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101.
The effects of not breastfeeding on mortality due to diarrhea and acute lower respiratory infection (ALRI) in children under 2 years of age were examined using data from a 1988-1991 longitudinal study of 9,942 children in Metro Cebu, The Philippines. Cox regression methods were used to study the magnitude of the risks, possible interactions with birth weight and nutritional status, and the effect of additional confounding factors. Not breastfeeding had a greater effect on diarrheal mortality than on ALRI mortality. In the first 6 months of life, failing to initiate breastfeeding or ceasing to breastfeed resulted in an 8- to 10-fold increase in the rate of diarrheal mortality. The rate of mortality associated with both ALRI and diarrhea was increased nearly six times by not breastfeeding, but the rate of ALRI mortality alone was not increased. The data also suggested that the risk of mortality associated with not breastfeeding was greater for low birth weight infants and infants whose mothers had little formal education. After age 6 months, the protective effects of breastfeeding dropped dramatically. These findings underscore the importance of promoting breastfeeding, especially during the first 6 months of life, and of targeting high risk groups such as low birth weight babies and those of low socioeconomic status. 相似文献
102.
Smith Marilyn C.; MacLeod Colin M.; Bain John D.; Hoppe Richard B. 《Canadian Metallurgical Quarterly》1989,15(6):1109
Two experiments examined priming in the lexical decision task, an indirect test of memory. Experiment 1 manipulated type of processing during study of unrelated word pairs. Recognition of individual words benefited more from semantic than from nonsemantic processing. Repetition priming in lexical decision depended on the context in which the target appeared. Targets preceded at test by unstudied primes showed greater repetition priming if processed nonsemantically during study; targets preceded at test by studied primes were not affected by type of processing at study. Interestingly, studied targets were facilitated more by studied than by unstudied primes regardless of whether the prime came from the same pair as the target. This list-wide episodic priming occurred under all four processing conditions in Experiment 1 (consonant counting, rote rehearsal, pleasantness rating, and sentence generation) with a 250-ms stimulus onset asynchrony. Experiment 2 showed that this list-wide episodic priming disappeared by 1,000 ms, suggesting that it had resulted from relatively transient activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
103.
104.
Edward?V.?BongioEmail author Hamilton?Black Fabienne?C.?Raszewski Doreen?Edwards Caspar?J.?McConville Vasantha?R.?W.?Amarakoon 《Journal of Electroceramics》2005,14(3):193-198
Strontium-doped lanthanum ferrites (LSF) were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), 4-point D.C. electrical conductivity and bulk property measurements. The results were compared to those of previous studies as well as selected processing conditions. The investigation focused on effects of sintering temperature, time, atmosphere (air, O2 and N2) and composition of La1–xSrxFeO3– (x = 0.2–0.9), on the sintering behavior, microstructural development and electrical conductivity. An oxalate precipitation method was used to prepare lanthanum ferrite powders. Simultaneous thermogravimetric and differential thermal analysis (TGA/DTA) studies found calcination temperatures of 800 and 850^C were necessary to form single-phase crystalline powders, as determined by XRD. Specimens were sintered from 1300 to 1400^C with dwell times from
to 2 hrs. Results from SEM/EDS analysis showed the presence of a second phase in the samples fired in air or oxygen. The second phase was not detected by x-ray diffraction due to the small amount of material present. Samples fired in nitrogen had the lowest conductivity while those fired in oxygen had the highest. A composition of x = 0.5 resulted in the highest conductivity, 352 S/cm, at an operating temperature of 550C in air. High strontium additions (x = 0.9) lowered the linear shrinkage of LSF. 相似文献
105.
Scope: Phenethyl isothiocyanate (PEITC) is a constituent of cruciferous vegetables that has demonstrated cancer preventive activity in a number of cancer models including lung, prostate, and breast cancer. Our objective was to examine the effects of the oral administration of PEITC for 7 days on the hepatic expression of genes important in drug metabolism and toxicity in Sprague Dawley rats. The liver is the major site for the metabolism of various xenobiotics and carcinogens, and determining the effects of PEITC on the gene expression of hepatic enzymes may provide insight into mechanisms underlying the cancer preventive activity of PEITC. Methods and results: Using a microarray containing 282 genes, we observed that PEITC significantly up‐regulated UDP‐glucuronosyltransferase UGT1A6 and strongly down‐regulated nicotinamide N‐methyltransferase (NNMT). We also confirmed the down‐regulation of NNMT by real‐time quantitative RT‐PCR. Other genes that were significantly up‐regulated were the drug metabolizing enzyme cyp2b15, the anti‐apoptotic gene bcl2l2, and the stress regulators Gadd45b, Dnajb9, Dnajb5 and Hspb1. Conclusion: Our results indicate new targets that may be important in the mechanisms of the anticancer effects of PEITC. Of particular significance was the down‐regulation of NNMT which may represent a new target for the treatment of a variety of cancers. 相似文献
106.
M. Walsh J.N. Pritchard A. Black S.R. Moores A. Morgan 《Journal of aerosol science》1980,11(5-6):467-474
A system is described for the administration of plutonium oxide aerosols to mice in order to study the pathological effects in the lung. Included are details of(a) the technique for preparation and classification of the bulk material, (b) apparatus for the administration of the aerosol by nose-only exposure and (c) the facility in which such exposures may safely be performed. 相似文献
107.
Marilyn Arosemena Farah A. Meah Kieren J. Mather Sarah A. Tersey Raghavendra G. Mirmira 《International journal of molecular sciences》2021,22(4)
Type 2 diabetes (T2D) typically occurs in the setting of obesity and insulin resistance, where hyperglycemia is associated with decreased pancreatic β-cell mass and function. Loss of β-cell mass has variably been attributed to β-cell dedifferentiation and/or death. In recent years, it has been proposed that circulating epigenetically modified DNA fragments arising from β cells might be able to report on the potential occurrence of β-cell death in diabetes. Here, we review published literature of DNA-based β-cell death biomarkers that have been evaluated in human cohorts of islet transplantation, type 1 diabetes, and obesity and type 2 diabetes. In addition, we provide new data on the applicability of one of these biomarkers (cell free unmethylated INS DNA) in adult cohorts across a spectrum from obesity to T2D, in which no significant differences were observed, and compare these findings to those previously published in youth cohorts where differences were observed. Our analysis of the literature and our own data suggest that β-cell death may occur in subsets of individuals with obesity and T2D, however a more sensitive method or refined study designs are needed to provide better alignment of sampling with disease progression events. 相似文献
108.
Doubly oriented specimens of high density polyethylene (HDPE), nylon 66 and poly(ethylene terephthalate) (PET) were re-stretched along a direction perpendicular to the molecular chain axis at temperatures ranging between room temperature and the respective polymer melting points. Brittle failure was observed for PE samples at all the test temperatures with no significant amount of plastic deformation; whereas, for both PET and nylon 66 samples, ductile deformation was observed at elevated temperatures with plastic strain of >400%. The ductile deformation of nylon 66 and PET occurred with an anisotropic change in the cross-sectional dimensions of the specimen, the reduction taking place predominantly in only one lateral direction. The morphological change accompanying the drawing of the doubly oriented PET and nylon 66 material was examined by using X-ray and optical methods. The implications of the difference in deformation behaviour with respect to the morphological differences among oriented PE, PET and nylon 66 materials are discussed. 相似文献
109.
Loss of fluorescence from cis-parinaric acid (cPnA) is a sensitive indicator of lipid peroxidation. The purpose of this study was to utilize cPnA to determine,
at the level of the intact immune cell, whether enrichment of membranes with polyunsaturated fatty acids (PUFA) increased
lipid peroxidation. P388D1 macrophages were labeled by addition of cPnA as an ethanolic solution. Within two minutes of addition,
in the absence of serum, cPnA rapidly intercalated into the plasma membrane. Lipid peroxidation was initiated by addition
of Fe2+-EDTA resulting in a dose-dependent decrease in fluorescence with increased oxidant concentration. Cells previously enriched
with PUFA and labeled by intercalation showed no differences in spontaneous or Fe2+-induced lipid peroxidation. In separate experiments, 20 μM cPnA in ethanolic solution was injected into cell culture media
containing 0.1% essentially fatty acid free bovine serum albumin (BSA). Cells were resuspended and incubated for 90 min at
37°C. After washing with BSA to remove cPnA which had not incorporated, 0.5% (0.1 μM) of the added cPnA was found esterified
within cellular lipids. This level of cPnA provided a 100-fold increase over basal autofluorescence levels. Cells labeled
in this manner also lost fluorescence in a dose-dependent manner as levels of oxidant stress increased. Cells enriched with
PUFA and labeled by esterification had significantly increased rates and total amounts of lipid peroxidation. Co-incubation
with α-tocopherol and PUFA resulted in a decrease in lipid peroxidation which was not significantly different from control
cells. In conclusion, esterification of cPnA into membrane phospholipids can sensitively detect changes in lipid peroxidation
induced by alteration of membrane PUFA and/or vitamin E content.
Presented in part at the Experimental Biology Meetings, Anaheim, California, April 1994.
Contribution from the Missouri Agriculture Extention Station, Journal #12,495. 相似文献
110.
Hui Ding Rameshwar Patil Jose Portilla-Arias Keith L. Black Julia Y. Ljubimova Eggehard Holler 《International journal of molecular sciences》2015,16(4):8607-8620
Multifunctional polymer nanoconjugates containing multiple components show great promise in cancer therapy, but in most cases complete analysis of each component is difficult. Polymalic acid (PMLA) based nanoconjugates have demonstrated successful brain and breast cancer treatment. They consist of multiple components including targeting antibodies, Morpholino antisense oligonucleotides (AONs), and endosome escape moieties. The component analysis of PMLA nanoconjugates is extremely difficult using conventional spectrometry and HPLC method. Taking advantage of the nature of polyester of PMLA, which can be cleaved by ammonium hydroxide, we describe a method to analyze the content of antibody and AON within nanoconjugates simultaneously using SEC-HPLC by selectively cleaving the PMLA backbone. The selected cleavage conditions only degrade PMLA without affecting the integrity and biological activity of the antibody. Although the amount of antibody could also be determined using the bicinchoninic acid (BCA) method, our selective cleavage method gives more reliable results and is more powerful. Our approach provides a new direction for the component analysis of polymer nanoconjugates and nanoparticles. 相似文献