Biotechnological H2S gas treatment with Thiobacillus ferrooxidans

In this paper a novel process for biotechnological abatement of hydrogen sulphide is presented which details the fundamentals of chemical and biological phenomena involved. The process is based on the combination of two steps to form a closed cycle which has special enviornmental advantages. The chemical step corresponds to the abatement reaction itself with absorption of the gas in a ferric solution. The biological step is related to the regeneration of the absorbing solution by means of specific bacterial strains. Particular interest is devoted to the biological kinetics of the regeneration stage, where several inhibition phenomena appear, and are also related to parameters such as temperature and pH. Results of experimental runs of gas absorption in a laboratory scale plant are also described.     

Experience over time: evaluating the experience of use of a squeezable interface in the medium term

The paper presents the user experience evaluation of Squeeze Me, an interactive cover for tablet and smartphone that enables continuous and expressive interaction with electronic devices. The cover has been used to implement ”Squeeze to zoom”, a mobile application to zoom in and out while taking a photograph from a tablet. The experience of use was evaluated in the short and medium term, comparing the Squeeze Me interaction modality with classic modalities for zooming in and out commonly available on tablets and smartphones. The evaluation process was conducted using AttrakDiff [3] a questionnaire that measures hedonic stimulation and identity, as well as pragmatic qualities and attractiveness of software products. Participants were asked to try out different interaction modalities for comparison in the short-term (67 people) and over 4 weeks (8 people). Results obtained in the short-term evaluation reveal that “Squeeze to zoom” was awarded higher values than the classic “Slide to zoom” in the hedonic quality-stimulation and attractiveness dimensions, whilst it obtained lower values in the pragmatic quality and hedonic quality-identity. However, the experience of use changed over time. During the longitudinal study, the usability of “Squeeze to zoom” improved whilst the attractiveness of “Slide to zoom” decreases significantly. Furthermore results reveal that “Squeeze to zoom” is significantly more appreciated for its hedonic qualities and the effect is maintained over time. This study highlights the importance of evaluating the experience of use over time, a practice that is almost ignored in the literature on Experience Design.     

Low-Temperature Synthesis and Properties of LaMnO3±d and La0.67R0.33MnO3±d (R = Ca, Sr, Ba) from Citrate Precursors

LaMn_{1− y} ³⁺Mn _y ⁴⁺O_3±d and La_0.67R_0.33Mn_{1− y} ³⁺Mn _y ⁴⁺O_3±d (R = Ca, Sr, Ba) phases were synthesized at 350°C by using very reactive, amorphous precursors obtained from the stoichiometric citrate solutions. The chemical process was optimized with respect to the solution concentration, pH, and additives. The precursor reactions were investigated as a function of the cation stoichiometry and the additive by simultaneous thermal and thermogravimetric analysis and X-ray diffraction. The reaction pathway was found to be independent of the cation stoichiometry, but related to the acid or base additive. The annealing temperature was systematically increased in the 350–1200°C interval and the La_0.67Sr_0.33MnO_3±d properties (i.e., crystal sizes, Mn average valence, Curie temperature, magnetization, magnetic susceptibility) were measured and found to vary consistently as a function of it.     

Three-dimensional image restoration and super-resolution in fluorescence confocal microscopy

Confocal scanning laser microscopy (CSLM) provides optical sectioning of a fluorescent sample and improved resolution with respect to conventional optical microscopy. As a result, three-dimensional (3-D) imaging of biological objects becomes possible. A difficulty is that the lateral resolution is better than the axial resolution and, thus, the microscope provides orientation-dependent images. However, a theoretical investigation of the process of image formation in CSLM shows that it must be possible to improve the resolution obtained in practice. We present two methods for achieving such a result in the case of 3-D fluorescent objects. The first method applies to conventional CSLM, where the image is detected only on the optical axis for any scanning position. Since the resulting 3-D image is the convolution of the object with the impulse-response function of the instrument, the problem of image restoration is a deconvolution problem and is affected by numerical instability. A short introduction to the linear methods developed for obtaining stable solutions of these problems (the so-called regularization theory of ill-posed problems) is given and an application to a real image is discussed. The second method applies to a new version of CSLM proposed in recent years. In such a case the full image must be measured by a suitable array of detectors. For each scanning position the data are not single numbers but vectors. Then, in order to recover the object, one must solve a Fredholm integral equation of the first kind. A method for the solution of this equation is presented and the possibility of achieving super-resolution is demonstrated. More precisely, we show that it is possible to improve by about a factor of 2 the resolution of conventional CSLM both in the lateral and axial directions.     

Physical properties of 2-hydroxyethyl methacrylate-grafted silk fibers

This paper deals with the physical properties of silk fibers grafted with 2-hydroxyethyl methacrylate (HEMA). Both tensile strength and elongation measured in the dry and wet states gradually decreased with increasing weight gain. The initial modulus of the grafted silk fibers in the dry state sharply increased in the weight gain range of 0–16%, then decreased to a lower value than the reference untreated sample. The refractive indices parallel and perpendicular to the fiber axis decreased, though the former showed a steeper slope. Accordingly, birefringence and isotropic refractive index also decreased, suggesting a lower degree of crystallinity and molecular orientation of grafted silk fibers. DSC, TMA, and TGA curves of the HEMA-grafted silk fibers indicated an increased higher thermal stability of silk fibers due to the HEMA grafting. The dynamic mechanical measurements showed that the thermally induced molecular movement of both amorphous and crystalline domains of silk fibers was enhanced by HEMA grafting. X-ray diffraction curves, however, implied that the crystalline structure of the silk fibroin remained unchanged regardless of HEMA polymerization. The introduction of HEMA polymer in silk fibers was evidenced by the infrared spectra, exhibiting the absorption bands characteristic of either the grafted HEMA polymer and the fibroin molecules with ordered β structure. © 1993 John Wiley & Sons, Inc.     

ERAP1 and ERAP2 Enzymes: A Protective Shield for RAS against COVID-19?

Patients with coronavirus disease 2019 (COVID-19) have a wide variety of clinical outcomes ranging from asymptomatic to severe respiratory syndrome that can progress to life-threatening lung lesions. The identification of prognostic factors can help to improve the risk stratification of patients by promptly defining for each the most effective therapy to resolve the disease. The etiological agent causing COVID-19 is a new coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that enters cells via the ACE2 receptor. SARS-CoV-2 infection causes a reduction in ACE2 levels, leading to an imbalance in the renin-angiotensin system (RAS), and consequently, in blood pressure and systemic vascular resistance. ERAP1 and ERAP2 are two RAS regulators and key components of MHC class I antigen processing. Their polymorphisms have been associated with autoimmune and inflammatory conditions, hypertension, and cancer. Based on their involvement in the RAS, we believe that the dysfunctional status of ERAP1 and ERAP2 enzymes may exacerbate the effect of SARS-CoV-2 infection, aggravating the symptomatology and clinical outcome of the disease. In this review, we discuss this hypothesis.     

Synthesis and antitumor activity of 3-(2-phenyl-1,3-thiazol-4-yl)-1H-indoles and 3-(2-phenyl-1,3-thiazol-4-yl)-1H-7-azaindoles

Given the potent antimicrobial, antiviral, and antitumor activities of many natural products, there is an increasing interest in the synthesis of new molecules based on natural compound scaffolds. Based on a 2,4-bis(3'-indolyl)imidazole skeleton, two new series of phenylthiazolylindoles and phenylthiazolyl-7-azaindoles were obtained by Hantzsch reaction between substituted phenylthioamides and the α-bromoacetyl derivatives. Some azaindole derivatives, tested at the National Cancer Institute against a panel of ～60 tumor cell lines derived from nine human cancer cell types, showed inhibitory effects against all cell lines investigated at micromolar to nanomolar concentrations. Two of them exhibited a high affinity for CDK1, with IC(50) values of 0.41 and 0.85 μM. These promising results will set the foundation for future investigations into the development of anticancer therapies.