全文获取类型
收费全文 | 6597篇 |
免费 | 371篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 110篇 |
妇产科学 | 115篇 |
基础医学 | 864篇 |
口腔科学 | 295篇 |
临床医学 | 421篇 |
内科学 | 1774篇 |
皮肤病学 | 149篇 |
神经病学 | 565篇 |
特种医学 | 195篇 |
外科学 | 899篇 |
综合类 | 28篇 |
预防医学 | 207篇 |
眼科学 | 80篇 |
药学 | 512篇 |
中国医学 | 10篇 |
肿瘤学 | 689篇 |
出版年
2023年 | 36篇 |
2022年 | 78篇 |
2021年 | 102篇 |
2020年 | 66篇 |
2019年 | 90篇 |
2018年 | 116篇 |
2017年 | 98篇 |
2016年 | 123篇 |
2015年 | 134篇 |
2014年 | 193篇 |
2013年 | 209篇 |
2012年 | 388篇 |
2011年 | 467篇 |
2010年 | 209篇 |
2009年 | 176篇 |
2008年 | 359篇 |
2007年 | 376篇 |
2006年 | 333篇 |
2005年 | 378篇 |
2004年 | 345篇 |
2003年 | 381篇 |
2002年 | 359篇 |
2001年 | 162篇 |
2000年 | 165篇 |
1999年 | 190篇 |
1998年 | 93篇 |
1997年 | 72篇 |
1996年 | 66篇 |
1995年 | 66篇 |
1994年 | 52篇 |
1993年 | 40篇 |
1992年 | 106篇 |
1991年 | 90篇 |
1990年 | 103篇 |
1989年 | 83篇 |
1988年 | 72篇 |
1987年 | 71篇 |
1986年 | 76篇 |
1985年 | 65篇 |
1984年 | 58篇 |
1983年 | 53篇 |
1982年 | 27篇 |
1980年 | 26篇 |
1979年 | 27篇 |
1978年 | 24篇 |
1977年 | 22篇 |
1973年 | 15篇 |
1971年 | 22篇 |
1970年 | 17篇 |
1969年 | 19篇 |
排序方式: 共有7002条查询结果,搜索用时 15 毫秒
31.
T Mochizuki Y Izumi Y Kato T Okazaki M Tashima O Nagauchi H Sawada H Uchino 《Journal of Japan Haematological Society》1987,50(6):1183-1189
32.
Junji Furukawa Jitsuo Kiji Hisatoshi Konishi Kazuyoshi Yamamoto Shin-Ichi Mitani Susumu Yoshikawa 《Macromolecular chemistry and physics.》1973,174(1):65-71
The behavior of hydridonickel coordination compounds as catalysts for the oligomerization and polymerization of butadiene in various solvents was studied. In the presence of alcohol bis(tricyclohexylphosphine)chlorohydridonickel ( 4 , X = Cl) (HNiCl[P(C6H11)3]2) catalyzes the linear dimerization. With hydridotetrakis(phosphite)nickel(1+) ( 2 ) ([HNi{P(OR)3}4]+), which is prepared from tetrakis(phosphite)nickel ( 1 ) (Ni[P(OR)3]4) and trifluoroacetic acid, dimerization occurs in sec-alcohol but there is no reaction in tert-alcohol. The main product is 2-methylenevinylcyclopentane ( 8 ). The other products are 4-vinylcyclohexene ( 10 ), 1,5-cyclooctadiene ( 5 ), 1,3,7-octatriene ( 7 ) and 1,3,6-octatriene ( 9 ). The hydridonickel coordination compound, prepared with inorganic acids, does not afford the dimers but the 1,4-trans polymer. 相似文献
33.
Kumasaka T Mitani K Izumi H Miyamoto H Takahashi K Fukuchi Y Suda K 《Histopathology》2003,43(2):189-193
AIMS: We investigated a rare case of small vessel vasculitis (SVV) limited to pleuropulmonary manifestations, possibly induced by endotoxin, to determine the activation of immuno-mediated cells and endothelia in the pleuropulmonary circulation. METHODS AND RESULTS: A 44-year-old man with a high fever was X-rayed, revealing bilateral pleural effusion and atelectasis in the chest. His laboratory data were within normal limits except for a high white blood cell count and a high C-reactive protein level. Autoantibodies including anti-neutrophil cytoplasmic antibody were negative. Endotoxin was detected in his sera, but repeated cultures of sputa, urine, blood and the pleural effusion were negative for bacteria. Video-assisted thoracic surgery was performed and lung and parietal pleura specimens were obtained. Histology showed arterioles or small arteries infiltrated by monocytes or neutrophils with fibrinoid necrosis and acute or chronic venulitis. A diagnosis of SVV in the lung and pleura was made. Immunohistochemistry revealed that interleukin (IL)-1beta was expressed in monocytes and vascular cell adhesion molecule (VCAM)-1 on endothelial cells in the vasculitic lesions in the lung. CONCLUSIONS: Endotoxin possibly induced the inflammation in this apparently unique case of pleuropulmonary small vessel vasculitis. Immunohistochemistry revealed the expression of IL-1beta and VCAM-1 which may have caused activation of monocytes and endothelial cells within the vasculitic lesions. 相似文献
34.
35.
36.
Heterotransplantation of gastric adenocarcinoma, induced in dog by N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) has been attempted to nude mouse. Biopsied materials from Borrmann 3 type carcinoma, which showed signet-ring cell carcinoma at the subcardiac region of a beagle dog, were inoculated into the muscles of the hind legs of BALB/c-nu/nu nude mice. Serial transmission was obtained in 2 lives, so far 4-5 passages. The histological findings of the grafts were mainly poorly differentiated adenocarcinomas. 相似文献
37.
Shun Kaneko Masayuki Kurosaki Toshie Mashiba Hiroyuki Marusawa Masahiko Kondo Yuji Kojima Yasushi Uchida Hideki Fujii Takehiro Akahane Hitoshi Yagisawa Atsunori Kusakabe Haruhiko Kobashi Takehiko Abe Hideo Yoshida Chikara Ogawa Koichiro Furuta Nobuharu Tamaki Keiji Tsuji Tomomichi Matsushita Namiki Izumi the Japanese Red Cross Liver Study Group 《Journal of medical virology》2023,95(1):e28210
Nucleos(t)ide analogs (NAs) cannot completely suppress the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). This study aimed to identify the risk factors for HCC development in naïve CHB patients treated with current NA. Patients receiving NA (n = 905) were recruited retrospectively from the 17 hospitals of the Japanese Red Cross Liver Study Group. All treatment-naïve patients had been receiving current NA continuously for more than 1 year until the end of the follow-up. We analyzed the accuracy of predictive risk score using the area under receiver operating characteristic curve. The albumin–bilirubin (ALBI) score was significantly improved by NA therapy (−0.171 ± 0.396; p < 0.001 at Week 48). A total of 72 (8.0%) patients developed HCC over a median follow-up of 6.2 (1.03–15.7) years. An independent predictive factor of HCC development was older age, cirrhosis, lower platelet counts at baseline and ALBI score, and alpha-fetoprotein (AFP) at 1 year after NA therapy according to multivariate analysis. The accuracy was assessed using the PAGE-B, mPAGE-B, aMAP, APA-B, and REAL-B scores that included these factors. Discrimination was generally acceptable for these models. aMAP and REAL-B demonstrated high discrimination with 0.866/0.862 and 0.833/0.859 for 3- and 5-year prediction from the status of 1 year after NA therapy, respectively. Baseline age and platelet count, as well as ALBI and AFP one year after NA, were useful for stratifying carcinogenesis risk. The aMAP and REAL-B scores were validated with high accuracy in Japanese CHB patients. 相似文献
38.
Tomoaki Yuhi Akihiko Wada Ryuichi Yamamoto Masanobu Urabe Hiromi Niina Futoshi Izumi Toshihiko Yanagital 《Naunyn-Schmiedeberg's archives of pharmacology》1994,350(2):209-212
We have previously reported that in bovine adrenal chromaffin cells Ptychodiscus brevis toxin-3 (PbTx-3) does not alter the veratridine-induced 22Na influx when given alone, but increases the influx of 22Na when co-applied with either - or -scorpion venom (Wada et al. 1992). In the present study, we characterized [3H]PbTx-3 binding in bovine adrenal chromaffin cells. [3H]PbTx-3 binding was saturable, reversible and of high-affinity with an equilibrium dissociation constant (Kd) of 32.0±4.9 nmol/1 and a maximum binding capacity Bmax of 6.2 ± 1.2 pmol/4 × 106 cells (4.5 ± 0.9 pmol/mg cell protein). A Hill plot revealed the lack of cooperative interaction among the binding sites. Unlabelled PbTx-3 inhibited [3H]PbTx-3 binding with an IC50 of 31 nmol/l. However, tetrodotoxin, veratridine, - and -scorpion venom, or veratridine in combination with either - or -scorpion venom did not alter [3H]PbTx-3 binding. All these results suggest that PbTx-3 binds to a site (site 5) distinct from the previously known four toxin binding sites, which does not gate voltage-dependent Na channels by itself, but is specifically involved in the allosteric modulation of Na channels in adrenal medullary cells.
Correspondence to: A. Wada at the above address 相似文献
39.
The incidence and clinicopathologic features of unilateral multicentric breast cancer (UMBC) were studied by mammary gland
serial sectioning in 116 cases of clinically defined monocentric breast cancer (MONBC) examined histopathologically at the
Nagano Cancer Detection Center. UMBC was defined as: 1) histopathologically discontinuous tumors each with an intraductal
spread, 2) at least one tumor-free section separating two tumors, and 3) a large primary tumor and other small secondary tumors.
UMBC was detected in 23 of 116 cases (19.8%), all with one secondary tumor. Primary and secondary tumors were located in the
same quadrant in 34.8% and in different ones in 65.2%. The secondary tumors were <5 mm in size in 56.5%. Secondary tumors,
averaging 8.3 mm in size and 25.5 mm in distance from the primary tumor, were almost exclusively noninvasive carcinomas, including
15 (65.4%) noninvasive ductal carcinomas and several special types. The primary and secondary tumors were of the same histologic
type in 3 of 23 cases. UMBC patients averaged 6 years younger than MONBC patients, and the incidence of UMBC tended to be
higher in younger patients (p<0.1). UMBC tended to occur more frequently in quadrant with an average histologie tumor size
significantly smaller than that in MONBC (p<0.01). The histologie types of the primary tumor in UMBC and MONBC were similar,
with common types predominant. Lymph node metastases tended to be slightly more frequent in MONBC.
This high incidence of UMBC calls for careful attention when considering breast conserving therapy. 相似文献
40.