全文获取类型
收费全文 | 1750篇 |
免费 | 134篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 113篇 |
妇产科学 | 30篇 |
基础医学 | 151篇 |
口腔科学 | 77篇 |
临床医学 | 139篇 |
内科学 | 499篇 |
皮肤病学 | 52篇 |
神经病学 | 83篇 |
特种医学 | 166篇 |
外科学 | 282篇 |
综合类 | 49篇 |
预防医学 | 40篇 |
眼科学 | 88篇 |
药学 | 31篇 |
肿瘤学 | 72篇 |
出版年
2023年 | 5篇 |
2022年 | 12篇 |
2021年 | 22篇 |
2020年 | 13篇 |
2019年 | 17篇 |
2018年 | 32篇 |
2017年 | 19篇 |
2016年 | 47篇 |
2015年 | 42篇 |
2014年 | 65篇 |
2013年 | 86篇 |
2012年 | 93篇 |
2011年 | 80篇 |
2010年 | 85篇 |
2009年 | 86篇 |
2008年 | 104篇 |
2007年 | 150篇 |
2006年 | 94篇 |
2005年 | 94篇 |
2004年 | 75篇 |
2003年 | 59篇 |
2002年 | 54篇 |
2001年 | 43篇 |
2000年 | 27篇 |
1999年 | 30篇 |
1998年 | 45篇 |
1997年 | 46篇 |
1996年 | 51篇 |
1995年 | 39篇 |
1994年 | 26篇 |
1993年 | 30篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 25篇 |
1988年 | 18篇 |
1987年 | 20篇 |
1986年 | 19篇 |
1985年 | 16篇 |
1984年 | 10篇 |
1983年 | 15篇 |
1982年 | 6篇 |
1981年 | 18篇 |
1980年 | 12篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 3篇 |
1884年 | 1篇 |
排序方式: 共有1897条查询结果,搜索用时 15 毫秒
51.
Ether lipids (EL) and hyperthermia have been shown to possess a relatively selective cytotoxicity to leukemic cells. In this study, the combined effects of EL (ET-18-OCH3, ET-16-NHCOCH3, or BM 41.440) and hyperthermia on the growth of hematopoietic progenitors, myeloid leukemic cell lines, and leukemic cells obtained from patients with acute myeloid leukemia (AML) were examined to determine if this combination resulted in a greater selective killing of leukemic cells than that achieved by either EL or heat alone. When the cells were treated simultaneously with EL (50 micrograms/mL) and hyperthermia (42 degrees C) for one hour, the killing of leukemic cell line cells was enhanced considerably. Among the three EL, however, the combination of ET-18-OCH3 and heat seemed to be the most cytotoxic to leukemic cell line cells with no effect on the growth of hematopoietic progenitors. An increase in the duration of treatment with ET-18-OCH3 to four hours with heat added during the last hour resulted in a further reduction of leukemic cell line cells while sparing 50% of hematopoietic progenitors after cryopreservation. The combined treatment with ET-18-OCH3 and heat also inhibited the growth of leukemic progenitors obtained from AML patients by 97% to 100%. These data indicate that the combined treatment with EL and hyperthermia might offer an efficient means to eliminate myeloid leukemic cells in vitro. 相似文献
52.
Elevated numbers of primitive Philadelphia chromosome-positive (Ph+) progenitors, including long-term culture-initiating cells (LTC-IC) as well as colony-forming cells (CFC), have been previously described in the blood of patients with chronic myeloid leukemia (CML) in chronic phase with high white blood cell counts. In the present study, which focused primarily on an analysis of circulating progenitors present in such patients at diagnosis, we discovered the frequent and occasionally exclusive presence of circulating normal (Ph-) LTC-IC, often at levels above those seen for LTC-IC in the blood of normal individuals. The presence of detectable numbers of circulating Ph- LTC-IC was independent of the fact that the same peripheral blood samples also contained elevated numbers of predominantly or exclusively Ph+ CFC. Interestingly, both the Ph+ and Ph- LTC-IC in these samples were CD34+CD71- and variably CD38- and Thy-1+, as previously documented for LTC-IC in normal marrow. Thus, neither CD38 nor Thy-1 expression was useful for discriminating between Ph+ and Ph- LTC-IC in mixed populations. Nevertheless, an association of these phenotypes with LTC- IC function did allow highly enriched (> 5% pure) suspensions of either Ph+ or Ph- LTC-IC to be obtained from selected samples of CML blood in which the initial LTC-IC population was either predominantly Ph+ or Ph- , respectively. These findings suggest that the mechanisms causing mobilization of leukemic stem cells in untreated CML patients may affect their normal counterparts. They also indicate a possible new source of autologous cells for the support of intensive therapy of CML patients. Finally, they provide a method for obtaining the most highly purified populations of Ph+ LTC-IC described to date. This method should be useful for further analyses of the molecular activities of these very primitive neoplastic cells. 相似文献
53.
54.
Relations among handedness, eye dominance, and lateralisation in the formation of cataract were investigated in 35 male and 21 female patients with cataract. In right-handed patients, cataracts formed earlier in the right eyes than in the left eye; this was reversed in left-handed patients. For both right- and left-eye dominant patients, cataracts formed earlier in the dominant eye. 相似文献
55.
H. Yazici H. Fong B. Wilson E.E. Oren F.A. Amos H. Zhang J.S. Evans M.L. Snead M. Sarikaya C. Tamerler 《Acta biomaterialia》2013,9(2):5341-5352
Titanium (Ti) and its alloys are among the most successful implantable materials for dental and orthopedic applications. The combination of excellent mechanical and corrosion resistance properties makes them highly desirable as endosseous implants that can withstand a demanding biomechanical environment. Yet, the success of the implant depends on its osteointegration, which is modulated by the biological reactions occurring at the interface of the implant. A recent development for improving biological responses on the Ti-implant surface has been the realization that bifunctional peptides can impart material binding specificity not only because of their molecular recognition of the inorganic material surface, but also through their self-assembly and ease of biological conjugation properties. To assess peptide-based functionalization on bioactivity, the present authors generated a set of peptides for implant-grade Ti, using cell surface display methods. Out of 60 unique peptides selected by this method, two of the strongest titanium binding peptides, TiBP1 and TiBP2, were further characterized for molecular structure and adsorption properties. These two peptides demonstrated unique, but similar molecular conformations different from that of a weak binder peptide, TiBP60. Adsorption measurements on a Ti surface revealed that their disassociation constants were 15-fold less than TiBP60. Their flexible and modular use in biological surface functionalization were demonstrated by conjugating them with an integrin recognizing peptide motif, RGDS. The functionalization of the Ti surface by the selected peptides significantly enhanced the bioactivity of osteoblast and fibroblast cells on implant-grade materials. 相似文献
56.
57.
Selim Ayhan Serkan Ozturk Aytekin Alcelik Mehmet Fatih Ozlu Alim Erdem Tolga Memioglu Mesut Ozdemir Mehmet Yazici 《Journal of interventional cardiac electrophysiology》2012,35(3):247-252
Background
Prolonging atrial conduction time, as measured by tissue Doppler imaging (TDI), is an independent predictor of new onset or recurrent atrial fibrillation (AF). We investigated atrial conduction time and cardiac mechanical function in patients with impaired fasting glucose (IFG) using echocardiography.Methods
Thirty patients with IFG (19 males and 11 females; age, 46.9?±?9.5?years) and 30 control subjects (18 males and 12 females; age, 46.7?±?8.2?years) were included. Atrial conduction time was determined from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septal), and lateral tricuspid annulus (PA tricuspid) by TDI. Inter- and intra-atrial electromechanical delays (EMDs) were calculated. Left atrial (LA) volumes were determined according to the biplane area?Clength method. LA mechanical function parameters were calculated.Results
LA passive emptying volume and LA passive emptying fraction decreased significantly in patients with IFG as compared with control subjects (p?<?0.001 and p?<?0.001, respectively). PA lateral and PA septal durations were significantly higher in patients with IFG than in the control group. However, no difference in PA tricuspid duration was observed between the two groups. Inter- and intra-atrial EMDs were significantly higher in patients with IFG as compared with the control subjects (median [interquartile range], 34.0 [17.0] vs. 17.0 [4.0], p?<?0.001 and 15.0 [8.5] vs. 7.5 [2.0], p?<?0.001, respectively). Positive correlations were detected between both inter- and intra-atrial EMD and glucose levels (r?=?0.76, p?<?0.001 and r?=?0.68, p?<?0.001, respectively). Additionally, a multiple linear regression analysis revealed that glucose levels were independently associated with inter-atrial EMD (???=?0.753, p?<?0.001).Conclusion
We showed that IFG was associated with inter- and intra-atrial EMD. Our findings suggest that IFG is an etiological factor for the development of AF. 相似文献58.
Cenk Murat Yazici Banu Sarifakioglu Aliye Guzelant Polat Turker Ozkan Ates 《International urology and nephrology》2013,45(3):659-667
Purpose
Premature ejaculation (PE) and erectile dysfunction (ED) are both frequent diseases with several questions about the aetiological factors for these disorders. Lumbar disc herniation (LDH), which can cause both neurological and physiological impairments, may be a causative reason. We prospectively tried to evaluate the presence of PE and ED in patients with LDH and identify the effect of both surgical and physical therapy treatments for LDH on PE and ED.Methods
A total of 50 patients with LDH and a corresponding control group without LDH at an age of 18–50 years were included in the study. Both PE and ED were evaluated with premature ejaculation diagnostic tool (PEDT) and International Index of Erectile Function. Mean intravaginal ejaculatory latency time (IELT) was calculated at their 5 consecutive intercourse. Physical therapy or microdiscectomy was performed according to indication. After 6 months of follow-up, patients in treatment group were re-evaluated for PE and ED.Results
Mean age of study and control group was 34.1 ± 3.3 and 34.2 ± 4.0 years, respectively (p = 0.979). In LDH group, IELT was <1 min in 12 (24 %), 1–2 (16 %) min in 8, 2–3 min in 7 (14 %), 3–4 min in 7 (14 %) and 4 or more minutes in 16 (32 %) patients. These numbers were 11 (22 %), 8 (16 %), 5 (10 %), 9 (18 %) and 17 (34 %) in control group, respectively. Mean PEDT score of patients who had IELT < 1 min was 11.9 ± 2.1 and 10.7 ± 2.1 in study and control group, whereas it decreased to 1.0 ± 2.8 and 0.5 ± 1.8 as IELT increased over 4 min, respectively. There were 11 (22 %) patients with ED in LDH group, whereas there were only 2 (4 %) in control group (p = 0.017). Twenty patients with LDH underwent surgery while 30 had been taken into physical therapy. After 6 months, patients with PE significantly decreased in both surgery and physical therapy group (p = 0.025 and p = 0.046). Patients with ED also decreased after treatment, but the numbers were so limited for statistical evaluation.Conclusion
Although ED was more frequent in patients with LDH, PE was similar in both study and control groups, but the treatment of LDH had positive effects on PE and ED. 相似文献59.
A rare cause of breast mass that mimics carcinoma: Foreign body reaction to amorphous surgical material 总被引:2,自引:0,他引:2
Yazici B Sever AR Mills P Fish D Jones S Jones P 《Wiener klinische Wochenschrift》2007,119(15-16):497-499
A breast mass caused by foreign body type granulomatous reaction to surgical material is a very rare lesion and may mimic carcinoma. Reported foreign materials have included suture materials, silicone, paraffin, gunpowder and carbon particles used for localization of a nonpalpable breast lesions. To our knowledge, a foreign body reaction to gauze sponge has not been reported previously. A 58-year-old woman who had an enlarging mass that mimicked breast carcinoma, due to foreign body reaction to gauze sponge is presented here, and relevant literature is reviewed. 相似文献
60.
Yazici AR Tuncer D Dayangaç B Ozgünaltay G Onen A 《The journal of adhesive dentistry》2007,9(3):305-309
PURPOSE: To evaluate the effect of saliva contamination on the microleakage of an etch-and-rinse adhesive and a self-etching adhesive. MATERIALS AND METHODS: Class V cavity preparations at the cementoenamel junction were made on the buccal and lingual surfaces of 40 freshly extracted human molars. The teeth were randomly assigned into two groups for different adhesives: Group I, Single Bond (two-step etch-and-rinse adhesive) and Group II, Futura Bond NR (one-step self-etching adhesive). The adhesive materials were applied according to their manufacturers' recommendations. The specimens were then further subdivided into five subgroups (A-E; n = 8): group A, contamination before adhesive curing; group B, contamination before adhesive curing and re-application of adhesive; group C, contamination after adhesive curing; group D, contamination after adhesive curing and re-application of adhesive; and group E, no contamination (control). Contamination of adhesive surfaces was performed with fresh natural saliva and the saliva was removed by a gentle air blast. The specimens were restored with Z250 hybrid composite. After thermocycling (500x, 5 degrees C to 55 degrees C) and immersion in 0.5% basic fuchsin, the dye penetration was evaluated under a stereomicroscope. Statistical analysis was performed with the Kruskal-Wallis test at p < 0.05. RESULTS: No statistically significant differences were found among the contamination subgroups on the enamel or on the dentin for either group (p > 0.05). There was no significant difference in leakage between Group I and Group II for any subgroup (p > 0.05). CONCLUSION: Contamination of adhesives with saliva before and after adhesive curing did not worsen the microleakage of the two-step etch-and-rinse adhesive Single Bond or the one-step self-etching adhesive Futura Bond NR. 相似文献