1,674 research outputs found
Triply Threaded [4]Rotaxanes
[4]Rotaxanes featuring three axles threaded through a single ring have been prepared through active metal template synthesis. Nickel-catalyzed sp3-sp3 homocouplings of alkyl bromide ‘half threads’ through 37- and 38-membered 2,2':6',2"-terpyridyl macrocycles generates triply-threaded [4]rotaxanes in up to 11 % yield. An analogous 39-membered macrocycle produced no rotaxane products under similar conditions. The constitutions of the [4]rotaxanes were determined by NMR spectroscopy and mass spectrometry. Doubly-threaded [3]rotaxanes were also obtained from the reactions but no [2]rotaxanes were isolated, suggesting that upon demetallation the axle of a singly-threaded rotaxane can slip through a macrocycle that is sufficiently large to accommodate three threads
Proton Induced Pi- Production from 7-Li
This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit
Continuum Pion Production
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
Nonstationary Stochastic Resonance in a Single Neuron-Like System
Stochastic resonance holds much promise for the detection of weak signals in
the presence of relatively loud noise. Following the discovery of nondynamical
and of aperiodic stochastic resonance, it was recently shown that the
phenomenon can manifest itself even in the presence of nonstationary signals.
This was found in a composite system of differentiated trigger mechanisms
mounted in parallel, which suggests that it could be realized in some
elementary neural networks or nonlinear electronic circuits. Here, we find that
even an individual trigger system may be able to detect weak nonstationary
signals using stochastic resonance. The very simple modification to the trigger
mechanism that makes this possible is reminiscent of some aspects of actual
neuron physics. Stochastic resonance may thus become relevant to more types of
biological or electronic systems injected with an ever broader class of
realistic signals.Comment: Plain Latex, 7 figure
Measurements of (p,pi Ì„) Reactions Near Zero Degrees
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
Nieuwe probabilistische methode om overstromingsrisico’s te schatten
Bij onderzoek naar toekomstige overstromingsrisico's worden vaak de resultaten op basis van klimaatsimulaties gepresenteerd en met elkaar vergeleken zonder dat iets gezegd wordt over de kans op veranderingen in het overstromingsrisico. Om zulke kansen te berekenen, is een probabilistische aanpak nodig. In 2010 en 2011 voerden de Vrije Universiteit Amsterdam, het KNMI, Wageningen Universiteit en Deltares het onderzoek 'Aandacht voor Veiligheid 2' uit, dat een demonstratie omvatte van een methode om probabilistische schattingen voor toekomstige overstromingsrisico's te maken. Die methode toont dat het mogelijk is de kans te schatten dat het toekomstige overstromingsrisico groter is dan het huidige overstromingsrisico
Multiple Desmoid Tumors In A Patient With Gardner's Syndrome - Report Of A Case
INTRODUCTION Desmoid tumor (DT) is a common manifestation of Gardner's Syndrome (GS), although it is a rare condition in the general population. DT in patients with GS is usually located in the abdominal wall and/or intra-abdominal cavity. PRESENTATION OF CASE We report a case of a 32 years-old female patient with familial adenomatous polyposis (FAP), who was already submitted to total colectomy and developed multiple DT, located in the abdominal wall and in the left breast. The patient underwent several surgical procedures, with a multidisciplinary team of surgeons. Wide surgical resections of the left breast and the abdominal wall tumors were performed in separate steps. Polypropylene mesh reconstruction and muscle flaps were needed to cover the defects of the thoracic and abdominal walls. After partial necrosis of the adipose-cutaneous flap in the abdomen that required a new skin graft, she had a satisfactory outcome with complete healing of the surgical incisions. DISCUSSION DT is frequent in GS, however, breast localization is very rare, with few cases reported in the literature. Recurrence of DT is not negligible, even after a wide surgical resection. GS patients must be followed up closely, and clinical examination, associated with imaging studies, should be performed to detect any signs of tumor. CONCLUSION DT represents one of the most significant causes of the morbidity and mortality that affects FAP patients following colectomy. In general, the surgical procedures to excise DT are highly complex, requiring a multidisciplinary team. © 2014 The Authors.57370374Lee, B.D., Lee, W., Oh, S.H., A case report of Gardner syndrome with hereditary widespread osteomatous jaw lesions (2009) Oral Surg Oral Med Oral Pathol Oral Radiol Endodontol, 107 (3), pp. 68-72Jonathan, B., Claire, H., Mary, T., Gardner syndrome - Review and report of a case (2005) Oral Oncol Extra, 41, pp. 89-92Fotiadis, C., Tsekouras, D.K., Sfiniadakis, J., Genetzakis, M., Zografos, G.C., Gardner's syndrome: A case report and review of the literature (2005) World Journal of Gastroenterology, 11 (34), pp. 5408-5411Gómez GarcÃa, E.B., Knoers, N.V., Gardner's syndrome (familial adenomatous polyposis): A cilia-related disorder (2009) Lancet Oncol, 10 (7), pp. 727-735Cristofaro, M.G., Giudice, A., Amantea, M., Gardner's syndrome: A clinical and genetic study of a family (2013) Oral Surg Oral Med Oral Pathol Oral Radiol, 115 (3), pp. 1-6Gu, G.L., Wang, S.L., Wei, X.M., Diagnosis and treatment of Gardner syndrome with gastric polyposis: A case report and review of the literature (2008) World J Gastroenterol, 14 (13), pp. 2121-2123(2003) Breast Imaging Reporting and Data System, Breast Imaging Atlas, , American College Of Radiology 4th ed. American College of Radiology Reston, VAMerg, A., Lynch, H.T., Lynch, J.F., Hereditary colon cancer-Part i (2005) Curr Probl Surg, 42 (4), pp. 195-256Mao, C., Huang, Y., Howard, J.M., Carcinoma of the ampulla of Vater and mesenteric fibromatosis (desmoid tumor) associated with Gardner's syndrome: Problems in management (1995) Pancreas, 10 (3), pp. 239-245Cruz-Correa, M., Giardiello, F.M., Familial adenomatous polyposis (2003) Gastrointestinal Endoscopy, 58 (6), pp. 885-894. , DOI 10.1016/S0016-5107(03)02336-8, PII S0016510703023368Juhn, E., Khachemoune, A., Gardner syndrome: Skin manifestations, differential diagnosis and management (2010) Am J Clin Drematol, 11 (2), pp. 117-122Turina, M., Pavlik, C.M., Heinimann, K., Recurrent desmoids determine outcome in patients with Gardner syndrome: A cohort study of three generations of an APC mutation-positive family across 30 years (2013) Int J Colorectal Dis, 28 (6), pp. 865-872Brown, C.S., Jeffrey, B., Korentager, R., Desmoid tumors of the bilateral breasts in a patient without Gardner syndrome: A case report and review of literature (2012) Ann Plast Surg, 69 (2), pp. 220-222Leal, R.F., Silva, P.V.V.T., Ayrizono, M.L.S., Desmoid tumor in patients with familial adenomatous polyposis (2010) Arq Gastroenterol, 47, pp. 373-378Rammohan, A., Wood, J.J., Desmoid tumour of the breast as a manifestation of Gardner's syndrome (2012) Int J Surg Case Rep, 3 (5), pp. 139-142Escobar, C., Munker, R., Thomas, J.O., Update on desmoid tumors (2012) Ann Oncol, 23 (3), pp. 562-569Camargo, V.P., Keohan, M.L., D'Adamo, D.R., Clinical outcomes of systemic therapy for patients with deep fibromatosis (desmoid tumor) (2010) Cancer, 116 (9), pp. 2258-2265Xu, H.M., Han, J.G., Ma, S.Z., Related citations treatment of massive desmoid tumour and abdominal wall reconstructed with meshes in Gardner's Syndrome (2010) J Plast Recontr Aesthet Surg, 63 (6), pp. 1058-106
Impact of the MTHFR C677T polymorphism on one-carbon metabolites: Evidence from a randomised trial of riboflavin supplementation
Homozygosity for the C677T polymorphism in MTHFR (TT genotype) is associated with a 24–87% increased risk of hypertension. Blood pressure (BP) lowering was previously reported in adults with the TT genotype, in response to supplementation with the MTHFR cofactor, riboflavin. Whether the BP phenotype associated with the polymorphism is related to perturbed one-carbon metabolism is unknown. This study investigated one-carbon metabolites and their responsiveness to riboflavin in adults with the TT genotype. Plasma samples from adults (n 115) screened for the MTHFR genotype, who previously participated in RCTs to lower BP, were analysed for methionine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), betaine, choline and cystathionine by liquid chromatography tandem mass spectrometry (LC-MS/MS). The one-carbon metabolite response to riboflavin (1.6 mg/d; n 24) or placebo (n 23) for 16 weeks in adults with the TT genotype was also investigated. Plasma SAM (74.7 ± 21.0 vs 85.2 ± 22.6 nmol/L, P = 0.013) and SAM:SAH ratio (1.66 ± 0.55 vs 1.85 ± 0.51, P = 0.043) were lower and plasma homocysteine was higher (P = 0.043) in TT, compared to CC individuals. In response to riboflavin, SAM (P = 0.008) and cystathionine (P = 0.045) concentrations increased, with no responses in other one-carbon metabolites observed. These findings confirm perturbed one-carbon metabolism in individuals with the MTHFR 677TT genotype, and for the first time demonstrate that SAM, and cystathionine, increase in response to riboflavin supplementation in this genotype group. The genotype-specific, one-carbon metabolite responses to riboflavin intervention observed could offer some insight into the role of this gene-nutrient interaction in blood pressure
The relationship between adiposity and cognitive function in a large community-dwelling population: data from the Trinity Ulster Department of Agriculture (TUDA) ageing cohort study
Riboflavin supplementation alters global and gene-specific DNA methylation in adults with the MTHFR 677 TT genotype
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