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   6660篇
  免费   265篇
  国内免费   41篇
耳鼻咽喉   81篇
儿科学   173篇
妇产科学   102篇
基础医学   840篇
口腔科学   166篇
临床医学   391篇
内科学   2084篇
皮肤病学   60篇
神经病学   429篇
特种医学   282篇
外科学   1075篇
综合类   21篇
预防医学   171篇
眼科学   116篇
药学   322篇
中国医学   12篇
肿瘤学   641篇
  2023年   39篇
  2022年   73篇
  2021年   149篇
  2020年   62篇
  2019年   89篇
  2018年   121篇
  2017年   118篇
  2016年   120篇
  2015年   130篇
  2014年   171篇
  2013年   215篇
  2012年   321篇
  2011年   361篇
  2010年   215篇
  2009年   147篇
  2008年   334篇
  2007年   343篇
  2006年   336篇
  2005年   377篇
  2004年   385篇
  2003年   349篇
  2002年   310篇
  2001年   208篇
  2000年   203篇
  1999年   177篇
  1998年   93篇
  1997年   69篇
  1996年   63篇
  1995年   49篇
  1994年   45篇
  1993年   38篇
  1992年   156篇
  1991年   118篇
  1990年   113篇
  1989年   143篇
  1988年   86篇
  1987年   99篇
  1986年   100篇
  1985年   93篇
  1984年   44篇
  1983年   45篇
  1982年   15篇
  1981年   15篇
  1980年   22篇
  1979年   26篇
  1978年   24篇
  1977年   21篇
  1973年   15篇
  1971年   16篇
  1969年   18篇
排序方式: 共有6966条查询结果,搜索用时 15 毫秒
91.
We report an adolescent developing ventilation failure due to supraglottic air leakage with the use of an uncuffed hand-made tracheal tube fit to her tracheobronchial deformity. To eliminate the supraglottic air leakage, a size 2.5 laryngeal mask airway (LMA) was inserted into the oral pharynx. Most of air leakage arose from the LMA. Supraglottic air leakage was not detected under mandatory mechanical ventilation following sealing of the 15-mm connector of the LMA with a piece of tape, and the respiratory condition of the patient gradually improved. The combination of a hand-made Y-shaped tube and the LMA was useful in restoring adequate ventilation. In conditions where air leaks through the glottis during mechanical ventilation interfere with adequate ventilation or the maintenance of airway pressure, the use of an LMA may be adequate to stop or significantly decrease the leak.  相似文献   
92.
We experienced the anesthetic management using high-dose dexmedetomidine for microlaryngeal surgery maintaining spontaneous breathing. The anesthesia was maintained with dexmedetomidine infusion (initial dose 6 microg x kg(-1) x hr(-1) over 10 min followed by continuous infusion of 0.5 microg x kg(-1) x hr(-1)), intermittent small doses of fentanyl and topical application of lidocaine on the tongue, pharynx and larynx. The infusion of dexmedetomidine was increased over 30 min to 3 microg x kg(-1) x hr(-1) to reach the adequate sedation level and maintained at this rate for a further 15 min during the operation. During the whole perioperative period, there was no respiratory depression as measured by arterial blood gas analysis that recorded normal PaCO2 in the patient breathing supplemental oxygen. Hypotension (systemic arterial blood pressure less than 100 mmHg) occurred twice during dexmedetomidine administration, but was normolized by ephedrine administration. The preservation of respiratory drive offers the possibility that this anesthetic technique may be another method for providing anesthesia for the patient with a difficult airway. Moreover, there is one consensus on the importance of the basic principle that adequate topical or intravenous anesthesia is also essential during high-dose dexmedetomidine infusion.  相似文献   
93.
To analyze human herpesvirus 6 (HHV-6) infection in adult living related liver transplantation, we performed a virological analysis, including viral isolation, serological assay, and real-time polymerase chain reaction, of serially collected blood samples from 67 recipients. In addition, cytokine levels were measured to determine their role in viral reactivation. HHV-6 was isolated from only 4 recipients (6.0%), and viral DNA was detected in 15 (22.4%) of the 67 recipients. A significant increase in HHV-6 immunoglobulin G antibody titers was observed in 19 (28.4%) of the 67 recipients. Finally, 26 recipients (38.8%) had HHV-6 reactivation 2-6 weeks after transplantation. HHV-6 associated clinical features were analyzed in the 17 recipients presenting with either viremia or DNAemia. Two recipients with viremia and 3 recipients with DNAemia had unexplained fever at the time of viral infection. An increase in aminotransferase levels was observed in 2 recipients with viremia and 3 recipients with DNAemia. Recipients with liver cirrhosis caused by hepatitis B virus or hepatitis C virus infection as the underlying disease were more likely to have HHV-6 infection (P = 0.025). Mortality at the last follow-up in recipients with HHV-6 reactivation was significantly higher than in those without viral reactivation (P = 0.0118). Plasma interleukin-6 levels were significantly higher in the recipients with HHV-6 viremia than in the recipients without viremia at 4 weeks post-transplant (P = 0.0411). Moreover, tumor necrosis factor alpha levels were also higher in recipients with HHV-6 viremia (P < 0.0001) or reactivation (P = 0.0011) than in recipients without viremia or reactivation 4 weeks post-transplant.  相似文献   
94.
We report two cases of prostatic carcinoma presenting as neck lymph node metastases. Case 1: A 56-year-old man was admitted to our hospital with the chief complaint of left lower abdominal pain. A lymph node was palpable on the left side of the neck swollen. Rectal examinations revealed prostatic stony-hard mass. Computed tomography showed a swollen neck and paraaortic lymph nodes on the left side. PSA level was 380 ng/ml. Transperineal prostatic biopsy revealed moderately differentiated adenocarcinoma, and neck lymph node biopsy also revealed metastatic adenocarcinoma. We diagnosed him with prostatic carcinoma stage D2 (LYM). He underwent hormonal therapy (TAB) but died 13 months later. Case 2: A 66-year-old man was admitted to our hospital with the chief complaint of a large palpable mass on the left side of the neck. Resection of this mass revealed metastatic adenocarcinoma. Rectal examination revealed no malignant lesions, but the PSA level was high, 1,700 ng/ml. Transperineal prostatic biopsy revealed moderately differentiated adenocarcinoma. Computed tomography revealed paraaortic and pelvic lymph node metastases and bone scintigram revealed abnormal uptake, bone metastases. We diagnosed him with prostatic carcinoma stage D2 (LYM OSS). We performed bilateral testectomy followed by hormonal therapy (TAB). The lymph node metastases disappeared after 4 months of therapy.  相似文献   
95.
Abstract:  Tuberculosis remains one of the most serious infections after organ transplantation. Isoniazid prophylaxis for liver transplant recipients with a history of tuberculosis is generally recommended. However, its benefit is controversial because of potential hepatotoxicity of isoniazid. It is crucial to determine appropriate post-transplant managements for the recipients with a history of tuberculosis. The purpose of this study was to investigate the necessity of isoniazid prophylaxis for liver transplant recipients who had a history of tuberculosis. The medical records of 1116 liver transplant recipients were studied, of whom seven had a history of tuberculosis (0.63%). One who underwent living-donor liver transplantation for fulminant hepatic failure was excluded from evaluation because of early death, caused by bacterial sepsis two months after transplantation, although reactivation of tuberculosis was not observed. The median observation period after transplantation was 25.5 months (range 12–82). Reactivation of tuberculosis did not occur in any of these six patients. In conclusion, we could not find rationale for isoniazid prophylaxis in liver transplant recipients with past diagnosis of tuberculosis, when the disease is considered to be inactive. Tuberculosis should be considered as cause of post-transplant infections, and careful post-transplant observations are essential for an early diagnosis.  相似文献   
96.
BACKGROUND: Myeloablative cord blood transplantation (CBT) for adult patients offers a 90% chance of engraftment with a 50% rate of transplant-related mortality, mostly attributable to infection. We have demonstrated the feasibility of reduced-intensity CBT (RI-CBT) for adult patients, in which cyclosporine was used for acute graft-versus-host disease (GVHD) prophylaxis. Transplantation-related mortality (TRM) was 27% within 100 days. Therefore our objective was to evaluate the feasibility of RI-CBT with tacrolimus as GVHD prophylaxis for adult patients with hematologic malignancies. METHODS: Thirty-four patients with a median age of 56.5 years (range; 22-68) with hematologic diseases underwent RI-CBT at Toranomon Hospital between November 2003 and September 2004. Preparative regimen comprised fludarabine 25 mg/m2 on days -7 to -3, melphalan 80 mg/m2 on day -2, and 4 Gy total body irradiation on day -1. GVHD prophylaxis was continuous intravenous infusion of tacrolimus 0.03 mg/kg, starting on day -1. RESULTS: Thirty-one patients achieved neutrophil engraftment at a median of day 20. Median infused total cell dose was 2.4 x 10E7/kg (range; 1.6-4.8). Thirty-two patients achieved complete donor chimerism at day 60. Grade II-IV acute GVHD occurred in 45% of patients, with a median onset of day 26. Primary disease recurred in five patients, and TRM within 100 days was 12%. Estimated 1-year overall survival was 70%. CONCLUSION: This study demonstrated the possible improvement in transplant-related mortality by tacrolimus as GVHD prophylaxis in adult RI-CBT recipients.  相似文献   
97.
We have found that steroid bolus withdrawal prior to graft reperfusion increased the incidence of acute cellular rejection (ACR). This study aims to clarify how initial steroid bolus (ISB) injection at reperfusion influences the kinetics of CD8(+) alloreactive immune responses immediately after living donor liver transplantation (LDLT). A total of 49 hepatitis C virus (HCV)-infected recipients were classified into 3 groups according to hierarchical clustering by preoperative CD8(+)CD45 isoforms. The naive T cell proportion was considerably higher in Group I than in Groups II and III, whereas Group II recipients had the highest effector memory (EM) T cells and Group III the highest effector T cells. The frequency of ACR was significantly higher in recipients without ISB than in those with ISB. In particular, the ACR rates were the highest in Group II without ISB. Following ISB, the proportion of effector T cells was promptly upregulated within 6 hours after graft reperfusion, simultaneously with the upregulation of CD27(-)CD28(-) subsets, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha and perforin expression, which significantly correlated with increasing interleukin (IL)-12 receptor beta 1 cells. These were then downregulated to below preoperative levels by tacrolimus (Tac) administered at 24 hours. These changes did not occur in the absence of ISB. In Group II without ISB, the downregulation of IL-12Rbeta1(+) cells was the greatest, consistent with the highest rates of ACR and mortality (60%). In conclusion, ISB must be done in place, especially in Group II with preexisting high EM T cells, to enable the development of early allograft acceptance.  相似文献   
98.
In the present study, the results of living donor liver transplantation (LDLT) for 125 hepatocellular carcinoma (HCC) patients were analyzed to determine optimal criteria exceeding the Milan criteria (MC) but still with predictably good outcomes. On the basis of pretransplant imaging studies, 70 patients met the MC, and 55 patients did not. Patients who exceeded the MC but presented with 相似文献   
99.

Background

Mesenchymal stem cells (MSCs) are being developed as a new clinically relevant stem cell type to be recruited into and to repair injured tissue. A number of studies have focused on the therapeutic potential of MSCs by virtue of their immunomodulatory properties. Systemically administered MSCs can also migrate to sites of malignancies. Because of this latter phenomenon, we transfected human MSCs to secrete anti–high mobility group box (HMGB) 1 proteins. They were then injected into mice bearing human colon cancer to evaluate their efficacy as an antineoplastic agent.

Materials and methods

The ABOX gene was used in this model, which encodes part of the HMGB1 protein and acts as an HMGB1 antagonist. It was cotransduced by electroporation with a FLAG-tag to visualize the secreted ABOX protein, levels of which in supernatants from cultured transfected MSCs were quantified by immunofluorescence imaging using an anti-FLAG antibody. Antiangiogenic effects were evaluated in vitro using a novel optical assay device for the quantitative measurement of cellular chemotaxis assessing the velocity and direction of endothelial cell movement stimulated by supernatant from tumor cells. We found that ABOX proteins released from transfected MSCs suppressed migration in this assay. Finally, MSCs were injected subcutaneously into Nonobese diabetic/severe combined immunodeficiency mice bearing human colon cancer from a cell line, which secreted large amounts of HMGB1. Ten days after MSC injection, mice were sacrificed and tumors evaluated by immunohistochemistry.

Results

From 12 ho through 7 d after gene transfection, ABOX proteins secreted from MSCs could be detected by immunofluorescence and enzyme-linked immunosorbent assay. Quantitative measurement of cellular chemotaxis demonstrated that ABOX proteins secreted from transfected MSCs decreased the velocity and interfered with the direction of movement of vascular endothelial cells. Moreover, in an in vivo human colon cancer xenograft model, injection of anti-HMGB1–transfected MSCs resulted in a decreased tumor volume due to the antiangiogenic properties of the secreted ABOX proteins.

Conclusions

MSC modified to secrete HMGB1 antagonist proteins have therapeutic antineoplastic potential. These findings may contribute to future novel targeting strategies using autologous bone marrow–derived cells as gene delivery vectors.  相似文献   
100.

Purpose

To evaluate the anatomical variations in the middle hepatic vein tributaries (V5/V8) for determining the reconstruction strategy in right lobe living donor liver transplantation (LDLT).

Methods

The V5/V8 variations were examined in 268 patients and were classified into three and two types, respectively. The reconstruction rate (RR), patency rate (PR) and clinical outcomes were retrospectively evaluated in 46 right lobe LDLT cases.

Results

In terms of V5 variations, the RR and PR were significantly higher for type 2 than type 3 (82.6 vs. 44.4 % and 73.7 vs. 25.0 %, respectively). The alanine aminotransferase level on postoperative day (POD) 5 in the V5 patent group was significantly lower than in the occluded group (123 vs. 191 IU/dL). Regarding V8 variations, the RR and PR were significantly higher for type 1 than type 2 (44.4 vs. 17.6 % and 75.0 vs. 33.3 %, respectively). The aspartate aminotransferase level on POD 3 was significantly lower in the V8 patent group than in the occluded group (50 vs. 121 IU/dL).

Conclusion

For right lobe grafts with single large V5 (type 2) or V8 (type 1) variations, reconstruction is necessary. Our new classification of the MHV tributaries is useful for determining the reconstruction strategy to use in right lobe LDLT.  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