Orders of magnitude loss reduction in photonic bandgap fibers by engineering the core surround.

We demonstrate how to reduce the loss in photonic bandgap fibers by orders of magnitude by varying the radius of the corner strands in the core surround. As a fundamental working principle we find that changing the corner strand radius can lead to backscattering of light into the fiber core. Selecting an optimal corner strand radius can thus reduce the loss of the fundamental core mode in a specific wavelength range by almost two orders of magnitude when compared to an unmodified cladding structure. Using the optimal corner radius for each transmission window, we observe the low-loss behavior for the first and second bandgaps, with the losses in the second bandgap being even lower than that of the first one. Our approach of reducing the confinement loss is conceptually applicable to all kinds of photonic bandgap fibers including hollow core and all-glass fibers as well as on-chip light cages. Therefore, our concept paves the way to low-loss light guidance in such systems with substantially reduced fabrication complexity.

Vastus intermedius vs vastus lateralis fascicle behaviors during maximal concentric and eccentric contractions.

Vastus intermedius (VI) plays a major role in knee extension, but its fascicle behaviors during dynamic contractions are not well understood. This study aimed to compare VI and vastus lateralis (VL) fascicle behaviors during singular maximal concentric and eccentric contractions. Thirteen men (27.1 ± 3.4 years) performed maximal isokinetic concentric contractions through knee joint angles of 105° to 35° (0° = full extension) and eccentric contractions from 35° to 105° at an angular velocity of 30°/s. Longitudinal VI and VL sonographic images were simultaneously recorded at 30 Hz, and muscle fascicle lengths at the knee joint angles of 40° and 100° were measured to compare the magnitudes of fascicle length change between the muscles. During concentric contractions, VI and VL fascicle lengths at 100° were 108 ± 12 mm and 104 ± 12 mm, respectively, and shortened by 36 ± 12 mm for VI and 28 ± 13 mm for VL (not statistically different; P = .13) at 40°. During eccentric contractions, VI and VL fascicle lengths at 40° were 72 ± 7 mm and 75 ± 8 mm, respectively, but lengthened by 35 ± 9 mm for VI and 24 ± 5 mm for VL at 100°, with a significant difference between the muscles (P = .01). These results indicate that VI fascicles are lengthened 1.4 times more than VL fascicles during eccentric contractions, whereas VI and VL fascicles shorten similarly during concentric contractions. This suggests a possibility that a greater mechanical strain is imposed to VI than VL during eccentric contractions.

Can the tricyanomethanide anion improve CO2 absorption by acetate-based ionic liquids?

Carbon dioxide absorption by mixtures of two ionic liquids with a common cation-1-butyl-3-methylimidazolium acetate, [C4C1Im][OAc], and 1-butyl-3-methylimidazolium tricyanomethanide, [C4C1Im][C(CN)3]-was determined experimentally at pressures below atmospheric pressure as a function of temperature between 303 K and 343 K, and at 303 K as a function of pressure up to 10 bar. It is observed that the absorption of carbon dioxide decreases with increasing tricyanomethanide anion concentration and with increasing temperature, showing a maximum of 0.4 mole fraction of carbon dioxide in pure [C4C1Im][OAc] at 303 K. At this temperature, the CO2 absorption in the mixtures [C4C1Im][OAc](1-x)[C(CN)3]x is approximately the mole-fraction average of that in the pure ionic liquids. By applying an appropriate thermodynamic treatment, after identification of the species in solution, it was possible to calculate both the equilibrium constant, Keq, and Henry's law constant, KH, in the different mixtures studied thus obtaining an insight into the relative contribution of chemical and physical absorption of the gas. It is shown that chemical sorption proceeds through a 1 : 2 stoichiometry between CO2 and acetate-based ionic liquid. The presence of the C(CN)3- anion does not significantly affect the chemical reaction of the gas with the solvent (Keq = 75 ± 2 at 303 K) but leads to lower Henry's law constants (from KH = 77.8 ± 0.6 bar to KH = 49.5 ± 0.5 bar at 303 K), thus pointing towards larger physical absorption of the gas. The tricyanomethanide anion considerably improves the mass transfer by increasing the fluidity of the absorbent as proven by the larger diffusivities of all the ions when the concentration of the C(CN)3- anion increases in the mixtures.

Tailoring the properties of acetate-based ionic liquids using the tricyanomethanide anion.

The equilibrium and transport properties of mixtures of two ionic liquids - [C4C1Im][OAc] and [C4C1Im][C(CN)3] - were determined and interpreted at the molecular level using vibration spectroscopy, NMR and molecular dynamics simulation. The non-ideality of the mixtures [C4C1Im][OAc](1-x)[C(CN)3]x was characterized by V(E) = +0.28 cm(3) mol(-1) (293 K, x = 0.65) and H(E) = -2.2 kJ mol(-1) for x = 0.5. These values could be explained by a rearrangement of the hydrogen-bond network of the mixture that favours the interaction of the acetate anion with the imidazolium cation at position C2. The dynamic properties of the mixture are also dramatically influenced by the composition with a decrease of the viscosity and an increase of self-diffusion coefficients of the ions when the amount of tricyanomethanide anion increases in the mixture.

Schizophrenia-like phenotypes in mice with NMDA receptor ablation in intralaminar thalamic nucleus cells and gene therapy-based reversal in adults.

In understanding the mechanism of schizophrenia pathogenesis, a significant finding is that drug abuse of phencyclidine or its analog ketamine causes symptoms similar to schizophrenia. Such drug effects are triggered even by administration at post-adolescent stages. Both drugs are N-methyl-d-aspartate receptor (NMDAR) antagonists, leading to a major hypothesis that glutamate hypofunction underlies schizophrenia pathogenesis. The precise region that depends on NMDAR function, however, is unclear. Here, we developed a mouse strain in which NMDARs in the intralaminar thalamic nuclei (ILN) were selectively disrupted. The mutant mice exhibited various schizophrenia-like phenotypes, including deficits in working memory, long-term spatial memory, and attention, as well as impulsivity, impaired prepulse inhibition, hyperlocomotion and hyperarousal. The electroencephalography analysis revealed that the mutant mice had a significantly reduced power in a wide range of frequencies including the alpha, beta and gamma bands, both during wake and rapid eye movement (REM) sleep, and a modest decrease of gamma power during non-REM sleep. Notably, restoring NMDARs in the adult ILN rescued some of the behavioral abnormalities. These findings suggest that NMDAR dysfunction in the ILN contributes to the pathophysiology of schizophrenia-related disorders. Furthermore, the reversal of inherent schizophrenia-like phenotypes in the adult mutant mice supports that ILN is a potential target site for a therapeutic strategy.

Increase of galanin in trigeminal ganglion during tooth movement.

It is known that nerve fibers containing neuropeptides such as galanin increase in the periodontal ligament during experimental tooth movement. However, the origin of galanin-containing nerve fibers in the periodontal ligament remains unclear. This study was conducted to examine our hypothesis that the increased galanin nerve fibers have a sensory neuronal origin, and that the peptide is associated with pain transmission and/or periodontal ligament remodeling during experimental tooth movement. In control rats, galanin-immunoreactive trigeminal ganglion cells were very rare and were observed predominantly in small ganglion cells. After 3 days of experimental tooth movement, galanin-immunoreactive trigeminal ganglion cells significantly increased, and the most marked increase was observed at 5 days after experimental tooth movement. Furthermore, their cell size spectrum also significantly changed after 3 and 5 days of movement: Medium-sized and large trigeminal ganglion cells began expressing, and continued to express, galanin until 14 days after experimental tooth movement. These findings suggest that the increase of galanin in the periodontal ligament during experimental tooth movement at least partially originates from trigeminal ganglion neurons and may play a role in pain transmission and/or periodontal remodeling.

Ethos in Fukushima and the ICRP dialogue seminars.

Ethos in Fukushima, a non-profit organisation, participated in 10 of the 12 International Commission on Radiological Protection (ICRP) dialogue seminars over the past 4 years. The slides and videos that were shown at the seminars are recorded on the Ethos in Fukushima website ( http://ethos-fukushima.blogspot.jp/p/icrp-dialogue.html ). I would like to introduce the activities of Ethos in Fukushima to date, and explain why the ICRP dialogue materials have come to be published on its website.

Measuring, discussing, and living together: lessons from 4 years in Suetsugi.

Cooperating with radiological protection experts and taking radiation measurements, the residents of Suetsugi, Iwaki City, Fukushima have been striving to reshape their lives since the accident at Fukushima Daiichi nuclear power plant. Suetsugi lies within 30 km of the power plant, so the residents have had serious reservations about continuing their lives there since the accident. Today, radiation remains a 'line' dividing their lives, with any dose measurements directly affecting their daily decision making. Assisted by medical and scientific specialists, the residents faced this challenging situation by measuring exposures individually and then discussing the results among themselves. Since 2012, the residents of Suetsugi have been using personal dosimeters, made village-wide trips for whole-body counter tests, and measured food contamination throughout the village. The results have been shared openly between the residents. Obtaining and discussing their own data were crucial to gain understanding of various results and to practice radiological protection in their daily routine. These 4 y of experience in Suetsugi demonstrate cooperation between various stakeholders, which should be a lesson for the future.

Reclaiming Our Lives in the Wake of a Nuclear Plant Accident.

Ryoko Ando lives and works in Iwaki-shi, which is located in the coastal area of Fukushima Prefecture. On 11 March 2011, Iwaki was hit by the Great East Japan Earthquake and tsunami. Then the nuclear plant accident at Fukushima No. 1 nuclear power plant, also located in the coastal area of Fukushima Prefecture, added to the woes of Iwaki residents. Although Iwaki-shi is outside of the 'restricted area' set up by the government in the 20 km radius around the nuclear power plant, some municipalities in Iwaki-shi lie within the 30 km radius zone. The residents of Iwaki were naturally concerned about the effects of radioactive contamination. On top of these, they had to confront a wide range of issues, including confusion and miscommunication, reputation risk and infrastructural constraints due to the influx of residents from the 'restricted area'.

Do teas rich in antioxidants reduce the physicochemical and peroxidative risk factors for calcium oxalate nephrolithiasis in humans? Pilot studies with Rooibos herbal tea and Japanese green tea.

Several experimental and animal studies have demonstrated that substances rich in antioxidants can reduce the physicochemical and peroxidative risk factors for calcium oxalate (CaOx) renal stone formation in urine and blood. However, there are very few such investigations in humans. In the present pilot study, two varieties of tea, a green one from Japan (JGT) and a herbal one from South Africa (Rooibos) (RT), both rich in antioxidants, were administered to a group of CaOx stone formers (SF) (n = 8) for 30 days. Both teas were analysed for polyphenols by high-performance liquid chromatography and for minerals by plasma atomic and optical emission spectroscopy. 24 h urines (baseline and day 30) were analysed for lithogenic factors. CaOx metastable limits and crystal nucleation and growth kinetics were also determined in each urine sample. Deposited crystals were inspected by scanning electron microscopy. Blood samples were collected (baseline and day 30). Biomarkers of oxidative stress including plasma and urinary thiobarbituric acid reactive substances (TBARS) and urinary N-acetyl-ß-D-glucosaminidase (NAG) were also determined. Urinary physicochemical risk factors were also investigated after ingestion of RT for 30 days in two control groups (CG1 and CG2), the latter one of which consisted of habitual JGT drinkers. Statistical analyses were performed using Wilcoxon signed rank tests and Mann-Whitney tests for paired and independent measurements, respectively. Several flavonoids and catechins were quantified in RT and JGT, respectively, confirming that both teas are rich sources of antioxidants. Mineral content was found to be far below dietary reference intakes. There were no significant changes in any of the urinary physicochemical or peroxidative risk factors in the control groups or in SF, except for the supersaturation (SS) of brushite (Bru) which decreased in the latter group after ingestion of JGT. Crystal morphology showed a tendency to change from mixed CaOx mono- and di-hydrate to monohydrate after ingestion of each tea. Since the latter form has a stronger binding affinity for epithelial cells, this effect is not protective. Analysis of the physicochemical and peroxidative risk factors in CG1 and CG2 did not reveal any evidence of a synergistic effect between the two teas. Paradoxically, baseline risk factors in the habitual JGT control group were significantly raised relative to those in CG1. Our preliminary results suggest that ingestion of RT and JGT does not reduce the risk factors for CaOx stone formation in humans, but these findings need to be tested in further studies involving much larger sample sizes.

Single-stranded DNA binding properties of the UvsX recombinase of bacteriophage T4: binding parameters and effects of nucleotides.

Bacteriophage T4 provides an important model for the biochemistry and genetics of DNA metabolism. Phage-encoded proteins conduct all essential steps of T4 DNA replication, repair, and recombination. Central to these three processes is the T4 UvsX protein, a member of the filamentous, ATP-dependent class of general recombination enzymes typified by the Escherichia coli RecA protein. Like RecA, UvsX forms presynaptic filaments on single-stranded (ss) DNA, which are the obligatory nucleoprotein intermediates in recombination. Aspects of the T4 presynaptic filament are explored by quantitative characterization of the UvsX-ssDNA interaction using an etheno-derivitized single-stranded DNA molecule, epsilonDNA, whose fluorescence is enhanced by UvsX binding. Studies with this model lattice show that UvsX exhibits a moderate level of cooperativity (omega=100) when binding to epsilonDNA with a binding-site size (n) equal to four nucleotide residues. Salt-stability studies of this complex reveal that the non-hydrolyzable ATP analog, ATPgammaS, induces a high-affinity binding mode that is distinguishable from complexes formed with ADP or in the absence of a nucleotide cofactor. With this new information, both functional relationships between the UvsX and RecA recombinases, and implications for UvsX interactions with the other proteins of the T4 presynaptic filament (UvsY and gp32) may be further explored.

Plasma histamine, epinephrine, cortisol, and leukocyte beta-adrenergic receptors in nocturnal asthma.

Plasma histamine, cortisol, epinephrine, cyclic adenosine monophosphate (cAMP), and leukocyte beta-adrenergic receptors were measured in asthmatic patients with (n = 7) and without (n = 10) nocturnal asthma at 4 PM and 4 AM and compared with those of normal subjects (n = 10). A twofold higher plasma histamine concentration was observed at 4 AM compared with 4 PM in all groups, with no change in plasma cortisol, epinephrine, and cAMP concentrations. At 4 AM compared with 4 PM, only patients with nocturnal asthma had a significant 33% decrease (p less than 0.05) in mononuclear and polymorphonuclear leukocyte beta-adrenergic receptor density, with no difference in binding affinity in all three groups. Polymorphonuclear leukocytes from patients with nocturnal asthma had significantly impaired response to isoproterenol at 4 AM (17% +/- 7.3% SEM increase in cAMP; p less than 0.05) compared with those of patients without nocturnal asthma (69.4% +/- 13.7%) and normal (80.2% +/- 21.3%) subjects. A significant change in beta-adrenergic receptor density and function occurs at night in patients with nocturnal asthma.

Behavioural characterization of substance P-induced nociceptive response in mice.

Intrathecal injection of substance P produced a behavioural syndrome, consisting of reciproacal hindlimb scratching and biting or fore- and hind-licking. Pretreatment with either an analogue of substance P, (D-Pro2, D-Trp7,9)-substance P (DPDT-SP) or (D-Arg1, D-Pro2,4, D-Trp7,9, Leu11)-substance P, given intrathecally, reduced the response to substance P in a dose-dependent manner. The behaviour induced by substance P was also inhibited by intrathecal, intracerebroventricular (i.c.v.) or intraperitoneal (i.p.) injection of morphine. Intrathecal or subcutaneous injection of naloxone showed a biphasic effect on substance P response; the substance P-induced nociceptive response was increased by a small dose of naloxone, while it was inversely decreased by a large dose of naloxone. The results with analogues of substance P support the hypothesis that substance P, injected intrathecally, acts directly on substance P receptors in the spinal cord. The nociceptive response induced by substance P appears to be controlled by endogenous opioids in the spinal cord.

Intrathecal substance P analogue causes motor dysfunction in the rat.

(D-Pro2, Trp7,9)-substance P injected into the subarachnoid space produced a severe faccid extension of hindlimb in a dose-related manner in the rat. This motor dysfunction was neither reversed by naloxone, an opioid receptor antagonist nor by intrathecal SP. SP levels in the lumbar cord were markedly depleted in rats with hindlimb paralysis, though there was not significant changes in rats without paraplegia. These results suggest that DPDT-SP produces motor dysfunction which dose not appear to be mediated by opioid and SP receptors.

3-(Arylacetylamino)-N-methylbenzamides: a novel class of selective anti-Helicobacter pylori agents.

After chemical modification preceded by the random screening of our chemical library, a novel class of selective anti-Helicobacter pylori agents was generated. Consequently, the 3-(arylacetylamino)-N-methylbenzamides, which were quite easy to prepare, showed potent inhibitory activity against Helicobacter pylori but exhibited no inhibitory activity against other sorts of bacteria and fungi, e.g., Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Bacteroides fragilis, and Candida albicans. These compounds showed potent anti-H. pylori activity under acidic conditions, whereas amoxicillin and clarithromycin decreased activity. The 3-(3-arylpropionylamino)-N-methylbenzamides, 3-(aryloxyacetylamino)-N-methylbenzamides, and (3-methylcarbamoylphenyl)carbamic acid 1-arylmethyl esters also exhibited potent anti-H. pylori activity. Finally, we selected 7n (BAS-118) as a candidate compound for further evaluation.

Is the bone mass of hemodialysis patients genetically determined?

Polymorphism of the vitamin D receptor gene (VDR) has been linked to bone mineral density in twins, postmenopausal osteoporosis, and premenopausal woman. We examined the possibility that the bone mass in hemodialysis (HD) patients might be determined by VDR. The study consisted of 229 HD patients with a mean age of 53.3 years (range 21 to 83), who were dialyzed three times a week for an average of 8.65 (range 0.2 to 24) years. We determined their VDR using DNA of peripheral white blood cells by restriction enzyme BsmI and the polymerase chain reaction-restriction fragment length polymorphism method. Bone mineral content (BMC) was estimated at 1/3 of the radius using dual energy X-ray bone absorptiometry, and expressed in z-scores standardized by gender and age. Distributions of VDR in this hemodialysis population were BB (9.9%), Bb (13.1%), and bb (77.0%), showing no significant different from those in 105 healthy volunteers (BB, 7.6%; Bb, 13.3%; and bb, 79.0%). Multiple regression analysis revealed that gender, age, duration on HD, and serum osteocalcin are major determinants of BMC (r = 0.762, P < 0.001), while VDR and serum parathyroid hormone are not. In a subgroup with younger (< 65 years) patients dialyzed for less than 8.65 years, the z-score of BMC of patients with BB allele was less than those with Bb and bb allele (N = 77, P = 0.020). We conclude that vitamin D receptor polymorphism is not one of the main determinants of BMC of HD patients, though it might partially effect bone mass in a subgroup of younger HD patients with shorter HD histories. Further studies with longitudinal observation will be needed to confirm these possibilities.

Spinal actions of GR73632, a novel tachykinin NK1 receptor agonist.

Behavioral characterization of GR73632, a newly synthesized tachykinin NK1 receptor agonist, was examined in mice. Intrathecal (IT) injection of GR73632 in the spinal subarachnoid space of mice elicited a dose-dependent behavioral syndrome, consisting of scratching, biting and licking. The time course of the response to GR73632 was almost similar to that of substance P. GR73632 evoked much more licking and biting than did substance P, that in turn caused less scratching. GR73632 was approximately 200-fold more potent than substance P in inducing the characteristic behavioral response. The GR73632-induced behavioral response was inhibited by IT co-administration of CP-96,345, a non-peptide NK1 receptor antagonist, but not its inactive enantiomer CP-96,344. CP-96,345, co-injected IT with substance P, also inhibited the behavioral response to substance P. These results demonstrate that the scratching, biting and licking response induced by IT GR73632 may be mediated by the NK1 receptor in the spinal cord. These findings suggest that GR73632 may be useful as a tachykinin NK1 receptor agonist and also for evaluating spinal pharmacological activities of NK1 receptor antagonists.

Intracerebroventricular injection of exendin (5-39) increases food intake of layer-type chicks but not broiler chicks.

To clarify the involvement of endogenous glucagon-like peptide-1 (GLP-1) on feeding in chicks, we examined the central effect of GLP-1 antagonist, exendin (5-39) on food intake. Intracerebroventricular co-injection of exendin (5-39) with GLP-1 attenuated the anorexigenic effect of GLP-1 in layer-type chicks. Furthermore, exendin (5-39) enhanced food intake of layer-type chicks under ad libitum feeding. However, this effect was not observed in broiler chicks. Therefore, endogenous GLP-1 may be important in the regulation of feeding in layer-type chicks but not in broiler chicks.

Brain-derived mast cells could mediate histamine-induced inhibition of food intake in neonatal chicks.

In the present study, the effect of intracerebroventricular (i.c.v.) administration of histamine on food intake of neonatal chicks was examined over 2 h. Histamine (100, 200 or 400 nmol, respectively) was injected in the lateral ventricle of 2-day-old chicks, and cumulative food intakes were measured. i.c.v. injection of histamine significantly inhibited food intake in a dose-dependent manner. In addition, compound 48/80, which causes degranulation of mast cells and release of histamine, or thioperamide, which is an antagonist of the histamine H3 autoreceptor and increases histamine release from histaminergic nerve terminals, was injected i.c.v. to clarify whether mast cell- or neuron-derived histamine in the central nervous system of chicks is essential to the feeding inhibition. Central administration of compound 48/80 inhibited food intake with a dose-dependent manner, but thioperamide had no effect on feeding. An inhibitor of mast cell degranulation, sodium cromoglycate, somewhat attenuated food intake inhibited by compound 48/80. These results suggest that brain-derived mast cells could be a major source of histamine in the inhibition of food intake of neonatal chicks.

Immunohistochemical determination of rat spinal cord substance P, and antinociceptive effect during development of thiamine deficiency.

During 30 days of thiamine deficiency (TD) feeding, the rat antinociceptive effect (pain threshold) to noxious heat stimulation was significantly increased in proportion to the decrease substance P (SP) fluorescent intensity in the spinal cord. Only a single injection of thiamine HCl (0.5 mg/kg, s.c.) on the early treatment day during TD feeding effectively reversed the analgesic effect to the pair-fed control level. Whereas this reversal effect by thiamine treatment was not found if this treatment was done on the relatively late day. However, either treatment day, except muricide, complete disappearance of various animal behaviours induced by TD was found. These results indicate that, after certain degree of TD development, TD-induced behavioral effects might be reversible, but the afferent nerve fibers might be irreversibly damaged, probably by the similar mechanism as found for an excitotoxin(s) mediated injury in the certain brain region(s). The results also suggest a possibility that SP and an excitotoxin, glutamate, in the dorsal part of the spinal cord greatly contribute to the pain transmission induced by noxious heat stimulation.