Performance Enhancement in Powder-Fabricated Cu2(ZnSn)Se4 Solar Cell by Roll Compression.

Despite the improved conversion efficiency of Cu2(ZnSn)Se4 (CZTSe) solar cells, their roll-to-roll fabrication nonetheless leads to low performance. The selenization time and temperature are typically considered major parameters for a powder-based CZTSe film; meanwhile, the importance of the densification during the roll-to-roll process is often overlooked. The densification process is related to the porosity of the light-absorbing layer, where high porosity lowers cell performance. In this study, we fabricated a dense CZTSe absorber layer as a method of controlling the compression of a powder precursor (Cu1.7(Zn1.2Sn1.0)S4.0 (CZTS)) during the roll-press process. The increased particle packing density of the CZTS layer was crucial in sintering the powder layer into a dense film and preventing severe selenization of the Mo back electrode. The pressed absorber layer of the CZTSe solar cell exhibited a more uniform chemical composition determined using dynamic secondary ion mass spectrometry (SIMS). Under the AM 1.5G illumination condition, the power conversion efficiency of the pressed solar cell was 6.82%, while the unpressed one was 4.90%.

Ginsenosides Rk1 and Rg5 inhibit transforming growth factor-ß1-induced epithelial-mesenchymal transition and suppress migration, invasion, anoikis resistance, and development of stem-like features in lung cancer.

BACKGROUND: Lung cancer has a high incidence worldwide, and most lung cancer-associated deaths are attributable to cancer metastasis. Although several medicinal properties of Panax ginseng Meyer have been reported, the effect of ginsenosides Rk1 and Rg5 on epithelial-mesenchymal transition (EMT) stimulated by transforming growth factor beta 1 (TGF- ß1) and self-renewal in A549 cells is relatively unknown. METHODS: We treated TGF-ß1 or alternatively Rk1 and Rg5 in A549 cells. We used western blot analysis, real-time polymerase chain reaction (qPCR), wound healing assay, Matrigel invasion assay, and anoikis assays to determine the effect of Rk1 and Rg5 on TGF-mediated EMT in lung cancer cell. In addition, we performed tumorsphere formation assays and real-time PCR to evaluate the stem-like properties. RESULTS: EMT is induced by TGF-ß1 in A549 cells causing the development of cancer stem-like features. Expression of E-cadherin, an epithelial marker, decreased and an increase in vimentin expression was noted. Cell mobility, invasiveness, and anoikis resistance were enhanced with TGF-ß1 treatment. In addition, the expression of stem cell markers, CD44, and CD133, was also increased. Treatment with Rk1 and Rg5 suppressed EMT by TGF-ß1 and the development of stemness in a dose-dependent manner. Additionally, Rk1 and Rg5 markedly suppressed TGF-ß1-induced metalloproteinase-2/9 (MMP2/9) activity, and activation of Smad2/3 and nuclear factor kappa B/extra-cellular signal regulated kinases (NF-kB/ERK) pathways in lung cancer cells. CONCLUSIONS: Rk1 and Rg5 regulate the EMT inducing TGF-ß1 by suppressing the Smad and NF-κB/ERK pathways (non-Smad pathway).

Hypoxylonol F Isolated from Annulohypoxylon annulatum Improves Insulin Secretion by Regulating Pancreatic ß-cell Metabolism.

Insulin plays a key role in glucose homeostasis and is hence used to treat hyperglycemia, the main characteristic of diabetes mellitus. Annulohypoxylon annulatum is an inedible ball-shaped wood-rotting fungus, and hypoxylon F is one of the major compounds of A. annulatum. The aim of this study is to evaluate the effects of hypoxylonol F isolated from A. annulatum on insulin secretion in INS-1 pancreatic ß-cells and demonstrate the molecular mechanisms involved. Glucose-stimulated insulin secretion (GSIS) values were evaluated using a rat insulin ELISA kit. Moreover, the expression of proteins related to pancreatic ß-cell metabolism and insulin secretion was evaluated using Western blotting. Hypoxylonol F isolated from A. annulatum was found to significantly enhance glucose-stimulated insulin secretion without inducing cytotoxicity. Additionally, hypoxylonol F enhanced insulin receptor substrate-2 (IRS-2) levels and activated the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway. Interestingly, it also modulated the expression of peroxisome proliferator-activated receptor γ (PPARγ) and pancreatic and duodenal homeobox 1 (PDX-1). Our findings showed that A. annulatum and its bioactive compounds are capable of improving insulin secretion by pancreatic ß-cells. This suggests that A. annulatum can be used as a therapeutic agent to treat diabetes.

Synthesis, Structure Revision, and Cytotoxicity of Nocarbenzoxazole G.

The total synthesis of nocarbenzoxazoles F (1) and G (2), originally obtained from the marine-derived halophilic bacterial strain Nocardiopsis lucentensis DSM 44048, was achieved via a simple and versatile route involving microwave-assisted construction of a benzoxazole skeleton, followed by carbon-carbon bond formation with the corresponding aryl bromides. Unfortunately, the 1H and 13C NMR spectra of natural nocarbenzoxazole G did not agree with those of the synthesized compound. In particular, the spectra of the isolated and synthesized compounds showed considerable differences in the signals from the protons and carbons in the aryl group. The revised structure was validated by the total synthesis of the actual nocarbenzoxazole G (8c) molecule, which is a regioisomer of the compound that was reported earlier as nocarbenzoxazole G. The synthesized derivatives showed specific cytotoxicity to the human cervical carcinoma cell line, HeLa, but did not have any remarkable effect on the other cell lines.

Application of microwave-irradiation technique in deglycosylation of ginsenosides for improving apoptosis induction in human melanoma SK-MEL-2 cells.

To increase the contents of medicinally effective ginsenosides, we used high-temperature and high-pressure thermal processing of ginseng by exposing it to microwave irradiation. To determine the anti-melanoma effect, the malignant melanoma SK-MEL-2 cell line was treated with an extract of microwave-irradiated ginseng. Microwave irradiation caused changes in the ginsenoside contents: the amounts of ginsenosides Rg1, Re, Rb1, Rb2, Rc, and Rd were disappeared, while those of less polar ginsenosides, such as Rg3, Rg5, and Rk1, were increased. In particular, the contents of Rk1 and Rg5 markedly increased. Melanoma cells treated with the microwave-irradiated ginseng extract showed markedly increased cell death. The results indicate that the microwave-irradiated ginseng extract induced melanoma cell death via the apoptotic pathway and that the cytotoxic effect of the microwave-irradiated ginseng extract is attributable to the increased contents of specific ginsenosides.

Renoprotective Effects of Hypoxylonol C and F Isolated from Hypoxylon truncatum against Cisplatin-Induced Cytotoxicity in LLC-PK1 Cells.

Although cisplatin is the standard platinum-based anticancer drug used to treat various solid tumors, it can cause damage in normal kidney cells. Protective strategies against cisplatin-induced nephrotoxicity are, therefore, clinically important and urgently required. To address this challenge, we investigated the renoprotective effects of Hypoxylontruncatum, a ball-shaped wood-rotting fungus. Chemical investigation of the active fraction from the methanol extract of H.truncatum resulted in the isolation and identification of the renoprotective compounds, hypoxylonol C and F, which ameliorated cisplatin-induced nephrotoxicity to approximately 80% of the control value at 5 µM. The mechanism of this effect was further investigated using hypoxylonol F, which showed a protective effect at the lowest concentration. Upregulated phosphorylation of p38, extracellular signal-regulated kinases, and c-Jun N-terminal kinases following cisplatin treatment were markedly decreased after pre-treatment with hypoxylonol F. In addition, the protein expression level of cleaved caspase-3 was significantly reduced after co-treatment with hypoxylonol F. These results show that blocking the mitogen-activated protein kinase signaling cascade plays a critical role in mediating the renoprotective effect of hypoxylonol F isolated from H.truncatum fruiting bodies.

Preparation of monolithic cu(In0.7Ga0.3)Se2 nanopowders and subsequent fabrication of sintered CIGS films.

Cu(In,Ga)Se2 (CIGS) is a compound semiconductor and is one of the most attractive light-absorbing materials for use in thin film solar cells. Among the various approaches to prepare CIGS thin films, the powder process offers an extremely simple and materials-efficient method. Here, we report the mechano-chemical preparation of CIGS compound powders suitable for fabrication of CIGS films by a powder process. We found that the CIGS phase was formed from the elemental powders of Cu, In, and Se and liquid Ga using high energy milling process with a milling time as short as 40 min at 200 rpm due to a self-accelerating exothermic reaction. The morphology and size of the CIGS powders changed with a function of the milling speed (100-300 rpm), leading to an optimal condition of milling at 200 rpm for 120 min. We also found that it was difficult to obtain a monolithic phase of the CIGS powders without severe particle aggregation by mechano-chemical milling alone. Therefore, in combination with the milling, subsequent heat-treatment at 300 degrees C was performed, which successfully provided monolithic CIGS nanopowders suitable for powder process. When a thin film was fabricated from the monolithic CIGS nanopowders, a highly dense film with large crystalline grains was obtained. The CIGS film preserved its chemical composition of CuIn0.7Ga0.3Se2 after sintering as evidenced by Raman spectroscopy, EDS and SAED pattern of transmission electron microscopy. The film was also found suitable for a light absorbing layer of CIGS solar cells with its band gap energy of 1.14 eV evaluated by transmittance spectroscopy.

Flash pulmonary edema in a patient with unilateral renal artery stenosis and bilateral functioning kidneys.

Flash pulmonary edema typically exhibits sudden onset and resolves rapidly. It generally is associated with bilateral renal artery stenosis or unilateral stenosis in conjunction with a single functional kidney. We describe a patient who presented with flash pulmonary edema treated by percutaneous therapy with stent implantation. Our case is unique in that the flash pulmonary edema occurred in the setting of unilateral renal artery stenosis with bilateral functioning kidneys.

Correlation between levels of N-terminal pro-B-type natriuretic peptide and degrees of heart failure.

BACKGROUND: The N-terminal fragment of pro Brain Natriuretic Peptide (NT-pro BNP) is a neuro-hormone synthesized in the cardiac ventricles in response to increased wall tension. The purpose of this study was to assess the correlation between the NT-pro BNP levels and the New York Heart Association function class (NYHA Fc) of dyspnea and echocardiographic findings for the patients who visited our cardiology departments. METHODS: From October, 2002 to April, 2003, serum NT-pro BNP levels were measured in 348 patients who visited the Samsung Medical Center and the Jong Koo Lee Heart Clinic. RESULTS: The NT-pro BNP levels were increased with the progression of NYHA Fc of dyspnea (p < 0.001 by ANOVA), the increase in the systolic left ventricular internal dimension (p < 0.05), and the decrease in the ejection fraction (p < 0.01). For the NYHA Fc I patients, the NT-pro BNP levels were positively correlated with age (0 < 0.001) and left atrial size (p < 0.001). For the patients with ischemic heart disease, the NT-pro BNP levels were also positively correlated with the NYHA Fc (p < 0.001 by ANOVA). The NT-pro BNP levels were increased with the increase in the systolic (p < 0.001) and diastolic pressure (p = 0.017), the left ventricular internal dimension as well as the decrease in the ejection fraction (p < 0.001). The area under the receiver operating characteristic (ROC) curve for the NT-pro BNP levels was 0.994 (95% confidence interval, 0.979-0.999), and the most reliable cut-off level for the NT-pro BNP was 293.6 pg/mL. CONCLUSION: The NT-pro BNP levels were positively correlated with the NYHA Fc of dyspnea and the systolic dysfunction for the patients who visited our cardiology departments. A 300 pg/mL value for the NT-pro BNP cut-off point appears to be a sensitive level to differentiate dyspnea originating from an ailing heart or not for the patients who visited our cardiology departments.

[A case of serous cystadenoma of the pancreas communicating with the pancreatic duct].

Serous cystadenoma of the pancreas is a rare disease and is usually benign. Mucinous cystadenoma, another cystic neoplasm of the pancreas, has a malignant potential. Serous cystadenoma is usually composed of many small cysts lined by small, cuboidal or flattened cells containing abundant glycogen. With the finding of endoscopic retrograde pancreatography, a communication between the cyst and pancreatic duct is observed occasionally in the mucinous cystadenoma, but rarely in the case of serous cystadenoma of the pancreas. We experienced a case of serous cystadenoma of the pancreas that had a communication between a cyst and the pancreatic duct.

[Mesenchymal hamartoma of the liver in adults].

Mesenchymal hamartoma of the liver (MHL) is a rare benign tumor usually found in childhood, especially during the first two years. MHL is extremely rare in adults. Most reported cases present with a slow growing abdominal mass. It is thought to be a developmental anomaly and consists of bile ducts, hepatocytes and mesenchymal tissue. We report a case of mesenchymal hamartoma of the liver in an adult male with a brief review of the literature.

Use of GCDFP-15 (BRST-2) as a Specific Immunocytochemical Marker for Diagnosis of Gastric Metastasis of Breast Carcinoma.

Metastasis of breast cancer to the stomach is relatively uncommon and typically occurs in patients with disseminated diseases. This may cause difficulty in differentiating it from primary gastric carcinoma. The correct diagnosis of the primary source is important, since the treatment and prognosis of metastatic breast cancer is quite different from those of metastatic gastric cancer. Immunohistochemical staining with GCDFP-15 (gross cystic disease fluid protein-15) can be used to differentiate primary gastric carcinoma and gastric metastasis from breast cancer. We report two cases of gastric metastasis of breast cancer by describing their clinical course, illustrating the histologic findings, and showing the results of immunohistochemical staining with GCDFP-15.