Search

Anticancer treatment is performed in various ways, and photothermal therapy (PTT) is gaining traction from a noninvasive treatment perspective. PTT is a treatment technique based on the photothermal effect that kills tumors by increasing their temperature. In this study, gold nanoparticles (AuNPs), which are photothermal agents, were used in numerical simulations to determine the PTT effect by considering diffusion induced changes in the distribution area of the AuNPs. The treatment effect was confirmed by varying the initial injection radius of AuNPs represented by the injection volume, the elapsed time after injection of AuNPs, and the laser intensity. The degree of maintenance of the apoptotic temperature band in the tumor was quantitatively analyzed by the apoptotic variable. Ultimately, if the initial injection radius of AuNPs is 0.7 mm or less, the optimal time to start treatment is 240 min after injection, and for 1.0 and 1.2 mm, it is optimal to start treatment when the elapsed time after injection is 90 and 30 min, respectively. This study identified the optimal treatment conditions for dosage of AuNPs and treatment start time in PTT using AuNPs, which will serve as a reference point for future PTT studies. [ABSTRACT FROM AUTHOR]

Recent advances in technology have led to an increase in the detection of previously undetected deep-located tumor tissue. As a result, the medical field is using a variety of methods to treat deep-located tumors, and minimally invasive treatment techniques are being explored. In this study, therapeutic effect of microwave ablation (MWA) on tumor generated inside liver tissue was analyzed through numerical analysis. The distribution of electromagnetic fields in biological tissues emitted by microwave coaxial antenna (MCA) was calculated through the wave equation, and the thermal behavior of the tissue was analyzed through the Pennes bioheat equation. Among various treatment conditions constituting MWA, tumor radius and the slot length inside the MCA were changed, and the resulting treatment effect was quantitatively confirmed through three apoptotic variables. As a result, each tumor radius has optimal power condition for MWA, 2.6W, 2.4W, and 3.0W respectively. This study confirmed optimal therapeutic conditions for MWA. Three apoptotic variables were used to quantitatively identify apoptotic temperature maintenance inside tumor tissue and thermal damage to surrounding normal tissue. The findings of this study are expected to serve as a standard for treatment based on actual MWA treatment. [ABSTRACT FROM AUTHOR]

The effects of varying γ′ size and grain boundary carbide distribution at elevated temperatures on the fatigue behavior of turbine disk alloy RR1000 were examined through combining 2D and 3D imaging characterization. The fatigue crack growth rate at 725°C is higher than at 650°C due to enhanced oxidation damage at higher temperature, dominated by an intergranular fracture mode. This is more marked with longer dwell time (linked to diffusion time) and when carbides have formed continuously at grain boundaries. The fatigue crack path was characterized by X‐ray CT scan to present the complex 3D crack propagation morphology. It is noted that a discontinuous crack path and uncracked ligaments can be discerned ahead of the crack tip particularly in the microstructure where carbides are continuously formed at grain boundaries. This is linked to embrittled zones ahead of the crack tip formed during longer dwell times at the maximum stress during cycling at elevated temperature. Highlights: Effects of microstructure and temperature on fatigue crack growth of Ni‐based superalloy.Deeper understanding of high‐temperature fatigue mechanism by 2D/3D image characterization.X‐ray CT scan revealing complex 3D crack morphology linked to oxidation fatigue mechanism. [ABSTRACT FROM AUTHOR]

Proton resonance frequency shift (PRFS) is an MRI-based simple temperature mapping method that exhibits higher spatial and temporal resolution than temperature mapping methods based on T1 relaxation time and diffusion. PRFS temperature measurements are validated against fiber-optic thermal sensors (FOSs). However, the use of FOSs may introduce temperature errors, leading to both underestimation and overestimation of PRFS measurements, primarily due to material susceptibility changes caused by the thermal sensors. In this study, we demonstrated susceptibility-corrected PRFS (scPRFS) with a high frame rate and accuracy for suitably distributed temperatures. A single-echo-based background removal technique was employed for phase variation correction, primarily owing to magnetic susceptibility, which enabled fast temperature mapping. The scPRFS was used to validate the temperature fidelity by comparing the temperatures of fiber-optic sensors and conventional PRFS through phantom-mimicked human and ex vivo experiments. This study demonstrates that scPRFS measurements in agar-gel are in good agreement with the thermal sensor readings, with a root mean square error (RMSE) of 0.33–0.36 °C in the phantom model and 0.12–0.16 °C in the ex vivo experiment. These results highlight the potential of scPRFS for precise thermal monitoring and ablation in both low- and high-temperature non-invasive therapies. [ABSTRACT FROM AUTHOR]

Lasers are used in various fields, however, in the medical field, they are mainly used for incision or chemotherapy. Photothermal therapy (PTT) is an anti-cancer treatment technique that uses lasers and the photothermal effect to increase the temperature of tumor tissue and induce its death. In this study, the therapeutic effect of PTT using gold nanoparticles as a photothermal converter was analyzed numerically for the occurrence of squamous cell carcinoma inside a skin section consisting four layers. Numerical modeling was implemented to calculate the temperature distribution inside the biological tissue while varying the distribution radius of gold nanoparticles in the tumor tissue, the number of injections, and the intensity of the irradiating laser. For the given situation, the optimal treatment effect was observed when the distribution radius ratio of the injected gold nanoparticles (GNPs) was 1, the number of injections was 7, and the intensity of the irradiated laser was 52 mW. Three apoptotic variables were used to quantitively evaluate the effect of PTT in each case and thus suggest the optimal treatment effect. However, although the temperature range at which apoptosis occurs is known, the maintenance of that temperature range is still under research and the temporal influence of apoptosis remains to be determined. [ABSTRACT FROM AUTHOR]

Recently, the incidence of skin cancer has been increasing owing to the development of science and technology and the increase in outdoor activities. Research on photothermal therapy as a treatment technique for similar skin cancer is in progress. Photothermal therapy is a treatment technique that removes tumor tissue by increasing the temperature. It has the advantage of rapid recovery and a low risk of secondary infection. In this study, a numerical investigation of photothermal therapy based on heat transfer is conducted on squamous cell carcinoma present inside the skin layer. Analysis is performed by varying the number of injections of gold nanoparticles, volume fraction of gold nanoparticles in the tumor, and laser intensity. In addition, conditions for maximizing expression of apoptosis in the tumor and minimizing amount of thermal damage to surrounding normal tissues are identified through the variable which is apoptosis retention ratio, thermal hazard value and effective apoptosis retention ratio. It was confirmed that the optimal therapeutic effect was shown when the volume fraction of injected GNPs was 10−3, the number of injections was 6 times, and the irradiated laser intensity was 140 mW for the tumor presented in this study. Ultimately, these results are expected to accelerate the commercialization of photothermal therapy. [ABSTRACT FROM AUTHOR]

Photothermal therapy is a new chemotherapy technique using photothermal effects, a phenomenon in which light energy is converted into thermal energy. Since the treatment technique is performed without surgical incision, it does not cause bleeding and patients are expected to make rapid recoveries, which are significant advantages. In this study, photothermal therapy with direct injection of gold nanoparticles into tumor tissue was simulated through numerical modeling. The treatment effect resulting from changing the intensity of the irradiated laser, volume fraction of the injected gold nanoparticles, and number of gold nanoparticle injections was quantitatively evaluated. The discrete dipole approximation method was applied to calculate the optical properties of the entire medium, and the Monte Carlo method was applied to identify the absorption and scattering behavior of lasers in tissue. In addition, by confirming the temperature distribution of the entire medium through the calculated light absorption distribution, the treatment effect of photothermal therapy was evaluated, and the optimal treatment conditions were suggested. This is expected to accelerate the popularization of photothermal therapy in the future. [ABSTRACT FROM AUTHOR]

Photothermal therapy is a treatment technique that has attracted attention as an alternative to conventional surgical techniques. It is based on the photothermal effect, wherein light energy is converted into thermal energy, and facilitates rapid recovery after treatment. This study employed various laser irradiation conditions and presented conditions with the optimal treatment effects through a numerical analysis based on heat transfer. A skin layer comprising four stages containing squamous cell carcinoma was targeted, and the treatment effect was confirmed by varying the heating conditions of the laser and volume fraction of gold nanoparticles. The therapeutic effect was confirmed through both the apoptosis retention ratio, which quantitatively estimated the degree of maintenance of the apoptosis temperature range within the tumor, and the thermal hazard retention value, which quantitatively calculates the amount of thermal damage to the surrounding normal tissues. Finally, the optimal treatment conditions were determined based on the laser intensity, cooling time ratio, and volume fraction of injected gold nanoparticles through numerical analysis. [ABSTRACT FROM AUTHOR]

For efficient energy use of air conditioning unit (AC), there is a need to find an optimal control method for operation. To deduce an optimal control algorithm, indoor temperature and power consumption need to be predicted according to given operating conditions. Among the key factors, the thermal ambient parameters such as thermal resistances of the operation sites are most difficult to identify. This study proposed a method for an AC to deduce these parameters for itself by learning operation data obtained from the embedded sensors and autonomously predict indoor temperature and power consumption by solving the transient energy conservation equation incorporating refrigeration cycle simulation. A novel aspect of this study is that the AC can autonomously perceive thermal ambient parameters of its surroundings and utilize these parameters to predict indoor temperature variations and power consumption. These data could be fed back to the control software of the AC in real time. To validate the proposed method, experiments were conducted in model house test facility using a real air-conditioner, and the results were compared with the simulation results. It was confirmed that the time to reach the air temperature setpoint was within 3 min and the power consumption could be predicted within 9 %. [ABSTRACT FROM AUTHOR]

Rectangular coaxial slot arrays (RCSAs) are antennas designed to ensure superior field penetration depth with a high signal‐to‐noise ratio (S/N) in the deeper imaging region of ultra‐high magnetic resonance imaging (MRI). The RCSA consists of a transmission line of λ/4 length surrounded by a dielectric material, and a ground plate that resembles a rectangular coaxial line. We extended this antenna to eight elements. The simulation indicates that a single RCSA has a B1+‐field distribution similar to that of the generally used dipole antenna for traveling RF waves. However, the B1+‐component of the RCSA in an array configuration was stronger in the deep brain region of the human brain model and its specific absorption rate was lower compared to the dipole and monopole antenna arrays. The proposed RSCA array can be adapted to acquire MR signals with high sensitivity in a deeper imaging region in an ultra‐high field MRI scanner. [ABSTRACT FROM AUTHOR]

The photothermal effect refers to a phenomenon in which light energy is converted into heat energy, and in the medical field, therapeutics based on this phenomenon are used for anticancer treatment. A new treatment technique called photothermal therapy kills tumor tissue through a temperature increase and has the advantages of no bleeding and fast recovery. In this study, the results of photothermal therapy for squamous cell carcinoma in the skin layer were analyzed numerically for different laser profiles, intensities, and radii and various concentrations of gold nanoparticles (AuNPs). According to the heat-transfer theory, the temperature distribution in the tissue was calculated for the conditions under which photothermal therapy was performed, and the therapeutic effect was quantitatively confirmed through three apoptotic variables. In addition, the laser intensity and the volume fraction of AuNPs were optimized, and the results provide useful criteria for optimizing the treatment effects in photothermal therapy. [ABSTRACT FROM AUTHOR]

Nanosized materials are used in various industries, depending on their production form. In the medical field, nanosized particles are used for treatment. Among various treatment techniques, photothermal therapy (PTT) uses nanoparticles as photothermal agents (PTAs). In this study, the effectiveness of PTT using noble-metal PTAs with various materials and radii was analyzed using numerical analysis. For squamous cell carcinoma within the skin layer, the thermal behavior of the medium was analyzed when PTT was performed by varying the material and radius of the noble-metal PTAs, the volume fraction of the injected PTAs, and the intensity of the irradiating laser. The optical properties of the PTAs and tissue and the temperature distribution in the tissue under laser irradiation were calculated using the discrete dipole approximation method, the Dombrovsky relation, and the Pennes bioheat equation. In addition, an apoptotic variable was derived based on the calculated temperature distribution, and the optimal treatment conditions for each PTAs material were analyzed. The results of the study showed that the maximum therapeutic effect was achieved at a volume fraction of 10−6 and laser intensity of 0.16 W when all PTAs were used, and the difference in therapeutic effect was insignificant with respect to the radius of the nanoparticles. Accordingly, an accurate PTT can be performed using each PTAs material if the proposed treatment conditions are applied. • Optimization of treatment conditions for skin cancer photothermal therapy. • Squamous cell carcinoma presented in tumor. • Effective apoptosis retention ratio for optimization of photothermal therapy. • Various noble-metal nanoparticles for photothermal agents. • Numerical analysis based on heat transfer to induce apoptosis in tumor. [ABSTRACT FROM AUTHOR]

l Fault diagnosis for single and dual failure for air conditioners using SVM method. l Based on the existing sensors only. l Machine learning based on the database obtained from refrigeration cycle simulation. l Failure mode was detected with an accuracy of higher than 88%. l Failure level was predicted within ±10% of actual data. Owing to the recent uprise in summer temperatures, the use of air conditioners has been increasing accordingly. Air conditioners consume a significant amount of energy, and defects in air conditioners usually could lead to even more consumption of energy. Hence, early detection of defects could not only enhance user satisfaction, but also conserve energy. In the present work, quantitative fault detection models for single- and dual-failure modes have been developed using a support vector machine technique based on refrigeration cycle simulation data including normal and defective conditions. The defect modes investigated in the present work include refrigerant shortage and degraded air flow rates for the evaporator and condenser of an air conditioner. The results indicate that the proposed method can predict the values of more than 95% of the defective parameters within ± 5 % for the single-failure mode, and more than 90% of the data within ± 10 % for the dual-failure mode. [ABSTRACT FROM AUTHOR]

In this study, experiments are conducted to measure the thermal resistances of heat sinks with cross-cut branched fins on horizontal cylinders. The experiments were conducted for several numbers of fin, heights of fins, and heat inputs. From the experimental data, the Nusselt number correlation for Rayleigh numbers of 190000–1000000, fin heights of 10–30 mm, and fin numbers of 9–36 is proposed. Using the suggested correlation, the fin thickness and fin number for maximizing the thermal performance are obtained. Finally, it is demonstrated that the optimal heat sink with cross-cut branched fins on a horizontal cylinder has 26 % lower thermal resistance than that of a conventional heat sink with plate fins. [ABSTRACT FROM AUTHOR]

Herein, the free convection from vertically aligned tubes with curved extended surfaces is experimentally investigated. Heat transfer rates from tubes with curved extended surfaces to the ambient air are quantified under various conditions, including under varying tube wall temperatures, numbers of extended surfaces, and heights of extended surfaces in the radial direction. A correlation for calculating the Nusselt number is suggested, drawing upon the experimental findings. The difference between the experimental outcomes and the estimates generated by this correlation falls within a 10% margin. Using the correlation, a contour diagram is generated to show the thermal resistances across different numbers and thicknesses of extended surfaces. Finally, the thermal resistance of tubes featuring curved extended surfaces is evaluated against tubes with conventional straight extended surfaces. It is found that the tube with curved extended surfaces has a thermal resistance that is 20% less than that with straight extended surfaces. • Experimental investigation of vertical tubes with radially curved fins is conducted. • Radially curved fins reduce thermal resistance more than straight fins. • The maximum observed reduction in thermal resistance is approximately 20%. • A correlation for the prediction of the Nusselt number is proposed. [ABSTRACT FROM AUTHOR]

Isoprenoids are an abundant and diverse class of natural products with various applications in the pharmaceutical, cosmetics and biofuel industries. A methanotroph-based biorefinery is an attractive scenario for the production of a variety of value-added compounds from methane, because methane is a promising alternative feedstock for industrial biomanufacturing. In this study, we metabolically engineered Methylotuvimicrobium alcaliphilum 20Z for de novo synthesis of a sesquiterpenoid from methane, using α-humulene as a model compound, via optimization of the native methylerythritol phosphate (MEP) pathway. Expression of codon-optimized α-humulene synthase from Zingiber zerumbet in M. alcaliphilum 20Z resulted in an initial yield of 0.04 mg/g dry cell weight. Overexpressing key enzymes (IspA, IspG, and Dxs) for debottlenecking of the MEP pathway increased α-humulene production 5.2-fold compared with the initial strain. Subsequently, redirecting the carbon flux through the Embden–Meyerhof–Parnas pathway resulted in an additional 3-fold increase in α-humulene production. Additionally, a genome-scale model using flux scanning based on enforced objective flux method was used to identify potential overexpression targets to increase flux towards isoprenoid production. Several target reactions from cofactor synthesis pathways were probed and evaluated for their effects on α-humulene synthesis, resulting in α-humulene yield up to 0.75 mg/g DCW with 18.8-fold enhancement from initial yield. This study first demonstrates production of a sesquiterpenoid from methane using methanotrophs as the biocatalyst and proposes potential strategies to enhance production of sesquiterpenoid and related isoprenoid products in engineered methanotrophic bacteria. • We demonstrated systematic metabolic engineering of methanotroph for production of α-humulene from methane. • The expression of α-humulene synthase in M. alcaliphilum 20Z resulted in an initial yield of 0.04 mg/gDCW. • By overexpression of key bottlenecks of methylerythritol phosphate pathway, α-humulene production was increased 5.2-fold. • We created a knockout-overexpression assay, selected by metabolic modeling, for increasing α-humulene production. • Final α-humulene production was up to 0.75 mg/g DCW with 18.8-fold enhancement from initial yield. [ABSTRACT FROM AUTHOR]

Acetate, a promising yet underutilized carbon source for biological production, was explored for the efficient production of homoserine and threonine in Escherichia coli W. A modular metabolic engineering approach revealed the crucial roles of both acetate assimilation pathways (AckA/Pta and Acs), optimized TCA cycle flux and glyoxylate shunt activity, and enhanced CoA availability, mediated by increased pantothenate kinase activity, for efficient homoserine production. The engineered strain W–H22/pM2/pR1P exhibited a high acetate assimilation rate (5.47 mmol/g cell/h) and produced 44.1 g/L homoserine in 52 h with a 53% theoretical yield (0.18 mol/mol) in fed-batch fermentation. Similarly, strain W–H31/pM2/pR1P achieved 45.8 g/L threonine in 52 h with a 65% yield (0.22 mol/mol). These results represent the highest reported levels of amino acid production using acetate, highlighting its potential as a valuable and sustainable feedstock for biomanufacturing. • Acetate was successfully utilized for high-level bio-production of homoserine in E. coli. • Conversion of acetate to homoserine was optimized by employing modular metabolic engineering strategies. • Homoserine pathway could be expanded to synthesize threonine from acetate. • A high titer of 44.1 g/L homoserine(53% theoretical yield) or 45.8 g/L threonine(65% theoretical yield) were achieved. [ABSTRACT FROM AUTHOR]

Silica compounds were prepared using non-functionalized solution styrene-butadiene rubber (SSBR) to investigate effect of the functional group of silanes on the silica modification and properties of SSBR/silica compounds. Bis-[3-(triethoxysilyl)propyl]disulfide (TESPD), 3-mercaptopropyltriethoxysilane (MPTES), 3-aminopropyltriethoxysilane (APTES), vinyltriethoxysilane (VTES), and 3-chloropropyltriethoxysilane (CPTES) were used as silane agents. Bound rubber contents and vulcanizate structures were analyzed, and physical properties, cure characteristics and viscoelasticities were evaluated. MPTES and TESPD have chemically reactive functional groups with rubber chain. Particulary, as thiol group is more reactive than disulfide, the filler–rubber interaction is outstanding when applying MPTES. The bound rubber content of the MPTES applied compound was 30% higher. Vulcanizate structure analysis exhibited that the filler–rubber interaction of the MPTES applied compound is more than twice as high. As amino group of APTES can form hydrogen bonds with other amino or silanol groups on silica surface, strong filler–filler interaction which leads to easy agglomeration and accelerator adsorption, resulting in flocculation and marching. VTES cannot hydrophobize silica surface owing to its short carbon chain. Therefore, the compounds that apply APTES or VTES had high Payne effect, indicating poor silica dispersion. CPTES has polar functional group but behaves as covering agent because of its weak interaction with rubber. [ABSTRACT FROM AUTHOR]

In this paper, we present two novel approaches, super rays and culling region, for efficiently updating grid-based occupancy maps with point clouds. Rays, which traverse from the sensor origin to the sensor data, update the occupancy probabilities of a map representing an environment. Based on the ray model, we define a super ray as a representative ray to multiple rays having the same traversal patterns during the map updates. Our super rays utilize the geometric information of rays and reduce the number of points used for updating the map. For constructing super rays efficiently, we propose mapping lines for handling two- and three-dimensional cases from an observation that edges or grid points branch out the traversal patterns on the map. Furthermore, we introduce a culling region using the occupancy states of the updated map for reducing redundant computations occurred in updates. The super rays perform the update process in a single traversal, and the culling region reduces the number of unnecessary traversals for updating the map. As a result, our combined method improves the update performance without compromising any representation accuracy of a grid-based map. We test the update performance of the proposed method using public indoor and outdoor datasets. Our combined approach shows up to 11.8 times and 2.8 times performance improvement over the state-of-the-art update methods of grid-based maps in the indoor and outdoor scenes, respectively. Also, we compare the update speed and the representation accuracy of our method using the KITTI dataset over the state-of-the-art learning-based occupancy maps. In a navigation scenario that raw point clouds are acquired in 10 Hz, our method shows the best performance on the update speed and thus the highest representation accuracy within a given time. [ABSTRACT FROM AUTHOR]

The goal of sustainable production of biochemicals and biofuels has driven the engineering of microbial cell as factories that convert low-value substrates to high-value products. Xylose is the second most abundant sugar substrate in lignocellulosic hydrolysates. We analyzed the mechanisms of xylose metabolism using genome sequencing data of 492 industrially relevant bacterial species in the mini-review. The analysis revealed the xylose isomerase and Weimberg pathways as the major routes across diverse routes of bacterial xylose metabolism. In addition, we discuss recent developments in metabolic engineering of xylose metabolism in industrial microorganisms. Genome-scale analyses have revealed xylose pathway-specific flux landscapes. Overall, a comprehensive understanding of bacterial xylose metabolism could be useful for the feasible development of microbial cell factories. [ABSTRACT FROM AUTHOR]

• Geometrical decoupling method using Clip-path conductor for radiofrequency coil array is proposed. • The geometry of Clip-path conductor was designed through electromagnetic simulation. • The performance of proposed coil array was compared with a capacitive decoupled RF coil array in terms of scattering parameters, RF transmitting magnetic field, noise correlation, geometry factor and specific absorption rate. • Brain MR images of healthy volunteers were acquired using the proposed coil array. In magnetic resonance imaging (MRI), a radiofrequency (RF) coil array with a large number of elements is commonly employed for transmission and reception to improve the uniformity of the RF transmitting magnetic field and increase the signal-to-noise ratio. Additionally, multi-element RF arrays can reduce the acquisition time using the parallel imaging technique. However, mutual inductance coupling is unavoidable in multi-element RF coil arrays. Therefore, many researchers have studied geometric and artificial decoupling techniques to minimize mutual inductance coupling. This study proposes a decoupling method using clip-path conductors (CPCs). The CPC geometry locates the top-right and bottom-left positions in the loop coil to reduce the mutual inductance coupling between adjacent elements. The decoupling performance of the CPC coil was verified via electromagnetic simulations and bench measurements. An eight-element transceiver CPC array was manufactured, and phantom and healthy volunteer images were acquired using a 7-T MRI system. [ABSTRACT FROM AUTHOR]

• Optimization of treatment conditions for skin cancer photothermal therapy. • Multiple blood vessels presented in tumor by angiogenesis. • Effective apoptosis retention ratio for optimal photothermal therapy was determined. • Numerical analysis based on heat transfer to induce apoptosis was conducted. • Tumor apoptosis and thermal damage to surrounding normal tissue were quantified. In recent years, lasers have gained considerable attention as a potential treatment option in the medical field. Photothermal therapy, in particular, has been investigated as a technique to remove tumor tissue by leveraging photothermal effects. The method involves raising the temperature of the tumor tissue to destroy it and has primarily been studied for skin cancer treatment. This study aimed to simulate a skin layer with squamous cell carcinoma by using numerical modeling and investigate the effect of different numbers of blood vessels on the temperature distribution in the medium under conditions such as varied laser intensity and gold nanoparticle volume fraction. Optical properties of the light absorption enhancer were calculated using the discrete dipole approximation method, and the temperature and velocity distribution were computed using continuity, momentum, and energy equations. Quantitative determination of the apoptotic variable was performed to evaluate the treatment effect for each case, and the treatment condition with the maximum treatment effect was identified. Laser intensity with optimal therapeutic effect was confirmed to be 0.13 W, 0.15 W, 0.18 W, and 0.24 W, depending on the number of vessels, respectively, and the volume fraction of injected GNRs was confirmed to be 10−6 for all vessel numbers. The results of this study can serve as a guide for selecting appropriate treatment conditions when conducting photothermal therapy in the future [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: In response to the demand for flexible and sustainable energy storage devices that exhibit high electrochemical performance, a supercapacitor system is fabricated using mulberry tree‐derived paper as a substrate and Poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) and carbon black as the active material. The mulberry paper‐based supercapacitor system demonstrates high energy density of 29.8–39.8 Wh kg−1 and power density of 2.8–13.9 kW kg−1 with 90.7% retention of its initial capacity over 15 000 charge–discharge cycles. In addition, the mulberry tree fibers are known to have superior mechanical strength and toughness and the mulberry paper‐based supercapacitor; as a result, exhibit high mechanical and chemical toughness; 99% of its initial capacity is retained after 100 repeated applications of bending strains, and twisting. 94% capacity retention is observed even after exposure to HCl and H2SO4 acid solutions. The fabrication methodology of the mulberry‐based supercapacitor is highly scalable and could be stacked to increase the energy storage capacity, where operation of light‐emitting diode lights with a drive voltage of 12 V integrated in a wearable device is demonstrated. [ABSTRACT FROM AUTHOR]

Aptamers, oligonucleic acid or peptide molecules with binding affinity to a specific molecule, have gained broad scientific attention due to their stability, ease of production and modification, and durability, and therefore have been employed in a wide range of applications both in basic research and clinical science. Recent advances in high-throughput sequencing are poised to revolutionize the selection of aptamers, while microfluidic and microarray approaches have helped automate these processes of selection. Here we highlight work addressing several challenges in using aptamers more widely. We discuss array-based discovery of multivalent aptamers which is used to develop high affinity or paired aptamers by cleverly selecting new aptamers that bind to previously aptamer-bound proteins. Other highlighted work is addressing problems in analyzing local cell secretions, as well as refreshable sensors that detect signals over hundreds of cycles and can be refreshed with DI water scavenged from the air, leading to less reagent storage towards wearable sensors. [ABSTRACT FROM AUTHOR]

The ability to break up a volume of fluid into smaller pieces that are confined or separated to prevent molecular communication/transport is a key capability intrinsic to microfluidic systems. This capability has been used to develop or implement digital versions of traditional molecular analysis assays, including digital PCR and digital immunoassays/ELISA. In these digital versions, the concentration of the target analyte is in a range such that, when sampled into smaller fluid volumes, either a single molecule or no molecule may be present. Subsequent amplification is sensitive enough to obtain a digital readout of the presence of these target molecules. Advantages of such approaches that are claimed include quantification without calibration and robustness to variations in reaction conditions or times because the digital readout is less sensitive to absolute signal intensity levels. Weaknesses of digital approaches include a lower dynamic range of concentrations over which the assay is sensitive, which depends on the total volume that can be analyzed. We highlight recent efforts to expand the dynamic range of digital assays based on exploiting reaction/diffusion phenomena. A side-by-side study that evaluates the strengths of digital assays reveals that the majority of these claims are supported, with specific caveats. Finally, we highlight approaches to apply digital assays to analyze new types of reactions, including the active transport of protons across membranes by ATPases at the single protein level - perhaps opening up new biophysical understanding and screening opportunities, similar to widely deployed single-molecule ion channel analysis. [ABSTRACT FROM AUTHOR]

Neutrophils are critical inflammatory cells; thus, it is important to characterize the effects of drugs on neutrophil function in the context of inflammatory diseases. Herein, chemically guided neutrophil migration, known as chemotaxis, is studied in the context of drug treatment at the single cell level using a microfluidic platform, complemented by cell viability assays and calcium imaging. Three representative drugs known to inhibit surface receptor expression, signaling enzyme activity, and the elevation of intracellular Ca2+ levels, each playing a significant role in neutrophil chemotactic pathways, are used to examine the in vitro drug effects on cellular behaviors. The microfluidic device establishes a stable concentration gradient of chemokines across a cell culture chamber so that neutrophil migration can be monitored under various drug-exposure conditions. Different time- and concentration-dependent regulatory effects were observed by comparing the motility, polarization, and effectiveness of neutrophil chemotaxis in response to the three drugs. Viability assays revealed distinct drug capabilities in reducing neutrophil viability while calcium imaging clarified the role of Ca2+ in the neutrophil chemotaxis. This study provides mechanistic insight into the drug effects on neutrophil function, facilitating comparison of current and potential pharmaceutical approaches. [ABSTRACT FROM AUTHOR]

Microfluidic sensing platforms facilitate parallel, low sample volume detection using various optical signal transduction mechanisms. Herein, we introduce a simple mixing microfluidic device, enabling serial dilution of introduced analyte solution that terminates in five discrete sensing elements. We demonstrate the utility of this device with on-chip fluorescence and surface-enhanced Raman scattering (SERS) detection of analytes, and we demonstrate device use both when combined with a traditional inflexible SERS substrate and with SERS-active nanoparticles that are directly incorporated into microfluidic channels to create a flexible SERS platform. The results indicate, with varying sensitivities, that either flexible or inflexible devices can be easily used to create a calibration curve and perform a limit of detection study with a single experiment. [ABSTRACT FROM AUTHOR]

Graphene has been considered to be a potential alternative transparent and flexible electrode for replacing commercially available indium tin oxide (ITO) anode. However, the relatively high sheet resistance and low work function of graphene compared with ITO limit the application of graphene as an anode for organic or polymer light-emitting diodes (OLEDs or PLEDs). Here, flexible PLEDs made by using bis(trifluoromethanesulfonyl)amide (TFSA, [CF3SO2]2NH) doped graphene anodes are demonstrated to have low sheet resistance and high work function. The graphene is easily doped with TFSA by means of a simple spin-coating process. After TFSA doping, the sheet resistance of the TFSA-doped five-layer graphene, with optical transmittance of ≈88%, is as low as ≈90 Ω sq−1. The maximum current efficiency and power efficiency of the PLED fabricated on the TFSA-doped graphene anode are 9.6 cd A−1 and 10.5 lm W−1, respectively; these values are markedly higher than those of the PLED fabricated on pristine graphene anode and comparable to those of an ITO anode. [ABSTRACT FROM AUTHOR]

The human body is a complex network of molecules,organelles, cells,tissues, and organs: an uncountable number of interactions and transformationsinterconnect all the system’s components. In addition to thesebiochemical components, biophysical components, such as pressure,flow, and morphology, and the location of all of these interactionsplay an important role in the human body. Technical difficulties havefrequently limited researchers from observing cellular biology asit occurs within the human body, but some state-of-the-art analyticaltechniques have revealed distinct cellular behaviors that occur onlyin the context of the interactions. These types of findings have inspiredbioanalytical chemists to provide new tools to better understand thesecellular behaviors and interactions. [ABSTRACT FROM AUTHOR]

Determining how facultative anaerobic organisms sense and direct cellular responses to electron acceptor availability has been a subject of intense study. However, even in the model organism Escherichia coli, established mechanisms only explain a small fraction of the hundreds of genes that are regulated during electron acceptor shifts. Here we propose a qualitative model that accounts for the full breadth of regulated genes by detailing how two global transcription factors (TFs), ArcA and Fnr of E. coli, sense key metabolic redox ratios and act on a genome-wide basis to regulate anabolic, catabolic, and energy generation pathways. We first fill gaps in our knowledge of this transcriptional regulatory network by carrying out ChIP-chip and gene expression experiments to identify 463 regulatory events. We then interfaced this reconstructed regulatory network with a highly curated genome-scale metabolic model to show that ArcA and Fnr regulate >80% of total metabolic flux and 96% of differential gene expression across fermentative and nitrate respiratory conditions. Based on the data, we propose a feedforward with feedback trim regulatory scheme, given the extensive repression of catabolic genes by ArcA and extensive activation of chemiosmotic genes by Fnr. We further corroborated this regulatory scheme by showing a 0.71 r2 (p<1e-6) correlation between changes in metabolic flux and changes in regulatory activity across fermentative and nitrate respiratory conditions. Finally, we are able to relate the proposed model to a wealth of previously generated data by contextualizing the existing transcriptional regulatory network. [ABSTRACT FROM AUTHOR]

Mesoporous silica nanoparticles are promising drug delivery agents; however, their interaction with various in vivo biological components is still under investigation. In this work, the impact of sub-50 nm diameter mesoporous silica nanoparticles on platelet function is investigated using a microfluidic platform to model blood vessel characteristics. Platelet adhesion and aggregation in the presence of mesoporous silica nanoparticles is investigated, controlling whether or not platelets are activated ahead of nanoparticle exposure. The results indicate that nanoparticles slightly compromise platelet adhesion to endothelial cells at low nanoparticle doses, but that high nanoparticle doses significantly increase the number of platelet adhesion events, leading to higher probability for uncontrolled platelet actions (e.g. clot formation in vivo). High nanoparticle doses also induced platelet aggregation. While platelet activation and aggregation occurred, in no case did nanoparticle exposure result in significant loss of platelet viability; as such, this work clearly demonstrates that aspects besides viability, such as cellular adhesion and interaction with other cell types, have to be considered in the context of nanotoxicology. This simple and highly adaptable analytical platform will be useful for further nanotoxicity studies involving other nanoparticle and cell types. [ABSTRACT FROM AUTHOR]

Neutrophils act as the first line of defence in the human immune system by migrating to the site of abnormal events and performing their designated roles. One major signalling pathway that drives neutrophil action in vivo is the p38 mitogen-activated protein kinase (MAPK)-dependent pathway. Herein, a microfluidic platform is employed to explore the mechanistic role of p38 MAPK in neutrophil chemotaxis. Neutrophils, with and without p38 MAPK inhibition, were exposed to pairwise competing gradients of chemotaxis-inducing molecules. Overall, p38 MAPK inhibitor-treated neutrophils were still capable of moving toward a chemoattractant signal; however, the hierarchy of neutrophil response to various chemoattractants changed and there was more deviation from direct movement toward a chemoattractant signal in p38 MAPK-blocked cells. In a parallel fluorescence imaging study, neutrophil expression of surface receptors (CXCR1, FPR2, BLTR, CD11b and CD66b) changed when comparing untreated and p38 MAPK-blocked cells. All results demonstrate that the p38 MAPK-dependent pathway plays a critical role in neutrophil chemotaxis and this role is, in part, through the regulation of surface receptor expression. These data regarding how receptor expression and chemotaxis are influenced by the p38 MAPK pathways lend insight into neutrophil behaviour in physiological environments and the potential manipulation of p38 MAPK for therapeutic purposes. [ABSTRACT FROM AUTHOR]

Due to increased exposure to ultraviolet radiation caused by increased outdoor activities, the incidence of skin cancer is increasing. Incision is the most typical method for treating skin cancer, and various treatments that can minimize the risks of incision surgery are being investigated. Among them, photothermal therapy is garnering attention because it does not cause bleeding and affords rapid recovery. In photothermal therapy, tumor death is induced via temperature increase. In this study, a numerical study based on heat transfer theory was conducted to investigate the death of squamous cell carcinoma located in the skin layer based on various shapes of gold nanoparticles (AuNPs) used in photothermal therapy. The quantitative correlation between the conditions of various AuNPs and the laser intensity that yields the optimal photothermal treatment effect was derived using the effective apoptosis ratio. It was confirmed that optimal conditions exist for maximizing apoptosis within a tumor tissue and minimizing the thermal damage to surrounding normal tissues when using AuNPs under various conditions. Furthermore, it is envisioned that research result will be utilized as a standard for photothermal treatment in the future. [ABSTRACT FROM AUTHOR]

The article examines the carbon-fiber microelectrodes (CFM) techniques which have illuminated the underpinnings of exocytosis. It discusses the measurement of single cell exocytosis with microelectrodes, covering history, basic instrumentation, cell types as well as the fundamental insight. It concludes that studies are currently underway to improve the methods for broader application.

Recently, photothermal therapy has attracted attention as an alternative treatment to conventional surgical techniques because it does not lead to bleeding and patients quickly recover after treatment compared to incisional surgery. Photothermal therapy induces tumor cell death through an increase in the temperature using the photothermal effect, which converts light energy into thermal energy. This study was conducted to perform numerical analysis based on heat transfer to induce apoptosis of tumor tissue under various heating conditions in photothermal therapy. The Monte Carlo method was applied to evaluate a multi-layered skin structure containing squamous cell carcinoma. Tissue-equivalent phantom experiments verified the numerical model. Based on the effective apoptosis retention ratio, the numerical analysis results showed the quantitative correlation for the laser intensity, volume fraction of gold nanorods injected into the tumor, and cooling time. This study reveals optimal conditions for maximizing apoptosis within tumor tissue while minimizing thermal damage to surrounding tissues under various heating conditions. This approach may be useful as a standard treatment when performing photothermal therapy. [ABSTRACT FROM AUTHOR]

• Vertical cylinders with branched pin fins are experimentally investigated. • Branched pin fins exhibit reduced thermal resistance compared to plate fins. • The maximum reduction in thermal resistance is approximately 20%. • A correlation for predicting the Nusselt number is proposed. In this study, the natural convection heat transfer phenomena from vertical cylinders with branched pin fins are experimentally investigated. Experiments are conducted to measure the heat transfer rates from finned cylinders to the surrounding air at various cylinder wall temperatures, fin pitch angles, and fin heights. The experimental results indicate that the thermal resistance of vertical cylinders with branched pin fins is 20% smaller than that of conventional vertical cylinders with plate fins. The thermal resistance per unit fin volume of the former is 40% smaller than that of conventional finned cylinders. Moreover, a correlation for the Nusselt number is obtained from the calculated thermal resistance values. The error between the predictions from the correlation and experimental results is less than 20%. In addition, the effects of fin length and fin pitch angle on the thermal resistance are investigated using the proposed correlation. [ABSTRACT FROM AUTHOR]

In this study, we examined the feasibility of using epoxidized liquid isoprene rubber (E-LqIR) as a processing aid for truck and bus radial (TBR) tire treads and investigated the effects of the epoxide content on the wear resistance, fuel efficiency, and resistance to extraction of the E-LqIRs. The results confirmed that, compared to the treated distillate aromatic extract (TDAE) oil, the E-LqIRs could enhance the filler–rubber interactions and reduce the oil migration. However, the consumption of sulfur by the E-LqIRs resulted in a lower crosslink density compared to that of the TDAE oil, and the higher epoxide content decreased the wear resistance and fuel efficiency because of the increased glass-transition temperature (Tg). In contrast, the E-LqIR with a low epoxide content of 6 mol% had no significant effect on the Tg of the final compound and resulted in superior wear resistance and fuel efficiency, compared to those shown by TDAE oil, because of the higher filler–rubber interactions. [ABSTRACT FROM AUTHOR]

Recently, research conducted on tread compounds with liquid butadiene rubber (LqBR) have been conducted in the tire industry. In particular, the introduction of functional groups into LqBRs is expected to lower hysteresis loss caused by the free chain ends of LqBR. To study this, LqBRs with functional groups at different positions were synthesized. The occurrences of in-chain and chain-end functionalization of functionalized LqBRs (F-LqBRs) were confirmed, the microstructure and functionalization efficiency of F-LqBRs were calculated through the characterizations. This novel functionalization technology was beneficial not only to immobilizing the free chain ends of LqBRs to the surfaces of silica to decrease the number of free chain ends, but also chemically bonding the LqBR chains on the base polymer through a crosslinking reaction to enhance the filler-rubber interaction. The effects of the functional group position and number of the free chain ends on the physical properties and hysteresis of the compounds were investigated by partially replacing the treated distillate aromatic extract (TDAE) oil with LqBR in silica-filled rubber compounds. The results showed that compounds that had applied DF-LqBR with both end functionalization performed better, including improving the silica dispersion, higher extraction resistance, and lower rolling resistance, than other F-LqBRs compounds. [ABSTRACT FROM AUTHOR]

The demand for truck–bus radial (TBR) tires with enhanced fuel efficiency has grown in recent years. Many studies have investigated silica-filled natural rubber (NR) compounds to address these needs. However, silica-filled compounds offer inferior abrasion resistance compared to carbon black-filled compounds. Further, the use of NR as a base rubber can hinder silanization and coupling reactions due to interference by proteins and lipids. Improved silica dispersion be achieved without the use of a silane coupling agent by introducing epoxide groups to NR, which serve as silica-affinitive functional groups. Furthermore, the coupling reaction can be promoted by facilitating chemical interaction between the hydroxyl group of silica and the added epoxide groups. Thus, this study evaluated the properties of commercialized NR, ENR-25, and ENR-50 compounds with or without an added silane coupling agent, and the filler–rubber interaction was quantitatively calculated using vulcanizate structure analysis. The increased epoxide content, when the silane coupling agent was not used, improved silica dispersion, abrasion resistance, fuel efficiency, and wet grip. Once a basic level of silica dispersion was secured by using the silane coupling agent, both the abrasion resistance and wet grip improved with increasing epoxide content. Furthermore, the silane coupling agent could be partially replaced by ENR due to the high filler–rubber interaction between the ENR and silica. Therefore, epoxidation shows potential for resolving the issues associated with poor coupling reactions and abrasion resistance in silica-filled NR compounds. [ABSTRACT FROM AUTHOR]

The implementation of vehicle electrification and autonomous driving technologies has recently emphasized the importance of abrasion resistance and fuel efficiency of truck bus radial (TBR) tire treads that undergo high loads and long driving times. In this study, a functionalized liquid butadiene rubber (F-LqBR) was introduced to replace the treated distillate aromatic extracted (TDAE) oil as a way to improve abrasion resistance and fuel efficiency in the TBR tire tread compound and to solve the oil migration. First, radical polymerization was used to synthesize nonfunctionalized LqBR (N-LqBR) and amino-LqBR with an amine group at the chain ends. The synthesized LqBRs were then substituted in place of TDAE oil to manufacture carbon-black-filled natural rubber (NR) compounds and to evaluate their physical properties. The results show that LqBRs improved the migration resistance and enhanced the abrasion resistance by lowering the glass transition temperature (Tg) of the compound. In particular, amino-LqBR improved carbon black dispersion in the rubber matrix through a chemical bond between the functional group of the carbon black surface and the base rubber. In conclusion, amino-LqBR successfully served as a processing aid in a carbon black-filled NR compound while simultaneously enhancing its fuel efficiency and abrasion resistance. [ABSTRACT FROM AUTHOR]

Liquid butadiene rubber (LqBR) which used as a processing aid play a vital role in the manufacturing of high-performance tire tread compounds. However, the studies on the effect of molecular weight, microstructure, and functionalization of LqBR on the properties of compounds are still insufficient. In this study, non-functionalized and center-functionalized liquid butadiene rubbers (N-LqBR and C-LqBR modified with ethoxysilyl group, respectively) were synthesized with low vinyl content and different molecular weights using anionic polymerization. In addition, LqBR was added to the silica-filled SSBR compounds as an alternative to treated distillate aromatic extract (TDAE) oil, and the effect of molecular weight and functionalization on the properties of the silica-filled SSBR compound was examined. C-LqBR showed a low Payne effect and Mooney viscosity because of improved silica dispersion due to the ethoxysilyl functional group. Furthermore, C-LqBR showed an increased crosslink density, improved mechanical properties, and reduced organic matter extraction compared to the N-LqBR compound. LqBR reduced the glass transition temperature (Tg) of the compound significantly, thereby improving snow traction and abrasion resistance compared to TDAE oil. Furthermore, the energy loss characteristics revealed that the hysteresis loss attributable to the free chain ends of LqBR was dominant. [ABSTRACT FROM AUTHOR]

The tire industry has shown an increasing demand for the reduction in rolling resistance. Efforts have been made to improve the viscoelastic properties of tire compounds and reduce the weight of tires through optimization of the vulcanizate structure, which has become extremely complex. In this study, vulcanizates using carbon black and silica as binary fillers were prepared at various curing temperatures. Vulcanizate structures with respect to curing temperature were classified according to the chemical crosslink density by sulfur, carbon black bound rubber (i.e., physical crosslink due to carbon black), and silica-silane–rubber network. All properties exhibited a decreasing trend under the application of high curing temperatures, and the decrease in the crosslink density per unit content of filler with an increase in curing temperature was shown to be greater in carbon black than in silica. Mechanical and viscoelastic properties were also measured to evaluate the impact that the compound variates have on tire tread performance. These results serve as a guideline for determining the content and filler type and for setting the cure condition during the design of actual compound formulations to increase the crosslink density of rubber while retaining the necessary mechanical and viscoelastic properties for practical application. [ABSTRACT FROM AUTHOR]

• A glucose inducible gene expression system has been developed. • An Escherichia coli strain was metabolically engineered to activate the ED pathway. • The addition of external inducer is not required to induce gene expression in this system. • The engineered strain increased the BDO concentration by 71% than the control strain. • The strain produced 11 g/L of BDO from a cellulosic biomass at a yield of 0.48 g/g. A glucose-inducible gene expression system has been developed using HexR-P zwf1 of Pseudomonas putida to induce the metabolic pathways. Since the system is controlled by an Entner–Doudoroff pathway (EDP) intermediate, the EDP of Escherichia coli was activated by deleting pfkA and gntR genes. Growth experiment with green fluorescent protein as a reporter indicated that the induction of this system was tightly controlled over a wide range of glucose in E. coli without adding any inducer. 2,3-butanediol (BDO) synthetic pathway genes were expressed by this system in the pfkA - gntR- deleted strain. The resultant engineered strain harbouring this system efficiently produced BDO with a 71% increased titer than the control strain. The strain was also able to produce BDO from a mixture of glucose and xylose which is comparable to glucose alone. Further, the strain produced 11 g/L of BDO at a yield of 0.48 g/g from the hydrolysate of empty palm fruit bunches. This system can also be applied in many other bio-production processes from lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

Background: Methanotrophs play an important role in biotechnological applications, with their ability to utilize single carbon (C1) feedstock such as methane and methanol to produce a range of high-value compounds. A newly isolated obligate methanotroph strain, Methylomonas sp. DH-1, became a platform strain for biotechnological applications because it has proven capable of producing chemicals, fuels, and secondary metabolites from methane and methanol. In this study, transcriptome analysis with RNA-seq was used to investigate the transcriptional change of Methylomonas sp. DH-1 on methane and methanol. This was done to improve knowledge about C1 assimilation and secondary metabolite pathways in this promising, but under-characterized, methane-bioconversion strain. Results: We integrated genomic and transcriptomic analysis of the newly isolated Methylomonas sp. DH-1 grown on methane and methanol. Detailed transcriptomic analysis indicated that (i) Methylomonas sp. DH-1 possesses the ribulose monophosphate (RuMP) cycle and the Embden–Meyerhof–Parnas (EMP) pathway, which can serve as main pathways for C1 assimilation, (ii) the existence and the expression of a complete serine cycle and a complete tricarboxylic acid (TCA) cycle might contribute to methane conversion and energy production, and (iii) the highly active endogenous plasmid pDH1 may code for essential metabolic processes. Comparative transcriptomic analysis on methane and methanol as a sole carbon source revealed different transcriptional responses of Methylomonas sp. DH-1, especially in C1 assimilation, secondary metabolite pathways, and oxidative stress. Especially, these results suggest a shift of central metabolism when substrate changed from methane to methanol in which formaldehyde oxidation pathway and serine cycle carried more flux to produce acetyl-coA and NADH. Meanwhile, downregulation of TCA cycle when grown on methanol may suggest a shift of its main function is to provide de novo biosynthesis, but not produce NADH. Conclusions: This study provides insights into the transcriptomic profile of Methylomonas sp. DH-1 grown on major carbon sources for C1 assimilation, providing in-depth knowledge on the metabolic pathways of this strain. These observations and analyses can contribute to future metabolic engineering with the newly isolated, yet under-characterized, Methylomonas sp. DH-1 to enhance its biochemical application in relevant industries. [ABSTRACT FROM AUTHOR]

Background: Methanotrophs is a promising biocatalyst in biotechnological applications with their ability to utilize single carbon (C1) feedstock to produce high-value compounds. Understanding the behavior of biological networks of methanotrophic bacteria in different parameters is vital to systems biology and metabolic engineering. Interestingly, methanotrophic bacteria possess the pyrophosphate-dependent 6-phosphofructokinase (PPi-PFK) instead of the ATP-dependent 6-phosphofructokinase, indicating their potentials to serve as promising model for investigation the role of inorganic pyrophosphate (PPi) and PPi-dependent glycolysis in bacteria. Gene knockout experiments along with global-omics approaches can be used for studying gene functions as well as unraveling regulatory networks that rely on the gene product. Results: In this study, we performed gene knockout and RNA-seq experiments in Methylotuvimicrobium alcaliphilum 20Z to investigate the functional roles of PPi-PFK in C1 metabolism when cells were grown on methane and methanol, highlighting its metabolic importance in C1 assimilation in M. alcaliphilum 20Z. We further conducted adaptive laboratory evolution (ALE) to investigate regulatory architecture in pfk knockout strain. Whole-genome resequencing and RNA-seq approaches were performed to characterize the genetic and metabolic responses of adaptation to pfk knockout. A number of mutations, as well as gene expression profiles, were identified in pfk ALE strain to overcome insufficient C1 assimilation pathway which limits the growth in the unevolved strain. Conclusions: This study first revealed the regulatory roles of PPi-PFK on C1 metabolism and then provided novel insights into mechanism of adaptation to the loss of this major metabolic enzyme as well as an improved basis for future strain design in type I methanotrophs. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae KCCM 51299, a potential probiotic yeast overproducing glutathione, has been isolated from among 272 yeast strains from the relatively safe Nuruk. The genome sequence of S. cerevisiae KCCM 51299 was analyzed and a near-complete genome (12 Mb) with 19 contigs was assembled after PacBio single-molecule real-time (SMRT) sequencing. The genome of S. cerevisiae KCCM 51299 was compared to the S. cerevisiae s288c reference genome. Additionally, genes involved in glutathione biosynthesis were identified, and the glutathione biosynthesis pathway was constructed in silico based on these genes. Furthermore, S. cerevisiae KCCM 51299 genes were compared with those in other yeast genomes. Finally, genome-scale in silico flux analysis was carried out, and a metabolic engineering strategy for glutathione biosynthesis was generated. These results provide useful information to further develop eukaryotic probiotics to overproduce glutathione. [ABSTRACT FROM AUTHOR]

Methylobacterium is a genus belonging to the pink-pigmented facultative methylotrophs, which can use C1 substrates as a sole carbon source. Methylorubrum extorquens (formerly Methylobacterium extorquens) is a potentially valuable bacteria in methanol-based bioindustry producing high-value-added chemicals. Thus, it is critical to understand the core metabolic pathways of M. extorquens strains for further advancement as a platform bacterium in the bioindustry. However, there are no reported systems biological approaches comparing different M. extorquens strains. This paper focuses on comparing the genomic properties of seven completely sequenced M. extorquens strains, including M. extorquens PA1, which was re-sequenced, and M. extorquens ATCC 55366, which was newly sequenced in this study. Pan-genome analysis indicated that a total of 10,431 ortholog clusters composed the pan-genome of these M. extorquens strains, including 3,507 core genome, 1,860 accessory genome, and 5,064 unique genome clusters. The functional annotation discovered that genes related to signal transduction were the most abundant in the pan-genome. Pan-genome analysis of two different habitat-specific groups revealed that the strains isolated from various soil environments had a higher percentage of genes involved in mobilome in their core genome. Subsequent exploration for secondary metabolite biosynthesis clusters denoted the unique ability of M. extorquens AM1 to produce various toblerols. M. extorquens PA1 could be a strong candidate for industrial strain development because of its minimal genome size with fully conserved central metabolism. This study provides the first inclusive insight into the differences in genomic characteristics of central metabolic networks of M. extorquens. [ABSTRACT FROM AUTHOR]

Summary: Clavibacter michiganensis ssp. capsici is a Gram‐positive plant‐pathogenic bacterium causing bacterial canker disease in pepper. Virulence genes and mechanisms of C. michiganensis ssp. capsici in pepper have not yet been studied. To identify virulence genes of C. michiganensis ssp. capsici, comparative genome analyses with C. michiganensis ssp. capsici and its related C. michiganensis subspecies, and functional analysis of its putative virulence genes during infection were performed. The C. michiganensis ssp. capsici type strain PF008 carries one chromosome (3.056 Mb) and two plasmids (39 kb pCM1Cmc and 145 kb pCM2Cmc). The genome analyses showed that this bacterium lacks a chromosomal pathogenicity island and celA gene that are important for disease development by C. michiganensis ssp. michiganensis in tomato, but carries most putative virulence genes in both plasmids. Virulence of pCM1Cmc‐cured C. michiganensis ssp. capsici was greatly reduced compared with the wild‐type strain in pepper. The complementation analysis with pCM1Cmc‐located putative virulence genes showed that at least five genes, chpE, chpG, ppaA1, ppaB1 and pelA1, encoding serine proteases or pectate lyase contribute to disease development in pepper. In conclusion, C. michiganensis ssp. capsici has a unique genome structure, and its multiple plasmid‐borne genes play critical roles in virulence in pepper, either separately or together. [ABSTRACT FROM AUTHOR]

As the world is shifting from internal combustion engine vehicles to electric vehicles in response to environmental pollution, the tire industry has been conducting research on tire performance to meet the requirements of electric vehicles. In this experiment, functionalized liquid butadiene rubber (F-LqBR) with triethoxysilyl groups at both ends was introduced into a silica-filled rubber compound as a substitute for treated distillate aromatic extract (TDAE) oil, and comparative evaluation was conducted according to the number of triethoxysilyl groups. The results showed that F-LqBRs improved silica dispersion in the rubber matrix through the formation of chemical bonds between silanol groups and the base rubber, and reduced rolling resistance by limiting chain end mobility and improving filler–rubber interaction. However, when the number of triethoxysilyl groups in F-LqBR was increased from two to four, self-condensation increased, the reactivity of the silanol groups decreased, and the improvement of properties was reduced. As a result, the optimized end functionality of triethoxysilyl groups for F-LqBR in silica-filled rubber compound was two. The 2-Azo-LqBR with the optimized functionality showed an improvement of 10% in rolling resistance, 16% in snow traction, and 17% in abrasion resistance when 10 phr of TDAE oil was substituted. [ABSTRACT FROM AUTHOR]

Platelets are small (1–2 μm in diameter), circulating anuclear cell fragments with important roles in hemostasis and thrombosis that provide an excellent platform for studying the role of membrane components in cellular communication. Platelets use several forms of communication including exocytosis of three distinct granule populations, formation of bioactive lipid mediators, and shape change (allowing for adhesion). This work explores the role of stereochemistry and concentration of exogenous phosphatidylserine (PS) on platelet exocytosis and adhesion. PS, most commonly found in the phosphatidyl- l -serine ( l -PS) form, is exposed on the outer leaflet of the cell membrane after the platelet is activated. Knowledge about the impact of exogenous phosphatidylserine on cell-to-cell communication is limited (particularly concentration and stereochemistry effects). This study found that platelets incubated in l -PS or phosphatidyl- d -serine ( d -PS) are enriched to the same extent with their respective incubated PS. All levels of l -PS enrichment also showed an increase in platelet cholesterol, but only the 50 μM d -PS incubation showed an increase in cholesterol. The uptake of d -PS induced the secretion of granules and manufactured platelet activating factor (PAF) in otherwise unstimulated platelets. The uptake of l -PS had a greater impact on platelet stimulation by decreasing both the amount of δ-granule secretion and the amount of PAF that was manufactured. [ABSTRACT FROM AUTHOR]