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1.
Int J Ophthalmol ; 16(12): 2105-2116, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38111927

RESUMO

AIM: To evaluate the efficacy of intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF), photodynamic therapy (PDT), and laser treatment (LT) for anatomical and functional improvement in myopic choroidal neovascularization (mCNV) patients. METHODS: Two researchers independently searched PubMed, Cochrane Library, Web of Science, and other databases to screen studies comparing best-corrected vision acuity (BCVA) and foveal center thickness (FCT) changes after mCNV treatment. Post-treatment chorioretinal atrophy (CRA) is a secondary outcome indicator. The retrieval time limit is from the database construction to January 30, 2023. RESULTS: A total of 1072 eyes in 16 articles were included. In the RCTs, intravitreal bevacizumab (IVB) and intravitreal ranibizumab (IVR) were superior to PDT (MD=0.18, 95%CI: 0.02, 0.40, MD=0.18, 95%CI: 0.01, 0.42) in improving BCVA of mCNV patients (P<0.05). The relative effectiveness in improving BCVA, from high to low, appeared to be IVR, intravitreal aflibercept (IVA), IVB, LT, PDT, and sham first followed by IVA (Sham/IVA). While improving the FCT from high to low was IVA, IVR, IVB, PDT. In retrospective studies, the results of BCVA after long-term treatment showed that all the therapeutic effects from high to low was IVA, intravitreal conbercept (IVC), IVR, IVB, IVB/IVR, PDT with IVB/IVR, PDT. The effect of improving FCT was IVA, IVR, IVC, PDT, and IVB from high to low. And in the effects of improving CRA, the IVB appeared to be higher than IVR, while the PDT was the smallest, but none of the differences in the results were statistically significant. CONCLUSION: Anti-VEGF has the best effect on long-term vision improvement in mCNV patients, using IVB or IVR alone to treat mCNV may be better than IVB or IVR combined with PDT. There is no significant difference in the improvement of visual acuity, macular edema, and CRA in mCNV patients treated with any different anti-VEGF drugs.

2.
Front Nutr ; 10: 1259453, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37743920

RESUMO

Background: Despite growing evidence for the association of adherence to the Mediterranean diet with gastric cancer risk, the results remain inconclusive. The purpose of this systematic review and meta-analysis was to summarize the evidence from previous observational studies and assess the potential association between adherence to the Mediterranean diet and risk of gastric cancer using a dose-response meta-analysis. Methods: A comprehensive literature search for all observational studies published up to June 30, 2023 was conducted using the databases of PubMed, ISI Web of Science, EBSCO, China National Knowledge Infrastructure (CNKI) and Wanfang Data. The pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated for the highest versus the lowest categories of Mediterranean diet score in relation to gastric cancer risk, using random-effects models. The Cochran's Q test and I-squared (I2) statistic were used to detect the sources of heterogeneity among the included studies. Results: Overall, 11 studies (five cohort and six case-control studies) with a total number of 1,366,318 participants were included in the final analysis. Combining 14 effect sizes from 11 studies revealed that compared with the lowest category, the highest adherence to the Mediterranean diet was associated with a 29% reduction in the risk of gastric cancer (RR:0.71; 95%CI:0.59-0.84, p < 0.001). In addition, linear dose-response analysis showed that each 1-score increment in Mediterranean diet score was associated with a 5% lower risk of gastric cancer (RR:0.95; 95%CI: 0.94-0.96, p < 0.001). Stratified analysis showed a significant association between adherence to the Mediterranean diet and risk of gastric cancer in case-control studies (RR = 0.44;95%CI:0.32-0.61, p < 0.001), and a marginally significant association in prospective cohort studies (RR = 0.88; 95%CI: 0.79-0.98, p = 0.024), respectively. At the same time, a more significant association between Mediterranean diet and reduced risk of gastric cancer was observed in other countries (RR = 0.28; 95%CI:0.16-0.49, p < 0.001) than in Western countries (RR = 0.75; 95%CI:0.64-0.88, p = 0.001). Conclusion: Our results demonstrate that high adherence to the Mediterranean diet is associated with 29% reduced risk of gastric cancer. Further large prospective studies and randomized controlled trials are warranted to confirm our findings.

3.
PLoS One ; 18(8): e0290259, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37616305

RESUMO

Obesity-related diseases have been on the rise, making it important to promote physical activity. Smart sports watches are popular among young people and can play a role in this regard. This study aims to evaluate the impact of different watch head design types on the visual image of smart sports watches. Based on sales data, seven sports smartwatches with sales of over 2000 units were selected from a sample of 50 as representative samples. A factor analysis and questionnaire survey were used to identify four groups of adjectives that describe watch heads: Sporty and Smart, precious and exquisite, distinctive and avant-garde, and trendy and technological. College students evaluated the seven watches using these adjectives, and using triangular fuzzy mathematics theory, the watches were divided into three categories. The results show that the seven watches had significant differences in appearing "Sporty and Smart" and "precious and exquisite", while the visual imagery of "distinctive and avant-garde" and "trendy and technological" had no significant difference. Based on the grouping analysis of the seven samples, it is concluded that: the slim and compact shape without excessive decoration has a sense of sportiness and simplicity; the square shape combined with left and right buttons has a sense of sportiness and fashion; the unique connection between the round shape, the watch strap, and the watch head, as well as the strong mechanical feeling, have a sense of value. To substantiate the validity of our research findings, we devised three novel specimens based on the morphological elements of sports watches and conducted surveys accordingly. Statistical analysis revealed a fundamental coherence between the performance of these specimens in four stylistic domains and the expression of style-forming elements, confirming the reference value of these findings in the stylistic design of sports smartwatches. This study provides designers with references for improving the design and development efficiency of smart sports watches, promoting their sustainable development.


Assuntos
Esportes , Percepção Visual , Humanos , Adolescente , Comércio , Emoções , Exercício Físico
4.
Phys Chem Chem Phys ; 25(20): 14232-14244, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37170792

RESUMO

Pt/CeO2 catalysts exhibit excellent catalytic performance for the methanol dehydrogenation (MD) reaction. In this work, MD reactions on three systems of Pt1/CeO2(110)), Pt7/CeO2(110), and Pt1/Ce1-xO2(110) are investigated via density functional theory (DFT) calculations. The CH3OH adsorption, electronic structure of the catalyst, and mechanism of methanol decomposition (MD) are systematically calculated. The results reveal that the d-band center of the Pt atom moves away from the Fermi level in the order of Pt1/CeO2(110) < Pt7/CeO2(110) < Pt1/Ce1-xO2(110), and the order of the activity of the MD reaction is Pt1/CeO2(110) < Pt7/CeO2(110) < Pt1/Ce1-xO2(110). The results of the microkinetic dynamics simulation verify that only Pt1/Ce1-xO2(110) is conducive to the decomposition of methanol at low temperatures (373 K), and the products CO and H2 are easily dissociated from the catalyst surface. This work uncovers that both the small size and the Ce vacancy substituted sites of Pt favor the performance of the Pt/CeO2 catalyst, and provides theoretical guidance for the construction and design of efficient metal-support catalysts for the MD reaction.

5.
Phys Chem Chem Phys ; 23(48): 27340-27347, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34854437

RESUMO

Density functional theory (DFT) calculations are carried out to investigate the effect of point defects on acetylene hydrogenation reaction over Ni(111) surface with three different defect concentrations (DC = 0.0500, 0.0625, and 0.0833), compared with the perfect Ni(111) surface. The adsorptions of C2 species and H atoms and the mechanism of acetylene hydrogenation via the ethylene pathway are systematically analyzed. The results indicate that the existence of defects will make C2 species and H atoms more inclined to adsorb near the defects. Introducing an appropriate amount of point defect concentration can enhance the catalytic activity and ethylene selectivity of Ni. In this work, DC = 0.0625 Ni(111) surface has the highest catalytic activity and selectivity of ethylene. This work provides useful theoretical information on the effect of defects on acetylene hydrogenation and is helpful for the design of Ni and related metal catalysts with defects.

6.
Analyst ; 146(6): 2074-2082, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33566037

RESUMO

Inductively coupled plasma-mass spectrometry (ICP-MS) is one of the most powerful techniques for multiplex nucleotide assay owing to the virtue of the high resolution of multiple-elements' mass to charge ratio, in a mass spectrum. Here, a small sized (less than 20 nm) noble-metal nanoparticle labelled ICP-MS (NP-ICP-MS) is proposed for high-throughput microRNA (miRNA) determination. Three miRNA targets - miR-486-5p, miR-221, and miR-21 - in serum, were distinguished by single-stranded DNA (ssDNA) probes labelled with a small sized noble-metal nanoparticle - silver nanoparticles (AgNPs), platinum nanoparticles (PtNPs), and gold nanoparticles (AuNPs). The counting isotopes ion intensity per second (CPS) of the noble-metal label versus internal standard isotope intensity of 115In and 209Bi, exhibited good linearity in the range 0.25 pM to 100 pM with correlation coefficients (R2) of 0.9680, 0.9305, and 0.9418. The specific sandwich-type miRNA assay using the sensitive NP-ICP-MS readout pushed the detection limits down to 0.18 pM for miR-221, 0.23 pM for miR-486-5p, and 0.22 pM for miR-21. And the relative standard deviations (RSDs) for 10 pM target miRNA were less than 3.7%. This work promises a potential ultrasensitive ICP-MS bioassay of multiplex miRNA biomarkers for clinical serum diagnosis.


Assuntos
Nanopartículas Metálicas , MicroRNAs , Ouro , Isótopos , MicroRNAs/genética , Platina , Prata
7.
Phys Chem Chem Phys ; 22(35): 19758-19768, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32844826

RESUMO

The ion exchange reaction has been extensively used in the field of synthesis of functionalized supramolecular materials such as layered double hydroxides (LDHs), ion-embedded batteries, sewage disposal and so on. In this work, the factors influencing the anion exchange behavior in the LDH gallery, such as the exchange domain, the exchange order, the driving force, and the diffusion of the anions, are investigated systematically using molecular dynamics (MD) simulations and density functional theory (DFT) methods in view of both thermodynamics and dynamics. 159 models of MIIRAl-A-LDHs (MII = Mg, Ni, Zn; R = 1.4-8, A = OH-, Cl-, Br-, NO3-, HCOO-, C6H5SO3-, CO32-, SO42-, and PO43-, respectively) are calculated. The results reveal that the anion exchange domain (interlayer distance) in LDHs is determined not only by the size and their arrangement modes of the guest anions, but also by the charges the anions carry. The relative binding energies of different anions and the Gibbs free energy changes of the anion exchange reactions in LDHs decrease in the order of PO43- > CO32- > SO42- > OH- > Cl- > Br- > HCOO- > NO3- > C6H5SO3-, which is in accordance with the experimental anion exchange order. The stronger the hydrogen bonding between the anion and the host, the larger the charge transfer, and the smaller the electronegativity of the anion, the more difficult it is for the anion to be exchanged out from LDH interlayer. In addition, for the anions with the same charges, the relative binding energy is linearly well correlated with the interlayer spacing. By analyzing the contribution of each energetic item comprising the total potential energy, it is found that the major driving force of anion exchange is the electrostatic force. The diffusion coefficient (D) along the c direction is nearly equal to zero, suggesting that the diffusion of anions occurs mainly in the ab plane of the LDH cell. It also can be inferred that when the cell parameter c < 24.0 Å, the anion exchange order is mainly determined by the thermodynamic factors, whereas when c > 24.0 Å, both the thermodynamic and the dynamic factors cast the same effect on the anion exchange behavior. This work provides an in-depth understanding of the anion exchange behavior, and is helpful guidance for the design and synthesis of functionalized guest anion intercalated LDHs and related materials using the anion-exchange method.

8.
Medicine (Baltimore) ; 98(2): e14113, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30633225

RESUMO

Limited studies have reported the association between dietary patterns and the risk of Helicobacter pylori (H pylori) infection. The purpose of this study was to evaluate the relationship between dietary patterns and H pylori infection in a Chinese population ages from 45 to 59 years. We performed a cross-sectional examination of the associations between dietary patterns and H pylori infection in 3014 Chinese adults ages between 45 and 59 years from Hangzhou city, Zhejiang province, China. Dietary intake was assessed through a semi-quantitative food frequency questionnaire (FFQ). H pylori infection was diagnosed using the C-urea breath test. Multivariable logistic regression analyses were used to determine the associations between dietary patterns and the risk of H pylori infection. The prevalence of H pylori infection was 27.5%. Four major dietary patterns were identified by means of factor analysis: health-conscious, Western, grains-vegetables and high-salt patterns. After adjustment for the potential confounders, participants in the highest quartile of the "grains-vegetables" pattern scores had a lower odds ratio (OR) for H pylori infection (OR = 0.82; 95% confidence interval [CI]: 0.732-0.973; P = .04) than did those in the lowest quartile. Compared with those in the lowest quartile, participants in the highest quartile of the "high-salt" pattern scores had a greater OR for H pylori infection (OR = 1.13; 95%CI: 1.004-1.139; P = .048). Besides, no significant associations were found between the "health-conscious" and "Western" dietary patterns and the risk of H pylori infection.Our findings demonstrate that the "grains-vegetables" pattern is associated with a decreased risk, while "high-salt" pattern is associated with an increased risk of H pylori infection.


Assuntos
Dieta/efeitos adversos , Infecções por Helicobacter/etiologia , Helicobacter pylori , China/epidemiologia , Estudos Transversais , Inquéritos sobre Dietas , Feminino , Infecções por Helicobacter/epidemiologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
9.
Med Sci Monit ; 25: 184-192, 2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30615603

RESUMO

BACKGROUND Ulcerative colitis (UC) and Crohn's disease (CD) are the 2 main type of inflammatory bowel diseases (IBDs). Several studies have been conducted to investigate the association of fucosyltransferase 2 gene (rs601338) variant with UC and CD, but the results were inconsistent. Here, we performed a meta-analysis to clarify this issue based on a relatively larger sample size. MATERIAL AND METHODS A systematic literature search was conducted in PubMed, Embase, CNKI, and Chinese Wangfang databases up to 31 May 2018. Meta results were synthesized by using crude odds ratio with 95% confidence interval. Heterogeneity, sensitivity analysis, subgroup analysis, and publication bias were assessed using STATA 11.0 software. RESULTS A total of 8 relevant studies including 3874 IBDs patients (1872 UC cases, 2002 CD cases) and 5445 controls were included for meta-analysis. We found a significant association between rs601338 A allele and risk of IBDs in the Chinese population (OR=2.35, 95%CI=1.66~3.34, P=0.001), but not in whites. Stratified by disease type, we found a significant association between rs601338 polymorphism with CD and UC in the Chinese population, but not in the white population. In addition, funnel plot and Egger's linear regression test suggests no publication bias in all genetic models. CONCLUSIONS Fucosyltransferase 2 gene (rs601338) polymorphism is associated with susceptibility to IBD, UC, and CD in the Chinese population, but these results might not be generalizable to other ethnic populations. Further well-designed studies are needed to confirm these findings.


Assuntos
Fucosiltransferases/genética , Doenças Inflamatórias Intestinais/genética , Adulto , Idoso , Alelos , Povo Asiático/genética , Colite Ulcerativa/genética , Doença de Crohn/genética , Feminino , Fucosiltransferases/metabolismo , Frequência do Gene/genética , Estudos de Associação Genética , Predisposição Genética para Doença/genética , Variação Genética/genética , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , População Branca/genética , Galactosídeo 2-alfa-L-Fucosiltransferase
10.
Stem Cell Reports ; 8(2): 290-304, 2017 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-28111280

RESUMO

Maternal nicotine exposure causes alteration of gene expression and cardiovascular programming. The discovery of nicotine-medicated regulation in cardiogenesis is of major importance for the study of cardiac defects. The present study investigated the effect of nicotine on cardiac gene expression and epigenetic regulation during myocardial differentiation. Persistent nicotine exposure selectively inhibited expression of two cardiac genes, Tbx5 and Gata4, by promoter DNA hypermethylation. The nicotine-induced suppression on cardiac differentiation was restored by general nicotinic acetylcholine receptor inhibition. Consistent results of Tbx5 and Gata4 gene suppression and cardiac function impairment with decreased left ventricular ejection fraction were obtained from in vivo studies in offspring. Our results present a direct repressive effect of nicotine on myocardial differentiation by regulating cardiac gene suppression via promoter DNA hypermethylation, contributing to the etiology of smoking-associated cardiac defects.


Assuntos
Diferenciação Celular/genética , Metilação de DNA/efeitos dos fármacos , Fator de Transcrição GATA4/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Células Musculares/citologia , Células Musculares/metabolismo , Nicotina/farmacologia , Proteínas com Domínio T/genética , Animais , Sequência de Bases , Linhagem Celular , Sobrevivência Celular/genética , DNA (Citosina-5-)-Metiltransferase 1/genética , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Corpos Embrioides , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Feminino , Masculino , Camundongos , Antagonistas Nicotínicos/farmacologia , Gravidez , Regiões Promotoras Genéticas , Ratos , Receptores Nicotínicos/metabolismo
11.
Eur J Cancer Prev ; 26(3): 201-211, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-26945285

RESUMO

The analysis of dietary patterns has recently drawn considerable attention as a method of investigating the association between the overall whole diet and the risk of colorectal cancer. However, the results have yielded conflicting findings. Here, we carried out a meta-analysis to identify the association between dietary patterns and the risk of colorectal cancer. A total of 40 studies fulfilled the inclusion criteria and were included in this meta-analysis. The highest category of 'healthy' dietary pattern compared with the lowest category was apparently associated with a decreased risk for colorectal cancer [odds ratio (OR)=0.75; confidence interval (CI): 0.68-0.83; P<0.00001]. An increased risk of colorectal cancer was shown for the highest compared with the lowest category of a 'western-style' dietary pattern (OR=1.40; CI: 1.26-1.56; P<0.00001). There was an increased risk of colorectal cancer in the highest compared with the lowest category of 'alcohol-consumption' pattern (OR=1.44; CI: 1.13-1.82; P=0.003). The results of this meta-analysis indicate that a 'healthy' dietary pattern may decrease the risk of colorectal cancer, whereas 'western-style' and 'alcohol-consumption' patterns may increase the risk of colorectal cancer.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/prevenção & controle , Dieta Saudável/tendências , Dieta Ocidental/efeitos adversos , Consumo de Bebidas Alcoólicas/epidemiologia , Neoplasias Colorretais/diagnóstico , Dieta/efeitos adversos , Comportamento Alimentar/fisiologia , Humanos , Fatores de Risco
12.
Sci Rep ; 6: 19392, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26765840

RESUMO

Most enzymes that act on carbohydrates include non-catalytic carbohydrate-binding modules (CBMs) that recognize and target carbohydrates. CBMs bring their appended catalytic modules into close proximity with the target substrate and increase the hydrolytic rate of enzymes acting on insoluble substrates. We previously identified a novel CBM (CBMC5614-1) at the C-terminus of endoglucanase C5614-1 from an uncultured microorganism present in buffalo rumen. In the present study, that the functional region of CBMC5614-1 involved in ligand binding was localized to 134 amino acids. Two representative homologs of CBMC5614-1, sharing the same ligand binding profile, targeted a range of ß-linked polysaccharides that adopt very different conformations. Targeted substrates included soluble and insoluble cellulose, ß-1,3/1,4-mixed linked glucans, xylan, and mannan. Mutagenesis revealed that three conserved aromatic residues (Trp-380, Tyr-411, and Trp-423) play an important role in ligand recognition and targeting. These results suggest that CBMC5614-1 and its homologs form a novel CBM family (CBM72) with a broad ligand-binding specificity. CBM72 members can provide new insight into CBM-ligand interactions and may have potential in protein engineering and biocatalysis.


Assuntos
Metabolismo dos Carboidratos , Carboidratos/química , Enzimas/química , Enzimas/metabolismo , Domínios e Motivos de Interação entre Proteínas , Sequência de Aminoácidos , Sítios de Ligação , Sequência Conservada , Enzimas/genética , Isoenzimas , Ligantes , Família Multigênica , Polissacarídeos/química , Polissacarídeos/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Solubilidade , Especificidade por Substrato
13.
Sheng Li Ke Xue Jin Zhan ; 46(2): 87-93, 2015 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-26201104

RESUMO

In the context of a growing pandemic of myocardial infarction (MI), the current standard therapies cannot provide an ideal outcome for the patients. Hence, novel approaches are being explored to identify curative treatment. In recent years, stem cell has been regarded as a critical source for cardiac regeneration, and several types of stem cells have been demonstrated with cardiogenic capacity. To date, thousands of patients with MI have received autologous stem cells therapy, but the benefits were modest. In this review, we summarize the recent findings of stem cells therapy in cardiac repair and regeneration, and propose the key unsolved hurdles in this field.


Assuntos
Coração , Transplante de Células-Tronco , Humanos , Infarto do Miocárdio , Regeneração
14.
J Cell Mol Med ; 19(8): 1825-35, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25824297

RESUMO

The chemokine (C-X-C motif) receptor 4 (CXCR4) is expressed on native cardiomyocytes and can modulate isolated cardiomyocyte contractility. This study examines the role of CXCR4 in cardiomyocyte response to ischaemia-reperfusion (I/R) injury. Isolated adult rat ventricular cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) to simulate I/R injury. In response to H/R injury, the decrease in CXCR4 expression was associated with dysfunctional energy metabolism indicated by an increased adenosine diphosphate/adenosine triphosphate (ADP/ATP) ratio. CXCR4-overexpressing cardiomyocytes were used to determine whether such overexpression (OE) can prevent bio-energetic disruption-associated cell death. CXCR4 OE was performed with adenoviral infection with CXCR4 encoding-gene or non-translated nucleotide sequence (Control). The increased CXCR4 expression was observed in cardiomyocytes post CXCR4-adenovirus transduction and this OE significantly reduced the cardiomyocyte contractility under basal conditions. Although the same extent of H/R-provoked cytosolic calcium overload was measured, the hydrogen peroxide-induced decay of mitochondrial membrane potential was suppressed in CXCR4 OE group compared with control group, and the mitochondrial swelling was significantly attenuated in CXCR4 group, implicating that CXCR4 OE prevents permeability transition pore opening exposure to overload calcium. Interestingly, this CXCR4-induced mitochondrial protective effect is associated with the enhanced signal transducer and activator of transcription 3 (expression in mitochondria. Consequently, in the presence of H/R, mitochondrial dysfunction was mitigated and cardiomyocyte death was decreased to 65% in the CXCR4 OE group as compared with the control group. I/R injury leads to the reduction in CXCR4 in cardiomyocytes associated with the dysfunctional energy metabolism, and CXCR4 OE can alleviate mitochondrial dysfunction to improve cardiomyocyte survival.


Assuntos
Mitocôndrias Cardíacas/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Receptores CXCR4/metabolismo , Adenoviridae/metabolismo , Animais , Cálcio/farmacologia , Cardiotônicos/farmacologia , Morte Celular/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Citosol/efeitos dos fármacos , Citosol/metabolismo , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/patologia , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Fator de Transcrição STAT3/metabolismo
15.
PLoS One ; 10(3): e0121531, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25811759

RESUMO

Alpha-amylase is a very important enzyme in the starch conversion process. Most of the α-amylases are calcium-dependent and exhibit poor performance in the simultaneous saccharification and fermentation process of industrial bioethanol production that uses starch as feedstock. In this study, an extracellular amylolytic enzyme was purified from the culture broth of newly isolated Talaromyces pinophilus strain 1-95. The purified amylolytic enzyme, with an apparent molecular weight of 58 kDa on SDS-PAGE, hydrolyzed maltopentaose, maltohexaose, and maltoheptaose into mainly maltose and maltotriose and minor amount of glucose, confirming the endo-acting mode of the enzyme, and hence, was named Talaromyces pinophilus α-amylase (TpAA). TpAA was most active at pH 4.0-5.0 (with the temperature held at 37°C) and 55°C (at pH 5.0), and stable within the pH range of 5.0-9.5 (at 4°C) and below 45°C (at pH 5.0). Interestingly, the Ca2+ did not improve its enzymatic activity, optimal temperature, or thermostability of the enzyme, indicating that the TpAA was Ca2+-independent. TpAA displayed higher enzyme activity toward malto-oligosaccharides and dextrin than other previously reported α-amylases. This highly active Ca2+-independent α-amylase may have potential applications in starch-to-ethanol conversion process.


Assuntos
Cálcio/farmacologia , Talaromyces/enzimologia , alfa-Amilases/isolamento & purificação , alfa-Amilases/metabolismo , Amilose/metabolismo , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Hidrólise , Íons , Cinética , Dados de Sequência Molecular , Peso Molecular , Solubilidade , Solventes/farmacologia , Especificidade por Substrato/efeitos dos fármacos , Talaromyces/citologia , Temperatura
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