Optimizing electroactive membrane performance for microalgae harvesting: A response surface methodology study of membrane formulation and operating parameters for electro filtration.

Developing electroactive membranes for filtration has gained importance owing to their effectiveness in mitigating the long-lasting issue of fouling faced with traditional membranes. Here, we developed thin electroactive metallic films on to stainless steel mesh (SSM) using electrodeposition method and evaluated their performance for microalgae harvesting via electro filtration. The effect of electrodeposition parameters on membrane formulation and operating parameters for electro filtration, both in continuous and intermittent modes, were evaluated and optimum values were obtained using response surface methodology (RSM). The optimal combination of electrodeposition parameters is 1000 µA/cm2 and 5 min for deposition current density and time, respectively. Whereas the electric field strength of 20 V/mm with an application time of 1 min is suggested to be the optimal combination of electro filtration parameters for maximized flux recovery and corresponding experimental rejection efficiency of more than 90%. Overall, this research contributes to a better understanding of the parameters governing electro-filtration and offers insights for improving the performance of membrane-based microalgae harvesting systems.

Safety monitoring of COVID-19 vaccines: February 26, 2021, To June 4, 2022, Republic of Korea.

As of June 2022, 5 coronavirus disease 2019 (COVID-19) vaccine brands have been used in Korea's national immunization program. The Korea Disease Control and Prevention Agency has enhanced vaccine safety monitoring through a passive web-based reporting system and active text message-based monitoring. In this study, an enhanced safety monitoring system for COVID-19 vaccines is described and the frequencies and types of adverse events (AEs) associated with the 5 COVID-19 vaccine brands were analyzed. AE reports from the web-based COVID-19 Vaccination Management System and text message-based reports from recipients were analyzed. AEs were classified as nonserious or serious (e.g., death or anaphylaxis). The AE reporting rates were calculated based on the number of COVID-19 vaccine doses administered. A total of 125,107,883 doses were administered in Korea from February 26, 2021, to June 4, 2022. Among them, 471,068 AEs were reported, of which 96.1% were nonserious and 3.9% were serious. Among the 72,609 participants in the text message-based AE monitoring process, a higher AE rate of local and systemic reactions was reported for the 3rd versus 1st doses. A total of 874 cases of anaphylaxis (7.0 per 1,000,000 doses), 4 cases of thrombocytopenia syndrome (TTS), 511 cases of myocarditis (4.1 per 1,000,000 doses), and 210 cases of pericarditis (1.7 per 1,000,000 doses) were confirmed. Six fatalities were causally associated with COVID-19 vaccination (1 of TTS and 5 of myocarditis). Young adult age and female sex were related with a higher AE rate for COVID-19 vaccines. Most reported AEs were nonserious and of mild intensity.

Wound-Healing Effect of Antheraea pernyi Epidermal Growth Factor.

To evaluate the wound-healing effect of Antheraea pernyi epidermal growth factor (ApEGF), we performed the sequence analysis, cloning, and prokaryotic expression of cDNA from the ApEGF gene, examined the transcriptional changes, and investigated the wound-healing effect of this protein in cells and rat epidermis. Primers were designed based on available sequence information related to the ApEGF gene in a public database, and part of the ApEGF sequence was obtained. The full-length cDNA sequence of ApEGF was obtained using inverse PCR. The gene sequence fragment of ApEGF was 666 bp in length, encoding 221 amino acids, with a predicted protein mass of 24.19 kD, an isoelectric point of 5.15, and no signal peptide sequence. Sequence homology analysis revealed 86.1% sequence homology with Bombyx mori, 92.7% with Manducal sexta, 92.6% with Trichoplusia ni, and 91.8% with Helicoverpa armigera. ApEGF was truncated and then subjected to prokaryotic expression, isolation, and purification. Truncated ApEGF was used for wound-healing experiments in vitro and in vivo. The results showed that after 48 h, transforming growth factor (TGF)-ß1 had 187.32% cell growth effects, and the ApEGF group had 211.15% cell growth compared to the control group in vitro. In rat epidermis, truncated ApEGF showed a significantly better healing effect than the control. This result indicated that ApEGF, which exerted a direct wound-healing effect, could be used in wound-healing therapy.

Triphenylphosphonium Modified Mesoporous Silica Nanoparticle for Enhanced Algicidal Efficacy of Cyclohexyl-(3,4-dichlorobenzyl) Amine.

Mesoporous silica nanoparticles (MSNPs) have been widely used for the delivery of different hydrophilic and hydrophobic drugs owing to their large surface area and ease of chemical alteration. On the other hand, triphenylphosphonium cation (TPP+) with high lipophilicity has a great mitochondrial homing property that stimulates the internalization of drugs into cells. Therefore, we designed a TPP-modified MSNP to enhance the algicidal activity of our new algicidal agent cyclohexyl-(3,4-dichlorobenzyl) amine (DP92). In this study, algicidal activity was evaluated by assessing the growth rate inhibition of two harmful algal blooms (HABs), Heterosigma akashiwo and Heterocapsa circularisquama, after treatment with DP92-loaded MSNP or TPP-MSNP and DP92 in DMSO (as control). For H. akashiwo, the IC50 values of TPP-MSNP and MSNP are 0.03 ± 0.01 and 0.16 ± 0.03 µM, respectively, whereas the value of the control is 0.27 ± 0.02 µM. For H. circularisquama, the IC50 values of TPP-MSNP and MSNP are 0.10 ± 0.02 and 0.29 ± 0.02 µM, respectively, whereas the value of the control is 1.90 ± 0.09 µM. Results have indicated that TPP-MSNP efficiently enhanced the algicidal activity of DP92, signifying the prospect of using DP92-loaded TPP-MSNP as an algicidal agent for the superior management of HABs.

Novel metallic stainless-steel mesh-supported conductive membrane and its performance in the electro-filtration process.

In this study, we demonstrate the fabrication of a thoroughly metallic electro-conductive membrane by using simple filtration to uniformly coat AgNWs dispersion through stainless steel (SUS)-mesh, which functions both as filter and a flexible conductive substrate. The as-prepared AgNWs networks layer on the SUS-mesh was further strengthened by electroplating Ag layers (P-SUS membrane); exhibiting an overall electrical conductivity of 9.2 × 104 S/m, which is up to 42 times greater than the conductivity of pristine SUS-mesh. The P-SUS membrane exhibited adequate physical durability against chemical and mechanical stresses under prolonged filtration, and high pure water flux of 534 ± 54 LMH/bar. This electro-membrane displayed the anticipated flux recovery in harvesting microalgae (Chlorella sp. HS-2) when filtration was done with the membrane used as a cathode: micro-sized bubbles, generated from the cathodic membrane, functioned to detach the foulants and recover the relative flux to a significant level. The P-SUS membrane indeed possesses necessary traits that the polymer-support membrane lacks, in terms of not only electrical conductivity and mechanical strength but also filtration performance with anti-fouling capability, all of which are of necessity to be considered workable electroconductive membrane.

Biological Effects of the Novel Mulberry Surface Characterized by Micro/Nanopores and Plasma-Based Graphene Oxide Deposition on Titanium.

PURPOSE: This paper presents a technique for developing a novel surface for dental implants using a combination of nitriding and anodic oxidation, followed by the deposition of graphene oxide using atmospheric plasma. The effects of various surface treatments on bacterial adhesion and osteoblast activation were also evaluated. METHODS: CP titanium (control) was processed into disk-shaped specimens. Nitriding was conducted using vacuum nitriding, followed by anodic oxidation, which was performed in an electrolyte using a DC power supply, to form the novel "mulberry surface." Graphene oxide deposition was performed using atmospheric plasma with an inflow of carbon sources. After analyzing the sample surfaces, antibacterial activity was evaluated using Streptococcus mutans and Porphyromonas gingivalis bacteria. The viability, adhesion, proliferation, and differentiation of osteoblasts were also assessed. Analysis of variance (ANOVA) with Tukey's post-hoc test was used to calculate statistical differences. RESULTS: We observed that the mulberry surface was formed on samples treated with nitriding and anodic oxidation, and these samples exhibited more effective antibacterial activity than the control. We also found that the samples with additional graphene oxide deposition exhibited better biocompatibility, which was validated by osteoblast adhesion, proliferation, and differentiation. CONCLUSION: The development of the mulberry surface along with graphene oxide deposition inhibits bacterial adhesion to the implant and enhances the adhesion, proliferation, and differentiation of osteoblasts. These results indicate that the mulberry surface and graphene oxide deposition together can inhibit peri-implantitis and promote osseointegration.

Suppressing High-Current-Induced Phase Separation in Ni-Rich Layered Oxides by Electrochemically Manipulating Dynamic Lithium Distribution.

Understanding the cycling rate-dependent kinetics is crucial for managing the performance of batteries in high-power applications. Although high cycling rates may induce reaction heterogeneity and affect battery lifetime and capacity utilization, such phase transformation dynamics are poorly understood and uncontrollable. In this study, synchrotron-based operando X-ray diffraction is performed to monitor the high-current-induced phase transformation kinetics of LiNi0.6 Co0.2 Mn0.2 O2 . The sluggish Li diffusion at high Li content induces different phase transformations during charging and discharging, with strong phase separation and homogeneous phase transformation during charging and discharging, respectively. Moreover, by exploiting the dependence of Li diffusivity on the Li content and electrochemically tuning the initial Li content and distribution, phase separation pathway can be redirected to solid solution kinetics at a high charging rate of 7 C. Finite element analysis further elucidates the effect of the Li-content-dependent diffusion kinetics on the phase transformation pathway. The findings suggest a new direction for optimizing fast-cycling protocols based on the intrinsic properties of the materials.

Direct-Deposited Graphene Oxide on Dental Implants for Antimicrobial Activities and Osteogenesis.

OBJECTIVE: To determine the effects of graphene oxide (GO) deposition (on a zirconia surface) on bacterial adhesion and osteoblast activation. METHODS: An atmospheric pressure plasma generator (PGS-300) was used to coat Ar/CH4 mixed gas onto zirconia specimens (15-mm diameter × 2.5-mm thick disks) at a rate of 10 L/min and 240 V. Zirconia specimens were divided into two groups: uncoated (control; Zr) group and GO-coated (Zr-GO) group. Surface characteristics and element structures of each specimen were evaluated by field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and contact angle. Additionally, crystal violet staining was performed to assess the adhesion of Streptococcus mutans. WST-8 and ALP (Alkaline phosphatase) assays were conducted to evaluate MC3T3-E1 osteoblast adhesion, proliferation, and differentiation. Statistical analysis was calculated by the Mann-Whitney U-test. RESULTS: FE-SEM and Raman spectroscopy demonstrated effective GO deposition on the zirconia surface in Zr-GO. The attachment and biofilm formation of S. mutans was significantly reduced in Zr-GO compared with that of Zr (P < 0.05). While no significant differences in cell attachment of MC3T3-1 were observed, both proliferation and differentiation were increased in Zr-GO as compared with that of Zr (P < 0.05). SIGNIFICANCE: GO-coated zirconia inhibited the attachment of S. mutans and stimulated proliferation and differentiation of osteoblasts. Therefore, GO-coated zirconia can prevent peri-implantitis by inhibiting bacterial adhesion. Moreover, its osteogenic ability can increase bone adhesion and success rate of implants.

Data on the effect of particle size, porosity and discharging rate on the performance of lithium-ion battery with NMC 622 cathode through numerical analysis.

The data presented in this article are related to the computed results reported in the article entitled "A modeling approach to study the performance of Ni-rich layered oxide cathode for lithium-ion battery" [1]. The lithium-ion battery (LIB) employed in the simulation is made up of a LiNi0.6Mn0.2Co0.2O2 (NMC 622) cathode and lithium metal foil anode. The numerical simulations were carried out using COMSOL Multiphysics 5.4 software which is based on the finite element (FE) method. The data presented in this manuscript shows how varying particle size and porosity affect the performance of the battery as the discharging rate is varied. Four different particle sizes and six different porosities were varied for the purpose of understanding the above behavior. The data presented can be used to further the analysis reported in the accompanying manuscript and aid in design of other cathode materials for LIB and other battery systems. It can also be used to compare some measured results for validation purposes. A comprehensive analysis of the data is found in [1].

Effect of Plasma Surface Treatment on Shear Bond Strength with Denture Base Resin in Co-Cr Alloy, Ti-6Al-4V Alloy, and CP-Ti Alloy.

The purpose of this study was to examine the effect of plasma treatment by treating the surface of Co-Cr alloy, Ti-6Al-4V alloy, and CP-Ti alloy as a material for denture metal frameworks with non-thermal atmospheric pressure plasma (NTAPP) and measuring their shear bond strength (SBS) with a heat-cured resin. 20 specimens were prepared for each of Co-Cr, Ti-6Al-4V, and CP-Ti alloys. Each metal alloy group was divided into the following subgroups depending on NTAPP treatment: C (Co-Cr alloy without plasma), T (CP-Ti without plasma), A (Ti-6Al-4V alloy without plasma), CP (Co-Cr alloy with plasma), TP (CP-Ti with plasma) and AP (Ti-6Al-4V alloy with plasma). Specimens were treated with a metal conditioner and bonded to a denture base resin. SBS was measured using a universal testing machine. All data obtained were statistically analyzed using two-way analysis of variance (ANOVA), Tukey's honestly significant difference (HSD) test, and independent t-test. The mean values (SD) of SBS (MPa) were: 10.31 (1.19) for C group; 12.43 (0.98) for T group; 13.75 (2.02) for A group; 13.53 (1.61) for CP group; 16.87 (1.55) for TP group; 17.46 (1.65) for AP group. The SBS of the AP group was the highest while that of the C group was the lowest. SBS of specimen treated with NTAPP was significantly increased regardless of metal alloy types (p < 0.001). Within the limitations of this study, NTAPP can increases the SBS of Co-Cr alloy, CP-Ti alloy, and Ti-6Al-4V alloy with a denture base resin.

Author Correction: Surface plasmon enhanced Organic color image sensor with Ag nanoparticles coated with silicon oxynitride.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Surface plasmon enhanced Organic color image sensor with Ag nanoparticles coated with silicon oxynitride.

As organic photodetectors with less than 1 µm pixel size are in demand, a new way of enhancing the sensitivity of the photodetectors is required to compensate for its degradation due to the reduction in pixel size. Here, we used Ag nanoparticles coated with SiOxNy as a light-absorbing layer to realize the scale-down of the pixel size without the loss of sensitivity. The surface plasmon resonance appeared at the interface between Ag nanoparticles and SiOxNy. The plasmon resonance endowed the organic photodetector with boosted photon absorption and external quantum efficiency. As the Ag nanoparticles with SiOxNy are easily deposited on ITO/SiO2, it can be adapted into various organic color image sensors. The plasmon-supported organic photodetector is a promising solution for realizing color image sensors with high resolution below 1 µm.

Can algicide (the thiazolidinedione derivative TD49) truly contribute to the restoration of microbial communities?

Harmful algal blooms (HABs) are becoming a more serious ecological threat to marine environments; they not only produce toxins, resulting in the death of marine organisms, but they also adversely affect biodiversity, which is an indicator of the health of an ecosystem. Thus, to mitigate HABs, numerous studies have been conducted to develop an effective algicide, but few studies have elucidated the effect of algicides on marine environmental health. In this study, thiazolidinedione derivative 49 (TD49), which has been developed as an algicide for the dinoflagellate Heterocapsa circularisquama, was used, and we investigated changes in phytoplankton biomass (abundance, chlorophyll a, and carbon biomass) and biodiversity (diversity, evenness, and richness) following the application of TD49. To gain deeper understanding, a large-scale mesocosm (1300 L) experiment containing control and treatment with four different concentrations (0.2, 0.4, 0.6 and 1 µM) was conducted for 10 days. Based on a previous study, TD49 shows algicidal activity against H. circularisquama depending on its concentration. The phytoplankton biomass in the TD49 treatments was generally lower than that in the control due to the algicidal effect of TD49 on H. circularisquama. The biodiversity indices (e.g., the Shannon-Weaver index) in the treatments were consistently higher than those in the control before depletion of nitrite + nitrate. Interestingly, the 0.6 µM TD49 treatment had higher biodiversity indices than the high-concentration treatment (1 µM), which appeared to show a better algicidal effect. These findings suggest that mitigation of H. circularisquama blooms with TD49 treatment may enhance phytoplankton biodiversity, but treatment with excessively high concentrations can lead to harmful effects. During the study period, regardless of the control and TD49 treatments, the total biomass of phytoplankton gradually decreased from the midpoint of the experiment to the end of the experiment. This was more likely caused by the depletion of nutrients than by the toxicity of TD49.

Effect of thiazolidinedione phenylacetate derivatives on wound-healing activity.

The aim of this work was to evaluate the synthesis and structure-activity relationship of 4-((2,4-dioxothiazolidin-5-ylidene)methyl)phenyl 2-phenylacetate derivatives as potential wound-healing agents. The IC50 values of the lead compounds ranged from 0.01 to 0.05 µM. These compounds also increased the levels of extracellular prostaglandin E2 (PGE2) in A549 cells. Among the synthesized compounds, compounds 66, 67, 69, and 86 increased PGE2 levels 3- to 4-fold of those achieved with the negative control. Introduction of a halogen at the intermediate phenyl ring, compounds 66, 67, 69, and 86 resulted in higher IC50 values, which indicated lower cytotoxicity than that observed upon the introduction of other substituents at the same position. In particular, cells exposed to compound 69 showed significantly improved wound healing, and the wound closure rate achieved was approximately 3.2-fold higher than that of the control. Therefore, compound 69 can be used for tissue regeneration and treatment of diverse diseases caused by PGE2 deficiency. Overall, our findings suggested that compound 69 might be a novel candidate for skin wound therapy.

In-Vitro Mechanical Performance Study of Biodegradable Polylactic Acid/Hydroxyapatite Nanocomposites for Fixation Medical Devices.

Osteoconductive, biocompatible, and resorbable organic/inorganic composites are most commonly used in fixation medical devices, such as suture anchors and interference screws, because of their unique physical and chemical properties. Generally, studies on biodegradable composites have focused on their mechanical properties based on the composition and the individual roles of organic and inorganic biomaterials. In this study, we prepared biodegradable organic/inorganic nanocomposite materials using the solvent mixing process and conventional molding. We used polylactic acid (PLA) as the matrix and nano-sized hydroxyapatite (nano-HAp) as the osteoconductive filler. The content of nano-HAp was varied in 0-30 wt% and its influence on the In-Vitro mechanical performance of PLA/HAp nanocomposites was evaluated. The In-Vitro mechanical properties of nanocomposites were evaluated using standardized tensile and flexural tests after different immersion times in simulated body fluid.

Polylactic Acid/Nanostructured Si-Substituted ß-Tricalcium Phosphate Composites for Biodegradable Fixation Medical Devices.

Organic/inorganic biocomposite materials for biodegradable fixation medical devices require osteoconductivity, biocompatibility, and adequate mechanical properties with biodegradation behavior. The objective of this study was to investigate the effect of Si ions substituted in ß-tricalcium phosphate (ß-TCP) on the mechanical properties of organic/inorganic biocomposites. Biodegradable composite materials were prepared with polylactic acid (PLA) as the matrix and nano Si-substituted ß-TCP as the osteoconductive filler by solvent mixing and conventional molding. The nanostructured Si-substituted ß-TCP powders were synthesized by co-precipitation, controlling the quantity of Si ions. The amount of nanostructured Si-substituted ß-TCP powders in composites was varied in the 0-40 wt% range and the material properties were compared with those of pure ß-TCP/PLA composites. The influence of Si ions on the mechanical properties of the composites was evaluated by tensile and flexural tests.

Mixture risk assessment of selected mainstream cigarette smoke constituents generated from low-yield cigarettes in South Korean smokers.

A total of 38 hazardous constituents in mainstream cigarette smoke of low-yield cigarettes sold in Korea were selected and analyzed using established methods. Risk calculations were performed using risk algorithms employed in previous studies and Korean population-based exposure parameters. The median cumulative incremental lifetime cancer risk of male smokers could vary from 828 × 10-6 to 2510 × 10-6, and that of female smokers could range from 440 × 10-6 to 1300 × 10-6, depending on the smoking regimens. The median hazard index as the sum of hazard quotients of male smokers varied from 367 to 1,225, and that of female smokers varied from 289 to 970, depending on the smoking regimens. The sensitivity analysis for this risk assessment indicated that the constituent yields in mainstream cigarette smoke, average number of cigarettes smoked per day or year, and mouth-spill rate are the main risk factors. Statistical positive correlations between the average daily dose calculated by the exposure algorithm used in this study for individual smokers and biomarkers verified the reliability of this assessment. It could be concluded that inhalation of the constituents present in the mainstream of low-yield cigarettes has significant cancer and non-cancer health risks, although its effect on risk reduction is still unknown under the fixed machine-smoking conditions.

The wound-healing effect of 7,3',4'-trimethoxyflavone through increased levels of prostaglandin E2 by 15-hydroxyprostaglandin dehydrogenase inhibition.

OBJECTIVE: To find an inhibitor of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) that rapidly metabolises Prostaglandin E2 (PGE2) as a mediator of wound healing, we examined seven flavonoids for this role. RESULTS: 7,3',4'-Trimethoxyflavone (TMF) had the lowest IC50 value of 0.34 µM for 15-PGDH inhibition but >400 µM for cytotoxicity, indicating a high therapeutic index. TMF elevated PGE2 levels in a concentration-dependent manner in both A549 lung cancer and HaCaT cells. It also significantly increased mRNA expression of multidrug resistance-associated protein 4 (MRP4) and of prostaglandin transporter (PGT) slightly in HaCaT cells. In addition, TMF facilitated in vitro wound healing in a HaCaT scratch model, which was completely inhibited by adding both 15-PGDH and NAD+ as cofactor, confirming the involvement of PGE2 in its wound healing effect. CONCLUSION: TMF with a high therapeutic index can facilitate wound healing through PGE2 elevation by 15-PGDH inhibition.

Utilization of Starch-Enriched Brewery (Rice Wine) Waste for Mixotrophic Cultivation of Ettlia Sp. YC001 Used in Biodiesel Production.

Starch-enriched brewery waste (SBW), an unexplored feedstock, was investigated as a nutritious low-cost source for the mixotrophic cultivation of Ettlia sp. YC001 for biodiesel production. Stirring, autoclaving, and sonication were assessed for the SBW, in conjunction with pH. Stirring at 55 °C was found to be the best, in terms of the effectiveness of starch hydrolysis and yeast disintegration as well as cost. The treated solutions were found to support the mixotrophic growth of microalgae: 20 g/L of glucose medium resulted in the highest biomass production of 9.26 g/L and one with 10 g/L of glucose showed the best lipid productivity of 244.2 mg/L/day. The unsaturated fatty acids increased in the resulting lipid and thus quality well suited for the transportation fuel. All these suggested that SBW, when treated properly, could indeed serve as a cheap feedstock for microalgae-based biodiesel production.

Modeling of Stresses and Strains during (De)Lithiation of Ni3Sn2-Coated Nickel Inverse-Opal Anodes.

Tin alloy-based anodes supported by inverse-opal nanoscaffolds undergo large volume changes from (de)lithiation during cyclic battery (dis)charging, affecting their mechanical stability. We perform continuum mechanics-based simulation to study the evolution of internal stresses and strains as a function of the geometry of the active layer(s): (i) thickness of Ni3Sn2 single layer (30 and 60 nm) and (ii) stacking sequence of Ni3Sn2 and amorphous Si in bilayers (60 nm thick). For single Ni3Sn2 active layers, a thinner layer displays higher strains and stresses, which are relevant to mechanical stability, but causes lower strains and stresses in the Ni scaffold. For Ni3Sn2-Si bilayers, the stacking sequence significantly affects the deformation of the active layers and thus its mechanical stability due to different lithiation behaviors and volume changes.