全文获取类型
收费全文 | 3408篇 |
免费 | 226篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 88篇 |
妇产科学 | 84篇 |
基础医学 | 534篇 |
口腔科学 | 59篇 |
临床医学 | 364篇 |
内科学 | 720篇 |
皮肤病学 | 118篇 |
神经病学 | 357篇 |
特种医学 | 130篇 |
外科学 | 304篇 |
综合类 | 15篇 |
预防医学 | 242篇 |
眼科学 | 36篇 |
药学 | 234篇 |
中国医学 | 9篇 |
肿瘤学 | 338篇 |
出版年
2023年 | 37篇 |
2022年 | 63篇 |
2021年 | 118篇 |
2020年 | 79篇 |
2019年 | 93篇 |
2018年 | 104篇 |
2017年 | 98篇 |
2016年 | 123篇 |
2015年 | 121篇 |
2014年 | 144篇 |
2013年 | 176篇 |
2012年 | 277篇 |
2011年 | 293篇 |
2010年 | 160篇 |
2009年 | 140篇 |
2008年 | 214篇 |
2007年 | 190篇 |
2006年 | 178篇 |
2005年 | 178篇 |
2004年 | 141篇 |
2003年 | 122篇 |
2002年 | 98篇 |
2001年 | 44篇 |
2000年 | 54篇 |
1999年 | 42篇 |
1998年 | 21篇 |
1997年 | 26篇 |
1996年 | 18篇 |
1995年 | 12篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 14篇 |
1991年 | 14篇 |
1990年 | 20篇 |
1989年 | 20篇 |
1988年 | 14篇 |
1987年 | 9篇 |
1986年 | 14篇 |
1985年 | 10篇 |
1984年 | 6篇 |
1983年 | 13篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 13篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1971年 | 6篇 |
1970年 | 6篇 |
1969年 | 9篇 |
排序方式: 共有3651条查询结果,搜索用时 15 毫秒
1.
2.
J. M. Johnston P. Grondziowski R. M. Windisch R. A. Eder L. Lytle 《Acta diabetologica》1995,32(4):213-216
A feasibility study was undertaken to evaluate laboratory phlebotomists performing bedside glucose monitoring (BGM) over a
3-month period on a medical and surgical floor. Specific questions included: feasibility of providing testing on a 24-h basis,
accuracy, appropriate utilization, effect on patient care, and an analysis of cost. In all, 1975 tests were performed on 114
patients. BGM results were within 15% of the laboratory's result 97% of the time. Patient and physician satisfaction was high.
Although the cost of BGM is slightly higher than a laboratory glucose test, its use appeared to reduce the length of hospital
stay by 0.47 days. Practical information on initiating a highly successful BGM program is provided. 相似文献
3.
Bernd Huber Ines Hauser Verena Horstmann Gabi Jokeit Sylvia Liem Theodor May Thomas Meinert Enrique Robertson Heide Schorlemmer Wolfgang Wagner Michael Seidel 《Seizure》2007,16(1):35-42
This study was designed to describe the course of epilepsy (in terms of seizure frequency) and to assess the variables (antiepileptic therapy regimens and others) correlated to improvement. Seizure frequency (categories: seizure free, more than one seizure/year, monthly seizures, weekly seizures and daily seizures) and antiepileptic medication were retrospectively compared between 1992 and 2002 in a large cohort of 550 inpatients with chronic epilepsy and different degrees of intellectual disability or multiple handicaps. RESULTS: Seizure frequency decreased significantly (p<0.001). 218 of the 394 patients (55.3%) not seizure free in 1992 improved (changed into a better frequency category). The improvement rate was marginally higher in patients who had undergone a medication change (p=0.08). A high seizure frequency in 1992 (p=0.016) and older age (p=0.006), but not epilepsy syndrome or degree of intellectual disability, were predictors for improvement (stepwise logistic regression analysis). 56.4% of the improved patients were on combinations of two AEDs (17.4%, monotherapy; 20.2%, triple therapy). The most frequent therapy regimens in the improved patients were lamotrigine/valproate (48 patients), carbamazepine/phenobarbital (21) and carbamazepine only (19). Lamotrigine/valproate was effective in all kinds of epileptic syndromes. Most patients on lamotrigine had serum concentrations above 10microg/ml, approximately one half had dosages above 200mg/day. The rate of seizure freedom increased from 28.4 to 37.6%. The 84% of the patients seizure free in 1992 remained seizure free. Predictors for seizure freedom in 2002 were higher age (stepwise logistic regression, p<0.0005) and seizure freedom in 1992 (p<0.0005). CONCLUSIONS: Substantial improvement can be achieved even in intellectually disabled patients with chronic epilepsy. Although the rate of seizure freedom is reduced in comparison with a non-ID population, once seizure freedom has been achieved it is most likely to continue. For a majority of this patient population, monotherapy may not be sufficient. Lamotrigine/valproate appears to be a major therapeutic innovation. 相似文献
4.
Bacterial ghosts (BGs) are empty bacterial envelopes of Gram-negative bacteria produced by controlled expression of cloned gene E, forming a lysis tunnel structure within the envelope of the living bacteria. BGs are devoid of cytoplasmic content and possess all bacterial bio-adhesive surface properties in their original state while not posing any infectious threat. BGs are ideally suited as an advanced drug delivery system (ADDS) for toxic substances in tumor therapy. The inner space of BGs can be loaded with either single components or combinations of peptides, drugs or DNA which provides an opportunity to design new types of (polyvalent) drug delivery vehicles. Uptake of BGs loaded with Doxorubicin (Dox) by CaCo2 cells led to effective Dox release from endo-lysosomal compartments and accumulation in the nucleus. Viability and proliferative capacity of the cells were significantly decreased (2–3 orders of magnitude) after internalization of Dox loaded BGs as compared to cells incubated with free Dox. The same effect was observed with leukemia cells. Melanoma cells also revealed a high capability to internalize BGs. These results indicate that BGs are able to target a range of types of cancer. BGs have also been investigated as DNA delivery vectors. Studies show DNA loaded BGs are efficiently phagocytosed and internalized by both professional APCs and tumor cells with up to 82% of cells expressing the plasmid-encoded reporter gene. Our studies with BGs as an ADDS system contribute (i) to optimize drug delivery for the treatment of cancer; (ii) define specific conditions for selection and preparation of BG formulations; (iii) and provide a background for the clinical application of BGs in cancer therapy. 相似文献
5.
Using the whole-cell configuration of the patch clamp technique, calcium-activated potassium currents (IK,Ca) were investigated in ramified murine brain macrophages. In order to induce IK,Ca the intracellular concentration of nominal free Ca2+ was adjusted to 1μM. The Ca2+-activated K+ current of brain macrophages did not show any voltage dependence at test potentials between –120 and +30mV. A tenfold change
in extracellular K+ concentration shifted the reversal potential of IK,Ca by 51mV. The bee venom toxin apamin applied at concentrations of up to 1μM did not affect IK,Ca. Ca2+-activated K+ currents of ramified brain macrophages were highly sensitive to extracellularly applied charybdotoxin (CTX). The half-maximal
effective concentration of CTX was calculated to be 4.3nM. In contrast to CTX, the scorpion toxin kaliotoxin did not inhibit
IK,Ca at concentrations between 1 and 50nM. Tetraethylammonium (TEA) blocked 8.0% of IK,Ca at a concentration of 1mM, whereas 31.4% of current was blocked by 10mM TEA. Several inorganic polyvalent cations were tested
at a concentration of 2mM for their ability to block IK,Ca. La3+ reduced IK,Ca by 72.8%, whereas Cd2+ decreased IK,Ca by 17.4%; in contrast, Ni2+ did not have any effect on IK,Ca. Ba2+ applied at a concentration of 1mM reduced IK,Ca voltage-dependently at hyperpolarizing potentials.
Received: 17 January / Accepted: 5 May 1997 相似文献
6.
7.
Kathrin Scherer Wolfgang Studer Verena Figueiredo Andreas J Bircher 《Annals of allergy, asthma & immunology》2006,96(3):497-500
BACKGROUND: Blue dyes used for lymphatic mapping in sentinel lymph node biopsy cause intraoperative anaphylactic reactions in up to 2.7% of patients. With increasing implementation of this technique, the incidence of anaphylaxis to these dyes can be expected to increase. In the literature, the chemically often unrelated and inconsistently designated dyes have been confused, adding to other inconsistencies in the nomenclature. OBJECTIVE: To demonstrate the nomenclature, chemical and physiologic differences, and allergenicity of the various blue dyes used in a medical context. METHODS: We describe a patient with an intraoperative grade IV anaphylactic reaction to isosulfan blue. Immediate-type hypersensitivity was proved by positive skin test reactions and CD63 expression to isosulfan blue and cross-reactivity to patent blue V. RESULTS: A review of the literature clarified the exact nomenclature of the blue dyes and the possible pitfalls of confusing nomenclature in the context of structurally closely related dyes with different allergenic properties. For the detection of type I hypersensitivity, intracutaneous tests are valuable tools. An IgE-mediated mechanism has been shown recently. In most cases, sensitization exists without known previous exposure in a medical context. This may be due to the widespread use of such dyes in objects of everyday life. Preoperative antiallergic medication use does not prevent anaphylactic reactions but apparently reduces their severity. CONCLUSION: For better comparison and precision, the Chemical Abstracts Service number of the respective dye should always be given. 相似文献
8.
The effects of recombinant human erythropoietin (rhEPO, RecormonR, CAS 122312-54-3) on the differential leucocyte counts and platelets of rabbits were investigated after the repeated application of a single dose of rhEPO. Therefore, 150 IU rhEPO (n = 5), 300 IU rhEPO (n = 6), or 600 IU rhEPO (n = 5) per animal was injected once on three separate occasions with an interval of 5–6 weeks between each injection. Six animals were used to study the potential effect of the solvent alone.rhEPO showed a significant time effect on the differential leucocyte counts and platelets of rabbits. The decrease in total white blood cells count (WBC) on the third, fourth and sixth day after rhEPO administration was due to a decrease in lymphocytes. These results support the hypothesis that the enhanced demand of one cell line leads to a down-modulation of the production of other cell line(s). 相似文献
9.
10.
Propagation of hepatitis A virus in human embryo fibroblasts 总被引:8,自引:0,他引:8
Verena Gauss-Müller Gert G. Frisner Friedrich Deinhardt 《Journal of medical virology》1981,7(3):233-239
human diploid fibroblasts and human primary liver cell carcinoma cells (PLC/PRF/5) were infected with hepatitis A virus (HAV) adapted to growth in cell culture or derived directly from human stool. Viral antigen was expressed in PLC/PRF/5 cells 28 days after infection with cell culture-adapted HAV, and 50 days after infection with virus from human stool. In human fibroblasts the periods until first expression of viral antigen were 90 and 210 days, respectively. During further passages of HAV in fibroblasts the time of first appearance of antigen decreased to about 28 days. Biophysical properties of HAV extracted from infected fibroblasts were comparable to those of HAV derived directly from human stool. Immunofluorescence studies showed that the antigen was located exclusively within the cytoplasm of the infected fibroblasts. Kinetics of antigen production indicated that an equilibrium between virus multiplication and cell metabolism was reached in persistently infected fibroblasts. 相似文献