854 research outputs found
Phytochemical Screening, Antioxidant and Antibacterial Evaluations of Two Zingiberaceae Plants
The crude ethanolic extract of two commonly zingiberaceae medicinal plants Zingiber officinale (ginger) and Curcuma longa (turmeric) were screened for their phytochemical content which revealed the presence of alkaloids, glycosides, terpenoids, flavonoids, tannins and saponin
Proučavanje luminescencije uzbudom naviše u nanokristalima BaTiO3: Ho3+
Visible up-conversion emissions at 435, 545, 580, 675 and 690 nm and 437, 547, 575 and 675 nm have been obtained from BaTiO3 doped with 4 % Ho3+ ions in two different forms of the prepared samples, powder and thin film, under 808 nm laser diode excitation emissions. Combined with the energy level structure of Ho3+ ions and the kinetics of the visible emissions, the up-conversion mechanism has been analyzed and explained. The blue, green and red emissions of both samples have been attributed to the ground state-directed transition from 5F1, 5S2 and 5F5 states, respectively, which are populated through excited state absorption on 808 nm excitation. Nano-structure pure barium titanate and doped with different concentrations of Ho3+ ions in the form of powder and thin films have been prepared by so-gel technique, using barium acetate (Ba(CH3CHOO)2) and titanium isopropoxide (Ti((CH3)2CHO)4) as precursors. The thin films were prepared by spin-coating sol-gel method. The as-grown thin film and powders were found to be amorphous, which crystallized to the tetragonal phase after synthesization at 750 °C in air for 30 minutes. The crystallite size of thin film and powder samples both doped with 4 % Ho3+ ions, were found to be equal to 11 and 16 nm, respectively.Uzbudom laserskom diodom na 808 nm postigli smo emisije u vidljivom području na 435, 545, 580, 675 i 690 nm, te na 437, 547, 575 and 675 nm, u BaTiO3 punjenom s 4 % Ho3+ iona u uzorcima dvaju oblika, prahu i tankom sloju. Uzimajući u obzir stanja iona Ho3+ i kinetiku emisije fotona, analizirali smo i objasnili mehanizam uzbude naviše. Emisije oba uzorka u plavom, zelenom i crvenom području pripisuju se prijelazima u osnovno stanje sa stanja 5F1, 5S2 odn. 5F5 koja se pune apsorpcijom fotona 808 nm u višim stanjima Ho3+ iona. Metodom sol-gel pripremili smo nanostrukturni čist barijum titanat i barijum titanat punjen s dvjema koncentracijama Ho3+ iona, kao prah i kao tanke slojeve. Rabili smo barijum acetat (Ba(CH3CHOO)2) i titanijev izopropoksid (Ti((CH3)2CHO)4) za njihovu pripremu. Tanke smo slojeve dobivali centrifugiranjem sol-gela. Svježe pripremljeni tanki slojevi i prah su amorfni, ali se kristaliziraju zagrijavanjem na 750 ◦C u zraku tijekom 30 minuta. Veličina kristalita u tankom sloju i prahu, svaki punjen s 4 % Ho3+ iona, iznosi 11 odn. 16 nm
Fas-induced apoptosis in malnourished infants
Background: Malnutrition in children is frequently associated with an increased incidence of infection. Apoptosis of immune cells in undernourished organisms may cause an increase in the organism's susceptibility to diseases related to immune suppression. Lymphocyte apoptosis was described in malnutrition. The role of factor of apoptosis signal (fas,CD95) in apoptosis of lymphocyte populations in malnourished children is still unclear. Objective: This study investigated apoptosis in T lymphocytes in different types of malnutrition and the role of Fas in lymphocyte apoptosis and its relation to clinical and laboratory parameters of malnutrition. Study design: Sixty-three malnourished infants and children were compared to 27 healthy controls. Beside thorough history and clinical examination, laboratory investigations and flow cytometry assessment of T lymphocytes were done. The viability of T lymphocytes was determined by combination of fluorescence dye 7-amino actinomycin, CD95 and CD3. Results: There was significant increase in apoptotic T-cells in the patients compared to the controls. There was up-regulation of Fas expression in CD3+ cells. Furthermore CD3+/CD95+ cells were less viable than CD3+/CD95- cells of the patients and than CD3+/CD95+ cells of the controls. All the clinical and laboratory parameters of the studied patients showed no significant correlations with any of the apoptotic indices. Conclusion: Increased apoptosis in T lymphocytes in malnourished children may be the cause of the decrease in lymphocyte count in their peripheral blood. This in turn may be the cause of decreased cell mediated immunity and the more common occurrence of infection in such patients. Upregulation of Fas may be the cause of apoptosis in T lymphocytes in these malnourished children.Keywords: Fas, apoptosis, malnutrition, flow cytometry, infection, T lymphocytes.Egypt J Pediatr Allergy Immunol 2010;8(1):27-3
Adaptive gender-based thermal control system
A closed loop adaptive gender-based thermal control system (AG-TCS) is designed, modelled, analysed and tested. The system has the unique feature of adapting to the surrounding environment as a function of the number of humans present and the gender ratio. The operation of the system depends on a unique interface between a radio frequency identification (RFID) device and an imaging device, both of which are correlated and interfaced to a controller. Testing of the system resulted in smooth transition and shape conversion of the response curve, which proved its adaptability. Three mathematical equations describing the internal mechanisms of the AG-TCS are presented and have been proven to optimally reflect the original statistical data covering both genders
Exposure to the News Networks Through Social Media Sites and Their Reflections on Spreading Rumors among Students – Field Study
The scientific study aimed to identify rumors in the students society in the age of social media sites and confrontation mechanisms. The research community included a sample of experts who use new media. Descriptive and statistical approaches (interviews and questionnaires) are used to analyze and understand rumors through social media sites and how to confront them. The study came up with results, the most important of them are as follows: 62% of the research community believes that students (young people) use of news networks via social media sites affects the spread of rumors, while 63% of the research community considers that the quality of social media sites used by young people helps spread rumors, and 43% of the research community agree that technology users are predominantly young people, which helps spread the rumor. Finally, the study recommended that news sites pay attention to the method of dealing with crises, investigate accuracy and credibility, and increase the effective communication between the leaders and students institutions
Ramanovi i fotoluminescentni spektri čistih i kositrom obogaćenih tankih slojeva CdS pripremljenih prskanjem i pirolizom
Thin films of CdS, pure and enriched with different concentrations of tin up to 6%, were prepared by the spray pyrolysis technique. All samples were prepared at the deposition temperature of 420 ◦C. The XRD diagnostic data of the investigated samples revealed the polycrystalline nature of the as-deposited samples. The main characteristic peaks of CdS appeared in both pure and enriched films prepared by all used methods. The enrichment of Sn has no effect on positions of the characteristic peaks. The observed effect of Sn enrichment is the change in peak broadening which increases with the increase of Sn concentration. The thickness values ranged from 0.65 up to 1.15 µm. The samples of pure CdS show a sharp absorption edge at about 2.43 eV. The absorption coefficient α of the investigated samples was calculated from transmission and reflection spectra. Photoluminescence measurements show red emission band of the as-deposited samples, which was quenched by Sn incorporation. This band is ascribed to the excess of Cd which was checked by the energy dispersive X-ray (EDX) spectrometry. Raman spectra of samples with different concentrations of Sn were studied. They show remarkable increase of intensity when increasing the film thickness and decreasing the Sn concentration.Metodom prskanja i pirolize pripremali smo čiste i do 6% kositrom obogaćene tanke slojeve CdS. Sve uzorke smo pripremali na temperaturi polaganja od 420 ◦C. XRD spektri ispitivanih uzoraka pokazuju polikristaliničnu strukturu. Glavni karakteristični vrhovi CdS vide se i u čistim i u obogaćenim uzorcima pripremljenim primijenjenim metodama. Obogaćenje kositrom nema utjecaja na položaje karakterističnih vrhova. Međutim, javlja se proširenje vrhova koje se povećava pri povećanim koncentracijama kositra. Izmjerene i izračunate debljine slojeva su u skladu. Debljine slojeva bile su između 0.65 i 1.15 µm. Uzorci CdS pokazuju oštar apsorpcijski rub na oko 2.43 eV. Apsorpcijske koeficijente α ispitivanih uzoraka smo izveli iz transmisijskih i refleksijskih spektara. Mjerenja fotoluminescencije pokazuju crvenu emisijsku vrpcu koja trne dodavanjem kositra. Ta se vrpca tumači viškom Cd što smo potvrdili disperzivnom rendgenskom spektrometrijom (EDX). Proučavali smo i Ramanove spektre uzoraka s raznim koncentracijama kositra. Oni pokazuju snažan porast intenziteta za slojeve veće debljine i manje koncentracije kositra
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