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https://www.readbyqxmd.com/read/28340377/possible-protective-effect-of-royal-jelly-against-cyclophosphamide-induced-prostatic-damage-in-male-albino-rats-a-biochemical-histological-and-immuno-histo-chemical-study
#1
Sara Mohammed Naguib Abdel-Hafez, Rehab Ahmed Rifaai, Walaa Yehia Abdelzaher
Almost all the chemotherapy treat many cancer types effectively, but it leads to severe side effects. Chemotherapy like cyclophosphamide (CP) not works only on the active cells, such as cancer cells, but also acts on the healthy cells. Royal jelly (RJ) was reported to have a lot of therapeutic effects besides being an anti-oxidant and anti-cancer agent. The purpose of this study was to assess the possible protective role of RJ in ameliorating the toxic effects of CP overdose in the rat prostatic tissue. The rats were separated into 4 groups; control group, RJ group, CP group and RJ with CP group...
March 21, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28340291/-head-to-head-prenyl-synthases-in-some-pathogenic-bacteria
#2
Christopher J Schwalen, Xinxin Feng, Weidong Liu, Bing O-Dowd, Tzu-Ping Ko, Christopher J Shin, Rey-Ting Guo, Douglas A Mitchell, Eric Oldfield
Many organisms contain "head-to-head" isoprenoid synthases and here, we investigate three types of such enzymes from the pathogens Neisseria meningitidis, N. gonorrhoeae, and Enterococcus hirae. The E. hirae enzyme was found to produce dehydrosqualene and we solved an inhibitor-bound structure which revealed a fold similar to that of CrtM from Staphylococcus aureus. In contrast, the homologous proteins from Neisseria spp. carried out only the "first half" reaction, yielding presqualene diphosphate (PSPP). Based on product analyses, bioinformatics, and mutagenesis we conclude that the Neisseria proteins are HpnDs (PSPP synthases)...
March 24, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/28339693/neuronal-signaling-repertoire-in-the-mammalian-sperm-functionality
#3
Alfredo Ramírez-Reveco, Franz Villarroel-Espíndola, Joan E Rodríguez-Gil, Ilona I Concha
The common embryonic origin has been a recurrent explanation to understand the presence of "neural receptors" in sperm. However, this designation has conditioned a bias marked by the classical neurotransmission model, dismissing the possibility that neurotransmitters can play specific roles in the sperm function by themselves. For instance, the launching of acrosome reaction, a fundamental sperm function, includes several steps that recall the process of presynaptic secretion. Unlike of postsynaptic neuron, whose activation is mediated by molecular interaction between neurotransmitter and postsynaptic receptors, the oocyte activation is not mediated by receptors, but by cytosolic translocation of sperm phospholipase (PLCζ)...
February 20, 2017: Biology of Reproduction
https://www.readbyqxmd.com/read/28339615/viable-offspring-after-imaging-of-ca2-oscillations-and-visualization-of-the-cortical-reaction-in-mouse-eggs%C3%A2
#4
Yuhkoh Satouh, Kaori Nozawa, Kazuo Yamagata, Takao Fujimoto, Masahito Ikawa
During mammalian fertilization, egg Ca 2+ oscillations are known to play pivotal roles in triggering downstream events such as resumption of the cell cycle and the establishment of blocks to polyspermy. However, viable offspring have not been obtained after monitoring Ca 2+ oscillations, and their spatiotemporal links to subsequent events are still to be examined. Therefore, the development of imaging methods to avoid phototoxic damage while labeling these events is required. Here, we examined the usefulness of genetically encoded Ca 2+ indicators for optical imaging (GECOs), in combination with spinning-disk confocal imaging...
February 3, 2017: Biology of Reproduction
https://www.readbyqxmd.com/read/28339216/embarking-on-a-chemical-space-odyssey
#5
Shiao Y Chow, Adam Nelson
The chemical space explored in drug discovery programs is restricted by a narrow reaction toolkit and the frequent failure of even these reactions with polar and functionalized substrates. Recently, high-throughput reaction optimization has been integrated into discovery workflows, thereby increasing the value of specific reaction classes in the toolkit. It is likely that high-throughput experimentation will enable expansion of the synthetic chemistry that is widely exploited in discovery, thereby increasing innovation in medicinal chemistry...
March 24, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28339204/liquid-marble-coalescence-and-triggered-microreaction-inspired-by-acoustic-levitation
#6
Zhen Chen, Duyang Zang, Liang Zhao, Mengfei Qu, Xu Li, Xiaoguang Li, Lixin Li, Xingguo Geng
Liquid marbles show promising potential application in the microreactor field. It is of great importance to control the coalescence between two or multiple liquid marbles, however, it is highly difficult to successfully merge two isolated marbles due to their mechanically robust particle shells. In this work, we accomplished the coalescence of multiple liquid marbles via acoustic levitation. The dynamic behaviors of the liquid marbles were monitored by a high-speed camera to find that driven by the sound field, the liquid marbles moved towards each other, collided, and eventually coalesced into a larger single marble...
March 24, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28339186/quantum-chemical-strain-analysis-for-mechanochemical-processes
#7
Tim Stauch, Andreas Dreuw
The use of mechanical force to initiate a chemical reaction is an efficient alternative to the conventional sources of activation energy, i.e., heat, light, and electricity. Applications of mechanochemistry in academic and industrial laboratories are diverse, ranging from chemical syntheses in ball mills and ultrasound baths to direct activation of covalent bonds using an atomic force microscope. The vectorial nature of force is advantageous because specific covalent bonds can be preconditioned for rupture by selective stretching...
March 24, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28338686/an-iron-catalysed-c-c-bond-forming-spirocyclization-cascade-providing-sustainable-access-to-new-3d-heterocyclic-frameworks
#8
Kirsty Adams, Anthony K Ball, James Birkett, Lee Brown, Ben Chappell, Duncan M Gill, P K Tony Lo, Nathan J Patmore, Craig R Rice, James Ryan, Piotr Raubo, Joseph B Sweeney
Heterocyclic architectures offer powerful creative possibilities to a range of chemistry end-users. This is particularly true of heterocycles containing a high proportion of sp(3)-carbon atoms, which confer precise spatial definition upon chemical probes, drug substances, chiral monomers and the like. Nonetheless, simple catalytic routes to new heterocyclic cores are infrequently reported, and methods making use of biomass-accessible starting materials are also rare. Here, we demonstrate a new method allowing rapid entry to spirocyclic bis-heterocycles, in which inexpensive iron(III) catalysts mediate a highly stereoselective C-C bond-forming cyclization cascade reaction using (2-halo)aryl ethers and amines constructed using feedstock chemicals readily available from plant sources...
April 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28338683/aldehydes-as-alkyl-carbanion-equivalents-for-additions-to-carbonyl-compounds
#9
Haining Wang, Xi-Jie Dai, Chao-Jun Li
Nucleophilic addition reactions of organometallic reagents to carbonyl compounds for carbon-carbon bond construction have played a pivotal role in modern chemistry. However, this reaction's reliance on petroleum-derived chemical feedstocks and a stoichiometric quantity of metal have prompted the development of many carbanion equivalents and catalytic metal alternatives. Here, we show that naturally occurring carbonyls can be used as latent alkyl carbanion equivalents for additions to carbonyl compounds, via reductive polarity reversal...
April 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28338602/design-and-synthesis-of-novel-pyrazole-substituted-different-nitrogenous-heterocyclic-ring-systems-as-potential-anti-inflammatory-agents
#10
Eman S Nossier, Hoda H Fahmy, Nagy M Khalifa, Wafaa I El-Eraky, Marawan A Baset
With the aim of developing novel anti-inflammatory scaffolds, a new series of pyrazole-substituted various nitrogenous heterocyclic ring systems at C-4 position were synthesized through different chemical reactions and validated by means of spectral and elemental data. The new obtained compounds were investigated for their anti-inflammatory activity using the carrageenan-induced paw edema standard technique and revealed that, compound 6b showed increased potency with % inhibition of edema 85.23 ± 1.92 and 85...
March 24, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28338329/evidence-for-electron-hole-pair-excitation-in-the-associative-desorption-of-h2-and-d2-from-au-111
#11
Quan Shuai, Sven Kaufmann, Daniel J Auerbach, Dirk Schwarzer, Alec M Wodtke
The dissociative adsorption reaction of hydrogen on noble metals is believed to be well described within the Born-Oppenheimer approximation. In this work, we have experimentally derived translational energy distributions for selected quantum states of H2 and D2 formed in associative desorption reactions at a Au(111) surface. Using the principle of detailed balance, we compare our results to theory carried out at the same level of sophistication as was done for the reaction on copper. The theory predicts much higher translational excitation than is seen in experiment and fails to reproduce the experimentally observed isotope effect...
March 24, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28338327/analysis-of-the-acting-forces-in-a-theory-of-catalysis-and-mechanochemistry
#12
Wolfgang Quapp, Josep Maria Bofill, Jordi Ribas-Ariño
The theoretical description of a chemical process resulting from the application of mechanical or catalytical stress to a molecule is performed by the generation of an effective potential energy surface (PES). Changes for minima and saddle points by the stress are described by Newton trajectories (NTs) on the original PES. From the analysis of the acting forces we postulate the existence of pulling corridors build by families of NTs which connect the same stationary points. For different exit saddles of different height we discuss the corresponding pulling corridors; mainly by simple two-dimensional surfaces models...
March 24, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28338264/engineering-high-energy-interfacial-structures-for-high-performance-oxygen-involving-electrocatalysis
#13
Chunxian Guo, Yao Zheng, Jingrun Ran, Fangxi Xie, Mietek Jaroniec, Shi-Zhang Qiao
Engineering high-energy interfacial structures for high-performance electrocatalysis is achieved by chemical coupling of active CoO nanoclusters and high-index facet Mn3 O4 nano-octahedrons (hi-Mn3 O4 ). A thorough characterization, including synchrotron-based near edge X-ray absorption fine structure, reveals that strong interactions between both components promote the formation of high-energy interfacial Mn-O-Co species and high oxidation state CoO, from which electrons are drawn by Mn(III) -O present in hi-Mn3 O4 ...
March 24, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28338143/mastering-the-non-equilibrium-assembly-and-operation-of-molecular-machines
#14
Cristian Pezzato, Chuyang Cheng, J Fraser Stoddart, R Dean Astumian
In mechanically interlocked compounds, such as rotaxanes and catenanes, the molecules are held together by mechanical rather than chemical bonds. These compounds can be engineered to have several well-defined mechanical states by incorporating recognition sites between the different components. The rates of the transitions between the recognition sites can be controlled by introducing steric "speed bumps" or electrostatically switchable gates. A mechanism for the absorption of energy can also be included by adding photoactive, catalytically active, or redox-active recognition sites, or even charges and dipoles...
March 24, 2017: Chemical Society Reviews
https://www.readbyqxmd.com/read/28337914/electrically-actuated-valves-for-woven-fabric-lateral-flow-devices
#15
Tanya Narahari, Dhananjaya Dendukuri, Shashi K Murthy
The integration of flow control elements into low-cost biosensors, presents a significant engineering challenge. This article describes the development and integration of active, chemical valves into lateral flow devices, using a scalable, single-step, weaving-based manufacturing approach. The valve was constructed from an electrically conductive polymer, polypyrrole. The polymer switches between wetting and non-wetting states when it is reduced and oxidized via the application of an electrochemical potential...
March 24, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28337670/supramolecular-systems-and-chemical-reactions-in-single-molecule-break-junctions
#16
REVIEW
Xiaohui Li, Duan Hu, Zhibing Tan, Jie Bai, Zongyuan Xiao, Yang Yang, Jia Shi, Wenjing Hong
The major challenges of molecular electronics are the understanding and manipulation of the electron transport through the single-molecule junction. With the single-molecule break junction techniques, including scanning tunneling microscope break junction technique and mechanically controllable break junction technique, the charge transport through various single-molecule and supramolecular junctions has been studied during the dynamic fabrication and continuous characterization of molecular junctions. This review starts from the charge transport characterization of supramolecular junctions through a variety of noncovalent interactions, such as hydrogen bond, π-π interaction, and electrostatic force...
April 2017: Topics in Current Chemistry (Journal)
https://www.readbyqxmd.com/read/28337628/study-of-plasma-off-gas-treatment-from-spent-ion-exchange-resin-pyrolysis
#17
Hernán Ariel Castro, Vittorio Luca, Hugo Luis Banchi
Polystyrene divinylbenzene-based ion exchange resins are employed extensively within nuclear power plants (NPPs) and research reactors for purification and chemical control of the cooling water system. To maintain the highest possible water quality, the resins are regularly replaced as they become contaminated with a range of isotopes derived from compromised fuel elements as well as corrosion and activation products including (14)C, (60)Co, (90)Sr, (129)I, and (137)Cs. Such spent resins constitute a major proportion (in volume terms) of the solid radioactive waste generated by the nuclear industry...
March 23, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28336839/synthesis-of-polyhydroxybutyrate-particles-with-micro-to-nanosized-structures-and-application-as-protective-coating-for-packaging-papers
#18
Vibhore Kumar Rastogi, Pieter Samyn
This study reports on the development of bio-based hydrophobic coatings for packaging papers through deposition of polyhydroxybutyrate (PHB) particles in combination with nanofibrillated cellulose (NFC) and plant wax. In the first approach, PHB particles in the micrometer range (PHB-MP) were prepared through a phase-separation technique providing internally-nanosized structures. The particles were transferred as a coating by dip-coating filter papers in the particle suspension, followed by sizing with a carnauba wax solution...
December 30, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28336335/management-of-spent-shea-waste-an-instrumental-characterization-and-valorization-in-clay-bricks-construction
#19
A N Adazabra, G Viruthagiri, N Shanmugam
This work studies the reuse of spent shea waste as an economic construction material in improving fired clay bricks manufacture aside providing a novel approach to ecofriendly managing its excessive generated from the shea agroindustry. For this purpose, the influence of spent shea waste addition on the chemical, mineralogical, molecular bonding and technological properties (i.e. compressive strength and water absorption) of the fired clay bricks were extensively investigated. The results indicated that the chemical, mineralogical, phase transformations, molecular bonding and thermal behavior of the produced bricks were practically unaffected by the addition of spent shea waste...
March 20, 2017: Waste Management
https://www.readbyqxmd.com/read/28336067/measuring-and-imaging-metal-ions-with-fluorescence-based-biosensors-speciation-selectivity-kinetics-and-other-issues
#20
Richard B Thompson, Carol A Fierke
Fluorescence-based biosensors have shown themselves to be a powerful tool for the study of a variety of chemical species in biological systems, notably including metal ions. This chapter provides an overview of several important issues in using such sensors to study metallobiochemistry. These issues include selectivity for the analyte over potential interferents, including those that do not themselves induce a signal, the different forms in which metal ions are found (speciation), the utility of metal ion buffers, and the importance of kinetics in studying metal ion binding reactions...
2017: Methods in Enzymology
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