In vitro immunosuppressive activity of tacrolimus dihydrodiol precursors obtained by chemical oxidation and identification of a new metabolite of SDZ-RAD by electrospray and electrospray-linked scan mass spectrometry

Different tacrolimus epoxides and dihydrodiol epoxides arising from the chemical oxidation of the parent drug are described. Open-chain tautomeric forms involving the lactone function were identified for the tacrolimus epoxides. Moreover, the identification by electrospray and electrospray linked scan mass spectrometry of an SDZ-RAD C16-C27 O-demethyl 17, 18-19, 20-21, 22 tris-epoxide new metabolite isolated from pig liver microsomes is reported. The in vitro immunosuppressive activity, using mixed lymphocyte reactions of the two macrolide reported oxidation compounds are discussed.     

卤化氢共振增强多光子电离光谱

测定了卤化氢(HCl, HBr 和HI) (2+1)共振增强多光子电离(REMPI)光谱, 采用模拟计算法分析推导出转动常数、谱带源以及Ω态振动谱带的同位素位移值. 得到的HCl数据同Green等人用常规分析法所推导的结果极为吻合. 得出8条振动谱带,其中包括V(¹∑⁺)态, E(¹∑⁺)的v'=4态以及HBr的5个新谱带, 此外还推导出HI的E态v'=1的4个振动谱带光谱参数. 观测了V和E态之间因同类相互作用而产生的不规则能级间距、转动参数和同位素位移. 讨论了HCl和HBr的E态和V态振动谱带中的转动谱线序列O和S对Q的强度比变化,提出了双光子激发机理.     

Global dynamics of an epidemiological model with age-of-infection dependent treatment rate

We revisit a previously established model for influenza transmission dynamics, in which antiviral treatment as a single containment strategy was administered within a specified window of opportunity for initiating treatment. We extend this model to a more general framework with age-of-infection dependent treatment rates. The resulting age structured model can be transformed into a closed system of delay differential equations, for which we perform a complete global stability analysis. By constructing suitable Lyapunov functions, we show that the effective reproduction number fully characterizes the possible outcomes of disease dynamics. Our results allow us to evaluate treatment strategies and examine the impact of treatment delays on the potential success of disease control.     

A survey of stochastic modelling approaches for liberalised electricity markets

Liberalisation of energy markets, climate policy and the promotion of renewable energy have changed the framework conditions of the formerly strictly regulated energy markets. Generating companies are mainly affected by these changing framework conditions as they are exposed to the different risks from liberalised energy markets in combination with huge and largely irreversible investments. Uncertainties facing generating companies include: the development of product prices for electricity as well as for primary energy carriers; technological developments; availability of power plants; the development of regulation and political context, as well as the behaviour of competitors.     

Gold nanoparticle included graphene oxide modified electrode: Picomole detection of metal ions in seawater by stripping voltammetry

We obtained a gold nanomaterial/graphene oxide-modified glassy carbon electrode and characterized it using transmission electron microscope, scanning electron microscope, cyclic voltammetry (CV), and X-ray photoelectron spectroscopy techniques. A response of the electrode using square wave anodic stripping voltammetry for Pb²⁺, Cu²⁺, and Hg²⁺ was found linear in the range from 1 × 10^–7 to 1 × 10^–11 M. The detection limits of Pb²⁺, Cu²⁺ and Hg²⁺ were 0.14, 0.5 and 1.2 pM, respectively. The method was applied to the simultaneous determination of Pb²⁺, Cu²⁺ and Hg²⁺ in seawater samples from a coastal region of Anatolia, and the results corresponded well with the values obtained by inductively coupled plasma-optical emission spectroscopy.     

Determination of the chemical composition and Raman characterization of barite samples from Denizli and Akdamadeni,Turkey, using Energy Dispersive X-ray fluorescence and Raman microscopy

Accurate analysis of samples is very important for scientists working in many fields. XRF device is used very frequently especially in mine analysis. However, researchers are trying to reach accurate results with many different analysis methods. In addition to the known analysis methods, alternative research methods also guide the studies. In this study, two barite ore samples, collected from two regions of different nature (Denizli and Akda?madeni) by following specified sampling methods, were analyzed using Confocal Raman Spectroscopy (CRS) and Polarized Energy Dispersive X-Ray Fluorescence (PEDXRF) spectrometer. The first sample was from a metamorphic basement, and the second was from an alkali syenite rock unit. The main objective of this paper is to compare the optical characteristics of these two different barite samples collected from different regions under a polarized microscope, using CRS and PEDXRF. The results of polarized microscopy analysis showed that the barite taken from Denizli is associated with calcite. On the other hand, the barite taken from Akda?madeni is associated with galena, celestite, and quartz. Two different colors were observed in the barite samples. CRS and PEDXRF results showed that the barites collected from two regions differed in mineral association, chemical composition, and physical properties. The accuracy of the chemical analysis technique was ensured by following USGS standards, GBW 7109, and GBW-7309 Sediment. Barite ores were analyzed using HR-800 (HORIBA-Jobin Yvon) CRS and a polarized microscope (Leica DMLP). Thanks to this study, it has been shown that mineral analyzes can be performed with an accuracy close to XRF with Confocal Raman spectroscopy. Confocal Raman spectroscopy will also guide researchers for mineral analysis.