Search

A broad scope of quinazolin-4(3H)-ones or benzothiadiazine 1,1-dioxides was obtained via a transition-metal free and convenient method. This approach involving KHSO4 promoted cyclization and dehydration between diverse functionalized 2-aminobenzamides or 2-aminobenzenesulfonamides and N, N-dimethylformamide derivatives. The protocol offers moderate to excellent yields (45%-93%) under mild condition in a short of reaction time of 6 hours. The use of an environment-friendly and less expensive catalyst KHSO4 also makes this protocol more attractive. [ABSTRACT FROM AUTHOR]

Despite the excellent properties, amorphous alloys find limited applications and to find plastic forming ability has been a longstanding problem. In this work, an effective ultrasonic assisted micro-shear punching (UMSP) method is proposed for amorphous alloys. By applying ultrasonic vibration and molten plastics viscous medium, a series of shapes and products with micro-length scale to macro-length scale can be successfully fabricated in 50 ms. Different from traditional crystalline alloys, the amorphous alloys become soft at certain regions during the ultrasonic hammering owing to the unique disordered structures, thereby resulting in the low-stress forming approach. In this work, a new acting mechanism was found between amorphous alloy and the high-frequency vibration, providing an efficient approach for the fabrication of amorphous alloy products. [ABSTRACT FROM AUTHOR]

One novel and eight known oxidatively rearranged cycloartane triterpenoids were isolated from the seeds of Pseudolarix amabilis. The structure of the new isolate was elucidated on extensive spectroscopic analyses. Results indicated that pseudolarolide Q (4) exhibited strong antimicrobial activity against Gram-positive Staphylococcus aureus and Candida albicans at the MICs of 6.08 and 24.32 μM, respectively. Pseudolarolide I (2) showed the 11β-HSD1 inhibitory property at the IC50 value of 34.5 nM. [ABSTRACT FROM AUTHOR]

A 1% Y and 1% Mn alternately doped nonstoichiometric (Ba0.6Sr0.4)0.8TiO3 (Y/Mn-BST) film was attempted to design and prepare by an improved sol-gel method on Pt/Ti/SiO2/Si substrates, and its ultralow dielectric loss with other dielectric properties was studied in this paper. Undoped, Y doped and Mn doped BST films were also compared. All films grow along (110) orientation and show polycrystalline cubic ABO3 perovskite structures. Pure film shows the weakest crystallization, while Y/Mn-BST film exhibits the strongest crystallization. Superfluous Ti acted as Ti doping makes B sites so saturated that superfluous Ti4+ ions have to enter A sites and first replace Sr2+ ions and then replace Ba2+ ions to show donor doping, thus result in the smallest lattice parameter and decreased Ba/Sr ratio. Doped Y3+ or Mn2+ ions only enter A sites and replace Ti4+ ions to reveal acceptor doping, and thuscause lattice parameters and Ba/Sr ratio a little larger than the undoped BST film. The Y/Mn-BST film shows the largest lattice parameter and increased Ba/Sr ratio with acceptor doping. Each nonstoichiometric BST film show smaller capacitance, tunability and dielectric loss than normal BST film, but the Y/Mn-BST film reveals better combination of dielectric properties in particular much smaller dielectric losses of 0.0051∼0.0067, thus show more obvious practicability and reliability in tunable microwave applications. [ABSTRACT FROM AUTHOR]

There has been no report on the influence of film growth behavior on the dielectric properties of BST films alternately doped with K and Mg up to now, thereby 1%K and 1%Mg alternately doped Ba0.6Sr0.4TiO3 (K/Mg-BST) films with various thicknesses were prepared by an improved sol-gel method, and their growth behaviors and dielectric properties were studied in this paper. The K/Mg-BST films were designed as KBST/MgBST/...multilayer films composed of 1∼8 layers with the first K doped BST layer (about 120nm/layer). 1, 3, 5 and 7-layer films were not annealed, while 2, 4, 6 and 8-layer films were annealed. 7 or 8-layer pure BST, Mg-BST, K-BST and Mg/K-BST (with the first Mg doped BST layer) films were compared. All films show ABO3 cubic perovskite polycrystalline structures and grow mainly along (110) orientation. The K/Mg-BST films show enhancing crystallizations but fluctuant lattice constants with increasing film thickness. However, the not annealed films show larger lattice constants than the annealed films, and Mg2+ ions tend to replace Ti4+ ions and show acceptor doping mechanism. K+ ions in the not annealed films have a tendency to substitute for Sr2+ ions, and in the annealed films tend to replace Ba2+ ions. Increasing film thickness promotes K+ ions replacing Sr2+ ions and Ba2+ ions, and causes acceptor doping mechanism. The Mg/K-BST films show island growth with the fastest speed, while the other films show layer growth. The K/Mg-BST films reveal the slowest growing speed, and increasing film thicknesses gradually improve surface morphologies, thus show better comprehensive dielectric properties than K or Mg-BST films. 7-layer and 8-layer K/Mg-BST films display excellent comprehensive dielectric properties, but 7-layer film is more suitable for tunable microwave applications owing to smaller capacitance. [ABSTRACT FROM AUTHOR]

A series of turning tests were conducted to investigate the cutting performance of ceramic tools in high-speed turning iron-based superalloys GH2132 (A286). Three kinds of ceramic tools, KY1540, CC650, and CC670 were used and their materials are Sialon,Al2O3–Ti(C,N), andAl2O3–SiCw, respectively. The cutting forces, cutting temperatures, tool wear morphologies, and tool failure mechanisms are discussed. The experimental results show that with the increase in cutting speed, the resultant cutting forces with KY1540 and CC670 tools show a tendency to increase first and then decrease while those for CC650 increase gradually. The cutting temperature increases monotonically with the increase in cutting speed. The optimum cutting speeds for KY1540 and CC650 when turning GH2132 are less than 100 m/min, while those for CC670 are between 100 and 200 m/min. Flank wear is the main reason that leads to tool failure of KY1540 and CC670 while notch wear is the main factor that leads to tool failure of CC650. Tool failure mechanisms of ceramic tools when machining GH2132 include adhesion, chipping, abrasion, and notching. Better surface roughness can be got using CC670 ceramic tools. [ABSTRACT FROM PUBLISHER]

Triple negative breast cancer (TNBC) presents clinical challenges due to unknown etiology, lack of treatment targets, and poor prognosis. We examined combined genetic and nutritional risk models of TNBC in 354 breast cancer cases. We evaluated 18 DNA-repair nonsynonymous single nucleotide polymorphisms (nsSNPs) and dietary/nutritional intakes. Multivariate Adaptive Regression Splines models were used to select nutrients of interest and define cut-off values for logistic regression models. Our results suggest that TNBC was associated with 6 DNA-repair nsSNPs,ERCC4 R415Q(rs1800067),MSH3 R940Q(rs184967),MSH6 G39E(rs1042821),POLD1 R119H(rs1726801),XRCC1 R194W(rs1799782), andXPC A499V(rs2228000) and/or deficiencies in 3 micronutrients (zinc, folate, and β-carotene). Combined analyses of these 6 nsSNPs and 3 micronutrients showed significant association with TNBC: odds ratios = 2.77 (95% confidence interval = 1.01–7.64) and 10.89 (95% confidence interval = 3.50–33.89) for 2 and at least 3 risk factors, respectively. To the best of our knowledge, this is the first study to suggest that multiple genetic and nutritional factors are associated with TNBC, particularly in combination. Our findings, if validated in larger studies, will have important clinical implication that dietary modulations and/or micronutrient supplementations may prevent or reverse TNBC phenotype, so tumors can be treated with less toxic therapeutic strategies, particularly in genetically susceptible women. [ABSTRACT FROM AUTHOR]

An off-lattice Monte Carlo model was developed to study the heat transfer in three-phase systems containing carbon nanotubes (CNTs) randomly orientated and distributed at the interface of another two media. Thermal energy was simulated by a large number of discrete thermal walkers with a random movement in the CNTs and a Brownian motion in the other two media. Thermal boundary resistances (TBRs) were calculated according to the Acoustic Mismatch theory and were applied in the simulation using the probabilities of the thermal walkers to travel across the interfaces. The numerical models were validated by comparing the simulation results with the theoretically calculated values for a spherical heat source. Using the current model, heat transfer properties with complex morphology of CNTs (diameter, orientations, and aspect ratio), as well as different heat sources, can be quantified. [ABSTRACT FROM PUBLISHER]

BACKGROUND: Enzymatical conversion of A or B RBCs into group O RBCs (ECORBCs) was achieved by using α-N-acetylgalactosaminidase and α-galactosidase, respectively. Now, we initiated AB to O-RBC conversion by using these two enzymes together. But α-N-acetylgalactosaminidase and α-galactosidase's preserving and their reaction buffer were quite different. The aim of this study is to confirm an available system for converting AB to O RBCs, especially to study the maximal permission amount of PCS which was brought to the system-accompanied enzyme addition. METHOD: Enzyme activity was detected by using GalNAc-pNp or Gal-pNp as substrates. The efficiency of the conversion of A or B antigen was evaluated by routine method and measured by fluorescence-activated cell sorting analysis. The optimal buffer component and the doses of α-N-acetylgalactosaminidase and α-galactosidase were confirmed according to A and B antigen epitope removal efficiency. RESULTS: The activity of α-N-acetylgalactosaminidase and a-galactosidase was not decreased drastically when they were kept in PCS Buffer in 4°C. The optimal reaction buffer composed of glycine 250 mM and NaCl 3 mM, pH 6.8 and PCS less than 10%(v/v). For converting A1B to O RBCs completely, the doses of α-N-acetylgalactosaminidase and a-galactosidase were confirmed as 0.015 mg/ml packed RBCs(pRBCs) for A1 antigen epitopes and 0.005 mg/ml pRBCs for B epitopes. Approximately 0.004 mg α-N-acetylgalactosaminidase and 0.005 mg α-galactosidase were required to convert 1 ml pRBCs. CONCLUSION: Our studies indicated that α-N-acetylgalactosaminidase and α-galactosidase were stable in PCS buffer and a modified protocol which was propitious to converting AB to O RBCs was provided. [ABSTRACT FROM AUTHOR]

Objective: To study the effect of hippocampal bone marrow stromal cells (GFP-BMSCs) transplantation on spatial memory and DeltaNp73 expression in APP/PS1 transgenic mice. Methods: Twelve APP/PS1 transgenic mice randomly received either 10 μl GFP-BMSCs suspension in medium (GFP-BMSCs transplantation group) or 10 μl complete medium (sham-operated group). Learning and memory function of mice in both groups were observed and tested in Morris water maze experiment at 2 weeks after surgery. Senile plaques and DeltaNp73 protein in hippocampuses were determined by immunohistochemistry and western blot at 3 weeks after surgery, respectively. Results: APP/PS1 mice treated with BMSCs performed significantly better on the water maze test than those in sham-operated group (P<0·05). Immunohistochemistry showed that GFP-BMSCs distributed uniformly and the number of Alzheimer's senile plaques reduced after transplantation. Western blot showed that quantified DeltaNp73 protein expression was significantly higher in BMSCs transplantation group when compared with sham-operated group (P<0·01). Conclusions: Our results suggest that BMSCs transplatation could retard Alzheimer's disease (AD) like pathology and upregulate DeltaNp73 expression in hippocampuses of APP/PS1 transgenic mice. GFP-BMSCs transplantation will be a potential treatment for AD. [ABSTRACT FROM AUTHOR]

An amphiphilic graft copolymer poly(vinyl alcohol)-g-poly(butyl acrylate) (PVA-g-PBA) was synthesized by grafting butyl acrylate (BA) onto poly(vinyl alcohol) (PVA) with potassium persulfate (KPS) as free radical initiator in N2 atmosphere and aqueous medium. The formation of graft copolymer was confirmed by means of infrared spectroscopy (IR). The influences of initiator, monomer concentration and reaction time on the percentage of monomer conversion(CM), graft degree(Gd) and graft efficiency(Ge) have been discussed in detail. PVA-g-PBA was used as compatibilizer in blends of chlorinated polyethylene (CPE)/ poly(acrylic acid-co-acrylamide)[P(AA-AM)], and the compatibility between CPE and P(AA-AM) was also investigated. [ABSTRACT FROM AUTHOR]

Microparts are more difficult to form than macroparts because of the size effect on material properties and the size effect on friction. Friction size effect was studied in this research. Cylinder compression was carried out with using lubrication talc powder, petroleum jelly, and soybean oil and without lubrication. The specimen material was copper alloy C3602 that was thermally treated at 623, 723, 823, and 923 K for 1 h in nitrogen atmosphere, respectively. The specimens were manufactured in an instrument lathe with initial diameters of 6, 4, 2, and 1 mm, respectively, and a height-to-diameter ratio h0/d0 = 1.5. The experiment was carried out at room temperature on a universal testing machine, and the strain rate ? = 0.0025 s-1. The results show that the friction size effect was obvious in the case of lubrication with soybean oil. The friction factor increased distinctly with the miniaturization of the specimen size. However, the friction size effect was not found in the case of other lubrication conditions. The reason for this phenomenon is also discussed in this article. [ABSTRACT FROM AUTHOR]

Graft of glycidyl methacrylate (GMA) onto solid-state chlorinated polyethylene (CPE) has been performed by suspension copolymerization in a complex dispersion medium which was a compound with H2O, ethyl acetate (EA) and tert-butyl alcohol (TBA). Benzoyl peroxide (BPO) was used as the free radical initiator. The graft level (graft degree and graft efficiency) was calculated gravimetrically, and the graft copolymer was characterized by infrared (IR) spectroscopy, thermogravimetric analysis (TGA) and contact angle study. The effects of reaction conditions on graft level, including chemical parameters (the concentration of monomer, initiator, and interfacial agent) and processing parameters (reaction time and temperature), have been investigated in detail. The experimental results showed that GMA could be grafted onto the chain of CPE with comparative higher graft degree, which could reach 37% with graft efficiency above 80%. [ABSTRACT FROM AUTHOR]

A new kind of copper(II) complex, CuL(MeOH) (H2L?=?( E )- N 1 -(2-((2-aminocyclohexydiimino)(phenyl)methyl)-4-chlorophenyl)- N 2 -(2-benzyl-4-chlorophenyl)oxalamide) has been synthesized and its structure determined by single-crystal X-ray methods. Copper(II) ion is five-coordinate, bonding to four nitrogen atoms from H2L and one oxygen atom from MeOH. Hydrogen bonds in the crystal result in the formation of a one-dimensional structure. EPR spectra are discussed. Computer simulation gave g||?=?2.200, g??=?2.002. On the basis of the synthesis and the crystal structure, the mechanism of the metal template reaction involved in the formation of the complex was verified. [ABSTRACT FROM AUTHOR]

Deubiquitination has emerged as an important mechanism of regulating DNA repair pathways. We recently reported that USP24 is a novel p53 deubiquitinase that stabilizes p53 upon DNA damage. USP24 is upregulated by DNA damaging agents and plays an important role in maintaining genome stability. [ABSTRACT FROM AUTHOR]