Search

The cell wall integrity (CWI) signaling pathway regulates yeast cell wall biosynthesis, cell division, and responses to external stress. The cell wall, comprised of a dense network of chitin, β-1,3- and β-1,6- glucans, and mannoproteins, is very thin,

Introduction The U.S. Military members experiencing combat-related injuries have a higher chance of developing infections by multidrug-resistant (MDR) bacteria at admission to military hospitals. MDR wound infections result in higher amputation rates and greater risks for subsequent or chronic infections that require readmission or extended stay in the hospital. Currently, there is no FDA-clear, deployable early diagnostic system for suitable field use. We are reporting our efforts to improve a previously developed Rapid Label-free Pathogen Identification (RAPID) system to detect viable MDR bacteria in wound infections and perform antibiotic susceptibility testing (AST). Specifically, we added multiplex and automation capability and significantly simplified the sample preparation process. A functional prototype of the improved system was built, and its performance was validated using a variety of lab-prepared spiked samples and real-world samples. Materials and Methods To access the baseline performance of the improved RAPID system in detecting bacteria presence, we selected 17 isolates, most of them from blood or wound infections, and prepared mono-strain spiked samples at 104 to 106 cfu/mL concentration. These samples were processed and analyzed by the RAPID system. To demonstrate the AST capability of the system, we selected 6 strains against 6 different antibiotics and compared the results from the system with the ones from the gold standard method. To validate the system's performance with real-world samples, we first investigated its performance on 3 swab samples from epicutaneous methicillin-resistant Staphylococcus aureus –exposed mouse model. The AST results from our system were compared with the ones from the gold standard method. All animal experiments were approved by the Johns Hopkins University Animal Care and Use Committee (Protocol No. MO21M378). Then, we obtained swab samples from 7 atopic dermatitis (AD) patients and compared our AST results with the ones from the gold standard method. The human subject protocol was approved by the Johns Hopkins Medicines Institutional Review Boards (Study No. CR00043438/IRB00307926) and by USAMRDC (Proposal Log Number/Study Number 20000251). Results High-quality data were obtained from the spiked samples of all 17 strains. A quantitative analysis model built using these data achieved 94% accuracy in predicting the species ID in 8 unknown samples. The AST results on the spiked samples had shown 100% matching with the gold standard method. Our system successfully detects the presence/absence of viable bacteria in all 3 mouse and 7 AD patient swab samples. Our system shows 100% and 85.7% (6 out of 7) accuracy when compared to the oxacillin susceptibility testing results for the mouse and the AD patient swabs, respectively. Conclusions Our system has achieved excellent performance in detecting viable bacteria presence and in performing AST in a multiplex, automated, and easy-to-operate manner, on both lab-prepared and real samples. Our results have shown a path forward to a rapid (sample-to-answer time ≤3 hours), accurate, sensitive, species-specific, and portable system to detect the presence of MDR combat-related wound infections in the field environment. Our future efforts involve ruggedizing the RAPID system and evaluating performance under relevant environmental conditions. [ABSTRACT FROM AUTHOR]

AbstractA critical limitation in developing portable Fourier transform-infrared (FTIR) stand-off chemical detectors is the library optimization which reduces the number of false alarms and maintains the performance. Ideally, a library should be established through high-resolution (0.5 cm−1) FTIR spectroscopy in the laboratory. However, due to the weight requirements of a portable FTIR stand-off detector, its optical system and mirror-moving range have limitations. Consequently, most portable FTIR stand-off detectors have been developed with a low resolution of approximately 4 to 16 cm−1. In this study, we developed a portable FTIR stand-off detector with a dual library of SF6. Moreover, we investigated its detection efficiency depending on the single library condition through realistic long-range (3 km) SF6 spectra in a field test. [ABSTRACT FROM AUTHOR]

Background: Chitosan due to biodegradable and non-toxic characteristics has versatile applications. Extraction and characterization of Chitosan from Snail Shells In January, 2023 Achatina fulica was performed. Methods: A chemical process involving demineralization and deproteinization was utilized to extract 2000g Chitin from Achatina fulica shells. To produce chitosan, the chitin was subjected to deacetylation. The chitosan was subsequently characterized using Fourier Transform Infrared spectroscopy, X-ray diffraction, and Scanning Electron Microscopy. The physicochemical charactristics and mineral compositionswere investigated and the data were analyzed using the Statistical Package for Social Sciences (SPSS) software version 20.0. Results: The chitosan obtained from the process was 75%. It exhibited a Degree Of Deacetylation of 82.31%, a molecular weight of 2.65×105 g/mol, an intrinsic viscosity of 1,007.2 mg/g, and a solubility of 70%. The pH value of chitosan in acetic acid solution was recorded at 6.38, with a solubility of 70%. The proximate analysis revealed moisture, ash, fat, protein, crude fiber, and carbohydrate contents of 0.32, 0.72, 2.01, 0.13, 0.15, and 96.67%, respectively. The mineral analysis revealed sodium, potassium, calcium, magnesium, phosphorus, iron, and zinc concentrations of 32.10, 21.80, 721, 288.60, 123.75, 41.77, and 8.48 mg/g, respectively. X-ray diffraction analysis identified the region characterized by the presence of calcite and calcium phosphate, indicating residual minerals in the extracted chitosan, which contribute to its crystalline structure. Fourier Transform Infrared spectroscopy demonstrated functional groups such as amino and hydroxyl groups, whereas Scanning Electron Microscopy reported an irregular particle size with rough surfaces and a microfibrillar crystalline structure. Conclusion: The current investigation has the potential to promote the sustainable use of a locally abundant yet underutilized resource, assisting in waste reduction and creation of innovative bioactive materials which could be applied in food preservation, pharmaceuticals, and medical devices. [ABSTRACT FROM AUTHOR]

The simultaneous occurrence of various pollutants in the aquatic environment raises questions about their mutual interactions. There is a gap in research on the sorption of polar substances on microplastics. This study aimed to assess the adsorption of the antidepressants sertraline, fluoxetine and duloxetine on microplastic polystyrene, polyethylene terephthalate and polyvinyl chloride, each in two versions: virgin and aged. To assess the affinity of the tested drugs for plastic and planktonic organisms, the experiment was conducted in microplastic suspensions and in a mixture of microplastics with the protozoan Spirostomum ambiguum. The Fourier transform infrared technique assessed the identity of microplastics and changes during ageing. No significant differences were found between the sorption of the tested drugs on virgin and aged microplastics. The sorption of sertraline onto microplastics was 1.5–3 times lower in the presence of the protozoa than in samples with microplastics alone. Moreover, its concentration in the protozoan cells was 10–30 times higher than in the microplastics. Considering that the amount of plankton in freshwaters is much greater than that of microplastics, it should be concluded that microplastics have a negligible share in the transport of antidepressants in surface waters. [ABSTRACT FROM AUTHOR]

This study aimed to systematically find an alternative solvent to replace hexane for the extraction of bio-oil with high γ-oryzanol content from rice bran (RB). The selection involved predicting solubility through Hansen solubility theory, experimental validation, determination of suitable extraction conditions, and comparison of oil quality with that of conventional hexane. A wide variety of solvents: subcritical water (SCW), supercritical carbon dioxide (SCCO2), bio-based solvents (alcohols and terpenes), and liquefied dimethyl ether (LDME), were initially assessed for rice bran oil (RBO) and γ-oryzanol solubility using Hansen solubility spheres. Solvents demonstrating high solubility for both RBO and γ-oryzanol, including LDME, ethyl acetate, acetone, and others (alcohols and SCCO2) known for effective vegetable oil extraction, were selected/identified for experimental extraction comparison. Among these, LDME performed better overall, affording greater solubility and requiring less solvent, shorter duration, lower pressure, and no additional co-solvents for equivalent extractions. Optimal conditions for LDME extraction were identified as 30 °C with a solvent-to-sample ratio of 10 mL/g and an extraction time of 10 min. Oils extracted with LDME and hexane displayed similar fatty acid compositions and no adverse effects on RB protein and carbohydrate structures after LDME extraction were observed. This study demonstrates LDME as a promising alternative to replace hexane for RBO extraction to further valorize this abundant low-cost RB residue into bio-oil and its γ-oryzanol and de-oil RB co-products.

Background: Chitosan due to biodegradable and non-toxic characteristics has versatile applications. Extraction and characterization of Chitosan from Snail Shells In January, 2023 Achatina fulica was performed. Methods: A chemical process involving demineralization and deproteinization was utilized to extract 2000g Chitin from Achatina fulica shells. To produce chitosan, the chitin was subjected to deacetylation. The chitosan was subsequently characterized using Fourier Transform Infrared spectroscopy, X-ray diffraction, and Scanning Electron Microscopy. The physicochemical charactristics and mineral compositionswere investigated and the data were analyzed using the Statistical Package for Social Sciences (SPSS) software version 20.0. Results: The chitosan obtained from the process was 75%. It exhibited a Degree Of Deacetylation of 82.31%, a molecular weight of 2.65×105 g/mol, an intrinsic viscosity of 1,007.2 mg/g, and a solubility of 70%. The pH value of chitosan in acetic acid solution was recorded at 6.38, with a solubility of 70%. The proximate analysis revealed moisture, ash, fat, protein, crude fiber, and carbohydrate contents of 0.32, 0.72, 2.01, 0.13, 0.15, and 96.67%, respectively.The mineral analysis revealed sodium, potassium, calcium, magnesium, phosphorus, iron, and zinc concentrations of 32.10, 21.80, 721, 288.60, 123.75, 41.77, and 8.48 mg/g, respectively. X-ray diffraction analysis identified the region characterized by the presence of calcite and calcium phosphate, indicating residual minerals in the extracted chitosan, which contribute to its crystalline structure. Fourier Transform Infrared spectroscopy demonstrated functional groups such as amino and hydroxyl groups, whereas Scanning Electron Microscopy reported an irregular particle size with rough surfaces and a microfibrillar crystalline structure. Conclusion: The current investigation has the potential to promote the sustainable use of a locally abundant yet underutilized resource, assisting in waste reduction and creation of innovative bioactive materials which could be applied in food preservation, pharmaceuticals, and medical devices. DOI: 10.18502/jfqhc.11.3.16590

This paper presents a study on the interlaminar shear strength (ILSS) retention of three types of glass fiber–reinforced polymer (GFRP) bars with different surface textures subjected to four types of conditioning environments (alkaline, alkaline, salt, acidic, and water) at two temperature levels (ambient laboratory and high temperature) for 3, 6, and 12 months. The conditioning temperature plays a critical role in reducing the strength of the bars. Scanning electron microscopy revealed the extent of damage to the fibers, resin, interface, and fracture morphologies in the cross sections. The causes of fiber cracking and lower strength upon exposure were validated by point energy-dispersive X-ray spectroscopy analyses, which detected the leaching of silicon from the fiber structure. Prediction models using multiple linear regression (MLR) and artificial neural networks (ANNs) were developed using Matrix Laboratory (MATLAB R2023b) software and compared. The coefficients of determination of the MLR and ANN prediction models were found to be 0.29 and 0.90, respectively, indicating the superiority of machine learning–based models in identifying and accounting for nonlinearities and highlighting their potential application in GFRP bars. Finally, the correlation between the transverse shear strength (TSS) and ILSS of the tested GFRP bars was identified. The ILSS of the bars was found to be approximately 0.26 times the TSS for any given conditioning scenario. [ABSTRACT FROM AUTHOR]

Direct-on-Filter (DoF) analysis of respirable crystalline silica (RCS) by Fourier Transform Infrared (FTIR) spectroscopy is a useful tool for assessing exposure risks. With the RCS exposure limits becoming lower, it is important to characterize and reduce measurement uncertainties. This study systematically evaluated two filter types (i.e., polyvinyl chloride [PVC] and polytetrafluoroethylene [PTFE]) for RCS measurements by DoF FTIR spectroscopy, including the filter-to-filter and day-to-day variability of blank filter FTIR reference spectra, particle deposition patterns, filtration efficiencies, and pressure drops. For PVC filters sampled at a flow rate of 2.5 L/min for 8 h, the RCS limit of detection (LOD) was 7.4 μg/m3 when a designated laboratory reference filter was used to correct the absorption by the filter media. When the spectrum of the pre-sample filter (blank filter before dust sampling) was used for correction, the LOD could be up to 5.9 μg/m3. The PVC absorption increased linearly with reference filter mass, providing a means to correct the absorption differences between the pre-sample and reference filters. For PTFE, the LODs were 12 and 1.2 μg/m3 when a designated laboratory blank or the pre-sample filter spectrum was used for blank correction, respectively, indicating that using the pre-sample blank spectrum will reduce RCS quantification uncertainty. Both filter types exhibited a consistent radially symmetric deposition pattern when particles were collected using 3-piece cassettes, indicating that RCS can be quantified from a single measurement at the filter center. The most penetrating aerodynamic diameters were around 0.1 µm with filtration efficiencies ≥ 98.8% across the measured particle size range with low-pressure drops (0.2–0.3 kPa) at a flow rate of 2.5 L/min. This study concludes that either the PVC or the PTFE filters are suitable for RCS analysis by DoF FTIR, but proper methods are needed to account for the variability of blank absorption among different filters. [ABSTRACT FROM AUTHOR]

We present new aspects of erbium- or ytterbium-doped pure gadolinium oxide (Gd2O3:Er3+/Yb3+) as a suitable candidate for drug delivery and magnetic resonance (MR) applications. The samples were prepared using the conventional sol–gel synthesis technique. The structural studies revealed that the prepared sample was monophased and crystallizes in a cubic structure. FTIR measurements confirmed the creation of Gd2O3:Er3+/Yb3+ phosphor. SEM micrographs clearly indicated that the particles crystallized in uniform shape, exhibiting nano-rod formation, with the particle size ranging from 55 to 5 nm. TEM images revealed that Er3+- and Yb3+-co-doped Gd2O3 nanoparticles were the collection of the nano-rods 2–4 nm thick and 18–20 nm long. Also, photoluminescence analysis of the phosphor samples for variable concentrations of doping ions was presented. When doped with Er3+/Yb3+, nano-rod Gd2O3 emits intense green emission and some red emission peaks, under a 980-nm near-infrared laser. Our study shows that as-prepared samples may be useful for optical imaging systems and that nano-rod formation may be used as a major host carrier for drug delivery. [ABSTRACT FROM AUTHOR]

Summary: Ultrasonication is a novel, green, and sustainable method to modify the native starch for improved functionality and pronounced industrial applications. In the present study, the impact of ultrasonication power (40%, 50%, and 60%) on black wheat starch was observed on functional and pasta‐making attributes. Ultrasonication induced surface and microstructural alterations with minimal impact on the overall integrity of starch granules. The sound waves disrupted starch granules through cavitation and starch degradation by radial attack. Scanning electron microscope (SEM) images revealed that ultrasonication disrupted the starch granules and a porous structure was developed. The treatment induced fissures and pores formation leading to structural rearrangements without any impact at the molecular level. With the increment in the power of ultrasonication, the scratching and fissures on the starch granules are increased which further modifies the starch functionality. Due to structural disruption of long amylopectin helices into short‐chain amylopectin and dextrin resulted in a more crystalline structure of starch, the results were supported by X‐ray diffraction (XRD) and Fourier transform infrared (FTIR) spectra. This alteration in starch structure increased the amylose concentration, solubility, and swelling capacity of modified starch. Pasta prepared with modified starch shows improved cooking and textural properties. [ABSTRACT FROM AUTHOR]

Leaf extracts are known to be rich in phytoconstituent biomolecules, making them a valuable source of medicinal compounds. They also serve as both capping and reducing agents in nanoparticle fabrication. A reaction between CuSO4.5H2O aqueous solution and the Indigofera tinctoria leaf extract results in the formation of stable copper nanoparticles. Phytochemical screening of the Indigofera tinctoria leaf extract revealed the presence of various compounds including carbohydrates, terpenoids, phenol, tannins, flavonoids, saponins, and glycosides in the sample. The biosynthesized copper nanoparticles (CuNPs) were subsequently subjected to various forms of analysis. Techniques used included UV-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy. An observable change in the color of solutions from pale to thick brown indicated the formation of CuNPs. Further confirmation came from UV-vis spectroscopy, which established the production of CuNPs at 500 nm. FTIR analysis revealed that the CuNPs were covered by organic residues. The particles ranged from 210 nm to 260 nm as indicated from the SEM analysis. [ABSTRACT FROM AUTHOR]

Chemical warfare agents pose a serious threat due to their extreme toxicity, necessitating swift the identification of chemical gases and individual responses to the identified threats. Fourier transform infrared (FTIR) spectroscopy offers a method for remote material analysis, particularly in detecting colorless and odorless chemical agents. In this paper, we propose a deep neural network utilizing a semi-supervised autoencoder (SSAE) for the classification of chemical gases based on FTIR spectra. In contrast to traditional methods, the SSAE concurrently trains an autoencoder and a classifier attached to a latent vector of the autoencoder, enhancing feature extraction for classification. The SSAE was evaluated on laboratory-collected FTIR spectra, demonstrating a superior classification performance compared to existing methods. The efficacy of the SSAE lies in its ability to generate denser cluster distributions in latent vectors, thereby enhancing gas classification. This study established a consistent experimental environment for hyperparameter optimization, offering valuable insights into the influence of latent vectors on classification performance. [ABSTRACT FROM AUTHOR]

Due to rising environmental awareness and dwindling oil supplies, many efforts have been made to replace synthetic fibres with plant fibre reinforced composites (PFRC). The need to eliminate plastics from everyday life has resulted in the development of a diverse range of eco-friendly natural-based composites for the automotive, chemical, and food packaging industries. PFRC plays an important role in the production of lightweight and cost-effective products. The current study looked at how different proportions of SiC/Al2O3 filler affected the mechanical properties of a plant fibre-based ramie/jute epoxy hybrid composite. By reinforcing a constant ramie (20 wt.%) and jute (10 wt.%) fibre with different proportions of SiC (2 –10 wt.%) and Al2O3 (0 –8 wt.%), hybrid composites were created using traditional stirring and compression moulding methods. The hybrid composite with 8% SiC and 2% Al2O3 (sample D) has higher tensile, flexural, hardness, impact, and interlaminar shear strength than the other combinations. The functional group of a nanoparticle-filled hybrid composite was evaluated using Fourier Transfer infrared Spectroscopy. Furthermore, SEM confirmed the excellent bonding of the viable hybrid composite combination's filler, fibre, and matrix. According to the findings, a nano filler content of 8% SiC and 2% Al2O3 can improve mechanical properties and serve as a viable reinforcement in hybrid polymer composites for major engineering applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study was undertaken to determine the amount and type of microplastics in different milk samples. MATERIAL AND METHODS: Sample collection was done from branded, dairy, and directly from the cow shed and was then transferred to a conical flask. Containers were wrapped with aluminum foil to avoid contamination of the samples. A total of 100 mL of 5% sodium chloride solution was added to 200 mL of milk sample, rotated for 2 min, and was kept to undergo density separation for 15 min in a water bath. Whatman filter paper Grade I of pore size 11 µm is used for filtration. The samples were filtered using a vacuum filtration setup with a vacuum pressure of 0.5 bar pressure and stored in clean Petri dishes. These were kept in a hot air oven for drying at 60°C for 3 h and at room temperature for 24 h for complete drying of the filter paper. RESULTS: Fourier transform infrared analyses determined that the polystyrene type of microplastics was higher, showing red, blue, violet, and green colors by microscopic analysis. CONCLUSION: Three categories of milk samples (branded, dairy, and cowshed) were taken and analyzed, the results showed more microplastics in branded milk packets than in dairy and fresh cowshed milk samples which are lower than other food products.

Time-resolved step-scan Fourier transform infrared difference spectroscopy has been used to study cyanobacterial photosystem I photosynthetic reaction centers from Synechocystis sp. PCC 6803 (S6803) with four high-potential, 1,4-naphthoquinones incorporated into the A1 binding site. The high-potential naphthoquinones are 2-chloro-, 2-bromo-, 2,3-dichloro- and 2,3-dibromo-1,4-naphthoquinone. "Foreign minus native" double difference spectra (DDS) were constructed by subtracting difference spectra for native photosystem I (with phylloquinone in the A1 binding site) from corresponding spectra obtained using photosystem I with the different quinones incorporated. To help assess and assign bands in the difference and double difference spectra, density functional theory based vibrational frequency calculations for the different quinones in solvent, or in the presence of a single asymmetric H- bond to either a water molecule or a peptide backbone NH group, were undertaken. Calculated and experimental spectra agree best for the peptide backbone asymmetrically H- bonded system. By comparing multiple sets of double difference spectra, several new bands for the native quinone (phylloquinone) are identified. By comparing calculated and experimental spectra we conclude that the mono-substituted halogenated NQs can occupy the binding site in either of two different orientations, with the chlorine or bromine atom being either ortho or meta to the H- bonded CO group.

Due to a legacy originating in the limited capability of early computers, the spectroscopic resolution used in Fourier transform infrared spectroscopy and other systems has largely been implemented using only powers of two for more than 50 years. In this study, we investigate debunking the spectroscopic lore of, e.g., using only 2, 4, 8, or 16 cm−1 resolution and determine the optimal resolution in terms of both (i) a desired signal-to-noise ratio and (ii) efficient use of acquisition time. The study is facilitated by the availability of solids and liquids reference spectral data recorded at 2.0 cm−1 resolution and is based on an examination in the 4000–400 cm−1 range of 61 liquids and 70 solids spectra, with a total analysis of 4237 peaks, each of which was also examined for being singlet/multiplet in nature. Of the 1765 liquid bands examined, only 27 had widths <5 cm−1. Of the 2472 solid bands examined, only 39 peaks have widths <5 cm−1. For both the liquid and solid bands, a skewed distribution of peak widths was observed: For liquids, the mean peak width was 24.7 cm−1 but the median peak width was 13.7 cm−1, and, similarly, for solids, the mean peak width was 22.2 cm−1 but the median peak width was 11.2 cm−1. While recognizing other studies may differ in scope and limiting the analysis to only room temperature data, we have found that a resolution to resolve 95% of all bands is 5.7 cm−1 for liquids and 5.3 cm−1 for solids; such a resolution would capture the native linewidth (not accounting for instrumental broadening) for 95% of all the solids and liquid bands, respectively. After decades of measuring liquids and solids at 4, 8, or 16 cm−1 resolution, we suggest that, when accounting only for intrinsic linewidths, an optimized resolution of 6.0 cm−1 will capture 91% of all condensed-phase bands, i.e., broadening of only 9% of the narrowest of bands, but yielding a large gain in signal-to-noise with minimal loss of specificity. [ABSTRACT FROM AUTHOR]

In the present work, a combination of virgin polypropylene and E-glass fiber was subjected to ten (10) reprocessing cycles via extrusion and compression molding techniques to mimic recycling and its impacts on the bending properties of the composites. The samples were characterized using Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM), and melt flow index (MFI). The results revealed a gradual depreciation in flexural properties after each reprocessing cycle. The XRD analysis indicated a substantial reduction of peak intensities, degrees of crystallinities, and average crystallite sizes, explaining the lowered flexural properties in addition to a possible reduction in glass fiber lengths (fiber attrition). Melt-processing behavior shows a progressive increase of MFI from 7 to 19.16 g/10 min, confirming the probable damage in molecular weight and loss of complex viscosity. Chemical and structural analysis showed no alteration in the polypropylene major functional groups. It is concluded that the reductions in molecular weight and composites' properties occurred due to chain scission from recycling effects; hence, glass fiber-reinforced polypropylene composites can be recycled only three (3) times unless it is refreshed by the addition of virgin parts to compensate for the lost property. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study was undertaken to determine the amount and type of microplastics in different milk samples. MATERIAL AND METHODS: Sample collection was done from branded, dairy, and directly from the cow shed and was then transferred to a conical flask. Containers were wrapped with aluminum foil to avoid contamination of the samples. A total of 100 mL of 5% sodium chloride solution was added to 200 mL of milk sample, rotated for 2 min, and was kept to undergo density separation for 15 min in a water bath. Whatman filter paper Grade I of pore size 11 µm is used for filtration. The samples were filtered using a vacuum filtration setup with a vacuum pressure of 0.5 bar pressure and stored in clean Petri dishes. These were kept in a hot air oven for drying at 60°C for 3 h and at room temperature for 24 h for complete drying of the filter paper. RESULTS: Fourier transform infrared analyses determined that the polystyrene type of microplastics was higher, showing red, blue, violet, and green colors by microscopic analysis. CONCLUSION: Three categories of milk samples (branded, dairy, and cowshed) were taken and analyzed, the results showed more microplastics in branded milk packets than in dairy and fresh cowshed milk samples which are lower than other food products. [ABSTRACT FROM AUTHOR]

Guar seed flour (GSF) has a high amount of carbohydrates, proteins, phytochemicals, and anti‐nutritional factors (ANFs), which limits its use. To address this issue, the current study was undertaken to understand the effect of microwave (MW) irradiation on ANFs, phytochemicals, in vitro protein digestibility (IVPD), and functional attributes of GSF at varying power density (Pd: 1–3 W/g) and duration (3–9 min). The ANFs were determined using a colorimetric assay and a Fourier transform infrared spectrum. At 3 Pd‐9 min, the maximum reduction in ANFs (tannin, phytic acid, saponin, and trypsin inhibitor activity) was observed. Higher Pd and treatment duration increased antioxidant activity and total phenolic content, except for total flavonoid content. Furthermore, compared to the control sample (78.38%), the IVPD of the GSF samples increased to 3.28% (3 Pd‐9 min). An increase in Pd and duration of MW treatment improved the thermal and pasting properties of GSF samples up to 2 Pd‐9 min. Due to inter‐ and intramolecular hydrogen bonding degradation, the relative crystallinity of the 3 Pd‐9 min treated GSF sample was 30.58%, which was lower than that of the control (40.08%). In MW‐treated samples, SEM images revealed smaller clusters with rough and porous structures. However, no noticeable color (ΔE) changes were observed in MW‐treated samples. Aside from water absorption capacity and water solubility index, MW treatment reduced oil absorption capacity, foaming capacity, and emulsifying capacity. As demonstrated by principal component analysis, MW irradiation with moderate Pd (2–3) was more effective in reducing ANFs, retaining nutritional contents, and improving the digestible properties of GSF, which could be a potential ingredient for developing gluten‐free products. [ABSTRACT FROM AUTHOR]

This article provides a review of the phytochemical constituents and pharmacological activities of Anisomeles malabarica, a plant native to India and Sri Lanka. It is known for its anti-inflammatory, anti-allergic, anti-cancer, anti-diabetic, and anti-bacterial properties. Traditional medicine uses it to treat various health problems such as dyspepsia, rheumatism, wound healing, and teething problems in children. The article also discusses cultivation practices, medicinal value, phytochemical constituents, and pharmacological activities of A. malabarica. It concludes that the plant has significant medicinal value and should be further studied and utilized for its therapeutic benefits. [Extracted from the article]

BACKGROUND AND OBJECTIVES: Low-density polyethylene is one of the dominant recalcitrant plastic pollutants in the ocean, thus causing complicated problems. Biodegradation is an efficient, environmentally friendly, and sustainable option to overcome these problems. This study aims to quantitatively and qualitatively analyze the ability of marine bacterial isolates to degrade lowdensity polyethylene plastic. METHODS: Bacteria were isolated from plastic samples using serial dilution technique and inoculated on media containing low-density polyethylene powder. Bacterial degradation ability was analyzed quantitatively based on weight loss percentage and energy-dispersive X-ray spectroscopy values, as well as qualitatively based on changes in physical and chemical structures using Scanning Electron Microscopy and Fourier transform infrared spectroscopy. Meanwhile, bacterial isolates were identified based on gene sequence and phylogenetic analyses. FINDINGS: Four bacterial isolates were isolated from low-density polyethylene plastic samples. Quantitative analysis found that the low-density polyethylene film experienced weight loss up to 10-15 percent during 35 days of incubation, with a maximum daily weight loss rate of 0.004 milligrams per day, meaning that the four bacterial isolates have the potential to degrade plastic. Meanwhile, qualitative analysis based on Scanning Electron Microscope observations revealed changes in the physical structure of the film surface in the form of a rough surface, formation of holes, and breakdown into clumps across the film surface. Variations in these changes were tested. In the control, no changes occurred and the film surface remained flat and smooth. Conversely, the results of the energy dispersive X-ray spectroscopy spectrum analysis showed that the lowdensity polyethylene film broke down into smaller fragments, characterized by a decrease in mass from 98.51 percent to 98.23 percent. Fourier transform infrared observations showed variations in transmittance and wavenumbers, indicating changes in chemical bonds or functional groups in the low-density polyethylene film which caused it to become brittle and break down into smaller fragments with a lower molecular weight, making it easier for bacteria to digest. The results of the gene sequence analysis identified four bacterial isolates, namely Lysinibacillus sp. IBP-1, Bacillus sp. IBP-2, Bacillus paramycoides IBP-3, and Bacillus cereus IBP-4. Based on the quantitative and qualitative analyses, the ability of the bacterial isolates to degrade low-density polyethylene film was shown in the following order: Bacillus paramycoides IBP-3 > Bacillus cereus IBP-4 > Lysinibacillus sp. IBP-1 > Bacillus sp. IBP-2. CONCLUSION: All four marine bacterial isolates can use low-density polyethylene as the sole carbon source. Based on quantitative and qualitative analyses, Bacillus paramycoides IBP-3 has the best potential for degrading low-density polyethylene film. This study provides information on potential bacterial isolates that can be developed to control low-density polyethylene plastic waste. [ABSTRACT FROM AUTHOR]

Silicone rubber (SiR) is known for its exceptional electrical insulation properties. The performance of SiR could be affected by many factors, including processing parameters, particularly mixing speed and time. While these parameters are crucial for ensuring the homogeneity of blended polymeric materials, their electrical impact remains relatively unexplored. This research investigates the effect of varying processing parameters on SiR samples during rapid aging under the incline plane tracking (IPT) test. The study unfolds in three phases, with the final IPT stage revealing the significant influence of different mixing speeds and times on the recorded leakage current (LC) values for each sample. Sample 2, subjected to 70 rpm mixing speed and 10 minutes of mixing time, exhibited great resistance to tracking and erosion. Fourier transform infrared spectroscopy (FTIR) was conducted on the samples before and after the IPT test to further analyze the impact of the varying processing parameters. Once again, sample 2 displayed notable resilience, demonstrating lower reductions in absorbance values for key functional groups. In conclusion, the specific processing parameters of 70 rpm and 10 minutes have been shown to positively influence the performance of SiR, enhancing their resistance to tracking and erosion during rapid aging. [ABSTRACT FROM AUTHOR]

The study compared high‐pressure, microwave, ultrasonic, and traditional extraction techniques. The following extraction conditions were implemented: microwave‐assisted extraction (MAE) at 900 W power for durations of 30, 60, and 90 s; ultrasonic‐assisted extraction (UAE) at 100% amplitude for periods of 5, 10, and 15 min; and high‐pressure processing (HPP) at pressures of 400 and 500 MPa for durations of 1, 5, and 10 min. The highest yield in terms of total phenolic content (PC) was obtained in UAE with a value of 45.13 ± 1.09 mg gallic acid equivalent (GAE)/100 g fresh weight (FW). The highest PC content was determined using HPP‐500 MPa for 10 min, resulting in 40 mg GAE/100 g, and MAE for 90 s, yielding 34.40 mg GAE/100 g FW. The highest value of antioxidant activity (AA) was obtained by UAE in 51.9% ± 0.71%. The PCs were identified through the utilization of Fourier transform infrared (FTIR) spectroscopy and high‐performance liquid chromatography (HPLC). Utilizing multivariate analysis, the construction of chemometric models were executed to predict AA or total PC of the extracts, leveraging the information from IR spectra. The FTIR spectrum revealed bands associated with apigenin, and the application of HPP resulted in concentrations of 5.41 ± 0.25 mg/100 g FW for apigenin and 1.30 ± 0.15 mg/100 g FW for protocatechuic acid. Furthermore, HPLC analysis detected the presence of protocatechuic acid, caffeic acid, p‐coumaric acid, and apigenin in both green extraction methods and the classical method. Apigenin emerged as the predominant phenolic compound in peach extracts. The highest concentrations of apigenin, p‐coumaric acid, and protocatechuic acid were observed under HPP treatment, measuring 5.41 ± 0.25, 0.21 ± 0.04, and 1.30 ± 0.15 mg/kg FW, respectively. [ABSTRACT FROM AUTHOR]

The warm-mix flame retardant composite modified asphalt was prepared with warm-mix agent (Sasobit), aluminum hydroxide (ATH), organic montmorillonite (OMMT) and base asphalt, and fourier transform infrared (FTIR) scanning, thermogravimetric (TG) analysis and differential scanning calorimetry were used to investigate the coordination and synergistic effect of warm-mix agent and flame retardant and the flame retardant mechanism. The results show that the modification effect of warm-mix agent and flame retardant on the base asphalt is mainly physical modification. The addition of flame retardant can improve the thermal stability, flame retardant and smoke suppression effects of asphalt, and the flame retardant, smoke suppression effects are improved with the increasing of the amount of flame retardant. The flame retardant can form barrier coating on the asphalt surface with wrapping effect, which can effectively reduce the heat flow rate with excellent flame retardant efficiency and combustion process control ability. The compounded flame retardants of ATH and OMMT can provide the synergistic flame retardant effect, and the flame retardant mechanisms are mainly heat exchange interruption and condensed phase flame retardant. When the compounded flame retardant content is 8%, the asphalt has good flame retardant and smoke suppression properties with good economy. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Low-density polyethylene is one of the dominant recalcitrant plastic pollutants in the ocean, thus causing complicated problems. Biodegradation is an efficient, environmentally friendly, and sustainable option to overcome these problems. This study aims to quantitatively and qualitatively analyze the ability of marine bacterial isolates to degrade low-density polyethylene plastic.METHODS: Bacteria were isolated from plastic samples using serial dilution technique and inoculated on media containing low-density polyethylene powder. Bacterial degradation ability was analyzed quantitatively based on weight loss percentage and energy-dispersive X-ray spectroscopy values, as well as qualitatively based on changes in physical and chemical structures using Scanning Electron Microscopy and Fourier transform infrared spectroscopy. Meanwhile, bacterial isolates were identified based on gene sequence and phylogenetic analyses.FINDINGS: Four bacterial isolates were isolated from low-density polyethylene plastic samples. Quantitative analysis found that the low-density polyethylene film experienced weight loss up to 10-15 percent during 35 days of incubation, with a maximum daily weight loss rate of 0.004 milligrams per day, meaning that the four bacterial isolates have the potential to degrade plastic. Meanwhile, qualitative analysis based on Scanning Electron Microscope observations revealed changes in the physical structure of the film surface in the form of a rough surface, formation of holes, and breakdown into clumps across the film surface. Variations in these changes were tested. In the control, no changes occurred and the film surface remained flat and smooth. Conversely, the results of the energy dispersive X-ray spectroscopy spectrum analysis showed that the low-density polyethylene film broke down into smaller fragments, characterized by a decrease in mass from 98.51 percent to 98.23 percent. Fourier transform infrared observations showed variations in transmittance and wavenumbers, indicating changes in chemical bonds or functional groups in the low-density polyethylene film which caused it to become brittle and break down into smaller fragments with a lower molecular weight, making it easier for bacteria to digest. The results of the gene sequence analysis identified four bacterial isolates, namely Lysinibacillus sp. IBP-1, Bacillus sp. IBP-2, Bacillus paramycoides IBP-3, and Bacillus cereus IBP-4. Based on the quantitative and qualitative analyses, the ability of the bacterial isolates to degrade low-density polyethylene film was shown in the following order: Bacillus paramycoides IBP-3 > Bacillus cereus IBP-4 > Lysinibacillus sp. IBP-1 > Bacillus sp. IBP-2.CONCLUSION: All four marine bacterial isolates can use low-density polyethylene as the sole carbon source. Based on quantitative and qualitative analyses, Bacillus paramycoides IBP-3 has the best potential for degrading low-density polyethylene film. This study provides information on potential bacterial isolates that can be developed to control low-density polyethylene plastic waste.

Backgraound: Polysaccharides, particularly Carboxymethyl Cellulose (CMC) and Ammoniacum Gum (AMG), are considered valuable due to their thermal stability and non-toxicity. CMC has good film-forming ability but weak mechanical properties, while AMG shows promise with its unique chemical composition. Additionally, essential oils, such as Clove Essential Oil (CEO), are being used to enhance the antimicrobial properties of edible films, offering a natural way to extend the shelf life of food products. Methods: This study investigated the combined effect of CMC: 0.5-1.5 wt %, AMG: 1-5 wt %, as well as CEO: 0-30 v/v % on the physical characteristics of the CMC-AMG films by Response Surface Methodology. The optimization was performed with the aim of maximizing Whiteness Index, Ultimate Tensile Strength (UTS), and Strain at Break (SB) and minimizing total color difference (ΔE) values. Fourier-Transform Infrared Spectroscopy, film microstructure, Differential Scanning Calorimeter analysis, and antibacterial activity were investigated. The analysis was conducted using Design Expert software version 10.00 (STAT-EASE Inc., Minneapolis, USA). Result: The films with the highest UTS have been obtained through a composition of 5 g CMC, 1.5 g AMG, and 15% CEO. On the contrary, using a composition of 5 g CMC, 1 g AMG, and 30% CEO revealed the highest SB (115.41%). The highest UTS value of 13.17 MPa was obtained with a formulation consisting of 5% AMG, 1.5% CMC, and 15% CEO. Nevertheless, the maximum SB value of 115.41% was achieved with a formulation containing 5% AMG, 1% CMC, and 30% CEO. Moreover, heterogeneous microstructure and more opaque films were obtained as identified by the higher ΔE. The Differential Scanning Calorimeter results demonstrated that incorporating a CEO did not impinge on thermal stability. Furthermore, the addition of CEO led to a rise in antimicrobial activity against Salmonella enterica, Pseudomonas fluorescens, Escherichia coli, and Listeria monocytogenes. Conclusion: In conclusion, combination of CMC and AMG in optimum levels, led to the production of a film with acceptable mechanical properties. Also, these films showed significant antimicrobial activity. DOI: 10.18502/jfqhc.10.4.14178

The simultaneous occurrence of various pollutants in the aquatic environment raises questions about their mutual interactions. There is a gap in research on the sorption of polar substances on microplastics. This study aimed to assess the adsorption of the antidepressants sertraline, fluoxetine and duloxetine on microplastic polystyrene, polyethylene terephthalate and polyvinyl chloride, each in two versions: virgin and aged. To assess the affinity of the tested drugs for plastic and planktonic organisms, the experiment was conducted in microplastic suspensions and in a mixture of microplastics with the protozoan Spirostomum ambiguum. The Fourier transform infrared technique assessed the identity of microplastics and changes during ageing. No significant differences were found between the sorption of the tested drugs on virgin and aged microplastics. The sorption of sertraline onto microplastics was 1.5–3 times lower in the presence of the protozoa than in samples with microplastics alone. Moreover, its concentration in the protozoan cells was 10–30 times higher than in the microplastics. Considering that the amount of plankton in freshwaters is much greater than that of microplastics, it should be concluded that microplastics have a negligible share in the transport of antidepressants in surface waters.

Background Efficient infection control during carbapenem-resistant Enterobacterales outbreaks demands rapid and simple techniques for outbreak investigations. WGS, the current gold standard for outbreak identification, is expensive, time-consuming and requires a high level of expertise. Fourier-transform infrared (FTIR) spectroscopy (IR Biotyper) is a rapid typing method based on infrared radiation applied to samples, which provides a highly specific absorption spectrum. Objectives To investigate an outbreak of OXA-48-producing Escherichia coli in real-time using FTIR and subsequently compare the results with WGS. Methods Twenty-one isolates were collected during a nosocomial outbreak, and identification and antibiotic susceptibilities were confirmed by VITEK®2. FTIR was conducted for all isolates, and nine representative isolates were sequenced. Results FTIR was able to correctly determine the clonal relatedness of the isolates and to identify the outbreak cluster, as confirmed by WGS. By WGS, isolates in the main FTIR cluster belonged to the same MLST type and core-genome MLST type, and they harboured similar plasmids and resistance genes, whereas the singletons external to the FTIR cluster had different genetic content. Conclusions FTIR can operate as a rapid, efficient and reliable first-line tool for outbreak investigations during a real-time ongoing E. coli outbreak, which can contribute to limiting the spread of pathogens. [ABSTRACT FROM AUTHOR]

Secondary metabolites from sea urchin shells contain active substances with the potential of antibiotics. The purpose of this study was to investigate how sea urchin shell extract affected the development of the Staphylococcus bacterium. In this kind of research, the active chemical content of sea urchin shell extract was examined quantitatively, using scanning electron microscope (SEM) and Fourier Transform Infrared (FTIR), as well as the extract's effect on the development of Staphylococcus aureus bacteria. According to the study, the average level of total flavonoids was 1.29 %, total alkaloids were 0.12 %, and total tannins were 1.0 %. Sea urchin shell powder has an absorbance of 0.42 at a wavelength of 1,400.84 cm-1. According to microbiological experiments, sea urchin shell ethyl acetate extract was able to stop Staphylococcus aureus growth in the category of the strong inhibition zone (inhibition zone diameter of 12 mm). Extract from sea urchin shells has antibacterial properties and may be used to make anti-diabetic ointments. This fabrication is a fantastic option for use in healthcare and medicine. [ABSTRACT FROM AUTHOR]

Bituminous binders are foreseen as colloidal dispersed systems characterised by high chemical complexity containing a plethora of molecules classified into maltenes and asphaltenes. The effect of these fractions on the overall response of bituminous binders remains elusive. This research selected two binders from the same refinery but with different paving grades. First, Dynamic Shear and Bending Beam Rheometers were employed to assess their rheological properties, and results were consistent with the physical measurements conducted on binders to address low to high temperature rheological response. Then, the binders and their fractions were individually analysed in a Fourier transform infrared spectroscopy and differential scanning calorimetry to elucidate their chemistry associated with the structural changes. No significant difference could be noticed in the infrared spectra of binders, even if they displayed diverse physical properties. Differences may be identified in asphaltenes, an observation which is also supported by calorimetric measurements where steric hindrance occurred upon heating. Maltenes contributed significantly to the glass transition of both binders, while the impact of asphaltenes on the heat capacity changes in glass transition was limited. The findings from this research could be used to establish a new analytical approach for bituminous binders to understand the differences in the physical properties of binders based on their chemistry. [ABSTRACT FROM AUTHOR]

Cardiovascular surgery has a high risk of neurological complications, which can increase the burden of disease. Perioperative real-time monitoring of neurological function in cardiovascular surgery can assist clinicians to detect neurological abnormalities as early as possible, intervene and reduce the risk of neurological complications in time. The main monitoring indicators include cerebral oxygen saturation (ScO2), EEG, cerebral blood flow (CBF), etc. In this paper, the common perioperative neuromonitoring techniques and their research advances in cardiovascular surgery are reviewed to provide theoretical basis for reducing neurological complications and improve the prognosis of patients. [ABSTRACT FROM AUTHOR]

Backgraound: Polysaccharides, particularly Carboxymethyl Cellulose (CMC) and Ammoniacum Gum (AMG), are considered valuable due to their thermal stability and non-toxicity. CMC has good film-forming ability but weak mechanical properties, while AMG shows promise with its unique chemical composition. Additionally, essential oils, such as Clove Essential Oil (CEO), are being used to enhance the antimicrobial properties of edible films, offering a natural way to extend the shelf life of food products. Methods: This study investigated the combined effect of CMC: 0.5-1.5 wt %, AMG: 1-5 wt %, as well as CEO: 0-30 v/v % on the physical characteristics of the CMC-AMG films by Response Surface Methodology. The optimization was performed with the aim of maximizing Whiteness Index, Ultimate Tensile Strength (UTS), and Strain at Break (SB) and minimizing total color difference (E) values. Fourier-Transform Infrared Spectroscopy, film microstructure, Differential Scanning Calorimeter analysis, and antibacterial activity were investigated. The analysis was conducted using Design Expert software version 10.00 (STAT-EASE Inc., Minneapolis, USA). Result: The films with the highest UTS have been obtained through a composition of 5 g CMC, 1.5 g AMG, and 15% CEO. On the contrary, using a composition of 5 g CMC, 1 g AMG, and 30% CEO revealed the highest SB (115.41%). The highest UTS value of 13.17 MPa was obtained with a formulation consisting of 5% AMG, 1.5% CMC, and 15% CEO. Nevertheless, the maximum SB value of 115.41% was achieved with a formulation containing 5% AMG, 1% CMC, and 30% CEO. Moreover, heterogeneous microstructure and more opaque films were obtained as identified by the higher ?E. The Differential Scanning Calorimeter results demonstrated that incorporating a CEO did not impinge on thermal stability. Furthermore, the addition of CEO led to a rise in antimicrobial activity against Salmonella enterica, Pseudomonas fluorescens, Escherichia coli, and Listeria monocytogenes. Conclusion: In conclusion, combination of CMC and AMG in optimum levels, led to the production of a film with acceptable mechanical properties. Also, these films showed significant antimicrobial activity. [ABSTRACT FROM AUTHOR]

Peatlands are climate critical carbon (C) reservoirs that could become a C source under continued warming. A strong relationship between plant tissue chemistry and the soil organic matter (SOM) that fuels C gas emissions is inferred, but rarely examined at the molecular level. Here we compared Fourier transform infrared (FT-IR) spectroscopy measurements of solid phase functionalities in plants and SOM to ultra-high-resolution mass spectrometric analyses of plant and SOM water extracts across a palsa-bog-fen thaw and moisture gradient in an Arctic peatland. From these analyses we calculated the C oxidation state (NOSC), a measure which can be used to assess organic matter quality. Palsa plant extracts had the highest NOSC, indicating high quality, whereas extracts of Sphagnum, which dominated the bog, had the lowest NOSC. The percentage of plant compounds that are less bioavailable and accumulate in the peat, increases from palsa (25%) to fen (41%) to bog (47%), reflecting the pattern of percent Sphagnum cover. The pattern of NOSC in the plant extracts was consistent with the high number of consumed compounds in the palsa and low number of consumed compounds in the bog. However, in the FT-IR analysis of the solid phase bog peat, carbohydrate content was high implying high quality SOM. We explain this discrepancy as the result of low solubilization of bog SOM facilitated by the low pH in the bog which makes the solid phase carbohydrates less available to microbial decomposition. Plant-associated condensed aromatics, tannins, and lignin-like compounds declined in the unsaturated palsa peat indicating decomposition, but lignin-like compounds accumulated in the bog and fen peat where decomposition was presumably inhibited by the anaerobic conditions. A molecular-level comparison of the aboveground C sources and peat SOM demonstrates that climate-associated vegetation shifts in peatlands are important controls on the mechanisms underlying changing C gas emissions.

Dandelion root contains triterpenoids, polyphenols and flavonoids, dandelion leaf is rich in polyphenols, flavonoids, flavonoids glycosides, and dandelion flower mainly contains flavonoids, among other substances. These different substance content leads to specific benefits and function effects of each part. Fourier transform infrared spectroscopy, three-dimensional fluorescence spectroscopy and related multivariate statistical methods are widely used to determine sample characteristics, but limited research focuses on the substance difference and characteristics in dandelion tissues. In this paper, Fourier transform infrared spectra-principal component analysis and three-dimensional fluorescence spectroscopy-parallel factor analysis were conveyed to analyze dandelion stem, leaf, root and flower tissue extracts, for determining the substance species and content difference among dandelion tissues and evaluating the discrimination capacity of these analysis methods. The Fourier transform infrared spectroscopy of root was distinct from others, and the two principal component models could distinguish dandelion stem and flower, but failed to differentiate leaf and root; while the excitation and emission matrix showed that stem and flower, leaf and root had similar intensity band distribution but different fluorescence intensity, and the parallel factor analysis results proved that one- and three-component models cannot differentiate the tissues of stem and flower, leaf and root, since the fluorescent compounds (polyphenol, flavonoid etc.) structure and content were similar in different tissues. These results indicated that Fourier transform infrared-principal component analysis might be a useful method when various fluorescent compounds exist.

The three-dimensional structure of the synthetic lung Surfactant Protein B Peptide Super Mini-B was determined using an integrative experimental approach, including mass spectrometry and isotope enhanced Fourier-transform infrared (FTIR) spectroscopy. Mass spectral analysis of the peptide, oxidized by solvent assisted region-specific disulfide formation, confirmed that the correct folding and disulfide pairing could be facilitated using two different oxidative structure-promoting solvent systems. Residue specific analysis by isotope enhanced FTIR indicated that the N-terminal and C-terminal domains have well defined α-helical amino acid sequences. Using these experimentally derived measures of distance constraints and disulfide connectivity, the ensemble was further refined with molecular dynamics to provide a medium resolution, residue-specific structure for the peptide construct in a simulated synthetic lung surfactant lipid multilayer environment. The disulfide connectivity combined with the α-helical elements stabilize the peptide conformationally to form a helical hairpin structure that resembles critical elements of the Saposin protein fold of the predicted full-length Surfactant Protein B structure.

Chemical warfare agents pose a serious threat due to their extreme toxicity, necessitating swift the identification of chemical gases and individual responses to the identified threats. Fourier transform infrared (FTIR) spectroscopy offers a method for remote material analysis, particularly in detecting colorless and odorless chemical agents. In this paper, we propose a deep neural network utilizing a semi-supervised autoencoder (SSAE) for the classification of chemical gases based on FTIR spectra. In contrast to traditional methods, the SSAE concurrently trains an autoencoder and a classifier attached to a latent vector of the autoencoder, enhancing feature extraction for classification. The SSAE was evaluated on laboratory-collected FTIR spectra, demonstrating a superior classification performance compared to existing methods. The efficacy of the SSAE lies in its ability to generate denser cluster distributions in latent vectors, thereby enhancing gas classification. This study established a consistent experimental environment for hyperparameter optimization, offering valuable insights into the influence of latent vectors on classification performance.

The development of a method for identification and determination of thiamphenicol by Fourier Transform Infrared will provide convenience to developers because it is fast and easy for analysis. The research was carried out by utilizing the solubility of thiamphenicol in methanol with three stages, namely method development, sample analysis, and method validation. The method development stage showed that the specific peak of thiamphenicol was at a peak with a wavenumber of 1694.1 cm−1; this specific peak of thiamphenicol was used for qualitative analysis and quantitative analysis of thiamphenicol in the capsule dosage form. The sample analysis showed that all analyzed thiamphenicol in capsule dosage form showed good results both qualitatively and quantitatively. Qualitatively all the samples analyzed showed a specific peak at specific positions and specific wavenumbers. These results meet the requirements for containing thiamphenicol in the dosage form. Quantitatively all the samples analyzed ranged from 97.97% to 102.24% by peak height and peak area. These results meet the requirements for active substance levels in general preparations within 90.0% to 110.0%. The method validation for peak height and peak area showed that the accuracy parameter had a recovery percentage of 100.28% and 100.41% (between 98.0% to 102.0%), the precision parameter with a relative standard deviation of 0.31% and 0.37% (not more than 2.0%), and the linearity parameter with a correlation coefficient of 0.9999 and 0.9997 (not less than 0.99). The limit of detection value was 0.2971 mg/mL and 0.5338 mg/mL, the limit of quantitation value was 0.9004 mg/mL and 1.6176 mg/mL, the range for both was 80% to 120%, and the specificity for both met the requirement. The Fourier Transform Infrared method has been successfully developed, applied, and validated for qualitative analysis and quantitative analysis of thiamphenicol in capsule dosage form.

Copyright of Tikrit Journal of Engineering Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Self-assembling peptides have shown tremendous potential in the fields of material sciences, nanoscience, and medicine. Because of the vast combinatorial space of even short peptides, identification of self-assembling sequences remains a challenge. Herein, we develop an experimental method to rapidly screen a huge array of peptide sequences for self-assembling property, using the one-bead one-compound (OBOC) combinatorial library method. In this approach, peptides on beads are N-terminally capped with nitro-1,2,3-benzoxadiazole, a hydrophobicity-sensitive fluorescence molecule. Beads displaying self-assembling peptides would fluoresce under aqueous environment. Using this approach, we identify eight pentapeptides, all of which are able to self-assemble into nanoparticles or nanofibers. Some of them are able to interact with and are taken up efficiently by HeLa cells. Intracellular distribution varied among these non-toxic peptidic nanoparticles. This simple screening strategy has enabled rapid identification of self-assembling peptides suitable for the development of nanostructures for various biomedical and material applications.

Enkephalins are small opioid peptides whose binding conformations are catalyzed by phospholipid membranes. Binding to opioid receptors is determined by the orientation of tyrosine and phenylalanine side chains. In this work, we investigate the effects of different charged phospholipid headgroups on the insertion of the tyrosine side chain into a lipid bilayer using a combination of 2D IR spectroscopy, anharmonic DFT calculations, and third order response function modeling. The insertion is probed by using the ∼1515 cm-1 tyrosine ring breathing mode, which we found exhibits rich vibrational dynamics on the picosecond timescale. These dynamics include rapid intramolecular vibrational energy redistribution (IVR), where some of the energy ends up in a dark state that shows up as an anharmonically shifted combination band. The waiting-time dependent 2D IR spectra also show an unusual line shape distortion that affects the extraction of the frequency-frequency correlation function (FFCF), which is the dynamic observable of interest that reflects the tyrosine side chain's insertion into the lipid bilayer. We proposed three models to account for this distortion: a hot-state exchange model, a local environment dependent IVR model, and a coherence transfer model. A qualitative analysis of these models suggests that the local environment dependent IVR rate best explains the line shape distortion, while the coherence transfer model best reproduced the effects on the FFCF. Even with these complex dynamics, we found that the tyrosine ring mode's FFCF is qualitatively correlated with the degree of insertion expected from the different phospholipid headgroups.

Background: Zayandeh-rud river is the most important river in the central regions of Iran and the present study aimed to provide new insights into microplastics (MPs) pollution in surface water and sediments of this river. Methods: Water and sediment samples were collected in July 2021 from 19 sampling sites along the river. Organics matters were removed from the samples by wet peroxide oxidation (WPO), and MPs were extracted by floatation in ZnCl2-saturated salt and filtration on a polytetrafluoroethylene (PTFE) membrane filter. Trapped MPs on the filter were counted and qualified by a stereomicroscope. Results: MPs were found in 13 sites from 19 sampling sites along the river. The minimum and maximum levels of MPs in water samples were 0 and 51 ± 16.5 particles/m3, respectively. MPs also were detected in the sediments of all sampling sites except the first two sampling sites (the maximum level was 58 ± 25.9 particles/kg as dry sediment). Fragments were the most common shape of MPs in both water and sediment samples. 72.3% of MPs detected in water samples were 1-5 mm in size, while this percentage for sediment was 49.2%. The five main polymer types found in water and sediment samples were polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). Conclusion: These levels of MPs in the water and sediments of Zayandeh-rud river and longtime persistence of plastics in the environment is a significant threat to environmental and human health and need serious attention to restrict MPs release into the river.

Abstract In this work, the binding mechanism between donepezil (DNP) and bovine serum albumin (BSA) was established using several techniques, including fluorimetry, UV- spectrophotometry, synchronous fluorimetry (SF), fourier transform infrared (FTIR), fluorescence resonance energy transfer (FRET) besides molecular docking study. The fluorescence quenching mechanism of DNP-BSA binding was a combined dynamic and static quenching. The thermodynamic parameters, binding forces, binding constant, and the number of binding sites were determined using a different range of temperature settings. Van't Hoff's equation was used to calculate the reaction parameters, including enthalpy change (ΔHο) and entropy change (ΔSο). The results pointed out that the DNP-BSA binding was endothermic. It was shown that the stability of the drug-protein system was predominantly due to the intermolecular hydrophobic forces. Additionally, the site probing method revealed that subdomain IIA (Site I) is where DNP and BSA's binding occurs. This was validated using a molecular docking study with the most stable DNP configuration. This study might help to understand DNP's pharmacokinetics profile and toxicity as well as provides crucial information for its safe use and avoiding its toxicity.

Composites of metal-organic frameworks and carbon materials have been suggested to be effective materials for the decomposition of chemical warfare agents. In this study, we synthesized UiO-66-NH2/zeolite-templated carbon (ZTC) composites for the adsorption and decomposition of the nerve agents sarin and soman. UiO-66-NH2/ZTC composites with good dispersion were prepared via a solvothermal method. Characterization studies showed that the composites had higher specific surface areas than pristine UiO-66-NH2, with broad pore size distributions centered at 1-2 nm. Owing to their porous nature, the UiO-66-NH2/ZTC composites could adsorb more water at 80% relative humidity. Among the UiO-66-NH2/ZTC composites, U0.8Z0.2 showed the best degradation performance. Characterization and gas adsorption studies revealed that beta-ZTC in U0.8Z0.2 provided additional adsorption and degradation sites for nerve agents. Among the investigated materials, including the pristine materials, U0.8Z0.2 also exhibited the best protection performance against the nerve agents. These results demonstrate that U0.8Z0.2 has the optimal composition for exploiting the degradation performance of pristine UiO-66-NH2 and the adsorption performance of pristine beta-ZTC.