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Solvent rinse treatments using polar methanol (MeOH) and nonpolar n-hexane have been developed for controlling material concentration gradients along the longitudinal direction of non-fullerene acceptor-based bulk heterojunction (BHJ) films comprised of electron donor polymer, PBDB-T and acceptor, ITIC-m. Before the used solvents (chlorobenzene with 1 vol.% DIO) were completely evaporated, ITIC-m rich domains were formed at the top surface of the BHJ films after they were rinsed with MeOH, as evidenced by water contact angle, atomic force microscopy, time-of-flight secondary ion mass spectroscopy, which led to enhanced electron transport in the conventional structure of organic solar cells (OSCs). In contrast, after rinsing with n-hexane, ITIC-m rich domains were formed at the bottom surface of the films, which improved electron transport in the inverted structure OSCs. The enhanced carrier transports increased the PCEs (11.80% and 11.15%) in both conventional and inverted OSCs by 10.29% and 10.35% compared with control devices. The versatile control of material concentration gradients is determined to be feasible owing to the chemical interaction of the used substrates (glass, PEDOT:PSS, and ZnO) and rinsing solvents.

This paper presents a high-performance radio frequency (RF) power amplifier (PA) module for which an optimum chip-level packaging structure is proposed to reduce the operating temperature of the RF PA monolithic microwave integrated circuit (MMIC). Because the output power (Pout) and the efficiency of a RF PA module are strongly affected by the thermal characteristics of the PA MMIC, various types of heat spreader materials and thermal interface materials have been examined to implement the PA chip-level packaging structure, and the optimum combination is proposed for a performance enhancement of the PA module in this paper. In addition, the optimum form-factor of the heat spreader was suggested based on a thermal simulation. To verify the proposed PA chip-level packaging structure, a 10 W 618 GHz RF PA MMIC using a commercial 0.25-m gallium nitride high electron mobility transistor process was designed and implemented for radar applications. The operating temperature of the PA MMIC on the proposed chip-level packaging structure shows a dramatic reduction of 24.8 C, and accordingly, the average Pout and average power-added efficiency are enhanced by up to 9.2% and 2.8%, respectively, when compared with a PA module using the conventional chip-level packaging structure.

Along with a wide range of applications, the surface-enhanced Raman spectroscopy (SERS) is a prominent analytical technique to recognize and detect molecules and materials even at an extremely low molar concentration. In this work, a unique hybrid SERS platform is demonstrated by the incorporation of molybdenum disulfate (MoS2) nanoparticles (NPs) onto the core-shell AuPt hybrid NPs (HNPs) for the enhanced molecular Raman vibration of crystal violet (CV). The hybrid platform takes the advantage of both the electromagnetic mechanism (EM) offered by the AuPt HNPs and chemical mechanism (CM) owing to the MoS2 NPs. The distinctive core-shell morphology of AuPt HNPs with the high-density background Au NPs is attained by a unique two-step solid-state dewetting method, which can offer a high concentration of electromagnetic hot spots. At the same time, the MoS2 NPs can provide an ample charge transfer with abundant active sites. Through the hybrid SERS approach, a dramatic SERS enhancement of CV Raman vibration is demonstrated, and the SERS capability is thoroughly studied. In addition, the finite-difference time-domain (FDTD) simulations provide a deeper understanding of the electromagnetic field distributions for various configurations of nanostructures and their hybrid combinations: i.e., HNPs, alloy NPs, MoS2/HNPs configurations.

The generation of hydrogen, free of poisonous gas, combined with a lightweight proton-exchange membrane fuel cell can expand the use of hydrogen energy from conventional ground transportation vehicles and power stations to a variety of flying vehicles and wearable devices for civilian and military purposes. Herein, a hydrogen fuel composite composed of sodium borohydride (SB) and oxalic acid dihydrate (OA·2H2O) is introduced. The SB/OA·2H2O composite was easily decomposed to generate pure hydrogen at a trigger temperature of 50 °C, at which the water molecules of the OA·2H2O component were effectively liberated, inducing hydrolysis of the SB component to produce hydrogen gas. This dry hydrolysis-based hydrogen generation using the SB/OA·2H2O composite has the merits of rapidly generating hydrogen (i.e., 0.4 g of the composite can be fully decomposed within a minute at low temperatures), free of poisonous gas, in approximately 5 wt % yield (the theoretical maximum value).

Objective In previous studies using Illumina Infinium methylation arrays, we have identified DNA methylation marks associated with cancer predisposition and progression. In the present study, we have sought to find appropriate technology to both technically validate our data and expand our understanding of DNA methylation in these genomic regions. Here, we aimed to assess the repeatability of methylation measures made using QIAseq targeted methyl panel and to compare them with those obtained from the Illumina HumanMethylation450 (HM450K) assay. We included in the analysis high molecular weight DNA extracted from whole blood (WB) and DNA extracted from formalin-fixed paraffin-embedded tissues (FFPE). Results The repeatability of QIAseq-methylation measures was assessed at 40 CpGs, using the Intraclass Correlation Coefficient (ICC). The mean ICCs and 95% confidence intervals (CI) were 0.72 (0.62–0.81), 0.59 (0.47–0.71) and 0.80 (0.73–0.88) for WB, FFPE and both sample types combined, respectively. For technical replicates measured using QIAseq and HM450K, the mean ICCs (95% CI) were 0.53 (0.39–0.68), 0.43 (0.31–0.56) and 0.70 (0.59–0.80), respectively. Bland–Altman plots indicated good agreement between QIAseq and HM450K measurements. These results demonstrate that the QIAseq targeted methyl panel produces reliable and reproducible methylation measurements across the 40 CpGs that were examined.

A new accepter unit, 2,3-didodecyl-6,7-difluoroquinoxaline, was prepared and utilized for the synthesis of electron acceptor–donor–acceptor materials for organic solar cells. 2,3-Didodecyl-6,7-difl...

InGaAs is a potential candidate for a next-generation channel material of complementary metal-oxide-semiconductor devices based on its excellent electron mobility. In this study, the surface behaviors of the InGaAs after treatments in H3PO4/H2O2/H2O and HNO3/H2O2/H2O mixtures were investigated and compared with that after treatment in a HCl/H2O2/H2O mixture. Although the presence of Cl− in an acidic solution suppressed the overall etching reaction and material loss of the InGaAs surface, Cl− induced the roughening of the InGaAs surface. The smallest InGaAs/Al2O3 interface charge trap density was observed when the InGaAs surface was prepared in the H3PO4/H2O2/H2O solution. It was also confirmed that the H3PO4/H2O2/H2O-treated InGaAs surface had the highest electron mobility among the samples and the lowest interfacial defect density, such as arsenic vacancies and antisites. Finally, it was concluded that surface preparation of InGaAs with H3PO4/H2O2/H2O effectively improved the interfacial electrical properties at the metal-oxide-InGaAs semiconductor by successfully minimizing surface roughening and the interfacial defect density compared to a well-known HCl/H2O2/H2O solution process.

Background Diffuse‐type gastric cancer (GC) is known to be more aggressive and relatively resistant to conventional chemotherapy. Hence, more optimized treatment strategy is urgently needed in diffuse‐type GC. Methods Using a panel of 10 GC cell lines and 3 GC patient‐derived cells (PDCs), we identified cell lines with high EMTness which is a distinct feature for diffuse‐type GC. We treated GC cells with high EMTness with ramucirumab alone, TGF‐β receptor kinase inhibitor (TEW‐7197) alone, or in combination to investigate the drug's effects on invasiveness, spheroid formation, EMT marker expression, and tumor‐induced angiogenesis using a spheroid‐on‐a‐chip model. Results Both TEW‐7197 and ramucirumab treatments profoundly decreased invasiveness of EMT‐high cell lines and PDCs. With a 3D tumor spheroid‐on‐a‐chip, we identified versatile influence of co‐treatment on cancer cell‐induced blood vessel formation as well as on EMT progression in tumor spheroids. The 3D tumor spheroid‐on‐a‐chip demonstrated that TEW‐7197 + ramucirumab combination significantly decreased PDC‐induced vessel formation. Conclusions In this study, we showed TEW‐7197 and ramucirumab considerably decreased invasiveness, thus EMTness in a panel of diffuse‐type GC cell lines including GC PDCs. Taken together, we confirmed that combination of TEW‐7197 and ramucirumab reduced tumor spheroid and GC PDC‐induced blood vessel formation concomitantly in the spheroid‐on‐a‐chip model., Diffuse‐type gastric cancer (GC) is known to be more aggressive and relatively resistant to conventional chemotherapy. In this study, we sought a drug candidate for this type of cancer treatment and confirmed that combination of TEW‐7197 and ramucirumab reduced tumor spheroid invasiveness and GC PDC‐induced blood vessel formation concomitantly in the spheroid‐on‐a‐chip model.

Cooling technology exploiting the endothermic reaction of fuel has been developed to prevent structural deformation in engines due to air friction and overheating during supersonic flight. Endothermic fuels are liquid hydrocarbon fuels that can absorb heat through endothermic reactions. The initial heat sink capacity of conventional pellet type catalysts for the endothermic reaction cannot be maintained, leading to more rapid deactivation due to coke formation. To maintain the heat sink performance of decomposition catalysts, HZSM-5 catalyst washcoated on metal foam(HZSM-5/metal foam) was used herein. The reactions were carried out in a batch reactor at 673 K at a pressure of 50 bar using methylcyclohexane (MCH) and n-dodecane as reactants. The total MCH conversion achieved with the pellets and HZSM-5/metal foam was same at 93 %. In the case of n-dodecane, the total conversion achieved with the HZSM-5/metal foam (91 %) was superior to that achieved with the pellets (69 %).

Lithium–sulfur batteries are one of the attractive next-generation energy storage systems owing to their environmental friendliness, low cost, and high specific energy densities. However, the low electrical conductivity of sulfur, shuttling of soluble intermediate polysulfides between electrodes, and low capacity retention have hampered their commercial use. To address these issues, we use a halloysite-modulated (H-M) separator in a lithium–sulfur battery to mitigate the shuttling problem. The H-M separator acts as a mutual Coulombic repulsion in lithium-sulfur batteries, thereby selectively permitting Li ions and efficiently suppressing the transfer of undesired lithium polysulfides to the Li anode side. Moreover, the use of halloysite switches the surface of the separator from hydrophobic to hydrophilic, consequently improving the electrolyte wettability and adhesion between the separator and cathode. When sulfur-multi-walled carbon nanotube (S-MWCNT) composites are used as cathode active materials, a lithium–sulfur battery with an H-M separator exhibits first discharge and charge capacities of 1587 and 1527 mAh g−1, respectively. Moreover, there is a consistent capacity retention up to 100 cycles. Accordingly, our approach demonstrates an economical and easily accessible strategy for commercialization of lithium–sulfur batteries.

The Virus BioResistor (VBR) is a biosensor capable of the rapid and sensitive detection of small protein disease markers using a simple dip-and-read modality. For example, the bladder cancer-associated protein DJ-1 (22 kDa) can be detected in human urine within 1.0 min. with a limit-of-detection (LOD) of 10 pM. The VBR uses engineered virus particles as receptors to recognize and selectively bind the protein of interest. These virus particles are entrained in a conductive poly(3,4 ethylenedioxythiophene) or PEDOT channel. The electrical impedance of the channel increases when the target protein is bound by the virus particles. But VBRs exhibit a sensitivity that is inversely related to the molecular weight of the protein target. Thus, large proteins, such as IgG antibodies (150 kDa), can be undetectable even at high concentrations. We demonstrate that the electrochemical over-oxidation of the VBR’s PEDOT channel increases its electrical impedance, conferring enhanced sensitivity for both small and large proteins. Over-oxidation makes possible the detection of two an antibody, undetectable at a normal VBR, with a limit-of-detection of 40 ng/mL (250 pM), and a dynamic range for quantitation extending to 600 ng/mL.

This paper proposes a discrete-time preview-feedback controller capable of reducing nitrogen oxide (NOx) emissions with affordably low ammonia (NH3) slip downstream of a catalyst for selective catalytic reduction (SCR) systems. Because of the high NOx reduction rate, SCR systems are increasingly adopted in diesel engines. However, slow dynamics of the SCR system along with a time delay in the sensor result in a challenging control problem. To overcome the control challenges, the preview-feedback controller is proposed under the assumption that the NOx disturbance is previewed. To design the preview-feedback H∞ controller, a discrete-time generalized plant is derived by combining the linearized model of SCR system, the model for previewing disturbance signal, and the weighting function. Based on experimentally obtained data, the simulations show that the proposed controller can effectively reduce 34 % of NOx emissions and 6 % of NH3 slip more, compared to a non-preview controller. The robustness is then demonstrated using the uncertainties ranging from 10 to 40 %. This result shows that uncertainties of up to 30 % do not negatively affect the performance. Additionally, the result for the computational requirement shows that the proposed controller yields better performance with lower computation time than a model predictive controller does.

Advanced beyond-silicon electronic technology requires both channel materials and also ultralow-resistance contacts to be discovered1,2. Atomically thin two-dimensional semiconductors have great potential for realizing high-performance electronic devices1,3. However, owing to metal-induced gap states (MIGS)4–7, energy barriers at the metal–semiconductor interface—which fundamentally lead to high contact resistance and poor current-delivery capability—have constrained the improvement of two-dimensional semiconductor transistors so far2,8,9. Here we report ohmic contact between semimetallic bismuth and semiconducting monolayer transition metal dichalcogenides (TMDs) where the MIGS are sufficiently suppressed and degenerate states in the TMD are spontaneously formed in contact with bismuth. Through this approach, we achieve zero Schottky barrier height, a contact resistance of 123 ohm micrometres and an on-state current density of 1,135 microamps per micrometre on monolayer MoS2; these two values are, to the best of our knowledge, the lowest and highest yet recorded, respectively. We also demonstrate that excellent ohmic contacts can be formed on various monolayer semiconductors, including MoS2, WS2 and WSe2. Our reported contact resistances are a substantial improvement for two-dimensional semiconductors, and approach the quantum limit. This technology unveils the potential of high-performance monolayer transistors that are on par with state-of-the-art three-dimensional semiconductors, enabling further device downscaling and extending Moore’s law. Electric contacts of semimetallic bismuth on monolayer semiconductors are shown to suppress metal-induced gap states and thus have very low contact resistance and a zero Schottky barrier height.

Molybdenum disulfide (MoS2) has been regarded as one of the most important n-type two-dimensional (2D) transition metal dichalcogenide semiconductors for nanoscale electron devices. Relatively high contact resistance (RC) remains as an issue in the 2D-devices yet to be resolved. Reliable technique is very compelling to practically produce low RC values in device electronics, although scientific approaches have been made to obtain a record-low RC. To resolve this practical issue, we here use thermal-evaporated ultrathin LiF between channel and source/drain metal to fabricate 2D-like MoS2 field effect transistors (FETs) with minimum RC. Under 4-bar FET method, RC less than ∼600 Ω·μm is achieved from the LiF/Au contact MoS2 FET. Our normal 2-bar FET with LiF thus shows the same mobility as that of 4-bar FET that should have no RC in principle. On the basis of these results, ultrathin LiF is also applied for transparent conducting oxide contact, successfully enabling transparent MoS2 FETs.

The effect of chemical-composition modification on the chiroptical property of chiral organic ammonium cation-containing organic inorganic hybrid perovskite (chiral OIHP) is investigated. Varying the mixing ratio of bromide and iodide anions in S- or R-C6H5CH2(CH3)NH3)2PbI4(1-x)Br4x modifies the band gap of chiral OIHP, leading to a shift of the circular dichroism (CD) signal from 495 to 474 nm. However, it is also found that an abrupt crystalline structure transition occurs, and the CD signal is turned off when iodide-determinant phases are transformed into the bromide-determinant phase. To obtain CD in the wavelength range where the bromide-determinant phase is supposed to exhibit chiroptical activity, that is

Comparative genomic analysis was performed on eight species of lactic acid bacteria (LAB)-Lactococcus (L.) lactis, Lactobacillus (Lb.) plantarum, Lb. casei, Lb. brevis, Leuconostoc (Leu.) mesenteroides, Lb. fermentum, Lb. buchneri, and Lb. curvatus-to assess their glutamic acid production pathways. Glutamic acid is important for umami taste in foods. The only genes for glutamic acid production identified in the eight LAB were for conversion from glutamine in L. lactis and Leu. mesenteroides, and from glucose via citrate in L. lactis. Thus, L. lactis was considered to be potentially the best of the species for glutamic acid production. By biochemical analyses, L. lactis HY7803 was selected for glutamic acid production from among 17 L. lactis strains. Strain HY7803 produced 83.16 pmol/μl glutamic acid from glucose, and exogenous supplementation of citrate increased this to 108.42 pmol/μl. Including glutamic acid, strain HY7803 produced more of 10 free amino acids than L. lactis reference strains IL1403 and ATCC 7962 in the presence of exogenous citrate. The differences in the amino acid profiles of the strains were illuminated by principal component analysis. Our results indicate that L. lactis HY7803 may be a good starter strain for glutamic acid production.

Bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) is the most common cause of lower urinary tract symptoms (LUTS) in older men. Although medical treatments can reduce BPH-related LUTS and even prevent invasive treatments, at least one in five men who complain of LUTS due to BPH will eventually need surgery. Of LUTS, storage symptoms persist in 20 to 40% of patients even after the obstruction is resolved. The present study aims to investigate the predisposing factors of the persistent storage symptoms after HoLEP in patients with BPH and their correlations to the recovery time of the symptoms. A total of 127 patients with complaints of storage symptoms and who underwent transurethral HoLEP surgery at Pusan National University Hospital from May 2014 to June 2017 were included in this study. Urodynamic studies were performed in all patients, and BOO was confirmed by urodynamic studies before HoLEP. All patients were asked to complete the IPSS (also known as the American Urological Association score) and the Overactive Bladder Symptom Score (OABSS) questionnaire to evaluate LUTS on the day before HoLEP and 3 months after HoLEP. Patients were divided into group I, which included patients with persistent storage symptoms after HoLEP, and group II, which included patients without storage symptoms after HoLEP. Of a total of 127 patients, 68 were included in group I, and the remaining 59 were included in group II. In the univariable analysis, group I showed statistically significantly older mean age, higher mean peak detrusor pressure during filling cystometry, and lower mean MCC than group II. Multivariate analysis of these three variables showed that only mean age and mean peak detrusor pressure during filling cystometry had statistically significant differences. In group I, 12 patients had storage symptoms until 12 months after surgery. When comparing these patients with the remaining 56 patients, only mean age showed statistically significant differences. Old age and high peak detrusor pressure during filling cystometry were the predictors of persistent storage symptoms after HoLEP. Furthermore, older patients were unlikely to recover storage symptoms until 12 months after operation.

Indium gallium arsenide (InGaAs) is one of the candidate materials to overcome the physical limitation of Si due to its excellent electrical properties. The effect of surface oxidation on the etching characteristics of InGaAs surface in acidic solutions were investigated. InGaAs surfaces was etched in HCl/H2O2/H2O (CPM) and HNO3/H2O2/H2O (NPM), while there was no thickness change in diluted HCl or HNO3. The CPM-treated InGaAs surface had a lower etching rate than the NPM-treated one, while etching rate of oxidized layer was higher in diluted HCl than in HNO3. NaCl added in the NPM acts as an etching inhibitor for InGaAs and the etching rate was significantly suppressed. It is thought that Cl− anion inhibits the formation of hydroxyl radical (OH∙) or consumes OH∙ in acidic solution, inhibiting surface oxidation of InGaAs and suppressing its material loss.

Conformal integration of an epidermal device with the skin, as well as sweat and air permeability, are crucial to reduce stress on biological tissues. Nanofiber-based porous mesh structures (breathable devices) are commonly utilized to prevent skin problems. Noble metals are normally deposited on nanomesh substrates to form breathable electrodes. However, these are expensive and require high-vacuum processes involving time-consuming multistep procedures. Organic materials are suitable alternatives that can be simply processed in solution. We report a simple, cost-effective, mechanically biocompatible, and breathable organic epidermal electrode for biometric devices. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is sprayed on a nanofiber-mesh structure, treated using only heat and water to enhance its biocompatibility and conductivity, and used as the electrode. The treatment is accomplished using an autoclave, simultaneously reducing the electrical resistance and sterilizing the electrode for practical use. This research can lead to affordable and biocompatible epidermal electrodes with improved suitability for various biomedical applications.

A real-time kinase assay method based on a ratiometric fluorescence probe that can be applied to various small-molecule kinases is described herein. The probe can trace the reversible interchange of ATP and ADP, which is a common phenomenon in most small-molecule kinase reactions, by a ratiometric fluorescence change. This property facilitates the monitoring of phosphorylation and dephosphorylation in small-molecule kinases, whereas most of the existing methods focus on one of these reactions. To prove the applicability of this method for small-molecule kinase assays, hexokinase and creatine kinase, which phosphorylate and dephosphorylate substrates, respectively, were analyzed. The ratiometric fluorescence change was correlated with the enzyme activity, and the inhibition efficiencies of the well-known inhibitors, N-benzoyl-D-glucosamine and iodoacetamide, were also monitored. Notably, the change in fluorescence can be observed with a simple light source by the naked eye.

The oxygen evolution reaction (OER) is the key reaction in water splitting systems, but compared with the hydrogen evolution reaction (HER), the OER exhibits slow reaction kinetics. In this work, boron doping into nickel–iron layered double hydroxide (NiFe LDH) was evaluated for the enhancement of OER electrocatalytic activity. To fabricate boron-doped NiFe LDH (B:NiFe LDH), gaseous boronization, a gas–solid reaction between boron gas and NiFe LDH, was conducted at a relatively low temperature. Subsequently, catalyst activation was performed through electrochemical oxidation for maximization of boron doping and improved OER performance. As a result, it was possible to obtain a remarkably reduced overpotential of 229 mV at 10 mA cm−2 compared to that of pristine NiFe LDH (315 mV) due to the effect of facile charge-transfer resistance by boron doping and improved active sites by electrochemical oxidation.

Although considerable studies have focused on suppressing polysulfide shuttling in lithium–sulfur (Li–S) batteries by modifying separator surfaces, simultaneously achieving fast Li-ion transport and full active-material use remains a technological limitation. Herein, we present an effective method for anchoring zwitterionic sulfobetaine (SB) moieties on a separator surface that concurrently facilitates both selective Li-ion transport and polysulfide conversion. The platform that anchors the zwitterions was sequentially constructed by first introducing a polydopamine (PDA) coating to promote surface wettability and activity for further covalent SB binding using the aza-Michael addition reaction, which enabled the formation of a robust PDA/SB-coated separator. The zwitterion-functionalized separator exhibited a significant enhancement in ionic conductivity from 0.837 to 1.827 mS cm−1 and the Li-ion transference number from 0.186 to 0.511 due to the facile dissociation of lithium salts and selectively promoted the interactions between Li cations and the anionic sulfonate SB end groups. Along with the redox promoting effect, the polysulfide shuttling was further inhibited through strong dipole–dipole interactions. Furthermore, as Li2S precipitation was effectively mediated by the SB zwitterions and improved sulfur-conversion kinetics was achieved, outstanding Li–S battery performance with an initial discharge capacity of 1365.9 mA h g−1 was obtained, while delivering an ultra-low capacity decay rate of 0.034% during long-term cycling (up to 1200 cycles) at 3.0C, even at a high load. Therefore, we believe that the proposed study harnessing zwitterionic separator functionalization would enable the rational design of functional separators for the promoted kinetics and suppressed diffusion of unfavorable reaction intermediates for high performance batteries.

A ratiometric and selective hydrogen sulfide (H2S) detection probe was proposed based on the pyrene-DPA–Cd2+ complex through the metal ion displacement approach (MDA) mechanism. While most MDA-based fluorescence probes with paramagnetic Cu2+ have focused on the development of a simple turn-on sensor using the broad spectral range of fluorescence enhancement, this ratiometric probe exhibited unchanged monomer emission as a built-in internal reference with an increase in excimer emission with added H2S. The demonstrated probe showed a rapid response (within 1 min) and a high sensitivity, with 70 nM as the limit of detection. The selectivity for H2S over cysteine, homocysteine and glutathione was confirmed, and reliable fluorescence enhancement, which could be monitored by the naked eye, was observed upon irradiation with handheld UV light. In addition, this detection system was successfully applied to detect H2S in human serum without interference from biological molecules.

A biodegradable poly(lactide) (PLA) plasticizer system derived from renewable feedstocks was deliberately designed with an ester structure identical to as many repeating units of the PLA matrix as possible for maximized compatibility, using two solvent-free one-pot synthetic routes, resulting in elastomeric performance as well as tunable plasticization. First, hydroxyl-ended lactide oligomers were precisely prepared with target molar mass values of 330–430 g mol−1 by controlled bulk ring opening oligomerization using 1-, 2-, and 3-arm initiators. They were subsequently esterificated with acetic anhydride to produce acetyl-terminated lactide oligomers (ALO) with enhanced thermal stability. Td,5% was increased by 23–43 °C and efficient biodegradation of 78–55% was achieved. The ALO series was added as plasticizers to PLA from 10 to 50 phr (9–33 wt%), and showed the ability to lower Tg,PLA to approximately 10–20 °C in DSC analysis and complete miscibility with PLA, as confirmed by visible or UV-vis transmittance, and SEM studies. The ALO had little contribution to changes in the PLA structure on SEC traces after the thermo-mixing process. The blends exhibited reasonable migration level, and controllable mechanical characteristics with ductile-to-elastomeric properties (E′ = 889–15 MPa, σy = 74–7 MPa, σb = 69–9 MPa, and eb = 13–658%), when compared to those of PLA. Interesting elastomeric behaviors were observed and then evidenced by stress relaxation moduli (2.4–9.8 MPa) and small residual strains (7–17%) after recovery tests, respectively. These results suggest that the ALO series can be practical “double green” and “dual performance” plasticizers for PLA.

Herein, nanoporous Al2O3, CeO2, TiO2, ZrO2, and SnO2 were used as the supports for Pd nanoparticles, and effects of surface characteristics on catalytic performances for dehydrogenation of 2-[(n-me...

Freestanding graphene on a trench has been fabricated extensively using a transfer process of chemical vapor deposition grown graphene. Here, we demonstrate that freestanding graphene can be grown directly on a trench without a transfer process. A shallow trench was made on a 6H–SiC(0001) wafer using a focused ion beam lithography. The shallow trench was heated to a high temperature under Ar atmosphere. The heat treatment made the shallow trench become deeper and wider. Subsequently, epitaxial graphene was floating on the trench, resulting in freestanding graphene, where underlying bulk SiC was self-etched after the growth of epitaxial graphene. The freestanding graphene on a trench was characterized using Raman spectroscopy and atomic force microscopy. Such freestanding graphene writing can be applied to semiconductor fabrication process of freestanding graphene devices without a transfer process.

A photcatalyst-free photoredox synthesis of diaryl selenides has been developed by coupling reaction of diselenides with aryldiazo sulfones. The reaction was accelerated under visible light irradia...

Selective inhibition of microRNAs (miRNAs) offers a new avenue for cancer therapeutics. While most of the current anti-miRNA (antimiR) reagents target full length miRNAs, here we investigate novel nanoparticle-delivered short PNA probes containing cationic domains targeting the seed region of the miRNA for effective antimiR therapy. For proof of concept, we tested PNAs targeting miRNA-155 and employed poly(lactic-co-glycolic acid) (PLGA)-based nanoparticle formulation for delivery. A comprehensive evaluation of PLGA nanoparticles (NPs) containing short PNA probes showed significantly superior loading, release profile, and uniform size distribution, compared to conventional non-cationic PNA probes. Confocal microscopy and flow cytometry analyses showed efficient transfection efficiency and uniform distribution of PLGA NPs containing short PNA probes in the cytoplasm. Functional analysis also confirmed efficient miRNA-155 inhibition including an effect on its downstream target proteins. Further, reduced tumor growth was observed after systemic delivery of PLGA nanoparticles containing short PNA probes in vivo in a xenograft mouse model following inhibition of miR-155. There was no evidence of acute or chronic toxicity associated with systemic delivery of PLGA NPs containing short PNA probes in the mice. Overall, in this paper we present a novel antimiR strategy based on PLGA nanoparticle delivered short PNA probes for potential cancer therapy.

Organic-inorganic hybrid perovskite nanocrystals have attracted a lot of attention owing to their excellent optical properties such as high absorption coefficient, high diffusion length, and photoluminescence quantum yield in optoelectronic applications. Despite the many advantages of optoelectronic materials, understanding on how these materials interact with their environments is still lacking. In this study, the fluorescence properties of methylammonium lead bromide (CH3NH3PbBr3, MAPbBr3) nanoparticles are investigated for the detection of volatile organic compounds (VOCs) and aliphatic amines (monoethylamine, diethylamine, and trimethylamine). In particular, colloidal MAPbBr3 nanoparticles demonstrate a high selectivity in response to diethylamine, in which a significant photoluminescence (PL) quenching (~ 100%) is observed at a concentration of 100 ppm. This selectivity to the aliphatic amines may originate from the relative size of the amine molecules that must be accommodated in the perovskite crystals structure with a narrow range of tolerance factor. Sensitive PL response of MAPbBr3 nanocrystals suggests a simple and effective strategy for colorimetric and fluorescence sensing of aliphatic amines in organic solution phase.

Corynebacterium glutamicum, an important industrial strain, has a relatively slower reproduction rate. To acquire a growth-boosted C. glutamicum, a descendant strain was isolated from a continuous culture after 600 generations. The isolated descendant C. glutamicum, JH41 strain, was able to double 58% faster (td=1.15 h) than the parental type strain (PT, td=1.82 h). To understand the factors boosting reproduction, the transcriptomes of JH41 and PT strains were compared. The mRNAs involved in respiration and TCA cycle were upregulated. The intracellular ATP of the JH41 strain was 50% greater than the PT strain. The upregulation of NCgl1610 operon (a putative dyp-type heme peroxidase, a putative copper chaperone, and a putative copper importer) that presumed to role in the assembly and redox control of cytochrome c oxidase was found in the JH41 transcriptome. Plasmid-driven expression of the operon enabled the PT strain to double 19% faster (td=1.82 h) than its control (td=2.17 h) with 14% greater activity of cytochrome c oxidase and 27% greater intracellular ATP under the oxidative stress conditions. Upregulations of genes those might enhance translation fitness were also found in the JH41 transcriptome. Plasmid-driven expressions of NCgl0171 (encoding a cold-shock protein) and NCgl2435 (encoding a putative peptidyl-tRNA hydrolase) enabled the PT to double 22% and 32% faster than its control, respectively (empty vector: td=1.93 h, CspA: td=1.58 h, and Pth: td=1.44 h). Based on the results, the factors boosting growth rate in C. gluctamicum were further discussed in the viewpoints of cellular energy state, oxidative stress management, and translation.

The patterning of polydimethylsiloxane (PDMS) into complex two-dimensional (2D) or 3D shapes is a crucial step for diverse applications based on soft lithography. Nevertheless, mould replication that incorporates time-consuming and costly photolithography processes still remains the dominant technology in the field. Here we developed monolithic quasi-3D digital patterning of PDMS using laser pyrolysis. In contrast with conventional burning or laser ablation of transparent PDMS, which yields poor surface properties, our successive laser pyrolysis technique converts PDMS into easily removable silicon carbide via consecutive photothermal pyrolysis guided by a continuous-wave laser. We obtained high-quality 2D or 3D PDMS structures with complex patterning starting from a PDMS monolith in a remarkably low prototyping time (less than one hour). Moreover, we developed distinct microfluidic devices with elaborated channel architectures and a customizable organ-on-a-chip device using this approach, which showcases the potential of the successive laser pyrolysis technique for the fabrication of devices for several technological applications. A laser-based patterning method enables the fast fabrication of high-quality two- and three-dimensional features in polydimethylsiloxane for microfluidics and biomedical applications.

This study investigates enhanced oil recovery (EOR) and CO2 storage efficiencies during low-salinity carbonate waterflooding (LSCWF) in carbonate reservoirs containing “acid” formation water. In order to identify the detailed geochemical reactions for acidic condition during LSCWF, simulational analysis was performed with “CMG-GEM”. After core-scaled model was constructed through history-matching processes based on the coreflooding experimental results, primary mechanisms during LSCWF were analyzed for various levels of injection water salinity. From the results of this study, CO2 dissolved in injected carbonate water yielded CaCO3 precipitation in acidic reservoirs, decreasing permeability significantly compared to in neutral reservoirs. In terms of wettability alteration and oil swelling by CO2 mass transfer, their effects were almost similar regardless of the salinity for both acid and neutral reservoirs. In the aspects of EOR and CO2 storage efficiencies, they strongly depend on the salinity for both acidic and neutral conditions. In the results of EOR–CO2 storage relationship, enhanced oil was smaller in acidic condition, while CO2 storage efficiency was not greatly related to acidity of the reservoir. The findings of this study can help for better understanding of smart water injection design into acid carbonate reservoir for the optimal EOR and CO2 storage efficiencies.

Acetylated malic acid alkyl esters (AcMAE-Cn) with different alkyl chain lengths, as alternative plasticizers for both poly(vinyl chloride) (PVC) and poly(lactic acid) (PLA), were synthesized by the esterification of renewable malic acid with alcohols and subsequent acetylation. The molecular structure of the synthesized plasticizers was confirmed using 1H NMR and FT-IR spectroscopy. PVC or PLA blends containing 50 phr of the plasticizers were evaluated by dynamic mechanical analysis (DMA), tensile testing, and migration testing to evaluate the plasticization efficiency. The plasticized PVC films presented good plasticizing performance, as demonstrated by the results of tensile and migration testing and the Tg values (as determined by DMA). Among the plasticizers, AcMAE-C6 and AcMAE-C8 presented enhanced plasticizing performance compared with that of the commercial dioctyl adipate (DOA) and di(2-ethylhexyl) phthalate (DEHP) plasticizers. Additionally, the plasticizing properties of the plasticized PLA films depend significantly on the structure of the plasticizers. It was found that plasticizers (AcMAE-C4 and AcMAE-C6) bearing short alkyl groups (n-butyl and n-hexyl, respectively) may act as excellent plasticizers. In summary, the AcMAE-C6 plasticizer showed potential as an alternative plasticizer for both PVC and PLA polymers.

Thermal dehydrogenation of ammonia borane (AB) is one of the simplest methods to generate pure hydrogen for hydrogen power-driven proton exchange membrane fuel cells. For AB thermolysis, it is imperative to develop a highly effective catalyst to initiate the dehydrogenation reaction at a low temperature and eventually achieve enhanced hydrogen production. Here, we introduce a specifically designed AB-SiO2 nanocomposite, which is prepared by simple mixing and pressing processes. Hydrogen evolution during thermolysis of the cotton-structured AB-SiO2 composite is initiated at around 80 °C, and the maximum H2 yield is determined to be 11.2 wt% (2.32 mole equivalents of H2). The yield is found to depend on the size and size distribution of the catalytic SiO2 particles in the hydrogen fuel composite.

In this work, environmentally friendly photocatalysts with attractive catalytic properties are reported that have been prepared by introducing SnO2 quantum dots (QDs) directly onto ZnSe(N2 H4 )0.5 substrates to induce advantageous charge separation. The SnO2 /ZnSe(N2 H4 )0.5 nanocomposites could be easily synthesized through a one-pot hydrothermal process. Owing to the absence of capping ligands, the attached SnO2 QDs displayed superior photocatalytic properties, generating many exposed reactive surfaces. Moreover, the addition of a specified amount of SnO2 boosted the visible-light photocatalytic activity; however, the presence of excess SnO2 QDs in the substrate resulted in aggregation and deteriorated the performance. The spectroscopic data revealed that the SnO2 QDs act as a photocatalytic mediator and enhance the charge separation within the type II band alignment system of the SnO2 /ZnSe(N2 H4 )0.5 heterojunction photocatalysts. The separated charges in the heterojunction nanocomposites promote radical generation and react with pollutants, resulting in enhanced photocatalytic performance.

We designed and synthesized two novel low band gap small molecule donors (M1 and M2) that consist of benzo[1,2-b:4,5-b′]dithiophene as the electron-rich core and 6,7-difluoroquinoxaline as the elec...

The synthesis of more efficient, elementally abundant, and stable electrocatalysts for electrochemical hydrogen generation through water splitting is a critical task to provide affordable clean ene...

Pyruvate dehydrogenase kinase (PDK) controls the activity of pyruvate decarboxylase complex (PDC) by phosphorylating key serine residues on the E1 subunit, which leads to a decreased oxidative phosphorylation in mitochondria. Inhibition of PDK activity by natural/synthetic compounds has been shown to reverse the Warburg effect, a characteristic metabolism in cancer cells. PDK-PDC axis also has been associated with diabetes and heart disease. Therefore, regulation of PDK activity has been considered as a promising strategy to treat related diseases. Here we present the X-ray crystal structure of PDK2 complexed with a recently identified PDK4 inhibitor, compound 8c, which has been predicted to bind at the lipoyl-binding site and interrupt intermolecular interactions with the E2-E3bp subunits of PDC. The co-crystal structure confirmed the specific binding location of compound 8c and revealed the remote conformational change in the ATP-binding pocket. In addition, two novel 4,5-diarylisoxazole derivatives, GM10030 and GM67520, were synthesized and used for structural studies, which target the ATP-binding site of PDK2. These compounds bind to PDK2 with a sub-100nM affinity as determined by isothermal titration calorimetry experiments. Notably, the crystal structure of the PDK2-GM10030 complex displays unprecedented asymmetric conformation of human PDK2 dimer, especially in the ATP-lids and C-terminal tails.

A mechanically adjustable reinforced thermoplastic superelastomer system, with tunable gas-permeability, was developed. The superelastomer is based on a graft copolymer structure, using commercial ...

In this study, a consecutive doping method was used to improve the electrochemical properties of a commercial activated carbon (YP50f) as an electrode material for organic electric double-layer capacitors (EDLCs). In the consecutive doping method, nitrogen doping is carried out after an oxygen-doping process. Using the consecutive doping method, we prepared a carbon material with both a large specific surface area and high electrical conductivity. The specific surface area of the carbon material was mainly developed during the oxygen-doping step, whereas electrical conductivity was enhanced in the nitrogen-doping step. On the basis of the properties of the consecutively doped carbon material, we expected the prepared carbon material to exhibit good electrochemical properties when used as electrode materials for organic EDLCs. From the results of electrochemical characterizations, we observed that the consecutively doped carbon material showed a highly improved capacitance compared to the YP50f under all of the applied charge–discharge rates. Consequently, we concluded that the consecutive doping method is an effective method to prepare carbon materials with good electrochemical properties as electrode materials for organic EDLCs as a result of both their enhanced specific surface area and their enhanced electrical conductivity.

Nanorod diffusion in polymer melts is faster than predicted by the continuum model (CM). Rutherford backscattering spectrometry is used to measure the concentration profile of titanium dioxide (TiO2) nanorods (L = 43 nm, d = 5 nm) in a polystyrene (PS) matrix having molecular weights (M) from 9 to 2000 kDa. In the entangled regime, the tracer diffusion coefficients (D) of TiO2 decrease as the M–1.4, whereas the CM predicts DCM ∼ M–3.0 using the measured zero-shear viscosity of TiO2(1 vol %): PS(M) blends. By plotting D/DCM versus M/Me, where Me is the entanglement molecular weight, diffusion is enhanced by a factor of 10–103 as M/Me increases. The faster diffusion is attributed to decoupling of nanorod diffusion from polymer relaxations in the surrounding matrix, which is facilitated by the nanorod dimensions (i.e., L greater than and d less than the entanglement mesh size, 8 nm).

We numerically demonstrated single-port coherent perfect loss (CPL) with a Fabry–Perot resonator in a photonic crystal (PC) nanobeam by using a perfect magnetic conductor (PMC)-like boundary. The CPL mode with even symmetry can be reduced to a single-port CPL when a PMC boundary is applied. The boundary which acts like a PMC boundary, here known as a PMC-like boundary, and can be realized by adjusting the phase shift of the reflection from the PC when the wavelength of the light is within the photonic bandgap wavelength range. We designed and optimized simple Fabry–Perot resonator and coupler in nanobeam to get the PMC-like boundary. To satisfy the loss condition in CPL, we controlled the coupling loss in the resonator by modifying the lattice constant of the PC used for coupling. By optimizing the coupling loss, we achieved zero reflection (CPL) in a single port with a PMC-like boundary.