CRYSTALLIZATION KINETICS OF GLASS-CERAMICS BY DIFFERENTIAL THERMAL ANALYSIS

The crystallization behavior of fluorphlogopite, a glass-ceramic in the MgO–SiO2–Al2O3–K2O–B2O3–F system, was studied by substitution of Li2O for K2O in the glass composition. DTA, XRD and SEM were used for the study of crystallization behavior, formed phases and microstructure of the resulting glass-ceramics. Crystallization kinetics of the glass was investigated under non-isothermal conditions, using the formal theory of transformations for heterogeneous nucleation. The crystallization results were analyzed, and both the activation energy of crystallization process as well as the crystallization mechanism were characterized. Calculated kinetic parameters indicated that the appropriate crystallization mechanism was bulk crystallization for base glass and the sample with addition of Li2O. Non-isothermal DTA experiments showed that the crystallization activation energies of base glasses was in the range of 234-246 KJ/mol and in the samples with addition of Li2O was changed to the range of 317-322 KJ/mol

Essential oil and apple pomace affect fermentation and aerobic stability of alfalfa silage

This study assessed the effects of the additions of an essential oil (EO), composed of ricinoleic acid, cardol, cardanol, and apple pomace, on fermentation quality and aerobic stability of alfalfa silages. The experimental treatments consisted of T1) alfalfa (control), T2) alfalfa with EO, T3) alfalfa (75%) with apple pomace (25%), T4) alfalfa (75%) with apple pomace (25%) and EO, T5) alfalfa (50%) with apple pomace (50%), T6) alfalfa (50%) with apple pomace (50%) and EO, T7) alfalfa (25%) with apple pomace (75%), and T8) alfalfa (25%) with apple pomace (75%) and EO. The addition of apple pomace decreased the silage pH compared with the control (P <0.01). Apple pomace at 25% level increased the total volatile fatty acid (iVFA) content (P <0.05). Essential oil (EO) decreased tVFA and increased dry matter (DM) content 90 days after ensiling (P <0.01). Apple pomace decreased ammonia (N-NH3), crude protein (CP), and crude ash (CA) content and increased the amounts of neutral detergent fibre (NDF) and acid detergent fibre (ADF) (P <0.01). Essential oil and apple pomace (level 75%) increased effective digestibility (P <0.05). Apple pomace decreased aerobic stability and the addition of EO increased aerobic stability (P <0.05). Thus, use of apple pomace as a source of fermentable carbohydrate and/or the addition of EO in the preparation of high-quality alfalfa silage is recommended to offset its high buffering capacity and low carbohydrate content

Effect of a Hydroalcoholic Extract of Rosa сanina Flowers on Anxiety in Rats

We investigated effects of the hydroalcoholic extract of Rosa сanina (dog rose) petals on behavior of rats in the elevated plus-maze (EPM) test; adult male Wistar rats weighing 200-240 g were used. Oral everyday administration of the Rosa extract in three doses (150, 300, and 450 mg/kg) was done for one week. Animal behavior in the EPM was videotaped for 10 min, and conventional indices considered to be related to the anxiety level were scored. Introduction of the Rosa canina extract significantly increased the number of open arm entries in a dose-dependent manner and also increased the time of stay in the open arms at a high dose (450 mg/kg). At the same time, the number of closed arm entries interpreted as a correlate of the locomotion intensity did not differ from the control at all doses. Thus, the Rosa canina extract, when orally administered, demonstrates an anxiolytic profile in rats. Future investigations are essential for better understanding of the anxiolytic properties of the extract and neurobiological mechanisms of its action (probable interactions of the Rose extract active agents with neurotransmitter systems.Ми досліджували впливи водоспиртового екстракту з квітів шипшини (Rosa canina) на поведінку щурів у припіднятому хрестоподібному лабіринті; тестували дорослих самців (маса тіла 200–240 г). Екстракт із квітів шипшини вводили перорально (дози 150, 300 або 450 мг/кг) щоденно протягом одного тижня. Здійснювали відеозапис поведінки тварин у лабіринті протягом 10 хв і підраховували стандартні показники, пов’язані з рівнем тривожності. Введення екстракту квітів шипшини зумовлювало вірогідне дозозалежне збільшення числа входжень до відкритих рукавів лабіринту та істотне збільшення тривалості перебування в цих рукавах (останнє лише в разі найбільшої дози, 450 мг/кг). У той же час кількість заходжень до закритих рукавів лабіринту (корелят інтенсивності локомоції) не відрізнялася від контролю при всіх дозах. Отже, пероральне введення екстракту продемонструвало його анксіолітичний профіль в експериментах на щурах. Необхідні подальші дослідження анксіолітичних властивостей екстракту та нейробіологічних механізмів його дії (зокрема, можливої взаємодії активних агентів екстракту із нейротрансмітерними системами)

A Prospective Study on Risk Factors for Acute Kidney Injury and All-Cause Mortality in Hospitalized COVID-19 Patients From Tehran (Iran)

Background: Several reports suggested that acute kidney injury (AKI) is a relatively common occurrence in hospitalized COVID-19 patients, but its prevalence is inconsistently reported across different populations. Moreover, it is unknown whether AKI results from a direct infection of the kidney by SARS-CoV-2 or it is a consequence of the physiologic disturbances and therapies used to treat COVID-19. We aimed to estimate the prevalence of AKI since it varies by geographical settings, time periods, and populations studied and to investigate whether clinical information and laboratory findings collected at hospital admission might influence AKI incidence (and mortality) in a particular point in time during hospitalization for COVID-19. Methods: Herein we conducted a prospective longitudinal study investigating the prevalence of AKI and associated factors in 997 COVID-19 patients admitted to the Baqiyatallah general hospital of Tehran (Iran), collecting both clinical information and several dates (of: birth; hospital admission; AKI onset; ICU admission; hospital discharge; death). In order to examine how the clinical factors influenced AKI incidence and all-cause mortality during hospitalization, survival analysis using the Cox proportional-hazard models was adopted. Two separate multiple Cox regression models were fitted for each outcome (AKI and death). Results: In this group of hospitalized COVID-19 patients, the prevalence of AKI was 28.5% and the mortality rate was 19.3%. AKI incidence was significantly enhanced by diabetes, hyperkalemia, higher levels of WBC count, and blood urea nitrogen (BUN). COVID-19 patients more likely to die over the course of their hospitalization were those presenting a joint association between ICU admission with either severe COVID-19 or even mild/moderate COVID-19, hypokalemia, and higher levels of BUN, WBC, and LDH measured at hospital admission. Diabetes and comorbidities did not increase the mortality risk among these hospitalized COVID-19 patients. Conclusions: Since the majority of patients developed AKI after ICU referral and 40% of them were admitted to ICU within 2 days since hospital admission, these patients may have been already in critical clinical conditions at admission, despite being affected by a mild/moderate form of COVID-19, suggesting the need of early monitoring of these patients for the onset of eventual systemic complications

Resistance of 14 accessions/cultivars of Lycopersicon spp. to two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), in laboratory and greenhouse

Fourteen accessions and cultivars of Lycopersicon spp. were studied to evaluate their resistance to two-spotted spider mite, Tetranychus urticae Koch, under laboratory and greenhouse conditions. In vitro studies were carried out using thumbtack and leaf disk bioassays. Lycopersicon hirsutum and L. pennellii accessions supported more mites on the tack. The highest number of eggs (5.15 ± 0.48 eggs / â / d) was recorded on L. pimpinellifolium LA2533 and the lowest number (0 egg / â / d) was recorded on L. hirsutum and L. pennellii accessions. The highest mite mortality and lowest damage score occurred on the leaf disks of L. pennellii and L. hirsutum accessions that were strikingly in contrast to our observations on L. esculentum varieties (Nandi and Sankranthi). The developmental time of the mite was longest (8.61 ± 0.18 days) on leaf disks of L. esculentum NDTVR-73 and shortest (7.18 ± 0.51 days) on L. pimpinellifolium LA2533. In the greenhouse, the mite was unable to establish on L. hirsutum and L. pennellii accessions. Amongst the rest, Nandi and Sankranthi accessions/cultivars supported the highest, while NDTVR-73 supported the lowest mite population. The highest and lowest density of type VI glandular trichomes were recorded on L. esculentum NDTVR-73 (67.33 ± 6.34 trichomes/mm²) and L. pennellii LA2963 (0.79 ± 0.15 trichomes/mm²), respectively. No relation was found between density of type VI trichomes and resistance to the mite. Type IV glandular trichomes were observed only on the foliages of L. hirsutum and L. pennellii. A positive relation exists between the density of type IV glandular trichomes and resistance to the mite

The Octet Structure Function and Radiative Quarkonia Decay

The Operator Product Expansion, in conjunction with the power counting of non-relativistic field theory, is used to examine the end-point region of the radiative decay of heavy quark bound states with $^3S_1$ quantum numbers, $Q\bar{Q}\rightarrow \gamma+X$. We identify an infinite class of operators that determine the shape of the photonic end-point spectrum. These operators can be resummed to form an octet structure function which parameterizes the energy of the dynamical gluon content of the leading octet Fock state component of the quarkonium. This color-octet contribution is important when the photon spectrum is examined with a resolution given by $\Delta E_\gamma \sim m_Qv^2$, where $v^2$ is the relative quark velocity squared. The formalism used makes explicit the shift of the end-point from its partonic to its hadronic value.Comment: 9 pages, LaTex, Contribution from ^1S_0 include

Combining CP Asymmetries in B→KπB \to K \pi Decays

We prove an approximate relation, to leading order in dominant terms, between CP-violating rate differences in $B^0/\bar{B}^0 \to K^{\pm}\pi^{\mp}$ and $B^{\pm} \to K^{\pm}\pi^0$. We show how data from these two processes may be combined in order to enhance the significance of a nonzero result.Comment: 9 pages, latex, no figures, submitted to Phys. Rev. Letters, revise

Colour-Octet Effects in Radiative Υ\Upsilon Decays

We investigate the effects of colour-octet contributions to the radiative $\Upsilon$ decay within the Bodwin, Braaten and Lepage NRQCD factorization framework. Photons coming both from the coupling to hard processes (`direct') and by collinear emission from light quarks (`fragmentation') are consistently included at next-to-leading order (NLO) in $\alpha_s$. An estimate for the non-perturbative matrix elements which enter in the final result is then obtained. By comparing the NRQCD prediction at NLO for total decay rates with the experimental data, it is found that the non-perturbative parameters must be smaller than expected from the na\"\i ve scaling rules of NRQCD. Nevertheless, colour-octet contributions to the shape of the photon spectrum turn out to be significant.Comment: 25 pages, Latex, 8 figure

Kinematic Effects in Radiative Quarkonia Decays

Non-relativistic QCD (NRQCD) predicts colour octet contributions to be significant not only in many production processes of heavy quarkonia but also in their radiative decays. We investigate the photon energy distributions in these processes in the endpoint region. There the velocity expansion of NRQCD breaks down which requires a resummation of an infinite class of colour octet operators to so-called shape functions. We model these non-perturbative functions by the emission of a soft gluon cluster in the initial state. We found that the spectrum in the endpoint region is poorly understood if the values for the colour octet matrix elements are taken as large as indicated from NRQCD scaling rules. Therefore the endpoint region should not be taken into account for a fit of the strong coupling constant at the scale of the heavy quark mass.Comment: LaTeX, 17 pages, 5 figures. The complete paper is also available via the www at http://www-ttp.physik.uni-karlsruhe.de/Preprints