全文获取类型
收费全文 | 1416篇 |
免费 | 106篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 24篇 |
妇产科学 | 50篇 |
基础医学 | 232篇 |
口腔科学 | 12篇 |
临床医学 | 169篇 |
内科学 | 244篇 |
皮肤病学 | 19篇 |
神经病学 | 143篇 |
特种医学 | 38篇 |
外科学 | 98篇 |
综合类 | 8篇 |
一般理论 | 1篇 |
预防医学 | 171篇 |
眼科学 | 12篇 |
药学 | 144篇 |
中国医学 | 3篇 |
肿瘤学 | 147篇 |
出版年
2023年 | 20篇 |
2022年 | 16篇 |
2021年 | 35篇 |
2020年 | 39篇 |
2019年 | 66篇 |
2018年 | 48篇 |
2017年 | 39篇 |
2016年 | 35篇 |
2015年 | 51篇 |
2014年 | 64篇 |
2013年 | 87篇 |
2012年 | 98篇 |
2011年 | 99篇 |
2010年 | 70篇 |
2009年 | 50篇 |
2008年 | 86篇 |
2007年 | 81篇 |
2006年 | 65篇 |
2005年 | 67篇 |
2004年 | 69篇 |
2003年 | 58篇 |
2002年 | 52篇 |
2001年 | 11篇 |
2000年 | 12篇 |
1999年 | 10篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 14篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1979年 | 3篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1967年 | 2篇 |
排序方式: 共有1526条查询结果,搜索用时 15 毫秒
51.
Birgit Alsbjerg Thor Haahr Helle O Elbaek Rita Laursen Betina B Povlsen Peter Humaidan 《Reproductive biomedicine online》2019,38(5):677-682
Research question
What are the reproductive outcomes of Bologna criteria poor responders undergoing dual stimulation (DuoStim) and subsequent cryopreserved embryo transfer?Design
Case series of patients treated during the period August 2015 to March 2018 in a public fertility clinic. The study included 54 Bologna criteria poor responder IVF patients younger than 42 years receiving a follicular stimulation (DuoStim 1) followed by a luteal phase stimulation (DuoStim 2) within the same cycle, both stimulations being performed with corifollitropin alfa followed by a subsequent cryopreserved embryo transfer cycle. The primary endpoint was the number of oocytes retrieved in DuoStim 1 compared with DuoStim 2. The secondary endpoint was ongoing pregnancy rate (OPR) at 12 weeks of gestation.Results
The mean number of oocytes retrieved in DuoStim 1 and DuoStim 2 was 2.4 ± 2.1 versus 3.7 ± 2.6, respectively; thus, a total of 1.2 (95% CI, 0.46–1.96) more oocytes was retrieved in DuoStim 2 compared with DuoStim 1 (P = 0.002). The OPR at 12 weeks was 20% (11/54) in this poor ovarian response population with a mean age of 36.7 years.Conclusions
Luteal phase stimulation results in more oocytes in poor responders compared with follicular phase stimulation. DuoStim, using corifollitropin alfa followed by individualized FSH dosing, appears to be an alternative to conventional follicular phase stimulation, decreasing the risk of cycle cancellation. 相似文献52.
53.
Michael Helle David G. Norris Susanne Rüfer Karsten Alfke Olav Jansen Matthias J. P. van Osch 《Magnetic resonance in medicine》2010,64(3):777-786
A new technique for the imaging of flow territories of individual extra‐ and intracranial arteries is presented. The method is based on balanced pseudocontinuous arterial spin labeling but employs additional time‐varying gradients in between the radiofrequency pulses of the long labeling train. The direction of the additional gradient vector is perpendicular to the selected artery and its azimuthal angle is switched after every radiofrequency pulse. The phases of the radiofrequency pulses are adopted to cancel out the phase accrual of the spins at the center of the target vessel due to the extra applied gradients. This results in efficient inversion at the targeted position, whereas elsewhere time‐varying phase changes will result in marginal inversion efficiency. By changing the moment of the added gradients, the size of the labeling focus can be adjusted. Influence of the temporal order of the additional gradients on the labeling efficiency and on the selectivity was investigated by simulations and experimental measurements. In a volunteer study, the acquisition of high signal‐to‐noise ratio flow territory images of small branches of the anterior cerebral artery distal to the circle of Willis was demonstrated. This shows the method's flexibility for dealing with complicated arterial geometries and its ability to superselectively label small intracranial arteries. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
54.
Dag Hofsø Trond Jenssen Helle Hager Jo Røislien Jøran Hjelmesæth 《Obesity surgery》2010,20(3):302-307
Background
Higher mortality rates among morbidly obese (BMI of ≥40 or ≥35 kg/m2 with weight-related comorbidities) subjects are mainly explained by comorbidities such as type 2 diabetes. As bariatric surgery ameliorates diabetes, obese diabetic subjects will receive great benefits from bariatric surgery. Screening for diabetes prior to surgical referral is therefore crucial. 相似文献55.
Danish nationwide surveillance data on invasive pneumococcal disease from the 5-year period from 1995 to 1999, including 5,452 isolates, are presented and described. Annual overall incidence rates, serotype distribution, and antimicrobial susceptibility patterns of the isolates were monitored. Major changes in the total annual incidence rate from 27/100,000 in 1996 to 17/100,000 in 1999 and a significant change in the proportion of invasive isolates belonging to types 1 and 12F were observed. The serotype coverage rate by the 23-valent polysaccharide vaccine among the elderly was 92.9%, and the serotype coverage rate by the 7-, 9-, and 11-valent pneumococcal conjugate vaccines among children less than 2 years old were 71.7, 75.2, and 81.4%, respectively. Invasive isolates with reduced susceptibility to penicillin or erythromycin increased from 1995 to 1999, with a high proportion of the penicillin-nonsusceptible invasive isolates originating from people 60 years old or older (57.0%). These observations underline the importance of adequate surveillance systems of invasive pneumococcal disease to introduce and maintain national vaccine strategies and adequate antibiotic policy. 相似文献
56.
Ditte Ejegod Fabio Bottari Helle Pedersen Maria Teresa Sandri Jesper Bonde 《Journal of clinical microbiology》2016,54(9):2267-2272
This study describes a validation of the BD Onclarity HPV (Onclarity) assay using the international guidelines for HPV test requirements for cervical cancer screening of women 30 years old and older using Danish SurePath screening samples. The clinical specificity (0.90, 95% confidence interval [CI] = 0.88 to 0.91) and sensitivity (0.97, 95% CI = 0.87 to 1.0) of the Onclarity assay were shown to be not inferior to the reference assay (specificity, 0.90 [95% CI = 0.88 to 0.92]; sensitivity, 0.98 [95% CI = 0.91 to 1.0]). The intralaboratory reproducibility of Onclarity was 97%, with a lower confidence bound of 96% (kappa value, 0.93). The interlaboratory agreement was 97%, with a lower confidence bound of 95% (kappa value, 0.92). The BD Onclarity HPV assay fulfills all the international guidelines for a new HPV test to be used in primarily screening. This is the first clinical validation of a new HPV assay using SurePath screening samples, and thus the Onclarity HPV assay is the first HPV assay to hold an international validation for both SurePath and ThinPrep. 相似文献
57.
Usefulness of high-resolution comparative genomic hybridization (CGH) for detecting and characterizing constitutional chromosome abnormalities 总被引:6,自引:0,他引:6
Comparative genomic hybridization (CGH) is a technique for detection of chromosomal imbalances in a genomic DNA sample. We here report the application of the recently developed method of high-resolution CGH on DNA samples from 66 children having various degrees of delayed psychomotor development with or without clear dysmorphic features and congenital malformations. In 5 of 50 patients with apparently normal karyotypes, a deletion or duplication was revealed by CGH. Only one of these cases had a subtelomeric rearrangement. In one of seven cases with a de novo apparently balanced translocation, deletions were found. In all nine cases where the origin of a marker chromosome or additional chromosomal material was difficult to determine, CGH gave a precise identification. The following findings were from cases having a deletion or duplication as the sole chromosomal imbalance; dup(2)(p16p21), del(4)(q21q21), del(6)(q14q15), del(6)(p12p12), dup(6)(q24qter), and dup(15)(q11q13). One case had dup(9)(p11pter) combined with a very small subtelomeric deletion on 6q. In our hands, CGH is highly useful not only for identifying known chromosomal imbalances, but also for finding elusive deletions or duplications in the large group of children with developmental delay with or without congenital abnormalities. In such cases, the diagnostic yield of CGH appears to be higher than what has been reported from subtelomeric FISH screening. 相似文献
58.
Novel mouse model of chronic Pseudomonas aeruginosa lung infection mimicking cystic fibrosis 下载免费PDF全文
Hoffmann N Rasmussen TB Jensen PØ Stub C Hentzer M Molin S Ciofu O Givskov M Johansen HK Høiby N 《Infection and immunity》2005,73(4):2504-2514
Pseudomonas aeruginosa causes a chronic infection in the lungs of cystic fibrosis (CF) patients by establishing an alginate-containing biofilm. The infection has been studied in several animal models; however, most of the models required artificial embedding of the bacteria. We present here a new pulmonary mouse model without artificial embedding. The model is based on a stable mucoid CF sputum isolate (NH57388A) with hyperproduction of alginate due to a deletion in mucA and functional N-acylhomoserine lactone (AHL)-based quorum-sensing systems. Chronic lung infection could be established in both CF mice (Cftr(tmlUnc-/-)) and BALB/c mice, as reflected by the detection of a high number of P. aeruginosa organisms in the lung homogenates at 7 days postinfection and alginate biofilms, surrounded by polymorphonuclear leukocytes in the alveoli. In comparison, both an AHL-producing nonmucoid revertant (NH57388C) from the mucoid isolate (NH57388A) and a nonmucoid isolate (NH57388B) deficient in AHL were almost cleared from the lungs of the mice. This model, in which P. aeruginosa is protected against the defense system of the lung by alginate, is similar to the clinical situation. Therefore, the mouse model provides an improved method for evaluating the interaction between mucoid P. aeruginosa, the host, and antibacterial therapy. 相似文献
59.
Development of a quantitative real-time PCR assay for detection of Mycoplasma genitalium 总被引:1,自引:0,他引:1
Svenstrup HF Jensen JS Björnelius E Lidbrink P Birkelund S Christiansen G 《Journal of clinical microbiology》2005,43(7):3121-3128
Mycoplasma genitalium is known to cause nonchlamydial, nongonococcal urethritis in men and to be associated with pelvic inflammatory disease in women. Specific and sensitive PCR methods are needed for diagnosis of this bacterium because it is very difficult to culture from patient samples. To determine the bacterial load in patients' specimens, a quantitative real-time LightCycler PCR was developed. The housekeeping gene gap encoding glyceraldehyde-3-phosphate dehydrogenase was chosen as the target gene. The assay could consistently detect five genome copies per reaction. To evaluate the PCR, we tested 246 selected urethral swab samples from men attending a clinic for sexually transmitted diseases. Eighty-two of the samples were found positive for M. genitalium by a conventional 16S rRNA gene PCR assay, whereas 164 samples were randomly chosen among those tested negative. Of the positive samples, 78 (95.1%) were found positive, whereas 6 (3.7%) of the negatives were found positive by the LightCycler assay. The patient samples were also tested with a quantitative TaqMan assay, and the bacterial load was compared to the LightCycler results. A good linear correlation between the LightCycler and the TaqMan assays was found with a correlation coefficient of 0.89 and a slope of 0.99. Significantly more M. genitalium-positive men had urethritis, discharge, and dysuria than had M. genitalium-negative men. The M. genitalium DNA load in samples from patients with urethritis was significantly higher than in samples from those without (61 and 2.9 copies/microl, respectively [P = 0.0005]). This assay may prove useful in the monitoring of treatment and for optimizing sample preparation methods. 相似文献
60.
Comparison of two urinary antigen tests for establishment of pneumococcal etiology of adult community-acquired pneumonia 总被引:4,自引:0,他引:4 下载免费PDF全文
Strålin K Kaltoft MS Konradsen HB Olcén P Holmberg H 《Journal of clinical microbiology》2004,42(8):3620-3625
The Binax NOW immunochromatographic test (ICT) detecting the pneumococcal C polysaccharide and a serotype-specific latex agglutination (LA) test detecting 23 pneumococcal capsular antigens were evaluated for establishing pneumococcal etiology in community-acquired pneumonia (CAP) by use of nonconcentrated urine. ICT was considered to be strongly positive for result lines at least as intense as the control line and weakly positive for less intense result lines. When 215 adult CAP patients were tested, strong ICT, weak ICT, and LA positivity were found in 28, 24, and 16 patients, respectively; of these patients, 13 (46%), 6 (25%), and 13 (81%), respectively, had pneumococcal bacteremia and 27 (96%), 17 (71%), and 15 (94%), respectively, had Streptococcus pneumoniae isolated from blood, sputum, and/or nasopharynx. Among 108 controls tested, 2 (1.9%) were weakly ICT positive. When weak positivity was considered negative, the sensitivity of ICT decreased from 79% (19 of 24) to 54% (13 of 24), while the specificity increased from 83% (158 of 191) to 92% (176 of 191); no controls were false positive. The sensitivity and specificity of LA were 54% (13 of 24) and 98% (188 of 191), respectively. Eight of nine LA serotypes corresponded to culture serotypes. In conclusion, using nonconcentrated urine and dividing ICT-positive results into strongly and weakly positive results is a suitable way of performing ICT. While weak ICT positivity should be interpreted with caution, strong ICT positivity and LA positivity should be considered supportive of pneumococcal etiology in adult CAP. As such, these assays might have implications for antibiotic use in CAP. LA has promising potential for pneumococcal serotyping, although further evaluation is required. 相似文献