Development of a 1,3a,6a-triazapentalene derivative as a compact and thiol-specific fluorescent labeling reagent

For the fluorescence imaging of biologically active small compounds, the development of compact fluorophores that do not perturb bioactivity is required. Here we report a compact derivative of fluorescent 1,3a,6a-triazapentalenes, 2-isobutenylcarbonyl-1,3a,6a-triazapentalene (TAP-VK1), as a fluorescent labeling reagent. The reaction of TAP-VK1 with various aliphatic thiols proceeds smoothly to afford the corresponding 1,4-adducts in high yields, and nucleophiles other than thiols do not react. After the addition of thiol groups in dichloromethane, the emission maximum of TAP-VK1 shifts to a shorter wavelength and the fluorescence intensity is substantially increased. The utility of TAP-VK1 as a compact fluorescent labeling reagent is clearly demonstrated by the labeling of Captopril, which is a small molecular drug for hypertension. The successful imaging of Captopril, one of the most compact drugs, in this study demonstrates the usefulness of compact fluorophores for mechanistic studies

Keynote Talk – Novel convective heat transfer enhancement in channels and tubes filled with nanofluid-saturated metal foams

A local thermal non-equilibrium theory was exploited to investigate heat transfer in nanofluid saturated porous media, in view of possible heat transfer applications of metal foams filled with nanofluids as high performance heat exchangers. The resulting set of the macroscopic equations based on the modified Buongiorno model proposed by Yan et al. for convective heat transfer in nanofluids were used to obtain the analytical solutions for laminar fully developed forced convection in channels and tubes filled with nanofluid saturated metal foams. The analytical and numerical solutions were obtained for laminar fully developed forced convection in channels and tubes filled with nanofluid saturated metal foams. These solutions reveal that combination of the metal foams and nanofluids is quite effective to attain unconventionally high heat transfer performance, namely, 80 to 100 times more than the case of base fluid convection without a metal foam and thus can be used for next generation high performance heat exchangers

An innovative culture technique for microalgae using hollow fiber membranes

A hollow fiber culture system has been proposed for supplying the carbon dioxide to the microalgae, to replace the conventional air bubbling system which has been adopted to supply carbon dioxide in most conventional microalgal culture. In order to examine the usefulness of hollow fiber membranes for the microalgal culture, the microalgal growth rate for Chlorella sp. and the effective mass transfer coefficient of carbon dioxide through the hollow fiber membranes have been measured using the proposed photobioreactor filled with hollow fibers. The microalgal growth rate using hollow fiber membranes was found to be three times greater than that observed in the conventional non-membrane photobioreactor. Please download the full abstract below

Applications of the Volume Averaging Theory to Momentum and Heat Transfer within Complex Flow Systems

The volume averaging theory (VAT) developed in the study of porous media is quite powerful in attacking difficult problems associate with momentum and heat transfer in complex fluid flow system, such as heat exchangers, combustors and engine nacelles. Applications of VAT to momentum and heat transfer within complex heat and flow systems are reviewed in this lecture. Such difficulties arise from geometrical complexities and conjugate heat transfer between fluids and solids. In order to overcome the difficulties, the set of the governing equations are integrated over a local control volume to obtain the macroscopic governing equations. The sub-scale (i.e. pore-scale) modeling is carried out to close the set of the equations. Subsequently, the unknown model constants are determined by conducting direct numerical simulations using a structural unit model. Various applications in heat exchangers, composting systems and human bodies are discussed to elucidate the validity of the present procedure

Basal Cell Carcinoma of the Head and Neck

Basal cell carcinoma (BCC) is a malignant neoplasm derived from nonkeratinizing cells that originate from the basal layer of the epidermis and is the most frequent type of skin cancer in humans, with cumulative exposure to ultraviolet radiation as an important risk factor. BCC occurs most frequently at sun-exposed sites, with the head and neck being common areas. Tumors can be classified as nodular, superficial, morpheaform, infiltrating, metatypic, and fibroepithelioma of Pinkus. Several treatment options such as surgical excision and nonsurgical procedures are available. The choice of treatment should be determined based on the histological subtype of a lesion, cost, its size and location, patient age, medical condition of the patient, treatment availability, and the patient's wishes. The aim of any therapy selected for BCC treatment involving the head and neck is to ensure complete removal, the preservation of function, and a good cosmetic outcome

Total synthesis of palau’amine

Palau’amine has received a great deal of attention in the past two decades as an attractive synthetic target by virtue of its intriguing molecular architecture and significant immunosuppressive activity. Here we report the total synthesis of palau’amine characterized by the construction of an ABDE tetracyclic ring core including a trans-bicylo[3.3.0]octane skeleton at a middle stage of total synthesis. The ABDE tetracyclic ring core is constructed by a cascade reaction of a cleavage of the N–N bond, including simultaneous formation of imine, the addition of amide anion to the resulting imine (D-ring formation) and the condensation of pyrrole with methyl ester (B-ring formation) in a single step. The synthetic palau’amine is confirmed to exhibit excellent immunosuppressive activity. The present synthetic route has the potential to help elucidate a pharmacophore as well as the mechanistic details of immunosuppressive activity