Dual Function of N-Iodosuccinimide for C(sp3)-B Bond Activation

A practical method for C(sp3)-B bond activation was developed. Using a combination of alkyl trifluoroborates and N-iodosuccinimide (NIS), various C(sp3)-heteroatom bonds were readily generated in an efficient manner. Mechanistic studies revealed the bifunctional ability of NIS: mediating the formation of reactive halogenated intermediates and activating them via halogen bonding. This electrophilic activation of the reaction center enables the utilization of general heteroatom nucleophiles, which are used in a limited capacity in traditional 1,2-metalate rearrangements.

Mechanistic duality of indolyl 1,3-heteroatom transposition

A novel mechanistic duality has been revealed from the indolyl 1,3-heteroatom transposition (IHT) of N-hydroxyindole derivatives. A series of in-depth mechanistic investigations suggests that two separate mechanisms are operating simultaneously. Moreover, the relative contribution of each mechanistic pathway, the energy barrier for each pathway, and the identity of the primary pathway were shown to be the functions of the electronic properties of the substrate system. Based on the mechanistic understanding obtained, a mechanism-driven strategy for the general and efficient introduction of a heteroatom at the 3-position of indole has been developed. The reaction developed exhibits a broad substrate scope to provide the products in various forms of the functionalised indole. Moreover, the method is applicable to the introduction of both oxygen- and nitrogen-based functional groups.

Performance of the World Health Organisation suspected COVID-19 case definition in cluster-associated and sporadic SARS-CoV-2 transmission in Malaysia

INTRODUCTION

Cluster-associated transmission has contributed to the majority of COVID-19 cases in Malaysia. Although widely used, the performance of the World Health Organization (WHO) case definition for suspected COVID19 in environments with high numbers of such cases has not been reported.

MATERIALS AND METHODS

All suspected cases of COVID-19 that self-presented to hospitals or were cluster screened from 1st April to 31st May 2020 were included. Positive SARS-CoV-2 rRT-PCR was used as the diagnostic reference for COVID-19.

RESULTS

540 individuals with suspected COVID-19 were recruited. Two-third of patients were identified through contact screening, while the rest presented sporadically. Overall COVID-19 positivity rate was 59.4% (321/540) which was higher in the cluster screened group (85.6% vs. 11.6%, p<0.001). Overall, cluster-screened COVID-19 cases were significantly younger, had fewer comorbidities and were less likely to be symptomatic than those present sporadically. Mortality was significantly lower in the cluster-screened COVID-19 cases (0.3% vs. 4.5%, p<0.05). A third of all chest radiographs in confirmed COVID-19 cases were abnormal, with consolidation, ground-glass opacities or both predominating in the peripheral lower zones. The WHO suspected case definition for COVID-19 accurately classified 35.4% of all COVID-19 patients, a rate not improved by the addition of baseline radiographic data. Misclassification rate was higher among the cluster-associated cases (80.6%) compared to sporadic cases (35.3%).

CONCLUSION

COVID-19 cases in Malaysia identified by active tracing of community cluster outbreaks had lower mortality rate. The WHO suspected COVID-19 performed poorly in this setting even when chest radiographic information was available, a finding that has implications for future spikes of the disease in countries with similar transmission characteristics.

Stereospecific Acylative Suzuki–Miyaura Cross-Coupling: General Access to Optically Active α-Aryl Carbonyl Compounds

A novel strategy for the stereospecific Pd-catalyzed acylative cross-coupling of enantiomerically enriched alkylboron compounds has been developed. The protocol features an extremely high level of enantiospecificity to allow facile access to synthetically challenging and valuable chiral ketones and carboxylic acid derivatives. The use of a sterically encumbered and electron-rich phosphine ligand proved to be crucial for the success of the reaction. Furthermore, on the basis of experimental and computational studies, a unique mechanism for the transmetalation, assisted by the noncovalent interactions of the C(sp³)-based organoboron reagent, has been identified.

Coat color affects cortisol and serotonin levels in the serum and hairs of Holstein dairy cows exposed to cold winter

Previous studies showed that coat color significantly affects hair cortisol levels but not serum cortisol and serotonin levels in heifers and dairy cows under heat stress conditions. As a follow-up study, we tested whether both serum and hair cortisol and serotonin levels in winter-housed dairy cows were affected by coat color (black vs white). Twenty multiparous high-yielding dairy cows (DIM = 110 ± 25, milk yield = 35 ± 2.1 kg) were assigned to one of the following groups: 1) black coat color (BCC; over 85% of coat black, n = 14) and 2) white coat color (WCC; over 85% of coat white, n = 6). The experimental period lasted 60 d (from December to February), during which the animals were kept in a building with free stalls that had dry river sand bedding. Blood was harvested for 3 consecutive days at the end of the study. Hair was harvested from the forehead of each individual at the beginning and on the end-day of the study. Cortisol and serotonin hormones were measured in serum and hair. Data were analyzed using t-test. The results revealed that cows with BCC had lower hair cortisol and higher hair serotonin levels than those with WCC (P < 0.05). No differences in serum cortisol levels were observed between cows with WCC and BCC (P > 0.05). The serum serotonin level was lower in cows with WCC compared to the BCC group (P < 0.05). Taken together, coat color significantly affected stress levels indicated by higher hair cortisol and lower hair serotonin levels in WCC cows in addition to lower serum serotonin levels in the corresponding animals. This feature of coat color should be considered as a management tool, particularly in countries with long winters.

A Unified Synthetic Strategy to Introduce Heteroatoms via Electrochemical Functionalization of Alkyl Organoboron Reagents

Based on systematic electrochemical analysis, an integrated synthetic platform of C(sp³)-based organoboron compounds was established for the introduction of heteroatoms. The electrochemically mediated bond-forming strategy was shown to be highly effective for the functionalization of sp³-hybridized carbon atoms with significant steric hindrance. Moreover, virtually all the nonmetallic heteroatoms could be utilized as reaction partners using one unified protocol. The observed reactivity stems from the two consecutive single-electron oxidations of the substrate, which eventually generates an extremely reactive carbocation as the key intermediate. The detailed reaction profile could be elucidated through multifaceted electrochemical studies. Ultimately, a new dimension in the activation strategies for organoboron compounds was accomplished through the electrochemically driven reaction development.

A tandem process for the synthesis of β-aminoboronic acids from aziridines with haloamine intermediates

An unprecedented synthetic strategy is devised to generate β-aminoboronic acids from aziridines via a sequential process involving 1,2-iodoamine formation and radical borylation under light irradiation. A variety of aziridines including multiply substituted aziridines have been successfully employed as synthetic precursors, expanding their synthetic utility compared to previous methods. Mechanistic studies suggest that the boron source plays a unique role in the borylation step, and in the formation of haloamine intermediates.

Formation of the Tertiary Sulfonamide C(sp3)-N Bond Using Alkyl Boronic Ester via Intramolecular and Intermolecular Copper-Catalyzed Oxidative Cross-Coupling

A synthetic strategy for the formation of C(sp³)-N bonds, particularly through a copper-catalyzed oxidative cross-coupling, is rare. Herein, we report a novel synthetic approach for the preparation of tertiary sulfonamides via copper-catalyzed intra- and intermolecular oxidative C(sp³)-N cross-coupling reactions. This method allows the utilization of the readily available C(sp³)-based pinacol boronate as a substrate and the tolerance of a wide range of functional groups under mild reaction conditions. The success of this strategy relies on the unprecedented additive effects of silanol and NaIO₄.

Concurrent COVID-19 and dengue with hyperferritinaemia: A case report

The current pandemic of coronavirus disease 2019 (COVID- 19) poses a bigger challenge to the population in tropical countries where dengue fever is also endemic as both diseases share similar clinical and laboratory features. In COVID-19, hyperferritinaemia is associated with severe disease and clinical outcome while in dengue fever, hyperferritinaemia is a key feature of haemophagocytic lymphohistiocytosis (HLH), which is a complication with high mortality. In this case report, we present a case of coinfection of COVID-19 and dengue with hyperferritinaemia in Queen Elizabeth Hospital, Sabah, Malaysia.

Molecular mechanism underlying substrate recognition of the peptide macrocyclase PsnB

Graspetides, also known as ω-ester-containing peptides (OEPs), are a family of ribosomally synthesized and post-translationally modified peptides (RiPPs) bearing side chain-to-side chain macrolactone or macrolactam linkages. Here, we present the molecular details of precursor peptide recognition by the macrocyclase enzyme PsnB in the biosynthesis of plesiocin, a group 2 graspetide. Biochemical analysis revealed that, in contrast to other RiPPs, the core region of the plesiocin precursor peptide noticeably enhanced the enzyme-precursor interaction via the conserved glutamate residues. We obtained four crystal structures of symmetric or asymmetric PsnB dimers, including those with a bound core peptide and a nucleotide, and suggest that the highly conserved Arg213 at the enzyme active site specifically recognizes a ring-forming acidic residue before phosphorylation. Collectively, this study provides insights into the mechanism underlying substrate recognition in graspetide biosynthesis and lays a foundation for engineering new variants.

Concurrent Influenza A and Pulmonary Melioidosis in pregnancy

Melioidosis is endemic in Sabah. It causes significant morbidity and mortality if diagnosis and treatment is delayed. Important risk factors include diabetes, chronic kidney diseases, chronic lung diseases, thalassaemia, immunosuppressive therapy, and hazardous alcohol consumption. Influenza A is usually a self-limiting disease but is associated with high morbidity and mortality in highrisk populations especially during pregnancy. Both melioidosis and influenza A commonly present in patients with pneumonia. Secondary bacterial pneumonia is a known complication in approximately one third of patients with severe pneumonia due to influenza A, resulting in intensive care unit admissions. However, melioidosis is not commonly recognized as an aetiology in secondary bacterial pneumonia complicating influenza A infection. This is important as empirical antibiotics that are used to treat secondary bacterial pneumonia due to influenza A often do not cover melioidosis. Here we report a rare case of concurrent pulmonary melioidosis and influenza A in a 30- year-old primigravida at 27 weeks of pregnancy in the Queen Elizabeth Hospital, Sabah, Malaysia to highlight the challenge in the recognition and management of both infections in a melioidosis endemic area.

Disseminated Melioidosis with Spinal Intraosseous Abscess

Melioidosis is endemic in the State of Sabah, Malaysia. We report a case of a 34-year-old man with one-week history of fever and cough, three days history of diarrhoea and vomiting, which was associated with a loss of appetite and loss of weight for one-month. Clinically, he had hepatosplenomegaly and crepitation over his right lower zone of lung. Chest radiograph showed right lower lobe consolidation. Ultrasound abdomen showed liver and splenic abscesses. Ultrasound guided drainage of splenic abscess yielded Burkholderia pseudomallei. Magnetic resonance imaging (MRI) lumbosacral confirmed right sacral intraosseous abscess after he developed back pain a week later. He received 6 weeks of intravenous antibiotics and oral co-trimoxazole, followed by 6 months oral co-trimoxazole and had full recovery.

Modular Counter-Fischer-Indole Synthesis through Radical-Enolate Coupling

A single-electron transfer mediated modular indole formation reaction from a 2-iodoaniline derivative and a ketone has been developed. This transition-metal-free reaction shows a broad substrate scope and unconventional regioselectivity trends. Moreover, important functional groups for further transformation are tolerated under the reaction conditions. Density functional theory studies reveal that the reaction proceeds by metal coordination, which converts a disfavored 5-endo-trig cyclization to an accessible 7-endo-trig process.

Benzylic C(sp3)-C(sp2) cross-coupling of indoles enabled by oxidative radical generation and nickel catalysis

A mechanistically unique functionalization strategy for a benzylic C(sp3)-H bond has been developed based on the facile oxidation event of indole substrates. This novel pathway was initiated by efficient radical generation at the benzylic position of the substrate, with subsequent transition metal catalysis to complete the overall transformation. Ultimately, an aryl or an acyl group could be effectively delivered from an aryl (pseudo)halide or an acid anhydride coupling partner, respectively. The developed method utilizes mild conditions and exhibits a wide substrate scope for both substituted indoles and C(sp2)-based reaction counterparts. Mechanistic studies have shown that competitive hydrogen atom transfer (HAT) processes, which are frequently encountered in conventional methods, are not involved in the product formation process of the developed strategy.

Restoration of catalytic activity by the preservation of ligand structure: Cu-catalysed asymmetric conjugate addition with 1,1-diborylmethane

Reported herein is a novel reaction engineering protocol to enhance the efficiency of a transition metal-catalysed process by strategically preventing ligand degradation. Based on spectroscopic investigations, a decomposition pathway of a chiral phosphoramidite ligand during a Cu-catalysed reaction was identified. The involvement of the destructive process could be minimized under the modified reaction conditions that control the amount of nucleophilic alkoxide base, which is the origin of ligand decomposition. Overall, the strategy has been successfully applied to a new class of asymmetric conjugate addition reactions with bis[(pinacolato)boryl]methane, in which α,β-unsaturated enones are utilised as substrates.

A novel Cu-catalysed asymmetric conjugate addition reaction with bis[(pinacolato)boryl]methane using α,β-unsaturated enones as substrates has been developed on the basis of strategic preservation of the supporting ligand.

Search for Sub-eV Sterile Neutrinos at RENO

We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino (ν[over ¯]_{e}) disappearance taking place between six 2.8 GW_{th} reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor ν[over ¯]_{e} oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on sin^{2}2θ_{14} in the 10^{-4}≲|Δm_{41}^{2}|≲0.5  eV^{2} region, free from reactor ν[over ¯]_{e} flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at |Δm_{41}^{2}|≲0.002  eV^{2} using the ν[over ¯]_{e} disappearance channel.

A case of co-infection: First reported case of severe plasmodium knowlesi malaria and dengue co-infection in Sabah, Malaysia

We report a rare case of severe Plasmodium knowlesi malaria and dengue co-infection in a 36-year-old lady with hyperparasitaemia, metabolic acidosis, haemolysis and acute kidney injury. She was in shock requiring inotropic support and elective intubation. She had pericardial tamponade which necessitate pericardiocentesis to allow for haemodynamic stability during haemodialysis. She underwent haemodialysis, was ventilated for six days and stayed in hospital for 29 days. She was discharged home well with almost complete renal recovery. Physicians must have a high degree of suspicion for dengue co-infection in malaria patients with plasma leakage such as pericardial effusion to allow for prompt management.

Ciguatera fish poisoning: First reported case in Sabah, Malaysia

Ciguatera fish poisoning (CFP) is the most common natural marine toxin poisoning worldwide and yet under recognised in Malaysia. We report the first confirmed case of CFP in Sabah with severe neurological, cardiovascular and gastrointestinal manifestations after consumption of emperor snapper. Early recognition of CFP is important because it will result in improved patient care and public health intervention.

Fuel-Composition Dependent Reactor Antineutrino Yield at RENO

We report a fuel-dependent reactor electron antineutrino (ν[over ¯]_{e}) yield using six 2.8 GW_{th} reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses 850 666 ν[over ¯]_{e} candidate events with a background fraction of 2.0% acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel ^{235}U dependent variation of measured IBD yields with a slope of (1.51±0.23)×10^{-43}  cm^{2}/fission and measure a total average IBD yield of (5.84±0.13)×10^{-43}  cm^{2}/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6σ. The observed IBD yield variation over ^{235}U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 σ. The measured fuel-dependent variation determines IBD yields of (6.15±0.19)×10^{-43} and (4.18±0.26)×10^{-43}  cm^{2}/fission for two dominant fuel isotopes ^{235}U and ^{239}Pu, respectively. The measured IBD yield per ^{235}U fission shows the largest deficit relative to the HM prediction. Reevaluation of the ^{235}U IBD yield per fission may mostly solve the reactor antineutrino anomaly (RAA) while ^{239}Pu is not completely ruled out as a possible contributor to the anomaly. We also report a 2.9 σ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of ^{235}U.

Measurement of Reactor Antineutrino Oscillation Amplitude and Frequency at RENO

The RENO experiment reports more precisely measured values of θ_{13} and |Δm_{ee}^{2}| using ∼2200 live days of data. The amplitude and frequency of reactor electron antineutrino (ν[over ¯]_{e}) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) ν[over ¯]_{e} candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the measured number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.0896±0.0048(stat)±0.0047(syst) and |Δm_{ee}^{2}|=[2.68±0.12(stat)±0.07(syst)]×10^{-3}  eV^{2}.

Investigation of multifilament MgB2 superconducting joint technique for development of MRI magnets

This study presents the investigation of superconducting joints fabricated using multifilament magnesium diboride (MgB₂) wires for the development of persistent-current mode magnetic resonance imaging (MRI) magnets. The critical current of the jointed samples decreased with increasing cutting angle because the smaller cutting angle allowed greater exposure of the MgB₂ filament, thereby increasing the contact area for the wire-bulk-wire connection. In addition, an appropriate pressing pressure (300 MPa) was necessary to establish the multifilament MgB₂ joint without significant degradation of superconducting properties. The resistance of the optimal MgB₂ joint, measured using the field-decay technique, was <1.5 × 10^-14 Ω. Therefore, the proposed joint technique can be employed for developing multifilament MgB₂ MRI magnets operating in the persistent-current mode.

EphrinB1 promotes cancer cell migration and invasion through the interaction with RhoGDI1

Eph receptors and their corresponding ephrin ligands have been associated with regulating cell–cell adhesion and motility, and thus have a critical role in various biological processes including tissue morphogenesis and homeostasis, as well as pathogenesis of several diseases. Aberrant regulation of Eph/ephrin signaling pathways is implicated in tumor progression of various human cancers. Here, we show that a Rho family GTPase regulator, Rho guanine nucleotide dissociation inhibitor 1 (RhoGDI1), can interact with ephrinB1, and this interaction is enhanced upon binding the extracellular domain of the cognate EphB2 receptor. Deletion mutagenesis revealed that amino acids 327–334 of the ephrinB1 intracellular domain are critical for the interaction with RhoGDI1. Stimulation with an EphB2 extracellular domain-Fc fusion protein (EphB2-Fc) induces RhoA activation and enhances the motility as well as invasiveness of wild-type ephrinB1-expressing cells. These Eph-Fc-induced effects were markedly diminished in cells expressing the mutant ephrinB1 construct (Δ327–334) that is ineffective at interacting with RhoGDI1. Furthermore, ephrinB1 depletion by siRNA suppresses EphB2-Fc-induced RhoA activation, and reduces motility and invasiveness of the SW480 and Hs578T human cancer cell lines. Our study connects the interaction between RhoGDI1 and ephrinB1 to the promotion of cancer cell behavior associated with tumor progression. This interaction may represent a therapeutic target in cancers that express ephrinB1.

VUV spectroscopy in impurity injection experiments at KSTAR using prototype ITER VUV spectrometer

The ITER vacuum ultra-violet (VUV) core survey spectrometer has been designed as a 5-channel spectral system so that the high spectral resolving power of 200-500 could be achieved in the wavelength range of 2.4-160 nm. To verify the design of the ITER VUV core survey spectrometer, a two-channel prototype spectrometer was developed. As a subsequent step of the prototype test, the prototype VUV spectrometer has been operated at KSTAR since the 2012 experimental campaign. From impurity injection experiments in the years 2015 and 2016, strong emission lines, such as Kr xxv 15.8 nm, Kr xxvi 17.9 nm, Ne vii 46.5 nm, Ne vi 40.2 nm, and an array of largely unresolved tungsten lines (14-32 nm) could be measured successfully, showing the typical photon number of 10¹³-10¹⁵ photons/cm² s.

Note: Progress on the use of MgB2 superconducting joint technique for the development of MgB2 magnets for magnetic resonance imaging (MRI)

This note presents a superconducting joint technique for the development of MgB₂ magnetic resonance imaging (MRI) magnets. The MgB₂ superconducting joint was fabricated by a powder processing method using Mg and B powders to establish a wire-bulk-wire connection. The joint resistance measured using a field-decay method was <10^-14 Ω, demonstrating that the proposed joint technique could be employed for developing "next-generation" MgB₂ MRI magnets operating in the persistent current mode.

Direct 11CN-Labeling of Unprotected Peptides via Palladium-Mediated Sequential Cross-Coupling Reactions

A practical procedure for ¹¹CN-labeling of unprotected peptides has been developed. The method was shown to be highly chemoselective for cysteine over other potentially nucleophilic residues, and the radiolabeled products were synthesized and purified in less than 15 min. Appropriate for biomedical applications, the method could be used on an extremely small scale (20 nmol) with a high radiochemical yield. The success of the protocol stems from the use of a Pd-reagent based on a dihaloarene, which enables direct "nucleophile-nucleophile" coupling of the peptide and [¹¹C]cyanide by temporal separation of nucleophile addition.

Palladium-Mediated Arylation of Lysine in Unprotected Peptides

A mild method for the arylation of lysine in an unprotected peptide is presented. In the presence of a preformed biarylphosphine-supported palladium(II)-aryl complex and a weak base, lysine amino groups underwent C-N bond formation at room temperature. The process generally exhibited high selectivity for lysine over other amino acids containing nucleophilic side chains and was applicable to the conjugation of a variety of organic compounds, including complex drug molecules, with an array of peptides. Finally, this method was also successfully applied to the formation of cyclic peptides by macrocyclization.

Mandibular stability using sliding or conventional four-hole plates for fixation after bilateral sagittal split ramus osteotomy for mandibular setback

Our aim was to compare the postoperative stability of the mandible when two different fixation methods had been used after bilateral sagittal split ramus osteotomy (BSSRO) for mandibular setback. The study included 23 patients who had two-jaw BSSRO mandibular setback at the Department of Oromaxillofacial Surgery, Korea University Guro Hospital, between January 2011 and June 2014. The first group (four-hole (control) group, n=13) comprised patients whose bony segments were fixed with conventional four-hole plates, and the second (sliding plate (experimental) group, n=10) included patients whose bone segments were fixed with sliding plates. Lateral cephalograms were taken and analysed at three time points: preoperatively (T1), and one week (T2), and 1year (T3) postoperatively. The Mann-Whitney U test was used to compare the postoperative stability of the mandible in each group. There were no significant differences between the two groups in changes in the horizontal and vertical positions of point B and pogonion postoperatively, nor were there any significant differences between them in ramal inclination and inclination of the SN plane with point B at the given time points (p=>0.05 in surgical changes in the mandible immediately after surgery and 0.397, 0.616, 0.082, 0.951, 0.901, 0.476 in postoperative changes in the mandible 1 week to 1 year after surgery). Like the conventional four-hole plate, the sliding plate can also be used to achieve stability in the fixation of mandibular bone segments after BSSRO.

Investigation on quench initiation and propagation characteristics of GdBCO coil co-wound with a stainless steel tape as turn-to-turn metallic insulation

This paper investigates the quench initiation and propagation characteristics of a metallic insulation (MI) coil by conducting thermal quench tests for a GdBCO single-pancake coil co-wound with a stainless steel tape as the turn-to-turn MI. The test results confirmed that the MI coil exhibited superior thermal and electrical stabilities compared to the conventional coils co-wound with organic insulation material because the operating current could flow along the radial direction due to the existence of a turn-to-turn contact when a local hot spot was generated. The results of the quench test at a heater current (I_h) of 12, 13, and 14 A indicate that the MI coil possesses a self-protecting characteristic resulting from the "current bypass" through the turn-to-turn contact. However, the test coil was not self-protecting at I_h = 15 A because the Joule heat energy generated by the radial current flow was not completely dissipated due to the characteristic resistance of the metallic insulation tape and the non-superconducting materials, including the substrate, stabilizer, and buffer layers within the high-temperature superconductor (HTS) tape. Even though the MI coil possesses superior thermal and electrical stability relative to those of conventional HTS coils co-wound with an organic material as turn-to-turn insulation, it is essential to consider the critical role of the Joule heat energy resulting from the operating current and stored magnetic energy as well as the characteristic resistances in order to further develop self-protective 2G HTS magnets.

A novel no-insulation winding technique of high temperature-superconducting racetrack coil for rotating applications: A progress report in Korea university

This paper presents our recent progress on core technology development for a megawatt-class superconducting wind turbine generator supported by the international collaborative R&D program of the Korea Institute of Energy Technology Evaluation and Planning. To outperform the current high-temperature-superconducting (HTS) magnet technology in the wind turbine industry, a novel no-insulation winding technique was first proposed to develop the second-generation HTS racetrack coil for rotating applications. Here, we briefly report our recent studies on no-insulation (NI) winding technique for GdBCO coated conductor racetrack coils in the following areas: (1) Charging-discharging characteristics of no-insulation GdBCO racetrack coils with respect to external pressures applied to straight sections; (2) thermal and electrical stabilities of no-insulation GdBCO racetrack coils encapsulated with various impregnating materials; (3) quench behaviors of no-insulation racetrack coils wound with GdBCO conductor possessing various lamination layers; (4) electromagnetic characteristics of no-insulation GdBCO racetrack coils under time-varying field conditions. Test results confirmed that this novel NI winding technique was highly promising. It could provide development of a compact, mechanically dense, and self-protecting GdBCO magnet for use in real-world superconducting wind turbine generators.

Effects of dietary mixture of garlic (Allium sativum), coriander (Coriandrum sativum) and probiotics on immune responses and caecal counts in young laying hens

This study was conducted to evaluate the effects of a combined mixture of phytogenic extracts (garlic and coriander) and probiotics on growth performance and immune responses in laying hens based on the results of in vitro studies to screen for immunomodulatory potency of each ingredient. Several parameters of immunomodulatory potency were estimated using lamina propria leucocytes (LPLs) isolated from rat intestinal mucosa tissue. Results show that the combined mixture enhanced LPLs proliferation, increased LPL-mediated cytotoxicity against YAC-1 tumour cells, and decreased lipopolysaccharide (LPS)-induced cytokine production including tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in LPLs. For in vivo study, laying hens (n = 50/each diet group) were fed with control diet, a diet containing antibiotics (0.01% per kg feed) or the combined mixture (0.02% per kg feed) for 21 days. The dietary combined mixture improved egg production (p < 0.05) but not growth performance and carcass traits. Interestingly, the patterns of suppressing plasma IFN-γ productions during inflammation by LPS injection and decreasing caecal E. coli counts in the combined mixture group were comparable to those in the antibiotics group. Taken together, our results suggested that the 0.02% of combined mixture of phytogenic extracts and probiotics as ingredients has potential immunomodulatory effects in laying hens.

Nitrogen Arylation for Macrocyclization of Unprotected Peptides

We describe an efficient and mild method for the synthesis of macrocyclic peptides via nitrogen arylation from unprotected precursors. Various electrophiles and lysine-based nucleophiles were investigated and showed high-yielding product formation, even for a macrocyclization scan with 14 variants. We found that nitrogen-linked aryl products were more stable to base and oxidation when compared to thiol arylated species, thereby highlighting the utility of this methodology. Finally, N-aryl macrocyclization was performed on a p53 peptide inhibitor of MDM2 and resulted in identification of a nanomolar binder with improved proteolytic stability and cell permeability.

Analytical and experimental investigation of electrical characteristics of a metallic insulation GdBCO coil

This paper presents results, experimental and analytical, of the electrical characteristics of GdBCO single-pancake coils co-wound with a brass tape as metallic insulation (MI coil). The GdBCO pancakes were subjected to sudden discharge, charge-discharge, and over-current tests. The sudden discharge and charge-discharge test results of the MI coil demonstrated that MI coils can be charged and discharged significantly faster than non-insulated coils that are wound only with GdBCO tape. In over-current tests at 150 A (1.25I(c)), the MI coil exhibited better electrical behavior, i.e., self-protecting features, than its counterpart co-wound with Kapton tape, an insulator. Moreover, the experimental and analytical results are in agreement, validating the use of a concise equivalent parallel-RL circuit model for the MI coil to characterize its electrical behavior. Overall, the MI winding technique is highly promising to help build compact, mechanically robust, and self-protecting magnets composed of REBCO pancake coils. With no organic material in the winding, MI REBCO pancakes will be immune to neutron radiation damage, making the MI winding technique a viable option for fusion reactors, such as for toroidal field, poroidal field magnets, and central solenoid.

Body Temperature Monitoring Using Subcutaneously Implanted Thermo-loggers from Holstein Steers

Body temperature (BT) monitoring in cattle could be used to early detect fever from infectious disease or physiological events. Various ways to measure BT have been applied at different locations on cattle including rectum, reticulum, milk, subcutis and ear canal. In other to evaluate the temperature stability and reliability of subcutaneous temperature (ST) in highly fluctuating field conditions for continuous BT monitoring, long term ST profiles were collected and analyzed from cattle in autumn/winter and summer season by surgically implanted thermo-logger devices. Purposes of this study were to assess ST in the field condition as a reference BT and to determine any location effect of implantation on ST profile. In results, ST profile in cattle showed a clear circadian rhythm with daily lowest at 05:00 to 07:00 AM and highest around midnight and rather stable temperature readings (mean±standard deviation [SD], 37.1°C to 37.36°C±0.91°C to 1.02°C). STs are 1.39°C to 1.65°C lower than the rectal temperature and sometimes showed an irregular temperature drop below the normal physiologic one: 19.4% or 36.4% of 54,192 readings were below 36.5°C or 37°C, respectively. Thus, for BT monitoring purposes in a fever-alarming-system, a correction algorithm is necessary to remove the influences of ambient temperature and animal resting behavior especially in winter time. One way to do this is simply discard outlier readings below 36.5°C or 37°C resulting in a much improved mean±SD of 37.6°C±0.64°C or 37.8°C±0.55°C, respectively. For location the upper scapula region seems the most reliable and convenient site for implantation of a thermo-sensor tag in terms of relatively low influence by ambient temperature and easy insertion compared to lower scapula or lateral neck.

A Fluorinated Ligand Enables Room-Temperature and Regioselective Pd-Catalyzed Fluorination of Aryl Triflates and Bromides

A new biaryl monophosphine ligand (AlPhos, L1) allows for the room-temperature Pd-catalyzed fluorination of a variety of activated (hetero)aryl triflates. Furthermore, aryl triflates and bromides that are prone to give mixtures of regioisomeric aryl fluorides with Pd-catalysis can now be converted to the desired aryl fluorides with high regioselectivity. Analysis of the solid-state structures of several Pd(II) complexes, as well as density functional theory (DFT) calculations, shed light on the origin of the enhanced reactivity observed with L1.

Effects of Supplementing Brown Seaweed By-products in the Diet of Holstein Cows during Transition on Ruminal Fermentation, Growth Performance and Endocrine Responses

This study was conducted to examine the effects of supplementing brown seaweed by-products (BSB) in the diet of ruminants on ruminal fermentation characteristics, growth performance, endocrine response, and milk production in Holstein cows. In Experiment 1, the effects of different levels (0%, 2%, and 4% of basal diet as Control, 2% BSB, 4% BSB, respectively) of BSB were evaluated at 3, 6, 9, 12, and 24 h in vitro batch culture rumen fermentation. The pH tended to be higher for the higher level of BSB supplementation, with the pH at 12 h being significantly higher (p<0.05) than that of the control. The concentration of ammonia nitrogen was lower at 3, 9, 12, and 24 h incubation (p<0.05) compared with the control, and tended to be low at other incubation times. Volatile fatty acid concentration appeared to be minimally changed while lower values were observed with 4% BSB treatment at 24 h (p<0.05). In Experiment 2, effects of levels (0%, 2%, and 4%) of BSB on growth performance, endocrine responses and milk production were studied with Holstein dairy cows during transition. Dry matter intake, daily gain and feed efficiency were not affected by BSB supplementation. The concentration of plasma estrogen for the control, 2% BSB and 4% BSB after three months of pregnancy were 55.7, 94.1, and 72.3 pg/mL, respectively (p = 0.08). Although the differences of progesterone levels between BSB treatments and the control were minimal, the concentration in 4% BSB treatment increased to 157.7% compared with the initial level of the study. Triiodothyronine and thyroxine levels were also higher after both three months and eight months of pregnancy than the initial level at the beginning of the study. In addition, BSB treatments during one month after delivery did not affect daily milk yield and composition. In conclusion, the present results indicate that supplementation of BSB did not compromise ruminal fermentation, and animal performance at lower levels and hence may have potential to be used as a safe feed ingredient in dairy cows.

Brain mechanisms of pain relief by transcutaneous electrical nerve stimulation: A functional magnetic resonance imaging study

BACKGROUND

Although the exact mechanism of TENS pain relief is unknown, it is believed that TENS impulses interrupt nociceptive signals at the dorsal horn of the spinal cord.

AIMS

To evaluate the hypotheses that during pain caused by noxious stimuli, brain responses, temporal summation and brain functional connectivity are modulated by TENS, and that mechanisms of pain relief by TENS differ between men and women.

METHODS

During fMRI scanning, the same noxious stimuli were delivered to each participant in pain-only and pain+TENS conditions. In the pain-only condition, noxious stimuli were presented without TENS. In the pain+TENS condition, participants received noxious stimuli and TENS concurrently. Participants were initially presented with TENS at an intensity that was just below that causing discomfort. TENS intensity was presented in a step-wise fashion to prevent temporal summation from repetitive noxious stimuli.

RESULTS

Pain and unpleasantness ratings were significantly higher in the pain-only than the pain+TENS condition. With non-painful TENS, primary and secondary somatosensory and parietal cortices were activated, and temporal summation from repetitive noxious stimuli was prevented. Periaqueductal gray (PAG) and lateral prefrontal cortex functional connectivity was increased by TENS, and modulated by testosterone and cortisol. Women reported greater pain during TENS than men, and showed greater activation in the temporoparietal junction cortex and increased PAG functional connectivity with the orbitofrontal cortex.

CONCLUSION

TENS led to pain reduction, probably due to activation of the descending pain-inhibitory pathway, indicating that this TENS method may be applied in clinical practice.

Virtually instantaneous, room-temperature [(11)C]-cyanation using biaryl phosphine Pd(0) complexes

A new radiosynthetic protocol for the preparation of [(11)C]aryl nitriles has been developed. This process is based on the direct reaction of in situ prepared L·Pd(Ar)X complexes (L = biaryl phosphine) with [(11)C]HCN. The strategy is operationally simple, exhibits a remarkably wide substrate scope with short reaction times, and demonstrates superior reactivity compared to previously reported systems. With this procedure, a variety of [(11)C]nitrile-containing pharmaceuticals were prepared with high radiochemical efficiency.

4-methylphenol produced in freshwater sediment microcosms is not a bisphenol A metabolite

4-Methylphenol (4-MP), a putative bisphenol A (BPA) degradation intermediate, was detected at concentrations reaching 2.1 mg L(-1) in anoxic microcosms containing 10 mg L(-1) BPA and 5 g of freshwater sediment material collected from four geographically distinct locations and amended with nitrate, nitrite, ferric iron, or bicarbonate as electron acceptors. 4-MP accumulation was transient, and 4-MP degradation was observed under all redox conditions tested. 4-MP was not detected in microcosms not amended with BPA. Unexpectedly, incubations with (13)C-labeled BPA failed to produce (13)C-labeled 4-MP suggesting that 4-MP was not derived from BPA. The detection of 4-MP in live microcosms amended with lactate, but not containing BPA corroborated that BPA was not the source of 4-MP. These findings demonstrate that the transient formation of 4-MP as a possible BPA degradation intermediate must be interpreted cautiously, as microbial activity in streambed microcosms may generate 4-MP from sediment-associated organic material.

Test of prototype ITER vacuum ultraviolet spectrometer and its application to impurity study in KSTAR plasmas

To optimize the design of ITER vacuum ultraviolet (VUV) spectrometer, a prototype VUV spectrometer was developed. The sensitivity calibration curve of the spectrometer was calculated from the mirror reflectivity, the grating efficiency, and the detector efficiency. The calibration curve was consistent with the calibration points derived in the experiment using the calibrated hollow cathode lamp. For the application of the prototype ITER VUV spectrometer, the prototype spectrometer was installed at KSTAR, and various impurity emission lines could be measured. By analyzing about 100 shots, strong positive correlation between the O VI and the C IV emission intensities could be found.

Structure and Reactivity of [(L•Pd)n•(1,5-cyclooctadiene)] (n=1-2) Complexes Bearing Biaryl Phosphine Ligands

The structure of the stable Pd(0) precatalyst [(1,5-cyclooctadiene)(L•Pd)2] (L = AdBrettPhos) for the Pd-catalyzed fluorination of aryl triflates has been further studied by solid state NMR and X-ray cystrallography of the analogous N-phenylmaleimide complex. The reactivity of this complex with CDCl3 to form a dearomatized complex is also presented. In addition, studies suggest that related bulky biaryl phosphine ligands form similar complexes, although the smaller ligand BrettPhos forms a monomeric [(1,5-cyclooctadiene)(L•Pd)] species instead.

Investigation of thermal and electrical stabilities of a GdBCO coil using grease as an insulation material for practical superconducting applications

This paper presents the effects of thermal grease on the electrical and thermal characteristics of GdBCO pancake coils, observed through charge-discharge, sudden discharge, over-current, and thermal quench testing. In charge-discharge and sudden discharge tests, a coil using thermal grease as an insulation material demonstrated faster charging/discharging rates compared to a coil without turn-to-turn insulation. In the case of over-current tests, the coil using thermal grease exhibited the highest electrical stability. Furthermore, thermal quench testing showed the coil employing thermal grease to possess superior thermal characteristics, with rapid cooling and low temperature rise. Overall, the use of thermal grease as an insulation material may be a potential solution to the problems observed with the existing insulation materials, possessing fast charging/discharging rates with superior thermal and electrical stabilities.

A numerical study on the charge transport in TPD/Alq3-based organic light emitting diodes

We report our simulation study on the charge transport characteristic of the multi-layer structure for organic light emitting diodes (OLEDs). We performed a numerical simulation on a multilayer structure comprising a hole transport layer (HTL), an emission layer (EML), and an electron transport layer (ETL) between both electrodes. The material of the HTL is TPD (N,N'-Bis (3-methylphenyl)-N,N'-bis(phenyl) benzidine), and the ETL includes Alq3 (Tris (8-hyroxyquinolinato) aluminium). Here, we investigated the parameters such as recombination rates which influence the efficiency of the charge transport between layers in bilayer OLEDs. We also analyzed a transient response during the turn on/off period and the carrier transport in accordance with the variation of the injection barrier and applied voltage. In addition, our numerical simulation revealed that the insertion of the EML affects the photonic characteristics in bilayer structure and also the efficiency due to the difference in the internal barrier height.

Proteome Analysis of Bovine Longissimus dorsi Muscle Associated with the Marbling Score

The breeding value of marbling score in skeletal muscle is an important factor for evaluating beef quality. In the present study, we investigated proteins associated with the breeding value of the marbling score for bovine sirloin to select potential biomarkers to improve meat quality through comparative proteomic analysis. Proteins isolated from muscle were separated by two-dimensional gel electrophoresis. After analyzing images of the stained gel, seven protein spots for the high marbling score group were identified corresponding to changes in expression that were at least two-fold compared to the low marbling score group. Four spots with increased intensities in the high marbling score group were identified as phosphoglycerate kinase 1, triosephophate isomerase, acidic ribosomal phosphoprotein PO, and capping protein (actin filament) Z-line alpha 2. Spots with decreased intensities in the high marbling score group compared to the low score group were identified as 14-3-3 epsilon, carbonic anhydrase II, and myosin light chain 1. Expression of myosin light chain 1 and carbonic anhydrase 2 was confirmed by Western blotting. Taken together, these data could help improve the economic performance of cattle and provide useful information about the underlying the function of bovine skeletal muscle.

Effect of Oral Administration of Intact Casein on Gastrointestinal Hormone Secretion and Pancreatic α-Amylase Activity in Korean Native Steer

Three Korean native steers (779±24 kg) fitted with duodenal cannulas were used in a 3×3 Latin square design to investigate the influence of oral administration of soluble proteins, intact casein (IC) and acid hydrolyzed casein (AHC), on gastrointestinal hormone (GIH) secretion in the blood and pancreatic α-amylase activity in the duodenum. Oral treatment consisted of a basic diet (control), IC (C+100% protein), or AHC (C+80% amino acid, 20% peptide) for 21 d. Blood and duodenum samples were collected for measurement of serum GI hormones, and pancreatic α-amylase activity was determined at 900, 1030, 1330, 1630, and 1930 h after feeding on d 21 of treatment. The levels of serum cholecystokinin (CCK) and secretin in the IC treatment group were higher compared to the other treatment groups (p<0.05). In addition to the changes in CCK and secretin levels upon IC treatment, the pancreatic α-amylase activity in the duodenum was higher in the IC group compared to the control diet group (p<0.05). The response of serum ghrelin to IC and AHC treatment was in accordance with the response of serum secretin. The level of peptide fragments flowing in the duodenum was higher in the IC treatment group than the other treatment groups (p<0.05). In conclusion, this study demonstrated that an increase in duodenal CCK and secretin upon IC oral administration increased pancreatic α-amylase secretion. In addition, ghrelin may be associated with GI hormone secretion in Korean native steers.

Pd-catalyzed nucleophilic fluorination of aryl bromides

On the basis of mechanism-driven reaction design, a Pd-catalyzed nucleophilic fluorination of aryl bromides and iodides has been developed. The method exhibits a broad substrate scope, especially with respect to nitrogen-containing heteroaryl bromides, and proceeds with minimal formation of the corresponding reduction products. A facilitated ligand modification process was shown to be critical to the success of the reaction.

Cystatin SN neutralizes the inhibitory effect of cystatin C on cathepsin B activity

Cystatin SN (CST1) is one of the several salivary cystatins that form tight equimolar complexes with cysteine proteases, such as the cathepsins. High expression of CST1 is correlated with advanced pTNM stage in gastric cancer. However, the functional role of CST1 in tumorigenesis has not been elucidated. In this study, we showed that CST1 was highly expressed in colon tumor tissues, compared with nontumor regions. Increased cell proliferation and invasiveness were observed in HCT116 cell lines stably transfected with CST1 cDNA (HCT116-CST1) but not in CST3-transfected cells. We also demonstrated that CST1-overexpressing cell lines exhibited increased tumor growth as well as metastasis in a xenograft nude mouse model. Interestingly, CST1 interacted with cystatin C (CST3), a potent cathepsin B (CTSB) inhibitor, with a higher affinity than the interaction between CST3 and CTSB in the extracellular space of HCT116 cells. CTSB-mediated cellular invasiveness and proteolytic activities were strongly inhibited by CST3, but in the presence of CST1 CTSB activities recovered significantly. Furthermore, domain mapping of CST1 showed that the disulfide-bonded conformation, or conserved folding, of CST1 is important for its secretion and for the neutralization of CST3 activity. These results suggest that CST1 upregulation might be involved in colorectal tumorigenesis and acts by neutralizing the inhibition of CTSB proteolytic activity by CST3.