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1.
Glob Chang Biol ; 30(6): e17381, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38923235

RESUMO

In 2020, anthropogenic methane (CH4) emissions decreased due to COVID-19 containment policies, but there was a substantial increase in the concentration of atmospheric CH4. Previous research suggested that this abnormal increase was linked to higher wetland CH4 emissions and a decrease in the atmospheric CH4 sink. However, the impact of changes in the soil CH4 sink remained unknown. To address this, we utilized a process-based model to quantify alterations in the soil CH4 sink of terrestrial ecosystems between 2019 and 2020. By implementing the model with various datasets, we consistently observed an increase in the global soil CH4 sink, reaching up to 0.35 ± 0.06 Tg in 2020 compared to 2019. This increase was primarily attributed to warmer soil temperatures in northern high latitudes. Our results emphasize the importance of considering the CH4 sink in terrestrial ecosystems, as neglecting this component can lead to an underestimation of both emission increases and reductions in atmospheric CH4 sink capacity. Furthermore, these findings highlight the potential role of increased soil warmth in terrestrial ecosystems in slowing the growth of CH4 concentrations in the atmosphere.


Assuntos
Atmosfera , Metano , Solo , Metano/análise , Solo/química , Atmosfera/química , Ecossistema , Modelos Teóricos , Temperatura
2.
Nano Lett ; 23(3): 1061-1067, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36662173

RESUMO

Thin films of ZnO nanocrystals are actively pursued as electron-transporting layers (ETLs) in quantum-dot light-emitting diodes (QLEDs). However, the developments of ZnO-based ETLs are highly engineering oriented and the design of ZnO-based ETLs remains empirical. Here, we identified a previously overlooked efficiency-loss channel associated with the ZnO-based ETLs: i.e., interfacial exciton quenching induced by surface-bound ethanol. Accordingly, we developed a general surface-treatment procedure to replace the redox-active surface-bound ethanol with electrochemically inert alkali carboxylates. Characterization results show that the surface treatment procedure does not change other key properties of the ETLs, such as the conductance and work function. Our single-variable experimental design unambiguously demonstrates that improving the electrochemical stabilities of the ZnO ETLs leads to QLEDs with a higher efficiency and longer operational lifetime. Our work provides a crucial guideline to design ZnO-based ETLs for optoelectronic devices.

3.
Anal Chem ; 95(2): 792-801, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36520837

RESUMO

Ligand exchange is fundamentally related to the surface chemistry of nanoparticles in solution and is also an essential procedure for their synthesis and solution processing. The solution of ligand-bearing nanoparticles can be regarded as a dynamic equilibrium of bound and free ligands depending on the concentration and temperature. The direct experimental calibration of the ligand exchange dynamics relies on the in situ and real-time quantification of bound and free ligands. However, existing analytical strategies are often with limited applicability considering the requirement of special functional groups or the indirect detection of photoluminescence or reaction heat. In this work, we explore diffusion-based methods of solution-state nuclear magnetic resonance (NMR) as a general strategy to probe ligand exchange. Using comprehensive numerical simulations, we show that diffusion NMR with designable time sequences can effectively distinguish bound and free ligands and measure the exchange rate constants from 0.5 to 200 s-1 under typical instrumental settings. These methods are demonstrated experimentally on colloidal CdSe nanocrystal systems with carboxylate or amine ligands whose exchange rates were previously undetectable. The kinetic rate constants, activation energies, and thermodynamic parameters of ligand exchange have been obtained under variable temperature conditions. We expect the diffusion NMR strategies to be generally applicable for calibrating the exchange of organic ligands on various nanoparticle systems.


Assuntos
Nanopartículas , Ligantes , Nanopartículas/química , Espectroscopia de Ressonância Magnética , Termodinâmica , Temperatura
4.
BMC Cancer ; 23(1): 1092, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37950223

RESUMO

OBJECTIVES: Preoperative imaging of vascular invasion is important for surgical resection of pancreatic ductal adenocarcinoma (PDAC). However, whether MRI and CT share the same evaluation criteria remains unclear. This study aimed to compare the diagnostic accuracy of high-resolution MRI (HR-MRI), conventional MRI (non-HR-MRI) and CT for PDAC vascular invasion. METHODS: Pathologically proven PDAC with preoperative HR-MRI (79 cases, 58 with CT) and non-HR-MRI (77 cases, 59 with CT) were retrospectively collected. Vascular invasion was confirmed surgically or pathologically. The degree of tumour-vascular contact, vessel narrowing and contour irregularity were reviewed respectively. Diagnostic criteria 1 (C1) was the presence of all three characteristics, and criteria 2 (C2) was the presence of any one of them. The diagnostic efficacies of different examination methods and criteria were evaluated and compared. RESULTS: HR-MRI showed satisfactory performance in assessing vascular invasion (AUC: 0.87-0.92), especially better sensitivity (0.79-0.86 vs. 0.40-0.79) than that with non-HR-MRI and CT. HR-MRI was superior to non-HR-MRI. C2 was superior to C1 on CT evaluation (0.85 vs. 0.79, P = 0.03). C1 was superior to C2 in the venous assessment using HR-MRI (0.90 vs. 0.87, P = 0.04) and in the arterial assessment using non-HR-MRI (0.69 vs. 0.68, P = 0.04). The combination of C1-assessed HR-MRI and C2-assessed CT was significantly better than that of CT alone (0.96 vs. 0.86, P = 0.04). CONCLUSIONS: HR-MRI more accurately assessed PDAC vascular invasion than conventional MRI and may contribute to operative decision-making. C1 was more applicable to MRI scans, and C2 to CT scans. The combination of C1-assessed HR-MRI and C2-assessed CT outperformed CT alone and showed the best efficacy in preoperative examination of PDAC.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Estudos Retrospectivos , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/cirurgia , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/diagnóstico por imagem , Carcinoma Ductal Pancreático/cirurgia , Carcinoma Ductal Pancreático/patologia , Imageamento por Ressonância Magnética , Neoplasias Pancreáticas
5.
J Magn Reson Imaging ; 58(1): 12-25, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36971442

RESUMO

This review aimed to perform a scoping review of promising MRI methods in assessing tumor hypoxia in hepatocellular carcinoma (HCC). The hypoxic microenvironment and upregulated hypoxic metabolism in HCC are determining factors of poor prognosis, increased metastatic potential, and resistance to chemotherapy and radiotherapy. Assessing hypoxia in HCC is essential for personalized therapy and predicting prognoses. Oxygen electrodes, protein markers, optical imaging, and positron emission tomography can evaluate tumor hypoxia. These methods lack clinical applicability because of invasiveness, tissue depth, and radiation exposure. MRI methods, including blood oxygenation level-dependent, dynamic contrast-enhanced MRI, diffusion-weighted imaging, MRI spectroscopy, chemical exchange saturation transfer MRI, and multinuclear MRI, are promising noninvasive methods that evaluate the hypoxic microenvironment by observing biochemical processes in vivo, which may inform on therapeutic options. This review summarizes the recent challenges and advances in MRI techniques for assessing hypoxia in HCC and highlights the potential of MRI methods for examining the hypoxic microenvironment via specific metabolic substrates and pathways. Although the utilization of MRI methods for evaluating hypoxia in patients with HCC is increasing, rigorous validation is needed in order to translate these MRI methods into clinical use. Due to the limited sensitivity and specificity of current quantitative MRI methods, their acquisition and analysis protocols require further improvement. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 4.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética/métodos , Hipóxia/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Microambiente Tumoral
6.
Eur J Neurol ; 30(11): 3568-3580, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37399128

RESUMO

BACKGROUND AND PURPOSE: The gut microbiome has been reported to be closely related to Alzheimer's disease (AD) progression. Here, a comprehensive meta-analysis of gut microbial characteristics in AD, mild cognitive impairment (MCI) and subjective cognitive decline (SCD) was performed to compare gut microbial alterations at each stage. METHODS: A total of 10 databases (CNKI, WanFang, VIP, SinoMed, WOS, PubMed, Embase, Cochrane Library, PsycINFO and Void) were searched and 34 case-control studies were included. α and ß diversity and the relative abundance of gut microbiota were analysed as outcome indices. Data analysis was performed using Review Manager (5.4.1) and R. RESULTS: Chao1 and Shannon index levels in AD were significantly lower compared with healthy controls (HCs), and the Chao1 index was significantly lower in MCI compared with HCs. There was a significant difference in ß diversity of gut microbiomes in patients (SCD, MCI, AD) compared with HCs. The relative abundance of Firmicutes at the phylum level was significantly lower in patients with AD and MCI than HCs. However, the relative abundance of Bacteroidetes at the phylum level was significantly higher in patients with MCI than HCs. There was an increasing trend for Enterobacteriaceae and a decreasing trend for Ruminococcaceae, Lachnospiraceae and Lactobacillus during AD; Lactobacillus showed a decreasing trend early in SCD. CONCLUSION: Our results indicated that there were gut microbiological abnormalities in AD, even as early as the SCD stage. The dynamic, consistent changes in gut microbes with the disease process showed that they might serve as potential biomarkers for early identification and diagnosis of AD.

7.
Lancet ; 397(10279): 1075-1084, 2021 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-33743869

RESUMO

BACKGROUND: Wuhan was the epicentre of the COVID-19 outbreak in China. We aimed to determine the seroprevalence and kinetics of anti-SARS-CoV-2 antibodies at population level in Wuhan to inform the development of vaccination strategies. METHODS: In this longitudinal cross-sectional study, we used a multistage, population-stratified, cluster random sampling method to systematically select 100 communities from the 13 districts of Wuhan. Households were systematically selected from each community and all family members were invited to community health-care centres to participate. Eligible individuals were those who had lived in Wuhan for at least 14 days since Dec 1, 2019. All eligible participants who consented to participate completed a standardised electronic questionnaire of demographic and clinical questions and self-reported any symptoms associated with COVID-19 or previous diagnosis of COVID-19. A venous blood sample was taken for immunological testing on April 14-15, 2020. Blood samples were tested for the presence of pan-immunoglobulins, IgM, IgA, and IgG antibodies against SARS-CoV-2 nucleocapsid protein and neutralising antibodies were assessed. We did two successive follow-ups between June 11 and June 13, and between Oct 9 and Dec 5, 2020, at which blood samples were taken. FINDINGS: Of 4600 households randomly selected, 3599 families (78·2%) with 9702 individuals attended the baseline visit. 9542 individuals from 3556 families had sufficient samples for analyses. 532 (5·6%) of 9542 participants were positive for pan-immunoglobulins against SARS-CoV-2, with a baseline adjusted seroprevalence of 6·92% (95% CI 6·41-7·43) in the population. 437 (82·1%) of 532 participants who were positive for pan-immunoglobulins were asymptomatic. 69 (13·0%) of 532 individuals were positive for IgM antibodies, 84 (15·8%) were positive for IgA antibodies, 532 (100%) were positive for IgG antibodies, and 212 (39·8%) were positive for neutralising antibodies at baseline. The proportion of individuals who were positive for pan-immunoglobulins who had neutralising antibodies in April remained stable for the two follow-up visits (162 [44·6%] of 363 in June, 2020, and 187 [41·2%] of 454 in October-December, 2020). On the basis of data from 335 individuals who attended all three follow-up visits and who were positive for pan-immunoglobulins, neutralising antibody levels did not significantly decrease over the study period (median 1/5·6 [IQR 1/2·0 to 1/14·0] at baseline vs 1/5·6 [1/4·0 to 1/11·2] at first follow-up [p=1·0] and 1/6·3 [1/2·0 to 1/12·6] at second follow-up [p=0·29]). However, neutralising antibody titres were lower in asymptomatic individuals than in confirmed cases and symptomatic individuals. Although titres of IgG decreased over time, the proportion of individuals who had IgG antibodies did not decrease substantially (from 30 [100%] of 30 at baseline to 26 [89·7%] of 29 at second follow-up among confirmed cases, 65 [100%] of 65 at baseline to 58 [92·1%] of 63 at second follow-up among symptomatic individuals, and 437 [100%] of 437 at baseline to 329 [90·9%] of 362 at second follow-up among asymptomatic individuals). INTERPRETATION: 6·92% of a cross-sectional sample of the population of Wuhan developed antibodies against SARS-CoV-2, with 39·8% of this population seroconverting to have neutralising antibodies. Our durability data on humoral responses indicate that mass vaccination is needed to effect herd protection to prevent the resurgence of the epidemic. FUNDING: Chinese Academy of Medical Sciences & Peking Union Medical College, National Natural Science Foundation, and Chinese Ministry of Science and Technology. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , COVID-19/imunologia , SARS-CoV-2/imunologia , Adolescente , Adulto , Idoso , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/sangue , COVID-19/epidemiologia , COVID-19/prevenção & controle , Criança , Pré-Escolar , China/epidemiologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Estudos Transversais , Feminino , Seguimentos , Humanos , Imunidade Coletiva/imunologia , Imunidade Humoral , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Vacinação em Massa/organização & administração , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Adulto Jovem
8.
Mol Pharm ; 19(5): 1368-1377, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35393860

RESUMO

Inflammation plays a significant role in many physiological and pathological processes. Molecular imaging could provide functional as well as anatomical information for visualizing various inflammatory diseases. Advancements in imaging tracers for inflammation would improve the accuracy of diagnosis and monitoring, thus facilitating patient care. The positron emission tomography (PET) imaging tracer, 68Ga-labeled antagonist peptide Trp-Arg-Trp-Trp-Trp-Trp (WRWWWW, WRW4), targets formyl peptide receptor 2 (FPR2), which is in turn widely distributed in a variety of tissues and is associated with many inflammatory diseases. In the current study, we aimed to investigate the potential of 68Ga-WRW4 for detecting and monitoring inflammatory lesions in mice. We established an inflammation mouse model by the intramuscular injection of turpentine oil into the left thigh. WRW4 was labeled with 68Ga with an overall radiochemical yield >90% and radiochemical purity >99%. 68Ga-WRW4 uptake in inflamed muscle peaked on day 2 (1.14 ± 0.01 percentage of the injected dose per gram of tissue (%ID/g)) and the uptake ratio of inflammatory/normal muscle also reached a maximum (12.36 ± 2.35). Strong PET signals were detected in the left thigh at 60 min after the injection of 68Ga-WRW4 in experimental mice, but weak or no signals were detected in mice in the blocking and control groups. 68Ga-WRW4 uptake was in agreement with the dynamics of immune cell infiltration during the inflammatory reaction. These results suggest that 68Ga-WRW4 is a promising PET tracer suitable for the noninvasive detection of FPR2 expression and for monitoring inflammatory activity in inflammation-bearing mice.


Assuntos
Radioisótopos de Gálio , Receptores de Formil Peptídeo , Animais , Linhagem Celular Tumoral , Radioisótopos de Gálio/química , Inflamação/diagnóstico por imagem , Camundongos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/química
9.
Phys Rev Lett ; 127(13): 130503, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34623828

RESUMO

In almost all quantum applications, one of the key steps is to verify that the fidelity of the prepared quantum state meets expectations. In this Letter, we propose a new approach solving this problem using machine-learning techniques. Compared to other fidelity estimation methods, our method is applicable to arbitrary quantum states, the number of required measurement settings is small, and this number does not increase with the size of the system. For example, for a general five-qubit quantum state, only four measurement settings are required to predict its fidelity with ±1% precision in a nonadversarial scenario. This machine-learning-based approach for estimating quantum state fidelity has the potential to be widely used in the field of quantum information.

10.
J Am Chem Soc ; 142(20): 9169-9174, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32363870

RESUMO

Crystalline porous materials such as covalent organic frameworks (COFs) are advanced materials to tackle challenges of catalysis and separation in industrial processes. Their synthetic routes often require elevated temperatures, closed systems with high pressure, and long reaction times, hampering their industrial applications. Here we use a traditionally unperceived strategy to assemble highly crystalline COFs by electron beam irradiation with controlled received dosage, contrasting sharply with the previous observation that radiation damages the crystallinity of solids. Such synthesis by electron beam irradiation can be achieved under ambient conditions within minutes, and the process is amendable for large-scale production. The intense and targeted energy input to the reactants leads to new reaction pathways that favor COF formation in nearly quantitative yield. This strategy is applicable not only to known COFs but also to new series of flexible COFs that are difficult to obtain using traditional methods.

11.
Opt Express ; 28(12): 18449-18455, 2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-32680043

RESUMO

Integrated photonics has the advantages of miniaturization, low cost, and CMOS compatibility, and it provides a stable, highly integrated, and practical platform for quantum key distribution (QKD). While photonic integration of optical components has greatly reduced the overall cost of QKD systems, single-photon detectors (SPDs) have become the most expensive part of a practical QKD system. In order to circumvent this obstacle and make full use of SPDs, we have designed and fabricated a QKD receiver chip for multiple users. Our chip is based on a time-division multiplexing technique and makes use of a single set of SPDs to support up to four users' QKD. Our proof-of-principle chip-based QKD system is capable of producing an average secret key rate of 13.68 kbps for four users with a quantum bit error rate (QBER) as low as 0.51% over a simulated distance of 20 km in fiber. Our result clearly demonstrates the feasibility of multiplexing SPDs for setting QKD channels with different users using photonic integrated chip and may find applications in the commercialization of quantum communication technology.

12.
BMC Cancer ; 20(1): 54, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969123

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) with hilar bile duct tumor thrombus (HBDTT) often mimic hilar cholangiocarcinoma (hilar CC). The purpose of this study is to analyze the Computed Tomography (CT) characteristics of HCC with HBDTT and to identify imaging features to aid its differentiation from hilar CC on enhanced CT. METHODS: We retrospectively identified 58 cases with pathologically proved HCC with HBDTT between 2011 and 2018. Seventy-seven cases of pathologically proven hilar CCs were selected during the same period. The clinical features and CT findings of the two groups were reviewed and compared. RESULTS: HCC with HBDTTs are more commonly found in men (87.9% vs 63.6%, p = 0.001) with lower age of onset (49.84 vs 58.61 years; p < 0.001) in comparison to hilar CCs. Positive correlation were identified between HCC with HBDTTs and chronic HBV infection (72.4% vs 11.7%; p <  0.001), increased serum AFP (67.2% vs 1.3%; p <  0.001), CA19-9 level (58.6% vs 85.7%; p <  0.001) and CEA level (3.4% vs 29.9%; p = 0.001), parenchymal lesion with intraductal lesion (100% vs 18.2%; p <  0.001), washout during the portal venous phase (84.5% vs 6.5%; p <  0.001), thickened bile duct wall (8.6% vs 93.5%; p <  0.001), intrahepatic vascular embolus (44.8% vs 7.8%; p <  0.001), splenomegaly (34.5% vs 2.6%, p <  0.001). A scoring system consisting of the five parameters obtained from characteristics mentioned above was trialed. The sensitivity and specificity for diagnosing HCC with HBDTT were 96.39, 100 and 92.5% respectively when the total score was 2 or more. CONCLUSIONS: HCC with HBDTTs are often distinguishable from hilar CCs based on washout during portal venous phase without thickened bile duct wall. HBV infection and serum AFP level facilitate the differentiation.


Assuntos
Neoplasias dos Ductos Biliares/diagnóstico por imagem , Carcinoma Hepatocelular/diagnóstico por imagem , Tumor de Klatskin/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Trombose/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos de Pesquisa , Estudos Retrospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
13.
Arch Virol ; 165(7): 1667-1670, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32328855

RESUMO

In this study, we report the molecular characterization of a novel positive-sense single-stranded RNA (+ssRNA) mycovirus from Botryosphaeria dothidea strain G91, which we name "Botryosphaeria dothidea botourmiavirus 1" (BdBOV-1). The complete genome of BdBOV-1 is 2547 nucleotides (nt) long, contains one open reading frame (ORF) potentially encoding an RNA-dependent RNA polymerase (RdRp), and shows a close relationship to mycoviruses of the family Botourmiaviridae. Phylogenetic analysis based on the RdRp sequences confirmed that BdBOV-1 clustered together with the members of the family Botourmiaviridae. To the best of our knowledge, this is the first report of a +ssRNA mycovirus infecting B. dothidea.


Assuntos
Ascomicetos/virologia , Micovírus/genética , Micovírus/isolamento & purificação , Vírus de RNA/isolamento & purificação , Ascomicetos/fisiologia , Micovírus/classificação , Genoma Viral , Fases de Leitura Aberta , Filogenia , Doenças das Plantas/microbiologia , Vírus de RNA/classificação , Vírus de RNA/genética , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo
14.
J Environ Manage ; 265: 110511, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32275241

RESUMO

Nonferrous metal mining activities produce enormous amounts of tailings that contain high concentrations of toxic chemicals threatening human health and the environment. This risk could be alleviated using remediation agents such as biochar, as proposed by others. However, contradictory evidence indicates that biochar can increase or sometimes decrease bioavailable concentrations depending on the selection of metal(loid)s in mine tailings. Here three biochars derived from different raw stocks were used to treat mine tailings samples. Chemical analyses indicated that all biochars favored the stabilization of Cd, Cr, Cu, Pb, and Zn, as well as the mobilization of As and Sb. The barley root elongation bioassay showed that the tailings toxicity was only partially diminished (up to 55.8%) or even elevated (up to 20.7%) by biochar treatment. Similar results were also observed from microbial enzyme assays (increased up to 28.3% or decreased up to 24.0%). Further analyses showed that these toxic effects correlated well with the relative toxicity index (R2 = 0.66 to 0.88). Toxicity testing coupled with the use of a toxicity prediction model presented here suggested that the release of As and Sb from tailings compromised the favorable effects of biochar treatment on toxic cationic metals. Such information is of paramount importance when taking countermeasures for improving bioremediation technologies.


Assuntos
Metais Pesados , Poluentes do Solo , Carvão Vegetal , Metais , Mineração
15.
Eur Radiol ; 29(5): 2272-2282, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30547202

RESUMO

PURPOSE: To investigate the feasibility of prediction for targeted therapy-related gene expression in hepatocellular carcinoma (HCC) using preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: Ninety-one patients (81 men, mean age 53.9 ± 12 years) with solitary HCC who underwent preoperative enhanced MRI were retrospectively analyzed. Features including tumor size, signal homogeneity, tumor capsule, tumor margin, intratumoral vessels, peritumor enhancement, peritumor hypointensity, signal intensity ratio on DWI, T1 relaxation times, and the reduction rate between pre- and post-contrast enhancement images were assessed. The operation and histopathological evaluation were performed within 2 weeks after MRI examination (mean time 7 days). The expression levels of BRAF, RAF1, VEGFR2, and VEGFR3 were evaluated. The associations between these imaging features and gene expression levels were investigated. RESULTS: Tumor incomplete capsules or non-capsules (p = 0.001) and intratumoral vessels (p = 0.002) were significantly associated with BRAF expression, and tumor incomplete capsules or non-capsules (p = 0.001) and intratumoral vessels (p = 0.013) with RAF1 expression. There was no significant association between the expression of VEGFR2, VEGFR3, and all examined MRI features. Multivariate logistic regression showed that incomplete tumor capsule (p = 0.002) and non-capsule (p = 0.004) were independent risk factors of HCC with high BRAF expression; incomplete tumor capsule (p < 0.001) and non-capsule (p = 0.040) were independent risk factors of HCC with high RAF1 expression. CONCLUSION: The presence of incomplete capsule or intratumoral vessels and the absence of capsule are potential indicators of high BRAF and RAF1 expression. Gadoxetic acid-enhanced MRI may facilitate the choice of gene therapy for patients with HCC. KEY POINTS: • Incomplete tumor capsule and non-capsule were independent risk factors of HCC with high BRAF and RAF1 expression. • The presence of intratumoral vessels was a potential indicator of high BRAF and RAF1 expression. • Gadoxetic acid-enhanced MRI may be a predictor of efficacy of treatment with sorafenib.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Imageamento por Ressonância Magnética , Sorafenibe/uso terapêutico , Adulto , Idoso , Carcinoma Hepatocelular/patologia , Meios de Contraste , Estudos de Viabilidade , Feminino , Gadolínio DTPA , Humanos , Aumento da Imagem/métodos , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-raf/genética , Estudos Retrospectivos , Fatores de Risco , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/genética
16.
Ecotoxicol Environ Saf ; 173: 203-213, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-30772710

RESUMO

According to the novel weapons hypothesis, root exudates are the inhibition factors for native species growth and development through invasive plants. It is hypothesized that antioxidant system (AOS) presents an effective role in plant defense system. The allelopathy indexes of P. multifida gametophyte biomass and sporogonium conversions rates turn negative with the dose and time effects, and the synthetical allelopathic effect index was -55.07% at 100% treatments under root exudates treatments. Under transmission electron microscopy, the cell structures turn burry. Next, AOS and programmed cell death (PCD) were tested in this study. In AOS, strong activities of superoxide dismutase, catalase, glutathione reductase and glutathione S-transferase (GST) were identified in gametophyte cells under the treatments, as well as the contents of glutathione, ascorbic acid and reduced ascorbate, while GPX activity decreased. Based on the input (SOD activity) and the output (GST activity) of antioxidant system, and the decreasing system control would be a reason leading gametophyte death under root exudates. At day 10, PCD would get its peak of 46.93% at 100% root exudates. We found a dynamic balance of PCD and AOS under the exudates treatments. We detected hexadecanoic acid, ethylene glycol and undecane are three major chemicals in root exudates. Our results provide a reference of AOS and PCD working under root exudates treatments in plants and offer novel strategy for the native species protection and invasion plants control in environment science.


Assuntos
Bidens , Raízes de Plantas/química , Pteris , Alelopatia , Ácido Ascórbico/metabolismo , Biomassa , Catalase/metabolismo , Morte Celular , Células Germinativas Vegetais , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Superóxido Dismutase/metabolismo
17.
Arch Orthop Trauma Surg ; 138(4): 515-525, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29380050

RESUMO

INTRODUCTION: Accurate anatomic graft tunnel positioning is essential for the successful application of anatomic anterior cruciate ligament (ACL) reconstruction. The accurate insertion of the tibial tunnel (TT) remains challenging. Here, we explored a novel strategy of patient-specific drill template (PDT) for the placement of TT in ACL reconstruction and assessed its efficacy and accuracy. MATERIALS AND METHODS: TT placement was randomized and performed by use of the PDT technique in 40 patients (PDT group) and the conventional arthroscopic technique in 38 patients (Arthroscopic group). After surgery, the deviations at the center point of the ACL tibial attachment area and radiological TT positioning were assessed in both groups. The preoperative and follow-up examinations included pivot-shift testing, KT-1000 arthrometer testing, the Lysholm and International Knee Documentation Committee scales were used to compare the knee stability and the functional state. RESULTS: The ideal center points achieved in the PDT group were more precise than that in the arthroscopic group (p < 0.001). Radiological TT positioning performed by use of the PDT technique was more accurate than that by the arthroscopic technique (p = 0.027). Statistical differences could not be found between the groups in terms of the pivot-shift test, KT-1000 arthrometer laxity measurements, the Lysholm or International Knee Documentation Committee scales. Both groups improved at follow-up compared with the preoperative assessment in terms of the pivot-shift test, the laxity tests, and scoring scales. CONCLUSIONS: The novel PDT strategy could provide more accurate TT positioning than the traditional arthroscopic technique in ACL reconstruction. However, functional scales and stability tests gave similar results in the PDT and the standard techniques. LEVEL OF EVIDENCE: I.


Assuntos
Reconstrução do Ligamento Cruzado Anterior , Tíbia/cirurgia , Reconstrução do Ligamento Cruzado Anterior/efeitos adversos , Reconstrução do Ligamento Cruzado Anterior/métodos , Reconstrução do Ligamento Cruzado Anterior/estatística & dados numéricos , Artroscopia , Humanos , Resultado do Tratamento
18.
Inorg Chem ; 56(5): 2481-2489, 2017 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-28199094

RESUMO

Two novel POM-based inorganic-organic hybrids, [Cu6II(2,2'-bipy)6(Mo6O22)(SiW12O40)]n (1), and {[Cu6II(ppz)6(H2O)5(MoO4)(SiW12O40)]·4H2O}n (2) (2,2'-bipy = 2,2'-bipyridine, Hppz = 3-(pyrid-2-yl)pyrazole), have been constructed from heteropolytungstates and molybdates. Two compounds have been identified by single crystal X-ray diffraction, elemental analysis, and FT-IR. Compound 1 shows a 1D (one-dimensional) chain structure constructed from classical Keggin heteropolytungstate [SiW12O40]4- clusters and [Cu6(2,2'-bipy)6] modified isopolymolybdates [Mo6O22]8-. Compound 2 also represents a 1D chain-like motif built from classical Keggin heteropolytungstate [SiW12O40]4- clusters and [Cu8(ppz)6(H2O)5] modified molybdates MoO42-. Compound 1 represents the first example of POM-based inorganic-organic hybrid with mixed heteropolytungstates and isopolymolybdates. ESI-MS (electrospray ionization mass spectrometry) technique was employed to reveal the species and their evolutions in the hydrothermal reaction, whereby trivacant [SiW9] building block gradually transforms to classical Keggin [SiW12] during assembly process. Furthermore, the electrocatalytic and magnetic properties were discussed in details.

19.
J Appl Toxicol ; 37(9): 1021-1029, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28466983

RESUMO

Deoxynivalenol (DON) is one of the most important mycotoxins in cereal-based foods or other food productions, produced by Fusarium species. Because of the high occurrence of DON in food combined with vast consumption of cereals and grain worldwide, the DON-contaminated food is a very harmful factor for human and animal health. DON has been reported to induce anorexia at lower or chronic doses in animal models. However, further researches for DON-induced anorexia are limited. Previous publications demonstrated a close link between Bacteroidetes and Firmicutes, two kinds of gut microbiota, with weight loss and the effect of low administration of DON on neurotransmitters in the frontal cortex, cerebellum, hypothalamus, hippocampus and pons/medulla. These data are similar to other studies, which show selective 5HTα receptor agonists apparently causing hyperphagia whereas 5HT1ß agonists appear to induce anorexia. Thus, the neurochemical effects of lower DON exposure can be as a result of peripheral toxicological events such as emesis, which overwhelmed its more subtle feed refusal activity. Besides, changes in the microbiota have an impact on stress-related behaviors like anxiety and depression, which can lead to weight loss through decreased feed intake. Gut dysbiosis is also associated with brain dysfunction and with behavioral changes. These conclusions illustrate as well a potential explanation for DON-induced anorexia.In this review, we summarize information about DON-induced anorexia from previous studies and provide our opinion for future investigations that could establish a link between gut microbiota, neurotransmitters, anorexia and weight loss under the DON exposure. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Anorexia/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Tricotecenos/toxicidade , Animais , Anorexia/induzido quimicamente , Dieta , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Comportamentos Relacionados com a Saúde , Humanos , Neurotransmissores/farmacologia , Peptídeos/metabolismo , Serotonina/metabolismo , Redução de Peso/efeitos dos fármacos
20.
Antonie Van Leeuwenhoek ; 108(6): 1365-1372, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26377575

RESUMO

A novel filamentous actinobacterium, designated strain DHS C013(T), was isolated from limestone collected in Guizhou Province, South-west China. Morphological and chemotaxonomic characteristics of the strain support its assignment to the genus Lentzea. Phylogenetic analyses showed that strain DHS C013(T) is closely related to Lentzea jiangxiensis FXJ1.034(T) (98.7 % 16S rRNA gene similarity) and Lentzea flaviverrucosa 4.0578(T) (98.0 % 16S rRNA gene similarity), but it can be distinguished from these strains based on low levels of DNA:DNA relatedness (~44 and ~37 %, respectively). Physiological and biochemical tests also allowed phenotypic differentiation of the novel strain from these closely related species. On the basis of the evidence presented here, strain DHS C013(T) is concluded to represent a novel species of the genus Lentzea, for which the name Lentzea guizhouensis sp. nov. is proposed. The type strain is DHS C013(T) (=KCTC 29677(T) = CGMCC 4.7203(T)).


Assuntos
Actinobacteria/classificação , Actinobacteria/isolamento & purificação , Microbiologia Ambiental , Actinobacteria/genética , Actinobacteria/fisiologia , Técnicas de Tipagem Bacteriana , Carbonato de Cálcio , China , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
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