1,459 research outputs found
Tau functions as Widom constants
We define a tau function for a generic Riemann-Hilbert problem posed on a
union of non-intersecting smooth closed curves with jump matrices analytic in
their neighborhood. The tau function depends on parameters of the jumps and is
expressed as the Fredholm determinant of an integral operator with block
integrable kernel constructed in terms of elementary parametrices. Its
logarithmic derivatives with respect to parameters are given by contour
integrals involving these parametrices and the solution of the Riemann-Hilbert
problem. In the case of one circle, the tau function coincides with Widom's
determinant arising in the asymptotics of block Toeplitz matrices. Our
construction gives the Jimbo-Miwa-Ueno tau function for Riemann-Hilbert
problems of isomonodromic origin (Painlev\'e VI, V, III, Garnier system, etc)
and the Sato-Segal-Wilson tau function for integrable hierarchies such as
Gelfand-Dickey and Drinfeld-Sokolov.Comment: 26 pages, 6 figure
Reconstructive challenge of dermatofibrosarcoma protuberans in the female breast
Dermatofibrosarcoma protuberans is an uncommon locally aggressive malignant neoplasm that most frequently appears in the trunk, followed by the extremities, head, and neck. But occurrence in the breast is extremely rare. We present a case of a 28-year-old woman, who had a history of trauma 5 years previously and excision 1 year before presentation at our clinic. We performed wide excision, together with microscopic and immunohistochemical analysis. No postoperative oncologic treatment was used and she remains disease-free 1 year after the surgery without any tumor recurrence. Here, we report a case of dermatofibrosarcoma protuberans in the female breast and present a detailed discussion of the diagnosis and treatment with reference to available literatures
Use of serum squamous cell carcinoma antigen for follow-up monitoring of cervical cancer patients who were treated by concurrent chemoradiotherapy
Design, Analysis and Empirical Researches for Solar Heat Collecting System based on Flat Mirrors Combination
There has been a dramatic increase of research on energy production using solar energy. This research aims to examine development of concentrating solar collector that is related to mid-high solar energy field. Although the use of dish type solar thermal system has been common in the existing high-efficiency collector technology, several problems have been raised. In order to solve these issues, the frame has been designed as flat plate type with Fresnel lens and the structural stability has been proved by analysis. Furthermore, the experiment that checks collectorrsquos temperature has been performed for the correct works of the stirling engine
Tau positron emission tomography in tauopathies: A narrative review
Aggregation of misfolded tau in the brain is a major pathological feature common in various neurodegenerative disorders known as tauopathies, including Alzheimerās disease, progressive supranuclear palsy, corticobasal syndrome, and dementia with Lewy bodies. Tauopathies are collection of diseases with varied overlapping symptoms and complicated manifestations. Consequently, it is crucial to be able to assess tau deposits in vivo. Over the past decade, tau-specific radioligands for positron emission tomography (PET) have been developed and tested, including first-generation compounds (e.g., 18F-THK5317, 18F-THK5351, 18F-AV1451, and 11C-PBB3) and second-generation compounds (18F-MK-6240, 18F-RO-948, and 18F-PI-2620). With the recent advances of tau PET tracers, assessing the pattern of tau deposition in vivo is possible. These methods will allow accurate diagnosis of tauopathies and monitoring of disease progression. In this mini review, we summarize current findings from studies using tau PET tracers regarding neuropathological characteristics, clinical implications, and potential applications of tau PET. We also discuss methodological considerations for appropriate use of these technologies and discuss what has been learned from these findings
Recognition of the microbiota by Nod2 contributes to the oral adjuvant activity of cholera toxin through the induction of interleukin-1ĆĀ²
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152023/1/imm13105_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152023/2/imm13105.pd
Pectinase-treated Panax ginseng ameliorates hydrogen peroxide-induced oxidative stress in GC-2 sperm cells andĀ modulatesĀ testicular gene expression in aged rats
AbstractBackgroundTo investigate the effect of pectinase-treated Panax ginseng (GINST) in cellular and male subfertility animal models.MethodsHydrogen peroxide (H2O2)-induced mouse spermatocyte GC-2spd cells were used as an inĀ vitro model. Cell viability was measured using MTT assay. For the inĀ vivo study, GINST (200Ā mg/kg) mixed with a regular pellet diet was administered orally for 4 mo, and the changes in the mRNA and protein expression level of antioxidative and spermatogenic genes in young and aged control rats were compared using real-time reverse transcription polymerase chain reaction and western blotting.ResultsGINST treatment (50Ā Ī¼g/mL, 100Ā Ī¼g/mL, and 200Ā Ī¼g/mL) significantly (pĀ <Ā 0.05) inhibited the H2O2-induced (200 Ī¼M) cytotoxicity in GC-2spd cells. Furthermore, GINST (50Ā Ī¼g/mL and 100Ā Ī¼g/mL) significantly (pĀ <Ā 0.05) ameliorated the H2O2-induced decrease in the expression level of antioxidant enzymes (peroxiredoxin 3 and 4, glutathione S-transferase m5, and glutathione peroxidase 4), spermatogenesis-related protein such as inhibin-Ī±, and specific sex hormone receptors (androgen receptor, luteinizing hormone receptor, and follicle-stimulating hormone receptor) in GC-2spd cells. Similarly, the altered expression level of the above mentioned genes and of spermatogenesis-related nectin-2 and cAMP response element-binding protein in aged rat testes was ameliorated with GINST (200Ā mg/kg) treatment. Taken together, GINST attenuated H2O2-induced oxidative stress in GC-2 cells and modulated the expression of antioxidant-related genes and of spermatogenic-related proteins and sex hormone receptors in aged rats.ConclusionGINST may be a potential natural agent for the protection against or treatment of oxidative stress-induced male subfertility and aging-induced male subfertility
Activation of Protein Kinase G After Repeated Cocaine Administration Is Necessary for the Phosphorylation of Ī±-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid Receptor GluA1 at Serine 831 in the Rat Nucleus Accumbens
Phosphorylation of Ī±-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the striatum plays a crucial role in regulating the receptor-coupled signaling cascades leading to behavioral changes associated with psychostimulant exposure. The present study determined if activation of protein kinase G (PKG) contributes to the phosphorylation of AMPA receptor GluA1 subunit at the position of serine 831 (GluA1-S831) in the rat nucleus accumbens (NAc) after repeated cocaine administration. The results demonstrated that repeated intraperitoneal (i.p.) injections of cocaine (20 mg/kg) once a day for seven consecutive days significantly increased the level of phosphorylated (p)GluA1-S831. This increase was decreased by the intra-NAc infusion of either the cyclic guanosine monophosphate (cGMP) analog, Rp-8-Br-PET-cGMPS (5 nmol/1 Ī¼L), or the PKG inhibitor, KT5823 (2 nmol/1 Ī¼L). Repeated cocaine administration increased PKG binding activity to GluA1. This increase in GluA1-S831 phosphorylation after repeated cocaine administration was decreased by the intra-NAc infusion of the synthetic peptide (Tat-tagged interfering peptide (Tat-GluA1-i)), that interferes with the binding of PKG to GluA1. Intra-NAc infusion of the interfering peptide also reduced the repeated cocaine-induced increase in locomotor activity. These findings suggest that activated PKG, after repeated exposure to cocaine, binds to AMPA receptor GluA1 and is required for the phosphorylation of S831, contributing to behavioral changes
Visceral Myopathy of Intestinal Pseudoobstruction
Intestinal pseudoobstruction is a syndrome complex caused by a variety
of disorders of various etiology. It can be classified pathologically as visceral myopathy
and visceral neuropathy. The sporadic form of visceral myopathy is characterized
histologically by vacuolar degeneration and fibrosis of smooth muscle but differs from
the familial form only by the absence of other affected family members. We studied 6
cases with intestinal pseudoobstruction classified as sporadic visceral myopathy. They
were four boys and two girls, and were two neonates, two infants and two children. The
duration of symptoms ranged from two days to two years. Two babies were dead from
pneumonia and sepsis. Others were alleviated after surgical resection of the bowel.
Both small and large intestines were found affected in autopsy cases. Histopathologic
features were vacuolar degeneration of muscularis propria, disproportionate hypoplasia
of outer muscle layer, abnormal muscle direction of muscularis propria, submucosal
and/or interstitial fibrosis and extra muscle layering. It is presumed that a variety of
histopathologic features accounts for visceral myopathy of intestinal pseudoobstruction
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