The Effect of Antiretroviral Therapy on SIRT1, SIRT3 and SIRT6 Expression in HIV-Infected Patients

Human Immunodeficiency Virus (HIV) infection and the chronic use of combined antiretroviral therapy (cART) may affect the occurrence of certain disturbances in the body. There is growing interest in sirtuins–enzymes involved in the regulation of many metabolic processes in the organism and in the pathogenesis of many diseases which also exhibit potential antiviral activity. The aim of the study was to investigate the connection of cART to the expression of Sirtuin 1 (SIRT1), Sirtuin 3 (SIRT3) and Sirtuin 6 (SIRT6) in HIV-infected men. The plasma levels of sirtuins were measured before and one year after cART, and related to HIV viral load, lymphocytes T CD4+ and CD8+ count as well as the applied cART. The levels of sirtuins in plasma were measured in HIV-infected patients (n = 53) and the control group (n = 35) by immunoassay methods. There were statistically significant (p < 0.05) differences between SIRT6 in the HIV-infected patients before therapy and in the subgroups, depending on the count of lymphocytes T CD8+. There were significant differences in the levels of SIRT1 depending on the applied treatment regimen. The obtained results indicate the most significant changes in the expression of SIRT6 in the course of HIV infection and suggest an influence of the type of cART on the level of SIRT1, which indicates its important role in the course of HIV.     

Give or Take: Effects of Electron-Accepting/-Withdrawing Groups in Red-Fluorescent BODIPY Molecular Rotors

Mapping microviscosity, temperature, and polarity in biosystems is an important capability that can aid in disease detection. This can be achieved using fluorescent sensors based on a green-emitting BODIPY group. However, red fluorescent sensors are desired for convenient imaging of biological samples. It is known that phenyl substituents in the β position of the BODIPY core can shift the fluorescence spectra to longer wavelengths. In this research, we report how electron-withdrawing (EWG) and -donating (EDG) groups can change the spectral and sensory properties of β-phenyl-substituted BODIPYs. We present a trifluoromethyl-substituted (EWG) conjugate with moderate temperature sensing properties and a methoxy-substituted (EDG) molecule that could be used as a lifetime-based polarity probe. In this study, we utilise experimental results of steady-state and time-resolved fluorescence, as well as quantum chemical calculations using density functional theory (DFT). We also explain how the energy barrier height (Ea) for non-radiative relaxation affects the probe’s sensitivity to temperature and viscosity and provide appropriate Ea ranges for the best possible sensitivity to viscosity and temperature.     

Luminescence lifetime-based sensor for cyanide and related anions

A new Ru(II) complex is described which serves as a luminescence lifetime-based sensor for fluoride and cyanide anions (KF = 640 000 mol-1, KCN = 430 000 mol-1). This chromophore displays observable changes in its UV-vis and steady-state luminescence spectra upon cyanide binding. Prior to cyanide addition, this complex exhibits a single-exponential lifetime (tau = 377 +/- 20 ns). With increasing cyanide concentrations, the intensity decays are composed of two exponentials: long tau (320-370 ns) and short tau (13-17 ns). The average lifetimes shorten as a function of cyanide concentration since the fractional intensity shifts from an initial dominant long lifetime component to the short lifetime component. This work represents the first example of a direct method for the luminescence lifetime-based sensing of anions.     

Simple electrooptical sensors for inorganic anions

[reaction: see text] Electrooptical sensors consisting of a conjugated chromophore undergoing a change in color and a redox-active moiety such as quinone fused to the chromophore were synthesized. Strong changes in colorimetric and electrochemical properties were observed in the presence of inorganic anions. A unique anion-specific response was observed for fluoride, pyrophosphate, and acetate. DFT (B3LYP/6-31G) calculations performed for both "on/off" states of a sensor-fluoride model are in good agreement with the observed electrochemical and spectroscopic data.     

Evaluation of automated synthesis for chain and step‐growth polymerizations: Can robots replace the chemists?

This article explores current challenges in the use of automated parallel synthesizers in polymeric materials research. Four types of polymerizations were investigated: carbodiimide‐mediated polyesterification, diphenol phosgenation, free radical, and reversible addition‐fragmentation chain‐transfer (RAFT). Synthetic challenges of condensation polymerization, such as liquid and solid dispensing accuracy, dropwise addition, and toxic chemical handling, were successfully met using the automated synthesizer. Both solid and liquid dosing of the diphenol and diacid were successful for polyarylate synthesis. The high precision of liquid dispensing made it possible to achieve stoichiometric balance using reagent stock solutions. For all reactions, molecular weights and their reproducibility were comparable to those obtained with manual synthesis. For RAFT polymerizations, solvent and mol ratio of chain transfer reagent to initiator were successfully optimized on the automated synthesizer and a library of over 60 polymethacrylate copolymer compositions was generated. Considerable savings in time relative to manual methods were achieved when generating polymer libraries (e.g., 4.5× faster for 96 polymethacrylates and 20× faster for 45 for polycarbonates). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 49–58, 2009     

A field deployable method for a rapid screening analysis of inorganic arsenic in seaweed

Inorganic arsenic (iAs) in 13 store-bought edible seaweed samples and 34 dried kelp (Laminaria digitata) samples was determined by a newly developed, field-deployable method (FDM) with the aid of a field test kit for arsenic in water. Results from the FDM were compared to results from speciation analysis achieved by using high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The FDM consisted of a simple extraction method using diluted HNO₃ to quantitatively extract iAs without decomposing the organoarsenicals to iAs followed by the selective volatilisation of iAs as arsine (AsH₃) and subsequent chemo-trapping on a filter paper soaked in mercury bromide (HgBr₂) solution. Method optimization with a sub-set of samples showed 80–94% iAs recovery with the FDM with no matrix effect from organo-arsenic species in the form of dimethylarsinic acid (DMA) on the iAs concentration. The method displayed good reproducibility with an average error of ±19% and validation by HPLC-ICP-MS showed that the results from the FDM were comparable (slope = 1.03, R² = 0.70) to those from speciation analysis with no bias. The FDM can be conducted within an hour and the observed limit of quantification was around 0.05 mg kg^?1 (dry weight). This method is well suited for on-site monitoring of iAs in seaweed before it is harvested and can thus be recommended for use as a screening method for iAs in seaweed.

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Graphical abstract Screening seaweed for their inorganic arsenic concentration within one hour without bias has been made possible in the field by using a field deployable arsenic kit. Its accuracy and precision was compared to HPLC-ICPMS.

     

Effective Approximation for the Semiclassical Schrödinger Equation

The computation of the semiclassical Schrödinger equation presents major challenges because of the presence of a small parameter. Assuming periodic boundary conditions, the standard approach consists of semi-discretisation with a spectral method, followed by an exponential splitting. In this paper we sketch an alternative strategy. Our analysis commences with the investigation of the free Lie algebra generated by differentiation and by multiplication with the interaction potential: it turns out that this algebra possesses a structure which renders it amenable to a very effective form of asymptotic splitting: exponential splitting where consecutive terms are scaled by increasing powers of the small parameter. This leads to methods which attain high spatial and temporal accuracy and whose cost scales as \({\mathcal {O}}\!\left( M\log M\right) \) , where \(M\) is the number of degrees of freedom in the discretisation.     

Occurrence and Characteristics of Staphylococcus aureus Isolated from Dairy Products

Food, particularly milk and cheese, may be a reservoir of multi-drug resistant Staphylococcus aureus strains, which can be considered an important issue in terms of food safety. Furthermore, foods of animal origin can be a cause of staphylococcal food poisoning via the production of heat-stable enterotoxins (SE). For this reason, we investigated the prevalence of and characterized Staphylococcus aureus strains isolated from milk and fresh soft cheese obtained from farms located in Wielkopolskie and Zachodniopomorskie Provinces in Poland. Overall, 92% of S. aureus isolates were positive for at least one of the 18 enterotoxin genes identified, and 26% of the strains harbored 5 to 8 enterotoxin genes. Moreover, the S. aureus strains contained genes conferring resistance to antibiotics that are critically important in both human and veterinary medicine, i.e., β-lactams (mecA), aminoglycosides (aac(6′)/aph(2″), aph(3′)-IIIa, ant(4′)-Ia) and MLS_B (erm(A), msr(A), lun(A)). The antimicrobial susceptibility of S. aureus to 16 antibiotics representing 11 different categories showed that 74% of the strains were resistant to at least 1 antibiotic. Moreover, 28% of the strains showed multidrug resistance; in particular, two methicillin-resistant S. aureus strains (MRSA) exhibited significant antibiotic resistance. In summary, our results show that dairy products are contaminated by S. aureus strains carrying genes encoding a variety of enterotoxins as well genes conferring resistance to antibiotics. Both MRSA strains and MSSA isolates showing multidrug resistance were present in foods of animal origin.     

Polarographic and voltammetric determination of trace amounts of 2-nitronaphthalene

The polarographic behaviour of 2-nitronaphthalene was investigated by DC tast polarography (DCTP) and differential pulse polarography (DPP), both at a dropping mercury electrode, and differential pulse voltammetry and adsorptive stripping voltammetry, both at a hanging mercury drop electrode. Optimum conditions have been found for the determination of 2-nitronaphthalene by the given methods in the concentration ranges of 2×10^–6–1×10^–4, 2×10^–7–1×10^–4, 1×10^–8–1×10^–4 and 2×10^–9–1×10^–8 M, respectively. Practical applicability of these techniques was demonstrated by the determination of 2-nitronaphthalene in drinking and river water after its preliminary separation and preconcentration using liquid–liquid and solid-phase extraction with limits of determination of 3×10^–10 M (drinking water) and 3×10^–9 M (river water).