Characterizations of some N-substituted-salicylhydrazide in mixtures by NMR diffusion ordered spectroscopy

Several novel N-substituted-salicylhydrazide ligands, most of which are difficult to be purified or recrystallized so that their chemical configurations can not be confirmed by conventional NMR and/or X-ray diffraction techniques, were synthesized in this experiment, and their chemical configurations in mixture were analyzed and characterized by 2D NMR diffusion ordered spectroscopy (DOSY), a labor-saving virtual separation based on diffusion properties, together with several routine NMR techniques

Lentiviral gene transfer into the dorsal root ganglion of adult rats

<p>Abstract</p> <p>Background</p> <p>Lentivector-mediated gene delivery into the dorsal root ganglion (DRG) is a promising method for exploring pain pathophysiology and for genetic treatment of chronic neuropathic pain. In this study, a series of modified lentivector particles with different cellular promoters, envelope glycoproteins, and viral accessory proteins were generated to evaluate the requirements for efficient transduction into neuronal cells <it>in vitro </it>and adult rat DRG <it>in vivo</it>.</p> <p>Results</p> <p><it>In vitro</it>, lentivectors expressing enhanced green fluorescent protein (EGFP) under control of the human elongation factor 1α (EF1α) promoter and pseudotyped with the conventional vesicular stomatitis virus G protein (VSV-G) envelope exhibited the best performance in the transfer of EGFP into an immortalized DRG sensory neuron cell line at low multiplicities of infection (MOIs), and into primary cultured DRG neurons at higher MOIs. <it>In vivo</it>, injection of either first or second-generation EF1α-EGFP lentivectors directly into adult rat DRGs led to transduction rates of 19 ± 9% and 20 ± 8% EGFP-positive DRG neurons, respectively, detected at 4 weeks post injection. Transduced cells included a full range of neuronal phenotypes, including myelinated neurons as well as both non-peptidergic and peptidergic nociceptive unmyelinated neurons.</p> <p>Conclusion</p> <p>VSV-G pseudotyped lentivectors containing the human elongation factor 1α (EF1α)-EGFP expression cassette demonstrated relatively efficient transduction to sensory neurons following direct injection into the DRG. These results clearly show the potential of lentivectors as a viable system for delivering target genes into DRGs to explore basic mechanisms of neuropathic pain, with the potential for future clinical use in treating chronic pain.</p

Evidence of a metabolic memory to early-life dietary restriction in male C57BL/6 mice

&lt;p&gt;Background: Dietary restriction (DR) extends lifespan and induces beneficial metabolic effects in many animals. What is far less clear is whether animals retain a metabolic memory to previous DR exposure, that is, can early-life DR preserve beneficial metabolic effects later in life even after the resumption of ad libitum (AL) feeding. We examined a range of metabolic parameters (body mass, body composition (lean and fat mass), glucose tolerance, fed blood glucose, fasting plasma insulin and insulin-like growth factor 1 (IGF-1), insulin sensitivity) in male C57BL/6 mice dietary switched from DR to AL (DR-AL) at 11 months of age (mid life). The converse switch (AL-DR) was also undertaken at this time. We then compared metabolic parameters of the switched mice to one another and to age-matched mice maintained exclusively on an AL or DR diet from early life (3 months of age) at 1 month, 6 months or 10 months post switch.&lt;/p&gt; &lt;p&gt;Results: Male mice dietary switched from AL-DR in mid life adopted the metabolic phenotype of mice exposed to DR from early life, so by the 10-month timepoint the AL-DR mice overlapped significantly with the DR mice in terms of their metabolic phenotype. Those animals switched from DR-AL in mid life showed clear evidence of a glycemic memory, with significantly improved glucose tolerance relative to mice maintained exclusively on AL feeding from early life. This difference in glucose tolerance was still apparent 10 months after the dietary switch, despite body mass, fasting insulin levels and insulin sensitivity all being similar to AL mice at this time.&lt;/p&gt; &lt;p&gt;Conclusions: Male C57BL/6 mice retain a long-term glycemic memory of early-life DR, in that glucose tolerance is enhanced in mice switched from DR-AL in mid life, relative to AL mice, even 10 months following the dietary switch. These data therefore indicate that the phenotypic benefits of DR are not completely dissipated following a return to AL feeding. The challenge now is to understand the molecular mechanisms underlying these effects, the time course of these effects and whether similar interventions can confer comparable benefits in humans.&lt;/p&gt

Bioconjugates of Glucose Oxidase and Gold Nanorods Based on Electrostatic Interaction with Enhanced Thermostability

Bioconjugates made up of an enzyme and gold nanorods (GNRs) were fabricated by electrostatic interactions (layer-by-layer method, LBL) between anionic glucose oxidase (GOD) and positively charged GNRs. The assembled processes were monitored by UV–Vis spectra, zeta potential measurements, and transmission electron microscopy. The enzyme activity assays of the obtained bioconjugates display a relatively enhanced thermostability behavior in contrast with that of free enzyme. Free GOD in solution only retains about 22% of its relative activity at 90 °C. Unexpectedly, the immobilized GOD on GNRs still retains about 39.3% activity after the same treatment. This work will be of significance for the biologic enhancement using other kinds of anisotropic nanostructure and suggests a new way of enhancing enzyme thermostability using anisotropic metal nanomaterials

Structure of an Enzyme-Derived Phosphoprotein Recognition Domain

Membrane Associated Guanylate Kinases (MAGUKs) contain a protein interaction domain (GKdom) derived from the enzyme Guanylate Kinase (GKenz). Here we show that GKdom from the MAGUK Discs large (Dlg) is a phosphoprotein recognition domain, specifically recognizing the phosphorylated form of the mitotic spindle orientation protein Partner of Inscuteable (Pins). We determined the structure of the Dlg-Pins complex to understand the dramatic transition from nucleotide kinase to phosphoprotein recognition domain. The structure reveals that the region of the GKdom that once served as the GMP binding domain (GBD) has been co-opted for protein interaction. Pins makes significantly more contact with the GBD than does GMP, but primarily with residues that are conserved between enzyme and domain revealing the versatility of the GBD as a platform for nucleotide and protein interactions. Mutational analysis reveals that the GBD is also used to bind the GK ligand MAP1a, suggesting that this is a common mode of MAGUK complex assembly. The GKenz undergoes a dramatic closing reaction upon GMP binding but the protein-bound GKdom remains in the ‘open’ conformation indicating that the dramatic conformational change has been lost in the conversion from nucleotide kinase to phosphoprotein recognition domain

Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces

Spin-orbit coupling (SOC) describes the relativistic interaction between the spin and momentum degrees of freedom of electrons, and is central to the rich phenomena observed in condensed matter systems. In recent years, new phases of matter have emerged from the interplay between SOC and low dimensionality, such as chiral spin textures and spin-polarized surface and interface states. These low-dimensional SOC-based realizations are typically robust and can be exploited at room temperature. Here we discuss SOC as a means of producing such fundamentally new physical phenomena in thin films and heterostructures. We put into context the technological promise of these material classes for developing spin-based device applications at room temperature

Caretaker Brca1: keeping the genome in the straight and narrow

Inheritance of germline BRCA1 mutations is associated with a high risk of breast and ovarian cancers. A multitude of cellular functions has been ascribed to BRCA1, including transcription activation and various aspects of DNA repair. So far, indirect evidence has indicated a role for BRCA1 in the repair of double-strand breaks. Recently, an elegant gene targeting design was used to provide definitive evidence that BRCA1 promotes homologous recombination and limits nonhomologous mutagenic repair processes. This reaffirms the role of BRCA1 as caretaker in preserving genomic integrity

Measurement of the W+W−W^+W^- Production Cross Section and Search for Anomalous WWγWW\gamma and WWZWWZ Couplings in ppˉp \bar p Collisions at s=1.96\sqrt{s} = 1.96 TeV

This Letter describes the current most precise measurement of the $W$ boson pair production cross section and most sensitive test of anomalous $WW\gamma$ and $WWZ$ couplings in $p \bar p$ collisions at a center-of-mass energy of 1.96 TeV. The $WW$ candidates are reconstructed from decays containing two charged leptons and two neutrinos, where the charged leptons are either electrons or muons. Using data collected by the CDF II detector from 3.6 fb$^{-1}$ of integrated luminosity, a total of 654 candidate events are observed with an expected background contribution of $320 \pm 47$ events. The measured total cross section is $\sigma (p \bar p \to W^+ W^- + X) = 12.1 \pm 0.9 \textrm{(stat)} ^{+1.6}_{-1.4} \textrm{(syst)}$ pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous $WW\gamma$ and $WWZ$ couplings.Comment: submitted to Phys. Rev. Let

Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

The decay channel $\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p})$ is studied using a sample of $1.06\times 10^8$ $\psi^\prime$ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the $p\bar{p}$ invariant mass spectrum. The enhancement can be fit with an $S$-wave Breit-Wigner resonance function with a resulting peak mass of $M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2$ and a narrow width that is $\Gamma<38 {\rm MeV/}c^2$ at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

In situ production of titanium dioxide nanoparticles in molten salt phase for thermal energy storage and heat-transfer fluid applications

In this study, TiO2 nanoparticles (average particle size 16 nm) were successfully produced in molten salt phase and were showed to significantly enhance the specific heat capacity of a binary eutectic mixture of sodium and potassium nitrate (60/40) by 5.4 % at 390 °C and 7.5 % at 445 °C for 3.0 wt% of precursors used. The objective of this research was to develop a cost-effective alternate method of production which is potentially scalable, as current techniques utilized are not economically viable for large quantities. Enhancing the specific heat capacity of molten salt would promote more competitive pricing for electricity production by concentrating solar power plant. Here, a simple precursor (TiOSO4) was added to a binary eutectic mixture of potassium and sodium nitrate, heated to 450 °C, and cooled to witness the production of nanoparticles