全文获取类型
收费全文 | 4700篇 |
免费 | 239篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 203篇 |
妇产科学 | 70篇 |
基础医学 | 546篇 |
口腔科学 | 346篇 |
临床医学 | 331篇 |
内科学 | 697篇 |
皮肤病学 | 82篇 |
神经病学 | 246篇 |
特种医学 | 95篇 |
外科学 | 911篇 |
综合类 | 85篇 |
一般理论 | 4篇 |
预防医学 | 199篇 |
眼科学 | 140篇 |
药学 | 584篇 |
1篇 | |
中国医学 | 38篇 |
肿瘤学 | 325篇 |
出版年
2023年 | 42篇 |
2022年 | 101篇 |
2021年 | 178篇 |
2020年 | 104篇 |
2019年 | 130篇 |
2018年 | 166篇 |
2017年 | 129篇 |
2016年 | 154篇 |
2015年 | 165篇 |
2014年 | 197篇 |
2013年 | 289篇 |
2012年 | 419篇 |
2011年 | 437篇 |
2010年 | 200篇 |
2009年 | 204篇 |
2008年 | 250篇 |
2007年 | 234篇 |
2006年 | 185篇 |
2005年 | 147篇 |
2004年 | 140篇 |
2003年 | 123篇 |
2002年 | 127篇 |
2001年 | 67篇 |
2000年 | 47篇 |
1999年 | 51篇 |
1998年 | 23篇 |
1997年 | 17篇 |
1996年 | 26篇 |
1995年 | 18篇 |
1993年 | 11篇 |
1992年 | 49篇 |
1991年 | 44篇 |
1990年 | 44篇 |
1989年 | 42篇 |
1988年 | 29篇 |
1987年 | 39篇 |
1986年 | 27篇 |
1985年 | 25篇 |
1984年 | 25篇 |
1983年 | 25篇 |
1981年 | 17篇 |
1980年 | 10篇 |
1979年 | 15篇 |
1978年 | 10篇 |
1977年 | 17篇 |
1976年 | 16篇 |
1975年 | 14篇 |
1974年 | 24篇 |
1973年 | 13篇 |
1972年 | 11篇 |
排序方式: 共有4945条查询结果,搜索用时 15 毫秒
71.
H L Komiskey J F Bossart D D Miller P N Patil 《Proceedings of the National Academy of Sciences of the United States of America》1978,75(6):2641-2643
Tritiated dopamine was used to label the dopamine receptor in membranes isolated from the rat corpus striatum. Scatchard analysis of displacement of [3H]dopamine by nonradioactive dopamine indicated the presence of two binding sites. The similarities in affinity, capacity, and drug specificity of the high-affinity site in the striatal membranes from rat and the binding site in the membranes from the calf caudate nucleus suggest that [3H]dopamine labels the same site in both species. In order to determine what conformation of dopamine is preferred at the dopamine receptor site, conformationally restricted analogs of dopamine--namely, the cis and trans 2-amino-1(3,4-dihydroxyphenyl)cyclobutane hydrochlorides--were tested for their affinity to the receptor. Compared to the cis conformation, the trans-restricted analogs had more affinity for the receptor site, indicating that dopamine probably interacts with the receptor in the trans conformation. 相似文献
72.
Ransalu Senanayake Errol R. Hoffmann Ravindra S. Goonetilleke 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2013,231(3):367-379
Current models for targeted-tracking are discussed and shown to be inadequate as a means of understanding the combined task of tracking, as in the Drury’s paradigm, and having a final target to be aimed at, as in the Fitts’ paradigm. It is shown that the task has to be split into components that are, in general, performed sequentially and have a movement time component dependent on the difficulty of the individual component of the task. In some cases, the task time may be controlled by the Fitts’ task difficulty, and in others, it may be dominated by the Drury’s task difficulty. Based on an experiment carried out that captured movement time in combinations of visually controlled and ballistic movements, a model for movement time in targeted-tracking was developed. 相似文献
73.
74.
Bhushan B. Kulkarni Shivaprakash V. Hiremath Suyamindra S. Kulkarni Umesh R. Hallikeri Basavaraj R. Patil Pramod B. Gai 《Journal of virological methods》2013
The identification of the etiology of breast cancer is a crucial research issue for the development of an effective preventive and treatment strategies. Researchers are exploring the possible involvement of Mouse Mammary Tumor Virus (MMTV) in causing human breast cancer. Hence, it becomes very important to use a consistent positive control agent in PCR amplification based detection of MMTV-Like Sequence (MMTV-LS) in human breast cancer for accurate and reproducible results. This study was done to investigate the feasibility of using genomic DNA of MCF-7 breast cancer cells to detect MMTV-LS using PCR amplification based detection. MMTV env and SAG gene located at the 3′ long terminal repeat (LTR) sequences were targeted for the PCR based detection. No amplification was observed in case of the genomic DNA of MCF-7 breast cancer cells. However, the 2.7 kb DNA fragment comprising MMTV env and SAG LTR sequences yielded the products of desired size. From these results it can be concluded that Genomic DNA of MCF-7 cell is not a suitable choice as positive control for PCR or RT-PCR based detection of MMTV-LS. It is also suggested that plasmids containing the cloned genes or sequences of MMTV be used as positive control for detection of MMTV-LS. 相似文献
75.
CABARKAPA Sonja Sadhu Raja King Joel Dowling Nathan Radhakrishnan Raghavakurup Akinbiyi Akinsola Srinivasaraju Ravindra Stevenson Dean 《The Psychiatric quarterly》2021,92(1):229-237
Psychiatric Quarterly - Patients who abscond from acute inpatient psychiatric wards put themselves and others at risks of variable nature and severity. There is a limited understanding of what... 相似文献
76.
Ganesh B. Patil Sanjay J. Surana 《Journal of biomaterials science. Polymer edition》2013,24(15):1740-1756
Ropinirole hydrochloride (RPN), a nonergot dopamine D2-agonist used in the management of Parkinson’s disease, has poor oral bioavailability (52%) due to extensive hepatic metabolism. The intent of present research work was aimed at design and statistical optimization of RPN-loaded poly (lactic-co-glycolic acid) (PLGA)-based biodegradable nanoparticles (NPs) surface modified using natural emulsifier, vitamin E (d-α-tocopheryl polyethylene glycol 1000 succinate [TPGS]) for direct nose-to-brain delivery in order to avoid hepatic first-pass metabolism, and improve therapeutic efficacy with sustained drug release. RPN-NPs were prepared by modified nanoprecipitation technique and optimized using 23 factorial design of experiment. The effect of polymer and emulsifier concentration was evaluated on particle size and entrapment efficiency (EE%). Formulation PL6 was considered as desirable with highest EE% (72.3?±?6.1%), PS (279.4?±?1.8?nm), zeta potential (?29.4?±?2.6?mV), and cumulative drug diffusion of 96.43?±?3.1% in 24?h. The ANOVA results for the dependent variables demonstrated that the model was significant (p value?<?0.05) for response variables. Histopathological study of optimized batch (PL6) demonstrated good retention of NPs with no severe signs of damage on the integrity of nasal mucosa. Differential scanning calorimetry revealed the absence of any chemical interaction between RPN, PLGA, and TPGS while SEM study confirmed spherical shape of optimized NPs. Accelerated stability studies of freeze-dried optimized batch demonstrated negligible change in the average PS and EE% after storage at 25?±?2?°C/60?±?5% (relative humidity (RH) for the period of three months. The promising results of optimized batch suggested practicability of investigated system for enhancement of bioavailability and brain targeting of CNS acting drugs like RPN. 相似文献
77.
Sahil Sood Lavanya Gurram Dheera Aravindakshan John Paul Supriya Chopra Jamema Swamidas Akshay Patil Umesh Mahantshetty 《Brachytherapy》2021,20(3):550-556
PurposeThe study is an audit of reporting dose and volume specifications as per the ICRU 58 for MUPIT-based interstitial brachytherapy in gynecological cancers. Correlation between total reference air kerma (TRAK) and isodose surface was also evaluated to understand the intensity of treatment in interstitial brachytherapy.Methods and MaterialsForty-two patients underwent HDR MUPIT-based interstitial brachytherapy 20 Gy in five fractions after EBRT during 2017–2019. Treated volume, high and low-dose regions, mean central dose, Dose Homogeneity Index (DHI), organ at risk doses, and TRAK values were computed.ResultsHigh-dose regions V150 mean was 12.4 cc and V200 was 4.58 cc; and low-dose region was 75.92 cc. The mean treated volume was 59.8 cc. The mean central dose was 3.7 Gy. DHI was 79%. The mean D2cm3 bladder and rectum were 2.9 Gy and 2.8 Gy. The mean TRAK was 0.16 cGy per fraction per hour at 1 m. TRAK values showed significant correlation with various isodose volumes (TRAK and V100: r = 0.943 p < 0.0005; and TRAK and V50: r = 0.953; p < 0.0005). A positive correlation was observed between TRAK and the number of needles (r = 0.746; p < 0.0005). At a median followup of 16 months, 4 of 42 patients (9.5%) had local recurrences.ConclusionsOur study shows compliance with ICRU 58 recommendations along with certain deviations. Local recurrence rate is acceptable. TRAK shows correlation with surface isodose in MUPIT-based brachytherapy and should to be evaluated in future studies. 相似文献
78.
Prasanna Mithra Prithvishree Ravindra B Unnikrishnan T Rekha Tanuj Kanchan Nithin Kumar Mohan Papanna Vaman Kulkarni Ramesh Holla K Divyavaraprasad 《Indian Journal of Palliative Care》2013,19(2):83-87
Background:
Organ transplantation is the most preferred treatment modality for end-stage organ diseases. The need for the transplants is higher than the availability. Prerequisites for the success of transplantation program include awareness and positive attitudes.Aim:
To assess the perceptions and attitudes of the people seeking health care in tertiary care centers towards organ donation in Mangalore, India.Settings and Design:
This cross-sectional study included 863 people seeking general healthcare as outpatients.Materials and Methods:
Face to face interviews were carried out using pretested tools which included the socio demographic data. Data was analyzed using Statistical Package for Social Sciences version 11.5.Results:
Overall, 59.6% participants showed the willingness to donate organs. Females (64.1%) and participants from upper socio economic status (62.7%) had higher willingness rates for organ donations. Hindus (63.6%) and Christians (63.3%) had higher willingness rates for organ donations than Muslims (38.2%). Also, 23.7% participants showed willingness to donate eyes and 33.6% wished to donate any organ after death. Most of the participants (67%) were aware that money should not be accepted for donating organs, and 58.1% were aware that it is an offence to accept any benefit for organ donations. Forty percent participants had perceived risks associated with organ donation. Regarding donor cards, 42.3% of the participants knew about it and 3.7% already possessed it.Conclusion:
It is apparent from the study that though there was high level of awareness about organ donation, a high proportion of the participants did not have positive attitudes towards organ donation. 相似文献79.
Purpose
The aim of the study was to assess the distribution of accessory foramina in the mandibular body with computed tomography (CT).Materials and methods
The CT images of the mandibular body in 300 subjects (183 females and 117 males aged between 12 and 85 years) were retrospectively analysed for the presence of accessory foramina. The buccal and lingual surfaces were examined by dividing them into anterior and posterior quadrants.Results
Of the 300 subjects, 26 presented with accessory foramina on buccal posterior aspect and 70 subjects presented on buccal anterior aspect. Further, on the lingual posterior aspect, 132 subjects presented with accessory foramina and 59 subjects presented on lingual anterior aspect. Most of the subjects with accessory foramina in the buccal posterior, buccal anterior and lingual anterior regions had accessory foramina on other aspects of the mandible as well.Conclusion
A substantial number of subjects presented with accessory foramina on the lingual posterior aspect when compared to other aspects. Nevertheless, the number of subjects with accessory foramina on other aspects of the mandible was considerable and cannot be ignored. It is suggested that when an accessory foramen is identified in an individual on a particular aspect of the mandibular body, it is highly probable that he will exhibit accessory foramina on other aspects as well. 相似文献80.
Vadlamudi Tharanath Kaldis Athanasios Divi Venkataramana Sai Gopal Patil Basavaprabhu L. Voloudakis Andreas E. 《Virus genes》2021,57(5):469-473
Virus Genes - Citrus yellow mosaic badnavirus (CMBV) causes mosaic disease in all economically important citrus cultivars of India, with losses reaching up to 70%. CMBV belongs to the genus... 相似文献