全文获取类型
收费全文 | 2491篇 |
免费 | 326篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 42篇 |
妇产科学 | 38篇 |
基础医学 | 428篇 |
口腔科学 | 26篇 |
临床医学 | 312篇 |
内科学 | 650篇 |
皮肤病学 | 76篇 |
神经病学 | 220篇 |
特种医学 | 78篇 |
外科学 | 301篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 163篇 |
眼科学 | 34篇 |
药学 | 149篇 |
肿瘤学 | 222篇 |
出版年
2022年 | 16篇 |
2021年 | 31篇 |
2020年 | 21篇 |
2019年 | 30篇 |
2018年 | 46篇 |
2017年 | 32篇 |
2016年 | 37篇 |
2015年 | 38篇 |
2014年 | 67篇 |
2013年 | 75篇 |
2012年 | 150篇 |
2011年 | 134篇 |
2010年 | 75篇 |
2009年 | 76篇 |
2008年 | 112篇 |
2007年 | 108篇 |
2006年 | 91篇 |
2005年 | 102篇 |
2004年 | 127篇 |
2003年 | 100篇 |
2002年 | 70篇 |
2001年 | 112篇 |
2000年 | 114篇 |
1999年 | 76篇 |
1998年 | 52篇 |
1997年 | 30篇 |
1996年 | 35篇 |
1995年 | 26篇 |
1994年 | 33篇 |
1993年 | 29篇 |
1992年 | 55篇 |
1991年 | 50篇 |
1990年 | 48篇 |
1989年 | 34篇 |
1988年 | 41篇 |
1987年 | 49篇 |
1986年 | 35篇 |
1985年 | 36篇 |
1984年 | 38篇 |
1983年 | 32篇 |
1982年 | 26篇 |
1981年 | 23篇 |
1980年 | 18篇 |
1979年 | 31篇 |
1978年 | 24篇 |
1977年 | 22篇 |
1973年 | 15篇 |
1968年 | 21篇 |
1967年 | 17篇 |
1966年 | 18篇 |
排序方式: 共有2819条查询结果,搜索用时 15 毫秒
1.
2.
P J Hayden C J Welsh Y Yang W H Schaefer A J Ward J L Stevens 《Chemical research in toxicology》1992,5(2):232-237
Nephrotoxic cysteine conjugates derived from a variety of halogenated alkenes are enzymatically activated via the beta-lyase pathway to yield reactive sulfur-containing metabolites which bind covalently to cellular macromolecules. Mitochondria contain beta-lyase enzymes and are primary targets for binding and toxicity. Previously, mitochondrial protein and/or DNA have been considered as molecular targets for cysteine conjugate metabolite binding. We now report that metabolites of nephrotoxic cysteine conjugates form covalent adducts with rat kidney mitochondrial phospholipids. Rat kidney mitochondria were incubated with the 35S-labeled conjugates S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (TFEC), S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine (CTFC), S-(1,2-dichlorovinyl)-L-cysteine, and S-(1,2,3,4,4-pentachlorobutadienyl)-L-cysteine. Quantitation of metabolite binding to whole mitochondria and to mitochondrial protein and lipid fractions revealed that as much as 42% of the 35S-label associated with the mitochondria was found in the lipid fraction. Total lipids were also extracted from 35S-treated mitochondria and separated by thin-layer chromatography. 35S-Containing metabolites were found in the lipid fractions from mitochondria treated with each of the conjugates. Lipids from both [35S]CTFC- and [35S]-TFEC-treated mitochondria contained major 35S-labeled lipid adducts which had similar mobility by thin-layer chromatography. Fatty acid analysis, 19F and 31P NMR spectroscopy, and mass spectrometric analyses confirmed that the major TFEC and CTFC adducts are thioamides of phosphatidylethanolamine. 相似文献
3.
IC Uluibau Postgraduate Student T. Jaunay Registrar † AN Goss Professor Director ‡ 《Australian dental journal》2005,50(S2):S74-S81
Background : Severe odontogenic infections are serious potentially lethal conditions. Following the death of a patient in the authors' institution this study was initiated to determine the risk factors, management and outcome of a consecutive series of patients.
Methods : All patients admitted to the Royal Adelaide Hospital under the care of the Oral and Maxillofacial Surgery Unit with odontogenic infections in calendar year 2003 were investigated. Detailed information relative to their pre-presentation history, surgical and anaesthetic management and outcome was obtained and analysed.
Results : Forty-eight patients, 32M, 16F, average age 34.5, range 19 to 88 years were treated. All presented with pain and swelling, with 21 (44 per cent) having trismus. Forty-four (92 per cent) were as a result of dental neglect and four (8 per cent) were regular dental patients having endodontic treatment which failed. Of those known to have been treated prior to presentation, most had been on antibiotics. Most patients had aggressive surgical treatment with extraction, surgical drainage, high dose intravenous antibiotics and rehydration. The hospital stay was 3.3 (range 1–16) days. Patients requiring prolonged intubation and high dependency or intensive care (40 per cent) had longer hospitalization. No patient died and all fully recovered.
Conclusion : Severe odontogenic infections are a serious risk to the patient's health and life. Management is primarily surgical with skilled anaesthetic airway management. Antibiotics are required in high intravenous doses as an adjunct and not as a primary treatment. 相似文献
Methods : All patients admitted to the Royal Adelaide Hospital under the care of the Oral and Maxillofacial Surgery Unit with odontogenic infections in calendar year 2003 were investigated. Detailed information relative to their pre-presentation history, surgical and anaesthetic management and outcome was obtained and analysed.
Results : Forty-eight patients, 32M, 16F, average age 34.5, range 19 to 88 years were treated. All presented with pain and swelling, with 21 (44 per cent) having trismus. Forty-four (92 per cent) were as a result of dental neglect and four (8 per cent) were regular dental patients having endodontic treatment which failed. Of those known to have been treated prior to presentation, most had been on antibiotics. Most patients had aggressive surgical treatment with extraction, surgical drainage, high dose intravenous antibiotics and rehydration. The hospital stay was 3.3 (range 1–16) days. Patients requiring prolonged intubation and high dependency or intensive care (40 per cent) had longer hospitalization. No patient died and all fully recovered.
Conclusion : Severe odontogenic infections are a serious risk to the patient's health and life. Management is primarily surgical with skilled anaesthetic airway management. Antibiotics are required in high intravenous doses as an adjunct and not as a primary treatment. 相似文献
4.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence. 相似文献
5.
6.
Maternal serum and amniotic fluid alpha-fetoprotein testing has increased significantly in our laboratory and throughout the state since 1985. The results of this test are reported in a novel fashion as multiples of the median. The calculation and reporting of the test results are highly dependent upon gestational age, maternal weight, race and presence or absence of maternal diabetes. When properly interpreted alpha-fetoprotein determinations are a good screening test for early detection of neural tube defects and Trisomy 21 (Down Syndrome). Our approach to screening, diagnosis and counseling is discussed. 相似文献
7.
Background
Induction of apoptosis is one strategy for treatment of prostate cancer. The Shb adapter protein has been found to regulate apoptosis in various cell types and consequently human prostate cancer 3 (PC3) cells were transfected to obtain cells overexpressing Shb in order to increase our understanding of the mechanisms regulating PC3 cell apoptosis. 相似文献8.
K S Blumenfeld F A Welsh V A Harris M A Pesenson 《Journal of cerebral blood flow and metabolism》1992,12(6):987-995
Cerebral ischemia induces the expression of a number of proteins that may have an important influence on cellular injury. The purpose of this study was to compare the regional effects of hypoxia-ischemia on the expression of the proto-oncogene, c-fos, and the heat shock protein-70 (HSP-70) gene in developing brain. Unilateral hypoxia-ischemia was produced in the brain of immature rats (7, 15, and 23 days after birth) using a combination of carotid artery ligation and systemic hypoxia (8% O2). After recovery for 2 and 24 h, the regional expression of c-fos and HSP-70 mRNA was determined using in situ hybridization. Littermates were permitted to recover for 1 week for assessment of histologic injury. Hypoxia-ischemia increased the expression of both c-fos and HSP-70 mRNA, but the topography of expression varied with the age of the animal as well as the mRNA species. In the 7-day-old group, expression of c-fos at 2 h increased in multiple regions of the ipsilateral hemisphere in nearly one-half of the animals, while HSP-70 mRNA was not expressed until 24 h and, then, predominantly in the hippocampus. In 15- and 23-day-old rats, expression of c-fos was increased at 2 h in the entorhinal cortex and in the dendritic field of the upper blade of the hippocampal dentate gyrus, while HSP-70 mRNA was prominently expressed in neocortex and the cell layers of the hippocampus. Interestingly, the strong expression of HSP-70 mRNA in dentate granule cells did not occur in the innermost layer of cells.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
C A Gaydos L Bobo L Welsh E W Hook R Viscidi T C Quinn 《Sexually transmitted diseases》1992,19(6):303-308
A portion of the major outer membrane protein (MOMP) gene from 15 Chlamydia trachomatis serovars was amplified by polymerase chain reaction (PCR) and the product was analyzed by restriction fragment length polymorphism (RFLP). A set of primers was used to amplify an 871 base pair gene fragment encompassing the 4 hypervariable regions of MOMP. AluI digestion of the product gave distinctive patterns for the 15 serovars as demonstrated on silver-stained polyacrylamide gels. A triple digest with EcoRI, HinfI, and HpaII allowed improved discrimination between closely related serovars (C, H, I, J, L3). PCR and RFLP were used to type 50 wild-type clinical isolates and results were compared to results of the solid-phase enzyme immunoassay typing method. These isolates represented the most prevalent genital serovars (D, E, F, K, I and J) in the local sexually transmitted diseases clinic population. For specimens containing 1 serovar, the results of the two methods were similar for 42 samples and discordant for 1 sample. In addition, two samples showed evidence of mixed infection with two serovars as identified by both methods. Five additional specimens contained two serovars, as shown by one or both methods. In all five such specimens, the two typing methods agreed on at least one of the two serovars. For both single and multiple serovar specimens, there was concordance between the two typing methods for 16/17 E serovars, 8/9 D serovars, 8/8 F serovars, 7/7 I serovars, 7/7 J serovars, 5/8 K serovars, and 0/2 G serovars.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
10.