全文获取类型
收费全文 | 8029篇 |
免费 | 421篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 118篇 |
儿科学 | 528篇 |
妇产科学 | 118篇 |
基础医学 | 975篇 |
口腔科学 | 145篇 |
临床医学 | 526篇 |
内科学 | 1481篇 |
皮肤病学 | 227篇 |
神经病学 | 547篇 |
特种医学 | 125篇 |
外科学 | 1123篇 |
综合类 | 215篇 |
一般理论 | 8篇 |
预防医学 | 497篇 |
眼科学 | 262篇 |
药学 | 932篇 |
中国医学 | 47篇 |
肿瘤学 | 591篇 |
出版年
2023年 | 41篇 |
2022年 | 114篇 |
2021年 | 305篇 |
2020年 | 176篇 |
2019年 | 226篇 |
2018年 | 272篇 |
2017年 | 189篇 |
2016年 | 235篇 |
2015年 | 265篇 |
2014年 | 352篇 |
2013年 | 397篇 |
2012年 | 622篇 |
2011年 | 609篇 |
2010年 | 373篇 |
2009年 | 270篇 |
2008年 | 493篇 |
2007年 | 441篇 |
2006年 | 432篇 |
2005年 | 378篇 |
2004年 | 389篇 |
2003年 | 297篇 |
2002年 | 239篇 |
2001年 | 143篇 |
2000年 | 133篇 |
1999年 | 117篇 |
1998年 | 79篇 |
1997年 | 50篇 |
1996年 | 44篇 |
1995年 | 39篇 |
1994年 | 30篇 |
1993年 | 37篇 |
1992年 | 68篇 |
1991年 | 56篇 |
1990年 | 40篇 |
1989年 | 69篇 |
1988年 | 50篇 |
1987年 | 28篇 |
1986年 | 33篇 |
1985年 | 29篇 |
1984年 | 27篇 |
1983年 | 44篇 |
1982年 | 15篇 |
1981年 | 19篇 |
1980年 | 22篇 |
1979年 | 25篇 |
1978年 | 16篇 |
1977年 | 15篇 |
1973年 | 19篇 |
1972年 | 14篇 |
1970年 | 13篇 |
排序方式: 共有8465条查询结果,搜索用时 15 毫秒
1.
2.
3.
Prabhakaran Dhanasekaran Swaminathan Rajavarman Sivasuriyanarayanan Vinod Selvaganesh Santoshkumar Dattatray Bhat 《Materials》2021,14(9)
Nanocrystalline platinum with different morphologies is synthesized via electrochemical deposition technique. The nucleation mechanism and its structural effect over the electrodeposited Pt on carbon electrodes have been systematically studied. Powder X-ray diffraction, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy are employed to study nucleation, oxidation states, and Pt structure growth on a carbon electrode. This study reports significant development of Pt metal nanoparticles with different morphologies such as a sphere, flower, core-flower, and rod-like structure directly fabricated on carbon electrode while tuning the deposition parameters such as current density, time, temperature, pH during the deposition process. The proposed electrochemical route represents a superior fabrication procedure for large-scale electrode fabrication compared to a conventional method for preparing membrane electrode assemblies for fuel cell stacks. 相似文献
4.
Joseph F. Levy Rahul Khairnar Alexander V. Louie Timothy N. Showalter C. Daniel Mullins Mark V. Mishra 《Practical radiation oncology》2019,9(2):e172-e179
Purpose
A hydrogel rectal spacer (HRS) is a medical device that is approved by the U.S. Food and Drug Administration to increase the separation between the prostate and rectum. We conducted a cost-effectiveness analysis of HRS use for reduction in radiation therapy (RT) toxicities in patients with prostate cancer (PC) undergoing external beam RT (EBRT).Methods and Materials
A multistate Markov model was constructed from the U.S. payer perspective to examine the cost-effectiveness of HRS in men with localized PC receiving EBRT (EBRT alone vs EBRT + HRS). The subgroups analyzed included site of HRS placement (hospital outpatient, physician office, ambulatory surgery center) and proportion of patients with good baseline erectile function (EF). Data on EF, gastrointestinal and genitourinary toxicities incidence, and potential risks associated with HRS implantation were obtained from a recently published randomized clinical trial. Health utilities and costs were derived from the literature and the 2018 Physician Fee Schedule and were discounted 3% annually. Quality-adjusted life years (QALYs) and costs were modeled for a 5-year period from receipt of RT. Probabilistic sensitivity analysis and value-based threshold analyses were conducted.Results
The per-patient 5-year incremental cost for spacers administered in a hospital outpatient setting was $3578, and the incremental effectiveness was 0.0371 QALYs. The incremental cost-effectiveness ratio was $96,440/QALY for patients with PC undergoing HRS insertion in a hospital and $39,286/QALY for patients undergoing HRS insertion in an ambulatory facility. For men with good baseline EF, the incremental cost-effectiveness ratio was $35,548/QALY and $9627/QALY in hospital outpatient and ambulatory facility settings, respectively.Conclusions
Based on the current Medicare Physician Fee Schedule, HRS is cost-effective at a willingness to pay threshold of $100,000. These results contain substantial uncertainty, suggesting more evidence is needed to refine future decision-making. 相似文献5.
Soosai Manickam Amirtham Ozlem Ozbey Upasana Kachroo Boopalan Ramasamy Elizabeth Vinod 《Clinical anatomy (New York, N.Y.)》2020,33(3):343-349
Bone containing tissues such as osteochondral joint are resistant to routine tissue processing, therefore require decalcification. This technique causes removal of mineral salts, but in the process may macerate the organic tissue, hence the need for tissue fixation. Such severe processing demands careful antigen retrieval to necessitate optimal staining. The aim of our study was to compare five different antigen retrieval protocols (heat retrieval and protein digestion) following decalcification of rabbit knee joints using two different techniques (20% formic acid and 10% ethylenediamine-tetra acetic acid: EDTA). Osteochondral sections were compared based on time required for decalcification, ease of sectioning, morphological integrity using HE staining and antigen preservation (Collagen type II) using immunohistochemistry. The two decalcification solutions did not impair the tissue morphology and ease of sectioning. Joints processed with formic acid decalcified four times faster than EDTA. Among the five antigen retrieval approaches, maximal collagen II uptake with minimal nonspecific staining was found with protein digestion (pronase and hyaluronidase) in both formic acid and EDTA sections. For osteo-chondral sections, we recommend using 10% EDTA for decalcification and pronase plus hyaluronidase for antigen retrieval if maintaining tissue morphology is crucial, whereas if time is of the essence, 20% FA with pronase plus hyaluronidase is the faster option while still preserving structural integrity. Clin. Anat. 33:343–349, 2020. © 2019 Wiley Periodicals, Inc. 相似文献
6.
Mohamed El-Sherbiny Mohamed Ahmed Eladl Anu Vinod Ranade Maha Guimei Hala Gabr 《Singapore medical journal》2020,61(1):39
INTRODUCTIONThis study aimed to investigate the therapeutic response to injected human umbilical cord blood mesenchymal stem cells (UCBMSCs) among albino rats with streptozotocin (STZ)-induced diabetes mellitus.METHODSControl group (GI; n = 25) rats were fed with standard rat diet. Rats with STZ-induced diabetes mellitus without (GII; n = 25) and with (GIII; n = 25) differentiated human UCBMSCs implantation were the test groups. Rats were sacrificed in Week 11 following implantation. Liver biopsies were sectioned and stained in order to highlight both the presence and function of impregnated cells in the liver tissue.RESULTSHaematoxylin and eosin-stained sections in GI and GII rats showed normal liver architecture while GIII rats showed presence of cell clusters inside the liver tissue and around the central veins. Cell clusters with blue cytoplasm were present in sections in GIII rats but absent in GI and GII rats, indicating the presence of injected differentiated human UCBMSCs. The anti-human insulin immunostaining of GIII rats showed clusters of cells within the liver parenchyma and around central veins, indicating that these cells were active and secreting insulin.CONCLUSIONUCBMSCs are proficient in differentiating into insulin-producing cells in vivo under specific conditions and, when transplanted into the liver of albino rats with STZ-induced diabetes mellitus, were able to secrete insulin and partially control the status of diabetes mellitus in rats. 相似文献
7.
Metabolic abnormalities of gastrointestinal mucosa in celiac disease: An in vitro proton nuclear magnetic resonance spectroscopy study
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
8.
Pankaj Kumar Mishra 《European journal of cardio-thoracic surgery》2006,29(5):861-2; author reply 862
9.
Evaluation of polymerase chain reaction and adenosine deaminase assay for the diagnosis of tuberculous effusions in children. 总被引:2,自引:0,他引:2
AIM: To evaluate and compare the utility of polymerase chain reaction (PCR) for the diagnosis of tuberculous effusions in children. METHODS: PCR, adenosine deaminase (ADA) activity and absolute lymphocyte count (ALC) were evaluated in the fluid of 31 tuberculous (20 pleural, 8 ascites and 3 pericardial) and 24 non-tuberculous (10 transudtative ascites, 8 empyema thoracis, 3 malignant pleural and 3 pyopericardium) effusions. RESULTS: Fluid PCR for Mycobacterium tuberculosis was positive in 74% of tuberculous effusions, whereas it was falsely positive in 13% of the non-tuberculous group. The mean fluid ADA and ALC values were significantly higher in tuberculous effusions than in non-tuberculous effusions (p<0.001). The sensitivity and specificity of PCR, ADA (> or =38 IU/l) and ALC (> or =275/mm3) were 74% and 88%, 81% and 75%, and 90% and 83%, respectively, in diagnosing tuberculous effusions. The sensitivity of PCR, ADA and ALC was 100%, 100% and 88%, respectively, for confirmed tuberculous effusions. When the two tests were combined (either/or positive), the sensitivity increased (90-100%) at the expense of specificity. When both the tests were positive, then the specificity markedly increased (92-96%), but sensitivity of the tests decreased. CONCLUSION: Fluid PCR alone should not be relied on as a single test; rather, combined analysis with either ADA or ALC could be more useful in the diagnosis of tuberculous effusions in children. 相似文献
10.
Gaurav Agarwal Sadhna Dhingra Saroj K. Mishra Narendra Krishnani 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》2006,391(6):623-626
Introduction Fine needle aspiration cytology is not a commonly employed diagnostic modality in the diagnosis of parathyroid tumors.Case report A 28 year old lady being followed-up for 5 years after en bloc resection of a parathyroid carcinoma presented with a nodule in the lower neck, away from the parathyroidectomy scar. The 1 cm isolated nodule was located in the muscular and subcutaneous plane and corresponded to the needle track of FNA performed on a neck nodule before the parathyroidectomy. On evaluation, she had mild hypercalcemia and high normal serum parathyroid hormone levels. FNAC and histology including immunohistochemistry for Chromogranin A after local excision of the nodule confirmed the nodule to be a recurrent parathyroid carcinoma along the needle track.Discussion To the best of the authors’ knowledge, this is only the second case of needle track implantation after FNA in parathyroid carcinoma reported to date. This case highlights the risk of engraftment of parathyroid tissue after FNA and cautions against the use of FNA as a preoperative diagnostic modality for the evaluation of parathyroid lesions.Drs. Agarwal and Dhingra have contributed equally, as joint first authors. 相似文献