全文获取类型
收费全文 | 15273篇 |
免费 | 856篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 134篇 |
儿科学 | 561篇 |
妇产科学 | 241篇 |
基础医学 | 1711篇 |
口腔科学 | 477篇 |
临床医学 | 1100篇 |
内科学 | 3233篇 |
皮肤病学 | 294篇 |
神经病学 | 861篇 |
特种医学 | 508篇 |
外科学 | 1996篇 |
综合类 | 243篇 |
一般理论 | 9篇 |
预防医学 | 813篇 |
眼科学 | 683篇 |
药学 | 1575篇 |
1篇 | |
中国医学 | 123篇 |
肿瘤学 | 1624篇 |
出版年
2023年 | 82篇 |
2022年 | 228篇 |
2021年 | 425篇 |
2020年 | 223篇 |
2019年 | 300篇 |
2018年 | 394篇 |
2017年 | 248篇 |
2016年 | 317篇 |
2015年 | 417篇 |
2014年 | 527篇 |
2013年 | 700篇 |
2012年 | 1068篇 |
2011年 | 1081篇 |
2010年 | 553篇 |
2009年 | 554篇 |
2008年 | 791篇 |
2007年 | 812篇 |
2006年 | 816篇 |
2005年 | 763篇 |
2004年 | 697篇 |
2003年 | 631篇 |
2002年 | 553篇 |
2001年 | 342篇 |
2000年 | 362篇 |
1999年 | 273篇 |
1998年 | 143篇 |
1997年 | 88篇 |
1996年 | 97篇 |
1995年 | 103篇 |
1994年 | 71篇 |
1993年 | 77篇 |
1992年 | 186篇 |
1991年 | 191篇 |
1990年 | 171篇 |
1989年 | 151篇 |
1988年 | 145篇 |
1987年 | 171篇 |
1986年 | 143篇 |
1985年 | 121篇 |
1984年 | 127篇 |
1983年 | 89篇 |
1982年 | 60篇 |
1980年 | 59篇 |
1979年 | 72篇 |
1977年 | 58篇 |
1976年 | 63篇 |
1975年 | 59篇 |
1974年 | 83篇 |
1973年 | 68篇 |
1972年 | 58篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
We describ a case iaryngcul melanosis in a 62 year old male. the pigmentation was visible on gross examination during laryngoscopy ana histologicatly a single foci showing changes of carcinoma in situ was identified. The biopsy tissue, however did not reveal any frank changes of malignancy. 相似文献
82.
Ranjit Rajan Sridhar Reddy Rajamma Rajan 《Indian journal of otolaryngology and head and neck surgery》1997,49(4):368-373
The pectoralis major myocutaneous flap (PMMC flap) represents a landmark in the development of head and neck reconstructive
surgery. After Stephan Ariyan first described its use for head and neck reconstruction in 1979, it has become tremendously
popular and has revolutionised head and neck cancer surgery. Here, we present our initial experience with fourteen PMMC flaps
in head and neck reconstruction. In most of the instances it was used for oral or oropharyngeal reconstruction. It was used
for five other reconstructive tasks as well. Wound infection was the most common complication. There was no case of total
flap loss. It has proven to be a reliable method of reconstuction in the head and neck. 相似文献
83.
M. S. Vidyasagar Suresh Rao Donald J. Fernandes Ramanujam A. S. 《Indian journal of otolaryngology and head and neck surgery》1998,50(1):69-72
Primary Ewing’s sarcoma of the nasal bone has not been previously described. This case presented as a mass in the left ala
of the nose in a five year old female child. The clinical, radiological, microscopic features are described and a review of
literature is presented. The case was treated with neoadjuvant chemotherapy and local electron beam radiation therapy. The
child was free of disease when she reported for follow up in July 1997. Although wide excision is part of the treatment approach
in Ewing’s sarcoma, in sites where surgery is not suitable local radiotherapy and chemotherapy adequately controls primary
disease. 相似文献
84.
85.
Jaimanti Naresh K. Panda Suresh Sharma Ashok K. Gupta S. B. S. Mann 《Indian journal of otolaryngology and head and neck surgery》2004,56(2):99-104
Conclusion Patients with stage I and II tumors had the best results with radical radiotherapy alone 5 years survival for patients with
stage I and stage II tumors was 90-95% and 75-85% respectively Patients with advanced stage III & IV disease were treated
Unoperable stage IV cancer patients had poor outcome and received only palliative treatment 相似文献
86.
Breakthrough pain is a well recognized but ill-defined phenomenon that occurs commonly in the presence of otherwise stable, persistent pain. It is defined now as a "transient pain episode that occurs, or breaks through from the otherwise stable background pain." Breakthrough pain is usually associated with moderate to severe pain and may form a predictor of poor response to treatment with routine pharmacotherapy. Breakthrough pain is also associated with functional impairment and psychological distress. The assessment and treatment should be multidimensional. Although primary therapies such as chemotherapy, radiation treatment, and surgical options are explored, the mainstay of treatment is pharmacotherapy. Nonpharmacologic methods, such as orthotic devices and joint stabilizations along with behavioral methods, should be explored. Anesthetic and neurosurgical procedures are performed on a limited number of patients based on the prognosis, intractable nature of pain, and favorable risk/benefit ratio. Newer oral transmucosal fentanyl offers a favorable pharmacokinetic and pharmacodynamic profile and ease of administration. 相似文献
87.
Previous studies in schizophrenia have shown alterations in membrane phospholipids and polyunsaturated fatty acids. However, these studies have primarily examined peripheral (non-neuronal) cell types. The purpose of the present study was to examine whether the membrane deficits seen in peripheral tissues are also observed in the brain. The caudate was the primary region of interest for this study. Using high-pressure liquid chromatography in conjunction with an evaporative light-scattering detector, we first measured the level of various membrane phospholipids (PL) in schizophrenic (n=11) and control groups with (n=7) and without (n=14) other mental disorders. Polyunsaturated fatty acids (PUFAs) were then determined by capillary gas chromatography. Within groups, there are no significant correlations between membrane PL levels and other collection and demographic parameters including age, postmortem interval, storage time and brain weight. Significantly lower amounts of phosphatidylcholine and phosphatidylethanolamine were found in postmortem brain tissue from schizophrenic patients than in those from control groups, even after accounting for potential confounds. In addition, strong reductions of total PUFAs and saturated fatty acids were found in schizophrenic brains, relative to control brains. Specifically, the reduced PUFAs were largely attributable to decreases in arachidonic acid (AA) and, to a lesser extent, its precursors, linoleic and eicosadienoic acids. There are no significant differences between the control groups with and without other mental disorders. The present findings suggest that deficits identified in peripheral membranes may also be present in the brain from schizophrenic patients. Such a deficit in membrane AA may contribute to the many biological, physiological, and clinical phenomena observed in schizophrenia. 相似文献
88.
McElhinney DB Reddy VM Tworetzky W Petrossian E Hanley FL Moore P 《The Annals of thoracic surgery》2000,69(4):1222-1228
BACKGROUND: Systemic to pulmonary arterial collaterals often develop after bidirectional cavopulmonary anastomosis (BCPA). It has been proposed that such collaterals may be related to perioperative outcome and duration of effusions after the modified Fontan procedure. However, the incidence and significance of collaterals after BCPA remain uncertain. METHODS: To evaluate risk factors for, and significance of, such collaterals, we reviewed angiographic and clinical data for all 76 patients who underwent BCPA between January 1990 and June 1996 and had follow-up catheterization during or before 1997. RESULTS: The median age at BCPA was 10 months, and the median duration from BCPA to follow-up catheterization was 18 months. Arterial collaterals were detected on follow-up catheterization in 45 patients (59%). Factors associated with collateral development included a prior right-sided systemic-to-pulmonary arterial shunt, lower pre-BCPA end-diastolic ventricular pressure and pulmonary vascular resistance, and use and duration of cardiopulmonary bypass during the BCPA operation. Fourteen of the 45 patients (30%) underwent coil embolization of the collaterals. Forty-three patients have undergone extracardiac conduit Fontan, with 1 early and 1 late death. Collaterals were present in 22 of these patients, 7 of whom underwent pre-Fontan embolization. The duration from BCPA to Fontan was longer in patients with collaterals, but these patients were not more likely to have prolonged effusions than those without, and the duration of tube thoracostomy was significantly shorter in patients with collaterals. Embolization of collaterals did not affect the duration of effusions. CONCLUSIONS: Systemic-to-pulmonary arterial collaterals are common after BCPA. In contrast to prior reports, collaterals were not associated with a higher incidence of prolonged effusions after the Fontan procedure in our experience, and did not correlate with poor outcome. 相似文献
89.
Randomized phase II trial of three schedules of pemetrexed and gemcitabine as front-line therapy for advanced non-small-cell lung cancer. 总被引:1,自引:0,他引:1
Cynthia X Ma Suresh Nair Sachdev Thomas Sumithra J Mandrekar Daniel A Nikcevich Kendrith M Rowland Tom R Fitch Harold E Windschitl Shauna L Hillman Steven E Schild James R Jett Coleman Obasaju Alex A Adjei 《Journal of clinical oncology》2005,23(25):5929-5937
PURPOSE: A randomized three-arm phase II study was undertaken to evaluate the optimum administration schedule of pemetrexed and gemcitabine in chemotherapy-na?ve patients with non-small-cell lung cancer. PATIENTS AND METHODS: Patients were randomly assigned to three schedules of pemetrexed 500 mg/m2 plus gemcitabine 1,250 mg/m2, separated by a 90-minute interval, on a 21-day cycle as follows: schedule A, pemetrexed followed by gemcitabine on day 1 and gemcitabine on day 8; schedule B, gemcitabine followed by pemetrexed on day 1 and gemcitabine on day 8; and schedule C, gemcitabine on day 1 and pemetrexed followed by gemcitabine on day 8. RESULTS: One hundred fifty-two eligible patients (schedule A, n = 59; schedule B, n = 31, and schedule C, n = 62) received a median of five (schedule A), two (schedule B), and four (schedule C) treatment cycles. Overall, 66% of patients experienced grade 3 or 4 neutropenia. Common grade 3 and 4 nonhematologic toxicities were dyspnea (11%), fatigue (16%), and transaminase elevation (9%). Schedule A seemed less toxic compared with schedule C (grade 3 or 4 events: 86% v 94%, respectively; P = .19; grade 4 events: 39% v 48%, respectively; P = .30). Schedule B was closed at interim analysis for inferior efficacy. Schedule A, with a confirmed response rate of 31% (95% CI, 20% to 45%), met the protocol-defined efficacy criteria, whereas schedule C, with a confirmed response rate of 16.1% (95% CI, 11% to 34%), did not. Median survival time and time to progression were 11.4 and 4.4 months, respectively, with no observable difference between the arms. CONCLUSION: Pemetrexed and gemcitabine administered as outlined for schedule A met the protocol-defined efficacy criteria, was less toxic compared with the other treatment schedules, and should be further evaluated. 相似文献
90.
Janardhan J. Rao Vinaya EC. Kumar Sathavahana V. Chowdary Ram K. Babu Praveen Reddy Jitender Reddy 《Indian journal of otolaryngology and head and neck surgery》2005,57(1):30-34
Determination of obstructive site in obstructive sleep apnoea (OSA) is of paramount importance is planning the management. Cephalometric evaluation of lateral X-rays when combined with clinical assessment and fibreoptic examination of the airway helps in locating the site of obstruction. The usual technique of cephalometry has been modified so as to give a better delineation of the soft tissues. Holding a 2mm card board in the mouth and using barium paste helped in more accurate calculations. Using our technique, various parameters have been quantified and a number of controls were studied and normal range derived. Further improvement in cephalometry has been done by using C.T. cephlometry topogram technique. A topogram is a scan done on a running table top cranio-caudally. Using the topogram technique 38 OSA patients were evaluated for all the parameters. The technique, its advantages over traditional cephalometry and the values obtained in the study are discussed in this paper. 相似文献