245 research outputs found

    A note on group rings of p-groups

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    Genetic Diversity and Differentiation of the Ryukyu Endemic Frog Babina holsti as Revealed by Mitochondrial DNA

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    We surveyed the genetic diversity and genetic differentiation of an endangered frog, Babina holsti, endemic to Okinawajima and Tokashikijima Islands of the Ryukyus, to elucidate its divergence history and obtain basic data for its conservation. Genetic differentiation between the two island lineages is moderate (3. 1% p-distance in the cyt b gene). This result suggests that the two island lineages have been isolated between the late Pliocene and the middle Pleistocene and have never migrated between the current northern part of Okinawajima and Tokashikijima Islands, which were once connected in the late Pleistocene glacial age. On Okinawajima Island, the southernmost sample was constituted by a unique haplotype, without considerable genetic distance from haplotypes detected from northern samples. This unique haplotype composition in the southernmost sample would have resulted from the restricted gene flow between the southernmost population and the other populations in Okinawajima Island. Furthermore, the absence of genetic diversity within the southernmost sample indicates that this population has recently experienced population size reduction, possibly by predation pressure from an introduced mongoose, which is more abundant in the southern part than in the northern part of the island. Lower genetic diversity in the Tokashikijima sample implies a small effective population size for mitochondrial DNA (mtDNA) in B. holsti on the island. Immediate conservation measures should be taken for the populations from the southernmost range in Okinawajima and Tokashikijima

    Heating-free, room-temperature operation of a radiofrequency-to-light signal transducer with a membrane oscillator and a built-in metasurface mirror

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    We present an electro-mechano-optical radiofrequency (rf)-to-light signal transducer robust against laser heating and thus operational at room temperature. A metal-free, low-loss metasurface mirror and an aluminum electrode made separately on a Si₃N₄ membrane oscillator comprise a chain of electro-mechanical and opto-mechanical systems, mediating electrical and optical signals through the (2, 2)-mode characteristic oscillation. We demonstrate up-conversion of rf signals at 175.2 MHz by 6 orders of magnitude in frequency to an optical regime with the transfer efficiency of 2.3 × 10⁻⁹, also showing stable operation due to reduced laser heating of the mirror

    Algebraic extensions of simple rings I

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    Induction of cyclooxygenase-2 in human synovial cells by β2-microglobulin

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    Induction of cyclooxygenase-2 in human synovial cells by β2-microglobulin.BackgroundProstaglandins (PGs) are important mediators of inflammation in arthritis. We evaluated the role of the cyclooxygenase-2 (COX-2) enzyme, which regulates PG biosynthesis, in osteoarthropathy associated with hemodialysis-associated amyloidosis (HAA) by characterizing COX-2 expression in β2-microglobulin–treated human synovial cells.MethodsWe examined the effects of β2-microglobulin (β2m), a major constituent protein of amyloid fibrils in HAA, on the COX-2 protein and mRNA expression in human synovial cells using Western blot and reverse transcriptase-polymerase chain reaction.Resultsβ2m selectively increased the biosynthesis of COX-2 protein and induction of COX-2 mRNA in a dose-dependent manner. Immunoabsorption of β2m–containing media by anti-β2m–specific antibody abrogated β2m–mediated COX-2 expression on synovial cells. On the other hand, dexamethasone markedly suppressed the induction of COX-2 protein and mRNA in β2m–stimulated synovial cells.ConclusionsOur results suggest that induction of COX-2 expression by β2m may be an important component of the inflammatory process in hemodialysis-associated osteoarthropathy

    Epidermal growth factor signals regulate dihydropyrimidine dehydrogenase expression in EGFR-mutated non-small-cell lung cancer

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    Schematic diagrams of the signal cascade of EGF-induced DPD expression of EGFR-mutated type cells. TF, transcription factor; Mit A, mithramycin A. (JPG 130 kb

    Pancreatic Duct-to-mucosa versus Invagination or Complete External Drainage Anastomosis in Case of Small Pancreatic Duct after Pancreaticoduodenectomy: Comparative Historical Review

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    After pancreaticoduodenectomy (PD), pancreatic duct-to-mucosa anastomosis (PDM) has been usually applied which may prevent risk of pancreatic fistula (PF). In cases with a small pancreatic duct, however, PDM is difficult to complete. Procedures involving the invagination (IV) or complete external tube drainage (CED) are supposed to be alternative options for anastomosis. We retrospectively compared clinical results between PDM and IV or CED in 104 patients with a tiny pancreatic duct who underwent PD. The 77 patients undergoing PDM (the control group) and 27 patients undergoing other procedures, including 19 for CED and 8 for IV, were comparatively examined. Fatty pancreas was commonly observed in CED group. Pancreaticojejunostomy was significantly more frequently applied in CED group, and the operating time in the IV group was significantly longer than in control group (p<0.05). The anastomotic time in CED group tended to be shorter than those in control and IV groups (18 versus 29 and 37 min). The incidences of PF were not significantly different among groups (31% in control, 47% inCED and 14% in IV, respectively); however, a grade B or C level of PF was not observed in the IV group. PDM is often difficult to achieve and inadequate suturing may injure the pancreatic parenchyma in cases of very small pancreatic duct. Re-evaluation of the CED or IV procedure as an alternative option was suggested to be warranted

    Successful Colectomy for Hemorrhagic Colitis with Hemolytic Uremic Syndrome and Acute Encephalopathy due to Escherichia coli O157 Infection

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    An 81-year-old man was admitted to a primary care hospital due to bloody diarrhea. The findings of abdominal computed tomography indicated ischemic colitis, so conservative therapy was started. On the 4th hospital day, the patient was transferred to our hospital because of renal dysfunction. Physical examination showed clouding of consciousness and abdominal distention. Abdominal computed tomography revealed massive ascites and thickening of the whole colonic wall. With a diagnosis of acute abdomen, an emergent laparotomy was performed. Extended right hemicolectomy was performed because of severe ischemic change and necrosis of the right side of the colon. In the stool culture before the operation, Escherichia coli O157 and verotoxin were found, so this case was diagnosed as hemorrhagic colitis with hemolytic uremic syndrome and acute encephalopathy due to Escherichia coli O157 infection. Postoperatively, the hemolytic uremic syndrome and acute encephalopathy were prolonged. However, with intensive care, the patient recovered and was discharged on the 33rd postoperative day

    Clinical Efficacy and Safety of Sitafloxacin 200 mg Once Daily for Refractory Genitourinary Tract Infections

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    The aim of this ongoing trial is to evaluate the clinical efficacy and safety of sitafloxacin (STFX) 200 mg once daily (QD) for 7 days in patients with refractory genitourinary tract infections, which include recurrent or complicated cystitis, complicated pyelonephritis, bacterial prostatitis, and epididymitis. The primary endpoint is the microbiological efficacy at 5-9 days after the last administration of STFX. Recruitment began in February 2021, and the target total sample size is 92 participants
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