全文获取类型
收费全文 | 4789篇 |
免费 | 175篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 66篇 |
妇产科学 | 36篇 |
基础医学 | 656篇 |
口腔科学 | 90篇 |
临床医学 | 246篇 |
内科学 | 1329篇 |
皮肤病学 | 69篇 |
神经病学 | 462篇 |
特种医学 | 131篇 |
外科学 | 807篇 |
综合类 | 24篇 |
预防医学 | 123篇 |
眼科学 | 103篇 |
药学 | 283篇 |
中国医学 | 25篇 |
肿瘤学 | 493篇 |
出版年
2023年 | 25篇 |
2022年 | 46篇 |
2021年 | 64篇 |
2020年 | 45篇 |
2019年 | 82篇 |
2018年 | 96篇 |
2017年 | 80篇 |
2016年 | 77篇 |
2015年 | 87篇 |
2014年 | 136篇 |
2013年 | 158篇 |
2012年 | 268篇 |
2011年 | 298篇 |
2010年 | 168篇 |
2009年 | 128篇 |
2008年 | 263篇 |
2007年 | 324篇 |
2006年 | 270篇 |
2005年 | 278篇 |
2004年 | 297篇 |
2003年 | 253篇 |
2002年 | 247篇 |
2001年 | 82篇 |
2000年 | 72篇 |
1999年 | 95篇 |
1998年 | 66篇 |
1997年 | 45篇 |
1996年 | 43篇 |
1995年 | 40篇 |
1994年 | 48篇 |
1993年 | 46篇 |
1992年 | 64篇 |
1991年 | 66篇 |
1990年 | 51篇 |
1989年 | 53篇 |
1988年 | 49篇 |
1987年 | 43篇 |
1986年 | 46篇 |
1985年 | 38篇 |
1984年 | 23篇 |
1983年 | 30篇 |
1982年 | 24篇 |
1981年 | 20篇 |
1980年 | 18篇 |
1979年 | 35篇 |
1978年 | 28篇 |
1973年 | 18篇 |
1972年 | 15篇 |
1969年 | 16篇 |
1968年 | 14篇 |
排序方式: 共有4994条查询结果,搜索用时 15 毫秒
51.
Osamu Kawashima Mitsuru Ohata Kazuhiko Sakamoto Kenichi Hashimoto Hisato Nakajima Masayoshi Yamauchi 《Nihon Arukōru Yakubutsu Igakkai zasshi》2003,38(1):58-68
Gender difference of alcohol intake and laboratory data was investigated in 165 Japanese patients with alcoholic liver cirrhosis. Mean age of first drinking and habitual drinking were higher in female. Duration of drinking was shorter in female. Although cumulative alcohol intake was larger in male, mean daily alcohol intake did not differ in both gender. Moreover, daily alcohol intake adjusted to body weight was significantly larger in female. Body mass index, serum levels of total protein, albumin and cholinesterase were significantly decreased in female. Platelet counts on admission did not differ in both gender. However, it was significantly increased in female after one month abstinence. C reactive protein, ammonia and serum levels of total bilirubin were significantly higher in female as compared to male. In conclusion, female alcoholics seems to progress to liver cirrhosis earlier because of high daily alcohol intake adjusted to body weight, poor nutritional condition and inflammation caused by endotoxin. 相似文献
52.
Bin Zhang Andrei Ougolkov Kaname Yamashita Yutaka Takahashi Masayoshi Mai Toshinari Minamoto 《Clinical cancer research》2003,9(8):3073-3079
PURPOSE AND STUDY DESIGN: Recent studies have shown that beta-catenin translocated into the cell nucleus functions like an oncogene. Accumulating evidence suggests that activation of the beta-catenin oncogenic signaling cascade along with its twin, the K-ras cascade, may exert syngeneic or synergistic effects on tumor development and progression. In the study reported here, we analyzed oncogenic beta-catenin activation on the basis of its nuclear accumulation (NA) and compared the results with those of mutational activation of K-ras in 74 patients with colorectal cancer to determine whether the two oncogene-mediated signaling cascades interact. RESULTS: We found two distinct patterns of beta-catenin activation, i.e., diffuse NA in 20 cases (27%) and selective NA at the tumor invasion front (NAinv) in 19 cases (26%). The presence of the NAinv pattern was significantly correlated with advanced Dukes' stage tumor (P = 0.0005) and the presence of distant metastases (P = 0.0064). K-ras proto-oncogene was mutated in the tumors of 31 cases (42%). Activated beta-catenin or K-ras was detected in most (78%) colorectal cancers analyzed, although a weak inverse correlation was found between the activities of the two oncogenes in the tumors. Importantly, most (7 of 8) patients with tumor showing both K-ras activation and the NAinv pattern of beta-catenin activation were in Dukes' stage C at surgery, and half of them developed distant metastases to the liver and lungs. CONCLUSION: The results suggest that although oncogenic activation of beta-catenin and K-ras is independent in the process of clinical cancer development, combined analysis of the two major oncogenes can detect most colorectal cancers and identify a subset of patients with poorer outcomes. Consequently, activation of either or both of these oncogenes may serve as a genetic marker for molecular diagnosis. 相似文献
53.
Subependymoma of the septum pellucidum: Characterization by PET 总被引:1,自引:0,他引:1
Mineura Katsuyoshi Shioya Hitoshi Kowada Masayoshi Ogawa Toshihide Hatazawa Jun Uemura Kazuo 《Journal of neuro-oncology》1997,32(2):143-147
We report the evaluation of a subependymoma of the septum pellucidum by positron emission tomography (PET) with analysis of 18F-fluorodeoxyglucose (FDG)kinetics. The tumor showed exceedingly low rates of glucose metabolism (rCMRG1) and kinetic constants (K1, K2, and K3). This hypometabolism indicates low cellular density and slow growth. 相似文献
54.
Hidehiro Nomura Yutaka Takahashi Masayoshi Mai 《International journal of clinical oncology / Japan Society of Clinical Oncology》1998,3(2):117-120
A 53-year-old woman had shown repeated, partial responses to chemotherapy for large, multiple liver metastases of sigmoid
colon cancer. After a partial response to 5-fluorouracil plus leucovorin therapy, an 89.7% reduction of the 5-fluorouracil-resistant
metastatic tumor was achieved by giving CPT-11 (irinotecan) at a dose of 100 mg/body per week. We suggest that CPT-11 should
be recommended as an effective second-line treatment for unresectable liver metastases of colon cancer, after 5-fluorouracil-based
chemotherapy. 相似文献
55.
56.
目的:合成天然产物taxinine NN-3和taxinine NN-14,研究其对肿瘤细胞的多药耐药逆转活性.方法:以紫杉宁为出发原料,通过选择性水解9,10位的乙酰氧基,制成原乙酸酯后再水解.结果:以紫杉宁为原料经过3步反应,可以同时获得taxinine NN-3,taxinine NN-4两种天然产物,其中taxinine NN-3的收率为25%,taxinineNN-4的收率为68%.结论:高收率地合成了taxinine NN-3和taxinine NN-14. 相似文献
57.
Kazumasa Miki Masao Ichinose Norio Kawamura Masashi Matsushima Haron Bin Ahmad Masayoshi Kimura Junjiro Sano Takao Tashiro Nobuyuki Kakei Hiroshi Oka Chie Furihata Kenji Takahashi 《Cancer science》1989,80(2):111-114
Serum pepsinogen levels were measured in 137 stomach cancer patients and compared with those of 288 normal cancer-free subjects. The serum pepsinogen levels of stomach cancer patients, especially pepsinogen I and the pepsinogen I/pepsinogen II ratio were significantly lower than those of normal controls and correlated well with the extent of chronic gastritis associated with the cancerous stomach. These results were in good accordance with the results of previous studies indicating that the cancer derived from the stomach where chronic gastritis/intestinal metaplasia is extensive. The high sensitivity and specificity of this non-invasive serum test to detect chronic gastritis suggested the possibility of its application to the mass screening of stomach cancer. 相似文献
58.
Bonpei Takase Katsumi Hayashi Satoko Takei Tetsuya Hisada Nobuyuki Masaki Masayoshi Nagata 《Internal medicine (Tokyo, Japan)》2022,61(14):2167
Coronavirus disease 2019 (COVID-19) has become a pandemic, and vaccines remain the only effective tools available for ending it. However, their side effects, such as syncope, which mimics sudden cardiac death, are serious concerns. We herein report 6 cases of delayed vasovagal syncope and presyncope (VVR) caused by COVID-19 vaccination among 25,530 COVID-19 patients. The prevalence of delayed VVR due to COVID-19 vaccination was 0.026%. In addition, no delayed VVR was found among 17,386 patients who received the influenza vaccine. Delayed VVR is likely to be overlooked if medical staff are not aware of this symptom. This report provides significant information regarding effects of COVID-19 vaccination. 相似文献
59.
Yoshii M Nishizaki T Watabe S 《Nihon yakurigaku zasshi. Folia pharmacologica Japonica》1998,112(Z1):41P-43P
Nootropics are proposed to serve as cognition enhancers. The underlying mechanism, however, is largely unknown. We have attempted to assess the intracellular signal transduction pathways mediating the action of nefiracetam, a nootropic agent, on neuronal Ca2+ channels and nicotinic ACh receptors. In NG108-15 cells, nefiracetam (1 microM) enhanced the activities of N/L-type Ca2+ channels without affecting T-type The nefiracetam action was mimicked by dibutyryl cAMP (1 mM), or blocked by pertussis toxin (PTX), indicating that PTX-sensitive inhibitory G-proteins and cAMP-dependent pathways mediate the drug action. Nefiracetam also exerted a dose-dependent biphasic effect on Torpedo nicotinic acetylcholine (nACh) receptors expressed in Xenopus oocytes, in which the drug induced a short-term depression of ACh-evoked currents at submicromolar concentrations (0.01-0.1 microM) and a long-term enhancement of the currents at micromolar concentrations (1-10 microM). The depression was caused by activation of PTX-sensitive G-protein-regulated cAMP-dependent protein kinase (PKA) with subsequent phosphorylation of the ACh receptors; in contrast, the enhancement was caused by activation of Ca(2+)-dependent protein kinase C (PKC) and the ensuing PKC phosphorylation of the receptors. It is concluded that nefiracetam interacts with PKA and PKC pathways, which may explain a cellular mechanism for the action of cognitive enhancers. 相似文献
60.
Khaleque Newaz Khan MD Keisuke Nakata MD Masayoshi Shima MD Yukio Kusumoto MD Nobuko Ishii MD toshihiko Koji MD Dr. Shigenobu Nagataki MD 《Digestive diseases and sciences》1993,38(1):65-70
We analyzed the serial changes in serum pancreatic enzyme activities by transcatheter arterial embolization (TAE) in 20 hepatoma patients with liver cirrhosis in an attempt to evaluate the incidence of the pancreatic tissue damage by TAE. Serum amylase activities increased in two (10%) cases, elastase 1 levels in six (30%) cases, and trypsin and pancreatic secretory trypsin inhibitor (PSTI) levels in each of five (25%) cases. Consequently, TAE resulted in the elevation of at least more than one serum pancreatic enzyme in eitht (40%) of 20 cases, although none had clinical symptoms related to pancreatitis When the adverse effect on the pancreatic tissue was compared among 6 cases of the superselective TAE and 14 cases of the nonsuperselective TAE, which were perfomed from the segmental and the nonsegmental hepatic arteries, respectively, the elevation of serum pancreatic enzymes was caused only by nonsuperselective TAE, not by superselective TAE. The volumes of Spongel and lipiodol used or the injected doses of the anticancer agent mitomycin C were not different between the two groups. These results indicate that TAE for the treatment of hepatoma frequently causes pancreatic tissue damage, and the position of the inserted catheter tip is very important to avoid the pancreatic tissue damage by TAE. 相似文献