全文获取类型
收费全文 | 8824篇 |
免费 | 473篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 197篇 |
妇产科学 | 169篇 |
基础医学 | 1202篇 |
口腔科学 | 185篇 |
临床医学 | 559篇 |
内科学 | 2215篇 |
皮肤病学 | 225篇 |
神经病学 | 594篇 |
特种医学 | 341篇 |
外科学 | 1581篇 |
综合类 | 26篇 |
一般理论 | 2篇 |
预防医学 | 240篇 |
眼科学 | 85篇 |
药学 | 516篇 |
中国医学 | 14篇 |
肿瘤学 | 1141篇 |
出版年
2023年 | 78篇 |
2022年 | 141篇 |
2021年 | 219篇 |
2020年 | 110篇 |
2019年 | 148篇 |
2018年 | 191篇 |
2017年 | 159篇 |
2016年 | 194篇 |
2015年 | 200篇 |
2014年 | 226篇 |
2013年 | 305篇 |
2012年 | 527篇 |
2011年 | 564篇 |
2010年 | 301篇 |
2009年 | 288篇 |
2008年 | 522篇 |
2007年 | 513篇 |
2006年 | 552篇 |
2005年 | 490篇 |
2004年 | 515篇 |
2003年 | 480篇 |
2002年 | 471篇 |
2001年 | 182篇 |
2000年 | 175篇 |
1999年 | 171篇 |
1998年 | 118篇 |
1997年 | 102篇 |
1996年 | 95篇 |
1995年 | 73篇 |
1994年 | 71篇 |
1993年 | 69篇 |
1992年 | 98篇 |
1991年 | 120篇 |
1990年 | 114篇 |
1989年 | 111篇 |
1988年 | 72篇 |
1987年 | 68篇 |
1986年 | 61篇 |
1985年 | 61篇 |
1984年 | 49篇 |
1983年 | 38篇 |
1982年 | 21篇 |
1981年 | 18篇 |
1979年 | 34篇 |
1978年 | 28篇 |
1977年 | 19篇 |
1975年 | 17篇 |
1974年 | 16篇 |
1970年 | 15篇 |
1969年 | 23篇 |
排序方式: 共有9340条查询结果,搜索用时 15 毫秒
151.
NAD(P)H oxidase plays a crucial role in PDGF-induced proliferation of hepatic stellate cells 总被引:13,自引:0,他引:13
Adachi T Togashi H Suzuki A Kasai S Ito J Sugahara K Kawata S 《Hepatology (Baltimore, Md.)》2005,41(6):1272-1281
The proliferation of hepatic stellate cells (HSCs) is a critical step in hepatic fibrogenesis. Platelet-derived growth factor (PDGF) is the most potent mitogen for HSCs. We investigated the role of nonphagocytic NAD(P)H oxidase-derived reactive oxygen species (ROS) in PDGF-induced HSC proliferation. The human HSC line, LI-90 cells, murine primary-cultured HSCs, and PDGF-BB were used in this study. We examined the mechanism of PDGF-BB-induced HSC proliferation in relation to the role of a ROS scavenger and diphenylene iodonium, an inhibitor of NAD(P)H oxidase. We also measured ROS production with the aid of chemiluminescence. We showed that PDGF-BB induced proliferation of HSCs through the intracellular production of ROS. We also demonstrated that HSCs expressed key components of nonphagocytic NAD(P)H oxidase (p22phox, gp91phox, p47phox, and p67phox) at both the messenger RNA and protein levels. Diphenylene iodonium suppressed PDGF-BB-induced ROS production and HSC proliferation. Coincubation of H2O2 and PDGF-BB restored the proliferation of HSCs that was inhibited by diphenylene iodonium pretreatment. Phosphorylation of the mitogen-activated protein kinase (MAPK) family constitutes a signal transduction pathway of cell proliferation. Our data demonstrate that NAD(P)H oxidase-derived ROS induce HSC proliferation mainly through the phosphorylation of p38 MAPK. Moreover, an in vivo hepatic fibrosis model also supported the critical role of NAD(P)H oxidase in the activation and proliferation of HSCs. In conclusion, NAD(P)H oxidase is expressed in HSCs and produces ROS via activation of NAD(P)H oxidase in response to PDGF-BB. ROS further induce HSC proliferation through the phosphorylation of p38 MAPK. 相似文献
152.
153.
Naoto Komada Minako Yamagata Kazutaka Komura Katsuhiro Hayashi Toshihiro Maruyama Hiroaki Kataoka Masashi Koono Hirohito Tsubouchi 《Journal of gastroenterology》1997,32(1):95-101
We report an autopsy case of hepatocellular carcinoma (HCC) with sarcomatous change arising in the context of primary biliary cirrhosis (PBC) in a 79-year-old man. Primary biliary cirrhosis was diagnosed (stage I according to Scheuer's classification) by findings on blood biochemical analysis, laparoscopy, and liver biopsy at age 69 years. Five years later, (at age 74 years), a mass lesion was detected in the S6 region of the liver by abdominal ultrasonography, and target biopsy revealed well differentiated HCC. Blood biochemistry, ultrasonography, and computed tomography findings showed that the PBC had progressed to stage IV (cirrhotic stage). Percutaneous ethanol injection therapy (PEIT) was administered to the HCC several times over a 5-year period; however, the patient died of liver failure in February, 1994 (at age 79 years). Viral markers for hepatitis B and C were negative during the course, and hepatitis C virus RNA was not detected by polymerase chain reaction. Autopsy findings showed liver cirrhosis and diffuse involvement of spindle-shaped sarcomatoid cells in the liver, particularly in the S6 region, associated with several nodules of trabecular HCC cells. A zone of transition between the sarcomatoid cells and the trabecular hepatocellular carcinoma cells was observed. The sarcomatoid cells were diffusely disseminated in the peritoneal cavity and had metastasized to multiple organs. Immunohistochemically, the cells were positive for fibrinogen, as were the coexisting trabecular hepatocellular carcinoma cells. The HCC had been treated several times with PEIT. Of interest, PEIT may be an important factor in this type of tumor progression. 相似文献
154.
155.
Yoshisato Tanimoto Hirotaka Tashiro Toshiyuki Itamoto Naoyuki Toyota Toshihiko Kohashi Hironobu Amano Hideki Ohdan Kohei Ishiyama Akihiko Oshita Toshimasa Asahara 《Journal of hepato-biliary-pancreatic sciences》2008,15(2):228-231
Hepatic venous outflow obstruction is a relatively uncommon but important and devastating complication occurring after liver transplantation. Recently, right lateral sector liver grafts have sometimes been used in living-donor liver transplantation (LDLT), but, to our knowledge, early hepatic venous outflow obstruction has never been reported in right lateral sector LDLT. A 58-year-old woman was diagnosed with liver cirrhosis and hepatocellular carcinoma and underwent right lateral sector LDLT. Postoperatively, she developed liver dysfunction. Doppler ultrasound examination revealed flat waveforms and low-flow velocity in the right hepatic vein (RHV). A computed tomography (CT) scan revealed a ventrally distorted RHV due to hypertrophy of the liver graft. Hepatic venous obstruction was suspected and a hepatic venogram was performed. The venogram revealed stenosis of the RHV due to the distortion of the vein. We performed percutaneous transfemoral balloon dilatation, but this was not effective. We then inserted an expandable metallic stent (EMS) into the RHV. After the EMS placement, the condition of the patient improved. Venogram and CT data suggested that the obstruction of the RHV developed because of distortion of the RHV to the ventral side during liver regeneration. 相似文献
156.
Masaru Nakayama Haruki Itoh Keiko Oikawa Akihiko Tajima Akira Koike Tadanori Aizawa Long-Tai Fu Fumihiko Miyake 《Circulation journal》2005,69(6):683-687
BACKGROUND: The magnitudes of the first (WI1) and the second wave-intensity peak (WI2) during the ejection period can be used as indices of left ventricular (LV) contractility and relaxation, respectively. However, use of WI to characterize LV dp/dt and the end-diastolic volume (V ed) relationship may be more problematic, as WI may be affected by changes in preload. METHODS AND RESULTS: The LV pressure-volume data sets, consisting of 23 recordings obtained by the conductance method from 12 heart disease patients, were studied. End-systolic elastance (E es) and volume-axis-intercept (V0) were calculated with varying preload. Time constant of LV relaxation (tau), V ed, and WI were calculated from steady-state averaged data. The E es showed a weak correlation with WI1 (r = 0.46, p < 0.05) but a better correlation with preload-adjusted WI1 [WI1/V ed; r=0.86, WI1/V(ed)2; r = 0.92, WI1/(V ed - V0)2; r = 0.89, all p < 0.01]. Similarly, tau did not correlate with WI2 but did correlate with preload-adjusted WI2 [WI2/V ed; r = -0.73, WI2/V(ed) 2; r = -0.63, WI2/(V ed - V0)2; r = -0.78, all p < 0.01]. CONCLUSIONS: These data demonstrate the importance of preload-adjustment when using the WI index for simultaneous assessment of LV contractility and relaxation. 相似文献
157.
Toshio Kurihara Takao Itoi Atsushi Sofuni Fumihide Itokawa Takayoshi Tsuchiya Shujirou Tsuji Kentaro Ishii Nobuhito Ikeuchi Akihiko Tsuchida Kazuhiko Kasuya Takashi Kawai Yoshihiro Sakai Fuminori Moriyasu 《Journal of hepato-biliary-pancreatic sciences》2008,15(2):189-195
Background/Purpose
It has been reported that circulating tumor cells (CTCs) can be used to predict survival in metastatic breast cancer. In this preliminary study, we examined the level of CTCs in pancreatic cancer (PC) patients to elucidate whether we could predict survival in PC.Methods
The eligible subjects, at Tokyo Medical University Hospital, were 26 patients with PC, 11 with chronic pancreatitis, and 10 healthy volunteers. Three PC patients underwent surgery, 18 patients (who were stage IV) were treated with gemcitabine (GEM), and 5 patients received best supportive care (BSC).Results
The CTC count was 1/7.5 ml blood or higher (defined as positive) in 11 of the 26 patients (42%; mean, 16.9/7.5 ml blood; range, 1-105/7.5 ml blood). Gemcitabine was administered to 6 of the 11 CTC-positive patients (3.8 courses on average). The treatment was continued for more than three courses in 2 patients, in both of whom the CTC count was only 1/7.5 ml blood. Operation was performed in 1 of the 11 CTC-positive patients. The remaining 4 patients of the 11 CTC-positive patients received only BSC. CTC was negative in 15 patients with PC (stage II, 1; stage III, 1; stage IVa, 7; and stage IVb, 6) and in the subjects with benign conditions. The median survival times (MSTs) of the CTC-positive and-negative patients were 110.5 and 375.8 days (P < 0.001). When the analysis was limited to the 14 stage-IVb patients, the MSTs of the CTC-positive and-negative patients were 52.5 and 308.3 days (P < 0.01).Conclusions
The present study demonstrated that the detection of CTCs in peripheral blood may be useful to predict prognosis in patients with PC. 相似文献158.
Yoshida N Nomura K Matsumoto Y Nishida K Wakabayashi N Konishi H Mitsufuji S Kataoka K Okanoue T Taniwaki M 《World journal of gastroenterology : WJG》2004,10(17):2602-2604
A 59-year-old woman was admitted to our hospital because of recurrent follicular lymphorna (FL). Colonoscopic examination revealed a rectal submucosal tumor (SMT) without any erosions and ulcers. In this patient, it was difficult to distinguish non-Hodgkin‘s lymphoma (NHL) invasion from other disorders of the colon including carcinoid tumor merely based on endoscopic findings. Histopathologic and immunohistochemical studies on biopsy specimens showed an infiltration of atypical lymphocytes that were positive for CD20 and BCL2 but negative for UCHL-1. Fluorescence in situ hybridization on paraffin-embedded tissue sections (T-FISH) identified a translocation of BCL2 with IGHgene.Based on these findings, the tumor was defined as an invasion of FL. T-FISH method is useful for the detection of a monoclonality of atypical lymphocytes in an SMT of the gastrointestinal tract, and particularly for the detection of chromosomal translocations specific to lymphoma subtypes. 相似文献
159.
Kunitake Hashiba MD Muneo Tanigawa MD Masahiko Fukatani MD Akihiko Shimizu MD Atsushi Konoe MD Mitsuo Kadena MD Mitsuhiro Mori MD 《The American journal of cardiology》1989,64(20):J20-J23
The electrophysiologic properties of atrial muscle were studied by programmed atrial stimulation in 42 patients with paroxysmal atrial fibrillation (PAF) and in 53 control patients without PAF. Single premature atrial stimulation was given at the right atrial appendage following 8 basic stimuli with a basic cycle length of 500 ms. Repetitive atrial firing (RAF) was defined as the occurrence of 2 or more successive premature atrial activations following single premature atrial stimulation. Fragmented atrial activity (FAA) was defined as an increase by more than 75% of the duration of the atrial electrogram in response to a single premature stimulation. Interatrial conduction delay was defined as an increase of the conduction time by more than 50 ms in response to a single premature stimulation. RAF was induced in 26 of 42 patients (61.9%) with PAF and in 14 of 53 control patients (26A%). FAA and interatrial conduction delay were elicited in 69.0 and 80.9% of patients with PAF and in 34.0 and 56.6% of control patients, respectively. In 16 patients with PAF in whom RAF was not induced, FAA developed in 11 patients (68.8%). In 88.1% of 42 patients with PAF and in 41.5% of 53 controls, RAF or FAA, or both, were elicited by atrial premature stimulation. It is concluded that the incidence of RAF and FAA were significantly higher in patients with PAF than in the control group, and the induction of RAF or FAA, or both, was closely related to the vulnerability of the atrial muscle to atrial fibrillation. 相似文献
160.
Ohga S Kubo E Nomura A Takada H Suga N Ishii E Suminoe A Inamitsu T Matsuzaki A Kasuga N Hara T 《International journal of hematology》2001,73(3):323-326
Epstein-Barr virus (EBV)-DNA was quantitatively measured to assess posttransplantation virus reactivation by real-time polymerase chain reaction (PCR). In the first retrospective analysis of a 7-year-old boy with lymphoproliferative disease (LPD) after an unrelated cord blood transplantation, serum EBV-DNA progressively increased to 4 x 10(5) copies/mL. EBV load was then prospectively monitored in peripheral blood from posttransplantation patients. The second case was an 8 year-old boy with aplastic anemia who received a CD34+ cell transplantation. This patient died of LPD with the progression of pulmonary nodules. EBV-DNA increased to 4 x 10(4) copies/mL after the control of cytomegalovirus reactivation. On the other hand, EBV-DNA was undetectable (<200 copies/mL) in the series of all 58 samples from 10 patients who did not develop LPD after hematopoietic stem cell transplantation. Sequential monitoring of circulating EBV-DNA by quantitative PCR may be a useful indicator for predicting the development of posttransplantation LPD. 相似文献