Photochemical Mechanism of an Atypical Algal Phytochrome

Phytochromes are bilin‐containing photoreceptors that are typically sensitive to the red/far‐red region of the visible spectrum. Recently, phytochromes from certain eukaryotic algae have become attractive targets for optogenetic applications because of their unique ability to respond to multiple wavelengths of light. Herein, a combination of time‐resolved spectroscopy and structural approaches across picosecond to second timescales have been used to map photochemical mechanisms and structural changes in this atypical group of phytochromes. The photochemistry of an orange/far‐red light‐sensitive algal phytochrome from Dolihomastix tenuilepis has been investigated by using a combination of visible, IR and X‐ray scattering probes. The entire photocycle, correlated with accompanying structural changes in the cofactor/protein, are reported. This study identifies a complex photocycle for this atypical phytochrome. It also highlights a need to combine outcomes from a range of biophysical approaches to unravel complex photochemical and macromolecular processes in multi‐domain photoreceptor proteins that are the basis of biological light‐mediated signalling.     

Mechanical Reinforcement of Low‐Concentration Alginate Fibers by Microfluidic Embedding of Multiple Cores

This paper presents mechanically reinforced low‐concentration alginate fibers by embedding inner cores of high‐concentration alginate. 3D structures by stacking multiple polydimethylsiloxane (PDMS) layers allow the microfluidic formation and control of the isolated cores in the continuous flow. The alginate hydrogel fibers are simply spun, and the compartments, central core, surrounding cores, and outer shell layer are successfully verified. The results demonstrate the great potential for the development of complex fibrous materials, particularly for biological applications, which require specific morphology and composition of the fibers.     

Behavior of N-methylcarbamate pesticides during refinement processing of edible oils

The following N-methylcarbamate pesticides, aldicarb, aldicarb sulfoxide, aldicarb sulfone, oxamyl, methomyl, thiodicarb, propoxur, carbofuran, carbosulfan, benfuracarb, bendiocarb, carbaryl, fenobcarb and furathiocarb, were added to soybean oil, each at 5 mg/kg(5 ppm), followed by degumming, alkali refining, bleaching and deodorization for oil refinement. Residual pesticide content in each case was determined immediately after refining. DEGUMMING: Aldicarb, aldicarb sulfoxide, aldicarb sulfone, oxamyl, thiodicarb, carbosulfan, benfuracarb were each found to decrease by as much as 70% by H(3)PO(4) treatment, this being less than 26% noted for the other pesticides. With hot water treatment, the decrease in any one pesticide was less than 52%. ALKALI REFINING: The rate of decrease varied with the pesticide, ranging from 8% to 100%. 200%NaOH were effectively brought about pesticide removal, compared to 125%NaOH. BLEACHING: Aldicarb, aldicarb sulfoxide, aldicarb sulfone, oxamyl, methomyl, thiodicarb, carbosulfan, benfuracarb, bendiocarb and furathiocarb each decreased by more than 80% with activated clay containing activated charcoal. Carbaryl decreased remarkably by this clay. Pesticide removal in all cases was at less than 30%. DEODORIZATION: 40% Furathiocarb, 14% carbosulfan, 11% benfuracarb and 3% carbofuran could still be detected subsequent to deodorization at 260 degrees C while all other pesticide amounts were too small to permit quantitative detection. Degumming with H(3)PO(4) and bleaching with activated clay caused the conversion of carbosulfan and benfuracarb into carbofuran. Carbofuran and furathiocarb may thus possibly still remain in the oil following the above 4 refinement processes.     

Mechanical Behavior of Shape Memory Alloys Under Complex Loading Conditions of Stress, Strain, and Temperature

The transformation behavior of shape memory alloys is simulated for complex loadings of stress, strain, and temperature. Calculations are made by using the ??Accommodation Model?? which is a constitutive model for shape memory alloys considering the accommodation behavior of the transformation strain. Calculated results are given for the superelastic behavior, the shape memory effect, the transformation behavior under temperature change with stress or strain holding, the structural behavior of a shape memory wire with a bias spring, etc. The effect of the plastic strain on the transformation strain is also investigated.     

Variations in signal intensity with periodical temperature changes in vivo in rat brain: analysis using wide-field optical coherence tomography

In a previous study, we reported measurements of three-dimensional (3D) optical coherence tomography (OCT) images through a thinned skull by reducing temperatures from 28 °C to 18 °C in vivo in the rat brain to show negative correlation coefficients (CCs) between ratios of signal intensity (RSI) and temperature for applications to monitoring brain viability. In this study, using the same OCT system, we measured 3D OCT images of the rat brain by periodically changing tissue temperatures from 20 °C to 32 °C in vivo. In the evaluation of CCs among RSI, temperature, and heart rate, the largest number of periods was four, and the longest measurement time was 570 min. Averaged CCs between RSI and temperature, and between RSI and heart rate, were -0.42 to -0.50 and -0.48 to -0.64, respectively. RSI reversibly changed subsequent variations of temperatures and finally increased rapidly just before cardiac arrest. These results indicate that RSI could correspond to decreases in viability because of local ischemia and recovery.     

Nickel-free stainless steel avoids neointima formation following coronary stent implantation

SUS316L stainless steel and cobalt–chromium and platinum–chromium alloys are widely used platforms for coronary stents. These alloys also contain nickel (Ni), which reportedly induces allergic reactions in some subjects and is known to have various cellular effects. The effects of Ni on neointima formation after stent implantation remain unknown, however. We developed coronary stents made of Ni-free high-nitrogen austenitic stainless steel prepared using a N₂-gas pressurized electroslag remelting (P-ESR) process. Neointima formation and inflammatory responses following stent implantation in porcine coronary arteries were then compared between the Ni-free and SUS316L stainless steel stents. We found significantly less neointima formation and inflammation in arteries implanted with Ni-free stents, as compared to SUS316L stents. Notably, Ni²⁺ was eluted into the medium from SUS316L but not from Ni-free stainless steel. Mechanistically, Ni²⁺ increased levels of hypoxia inducible factor protein-1α (HIF-1α) and its target genes in cultured smooth muscle cells. HIF-1α and their target gene levels were also increased in the vascular wall at SUS316L stent sites but not at Ni-free stent sites. The Ni-free stainless steel coronary stent reduces neointima formation, in part by avoiding activation of inflammatory processes via the Ni-HIF pathway. The Ni-free-stainless steel stent is a promising new coronary stent platform.     

New integral experiments for large angle scattering cross section data benchmarking with DT neutron beam at JAEA/FNS

A new integral experiment with a deuteron–triton fusion (DT) neutron beam started in order to validate scattering cross section data. First the DT neutron beam was constructed with a collimator. The performance of the collimator system and the characteristics of the DT neutron beam were measured. Second a new integral experiment for type 316 stainless steel (SS316) was carried out with this DT neutron beam. The DT neutron beam of 3.5 cm in diameter was injected to the front surface center of an SS316 cylindrical assembly. Reaction rates of the ⁹³Nb(n,2n)^92mNb reaction in the assembly were measured with the activation foil method and were calculated with the Monte Carlo transport calculation code. The measurement points were located at three positions, on the center of the beam axis and at 15 cm and 30 cm apart from the axis. The ratio of calculation to experiment of the ⁹³Nb(n,2n)^92mNb reaction rate became smaller than 1 with the distance from the beam axis. Then, the dependency of each reaction rate on scattering angle was calculated. It was proved that at off-axis positions, where C/E is smaller than 1, 90° scattering contribute relatively larger than at on-axis positions and backward scattering made little contribution to the results in this experiment. The reasons of the discrepancy between the measured and calculated data will be investigated.     

Promotion of initial cell adhesion on trisuccinimidyl citrate-modified nickel-free high-nitrogen stainless steel

The surface of nickel-free high-nitrogen stainless steel (HNS) was modified with a citric acid-based cross-linker, trisuccinimidyl citrate (TSC), to promote initial cell adhesion in external skeletal fixation pins. The remaining active ester groups on TSC-immobilized HNS reacted with the amino groups of serum proteins. The immobilized serum proteins formed cell recognition sites to promote the initial cell adhesion immediately after cell seeding. The amount of fibronectin, which is a typical cell adhesion protein, immobilized on the TSC-immobilized HNS surface was threefold greater than on the original HNS after only 15 min. The fibroblastic cell culture experiments showed that the initial cell adhesion was significantly enhanced on the TSC-immobilized HNS compared with the original HNS at 3 h. Furthermore, the cell adhesion activity of the TSC-immobilized HNS continued to promote cell proliferation even at 7 days. Therefore, TSC-immobilized HNS may enable the rapid integration of soft tissues through its reaction with the patient’s serum proteins and extracellular proteins around the surgical site.     

Effects of refractory elements on the microstructure and creep behaviour of nickel-base cast superalloys strengthened with high volume fraction gamma-prime phase

Microstructural observations and creep measurements at elevated temperatures were carried out on nickel-base cast superalloys strengthened by 0.65 atomic fraction gamma-prime (y'J phase with varied concentrations of Ta, Wand Mo and with elements commonly used in practice. The variations in the amounts of the refractory elements considerably altered the morphologies and the quantities of carbides as well as γ and γ’ eutectics. The steady-state creep rate for these alloys was related to lattice mismatch between the γ and γ’ phases as well as to the aluminium concentration in the γ’ phase. The effect of the elements on creep rupture life was in the order W>Ta>Mo.