Succession of Genetic Diversity of Botryococcus braunii (Trebouxiophyceae) in Two Japanese Reservoirs

AbstractBotryococcus braunii is a green colonial alga that produces large volumes of liquid hydrocarbon. Therefore, B. braunii is expected to be useful as an alternative fuel resource. Natural blooms of B. braunii have been recorded in several lakes and reservoirs. Elucidation of natural B. braunii blooming would provide important information for the development of an open-pond cultivation system. In this study, we periodically assessed the genetic diversity and colony density of B. braunii populations, along with several environmental parameters, in two Japanese reservoirs (provisionally called “N” and “S”) from December 2008 to December 2009. Reservoir N had low numbers of B. braunii colonies whereas Reservoir S was characterized by periodic density increases that occurred in December 2008, and in March, September, and December 2009. Population genetics analysis using specific environmental sequences (PGA-SES method) was conducted for B. braunii populations for the first time. Among the B. braunii-dominated samples of Reservoir S, high levels of genetic diversity were observed in December 2008 and March 2009, whereas the diversity levels in September and December 2009 were low. The results suggest that B. braunii periodicity can be categorized into a high genetic diversity type and a low genetic diversity type. The high genetic diversity type may be caused by simultaneous growth of many genotypes, whereas the low genetic diversity type seems to be explained by increases in the cell density of only a few adapted genotypes

Characterization of the effect of ion irradiation on industrially produced GdBa₂Cu₃O₇−δ superconducting tapes using a slow positron beam

To investigate the effect of irradiation-induced defects on the superconducting characteristics of industrially produced superconductor—GdBa₂Cu₃O₇−δ (GdBCO)—coated conductors (CCs), we irradiated the GdBCO CCs with Au ions at 2 or 10 MeV and probed them using a slow positron beam. Vacancy clusters were detected in both unirradiated and irradiated GdBCO CCs. However, the effect of ion irradiation on the GdBCO CCs was characterized as a slight reduction in the positron annihilation rate with low-momentum electrons. We also found a correlation between the annihilation rate of low-momentum electrons and the superconducting transition temperature

Pore-size expansion of hexagonal-structured nanocrystalline titania/CTAB Nanoskeleton using cosolvent organic molecules

Pore-size expansion of hexagonal-structured assembly of nanocrystalline titania (anatase) combined with cetyltrimethyammonium bromide (CH(3)(CH(2))(15)N(+)(CH(3))(3)Br(-), CTAB) (named as Hex-ncTiO(2)/CTAB Nanoskeleton) was achieved with the aid of cosolvent organic molecules (COMs). The pore-size expanded Hex-ncTiO(2)/CTAB Nanoskeleton was prepared through the sot-gel reaction of titanium oxysulfate sulfuric acid hydrate (TiOSO(4)center dot xH(2)SO(4)center dot xH(2)O, TiOSAH) in an aqueous solution initiated by CAB swollen micelles pre-prepared with the addition of COMs into aqueous CTAB micellar solutions at 60 degrees C (the product was named as Hex-ncTiO(2)/CTAB/COM Nanoskeleton). Long-chain alcohol (1-hexadecanol. C16OH), normal alkane (n-decane, C10) and benzene derivatives (benzene. Bz; 1,3,5-trimethylbenzene, TMB; 1,3,5-triethylbenzene, TEB; 1,3,5-triisopropylbenzene, TiPB) were used as COMs to evaluate the effects of COM solubilization site in CTAB micelles and COM molecular size on the pore-size expansion of the Hex-ncTiO(2)/CTAB/COM Nanoskeleton. We found that 1,3,5-trimethylbenzene (TMB) and 1,3,5-triethylbenzene (TEB) act as effective COMs for pore-size expansion of the Hex-ncTiO(2)/CTAB/COM Nanoskeleton in aqueous media. Pore sizes (average diameters) of the Hex-ncTiO(2)/CTAB/TMB Nanoskeleton and Hex-ncTiO(2)/CTAB/TEB Nanoskeleton were enlarged up to 4.2 nm and 4.3 nm, respectively, while pore size (average diameter) of the Hex-ncTiO(2)/CTAB Nanoskeleton prepared in the absence of any COMs was 2.9 nm. We also revealed that thermal stability of the Hex-ncTiO(2)/CTAB/TMB Nanoskeleton became higher than that of Hex-ncTiO(2)/CTAB Nanoskeleton. The hexagonally pore-structure of the Hex-ncTiO(2)/CTAB/TMB Nanoskeleton was retained up to 400 degrees C, while the hexagonally pore-structure of the Hex-ncTiO(2)/CTAB Nanoskeleton was kept up to 300 degrees C.ArticleCOLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS. 371(1-3):29-39 (2010)journal articl

Rationale and design of assessment of lipophilic vs. hydrophilic statin therapy in acute myocardial infarction (the ALPS-AMI) study

SummaryBackgroundStatins reduce the incidence of cardiovascular events in patients with acute myocardial infarction (AMI). Although all statins are equally effective in secondary prevention, there might be certain differences in the effects of lipophilic and hydrophilic statins. Therefore, our aim is to compare the effectiveness of lipophilic atorvastatin and hydrophilic pravastatin in secondary prevention after AMI.Methods and resultsThis study is a prospective, randomized, open-label, multicenter study of 500 patients with AMI. Patients that have undergone successful percutaneous coronary intervention will be randomly allocated to receive either atorvastatin or pravastatin with the treatment goal of lowering their low-density lipoprotein-cholesterol level below 100mg/dl for 2 years. The primary endpoint will be death due to any cause, nonfatal MI, nonfatal stroke, unstable angina, or congestive heart failure requiring hospital admission, or any type of coronary revascularization.ConclusionThis is the first multicenter trial to compare the effects and safety of lipophilic and hydrophilic statin therapy in Japanese patients with AMI. It addresses an important issue and could influence the use of statin treatment in the secondary prevention of coronary artery disease

Responses of Picoplankton to Nutrient Perturbation in the South China Sea, with Special Reference to the Coast-wards Distribution of Prochlorococcus

地球上细胞最小、丰度最大的放氧光合自养原核生物原绿球藻 (Prochlorococcus)发现于热带大洋 ,并被证实可在某些近海甚至近岸水域大量分布。但除温度之外 ,原绿球藻自然分布的控制因子尚不明了。从近海和大洋生态条件的主要差别考虑 ,在南海进行了主要营养盐———氮、磷和微量元素———铁、钴扰动的现场培养实验 ,并应用流式细胞技术监测原绿球藻及聚球藻 (Synechococcus)、超微型真核浮游植物 (pico_eukaryotes)的细胞丰度和单细胞色素含量的响应以及细菌的影响。结果表明 ,磷和钴的添加有利于原绿球藻 ,而氮和铁的添加更有利于聚球藻和超微型真核浮游植物。同时 ,由环境条件引起的生物响应又间接地导致超微型生物之间的相互作用。因而 ,原绿球藻在近海的分布 ,可能受到营养盐组成等环境因子以及生物之间的相互作用等多方面的限制和影响Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico_eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen_ (N), phosphorus_ (P), iron_ (Fe), and cobalt_ (Co) enriched incubations in the South China Sea in November 1997. Variations in abundance of the 4 groups of microorganism and cellular pigment content of the autotrophs during incubation were followed by flow_cytometric measurements for seven days. During the incubation, Syn and Euk showed a relatively higher demand on Fe and N, while Pro required higher levels of Co and P. The Fe was inadequate for all the organisms in the deep euphotic zone (75 m) of the study area. The experimental results also implied that biological interaction among the organisms played a role in the community structure shift during the incubation. It seemed that besides the effects of temperature, there are some other physical and chemical limitations as well as impacts from biological interactions on Pro distribution in coast waters.国家自然科学基金 ( 396 2 5 0 0 8;49876 0 33) ;; 国家重大基础研究和发展规划项目 (G2 0 0 0 0 785 0 0 )~

Efficacy and Safety of Long-Term Thiopurine Maintenance Treatment in Japanese Patients With Ulcerative Colitis

Background/AimsThe long-term clinical outcomes of patients with bio-naive ulcerative colitis (UC) who maintain remission with thiopurine are unclear. The aim of this study was to assess the long-term efficacy and safety of maintenance treatment with thiopurine in UC patients.MethodsThis was a retrospective observational cohort analysis conducted at a single center. Between December 1998 and August 2013, 59 of 87 patients with bio-naive UC who achieved remission after induction with treatments other than biologics were enrolled. Remission maintenance with thiopurine was defined as no concomitant treatment needed other than 5-aminosalicylate without relapse. We assessed the remission-maintenance rate, mucosal healing rate, colectomy-free rate, and treatment safety in UC patients who received thiopurine as maintenance treatment.ResultsThe 84-month cumulative remission-maintenance and colectomy-free survival rates in the UC patients who were receiving maintenance treatment with thiopurine and 5-aminosalicylate were 43.9% and 88.0%, respectively. Of the 38 patients who underwent colonoscopy during thiopurine maintenance treatment, 23 (60.5%) achieved mucosal healing. Of the 59 patients who achieved clinical remission with thiopurine, 6 patients (10.2%) discontinued the thiopurine therapy because of adverse events.ConclusionsOur study demonstrates the long-term efficacy and safety of thiopurine treatment in patients with bio-naive UC

Ubiquitous organic molecule-based free-standing nanowires with ultra-high aspect ratios

ごくありふれた有機分子からナノ細線をつくり立たせて埋めつくす --立体電子回路や超高感度センサーへ--. 京都大学プレスリリース. 2021-06-30.The critical dimension of semiconductor devices is approaching the single-nm regime, and a variety of practical devices of this scale are targeted for production. Planar structures of nano-devices are still the center of fabrication techniques, which limit further integration of devices into a chip. Extension into 3D space is a promising strategy for future; however, the surface interaction in 3D nanospace make it hard to integrate nanostructures with ultrahigh aspect ratios. Here we report a unique technique using high-energy charged particles to produce free-standing 1D organic nanostructures with high aspect ratios over 100 and controlled number density. Along the straight trajectory of particles penetrating the films of various sublimable organic molecules, 1D nanowires were formed with approximately 10~15 nm thickness and controlled length. An all-dry process was developed to isolate the nanowires, and planar or coaxial heterojunction structures were built into the nanowires. Electrical and structural functions of the developed standing nanowire arrays were investigated, demonstrating the potential of the present ultrathin organic nanowire systems