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1.
Molecules ; 26(22)2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34833899

RESUMO

Although various geochemical and geophysical investigations have already indicated a great resource potential in the Xisha area of the South China Sea, the origin of organic matter and molecular evidence for tracing the migration of hydrocarbons from deep petroleum reservoirs are still lacking. In this study, systematic organic geochemical analyses, including bulk organic matter parameters and lipid biomarkers were performed for deep sediments from two cores. The C/N ratios and δ13C and δ15N values of organic matter in most of the samples, together with the maxima of short-chain n-alkanoic acids and mid-chain n-alkanols, high abundances of monounsaturated fatty acids C18:1ω9 and C22:1ω13, jointly indicate the dominance of marine organic matter. n-Alkanes in sediments from core GMGS4-XH-W06B are characterized by small unresolved complex mixture (UCMs) humps, high odd/even predominance (OEP) and carbon preference index (CPI) values, clearly exhibiting characteristics of modern sediments. However, the sediments for core GMGS4-XH-W03B are featured with big UCMs, associated with OEP and CPI values around 1.0, showing signatures of petroleum hydrocarbons from high maturity sources. Considering the geologic background, the biomarker signatures are solid evidence for indicating the existence of underlying petroleum reservoirs, and may provide the valuable information for assessing the hydrocarbon resources in the Xisha area.

2.
Molecules ; 24(2)2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30634712

RESUMO

Humic substances in soil are considered to be an alternative food to the tender plant roots for Thitarodes larvae in the habitats of Ophiocordyceps sinensis in the Qinghai-Tibetan Plateau. However, there is no report involving the evaluation of their potential as a food source from the composition and structure of habitat soils. In this work, the composition and structure of humic substances in habitat soils from the Sejila Mountain, Tibet were characterized by diverse techniques for evaluating the nutritional value and possibility of humus as the food source for Thitarodes larvae. Fourier transform infrared spectroscopy revealed that humic acid may possess superior ability to provide the molecular segments for biosynthesizing lipids more than other humic fractions. Combining with the analysis of solid-state 13C nuclear magnetic resonance spectrum, the fractions of hydrophobic fulvic acid and hydrophilic fulvic acid are further considered as a potential food source for Thitarodes larvae. Overall, humic substances in habitat soils are rich in the molecular segments for biosynthesizing lipids and other important nutrients, which may provide the energy and material sources for maintaining the survival of Thitarodes larvae in the absence of tender plant roots, particularly in the annual cold winter. Combining with the evidence of physico-chemical parameters of habitat soils and stable carbon isotopic composition of major tender plant roots in the Sejila Mountain, the composition and structure of humic substances in habitat soils may provide a novel idea for the eco-friendly and semi-wild cultivation of Thitarodes larvae with low cost.


Assuntos
Substâncias Húmicas/análise , Hypocreales/crescimento & desenvolvimento , Lepidópteros/fisiologia , Solo/química , Ração Animal , Animais , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Ecossistema , Larva/crescimento & desenvolvimento , Espectroscopia de Infravermelho com Transformada de Fourier , Tibet
3.
Chem Biodivers ; 15(1)2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28834279

RESUMO

Norendoxifen, an active metabolite of tamoxifen, is a potent aromatase inhibitor. Little information is available regarding production of norendoxifen in vitro. Here, we conducted a series of kinetic and inhibition studies in human liver microsomes (HLMs) and expressed P450s to study the metabolic disposition of norendoxifen. To validate that norendoxifen was the metabolite of endoxifen, metabolites in HLMs incubates of endoxifen were measured using a HPLC/MS/MS method. To further probe the specific isoforms involved in the metabolic route, endoxifen was incubated with recombinant P450s (CYP 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4, 3A5 and CYP4A11). Formation rates of norendoxifen were evaluated in the absence and presence of P450 isoform specific inhibitors using HLMs. The peak of norendoxifen was found in the incubations consisting of endoxifen, HLMs, and cofactors. The retention times of norendoxifen, endoxifen, and the internal standard (diphenhydramine) were 7.81, 7.97, and 5.86 min, respectively. The Km (app) and Vmax (app) values of norendoxifen formation from endoxifen in HLM was 47.8 µm and 35.39 pmol min-1 mg-1 . The apparent hepatic intrinsic clearances of norendoxifen formation were 0.74 µl mg-1 min. CYP3A5 and CYP2D6 were the major enzymes capable of norendoxifen formation from endoxifen with the rates of 0.26 and 0.86 pmol pmol-1 P450 × min. CYP1A2, 3A2, 2C9, and 2C19 also contributed to norendoxifen formation, but the contributions were at least 6-fold lower. One micromolar ketoconazole (CYP3A inhibitor) showed an inhibitory effect on the rates of norendoxifen formation by 45%, but 1 µm quinidine (CYP2D6 inhibitor) does not show any inhibitory effect. Norendoxifen, metabolism from endoxifen by multiple P450s that including CYP3A5.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Tamoxifeno/análogos & derivados , Humanos , Cinética , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Tamoxifeno/química , Tamoxifeno/metabolismo
4.
J Med Genet ; 53(9): 624-33, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27247351

RESUMO

BACKGROUND: Dentin dysplasia I (DDI) is a genetically heterogeneous autosomal-dominant disorder characterised by rootless teeth with abnormal pulpal morphology, the aetiology of which presents as genetically heterogeneous. METHODS AND RESULTS: Using a cohort of a large Chinese family with 10 patients with DDI, we mapped to a 9.63 Mb candidate region for DDI on chromosome 18q21.2-q21.33. We then identified a mutation IVS7+46C>G which resulted in a novel donor splice site in intron 7 of the VPS4B gene with co-segregation of all 10 affected individuals in this family. The aberrant transcripts encompassing a new insert of 45 bp in size were detected in gingival cells from affected individuals. Protein structure prediction showed that a 15-amino acid insertion altered the ATP-binding cassette of VPS4B. The mutation resulted in significantly reduced expression of mRNA and protein and altered subcellular localisation of VPS4B, indicating a loss of function of VPS4B. Using human gingival fibroblasts, the VPS4B gene was found to act as an upstream transducer linked to Wnt/ß-catenin signalling and regulating odontogenesis. Furthermore, knockdown of vps4b in zebrafish recapitulated the reduction of tooth size and absence of teeth similar to the tooth phenotype exhibited in DDI index cases, and the zebrafish mutant phenotype could be partially rescued by wild-type human VPS4B mRNA. We also observed that vps4b depletion in the zebrafish negatively regulates the expression of some major genes involved in odontogenesis. CONCLUSIONS: This study identifies VPS4B as a disease-causing gene for DDI, which is one of the important contributors to tooth formation, through the Wnt/ß-catenin signalling pathway.


Assuntos
Adenosina Trifosfatases/genética , Displasia da Dentina/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Mutação/genética , Splicing de RNA/genética , ATPases Associadas a Diversas Atividades Celulares , Animais , Povo Asiático/genética , Sequência de Bases , Feminino , Fibroblastos/metabolismo , Humanos , Masculino , Odontogênese/genética , Linhagem , Sítios de Splice de RNA/genética , RNA Mensageiro/genética , Via de Sinalização Wnt/genética , Peixe-Zebra/genética , beta Catenina/genética
5.
Biom J ; 59(4): 746-766, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28319254

RESUMO

We develop a Bayesian approach to subgroup analysis using ANOVA models with multiple covariates, extending an earlier work. We assume a two-arm clinical trial with normally distributed response variable. We also assume that the covariates for subgroup finding are categorical and are a priori specified, and parsimonious easy-to-interpret subgroups are preferable. We represent the subgroups of interest by a collection of models and use a model selection approach to finding subgroups with heterogeneous effects. We develop suitable priors for the model space and use an objective Bayesian approach that yields multiplicity adjusted posterior probabilities for the models. We use a structured algorithm based on the posterior probabilities of the models to determine which subgroup effects to report. Frequentist operating characteristics of the approach are evaluated using simulation. While our approach is applicable in more general cases, we mainly focus on the 2 × 2 case of two covariates each at two levels for ease of presentation. The approach is illustrated using a real data example.


Assuntos
Análise de Variância , Biometria/métodos , Modelos Estatísticos , Algoritmos , Teorema de Bayes , Humanos , Probabilidade
6.
J Pak Med Assoc ; 67(9): 1415-1419, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28924285

RESUMO

The systematic review and meta-analysis of published randomised controlled trials (RCTs) was conducted to review the effectiveness of current chemopreventive agents in the treatment of oral leukoplakia lesions (OPLs) and prevention of their progression to oral cancer. Material was identified through a retrospective literature search of the electronic PubMed database, Embase and Cochrane Library between 2008 and 2016.Eight RCTs were included for systematic review. The pooled estimate showed a 14% greater chance of responding for those randomised to interventions compared with placebo (Risk Ratio [RR] 1.14, 95% confidence interval [CI] 0.72 to 1.81). The CI from individual studies overlapped. The results suggested that there were no significant differences in comparing clinical responses between chemopreventive agents with placebo in treatment of OPLs. It is time to investigate new agents for oral cancer chemoprevention.


Assuntos
Antineoplásicos/uso terapêutico , Leucoplasia Oral/tratamento farmacológico , Neoplasias Bucais/prevenção & controle , Lesões Pré-Cancerosas/tratamento farmacológico , Quimioprevenção , Cloridrato de Erlotinib/uso terapêutico , Humanos , Isotretinoína/uso terapêutico , Provitaminas/uso terapêutico , Chá , Resultado do Tratamento , Vitamina A/uso terapêutico , Vitaminas/uso terapêutico , beta Caroteno/uso terapêutico
7.
Bioorg Med Chem ; 24(21): 5400-5409, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27647367

RESUMO

The design and synthesis of dual aromatase inhibitors/selective estrogen receptor modulators (AI/SERMs) is an attractive strategy for the discovery of new breast cancer therapeutic agents. Previous efforts led to the preparation of norendoxifen (4) derivatives with dual aromatase inhibitory activity and estrogen receptor binding activity. In the present study, some of the structural features of the potent AI letrozole were incorporated into the lead compound (norendoxifen) to afford a series of new dual AI/SERM agents based on a symmetrical diphenylmethylene substructure that eliminates the problem of E,Z isomerization encountered with norendoxifen-based AI/SERMs. Compound 12d had good aromatase inhibitory activity (IC50=62.2nM) while also exhibiting good binding activity to both ER-α (EC50=72.1nM) and ER-ß (EC50=70.8nM). In addition, a new synthesis was devised for the preparation of norendoxifen and its analogues through a bis-Suzuki coupling strategy.


Assuntos
Inibidores da Aromatase/síntese química , Inibidores da Aromatase/farmacologia , Aromatase/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Estilbenos/síntese química , Estilbenos/farmacologia , Inibidores da Aromatase/química , Sítios de Ligação/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Células MCF-7 , Estrutura Molecular , Ligação Proteica , Estilbenos/química , Relação Estrutura-Atividade
8.
Cell Biochem Biophys ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38976102

RESUMO

As a common inflammatory bowel disease, ulcerative colitis (UC) is featured with inflammation, oxidative damage, and the impairment of intestinal mucosal barrier, which bring threat to patients' quality of live. Hinesol, derived from Atractylodes lancea, is a unique sesquiterpenoid. Our study proposed to survey the effects and mechanism of hinesol in UC. UC mouse model was constructed using dextran sulfate sodium (DSS). Lipopolysaccharide (LPS) was applied for RAW264.7 cells stimulation to construct cell inflammatory model. The changes of disease activity index (DAI), body weight, colon length, and intestinal pathology in mice were analyzed to estimate the severity of colitis. Enzyme-linked immunosorbent assay was applied to check the changes of interleukin (IL)-1ß, IL-18, IL-6, and tumor necrosis factor (TNF)-α. The levels of myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione peroxidase (GSH-px), catalase (CAT), and malondialdehyde (MDA) were estimated by corresponding reagent kit. The changes of phosphorylated (p)-NF-κB P65, and p-IκBα, ZO-1, Occludin, Claudin-1, Src, XCL1, CCL2, and CXCL16 protein were examined using western blot. Flow cytometry and cell counting kit-8 assay were utilized for assessment of cell apoptosis and viability. We found that DSS reduced mice body weight, increased DAI, shorten colon length, and led to severe enteric mucosal injury, while hinesol improved the above symptoms induced by DSS. In DSS mice, hinesol raised the levels of ZO-1, Occludin, Claudin-1, SOD, GSH-px, and CAT and decreased the levels of TNF-α, IL-18, IL-1ß, IL-6, MPO, and MDA. Additionally, in DSS mice and LPS-stimulated RAW264.7 cells, hinesol inhibited the high expression of Src, XCL1, CCL2, CXCL16, p-NF-κB P65, and p-IκBα. The molecular docking showed that there was a good interaction between hinesol and Src. Moreover, in LPS-stimulated RAW 264.7 cells, Src overexpression partially reversed the inhibition of hinesol on cell apoptosis, pro-inflammatory factors, and oxidative stress. In conclusion, hinesol alleviated DSS-induced colitis, which might have a bearing on the inhibition of Src-mediated NF-κB and chemokine signaling pathway.

9.
Water Res ; 251: 121151, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38246075

RESUMO

The discovery of complete ammonium oxidation (comammox) has subverted the traditional perception of two-step nitrification, which plays a key role in achieving biological nitrogen removal from wastewater. Floccular sludge-based treatment technologies are being applied at the majority of wastewater treatment plants in service where detection of various abundances and activities of comammox bacteria have been reported. However, limited efforts have been made to enrich and subsequently characterize comammox bacteria in floccular sludge. To this end, a lab-scale sequencing batch reactor (SBR) in the step-feeding mode was applied in this work to enrich comammox bacteria through controlling appropriate operational conditions (dissolved oxygen of 0.5 ± 0.1 g-O2/m3, influent ammonium of 40 g-N/m3 and uncontrolled longer sludge retention time). After 215-d operation, comammox bacteria gradually gained competitive advantages over counterparts in the SBR with a stable nitrification efficiency of 92.2 ± 2.2 %: the relative abundance of Nitrospira reached 42.9 ± 1.3 %, which was 13 times higher than that of Nitrosomonas, and the amoA gene level of comammox bacteria increased to 7.7 ± 2.1 × 106 copies/g-biomass, nearly 50 times higher than that of conventional ammonium-oxidizing bacteria. The enrichment of comammox bacteria, especially Clade A Candidatus Nitrospira nitrosa, in the floccular sludge led to (i) apparent affinity constants for ammonium and oxygen of 3.296 ± 0.989 g-N/m3 and 0.110 ± 0.004 g-O2/m3, respectively, and (ii) significantly low N2O and NO production, with emission factors being 0.136 ± 0.026 % and 0.023 ± 0.013 %, respectively.


Assuntos
Compostos de Amônio , Esgotos , Esgotos/microbiologia , Amônia , Bactérias , Nitrificação , Oxirredução , Oxigênio , Filogenia , Archaea
10.
Drug Metab Dispos ; 41(9): 1715-20, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23824607

RESUMO

Aromatase catalyzes the conversion of testosterone to estradiol and is the main source of endogenous estrogen in postmenopausal women. Aromatase inhibitors (AIs) are used to treat postmenopausal women with hormone receptor-positive breast cancer. Norendoxifen [4-(1-(4-(2-aminoethoxy)phenyl)-2-phenylbut-1-en-1-yl)phenol], an active metabolite of the selective estrogen receptor modulator tamoxifen, has been shown to be a potent competitive AI, with an IC50 of 90 nM. To obtain data relevant to the clinical use of norendoxifen, the primary objective of this study was to investigate norendoxifen's inhibitory capability on enzymes related to drug-drug interactions. We determined the inhibitory ability of norendoxifen against important drug-metabolizing cytochrome P450 enzymes, including CYP1A2, CYP2A6, CYP3A4, CYP3A5, and CYP2C19, to establish the potency of norendoxifen as a potential cause of drug-drug interactions. A second objective was to determine the effects of E- and Z-norendoxifen on the inhibition of these enzymes to further characterize the isomers' selectivity. The inhibitory abilities of E-, mixed, and Z-norendoxifen against recombinant aromatase (CYP19), CYP1A2, CYP3A4, CYP3A5, and CYP2C19 were tested using microsomal incubations. Mixed norendoxifen inhibited these enzymes with Ki values of 70 ± 9, 76 ± 3, 375 ± 6, 829 ± 62, and 0.56 ± 0.02 nM, respectively. E-Norendoxifen had a 9.3-fold-higher inhibitory ability than Z-norendoxifen against CYP19, while E- and Z-norendoxifen had similar potencies against CYP1A2, CYP3A4, CYP3A5, and CYP2C19. These results suggest that norendoxifen is able to act as a potent AI, and that its E-isomer is 9.3-fold more potent than the Z-isomer.


Assuntos
Inibidores das Enzimas do Citocromo P-450 , Tamoxifeno/análogos & derivados , Inibidores da Aromatase/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Interações Medicamentosas , Humanos , Estereoisomerismo , Tamoxifeno/farmacologia
11.
Ear Nose Throat J ; 102(3): 151-152, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33683978

RESUMO

Gingival carcinoma is a common malignant tumor occurring in the anterior area of the mandible, which can be derived from the epithelium of gingival mucosa. Surgical extended resection is the main treatment of gingival cancer, which can lead to anterior mandibular defect including mouth floor and mandible and mucosa of lower lip. According to the size of the defect, the common repair method is free musculocutaneous flap with vascular pedicle or pedicle flap. We present a method of repairing mandibular anterior tooth defect with an island flap pedicled with the mental artery.


Assuntos
Retalhos de Tecido Biológico , Neoplasias Gengivais , Humanos , Soalho Bucal/cirurgia , Artérias , Mandíbula/cirurgia , Lábio
12.
Sci Total Environ ; 895: 165051, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37391158

RESUMO

The discovery of complete ammonium oxidation (comammox) has redefined the perception of the nitrification process which plays a vital part in biological nitrogen removal (BNR) from wastewater. Despite the reported detection or cultivation of comammox bacteria in biofilm or granular sludge reactors, limited attempts have been made to enrich or assess comammox bacteria in floccular sludge reactors with suspended growth of microbes, which are most extensively applied at wastewater treatment plants. Therefore, through making use of a comammox-inclusive bioprocess model reliably evaluated using batch experimental data with joint contributions of different nitrifying guilds, this work probed into the proliferation and functioning of comammox bacteria in two commonly-used floccular sludge reactor configurations, i.e., continuous stirred tank reactor (CSTR) and sequencing batch reactor (SBR), under mainstream conditions. The results indicated that compared with the studied SBR, the CSTR was observed to favor the enrichment of comammox bacteria through maintaining a sufficient sludge retention time (40-100 d) while avoiding an extremely low DO level (e.g., 0.05 g-O2/m3), irrespective of the varied influent NH4+-N of 10-100 g-N/m3. Meanwhile, the inoculum sludge was found to greatly influence the start-up process of the studied CSTR. By inoculating the CSTR with a sufficient amount of sludge, finally enriched floccular sludge with a high abundance of comammox bacteria (up to 70.5 %) could be rapidly obtained. These results not only benefitted further investigation and application of comammox-inclusive sustainable BNR technologies but also explained, to some extent, the discrepancy in the reported presence and abundance of comammox bacteria at wastewater treatment plants adopting floccular sludge-based BNR technologies.


Assuntos
Reatores Biológicos , Esgotos , Esgotos/microbiologia , Reatores Biológicos/microbiologia , Águas Residuárias , Nitrificação , Bactérias , Nitrogênio , Oxirredução , Amônia
13.
Tumour Biol ; 33(2): 495-505, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22134872

RESUMO

The growth, invasiveness, and metastasis of human cancers are not only determined by the cancer cells but also by their microenvironment. The purpose of this study was to extend our previous studies and to examine the cellular changes in tumor microenvironment (stroma) of esophageal squamous cell carcinomas (ESCCs). The proliferative activity, cellular components, and angiogenesis status in different compartments (non-tumor stroma, tumor stroma, and tumor periphery stroma) of ESCCs were evaluated by immunohistochemistry. The results revealed a hyperproliferative rate labeled by Ki-67 in stromal cells in tumor area as compared with that in stromal cells in non-tumor area, which resulted in the increased densities of myofibroblasts (labeled by smooth muscle actin (SMA)-alpha), lymphocytes (labeled by CD3), macrophages (labeled by CD68), and the activation of angiogenesis characterized by increased microvessel density (MVD) and the increased expression of the proangiogenic factors (vascular endothelial growth factor and interleukin 8) in the tumor stroma. Further analysis showed that the changes of stromal cell density were more significant in the area of periphery tumor stroma than that of stroma between tumor nests. Most cellular changes were significantly associated with lymph node involvement. Double immunohistochemistries with PCNA/CD3, PCNA/CD68, and PCNA/SMA-alpha revealed that these cells present in the ESCC tumor stroma had a proliferative capacity. The cells present in the tumor microenvironment of ESCCs were greatly activated, suggesting that microenvironmental components may be involved in the cancer growth and progression.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Esofágicas/metabolismo , Regulação Neoplásica da Expressão Gênica , Adulto , Idoso , Antígenos CD/biossíntese , Antígenos de Diferenciação Mielomonocítica/biossíntese , Complexo CD3/biossíntese , Proliferação de Células , Feminino , Fibroblastos/citologia , Humanos , Imuno-Histoquímica/métodos , Antígeno Ki-67/biossíntese , Linfócitos/citologia , Macrófagos/citologia , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica , Microambiente Tumoral
14.
Comput Intell Neurosci ; 2022: 1310194, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35463277

RESUMO

With the popularization of the Internet lifestyle and the innovation of learning methods, more and more online learning systems have emerged, allowing users to study in the system anytime and anywhere. While providing convenience to users, online learning systems also bring troubles to users, who cannot quickly find the resources they are interested in from the huge amount of learning resources. In this paper, we apply deep learning to an English online learning platform and analyze learners and learning contents by clustering algorithm and association rules. Based on this, a content organization system is developed using genetic algorithms, which is applied to the case of this paper to provide learners with personalized learning content. With the hope that the system can be extended to other online learning platforms in the future, three data mining techniques were selected to solve the problems found in the English online learning platform, and we designed how these techniques should be applied to the online learning platform. The first technique is the cluster mining technique, which is used to analyze learners' profiles, classify learners in different categories, provide them with personalized learning content, and organize group learning. The second technique is association rules, which is used to analyze the correlation between learning contents. For the adaptive student-teacher knowledge migration strategy, the teacher model can guide the student model to track online and migrate the task-specific knowledge to the online tracking student model through the network parameters. Finally, a case study is selected and the above design is applied to this case study, and the results are analyzed in detail. The data mining technology is applied to the English online learning platform, and an innovative English learning content organization system is developed. It is hoped that the results of this study will have some practical value for promotion and provide an idea for the construction of the online learning platform, and it is also expected that the idea can improve the quality of online learning to a certain extent. Specifically, the online student model is adaptively updated by the teacher model parameters and the online student model parameters together.


Assuntos
Aprendizado Profundo , Educação a Distância , Algoritmos , Análise por Conglomerados , Humanos , Estudantes
15.
Sci Rep ; 12(1): 9118, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35650280

RESUMO

For identifying the occurrence and extent of thermochemical sulfate reduction (TSR) reaction of natural gas and better understanding the chemical and carbon isotopic variations in natural gas reservoirs, high-pressure hydro-pyrolysis with a special designed apparatus was performed using natural gas and various amounts of MgSO4·7H2O at up to 360 °C. The yields, chemical and isotopic compositions of the gases produced during TSR and thermal cracking were measured. As the extent of TSR reaction increased, the concentrations of CH4, CO2 and H2S increased in a nonlinear way, while those of C2H6 and C3H8 decreased. According to the variation of gas content, the TSR reaction of alkane gases can be divided into an uncatalyzed and a catalyzed stage, which is different from previous studies that treated the TSR reaction of alkane gases as a non-autocatalytic reduction process. As the concentration of MgSO4·7H2O increased, the rate of TSR reaction with hydrocarbon gases increased. The concentrations of HSO4- and volume of aqueous phase could be responsible for the different TSR reaction rates in the catalyzed stage. The co-variation of ln(C1/C2) and ln(C2/C3) could be related to the TSR reaction of alkane gases. Our study provides clues for understanding the compositional variations in natural conditions.

16.
Bioresour Technol ; 356: 127307, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35569712

RESUMO

This work studied the impacts of key granule properties on the granular reactor performing partial nitritation/anammox from the modeling perspective. The results could guide not only future reliable modeling but also practical startup/operation of the reactor. To achieve high total nitrogen (TN) removal whilst avoiding significant N2O production, inoculated granules should be big and anammox-enriched. The optimum boundary layer thickness for maximum TN removal increased with the decreasing diffusivity of soluble components in the granule structure. Even though a thick boundary layer could protect anammox bacteria from elevated dissolved oxygen (DO) (e.g., 0.5 g-O2/m3) and obtain high TN removal (>90.0%) and low N2O production (<1.8%), even complete removal of the boundary layer would fail to provide sufficient substrate for anammox and therefore couldn't increase TN removal to 90.0% and decrease N2O production to <2.4% at insufficient DO (e.g., 0.3 g-O2/m3 in the presence of lifted influent NH4+ concentration).


Assuntos
Desnitrificação , Nitrogênio , Processos Autotróficos , Reatores Biológicos/microbiologia , Oxirredução , Esgotos/microbiologia
17.
Sci Rep ; 12(1): 196, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34997136

RESUMO

Diamondoid compounds are widely used to reflect thermal maturation of high mature source rocks or oils and oil cracking extents. However, diamondoids and thiadiamondoids were demonstrated to have newly been generated and decomposed in our hydrothermal pyrolysis of crude oil and TSR experiments. Our results show that adamantanes and diamantanes are generated primarily within the maturity range 0.48-2.1% and 1.2-3.0% EasyRo, respectively. Their formation is enhanced and the decomposition of diamantanes obviously lags at elevated temperatures compared with anhydrous experiments. MDI, EAI, DMAI-1, DMDI-2 may serve as reliable maturity proxies at > ca.1.0% EasyRo, and other isomerization indices (TMAI-1, TMAI-2 and DMAI-2) are effective for the highly mature organic matter at EasyRo > 2.0%. The extent of oil cracking (EOC) calculated from the broadly used (3- + 4-) MD method (Dahl et al. in Nature 399:54-56, 1999) is proven to overestimate, especially for highly cracked samples due to the new generation of (3- + 4-) MD. Still, it can be corrected using a new formula at < 3.0% EasyRo. Other diamondoid-related indices (e.g., EAI, DMDI-2, As/Ds, MAs/MDs, DMAs/DMDs, and DMAs/MDs) can also be used to estimate EOC. However, these indices cannot be applied to TSR-altered petroleum. TSR is experimentally confirmed to generate diamantanes and thiaadmantanes at 1.81% EasyRo likely via direct reactions of reduced S species with hydrocarbons and accelerate the decomposition of diamantanes at > 2.62% EasyRo compared with thermal chemical alteration (TCA). More studies are needed to assess specific mechanisms for the formation of thiadiamondoids under natural conditions.

18.
Water Res ; 220: 118665, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35640508

RESUMO

Integrating anammox with denitrifying anaerobic methane oxidation (DAMO) in the membrane biofilm reactor (MBfR) is a promising technology capable of achieving complete nitrogen removal from wastewater. However, it remains unknown whether reactor configurations featuring longitudinal gradients parallel to the membrane surface would affect the performance of the CH4-driven MBfR. To this end, this work aims to study the impacts of longitudinal heterogeneity potentially present in the gas and liquid phases on a representative CH4-driven MBfR performing anammox/DAMO by applying the reported modified compartmental modeling approach. Through comparing the modeling results of different reactor configurations, this work not only offered important guidance for better design, operation and monitoring of the CH4-driven MBfR, but also revealed important implications for prospective related modeling research. The total nitrogen removal efficiency of the MBfR at non-excessive CH4 supply (e.g., surface loading of ≤0.064 g-COD m-2 d-1 in this work) was found to be insensitive to both longitudinal gradients in the liquid and gas phases. Comparatively, the longitudinal gradient in the liquid phase led to distinct longitudinal biomass stratification and therefore played an influential role in the effective CH4 utilization efficiency, which was also related to the extent of reactor compartmentation considered in modeling. When supplied with non-excessive CH4, the MBfR is recommended to be designed/operated with both the biofilm reactor and the membrane lumen as plug flow reactors (PFRs) with co-current flow of wastewater and CH4, which could mitigate dissolved CH4 discharge in the effluent. For the reactor configurations with the biofilm reactor designed/operated as a PFR, multi-spot sampling in the longitudinal direction is needed to obtain a correct representation of the microbial composition of the MBfR.


Assuntos
Metano , Nitrogênio , Anaerobiose , Biofilmes , Reatores Biológicos , Desnitrificação , Oxirredução , Estudos Prospectivos , Águas Residuárias
19.
Nat Commun ; 13(1): 4349, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35896580

RESUMO

Small molecule kinase inhibitors (SMKIs) are being approved at a fast pace under expedited programs for anticancer treatment. In this study, we construct a multi-domain dataset from a total of 4638 patients in the registrational trials of 16 FDA-approved SMKIs and employ a machine-learning model to examine the relationships between kinase targets and adverse events (AEs). Internal and external (datasets from two independent SMKIs) validations have been conducted to verify the usefulness of the established model. We systematically evaluate the potential associations between 442 kinases with 2145 AEs and made publicly accessible an interactive web application "Identification of Kinase-Specific Signal" ( https://gongj.shinyapps.io/ml4ki ). The developed model (1) provides a platform for experimentalists to identify and verify undiscovered KI-AE pairs, (2) serves as a precision-medicine tool to mitigate individual patient safety risks by forecasting clinical safety signals and (3) can function as a modern drug development tool to screen and compare SMKI target therapies from the safety perspective.

20.
Medicine (Baltimore) ; 100(22): e23820, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34087818

RESUMO

ABSTRACT: This study aims to describe the occurrence, severity degree, and correlated risk factors of dental fluorosis among the 12-year-old schoolchildren of Jilin, China.We conducted a cross-sectional, observational, and descriptive study among 960 12-year-old schoolchildren in Jilin. The Dean index was utilized to evaluate the severity degree of dental fluorosis. A questionnaire was sent to the guardians of children. Community fluorosis index was measured to estimate the importance of enamel fluorosis for the whole population's public health. The logistic regression analysis was also utilized to identify the correlation between fluorotic teeth and the independent variables.Nine hundred sixty children were assessed. Among them, 480 (50%) were female. 30.5% of subjects had dental fluorosis, 7.19% had very mild dental fluorosis, 10.73% experienced mild dental fluorosis, 9.58% suffered moderate dental fluorosis, and 3.02% encountered severe dental fluorosis. The overall community fluorosis index was 0.73. The results of logistic regression showed that schoolchildren who brushed teeth more frequently (OR: 2.012, 95% CI 1.767-2.342), deficiency of parental supervision (OR: 4.219, 95% CI 3.887-4.573), and lived in rural areas (OR: 2.776, 95% CI 2.163-3.489) were more correlated with enamel fluorosis. Moreover, schoolchildren whose mothers or fathers were of high education level (OR: 0.336, 95% CI 0.217-0.413 and 0.346, 95% CI 0.113-0.512) and only child (OR: 0.378, 95% CI 0.213-0.415) were protective factors for dental fluorosis.In the Jilin province of China, the risk indicators for dental fluorosis include rural areas, more frequency of brushing, low educational background of parents, and deficiency of parental supervision.


Assuntos
Fluorose Dentária/epidemiologia , Escovação Dentária/estatística & dados numéricos , Criança , China/epidemiologia , Estudos Transversais , Índice CPO , Feminino , Humanos , Modelos Logísticos , Masculino , Características de Residência , Fatores de Risco , Índice de Gravidade de Doença , Fatores Socioeconômicos
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