Trolox‐induced cardiac differentiation is mediated by the inhibition of Wnt/β‐catenin signaling in human embryonic stem cells

Cardiac differentiation of human pluripotent stem cells may be induced under chemically defined conditions, wherein the regulation of Wnt/β‐catenin pathway is often desirable. Here, we examined the effect of trolox, a vitamin E analog, on the cardiac differentiation of human embryonic stem cells (hESCs). 6‐Hydroxy‐2,5,7,8‐tetramethylchromane‐2‐carboxylic acid (Trolox) significantly enhanced cardiac differentiation in a time‐ and dose‐dependent manner after the mesodermal differentiation of hESCs. Trolox promoted hESC cardiac differentiation through its inhibitory activity against the Wnt/β‐catenin pathway. This study demonstrates an efficient cardiac differentiation method and reveals a novel Wnt/β‐catenin regulator.     

Cold Antisolvent Bathing Derived Highly Efficient Large‐Area Perovskite Solar Cells

Scaling large‐area solar cells is in high demand for the commercialization of perovskite solar cells (PSCs) with a high power‐conversion efficiency (PCE). However, few roll‐to‐roll‐compatible deposition methods for the formation of highly oriented uniform perovskite films are reported. Herein, a facile cold antisolvent bathing approach compatible with large‐area fabrication is introduced. The wet precursor films are submerged in a cold antisolvent bath at 0 °C, and the retarded nucleation and growth kinetics allow highly oriented perovskite to be grown along the [110] and [220] directions, perpendicular to the substrate. The high degree of the preferred crystal orientation benefits the effective charge extraction and reduces the amount of inter‐ and intra‐grain defects inside the perovskite films, improving the PCE from 16.48% (ambient‐bathed solar cell) to 18.50% (cold‐bathed counterpart). The cold antisolvent bathing method is employed for the fabrication of large‐area (8 × 10 cm²) PSCs with uniform photovoltaic device parameters, thereby verifying the scale‐up capability of the method.     

Super‐achromatic optical coherence tomography capsule for ultrahigh‐resolution imaging of esophagus

Endoscopic optical coherence tomography (OCT) is a noninvasive technology allowing for imaging of tissue microanatomies of luminal organs in real time. Conventional endoscopic OCT operates at 1300 nm wavelength region with a suboptimal axial resolution limited to 8‐20 μm. In this paper, we present the first ultrahigh‐resolution tethered OCT capsule operating at 800 nm and offering about 3‐ to 4‐fold improvement of axial resolution (plus enhanced imaging contrast). The capsule uses diffractive optics to manage chromatic aberration over a full ~200 nm spectral bandwidth centering around 830 nm, enabling to achieve super‐achromaticity and an axial resolution of ~2.6 μm in air. The performance of the OCT capsule is demonstrated by volumetric imaging of swine esophagus ex vivo and sheep esophagus in vivo, where fine anatomic structures including the sub‐epithelial layers are clearly identified. The ultrahigh resolution and excellent imaging contrast at 800 nm of the tethered capsule suggest the potential of the technology as an enabling tool for surveillance of early esophageal diseases on awake patients without the need for sedation.      

Interaction of HCV core protein with 14-3-3epsilon protein releases Bax to activate apoptosis

Through protein-protein binding assays, we found that HCV core protein interacted with 14-3-3epsilon protein. Interestingly, the expression of HCV core protein induced apoptosis in 293T cells. The apoptosis induced by core expression is accompanied by translocation of Bax from cytosol to mitochondria, disruption of mitochondrial membrane potential, cytochrome c release, and activation of caspase-9 and caspase-3. Furthermore, over-expression of 14-3-3epsilon inhibited the core-induced apoptosis and Bax translocation to mitochondria. These results indicate that HCV core protein induces the Bax-mediated apoptosis by interacting with 14-3-3epsilon protein in 293T cells. As a mechanism of apoptosis induction by HCV core, we propose that the interaction of HCV core with 14-3-3epsilon causes the dissociation of Bax from the Bax/14-3-3epsilon complex in cytosol, and the free Bax protein provokes activation of the mitochondrial apoptotic pathway.     

A mushroom lectin from ascomycete Cordyceps militaris

A mushroom lectin has been purified from ascomycete Cordyceps militaris, which is one of the most popular mushrooms in eastern Asia used as a nutraceutical and in traditional Chinese medicine. This lectin, designated CML, exhibited hemagglutination activity in mouse and rat erythrocytes, but not in human ABO erythrocytes. SDS-PAGE of CML revealed a single band with a molecular mass of 31.0 kDa under both nonreducing and reducing conditions that was stained by silver nitrate, and a 31.4 kDa peak in a Superdex-200 HR gel-filtration column. The hemagglutination activity was inhibited by sialoglycoproteins, but not in by mono- or disaccharides, asialoglycoproteins, or de-O-acetylated glycoprotein. The activity was maximal at pH 6.0–9.1 and at temperatures below 50 °C. Circular dichroism spectrum analysis revealed that CML comprises 27% α-helix, 12% β-sheets, 29% β-turns, and 32% random coils. Its binding specificity and secondary structure are similar to those of a fungal lectin from Arthrobotrys oligospora. However, the N-terminal amino acid sequence of CML differs greatly from those of other lectins. CML exhibits mitogenic activity against mouse splenocytes.     

Comparison of Neuronal Death,Blood–Brain Barrier Leakage and Inflammatory Cytokine Expression in the Hippocampal CA1 Region Following Mild and Severe Transient Forebrain Ischemia in Gerbils

Neurochemical Research - Transient ischemia in the brain causes blood–brain barrier (BBB) breakdown and dysfunction, which is related to ischemia-induced neuronal damage. Leakage of plasma...     

Incidence and molecular characterization of hepatitis A viruses in Korean surface water between 2007 and 2010

Several bodies of surface water in Korea were surveyed for the presence of hepatitis A virus (HAV) between 2007 and 2010. Of 265 surface water samples, 9 (3.4%) were HAV‐positive. HAVs were mainly detected in the summer (3/62, 4.8%) and spring (4/96, 4.2%) seasons. Comparing different water sources, the highest prevalence (6.6%) of positive samples was seen in lake water, four HAV‐positive samples being from lakes. Comparing prevalence rates across the four representative Korean basin systems, no HAVs were found in the Han or Nakdong river basins. The highest HAV prevalence was found in samples from the Yeongsan river and other basins (6.3%); the Geum/Seom river was also found to have a high HAV prevalence (5.7%). HAVs from the nine positive samples were then sequenced and analyzed phylogenetically. Two of the HAVs belong to genotype IA and fall within the same cluster as HAVs 6‐3(ASAN4) (EU049548), KANSAN‐PS1 (EU049554), and ASAN‐KM (EU049563), which were collected from the stools of patients with gastroenteritis in Korea. The seven other HAV nucleotide sequences belong to the genotype IB cluster. This is the first nationwide surveillance of HAV in major Korean water sources.     

Characterization of antifungal activity of Paenibacillus ehimensis KWN38 against soilborne phytopathogenic fungi belonging to various taxonomic groups

Soilborne fungal phytopathogens cause significant losses in many economically important crops and vegetables. The only way to control these devastating pathogens is by using higher doses of fungicides which not only increase the cost of production but also cause significant damage to the environment. Therefore alternate control measures are always looked for. In the present study, an antagonistic strain was isolated from the soil of the pepper fields around the seashore of Jellanamdo, South Korea and identified as Paenibacillus ehimensis KWN38 based on 16S rRNA sequencing. The strain showed high antifungal activity against six tested fungal pathogens belonging to various taxonomic groups on dual culture plates. Furthermore, the strain produced volatile antimicrobial compounds which had strong fungal growth inhibitory effect. The strain also showed high chitinase, cellulase, glucanase and protease activities. The hyphal morphologies of Rhizoctonia solani AG-1 (IA), Fusarium oxysporum f.sp. lycopersici and Phytophthora capsici were significantly destroyed by the crude enzymes and butanol extract from the culture supernatant and the affected hyphae showed abnormal bending, tip curling, and irregular branching. Hence, Paenibacillus ehimensis KWN38 is considered as a potential biocontrol agent of the soil-borne fungi causing plant diseases which is an important perspective of the present study.     

Molecular characterization of a heat inducible rice gene,OsHSP1, and implications for rice thermotolerance

Higher plants have acquired complex molecular mechanisms to withstand heat stress through years of natural evolutionary processes. Although physiological responses to elevated temperatures have been well studied, thermotolerance mechanisms at the molecular level are poorly understood in rice plants. In order to identify the genes involved in the thermotolerance of rice, we used a publicly available microarray dataset and identified a number of heat stress-responsive genes. Herein, we report details of the rice gene OsHSP1, which is upregulated by heat stress. In addition, OsHSP1 is highly expressed when exposed to salt and osmotic treatments but not cold treatment. Sequence analysis indicated that OsHSP1 belongs to the heat shock protein 90 family of genes. The biological function of OsHSP1 was investigated by heterologous overexpression in Arabidopsis. Transgenic Arabidopsis overexpressing the OsHSP1 gene exhibited enhanced thermotolerance but was hypersensitive under salt and osmotic stresses. Subcellular localization analysis indicated that the OsHSP1 protein is predominantly targeted to the cytosol and nucleus under heat stress. The coexpression network showed 39 interactions for the functionally interacting genes of OsHSP1. Taken together, these findings suggest that OsHSP1 is a heat-inducible gene that may play an important role in the thermotolerance of rice.