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   1134篇
  免费   68篇
耳鼻咽喉   11篇
儿科学   19篇
妇产科学   21篇
基础医学   126篇
口腔科学   23篇
临床医学   77篇
内科学   300篇
皮肤病学   9篇
神经病学   42篇
特种医学   30篇
外科学   167篇
综合类   15篇
预防医学   70篇
眼科学   7篇
药学   115篇
中国医学   2篇
肿瘤学   168篇
  2024年   2篇
  2023年   7篇
  2022年   20篇
  2021年   36篇
  2020年   14篇
  2019年   43篇
  2018年   42篇
  2017年   30篇
  2016年   25篇
  2015年   28篇
  2014年   40篇
  2013年   40篇
  2012年   66篇
  2011年   78篇
  2010年   32篇
  2009年   32篇
  2008年   47篇
  2007年   57篇
  2006年   65篇
  2005年   63篇
  2004年   47篇
  2003年   56篇
  2002年   46篇
  2001年   34篇
  2000年   22篇
  1999年   27篇
  1998年   9篇
  1997年   5篇
  1996年   9篇
  1995年   4篇
  1994年   10篇
  1993年   2篇
  1992年   8篇
  1991年   17篇
  1990年   14篇
  1989年   14篇
  1988年   21篇
  1987年   19篇
  1986年   10篇
  1985年   8篇
  1984年   15篇
  1983年   10篇
  1982年   8篇
  1981年   5篇
  1980年   2篇
  1979年   5篇
  1974年   2篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有1202条查询结果,搜索用时 15 毫秒
971.
972.
Introduction: In addition to the affected person, diagnosis and treatment of breast cancer also severely affects her husband. Therefore, it is worth paying attention to the needs of husbands of women with breast cancer. Therefore, the aim of the present study was to explain the experiences of spouses of women with breast cancer. Method: The present study was a qualitative study with conventional content analysis approach. Purposive sampling was carried out by selecting 6 spouses of women with breast cancer. Data were collected through semi-structured interview. The recorded interviews were transcribed verbatim. Content analysis was used to reduce and name the data, obtain analytical codes, and finally recognize the theme. Results: Data analysis resulted in the extraction of 4 categories of couples’ mental challenges, multifaceted romantic meditation, multifaceted traumas caused by the disease, dual energies (inductions) of relatives, and 12 subcategories. Conclusion: In spite of suffering from all the challenges and traumas, husbands of women with breast cancer have not left their wives alone and have done their best to improve their lives; so, we can raise ““Scarifying your life to save your wife’s life”” as an extract from the experience of spouses of women with breast cancer. Knowing and understanding this point by clinical staffs and policy makers can provide pave the way for planning to provide comprehensive support to these men.  相似文献   
973.
974.
975.

OBJECTIVE:

The aim of this study is to determine clinical, pathological, and treatment-relevant variables associated with long-term (90-month) overall survival in patients with lung metastases undergoing pulmonary metastasectomy.

METHODS:

A retrospective review was performed of patients who were admitted with lung metastases, and who underwent thoracotomy for resection, after treatment of a primary tumor. Data were collected regarding demographics, tumor features, treatment, and outcome.

RESULTS:

Patients (n = 529) were submitted to a total of 776 thoracotomies. Median follow-up time across all patients was 21.6 months (range: 0–192 months). The postoperative complication rate was 9.3%, and the 30-day mortality rate was 0.2%. The ninety-month overall survival rate for all patients was 30.4%. Multivariate analysis identified the number of pulmonary nodules detected on preoperative CT-scan, the number of malignant nodules resected, and complete resection as the independent prognostic factors for overall survival.

CONCLUSION:

These results confirm that lung metastasectomy is a safe and potentially curative procedure for patients with treated primary tumors. A select group of patients can achieve long-term survival after resection.  相似文献   
976.
Ventricular remodeling of both geometry and fiber structure is a prominent feature of several cardiac pathologies. Advances in MRI and analytical methods now make it possible to measure changes of cardiac geometry, fiber, and sheet orientation at high spatial resolution. In this report, we use diffusion tensor imaging to measure the geometry, fiber, and sheet architecture of eight normal and five dyssynchronous failing canine hearts, which were explanted and fixed in an unloaded state. We apply novel computational methods to identify statistically significant changes of cardiac anatomic structure in the failing and control heart populations. The results demonstrate significant regional differences in geometric remodeling in the dyssynchronous failing heart versus control. Ventricular chamber dilatation and reduction in wall thickness in septal and some posterior and anterior regions are observed. Primary fiber orientation showed no significant change. However, this result coupled with the local wall thinning in the septum implies an altered transmural fiber gradient. Further, we observe that orientation of laminar sheets become more vertical in the early-activated septum, with no significant change of sheet orientation in the late-activated lateral wall. Measured changes in both fiber gradient and sheet structure will affect both the heterogeneity of passive myocardial properties as well as electrical activation of the ventricles.  相似文献   
977.
Activation of the phosphatidylinositol 3-kinase (PI(3)K) pathway has been linked with tumour cell growth, survival and resistance to therapy in several cancer types. The active, phosphorylated form of Akt (pAkt) was found to be aberrantly expressed in Hodgkin lymphoma (HL)-derived cell lines and in Hodgkin-Reed-Sternberg (HRS) cells in 27 of 42 (64.3%) of primary lymph node sections of HL, indicative of PI(3)K activity. Akt phosphorylation was not associated with loss of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) expression, but with its phosphorylation in HL-cell lines, suggesting that its biological function is impaired. Akt phosphorylation was further induced by CD30 ligand (CD30L), CD40L and receptor activator of nuclear factor kappa B (RANK) ligand. The PI(3)K inhibitor LY294002 demonstrated antiproliferative effects in a dose- and time-dependent manner, which was associated with Akt dephosphorylation on Thr308 and Ser473 sites and dephosphorylation of the downstream ribosomal protein S6. LY209002 induced cell cycle arrest in the G0/G1 phase and apoptosis, which were associated with upregulation of MDM2, downregulation of cyclin D1, activation of caspase 9 and poly-ADP-ribose polymerase cleavage. The Akt inhibitor QLT394 also demonstrated antiproliferative effects in a dose- and time-dependent manner, dephosphorylated ribosomal S6 and cleaved caspase 9. Collectively, these data suggest that the aberrant activation of the PI(3)K/Akt survival pathway in HRS cells is not because of loss of PTEN expression. Our data suggest that PTEN phosphorylation and activation of CD30, CD40 and RANK may play a role in activating Akt in HRS cells.  相似文献   
978.
Salinosporamide A (also called NPI-0052), recently identified from the marine bacterium Salinispora tropica, is a potent inhibitor of 20S proteasome and exhibits therapeutic potential against a wide variety of tumors through a poorly understood mechanism. Here we demonstrate that salinosporamide A potentiated the apoptosis induced by tumor necrosis factor alpha (TNF), bortezomib, and thalidomide, and this correlated with down-regulation of gene products that mediate cell proliferation (cyclin D1, cyclooxygenase-2 [COX-2], and c-Myc), cell survival (Bcl-2, Bcl-xL, cFLIP, TRAF1, IAP1, IAP2, and survivin), invasion (matrix metallopro-teinase-9 [MMP-9] and ICAM-1), and angiogenesis (vascular endothelial growth factor [VEGF]). Salinosporamide A also suppressed TNF-induced tumor cell invasion and receptor activator of nuclear factor kappaB ligand (RANKL)-induced osteoclastogenesis. We also found that it suppressed both constitutive and inducible NF-kappaB activation. Compared with bortezomib, MG-132, N-acetyl-leucyl-leucyl-norleucinal (ALLN), and lactacystin, salinosporamide A was found to be the most potent suppressor of NF-kappaB activation. Further studies showed that salinosporamide A inhibited TNF-induced inhibitory subunit of NF-kappaB alpha (IkappaBalpha) degradation, nuclear translocation of p65, and NF-kappaB-dependent reporter gene expression but had no effect on IkappaBalpha kinase activation, IkappaBalpha phosphorylation, or IkappaBalpha ubiquitination. Thus, overall, our results indicate that salinosporamide A enhances apoptosis, suppresses osteoclastogenesis, and inhibits invasion through suppression of the NF-kappaB pathway.  相似文献   
979.
R N Younes  J L Gross  D Deheinzelin 《Chest》1999,115(6):1494-1499
OBJECTIVES: The present study evaluates the cost-effectiveness of two follow-up routines: a strict follow-up with frequent visits, imaging, and laboratory examinations was compared to a follow-up with infrequent visits that were scheduled mainly on the basis of the patient's symptoms. METHODS: A retrospective evaluation was undertaken of 130 patients who underwent a complete resection of non-small cell lung cancer (NSCLC). All patients had complete follow-up for at least 2 years after their operation. The patients were separated into two groups: strict (n = 67), with a routine follow-up policy; and symptom (n = 63), seen on a symptom-oriented basis. The costs of the follow-up routines and the yield of each schedule were compared between the two groups. RESULTS: There were no significant differences in the disease-free interval until the first detection of recurrence. In most patients, metastatic diseases were diagnosed on the basis of symptoms, rather than by routine tests. The patients who had recurrent cancer diagnosed after surgery had a dismal survival rate irrespective of the follow-up schedule. The majority of patients with recurrence died of malignancy within a 2-year period. The costs of strict vs symptom follow-up were significantly different, because of the greater number of routine imaging procedures performed in patients having strict follow-up. On the other hand, when we analyzed only the frequency of hospitalization and the cost per day of hospital treatment for medical problems other than cancer recurrence, the patients in the strict group had a less expensive follow-up than the patients in the symptom group. CONCLUSIONS: The present study showed that a more cost-effective routine follow-up scheme should be advised for patients with completely resected NSCLC, without affecting overall outcome. Routine imaging follow-up is of questionable value, and it may be indicated only in academic settings.  相似文献   
980.
Cadmium (Cd(2+)) is a heavy metal that is dispersed throughout the modern environment mainly as a result of pollution from a variety of sources. The aims of the current study were to investigate the efficacy of purified Tunisian montmorillonite clay (TMC) to adsorb Cd, to test the stability of the resulting complex under different conditions in vitro, and to utilize the rat bioassay as an in vivo model to evaluate the protective role of TMC against Cd-induced toxicity and immunodysfunction. In the in vitro study, three concentrations of TMC (0.5, 1.0 and 1.5 g/l aqueous solution) and three concentrations of CdCl(2) (25, 50 and 100 ppm) were tested. The results of the in vitro study showed that TMC had a high capacity of adsorbing Cd at different concentrations tested. The adsorption ranged from 95.7-100% of the available CdCl(2) in aqueous solutions. The complex TMC-Cd was stable at different pHs at 37 degrees C. The in vivo results indicated that treatment with CdCl(2) (2.5 mg/kg BW) for 2 weeks resulted in a significant decrease in triglycerides, total protein, creatinine, creatine kinase, immunoglobulin profile (Ig A and Ig G) and T-cell sub-types (CD3(+), CD4(+), CD8(+) and CD56(+)). Whereas, it significantly increase serum level of AST, ALT, LDH and induced degenerative changes in pro-inflammatory cytokines (TNF-alpha and IL-1). Rats treated with TMC alone (400, 600 and 800 mg/kg BW) were comparable to the control regarding all the tested parameters. The combined treatment of CdCl(2) and TMC at the lowest dose (400 mg/kg BW) showed a significant improvement of all tested parameters. It could be concluded that TMC was effective to protect against Cd hazards at a dose as low as 400 mg/kg BW. These results supported our hypothesis that TMC tightly-bind and immobilized Cd resulted in reduction of metal bioavailability in the gastrointestinal tract.  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