bluuebunny/crossref_metadata_2025 huggingface dataset:
Mono or Dual Antiplatelet Therapy for Treating Patients with Peripheral Artery Disease after Lower Extremity Revascularization: A Systematic Review and Meta-Analysis
Authors: Tsai Shang-Yu , Li Ying-Sheng , Lee Che-Hsiung , Cha Shion-Wei , Wang Yao-Chang , Su Ta-Wei , Yu Sheng-Yueh , Yeh Chi-Hsiao
Published: May 2022

The efficacy of dual antiplatelet therapy (DAPT) for patients with peripheral artery disease (PAD) after lower-limb intervention remains controversial. Currently, the prescription of DAPT after an intervention is not fully recommended in guidelines due to limited evidence. This study compares and analyzes the prognosis for symptomatic PAD patients receiving DAPT versus monotherapy after lower-limb revascularization. Up to November 2021, PubMed/MEDLINE, Embase, and Cochrane databases were searched to identify studies reporting the efficacy, duration, and bleeding complications when either DAPT or monotherapy were used to treat PAD patients after revascularization. Three randomized controlled trials and seven nonrandomized controlled trials were included in our study. In total, 74,651 patients made up these ten studies. DAPT in PAD patients after intervention was associated with lower rates of all-cause mortality (HR = 0.86; 95% CI, 0.79–0.94; p < 0.01), major adverse limb events (HR = 0.60; 95% CI, 0.47–0.78; p < 0.01), and major amputation (HR = 0.78; 95% CI, 0.64–0.96) when follow-up was for more than 1-year. DAPT was not associated with major bleeding events when compared with monotherapy (OR = 1.22; 95% CI, 0.69–2.18; p = 0.50) but was associated with a higher rate of minor bleeding as a complication (OR = 2.54; 95% CI, 1.59–4.08; p < 0.01). More prospective randomized studies are needed to provide further solid evidence regarding the important issue of prescribing DAPT.
Phytopigment Alizarin Inhibits Multispecies Biofilm Development by Cutibacterium acnes, Staphylococcus aureus, and Candida albicans
Authors: Lee Jin-Hyung , Kim Yong-Guy , Park Sunyoung , Hu Liangbin , Lee Jintae
Published: May 2022

Acne vulgaris is a common chronic inflammatory skin disease involving Cutibacterium acnes with other skin commensals such as Staphylococcus aureus and Candida albicans in the anaerobic and lipid-rich conditions of pilosebaceous units. These microbes readily form multispecies biofilms that are tolerant of traditional antibiotics as well as host immune systems. The phytopigment alizarin was previously found to prevent biofilm formation by S. aureus and C. albicans strains under aerobic conditions. Hence, we hypothesized that alizarin might control C. acnes and multispecies biofilm development. We found that under anaerobic conditions, alizarin efficiently inhibited single biofilm formation and multispecies biofilm development by C. acnes, S. aureus, and C. albicans without inhibiting planktonic cell growth. Alizarin increased the hydrophilicities of S. aureus and C. albicans cells, decreased lipase production by S. aureus, diminished agglutination by C. acnes, and inhibited the aggregation of C. albicans cells. Furthermore, the co-administration of alizarin and antibiotics enhanced the antibiofilm efficacies of alizarin against C. acnes. A transcriptomic study showed that alizarin repressed the transcriptions of various biofilm-related genes such as lipase, hyaluronate lyase, adhesin/invasion-related, and virulence-related genes of C. acnes. Furthermore, alizarin at 100 µg/mL prevented C. acnes biofilm development on porcine skin. Our results show that alizarin inhibits multispecies biofilm development by acne-causing microbes and suggest it might be a useful agent for treating or preventing C. acnes-causing skin diseases.
Current Approaches to Monitor Macromolecules Directly from the Cerebral Interstitial Fluid
Authors: Custers Marie-Laure , Nestor Liam , De Bundel Dimitri , Van Eeckhaut Ann , Smolders Ilse
Published: May 2022

Gaining insights into the pharmacokinetic and pharmacodynamic properties of lead compounds is crucial during drug development processes. When it comes to the treatment of brain diseases, collecting information at the site of action is challenging. There are only a few techniques available that allow for the direct sampling from the cerebral interstitial space. This review concerns the applicability of microdialysis and other approaches, such as cerebral open flow microperfusion and electrochemical biosensors, to monitor macromolecules (neuropeptides, proteins, …) in the brain. Microdialysis and cerebral open flow microperfusion can also be used to locally apply molecules at the same time at the site of sampling. Innovations in the field are discussed, together with the pitfalls. Moreover, the ‘nuts and bolts’ of the techniques and the current research gaps are addressed. The implementation of these techniques could help to improve drug development of brain-targeted drugs.
Complex Scenarios of Reticulation, Polyploidization, and Species Diversity within Annual Pansies of Subsect. Bracteolatae (Viola Sect. Melanium, Violaceae) in Italy: Insights from 5S-IGS High-Throughput Sequencing and Plastid DNA Variation
Authors: Scoppola Anna , Cardoni Simone , Marcussen Thomas , Simeone Marco Cosimo
Published: May 2022

Viola sect. Melanium, the so-called pansy, is an allopolyploid morphologically well-defined lineage of ca. 110 perennial and annual species in the northern hemisphere, characterized by markedly complex genomic configurations. Five annual pansies occur in Italy, four of which are morphologically very similar and belong to the informal ‘V. tricolor species complex’: V. arvensis (2n = 34), V. hymettia (2n = 16), V. kitaibeliana (2n = 16), and V. tricolor (2n = 26). Their field recognition is difficult and reflects a long-debated taxonomy often resulting in doubtful records in field inventories and across European herbaria. The current lack of comprehensive intra- and interspecific comparative studies and a relative scarcity of appropriate genetic markers coupled with unambiguous cytological descriptions are hindering clear taxa circumscription and phylogenetic inferences within this group. In this work, we tested DNA sequence variation of three highly variable plastid markers and High-Throughput Sequencing (HTS) of the nuclear ribosomal 5S-IGS region in an attempt to decipher species identity within the V. tricolor species complex and to obtain an insight on their genome organization and evolution. Our results document the close relationships within this species group, a reliable molecular resolution for V. tricolor, and the common ancestry of V. arvensis and the poorly differentiated V. kitaibeliana and V. hymettia. Evidence of an important inter-population geographical divergence was recorded in V. tricolor and V. arvensis, pointing at the existence of different eco-cytotypes within these entities. Overall diversity patterns and the occurrence of two to four differently diverging 5S-IGS lineages are discussed in the light of the acknowledged taxonomy and genomic evolutive trajectories of sect. Melanium.
Green Revolution to Gene Revolution: Technological Advances in Agriculture to Feed the World
Authors: Hamdan Mohd Fadhli , Mohd Noor Siti Nurfadhlina , Abd-Aziz Nazrin , Pua Teen-Lee , Tan Boon Chin
Published: May 2022

Technological applications in agriculture have evolved substantially to increase crop yields and quality to meet global food demand. Conventional techniques, such as seed saving, selective breeding, and mutation breeding (variation breeding), have dramatically increased crop production, especially during the ‘Green Revolution’ in the 1990s. However, newer issues, such as limited arable lands, climate change, and ever-increasing food demand, pose challenges to agricultural production and threaten food security. In the following ‘Gene Revolution’ era, rapid innovations in the biotechnology field provide alternative strategies to further improve crop yield, quality, and resilience towards biotic and abiotic stresses. These innovations include the introduction of DNA recombinant technology and applications of genome editing techniques, such as transcription activator-like effector (TALEN), zinc-finger nucleases (ZFN), and clustered regularly interspaced short palindromic repeats/CRISPR associated (CRISPR/Cas) systems. However, the acceptance and future of these modern tools rely on the regulatory frameworks governing their development and production in various countries. Herein, we examine the evolution of technological applications in agriculture, focusing on the motivations for their introduction, technical challenges, possible benefits and concerns, and regulatory frameworks governing genetically engineered product development and production.
Calcium-Rich Biochar Stimulates Salt Resistance in Pearl Millet (Pennisetum glaucum L.) Plants by Improving Soil Quality and Enhancing the Antioxidant Defense
Authors: Abo-Elyousr Kamal A. M. , Mousa Magdi A. A. , Ibrahim Omer H. M. , Alshareef Nouf Owdah , Eissa Mamdouh A.
Published: May 2022

Shrimp waste is rich in organic compounds and essential plant nutrients, e.g., calcium (Ca), and converting these wastes to organic fertilizer is important for environmental preservation and to achieve sustainable agricultural management. In the current study, Ca-rich biochar was prepared from shrimp wastes (SWB) by pyrolysis at 300 °C. We hypothesized that the Ca-rich biochar will help in solving the problem of plant growth in saline soil by reducing sodium (Na) uptake and mitigating oxidative stress. The current study aimed to investigate the effect of SWB on the quality of saline sandy soil and the mechanism of salt resistance in pearl millet (Pennisetum glaucum L.). Pearl millet plants were planted in saline sandy soil (10 dS m−1) in wooden boxes (1.3 × 0.8 m size and 0.4 m height), and 5 doses (0, 1.0, 1.5, 2.0, and 2.5% (w/w)) of SWB were added. SWB application increased the soil quality and nutrient uptake by pearl millet plants. The highest rate of SWB increased the soil microbial biomass carbon and the activity of dehydrogenase enzyme by 43 and 47% compared to the control soil. SWB application reduced the uptake of sodium (Na+) and chloride (Cl−) and increased the K/Na ratio in the leaf tissues. SWB addition significantly increased the activity of antioxidant enzymes, e.g., ascorbate peroxidase (APX), polyphenol oxidase (PPO), and pyrogallol peroxidases (PPX). The application of 2.5% SWB to the saline soil increased the soluble carbohydrates and proline in plant leaves by 75 and 60%, respectively, and reduced the malondialdehyde (MDA) by 32% compared to the control. SWB enhanced the antioxidant defense and mitigated oxidative stress by improving the synthesis of osmoprotectants, e.g., soluble carbohydrates and proline. Sandy saline soils in arid and semiarid areas suffer greatly from low organic matter contents, which reduces the soil quality and increases the risk of salt during plant growth. The high organic matter and calcium content (30%) in the shrimp waste-derived biochar improved the quality of the saline sandy soil, reduced the uptake of toxic salts, and increased the quality of the forage material. The addition of recycled shrimp waste to saline low-fertility soils improves soil productivity and is safe for soil health.
Polymers in High-Efficiency Solar Cells: The Latest Reports
Authors: Gnida Paweł , Amin Muhammad Faisal , Pająk Agnieszka Katarzyna , Jarząbek Bożena
Published: May 2022

Third-generation solar cells, including dye-sensitized solar cells, bulk-heterojunction solar cells, and perovskite solar cells, are being intensively researched to obtain high efficiencies in converting solar energy into electricity. However, it is also important to note their stability over time and the devices’ thermal or operating temperature range. Today’s widely used polymeric materials are also used at various stages of the preparation of the complete device—it is worth mentioning that in dye-sensitized solar cells, suitable polymers can be used as flexible substrates counter-electrodes, gel electrolytes, and even dyes. In the case of bulk-heterojunction solar cells, they are used primarily as donor materials; however, there are reports in the literature of their use as acceptors. In perovskite devices, they are used as additives to improve the morphology of the perovskite, mainly as hole transport materials and also as additives to electron transport layers. Polymers, thanks to their numerous advantages, such as the possibility of practically any modification of their chemical structure and thus their physical and chemical properties, are increasingly used in devices that convert solar radiation into electrical energy, which is presented in this paper.
Influence of Multiple Thermomechanical Processing of 3D Filaments Based on Polylactic Acid and Polyhydroxybutyrate on Their Rheological and Utility Properties
Authors: Plavec Roderik , Horváth Vojtech , Hlaváčiková Slávka , Omaníková Leona , Repiská Martina , Medlenová Elena , Feranc Jozef , Kruželák Ján , Přikryl Radek , Figalla Silvestr , Kontárová Soňa , Baco Andrej , Danišová Lucia , Vanovčanová Zuzana , Alexy Pavol
Published: May 2022

This study focused on material recycling of a biodegradable blend based on PLA and PHB for multiple applications of biodegradable polymeric material under real conditions. In this study, we investigated the effect of multiple processing of a biodegradable polymer blend under the trade name NONOILEN®, which was processed under laboratory as well as industrial conditions. In this article, we report on testing the effect of blending and multiple processing on thermomechanical stability, molecular characteristics, as well as thermophysical and mechanical properties of experimental- and industrial-type tested material suitable for FDM 3D technology. The results showed that the studied material degraded during blending and subsequently during multiple processing. Even after partial degradation, which was demonstrated by a decrease in average molecular weight and a decrease in complex viscosity in the process of multiple reprocessing, there was no significant change in the material’s thermophysical properties, either in laboratory or industrial conditions. There was also no negative impact on the strength characteristics of multiple processed samples. The results of this work show that a biodegradable polymer blend based on PLA and PHB is a suitable candidate for material recycling even in industrial processing conditions. In addition, the results suggest that the biodegradable polymeric material NONOILEN® 3D 3056-2 is suitable for multiple uses in FDM technology.
Incorporation of Mycobacteriophage Fulbright into Polycaprolactone Electrospun Nanofiber Wound Dressing
Authors: Kotturi Hari , Lopez-Davis Charmaine , Nikfarjam Sadegh , Kedy Cameron , Byrne Micah , Barot Vishal , Khandaker Morshed
Published: May 2022

The Genus Mycobacterium includes pathogens known to cause disease in mammals such as tuberculosis (Mycobacterium tuberculosis) and skin infections (M. abscessus). M. smegmatis is a model bacterium that can cause opportunistic infections in human tissues and, rarely, a respiratory disease. Due to the emergence of multidrug-resistant bacteria, phage therapy is potentially an alternative way of treating these bacterial infections. As bacteriophages are specific to their bacterial host, it ensures that the normal flora is unharmed. Fulbright is a mycobacteriophage that infects the host bacteria M. smegmatis. The main goal of this study is to incorporate Mycobacteriophage Fulbright into a polycaprolactone (PCL) nanofiber and test its antimicrobial effect against the host bacteria, M. smegmatis. Stability tests conducted over 7 days showed that the phage titer does not decrease when in contact with PCL, making it a promising vehicle for phage delivery. Antimicrobial assays showed that PCL_Fulbright effectively reduces bacterial concentration after 24 h of contact. In addition, when stored at −20 °C, the phage remains viable for up to eleven months in the fiber. Fulbright addition on the nanofibrous mats resulted in an increase in water uptake and decrease in the mechanical properties (strength and Young’s modulus) of the membranes, indicating that the presence of phage Fulbright can greatly enhance the physical and mechanical properties of the PCL. Cytotoxicity assays showed that PCL_Fulbright is not cytotoxic to Balbc/3T3 mouse embryo fibroblast cell lines; thus, phage-incorporated PCL is a promising alternative to antibiotics in treating skin infections.
pH-Responsive PVA/BC-f-GO Dressing Materials for Burn and Chronic Wound Healing with Curcumin Release Kinetics
Authors: Al-Arjan Wafa Shamsan , Khan Muhammad Umar Aslam , Almutairi Hayfa Habes , Alharbi Shadia Mohammed , Razak Saiful Izwan Abd
Published: May 2022

Polymeric materials have been essential biomaterials to develop hydrogels as wound dressings for sustained drug delivery and chronic wound healing. The microenvironment for wound healing is created by biocompatibility, bioactivity, and physicochemical behavior. Moreover, a bacterial infection often causes the healing process. The bacterial cellulose (BC) was functionalized using graphene oxide (GO) by hydrothermal method to have bacterial cellulose-functionalized-Graphene oxide (BC-f-GO). A simple blending method was used to crosslink BC-f-GO with polyvinyl alcohol (PVA) by tetraethyl orthosilicate (TEOS) as a crosslinker. The structural, morphological, wetting, and mechanical tests were conducted using Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), water contact angle, and a Universal testing machine (UTM). The release of Silver-sulphadiazine and drug release kinetics were studied at various pH levels and using different mathematical models (zero-order, first-order, Higuchi, Hixson, Korsmeyer–Peppas, and Baker–Lonsdale). The antibacterial properties were conducted against Gram-positive and Gram-negative severe infection-causing pathogens. These composite hydrogels presented potential anticancer activities against the U87 cell line by an increased GO amount. The result findings show that these composite hydrogels have physical-mechanical and inherent antimicrobial properties and controlled drug release, making them an ideal approach for skin wound healing. As a result, these hydrogels were discovered to be an ideal biomaterial for skin wound healing.
Incorporation of Poly(Ionic Liquid) with PVDF-HFP-Based Polymer Electrolyte for All-Solid-State Lithium-Ion Batteries
Authors: Ruan Zhefei , Du Yuzhe , Pan Hongfei , Zhang Ruiming , Zhang Fangfang , Tang Haolin , Zhang Haining
Published: May 2022

A solid-state polymer electrolyte membrane is formed by blending poly(vinylidene fluoride-co-hexafluoropropylene) with the synthesized copolymer of poly(methyl methacrylate-co-1-vinyl-3-butyl-imidazolium bis(trifluoromethanesulfonyl)imide, in which lithium bis(trifluoromethane)sulfonimide molecules are applied as the source of lithium ions. The accordingly formed membrane that contains 14 wt.% of P(MMA-co-VBIm-TFSI), 56 wt.% of PVDF-HFP, and 30 wt.% of LiTFSI manifests the best electrochemical properties, achieving an ionic conductivity of 1.11 × 10−4 S·cm−1 at 30 °C and 4.26 × 10−4 S·cm−1 at 80 °C, a Li-ion transference number of 0.36, and a wide electrochemical stability window of 4.7 V (vs. Li/Li+). The thus-assembled all-solid-state lithium-ion battery of LiFePO4/SPE/Li delivers a discharge specific capacity of 148 mAh·g−1 in the initial charge–discharge cycle at 0.1 C under 60 °C. The capacity retention of the cell is 95.2% after 50 cycles at 0.1 C and the Coulombic efficiency remains close to 100% during the cycling process.
Research on Impact Resistance of Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer Grid and Engineered Cementitious Composites
Authors: Si Zhihao , Liu Fan , Pan Jianwu , Dong Hao
Published: May 2022

When reinforced concrete structures are subjected to impact loads, they may suddenly yield or fail, or even collapse as a whole. In this paper, the impact resistance of reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymer (CFRP) grid and engineered cementitious composites (ECC) was studied. Drop hammer impact tests were conducted on eight beams, then the finite element model was used to simulate the impact test, finally a simplified two-degree-of-freedom (TDOF) model was proposed for CFRP grid reinforced ECC layer strengthened RC beams under impact loading. The results showed that CFRP grid reinforced ECC layer significantly improved the impact resistance of RC beams. When the ECC and CFRP grid were used, the crack development was inhibited after the concrete cracked in the tensile area, avoiding the brittle damage of concrete beams with one crack to the end. Compared with the control beam, the reaction force of RC beams strengthened with CFRP grid and ECC under impact load increased by 16.2%~34.5%, the maximum mid-span displacement decreased by 16.3%~31.6% and the mid-span residual displacement decreased by 36.02%~49.53%. The finite element model and the proposed TDOF mode were demonstrated to effectively simulate the strengthened beam under impact loading.
Development of Geopolymers Based on Fly Ashes from Different Combustion Processes
Authors: Pławecka Kinga , Bazan Patrycja , Lin Wei-Ting , Korniejenko Kinga , Sitarz Maciej , Nykiel Marek
Published: May 2022

The main aim of this research is to assess different fly ashes as raw materials for the manufacturing of geopolymers. Three different fly ashes have been investigated. First, a conventional fly ash from the Skawina coal power plant (Poland), obtained at a temperature of 900–1100 °C. Second, ultra-fine fly ash from a power plant in China; the side product received at 1300 °C. The third fly ash was waste was obtained after combustion in incineration plants. To predict the properties and suitability of materials in the geopolymerization process, methods based on X-ray analysis were used. The applied precursors were tested for elemental and chemical compounds. The investigations of geopolymer materials based on these three fly ashes are also presented. The materials produced on the basis of applied precursors were subjected to strength evaluation. The following research methods were applied for this study: density, X-ray fluorescence (XRF), X-ray diffraction analysis (XRD), Scanning Electron Microscopy (SEM), flexural and compressive strength. The obtained results show that materials based on fly ashes had a similar compressive strength (about 60 MPa), while significant differences were observed during the bending test from 0.1 to 5.3 MPa. Ultra-fine fly ash had a lower flexural strength compared to conventional fly ash. This study revealed the need for process optimization for materials based on a precursor from a waste incineration plant.
Core-Sheath Electrospun Nanofibers Based on Chitosan and Cyclodextrin Polymer for the Prolonged Release of Triclosan
Authors: Ouerghemmi Safa , Degoutin Stéphanie , Maton Mickael , Tabary Nicolas , Cazaux Frédéric , Neut Christel , Blanchemain Nicolas , Martel Bernard
Published: May 2022

This work focuses on the manufacture of core-sheath nanofibers (NFs) based on chitosan (CHT) as sheath and cyclodextrin polymer (PCD) as core and loaded with triclosan (TCL). In parallel, monolithic NFs consisting of blended CHT-PCD and TCL were prepared. Nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier Transform Infrared spectroscopy (FTIR). SEM displayed the morphology of NFs and the structure of the nanowebs, while TEM evidenced the core-sheath structure of NFs prepared by coaxial electrospinning. The core diameters and sheath thicknesses were found dependent on respective flow rates of both precursor solutions. Nanofibers stability and TCL release in aqueous medium were studied and correlated with the antibacterial activity against Staphylococcus aureus and Escherichia coli. Results showed that the release profiles of TCL and therefore the antibacterial activity were directly related to the type of nanofibers. In the case of monolithic nanofibers, the NFs matrix was composed of polyelectrolyte complex (PEC formed between CHT and PCD) and resulted in a prolonged release of TCL and a sustained antibacterial effect. In the case of core-sheath NFs, the PEC was formed only at the core-sheath interface, leading to less stable NFs and therefore to a faster release of TCL, and to a less extended antibacterial activity compared to monolithic ones.
Effects of Type and Content of Fibers, Water-to-Cement Ratio, and Cementitious Materials on the Shrinkage and Creep of Ultra-High Performance Concrete
Authors: Chen Ying , Liu Peng , Sha Fei , Yu Zhiwu , He Sasa , Xu Wen , Lv Maofeng
Published: May 2022

The effects of the type and content of fibers, water to cement ratio (W/C), and content of cementitious materials on the shrinkage and creep of ultra-high performance concrete (UHPC) were investigated. The relationships between curing age, shrinkage, and unit creep of the UHPC were also discussed. The results showed that the shrinkage of the UHPC decreased with the increase in W/C, where there existed a quadratic function between shrinkage and W/C. However, the unit creep of the UHPC increased with W/C. The shrinkage and unit creep of the UHPC increased with the increase in the content of the cementitious materials. The type and content of fibers had different effects on the shrinkage and unit creep of the UHPC, that is, the shrinkage of the UHPC first increased and then decreased with the increase in the content of steel fibers, where there existed a quadratic function between them. There was a linear function between the shrinkage of the UHPC and the content of carbon fibers, but the shrinkage of the UHCP first increased and then decreased with the increase in PVA content. The shrinkage and unit creep of the UHPC at the initial curing age were significant, which tended to be constant with the increase in curing age. Although the steel fibers had a significant inhibiting effect on the unit creep of the UHPC, the carbon fibers and PVA had positive and negative effects on the unit creep of the UHPC. The effects of the type and content of fibers on the shrinkage and unit creep of the UHPC were caused by the slenderness ratio, shape, surface roughness, and elasticity modulus of the fibers. The shrinkage and creep of the UHPC were caused by the chemical autogenous shrinkage and free water evaporation of the UHPC.
Relating Amorphous Structure to the Tear Strength of Polylactic Acid Films
Authors: Kobayashi Yutaka , Ishigami Akira , Ito Hiroshi
Published: May 2022

Compared with polyolefins that are used as single-use plastics, polylactic acid (PLA) has a lower tear strength in films. The relationship between the tear strength and the higher-order structure of films was investigated using PLA films that absorbed moisture at 30 °C and 95% relative humidity (RH) or that had been annealed under reduced pressure conditions. Although the mobile amorphous (MAm) amount did not change under high humidity, the film became brittle due to enthalpy relaxation. The crystallization by annealing also caused embrittlement, and the MAm amount decreased to 10%. The displacement until tearing is lowered from 2.5 to 0.5 mm in both cases. However, in situ retardation measurements revealed that there was a significant difference in the fracture morphology of the torn tip. When crystallized, the molecular chains and crystals are oriented in the tensile direction of the film, and a fragmented structure is observed in the ligament. Embrittlement due to enthalpy relaxation caused a weak orientation perpendicular to the tensile direction of the film, and cracks occurs along with this orientation.
Species Surface Distribution and Surface Tension of Aqueous Solutions of MIBC and NaCl Using Molecular Dynamics Simulations
Authors: Alvarado Omar , Quezada Gonzalo R. , Saavedra Jorge H. , Rozas Roberto E. , Toledo Pedro G.
Published: May 2022

Methyl isobutyl carbinol (MIBC) is a high-performance surfactant with unusual interfacial properties much appreciated in industrial applications, particularly in mineral flotation. In this study, the structure of air–liquid interfaces of aqueous solutions of MIBC-NaCl is determined by using molecular dynamics simulations employing polarizable and nonpolarizable force fields. Density profiles at the interfaces and surface tension for a wide range of MIBC concentrations reveal the key role of polarizability in determining the surface solvation of Cl− ions and the expulsion of non-polarizable Na+ ions from the interface to the liquid bulk, in agreement with spectroscopic experiments. The orientation of MIBC molecules at the water liquid–vapor interface changes as the concentration of MIBC increases, from parallel to the interface to perpendicular, leading to a well-packed monolayer. Surface tension curves of fresh water and aqueous NaCl solutions in the presence of MIBC intersect at a reproducible surfactant concentration for a wide range of salt concentrations. The simulation results for a 1 M NaCl aqueous solution with polarizable water and ions closely capture the MIBC concentration at the intercept. The increase in surface tension of the aqueous MIBC/NaCl mixture below the concentration of MIBC at the intersection seems to originate in a disturbance of the interfacial hydrogen bonding structure of the surface liquid water caused by Na+ ions acting at a distance and not by its presence on the interface.
Tailoring Interfacial Adhesion between PBAT Matrix and PTFE-Modified Microcrystalline Cellulose Additive for Advanced Composites
Authors: Wang Hongkun , Liu Xuran , Liu Jinfeng , Wu Min , Huang Yong
Published: May 2022

Cellulose materials have the potential to serve as sustainable reinforcement in polymer composites, but they suffer from challenges in improving interfacial compatibility with polymers through surface modification. Here, we propose adjusting the interfacial compatibility between microcrystalline cellulose (MCC) and poly (butylene adipate-co-terephthalate) (PBAT) through the strategy based on surface energy regulation. Mechanical ball milling with polytetrafluoroethylene (PTFE) powder was used to simultaneously pulverize, and surface modify MCC to produce MCC sheets with different surface energy. The modified MCC was used to reinforce PBAT composites by simple melt blending. The surface morphology, surface energy of MCC, and the amount of friction transferred PTFE during ball milling were characterized. The mechanical performance, composite morphology, crystallization behavior and dynamic thermomechanical analysis of the composites were investigated. The interfacial adhesion strength of composites closely relates to the surface energy of modified MCC. When the surface energy of MCC is closer to that of the PBAT matrix, it exhibits the better interfacial adhesion strength, resulting in the increased mechanical properties, crystallization temperature, storage modulus, and loss modulus. This work provides effective strategy for how to design fillers to obtain high-performance composites.
The Study of Cyclosporin A Nanocrystals Uptake and Transport across an Intestinal Epithelial Cell Model
Authors: Sun Wenjun , Tian Yang , Wang Zengming , Zhang Hui , Zheng Aiping
Published: May 2022

Cyclosporin A nanocrystals (CsA-NCs) interaction with Caco-2 cells were investigated in this study, including cellular uptake and transport across Caco-2 cell monolayers. CsA-NCs of 165 nm, 240 nm and 450 nm were formulated. The dissolution of CsA-NCs was investigated by paddle method. The effect of size, concentration and incubation time on cellular uptake and dissolution kinetics of CsA-NCs in cells were studied. Uptake mechanisms were also evaluated using endocytotic inhibitors and low temperature (4 °C). The cell monolayers were incubated with each diameter CsA-NCs to evaluate the effect of size on the permeation characteristics of CsA across the intestinal mucosa. The results of dissolution study showed that 165 nm CsA-NC had the highest dissolution rate followed by 240 CsA-NC and finally 450 nm CsA-NC. The saturation of cell uptake of CsA-NCs was observed with the increase of incubation concentration and time. 240 nm and 450 nm CsA-NCs had the lowest and highest uptake efficiency at different time and drug concentration, respectively. The uptake of all three-sized CsA-NCs declined significantly in some different degree after the pre-treatment with different endocytosis inhibitors. 165 nm CsA-NC showed a highest transport capacity across monolayers at the same concentration and time. The results suggest that the size of CsA-NCs can not only affect the efficiency of cellular uptake, but also the type of endocytosis. Decreasing particle size of CsA-NCs can improve transport capacity of CsA through cell monolayer.
Investigations for Design Estimation of an Anisotropic Polymer Matrix Composite Plate with a Central Circular Hole under Uniaxial Tension
Authors: Lim Seongsik , Dhimole Vivek Kumar , Kim Yongbae , Cho Chongdu
Published: May 2022

Composite plates with holes are common in engineering applications, such as the automotive and aerospace industries. Three-dimensional braided carbon/epoxy polymers are an advanced textile composite and are used in various structures due to their high damage resistance and relatively low manufacturing cost. When a braided polymer plate with a hole is used in engineering applications, it is necessary to know its mechanical behavior under loading conditions using analysis theory to design it better. However, the effects of stress distribution with shear deformation theories on the variable thickness of the braided polymer plate (carbon/epoxy) with a hole under tensile loading have not been reported yet. In this paper, a study is conducted to evaluate shear deformation theories for a braided polymer plate with variable thickness and a hole in the center, analyzing the stresses and their concentration variations. First, multiscale modeling and analysis are performed to determine the mechanical properties of the plate. Then, finite element analyses are performed on a homogenized macro plate with a hole. The analysis process is verified by comparison with the available literature. Results show that the first-order shear deformation theory calculates 37, 56, and 70 percent less maximum transverse shear stress than the high-order shear deformation theory (Reissner–Mindlin) and the elasticity theory for thin, moderately thick, and thick braided polymer plates, respectively. Additionally, changing the theory has no significant effect on circumferential stress, radial stress, Von Mises stress, and stress concentration factor. As a result, this research can provide researchers and designers with structural intuition for a braided polymer plate with a center hole.
Conductive Silver/Carbon Fiber Films for Rapid Detection of Human Coronavirus
Authors: Jeon Hwan Gyun , Choi Ji Wook , Lee Hee Uk , Chung Bong Geun
Published: May 2022

Polymerase chain reaction has gained attention since the outbreak of novel coronavirus in 2019. Due to its high specificity and capability for early detection, it is considered a standard method for the diagnosis of infectious diseases. However, the conventional thermocyclers used for nucleic acid amplification are not suitable for point-of-care testing applications, as they require expensive instruments, high-power consumption, and a long turnaround time. To suppress the widespread of the pandemic, there is an urgent need for the development of a rapid, inexpensive, and portable thermal cycler. Therefore, in this paper, we present a conductive silver/carbon fiber film-based thermal cycler with low power consumption (<5 W), efficient heating (~4.5 °C/s), low cost (<USD 200), and handheld size (11.5 × 7.1 × 7.5 mm). The conductive film, which was used as a heating source of the thermal cycler, was fabricated by the electrochemical deposition method. The successful coating of Ag was characterized by a scanning electron microscope and confirmed by energy-dispersive X-ray spectroscopy. The film showed excellent electrical/thermal conductivity and durability. Using our thermal cycler, 35 cycles of amplification were accomplished within 10 min. We also successfully demonstrated the multiplexed detection of various human coronaviruses (e.g., OC43, 229E, and NL63) using our thermal cycler.
Effect of Polymers and Permeation Enhancers in the Release of Quetiapine Fumarate Transdermal Patch through the Dialysis Membrane
Authors: Bhupathyraaj Mullaicharam , Vijaya Rani K. Reeta , Sridhar Sathvik B. , Shareef Javed , Thomas Sabin , Halligudi Nirmala , Sockalingam Anbazhagan , Mohandoss Kiruba , Sundar Shyam
Published: May 2022

Quetiapine Fumarate is potent, and the daily therapeutic dose can be delivered easily across the skin with the help of permeation enhancers. Quetiapine Fumarate-loaded transdermal patches were prepared by solvent evaporation technique. Various formulation parameters, excipients, and their combinations were optimized to get thin, translucent, smooth, stable, and high permeable character patches. A total number of 10 formulations were prepared. All formulations were subjected to various physicochemical evaluations. Three different formulations were prepared and F1, F2, and F3. Various physicochemical studies were carried out and found no significant difference between the three batches. The in vitro release study showed 74.29%, 82.73%, and 77.27%, respectively, up to 24 h. From the results, F2 has been selected as an optimized formulation and evaluated for skin irritation test. The results revealed that there is no irritation produced. The stability study results showed that there is no significant change from its initial nature till the period of three months in both temperatures. Quetiapine Fumarate Transdermal Patch F2 has achieved the goal of extended-release, cost-effectiveness, lowering the dose and frequency of drug administration, and thus may improve patient compliance.
3D Printing of Stretchable, Adhesive and Conductive Ti3C2Tx-Polyacrylic Acid Hydrogels
Authors: Zhao Weijing , Cao Jie , Wang Fucheng , Tian Fajuan , Zheng Wenqian , Bao Yuqian , Zhang Kaiyue , Zhang Zhilin , Yu Jiawen , Xu Jingkun , Liu Ximei , Lu Baoyang
Published: May 2022

Stretchable, adhesive, and conductive hydrogels have been regarded as ideal interfacial materials for seamless and biocompatible integration with the human body. However, existing hydrogels can rarely achieve good mechanical, electrical, and adhesive properties simultaneously, as well as limited patterning/manufacturing techniques posing severe challenges to bioelectronic research and their practical applications. Herein, we develop a stretchable, adhesive, and conductive Ti3C2Tx-polyacrylic acid hydrogel by a simple pre-crosslinking method followed by successive direct ink writing 3D printing. Pre-polymerization of acrylic acid can be initiated by mechanical mixing with Ti3C2Tx nanosheet suspension, leading to the formation of viscous 3D printable ink. Secondary free radical polymerization of the ink patterns via 3D printing can achieve a stretchable, adhesive, and conductive Ti3C2Tx-polyacrylic acid hydrogel. The as-formed hydrogel exhibits remarkable stretchability (~622%), high electrical conductivity (5.13 S m−1), and good adhesion strength on varying substrates. We further demonstrate the capability of facilely printing such hydrogels into complex geometries like mesh and rhombus patterns with high resolution and robust integration.
Mass Transport of Lignin in Confined Pores
Authors: Ghaffari Roujin , Almqvist Henrik , Nilsson Robin , Lidén Gunnar , Larsson Anette
Published: May 2022

A crucial step in the chemical delignification of wood is the transport of lignin fragments into free liquor; this step is believed to be the rate-limiting step. This study has investigated the diffusion of kraft lignin molecules through model cellulose membranes of various pore sizes (1–200 nm) by diffusion cells, where the lignin molecules diffuse from donor to acceptor cells through a membrane, where diffusion rate increases by pore size. UV–vis spectra of the donor solutions showed greater absorbance at higher wavelengths (~450 nm), which was probably induced by scattering due to presence of large molecules/clusters, while acceptor samples passed through small pore membranes did not. The UV–vis spectra of acceptor solutions show a characteristic peak at around 350 nm, which corresponds to ionized conjugated molecules: indicating that a chemical fractionation has occurred. Size exclusion chromatography (SEC) showed a difference in the molecular weight (Mw) distribution between lignin from the donor and acceptor chambers. The results show that small pore sizes enable the diffusion of small individual molecules and hinder the transport of large lignin molecules or possible lignin clusters. This study provides more detail in understanding the mass transfer events of pulping processes.
Updated Perceptions on Polymer-Based Enhanced Oil Recovery toward High-Temperature High-Salinity Tolerance for Successful Field Applications in Carbonate Reservoirs
Authors: Hassan Anas M. , Al-Shalabi Emad W. , Ayoub Mohammed A.
Published: May 2022

The aging of the existing reservoirs makes the hydrocarbon extraction shift toward newer reserves, and harsh conditioned carbonates, which possess high temperature and high salinity (HTHS). Conventional polymer-flooding fails in these HTHS carbonates, due to precipitation, viscosity loss, and polymer adsorption. Therefore, to counteract these challenges, novel polymer-based cEOR alternatives employ optimized polymers, polymer–surfactant, and alkali–surfactant–polymer solutions along with hybrid methods, which have shown a potential to target the residual or remaining oils in carbonates. Consequently, we investigate novel polymers, viz., ATBS, Scleroglucan, NVP-based polymers, and hydrophobic associative polymers, along with bio-polymers. These selected polymers have shown low shear sensitivity, low adsorption, and robust thermal/salinity tolerance. Additionally, adding an alkali-surfactant to polymer solution produces a synergy effect of improved mobility control, wettability alteration, and interfacial-tension reduction. Thus, enhancing the displacement and sweep efficiencies. Moreover, low-salinity water can precondition high-salinity reservoirs before polymer flooding (hybrid method), to decrease polymer adsorption and viscosity loss. Thus, this paper is a reference for novel polymers, and their hybrid techniques, to improve polymer-based cEOR field applications under HTHS conditions in carbonates. Additionally, the recommendations can assist in project designs with reasonable costs and minimal environmental impact. The implication of this work will aid in supplementing the oil and gas energy sector growth, making a positive contribution to the Middle Eastern economy.
Response to Mono-Energetic Neutrons and Light Output Function for Liquid Organic Scintillators PYR5/DIPN and THIO5/DIPN
Authors: Jánský Jaroslav , Janda Jiří , Košťál Michal , Matěj Zdeněk , Bílý Tomáš , Mazánková Věra , Mravec Filip , Cvachovec František
Published: May 2022

Liquid organic scintillators are important devices for measurements of neutron radiation. Currently, large-scale liquid organic scintillators have capabilities of detecting neutrons, but the determination of the neutron energy spectra is a challenge. This work aims to measure the responses of two liquid two-component scintillators to mono-energetic neutron radiation and to determine their light output function, which is necessary for proper neutron energy spectra determination. Both scintillators are composed of the solvent di-iso-propyl-naphthalene (DIPN) mixed isomers. The first scintillator, labeled PYR5/DIPN, contains the luminophore 1-phenyl-3-(2,4,6-trimethyl-phenyl)-2-pyrazoline with a concentration of 5 g/L. The second scintillator labeled THIO5/DIPN contains the luminophore 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene also with a concentration of 5 g/L. The responses to neutron energies of 1.5 MeV, 2.5 MeV, and 19 MeV are measured at PTB in Braunschweig. The responses to neutron energies of 2.45 MeV and 14 MeV were measured at CTU in Prague using DD and DT reactions. The responses to a silicon filtered beam were measured at Research Centre Řež. The measurements were processed using a two-parameter spectrometric system NGA-01 to discriminate neutrons from gamma rays. The obtained responses are dominated by recoil protons from elastic collisions of neutrons with hydrogen atoms. The edge of the response of recoil protons gives information about the light output of neutrons, compared to gamma rays for the same radiation energy. The light output function for protons in the PYR5/DIPN scintillator is L(Ep)=0.6294Ep−1.00(1−exp(−0.4933Ep0.95)). The light output function for protons in the THIO5/DIPN scintillator is L(Ep)=0.6323Ep−1.00(1−exp(−0.4986Ep0.9883)). The light output functions well resemble the standard shape, and they are quite similar to each other. That suggests a weak influence of the luminophore on the light output function. The light output functions are ready to be incorporated to the response matrix for the neutron energy spectra determination.
An Unnoticed Jacob–Esau Allusion in Acts
Authors: Moxon John R. L.
Published: May 2022

A suggestion is made about a possible but hitherto unnoticed Jacob–Esau allusion in the Petrine vision of Acts 10. This not only fits well with the dense scriptural intertexture already observed for the passage but may further illuminate the tense issues involved, both in the impending Cornelius visit and in the related Acts 15 conference. Besides offering a close match to Acts 10:13 in the fateful meal invitation of Gen 27:19, the Jacob–Esau story was not only widely used in relation to the Jew–gentile divide but also displays a strong connection to food and the capture and slaughter of animals. Jewish traditions about the source of Esau’s power over “all the beasts of the field and birds of the air” may lie behind the otherwise curious image in the vision. The story’s brooding sense of conflict and deception and the vulnerability of the ailing Isaac, whose persona Peter is invited to assume, all contribute to the destabilisation the vision seeks to achieve.