Rapid and specific detection of Trichophyton rubrum and Trichophyton mentagrophytes using a loop-mediated isothermal amplification assay.

Trichophyton rubrum and Trichophyton mentagrophytes are the main causative pathogens of onychomycosis. However, the sensitivity and specificity of conventional microscopic tests are insufficient for reliable diagnoses of onychomycosis. In this study, we developed loop-mediated isothermal amplification (LAMP) assays for the rapid and specific identification of the two major Trichophytons spp. We designed LAMP primers targeting the internal transcribed spacer 1 region of the T. rubrum and T. mentagrophytes. Through rigorous optimization of the reaction conditions, we defined a universal reaction condition for both LAMP assays.

Preputial gland adenoma in a wild nutria (Myocastor coypus): a case report.

Tumor incidence in wild mammals is reportedly very low. Wild nutria, a large rodent, is known to carry many infectious diseases, but rarely exhibits neoplastic diseases. We necropsied a male wild nutria and found a large nodular mass in the left inguinal region, adjacent to the penis. Histopathologically, the mass was diagnosed as preputial gland adenoma. Spontaneous preputial gland adenomas are extremely rare in all animals. Moreover, reports of tumors in nutrias have been limited to adenocarcinomas of the lungs and uterus, as well as subcutaneous fibromas. Here, we describe preputial gland adenoma in a wild nutria.

Composition change-driven texturing and doping in solution-processed SnSe thermoelectric thin films.

The discovery of SnSe single crystals with record high thermoelectric efficiency along the b-axis has led to the search for ways to synthesize polycrystalline SnSe with similar efficiencies. However, due to weak texturing and difficulties in doping, such high thermoelectric efficiencies have not been realized in polycrystals or thin films. Here, we show that highly textured and hole doped SnSe thin films with thermoelectric power factors at the single crystal level can be prepared by solution process. Purification step in the synthetic process produced a SnSe-based chalcogenidometallate precursor, which decomposes to form the SnSe2 phase. We show that the strong textures of the thin films in the b-c plane originate from the transition of two dimensional SnSe2 to SnSe. This composition change-driven transition offers wide control over composition and doping of the thin films. Our optimum SnSe thin films exhibit a thermoelectric power factor of 4.27 µW cm-1 K-2.

A Case of Fascioliasis in A Wild Nutria, Myocastor coypus, in Republic of Korea.

A total of 44 adult or juvenile nutrias were necropsied for disease survey. A large nodule was found in the liver of a nutria. The histopathological specimen of the hepatic nodule was microscopically examined, and sectional worms were found in the bile duct. The worms showed a tegument with spines, highly branches of vitelline glands and intestine. Finally, we histopathologically confirmed fascioliasis in a wild nutria. In the present study, a case of fascioliasis in a wild nutria is first confirmed in Korea.

Enhancing p-Type Thermoelectric Performances of Polycrystalline SnSe via Tuning Phase Transition Temperature.

SnSe emerges as a new class of thermoelectric materials since the recent discovery of an ultrahigh thermoelectric figure of merit in its single crystals. Achieving such performance in the polycrystalline counterpart is still challenging and requires fundamental understandings of its electrical and thermal transport properties as well as structural chemistry. Here we demonstrate a new strategy of improving conversion efficiency of bulk polycrystalline SnSe thermoelectrics. We show that PbSe alloying decreases the transition temperature between Pnma and Cmcm phases and thereby can serve as a means of controlling its onset temperature. Along with 1% Na doping, delicate control of the alloying fraction markedly enhances electrical conductivity by earlier initiation of bipolar conduction while reducing lattice thermal conductivity by alloy and point defect scattering simultaneously. As a result, a remarkably high peak ZT of ∼1.2 at 773 K as well as average ZT of ∼0.5 from RT to 773 K is achieved for Na0.01(Sn1-xPbx)0.99Se. Surprisingly, spherical-aberration corrected scanning transmission electron microscopic studies reveal that NaySn1-xPbxSe (0 < x ≤ 0.2; y = 0, 0.01) alloys spontaneously form nanoscale particles with a typical size of ∼5-10 nm embedded inside the bulk matrix, rather than solid solutions as previously believed. This unexpected feature results in further reduction in their lattice thermal conductivity.

Anomalous transport properties in boron and phosphorus co-doped armchair graphene nanoribbons.

Multi-element doping of graphene could potentially provide functionalities that are not available in the single-element doping approach, but it has not been actively studied so far. Carrying out first-principles calculations, we study the structural, electronic, and transport properties of B-P edge-co-doped armchair graphene nanoribbons (aGNRs). We find that the B, P-complex edge-doped aGNRs exhibit an n-type transport behavior, which is counterintuitive considering the p-type and bipolar characters of the corresponding B- and P-doped aGNRs, respectively. Moreover, we show that the n-type property of B, P co-doped aGNRs is superior to that of representative N-doped aGNRs in terms of preserving the valence band edge conductance spectrum. Analyzing the mechanisms, we demonstrate that the structural distortion rather than chemical valence induces the anomalous donor character of B, P co-doped aGNRs. We thus propose a systematic modification of GNR atomic structures via co-doping as a novel approach to control charge transport characteristics of GNRs.

Extremely Large Gate Modulation in Vertical Graphene/WSe2 Heterojunction Barristor Based on a Novel Transport Mechanism.

A WSe2 -based vertical graphene-transition metal dichalcogenide heterojunction barristor shows an unprecedented on-current increase with decreasing temperature and an extremely high on/off-current ratio of 5 × 10(7) at 180 K (3 × 10(4) at room temperature). These features originate from a trap-assisted tunneling process involving WSe2 defect states aligned near the graphene Dirac point.

Carbon nanobuds based on carbon nanotube caps: a first-principles study.

Based on density functional theory calculations, we here show that the formation of a fullerene C60 carbon "nanobud" (CNB) on carbon nanotube (CNT) caps is energetically more favorable than that on CNT sidewalls. The dominant CNB formation mode for CNT caps is found to be the [2 + 2] cycloaddition reaction as in the conventional CNT sidewall case. However, it is identified to be exothermic in contrast to the endothermic reaction on CNT sidewalls. Computed reaction pathways further demonstrate that the formation (dissociation) barrier for the CNT cap-based CNB is slightly lower (significantly higher) than that of the CNT sidewall-based CNB, indicating an easier CNB formation as well as a higher structural stability. Additionally, performing matrix Green's function calculations, we study the charge transport properties of the CNB/metal electrode interfaces, and show that the C60 bonding to the CNT cap or open end induces resonant transmissions near the Fermi level. It is also found that the good electronic linkage in the CNT cap-C60 cycloaddition bonds results in the absence of quantum interference patterns, which contrasts with the case of the CNB formed on an open-ended CNT that shows a Fano resonance profile.

Highly sensitive and selective sugar detection by terahertz nano-antennas.

Molecular recognition and discrimination of carbohydrates are important because carbohydrates perform essential roles in most living organisms for energy metabolism and cell-to-cell communication. Nevertheless, it is difficult to identify or distinguish various carbohydrate molecules owing to the lack of a significant distinction in the physical or chemical characteristics. Although there has been considerable effort to develop a sensing platform for individual carbohydrates selectively using chemical receptors or an ensemble array, their detection and discrimination limits have been as high in the millimolar concentration range. Here we show a highly sensitive and selective detection method for the discrimination of carbohydrate molecules using nano-slot-antenna array-based sensing chips which operate in the terahertz (THz) frequency range (0.5-2.5 THz). This THz metamaterial sensing tool recognizes various types of carbohydrate molecules over a wide range of molecular concentrations. Strongly localized and enhanced terahertz transmission by nano-antennas can effectively increase the molecular absorption cross sections, thereby enabling the detection of these molecules even at low concentrations. We verified the performance of nano-antenna sensing chip by both THz spectra and images of transmittance. Screening and identification of various carbohydrates can be applied to test even real market beverages with a high sensitivity and selectivity.

Atomistic mechanisms of codoping-induced p- to n-type conversion in nitrogen-doped graphene.

It was recently shown that nitrogen-doped graphene (NG) can exhibit both p- and n-type characters depending on the C-N bonding nature, which represents a significant bottleneck for the development of graphene-based electronics. Based on first-principles calculations, we herein scrutinize the correlations between the atomic and electronic structures of NG and particularly explore the feasibility of converting p-type NG with pyridinic, pyrrolic, and nitrilic N atoms into n- or bipolar type by introducing an additional dopant atom. Of the nine candidates B, C, O, F, Al, Si, P, S, and Cl, we find that B-, Al-, and P-codoping can anneal even relatively large vacancy defects in p-type NG. It will be also shown that, while the NG with pyridinic N can be converted into the n-type via codoping, only a bipolar type conversion can be achieved for the NG with nitrilic or pyrrolic N. The amount of work function reduction was up to 0.64 eV for the pyridinic N next to a monovacancy. The atomistic origin of such diverse type changes is analyzed based on Mulliken and crystal orbital Hamiltonian populations, which provide us with a framework to connect the local bonding chemistry with the macroscopic electronic structure in doped and/or defective graphene. Moreover, we demonstrate that the proposed codoping scheme can recover the excellent charge transport properties of pristine graphene. Both the electronic type conversion and conductance recovery in codoped NG should have significant implications for the electronic and energy device applications.

Two lung masses with different responses to pemetrexed.

We described here a patient who had two lung masses. Although the two masses had the same histology and a similar good response to initial chemotherapy with gemcitabine and carboplatin, the response to pemetrexed as a second-line treatment was different after re-growth of the tumors. These two lung masses could have originated from different clones or they could have progressed through different paths of molecular pathogenesis after metastasis, which would lead to different tumor characteristics, including their chemosensitivity. Regardless of their pathogenetic mechanisms, it seems important to recognize that tumors with the same histology that develop in one patient can have different responses to drugs.

Myasthenia gravis in ectopic thymoma presenting as pleural masses.

Multiple pleural masses were found in a 52-year-old female suggesting malignant mesothelioma or pleural metastasis from other malignancy. Unexpectedly, ectopic thymoma was diagnosed by percutaneous needle biopsy and subsequent myasthenia gravis developed during admission. Although ectopic thymoma in pleura is unusual, it should be considered as one of the possible etiologies causing diffuse pleural masses.