全文获取类型
收费全文 | 16244篇 |
免费 | 1242篇 |
国内免费 | 407篇 |
专业分类
耳鼻咽喉 | 140篇 |
儿科学 | 360篇 |
妇产科学 | 314篇 |
基础医学 | 1580篇 |
口腔科学 | 235篇 |
临床医学 | 1400篇 |
内科学 | 2299篇 |
皮肤病学 | 316篇 |
神经病学 | 684篇 |
特种医学 | 871篇 |
外国民族医学 | 8篇 |
外科学 | 3465篇 |
综合类 | 1838篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 498篇 |
眼科学 | 120篇 |
药学 | 1201篇 |
11篇 | |
中国医学 | 662篇 |
肿瘤学 | 1889篇 |
出版年
2024年 | 36篇 |
2023年 | 268篇 |
2022年 | 453篇 |
2021年 | 707篇 |
2020年 | 690篇 |
2019年 | 617篇 |
2018年 | 659篇 |
2017年 | 550篇 |
2016年 | 639篇 |
2015年 | 563篇 |
2014年 | 1000篇 |
2013年 | 1012篇 |
2012年 | 778篇 |
2011年 | 891篇 |
2010年 | 780篇 |
2009年 | 808篇 |
2008年 | 797篇 |
2007年 | 790篇 |
2006年 | 668篇 |
2005年 | 663篇 |
2004年 | 577篇 |
2003年 | 469篇 |
2002年 | 383篇 |
2001年 | 327篇 |
2000年 | 240篇 |
1999年 | 236篇 |
1998年 | 254篇 |
1997年 | 209篇 |
1996年 | 229篇 |
1995年 | 176篇 |
1994年 | 162篇 |
1993年 | 142篇 |
1992年 | 125篇 |
1991年 | 119篇 |
1990年 | 109篇 |
1989年 | 94篇 |
1988年 | 81篇 |
1987年 | 61篇 |
1986年 | 57篇 |
1985年 | 88篇 |
1984年 | 59篇 |
1983年 | 39篇 |
1982年 | 52篇 |
1981年 | 49篇 |
1980年 | 43篇 |
1979年 | 35篇 |
1978年 | 29篇 |
1977年 | 29篇 |
1976年 | 14篇 |
1975年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
超声引导下VacoraTM旋切系统的实验研究 总被引:1,自引:0,他引:1
目的探讨VacoraTM真空辅助活检系统的准确性和安全性,为临床应用奠定基础。方法选用里脊肉和鱼丸作为实验材料,根据鱼丸大小将实验分为5组:0.5、0.8、1.0、1.5及2.0cm组,每组鱼丸3~5个。采用VacoraTM活检系统,先行灰阶超声扫查肌肉后将鱼丸置入肌肉中,超声扫查置入的鱼丸,同轴套管针在超声引导下插入鱼丸底部,在套管针引导和超声监视下行旋切真空抽吸术;旋切后取出采样腔内的组织标本,用超声检查肌肉内的残腔,确定无鱼丸残留声像图。结果每次旋切组织条比较完整,其大小为20.0mm×0.6mm,旋切次数随鱼丸大小的增加而增加;0.5、0.8、1.0、1.5及2.0cm组里脊肉内鱼丸全部切除的平均旋切次数分别为12、15、19、26和31。所用的平均时间分别为15、18、23、27和34min。结论VacoraTM真空辅助活检系统定位准确、取样完整、操作简便。可为良恶性病变的诊断提供足够量的病理检查标本,为良性病变的完全切除提供具有潜在价值的手段。 相似文献
32.
Tacrolimus Exposure and Evolution of Renal Allograft Histology in the First Year After Transplantation 总被引:1,自引:1,他引:0
M. Naesens E. Lerut B. V. Damme Y. Vanrenterghem D. R. J. Kuypers 《American journal of transplantation》2007,7(9):2114-2123
Tacrolimus has a narrow therapeutic window and is characterized by a large inter-individual variability in bioavailability. The impact of tacrolimus exposure on subclinical evolution of graft histology has not been studied in renal recipients. This analysis included 239 protocol biopsies (obtained at implantation, 3 and 12 months) of 120 consecutive kidney recipients treated with tacrolimus, mycophenolate mofetil (MMF) and corticosteroids. Biopsies were scored according to the Banff 2001 criteria and a chronicity score was calculated. Prospective pharmacokinetic data were included in the analysis (5544 tacrolimus predose blood concentrations and tacrolimus AUC(0-12) at 3 and 12 months). Higher donor age and higher number of human leukocyte antigen-DR (HLA-DR) mismatches were independent predictors of subclinical acute rejection at 3 months, present in 8.7% of patients. The number of HLA-DR mismatches was independently associated with biopsy-proven clinical acute rejection. Biopsy-proven acute rejection episodes and low mean tacrolimus exposure were independently associated with higher increase in chronicity scores between 3 and 12 months after transplantation. This observational study suggests that rejection phenomena and immune-mediated mechanisms remain important in the early progression of chronic allograft pathology. Tacrolimus doses or systemic exposure were not associated with lesions of calcineurin inhibitor nephrotoxicity, suggesting that other factors determine susceptibility to tacrolimus nephrotoxicity. 相似文献
33.
目的 总结和评价经直肠超声引导下前列腺穿刺活检术对前列腺癌诊断的准确率。方法 222 例直肠指检阳性或 PSA>4μg/L的患者应用经直肠超声引导下前列腺6点系统穿刺活检以明确诊断。结果 222 例受检者中病理证实前列腺结节性增生41例、前列腺炎24例、前列腺肉瘤3例、前列腺癌 154 例,其中低分化癌 74 例、中分化癌 58 例、高分化癌 22 例。术后血尿15例、发热6例,其中高热1例,经抗生素治疗后体温恢复正常、尿检阴性。结论 经直肠超声引导下前列腺穿刺活检无需麻醉,患者痛苦小、安全性高,是诊断前列腺癌的可靠方法。 相似文献
34.
35.
Katsumi Shigemura Soichi Arakawa Kunito Yamanaka Nobuo Kataoka Keiji Yuien Masato Fujisawa 《International journal of urology》2007,14(10):935-938
OBJECTIVES: Lateral biopsies are thought to have a better cancer detection rate compared with standard sextant biopsies. This study aimed to determine whether lateral peripheral zone biopsies in Japanese men who underwent transrectal ultrasound-guided prostate biopsies provided a significantly higher cancer detection rate than sextant biopsies. METHODS: Between 1999 and 2004, data were collected from 461 men who underwent prostate biopsy and had enough data regarding the performance of lateral biopsies for statistical analysis. There were two categories in this study: (i) patients who underwent sextant prostate biopsies; and (ii) patients who underwent sextant biopsies plus lateral biopsies. RESULTS: Prostate cancer was detected in 141 (30.6%) of 461 patients. It was detected in 24 (22.2%) of 108 patients who underwent sextant biopsies and 117 (33.1%) of 353 patients who underwent sextant plus lateral biopsies. Lateral biopsies were not associated with a statistically higher rate of positive biopsy findings; however, we found a significantly higher ratio of patients with positive findings in those with prostate specific antigen (PSA) levels 10 ng/mL (one of 71, 1.4%) among those who had positive cores only in lateral biopsy samples (P < 0.0001). CONCLUSIONS: Lateral biopsies did not show a significantly higher detection ratio of prostate cancer compared to sextant biopsies. However, lateral biopsies were more effective than sextant biopsies in patients with lower PSA levels. Our findings might be useful for the establishment of biopsy strategies to detect prostate cancer, especially in patients with lower PSA levels. 相似文献
36.
Robbert-Jan Roozeman Lasse Murtomäki Kyösti Kontturi 《Journal of electroanalytical chemistry (Lausanne, Switzerland)》2005,575(1):9-17
A recently introduced setup to measure the dynamic interfacial tension of expanding drops was used to compare the adsorption behaviour of a series of lipids at the electrified water∣dichloroethane interface. Phospholipids with saturated carbon chains of different length (DMPC, DPPC, DSPC, DAPC, DBPC), an unsaturated phospholipid (DOPC) and an ethanolamine (DSPE) were compared. It was found that the adsorption decreases with increasing chain length. Also, the increase of the flow rate reduces the degree of adsorption effectively. On the timescale of the experiments, the DSPE, DAPC and DBPC adsorption showed no potential dependence, whereas the adsorption of DOPC was stronger than that of the saturated lipids. Adsorption was modelled using the Langmuir adsorption isotherm; the potential dependence of adsorption is discussed. 相似文献
37.
J. G. Boonstra Johan W. van der Pijl Yves F. C. Smets Herman H. P. J. Lemkes Jan Ringers Leendert A. van Es F. J. van der Woude Jan A. Bruijn 《Transplant international》1997,10(6):451-456
To examine the incidence of interstitial and vascular
rejection in pancreas allografts and its impact on graft survival, we studied 36 percutaneous pancreas biopsies and 10 pancreas
transplantectomy specimens from 32 patients who had undergone simultaneous pancreas-kidney transplantation. Interstitial rejection
(IR) was predominantly found in the biopsies, while vascular rejection (VR) was most prominent in the transplantectomies.
Pancreas graft survival was significantly decreased for pancreas grafts that had suffered from vascular rejection when compared
to those with only interstitial rejection. Potential rejection markers, i. e., serum amylase, glucose, creatinine, and urinary
amylase, did not correlate with histological signs of rejection, although increased levels of serum amylase were, in all but
one case, associated with rejection.We conclude that a percutaneous pancreas biopsy remains the most reliable method to determine
pancreas rejection, and that by distinguishing between IR andVR, a pancreas biopsy may provide important diagnostic as well
as prognostic information.
Received: 6 March 1997 Received after revision: 5 June 1997 Accepted: 30 June 1997 相似文献
38.
Lorenzo E. Derchi Carlo Martinoli Roberto Pontremoli Stefano Saffioti Caterina Pastorino 《European radiology》1993,3(2):186-189
Two patients with arteriovenous fistulas of the native kidney occurring after needle biopsy were evaluated using duplex and color Doppler ultrasonography. The first patient had a fistula with associated pseudoaneurysm: color Doppler showed the lesion as a small rounded area with whirling flow; spectral analysis allowed recognition of both the afferent artery with low impedance flow and the draining vein with pulsatile, arterialized flow. The second patient had a normal color Doppler study; however, spectral analysis demonstrated signals with low vascular impedance from an intra-parenchymal artery at the lower pole, and a jet of turbulent flow. Following disappearance of clinical findings, such Doppler abnormalities were no longer detectable. When a iatrogenic arteriovenous fistula is considered on clinical grounds, both color and Doppler spectral analysis of waveforms from intra-parenchymal vessels should be performed. Possibly, further advances in color Doppler technology will permit the use of this examination as the first imaging procedure in these clinical situations.Correspondence to: L. E. Derchi 相似文献
39.
Maite Sainz De La Maza Ramzy K. Hemady C. Stephen Foster 《Documenta ophthalmologica. Advances in ophthalmology》1993,83(1):33-41
While systemic autoimmune diseases are the main possibilities in the differential diagnosis of scleritis, other less common etiologies such as infections must also be considered. The authors report four cases of infectious scleritis to review predisposing factors, clinical characteristics, methods of diagnostic approach, and response to therapy. Two patients had primary scleritis and two patients had secondary scleritis following extension of primary corneal infection (corneoscleritis). Diagnoses included three local infections (one each withStaphylococcus. Acanthamoeba, and herpes simplex) and one systemic infection (Lyme disease). Stains, cultures, or immunologic studies from scleral, conjunctival, and/or corneal tissues, and serologic tests were used to make the diagnosis. Medical therapy, including antimicrobial agents, was instituted in all patients, and surgical procedures were additionally required in two patients (scleral grafting in one and two penetrating keratoplasties in another); the patient who required two penetrating keratoplasties had corneoscleritis and underwent eventual enucleation. Infectious agents should be considered in the differential diagnosis of scleritis. 相似文献
40.
Robert C Susil Kevin Camphausen Peter Choyke Elliot R McVeigh Gary S Gustafson Holly Ning Robert W Miller Ergin Atalar C Norman Coleman Cynthia Ménard 《Magnetic resonance in medicine》2004,52(3):683-687
A technique for transperineal high-dose-rate (HDR) prostate brachytherapy and needle biopsy in a standard 1.5 T MRI scanner is demonstrated. In each of eight procedures (in four patients with intermediate to high risk localized prostate cancer), four MRI-guided transperineal prostate biopsies were obtained followed by placement of 14-15 hollow transperineal catheters for HDR brachytherapy. Mean needle-placement accuracy was 2.1 mm, 95% of needle-placement errors were less than 4.0 mm, and the maximum needle-placement error was 4.4 mm. In addition to guiding the placement of biopsy needles and brachytherapy catheters, MR images were also used for brachytherapy treatment planning and optimization. Because 1.5 T MR images are directly acquired during the interventional procedure, dependence on deformable registration is reduced and online image quality is maximized. 相似文献