全文获取类型
收费全文 | 13071篇 |
免费 | 810篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 146篇 |
儿科学 | 416篇 |
妇产科学 | 386篇 |
基础医学 | 1587篇 |
口腔科学 | 332篇 |
临床医学 | 1961篇 |
内科学 | 2057篇 |
皮肤病学 | 186篇 |
神经病学 | 1217篇 |
特种医学 | 409篇 |
外科学 | 1345篇 |
综合类 | 131篇 |
一般理论 | 14篇 |
预防医学 | 1674篇 |
眼科学 | 181篇 |
药学 | 1075篇 |
中国医学 | 16篇 |
肿瘤学 | 808篇 |
出版年
2023年 | 58篇 |
2022年 | 88篇 |
2021年 | 202篇 |
2020年 | 120篇 |
2019年 | 211篇 |
2018年 | 253篇 |
2017年 | 182篇 |
2016年 | 188篇 |
2015年 | 235篇 |
2014年 | 356篇 |
2013年 | 531篇 |
2012年 | 746篇 |
2011年 | 839篇 |
2010年 | 493篇 |
2009年 | 370篇 |
2008年 | 722篇 |
2007年 | 797篇 |
2006年 | 783篇 |
2005年 | 714篇 |
2004年 | 668篇 |
2003年 | 682篇 |
2002年 | 704篇 |
2001年 | 319篇 |
2000年 | 337篇 |
1999年 | 253篇 |
1998年 | 153篇 |
1997年 | 139篇 |
1996年 | 98篇 |
1995年 | 104篇 |
1994年 | 95篇 |
1993年 | 82篇 |
1992年 | 183篇 |
1991年 | 173篇 |
1990年 | 169篇 |
1989年 | 148篇 |
1988年 | 154篇 |
1987年 | 152篇 |
1986年 | 131篇 |
1985年 | 139篇 |
1984年 | 95篇 |
1983年 | 84篇 |
1982年 | 68篇 |
1981年 | 72篇 |
1979年 | 90篇 |
1978年 | 75篇 |
1977年 | 64篇 |
1976年 | 66篇 |
1974年 | 58篇 |
1973年 | 64篇 |
1972年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Judy A Morris 《AAOHN journal》2008,56(5):207-14; quiz 215-6
Intermittent unscheduled absenteeism often challenges employers to meet the needs of their employees, control direct absenteeism costs, and maintain the staff needed to serve customers. Occupational health nurses have opportunities to play an important role in addressing this challenge. Measurable financial impacts have been demonstrated from integrating the management of intermittent FMLA leave with an employer's existing absence management program. 相似文献
992.
Judy C. Boughey MD Farzin Goravanchi DO Ronald N. Parris MD Spencer S. Kee MD John C. Frenzel MD Kelly K. Hunt MD Frederick C. Ames MD Henry M. Kuerer MD PhD Anthony Lucci MD 《The breast journal》2009,15(5):483-488
Abstract: Thoracic paravertebral block (PVB) in breast surgery can provide regional anesthesia during and after surgery with the potential advantage of decreasing postoperative pain. We report our institutional experience with PVB over the initial 8 months of use. All patients undergoing breast operations at the ambulatory care building from September 09, 2005 to June 28, 2005 were reviewed. Comparison was performed between patients receiving PVB and those who did not. Pain scores were assessed immediately, 4 hours, 8 hours and the morning after surgery. 178 patients received PVB and 135 patients did not. Patients were subdivided into three groups: Group A–segmental mastectomy only ( n = 89), Group B–segmental mastectomy and sentinel node surgery ( n = 111) and Group C–more extensive breast surgery ( n = 113). Immediately after surgery there was a statistically significant difference in the number of patients reporting pain between PVB patients and those without PVB. At all time points up until the morning after surgery PVB patients were significantly less likely to report pain than controls. Patients in Group C who received PVB were significantly less likely to require overnight stay. The average immediate pain scores were significantly lower in PVB patients than controls in both Group B and Group C and approached significance in Group A. PVB in breast surgical patients provided improved postoperative pain control. Pain relief was improved immediately postoperatively and this effect continued to the next day after surgery. PVB significantly decreased the proportion of patients that required overnight hospitalization after major breast operations and therefore may decrease cost associated with breast surgery. 相似文献
993.
T R Easterling K L Carlson B C Schmucker D A Brateng T J Benedetti 《American journal of perinatology》1990,7(3):220-222
Doppler technique of measuring cardiac output was evaluated during pregnancy. In a study of accuracy Doppler technique correlated well with thermodilution, (r = 0.95, y = 1.05x - 0.35). In a study of interoperator variability, the technique was found to be reproducible, (r = 0.92, y = 0.91x + 0.74). 相似文献
994.
995.
Soluble factor in normal tissues that stimulates high-molecular-weight sialoglycoprotein production by human colon carcinoma cells 总被引:2,自引:0,他引:2
T Irimura A M McIsaac D A Carlson M Yagita E A Grimm D G Menter D M Ota K R Clary 《Cancer research》1990,50(11):3331-3338
The stimulation of high molecular weight sialoglycoprotein synthesis by a soluble factor derived from normal colon tissues was studied in vitro with human colon carcinoma cell lines, HT-29 P and a metastatic variant HT-29 LMM. The synthesis of all three high-molecular-weight sialoglycoproteins (approximate Mr 900,000, 740,000, and 450,000) by HT-29 P cells or HT-29 LMM cells growing in vitro was enhanced by supplementing the culture medium with a conditioned medium of fresh human colon organ culture. Changes were detected by polyacrylamide gel electrophoresis of lysates from [3H]glucosamine-labeled cells on 3% gels followed by fluorography, or by electrophoresis of lysates from unlabeled cells followed by incubation with 125I-labeled wheat germ agglutinin and autoradiography. No changes were detected in the major protein components or in glycoproteins at Mr less than 200,000 as revealed by polyacrylamide gel electrophoresis. The treated cells did not change their growth rate or morphology. The connective tissue portions of the colon tissues were apparently responsible for the production of this stimulatory substance. The stimulatory activity was preserved at 56 degrees C but was inactivated by heating at 100 degrees C. The substance was eluted from a Sephacryl S-200 column at a position between the elution positions of ovalbumin and trypsinogen. The colon carcinoma cells treated with the conditioned medium and producing increased amounts of high-molecular-weight sialoglycoproteins were less sensitive to the cytolytic effects of recombinant interleukin 2-activated human peripheral blood lymphocytes than untreated cells were. The treated colon carcinoma cells induced stronger platelet aggregation than their untreated counterparts did. Therefore, this substance may represent one of the normal host tissue factors that can influence and modulate malignant behavior of carcinoma cells growing in vivo. 相似文献
996.
Improved metabolic control may delay or prevent the late complicationsof diabetes. In order to achieve this diabetes-care deliveryneeds to be made more effective. Diabetes-control programs havebeen developed to help translate knowledge into practice. Re-structuringsocial services has often been ineffective, partly because ofpoor involvement by members of an organization. The purposeof the present study was to test a method which would allowfor patient and health-care provider participation in the localplanning of diabetes care. The method consisted of a seriesof steps which allowed health-care providers and consumers toidentify and analyse problems and to suggest and where possible,implement solutions. The impact of this program was tested in17 primary health-care centres. We report here on problems identifiedby staff and consumers, plans for their solution, and the resultsafter 18 months. Many problems, mainly dealing with the organizationof diabetes care and a number of possible solutions to themwere identified. Other problem areas concerned staffpatient relationships and contacts with the external environment.After 18 months a majority (70%) of the solutions had been implemented. 相似文献
997.
Umesh M Hanumegowda Barbara M Judy Wade V Welshons Chada S Reddy 《Toxicological sciences》2002,66(1):159-165
Secalonic acid D (SAD), a teratogenic mycotoxin, induces cleft palate (CP) in the offspring of exposed mice by inhibiting palatal shelf growth. Since reduced proliferation, increased apoptosis, and/or decreased extracellular matrix (ECM) synthesis of palatal mesenchymal cells (PMC) can all contribute to smaller shelf size, the hypothesis that teratogenically relevant concentrations (0 to 120 microg/ml) of SAD will have adverse effects on one or more of these cellular processes was tested, using primary murine PMC cultures. Exposure to SAD resulted in significant and dose-dependent decreases in mesenchymal cell number, uptake of (3)H-thymidine, and expression of proliferating cell nuclear antigen (PCNA). Trypan blue dye exclusion assay, however, revealed significant cell death only at higher doses, suggesting that the decrease in cell number at lower (more realistic) doses is likely a consequence of reduced cell proliferation and not cell death. Further, negative results in the DNA fragmentation analysis following SAD exposure suggested that cell death caused by higher levels of SAD was unrelated to apoptosis. Similarly, results of (3)H-glucosamine uptake assay indicated inhibitory effect of SAD on accumulation of hyaluronic acid (HA) or sulfated glycosaminoglycans (sGAG) only at the highest dose tested. Also, SAD affected neither extracellular nor cell-associated fibronectin expression at any dose tested. Taken together, these data suggest that the pathogenesis of CP by SAD is likely a result of a reduction in the size of the palatal shelf caused by SAD-induced inhibition of mesenchymal cell proliferation. 相似文献
998.
This study compared the histochemical characteristics of the temporalis and masseter muscles in monkeys who underwent mandibular advancement with and without immobilization of the mandible. The results showed, when compared with controls, that the animals who underwent maxillomandibular fixation (MMF) following advancement of the mandible had significant atrophy in both temporalis and masseter muscles. In contrast, much less myoatrophy was noted in the animals who underwent rigid internal fixation and no MMF following advancement of the mandible. 相似文献
999.
Tumor necrosis factor (TNF) is induced in mice by Candida albicans: role of TNF in fibrinogen increase. 总被引:12,自引:7,他引:5 下载免费PDF全文
One intraperitoneal dose of Candida albicans (10(8) CFU) caused a chronic (longer than 2 months), significant elevation of plasma fibrinogen levels (Clauss method) in mice of strain C3H/HeN. Even a small dose (10(6) CFU) resulted in a significant increase in fibrinogen level for 5 days following injection, whereas other blood parameters (leukocytes, erythrocytes, platelets, hematocrit, hemoglobin, blood urea nitrogen, aspartate aminotransferase, albumin, alkaline phosphatase, antithrombin III, glucose, calcium, and total protein) measured by standard methods were normal. Blood taken during this period was negative for C. albicans. The role of tumor necrosis factor (TNF) in C. albicans infections was investigated by measuring the fibrinogen response after the administration of C. albicans or recombinant mouse TNF-alpha. Both challenges resulted in an elevated fibrinogen level. When polyclonal antibodies to mouse TNF-alpha were given prior to challenge with C. albicans or mouse TNF-alpha, the fibrinogen increase was significantly inhibited. C. albicans injections were found to significantly elevate endogenous TNF levels in mice (enzyme-linked immunosorbent assay). It was concluded that C. albicans induces TNF in the mouse. Furthermore, these data give evidence which supports a relationship between TNF and the fibrinogen increase induced by C. albicans. 相似文献
1000.
Rapid radiofrequency calibration in MRI 总被引:1,自引:0,他引:1