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   939篇
  免费   54篇
耳鼻咽喉   9篇
儿科学   81篇
妇产科学   8篇
基础医学   104篇
口腔科学   10篇
临床医学   90篇
内科学   195篇
皮肤病学   12篇
神经病学   72篇
特种医学   94篇
外科学   130篇
综合类   2篇
预防医学   48篇
眼科学   3篇
药学   35篇
中国医学   1篇
肿瘤学   99篇
  2023年   7篇
  2022年   5篇
  2021年   18篇
  2020年   12篇
  2019年   19篇
  2018年   17篇
  2017年   32篇
  2016年   28篇
  2015年   28篇
  2014年   28篇
  2013年   36篇
  2012年   40篇
  2011年   49篇
  2010年   25篇
  2009年   24篇
  2008年   45篇
  2007年   33篇
  2006年   38篇
  2005年   41篇
  2004年   39篇
  2003年   33篇
  2002年   24篇
  2001年   49篇
  2000年   37篇
  1999年   30篇
  1998年   5篇
  1997年   9篇
  1996年   10篇
  1995年   9篇
  1994年   4篇
  1993年   9篇
  1992年   15篇
  1991年   18篇
  1990年   21篇
  1989年   26篇
  1988年   13篇
  1987年   14篇
  1986年   14篇
  1985年   10篇
  1984年   14篇
  1983年   6篇
  1982年   7篇
  1981年   4篇
  1979年   4篇
  1975年   3篇
  1974年   4篇
  1973年   10篇
  1971年   4篇
  1938年   2篇
  1937年   2篇
排序方式: 共有993条查询结果,搜索用时 15 毫秒
1.
2.
3.
I characterize the different facettes of the psychodynamics of sexual abuse in psychotherapy by the Karpmann (or drama) triangel. This model of relationship helps to understand better the process of role play between victim, perpetrator, and prosecuter and the hereby provoked change of roles.  相似文献   
4.
The right gastroepiploic artery (GEA) was used as a pedicled conduit for direct coronary artery revascularization in 20 patients presenting with more or less exhausted saphenous vein resources. The early angiographic patency of the GEA conduit appears to be satisfactory when it is connected to the right coronary artery system. A distinct disadvantage of GEA grafting is the necessity to enter the abdominal cavity, which may lead to probably rare and as yet unrecognized morbidity. Future abdominal surgery may injure the GEA conduit unless its topographic relations to the prepyloric antrum, liver and diaphragm are properly recognized. The surgeon must then be prepared to encounter antegastric, retrogastric, antehepatic, transhepatic and retrohepatic routes of the redirected intraabdominal artery. The present paper addresses this problem. Preoperative angiography of the celiac trunk and superior mesenteric artery may be helpful in decision-making when a patient reports or records show that a graft has been harvested from the abdominal cavity.  相似文献   
5.
H Knispel  K P Dieckmann  G Henze  V Loy 《Der Urologe. Ausg. A》1990,29(4):226-9; discussion 213-4
A rare case of metastatic nephroblastoma on the right side in a 28-year-old female patient is presented. Complete remission was achieved by inductive chemotherapy with vincristine, Adriamycin, actinomycin D and cyclophosphamide and subsequent radical nephrectomy. There was no evidence of disease 24 months after the initial diagnosis had been made. The problems specific to the diagnosis and treatment of adult Wilms tumor are discussed. A chemotherapy regimen known to be successful in childhood Wilms tumor was shown to be equally effective in our adult patient.  相似文献   
6.
The exact regional correlation of findings of facial bone scans, planar or SPECT, to dental orthopan X-ray films (OPT) is difficult because of the very different projection techniques. To improve correlative imaging in this regard a projection algorithm was developed that uses SPECT data of the skull for reconstructing an orthopan tomoscintigraphic projection. Fourteen conventional SPECT slices of the upper and lower jaws were obtained during bone scanning. All mandibular slices were superimposed resulting in a horseshoe shaped structure, which was marked by an ROI which was divided into segments. All 14 SPECT slices were then masked by this segmental ROI, thereby marking the teeth-carrying bone in all slices. The information from this horseshoe like ROI is then transformed into lines. Line by line arrangement results in an orthopan projection, the orthopan tomoscintigram. This new display allows 1:1 true scale superimposition with the X-ray OPT and markedly facilitates correlative imaging.  相似文献   
7.
In 40 patients (pts) (ages 34-83 years) the severity of tricuspid regurgitation (TR) was graded by pulsed Doppler echocardiographic determination of regurgitant jet extension. Mild TR was assessed in seven pts (group I), mode-rate TR in 20 pts (group II), and severe TR in 13 pts (group III). The enddiastolic diameter of the left ventricle as measured by M-mode-echocardiography was 55 +/- 16 mm in group I, 48 +/- 6 mm in group II, and 50 +/- 10 mm in group III. The regurgitant index (RI), i.e., the ratio of left-to-right-ventricular stroke counts (normal range 0.89-1.97) and the time-activity curve over the liver area were measured by equilibrium radionuclide ventriculography (RNV). The RI differed significantly between group I (1.6 +/- 0.5), II (1.0 +/- 0.3), and III (0.8 +/- 0.3) (p less than 0.01). An RI-value below 0.89 as an index of right-ventricular volume overload was found in 14% (group I), 45%, (group II) and 77% (group III). The time-activity curve over the liver area, as graded by count variation in phase with the right atrium from 1 (no count variation) to 4 (typical count variation) showed all grades in groups I and II, but only grade 2 to 4 in group III. The RI resp. the time-activity curve over the liver is a sensitive parameter for the detection of moderate to severe TR. If TR is ascertained, severe regurgitation can be differentiated from mild regurgitation by RNV-derived RI as an index of right-ventricular volume overload.  相似文献   
8.
Myocardial scanning (MS) and radionuclide ventriculography (RNV) are the foundation of nuclear cardiology. These procedures aim in two completely different directions: RNV tries to image heart motion, that is, mechanical (pump) function, and therefore belongs to the group of first-order functional imaging (FI, imaging mechanical function), whereas MS is based on myocardial metabolism, and therefore can be attributed to third-order functional imaging (metabolism). This statement is relevant for the assessment of the clinical position of RNV: Third-order (metabolism) functional imaging is the domain of nuclear medicine (NM), whereas first-order FI has to face the competition of alternative noninvasive procedures such as ultrasound (US), digital subtraction angiography (DSA), computer tomography (CT), and nuclear magnetic resonance (NMR). The domain of RNV includes stages two (acute infarction) and three (postinfarction period) of coronary arterial disease (CAD). The advantageous combination of quantitative data on global, left ventricular (LV) function and imaging of regional motion ensures the superiority of RNV over US. However, RNV is inferior to MS in physical examinations in the preinfarction stage of CAD, whereas US is clearly inferior to both NM procedures. Recent progress could be attained by gated SPECT (GASPECT). A proposal is presented for simplification of this time-consuming procedure. Technetium-labeled isonitriles offer the chance for the combination of perfusion-motion imaging of the myocardium. However, even standard RNV offers new possibilities. The multitude of parameters produced by quantitation has not yet been exploited completely. This can be done by discriminant analysis. The computer finds out an optimal subset from the whole set of parameters for the solution of a significant clinical problem. The software learns to find the label of a special pathognomonic entity. This computer work is supported by a relational data bank (Oracle) and an optical disk. Two examples for the effectiveness of the computer in problem solving are presented. It is concluded that RNV, even in the very competitive class of first-order functional imaging, enjoys a preferred position. The future indeed seems brighter because labeled isonitriles offer the chance for the combination of perfusion-motion imaging of the myocardium.Dedicated to Prof. Heinz Hundeshagen on the occasion of his 60th birthday  相似文献   
9.
Summary In patients with varying degrees of chronic obstructive pulmonary disease (COPD), simultaneous measurements of central hemodynamics and left ventricular radionuclide ventriculograms at rest and during exercise were made. In 21 of these patients, satisfactory echocardiograms could be performed. In seven of the patients, arterial blood pressure at rest was increased. Decreased compliance of the left ventricle was thought to be present in patients with COPD and additional arterial hypertension. The left ventricular ejection fraction (LVEF) at rest was in the high normal range in all patients. During exercise, no further increase was observed. This pattern of LVEF response seems to be typical in patients with COPD. Because the highest values were observed in the more severe COPD and right ventricular hypertrophy, it is unlikely that an impairment of left ventricular function is caused by COPD. In five of 27 patients, an abnormal decrease of LVEF and regional hypokinesis occurred during exercise, thus suggesting additional coronary heart disease. The fact that at least 30% of the patients with COPD suffered from arterial hypertension and 20% of the patients exhibited unexpected ischemia detected by regional hypokinesis in RNV during exercise, but not in the ECG, may be of practical relevance. Coronary angiography was not indicated because most of these patients were over 65 and the factor limiting the working capacity was ventilatory impairment and not angina pectoris, in all patients. For this reason, a diagnostic uncertainty remains with regard to additional coronary heart disease in the older patients with advanced chronic obstructive pulmonary disease.Lung Function Parameters VC (1) inspiratory vital capacity - FEV1 (1) forced exspiratory volume in 1 sec - Raw (cmH20/l/s) airways resistance - RV/TLC (%) residual volume/total lung capacity - paO2 (mm Hg) O2 partial pressure Hemodynamic Parameters CI (1/min/sqm) cardiac index - SVI (ml/sqm) stroke volume index - PAP (mm Hg) pulmonary artery mean pressure - PwP (mm Hg) pulmonary capillary wedge pressure - RRs (mm Hg) systolic arterial pressure - RRd (mm Hg) diastolic arterial pressure (at the time of catheterization) - RR(WHO) (mm Hg) mean values measured at different days (at least 3 values). Parameters Derived from Combined Radionuclide Ventriculography and Central Hemodynamics LVEF (%) left ventricular ejection fraction - LVESVI (ml/sqm) left ventricular endsystolic volume index - P/V (mm Hg/ml/sqm) peak systolic pressure/endsystolic volume index - PFR (1/sec) peak filling rate: endsystolic volume/sec Echocardiographic Parameters RV d wth (mm) right ventricular enddiastolic wall thickness - LV d wth (mm) left ventricular enddiastolic wall thickness In honor to Prof. W.E. Adam's 60th birthday  相似文献   
10.
Summary Simultaneous right heart catheterization and radionuclide ventriculography were performed in 27 patients with a wide range of chronic obstructive pulmonary disease. Central hemodynamics and radionuclide studies were done at rest and during exercise. In the resting state the right ventricular ejection fraction (RVEF) was in the normal range (43.3±6%). During exercise a significant (p<0.001) decrease of RVEF to 38.8±6.7% occurred. The pumonary artery mean pressures were 19.9±3.8 at rest. During exercise a significant (p<0.001) increase to 41±9.8 mm Hg occurred. There was a linear relationship between pulmonary pressures and RVEF during exercise in patients with pulmonary artery pressures not exceeding 35 mm Hg. In patients with right ventricular end-diastolic wall thickness 6 mm a curvilinear relationship between these parameters could be observed with a flattening of the curve at higher pressures (>35 mm Hg) and lower ejection fractions (<35% RVEF). Radionuclide venticulography cannot substitute for right heart catheterization. Echocardiography is useful for interpretation of right ventricular ejection fractions in advanced chronic obstructive pulmonary disease.Abbreviations CI Cardiac index (l/min/m2) - CO Cardiac output (l/min) - COPD Chronic obstructive pulmonary disease - FEV1 Forced expiratory volume in the first second (ml) - HR Heart rate (B/min) - PAd Pulmonary artery diastolic pressure (mm Hg) - PAP Pulmonary artery mean pressure (mm Hg) - PAs Pulmonary artery peak pressure (mm Hg) - PVR Pulmonary vascular resistance (dyn·s·cm–5) - PwP Pulmonary capillary wedge pressure (mm Hg) - RAP Right arterial pressure (mm Hg) - Raw Airway resistance (cm H2/l/s) - RNV Radionuclide ventriculogram - RV Residual volume (l) - RVEF Right ventricular ejection fraction (%) - RVEDVI Right ventricular enddiastolic volume index (ml/m2) - RVEDVI SVI RVEF (ml/m2) - RVESVI Right ventricular endsystolic index (m2/m2) - SVI Stroke volume index (ml/m2) - TLC Total lung capacity (l) - VC Vital capacity (l)  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