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https://www.readbyqxmd.com/read/28636400/click-biotinylation-of-plga-template-for-biotin-receptor-oriented-delivery-of-doxorubicin-hydrochloride-in-4t1-cell-induced-breast-cancer
#1
Yuvraj Singh, K K Durga Rao Viswanadham, Arun Kumar Jajoriya, Jayagopal Meher, Kavit Raval, Swati Jaiswal, Jayant Dewangan, H K Bora, Srikanta Kumar Rath, Jawahar Lal, Durga Prasad Mishra, Manish Kumar Chourasia
PLGA was functionalized with PEG and biotin using click chemistry to generate a biotin receptor targeted copolymer (Biotinylated-PEG-PLGA) which in turn was used to fabricate ultrafine nanoparticles (BPNP) of doxorubicin hydrochloride (DOX) for effective delivery in 4T1 cell induced breast cancer. However adequate entrapment of a hydrophilic bioactive like DOX in a hydrophobic polymer system made of PLGA is not usually possible. We therefore modified a conventional W/O/W emulsion method by utilizing ammonium chloride in the external phase to constrain DOX in dissolved polymer phase by supressing its inherent aqueous solubility as per common ion effect...
June 21, 2017: Molecular Pharmaceutics
https://www.readbyqxmd.com/read/28636366/oxygenation-via-c-h-c-c-bond-activation-with-molecular-oxygen
#2
Yu-Feng Liang, Ning Jiao
The selective oxidation of organic molecules is a fundamentally important component of modern synthetic chemistry. In the past decades, direct oxidative C-H and C-C bond functionalization has proved to be one of the most efficient and straightforward methods to synthesize complex products from simple and readily available starting materials. Among these oxidative processes, the use of molecular oxygen as a green and sustainable oxidant has attracted considerable attention because of its highly atom-economical, abundant, and environmentally friendly characteristics...
June 21, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28636358/transferable-atom-centered-potentials-for-the-correction-of-basis-set-incompleteness-errors-in-density-functional-theory
#3
Alberto Otero-de-la-Roza, Gino A DiLabio
Recent progress in the accurate calculation of non-covalent interactions has enabled density-functional theory (DFT) to model systems relevant in biological and supramolecular chemistry. The application of DFT methods using atom-centered Gaussian basis sets to large systems is limited by the number of basis functions required to accurately model thermochemistry and, in particular, weak intermolecular interactions. Basis-set incompleteness error (BSIE) arising from the use of incomplete basis sets leads to erroneous intermolecular energies, bond dissociation energies, and structures...
June 21, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28636349/water-dynamics-from-the-surface-to-the-interior-of-a-supramolecular-nanostructure
#4
Julia H Ortony, Baofu Qiao, Christina J Newcomb, Timothy J Keller, Liam C Palmer, Elad Deiss-Yehiely, Monica Olvera de la Cruz, Songi Han, Samuel I Stupp
Water within and surrounding the structure of a biological system adopts context-specific dynamics that mediate virtually all of the events involved in the inner workings of a cell. These events range from protein folding and molecular recognition to the formation of hierarchical structures. Water dynamics are mediated by the chemistry and geometry of interfaces where water and biomolecules meet. Here we investigate experimentally and computationally the translational dynamics of vicinal water molecules within the volume of a supramolecular peptide nanofiber measuring 6...
June 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28636028/supramolecular-functional-assemblies-dynamic-membrane-transporters-and-peptide-nanotubular-composites
#5
Alberto Fuertes, Marisa Juanes, Juan R Granja, Javier Montenegro
The fabrication of functional molecular devices constitutes one of the most important current challenges for chemical sciences. The complex processes accomplished by living systems continuously demand the assistance of non-covalent interactions between molecular building blocks. Additionally, these building blocks (proteins, membranes, nucleotides) are also constituted by self-assembled structures. Therefore, supramolecular chemistry is the discipline required to understand the properties of the minimal self-assembled building blocks of living systems and to develop new functional smart materials...
June 21, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28634827/highly-functionalized-cyclic-%C3%AE-amino-acid-moieties-as-promising-scaffolds-in-peptide-research-and-drug-design
#6
REVIEW
Loránd Kiss, István M Mándity, Ferenc Fülöp
Peptide-based drug research has received high attention in the field of medicinal chemistry over the past decade. For drug design, to improve proteolytic stability, it is desirable to include unnatural building blocks, such as conformationally restricted β-amino acid moieties, into the peptide sequence. Accordingly, the synthesis and incorporation of such conformationally rigid systems into novel type of peptides has gained large interest. Our research group has designed highly efficient methods for the construction of potential antimicrobial peptides...
May 30, 2017: Amino Acids
https://www.readbyqxmd.com/read/28634602/recent-advances-in-the-computational-chemistry-of-soft-porous-crystals
#7
Guillaume Fraux, François-Xavier Coudert
Here we highlight recent progress in the field of computational chemistry of nanoporous materials, focusing on methods and studies that address the extraordinary dynamic nature of these systems: the high flexibility of their frameworks, the large-scale structural changes upon external physical or chemical stimulation, and the presence of defects and disorder. The wide variety of behavior demonstrated in soft porous crystals, including the topical class of metal-organic frameworks, opens new challenges for computational chemistry methods at all scales...
June 21, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28633869/baccaurea-angulata-fruit-juice-ameliorates-altered-hematological-and-biochemical-biomarkers-in-diet-induced-hypercholesterolemic-rabbits
#8
Idris Adewale Ahmed, Maryam Abimbola Mikail, Muhammad Ibrahim
Hypercholesterolemia is an important risk factor linked to the alteration of blood hematology and clinical chemistry associated with the development and progression of atherosclerosis. Previous studies have demonstrated the safety and potential health benefits of Baccaurea angulata (BA) fruit. We hypothesized that the oral administration of BA fruit juice could ameliorate the alteration in the hematological and biochemical biomarkers of diet-induced hypercholesterolemic rabbits. The aim of this study was to investigate the effects of different doses of BA juice on the hematological and biochemical biomarkers in normo- and hypercholesterolemic rabbits...
June 2017: Nutrition Research
https://www.readbyqxmd.com/read/28632260/visualization-of-the-protein-corona-towards-a-biomolecular-understanding-of-nanoparticle-cell-interactions
#9
Maria Kokkinopoulou, Johanna Simon, Katharina Landfester, Volker Mailänder, Ingo Lieberwirth
The use of nanocarriers in biology and medicine is complicated by the current need to understand how nanoparticles interact in complex biological surroundings. When nanocarriers come into contact with serum, proteins immediately adsorb onto their surface, forming a protein corona which defines their biological identity. Although the composition of the protein corona has been widely determined by proteomics, its morphology still remains unclear. In this study we show for the first time the morphology of the protein corona using transmission electron microscopy...
June 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28631790/multidentate-silyl-ligands-in-transition-metal-chemistry
#10
M Simon, F Breher
Silyl ligands are of great interest in transition metal coordination chemistry since they exhibit a strong trans-influence and create electron rich metals centres, which are in turn eligible to activate reagents. This review presents and discusses the use of multidentate Si-based ligand systems in transition metal coordination chemistry. These include tri- and tetradentate pincer and scorpionate-type ligands, which have been developed in recent years in order to tailor both steric and electronic properties for achieving a defined control over the reactivity of a transition metal complex...
June 20, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28631435/polar-intermetallics-pr5co2ge3-and-pr7co2ge4-with-planar-hydrocarbon-like-metal-clusters
#11
Qisheng Lin, Kaiser Aguirre, Scott M Saunders, Timothy A Hackett, Yong Liu, Valentin Taufour, Durga Paudyal, Sergey Budko, Paul C Canfield, Gordon J Miller
Planar hydrocarbon-like metal clusters may foster new insights linking organic molecules with conjugated - bonding interactions and inorganic structures in terms of their bonding characteristics. However, such clusters are uncommon in polar intermetallics. Herein, we report two polar intermetallic phases, Pr5Co2Ge3 and Pr7Co2Ge4, both of which feature such planar metal clusters, viz., ethylene-like [Co2Ge4] clusters plus the concatenated forms and polyacene-like [Co2Ge2]n ribbons in Pr5Co2Ge3, and 1,2,4,5-tetramethylbenzene-like [Co4Ge6] cluster in Pr7Co2Ge4...
June 19, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28628332/watson-crick-base-pair-radical-cation-as-a-model-for-oxidative-damage-in-dna
#12
Linda Feketeova, Bun Chan, George N Khairallah, Vincent Steinmetz, Philippe Maître, Leo Radom, Richard A J O'Hair
The deleterious cellular effects of ionizing radiation are well known but the mechanisms causing DNA damage are poorly understood. The accepted molecular events involve initial oxidation and deprotonation at guanine sites, triggering hydrogen-atom-abstraction reactions from the sugar moieties, causing DNA strand breaks. Probing the chemistry of the initially formed radical cation has been challenging. Here we generate, spectroscopically characterise and examine the reactivity of the Watson-Crick nucleobase-pair radical cation in the gas-phase...
June 19, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28628248/kinetic-selectivity-and-thermodynamic-features-of-competitive-imine-formation-in-dynamic-covalent-chemistry
#13
Jean-Marie Lehn, Sirinan Kulchat, Manuel N Chaur
The kinetic and thermodynamic selectivities of imine formation have been investigated for several dynamic covalent libraries of aldehydes and amines. Two systems were examined, involving the reaction of different types of primary amino groups (aliphatic amines, alkoxy-amines, hydrazides and hydrazines) with two types of aldehydes, sulfobenzaldehyde and pyridoxal phosphate in aqueous solution at different pD (5.0, 8.5, 11.4) on one hand, 2-pyridinecarboxaldehyde and salicylaldehyde in organic solvents on the other hand...
June 19, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28627887/controlling-the-catalytic-functions-of-dnazymes-within-constitutional-dynamic-networks-of-dna-nanostructures
#14
Shan Wang, Liang Yue, Zohar Shpilt, Alessandro Cecconello, Jason S Kahn, Jean-Marie Lehn, Itamar Willner
Mimicking complex cellular dynamic chemical networks being up-regulated or down-regulated by external triggers is one of the challenges in system chemistry. Constitutional dynamic networks, CDNs, composed of exchangeable components that respond to environmental triggers by self-adaption, provide general means to mimic biosystems. We use the structural and functional information encoded in nucleic acid nanostructures to construct effector (input)-triggered constitutional dynamic networks that reveal adaptable catalytic properties...
June 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28627150/-applying-a-set-of-indicators-to-evaluate-the-primary-health-care
#15
Antonio Giampietro Russo, Maria Teresa Greco
OBJECTIVES: to develop a system of indicators to monitor the quality of health care, in terms of safety, effectiveness, and appropriateness to allow the integrated promotion of the welfare of the effectiveness and quality. DESIGN: retrospective study. SETTING AND PARTICIPANTS: all general practitioners (GPs) with at least 100 patients in loading at 1.1.2015 were included. The setting chosen is the Primary Care of the Agency for Health Protection of the Province of Milan (Northern Italy)...
January 2017: Epidemiologia e Prevenzione
https://www.readbyqxmd.com/read/28626570/riboflavin-as-a-bioorthogonal-photocatalyst-for-the-activation-of-a-pt-iv-prodrug
#16
Silvia Alonso-de Castro, Emmanuel Ruggiero, Ane Ruiz-de-Angulo, Elixabete Rezabal, Juan C Mareque-Rivas, Xabier Lopez, Fernando López-Gallego, Luca Salassa
Encouraging developments demonstrate that few transition metal and organometallic catalysts can operate in a bioorthogonal fashion and promote non-natural chemistry in living systems by minimizing undesired side reactions with cellular components. These catalytic processes have potential for applications in medicinal chemistry and chemical biology. However, the stringent conditions of the cell environment severely limit the number of accessible metal catalysts and exogenous reactions. Herein, we report an unorthodox approach and a new type of bioorthogonal catalytic reaction, in which a metal complex is an unconventional substrate and an exogenous biological molecule acts as a catalyst...
June 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28625765/flavin-dependent-epitranscriptomic-world
#17
REVIEW
Murielle Lombard, Djemel Hamdane
RNAs molecules fulfill key roles in the expression and regulation of the genetic information stored within the DNA chromosomes. In addition to the four canonical bases, U, C, A and G, RNAs harbor various chemically modified derivatives which are generated post-transcriptionally by specific enzymes acting directly at the polymer level. More than one hundred naturally occurring modified nucleosides have been identified to date, the largest number of which is found in tRNAs and rRNA. This remarkable biochemical process produces widely diversified RNAs further expanding the functional repertoires of these nucleic acids...
June 15, 2017: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/28623662/advances-in-the-analysis-of-water-and-wastewater-samples-using-various-sensing-protocols-and-microfluidic-devices-based-on-pad-and-%C3%AE-tas-systems
#18
Krzysztof Piaskowski, Renata Świderska-Dąbrowska, Aleksandra Kaleniecka, Paweł K Zarzycki
The main goal of this review is to summarize practical approaches concerning the application of microfluidic systems for the analysis of various biomarkers and pollutants, as well as microbes, in water and wastewater matrixes. This problem involves multidisciplinary expertise combining research knowledge from various areas, including wet chemistry, biochemistry, physical chemistry, molecular biology, genetics, signal processing, microelectronics material science, and separation science. It has been documented that fairly primitive but fast and inexpensive screening methods involving paper-based analytical devices (PADs) and micro total analytical systems (μTAS) can be considered as serious alternatives to their more advanced counterparts such as GC, HPLC, and capillary electrophoresis coupled to various sophisticated detectors (e...
June 16, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28623653/miniaturized-temperature-controlled-planar-chromatography-micro-tlc-as-a-versatile-technique-for-fast-screening-of-micropollutants-and-biomarkers-derived-from-surface-water-ecosystems-and-during-technological-processes-of-wastewater-treatment
#19
Magdalena M Ślączka-Wilk, Elżbieta Włodarczyk, Aleksandra Kaleniecka, Paweł K Zarzycki
There is increasing interest in the development of simple analytical systems enabling the fast screening of target components in complex samples. A number of newly invented protocols are based on quasi separation techniques involving microfluidic paper-based analytical devices and/or micro total analysis systems. Under such conditions, the quantification of target components can be performed mainly due to selective detection. The main goal of this paper is to demonstrate that miniaturized planar chromatography has the capability to work as an efficient separation and quantification tool for the analysis of multiple targets within complex environmental samples isolated and concentrated using an optimized SPE method...
June 16, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28621817/gas-phase-basicities-of-polyfunctional-molecules-part-6-cyanides-and-isocyanides
#20
REVIEW
Guy Bouchoux
This paper gathers structural and thermochemical informations related to the gas-phase basicity of molecules containing cyanides (nitriles) and isocyanides (isonitriles) functional groups. It constitutes the sixth part of a general review devoted to gas-phase basicities of polyfunctional compounds. A large corpus of cyanides and isocyanides molecules is examined under seven major chapters. In the first one, a rapid overview of the definitions and methods leading to gas-phase basicity, GB, proton affinity, PA, and protonation entropy, Δp S°, is given...
June 16, 2017: Mass Spectrometry Reviews
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