全文获取类型
收费全文 | 3141篇 |
免费 | 188篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 90篇 |
妇产科学 | 101篇 |
基础医学 | 486篇 |
口腔科学 | 134篇 |
临床医学 | 276篇 |
内科学 | 723篇 |
皮肤病学 | 18篇 |
神经病学 | 216篇 |
特种医学 | 69篇 |
外科学 | 506篇 |
综合类 | 41篇 |
预防医学 | 164篇 |
眼科学 | 29篇 |
药学 | 206篇 |
中国医学 | 7篇 |
肿瘤学 | 239篇 |
出版年
2023年 | 20篇 |
2022年 | 42篇 |
2021年 | 88篇 |
2020年 | 45篇 |
2019年 | 83篇 |
2018年 | 88篇 |
2017年 | 57篇 |
2016年 | 83篇 |
2015年 | 72篇 |
2014年 | 111篇 |
2013年 | 150篇 |
2012年 | 257篇 |
2011年 | 257篇 |
2010年 | 168篇 |
2009年 | 135篇 |
2008年 | 205篇 |
2007年 | 195篇 |
2006年 | 197篇 |
2005年 | 192篇 |
2004年 | 175篇 |
2003年 | 127篇 |
2002年 | 130篇 |
2001年 | 23篇 |
2000年 | 17篇 |
1999年 | 35篇 |
1998年 | 18篇 |
1997年 | 26篇 |
1996年 | 18篇 |
1995年 | 17篇 |
1994年 | 17篇 |
1993年 | 13篇 |
1992年 | 26篇 |
1991年 | 22篇 |
1990年 | 16篇 |
1989年 | 9篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 12篇 |
1985年 | 17篇 |
1984年 | 13篇 |
1982年 | 12篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 11篇 |
1978年 | 15篇 |
1977年 | 11篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 12篇 |
1967年 | 6篇 |
排序方式: 共有3351条查询结果,搜索用时 31 毫秒
1.
Carlo Bastianelli V. Bruni Ivo Brosens Giuseppe Benagiano 《Expert review of clinical pharmacology》2020,13(2):163-182
ABSTRACTIntroduction: Steroid hormones are responsible for specific changes in the endometrium during the menstrual cycle, when they are sequentially secreted and, because of this, in the early days sequential combined oral contraceptive regimens were utilized. The same basic concept has been utilized with multi-phasic regimens, in order to produce endometrial pictures mimicking the normal cycle.Areas covered: The Endometrial effects of progestins and estrogens; combined monophasic high- (50 μg), medium- (30 μg), low- (20 μg), ultralow- (15 μg) estrogen content; sequential regimens; multiphasic combinations; treatment schedules.Cervical effects of combined high-dose and sequential combinations, including evidence for an increase in malignant lesions.Expert opinion: Overall, combined oral contraceptives (COCs) inhibit normal proliferative changes and the endometrium becomes thin, narrow, with widely spaced glands and pre-decidual changes in the stroma. During the first few cycles the progestin induces a coexistence of proliferative and secretory features; with time, the picture changes because the progestin induces a down-regulation of estrogen receptors, resulting in tortuous glands similar to those in the secretory phase, but characterized by a quiescent, atrophic glandular epithelium.In the cervical epithelium, under the influence of high-dose COCs, endocervical glands became hypersecretory and in some instances, distinctive type of atypical polypoid endocervical hyperplasia is found. 相似文献
2.
3.
BACKGROUND: Malignant peripheral epineurial tumours are a group of tumours that derive histomorphologically from peripheral nerve sheaths. They occur sporadically, with an incidence of approximately 0.001%, and very rarely require emergency operation. PATIENT AND PROCEDURE: An athletic 19-year-old man presented to an orthopaedic outpatient clinic with lumboischialgia and weakness of the third and fourth left toes. A 12 x 10 x 8-cm paravertebral/retroperitoneal tumour was diagnosed by CT, and the patient was referred to our clinic. For classification, CT-assisted puncture of the tumour was carried out. A haemorrhage into the tumour resulted from the puncture, with consequently lower Hb level and progressive peripheral sensomotoric deficits demanding emergency surgery on a weekend. On this occasion, the tumour was resected together with the L5 and S1 nerve roots through cooperation between the general surgical and neurosurgical departments and was classified as a malignant peripheral epineurial tumour in the rapid stage. Due to the spinal R2 resection, after-loading probes were inserted and the tumour bed was clip-marked. Percutaneous radiotherapy and brachytherapy followed postoperatively. Shortly afterwards, relaparotomy had to be performed due to an adhesive ileus, from which the patient recovered quickly. Chemotherapy was carried out due to a G2 tumour classification. The patient is currently undergoing rehabilitation, during which the peripheral neurological deficits are improving gradually. CONCLUSION: This rare case of a malignant peripheral epineurial tumour with acute symptoms demonstrates the ability of hospitals with maximum care facilities to maintain services even in times of financial cuts in health care services. 相似文献
4.
Ivo W Graziadei 《Tropical gastroenterology》2007,28(2):45-50
Initially living donor liver transplantation (LDLT) was almost exclusively performed in infants and children. Adult LDLT programmes were initiated several years later. In the west this programme was introduced in view of a critical shortage of deceased donors and a constant increase in waiting list mortality. At present, this procedure is accepted as a therapeutic option for patients with end-stage liver disease to make up for the shortage of donor organs from dead patients. In Asia, however, LDLT has become the predominant means of liver transplantation as donor organs from the diseased cannot be used for religious and ethical reasons. Although there have been significant improvements in surgical techniques and consequently in recipient outcome over recent years, the LDLT procedure is still associated with donor morbidity and even mortality. The overall reported donor mortality was 0.2% and donor morbidity ranged between 0% and 100%. Biliary complications and infections were the most commonly reported donor complications. Therefore, a thorough medical as well as psychological evaluation of the donor and recipient are necessary prior to this procedure. To date, LDLT comprises less than 5% of adult liver transplantations in Europe and in the United States. Recipient and graft survival are almost identical to those seen with liver transplantations from deceased donors (DD). Biliary and vascular complications are more often seen in the LDLT setting. So far, no studies have focussed on the impact of LDLT on waiting list mortality. There is international consensus that this procedure should be restricted to centres with large experience in deceased donor liver transplantations as well as in hepatobiliary surgery. Ethical issues, optimal utility and application of adult LDLT and optimal recipient and donor characteristics have yet to be defined. 相似文献
5.
6.
An open trial was carried out in eight healthy male and female volunteers to examine the bioavailability as well as the main kinetic parameters of Migr?nerton (metoclopramide and paracetamol; CAS 364-64-5 and CAS 103-90-2, resp). in comparison with reliable literature data. The results reported here clearly show that the absorption of both active ingredients from the fixed combination is complete and that therapeutically relevant plasma concentrations are achieved within 30 min. Bioavailability as well as tmax, t1/2, and time-lag are comparable with data resulting from reliable and internationally acknowledged kinetic studies. The fixed combination was shown to be kinetically compatible with regard to all parameters determined for metoclopramide and paracetamol. 相似文献
7.
8.
9.
Allan J. MacKenzie-Graham Erh-Fang Lee Ivo D. Dinov Heng Yuan †Russell E. Jacobs Arthur W. Toga 《Epilepsia》2007,48(S4):75-81
Summary: Naturally occurring mutants and genetically manipulated strains of mice are widely used to model a variety of human diseases. Atlases are an invaluable aid in understanding the impact of such manipulations by providing a standard for comparison and to facilitate the integration of anatomic, genetic, and physiologic observations from multiple subjects and experiments. We have developed digital atlases of the C57BL/6J mouse brain (adult and neonate) as comprehensive frameworks for storing and accessing the myriad types of information about the mouse brain. Along with raw and annotated images, these contain database management systems and a set of tools for comparing information from different techniques and different animals. Each atlas establishes a canonical representation of the mouse brain and provides the tools for the manipulation and analysis of new data. We describe both these atlases and discuss how they may be put to use in organizing and analyzing data from mouse models of epilepsy. 相似文献
10.
Siamak Mohammadi Emre Belli Ivo Martinovic Lucile Houyel André Capderou Jérome Petit Claude Planché Alain Serraf 《European journal of cardio-thoracic surgery》2005,28(2):217-222
OBJECTIVE: To identify the surgical approaches and risk factors which influence longevity of right ventricle to pulmonary artery (RV-PA) conduits following first reoperation for obstruction. METHODS: Between January 1993 and August 2003, 114 patients underwent 141 reoperations for RV-PA conduit obstruction. Diagnoses included 'Truncus Arteriosus' (n=52), 'Pulmonary atresia/Tetralogy of fallot' (n=39), 'Double outlet right ventricle' (n=10), 'Transposition of great arteries, VSD, and pulmonary atresia' (n=9), and the 'Ross operation' (n=4). All patients had undergone a previous biventricular repair. The first reoperation for conduit obstruction was performed in 112 hospital survivors by: total conduit replacement (Group A, n=73) with valved (homograft=10 and xenograft=54) or non-valved (n=9) conduit, and patch enlargement of the obstructed RV outflow tract with preservation of the posterior and sides of the conduit wall after removing of the fibrocalcific peel and degenerated valve (Group B, n=39). Mean age at first reoperation was 8.8+/-6.7 and 7.5+/-5.3 years in patients of groups A and B, respectively. Seven patients in Group A and 18 in Group B required a second reoperation and two patients in Group B a third reoperation. RESULTS: There were two hospital deaths and no late deaths. Mean follow-up was 5.8+/-3.2 years. Risk factors for second reoperation by univariate analysis were: homograft conduit use (P=0.004), Group B surgical approach (P=0.0001), higher RV-PA systolic pressure gradient at discharge (P=0.02), and age <5-years-old (P=0.01). Multivariate analysis showed that inclusion in Group B and younger age (<5-years-old) at repair were independent risk factors for second reoperation. Group B surgical approaches had higher RV-PA systolic pressure gradient at discharge (P=0.02) and required more PA bifurcation repair at the time of second reoperation (P=0.05). Freedom from second reoperation for conduit obstruction was significantly higher in Group A patients at 5 and 8 years (P<0.04) and those with xenografts rather than homograft (P=0.04). CONCLUSIONS: Our results support the optimal surgical approach for RV-PA conduit obstruction is total replacement with a xenograft. RV outflow reconstruction by other techniques without complete dissection of PA bifurcation does not completely relieve the stenosis and could cause early restenosis. Higher systolic gradients at discharge and younger age at first reoperation are predictors of earlier reoperation. 相似文献