全文获取类型
收费全文 | 39318篇 |
免费 | 2506篇 |
国内免费 | 116篇 |
专业分类
耳鼻咽喉 | 641篇 |
儿科学 | 2155篇 |
妇产科学 | 818篇 |
基础医学 | 4586篇 |
口腔科学 | 872篇 |
临床医学 | 3160篇 |
内科学 | 7594篇 |
皮肤病学 | 859篇 |
神经病学 | 1995篇 |
特种医学 | 876篇 |
外科学 | 6846篇 |
综合类 | 1326篇 |
一般理论 | 15篇 |
预防医学 | 2150篇 |
眼科学 | 1920篇 |
药学 | 3493篇 |
中国医学 | 274篇 |
肿瘤学 | 2360篇 |
出版年
2023年 | 275篇 |
2022年 | 612篇 |
2021年 | 1170篇 |
2020年 | 721篇 |
2019年 | 869篇 |
2018年 | 1159篇 |
2017年 | 842篇 |
2016年 | 1092篇 |
2015年 | 1124篇 |
2014年 | 1605篇 |
2013年 | 2019篇 |
2012年 | 2506篇 |
2011年 | 2545篇 |
2010年 | 1582篇 |
2009年 | 1535篇 |
2008年 | 1873篇 |
2007年 | 1814篇 |
2006年 | 1895篇 |
2005年 | 1451篇 |
2004年 | 1425篇 |
2003年 | 1214篇 |
2002年 | 1035篇 |
2001年 | 911篇 |
2000年 | 907篇 |
1999年 | 779篇 |
1998年 | 397篇 |
1997年 | 333篇 |
1996年 | 332篇 |
1995年 | 324篇 |
1994年 | 278篇 |
1993年 | 235篇 |
1992年 | 592篇 |
1991年 | 474篇 |
1990年 | 477篇 |
1989年 | 454篇 |
1988年 | 427篇 |
1987年 | 389篇 |
1986年 | 393篇 |
1985年 | 351篇 |
1984年 | 298篇 |
1983年 | 242篇 |
1982年 | 173篇 |
1979年 | 248篇 |
1978年 | 163篇 |
1977年 | 187篇 |
1975年 | 184篇 |
1974年 | 190篇 |
1973年 | 189篇 |
1972年 | 179篇 |
1971年 | 168篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Vasvi Singh Andrew D. Choi Jonathon Leipsic Ayaz Aghayev James P. Earls Philipp Blanke Michael Steigner Leslee J. Shaw Phd Marcelo F. Di Carli Todd C. Villines Ron Blankstein 《Journal of Cardiovascular Computed Tomography》2021,15(1):16-26
The COVID-19 pandemic has affected patient care deliver throughout the world, resulting in a greater emphasis on efficiently and safety. In this article, we discuss the experiences of several North American centers in utilizing cardiac CT during the pandemic. We also provide a case-based overview which highlights the advantages of cardiac CT in evaluating the following scenarios: (1) patients with possible myocardial injury versus myocardial infarction; (2) patients with acute chest pain; (3) patients with stable chest pain; (4) patients with possible intracardiac thrombus; (5) patients with valvular heart disease. For each scenario, we also provide an overview of various societies recommendations which have highlighted the use of cardiac CT during different phases of the COVID-19 pandemic. We hope that the advantages of cardiac CT that have been realized during the pandemic can help promote wider adoption of this technique and improved coverage and payment by payors. 相似文献
992.
Harisankar Singha Baldev R. Gulati Prabhat Kumar Birendra K. Singh Nitin Virmani Raj K. Singh 《Archives of virology》2013,158(1):113-122
The complete genome of the Japanese encephalitis virus (JEV) strain JEV/eq/India/H225/2009(H225), isolated from an infected horse in India, was sequenced and compared to previously published JEV genomes. H225 genome was 10,977-nucleotides long, comprising a single ORF of 10,299-nucleotides, a 5′-UTR of 95 nucleotides and a 3′-UTR of 582 nucleotides. The H225 genome showed high levels of sequence identity with 47 fully sequenced JEV genomes, ranging from 99.3 % to 75.5 % for nucleotides and 99.2 % to 91.5 % for amino acid sequences. Phylogenetic analysis of the full-length sequence indicated that the H225 strain belongs to genotype III and is closely related to the Indian JEV strain Vellore P20778. A comparison of amino acids associated with neurovirulence in the E proteins and non-structural proteins of known virulent and attenuated JEV strains suggested H225 to be a highly virulent strain. This is the first report of whole-genome sequencing of a genotype III JEV genome isolated from equines. 相似文献
993.
Microwave sensor for the investigation of glucose-dependent reflection properties in aqueous samples
Satish Singh Rajesh Singh Kushal Sen Sneh Anand 《Journal of medical engineering & technology》2013,37(4):217-222
AbstractThe reported paper presents the development of a microwave sensor with a resonant frequency 2.4?GHz. The sensor is also demonstrated in vitro to investigate the variation in its response as a function of glucose concentration. The sensor could be used for the monitoring of blood glucose level in diabetics through non-invasive technology. The approach followed is based on the notion that, change in glucose concentration in the blood affects dielectric properties of blood which in turn produce an impact on reflection properties of the sensor. This effect on response of sensor will be ultimately used to estimate blood glucose concentration. The design specifications considered for the development of sensor are defined in the paper. The experimental setup for in vitro experiment and procedure employed for the investigation of the reflection properties of the sensor as a function of glucose concentration are also discussed in detail. The shift in resonance frequency and the change in the magnitude of the reflection coefficient of proposed sensor have been observed. The reported measurement results are the preliminary results in exploring the implementation of proposed sensor for non-invasive blood glucose monitoring. 相似文献
994.
995.
Neeta Kumar Sushma Bhatnagar T Velpandian Santosh Patnaik Geetha Menon Manju Mehta Komal Kashyap Vishwajeet Singh Surajpal 《Indian Journal of Palliative Care》2013,19(3):180-185
Objective:
The objective of this study is to examine the effect of a cognitive, behavioral stress management module of Sudarshan Kriya (SK) and P on levels of serum cortisol and pain among the women suffering from advanced stage breast cancer.Materials and Methods:
Participants (n = 147) were screened and randomized to receive standard care (n = 69) versus standard along with SK and Pranayam (P) intervention (n = 78) imparted in one 18 hrs workshop spread during 3 days. Participants were expected to practice it at home 20 min daily as adjuvant to standard pharmacological treatment for pain.Results:
There was a significant difference in blood cortisol levels after 3 months of practice of SK and P. Mean blood levels in the intervention arm were 341.2 ng/ml against 549.2 ng/ml in the control arm (P ≤ 0.002). Pain perception in comparison to control arm reduced by 3 points in SK and P arm on 0-10 verbal scale of pain.Conclusion:
SK and P is an effective intervention in reducing stress and pain among advance stage patients of breast cancer. 相似文献996.
Piyush Narayan Mallick Surjya Prasad Upadhyay Raj Kumar A Singh Shiv Kumar Singh 《Indian Journal of Critical Care Medicine》2013,17(2):113-115
Poor neurological outcome is a common sequel of prolonged cardiac arrest. Although Therapeutic Hypothermia (TH) for neuroprotection has been a subject for research for over Half a century, its use has been limited because of many controversies and lack of clear guidelines. However for over two decades there has been a revival of interest in mild therapeutic hypothermia (32-34°C) for neuroprotection. However its use after primary asystolic cardiac arrest has been questioned.Herein presenting two cases of prolonged asystolic arrest (39 minutes and 25 minutes); where therapeutic hypothermia was successfully used in following prolonged cardio pulmonary resuscitation. On patients who were in deep coma after resuscitation, TH was applied for 24 hours as per institutional protocol with full neurological recovery in both the cases. Therapeutic hypothermia might have a potential role in even in non-shockable arrests and should be considered in every successful cardiopulmonary resuscitation with poor neurological status. 相似文献
997.
Abhijit Chandra Vishal Gupta Manoj Kumar Anit Parihar Ashok Kumar Ramendra Jauhari Devendra Singh P. K. Shrivastav Pankaj Kumar 《Surgical and radiologic anatomy : SRA》2013,35(1):67-74
Purpose
Antropylorus transposition in the perineum for end-stage anal incontinence has shown to be feasible in humans. Vascular anatomy of the antro-pyloro-duodenal area is critical in preventing complications and increasing pyloric graft survival. This study was undertaken to examine the vascular anatomy of antro-pyloro-duodenal area in an attempt to safeguard the graft blood supply and improve its survival.Methods
After obtaining preoperative CT angiography to delineate the infrapyloric artery (IP a.), bench dissection of resected pancreaticoduodenectomy specimens was performed in 12 patients. Ex vivo angiography of these specimens were also performed. Subsequent to the information obtained from these dissections, the method of antropylorus mobilization during transposition was modified in terms of the site of division of the right gastroepiploic a. (Rt GEA). Perioperative outcomes (graft related complications, fecal incontinence scores, Doppler flow studies, and manometry studies of the graft) were compared between the two groups.Results
IP a. originated only from the Rt GEA in 8 cases (66 %) and from both the gastroduodenal a. and the Rt GEA in the rest. However, its origin solely from the gastroduodenal a. was not observed. The pyloric graft survival, pyloric valve pressures and Doppler flow velocities were significantly (p < 0.05) better when the infrapyloric a. was preserved following this refinement. However, no immediate significant difference in incontinence scores was observed.Conclusions
Careful preservation of the pyloric valve vascularity by preserving the IP a. by dividing the Rt GEA at its origin increases vascularity, survival and contractility of the pyloric graft in perineum. 相似文献998.
MALDI mass sequencing and biochemical characterization of Setaria cervi protein tyrosine phosphatase
Reeta Rai Neetu Singh Srikanth Elesela Savitri Tiwari Sushma Rathaur 《Parasitology research》2013,112(1):147-154
A 30-kDa acid phosphatase with protein tyrosine phosphatase activity was identified in Setaria cervi (ScPTP). The enzyme was purified to homogeneity using three-step column chromatography. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis of purified ScPTP yielded a total of eight peptides matching most closely to phosphoprotein phosphatase of Ricinus communis (RcPP). A hydrophilicity plot of RcPP revealed the presence of these peptides in the hydrophilic region, suggesting their antigenic nature. The substrate specificity of ScPTP with ortho-phospho-l-tyrosine and inhibition with sodium orthovanadate and ammonium molybdate affirmed it as a protein tyrosine phosphatase. ScPTP was also found to be tartrate resistant. The Km and Vmax were 6.60 mM and 83.3 μM/ml/min, respectively, with pNPP and 8.0 mM and 111 μM/ml/min, respectively, with ortho-phospho-l-tyrosine as the substrate. The Ki value with sodium orthovanadate was calculated to be 16.10 mM. Active site modification with DEPC, EDAC and pHMB suggested the presence of histidine, cysteine and aspartate at its active site. Thus, on the basis of MALDI-TOF and biochemical studies, it was confirmed that purified acid phosphatase is a PTP. 相似文献
999.
1000.