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1.
Nanotechnology ; 35(12)2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38055979

RESUMO

Tin oxide-based (SnO2) materials show high theoretical capacity for lithium and sodium storage benefiting from a double-reaction mechanism of conversion and alloying reactions. However, due to the limitation of the reaction thermodynamics and kinetics, the conversion reaction process of SnO2usually shows irreversibility, resulting in serious capacity decay and hindering the further application of the SnO2anode. Herein, SnO2/SnS heterojunction was anchored on the surface and inside of CMK-3 byinsitusynthesis method, forming a stable 3D structural material (SnO2/SnS@CMK-3). The electrochemical properties of SnO2/SnS@CMK-3 composite show high capacity and reversible conversion reaction, which was attributed to the synergistic effect of CMK-3 and SnO2/SnS heterojunction. To further investigate the influence of the heterojunction on the reversibility of the conversion reaction, the Gibbs free energy (ΔG) was calculated using density functional theory. The results show that SnO2/SnS heterojunction has a closer to zero ΔGfor lithium/sodium ion batteries compared to SnO2, indicating that the heterojunction enhances the reversibility of the conversion reaction in chemical reaction thermodynamics. Our work provides insights into the reversibility of the conversion reaction of SnO2-based materials, which is essential for improving their electrochemical performance.

2.
Int J Biometeorol ; 65(11): 1871-1880, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33963898

RESUMO

Current development of temperature-related health early warning systems mainly arises from knowledge of temperature-related mortality or hospital-based morbidity. However, due to the delay in data reporting and limits in hospital capacity, these indicators cannot be used in health risk assessments timely. In this study, we examine temperature impacts on emergency ambulance and discuss the benefits of using this near real-time indicator for risk assessment and early warning. We collected ambulance dispatch data recording individual characteristics and preliminary diagnoses between 2015 and 2016 in Shenzhen, China. Distributed lag nonlinear model was used to examine the effects of high and low temperatures on ambulance dispatches during warm and cold seasons. Lag effects were also assessed to evaluate the sensitivity of ambulance dispatches in reflecting immediate health reactions. Stratified analyses by gender, age, and a wide range of diagnoses were performed to identify vulnerable subgroups. Disease-specific numbers of ambulance dispatches attributable to non-optimal temperature were calculated to determine the related medical burdens. Effects of temperature on ambulance dispatches appeared to be acute on the current day. Males, people aged 18-44 years, were more susceptible to non-optimal temperatures. Highest RR during heat exposure by far was for urinary disease, alcohol intoxication, and traumatic injury, while alcohol intoxication and cardiovascular disease were especially sensitive to cold exposure, causing the main part of health burden. The development of local health surveillance systems by utilizing ambulance dispatch data are important for temperature impact assessments and medical resource reallocation.


Assuntos
Ambulâncias , Temperatura Alta , Temperatura Baixa , Humanos , Masculino , Morbidade , Temperatura
3.
Neural Plast ; 2019: 5271573, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31007684

RESUMO

Motor capability recovery after ischemic stroke involves dynamic remodeling processes of neural connectomes in the nervous system. Various neuromodulatory strategies combining direct stimulating interventions with behavioral trainings for motor recovery after ischemic stroke have been developed. However, the effectiveness of these interventions varies widely due to unspecific activation or inhibition of undefined neuronal subtypes. Optogenetics is a functional and structural connection-based approach that can selectively activate or inhibit specific subtype neurons with a higher precision, and it has been widely applied to build up neuronal plasticities of the nervous system, which shows a great potential in restoring motor functions in stroke animal models. Here, we reviewed neurobiological mechanisms of enhanced brain plasticities underlying motor recovery through the optogenetic stimulation after ischemic stroke. Several brain sites and neural circuits that have been previously proven effective for motor function rehabilitation were identified, which would be helpful for a more schematic understanding of effective neuronal connectomes in the motor function recovery after ischemic stroke.


Assuntos
Isquemia Encefálica/fisiopatologia , Encéfalo/fisiopatologia , Plasticidade Neuronal , Optogenética , Reabilitação do Acidente Vascular Cerebral/métodos , Acidente Vascular Cerebral/fisiopatologia , Animais , Isquemia Encefálica/complicações , Humanos , Neurogênese , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/complicações
4.
Zhongguo Dang Dai Er Ke Za Zhi ; 21(1): 82-88, 2019 Jan.
Artigo em Zh | MEDLINE | ID: mdl-30675869

RESUMO

OBJECTIVE: To systematically review the effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children. METHODS: RevMan5.3 was used to perform a Meta analysis of randomized controlled trials on the effect of probiotic supplementation during pregnancy and infancy in preventing atopic dermatitis in children published between January 2008 and May 2018 across the world. A subgroup analysis was conducted according to the type of probiotics for intervention, follow-up time, time of probiotic supplementation, and study areas. RESULTS: A total of 22 articles were selected, with 3 280 cases in the intervention group and 3 281 cases in the control group. The results of pooled effect size showed that probiotic supplementation during pregnancy and/or infancy significantly reduced the incidence rate of atopic dermatitis (RR=0.81, 95%CI: 0.70-0.93, P<0.05). According to the subgroup analysis, the intervention with Lactobacillus and Bifidobacterium had a significant effect (RR=0.68, 95%CI: 0.52-0.90, P<0.05); probiotic supplementation during both pregnancy and infancy also had a significant effect (RR=0.77, 95%CI: 0.66-0.90, P<0.05); probiotic supplementation during pregnancy and/or infancy had a better effect in preventing atopic dermatitis in children aged ≤2 years than in those aged >2 years (RR=0.74, 95%CI: 0.61-0.90, P<0.05); probiotic supplementation had a significant effect in Australia (RR=0.83, 95%CI: 0.73-0.96, P<0.05) and Europe/the United States (RR=0.74, 95%CI: 0.61-0.91, P<0.05). Heterogeneity was mainly due to follow-up time (I2=62.7%) and time of probiotic supplementation (I2=53.5%). CONCLUSIONS: Probiotic supplementation during pregnancy and infancy helps to prevent atopic dermatitis in children, and mixed Lactobacillus-Bifidobacterium intervention has a better effect.


Assuntos
Dermatite Atópica , Probióticos , Bifidobacterium , Pré-Escolar , Feminino , Humanos , Lactente , Lactobacillus , Gravidez
5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(11): 3220-3, 2015 Nov.
Artigo em Zh | MEDLINE | ID: mdl-26978940

RESUMO

In order to measure the dynamic wavelength of semiconductor lasers under current tuning, an improved method of fi- ber delay self-heterodyne interferometer was proposed. The measurement principle, as well the beat frequency and dynamic wavelength of recursive relations are theoretically analyzed. The application of the experimental system measured the dynamic wavelength characteristics of distributed feedback semiconductor laser and the static wavelength characteristics measurement by the spectrometer. The comparison between the two values indicates that both dynamic and static wavelength characteristic with the current tuning are the similar non-linear curve. In 20-100 mA current tuning range, the difference of them is less than 0.002 nm. At the same time, according to the absorption lines of CO2 gas, and HITRAN spectrum library, we can identify the dynamic wavelength of the laser. Comparing it with dynamic wavelength calculated by the beat signal, the difference is only 0.001 nm, which verifies the reliability of the experimental system to measure the dynamic wavelength.

6.
Bioact Mater ; 40: 34-46, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38910967

RESUMO

For gastrointestinal anastomosis, metallic biodegradable staples have a broad application potential. However, both magnesium and zinc alloys have relatively low strength to withstand the repeated peristalsis of the gastrointestinal tract. In this study, we developed a novel kind of biodegradable high-nitrogen iron (HN-Fe) alloy wires (0.23 mm), which were fabricated into the staples. The tensile results showed that the ultimate tensile strength and elongation of HN-Fe wires were 1023.2 MPa and 51.0 %, respectively, which was much higher than those of other biodegradable wires. The degradation rate in vitro of HN-Fe wires was slightly higher than that of pure Fe wires. After 28 days of immersion, the tensile strength of HN-Fe wires remained not less than 240 MPa, meeting the clinical requirements. Furthermore, sixteen rabbits were enrolled to conduct a comparison experiment using HN-Fe and clinical Ti staples for gastroanastomosis. After 6 months of implantation, a homogeneous degradation product layer on HN-Fe staples was observed and no fracture occurred. The degradation rate of HN-Fe staples in vivo was significantly higher than that in vitro, and they were expected to be completely degraded in 2 years. Meanwhile, both benign cutting and closure performance of HN-Fe staples ensured that all the animals did not experience hemorrhage and anastomotic fistula during the observation. The anastomosis site healed without histopathological change, inflammatory reaction and abnormal blood routine and biochemistry, demonstrating good biocompatibility of HN-Fe staples. Thereby, the favorable performance makes the HN-Fe staples developed in this work a promising candidate for gastrointestinal anastomosis.

7.
ACS Biomater Sci Eng ; 10(9): 5723-5738, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39163588

RESUMO

The repair and regeneration of maxillofacial bone defects are major clinical challenges. Titanium (Ti)-magnesium (Mg) composites are a new generation of revolutionary internal fixation materials encompassing the mechanical strength and bioactive advantages of Ti and Mg alloys, respectively. This study was aimed to construct a Ti-Mg composite internal plate/screw fixation system to fix and repair bone defects. Further, the effects of different internal fixation systems on bone repair were analyzed through radiological and histological analyses. Notably, Ti6Al4V with rolled Mg foil was used as the experimental group, and a bone defect model of transverse complete amputation of the ulna in rabbits similar to the clinical condition was established. The internal fixation system with the highest osteogenic efficiency was selected based on in vivo results, and the direct and indirect bone repair abilities of the selected materials were evaluated in vitro. Notably, the thin Mg foil-Ti6Al4V internal fixation system exhibited the best fixation effect in the bone defect model and promoted the formation of new bone and early healing of bone defect areas. In vitro, the thin Mg foil-Ti6Al4V composite enhanced the activity of MC3T3-E1 cells; promoted the proliferation, adhesion, extension, and osteogenic differentiation of MC3T3-E1 cells; and regulated new bone formation. Further, it also promoted the polarization of RAW264.7 cells to M2 macrophages, induced the osteogenic immune microenvironment, and indirectly regulated the bone repair process. Therefore, a internal fixation system holds a promising potential for the internal fixation of maxillofacial bone defects. Our findings provide a theoretical and scientific basis for the design and clinical application of Ti-Mg internal fixation systems.


Assuntos
Ligas , Magnésio , Osteogênese , Titânio , Animais , Titânio/química , Magnésio/farmacologia , Coelhos , Camundongos , Ligas/química , Osteogênese/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fixação Interna de Fraturas/métodos , Diferenciação Celular/efeitos dos fármacos , Fixadores Internos
8.
Front Microbiol ; 14: 1196451, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37426015

RESUMO

Background: The influenza virus poses a significant threat to global public health due to its high mutation rate. Continuous surveillance, development of new vaccines, and public health measures are crucial in managing and mitigating the impact of influenza outbreaks. Methods: Nasal swabs were collected from individuals with influenza-like symptoms in Jining City during 2021-2022. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect influenza A viruses, followed by isolation using MDCK cells. Additionally, nucleic acid detection was performed to identify influenza A H1N1, seasonal H3N2, B/Victoria, and B/Yamagata strains. Whole-genome sequencing was conducted on 24 influenza virus strains, and subsequent analyses included characterization, phylogenetic construction, mutation analysis, and assessment of nucleotide diversity. Results: A total of 1,543 throat swab samples were collected. The study revealed the dominance of the B/Victoria influenza virus in Jining during 2021-2022. Whole-genome sequencing showed co-prevalence of B/Victoria influenza viruses in the branches of Victoria clade 1A.3a.1 and Victoria clade 1A.3a.2, with a higher incidence observed in winter and spring. Comparative analysis demonstrated lower similarity in the HA, MP, and PB2 gene segments of the 24 sequenced influenza virus strains compared to the Northern Hemisphere vaccine strain B/Washington/02/2019. Mutations were identified in all antigenic epitopes of the HA protein at R133G, N150K, and N197D, and the 17-sequence antigenic epitopes exhibited more than 4 amino acid variation sites, resulting in antigenic drift. Moreover, one sequence had a D197N mutation in the NA protein, while seven sequences had a K338R mutation in the PA protein. Conclusion: This study highlights the predominant presence of B/Victoria influenza strain in Jining from 2021 to 2022. The analysis also identified amino acid site variations in the antigenic epitopes, contributing to antigenic drift.

9.
Biomater Transl ; 2(3): 248-256, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35836651

RESUMO

The lack of bioactivity of conventional medical materials leads to low osseointegration ability that may result in the occurrence of aseptic loosening in the clinic. To achieve high osseointegration, surface modifications with multiple biofunctions including degradability, osteogenesis, angiogenesis and antibacterial properties are required. However, the functions of conventional bioactive coatings are limited. Thus novel biofunctional magnesium (Mg) coatings are believed to be promising candidates for surface modification of implant materials for use in bone tissue repair. By physical vapour deposition, many previous researchers have deposited Mg coatings with high purity and granular microstructure on titanium alloys, polyetheretherketone, steels, Mg alloys and silicon. It was found that the Mg coatings with high-purity could considerably control the degradation rate in the initial stage of Mg alloy implantation, which is the most important problem for the application of Mg alloy implants. In addition, Mg coating on titanium (Ti) implant materials has been extensively studied both in vitro and in vivo, and the results indicated that their corrosion behaviour and biocompatibility are promising. Mg coatings continuously release Mg ions during the degradation process, and the alkaline environment caused by Mg degradation has obvious antibacterial effects. Meanwhile, the Mg coating has beneficial effects on osteogenesis and osseointegration, and increases the new bone-regenerating ability. Mg coatings also exhibit favourable osteogenic and angiogenic properties in vitro and increased long-term bone formation and early vascularization in vivo. Inhibitory effects of Mg coatings on osteoclasts have also been proven, which play a great role in osteoporotic patients. In addition, in order to obtain more biofunctions, other alloying elements such as copper have been added to the Mg coatings. Thus, Mg-coated Ti acquired biofunctions including degradability, osteogenesis, angiogenesis and antibacterial properties. These novel multi-functional Mg coatings are expected to significantly enhance the long-term safety of bone implants for the benefit of patients. This paper gives a brief review of studies of the microstructure, degradation behaviours and biofunctions of Mg coatings, and directions for future research are also proposed.

10.
ACS Biomater Sci Eng ; 7(6): 2774-2782, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-34030441

RESUMO

Biliary-stent implantation has become an effective treatment for patients with malignant obstructive jaundice caused by hepatobiliary carcinoma. Stent restenosis due to tumor ingrowth is a common problem. In this study, we assessed a biodegradable form of magnesium (Mg) for its anticancer effect on hepatobiliary carcinoma, compared to the conventional stent material of titanium (Ti). The results showed that a Mg extract inhibited proliferation and induced apoptosis in human cholangiocarcinoma cells, while a Mg plate inhibited cell adhesion and destroyed the cytoskeleton in the process of biodegradation. In animal experiments with H22 tumor-bearing mice, Mg wires implanted in tumors exhibited an inhibitory effect on their growth compared with Ti wires. Fifteen days after implantation of metal wires, the mean tumor volume and weight in the Mg group were significantly smaller than in the Ti group. We observed the dynamic-degradation process of Mg wires in tumors and generation of H2 gas via soft X-ray photography and scanning electron microscopy. Histopathological analyses showed that apoptosis of tumor cells around Mg wires significantly increased, expression of carbonic anhydrase 9 significantly decreased, and the upstream protein hypoxia-inducible factor 1-alpha also decreased to some extent. Taken together, these results indicated that biodegradable Mg had antitumor properties both in vitro and in vivo, suggesting its potential application as a novel material for biodegradable biliary stents.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Animais , Ductos Biliares Intra-Hepáticos , Humanos , Magnésio/farmacologia , Camundongos , Stents
11.
Iran J Pharm Res ; 19(3): 217-230, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33680024

RESUMO

To explore novel antitumor agents with high efficiency and low toxicity, riluzole alkyl derivatives (4a-4i) were synthesized. Their anti-proliferative activities against HeLa, HepG2, SP2/0, and MCF-7 cancer cell lines were assessed by the CCK-8 assay and compared with human normal liver (LO2) cells. Most of them showed potent cytotoxic effects against four human tumor cell lines and low toxic to LO2 cells. In particular, 2-(N-ethylamine)-6-trifluoromethoxy- benzothiazole (4a) showed a IC50 value of 7.76 µmol/L in HeLa cells and was found to be nontoxic to LO2 cells up to 65 µmol/L. Furthermore, flow cytometry indicated that 4a could induce remarkable early apoptosis and G2/M cell cycle arrest in HeLa cells. It also impaired the migration ability of HeLa cells in wound healing assays. Western blot results demonstrated that 4a suppressed Bcl-2 protein expression but increased the level of Bax in HeLa cells, and elevated the Bax/Bcl-2 expression ratio. These new findings suggest that 4a exhibited beneficially anti-cervical cancer effect on HeLa cells by inducing HeLa cell apoptosis.

12.
Mol Brain ; 13(1): 22, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32070382

RESUMO

The anterior cingulate cortex (ACC) serves as a critical hub for the anxiety and pain perception. The large-conductance Ca2+-activated potassium channels, or BKCa channels, are ubiquitously expressed throughout the central nervous system including the cingulate cortex. However, what changes of cortical BKCa channels undergo in the ACC remains unknown in pain-related anxiety. In the present study, a significant upregulation of synaptic and non-synaptic BKCa channel accessory ß4 subunits in the ACC was accompanied with pain-associated anxiety-like behaviors in the chronic compression of multiple dorsal root ganglia (mCCD) of the rat. NS1619, an opener of BKCa channels, significantly rescued the alteration of fAHP and AP duration of ACC pyramidal neurons in mCCD rats. The mRNA expression of BKCa ß4 subunits was extremely upregulated in the ACC after mCCD with the increased amount of both synaptic and non-synaptic BKCa ß4 subunit protein. Meanwhile, NS1619 reversed the enhanced AMPA receptor-mediated spontaneous excitatory postsynaptic current (sEPSC) frequency and the attenuated PPR of ACC neurons in mCCD rats. Local activation of BKCa channels in the ACC reversed mechanical allodynia and anxiety-like behaviors. These results suggest that the upregulation of postsynaptic and presynaptic BKCa ß4 subunit may contribute to neuronal hyperexcitability and the enhanced synaptic transmission in the ACC in neuropathic pain state, and then may result in anxiety-like behavior induced by neuropathic pain.


Assuntos
Ansiedade/metabolismo , Giro do Cíngulo/metabolismo , Hiperalgesia/metabolismo , Subunidades beta do Canal de Potássio Ativado por Cálcio de Condutância Alta/genética , Proteínas do Tecido Nervoso/genética , Regulação para Cima , Animais , Ansiedade/fisiopatologia , Comportamento Animal , Benzimidazóis/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Gânglios Espinais/fisiopatologia , Giro do Cíngulo/efeitos dos fármacos , Giro do Cíngulo/fisiopatologia , Hiperalgesia/complicações , Hiperalgesia/fisiopatologia , Indóis/farmacologia , Ativação do Canal Iônico/efeitos dos fármacos , Subunidades beta do Canal de Potássio Ativado por Cálcio de Condutância Alta/metabolismo , Masculino , Proteínas do Tecido Nervoso/metabolismo , Neuralgia/complicações , Neuralgia/metabolismo , Neuralgia/fisiopatologia , Células Piramidais/efeitos dos fármacos , Células Piramidais/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Receptores de AMPA/metabolismo , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Regulação para Cima/efeitos dos fármacos
13.
Nat Commun ; 11(1): 4666, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938943

RESUMO

Intercalated discs (ICD), specific cell-to-cell contacts that connect adjacent cardiomyocytes, ensure mechanical and electrochemical coupling during contraction of the heart. Mutations in genes encoding ICD components are linked to cardiovascular diseases. Here, we show that loss of Xinß, a newly-identified component of ICDs, results in cardiomyocyte proliferation defects and cardiomyopathy. We uncovered a role for Xinß in signaling via the Hippo-YAP pathway by recruiting NF2 to the ICD to modulate cardiac function. In Xinß mutant hearts levels of phosphorylated NF2 are substantially reduced, suggesting an impairment of Hippo-YAP signaling. Cardiac-specific overexpression of YAP rescues cardiac defects in Xinß knock-out mice-indicating a functional and genetic interaction between Xinß and YAP. Our study reveals a molecular mechanism by which cardiac-expressed intercalated disc protein Xinß modulates Hippo-YAP signaling to control heart development and cardiac function in a tissue specific manner. Consequently, this pathway may represent a therapeutic target for the treatment of cardiovascular diseases.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas com Domínio LIM/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Cardiomiopatia Dilatada/genética , Comunicação Celular , Proteínas de Ciclo Celular/genética , Proliferação de Células , Proteínas do Citoesqueleto/genética , Proteínas de Ligação a DNA/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Ventrículos do Coração/crescimento & desenvolvimento , Via de Sinalização Hippo , Proteínas com Domínio LIM/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Miócitos Cardíacos/citologia , Miócitos Cardíacos/patologia , Neurofibromina 2/genética , Neurofibromina 2/metabolismo , Proteínas Nucleares/genética , Transdução de Sinais , Proteínas de Sinalização YAP
15.
Huan Jing Ke Xue ; 38(10): 4100-4107, 2017 Oct 08.
Artigo em Zh | MEDLINE | ID: mdl-29965193

RESUMO

The diurnal variations in ozone concentrations in the summer were studied using the temperature, wind speed and direction, total cloud cover, and solar radiation intensity data collected in Langfang, China. The ratio of volatile organic compounds to nitrogen oxides (VOCs/NOx) and the EKMA curve were studied to analyze the sensitivity of ozone formation. The results showed that:① The ozone generation rate and ozone concentrations were positively correlated with the solar radiation intensity with Pearson correlation coefficients of 0.61 and 0.48, respectively. Both the ozone generation rate and the solar radiation intensity reached their peak at about 12:00, while the ozone concentration reached its peak at about 16:00, which lagged behind the peak of the solar radiation intensity by 4 h. ② The correlation coefficient between the ozone generation rate and the temperature was 0.44, between the ozone concentration and temperature was 0.68. The ozone generation rate and ozone concentrations were inversely correlated with total cloud cover with correlation coefficients of -0.24 and -0.45, respectively. ③ The ozone concentrations in Langfang were high when the winds were from the west, south, or southeast. ④ The ozone concentrations in Langfang were more sensitive to VOCs than to NOx; thus, they can be reduced efficiently by controlling the VOCs emissions.

16.
J Agric Food Chem ; 63(14): 3694-703, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25805337

RESUMO

Polyphenols and caffeoylquinic acid (CQA) derivatives (3-CQA, 4-CQA, 5-CQA, 3,4-diCQA, 3,5-diCQA, and 4,5-diCQA) were prepared from Ilex kudingcha C.J. Tseng, and their effects and mechanisms on the activities of α-glucosidase from Saccharomyces cerevisiae were investigated in the present study. As results, the IC50 values for CQA derivatives were 0.16-0.39 mg/mL, and the inhibition mode of CQA derivatives was noncompetitive. On the basis of fluorescence spectroscopy and circular dichroism spectroscopy data, the binding constants and number of binding sites were calculated to be 10(6)-10(8) M(-1) and 1.42-1.87, respectively. CQA derivatives could bind to the enzyme mainly through hydrophobic interaction, altering the microenvironment and molecular conformation of the enzyme, thus decreasing the catalytic activity. To the authors' knowledge, this is the first report on α-glucosidase inhibitory mechanism by CQA derivatives from I. kudingcha, and the findings suggest a potential use of kudingcha as functional foods for the prevention and treatment of diabetes and related symptoms.


Assuntos
Inibidores de Glicosídeo Hidrolases/química , Ilex/química , Extratos Vegetais/química , Ácido Quínico/análogos & derivados , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Saccharomyces cerevisiae/enzimologia , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Cinética , Estrutura Molecular , Extratos Vegetais/isolamento & purificação , Ácido Quínico/química , Ácido Quínico/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/química , alfa-Glucosidases/química
17.
Brain Res ; 1022(1-2): 234-43, 2004 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-15353234

RESUMO

In vivo magnetic resonance imaging (MRI) was used to observe the effect of acutobin, a purified thrombin-like enzyme (TLE), isolated from the snake venom of Deinagkistrodon acutus, on MRI-detected brain lesion volume and tissue perfusion deficit in a hyperglycemic rat right middle cerebral artery occlusion/reperfusion (MCAO/R) model. Acutobin (0.75 U/ml) was intravenously injected with a dosage of 2.5 U/kg body weight 30 min after MCAO (MCAO duration=60 min) and again 24 h after reperfusion. Multislice diffusion weighted imaging (DWI) and single-slice dynamic bolus tracking gradient echo (GE) imaging were sequentially acquired before and after MCAO/R. DWI-detected lesion volume was significantly (p<0.05) reduced by 24-31% from 350+/-45, 369+/-45 and 374+/-36 mm(3) in the saline-treated group to 239+/-17, 282+/-26 and 259+/-32 mm(3) at 3, 4 and 24 h after reperfusion in the acutobin-treated group, respectively. Residual cerebral blood flow (CBF) in the right hemisphere recovered and remained at approximately 80% of normal perfusion over the measurement period in the acutobin-treated group, compared to approximately 40% in the saline-treated group. Mortality at 1 week after MCAO/R in the acutobin-treated group was significantly lower (25% mortality) than the saline control group (85% mortality). Our results indicate that acutobin improves brain tissue perfusion and reduces infarct volume and mortality in the hyperglycemic rat MCAO/R model.


Assuntos
Lesões Encefálicas/tratamento farmacológico , Fibrinolíticos/uso terapêutico , Hiperglicemia/fisiopatologia , Infarto da Artéria Cerebral Média/fisiopatologia , Reperfusão , Animais , Lesões Encefálicas/etiologia , Lesões Encefálicas/patologia , Mapeamento Encefálico , Circulação Cerebrovascular/efeitos dos fármacos , Venenos de Crotalídeos/uso terapêutico , Modelos Animais de Doenças , Hiperglicemia/tratamento farmacológico , Imageamento por Ressonância Magnética/métodos , Masculino , Ratos , Ratos Sprague-Dawley , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fluxo Sanguíneo Regional/fisiologia , Trombina/uso terapêutico , Fatores de Tempo
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