首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   320篇
  免费   20篇
耳鼻咽喉   2篇
儿科学   16篇
妇产科学   15篇
基础医学   38篇
口腔科学   19篇
临床医学   31篇
内科学   42篇
皮肤病学   4篇
神经病学   15篇
特种医学   26篇
外科学   20篇
综合类   13篇
预防医学   25篇
眼科学   14篇
药学   34篇
中国医学   1篇
肿瘤学   25篇
  2023年   1篇
  2022年   5篇
  2021年   13篇
  2020年   8篇
  2019年   3篇
  2018年   12篇
  2017年   10篇
  2016年   11篇
  2015年   15篇
  2014年   12篇
  2013年   20篇
  2012年   45篇
  2011年   40篇
  2010年   22篇
  2009年   14篇
  2008年   17篇
  2007年   14篇
  2006年   12篇
  2005年   14篇
  2004年   11篇
  2003年   10篇
  2002年   6篇
  2001年   5篇
  2000年   5篇
  1999年   3篇
  1998年   2篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1986年   1篇
  1985年   1篇
排序方式: 共有340条查询结果,搜索用时 46 毫秒
21.
We studied the maternal and neonatal profile and outcome of extremely low birth weight (ELBW) babies at the level III neonatal intensive care unit (NICU) in Delhi. Case records of ELBW inborn babies delivered between August 2000 and August 2001 were analysed by using a pre-set proforma. A total of 52 ELBW babies were admitted to the NICU in the relevant period, of whom 30 (57%) survived. Maternal anaemia, previous preterm delivery and pregnancy-induced hypertension (PIH) were the common predisposing factors for preterm delivery. Mean gestational age was 27.8 weeks and mean birth weight was 831 g. The highest mortality (55%) was seen in babies with 26-28 weeks'gestation and those in the birth weight category of < 800 g. Neonatal hyperbilirubinaemia (78%) and hyaline membrane disease/respiratory distress syndrome (65%) were the most common causes of morbidity. A total of 25 babies were mechanically ventilated while 24 (46%) received total parenteral nutrition. Sepsis, pulmonary haemorrhage, intracranial haemorrhage and necrotizing enterocolitis accounted for the deaths in the study population. Retinopathy of prematurity screening was performed in 35 babies (68%), of whom 22 were found to be normal. According to the International Classification of Retinopathy of Prematurity, most babies (72%) had involvement of zone 3 and stage I (63%). The incidence was highest in 26-28 weeks'gestation babies (71%) and the < 800 g birth weight category (62%). Maternal risk factors such as anaemia and PIH commonly predispose to preterm delivery. There is an alarmingly high mortality in this population. Effective steps are required not only to avoid extreme prematurity but also to reduce morbidity and mortality of all newborns weighing <1000 g at birth.  相似文献   
22.
OBJECTIVES: The reasons for the very low incidence of the disease neurolathyrism in humans even after excessive consumption of the pulse, Lathyrus sativus, under severe drought and famine conditions, and its continued consumption by large populations during normal periods without any deleterious effects have been examined in the context of a possible metabolism or detoxification of beta-N-oxalyl-L-alpha, beta-diaminopropionic acid (ODAP), the major neurotoxic amino acid of L. sativus. DESIGN AND METHODS: ODAP in urine samples from 54 subjects habitually consuming the pulse and in three volunteers on an L. sativus diet was determined by the OPT method following clean up of the samples on an alumina column. Urinary oxalate was also determined in these individuals. RESULTS: Twenty-five subjects showed no excretion of ODAP and it was only less than 0.7% of the dietary intake in the remaining 29 subjects. Urinary excretion of ODAP in three volunteers was also less than 1% with a peak excretion in the 4-h sample. The 4-h blood sample from one volunteer had a maximum ODAP concentration of 177 microM. The urinary oxalate content in the volunteers was nearly 3-fold higher compared to controls. CONCLUSIONS: The low excretion of dietary ingested ODAP in humans is in sharp contrast to that seen in animals and indicates a metabolism or detoxification of ODAP which may be unique to humans and may explain the low incidence of neurolathyrism.  相似文献   
23.
The antioxidant enzymes like catalase and superoxide dismutase (SOD) were studied in erythrocytes and lens at various stages of cataractogenesis in albino rats. The rate of peroxidation was measured by assessing the malondiadehyde (MDA) in lens and plasma. The insoluble and soluble protein fractions were measured in lens to study the protein crosslinkings in relation to the above said parameters. Cataract was induced in albino rats by feeding it with 30% galactose as part of the normal diet (w/w) for 30 days. The results show a decrease of SOD and catalase with concomitant increase of MDA and insoluble protein with the advancement of cataract.  相似文献   
24.
Changes in glucose-6-phosphate dehydrogenase (G-6-PD), glutathione reductase (GSH-R), reduced glutathione (GSH), glutathione peroxidase (GSH-PO), transketolase (TK) and transaldolase (TA) were studied in lens and red blood cells (RBCs) to understand the possible biochemical mechanisms responsible for the development of senile cataract. The activity of G-6-PD was increased in lens, though not so in erythrocytes during cataractogenesis. A marked decrease was observed in GSH level and GSH-R activity in the lens and RBCs of the cataractous group. The activity of GSH-PO was remarkably high in lens but not in the erythrocytes during the maturity of cataract. The activity of TK decreased gradually in both the lens and erythrocytes. The activity of TA decreased in erythrocytes but increased in the lens with maturation of cataract.  相似文献   
25.
Metarrhizium anisopliae is a common pathogen of insects and has even been used to control insect populations. It is rarely isolated from human or animal sources, but recently, there have been three reported cases of disease, two in humans and one in a cat. We present our experience with five isolates from human sources, including two that were the apparent causes of two cases of sinusitis in immunocompetent hosts. The first patient was a 36-year-old male with frontal and ethmoid sinusitis, and the second was a 79-year-old female with chronic sinusitis. Both patients underwent surgery, and pathology of the surgical specimens revealed branching hyphae. Cultures grew only Metarrhizium species. Neither patient received antifungal therapy, and both did well postoperatively. The other three isolates were cultured from bronchoalveolar lavage specimens but were not felt to be clinically significant. Antifungal susceptibility testing using the National Committee for Clinical Laboratory Standards macrobroth method revealed that all isolates were resistant to amphotericin B, 5-flucytosine, and fluconazole. Itraconazole and newer azole compounds were more active. Metarrhizium species may cause disease in humans, even those without evidence of immunosuppression, and are apparently highly resistant to amphotericin B in vitro.  相似文献   
26.
KIR (Killer Immunoglobulin‐like Receptor) variants influence immune responses and are genetic factors in disease susceptibility. Using sequence‐specific priming PCR, we have previously described the diversity of KIR genes in term of presence/absence in northeastern Thais (NETs). To provide additional resolution beyond conventional methods, quantitative PCR was applied to determine KIR copy number profiles. Novel expanded and contracted KIR copy number profiles were identified at cumulatively high frequencies. These all comprise haplotypes with duplication (6·9%) or deletion (2·7%) of KIR3DL1/S1 along with adjacent genes. Five expanded KIR profiles comprised haplotypes with duplications of KIR2DP1, 2DL1, 3DP1, 2DL4, 3DL1/S1 and 2DS1/4, whereas two contracted profiles contained only a single copy of KIR3DP1, 3DL1/S1 and 2DL4. Using a KIR haplotype prediction program (KIR Haplotype Identifier), 14% of NET haplotypes carried atypical haplotypes based on the gene copy number data.  相似文献   
27.
Summary Haloperidol is a widely used neuroleptic drug for the treatment of acute and chronic psychosis. The use of haloperidol is limited by extrapyramidal movement disorders such as Parkinsonism, akathesia, dystonia, and tardive dyskinesia (TD). Treatment with haloperidol increases oxyradicals which are implicated in TD. Spirulina is widely used as nutritional supplement rich in proteins and antioxidants. The present study is proposed to study the effect of spirulina on haloperidol induced TD and oxidative stress by studying TD, various enzymatic and nonenzymatic antioxidants and lipid peroxidation. Haloperidol 1 mg/kg/i.p was used to induce vacuous chewing movements in rats. Spirulina maxima suspended in 1% between 80 at a dose of 45, 90 and 180 mg/kg were administered by gavage along with haloperidol from 21st day to 49th day of treatment. Spirulina supplementation at a dose of 180 mg/kg significantly improved enzymatic and nonenzymatic antioxidants and decreased the tardive dyskinesia induced by haloperidol. In conclusion, the results of present investigation suggest that spirulina decreases haloperidol induced oxidative stress and TD by many mechanisms as it is cocktail of antioxidants. On chronic use it may inhibit haloperidol induced reduced expression of DNA thereby increases the expression of enzymatic and nonenzymatic antioxidants and protects against oxidative stress induced neurodegeneration and TD.  相似文献   
28.
29.
30.
Incidental Lewy body disease (ILBD) is the term used when Lewy bodies are found in the nervous system of subjects without clinically documented parkinsonism or dementia. The prevalence of ILBD in the elderly population has been estimated at between 3.8 and 30%, depending on subject age and anatomical site of sampling. It has been speculated that ILBD represents the preclinical stage of Parkinson’s disease (PD) and/or dementia with Lewy bodies (DLB). Studies of ILBD could potentially identify early diagnostic signs of these disorders. At present, however, it is impossible to know whether ILBD is a precursor to PD or DLB or is just a benign finding of normal aging. We hypothesized that, if ILBD represents an early stage of PD or DLB, it should be associated with depletion of striatal dopaminergic markers. Eleven subjects with ILBD and 27 control subjects were studied. The ILBD subjects ranged in age from 74 to 96 years (mean 86.5) while the control subjects’ age ranged from 75 to 102 years (mean 86.7). Controls and subjects did not differ in terms of age, postmortem interval, gender distribution, medical history conditions, brain weight, neuritic plaque density or Braak neurofibrillary stage. Quantitative ELISA measurement of striatal tyrosine hydroxylase (TH), the principal enzyme for dopamine synthesis, showed a 49.8% (P = 0.01) reduction in ILBD cases, as compared with control cases. The finding suggests that ILBD is not a benign condition but is likely a precursor to PD and/or DLB.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号