全文获取类型
收费全文 | 846篇 |
免费 | 36篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 81篇 |
妇产科学 | 29篇 |
基础医学 | 141篇 |
口腔科学 | 13篇 |
临床医学 | 66篇 |
内科学 | 129篇 |
皮肤病学 | 14篇 |
神经病学 | 59篇 |
特种医学 | 17篇 |
外科学 | 90篇 |
综合类 | 16篇 |
预防医学 | 72篇 |
眼科学 | 19篇 |
药学 | 92篇 |
中国医学 | 3篇 |
肿瘤学 | 36篇 |
出版年
2022年 | 13篇 |
2021年 | 15篇 |
2020年 | 9篇 |
2019年 | 16篇 |
2018年 | 22篇 |
2017年 | 13篇 |
2016年 | 25篇 |
2015年 | 32篇 |
2014年 | 40篇 |
2013年 | 46篇 |
2012年 | 90篇 |
2011年 | 94篇 |
2010年 | 45篇 |
2009年 | 29篇 |
2008年 | 46篇 |
2007年 | 52篇 |
2006年 | 52篇 |
2005年 | 47篇 |
2004年 | 40篇 |
2003年 | 30篇 |
2002年 | 34篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 11篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1965年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有887条查询结果,搜索用时 15 毫秒
11.
Saroj Gupta Rakesh Kumar Bidani Shashi Jhamb Mahendra Kumar Agarwal 《The Journal of asthma》1996,33(5):339-348
The etiological significance of animal danders in Indian patients with nasobronchial disorders has not yet been investigated. In the present study, the role of animal danders in the etiology of bronchial asthma was studied. Extracts of danders from 6 animals along with guinea pig whole pelt were prepared. Intradermal and bronchial provocation tests with these extracts were performed on (i) 68 asthmatics and (ii) 20 nonallergic healthy volunteers. In patients, significant positive skin reactions (2+ to 4+) ranged from 1.4% each with guinea pig whole pelt and ox dander to 8.8% with dog dander extracts. None of the healthy volunteers elicited such a response. On bronchial provocation, 20% and 53.8% of the tests were positive in asthmatics showing 1 +and 2+skin reactivity, respectively. All the patients as well as controls eliciting negative intradermal responses demonstrated uniformly negative bronchial provocation tests to different dander extracts. Analysis of various clinical features of asthmatics with respect to skin positivity to dander/pelt extract was also carried out. Radioallergosorbent tests (RASTs) were performed to estimate dander-specific IgE levels in the sera of patients showing different grades of skin response to dander extracts of dog, horse, and goat. Sixty percent of sera from the patients showing 2+ to 4+ skin reactivity to various animal dander extracts showed positive RASTs. RAST positivity as well as RAST ratio increased with increase in the intensity of skin response. All the patients with positive cutaneous as well as positive bronchial responses also showed positive RASTs. Similarly, all the patients with positive skin and positive RASTs showed positive bronchoprovocation tests. These results suggested that animal danders play an important role in the etiology of bronchial asthma. Some of the clinical characteristics of asthmatics, such as (i) early age at onset of asthma, (ii) positive family history, and (iii) asthma with associated allergies, have significant bearing on the cutaneous response to various dander extracts. 相似文献
12.
Virender J. Lamba Shashi V. Goswami Bangalore I. Sundararaj 《General and comparative endocrinology》1983,50(2):205-225
Circannual and circadian variations in plasma levels of steroids were estimated by radioimmunoassay in the female and male catfish, Heteropneustes fossilis, over two consecutive annual reproductive cycles. In the female catfish, testosterone (T), estradiol-17β (E2), and estrone (E1) were detectable in the plasma only during the reproductively active (preparatory through spawning) period and their levels increased during vitellogenesis. In the fully gravid catfish, when vitellogenesis was nearly complete, levels of E2 declined but those of T continued to increase suggesting a product-precursor relationship between the two steroids. Plasma cortisol (F) was detectable throughout the year and exhibited three peaks coinciding with summer, monsoon, and winter; the first and second peaks coincided with vitellogenesis and spawning, respectively. In the male catfish, changes in plasma T and F levels closely paralleled the seasonal recrudescence and activity of testes and seminal vesicles. After spawning, gonads regressed and levels of sex steroids declined sharply. In the absence of natural spawning due to scanty monsoon rains, as during the second year of this study, gonadal regression was delayed and the sex steroids persisted in the plasma well beyond the normal spawning season. In addition, the first two peaks of F levels merged to form a plateau extending from the preparatory period until the late spawning period. The three sex steroids (T, E2, and E1) exhibited identical circadian rhythms; a major peak occurred at the onset of the dark phase (20:00 hr) and a minor peak was generally observed 4 hr after the onset of the light phase (12:00 hr). The amplitude of rhythms was greatest during the prespawning and the spawning periods. Cortisol peak levels generally alternated with those of sex steroids. Steroid rhythms show rather precise correlations with environmental factors such as photoperiod, temperature, and rainfall as well as with seasonal reproductive activity in both sexes of catfish. 相似文献
13.
Aloe vera affects changes induced in pulmonary tissue of mice caused by cigarette smoke inhalation
下载免费PDF全文
![点击此处可从《Environmental toxicology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
This study was undertaken to determine the influence of Aloe vera (AV) on changes induced in pulmonary tissue of cigarette smoke (CS) inhaling mice. CS inhalation for 4 weeks caused pulmonary damage as evident by histoarchitectural alterations and enhanced serum and tissue lactate dehydrogenase (LDH) activities. CS inhalation also led to increased mucin production as revealed by mucicarmine and Alcian Blue‐Periodic Acid Schiff (AB‐PAS) staining. Studies on bronchoalveolar lavage fluid (balf) of CS exposed animals revealed structural changes in phospholipids and increase in surface tension when compared with control counterparts. These changes were accompanied by enhanced nitric oxide (NO) levels, citrulline levels, peroxidative damage, and differential modulation of antioxidant defense system. AV administration (seven weeks, 500 mg/kg b.w. daily) to CS inhaling mice led to modulation of CS induced pulmonary changes as revealed by lesser degree of histoarchitectural alterations, lesser mucin production, decreased NO levels, citrulline levels, peroxidative damage, and serum LDH activity. AV treatment to CS inhaling mice was associated with varying response to antioxidant defense system, however balf of CS + AV treated animals did not exhibit appreciable changes when compared with that of CS exposed animals. These observations suggest that AV has the potential to modulate CS induced changes in the pulmonary tissue which could have implications in management of CS associated pulmonary diseases, however, further investigations are required to explore its complete mechanism of action. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 999–1013, 2015. 相似文献
14.
This article proposes a strategy for primary care providers to begin treating patients with hepatitis C virus (HCV). We are motivated by the need to expand HCV treatment and by developments that have simplified treatment for most patients. This article presents 5 steps to achieving quality HCV treatment in the primary care setting: (1) accurate diagnosis via reflex testing; (2) risk stratification and identifying comorbidities via pretreatment evaluation; (3) simple, once-daily, pan-genotypic HCV treatment regimens; (4) minimized on-treatment monitoring: and (5) posttreatment monitoring and high-quality care for comorbidities such as cirrhosis and injection drug use. We provide indications for referral to specialists: notably children, patients with genotype 3 and cirrhosis, advanced liver or kidney disease, previous treatment failures, drug interactions with recommended regimens, and hepatitis B co-infection. Finally, potential barriers for providers are discussed, as well as further research findings and policy interventions that can promote HCV treatment in the primary care setting. We believe that a substantial portion of patients with HCV can be treated safely and effectively by nonspecialists and that the engagement of primary care providers is critical to efforts to end the HCV epidemic. 相似文献
15.
Kusal K. Das Jameel G. Jargar Sikha Saha Saeed M. Yendigeri Shashi Bala Singh 《Indian journal of pharmacology》2015,47(3):285-291
Objective:Lead (Pb) is a long-known poison of environment and industrial origin. Its prolonged exposure affects cellular material and alters cellular genetics and produces oxidative damages. In this study, we investigated the exposure of chronic sustained hypoxia or lead acetate alone or in combination with or without supplementation of α-tocopherol on hepatic oxidative and nitrosative stress in rats.Results:Exposure of both lead and hypoxia showed decreased body weight, altered serum lipid profile, oxidant and enzymatic antioxidants status, serum HIF-1α and VEGF concentrations. Simultaneous α-tocopherol supplementation showed beneficial effects to all these alterations. Histopathological observations also showed hepatic degenerative changes after lead or hypoxia exposure either alone or in combination, but remarkable improvement has been noticed after α-tocopherol supplementation.Conclusion:Supplementation of α-tocopherol is beneficial to counter both lead acetate and hypoxia induced hepatic cytotoxicities possibly by reducing oxidative and nitrosative stress.KEY WORDS: α-tocopherol, hypoxia, lead acetate, nitrosative stress, oxidative stress 相似文献
16.
17.
18.
Arvind Jina Michael J. Tierney Janet A. Tamada Scott McGill Shashi Desai Beelee Chua Anna Chang Mark Christiansen 《Journal of diabetes science and technology》2014,8(3):483-487
The development of accurate, minimally invasive continuous glucose monitoring (CGM) devices has been the subject of much work by several groups, as it is believed that a less invasive and more user-friendly device will result in greater adoption of CGM by persons with insulin-dependent diabetes. This article presents the results of preliminary clinical studies in subjects with diabetes of a novel prototype microneedle-based continuous glucose monitor. In this device, an array of tiny hollow microneedles is applied into the epidermis from where glucose in interstitial fluid (ISF) is transported via passive diffusion to an amperometric glucose sensor external to the body. Comparison of 1396 paired device glucose measurements and fingerstick blood glucose readings for up to 72-hour wear in 10 diabetic subjects shows the device to be accurate and well tolerated by the subjects. Overall mean absolute relative difference (MARD) is 15% with 98.4% of paired points in the A+B region of the Clarke error grid. The prototype device has demonstrated clinically accurate glucose readings over 72 hours, the first time a microneedle-based device has achieved such performance. 相似文献
19.
Arora A Acharya SR Muliya VS Sharma P 《Quintessence international (Berlin, Germany : 1985)》2012,43(3):187-190
Multiple idiopathic cervical resorption is an uncommon condition, the etiology of which remains unknown. The case of a 36-year-old woman with idiopathic resorption in the cervical areas of multiple teeth is presented. Her medical history was noncontributory, but her dental history was valuable in reaching a diagnosis. Hematologic and endocrinal investigations were unremarkable, but a computed tomography scan revealed relevant information. The progression of the lesion and involvement of multiple teeth without any pattern or chronology are challenges faced when diagnosing and treating this condition. 相似文献
20.