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1.
Ultrason Sonochem ; 63: 104981, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32000052

RESUMO

The instability of allicin makes it easily decomposed into various organic sulfur compounds, resulting in significant decrease in biological activity. In this study, allicin was firstly extracted with water, then bound with whey protein isolates (WPI) which were pretreated by ultrasound to form conjugates, and the stability, water solubility and emulsibility of conjugates were as well investigated. The research results showed that there were no significant differences in the extraction yields of allicin from water, 40% and 80% ethanol. Appropriate frequency (20/40 kHz), power (50 W/L) and time (20 min) of ultrasonic pretreatments significantly increased (P < 0.05) the sulfhydryl groups content of WPI by 35.05% over control, causing improvement in binding ability of protein to allicin. The binding process of allicin-WPI displayed good fit with Elovich kinetic model (R2 = 0.9781). The mass retention rate of the conjugates (in 60% combination rate) with ultrasonic pretreating kept at 95.97% after 14 days of storage at 25 °C, whereas allicin's mass retention rate was only 61.79% at same storage condition. The water solubility of the prepared conjugates was significantly higher than allicin. And with optimal condition ultrasonic pretreatment of WPI, the conjugates showed the highest emulsifying capacity and emulsion stability (49.56 m2/g, 10.06 min). In conclusion, the ultrasonically pretreated allicin-WPI conjugates exhibited better stability, water solubility and emulsifying properties compared to allicin, this expands the application field of allicin.

2.
Cell Prolif ; 53(2): e12746, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31867863

RESUMO

Human high-temperature requirement protein 1 (HTRA1) is a member of serine proteases and consists of four well-defined domains-an IGFBP domain, a Kazal domain, a protease domain and a PDZ domain. HTRA1 is a secretory protein and also present intracellularly and associated with microtubules. HTRA1 regulates a broad range of physiological processes via its proteolytic activity. This review examines the role of HTRA1 in bone biology, osteoarthritis, intervertebral disc (IVD) degeneration and tumorigenesis. HTRA1 mediates diverse pathological processes via a variety of signalling pathways, such as TGF-ß and NF-κB. The expression of HTRA1 is increased in arthritis and IVD degeneration, suggesting that HTRA1 protein is attributed to cartilage degeneration and disease progression. Emerging evidence also suggests that HTRA1 has a role in tumorigenesis. Further understanding the mechanisms by which HTRA1 displays as an extrinsic and intrinsic regulator in a cell type-specific manner will be important for the development of HTRA1 as a therapeutic target.


Assuntos
Serina Peptidase 1 de Requerimento de Alta Temperatura A/metabolismo , Degeneração do Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/patologia , Neoplasias/metabolismo , Neoplasias/patologia , Sequência de Aminoácidos , Animais , Humanos , Disco Intervertebral/metabolismo , Alinhamento de Sequência , Transdução de Sinais/fisiologia , Temperatura
3.
Sci Total Environ ; 698: 134315, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31783453

RESUMO

Bioaerosol in the atmosphere plays a very important role in environment and public health. To forecast the bioaerosol concentration, the correlation between bioaerosol concentration and meteorological factors was discussed, and a Back Propagation (BP) neural network with Principal Component Analysis (PCA) method was utilized in this study. The proposed method works in three steps. The first step is to compute the correlation between bioaerosol concentration and meteorological factors, which consists of analyzing correlation and selecting meteorological factors applied to the study of forecast model. The second step is to use PCA analysis to reduce the dimensions of meteorological dataset. The third step is to use BP neural network, setting up, training BP neural network and proving the feasibility of forecast model included. The results of our model in forecasting bioaerosol concentration show 10.55% of average relative error, 2.80 pieces/L (pcs/L) of average absolute error, and 84.01 grade of forecast accuracy, providing a promising model for the forecasting of bioaerosol concentration.


Assuntos
Aerossóis/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental/métodos , Redes Neurais de Computação , Atmosfera , Conceitos Meteorológicos
4.
Food Chem ; 289: 609-615, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30955655

RESUMO

The effect of alkali concentration on the digestibility and absorption characteristics of rice residue protein isolates (RPI) and lysinoalanine (LAL) was studied. When NaOH concentration was 0.03 M, the in vitro digestibility of RPI reached a maximum, and when NaOH concentration was higher than 0.03 M, the in vitro digestibility decreased. Alkali treatment reduced the release of all amino acids, especially arginine, lysine, phenylalanine, tyrosine, cysteine, and threonine. LAL only released 2.65-9.28% of the total LAL content, which was mainly combined with longer peptide chains, and the molecular weight was mostly accumulated between 1000 Da and 3000 Da. The experimental model of rats in the small intestine perfusion showed that the high alkali concentration significantly reduced the absorption rate of RPI, and LAL had no specific absorption site in the small intestine of rats, and was not available for intestinal absorption.


Assuntos
Álcalis/química , Lisinoalanina/metabolismo , Oryza/química , Proteínas de Vegetais Comestíveis/metabolismo , Aminoácidos/metabolismo , Animais , Digestão , Masculino , Ratos , Ratos Sprague-Dawley
5.
J Org Chem ; 82(18): 9321-9327, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28829616

RESUMO

The sources of asymmetric induction in the photoinduced phase-transfer-catalytic perfluoroalkylation of ß-ketoesters were interpreted by density functional theory calculations. The calculations indicated that multiple hydrogen-bonding interactions mode rather than π-π stacking interactions model better described the transition structure of the reaction. The quantitative estimation of these noncovalent interactions within the key transition states identified that the O-H···O and specific C-H···O hydrogen bonds play key roles for the stereocontrol.

6.
J Diabetes Complications ; 31(1): 213-217, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27662781

RESUMO

AIMS: This study aimed to evaluate the association between total bilirubin (TBiL) and major diabetic complications among Chinese senile diabetic patients. METHODS: A cross-sectional study was conducted in all the cadre sanitariums in Beijing, between May 2012 and December 2014. All the diagnoses of diabetic complications were extracted from the medical records including chronic kidney disease, retinopathy, peripheral vascular disease, coronary heart disease, and ischemic stroke. RESULTS: The mean age of the 1839 senile diabetic patients were 87.4±4.0 (80-102years) and mean TBiL level was 13.2±6.0µmol/L. The prevalence of chronic kidney disease, retinopathy, peripheral vascular disease, coronary heart disease and ischemic stroke was 13.8%, 17.8%, 5.8%, 62.5%, and 44.5%, respectively. TBiL level was negatively correlated with age, weight, SBP, TC, FBG, 2hPG, diabetic duration and positively correlated with HDL-C. Prevalence of all five diseases gradually decreased with the increase of TBiL level (p<0.05). Also, number of diabetic complications showed a decreasing trend along with TBiL tertiaries. After adjusted age, education, marital status, current smoking, current drinking, physical activity ≥0.5h/day, BMI, hypertension, dyslipidemia, treatment and control status of diabetes, patients with higher TBiL level were at significantly decreased ORs for prevalence of major diabetic complications. The ORs were 0.97 (95%CI: 0.96-0.99), 0.90 (95%CI: 0.87-0.93), 0.98 (95%CI: 0.97-0.99), 0.97 (95%CI: 0.95-.99) and 0.98 (95%CI: 0.97-0.99) for chronic kidney disease, retinopathy, peripheral vascular disease, coronary heart disease and ischemic stroke (p<0.005). Similar results were obtained when TBiL was used as tertiary variable. CONCLUSION: Higher TBiL was significantly associated with lower prevalence of major diabetic complication among senile diabetic patients, and this association was graded with TBiL level and independent of age and control status of diabetes.


Assuntos
Envelhecimento , Bilirrubina/sangue , Demência/complicações , Complicações do Diabetes/complicações , Nefropatias Diabéticas/complicações , Hiperbilirrubinemia/etiologia , Insuficiência Renal Crônica/complicações , Idoso de 80 Anos ou mais , Pequim/epidemiologia , Isquemia Encefálica/complicações , Isquemia Encefálica/epidemiologia , Doença das Coronárias/complicações , Doença das Coronárias/epidemiologia , Estudos Transversais , Angiopatias Diabéticas/complicações , Angiopatias Diabéticas/epidemiologia , Cardiomiopatias Diabéticas/complicações , Cardiomiopatias Diabéticas/epidemiologia , Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/epidemiologia , Nefropatias Diabéticas/fisiopatologia , Retinopatia Diabética/complicações , Retinopatia Diabética/epidemiologia , Hospitais Especializados , Hospitais Urbanos , Humanos , Masculino , Prevalência , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/fisiopatologia , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/epidemiologia
7.
J Org Chem ; 81(24): 12357-12363, 2016 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-27978744

RESUMO

A metal-free, visible-light-induced photocatalytic procedure for decarboxylative alkynylation of carboxylic acids was reported. With 9,10-dicyanoanthracene as the photoredox catalyst, the reaction covered a broad scope of α-amino acids, α-oxo acids, and α-keto acids with blue LED irradiation at room temperature under an atmosphere of argon, delivering alkynyl products in moderate to excellent yields. Natural sun light also promoted this alkynylation strategy. This work represents the first example of an organophotocatalytic method for decarboxylative alkynylation of carboxylic acids.

8.
Org Lett ; 18(5): 1036-9, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26911719

RESUMO

An efficient amination reaction of 3-substituted benzofuran-2(3H)-ones promoted by cesium carbonate was developed. A putative mechanism involving a single-electron-transfer event was proposed, which represents a new reactivity for benzofuran-2(3H)-ones.

9.
Sensors (Basel) ; 15(12): 29893-909, 2015 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-26633400

RESUMO

With the increased availability of regional reference networks, Precise Point Positioning (PPP) can achieve fast ambiguity resolution (AR) and precise positioning by assimilating the satellite fractional cycle biases (FCBs) and atmospheric corrections derived from these networks. In such processing, the atmospheric corrections are usually treated as deterministic quantities. This is however unrealistic since the estimated atmospheric corrections obtained from the network data are random and furthermore the interpolated corrections diverge from the realistic corrections. This paper is dedicated to the stochastic modelling of atmospheric corrections and analyzing their effects on the PPP AR efficiency. The random errors of the interpolated corrections are processed as two components: one is from the random errors of estimated corrections at reference stations, while the other arises from the atmospheric delay discrepancies between reference stations and users. The interpolated atmospheric corrections are then applied by users as pseudo-observations with the estimated stochastic model. Two data sets are processed to assess the performance of interpolated corrections with the estimated stochastic models. The results show that when the stochastic characteristics of interpolated corrections are properly taken into account, the successful fix rate reaches 93.3% within 5 min for a medium inter-station distance network and 80.6% within 10 min for a long inter-station distance network.

10.
Sci Rep ; 5: 18391, 2015 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-26681470

RESUMO

A novel and convenient copper (II) bromide and 1,8-diazabicyclo[5.4.1]undec-7-ene (DBU) or 1,10-phenanthroline catalysis protocol for the construction of α-alkyl-ß-keto sulfones via C(sp(3))-H bond functionalization followed by C(sp(3))-S bond formation between aryl ketones and sodium sulfinates at room temperature has been developed. This method is applicable to a wide range of aryl ketones and sodium sulfinates. The electronic effects of aryl ketones and ligands effects of the copper salts are crucial for this transformation. Typically, substituted aryl ketones with electron-withdrawing group do not need any ligand to give a good to excellent yield, while substituted aryl ketones with electron-donating group and electron-rich heteroaromatic ketones offer a good to excellent yield only under the nitrogen-based ligands. The practical value of this transformation highlights the efficient and robust one-pot synthesis of α-alkyl-ß-keto sulfones.

11.
Sci Rep ; 5: 15250, 2015 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-26470633

RESUMO

Alcohols and alkenes are the most abundant and commonly used organic building blocks in the large-scale chemical synthesis. Herein, this is the first time to report a novel and operationally simple coupling reaction of vinylarenes and aliphatic alcohols catalyzed by manganese in the presence of TBHP (tert-butyl hydroperoxide). This coupling reaction provides the oxyalkylated products of vinylarenes with good regioselectivity and accomplishes with the principles of step-economies. A possible reaction mechanism has also been proposed.

12.
Molecules ; 20(9): 17208-20, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26393558

RESUMO

An efficient multi-component reaction to synthesize multi-substituted 1,3-oxazolidine compounds of high optical purity was described. All the products were well-characterized and the absolute configuration of one chiral center was determined. The plausible mechanism was proposed and a kinetic resolution of epoxides process was confirmed.


Assuntos
Oxazóis/síntese química , Cinética , Estrutura Molecular , Oxazóis/química , Estereoisomerismo
13.
Org Lett ; 17(18): 4460-3, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26348870

RESUMO

A novel copper/manganese cocatalyzed direct oxidative coupling of terminal vinylarenes with ketones via C(sp(3))-H bond functionalization following C-C bond formation has been developed using tert-butyl hydroperoxide as the radical initiator. Various ketones underwent a free-radical addition of terminal vinylarenes to give the corresponding 1,4-dicarbonyl products with excellent regioselectivity and efficiency through one step. A possible reaction mechanism has been proposed.

14.
ACS Appl Mater Interfaces ; 6(24): 22673-9, 2014 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-25470597

RESUMO

Centimeters-long SiC nanowire could be a strong "bridge" between microworld and macroworld due to its unique morphology, excellent chemical stability, and intriguing physical properties. Here we present a novel "paperlike" material-free-standing SiC nanopaper fabricated by acetone-assisted compression of centimeters-long SiC nanowires. The resistance of this new paperlike material linearly increases with increasing environmental relative humidity in a very short time. We suggest that adsorption of water molecules on SiC nanopaper surface led to fast electron transfer between SiC nanopaper and water layer, which indicates that SiC nanopaper could be applied to high-performance humidity sensor in harsh environment.

15.
Sci Rep ; 4: 7446, 2014 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-25502282

RESUMO

A nickel- and manganese-catalyzed decarboxylative cross coupling of α, ß-unsaturated carboxylic acids with cyclic ethers such as tetrahydrofuran and 1, 4-dioxane was developed. Oxyalkylation was achieved when nickel acetate was used as catalyst, while manganese acetate promoted the reaction of alkenylation.

16.
Lab Chip ; 11(16): 2779-84, 2011 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-21713287

RESUMO

Highly effective mixing in microchannels is important for most chemical reactions conducted in microfluidic chips. To obtain a rigid and chemically resistant micromixer system at low cost, we fabricated a Y-shaped microchannel with built-in mixer structures by static liquid photolithography (SLP) from methacrylated polyvinylsilazane (MPVSZ) as an inorganic polymer photoresist which was then converted to a silicate phase by hydrolysis in vaporized ammonia atmosphere at 80 °C. The microchannel incorporating herringbone mixer structures was bonded with a matching polydimethylsiloxane (PDMS) open channel which was pre-coated by perhydropolysilazane (PHPS)-based mixture, and finally treated by additional hydrolysis at room temperature to convert the PHPS layer to a silica phase. Finally, the chemical resistance of the microfluidic system with embedded micromixer was confirmed with various solvents, and the excellent mixing performance in a short mixing length of 2.3 cm was demonstrated by injecting two different colored fluids into the microchannel.


Assuntos
Dimetilpolisiloxanos/química , Técnicas Analíticas Microfluídicas/instrumentação , Polímeros/química , Dimetilpolisiloxanos/síntese química , Polímeros/síntese química , Dióxido de Silício/química
17.
Circulation ; 114(21): 2217-25, 2006 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-17088464

RESUMO

BACKGROUND: Stroke is much more prevalent than coronary heart disease in China; thus, any risk prediction model only for coronary heart disease may not be appropriate in application. Our objective is to develop a cardiovascular risk prediction model appropriate for the Chinese population. METHODS AND RESULTS: Cox proportional hazards regression was used to develop sex-specific optimal 10-year risk prediction models for ischemic cardiovascular disease (ICVD; including ischemic stroke and coronary events) from 17 years of follow-up data from the USA-PRC Collaborative Study of Cardiovascular Epidemiology cohort, in which 9903 participants were followed up every 2 years until 2000, and 371 ICVD events (266 strokes and 105 coronary heart disease events) occurred. The models showed ICVD was positively related to age, systolic blood pressure, serum total cholesterol, body mass index, current smoking status, and diabetes mellitus in both men and women. When the models were applied to the 17,329 participants in the China Multicenter Collaborative Study of Cardiovascular Epidemiology cohort, the areas under the receiver operating characteristic curve were 0.796+/-0.036 for men and 0.791+/-0.036 for women. The simplified point score model resulted in similar c statistics. Comparison of the observed with the estimated incidence of ICVD at different risk levels showed satisfactory precision. Meanwhile, application of recalibrated Framingham models significantly overestimated the coronary heart disease risk in both men (by approximately 97%) and women (by approximately 228%). CONCLUSIONS: The Cox regression prediction models and simplified point score model have satisfying predictive capability for estimating the 10-year integrated cardiovascular risk in Chinese, in whom stroke is the predominant cardiovascular disease.


Assuntos
Grupo com Ancestrais do Continente Asiático , Isquemia Encefálica/complicações , Doença das Coronárias/etiologia , Doença das Coronárias/mortalidade , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade , Adulto , Grupo com Ancestrais do Continente Asiático/estatística & dados numéricos , Estudos de Coortes , Doença das Coronárias/epidemiologia , Doença das Coronárias/etnologia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Prognóstico , Modelos de Riscos Proporcionais , Reprodutibilidade dos Testes , Medição de Risco , Distribuição por Sexo , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etnologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-16134368

RESUMO

Removal of organic compounds, inorganic nutrients, and bacteria from aquaculture wastewaters before discharge cannot only minimize deterioration of receiving water quality, but can also make possible the reuse of the original water in the culture of prawn, fish, and shellfish. In this study, the feasibility of using chitosan, a multifunctional environmentally friendly biopolymer, at different molecular weights to simultaneously remove various pollutants from the discharge of an eel culture pond is evaluated. Experimental results indicated chitosan with a high molecular weight was best at removing turbidity, suspended solids, and biological and chemical oxygen demand (BOD and COD). In contrast, chitosan of a low molecular weight excelled at removing NH3 and PO4(3-) from wastewater. Additionally, chitosan with a high molecular weight did well at eliminating suspended solids of various particle sizes relative to chitosan with a low molecular weight. The best performance of chitosan in removing turbidity, suspended solids, BOD, COD, NH3, PO4(3-), and bacteria was 87.7%, 62.6%, 52.3%, 62.8%, 91.8%, 99.1%, and 99.998% removal, respectively. When chitosan with a high molecular weight was added at 12 mg/L, the quality of treated wastewater successfully complied with government discharge standards. Furthermore, the relatively low bacteria amount in the wastewater after treatment with chitosan was confirmed by both the plate count method and molecular analysis technique. These results indicated that the application of chitosan is feasible in an effort to recycle the effluents of a culture pond.


Assuntos
Aquicultura/normas , Quitosana/química , Poluentes da Água/análise , Purificação da Água/métodos , Aquicultura/métodos , Peso Molecular , Taiwan
19.
Ann Epidemiol ; 14(6): 399-408, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15246328

RESUMO

PURPOSE: To examine the relationships of total and cause-specific mortality to serum cholesterol in four diverse populations. METHODS: Chinese, Polish, Russian, and US population-based samples were studied. The relationship between cholesterol levels and mortality was assessed by Cox proportional hazard regression with restricted piecewise cubic splines. RESULTS: The cholesterol and total mortality relationship was statistically significantly J-shaped for all men combined. In country-specific relationships, cholesterol was significantly, linearly, and positively related to total mortality in Russian and US men. For women, the relationship was non-linear, but not statistically significant, and became statistically significant upon adjustment for other risk factors. For Polish women, a statistically significant inverse relationship existed. CHD mortality and cardiovascular disease (CVD) mortality increased linearly with cholesterol in Polish, Russian, and US men and the aggregate of men, but there was no relationship for women. Cancer mortality was not related to cholesterol except for the Polish cohort and Russian women, where there was an inverse relationship. CONCLUSIONS: Serum cholesterol was a strong, consistent predictor of CHD and CVD mortality in Polish, Russian, and US men despite their social diversity. In contrast to CHD mortality, the relation of cholesterol to total mortality and non-CVD mortality varied by country and gender.


Assuntos
Colesterol/sangue , Mortalidade/tendências , Adulto , Teorema de Bayes , Biomarcadores/sangue , Doenças Cardiovasculares/mortalidade , Causas de Morte , China/epidemiologia , Colesterol/classificação , Doença das Coronárias/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polônia/epidemiologia , Modelos de Riscos Proporcionais , Medição de Risco , Fatores de Risco , Federação Russa/epidemiologia , Estados Unidos/epidemiologia
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