A monolithically integrated high‐efficiency Cu(In,Ga)Se2 mini‐module structured solely by laser

Monolithically integrated Cu(In,Ga)Se₂ mini‐modules were fabricated in order to reduce the width of patterning related dead area. The Cu(In,Ga)Se₂ layers were prepared on soda‐lime glasses using the multistage process at low substrate temperature below 500 °C. A picosecond laser with a wavelength of 532 nm was used for all of the structuring processes (P1, P2, and P3) for the monolithic integration. A “lift‐off” type structuring was applied for P1 and P3, and an “ablation” type was for P2. The laser structuring was optimized to be minimizing the dead area width, and the width of about 70 µm was successfully achieved. A mini‐module, in which the optimized structuring processes were applied for the integration, demonstrated a certified efficiency of 16.6%. Copyright © 2015 John Wiley & Sons, Ltd.     

Investigation of the Sharkskin melt instability using optical Fourier analysis

An optical method allowing the characterization of melt flow instabilities typically occurring during an extrusion process of polymers and polymer compounds is presented. It is based on a camera-acquired image of the extruded compound with a reference length scale. Application of image processing and transformation of the calibrated image to the frequency domain yields the magnitude spectrum of the instability. The effectiveness of the before mentioned approach is shown on Styrene-butadiene rubber (SBR) compounds, covering a wide range of silica filler content, extruded through a Göttfert capillary rheometer. The results of the image-based analysis are compared with the results from the sharkskin option, a series of highly sensitive pressure transducers installed inside the rheometer. A simplified version of the code used to produce the optical analysis results is included as supplementary material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48806.     

Biosynthetic Plasticity Enables Production of Fluorinated Aurachins

Enzyme promiscuity has important implications in the field of biocatalysis. In some cases, structural analogues of simple metabolic building blocks can be processed through entire pathways to give natural product derivatives that are not readily accessible by chemical means. In this study, we explored the plasticity of the aurachin biosynthesis pathway with regard to using fluoro- and chloroanthranilic acids, which are not abundant in the bacterial producers of these quinolone antibiotics. The incorporation rates of the tested precursor molecules disclosed a regiopreference for halogen substitution as well as steric limitations of enzymatic substrate tolerance. Three previously undescribed fluorinated aurachin derivatives were produced in preparative amounts by fermentation and structurally characterized. Furthermore, their antibacterial activities were evaluated in comparison to their natural congener aurachin D.     

Theophylline: Old Drug in a New Light,Application in COVID-19 through Computational Studies

Theophylline (3-methyxanthine) is a historically prominent drug used to treat respiratory diseases, alone or in combination with other drugs. The rapid onset of the COVID-19 pandemic urged the development of effective pharmacological treatments to directly attack the development of new variants of the SARS-CoV-2 virus and possess a therapeutical battery of compounds that could improve the current management of the disease worldwide. In this context, theophylline, through bronchodilatory, immunomodulatory, and potentially antiviral mechanisms, is an interesting proposal as an adjuvant in the treatment of COVID-19 patients. Nevertheless, it is essential to understand how this compound could behave against such a disease, not only at a pharmacodynamic but also at a pharmacokinetic level. In this sense, the quickest approach in drug discovery is through different computational methods, either from network pharmacology or from quantitative systems pharmacology approaches. In the present review, we explore the possibility of using theophylline in the treatment of COVID-19 patients since it seems to be a relevant candidate by aiming at several immunological targets involved in the pathophysiology of the disease. Theophylline down-regulates the inflammatory processes activated by SARS-CoV-2 through various mechanisms, and herein, they are discussed by reviewing computational simulation studies and their different applications and effects.     

Microbiological, epidemiological, and food safety aspects of Enterobacter sakazakii

Enterobacter sakazakii is considered to be an opportunistic pathogen and has been implicated in foodborne diseases causing meningitis or enteritis, especially in neonates and infants. The U.S FoodNet 2002 survey rate of invasive infections with this organism in infants under 1 year of age was 1 per 100,000 infants. Severity of the disease is a matter of concern. In a recent study on the occurrence of E. sakazakii in production environments from food (milk powder, chocolate, cereal, potato, and pasta) factories and households, this organism was isolated with varying frequency from nearly all environments examined, strongly indicating that it is widespread. Stationary phase E. sakazakii cells are remarkably resistant to osmotic and drying stresses compared with other species of the Enterobacteriacae. In this article, we review the literature on this organism with special respect to the information relevant for food safety.     

Germin-like protein Cit s 1 and profilin Cit s 2 are major allergens in orange (Citrus sinensis) fruits

Oranges are clinically relevant allergenic foods. To date, orange allergens have not been characterized in detail. The study is aimed at analyzing the sensitization profile in orange-sensitized subjects with and without clinical allergy, and to identify orange allergens. Fifty-six sensitized subjects with self-reported reactions to orange were grouped into reactors (anaphylaxis or multiple episodes of immediate reactions and/or positive challenge tests) and non-reactors (negative open food challenge tests). Allergens were characterized by IgE immunoblotting, N-terminal sequencing, IgE-inhibition assays, and mediator release assays were performed to determine the allergenic potency of orange profilin. Of 56 subjects, 23 were classified as orange allergic showing mainly an oral allergy syndrome. Of 23 subjects classified as orange allergic, 22 were sensitized to profilin, Cit s 2. In patients with mono-sensitization to profilin in vitro histamine releases up to 75% from basophils were induced using orange extract and purified plant profilins. Of the allergic patients 78% were sensitized to germin-like protein, Cit s 1. Both allergens showed retained IgE reactivity in heat-processed orange juice. Interestingly, subjects with and without clinical allergy showed a comparable sensitization profile. Profilin and germin-like proteins are major orange allergens. The potential clinical relevance of orange profilin was indicated by its strong capacity to release histamine from basophils. However, a predominant sensitization to both allergens in subjects without symptoms also indicates a high frequency of clinically insignificant sensitization.     

Escherichia coli O157 and non-O157 Shiga toxin-producing Escherichia coli in fecal samples of finished pigs at slaughter in Switzerland

Fecal samples from 630 slaughtered finisher pigs were examined by PCR to assess the shedding of Escherichia coli O157 (rfbE) and Shiga toxin-producing E. coli (STEC, stx). The proportion of positive samples was 7.5% for rfbE and 22% for stx. By colony hybridization, 31 E. coli O157 and 45 STEC strains were isolated, and these strains were further characterized by phenotypic and genotypic traits. Among E. coli O157 strains, 30 were sorbitol positive, 30 had an H type other than H7, and none harbored stx genes. Intimin (eae), enterohemolysin (ehxA), EAST1 (astA), and porcine A/E-associated protein (paa) were present in 10, 3, 26, and 6% of strains. Among them, one eae-gamma1-positive O157:H7 strain testing positive for ehxA and astA and two eae-alpha1-positive O157:H45 strains were classified as enteropathogenic E. coli (EPEC). The O157:H45 EPEC harbored the EAF plasmid and the bfpA gene, factors characteristic for typical EPEC. The isolated STEC strains (43 sorbitol positive) belonged to 11 O:H serotypes, including three previously reported in human STEC causing hemolytic uremic syndrome (O9:H-, O26:H-, and O103:H2). All but one strain harbored stx2e. The eae and ehxA genes, which are strongly correlated with human disease, were present in only one O103:H2 strain positive for stx1 and paa, whereas the astA gene was found more frequently (14 strains). High prevalence of STEC was found among finisher pigs, but according to the virulence factors the majority of these strains seem to be of low virulence.     

Lipoxygenase Products in the Urine Correlate with Renal Function and Body Temperature but not with Acute Transplant Rejection

Acute transplant rejection is the leading cause of graft loss in the first months after kidney transplantation. Lipoxygenase products mediate pro- and anti-inflammatory actions and thus we aimed to correlate the histological reports of renal transplant biopsies with urinary lipoxygenase products concentrations to evaluate their role as a diagnostic marker. This study included a total of 34 kidney transplant recipients: 17 with an acute transplant rejection and 17 controls. LTE4, LTB4, 12-HETE and 15-HETE concentrations were measured by enzyme immunoassay. Urinary lipoxygenase product concentrations were not significantly changed during an acute allograft rejection. Nevertheless, LTB4 concentrations correlated significantly with the body temperature (P ≤ 0.05) 3 months after transplantation, and 12- and 15-HETE concentrations correlated significantly with renal function (P ≤ 0.05) 2 weeks after transplantation. In conclusion, our data show a correlation for LTB4 with the body temperature 3 months after transplantation and urinary 12- and 15-HETE concentrations correlate positively with elevated serum creatinine concentrations but do not predict acute allograft rejection.     

Relevant aspects of Arcobacter spp. as potential foodborne pathogen

Arcobacter species are Gram-negative spiral-shaped organisms belonging to the family Campylobacteraceae that can grow microaerobically or aerobically. The Arcobacter organisms also have the ability to grow at 15 degrees C, which is a distinctive feature that differentiates Arcobacter species from Campylobacter species. Cultural detection of Arcobacter is generally performed by an enrichment step and takes 4 to 5 days. In the last few years, several studies comparing different culture-based protocols have been published. Furthermore, DNA-based assays have also been established for rapid and specific identification of Arcobacter spp. Recent evidence suggests that Arcobacter, especially A. Butzleri, may be involved in human enteric diseases. Moreover, A. butzleri has also occasionally been found in cases of human extraintestinal diseases. However, up to now, little is known about the mechanisms of pathogenicity or potential virulence factors of Arcobacter spp. There is evidence that livestock animals may be a significant reservoir of Arcobacter spp. and over the last few years, the presence of these organisms in raw meat products as well as in surface and ground water has received increasing attention. In view of control measures to be used to prevent or to eliminate the hazard of Arcobacter spp. in food, several treatments have been evaluated for their effectiveness. While the role of Arcobacter spp. in human disease awaits further evaluation, a precautionary approach is advisable. Measures aimed at reduction or eradication of Arcobacter from the human food chain should be encouraged. With this article, we review the recent literature on this organism with a special emphasis on the information relevant to food safety.     

Transition and flow boiling heat transfer inside a horizontal tube

Experiments on transition and flow boiling heat transfer with refrigerant R114 inside a horizontal tube were performed at bubble flow, critical heat flux and in the transition region between bubble flow and film boiling at mass fluxes between 1200 and 4000 kg/m² s and in the pressure range between 5 and 15 bar. In comparison with pool boiling bubble flow heat transfer depends essentially on the mass flow rates and on the vapor quality. The critical heat flux depends less on the temperature difference than in pool boiling heat transfer and exhibits a maximal and a minimal value as a function of the pressure. The critical heat flux increases with mass flow rate as already shown by Collier. In the region of transition boiling the heat flux over the difference between wall and saturation temperature approaches a horizontal curve. Therefore in this region an evaporator may always be operated under stable conditions and burn out does not occur.