Flow Resistance and Heat Transfer Characteristics of Water Solution Flow with Surfactant in Circular Tubes

The reduction characteristics of flow resistance and heat transfer of water solution flow with the surfactant (Cetyltrimethyl-ammonium Bromide) in tubes were investigated experimentally. The flow resistance and heat transfer of Water solution flow with the surfactant were markedly reduced as compared with those of pure water flow. Useful nondimensional correlative equations of flow resistance and heat transfer were derived in terms of various non-dimensional parameters.近年、熱エネルギーの効率的な管内輸送手段として、温冷水にある種の鎖状高分子や界面活性剤を添加し、その管内圧力損失の低減効果（トムズ効果）を利用する試みが注目されている。トムズ効果は、数～数十ppm程度の鎖状高分子や界面活性剤を水に添加することにより、管内流動抵抗軽減効果を意味し、管内輸送において、摩擦損失の減少による流量増加やポンプ動力の減少が期待できる。このトムズ効果のメカニズムは、添加した鎖状高分子が糸巻き状（ランダムコイル状）となって流体中に混合し、そのランダムコイルが乱流渦の発生や発達を抑止することとされている。一方、ある種の界面活性剤は、その添加濃度を増大すると棒状のミセル構造を形成し、鎖状高分子のランダムコイルと同じ働きをすると言われている。トムズ効果を期待できる界面活性剤として、カチオン系界面活性剤である臭化セチルトリメチルアンモニウム（略して、CTAB：分子量364.46、図1参照）を添加した水溶液の場合には、高分子系のものと比較して、せん断力による劣化が少なく、循環系への利用に適していると考えられる。しかしながら、（CTAB）水溶液のような界面活性剤を添加した場合には、トムズ効果が有効に作用するには、ミセル構造の形成に関係する温度範囲が存在し、その使用条件が限られる。また、一般に非ニュートン流体であるため、その特性の解明には困難さを伴うものである。本研究は、高分子水溶液としてポリエチレングリコール（略して、PEG：平均分子量約200万）、そして界面活性剤水溶液としてCTABを使用し、両水溶液の粘性特性を明らかにした後、PEG水溶液のの管摩擦係数や熱伝達率に影響を及ぼす諸因子の効果を実測し、この種の界面活性剤の流動抵抗軽減および熱伝達特性を解明するものである

Mycalolide-B, a novel and specific inhibitor of actomyosin ATPase isolated from marine sponge

AbstractA toxin isolated from marine sponge, mycalolide-B, inhibited smooth muscle contractions without changing cytosolic Ca2+ levels. It also inhibited Ca2+-induced contraction in permeabilized smooth muscles. In native actomyosin prepared from chicken gizzard, mycalolide-B inhibited superprecipitation and Mg2+-ATPase activity stimulated by Ca2+ without changing myosin light chain phosphorylation. In the permeabilized muscle and native actomyosin preparation thiophosphorylated with ATPγS, mycalolide-B inhibited ATP-induced contraction and Mg2+-ATPase activity, respectively, in the absence of Ca2+. Mycalolide-B also inhibited Mg2+-ATPase activity of skeletal muscle native actomyosin. Mycalolide-B had no effect on calmodulin-stimulated (Ca2+Mg2+)-ATPase activity of erythrocyte membranes. These results suggest that mycalolide-B selectively inhibits actin—myosin interaction

Long-Term Follow-Up of Autoimmune Pancreatitis: Characteristics of Chronic Disease and Recurrence

Autoimmune pancreatitis is a unique disease, characterized by lymphoplasmacytic inflammation in the acute stages. However, the active clinical features are unlikely to persist for long periods. Through long-term follow-up, we investigated the disease course in 51 patients with autoimmune pancreatitis. We found recurrence in 21 (41%) patients and pancreatic stone formation in 9 (18%) patients. Pancreatic stone formation was significantly more frequent in the recurrence group (7/21, 33%), compared with the nonrecurrence group (2/30, 7%). Moreover, we found high serum immunoglobulin G4 concentrations in 13 of 175 (7.4%) patients with ordinary chronic pancreatitis. This suggested that pancreatic stone formation is closely associated with recurrence and that autoimmune pancreatitis might transform into ordinary chronic pancreatitis after several recurrences. We found that the immune complex level, with a cutoff value of 10 mu g/dL, served as a good predictor of recurrence, with high sensitivity (61.9%), specificity (70.0%), and efficacy (66.7%). We also confirmed that HLA and cytotoxic T-lymphocyte antigen-4 polymorphisms were useful predictors for AIP recurrence.ArticleCLINICAL GASTROENTEROLOGY AND HEPATOLOGYjournal articl

The adenosine A2A receptor is associated with methamphetamine dependence/psychosis in the Japanese population

<p>Abstract</p> <p>Background</p> <p>Several lines of evidence suggest that the dopaminergic nervous system contributes to methamphetamine (METH) dependence, and there is increasing evidence of antagonistic interactions between dopamine and adenosine receptors. We therefore hypothesized that variations in the A2A adenosine receptor (<it>ADORA2A</it>) gene modify genetic susceptibility to METH dependence/psychosis.</p> <p>Methods</p> <p>We first analyzed variations in the exons and exon-intron boundaries of the <it>ADORA2A </it>gene in METH dependent/psychotic patients. Then an association analysis between these single nucleotide polymorphisms and METH dependence/psychosis was performed using a total of 171 METH dependent/psychotic patients and 229 controls.</p> <p>Results</p> <p>We found 6 variations, of which one single nucleotide polymorphism (SNP) was novel. Significant associations were observed between the allelic and genotypic frequencies of the Exon2+751 (rs5751876) SNP and METH dependence/psychosis. These associations were observed especially in females. In the clinical feature analyses, significant associations were observed between the SNP and the patient subgroup using METH alone (i.e., without concomitant use of other substances of abuse).</p> <p>Conclusions</p> <p>These results suggest that the <it>ADORA2A </it>gene could be a vulnerability factor for METH dependence/psychosis, especially in females and/or in patients using only METH.</p

A Novel Immunoglobulin-Immunoglobulin Interaction in Autoimmunity

Well over six decades since its first description, the Rheumatoid Factor (RF)—autoantibodies recognizing Fc (constant) portion of IgG through their own Fab (antigen binding variable segments)—is believed to have come of age. Autoimmune pancreatitis is a unique form of pancreatitis, biologically characterized by an elevated serum IgG4 concentration. Given the fact that IgG4 myeloma proteins can act as RF, we initially hypothesized that IgG4 in autoimmune pancreatitis might do likewise, hence potentially contributing to disease pathogenesis. Indeed Western blotting clearly showed that IgG4 binds to IgG1 κ, IgG2 κ, IgG3 κ myeloma proteins, as well as to IgG Fc, in line with a typical RF activity. Further experiments however unraveled the unexpected fact that unlike hitherto known RF, IgG4 does not engage IgG Fc through its Fab, but its very own Fc. These data therefore collectively describe a Novel RF (NRF) in autoimmune pancreatitis. In the future, the relevance of NRF, beyond autoimmune pancreatitis, in both diagnosis/prognosis as well as pathophysiology of autoimmune and other systemic diseases where IgG4's role seems paramount, needs to be systematically assessed

Risk factors for pancreatic stone formation in autoimmune pancreatitis over a long-term course

Autoimmune pancreatitis (AIP) has the potential to progress to a chronic state that forms pancreatic stones. The aim of this study was to clarify the risk factors underlying pancreatic stone formation in AIP. Sixty-nine patients with AIP who had been followed for at least 3 years were enrolled for evaluation of clinical and laboratory factors as well as computed tomography and endoscopic retrograde cholangiopancreatography findings. During the course of this study, increased or de novo stone formation was seen in 28 patients, who were defined as the stone-forming group. No stones were observed in 32 patients, who were defined as the non-stone-forming group. Nine patients who had stones at diagnosis but showed no change during the course of this study were excluded from our cohort. Univariate analysis revealed no significant differences in clinical or laboratory factors associated with AIP-specific inflammation between the two groups. However, pancreatic head swelling (P = 0.006) and narrowing of both Wirsung's and Santorini's ducts in the pancreatic head region (P = 0.010) were significantly more frequent in the stone-forming group. Furthermore, multivariate analysis identified Wirsung and Santorini duct narrowing at diagnosis as a significant independent risk factor for pancreatic stone formation (OR 4.4, P = 0.019). A primary risk factor for pancreatic stone formation in AIP was narrowing of both Wirsung's and Santorini's ducts, which most presumably led to pancreatic juice stasis and stone development.ArticleJOURNAL OF GASTROENTEROLOGY. 47(5):553-560 (2012)journal articl

Development and Performance of Kyoto's X-ray Astronomical SOI pixel (SOIPIX) sensor

We have been developing monolithic active pixel sensors, known as Kyoto's X-ray SOIPIXs, based on the CMOS SOI (silicon-on-insulator) technology for next-generation X-ray astronomy satellites. The event trigger output function implemented in each pixel offers microsecond time resolution and enables reduction of the non-X-ray background that dominates the high X-ray energy band above 5--10 keV. A fully depleted SOI with a thick depletion layer and back illumination offers wide band coverage of 0.3--40 keV. Here, we report recent progress in the X-ray SOIPIX development. In this study, we achieved an energy resolution of 300~eV (FWHM) at 6~keV and a read-out noise of 33~e- (rms) in the frame readout mode, which allows us to clearly resolve Mn-K$\alpha$ and K$\beta$. Moreover, we produced a fully depleted layer with a thickness of $500~{\rm \mu m}$. The event-driven readout mode has already been successfully demonstrated.Comment: 7pages, 12figures, SPIE Astronomical Telescopes and Instrumentation 2014, Montreal, Quebec, Canada. appears as Proc. SPIE 9147, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ra

Association Analysis of the Tryptophan Hydroxylase 2 Gene Polymorphisms in Patients with Methamphetamine Dependence/Psychosis

There is a growing evidence that serotoninergic systems modulate dopaminergic neurotransmission. We analyzed the association between the variations in the brain tryptophan hydroxylase 2 (TPH2) gene, a rate limiting enzyme for serotonin biosynthesis, and methamphetamine (METH) dependence/psychosis in a Japanese population. We found ten single nucleotide polymorphisms (SNPs) and two polynucleotide polymorphisms in TPH2 gene exons and exon-intron boundaries. A total of 162 patients and 243 controls were used for the association analysis between these polymorphisms and METH dependence/psychosis. No significant differences were observed in either genotypic or allelic frequencies between METH dependent/psychotic patients and controls. A global test of differentiation among samples based on haplotype frequencies showed no significant association. With respect to latency of psychosis, prognosis of psychosis, and spontaneous relapse, we found no significant association with these SNPs. These results suggest that the TPH2 gene variants may not be a factor in vulnerability to METH dependence/psychosis