全文获取类型
收费全文 | 17963篇 |
免费 | 1203篇 |
国内免费 | 56篇 |
学科分类
医药卫生 | 19222篇 |
出版年
2023年 | 104篇 |
2022年 | 124篇 |
2021年 | 435篇 |
2020年 | 244篇 |
2019年 | 458篇 |
2018年 | 528篇 |
2017年 | 343篇 |
2016年 | 388篇 |
2015年 | 473篇 |
2014年 | 623篇 |
2013年 | 934篇 |
2012年 | 1289篇 |
2011年 | 1377篇 |
2010年 | 778篇 |
2009年 | 635篇 |
2008年 | 1214篇 |
2007年 | 1218篇 |
2006年 | 1222篇 |
2005年 | 1212篇 |
2004年 | 1097篇 |
2003年 | 1067篇 |
2002年 | 1023篇 |
2001年 | 226篇 |
2000年 | 203篇 |
1999年 | 207篇 |
1998年 | 177篇 |
1997年 | 161篇 |
1996年 | 153篇 |
1995年 | 133篇 |
1994年 | 74篇 |
1993年 | 100篇 |
1992年 | 94篇 |
1991年 | 101篇 |
1990年 | 92篇 |
1989年 | 69篇 |
1988年 | 78篇 |
1987年 | 58篇 |
1986年 | 51篇 |
1985年 | 51篇 |
1984年 | 60篇 |
1983年 | 45篇 |
1982年 | 48篇 |
1981年 | 46篇 |
1980年 | 34篇 |
1979年 | 22篇 |
1978年 | 23篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1973年 | 18篇 |
1972年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Cynthia Farrell 《Dimensions of critical care nursing》2004,23(6):264-269
Advanced practice nurses within acute care settings are responsible for providing healthcare to a rapidly expanding population of elderly patients. Medical advances have contributed to the longevity of the American population, resulting in an increase in age-related disease that can lead to depression. It is important for acute care nurses to become familiar with the various classes of antidepressant medications and the implications for their use. 相似文献
23.
Branislav Radovancevic Alessandro Golino Bojan Vrtovec Cynthia D Thomas Rajko Radovancevic Peggy Odegaard Charles C van Rossem Sebastiaan J M Gaemers William K Vaughn Frank W Smart O H Frazier 《The Journal of heart and lung transplantation》2005,24(6):703-707
BACKGROUND: Left ventricular assist device (LVAD) support is associated with coagulopathy, bleeding, increased blood transfusion, and increased anti-HLA antibody production. Increased anti-HLA antibody production is associated with early transplant rejection, transplant coronary artery disease (CAD), and decreased post-transplant survival rates. We asked whether bridging to transplantation with an LVAD increases the risk of transplant CAD. METHODS: We reviewed data for all adults (>18 years old) who underwent heart transplantation at our institution between 1988 and 2000. After exclusion of transplant recipients who survived <3 years, we divided the remaining cohort into 2 groups: those bridged to transplantation with LVADs (mean duration of support, 149 +/- 107 days, n = 29) and those in United Network for Organ Sharing Status 1 bridged to transplantation without LVADs (controls, n = 86). We compared groups in terms of disease cause, age, sex, donor age, panel-reactive antibody testing, crossmatching, pre- and post-transplant cholesterol concentrations, diagnosis of diabetes mellitus or treated hypertension, infections, calcium channel blocker use, transplant rejection, ischemic time, cytomegalovirus infection, pre-transplant transfusion, and incidence of transplant CAD (defined as any coronary lesion identified by coronary angiography). We considered p < 0.05 to be significant. RESULTS: The bridged and control groups were similar in all respects except mean ischemic time (217 +/- 58 minutes vs 179 +/- 67 minutes, p = 0.007), post-transplant cholesterol concentration (212 +/- 55 mg/dl vs 171 +/- 66 mg/dl, p = 0.007), and pre-transplant transfusion incidence (100% vs 22%, p < 0.001). The incidence of transplant CAD was similar in both groups during a 3-year follow-up period (28% vs 17%, p = 0.238) and during total follow-up (34% vs 35%, p = 0.969). Multivariate logistic regression analysis identified cholesterol concentration at 1 year after transplantation as a significant predictor of CAD at 3 years after heart transplantation (p = 0.0029, odds ratio = 0.984). CONCLUSIONS: Bridging to transplantation with an LVAD does not increase the risk of transplant CAD. Nevertheless, aggressive prophylactic therapy to minimize potential risk factors for transplant CAD, such as increased cholesterol concentration, is warranted in all transplant recipients. 相似文献
24.
J. M. Bellón N. García-Honduvilla N. Serrano M. Rodríguez G. Pascual J. Buján 《Hernia》2005,9(4):338-343
The component of a composite prosthesis, which makes contact with the visceral peritoneum, can be reabsorbable or non-reabsorbable,
and laminar or reticular. This study was designed to determine whether the composition of this second, barrier component could
improve its behavior at this interface. Abdominal wall defects in rabbits were repaired using a polypropylene prosthesis (PP),
or the composites Sepramesh (PP+h) or Vicryl (PP+v). Fourteen days after surgery, the implants were evaluated by light and
scanning electron microscopy, and immunohistochemistry. Prosthetic areas occupied by adhesions (PP: 71.08±5.09, PP+h: 18.55±4.96,
P+v: 69.69±16.81%), neoperitoneal thickness (PP: 256.17±21.68, PP+h: 83.11±19.63, PP+v:213.72±35.90 μm) and macrophage counts
(PP: 8.73±1.16, PP+h: 27.33±4.13, PP+v: 31.24±3.08%) showed significant differences (P<0.05). The tested biomaterials induced an optimal recipient tissue infiltration. Least adhesion formation was observed on
the PP+h implants. This suggests that the second component, although reabsorbable, should be smooth in structure. 相似文献
25.
26.
Scarlett Lin Gomez Cynthia D O'Malley Antoinette Stroup Sarah J Shema William A Satariano 《BMC cancer》2007,7(1):193
Background
Colorectal cancer, if detected early, has greater than 90% 5-year survival. However, survival has been shown to vary across racial/ethnic groups in the United States, despite the availability of early detection methods. 相似文献27.
Judith L. Marks PhD Elizabeth M. Hill PhD Cynthia S. Pomerleau PhD Sharon A. Mudd PhD Frederic C. Blow PhD 《Journal of substance abuse treatment》1997,14(6):337-527
We compared nicotine dependence and withdrawal in male alcoholic and control ever-smokers, controlling for relevant demographic and clinical variables. Alcoholics were more likely to meet criteria for moderate or severe nicotine dependence and endorse more nicotine dependence symptoms. Symptoms reported more frequently by alcoholics included: (a) using nicotine in larger amounts or over a longer time than intended; (b) continued use despite problems caused or exacerbated by nicotine; (c) marked tolerance; and (d) experiencing characteristic nicotine withdrawal symptoms. Alcoholics also smoked more heavily. Other than “headaches,” and “decreased heart rate,” alcoholics consistently endorsed nicotine withdrawal symptoms at a higher rate. After controlling for demographic and clinical variables and level of nicotine dependence, only “feel depressed” differed significantly between groups. Our research supports previous findings suggesting that nicotine dependence is more severe in those with a history of alcohol dependence. As a result, alcoholics may experience greater discomfort from nicotine withdrawal upon smoking cessation. 相似文献
28.
29.
To define the underlying mechanism of neuromuscular transmission failure induced by anticholinesterases, we simultaneously performed surface recordings of compound muscle action potentials (CMAPs) and intracellular recordings of miniature end-plate potentials (MEPPs), miniature end-plate current (MEPCs), and end-plate potential (EPPs) in rat diaphragms exposed in vitro to 1 × 10?4 to 2 × 10?2 mmol/L neostigmine methylsulfate. At low concentrations of neostigmine, repetitive stimulation of the phrenic nerve resulted in decrement followed by complete recuperation of CMAP amplitudes. This bimodal pattern was associated with maximal end-plate depolarization at the beginning of the stimulation period, increased MEPP amplitudes, and prolonged time constants of MEPC decays. Higher concentrations of neostigmine resulted in a unimodal decline of amplitudes of CMAPs and EPPS, reduced MEPP amplitudes, and a double exponential time course of MEPC decays. These results indicate that low concentrations of anticholinesterases impaired neuromuscular transmission by producing transient depolarization of the end-plate region. Higher concentrations induced desensitization and direct blockade of the end-plate receptor channel, probably in its open conformation. © 1993 John Wiley & Soncs, Inc. 相似文献
30.
C.A. Bond Pharm.D. FCCP Michael E. Pitterle M.S. Cynthia L. Raehl Pharm.D. 《Pharmacotherapy》1994,14(6):712-723
Study Objectives . To determine self-evaluated professional knowledge and competency, functions, demographic information, lifelong learning, degree and training status, practice sites, involvement in pharmacy teaching programs, and salary for recent pharmacy graduates. Design . A survey of recent Bachelor of Science (B.S.) pharmacy graduates of the University of Wisconsin School of Pharmacy. Measurements and Main Results . A total of 371 B.S. pharmacy graduates (55% response rate) provided information. Graduates who had an advanced degree or training (from many programs) after completing their B.S. pharmacy degree, and those who were teaching in pharmacy programs generally had higher self-rated levels of knowledge and competencies. Hospital pharmacists spent less of their work time in dispensing activities (33.82% ± 30.39%) than community pharmacists (61.04% ± 19.97%; t =8.78, df = 288, p<0.001); community pharmacists spent twice as much of their work time counseling and educating patients (16.65% ± 10.47% vs 7.13% ± 7.39%; t = 9.06, df = 288, p<0.001). The amount of time pharmacists spent in dispensing functions had a negative association with knowledge and competencies in the sections on pharmacokinetic and disease process (r=−0.277, p<0.01), patient communications (r=−0.272, p<0.01), and administrative and economic aspects of practice (r=−0.210, p<0.01) for all respondents. Pharmacists reported that they spent 13.78 ± 14.06 hours per month outside work in professional lifelong learning. There was a negative association between the time pharmacists spent dispensing and the time they spent in professional lifelong learning (r=−0.239, p<0.001), and a positive relationship between the time spent in such learning and the time providing information to prescribers and other health care professionals (r=0.214, p<0.001), monitoring patients (r=0.216, p<0.001), and performing primary care activities (r=0.176, p<0.001). Graduates reported a mean yearly salary of $46,879 ± $8183. More hospital pharmacists were involved in teaching (48, 37%) than those practicing in a community setting (19, 12%). Conclusions . Practice site, advanced degree or training, lifelong learning, involvement in teaching programs, and time spent in various professional functions were associated with pharmacists' self-rated knowledge and competencies. (Pharmacotherapy 1994;14(6):712–723) 相似文献