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Find video protocols related to scientific articles indexed in Pubmed.
Breaking aggregation in a tetrathiafulvalene-fused zinc porphyrin by metal-ligand coordination to form a donor-acceptor hybrid for ultrafast charge separation and charge stabilization.
Dalton Trans
PUBLISHED: 11-11-2014
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A novel electron rich, tetrathiafulvalene fused zinc porphyrin, (TTF)4PZn, has been newly synthesized and characterized using spectral and electrochemical methods. In spite of the presence of eight t-butyl groups, (TTF)4PZn exhibited appreciable aggregation in solution. Scanning electron microscopic (SEM) imaging of the aggregates revealed their spherical particulate morphology. Attenuation of intermolecular aggregation was possible by metal-ligand coordination of a nitrogenous ligand. Further, using this strategy, a donor-acceptor hybrid was formed by coordinating imidazole functionalized fullerene as an electron acceptor. The occurrence of intrasupramolecular ultrafast photoinduced charge separation has been established using fluorescence and transient absorption spectroscopic techniques. The determined rate of charge separation, kCS, and rate of charge recombination, kCR were found to be 1.4 × 10(11) s(-1) and 2.5 × 10(6) s(-1), respectively. The lower kCR values indicate charge stabilization in the assembled donor-acceptor conjugate via an electron transfer-hole transfer mechanism.
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Single-incision multiport laparoendoscopic surgery using a short-type flexible endoscope and its usefulness in cholecystectomy.
Asian J Endosc Surg
PUBLISHED: 08-21-2014
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We previously demonstrated the advantages of a short-type flexible endoscope as a working scope in laparoscopic surgery through single-incision procedures in animal experiments. In this report, we examined the outcomes of laparoscopic surgery through a single incision using a flexible endoscope in a clinical setting. Specifically, we performed cholecystectomy using single-incision multiport laparoendoscopic (SIMPLE) surgery.
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Evidence for participation of GCS1 in fertilization of the starlet sea anemone Nematostella vectensis: implication of a common mechanism of sperm-egg fusion in plants and animals.
Biochem. Biophys. Res. Commun.
PUBLISHED: 08-09-2014
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It has been reported that GCS1 (Generative Cell Specific 1) is a transmembrane protein that is exclusively expressed in sperm cells and is essential for gamete fusion in flowering plants. The GCS1 gene is present not only in angiosperms but also in unicellular organisms and animals, implying the occurrence of a common or ancestral mechanism of GCS1-mediated gamete fusion. In order to elucidate the common mechanism, we investigated the role of GCS1 in animal fertilization using a sea anemone (Cnidaria), Nematostella vectensis. Although the existence of the GCS1 gene in N. vectensis has been reported, the expression of GCS1 in sperm and the role of GCS1 in fertilization are not known. In this study, we showed that the GCS1 gene is expressed in the testis and that GCS1 protein exists in sperm by in situ hybridization and proteomic analysis, respectively. Then we made four peptide antibodies against the N-terminal extracellular region of NvGCS1. These antibodies specifically reacted to NvGCS1 among sperm proteins on the basis of Western analysis and potently inhibited fertilization in a concentration-dependent manner. These results indicate that sperm GCS1 plays a pivotal role in fertilization, most probably in sperm-egg fusion, in a starlet sea anemone, suggesting a common gamete-fusion mechanism shared by eukaryotic organisms.
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T7 lytic phage-displayed peptide libraries: construction and diversity characterization.
Methods Mol. Biol.
PUBLISHED: 05-16-2014
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In this chapter, we describe the construction of T7 bacteriophage (phage)-displayed peptide libraries and the diversity analyses of random amino acid sequences obtained from the libraries. We used commercially available reagents, Novagen's T7Select system, to construct the libraries. Using a combination of biotinylated extension primer and streptavidin-coupled magnetic beads, we were able to prepare library DNA without applying gel purification, resulting in extremely high ligation efficiencies. Further, we describe the use of bioinformatics tools to characterize library diversity. Amino acid frequency and positional amino acid diversity and hydropathy are estimated using the REceptor LIgand Contacts website http://relic.bio.anl.gov. Peptide net charge analysis and peptide hydropathy analysis are conducted using the Genetics Computer Group Wisconsin Package computational tools. A comprehensive collection of the estimated number of recombinants and titers of T7 phage-displayed peptide libraries constructed in our lab is included.
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Hepatolithiasis: analysis of Japanese nationwide surveys over a period of 40 years.
J Hepatobiliary Pancreat Sci
PUBLISHED: 05-14-2014
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The aims of the present study are to clarify the changes in clinicopathologic features, diagnosis and treatment for hepatolithiasis, and propose an appropriate management strategy in Japan. The research group conducted nationwide surveys seven times in the past over a period of 40 years. Furthermore, a cohort was followed up in 2010. We analyzed the clinical features, diagnosis tools, treatment procedures, outcomes, and predictive factors for cholangiocarcinoma. Surgery was the primary method for hepatolithiasis up to 1998, and the frequency of its use has decreased since then. In 2011, 66.7% of hepatolithiasis patients were treated using nonsurgical approaches. In addition, endoscopic retrograde cholangiography (ERC) with stone extraction was the most frequently performed procedure (22.7%). However, the incidences of residual stone and recurrent stone after ERC with stone extraction were higher than those after percutaneous transhepatic cholangioscopic lithotomy and surgery. Bile duct stricture and dilatation during follow up were significant risk factors for stone recurrences. In the cohort study, stone removal only and age >65 years were significant factors for the development of cholangiocarcinoma. In patients without a history of cholangioenterostomy, left-lobe-type stones were a risk factor, and hepatectomy reduced the risk of the development of cholangiocarcinoma significantly. Nonsurgical treatment may be performed as the first-line treatment for hepatolithiasis. Surgery should be performed on patients who were treated incompletely after nonsurgical treatment. However, hepatectomy may be recommended for patients with left-lobe-type stones and without a history of cholangioenterostomy.
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Ultrahigh sensitivity endoscopic camera using a new CMOS image sensor : Providing with clear images under low illumination in addition to fluorescent images.
Surg Endosc
PUBLISHED: 05-03-2014
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We developed a new ultrahigh-sensitive CMOS camera using a specific sensor that has a wide range of spectral sensitivity characteristics. The objective of this study is to present our updated endoscopic technology that has successfully integrated two innovative functions; ultrasensitive imaging as well as advanced fluorescent viewing.
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Sex-specific posttranslational regulation of the gamete fusogen GCS1 in the isogamous volvocine alga Gonium pectorale.
Eukaryotic Cell
PUBLISHED: 03-14-2014
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Male and female, generally defined based on differences in gamete size and motility, likely have multiple independent origins, appearing to have evolved from isogamous organisms in various eukaryotic lineages. Recent studies of the gamete fusogen GCS1/HAP2 indicate that this protein is deeply conserved across eukaryotes, and its exclusive and/or functional expression generally resides in males or in male homologues. However, little is known regarding the conserved or primitive molecular traits of males and females within eukaryotes. Here, using morphologically indistinguishable isogametes of the colonial volvocine Gonium pectorale, we demonstrated that GCS1 is differently regulated between the sexes. G. pectorale GCS1 molecules in one sex (homologous to male) are transported from the gamete cytoplasm to the protruded fusion site, whereas those of the other sex (females) are quickly degraded within the cytoplasm upon gamete activation. This molecular trait difference might be conserved across various eukaryotic lineages and may represent male and female prototypes originating from a common eukaryotic ancestor.
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Tips on laparoscopic distal pancreatectomy.
J Hepatobiliary Pancreat Sci
PUBLISHED: 02-18-2014
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An increasing number of laparoscopic pancreatic procedures are currently carried out worldwide. Laparoscopic distal pancreatectomy (LDP) appears to be technically and oncologically promising in selected patients with benign tumors and low-grade malignancies of the pancreatic body/tail, and is now widely adopted. Here, we described our standard procedures of LDP and some tips on LDP. Recent important insights into some variations/options of LDP including spleen preservation, hand-assisted procedure, and single-incision surgery are also reviewed in this article.
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Surgical management of superficial non-ampullary duodenal tumors.
Dig Endosc
PUBLISHED: 01-29-2014
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We present our experiences with the so-called 'limited resections' such as transduodenal excision and local full-thickness resection for superficial non-ampullary duodenal tumors (SNADT). The optimal surgical management for SNADT is also discussed.
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Gamete attachment requires GEX2 for successful fertilization in Arabidopsis.
Curr. Biol.
PUBLISHED: 01-02-2014
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Fertilization requires recognition, attachment, and membrane fusion between gametes. In metazoans, rapidly evolving surface proteins contribute to gamete recognition and adhesion. Flowering plants evolved a double fertilization process wherein two immotile sperm cells are delivered to female gametes by the pollen tube, guided by elaborate communications between male and female reproductive organs. Once released, the sperm cells contact female gametes directly prior to gamete fusion. It remains unclear whether active gamete recognition and attachment mechanisms are required for double fertilization. Here, we provide functional characterization of Arabidopsis GAMETE EXPRESSED 2 (GEX2), which encodes a sperm-expressed protein of unknown function. GEX2 is localized to the sperm membrane and contains extracellular immunoglobulin-like domains, similar to gamete interaction factors in algae and mammals. Using a new in vivo assay, we demonstrate that GEX2 is required for gamete attachment, in the absence of which double fertilization is compromised. Ka/Ks analyses indicate relatively rapid evolution of GEX2, like other proteins involved in male and female interactions. We conclude that surface proteins involved in gamete attachment and recognition exist in plants with immotile gametes, similar to algae and metazoans. This conservation broadens the repertoire of research for plant reproduction factors to mechanisms demonstrated in animals.
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Modified Glasgow prognostic score in patients with incurable stage IV colorectal cancer.
Am. J. Surg.
PUBLISHED: 07-01-2013
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The modified Glasgow prognostic score is an inflammation-based prognostic score. This study examined whether this score, measured before surgical procedures, could predict postoperative cancer-specific survival.
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Microanalysis of a grain boundarys blocking effect in lanthanum silicate electrolyte for intermediate-temperature solid oxide fuel cells.
ACS Appl Mater Interfaces
PUBLISHED: 06-03-2013
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In order to study the grain boundarys (GBs) blocking effect in lanthanum silicate electrolyte, high density Al-doped apatite-type lanthanum silicate was synthesized and characterized by impedance spectroscopy, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. Microstructural characterization indicated that the GBs blocking effect was an intrinsic effect. Further microanalysis shows that the GB region is rich in La and poor in Si in comparing with the grain interior (GI). Our discussion suggested that the chemical variation from GI to GB, on the one hand, could degrade the GB regions conductivity; on the other hand, it introduced a strong space-charge effect at GBs. The latter was believed to play a dominant role in the GBs blocking effect.
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Gamete membrane dynamics during double fertilization in Arabidopsis.
Plant Signal Behav
PUBLISHED: 04-19-2013
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In the double fertilization of angiosperms, one sperm cell fertilizes an egg cell to produce a zygote, whereas the other sperm cell fertilizes a central cell to give rise to an endosperm. There is little information on gamete membrane dynamics during double fertilization even though the cell surface structure is critical for male and female gamete interactions. In a recent study, we analyzed gamete membrane behavior during double fertilization by live-cell imaging with Arabidopsis gamete membrane marker lines. We observed that the sperm membrane signals occasionally remained at the boundary of the female gametes after gamete fusion. In addition, sperm membrane signals entering the fertilized female gametes were detected. These findings suggested that plasma membrane fusion between male and female gametes occurred with the sperm internal membrane components entering the female gametes, and this was followed by plasmogamy.
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Recent developments in gastric endoscopic submucosal dissection: towards the era of endoscopic resection of layers deeper than the submucosa.
Dig Endosc
PUBLISHED: 01-24-2013
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With technical advances in endoscopic submucosal dissection (ESD), several variations of endoscopic procedure derived from ESD and fusion procedures of endoscopy and laparoscopy for upper gastrointestinal submucosal tumor and cancer have recently been developed. The former includes endoscopic muscularis dissection (EMD), submucosal endoscopic tumor resection (SET), endoscopic submucosal tunnel dissection (ESTD) and endoscopic full-thickness resection (EFTR), and the latter includes laparoscopic and endoscopic cooperative surgery (LECS), laparoscopy-assisted endoscopic full-thickness resection (LAEFR), and laparoscopic lymphadenectomy without gastrectomy following ESD. In the present article, recent developments in gastric ESD and advanced procedures derived from ESD are discussed.
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Microstructural and chemical characterization of ordered structure in yttrium doped ceria.
Microsc. Microanal.
PUBLISHED: 01-11-2013
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The ordered structures in different doping levels (x = 0.1, 0.15, 0.2, 0.25, 0.3) of yttrium doped ceria (YDC, Ce(1-x)Y x O2-?) electrolytes were investigated by electron diffraction, high-resolution transmission electron microscopy (TEM), scanning TEM, and electron energy loss spectroscopy. Oxygen vacancy ordering was experimentally confirmed within the ordered structures. With increasing the doping level, the concentration of trivalent Ce cations was increased in YDC samples and such trivalent Ce cations were supposed to mainly exist in the ordered structures. Based on our electron microscopic observation and microanalysis, a crystal model for the ordered structures is proposed.
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Microstructural evolution in a CeO2-Gd2O3 system.
Microsc. Microanal.
PUBLISHED: 12-15-2011
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Microstructural evolution in a CeO2-Gd2O3 system at atomic and nanoscale levels with increasing Gd concentration has been comprehensively investigated by transmission electron microscopy. When the Gd concentration was increased from 10 to 80 at.%, the phase transformation from ceria with fluorite structure to solid solution with C-type structure was not a sudden change but an evolution in the sequence of clusters, domains, and precipitates with C-type structure in the fluorite-structured matrix. Moreover, the ordering of aggregated Gd cations and oxygen vacancies in these microstructural inhomogeneities developed continuously with increasing Gd concentration. This microstructural evolution can be further described based on the development of defect clusters containing Gd cations and oxygen vacancies.
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Predictive factors for cholangiocarcinoma associated with hepatolithiasis determined on the basis of Japanese Multicenter study.
Hepatol. Res.
PUBLISHED: 12-13-2011
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Aim:? The aim of this study was to delineate predictive factors for cholangiocarcinoma in patients with hepatolithiasis, and to establish optimal management for hepatolithiasis from the viewpoint of carcinogenesis on the basis of a Japanese nationwide survey for hepatolithiasis. Methods:? The Hepatolithiasis Research Group was organized in 2006 by the Ministry of Health, Labour and Welfare of Japan, and conducted a nationwide survey. The research group collected data on 336 cases of hepatolithiasis in 2006, in a cross-sectional survey involving 2592 institutions in Japan. Predictive factors for cholangiocarcinoma associated with hepatolithiasis were analyzed by univariate and multivariate analyses of clinicopathological and therapeutic factors. Results:? Twenty-three patients had cholangiocarcinoma. Histories of choledocoenterostomy and liver atrophy were found to be significantly predictive factors by multivariate analysis. In 87.5% of cases of cholangiocarcinoma with liver atrophy, cholangiocarcinoma was located in the atrophic lobes. The method of reconstruction did not affect the incidence of cholangiocarcinoma (choledochojejunostomy vs. choledochoduodenostomy; side-to-end vs. side-to-side anastomosis). Conclusions:? Choledocoenterostomy and liver atrophy may increase the risk of developing cholangiocarcinoma. Choledocoenterostomy is thus contraindicated in patients with hepatolithiasis. An aggressive resection strategy is recommended for an atrophic segment.
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Morphological control of porous SiC templated by As-synthesized form of mesoporous silica.
J Nanosci Nanotechnol
PUBLISHED: 11-23-2011
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Porous silicon carbide with fiber like morphology was successfully prepared via a hard templating approach using as-synthesized form of mesoporous silica SBA-15 as template and sucrose as carbon precursor. The obtained materials have been characterized by various sophisticated techniques such as XRD, nitrogen adsorption, HRTEM, HRSEM, FT-IR and TGA. The XRD and the nitrogen adsorption results revealed that the materials are highly crystalline and exhibit porous structure with excellent textural characteristics. It has been demonstrated that the morphology of the materials can be finely controlled from rod shaped morphology to fiber like nanostructures by the simple adjustment of the reaction time from 5 to 12 h at the reaction temperature of 1300 degrees C. The reaction time of 12 h at 1300 degrees C was found to be the best condition to obtain highly crystalline nanofiber like morphology. The obtained materials display beautiful nanofiber morphology which has the diameter of 20 to 60 nm and a length of 7 to 10 microm which is much longer than the previously reported SiC nanofibers.
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Overexpression of KLF15 transcription factor in adipocytes of mice results in down-regulation of SCD1 protein expression in adipocytes and consequent enhancement of glucose-induced insulin secretion.
J. Biol. Chem.
PUBLISHED: 08-23-2011
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Krüppel-like factor 15 (KLF15), a member of the Krüppel-like factor family of transcription factors, has been found to play diverse roles in adipocytes in vitro. However, little is known of the function of KLF15 in adipocytes in vivo. We have now found that the expression of KLF15 in adipose tissue is down-regulated in obese mice, and we therefore generated adipose tissue-specific KLF15 transgenic (aP2-KLF15 Tg) mice to investigate the possible contribution of KLF15 to various pathological conditions associated with obesity in vivo. The aP2-KLF15 Tg mice manifest insulin resistance and are resistant to the development of obesity induced by maintenance on a high fat diet. However, they also exhibit improved glucose tolerance as a result of enhanced insulin secretion. Furthermore, this enhancement of insulin secretion was shown to result from down-regulation of the expression of stearoyl-CoA desaturase 1 (SCD1) in white adipose tissue and a consequent reduced level of oxidative stress. This is supported by the findings that restoration of SCD1 expression in white adipose tissue of aP2-KLF15 Tg mice exhibited increased oxidative stress in white adipose tissue and reduced insulin secretion with hyperglycemia. Our data thus provide an example of cross-talk between white adipose tissue and pancreatic ? cells mediated through modulation of oxidative stress.
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Which is the preference of choice either life with a stoma or evacuatory disorder following rectal cancer surgery?
Hepatogastroenterology
PUBLISHED: 08-12-2011
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Low anastomosis with covering stoma is the standard operation for low rectal carcinoma. Some patients experience severe anorectal disorder, which makes us consider whether stoma closure should be performed or not. There was no comparative study between life with a stoma and life with evacuatory disorder.
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Mutual diffusion occurring at the interface between La?.?Sr?.?Co?.?Fe?.?O? cathode and Gd-doped ceria electrolyte during IT-SOFC cell preparation.
ACS Appl Mater Interfaces
PUBLISHED: 06-29-2011
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The microstructure and local chemistry of the interface between the screen-printed La(0.6)Sr(0.4)Co(0.8)Fe(0.2)O(3) (LSCF) thin film cathode and Gd-doped ceria (GDC) electrolyte substrate have been investigated. Elemental distribution analyses, by energy-dispersive X-ray spectroscopy operated in scanning transmission electron microscopy (STEM) mode, illustrate that all constituent elements in GDC and LSCF mutually diffuse across the LSCF/GDC interface, with equal diffusion length. This leads to the formation of mutual diffusion zones at the LSCF/GDC interfaces, with the resultant mixture of diffusing ions being associated with specific valence state changes, as verified by STEM electron energy loss spectroscopy analyses. Moreover, this mutual diffusion can result in microstructural changes, where superstructure formation is accompanied by enhancement of oxygen vacancy ordering at this region. Such mutual diffusion and associated microstructure evolution is considered to be detrimental to fuel cell efficiency and should be suppressed by lowering cell fabrication temperatures.
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Ordered structures of defect clusters in gadolinium-doped ceria.
J Chem Phys
PUBLISHED: 06-21-2011
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The nano-domain, with short-range ordered structure, has been widely observed in rare-earth-doped ceria. Atomistic simulation has been employed to investigate the ordering structure of the nano-domain, as a result of aggregation and segregation of dopant cations and the associated oxygen vacancies in gadolinium-doped ceria. It is found that the binding energy of defect cluster increases as a function of cluster size, which provides the intrinsic driving force for the defect cluster growth. However, the ordered structures of the defect clusters are different from the chain model as previously reported. Adjacent oxygen vacancies prefer to locate along <110>/2 lattice vector, which results in a unique stable structure (isosceles triangle) formation. Such isosceles triangle structure can act as the smallest unit of cluster growth to form a symmetric dumbbell structure. This unique dumbbell structure is hence considered as a building block for the development of larger defect clusters, leading to nano-domain formation in rare-earth-doped ceria.
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Putting the N in ACENE: pyrazinacenes and their structural relatives.
Org. Biomol. Chem.
PUBLISHED: 06-07-2011
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Acenes have emerged as an important class of organic electronic material. Related heteroatom-substituted compounds, or heteroacenes, introduce an important means for modulating properties and improving materials stability. In this perspective, we will review the historical origins of the heteroacenes and discuss recent progress in the field of acene and related compounds containing fused 1,4-diazabenzene units, i.e. pyrazine, also known as the pyrazinacenes. We focus not only on the types of materials that have been prepared but also on their chemical and physical properties, including synthetic procedures, electronic properties, self-assembly characteristics, and we also introduce some of the computational studies aimed at understanding the more unusual behaviours of this group of compounds, such as protic tautomerism and aromaticity/antiaromaticity.
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Long-term outcomes of combination of endoscopic submucosal dissection and laparoscopic lymph node dissection without gastrectomy for early gastric cancer patients who have a potential risk of lymph node metastasis.
Gastrointest. Endosc.
PUBLISHED: 04-16-2011
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Our recently developed procedure, a combination of endoscopic submucosal dissection (ESD) and laparoscopic lymph node dissection (LLND), may lead to the elimination of unnecessary gastrectomy in early gastric cancer (EGC) patients having a potential risk of lymph node metastasis (LNM).
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Superstructure formation and variation in Ni-GDC cermet anodes in SOFC.
Phys Chem Chem Phys
PUBLISHED: 04-15-2011
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The microstructures and spatial distributions of constituent elements at the anode in solid oxide fuel cells (SOFCs) have been characterized by analytical transmission electron microscopy (TEM). High resolution TEM observations demonstrate two different types of superstructure formation in grain interiors and at grain boundaries. Energy-filtered TEM elemental imaging qualitatively reveals that mixture zones exist at metal-ceramic grain boundaries, which is also quantitatively verified by STEM energy dispersive X-ray spectroscopy. It was apparent that both metallic Ni and the rare-earth elements Ce/Gd in gadolinium-doped ceria can diffuse into each other with equal diffusion lengths (about 100 nm). This will lead to the existence of mutual diffusion zones at grain boundaries, accompanied by a change in the valence state of the diffusing ions, as identified by electron energy-loss spectroscopy (EELS). Such mutual diffusion is believed to be the dominant factor that gives rise to superstructure formation at grain boundaries, while a different superstructure is formed at grain interiors, as a consequence solely of the reduction of Ce(4+) to Ce(3+) during H(2) treatment. This work will enhance the fundamental understanding of microstructural evolution at the anode, correlating with advancements in sample preparation in order to improve the performance of SOFC anodes.
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Defect clustering and local ordering in rare earth co-doped ceria.
Phys Chem Chem Phys
PUBLISHED: 04-12-2011
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Defect clustering and local ordering in rare earth co-doped ceria were studied by computer simulation and electron diffraction, respectively. The simulation of electrically neutral defect clusters containing up to four oxygen vacancies revealed that the permutation of different dopant cations in a co-doped cluster could have a significant influence on the binding energy of the cluster. Moreover, the growth of larger clusters (number of oxygen vacancies ? 3) could be restrained by a co-doping effect. The selected area electron diffraction study indicated that the restrained growth of larger clusters will further lead to a suppression of the local ordering of oxygen vacancies in co-doped ceria. The correlation between defect clustering, local ordering of oxygen vacancies and ionic conduction in co-doped ceria was discussed.
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Microstructural and metal-support interactions of the Pt-CeO2/C catalysts for direct methanol fuel cell application.
Langmuir
PUBLISHED: 03-11-2011
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To understand the ceria promotion effect of Pt-CeO(2)/C catalysts on methanol oxidation, microstructural and metal-oxide interactions of Pt-CeO(2)/C catalysts with an atomic ratio of Pt/Ce between 0.14 and 1.4 were systematically examined using high-resolution transmission electron microscopy and electron energy loss spectroscopy (EELS). With an increasing Pt content in the catalysts, Pt particles gradually invaded into the ceria supports and decoration on Pt particles was observed. Simultaneously, the morphology of the supports was dramatically modified with nanocrystalline and amorphous ceria formed between and/or around the Pt particles. It reveals that the Pt-ceria interaction could take place in the catalysts and the influence of the interaction was enhanced with an increasing Pt/Ce ratio. The EELS study demonstrated that the strong Pt-ceria interaction was related to the redox reaction between Pt and ceria. Experimental results also suggested that the strong interaction between Pt and ceria could contribute to the promotion effect of ceria on the oxidation of methanol.
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Highly crystalline and conductive nitrogen-doped mesoporous carbon with graphitic walls and its electrochemical performance.
Chemistry
PUBLISHED: 02-17-2011
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We present a rational and simple methodology to fabricate highly conductive nitrogen-doped ordered mesoporous carbon with a graphitic wall structure by the simple adjustment of the carbonization temperature of mesoporous carbon nitride without the addition of any external nitrogen sources. By simply controlling the heat-treatment temperature, the structural order and intrinsic properties such as surface area, conductivity, and pore volume, and the nitrogen content of ordered graphitic mesoporous carbon can be controlled. Among the materials studied, the sample heat-treated at 1000? °C shows the highest conductivity, which is 32 times higher than that for the samples treated at 800? °C and retains the well-ordered mesoporous structure of the parent mesoporous carbon nitride and a reasonable amount of nitrogen in the graphitic framework. Since these materials exhibit high conductivity with the nitrogen atoms in the graphitic framework, we further demonstrate their use as a support for nanoparticle fabrication without the addition of any external stabilizing or size-controlling agent, as well as the anode electrode catalysts. Highly dispersed platinum nanoparticles with a size similar to that of the pore diameter of the support can be fabricated since the nitrogen atoms and the well-ordered porous structure in the mesoporous graphitic carbon framework act as a stabilizing and size-controlling agent, respectively. Furthermore the Pt-loaded, nitrogen-doped mesoporous graphitic carbon sample with a high conductivity shows much higher anodic electrocatalytic activity than the other materials used in the study.
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DNA packaging proteins Glom and Glom2 coordinately organize the mitochondrial nucleoid of Physarum polycephalum.
Mitochondrion
PUBLISHED: 02-03-2011
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Mitochondrial DNA (mtDNA) is generally packaged into the mitochondrial nucleoid (mt-nucleoid) by a high-mobility group (HMG) protein. Glom is an mtDNA-packaging HMG protein in Physarum polycephalum. Here we identified a new mtDNA-packaging protein, Glom2, which had a region homologous with yeast Mgm101. Glom2 could bind to an entire mtDNA and worked synergistically with Glom for condensation of mtDNA in vitro. Down-regulation of Glom2 enhanced the alteration of mt-nucleoid morphology and the loss of mtDNA induced by down-regulation of Glom, and impaired mRNA accumulation of some mtDNA-encoded genes. These data suggest that Glom2 may organize the mt-nucleoid coordinately with Glom.
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Tautomers of extended reduced pyrazinacenes: a density-functional-theory based study.
Phys Chem Chem Phys
PUBLISHED: 12-06-2010
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We present a structural and electronic inspection of reduced pyrazinacenes within the DFT framework. Our analysis provides a clear indication that compounds in which reduced pyrazine rings are well separated from each other are rather stable. Conversely, if the reduced pyrazine rings approach each other or cluster together, the compounds become increasingly unstable. The tautomers analyzed are likely to possess properties suitable for application as proton transport materials due to protic isomerism processes. On the basis of our findings, we propose that protic transport should occur through a concerted proton transfer without involving intramolecular aggregation of the dihydropyrazine groups. Furthermore, the electronic structure analysis shows that this class of compounds can be classified as small bandgap semiconducting materials, possessing even metallic character depending on the tautomeric structure, and with potential nanotechnological applications in molecular electronics and fuel cells.
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Dislocation associated incubational domain formation in lightly gadolinium-doped ceria.
Microsc. Microanal.
PUBLISHED: 11-19-2010
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Nanosized incubational domain was observed in 10 at.% gadolinium-doped ceria (GDC) using high-resolution transmission electron microscopy. Dislocations were extensively observed in 10 at.% GDC instead of heavily doped 25 at.% GDC. By Fast Fourier Transform and Inverse Fast Fourier Transform analysis, it was noticed that the incubational domain existing in 10 at.% GDC has different lattice spacing and orientation from the neighboring ceria matrix. Furthermore, dislocations were usually observed in the interface region between the incubational domain and the ceria matrix. Based on experimental results, the formation mechanism of dislocation associated incubational domain in lightly gadolinium-doped ceria is rationalized.
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Advanced ampullary carcinoma showing complete response to S-1: report of a case.
Surg. Today
PUBLISHED: 05-23-2010
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We report a case of advanced ampullary carcinoma with para-aortic lymph node metastasis, which showed a complete response to S-1. The patient underwent cholecystectomy and Roux-en-Y choledochojejunostomy, and was then given S-1 orally 80 mg daily for 14 days, followed by 7 days of rest. After four cycles of the S-1 chemotherapy, both the tumor and the swollen paraaortic lymph node had completely disappeared. An additional six cycles were given at the request of the patient. No adverse effects were seen during the S-1 chemotherapy, and the patient has been free of the disease for the 27 months since its completion. Thus, S-1 monotherapy may be considered as a chemotherapeutic strategy for unresectable ampullary carcinoma, although large-scale studies will be required to confirm its true efficacy.
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Phosphorus-doped carbon nitride solid: enhanced electrical conductivity and photocurrent generation.
J. Am. Chem. Soc.
PUBLISHED: 04-20-2010
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As a new kind of polymeric semiconductors, graphitic carbon nitride (g-C(3)N(4)) and its incompletely condensed precursors are stable up to 550 degrees C in air and have shown promising photovoltaic applications. However, for practical applications, their efficiency, limited e.g. by band gap absorption, needs further improvement. Here we report a "structural doping" strategy, in which phosphorus heteroatoms were doped into g-C(3)N(4) via carbon sites by polycondensation of the mixture of the carbon nitride precursors and phosphorus source (specifically from 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid). Most of the structural features of g-C(3)N(4) were well retained after doping, but electronic features had been seriously altered, which provided not only a much better electrical (dark) conductivity up to 4 orders of magnitude but also an improvement in photocurrent generation by a factor of up to 5. In addition to being active layers in solar cells, such phosphorus-containing scaffolds and materials are also interesting for polymeric batteries as well as for catalysis and as catalytic supports.
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Skill accreditation system for laparoscopic gastroenterologic surgeons in Japan.
Minim Invasive Ther Allied Technol
PUBLISHED: 01-26-2010
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The Japan Society for Endoscopic Surgery (JSES) has established an Endoscopic Surgical Skill Qualification System and started examination in 2004. Non-edited videotapes were assessed by two judges in a double-blinded fashion with strict criteria. Two kinds of criteria, namely common and procedure-specific, were prepared. The common criteria were designed to evaluate set-ups, autonomy of the operator, display of the surgical field, recognition of surgical anatomy, co-operation of the surgical team. The procedure-specific criteria were made to assess the operation in a step-by-step fashion. In total, out of 1.114 surgeons who were assessed by this qualification system over a period of four years, 537 (48.2%) have been accredited. The qualification rate in each surgical field has remained at the same level of 40 to 50% to date. Inter-rater agreement of two judges was low at 0.31 in the first year, but improved with revision of the criteria and consensus meetings. Surgeons assessed by this system as qualified experienced less frequent complications when compared to those who failed. This system has impacted on the improvement and standardization of laparoscopic surgery in Japan.
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Neurophysiologic investigation of anal function following double stapling anastomosis.
Dig Surg
PUBLISHED: 01-23-2010
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Manual dilatation of the anal sphincter and transanal introduction of the circular stapling device are required for intraluminal stapling anastomosis. This procedure has been regarded as one of the causes of postoperative evacuatory disorder in low anterior resection. However, there has been no evidence of this matter. Therefore, we conducted this study to clarify the impact of the procedure of stapling anastomosis on postoperative anal function.
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Pyrazinacenes: aza analogues of acenes.
J. Org. Chem.
PUBLISHED: 11-04-2009
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A series of edge-sharing condensed oligopyrazine analogues of acenes, the pyrazinacenes, were synthesized and characterized. X-ray crystallographic determinations revealed intermolecular interactions that affect the propensity of the molecules to undergo pi-pi stacking. Increasing heteroatom substitution of the acene framework induces shorter intermolecular pi-pi stacking distances (shorter than for graphite) probably due to lower van der Waals radius of nitrogen atoms. Hydrogen bonding is also a determining factor in the case of compounds containing reduced pyrazine rings. Combined electrochemical, electronic absorption, and computational investigations indicate the substantial electron deficiency of the compounds composed of fused pyrazine rings. The pyrazinacenes are expected to be good candidates as materials for organic thin film transistors.
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Expression of the Cyanidioschyzon merolae stromal ascorbate peroxidase in Arabidopsis thaliana enhances thermotolerance.
Plant Cell Rep.
PUBLISHED: 08-31-2009
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The ability of the primitive red alga Cyanidioschyzon merolae to adapt to high temperatures was utilized to produce thermotolerant transgenic plants. C. merolae inhabits an extreme environment (42 degrees C, pH 2.5) and the nuclear, mitochondrial, and plastid genomes have been sequenced. We analyzed expressed sequence tag (EST) data to reveal mechanisms of tolerance to high temperatures. The stromal ascorbate peroxidase (CmstAPX) that scavenges reactive oxygen species (ROS) was expressed at high levels (4th of 4,479 entries), thus, it offers clues to understanding high-temperature tolerance. CmstAPX has a chloroplast transit peptide (cTP) and a peroxidase domain. The peroxidase domain of CmstAPX has deletions and insertions when compared with that of Arabidopsis thaliana stromal APX (AtstAPX). To clarify aspects of tolerance to oxidative and high-temperature stress, we produced transgenic A. thaliana plants overexpressing CmstAPX and AtstAPX. CmstAPX plants showed higher activities of soluble APX than those of wild-type and AtstAPX plants. Fluorescence signals of a GFP fusion protein, immuno-fluorescence, and immunogold electron microscopy showed that CmstAPX was localized in the stroma of chloroplasts. Compared with wild-type plants and AtstAPX plants, CmstAPX plants were more tolerant to oxidative stress induced by methylviologen (MV, 0.4 muM) and high-temperature stress (33 degrees C). CmstAPX plants retained the highest chlorophyll content when treated with MV and high temperature, and their stroma and chloroplasts remained intact in their chloroplasts, whereas they disintegrated in wild-type plants. Our results suggest that the increased activity of APX in the chloroplasts of CmstAPX plants increased thermotolerance by increasing ROS-scavenging capacity at high temperatures.
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Cholecystectomy by a combined transgastric and transparietal approach using two flexible endoscopes.
J Hepatobiliary Pancreat Surg
PUBLISHED: 07-23-2009
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This experimental study was designed to assess the technical feasibility and benefits of our novel approach for transgastric NOTES (natural orifice translumenal endoscopic surgery) cholecystectomy.
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The PLASTID DIVISION1 and 2 components of the chloroplast division machinery determine the rate of chloroplast division in land plant cell differentiation.
Plant Cell
PUBLISHED: 06-30-2009
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In most algae, the chloroplast division rate is held constant to maintain the proper number of chloroplasts per cell. By contrast, land plants evolved cell and chloroplast differentiation systems in which the size and number of chloroplasts change along with their respective cellular function by regulation of the division rate. Here, we show that PLASTID DIVISION (PDV) proteins, land plant-specific components of the division apparatus, determine the rate of chloroplast division. Overexpression of PDV proteins in the angiosperm Arabidopsis thaliana and the moss Physcomitrella patens increased the number but decreased the size of chloroplasts; reduction of PDV levels resulted in the opposite effect. The level of PDV proteins, but not other division components, decreased during leaf development, during which the chloroplast division rate also decreased. Exogenous cytokinins or overexpression of the cytokinin-responsive transcription factor CYTOKININ RESPONSE FACTOR2 increased the chloroplast division rate, where PDV proteins, but not other components of the division apparatus, were upregulated. These results suggest that the integration of PDV proteins into the division machinery enabled land plant cells to change chloroplast size and number in accord with the fate of cell differentiation.
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Paclitaxel-induced interstitial pneumonia after drug-eluting stent implantation: report of a fatal case.
Intern. Med.
PUBLISHED: 06-01-2009
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We report a case of paclitaxel-eluting stent implantation in an angina patient who developed interstitial pneumonia a few days afterward, and succumbed to fatal respiratory dysfunction despite corticosteroid therapy. Paclitaxel is an anti-neoplastic agent currently used as a coating substance for coronary stents to reduce the rate of restenosis. Pulmonary toxicity related to paclitaxel is not very common; however, this adverse event may on occasion be lethal. Although the efficacy and safety of drug-eluting stents for the treatment of ischemic heart disease is well established, physicians should keep in mind that paclitaxel-eluting stents have the potential to cause interstitial pneumonia.
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Fertilization is a novel attacking site for the transmission blocking of malaria parasites.
Acta Trop.
PUBLISHED: 05-28-2009
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Malaria parasites perform sexual reproduction in mosquitoes where a pair of gametes fertilizes and differentiates into zygotes, and a single zygote produces several thousands of progeny infectious to next vertebrates. Although the parasite fertilization step has been considered as Achilles heel of parasite life cycle and thus a critical target for blocking malaria transmission in the mosquito, its molecular mechanisms are largely unknown. Previously, we identified that GENERATIVE CELL SPECIFIC 1 (GCS1) is a reproduction factor in angiosperm. Subsequently, it was found that rodent malaria parasite, Plasmodium berghei and green algae, Chlamydomonas reinhardtii possess GCS1 homologues which also play essential roles in gamete interaction. Moreover, intensive database mining revealed that GCS1-like gene homologues exist in the genomes of various organisms. Thus, it appears that GCS1 is an ancient and highly conserved molecule functioning at gamete interaction. In this mini-review, we describe the mechanisms of gametogenesis and fertilization in malaria parasites, comparing with other eukaryotic reproduction, and also speculate GCS1 functions in gamete interaction. We discuss the possibility of whether malaria GCS1 is a novel type of transmission blocking vaccine, by which anti-malaria GCS1 antibody may halt parasite fertilization and subsequent developments in the mosquitoes.
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Secure placement of a peripancreatic drain after a distal pancreatectomy.
Am. J. Surg.
PUBLISHED: 03-23-2009
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A peripancreatic drain that is placed after a distal pancreatectomy sometimes migrates and becomes ineffective postoperatively. We devised a new drainage method with fixation of the tip of a peripancreatic drain using a loose loop of an absorbable suture.
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Diverse self-assembly in soluble oligoazaacenes: a microscopy study.
Langmuir
PUBLISHED: 03-14-2009
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The synthesis and morphologies of self-assembled aggregates of novel oligoazapentacene 2 and oligoazaheptacene 3 derivatives are reported. Double nucleophilic substitution on 2,3-dicyano-[h,j]-dibenzo-1,4,5,10-tetrazaanthracene 4 gives the corresponding dihydro-oligoacene derivatives, which were then N-alkylated using n-dodecyl bromide to yield self-assembling acene molecules. 2 and 3 self-assemble in solution, leading to a variety of aggregated structures including rolled-up sheets, foams, and fibrous structures reminiscent of organogels. These structures are of substantial interest because of their potential electronic properties and because individual fibers can be "exfoliated". Structures of the aggregates are discussed. Additionally, the crystal structure of precursor 4 is reported because it gives information regarding the intermolecular interactions (hydrogen bonding and intermolecular stacking) in similar compounds. Crystal data for 4: space group P2(1)/n, a = 9.3164(17) angstroms, b = 7.0649(13) angstroms, c = 23.684(4) angstroms, alpha = 90.00 degrees, beta = 99.945(3) degrees, gamma = 90.00 degrees, and V = 1535.4(5) angstroms3.
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Single-port endoscopic cholecystectomy: a bridge between laparoscopic and translumenal endoscopic surgery.
J Hepatobiliary Pancreat Surg
PUBLISHED: 02-19-2009
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The intentional puncture of the normal viscera is likely the most important issue limiting the widespread use of natural orifice translumenal endoscopic surgery (NOTES). We developed a new procedure for cholecystectomy using a flexible endoscope via a single port placed in the abdominal wall without visceral puncture (single-port endoscopic cholecystectomy; SPEC) as a bridge between laparoscopic surgery and NOTES. This study aimed to evaluate the technical feasibility of SPEC.
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Discovery and characterization of a peptide motif that specifically recognizes a non-native conformation of human IgG induced by acidic pH conditions.
J. Biol. Chem.
PUBLISHED: 02-19-2009
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In therapeutic antibody preparation, acidic pH conditions are generally used for elution from Protein A affinity column of IgG or for its viral inactivation. Exposing IgG to low pH conditions induces conformational changes, leading to its functional damage or loss, although the mechanisms have not been fully elucidated. In this study using random peptide T7 phage display libraries, we isolated a unique and novel peptide motif that specifically recognized the non-native conformer (acid conformer) of human IgG that was generated by the low pH treatment, but not the native conformer. We examined the generation conditions and biochemical properties of acid conformer using the peptide motif as an affinity ligand. The acid conformer was easily generated at acidic pH (25 degrees C). The peptides isolated here could contribute to the elucidation of the mechanisms of antibody dysfunction or aggregation during acid exposure as well as storage of human IgG.
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Endoscopic full-thickness resection with laparoscopic assistance as hybrid NOTES for gastric submucosal tumor.
Surg Endosc
PUBLISHED: 01-30-2009
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Laparoscopic wedge resection using a linear stapler is widely accepted as a treatment for gastric submucosal tumor (SMT). Although this surgery is simple, it can lead to excessive normal tissue removal. To avoid the latter, we have introduced endoscopic full-thickness resection with laparoscopic assistance, known as laparoscopy-assisted endoscopic full-thickness resection (LAEFR). Herein, we present the preliminary results of LAEFR for gastric SMT patients.
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Modified liver hanging maneuver with extraparenchymal isolation of the middle hepatic vein in left hepatectomy.
J Hepatobiliary Pancreat Surg
PUBLISHED: 01-30-2009
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The liver hanging maneuver has been employed mostly for right hepatectomy. After the space between the inferior vena cava and the liver parenchyma is bluntly dissected, a tape is passed through the space, with the upper end of the tape between the right hepatic vein and middle hepatic vein (MHV). We devised a modified maneuver with tape repositioning between the MHV and left hepatic vein (LHV) after extraparenchymal isolation of the MHV, in left hepatectomy with the caudate lobe and without the MHV.
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Acute interstitial pneumonitis after implantation of paclitaxel-eluting stents: a report of two fatal cases.
Int. J. Cardiol.
PUBLISHED: 01-28-2009
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Paclitaxel is an anti-neoplastic agent widely used as a coating substance for coronary stents to reduce the rate of restenosis. Although the release rate of paclitaxel from stents is quite slow and the dose of paclitaxel is extremely small, long-term safety and avoidance of potentially lethal pulmonary damage is not well established. We report two cases of paclitaxel-eluting stent implantation in ischemic heart disease patients who developed acute interstitial pneumonitis a few days afterward, and who succumbed to fatal respiratory dysfunction despite corticosteroid therapy. Based upon the clinical course and autopsy findings in these two patients, paclitaxel eluted from the stent may have played a causal role in the development of acute interstitial pneumonitis. Physicians should bear in mind that paclitaxel has the potential of causing acute interstitial pneumonitis not only when used for anti-neoplastic therapy, but also following stent implantation, where the objective is to inhibit coronary neointimal proliferation.
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Falciform ligament in pancreatoduodenectomy for protection of skeletonized and divided vessels.
J Hepatobiliary Pancreat Surg
PUBLISHED: 01-24-2009
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Pancreatic fistula, which is one of the main causes of late postpancreatectomy hemorrhage (PPH), is a common complication of pancreatoduodenectomy (PD). It may erode the anastomosis site and vascular wall in its vicinity, resulting in pseudoaneurysm formation and/or the rupture of major vessels. To protect the vessels near the area for pancreaticojejunostomy from potential pancreatic fistula, we have adopted a surgical option by which such vessels are separated from the pancreaticojejunostomy using a pedicled falciform ligament. We reviewed 36 patients who underwent PD that included this option.
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Pancreatic duct holder for facilitating duct-to-mucosa pancreatojejunostomy after pancreatoduodenectomy.
Am. J. Surg.
PUBLISHED: 01-23-2009
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Duct-to-mucosa pancreatojejunostomy after pancreatoduodenectomy may be technically difficult, particularly in cases in which the remnant pancreas is soft with a small main pancreatic duct. We devised a pancreatic duct holder for duct-to-mucosa pancreatojejunostomy. The holder has a cone-shaped tip. A one-third circle of the tip is cut away, which makes a slit. As the tip is inserted gently into the pancreatic duct, the duct can be adequately expanded. The holder provides a good surgical field for anastomosis. A slit of the tip allows needle insertion. The holder facilitates stitches of the jejunum also. Twelve patients underwent pancreatoduodenectomy, followed by duct-to-mucosa pancreatojejunostomy using the holder. The holder allowed 8 or more stitches in duct-to-mucosa anastomosis, even in patients with a small pancreatic duct. No patients developed prolonged pancreatic leakage or pancreatic fistula postoperatively. In conclusion, the pancreatic duct holder is a simple and useful tool for facilitating duct-to-mucosa pancreatojejunostomy.
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Periodic gene expression patterns during the highly synchronized cell nucleus and organelle division cycles in the unicellular red alga Cyanidioschyzon merolae.
DNA Res.
PUBLISHED: 01-14-2009
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Previous cell cycle studies have been based on cell-nuclear proliferation only. Eukaryotic cells, however, have double membranes-bound organelles, such as the cell nucleus, mitochondrion, plastids and single-membrane-bound organelles such as ER, the Golgi body, vacuoles (lysosomes) and microbodies. Organelle proliferations, which are very important for cell functions, are poorly understood. To clarify this, we performed a microarray analysis during the cell cycle of Cyanidioschyzon merolae. C. merolae cells contain a minimum set of organelles that divide synchronously. The nuclear, mitochondrial and plastid genomes were completely sequenced. The results showed that, of 158 genes induced during the S or G2-M phase, 93 were known and contained genes related to mitochondrial division, ftsZ1-1, ftsz1-2 and mda1, and plastid division, ftsZ2-1, ftsZ2-2 and cmdnm2. Moreover, three genes, involved in vesicle trafficking between the single-membrane organelles such as vps29 and the Rab family protein, were identified and might be related to partitioning of single-membrane-bound organelles. In other genes, 46 were hypothetical and 19 were hypothetical conserved. The possibility of finding novel organelle division genes from hypothetical and hypothetical conserved genes in the S and G2-M expression groups is discussed.
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A plant germline-specific integrator of sperm specification and cell cycle progression.
PLoS Genet.
PUBLISHED: 01-08-2009
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The unique double fertilisation mechanism in flowering plants depends upon a pair of functional sperm cells. During male gametogenesis, each haploid microspore undergoes an asymmetric division to produce a large, non-germline vegetative cell and a single germ cell that divides once to produce the sperm cell pair. Despite the importance of sperm cells in plant reproduction, relatively little is known about the molecular mechanisms controlling germ cell proliferation and specification. Here, we investigate the role of the Arabidopsis male germline-specific Myb protein DUO POLLEN1, DUO1, as a positive regulator of male germline development. We show that DUO1 is required for correct male germ cell differentiation including the expression of key genes required for fertilisation. DUO1 is also necessary for male germ cell division, and we show that DUO1 is required for the germline expression of the G2/M regulator AtCycB1;1 and that AtCycB1:1 can partially rescue defective germ cell division in duo1. We further show that the male germline-restricted expression of DUO1 depends upon positive promoter elements and not upon a proposed repressor binding site. Thus, DUO1 is a key regulator in the production of functional sperm cells in flowering plants that has a novel integrative role linking gametic cell specification and cell cycle progression.
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Improvement of cathode performance on Pt-CeO(x) by optimization of electrochemical pretreatment condition for PEFC application.
Langmuir
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Pt-CeO(x)/C electrocatalysts for the improvement of oxygen reduction reaction (ORR) activity on cathode were prepared by a combined process of precipitation and co-impregnation methods. The Pt-CeO(x)/C electrocatalysts pretreated by the optimized electrochemical conditioning process showed high ORR activity as compared with homemade Pt/C electrocatalyst. Also, it showed high stability in the cyclic voltammetry (CV) test up to 1000 cycles into 0.5 M H(2)SO(4) aqueous solution. On the basis of the data of cyclic voltammogram of 30 cyclic sweeps, X-ray photoelectron spectroscopy, electron energy loss spectroscopy, high resolution transmission electron microscope image, and selected area electron diffraction analysis, it is concluded that the Pt-CeO(x) heterointerface involving the defect cluster formed by using optimized electrochemical pretreatment conditions on Pt in Pt-CeO(x)/C electro-catalyst contributes to the promotion of ORR activity and retention of its stability in long CV tests up to 1000 cycles.
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Analysis of gamete membrane dynamics during double fertilization of Arabidopsis.
J. Plant Res.
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Angiosperms have a unique sexual reproduction system called "double fertilization." One sperm cell fertilizes the egg and another sperm cell fertilizes the central cell. To date, plant gamete membrane dynamics during fertilization has been poorly understood. To analyze this unrevealed gamete subcellular behavior, live cell imaging analyses of Arabidopsis double fertilization were performed. We produced female gamete membrane marker lines in which fluorescent proteins conjugated with PIP2a finely visualized egg cell and central cell surfaces. Using those lines together with a sperm cell membrane marker line expressing GCS1-GFP, the double fertilization process was observed. As a result, after gamete fusion, putative sperm plasma membrane GFP signals were occasionally detected on the egg cell surface adjacent to the central cell. In addition, time-lapse imaging revealed that GCS1-GFP signals entered both the egg cell and the central cell in parallel with the sperm cell movement toward the female gametes during double fertilization. These findings suggested that the gamete fusion process based on membrane dynamics was composed of (1) plasma membrane fusion on male and female gamete surfaces, (2) entry of sperm internal membrane components into the female gametes, and (3) plasmogamy.
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Human IgA-binding peptides selected from random peptide libraries: affinity maturation and application in IgA purification.
J. Biol. Chem.
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Phage display system is a powerful tool to design specific ligands for target molecules. Here, we used disulfide-constrained random peptide libraries constructed with the T7 phage display system to isolate peptides specific to human IgA. The binding clones (A1-A4) isolated by biopanning exhibited clear specificity to human IgA, but the synthetic peptide derived from the A2 clone exhibited a low specificity/affinity (K(d) = 1.3 ?m). Therefore, we tried to improve the peptide using a partial randomized phage display library and mutational studies on the synthetic peptides. The designed Opt-1 peptide exhibited a 39-fold higher affinity (K(d) = 33 nm) than the A2 peptide. An Opt-1 peptide-conjugated column was used to purify IgA from human plasma. However, the recovered IgA fraction was contaminated with other proteins, indicating nonspecific binding. To design a peptide with increased binding specificity, we examined the structural features of Opt-1 and the Opt-1-IgA complex using all-atom molecular dynamics simulations with explicit water. The simulation results revealed that the Opt-1 peptide displayed partial helicity in the N-terminal region and possessed a hydrophobic cluster that played a significant role in tight binding with IgA-Fc. However, these hydrophobic residues of Opt-1 may contribute to nonspecific binding with other proteins. To increase binding specificity, we introduced several mutations in the hydrophobic residues of Opt-1. The resultant Opt-3 peptide exhibited high specificity and high binding affinity for IgA, leading to successful isolation of IgA without contamination.
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Inflammatory mass formation caused by gastric ectopic pancreas: report of a case.
Surg. Today
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Ectopic pancreas is a relatively rare condition that only occasionally causes the development of symptoms. This report presents a case of ectopic pancreas presenting as an inflammatory mass that formed in the gastric wall, which was successfully treated by surgical resection. A 32-year-old female was admitted due to a 3-year history of recurrent episodes of upper abdominal pain. Contrast-enhanced computed tomography showed an irregularly enhanced mass of heterogeneous density in the gastric antrum. Gastroscopy revealed a submucosally elevated mass with a central umbilication in the gastric antrum. These studies indicated the presence of a 3-cm ectopic pancreas associated with inflammatory changes. The patient underwent laparoscopic local resection of the stomach. Microscopic examination of the lesion revealed heterogenic pancreatic tissue containing islets, dilated pancreatic ducts, and massive fibrosis in the gastric wall, with acinar atrophy and inflammatory cell infiltration. These findings indicated the formation of an inflammatory mass in the ectopic pancreas.
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Paraesophageal hernia repair.
Ann Thorac Cardiovasc Surg
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Paraesophageal hiatal hernia (PHH), accounting for only 5% of all hiatal hernias, may result in potentially life threatening complications such as obstruction, acute dilatation, perforation, or bleeding of the gastric mucosa. It is traditionally believed that PHH is an indication for surgery. The repair of paraesophageal hernia is technically challenging and controversial. The purpose of this article is to overview the current status of indication of surgery; operative techniques including hernia sac resection, esophageal lengthening procedure, crural repair, and additional antireflux procedure. Results: All symptomatic patients should be surgically treated, when operation is possible. It seems reasonable that asymptomatic or minimally symptomatic patients do not necessarily require surgery and that a more selective approach should be used. The penetration rate is not high, laparoscopic approach is currently the standard care. The hernia sac should be excised and resected circumferentially. Collis-Nissen procedure continues to be the method of choice also in the laparoscopic era, when lengthening procedure of the shortened esophagus is in consideration. Although symptomatic recurrence after suture closure of the crura is uncommon, primary repair is associated with a high rate of anatomic recurrence. Prosthetic mesh repair is reportedly associated with a recurrence rate as low as 5%, at the price of rare but serious complications such as erosion and fibrosis. Although scientific proof is lacking, fundoplication is the most common procedure to be added after crural repair.
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Optimization of ionic conductivity in solid electrolytes through dopant-dependent defect cluster analysis.
Phys Chem Chem Phys
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Atomistic simulation based on an energy minimization technique has been carried out to investigate defect clusters of R(2)O(3) (R = La, Pr, Nd, Sm, Gd, Dy, Y, Yb) solid solutions in fluorite CeO(2). Defect clusters composed of up to six oxygen vacancies and twelve accompanied dopant cations have been simulated and compared. The binding energy of defect clusters increases as a function of the cluster size. A highly symmetric dumbbell structure can be formed by six oxygen vacancies, which is considered as a basic building block for larger defect clusters. This is also believed to be a universal vacancy structure in an oxygen-deficient fluorite lattice. Nevertheless, the accurate positions of associated dopants depend on the dopant radius. As a consequence, the correlation between dopant size and oxygen-ion conductivity has been elucidated based on the ordered defect cluster model. This study sheds light on the choice of dopants from a physical perspective, and suggests the possibility of searching for optimal solid electrolyte materials through atomistic simulations.
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Antioxidant-substituted tetrapyrazinoporphyrazine as a fluorescent sensor for basic anions.
Chem. Commun. (Camb.)
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Tetrapyrazinoporphyrazine substituted at its periphery with eight antioxidant 3,5-di-t-butyl-4-hydroxyphenyl groups behaves as a turn-on fluorescent sensor for fluoride anions. Conversely, the precursor antioxidant-substituted 1,2-phthalonitrile was found to act in turn-off mode suggesting that the origin of the phenomenon lies at the phenolate-substituted 1,4-pyrazinyl moiety.
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[Pancreatic ductal carcinoma concomitant with intraductal papillaly mucinous neoplasm].
Gan To Kagaku Ryoho
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IPMN is a slow-growing tumor and has a good prognosis, but is very often associated with a high incidence of pancreatic ductalcarcinoma(DC). Unlike IPMN, DC progresses rapidly, and has a poor prognosis. However, DC concomitant with IPMN has a better prognosis than DC without IPMN. The reason for the good prognosis of the former is undetermined, but perhaps it is the early detection of DC or its not so malignant behavior. It is important to thoroughly examine the entire pancreas for the potentialco -occurrence of DC in patients with IPMN.
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Synthesis of nitrogen-rich mesoporous carbon nitride with tunable pores, band gaps and nitrogen content from a single aminoguanidine precursor.
ChemSusChem
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Highly ordered mesoporous carbon nitride (CN) with an extremely high nitrogen content and tunable pore diameters was synthesized by using a new precursor with a high nitrogen content, aminoguanidine hydrochloride and mesoporous silica SBA-15 with different pore diameters as hard templates. Surprisingly, the N/C ratio of the prepared mesoporous CN (MCN-4: 1.80) was considerably higher than that of the theoretically predicted C(3)N(4) nanostructures (1.33). This is mainly due to the fact that the CN precursor easily undergoes polymerization at high temperature and affords a highly stable polymer composed of a diamino-s-tetrazine moiety with a six-membered aromatic ring containing six nitrogen atoms that are linked trigonally with the nitrogen atoms. The obtained materials were thoroughly characterized by means of XRD, nitrogen adsorption, high resolution TEM, electron energy loss spectra, high resolution SEM, X-ray photoelectron spectroscopy, FTIR, and C, N, O, and S analysis. The results show that the MCN-4 materials possess a well-ordered mesoporous structure similar to SBA-15 with a high specific surface area and tunable band gap in the range of 2.25-2.49 eV. Interestingly, the pore diameter of the materials can be finely tuned from 3.1-5.8 nm by increasing the pore diameter of the hard-template SBA-15. The reaction temperature plays a critical role for the formation of MCN, and we found that 400 °C is the best condition to obtain MCN-4 with a high nitrogen content. We have further investigated the catalytic application of the MCN-4 materials towards Friedel-Crafts hexanoylation of benzene and compared the results with the mesoporous CN with less nitrogen content (MCN-1) and nonporous CN. Among the materials studied, MCN-4 showed the highest activity, affording a high yield of hexanophenone within a few hours, which is mainly due to the presence of free amine groups on the wall structure of MCN-4.
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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.