G-protein beta gamma subunits mediate specific phosphorylation of the protein-tyrosine phosphatase SH-PTP1 induced by lysophosphatidic acid

SH-PTP1 is a protein-tyrosine phosphatase preferentially expressed in hematopoietic cells and bearing two SH2 (src homology-2) domains. In the human megakaryocytic cell line Dami, lysophosphatidic acid (LPA) promoted a rapid increase in SH-PTP1 phosphorylation on both serine and tyrosine residues. Only tyrosine phosphorylation was significantly inhibited by pertussis toxin and by the protein kinase C inhibitor GF109203X. Moreover, SH-PTP1 was phosphorylated upon challenge with other agonists acting via G-protein-coupled receptors such as alpha-thrombin, epinephrine, and ADP, whereas the closely related protein-tyrosine phosphatase SH-PTP2 failed to share such a regulation in Dami cells. We developed an in vitro assay that reproduced LPA-dependent phosphorylation of SH-PTP1 in a cell-free system. The fusion protein glutathione S-transferase-beta-adrenergic receptor kinase 1-(495-689) or the transducin subunit Galphat-GDP, which act as specific antagonists of Gbetagamma, inhibited SH-PTP1 phosphorylation. Moreover, purified transducin Gbetagamma subunits mimicked the effect of LPA. Finally, stable expression of beta-adrenergic receptor kinase 1-(495-689) in Dami cells resulted in the inhibition of SH-PTP1 as a specific target of protein kinases linked to G-protein-coupled receptors via Gbetagamma subunits.     

A Simple Method for Estimating Mean Annual Groundwater Recharge for Drift-Free Areas of the Chalk and Permo-Triassic Sandstone Aquifers in the UK

At present, several methods for estimating groundwater recharge are in use in the UK, resulting in a range of estimates of groundwater recharge in any one area. However, there is a need for a robust national methodology with a firm scientific basis. As a first stage, a simple method has been developed to allow the rapid estimation of the mean annual groundwater recharge on drift-free areas of the major aquifers of England and Wales.
A simple soil-moisture model, with inputs of daily rainfall and potential evaporation, has been used to produce a series of nomographs. These can be used to estimate (a) mean annual groundwater recharge from data which are readily available, (b) annual values of rainfall, and (c) MORECS potential evaporation for grass. These estimates are aggregated to give the total for the area by including information on the land cover.     

Studies on freezing of partially dehydrated spinach

Spinach (Spinacea oleracea) was dehydrated at 70 °C, partially dehydrated frozen (dried to its critical moisture ratio and frozen at ?20 °C) and frozen at ?20 °C. Results indicated that the time required for spinach dehydration was 7 h. Thus, the moisture ratio was 10.1 and 0.054 for the fresh and dried spinach, respectively. The critical moisture ratio during dehydration process was 2.20 after 2.65 h of drying time. Reducing sugars, free amino nitrogen, ash, iron and magnesium were slightly decreased in the partially dehydrated frozen spinach relative to the fresh samples. Dehydration markedly degraded the total chlorophyll, chlorophyll a, chlorophyll b, carotenoides and ascorbic acid whereas the freezing of partially-dehydrated spinach and freezing process were less effective. On the other hand, freezing of partially dehydrated spinach increased phaeophytin. There were no changes in pH-values of studied preserved samples. Freezing of partially dehydrated spinach improved the reconstitution of product at 100 °C and at room temperature (25 °C) comparing to dehydration. The drip loss of frozen spinach was 16.4% after 105 min of thawing time. Cooked fresh and frozen spinach were better in colour, flavour, texture, appearance and shape and over-all acceptability than that of dehydrated cooked one. Moreover, freezing of partially dehydrated spinach improved the aforementioned properties.     

Thermally stimulated depolarization currents in γ-irradiated β-spodumene solid solution ceramic

Thermally stimulated depolarization currents (TSDC) in unirradiated and -irradiated press prepared -spodumene solid solution ceramic have been investigated within the wide temperature range 20–160°C. Doses in the range 10–10⁵ Gy were used. The TSDC spectrum at relatively high polarizing fields shows two relaxation peaks whose positions and intensities depend on the polarization conditions and -doses. Discussion of data is given on the basis that dipolar and space-charge polarization coexist in the used ceramic material. Activation energies for space-charge peak are determined from the initial rise of thermal current peak under different -doses. Aging effect clearify that the longer the aging time, the smaller the polarization. Pyroelectric current data provide further support to space charge effects.     

The Influence of Copper–Copper Interaction on the Structure and Applications of a Metal–Organic Framework Based on Cyanide and 3-Chloropyridine

The structure of the new metal–organic framework, [(CuCN)₂·(3-Clpy)], 1, was characterized by IR, UV–visible, TGA and X-ray single crystal analysis. The structure of 1 consists of CuCN building blocks, which are connected by CN group to form two different chains; one puckered chain with TP-3 geometry around Cu(1) and a linear Cu(2)(CN)₂ chain. The two kinds of chains are bonded by cuprophilic interactions creating a 3D-network. The network structure of 1 is further close-backed by π–π stacking and hydrogen bonds. The electronic absorption and emission spectra as well as the thermodynamic parameters from TGA of the MOF 1 are discussed. MOF 1 was used as an effective heterogeneous catalyst for the oxidative discoloration of methylene blue dye by dilute solution of hydrogen peroxide as the oxidant. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the in vitro antitumor activity of MOF 1 on human breast cancer cell line, MCF7.     

Assembly, Fluorescence Properties and Antitumor Activity of Novel Silver(I) Cyanide Supramolecular Coordination Polymer Based on Trans-1,2-bis(4-pyridyl)ethene and Me3SnCl

A bimetallic supramolecular coordination polymer; {[(Me₃Sn)₈Ag₄(OH)₄(CN)₈(tbpe)](tbpe)} _n , 1, was obtained by the reaction in situ of K₂[Ag(CN)₂] with Me₃SnCl and trans-1,2-bis(4-pyridyl)ethene (tbpe) in a H₂O/MeCN/NH₃ solvent. The structure of 1 consists of discrete puckered tetranuclear chains comprising {[(Me₃Sn)₄Ag₂(OH)₂(CN)₄]₂(tbpe)} in addition to one template free tbpe ligand. In these chains, the bridging hydroxyl group and the bipodal tbpe ligand are used to give two novel spacers based on the organometallic Me₃Sn unit; i.e., a longer spacer [–CN–(Me₃)Sn–O(H)–(Me₃)Sn–L–(Me₃)Sn–O(H)–(Me₃)Sn–NC–] with a separation distance of 31.29 Å, and a relatively shorter spacer [–CN–(Me₃)Sn–O(H)–(Me₃)Sn–NC–] with a separation distance of 14.431 Å. Supramolecular interactions such as hydrogen bonding, π–π stacking, cation···π interactions, play a prominent role in the assembly of this compound. The structure of the SCP was also investigated by FTIR and electronic absorption spectra and thermal analysis and the data are compared to the prototype compounds. The SCP 1 exhibits strong fluorescence in acetonitrile and shows specific in vitro antitumor activity against human breast cancer cell line, MCF7.     

New bisphenol novolac epoxy resins for marine primer steel coating applications

Bisphenol derived from reaction of phenol with benzaldehyde was prepared in the presence of sulfuric acid as catalyst. Bisphenol novolacs were synthesized in both melting and solution processes using p-formaldehyde and formalin solution in the presence of oxalic acid catalyst. ¹H NMR analysis shows a high methylene bridge contents using the novolacs synthesized in a melting process. The bisphenol novolac epoxy resin was prepared by reaction with epichlorohydrine in the presence of sodium hydroxide as a catalyst. The prepared novolac epoxy resins were cured with 1,2-amino ethyl piperazine (AEP) as a curing agent. The cured resins were evaluated as organic coating for steel. The mechanical properties of the cured epoxy resins were evaluated by measuring both impact resistance and hardness. The chemical resistances of the cured resins were evaluated through salt spray resistance, hot water immersion, solvent resistance, acid and alkali resistance measurements. The data indicate that the cured epoxy resins have excellent chemical resistances as organic coatings among other cured resins.     

A Hybrid Regularization-Based Multi-Frame Super-Resolution Using Bayesian Framework

The prime purpose for the image reconstruction of a multi-frame super-resolution is to reconstruct a higher-resolution image through incorporating the knowledge obtained from a series of relevant low-resolution images, which is useful in numerous fields. Nevertheless, super-resolution image reconstruction methods are usually damaged by undesirable restorative artifacts, which include blurring distortion, noises, and stair-casing effects. Consequently, it is always challenging to achieve balancing between image smoothness and preservation of the edges inside the image. In this research work, we seek to increase the effectiveness of multi-frame super-resolution image reconstruction by increasing the visual information and improving the automated machine perception, which improves human analysis and interpretation processes. Accordingly, we propose a new approach to the image reconstruction of multi-frame super-resolution, so that it is created through the use of the regularization framework. In the proposed approach, the bilateral edge preserving and bilateral total variation regularizations are employed to approximate a high-resolution image generated from a sequence of corresponding images with low-resolution to protect significant features of an image, including sharp image edges and texture details while preventing artifacts. The experimental results of the synthesized image demonstrate that the new proposed approach has improved efficacy both visually and numerically more than other approaches.     

Gamma Irradiation-Induced Preparation of Polyacrylonitrile Acrylamide Nano-silica for Removal of Some Hazardous Metals

Journal of Inorganic and Organometallic Polymers and Materials - Gamma-irradiation initiated polymerization was utilized to prepare polyacrylonitrile acrylamide nano-silica (P(AN-AM)-NS). Various...