Protocol to operate a large-scale CO2 hydrogenation process for formic acid production.

Formic acid is a viable product of CO2 utilization. Here, we present a protocol for designing and operating a pilot-scale formic acid production plant with a 10 kg/day capacity produced via CO2 hydrogenation. We describe the essential process specifications required for successful operation, including prevention of corrosion and formic acid decomposition. We then detail procedures for steady-state operation of the individual units. This protocol provides the necessary information for further scale-up and commercialization of the CO2 hydrogenation process. For complete details on the use and execution of this protocol, please refer to Kim et al.1.

Association between intra-individual variability and prefrontal cortex activity measured by functional Near Infrared Spectroscopy (fNIRS) in children with ADHD.

This study uses fNIRS to determine whether there is a difference in the relationship between intra-individual variability and frontal lobe activity between ADHD patients and typically developing children. A total of 28 subjects (14 in ADHD patient group and 14 in control group) participated in this study. The subjects were tested for K-SADS and intelligence, and then the frontal lobe activity of the subjects was measured by continuous performance test, using functional near-infrared spectroscopy (NIRSIT). Processing speed index was significantly lower in the ADHD patient group than in the control group (p = .04). The CPT test results showed a positive correlation in the activity of the right dorsolateral prefrontal region in the patient group, but not at a statistically significant level. In the control group, activity showed a significant level of negative correlation with commission and hit reaction time standard deviation (p = .023; p = .063 respectively). In contrary to ADHD patient group, activation of the right dorsolateral prefrontal area was significantly correlated with reduction of intra-individual variability. This result showing that the relationship between activation of the right dorsolateral prefrontal area of the ADHD patient group and intra-individual variability shows a different pattern from typically developing children.

Economically viable co-production of methanol and sulfuric acid via direct methane oxidation.

The direct oxidation of methane to methanol has been spotlighted research for decades, but has never been commercialized. This study introduces cost-effective process for co-producing methanol and sulfuric acid through a direct oxidation of methane. In the initial phase, methane oxidation forms methyl bisulfate (CH3OSO3H), then transformed into methyl trifluoroacetate (CF3CO2CH3) via esterification, and hydrolyzed into methanol. This approach eliminates the need for energy-intensive separation of methyl bisulfate from sulfuric acid by replacing the former with methyl trifluoroacetate. Through the superstructure optimization, our sequential process reduces the levelized cost of methanol to nearly two-fold reduction from the current market price. Importantly, this process demonstrates adaptability to smaller gas fields, assuring its economical operation across a broad range of gas fields. The broader application of this process could substantially mitigate global warming by utilizing methane, leading to a significantly more sustainable and economically beneficial methanol industry.

User preference optimization for control of ankle exoskeletons using sample efficient active learning.

One challenge to achieving widespread success of augmentative exoskeletons is accurately adjusting the controller to provide cooperative assistance with their wearer. Often, the controller parameters are "tuned" to optimize a physiological or biomechanical objective. However, these approaches are resource intensive, while typically only enabling optimization of a single objective. In reality, the exoskeleton user experience is likely derived from many factors, including comfort, fatigue, and stability, among others. This work introduces an approach to conveniently tune the four parameters of an exoskeleton controller to maximize user preference. Our overarching strategy is to leverage the wearer to internally balance the experiential factors of wearing the system. We used an evolutionary algorithm to recommend potential parameters, which were ranked by a neural network that was pretrained with previously collected user preference data. The controller parameters that had the highest preference ranking were provided to the exoskeleton, and the wearer responded with real-time feedback as a forced-choice comparison. Our approach was able to converge on controller parameters preferred by the wearer with an accuracy of 88% on average when compared with randomly generated parameters. User-preferred settings stabilized in 43 ± 7 queries. This work demonstrates that user preference can be leveraged to tune a partial-assist ankle exoskeleton in real time using a simple, intuitive interface, highlighting the potential for translating lower-limb wearable technologies into our daily lives.

Toward economical application of carbon capture and utilization technology with near-zero carbon emission.

Carbon capture and utilization technology has been studied for its practical ability to reduce CO2 emissions and enable economical chemical production. The main challenge of this technology is that a large amount of thermal energy must be provided to supply high-purity CO2 and purify the product. Herein, we propose a new concept called reaction swing absorption, which produces synthesis gas (syngas) with net-zero CO2 emission through direct electrochemical CO2 reduction in a newly proposed amine solution, triethylamine. Experimental investigations show high CO2 absorption rates (>84%) of triethylamine from low CO2 concentrated flue gas. In addition, the CO Faradaic efficiency in a triethylamine supplied membrane electrode assembly electrolyzer is approximately 30% (@-200 mA cm-2), twice higher than those in conventional alkanolamine solvents. Based on the experimental results and rigorous process modeling, we reveal that reaction swing absorption produces high pressure syngas at a reasonable cost with negligible CO2 emissions. This system provides a fundamental solution for the CO2 crossover and low system stability of electrochemical CO2 reduction.

Development of a Seoul-Type Housing Service Model for People With a Mental Illness.

OBJECTIVE: To establish and to promote the qualitative development of a housing service model in South Korea. METHODS: The questionnaire was collected through the housing needs survey and the focus group interview on the mental health professions. We enrolled 365 subjects from 63 places (community conversion facilities, cohabitation, cohabitation families, hospitals, psychiatric nursing homes) to answer the questionnaires. RESULTS: The survey result confirms the needs of people with a mental illness to be self-reliant, but it shows that the economic vulnerability is a hindrance. In addition, the most necessary factor for self-reliant living is to provide services that support daily living. Therefore, the study points out that a system that guarantees self-reliance must be added in order for the housing services to be distributed throughout local communities for the people with mental illness. CONCLUSION: The study proposes the Seoul-type housing services model to replace the housing services that functions in a fragmented manner with the provision of an integrated services through a unified channel by establishing a housing support center (tentative name). This will ultimately help people with a mental illness to live a healthy life that meets their needs as community members.

The Association Between Alcohol Use and Suicidal Ideation Among Employees.

OBJECTIVE: The risk of suicide is assessed by identifying the relationship between alcohol-use patterns and suicidal ideation in Korean employees. METHODS: The study involved 13,858 employees who underwent workplace mental health screening at the Workplace Mental Health Institute of Kangbuk Samsung Hospital over a 6-year period between 2014 and 2019. Analysis was performed separately for Alcohol Use Disorders Identification Test-Korea (AUDIT-K) items related to the frequency/volume of alcohol consumption (items 1 to 3, AUDIT-C) and those regarding alcohol dependence/related problems (items 4 to 10, AUDIT-D/P). Subjects were then classified into three groups on the basis of the presence or absence of clinical depression and suicidal ideation. The groups' sociodemographic factors and clinical features of depression, anxiety, and alcohol-use patterns were analyzed with a chi-square test as well as one-way analysis of variance, followed by a post hoc test using the Bonferroni correction. RESULTS: AUDIT-K and AUDIT-D/P scores were significantly associated with the presence or absence of clinical depression as well as the presence or absence of suicidal ideation (p<0.05). However, no significant differences were found among the three groups with regard to the AUDIT-C score (p=0.054). CONCLUSION: Identifying or treating alcohol dependence/related problems can help lower the occurrence of mental health problems, and suicidal ideation in particular, in employees and reduce social costs.

Can insecticide applications used to kill vector insects prevent pine wilt disease?

BACKGROUND: The aerial application of insecticides is a primary method used to prevent the spread of pine wilt disease by reducing the population density of Monochamus beetles, the vector insects of pine wood nematodes (PWNs). This study investigated the mortality of vector insects and the ratio of PWN-infected trees according to systemically remaining thiacloprid residues in Pinus densiflora. To do this, thiacloprid was sprayed on a nursery of 5-year-old P. densiflora in meshed cages. Then Monochamus alternatus adults carrying PWNs were placed into meshed cages 1 and 15 days post-treatment (T1 and T15 groups for thiacloprid spraying, and N1 and N15 groups for nonsprayed groups) and tree mortality was monitored. We also measured the thiacloprid residues in pine branches in each treatment. RESULTS: In pine trees, more thiacloprid residues were found in the T1 group than in the T15 group, but most M. alternatus adults died in the T1 and T15 groups and PWNs were detected in 51.3% of all recaptured beetles. In the 16th week after each treatment, the average tree mortalities in T1 and T15 were 0% and 16.7%, respectively, whereas mortality of ≈50-60% of all tested trees in the nonsprayed groups was observed. CONCLUSION: The current aerial application of insecticides may have a limitation in preventing PWN transmission from dying M. alternatus adults when they are exposed to low thiacloprid residues in pine trees.

Achieving over 15% Efficiency in Solution-Processed Cu(In,Ga)(S,Se)2 Thin-Film Solar Cells via a Heterogeneous-Formation-Induced Benign p-n Junction Interface.

Cu(In,Ga)(S,Se)2 (CIGS) thin-film solar cells have attracted considerable interest in the field of photovoltaic devices due to their high efficiency and great potential for diverse applications. While CdS has been the most favorable n-type semiconductor because of its excellent lattice-match and electronic band alignment with p-type CIGS, its narrow optical band gap (∼2.4 eV) has limited light absorption in underlying CIGS absorber films. Reducing the thickness of CdS films to increase the short-circuit current-density has been less effective due to the following decrease in the open-circuit voltage. To overcome this trade-off between the main parameters, we controlled the formation mechanism of CdS films in chemical bath deposition and established its direct correlation with the properties of p-n junctions. Interestingly, a heterogeneous CdS film formation was found to have a synergetic effect with its ammonia bath solution, effectively reducing charge carrier loss from the shunt paths and interface recombination of CIGS/CdS junctions. With these electrical benefits, the trade-off was successfully alleviated and our best device achieved a power conversion efficiency of 15.6%, which is one of the state-of-the-art CIGS thin-film solar cells prepared using solution-processing techniques.

Catalyst-electrolyte interface chemistry for electrochemical CO2 reduction.

The electrochemical reduction of CO2 stores intermittent renewable energy in valuable raw materials, such as chemicals and transportation fuels, while minimizing carbon emissions and promoting carbon-neutral cycles. Recent technoeconomic reports suggested economically feasible target products of CO2 electroreduction and the relative influence of key performance parameters such as faradaic efficiency (FE), current density, and overpotential in the practical industrial-scale applications. Furthermore, fundamental factors, such as available reaction pathways, shared intermediates, competing hydrogen evolution reaction, scaling relations of the intermediate binding energies, and CO2 mass transport limitations, should be considered in relation to the electrochemical CO2 reduction performance. Intensive research efforts have been devoted to designing and developing advanced electrocatalysts and improving mechanistic understanding. More recently, the research focus was extended to the catalyst environment, because the interfacial region can delicately modulate the catalytic activity and provide effective solutions to challenges that were not fully addressed in the material development studies. Herein, we discuss the importance of catalyst-electrolyte interfaces in improving key operational parameters based on kinetic equations. Furthermore, we extensively review previous studies on controlling organic modulators, electrolyte ions, electrode structures, as well as the three-phase boundary at the catalyst-electrolyte interface. The interfacial region modulates the electrocatalytic properties via electronic modification, intermediate stabilization, proton delivery regulation, catalyst structure modification, reactant concentration control, and mass transport regulation. We discuss the current understanding of the catalyst-electrolyte interface and its effect on the CO2 electroreduction activity.

General technoeconomic analysis for electrochemical coproduction coupling carbon dioxide reduction with organic oxidation.

Electrochemical processes coupling carbon dioxide reduction reactions with organic oxidation reactions are promising techniques for producing clean chemicals and utilizing renewable energy. However, assessments of the economics of the coupling technology remain questionable due to diverse product combinations and significant process design variability. Here, we report a technoeconomic analysis of electrochemical carbon dioxide reduction reaction-organic oxidation reaction coproduction via conceptual process design and thereby propose potential economic combinations. We first develop a fully automated process synthesis framework to guide process simulations, which are then employed to predict the levelized costs of chemicals. We then identify the global sensitivity of current density, Faraday efficiency, and overpotential across 295 electrochemical coproduction processes to both understand and predict the levelized costs of chemicals at various technology levels. The analysis highlights the promise that coupling the carbon dioxide reduction reaction with the value-added organic oxidation reaction can secure significant economic feasibility.

Agroinfiltration-based expression of hairpin RNA in soybean plants for RNA interference against Tetranychus urticae.

The coatomer subunit alpha (COPA) and aquaporin 9 (AQ9) genes from the two-spotted spider mite, Tetranychus urticae, were previously determined to exhibit RNA interference (RNAi)-based lethality when their double-stranded RNAs were systemically delivered via multi-unit chambers (Kwon et al., 2016 [8]). In current study, the hairpin RNAs of the COPA and AQ9 were transiently expressed in soybean plants by agroinfiltration. When T. urticae was fed with the soybean plants agroinfiltrated with the COPA and AQ9 hairpin RNA cassettes, the cumulative mortality increased significantly at 6days post-infestation. Quantitative PCR analysis revealed that the transcript level of both COPA and AQ9 was significantly reduced in T. urticae after 2days post-infestation, thereby confirming that the significant increases in mortality resulted from the knockdown of COPA and AQ9 transcripts. Our findings demonstrate the utility of COPA and AQ9 as potential genes for plant host-mediated RNAi control of T. urticae. In addition, we proved the usefulness of agroinfiltration as a rapid validation tool for confirming the RNAi-based lethality of target genes against arthropod pests before producing transgenic plants as agroinfiltration requires less time and skill to validate transgene function. Furthermore, these findings prove the concept that hairpin RNA expressed in plant hosts can also induce RNAi and eventually kill T. urticae, a sap-sucking pest.

Configurable, wearable sensing and vibrotactile feedback system for real-time postural balance and gait training: proof-of-concept.

BACKGROUND: Postural balance and gait training is important for treating persons with functional impairments, however current systems are generally not portable and are unable to train different types of movements. METHODS: This paper describes a proof-of-concept design of a configurable, wearable sensing and feedback system for real-time postural balance and gait training targeted for home-based treatments and other portable usage. Sensing and vibrotactile feedback are performed via eight distributed, wireless nodes or "Dots" (size: 22.5 × 20.5 × 15.0 mm, weight: 12.0 g) that can each be configured for sensing and/or feedback according to movement training requirements. In the first experiment, four healthy older adults were trained to reduce medial-lateral (M/L) trunk tilt while performing balance exercises. When trunk tilt deviated too far from vertical (estimated via a sensing Dot on the lower spine), vibrotactile feedback (via feedback Dots placed on the left and right sides of the lower torso) cued participants to move away from the vibration and back toward the vertical no feedback zone to correct their posture. A second experiment was conducted with the same wearable system to train six healthy older adults to alter their foot progression angle in real-time by internally or externally rotating their feet while walking. Foot progression angle was estimated via a sensing Dot adhered to the dorsal side of the foot, and vibrotactile feedback was provided via feedback Dots placed on the medial and lateral sides of the mid-shank cued participants to internally or externally rotate their foot away from vibration. RESULTS: In the first experiment, the wearable system enabled participants to significantly reduce trunk tilt and increase the amount of time inside the no feedback zone. In the second experiment, all participants were able to adopt new gait patterns of internal and external foot rotation within two minutes of real-time training with the wearable system. CONCLUSION: These results suggest that the configurable, wearable sensing and feedback system is portable and effective for different types of real-time human movement training and thus may be suitable for home-based or clinic-based rehabilitation applications.

Treadmill exercise alleviates motor deficits and improves mitochondrial import machinery in an MPTP-induced mouse model of Parkinson's disease.

Alpha-synuclein (α-Syn) accumulation is significantly correlated with motor deficits and mitochondrial dysfunction in Parkinson's disease (PD), but the molecular mechanism underlying its pathogenesis is unclear. In this study, we investigated the effects of treadmill exercise on motor deficits and mitochondrial dysfunction in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. Treadmill exercise inhibited dopaminergic neuron loss by promoting the expression of tyrosine hydroxylase (TH) and dopamine transporter (DAT) and seemed to improve cell survival by reducing α-Syn expression. Most importantly, treadmill exercise increased expression of the mitochondrial import machinery proteins TOM-40, TOM-20, and TIM-23. This was associated with decreased α-Syn expression and subsequent upregulation of the mitochondrial proteins COX-I, COX-IV, and mtHSP70. Taken together, these results indicate that treadmill exercise may ameliorate motor deficits and improve mitochondrial dysfunction by reducing α-Syn expression in the MPTP-induced mouse model of PD.

Chungtaejeon, a Korean fermented tea, prevents the risk of atherosclerosis in rats fed a high-fat atherogenic diet.

OBJECTIVE: Hypercholesterolemia is one of the well-established risk factors for cardiovascular mortality and morbidity in coronary heart disease. The aim of this study was to investigate the anti-atherogenic effect of Chungtaejeon (CTJ, a Korean fermented tea) aqueous extract on proliferation and migration of human aortic smooth muscle cells (HASMCs) in vivo and in vitro. METHODS: The authors used high-fat atherogenic diet (HFAD) to induce hyperlipidemia in Wistar rats in in vivo animal experiments and used HASMCs for in vitro cell experiments. For the in vitro cell experiment, the proliferation of HASMCs was evaluated using the MTT assay. Similarly, the expression of matrix metalloproteinases (MMPs) in HASMCs was measured using gelatin zymography. Antimigratory activity of CTJ was revealed using the wound-healing model and Boyden 's chamber assay. In the in vivo experiment, CTJ was administered in three different doses for 20 d from the initiation of the HFAD. After 20 d, the serum lipid profile and total lipid contents in liver were measured. RESULTS: Treatment with CTJ for 24 h dose-dependently inhibited the proliferation and migration of HASMCs and expression of MMP-2 in HASMCs. The oral administration of CTJ at concentrations of 200 and 400 mg/kg decreased the levels of low-density lipoprotein cholesterol, total serum cholesterol and hepatic cholesterol of HFAD-fed rats. CONCLUSION: CTJ possessed strong antiproliferative, antimigratory, as well as lipid-lowering activities. Thus, CTJ can be considered as a therapeutic option in the treatment of high-fat diet-induced atherosclerosis.

Inhibitory effect of snake venom toxin on NF-κB activity prevents human cervical cancer cell growth via increase of death receptor 3 and 5 expression.

We previously found that snake venom toxin inhibits nuclear factor kappa B (NF-κB) activity in several cancer cells. NF-κB is implicated in cancer cell growth and chemoresistance. In our present study, we investigated whether snake venom toxin (SVT) inhibits NF-κB, thereby preventing human cervical cancer cell growth (Ca Ski and C33A). SVT (0-12 µg/ml) inhibited the growth of cervical cancer cells by the induction of apoptotic cell death. These inhibitory effects were associated with the inhibition of NF-κB activity. However, SVT dose dependently increased the expression of death receptors (DRs): DR3, DR5 and DR downstream pro-apoptotic proteins. Exploration of NF-κB inhibitor (Phenylarsine oxide, 0.1 µM) synergistically further increased SVT-induced DR3 and DR5 expressions accompanied with further inhibition of cancer cells growth. Moreover, deletion of DR3 and DR5 by small interfering RNA significantly abolished SVT-induced cell growth inhibitory effects, as well as NF-κB inactivation. Using TNF-related apoptosis-inducing ligand resistance cancer cells (A549 and MCF-7), we also found that SVT enhanced the susceptibility of chemoresistance of these cancer cells through down-regulation of NF-κB, but up-regulation of DR3 and DR5. In vivo study also showed that SVT (0.5 and 1 mg/kg) inhibited tumor growth accompanied with inactivation of NF-κB. Thus, our present study indicates that SVT could be applicable as an anticancer agent for cervical cancer, or as an adjuvant agent for chemoresistant cancer cells.

Bee venom ameliorates lipopolysaccharide-induced memory loss by preventing NF-kappaB pathway.

BACKGROUND: Accumulation of beta-amyloid and neuroinflammation trigger Alzheimer's disease. We previously found that lipopolysaccharide (LPS) caused neuroinflammation with concomitant accumulation of beta-amyloid peptides leading to memory loss. A variety of anti-inflammatory compounds inhibiting nuclear factor kappaB (NF-κB) activation have showed efficacy to hinder neuroinflammation and amyloidogenesis. We also found that bee venom (BV) inhibits NF-κB. METHODS: A mouse model of LPS-induced memory loss used administration of BV (0.8 and 1.6 µg/kg/day, i.p.) to ICR mice for 7 days before injection of LPS (2.5 mg/kg/day, i.p.). Memory loss was assessed using a Morris water maze test and passive avoidance test. For in vitro study, we treated BV (0.5, 1, and 2 µg/mL) to astrocytes and microglial BV-2 cells with LPS (1 µg/mL). RESULTS: We found that BV inhibited LPS-induced memory loss determined by behavioral tests as well as cell death. BV also inhibited LPS-induced increases in the level of beta-amyloid (Aß), ß-and γ-secretases activities, NF-κB and its DNA-binding activity and expression of APP, and BACE1 and neuroinflammation proteins (COX-2, iNOS, GFAP and IBA-1) in the brain and cultured cells. In addition, pull-down assay and molecular modeling showed that BV binds to NF-κB. CONCLUSIONS: BV attenuates LPS-induced amyloidogenesis, neuroinflammation, and therefore memory loss via inhibiting NF-κB signaling pathway. Thus, BV could be useful for treatment of Alzheimer's disease.

Bee venom inhibits growth of human cervical tumors in mice.

We studied whether bee venom (BV) inhibits cervical tumor growth through enhancement of death receptor (DR) expressions and inactivation of nuclear factor kappa B (NF-κB) in mice. In vivo study showed that BV (1 mg/kg) inhibited tumor growth. Similar inhibitory effects of BV on cancer growth in primary human cervical cancer cells were also found. BV (1-5 µg/ml) also inhibited the growth of cancer cells, Ca Ski and C33Aby the induction of apoptotic cell death in a dose dependent manner. Agreed with cancer cell growth inhibition, expression of death receptors; FAS, DR3 and DR6, and DR downstream pro-apoptotic proteins including caspase-3 and Bax was concomitantly increased, but the NF-κB activity and the expression of Bcl-2 were inhibited by treatment with BV in tumor mice, human cancer cell and human tumor samples as well as cultured cancer cells. In addition, deletion of FAS, DR3 and DR6 by small interfering RNA significantly reversed BV-induced cell growth inhibitory effects as well as NF-κB inactivation. These results suggest that BV inhibits cervical tumor growth through enhancement of FAS, DR3 and DR6 expression via inhibition of NF-κB pathway.

Y-shaped ligand-driven gold nanoparticles for highly efficient tumoral uptake and photothermal ablation.

We report functional gold nanoparticles (AuNP) with antibody-like ligands. These particles consist of Y-shaped ligands and AuNP. Transferrin (Tf) and Tat peptide were linked to each head of a Y-shaped poly(ethylene glycol) (PEG)-containing dopamine at one tail site. Also, Y-shaped ligands (with Tf and Tat peptide) were anchored to the surface of the AuNP as the result of noncovalent conjugation of dopamine and the AuNP. Interestingly, the partial shielding of Tat peptides by large Tf molecules rather improved Tf-mediated endocytosis of the AuNP, while minimizing the natural nonspecific cell interaction of Tat peptides. This system resulted in highly improved in vitro/in vivo tumor-selective uptake over AuNP bearing a single ligand (Tf or Tat peptides). Furthermore, this system resulted in significant enhancement of in vivo photothermal tumor cell ablation under light-irradiation conditions for AuNP. We believe that this design is a promising method to easily modify conventional antibodies or ligands to improve their disease-recognition ability.

Multimeric grain-marked micelles for highly efficient photodynamic therapy and magnetic resonance imaging of tumors.

Multimeric grain-marked micelles consisting of an inner core micelle (for Fe3O4 encapsulation) and outer multi-grain micelles (for chlorin e6 (Ce6, a model drug) encapsulation) were fabricated using a micelle-to-micelle conjugation method. Grain micelles (mono-thiol functionalized micelles) were chemically linked to the surface of the core micelle (multi-maleimide functionalized micelle). These micelles enable discrete compartments for Ce6 and iron oxide (Fe3O4) that enable a significantly increased in vivo photodynamic tumor inhibition while preserving high contrast magnetic resonance (MR) imaging of the tumor in vivo.