首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   10567篇
  免费   347篇
  国内免费   89篇
耳鼻咽喉   100篇
儿科学   179篇
妇产科学   78篇
基础医学   1151篇
口腔科学   201篇
临床医学   561篇
内科学   3148篇
皮肤病学   154篇
神经病学   747篇
特种医学   438篇
外科学   1737篇
综合类   46篇
预防医学   275篇
眼科学   174篇
药学   731篇
中国医学   14篇
肿瘤学   1269篇
  2024年   38篇
  2023年   86篇
  2022年   133篇
  2021年   267篇
  2020年   165篇
  2019年   205篇
  2018年   241篇
  2017年   197篇
  2016年   245篇
  2015年   261篇
  2014年   331篇
  2013年   386篇
  2012年   660篇
  2011年   669篇
  2010年   359篇
  2009年   360篇
  2008年   654篇
  2007年   725篇
  2006年   689篇
  2005年   697篇
  2004年   683篇
  2003年   627篇
  2002年   637篇
  2001年   132篇
  2000年   136篇
  1999年   138篇
  1998年   142篇
  1997年   104篇
  1996年   89篇
  1995年   93篇
  1994年   73篇
  1993年   58篇
  1992年   89篇
  1991年   71篇
  1990年   65篇
  1989年   57篇
  1988年   59篇
  1987年   67篇
  1986年   47篇
  1985年   50篇
  1984年   41篇
  1983年   26篇
  1982年   23篇
  1981年   12篇
  1980年   12篇
  1979年   20篇
  1978年   13篇
  1977年   9篇
  1976年   11篇
  1975年   7篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Intestinal mucosal injury that develops as a complication of tocilizumab (TCZ) is usually associated with diverticulosis. We herein report a rare case of TCZ-induced intestinal mucosal injury in the absence of diverticulosis. A 74-year-old woman suffering from rheumatoid arthritis started taking TCZ. Six months later, she complained of hematochezia and abdominal pain. Colonoscopy revealed multiple ulcers spreading from the cecum to the transverse colon but no diverticulosis. These lesions were cured at three months after the discontinuation of TCZ. We should consider TCZ as a risk factor for intestinal mucosal injury, even if patients have no history of intestinal disease associated with diverticulosis.  相似文献   
82.
Cryopyrin-associated periodic syndrome (CAPS) is a spectrum of systemic autoinflammatory disorders in which the majority of patients have mutations in the cold-induced autoinflammatory syndrome (CIAS)1 gene. Despite having indistinguishable clinical features, some patients lack CIAS1 mutations by conventional nucleotide sequencing. We recently reported a CAPS patient with mosaicism of mutant CIAS1, and raised the possibility that CIAS1 mutations were overlooked in "mutation-negative" patients, due to a low frequency of mosaicism. To determine whether there were latent mutant cells in "mutation-negative" patients, we sought to identify mutation-associated biologic phenotypes of patients' monocytes. We found that lipopolysaccharide selectively induced necrosis-like cell death in monocytes bearing CIAS1 mutations. Monocyte death correlated with CIAS1 up-regulation, was dependent on cathepsin B, and was independent of caspase-1. Cell death was intrinsic to CIAS1-mutated monocytes, was not mediated by the inflammatory milieu, and was independent of disease severity or anti-IL-1 therapy. By collecting dying monocytes after lipopolysaccharide treatment, we succeeded in enriching CIAS1-mutant monocytes and identifying low-level CIAS1-mosaicism in 3 of 4 "mutation-negative" CAPS patients. Our findings reveal a novel effect of CIAS1 mutations in promoting necrosis-like cell death, and demonstrate that CIAS1 mosaicism plays an important role in mutation-negative CAPS patients.  相似文献   
83.
OBJECTIVE: The study evaluated the utility of transplanting bone marrow stromal cells in a porcine myocardial infarction model. METHODS: A myocardial infarction was created by occluding the distal left anterior descending artery in pigs with coils and Gelfoam sponge. Sternal bone marrow was aspirated, and stromal cells were cultured and induced to differentiate to a myogenic phenotype with 5-azacytidine. Four weeks after coronary artery occlusion, sestamibi technetium single-photon emission computed tomographic scans were performed, and then either a graft of 100 x 10(6) bone marrow stromal cells (n = 5, 30% labeled with bromodeoxyuridine) or culture medium (n = 6) was injected into the infarct region. Four weeks later the tomographic scans were repeated and cardiac function was assessed with pressure and volume measurements. Morphologic and histologic characteristics of the heart were also studied. RESULTS: Histologic examination found bromodeoxyuridine-labeled cells within the infarct region in islands that had sarcomeres and Z-bands and stained positively for cardiac specific troponin I. The bone marrow stromal cell transplant sites had a greater (P <.05) capillary density than did the control sites. The tomographic scans showed that the hearts with the cell transplants had increases in stroke volume, regional perfusion, and wall motion (P <.05 for all groups) relative to the control hearts. The pressure-volume analysis showed improvement (P <.05) in end-systolic elastance and preload recruitable stroke work in the transplantation group relative to the control group. The left ventricular chamber size was smaller (P <.05) and the scar thickness was greater (P <.05) in the hearts with transplanted cells than in the control hearts (P =.06). CONCLUSION: 5-Azacytidine-treated bone marrow stromal cells transplanted into the myocardial infarct region formed islands of cardiac-like tissue, induced angiogenesis, prevented thinning and dilatation of the infarct region, and improved regional and global contractile function.  相似文献   
84.
A case of adult-to-adult, living-donor liver transplantation using a right liver graft is described. In the donor operation, when the middle hepatic vein (MHV) was clamped after hepatic transection, reversed flow was detected in MHV tributaries by intraoperative color Doppler ultrasonography. Regurgitated flow in the clamped inferior right hepatic vein was also demonstrated. Portal flow remained hepatopetal during the procedure. Based on these ultrasonographic findings, neither the MHV tributaries nor the inferior right hepatic vein was reconstructed.  相似文献   
85.
Shigeno T  Kumai J  Endo M  Oya S  Hotta S 《Neurologia medico-chirurgica》2002,42(4):184-9; discussion 190
Recurrence of trigeminal neuralgia (TN) or hemifacial spasm (HFS) after microvascular decompression (MVD) is not rare. The prosthesis material eventually adheres to the neurovascular structures and again transmits arterial pulsation to the nerve. A snare ligature technique using a Gore-Tex tape can be used for the transposition of the offending artery. No prosthesis is necessary once the transposition is complete. This technique requires introduction of either Gore-Tex tape or thread around the artery and suture over the petrous dura, so an adequate working space as if operating in a shallow basin is essential. Therefore, the osteoplastic craniotomy is a little larger than usual with the scalp flap entirely reflected using a semicircular skin incision. The Gore-Tex tape can be directly snared around the artery and sutured over the petrous dura. If this procedure is difficult, a thread can be attached to both ends of the Gore-Tex tape to pass the tape around the vessel. Seven patients with TN and 13 patients with HFS have undergone this surgery. Although the follow-up period is not yet long enough, there has been no case of recurrence. The present technique for MVD can provide complete and permanent transposition of the offending artery.  相似文献   
86.
BACKGROUND: Recently, we have described a drug (cyclophosphamide [CP] plus busulfan [BU])-induced skin allograft tolerance in mice that can regularly overcome fully H-2-mismatched barriers. Using this method, we have investigated whether or not this regimen can prolong the survival of heart allografts and inhibit the development of posttransplant cardiac allograft vasculopathy (CAV). METHODS: The components of the method are intravenous administration of 1 x 108 allogeneic spleen cells on day 0, intraperitoneal injection of 200 mg/kg of CP and 30 mg/kg of BU on day 2, and intravenous injection of T cell-depleted 1 x 107 allogeneic bone marrow cells from the same strain of mice on day 3. Heart grafting was performed on day 28. Chimerism in peripheral blood was followed by flow cytometric analysis, and histological analysis was performed at various times after grafting. RESULTS: In a fully major histocompatability complex (MHC)-mismatched combination of B10.D2 (H-2d, IE+)-->B10 (H-2b, IE-), stable, multilineage-mixed chimerism was observed permanently. B10.D2 heart grafts were accepted permanently in a donor-specific manner, and posttransplant CAV did not develop. CONCLUSIONS: These results demonstrated that the drug-induced tolerance recently established by us can regularly induce a long-lasting heart allograft tolerance without development of CAV.  相似文献   
87.
We report a rare case of congenital absence of the L5-S1 facet joint, which was associated with a conjoined nerve root. Combination of these two anomalies has been quite rarely reported in the literature. A 39-year-old man presented with acute low back pain and right leg radiating pain. Muscle weakness and sensory disturbance of the right leg were also apparent in the region innervated by L5 and S1 nerve roots. Preoperative multidetector three-dimensional computed tomography (3D-CT) showed complete absence of the right S1 superior articular process. Magnetic resonance (MR) images showed lumbar disc herniation at right L5-S1 level that migrated cranially. Intraoperative findings revealed that the right L5 nerve root and S1 nerve root were conjoined, and the conjoined nerve root was compressed by L5-S1 disc herniation, which led to impairment of the conjoined nerve root by a single-level lumbar disc herniation. After removal of the disc herniation, his right leg pain immediately subsided, however muscle weakness and sensory disturbance persisted. Surgeons should be aware of this nerve root anomaly when examining a patient who shows an unusual clinical presentation and/or congenital osseous anomaly.  相似文献   
88.
Background: The aim of this study was to investigate the effects of two imidazoline-derived intravenous anesthetics, etomidate and midazolam, on vascular adenosine triphosphate-sensitive potassium (KATP) channel activity.

Methods: In isolated rat aorta, isometric tension was recorded to examine the anesthetic effects on vasodilator response to levcromakalim, a selective KATP channel opener. Using the patch clamp method, the anesthetic effects were also examined on the currents through (1) native vascular KATP channels, (2) recombinant KATP channels with different combinations of various types of inwardly rectifying potassium channel (Kir6.0 family: Kir6.1, 6.2) and sulfonylurea receptor (SUR1, 2A, 2B) subunits, (3) SUR-deficient channels derived from a truncated isoform of Kir6.2 subunit (Kir6.2[DELTA]C36 channels), and (4) mutant Kir6.2[DELTA]C36 channels with reduced sensitivity to adenosine triphosphate (Kir6.2[DELTA]C36-K185Q channels).

Results: Etomidate (>= 10-6 m), but not midazolam (up to 10-6 m), inhibited the levcromakalim-induced vasodilation, which was sensitive to glibenclamide (IC50: 7.21 x 10-8 m; maximum inhibitory concentration: 1.22 x 10-4 m). Etomidate (>= 3 x 10-6 m), but not midazolam (up to 10-4 m), inhibited the native KATP channel activity in both cell-attached and inside-out configurations with IC50 values of 1.68 x 10-5 m and 1.52 x 10-5 m, respectively. Etomidate (10-5 m) also inhibited the activity of various types of recombinant SUR/Kir6.0KATP channels, Kir6.2[DELTA]C36 channels, and Kir6.2[DELTA]C36-K185Q channels with equivalent potency.  相似文献   

89.
成人活体肝移植   总被引:1,自引:0,他引:1  
活体肝移植(LDLT)最初作为一种降低等待做肝移植患者死亡率的方法。日本京都大学LDLT开始于1990年6月,移植例数逐年增加,临床应用范围从小儿扩展到成人。肝脏右叶移植物的应用在LDLT具有重要临床意义,已经成为成人间LDLT标准方法。由于肝脏右叶移植物在LDLT移植后成功应用,近年来成人LDLT例数显著增加,自1990年6月至2005年12月,京都大学附属病院已完成了1140例LDLT手术,其中包括477例成人LDLT手术(年龄大于18岁)。HBV和HCV相关性肝硬化和肝癌是LDLT最常见的适应证,截至2005年12月,随访统计结果表明成人LDLT术后总的5年生存率为69.1%。  相似文献   
90.
Background We investigated factors affecting 5-year survival in patients undergoing hepatic resection for colorectal cancer metastases, including events long after initial hepatectomy. Although retrospective studies have demonstrated survival benefit of hepatectomy for metastatic colorectal cancer, few have included sufficient 5-year survivors to identify survival-related factors throughout the clinical course. Methods We divided 156 patients with hepatectomy for colorectal cancer metastases into 5-year survivors (n = 64) and patients dying before 5 years after hepatectomy (n = 92). Clinicopathologic data were compared retrospectively with respect to long-term outcome. Results By multivariate analysis, large liver tumors (adjusted relative risk, 2.029; P = .011), short tumor doubling time (1.809; P = .026), and origin from poorly differentiated primary adenocarcinoma (12.632; P = .001) compromised survival, whereas initial treatment-related variables did not. Although no difference was seen in initial treatment-related variables between 5-year survivors with recurrence after hepatectomy and patients dying before 5 years, repeat surgery was used more frequently in survivors (P < .001), typically with adjuvant chemotherapy. Conclusions Reoperations for each recurrence of metastases, followed by additional chemotherapy, frequently resulted in long survival.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号