全文获取类型
收费全文 | 2623篇 |
免费 | 174篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 51篇 |
妇产科学 | 34篇 |
基础医学 | 242篇 |
口腔科学 | 26篇 |
临床医学 | 237篇 |
内科学 | 503篇 |
皮肤病学 | 59篇 |
神经病学 | 226篇 |
特种医学 | 234篇 |
外国民族医学 | 1篇 |
外科学 | 298篇 |
综合类 | 80篇 |
一般理论 | 3篇 |
预防医学 | 98篇 |
眼科学 | 537篇 |
药学 | 103篇 |
中国医学 | 2篇 |
肿瘤学 | 95篇 |
出版年
2022年 | 18篇 |
2021年 | 33篇 |
2020年 | 21篇 |
2019年 | 22篇 |
2018年 | 42篇 |
2017年 | 37篇 |
2016年 | 54篇 |
2015年 | 47篇 |
2014年 | 70篇 |
2013年 | 124篇 |
2012年 | 97篇 |
2011年 | 132篇 |
2010年 | 108篇 |
2009年 | 79篇 |
2008年 | 115篇 |
2007年 | 135篇 |
2006年 | 112篇 |
2005年 | 102篇 |
2004年 | 106篇 |
2003年 | 107篇 |
2002年 | 83篇 |
2001年 | 56篇 |
2000年 | 70篇 |
1999年 | 68篇 |
1998年 | 74篇 |
1997年 | 71篇 |
1996年 | 51篇 |
1995年 | 41篇 |
1994年 | 43篇 |
1993年 | 47篇 |
1992年 | 32篇 |
1991年 | 41篇 |
1990年 | 47篇 |
1989年 | 57篇 |
1988年 | 47篇 |
1987年 | 47篇 |
1986年 | 35篇 |
1985年 | 22篇 |
1984年 | 20篇 |
1983年 | 14篇 |
1982年 | 19篇 |
1981年 | 18篇 |
1980年 | 16篇 |
1979年 | 19篇 |
1977年 | 13篇 |
1976年 | 13篇 |
1975年 | 16篇 |
1973年 | 13篇 |
1972年 | 12篇 |
1941年 | 11篇 |
排序方式: 共有2830条查询结果,搜索用时 31 毫秒
31.
Schwarz J. A. Kaboth U. Reikowski H. Jost H. Müting D. Ortmanns H. 《Journal of molecular medicine (Berlin, Germany)》1975,53(11):535-538
Journal of Molecular Medicine - Monomeres IgM, bisher nur bei lymphoproliferativen Autoimmun- und einigen Infektionserkrankungen sowie vereinzelt bei Lebercirrhosen beschrieben, ließ sich... 相似文献
32.
Protective cytotoxic T lymphocyte responses against paramyxoviruses induced by epitope-based DNA vaccines: involvement of IFN-gamma 总被引:1,自引:0,他引:1
Hsu SC; Obeid OE; Collins M; Iqbal M; Chargelegue D; Steward MW 《International immunology》1998,10(10):1441-1447
Plasmid DNA vectors have been constructed with minigenes encoding a single
cytotoxic T lymphocyte (CTL) epitope from either the M2 protein of
respiratory syncytial virus (RSV) or from the nucleoprotein of measles
virus (MV) with or without a signal sequence (also called secretory or
leader sequence). Following intradermal immunization, plasmids in which the
CTL epitopes were expressed in-frame with the signal sequence were more
effective at inducing peptide- and virus- specific CTL responses than
plasmids expressing CTL epitopes without the signal sequence. This
immunization resulted in protection against MV-induced encephalitis and a
significant reduction in viral load following RSV challenge. The reduction
of viral load following RSV challenge was abrogated by prior injection with
anti-IFN-gamma antibodies. These results highlight the ability of
epitope-based DNA immunization to induce protective immune responses to
well-defined epitopes and indicate the potential of this approach for the
development of vaccines against infectious diseases.
相似文献
33.
Recognition of a Nocardia transvalensis complex by resistance to aminoglycosides, including amikacin, and PCR-restriction fragment length polymorphism analysis.
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R W Wilson V A Steingrube B A Brown Z Blacklock K C Jost Jr A McNabb W D Colby J R Biehle J L Gibson R J Wallace Jr 《Journal of clinical microbiology》1997,35(9):2235-2242
Amikacin resistance, rare among nocardiae, was observed in 58 clinical isolates of nocardiae. All of these isolates hydrolyzed hypoxanthine, and 75 to 100% utilized citrate, D-galactose, and D-trehalose as sole carbon sources. Based on utilization of I-erythritol, D-glucitol, i-myo-inositol, D-mannitol, and ribitol and susceptibility to amoxicillin-clavulanic acid, the 58 isolates were separable into four groups. One group was negative for I-erythritol and ribitol and included all the isolates belonging to Nocardia asteroides complex antibiogram type IV. The remaining three groups were positive for I-erythritol and ribitol and were grouped within Nocardia transvalensis. The group that included the type strain was designated N. transvalensis sensu stricto, and the other two groups were designated new taxons 1 and 2. PCR-restriction fragment length polymorphism (RFLP) analysis of a 439-bp segment of the 65-kDa heat shock protein gene with XhoI and HinfI produced identical patterns for 53 (91%) and 58 (100%) isolates, respectively, and differentiated them from all other Nocardia taxa. NarI- and HaeIII-derived RFLP patterns clearly differentiated each of the four biochemically defined taxa. These four groups were also distinguishable by using the chromogenic substrates in Dade MicroScan test panels. By high-performance liquid chromatography, these isolates exhibited the same unique mycolic acid-ester elution patterns that differed from those of all other clinically significant nocardiae. Gas-liquid chromatographic analysis of fatty acids also produced similar patterns for all isolates that distinguished them from all other Nocardia taxa, but did not differentiate the four taxa within the complex. We propose the designation N. transvalensis complex for these four groups of nocardiae, pending further genetic evaluation. 相似文献
34.
Debelenko LV; Brambilla E; Agarwal SK; Swalwell JI; Kester MB; Lubensky IA; Zhuang Z; Guru SC; Manickam P; Olufemi SE; Chandrasekharappa SC; Crabtree JS; Kim YS; Heppner C; Burns AL; Spiegel AM; Marx SJ; Liotta LA; Collins FS; Travis WD; Emmert-Buck MR 《Human molecular genetics》1997,6(13):2285-2290
Lung carcinoids occur sporadically and rarely in association with multiple
endocrine neoplasia type 1 (MEN1). There are no well defined genetic
abnormalities known to occur in these tumors. We studied 11 sporadic lung
carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene
on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy
fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was
studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene
were inactivated. All four tumors showed the presence of a MEN1 gene
mutation and loss of the other allele. Observed mutations included a 1 bp
insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide
substitution affecting a donor splice site. Each mutation predicts
truncation or potentially complete loss of menin. The remaining seven
tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH.
The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a
complex germline MEN1 gene mutation. The data implicate the MEN1 gene in
the pathogenesis of sporadic lung carcinoids, representing the first
defined genetic alteration in these tumors.
相似文献
35.
Paramagnetic macrocyclic chelates show promise as magnetic resonance (MR) imaging contrast agents due to stability and relaxivity comparable to those of DTPA-type chelates. For the three copper and manganese macrocyclic complexes studied in aqueous solution, T1 and T2 relaxivities ranged from 0.14 to 5.88 mM-1sec-1 at 6.25 MHz. In rats, the intravenous administration of 16 mumol/kg of Mn(cyclam) caused the liver T1 relaxation rate to double at 15 minutes after injection. T1 measurements by pulsed MR imaging and manganese analyses on excised tissue showed that both relaxation rate (1/T1) and manganese content of liver and kidney increase linearly with the dosage of Mn(cyclam). The linear relationship between 1/T1 and manganese content can be considered an "in tissue" relaxivity plot for the agent. The resulting relaxivity is 54 mM-1sec-1 in liver, compared with 3.1 mM-1sec-1 in aqueous solution. Although this work is preliminary, the implication for medical MR imaging applications is that macrocyclic contrast agents can be effective at approximately one-tenth the current typical dose used for gadolinium DTPA. 相似文献
36.
Identification of mycobacteria by high-performance liquid chromatography. 总被引:3,自引:40,他引:3
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mycolic acids extracted from saponified mycobacterial cells were examined as p-bromophenacyl esters by high-performance liquid chromatography (HPLC). Standard HPLC patterns were developed for species of Mycobacterium by examination of strains from culture collections and other well-characterized isolates. Relative retention times of peaks and peak height comparisons were used to develop a differentiation scheme that was 98% accurate for the species examined. A rapid, cost-effective HPLC method which offers an alternative approach to the identification of mycobacteria is described. 相似文献
37.
38.
Digital conventional tomography may be performed using a digital vascular imaging (DVI) system. Digital synthesis and removal of blur from multiple tomographic sections were accomplished by computer with a single motion of the source-receptor (x-ray tube-image intensifier) complex. Tomographic application of a DVI system was evaluated by phantom simulations. 相似文献
39.
S. Jost W. Rafflenbeul J. Deckers B. Wiese H. Hecker P. Nikutta P. Lippolt P. Lichtlen 《European journal of epidemiology》1992,8(Z1):107-119
Animal experiments suggest an inhibitory effect of calcium entry blockers on arterial calcinosis and the formation of atherosclerotic plaques. Experiments with isolated tissues suggest various mechanisms for an antiatherosclerotic effect of calcium entry blockers.INTACT, the International Nifedipine Trial on Antiatherosclerotic Therapy, is the first study investigating, with a prospective, placebo-controlled, randomized, double-blind design, the influence of a calcium entry blocker (nifedipine 80 mg/day) on the progression of coronary atherosclerosis in patients with proven coronary artery disease. Study endpoints were changes of established coronary stenoses (diameter reduction 20%), as well as the formation of new stenoses as documented by coronary angiography. Standardized coronary angiograms were taken before and after a treatment period of 3 years. The angiograms were quantitatively analyzed with the computer-assisted edge detection system CHAS. Of the 425 patients included in the study, 282 patients (134 on nifedipine and 148 on placebo) revealed no protocol violations. In the inclusion angiograms of these patients, 893 coronary stenoses were detected which were not significantly influenced in their development by nifedipine. However, 196 entirely new coronary lesions, 185 stenoses and 11 occlusions, were found in the follow-up angiograms. There were 78 lesions in 54 patients (40%) on nifedipine (0.58 new lesions/patient) and 118 lesions in 73 patients (49%; n.s.) on placebo (0.8 new lesions/patient; p = 0.031). 相似文献
40.
R Spencer W L Hutton W B Snyder D G Fuller G E Fish A Vaiser B F Jost 《Ophthalmic surgery》1992,23(11):766-769
In an effort to minimize surgical and visual morbidity of cryotherapy for retinopathy of prematurity (ROP), 18 eyes of 13 patients with 3 to 7 clock hours of stage 3 ROP with "plus" disease were treated by cryotherapy applications limited to the avascular retina adjacent to the areas of stage 3 disease. In 17 of 18 eyes, this limited use of cryotherapy was sufficient to cause regression of ROP without further treatments. After at least 3 months follow-up, ROP outcome showed a normal macular appearance in 16 eyes; two eyes developed macular dragging; no retinal detachments occurred. 相似文献