全文获取类型
收费全文 | 6121篇 |
免费 | 359篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 157篇 |
妇产科学 | 155篇 |
基础医学 | 721篇 |
口腔科学 | 115篇 |
临床医学 | 437篇 |
内科学 | 1341篇 |
皮肤病学 | 87篇 |
神经病学 | 389篇 |
特种医学 | 206篇 |
外科学 | 1129篇 |
综合类 | 50篇 |
预防医学 | 177篇 |
眼科学 | 445篇 |
药学 | 437篇 |
中国医学 | 13篇 |
肿瘤学 | 586篇 |
出版年
2023年 | 57篇 |
2022年 | 53篇 |
2021年 | 161篇 |
2020年 | 80篇 |
2019年 | 94篇 |
2018年 | 137篇 |
2017年 | 107篇 |
2016年 | 148篇 |
2015年 | 136篇 |
2014年 | 184篇 |
2013年 | 227篇 |
2012年 | 313篇 |
2011年 | 394篇 |
2010年 | 176篇 |
2009年 | 173篇 |
2008年 | 308篇 |
2007年 | 308篇 |
2006年 | 309篇 |
2005年 | 270篇 |
2004年 | 298篇 |
2003年 | 272篇 |
2002年 | 249篇 |
2001年 | 196篇 |
2000年 | 196篇 |
1999年 | 194篇 |
1998年 | 52篇 |
1997年 | 57篇 |
1996年 | 43篇 |
1995年 | 57篇 |
1994年 | 46篇 |
1993年 | 33篇 |
1992年 | 117篇 |
1991年 | 101篇 |
1990年 | 83篇 |
1989年 | 100篇 |
1988年 | 80篇 |
1987年 | 93篇 |
1986年 | 119篇 |
1985年 | 78篇 |
1984年 | 59篇 |
1983年 | 39篇 |
1981年 | 18篇 |
1980年 | 19篇 |
1979年 | 30篇 |
1977年 | 25篇 |
1975年 | 18篇 |
1974年 | 18篇 |
1970年 | 23篇 |
1969年 | 24篇 |
1967年 | 17篇 |
排序方式: 共有6511条查询结果,搜索用时 312 毫秒
91.
BACKGROUND: Bacterial cholangitis is frequently associated with serious complications. METHODS: The plasma disappearance rates and the biliary output of bile acids and bilirubin after percutaneous transhepatic biliary drainage (PTBD) were examined in 29 patients with extrahepatic biliary obstruction. RESULTS: Twenty-nine patients were divided into the bacteria-minus (n = 17) and bacteria-plus (n = 12) groups. Decreases in the plasma bile acid and bilirubin levels of the bacteria-minus group (t1/2 = 0.38 and 3.8 days for bile acids and bilirubin, respectively) were faster than those of the bacteria-plus group (t1/2 = 1.7 and 7.5 days). The bile flow rate was significantly increased in the bacteria-plus group compared with the bacteria-minus group. The calculated values of bilirubin and bile acid in the bile were higher in the bacteria-minus group than in the bacteria-plus group. CONCLUSIONS: Bacterial colonization in the bile stimulates bile duct cells to increase bile volume and inhibits the hepatocyte transport activity of bile acids and bilirubin. 相似文献
92.
No survival benefit from combined pancreaticosplenectomy and total gastrectomy for gastric cancer 总被引:11,自引:0,他引:11
Kitamura K Nishida S Ichikawa D Taniguchi H Hagiwara A Yamaguchi T Sawai K 《The British journal of surgery》1999,86(1):119-122
BACKGROUND: It remains unknown whether extended surgery improves the survival rate of patients with gastric cancer. This study was a review of combined pancreaticosplenectomy with total gastrectomy for gastric cancer. METHODS: The clinicopathological details of 190 patients who underwent combined pancreaticosplenectomy with total gastrectomy between 1969 and 1996 were compared retrospectively with those of 206 patients who underwent total gastrectomy with splenectomy alone. RESULTS: There was no statistical difference in the survival rate when pancreaticosplenectomy was added to total gastrectomy. The mortality rate was similar, but the morbidity rate was higher in patients who had pancreaticosplenectomy. Six patients who had direct pancreatic invasion and two thought to have involved lymph nodes along the splenic artery survived for more than 5 years after operation. In the latter group, the metastatic lymph nodes along the splenic artery could have been resected without pancreatectomy. CONCLUSION: Since a combined pancreaticosplenectomy adds no survival advantage to total gastrectomy for gastric cancer, this procedure should no longer be regarded as routine. 相似文献
93.
A microcapsule suspension, a substitute for animal blood in hemolysis tests, has been developed for evaluation of the absolute hemolytic properties of circulatory artificial organs. The microcapsule suspension was made by dispersing microcapsule slurry into an ethylene glycol sodium chloride solution. The microcapsule slurry was composed of a leuco dye solution and polyurethane membrane made by the reaction between aliphatic poly-isocyanate and polyamine by interfacial polycondensation. The microcapsule was a small particle containing dye inside. The microcapsule suspension was white; the diameter of the microcapsules was from 5 to 100 microns. The specific gravity of the suspension was 1.024, and the membrane was elastic. The fluid showed Newtonian characteristics, different from animal blood, and its viscosity was approximately 5.8 mPa.s. After the microcapsules were destroyed, the leuco dye was extracted with n-hexane from the suspension and was measured by spectroscopy after being colored with acid ethanol. Hemolysis can be regarded as a fatigue fracture of cell membranes rather than a static fracture. The destruction of microcapsules by a Potter type tissue grinder was observed at a low stroke number region and was compared to rat blood. Moreover, hemolysis tests of a commercially available centrifugal blood pump and the prototype of our centrifugal pump for mechanism checks were carried out with bovine blood. The hemolysis level of the prototype pump increased with time while the hemolysis level of the commercial blood pump did not change as much as that of the control when both pumps were tested with the microcapsule suspension. These results are similar to tests utilizing bovine blood. Therefore, hemolysis tests of circulatory artificial organs completed with microcapsule suspension are expected to provide results similar to tests with animal blood. 相似文献
94.
95.
A number of experiments were conducted to compare the ability of observers to extract unidirectional and bidirectional (transparent) global-motion signals. In the unidirectional condition, the noise signal consisted of purely randomly-moving dots while in the bidirectional condition, a number of the randomly moving dots were replaced by the same number of dots moving in a specific (secondary-signal) direction. The threshold measure was the minimum number of signal dots required to determine the global-motion direction. For the bidirectional condition, parameters varied were the angular separation between the global-motion and secondary-signal directions and the strength of the secondary signal. Thresholds for unidirectional and bidirectional conditions were the same when the angular difference between global-motion and secondary-signal directions were 90 degrees or greater, i.e. the ability of observers to extract a transparent signal was the same as their ability to extract a unidirectional one. Similarly, with motion-in-depth signals, thresholds for extracting a centripetal signal were not elevated by replacing a number of the randomly-moving noise dots with the same number centrifugally-moving dots. The results are interpreted as indicating that motion signals moving between 90 and 180 degrees to the global-motion direction provide uniform masking of the global-motion signal. For angular separations less than 90 degrees, a suprathreshold secondary signal resulted in threshold elevation. This result could be due, to stronger inhibition from motion units tuned to similar (< 90 degrees) directions, broad directional-tuning of the underlying motion units (changing the task from signal detection to a signal discrimination) or a combination of the two. 相似文献
96.
Apolipoproteins J and E co-localise with amyloid in gelatinous drop-like and lattice type I corneal dystrophies 下载免费PDF全文
K. Nishida A. Quantock A. Dota N. Choi-Miura S. Kinoshita 《The British journal of ophthalmology》1999,83(10):1178-1182
AIMS: Apolipoprotein J (apoJ) and apolipoprotein E (apoE) are thought to contribute to amyloid formation in patients with Alzheimer's disease. The aim of this investigation was to discover whether or not these apolipoproteins associate with corneal amyloid in gelatinous drop-like corneal dystrophy (GDCD) and lattice corneal dystrophy type I (LCD-I). METHODS: Corneas from three eyes of three patients with GDCD and one eye of one patient with LCD-I were examined immunohistochemically using antibodies against apoJ and apoE. Two normal corneas were similarly examined. Tissue sections of brain from a patient with Alzheimer's disease were used as positive controls for the antibodies. For all negative controls, mouse IgG was used instead of the primary antibody. RESULTS: Intense apoJ and apoE immunoreactivities were found in congophilic amyloid deposits in GDCD and LCD-I. These deposits were located subepithelially in GDCD, and subepithelially and intrastromally in LCD-I. In GDCD, immunostaining of subepithelial amyloid with anti-apoJ was noticeably stronger than with anti-apoE. CONCLUSIONS: As in senile plaques in brain from a patient with Alzheimer's disease, apoJ and apoE co-localise with amyloid in corneas with GDCD and LCD-I. 相似文献
97.
L-cis diltiazem attenuates intracellular Ca(2+) overload by metabolic inhibition in guinea pig myocytes 总被引:3,自引:0,他引:3
We have previously demonstrated that treatment with L-cis diltiazem reduced cardiac infarct size in vivo. To examine the effect of L-cis diltiazem on Ca(2+) overload induced by ischemia/reperfusion, we used a model for Ca(2+) overload produced by metabolic inhibition in isolated guinea pig myocytes. Intracellular Ca(2+) concentration ([Ca(2+)](i)) was quantified by fura-2 fluorescence microscopy and Ca(2+) overload was induced by inclusion of 1 microM of carbonyl cyanide m-chrolophenylhydrazone (CCCP) for 40 min treatment followed by washout for 30 min. This treatment caused a large [Ca(2+)](i) elevation as well as a sustained contracture of the cardiomyocytes. The increase was suppressed by 10 microM of 2-[2-[4-(4-nitrobenzyloxy) phenyl] ethyl] isothiourea methanesulphonate (KB-R7943), a specific inhibitor of the Na(+)/Ca(2+) exchanger, but not by nitrendipine (10 microM). L-cis Diltiazem (10 microM) attenuated the [Ca(2+)](i) increase, suggesting that L-cis diltiazem elicits a cardioprotective effect via attenuation of the [Ca(2+)](i) increase induced by metabolic inhibition and energy repletion. 相似文献
98.
l-cis Diltiazem, an optical isomer of diltiazem, protects against myocardial dysfunction in vitro, whereas its Ca2+ channel blocking activity is about 100 times less potent than that of diltiazem. However, there is no evidence that l-cis diltiazem actually protects against ischemia/reperfusion injury in vivo. To assess this, we employed an anesthetized rabbit model, where the left circumflex artery was occluded for 15 min and reperfused for 360 min. Treatment with diltiazem before and during ischemia (bolus 200 microg/kg and 15 microg/kg per minute for 25 min, i.v.; 575 microg/kg total) showed slightly depressed hemodynamic parameters, while l-cis diltiazem (1150 microg/kg) had no effect. Treatment with l-cis diltiazem produced a high recovery of the thickening fraction and limited the infarct size in a dose-dependent manner. Furthermore, the treatment with l-cis diltiazem (1150 microg/kg) or diltiazem (575 microg/kg) 5 min before reperfusion also limited the infarct size, but not after reperfusion. These results suggest that l-cis diltiazem affects some events in the onset of reperfusion, independently of Ca2+-channel-blocking action. Our observations are the first to show that l-cis diltiazem demonstrated its cardioprotective action in the ischemic rabbit heart in vivo. 相似文献
99.
Hasuo Y Nishida T Eguchi H Kuromastu H Tanaka H Sugiyama T Yakushiji M 《Oncology reports》1996,3(1):123-124
The outcome of advanced endometrial carcinoma is poor, indicating the need for new treatment modalities. We report a case of stage IVb endometrial carcinoma who received neoadjuvant chemotherapy given via intra-arterial infusion with carboplatin and pirarubicin. This treatment reduced the volume of tumors, even those in the lung. Then we succeeded in performing cyto-reduction. The patient is doing well 12 months post-therapy. 相似文献
100.
Honda O Nishimura M Tomiyama N Johkoh T Mihara N Kozuka T Naito H Hamada S Kagawa K Nishida T Ichikawa Y Yamamoto S Nakamura H 《Investigative radiology》2000,35(9):534-538
RATIONALE AND OBJECTIVES: To investigate whether expiratory high-resolution computed tomography (HRCT) is more useful than inspiratory HRCT for the detection of early-phase diffuse alveolar damage. METHODS: Eleven anesthetized rabbits were scanned with both inspiratory and expiratory HRCT every 30 minutes during mechanical ventilation. Ten rabbits were killed after the detection of pulmonary abnormalities on both inspiratory and expiratory HRCT. The remaining rabbit was killed when the pulmonary abnormalities appeared only on expiratory HRCT. RESULTS: In four cases (36%), the abnormal findings were detected earlier on expiratory HRCT than on inspiratory HRCT. In seven cases (64%), the abnormalities appeared simultaneously on inspiratory and expiratory HRCT. In all 11 cases, the histopathological changes of areas with abnormal CT findings corresponded to the exudative or proliferative phase of diffuse alveolar damage. CONCLUSIONS: Expiratory HRCT has the potential to detect the abnormalities of diffuse alveolar damage earlier than inspiratory HRCT. 相似文献