首页 | 官方网站   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   1084篇
  免费   31篇
  国内免费   8篇
医药卫生   1123篇
  2023年   4篇
  2022年   8篇
  2021年   17篇
  2020年   15篇
  2019年   19篇
  2018年   17篇
  2017年   27篇
  2016年   23篇
  2015年   28篇
  2014年   54篇
  2013年   65篇
  2012年   102篇
  2011年   110篇
  2010年   51篇
  2009年   51篇
  2008年   77篇
  2007年   70篇
  2006年   73篇
  2005年   67篇
  2004年   57篇
  2003年   71篇
  2002年   58篇
  2001年   16篇
  2000年   9篇
  1999年   9篇
  1998年   2篇
  1997年   8篇
  1996年   2篇
  1995年   2篇
  1992年   4篇
  1991年   3篇
  1990年   2篇
  1979年   1篇
  1974年   1篇
排序方式: 共有1123条查询结果,搜索用时 31 毫秒
101.
In this study, the potentially beneficial effects of preoperative treatment with glucose, insulin and potassium in a randomized series of 30 consecutive patients undergoing mitral valve replacement, who were in the third and fourth functional groups of the New York Heart Association scale, were investigated. Fifteen patients received glucose, insulin and potassium, and 15 patients received the same volume of normal saline. The characteristics of the groups did not differ. Papillary muscle-biopsy samples were obtained at the time of surgery and analysed for glycogen, both biochemically and histochemically. The clinical course of all patients was monitored closely during the first 24 hours after surgery. The patients receiving glucose, insulin and potassium had higher glycogen levels (43 +/- 13.54 micromol/g) (P < 0.001). In addition, they required less inotropic pharmacological support (scored by the Gradinac method), had fewer ventricular arrhythmias and exhibited improved haemodynamic indices: cardiac output increased (P < 0.025 to P < 0.005), while systemic vascular resistance decreased (P < 0.001). Pretreatment with glucose, insulin and potassium did not, however, affect the patients' postoperative wedge pressure and mortality. The results of this study suggest that glucose, insulin and potassium pretreatment may be beneficial in unfit patients undergoing mitral valve replacement.  相似文献   
102.
n = 40) or claudication (n= 17) were prospectively studied. At the time of revascularization, simultaneously acquired intraluminal pressure and blood flow waveforms were digitized at 200 Hz and subjected to Fourier transformation in near real-time. Input impedance was calculated at baseline (immediately after unclamping) and after stimulation with either papaverine or completion arteriography. Resistance (R in) was calculated as mean pressure divided by mean blood flow (Q). Characteristic impedance (Z 0) was calculated as the mean of harmonics 3–10. Intraoperative data acquisition required approximately 5 min, utilized the completion angiography cannula already in place, and was uncomplicated in all patients. Stimulation with either papaverine or arteriography resulted in increased Q (72 ± 7 to 146 ± 11 ml/min, p < 0.001), decreased R in (126 ± 13 to 52 ± 4 × 103 dyne · s · cm−5, p < 0.001), and slightly decreased Z 0 (18 ± 2 to 15 ± 1, p = 0.002). After a mean follow-up of 20 months, the 2-year primary patency, secondary patency, limb salvage, and survival rates were 61 ± 8%, 74 ± 7%, 76 ± 6%, and 86 ± 6%, respectively. Primary patency was not associated with any of the clinical variables studied including age, sex, smoking history, history of previous vascular surgery, hypertension, coronary artery disease, diabetes mellitus, creatinine, indication for revascularization (claudication versus limb salvage), anesthesia (general versus regional), or level of distal anastomosis (popliteal versus infrapopliteal). Furthermore, there was no association between primary patency and baseline Q, baseline R in, or stimulated Z 0. However, using univariate analysis, patency was positively associated with decreased stimulated R in (p= 0.002), elevated stimulated Q (p= 0.006), and decreased baseline Z 0 (p= 0.02). Multiple regression analysis identified stimulated R in as the only independent predictor of primary patency (p= 0.002). Stimulated R in≥ 50 × 103 dyne · s · cm−5 was 71% sensitive and 65% specific for graft failure. It is concluded that 1) vascular input impedance can be simply and reliably measured in the operating room, and 2) elevated stimulated R in is an independent predictor of primary patency.  相似文献   
103.
Due to low back pain (LBP) and harmful effects of flying, questionnaires were sent to 71 helicopter pilots of the experimental group, 22 mechanics helicopter flyers and to the control group of 28 air-traffic controllers. The prevalence of LBP was the highest in helicopter pilots, then in helicomechanics and air-traffic controllers (53%, 50% and 36%). Effects of exposure to vibration, body posture and working load have not contributed significantly to the occurrence of LBP. LBP has not lead to an important difference in the strength of the back musculature, body mass index and spondylosis, that is, scoliosis. The necessity of further study of LBP and maintaining of specific preventive measures are indicated.  相似文献   
104.
OBJECTIVE: To assess the efficacy of paracetamol in comparison with diclofenac sodium. METHODS: Between February - November 2006, a prospective, double blinded, parallel group study of 100 patients suffering from first or second degree lateral ankle sprain within 48-hours of admission in Tepecik Education and Research Hospital, Izmir, Turkey. Patients with bilateral injury, ipsilateral knee injury, third degree sprain, previous sprain within 6 months, and ankle pain less than 45 according to visual analogue score (VAS) were excluded. Patients rated pain on a 100 VAS, representing 0 no pain, 100 maximal pain. After enrollment, patients were randomized (1:1) with diclofenac sodium 150 mg/day or paracetamol 1500 mg/day for 5 days. Clinical assessments were carried out at baseline; on second, tenth days, and sixth week (end of study). In each visit, VAS and adverse effects of medication were questioned. RESULTS: The mean VAS of the diclofenac group was 81 and 82.3 with paracetamol group at the first visit. These scores decreased to 20.7, 9.9, 4.6 in diclofenac group and 11.9, 6.3, 3 in paracetamol group at the second, tenth days and last examination. Similar reductions in pain were observed at the end of study (p>0.05) in both groups. However, cases treated by paracetamol group showed accelerated decrease in VAS at day 2 and 10 in comparison with diclofenac group (p<0.05). Of the ankle range of motion, there was a similar improvement in both groups (39.6 degrees, 37.5 degrees) (p>0.05). The incidence of gastrointestinal adverse effects on diclofenac group was much more than the paracetamol group, however, there was no significant difference (p>0.05). CONCLUSION: It was concluded that diclofenac sodium and paracetamol are effective and well tolerated as a short term treatment alternatives for acute ankle injuries.  相似文献   
105.
OBJECTIVE: To evaluate the Humphrey visual field parameters in patients with pituitary adenoma and classify the visual field defects in this patient group. METHODS: Forty primary pituitary adenoma patients underwent neuro-ophthalmological examination and Humphrey Perimetry 30-2 visual field test at Baskent University, Departments of Ophthalmology, and Neurosurgery, between 2003 and 2005. Global indices, mean+/-SD and pattern standard deviation (PSD) of pituitary adenoma patients (group 1) were taken as the test parameters and compared with age- and sex- matched controls (group 2). RESULTS: There were no significant differences between groups 1 and 2 with respect to mean age or gender distribution (p>0.05). The MD and PSD results of group 1 according to the age groups and gender were not statistically significant (p>0.05). The MD and PSD results of subjects in group 2 were within normal limits, and no special visual field defects were observed. When compared with healthy controls, the MD and PSD values of patients with hypophyseal adenomas were statistically significantly (p<0.05). In group 1, the mean adenoma size was 13.34 mm and no statistically significant correlation was found between the adenoma size and either the MD or PSD values (p>0.05). Sixteen (40%) patients had visual field defects, the specific complete bitemporal hemianopsia was found in 5 (12.5%) patients. Only in 3 patients (7.5%) the primary diagnosis was made by ophthalmologic examination. CONCLUSION: Although ophthalmologists rarely have a role in the primary diagnosis of hypophyseal adenoma, routine ophthalmologic examination is still important. To detect early visual field abnormalities, automated perimetry should be performed as a part of routine examination in patients with suspected hypophyseal adenomas.  相似文献   
106.
107.
108.
Availability and utilization of computed tomography angiography has been increasing recently. We aimed to assess the effectiveness of low amount of contrast media and low kV value in order to reduce possible side effects of contrast media and to provide optimization of kV value in the evaluation of the carotid artery with multi-detector computed tomography angiography. Forty one patients were randomized into two groups. Contrast media was administered at a dose of 1 ml/kg in group A patients and of 0.5 ml/kg in group B patients. kV value of 120 in group A and 100 in group B were chosen. Bolus tracking technique was used. Attenuation values of certain arterial segments were measured, and values over 200 HU were considered as significant. North American Symptomatic Carotid Endartherectomy Trial criteria were utilized in the evaluation of stenosis. Image quality in arterial segments of all cases was found to be sufficient for diagnosis. Arterial attenuation values were found to be higher in group B than group A. When compared separately in all arterial segments, there was no statistically significant difference between the groups. For stenosis, 615 arterial segments were evaluated. Moderate stenosis in eight segments and severe stenosis in three segments were identified in group A. Occlusion in three segments, severe stenosis in three segments, and moderate stenosis in 25 segments were detected in group B. Better image quality can be obtained, and the amount of contrast media can be reduced using low kV technique in carotid artery multi-detector computed tomography angiography examination.  相似文献   
109.
PurposeWe aimed to compare the efficacy of three different parathyroid adenoma screening tools—high-resolution ultrasonography (USG), technetium Tc 99m-methoxyisobutylisonitrile (MIBI) parathyroid scintigraphy, and magnetic resonance imaging (MRI)—and we evaluated the factors affecting the detection success rates.MethodsParathyroid imaging was evaluated by USG, double-phase 99mTc-MIBI parathyroid scintigraphy, and cervical MRI in patients with hyperparathyroidism (n=39).ResultsAmong the 39 patients, USG, parathyroid scintigraphy, and MRI correctly identified 35 adenomas (89.7%), 28 adenomas (71.8%), and 26 adenomas (66.7%), respectively. Positive predictive values for USG (34/35), scintigraphy (27/28), and cervical MR (26/26) imaging were 97.1%, 96%, and 100%, respectively. Parathyroid adenomas were detected with 92.3% (36/39) certainty when both USG and scintigraphy modalities were applied together. Minimally invasive parathyroidectomy under local anesthesia with unilateral incision was successfully performed in 24 (61.5%) patients.ConclusionsMinimally invasive surgery for parathyroid adenomas has been developed and has equal success with traditional surgery. However, accurate localization of adenomas should be obtained prior to surgery. In this study, ultrasound was found to be effective in localizing adenomas for successful surgery. Adding other imaging modalities does not improve localizing the parathyroid adenomas.  相似文献   
110.
Pigmented villonodular synovitis (PVNS) is a benign tumor that affects synovial lined joints, tendon sheaths and bursae. It is most commonly seen in one knee joint. The recommended treatment is total synovectomy, while radiotherapy can be used as adjuvant therapy for patients at risk for recurrence. The aim of our study was to show that the devastating effects of inactive diffuse PVNS may not be recognized for years and to evaluate the efficiency of aggressive total synovectomy on patients with PVNS during a follow-up period of 5 years. In the present study, 5 knees of four patients who had been previously followed due to gonarthrosis and diagnosed with PVNS during total knee arthroplasty (TKA) were followed and evaluated for a mean duration of 68 months. Mean age of the patients was 61.2 (52–66). All patients were women. One patient had right knee involvement, two had left knee involvement, and one had both knees involved. All patients had diffuse PVNS. Total synovectomy was performed in all patients in addition to TKA. During the follow-up, recurrence was not seen in any of the patients and prosthesis loosening was not detected. The aim of the present study was to evaluate the effectiveness of total synovectomy over the 5 years following the operation and to show that the devastating effects of inactive PVNS may sometimes be overlooked for years before being recognized during the treatment of the gonarthrosis that develops due to the disease. Although the disease is generally monoarticular, the study also presents a patient with bilateral PVNS.  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-23

京公网安备 11010802026262号