全文获取类型
收费全文 | 10275篇 |
免费 | 630篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 96篇 |
儿科学 | 372篇 |
妇产科学 | 158篇 |
基础医学 | 1139篇 |
口腔科学 | 344篇 |
临床医学 | 699篇 |
内科学 | 2388篇 |
皮肤病学 | 226篇 |
神经病学 | 501篇 |
特种医学 | 376篇 |
外科学 | 1365篇 |
综合类 | 192篇 |
一般理论 | 5篇 |
预防医学 | 590篇 |
眼科学 | 494篇 |
药学 | 975篇 |
中国医学 | 51篇 |
肿瘤学 | 982篇 |
出版年
2023年 | 55篇 |
2022年 | 130篇 |
2021年 | 253篇 |
2020年 | 137篇 |
2019年 | 187篇 |
2018年 | 250篇 |
2017年 | 161篇 |
2016年 | 192篇 |
2015年 | 251篇 |
2014年 | 329篇 |
2013年 | 418篇 |
2012年 | 615篇 |
2011年 | 656篇 |
2010年 | 322篇 |
2009年 | 335篇 |
2008年 | 466篇 |
2007年 | 488篇 |
2006年 | 498篇 |
2005年 | 449篇 |
2004年 | 418篇 |
2003年 | 390篇 |
2002年 | 357篇 |
2001年 | 295篇 |
2000年 | 309篇 |
1999年 | 227篇 |
1998年 | 110篇 |
1997年 | 80篇 |
1996年 | 77篇 |
1995年 | 80篇 |
1994年 | 53篇 |
1993年 | 62篇 |
1992年 | 161篇 |
1991年 | 165篇 |
1990年 | 161篇 |
1989年 | 144篇 |
1988年 | 148篇 |
1987年 | 175篇 |
1986年 | 144篇 |
1985年 | 114篇 |
1984年 | 114篇 |
1983年 | 82篇 |
1982年 | 54篇 |
1979年 | 67篇 |
1977年 | 59篇 |
1976年 | 60篇 |
1975年 | 57篇 |
1974年 | 81篇 |
1973年 | 65篇 |
1972年 | 55篇 |
1971年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
C Sekar S Rajasekaran Rajesh Kannan Shashidhar Reddy T Ajoy Prasad Shetty Yogesh K Pithwa 《The spine journal》2004,4(3):261-264
BACKGROUND CONTEXT: Administration of analgesic medication, before the actual onset of painful stimulus, is more effective than that after the onset of painful stimulus. This is the principle of preemptive analgesia. Although it is often considered superior to other forms of analgesia, its role in postoperative pain relief after lumbosacral spinal surgery has not been fully investigated. PURPOSE: To analyze the efficacy of preemptive analgesia with a single caudal epidural injection for patients undergoing surgeries on the lumbosacral spine by the posterior approach. STUDY DESIGN/SETTING: Randomized, double-blinded and controlled clinical trial. PATIENT SAMPLE: Eighty-two patients who underwent discectomy in the lumbosacral spine by the posterior approach, with or without instrumentation, were randomized to the control group (n=40) and to the study group (n=42). METHODS: Patients in control group received a single caudal epidural injection of 20 ml of normal saline. Patients in study group received a single caudal epidural injection of 20 ml containing bupivacaine and tramadol as the active agents. The time interval between this injection and the surgical incision was never less than 20 minutes in either of the groups. This facilitated enough time for the drug to get fixed to the nerve roots, leading to effective preemptive analgesia. OUTCOME MEASURES: Patients were monitored for postoperative pain immediately after surgery when they had completely recovered and regained consciousness from general anesthesia, and subsequently 4, 8, 12 and 24 hours thereafter. Pain was quantified using the visual analog scale (VAS) and the verbal rating scale (VRS). The time at which supplemental analgesic medication was first demanded in the postoperative period by the patient was also noted. RESULTS: The two groups were comparable for age, sex, body weight and the type of surgery they underwent. Because the data did not have a normal Gaussian distribution, the one-tailed Mann-Whitney test, being a nonparametric test, was adopted for statistical analysis. Accordingly, VAS and VRS values at all time intervals were significantly lower (p<.0001) in the study group as compared with the control group. This indicated significantly better pain relief in the study group. There was also a significant delay (p=.0041) in the first demand for supplemental analgesic medication in the postoperative period in the study group. No complication specific to the procedure was noted except for the development of postoperative urinary retention, which was transient and appropriately managed with urinary catheterization. CONCLUSIONS: Preemptive analgesia with a single caudal epidural injection of bupivacaine and tramadol is a safe, simple and effective method for postoperative pain relief. 相似文献
33.
Ambakumar Nandakumar Narayanappa Anantha Thalagavadi Venugopal Sreerama Reddy Bapsy Padmanabhan Kumara Swamy Dinesh Doval Clementina Ramarao 《International journal of cancer. Journal international du cancer》1995,63(1):37-42
Lymphoid and haemopoietic malignancies as a group constitute one of the important cancers in India, as elsewhere in the world. While information on incidence and mortality of these cancers, and that on survival, are available from most developed countries, there are very few reports describing this experience in developing ones. Population-based cancer registration commenced in Bangalore, India, in January 1982, under the auspices of the Indian Council of Medical Research. This source provides fairly complete and reliable incidence data, but, in order to obtain mortality and survival information, active follow-up involving visits of homes of patients was undertaken. Between 1982 and 1989, 1397 cases of lymphoid and haemopoietic malignancies were registered in the Bangalore cancer registry, giving an age-adjusted incidence rate of 7.7 and 4.8 per 100,000 in males and females respectively. Active follow-up provided mortality/survival information in 1267 or 90.7% of these cases. The overall observed 5-year survival for these cancers combined (both sexes) was 26%, and relative survival 28.4%. The 5-year survival rate was lower in all the individual lymphomas and leukaemias as compared with similar reports from the developed countries. Survival in Hodgkin's disease was influenced by clinical stage and age at presentation. 相似文献
34.
The localization of Na,K-ATPase in the lens is quite controversial. We explored this problem through immunoelectron microscopic examination of rat and human lens. Unlike previously reported results, we have found that Na,K-ATPase is localized in the basal plasma membrane, but not in the lateral or apical plasma membrane of both rat and human lens epithelium. The lens fiber lacked immunoreaction. Localization of Na,K-ATPase was also investigated in the cultured human lens epithelium and in lentoid. Immunoreaction was detected in the apical (facing the media) plasma membrane of the lens epithelium cultured on the lens capsule, whereas the reaction was observable in both apical and basal plasma membrane of the lens epithelium cultured on the biopore membrane filters. Immunoreaction in lentoid was observed in the surface plasma membrane. These data indicate that the polarized distribution seen in the in situ lens epithelium changes when these cells are cultured, and that Na,K-ATPase in the cultured lens cells including lentoid is located in the plasma membrane which is in contact with the growth media. This change in polarity of Na,K-ATPase distribution in cultured epithelial cells may be dictated by the need to maintain ion homeostasis by extrusion of sodium ions across the cell membrane facing the media. 相似文献
35.
36.
37.
38.
R. Srinivas Reddy S. Bajaj A. R. Tolat J. Compson 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2007,17(4):373-376
Neurofibromas in the hand are uncommon and constitute less than 5% of all hand tumours. Accurate diagnosis and appropriate management are important because malignant transformation has been reported, especially in Von Recklinghausen’s neurofibromatosis. We report a case of a large neurofibroma in the right hand of an 18-year-old girl of Afro-Caribbean origin. She was symptomatic with complaints of pain and weakness of grip. General examination revealed multiple café-au-lait spots on the trunk and one nodular swelling in the forearm. The swelling was excised through a palmar approach and histology proved it to be a neurofibroma. The case is being reported for its rarity and it emphasizes the importance of general examination. Histopathological examination is vital in excluding malignant transformation. 相似文献
39.
Walter R T Witschey Arijitt Borthakur Mark A Elliott Eric Mellon Sampreet Niyogi Chenyang Wang Ravinder Reddy 《Magnetic resonance in medicine》2007,57(1):2-7
The origin of image artifacts in an off-resonance spin-locking experiment is shown to be imperfections in the excitation flip angle. A pulse sequence for off-resonance spin locking is implemented that compensates for imperfections in the excitation flip angle through an off-resonance rotary echo. The off-resonance rotary echo alternates the frequency offset and phase of the RF transmitter during two spin-locking pulses of equal duration. The underlying theory is detailed, and MR images demonstrate the effectiveness of the technique in agarose gel phantoms and in in vivo human brain at 3T. 相似文献
40.
Hector Rodriguez-Luna Hugo E. Vargas Adyr Moss Kunam S. Reddy Richard B. Freeman David Mulligan 《American journal of transplantation》2005,5(9):2244-2247
The Model for End-Stage Liver Disease (MELD) is used to assign priority for liver transplantation candidates. The Organ Procurement and Transplantation Network (OPTN) approved recognized exceptional diagnoses (RED's) for which MELD fails to accurately measure priority. Centers can request increased MELD points in cases not recognized by this policy (non-RED's). Our aim was to compare regional practices to justify non-RED requests for MELD adjustments. The UNOS/OPTN database was queried to extract all adult cases for which a non-RED MELD adjustment was requested from 2/27/02 until 8/27/03. The data were stratified by region and justification. Data for 29,510 listings were available. 26,947 had complete diagnosis information. There were 827 non-RED requests of which 477 (57.7%) petitions were approved by the regional review boards (RRBs). The approval rate varied significantly among regions (range: 28-75%, p<0.0001). The most common non-RED's were complications of portal hypertension (48%). The percentage of patients listed with non-RED's varied significantly among regions (0.7-8.3 %, p<0.0001), as did the proportion of patients transplanted with non-RED's (2.1-31.9%, p<0.0001). Demographics did not differ among regions requesting non-REDs.Widespread regional variations exist in the handling of requests for non-REDs. These variations point to the need for reform to standard exception criteria. 相似文献