全文获取类型
收费全文 | 1588篇 |
免费 | 84篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 53篇 |
妇产科学 | 29篇 |
基础医学 | 164篇 |
口腔科学 | 11篇 |
临床医学 | 127篇 |
内科学 | 451篇 |
皮肤病学 | 17篇 |
神经病学 | 114篇 |
特种医学 | 54篇 |
外科学 | 133篇 |
综合类 | 26篇 |
预防医学 | 112篇 |
眼科学 | 78篇 |
药学 | 138篇 |
中国医学 | 15篇 |
肿瘤学 | 138篇 |
出版年
2023年 | 8篇 |
2022年 | 31篇 |
2021年 | 63篇 |
2020年 | 28篇 |
2019年 | 31篇 |
2018年 | 49篇 |
2017年 | 30篇 |
2016年 | 29篇 |
2015年 | 38篇 |
2014年 | 72篇 |
2013年 | 74篇 |
2012年 | 126篇 |
2011年 | 114篇 |
2010年 | 81篇 |
2009年 | 46篇 |
2008年 | 81篇 |
2007年 | 79篇 |
2006年 | 66篇 |
2005年 | 70篇 |
2004年 | 51篇 |
2003年 | 37篇 |
2002年 | 36篇 |
2001年 | 27篇 |
2000年 | 24篇 |
1999年 | 30篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 12篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 27篇 |
1991年 | 22篇 |
1990年 | 17篇 |
1989年 | 14篇 |
1988年 | 13篇 |
1987年 | 18篇 |
1986年 | 20篇 |
1985年 | 13篇 |
1984年 | 13篇 |
1983年 | 8篇 |
1979年 | 10篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1973年 | 11篇 |
1972年 | 7篇 |
1968年 | 9篇 |
1967年 | 6篇 |
1966年 | 7篇 |
1965年 | 6篇 |
排序方式: 共有1675条查询结果,搜索用时 15 毫秒
1.
Seethalakshmi Viswanathan Naveen Chawla Anil D’Cruz Shubhada V. Kane 《Head and neck pathology》2007,1(2):169-172
Histoplasmosis is a rarely reported deep mycotic infection in the Indian context. Oral or oropharyngeal manifestation can
occur as an isolated symptom or as part of a disseminated process associated with immunosuppression especially with HIV and
diabetes. Five cases of head and neck histoplasmosis accrued over 6 years in a tertiary referral cancer institute were reviewed.
All these patients presented clinically as cancer. In three patients, the marked pseudoepitheliomatous hyperplasia led to
a mistaken biopsy diagnosis of malignancy following which definitive surgical treatment was performed. The subsequent excision
revealed typical features of histoplasmosis. Isolated oral presentation of histoplasmosis can mimic malignancy both clinically
as well as pathologically, leading to potentially disastrous consequences. A high index of suspicion in those with overt or
hidden immunosuppression and a deep wedge biopsy to demonstrate the organisms in the subepithelial tissue is recommended.
This work has been presented in the “Slide seminar on Infections and Infestations” in the IAP-ID pre conference CME in APCON
2006. 相似文献
2.
Varadharaj S Watkins T Cardounel AJ Garcia JG Zweier JL Kuppusamy P Natarajan V Parinandi NL 《Antioxidants & redox signaling》2005,7(1-2):287-300
Recent clinical trials have shown that vitamin C, at pharmacological concentrations (milligram to approximately gram), upon infusion into circulation, modulates vasodilation and vascular tone in humans. This also results in the elevated concentrations of vitamin C in circulation in the millimolar range. Here, it was hypothesized that vitamin C at pharmacological concentrations (millimolar) would induce oxidative stress and cause loss of redox-dependent cell viability in vascular endothelial cells (ECs). To test the hypothesis, bovine lung microvascular ECs (BLMVECs) in monolayer cultures were exposed to vitamin C (0-10 mM) for different time periods (0-2 h). Electron paramagnetic resonance spectroscopy revealed the intracellular formation of ascorbate free radical in a dose- and time-dependent fashion. Vitamin C also induced formation of intracellular reactive oxygen species in a dose-dependent fashion. It was observed that vitamin C induced morphological alterations and loss of cell viability in a dose- and time-dependent fashion, as measured by light microscopy and Alamar Blue redox cell viability assay, respectively. Vitamin C analogues failed to induce such changes. Vitamin C depleted cellular GSH levels in a dose-dependent fashion, suggesting that vitamin C altered thiol-redox status in BLMVECs. Antioxidants, intracellular iron chelator, and catalase protected cells against vitamin C-induced loss of redox-dependent cell viability, confirming the role of hydrogen peroxide and iron during redox cycling of vitamin C. These results, for the first time in detail, established that vitamin C at pharmacological doses induced oxidative stress and loss of redox-dependent cell viability in microvascular ECs. 相似文献
3.
4.
Mutants in a conserved region near the carboxy-terminus of HIV-1 Rev identify functionally important residues and exhibit a dominant negative phenotype 总被引:19,自引:0,他引:19
The rev protein (Rev) of human immunodeficiency virus increases the cytoplasmic expression of viral structural gene mRNAs. We had previously reported the existence of a region (residues 73-98) near the carboxy-terminus in HIV-1 Rev essential for its function. To further define the structural elements in this region, we examined the effects of substitution mutations in highly conserved residues in this region, between amino acids 75-81, on Rev function. Mutations in Pro76-77 and Arg80 retained Rev function, whereas those in Leu75 and Leu81 abolished Rev activity and exhibited trans-dominant suppression of wt Rev function. The Leu81 mutation, in particular, exhibited an efficient dominant negative phenotype. Leu75 and Leu81 thus appear to define residues essential to the Rev "effector" function. 相似文献
5.
Recent research has revealed that the health care of India's rural population is being provided by private practitioners. With as many as 1,250,000 private practitioners providing health services to at least half of India's population, three studies were conducted to shed light on the profile and practice of the private practitioners. It was found that the private practitioners are almost always male, practice in or close to their birthplace, and have attended school. Only 25% are graduates, however, and almost 50% have no formal training. Regardless of training, nearly 90% practice allopathy. In a study of 542 patients, no physical examinations were conducted in 47% of the cases, but the patients were satisfied with the care they received because the private practitioners paid more attention to them than they were accustomed to receive from primary health care doctors. The private practitioners are compensated by adding a surcharge to the fee for medicines. The patients believe that they are simply purchasing medications. This system requires the practitioners to dispense medications, injections, or both to receive compensation. Medications, including antibiotics, are given in small doses (a practice which is certainly harmful). The practitioners refer difficult cases to the government centers. Most of the practitioner, however, practice alone, with their only professional contact being the town chemist. Almost all of these practitioners expressed interest in joining an association. Analysis of the cost of this health care shows that it accounts for a substantial portion of rural expenditure and constitutes a sizeable hidden "industry." In order to respond to this situation, the government must either ban the untrained rural private practitioner, promote the quality of care provided by the government network, or acknowledge the existence of the private practitioners and provide them with support and training. 相似文献
6.
Chittukadu Kesavan Gajalakshmi Sundaram Krishnamurthi Revathy Ananth Viswanathan Shanta 《Cancer causes & control : CCC》1996,7(5):520-524
Uterine cervical cancer is the most common malignancy among females in developing countries, including India. The success of cervical cancer screening programs in North America and Western Europe has been the result of centralized cervical-cytology screening. This is not possible in the villages (n=17,000) of Tamilnadu where 58 percent of females in rural areas are illiterate, health infrastructure is mediocre, and cervical cytology is unknow. The present study was undertaken to examine if the village health nurse (VHN) could be trained quickly to identify a cervical abnormality by visual inspection so that we could down stage the cancer to earlier stages, more amenable to treatment. VHNs also would be trained to take an adequate Pap smear. A total of 101 VHNs were trained in batches and returned to their villages. Within two years, 6,459 engible women in the study area were screened. The agreement between the gynecologists and the VHNs in identifying cancer among those with abnormal cervix was 95 percent, and 80 percent of the Pap smears taken by VHNs were adequate by WHO criteria, making the feasibility study highly successful.Authors are with The Cancer Institute (WIA), Adyar, Madras, Tamil Nadu,India. Address correspondence to Dr Gajalakshmi, Epidemiology Division and Cancer Registry, 18, Sardar Patel Road, Cancer Institute (WIA), Madras-600 036, Tamilnadu, India. This project was funded by the Indian Council of Medical Research, Government of India, New Delhi, India.520 Cancer Causes and Control. Vol 7. 1996 相似文献
7.
Anticarcinogenic effect of bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione a curcumin analog on DMH-induced colon cancer model. 总被引:3,自引:0,他引:3
T Devasena K N Rajasekaran G Gunasekaran P Viswanathan Venugopal P Menon 《Pharmacological research》2003,47(2):133-140
1,2-Dimethylhydrazine (DMH) is a toxic environmental pollutant which was reported also to be a colon-specific carcinogen. This study was performed to study the effect of bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione, a bisdemethoxycurcumin analog (BDMC-A) on DMH-induced colon carcinogenesis in male Wistar rats and effects were compared with that of the reference drug, curcumin. Rats were given a weekly subcutaneous injection of DMH (20mg/kg body weight) in the groin, for 15 weeks. After a total experimental period of 32 weeks (including 2 weeks of acclimatization) tumor incidence was 100% in DMH-treated rats. Tumor was identified histologically as adenocarcinoma. Dysplasia, papillary pattern, cellular pleomorphism and carcinomatous glands were also noticed in DMH-treated rats. However, there was no colonic tumor in DMH+BDMC-A- and DMH+curcumin-treated rats but, lymphocyte infiltrations were observed. The levels of total bile acids and cholesterol in 24h fecal samples were significantly lower in DMH administered rats when compared to control rats, while, the excretion of bile acids and cholesterol were significantly increased and was near normal levels in DMH+BDMC-A- and DMH+curcumin-treated rats. In DMH-induced tumor bearing rats the levels of colonic and intestinal cholesterol was significantly increased whereas, the levels of phospholipid was decreased with a concomitant increase in the activities of phospholipase A (PLA) and phospholipase C (PLC), compared to untreated control rats. Intragastric administration of BDMC-A and curcumin to DMH administered rats significantly lowered the cholesterol content and raised the phospholipid content and lowered the activities of PLA and PLC towards near normal values. Our study shows that the protective effect of BDMC-A during DMH-induced colon carcinogenesis may be due to its modulatory effects on (i). histological changes, (ii). bile acids, (iii). cholesterol, and (iv). phospholipid metabolism in the target organ. Absence of histological changes in the colon of rats treated with BDMC-A, shows that long term administration of BDMC-A is nontoxic to experimental animals. Our study suggest that BDMC-A may emerge as a potent anticarcinogenic agent against colon cancer. As both BDMC-A and curcumin are equipotent in inhibiting the DMH-induced colon tumor incidence and normalizing histological changes, it could be concluded that the terminal phenolic group and the conjugated double bonds in the central seven carbon change may be responsible for the beneficial effects. 相似文献
8.
Chittukadu K. Gajalakshmi Viswanathan Shanta Ranganathan Rama 《Cancer causes & control : CCC》1998,9(2):131-136
Objectives: This study was carried out to evolve a method to improve the registration of cancer mortality data in Chennai (Madras, India). Methods: Data on cancer deaths have been collected from the Vital Statistics Department (VSD) by a population-based cancer registry (PBCR) in Chennai only since 1982. The low mortality-to-incidence ratio during 1982-84 suggested under-registration of mortality data. Since 1985, the PBCR has taken special effort to ascertain the vital status of cancer cases by sending reply-paid postcards and/or making house visits. The data on all deaths occurring in Chennai, irrespective of stated cause of death in the death certificate, have been collected from the VSD since 1992. Results: Deaths that occurred in Chennai and obtained by sending reply-paid postcards and/or making house visits were registered in VSD as non-cancer causes of death; hence, these data were not collected from VSD. The sensitivity and positive predictive values of death certificates on cancer diagnosis based on 1992 and 1993 mortality data were 57 percent and 99.5 percent, respectively. Conclusion: Since the accuracy of death certificate information on cancer diagnosis is relatively low in a developing country such as in India, collecting data on all deaths will improve the mortality data registration in PBCRs. 相似文献
9.
Roy Kakali Satapathy Amit Kumar Houhton Jayne A. L. Flanagan Sarah E. Radha Venkatesan Mohan Viswanathan Sharma Rajni Jain Vandana 《Indian journal of pediatrics》2019,86(11):1051-1053
Indian Journal of Pediatrics - Congenital hyperinsulinism (CHI) is a clinically and genetically heterogeneous disorder, characterized by dysregulated insulin secretion. Pathogenic variants in at... 相似文献
10.
Asmau Iyabo Balogun Eswaran Padmanabhan Firas Ayad Abdulkareem Haylay Tsegab Gebretsadik Cecilia Devi Wilfred Hassan Soleimani Prasanna Mohan Viswanathan Boon Siong Wee Jemilat Yetunde Yusuf 《Materials》2022,15(23)
A novel technique was employed to optimize the CO2 sorption performance of spent shale at elevated pressure–temperature (PT) conditions. Four samples of spent shale prepared from the pyrolysis of oil shale under an anoxic condition were further modified with diethylenetriamine (DETA) and ethylenediamine (EDA) through the impregnation technique to investigate the variations in their physicochemical characteristics and sorption performance. The textural and structural properties of the DETA- and EDA- modified samples revealed a decrease in the surface area from tens of m2/g to a unit of m2/g due to the amine group dispersing into the available pores, but the pore sizes drastically increased to macropores and led to the creation of micropores. The N–H and C–N bonds of amine noticed on the modified samples exhibit remarkable affinity for CO2 sequestration and are confirmed to be thermally stable at higher temperatures by thermogravimetric (TG) analysis. Furthermore, the maximum sorption capacity of the spent shale increased by about 100% with the DETA modification, and the equilibrium isotherm analyses confirmed the sorption performance to support heterogenous sorption in conjunction with both monolayer and multilayer coverage since they agreed with the Sips, Toth, Langmuir, and Freundlich models. The sorption kinetics confirm that the sorption process is not limited to diffusion, and both physisorption and chemisorption have also occurred. Furthermore, the heat of enthalpy reveals an endothermic reaction observed between the CO2 and amine-modified samples as a result of the chemical bond, which will require more energy to break down. This investigation reveals that optimization of spent shale with amine functional groups can enhance its sorption behavior and the amine-modified spent shale can be a promising sorbent for CO2 sequestration from impure steams of the natural gas. 相似文献