Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
J Colloid Interface Sci ; 673: 616-627, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38897063

RESUMEN

Oxygen evolution reaction (OER) is the efficiency limiting half-reaction in water electrolysis for green hydrogen production due to the 4-electron multistep process with sluggish kinetics. The electrooxidation of thermodynamically more favorable organics accompanied by CC coupling is a promising way to synthesize value-added chemicals instead of OER. Efficient catalyst is of paramount importance to fulfill such a goal. Herein, a molybdenum iron carbide-copper hybrid (Mo2C-FeCu) was designed as anodic catalyst, which demonstrated decent OER catalytic capability with low overpotential of 238 mV at response current density of 10 mA cm-2 and fine stability. More importantly, the Mo2C-FeCu enabled electrooxidation assisted aldol condensation of phenylcarbinol with α-H containing alcohol/ketone in weak alkali electrolyte to selective synthesize cinnamaldehyde/benzalacetone at reduced potential. The hydroxyl and superoxide intermediate radicals generated at high potential are deemed to be responsible for the electrooxidation of phenylcarbinol and aldol condensation reactions to afford cinnamaldehyde/benzalacetone. The current work showcases an electrochemical-chemical combined CC coupling reaction to prepare organic chemicals, we believe more widespread organics can be synthesized by tailored electrochemical reactions.

2.
Adv Clin Exp Med ; 33(1): 61-68, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37278107

RESUMEN

BACKGROUND: Cutaneous squamous cell carcinoma (cSCC) and cutaneous basal cell carcinoma (cBCC) are the most common types of non-melanoma skin cancer (NMSC). The NACHT, LRR and PYD domains-containing protein 1 (NLRP1) protein is considered to be inhibited in NMSC, although clinical evidence is still lacking. OBJECTIVES: To investigate the clinical significance of NLRP1 in cSCC and cBCC patients. MATERIAL AND METHODS: This prospective observational study enrolled 199 cases of cBCC and cSCC patients who reported to our hospital from January 2018 to January 2019. Additionally, 199 blood samples from healthy individuals were collected as the control. Serum NLRP1 and cancer biomarkers of CEA and CYFRA21-1 were then measured using enzyme-linked immunosorbent assay (ELISA). Clinical characteristics collected from patients included age, sex, BMI, TNM stage, cancer type, lymph node metastasis, and myometrial infiltration conditions. All patients were followed up for 1-3 years. RESULTS: Of all patients, 23 died during the follow-up period, with a mortality rate of 11.56%. Serum NLRP1 showed markedly lower levels in cancer patients compared with healthy controls. Furthermore, the expression of NLRP1 was significantly higher in cBCC patients compared with cSCC patients. The deceased patients, together with those with lymph node metastasis and myometrial infiltration, also showed significantly lower NLRP1 levels. Moreover, lower NLRP1 levels were associated with higher frequencies of tumor-nodule-metastasis (TNM) III-IV stage, lymph node metastasis and myometrial infiltration, as well as higher mortality and recurrence rates. The curvilinear regression showed the relationship between NLRP1 and CEA/or CYFRA21-1 was most appropriate for the reciprocal. Receiver operating characteristic (ROC) curves showed NLRP1 was a potential biomarker for lymph node metastasis, myometrial infiltration and prognosis in NMSC patients, and the Kaplan-Meier analysis found NLRP1 was associated with 1-3-year mortality and recurrence of NMSC. CONCLUSIONS: Lower NLRP1 level is associated with worse clinical outcomes and poorer prognosis in cSCC and cBCC patients.


Asunto(s)
Antígenos de Neoplasias , Carcinoma de Células Escamosas , Carnitina/análogos & derivados , Queratina-19 , Neoplasias Cutáneas , Humanos , Neoplasias Cutáneas/patología , Carcinoma de Células Escamosas/patología , Metástasis Linfática , Pronóstico , Proteínas NLR
3.
BMC Bioinformatics ; 24(1): 310, 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37568078

RESUMEN

BACKGROUND: Accurate estimation of the effective reproductive number ([Formula: see text]) of epidemic outbreaks is of central relevance to public health policy and decision making. We present estimateR, an R package for the estimation of the reproductive number through time from delayed observations of infection events. Such delayed observations include confirmed cases, hospitalizations or deaths. The package implements the methodology of Huisman et al. but modularizes the [Formula: see text] estimation procedure to allow easy implementation of new alternatives to the currently available methods. Users can tailor their analyses according to their particular use case by choosing among implemented options. RESULTS: The estimateR R package allows users to estimate the effective reproductive number of an epidemic outbreak based on observed cases, hospitalization, death or any other type of event documenting past infections, in a fast and timely fashion. We validated the implementation with a simulation study: estimateR yielded estimates comparable to alternative publicly available methods while being around two orders of magnitude faster. We then applied estimateR to empirical case-confirmation incidence data for COVID-19 in nine countries and for dengue fever in Brazil; in parallel, estimateR is already being applied (i) to SARS-CoV-2 measurements in wastewater data and (ii) to study influenza transmission based on wastewater and clinical data in other studies. In summary, this R package provides a fast and flexible implementation to estimate the effective reproductive number for various diseases and datasets. CONCLUSIONS: The estimateR R package is a modular and extendable tool designed for outbreak surveillance and retrospective outbreak investigation. It extends the method developed for COVID-19 by Huisman et al. and makes it available for a variety of pathogens, outbreak scenarios, and observation types. Estimates obtained with estimateR can be interpreted directly or used to inform more complex epidemic models (e.g. for forecasting) on the value of [Formula: see text].


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , SARS-CoV-2 , Número Básico de Reproducción , Estudios Retrospectivos , Aguas Residuales
4.
ACS Nano ; 17(11): 10947-10957, 2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-37200598

RESUMEN

Developing highly active and robust electrocatalysts for the hydrogen/oxygen evolution reaction (HER/OER) is crucial for the large-scale utilization of green hydrogen. In this study, a collaborative interface optimization guided strategy was employed to prepare a metal-organic framework (MOF) derived heterostructure electrocatalyst (MXene@RuCo NPs). The obtained electrocatalyst requires overpotentials of only 20 mV for the HER and 253 mV for the OER to deliver a current density of 10 mA/cm2 in alkaline media, respectively, and it also exhibits great performance at high current density. Experiments and theoretical calculations reveal that the doped Ru introduces second active sites and decreases the diameter of nanoparticles, which greatly enhances the number of active sites. More importantly, the MXene/RuCo NPs heterogeneous interfaces in the catalysts exhibit great synergistic effects, decreasing the work function of the catalyst and improving the charge transfer rate, thus reducing the energy barrier of the catalytic reaction. This work represents a promising strategy for the development of MOF-derived highly active catalysts to achieve efficient energy conversion in industrial applications.

5.
Front Oncol ; 13: 1062142, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37007147

RESUMEN

Background: Lymph node status is an important factor in determining the prognosis of patients with early gastric cancer (EGC) and preoperative diagnosis of lymph node metastasis (LNM) has some limitations. This study explored the risk factors and independent prognostic factors of LNM in EGC patients and constructed a clinical prediction model to predict LNM. Methods: Clinicopathological data of EGC patients was collected from the public Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate logistic regression was used to identify risk factors for LNM in EGC patients. The performance of the LNM model was evaluated by C-index, calibration curve, receiver operating characteristic (ROC) curve, decision curve analysis (DCA) curve, and clinical impact curve (CIC) based on the results of multivariate regression to develop a nomogram. An independent data set was obtained from China for external validation. The Kaplan-Meier method and Cox regression model were used to identify potential prognostic factors for overall survival (OS) in EGC patients. Results: A total of 3993 EGC patients were randomly allocated to a training cohort (n=2797) and a validation cohort (n=1196). An external cohort of 106 patients from the Second Hospital of Lanzhou University was used for external validation. Univariate and multivariate logistic regression showed that age, tumor size, differentiation, and examined lymph nodes count (ELNC) were independent risk factors for LNM. Nomogram for predicting LNM in EGC patients was developed and validated. The predictive model had a good discriminatory performance with a concordance index (C-index) of 0.702 (95% CI: 0.679-0.725). The calibration plots showed that the predicted LNM probabilities were the same as the actual observations in both the internal validation cohort and external validation cohort. The AUC values for the training cohort, internal validation cohort and external validation cohort were 0.702 (95% CI: 0.679-0.725), 0.709 (95% CI: 0.674-0.744) and 0.750(95% CI: 0.607-0.892), respectively, and the DCA curves and CIC showed good clinical applicability. The Cox regression model identified age, sex, race, primary site, size, pathological type, LNM, distant metastasis, and ELNC were prognostic factors for OS in EGC patients, while a year at diagnosis, grade, marital status, radiotherapy, and chemotherapy were not independent prognostic factors. Conclusion: In this study, we identified risk factors and independent prognostic factors for the development of LNM in EGC patients, and developed a relatively accurate model to predict the development of LNM in EGC patients.

6.
Elife ; 112022 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-35938911

RESUMEN

The effective reproductive number Re is a key indicator of the growth of an epidemic. Since the start of the SARS-CoV-2 pandemic, many methods and online dashboards have sprung up to monitor this number through time. However, these methods are not always thoroughly tested, correctly placed in time, or are overly confident during high incidence periods. Here, we present a method for timely estimation of Re, applied to COVID-19 epidemic data from 170 countries. We thoroughly evaluate the method on simulated data, and present an intuitive web interface for interactive data exploration. We show that, in early 2020, in the majority of countries the estimated Re dropped below 1 only after the introduction of major non-pharmaceutical interventions. For Europe the implementation of non-pharmaceutical interventions was broadly associated with reductions in the estimated Re. Globally though, relaxing non-pharmaceutical interventions had more varied effects on subsequent Re estimates. Our framework is useful to inform governments and the general public on the status of epidemics in their country, and is used as the official source of Re estimates for SARS-CoV-2 in Switzerland. It further allows detailed comparison between countries and in relation to covariates such as implemented public health policies, mobility, behaviour, or weather data.


Over the past two and a half years, countries around the globe have struggled to control the transmission of the SARS-CoV-2 virus within their borders. To manage the situation, it is important to have an accurate picture of how fast the virus is spreading. This can be achieved by calculating the effective reproductive number (Re), which describes how many people, on average, someone with COVID-19 is likely to infect. If the Re is greater than one, the virus is infecting increasingly more people, but if it is smaller than one, the number of cases is declining. Scientists use various strategies to estimate the Re, which each have their own strengths and weaknesses. One of the main difficulties is that infections are typically recorded only when people test positive for COVID-19, are hospitalized with the virus, or die. This means that the data provides a delayed representation of when infections are happening. Furthermore, changes in these records occur later than measures that change the infection dynamics. As a result, researchers need to take these delays into account when estimating Re. Here, Huisman, Scire et al. have developed a new method for estimating the Re based on available data records, statistically taking into account the above-mentioned delays. An online dashboard with daily updates was then created so that policy makers and the population could monitor the values over time. For over two years, Huisman, Scire et al. have been applying their tool and dashboard to COVID-19 data from 170 countries. They found that public health interventions, such as mask requirements and lockdowns, did help reduce the Re in Europe. But the effects were not uniform across the globe, likely because of variations in how restrictions were implemented and followed during the pandemic. In early 2020, the Re only dropped below one after countries put lockdowns or other severe measures in place. The Re values added to the dashboard over the last two years have been used pro-actively to inform public health policies in Switzerland and to monitor the spread of SARS-CoV-2 in South Africa. The team has also recently released programming software based on this method that can be used to track future disease outbreaks, and extended the method to estimate the Re using SARS-CoV-2 levels in wastewater.


Asunto(s)
COVID-19 , SARS-CoV-2 , Número Básico de Reproducción , COVID-19/epidemiología , Europa (Continente)/epidemiología , Humanos , Pandemias/prevención & control
7.
J Colloid Interface Sci ; 628(Pt A): 607-618, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-35940145

RESUMEN

Efficient and durable nonprecious catalysts for the oxygen evolution reaction (OER) are crucial for practical water electrolysis for hydrogen production. A self-supported OER catalytic electrode with sufficient exposure of the catalyst and tight anchoring onto the current collector is vital for the catalytic activity and stability, and is therefore deemed to be a preferable tactic to enhance water electrolysis performance. Herein, a polyoxometalate (POM) molecular cluster-mediated electroplating and activation tactics are proposed to design a self-supported molybdenum nickel oxide (MoNiOx) catalytic electrode for the OER. The MoNiOx active layer can anchor tightly onto the Ni foam current collector with sufficient surface exposure and high structural stability, therefore enabling high alkali OER catalytic efficiency (222 mV at 10 mA cm-2) and robust durability (only slight decay in catalytic efficiency upon 12 days of chronopotentiometry (V-t) test). Moreover, the easily processable electroplating and active protocol can serve as a general approach to prepare other OER catalytic electrodes by altering the reactants and current collectors. The current work paves a facile and universal way to design a highly active and durable molybdenum (Mo) based hybrid catalytic electrode for OER via molecular cluster-assisted electroplating and activation treatment.

8.
EMBO Rep ; 23(9): e54611, 2022 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-35833522

RESUMEN

Inflammasomes are cytosolic multiprotein complexes that initiate host defense against bacterial pathogens. The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family caspase-associated recruitment domain-containing protein 4 (NLRC4) inflammasomes plays a critical role in the inflammatory response against intracellular bacterial infection. The NLR family apoptosis inhibitory proteins (NAIPs) detect Flagellin or type III secretion system (T3SS) microbial components to activate NLRC4 inflammasome. However, the underlying mechanism of NLRC4 inflammasome activation is not completely understood. Here, we show that the vitamin D receptor (VDR) is an essential immunological regulator of the NLRC4 inflammasome. Conditional VDR knockout mice (VDRflox/flox lyz2-Cre) exhibited impaired clearance of pathogens after acute Salmonella Typhimurium infection leading to poor survival. In macrophages, VDR deficiency reduced caspase-1 activation and IL-1ß secretion upon S. Typhimurium infection. For NAIPs act as upstream sensors for NLRC4 inflammasome assembly, the further study demonstrated that VDR promoted the NAIP-NLRC4 association and triggered NAIP-NLRC4 inflammasome activation, not NLRP3 activation. Moreover, Lys123 residue of VDR is identified as the critical amino acid for VDR-NLRC4 interaction, and the mutant VDR (K123A) effectively attenuates the NLRC4 inflammasome activation. Together, our findings suggest that VDR is a critical regulator of NAIPs-NLRC4 inflammasome activation, mediating innate immunity against bacterial infection.


Asunto(s)
Proteínas Reguladoras de la Apoptosis , Infecciones Bacterianas , Proteínas de Unión al Calcio , Inflamasomas , Receptores de Calcitriol , Animales , Proteínas Reguladoras de la Apoptosis/metabolismo , Proteínas Adaptadoras de Señalización CARD/metabolismo , Proteínas de Unión al Calcio/metabolismo , Caspasas/metabolismo , Inflamasomas/metabolismo , Ratones , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo
9.
J Colloid Interface Sci ; 606(Pt 2): 1662-1672, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34507166

RESUMEN

Efficient and durable non-precious catalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is pivotal for practical water electrolysis toward clean hydrogen fuel. Herein, a molybdenum oxide-FeCoCu alloy hybrid (MoOx-FeCoCu) catalyst was designed by polyoxometallate (POM) molecular cluster mediated solvothermal alcoholysis and ammonolysis of metal salts followed by pyrolytic reduction treatment. The HER efficiency is substantially enhanced by the ternary alloy component, which is more close to the benchmark Pt/C catalyst, and the HER catalytic stability is also superior to Pt/C catalyst. Moreover, the MoOx-FeCoCu demonstrates high catalytic efficiency and rather good durability for OER. Benefitted by the bifunctional catalytic behaviors for HER and OER, the symmetric water electrolyzer based on the MoOx-FeCoCu electrode requires a low driving voltage of 1.69 V to deliver a response current density of 10 mA cm-2, which is comparable to that based on the benchmark Pt/C HER cathode and RuO2 OER anode. The current work offers a feasible way to design efficient bifunctional catalyst for water electrolysis via POM mediated co-assembly and calcination treatment.

10.
Phytomedicine ; 87: 153580, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34029939

RESUMEN

BACKGROUNDS: Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancer with high metastasis and recurrence rates. Hypoxia-induced miRNAs and HIF-1α are demonstrated to play essential roles in tumor metastasis. Matrine (C15H24N2O), an alkaloid extracted from Sophora flavescens Aiton, has been used as adjuvant therapy for liver cancer in China. The anti-metastasis effects of matrine on HCC and the underlying mechanisms remain poorly understood. PURPOSE: We aimed to investigate the effects of matrine on metastasis of HCC both in vitro and in vivo, and explored whether miR-199a-5p and HIF-1α are involved in the action of matrine. METHODS: MTT method, colony formation, wound healing and matrigel transwell assays were performed to evaluate the effects of matrine on cell proliferation, migration and invasion. Nude mice xenograft model and immunohistochemistry (IHC) assay were employed to investigate the anti-metastatic action of matrine in vivo. Quantitative real-time PCR, western blot and dual luciferase reporter assay were conducted to determine the underlying mechanisms of matrine. RESULTS: Matrine exerted stronger anti-proliferative action on Bel7402 and SMMC-7721 cells under hypoxia than that in normoxia. Both matrine and miR-199a-5p exhibited significant inhibitory effects on migration, invasion and EMT in Bel7402 and SMMC-7721 cells under hypoxia. Further study showed that miR-199a-5p was downregulated in HCC cell lines, and this microRNA was identified to directly target HIF-1α, resulting in decreased HIF-1α expression. Matrine induced miR-199a-5p expression, decreased HIF-1α expression and inhibited metastasis of Bel7402 and SMMC-7721 cells, while miR-199a-5p knockdown reversed the inhibitory effects of matrine on cell migration, invasion, EMT and HIF-1α expression. In vivo, matrine showed significant anti-metastatic activity in the nude mouse xenograft model. H&E and IHC analysis indicated that lung and liver metastasis nodules were reduced, and the protein expression of HIF-1α and Vimentin were significantly decreased by i.p injection of matrine. CONCLUSIONS: Matrine exhibits significant anti-metastatic effect on HCC, which is attributed to enhanced miR-199a-5p expression and subsequently impaired HIF-1α signaling and EMT. These findings suggest that miR-199a-5p is a potential therapeutic target of HCC, and matrine may represent a promising anti-metastatic medication for HCC therapy.


Asunto(s)
Alcaloides/farmacología , Antineoplásicos Fitogénicos/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Quinolizinas/farmacología , Animales , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Transición Epitelial-Mesenquimal/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Neoplasias Hepáticas/patología , Ratones Desnudos , MicroARNs/genética , Recurrencia Local de Neoplasia , Sophora/química , Ensayos Antitumor por Modelo de Xenoinjerto , Matrinas
11.
J Colloid Interface Sci ; 579: 667-679, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-32652322

RESUMEN

Ultrathin carbon sheets with high surface area, abundant mesoporous structure and rich N, O heteroatom doping sites were prepared from puffed rice through unique sealed pre-carbonization. By utilizing them as cathode materials for lithium-sulfur batteries, the in-operando Raman spectra and electrochemical tests indicated that the polysulfides shuttling effect could be substantially suppressed by the physical confinement and chemical adsorption due to these structural advantages. In addition, the well-developed hierarchical porous structure and ultrathin thickness were found to enhance the mass diffusion in the electrode, which increased the ion conductivity within the carbon framework. Therefore, the as-designed cathode was observed to accommodate the high sulfur loading amounts and demonstrated a high reversible capacity of 920.8 mAh g-1 after 100 cycles at 0.2C with high coulombic efficiency (~100%). Moreover, the long-term stability test at 1C indicated that the cathode achieved a high reversible capacity of 702.1 mAh g-1 after 300 cycles with low decay rate of 0.07% per cycle.

12.
Nan Fang Yi Ke Da Xue Xue Bao ; 39(10): 1239-1245, 2019 Oct 30.
Artículo en Chino | MEDLINE | ID: mdl-31801708

RESUMEN

OBJECTIVE: To explore the effects of matrine on the proliferation, tumor cell stemness, ß-catenin transcriptional activity and AKT/GSK3ß/ß-catenin signaling pathway in human hepatocellular carcinoma (HCC) HepG2 and Huh7 cells. METHODS: The proliferation and colony formation ability of HepG2 and Huh7 cells treated with 200, 400, and 800 µg/mL matrine were evaluated with MTT assay and colony formation assay, respectively. Real-time quantitative PCR was performed to detect the mRNA expressions of CD90, epithelial cell adhesion molecule (EpCAM) and CD133, and dual-luciferase assay was used to detect the transcriptional activity of ß-catenin in the treated cells. The effects of matrine on the expressions of protein kinase B (AKT), P-AKT, GSK-3ß, P-GSK-3ß, P-ß-catenin and ß-catenin proteins in the Wnt/ß-catenin signaling pathway were assessed using Western blotting. RESULTS: Matrine inhibited the proliferation of the two HCC cell lines in a time- and concentration-dependent manner. The half-inhibitory concentrations of matrine were 2369, 1565 and 909.1 µg/mL at 24, 48 and 72 h in HepG2 cells, respectively, and were 1355, 781.8, and 612.8 µg/mL in Huh7 cells, respectively. Matrine concentrationdependently suppressed colony formation of the HCC cells, producing significant inhibitory effects at 400 µg/mL P < 0.01) and 800 µg/mL P < 0.001) in HepG2 cells and at 200 µg/mL P < 0.05), 400 µg/mL P < 0.01), and 800 µg/mL P < 0.001) in Huh7 cells. Matrine at 400 and 800 µg/mL significantly inhibited the mRNA expression of CD90, EpCAM and CD133 and the transcriptional level of ß-catenin in both HepG2 and Huh7 cells P < 0.05 or 0.01). Matrine at 400 and 800 µg/mL also significantly decreased the protein levels of ß-catenin, P-AKT and P-GSK-3ß and increased the phosphorylation level of ß-catenin in both of the cell lines. CONCLUSIONS: Matrine inhibits the proliferation, colony formation, and the expressions of tumor stem cell markers CD90, EpCAM and CD133 in both HepG2 and Huh7 cells probably by inhibiting Wnt/ß-catenin signaling pathway and the transcriptional activity ofß-catenin.


Asunto(s)
Alcaloides/farmacología , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Células Madre Neoplásicas/efectos de los fármacos , Quinolizinas/farmacología , Vía de Señalización Wnt/efectos de los fármacos , Carcinoma Hepatocelular/tratamiento farmacológico , Línea Celular Tumoral , Proliferación Celular , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , beta Catenina/metabolismo , Matrinas
13.
R Soc Open Sci ; 6(10): 190892, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31824704

RESUMEN

The permeability of the coal body is the key parameter restricting the efficient extraction of coalbed methane, and scholars have analysed it from two angles of the change of stress state and porosity of the coal body. However, there is still a lack of study on the mechanism of gas migration and movement in soft coalbed methane reservoir under the coupling between the true triaxial stress field (maximum principal stress σ 1 > intermediate principal stress σ 2 > minimum principal stress σ 3) and the gas pressure field. In this paper, the coal gas adsorption and seepage experiments are conducted through the self-developed true triaxial 'gas-solid' coupled coal mass seepage system with gas as the adsorption and seepage medium and coal briquette taking the place of soft coalbed methane reservoirs. Furthermore, the coal gas adsorption deformation model and the permeability evolution model taking gas adsorption into account are developed. Through analysis of both experimental and theoretic results, the main conclusions are drawn as follows: (i) With the increase in gas pressure, the adsorption deformation variation of coal mass is divided into a slow growth zone, a stable growth zone and a rapid growth zone. (ii) The gas adsorption deformation model developed can predict the variation trend of coal mass adsorption volumetric strains for different types of soft coalbeds, and the fitting variance of experimental and theoretical volumetric strains is above 98%. (iii) With the increase in maximum principal stress difference, the coal permeability variation curve shows two obvious turning points, which can be divided into a slow reduction zone, a rapid reduction zone and a steady reduction zone. (iv) The permeability model of coal mass considering the gas adsorption effect can reflect the variation characteristics of permeability in the rapid reduction zone, and the overall fitting variance of experimental and theoretical permeabilities is above 91%. The above results could provide a reliable experimental and theoretical basis for improving coalbed methane extraction rates.

14.
J Food Sci ; 83(10): 2593-2601, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30251345

RESUMEN

White tea from the eastern Chinese province of Fujian is a unique tea variety. Although the health effects of various teas have been investigated in recent years, most studies focused exclusively on green tea varieties. In order to study effects exerted by white tea from eastern Fujian on the viability of cancer cells, we analyzed its main bioactive ingredients. We also evaluated the antioxidant activity of white tea aqueous extract (WTAE) and employed MTT assay to evaluate effects of WTAE on viabilities of Hela and BEL-7402 cancer cell lines. Apoptosis rate detection was also applied to estimate efficacy of cellular apoptotic induction by WTAE in these two cells types. Results revealed that WTAE exhibited high antioxidant activity and inhibited effectively the proliferation of Hela and BEL-7402 cells. The half maximal inhibitory concentration (IC50) of WTAE for Hela cells (0.05 mg/mL) was lower than that for BEL-7402 cells (0.1 mg/mL). Although WTAE induced apoptosis in both cell lines, pro-apoptotic effects were markedly more apparent in Hela cells. Our study demonstrated that WTAE inhibited proliferation of cancer cells via induction of apoptosis and that Hela cells were more sensitive to WTAE than BEL-7402 cells. PRACTICAL APPLICATION: The aim of this study is to provide a new approach toward cancer prevention by consuming white tea, the properties of which may also be helpful in formulating novel anticancer therapeutics.


Asunto(s)
Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Extractos Vegetales/farmacología , Té/química , Línea Celular Tumoral , Evaluación Preclínica de Medicamentos , Células HeLa , Humanos , Concentración 50 Inhibidora , Neoplasias/prevención & control
15.
Fungal Biol ; 121(1): 11-20, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28007213

RESUMEN

The Woronin body is a unique organelle in Pezizomycotina species. Following the injury of hyphae, it can quickly seal the septal pores to reduce the loss of cytoplasm and promote hyphal healing. The Woronin body is also considered a significant factor in efficient pathogenesis in many fungal pathogens. In this study, we identified AoHex1, a homologue of Neurospora crassa Hex1, a main component of the Woronin body in the genome of the nematode-trapping fungus Arthrobotrys oligospora. To study the biological function of the AoHex1 gene, the gene was deleted and its phenotypes assessed. Inactivation of this gene led to the loss of the Woronin body. The ΔAoHex1 strain showed compromised growth rate, conidiation, and anti-stress abilities. Moreover, trap formation was completely absent in the mutant strain, which could no longer capture nematodes. Our results suggest that the Woronin body plays an important role in growth, conidiation, anti-stress, trap formation, and virulence against nematodes in A. oligospora.


Asunto(s)
Ascomicetos/crecimiento & desarrollo , Ascomicetos/genética , Proteínas Fúngicas/metabolismo , Nematodos/microbiología , Factores de Virulencia/metabolismo , Animales , Ascomicetos/metabolismo , Proteínas Fúngicas/genética , Eliminación de Gen , Esporas Fúngicas/crecimiento & desarrollo , Estrés Fisiológico , Virulencia , Factores de Virulencia/genética
16.
Fungal Genet Biol ; 92: 33-9, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27174557

RESUMEN

Nutrient conditions are important for trap formation and a switch from saprophytic to predacious lifestyle in nematode-trapping fungi. Arthrobotrys oligospora is a typical nematode-trapping fungus which can capture and kill nematodes by means of traps formed in response to the presence of their prey. A nutrient-limited environment was previously shown to be important for trap formation, which was induced by several inferior nitrogen sources, such as sodium nitrate, in the absence of the cell wall protein AoMad1 in A. oligospora. To characterize the role of nitrate in trap formation, we knocked out four genes in the nitrate assimilation pathway and assessed possible effect of nitrate, host nematode or both on the trap formation in the mutants and the wild type. The results showed that trap induction by nitrate used a distinct pathway that differed from induction by nematodes. Moreover, the nitrate facilitated trap formation in the presence of nematodes. Our findings revealed that the trap formation induced by nematodes or nitrate is influenced by the nitrate assimilation pathway.


Asunto(s)
Ascomicetos/genética , Ascomicetos/metabolismo , Proteínas Fúngicas/genética , Nitratos/metabolismo , Animales , Ascomicetos/fisiología , Cadena Alimentaria , Proteínas Fúngicas/antagonistas & inhibidores , Técnicas de Inactivación de Genes , Redes y Vías Metabólicas/genética , Nematodos/microbiología , Nitrógeno/metabolismo
17.
J Environ Sci (China) ; 26(3): 683-93, 2014 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-25079282

RESUMEN

The 0.7 wt% Pt + 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts were fabricated via different methods, including ultrasonic-assisted membrane reduction (UAMR) co-precipitation, UAMR separation precipitation, co-impregnation, and sequential impregnation. The catalysts were physico-chemically characterized by N2 adsorption, XRD, TEM, and H2-TPR techniques, and evaluated for three-way catalytic activities with simulated automobile exhaust. UAMR co-precipitation- and UAMR separation precipitation-prepared catalysts exhibited a high surface area and metal dispersion, wide λ window and excellent conversion for NOx reduction under lean conditions. Both fresh and aged catalysts from UAMR-precipitation showed the high surface areas of ca. 60-67 m(2)/g and 18-22 m(2)/g, respectively, high metal dispersion of 41%-55%, and small active particle diameters of 2.1-2.7 nm. When these catalysts were aged, the catalysts prepared by the UAMR method exhibited a wider working window (Δλ = 0.284-0.287) than impregnated ones (Δλ = 0.065-0.115) as well as excellent three-way catalytic performance, and showed lower T50 (169°C) and T90 (195°C) for NO reduction than the aged catalysts from impregnation processes, which were at 265 and 309°C, respectively. This implied that the UAMR-separation precipitation has important potential for industrial applications to improve catalytic performance and thermal stability. The fresh and aged 0.7 wt% Pt + 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts prepared by the UAMR-separation precipitation method exhibited better catalytic performance than the corresponding catalysts prepared by conventional impregnation routes.


Asunto(s)
Cerio/química , Platino (Metal)/química , Rodio/química , Circonio/química , Contaminación del Aire/prevención & control , Catálisis
18.
Beijing Da Xue Xue Bao Yi Xue Ban ; 46(2): 226-31, 2014 Apr 18.
Artículo en Chino | MEDLINE | ID: mdl-24743811

RESUMEN

OBJECTIVE: To obtain the baseline data and decision of quantitative analysis for the allocation of scarce health care resources,and for the health policymaking about easing the disease burden, to provide estimation of the economic costs and the disability-adjusted life years (DALYs) loss of the coal worker's pneumoconiosis (CWP) and to explore the influencing factors of the disease burden. METHODS: The CWP inpatients from the Institute of Occupational Diseases Prevention and Control of a Coal Mining Group for 2011 were recruited in the study. Multiple dimensions of the disease burden were measured in the inception cohort of the 194 CWP inpatients: the direct economic burden, the indirect economic burden and the DALYs loss. The direct economic burden of the inpatients included hospitalization expenses and food allowances and nutritional supplements. The indirect economic burden was estimated using the DALYs and human capital approach,and the influencing factors of hospitalization expenses were analyzed in this study. RESULTS: The estimated direct economic burden for the 194 CWP inpatients for 2011 was approximately 4.68 million yuan and direct burden per capita was 24 108.05 yuan, and their indirect burden about 6.98 million yuan and indirect burden per capita 35 977.36 yuan. The study discovered that 1 681.53 health years were lost for the CWP inpaitents and per capita health years loss (8.67±3.65) years. CONCLUSION: The medical cost, the indirect cost and the DALYs loss of CWP are all sizable. Age and length of stay in the hospital are the major influencing factors for high hospitalization expenses. The hospitalization expenses of the CWP inpatients increase with their age and length of stay in the hospital. Taking effective measures to reduce the morbility is the key point to reduce the CWP burden.


Asunto(s)
Antracosis/epidemiología , Costo de Enfermedad , Costos y Análisis de Costo , Humanos , Pacientes Internos , Años de Vida Ajustados por Calidad de Vida
19.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 2): e19, 2010 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-21579582

RESUMEN

The title of the paper by Li, Li, Li, Zhang & Li [Acta Cryst. (2009), E65, o1824] is corrected.[This corrects the article DOI: 10.1107/S1600536809025586.].

20.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 8): o1824, 2009 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-21583526

RESUMEN

The title compound, C(25)H(19)N(3)O(2), crystallizes as discrete mol-ecules which are well ordered through one intra-molecular N-H⋯O hydrogen bond. Structural analysis indicates that the mol-ecules exist as the amine-one form.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...