MoOx/Ag/MoOx multilayers as hole transport transparent conductive electrodes for n-type crystalline silicon solar cells

Substitution of highly doped layers with conventional transparent conductive electrodes as carrier collecting and selective contacts in conventional crystalline silicon (c-Si) solar cell configurations is crucial in increasing affordability of solar cells by lowering material costs. In this study, oxide/metal/oxide (OMO) multilayers featuring molybdenum oxide (MoO_x) and silver (Ag) thin films are developed by thermal evaporation technique, as dopant-free hole transport transparent conductive electrodes (HTTCEs) for n-type c-Si solar cells. Semidopant-free asymmetric heterocontact (semi-DASH) solar cells on n-type c-Si utilizing OMO multilayers are fabricated. The effect of outer MoO_x layer thickness and Ag deposition rate on the photovoltaic characteristics of the fabricated semi-DASH solar cells are investigated. A comparison of front side pyramid textured and flat surface solar cells is performed to optimize the optical and electrical properties. Highest efficiency of 9.3% ± 0.2% is achieved in a pyramid textured semi-DASH c-Si solar cell with 15/10/30 nm of HTTCE structure.     

Rheological properties and crystallization behavior of modified polylactic acid using lauroyl peroxide and glycidyl methacrylate

The molecular structure of polylactic acid (PLA) was modified by lauroyl peroxide (LP) as an alkyl free radical and glycidyl methacrylate (GMA) as a reactive co-monomer. We investigated the effect of different preparation methods, that is, the melt and solution, on the structure and physical and mechanical properties of glycidyl methacrylate grafted polylactic acid (PLA-g-GMA). The Fourier transformed infrared spectroscopy (FTIR) was implemented to characterize the final products in order to confirm that GMA was successfully grafted onto PLA. The gel permeation chromatography showed that the molecular weight and polydispersity of the modified PLA were increased by grafting. However, by varying other parameters such as the reaction time and the LP and GMA concentrations, we observed that the resulting products from the melt method are richer in the rheological properties compared with those properties from the solution method. This is due to the different molecular weights resulted from the either preparation methods. From the DSC characteristics of PLA-g-GMA samples, the crystallization degree of the samples prepared from the melt method is greater than that of the solution method. Meanwhile, the cold crystallization for the PLA-g-GMA samples derived from the solution method occurs at higher temperatures compared with the cold crystallization of the samples resulted from the melt method.     

A Bioinformatics Systems Biology Analysis of the Current Oral Proteomic Biomarkers and Implications for Diagnosis and Treatment of External Root Resorption

External root resorption (ERR) is a silent destructive phenomenon detrimental to dental health. ERR may have multiple etiologies such as infection, inflammation, traumatic injuries, pressure, mechanical stimulations, neoplastic conditions, systemic disorders, or idiopathic causes. Often, if undiagnosed and untreated, ERR can lead to the loss of the tooth or multiple teeth. Traditionally, clinicians have relied on radiographs and cone beam computed tomography (CBCT) images for the diagnosis of ERR; however, these techniques are not often precise or definitive and may require exposure of patients to more ionizing radiation than necessary. To overcome these shortcomings, there is an immense need to develop non-invasive approaches such as biomarker screening methods for rapid and precise diagnosis for ERR. In this review, we performed a literature survey for potential salivary or gingival crevicular fluid (GCF) proteomic biomarkers associated with ERR and analyzed the potential pathways leading to ERR. To the best of our knowledge, this is the first proteomics biomarker survey that connects ERR to body biofluids which represents a novel approach to diagnose and even monitor treatment progress for ERR.     

Chemical Space Overlap with Critical Protein–Protein Interface Residues in Commercial and Specialized Small-Molecule Libraries

There is growing interest in the use of structure-based virtual screening to identify small molecules that inhibit challenging protein–protein interactions (PPIs). In this study, we investigated how effectively chemical library members docked at the PPI interface mimic the position of critical side-chain residues known as “hot spots”. Three compound collections were considered, a commercially available screening collection (ChemDiv), a collection of diversity-oriented synthesis (DOS) compounds that contains natural-product-like small molecules, and a library constructed using established reactions (the “screenable chemical universe based on intuitive data organization”, SCUBIDOO). Three different tight PPIs for which hot-spot residues have been identified were selected for analysis: uPAR⋅uPA, TEAD4⋅Yap1, and Ca_Vα⋅Ca_Vβ. Analysis of library physicochemical properties was followed by docking to the PPI receptors. A pharmacophore method was used to measure overlap between small-molecule substituents and hot-spot side chains. Fragment-like conformationally restricted small molecules showed better hot-spot overlap for interfaces with well-defined pockets such as uPAR⋅uPA, whereas better overlap was observed for more complex DOS compounds in interfaces lacking a well-defined binding site such as TEAD4⋅Yap1. Virtual screening of conformationally restricted compounds targeting uPAR⋅uPA and TEAD4⋅Yap1 followed by experimental validation reinforce these findings, as the best hits were fragment-like and had few rotatable bonds for the former, while no hits were identified for the latter. Overall, such studies provide a framework for understanding PPIs in the context of additional chemical matter and new PPI definitions.     

Piecemeal Learning of an Unknown Environment

We introduce a new learning problem: learning a graph bypiecemeal search, in which the learner must return every so often to its starting point (for refueling, say). We present two linear-time piecemeal-search algorithms for learningcity-block graphs: grid graphs with rectangular obstacles.     

Reduction of aqueous carbonate photocatalysed by treated semiconductors

Heterogeneous photocatalysed reduction of aqueous Na₂CO₃ solution (1 m) was achieved by using phthalocyanine-coated semiconductor powders (1–3% coating) as well as bare semiconductors. The suspensions were irradiated with 254 nm light from a low-pressure mercury lamp in a nitrogen atmosphere. The phthalocyanine dyes (Fe²⁺-Pc or Co²⁺-Pc) absorb > 80% of the 254 nm radiation and thus sensitize the semiconductor. The products of reduction (CH₃OH and HCHO) were determined spectrophotometrically. The CH₃OH yields obtained are much higher than the HCHO yields, due to a photocatalysed reduction of HCHO to CH₃OH. The CH₃OH yields from coated titania increased linearly with irradiation time over the period 6–18 h. However, the straight line does not pass through the origin, and it seems that a slowing-down occurs at times > 6 h. Titania coated with both dyes gave an optimum CH₃OH yield at 2% surface coating. At higher coating percentages, phthalocyanine screens the surface, thus reducing the light reaching the semiconductor. Changing the redox potential of the phthalocyanine dye by changing its central metal from Fe to Co affects the CH₃OH yields. The bare MoS₂ photocatalyst gave a much higher CH₃OH yield due to the characteristic behaviour of the semiconducting layer-type disulphide, distinguished from that of classical semiconducting materials. In the various semiconductors studied, it seems that there is no correlation between the position of the conduction band and the yield of CH₃OH. Such correlation was argued. Generally, a decrease in the yield of CH₃OH was observed as the band gap width of the semiconductor increased. The yields of the photoproduced CH₃OH generally increased with the percentage of light absorbed at 254 nm by the various semiconductors. Irradiation leads to the production of electrons in the conduction band of the semiconductor. It is likely that the photoproduced electrons reduce CO₃²- initially to HCOO- and then to HCHO and CH₃OH.     

Coping with adults' angry behavior: Behavioral, physiological, and verbal responses in preschoolers.

This study replicated and extended a study of Cummings (1987) by examining 4- and 5-year-olds' behavioral and verbal responses to adults' angry behavior and collected data on physiological responses. We found behavioral and verbal responses of distress and that systolic blood pressure increased in response to anger. As in Cummings (1987), children's behavioral emotional responses to anger predicted other aspects of responding. Angry/ambivalent children showed a complex heart rate pattern, including a decrease with the onset of anger, whereas heart rate increased in response to anger for concerned/distressed children. Both groups reported more emotional distress (mostly anger) than unresponsive children, and angry–ambivalent children reported the most nonplay responses (e.g., leave, mediate). The results provide more support for discrete patterns of responding to adults' angry emotions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gamma irradiation of (styrene butadiene rubber)/(devulcanized waste rubber) blends modified by organoclay

In this study, the physicomechanical properties and morphology evolution of irradiated (styrene butadiene rubber)/(devulcanized waste rubber)/(organically modified montmorillonite) nanocomposites were realized. The improvement in the physicomechanical properties provides a possible mechanism on how organically modified montmorillonite influences the general properties of irradiated nanocomposites. X‐ray diffraction data illustrated that there is an increase in the basal spacing of sodium montmorillonite clay due to modification and/or polymer intercalation. The results of mechanical properties showed that the as‐prepared nanocomposites have superior irradiation‐resistant properties to the (styrene butadiene rubber)/(devulcanized waste rubber) blend. J. VINYL ADDIT. TECHNOL., 24:50–57, 2018. © 2015 Society of Plastics Engineers     

Production of Well-Dispersed Aqueous Cross-Linked Chitosan-Based Nanomaterials as Alternative Antimicrobial Approach

In the current study, chitosan was extracted by deacetylation of chitin, which is extracted from shrimp shell. chitosan nanoparticles (CSNPs) were prepared by ionotropic gelation technique. chitosan/tripolyphosphate ratio (CS:TPP) was kept at 3:1 to prepare CSNPs. chitosan/silver nanocomposite (CS/AgNCs) were prepared by incorporating silver nanoparticles into CSNPs. The quality of the prepared nanocomposite was evaluated by infrared spectroscopy, UV–Vis spectroscopy, transmission electron microscopy, and antibacterial activity. Results showed that chitosan/silver nanocomposite in which, both chitosan and silver are in nanoscale was successfully prepared for the first time in a well-dispersed aqueous form. Whereas CSNPs act as a host material to form the nanocomposite unlike the previously prepared forms of chitosan–silver nanocomposites, that used chitosan bulk as host materials and the dispersion medium was slightly acidic. Moreover, results revealed that the antibacterial activity of CSNPs was significantly enhanced after incorporating trace amount of silver nanoparticles (0.535% w/w AgNPs/CSNPs).