全文获取类型
收费全文 | 218191篇 |
免费 | 8450篇 |
国内免费 | 445篇 |
专业分类
耳鼻咽喉 | 3086篇 |
儿科学 | 6296篇 |
妇产科学 | 5579篇 |
基础医学 | 31376篇 |
口腔科学 | 6943篇 |
临床医学 | 12759篇 |
内科学 | 48107篇 |
皮肤病学 | 5934篇 |
神经病学 | 17630篇 |
特种医学 | 5280篇 |
外国民族医学 | 2篇 |
外科学 | 25332篇 |
综合类 | 1010篇 |
一般理论 | 41篇 |
预防医学 | 25259篇 |
眼科学 | 5734篇 |
药学 | 17157篇 |
中国医学 | 821篇 |
肿瘤学 | 8740篇 |
出版年
2023年 | 1084篇 |
2021年 | 3153篇 |
2020年 | 1753篇 |
2019年 | 3652篇 |
2018年 | 6636篇 |
2017年 | 4137篇 |
2016年 | 4065篇 |
2015年 | 4575篇 |
2014年 | 4969篇 |
2013年 | 7789篇 |
2012年 | 13330篇 |
2011年 | 13884篇 |
2010年 | 6964篇 |
2009年 | 4981篇 |
2008年 | 11440篇 |
2007年 | 12303篇 |
2006年 | 11857篇 |
2005年 | 11504篇 |
2004年 | 10681篇 |
2003年 | 9983篇 |
2002年 | 9544篇 |
2001年 | 6776篇 |
2000年 | 7451篇 |
1999年 | 5773篇 |
1998年 | 972篇 |
1992年 | 3026篇 |
1991年 | 2753篇 |
1990年 | 2701篇 |
1989年 | 2340篇 |
1988年 | 2190篇 |
1987年 | 2085篇 |
1986年 | 2089篇 |
1985年 | 1945篇 |
1984年 | 1415篇 |
1983年 | 1195篇 |
1979年 | 1614篇 |
1978年 | 1036篇 |
1977年 | 963篇 |
1976年 | 931篇 |
1975年 | 1120篇 |
1974年 | 1515篇 |
1973年 | 1500篇 |
1972年 | 1394篇 |
1971年 | 1343篇 |
1970年 | 1325篇 |
1969年 | 1382篇 |
1968年 | 1397篇 |
1967年 | 1241篇 |
1966年 | 1089篇 |
1965年 | 704篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
61.
62.
A López Bernal D J Hansell S Alexander A C Turnbull 《British journal of obstetrics and gynaecology》1987,94(11):1052-1058
The production of progesterone from pregnenolone, of cortisol from cortisone and of prostaglandin E (PGE) under basal and arachidonic acid-stimulated conditions was measured in cells dispersed from chorion and decidua. The cells were obtained after delivery from four groups of women: following spontaneous labour at term (38-42 weeks gestation), at elective caesarean section at term before the onset of labour, after induced labour at term, and after uncomplicated preterm (27-36 weeks) labour. Chorionic cells had a high progesterone output with relatively low cortisol and PGE production, whereas decidual cells had a high cortisol and PGE production rate. Free arachidonic acid stimulated PGE production in both decidual and chorionic cells. There were no significant differences in either steroid or PGE production among the four groups studied. These data suggest that steroid dehydrogenase activity in choriodecidual cells is not related to the mode of onset of labour and that the increased prostaglandin production in intrauterine tissues associated with parturition is due to enhanced availability of arachidonic acid. 相似文献
63.
Raúl González-García Francisco J Rodríguez-Campo Verónica Escorial-Hernández Mario F Mu?oz-Guerra Jesús Sastre-Pérez Luis Naval-Gías José L Gil-Díez Usandizaga 《Journal of oral and maxillofacial surgery》2006,64(11):1587-1591
PURPOSE: Temporomandibular joint (TMJ) arthroscopy has been considered a safe surgical procedure in the treatment of TMJ derangement. However, it is not exempt from complications. This study evaluates the complications of arthroscopy in patients with internal derangement of TMJ. PATIENTS AND METHODS: Five hundred consecutive patients (670 joints) with TMJ derangement who underwent arthroscopy between 1995 and 2004 were retrospectively analyzed. All the patients were classified as II to V in the Wilkes classification. Lysis and lavage, electrocautery of the posterior ligament, injection of corticoids, injection of ethanolamine, myotomy of lateral pterygoid muscle attachments, myotomy and electrocautery, motor debridement, injection of sodium hyaluronate, and meniscal suture were performed in different patients. RESULTS: Complications were recognized during or immediately after the surgery. They were observed in 5 of 341 (1.26%) arthroscopies of the right TMJ and 4 of 329 (1.21%) arthroscopies of the left TMJ. A 1.34% complication rate was found in the whole series. No blood clots within the external auditory canal were observed. Bleeding within the superior TMJ space was observed in 57 cases (8.5%), 36 of them in the right TMJ and 21 in the left TMJ, but they were not considered as true complications. Lacerations of the external auditory canal were found in 2 cases (0.3%), with no cases of perforation of the tympanic membrane. Lesion of the auriculotemporal nerve was observed in a case. Paresia of the facial nerve was found in 4 cases (0.6%). Alteration of visual accuracy of the ipsilateral eye was also observed in a patient immediately after the surgery. CONCLUSION: Special care must be taken to reduce complications within the upper joint space by means of an adequate instrumentation and by paying attention to essential points of the arthroscopic technique. 相似文献
64.
Cari Borrás 《Pan American journal of public health》2006,20(2-3):173-187
This report summarizes and analyzes the responses of various organizations that provided assistance to the National Oncology Institute (Instituto Oncológico Nacional, ION) of Panama following the overexposure of 28 radiation therapy patients at the ION in late 2000 and early 2001. The report also looks at the long-term measures that were adopted at the ION in response to the overexposure incident, as well as implications that the incident has for other cancer treatment centers worldwide. In March 2001, the director of the ION was notified of serious overreactions in patients undergoing radiation therapy for cancer treatment. Of the 478 patients treated for pelvic cancers between August 2000 and March 2001, 3 of them had died, possibly from an overdose of radiation. In response, the Government of Panama invited international experts to carry out a full investigation of the situation. Medical physicists from the Pan American Health Organization (PAHO) were among those invited. They ascertained that 56 patients treated with partially blocked teletherapy fields for cancers of the uterine cervix, endometrium, prostate, or rectum, had had their treatment times calculated using a computerized treatment planning system. PAHO's medical physicists calculated the absorbed doses received by the patients and found that, of these 56 patients, only 11 had been treated with acceptable errors of +/-5%. The doses received by 28 of the 56 patients had errors ranging from +10 to +105%. These are the patients identified by ION physicists as overexposed. Twenty-three of the 28 overexposed patients had died by September 2005, with at least 18 of the deaths being from radiation effects, mostly rectal complications. The clinical, psychological, and legal consequences of the overexposures crippled cancer treatments in Panama and prompted PAHO to assess radiation oncology practices in the countries of Latin American and the Caribbean. ION clinicians evaluated the outcome of 125 non-overexposed patients who had been treated in the same time period and for the same cancer sites as the overexposed patients. The clinicians uncovered a larger recurrence of cervical cancers than expected. The finding prompted PAHO to launch an initiative for the accreditation of radiation oncology centers in Latin America and the Caribbean, working in collaboration with professional societies for radiation oncologists, medical physicists, and radiotherapy technologists. The Latin American Association for Radiation Oncology (Asociación Latinoamericana de Terapia Radiante Oncológica) has established an accreditation commission. Accreditation will require that centers implement a comprehensive radiation oncology quality assurance program that follows international guidelines. Statistical data on patient outcomes will be collected in order to document needs in radiotherapy centers in Latin America and the Caribbean and to define future strategies for cancer treatment. 相似文献
65.
Henyse G V Silva Rosangela P Tórtora Maria Lucia F Farias 《Gynecological endocrinology》2005,21(3):174-179
To evaluate the impact of pregnancy on bone, we studied bone turnover at the first (T1) and third (T3) trimester of gestation in 58 adolescents and 28 healthy adolescents who had never been pregnant. Total body (TB) and lumbar spine (LS) bone mineral density (BMD) and body composition were evaluated by dual-energy X-ray absorptiometry in all control patients (C) and after parturition in 28 pregnant patients (G). Paired and unpaired t tests, Mann-Whitney and Pearson correlation tests were used. Bone turnover markers were above the reference range for adult women in more than 80% of the adolescents, with no difference between C and G patients at T1. Increase in urinary N-telopeptide crosslinks of type I collagen and serum bone-specific alkaline phosphatase, markers of bone turnover, was seen during pregnancy ( p < 0.0001). Body composition did not differ between groups, but LS BMD, percentage of expected LS BMD, LS Z-score, percentage of expected TB BMD and TB Z-score were lower in G than C patients ( p < 0.05). TB BMD was positively correlated with LS BMD (r2 = 0.52). The inverse correlations between bone markers and LS BMD suggest that the increased bone turnover during pregnancy probably explains the low bone density after parturition. The impact on future peak bone mass must be studied. 相似文献
66.
This study presents the case of a patient with necrobiosis or necrosing fascitis of the inguinal region, secondary to a complicated
Amyand’s hernia with a concomitant ipsilateral Richter’s hernia. The patient was treated with open trans-abdominal surgery
and hernia repair through the pre-peritoneal approach, plus anti-microbians, and thrice-daily wound cleansing and dressings
to the inguinal region. Evolution was satisfactory. There are no reports in the literature of a case such as this. 相似文献
67.
68.
J Czigány 《Orvosi hetilap》1989,130(4):177-181
The tele-thermographic examinations are of non-invasive character, they can be repeated any time and may be applied also for check-up examinations. The fact that they are evaluated together with other completing clinical examinations (X-ray, scintigraphy, ultrasonography, biopsy etc.) gives the objective significance and value of the examination. According to the author's observation the tele-thermography provides important help in the diagnostics of cervico-facial tumors, in the demonstration of metastases before the operation and detection of postoperative recurrences, in the follow-up of the patient's condition at the period of irradiation- or cytostatic therapy gives exact information in dermatology on the biological activity and extent of malignant melanoma. The treatment of persons with burn- or frostbite injuries requires it equally and good information may be obtained by its use on the condition of blood circulation in cases of vascular obstruction and vascular anomalies. 相似文献
69.
70.
J Vargas-Barrón A Andrade-Freire J C Ramírez E Waisser J Martínez-Sánchez 《Archivos del Instituto de Cardiología de México》1989,59(2):121-124
The purpose of this study is to determine the importance of two-dimensional echocardiography performed soon after admission to the coronary care unit to provide useful information concerning wall-motion abnormalities, and to detect and characterize left ventricular thrombi. A major goal is to identify a subgroup of patients with acute myocardial infarction who are at risk for systemic embolization; in this subgroup the benefits of anticoagulation treatment would theoretically outweigh the associated risks. We studied 7 consecutive male patients, age range from 32 to 60 years, with acute myocardial infarction. Five patients had antero-septal infarction, 1 anterolateral and another had anterior wall infarction. We performed two-dimensional echocardiography within the first week after admission. All patients had severe apical-wall-motion abnormalities (akinesis or dyskinesis) and left ventricular thrombi. All patients received anticoagulation therapy. Two-dimensional echocardiography, performed one month after the first study, showed that the thrombi had decreased in size in 6 patients and could not be visualized in 1 patient. The noninvasive nature of echocardiography allows serial evaluations of patients with known left ventricular thrombi and permits assessment of the effect of therapy. 相似文献