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   877篇
  免费   49篇
  国内免费   4篇
耳鼻咽喉   7篇
儿科学   10篇
妇产科学   68篇
基础医学   69篇
口腔科学   39篇
临床医学   113篇
内科学   194篇
皮肤病学   7篇
神经病学   52篇
特种医学   22篇
外科学   102篇
综合类   8篇
预防医学   39篇
眼科学   4篇
药学   69篇
中国医学   5篇
肿瘤学   122篇
  2023年   7篇
  2022年   6篇
  2021年   27篇
  2020年   16篇
  2019年   18篇
  2018年   29篇
  2017年   16篇
  2016年   28篇
  2015年   21篇
  2014年   29篇
  2013年   43篇
  2012年   57篇
  2011年   80篇
  2010年   26篇
  2009年   45篇
  2008年   56篇
  2007年   67篇
  2006年   46篇
  2005年   50篇
  2004年   48篇
  2003年   40篇
  2002年   53篇
  2001年   10篇
  2000年   4篇
  1999年   9篇
  1998年   14篇
  1997年   6篇
  1996年   3篇
  1995年   7篇
  1994年   2篇
  1993年   5篇
  1992年   3篇
  1991年   8篇
  1990年   4篇
  1989年   5篇
  1988年   4篇
  1987年   4篇
  1986年   2篇
  1985年   5篇
  1984年   3篇
  1983年   2篇
  1982年   3篇
  1981年   3篇
  1980年   3篇
  1979年   4篇
  1978年   5篇
  1977年   1篇
  1975年   1篇
  1964年   1篇
  1963年   1篇
排序方式: 共有930条查询结果,搜索用时 187 毫秒
1.
Thirty-seven HIV-infected homosexual men with thrombocytopenia (less than 100 x 10(9)/l) received protein A immunoadsorption treatments to remove platelet-sensitizing immunoglobulin (Ig) G and circulating immune complexes (CIC) from plasma. Patients received an average of six treatments each, consisting of 250 ml plasma over a 3-week period. Clinical improvement in hemorrhagic symptoms associated with substantial increase in platelet counts was achieved in 18 patients. These responses were maintained over a median follow-up period of more than 7 months in 14 evaluable patients who were not lost to follow-up (three patients relapsed in 2 weeks and one received another therapy). Generally, moderate transient treatment-related side-effects included fever, musculoskeletal pain, chills and nausea. A transient serum sickness-like reaction was observed in seven patients, leading to termination of treatment in two. Clinical responses were associated with significant decreases in levels of platelet-sensitizing Ig, including CIC. Stimulation of broadly cross-reactive anti-antigen-binding fragment [F(ab)2], antibodies contributed to these responses. Protein A immunoadsorption is an effective alternative treatment for HIV-associated thrombocytopenia.  相似文献   
2.
The purpose was to measure the effects of postchemotherapy nausea and vomiting (PCNV) on health-related quality of life (HQL) in patients receiving either moderately or highly emetogenic chemotherapy. The study sample consisted of 832 chemotherapy-naive patients with cancer who received either moderately or highly emetogenic chemotherapy as part of multicenter trials of new antiemetics. The patients completed the self-report European Organization for Research and Cancer (EORTC) core Quality of Life Questionnaire (QLQ-C30) before chemotherapy (baseline) and 1 week (day 8) and 2–4 weeks after chemotherapy. They also completed a self-report nausea and vomiting (NV) diary for 5–7 days after chemotherapy. To determine the effects of PCNV on HQL, the change in scores between the baseline and day 8 HQL assessments was calculated for each domain and symptom in the QLQ-C30 and compared in four subgroups of patients: those with both nausea and vomiting, those with nausea but no vomiting, those with no nausea but with vomiting, and those with neither nausea nor vomiting. The group with both nausea and vomiting showed statistically significantly worse physical, cognitive and social functioning, global quality of life, fatigue, anorexia, insomnia and dyspnea as compared to the group with neither nausea nor vomiting (0.0001<P<0.05). Patients with only nausea but no vomiting tended to have less worsening in functioning and symptoms than those having both nausea and vomiting. Increased severity of vomiting (>2 episodes) was associated with worsening of only global quality of life and anorexia as compared with 1–2 episodes of vomiting (0.0001<P<0.01). By 2–4 weeks after chemotherapy all HQL scores had either returned to their baseline levels or were better than baseline. PCNV adversely affects several quality-of-life domains, but patients with only nausea experience less disruption than do those with both nausea and vomiting. Patients with 1–2 episodes of vomiting experience almost the same degree of disruption of HQL as do patients with more than 2 episodes of vomiting.  相似文献   
3.
The material consists of a series of 73 patients with squamous cell carcinoma of the vulva. The site and the size of the primary tumor and the histological status of the lymph nodes of the groin were known. Two pathologists evaluated nuclear hyperchromatism, nuclear polymorphism, histological differentiation, number of mitoses, inflammatory response, and vascular invasion and graded these parameters from one to three. The reliability of the histopathological grades evaluated by the κ coefficient showed considerable interobserver variation. Despite this a model which included the subjective parameter nuclear hyperchromatism could predict patients without lymph node metastases. The model consisted of patients with tumors which were not situated on the clitoris, were less than 40 mm in diameter, and exhibited only slight hyperchromatism. The model fitted 19 (26%) and 14 (19%) of the patients with two different pathologists evaluating the nuclear hyperchromatism and none of these patients had lymph node metastases. The quantitative parameter—mean nuclear volume—determined by morphometry was of no diagnostic value for the prediction of patients without groin node metastases at the time of operation.  相似文献   
4.
H. Zola    H. A. Moore    I. K. Hunter    A. Hohmann    P. J. Mcnamara    J. Bradley    P. Mum    A. Morley    J. V. Melo  D. Catovsky 《Tissue antigens》1985,26(1):60-70
FMC3 and FMC29 are monoclonal antibodies which react with a 30,000 Dalton molecule expressed on the lymphocyte surface membrane. The molecule is a protein which does not appear to be N-glycosylated. The antigen, which is also expressed intracellularly, does not appear to be a marker of differentiation or maturation. Polyclonal cell populations, such as peripheral blood lymphocytes, show a bimodal distribution of surface antigen density, whilst monoclonal cell populations analysed quantitatively showed unimodal antigen density distributions. This suggests the antigen may be a clonal marker.  相似文献   
5.
ISSUE: Inadequate pain management is a serious public health problem that affects a wide cross-section of Americans. Patients are often denied sufficient medication, because physicians lack training and fear scrutiny from federal and state regulatory agencies. In addition, even the state-financed system of care, Medicaid, has been increasingly denying payment for the best treatment for pain management. These factors are complicated by physician bias about various subgroups and poor physician-patient communication. Comprehensive patient assessment plays a crucial role in determining appropriate treatment and identifying potential abuse problems. Physicians must routinely document medications analgesic effects and screen for potential ill effects and drug abuse. OBJECTIVE: To examine the prevalence of the undertreatment of pain, particularly among African Americans, and to recommend relevant proactive policy and practice changes to aid in eliminating this health problem. CONSENSUS PROCESS: In July 2002, the NMA convened the "Managing Pain: The Challenge in Underserved Populations: Appropriate Use versus Abuse and Diversion" Consensus Meeting in Washington, DC. The country's most renowned experts in the area of pain management and substance abuse reviewed substantial information regarding pain management and substance abuse including the following: --A draft summary paper on pain management and substance abuse that served as briefing material for consensus members; --Annotated bibliographies; --Articles on pain management and substance abuse; and --Key presentations on pain management and substance abuse.  相似文献   
6.
BACKGROUND CONTEXTRevision risk after pediatric spine surgery is not well established and varies between deformity etiologies.PURPOSETo report the 2-year revision risk following surgery for primary pediatric spinal deformity in a nationwide cohort and to evaluate potential risk factors and reasons for revision surgery.DESIGNRetrospective nationwide cohort study.PATIENT SAMPLEA national registry study of all pediatric spinal deformity patients undergoing surgery during 2006–2015 (n=1310).OUTCOME MEASURESTwo-year revision risk.METHODSAll patients ≤21 years of age undergoing spinal deformity surgery in Denmark during 2006–2015 were identified by procedure and diagnosis codes in the Danish National Patient Registry (DNPR). Data on revision surgery were retrieved from the DNPR. Patients were categorized in six groups according to etiology. Medical records were reviewed for reason for revision in all patients. Potential risk factors for revision were assessed with multiple logistic regression analyses and included age, etiology, sex, Charlson comorbidity index (CCI), and growth-preserving treatment.RESULTSPatients were categorized according to etiology: idiopathic deformity (53%), neuromuscular deformity (23%), congenital/structural deformity (9%), spondylolisthesis (7%), Scheuermann's kyphosis (5%), and syndromic deformity (3%). Of 1,310 included patients, 9.2% underwent revision surgery within 2 years and 1.5% was revised more than once. Median time to revision was 203 (interquartile range 35–485) days. The multivariable logistic regression found significantly higher odds ratio (OR) for revision in patients with growth-preserving treatment (OR=5.1, 95% confidence interval [CI] 2.6–10.1), congenital deformity (OR=2.7, 95% CI 1.3–5.3), spondylolisthesis (OR=3.5, 95% CI 1.9–6.7), Scheuermann kyphosis (OR=3.9, 95% CI 1.9–8.3), and CCI score ≥3 (OR=2.5 95% CI 1.1–5.6). The most common reason for revision was implant failure (32.5%) followed by residual deformity and/or curve progression (15.8%).CONCLUSIONSIn this nationwide study, the 2-year revision risk after primary pediatric spinal deformity surgery is 9.2%. Risk factors for revision are etiology of congenital deformity, spondylolisthesis, Scheuermann kyphosis as well as patients with growth-preserving treatment and higher CCI. The most common reason for revision is implant failure.  相似文献   
7.
PURPOSE: For cancer patients receiving cytotoxic chemotherapy, hepatitis B virus (HBV) reactivation is a well described complication resulting in varying degrees of liver damage. The objectives of this study were to assess the efficacy of the antiviral agent lamivudine in reducing the incidence of HBV reactivation and diminishing morbidity and mortality of cancer patients with chronic HBV infection during chemotherapy. PATIENTS AND METHODS: Two groups were compared in this nonrandomized study. The prophylactic lamivudine group consisted of 65 patients in a phase II study who were treated with lamivudine before and until 8 weeks after discontinuing chemotherapy. The historical controls consisted of 193 consecutive patients who underwent chemotherapy without prophylactic lamivudine. Significant prognosticators for the development of HBV reactivation were determined based on data from the controls. Potential confounding factors were identified between the two groups. The outcomes were compared. RESULTS: In the controls, lymphoma and anthracycline usage were factors identified to be associated with reactivation. The two groups were comparable in most baseline characteristics, although in the prophylactic lamivudine group, there were significantly more patients with lymphoma and receiving anthracyclines. In the prophylactic lamivudine group, there was significantly less HBV reactivation (4.6% v 24.4% in the controls; P <.001), fewer incidences of hepatitis (17.5% v 44.6%; P <.0001) that were less severe (4.8% v 18.7%; P =.0005), and less disruption of chemotherapy (15.4% v 34.6%; P =.0029). The reduction in overall mortality was not statistically different. CONCLUSION: Prophylactic lamivudine significantly reduced the incidence of HBV reactivation and the overall morbidity of cancer patients undergoing chemotherapy.  相似文献   
8.
PURPOSE: To assess the efficacy of neoadjuvant paclitaxel and carboplatin (TC) followed by concurrent cisplatin and radiotherapy (RT) in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) and to monitor treatment response with plasma Epstein-Barr virus (EBV) DNA. PATIENTS AND METHODS: Thirty-one patients with International Union Against Cancer stages III and IV undifferentiated NPC had two cycles of paclitaxel (70 mg/m2 on days 1, 8, and 15) and carboplatin (area under the curve 6 mg/mL/min on day 1) on a 3-weekly cycle, followed by 6 to 8 weeks of cisplatin (40 mg/m2 weekly) and RT at 66 Gy in 2-Gy fractions. Plasma EBV DNA was measured serially using the real-time quantitative polymerase chain reaction method. Results All patients completed planned treatment. Response to neoadjuvant TC was as follows: 12 patients (39%) achieved partial response (PR) and 18 achieved (58%) complete response (CR) in regional nodes; five patients (16%) achieved PR and no patients achieved CR in nasopharynx. At 6 weeks after RT, one patient (3%) achieved PR and 30 patients (97%) achieved CR in regional nodes, and 31 patients (100%) achieved CR in nasopharynx; 29 patients (93%) had EBV DNA level of less than 500 copies/mL. Neoadjuvant TC was well tolerated, and the most common acute toxicity of cisplatin plus RT was grade 3 mucositis (55%). At median follow-up of 33.7 months (range, 7 to 39.3 months), six distant and three locoregional failures occurred. Plasma EBV DNA level increased significantly in eight of nine patients who experienced treatment failure but did not increase in those who did not. The 2-year overall and progression-free survival rates were 91.8% and 78.5%, respectively. CONCLUSION This strategy was feasible and resulted in excellent local tumor control. Serial plasma EBV DNA provides a noninvasive method of monitoring response in NPC.  相似文献   
9.
Background: Clearance of large molecules from the interstitialspace is an important function of lymphatics andis affected by local pathologic changes.Objective: To determine if the clearance rate ofinterstitially injected albumin is correlated to tumour characteristicsand outcome in women with invasive breast cancer.Method: In a consecutive series of women comingto biopsy for suspected breast cancer, technetium-tagged albuminwas injected into the tissue adjacent to thepalpable mass. The isotope disappearance rate was measuredover two hours. Also assessed were the maximumvessel density (MVD – using Factor VIII polyclonalantisera), the proliferation rate (using Ki-67 antisera), nodestatus, tumour size, histologic and nuclear grade, mitoticrate, and p53 and c-erbB-2 oncoproteins. All patientswere followed until relapse and for a minimumof 10 years.Results: In multivariate analysis, an association between relapse-freesurvival and isotope clearance rate was suggested (p= 0.024). The best outcome was seen inpatients with the least isotope clearance. Node status,size, histologic and nuclear grade, and mitotic ratecorrelated with survival. MVD did not correlate withsurvival and was inversely related to the isotopeclearance rate. Tumour proliferation rate, and the c-erbB-2and p53 oncoproteins did not relate to outcome.Conclusion: The role of lymphatics in breast canceris difficult to study. Measurement of interstitial clearancemay be a useful technique and could bea prognostic factor.  相似文献   
10.
Excessive use of smartphones or other electronic screen products and the associated symptoms of addiction among youngsters have sparked concerns. This study explores possibilities of preventing adolescents or young adults from excessive smartphone use via a character-based mobile application stimulating their imagination and reflection. The character responds contingently to a user’s act of switching on or off the screen, causing one to associate the effects on the character with excessive use. This approach, grounded in the embodied cognition thesis, combines behavior with imaginative consequences for one to experience, which combat the rewarding neural pathways activated in addictive behaviors. The application was deployed in a field trial. Each participant’s usage was tracked via automated logging, and cognitive responses were probed through in-depth interviews. Interview data were analyzed, followed by comparison with logged data. Overall, about half of the participants attributed imaginative consequences to their ways of using phones. One third of the participants showed evidence of positive change in using phones. These two groups substantially overlapped. The results suggest that experientially grounded association of virtual consequences with physical acts could correlate with behavior change. Using figurative representation as feedback could be promising in supporting individuals for healthy habits.  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