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131.
We explored the genetic control of cholesterolemic responses to dietary cholesterol and fat in 575 pedigreed baboons. We measured cholesterol in beta-lipoproteins (low density lipoprotein cholesterol [LDLC]) in blood drawn from baboons while they were consuming a baseline (low in cholesterol and fat) diet, a high-saturated fat (lard) diet, and a high-cholesterol, high-saturated fat diet. In addition to baseline levels (LDLC(Base)), we analyzed two variables for diet response: LDLC(RF), which represents the LDLC response to increasing dietary fat (ie, high-fat diet minus baseline), and LDLC(RC), which represents the LDLC response to increasing dietary cholesterol level (ie, high-cholesterol, high-fat diet minus high-fat diet). Heritabilities (h2) of the 3 traits were 0.59 for LDLC(Base), 0.14 for LDLC(RF), and 0.59 for LDLC(RC). In addition, LDLC(Base) and LDLC(RC) had a significant genetic correlation (ie, rhoG=0.54), suggesting that 1 or more genes exert pleiotropic effects on the 2 traits. Segregation analyses detected a single major locus that accounted for nearly all genetic variation in LDLC(RC) and some genetic variation in LDLC(Base) and LDLC(RF) and confirmed the presence of a different major locus that influences LDLC(Base) alone. Preliminary linkage analyses indicated that neither locus was linked to the LDL receptor gene, a likely candidate locus for LDLC. Detection of these major loci with large effects on the LDLC response to dietary cholesterol in a nonhuman primate offers hope of detecting and ultimately identifying similar loci that determine LDLC variation in human populations.  相似文献   
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133.
BACKGROUND: The relationship between circulating levels of angiotensinogen and hypertension in the epidemiologic setting has not been studied much. Recent findings related to the association between hypertension and polymorphisms of the angiotensinogen gene have generated new interest in this potential pathway to hypertension. OBJECTIVES: To examine environmental factors associated with levels of circulating angiotensinogen as determinants of hypertension in populations of African origin. METHODS: We recruited 1557 participants from communities in Nigeria (n = 611), Zimbabwe (n = 161), Jamaica (n = 476), and Maywood, Illinois, USA (n = 309). RESULTS: Mean angiotensinogen levels varied widely across groups (Nigeria 1381 ng/ml angiotensin I generated, Zimbabwe 1638 ng/ml angiotensin I generated, Jamaica 1808 ng/ml angiotensin I generated, and Maywood 2039 ng/ml angiotensin I generated). Average body mass index was highly correlated to angiotensinogen level across the population samples, accounting for 90% of the between-sample variation. At the individual level the correlation between body mass index and angiotensinogen level was substantially smaller, in the range 0.04-0.15, although the association attained statistical significance for all but one of the populations. Women had higher levels of angiotensinogen and mean levels in subjects of both sexes declined in late middle age. Hypertensives also had significantly higher levels of angiotensinogen and we noted correlations to blood pressure for two of the four populations. CONCLUSION: Obesity, sex and age would all appear to be important modifiers of circulating angiotensinogen levels. The variation in level across populations was substantially larger than that which has been found previously in association with known genetic polymorphisms within populations, suggesting the possibility that environmental effects are more important than had previously been recognized.  相似文献   
134.
Polymers have a substantial attention in drug delivery systems owing to the diverse intrinsic advantages. It is important to carry the drug to the target site and release to exert its effects. Herein, poly(p-phenylene)s with amino and poly(ethylene glycol) substituents (PPP-NH2-g-PEG) were used as a carrier for doxorubicin (DOX), an anticancer drug, and haloperidol, a sigma receptor targeting ligand. Both human cervix adenocarcinoma cell line (HeLa) and human keratinocyte cell line (HaCaT) having different Sigma receptor 1 (SigmaR1) expression levels were compared. HeLa was found to express twofold SigmaR1 compared to HaCaT cells. Cell imaging studies showed that, DOX cell uptake was higher in HeLa cells when targeted with haloperidol.  相似文献   
135.
Due to the great interest in oil‐based polymers, which are prepared from renewable resources, different forms and amounts of soybean oil‐based PLA films were prepared and evaluated for their potential usage as a medical biomaterial. Soybean oil, epoxidized soybean oil and auto‐oxidized soybean oil were blended with PLA and PLA/oil films with appropriate oil amounts [2, 7, 14 and 20% (w/w)] were obtained by solvent casting. Thermal stability and plasticization effect were determined by adjusting oil amounts and type. Epoxidized soybean oil blended films showed the smallest increase in elongation breaks (13–20%) and the highest decrease in thermal decomposition temperatures (364–327 °C) compared to other oil blended films. In vitro quantitative and qualitative cytotoxicity results showed no reactivity (grade 0) for the L929 cells treated with 14% (w/w) oil blended PLA films. In vivo irritation and implantation tests concluded that 14% (w/w) oil blended PLA films were non‐irritant. No erythema, no oedema reactions, no traumatic necrosis and foreign debris were observed. Thus, along with superior biocompatibility, PLA/oil films can replace petroleum‐based products for several biomedical uses.  相似文献   
136.
Performance measurements of 30 mammographic installations were carried out in order to see the current level of image quality and breast doses.The half of the systems tested in this survey indicated automatic exposure control and beam collimation problems. Film processing and dark room conditions were not optimum for the majority of the installations. Image quality phantoms were exposed by the user and team of the survey at each visited center. Lower breast doses were obtained at equal image qualities for the radiographs of the team indicating the importance of adequate handling of some exposure parameters. Corrective actions were suggested to each installation and necessary guidance was advised for the implementation of routine quality control activities.  相似文献   
137.
<正>正如本期前文所述,土耳其建筑的现代化可以追溯到20世纪初。但是,它的产业化是近期才发生的。特别是,在土耳其,从"湿作业(现场浇注)"到"干作业(预制构件)"的施工系统转变仅仅发生在20年前。第一批在形式上使用现代施工技术的建筑出现在20世纪初。1960年代,钢筋混凝土框架结构才逐步成为土耳其全国最普遍的结构体系。  相似文献   
138.
A series of well-defined amphiphilic graft copolymers with hydrophobic polysulfone (PSU) as backbones and hydrophilic poly(ethylene glycol) (PEG) as side chains were synthesized and characterized. For this purpose, PSUs were converted to azido-functionalized polymers by successive chloromethylation and azidation processes to give clickable PSUs. Then, the ω-hydroxyl function of the commercially available PEG-OH was converted into propargyl functionality by simple esterification process. Ultimately, the alkyne functionalized PEO was successfully grafted onto the PSUs by click chemistry. The final polymers and intermediates at various stages were characterized by 1H NMR, FT-IR, and GPC techniques. The bioinert character of PEG grafted PSU was confirmed by static protein adsorption and prokaryotic and eukaryotic cell adhesion studies, and compared to that of unmodified PSU.  相似文献   
139.
An inhibition based biosensing system was developed for the caffeic acid as lipoxygenase (LOX) inhibitor. LOX was immobilized in carbon paste electrode and the amperometric detection of hydroperoxy linoleic acid due to the enzymatic reaction using linoleic acid as a substrate was monitored at +0.9 V versus Ag/AgCl. The decrease in biosensor response in the presence of caffeic acid was found to be correlated with the inhibitor concentration. Diode array detector and LOX biosensor was used as an electrochemical detector for the analysis of this compound. All data were given as a comparison of two systems.  相似文献   
140.
Color is an indispensible characteristic of food because it makes foods easily recognizable and attractive in our modern society. Numerous food colors have been removed from the national and international lists of ??accepted food colors?? due to their mutagenic and carcinogenic activities based on a number of toxicity studies that have been conducted since food colors were first identified as carcinogenic by researchers. This study investigated the changes in oxidative stress parameters such as glutathione (GSH), malondialdehyde (MDA), glutathione peroxidase (GPx) activity, and catalase (CAT) activity that occurred when Chinese hamster ovary (CHO) cells were exposed to Tartrazine (CAS No. 1934-21-0) and New Coccin (CAS No. 2611-82-7), commonly-used azo dyes in the food industry. It was found that intracellular GSH significantly decreased, MDA levels increased, and GPx and CAT levels remained the same, (as compared to the control), when CHO cells were exposed to these food colors. Based on our results, Tartrazine and New Coccin food colors can be regarded as toxic. Considering the possible oxidative damage induced by these food colors, due to the depletion of GSH (a cell??s major antioxidant), and a significant increase in MDA levels, we strongly believe that the use of these potentially toxic colors in food needs to be reconsidered.  相似文献   
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