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   718篇
  免费   44篇
  国内免费   2篇
耳鼻咽喉   12篇
儿科学   22篇
妇产科学   21篇
基础医学   64篇
口腔科学   11篇
临床医学   53篇
内科学   152篇
皮肤病学   7篇
神经病学   41篇
特种医学   12篇
外科学   186篇
综合类   19篇
现状与发展   1篇
一般理论   1篇
预防医学   47篇
眼科学   39篇
药学   40篇
中国医学   2篇
肿瘤学   34篇
  2023年   4篇
  2022年   7篇
  2021年   29篇
  2020年   7篇
  2019年   15篇
  2018年   28篇
  2017年   21篇
  2016年   12篇
  2015年   20篇
  2014年   22篇
  2013年   33篇
  2012年   63篇
  2011年   46篇
  2010年   36篇
  2009年   19篇
  2008年   40篇
  2007年   44篇
  2006年   49篇
  2005年   37篇
  2004年   47篇
  2003年   35篇
  2002年   33篇
  2001年   11篇
  2000年   15篇
  1999年   10篇
  1998年   2篇
  1997年   5篇
  1996年   4篇
  1995年   4篇
  1994年   6篇
  1993年   3篇
  1992年   4篇
  1991年   7篇
  1990年   4篇
  1989年   8篇
  1987年   2篇
  1986年   4篇
  1985年   3篇
  1984年   4篇
  1982年   2篇
  1980年   2篇
  1979年   3篇
  1976年   1篇
  1973年   1篇
  1972年   2篇
  1971年   2篇
  1970年   1篇
  1968年   2篇
  1967年   1篇
  1966年   1篇
排序方式: 共有764条查询结果,搜索用时 15 毫秒
1.
Substance P and eledoisin stimulate the accumulation of inositol phosphates in a dose-dependent manner in retinal and superior colliculus slices of the rabbit. The EC50 values for substance P and eledoisin in both tissues were of the same order (1.5-4.9 microM), suggesting that the receptors in the two tissues were alike with characteristics of the SP-P subtype rather than the SP-E subtype. These data suggest that the SP-immunoreactive material in the retinal ganglion and amacrine cells is identical. The effectiveness for a number of tachykinin substances at 10(-5) M for stimulating inositol phosphates accumulation was as follows: Substance P greater than eledoisin greater than neurokinin A greater than neurokinin B greater than substance P (octapeptide) greater than substance P (pentapeptide). Spantide [(D-Arg1, D-Try7.9, Leu11) substance P] and (D-Pro2, D-Try7.9) substance P did not stimulate inositol phospholipid hydrolysis. However, spantide, at a concentration of 10(-6) M, was an antagonist of the effect produced by substance P, but had no action on the effect produced by neurokinin A or neurokinin B. Substance P and other tachykinins were also effective in stimulating inositol phosphates accumulation in 3-5-day-old rabbit retinal cultures but did not elicit a response in the older (25-30-day-old) cultures which lacked neurones but contained Müller cells. Furthermore, substance P was only active in the younger cultures in stimulating an increase in internal calcium levels. It is therefore concluded that retinal tachykinin receptors linked to phosphoinositide turnover and calcium mobilisation are associated exclusively with neurones and not with Müller cells.  相似文献   
2.
Trigger finger is uncommon among children and often caused by various lesions. We report a 5-year old girl who presented with chronic painless triggering of the right ring finger and normal X-ray. She underwent exploration of the finger flexor tendons and release of the A1 pulley. Lack of obvious pathology dictated further wound exploration which revealed a hidden osteochondroma of the proximal phalanx. We believe that adequate surgical wound exposure is necessary if no obvious cause of triggering could be seen in order to rule out an atypical osteochondroma even in the presence of normal X-rays.  相似文献   
3.
BACKGROUND: The hemagglutination inhibition (HI) assay is a frequently used method to screen human sera for antibodies against influenza A viruses. Because HI has relatively poor sensitivity in detecting antibodies against avian influenza A strains, a more complicated microneutralization (MN) assay is often preferred. Recent research suggests that the sensitivity of the HI assay can be improved by switching from the traditionally used turkey, guinea pig, human, or chicken RBCs to horse RBCs. OBJECTIVE: To evaluate the performance of the horse RBC HI when screening for human antibodies against avian influenza types H3, H4, H5, H6, H7, H9, H11, and H12. STUDY DESIGN: We evaluated the reproducibility of horse RBC HI and its agreement with MN results using sera from people exposed or not exposed to wild and domestic birds. RESULTS: The horse RBC HI assay had high reliability (90%-100%) and good agreement with MN assay results (52%-100%). CONCLUSION: The horse RBC HI assay is reliable, less expensive, less complex, and faster than the MN assay. While MN will likely remain the gold standard serologic assay for avian viruses, the horse RBC HI assay may be very useful as a screening assay in large-scale epidemiologic studies.  相似文献   
4.
Biliary tract obstruction in a 30-year-old man was found to be caused by a malignant melanoma in the common bile duct. Melanin pigment was demonstrated by immunohistochemistry and electron microscopy. Extensive search for a primary malignant melanoma elsewhere was unsuccessful. No pigmented lesions had been removed previously. There were junctional changes in the mucosa of the common bile duct close to the tumor. The malignant melanoma in the common bile duct therefore is considered to be primary. Only one other case of primary malignant melanoma in the common bile duct has been described in the literature, whereas metastases to the major bile ducts in one autopsy study of malignant melanoma in the more common locations were found with a frequency of 6 per cent.  相似文献   
5.
Lasers in Medical Science - Diabetes mellitus is mostly interrelated to deficiency in wound healing. Low-level laser therapy has been shown to exert reliable effects on the acceleration of wound...  相似文献   
6.
Background/Objective: Ischemia is a leading cause of morbidity in Mechanical Intestinal Obstruction (MIO) in which the timing of decisions of whether to proceed to surgical or conservative treatment is critical in emergency departments (ED). While advanced technological options are available, patients may be negatively affected by the application of contrast agents or radiation. The use of ultrasound is limited because of the air in the intestines does not allow a good field of vision. While biomarkers can be considered as a good alternative option at this point. In the present study we examine the effect of hemogram and blood gas parameters on early surgical decision-making in MIO patients.MethodInvolved in this observational prospective study were 264 patients diagnosed with MIO who presented to the Department of Emergency Medicine, Ataturk Research and Training Hospital, Katip Celebi University between February 2018 and February 2019. Contrast-enhanced tomography (CECT) and laboratory results of the patients were recorded. Pathology reports of the patients who underwent surgery were collected. Laboratory data were analyzed by comparing CECT and pathology reports.ResultsIn a ROC analysis of the laboratory values of the patients who were diagnosed with ileus, the sensitivity was calculated as 80% and the specificity was 57.7 in values above WBC>10.75 (109/L), 96.6%, and the specificity was 31.1% in N/L > 2.9. For intestinal ischemia, the cut-off values were WBC> 12.6 and N/L > 3.2, Lactate >2.8 mmol/L and B.E < -3.6 mmol/L.ConclusionDiagnoses of ileus are based on the results examinations and imaging methods. More data are needed to support decisions on the timing of surgery in ED. WBC, N/L, Lactate and Base Excess indicate an ischemic segment. When the parameters are evaluated together, they strongly support early surgical decision-making regarding the treatment of intestinal ischemia.  相似文献   
7.
8.
Background: There are several congenital hand differences that cause thumb-index (TI) web space deficiency. There is a knowledge gap in the literature about the hand differences that are associated with TI web space deficiency. We aimed to identify these congenital differences and the various specific reconstructive surgical procedures that are used for these conditions. Methods: We conducted a retrospective chart review of children treated operatively over a period of 30 years for congenital TI web space deficiency by the senior author (G.M.R.). We gathered data on demographics and associated congenital hand differences and compiled a list of all surgical procedures performed for the web space and the ipsilateral upper extremity. Results: We included 71 patients (77 hands) with 12 congenital hand differences (62 developmental and 9 spastic). The total number of upper extremity operations, (ie), anesthetics performed for these patients was 186, averaging 2.6 settings and 7.5 procedures for each patient. Cutaneous reconstructive procedures included first dorsal metacarpal artery pedicle flaps (49 patients), 4-flap Z-plasties (15), and transposition flaps (13). In addition, 16 different thumb reconstructive procedures were necessary. Ten patients required revision of their TI web space procedures for recurrence. Conclusions: The prevalence of TI web space deficiency is underappreciated. These patients often have multiple musculoskeletal anomalies of the hand and upper extremity that should be ruled out and require surgical treatment to optimize hand function. Consideration should be given to performing more than one procedure in one setting when possible.  相似文献   
9.
Murphy CA  Ghazi L  Kokabi A  Ellison G 《Brain research》1999,851(1-2):175-182
The lateral habenula is a nucleus in the dorsal thalamus that innervates midbrain dopaminergic and serotonergic nuclei via projections through its major efferent pathway, the fasciculus retroflexus (FR). It was previously demonstrated that cocaine administered continuously to adult rats over several days produces neurodegeneration in the lateral habenula and FR. Because exposure to cocaine during pregnancy reportedly can cause neurobehavioral deficits, we examined whether rat fetuses exposed to continuous cocaine during the last week of gestation would similarly demonstrate selective neurodegeneration in the lateral habenula. On day 17 of gestation, dams were implanted with two silicone pellets, each containing either vehicle or one of 2 doses of cocaine (80 mg or 55 mg per pellet). Degenerating neurons containing silver deposits were counted in lateral habenula and in the striatum. Cocaine-exposed pups had significantly more silver-stained cells in the lateral habenula than vehicle-treated pups, but similar numbers of silver-stained cells were present in the striatum of all three groups. When similarly treated vehicle- and cocaine-exposed animals were tested behaviorally at 60 days of age, they did not differ on measures of open field activity, open arm avoidance on the elevated plus-maze or conditioned place preference for cocaine, although a linear trend analysis indicated some hyperactivity of the cocaine-pretreated pups during the place preference test. These results indicate that continuous cocaine exposure has selective neurotoxic effects on the habenula of the developing fetus similar to cocaine's effects in the adult.  相似文献   
10.
Disseminated strongyloidiasis is a disease with high mortality rate, especially in immunocompromised individuals. Paralytic ileus and intestinal malabsorption are frequent symptoms caused by this severe disease. As there are no licensed parenteral anthelmintic drugs for human use, off-label formulations are often used in the treatment of this disease. In this case report, the use of subcutaneous ivermectin is described as a successful therapy for this life-threatening infection.  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