Indirect Reaction Research Articles

Isolated Ni Atoms for Enhanced Photocatalytic H2O2 Performance with 1.05% Solar-to-Chemical Conversion Efficiency in Pure Water.

Photocatalytic hydrogen peroxide (H2O2) production encounters a major impediment in its low solar-to-chemical conversion (SCC) efficiency due to undesired H2O2 product decomposition. Herein, an isolated nickel (Ni) atom modification strategy is developed to adjust the thermodynamic process of H2O2 production to address the challenge. Sacrificial experiments and in situ characterization reveal that H2O2 generation occurs via a highly selective indirect two-electron oxygen reduction reaction. The optimized photocatalyst exhibits a remarkable H2O2 production rate of 338.9 μmol gcat-1 h-1 in pure water, representing a 48-fold enhancement. Notably, it attains an impressive SCC efficiency of 1.05%, surpassing that of current state-of-the-art catalysts. Theoretical insights reveal the downshifted d-band center facilitates moderate O2 adsorption and barrier-free *OOH conversion, favoring H2O2 release and preventing *H2O2 decomposition. This work showcases efficient H2O2 photosynthesis via d-band manipulation, presenting a fresh perspective for advancing high-efficiency SCC systems.

Indirect Immunofluorescence Test for Detecting HSV-1, 2 in Patients with Esophageal Cancer: A Pilot Cross-Sectional Survey in Kazakhstan.

To evaluate the detectability of herpes simplex virus type 1 and 2 (HSV-1, 2) antigens in the esophageal mucosa in esophageal cancer. A cross-sectional pilot study with a control group was conducted from December 2022 to May 2023. The patients were divided into two groups: the main group with verified esophageal cancer and the control group without esophageal cancer based on the histological report. Diagnosis using fibroesophagogastroscopy (FEGS), histological analysis, and indirect immunofluorescence reaction (iIFR) was accomplished according to indications at the outpatient center of the endoscopic department of the Multidisciplinary Medical Center, Astana. Descriptive statistics and nonparametric methods were used to analyze the data. A total of 30 patients were recruited in the study, with 15 patients in the main group and 15 patients in the control group. HSV-1 and HSV-2 antigens were detected in the 13 cases (86.7%) during the study of biomaterial from patients with confirmed esophageal cancer in the main group and only in one case (6.8%) in the control group (95% CI 7.35 - 1126.9%, p=0.001). The presence of lymphocytic infiltration was detected in 13 cases (86.7%) in the main group and in 5 cases (33.3%) in the control group (95% CI 2.07 - 81.48%, p = 0.008). The process of keratinization was identified in HSV-1,2 antigens positive cases in the main group in 5 cases (35.7%) G1, in 5 cases (35.7%) G2, and in 3 cases (21.4 %) G3 (95% CI 1.66 - 656.23%, p=0.002). Overall, the local activity of herpesvirus infection to a certain extent influences the malignant potential of tumor cells and the resistance of surrounding healthy tissues. A large-scale study is still needed to confirm these results. The present pilot study provided an overview of a possible method for detecting HSV-1,2 activity in malignant tissue from esophageal cancer.

The production and separation of 161Tb with high specific activity at the University of Utah

Targeted radiotherapy (TRT) is an increasingly prominent area of research in nuclear medicine, particularly in the context of treating cancerous tumors. One radionuclide of considerable interest for TRT is terbium-161 (t1/2 = 6.95 days), which undergoes beta emission and shares similar decay properties as 177Lu (FDA-approved as LUTATHERA® and PLUVICTO®). Besides beta emission, 161Tb also emits a significant number of conversion and Auger electrons further enhancing its therapeutic potential. Terbium-161 can be produced using nuclear reactors through an indirect neutron capture reaction, G64160dn,γG64161d→3.66min,β−T65161b, from 160Gd targets. However, a key challenge in utilizing 161Tb for TRT lies in effectively separating target and product materials to attain high specific activity for radiolabeling. Here, we detail the production of no-carrier added 161Tb using low flux research reactors (mean thermal (<0.625 eV) neutron flux: 1.356×1012n∙cm−2∙s−1) like the University of Utah TRIGA Reactor, using enriched 160Gd2O3 targets (1.5 ± 0.3 μCi of 161Tb per mg of 160Gd target per hour of irradiation). We also developed a separation technique based on cation exchange and extraction chromatography, suitable for mCi level irradiations with targets exceeding 200 mg. In a simulated full-scale irradiation, 161Tb was successfully isolated from large mass targets using cation exchange (AG 50W-X8, with 2-hydroxyisobutyric acid at 70 mM, pH 4.75) and extraction chromatography (LN Resin, 0.5–0.75 M HNO3) methods. This resulted in high apparent molar activities of [161Tb]Tb-DOTA (113 ± 3 MBq/nmol), demonstrating high purity 161Tb relevant for potential future preclinical applications.

Construction of sulfur-chloride co-doped triazine/heptazine homojunction carbon nitride photocatalyst for simultaneous production of H2O2 and lignin C-C bond cleavage

Photocatalytic H2O2 production and cleavage of lignin C-C bonds is a typical strategy that follows sustainable development. Unfortunately, the photocatalytic efficiency of these two reactions still faces significant challenges. Herein, a carbon nitride photocatalyst (tri/hep-CN) with sulfur-chloride co-doped triazine and heptazine structures was synthesized. It was simultaneously used for photocatalytic H2O2 production and lignin C-C bond cleavage. In the air atmosphere, the yield of H2O2 reached 1171.9 μmol•g−1•h−1 after the addition of β-1 lignin model 1,2-diphenylethanol (Dpol) to the solvent. The yield of H2O2 increased by 20 times compared with no addition of Dpol. The lignin C-C bond in Dpol is also efficiently broken, producing benzaldehyde and benzyl alcohol. tri/hep-CN has excellent photogenerated carrier separation efficiency and positive valence potential, which improves the photocatalytic H2O2 production and lignin C-C bond cleavage performance. Notably, coupling photocatalytic H2O2 production with lignin C-C bond cleavage to fully use photogenerated electrons and holes is also very important to obtain outstanding photocatalytic performance. Mechanistic studies have shown that photocatalytic H2O2 production follows an indirect reaction mechanism. Meanwhile, the cleavage of lignin C-C bond follows the Cβ radical mechanism and the single electron transfer mechanism. This work is very instructive for simultaneous photocatalytic H2O2 production and lignin C-C bond cleavage studies.

Photodegradation potential of selected non-steroidal anti-inflammatory drugs in a middle-order Alpine river downstream of a wastewater treatment plant, during a year of enduring water scarcity

The year 2022 was characterised by significant water shortages and droughts in Italy, with the most pronounced impact observed in the North-Western regions, including Piemonte. In conditions of water scarcity, treated wastewater undergoes little dilution by natural flows and this can deeply affect the chemistry of water-poor rivers and streams. However, increased pollution by wastewater would be partially offset by fast photodegradation of pollutants in shallow water and by the longer time allowed to photochemical reactions if water flows more slowly. We assessed the latter phenomena in the Stura di Lanzo, a middle-order Alpine river tributary of the largest Italian river, the Po, and affected by a wastewater treatment plant (WWTP). In 2022, the concentration values of the photochemically significant parameters nitrate, nitrite, and DOC were usually higher downstream of the WWTP outlet, which could slightly favour indirect photodegradation reactions. Direct and indirect photodegradation was assessed for the non-steroidal anti-inflammatory drugs paracetamol, diclofenac, and naproxen, all undergoing rather fast photoreactions. Photochemistry model results show that the three compounds would undergo 10–40 % photodegradation in spring and summer along the stretch separating the wastewater outlet from the confluence of Stura into the Po. Photodegradation would continue in the latter, but other WWTPs might contribute additional pollution in the meanwhile. Albeit significant, photodegradation could only partially promote the elimination of the contaminants.

Radiochemical separation of 161 Tb from neutron irradiated Gd target by liquid-liquid extraction technique

Abstract No-carrier-added (NCA) 161 Tb, which has advisable nuclear properties to be applied for cancer radiotherapy was produced at the Egyptian Second Research Reactor (ETRR-2) by neutron irradiation of natural gadolinium target via indirect nuclear reaction. The radiochemical separation of 161 Tb from irradiated gadolinium target was investigated based on solvent extraction technique using Cyanex 302. Several separation parameters were checked and optimized. According to the obtained results, the separation process of the investigated radioisotopes proceeds in two steps. The first step is an extraction of all of them into the organic phase in which the extraction % (98 %) was optimized at pH 4, 0.15 M of Cyanex 302 and 2.5 h extraction time. Moreover, the slope analysis method confirmed the participation of 2 mol of the organic extractant for the separation of 161 Tb from irradiated gadolinium. The second step is the separation of the 161 Tb isotope that was purified by the stripping of 159Gd with a citrate solution at pH 9, which is considered as a highly efficient and promising method for separation and purification of the two radioisotopes.

Synergistic effect of lightning rod and piezo-photocatalysis in sea urchin-shape Zn-MOF-74@g-C3N4 step-scheme heterojunction for H2O2 production under visible light irradiation

Piezo-photocatalytic H2O2 production was an emerging environmental technology that could convert solar energy into green chemicals, garnering significant attention. This study combined lightning rod effect and piezo-photocatalysis to achieve H2O2 production through an indirect two-electron oxygen reduction reaction pathway. A composite catalyst, sea urchin-shaped Zn-MOF-74@g-C3N4, had a surface of spherical Zn-MOF-74 made up of graphite phase carbon nitride nanoneedles with high curvature tips. These tips could induce a “lightning rod effect” property, accelerating charge transfer and separation by guiding electron migration along the sharp tip direction. The piezo-photocatalytic process, along with the construction of step-scheme heterojunction, generated a dual electric field, significantly enhancing the separation and migration rate of photogenerated carriers. As a result, the prepared Zn-MOF-74@g-C3N4 demonstrated a higher H2O2 production rate under the synergistic effect of lightning rod and piezo-photocatalysis. Free radical trapping experiments were conducted on various active species to uncover the mechanism behind the piezo-photocatalytic dual electric field coupling to produce H2O2.

Unveiling Ultrafast-Weak-Field Coherent Control of Indirect Dissociation Reactions.

Coherent control of molecular photodissociation through one-photon transitions has become a topic of interest in physical chemistry. Previous studies have shown that modulating the spectral phase of a single ultrafast laser pulse while keeping its spectral amplitude constant does not affect the dissociation yield of reactions originating from a pure eigenstate of the ground electronic state. Here, we explore the indirect photodissociation reaction of NaI molecules using theoretical and numerical methods. Our findings show that, in contrast to the outcomes achieved with negatively chirped pulses, time-dependent population of the eigenstates of the excited adiabatic potential induced by positively chirped laser pulses, acting as intermediates in the reaction, cannot be periodically restored to that caused by the unchirped pulse. This gives rise to an intriguing phenomenon: the sign of the pulse's chirp rate influences the distribution of dissociation fragments in coordinate and momentum space over extended periods. This work highlights the potential of using spectral-phase modulated pulses to manipulate indirect photodissociation reactions, offering a way to modify the transient photofragment distributions by controlling reaction intermediates.

Optimized electrochemical treatment of semi-coking wastewater for enhanced degradation of biological toxicity using a Ru-Ir-Ti anode and Co-Ti cathode

The Co-Ti cathode was prepared to reduce the biological toxicity of semi-coke wastewater by electrochemical system with commercial ruthenium-iridium titanium (Ru-Ir-Ti) anode. Meanwhile, the removal rate of chemical oxygen demand (COD), volatile phenol (VP) and ammonia nitrogen (NH3-N) in wastewater were also evaluated. Hence, the influence of processing time (A), dilution multiple (B), initial pH (C), electrolyte concentration (D) and current density (D) were systematic explored. After treatment, with the optimized experiment condition of processing time (150 min), dilution multiple (300 times), initial pH (3.2), electrolyte concentration (0.15 mol/L), current density (16 mV/cm2), the B/C value of wastewater was greatly improved from 0.12 to 0.31, the removal rate of COD, NH3-N and VP was 96.82 %, 92.34 % and 97.07 %, respectively. The sequence of significance was B>D>E*E>B*D>A*D>D*D. This most effective degradation was owing to the simultaneously oxidization of both cathode and anode, turning the highly biological toxic wastewater to the biodegradable one. The direct oxidation reaction happened on anode, furthermore, the indirect oxidation reaction would be accelerated near the cathode because of active free radicals generation such as ·OH and O2•– when the cobalt’s valence changed from +2 to +3. It deserve to be mentioned in this research is that the direct and indirect oxidation simultaneously contributed to the degradation of biological toxicity, which is great beneficial for the further bio-chemical processing.

One Health Approach to Toxoplasmosis: Owner and Dog Seropositivity as Spatial Indicators of Risk Areas for Acquired, Gestational and Congenital Transmission.

Toxoplasmosis has been of public health concern due to direct associations with socioeconomic vulnerability and inadequate living conditions. Accordingly, the present study aimed to assess antibodies against T. gondii, historical reported toxoplasmosis cases and associated socio-environmental risk factors in Pinhais, a full urban area of Curitiba, currently the eighth biggest metropolitan area of Brazil. Anti-Toxoplasma gondii antibodies were assessed by an indirect immunofluorescence reaction (RIFI). Owner and dog samples were also tested by IFAT to anti-Leishmania spp. and anti-Trypanosoma cruzi antibodies. Overall, 20/135 (14.8%) persons and 13/133 (9.8%) dogs from 25 different households were considered seropositive to T. gondii. All samples were seronegative to Leishmania spp. and Trypanosoma cruzi. Although no significant covariates were found in the regression model, statistically associated risk factors in the bivariate analysis included no public water use (p = 0.016) and drinking raw milk (p = 0.041) for owners, and obesity (p = 0.028) and tick infestation (p = 0.03) for dogs. In addition, a spatial cluster of T. gondii seropositivity for both owners and their dogs overlapped the location of historic reported cases of human acquired, gestational and congenital toxoplasmosis. Finally, the results herein showed tick infestation as an indicator of socio-environmental risk for T. gondii exposure in the household environment, and dogs may be used as sentinels for human toxoplasmosis cases.

Использование нейромаркетинговых исследований для оценки цифрового сервиса медицинских услуг

The development of innovative research methods expands the possibilities for studying various types of services, including digital ones. Assessment of the quality and level of development of digital services and their compliance with the expectations of patients in medicine is an important aspect for the image component of medical institutions. One of the tools for evaluating a digital service is neuromarketing. Purpose of the research is to identify the possibilities, prospects and ways of applying neuromarketing research to evaluate the digital service of medical institutions. The research is the analysis of theoretical sources of foreign and domestic authors. Cabinet and field studies were used. Desk studies were conducted in the form of analysis of secondary information sources, mainly on theoretical sources. Field studies were conducted in the form of an expert assessment. Comparative analysis has shown that neuromarketing research has a number of advantages compared to classical marketing methods, such as the ability to determine the indirect reaction of consumers and the emotional message when testing a digital service. Special attention is also paid to the potential of using neuromarketing research in the areas of digital medicine. At the same time, based on the analysis, it is determined which methods of neuromarketing research can be effectively used for each digital service and what results we can get. Within the framework of the study, the directions of evaluation of digital service by medical institutions using neuromarketing were identified, which will allow us to understand how to improve the platforms and what adjustments can be made. Based on the expert assessment on the possibilities of using neuromarketing research in the service sector, an IFAS analysis was conducted, which is a generalized analysis of the strengths and weaknesses of internal factors in the application of neuromarketing.

Gamma-ray spectroscopy of 55Sc

The N = 34 isotope 55Sc has been investigated using in-beam γ-ray spectroscopy at the RIKEN Radioactive Isotope Beam Factory. Spectra from the direct (p, pn) reaction as well as indirect reaction channels have been investigated. γ rays with energies 496(10), 570(12), 682(14), 1510(30), 1780(36), 2345(57) and 2470(50) keV have been observed. A level scheme was constructed based on γ γ coincidence analysis and relative intensities. The results have been compared to the level scheme already reported in literature, as well as to large-scale shell model calculations in the sd − pf model space. A new level at 1510keV, decaying directly to the ground state, has been proposed and spin-parity J π = 7/2− was tentatively assigned. The effect of including the ν g 9/2 orbital is discussed. It can be concluded that the main low-energy properties of 55Sc seem to be included in the original sd − pf model space.

Adaptive post-COVID-19 immune response in female subjects of the Russian arctic region.

The Arctic region's unfavorable living conditions adversely affect the spread of infectious diseases, including COVID-19, This, in turn, can also lead to increased morbidity and mortality rates in the area due to anumber of factors such as climate, environment, and high prevalence rate of pre-existing health issues like diabetes, obesity, and respiratory infections. These circumstances adversely affect maintaining the level of working capability. The aim of this paper is to investigate the ratio of immunocompetent cells involved in the adaptive post-COVID-19 immune response. The research includes an immunological assessment of 29women aged 20-40 years residing in Arkhangelsk, Russia, six months after recovering from COVID-19. The count of leukocytes in the peripheral blood and their differential were evaluated using standard methods to assess the immunological status. To delve deeper into the immunological landscape, phenotypes of lymphocytes (CD5+, CD8+, CD10+, and CD95+) were evaluated using an indirect immunoperoxidase reaction with monoclonal antibodies on dried drop lymphocyte preparations. After incubating blood with latex molecules, the activity and quantity of phagocytes were assessed using alight microscope. The neutrophil/lymphocyte ratio was found to be inverted in the female subjects under investigation. The high concentration of cytotoxic T-lymphocytes (CD8+) and lymphocytes with apoptotic receptors (CD95+) suggests apotential correlation with aconcurrent reduction in the expression of the total T-cell marker (CD5+) across all cases. This association was further linked to adecrease in lymphoproliferative activity and arelative decline in phagocytic activity. These findings led us to posit that the total recovery time after COVID-19 might extend beyond six months, indicative of aprolonged impact on the body's protective capacity. Our observations prompt the hypothesis that cellular immunity plays acrucial role in determining the severity of COVID-19 infection. Specifically, individuals with initially robust phagocytic activity may be predisposed to experiencing amilder form of the infection. However, this assumption warrants further investigation and clarification in individuals with moderate and severe disease progression (Tab. 1, Ref. 17). Keywords: arctic, COVID-19, cytotoxic t-lymphocytes, apoptosis, lymphoproliferation, cellular immunity, phagocytic activity.

Theoretical Study of the Thermal Rate Coefficients of the H3+ + C2H4 Reaction: Dynamics Study on a Full-Dimensional Potential Energy Surface.

Ion-molecular reactions play a significant role in molecular evolution within the interstellar medium. In this study, the entrance channel reaction, H3+ + C2H4 → H2 + C2H5+, was investigated using classical molecular dynamic (classical MD) and ring polymer molecular dynamic (RPMD) simulation techniques. We developed an analytical potential energy surface function with a permutationally invariant polynomial basis, specifically employing the monomial symmetrized approach. Our dynamic simulations reproduced the rate coefficient of 300 K for H3+ + C2H4 → H2 + C2H5+, aligning reasonably well with the values in the kinetic database commonly utilized in astrochemistry. The thermal rate coefficients obtained using both the classical MD and RPMD techniques exhibited an increase from 100 K to 300 K as the temperature rose. Additionally, we analyzed the excess energy distribution of the C2H5+ fragment with respect to temperature to investigate the indirect reaction pathway of C2H5+ → H2 + C2H3+. This result suggests that the indirect reaction pathway of C2H5+ → H2 + C2H3+ holds minor significance, although the distribution highly depends on the collisional temperature.

Constructing Photocatalytic Covalent Organic Frameworks with Aliphatic Linkers.

Photocatalytic covalent organic frameworks (COFs) are typically constructed with rigid aromatic linkers for crystallinity and extended π-conjugation. However, the essential hydrophobicity of the aromatic backbone can limit their performances in water-based photocatalytic reactions. Here, we for the first time report the synthesis of hydrophilic COFs with aliphatic linkers [tartaric acid dihydrazide (TAH) and butanedioic acid dihydrazide] that can function as efficient photocatalysts for H2O2 and H2 evolution. In these hydrophilic aliphatic linkers, the specific multiple hydrogen bonding networks not only enhance crystallization but also ensure an ideal compatibility of crystallinity, hydrophilicity, and light harvesting. The resulting aliphatic linker COFs adopt an unusual ABC stacking, giving rise to approximately 0.6 nm nanopores with an improved interaction with water guests. Remarkably, both aliphatic linker-based COFs show strong visible light absorption, along with a narrow optical band gap of ∼1.9 eV. The H2O2 evolution rate for TAH-COF reaches up to 6003 μmol h-1 g-1, in the absence of sacrificial agents, surpassing the performance of all previously reported COF-based photocatalysts. Theoretical calculations reveal that the TAH linker can enhance the indirect two-electron oxygen reduction reaction for H2O2 production by improving the O2 adsorption and stabilizing the *OOH intermediate. This study opens a new avenue for constructing semiconducting COFs using nonaromatic linkers.

Cellular immunity in women aged 20–40 living in different climatic and geographic regions

The aim. To identify phenotypic features of adaptive cellular immune responses in young women living in different climatic and geographic regions.Materials and methods. We examined 63 apparently healthy women, including 25 residents of Sovpolye settlement, Arkhangelsk region (Arctic region) and 38 residents of Tskhinvali (Republic of South Ossetia) aged 20–40. The content of lymphocytes, their phenotypes CD4+, CD8+, CD3+, CD5+, CD16+, CD10+, CD71+, CD25+, HLA-DR+ and CD95+, CEA (carcinoembryonic antigen) glycoprotein, and interleukin (IL) 6 and IL-10 cytokines was studied. Lymphocytes phenotyping was performed by indirect immunoperoxidase reaction using monoclonal antibodies (MedBioSpektr, Moscow) on “dried drop” lymphocyte sample with peroxidase conjugate and chromogen solution staining for immersion microscopy analysis (Nicon 50i, Japan). The content of CEA glycoprotein and cytokines was determined using ELISA.Results. In women living in Arctic region, a deficiency of CD5+, CD3+, CD10+, CD95+, CD71+, CD25+, HLA-DR+ cells, CEA and IL-6 concentrations is associated with high concentrations of CD8+ and IL-10. In women living in Southern region, a slight deficiency of CD5+, CD8+ and CD95+ cells is associated with high concentrations of CEA, IL-6, IL-10 and CD10+, CD16+ and HLA-DR+ cells.Conclusion. In inhabitants of different climatic regions, the features of formation of adaptive immune reactions are determined by different quantitative and qualitative composition of lymphocytes and cytokines phenotypes. Reduction of reserve capabilities of immune homeostasis is detected 3 times more often in inhabitants of the Arctic region.

Ozone Strong Water Dosing as Optimized Ozonation Process for Micropollutants Reduction in Wastewater Treatment Plants

ABSTRACT Growing concern over potential ecotoxicological problems caused by micropollutants (MPs) in water has led to the application of adsorptive and oxidative advanced treatment technologies at European wastewater treatment plants (WWTPs). Direct dosage of gaseous ozone via diffusers or pump-injection systems is the most common large-scale process applied in water and wastewater treatment. Studies point out that MP removal may take place via the direct, very selective reaction with the ozone molecule as well as the indirect reaction with the very reactive but nonselective hydroxyl radicals. Several process parameters and set-ups may affect the MPs elimination and inhibit or even cause the formation of transformation products (TPs) such as bromate. This work compares an alternative ozone application procedure (the so-called ‘ozone strong water’ dosing – OSW) with standard systems regarding MP elimination, ozone consumption, reaction time, and required plant space. A full-scale OSW system was installed and operated at the WWTP Duisburg-Vierlinden. A significant reduction in the time required to achieve the maximum possible elimination was observed for all six MPs investigated, with a hydraulic reaction time of 8 min. According to a theoretical calculation, the reactor volume could be reduced by two-thirds of the installed volume.

Imaging the Ion-Molecule Reaction Dynamics of O- + CD4.

While neutral reactions involved in methane oxidation have been intensively studied, much less information is known about the reaction dynamics of the oxygen radical anion with methane. Here, we study the scattering dynamics of this anion-molecule reaction using crossed-beam velocity map imaging with deuterated methane. Differential scattering cross sections for the deuterium abstraction channel have been determined at relative collision energies between 0.2 and 1.5 eV and ab initio calculations of the important stationary points along the reaction pathway have been performed. At lower collision energies, direct backscattering and indirect complex-mediated reaction dynamics are observed, whereas at higher energies, sideways deuterium stripping dominates the reaction. Above 0.7 eV collision energy, a suppressed cross section is observed at low product ion velocities, which is likely caused by the endoergic pathway of combined deuteron/deuterium transfer, forming heavy water. The measured product internal energy is attributed mainly to the low-lying deformation and out-of-plane bending vibrations of the methyl radical product. The results are compared with a previous crossed-beam result for the reaction of oxygen anions with nondeuterated ̧methane and with the related neutral-neutral reactions, showing similar dynamics and qualitative agreement.

Molecular characterization of Marek's Disease virus reveals reticuloendotheliosis virus-long terminal repeat integration in the genome of the field isolates in Egypt

The highly contagious, immunosuppressive, and cancer-causing Marek's disease virus (MDV) infects chickens. The financial costs of Marek's disease (MD) are significant for the chicken industry. In this study, a total of 180 samples from chicken farms suspected to be MDV-infected were collected. The chickens were sampled during the period between the months of October 2016 and February 2018 at Dakahlia and Damietta Governorates, Egypt. A total of 36 pooled samples were created. The prepared samples were inoculated into embryonated chicken eggs (ECEs). Indirect fluorescent antibody technique (IFAT) and ICP4 gene-based polymerase chain reaction (PCR) were used for MDV identification. For the genetic characterization of the identified virus, The ICP4 gene sequence was identified and compared with the sequences available from various regions of the world. Furthermore, the genomes of all detected MDVs were screened for the long terminal repeat (LTR) region of reticuloendotheliosis (REV) in their genomes. The results showed that 31 out of 36 pooled samples (86.1%) inoculated into ECEs displayed the characteristic pock lesions. By using IFAT and PCR to identify MDV in ECEs, positive results were found in 27 samples (75%). The Egyptian virus is thought to be genetically closely related to MDVs circulating in Ethiopia, China, and India. REV-LTR was amplified from 6 out of 27 field isolates genomes (22.2 %) while MDV vaccine strains were free from REV-LTR insertion. The integrated REV-LTRs depicted a close genetic relationship with those integrated in fowl poxvirus (FWPV) circulating in Egypt as well as those integrated in FWPVs and MDVs from China, USA, South Africa, and Australia. To the best of our knowledge, this investigation represents the first identification and characterization of REV-LTR insertions in Egyptian MDV field isolates. Given the findings above, additional research in the future seems crucial to determine how the REV-LTR insertions affect MDV pathogenesis, virulence, and insufficient vaccination protection.

Passive and active oxidation of Al in the Al–Al2O3 composite refractory at high temperatures in air

The active and passive oxidation of Al in Al–Al2O3 composites was investigated in air at high temperatures. As fresh air impinged on the surface of the Al–Al2O3 composite sample, a thin Al2O3 layer was preferentially formed via passive oxidation of Al, which consumed most of the oxygen and lowered the local Po2 inside the sample. At low Po2, active oxidation of Al occurred and predominated in the interior transition layer, which further lowered the local Po2 to extremely low values within the non-oxide stability field. The local equilibrium PAlxOy generated by the active oxidation of Al reached a micro-positive pressure state and served as a gas barrier, hindering the inward diffusion of O2. The Po2 inside the composite was lowered by Al in the outer layers via a self-gettering process. Subsequently, Al4O4C and Al2OC-AlN solid solution were formed by both the direct reaction of Al(l) and the indirect reaction of AlxOy(g). After sintering in air, the Al–Al2O3 composite exhibited a functional gradient structure with a thin oxide layer and an interior non-oxide-reinforced corundum. A reaction mechanism model was established.