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1.
Nat Mater ; 21(6): 647-655, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35618824

RESUMO

Homo- and heterojunctions play essential roles in semiconductor-based devices such as field-effect transistors, solar cells, photodetectors and light-emitting diodes. Semiconductor junctions have been recently used to optically trigger biological modulation via photovoltaic or photoelectrochemical mechanisms. The creation of heterojunctions typically involves materials with different doping or composition, which leads to high cost, complex fabrications and potential side effects at biointerfaces. Here we show that a porosity-based heterojunction, a largely overlooked system in materials science, can yield an efficient photoelectrochemical response from the semiconductor surface. Using self-limiting stain etching, we create a nanoporous/non-porous, soft-hard heterojunction in p-type silicon within seconds under ambient conditions. Upon surface oxidation, the heterojunction yields a strong photoelectrochemical response in saline. Without any interconnects or metal modifications, the heterojunction enables efficient non-genetic optoelectronic stimulation of isolated rat hearts ex vivo and sciatic nerves in vivo with optical power comparable to optogenetics, and with near-infrared capabilities.


Assuntos
Ciência dos Materiais , Semicondutores , Porosidade
2.
Sensors (Basel) ; 23(14)2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37514671

RESUMO

Although Short-Wave Infrared (SWIR) sensors have advantages in terms of robustness in bad weather and low-light conditions, the SWIR images have not been well studied for automated object detection and tracking systems. The majority of previous multi-object tracking studies have focused on pedestrian tracking in visible-spectrum images, but tracking different types of vehicles is also important in city-surveillance scenarios. In addition, the previous studies were based on high-computing-power environments such as GPU workstations or servers, but edge computing should be considered to reduce network bandwidth usage and privacy concerns in city-surveillance scenarios. In this paper, we propose a fast and effective multi-object tracking method, called Multi-Class Distance-based Tracking (MCDTrack), on SWIR images of city-surveillance scenarios in a low-power and low-computation edge-computing environment. Eight-bit integer quantized object detection models are used, and simple distance and IoU-based similarity scores are employed to realize effective multi-object tracking in an edge-computing environment. Our MCDTrack is not only superior to previous multi-object tracking methods but also shows high tracking accuracy of 77.5% MOTA and 80.2% IDF1 although the object detection and tracking are performed on the edge-computing device. Our study results indicate that a robust city-surveillance solution can be developed based on the edge-computing environment and low-frame-rate SWIR images.

3.
Entropy (Basel) ; 25(8)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37628159

RESUMO

Increasing wealth inequality is a significant global issue that demands attention. While the distribution of wealth varies across countries based on their economic stages, there is a universal trend observed in the distribution function. Typically, regions with lower wealth values exhibit an exponential distribution, while regions with higher wealth values demonstrate a power-law distribution. In this review, we introduce measures that effectively capture wealth inequality and examine wealth distribution functions within the wealth exchange model. Drawing inspiration from the field of econophysics, wealth exchange resulting from economic activities is likened to a kinetic model, where molecules collide and exchange energy. Within this framework, two agents exchange a specific amount of wealth. As we delve into the analysis, we investigate the impact of various factors such as tax collection, debt allowance, and savings on the wealth distribution function when wealth is exchanged. These factors play a crucial role in shaping the dynamics of wealth distribution.

4.
Int J Mol Sci ; 22(13)2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34281284

RESUMO

Progressive diabetic nephropathy (DN) in diabetes leads to major morbidity and mortality. The major pathological alterations of DN include mesangial expansion, extracellular matrix alterations, tubulointerstitial fibrosis, and glomerular sclerosis. Polygoni avicularis is widely used in traditional oriental medicine and has long been used as a diuretic, astringent, insecticide and antihypertensive. However, to the best of the authors' knowledge, the effects of the ethanolic extract from rhizome of Polygoni avicularis (ER-PA) on DN have not yet been assessed. The present study aimed to identify the effect of ER-PA on renal dysfunction, which has been implicated in DN in human renal mesangial cells and db/db mice and investigate its mechanism of action. The in vivo experiment was performed using Polygoni avicularis-ethanol soluble fraction (ER-PA) and was administrated to db/db mice at 10 and 50 mg/kg dose. For the in vitro experiments, the human renal mesangial cells were induced by high glucose (HG, 25 mM). The ER-PA group showed significant amelioration in oral glucose tolerance, and insulin resistance index. ER-PA significantly improved the albumin excretion and markedly reduced plasma creatinine, kidney injury molecule-1 and C-reactive protein. In addition, ER-PA significantly suppressed inflammatory cytokines. Histopathologically, ER-PA attenuated glomerular expansion and tubular fibrosis in db/db mice. Furthermore, ER-PA suppressed the expression of renal fibrosis biomarkers (TGF and Collagen IV). ER-PA also reduced the NLR family pyrin domain containing 3 inflammatory factor level. These results suggest that ER-PA has a protective effect against renal dysfunction through improved insulin resistance as well as the inhibition of nephritis and fibrosis in DN.


Assuntos
Nefropatias Diabéticas/tratamento farmacológico , Fitoterapia , Polygonum/química , Animais , Células Cultivadas , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Fibrose , Glucose/metabolismo , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Resistência à Insulina , Masculino , Proteínas de Membrana/metabolismo , Células Mesangiais/efeitos dos fármacos , Células Mesangiais/metabolismo , Células Mesangiais/patologia , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Rizoma/química
5.
Nano Lett ; 19(2): 839-849, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30608706

RESUMO

With the advent of artificial intelligence (AI), memristors have received significant interest as a synaptic building block for neuromorphic systems, where each synaptic memristor should operate in an analog fashion, exhibiting multilevel accessible conductance states. Here, we demonstrate that the transition of the operation mode in poly(1,3,5-trivinyl-1,3,5-trimethyl cyclotrisiloxane) (pV3D3)-based flexible memristor from conventional binary to synaptic analog switching can be achieved simply by reducing the size of the formed filament. With the quantized conductance states observed in the flexible pV3D3 memristor, analog potentiation and depression characteristics of the memristive synapse are obtained through the growth of atomically thin Cu filament and lateral dissolution of the filament via dominant electric field effect, respectively. The face classification capability of our memristor is evaluated via simulation using an artificial neural network consisting of pV3D3 memristor synapses. These results will encourage the development of soft neuromorphic intelligent systems.


Assuntos
Cobre/química , Nanoestruturas/química , Nanotecnologia/instrumentação , Redes Neurais de Computação , Siloxanas/química , Inteligência Artificial , Condutividade Elétrica , Desenho de Equipamento , Face/anatomia & histologia , Humanos , Nanotecnologia/métodos
6.
Cent Eur J Immunol ; 41(3): 324-327, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27833452

RESUMO

We previously found a cross-reactive autoantibody that bound to bovine serum albumin generated in a D-galactose-induced aging mouse model. Also, we confirmed that other reducing sugars (glucose and fructose) could induce the formation of autoantibody, and only following subcutaneous injection, not oral or intraperitoneal administration. Mice that had never been exposed to bovine serum albumin produced an anti-bovine serum albumin autoantibody following repeated subcutaneous injection of D-galactose (D-gal). In this study, we investigated the involvement of the adaptive immune system in the production of this autoantibody. In particular, we examined bovine serum albumin-induced splenocyte proliferation and bovine serum albumin-induced active cutaneous and systemic anaphylaxis in D-gal-treated mice. We find our results particularly interesting: bovine serum albumin stimulates splenocyte proliferation and induces both active cutaneous and systemic anaphylaxis in D-gal-treated mice. In summary, our results suggest that adaptive immune response participates in the autoantibody formation against bovine serum albumin in D-gal-treated mice.

7.
Nano Lett ; 14(5): 2647-54, 2014 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-24742260

RESUMO

Here we report an unconventional approach for the single-step synthesis of monolithically integrated electronic devices based on multidimensional carbon structures. Integrated arrays of field-effect transistors and sensors composed of carbon nanotube channels and graphitic electrodes and interconnects were formed directly from the synthesis. These fully integrated, all-carbon devices are highly flexible and can be transferred onto both planar and nonplanar substrates, including papers, clothes, and fingernails. Furthermore, the sensor network can be interfaced with inherent life forms in nature for monitoring environmental conditions. Examples of significant applications are the integration of the devices to live plants or insects for real-time, wireless sensing of toxic gases.


Assuntos
Técnicas Biossensoriais , Monitoramento Ambiental , Grafite/química , Nanotubos de Carbono/química , Animais , Gases/toxicidade , Insetos/fisiologia , Plantas
8.
Cent Eur J Immunol ; 40(1): 25-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26155180

RESUMO

INTRODUCTION: In a previous study, we identified the formation of cross-reactive autoantibodies that bound to bovine serum albumin (BSA) in a D-galactose-induced aging mouse model. AIM OF THE STUDY: In this study, we investigated the effect of other reducing sugars (namely, glucose and fructose) on the formation of autoantibodies. The effects of concentration and route of administration on the formation of autoantibodies were examined in detail. MATERIAL AND METHODS: Three concentrations (100, 500, and 1,000 mg/kg) of reducing sugars were tested. The effects of different routes of administration (subcutaneous, oral, and intraperitoneal) on the formation of autoantibodies were also analysed. The immunoreactivities of serum samples from mice treated with reducing sugars were analysed by an enzyme-linked immunosorbent assay (ELISA) using BSA or mouse serum albumin antigens (MSA). RESULTS: Repeated subcutaneous administration of all reducing sugars lead to autoantibody formation in a concentration-dependent manner. However, these autoantibodies did not cross-react with MSA, and simultaneous treatment of aminoguanidine with reducing sugars did not show any inhibitory effects on the formation of autoantibodies. No autoantibodies were detected after oral or intraperitoneal administration of reducing sugars. Immunohistochemistry data showed that the target antigen(s) of the autoantibodies were present only in the skin tissue of mice treated with reducing sugars. CONCLUSIONS: Our results show that administration of reducing sugars by subcutaneous injection leads to the formation of autoantibodies that cross-react with BSA; the formation and target antigen(s) of the autoantibodies may originate from within the skin tissue treated with the reducing sugars.

9.
Nano Lett ; 13(6): 2814-21, 2013 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-23701320

RESUMO

Transparent electrodes that can remain electrically conductive and stable under large mechanical deformations are highly desirable for applications in flexible and wearable electronics. This paper describes a comprehensive study of the electrical, optical, and mechanical properties of hybrid nanostructures based on two-dimensional graphene and networks of one-dimensional metal nanowires, and their use as transparent and stretchable electrodes. Low sheet resistance (33 Ω/sq) with high transmittance (94% in visible range), robust stability against electric breakdown and oxidation, and superb flexibility (27% in bending strain) and stretchability (100% in tensile strain) are observed, and these multiple functionalities of the hybrid structures suggest a future promise for next generation electronics. The use of hybrid electrodes to fabricate oxide semiconductor transistors and single-pixel displays integrated on wearable soft contact lenses with in vivo tests are demonstrated.


Assuntos
Eletrodos , Grafite/química , Metais/química , Nanofios/química , Lentes de Contato Hidrofílicas , Desenho de Equipamento
10.
Heliyon ; 10(11): e32496, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38912435

RESUMO

Objectives: This study aimed to investigate the performance and reliability of data-driven models employing correlational feature analysis and clinical validation for predicting periodontal disease. Methods: The 7th Korea National Health and Nutrition Examination Survey (n = 10,654) was used for correlation analysis to identify significant risk factors for periodontitis. Periodontal prediction models were developed with the selected factors and database, followed by internal validation with 5-fold cross-validation and 1000 bootstrap resampling. External validation was conducted with clinical data (n = 120) collected through self-reported questionnaires, clinical periodontal parameters, and radiographic image analysis. Predictive performance was assessed for logistics regression, support vector machine, random forest, XGBoost, and neural network algorithms using the area under the receiver operating characteristic curves (AUC) and other performance metrics. Results: Correlation analysis identified 16 features from over 1000 potential risk factors for periodontitis. The best data-driven model (XGBoost) showed AUC values of 0.823 and 0.796 for internal and external validations, respectively. Modeling with clinical data revealed those same measures to be 0.836 and 0.649, respectively. In addition, the data-driven model could predict other clinical periodontal parameters including severe bone loss (AUC = 0.813), gingival bleeding (AUC = 0.694), and tooth loss (AUC = 0.734). A patient case study about prognostic predictions revealed that the probability of periodontitis can be reduced by 6.0 % (stop smoking) and 0.6 % (stop drinking) on average. Conclusions: Data-driven models for predicting periodontitis and other periodontal parameters were developed from 16 risk factors, demonstrating enhanced prediction performance and reproducibility in internal-external validations.

11.
Spine J ; 24(5): 867-876, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38272128

RESUMO

BACKGROUND CONTEXT: Smoking cessation reduces the risk of vertebral and hip fractures but usually increases body weight. Since underweight is known as a risk factor for vertebral fractures, smoking cessation is considered to have a protective effect on vertebral fractures. However, the actual effect of weight change after smoking cessation on the risk of vertebral fractures remains uncertain. PURPPOSE: This study aimed to assess the risk of vertebral fractures among individuals who reported smoking cessation with a specific focus on changes in body weight. STUDY DESIGN: Retrospective cohort study based on nationwide health insurance database. PATIENT SAMPLE: Participants were from nationwide biennial health checkups between 2007 and 2009 conducted by the Korean National Health Insurance Service. Participants were followed up from 2010 to 2018 to find incidence of newly developed vertebral fractures. OUTCOME MEASURES: The incidence rate was defined as the incidence rate (IR) per 1,000 person-years (PY). Cox proportional regression analysis was used to analyze the risk of vertebral fracture to determine the hazard ratio (HR) associated with the incidence of vertebral fractures based on smoking status and weight changes. METHODS: Based on their self-reported questionnaires, the participants were classified into three groups: current smokers, quitters, and nonsmokers. The quitter was defined as an individual who were smokers in 2007 and ceased smoking in 2009. Individuals with smoking cessation were categorized according to the weight change between baseline and 2 years prior: weight maintenance (-5∼5 % of weight change), weight loss (<-5 % of weight change), and weight gain (>5 % of weight change). We used Cox proportional hazards analysis to determine the hazard ratio (HR) associated with the incidence of vertebral fractures based on smoking status and temporal weight change over 2 years. RESULTS: This study evaluated 913,805 eligible participants, of whom 672,858 were classified as nonsmokers, 34,143 as quitters, and 206,804 as current smokers. Among quitters, 2,372 (6.9%) individuals had weight loss, and 7,816 (22.9%) had weight gain over 2 years. About 23,952 (70.2%) individuals maintained their weight over 2 years. The overall risk of vertebral fractures was significantly higher in quitters (adjusted HR [aHR]=1.110, 95% confidence interval [CI] 1.013-1-216) than in nonsmokers, but it was lower than in current smokers (aHR=1.197, 95%CI 1.143-1.253), regardless of weight change after smoking cessation. However, individuals who experienced weight loss after smoking cessation exhibited a notably higher risk of vertebral fractures than current smokers (aHR=1.321, 95%CI 1.004-1.461). In the female population, weight gain after smoking cessation was associated with a higher risk of vertebral fractures (aHR = 1.470, 95%CI 1.002-2.587) than in current female smokers. CONCLUSIONS: Maintaining weight after smoking cessation may mitigate the risk of vertebral fractures. Weight loss after smoking cessation adversely affects the protective effects of smoking cessation on vertebral fractures in the general population.


Assuntos
Abandono do Hábito de Fumar , Fraturas da Coluna Vertebral , Humanos , Masculino , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/etiologia , Feminino , Pessoa de Meia-Idade , Abandono do Hábito de Fumar/estatística & dados numéricos , Adulto , Estudos Retrospectivos , Incidência , República da Coreia/epidemiologia , Fatores de Risco , Idoso , Aumento de Peso , Peso Corporal , Estudos de Coortes
12.
bioRxiv ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-39005313

RESUMO

Opioid overdose accounts for nearly 75,000 deaths per year in the United States, representing a leading cause of mortality amongst the prime working age population (25-54 years). At overdose levels, opioid-induced respiratory depression becomes fatal without timely administration of the rescue drug naloxone. Currently, overdose survival relies entirely on bystander intervention, requiring a nearby person to discover and identify the overdosed individual, and have immediate access to naloxone to administer. Government efforts have focused on providing naloxone in abundance but do not address the equally critical component for overdose rescue: a willing and informed bystander. To address this unmet need, we developed the Naloximeter: a class of life-saving implantable devices that autonomously detect and treat overdose, with the ability to simultaneously contact first-responders. We present three Naloximeter platforms, for both fundamental research and clinical translation, all equipped with optical sensors, drug delivery mechanisms, and a supporting ecosystem of technology to counteract opioid-induced respiratory depression. In small and large animal studies, the Naloximeter rescues from otherwise fatal opioid overdose within minutes. This work introduces life-changing, clinically translatable technologies that broadly benefit a susceptible population recovering from opioid use disorder.

13.
Dermatol Surg ; 39(3 Pt 1): 435-42, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23278870

RESUMO

BACKGROUND: Tranexamic acid (TA) has recently gained in popularity in the treatment of pigmentary disorders. OBJECTIVE: To evaluate the clinical efficacy and safety of oral TA combined with low-fluence 1064-nm quality-switched neodymium-doped yttrium aluminum garnet (QSNY) laser for the treatment of melasma. MATERIALS AND METHODS: Forty-eight patients with melasma were enrolled in the study and subsequently divided into two groups: a combination group and a laser treatment group. All patients were treated with two sessions of low-fluence QSNY laser, and patients in the combination group took 8 weeks of oral TA. Two blinded dermatologists evaluated patients using the Modified Melasma Area and Severity Index (mMASI) and a clinical improvement scale. RESULTS: Mean mMASI score 4 weeks after the second treatment decreased significantly in both groups from base line. Based on overall clinical improvement, a greater number of patients scored as grade 3 and more in the combination group; no patients were scored as grade 4 in the laser-alone group. CONCLUSIONS: Oral TA may prove a safe and efficient treatment option for melasma in combination with low-fluence QSNY laser therapy.


Assuntos
Antifibrinolíticos/administração & dosagem , Lasers de Estado Sólido/uso terapêutico , Melanoma/terapia , Neoplasias Cutâneas/terapia , Ácido Tranexâmico/administração & dosagem , Administração Oral , Adulto , Antifibrinolíticos/farmacologia , Povo Asiático , Terapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Ácido Tranexâmico/farmacologia
14.
Biochem Biophys Res Commun ; 427(4): 701-4, 2012 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-23022527

RESUMO

The D-galactose (D-gal)-induced animal model, which is established by consecutive subcutaneous d-gal injections for approximately 6weeks, has been frequently used for aging research. This animal model has been shown to accelerate aging of the brain, kidneys, liver, and blood cells. However, aging of the female reproductive organs in this animal model has not been reported. The aim of this study was to investigate changes in the ovary in the d-gal-induced aging mouse model. First, we evaluated anti-Müllerian hormone (AMH) as a marker of ovarian aging in blood plasma. We speculated there would be lower AMH levels in d-gal-treated mice because ovarian aging would be induced by d-gal, as reported for other tissues. However, the results showed that AMH levels in d-gal-treated mice were approximately four-fold higher than control mice. Abnormally high AMH levels are detected in ovarian cancer and polycystic ovary syndrome (PCOS) patients. Therefore, we examined PCOS-related markers in this mouse model. Total testosterone levels were high and abnormal estrous cycles were induced in d-gal-treated mice. These changes, including AMH levels, in d-gal-treated mice were inhibited by aminoguanidine treatment, an advanced glycation end product reducer. In addition, ovarian cysts were observed in some d-gal-treated mice. These results indicate that with respect to female reproduction, d-gal-treated mice are suitable for PCOS studies, rather than aging studies.


Assuntos
Envelhecimento/sangue , Hormônio Antimülleriano/sangue , Modelos Animais de Doenças , Camundongos , Síndrome do Ovário Policístico/sangue , Animais , Ciclo Estral/sangue , Ciclo Estral/efeitos dos fármacos , Ciclo Estral/fisiologia , Feminino , Galactose/farmacologia , Camundongos Endogâmicos ICR , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/patologia , Testosterona/sangue
15.
Nanomaterials (Basel) ; 12(13)2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35808135

RESUMO

In this work, WS2 was adopted as a channel material among transition metal dichalcogenides (TMD) materials that have recently been in the spotlight, and the circuit power performance (power consumption, operating frequency) of the monolayer WS2 field-effect transistor with a double gate structure (DG WS2-FET) was analyzed. It was confirmed that the effective capacitance, which is circuit power performance, was greatly changed by the extrinsic capacitance components of DG WS2-FET, and the spacer region length (LSPC) and dielectric constant (KSPC) values of the spacer that could affect the extrinsic capacitance components were analyzed to identify the circuit power performance. As a result, when LSPC is increased by 1.5 nm with the typical spacer material (KSPC = 7.5), increased operating speed (+4.9%) and reduced active power (-6.8%) are expected. In addition, it is expected that the spacer material improvement by developing the low-k spacer from KSPC = 7.5 to KSPC = 2 at typical LSPC = 8 nm can increase the operating speed by 36.8% while maintaining similar active power consumption. Considering back-end-of-line (BEOL), the change in circuit power performance according to wire length was also analyzed. From these results, it can be seen that reducing the capacitance components of the extrinsic region is very important for improving the circuit power performance of the DG WS2-FET.

16.
Bioresour Technol ; 366: 128205, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36341859

RESUMO

Promoting direct interspecies electron transfer (DIET) with conductive additives is considered a promising approach to enhance methanogenesis. This study investigated the effects of adding submicron magnetite particles on sludge granulation and methanogenic performance in upflow anaerobic sludge blanket reactors inoculated with flocculent sludge. The reactor supplemented with magnetite was more stable and resilient than the no-magnetite control, with higher degree of granulation (up to 26.6-fold) and biomass retention. Magnetite addition to unstable reactors improved the methane yield in both reactors (1.2-1.3-fold). Electroactive Deltaproteobacteria bacteria, including Geobacter and Syntrophobacter, were enriched in the presence of magnetite. Methanogenic functional genes involved in DIET-based syntrophy were more abundant under magnetite-supplemented conditions. However, the improvement of methanogenic performance and granulation was limited, and inducing the self-embedment of magnetite into mature sludge granules rather than granulating flocculent sludge with magnetite appears to be a better strategy for engineering DIET in anaerobic granular sludge systems.


Assuntos
Reatores Biológicos , Esgotos , Esgotos/microbiologia , Anaerobiose , Reatores Biológicos/microbiologia , Óxido Ferroso-Férrico , Metano , Eliminação de Resíduos Líquidos
17.
Pharmaceutics ; 14(11)2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36432671

RESUMO

L-α-Glycerylphosphorylcholine (L-α-GPC) has mainly been produced by two methods: extraction from plants rich in phosphatidylcholine and chemical synthesis. However, production through extraction involves difficult processes, such as fermentation, extractions and ripening, and conventional chemical synthesis methods with high-cost reactants and a batch reactor. These methods are not ideal for large-quantity production. Thus, it is important to develop a simple production method of L-α-GPC, which is suitable for mass production without the need for expensive reactants. Here, we studied synthetic L-α-GPC methods that are applicable to a flow synthesis system, which can provide selectivity, reproducibility, scalability, and a high yield in short reaction time using inexpensive starting materials. We developed a two-step synthetic route to produce L-α-GPC, including the synthesis of phosphoryl choline using choline chloride and phosphoryl oxychloride (POCl3) as a first step and synthesis of L-α-GPC by reacting phosphoryl choline with (R)-(-)-3-chloro-1,2-propanediol (CPD) as a second step under basic conditions. Both steps were separately performed in a customized flow reactor, and reaction conditions were optimized. Finally, phosphoryl choline and L-α-GPC, the products first and second reactions, were successfully synthesized with high conversion yields of 97% and 79%, respectively.

18.
Nanomicro Lett ; 14(1): 46, 2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35064848

RESUMO

The practical applications of aqueous Zn metal batteries are currently restricted by the inherent drawbacks of Zn such as the hydrogen evolution reaction, sluggish kinetics, and dendrite formation. To address these problems, herein, a limitedly Zn-doped MgF2 interphase comprising an upper region of pure, porous MgF2 and a lower region of gradient Zn-doped MgF2 is achieved via radio frequency sputtering technique. The porous MgF2 region is a polar insulator whose high corrosion resistance facilitates the de-solvation of the solvated Zn ions and suppression of hydrogen evolution, resulting in Zn metal electrodes with a low interfacial resistance. The Zn-doped MgF2 region facilitates fast transfer kinetics and homogeneous deposition of Zn ions owing to the interfacial polarization between the Zn dopant and MgF2 matrix, and the high concentration of the Zn dopant on the surface of the metal substrate as fine nuclei. Consequently, a symmetric cell incorporating the proposed Zn metal exhibits low overpotentials of ~ 27.2 and ~ 99.7 mV without Zn dendrites over 250 to 8000 cycles at current densities of 1.0 and 10.0 mA cm-2, respectively. The developed Zn/MnO2 full cell exhibits superior capacity retentions of 97.5% and 84.0% with average Coulombic efficiencies of 99.96% after 1000 and 3000 cycles, respectively.

19.
Materials (Basel) ; 15(21)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36363440

RESUMO

This study investigates the strength and permeability properties of pervious concrete-containing coal bottom ash (CBA) aggregates. Two pervious concrete mixtures were fabricated with different aggregate size distributions. One mixture contained CBA aggregates with a single-type distribution and the other mixture contained CBA aggregates with a hybrid-type distribution. The test parameters of the CBA pervious concrete included the water/cement (W/C) ratio and compaction level to investigate their effects on the properties. W/C ratios of 0.25, 0.30, and 0.35 were considered for the mixture, and compaction levels of 0.5, 1.5, and 3.0 MPa were applied to fabricate the pervious specimen. The increase in the W/C ratio reduced the strength by approximately 20% to 30% of the CBA pervious concrete. The increase in the compaction level reduced the permeability by approximately four to five times but significantly increased the strength of the CBA pervious concrete. The test results indicate that the use of single-type CBA or hybrid CBA aggregates with different size distributions affected the properties of the pervious concrete. The strength of specimens, including hybrid CBA aggregates, was 30% to 45% greater than that of the specimens containing single-type CBA aggregates. Meanwhile, the use of hybrid CBA aggregates reduced the permeability of the CBA pervious concrete by approximately 20% to 35%. Finally, relationships between the strength properties, permeability characteristics and total void ratios of the CBA pervious concrete specimens are suggested based on the test results.

20.
Nanomaterials (Basel) ; 12(21)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36364674

RESUMO

Femtosecond ultrafast-laser micro-patterning was employed to prepare a three-dimensional (3D) structure for the tape-casting Ni-rich LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode. The influences of laser structuring on the electrochemical performance of NMC811 were investigated. The 3D-NMC811 cathode retained capacities of 77.8% at 2 C of initial capacity at 0.1 C, which was thrice that of 2D-NMC811 with an initial capacity of 27.8%. Cyclic voltammetry (CV) and impedance spectroscopy demonstrated that the 3D electrode improved the Li+ ion transportation at the electrode-electrolyte interface, resulting in a higher rate capability. The diffusivity coefficient DLi+, calculated by both CV and electrochemical impedance spectroscopy, revealed that 3D-NMC811 delivered faster Li+ ion transportation with higher DLi+ than that of 2D-NMC811. The laser ablation of the active material also led to a lower charge-transfer resistance, which represented lower polarization and improved Li+ ion diffusivity.

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