Untersuchungen ueber den Einfluss des Proteingehaltes im Futter auf das Wachstum der langen Roehrenknochen von Broilern verschiedener Herkuenfte (Morphologische Untersuchungen und Mineralstoffbestimmung)

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Molecular epidemiology and phylogenetic analysis of Tams I gene of <i>Theileria annulata</i> in Khyber Pakhtunkhwa, Pakistan

Theileriosis is a hemoparasitic disease that affects a wide range of different animal species and is caused by various species of Theileria. This study aimed to determine the molecular epidemiology of Theileria annulata through microscopy and PCR, in crossbred cattle in some districts of Khyber Pakhtunkhwa, Pakistan. For this study, a total of 384 blood samples were collected from cattle in the Peshawar (n=120), Charsadda (n=94), Nowshera (n=84), and Swabi (n=86) districts. Microscopy and PCR were used to determine the overall prevalence of theileriosis, which was found to be 15.8 and 22.6%, respectively. Theileria annulata was detected in blood samples through PCR in the study area, and the target gene i.e., Tams 1, of positive samples was sequenced. The sequences in the current study revealed high sequence homology (ranging from 96 to 100%) with Tams 1 sequences of neighboring countries present in the NCBI database. Season, breed, age, and sex were found to be important risk factors among the several risk factors examined, whereas, among different clinical manifestations, lymphadenopathy showed a strong association with theileriosis. According to Cohen’s kappa and ROC analysis, microscopy was proven to be a fair diagnostic test for detecting theileriosis in cattle, and may be used in combination with molecular techniques for screening a large number of animals

Novel Mn-/Co-N x Moieties Captured in N-Doped Carbon Nanotubes for Enhanced Oxygen Reduction Activity and Stability in Acidic and Alkaline Media

Fe-N-C-based electrocatalysts have been developed as an encouraging substitute compared to their expensive Pt-containing equivalents for the oxygen reduction reaction (ORR). However, they still face major durability challenges from the in- situ production of Fenton radicals. Therefore, the synthesis of Fe-free ORR catalysts is among the emerging concerns. Herein, we have precisely applied a multistep heating strategy to produce mesoporous N-doped carbon nanostructures with Mn-/Co-Nx dual moieties from mixed-metal zeolitic imidazolate frameworks (ZIFs). It is found that their unique structure, with dual-metallic active sites, not only offers a high electrochemical performance for the ORR (E1/2 = 0.83 V vs reversible hydrogen electrode (RHE) in acid media), but also enhances the operational durability of the catalyst after 20 000 cycles with 97% of retention and very low H2O2 production (<5%) in 0.1 M HClO4. In addition, the catalyst performs well toward the ORR also in alkaline solution (exhibiting E1/2 = 0.90 V and 30 000 cyclic stability). © 2021 American Chemical Society

Synthesis and nano-engineering of MXenes for energy conversion and storage applications: Recent advances and perspectives

MXenes, with general formula Mn+1XnTx, (where n = 1–4; M = early transition metals; X = C, N, or a combination of both; Tx = surface functional groups like –OH, -O, -F, or -Cl) are a diverse group of two-dimensional (2D) layered transition metal carbides, nitrides and carbonitrides. Due to the energy and environmental problems, the renewable energy resources have critical importance. Owing to their exceptional properties, including very high electrical conductivity and thermal stability, MXenes are finding increasing applications in energy conversion and storage devices to solve the energy problems of modern society. In this review, we aim to provide a timely snapshot of recent advances in the synthesis, design, and engineering of MXene-based materials for the energy sector. Strategies for optimizing the performance of MXenes materials in energy applications, such as surface nano-engineering and compositing with 0D, 1D, 2D, and/or 3D materials are explored in the context of key energy conversion and storage devices. To fulfil the basic requirement of renewable energy devices, electrocatalysis of small molecular reactions such as ORR, OER, HER, NRR, and CO2RR, are comprehensively discussed on MXene-based electrode materials. Further, the MXene-based electrode materials for energy storage devices such as metal-ion batteries (Na+, Li+, K+, etc.), Li-S batteries and supercapacitors, are also summarized. Finally, challenges and future opportunities for MXenes in these different energy applications are discussed. This article may provide a leading route for design and synthesis of new catalytic materials toward efficient performance of energy conversion and storage devices. © 2021 Elsevier B.V

Nanoscale ZrRGOCuFe layered double hydroxide composites for enhanced photocatalytic degradation of dye contaminant

YesCoprecipitation method was used to prepare non-stoichiometric pristine copper and iron layered double hydroxide (LDH) doped with zirconium and embedded with reduced graphene oxide. The composite materials (ZrRGOCuFe LDHs) were studied for the photodegradation of methylene blue (MB) dye as a model contaminant from an aqueous solution. These composites were fully characterized by X-rays diffraction (XRD), Scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Photoluminescence (PL), Raman spectroscopy and Electrochemical Impedance Spectroscopy (EIS). The results of Raman, Photoluminescence and Electrochemical Impedance Spectroscopy revealed the presence of oxygen defects level in the composites. Such defects are believed to be essential for boosting the catalytic potential of the composites. The secondary pollution manifested by transition metal ions is usually tackled by inducing heterogeneous catalysis. Herein, pristine CuFe LDH has been doped with Zr and RGO moieties to realize heterogeneous catalysis within ZrRGOCuFe LDH dopants. An admirable band ranging between 1.74 and 2.0 eV was obtained for the doped materials. The remarkable photodegradation efficiency of 95.2% was achieved by using heterogeneous photocatlyst Zr0.6RGOCuFe LDH within 75 min at a pH of 7, photocatalyst dosage of 1.0 g/L and methylene blue dye solution of 10 ppm under visible light irradiation. The total organic content (TOC) analysis has revealed removal of 92% organic content. Moreover, the catalyst has the potentia to maitain sufficient stability and reusability capacity even after three successive cycles. The reaction kinetics and proposed photocatalytic mechanism were also explained in detail

Single-atom catalysis for zinc-air/O2 batteries, water electrolyzers and fuel cells applications

We summarize the latest progress achieved in precious and non-precious carbon based single-atom catalytic active sites, including Pd, Pt, Ir, Ru, Rh, Au, Fe, Co, Mn, Zn, Sn, and Cu, aiming at facilitating metal-air/O2 batteries, water electrolyzers, and fuel-cells commercialization. Correspondingly, several aspects of the intrinsic catalytic activity, for example, the role of center-metal-atoms, number and type of metal-coordinated atoms, and the surrounding environment of central-metal-atom, are systematically discussed. This review includes two major parts: i) the rational summary of recently reported catalysts, comprising synthesis/identification approaches of active-sites to catalytic performance, and ii) the basic key factors, influencing the performance. Equal emphasis is given to experimental results and theoretical calculations to figure out the structure-function correlation between the active-sites configuration and the intrinsic electrocatalytic performance. A research paradigm is suggested to design advanced single-metal-atom catalysts for fuel cells and metal-air batteries. Regardless of these developments, we highlight some remaining debatable issues that require urgent attention. Finally, we provide a comprehensive perspective on the development and progress of single-metal-atom catalysts for fuel cells and batteries. © 2021 Elsevier B.V

Nanostructure engineering of metal–organic derived frameworks: Cobalt phosphide embedded in carbon nanotubes as an efficient orr catalyst

Heteroatom doping is considered an efficient strategy when tuning the electronic and structural modulation of catalysts to achieve improved performance towards renewable energy applications. Herein, we synthesized a series of carbon-based hierarchical nanostructures through the controlled pyrolysis of Co-MOF (metal organic framework) precursors followed by in situ phosphidation. Two kinds of catalysts were prepared: metal nanoparticles embedded in carbon nanotubes, and metal nanoparticles dispersed on the carbon surface. The results proved that the metal nanoparticles embedded in carbon nanotubes exhibit enhanced ORR electrocatalytic performance, owed to the enriched catalytic sites and the mass transfer facilitating channels provided by the hierarchical porous structure of the carbon nanotubes. Furthermore, the phosphidation of the metal nanoparticles embedded in carbon nanotubes (P-Co-CNTs) increases the surface area and porosity, resulting in faster electron transfer, greater conductivity, and lower charge transfer resistance towards ORR pathways. The P-Co-CNT catalyst shows a half-wave potential of 0.887 V, a Tafel slope of 67 mV dec−1, and robust stability, which are comparatively better than the precious metal catalyst (Pt/C). Conclusively, this study delivers a novel path for designing multiple crystal phases with improved catalytic performance for energy devices. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Recent advances on oxygen reduction electrocatalysis: Correlating the characteristic properties of metal organic frameworks and the derived nanomaterials

This review summarizes the current advances of hetero-doped (Fe, Co, P, S, N) nanostructures derived from MOFs (metal-organic frameworks) for the oxygen reduction reaction (ORR) electrocatalysis. These nanomaterials are classified as: 0D (polyhedrons, hollow and core-shell structures), 1D (nanotubes and nanorods), 2D (nanosheets), and 3D (honeycomb like frameworks) morphologies. It is thoroughly discussed the critical and very important pathway of ORR, which occurs in electrochemical devices such as fuel cells and metal-air batteries (high energy capacity, excellent conversion efficiency and low environmental impact). Emphasis is given on the mechanistic studies devoted to both the nanostructure formation from MOFs and the morphology-activity relationship of transition-metal anchored carbon nanostructures transformed from MOFs. Controlled electronic structures, extrinsic/intrinsic structures and interface (edge) properties are also discussed for the ORR performance, providing a useful preparation approach for carbon doped with heteroatoms by rationally designing MOF precursors. As a result of the ongoing flexibility of these frameworks, the doped carbon based electrocatalysts present enhanced ORR performance, which expands their applications (except for fuel cells) in other energy conversion and storage devices like supercapacitors and metal ion batteries. © 2019 Elsevier B.V

Identification of Catalytic Active Sites for Durable Proton Exchange Membrane Fuel Cell: Catalytic Degradation and Poisoning Perspectives

Recent progress in synthetic strategies, analysis techniques, and computational modeling assist researchers to develop more active catalysts including metallic clusters to single-atom active sites (SACs). Metal coordinated N-doped carbons (M-N-C) are the most auspicious, with a large number of atomic sites, markedly performing for a series of electrochemical reactions. This perspective sums up the latest innovative and computational comprehension, while giving credit to earlier/pioneering work in carbonaceous assembly materials towards robust electrocatalytic activity for proton exchange membrane fuel cells via inclusive performance assessment of the oxygen reduction reaction (ORR). M-Nx-Cy are exclusively defined active sites for ORR, so there is a unique possibility to intellectually design the relatively new catalysts with much improved activity, selectivity, and durability. Moreover, some SACs structures provide better performance in fuel cells testing with long-term durability. The efforts to understand the connection in SACs based M-Nx-Cy moieties and how these relate to catalytic ORR performance are also conveyed. Owing to comprehensive practical application in the field, this study has covered very encouraging aspects to the current durability status of M-N-C based catalysts for fuel cells followed by degradation mechanisms such as macro-, microdegradation, catalytic poisoning, and future challenges. © 2022 The Authors. Small published by Wiley-VCH GmbH

Characterization of the Gastrointestinal and Reproductive Tract Microbiota in Fertile and Infertile Pakistani Couples

The human microbiota is recognized as a vital “virtual” organ of the human body that influences human health, metabolism, and physiology. While the microbiomes of the gut, oral cavity, and skin have been extensively studied in the literature, relatively little work has been done on characterizing the microbiota of the human reproductive tract organs, and specifically on investigating its association to fertility. Here, we implemented a 16S ribosomal RNA (rRNA) amplicon sequencing approach to sequence and characterize the gut and genital tract microbiomes from several married Pakistani couples. The recruited individuals included 31 fertile and 35 infertile individuals, with ages ranging from 19–45 years. We identified several fluctuations in the diversity and composition of the gut and genital microbiota among fertile and infertile samples. For example, measures of α-diversity varied significantly between the genital samples donated by fertile and infertile men and there was overall greater between-sample variability in genital samples regardless of gender. In terms of taxonomic composition, Actinobacteria, Bacteroidetes, and Firmicutes fluctuated significantly between the gut microbiomes of fertile and infertile samples. Finally, biomarker analyses identified features (genera and molecular functions and pathways) that differed significantly between the fertile and infertile samples and in the past have been associated with bacterial vaginosis. However, we emphasize that 16S amplicon data alone has no bearing on individual health and is merely representative of microbial taxonomic differences that could also arise due to multiple other factors. Our findings, however, represent the first effort to characterize the microbiome associated with fertile and infertile couples in Pakistan and will hopefully pave the way for more comprehensive and broad-scale investigations in the future. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]