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   486篇
  免费   42篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   9篇
妇产科学   16篇
基础医学   45篇
口腔科学   17篇
临床医学   58篇
内科学   93篇
皮肤病学   20篇
神经病学   34篇
特种医学   7篇
外科学   79篇
综合类   6篇
一般理论   1篇
预防医学   44篇
眼科学   28篇
药学   17篇
中国医学   1篇
肿瘤学   53篇
  2023年   6篇
  2022年   7篇
  2021年   16篇
  2020年   12篇
  2019年   27篇
  2018年   18篇
  2017年   13篇
  2016年   18篇
  2015年   27篇
  2014年   28篇
  2013年   30篇
  2012年   49篇
  2011年   33篇
  2010年   25篇
  2009年   23篇
  2008年   28篇
  2007年   32篇
  2006年   23篇
  2005年   15篇
  2004年   13篇
  2003年   9篇
  2002年   10篇
  2001年   3篇
  1999年   2篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1993年   2篇
  1992年   4篇
  1990年   2篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1986年   5篇
  1985年   2篇
  1984年   4篇
  1983年   3篇
  1982年   1篇
  1980年   3篇
  1979年   4篇
  1978年   2篇
  1977年   3篇
  1976年   3篇
  1975年   3篇
  1974年   4篇
  1973年   1篇
  1972年   1篇
  1971年   3篇
  1970年   2篇
  1967年   1篇
排序方式: 共有529条查询结果,搜索用时 31 毫秒
1.
We investigated parameters of nutrition, metabolism, and organ function after 4 wk of total parenteral nutrition (TPN) in baboons receiving either dipeptides or amino acids as the nitrogen source. The two groups showed no significant difference with respect to gain in body weight, nitrogen balance, plasma and muscle concentrations of amino acids, plasma concentrations of proteins, and leucine incorporation into muscle protein. All dipeptides were efficiently utilized as evidenced by trace concentrations of dipeptides in plasma and urine; they produced no deleterious effect on the function of liver, kidney, or immune system. Development of infection in several baboons increased urinary excretion of urea nitrogen but had no effect on urinary excretion of dipeptides and amino acids with the single exception of taurine, which was greatly increased. In conclusion, the data show long-term efficacy and safety of the dipeptide mixture as the sole nitrogen source for TPN.  相似文献   
2.
The aim of this study was to determine the relationships between bone mineral density (BMD) and blood pressure in 214 men, age 20–76. BMD measurements were done by dual X‐ray absorptiometry using a Lunar DPXMD densitometer at the lumbar spine (L2–L4) and different femoral regions. Systolic (SBP) and diastolic (DBP) blood pressure were measured using an MPC‐350 sphygmomanometer. Physicians gathered demographic data and participants' dietary intake of calcium were determined by using food frequency questionnaires. After adjusting for age, body mass index, dietary calcium, and exercise history, multiple linear regression models showed that DBP was negatively related to femoral neck BMD (β = ?0.145, P = 0.032) and just shy of significant association with femoral neck BMC (β = ?0.114, P = 0.079). SBP was correlated with femoral neck (r = ?0.171, P = 0.012) and Ward's (r = ?0.186, P = 0.006) BMD but not after adjusting for possible confounders. Further studies are needed to determine whether elevated blood pressure is causally related to the development of low bone mass. Am. J. Hum. Biol. 16:168–171, 2004. © 2004 Wiley‐Liss, Inc.  相似文献   
3.
Hepatocyte activator inhibitor-1 (HAI-1) is a transmembrane serine protease inhibitor that regulates the conversion of latent to active hepatocyte growth factor (HGF). Studies supporting a role for the HGF pathway in prostate carcinogenesis prompted an analysis of HAI-1 expression in the prostate. Here we analyze the regulation of HAI-1 expression by androgen, oncogenic transformation, and cancer progression. Immunohistochemical analysis revealed that HAI-1 expression was restricted to prostate epithelium, where staining occurred primarily in basal and atrophic luminal epithelial cells. Compared to normal glands, HAI-1 expression was significantly increased in localized prostate cancer and was present in most prostate cancer metastases. HAI-1 protein expression levels were sensitive to androgen in normal epithelium but not in cancer. Although androgen did not increase HAI-1 protein expression levels in LNCaP cells, it decreased HAI-1 surface expression, consistent with previous data from our group (Martin DB, Gifford DR, Wright ME, Keller A, Yi E, Goodlett DR, Aebersold R, Nelson PS: Quantitative proteomic analysis of proteins released by neoplastic prostate epithelium. Cancer Res 2004, 64:347-355). HAI-1 overexpression in cancer was predictive of prostate-specific antigen recurrence (relative risk, 1.24). These results suggest that HAI-1 regulates the HGF Met axis on prostate epithelial cells and influences HGF mediated tumor invasion and metastasis.  相似文献   
4.
5.
6.
7.
8.
Achieving adequate pulpal anesthesia in mandibular teeth is always a challenge. Supplementary injections and using drugs in combination are some methods implemented to overcome this hurdle. In this randomized clinical trial, use of meperidine in conjunction with lidocaine in intraligamentary injection did not exhibit significant improvement in anesthesia.Key Words: Periodontal ligament, Meperidine, Irreversible pulpitis, Dental anesthesiaThe failure rate of the inferior alveolar nerve block (IANB) in some experimental studies has been reported up to 75%.14 This lack of success has even increased to a maximum of 81% in some recent studies.57 To overcome this shortcoming, dental clinicians have actively sought measures to improve the patients'' anesthesia during different dental procedures. Apart from the anatomical variations mentioned in the applied anatomy of injections,8 several authors have attempted to modify the anesthetic technique,912 and others have compared different anesthetic agents13 or their concentrations14 to improve their efficacy.Activating the opioid receptors peripherally in inflammatory conditions has become a new trend in research to manage postoperative pain.15 Synergy between local anesthetics and opioids has become an interesting field of research recently.16 Opioids are frequently added to local anesthetics in a variety of surgical procedures, eg, intrathecal application for minor surgery.17 Meperidine or its derivatives, eg, pethidine (meperidine chloride) or norpethidine (Pethidine Intermediate B) are agonists of μ-opioid receptors, which block the pathway of pain signals to the trigeminal nucleus. They also activate peripheral opioid receptors and block sodium channels.1722 Despite controversy regarding the use of meperidine as an anesthetic,22 recent studies have demonstrated its benefits over prilocaine in arthroscopy with local anesthesia,16 nasal packing removal,23 etc.However, only a few studies have investigated the dental anesthetic efficacy of such combinations.24,25 The effect of the addition of meperidine to lidocaine in IANB for pain management in normal teeth24 and also in teeth with irreversible pulpitis25 has been studied. The aim of our study was to compare the efficacy of local anesthetics with and without meperidine for intraligamentary supplemental injection for teeth with irreversible pulpitis. Our null hypothesis stated that the addition of meperidine to standard lidocaine with epinephrine does not improve the efficacy of supplemental intraligamentary anesthesia in teeth with symptomatic irreversible pulpitis. The specific objectives were to randomly allocate volunteers with complete soft tissue anesthesia following an IANB, yet having positive pulp response, into 2 groups, and then compare the efficacy of lidocaine with epinephrine plus meperidine with that of lidocaine with epinephrine plus an equal volume of sterile water for supplemental periodontal ligament anesthesia.  相似文献   
9.
10.

Background:

Childhood traumatic brain injury (TBI) has high rate of mortality and morbidity worldwide. There are dearths of reports from developing countries with large paediatric population on trauma; neurosurgery trauma of nonaccidental origin is not an exemption. This study analysed menace of non-accidental TBI in the paediatric population from our center.

Materials and Methods:

This is a single unit, retrospective study of the epidemiology of non-accidental TBI in children starting from September, 2008 to March, 2014. The management outcomes of the epidemiology of the non-accidental TBI were analysed.

Results:

Total of 109 children age range from 0 (intra-natal) to 16 years with a mean of 5.8 ± 4.6 years (median, 5 years) were enrolled into the study. 34 (31.2%) were domestic violence, 26 (23.9%) street assaults, 16 (14.7%) were due to animal assaults and mishaps, 17 (15.6%) fall from heights. Seven (6.4%) cases of collapsed buildings were also seen during the period. Four (3.7%) industrial accidents and two (1.8%) were self-inflicted injuries. There were also three (2.8%) cases of iatrogenic TBI out of which two infants (1.8%) sustained TBI from cesarean section procedure while one patient (0.9%) under general anaesthesia felt from the operation bed resulting to severe TBI.

Conclusion:

Child abuse, unprotected child labour, parental/care-givers negligence are the main cause of nonaccidental TBI. Human right activists and government agents should be incorporated in curtailing the menace.  相似文献   
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