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1.
This study describes the details of how to construct a three-dimensional (3D) finite element model of a maxillary first premolar tooth based on micro-CT data acquisition technique, MIMICS soft- ware and ANSYS software. The tooth was scanned by micro-CT, in which 1295 slices were obtained and then 648 slices were selected for modeling. The 3D surface mesh models of enamel and dentin were created by MIMICS (STL file). The solid mesh model was constructed by ANSYS. After the material properties and boundary conditions were set, a loading analysis was performed to demonstrate the ap- plicableness of the resulting model. The first and third principal stresses were then evaluated. The re- suits showed that the number of nodes and elements of the finite element model were 56 618 and 311801, respectively. The geometric form of the model was highly consistent with that of the true tooth, and the deviation between them was ~).28%. The loading analysis revealed the typical stress patterns in the contour map. The maximum compressive stress existed in the contact points and the maximum tensile stress existed in the deep fissure between the two cusps. It is concluded that by using the micro-CT and highly integrated software, construction of the 3D finite element model with high quality will not be difficult for clinical researchers.  相似文献   

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BACKGROUND: Rheumatoid arthritis (RA), as a common systemic inflammatory autoimmune disease, affects approximately 1 in 100 individuals. Effective treatment for RA is not yet available because current research does not have a clear understanding of the etiology and pathogenesis of RA. Xinfeng Capsule, a patent Chinese herbal medicine, has been used in the treatment of RA in recent years. Despite its reported clinical efficacy, there are no large-sample, multicenter, randomized trials that support the use of Xinfeng Capsule for RA. Therefore, we designed a randomized, double-blind, multicenter, placebo-controlled trial to assess the efficacy and safety of Xinfeng Capsule in the treatment of RA. METHODS AND DESIGN: This is a 12-week, randomized, placebo-controlled, double-blind, multicenter trial on the treatment of RA. The participants will be randomly assigned to the experimental group and the control group at a ratio of 1:1. Participants in the experimental group will receive Xinfeng Capsule and a pharmaceutical placebo (imitation leflunomide). The control group will receive leflunomide and an herbal placebo (imitation Xinfeng Capsule). The American College of Rheumatology (ACR) Criteria for RA will be used to measure the efficacy of the Xinfeng Capsule. The primary outcome measure will be the percentage of study participants who achieve an ACR 20% response rate (ACR20), which will be measured every 4 weeks after randomization. Secondary outcomes will include the ACR50 and ACR70 responses, the side effects of the medications, the Disease Activity Score 28, RA biomarkers, quality of life, and X-rays of the hands and wrists. The first four of the secondary outcomes will be measured every 4 weeks and the others will be measured at baseline and after 12 weeks of treatment. DISCUSSION: The result of this trial will help to evaluate whether Xinfeng Capsule is effective and safe in the treatment of RA. TRIAL REGISTRATION: This trial has been registered in ClinicalTrials.gov. The identifier is N CT01774877.  相似文献   

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Objective To examine the effects of chlorogenic acid (CGA) on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α (PPAR-α) in these effects. Methods Twenty male golden hamsters were randomly divided into CGA treatment group (n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily), and control group (n=10, given PBS i.p. at the average volume of the treatment group). Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-α were determined. Results Eight weeks after treatment with CGA, the levels of fasting serum triglyceride (TG), free fatty acid (FFA), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), glucose (FSG), and insulin (FSI) were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase (HL) lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase (LPL) in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-α. Conclusion CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-α facilitated lipid clearance in liver and improved insulin sensitivity.  相似文献   

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Patients with a diagnosis of polycystic ovary syndrome (PCOS) are on the rise. About 4%-12% of women are currently estimated to have this condition. It is hypothesized that PCOS appears in women who have long-standing insulin resistance (1R), which leads to high androgen and testosterone levels; this ultimately disrupts their menstrual cycles. Some researchers attribute IR to genetic factors, although there have been only minute changes in the human genome in the past 20 000 years. However, even with a stable gene pool, genes can be turned on and offby the environment, food and air quality and toxin exposure.  相似文献   

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Background An zidovudine (AZT)-substitution regimen containing 24-week stavudine (d4T) followed by long-term AZT for HIV therapy is potential to trade off short-term AZT-related anemia and long-term risks associated with d4T in resourcelimited settings.However,evidence is scarce.This study aims to assess the efficacy and safety of AZT-substitution regimen,aiming to find a regimen with better efficacy,less adverse events,and more affordability in resource-limited settings.Methods This prospective,multicenter study enrolled 499 (190 on d4T regimen,172 on AZT regimen,and 137 on AZT-substitution regimen) HIV-1-infected subjects who initiated combined antiretroviral therapy and attended follow-up visits over 96 weeks from 2009 to 2011.Lamivudine (3TC) and either nevirapine (NVP) or efavirenz (EFV) were the other two drugs in the antiretroviral regimens.Virologic and immunologic responses and adverse events were monitored at baseline and at weeks 4,12,24,36,48,60,72,84,and 96.Results In terms of hematological adverse effects,AZT-substitution group had similar safety profiles to d4T group and was superior to AZT group.In comparison with AZT-substitution group,AZT group was associated with higher risk of developing anemia (adjusted hazard ratio (aHR)for anemia ≥ grade Ⅱ,8.44,95% CI 1.81-39.46) and neutropenia (aHR for neutropenia ≥ grade Ⅱ,1.86,95% CI 1.19-2.93).The prevalence of lipodystrophy in d4T group was 19.5%,while that in AZT-substitution group was zero.As to antiretroviral efficacy,these three groups showed no differences.Conclusion AZT-substitution regimen provides a relatively safe and effective first-line antiretroviral strategy in resource-limited settings.  相似文献   

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The central nervous system (CNS) plays a key regulatory role in glucose homeostasis. In particular, the brain is important in initiating and coordinating protective counterregulatory responses when blood glucose levels fall. This may due to the metabolic dependency of the CNS on glucose, and protection of food supply to the brain. In healthy subjects, blood glucose is normally maintained within a relatively narrow range. Hypoglycemia in diabetic patients can increase the risk of complications, such as heart disease and diabetic peripheral neuropathy. The clinical research finds that the use of traditional Chinese medicine (TCM) has a positive effect on the treatment of hypoglycemia. Here the authors reviewed the current understanding of sensing and counterregulatory responses to hypoglycemia, and discuss combining traditional Chinese and Western medicine and the theory of iatrogenic hypoglycemia in diabetes treatment. Furthermore, the authors clarify the feasibility of treating hypoglycemia on the basis of TCM theory and CNS and have an insight on its clinical practice.  相似文献   

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Intraditional Chinese medicine (TCM),the so-called津液refers to all the fluid and liquid flowingand maintaining inside the human body.In Chineselanguage,津液is a phrase composed of twoChinese characters which describes two differentkinds of fluid or liquid in the human body .According to the theory of TCM,津refers to thepart of fluid that is thin in texture and flowss moothly inside the body while液refers to thepart of fluid that is thick in texture and mainlymaintains in the joints of the body to nourish andlubr...  相似文献   

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Background We previously demonstrated that the aqueous extract of the Schizandra chinensis fruit (AESC) ameliorated Cd-induced depletion of monoamine neurotransmitters in the brain through antioxidant activity.In the present study,we investigated the effect of AESC on anxiety-like behavior and the levels of norepinephrine and 3-methoxy-4-hydroxyphenylglycol (a metabolite of norepinephrine) in different brain regions during ethanol withdrawal in rats.Methods Male Sprague-Dawley rats were treated with 3 g/kg of ethanol (20%,w/v) or saline by daily intraperitoneal injection for 28 days followed by three days of withdrawal.During withdrawal,rats were given AESC (100 mg.kg 1.d-1 or 300 mg.kg 1·d1,P.O.) once a day for three days.Thirty minutes after the final dose of AESC,the anxiogenic response was evaluated using an elevated plus maze,and the plasma corticosterone levels were examined by radioimmunoassay.Meanwhile,the concentrations of norepinephrine and 3-methoxy-4-hydroxy-phenylglycol in the hypothalamic paraventricular nucleus and hippocampus were also measured by high performance liquid chromatography.Results Rats undergoing ethanol withdrawal exhibited substantial anxiety-like behavior,which was characterized by both the decrease in time spent in the open arms of the elevated plus maze and the increased level of corticosterone secretion,which were greatly attenuated by doses of AESC in a dose-dependent manner.The high performance liquid chromatography analysis revealed that ethanol withdrawal significantly increased norepinephrine and 3-methoxy-4-hydroxy-phenylglycol levels in the hypothalamic paraventricular nucleus,while not significantly altering them in the hippocampus.Similar to the results from the elevated plus maze test,the AESC significantly inhibited the elevation of norepinephrine and its metabolite in the hypothalamic paraventricular nucleus in a dose-dependent manner.Conclusions These results suggest that AESC attenuates anxiety-like behavior induced by ethanol withdrawal through modulation of the hypothalamic norepinephrine system in the brain.  相似文献   

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The transforming growth factor β1(TGF-β1) and CD8-positive T cells are two important immune factors that function at opposite directions. The purpose of this study was to verify the relationship between the two factors and their associations with long-term effects of adjuvant chemotherapy or endocrine therapy in breast cancer. Expression of TGF-β1 precursor and CD8 was immunohistochemically detected on surgically-obtained tumor samples of 130(stageⅠ–Ⅲ) invasive breast carcinomas from Chinese subjects, who were followed up for a mean time of 112 months. Interstitial CD8-positive cells and TGF-β1 precursor-positive cells adjacent to tumor nests were counted. Infiltration of CD8-positive lymphocytes into tumor nests and TGF-β1 precursor expression in tumor cells were observed and survival analysis was performed. Our results showed that density of interstitial CD8-positive lymphocytes was an independent adverse prognostic factor for distant disease-free survival(DDFS)(HR=8.416, 95% CI=1.636–43.292, P=0.011) in hormone receptor-positive patients who were on adjuvant endocrine therapy. For breast cancer patients who did not receive adjuvant chemotherapy, those without infiltration of CD8-positive cells into tumor nests had a shorter overall survival(OS) than their counterparts with CD8-positive cell infiltration into tumor nests(Log-Rank, P=0.003). But OS of patients without infiltration of CD8-positive cells into tumor nests was significantly prolonged by adjuvant chemotherapy(Log-Rank, P=0.013) and paralleled that of patients with CD8-positive cell infiltration. Although OS was shorter in the tumor cell TGF-β1 precursor(t-TGF-β1-pre)-positive patients than in the negative patients in patients without recieiving chemotherapy(P=0.053), OS of t-TGF-β1-pre-positive patients was significantly prolonged by adjuvant chemotherapy(P=0.035) and was longer than that of t-TGF-β1-pre-negative patients. Analysis showed that t-TGF-β1-pre was an independent positive prognostic factor for DDFS(HR=0.392 95% CI=0.157–0.978, P=0.045) in patients who received adjuvant chemotherapy. This study suggested that density of interstitial CD8-positive lymphocytes was of prognostic value in hormone receptor-positive patients who received adjuvant endocrine therapy. Our study verified that adverse immunologic signatures consisting of absence of CD8-positive cells in tumor nests or expression of TGF-β1 precursor in tumor cells in breast cancer were associated with worse prognosis and significantly improved long-term survival with adjuvant chemotherapy, respectively.  相似文献   

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Conventional ultrasound (US) is the most widely used imaging modality in routine clinical practice worldwide. The limitations of conventional ultrasound in the detection of aortic lesions versus multi-slice computed tomography angiography (MS-CTA) are well known.  相似文献   

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Epistaxis remains one of the most common otolaryngology emergencies. Severe epistaxis may be caused by internal carotid artery (ICA) pseudoaneurysm or cavernous fistula, which is clinically rare but life threatening if it is not diagnosed and treated timely. Most ICA pseudoaneurysms are mainly caused by trauma with few other causes. From January 1998 to December 2005, a total of 8 cases with non-traumatic carotid artery pseudoaneurysm were correctly diagnosed through digital subtraction angiography (DSA) in Ganzhou People's Hospital. The patients had suffered from serious nose bleeding repeatedly and had been resistant to routine treatments.  相似文献   

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Background Few studies have investigated perioperative major adverse cardiac events (MACEs) in elderly Chinese patients with coronary heart disease (CHD) undergoing noncardiac surgery.This study examin...  相似文献   

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Objective To observe the different impacts of electrolytic iron, FeSO4, and NaFeEDTA on body iron store of anemic school students. Methods Four hundreds anemic students at the age of 11-18 years were divided into four groups. Of which, three consumed different iron fortificants from wheat flour as food vehicle for six months and one consumed non-fortified flour (control). The fortification level of electrolytic iron, FeSO4, and NaFeEDTA was 60 mg Fe/kg, 30 mg Fe/kg, and 20 mg Fe/kg, respectively. Blood samples were collected at 0, 2, 4, and 6 months and hemoglobin (Hb), serum ferritin (SF), and transferrin receptor (TfR) were measured. Results The hemoglobin levels in three intervention groups increased, the increments of Hb in the NaFeEDTA group were significantly higher than that in the other groups. SF and TfR levels increased in the tested groups and body iron store in the NaFeEDTA group was higher than that in the other groups. These parameters did not show any significant changes in the control group. Conclusion NaFeEDTA and FeSO4 tortified wheat flour has positive impacts on iron status in anemic students and NaFeEDTA is more effective than FeSO4, while electrolytic iron is less effective in improving iron store in anemic students.  相似文献   

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A7.0-magnitude earthquake took place in Lushan county,Ya'an in southwest China's Sichuan Province at 8:02 a.m.Beijing time,April 20,2013.The epicenter was located approximately 110 km away from Chengdu,at 30.3 degrees north latitude and 103.0 degrees east longitude.The earthquake caused 196 deaths and left 21 missing and 11 470 injured.  相似文献   

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Background Pulmonary hypertension (PH) is a common complication of congenital heart disease (CHD).Although risk stratification is vital for prognosis and therapeutic guidance,the need for understanding the role of novel biomarkers cannot be overlooked.The aim of the present study was to investigate the changes of homocysteine and hydrogen sulfide levels and find potential biomarkers for early detection and treatment.Methods Between September 2012 and April 2013,we prospectively collected data on 158 pediatric patients with left to right shunt CHD at our institution.Standard right heart catheterizations were performed in all cases.Seventy-seven cases were associated with PH.The levels of homocysteine and hydrogen sulfide were detected with fluorescence polarization immunoassay and a sensitive silver-sulphur electrode,respectively.Enzyme-linked immunosorbent assay was used to determine the expression of methylenetetrahydrofolate reductase (MTHFR),cystathionine β-synthase (CBS),and cystathionine gamma-lyase (CSE).Radioimmunoassays were used to obtain folic acid and vitamin B12 levels.Results The difference in the levels of homocysteine,folic acid,vitamin B12,hydrogen sulfide,as well as the MTHFR and CSE expression between patients with PH and without PH were statistically significant (all P <0.05).Homocysteine had the best sensitivity and specificity to predict PH (P <0.001).Subgroup analysis showed that the levels of homocysteine and hydrogen sulfide,and the expression of CSE and MTHFR between patients with dynamic and obstructive PH were significantly different (all P <0.05).Based on the ROC curve,homocysteine had the best sensitivity and specificity to predict obstructive PH (P=0.032),while CSE had the most significant sensitivity and specificity to predict the dynamic PH (P=0.008).Conclusions Increased levels of homocysteine and decreased levels of hydrogen sulfide were significantly negatively correlated in PH associated with CHD.The underlying mechanism involved the decreased expression of MTHFR and CSE along with vitamin B12 deficiency.Homocysteine and hydrogen sulfide are potential biomarkers to predict PH.  相似文献   

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This study is designed to evaluate antioxidant and antigenotoxic activities of corn tassel extracts(CTTs). The major bioactive components of CTTs include flavonoid, saponin and polysaccharide. The antioxidant properties of the three bioactive components of CTTs were investigated by Ferric Reducing Antioxidant Property(FRAP) and 1, 1-diphenyl-2-picrylhydrazyl(DPPH) assays. The activities of the extracts were determined by assessing the inhibition of mutagenicity of the direct-acting mutagen fenaminosulf, sodium azide, and indirect-acting mutagen 2-aminofluorene using the Ames test(strains TA98 and TA100). The results showed that the extraction rates of flavonoid, saponin, and polysaccharide from the dried corn tassels were 1.67%, 2.41% and 4.76% respectively. DPPH and FRAP assay strongly demonstrated that CTTs had antioxidant properties. CTTs at doses of 625, 1250 and 2500 μg per plate reduced 2-aminofluorene mutagenicity by 12.52%, 28.76% and 36.49% in Salmonella typhimurium TA98 strain assay respectively and by 10.98%, 25.27% and 37.83%, at the same doses in Salmonella typhimurium TA100 assay system, respectively. 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide(MTT) assay showed that the different concentrations of CTTs inhibited the proliferation of MGC80-3 cells in a dose-dependent manner(P0.01). It is concluded that these integrated approaches to antioxidant and antigenotoxicity assessment may be useful to study corn tassel as a natural herbal material.  相似文献   

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