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1.
Materials (Basel) ; 16(12)2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37374600

RESUMO

In this paper, a non-directional short-cut polyvinyl alcohol fiber (PVA), directional carbon-glass fabric woven net, and a combination of these fibers were used to reinforce sprayed cement mortar (named FRCM-SP, FRCM-CN, and FRCM-PN accordingly), and the direct tensile and four-point bending tests of these three types of thin plates were conducted. It was shown that the direct tensile strength of FRCM-PN reached 7.22 MPa under the same cement mortar matrix, which was 175.6% and 198.3% higher than that of FRCM-SP and FRCM-CN, respectively; the ultimate tensile strain of FRCM-PN was 3.34%, which was 65.3% and 1291.7% higher than that of FRCM-SP and FRCM-CN, respectively. Similarly, the ultimate flexural strength of FRCM-PN reached 33.67 MPa, which was 182.5% and 519.6% higher than that of FRCM-SP and FRCM-CN, respectively. In addition, the tensile, bending toughness index, and residual strength factor of FRCM-PN were much higher than those of FRCM-SP and FRCM-CN, indicating that the incorporation of non-directional short-cut PVA fibers improved the interfacial bonding properties between the cement mortar matrix and the fiber yarn and significantly enhanced the toughness and energy dissipation capacity of the sprayed cement mortar. Therefore, the use of a certain amount of non-directional short-cut PVA fibers can improve the interfacial bonding properties between the cement mortar and the fabric woven net while ensuring the spraying performance and significantly improving the reinforcing and toughening effect on the cement mortar to meet the demand for large-area rapid construction and structural seismic reinforcement.

2.
Materials (Basel) ; 15(24)2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36556540

RESUMO

Ultra-high performance concrete (UHPC) is a kind of cement-based material with ultra-high strength, high toughness and excellent durability. However, the tensile strain capacity of UHPC is often below 0.5%, and the mode of single crack failure is the main failure pattern, which limits the development of UHPC. In order to overcome the weakness of the relatively low strain capacity of UHPC, five types of polyethylene (PE) fibers with different geometrical and mechanical parameters (length, diameter and elastic modulus) were added into the matrix, and the corresponding mechanical behavior was investigated. The experimental results showed that the high fiber length and fiber diameter of PE fibers are a benefit for the compressive strength and tensile strength of UHPC. The increase of the fiber diameter and elastic modulus remarkably attributed to the increase in the tensile strain capacity of UHPC. With the increase of the fiber diameter and elastic modulus, the overall energy absorption capacity G and the energy absorption capacity of the substrate prior to the softening section ga of UHPC were both enhanced. The diameter of PE fiber was the main factor affecting the energy consumption of UHPC. Among the five types of PE fiber, PF fiber (PF fiber is PF type polyethylene fiber; Fiber length: 15 mm; Fiber diameter: 27 µm; Elastic Modulus: 117 GPa) is the optimal fiber to increase the tensile mechanical behavior of UHPC.

3.
Materials (Basel) ; 15(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36556779

RESUMO

The clevis-grip tensile test is usually employed to evaluate the mechanical properties of textile reinforced concrete (TRC) composites, which is actually a bond test and is unsuitable for determining reliable design parameters. Thus, the clevis-grip tensile test needs further improvement to obtain foreseeable results concerning TRC tensile behavior. This paper presents the experimental results of twenty-one tension tests performed on basalt TRC (BTRC) thin plates with different test setups, i.e., clevis-grip and improved clevis-grip, and with different textile ratios. The influences of test setups and textile ratios on crack patterns, failure mode, and tensile stress-strain curves with characteristic parameters were analyzed in depth to judge the feasibility of the new test setup. The results indicated that with the new test setup, BTRC composites exhibited textile rupture at failure; in addition, multi-cracks occurred to the BTRC composites as the textile ratio exceeded 1.44%. In this case, the obtained results relied on textile properties, which can be considered reliable for design purposes. The modified ACK model with a textile utilization rate of 50% provided accurate predictions for the tensile stress-strain behavior of the BTRC composite derived from the improved test setup. The proposed test setup enables the adequate utilization of BTRC composite and the reliability of obtained results related to the occurrence of textile rupture; nevertheless, further work is required to better understand the key parameters affecting the textile utilization rate, such as the strength of the concrete matrix.

4.
Zhongguo Zhong Yao Za Zhi ; 46(9): 2298-2303, 2021 May.
Artigo em Chinês | MEDLINE | ID: mdl-34047133

RESUMO

Child Compound Endothelium Corneum(CCEC)has the effects in invigorating the spleen and appetizing the appetite, and dissolving the accumulation of food. The recent studies have proved that it could improve gastrointestinal motility, restore physiological gastrointestinal peristalsis, increase gastrointestinal digestive motility, and enhance appetite. This trial aimed to evaluate its clinical efficacy and safety in the treatment of children's anorexia(spleen-stomach disharmony). A total of 240 children with anorexia in line with the inclusion and exclusion criteria were selected and randomly divided into experimental group and control group, with 120 in each group. Patients in the experimental group took CCEC and Erpixing Granules simulant. Patients in the control group took Erpi-xing Granules and CCEC simulant. After 21 days of treatment, there was no statistical difference in the recovery rate of anorexia, reduced food intake, eating time, weight change, traditional Chinese medicine syndrome effect, single symptom effect, and trace element Zn recovery rate between the two groups. Based on the non-inferiority test, the experimental group was not inferior to the control group in efficacy. How-ever, the effect of CCEC in reducing appetite in children with anorexia was better than that of control drugs(P<0.05). There was no statistical difference in the incidence of adverse events and adverse reactions between the two groups during the trial. This experiment confirmed the efficacy and safety of CCEC in the treatment of children's anorexia(spleen-stomach disharmony), with a safety and re-liability in clinical application. In addition, it was a better choice for children with anorexia who were mainly manifested by reduced appetite. Meanwhile, compared with granule, chewable tablets were more convenient to take in clinic. Therefore, the efficacy and safety of CCEC for the treatment of children's anorexia(spleen-stomach disharmony) were not inferior to those of Erpixing Granules, with a safety and reliability in clnic. However, due to the small sample size of this trial, the efficacy results only show a trend. It is suggested to further carry out a large-sample-size clinical study to define the clinical advantages of CCEC.


Assuntos
Anorexia , Baço , Anorexia/tratamento farmacológico , Criança , Método Duplo-Cego , Endotélio , Humanos , Reprodutibilidade dos Testes , Estômago , Resultado do Tratamento
5.
Food Chem ; 240: 910-916, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28946361

RESUMO

The application of a high-voltage electrostatic field (HVEF) is a novel method for thawing. To determine the effects of HVEF thawing (voltage range: -25kV to 0kV) on myofibrillar protein oxidation and/or denaturation and to provide a theoretical understanding of this process, pork tenderloin was thawed by traditional and HVEF methods. Based on the total sulfhydryl and carbonyl contents, further protein oxidation did not occur during HVEF thawing. It was proposed that the free radical-mediated oxidation of myofibrillar proteins was hindered by HVEF. The results of dynamic rheological analysis, protein aggregation and gel texture studies showed that HVEF thawing, especially -10kV HVEF thawing, led to better indicators than those achieved under air thawing. A higher abundance of proteins extracted from -10kV HVEF-thawed samples compared with air-thawed samples was found. Finally, this study showed that thawing under -10kV conditions did not affect the structure of myofibrillar proteins.


Assuntos
Carne Vermelha , Animais , Fenômenos Químicos , Oxirredução , Proteínas , Reologia , Eletricidade Estática , Suínos
6.
Biochim Biophys Acta Mol Basis Dis ; 1863(6): 1575-1589, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28412321

RESUMO

In response to the daily light-dark (LD) cycle, organisms on Earth have evolved with the approximately 24-h endogenous oscillations to coordinate behavioral and physiological processes, including feeding, sleep, and metabolism homeostasis. Circadian desynchrony triggered by an energy-dense diet rich in fats and fructose is intimately connected with a series of metabolic disorders. Previous studies revealed that (-)-Epigallocatechin-3-gallate (EGCG) could mitigate metabolic misalignment; however, only a few reports have focused on its potential effect on directly manipulating circadian rhythms to ameliorate metabolic syndrome. Our goal was to investigate the regulating effect of EGCG treatment on metabolic misalignment triggered by a high-fat and high-fructose diet (HFFD) associating with the circadian clock. Our results indicated that HFFD treatment partially exhibited poor circadian oscillations of the core clock gene and the clock-controlled gene in the liver and fat relative to the control group. EGCG administration may ameliorate the diet-dependent decline in circadian function by controlling the Sirt1-PGC1αloop, implying the existence of an EGCG-entrainable oscillator. Subsequently, reducing fatty acid synthesis and elevating ß-oxidation in the liver coupled with the increasing brown adipose tissue (BAT) energy expenditure observed in the EGCG group of mice prevented the adipocyte hypertrophy and fat accumulations common to BAT and white adipose tissue (WAT) derived from the HFFD mice. This study is the first to provide compelling evidences that EGCG may ameliorate diet-induced metabolic misalignment by regulating the rhythmic expression of the circadian clock genes in the liver and fat.


Assuntos
Catequina/análogos & derivados , Relógios Circadianos/efeitos dos fármacos , Carboidratos da Dieta/efeitos adversos , Frutose/efeitos adversos , Síndrome Metabólica/tratamento farmacológico , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/patologia , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Animais , Catequina/farmacologia , Carboidratos da Dieta/farmacologia , Frutose/farmacologia , Fígado/metabolismo , Fígado/patologia , Síndrome Metabólica/induzido quimicamente , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Camundongos
7.
Pol J Pathol ; 64(1): 21-7, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23625596

RESUMO

The purpose of this paper was to explore the immunohistochemistry (IHC) results for a cocktail of minichromosome maintenance protein 2 (MCM2) and topoisomerase II (TOP2A), p16INK4a and Ki-67 as biomarkers for the diagnosis of cervical intraepithelial neoplasia (CIN), improving the routine interpretation of cervical histopathology. 133 cases of CIN were collected from the archival data. All routine hematoxylin and eosin (HE)-stained slides of the subjects were re-examined independently by three senior pathologists, to provide a "consensus diagnosis". Immunohistochemistry for the three biomarkers was performed, and the results were reviewed independently of the corresponding archival diagnosis to make a "diagnosis assisted by IHC" by the original pathological practitioners. The diagnosis accordance rate of the archival original diagnosis with the "consensus diagnosis" and the "diagnosis assisted by IHC" with the "consensus diagnosis" were verified by Fisher's exact test. The results showed that raw agreement between the original HE diagnosis and the "consensus diagnosis" was 88.55%, and raw agreement between the "diagnosis assisted by IHC" and the "consensus diagnosis" was 95.78%. The latter was significantly higher than the former (Fisher's exact test, p = 0.023). In conclusion, the three biomarkers had a high degree of sensitivity and specificity, and appear to be a useful and reliable diagnostic adjunct to improve the routine diagnosis, and reduce inter-observer variability in cervical biopsy specimens.


Assuntos
Biomarcadores Tumorais/metabolismo , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/metabolismo , Colo do Útero/metabolismo , Colo do Útero/patologia , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , Pessoa de Meia-Idade , Componente 2 do Complexo de Manutenção de Minicromossomo/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/metabolismo , Adulto Jovem , Displasia do Colo do Útero/metabolismo
9.
PLoS One ; 7(12): e51910, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23284812

RESUMO

Methylphenidate (MPH), commercially called Ritalin or Concerta, has been widely used as a drug for Attention Deficit Hyperactivity Disorder (ADHD). Noteworthily, growing numbers of young people using prescribed MPH improperly for pleasurable enhancement, take high risk of addiction. Thus, understanding the mechanism underlying high level of MPH action in the brain becomes an important goal nowadays. As a blocker of catecholamine transporters, its therapeutic effect is explained as being due to proper modulation of D1 and α2A receptor. Here we showed that higher dose of MPH facilitates NMDA-receptor mediated synaptic transmission via a catecholamine-independent mechanism, in layer V∼VI pyramidal cells of the rat medial prefrontal cortex (PFC). To indicate its postsynaptic action, we next found that MPH facilitates NMDA-induced current and such facilitation could be blocked by σ1 but not D1/5 and α2 receptor antagonists. And this MPH eliciting enhancement of NMDA-receptor activity involves PLC, PKC and IP3 receptor mediated intracellular Ca(2+) increase, but does not require PKA and extracellular Ca(2+) influx. Our additional pharmacological studies confirmed that higher dose of MPH increases locomotor activity via interacting with σ1 receptor. Together, the present study demonstrates for the first time that MPH facilitates NMDA-receptor mediated synaptic transmission via σ1 receptor, and such facilitation requires PLC/IP3/PKC signaling pathway. This novel mechanism possibly explains the underlying mechanism for MPH induced addictive potential and other psychiatric side effects.


Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Metilfenidato/farmacologia , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Receptores de N-Metil-D-Aspartato/agonistas , Receptores sigma/metabolismo , Animais , Cálcio/metabolismo , Catecolaminas/metabolismo , Atividade Motora , Ligação Proteica , Proteína Quinase C/metabolismo , Ratos , Receptores de N-Metil-D-Aspartato/metabolismo , Transdução de Sinais , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Transmissão Sináptica/efeitos dos fármacos , Receptor Sigma-1
10.
Neuropsychopharmacology ; 33(9): 2263-71, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17957212

RESUMO

Stimulation of alpha2-, especially alpha2A-adrenoceptor (AR), in the prefrontal cortex (PFC) produces a beneficial effect on cognitive functions such as working memory. Alpha2-adrenergic agonists like clonidine and guanfacine have been used experimentally and clinically for treatment of psychiatric disorders such as attention-deficit/hyperactivity disorder (ADHD) and schizophrenia. However, the neurophysiological actions of alpha2-ARs in the PFC are poorly understood. In the present study, we recorded field excitatory post-synaptic potential (fEPSP) and evoked excitatory post-synaptic current (eEPSC) in the medial prefrontal cortex (mPFC) of rats, using in vivo field-potential recording and in vitro whole-cell patch-clamp recording techniques, and examined the effects of the alpha2-AR agonist clonidine and the selective alpha2A-AR agonist guanfacine on fEPSP and eEPSC. Systemic or intra-mPFC application of clonidine or guanfacine significantly reduced fEPSP in the mPFC, either in anesthetized or freely moving rats. Consistently, bath-application of guanfacine suppressed eEPSC in layer V/VI pyramidal neurons, and this effect was blocked by the alpha2-AR antagonist yohimbine or the Gi inhibitor NF023. Moreover, treatment with guanfacine had no effect on paired-pulse facilitation (PPF) of fEPSP and eEPSC. The present study provides the first electrophysiological evidence that stimulation of alpha2A-AR inhibits excitatory synaptic transmission in the mPFC through a post-synaptic mechanism.


Assuntos
Potenciais Pós-Sinápticos Excitadores/fisiologia , Inibição Neural/fisiologia , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/fisiologia , Células Piramidais/fisiologia , Receptores Adrenérgicos alfa 2/fisiologia , Agonistas alfa-Adrenérgicos/farmacologia , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Proteínas de Bactérias , Comportamento Animal , Clonidina/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Estimulação Elétrica/métodos , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/efeitos da radiação , Guanfacina/farmacologia , Técnicas In Vitro , Inibição Neural/efeitos dos fármacos , Inibição Neural/efeitos da radiação , Técnicas de Patch-Clamp/métodos , Córtex Pré-Frontal/efeitos dos fármacos , Células Piramidais/efeitos dos fármacos , Células Piramidais/efeitos da radiação , Ratos , Ratos Sprague-Dawley , Proteínas Repressoras , Suramina/análogos & derivados , Suramina/farmacologia , Ioimbina/farmacologia
11.
Cereb Cortex ; 18(7): 1506-20, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17965126

RESUMO

Norepinephrine exerts an important influence on prefrontal cortical functions. The physiological effects of beta-adrenoceptors (beta-ARs) have been examined in other brain regions. However, little is known about beta-AR regulation of synaptic transmission in the prefrontal cortex (PFC). The present study investigated beta-AR modulation of glutamate synaptic transmission in layer V/VI pyramidal cells of the medial PFC (mPFC) of rats. Our results show that 1) isoproterenol (ISO), a selective beta-AR agonist, increased the frequency of spontaneous and miniature excitatory postsynaptic currents (EPSC's); 2) ISO enhancement of miniature EPSC's (mEPSC's) frequency no longer appeared in the presence of the voltage-gated Ca(2+) channel blocker cadmium; 3) ISO enhanced the evoked excitatory postsynaptic currents (eEPSC's) mediated by non-N-methyl-D-aspartic acid receptors (non-NMDA-Rs) and NMDA-Rs. The ISO facilitation of non-NMDA-R eEPSC was blocked by the membrane-permeable cyclic adenosine monophosphate (cAMP) inhibitor Rp-adenosine 3',5'-cyclic monophosphorothioate triethylammonium salt (Rp-cAMPS); 4) ISO enhanced NMDA-induced current, with no effect on glutamate-induced non-NMDA-R current; 5) ISO enhancement of NMDA-R eEPSC and NMDA-induced current was blocked by intracellular application of Rp-cAMPS or the cAMP-dependent protein kinase (PKA) inhibitor PKI(5-24); and 6) ISO suppressed the paired-pulse facilitation of non-NMDA-R and NMDA-R eEPSC's. Taken together, these results provide the first electrophysiological demonstration that beta-AR activation facilitates excitatory synaptic transmission in mPFC pyramidal cells through pre- and postsynaptic mechanisms, probably via cAMP or cAMP/PKA signaling.


Assuntos
Potenciais Pós-Sinápticos Excitadores/fisiologia , Rede Nervosa/fisiologia , Córtex Pré-Frontal/fisiologia , Células Piramidais/fisiologia , Receptores Adrenérgicos beta/metabolismo , Receptores Pré-Sinápticos/fisiologia , Sinapses/fisiologia , Animais , Técnicas In Vitro , Ratos , Ratos Sprague-Dawley
12.
Zhonghua Bing Li Xue Za Zhi ; 34(1): 6-10, 2005 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-15796874

RESUMO

OBJECTIVE: To explore a simplified and reproducible approach for the diagnosis and morphologic prognostication of gastrointestinal stromal tumor (GIST). METHODS: Eighty-five cases of gastrointestinal mesenchymal tumors including 74 cases of GIST, 8 esophageal smooth muscle tumor, 1 rectal leiomyosarcoma, 1 Schwannoma, and 1 malignant fibrous histiocytoma were studied by histological evaluation along with an immunohistochemistry panel including vimentin, CD117 (c-kit), CD34, SMA, desmin and S-100. Clinicopathological correlation was performed in 31 cases of GIST that had accompanied with the available follow-up data. RESULTS: Among 74 GISTs, 34 arose principally from the stomach, 30 from the small intestine, and 10 other cases found in the esophagus, retroperitoneum, mesenterium and omentum. The patients' age ranged from 23 to 80 years (mean 52.5 years), with 45 males and 29 females. Histologically, the tumors composed of either spindle or oval to round cells arranged in interlacing fascicles forming whorls or cellular clusters, cytoplasm generally abundant and eosinophilic. There were 48 cases of spindle cell type, 10 cases of epithelioid cell type and 16 cases of mixed cell type. All 74 cases of GIST were positive for CD117 in a cell membranous pattern, however, some variable staining patterns of CD117 had been noticed in a few cases. In addition, 54 GISTs were also positive for CD34 (72.9%), 25 cases positive for SMA, 5 cases positive for S-100 and 5 cases positive for desmin. According to the Fletcher's scheme, GISTs in this study were divided into 4 subcategories including groups of very low risk of aggressive behavior (3 cases), of low risk (15 cases), of intermediate risk (36 cases) and of high risk (20 cases) respectively. Kaplan-Meier survival analysis of 31 GIST cases whom had been followed up for 16 to 72 months showed a statistically significant difference present among the subcategories (P < 0.01). CONCLUSIONS: GISTs predominantly occur in the middle and old age patients, more common in male, and positive CD117 staining is considered to be the defining marker to differentiate GIST from other mesenchymal tumors of the GI tract. Positive CD34 immun-staining, plus a CD117 positivity, strengthens further a diagnosis of GIST. Subclassification of GISTs using Fletcher's scheme appears to be simple, reproducible, and correlates well with the clinical behavior of the tumor.


Assuntos
Tumores do Estroma Gastrointestinal/imunologia , Tumores do Estroma Gastrointestinal/patologia , Actinas/metabolismo , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antígenos CD34/metabolismo , Intervalo Livre de Doença , Feminino , Seguimentos , Mucosa Gástrica/patologia , Mucosa Gástrica/ultraestrutura , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Proteínas Proto-Oncogênicas c-kit/metabolismo , Proteínas S100/metabolismo , Fatores Sexuais , Estômago/patologia
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