全文获取类型
收费全文 | 533505篇 |
免费 | 35595篇 |
国内免费 | 628篇 |
专业分类
耳鼻咽喉 | 7087篇 |
儿科学 | 17488篇 |
妇产科学 | 13892篇 |
基础医学 | 87928篇 |
口腔科学 | 14993篇 |
临床医学 | 46666篇 |
内科学 | 96889篇 |
皮肤病学 | 12465篇 |
神经病学 | 37667篇 |
特种医学 | 19123篇 |
外国民族医学 | 65篇 |
外科学 | 79632篇 |
综合类 | 8867篇 |
一般理论 | 142篇 |
预防医学 | 41435篇 |
眼科学 | 12484篇 |
药学 | 42179篇 |
中国医学 | 1096篇 |
肿瘤学 | 29630篇 |
出版年
2018年 | 5274篇 |
2015年 | 4806篇 |
2014年 | 6461篇 |
2013年 | 10130篇 |
2012年 | 13717篇 |
2011年 | 15166篇 |
2010年 | 8790篇 |
2009年 | 8230篇 |
2008年 | 14458篇 |
2007年 | 15540篇 |
2006年 | 15839篇 |
2005年 | 15228篇 |
2004年 | 14871篇 |
2003年 | 14187篇 |
2002年 | 14053篇 |
2001年 | 24794篇 |
2000年 | 25809篇 |
1999年 | 21188篇 |
1998年 | 5695篇 |
1997年 | 4939篇 |
1996年 | 5295篇 |
1995年 | 4854篇 |
1994年 | 4528篇 |
1993年 | 4316篇 |
1992年 | 16250篇 |
1991年 | 16752篇 |
1990年 | 16877篇 |
1989年 | 16187篇 |
1988年 | 14950篇 |
1987年 | 14810篇 |
1986年 | 13975篇 |
1985年 | 13325篇 |
1984年 | 9908篇 |
1983年 | 8471篇 |
1982年 | 4736篇 |
1981年 | 4402篇 |
1979年 | 9674篇 |
1978年 | 7045篇 |
1977年 | 5925篇 |
1976年 | 5748篇 |
1975年 | 6551篇 |
1974年 | 7808篇 |
1973年 | 7303篇 |
1972年 | 7134篇 |
1971年 | 6829篇 |
1970年 | 6299篇 |
1969年 | 6011篇 |
1968年 | 5662篇 |
1967年 | 5113篇 |
1966年 | 4550篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Hale Sayan V Haktan Ozacmak Aysel Guven R Gulhan Aktas I Diler Ozacmak 《Journal of investigative surgery》2006,19(3):163-173
Erythropoietin exerts hematopoietic effects by stimulating proliferation of early erythroid precursors. Nonhematopoietic effects of erythropoietin have also been shown. It may act as a new angiogenic factor in wound healing. This study aimed to investigate the effect of systemic administration of recombinant human erythropoietin on wound healing in mice. Dorsal incisional wounds were performed in mice, which were then divided into two groups; a group treated for 7 days with recombinant human erythropoietin, and a control group. Sacrificing animals on day 7, the wound tissues were collected for analysis of wound breaking strength, malondialdehyde, a marker of lipid peroxidation, hydroxyproline, an index of reparative collagen deposition, reduced glutathione levels, and for histological evaluation. The immunohistochemical determination of vascular endothelial growth factor (VEGF) which is believed to be the most prevalent angiogenic factor throughout the skin repair process, was also studied. The treatment significantly increased wound breaking strength by decreasing malondialdehyde and increasing hydroxyproline levels on day 7 after wounding. No statistically meaningful change was observed in reduced glutathione content. VEGF was immunostained significantly more on wound tissue of treated animals compared to the control group. Recombinant human erythropoietin treatment may be effective in wound healing due to inhibition of lipid peroxidation, deposition of collagen, and VEGF expression in wound area. 相似文献
32.
N. N. Polygalova A. G. Mikhailovskii E. S. Limanskii B. Ya. Syropyatov M. I. Vakhrin 《Pharmaceutical Chemistry Journal》2006,40(3):132-134
A series of 1-alkyl-3,4-dihydroisoquinolines and the related 4-alkyl-1,2-dihydro-benzo[f]isoquinolines was synthesized using
reactions of dialkylbenzylcarbinols and their naphthyl analogs with alkylcyanides. Experiments showed that 1-alkyl-6,7-dimethoxy-3,4-dihydroisoquinolines
typically produce a hypotensive action, while the benzo-annelated structures usually exhibit a hypertensive effects. The most
active compound decreases the arterial pressure in cats by 52 Torr and the effect lasts for about 4 hours.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 3, pp. 15–17, March, 2006. 相似文献
33.
34.
Timothy C. Evans MD PhD ; Keren H. Wick PhD ; Douglas M. Brock PhD ; Douglas C. Schaad PhD ; Ruth Ballweg MPA PA-C 《The Journal of rural health》2006,22(3):212-219
CONTEXT: The physician assistant profession has been moving toward requiring master's degrees for new practitioners, but some argue this could change the face of the discipline. PURPOSE: To see if there is an association between physician assistants' academic degrees and practice in primary care, in rural areas, and with the medically underserved. METHODS: Surveys were sent to 880 graduates of the first 32 University of Washington physician assistant classes through 2000. Respondents noted their academic degree at program entry and the highest degree attained at any time up to the time of survey. Relationships between practice characteristics and academic degree levels were tested by unadjusted odds ratios and logistic regression after controlling for year of graduation and sex. RESULTS: Of the 478 respondents, 54% worked in primary care, about 30% practiced in nonmetropolitan communities, and 42% reported providing care for the medically underserved. Respondents with no degree (33% of total at entry, 24% at survey) were significantly more likely than degree holders to work in primary care and nonmetropolitan areas. Respondents with no degree at program entry were significantly more likely, and those with no degree at the time of the survey were marginally more likely, to self-report work with the medically underserved. CONCLUSION: Respondents with no academic degree are significantly more likely to demonstrate a commitment to primary, rural, and underserved health care. These findings may inform the national debate about the impact of required advanced degrees on the practice patterns of nonphysician providers. 相似文献
35.
36.
AIMS: To examine the effects of agents that alter potassium adenosine triphosphate (KATP) channel activity in beta-cells on cognitive function and counterregulatory hormone responses during acute hypoglycaemia, given the physiological similarities between the pancreatic beta-cell and the hypothalamic glucose-sensitive neurones (GSN) and the widespread distribution of sulphonylurea receptors in neuronal cells throughout the brain. METHODS: Ten healthy males were studied on four occasions and in random order underwent three stepped hypoglycaemic (plasma glucose aims: 3.4, 2.8, 2.4 mmol/l) and one euglycaemic (plasma glucose aim: 5 mmol/l) insulin clamps. Prior to each hypoglycaemic study, volunteers received either 10 mg glibenclamide, or 5 mg/kg diazoxide or placebo orally. Cognitive function, symptom scores and counterregulatory hormone responses were measured at each glycaemic level. RESULTS: There was no statistically significant effect of either drug on the symptoms generated or the counterregulatory hormonal response during hypoglycaemia. However, cognitive function was better preserved during hypoglycaemia in the glibenclamide-treated arm, particularly four-choice reaction time which deteriorated at a plasma glucose 2.5 mmol/l compared with 3.0 mmol/l with diazoxide (P = 0.015) and 2.9 mmol/l with placebo (P = 0.114). CONCLUSIONS: Single doses of pharmacological agents which alter membrane KATP channel activity do not affect the counterregulatory response to hypoglycaemia but may modify cognitive function during cerebral glucopenia. The unexpected effects of glibenclamide on cortical function suggest a novel action of sulphonylureas that warrants further investigation. 相似文献
37.
P F Plouin D L Clement H Boccalon J Dormandy I Durand-Zaleski G Fowkes L Norgren T Brown 《International angiology》2003,22(4):333-339
Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases. 相似文献
38.
S. V. Terent’eva E. N. Komarova T. N. Sapozhnikova A. T. Teplyakov E. A. Ivanovskaya T. I. Andreeva 《Pharmaceutical Chemistry Journal》2006,40(12):694-696
A rapid procedure for determining angiotensin II in the blood by inverse voltammetry using a TA-2 device (Tekhnoanalit Company,
Tomsk) with a graphite electrode has been developed. The results of analyses using the proposed technique agree with the clinical
data. The rapid analytical procedure favors optimization of cardiotropic drug therapy.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 12, pp. 54–56, December, 2006. 相似文献
39.
40.
OBJECTIVE: To compare infants' discomfort, nursing-time and caregiver preference, and assess the clinical efficiency (as a secondary outcome) of hood versus facemask nebulization in infants with evolving bronchopulmonary dysplasia (BPD) in the neonatal intensive care unit. STUDY DESIGN: A prospective, open, randomized, controlled crossover clinical trial. In total, 10 infants with BPD who were on inhaled beta-agonist bronchodilators and corticosteroids were randomly assigned to receive their nebulized treatments either by a facemask, or by a hood for 2-3 days, and then crossover to receive the same treatments with the other technique for another 2-3 days. Infants' discomfort, nursing-time, caregiver preference and clinical efficiency were compared. RESULTS: At baseline there was no significant clinical difference between the groups. Nurse-time required for administering the hood nebulization (mean+/-s.e.m.: 1.9+/-0.1 min) was significantly shorter than the time for mask nebulization (12.0+/-0.6 min, P<0.0001). Infants' discomfort score was significantly lower (0.1+/-0.04) for hood versus mask nebulization (2.5+/-0.2, P<0.0001). Nurses and parents unequivocally preferred the hood treatment. During both mask and hood nebulization therapies (2-3 days) clinical efficiency was comparable. While both methods caused an immediate (20 min post) clinical improvement, the immediate respiratory assessment change score was significantly greater for the hood versus the mask nebulization (0.62+/-0.27 versus 0.13+/-0.14, P<0.05). CONCLUSIONS: Nebulization of aerosolized medications in infants with evolving BPD by hood was less time-consuming for caregivers and was much better tolerated by the infants while being at least as effective as the conventional facemask nebulization. 相似文献