全文获取类型
收费全文 | 66005篇 |
免费 | 3035篇 |
国内免费 | 425篇 |
专业分类
耳鼻咽喉 | 653篇 |
儿科学 | 1186篇 |
妇产科学 | 957篇 |
基础医学 | 8742篇 |
口腔科学 | 2109篇 |
临床医学 | 4520篇 |
内科学 | 15978篇 |
皮肤病学 | 1566篇 |
神经病学 | 4692篇 |
特种医学 | 2458篇 |
外科学 | 11349篇 |
综合类 | 353篇 |
一般理论 | 3篇 |
预防医学 | 1963篇 |
眼科学 | 1105篇 |
药学 | 4128篇 |
中国医学 | 165篇 |
肿瘤学 | 7538篇 |
出版年
2023年 | 329篇 |
2022年 | 836篇 |
2021年 | 1394篇 |
2020年 | 696篇 |
2019年 | 1021篇 |
2018年 | 1360篇 |
2017年 | 1035篇 |
2016年 | 1199篇 |
2015年 | 1278篇 |
2014年 | 1720篇 |
2013年 | 2098篇 |
2012年 | 3360篇 |
2011年 | 3828篇 |
2010年 | 2131篇 |
2009年 | 1852篇 |
2008年 | 3331篇 |
2007年 | 3617篇 |
2006年 | 3499篇 |
2005年 | 3722篇 |
2004年 | 3607篇 |
2003年 | 3539篇 |
2002年 | 3565篇 |
2001年 | 1559篇 |
2000年 | 1666篇 |
1999年 | 1602篇 |
1998年 | 952篇 |
1997年 | 718篇 |
1996年 | 710篇 |
1995年 | 625篇 |
1994年 | 548篇 |
1993年 | 504篇 |
1992年 | 994篇 |
1991年 | 931篇 |
1990年 | 853篇 |
1989年 | 848篇 |
1988年 | 813篇 |
1987年 | 763篇 |
1986年 | 766篇 |
1985年 | 672篇 |
1984年 | 526篇 |
1983年 | 431篇 |
1982年 | 236篇 |
1981年 | 239篇 |
1979年 | 396篇 |
1978年 | 273篇 |
1977年 | 227篇 |
1975年 | 220篇 |
1974年 | 240篇 |
1973年 | 229篇 |
1969年 | 231篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Shigeo Nakamura Takashi Koshikawa Tsuneko Sato Kayoko Hayashi Taizan Suchi 《Pathology international》1992,42(10):745-750
We describe a 54-year-old woman with primary pulmonary adenocarcinoma showing a characteristic papillary architecture and prominent cilia formation. Immunohistochemically, the tumor cells were positive for carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA) and Leu Ml, and negative for lactoferrin and surfactant apoprotein. An ultrastructural study also indicated differentiation toward bronchial surface epithelial cells. To our knowledge, this type of neoplasm has not been reported as peripheral-type adenocarcinoma of the lung. Acta Pathol Jpn 42: 745–750, 1992. 相似文献
92.
Enzymes induced by ethanol differently affect the pharmacokinetics of trichloroethylene and 1,1,1-trichloroethane. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Occupational and environmental medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
This study was undertaken to clarify the effect of enzymes induced by ethanol consumption on the pharmacokinetics of trichloroethylene (TRI, a highly metabolised substance) and 1,1,1-trichloroethane (1,1,1-TRI, a poorly metabolised substance). Rats maintained on a control liquid diet or a liquid diet containing ethanol (2 g/day/rat) for not less than three weeks were exposed to either TRI (50, 100, 500, and 1000 ppm) or 1,1,1-TRI (50, 100, and 500 ppm) by inhalation for six hours and the concentration of each compound in the blood and the urinary excretion of metabolites (trichloroethanol and trichloroacetic acid) were measured over several hours. Ethanol, which increased the in vitro metabolism of both compounds about fivefold, enhanced the in vivo metabolism of TRI only at high levels of exposure (marginally at 500 and considerably at 1000 ppm), whereas the metabolism of 1,1,1-TRI was enhanced at all concentrations tested. Moreover, there was a definite difference in the effect of induction of enzymes between the two solvents: the enhanced metabolism of TRI in vivo was shown by a decrease in the blood concentration of TRI as well as by an increase in the urinary excretion of its metabolites, whereas that of 1,1,1-TRI was shown by an increase in the urinary excretion of its metabolites alone. These results suggest that the induction of enzymes differentially affects the pharmacokinetics of TRI and 1,1,1-TRI in human occupational exposure: TRI metabolism may be increased only at concentrations much higher than the current occupational exposure limit (mostly 50 ppm), whereas 1,1,1-TRI metabolism may be increased at an exposure similar to occupational exposure. 相似文献
93.
94.
95.
H. Kitamura T. Shioiri M. Itoh Y. Sato K. Shichiri & T. Someya 《Journal of intellectual disability research : JIDR》2007,51(10):812-820
Background Evidence suggests that, as a group, patients with schizophrenia have intellectual deficits that may precede the manifestation of psychotic symptoms; however, how successfully intelligence tests are able to discriminate schizophrenia from other psychotic disorders has yet to be investigated in detail. Methods Using Wechsler Adult Intelligence Scale – Revised (WAIS‐R) data for 55 inpatients with schizophrenia and 28 inpatients with non‐schizophrenic psychotic disorders (NSPD) (schizophreniform disorder, brief psychotic disorder, delusional disorder, psychotic disorder due to a general medical condition, and psychotic disorders not otherwise specified), intelligence performance was compared between schizophrenia and NSPD and among different subtypes of schizophrenia. Results There were no significant differences in intelligence quotient (IQ), verbal IQ (VIQ) and performance IQ (PIQ) discrepancy, and subtest scores of WAIS‐R between the patients with schizophrenia and those with NSPD. These diagnostic groups were not discriminated well by any WAIS‐R variables. Schizophrenia patients with prominent negative symptoms, on the other hand, had a significantly larger IQ discrepancy (VIQ > PIQ) than those without prominent negative symptoms and NSPD patients. Intelligence performance in schizophrenia did not differ with respect to diagnostic subtypes and longitudinal courses. Conclusions The current study failed to show diagnostic usefulness of WAIS‐R in discriminating schizophrenia and other psychoses. A diagnosis of schizophrenia does not significantly impact intellectual deficits in psychotic disorders. 相似文献
96.
Yoshie Ochiai Kazuhiro Kurisu Takashi Kajiwara Hiroshi Kumeda Ryuji Tominaga 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(2):81-83
We describe a case of type B aortic dissection with large ascending aortic aneurysm occurring 12.8 years after aortic root
replacement (Cabrol procedure) in a non-Marfan patient with cystic medial necrosis of the aorta. We have successfully performed
an extended total aortic arch replacement using a four-branched graft through the “L-indsion” approach (a combination of a
left anterior thoracotomy and upper half median sternotomy). Of note, a histological specimen from the aneurysmal ascending
aortic wall revealed “healed aortic dissection” with fibrous tissue replacing the media and intima in addition to multiple
foci of cystic medial necrosis. 相似文献
97.
Kimie Sai Takashi Umemura Atsuya Takagi Ryuichi Hasegawa Yuji Kurokawa 《Cancer science》1992,83(1):45-51
The roles of glutathione (GSH), cysteine, vitamin C., liposome-encapsulated superoxide dismutase (L-SOD) and vitamin E in preventing oxidative DNA damage and cytotoxicity in the rat kidney after administration of potassium bromate (KBrO3 ) to male F344 rats were investigated by measuring 8-hydroxydeoxyguanosine (8-OH-dG), an oxidative DNA product, lipid peroxidation (LPO) levels and relative kidney weight (RKW). Combined pre- and posttreatment of animals with 2 × 800 mg/kg GSH i.p. inhibited the increase of 8-OH-dG, LPO levels and RKW caused by 80 mg/kg KBrO3 i.p. administration. In contrast, pretreatment with 0.3 ml/kg diethylmaleate (DEM) i.p., a depletor of tissue GSH, was associated with elevation of 8-OH-dG, LPO levels and RKW after a 20 mg/kg KBrO3 i.p. treatment, which itself caused no change. Administration of KBrO3 itself reduced renal non-protein thiol levels, but this was inhibited by the two doses of exogenous GSH. Combined treatment with DEM and KBrO3 lowered the non-protein thiol level in the kidney more than did DEM treatment alone. Protective effects against the oxidative damage caused by KBrO3 were also observed for pre- and posttreatment with 400 mg/kg cysteine i.p., another sulfhydryl compound, and daily i.g. application of 200 mg/kg vitamin C for 5 days. However, no influence was evident after pre- and posttreatment with 18,000 U/kg L-SOD i.p. or daily i.g. 100 mg/kg of vitamin E for 5 days. The results suggest that intracellular GSH plays an essential protective role against renal oxidative DNA damage and nephrotoxicity caused by KBrO3 . 相似文献
98.
99.
Reversible low-molecular-weight proteinuria in patients with distal renal tubular acidosis 总被引:2,自引:0,他引:2
Takashi Igarashi Hidehiko Kawato Shigehiko Kamoshita 《Pediatric nephrology (Berlin, Germany)》1990,4(6):593-596
Four patients with untreated renal tubular acidosis had a urinary excretion of low-molecular-weight (LMW) proteins which was restored to normal by alkali therapy. Hypokalaemic proximal tubular damage in untreated patients with distal renal tubular acidosis is believed to be the cause of LMW proteinuria. An examination of urinary excretion of LMW proteins is useful for determining hypokalaemic proximal tubular dysfunction, as well as the efficiency of alkali therapy. 相似文献
100.