Chemistry
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 STRUCTURES OF γ Al_2O_3 AND AlON STUDIED BY ~(27)Al NMR AND QUANTUM CHEMISTRY CALCTLATIONS
作者  
作者单位  
期刊  Acta Metallurgica Sinica(English Letters) 卷期  1999, 12(4 时间  2011.01.10
关键词  Al2 O3 and AlON,structure, NMR, quantum chemistrycalculation,
摘要  
 KB镜成像模拟以及与菲涅耳波带板成像的比较
作者  王晓方
作者单位  
期刊  光子学报 卷期  2010, 39(12 时间  2010.12.25
关键词  X射线成像
摘要   高空间分辨X射线成像是激光驱动惯性约束聚变研究的重要诊断手段.本文采用坐标变换方法自编光线追迹程序模拟了Kirkpatrick-Baez (KB)镜在X射线波段的掠入射成像,获得了视场、分辨率等结果.比较了给定参数条件下KB镜与菲涅耳波带板(FZP)两种高分辨X射线成像的特性, 给出两者各自适用范围.KB镜成像有比较高的系统效率, 在视场中心的空间分辨能力可达0.71 ?m,但偏离视场中心±200 ?m,空间分辨能力显著下降至6 ?m, 适用于较小视场的成像.FZP成像不仅在视场中心可以实现0.39 ?m的空间分辨能力,偏离视场中心达±13 mm,空间分辨能力也几乎不变,可实现大视场高分辨成像.
 Breastfeeding and Complementary Feeding Practices in Tanzania
作者  Hussein, AK
作者单位  
期刊  East African Journal of Public Health 卷期  Vol. 2, No. 1, 2005 时间  2010.12.20
关键词  Breastfeeding, complementary feeding practices, infant and young child feeding practices, WHO/ Linkages Tool, Tanzania
摘要   Objective:The main objective was to assess infant feeding practices in Tanzania as part of the process towards the development of the National Infant and Young Child Nutrition Strategy for Tanzania. Methods:Information was collected using Part One of the WHO/ Linkages Tool: Infant and young child feeding. A tool for assessing national practices, policies and programmes (WHO, 2003) and through review of published literature. Results:Using Tanzania Reproductive and Child Health Survey (1999) data, Tanzania scored "good" on three of the five rated indicators on the WHO/ Linkages Tool. These are - percentage of babies breastfed within one hour of birth (60%), median duration of breastfeeding for children below 36 months of age (20.9%) and percentage of breastfed babies 7-<10 months who received complementary foods in the last 24 hours (90.7%). Tanzania did not score well on the other two indicators – percentage of babies 0-<6 months exclusively breastfed in the last 24 hours (31.8%) and percentage of babies 0-<12 months of age who received any food or drink from bottles in the last 24 hours. There were limited published reports on infant and young child feeding practices in Tanzania. However, information from published Tanzanian Demographic and Health Survey reports compared well with findings of published articles reviewed. Although initiation of breastfeeding was established to be almost universal, undesirable practices of discarding colostrum, giving prelacteal feeds, short duration of exclusive breastfeeding as well as too early and delayed introduction of complementary foods were found to be common in some parts of Tanzania. Conclusions:There is need for more research on breastfeeding and complementary feeding practices in Tanzania and especially among HIV positive and working mothers. Strong advocacy on the importance of optimal breastfeeding and complementary feeding practices, and raising awareness of working mothers on their entitlement to paid breastfeeding breaks during working hours are recommended.
 Partitioning of major and trace inorganic contaminants in fly ash acid mine drainage derived solid r
作者  Gitari, W.M.;Leslie, F.P.;Key, D.L. & Okujeni, C.
作者单位  
期刊  International Journal of Environment Science and Technology 卷期  Vol. 7, No. 3, 2010 时间  2010.12.13
关键词  Acid mine drainage; Fly ash; Neutralization; Residue; Sequential extraction
摘要   Acid mine drainage was reacted with coal fly ash over a 24 h reaction time and species removal trends evaluated. The evolving process water chemistry was modeled by the geochemical code PHREEQC using WATEQ4 database. Mineralogical analysis of the resulting solid residues was done by X-ray diffraction analysis. Selective sequential extraction was used to evaluate the transfer of species from both acid mine drainage and fly ash to less labile mineral phases that precipitated out. The quantity of fly ash, volume of acid mine drainage in the reaction mixture and reaction time dictated whether the final solution at a given contact time will have a dominant acidic or basic character. Inorganic species removal was dependent on the pH regime generated at a specific reaction time. Sulphate concentration was controlled by precipitation of gypsum, barite, celestite and adsorption on iron-oxy-hydroxides at pH > 5.5. Increase of pH in solution with contact time caused the removal of the metal ions mainly by precipitation, co-precipitation and adsorption. PHREEQC predicted precipitation of iron, aluminium, manganese-bearing phases at pH 5.53-9.12. An amorphous fraction was observed to be the most important in retention of the major and minor species at pH > 6.32. The carbonate fraction was observed to be an important retention pathway at pH 4-5 mainly due to initial local pockets of high alkalinity on surfaces of fly ash particles. Boron was observed to have a strong retention in the carbonate fraction.
 THE VALUE OF LEAFY VEGETABLES: AN EXPLORATION OF AFRICAN FOLKLORE
作者  Owuor, Onyango Bethwell & Olaimer-Anyara, Ekisa
作者单位  
期刊  African Journal of Food Agriculturen Nutrition and Development 卷期  7 时间  2010.08.11
关键词  Indigenous Leafy Vegetables, culture, folklore
摘要   Indigenous Leafy Vegetables foods have an exceptional place in African cuisine. It is commonly argued that vegetable consumption reflects cultural backgrounds and their value transcends a biological one, as food, to symbolism enhancing the functioning of society and promoting social order. This study set to determine species use, folkloric dimensions and taste preferences in a rural East African setting. A bio-cultural approach reinforced by ethno-botanical tools conducted over a three-year period and recourse to a corpus of Luo ethnic food plant literature and gathering of folklore elements from a conversational context was used to study socio-cultural elements of vegetables foods of people in Migori and Suba districts of Kenya. Seventy-four respondents, 56 female and 18 males, of mean age 43 years and ranging between 16 and 84 years participated in focus group discussions and research interviews. Herbarium specimens of 34 leafy edible plant species in seventeen plant families are deposited at the University of Nairobi and the Catholic University of Eastern Africa herbaria. This study documents 17 sayings (folkloristic products) of different genre: mantras, traditional beliefs, customs, practices, folk stories/ tales, songs, jokes and lexical phrases. Their sociolinguistic analysis reveals they address issues appropriate to Luo ritual, social status, nutrition, taste preferences, cooking habits and conflict resolution. Though Luo folklore indicates aversion for bitter vegetables, the body of folkloric wisdom sustains vegetable dish consumption. The preference and craving for bitter tasting herbs by elder women was because of an understanding of both food and medicinal values. This paper concludes that vegetable consumption reflects cultural backgrounds and experiences. Folklore defines how Africans perceive, define, and value indigenous Leafy Vegetables in their own terms and presents a stable platform for cultural analysis of oral food culture. Indigenous Leafy Vegetables are symbolic "sources of illumination" that orient African people persistently with the system of meaning in their culture.
 Salt Iodization And Iodine Status Among Infants And Lactating Mothers In Papua New Guinea
作者  Temple, VJ;Oge, R;Daphne, I;Vince, JD;Ripa, P;Delange, F & Eastman, CJ
作者单位  
期刊  African Journal of Food Agriculturen Nutrition and Development 卷期  Vol. 9, No. 9, 2010 时间  2010.07.27
关键词  Iodine, Salt, Urinary, Infants, Mothers
摘要   Universal salt iodization is the most effective and sustainable intervention strategy for the prevention, control, and elimination of iodine deficiency. This cross-sectional study assessed the per capita consumption and availability of adequately iodised salt in households, and the iodine status of infants 7 - 120 days old and their lactating mothers in the National Capital District, Papua New Guinea. Salt samples were obtained from households selected by simple random sampling. The mean daily per capita consumption of salt was 5.6 ± 1.5g. The mean iodine content in salt from households and trade-stores was 33.38 ± 18.04ppm and 44.20 ± 12.10ppm, respectively. Adequately iodised salt was available in 94.48% of households and in 100% of trade-stores. The calculated mean daily per capita discretionary intake of iodine was 186.93ug, which is below the 250ug recommended for lactating mothers. Casual urine samples selected by simple random sampling were used to determine the iodine status of infants and mothers. Urinary iodine concentration (UIC) was estimated by Sandell-Kolthoff reaction. Mean age of infants was 46.9 ± 28.2 days (95% confidence-interval 41.3 - 52.5 days). Median UIC of infants and of their lactating mothers was 253.5ug/L (interquartile-range 165.3 - 363.0ug/L) and 124.5ug/L (interquartile-range 93.0 - 161.0ug/L), respectively, indicating that iodine deficiency is not of public health significance among infants and lactating mothers. Eighty percent of the infants were exclusively breast-fed and 20% were mixed-fed. The median UIC for the exclusively breast-fed and mixed-fed infants was 251.0ug/L (interquartile-range 177.0 - 338.6ug/L), and 290.0ug/L (interquartile-range 147.1 - 425.5ug/L), respectively, indicating optimal status of iodine nutrition. The UIC of exclusively breast-fed infants was significantly (P < 0.001) higher than the UIC of their mothers. Spearman’s correlation test showed weak non-significant linear relationship (r = 0.118, P = 0.297) between UIC of the exclusively breastfed-infants and their mothers. Despite success in the implementation of the universal salt iodization strategy in the National Capital District, mild to moderate status of iodine nutrition was prevalent in 33.8% of the exclusively breastfeeding-mothers, although their exclusively breastfed-infants were nourished with iodine. There is, therefore, a need to advocate strongly for increased dietary intake of iodine by lactating mothers. The findings strongly indicate the urgent need for an efficient, sustainable, and functional monitoring system to strengthen and improve on the achievements of the universal salt iodization strategy in National Capital District.
 Urinary Schistosomiasis And Iron Deficiency Anemia Among Malian School Children
作者  Ayoya, MA;Koné, KM & Traoré, AK
作者单位  
期刊  African Journal of Food Agriculturen Nutrition and Development 卷期  Vol. 9, No. 9, 2010 时间  2010.07.27
关键词  Urinary schistosomiasis, anemia, children, Mali
摘要   Anemia continues to be a major public health problem in many countries. The prevalence and intensity of urinary schistosomiasis, which contributes to anemia, often peak at school age adding to that age group’s nutrition and disease burdens. However, unlike malaria and hookworm infections, little is known on the role of urinary schistosomiasis in iron deficiency anemia. The objective of this study was to assess the prevalence of iron deficiency anemia and the effect of iron supplementation on hemoglobin (Hb) and serum ferritin (SF) levels among school children infected withSchistosomahaematobiumin Bamako, the capital city of Mali. A total of 150 anemic school children between 7 and 12 years were randomly assigned to receive either 40mg/kg of praziquantel or 40mg/kg of praziquantel (P) + daily 66 mg of iron (Fe), five days a week for three months. Hb and SF were measured at baseline and at 6 and 12 weeks of the intervention. Only children who had complete Hb and SF data at each stage of the trial were included in the statistical analyses (n = 74 in the P+Fe group; n = 66 in the P group). At baseline, mean Hb (g/dl) was 10.53±0.93 in the P group and 10.47±1.17 in the Fe+P group; mean SF (µg/l) was 34.39±37.58 in the P group and 29.82±23.34 in the Fe+P group, and the prevalence of iron deficiency was 17.2%. At 6 and 12 weeks of the intervention, there was an important reduction in anemia and in iron deficiency in both treatment groups. Mean Hb (g/dl) was higher in the Fe+P group (11.63±0.88 and 11.55±0.94) than in the P group (11.14±0.98 and 10.84±0.86) at 6 and 12 weeks, respectively. Mean SF (µg/l) was also higher in the P+Fe group (74.26±40 and 100.29±53.92) than in the P group (40.65±35.63 and 40.70±29.57) at 6 and 12 weeks, respectively. In theseSchistosoma haematobiuminfected children, iron deficiency was prevalent and treatments with P alone or in combination with Fe supplementation were able to increase hemoglobin and iron stores. Neither P nor P+Fe by alone completely reversed anemia in this sample population.
 The Importance of O - Level Grades in MedicalSchool Admission: The University of Ado - Ekiti Experie
作者  D. D. O. Oyebola
作者单位  
期刊  African Journal of Biomedical Research 卷期  Vol. 9, No. 1, 2006 时间  2010.07.27
关键词  JAMB, O' level grades, Medical school, Admission, Interview, Academic achievement, Ado-Ekiti
摘要   This paper describes the procedures used in the admission of the first set of Medical Students into the newly established College of Medicine, University of Ado - Ekiti. Two groups of students were admitted, namely, those admitted on the basis of their JAMB scores alone (five students) and those admitted on the basis of a combination of JAMB scores and O' level grades in Physics, Chemistry, Biology and Mathematics. In the latter group, the JAMB scores and O' level grades were given equal weighting (50% of mark obtainable each) and all applicants were ranked on the basis of their combined scores. The 127 top scorers based on this ranking were given a written interview test and an oral interview. At the end of the exercise, 40 candidates were admitted. Eventually, 31 of this group and four out of the five candidates admitted with JAMB scores alone registered for 100 Level courses. A comparison of the academic performance of the two groups of students in science and General Studies courses at 100 Level showed that all students in the JAMB and O' level group were far better than students in the JAMB alone group. Indeed, the former group had outstanding performance while 50% of the latter group could not cope. It was concluded that the use of O' level grades is very important and effective in selecting academically sound students and should be used in admissions into Medical Schools.
 Home-based Practices Of Complementary Foods Improvement are Associated With Better Height-for-age Z
作者  Ouédraogo, H.Z.;Nikièma, L.;Somé, I.;Sakandé, J.;Dramaix-Wilmet, M. & Donnen, P.
作者单位  
期刊  African Journal of Food Agriculturen Nutrition and Development 卷期  Vol. 8, No. 2, 2008 时间  2010.07.27
关键词  Fortification, Cereals, Stunting, Children, Burkina
摘要   Repositioning nutrition is central to development. Childcare practices, which include feeding practices, appear in the conceptual framework of malnutrition. The objective of this study was to analyze the nutritional status of young children in relation to feeding practices. This cross-sectional, community-based study was conducted in the rural district of Kongoussi (Burkina Faso). Three hundred ninety nine children (95% of expected 420 children: 30 clusters of 14 children), 6-23 months of age, were recruited by "probability proportionate-tosize" cluster sampling. Items related to the early and current breastfeeding patterns and the mode of complementary feeding were recorded by interview of the mothers. Fortified cereals were defined as home-based improved flours by mixing "soumbala," fishmeal, toasted groundnut, or several of these local foods with cereal. Soumbala is a fermented product from the African bean tree used both as a condiment and as a meat substitute in soups, because it is rich in protein and micronutrients. The height-for-age Z-score (HAZ) and weight-for-height Z-score (WHZ) were computed using height and weight measurements. Adjusted mean HAZ and WHZ were derived from multiple linear regression models and compared using analysis of variance (ANOVA) and post hoc t-test with Bonferroni correction. The prevalence of wasting was 26.3% (95% CI: 21.5% - 30.5%). The mean WHZ (± standard deviation) was –1.39 (± 1.14). The WHZ was associated with the children’s age and the mother’s nutritional status. The prevalence of stunting was 35.8% (95% CI: 29.4% - 41.1%). The mean HAZ was –1.68 (± 1.15). After adjustment for children, mothers and household characteristics, and for current and past breastfeeding patterns, the HAZ remained associated with the mode of complementary feeding among children 12-23 months of age (p=0.018), but not among children 6-11 months of age (p=0.136). Among children 12-23 months of age, the adjusted mean HAZ (standard error) was –1.33 (0.63), -1.61 (0.30), and –2.11 (0.32) for children using fortified cereals, unfortified cereals, or no complementary feeding, respectively (p=0.018). These results underline the high frequency of malnutrition in the rural district of Kongoussi, and the great need for nutritional intervention. The prevention of growth impairment in this area could be based on home fortification of complementary foods using locally available foods; this is more sustainable. Thorough research is needed to specify and standardize the procedures of utilisation of the available foods in the prevention of growth impairment.
 L-Glutamic acid and glutamine: Exciting molecules of clinical interest
作者  Kulkarni Chanda, Kulkarni KS, Hamsa BR
作者单位  
期刊  Indian Journal of Pharmacology 卷期  Vol. 37, No. 3, 2005 时间  2010.07.27
关键词  Amino acid; glutamic acid; glutamine
摘要   Glutamine is one of the most abundant amino acids and participates in a variety of physiological functions, namely - as a major fuel source for enterocytes, as a substrate for neoglucogenesis in kidney, lymphocytes, and monocytes, a nutrient/substrate in muscle protein metabolism in response to infection, inflammation, and muscle trauma. Studies evaluating the role of glutamine have confirmed it's participation in maintaining mucosal integrity of the gastrointestinal tract following it's administration in patients with major bowel surgery. The role of glutamine as a protective agent in hepatobiliary dysfunction and as a supplement in total parenteral nutrition is well established, particularly, in patients under intensive care. L-Glutamic acid (L-GA) physiologically exists as glutamate. Glutamate along with glutamine plays a major role in amino acid metabolism and thus in maintaining nitrogen balance in the body. Glutamate is a well-established excitatory neurotransmitter in the central nervous system. There has been convincing evidence on protective activity of L-GA and α-ketoglutarate in vincristine-induced neurotoxicity. Based on the above information, a large number of studies have been carried out. The findings of recent clinical studies are presented below. Looking at the wide profile of activity, it has been proposed that though L-GA and glutamine were once considered nonessential for health, may now be considered as - 'conditionally essential' amino acids. While complete therapeutic role is yet to be elucidated, it may be anticipated that L-GA and glutamine may prove to be exciting molecules of interest to clinicians. The future research may therefore be directed at confirming the above activities and at investigating their role in other clinical conditions.
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