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   673篇
  免费   21篇
  国内免费   18篇
耳鼻咽喉   1篇
儿科学   44篇
妇产科学   6篇
基础医学   58篇
口腔科学   14篇
临床医学   83篇
内科学   146篇
皮肤病学   7篇
神经病学   36篇
特种医学   104篇
外科学   77篇
综合类   35篇
预防医学   44篇
眼科学   1篇
药学   32篇
中国医学   1篇
肿瘤学   23篇
  2022年   3篇
  2021年   11篇
  2020年   6篇
  2019年   6篇
  2018年   16篇
  2017年   5篇
  2016年   10篇
  2015年   16篇
  2014年   15篇
  2013年   20篇
  2012年   31篇
  2011年   24篇
  2010年   36篇
  2009年   25篇
  2008年   22篇
  2007年   33篇
  2006年   21篇
  2005年   15篇
  2004年   25篇
  2003年   16篇
  2002年   14篇
  2001年   10篇
  2000年   18篇
  1999年   22篇
  1998年   24篇
  1997年   27篇
  1996年   26篇
  1995年   20篇
  1994年   21篇
  1993年   16篇
  1992年   3篇
  1991年   8篇
  1990年   14篇
  1989年   26篇
  1988年   17篇
  1987年   13篇
  1986年   9篇
  1985年   8篇
  1984年   4篇
  1983年   9篇
  1982年   3篇
  1981年   8篇
  1980年   11篇
  1979年   2篇
  1978年   4篇
  1977年   3篇
  1976年   4篇
  1975年   2篇
  1971年   3篇
  1924年   1篇
排序方式: 共有712条查询结果,搜索用时 328 毫秒
1.
Sonoelasticity imaging of prostate cancer: in vitro results   总被引:2,自引:0,他引:2  
  相似文献   
2.
BACKGROUND AND OBJECTIVES: The purpose of this study was to determine patient recall and comprehension after laparoscopic appendectomy in an underserved population. Laparoscopic surgery can lead to diagnostic uncertainty secondary to poor recall and variable port placement. METHODS: After institutional review board approval, we identified a cohort of patients who underwent laparoscopic appendectomy from 2000 to 2004 at a single institution. We then attempted to contact the patients to conduct a 10-question telephone survey, which determined whether the patient spoke English or Spanish as a primary language, ethnicity, educational level, and questions about recall of perioperative events and diagnoses. If we could not reach the patient, we tried to call back on 2 different occasions. RESULTS: Between 2000 and 2004, 186 patients underwent laparoscopic appendectomy. Of these, 65% were Hispanic. We found that only 17% of these patients returned for a postoperative visit. Only 19.3% could be contacted by phone. Forty-seven percent of the patients contacted by phone spoke Spanish exclusively. Overall 92% of patients contacted knew what operation they had, and gave their correct diagnosis. CONCLUSIONS: The low percentage of patients available to follow-up makes this study statistically insignificant. However, we believe that fact in itself is important. In Southwestern states, we see a large migrant population. This highlights the need to communicate effectively with the patients at the time of surgery, which we speculate we did based on the percentage of patients that knew their diagnosis.  相似文献   
3.
Major Depressive Disorder (MDD) is among the most prevalent but underdiagnosed psychiatric disorders in persons with HIV infection. Given the known adverse impact of comorbid MDD on HIV disease progression and health‐related quality of life, it is important both for research and for efficient, effective clinical care, to validate existing screening measures that may discriminate between MDD and the somatic symptoms of HIV (such as fatigue). In the current study, we evaluated the concurrent predictive validity of the Profile of Mood States (POMS) Depression‐Dejection scale in detecting current MDD in 310 persons with HIV infection. The Structured Clinical Interview for DSM‐IV (SCID) diagnosis of MDD and the Cognitive‐Affective scale from the Beck Depression Inventory (BDI‐CA) served as comparative diagnostic and severity measures of depression, respectively. Results demonstrated that the POMS Depression‐Dejection scale accurately classified persons with and without MDD SCID diagnoses, with an overall hit rate of 80%, sensitivity of 55%, specificity of 84%, and negative predictive power of 91% using a recommended cutpoint of 1.5 standard deviations above the normative mean. Moreover, the POMS performed comparably to the BDI‐CA in classifying MDD. Findings support the predictive validity of the POMS Depression‐Dejection scale as a screening instrument for MDD in persons with HIV disease. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
4.
Screening for early ovarian cancer   总被引:5,自引:0,他引:5  
Taylor  KJ; Schwartz  PE 《Radiology》1994,192(1):1
  相似文献   
5.
Tumor vascular signals in renal masses: detection with Doppler US   总被引:3,自引:0,他引:3  
Ramos  IM; Taylor  KJ; Kier  R; Burns  PN; Snower  DP; Carter  D 《Radiology》1988,168(3):633-637
The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses.  相似文献   
6.
Susceptibility to multiple sclerosis (MS) is clearly associated with human leukocyte antigen (HLA)-DRB1*1501, but some studies show associations with HLA-B7 and -B18. These are often co-expressed with DRB1*1501 in the ancestral haplotypes (AH) denoted 7.1 (HLA-A3, B7, tumor necrosis factor [TNF]a11b4, DRB1*1501) and 18.1 (HLA-A25, B18, TNFa10b4, DRB1*1501). Here we present a systematic study of 218 patients and 274 controls typed at all standard class II and TNF microsatellite loci, and a novel non-synonymous polymorphism in the central major histocompatibility complex gene, inhibitor of κ B-like protein (IKBL). The C allele at IKBL+738 is only found on the 7.1 haplotype. HLA-DRB1*1501 was associated with disease, as expected. When subjects expressing DRB1*1501 were analyzed separately, TNFa11b4 and IKBL+738C were less common in the patients and, hence, mark an allele that mediates resistance which lies telomeric of IKBL.

TNFa10b4 and TNFa1b5 were more common in DRB1*1501 patients than in controls. These alleles have been associated with the 18.1 and 18.2 AH, respectively. Since no component of these haplotypes was an independent risk factor in this study, it appears likely that a gene linked to TNFa10b4 and TNFa1b5 modifies the effect of the susceptibility locus marked by HLA-DRB1*1501. Potential candidate genes telomeric of the TNF cluster are discussed.  相似文献   

7.
8.
In human in-vitro fertilization (IVF)-embryo transfer, the in-vitro culture environment differs from in-vivo conditions in that the oxygen concentration is higher, and in such conditions the mouse embryos show a higher concentration of reactive oxygen species (ROS) in simple culture media. ROS are believed to cause damage to cell membranes and DNA fragmentation in somatic cells. This study was conducted to ascertain the level of H2O2 concentration within embryos and the morphological features of cell damage induced by H2O2. A total of 62 human oocytes and embryos (31 fragmented, 15 non-fragmented embryos, 16 unfertilized oocytes) was obtained from the IVF-embryo transfer programme. The relative intensity of H2O2 concentrations within embryos was measured using 2',7'-dichlorodihydrofluorescein diacetate by Quanti cell 500 fluorescence imaging and DNA fragmentation was observed with transmission electron microscopy and an in-situ apoptosis detection kit. The H2O2 concentrations were significantly higher in fragmented embryos (72.21 +/- 9.62, mean +/- SEM) compared to non-fragmented embryos (31.30 +/- 3.50, P < 0.05) and unfertilized oocytes (30.75 +/- 2.67, P < 0.05). Apoptosis was observed only in fragmented embryos, and was absent in non-fragmented embryos. Electron microscopic findings confirmed apoptotic bodies and cytoplasmic condensation in the fragmented blastomeres. We conclude that there is a direct relationship between increased H2O2 concentration and apoptosis, and that further studies should be undertaken to confirm these findings.   相似文献   
9.
IntroductionWe aimed to evaluate the success of bladder neck injections of triamcinolone at the time of transurethral bladder neck incision (BNI) for prevention of recurrent vesicourethral anastomotic stenosis (VUAS) following prostate cancer treatment.MethodsThis is a retrospective cohort study examining patients with recurrent VUAS post-radical prostatectomy (RP) ± radiation treated with triamcinolone injections at the time of BNI. VUAS was diagnosed by symptoms followed by cystoscopy or urethrography. The outpatient procedures were done under general anesthesia. Cold knife incisions were made at the three, nine, and 12 o’clock BN positions, followed by triamcinolone injections (4 mg/mL) into the three and nine o’clock incision sites. Treatment outcomes were determined with cystoscopy.ResultsEighteen men underwent 25 procedures over a four-year period. Median age at diagnosis of VUAS was 65 (interquartile range [IQR] 61–68); median time to VUAS from RP was eight months (IQR 5–12). Fourteen patients (78%) had radiation treatment. The cohort had 128 unsuccessful VUAS treatments, with a median of five failed treatments per patient (IQR 3–10). Failed treatments included BN dilation, BNI, BN injection of mitomycin C, and urethral stent placement. Success rate after a mean of 16.3 months (standard deviation [SD] 8.1) from the time of triamcinolone injection was 83% (15/18). Six patients went on to have successful incontinence surgery. Five patients (28%) had treatment complications (bleeding, urinary tract infection, pain, and urinary extravasation). The three non-responders are stable and awaiting re-treatment with triamcinolone injection.ConclusionsTriamcinolone bladder neck injections for post-RP VUAS are a useful and safe treatment for recurrent stenosis.  相似文献   
10.
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