全文获取类型
收费全文 | 3266篇 |
免费 | 174篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 152篇 |
妇产科学 | 272篇 |
基础医学 | 326篇 |
口腔科学 | 47篇 |
临床医学 | 257篇 |
内科学 | 668篇 |
皮肤病学 | 38篇 |
神经病学 | 293篇 |
特种医学 | 81篇 |
外科学 | 502篇 |
综合类 | 13篇 |
一般理论 | 1篇 |
预防医学 | 130篇 |
眼科学 | 97篇 |
药学 | 190篇 |
中国医学 | 1篇 |
肿瘤学 | 350篇 |
出版年
2023年 | 8篇 |
2022年 | 17篇 |
2021年 | 58篇 |
2020年 | 34篇 |
2019年 | 46篇 |
2018年 | 77篇 |
2017年 | 54篇 |
2016年 | 55篇 |
2015年 | 74篇 |
2014年 | 89篇 |
2013年 | 140篇 |
2012年 | 178篇 |
2011年 | 196篇 |
2010年 | 114篇 |
2009年 | 91篇 |
2008年 | 186篇 |
2007年 | 242篇 |
2006年 | 242篇 |
2005年 | 254篇 |
2004年 | 245篇 |
2003年 | 235篇 |
2002年 | 188篇 |
2001年 | 33篇 |
2000年 | 35篇 |
1999年 | 29篇 |
1998年 | 42篇 |
1997年 | 24篇 |
1996年 | 35篇 |
1995年 | 42篇 |
1994年 | 30篇 |
1993年 | 35篇 |
1992年 | 24篇 |
1991年 | 22篇 |
1990年 | 14篇 |
1989年 | 13篇 |
1988年 | 14篇 |
1987年 | 16篇 |
1986年 | 20篇 |
1985年 | 12篇 |
1984年 | 22篇 |
1983年 | 25篇 |
1982年 | 16篇 |
1981年 | 21篇 |
1980年 | 15篇 |
1979年 | 8篇 |
1978年 | 16篇 |
1977年 | 18篇 |
1976年 | 8篇 |
1974年 | 7篇 |
1973年 | 7篇 |
排序方式: 共有3454条查询结果,搜索用时 781 毫秒
81.
Midodrine is an alpha-agonist that causes peripheral vasoconstriction, resulting in increased blood pressure. It has been reported to be safe and effective in patients with end stage renal disease (ESRD) and is widely used for hemodialysis-associated hypotension. We report a case report of midodrine-induced ischemia in a patient on hemodialysis and review the literature relating to the safety of midodrine in patients with end stage renal disease. 相似文献
82.
An association between symptomatic compression neuropathy of the median nerve at the carpal tunnel and "trigger finger" has been reported in endocrine and metabolic disorders. We assessed the incidence of increased median nerve latency in subjects with "trigger finger". 62 consecutive patients with "trigger finger" and no signs or symptoms of median nerve compression underwent nerve conduction studies of the median nerve. 13 healthy adults served as controls. 39/62 patients had increased distal motor latency in the median nerve. Only 1 of 13 subjects in the control group had a borderline value of distal motor latency. 相似文献
83.
Jonathan Guez Jonathan Cohen Moshe Naveh-Benjamin Asher Shiber Yan Yankovsky Rotem Saar Hadar Shalev 《Psychiatry research》2013
Stress and episodic memory impairment have previously been associated. Acute stress disorder (ASD) is a maladaptive stress response, which develops in some individuals following traumatic life events. Recently, the authors demonstrated a specific deficit in associative memory for emotionally neutral stimuli in ASD and posttraumatic stress disorder (PTSD). This study further tested the relationship between this memory impairment and the course of ASD. We assessed new learning and memory for item and associative information in patients diagnosed with ASD (n=14) and matched trauma naïve controls (n=14). Memory performance and posttraumatic symptoms were examined for approximately 1 and 10 week periods following the traumatic experience. In the two experiments, participants studied a list of stimuli pairs (verbal or visual) and were then tested for their memory of the items (item recognition test), or for the association between items in each pair (associative recognition test). In both experiments, ASD patients showed a marked associative memory deficit compared to the control group. After 10 weeks, ASD symptoms were resolved in most patients. Interestingly, their performance on associative recognition for verbal stimuli improved, while the associative deficit for visual stimuli remained unchanged. Potential mechanisms underlying such an associative memory deficit in post-trauma patients are discussed. 相似文献
84.
85.
Structural characterization of Campylobacter jejuni lipooligosaccharide outer cores associated with Guillain-Barre and Miller Fisher syndromes
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Godschalk PC Kuijf ML Li J St Michael F Ang CW Jacobs BC Karwaski MF Brochu D Moterassed A Endtz HP van Belkum A Gilbert M 《Infection and immunity》2007,75(3):1245-1254
Molecular mimicry between lipooligosaccharides (LOS) of Campylobacter jejuni and gangliosides in peripheral nerves plays a crucial role in the pathogenesis of C. jejuni-related Guillain-Barré syndrome (GBS). We have analyzed the LOS outer core structures of 26 C. jejuni strains associated with GBS and its variant, Miller Fisher syndrome (MFS), by capillary electrophoresis coupled with electrospray ionization mass spectrometry. Sixteen out of 22 (73%) GBS-associated and all 4 (100%) MFS-associated strains expressed LOS with ganglioside mimics. GM1a was the most prevalent ganglioside mimic in GBS-associated strains (10/22, 45%), and in eight of these strains, GM1a was found in combination with GD1a mimics. All seven strains isolated from patients with ophthalmoplegia (GBS or MFS) expressed disialylated (GD3 or GD1c) mimics. Three out of 22 GBS-associated strains (14%) did not express sialylated ganglioside mimics because their LOS locus lacked the genes necessary for sialylation. Three other strains (14%) did not express ganglioside mimics because of frameshift mutations in either the cstII sialyltransferase gene or the cgtB galactosyltransferase gene. It is not possible to determine if these mutations were already present during C. jejuni infection. This is the first report in which mass spectrometry combined with DNA sequence data were used to infer the LOS outer core structures of a large number of neuropathy-associated C. jejuni strains. We conclude that molecular mimicry between gangliosides and C. jejuni LOS is the presumable pathogenic mechanism in most cases of C. jejuni-related GBS. However, our findings suggest that in some cases, other mechanisms may play a role. Further examination of the disease etiology in these patients is mandatory. 相似文献
86.
87.
88.
We compared exhaled breath condensate (EBC) and induced sputum (IS) for assessing inflammation in pulmonary diseases in patients
with obstructive lung disease (n = 20), persistent cough >6 months (n = 20), interstitial lung disease (n = 25) and controls (n = 10). EBC was collected by suspending a Teflon perfluoroalkoxy tube installed in an ice-filled container and connected to
a polypropylene test tube. IS was recovered after 20’ inhalation of 3% saline with an ultrasonic nebulizer, and 300 cells
were differentially counted in cytospin Giemsa-stained slides. H202 was measured by a method based on oxidation of phenolsulfonphthalein (phenol red) mediated by horseradish peroxidases and
H202. Pulmonary function tests were performed by conventional methods. H202 levels in EBC and % eosinophils in IS were significantly different between groups. A positive and significant correlation
was found between % eosinophils in IS and the levels of H202 in EBC for each group and for all patients combined. 相似文献
89.
Tang Y Saul A Gur M Goei S Wong E Ersoy B Snodderly DM 《Journal of neurophysiology》2007,97(5):3439-3448
Studies of visual function in behaving subjects require that stimuli be positioned reliably on the retina in the presence of eye movements. Fixational eye movements scatter stimuli about the retina, inflating estimates of receptive field dimensions, reducing estimates of peak responses, and blurring maps of receptive field subregions. Scleral search coils are frequently used to measure eye position, but their utility for correcting the effects of fixational eye movements on receptive field maps has been questioned. Using eye coils sutured to the sclera and preamplifiers configured to minimize cable artifacts, we reexamined this issue in two rhesus monkeys. During repeated fixation trials, the eye position signal was used to adjust the stimulus position, compensating for eye movements and correcting the stimulus position to place it at the desired location on the retina. Estimates of response magnitudes and receptive field characteristics in V1 and in LGN were obtained in both compensated and uncompensated conditions. Receptive fields were narrower, with steeper borders, and response amplitudes were higher when eye movement compensation was used. In sum, compensating for eye movements facilitated more precise definition of the receptive field. We also monitored horizontal vergence over long sequences of fixation trials and found the variability to be low, as expected for this precise behavior. Our results imply that eye coil signals can be highly accurate and useful for optimizing visual physiology when rigorous precautions are observed. 相似文献
90.
Katz O Gil L Lifshitz L Prutchi-Sagiv S Gassmann M Mittelman M Neumann D 《European journal of immunology》2007,37(6):1584-1593
Erythropoietin (Epo) is the main erythropoietic hormone. Recombinant human Epo (rHuEpo) is thus used in clinical practice for the treatment of anemia. Accumulating data reveals that Epo exerts pleiotropic activities. We have previously shown an anti-neoplastic activity of Epo in murine multiple myeloma (MM) models, and in MM patients. Our findings that this anti-neoplastic effect operates via CD8+ T lymphocytes led us to hypothesize that Epo possesses a wider range of immunomodulatory functions. Here we demonstrate the effect of Epo on B lymphocyte responses, focusing on three experimental models: (i) tumor-bearing mice, (5T2 MM mouse); (ii) antigen-injected healthy mice; and (iii) antigen-injected transgenic mice (tg6), overexpressing human Epo. In the MM model, despite bone marrow dysfunction, Epo-treated mice retained higher levels of endogenous polyclonal immunoglobulins, compared to their untreated controls. In both Epo-treated wild type and tg6 mice, Epo effect was manifested in the higher levels of splenocyte proliferative response induced in vitro by lipopolysaccharide. Furthermore, these mice had increased in vivo production of anti-dinitrophenyl (DNP) antibodies following immunization with DNP-keyhole limpet hemocyanin. Epo-treated mice showed an enhanced immune response also to the clinically relevant hepatitis B surface antigen. These findings suggest a potential novel use of rHuEpo as an immunomodulator. 相似文献