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Shencheng Ge, Sergey N Semenov, Amit A Nagarkar, Jonathan Milette, Dionysios C Christodouleas, Li Yuan, George M Whitesides
This work describes the development of Magnetic Levitation (MagLev) to characterize the kinetics of free-radical polymerization of water-insoluble, low-molecular-weight monomers that show a large change in density upon polymerization. Maglev measures density, and certain classes of monomers show a large change in density when monomers covalently join in polymer chains. MagLev characterized both the thermal polymerization of methacrylate-based monomers and the photopolymerization of methyl methacrylate (MMA), and made it possible to determine the orders of reaction and the Arrhenius activation energy of polymerization...
December 6, 2017: Journal of the American Chemical Society
Tomasz Strek, Hubert Jopek, Eligiusz Idczak, Krzysztof W Wojciechowski
This paper presents a finite-element analysis of honeycomb and re-entrant honeycomb structures made of a two-phase composite material which is optimized with respect to selected parameters. It is shown that some distributions of each phase in the composite material result in the counter-intuitive mechanical behaviour of the structures. In particular, negative values of effective Poisson's ratio, i.e., effective auxeticity, can be obtained for a hexagonal honeycomb, whereas re-entrant geometry can be characterized by positive values...
December 4, 2017: Materials
Chao Zhang, Zunfeng Liu, Ying Zheng, Yadi Geng, Chao Han, Yamin Shi, Hongbin Sun, Can Zhang, Yijun Chen, Luyong Zhang, Qinglong Guo, Lei Yang, Xiang Zhou, Lingyi Kong
Mitochondria-mediated apoptosis (MMA) is a preferential option for cancer therapy due to the presence of cell-suicide factors in mitochondria, however, low permeability of mitochondria is a bottleneck for targeting drug delivery. In this paper, glycyrrhetinic acid (GA), a natural product from Glycyrrhiza glabra, is found to be a novel mitochondria targeting ligand, which can improve mitochondrial permeability and enhance the drug uptake of mitochondria. GA-functionalized graphene oxide (GO) is prepared and used as an effective carrier for targeted delivery of doxorubicin into mitochondria...
December 4, 2017: Small
Jae Won Park, Jong Young Lee
Traumatic pseudoaneurysms of middle meningeal artery (MMA) and medial sphenoid wing dural arteriovenous fistula (dAVF) are rare. These lesions usually result from traumatic brain injury, and associated with skull fracture. In this paper, the authors report a case of a patient with a ruptured traumatic pseudoaneurysm of MMA and medial sphenoid wing dAVF presented with an intracerebral hemorrhage in the left temporal region and subarachnoid hemorrhage. These lesions were completely obliterated by endovascular treatment, and the patient was recovered without any neurologic deficit...
October 2017: Korean Journal of Neurotrauma
Ivana Barbosa Suffredini, Mateus Luís Barradas Paciencia, Ingrit E C Díaz, Sergio Alexandre Frana, Maria Martha Bernardi
Background: Anani, (Symphonia globulifera, Clusiaceae), known as chewstick, is a traditional plant occurring in Africa and in Central and South Americas that is used against parasites and microorganisms. Although its use is popular in some of these countries, there is a lack of information related to its influence over behavioral phenotype (BP). Objective: The objective of this study is to evaluate the influence of the administration of the extract obtained from the aerial organs of Anani (EB1257) to male Balb-c mice over BP...
October 2017: Pharmacognosy Magazine
Hifza Rasheed, Paul Kay, Rebecca Slack, Yun Yun Gong
This study was conducted in rural Pakistan to assess the dose-response relationship between skin lesions and arsenic exposure and their variation by demographic characteristics. The study included 398 participants (66 participants with skin lesions and 332 without) residing in six previously unstudied villages exposed to ground water arsenic in the range of <1 to 3090μgL-1. The skin lesions identification process involved interview and physical examinations of participants followed by confirmation by a physician according to UNICEF criteria...
November 29, 2017: Toxicology and Applied Pharmacology
Shaobo Tan, Yanan Zhang, Zhijing Niu, Zhicheng Zhang
The first copper(0) mediated controlled radical polymerization (CRP) of methyl methacrylate (MMA) toward CF bonds onto poly(vinylidene fluoride) (PVDF) is reported with rather high activity. By avoiding the halogen exchange, Cu0 instead of CuI complexes utilized as catalyst is responsible for the significantly improved polymerization activity. Using FH decoupled nuclear magnetic resonance technique, the grafting sites onto PVDF are finely located. From this, detailed topologic information including the grafting density, average length of each side chain, along with the overall grafted content of PMMA, is detected by tracking the polymerization as a function of time...
November 29, 2017: Macromolecular Rapid Communications
J P van Wijngaarden, R A M Dhonukshe-Rutten, E M Brouwer-Brolsma, A W Enneman, K M A Swart, S C van Dijk, P H In 't Veld, N M van Schoor, N van der Velde, R de Jonge, P Lips, A G Uitterlinden, L C P G M de Groot
BACKGROUND: Vitamin B12 status is measured by four plasma/ serum biomarkers: total vitamin B12 (total B12), holotranscobalamin (holoTC), methylmalonic acid (MMA) and homocysteine (tHcy). Associations of B12 intake with holoTC and tHcy and associations between all four biomarkers have not been extensively studied. A better insight in these associations may contribute to an improved differentiation between vitamin B12 deficiency and a normal vitamin B12 status. OBJECTIVE: This study investigates associations between vitamin B12 intake and biomarkers and associations between biomarkers...
2017: Journal of Nutrition, Health & Aging
Young-Seoub Hong, Byeong-Jin Ye, Yu-Mi Kim, Byoung-Gwon Kim, Gyeong-Hui Kang, Jeong-Jin Kim, Ki-Hoon Song, Young-Hun Kim, Jeong-Wook Seo
Recent epidemiological studies have reported adverse health effects, including skin cancer, due to low concentrations of arsenic via drinking water. We conducted a study to assess whether low arsenic contaminated ground water affected health of the residents who consumed it. For precise biomonitoring results, the inorganic (trivalent arsenite (As III) and pentavalent arsenate (As V)) and organic forms (monomethylarsonate (MMA) and dimethylarsinate (DMA)) of arsenic were separately quantified by combining high-performance liquid chromatography and inductively coupled plasma mass spectroscopy from urine samples...
November 27, 2017: International Journal of Environmental Research and Public Health
R S Louro, J A Calasans-Maia, C T Mattos, D Masterson, M D Calasans-Maia, L C Maia
The aim of this study was to evaluate the effect of counterclockwise (CCW) rotation and maxillomandibular advancement (MMA) on the upper airway space using three-dimensional images. An electronic search was performed in the PubMed, Cochrane Library, Scopus, Virtual Health Library, Web of Science, and OpenGrey databases (end date July 2016); a hand-search of primary study reference lists was also conducted. The inclusion criteria encompassed computed tomography evaluations of the upper airway spaces of adult patients undergoing orthognathic surgery with CCW rotation and MMA...
November 25, 2017: International Journal of Oral and Maxillofacial Surgery
Hamid Reza Niknejad, Albert van der Zwan, Sam Heye, Frank Van Calenbergh, Johannes Van Loon
BACKGROUND: Over the past decade, there has been a revival and a renewed interest for cerebrovascular bypass procedures. The superficial temporal artery (STA) has its value as a reliable donor vessel; however, a possible role for the middle meningeal artery (MMA) as a donor artery is still unclear. OBJECTIVE: To assess the feasibility of using the MMA as a donor vessel in cerebrovascular surgery. METHODS: We performed cadaveric dissections on 12 fresh specimens (23 sides) after bilateral silicone injection into the internal and external carotid arteries...
November 22, 2017: Operative Neurosurgery (Hagerstown, Md.)
M Pispili, A Pissiotis, K Michalakis
PURPOSE: To investigate whether the chemical bond between acrylic teeth and heat polymerized PMMA can be altered by chemical and/or mechanical treatment. MATERIALS AND METHODS: One hundred fifty acrylic teeth were divided in groups of 10. Their ridge lap surface underwent mechanical and/or chemical treatments: 1) no treatment, 2) air-abrasion with Al₂O₃ particles, 3) acid etching with phosphoric acid, 4) application of composite resin bonding agent, 5) application of MMA and ethylmethylketone bonding agent, 6) PMMA monomer application...
November 21, 2017: Community Dental Health
Morakot Piemjai, Pareewan Chantarawej, Nobuo Nakabayashi, Franklin Garcia-Godoy
PURPOSE: To visualize the complete protection of restored dentin in the acidic environment by the complete impregnation of resin into demineralized dentin. METHODS: Class V cavities prepared in extracted human molars composed of enamel, cementum and dentin surfaces were sealed using either 4-META/MMA-TBB resin with conditioning periods of 10, 30, 60 seconds with 10% citric acid and 3% ferric chloride mixed aqueous solution (10-3) or Single-Bond 2 adhesives prior to restoration with light-cured resin-composite...
June 2017: American Journal of Dentistry
Fen Yang, Shaowen Xie, Jinxin Liu, Chaoyang Wei, Hongzhi Zhang, Tao Chen, Jing Zhang
Birds are at a higher level in the food chain; however, the potential bioaccumulation and biotransformation of arsenic (As) in birds in As mines has rarely been studied. In this study, four passerine bird species (tree sparrow [Passer montanus], light-vented bulbul [Pycnonotus sinensis], Garrulax canorus [Leucodioptron canorus], and magpie [Pica pica]) were collected from an abandoned As mine in China. The highest recorded As concentrations were 4.95 mg/kg and 51.65 mg/kg in muscles and feathers, respectively...
November 20, 2017: Chemosphere
Mattijs Out, Adriaan Kooy, Philippe Lehert, Casper A Schalkwijk, Coen D A Stehouwer
AIMS: Metformin treatment is associated with a decrease of serum vitamin B12, but whether this reflects tissue B12 deficiency is controversial. We studied the effects of metformin on serum levels of methylmalonic acid (MMA), a biomarker for tissue B12 deficiency, and on onset or progression of neuropathy. METHODS: In the HOME trial, 390 insulin-treated patients with type 2 diabetes were treated with metformin or placebo for 52months. In a post hoc analysis, we analyzed the association between metformin, MMA and a validated Neuropathy Score (NPS)...
November 8, 2017: Journal of Diabetes and its Complications
Mesha Martinez, Paola Pergami, Jonathan Murnick, Monica S Pearl
Traumatic arteriovenous fistulas (AVFs) involving the middle meningeal artery (MMA) are uncommon lesions and rare in the pediatric population. An adolescent with headaches developed a bruit and a rhythmic "swooshing" noise in the left ear 9 weeks after a traumatic brain injury involving a left temporal bone fracture. An MRA of the brain demonstrated an enlarged left MMA and arterialized flow in the left middle meningeal vein (MMV), suggestive of an AVF. Cerebral angiography confirmed and characterized the left MMA-MMV fistula, which drained into the pterygoid plexus...
November 23, 2017: Child's Nervous System: ChNS: Official Journal of the International Society for Pediatric Neurosurgery
Dapeng Wang, Yasuyo Shimoda, Sanxiang Wang, Zhenghui Wang, Jian Liu, Xing Liu, Huanyu Jin, Fenfang Gao, Jian Tong, Kenzo Yamanaka, Jie Zhang, Yan An
BACKGROUND: It is generally acknowledged that the determination of harmful chemical compounds excreted into saliva is useful for assessing their exposure levels. The aim of the present study was to compare the total arsenic and its species in saliva and urine samples collected from the people residing in an arsenic-contaminated area of China and to further verify the feasibility of using salivary arsenic as a new biomarker of arsenic exposure. METHODS: Total arsenic and speciation analyses in urine and saliva samples among 70 residents exposed to arsenic from drinking water in Shanxi, China were carried out by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP/MS)...
May 11, 2017: Environmental Health and Preventive Medicine
Alice Pannérec, Eugenia Migliavacca, Antonio De Castro, Joris Michaud, Sonia Karaz, Laurence Goulet, Serge Rezzi, Tze Pin Ng, Nabil Bosco, Anis Larbi, Jerome N Feige
BACKGROUND: Physical frailty and loss of mobility in elderly individuals lead to reduced independence, quality of life, and increased mortality. Vitamin B12 deficiency has been linked to several age-related chronic diseases, including in the musculo-skeletal system, where vitamin B12 deficiency is generally believed to be linked to poor nutritional intake. In the present study, we asked whether aging and frailty associate with altered vitamin B12 homeostasis in humans and investigated the underlying molecular mechanisms using preclinical models...
November 21, 2017: Journal of Cachexia, Sarcopenia and Muscle
Inusha Panigrahi, Savita Bhunwal, Harish Varma, Simranjeet Singh
A 5-year-old boy presented with recurrent episodes of fever, feeding problems, lethargy, from the age of 11 months, and poor weight gain. He was admitted and evaluated for metabolic causes and diagnosed as having methylmalonic acidemia (MMA). He was treated with vit B12 and carnitine supplements and has been on follow-up for the last 3 years. Mutation analysis by next generation sequencing (NGS), supplemented with Sanger sequencing, revealed two novel variants in the MUT gene responsible for MMA in exon 5 and exon 3, respectively...
2017: Case Reports in Genetics
Megan K McDonald, Julie-Anne Fritz, Dongxin Jia, Deborah Scheuchner, Floyd F Snyder, Avalyn Stanislaus, Jared Curle, Liang Li, Sally P Stabler, Robert H Allen, Paul E Mains, Roy A Gravel
Vitamin B12 (cobalamin, Cbl) is a micronutrient essential to human health. Cbl is not utilized as is but must go through complex subcellular and metabolic processing to generate two cofactor forms: methyl-Cbl for methionine synthase, a cytosolic enzyme; and adenosyl-Cbl for methylmalonyl-CoA mutase, a mitochondrial enzyme. Some 10-12 human genes have been identified responsible for the intracellular conversion of Cbl to cofactor forms, including genes that code for ATP-binding cassette (ABC) transporters acting at the lysosomal and plasma membranes...
November 11, 2017: Molecular Genetics and Metabolism
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