Review—Recent Developments in the Applications of 2D Transition Metal Dichalcogenides as Electrocatalysts in the Generation of Hydrogen for Renewable Energy Conversion

There has never been a more pressing need to develop sustainable energy systems as dramatic climate changes emerge across the World. Some of these effects can be alleviated by the development of efficient devices that are capable of producing hydrogen gas in an environmentally acceptable manner, which in turn can be employed as a clean fuel. In this context, the splitting of water is especially attractive. However, this technology requires the design of new cost-effective electrocatalytic materials. In this review, the progress made in the development of transition metal dichalcogenides (TMDs) and their composites as electrocatalysts for both acidic and alkaline electrolysis cells and as photocatalysts for the formation of hydrogen is described and discussed. Following a short introduction to the mechanisms of the electrochemical hydrogen and oxygen evolution reactions and the photoelec- trochemical generation of hydrogen, an introduction to TMDs, their relevant general properties and the methods used in their synthesis are described. Then, the performance of various TMD-based materials in the electrochemical splitting of water is discussed, with a final brief overview of the application of TMDs in photoelectrochemical devices. Although challenges clearly remain, TMD-based materials are emerging as promising electrocatalysts and photoelectrocatalysts for the production of hydrogen. © 2022 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/ by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cite

An endophyte Paenibacillus dendritiformis strain APL3 promotes Amaranthus polygonoides L. sprout growth and their extract inhibits food-borne pathogens

Green leafy vegetables are rich sources of antioxidants and minerals, which prevent food-borne pathogen infections during our diet. This study was aimed to isolate and identify the plant growth-promoting endophytic bacterium from several plant species to enhance the growth of Amaranthus polygonoides L. and their antimicrobial potential against food-borne pathogens. Seven endophytic bacterial isolates were tested on two Amaranthus species to identify the suitable beneficial bacterium. The antioxidants capacity and antimicrobial activity of bacterial isolate (APL3) treated plants were analyzed. The bacterial isolate, APL3 showed a significantly higher growth of A. polygonoides L. than other isolates. It was identified as Paenibacillus dendritiformis strain APL3 by 16S rRNA gene sequencing and phylogenetic analysis. The endophyte (APL3) treated A. polygonoides L. sprouts had higher antioxidants potentials and significantly inhibited the growth of Escherichia coli, Salmonella sp., Staphylococcus sp. and Pseudomonas sp. The results of the present study suggest that utilization of P. dendritiformis strain APL3 triggers the growth of A. polygonoides L. and induces metabolic changes in plants to improve their antimicrobial properties to prevent foodborne pathogens

Insight into the synergistic effect of 2D/2D layered metal selenides wrapped nickel boride nanoparticles based ternary heterostructure for constructing asymmetric supercapacitors with excellent energy density

Tuning the structural and electronic properties of layered metal selenides is a highly feasible approach for developing high-performance asymmetric supercapacitors (ASCs). In this work, a ternary heterostructure of yttrium diselenide/molybdenum diselenide (YSe2/MoSe2) with amorphous nickel boride nanoparticles (NixB NPs) was prepared by a simple hydrothermal method followed by a liquid phase route. Interestingly, this ternary heterostructure consists of multiple layers of YSe2/MoSe2 nanosheets uniformly wrapped by NixB NPs over the entire surface. The characterization results by X-ray diffraction, Raman, and X-ray photoelectron spectroscopy showed that the strong synergism between YSe2/MoSe2 and NixB NPs indicates an obvious electron transfer from NixB to the YSe2/MoSe2 hybrid, which contributes to the enhancement of the electrical conductivity of the electrode. Due to its exclusive heterostructure network, the single YSe2/MoSe2/NixB electrode achieved a specific capacitance of 893.3 F/g at 1 A/g and a capacity retention of 128.17% over 5000 cycles. In addition, the asymmetric YSe2/MoSe2/NixB||rGO device with a working potential of 1.6 V showed an impressive energy density of 39.5 Wh kg− 1 with a power density of 800 W kg− 1 and excellent cycling stability with 85.60% capacity retention after 5000 cycles in aqueous electrolyte. This result of the designed ASC device encourages the development of a new platform for the design of electrode materials based on metal selenides and metal boride

Histone citrullination represses miRNA expression resulting in increased oncogene mRNAs in somatolactotrope cells.

Peptidylarginine deiminase (PAD) enzymes convert histone arginine residues into citrulline to modulate chromatin organization and gene expression. Although PADs are expressed in anterior pituitary gland cells, their functional role and expression in pituitary adenomas is unknown. To begin to address these questions, we first examined normal human pituitaries and pituitary adenomas and found that PAD2, PAD4 and citrullinated histones are highest in prolactinomas and somatoprolactinomas. In the somatoprolactinoma-derived GH3 cell line, PADs citrullinate histone H3, which is attenuated by a pan-PAD inhibitor. RNA-sequencing and ChIP studies show that the expression of microRNAs let-7c-2, miR-23b and miR-29c is suppressed by histone citrullination. Our studies demonstrate that these miRNAs directly target the mRNA of the oncogenes HMGA, IGF-1 and N-MYC, which are highly implicated in human prolactinoma/somatoprolactinoma pathogenesis. Our results are the first to define a direct role for PAD catalyzed histone citrullination in miRNA expression, which may underlie the etiology of prolactinoma and somatoprolactinoma tumors through regulation of oncogene expression

Pilot Study Comparing Closed Versus Open Tracheal Suctioning in Postoperative Neonates and Infants With Complex Congenital Heart Disease

Objectives: To determine the hemodynamic effect of tracheal suction method in the first 36 hours after high-risk infant heart surgery on the PICU and to compare open and closed suctioning techniques. Design: Pilot randomized crossover study. Setting: Single PICU in United Kingdom. Participants: Infants undergoing surgical palliation with Norwood Sano, modified Blalock-Taussig shunt, or pulmonary artery banding in the first 36 hours postoperatively. Interventions: Infants were randomized to receive open or closed (in-line) tracheal suctioning either for their first or second study tracheal suction in the first 36 hours postoperatively. Measurements and Main Results: Twenty-four infants were enrolled over 18 months, 11 after modified Blalock-Taussig shunt, seven after Norwood Sano, and six after pulmonary artery banding. Thirteen patients received the open suction method first followed by the closed suction method second, and 11 patients received the closed suction method first followed by the open suction method second in the first 36 hours after their surgery. There were statistically significant larger changes in heart rate (p = 0.002), systolic blood pressure (p = 0.022), diastolic blood pressure (p = 0.009), mean blood pressure (p = 0.007), and arterial saturation (p = 0.040) using the open suction method, compared with closed suctioning, although none were clinically significant (defined as requiring any intervention). Conclusions: There were no clinically significant differences between closed and open tracheal suction methods; however, there were statistically significant greater changes in some hemodynamic variables with open tracheal suctioning, suggesting that closed technique may be safer in children with more precarious physiology. (Pediatr Crit Care Med 2017; XX:00–00

Melt blending and characterization of carbon nanoparticles-filled thermoplastic polyurethane elastomers

In this work, thermoplastic polyurethane (TPU) elastomers reinforced with carbon nanosized particles were produced by a special melt blending technique. A TPU was melt blended with high-structured carbon black and carbon nanofibres (1 wt%). A miniature asymmetric batch mixer, which applies high shear levels to the melt, ensured good particles dispersion. The TPU material systems were then thoroughly characterized using thermogravimetric analysis, differential scanning calorimetry, tensile mechanical testing, electrical resistance measurements and flammability tests. The different nanofillers exhibited different influences on the TPU properties, these materials featuring interesting and improved multifunctional behaviours, with high propensity for large deformation sensors applications.This work was supported by FCT – Portuguese Foundation for Science and Technology through projects NANOSens – PTDC/CTM/73465/2006

A non-enzymatic amperometric hydrogen peroxide sensor based on iron nanoparticles decorated reduced graphene oxide nanocomposite

© 2016 Elsevier Inc. A simple and facile green process was used for the synthesis of iron nanoparticles (FeNPs) decorated reduced graphene oxide (rGO) nanocomposite by using Ipomoea pes-tigridis leaf extract as a reducing and stabilizing agent. The as-prepared rGO/FeNPs nanocomposite was characterized by transmission electron microscopy, X-ray spectroscopy and Fourier transform infrared spectroscopy. The nanocomposite was further modified on the glassy carbon electrode and used for non-enzymatic sensing of hydrogen peroxide (H2O2). Cyclic voltammetry results reveal that rGO/FeNPs nanocomposite has excellent electro-reduction behavior to H2O2 when compared to the response of FeNPs and rGO modified electrodes. Furthermore, the nanocomposite modified electrode shows 9 and 6 folds enhanced reduction current response to H2O2 than that of rGO and FeNPs modified electrodes. Amperometric method was further used to quantify the H2O2 using rGO/FeNPs nanocomposite, and the response was linear over the concentration ranging from 0.1 μM to 2.15 mM. The detection limit and sensitivity of the sensor were estimated as 0.056 μM and 0.2085 μA μM−1 cm−2, respectively. The fabricated sensor also utilized for detection of H2O2 in the presence of potentially active interfering species, and found high selectivity towards H2O2

Flower-like strontium molybdate anchored on 3D N-rich reduced graphene oxide aerogel composite: An efficient catalyst for the detection of lethal pollutant nitrobenzene in water samples

Nitrobenzene (NB) is a carcinogenic water pollutant that can have dangerous effects on humans, animals, and the environment even in trace amounts. It can persist in contaminated sites and leach into the adjacent aquatic environment. Therefore, the detection of trace amounts of NB is of great interest. To address this challenge, we have fabricated strontium molybdate microflowers (SrMoO4, SMO MFs) grown on nitrogen-rich, porous three-dimensional (3D) reduced graphene oxide aerogels (SMO/N-rGO) for sensitive detection of NB in water samples. The 3D N-rGO and SMO/N-rGO composites were prepared by simple hydrothermal and precipitation methods. The fabricated SMO/N-rGO composites exhibited a porous and 3D structure with a strong synergistic effect between the SMO MFs and the N-rich porous rGO sheets with open voids that facilitate the diffusion of NB. The electrochemical detection of NB at the SMO/N-rGO modified electrode was significantly enhanced. Using amperometry (i-t), the modified SMO/N-rGO sensor was shown to have two linear response ranges in the sensing of NB, with the lower linear concentration range from 7.1 nM to 1.0 mM and the higher linear concentration range varying from 1.1 mM to 2.5 mM. In addition, the limit of detection (LOD) was calculated to be 2.1 nM using the amperometric (i-t) technique. Common nitro derivatives, biomolecules, and cations often found in water systems had no influence on the detection of NB. At the same time, a good recovery of 96.1–99.6% was obtained for real-time monitoring analysis in tap and lake water samples. In this work, new electrochemical sensors for monitoring various pollutants are developed based on anchoring conductive metal oxide electrocatalysts on porous 3D carbon aerogels

Mesoporous carbon-based materials and their applications as non-precious metal electrocatalysts in the oxygen reduction reaction

Carbon is truly astonishing and the only element that can form so many different compounds and materials. In recent years, numerous nanostructured carbon-based materials have emerged and within this family, meso- porous and ordered mesoporous carbon have attracted considerable attention. In this paper, we review the recent developments in the applications of mesoporous carbon as an electrocatalyst for the oxygen reduction reaction (ORR). The ORR is one of the most studied electrochemical reactions with applications in the energy and environmental sectors. Following a short introduction to the methodologies employed in the fabrication of mesoporous and ordered mesoporous carbon, the performance of these materials in the ORR is reviewed. Initially, metal free heteroatom doped mesoporous carbon electrocatalysts are described, highlighting the roles of N, S and B as dopants. Next, mesoporous carbon materials with Fe, Co, Mn and Ni, as isolated single atom catalysts, are introduced. The role of mesoporous carbon as a support for nanostructured electrocatalysts is then discussed. Finally, the selectivity of the mesoporous carbon-based electrocatalysts for the four and two-electron ORR is discussed. While further developments and advancements are needed, it is clear that these mesoporous carbon-based materials have the potential to give highly efficient electrocatalysts for both the four and two electron ORR. Indeed, many of the reported electrocatalysts can outperform the commercial Pt/carbon electrocatalysts in alkaline solutions

Hybrid assembly with long and short reads improves discovery of gene family expansions

BACKGROUND: Long-read and short-read sequencing technologies offer competing advantages for eukaryotic genome sequencing projects. Combinations of both may be appropriate for surveys of within-species genomic variation. METHODS: We developed a hybrid assembly pipeline called "Alpaca" that can operate on 20X long-read coverage plus about 50X short-insert and 50X long-insert short-read coverage. To preclude collapse of tandem repeats, Alpaca relies on base-call-corrected long reads for contig formation. RESULTS: Compared to two other assembly protocols, Alpaca demonstrated the most reference agreement and repeat capture on the rice genome. On three accessions of the model legume Medicago truncatula, Alpaca generated the most agreement to a conspecific reference and predicted tandemly repeated genes absent from the other assemblies. CONCLUSION: Our results suggest Alpaca is a useful tool for investigating structural and copy number variation within de novo assemblies of sampled populations