全文获取类型
收费全文 | 1322篇 |
免费 | 67篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 16篇 |
妇产科学 | 7篇 |
基础医学 | 181篇 |
口腔科学 | 43篇 |
临床医学 | 78篇 |
内科学 | 399篇 |
皮肤病学 | 5篇 |
神经病学 | 83篇 |
特种医学 | 28篇 |
外科学 | 173篇 |
综合类 | 4篇 |
一般理论 | 1篇 |
预防医学 | 86篇 |
眼科学 | 4篇 |
药学 | 150篇 |
中国医学 | 8篇 |
肿瘤学 | 117篇 |
出版年
2023年 | 5篇 |
2022年 | 16篇 |
2021年 | 24篇 |
2020年 | 6篇 |
2019年 | 12篇 |
2018年 | 18篇 |
2017年 | 13篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 26篇 |
2013年 | 28篇 |
2012年 | 47篇 |
2011年 | 85篇 |
2010年 | 30篇 |
2009年 | 32篇 |
2008年 | 80篇 |
2007年 | 77篇 |
2006年 | 67篇 |
2005年 | 68篇 |
2004年 | 77篇 |
2003年 | 56篇 |
2002年 | 89篇 |
2001年 | 49篇 |
2000年 | 46篇 |
1999年 | 43篇 |
1998年 | 19篇 |
1997年 | 19篇 |
1996年 | 8篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1992年 | 17篇 |
1991年 | 14篇 |
1990年 | 32篇 |
1989年 | 17篇 |
1988年 | 27篇 |
1987年 | 25篇 |
1986年 | 24篇 |
1985年 | 17篇 |
1984年 | 18篇 |
1983年 | 16篇 |
1982年 | 8篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1968年 | 5篇 |
排序方式: 共有1399条查询结果,搜索用时 15 毫秒
21.
Kazuo Sugiyama Hideo Hatanaka Tadao Nakaya Minoru Imoto 《Macromolecular chemistry and physics.》1973,165(1):163-171
A study was made of the polymerization of acrylonitrile in dimethylformamide (DMF) initiated by the binary systems of tetramethyltetrazene (TMT) and p-substituted benzyl chlorides. The polymerization rate increased linearly with the σ-constants of substituents as electron-releasing groups were introduced to the phenyl ring of benzyl chloride. In order to elucidate the initiation mechanism of the polymerization, a kinetic investigation was also undertaken of the decomposition of TMT in the presence of p-substituted benzyl chlorides in DMF. The decomposition rate was first-order in TMT and first-order in p-substituents benzyl chloride. The decomposition rate also increased with the σ constants of substituents as electron-releasing groups were introduced. On the basis of the results, the initiation mechanism for the polymerization was discussed. 相似文献
22.
A pore-forming toxin produced by Aeromonas sobria activates Ca2+ dependent Cl- secretion 总被引:1,自引:0,他引:1
Takahashi A Tanoue N Nakano M Hamamoto A Okamoto K Fujii Y Harada N Nakaya Y 《Microbial pathogenesis》2005,38(4):173-180
Bacteria produce many types of hemolysin that induce diarrhea by mechanisms that are not completely understood. Aeromonas sobria hemolysin (ASH) is a major virulence factor produced by A. sobria, a human pathogen that causes diarrhea. Since epithelial cells in the intestine are the primary targets of hemolysin, we investigated the effects of ASH on ion transport in human colonic epithelial (Caco-2) cells. ASH increased short-circuit currents (Isc) in a dose-dependent manner, and it also activated a 125I efflux from Caco-2 cells. ASH-induced Isc increases and 125I efflux activations were both suppressed by low Ca2+ levels in the extracellular solution or by pretreatment with the Ca2+ chlelator BAPTA-AM. Intracellular Ca2+ levels were increased by ASH in a biphasic fashion characterized by a rapid sharp increase (peak 1) followed by a sustained low plateau (peak 2). ASH-induced peak 1 was inhibited by pretreatment with pertussis toxin, indicating that Ca2+ was mobilized from intracellular stores, and peak 2 was induced by an influx of extracellular Ca2+. Peak 2 but not peak 1 was related to Cl- secretion. These results indicate that ASH activates Ca2+-dependent Cl- secretion. 相似文献
23.
M Xu T Aiuchi K Nakaya H Arakawa M Maeda A Tsuji T Kato C Takeshige Y Nakamura 《Neuroscience letters》1990,118(2):205-207
Release of cholecystokinin-like immunoreactivity (CCK-LI) in the medial thalamus of conscious rats was measured by brain dialysis and enzyme immunoassay. Analgesia caused by low-frequency electric stimulation of the tibial muscle, the tsusanli acupuncture point, was judged by change of pain threshold due to the stimulation. Medical thalamic CCK-LI released was increased by peripheral electric stimulations of both the acupuncture point and the non-acupuncture point. Results suggest that CCK acts as a neurotransmitter in the medial thalamus, a part of the analgesia inhibitory system. 相似文献
24.
Wada Takehiko Ishimoto Takuji Nakaya Izaya Kawaguchi Takehiko Sofue Tadashi Shimizu Sayaka Kurita Noriaki Sasaki Sho Nishiwaki Hiroki Koizumi Masahiro Saito Shoji Nishibori Nobuhiro Oe Yuji Yoshida Mai Miyaoka Yoshitaka Akiyama Shin’ichi Itano Yuya Okazaki Masaki Ozeki Takaya Ichikawa Daisuke Oguchi Hideyo Kohsaka Satoshi Kosaka Shiho Kataoka Yuki Shima Hideaki Shirai Sayuri Sugiyama Kazuhiro Suzuki Tomo Son Daisuke Tanaka Tomomi Nango Eishu Niihata Kakuya Nishijima Yoko Nozu Kandai Hasegawa Midori Miyata Rei Yazawa Masahiko Yamamoto Yoshihiro Yamamoto Ryohei Shibagaki Yugo Furuichi Kengo Okada Hirokazu Narita Ichiei 《Clinical and experimental nephrology》2021,25(12):1277-1285
Clinical and Experimental Nephrology - 相似文献
25.
Kosuke Ebina Hideki Tsuboi Yoshio Nagayama Masafumi Kashii Shoichi Kaneshiro Akira Miyama Hiroyuki Nakaya Yasuo Kunugiza Makoto Hirao Gensuke Okamura Yuki Etani Kenji Takami Atsushi Goshima Taihei Miura Ken Nakata Seiji Okada 《Joint, bone, spine : revue du rhumatisme》2021,88(5):105219
ObjectivesTo investigate the effects of prior treatment and determine the predictors of a 12-month treatment response of romosozumab (ROMO) in 148 patients with postmenopausal osteoporosis.MethodsIn this prospective, observational, and multicenter study, treatment naïve patients (Naïve; n = 50) or patients previously treated with bisphosphonates (BP; n = 37) or denosumab (DMAb; n = 45) or teriparatide (TPTD; n = 16) (mean age, 75.0 years; T-scores of the lumbar spine [LS] ?3.2 and total hip [TH] ?2.6) were switched to ROMO due to insufficient effects of prior treatment. Bone mineral density (BMD) and serum bone turnover markers were evaluated for 12 months.ResultsAt 12 months, changes in LS BMD were Naïve (18.2%), BP (10.2%), DMAb (6.4%), and TPTD (11.2%) (P < 0.001 between groups) and changes in TH BMD were Naïve (5.6%), BP (3.3%), DMAb (0.6%), and TPTD (4.4%) (P < 0.01 between groups), respectively. In all groups, the LS BMD significantly increased from baseline at 6 and 12 months, although only the DMAb group failed to obtain a significant increase in TH BMD during 12-month treatment. Mean values of N-terminal type I procollagen propeptide (PINP; μg/L) from baseline → 1 month → 12 months were Naïve (67.9 → 134.1 → 51.0), BP (32. 2 → 81.7 → 40.9), DMAb (30.4 → 56.2 → 75.3), and TPTD (97.4 → 105.1 → 37.1), and those of isoform 5b of tartrate-resistant acid phosphatase (TRACP-5b; mU/dL) were Naïve (500.4 → 283.8 → 267.1), BP (273.4 → 203.1 → 242.0), DMAb (220.3 → 246.1 → 304.8), and TPTD (446.6 → 305.1 → 235.7), respectively. Multiple regression analysis revealed that the significant predictors of BMD change at 12 months were difference of prior treatment (r = ?2.8, P < 0.001) and value of PINP at 1 month (r = 0.04, P < 0.01) for LS, and difference of prior treatment (r = ?1.3, P < 0.05) and percentage change of TRACP-5b at 1 month (r = ?0.06, P < 0.05) for TH.ConclusionsThe early effects of ROMO on LS and TH BMD increase at 12 months were significantly affected by the difference of prior treatment and are predicted by the early change in bone turnover markers. 相似文献
26.
Hiroko Uemura Yukio Hara Masayuki Endou Katsumi Mori Haruaki Nakaya 《Naunyn-Schmiedeberg's archives of pharmacology》1995,353(1):73-79
We have recently reported that class III antiarrhythmic drugs inhibit the muscarinic acetylcholine (ACh) receptor-operated K+ current (I
K, ACh) in guinea-pig atrial cells by different molecular mechanisms. The data obtained from the patch-clamp study suggest that d,l-sotalol inhibits I
K, ACh by blocking the muscarinic receptors, whereas MS-551 inhibits the K+ current by blocking the muscarinic receptors and depressing the function of the K+ channel itself and/or the guanine nucleotide-binding protein (G protein). This study was undertaken to determine whether the class III antiarrhythmic drugs d,l-sotalol and MS-551 interact with the muscarinic receptors of cardiac and peripheral tissues. Both drugs inhibited concentration dependently the specific [3H]N-methylscopolamine ([3H]-NMS) binding to membrane preparations obtained from guinea-pig atria and submandibular glands. The competition curves of these drugs for [3H]-NMS binding to glandular membranes were monophasic, suggesting competition with [3H]-NMS at a single site. Although the competition curve of d,l-sotalol for [3H]-NMS binding to atrial membranes was monophasic, that of MS-551 was biphasic and showed high- and low-affinity states of binding. d,l-Sotalol showed slightly, but significantly, higher affinity for cardiac-type muscarinic receptors (M2) than for glandular-type muscarinic receptors (M3). The inhibition constant (K
i) for MS-551 in glandular membranes was also slightly greater than the high-affinity K
i value for the drug in atrial membranes. In guinea-pig left atria and ilea, d,l-sotalol shifted the concentration-response curves for the negative inotropic effect and the contracting effect of carbachol in a parallel manner. The slopes of Schild plot were not significantly different from unity, suggesting competitive antagonism, and the pA2 for d,l-sotalol in left atria was slightly greater than that in ilea. MS-551 also shifted the concentration response curve for the negative inotropic effect of carbachol in atrial preparations to a greater extent than that for the contracting effect in ileal preparations, although MS-551 failed to show a pure competitive antagonism. These results suggest that both d,l-sotalol and MS-551 interact with cardiac M2 and peripheral M3 receptors, and that at high concentrations they exert anticholinergic activity in cardiac and peripheral tissues. 相似文献
27.
Taurine improves insulin sensitivity in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous type 2 diabetes 总被引:9,自引:0,他引:9
Nakaya Y Minami A Harada N Sakamoto S Niwa Y Ohnaka M 《The American journal of clinical nutrition》2000,71(1):54-58
BACKGROUND: Taurine, a potent antioxidant, has been reported to improve streptozotocin-induced diabetes mellitus, in which the development of diabetes results from an attack by oxygen free radicals on pancreatic beta cells. However, taurine also increases the excretion of cholesterol via conversion to bile acid and would be expected to improve insulin resistance. OBJECTIVE: The effects of taurine on insulin sensitivity were examined in a model rat of insulin resistance and type 2 diabetes-the Otsuka Long-Evans Tokushima Fatty (OLETF) rat. DESIGN: Male OLETF rats were divided into 2 groups at the age of 16 wk: a taurine-supplemented group and an unsupplemented group. As a nondiabetic control, Long-Evans-Tokushima-Otsuka rats were used. An oral-glucose-tolerance test and hyperinsulinemic euglycemic clamp were performed at the ages of 23 and 25 wk. RESULTS: The OLETF rats had hyperglycemia and insulin resistance and they had a greater accumulation of abdominal fat than did control rats. Abdominal fat accumulation, hyperglycemia, and insulin resistance were significantly lower in the taurine-supplemented group than in the unsupplemented group. Serum and liver concentrations of triacylglycerol and cholesterol were significantly higher in the OLETF rats than in the control rats and were significantly lower in the taurine-supplemented group than in the unsupplemented group, presumably because of the increased secretion of cholesterol into bile acid. Taurine-supplemented rats also showed higher nitric oxide secretion, evidenced by increased urinary excretion of nitrite. CONCLUSION: Taurine effectively improves metabolism in OLETF rats by decreasing serum cholesterol and triacylglycerol, presumably via increased secretion of cholesterol into bile acid and decreased production of cholesterol because of increased nitric oxide production. 相似文献
28.
Pure red cell aplasia and myasthenia gravis with thymoma: a case report and review of the literature 总被引:3,自引:0,他引:3
Mizobuchi S; Yamashiro T; Nonami Y; Yamamoto A; Kume M; Nakaya H; Sawada T; Taguchi H; Moriki T; Ogoshi S 《Japanese journal of clinical oncology》1998,28(11):696-701
A case of pure red cell aplasia (PRCA), myasthenia gravis (MG) and thymoma
is reported. A 70-year-old woman presented with severe anemia. She had been
diagnosed as having MG 8 years earlier and her symptoms were adequately
controlled with ambenonium chloride. When she visited our hospital, her
hematocrit was 13.7% with a hemoglobin concentration of 4.7 g/dl and her
reticulocyte counts were persistently abnormal at 0.1%. Although both
direct and indirect Coombs' tests were positive, there was no evidence of
hemolysis. Routine screening tests for other etiologies of anemia were
negative. Serological tests for anti-DNA and anti-acetylcholine receptor
antibodies gave positive results. A bone marrow examination revealed severe
erythroid hypoplasia. PRCA was diagnosed and the patient was treated with
periodic transfusions. A lateral view chest roentgenogram and a computed
tomography scan of the thorax showed the presence of an anterior
mediastinal mass which was suspected to be thymoma. The patient underwent
thymothymectomy and the tumor was diagnosed as a thymoma. Although the
patient received no treatment for MG and PRCA after surgery, her
hematological test results rapidly improved and she was discharged from the
hospital on the 29th postoperative day. At that time, her hematocrit was
33.2%, her hemoglobin concentration was 10.0 g/dl, her peripheral
reticulocyte level was 1.8% and her left partial ptosis had improved. She
is doing well, 9 months after surgery. For a patient to remain in remission
without treatment for PRCA and MG after thymothymectomy is extremely rare.
相似文献
29.
D Nishi Y Koido N Nakaya T Sone H Noguchi K Hamazaki T Hamazaki Y Matsuoka 《Psychotherapy and psychosomatics》2012,81(5):315-317
No abstract available. 相似文献
30.