全文获取类型
收费全文 | 10986篇 |
免费 | 546篇 |
国内免费 | 96篇 |
专业分类
耳鼻咽喉 | 151篇 |
儿科学 | 193篇 |
妇产科学 | 65篇 |
基础医学 | 1201篇 |
口腔科学 | 228篇 |
临床医学 | 637篇 |
内科学 | 3063篇 |
皮肤病学 | 188篇 |
神经病学 | 754篇 |
特种医学 | 452篇 |
外科学 | 1846篇 |
综合类 | 48篇 |
预防医学 | 241篇 |
眼科学 | 219篇 |
药学 | 683篇 |
中国医学 | 60篇 |
肿瘤学 | 1599篇 |
出版年
2023年 | 73篇 |
2022年 | 154篇 |
2021年 | 323篇 |
2020年 | 185篇 |
2019年 | 250篇 |
2018年 | 326篇 |
2017年 | 223篇 |
2016年 | 321篇 |
2015年 | 316篇 |
2014年 | 379篇 |
2013年 | 457篇 |
2012年 | 702篇 |
2011年 | 838篇 |
2010年 | 467篇 |
2009年 | 357篇 |
2008年 | 657篇 |
2007年 | 730篇 |
2006年 | 697篇 |
2005年 | 708篇 |
2004年 | 701篇 |
2003年 | 696篇 |
2002年 | 680篇 |
2001年 | 123篇 |
2000年 | 66篇 |
1999年 | 99篇 |
1998年 | 128篇 |
1997年 | 124篇 |
1996年 | 101篇 |
1995年 | 89篇 |
1994年 | 81篇 |
1993年 | 68篇 |
1992年 | 43篇 |
1991年 | 51篇 |
1990年 | 54篇 |
1989年 | 39篇 |
1988年 | 48篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 24篇 |
1984年 | 14篇 |
1983年 | 28篇 |
1982年 | 18篇 |
1981年 | 22篇 |
1980年 | 18篇 |
1979年 | 9篇 |
1978年 | 18篇 |
1977年 | 17篇 |
1976年 | 12篇 |
1975年 | 11篇 |
1973年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Homepages are redesigned or modified very frequently; therefore,please note that comments in this section are based on the contentsof the homepage at the time of writing.
View larger version (55K):
[in this window]
[in a new window]
View larger version (38K):
[in this window]
[in a new window]
View larger version (81K):
[in this window]
[in a new window]
The UK National Cancer Research Institute (http://www.ncri.org.uk) National Cancer Research Network (http://www.ncri.org.uk/includes/ncrn.htm) National Translational Cancer Research Network (http://www.ntrac.org.uk/) The National Cancer Research 相似文献
62.
Daigo Murata Yoshio Endo Tohru Obata Kazuki Sakamoto Yasuhiro Syouji Masakazu Kadohira Akira Matsuda Takuma Sasaki 《Drug metabolism and disposition》2004,32(10):1178-1182
The antitumor 3'-ethynyl nucleosides, 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)cytosine (ECyd) and 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)uridine (EUrd), are potent inhibitors of RNA polymerases and show excellent antitumor activity against various human solid tumors in xenograft models. ECyd is being investigated in phase I clinical trials as a novel anticancer drug possessing a unique antitumor action. ECyd and EUrd require the activity of uridine/cytidine kinase (UCK) to produce the corresponding active metabolite. The UCK family consists of two members, UCK1 and UCK2, and both UCKs are expressed in many tumor cells. It was unclear, however, whether UCK1 or UCK2 is responsible for the phosphorylation of the 3'-ethynyl nucleosides. We therefore established cell lines that are highly resistant to the 3'-ethynyl nucleosides from human fibrosarcoma HT-1080 and gastric carcinoma NUGC-3. All the resistant cell lines showed a high cross-resistance to ECyd and EUrd. As a result of cDNA sequence analysis, we found that UCK2 mRNA expressed in EUrd-resistant HT-1080 cells has a 98-base pair deletion of exon 5, whereas EUrd-resistant NUGC-3 cells were harboring the point mutation at nucleotide position 484 (C to T) within exon 4 of UCK2 mRNA. This mutation was confirmed by genome sequence analysis of the UCK2 gene. Moreover, the expression of UCK2 protein was decreased in these resistant cells. In contrast, no mutation in the mRNA or differences in protein expression levels of UCK1 were shown in the EUrd-resistant HT-1080 and NUGC-3 cells. These results suggest that UCK2 is responsible for the phosphorylation and activation of the antitumor 3'-ethynyl nucleosides. 相似文献
63.
64.
Takaaki Konuma Shohei Mizuno Tadakazu Kondo Yasuyuki Arai Naoyuki Uchida Satoshi Takahashi Masatsugu Tanaka Takuro Kuriyama Shigesaburo Miyakoshi Makoto Onizuka Shuichi Ota Yasuhiro Sugio Yasushi Kouzai Toshiro Kawakita Hikaru Kobayashi Yukiyasu Ozawa Takafumi Kimura Tatsuo Ichinohe Yoshiko Atsuta Masamitsu Yanada for the Adult Acute Myeloid Leukemia Working Group of the Japanese Society for Transplantation Cellular Therapy 《Blood cancer journal》2022,12(5)
Unrelated cord blood transplantation (CBT) is an alternative curative option for adult patients with acute myeloid leukemia (AML) who need allogeneic hematopoietic cell transplantation (HCT) but lack an HLA-matched related or unrelated donor. However, large-scale data are lacking on CBT outcomes for unselected adult AML. To investigate the trends of survival and engraftment after CBT over the past 22 years, we retrospectively evaluated the data of patients with AML in Japan according to the time period of CBT (1998–2007 vs 2008–2013 vs 2014–2019). A total of 5504 patients who received single-unit CBT as first allogeneic HCT for AML were included. Overall survival (OS) at 2 years significantly improved over time. The improved OS among patients in ≥ complete remission (CR)3 and active disease at CBT was mainly due to a reduction of relapse-related mortality, whereas among patients in first or second CR at CBT, this was due mainly to a reduction of non-relapse mortality. The trends of neutrophil engraftment also improved over time. This experience demonstrated that the survival and engraftment rate after CBT for this group has improved over the past 22 years.Subject terms: Acute myeloid leukaemia, Cancer immunotherapy 相似文献
65.
Kayo Sugiyama Subaru Tanabe Hirotaka Watanuki Masato Tochii Yasuhiro Futamura Satoshi Makino Katsuhiko Matsuyama 《Clinical Case Reports》2022,10(5)
Life‐threatening cardiac events may be misdiagnosed as acute aortic dissection because of notable symptom mimicry. We report the case of a 72‐year‐old male patient with presentations presumed to be of aortic origin. However, surgery revealed posterior free‐wall perforation in the left ventricle caused by the occlusion of an obtuse marginal branch. 相似文献
66.
A novel compound RS-0466 reverses beta-amyloid-induced cytotoxicity through the Akt signaling pathway in vitro 总被引:17,自引:0,他引:17
Nakagami Y Nishimura S Murasugi T Kubo T Kaneko I Meguro M Marumoto S Kogen H Koyama K Oda T 《European journal of pharmacology》2002,450(1):11-17
In order to determine whether 5-[bis(carboxymethyl) amino]-2-carboxy4-cyano-3-thiopheneacetic acid distrontium salt (S12911-2) inhibits bone resorption by acting on the differentiation and/or function of osteoclasts, its effects were assessed on the 1,25-dihydroxyvitamin D(3)-induced expression of carbonic anhydrase II and vitronectin receptor in chicken bone marrow cells, and on the resorbing activity of authentic rat osteoclasts cultured on bone slices. S12911-2 dose-dependently inhibited, after a 6-day exposure, the expression of carbonic anhydrase II and vitronectin receptor in stimulated osteoclasts (46% and 40%, respectively, at 10(-3) M Sr(2+), P<0.05). A pre-incubation of bone slices with S12911-2 induced a dose-dependent inhibition of bone resorbing activity from 32% at 10(-4) M Sr(2+) to 66% at 10(-3) M Sr(2+) (P<0.05 in each case). A continuous incubation (10(-3) M Sr(2+)) induced a greater inhibition of bone resorbing activity (73%, P<0.05). The inhibition of bone resorption obtained specifically with S12911-2 is related to an inhibition of the differentiation and resorbing activity of the osteoclasts. 相似文献
67.
Masaham Kinoshita Yasuhiro Nakamura Ryuji Nakano Minoru Morimatsu Seiichi Fukuda Yasuhiro Nishimi Takeo Hashimoto 《Fetal and pediatric pathology》1989,9(4):445-457
The clinical features and morphological findings in 31 Japanese infants with trisomy 18 are presented. The majority were small-for-date infants. There was no sex predominance in our series, as opposed to male female ratios of 1:3 reported in the literature. The average age at death was greater in females than in males. Cardiovascular anomalies were consistently present; ventricular septar defect and patent ductus arteriosus being the most common malformations. Various other internal malformations including the Arnold-Chiari malformation were observed. 相似文献
68.
Haruhisa Kato Makiko Naito Tomoko Saito Takuto Hideyama Yasuhiro Suzuki Takashi Kimura Shin Kwak Hitoshi Aizawa 《JOURNAL OF CLINICAL NEUROLOGY》2022,18(4):463
Background and PurposeAmyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease. Selective deficiency of edited adenosine deaminase acting on RNA 2 (ADAR2), a key molecule in the acquisition of Ca2+ resistance in motor neurons, has been reported in sporadic ALS (sALS) spinal motor neurons. Since ADAR2 activity is positively regulated by prolyl isomerase Protein never in mitosis gene A interacting-1 (Pin1), a known phosphorylation-dependent peptidyl-prolyl cis/trans isomerase, we investigated Pin1 expression in spinal motor neurons in sALS.MethodsSpecimens of the spinal cord were obtained from the lumbar region in eight sALS patients and age-matched five controls after postmortem examinations. The specimens were double stained with anti-Pin1 and anti-TAR DNA-binding protein of 43 kDa (TDP-43) antibodies, and examined under a fluorescence microscope.ResultsThis study analyzed 254 and 422 spinal motor neurons from 8 sALS patients and 5 control subjects, respectively. The frequency of motor neurons with high cytoplasmic Pin1 expression from the spinal cord did not differ significantly between sALS specimens without cytoplasmic TDP-43 inclusions and control specimens. However, in sALS specimens, neurons for which the Pin1 immunoluminescence intensity in the cytoplasm was at least twice that in the background were more common in specimens with cytoplasmic TDP-43 inclusions (p<0.05 in χ2 test).ConclusionsIn sALS, neurons with higher expression levels of Pin1 levels had more TDP-43 inclusions. Despite the feedback mechanism between Pin1 and ADAR2 being unclear, since Pin1 positively regulates ADAR2, our results suggest that higher Pin1 expression levels in motor neurons with TDP-43 pathology from sALS patients represent a compensatory mechanism. 相似文献
69.
Satoshi Gando Atsushi Shiraishi Takeshi Wada Kazuma Yamakawa Seitaro Fujishima Daizoh Saitoh Shigeki Kushimoto Hiroshi Ogura Toshikazu Abe Toshihiko Mayumi Junichi Sasaki Joji Kotani Naoshi Takeyama Ryosuke Tsuruta Kiyotsugu Takuma Shin-ichiro Shiraishi Yasukazu Shiino Taka-aki Nakada Kohji Okamoto Yuichiro Sakamoto Akiyoshi Hagiwara Satoshi Fujimi Yutaka Umemura Yasuhiro Otomo 《Medicine》2022,101(32)
Tranexamic acid (TXA) reduces the risk of bleeding trauma death without altering the need for blood transfusion. We examined the effects of TXA on coagulation and fibrinolysis dynamics and the volume of transfusion during the early stage of trauma. This subanalysis of a prospective multicenter study of severe trauma included 276 patients divided into propensity score–matched groups with and without TXA administration. The effects of TXA on coagulation and fibrinolysis markers immediately at (time point 0) and 3 hours after (time point 3) arrival at the emergency department were investigated. The transfusion volume was determined at 24 hours after admission. TXA was administered to the patients within 3 hours (median, 64 minutes) after injury. Significant reductions in fibrin/fibrinogen degradation products and D-dimer levels from time points 0 to 3 in the TXA group compared with the non-TXA group were confirmed, with no marked differences noted in the 24-hour transfusion volumes between the 2 groups. Continuously increased levels of soluble fibrin, a marker of thrombin generation, from time points 0 to 3 and high levels of plasminogen activator inhibitor-1, a marker of inhibition of fibrinolysis, at time point 3 were observed in both groups. TXA inhibited fibrin(ogen)olysis during the early stage of severe trauma, although this was not associated with a reduction in the transfusion volume. Other confounders affecting the dynamics of fibrinolysis and transfusion requirement need to be clarified. 相似文献
70.