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   2570篇
  免费   73篇
  国内免费   19篇
耳鼻咽喉   31篇
儿科学   118篇
妇产科学   125篇
基础医学   177篇
口腔科学   93篇
临床医学   188篇
内科学   547篇
皮肤病学   80篇
神经病学   142篇
特种医学   138篇
外科学   554篇
综合类   42篇
预防医学   62篇
眼科学   119篇
药学   147篇
中国医学   4篇
肿瘤学   95篇
  2023年   8篇
  2022年   19篇
  2021年   36篇
  2020年   31篇
  2019年   42篇
  2018年   37篇
  2017年   36篇
  2016年   46篇
  2015年   45篇
  2014年   77篇
  2013年   94篇
  2012年   156篇
  2011年   155篇
  2010年   89篇
  2009年   79篇
  2008年   168篇
  2007年   235篇
  2006年   203篇
  2005年   227篇
  2004年   181篇
  2003年   142篇
  2002年   134篇
  2001年   75篇
  2000年   57篇
  1999年   57篇
  1998年   22篇
  1997年   21篇
  1996年   24篇
  1995年   12篇
  1994年   12篇
  1993年   15篇
  1992年   17篇
  1991年   10篇
  1990年   12篇
  1989年   15篇
  1988年   17篇
  1987年   10篇
  1986年   4篇
  1985年   9篇
  1984年   3篇
  1983年   3篇
  1982年   6篇
  1981年   2篇
  1980年   2篇
  1977年   2篇
  1975年   3篇
  1974年   3篇
  1972年   2篇
  1971年   2篇
  1967年   1篇
排序方式: 共有2662条查询结果,搜索用时 15 毫秒
101.

Objective

The aim of this study was to determine the alterations of walking energy expenditure and plantar pressure distribution in young adults with patellofemoral pain syndrome (PFPS).

Methods

Thirty five individuals (mean age: 21.31 ± 1.76) with PFPS constituted the patient group and forty healthy participants (mean age: 21.40 ± 2.11) the control group. Preferred walking speeds (PWS) were determined on the over ground. Individuals walked on a treadmill for 7 min at their PWS and 30% above PWS and oxygen consumption was recorded via a metabolic analyzer. Net oxygen consumption was calculated for each walking trial. Borg scale was applied to assess perceived exertion during walking trial. Plantar pressure distributions were measured by a pedobarography device. Plantar area was subdivided into six zones to evaluate the dynamic plantar pressure data.

Results

The mean PWS of PFPS and control groups were 4.69 ± 0.51 and 4.52 ± 0.60 km/h, respectively (p > .09). No significant difference was observed in energy expenditure during walking at PWS between 2 groups while oxygen consumption during 30% above PWS was higher in patient group (18.72 ± 3.75 and 16.64 ± 3.27) (p = .007). Net oxygen consumption was also found to be higher in PFPS group (15.12 ± 3.62 and 13.04 ± 3.24) (p = .005). The mean Borg scores were significantly higher in PFPS group at each walking trials (p < .001). No statistically significant difference was found between weight distribution (%) of symptomatic and nonsymptomatic extremity (50.45 ± 3.92% and 49.56 ± 3.93%, respectively) (p = .509). Dynamic pedobarography parameters were not different between 2 groups, and also between symptomatic and nonsymptomatic extremities (p > .05).

Conclusion

Although, rate of perceived exertion and energy expenditure during walking at 30% above PWS are affected negatively in young adults with PFPS, we may speculate that energy consumption and plantar pressure distribution can be compensated by a physiologic adaptation mechanism during walking at PWS.

Level of evidence

Level III, Therapeutic Study.  相似文献   
102.
Internal herniations through broad ligament defects are very rare. We present the first report of the triad of broad ligament defect, internal herniation of the caecum and appendicitis. A 36-year-old woman with phocomelia presented with right iliac fossa pain and vomiting. The patient had no previous history of trauma or surgery. Abdominal ultrasound showed a small amount of free fluid. At laparoscopy, bilateral broad ligament defects were found, with herniation of the caecum and an inflamed appendix through the right-sided defect. A laparoscopic salpingo-oophorectomy was required for reduction of the herniated bowel, and an appendicectomy was performed. Broad ligament defects may be congenital or acquired. In this case, in light of the limb abnormality and absence of previous surgery, a congenital aetiology is more likely. Ultrasound scan is not reliable and, although computed tomography may be of help, a diagnostic laparoscopy is the best investigation.  相似文献   
103.
Penile color Doppler sonography is a valuable method for evaluating erectile dysfunction. However, there are some concerns about the safety of this method due to the intracorporeal pharmacological injection, which may cause priapism as a complication, resulting in penile fibrosis. To evaluate the actual incidence of papaverine-induced priapism in patients with erectile dysfunction (ED) who underwent penile colour Doppler sonography and to determine the safety of this diagnostic tool, a retrospective study was conducted using the database of our institution. A total of 672 men with ED underwent penile color Doppler ultrasonography with the intracorporeal injection of 60 mg papaverine hydrochloride. The patient characteristics of priapism cases were retrospectively evaluated. Priapism in 18 of the 672 patients (2.68%) was successfully treated with blood aspiration, irrigation and injection of an α-agonist medication, when needed. Patients with priapism were younger compared with those without priapism; mean age 45 ± 12.51 (20–68) versus 50.93 ± 12.04 (17–78) ( P  < 0.001). Penile Doppler ultrasound is a safe procedure in evaluating erectile dysfunction. The incidence of priapism, which is the most important complication of this procedure, is low and can be managed successfully with conservative approaches.  相似文献   
104.
Infusions of large numbers (> 10(8)/kg) of donor leukocytes can induce remissions in patients with chronic myeloid leukemia (CML) who relapse after marrow transplantation. We wanted to determine if substantially lower numbers of donor leukocytes could induce remissions and, if so, whether this would reduce the 90% incidence of graft-versus-host disease (GVHD) associated with this therapy. Twenty-two patients with relapsed CML were studied: 2 in molecular relapse, 6 in cytogenetic relapse, 10 in chronic phase, and 4 in accelerated phase. Each patient received escalating doses of donor leukocytes at 4- to 33-week intervals. Leukocyte doses were calculated as T cells per kilogram of recipient weight. There were 8 dose levels between 1 x 10(5) and 5 x 10(8). Lineage-specific chimerism and residual leukemia detection were assessed using sensitive polymerase chain reaction (PCR) methodologies. Nineteen of the 22 patients achieved remission. Remissions were achieved at the following T-cell doses: 1 x 10(7) (n = 8), 5 x 10(7) (n = 4), 1 x 10(8) (n = 3), and 5 x 10(8) (n = 4). To date, 15 of the 17 evaluable patients have become BCR-ABL negative by PCR. The incidence of GVHD was correlated with the dose of T cells administered. Only 1 of the 8 patients who achieved remission at a T-cell dose of 1 x 10(7)/kg developed GVHD, whereas this complication developed in 8 of the 11 responders who received a T-cell dose of > or = 5 x 10(7)/kg. Three patients died in remission, 1 secondary to marrow aplasia, 1 of respiratory failure and 1 of complications of chronic GVHD. Sixteen patients who were mixed T-cell chimeras before treatment became full donor T-cell chimeras at the time of remission. Donor leukocytes with a T-cell content as low as 1 x 10(7)/kg can result in complete donor chimerism together with a potent graft-versus-leukemia (GVL) effect. The dose of donor leukocytes or T cells used may be important in determining both the GVL response and the incidence of GVHD. In many patients, this potent GVL effect can occur in the absence of clinical GVHD.  相似文献   
105.
No prior study to date has examined the comparisons of the structures that have been implicated in obsessive-compulsive disorder (OCD) in patients with refractory OCD, those who are treatment-responded and healthy controls concurrently. Therefore, we performed a volumetric MRI study in patients with refractory OCD, those with treatment responding OCD and healthy controls. Morphometric MRI was used to compare in thirty patients with OCD and ten healthy controls. Of the patient group, ten were first applying patients, ten were treatment-responded and the rest were refractory OCD patients. As a whole group, OCD patients had increased white matter volume than healthy controls. First applying patients had significantly smaller left and right orbito-frontal cortex (OFC) volumes compared with treatment-responded patients and healthy controls, with a significant difference between refractory patients and treatment-responded patients and with no significant difference was found between the volume of first applying patients compared to that of refractory patients. Anterior cingulate exhibited a near-significant difference only between first applying patients and healthy controls on left side. First applying patients had significantly greater left and right thalamus volumes compared with treatment-responded patients and healthy controls and there was a considerable difference in regard to thalamic volumes between refractory patients and treatment-responded patients. Taken together, our findings suggest that reductions in OFC and increase in thalamic volumes may be associated with refractoriness of OCD and may not be due to changes in cingulate and caudate regions.  相似文献   
106.
107.
108.
In this study, we sought to determine whether proteinuria after renal transplantation was associated with cardiovascular disease (CVD), patient survival, and long-term allograft survival. One hundred twenty-six patients included 102 males and 24 females of mean age 30.7 ± 8.9 years. Their mean follow-up was 63.21 ± 19.9 months. All patients were evaluated for CVD, namely, ischemic heart disease, cerebrovascular disease, and peripheral vascular disease. Proteinuria was defined as urinary protein ≥500 mg/d which persisted for >6 months after transplantation. We retrospectively examined pre- and posttransplant data, including sex, age at transplantation, smoking, pretransplant dialysis duration, donor status, number of acute rejection episodes, body mass index, systolic and diastolic blood pressure levels, lipid profile and other biochemical parameters, immunosuppressive regimens, as well as pulse steroid dose. Proteinuria was significantly associated with CVD (P = .001; RR = 6.43; confidence interval [CI] 2.15-19.22). Patients with proteinuria showed significantly lower graft survival rates than those without proteinuria (58.62% vs 80.41%; P = .02). The mean time to appearance of proteinuria was 14.1 ± 11.4 months (range, 1-36 months). There was no significant association between proteinuria and patient survival. Patients with persistent proteinuria displayed a greater number of acute rejection episodes (1.20 ± 1.17 vs 0.62 ± 0.85; P = .004) and higher pulse steroid dosages (4380.0 ± 3123.4 vs 2800.0 ± 2766.7; P = .022). In conclusion, persistent proteinuria is a strong risk factor for CVD among renal transplant patients. Therefore, an etiologic search and antiproteinuric strategy should be considered routinely to improve patient and graft outcomes.  相似文献   
109.
Although the adverse effect of admission hyperglycemia in cerebral infarction on prognosis is well known, studies generally have not questioned the effect of hyperglycemia in the early subacute period on prognosis after a stroke. Forty-six patients with acute ischemic stroke were seperated into 3 groups: Group 1) Known diabetes or admission blood glucose (ABG) > or = 140 mg/dl and HbA1c > or = 8,0%); Group 2) ABG > or = 140 mg/dl and HbA1c < 8,0%; and Group 3) ABG < 140 mg/dl and HbA1c < 8,0%. Blood glucose was followed-up 4 times a day for 10 days after the stroke and the mean of these measurements was calculated as the mean of glycemic regulation (MGR). Neurological evaluation was done at presentation and on day 10 and 30 with the National Institute of Health (NIH) scale. Oedema, lesion size and presence of hemorrhagic transformation were evaluated using CT. The MGR was significantly higher in group 1 compared to the other two groups (p < 0,001 and p < 0,01) and in group 2 compared to group 3 (p < 0,001). Patients with clinical worsening had a significantly higher MGR (p < 0,05). Patients with marked cerebral edema had a significantly higher MGR (p < 0,01) compared to patients with lesser edema. No correlation was found between MGR and lesion size or hemorrhagic transformation. Our results show that hyperglycemia in the early subacute period after cerebral infarction is associated with more pronounced cerebral edema and has an adverse effect on short term prognosis. We suggest that studies investigating the effect of insulin infusion on stroke prognosis should also consider infusions for a longer period than 24 hours.  相似文献   
110.
Friedreich's ataxia (FRDA), the most-common form of autosomal recessive ataxia, is inherited in most cases by a large expansion of a GAA triplet repeat in the first intron of the frataxin (X25) gene. Genetic heterogeneity in FRDA has been previously reported in typical FRDA families that do not link to the FRDA locus on chromosome 9q13. We report localization of a second FRDA locus (FRDA2) to chromosome 9p23-9p11, and we provide evidence for further genetic heterogeneity of the disease, in a family with the classic FRDA phenotype.  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