全文获取类型
收费全文 | 451436篇 |
免费 | 67216篇 |
国内免费 | 2824篇 |
专业分类
耳鼻咽喉 | 6600篇 |
儿科学 | 12470篇 |
妇产科学 | 10719篇 |
基础医学 | 68248篇 |
口腔科学 | 16511篇 |
临床医学 | 42250篇 |
内科学 | 100405篇 |
皮肤病学 | 15544篇 |
神经病学 | 40102篇 |
特种医学 | 16348篇 |
外国民族医学 | 83篇 |
外科学 | 74097篇 |
综合类 | 10016篇 |
现状与发展 | 2篇 |
一般理论 | 85篇 |
预防医学 | 21726篇 |
眼科学 | 10736篇 |
药学 | 36526篇 |
1篇 | |
中国医学 | 3196篇 |
肿瘤学 | 35811篇 |
出版年
2021年 | 3865篇 |
2020年 | 6567篇 |
2019年 | 13265篇 |
2018年 | 14055篇 |
2017年 | 14264篇 |
2016年 | 15019篇 |
2015年 | 15365篇 |
2014年 | 16912篇 |
2013年 | 19149篇 |
2012年 | 14028篇 |
2011年 | 14092篇 |
2010年 | 14740篇 |
2009年 | 10964篇 |
2008年 | 11508篇 |
2007年 | 11250篇 |
2006年 | 11201篇 |
2005年 | 10066篇 |
2004年 | 9569篇 |
2003年 | 9314篇 |
2002年 | 9070篇 |
2001年 | 29097篇 |
2000年 | 29548篇 |
1999年 | 23993篇 |
1998年 | 5247篇 |
1997年 | 4309篇 |
1996年 | 3884篇 |
1995年 | 3535篇 |
1994年 | 3169篇 |
1993年 | 2886篇 |
1992年 | 16132篇 |
1991年 | 14883篇 |
1990年 | 14226篇 |
1989年 | 14047篇 |
1988年 | 12674篇 |
1987年 | 12122篇 |
1986年 | 11170篇 |
1985年 | 10405篇 |
1984年 | 6985篇 |
1983年 | 5647篇 |
1982年 | 2768篇 |
1979年 | 5535篇 |
1978年 | 3388篇 |
1977年 | 2998篇 |
1975年 | 2671篇 |
1974年 | 3114篇 |
1973年 | 2893篇 |
1972年 | 2865篇 |
1971年 | 2802篇 |
1970年 | 2541篇 |
1969年 | 2573篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
991.
Y Koyama Y Chinen H Ogura S Shishido I Higa T Hatano M Hayakawa A Osawa M Igarashi 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1990,81(8):1212-1216
Immunological studies were performed in 87 patients with chyluria referred to our clinic from January 1982 to December 1988. White blood cell count in 78 patients was 5210.3 +/- 1440.9/mm3. The fraction and the number of lymphocyte were 18.7 +/- 9.5% and 934.1 +/- 521.6/mm3, respectively: they were lower than normal limit. The percentages of T and B lymphocytes studied in 46 patients were 79.3% +/- 11.2% (normal range: 76-86) and 10.4 +/- 7.9% (normal range: 8-16), respectively: both lymphocytes tended to decrease in percentage. Lymphocyte blast formation stimulated with phytohemagglutinin (PHA) was carried out in 20 patients. The mean of the blast formation was 17410.0 +/- 10275.1 c.p.m. (normal range: 377700-62400), and much lower than normal value. Of 22 patients who had PPD skin test, only 9 (40.9%) were positive. These findings signified that cellular immunity was suppressed in patients with chyluria. On the other hand, the value of immunoglobulin was within normal range (IgG: 1325.3 +/- 475.6 mg/dl, IgA: 242.0 +/- 98.3 mg/dl, IgM 130.4 +/- 95.9 mg/dl). Study on the values of laboratory examinations showed statistically positive correlation between total lymphocyte population and T cell number, and between total lymphocyte population and lymphocyte blast formation. In patients with chyluria, serious sequelae have not been reported. However, care should be taken for possible opportunistic infection and, particularly, malignant tumors because suppression of cellular immunity may be one of the promoting factors of malignant tumors. 相似文献
992.
P Horhant J M N'Guyen Van Tam J P Letoquart M Pompilio Y Haffaf J Chaperon A Mambrini 《Journal de chirurgie》1990,127(8-9):392-395
Sixty nine patients over 75 years old who had a colectomy were retrospectively studied. The carcinoma of the colon represented the main indication for 42 cases (60.9%) and 22 patients (31.9%) were immediately operated. The influence of parameters such as age, sex, visceral defects, emergency, performance of a colostomy or associated intervention, type of colic pathology, was statistically studied. The age (p less than 0.05), emergency (p less than 0.03) and the number of defects greater than or equal to 3 (p less than 0.04) contribute to mortality. The number of defects greater than or equal to 3 (p less than 0.006) contributes to general morbidity. Only complications connected with the operation by itself significantly prolong the duration of hospitalization (p less than 0.02). The authors draw the conclusion that the age by itself is not a contra-indication for operation except in case of associated polyvisceral failure. In addition, it is required to carry out an early detection of colic lesions in elderly subjects in order to contemplate surgery before complications whose prognosis is fearsome (54.5% of death in emergency operation). 相似文献
993.
M. S. Beer J. A. Stanton Y. Bevan A. Heald A. J. Reeve L. J. Street V. G. Matassa R. J. Hargreaves D. N. Middlemiss 《British journal of pharmacology》1993,110(3):1196-1200
1. The 5-hydroxytryptamine (5-HT) receptor binding selectivity profile of a novel, potent 5-HT1D receptor agonist, L-694,247 (2-[5-[3-(4-methylsulphonylamino)benzyl-1,2,4-oxadiazol-5-yl ]- 1H-indole-3-yl]ethylamine) was assessed and compared with that of the 5-HT1-like receptor agonist, sumatriptan. 2. L-694,247 had an affinity (pIC50) of 10.03 at the 5-HT1D binding site and 9.08 at the 5-HT1B binding site (sumatriptan: pIC50 values 8.22 and 5.94 respectively). L-694,247 retained good selectivity with respect to the 5-HT1A binding site (pIC50 = 8.64), the 5-HT1C binding site (6.42), the 5-HT2 binding site (6.50) and the 5-HT1E binding site (5.66). The pIC50 values for sumatriptan at these radioligand binding sites were 6.14, 5.0, < 5.0 and 5.64 respectively. Both L-694,247 and sumatriptan were essentially inactive at the 5-HT3 recognition site. 3. L-694,247, like sumatriptan, displayed a similar efficacy to 5-HT in inhibiting forskolin-stimulated adenylyl cyclase in guinea-pig substantia nigra although L-694,247 (pEC50 = 9.1) was more potent than sumatriptan (6.2) in this 5-HT1D receptor mediated functional response. L-694,247 (pEC50 = 9.4) was also more potent than sumatriptan (6.5) in a second 5-HT1D receptor mediated functional response, the inhibition of K(+)-evoked [3H]-5-HT release from guinea-pig frontal cortex slices.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
994.
Summary The potential for induction of obesity during the preclinical phase of scrapie disease in mice was previously shown to be a function of both the strain of scrapie and the strain of inbred mouse. In the present study, host control of obesity induction by a scrapie strain was examined to determine if the effect were dependent on a single gene or multiple genes. The approach used was assessment of the pattern of weight induction in F1 and F2 crosses of parental inbred mouse strains that did or did not show a weight increase with a specific scrapie strain. Analyses of these data indicated that the induction of obesity was controlled by multiple host genes. In an unrelated observation, there was a correlation between the incubation period of a strain of scrapie in F2 generation mice and their coat color, i.e., the average incubation period of yellow-brown mice was significantly less than those of either black or white mice. 相似文献
995.
S Miyamoto H Kikuchi J Karasawa I Nagata N Yamazoe Y Akiyama 《Journal of neurosurgery》1988,68(4):537-543
Eleven cases of moyamoya disease refractory to indirect non-anastomotic revascularization, including encephalomyosynangiosis in two, encephaloduroarteriosynangiosis in seven, and encephalomyoarteriosynangiosis in two, are described. The patients suffered from recurrent cerebral ischemic symptoms, and further operative intervention, including superficial temporal artery-middle cerebral artery anastomosis and intracranial omental transplantation, was performed. The choice of operative maneuver depended on the availability of scalp arteries and on the nature of the ischemic symptoms. Although indirect non-anastomotic revascularization procedures have the advantage of technical ease and most patients respond to these procedures alone, there are some patients like the 11 presented here who are not cured by such procedures. In such cases, direct anastomotic revascularization is necessary for the prevention of stroke. 相似文献
996.
997.
A Kayik?io?lu S Karamüsel E Mavili Y Erk K Benli 《The Cleft palate-craniofacial journal》2000,37(2):209-211
OBJECTIVE: The use of Kirschner wire for the fixation of premaxilla is a well-known method in bilateral cleft lip surgery. We report a case in which the Kirschner wire of the premaxillary fixation had migrated intrasphenoidally. RESULTS AND CONCLUSIONS: The foreign body was accidentally discovered during a cephalometric analysis and was taken out surgically through an upper lip sulcus incision. Although the wire remained asymptomatic for 10 years, it constituted a potential danger for intracranial migration. 相似文献
998.
6-Mercaptopurine metabolism in Crohn's disease: correlation with efficacy and toxicity. 总被引:28,自引:5,他引:23
下载免费PDF全文
![点击此处可从《Gut》网站下载免费的PDF全文](/ch/ext_images/free.gif)
BACKGROUND: 6-Mercaptopurine (6-MP) has confirmed short and longterm efficacy in the treatment of IBD. However, the relation between its metabolism, efficacy, and side effects is not well understood. AIMS: To assay 6-MP metabolites and to correlate levels with drug compliance, disease activity, and adverse effects of treatment. PATIENTS: Heparinised blood was obtained prior to daily administration of 6-MP in 25 adolescent Crohn's disease patients (14 ileocolitis, 11 colitis) receiving 1.2 (range 0.4-1.6) mg/kg/day for a mean of 17 (range 4-65) months. METHODS: Erythrocyte free bases 6-thioguanine (6-TG) and 6-methyl-mercaptopurine (6-MMP) were measured (pmol/8 x 10(8) red blood cells) using reverse phase high performance liquid chromatography. RESULTS: Disease activity (modified Harvey-Bradshaw index) improved significantly with 6-MP (p = 0.001). Clinical remission was achieved in 72% of patients, who stopped taking prednisone, or were successfully weaned to a low alternate day dose (< 0.4 mg/kg/OD). Remission correlated well with erythrocyte 6-TG (p < 0.05), but not 6-MMP levels. Neutropenia was associated with 6-MP use (p < 0.005), but did not correlate with erythrocyte 6-MP metabolite levels. One patient refractory to 6-MP had 6-TG, but no measureable 6-MMP production, suggesting deficient thiopurine methyl-transferase activity or poor compliance. 6-MP induced complications (hepatitis, pancreatitis, and marrow suppression) were generally associated with increased 6-MMP levels. CONCLUSIONS: These results suggest that high performance liquid chromatography measurement of erythrocyte 6-MP metabolites may provide a quantitative assessment of patient responsiveness and compliance to treatment. The data support an immunosuppressive role for 6-TG, and potential cytotoxicity of raised 6-MMP levels. 相似文献
999.
This study was designed to investigate the effect of cholestyramine on the formation of pigment gallstones in high carbohydrate diet-fed hamsters and whether that effect occurred because of cholecystokinin action. Forty seven hamsters were divided into three groups: group I(n = 16) was fed on normal rodent chow(43% carbohydrate), group II(n = 14) was fed on a high CHO diet(65% carbohydrate), group III(n = 17) was fed on a high CHO diet containing 4% cholestyramine. Gallstones developed in 0% of group I, 42.9% of group II and 5.9% of group III(P < 0.05, group II vs III). To evaluate the chronic status of cholecystokinin level, the wet weight of pancreas and the average area of pancreatic acinar in microscopic high power field were measured. There was no significant difference between group II and group III in pancreatic weight and average area of pancreatic acinar(P > 0.05). In gallbladder bile analysis, there was also no significant difference between group II and group III in cholesterol, phospholipid, total calcium, total bilirubin and bile acid levels. In conclusion, cholestyramine decreases the frequency of pigment gallstone formation in high CHO diet-fed hamsters, but it is not clear whether the mechanism of cholestyramine decreasing the gallstone formation is due to the action of cholecystokinin. 相似文献
1000.
M. A. El-Kalay M. H. Abdel-Kader† R. Y. Hamzah† S. A. Al-Shirbini† 《Artificial organs》1990,14(3):200-207
Using a plasma separator, it is possible to wash large volumes of whole blood free of plasma proteins in short periods. The novelty, however, is that the same apparatus can be used to reversibly hemolyze and reseal the red blood cells (RBCs) using hypotonic and hypertonic dialysates, respectively. This technique was assessed using the fluorescent exogenous agent uranin (fluorescein sodium). Results indicate that the encapsulation of the RBCs can be completed in under 2 h. The encapsulation efficiency of the RBCs was approximately 80% with a RBC recovery rate of 75%. 相似文献