首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   348篇
  免费   21篇
  国内免费   5篇
耳鼻咽喉   2篇
儿科学   7篇
妇产科学   16篇
基础医学   73篇
口腔科学   10篇
临床医学   44篇
内科学   53篇
皮肤病学   11篇
神经病学   28篇
特种医学   8篇
外科学   12篇
综合类   2篇
预防医学   47篇
眼科学   5篇
药学   36篇
中国医学   4篇
肿瘤学   16篇
  2023年   13篇
  2022年   20篇
  2021年   31篇
  2020年   32篇
  2019年   24篇
  2018年   24篇
  2017年   18篇
  2016年   19篇
  2015年   28篇
  2014年   15篇
  2013年   26篇
  2012年   32篇
  2011年   28篇
  2010年   19篇
  2009年   12篇
  2008年   10篇
  2007年   12篇
  2006年   6篇
  2005年   3篇
  2004年   1篇
  2002年   1篇
排序方式: 共有374条查询结果,搜索用时 15 毫秒
31.
The current study aimed to enhance the efficacy of peripheral nerve regeneration using a hydroxyapatite nanoparticle-containing collagen type I hydrogel. A solution of type I collagen, extracted from the rat tails, was incorporated with hydroxyapatite nanoparticles (with the average diameter of ~212 nm) and crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) to prepare the hydrogel. The Schwann cell cultivation on the prepared hydrogel demonstrated a significantly higher cell proliferation than the tissue culture plate, as positive control, after 48 h (n = 3, P < 0.005) and 72 h (n = 3, P < 0.01). For in vivo evaluation, the prepared hydrogel was administrated on the sciatic nerve crush injury in Wistar rats. Four groups were studied: negative control (with injury but without interventions), positive control (without injury), collagen hydrogel and hydroxyapatite nanoparticle-containing collagen hydrogel. After 12 weeks, the administration of hydroxyapatite nanoparticle-containing collagen significantly (n = 4, P < 0.005) enhanced the functional behavior of the rats compared with the collagen hydrogel and negative control groups as evidenced by the sciatic functional index, hot plate latency and compound muscle action potential amplitude measurements. The overall results demonstrated the applicability of the produced hydrogel for the regeneration of peripheral nerve injuries.  相似文献   
32.
BackgroundNeisseria meningitidis is one of the most important causes of meningitis and pathogens-associated deaths in developing and developed countries. Effective anti-microbial agents are pivotal to treat and control N. meningitidis infections. The aim of the present study was to systematically review published studies on the antibiotic resistance of N. meningitidis in the last 20 years (2000–2020) in the world.MethodsPublished researches were identified through a literature search using reputable databases including PubMed, Scopus, and Web of Science. Finally, 24 studies were included for a random-effects model meta-analysis.ResultsThe overall resistance to most commonly used antibiotics such as ceftriaxone, cefotaxime, ciprofloxacin and rifampin was low, ranging from 1 to 3.4%. However, non-sensitivity to penicillin, as the first-line antibiotic against N. meningitidis, was higher (27.2%). Altogether, the resistance to the first-line antibiotics (except penicillin) is still low indicating these drugs are effective against meningococcal meningitis. We also found a significant gap between MIC and disk diffusion for evaluating resistance to antibiotics in which disk diffusion overestimate the resistance rate.ConclusionsTo properly management and prevent the spread of N. miningitidis isolates resistant antibiotics, it is necessary to monitor the pattern of antibiotic susceptibility regionally and globally using the MIC methods.  相似文献   
33.
Background and Aim: Furazolidone‐based regimens for the eradication of Helicobacter pylori are low cost and effective although less tolerable. Our aim was to compare the efficacy and compliance of 1‐week furazolidone‐based quadruple therapy (furazolidone, amoxicillin, bismuth subcitrate, omeprazole; FABO) with 2‐week quadruple therapy using the same drugs. Methods: One hundred and fifty‐six consecutive patients with H. pylori related diseases were enrolled in our study. The patients were randomized into two groups of FABO1 and FABO2 groups receiving, 1 or 2 weeks' quadruple H. pylori eradication therapies, respectively, as follows: furazolidone (200 mg twice daily), amoxicillin (1 g twice daily), bismuth (240 mg twice daily) and omeprazole (20 mg twice daily). The χ2 test was used to compare the efficacy of the therapies. Results: The per‐protocol eradication rate in FABO1 and FABO2 groups were 56/66 (84.8%) and 57/69 (82.6%), respectively. The intention‐to‐treat eradication rate was 56/78 (71.8%) in FABO1 group and 57/78 (73.1%) in FABO2 group. There was not any significant statistical difference between two groups. A significant decrease in compliance in FABO2 group was seen. Conclusion: This is an encouraging report showing a therapy with possible success in decreasing the duration of H. pylori infection as well as reaching the eradication rate of 80%.  相似文献   
34.
Understanding neuroectoderm formation and its subsequent diversification to functional neural subtypes remains elusive. We have shown here for the first time that embryonic stem cells (ESCs) can differentiate into neurons and motor neurons (MNs) by using a coculture embryonic notochord model in vitro. Mouse ESCs were induced to form neural precursors via timed exposure to retinoic acid (RA) using the 4-/4+ RA protocol. These cells were then cocultured with alginate bead-encapsulated notochords isolated from Hamburger and Hamilton stage 6-10 chick embryos. The use of notochord alone was not able to induce neural differentiation from ESCs, and, therefore, notochord does not possess neural inducing activity. Hence, the most successful neuronal cells and MN differentiation was only observed following the coculture of RA-pretreated ESCs with notochord. This resulted in a significantly greater number of cells expressing microtubule-associated protein-2 (MAP2), HB9, choline acetyltransferase (ChAT) and MN-specific genes. While further characterization of these differentiated cells will be essential before transplantation studies commence, these data illustrate the effectiveness of embryonic notochord coculture in providing valuable molecular cues for directed differentiation of ESCs toward an MN lineage.  相似文献   
35.
36.
Over the past few decades, microwave processing and its high potential capabilities have attracted food scientists. Application of microwave for microencapsulation is an innovative and new method in which the shell, due to having different dielectric constant, can fuse and cover core. In this research, the citric acid powder at various size ranges was microencapsulated by casein and inulin, using a domestic microwave oven. Then, for sensory evaluation purposes, they along with uncoated citric acid and commercial microcapsules were incorporated in chewing gum formulation. The qualitative and quantitative evaluations revealed the potential capability of this technique at micronized scales. Moreover, findings on some sensory characteristics showed practical and efficient applicability of inulin-coated microcapsules in chewing gum where its sensory scores were competitive and even much better than commercial ones. In addition, these observations elucidate a new approach for producing functional, nutritional and dietetic chewing gums.  相似文献   
37.

Ethnopharmacological relevance

Medicinal plants are an important element of medical system. These resources are usually regarded as part of cultural traditional knowledge. We present for the first time the results of an ethnobotanical survey in Kohghiluyeh va Boyer Ahmad province of Iran, conducted between 2008 and 2010. This information could be the basis of an evidence based investigation to discover new drugs.

Materials and methods

Ethnobotanical data were analyzed by use-reports in addition important indices like relative frequency of citation (RFC) and cultural importance index (CI) were calculated. Totally 23 informants were interviewed.

Results

Our study reports 138 traditionally used plant species, belonging to 52 plant families from this province. Asteraceae and Lamiaceae are the dominant locally used families. The highest number of species and application were reported for digestive system disorder, metabolic disorder and respiratory system, respectively. The part of the plant most frequently used was the aerial part (31.9%), leaves (14.8%) and fruits (11.7%). The plants are used both for medicinal and non-medicinal purposes. Daphne mucronata Royle. and Teucrium polium L. have the largest value of relative frequency of citation and cultural importance index, respectively.

Conclusion

Kohghiluyeh va Boyer Ahmad has good ethnobotanical potential for medicinal plants. This study is the first contribution to the ethnobotany of this region. We have gathered from this province some considerable knowledge about local medicinal plants for treating common health problem that is ready to be further investigated in the laboratory.  相似文献   
38.

Aim

Metabolically Healthy Obese (MHO) is called to obese people that their insulin sensitivity, lipid profiles and inflammatory profiles are favorable, and there are no signs of hypertension and cardio-metabolic diseases. The metabolically unhealthy obese (MUHO) is the opposite. A Body Shape Index (ABSI) is a marker to identifying abdominal obesity that is derived from weight, height and waist circumference (WC). Several studies have reported ABSI is associated with diabetes, metabolic syndrome, hypertension and higher mortality rate.

Materials and methods

A total of 305 overweight and obese women were included in the current comparative cross-sectional study. Body composition was measured using body composition analyzer. Blood samples were obtained. The usual food intake of evaluated through the use of a semi-quantitative food frequency questionnaire.

Results

The results of this study revealed that there is a significant relationship between ABSI and MHO and MUHO (p?=?0.04) and area under the ROC curve was 0.60. Also there is a significant relationship between BMI, fat mass index (FMI), free fat mass index (FFMI), neck circumference (NC), WC, fat mass (FM) and metabolic healthy status (MHS). The largest area under the ROC curve belonged to NC, WC, FM and BMI (0.66).

Conclusion

The findings of this study suggest that there is a significant relationship between ABSI, BMI, FMI, FFMI, NC, WC, FM and MHS. The largest area under the ROC curve was related to the NC, WC, FM and BMI not ABSI, that means NC, WC, FM and BMI have maximum sensitivity and specificity.  相似文献   
39.
Modification of various properties of graphene oxide (GO) films on SiO2/Si substrate under KrF laser radiation was extensively studied. X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and the electrical resistance measurements were employed to correlate the effects of laser irradiation on structural, chemical and electrical properties of GO films under different laser fluences. Raman spectroscopy shows reduced graphene oxide patterns with increased I2D/IG ratios in irradiated samples. X-ray photoelectron spectroscopy shows a high ratio of carbon to oxygen atoms in the reduced graphene oxide (rGO) films compared to the pristine GO films. X-ray diffraction patterns display a significant drop in the diffraction peak intensity after laser irradiation. Finally, the electrical resistance of irradiated GO films reduced by about four orders of magnitudes compared to the unirradiated GO films. Simultaneously, reduction and patterning of GO films display promising fabrication technique that can be useful for many graphene-based devices.

Modification of various properties of graphene oxide (GO) films on SiO2/Si substrate under KrF laser radiation was extensively studied.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号