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   414篇
  免费   18篇
  国内免费   4篇
耳鼻咽喉   5篇
儿科学   10篇
妇产科学   12篇
基础医学   40篇
口腔科学   9篇
临床医学   39篇
内科学   128篇
皮肤病学   1篇
神经病学   22篇
特种医学   15篇
外科学   90篇
预防医学   30篇
眼科学   4篇
药学   9篇
肿瘤学   22篇
  2023年   3篇
  2022年   6篇
  2021年   21篇
  2020年   8篇
  2019年   12篇
  2018年   11篇
  2017年   13篇
  2016年   7篇
  2015年   6篇
  2014年   11篇
  2013年   22篇
  2012年   32篇
  2011年   17篇
  2010年   10篇
  2009年   8篇
  2008年   12篇
  2007年   24篇
  2006年   19篇
  2005年   19篇
  2004年   18篇
  2003年   16篇
  2002年   16篇
  2001年   10篇
  2000年   11篇
  1999年   14篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1994年   5篇
  1992年   3篇
  1991年   12篇
  1990年   17篇
  1989年   8篇
  1988年   8篇
  1987年   10篇
  1986年   3篇
  1985年   3篇
  1984年   1篇
  1979年   2篇
  1973年   5篇
  1970年   1篇
  1968年   3篇
  1967年   2篇
  1966年   2篇
  1965年   1篇
排序方式: 共有436条查询结果,搜索用时 15 毫秒
81.
82.
83.
Pure menstrual migraine (PMM) and menstrually related migraine (MRM) are difficult challenges in migraine management. Triptans are a class of highly selective serotonin receptor agonists, which interfere with the pathogenesis of migraine and are effective in relieving the associated neurovegetative symptoms. In recent years triptans have been extensively proposed for the treatment of severe, disabling, and recurrent perimenstrual migraine attacks. This review summarizes the different levels of recommendations for the use of triptans in the treatment of perimenstrual migraine. This review is also intended to offer an updated reasonable guide to physicians treating perimenstrual migraine in daily practice.  相似文献   
84.
BACKGROUND: Cholecystoenteric fistula (CF) is a rare complication of cholelithiasis. The aim of this study was to evaluate the safety and risk of complications when the laparoscopic approach is applied in patients with CF. METHODS: A questionnaire was mailed to all surgeons with experience of >100 cholecystectomies working in Naples, Italy, and the neighboring area. RESULTS: Between February 1990 and May 1999, 34 patients presented with cholecystoenteric fistula (0.2% of >15,000 laparoscopic cholecystectomies performed in the same period). These patients were allocated into two groups: the LT group (those who underwent laparotomic conversion after the diagnosis of CF), which consisted of 20 patients, four men and 16 women, with a mean age of 66.5 +/- 9.3 years (range, 46-85) and the LS group (laparoscopically treated patients), which consisted of 14 patients, three men and 11 women, with a mean age of 65.6 +/- 8.8 years (range, 51-74). They types of CF observed were as follows: in the former group of patients, cholecystoduodenal fistulas (n = 11, 55%), cholecystocolic fistulas (n = 5, 25%), cholecystojejunal fistulas (n = 3, 15%), and cholecystogastric fistulas (n = 1, 5%); in the latter group, cholecystoduodenal fistulas (n = 8, 5.1%), and cholecystocolic fistulas (n = 4, 28.6) and cholecystojejunal fistulas (n = 2, 14.3%). Stapler closure of CF was done in four LT patients and three LS patients with cholecystoduodenal fistula; it was also done in three LT patients and three LS patients with cholecystocolic fistula. Hand-sutured fistulectomy was performed in six LT patients and three LS patients with cholecystoduodenal fistula, in two LT patients with cholecystocolic fistula, and in all patients with cholecystojejunal or cholecystogastric fistula. There were no deaths or intraoperative complications in either group. One patient in the LT group developed a bronchopneumonia postoperatively. Postoperative hospital stay was significantly longer in LT patients-17 +/- 4 vs 3+/-1 days (p < 0.001). CONCLUSION: Cholecystoenteric fistula is an occasional intraoperative finding during laparoscopic cholecystectomy. The results of this study, which are based on the collective experiences of 19 surgeons, illustrate the growing success of the laparoscopic approach to this condition, including a decreasing rate of conversion to open surgery over the last 3 years.  相似文献   
85.
PURPOSE: To assess the outcome of Magnetic Resonance Imaging (MRI) in the diagnosis of sportsman hindfoot pain. MATERIALS AND METHODS: Fortythree professional athletes (31 men, 12 women, age range: 17-37 years) affected by hindfoot pain underwent MRI. Spin echo (SE) T1W, Gradient echo (GE) T2*W, and fat suppression (Short Time Inversion Recovery: STIR) images were acquired with a 0.5 T superconductive unit (Vectra, GE Medical System, Milwaukee, WI, USA). A dedicated extremities transmitter/receiver coil was used. The lesion site, the presence of anatomic variants (os trigonum, Haglund's deformity), and signal intensity changes were evaluated. RESULTS: In all cases MRI allowed the identification of the cause of the hindfoot pain, in relation to soft tissue (bursae, synovial or nervous structures), bone and articular diseases. Particularly, as regards soft tissue diseases, tendinous abnormalities and inflammatory bursal involvement were frequently found (77% of cases). Bone diseases (22% of cases with posterior talalgia alone), mostly involved the heel (60%), whereas cartilagineous diseases were present in 9% of cases. In 60% of cases an intra-articular osseous or cartilagineous displaced fragment coexisted, determinating joint locking during foot flexo-extension movements. In 38% of cases contemporary involvement of different articular structures was observed. DISCUSSION: Both MRI high contrast resolution and multiplanar capabilities allow the complete evaluation of hindfoot region. In our experience sagittal and axial planes were particularly well suited for the diagnosis and the assessment of disease extension. Furthermore, T2W (GET2*) and fat suppression (STIR) images allow high sensitivity even in early disease detection, when hyperemia or fluid collection occur. CONCLUSIONS: According to our results, it seems possible to state that nowadays MRI is the most reliable technique for identifying the causes of hindfoot pain, in order to provide a correct and effective pre-therapeutic planning.  相似文献   
86.
The expression of aromatase, estrogen receptor alpha (ERalpha) and beta (ERbeta), androgen receptor (AR), and cytochrome P-450 side chain cleavage enzyme (cP450scc) was studied in prepubertal testis. Samples were divided in three age groups (GRs): GR1, newborns (1- to 21-d-old neonates, n = 5); GR2, postnatal activation stage (1- to 7-mo-old infants, n = 6); GR3, childhood (12- to 60-mo-old boys, n = 4). Absent or very poor detection of ERalpha by immunohistochemistry in all cells and by mRNA expression was observed. Leydig cells (LCs) of GR1 and GR2 showed strong immunostaining of aromatase and cP450scc but weak staining of ERbeta and AR. Interstitial cells (ICs) and Sertoli cells (SCs) expressed ERbeta, particularly in GR1 and GR2. Strong expression of AR was found in peritubular cells (PCs). For all markers, expression in GR3 was the weakest. In germ cells (GCs), i.e. gonocytes and spermatogonia, aromatase and ERbeta were immunoexpressed strongly whereas no expression of ERalpha, AR, or cP450scc was detected. It is proposed that in newborn and infantile testis, testosterone acting on PCs might modulate infant LC differentiation, whereas the absence of AR in SCs prevents development of spermatogenesis. The role of estrogen is less clear, but it could modulate the preservation of an adequate pool of precursor LCs and GCs.  相似文献   
87.
88.
[11C]metomidate ([11C]MTO) is a radiotracer widely used to detect disorders of adrenocortical origin by positron emission tomography (PET) imaging. [11C]MTO PET/computed tomography (PET/CT) is considered a sensitive and specific noninvasive alternative to adrenal vein sampling (AVS) in the management of primary hyperaldosteronism (PHA). Herein, we report a reliable automated procedure for the routine manufacturing of [11C]MTO in current good manufacturing practice (cGMP) conditions on the commercial Synthra MeIPlus Loop Vessel synthesizer. The method is based on a combination of the captive‐solvent 11C‐methylation of the carboxylate salt 1b of the MTO precursor 1a followed by solid phase extraction (SPE) cartridge purification methodology, which substitutes HPLC purification of the crude reaction mixture. Starting from 45 GBq [11C]CO2 at the end of bombardment (EOB), 3 GBq of pure [11C]MTO was produced in 18 minutes with 12% decay corrected radiochemical yield (RCY) at the end of synthesis (EOS) and with the modest molar activity of 13 GBq/μmol at the time of application. Each dose produced met all established quality control (QC) criteria. The method can easily be implemented into other commercial automated radiosynthesizers for manufacturing carbon‐11 labeled radiotracers.  相似文献   
89.
90.
Hyperchloremic metabolic acidosis of renal origin results from a defect in renal tubular acidification mechanism, and this tubular dysfunction can consist of an altered tubular proton secretion or bicarbonate reabsorption capability. Studies have documented that all forms of renal tubular acidosis (RTA), type I to IV, are documented in kidney transplant patients. Among RTA pathophysiologic mechanisms have been described the renal mass reduction, hyperkalemia, hyperparathyroidism, graft rejection, immunologic diseases, and some drugs such as renin-angiotensin-aldosterone blockers, and calcineurin inhibitors. RTA can lead to serious complications as is the case of muscle protein catabolism, muscle protein synthesis inhibition, renal osteodystrophy, renal damage progression, and anemia promotion. RTA should be treated by suppressing its etiologic factor (if it is possible), avoiding hyperkalemia, and/or supplying bicarbonate or a precursor (citrate). In conclusion: Hyperchloremic metabolic acidosis of renal origin is a relatively frequent complication in kidney transplantation patients, which can be harmful, and should be adequately treated in order to avoid its renal and systemic adverse effects.  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