首页 | 官方网站   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   18641篇
  免费   1118篇
  国内免费   136篇
医药卫生   19895篇
  2024年   30篇
  2023年   246篇
  2022年   685篇
  2021年   1070篇
  2020年   705篇
  2019年   849篇
  2018年   1008篇
  2017年   713篇
  2016年   772篇
  2015年   781篇
  2014年   1046篇
  2013年   1205篇
  2012年   1642篇
  2011年   1690篇
  2010年   998篇
  2009年   762篇
  2008年   1108篇
  2007年   984篇
  2006年   828篇
  2005年   704篇
  2004年   554篇
  2003年   454篇
  2002年   389篇
  2001年   48篇
  2000年   58篇
  1999年   58篇
  1998年   50篇
  1997年   44篇
  1996年   43篇
  1995年   35篇
  1994年   18篇
  1993年   33篇
  1992年   24篇
  1991年   17篇
  1990年   19篇
  1989年   20篇
  1988年   17篇
  1987年   10篇
  1986年   13篇
  1985年   12篇
  1984年   19篇
  1983年   17篇
  1982年   16篇
  1981年   11篇
  1980年   12篇
  1979年   13篇
  1978年   10篇
  1976年   10篇
  1974年   8篇
  1973年   7篇
排序方式: 共有10000条查询结果,搜索用时 4 毫秒
101.
102.
The transdermal delivery of buspirone hydrochloride across hairless mouse skin and the combined effect of iontophoresis and terpene enhancers were evaluated in vitro using Franz diffusion cells. Iontophoretic delivery was optimized by evaluating the effect of drug concentration, current density, and pH of the vehicle solution. Increasing the current density from 0.05 to 0.1 mA/cm2 resulted in doubling of the iontophoretic flux of buspirone hydrochloride, while increasing drug concentration from 1% to 2% had no effect on flux. Using phosphate buffer to adjust the pH of the drug solution decreased the buspirone hydrochloride iontophoretic flux relative to water solutions. Incorporating buspirone hydrochloride into ethanol:water (50:50 vol/vol) based gel formulations using carboxymethylcellulose and hydroxypropylmethylcellulose had no effect on iontophoretic delivery. Incorporation of three terpene enhancers (menthol, cineole, and terpineol) into the gel and when combined with iontophoresis it was possible to deliver 10 mg/cm2/day of buspirone hydrochloride.  相似文献   
103.
1 BACKGROUNDTheincidenceofCPis 0 .7per 1 0 0 0livebirths[1 ] .Becausecerebralpalsyinfluencesthewaychildrendevelop,itoftenresultsindevelop mentaldisability .Today ,more peoplehavecerebralpalsythananyotherdevelopmentaldis ability ,includingDownsyndrome,epilepsy ,andautism .Accordingtoasurveyconductedin1 986,2 .6%ofthepopulationofPakistaniaredisabled (includingbothphysicalandmentaldis abilities) .Childrenbetween 0~1 4 yearsinageconstitute 40 %ofthedisabled populationinPakistan .Routineme…  相似文献   
104.
PURPOSE: To describe a randomized trial of a cognitive behavioral intervention on reducing symptom severity among patients diagnosed with solid tumors and undergoing a first course of chemotherapy and to determine whether the intervention had an additive or interactive effect on symptom severity in the presence of supportive care medications. PATIENTS AND METHODS: Patients (N = 237) were accrued from comprehensive and community cancer centers, interviewed, and randomly assigned to either the experimental intervention (n = 118) or conventional care (n = 119). A symptom severity index, based on summed severity scores across 15 symptoms, was the primary outcome. Each patient's site of cancer, stage at diagnosis, chemotherapy protocols, and use of supportive medications were learned from medical records. RESULTS: Groups were equivalent at baseline, and attrition by characteristics by group was not different. The proportion of patients not receiving chemotherapy at 10 and 20 weeks did not differ by group. At the 10- and 20-week observations, there was a significant interaction between the experimental group and baseline symptom severity. Patients in the experimental group who entered the trial with higher symptom severity reported significantly lower severity at 10 and 20 weeks. Controlling for chemotherapy treatment status at follow-up and supportive care medications did not alter the effect of the experimental intervention. CONCLUSION: Compared with conventional care alone, the experimental intervention was effective among patients who entered the trial with higher levels of symptom severity. Age, sex, site or stage of cancer, and supportive medications did not modify the effect of this cognitive behavioral intervention on symptom severity.  相似文献   
105.
We have previously reported that XK469 (2-[4-(7-chloro-2-quinoxalinyloxyphenoxy]-propionic acid) enhances topo IIalpha expression in WSU-WM cells in vitro [E. Mensah-Osman et al., Mol. Cancer Ther., 1: 1321-1326, 2002]. To test the hypothesis that XK469-induced expression of topo IIalpha sensitizes WSU-WM cells to the topo IIalpha inhibitor etoposide (VP-16), we investigated the antitumor effects of XK469 and VP-16 in vivo, using the WSU-WM SCID xenograft model. Individual dosages of XK469 at 20-60 mg/kg/injection i.v. for a maximum-tolerated dose of 240 mg/kg were achievable in SCID mice. Simultaneous administration of a subtherapeutic dose of XK469 (20 mg/kg) and VP-16 at its maximum-tolerated dose of 15 mg/kg proved to be highly toxic and lethal. However, daily sequential treatment of XK469 given i.v. via tail vein at 20 mg/kg for a total of 120 mg/kg, followed 7 h later by VP-16 i.p. at 15 mg/kg for a total of 90 mg/kg, had no significant toxicity in SCID mice. The sequential treatment was associated with enhanced antitumor activity. Tumor growth inhibition T/C, tumor growth delay T-C, and log(10) kill for XK469 alone were 61%, 3 days and 0.46; VP-16 alone 6%, 12 days and 1.83, respectively; whereas the sequential administration of both agents gave a T/C value of 0%, T-C value of 23 days and a log(10) kill of 3.5. On the basis of these animal results, we conclude that the sequential treatment of WSU-WM tumors with XK469 and VP-16 was highly active. The study supports our in vitro observation that XK469 potentiates VP-16 activity. The sequential use of both agents resulted in clinically significant antitumor activity in the WM model.  相似文献   
106.
This article tests the hypothesis that anthropometrical outcomes in preschool children are a function of complex interaction between food, nutrition, health, and other physical environmental conditions within which children live and grow. A system of simultaneous equations is used to test the above hypothesis using data from an Ethiopian highland community. The results show that a child's nutritional and health status are jointly determined by dietary intake, well-being of the mother as the primary caregiver, and the state of the physical environment for agricultural production and healthy living. Among other factors, children were found to be in better health with an increase in the number of cows in their households' livestock herds. The revealed interrelatedness and complexities of cause and effect clearly dictate the need for a multi- or transdisciplinary approach to research and development addressing health, nutrition, sanitation, agricultural production practices, among other factors for alleviating the nutritional and health problems of children and rural households.  相似文献   
107.
There have been conflicting reports as to whether olanzapine produces lower occupancy of striatal dopamine D(2)/D(3) receptor than typical antipsychotic drugs and preferential occupancy of extrastriatal dopamine D(2)/D(3) receptors. We performed [(18)F] fallypride PET studies in six schizophrenic subjects treated with olanzapine and six schizophrenic subjects treated with haloperidol to examine the occupancy of striatal and extrastriatal dopamine receptors by these antipsychotic drugs. [(18)F] setoperone PET studies were performed in seven olanzapine-treated subjects to determine 5-HT(2A) receptor occupancy. Occupancy of dopamine D(2)/D(3) receptors by olanzapine was not significantly different from that seen with haloperidol in the putamen, ventral striatum, medial thalamus, amygdala, or temporal cortex, that is, 67.5-78.2% occupancy; olanzapine produced no preferential occupancy of dopamine D(2)/D(3) receptors in the ventral striatum, medial thalamus, amygdala, or temporal cortex. There was, however, significantly lower occupancy of substantia nigra/VTA dopamine D(2)/D(3) receptors in olanzapine-treated compared to haloperidol-treated subjects, that is, 40.2 vs 59.3% (p=0.0014, corrected for multiple comparisons); in olanzapine-treated subjects, the substantia nigra/VTA was the only region with significantly lower dopamine D(2)/D(3) receptor occupancy than the putamen, that is, 40.2 vs 69.2% (p<0.001, corrected for multiple comparison). Occupancy of 5-HT(2A) receptors was 85-93% in the olanzapine- treated subjects. The results of this study demonstrated that olanzapine does not produce preferential occupancy of extrastriatal dopamine D(2)/D(3) receptors but does spare substantia nigra/VTA receptors. Sparing of substantia nigra/VTA dopamine D(2)/D(3) receptor occupancy may contribute to the low incidence of extrapyramidal side effects in olanzapine-treated patients.  相似文献   
108.
PURPOSE: Aberrant promoter hypermethylation of several known or putative tumor suppressor genes occurs frequently during the pathogenesis of prostate cancers and is a promising marker for cancer detection. We sought to develop a test for prostate cancer based on a quantitative methylation-specific polymerase chain reaction (QMSP) of multiple genes in urine sediment DNA. PATIENTS AND METHODS: We tested urine sediment DNA for aberrant methylation of nine gene promoters (p16INK4a, p14(ARF), MGMT, GSTP1, RARbeta2, CDH1 [E-cadherin], TIMP3, Rassf1A, and APC) from 52 patients with prostate cancer and 21 matched primary tumors by quantitative fluorogenic real-time polymerase chain reaction. We also analyzed urine sediments from 91 age-matched individuals without any history of genitourinary malignancy as controls. RESULTS: Promoter hypermethylation of at least one of the genes studied was detected in urine samples from all 52 prostate cancer patients. Urine samples from the 91 controls without evidence of genitourinary cancer revealed no methylation of the p16, ARF, MGMT, and GSTP1 gene promoters, whereas methylation of RARbeta2, TIMP3, CDH1, Rassf1A, and APC was detected at low levels. CONCLUSION: Overall, methylation found in urine samples matched the methylation status in the primary tumor. A combination of only four genes (p16, ARF, MGMT, and GSTP1) would theoretically allow us to detect 87% of prostate cancers with 100% specificity. Our data support further development of the noninvasive QMSP assay in urine DNA for early detection and surveillance of prostate cancer.  相似文献   
109.
Traditional Persian medicine (TPM) proposes a different viewpoint to the chronic diseases. Diagnosis and implemented treatment are based on individual differences among patients. Constipation or Ea''teghal-e-batn is a condition in which the patient develops difficult or painful defecation. Based on TPM concepts, the first digestion step starts from halq (oral cavity), and ends via defecation from the maq''ad (anus). Avicenna believed that four faculties, ha''zemeh (digestive), ja''zebeh (absorptive), ma''sekeh (retentive) and da''fe''eh (propulsive), are involved in the process of digestion and absorption of the ingested food and expelling the waste materials. The bowel movement and appearance of the stool is a measure for evaluating the gastrointestinal healthy function. Defecation should be with no pain and fecal material should have no burning and acuity. Low food intake or foods with dry temperament, dryness of gastrointestinal tract, diaphoresis and heavy exercise as well as intestine sensory loss were discussed as main causes of constipation. Management of constipation in TPM includes dietary schemes, oil massages and subsequently simple herbal medicines. According to TPM theories, the first step in treating a disease is the elimination of disease causes (asbab e-maraz) and also providing the causes of health (asbab-e-sehhat). Health care providers should know the proper condition which the herbal medicines should be administered in and be able to guide the patients about the benefits and hazards of herbal remedies, commonly used in their living origin.  相似文献   
110.
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-23

京公网安备 11010802026262号