Observation of the Anomalous Hall Effect in a Layered Polar Semiconductor.

Progress in magnetoelectric materials is hindered by apparently contradictory requirements for time-reversal symmetry broken and polar ferroelectric electronic structure in common ferromagnets and antiferromagnets. Alternative routes can be provided by recent discoveries of a time-reversal symmetry breaking anomalous Hall effect (AHE) in noncollinear magnets and altermagnets, but hitherto reported bulk materials are not polar. Here, the authors report the observation of a spontaneous AHE in doped AgCrSe2 , a layered polar semiconductor with an antiferromagnetic coupling between Cr spins in adjacent layers. The anomalous Hall resistivity 3 µ Ω c m $\mu \Omega \, \textnormal {cm}$ is comparable to the largest observed in compensated magnetic systems to date, and is rapidly switched off when the angle of an applied magnetic field is rotated to ≈80° from the crystalline c-axis. The ionic gating experiments show that the anomalous Hall conductivity magnitude can be enhanced by modulating the p-type carrier density. They also present theoretical results that suggest the AHE is driven by Berry curvature due to noncollinear antiferromagnetic correlations among Cr spins, which are consistent with the previously suggested magnetic ordering in AgCrSe2 . The results open the possibility to study the interplay of magnetic and ferroelectric-like responses in this fascinating class of materials.

Investigation of Planckian behavior in a high-conductivity oxide: PdCrO2.

The layered delafossite metal PdCrO[Formula: see text] is a natural heterostructure of highly conductive Pd layers Kondo coupled to localized spins in the adjacent Mott insulating CrO[Formula: see text] layers. At high temperatures, T, it has a T-linear resistivity which is not seen in the isostructural but nonmagnetic PdCoO[Formula: see text]. The strength of the Kondo coupling is known, as-grown crystals are extremely high purity and the Fermi surface is both very simple and experimentally known. It is therefore an ideal material platform in which to investigate "Planckian metal" physics. We do this by means of controlled introduction of point disorder, measurement of the thermal conductivity and Lorenz ratio, and studying the sources of its high-temperature entropy. The T-linear resistivity is seen to be due mainly to elastic scattering and to arise from a sum of several scattering mechanisms. Remarkably, this sum leads to a scattering rate within 10[Formula: see text] of the Planckian value of k[Formula: see text]T/[Formula: see text].

Does COVID-19 Infection within 1 Week after Total Knee Arthroplasty Affect Patients' Early Clinical Outcomes? A Matched Case-Control Study.

Recent studies have reported the impact of previous COVID-19 infection on the early clinical outcome after total knee arthroplasty (TKA). However, the timing of infection before the surgery was not constant and a study on patients with COVID-19 infection within 1 week after TKA is lacking. This study aimed to determine the effect of COVID-19 infection within one week after TKA on the postoperative outcomes and to compare the early clinical outcomes to those who were not infected with COVID-19 before and after surgery. No significant differences were observed between the two groups in terms of clinical outcomes or complications. The length of the hospital stay (LOS) was significantly longer for the COVID-19 group than for the non-COVID-19 group (p < 0.05). The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were higher for the study group on postoperative days 9 and 12 than for those in the control group (p < 0.05). However, D-dimer levels were not significantly different between the two groups. We should cautiously consider that COVID-19 infection within 1 week after TKA may be associated with increased ESR, CRP levels, and length of hospital stay, but they are not associated with the worsening of early clinical outcomes or the occurrence of complications.

Shelf Life Prediction of Vacuum-Packaged Grilled Mackerel.

The current study aimed to establish the shelf life of vacuum-packaged grilled mackerel stored at 5, -5, and -20°C for 70 days. To this end, physicochemical analyses, which involved determining the pH, volatile basic nitrogen, amino nitrogen, trimethylamine (TMA), and thiobarbituric acid levels; microbiological analyses (aerobic plate count and coliform); and sensory quality determination were performed. Regression analysis on the relationship between physicochemical properties and storage time at various temperatures revealed TMA level was the most suitable parameter (R2=0.9769) for predicting changes in the quality of grilled mackerel during storage, with a quality limit value of 8.74 mg/100 g. The shelf life of vacuum-packaged grilled mackerel according to temperature was 21, 53, 62, and 75 days for 5, -5, -15, and -20°C, respectively, with the use-by date being 23 days at 5°C and 74 days at -5°C. In conclusion, TMA was the most suitable parameter for predicting changes in the quality of grilled mackerel during storage.

Intersection of multiple factors shape Korean American caregiver experience in dementia caregiving.

BACKGROUND AND OBJECTIVES: Studies have shown that cultural norms such as filial responsibility and familism operate in the Korean American caregiving context. The purpose of our study is to understand the practice of Korean American caregivers who provide care to a family member living with dementia and their dementia care support needs. MATERIALS AND METHODS: We conducted 2 focus groups and individual semi-structured interviews with a total of 20 Korean American caregivers. We used inductive thematic analysis to guide coding and generation of themes. RESULTS: Three themes were identified; 1) intersectionality in the Korean American caregiver experience, 2) complex family dynamics, and 3) dementia care barriers and caregiver support needs. Within the dyadic relationship and the family, cultural identity, generational, acculturational, and language factors shaped the caregiver experience. The need to navigate bicultural norms could lead to tensions but also provide opportunity for caregivers to consider self-care and use external supports to decrease the work of caregiving. Family was the unit of caregiving and caregiving was divided among family members based on acculturation and language fluency. Caregivers desired both medical information combined with knowledge that experienced lay support could provide. Support that reflects their cultural context was valued. DISCUSSION: Findings suggest the importance of understanding the diversity of response to strong elder care norms among Korean American caregivers and the intersection of multiple factors that influence their caregiving experience. Integrating acculturation and generational assessments may be useful as a way to tailor interventions to optimize engagement in dementia care interventions.

Organic Thermoelectric Nanocomposites Assembled via Spraying Layer-by-Layer Method.

Thermoelectric (TE) materials have been considered as a promising energy harvesting technology for sustainably providing power to electronic devices. In particular, organic-based TE materials that consist of conducting polymers and carbon nanofillers make a large variety of applications. In this work, we develop organic TE nanocomposites via successive spraying of intrinsically conductive polymers such as polyaniline (PANi) and poly(3,4-ethylenedioxy- thiophene):poly(styrenesulfonate) (PEDOT:PSS) and carbon nanofillers, and single-walled carbon nanotubes (SWNT). It is found that the growth rate of the layer-by-layer (LbL) thin films, which comprise a PANi/SWNT-PEDOT:PSS repeating sequence, made by the spraying method is greater than that of the same ones assembled by traditional dip coating. The surface structure of multilayer thin films constructed by the spraying approach show excellent coverage of highly networked individual and bundled SWNT, which is similarly to what is observed when carbon nanotubes-based LbL assemblies are formed by classic dipping. The multilayer thin films via the spray-assisted LbL process exhibit significantly improved TE performances. A 20-bilayer PANi/SWNT-PEDOT:PSS thin film (~90 nm thick) yields an electrical conductivity of 14.3 S/cm and Seebeck coefficient of 76 µV/K. These two values translate to a power factor of 8.2 µW/m·K2, which is 9 times as large as the same films fabricated by a classic immersion process. We believe that this LbL spraying method will open up many opportunities in developing multifunctional thin films for large-scaled industrial use due to rapid processing and the ease with which it is applied.

GNI Corpus Version 1.0: Annotated Full-Text Corpus of Genomics & Informatics to Support Biomedical Information Extraction.

Genomics & Informatics (NLM title abbreviation: Genomics Inform) is the official journal of the Korea Genome Organization. Text corpus for this journal annotated with various levels of linguistic information would be a valuable resource as the process of information extraction requires syntactic, semantic, and higher levels of natural language processing. In this study, we publish our new corpus called GNI Corpus version 1.0, extracted and annotated from full texts of Genomics & Informatics, with NLTK (Natural Language ToolKit)-based text mining script. The preliminary version of the corpus could be used as a training and testing set of a system that serves a variety of functions for future biomedical text mining.

Spatial Disparity in Food Environment and Household Economic Resources Related to Food Insecurity in Rural Korean Households with Older Adults.

Different contextual factors of a household and a community, such as access to resources and transportation, may influence the level of food insecurity. The objective of this study was to identify how food environmental factors and economic resources were related to food insecurity in Korean older adults residing in different contexts of rural areas. Face-to-face interviews with 248 older adults residing in land (n = 149) and mountain (n = 99) rural areas were performed. In both areas, risk of food insecurity was increased for households with limited community food accessibility measured by having difficulties in food purchasing due to food stores far from home. There were discrepancies in factors related to increased risks of food insecurity between households in land and mountain areas. The experience of reducing food expenditure resulting from burden of heating costs during the winter in households in a mountain area whereas the percent proportion of housing fee and household cook's physical disability in households residing in the land area were found to be factors associated with increased risks of food insecurity. For households residing in mountain areas, the risk of food insecurity was decreased when economic resources measured by average monthly income for the last one year was increased and there was farming or home gardening activity. Such spatial disparity might affect household food insecurity in rural areas. In addition, food environmental factors and economic resources may affect household food insecurity differently according to the diverse contexts of rural areas. Better understanding of spatial challenges in food insecurity faced by seniors in a large rural area would help prepare programs or policy change to strengthen and improve their food environments.

Does Polymerase Chain Reaction of Tissue Specimens Aid in the Diagnosis of Tuberculosis?

BACKGROUND: Mycobacterial culture is the gold standard test for diagnosing tuberculosis (TB), but it is time-consuming. Polymerase chain reaction (PCR) is a highly sensitive and specific method that can reduce the time required for diagnosis. The diagnostic efficacy of PCR differs, so this study determined the actual sensitivity of TB-PCR in tissue specimens. METHODS: We retrospectively reviewed 574 cases. The results of the nested PCR of the IS6110 gene, mycobacterial culture, TB-specific antigen-induced interferon-γ release assay (IGRA), acid-fast bacilli (AFB) staining, and histological findings were evaluated. RESULTS: The positivity rates were 17.6% for PCR, 3.3% for the AFB stain, 22.2% for mycobacterial culture, and 55.4% for IGRA. PCR had a low sensitivity (51.1%) and a high specificity (86.3%) based on the culture results of other studies. The sensitivity was higher (65.5%) in cases with necrotizing granuloma but showed the highest sensitivity (66.7%) in those with necrosis only. The concordance rate between the methods indicated that PCR was the best method compared to mycobacterial culture, and the concordance rate increased for the methods using positive result for PCR or histologic features. CONCLUSIONS: PCR of tissue specimens is a good alternative to detect tuberculosis, but it may not be as sensitive as previously suggested. Its reliability may also be influenced by some histological features. Our data showed a higher sensitivity when specimens contained necrosis, which indicated that only specimens with necrosis should be used for PCR to detect tuberculosis.

Four-Week Repeated Intravenous Dose Toxicity and Toxicokinetic Study of TS-DP2, a Novel Human Granulocyte Colony Stimulating Factor in Rats.

TS-DP2 is a recombinant human granulocyte colony stimulating factor (rhG-CSF) manufactured by TS Corporation. We conducted a four-week study of TS-DP2 (test article) in repeated intravenous doses in male and female Sprague-Dawley (SD) rats. Lenograstim was used as a reference article and was administered intravenously at a dose of 1000 µg/kg/day. Rats received TS-DP2 intravenously at doses of 250, 500, and 1000 µg/kg/day once daily for 4 weeks, and evaluated following a 2-week recovery period. Edema in the hind limbs and loss of mean body weight and body weight gain were observed in both the highest dose group of TS-DP2 and the lenograstim group in male rats. Fibro-osseous lesions were observed in the lenograstim group in both sexes, and at all groups of TS-DP2 in males, and at doses of TS-DP2 500 µg/kg/day and higher in females. The lesion was considered a toxicological change. Therefore, bone is the primary toxicological target of TS-DP2. The lowest observed adverse effect level (LOAEL) in males was 250 µg/kg/day, and no observed adverse effect level (NOAEL) in females was 250 µg/kg/day in this study. In the toxicokinetic study, the serum concentrations of G-CSF were maintained until 8 hr after administration. The systemic exposures (AUC0-24h and C0) were not markedly different between male and female rats, between the administration periods, or between TS-DP2 and lenograstim. In conclusion, TS-DP2 shows toxicological similarity to lenograstim over 4-weeks of repeated doses in rats.

Performance enhancement in inverted solar cells by interfacial modification of ZnO nanoparticle buffer layer.

Polymer solar cells (PSCs) have attracted increasing attention in recent years. The rapid progress and mounting interest suggest the feasibility of PSC commercialization. However, critical issues such as stability and the weak nature of their interfaces posses quite a challenge. In the context of improving stability, PSCs with inverted geometry consising of inorganic oxide layer acting as an n-buffer offer quite the panacea. Zinc oxide (ZnO) is one of the most preferred semiconducting wide band gap oxides as an efficient cathode layer that effectively extracts and transports photoelectrons from the acceptor to the conducting indium-doped tin oxide (ITO) due to its high conductivity and transparency. However, the existence of a back charge transfer from metal oxides to electron-donating conjugated polymer and poor contact with the bulk heterojunction (BHJ) active layer results in serious interfacial recombination and leads to relatively low photovoltaic performance. One approach to improving the performance and charge selectivity of these types of inverted devices consists of modifying the interface between the inorganic metal oxide (e.g., ZnO) and organic active layer using a sub-monolayer of interfacial materials (e.g., functional dyes). In this work, we demonstrate that the photovoltaic parameters of inverted solar cells comprising a thin overlayer of functional dyes over ZnO nanoparticle as an n-buffer layer are highly influenced by the anchoring groups they possess. While an inverted PSC containing an n-buffer of only ZnO exhibited an overall power conversion efficiency (PCE) of 2.87%, the devices with an interlayer of dyes containing functional cyano-carboxylic, cyano-cyano, and carboxylic groups exhibited PCE of 3.52%, 3.39%, and 3.21%, respectively, due to increased forward charge collection resulting from enhanced electronic coupling between the ZnO and BHJ active layers.

EGFR Gene Amplification and Protein Expression in Invasive Ductal Carcinoma of the Breast.

BACKGROUND: The epidermal growth factor receptor (EGFR) is a surrogate marker for basal-like breast cancer. A recent study suggested that EGFR may be used as a target for breast cancer treatment. METHODS: A total of 706 invasive ductal carcinomas (IDC) of the breast were immunophenotyped, and 82 cases with EGFR protein expression were studied for EGFR gene amplification. RESULTS: EGFR protein was expressed in 121 of 706 IDCs (17.1%); 5.9% were of luminal type, 25.3% of epidermal growth factor receptor 2 (HER-2) type, and 79.3% of basal-like tumors. EGFR gene amplification and high polysomy (fluorescent in situ hybridization [FISH]-positive) were found in 18 of 82 cases (22.0%); 41.2% of the HER-2(+), EGFR(+), cytokeratin 5/6(-) (CK5/6(-)) group, 11.2% of the HER-2(-), EGFR(+), CK5/6(-) group, and 19.1% of the HER-2(-), EGFR(+), CK5/6(+) group. FISH-positive cases were detected in 8.3% of the EGFR protein 1(+) expression cases, 15.9% of 2(+) expression cases, and 38.5% of 3(+) expression cases. In group 2, the tumors had a high Ki-67 labeling (>60%), but the patients showed better disease-free survival than those with tumors that co-expressed HER-2 or CK5/6. CONCLUSIONS: EGFR-directed therapy can be considered in breast cancer patients with EGFR protein overexpression and gene amplification, and its therapeutic implication should be determined in HER-2 type breast cancer patients.

Structural characterization of de novo designed L5K5W model peptide isomers with potent antimicrobial and varied hemolytic activities.

In an effort to develop short antimicrobial peptides with simple amino acid compositions, we generated a series of undecapeptide isomers having the L(5)K(5)W formula. Amino acid sequences were designed to be perfectly amphipathic when folded into a helical conformation by converging leucines onto one side and lysines onto the other side of the helical axis. The single tryptophans, whose positions were varied in the primary structures, were located commonly at the critical amphipathic interface in the helical wheel projection. Helical conformations and the tryptophanyl environments of the 11 L(5)K(5)W peptides were confirmed and characterized by circular dichroism, fluorescence and nuclear magnetic resonance spectroscopy. All of the isomers exhibited a potent, broad-spectrum of antibacterial activity with just a slight variance in individual potency, whereas their hemolytic activities against human erythrocytes were significantly diversified. Interestingly, helical dispositions and fluorescence blue shifts of the peptides in aqueous trifluoroethanol solutions, rather than in detergent micelles, showed a marked linear correlation with their hemolytic potency. These results demonstrate that our de novo design strategy for amphipathic helical model peptides is effective for developing novel antimicrobial peptides and their hemolytic activities can be estimated in correlation with structural parameters.

Verification of the interdomain contact site in the inactive monomer, and the domain-swapped fold in the active dimer of Hsp33 in solution.

Upon dimerization by oxidation, Hsp33 functions as a molecular chaperone in prokaryotes. Previously published structures of both the inactive and active species are of doubtful relevance to the solution conformations since the inactive (reduced) crystal structure was dimeric, while the active (oxidized) species was crystallized with a truncation of its regulation domain. The interdomain contact site of the inactive monomer, identified in this work, is consistent with that previously observed in the reduced dimer crystal. In contrast, fluorescence quenching of the active dimer contradicted the results expected from the domain-swapped fold observed in the truncated dimer crystal. The results of this study provide important new information concerning controversial issues in the activation process of Hsp33.

Identification of a novel recombinant mutation in Korean patients with Gaucher disease using a long-range PCR approach.

Gaucher disease (GD) is an autosomal recessive, lysosomal disorder caused by mutations in the gene for the ß-glucocerebrosidase (GBA) enzyme. Presence of the non-functional GBAP pseudogene, which shares high sequence similarity with the functional GBA gene, has made it difficult to carry out molecular analyses of GD, especially recombinant mutations. Using a long-range PCR approach that has been skillfully devised for the easy detection of GBA recombinant mutations, we identified four recombinant mutations including two gene conversion alleles, Rec 1a and Rec 8a, one reciprocal gene fusion allele, Rec 1b, and one reciprocal gene duplication allele, Rec 7b, in Korean patients with GD. Rec 8a, in which the GBAP pseudogene sequence from intron 5 to exon 11 is substituted for the GBA gene is a novel recombinant mutation. All mutations were confirmed by full sequencing of PCR amplicons and/or Southern blot analysis. These results indicate that the usage of long-range PCR may allow the rapid and accurate detection of GBA recombinant mutations and contribute to the improvement of genotyping efficiency in GD patients.

De novo generation of short antimicrobial peptides with simple amino acid composition.

As potential therapeutic agents, antimicrobial peptides with shorter length and simpler amino acid composition can be better candidates for clinical and commercial development. Here, we attempted de novo design of short (5- to 11-residue) antimicrobial peptides with three kinds of amino acids. Amphipathic helical properties were conferred by using leucines and lysines and two tryptophan residues were positioned at the critical amphipathic interface between the hydrophilic ending side and the hydrophobic starting side. According to this specified rule, 12 model peptides were generated and their helical propensity was confirmed by circular dichroism spectroscopy. Antimicrobial and hemolytic activities were compared with those of the known 12-residue peptide agent, omiganan, which is currently under therapeutic and commercial development. Antimicrobial activities against Gram-negative and Gram-positive bacteria, including a multi-drug resistant strain, were observed for certain 7- to 11-residue models. Among them, the most potent activity was found for a 9-residue peptide (L5K2W2), although it also had severe hemolytic activity. Alternatively, an 11-residue peptide (L4K5W2) with little hemolytic activity was potentially the most useful agent, as it showed higher antibacterial activity than omiganan. These results not only suggest useful candidates for novel antibiotic development, but also provide an efficient strategy to design such peptides.