全文获取类型
收费全文 | 3155篇 |
免费 | 173篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 351篇 |
妇产科学 | 37篇 |
基础医学 | 292篇 |
口腔科学 | 278篇 |
临床医学 | 201篇 |
内科学 | 219篇 |
皮肤病学 | 5篇 |
神经病学 | 112篇 |
特种医学 | 131篇 |
外科学 | 548篇 |
综合类 | 375篇 |
预防医学 | 344篇 |
眼科学 | 87篇 |
药学 | 166篇 |
2篇 | |
中国医学 | 101篇 |
肿瘤学 | 107篇 |
出版年
2024年 | 6篇 |
2023年 | 52篇 |
2022年 | 68篇 |
2021年 | 133篇 |
2020年 | 109篇 |
2019年 | 114篇 |
2018年 | 111篇 |
2017年 | 98篇 |
2016年 | 85篇 |
2015年 | 100篇 |
2014年 | 169篇 |
2013年 | 236篇 |
2012年 | 165篇 |
2011年 | 187篇 |
2010年 | 159篇 |
2009年 | 144篇 |
2008年 | 139篇 |
2007年 | 130篇 |
2006年 | 127篇 |
2005年 | 83篇 |
2004年 | 103篇 |
2003年 | 107篇 |
2002年 | 80篇 |
2001年 | 53篇 |
2000年 | 67篇 |
1999年 | 66篇 |
1998年 | 42篇 |
1997年 | 38篇 |
1996年 | 40篇 |
1995年 | 39篇 |
1994年 | 44篇 |
1993年 | 37篇 |
1992年 | 27篇 |
1991年 | 20篇 |
1990年 | 26篇 |
1989年 | 15篇 |
1988年 | 27篇 |
1987年 | 27篇 |
1986年 | 21篇 |
1985年 | 10篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1977年 | 4篇 |
1975年 | 6篇 |
1973年 | 7篇 |
1972年 | 3篇 |
排序方式: 共有3366条查询结果,搜索用时 109 毫秒
31.
Disc replacement using Pro-Disc C versus fusion: a prospective randomised and controlled radiographic and clinical study 总被引:4,自引:0,他引:4
A. Nabhan F. Ahlhelm T. Pitzen W. I. Steudel J. Jung K. Shariat O. Steimer F. Bachelier D. Pape 《European spine journal》2007,16(3):423-430
Anterior cervical discectomy and fusion (ACDF) may be considered to be the gold standard for treatment of symptomatic degenerative
disc disease within the cervical spine. However, fusion of the segment may result in progressive degeneration of the adjacent
segments. Therefore, dynamic stabilization procedures have been introduced. Among these, artificial disc replacement by disc
prosthesis seems to be promising. However, to be so, segmental motion must be preserved. This, again, is very difficult to
judge and has not yet been proven. The aim of the current study was to first analyse the segmental motion following artificial
disc replacement using a disc prosthesis. A second aim was to compare both segmental motion as well as clinical result to
the current gold standard (ACDF). This is a prospective controlled study. Twenty-five patients with cervical disc herniation
were enrolled and assigned to either study group (receiving a disc prosthesis) or control group (receiving ACDF, using a cage
with bone graft and an anterior plate.) Radiostereometric analysis was used to quantify intervertebral motion immediately
as well as 3, 6, 12 and 24 weeks postoperatively. Further, clinical results were judged using visual analogue scale and neuro-examination.
Cervical spine segmental motion decreased over time in the presence of disc prosthesis or ACDF. However, the loss of segmental
motion is significantly higher in the ACDF group, when looked at 3, 6, 12 and 24 weeks after surgery. We observed significant
pain reduction in neck and arm postoperatively, without significant difference between both groups (P > 0.05). Cervical spine disc prosthesis preserves cervical spine segmental motion within the first 6 months after surgery.
The clinical results are the same when compared to the early results following ACDF. 相似文献
32.
M. J. Baurain M.D. B. S. Dernovoi A. A. D'Hollander D. A. Hennart F. R. Cantraine 《Acta anaesthesiologica Scandinavica》1996,40(5):574-578
Background: Since neostigmine was introduced for reversal of neuromuscular block, there has been controversy about the optimum dose for antagonizing neuromuscular block. The purpose of this study was to characterise recovery of neuromuscular transmission following a vecuronium-induced block 15 min after neostigmine administration using different stimulation patterns, and to determine the effects of different doses of neostigmine given at various pre-reversal twitch heights. Methods: Adductor pollicis (AP) mechanical activity in response to low (0.1 and 2 Hz) and high (50 and 100 Hz) frequency stimulation, was recorded 15 min after 20, 40 and 80 μg/kg neostigmine, given to reverse a vecuronium-induced block at 10, 25 and 50% pre-reversal twitch height (TH). Fifty four ASA class I and II anaesthetised (methohexital, fentanyl, N2O/O2) young adult patients were studied and randomly allocated into 9 groups of 6 patients each. Results: In contrast to twitch height (TH) and residual force after 50 Hz, 5 s tetanic stimulation (RF50Hz), the greater sensitivity of train-of-four (TOF) ratio and residual force after 100 Hz, 5 s tetanic stimulation (RF100Hz) points out the best reversal conditions (prereversal TH and the optimal neostigmine dose) (P<0.001, two-way analysis of variance). The highest reversal scores (about 0.9 TOF ratio and RF100Hz) were obtained when 40 μg/ kg of neostigmine was given at 25 and 50% TH. A 0.9 TOF ratio was also observed when 40 μg/kg of neostigmine was given at 10% TH, but, under these conditions, RF100Hz was only 0.6 (P<0.05, Duncan test). Conclusion: To optimise the reversal action of neostigmine in order to obtain the highest neuromuscular transmission recovery (0.9 TOF ratio and RF100Hz) during a vecuronium-induced neuromuscular block, the 40 μg/kg dose has to be given at 25 to 50% recovery of TH. 相似文献
33.
Motor evoked potentials (MEPs) obtained by electrical root stimulation and F waves were used to examine the proximal nerve conduction velocity (CV) to tibialis anterior (TA), extensor digitorum brevis (EDB), flexor carpi radialis (FCR), and abductor pollicis brevis (APB) muscles in 40 humans. By subtracting motor latencies obtained by stimulating the peripheral nerve at the same point from the F-wave and MEP latencies, we could measure the CV over identical proximal segments. It was found that proximal CV to TA and FCR was significantly higher than to EDB and APB, respectively. Combining the data of the proximal CV to all four muscles in relation with axonal length resulted in a highly significant inverse relationship (r2 = 0.77). Thus the axonal length explained to a large extent the higher CV of the arm nerves and also the inverse relation between body height and CV. The distal CV was always lower than proximal CV; however, there was no support for an additional effect of this gradient in explaining the relationship between CV and height since it was constant for all body heights. © John Wiley & Sons, Inc. 相似文献
34.
Bavo Vanden Eynde Dirk Vienne Magda Vuylsteke-Wauters Dirk Van Gerven 《European journal of applied physiology》1988,57(4):430-434
Summary To determine the cardiorespiratory response to maximal exercise before, during and after the pubescent growth spurt, thirty boys were tested at yearly intervals over a period of six consecutive years. For each individual, peak height velocity (PHV) was determined. The age at PHV (¯X= 13.6 years) was taken as a standard of maturation. The results from all subjects at 1.5 and 0.5 years before and 0.5 and 1.5 years after PHV are presented. The highest oxygen uptake (
) obtained during an incremental bicycle ergometer test to voluntary exhaustion was taken as peak oxygen uptake (
peak). Across each of the four years studied, mean
peak (min=49.6; max=52.5 ml·kg–1·min–1) and mean heart rate (HR) at
peak (min=190; max=192) did not change significantly as a function of PHV. On the other hand, the respiratory quotient at
peak increased considerably from mean minima and maxima of 0.99 and 1.01 before PHV to 1.07 and 1.10 after PHV. Ventilatory equivalent for
(
), taken as an indicator of ventilatory economy, seemed to be unaffected by the maturation process. The steepest increase in circumpubertal oxygen pulse was found one year after PHV. Average stability coefficients (¯r), calculated from the inter-years correlations were high for height (¯r=0.95), weight (¯r=0.92), HR at
peak (¯r=0.74),
peak in 1/min (¯r=0.71), oxygen pulse (¯r=0.68) and tidal volume (¯r=0.64). 相似文献
35.
Leslie C. Grammer Loui Silvestri Irena M. Suszko Martha A. Shaughnessy Roy Patterson 《The Journal of allergy and clinical immunology》1983,72(2):160-167
The standardization procedures for polymerized ragweed (PRW) must evaluate activity of PRW with assessments that differ from those used for standard unmodified extracts. This is because PRW allergens are different from conventional ragweed extracts in that they are much greater in average molecular weight and much lower in allergenicity for equivalent immunogenicity. We have evaluated seven samples of PRW for three parameters: allergenicity as determined by cutaneous end point titration, molecular weight distribution as determined by Sephadex G-200 chromatography, and availability of antigen E (AgE) determinants as measured by the ability of an extract to inhibit AgE binding to antibody by using a modification of the Farr technique. The skin test titers and molecular weight profiles provide information as to the safety of a PRW preparation and antigen-binding inhibitory activity gives information about allergenicity and immunogenicity. Appropriate limits may be set for each of these parameters to standardize PRW for clinical use. 相似文献
36.
Slobodan Jarić Dušan Ristanović Daniel M. Corcos 《European journal of applied physiology》1989,59(5):370-376
Summary Kinematic variables of the vertical jump (jumping height, jump phase durations and joint angles) were measured on 39 male
physical education students. In addition, kinetic parameters of the hip and knee extensors, and of the plantar flexors (maxima
voluntary force and its rate of development) were recorded on the same subjects, in isometric conditions. The results demonstrated
significant positive correlations between kinetic parameters of the active muscle groups and jumping height (r=0.217−0.464). The dominant effect on these correlations was due to the knee extensors. Correlations between these parameters
and the duration of the jump phases were much weaker. Correlation coefficients between kinetic parameters and limb angles
in the lowest body position showed that fast force production in one muscle group was related to a significant decrease in
the joint angles of distant body segments. Multiple correlation coefficients between leg extensor parameters and kinematic
variables (ranging between 0.256 for the duration of the counter-movement phase and 0.616 for jump height) suggested that
kinetic parameters could explain more than a quarter of the variability of this complex human movement. Therefore, the conclusion
was drawn that an extended set of measurements of the relevant musculo-skeletal system parameters could predict a considerable
amount of the variability of human movement. However, high correlation coefficients between the same kinetic parameters of
different muscle groups suggest that not all active muscle groups have to be included in the measurements. 相似文献
37.
Ilhan Kaya Nazife Yigit Mehlika Benli 《African journal of traditional, complementary, and alternative medicines》2008,5(4):363-369
The antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of Ocimum basilicum L. were studied. These extracts were tested in vitro against 10 bacteria and 4 yeasts strains by the disc diffusion method. The results indicated that the methanol extracts of O. basilucum exhibited the antimicrobial activity against tested microorganisms. While the chloroform and acetone extracts had no effect, the methanol extracts showed inhibition zones against strains of Pseudomonas aeruginosa, Shigella sp., Listeria monocytogenes, Staphylococcus aureus and two different strains of Escherichia coli. The cells of microorganisms, which were treated and untreated with plant extracts, were observed by using the scanning electron microscope. It was observed that the treated cells were damaged. 相似文献
38.
39.
María-Jos de Castro Paula Snchez-Pintos Nisreem Abdelaziz-Salem Rosaura Leis María L. Couce 《Nutrients》2021,13(6)
Children with inborn errors of intermediary metabolism (IEiM) must follow special diets that restrict their intake of essential nutrients and may compromise normal growth and development. We evaluated body composition, bone mineral density, physical activity, and food intake in IEiM patients undergoing dietary treatment. IEiM patients (n = 99) aged 5–19 years and healthy age- and sex-matched controls (n = 98) were recruited and underwent dual-energy X-ray absorptiometry to evaluate anthropometric characteristics and body composition. Data on food intake and physical activity were also collected using validated questionnaires. The height z-score was significantly lower in IEiM patients than controls (−0.28 vs. 0.15; p = 0.008), particularly in those with carbohydrate and amino acid metabolism disorders. Significant differences in adiposity were observed between patients and controls for the waist circumference z-score (−0.08 vs. −0.58; p = 0.005), but not the body mass index z-score (0.56 vs. 0.42; p = 0.279). IEiM patients had a significantly lower total bone mineral density (BMD) than controls (0.89 vs. 1.6; p = 0.001) and a higher risk of osteopenia (z-score < −2, 33.3% vs. 20.4%) and osteoporosis (z-score < −2.5, 7.1% vs. 0%), but none presented fractures. There was a significant positive correlation between natural protein intake and BMD. Our results indicate that patients with IEiM undergoing dietary treatment, especially those with amino acid and carbohydrate metabolism disorders, present alterations in body composition, including a reduced height, a tendency towards overweight and obesity, and a reduced BMD. 相似文献
40.
目的 分析父母身高对7岁以下儿童身高的影响效应,为个体儿童生长评估提供参考依据。方法 以“2015年中国九市7岁以下儿童体格发育调查”中父母身高信息完整的161 297名儿童为分析对象,参照中国儿童身高标准计算儿童身高、父亲身高、母亲身高和父母身高中值的Z分值,采用Spearman方法分析儿童身高与父身高、母身高、父母身高中值的相关性,并按父母身高分组,比较各组儿童身高的差异。 结果 1)儿童身高与父身高、母身高和父母身高中值正相关(r=0.13~0.42,P<0.05),且与父母身高中值的相关系数最高;2)按父母身高中值分为矮身材、偏矮、中等偏下、中等偏上、较高、高身材6组,各组儿童平均身高依次递增,父母矮身材组儿童身高比父母高身材组低1.9~14.7 cm,年龄越大差值越大;3)父母身高偏矮组子女身高第3百分位(P3)比中国儿童身高标准P3低0.6~4.8 cm,而父母较高身材组P3则比身高标准P3高0.6~4.7 cm;4)父母矮身材、偏矮、中等偏下、中等偏上、较高和高身材组的儿童身高Z分值与父母身高中值Z分值差值依次为1.27±0.99、0.61±0.92、0.18±0.89、-0.19±0.90、-0.61±0.93、-1.17±0.92。结论 7岁以下儿童身高与父母身高正相关;矮身材父母的子女身高明显低于高身材父母子女;矮身材父母子女身高高于家庭遗传身高;个体儿童身高评估和解释时,不可忽视父母身高的影响作用。 相似文献