Rheological Properties and 3D Printing Behavior of PCL and DMSO2 Composites for Bio-Scaffold.

The significance of rheology in the context of bio three-dimensional (3D) printing lies in its impact on the printing behavior, which shapes material flow and the layer-by-layer stacking process. The objective of this study is to evaluate the rheological and printing behaviors of polycaprolactone (PCL) and dimethyl sulfone (DMSO2) composites. The rheological properties were examined using a rotational rheometer, employing a frequency sweep test. Simultaneously, the printing behavior was investigated using a material extrusion 3D printer, encompassing varying printing temperatures and pressures. Across the temperature range of 120-140 °C, both PCL and PCL/DMSO2 composites demonstrated liquid-like behavior, with a higher loss modulus than storage modulus. This behavior exhibited shear-thinning characteristics. The addition of DMSO2 10, 20, and 30 wt% into the PCL matrix reduced a zero-shear viscosity of 33, 46, and 74% compared to PCL, respectively. The materials exhibited extrusion velocities spanning from 0.0850 to 6.58 mm/s, with velocity being governed by the reciprocal of viscosity. A significant alteration in viscosity by temperature change directly led to a pronounced fluctuation in extrusion velocity. Extrusion velocities below 0.21 mm/s led to the production of unstable printed lines. The presence of distinct viscosities altered extrusion velocity, flow rate, and strut diameter. This phenomenon allowed the categorization of pore shape into three zones: irregular, normal, and no-pore zones. It underscored the importance of comprehending the rheological aspects of biomaterials in enhancing the overall quality of bio-scaffolds during the 3D printing process.

Deep Learning Model for Cosmetic Gel Classification Based on a Short-Time Fourier Transform and Spectrogram.

Cosmetics and topical medications, such as gels, foams, creams, and lotions, are viscoelastic substances that are applied to the skin or mucous membranes. The human perception of these materials is complex and involves multiple sensory modalities. Traditional panel-based sensory evaluations have limitations due to individual differences in sensory receptors and factors such as age, race, and gender. Therefore, this study proposes a deep-learning-based method for systematically analyzing and effectively identifying the physical properties of cosmetic gels. Time-series friction signals generated by rubbing the gels were measured. These signals were preprocessed through short-time Fourier transform (STFT) and continuous wavelet transform (CWT), respectively, and the frequency factors that change over time were distinguished and analyzed. The deep learning model employed a ResNet-based convolution neural network (CNN) structure with optimization achieved through a learning rate scheduler. The optimized STFT-based 2D CNN model outperforms the CWT-based 2D and 1D CNN models. The optimized STFT-based 2D CNN model also demonstrated robustness and reliability through k-fold cross-validation. This study suggests the potential for an innovative approach to replace traditional expert panel evaluations and objectively assess the user experience of cosmetics.

Fabrication of a Three-Dimensional Microfluidic System from Poly(methyl methacrylate) (PMMA) Using an Intermiscibility Vacuum Bonding Technique.

In this study, the fabrication of microfluidic chips through the bonding of poly (methyl methacrylate) (PMMA) boards featuring designed patterns to create a three-dimensional sandwich structure with embedded microchannels was explored. A key focus was optimization of the interface quality of bonded PMMA pairs by adjusting the solvent, such as such as acetone, alcohol, and their mixture. Annealing was conducted below 50 °C to leverage the advantages of low-temperature bonding. Because of the differences in the chemical reactivity of PMMA toward acetone, alcohol, and their combinations, the resulting defect densities at the bonding interfaces differed significantly under low-temperature annealing conditions. To achieve the optimal sealing integrity, bonding pressures of 30 N, 40 N, and 50 N were evaluated. The interface was analyzed through microstructural examination via optical microscopy and stress measurements were determined using digital photoelasticity, while the bonding strength was assessed through tensile testing.

Complete genome sequence of Arthrobacter sp. KFRI-F3372, a strain isolated from Korean soybean paste Doenjang.

Arthrobacter sp. KFRI-F3372 is a Gram-positive bacterium with a high G + C content of 65.7%, which was isolated from Doenjang, a traditional Korean fermented soybean paste. In this report, we introduce the complete genome sequence of Arthrobacter sp. KFRI-F3372.

Monitoring of 137Cs, 239+240Pu, and 90Sr in the marine environment of South Korea and their impact on marine biota: 10 years after the Fukushima accident.

This study conducted an analysis of the behavior of radionuclides and assessment their radioactive risk based on seawater and seabed sediment samples gathered from the East, South, and Yellow Seas of South Korea over the period from 2011 to 2020. The distribution for each radionuclides in seawater obtained from the East, South, and Yellow Seas were similar. However, the concentrations of 137Cs and 239+240Pu in sediments from the East Sea were observed to be higher compared to those from the South and Yellow Seas. This variation can be attributed to differences in the ocean inflow, water column properties, and seabed characteristics among the seas around South Korea. There were no statistically significant differences between the radioactive concentrations of seawater and seabed samples collected before and after the Fukushima accident, and no areas with unusually high radiation levels were detected. Using the distribution coefficient (Kds) and the concentration ratio (CR) calculated from the 2011-to-2020 data, we evaluated the radiological impact on fish. The ERICA tool was utilized to assess these data, and indicated a negligible radiological risk from radioactivity in the seawater, seabed sediments, and marine biota in the South Korean Ocean.

The Effect of Vacuum Films on Physicochemical and Microbiological Characteristics of Hanwoo (Korean Native Cattle).

The objective of this study was to investigate the physicochemical and microbiological characteristics of round of Hanwoo by vacuum packaging film materials, polyvinylidene chloride (PVDC) and ethylene vinyl alcohol (EVOH). The packaged beef samples were stored in refrigerated conditions (2±1°C) for 12 weeks. Physicochemical analysis with pH, surface color, thiobarbituric acid reactive substances (TBARS) values, and volatile basic nitrogen (VBN) values and microbiological analysis with aerobic plate count (APC) and metagenomic analysis of packaged beef samples were performed. The pH and surface color did not change substantially during the 12 weeks and EVOH-packaged beef tended to be lower than those of PVDC-packaged beef. PVDC- and EVOH-packaged samples showed low TBARS and VBN values below standard limits. APC did not exceed 7 Log CFU/g for both samples during storage. In metagenomic analysis, Firmicutes and Lactobacillaceae were dominant phylum and family of the PVDC- and EVOH-packaged beef. In both packaged samples, Dellaglioa algida was the dominant species during storage, with the notable difference being the presence of Lactococcus piscium. Therefore, this study provided the information on the quality of vacuum-packaged beef according to different vacuum films for long-term refrigerated storage.

Assessment of radiological impact on the surrounding environment and biota for phosphogypsum waste stockyard in Korean facility.

In this study, the effects of deposited gypsum residues on the surrounding environment and radiation exposure in plants and animals were evaluated under various exposure situations. A waste stockyard in a Korean facility (surrounded by mountains and sea) was used to store phosphogypsum, a byproduct of phosphoric acid processes, in a slurry form in a large gypsum storage facility (provided separately on the facility site). The ERICA tool was used to evaluate the impact of radiation on nonhuman environments for mineral processing and waste storage for risk estimation. The impact of radiation on the environment due to the phosphogypsum stockyard was negligible with a screening dose of less than 10 µGy h-1. However, to conservatively evaluate the environmental impact of rain and wind in the phosphogypsum stockyard, the soil at the interface of the stockyard, where plants could not grow, was considered as an input value, and the estimated dose rate of shrubs was found to be 45 µGy h-1. The effects of the phosphogypsum stockyard on the surrounding environment accounted for 95-100% of the total dose for internal exposure in biota. In general, radium was found to be the highest contributor to biota, and the next lead and polonium were contributors to the dose. The findings contribute to an understanding of the radiological impact of waste stored and disposed of at the facility on the environment and biota (all routes of exposure) and to developing sustainable operations and pollution monitoring policies.

PCL and DMSO2 Composites for Bio-Scaffold Materials.

Polycaprolactone (PCL) has been one of the most popular biomaterials in tissue engineering due to its relatively low melting temperature, excellent thermal stability, and cost-effectiveness. However, its low cell attraction, low elastic modulus, and long-term degradation time have limited its application in a wide range of scaffold studies. Dimethyl sulfone (DMSO2) is a stable and non-hazardous organosulfur compound with low viscosity and high surface tension. PCL and DMSO2 composites may overcome the limitations of PCL as a biomaterial and tailor the properties of biocomposites. In this study, PCL and DMSO2 composites were investigated as a new bio-scaffold material to increase hydrophilicity and mechanical properties and tailor degradation properties in vitro. PCL and DMSO2 were physically mixed with 10, 20, and 30 wt% of DMSO2 to evaluate thermal, hydrophilicity, mechanical, and degradation properties of the composites. The water contact angle of the composites for hydrophilicity decreased by 15.5% compared to pure PCL. The experimental results showed that the mechanical and degradation properties of PCL and DMSO2 were better than those of pure PCL, and the properties can be tuned by regulating DMSO2 concentration in the PCL matrix. The elastic modulus of the composite with 30 wt% of DMSO2 showed 532 MPa, and its degradation time was 18 times faster than that of PCL.

Accurate measurement of uranium and thorium in naturally occurring radioactive materials to overcome complex matrix interference.

A standard addition (SA) calibration method for determining uranium and thorium in naturally-occurring radioactive materials (NORMs) was studied. Pretreatment method using fusion was established and optimized. The SA method was validated (LOD, LOQ, linearity, selectivity, and accuracy) using certified reference materials (SRM 2709a, RM-ZR, and RM-BX). The results were evaluated for bias, and a correction equation that included a contribution to the expanded uncertainty was used. All performance criteria were satisfied; the results agreed well with certified and reference values.

Multi-biomarker panel prediction model for diagnosis of pancreatic cancer.

BACKGROUND/PURPOSE: The current study aimed to develop a prediction model using a multi-marker panel as a diagnostic screening tool for pancreatic ductal adenocarcinoma. METHODS: Multi-center cohort of 1991 blood samples were collected from January 2011 to September 2019, of which 609 were normal, 145 were other cancer (colorectal, thyroid, and breast cancer), 314 were pancreatic benign disease, and 923 were pancreatic ductal adenocarcinoma. The automated multi-biomarker Enzyme-Linked Immunosorbent Assay kit was developed using three potential biomarkers: LRG1, TTR, and CA 19-9. Using a logistic regression model on a training data set, the predicted values for pancreatic ductal adenocarcinoma were obtained, and the result was classification into one of the three risk groups: low, intermediate, and high. The five covariates used to create the model were sex, age, and three biomarkers. RESULTS: Participants were categorized into four groups as normal (n = 609), other cancer (n = 145), pancreatic benign disease (n = 314), and pancreatic ductal adenocarcinoma (n = 923). The normal, other cancer, and pancreatic benign disease groups were clubbed into the non-pancreatic ductal adenocarcinoma group (n = 1068). The positive and negative predictive value, sensitivity, and specificity were 94.12, 90.40, 93.81, and 90.86, respectively. CONCLUSIONS: This study demonstrates a significant diagnostic performance of the multi-marker panel in distinguishing pancreatic ductal adenocarcinoma from normal and benign pancreatic disease states, as well as patients with other cancers.

Musical Novices Are Unable to Judge Musical Quality from Brief Video Clips: A Failed Replication of Tsay (2014).

Research focusing on "thin slicing" suggests in making judgements of others' moods, personality traits, and relationships, we are able to make relatively reliable decisions based on a small amount of information. In some instances, this can be done in a matter of a few seconds. A similar result was found with regard to the judgement of musical quality of ensemble performances by Tsay (2014), wherein musical novices were able to reliably choose the winner of a music competition based on the visual information only (but not auditory or audiovisual information). Tsay argues that this occurs due to a lack of auditory expertise in musical novices, and that they are able to extract quality information based on visual movements with more accuracy. As part of the SCORE project (OSF, 2021), we conducted a direct replication of Tsay (2014). Findings showed that musical novices were unable to judge musical quality at a level greater than chance, and this result held for auditory, visual, and audiovisual presentation. This suggests that 6 s is not a sufficient amount of time for novices to judge the relative quality of musical performance, regardless of the modality in which they were presented.

Conformational rearrangements upon start codon recognition in human 48S translation initiation complex.

Selection of the translation start codon is a key step during protein synthesis in human cells. We obtained cryo-EM structures of human 48S initiation complexes and characterized the intermediates of codon recognition by kinetic methods using eIF1A as a reporter. Both approaches capture two distinct ribosome populations formed on an mRNA with a cognate AUG codon in the presence of eIF1, eIF1A, eIF2-GTP-Met-tRNAiMet and eIF3. The 'open' 40S subunit conformation differs from the human 48S scanning complex and represents an intermediate preceding the codon recognition step. The 'closed' form is similar to reported structures of complexes from yeast and mammals formed upon codon recognition, except for the orientation of eIF1A, which is unique in our structure. Kinetic experiments show how various initiation factors mediate the population distribution of open and closed conformations until 60S subunit docking. Our results provide insights into the timing and structure of human translation initiation intermediates and suggest the differences in the mechanisms of start codon selection between mammals and yeast.

Novel Fabrication of Silver-Coated Copper Nanowires with Organic Compound Solution.

Copper nanowires and Cu-Ag nanowires have various potential applications, such as transparent conductive film, flexible electronics, and conductive filler. In this study, we developed a new green fabrication method for silver-coated copper nanowires using methylsulfonylmethane (DMSO2), which is an environmentally friendly chemical at the food-grade level, to replace toxic chemicals, including ammonia, in the silver coating process. Copper nanowires were synthesized under various reaction temperatures and concentrations of hydrazine (N2H4), ethylenediamine (EDA), sodium hydroxide (NaOH), and copper precursor. The reaction temperature higher than 70 °C caused the oxidation of copper products and evaporation of the sample solution. The optimal conditions to synthesize copper nanowires more than 18 µm in length and 25-45 nm in diameter were determined: 9 M of NaOH, 50 µL of EDA, 17 mM of CuCl2, 5.7 mM of N2H4, and 70 °C reaction temperature. Cu-Ag nanowires, which have about a 12 nm thick silver shell, were successfully fabricated at room temperature under 1 mM of silver nitrate (AgNO3) and 1 wt % of DMSO2. Synthesis conditions for copper and silver-coated copper nanowires have been optimized.

Flexible Pyroresistive Graphene Composites for Artificial Thermosensation Differentiating Materials and Solvent Types.

When we touch an object, thermosensation allows us to perceive not only the temperature but also wetness and types of materials with different thermophysical properties (i.e., thermal conductivity and heat capacity) of objects. Emulation of such sensory abilities is important in robots, wearables, and haptic interfaces, but it is challenging because they are not directly perceptible sensations but rather learned abilities via sensory experiences. Emulating the thermosensation of human skin, we introduce an artificial thermosensation based on an intelligent thermo-/calorimeter (TCM) that can objectively differentiate types of contact materials and solvents with different thermophysical properties. We demonstrate a TCM based on pyroresistive composites with ultrahigh sensitivity (11.2% °C-1) and high accuracy (<0.1 °C) by precisely controlling the melt-induced volume expansion of a semicrystalline polymer, as well as the negative temperature coefficient of reduced graphene oxide. In addition, the ultrathin TCM with coplanar electrode design shows deformation-insensitive temperature sensing, facilitating wearable skin temperature monitoring with accuracy higher than a commercial thermometer. Moreover, the TCM with a high pyroresistivity can objectively differentiate types of contact materials and solvents with different thermophysical properties. In a proof-of-principle application, our intelligent TCM, coupled with a machine-learning algorithm, enables objective evaluation of the thermal attributes (coolness and wetness) of skincare products.

Insight into the molecular basis of substrate recognition by the wall teichoic acid glycosyltransferase TagA.

Wall teichoic acid (WTA) polymers are covalently affixed to the Gram-positive bacterial cell wall and have important functions in cell elongation, cell morphology, biofilm formation, and ß-lactam antibiotic resistance. The first committed step in WTA biosynthesis is catalyzed by the TagA glycosyltransferase (also called TarA), a peripheral membrane protein that produces the conserved linkage unit, which joins WTA to the cell wall peptidoglycan. TagA contains a conserved GT26 core domain followed by a C-terminal polypeptide tail that is important for catalysis and membrane binding. Here, we report the crystal structure of the Thermoanaerobacter italicus TagA enzyme bound to UDP-N-acetyl-d-mannosamine, revealing the molecular basis of substrate binding. Native MS experiments support the model that only monomeric TagA is enzymatically active and that it is stabilized by membrane binding. Molecular dynamics simulations and enzyme activity measurements indicate that the C-terminal polypeptide tail facilitates catalysis by encapsulating the UDP-N-acetyl-d-mannosamine substrate, presenting three highly conserved arginine residues to the active site that are important for catalysis (R214, R221, and R224). From these data, we present a mechanistic model of catalysis that ascribes functions for these residues. This work could facilitate the development of new antimicrobial compounds that disrupt WTA biosynthesis in pathogenic bacteria.

Electronic wastes: A near inexhaustible and an unimaginably wealthy resource for water splitting electrocatalysts.

E-wastes comprise complex combinations of potentially toxic elements that cause detrimental effects of the environmental contamination; besides their posing threat, most of the products also contain valuable and recoverable materials (Li, Au, Ag, W, Se, Te, etc.), which make them distinct from other forms of industrial wastes. Most of these value-added elements which are primarily employed in electronic goods are disposed of by incineration and land-filling. This is a serious issue besides just environmental pollution, as IUPAC recognized that such ignorance of or poor attention to e-waste recycling has put several elements in the periodic table to the list of endangered elements. Recycling these wastes utilized for electrocatalytic water splitting to produce H2. These recovered e-wastes materials are used as electrocatalysts for the water-splitting, additives to enhance reaction kinetics, and substrate electrodes as well. Recycling and recovery of value-added materials in the view of applying them to electrocatalytic water splitting with endangered elements' perspective have not been covered by any recent review so far. Hence, this review is dedicated to discussing the opportunities available with recycling e-wastes, types of value-added materials that can be recovered for water splitting, strategies exploited, and prospects are discussed in details.

Characteristics of Bacterial Strains with Desirable Flavor Compounds from Korean Traditional Fermented Soybean Paste (Doenjang).

To identify and analyze the characteristics of the microorganisms involved in the formation of the desirable flavor of Doenjang, a total of 179 strains were isolated from ninety-four Doenjang collected from six regions in South Korea, and fourteen strains were selected through a sensory evaluation of the aroma of each culture. The enzyme activities of amylase, protease and lipase was shown in the various strains. Bacillus sp.-K3, Bacillus sp.-K4 and Bacillus amyloliquefaciens-J2 showed relatively high protease activity, at 317.1 U, 317.3 U and 319.5 U, respectively. The Bacillus sp.-K1 showed the highest lipase activity at 2453.6 U. In the case of amylase, Bacillus subtilis-H6 showed the highest activity at 4105.5 U. The results of the PCA showed that Bacillus subtilis-H2, Bacillus subtilis-H3, and Bacillus sp.-K2 were closely related to the production of 3-hydroxy-2-butanone (23.51%~43.37%), and that Bacillus subtilis-H5 and Bacillus amyloliquefaciens-J2 were significantly associated with the production of phenethyl alcohol (0.39% and 0.37%). The production of peptides was observed to vary among the Bacillus cultures such as Val-Val-Pro-Pro-Phe-Leu and Pro-Ala-Glu-Val-Leu-Asp-Ile. These peptides are precursors of related volatile flavor compounds created in Doenjang via the enzymatic or non-enzymatic route; it is expected that these strains could be used to enhance the flavor of Doenjang.

The Green Synthesis of 2D Copper Nanosheets and Their Light Absorption.

In this study, a new green synthesis method for two-dimensional (2D) copper nanosheets is developed using methylsulfonylmethane (DMSO2). The chemical composition and light absorption of 2D copper nanosheets are also studied. A new green method is mainly to utilize DMSO2, which is environmentally friendly enough to be considered a food-grade chemical, unlike the conventional method using toxic chemicals, such as ammonia and hydrazine (N2H4). With a reducing agent, the aggregation of uncertain copper products was produced in the absence of DMSO2, while 2D copper nanosheets were formed in the presence of DMSO2. The optimum concentration of DMSO2 as a surfactant was determined to be 2 M, resulting in large surface areas with regular edges. FTIR spectrum confirmed C-H bonding from DMSO2 used to synthesize 2D copper nanosheets. The light absorption peak was revealed at 800 nm in the UV-vis spectrum. This proposed new green method not only has a simpler process than the conventional methods, such as hydrothermal method and chemical bath deposition, but also substitutes toxic chemicals with DMSO2. 2D copper nanosheets can be used for various applications, including conductive filler or ink in the flexible electronics and laser photonics fields.

Design and Synthesis of Small Molecules as Potent Staphylococcus aureus Sortase A Inhibitors.

The widespread and uncontrollable emergence of antibiotic-resistant bacteria, especially methicillin-resistant Staphylococcus aureus, has promoted a wave of efforts to discover a new generation of antibiotics that prevent or treat bacterial infections neither as bactericides nor bacteriostats. Due to its crucial role in virulence and its nonessentiality in bacterial survival, sortase A has been considered as a great target for new antibiotics. Sortase A inhibitors have emerged as promising alternative antivirulence agents against bacteria. Herein, the structural and preparative aspects of some small synthetic organic compounds that block the pathogenic action of sortase A have been described.

A Cell-based Screen in Actinomyces oris to Identify Sortase Inhibitors.

Sortase enzymes are attractive antivirulence drug targets that attach virulence factors to the surface of Staphylococcus aureus and other medically significant bacterial pathogens. Prior efforts to discover a useful sortase inhibitor have relied upon an in vitro activity assay in which the enzyme is removed from its native site on the bacterial surface and truncated to improve solubility. To discover inhibitors that are effective in inactivating sortases in vivo, we developed and implemented a novel cell-based screen using Actinomyces oris, a key colonizer in the development of oral biofilms. A. oris is unique because it exhibits sortase-dependent growth in cell culture, providing a robust phenotype for high throughput screening (HTS). Three molecules representing two unique scaffolds were discovered by HTS and disrupt surface protein display in intact cells and inhibit enzyme activity in vitro. This represents the first HTS for sortase inhibitors that relies on the simple metric of cellular growth and suggests that A. oris may be a useful platform for discovery efforts targeting sortase.