE: The beneficial effects of family resilience and meaning in life on patients are established, but limited is known for the effect of perceived social support. We aim to investigate the impact of family resilience on the meaning of life among Chinese patients with breast cancer (BC) and to further detect whether perceived social support mediated this association. METHODS: From February to June 2022, we conducted this cross-sectional study with 276 women who were diagnosed with BC in a tertial hospital in Guangdong province, China. The Chinese version of Meaning in Life Scale (C-MiLS) was used to measure the meaning in life. The Chinese version of the family resilience assessment scale (C-FRAS) and the perceived social support scale (PSSS) were adopted to obtain the family resilience and perceived social support, respectively. The mediating effect of perceived spousal support was estimated using the bootstrapped confidence interval (CI) via IBM SPSS AMOS 22.0. RESULTS: The mean scores were 60.79 ± 11.63 for meaning in life, 82.08 ± 11.48 for family resilience, and 62.72 ± 12.19 for perceived social support, respectively. Our results indicated the positive correlations of meaning in life with family resilience (ß = 0.822, P < 0.05) and perceived social support (ß = 0.886, P < 0.05). The perceived social support exerted the mediating effect in the relationship between family resilience and meaning in life (ß = 0.368 [95%CI, 0.274, 0.450], P < 0.001), accounting for 54.6% of the variance in meaning in life. CONCLUSIONS: Our findings highlight that family resilience and perceived social support should be enhanced for BC patients to improve their meaning in life. In particular, the association between family resilience and meaning in life was positively mediated by perceived social support. Thus, interventions for improving family resilience and perceived social support might be useful in easing psychological distress and improving meaning in life in individuals with BC.
Assuntos
Neoplasias da Mama , Resiliência Psicológica , Apoio Social , Humanos , Feminino , Estudos Transversais , Neoplasias da Mama/psicologia , Pessoa de Meia-Idade , Adulto , China , Família/psicologia , Inquéritos e Questionários , Idoso , Qualidade de Vida/psicologia , Adaptação PsicológicaRESUMO
Cancer incidence escalates exponentially with advancing age; however, the underlying mechanism remains unclear. In this study, we build a chronological molecular clock at single-cell transcription level with a mammary stem cell-enriched population to depict physiological aging dynamics in female mice. We find that the mammary aging process is asynchronous and progressive, initiated by an early senescence program, succeeded by an entropic late senescence program with elevated cancer associated pathways, vulnerable to cancer predisposition. The transition towards senescence program is governed by a stem cell factor Bcl11b, loss of which accelerates mammary ageing with enhanced DMBA-induced tumor formation. We have identified a drug TPCA-1 that can rejuvenate mammary cells and significantly reduce aging-related cancer incidence. Our findings establish a molecular portrait of progressive mammary cell aging and elucidate the transcriptional regulatory network bridging mammary aging and cancer predisposition, which has potential implications for the management of cancer prevalence in the aged.
Assuntos
Envelhecimento , Neoplasias da Mama , Senescência Celular , Feminino , Animais , Camundongos , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/genética , Humanos , Glândulas Mamárias Animais/patologia , Glândulas Mamárias Animais/metabolismo , Células-Tronco/metabolismoRESUMO
AIMS: Neuroblastoma (NB) is the most common extracranial solid tumor in children, with a 5-year survival rate of <50% in high-risk patients. MYCN amplification is an important factor that influences the survival rate of high-risk patients. Our results indicated MYCN regulates the expression of SESN1. Therefore, this study aimed to investigate the role and mechanisms of SESN1 in NB. METHODS: siRNAs or overexpression plasmids were used to change MYCN, SESN1, or MyD88's expression. The role of SESN1 in NB cell proliferation, migration, and invasion was elucidated. Xenograft mice models were built to evaluate SESN1's effect in vivo. The correlation between SESN1 expression and clinicopathological data of patients with NB was analyzed. RNA-Seq was done to explore SESN1's downstream targets. RESULTS: SESN1 was regulated by MYCN in NB cells. Knockdown SESN1 promoted NB cell proliferation, cell migration, and cell invasion, and overexpressing SESN1 had opposite functions. Knockdown SESN1 promoted tumor growth and shortened tumor-bearing mice survival time. Low expression of SESN1 had a positive correlation with poor prognosis in patients with NB. RNA-Seq showed that Toll-like receptor (TLR) signaling pathway, and PD-L1 expression and PD-1 checkpoint pathway in cancer were potential downstream targets of SESN1. Knockdown MyD88 or TLRs inhibitor HCQ reversed the effect of knockdown SESN1 in NB cells. High expression of SESN1 was significantly associated with a higher immune score and indicated an active immune microenvironment for patients with NB. CONCLUSIONS: SESN1 functions as a new tumor suppressor gene via TLR signaling pathway in NB.
Assuntos
Fator 88 de Diferenciação Mieloide , Neuroblastoma , Criança , Humanos , Animais , Camundongos , Proteína Proto-Oncogênica N-Myc/genética , Proteína Proto-Oncogênica N-Myc/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Fatores de Transcrição/genética , Transdução de Sinais/genética , Neuroblastoma/patologia , Genes Supressores de Tumor , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Microambiente Tumoral , Sestrinas/genética , Sestrinas/metabolismoRESUMO
Bacterial AraC is a transcription factor family that initiates transcription by recruiting RNA polymerase to the promoter and directly regulating various bacterial phenotypes. It also directly regulates various bacterial phenotypes. However, how this transcription factor regulates bacterial virulence and affects host immunity is still largely unknown. In this study, deleting the orf02889 (AraC-like transcription factor) gene in virulent Aeromonas hydrophila LP-2 affected several important phenotypes, such as increasing biofilm formation and siderophore production abilities. Moreover, Δorf02889 also significantly decreased the virulence of A. hydrophila and has promising attenuated vaccine potential. To better understand the effects of orf02889 on biological functions, a data independent acquisition (DIA)-based quantitative proteomics method was performed to compare the differentially expressed proteins between Δorf02889 and the wild-type strain in extracellular fractions. The following bioinformatics analysis suggested that ORF02889 may regulate various metabolic pathways, such as quorum sensing and ATP binding cassette (ABC) transporter metabolism. Moreover, 10 selected genes from the top 10 decreasing abundances in proteomics data were deleted, and their virulence to zebrafish was evaluated, respectively. The results showed that ΔcorC, Δorf00906, and Δorf04042 significantly reduced bacterial virulence. Finally, the following chromatin immunoprecipitation and polymerase chain reaction (ChIP-PCR) assay validated that the promoter of corC was directly regulated by ORF02889. Overall, these results provide insight into the biological function of ORF02889 and demonstrate its inherent regulatory mechanism for the virulence of A. hydrophila.
Assuntos
Aeromonas hydrophila , Peixe-Zebra , Animais , Virulência/genética , Peixe-Zebra/metabolismo , Proteínas de Bactérias/metabolismo , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Traditional Chinese Medicine (TCM) nurse-led clinics (NLC) is an innovative working model in China, representing the specialization and extension of nurses' role. However, as a pioneer in TCM nursing, this new model of working is facing both opportunities and challenges because it is known little about the operational status of NLCs. AIMS: To explore the experiences of nurses who work in NLC in TCM hospitals. MATERIALS & METHODS: A focused ethnographic study was conducted in three TCM hospitals affiliated with Guangzhou University of Chinese Medicine. We interviewed eleven nurses in those hospitals and observed seven of them working with patients. We used snowball sampling for data collection including interview, non-participant observation and documents from medical records. All the data were processed as following steps: (a) coding for descriptive labels; (b) sorting for patterns; (c) identifying outliers or negative cases; (d) generalizing with construction and theories and (e) noting reflective remarks. RESULTS: Nurse-led clinics help nurses develop their skills and knowledge that are highly recognized by public since they meet the growing needs of patients and also relieve the workload of physicians in the hospitals. However, lack of specialization is still a major challenge in NLCs due to insufficiency of full-time staff with specialized education, nurse-led practice without standardized guidelines, restrictions on prescription right of nurses, and also inadequate support from hospitals. DISCUSSIONS: As a revolutionary innovation of working model for nurses in TCM hospitals, NLCs could improve quality of care and lead to a comprehensive promotion of nursing career. However, there are several challenges on providing high quality care for patients whilst improving educational development of nurses. This study suggests that nurses, hospital administration and the government should cooperate with each other to develop standard nursing programs for NLCs. CONCLUSIONS: It is imperative to identify nursing roles, collect available resources, and develop supportive policies and training programs to enhance the quality of NLCs.
Assuntos
Enfermeiras e Enfermeiros , Padrões de Prática em Enfermagem , Humanos , Medicina Tradicional Chinesa , Hospitais , Antropologia CulturalRESUMO
In this paper, we investigated the quarantine hotel (QH) booking intention (BI) of potential consumers from a corporate social responsibility (CSR) perspective. Mixed methods were adopted to explore the formation mechanisms of QH BI of potential consumers when the COVID-19 pandemic recedes. In Study 1, we constructed a theoretical model of QH BI of potential consumers based on grounded theory and put forward research propositions. In Study 2, we tested the robustness of the model and identified the mediating effect through two situational experiments. The research results showed that: (1) Potential customers are more willing to book QHs than normal hotels (NHs). (2) Multiple mediating mechanisms are involved in the effect of the operation as a quarantine facility on BI of potential consumers, including "QH-corporate social responsibility (CSR)-customer trust (CT)-BI" and "QH-CSR-customer gratitude (CG)-BI." This research not only has theoretical significance for deepening and expanding social exchange theory and hotel CSR theories but also provides guidance for the participation of the hotel industry in the prevention and control of the COVID-19 pandemic and hotel marketing after the pandemic ends.
RESUMO
The existing studies have analyzed the advertising effects of metaphorical advertisements and straightforward adverts in traditional advertising media. However, their advertising effects on social media are still unclear. To address this issue, this study uses eye-tracking and questionnaires to examine two types of social media tourism advertising-metaphorical and straightforward in posts with both high and low popularity. This within-subject (n = 55) experiment was designed to examine the effects of social media tourism advertising types on visual attention and tourism intention and to identify the moderating role of post popularity based on the elaboration likelihood model (ELM). We found that advertising types had no significant effect on visual attention, but metaphorical advertisements increased tourism intention compared with straightforward adverts. Furthermore, we found that the level of post popularity moderated the effect of advertising types on visual attention. Specifically, metaphorical adverts in highly popular posts attracted more visual attention in the advertising text area and in the whole advert. Straightforward adverts in posts with low popularity attracted more visual attention in the advertising text area. This research advances the current literature by exploring the effects of social media tourism advertising types and has implications for managers deciding on strategies for social media tourism marketing.
RESUMO
By improving the previous method of CUT&RUN, we developed D-CUT&RUN (DSP fixed CUT&RUN) for under-expressed transcription factor. High-quality data could be obtained for low expressed transcription factors using chemical crosslinkers (DSP) and reducing agent (DTT). We applied our D-CUT&RUN to detection of Bcl11b and Mycn binding sites in mammary epithelial progenitor cells. Pathway enrichment analysis results of Bcl11b target genes showed that Bcl11b was a regulatory factor involved in breast cancer and it could negatively regulate Wnt signaling pathway. Furthermore, the role of Bcl11b in breast cancer was mediated by catabolic process and stress-related pathway. Our research suggested that D-CUT&RUN could be used for low abundance transcription factor binding sites detection and Bcl11b could be a target for breast cancer treatment in the future.
Assuntos
Neoplasias da Mama , Fatores de Transcrição , Neoplasias da Mama/genética , Feminino , Humanos , Proteínas Repressoras/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Via de Sinalização WntRESUMO
Background: Fatigue is a common symptom in adults that may cause physical and psychological problems and reduce quality of life. Aromatherapy could possibly provide relief for those suffering from fatigue. Here, we evaluated the effect of aromatherapy on fatigue in adults. Methods: We searched the PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Chinese Biomedical Literature, SinoMed, Wanfang, and Chinese Scientific Journal Database databases for randomized controlled trials of aromatherapy treatment for fatigue in adults from their inception to June 2021. Two reviewers searched independently, extracted the characteristics of the studies, and assessed the risk of bias using the Cochrane risk-of-bias tool and Stata v. 14.0. Results: Nineteen studies were included in this systematic review. Aromatherapy had a significant effect on fatigue (standardized mean difference -0.64, 95% confidence interval-1.14, -0.15, I2 94.4%, P < 0.001). Subgroup analysis according to aromatic type, substance, frequency, treatment duration, intervention, outcomes measurement, and population type showed that aromatherapy had a significantly greater effect in the intervention group, compared to the control group. Funnel plots and Egger's test indicated no significant publication bias. Conclusion: Our results suggest that aromatherapy ameliorates fatigue in adults who suffer from chronic diseases. A rigorous intervention program and larger randomized controlled trials are needed.
RESUMO
In this study, the inhibitory effect and mechanism of omeprazole on α-glucosidase and nonenzymatic glycation were investigated in vitro by using multi-spectroscopic methods and molecular docking. Enzyme kinetic results showed that omeprazole inhibited α-glucosidase in a reversible and noncompetitive manner (IC50= 0.595 ± 0.003 mM). The results from fluorescence quenching and thermomechanical analyses signified that omeprazole reduced the fluorescence intensity of α-glucosidase by forming an omeprazole-α-glucosidase complex primarily driven by hydrogen bonds. Molecular docking further confirmed that hydrogen bonds and hydrophobic forces were the major driving forces for omeprazole binding to α-glucosidase. The nonenzymatic glycation assays revealed that omeprazole had a moderate inhibition against the formation of fructosamine, dicarbonyl compounds, and advanced glycation end products (AGEs). This study provides a new inhibitor of both α-glucosidase and nonenzymatic glycation and provides a practicable candidate for treating diabetes and its complications.
Assuntos
Inibidores de Glicosídeo Hidrolases , alfa-Glucosidases , Inibidores de Glicosídeo Hidrolases/farmacologia , Glicosilação , Cinética , Simulação de Acoplamento Molecular , Omeprazol/farmacologia , alfa-Glucosidases/metabolismoRESUMO
BACKGROUND: Coronavirus disease 2019 (COVID-19) causes psychological distress and can have a negative impact on the general mental health and rehabilitation in affected patients under currently implemented isolation guidelines. Auricular point pressure (APP) as well-established technique in traditional Chinese medicine may help to relieve sleep disturbance and anxiety in COVID-19 patients. METHODS: During the early phase of the epidemic/pandemic, patients were enrolled in this study (02/2020 until 03/2020 n = 84). They were strictly isolated on specific wards at the Hubei Provincial Hospital of Integrated Chinese and Western Medicine in Hubei. The retrospective cohort study design included two groups. Group A patients were treated with an auricular point pressure (APP) in addition to standard intensive care medicine while Group B participants (No-APP) received routine nursing measures alone. Treatment outcome was measured using the St. Mary's Hospital Sleep Questionnaire (SMH) Score and the 7-Item Generalized Anxiety Disorder Scale (GAD-7). Both scores were measured in each patient at baseline and on the discharge day. RESULTS: The SMH score and sleep status changed in APP patients at the end of the treatment period when compared with No-APP patients (P < 0.01). APP-treated patients demonstrated lower GAD-7 scores than No-APP controls (P < 0.01). Further, no significant differences in safety or adverse events between the APP and No-APP groups were observed. CONCLUSION: The results from our snapshot study during the early phase of the SARS-CoV-2 epidemic/pandemic suggest that auricular point pressure could be a simple and effective tool to relieve insomnia and situational anxiety in hospitalized patients suffering from COVID-19 and kept under disconcerting conditions of isolation.
RESUMO
In this study, 5-methoxy-2-mercaptobenzimidazole (5-M-2-MB) was confirmed as an efficient tyrosinase inhibitor by methods of enzyme kinetic, fluorescence quenching, ANS-binding, thermodynamics, energy transfer, and molecular docking in combination. The results proved that 5-M-2-MB significantly inhibited the tyrosinase (IC50 = 60 ± 2 nM) in a reversible and competitive way with the Ki value of 80 ± 1 nM. It quenched the intrinsic fluorescence of tyrosinase through a static mechanism, and caused conformational change of the enzyme by increasing the hydrophobic region. Moreover, this compound could bind to tyrosinase and form 5-M-2-MB-tyrosinase complex by hydrogen bond and hydrophobic interaction. The interactions were generated between 5-M-2-MB and specific amino acid residues (Trp-358, Thr-308, Glu-356, and Asp-357) located on the A chain of tyrosinase. Therefore, this study would offer a theoretical foundation for developing the new tyrosinase inhibitor.
Assuntos
Benzimidazóis/química , Inibidores Enzimáticos/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Benzimidazóis/farmacologia , Inibidores Enzimáticos/farmacologia , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Simulação de Acoplamento Molecular , TermodinâmicaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Constipation is a functional gastrointestinal disorder and one of the most prevalent conditions encountered in primary care settings. Rhubarb navel dressings have been used for more than 2,000 years in Chinese medicine to treat constipation. However, the effect of topical rhubarb administration has still not been well recognized and this strategy is not yet established as an evidence-based approach. AIM OF THE STUDY: In this study, we performed a prospective multicentric randomized controlled trial to evaluate the efficacy and safety of rhubarb navel plasters for patients with chronic constipation. MATERIALS AND METHODS: A total of 374 patients from six teaching hospitals were prospectively included between 09/2016 and 10/2017 in the study based on Rome III criteria. All participants were randomly assigned (1:1) into verum/placebo group and given either Rheum officinale rhubarb powder or a placebo flour stick on the navel for 6 h/day/8 days. Primary outcome measures were the Cleveland Constipation Score (CCS) for the feces condition and Bristol Stool Scale (BSS) for stool consistency and 24 h defecation frequency. RESULTS: The groups demonstrated no statistical differences in demographic data, clinical diagnoses and concomitant medication at baseline. In patients treated with the verum CCS was 5.61 (day 8, 95% CI 5.15-6.07) compared to 8.62 (95% CI 8.07-9.18) in placebo-treated controls (P < 0.001). The mean change of CCS at the end of treatment (day 8 versus [vs] day 0) was 6.04 in verum-treated vs 2.73 in placebo-treated controls (P < 0.001). Also 24 h defecation frequency (BSS) showed superior results (day 5: 0.84 vs 0.62, 95% CI 0.67-0.80, P < 0.001; day 6: 0.82 vs 0.60, 95% CI 0.64-0.78, P < 0.01 and day 8: 0.82 vs 0.60, 95% CI 0.64-0.78, P < 0.01) and better BSS type classification during treatment than controls (P < 0.05). No significant differences in adverse events between both groups became obvious. CONCLUSION: Rhubarb navel plaster administration over an 8-day-treatment period resulted in significantly improved bowel function as demonstrated by the CCS, 24 h defecating frequency and BSS. Our results suggest that rhubarb navel plasters represent a feasible, safe and efficient application route for the treatment of patients suffering from chronic constipation.
Assuntos
Constipação Intestinal/diagnóstico , Constipação Intestinal/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Extratos Vegetais/administração & dosagem , Rheum , Administração Tópica , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Extratos Vegetais/isolamento & purificação , Estudos Prospectivos , Resultado do TratamentoRESUMO
The subtropical forest transition zone in southern China is a typical transition zone with high coverage and diverse vegetation. Projected climate change will affect physiological processes of trees, which would consequently alter the forest aboveground biomass (AGB) and composition at broad spatial scales. However, spatially heterogeneous responses may also be shaped by climate change, succession, and harvesting in different forest habitats. The objectives of this study were to assess the changes in subtropical forest AGB and composition in response to climate change, while comparing the responses of two similar forest landscapes: Taihe County (TH) and Longnan County (LN). We used a loose-coupling of PnET-II with LANDIS-II to simulate changes in forest AGB and composition under climate change scenarios (Current climate, RCP2.6, RCP4.5, RCP6.0, and RCP8.5) with harvest disturbances. Our simulation results demonstrated that forest AGB and composition were significantly affected by climate change in both landscapes. Changes in forest AGB was mostly driven by succession and harvest, but climate change also greatly contribute to the variation in AGB of deciduous broad-leaved forests (DBF), and coniferous forests (CF). Moreover, a larger area of LN experienced biomass reduction compared to TH, specifically under the RCP8.5 scenario. Given our estimates of the response in forest AGB and composition under climate change scenarios across different periods, we recommend that the regional forest management should be localized and should consider the effects of climate change through time in their planning schemes.
Assuntos
Mudança Climática , Florestas , Biomassa , China , ÁrvoresRESUMO
BACKGROUND: Cardiovascular disease has caused heavy health care burdens in many countries, and hypertension (HTN) is a well-known independent cardiovascular risk factor. OBJECTIVE: To assess the efficacy of empowerment strategies that affect systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), quality of life, and self-management behaviours for patients with hypertension. METHODS: A literature search of the Cochrane Library, PubMed, MEDLINE, Embase, Web of Science, and several Chinese medical databases was performed. Study screening, quality assessment, data extraction, and meta-analysis were conducted according to Cochrane standards. RESULTS: Eleven randomised controlled trials with 988 subjects were identified. Relative to control groups, the empowerment strategies showed significant decreases in SBP (the mean difference [MD]â¯=â¯9.46, 95 % confidence interval [CI]â¯=â¯6.36-12.55, pâ¯<⯠0.00001) and DBP (MD = 6.68, 95 % CI = 3.07-10.29, pâ¯=⯠0.0003). However, no significant difference was found in BMI (p = 0.05). Subgroup analysis showed significant differences in the improvement of both SBP and DBP among the various groups, regardless of the duration and type of interventions. DISCUSSION: Empowerment strategies can decrease both SBP and DBP in hypertension patients. However, its influence on patients' BMI, quality of life, and self-management behaviour remains unclear. PRACTICAL VALUE: Empowerment strategies are useful for controlling the blood pressure of hypertension patients.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Empoderamento , Hipertensão/terapia , Qualidade de Vida , Índice de Massa Corporal , Humanos , Hipertensão/psicologia , AutogestãoRESUMO
α-Glucosidase is a critical enzyme associated with diabetes mellitus, and the inhibitors of the enzyme play important roles in the treatment of the disease. In this study, the inhibitory effect and mechanism of rifampicin on α-glucosidase were investigated by multispectroscopic methods along with molecular docking technique. The results showed that rifampicin inhibited α-glucosidase activity prominently (IC50â¯=â¯135⯱â¯1.2⯵M) in a reversible and competitive-type manner. The fluorescence intensity of α-glucosidase was quenched by rifampicin through forming rifampicin-α-glucosidase complex in a static procedure. And the formation of the rifampicin-α-glucosidase complex was driven spontaneously by hydrophobic forces and hydrogen bonds. The results obtained from molecular docking further indicated that hydrophobic forces were formed between rifampicin and amino acid residues Phe 173, Pro151, and hydrogen bonds were generated by the interactions of rifampicin with residues Ser 180, Asn 414, Gly160, and Gly161 of α-glucosidase. Moreover, it was found that the binding of rifampicin to α-glucosidase could alter the conformation of the enzyme to make it steady, and the binding distance was estimated to be 1.02â¯nm. Therefore, this study confirmed a novel α-glucosidase inhibitor and possibly contributed to the improvement of newfangled anti-diabetic agent.
Assuntos
Inibidores de Glicosídeo Hidrolases/metabolismo , Inibidores de Glicosídeo Hidrolases/farmacologia , Simulação de Acoplamento Molecular , Rifampina/metabolismo , Rifampina/farmacologia , alfa-Glucosidases/metabolismo , Sítios de Ligação , Transferência de Energia , Cinética , Conformação Proteica , Análise Espectral , Termodinâmica , alfa-Glucosidases/químicaRESUMO
Soil stores a substantial proportion of carbon (C), making it the greatest terrestrial C pool and pivotal to stabilizing the global climate system. Rainfall amounts and regimes have been changing in many places, but effects of precipitation changes on soil organic C (SOC) stabilization are not completely understood. Considerable attention has been focused on the consequences of changes in rainfall amounts, with rainfall regimes having been less studied. This study was conducted in a tropical climax forest to clarify the effects of rainfall changes on SOC fractions, with permanganate oxidation and density fractionations employed to divide the labile and non-labile SOC fractions. Two rainfall manipulation treatments, i.e., increased rainfall frequency with the total rainfall amount unchanged (IRF) and decreased rainfall amount by 50% with rainfall frequency unaltered (DRA), were conducted for two years, with ambient rainfall (AR) as the control. As a result, the IRF treatment increased the SOC concentration that mainly originated from increases in the non-labile SOC content. Relative to the AR control, the DRA treatment did not change the total SOC concentration although the labile SOC concentration increased. This typically is due to a small proportion of the labile fraction to the total SOC content. Our results suggest that this water-rich mature forest is resistant to rainfall amount changes to a great extent (e.g., decrease of 50% as in the present study) from the SOC stabilization perspective, while changes in rainfall frequency could exert more notable effects.
Assuntos
Carbono/análise , Monitoramento Ambiental , Florestas , Solo/química , Tempo (Meteorologia) , ClimaRESUMO
Death associated protein kinase 1 (DAPK1) is a notable serine/threonine kinase involved in the regulation of multiple cellular pathways, including apoptosis and autophagy. Although DAPK1 is usually considered to be a tumor suppressor, it was previously reported to promote the viability of p53 mutant cancer cell lines and possess physiological oncogenic functions in breast cancer. However, the ability of endogenous DAPK1 to suppress breast cancer cell mobility has not been assessed. In the present study, the prognostic function of DAPK1 in a Chinese patient cohort was evaluated, and no significant association was observed between DAPK1 expression and patient survival or lymph node metastasis. In order to investigate the physiological function of endogenous DAPK1, stable inducible DAPK1 knockdown MCF7 and MDA-MB-231 cell lines were established. Consistent with previous studies, endogenous DAPK1 only regulated cell viability in p53 mutant MDA-MB-231 cells. However, knockdown of DAPK1 did not significantly affect cell motility of either MCF7 or MDA-MB-231 cells. Altogether, these results further explored the function of endogenous DAPK1 in breast cancer and may shed light in understanding the molecular signaling pathways regulating the physiological function of DAPK1.
RESUMO
Omeprazole was first evaluated for its antityrosinase activity and preservation of fresh-cut apples. The results obtained from enzymic analyses showed that the omeprazole inhibited tyrosinase activity (IC50â¯=â¯40⯱â¯1.2⯵M) with a reversible and competitive mechanism. Fluorescence quenching assays demonstrated that the interaction between omeprazole and tyrosinase was driven by hydrophobic forces and hydrogen bonds in a static procedure. Molecular docking further revealed that hydrogen bonds and hydrophobic forces were generated by omeprazole with the amino acid residues located in the A chain of tyrosinase. Moreover, the results from preservation assays showed that omeprazole could inhibit the activities of polyphenol oxidase (PPO) and peroxidase (POD), prevent the oxidation of total phenolics and flavonoid, thereby delay the browning of fresh-cut apples. Hence, this work identified a novel tyrosinase inhibitor and expands its feasible application as a food preservative.
Assuntos
Conservação de Alimentos/métodos , Malus/enzimologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Omeprazol/farmacologia , Agaricus/enzimologia , Catecol Oxidase/metabolismo , Di-Hidroxifenilalanina/metabolismo , Flavonoides/análise , Cinética , Malus/efeitos dos fármacos , Simulação de Acoplamento Molecular , Omeprazol/química , Peroxidase/metabolismo , Fenóis/análise , Soluções , Espectrometria de Fluorescência , Especificidade por SubstratoRESUMO
This study investigated the structure, antioxidant activity, antityrosinase activity and mechanism of proanthocyanidins from mung bean seed [Vigna radiata (L.) Wilczek]. The structural composition were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionization-full-mass spectrometry (ESI-Full-MS), and high-pressure liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) techniques. The mung bean seed proanthocyanidins were composed of procyanidins, prodelphinidins, and their rhamnosides. According to enzyme kinetic analysis, these compounds were potent, reversible, and mixed-type inhibitors of tyrosinase. They inhibited the enzyme activity by interacting with enzyme as well as substrates. The results of molecular docking showed that the interaction between mung bean seed proanthocyanidins and tyrosinase was driven by hydrogen bond, hydrophobic and electrostatic interactions. In addition, mung bean seed proanthocyanidins were demonstrated as powerful antioxidants. Therefore, this study confirmed a novel tyrosinase inhibitor and would lay a scientific foundation for their utilization in pharmaceutical and food industries.