Density Functional Theory Study of the Hydrogenation of Carbon Monoxide over the Co (001) Surface: Implications for the Fischer–Tropsch Process

The increasing demand for renewable fuels and sustainable products has encouraged growing interest in the development of active and selective catalysts for the conversion of carbon monoxide into desirable products. The Fischer–Tropsch process consists of the reaction of a synthesis gas mixture containing carbon monoxide and hydrogen (syngas), which are polymerized into liquid hydrocarbon chains, often using a cobalt catalyst. Here, first-principles calculations based on the density functional theory (DFT) are used to investigate the reaction mechanism of the Fischer–Tropsch synthesis over the Co (001) surface. The most energetically favorable adsorption configurations of the species involved in the carbon monoxide hydrogenation process are identified, and the possible elementary steps of hydrogenation and their related transition states are explored using the Vienna Ab initio simulation package (VASP). The results provide the mechanisms for the formation of CH4, CH3OH and C2H2 compounds, where the calculations suggest that CH4 is the dominant product. Findings from the reaction energies reveal that the preferred mechanism for the hydrogenation of carbon monoxide is through HCO and cis-HCOH, and the largest exothermic reaction energy in the CH4 formation pathway is released during the hydrogenation of cis-HCOH (−0.773 eV). An analysis of the kinetics of the hydrogenation reactions indicates that the CH production from cis-HCOH has the lowest energy barrier of just 0.066 eV, and the hydrogenation of CO to COH, with the largest energy barrier of 1.804 eV, is the least favored reaction kinetically

Aberrant expression of breast development-related microRNAs, miR-22, miR-132, and miR-212, in breast tumor tissues

Purpose: MicroRNAs (miRNAs) are a major class of small endogenous RNA molecules that posttranscriptionally regulate the expression of most genes in the human genome. miRNAs are often located in chromosomal fragile sites, which are susceptible to amplification or deletion. Chromosomal deletions are frequent events in breast cancer cells. Deletion and loss of heterozygosity at 17p13.3 have been reported in 49 of breast cancers. The aim of the current study was to evaluate potential expression alterations of miR-22, miR-132, and miR-212, which are located on the 17p13.3 locus and are required for mammary gland development. Methods: A matched case-control study was conducted, which included 36 pairs of tumor and matched nontumor surgical specimens from patients diagnosed with breast invasive ductal carcinoma. Formalin-fixed paraffin-embedded samples from archival collections at the pathology department of Shariati Hospital were prepared for RNA extraction using the xylene-ethanol method before total RNA was isolated with TRIzol Reagent. Specific primers were designed for cDNA synthesis and miRNA amplification. The expression of miRNAs was then evaluated by real-time polymerase chain reaction (RTPCR). Results: According to our RT-PCR data, the miR-212/ miR-132 family was downregulated in breast cancer (0.328-fold, p<0.001), and this reduced expression was the most prominent in high-grade tumors. In contrast, miR-22 exhibited a significant upregulation in breast tumor samples (2.183-fold, p=0.040). Conclusion: Consistent with the frequent deletion of the 17p13.3 locus in breast tumor cells, our gene expression data demonstrated a significant downregulation of miR-212 and miR-132 in breast cancer tissues. In contrast, we observed a significant upregulation of miR-22 in breast tumor samples. The latter conflicting result may have been due to the upregulation of miR-22 in stromal/cancer-associated fibroblasts, rather than in the tumor cells. © 2016 Korean Breast Cancer Society. All rights reserved

Effect of COVID-19 pandemic on medical waste management: a case study

Covid-19 Pandemic leads to medical services for the society all over the world. The Covid-19 pandemic influence the waste management and specially medical waste management. In this study, the effect of the Covid-19 outbreak on medical waste was evaluated via assessing the solid waste generation, composition, and management status in five hospitals in Iran. The results indicated that the epidemic Covid-19 leads to increased waste generation on average 102.2 in both private and public hospitals. In addition, the ratio of infectious waste in the studied hospitals increased by an average of 9 in medical waste composition and 121 compared with before COVID-19 pandemic. Changes in plans and management measurement such as increasing the frequency of waste collection per week leads to lower the risk of infection transmission from medical waste in the studied hospitals. The results obtained from the present research clearly show the changes in medical waste generation and waste composition within pandemic Covid-19. In addition, established new ward, Covid-19 ward with high-infected waste led to new challenges which should be managed properly by change in routine activities. © 2021, The Author(s)

C-Terminal Domain Deletion Enhances the Protective Activity of cpa/cpb Loaded Solid Lipid Nanoparticles against Leishmania major in BALB/c Mice

Cutaneous leishmaniasis (CL) is the most common form of leishmaniasis with an annual incidence of approximately 2 million cases and is endemic in 88 countries, including Iran. CL's continued spread, along with rather ineffectual treatments and drug-resistant variants emergence has increased the need for advanced preventive strategies. We studied Type II cysteine proteinase (CPA) and Type I (CPB) with its C-terminal extension (CTE) as cocktail DNA vaccine against murine and canine leishmaniasis. However, adjuvants' success in enhancing immune responses to selected antigens led us to refocus our vaccine development programs. Herein, we discuss cationic solid lipid nanoparticles' (cSLN) ability to improve vaccine-induced protective efficacy against CL and subsequent lesion size and parasite load reduction in BALB/c mice. For this work, we evaluated five different conventional as well as novel parasite detection techniques, i.e., footpad imaging, footpad flowcytometry and lymph node flowcytometry for disease progression assessments. Vaccination with cSLN-cpa/cpb-CTE formulation showed highest parasite inhibition at 3-month post vaccination. Immunized mice showed reduced IL-5 level and significant IFN-ã increase, compared to control groups. We think our study represents a potential future and a major step forward in vaccine development against leishmaniasis

New hybrid evolutionary algorithm for optimizing index-based groundwater vulnerability assessment method

Limited hydrogeological data accessibility leads scholars to improve the robustness of present qualitative groundwater vulnerability assessment methods using mathematical techniques. In the present study, we implemented three GIS-based groundwater vulnerability assessment indices, namely DRASTIC (Depth to water table, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and hydraulic Conductivity), SINTACS (Soggicenza, Infiltrazione, Non saturo, Tipologia della copertura, Acquifero, Conducibilità, and Superficie topografica), and GODS (Groundwater confinement, Overlying strata, Depth to groundwater, and Soil media) to assess the groundwater vulnerability levels. Although DRASTIC results showed better performance with respect to the nitrate concentration data from 50 observation wells in the study site, the index is still unreliable due to its inherent drawbacks, including subjectivity. Hybrid PSO-GA method is a successful optimization algorithm gathering the advantages of Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) while avoiding their shortcomings. The DRASTIC weighting system is optimized using PSO-GA optimization algorithm. Also, Step-wise Weight Assessment Ratio Analysis (SWARA) as a Multi-Attribute Decision Making (MADM) method is applied for changing ranges of DRASTIC rates and weights. The vulnerability indices obtained from SWARA-SWARA, DRASTIC-PSO-GA, and SWARA-PSO-GA frameworks are evaluated and compared with generic DRASTIC regarding the nitrate concentration dataset by employing Area Under the ROC Curve (AUC) and Grey relational analysis methods. Results show a noticeable improvement of correlation between indices and observed nitrate concentration after modifications and optimizations. The new hybrid SWARA-PSO-GA framework is the most effective framework in assessing the vulnerability of the present study area

A systematic review on membrane technology for carwash wastewater treatment: Efficiency and limitations

Car cleaning in carwash centers is one of the most important parts of water use. Carwash waste-waters (CW) contain significant quantities of contaminants such as oil and grease, surfactants, solids, nitrogen, and phosphorus. Various treatment technologies like membrane processes have been utilized for the treatment of CW; it should be noted that all these methods have advantages and disadvantages. Therefore, in this study, a systematic review of the benefits and limitations of the application of membrane technology for CW treatment was carried out. To this end, first, keywords were identified, and a search protocol was defined. Then, search in Scopus, PubMed, and Web of Science was explored to find related articles in June 2019. The results showed that ultrafilter is the most used membrane type for CW treatment; furthermore, the efficiency of membrane processes in the reduction of turbidity and chemical oxygen demand in most studies was reported to be more than 90 and 70, respectively. However, the rapid and severe flux reduction and pH changes in permeate are the significant limitations of membrane technology for CW treatment. The use of the pretreatment processes for fouling mitigation can be useful in CW treatment through the membrane processes. © 2021 Desalination Publications. All rights reserved

Cryopreservation of seeds of lily [Lilium Iedebourii (Baker) Bioss]: Use of sucrose and dehydration

Cryopreservation of germplasm at liquid nitrogen (-196°C) is a perfect method for the long-term conservation of plant genetic resources. A cryopreservation process using dehydration was performed for seeds of lily [ Lilium Iedebourii (Baker) Bioss]. Seeds were subjected to a rapid freezing protocol in liquid nitrogen following dehydration and treatment with 0.75 M sucrose for 1 h. Survival after freezing was nil for control seeds and 75% for seeds treated with sucrose and dehydration

Influence of nozzle configuration and particle size on characteristics and sliding wear behaviour of HVAF-sprayed WC-CoCr coatings

In this study, effect of feedstock particle size and nozzle configuration on deposition, microstructural features, hardness and sliding wear behaviour of high velocity air fuel (HVAF)-sprayed WC-CoCr coatings was evaluated. Three different WC-CoCr powders with nominal particle sizes of 5/20 μm (fine), 5/30 μm (medium) and 15/45 μm (coarse) were sprayed employing a HVAF gun with four distinct DeLaval nozzle configurations involving different lengths and/or exit diameters. Microstructure, phase constitution and mechanical characteristics of the coatings were evaluated using SEM, EDS, XRD and micro indentation testing. Specific wear rate for all the samples was determined under sliding conditions and a comprehensive post wear analysis was conducted. X-ray diffraction analysis showed negligible decarburization in all the HVAF-sprayed coatings. It was shown that decrease in particle size of employed feedstock results in discernible changes in microstructural features of the coatings as well as considerable improvement in their performance. Also, notable changes in wear mechanisms were identified on reducing particle size from coarse to medium or fine. Fine and coarse feedstock powders were found to be sensitive to the type of nozzle used while no major difference was observed in coatings from powders with medium cut size sprayed with different nozzles

Decreased expression of bioinformatically predicted piwil2-targetting microRNAs, miR-1267 and miR-2276 in breast cancer

Purpose: Human Piwil2, a member of Piwi subfamily of Argonaute proteins, is primarily expressed in testis, where it regulates self-renewal of germ cells. However, its ectopic expression has been reported with several tumors, including breast cancer. The upregulation of piwil2 in various stages of breast cancer suggested its suitability as a novel tumor biomarker. Considering the vital role of microRNAs (miR-NAs) in regulating the expression of most human genes, we hypothesized a concomitant downregulation of the bioinformatically-predicted piwil2-targetting microRNAs in breast cancer. Method: We employed different bioinformatic tools to predict piwil2-targeting miRNAs. Then, from the list of predicted miRNAs, we chose two less studied miRNAs (miR-1267 and miR-2276) for experimental validation. Using a real-time RT-PCR approach, we quantified the relative expression of the miRNAs in 31 pairs of formalin-fixed paraffin-embedded tumor/non-tumor tissue samples. Results: Our data revealed a noticeable but not statistically significant (P = 0.133) downregulation of miR-1267 in tumor samples, compared to non-tumor samples obtained from the same patients. Downregulation of miR-1267 was more significant in higher grades of malignancies (fold change = 2.39, P = 0.033) and also in lymph nodes containing high-grade tumor cells (fold change = 6.66, P = 0.02). Interestingly, a significant upregulation of miR-1267 was observed in tumors at high stages (stage 3a, 3b), compared to low stages (stage 2a, 2b) (fold change = 8.05, P = 0.048). Similar patterns of expression alteration were also observed for miR-2276. Conclusion: Altogether, our findings suggest a probable tumor suppressor role for miR-1267 and miR-2276 in breast tumor initiation and progression, but a probable promoting role for them in invasion and metastasis. � 2016, Academy of Medical Sciences of the I.R. Iran