In this study, the factors affecting the efficiency of 48 projects of private R&D institutes were analyzed using the Tobit model. Influencing factors were selected as open R&D network size, IT industry, interaction between R&D network size and IT industry, and type of R&D network cooperation. As a result of Tobit analysis, the R&D network size, the IT industry, and the type of R&D network cooperation were found to be significant. The larger the open R&D network size, the lower the efficiency, and the IT industry showed lower R&D efficiency than other industries. In addition, cooperation with universities and research institutes showed lower R&D efficiency than cooperation with companies. As a result of these studies, companies will be able to select and focus on cooperation with the outside in relations and investment allocation.
Fly ash consists of various metal oxides which can remove SO2 gas by the catalyst effect. When fly ash is added in the preparation process of pitch-based activated carbon, the pitch particles aggregate and fly ash is embedded in the activated carbon. To increase SO2 gas removal performance, activated carbon was prepared by surface-treated fly ash and petroleum-based pitch. Carboxyl groups were introduced into the fly ash by malic acid treatment. The introduced carboxyl groups acted as an activation agent to create micropore around the fly ash, and created micropores were exposed to the fly ash outside of the activated carbon. The exposed fly ash increased removal amount of SO2 gas by a catalytic effect of the metal oxides. The SO2 gas removal performance improved by 34% because of the catalyst effect of the exposed fly ash and improvement in the micropore structure in the activated carbon.
Equine follicle stimulating hormone receptor (eFSHR) has a large extracellular domain and an intracellular domain containing approximately 10 phosphorylation sites within the G protein-coupled receptor. This study was conducted to analyze the function of phosphorylation sties at the eFSHR C-terminal region. We constructed a mutant of eFSHR, in which the C-terminal cytoplasmic tail was truncated at residue 641 (eFSHR-t641). This removed 10 potential phosphorylation sites from the C-terminal region of the intracellular loop. The eFSHR-wild type (eFSHR-wt) and eFSHR-t641 cDNAs were subcloned into the pCMV-ARMS1-PK2 expression vector. These plasmids were transfected into PathHunter CHO-K1 Parental cells expressing β-arrestin 2 enzyme acceptor fusion protein and analyzed for agonist-induced cAMP response. The cAMP response in cells expressing eFSHR-t641 was lower than the response in cells expressing eFSHR-wt. EC50 values of eFSHR-wt and eFSHR-t641 were 1079 ng/mL and 1834 ng/mL, respectively. eFSHR-t641 was approximately 0.58-fold compared with that of eFSHR-wt. The maximal response in eFSHR-wt and eFSHR-t641 was 24.7 nM and 16.7 nM, respectively. The Rmax value of phosphorylation sites in eFSHR-t641 was also decreased to approximately 68.4% of that in eFSHR-wt. The collective data implicate that the phosphorylation sites in the eFSHR C-terminal region have a pivotal role in signal transduction in PathHunter CHO-K1 cells, and indicate that β-arrestin is involved in coupling the activated receptors to the internalization system.
Hepatic stellate cells (HSCs) play essential roles in normal and pathophysiological function in liver. In steady state, HSCs contribute to retinoid storage, immune tolerance, and extracellular matrix (ECM) homeostasis. Upon liver injury, they become activated and lead to morphological and functional changes. Studies have demonstrated that activation of HSCs by various stimuli such as toxins, microbial infection, or metabolic overload can promote the fibrotic changes in liver by production of ECM. Herein, we provide current knowledge about the basic characteristics of HSCs and the mechanism by which they are activated.
The salivary glands secrete saliva, which plays a role in the maintenance of a healthy oral environment. Under physiological conditions, saliva secretion within the acinar cells of the gland is regulated by stimulation of specific calcium (Ca2+) signaling mechanisms such as increases in the intracellular Ca2+ concentration ([Ca2+]i) via storeoperated Ca2+ entry, which involves components such as Orai1, transient receptor potential (TRP) canonical 1, stromal interaction molecules, and inositol 1,4,5-triphosphate (IP3) receptors (IP3Rs). Homer proteins are scaffold proteins that bind to G protein-coupled receptors, IP3Rs, ryanodine receptors, and TRP channels. However, their exact role in Ca2+ signaling in the salivary glands remains unknown. In the present study, we investigated the role of Homer2 in Ca2+ signaling and saliva secretion in parotid gland acinar cells under physiological conditions. Deletion of Homer2 (Homer2−/−) markedly decreased the amplitude of [Ca2+]i oscillations via the stimulation of carbachol, which is physiologically concentrated in parotid acinar cells, whereas the frequency of [Ca2+]i oscillations showed no difference between wild-type and Homer2−/− mice. Homer2−/− mice also showed a significant decrease in amylase release by carbachol in the parotid gland in a dose-dependent manner. These results suggest that Homer2 plays a critical role in maintaining [Ca2+]i concentration and secretion of saliva in mouse parotid gland acinar cells.
Cancer is the second leading cause of death worldwide and currently there are many approaches developing towards cancer treatment. Cancer treatments like chemotherapy and radiation therapy are often painful and have adverse effects. The mechanism of apoptosis is a complex process and it involves different pathways in its mechanism of action. Apoptosis can be caused by signals within the cell such as stress, or by extrinsic signals such as ligands binding to cell surface death receptors. The programmed cell death plays a important role in the several physiological and pathological processes. It plays important role in homeostasis. Flavonoids have gained importance as anticancer agents promoting cytotoxicity and apoptosis in cancer cells. Flavonoids are present in many medicinal plants which are a kind of ubiquitous natural products and essential active ingredients. They have strong biological activities with high efficiency and low toxicity, possessing good preventive and cure effects on different tumor forms. Flavonoids such as Scutellarein, Pectolinarigenin and Naringin have reported to possess significant anti-cancer effects on different cancer cell lines till date. In this review, we provide a summary about the anti-cancer effect of the three flavonoids and its mechanisms of action that can be used in future for understanding their potent anti-tumor properties.
The development of drugs from natural plant sources is at growing interest due to the limitations of chemical drugs in terms of side effects and cost-effective factors of natural medicines. Among the various components contained in natural plant materials, flavonoids are of increasing interest because of their extended biological benefits. Flavonoids are classified into various types according to their structure and possess different activities depending on the structure. In this study, the flavonoids contained in Artemisia, native to Korea were examined and reviewed. HPLC chromatograms of three Artemisia species (Artemisia annua L., Artemisia iwayomogi and Artemisia argyi H.) were examined from published sources and their component analysis by MS data were summarized. The various flavonoids of Artemisia were classified into 12 types according to the main structure, and 10 flavonoids based on various activities were examined. The 10 flavonoids were identified as quercetin, kaempferol, rhamnetin, diosmetin, luteolin, methoxyflavone, catechin, apigenin, malvidin and genkwanin with extensive reported studies till date. The ten flavonoids examined have been reported to be effective in preventing and treating various diseases and exhibit activities such as anti-cancer, anti-inflammatory, antioxidant, antiviral, anti-obesity, anti-diabetic and anti-Alzheimer. The collective results from the reported studies suggest that the three types of Korean native Artemisia, contains various flavonoids with beneficial activities and may have therapeutic effects against diseases.