Thermodynamic characterization of variants of mesophilic cytochrome c and its thermophilic counterpart

Thermal stability was measured for variants of cytochrome c-551(PA c-551) from a mesophile, Pseudomonas aeruginosa, and a thermophiliccounterpart, Hydrogenobacter thermophilus cytochrome c-552 (HTc-552), by differential scanning calorimetry (DSC) at pH 3.6.The mutated residues in PA c-551, selected with reference tothe corresponding residues in HT c-552, were located in threespatially separated regions: region I, Phe7 to Ala/Val13 toMet; region II, Glu34 to Tyr/Phe43 to Tyr; and region III, Val78to Ile. The thermodynamic parameters determined indicated thatthe mutations in regions I and III caused enhanced stabilitythrough not only enthalpic but also entropic contributions,which reflected improved packing of the side chains. Meanwhile,the mutated region II made enthalpic contributions to the stabilitythrough electrostatic interactions. The obtained differencesin the Gibbs free energy changes of unfolding [     

Operation and management of the Fukashiba treatment plant.

Since the opening of the Fukashiba Treatment Plant in 1970, the number of industries and the amount of wastewater requiring treatment in the service area have been steadily increasing. In response to the recent economic downturn in Japan, these rates of increase have slowed, but are not decreasing. The pollution load in the wastewater from these industries has decreased and is now stable. Unlike the case of ordinary domestic sewage, the effects of the various types of substances contained in wastewaters delivered from the petrochemical complex to the treatment plant, for example, corrosion, are quite large. Measures to deal with corrosion problems, such as replacement or modification of the facilities, improvement of the efficiencies of facility operation and wastewater treatment, and improvement of measures against odours, are being implemented.     

Intraoperative delayed pneumothorax after subclavian vein catheterization

Intraoperative delayed pneumothorax occurred in five patients. It took several attempts to insert a subclavian vein catheter in four of the patients. The first chest X-ray films after the insertion of the catheter in the five patients were not indicative of pneumothorax. Pulse oximetry could detect the initial sign of pneumothorax prior to hemodynamic instability in three patients. In case of positive pressure ventilation and nitrous oxide administration for general anesthesia, this complication may be life threatening. It is necessary to take great care not to overlook intraoperative delayed pneumothorax in a patient with subclavian vein catheterization.     

Clinical evaluation of a new programmable syringe infusion pump

A new programmable syringe infusion pump, Auto Syringe Model AS 40 A, was evaluated for infusion of muscle relaxants, vasodilators and opioids in 4 surgical patients. Every drug mentioned above was easily adjusted according to surgical requirement in these patients. Auto Syringe Model AS40A is light and compact. Its major advantages lie in the mechanisms for delivery of a bolus dose and automated delivery of intermittent doses, automatic rate calculation, and the applicability to various sizes of syringes. Auto Syringe Model AS40A was found to be very useful for intravenous infusion of drugs.     

Nickel‐Catalyzed Borylation of Aryl and Benzyl 2‐Pyridyl Ethers: A Method for Converting a Robust ortho‐Directing Group

The nickel‐catalyzed borylation of aryl 2‐pyridyl ethers via the loss of a 2‐pyridyloxy group is described. This method allows a 2‐pyridyloxy group to be used as a convertible directing group in C−H bond functionalization reactions. The nickel catalyst can also borylate arylmethyl 2‐pyridyl ethers, in which the stereochemistry at the benzylic position is retained in the case of chiral secondary benzylic substrates.

     

Picosecond carrier dynamics induced by coupling of wavefunctions in a Si-nanodisk array fabricated by neutral beam etching using bio-nano-templates

The picosecond carrier dynamics in a closely packed Si-nanodisk (Si-ND) array with ultrathin potential barrier fabricated by neutral beam etching using bio-nano-templates was investigated by time-resolved photoluminescence (PL). The PL decay curves were analyzed as a function of photon energy by the global fitting method. We show three spectral components with different decay times, where the systematic energy differences of the spectral peaks are clarified: 2.03 eV for the fastest decaying component with a decay time τ = 40 ps, 2.02 eV for τ = 300 ps, and 2.00 eV for τ = 1.6 ns. These energy separations ranging from 10 to 30 meV among the emissive states can be attributed to the coupling of wavefunctions of carriers between neighboring NDs.     

HUB1, a novel Krüppel type zinc finger protein, represses the human T cell leukemia virus type I long terminal repeat-mediated expression

We have shown that human T-cell leukemia virus type I (HTLV-I) gene expression is negatively regulated by the U5 repressive element (U5RE) of its long terminal repeat (LTR). To isolate factors binding to U5RE, we screened a cDNA expression library by south-western blotting with a U5RE probe. Screening 2 x10(6) clones gave a positive clone with a 3.8 kb insert encoding a novel 671 residue polypeptide, named HTLV-I U5RE binding protein 1 (HUB1), with five zinc finger domains and a Krüppel-associated box like domain; HUB1 may be related to a repressor belonging to the Krüppel type zinc finger protein. A 4.0 kb mRNA for HUB1 is ubiquitously expressed among all human tissues tested. HUB1 recognizes the TCCACCCC sequence as a core motif and exerts a strong repressive effect on HTLV-I LTR-mediated expression. A new repressive domain, named HUB1 repressive (HUR) domain, was identified, rather than the Krüppel-associated box like domain. The N-terminal region upstream of HUR domain seemed to be also indispensable to the repression. Thus, we propose that HUB1 is a new type repressor and plays an important role in the HTLV-I U5-mediated repression.