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https://www.readbyqxmd.com/read/27903405/separation-of-44-ti-from-proton-irradiated-scandium-by-using-solid-phase-extraction-chromatography-and-design-of-44-ti-44-sc-generator-system
#1
V Radchenko, C A L Meyer, J W Engle, C M Naranjo, G A Unc, T Mastren, M Brugh, E R Birnbaum, K D John, F M Nortier, M E Fassbender
Scandium-44g (half-life 3.97h [1]) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, (18)F, due to its favorable decay parameters. One source of (44g)Sc is the long-lived parent nuclide (44)Ti (half-life 60.0 a). A (44)Ti/(44g)Sc generator would have the ability to provide radionuclidically pure (44g)Sc on a daily basis. The production of (44)Ti via the (45)Sc(p,2n) reaction requires high proton beam currents and long irradiation times...
November 24, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27901014/stacked-antiaromatic-porphyrins
#2
Ryo Nozawa, Hiroko Tanaka, Won-Young Cha, Yongseok Hong, Ichiro Hisaki, Soji Shimizu, Ji-Young Shin, Tim Kowalczyk, Stephan Irle, Dongho Kim, Hiroshi Shinokubo
Aromaticity is a key concept in organic chemistry. Even though this concept has already been theoretically extrapolated to three dimensions, it usually still remains restricted to planar molecules in organic chemistry textbooks. Stacking of antiaromatic π-systems has been proposed to induce three-dimensional aromaticity as a result of strong frontier orbital interactions. However, experimental evidence to support this prediction still remains elusive so far. Here we report that close stacking of antiaromatic porphyrins diminishes their inherent antiaromaticity in the solid state as well as in solution...
November 30, 2016: Nature Communications
https://www.readbyqxmd.com/read/27900386/all-or-none-switching-of-photon-upconversion-in-self-assembled-organogel-systems
#3
Pengfei Duan, Deepak Asthana, Takuya Nakashima, Tsuyoshi Kawai, Nobuhiro Yanai, Nobuo Kimizuka
Aggregation-induced photon upconversion (iPUC) based on a triplet-triplet annihilation (TTA) process is successfully developed via controlled self-assembly of donor-acceptor pairs in organogel nanoassemblies. Although segregation of donor from acceptor assemblies has been an outstanding problem in TTA-based UC and iPUC, we resolved this issue by modifying both the triplet donor and aggregation induced emission (AIE)-type acceptor with glutamate-based self-assembling moieties. These donors and acceptors co-assemble to form organogels without segregation...
November 30, 2016: Faraday Discussions
https://www.readbyqxmd.com/read/27897180/quantifying-electronic-band-interactions-in-van-der-waals-materials-using-angle-resolved-reflected-electron-spectroscopy
#4
Johannes Jobst, Alexander J H van der Torren, Eugene E Krasovskii, Jesse Balgley, Cory R Dean, Rudolf M Tromp, Sense Jan van der Molen
High electron mobility is one of graphene's key properties, exploited for applications and fundamental research alike. Highest mobility values are found in heterostructures of graphene and hexagonal boron nitride, which consequently are widely used. However, surprisingly little is known about the interaction between the electronic states of these layered systems. Rather pragmatically, it is assumed that these do not couple significantly. Here we study the unoccupied band structure of graphite, boron nitride and their heterostructures using angle-resolved reflected-electron spectroscopy...
November 29, 2016: Nature Communications
https://www.readbyqxmd.com/read/27896699/cationized-carbohydrate-gas-phase-fragmentation-chemistry
#5
Benjamin J Bythell, Maha T Abutokaikah, Ashley R Wagoner, Shanshan Guan, Jordan M Rabus
We investigate the fragmentation chemistry of cationized carbohydrates using a combination of tandem mass spectrometry, regioselective labeling, and computational methods. Our model system is D-lactose. Barriers to the fundamental glyosidic bond cleavage reactions, neutral loss pathways, and structurally informative cross-ring cleavages are investigated. The most energetically favorable conformations of cationized D-lactose were found to be similar. In agreement with the literature, larger group I cations result in structures with increased cation coordination number which require greater collision energy to dissociate...
November 28, 2016: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/27896656/pancreatitis-after-pancreatoduodenectomy-predicts-clinically-relevant-postoperative-pancreatic-fistula
#6
C M Kühlbrey, N Samiei, O Sick, F Makowiec, U T Hopt, U A Wittel
BACKGROUND: Morbidity after pancreas resection is still high with postoperative pancreatic fistulas (POPF) being the most frequent complication. However, exocrine insufficiency seems to protect from POPF. In clinical practice, patients showing increased postoperative systemic amylase concentrations appear to frequently develop POPF. We therefore retrospectively examined the occurrence of systemic amylase increase after pancreas resections and its association with the clinical course. PATIENTS AND METHODS: Perioperative data from 739 consecutive pancreas resections were assessed in a prospectively maintained SPSS database...
November 28, 2016: Journal of Gastrointestinal Surgery: Official Journal of the Society for Surgery of the Alimentary Tract
https://www.readbyqxmd.com/read/27896476/medicinal-chemistry-of-the-noncanonical-cyclic-nucleotides-ccmp-and-cump
#7
Frank Schwede, Andreas Rentsch, Hans-Gottfried Genieser
After decades of intensive research on adenosine-3',5'-cyclic monophosphate (cAMP)- and guanosine-3',5'-cyclic monophosphate (cGMP)-related second messenger systems, also the noncanonical congeners cyclic cytidine-3',5'-monophosphate (cCMP) and cyclic uridine-3',5'-monophosphate (cUMP) gained more and more interest. Until the late 1980s, only a small number of cCMP and cUMP analogs with sometimes undefined purities had been described. Moreover, most of these compounds had been rather synthesized as precursors of antitumor and antiviral nucleoside-5'-monophosphates and hence had not been tested for any second messenger activity...
November 29, 2016: Handbook of Experimental Pharmacology
https://www.readbyqxmd.com/read/27895705/improved-sugar-yields-from-biomass-sorghum-feedstocks-comparing-low-lignin-mutants-and-pretreatment-chemistries
#8
Bruno Godin, Nick Nagle, Scott Sattler, Richard Agneessens, Jérôme Delcarte, Edward Wolfrum
BACKGROUND: For biofuel production processes to be economically efficient, it is essential to maximize the production of monomeric carbohydrates from the structural carbohydrates of feedstocks. One strategy for maximizing carbohydrate production is to identify less recalcitrant feedstock cultivars by performing some type of experimental screening on a large and diverse set of candidate materials, or by identifying genetic modifications (random or directed mutations or transgenic plants) that provide decreased recalcitrance...
2016: Biotechnology for Biofuels
https://www.readbyqxmd.com/read/27893646/acute-right-heart-failure-after-hemorrhagic-shock-and-trauma-pneumonectomy-a-management-approach-a-blinded-randomized-controlled-animal-trial-using-inhaled-nitric-oxide
#9
Andrea L Lubitz, Lars O Sjoholm, Amy Goldberg, Abhijit Pathak, Thomas Santora, Thomas E Sharp, Markus Wallner, Remus M Berretta, Lauren A Poole, Jichuan Wu, Marla R Wolfson
BACKGROUND: Hemorrhagic shock and pneumonectomy causes an acute increase in pulmonary vascular resistance (PVR). The increase in PVR and right ventricular (RV) afterload leads to acute RV failure, thus reducing left ventricular (LV) preload and output. iNO lowers PVR by relaxing pulmonary arterial smooth muscle without remarkable systemic vascular effects. We hypothesized that with hemorrhagic shock and pneumonectomy, iNO can be used to decrease PVR and mitigate right heart failure. METHODS: A hemorrhagic shock and pneumonectomy model was developed using sheep...
November 23, 2016: Journal of Trauma and Acute Care Surgery
https://www.readbyqxmd.com/read/27892593/dual-mode-refractive-index-and-charge-sensing-to-investigate-complex-surface-chemistry-on-nanostructures
#10
Nikhil Bhalla, Doojin Lee, Shivani Sathish, Amy Q Shen
This work presents a novel dual-mode charge and refractive index sensitive device integrated with nanoplasmonic islands, for the first time, on insulator-semiconductor junctions. The developed nano-metal-insulator semiconductor (nMIS) sensor facilitates simultaneous detection of charge and mass changes on the nanoislands due to the binding of biomolecules. The charging of the nanoislands is traced by using the capacitive field-effect electrolyte-metal-insulator-semiconductor structure and the refractive index changes are quantified by measuring the change in the localized surface plasmon resonances of the nanoislands...
November 28, 2016: Nanoscale
https://www.readbyqxmd.com/read/27890378/design-and-synthesis-of-4-5-6-7-tetrahydro-1h-1-2-diazepin-7-one-derivatives-as-a-new-series-of-phosphodiesterase-4-pde4-inhibitors
#11
Sara Guariento, Anna Karawajczyk, James A Bull, Gessica Marchini, Martyna Bielska, Xenia Iwanowa, Olga Bruno, Paola Fossa, Fabrizio Giordanetto
Phosphodiesterase 4 (PDE4) inhibitors have attractive therapeutic potential in respiratory, inflammatory, metabolic and CNS disorders. The present work details the design, chemical exploration and biological profile of a novel PDE4 inhibitor chemotype. A diazepinone ring was identified as an under-represented heterocyclic system fulfilling a set of PDE4 structure-based design hypotheses. Rapid exploration of the structure activity relationships for the series was enabled by robust and scalable two/three-steps parallel chemistry protocols...
November 16, 2016: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/27889417/dietary-zinc-and-incident-calcium-kidney-stones-in-adolescence
#12
Gregory E Tasian, Michelle E Ross, Lihai Song, Robert W Grundmeier, James Massey, Michelle R Denburg, Lawrence Copelovitch, Steven Warner, Thomas Chi, David W Killilea, Marshall L Stoller, Susan L Furth
PURPOSE: To determine the association between dietary zinc intake and incident calcium kidney stones and examine the relationship between dietary zinc intake and urinary zinc excretion among adolescents. MATERIAL AND METHODS: This study was a nested case-control study conducted within a large pediatric healthcare system. Three 24-hour dietary recalls and spot urine chemistries were obtained for 30 participants aged 12-18 years with a first idiopathic calcium-based kidney stone and 30 healthy controls, matched on age, sex, race, and month of enrollment...
November 23, 2016: Journal of Urology
https://www.readbyqxmd.com/read/27889241/natural-and-synthetic-coral-biomineralization-for-human-bone-revitalization
#13
REVIEW
David W Green, Besim Ben-Nissan, Kyung Sik Yoon, Bruce Milthorpe, Han-Sung Jung
Coral skeletons can regenerate replacement human bone in nonload-bearing excavated skeletal locations. A combination of multiscale, interconnected pores and channels and highly bioactive surface chemistry has established corals as an important alternative to using healthy host bone replacements. Here, we highlight how coral skeletal systems are being remolded into new calcified structures or synthetic corals by biomimetic processes, as places for the organized permeation of bone tissue cells and blood vessels...
November 23, 2016: Trends in Biotechnology
https://www.readbyqxmd.com/read/27889115/new-psychoactive-substances-are-there-any-good-options-for-regulating-new-psychoactive-substances
#14
Peter Reuter, Bryce Pardo
Advances in chemistry, technology, and globalization have contributed to the rapid development and diffusion of NPS (new psychoactive substances), creating perhaps the most serious challenge to the century-old international drug control system and to national systems. Very little is known about the effects of these substances which fall outside of national and international controls. The predominant response to the flood of NPS has been the development of more expeditious methods of prohibiting a new chemical entity...
November 23, 2016: International Journal on Drug Policy
https://www.readbyqxmd.com/read/27886246/disorder-and-dephasing-as-control-knobs-for-light-transport-in-optical-fiber-cavity-networks
#15
Silvia Viciani, Stefano Gherardini, Manuela Lima, Marco Bellini, Filippo Caruso
Transport phenomena represent a very interdisciplinary topic with applications in many fields of science, such as physics, chemistry, and biology. In this context, the possibility to design a perfectly controllable experimental setup, where to tune and optimize its dynamics parameters, is a challenging but very relevant task to emulate, for instance, the transmission of energy in light harvesting processes. Here, we experimentally build a scalable and controllable transport emulator based on optical fiber cavity networks where the system noise parameters can be finely tuned while maximizing the transfer efficiency...
November 25, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27885032/directed-evolution-of-cytochrome-c-for-carbon-silicon-bond-formation-bringing-silicon-to-life
#16
S B Jennifer Kan, Russell D Lewis, Kai Chen, Frances H Arnold
Enzymes that catalyze carbon-silicon bond formation are unknown in nature, despite the natural abundance of both elements. Such enzymes would expand the catalytic repertoire of biology, enabling living systems to access chemical space previously only open to synthetic chemistry. We have discovered that heme proteins catalyze the formation of organosilicon compounds under physiological conditions via carbene insertion into silicon-hydrogen bonds. The reaction proceeds both in vitro and in vivo, accommodating a broad range of substrates with high chemo- and enantioselectivity...
November 25, 2016: Science
https://www.readbyqxmd.com/read/27883932/biological-response-of-human-suture-mesenchymal-cells-to-titania-nanotube-based-implants-for-advanced-craniosynostosis-therapy
#17
Manpreet Bariana, Prem Dwivedi, Sarbin Ranjitkar, John A Kaidonis, Dusan Losic, Peter J Anderson
Titania nanotubes (TNTs) engineered on titanium (Ti) surfaces (i.e. TNT/Ti) and loaded with specific drugs have been recognised as a promising solution for localised therapeutic delivery to address several medical problems not feasible with conventional drug administration. We propose the use of TNT/Ti protein-releasing implants to treat paediatric craniofacial abnormality in craniosynostosis caused by premature fusion of cranial sutures. In this study, we have analysed the biological response of human suture mesenchymal cells (SMCs), extracted from two different patients undergoing craniofacial reconstruction surgery, at the TNT/Ti implant surface...
November 17, 2016: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/27881667/a-mechanistic-physicochemical-model-of-carbon-dioxide-transport-in-blood
#18
David Patrick O'Neill, Peter A Robbins
A number of mathematical models have been produced that, given the Pco2 and Po2 of blood, will calculate the total concentrations for CO2 and O2 in blood. However, all these models contain at least some empirical features, and thus do not represent all of the underlying physicochemical processes in an entirely mechanistic manner. The aim of this study was to develop a physicochemical model of CO2 carriage by the blood to determine whether our understanding of the physical chemistry of the major chemical components of blood together with their interactions is sufficiently strong to predict the physiological properties of CO2 carriage by whole blood...
November 23, 2016: Journal of Applied Physiology
https://www.readbyqxmd.com/read/27879111/modelling-chemistry-and-biology-after-implantation-of-a-drug-eluting-stent-part-i-drug-transport
#19
Tuoi Vo, William Lee, Adam Peddle, Martin Meere
Drug-eluting stents have been used widely to prevent restenosis of arteries following percutaneous balloon angioplasty. Mathematical modelling plays an important role in optimising the design of these stents to maximise their efficiency. When designing a drug-eluting stent system, we expect to have a sufficient amount of drug being released into the artery wall for a sufficient period to prevent restenosis. In this paper, a simple model is considered to provide an elementary description of drug release into artery tissue from an implanted stent...
April 1, 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/27879021/click-and-release-a-chemical-strategy-toward-developing-gasotransmitter-prodrugs-by-using-an-intramolecular-diels-alder-reaction
#20
Xingyue Ji, Cheng Zhou, Kaili Ji, Robert E Aghoghovbia, Zhixiang Pan, Vayou Chittavong, Bowen Ke, Binghe Wang
Prodrug strategies have been proven to be a very effective way of addressing delivery problems. Much of the chemistry in prodrug development relies on the ability to mask an appropriate functional group, which can be removed under appropriate conditions. However, developing organic prodrugs of gasotransmitters represent unique challenges. This is especially true with carbon monoxide, which does not have an easy "handle" for bioreversible derivatization. By taking advantage of an intramolecular Diels-Alder reaction, we have developed a prodrug strategy for preparations of organic CO prodrugs that are stable during synthesis and storage, and yet readily release CO with tunable release rates under near physiological conditions...
November 23, 2016: Angewandte Chemie
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