全文获取类型
收费全文 | 5067篇 |
免费 | 198篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 61篇 |
妇产科学 | 29篇 |
基础医学 | 582篇 |
口腔科学 | 81篇 |
临床医学 | 263篇 |
内科学 | 1216篇 |
皮肤病学 | 59篇 |
神经病学 | 274篇 |
特种医学 | 252篇 |
外科学 | 1005篇 |
综合类 | 21篇 |
预防医学 | 170篇 |
眼科学 | 126篇 |
药学 | 334篇 |
中国医学 | 9篇 |
肿瘤学 | 760篇 |
出版年
2023年 | 27篇 |
2022年 | 68篇 |
2021年 | 161篇 |
2020年 | 62篇 |
2019年 | 79篇 |
2018年 | 105篇 |
2017年 | 77篇 |
2016年 | 122篇 |
2015年 | 116篇 |
2014年 | 166篇 |
2013年 | 224篇 |
2012年 | 344篇 |
2011年 | 344篇 |
2010年 | 210篇 |
2009年 | 181篇 |
2008年 | 298篇 |
2007年 | 354篇 |
2006年 | 300篇 |
2005年 | 302篇 |
2004年 | 337篇 |
2003年 | 333篇 |
2002年 | 310篇 |
2001年 | 64篇 |
2000年 | 63篇 |
1999年 | 61篇 |
1998年 | 80篇 |
1997年 | 73篇 |
1996年 | 61篇 |
1995年 | 44篇 |
1994年 | 37篇 |
1993年 | 33篇 |
1992年 | 37篇 |
1991年 | 27篇 |
1990年 | 26篇 |
1989年 | 13篇 |
1988年 | 12篇 |
1987年 | 25篇 |
1986年 | 11篇 |
1985年 | 19篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1978年 | 3篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1964年 | 2篇 |
排序方式: 共有5288条查询结果,搜索用时 15 毫秒
91.
Lewis Blood Group-Related Antigen Expression in Normal Gastric Epithelium, Intestinal Metaplasia, Gastric Adenoma, and Gastric Carcinoma 总被引:6,自引:0,他引:6
Kenji Kobayashi M.D. Junichi Sakamoto M.D. Tsuyoshi Kito M.D. Yoshitaka Yamamura M.D. Takashi Koshikawa M.D. Miyuki Fujita Tadashi Watanabe M.D. Hiroaki Nakazato M.D. 《The American journal of gastroenterology》1993,88(6):919-924
The expression of blood group-related antigens of the Lewis system in normal gastric mucosa, intestinal metaplasia, gastric adenoma, and gastric carcinoma was examined. Ninety-five percent of normal foveolar epithelial samples stained positive for Lewisb antigen, whereas only 10.0% expressed Lewisa antigen. In contrast, intestinal metaplasia specimens had increased Lewisa antigen expression and slightly decreased Lewisb antigen expression. A similar pattern of Lewisa and Lewisb expression was observed in gastric adenomas and intestinal type adenocarcinomas. Lewisx and Lewisy were detected in all normal deep glands, but were not expressed in the majority of intestinal metaplasia specimens. In addition, only 20–40% of gastric adenomas and gastric carcinomas expressed Lewisx and Lewisy antigens. These changes in Lewis antigen expression in intestinal metaplasia, adenomas, and intestinal type adenocarcinomas suggest that altered expression of Lewis blood group-related antigens may correlate with cell transformation processes. 相似文献
92.
Koba S Hirano T Murayama S Kotani T Tsunoda F Iso Y Ban Y Kondo T Suzuki H Katagiri T 《Atherosclerosis》2003,170(1):131-140
BACKGROUND: The small dense low-density lipoprotein (LDL) phenotype (pattern B), high concentrations of remnant-like particles (RLPs), and postprandial lipemia are newly recognized risk factors for coronary heart disease (CHD). However, the associations of these lipoprotein abnormalities remain unclear. The aim of this study was to investigate the relationships among LDL phenotype, very-low-density lipoprotein (VLDL) subclasses, and postprandial lipoprotein metabolism in CHD patients. METHOD: We performed an oral fat tolerance test in 32 patients with acute myocardial infarction and compared the following parameters between patients characterized by either large buoyant LDL (pattern A) versus pattern B: lipids and apolipoproteins (apo) in the plasma and Svedberg flotation rates (Sf) >400 (chylomicron), Sf 60-400 (large VLDL), and Sf 20-60 (small VLDL) fractions. RESULT: Fasting levels of triglyceride, RLP-cholesterol and RLP-triglyceride were slightly higher in the pattern B patients. Postprandial increases of RLP-cholesterol and the cholesterol and triglyceride of large VLDL fractions were significantly greater in the pattern B patients. The areas under the curves of cholesterol, triglyceride, and apo-B in large VLDL fractions were significantly higher in pattern B, while those in small VLDL were not. RLP-cholesterol and RLP-triglyceride in fasting and fed states correlated very highly with the corresponding cholesterol and triglyceride concentrations in large VLDL fractions. CONCLUSION: These results suggest that postprandial increase of large VLDL fractions and RLPs contribute to the formation of small dense LDL in CHD patients. 相似文献
93.
Shigemoto Yoko Matsuda Hiroshi Kimura Yukio Chiba Emiko Ohnishi Masahiro Nakaya Moto Maikusa Norihide Ogawa Masayo Mukai Yohei Takahashi Yuji Sako Kazuya Toyama Hiroshi Inui Yoshitaka Taki Yasuyuki Nagayama Hiroshi Ono Kenjiro Kono Atsushi Sekiguchi Kenji Hirano Shigeki Sato Noriko 《Annals of nuclear medicine》2022,36(5):460-467
Annals of Nuclear Medicine - Although previous studies have investigated age and gender effects on striatal subregional dopamine transporter (DaT) binding, these studies were mostly based on a... 相似文献
94.
Cough variant asthma is known as a major cause of chronic cough. Fundamental features of cough variant asthma are prolonged nonproductive cough responding to bronchodilator therapy, no history of wheezing or dyspnea attack, normal cough sensitivity, and slightly increased bronchial responsiveness. Animal model of cough variant asthma has not been reported. The aim of this study was to establish an animal model for studying detailed pathophysiology of cough variant asthma. Bronchial responsiveness to methacholine and cough reflex sensitivity to capsaicin were measured 72 hours after antigen (ovalbumin, OA) inhalation in actively sensitized guinea pigs. Next, cough number and specific airway resistance (sRaw) were measured during 20 minutes following reinhalation of OA solution, which was carried out 72 hours after the first OA inhalation, and then total cell number and cell differentials in bronchoalveolar lavage fluid (BALE) were measured. Bronchial responsiveness to methacholine, but not cough reflex sensitivity to capsaicin, was significantly increased 72 hours after the first inhalation of OA solution. Number of coughs, sRaw and total cell number in BALF increased significantly by the OA reinhalation, and the cough number and the increase in sRaw were significantly suppressed by beta2 agonist, procaterol. FK224, a specific neurokinin (NK) receptor antagonist, did not significantly influence the OA reinhalation-induced cough and increase in sRaw and total cell number in BALF in this model In conclusion, pathophysiologic feature of this animal model is similar to that of clinical cough variant asthma. Tachykinins may not play an important part in antigen-induced cough associated with bronchoconstriction and airway inflammation in cough variant asthma. 相似文献
95.
Yoshitaka Morimatsu Hiroya Akiyoshi Hisamichi Aizawa 《Kansenshōgaku zasshi. The Journal of the Japanese Association for Infectious Diseases》2003,77(3):174-177
We report a case of septicemia type Vibrio vulnificus infection. The patient was a 74-year-old man who had liver cirrhosis and hepatocelluler carcinoma. He felt a pain in the right femoral lesion after eating raw shellfish (Japanese "Umitake") two days ago. He was admitted to our emergency center due to his shock status and thrombocytopenia two days after the onset. We diagnosed necrotizing fasciitis due to Vibrio vulnificus infection, his life was saved by emergency amputation of the right lower extremity. The culture of the blood and vesicle fluid showed Vibrio vulnificus. There are some reports that the debridement was effective to necrotizing fasciitis due to Vibrio vulnificus infection, but these reports are all about single upper extremity lesion. As far as we know, this is the second report of lower extremity necrotiaong fasciitis due to septicemia type Vibrio vulnificus infection rescued by extremity amputation in Japan. The mortality of septicemia type Vibrio vulnificus infection with necrotizing fasciitis is very high, this is quite a valuable report in making a decision for therapy of septicemia type Vibrio vulnificus infection. 相似文献
96.
Takagi S Kinouchi Y Chida M Hiwatashi N Noguchi M Takahashi S Shimosegawa T 《Digestive diseases and sciences》2003,48(10):2091-2094
Telomerase acitivity can be induced in human B lymphocytes by in vitro stimulation of their antigen receptors. To determine whether telomerase activity is induced in vivo, we analyzed telomerase activity in B lymphocytes from the mesenteric lymph nodes of patients with inflammatory bowel disease (IBD), whose lymph nodes are well known to be strongly stimulated, and from those of noninflamed controls. Seven IBD patients and 4 noninflamed controls were enrolled. Telomerase activity was assayed by telomeric repeat amplification protocol with minor modifications. The mesenteric lymph nodes from patients with IBD had stronger telomerase activity than those from controls or peripheral mononuclear cells. Isolation of CD19+ B lymphocytes from these lymph nodes showed that this strong activity resides in this lymphocytes subpopulation. This study provides the evidence that telomerase activity is induced in human B lymphocytes in human inflammatory disease. 相似文献
97.
Yoshitaka T Abe N Minagawa H Date H Sakoma Y Nishida K Ozaki T 《Modern rheumatology / the Japan Rheumatism Association》2008,18(4):359-365
We prospectively evaluated the disease-specific features of the early postoperative plasma D: -dimer value and the relationship with deep venous thrombosis and/or pulmonary thromboembolism (DVT/PE) in 95 patients following total knee arthroplasty. Patients in whom DVT/PE was highly suspected were diagnosed by high-resolution multi-detector row computed tomography scanning (MDCT). Forty-nine knees in 46 patients with rheumatoid arthritis (RA, 24 knees) or osteoarthritis (OA, 25 knees) were finally recruited. DVT/PE was detected in 28 (57.1%) of the 49 cases examined by diagnostic MDCT: 12 (50.0%) of the 24 cases of RA, and 16 (64.0%) of the 25 cases of OA. Of these, PE was found in 11 cases (39.2%), but none of them showed clinical symptomatic signs of dyspnea or chest pain. In both RA and OA cases, there were statistically significant differences in the D: -dimer value on postoperative day 3 (P = 0.027) and after day 28 (P = 0.037) between the groups with and without DVT/PE. In OA cases, there were significant differences between the two groups on postoperative days 1 (P = 0.034), 3 (P = 0.020), 5 (P = 0.005), and 7 (P = 0.045), respectively. At the baseline, perioperative D: -dimer levels in the RA group without DVT/PE were higher than in the OA group. However, multivariate logistic regression analysis showed that RA was not a significant risk factor of DVT/PE in comparison with OA. In conclusion, individual evaluation of the D: -dimer level between RA and OA should provide a more precise predictive indicator of early postoperative DVT/PE. 相似文献
98.
Karni R Hippo Y Lowe SW Krainer AR 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(40):15323-15327
The splicing factor SF2/ASF is an oncoprotein that is up-regulated in many cancers and can transform immortal rodent fibroblasts when slightly overexpressed. The mTOR signaling pathway is activated in many cancers, and pharmacological blockers of this pathway are in clinical trials as anticancer drugs. We examined the activity of the mTOR pathway in cells transformed by SF2/ASF and found that this splicing factor activates the mTORC1 branch of the pathway, as measured by S6K and eIF4EBP1 phosphorylation. This activation is specific to mTORC1 because no activation of Akt, an mTORC2 substrate, was detected. mTORC1 activation by SF2/ASF bypasses upstream PI3K/Akt signaling and is essential for SF2/ASF-mediated transformation, as inhibition of mTOR by rapamycin blocked transformation by SF2/ASF in vitro and in vivo. Moreover, shRNA-mediated knockdown of mTOR, or of the specific mTORC1 and mTORC2 components Raptor and Rictor, abolished the tumorigenic potential of cells overexpressing SF2/ASF. These results suggest that clinical tumors with SF2/ASF up-regulation could be especially sensitive to mTOR inhibitors. 相似文献
99.
Yoshitaka Okamoto Daisuke Ishii Satoshi Yamamoto Kiyoshige Ishibashi Masahiro Wakatabi Yutaka Kohno Kenji Numata 《Journal of stroke and cerebrovascular diseases》2021,30(8):105889
ObjectivesWe investigated the relationship between pyramidal tract evaluation indexes (i.e., diffusion tensor imaging, transcranial magnetic stimulation (TMS)-induced motor-evoked potential (MEP), and central motor conduction time (CMCT) on admission to the recovery rehabilitation unit) and motor functions at discharge in patients with ischemic or hemorrhagic stroke.Materials and MethodsSeventeen patients were recruited (12 men; 57.9 ± 10.3 years). The mean fractional anisotropy (FA) values of the right and left posterior limbs of the internal capsule were estimated using a computer-automated method. We determined the ratios of FA values in the affected and unaffected hemispheres (rFA), TMS-induced MEP, and the ratios of CMCT in the affected and unaffected hemispheres (rCMCT) and examined their association with motor functions (Fugl–Meyer Assessment (FMA) and Action Research Arm Test (ARAT)) at discharge.ResultsHigher rFA values of the posterior limb of the internal capsule on admission to the recovery rehabilitation unit led to a better recovery of upper limb function (FMA: r = 0.78, p < 0.001; ARAT: r = 0.74, p = 0.001). Patients without MEP had poorer recovery of upper limb function than those with MEP (FMA: p < 0.001; ARAT: p = 0.001). The higher the rCMCT, the poorer the recovery of upper limb function (ARAT: r = ?0.93, p < 0.001). However, no association was observed between the pyramidal tract evaluation indexes and recovery of lower limb motor function.ConclusionsEvaluating the pyramidal tract is useful for predicting upper limb function prognosis, but not for lower limb function prognosis. 相似文献
100.
Takeshi Imamura Keiko Ogami-Takamura Kazunobu Saiki Ayami Hamamoto Daisuke Endo Kiyohito Murai Keita Nishi Junya Sakamoto Keishi Okamoto Joichi Oyamada Yoshitaka Manabe Toshiyuki Tsurumoto 《Journal of anatomy》2021,239(1):46-58
The diaphysis of the human femoral bone has a physiological anterior curvature; additionally, there is a curvature to the medial side or lateral side. In addition to compression stress from gravity during standing, walking, and running, these bones are continuously exposed to complex stresses from the traction forces of the various strong muscles attached to them. The femoral diaphysis is subjected to these mechanical stresses, and the direction and size of its curvature are defined according to Wolff's law and the mechanostat theory of Frost. The purpose of this study was to quantitatively evaluate the curvature of the femoral diaphysis in Japanese skeletons by determining the curve connecting the central mass distributions (CMD) of cross-sectional images. A total of 90 right femora (46 males and 44 females) were randomly selected from modern Japanese skeletal specimens. Full-length images of these bones were acquired using a clinical computed tomography scanner. The range between the lower end of the lesser trochanter and the adductor tubercle of each femur was divided at regular intervals to obtain ten planes, and nine levels were analyzed. The CMD curve was determined by connecting the CMDs of each of the nine cross-sections. First, the CMD of a cross-section in each of the nine slices was calculated, and the nine trajectories were superimposed from above. Then, by converting the shape of the entire CMD curve to superimpose the coordinates of the endpoint on the starting point, a closed arc representing the curvature of the femur was determined. For both males and females, the patterns varied from mostly medial to largely lateral curvature. The size of the curvature also varied for individuals. By analyzing only the coordinates of the vertex of the CMD curve of each femoral bone, the outlines of the diaphyseal curvatures could be recognized. The femora were thereby divided into two groups: medial bending and lateral bending. Considering males and females together, the number in the lateral-curvature group (n = 51) was larger than that in the medial-curvature group (n = 39). Moreover, the average age of the lateral-curvature group was significantly higher than that of the medial-curvature group (p < 0.05). In males, with an increase in the cortical bone proportion of the cross-sectional area, the anterior vertex of diaphyseal bending tended to be more prominent. This cortical proportion was significantly higher in the medial-curvature groups than in the lateral-curvature group (p < 0.01). The phenomena observed in this study may be related to pathophysiologies such as atypical fractures of the femur and osteoarthritis of the knee joints. 相似文献