全文获取类型
收费全文 | 11581篇 |
免费 | 495篇 |
国内免费 | 90篇 |
专业分类
耳鼻咽喉 | 131篇 |
儿科学 | 360篇 |
妇产科学 | 269篇 |
基础医学 | 1300篇 |
口腔科学 | 446篇 |
临床医学 | 786篇 |
内科学 | 2440篇 |
皮肤病学 | 247篇 |
神经病学 | 1005篇 |
特种医学 | 271篇 |
外科学 | 1410篇 |
综合类 | 42篇 |
一般理论 | 2篇 |
预防医学 | 1530篇 |
眼科学 | 514篇 |
药学 | 880篇 |
中国医学 | 33篇 |
肿瘤学 | 500篇 |
出版年
2023年 | 59篇 |
2022年 | 71篇 |
2021年 | 142篇 |
2020年 | 95篇 |
2019年 | 127篇 |
2018年 | 176篇 |
2017年 | 122篇 |
2016年 | 129篇 |
2015年 | 167篇 |
2014年 | 201篇 |
2013年 | 265篇 |
2012年 | 823篇 |
2011年 | 942篇 |
2010年 | 323篇 |
2009年 | 223篇 |
2008年 | 874篇 |
2007年 | 934篇 |
2006年 | 909篇 |
2005年 | 937篇 |
2004年 | 876篇 |
2003年 | 788篇 |
2002年 | 714篇 |
2001年 | 571篇 |
2000年 | 644篇 |
1999年 | 325篇 |
1998年 | 71篇 |
1997年 | 48篇 |
1996年 | 54篇 |
1995年 | 24篇 |
1994年 | 27篇 |
1993年 | 29篇 |
1992年 | 47篇 |
1991年 | 42篇 |
1990年 | 40篇 |
1989年 | 40篇 |
1988年 | 42篇 |
1987年 | 19篇 |
1986年 | 22篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1983年 | 18篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1974年 | 12篇 |
1971年 | 7篇 |
1965年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
A successful case of laparoscopic ileocecal resection is presented. The laparoscopic surgical techniques are described. Advantages, disadvantages and controversial issues surrounding laparoscopic or laparoscopically assisted colorectal surgery are discussed. Reviewing the current literature and the authors' collective clinical experience, the conclusion is that laparoscopic or laparoscopically assisted procedures are clear indications for benign colorectal diseases. The authors believe that these approaches can be employed as palliative measures in malignant diseases or as curative procedures in prospective randomised trials. 相似文献
72.
Auricular alloplastic reconstruction with osteointegrated implants: a new therapy option in microtia
Peiró Ibáñez JL García-Vaquero JA Acosta Farina D Boix-Ochoa J 《Cirugía pediátrica : organo oficial de la Sociedad Espa?ola de Cirugía Pediátrica》2000,13(1):25-29
Microtia has been treated over the years with autogenous tissues, although the results continue to improve, it is technically a very demanding procedure, even in the hands of a well trained surgeon. Osseointegrated implant-supported ear prosthesis, is less demanding, more straightforward, and offers a better cosmetic result. Since 1996 we have treated 8 patients with microtia types III and IV, with titanium osseointegrated implant-supported ear prosthesis in the bone of the mastoid process. The surgical procedure consists in two stages. First stage: when the three titanium screws are drill in the mastoid process of the temporal bone, with a previous CT scan of the area, that is used to measured the bone thickness. Second stage is done 3 to 6 months later. Ear remnants are removed at the beginning of the procedure, three titanium couplings are then secured to the integrated fixtures, a plastic cap is attached to each of the abutments, until healing takes place; three to four weeks later the auricular prosthesis made out of silicone over a metallic structure, will we plug in the titanium screws. Cosmetic results and patients acceptability have been good in all 8 cases, with few postoperative complications. This procedure has become and option for the patients with ear malformations. 相似文献
73.
74.
75.
P C Lara A Rey C Santana J L Afonso J M Diaz G J González R Apolinario 《Radiotherapy and oncology》1998,49(2):163-167
PURPOSE: To assess whether tumour proliferation as measured by Ki67 immunostaining has any predictive value for local control in bladder cancer patients treated by radiotherapy. PATIENTS AND METHODS: Fifty-five patients suffering from infiltrating bladder carcinoma recommended for radical radiotherapy (66 Gy/6-7 weeks) were included in this study. Paraffin-embedded pre-treatment tumour sections were stained with the Ki67 antibody. The percentage of Ki67-positive nuclei was correlated with established prognostic factors, local control and survival. RESULTS: The Ki67 index was not related to local control in our patients when the median was selected as the cut-off value. Patients with tumours with a very low (<27%) Ki67 index had better local control at 5 years (69%) than patients with tumours with greater (>27%) Ki67 expression indices (31.5%) (P<0.05; log-rank test). CONCLUSIONS: Ki67 immunostaining was a feasible method to estimate tumour proliferation. Patients with very low proliferating tumours seemed to achieve better local control after fractionated radiotherapy compared to other patients. Further studies are needed with a greater number of patients to accurately define the role of Ki67 expression in predicting tumour repopulation during fractionated radiotherapy. 相似文献
76.
Campos-Góngora E Viader-Salvadó JM Martínez-Rodríguez HG Zuñiga-Charles MA Galindo JM Said-Fernández S 《Archives of medical research》2000,31(2):162-168
BACKGROUND: Entamoeba histolytica forms cyst-like structures (CLS) in PEHPS but not in TYS-33 medium. Sodium dodecyl sulfate [(SDS (0.1%)] dissolves most of them in 10 min, but not natural cysts. Chitin is responsible mainly for cyst wall resistance. Its synthesis depends on Mg(2)+, Mn(2)+, or Co(2)+, whose action is interactive. With the aid of the Simplex method, we analyzed the effect of 20 blends of these cations to find the one that, when added to PEHPS, produced the highest proportion of CLS resistant to 1% SDS (RCLS). METHODS: The concentration of Mg(2)+, Mn(2)+, and Co(2)+ was determined in PEHPS and TYI-S-33 with a flame atomic absorption spectrometer. The proportion of RCLS produced in PEHPS with each ion blend was tested. The CLS and RCLS affinity to fluorescein wheat germ agglutinin (WGA/FITC), which binds chitin, was determined. RESULTS: PEHPS contained a similar concentration of Co(2)+ (0.52 microM) and 3.4 and 1.6 times more Mg(2)+ (798 microM) and Mn(2)+ (3.15 microM) than TYI-S-33, respectively. The proportion of RCLS increased gradually in PEHPS until reaching 3.6 +/- 1.43% with MgCl(2) 1.22 mM, MnCl(2) 14.44 mM, and CoCl(2) 19.44 mM (ion blend No. 20). Both CLS and RCLS bound WGA/FITC. The RCLS formed in the presence of ion blend No. 20 appeared wrinkled. CONCLUSIONS: Mg(2)+, Mn(2)+, and Co(2)+ enhanced the ability of PEHPS to form RCLS, possibly because these ions stimulated their chitin synthesis. Although ion blend No. 20 produced the highest proportion of RCLS, this high ion concentration may be toxic for encysting amebas. 相似文献
77.
The different subdivisions along the mediolateral extent of the superficial dorsal horn of the spinal cord are generally regarded as identical structures that execute the function of sensory information processing without any significant communication with other regions of the spinal gray matter. In contrast to this standing, here we endeavor to show that neural assemblies along the mediolateral extent of laminae I-IV cannot be regarded as identical structures. After injecting Phaseolus vulgaris leucoagglutinin and biotinylated dextran amine into various areas of the superficial dorsal horn (laminae I-IV) at the level of the lumbar spinal cord in rats, we have demonstrated that the medial and lateral areas of the superficial dorsal horn show the following distinct features in their propriospinal afferent and efferent connections: 1) A 300- to 400-microm-long section of the medial aspects of laminae I-IV projects to and receives afferent fibers from a three segment long compartment of the spinal dorsal gray matter, whereas the same length of the lateral aspects of laminae I-IV projects to and receives afferent fibers from the entire rostrocaudal extent of the lumbar spinal cord. 2) The medial aspects of laminae I-IV project extensively to the lateral areas of the superficial dorsal horn. In contrast to this, the lateral areas of laminae I-IV, with the exception of a few fibers at the segmental level, do not project back to the medial territories. 3) There is a substantial direct commissural connection between the lateral aspects of laminae I-IV on the two sides of the lumbar spinal cord. The medial part of laminae I-IV, however, does not establish any direct connection with the gray matter on the opposite side. 4) The lateral aspects of laminae I-IV appear to be the primary source of fibers projecting to the ipsi- and contralateral ventral horns and supraspinal brain centers. Projecting fibers arise from the medial subdivision of laminae I-IV in a substantially lower number. The findings indicate that the medial and lateral areas of the superficial spinal dorsal horn of rats may play different roles in sensory information processing. 相似文献
78.
László CJ Gombos K Vimláti L Salacz G Hatvani I 《Acta anaesthesiologica Scandinavica》2000,44(4):450-452
BACKGROUND: Regional anaesthesia for ophthalmic surgery is generally accomplished by peri- or retrobulbar techniques. Depending on the duration of ophthalmic surgery, reblock might become necessary. Our goal was to invent a catheter technique for ophthalmic regional anaesthesia that enables the user to administer local anaesthetics intraoperatively into the peri- or retrobulbar space continuously. METHODS: Twenty-five adult cadaver orbits of normal size and anatomy were used for the experiments. A flexible catheter was introduced transcutaneously or transconjunctivally into the extra- or intraconal space. Methylene blue solution was injected through the catheter. RESULTS: Using the same transcutaneous retro- and peribulbar technique, it was possible to introduce flexible catheters into a proper position of the cadaver orbits. The injected dye was found intra- or extraconally. CONCLUSION: Examining the spread of the dye in the orbit, we concluded that it is possible to provide ophthalmic anaesthesia for surgery through an indwelling catheter. We proved that continuous or intermittent administration of a local anaesthetic agent into the extra- or inraconal space can be achieved and this technique may allow us to maintain anaesthesia as long as it is necessary. 相似文献
79.
Gombos K László CJ Hatvani I Vimláti L Salacz G 《Acta anaesthesiologica Scandinavica》2000,44(4):453-456
BACKGROUND: Usually general anaesthesia is chosen if ophthalmic surgery of longer duration is expected. Our goal was to introduce a flexible catheter preoperatively into the extra- or intraconal space and to provide sufficient anaesthesia by continuous administration of a local anaesthetic via the catheter. METHODS: The continuous anaesthetic technique was applied in 28 patients undergoing vitreoretinal surgery. An indwelling catheter was introduced in 20 patients into the intraconal and in 8 patients into the extraconal space. In 6 patients, the position of the catheter was controlled by ultrasound examination prior to the injection of the local anaesthetic agent. RESULTS: For all patients adequate anaesthesia could be achieved and maintained with continuous retrobulbar administration (CRA) of a local anaesthetic by catheter. There were two patients who experienced moderate pain intraoperatively during continuous peribulbar administration (CPA). No complications occurred with the placement of the catheters. The catheter did not disturb the surgeon or the process of the ophthalmic surgery. CONCLUSIONS: Continuous administration of a local anaesthetic agent via an indwelling catheter into the intraconal space allowed ophthalmic anaesthesia without time restriction. Thus, CRA is a good alternative to general anaesthesia for patients undergoing long-lasting ophthalmic surgery. 相似文献
80.
To eliminate undesirable memory traces from the short-term memory system, it is a crucial question to reorganize the activity induced synaptic efficiency. Here we suggest a possible solution for this mechanism. In the first part of the paper we demonstrate, that under different physiological conditions even in the case of adult animals, the GABA(A) synapse may mediate a depolarizing effect on the membrane potential. Considering the GABA(A) receptor-mediated complex effects on the membrane potential of adult mammalian central neurons we raised the question of the properties of the network, which has elements in the synaptic weight matrix with changing signs. The second part pinpoints the beneficial learning ability of such a network. 相似文献