全文获取类型
收费全文 | 226168篇 |
免费 | 9606篇 |
国内免费 | 578篇 |
专业分类
耳鼻咽喉 | 2972篇 |
儿科学 | 6816篇 |
妇产科学 | 5664篇 |
基础医学 | 32400篇 |
口腔科学 | 7277篇 |
临床医学 | 14258篇 |
内科学 | 50624篇 |
皮肤病学 | 6910篇 |
神经病学 | 18443篇 |
特种医学 | 5666篇 |
外国民族医学 | 30篇 |
外科学 | 27069篇 |
综合类 | 1133篇 |
一般理论 | 38篇 |
预防医学 | 24513篇 |
眼科学 | 5310篇 |
药学 | 16874篇 |
中国医学 | 855篇 |
肿瘤学 | 9500篇 |
出版年
2023年 | 1152篇 |
2022年 | 1686篇 |
2021年 | 4288篇 |
2020年 | 2365篇 |
2019年 | 4364篇 |
2018年 | 6337篇 |
2017年 | 4044篇 |
2016年 | 4164篇 |
2015年 | 4553篇 |
2014年 | 5745篇 |
2013年 | 8461篇 |
2012年 | 13406篇 |
2011年 | 13984篇 |
2010年 | 7406篇 |
2009年 | 6112篇 |
2008年 | 11558篇 |
2007年 | 12222篇 |
2006年 | 11817篇 |
2005年 | 11516篇 |
2004年 | 10637篇 |
2003年 | 9925篇 |
2002年 | 9544篇 |
2001年 | 6833篇 |
2000年 | 7379篇 |
1999年 | 5928篇 |
1998年 | 1495篇 |
1997年 | 1073篇 |
1992年 | 3103篇 |
1991年 | 2895篇 |
1990年 | 2843篇 |
1989年 | 2475篇 |
1988年 | 2293篇 |
1987年 | 2143篇 |
1986年 | 2156篇 |
1985年 | 2008篇 |
1984年 | 1472篇 |
1983年 | 1281篇 |
1979年 | 1587篇 |
1978年 | 1067篇 |
1977年 | 1004篇 |
1975年 | 1151篇 |
1974年 | 1426篇 |
1973年 | 1459篇 |
1972年 | 1374篇 |
1971年 | 1322篇 |
1970年 | 1264篇 |
1969年 | 1324篇 |
1968年 | 1306篇 |
1967年 | 1173篇 |
1966年 | 1068篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
The present study demonstrates the effects of the antidepressant, amitriptyline, and the acetylcholine antagonist, atropine, on the stimulation-induced rise in cytosolic, free Ca2+ (Cai2+). The changes in Cai2+ of collagenase-isolated rat parotid acini were measured by means of the Ca2(+)-sensitive dye, fura-2. It was found that stimulation by carbachol resulted in a maximal increase of 582 +/- 34 nM (mean +/- S.E.) in Cai2+ with a ks of 5.8 +/- 1.3 microM. Adrenaline caused a rise of 380 +/- 22 nM in Cai2+ with a ks of 0.5 +/- 0.2 microM. Amitriptyline and atropine were found to inhibit the carbachol-induced rise in Cai2+ with dissociation constants (kI) of 105 and 1.25 nM, respectively, in the absence of agonist. The adrenergic-induced rise in Cai2+ was inhibited by amitriptyline with a kI of 45 nM. Amitriptyline was found to inhibit both receptor classes by a competitive or mixed type of inhibition. Similarly, atropine exerted the same type of inhibition on the acetylcholine receptor. Amitriptyline and atropine were found to be mutually exclusive for competing for substrate binding on the receptor. These findings are consistent with a common binding site for amitriptyline and atropine on the acetylcholine receptor, possibly in close proximity with, but different from the substrate binding site. The stimulation-induced cell shrinkage evoked by the loss of electrolytes and water from the acini was measured by a 90 degree light scattering signal. It was found that this method makes possible the detection of autonomic side-effects of antidepressants on acini suspended in protein-containing media. 相似文献
103.
B. Hagander J. Holm† N.-G. Asp† S. Efendi‡ I. Lundquist§ P. Nilsson-Ehle B. Scherstén 《Journal of human nutrition and dietetics》1988,1(4):239-246
Test meals with 10.9 g dietary fibre from sugar beet and corresponding control meals were given to eight healthy subjects, aged 67 ± 9 years. The postprandial glucose, triglyceride, hormone and glycerol responses were monitored during 3 hours. After the beet fibre meal the insulin and C-peptide areas were reduced by 28 ( P < 0.01) and 22% ( P > 0.025), respectively, and the somatostatin levels increased by approximately 30% ( P > 0.05). Further, the maximum relative postprandial reduction of plasma glycerol levels was less evident after the fibre-rich meal than after the control meal (36 ± 4% v. 46 ± 4%, P < 0.05). There was no apparent difference in the overall glycaemic response between the meals. The triglyceride levels were similar after both test meals.
Suspension of beet fibre bread given to rats by oro-gastric intubation induced lower blood glucose response than a control bread at 15 and 30 min ( P < 0.001), respectively, but a similar insulin response.
The results suggest an effect of beet fibre on the rate of carbohydrate absorption, expressed as a lower insulin response in the healthy volunteers and a reduced glucose response in the rat.
The mechanism behind this effect in healthy subjects could possibly be mediated by an increased somatostatin response. 相似文献
Suspension of beet fibre bread given to rats by oro-gastric intubation induced lower blood glucose response than a control bread at 15 and 30 min ( P < 0.001), respectively, but a similar insulin response.
The results suggest an effect of beet fibre on the rate of carbohydrate absorption, expressed as a lower insulin response in the healthy volunteers and a reduced glucose response in the rat.
The mechanism behind this effect in healthy subjects could possibly be mediated by an increased somatostatin response. 相似文献
104.
105.
Stanislw Ryng Zdzislw Machn Zbigniew Wieczorek Michal Zimecki Tadeusz Glowiak 《Archiv der Pharmazie》1997,330(11):319-326
A series of 5-aminomethinimino-3-methyl-4-isoxazolecarboxylic acid phenylamides 4 has been prepared by condensation of 5-amino-3-methyl-4-isoxazolecarboxylic acid phenylamides 1 with trichloroacetic aldehyde. Alcoholysis of trichloro derivatives 2 gave 5-alkoxymethine derivatives 3 which, on reaction with an appropriate amine, formed the corresponding compounds 4 . The compounds obtained were evaluated for their immunological activity. The properties of three compounds, described in this report, permitted inhibition of the immune response in all possible ways: diminishing both types of immune response ( 4d ), humoral immune response ( 4a ), or cellular immune response ( 4c ). Preparation 4d is comparable in its effectiveness to CsA, so it may be potentially used as an agent for prolongation of the function of transplanted organs. Two other compounds may potentially be used in cases where only one type the immune response is required for combating pathogen invasion. 相似文献
106.
Prospective study of antigenemia,plasma viremia and lymphocytic viremia in HIV-infected hemophiliacs
S. Melón Garcia M. de Oña Navarro C. Rodriguez Pinto M. Fernández Urgellés A. Martinez Gutierrez P. de la Iglesia F. J. Mendez García 《European journal of clinical microbiology & infectious diseases》1995,14(5):400-405
A total of 186 blood samples from 24 HIV-1 seropositive hemophiliac patients, monitored every four months for 29 months, were investigated for the presence of viral antigen in plasma. In addition, peripheral blood mononuclear cells (PBMC) were cultured for HIV-1, using normal PBMC as a target for replication. Antigenemia was detected in 51 % of the patients and from PBMC in 87.5 % of the patients. The incidence of HIV isolation in asymptomatic patients (42.8 %) was similar to that found in symptomatic patients (51.4 %). Patients with opportunistic infections had a higher incidence of lymphocytic viremia (p<0.05). Plasma viremia was closely associated (p<0.05) with low CD4+ counts and infection progression. The persistence of antigenemia was also a marker of a poor clinical course. In treated patients, plasma viremia was the marker that better correlated with the clinical course, and it did not appear during the first nine months of therapy. Zidovudine doses of >500 mg/day significantly lowered the appearance of antigenemia and lymphocytic viremia (p<0.05). 相似文献
107.
108.
V N Koshelev Iu V Chalyk D V Gol'dshte?n 《Klinichna khirurhiia / Ministerstvo okhorony zdorov'ia Ukra?ny, Naukove tovarystvo khirurhiv Ukra?ny》1990,(9):24-25
A comparison of the results of 169 cholecystectomies with the use of a laser scalpel and 160--conventional methods was carried out. The CO2-laser was used for exposure of the gallbladder and coagulation of tissue of the liver in the region of its bed. Hemo- and cholestasis in all the cases was reliable, and due to this fact in 27% of the patients, the subhepatic recess was not drained. The incidence of complications after the elective cholecystectomy reduced by 11%, after the emergency one--by 9%, the lethality reduced considerably. 相似文献
109.
A series of N-(phosphonoacetyl)-dipeptide derivatives was synthesized for pharmacological testing as antihypertensive compounds. Several of these compounds demonstrated a moderate antihypertensive effect in Wistar spontaneous hypertensive rats (SHR) with p.o. dosing. ACE inhibition by the compounds was studied using ACE from rat plasma and lung. Inhibitors containing esterified C-termini are pro-drugs and showed activity only for plasma ACE. 相似文献
110.
P Bálványossy K Dévay L Alf?ldi 《Magyar traumatológia, orthopaedia és helyreállító sebészet》1990,33(2):140-141
Authors describe a case of isolated posttraumatic neuropraxy of the musculocutaneous nerve. With the presentation of this very rare case attention is called, based on literary date, to the fact that the above injury can be mixed with the distal tendon rupture of the biceps. 相似文献