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In this study, we investigated the effect of high temperature on the mechanical behavior of Hwangdeung granite in Korea. Uniaxial compression and Brazilian tests were performed under temperatures ranging from 20 °C to 250 °C. The development of the thermally induced microcracks was observed utilizing a scanning electron microscope (SEM). The target temperature was chosen for rock engineering projects, such as high-level radioactive waste disposal, enhanced geothermal energy, and thermal energy storage. Considering the long-term strength and fracture process associated with crack development, we examined the temperature dependence of crack initiation and propagation thresholds and conventional strength and deformation parameters, as well as the stress-strain relation under high temperature. Compressive strength, tensile strength, and Young's modulus decreased with increasing temperature, particularly at temperatures above 100 °C, and Poisson's ratio decreased linearly. The changes in the tensile strength and elastic constants were more pronounced than those in uniaxial compressive strength. The stress-strain curves revealed that the thermal effect on deformation, rather than strength, was evident. Microscopic observations of the heated rock samples have revealed that high temperature promoted the interaction and networking of pre-existing and thermally induced cracks, resulting in microstructural damage before loading. We determined the crack closure stress, crack initiation stress, and crack damage stress under the respective temperatures by analyzing the stress-strain curves. An increase in temperature increased the crack closure stress and reduced the crack initiation stress, resulting in a decreased elastic range; the former increased by 12.1 MPa as the temperature increased from 20 °C to 250 °C, and the latter significantly reduced by 25.1 MPa. This finding suggests that the mechanical behavior of rocks or rock masses under high-temperature conditions, particularly at low-stress levels, is uncertain and cannot be approximated with standard material properties. No systemic relation was detected between temperature and crack damage stress; however, the volumetric strain at the crack damage stress increased consistently with temperature. [ABSTRACT FROM AUTHOR]

This article proposes a new control method for the synchronous rectifier (SR) of phase-shifted full-bridge (PSFB) converter to improve its efficiency in light-load condition. In general, the PSFB converter operates in the discontinuous conduction mode (DCM) in light-load condition to reduce the effective duty-ratio and core loss. However, the conventional control methods in the DCM cause undesirable conduction loss in SR because the output inductor current flows through the body-diode instead of the channel of SR. To figure it out, the proposed control method modulates the turn-on time of SR to eliminate the body-diode conduction. Moreover, it can be easily implemented without any auxiliary circuits. Therefore, it can improve the efficiency in light-load condition while keeping the advantages of DCM. The operating principle of PSFB converter in the DCM is first described. Thereafter, the proposed control method for SR is theoretically analyzed. Finally, its practical effectiveness is verified by experimental tests on the hardware implementation. [ABSTRACT FROM AUTHOR]

This article proposes a novel sawtooth-carrier based pulsewidth-modulation (SCPWM) method for quasi-Z-source inverter (qZSI) with the zero-voltage-switching (ZVS) operation to reduce the total harmonic distortion (THD) and inductor current ripple. The conventional variable-duty pulsewidth-modulation (VDPWM) method has been being used for qZSIs because it causes the low switching loss. However, this method has the limitation not only to improve the THD of output current but also to reduce the size of inductor when it is applied to the qZSI. To figure it out, the proposed SCPWM method uses the sawtooth-carrier signal while keeping the benefit from the use of variable duty. In particular, the ZVS operation occurs whenever the edge of sawtooth-carrier signal is located in the time interval of shoot-through state. This allows to increase the carrier frequency of qZSI without any additional switching loss. Thus, both the THD of output current and the inductor current ripple can be reduced while keeping the high efficiency of system. The operating principle of the proposed SCPWM method is first explained in detail. Thereafter, its performance is mathematically analyzed and compared with that of conventional VDPWM method. Finally, its practical effectiveness is verified by the hardware experimental test. [ABSTRACT FROM AUTHOR]

The output voltage of renewable energy sources is influenced by environmental conditions. To compensate for the variations of voltage, a buck–boost power conditioning system can be used. This article presents a full-bridge single-inductor-based buck–boost inverter. Its output voltage can be greater or lower than the input voltage depending on the controllable duty ratio. This inverter features bidirectional and reactive power flow operations with no high-frequency common-mode voltage. The unique feature of the proposed inverter is using a single inductor in the power train, which enhances the power density. Moreover, only two switches can operate at high frequency. This enables the inverter to be made with the high efficiency and simple circuit configuration. Based on the proposed full-bridge inverter, a novel cascaded buck–boost inverter is also presented. It retains all the benefits of the proposed full-bridge inverter. The theoretical analysis of the proposed full-bridge inverter is first explained in detail. It is then extended to a cascaded inverter. Thereafter, the practical effectiveness of the proposed inverters is verified with the experimental tests by implementing the hardware prototypes of 110 Vrms, 60 Hz, and 500 W for full-bridge single-inductor-based buck–boost inverter, and 220 Vrms, 60 Hz, and 1000 W for the cascaded inverter. [ABSTRACT FROM AUTHOR]

The use of potent therapies inhibiting critical oncogenic pathways active in epithelial cancers has led to multiple resistance mechanisms, including the development of highly aggressive, small cell neuroendocrine carcinoma (SCNC). SCNC patients have a dismal prognosis due in part to a limited understanding of the molecular mechanisms driving this malignancy and the lack of effective treatments. Here, we demonstrate that a common set of defined oncogenic drivers reproducibly reprograms normal human prostate and lung epithelial cells to small cell prostate cancer (SCPC) and small cell lung cancer (SCLC), respectively. We identify shared active transcription factor binding regions in the reprogrammed prostate and lung SCNCs by integrative analyses of epigenetic and transcriptional landscapes. These results suggest that neuroendocrine cancers arising from distinct epithelial tissues may share common vulnerabilities that could be exploited for the development of drugs targeting SCNCs. [ABSTRACT FROM AUTHOR]

Recently, microgrids have faced a great challenge for the stable operation of converter-dominant system with very high renewable penetration. The converter-based-generator reduces inertia constant. In this case, very small power imbalance can cause large frequency variation. Therefore, the accurate load sharing between generators is important for the stable operation. This paper proposes the virtual multi-slack (VMS) droop control based on the power sensitivity analysis. In other words, one physical slack generator directly controls the magnitude and phase angle of its bus voltage. At the same time, the other generators indirectly control the magnitudes and phase angles of their bus voltages by using the VMS droop control. This results in the proper load sharing between the generators in the stand-alone microgrid. That is, all nonslack generators operate as virtual slacks so that they solve the power imbalances together with one physical slack generator. The proposed VMS control is realized with the multi-slack power flow analysis, which enables adaptive droop based power allocation between the generators. Then, its effectiveness is verified with several case studies on the practical stand-alone microgrid in South Korea by using the electromagnetic transient program. [ABSTRACT FROM PUBLISHER]

This paper describes the development of a new buck cascaded buck–boost power factor correction (PFC) converter of 2 kW with a soft-switching technique. For its wide range of input voltage, it operates in both buck and boost modes. The parameters are properly selected to endure voltage and current stress in all operating ranges. In addition, the electromagnetic interference (EMI) filter is used to reduce the EMI noise and guarantee continuous input current in buck operation. Moreover, the zero-voltage-transient pulse-width-modulation (ZVT-PWM) method is applied to improve the overall efficiency of the converter. The performance of the proposed PFC converter with the widest range of input voltage is evaluated by the hardware experimental test including harmonics analysis based on the International Electrotechnical Commission standard in all operating ranges. Also, the variations of power factor are theoretically analyzed in both buck and boost modes to determine the widest input range of the proposed PFC converter of 2 kW with an EMI filter. These are strongly required to commercialize it in practice. Finally, the efficiency of proposed PFC converter is compared with that of a conventional buck cascaded buck–boost PFC converter under various conditions. [ABSTRACT FROM PUBLISHER]

We numerically model the thermal-hydrological-mechanical (THM) processes within the rock mass surrounding a cavern used for thermal energy storage (TES). We consider a cylindrical rock cavern with a height of 50 m and a radius of 10 m storing thermal energy of 350 °C as a conceptual TES model, and simulate its operation for thirty years. At first, the insulator performance are not considered for the purpose of investigating the possible coupled THM behavior of the surrounding rock mass; then, the effects of an insulator are examined for different insulator thicknesses. The key concerns are hydro-thermal multiphase flow and heat transport in the rock mass around the thermal storage cavern, the effect of evaporation of rock mass, thermal impact on near the ground surface and the mechanical behavior of the surrounding rock mass. It is shown that the rock temperature around the cavern rapidly increases in the early stage and, consequently, evaporation of groundwater occurs, raising the fluid pressure. However, evaporation and multiphase flow does not have a significant effect on the heat transfer and mechanical behavior in spite of the high-temperature (350 °C) heat source. The simulations showed that large-scale heat flow around a cavern is expected to be conduction-dominated for a reasonable value of rock mass permeability. Thermal expansion as a result of the heating of the rock mass from the storage cavern leads to a ground surface uplift on the order of a few centimeters, and to the development of tensile stress above the storage cavern, increasing the potentials for shear and tensile failures after a few years of the operation. Finally, the analysis shows that high tangential stress in proximity of the storage cavern can some shear failure and local damage, although large rock wall failure could likely be controlled with appropriate insulators and reinforcement. [ABSTRACT FROM AUTHOR]

Background and purpose Patients with human papillomavirus related (HPV+) head and neck cancers (HNCs) demonstrate improved clinical outcomes compared to traditional HPV negative (HPV−) HNC patients. We have recently shown that HPV+ HNC cells are more sensitive to radiation than HPV− HNC cells. However, roles of HPV oncogenes in regulating the response of DNA damage repair remain unknown. Material and methods Using immortalized normal oral epithelial cell lines, HPV+ HNC derived cell lines, and HPV16 E7-transgenic mice we assessed the repair of DNA damage using γ-H2AX foci, single and split dose clonogenic survival assays, and immunoblot. The ability of E7 to modulate expression of proteins associated with DNA repair pathways was assessed by immunoblot. Results HPV16 E7 increased retention of γ-H2AX nuclear foci and significantly decreased sublethal DNA damage repair. While phospho-ATM, phospho-ATR, Ku70, and Ku80 expressions were not altered by E7, Rad51 was induced by E7. Correspondingly, HPV+ HNC cell lines showed retention of Rad51 after γ-radiation. Conclusions Our findings provide further understanding as to how HPV16 E7 manipulates cellular DNA damage responses that may underlie its oncogenic potential and influence the altered sensitivity to radiation seen in HPV+ HNC as compared to HPV− HNC. [ABSTRACT FROM AUTHOR]

The smart inverter (SI) is an emerging technology, which enables the effective integration of distributed energy resources (DERs). Nevertheless, the operation by the only single SI function is not sufficient to deal with various conditions in a distribution system. In other words, all DERs are required to rapidly update the proper mode of SI functions depending on the system conditions. In this article, we propose the new active distribution management system (ADMS) for photovoltaic (PV)/energy storage system (ESS) integrated system based on the SI functions. It effectively regulates the system voltage, and it solves the line congestion problem in a distribution system by adaptively controlling the mode of SI functions. This method enables DER to effectively regulate its generation without the additional controllers. The effectiveness of the proposed ADMS is verified by several case studies on a practical distribution system in South Korea with the real measurements of generation from PV and load consumption based on the electromagnetic transient program. Also, the PV/ESS integrated system prototype of 100 kW is implemented for the experimental verification of the proposed ADMS. [ABSTRACT FROM AUTHOR]

Background: Since severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) was first reported in Wuhan, China, in December 2019, it has spread rapidly, and many coronavirus disease (COVID‐19) cases have occurred in Gwangju, South Korea. Viral mutations following the COVID‐19 epidemic have increased interest in the characteristics of epidemics in this region, and pathogen genetic analysis is required for infection control and prevention. Methods: In this study, SARS‐CoV‐2 whole‐genome analysis was performed on samples from patients with COVID‐19 in Gwangju from 2020 to 2022 to identify the trends in COVID‐19 prevalence and to analyze the phylogenetic relationships of dominant variants. B.41 and B.1.497 prevailed in 2020, the early stage of the COVID‐19 outbreak; then, B.1.619.1 mainly occurred until June 2021. B.1.617.2, classified as sublineages AY.69 and AY.122, occurred continuously from July to December 2021. Since strict measures to strengthen national quarantine management had been implemented in South Korea until this time, the analysis of mutations was also able to infer the epidemiological relationship between infection transmission routes. Since the first identification of the Omicron variant in late December 2021, the spread of infection has been very rapid, and weekly whole‐genome analysis of specimens has enabled us to monitor new Omicron sublineages occurring in Gwangju. Conclusions: Our study suggests that conducting regional surveillance in addition to nation‐level genomic surveillance will enable more rapid and detailed variant surveillance, which will be helpful in the overall prevention and management of infectious diseases. [ABSTRACT FROM AUTHOR]

The symmetry reduction of molecular shape of cationic chromophores as a design strategy to develop organic terahertz (THz) generators is used. Electron donating group (EDG) with an asymmetric shape is introduced into two types of cationic styryl‐quinolinium chromophores, leading to the development of several novel non‐centrosymmetric crystals with high macroscopic optical nonlinearity. In contrast, when an EDG with a symmetric shape is introduced, centrosymmetric crystal structure is obtained in all investigated crystals. For THz wave generation, crystals based on asymmetrically shaped EDG exhibit several optimal crystal characteristics, including a plate‐shape morphology, a large size, and an in‐plane polar axis. Furthermore, over the entire range of molecular phonon vibrations, 0.5–4 THz, the steric hindrance group in the asymmetrically shaped EDG has a strong influence on the suppression of THz phonon vibrations, leading to a low THz absorption coefficient. The crystals based on asymmetrically shaped EDG generate an ≈40 times stronger THz electric field than the inorganic ZnTe crystal and very broad THz spectra, extending up to 16 THz. Thus, the symmetry reduction of the molecular shape of cationic chromophores through the introduction of an asymmetrically shaped EDG is an effective design approach for the development of novel organic THz crystals. [ABSTRACT FROM AUTHOR]

The present study is aimed at developing a numerical model to reproduce coupled hydro-mechanical processes associated with fault reactivation by fluid injection in low permeability rock, as part of the DECOVALEX-2019 project Task B. We proposed a modeling approach for simulating the processes using the TOUGH-FLAC simulator, and modeled a fault reactivation experiment conducted at Mont Terri Rock Laboratory in Switzerland. The first step of the study involved benchmark calculations considering a simplified fault plane and geometry. Fluid flow along a fault was modeled using elements of aperture-sized thickness on the basis of Darcy's law and the cubic law in TOUGH2, whereas the mechanical behavior of a single fault was represented by zero-thickness interface elements in FLAC3D upon which a slip and/or separation is allowed. A methodology to connect a TOUGH2 volume element to a FLAC3D interface element was developed for handling the hydro-mechanical interactions on the fault during fluid injection. Two different fault models for describing the evolutions of hydraulic aperture by elastic fracture opening and failure-induced aperture increase were considered in the benchmark calculations. In the coupling process, the changes in geometrical features and hydrological properties induced by mechanical deformation were continuously updated. The transient responses of the fault and host rock to stepwise pressurization were examined during the simulation. The hydro-mechanical behavior, including the injection flow rate, pressure distribution around the borehole, stress conditions, and displacements in normal and shear directions were monitored in the surrounding rock and along the fault. The results of benchmark calculations suggest that the developed model reasonably represents the hydro-mechanical behavior of a fault and the surrounding rock. This modeling approach was applied to the fault reactivation experiment of the Mont Terri Rock Laboratory. In this interpretive modeling, a parametric study was conducted to examine the effects of input parameters regarding in situ stress and fault properties on the hydro-mechanical responses of the fault to water injection. Then, an optimal parameter set to reproduce the field experiment results was chosen by trial-and-error. The injection flow rate and pressure response during fault reactivation closely matched those obtained at the site, which indicates the capability of the model to appropriately capture the progressive pathway evolution during fault reactivation tests at the site. The anchor displacements were overestimated by the model, but a fair agreement was obtained in terms of the order of magnitude and the variation tendency. • We propose a modeling approach for fault activation using TOUGH-FLAC simulator. • Dual simulation of fault elements overcomes inherent problems from each method. • The model reasonably reproduces fault failure process and pathway evolution. [ABSTRACT FROM AUTHOR]

As renewable energy penetrates the power system, system operators are required to curtail output power from generation units to balance the power supply and demand. However, large curtailment from wind power plants (WPPs) may instantly cause excessive output power decrement, causing system frequency to drop significantly before reaching its nominal value. In order to solve this problem, this paper proposes a cooperative control framework to determine the operation of WPPs in two control methods, which are the stepwise inertial control (SIC) method and the curtailed control method. The proposed framework first determines the WPPs to operate in the curtailed control method to provide the required power curtailment. Next, it determines the WPPs to operate in the SIC method considering their releasable kinetic energy to provide an effective inertial response and compensate for the sudden excessive output power decrement caused by other WPPs operated in the curtailed control method. Therefore, each WPP is operated in one of two control methods to provide required power curtailment while reducing the sudden excessive output power decrement. To verify the effectiveness of the proposed cooperative control framework, several case studies are carried out on the practical South Korea electric power system. [ABSTRACT FROM AUTHOR]

The fire growth rate index (FIGRA), which is the ratio of the maximum value of the heat release rate (Qmax) and the time (tmax) to reach the maximum heat release rate, is a general method to evaluate a material in the fire-retardant performance in fire technology. The object of this study aims to predict FIGRA of the polyethylene foam pipe insulation in accordance with the scale factor (Sf), the volume fraction of the pipe insulation (VF) and the ignition heat source (Qig). The compartments made of fireboard have been mock-up with 1/3, 1/4, and 1/5 reduced scales of the compartment as specified in ISO 20632. The heat release rate data of the pipe insulation with the variation of Sf, VF, and Qig are measured from 33 experiments to correlate with FIGRA. Based on a critical analysis of the heat transfer phenomenon from previous research literature, the predictions of Qmax and tmax are presented. It is noticeable that the fire-retardant grade of the polyethylene foam pipe insulation could have Grade B, C, and D in accordance with the test conditions within ±15% deviation of the predicted FIGRA. In case of establishing the database of various types of insulation, the prediction models could apply to evaluate the fire-retardant performance. [ABSTRACT FROM AUTHOR]

This study investigated the prevalence of Orientia tsutsugamushi, Anaplasma phagocytophilum, and Leptospira interrogans in wild rodents through molecular detection using organ samples and through serological assay using blood samples of mice collected from two distinct sites in Gwangju Metropolitan City, Republic of Korea (ROK). A total of 47 wild rodents, identified as Apodemus agrarius (A. agrarius), were captured from June to August 2016. The seroprevalence of antibodies against bacterial pathogens in A. agrarius sera was analyzed; 17.4% (8/46) were identified as O. tsutsugamushi through indirect immunofluorescence assay and 2.2% (1/46) were identified as Leptospira species through passive hemagglutination assay. Using polymerase chain reaction, the spleen, kidney and blood samples were investigated for the presence of O. tsutsugamushi, A. phagocytophilum, and L. interrogans. Out of the 47 A. agrarius, 19.1% (9/47) were positive for A. phagocytophilum and 6.4% (3/47) were positive for L. interrogans, while none were positive for O. tsutsugamushi. Four out of 46 (8.7%) blood samples, six out of 45 (13.3%) spleen samples, and one out of 47 (2.1%) kidney samples were positive for A. phagocytophilum. Three out of 47 (6.4%) kidney samples were positive for L. interrogans. The sequencing results of PCR positive samples demonstrated > 99% similarity with A. phagocytophilum and L. interrogans sequences. A. phagocytophilum was mostly detected in the spleen, whereas L. interrogans was mostly detected in the kidneys. Notably, A. phagocytophilum and L. interrogans were detected in A. agrarius living in close proximity to humans in the metropolitan suburban areas. The results of this study indicate that rodent-borne bacteria may be present in wild rodents in the metropolitan suburban areas of ROK. [ABSTRACT FROM AUTHOR]

In South Korea, the stand-alone microgrid on an island has synchronous diesel generators and multiple distributed generations (DG) based on renewable energy, and energy storage systems (ESS). According to the active policy of government to develop eco-friendly microgrids with zero carbon emission, many diesel generators in stand-alone microgrids are being replaced by the DGs. It brings challenges on the operation and control of multiple DGs because this causes the lack of inertia, which is originally provided from the diesel generators. [ABSTRACT FROM AUTHOR]

This paper proposes the new clamping angle control (CAC) pulse width modulation (PWM) method to restore its maximum linear modulation range of voltage source inverters (VSIs) reduced by the duty ratio limitation in hardware implementation, which makes the VSIs to operate nonlinearly in the high modulation range. The deadtime and the bootstrap gate driver circuit mainly cause this duty ratio limitation in practice. In particular, the bootstrap gate driver circuit is used in many industrial applications by avoiding the additional power supply to apply the gate-source voltage of power switches, and therefore making the VSIs to be small size with the low cost. First, the proposed CACPWM method is theoretically analyzed. Then, it is applied in the high modulation range to overcome the limitation of the duty ratio due to the use of the bootstrap gate driver circuit. Thereafter, its practical effectiveness is verified by both simulation and experimental tests. Also, the resulting harmonic distortions are compared with those by the conventional PWM methods. [ABSTRACT FROM AUTHOR]

The inertia-free stand-alone (IFSA) microgrid is the new small power grid without synchronous generators equipped in conventional power systems. In other words, this system has the only converter-based generators (CBGs) based on energy storage devices and renewable energies. Therefore, it requires a new CBG control to provide strong voltage reference for the CBGs connected to the point of common coupling (PCC). This is because the IFSA microgrid is subject to a weak system such that it cannot maintain its rated frequency and/or bus voltage with the conventional real and reactive power controllers, which usually get their references from the PCC. This paper proposes the innovative conceptual approach for distributed coordination in the IFSA microgrid by applying the synchronized global positioning system time to the CBGs. Moreover, it is verified that the proposed physical structure of the IFSA microgrid makes it possible for all CBGs to share the real and reactive powers effectively. As the result, the proposed CBG control can provide the robustness, which is strongly required in the IFSA microgrid, based on timely outage management and restoration process. Several case studies are carried out with the microgrid of 36 MW to verify the effectiveness of the proposed CBG controller. The simulation and hardware-in-the loop tests are carried out using the power system computer-aided design/electromagnetic transient design and control (PSCAD/EMTDC) and the real-time digital power system simulator (RTDS), respectively. [ABSTRACT FROM AUTHOR]

The kinetic energy stored in the rotating mass of wind turbine generators can provide the effective power quality solution to the inertia-free stand-alone (IFSA) microgrid by improving its stability. In conventional power systems, the power released from the inertia of synchronous generators regulates the system frequency. However, the frequency does not vary much even when a large disturbance or a load change occurs in the IFSA microgrid with only converter-based generators. This paper proposes a new inertia control method for a type-4 permanent magnet synchronous generator wind turbine system in the IFSA microgrid by utilizing the measurement of the dc-link voltage of the converter and its derivatives, not by the system frequency. Several case studies are carried out to evaluate the performance of the proposed inertia control in the IFSA microgrid with electromagnetic transients program-based simulation. Also, its effectiveness is verified with the experimental results from the hardware-in-the-loop test implemented by the controller interface with the digital signal processor, which is connected to the real-time digital simulator. [ABSTRACT FROM AUTHOR]

Zolbetuximab, a monoclonal antibody targeting claudin-18 isoform 2 (CLDN18.2), has shown efficacy in patients with CLDN18.2-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma. We report the results of the SPOTLIGHT trial, which investigated the efficacy and safety of first-line zolbetuximab plus mFOLFOX6 (modified folinic acid [or levofolinate], fluorouracil, and oxaliplatin regimen) versus placebo plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma. SPOTLIGHT is a global, randomised, placebo-controlled, double-blind, phase 3 trial that enrolled patients from 215 centres in 20 countries. Eligible patients were aged 18 years or older with CLDN18.2-positive (defined as ≥75% of tumour cells showing moderate-to-strong membranous CLDN18 staining), HER2-negative (based on local or central evaluation), previously untreated, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma, with radiologically evaluable disease (measurable or non-measurable) according to Response Evaluation Criteria in Solid Tumors version 1.1; an Eastern Cooperative Oncology Group performance status score of 0 or 1; and adequate organ function. Patients were randomly assigned (1:1) via interactive response technology and stratified according to region, number of organs with metastases, and previous gastrectomy. Patients received zolbetuximab (800 mg/m2 loading dose followed by 600 mg/m2 every 3 weeks) plus mFOLFOX6 (every 2 weeks) or placebo plus mFOLFOX6. The primary endpoint was progression-free survival assessed by independent review committee in all randomly assigned patients. Safety was assessed in all treated patients. The study is registered with ClinicalTrials.gov , NCT03504397 , and is closed to new participants. Between June 21, 2018, and April 1, 2022, 565 patients were randomly assigned to receive either zolbetuximab plus mFOLFOX6 (283 patients; the zolbetuximab group) or placebo plus mFOLFOX6 (282 patients; the placebo group). At least one dose of treatment was administered to 279 (99%) of 283 patients in the zolbetuximab group and 278 (99%) of 282 patients in the placebo group. In the zolbetuximab group, 176 (62%) patients were male and 107 (38%) were female. In the placebo group, 175 (62%) patients were male and 107 (38%) were female. The median follow-up duration for progression-free survival was 12·94 months in the zolbetuximab group versus 12·65 months in the placebo group. Zolbetuximab treatment showed a significant reduction in the risk of disease progression or death compared with placebo (hazard ratio [HR] 0·75, 95% CI 0·60–0·94; p=0·0066). The median progression-free survival was 10·61 months (95% CI 8·90–12·48) in the zolbetuximab group versus 8·67 months (8·21–10·28) in the placebo group. Zolbetuximab treatment also showed a significant reduction in the risk of death versus placebo (HR 0·75, 95% CI 0·60–0·94; p=0·0053). Treatment-emergent grade 3 or worse adverse events occurred in 242 (87%) of 279 patients in the zolbetuximab group versus 216 (78%) of 278 patients in the placebo group. The most common grade 3 or worse adverse events were nausea, vomiting, and decreased appetite. Treatment-related deaths occurred in five (2%) patients in the zolbetuximab group versus four (1%) patients in the placebo group. No new safety signals were identified. Targeting CLDN18.2 with zolbetuximab significantly prolonged progression-free survival and overall survival when combined with mFOLFOX6 versus placebo plus mFOLFOX6 in patients with CLDN18.2-positive, HER2-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma. Zolbetuximab plus mFOLFOX6 might represent a new first-line treatment in these patients. Astellas Pharma, Inc. [ABSTRACT FROM AUTHOR]

This paper proposes a computationally effective method for optimal operation of multiple distributed generations (DGs) in dc distribution systems to improve their efficiency. There have been many research works to select the optimal sizes of multiple DGs. However, these optimal sizes are valid only in the particular operating point. For optimal operations of power systems, the DG sizes must be determined all the time according to the various load conditions. The proposed method can maintain the distribution system operating in its optimal condition with only single optimization process, without regard to load variations. Therefore, it can moderate the serious problems, derived from inaccurate load forecasting. To verify the performance of the proposed method, the dc system is first implemented with the real distribution system of Do-gok area in Seoul, Korea. Then, the real hourly-load data, acquired from SCADA system in Korea, are used to simulate the practical load variations. [ABSTRACT FROM PUBLISHER]

Like conventional two-switch leg converters, the three-switch leg converters also have short-circuit risks and a dangerous shoot-through current is generated if switches of the same leg are turned on simultaneously. In this article, a new dual-buck structure is proposed for three-switch leg converters. The proposed structure is reliable because of no shoot-through concerns and high quality of output waveforms can be obtained due to the reduction in pulsewidth modulation deadtime. Unlike the conventional dual-buck three-switch leg that uses many passive components such as four current limiting inductors and three external diodes, the new dual-buck three-switch leg uses only one current limiting inductor with two external diodes. To verify the performance, the proposed three-switch legs are used in single-phase dual-output inverter and detailed theoretical analysis, simulation, and experiments are performed. Both continuous and discontinuous modulation schemes are applied and it has been figured out that discontinuous modulation scheme can improve the dc-link voltage utilization in the common-frequency mode of operation. [ABSTRACT FROM AUTHOR]

We developed a geothermal monitoring system with an open-source Internet of Things (IoT) system. The study's objective is to achieve an economical alternative solution to the expensive commercial data loggers, local PC-based control, data storage limitation, the number of sensor connections, and secure data transmission over the Internet in a decentralized renewable energy system. The developed system consists of hardware and software customized with open-source support that helps resolve the conventional limitations that the commercial system inherently has. We have applied the system to a geothermal energy system deployed at a residential care facility for the elderly in Chuncheon, South Korea. The proposed system enabled us to acquire the data of temperature and fluid flow in real-time and for a prolonged period (i.e., years) at an affordable price compared to installing a conventional data-acquisition system. The real-time multi-year-long data helped confirm seasonality in heating and cooling. We can also apply the same proposed system to the other renewable energy systems monitoring temperature, pressure, wind speed, displacement, noise, seismicity, etc. • Development of a geothermal monitoring system with an open-source IoT system. • The system was applied to a geothermal system deployed at a residential care facility. • The real-time multi-year-long data helped confirm seasonality in heating and cooling. • We can also apply the same proposed system to the other renewable energy. [ABSTRACT FROM AUTHOR]

Background: Hemorrhagic fever with renal syndrome (HFRS) caused by hantaviruses is a frequently reported acute hemorrhagic fever in South Korea. These viruses are transmitted by various rodent species such as Apodemus agrarius. Methodology/Principal findings: To investigate hantavirus infection and seroprevalence in rodents, wild rodents were captured from two districts in the suburbs of Gwangju Metropolitan City from January 2016 to December 2018. Nested reverse-transcription polymerase chain reaction (RT-PCR) targeting the hantavirus-specific L segment and indirect immunofluorescence antibody (IFA) assay using Hantaan virus antigen slides were performed. A total of 585 wild rodents were captured—512 A. agrarius, 49 Crocidura lasiura, and 24 Myodes regulus. Nested RT-PCR was performed to examine the rate of hantavirus infection in wild rodents, and 1.88% (11/585) of all rodents, 1.17% (6/512) of A. agrarius, 6.12% (3/49) of C. lasiura, and 8.33% (2/24) of M. regulus tested positive. The nucleotide sequence analysis of the eleven PCR-positive products revealed that six PCR products showed over 85% sequence similarity with the Jeju virus, four showed over 99.7% similarity with the Hantaan virus, and one showed over 95.3% homology with the Imjin virus. Moreover, IgG antibodies against the Hantaan virus were detected in 6.15% (36/585) of all rodents, 6.8% (35/512) of A. agrarius, and 4.17% (1/24) of M. regulus. IgG antibodies were not detected in C. lasiura. Conclusions/Significance: Hantaviruses were detected in all three wild rodent species of A. agrarius, C. lasiura, and M. regulus captured in the suburbs of Gwangju Metropolitan City, South Korea, and it was demonstrated that they were various strains of hantaviruses such as the Hantaan, Jeju, and Imjin viruses. Author summary: Hantaviruses (family Hantaviridae, genus Hantavirus) are rodent viruses that can cause two fatal human diseases—hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. These viruses are transmitted by various rodent species such as Apodemus agrarius. In the present study, wild rodents captured in the suburbs of Gwangju Metropolitan City were analyzed by nested reverse-transcription polymerase chain reaction targeting the hantavirus-specific L segment and indirect immunofluorescence antibody assay using Hantaan virus antigen slides. A total of 585 wild rodents were captured and 1.88% (11/585) of all rodents, 1.17% (6/512) of A. agrarius, 6.12% (3/49) of Crocidura lasiura, and 8.33% (2/24) of Myodes regulus were PCR-positive. Of the eleven PCR-positive wild rodents, six PCR products showed over 85% sequence similarity with the Jeju virus, four showed over 99.7% similarity with the Hantaan virus, and one showed over 95.3% homology with the Imjin virus. Moreover, IgG antibodies against the Hantaan virus were detected in 6.15% (36/585) of all rodents, 6.8% (35/512) of A. agrarius, and 4.17% (1/24) of M. regulus. IgG antibodies were not detected in C. lasiura. When we examined the detection rate of hantavirus genes in different seasons, hantaviruses were most commonly detected in fall (seven cases [5.69%]) and winter (four cases [2.76%]). No hantaviruses were detected in spring or summer. However, the seasonal prevalence of IgG antibodies was higher in spring and summer (12 [7.32%] and 11 [7.10%] cases, respectively) than in fall and winter (seven [5.69%] and six [4.14%] cases, respectively). This study was performed on a monthly basis throughout a three-year period, and thus, it provides reliable data that may provide insight into preventive measures against HFRS. Our results suggest that various types of hantaviruses, including Hantaan, Jeju, and Imjin viruses, are distributed throughout Gwangju Metropolitan City, South Korea. Data regarding the rate of Hantaan virus infection in rodents in Gwangju and knowledge of the hantavirus seroprevalence, species, and genotypes circulating in these domestic rodent species will provide useful information for developing vaccines and diagnostic testing using sequence data. These will help increase preparedness for the emergence of new species. [ABSTRACT FROM AUTHOR]

This article proposes the new noninverting buck–boost ac–ac converter, which can minimize the reverse recovery loss by disabling the body diodes of switches and using the external fast recovery diodes for its current freewheeling. In particular, the proposed ac–ac converter takes advantages of metal-oxide semiconductor field effect transistors and external fast recovery diodes to achieve the high efficiency. Also, it has the high reliability without the shoot-through and dead-time considerations in the circuit. Moreover, it can be simply implemented without employing the conventional commutation control. This results in decreasing the control complexity. As its proper application, a new type of dynamic voltage restorer (DVR) based on the proposed noninverting buck–boost converter is described. It enables to solve the voltage sag and swell problems by utilizing both positive and negative gains of converter. Then, the hardware prototype of proposed ac–ac converter and DVR are implemented to verify their practical effectiveness. [ABSTRACT FROM AUTHOR]

In this article, we present a new type of Z-source inverter (ZSI) that replaces two inductors in the original quasi-ZSI with two transformers. It can produce a very high output voltage with the high value of the modulation index. Moreover, it enables both to provide a better power quality of output and to reduce the switching loss. In particular, the proposed quasi-clamped ZSI with two transformers give a unique solution to obtain high gain by reducing the turns ratio, rather than increasing it. Also, the leakage inductance of the transformer might cause huge voltage spikes across the inverter bridge. To deal with this problem, an effective clamping technique is proposed. As a result, this increases the overall efficiency of the system by utilizing the low-power switching devices. The characteristics of the proposed quasi-clamped ZSI with two transformers are comprehensively discussed with the detailed theoretical analysis. Thereafter, its performances are evaluated by both simulation and experimental tests. [ABSTRACT FROM AUTHOR]

Lyme disease is a tick-borne infectious disease caused by the Borrelia burgdorferi sensu lato complex. However, the distribution of Borrelia genospecies and the tissue detection rate of Borrelia in wild rodents have rarely been investigated. Here, we studied 27 wild rodents (Apodemus agrarius) captured in October and November 2016 in Gwangju, South Korea, and performed nested polymerase chain reaction targeting pyrG and ospA to confirm Borrelia infection. Eight rodents (29.6%) tested positive for Borrelia infection. The heart showed the highest infection rate (7/27; 25.9%), followed by the spleen (4/27; 14.8%), kidney (2/27; 7.4%), and lungs (1/27; 3.7%). The B. afzelii infection rate was 25.9%, with the highest rate observed in the heart (7/27; 25.9%), followed by that in the kidney and spleen (both 2/27; 7.4%). B. garinii and B. burgdorferi sensu stricto were detected only in the spleen (1/27; 3.7%). This is the first report of B. burgdorferi sensu stricto infection in wild rodents in South Korea. The rodent hearts showed a high B. afzelii infection rate, whereas the rodent spleens showed high B. garinii and B. burgdorferi sensu stricto infection rates. Besides B. garinii and B. afzelii, B. burgdorferi sensu stricto may cause Lyme disease in South Korea. [ABSTRACT FROM AUTHOR]

This article proposes a family of single-phase transformer based Z-source ac–ac converters (ZSACs). The proposed converters inherit all the benefits associated with the classical single-phase ZSAC, which are providing the buck–boost operation, maintaining or reversing the phase angle, and improving reliability. The proposed converters also have the improved input profile, continuous input current, and shared ground between input and output. Moreover, they use the turns ratio of transformers to produce the required voltage gain, which can be tuned by either increasing or decreasing the turns ratio of transformer depending on the configuration of Z-source structure. A safe-commutation strategy is also presented to achieve the soft commutation, which eliminates the voltage and current spikes without any additional snubber circuits. The features of proposed converters are comprehensively discussed with the detailed theoretical analysis. Thereafter, its performances are evaluated by both simulation and experimental tests. [ABSTRACT FROM AUTHOR]

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease. SFTS is caused by the SFTS virus, a novel phlebovirus, and is spread by ticks. Methods: A 50-year-old man was admitted to our hospital with the chief complaint of fever and was diagnosed with confirmed SFTS. An epidemiological investigation was conducted, and immunofluorescent antibody assays (IFAs) were performed to determine the role of the patient's three dogs in the transmission. PCR assays were performed using ticks that were collected with the dragging and flagging method from the patient's dogs and home. Results: PCR results were positive, and IFA confirmed an increased antibody titer. Although the reverse transcription PCR results of the three dogs were negative for SFTS virus, one dog had an elevated SFTS IFA immunoglobulin G (IgG) titer of 1:1,024. Moreover, a number of ticks were observed in the area surrounding the dog cages. Based on the findings of the patient interview, the patient was likely to have acquired SFTS by blood splash because he removed or burst ticks from the dogs with his bare hands. Although no tick bites were reported, tick transmission could not be ruled out. Studies have shown that only one in three individuals with a diagnosis of SFTS recalls a tick bite; thus, a definite exclusion of tick transmission in this case was not possible. Conclusions: The epidemiological findings of our case suggest a possible relationship between tick infestation in domestic dogs and SFTS virus transmission to humans. However, there is no direct evidence supporting this viral transmission route. Future studies are needed to further investigate a potential route of SFTS transmission by exposure to engorged tick blood or pet dogs. [ABSTRACT FROM AUTHOR]

Small cell carcinoma of the bladder (SCCB) is a rare and lethal phenotype of bladder cancer. The pathogenesis and molecular features are unknown. Here, we established a genetically engineered SCCB model and a cohort of patient SCCB and urothelial carcinoma samples to characterize molecular similarities and differences between bladder cancer phenotypes. We demonstrate that SCCB shares a urothelial origin with other bladder cancer phenotypes by showing that urothelial cells driven by a set of defined oncogenic factors give rise to a mixture of tumor phenotypes, including small cell carcinoma, urothelial carcinoma, and squamous cell carcinoma. Tumor-derived single-cell clones also give rise to both SCCB and urothelial carcinoma in xenografts. Despite this shared urothelial origin, clinical SCCB samples have a distinct transcriptional profile and a unique transcriptional regulatory network. Using the transcriptional profile from our cohort, we identified cell surface proteins (CSPs) associated with the SCCB phenotype. We found that the majority of SCCB samples have PD-L1 expression in both tumor cells and tumor-infiltrating lymphocytes, suggesting that immune checkpoint inhibitors could be a treatment option for SCCB. We further demonstrate that our genetically engineered tumor model is a representative tool for investigating CSPs in SCCB by showing that it shares a similar a CSP profile with clinical samples and expresses SCCB-up-regulated CSPs at both the mRNA and protein levels. Our findings reveal distinct molecular features of SCCB and provide a transcriptional dataset and a preclinical model for further investigating SCCB biology. [ABSTRACT FROM AUTHOR]

Numerical simulations become a necessity when experimental approaches cannot cover the required physical and time scale of interest. One of such area is a simulation of long-term host rock behaviors for nuclear waste disposal and simulation tools involved in the assessment must go through rigorous validation tests. The DECOVALEX project (Development of COupled models and their VAlidation against EXperiments) is dedicated to this purpose by international participants. a a www.decovalex.org. This work is part of the ongoing phase DECOVALEX–2023 (D–2023, Task G) particularly aiming to simulate fracture behaviors under various conditions. Here, we cross-verified a variety of numerical methods including continuous and discontinuous approaches against four benchmark exercises with emphasis on numerical accuracy and parameterization of the various numerical approaches. The systematic inter-comparisons of test cases highlight advantages and disadvantages of the different numerical models. Numerical details on discretization effects (e.g. mesh density and orientation) and domain size were investigated in detail for practical applications. It became evident that meticulous attention to mesh resolution and domain size is imperative for achieving accurate numerical simulations, even for static cracks. Moreover, when comparing numerical methods to closed-form solutions for static cracks, all models successfully reproduced the maximum crack opening but encountered challenges near the crack tips. Finally, the paper discusses how to convert between and therefore compare parameters of various numerical approaches. Our benchmark studies reveal that each model necessitates a distinct number of parameters, even in simple scenarios like static crack aperture benchmarks. It is generally more practical to employ fewer parameters to mitigate model over-parameterization and enhance experimental feasibility. • Systematic benchmarks on numerical accuracy & parameterizations for hydro-mechanical fracture mechanics. • Study explores discretization effects and domain size in practical applications. • Compare various numerical approaches' parameterizations. [ABSTRACT FROM AUTHOR]

The high penetration of distributed energy resources (DERs) in the distribution system brings new challenges related to voltage variations and reverse power flow. The sudden changes in electric power generation from the DERs due to climate conditions or their internal malfunction might cause high fluctuations in system voltage. To enhance the voltage stability when a disturbance occurs, this paper proposes a new reactive power management method to control each DER based on voltage sensitivity analysis. The voltage variation has the different features in both steady-state and transient conditions. In particular, its transient behavior depends on the type of DERs. Therefore, the particular optimal control for improving the dynamic response of voltage is difficult to apply for all types of DERs. In contrast, the voltage variation in steady-state can be controlled with the reactive power management by the sensitivity analysis between reactive power generation and system voltage. Even though this paper focuses on the reduction of voltage variation in steady-state, the relationship between the voltage variations in steady-state and transient conditions is also analyzed. The effectiveness of the proposed method is verified with several case studies on the practical distribution system in South Korea by using the time-domain simulation based on the PSCAD/EMTDC® software. The results show that the proposed reactive power management method can improve the dynamic voltage responses in both steady-state and transient conditions when the distribution system has the high penetration of renewables. [ABSTRACT FROM AUTHOR]

In South Korea, the existing diesel generators are being replaced with renewable energy sources (RESs) in several stand-alone microgrids. However, their reliability and stability are not still guaranteed by fluctuations of the system caused by RESs, arising from unpredictable changes in environmental factors. Moreover, since the inertia that is originally provided by the diesel synchronous generators is reduced, the overall system becomes highly sensitive to frequency variations. As a result, the installation of RESs must be well planned while considering the upper limit of their installed capacity. In this paper, a new method for evaluating the maximum penetration capacity of photovoltaic (PV) generators to ensure the stable operation of a microgrid is proposed. For the analytical approach, two frequency stability indexes, which are the minimum instantaneous frequency and the quasi-steady-state (QSS) frequency after a disturbance, are used. The capacity of PV to be installed is limited by considering the characteristics of other generators. In addition, the efficiency of the energy storage system (ESS) is also analyzed to determine the optimal capacity of both PV and ESS. The effectiveness of the proposed method is firstly proven through the mathematical analysis. Then, case studies on a practical stand-alone microgrid in South Korea are carried out using a time-domain simulation based on the DIgSILENT PowerFactory® software. [ABSTRACT FROM AUTHOR]

Background: This study investigated Borrelia species prevalence in ticks from vegetation, through a molecular method, in Gwangju Metropolitan City, South Korea. Methodology/Principal findings: A total of 484 ticks were collected through flagging and dragging in a suburban area of Gwangju Metropolitan City, South Korea, in 2014. These ticks were morphologically identified and subjected to nested PCR, targeting Borrelia–specific CTP synthase (pyrG), outer surface protein A (ospA) and flagellin (flaB) genes. Molecular biological species identification of Borrelia-positive ticks was conducted via 16S rRNA PCR assays. Of the 484 ticks collected, 417 (86.2%) were identified as Haemaphysalis longicornis, 42 (8.7%) as H. flava, and 25 (5.2%) as Ixodes nipponensis. All the ixodid ticks containing Borrelia species bacteria were confirmed to be I. nipponensis adults, by both morphological and molecular methods. Of the 25 I. nipponensis ticks collected, four (16%) were positive for Borrelia species, three of which were B. afzelii and one B. miyamotoi. Conclusions/Significance: Our study has shown the harboring of B. miyamotoi by I. nipponensis in South Korea. Morphological and molecular genetic analyses revealed that, in South Korea, I. nipponensis could potentially transmit B. miyamotoi to humans. [ABSTRACT FROM AUTHOR]

Many pathogens causing hemorrhagic fevers of medical and veterinary importance have been identified and isolated from rodents in the Republic of Korea (ROK). We investigated the occurrence of emerging viruses causing hemorrhagic fevers, such as hemorrhagic fever with renal syndrome (HFRS), severe fever with thrombocytopenia syndrome (SFTS), and flaviviruses, from wild rodents. Striped field mice, Apodemus agrarius (n = 39), were captured during 2014–2015 in the south-west of ROK. Using molecular methods, lung samples were evaluated for SFTS virus, hantavirus, and flavivirus, and seropositivity was evaluated in the blood. A high positive rate of hantavirus (46.2%) was detected in A. agrarius lungs by reverse transcription-nested polymerase chain reaction (RT-N-PCR). The monthly occurrence of hantavirus was 16.7% in October, 86.7% in November, and 25% in August of the following year (p < 0.001). Moreover, 17.9% of blood samples were serologically positive for hantavirus antibodies. The most prevalent strain in A. agrarius was Hantaan virus. All samples were positive for neither SFTS virus nor flavivirus. Hantaan virus was detected in 86.7% of A. agrarius in November (autumn), and thus, virus shedding from A. agrarius can increase the risk of humans contracting HFRS. These findings may help to predict and prevent disease outbreaks in ROK. [ABSTRACT FROM AUTHOR]

Candidatus Neoehrlichia mikurensis (Ca. N. mikurensis; family Anaplasmataceae) is an emerging tick-borne pathogen that causes a systemic inflammatory syndrome with thrombotic complications. We report here the first identification of Ca. N. mikurensis in organ samples from small mammals captured in southwest South Korea. Nested PCR of groEL and 16S rRNA genes was used to confirm the identity of the bacteria present, and successfully amplified fragments were sequenced. All captured animals were identified as striped field mice (Apodemus agrarius), approximately 28.6% (4/14) and 21.4% (3/14) of which were found to be PCR-positive for Ca. N. mikurensis and Anaplasma phagocytophilum, respectively. The detection of Ca. N. mikurensis in these animals represents the first evidence of this pathogen in South Korea. Carriage of this bacterium by rodents highlights the need for more detailed investigation of their role in its transmission to humans. [ABSTRACT FROM AUTHOR]

This paper analyzes the effect of a resistive superconducting fault current limiter (R-SFCL) applied to an isolated microgrid with a dynamic load model. The isolated microgrid with high penetration of distributed generators (DGs) is vulnerable to faults in aspect of frequency stability. For the more accurate analysis of the isolated microgrid, the dynamic composite load model, which consists of a static part with the constant impedance—current–power model and a dynamic part with the high-order induction motor model, is applied in this study. The R-SFCL in isolated microgrid can effectively mitigate the fault current by rapidly providing protection during the fault as well as improve the transient stability by using the fast response characteristics of the R-SFCL as a transition signal for the DG. To evaluate the performance of the proposed model, a case study is carried out by a time-domain simulation based on the DIgSILENT PowerFactory software [ABSTRACT FROM PUBLISHER]

Increase in power demand has required providing infrastructure, such as huge power plants and transmission lines. However, the recent trends in power system planning and operation are being toward maximum utilization of existing electricity infrastructure with tight operating margins because of new constraints placed by economic, political, and environmental issues. This might cause serious stability problems when a severe fault or a sudden outage of critical lines occurs. Therefore, the special protection scheme (SPS) has been used by generator tripping and successive load shedding to prevent a large-scale blackout by the cascading effect. If the number of tripping generators in the SPS operation is reduced, the enormous cost of power outage can be saved. This paper analyzes the enhancement of SPS via the transient stability improvement by the static synchronous compensator (STATCOM) applied to a generation side of Korea electric power system. First, its characteristic related to the SPS is described. Then, the proper capacity of STATCOM is determined with the equal area criterion to reduce the number of tripping generators. Also, the new control method for STATCOM is proposed for its full utilization. Finally, its effectiveness is verified by the case study with the practical data of Korea electric power system. [ABSTRACT FROM AUTHOR]

The incidence rate for scarlet fever in South Korea is rising. During 2008-2015, we collected group A Streptococcus isolates and performed emm and exotoxin genotyping and disk-diffusion antimicrobial tests. Scarlet fever in South Korea was most closely associated with emm types emm4, emm28, emm1, and emm3. In 2015, tetracycline resistance started increasing. [ABSTRACT FROM AUTHOR]

This paper proposes a torque limit-based inertial control scheme of a doubly-fed induction generator (DFIG) that supports the frequency control of a power system. If a frequency deviation occurs, the proposed scheme aims to release a large amount of kinetic energy (KE) stored in the rotating masses of a DFIG to raise the frequency nadir (FN). Upon detecting the event, the scheme instantly increases its output to the torque limit and then reduces the output with the rotor speed so that it converges to the stable operating range. To restore the rotor speed while causing a small second frequency dip (SFD), after the rotor speed converges the power reference is reduced by a small amount and maintained until it meets the reference for maximum power point tracking control. The test results demonstrate that the scheme can improve the FN and maximum rate of change of frequency while causing a small SFD in any wind conditions and in a power system that has a high penetration of wind power, and thus the scheme helps maintain the required level of system reliability. The scheme releases the KE from 2.9 times to 3.7 times the Hydro-Québec requirement depending on the power reference. [ABSTRACT FROM PUBLISHER]

Summary MYCN amplification and overexpression are common in neuroendocrine prostate cancer (NEPC). However, the impact of aberrant N-Myc expression in prostate tumorigenesis and the cellular origin of NEPC have not been established. We define N-Myc and activated AKT1 as oncogenic components sufficient to transform human prostate epithelial cells to prostate adenocarcinoma and NEPC with phenotypic and molecular features of aggressive, late-stage human disease. We directly show that prostate adenocarcinoma and NEPC can arise from a common epithelial clone. Further, N-Myc is required for tumor maintenance, and destabilization of N-Myc through Aurora A kinase inhibition reduces tumor burden. Our findings establish N-Myc as a driver of NEPC and a target for therapeutic intervention. [ABSTRACT FROM AUTHOR]

This paper proposes a computationally efficient technique for estimating the composite load model parameters based on analytical similarity of parameter sensitivity. When the model parameters are updated in the optimization procedure to best fit the actual load dynamics, i.e., measurements, parameters of similar sensitivity representation in the given mathematical model structure are updated in the same manner at every iterative step. This research allows for practically reducing the number of load model parameters to be identified in the estimation process and the overall computational cost while preserving the desired complexity and accuracy of the original model. This approach consequently facilitates the parameter estimation in the optimization process and helps manage increased number of parameters often criticized for adopting the dynamic composite load model via measurement-based approach. Case studies for the real power system demonstrate the computational efficiency and intact accuracy of the proposed method with reference to the existing methods of estimating all the parameters of the given composite load model independently. [ABSTRACT FROM AUTHOR]

This paper proposes the new energy management method based on the photovoltaic (PV) hybrid power conditioning system of 4 kW with an energy storage device (ESD). The use of the ESD such as a lithium-ion battery improves the energy efficiency of the overall system depending on time and weather conditions. In addition, the proposed system provides the new function for energy management in real time without weather forecasting while it considers the power generations from the PV system, residential load variations, and electricity price. In other words, the proposed energy management system (EMS) can reduce the electricity price by charging the energy of nighttime electric power. In addition, it can suppress the grid voltage variations caused by the large amount of PV generations during daytime with respect to relatively less load demand. The performances of the proposed EMS system based on the 4-kW PV HPCS with a lithium-ion battery are evaluated by time-domain simulation. Thereafter, the experimental prototype is implemented in hardware to verify the usefulness of the proposed system. [ABSTRACT FROM PUBLISHER]

The high penetration of wind power decreases the system inertia and primary frequency reserve while replacing the conventional synchronous generators (SGs). Therefore, if the system operator does not take appropriate action on the remaining generation units (GUs) operation, high penetration of wind power will aggravate the frequency stability. To solve this problem, wind power plants (WPPs) may provide the inertial response and primary frequency response (PFR) to support the frequency stability. However, due to the variability of renewable energy, WPPs may not provide adequate frequency response whenever it is required. This paper proposes an algorithm to determine the operation of GUs to provide appropriate PFR for a power system with high penetration of wind power. Through the proposed algorithm, it calculates the required PFR to restore the decreased frequency stability caused by the high penetration of wind power. Then, while considering the available PFR from WPPs, it redetermines the droop coefficient of SGs governor to provide the sufficient PFR to recover the frequency stability. Finally, the effectiveness of the proposed algorithm is verified on the practical Korean electric power system. [ABSTRACT FROM AUTHOR]

Grid-connected inverters are an important part of the connection between distributed power generation units and the large grid, and their stability is the basis for ensuring the safe operation of distributed power generation units. This study found that there is an inherent digital control delay in the three-phase LCL grid-connected inverter system. This characteristic causes the effective range of capacitive current feedback active damping to be reduced, the selection range of the active damping coefficient to be limited, and the phase at the open-loop cutoff frequency to be reduced. In order to reduce the impact of digital delay, this article conducts a detailed analysis of the characteristics of the first-order lead link that can be used as delay compensation, pointing out that its infinite gain when it obtains the optimal compensation effect will bring noise to the inverter system. This paper proposes a method of cascading digital filters for the first-order leading link to suppress its infinite gain. An improved delay compensation link that is more suitable for numerically controlled inverter systems is constructed. Finally, the effectiveness and necessity of the proposed improved delay compensation link are verified by a simulation platform and an experimental platform. [ABSTRACT FROM AUTHOR]

For medium voltage applications, multilevel inverters are used. One of its classic topologies is the Cascaded H-Bridge, which requires isolated DC voltages to work. Depending on the DC voltage ratio used in the Cascaded H-bridge can be classified into symmetric and asymmetric. In comparison between symmetric and asymmetric inverters, the latter can generate an AC output voltage with more output voltage levels. DC voltage ratio most documented are binary and trinary. The last can generate an AC voltage of 3n = 27 levels is obtained, using n = 3 inverters in cascade and NLM modulation, which generates a flow power of the load to the inverters (regeneration). This work analyzes the semiconductor losses (switching and conduction) and the THD of the AC output voltage in function of index modulation, considering a non-regenerative modulation technique for a 27-level single-phase asymmetric inverter. To confirm the theoretical analyzes, simulation and experimental results are shown. [ABSTRACT FROM AUTHOR]

We present results from an international model comparison study involving a series of controlled fault activation experiments in Opalinus Clay at the Mont Terri Laboratory, Switzerland. The fault activation experiments were conducted in situ by water injection at variable pressure from boreholes targeting different parts of the Main Fault crossing several tunnels and galleries of the Mont Terri Laboratory. The model simulations focused on (1) an experiment activating a discontinuity (fracture or minor fault) within the damage zone of the main fault, and (2) an experiment activating discontinuities close to the core of the Main Fault. The experimental data consist of coupled hydraulic and mechanical responses monitored at an injection borehole and a monitoring borehole located a few meters away. After overcoming several modeling issues along with necessary model developments, a reasonably good agreement was achieved between the modeling results and the field observations. The fault activation experiments displayed an abrupt flow rate increase associated with a sudden fracture opening and rupture propagation after the injection pressure reached above the estimated normal stress on the fracture. This was followed by an abrupt flow rate decrease, indicating hydraulic closing, once the injection pressure decreases to an estimated 1–2 MPa below the stress normal to the opened fracture. The models were able to capture this abrupt hydromechanical behavior, including an observed dominant opening behavior along with the rupture propagation, while the spatial extent of the shear rupture and the quantity of peak injection flow were the most challenging to predict. [ABSTRACT FROM AUTHOR]

Background: Cluster headaches (CH) are recurrent severe headaches, which impose a major burden on the life of patients. We investigated the impact of CH on employment status and job burden.Methods: The study was a sub-study of the Korean Cluster Headache Registry. Patients with CH were enrolled from September 2016 to February 2018 from 15 headache clinics in Korea. We also enrolled a headache control group with age-sex matched patients with migraine or tension-type headache. Moreover, a control group including individuals without headache complaints was recruited. All participants responded to a questionnaire that included questions on employment status, type of occupation, working time, sick leave, reductions in productivity, and satisfaction with current occupation. The questionnaire was administered to participants who were currently employed or had previous occupational experience.Results: We recruited 143 patients with CH, 38 patients with other types of headache (migraine or tension-type headache), and 52 headache-free controls. The proportion of employees was lower in the CH group compared with the headache and headache-free control groups (CH: 67.6% vs. headache controls: 84.2% vs. headache-free controls: 96.2%; p = 0.001). The CH group more frequently experienced difficulties at work and required sick leave than the other groups (CH: 84.8% vs. headache controls: 63.9% vs. headache-free controls: 36.5%; p <  0.001; CH: 39.4% vs. headache controls: 13.9% vs. headache-free controls: 3.4%; p <  0.001). Among the patients with CH, sick leave was associated with younger age at CH onset (25.8 years vs. 30.6 years, p = 0.014), severity of pain rated on a visual analogue scale (9.3 vs. 8.8, p = 0.008), and diurnal periodicity during the daytime (p = 0.003). There were no significant differences with respect to the sick leave based on sex, age, CH subtypes, and CH recurrence.Conclusions: CH might be associated with employment status. Most patients with CH experienced substantial burdens at work. [ABSTRACT FROM AUTHOR]