Characterization Studies of a GC based SAW Sensor System for Potential Detection and Identification of Toxic Environmental Gases/Vapors

The characterization of a custom-designed GC-based SAW e-Nose sensor system is presented here to study the sensing ability of the sensor system to detect and identify low medium and high toxic vapors. A semi-automated multi-vapor generator generates vapors of chemical compounds that are then exposed to the sensing system to examine its performance under various concentrations. Time-domain verses frequency response of GC-SAW Sensor is noted for repeated cycles against different chemical compounds like xylene, 1,2 dibromoethane, dimethyl sulfate, triethyl phosphate, nitrobenzene, phosphorous trichloride being tested. The generated data is examined using a principle component analysis (PCA) technique to detect a unique response for an individual chemical compound. Experimental results are reported.

Influence of the chemical mutagens on the seed germination, the growth and manifestation of decorative characteristics in the seed offspring of the representatives of the genus Pinus L.

The influence of various concentrations of chemical mutagens on the seed germination, the growth and manifestation of decorative traits in the seed offspring of mountain pine (Pinus mugo Turra), Scots pine (Pinus sylvesrtis L.), and Scots pine “witch’s broom” (“WB”) is assessed. A 0.1 % aqueous solution of colchicine, as well as 0.1, 0.5, and 1.0 % aqueous solutions of dimethyl sulfate (DMS) was used as mutagens. The species-specificity of the influence of chemical mutagens on the seed germination was established. Thus, the treatment of mountain pine seeds with aqueous solutions of colchicine and DMS had some stimulating influence on their germination. On the contrary, the germination of the Scots pine seeds and the seeds collected from the Scots pine “WB” decreased with increasing the DMS concentration in the solution. Among the offspring obtained using chemical mutagens, specimens were identified with changes in the growth strength towards dwarfism, the branching features of which manifested themselves in the form of apical dominance violation and shoot formation growth, with changes in the color of needles, including winter color changes of different-intensity color from green to yellow, bronze or bronze yellow. As a result of the research, 363 specimens with atypical traits were selected for further breeding work.

METHYLATION OF 4-NIТRO-1,2,3-TRIAZOLE IN NEUTRAL ENVIRONMENTS

Алкилирование NH-гетероцикла4-нитро-1,2,3-триазола диметилсульфатом сопровождается тандемными реакциями алкилирования–кватернизации и приводит к образованию сложной смеси продуктов N-моноалкилирования по всем трем гетероатомам N-1, N-2 и N-3 с существенным преобладанием неизвестного ранее N3-производного, а также продукта их дальнейшего превращения – соли 1,3-диметил-4-нитро-1,2,3-триазолия. Alkylation of the NH-heterocycle of 4-nitro-1,2,3-triazole with dimethyl sulfate is accompanied by tandem alkylation-quaternization reactions and leads to the formation of a complex mixture of N-monoalkylation products at all three heteroatoms N-1, N-2, and N-3 with a significant predominance previously unknown N3-derivative, as well as the product of their further conversion - 1,3-dimethyl-4-nitro-1,2,3-triazolium salts.

Immobilization of Pectinolytic Enzymes on Nylon 6/6 Carriers

Pectinolytic enzymes are an important tool for sustainable food production, with a wide range of applications in food processing technologies as well as the extraction of bioactive compounds from pectin-rich raw materials. In the present study, we immobilized commercial pectinase preparation onto pellet and thread shaped nylon 6/6 carriers and assessed its stability and reusability. Five commercial pectinase preparations were tested for different pectin de-polymerizing activities (pectinase, polygalacturonase, and pectin lyase activities). Thereafter, Pectinex® Ultra Tropical preparation, exhibiting the highest catalytic activities among the studied preparations (p < 0.0001), was immobilized on nylon 6/6 using dimethyl sulfate and glutaraldehyde. The immobilization yield was in accordance with the carrier surface area available for enzyme attachment, and it was 1.25 ± 0.10 U/g on threads, which was over 40 times higher than that on pellets. However, the inactivation of immobilized enzymes was not dependent on the shape of the carrier, indicating that the attachment of the enzymes on the surface of nylon 6/6 carriers was similar. The half-life of enzyme inactivation fast phase at 4 °C was 12.8 days. After 5 weeks, the unused threads retained 63% of their initial activity. Reusability study showed that after 20 successive cycles the remaining activity of the immobilized pectinase was 22%, indicating the good prospects of reusability of the immobilized enzyme preparations for industrial application.

Equilibrium studies on the uptake of nitrate and phosphate ion onto low-cost adsorbent prepared via radiation-induced graft polymerization and hydrazine hydrate functionalization

In the study, cellulosic fabric waste-based anion exchanger (‘Cell-AE’), with abundant N+(CH3)2 functional groups were prepared by graft copolymerization of acrylonitrile (AN) onto cotton fabric waste using γ radiation 60Co, followed by chemical modification with hydrazine hydrate and alkylation with dimethyl sulfate. Factors affecting the grafting process, such as radiation dose and monomer concentration, was investigated. The main adsorbent (‘Cell-AE’) and its intermediate precursors were characterized using Fourier transform infrared spectroscopy (FTIR) and scan electron microscopy (SEM). The nitrate and phosphate sorption potentials of the Cell-AE further evaluated via batch mode. Based on the results obtained, ‘Cell-AE’ showed higher adsorption affinity towards phosphate ion (19.56 mg/g), when compared to that of the nitrate ion (11.23 mg/g). Similarly, the phosphate and nitrate ion adsorption onto ‘Cell-AE’ obeys both Dubinin–Radushkevich (D-R) and Redlich-Peterson (R-P) isotherm models, respectively. The present study conclusively proffered a potential mitigation approach to cotton fabric waste management.

Optimasi Sintesis Methyl Cellulose (MC) dari Biji Salak (Salacca edulis Reinw) Pondoh Super

Snake fruit (Salacca zalacca) is one of the typical fruits from Indonesia. Pondoh is one of the snake fruit species largely found in Yogyakarta. The kernels of snake fruit are wastes, but contains a lot of cellulose. Cellulose can be processed into methyl cellulose And be used as food additive. This study aimed to understand the optimized the optimizing synthesis of methyl cellulose through the concentration of NaOH, dimethyl sulfate and reaction temperature. The study was conducted by extracting cellulose using 4 % NaOH concentrations. Dehemicellulose and bleaching were done to dilute hemicellulose and lignin. The optimization of methyl cellulose was done using Response Surface Methodology with various concentrations of NaOH (10, 15, 20, 25, 30%), dimethyl sulfate (2, 3, 4, 5, 6 ml), and temperature (45, 50, 55, 60, 65°C). NaOH could change cellulose crystalline region and formed Na-cellulose. Dimethyl sulfate can be acted as substitution agent, while temperature controlling plays role to obtain appropriate conditions for reaction. The results showed that the use of NaOH concentration, dimethyl sulfate and temperature affected the degree of substitution, OHC and lightness. The addition of NaOH and dimethyl sulfate in producing methyl cellulose had more effect on the increasing of degree of substitution than temperature treatment. The optimum condition of methyl cellulose were 0.91% NaOH; 3.52 ml of dimethyl sulfate, at 46.51°C temperature.

Insights into the secondary structural ensembles of the full SARS-CoV-2 RNA genome in infected cells

SARS-CoV-2 is a betacoronavirus with a single-stranded, positive-sense, 30-kilobase RNA genome responsible for the ongoing COVID-19 pandemic. Currently, there are no antiviral drugs with proven efficacy, and development of these treatments are hampered by our limited understanding of the molecular and structural biology of the virus. Like many other RNA viruses, RNA structures in coronaviruses regulate gene expression and are crucial for viral replication. Although genome and transcriptome data were recently reported, there is to date little experimental data on native RNA structures in SARS-CoV-2 and most putative regulatory sequences are functionally uncharacterized. Here we report secondary structure ensembles of the entire SARS-CoV-2 genome in infected cells at single nucleotide resolution using dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) and the algorithm ‘detection of RNA folding ensembles using expectation–maximization’ clustering (DREEM). Our results reveal previously undescribed alternative RNA conformations across the genome, including structures of the frameshift stimulating element (FSE), a major drug target, that are drastically different from prevailing in vitro population average models. Importantly, we find that this structural ensemble promotes frameshifting rates (~40%) similar to in vivo ribosome profiling studies and much higher than the canonical minimal FSE (~20%). Overall, our result highlight the value of studying RNA folding in its native, dynamic and cellular context. The genomic structures detailed here lays the groundwork for coronavirus RNA biology and will guide the design of SARS-CoV-2 RNA-based therapeutics.

Secondary Structural Model of MALAT1 Becomes Unstructured in Chronic Myeloid Leukemia and Undergoes Structural Rearrangement in Cervical Cancer

Long noncoding RNAs (lncRNAs) influence cellular function through binding events that often depend on the lncRNA secondary structure. One such lncRNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is upregulated in many cancer types and has a myriad of protein- and miRNA-binding sites. Recently, a secondary structural model of MALAT1 in noncancerous cells was proposed to form 194 hairpins and 13 pseudoknots. That study postulated that, in cancer cells, the MALAT1 structure likely varies, thereby influencing cancer progression. This work analyzes how that structural model is expected to change in K562 cells, which originated from a patient with chronic myeloid leukemia (CML), and in HeLa cells, which originated from a patient with cervical cancer. Dimethyl sulfate-sequencing (DMS-Seq) data from K562 cells and psoralen analysis of RNA interactions and structure (PARIS) data from HeLa cells were compared to the working structural model of MALAT1 in noncancerous cells to identify sites that likely undergo structural alterations. MALAT1 in K562 cells is predicted to become more unstructured, with almost 60% of examined hairpins in noncancerous cells losing at least half of their base pairings. Conversely, MALAT1 in HeLa cells is predicted to largely maintain its structure, undergoing 18 novel structural rearrangements. Moreover, 50 validated miRNA-binding sites are affected by putative secondary structural changes in both cancer types, such as miR-217 in K562 cells and miR-20a in HeLa cells. Structural changes unique to K562 cells and HeLa cells provide new mechanistic leads into how the structure of MALAT1 may mediate cancer in a cell-type specific manner.

Study of methylation reactions of 2-phenylquinazoline-4-tion with “soft” and “hard” methylation agents and determination of its biological activity

Alkylation reactions of 2-phenylquinazoline-4-thion with methylation agents “soft” (methyl iodide) and “hard” (dimethyl sulfate, methyltozylate) were studied. It was found that the reaction proceeds with the formation of alkyl products at the N3 - and S4 - reaction centers, depending on the methylation agent, solvent and temperature. This indicated the ambivalent nature of the 2-phenylquinazoline-4-tion anion. Prolongation of the reaction time leaded to the formation of a second isomeric product (VII). A slight increase in phenyl N3-product (VII) yield was noted when dimethyl sulfate and methylfolate were used as methylation agents. In non-polar proton-free solvent DMF and dipolar proton-free solvent acetonitrile, only N-methyl product (VII) was formed because of the reaction. An increase in the polarity of the solvent and the “hardness” of the methylation agent leads to an increase in the yield of N3 products.