首页 | 官方网站   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   19896篇
  免费   1271篇
  国内免费   35篇
医药卫生   21202篇
  2023年   87篇
  2022年   111篇
  2021年   333篇
  2020年   214篇
  2019年   376篇
  2018年   393篇
  2017年   279篇
  2016年   358篇
  2015年   409篇
  2014年   610篇
  2013年   970篇
  2012年   1397篇
  2011年   1394篇
  2010年   779篇
  2009年   753篇
  2008年   1361篇
  2007年   1342篇
  2006年   1342篇
  2005年   1373篇
  2004年   1312篇
  2003年   1286篇
  2002年   1244篇
  2001年   154篇
  2000年   140篇
  1999年   173篇
  1998年   251篇
  1997年   220篇
  1996年   180篇
  1995年   190篇
  1994年   169篇
  1993年   164篇
  1992年   137篇
  1991年   117篇
  1990年   107篇
  1989年   110篇
  1988年   106篇
  1987年   107篇
  1986年   76篇
  1985年   82篇
  1984年   117篇
  1983年   89篇
  1982年   125篇
  1981年   103篇
  1980年   106篇
  1979年   57篇
  1978年   65篇
  1977年   43篇
  1976年   49篇
  1975年   28篇
  1974年   38篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
OBJECTIVE: To determine the physician gender preferences of children and the consequences of meeting/not meeting children's preferences, both in their liking and feeling comfortable in talking with the pediatrician. METHODS: A convenience sample of 125 parent-child pairs completed surveys when coming for an outpatient visit to a university-sponsored, urban pediatric practice. RESULTS: Both adolescents and preadolescents (especially females) as young as 9 years of age expressed a gender preference for their physician. Meeting those preferences significantly affected how much children both liked and felt comfortable in talking with their physician. In young teen females, gender-preferred physicians are synonymous with gender-congruent physicians; yet although their preference for gender-congruent physicians increased in early adolescence, data indicated that their preference was often not met for several years to come. CONCLUSIONS: Liking and comfort with the pediatrician are not only desirable, but may also influence the doctor-patient relationship and young people's ability to develop health communication skills that they need as adults. These results, if validated, could also lead to a rethinking of parental dominance in the role of physician selection.  相似文献   
85.
This study investigated the effects of neurokinin A (NKA) on cholinergic neural responses in human bronchus. NKA (0.1 nM) did not alter the contractile response to submaximal electrical field stimulation. However, K+ channel blockade with 4-aminopyridine (4-AP) (0.1 mM) potentiated the response to electrical field stimulation (to 182 ± 25% of control, n = 4, P < 0.05) and subsequent addition of NKA in the presence of 4-AP produced further potentiation (to 123 ± 6% of the response to 4-AP n = 4, P < 0.05). Neither 4-AP (0.01 or 0.1 mM) nor NKA in the presence of 4-AP potentiated the actions of exogenous acetylcholine but in these experiments 4-AP itself produced a marked direct contractile response. Thus NKA in the presence of K+ channel blockade potentiates cholinergic neural response in human bronchus and this occurs at a prejunctional site.  相似文献   
86.
87.
Part II of a three-part report of the National Birth Center Study describes care provided to 11,814 women and their newborns during and after labor and delivery until they were transferred or discharged from the birth centers. There were few low birth weight or preterm or postterm births, but more macrosomic babies than among all U.S. births during the same time period. Certified nurse-midwives provided most of the intrapartum care, which is described in the context of medically recommended standards and data that describe care provided to low-risk women giving birth in U.S. hospitals. Birth center care deviated from typical hospital care in several ways. Birth center clients were much less likely to receive central nervous system depressants, anesthesia, continuous electronic fetal monitoring, induction and/or augmentation of labor, intravenous infusions, amniotomies, or episiotomies, and they had relatively few vaginal examinations. They were more likely to eat solid food during labor and to take showers and/or baths Nulliparity was strongly associated with longer first stage labors and longer labor was associated with more frequent use of many kinds of interventions. Infant birth weight, mother's position during delivery, and forceps- or vacuum-assisted deliveries are examined in relation to episiotomies and lacerations and tears.  相似文献   
88.
We have experienced a coagulation factor VIII-deficient patient whose plasma has normal protein S (PS) activity and masses of free PS and its bound form in complex with C4b-binding protein (C4BP). Although the patient's plasma showed a normal ratio of free PS to PS-C4BP complex in the presence of 5 mM EDTA, the plasma gave an abnormally retarding major C4BP peak together with a major PS peak in the crossed immunoelectrophoresis (CIE) in the presence of 2 mM CaCl2. It was revealed that the major peak was formed by a mixture of PS-C4BP complex and free form. The addition of normal human plasma (NHP) to the patient's plasma inhibited the retardation of the major PS-C4BP complex. These suggest that the patient's plasma lacks some component(s) to inhibit Ca2+-dependent association of PS with C4BP.  相似文献   
89.

Purpose  

A new job-specific test for fire fighters, the stair-climb test (FFstair-climb) was evaluated for reproducibility and validity for use in future workers’ health surveillance.  相似文献   
90.
BACKGROUND: We are interested in identifying susceptibility genes that predispose subjects to attempted suicide. METHODS: We conducted a secondary analysis of genome-wide linkage data from 162 bipolar pedigrees that incorporated attempted suicide as a clinical covariate. RESULTS: The strongest covariate-based linkage signal was seen on 2p12 at marker D2S1777. The logarithm of odds (LOD) score at marker D2S1777 rose from 1.56 to 3.82 after inclusion of the suicide covariate, resulting in significant chromosome-wide empirically derived p-values for the overall linkage finding (p = .01) and for the change in LOD score after the inclusion of the covariate (p = .02). CONCLUSIONS: The finding on chromosome 2 replicates results from two previous studies of attempted suicide in pedigrees with alcohol dependence and in pedigrees with recurrent early-onset depression. Combined, these three studies provide compelling evidence for a locus influencing attempted suicide on 2p12.  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-23

京公网安备 11010802026262号