全文获取类型
收费全文 | 2858篇 |
免费 | 165篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 142篇 |
妇产科学 | 42篇 |
基础医学 | 325篇 |
口腔科学 | 23篇 |
临床医学 | 206篇 |
内科学 | 490篇 |
皮肤病学 | 28篇 |
神经病学 | 477篇 |
特种医学 | 208篇 |
外科学 | 307篇 |
综合类 | 53篇 |
一般理论 | 3篇 |
预防医学 | 292篇 |
眼科学 | 239篇 |
药学 | 97篇 |
中国医学 | 1篇 |
肿瘤学 | 81篇 |
出版年
2021年 | 27篇 |
2019年 | 39篇 |
2018年 | 36篇 |
2017年 | 37篇 |
2016年 | 59篇 |
2015年 | 37篇 |
2014年 | 64篇 |
2013年 | 90篇 |
2012年 | 140篇 |
2011年 | 134篇 |
2010年 | 71篇 |
2009年 | 57篇 |
2008年 | 116篇 |
2007年 | 105篇 |
2006年 | 106篇 |
2005年 | 134篇 |
2004年 | 124篇 |
2003年 | 102篇 |
2002年 | 102篇 |
2001年 | 93篇 |
2000年 | 106篇 |
1999年 | 83篇 |
1998年 | 31篇 |
1997年 | 36篇 |
1995年 | 27篇 |
1994年 | 19篇 |
1993年 | 19篇 |
1992年 | 61篇 |
1991年 | 60篇 |
1990年 | 59篇 |
1989年 | 62篇 |
1988年 | 58篇 |
1987年 | 55篇 |
1986年 | 50篇 |
1985年 | 53篇 |
1984年 | 41篇 |
1983年 | 30篇 |
1982年 | 34篇 |
1981年 | 18篇 |
1979年 | 43篇 |
1978年 | 28篇 |
1977年 | 28篇 |
1975年 | 24篇 |
1974年 | 27篇 |
1973年 | 32篇 |
1971年 | 21篇 |
1970年 | 23篇 |
1969年 | 22篇 |
1968年 | 26篇 |
1967年 | 19篇 |
排序方式: 共有3033条查询结果,搜索用时 15 毫秒
41.
Predictive value of sperm chromatin condensation (aniline blue staining) in the assessment of male fertility 总被引:7,自引:0,他引:7
Hammadeh ME Zeginiadov T Rosenbaum P Georg T Schmidt W Strehler E 《Archives of andrology》2001,46(2):99-104
A case control study was carried out to determine the value of sperm chromatin condensation in the assessment of male fertility. A total of 165 semen samples from 90 patients (cases) and 75 healthy donors (control) were examined for chromatin condensation (aniline blue staining), as well as conventional sperm parameters, notably sperm morphology, sperm count, and progressive motility. Whereas only 55 +/- 12.0% of the samples from the infertile patients were unstained by aniline blue (chromatin condensed), 78 +/- 19.0% of the samples in the control group did not take up the stain (chromatin condensed). A significant difference (p < .001) was observed between the two groups. Similarly, the difference between the mean percentage of morphologically normal spermatozoa for the infertile patients (12.1 +/- 1.2%) and the control (23.9 +/- 1.9%) was very significant (p < .001). In addition, only 50 out of the 90 patients (55.5%) had a normal sperm count, whereas all the 75 (100%) were normal in the control group. By comparing between the two groups a significant difference (p < .001) was also observed. Furthermore, a significant difference (p < .001) was also found between the cases and the control with regard to the percentage of spermatozoa illustrating linear progressive motility (40 +/- 9.7% vs. 70 +/- 12.3%). However, no correlation was found between sperm chromatin condensation and morphology, count, and motility. This study suggests that chromatin condensation constitutes a valuable parameter in the assessment of male fertility, completely independent of conventional sperm parameters. Consequently, the inclusion of chromatin condensation to routine laboratory investigations of semen prior to assisted reproduction is strongly recommended. 相似文献
42.
Hammadeh ME Dehn C Hippach M Zeginiadou T Stieber M Georg T Rosenbaum P Schmidt W 《International journal of andrology》2001,24(2):66-72
The purpose of this study was to determine the negative effects (cryodamage) on human spermatozoa after freeze-thawing and to determine whether freeze-thawing of spermatozoa with a programmed slow freezer is better than freezing with liquid nitrogen vapour (rapid freezing) with regard to alterations in sperm chromatin and morphology in semen from fertile (donor) and subfertile, IVF/ICSI, patients. Ninety-five semen samples were obtained either from patients attending our IVF unit for treatment (n=34) or from donors (n=25) with proven fertility and normal sperm quality according to WHO guidelines. Each semen sample was divided into two parts after liquefaction and addition of the cryoprotectant. The first part was frozen using a programmed biological freezer and the second part was frozen by means of liquid nitrogen vapour. Smears were made before the freezing and after the thawing procedure to assess morphology (strict criteria) and chromatin condensation (Acridine Orange test). The mean percentage of chromatin condensed spermatozoa in the samples from donors (control group) was 92.4 +/- 8.4% before freezing and this decreased significantly (p < 0.0001) to 88.7 +/- 11.2% after freeze-thawing with the computerized slow-stage freezer and to 87.2 +/- 12.3% after using static liquid nitrogen vapour (p < 0.001). The corresponding values for semen obtained from patients was 78.9 +/- 10.3% before freezing which decreased to 70.7 +/- 10.8 and 68.5 +/- 14.8%, respectively (p < 0.001). On the other hand, the mean percentage of normal sperm morphology in the control group decreased from 26.3 +/- 7.5% before freezing to 22.1 +/- 6.4% (p < 0.0001) after thawing with the computerized slow-stage freezer and to 22.2 +/- 6.6% (p < 0.0001) after the use of static liquid nitrogen vapour. In the patient group, the mean percentage of normal morphology decreased from 11.7 +/- 6.1% after freezing with the biological freezer to 9.3 +/- 5.6% and to 8.0 +/- 4.9% after freezing with static liquid nitrogen vapour. This study demonstrates that chromatin packaging and morphology of human spermatozoa decrease significantly after the freeze-thawing procedure, not only after the use of static liquid nitrogen vapour but also after the use of a computerized slow-stage freezer. However, the chromatin of semen samples with normal semen parameters (donor sperm) withstand the freeze-thaw injury better than those with low quality semen samples. Therefore, the computerized slow stage freezer could be recommended for freezing of human spermatozoa, especially for subnormal semen samples, for example, ICSI and ICSI/TESE candidates and from patients with testicular tumours or Hodgkin's disease, in order to avoid further damage to the sperm chromatin structure. 相似文献
43.
Aeromonas hydrophila septicemia complicated by a generalized cutaneous vasculitis developed in a patient receiving home hemodialysis therapy. Because the Aeromonas organism is found in many natural water sources, the possibility that this patient's hemodialysis system became contaminated was explored. Although cultures from the patient's home environment showed no Aeromonas sp, the possibility still exists that the site of contamination was in the dialysis system. 相似文献
44.
45.
Rosenbaum GE Burns J Johnson J Mitchell C Robinson M Truog RD 《Archives of internal medicine》2000,160(3):374-380
BACKGROUND: Autopsy rates continue to fall despite the enduring benefit of the procedure to families and medical science, yet there are few data about the consent process itself. OBJECTIVE: To evaluate the current practice of obtaining autopsy consent, by assessing the consent forms currently in use, the knowledge and attitudes of chief residents on the procedure, and the expert opinion of pathologists in those institutions. DESIGN: Cross-sectional survey. SETTINGS AND PARTICIPANTS: One hundred twenty-seven US teaching hospitals. RESULTS: Of all autopsy consent forms we surveyed, 84.7% contained 7 of 10 elements recommended by the College of American Pathologists. Only 7.1% of institutions supplied educational materials for the physician, as recommended by the College of American Pathologists. Overall, 50.1% of chief residents reported deficiencies in their knowledge of the autopsy procedure. Correspondingly, greater than 74.5% felt that educational materials would be beneficial for physicians and the family. Finally, 93.3% of chief residents believed that a limited autopsy should be offered to families, while 68 (90%) of 76 pathologists at these institutions believed that limited autopsies are an unsatisfactory alternative to the complete procedure. CONCLUSIONS: Chief residents at US teaching hospitals reported substantial deficiencies in their knowledge about autopsy and desire more training on the consent process. Autopsy consent forms are often lacking information that might help physicians and families in making an educated choice about autopsy. Teaching institutions need to reevaluate the training for the autopsy consent practice. 相似文献
46.
47.
Arasi Thangavelu Steven Rosenbaum Devi Thangavelu 《The Journal of emergency medicine》2018,54(6):892-897
Background
Cholecystitis is an inflammation of the gallbladder that most commonly occurs as a result of obstruction of the cystic duct by gallstones. The current standard of treatment for acute cholecystitis is cholecystectomy.Objective
Our goal was to discuss the benefits of and compare early laparoscopic cholecystectomy and delayed laparoscopic cholecystectomy in the treatment of acute cholecystitis.Materials and Methods
A Medline literature search was performed dating from January 1982 to July 2015. We limited the search to human studies written in English and using the keywords “Acute Cholecystitis,” early vs. delayed laparoscopic cholecystectomy, surgical management, and surgical complications.Results
There were 225 articles reviewed, of which 25 met criteria for selection. Our recommendations are based on these 25 articles.Conclusion
Early laparoscopic cholecystectomy is preferred over delayed, due to overall better quality of life, lower morbidity rates, and lower hospital cost. Ultimately, management of acute cholecystitis by emergency physicians should be made based on patient's clinical status and available resources in their particular hospital. 相似文献48.
Gaucher disease, the inherited deficiency of the lysosomal enzyme glucocerebrosidase, manifests with a continually expanding range of clinical features. Noting that a number of adult patients with type 1 Gaucher disease also had gallstones, we reviewed the clinical records of 66 adult patients evaluated at the National Institutes of Health with type 1 Gaucher disease. Twenty-one patients were identified who had either gallstones or a history of cholecystectomy. Of the 21 patients, 6 were male. The age at which stones were noted ranged from 19 to 70 years (mean 39 years). Thirteen of the patients had a cholecystectomy performed. Several different factors may contribute to the development of gallstones in these patients, including anemia, prior splenectomy, and hepatic involvement. Eleven of the patients were found to have chronic anemia. Fifteen of the patients underwent splenectomy. An increased biliary excretion of glucosylceramide could also contribute to cholelithiasis. To determine whether our findings were specific to our referral population, the medical records of a second series of 80 adult patients of Ashkenazi Jewish ancestry with type 1 Gaucher disease followed in Northern Israel were reviewed. Sixteen of these patients (5 male, 11 female) were also noted to have gallstones. Thus, the frequency of gallbladder involvement in patients with Gaucher disease appears to be greater than previously appreciated. 相似文献
49.
50.