bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupled Thermal-Hydraulic Analysis and Species Mass Transport in a Versatile Experimental Salt Irradiation Loop (VESIL) Using CTF
Authors: Walker Samuel A. , Abou-Jaoude Abdalla , Taylor Zack , Salko Robert K. , Ji Wei
Published: August 2021

With the resurgence of interest in molten salt reactors, there is a need for new experiments and modeling capabilities to characterize the unique phenomena present in this fluid fuel system. A Versatile Experimental Salt Irradiation Loop (VESIL) is currently under investigation at Idaho National Laboratory to be placed in the Advanced Test Reactor (ATR). One of the key phenomena this proposed experiment plans to elucidate is fission product speciation in the fuel-salt and the subsequent effects this has on the fuel-salt properties, source term generation, and corrosion control. Specifically, noble gases (Xe & Kr) will bubble out to a plenum or off-gas system, and noble metals (Mo, Tc, Te, etc.) will precipitate and deposit in specific zones in the loop. This work extends the mass transfer and species interaction models in CTF (Coolant-Boiling in Rod Arrays—Two Fluids) and applies these models to give a preliminary estimation of fission product behavior in the proposed VESIL design. A noble metal–helium bubble mass transfer model is coupled with the thermal-hydraulic results from CTF to determine the effectiveness of this insoluble fission product (IFP) extraction method for VESIL. Amounts of IFP species extracted to the off-gas system and species distributions in VESIL after a 60-day ATR cycle are reported.
A New PCR-Based Assay for Testing Bronchoalveolar Lavage Fluid Samples from Patients with Suspected Pneumocystis jirovecii Pneumonia
Authors: Liotti Flora Marzia , Posteraro Brunella , De Angelis Giulia , Torelli Riccardo , De Carolis Elena , Speziale Domenico , Menchinelli Giulia , Spanu Teresa , Sanguinetti Maurizio
Published: August 2021

To support the clinical laboratory diagnosis of Pneumocystis jirovecii (PJ) pneumonia (PCP), an invasive fungal infection mainly occurring in HIV-negative patients, in-house or commercial PJ-specific real-time quantitative PCR (qPCR) assays are todays’ reliable options. The performance of these assays depends on the type of PJ gene (multi-copy mitochondrial versus single-copy nuclear) targeted by the assay. We described the development of a PJ-PCR assay targeting the dihydrofolate reductase (DHFR)-encoding gene. After delineating its analytical performance, the PJ-PCR assay was used to test bronchoalveolar lavage (BAL) fluid samples from 200 patients (only seven were HIV positive) with suspected PCP. Of 211 BAL fluid samples, 18 (8.5%) were positive and 193 (91.5%) were negative by PJ-PCR. Of 18 PJ-PCR-positive samples, 11 (61.1%) tested positive and seven (38.9%) tested negative with the immunofluorescence assay (IFA). All (100%) of the 193 PJ-PCR-negative samples were IFA negative. Based on IFA/PCR results, patients were, respectively, classified as having (n = 18) and not having (n = 182) proven (PJ-PCR+/IFA+) or probable (PJ-PCR+/IFA−) PCP. For 182 patients without PCP, alternative infectious or non-infectious etiologies were identified. Our PJ-PCR assay was at least equivalent to IFA, fostering studies aimed at defining a qPCR-based standard for PCP diagnosis in the future.
Extraction, Structural Characterisation, and Immunomodulatory Properties of Edible Amanita hemibapha subspecies javanica (Corner and Bas) Mucilage Polysaccharide as a Potential of Functional Food
Authors: Surayot Utoomporn , Wangtueai Sutee , You SangGuan , Palanisamy Subramanian , Krusong Warawut , Brennan Charles S. , Barba Francisco J. , Phimolsiripol Yuthana , Seesuriyachan Phisit
Published: August 2021

This research aimed to extract mucilage polysaccharides (MP) from Amanita hemibapha subspecies javanica (Corner and Bas), and further fractionate them using anion-exchange chromatography, yielding two fractions (MPF1 and MPF2). The crude extract, and fractions mainly consisted of carbohydrates (83.5–93.2%) with minor amounts of proteins (5.40–7.20%), and sulphates (1.40–9.30%). Determination of the monosaccharide composition revealed that glucose was the major unit, followed by galactose, mannose, rhamnose, and arabinose. The average molecular weight (MW) of the crude extract and fractions was in the range 104.0–479.4 × 103 g/mol. Interestingly, the crude extract, and fractions did not cause any toxic effect in RAW264.7 cells. However, they stimulated the RAW264.7 cells to release nitric oxide and cytokines through the activation of nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) pathways via cell surface TLR4. Structural analysis of the most immunestimulating extract fraction, MPF2, revealed that the main backbone consisted of α-D-(1→6)-glucopyranoside. These results suggest that the MPs derived from A. hemibapha subspecies javanica (Corner and Bas) are potent in enhancing immunity; hence, they can be used as a functional ingredient in food products.
Government Subsidisation and Shareholder Wealth Impact: Evidence from Malaysia
Authors: Sinnadurai Philip , Subramaniam Ravichandran , Devi Susela , Ko Kyungyoung
Published: August 2021

This paper investigates the shareholder wealth impact of government investment in listed companies (and by extension, government subsidisation of those companies), using data from Malaysia. We distinguish two overlapping categories of government-related investors: those whose principal mission relates to economic policy and those whose principal mission relates to social policy. The methodology entails Ordinary Least Squares regressions. There are two dependent variables measuring management success at generating shareholder wealth: an intrinsic value surrogate and return on equity. The final sample comprises 1732 company–year observations from the investigation period 2011–2014. The evidence indicates that companies subject to shareholder by a government-related investor with a social (economic) policy mission are more (less) successful at generating wealth than companies without any government shareholding at all. The findings indicate that for companies subject to ownership by government investors with a mission related to economic policy, government subsidies are wealth-enhancing, subject to diminishing marginal returns beyond a threshold level of government shareholding. The research design reflects adaptations to the Malaysian institutional setting via choice of control variables and usage of data from a leading Malaysian equity analyst.
A Discount Technique-Based Inventory Management on Electronics Products Supply Chain
Authors: Miah Md. Sujan , Islam Md. Mominul , Hasan Mahmudul , Mashud Abu Hashan Md. , Roy Dipa , Sana Shib Sankar
Published: August 2021

Inventory management is becoming very challenging for the retailer over the years due to the uncertainty in the demand and supply of products in financial risk and management systems. In a competitive market, running a business smoothly in a highly suitable place is day by day becoming tough due to the very high fare for those locations. Thus, limited storage is available in those elite places with high fares, and a retailer takes a financial risk by stocking huge amounts of products in those limited storage stores. Thus, the appropriate financial analysis is required to find out optimal strategies (financial decisions) to sustain a business organization of electronic products in a global competitive business environment. As a result, when bulk purchases of electronic products, for example, T.V., Fridges, Oven, etc., have been made by the retailer, he faces two problems. The first one is related to the limited storage; as a result, he has to pay a considerable amount to hold the products for a long time. The second one is shortages of liquid money as he invested massive amounts. To avoid these problems, he offers some price discounts on the market’s original selling price to sell the products quickly for a limited time prior to recovering his capital investment. For that reason, a price, time, and stock dependent realistic demand function have been considered in this proposed paper with two modes of discount policy. The proposed model has been solved by a classical optimization technique from calculus and provides some insights for the retailer. Some numerical examples and graphs are provided to illustrate the model.
Bio-Ecological Features Update on Eleven Rare Cartilaginous Fish in the Central-Western Mediterranean Sea as a Contribution for Their Conservation
Authors: Mulas Antonello , Bellodi Andrea , Carbonara Pierluigi , Cau Alessandro , Marongiu Martina Francesca , Pesci Paola , Porcu Cristina , Follesa Maria Cristina
Published: August 2021

Cartilaginous fish are commonly recognized as key species in marine ecosystems for their fundamental ecological role as top predators. Nevertheless, effective management plans for cartilaginous fish are still missing, due to the lack of knowledge on their abundance, distribution or even life-history. In this regard, this paper aims at providing new information on the life-history traits, such as age, maturity, reproductive period, in addition to diet characteristics of eleven rare cartilaginous fish inhabiting the Central-Western Mediterranean Sea belonging to the orders Chimaeriformes (Chimaera monstrosa), Hexanchiformes (Heptranchias perlo and Hexanchus griseus), Myliobatiformes (Aetomylaeus bovinus and Myliobatis aquila), Rajiformes (Dipturus nidarosiensis and Leucoraja circularis), Squaliformes (Centrophorus uyato, Dalatias licha and Oxynotus centrina) and Torpediniformes (Tetronarce nobiliana), useful for their assessment and for future management actions. Particularly, the present paper provides for the first time the age estimation of D. nidarosienis and L. circularis which were both found capable of becoming older than ten years. In addition, the present study updates the sizes of first maturity of C. uyato and D. licha, which appeared to be capable of reproducing earlier than what was previously hypothesized, representing very valuable information for a better understanding of these rare species populations status and, eventually, their conservation. On the basis of the stomach content analysis, it was possible to identify five different predator groups.
The Way forward for the Origin of Life: Prions and Prion-Like Molecules First Hypothesis
Authors: Jheeta Sohan , Chatzitheodoridis Elias , Devine Kevin , Block Janice
Published: August 2021

In this paper the hypothesis that prions and prion-like molecules could have initiated the chemical evolutionary process which led to the eventual emergence of life is reappraised. The prions first hypothesis is a specific application of the protein-first hypothesis which asserts that protein-based chemical evolution preceded the evolution of genetic encoding processes. This genetics-first hypothesis asserts that an “RNA-world era” came before protein-based chemical evolution and rests on a singular premise that molecules such as RNA, acetyl-CoA, and NAD are relics of a long line of chemical evolutionary processes preceding the Last Universal Common Ancestor (LUCA). Nevertheless, we assert that prions and prion-like molecules may also be relics of chemical evolutionary processes preceding LUCA. To support this assertion is the observation that prions and prion-like molecules are involved in a plethora of activities in contemporary biology in both complex (eukaryotes) and primitive life forms. Furthermore, a literature survey reveals that small RNA virus genomes harbor information about prions (and amyloids). If, as has been presumed by proponents of the genetics-first hypotheses, small viruses were present during an RNA world era and were involved in some of the earliest evolutionary processes, this places prions and prion-like molecules potentially at the heart of the chemical evolutionary process whose eventual outcome was life. We deliberate on the case for prions and prion-like molecules as the frontier molecules at the dawn of evolution of living systems.
What Young E-Consumers Want? Forecasting Parcel Lockers Choice in Rome
Authors: Iannaccone Gabriele , Marcucci Edoardo , Gatta Valerio
Published: August 2021

Surges in e-commerce sales represent a huge challenge for urban freight transport. Parcel lockers constitute a valid solution for addressing the challenges home deliveries imply. In fact, eliminating courier–consumer contact (also relevant for health-related issues, as made evident by the COVID-19 pandemic) and delivering in fewer predefined places might help coping mechanisms for missed deliveries substantially. Furthermore, this option enables consolidated shipping and reduced delivery trip costs. This paper analyses and compares consumer preferences for alternative collection strategies. It investigates home delivery vs. parcel locker use and forecasts their future market shares. This is performed based on both customer socio-economic variables and the attributes characterising these alternative logistic fulfilment strategies. The case study considered tests upon a stated preference survey deployed in the city of Rome. The investigation specifically targeted young people (i.e., population under 30 years) since they represent early adopters. Discrete choice models allow both quantifying the monetary value of parcel lockers attributes (i.e., willingness to pay measures) and estimating the potential demand for this innovative delivery scheme. Results show that distance and accessibility are the main choice determinants. Furthermore, there is an overall high propensity to adopt parcel lockers. This research can support policymakers when implementing such solutions.
Transparency in Global Agribusiness: Transforming Brazil’s Soybean Supply Chain Based on Companies’ Accountability
Authors: Medina Gabriel , Thomé Karim
Published: August 2021

Background: Although agri-food supply chains have become fundamental for food security throughout the world, some are associated with negative environmental and socioeconomic impacts. This study explores the possibilities of transforming the governance in Brazil’s soybean supply chain based on stakeholders’ accountability. Methods: We used secondary data from companies’ reports and statistical yearbooks to identify key stakeholders in the soybean supply chain as well as to explore trade-offs between reducing farming expansion into new agricultural frontiers and increasing investments in agro-industrial sectors. Results: The results reveal that at the global level, multinational corporations along with domestic groups should be held accountable for improving the governance of the soybean supply chain in Brazil since foreign multinationals control 65.4% of it. At the domestic level, losses in Brazil’s farming sector can either be offset by an 11% or 5.2% market share increase in the trading segment or in the whole supply chain, respectively, since Brazilian groups control 93.4% of the farming sector but only 7.1% of the agro-industrial sectors. Conclusions: Global accountability and domestic trade-offs are fundamental for transforming governance in global agri-food supply chains. They serve as a means for overcoming the current strategy of expansion into new farming frontiers.
Polymer Nanocomposites with High Energy Density Utilizing Oriented Nanosheets and High-Dielectric-Constant Nanoparticles
Authors: Li Yushu , Zhou Yao , Cheng Sang , Hu Jun , He Jinliang , Li Qi
Published: August 2021

The development of high-energy-density electrostatic capacitors is critical to addressing the growing electricity need. Currently, the widely studied dielectric materials are polymer nanocomposites incorporated with high-dielectric-constant nanoparticles. However, the introduction of high-dielectric-constant nanoparticles can cause local electric field distortion and high leakage current, which limits the improvement in energy density. In this work, on the basis of conventional polymer nanocomposites containing high-dielectric-constant nanoparticles, oriented boron nitride nanosheets (BNNSs) are introduced as an extra filler phase. By changing the volume ratios of barium titanate (BT) and BNNSs, the dielectric property of polymer nanocomposites is adjusted, and thus the capacitive energy storage performance is optimized. Experimental results prove that the oriented BNNSs can suppress the propagation of charge carriers and decrease the conduction loss. Using poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) as the polymer matrix, the P(VDF-HFP)/BNNS/BT nanocomposite has a higher discharged energy density compared with the conventional nanocomposite with the freely dispersed BT nanoparticles.
Modified Grape Seeds: A Promising Alternative for Nitrate Removal from Water
Authors: Stjepanović Marija , Velić Natalija , Habuda-Stanić Mirna
Published: August 2021

The aim of this work was to investigate grape seeds as a potential adsorbent for nitrate removal from water. Grape seeds were modified by quaternization and the applicability of the modified grape seeds (MGS) was evaluated in batch adsorption experiments. Fixed bed adsorption and regeneration studies were carried out to determine the regeneration capacity of MGS. The maximum adsorption capacity of 25.626 mg g−1 at native pH (6.3) for nitrate removal by MSG was comparable to that of the commercial anion exchange resin Relite A490 under similar conditions. The percent removal of nitrate from model nitrate solution was 86.47% and 93.25% for MGS, and Relite A490, respectively, and in synthetic wastewater 57.54% and 78.37%. Analysis of the batch adsorption data using isotherm models revealed that the Freundlich model provided a better fit to the data obtained than the Langmuir model, indicating multilayer adsorption. In kinetic terms, the results showed that the adsorption followed the pseudo-first order model. By investigating the adsorption mechanism, the results suggest that the intraparticle diffusion model was not the only process controlling the adsorption of nitrate on MGS. In column experiments (adsorption/desorption studies), three adsorption cycles were tested with minimal decrease in adsorption capacities, implying that this alternative adsorbent can be successfully regenerated and reused.
Wetting and Spreading of AgCuTi on Selective Laser-Melted Ti-6Al-4V
Authors: Hao Lujing , Liu Jiankun , Li Yulong
Published: August 2021

Selective laser melting (SLM) can be used to manufacture complex parts, however, it is difficult to make large parts due to the size limitation of the SLM equipment. In application, smaller selective laser-melted (SLMed) Ti-6Al-4V (TC4) parts can be brazed or welded to form larger components. In the brazing, AgCuTi is often used to braze TC4. However, the wettability of AgCuTi on the SLMed TC4 should be evaluated before joining the SLMed TC4 parts. As a result, wetting and spreading tests and brazing experiments should be undertaken to successfully join the SLMed TC4 parts. In this study, a LINKAM TS 1500 high-temperature hot stage was used to test the brazability of the AgCuTi on the surface of SLMed TC4. Different temperatures and dwell times were used: (i) 850 °C 900 °C and 950 °C, holding for 120 s, were used to study the temperature effects; (ii) 20 s, 120 s and 200 s were used at 850 °C to study the dwell time effects. The R~t model was used to describe the wetting and spreading process. The results of this study can provide basic data for the joining of SLMed TC4 in industry.
Series Solutions of High-Dimensional Fractional Differential Equations
Authors: Chang Jing , Zhang Jin , Cai Ming
Published: August 2021

In the present paper, the series solutions and the approximate solutions of the time–space fractional differential equations are obtained using two different analytical methods. One is the homotopy perturbation Sumudu transform method (HPSTM), and another is the variational iteration Laplace transform method (VILTM). It is observed that the approximate solutions are very close to the exact solutions. The solutions obtained are very useful and significant to analyze many phenomena, and the solutions have not been reported in previous literature. The salient feature of this work is the graphical presentations of the third approximate solutions for different values of order α.
Wind Power Extraction Optimization by Dynamic Gain Scheduling Approximation Based on Non-Linear Functions for a WECS Based on a PMSG
Authors: González-Hernández José Genaro , Salas-Cabrera Rubén
Published: August 2021

Mathematical models and algorithms for maximizing power extraction have become an essential topic in renewable energies in the last years, especially in wind energy conversion systems. This study proposes maximum power point tracking using gain scheduling approximations for an emulated wind system in a direct-drive connection. Power extraction is obtained by controlling the duty cycle of a Multilevel Boost Converter, which directly varies the rotational speed of a permanent magnet synchronous generator directly coupled to a three-phase induction motor that emulates the wind turbine. The system’s complexity is linked to the inherent non-linearities associated with the diverse electrical, mechanical, and power electronic elements. In order to present a synthesized model without losing the system dynamic richness, several physical tests were made to obtain parameters for building several mathematical approaches, resulting in non-linear dynamic equations for the controller gains, which are dependant on wind speed. Thirty real operational wind speeds considering typical variations were used in several tests to demonstrate the mathematical models’ performance. Results among these gain scheduling approaches and a typical controller constant gains mathematical model were compared based on standard deviations, absolute error, and the time for reaching the optimum generator angular speed related to every wind speed.
Respondent Burden Effects on Item Non-Response and Careless Response Rates: An Analysis of Two Types of Surveys
Authors: Briz-Redón Álvaro
Published: August 2021

The respondent burden refers to the effort required by a respondent to answer a questionnaire. Although this concept was introduced decades ago, few studies have focused on the quantitative detection of such a burden. In this paper, a face-to-face survey and a telephone survey conducted in Valencia (Spain) are analyzed. The presence of burden is studied in terms of both item non-response rates and careless response rates. In particular, two moving-window statistics based on the coefficient of unalikeability and the average longstring index are proposed for characterizing careless responding. Item non-response and careless response rates are modeled for each survey by using mixed-effects models, including respondent-level and question-level covariates and also temporal random effects to assess the existence of respondent burden during the questionnaire. The results suggest that the sociodemographic characteristics of the respondents and the typology of the question impact item non-response and careless response rates. Moreover, the estimates of the temporal random effects indicate that item non-response and careless response rates are time-varying, suggesting the presence of respondent burden. In particular, an increasing trend in item non-response rates in the telephone survey has been found, which supports the hypothesis of the burden. Regarding careless responding, despite the presence of some temporal variation, no clear trend has been identified.
Association of Aortic Arch Calcification on Chest X-ray with Procedural Thromboembolism after Mechanical Thrombectomy for Acute Ischemic Stroke
Authors: Kim Hoon Gi , Lee Sang Hyuk , Nam Taek Min , Jang Ji Hwan , Kim Young Zoon , Kim Kyu Hong , Kim Do-Hyung , Kim Seung Hwan
Published: August 2021

Background and Objective: Procedural thromboembolism after a mechanical thrombectomy (MT) for an acute ischemic stroke (AIS) has rarely been studied. It may occur from the artery-to-artery embolization of atherosclerotic plaque in the aortic arch. We investigated the relationship between aortic arch calcification (AoAC) on a chest X-ray and procedural thromboembolism on diffusion-weighted imaging (DWI) after an MT. Materials and Methods: From January 2017 to December 2020, 131 patients underwent DWI within two days following an MT for an AIS. Procedural thromboembolism was defined as new DWI-positive lesions in other territories from the occluded artery on DWI within two days after MT. Results: Procedural thromboembolism was observed in 30 (22.9%) patients. Procedural thromboembolism was associated with old age (72.3 ± 9.44 vs. 65.7 ± 12.8 years, p = 0.003), a longer procedural time (77.6 ± 37.6 vs. 60.1 ± 29.7 min, p = 0.024), and AoAC (calcification (73.3%) vs. no calcification (29.7%), p < 0.001). Multivariable logistic regression analysis showed that procedural thromboembolism was independently associated with AoAC (adjusted odds ratio (OR): 6.107, adjusted 95% confidence interval (CI): 2.374–15.705, p < 0.001) and a longer procedural time (adjusted OR: 1.015, adjusted 95% CI: 1.001–1.030, p = 0.031). Conclusions: Procedural thromboembolism after an MT for an AIS was related to AoAC on a chest X-ray and a longer procedural time. Our results suggest that although rapid recanalization is the most crucial goal of an MT for an AIS, the importance of the careful advance of the guiding catheter through the aortic arch should not be underestimated to reduce the risk of procedural thromboembolism, especially in patients with AoAC on a chest X-ray.
Encapsulated Omental Necrosis as an Unexpected Postoperative Finding: A Case Report
Authors: Mitrovic Milica , Velickovic Dejan , Micev Marjan , Sljukic Vladimir , Djuric Petar , Tadic Boris , Skrobic Ognjan , Djokic Kovac Jelena
Published: August 2021

Postsurgical fat necrosis is a frequent finding in abdominal cross-sectional imaging. Epiploic appendagitis and omental infarction are a result of torsion or vascular occlusion. Surgery or pancreatitis are conditions that can have a traumatic and ischemic effect on fatty tissue. The imaging appearances may raise concerns for recurrent malignancy, but percutaneous biopsy and diagnostic follow-up assist in the accurate diagnosis of omental infarction. Herein we describe a case of encapsulated omental necrosis temporally related to gastric surgery. Preoperative CT and MRI findings showed the characteristics of encapsulated, postcontrast nonviable tumefaction in the epigastrium without clear imaging features of malignancy. Due to the size of the lesion and the patient’s primary disease, tumor recurrence could not be completely ruled out, and the patient underwent surgery. Histopathological analysis confirmed the diagnosis of steatonecrosis of the omentum.
Toxicological Profile of Umbilical Cord Blood-Derived Small Extracellular Vesicles
Authors: Rodrigues Silvia C. , Cardoso Renato M. S. , Gomes Claudia F. , Duarte Filipe V. , Freire Patricia C. , Neves Ricardo , Simoes-Correia Joana
Published: August 2021

The development and adoption of cell therapies has been largely limited by difficulties associated with their safety, handling, and storage. Extracellular vesicles (EV) have recently emerged as a likely mediator for the therapeutic effect of cells, offering several advantages over cell therapies. Due to their small size and inability to expand and metastasize, EV are generally considered safer than cell transplantation. Nevertheless, few studies have scrutinized the toxicity profile of EV, particularly after repeated high-dose administration. The present study aimed to evaluate a preparation of small EV obtained from umbilical cord blood mononuclear cells (UCB-MNC-sEV) for its cytotoxicity in different cell lines, as well as its differential accumulation, distribution, and toxicity following repeated intravenous (IV) administrations in a rodent model. In vitro, repeated sEV exposure in concentrations up to 1 × 1011 particles/mL had no deleterious impact on the viability or metabolic activity of peripheral blood mononuclear cells, THP-1 monocytes, THP-1-derived macrophages, normal dermal human fibroblasts, or human umbilical vein endothelial cells. DiR-labelled sEV, injected intravenously for four weeks in healthy rats, were detected in clearance organs, particularly the kidneys, spleen, and liver, similarly to control dye. Moreover, repeated administrations for six and twelve weeks of up to 1 × 1010 total particles of sEV dye were well-tolerated, with no changes in general haematological cell counts, or kidney and liver toxicity markers. More importantly, unlabelled sEV likewise did not induce significant alterations in cellular and biochemical blood parameters, nor any morphological changes in the heart, kidney, lung, spleen, or liver tissue. In sum, our data show that UCB-MNC-sEV have no significant toxicity in vitro or in vivo, even when administered repeatedly at high concentrations, therefore confirming their safety profile and potential suitability for future clinical use.
Zingiber cassumunar Roxb. Essential Oil-Loaded Electrospun Poly(lactic acid)/Poly(ethylene oxide) Fiber Blend Membrane for Antibacterial Wound Dressing Application
Authors: Sinsup Pattawika , Teeranachaideekul Veerawat , Makarasen Arthit , Chuenchom Laemthong , Prajongtat Pongthep , Techasakul Supanna , Yingyuad Peerada , Dechtrirat Decha
Published: August 2021

The essential oil from Zingiber cassumunar Roxb. (Plai) has long been used in Thai herbal remedies to treat inflammation, pains, sprains, and wounds. It was therefore loaded into an electrospun fibrous membrane for use as an analgesic and antibacterial dressing for wound care. The polymer blend between poly(lactic acid) and poly(ethylene oxide) was selected as the material of choice because its wettability can be easily tuned by changing the blend ratio. Increasing the hydrophilicity and water uptake ability of the material while retaining its structural integrity and porosity provides moisture balance and removes excess exudates, thereby promoting wound healing. The effect of the blend ratio on the fiber morphology and wettability was investigated using scanning electron microscopy (SEM) and contact angle measurement, respectively. The structural determination of the prepared membranes was conducted using Fourier-transform infrared spectroscopy (FTIR). The release behavior of (E)-1-(3,4-dimethoxyphenyl) butadiene (DMPBD), a marker molecule with potent anti-inflammatory activity from the fiber blend, showed a controlled release characteristic. The essential oil-loaded electrospun membrane also showed antibacterial activity against S. aureus and E. coli. It also exhibited no toxicity to both human fibroblast and keratinocyte cells, suggesting that the prepared material is suitable for wound dressing application.
Fouling Behavior in a High-Rate Anaerobic Submerged Membrane Bioreactor (AnMBR) for Palm Oil Mill Effluent (POME) Treatment
Authors: Chaipetch Wiparat , Jaiyu Arisa , Jutaporn Panitan , Heran Marc , Khongnakorn Watsa
Published: August 2021

The characteristics of foulant in the cake layer and bulk suspended solids of a 10 L submerged anaerobic membrane bioreactor (AnMBR) used for treatment of palm oil mill effluent (POME) were investigated in this study. Three different organic loading rates (OLRs) were applied with prolonged sludge retention time throughout a long operation time (270 days). The organic foulant was characterized by biomass concentration and concentration of extracellular polymeric substances (EPS). The thicknesses of the cake layer and foulant were analyzed by confocal laser scanning microscopy and Fourier transform infrared spectroscopy. The membrane morphology and inorganic elements were analyzed by field emission scanning electron microscope coupled with energy dispersive X-ray spectrometer. Roughness of membrane was analyzed by atomic force microscopy. The results showed that the formation and accumulation of protein EPS in the cake layer was the key contributor to most of the fouling. The transmembrane pressure evolution showed that attachment, adsorption, and entrapment of protein EPS occurred in the membrane pores. In addition, the hydrophilic charge of proteins and polysaccharides influenced the adsorption mechanism. The composition of the feed (including hydroxyl group and fatty acid compounds) and microbial metabolic products (protein) significantly affected membrane fouling in the high-rate operation.
Ab Initio Quantum-Mechanical Predictions of Semiconducting Photocathode Materials
Authors: Cocchi Caterina , Saßnick Holger-Dietrich
Published: August 2021

Ab initio Quantum-Mechanical methods are well-established tools for material characterization and discovery in many technological areas. Recently, state-of-the-art approaches based on density-functional theory and many-body perturbation theory were successfully applied to semiconducting alkali antimonides and tellurides, which are currently employed as photocathodes in particle accelerator facilities. The results of these studies have unveiled the potential of ab initio methods to complement experimental and technical efforts for the development of new, more efficient materials for vacuum electron sources. Concomitantly, these findings have revealed the need for theory to go beyond the status quo in order to face the challenges of modeling such complex systems and their properties in operando conditions. In this review, we summarize recent progress in the application of ab initio many-body methods to investigate photocathode materials, analyzing the merits and the limitations of the standard approaches with respect to the confronted scientific questions. In particular, we emphasize the necessary trade-off between computational accuracy and feasibility that is intrinsic to these studies, and propose possible routes to optimize it. We finally discuss novel schemes for computationally-aided material discovery that are suitable for the development of ultra-bright electron sources toward the incoming era of artificial intelligence.
Progress in Non-Traditional Processing for Fabricating Superhydrophobic Surfaces
Authors: Shen Dili , Ming Wuyi , Ren Xinggui , Xie Zhuobin , Liu Xuewen
Published: August 2021

When the water droplets are on some superhydrophobic surfaces, the surface only needs to be inclined at a very small angle to make the water droplets roll off. Hence, building a superhydrophobic surface on the material substrate, especially the metal substrate, can effectively alleviate the problems of its inability to resist corrosion and easy icing during use, and it can also give it special functions such as self-cleaning, lubrication, and drag reduction. Therefore, this study reviews and summarizes the development trends in the fabrication of superhydrophobic surface materials by non-traditional processing techniques. First, the principle of the superhydrophobic surfaces fabricated by laser beam machining (LBM) is introduced, and the machining performances of the LBM process, such as femtosecond laser, picosecond laser, and nanosecond laser, for fabricating the surfaces are compared and summarized. Second, the principle and the machining performances of the electrical discharge machining (EDM), for fabricating the superhydrophobic surfaces, are reviewed and compared, respectively. Third, the machining performances to fabricate the superhydrophobic surfaces by the electrochemical machining (ECM), including electrochemical oxidation process and electrochemical reduction process, are reviewed and grouped by materials fabricated. Lastly, other non-traditional machining processes for fabricating superhydrophobic surfaces, such as ultrasonic machining (USM), water jet machining (WJM), and plasma spraying machining (PSM), are compared and summarized. Moreover, the advantage and disadvantage of the above mentioned non-traditional machining processes are discussed. Thereafter, the prospect of non-traditional machining for fabricating the desired superhydrophobic surfaces is proposed.
Entropy Production in Electroosmotic Cilia Facilitated Stream of Thermally Radiated Nanofluid with Ohmic Heating
Authors: Saleem Najma , Munawar Sufian , Mehmood Ahmer , Daqqa Ibtisam
Published: August 2021

No thermal process, even the biological systems, can escape from the long arms of the second law. All living things preserve entropy since they obtain energy from the nutrition they consume and gain order by producing disorder. The entropy generation in a biological and thermally isolated system is the main subject of current investigation. The aim is to examine the entropy generation during the convective transport of a ciliated nano-liquid in a micro-channel under the effect of a uniform magnetic field. Joint effects of electroosmosis and thermal radiation are also brought into consideration. To attain mathematical simplicity, the governing equations are transformed to wave frame where the inertial parts of the transport equations are dropped with the use of a long-wavelength approximation. This finally produces the governing equations in the form of ordinary differential equations which are solved numerically by a shooting technique. The analysis reports that the cilia motion contributes to enhance the flow and heat transfer phenomena. An enhancement in the flow is observed near the channel surface for higher cilia length and for smaller values of the electroosmotic parameter. The entropy generation in the ciliated channel is observed to be lessened by intensifying the thermal radiation and decreasing the Ohmic heating. The extended and flexible cilia structure contributes to augment the volumetric flow rate and to drop the total entropy generation in the channel.
Fabrication of 3D Micro-Blades for the Cutting of Biological Structures in a Microfluidic Guillotine
Authors: Koppaka Saisneha , Zhang Kevin , Kurosu Jalil Myra , Blauch Lucas , Tang Sindy
Published: August 2021

Micro-blade design is an important factor in the cutting of single cells and other biological structures. This paper describes the fabrication process of three-dimensional (3D) micro-blades for the cutting of single cells in a microfluidic “guillotine” intended for fundamental wound repair and regeneration studies. Our microfluidic guillotine consists of a fixed 3D micro-blade centered in a microchannel to bisect cells flowing through. We show that the Nanoscribe two-photon polymerization direct laser writing system is capable of fabricating complex 3D micro-blade geometries. However, structures made of the Nanoscribe IP-S resin have low adhesion to silicon, and they tend to peel off from the substrate after at most two times of replica molding in poly(dimethylsiloxane) (PDMS). Our work demonstrates that the use of a secondary mold replicates Nanoscribe-printed features faithfully for at least 10 iterations. Finally, we show that complex micro-blade features can generate different degrees of cell wounding and cell survival rates compared with simple blades possessing a vertical cutting edge fabricated with conventional 2.5D photolithography. Our work lays the foundation for future applications in single cell analyses, wound repair and regeneration studies, as well as investigations of the physics of cutting and the interaction between the micro-blade and biological structures.
Fabrication of Needle-Like Silicon Nanowires by Using a Nanoparticles-Assisted Bosch Process for Both High Hydrophobicity and Anti-Reflection
Authors: Zhang Zengxing , Liu Guohua , Wang Kaiying
Published: August 2021

In this work, a modified Bosch etching process is developed to create silicon nanowires. Au nanoparticles (NPs) formed by magnetron sputtering film deposition and thermal annealing were employed as the hard mask to achieve controllable density and high aspect ratios. Such silicon nanowire exhibits the excellent anti-reflection ability of a reflectance value of below 2% within a broad light wave range between 220 and 1100 nm. In addition, Au NPs-induced surface plasmons significantly enhance the near-unity anti-reflection characteristics, achieving a reflectance below 3% within the wavelength range of 220 to 2600 nm. Furthermore, the nanowire array exhibits super-hydrophobic behavior with a contact angle over ~165.6° without enforcing any hydrophobic chemical treatment. Such behavior yields in water droplets bouncing off the surface many times. These properties render this silicon nanowire attractive for applications such as photothermal, photocatalysis, supercapacitor, and microfluidics.
Current Applications of Absolute Bacterial Quantification in Microbiome Studies and Decision-Making Regarding Different Biological Questions
Authors: Wang Xiaofan , Howe Samantha , Deng Feilong , Zhao Jiangchao
Published: August 2021

High throughput sequencing has emerged as one of the most important techniques for characterizing microbial dynamics and revealing bacteria and host interactions. However, data interpretation using this technique is mainly based on relative abundance and ignores total bacteria load. In certain cases, absolute abundance is more important than compositional relative data, and interpretation of microbiota data based solely on relative abundance can be misleading. The available approaches for absolute quantification are highly diverse and challenging, especially for quantification in differing biological situations, such as distinguishing between live and dead cells, quantification of specific taxa, enumeration of low biomass samples, large sample size feasibility, and the detection of various other cellular features. In this review, we first illustrate the importance of integrating absolute abundance into microbiome data interpretation. Second, we briefly discuss the most widely used cell-based and molecular-based bacterial load quantification methods, including fluorescence spectroscopy, flow cytometry, 16S qPCR, 16S qRT-PCR, ddPCR, and reference spike-in. Last, we present a specific decision-making scheme for absolute quantification methods based on different biological questions and some of the latest quantitative methods and procedure modifications.
Epigenetic Response of Yarrowia lipolytica to Stress: Tracking Methylation Level and Search for Methylation Patterns via Whole-Genome Sequencing
Authors: Kubiak-Szymendera Monika , Pryszcz Leszek P. , Białas Wojciech , Celińska Ewelina
Published: August 2021

DNA methylation is a common, but not universal, epigenetic modification that plays an important role in multiple cellular processes. While definitely settled for numerous plant, mammalian, and bacterial species, the genome methylation in different fungal species, including widely studied and industrially-relevant yeast species, Yarrowia lipolytica, is still a matter of debate. In this paper, we report a differential DNA methylation level in the genome of Y. lipolytica subjected to sequential subculturing and to heat stress conditions. To this end, we adopted repeated batch bioreactor cultivations of Y. lipolytica subjected to thermal stress in specific time intervals. To analyze the variation in DNA methylation between stressed and control cultures, we (a) quantified the global DNA methylation status using an immuno-assay, and (b) studied DNA methylation patterns through whole-genome sequencing. Primarily, we demonstrated that 5 mC modification can be detected using a commercial immuno-assay, and that the modifications are present in Y. lipolytica’s genome at ~0.5% 5 mC frequency. On the other hand, we did not observe any changes in the epigenetic response of Y. lipolytica to heat shock (HS) treatment. Interestingly, we identified a general phenomenon of decreased 5 mC level in Y. lipolytica’s genome in the stationary phase of growth, when compared to a late-exponential epigenome. While this study provides an insight into the subculturing stress response and adaptation to the stress at epigenetic level by Y. lipolytica, it also leaves an open question of inability to detect any genomic DNA methylation level (either in CpG context or context-less) through whole-genome sequencing. The results of ONT sequencing, suggesting that 5 mC modification is either rare or non-existent in Y. lipolytica genome, are contradicted with the results of the immunoassay.
Genome Analysis of Streptomyces nojiriensis JCM 3382 and Distribution of Gene Clusters for Three Antibiotics and an Azasugar across the Genus Streptomyces
Authors: Park Jin-Soo , Kim Da-Eun , Hong Sung-Chul , Kim Seung-Young , Kwon Hak Cheol , Hyun Chang-Gu , Choi Jaeyoung
Published: August 2021

Streptomyces spp. have been major contributors of novel natural products that are used in many application areas. We found that the nojirimycin (NJ) producer JCM 3382 has antimicrobial activity against Staphylococcus aureus via cellular degradation. Genome analysis revealed 30 biosynthetic gene clusters, including those responsible for producing antibiotics, including an azasugar NJ. In-depth MS/MS analysis confirmed the production of 1-deoxynojirimycin (DNJ) along with NJ. In addition, the production of tambromycins, setomimycin, and linearmycins was verified by spectroscopic analyses, including LC-MS and NMR. The distribution of the clusters of genes coding for antibiotics in 2061 Streptomyces genomes suggested potential producers of tambromycin, setomimycin, and linearmycin. For a DNJ gene cluster, homologs of gabT1 and gutB1 were commonly found; however, yktC1 was identified in only 112 genomes. The presence of several types of clusters suggests that different strains may produce different types of azasugars. Chemical-profile-inspired comparative genome analysis may facilitate a more accurate assessment of the biosynthetic potential to produce secondary metabolites.
Phytate and Microbial Suspension Amendments Increased Soybean Growth and Shifted Microbial Community Structure
Authors: Ahmed Bulbul , Floc’h Jean-Baptiste , Lahrach Zakaria , Hijri Mohamed
Published: August 2021

Phytate represents an organic pool of phosphorus in soil that requires hydrolysis by phytase enzymes produced by microorganisms prior to its bioavailability by plants. We tested the ability of a microbial suspension made from an old growth maple forest’s undisturbed soil to mineralize phytate in a greenhouse trial on soybean plants inoculated or non-inoculated with the suspension. MiSeq Amplicon sequencing targeting bacterial 16S rRNA gene and fungal ITS was performed to assess microbial community changes following treatments. Our results showed that soybean nodulation and shoot dry weight biomass increased when phytate was applied to the nutrient-poor substrate mixture. Bacterial and fungal diversities of the root and rhizosphere biotopes were relatively resilient following inoculation by microbial suspension; however, bacterial community structure was significantly influenced. Interestingly, four arbuscular mycorrhizal fungi (AMF) were identified as indicator species, including Glomus sp., Claroideoglomus etunicatum, Funneliformis mosseae and an unidentified AMF taxon. We also observed that an ericoid mycorrhizal taxon Sebacina sp. and three Trichoderma spp. were among indicator species. Non-pathogenic Planctobacteria members highly dominated the bacterial community as core and hub taxa for over 80% of all bacterial datasets in root and rhizosphere biotopes. Overall, our study documented that inoculation with a microbial suspension and phytate amendment improved soybean plant growth.