全文获取类型
收费全文 | 39955篇 |
免费 | 2180篇 |
国内免费 | 139篇 |
专业分类
耳鼻咽喉 | 526篇 |
儿科学 | 2570篇 |
妇产科学 | 698篇 |
基础医学 | 4796篇 |
口腔科学 | 1125篇 |
临床医学 | 2890篇 |
内科学 | 7217篇 |
皮肤病学 | 1121篇 |
神经病学 | 2361篇 |
特种医学 | 1178篇 |
外科学 | 6000篇 |
综合类 | 1281篇 |
一般理论 | 17篇 |
预防医学 | 2035篇 |
眼科学 | 1454篇 |
药学 | 4009篇 |
1篇 | |
中国医学 | 352篇 |
肿瘤学 | 2643篇 |
出版年
2023年 | 326篇 |
2022年 | 954篇 |
2021年 | 1622篇 |
2020年 | 887篇 |
2019年 | 979篇 |
2018年 | 1384篇 |
2017年 | 1006篇 |
2016年 | 1331篇 |
2015年 | 1340篇 |
2014年 | 1971篇 |
2013年 | 2235篇 |
2012年 | 3139篇 |
2011年 | 3072篇 |
2010年 | 1844篇 |
2009年 | 1457篇 |
2008年 | 2054篇 |
2007年 | 2082篇 |
2006年 | 1891篇 |
2005年 | 1684篇 |
2004年 | 1568篇 |
2003年 | 1325篇 |
2002年 | 1138篇 |
2001年 | 772篇 |
2000年 | 708篇 |
1999年 | 591篇 |
1998年 | 265篇 |
1997年 | 215篇 |
1996年 | 220篇 |
1995年 | 187篇 |
1994年 | 155篇 |
1993年 | 130篇 |
1992年 | 350篇 |
1991年 | 335篇 |
1990年 | 358篇 |
1989年 | 329篇 |
1988年 | 286篇 |
1987年 | 241篇 |
1986年 | 234篇 |
1985年 | 228篇 |
1984年 | 174篇 |
1983年 | 122篇 |
1982年 | 68篇 |
1981年 | 75篇 |
1980年 | 69篇 |
1979年 | 109篇 |
1978年 | 71篇 |
1977年 | 87篇 |
1976年 | 65篇 |
1973年 | 64篇 |
1971年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Rishabh Kumar Prachi Kala Geeta S. Narayanan Bhaskar Vishwanathan Sowmya Narayanan Sanjeet Mandal Arpitha Rao Gangadharappa Gowda 《Brachytherapy》2021,20(1):112-117
PURPOSEImage-guided adaptive brachytherapy (IGABT) recently has shown excellent clinical outcomes with superior local control and less toxicity. For IGABT, T2W (T2-weighted) MRI is the gold standard. However, studies have shown that target delineation with the same results in uncertainties, poor interobserver variabilities, and low conformity indices for high-risk clinical target volume contours. In this study, we investigate the role of diffusion-weighted imaging–derived apparent diffusion coefficient (ADC) maps to aid in IGABT. We also evaluated ADC from the baseline to brachytherapy.Methods and MaterialsThirty selected patients were enrolled for this study, and two MRIs were taken at diagnosis and before brachytherapy. Patients were divided into two groups, Group 1 being patients with parametrial involvement before external beam radiotherapy and no parametrial involvement before brachytherapy. Group 2 included patients with parametrial involvement before external beam radiotherapy and persistent parametrial involvement before brachytherapy. ADC was measured at the center, edge, and 1 cm from the edge.ResultsThe measured ADC increased from diagnosis to brachytherapy, and this increase was more for the patients in Group 1 than in Group 2. The mean TDadc (diagnosis ADC, center), TEadc (tumor edge ADC diagnosis), and T1cmDadc (1 cm from edge at diagnosis) were 0.884, 1.45, and 1.9 × 10?3 mm2/s, respectively. The TBadc (ADC at brachytherapy, center), TEBadc (tumor edge ADC at brachytherapy), and TE1cmBadc (1 cm from edge brachytherapy) were 1.2, 1.8, and 2.3 × 10?3 mm2/s, respectively, p-value <0.00001. No abnormal ADC was present outside the high-risk clinical target volume contours.ConclusionMRI-based IGABT using T2W imaging essentially covers all functionally abnormal zones at brachytherapy. Diffusion-weighted imaging, along with ADC maps, should only be used as a supplement for target delineation. 相似文献
992.
993.
Marchina Sarah Pisegna Jessica M. Massaro Joseph M. Langmore Susan E. McVey Courtney Wang Jeffrey Kumar Sandeep 《Journal of neurology》2021,268(1):293-304
Journal of Neurology - Transcranial direct current stimulation (tDCS) has been investigated as a tool for dysphagia recovery after stroke in several single-center randomized controlled trials... 相似文献
994.
Arvind Kumar Deepti Shukla Rashmi Kumar Mohammad Z. Idris Prashant Jauhari Shalini Srivastava Tapan N. Dhole 《Archives of virology》2013,158(1):211-215
We identified and characterized enteroviruses associated with aseptic meningitis in children between April 2009 and March 2010. Enterovirus RNA was detected in 51 (45.5 %) of 112 CSF samples. Molecular typing by RT-PCR and sequencing of a partial VP1 region revealed the predominance of echovirus (ECV) 32 (n = 20), followed by ECV 11 (n = 10), ECV 13 and ECV 14 (n = 5 each), coxsackievirus (CV) B3 and CV B6 (n = 3 each), CV A2, CV A10 and ECV 30 (n = 1 each). Phylogenetic analysis of ECV 32 showed 0 to 4 % sequence divergence among strains of the present study and 20-23 % from the prototype Puerto Rico strain at the nucleotide level. This is the first report of ECV 32 associated with an aseptic meningitis epidemic and identification of seven different enterovirus serotypes (CV A2, CV A10, CV B3, CV B6, ECV 13, ECV 14 and ECV 32) in meningitis cases from India. 相似文献
995.
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
996.
997.
The first step towards detection of valvular heart diseases from heart sound signal (phonocardiogram) is segmentation. A segmentation algorithm provides the location of the first and second heart sounds which in turn helps to locate and analyse the murmur. Established phonocardiogram based segmentation methods use an electrocardiographic (ECG) signal as a continuous auxiliary input in a complex instrumentation setup. This paper proposes an automatic segmentation method that does not require any such auxiliary signal. Compared to other approaches without auxiliary signal, this work extensively utilizes biomedical domain features for reduction of time and computational complexities and is more accurate. The performance of the algorithm is evaluated for nine commonly occurring pathological cases and normal heart sound for various sampling frequencies, recording environments and age group of subjects. The proposed algorithm yields an overall accuracy of 97.47% and is compared with two competing techniques. In addition, the robustness of the algorithm is shown against additive white Gaussian noise contamination at various SNR levels. 相似文献
998.
Tosin Philip Oyetunji S M Yasir Arafat Stephen Oluwaseyi Famori Timilehin Blessing Akinboyewa Michael Afolami Moyo Faith Ajayi Sujita Kumar Kar 《上海精神医学》2021,34(1)
BackgroundSuicide is a global public health problem and Nigeria is one of the epicentres of suicide in the world. However, there is a dearth of research exploring the epidemiological aspects of suicide in Nigeria.AimTo examine the demographic information and precipitating events for suicides in Nigeria by analysing the contents of newspaper reports of suicide.MethodsWe searched, collected, and analysed published news reports about suicide from 10 English newspapers in Nigeria. A total of 350 suicide reports were assessed between January 2010 and December 2019 after screening and sorting.ResultsThe mean (SD) age of the reported cases was 36.33 (15.48) years. Majority of the reported cases were male (80.6%), married (51.8%), students (33.6%), living in a semi-urban area (40.3%) and among the age group of 25–34 (25.3%). Hanging (48.6%) and poisoning (32.2%) were the most commonly reported methods of suicide. Financial constraints and marital conflicts were most commonly assumed precipitating factors.ConclusionThis study suggests that being male, married, or living in semi-urban areas are associated with suicide in Nigeria. Further community-based studies are warranted to generalise the findings and adopt appropriate preventive strategies. 相似文献
999.
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1000.
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