Ashkin-Teller criticality and weak first-order behavior of the phase transition to a fourfold degenerate state in two-dimensional frustrated Ising antiferromagnets

We study the thermal phase transition of the fourfold degenerate phases (the plaquette and single-stripe states) in the two-dimensional frustrated Ising model on the Shastry-Sutherland lattice using Monte Carlo simulations. The critical Ashkin-Teller-like behavior is identified both in the plaquette phase region and the single-stripe phase region. The four-state Potts critical end points differentiating the continuous transitions from the first-order ones are estimated based on finite-size-scaling analyses. Furthermore, a similar behavior of the transition to the fourfold single-stripe phase is also observed in the anisotropic triangular Ising model. Thus, this work clearly demonstrates that the transitions to the fourfold degenerate states of two-dimensional Ising antiferromagnets exhibit similar transition behavior.

Directed Self-Assembly of Polystyrene-b-poly(propylene carbonate) on Chemical Patterns via Thermal Annealing for Next Generation Lithography

Directed self-assembly (DSA) of block copolymers (BCPs) combines advantages of conventional photolithography and polymeric materials and shows competence in semiconductors and data storage applications. Driven by the more integrated, much smaller and higher performance of the electronics, however, the industry standard polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) in DSA strategy cannot meet the rapid development of lithography technology because its intrinsic limited Flory-Huggins interaction parameter (χ). Despite hundreds of block copolymers have been developed, these BCPs systems are usually subject to a trade-off between high χ and thermal treatment, resulting in incompatibility with the current nanomanufacturing fab processes. Here we discover that polystyrene-b-poly(propylene carbonate) (PS-b-PPC) is well qualified to fill key positions on DSA strategy for the next-generation lithography. The estimated χ-value for PS-b-PPC is 0.079, that is, two times greater than PS-b-PMMA (χ = 0.029 at 150 °C), while processing the ability to form perpendicular sub-10 nm morphologies (cylinder and lamellae) via the industry preferred thermal-treatment. DSA of lamellae forming PS-b-PPC on chemoepitaxial density multiplication demonstrates successful sub-10 nm long-range order features on large-area patterning for nanofabrication. Pattern transfer to the silicon substrate through industrial sequential infiltration synthesis is also implemented successfully. Compared with the previously reported methods to orientation control BCPs with high χ-value (including solvent annealing, neutral top-coats, and chemical modification), the easy preparation, high χ value, and etch selectivity while enduring thermal treatment demonstrates PS-b-PPC as a rare and valuable candidate for advancing the field of nanolithography.

Cytotoxicity evaluation of the whole protein extract from Bar-transgenic rice on Mus musculus lymphocytes

With the expanding demand for genetically modified (GM) rice, its safety evaluation is of great significance. Therefore, this study was carried out to assess the acute cytotoxicity of the whole protein extract from GM rice Bar68-1 in Mus musculus lymphocytes in vitro. Cell viability was determined by Cell Counting Kit-8 (CCK-8) and Neutral Red Uptake (NRU) tests. CCK-8 tests was carried out according to the manufacturer's instructions. Cell dehydrogenase (catalytic redox enzymes) activity was spectrophotometrically determined at 450 nm. The tests result were recorded immediately. NRU tests were completed under yellow light in a dark room according to an improved protocol. Lysosomal uptake of neutral red was spectrophotometrically determined at 540 nm and the results were recorded immediately. The results showed that the survival rate of M. musculus lymphocytes in the positive control group was significantly less than in the blank control group (P < 0.05). Moreover, an exposure- time-effect relationship was observed in the positive control group with CCK-8 and NRU tests. There was no significant difference in survival rate between GM rice Bar68-1group and non-GM rice D68 group (P > 0.05). The GM rice Bar68-1 group also did not show a higher survival rate than non-GM rice D68 group (P > 0.05). These results suggested that the whole protein extract from Bar68-1 and D68 were equivalent in their cytotoxicity, and GM rice Bar68-1 had no acute cytotoxic effect on M. musculus lymphocytes in vitro.

Biosynthesis and Regulation of Wheat Amylose and Amylopectin from Proteomic and Phosphoproteomic Characterization of Granule-binding Proteins

Waxy starch has an important influence on the qualities of breads. Generally, grain weight and yield in waxy wheat (Triticum aestivum L.) are significantly lower than in bread wheat. In this study, we performed the first proteomic and phosphoproteomic analyses of starch granule-binding proteins by comparing the waxy wheat cultivar Shannong 119 and the bread wheat cultivar Nongda 5181. These results indicate that reduced amylose content does not affect amylopectin synthesis, but it causes significant reduction of total starch biosynthesis, grain size, weight and grain yield. Two-dimensional differential in-gel electrophoresis identified 40 differentially expressed protein (DEP) spots in waxy and non-waxy wheats, which belonged mainly to starch synthase (SS) I, SS IIa and granule-bound SS I. Most DEPs involved in amylopectin synthesis showed a similar expression pattern during grain development, suggesting relatively independent amylose and amylopectin synthesis pathways. Phosphoproteome analysis of starch granule-binding proteins, using TiO2 microcolumns and LC-MS/MS, showed that the total number of phosphoproteins and their phosphorylation levels in ND5181 were significantly higher than in SN119, but proteins controlling amylopectin synthesis had similar phosphorylation levels. Our results revealed the lack of amylose did not affect the expression and phosphorylation of the starch granule-binding proteins involved in amylopectin biosynthesis.

Effect of further-neighbor interactions on the magnetization behaviors of the Ising model on a triangular lattice

In this work, we study the magnetization behaviors of the classical Ising model on the triangular lattice using Monte Carlo simulations, and pay particular attention to the effect of further-neighbor interactions. Several fascinating spin states are identified to be stabilized in certain magnetic field regions, respectively, resulting in the magnetization plateaus at 2/3, 5/7, 7/9 and 5/6 of the saturation magnetization M S, in addition to the well-known plateaus at 0, 1/3 and 1/2 of M S. The stabilization of these interesting orders can be understood as the consequence of the competition between Zeeman energy and exchange energy.

Asymmetric Alternating Copolymerization of Meso-epoxides and Cyclic Anhydrides: Efficient Access to Enantiopure Polyesters

Synthesis of stereoregular polyesters with main-chain chirality was achieved for the first time by the asymmetric copolymerization of meso-epoxides and cyclic anhydrides using catalyst systems based on enantiopure bimetallic complexes. The combination of the biphenol-linked dinuclear aluminum complex with tert-butyl groups in the phenolate ortho-positions and a nucleophilic co-catalyst was found to be more efficient in catalyzing this asymmetric copolymerization, affording enantiomerically enriched polyesters (up to 91% ee) with completely alternating structure and narrow molecular weight distribution. It was discovered that the isotactic-enriched poly(cyclopentene phthalate) is a typical semicrystalline material with a melting endothermic peak at 221 °C. This study is expected to provide a promising route to prepare various stereoregular polyesters having a wide variety of physical properties and degradability.

Preferential combination between the light and heavy chain isotypes of fish immunoglobulins

Immunoglobulin light chain (IgL) is necessary for the assembly of an Ig molecule, which plays important roles in the immune response. IgL genes were identified in various teleost species, but the basic functions of different IgL isotypes and the preferential combination between IgL and IgH (Ig heavy chain) isotypes remain unclear. In the current study, by EST database searching and cDNA cloning in rainbow trout, 8 IgL sequences were obtained, which could be classified into the IgLκF, IgLκG, IgLσ and IgLλ isotypes, respectively. Trout IgL isotypes were highly expressed in the immune-related tissues, and participated in the immune responses in spleen and gut by stimulation with LPS and poly (I:C). The results of FACS and LC-MS/MS indicated that the IgLκG and IgLσ isotypes preferentially bonded with the heavy chains of IgM and IgT, respectively, in trout B cells and serum. In addition, the genomic organization of trout IgL isotypes and the utilization of recombination signal sequences were studied.

Dynamic activity of NF-kappaB in multiple trauma patients and protective effects of ulinastain

OBJECTIVE

To investigate the dynamic activity of NF-kappaB at the early stage of injury in multiple trauma patients and the protective effects of ulinastain.

METHODS

From January 2008 to May 2010, patients with multiple traumas admitted to our emergency department were enrolled in this study. Their age varied from 20-55 years. All enrolled patients were assigned randomly into control group (26 cases of multiple injury without ulinastain treatment), ulinastain group (25 cases of multiple injury with ulinastain treatment), and mild injury group (20 cases) for basic control. The inclusion criteria for mild injury group were AIS-2005 less than or equal to 3, single wound, previously healthy inhospital patients without the history of surgical intervention. In addition to routine treatment, patients in ulinastain group were intravenously injected 200 000 IU of ulinastain dissolved in 100 ml of normal saline within 12 hours after injury and subsequently injected at the interval of every 8 hours for 7 days. NF-kappaB activity in monocytes and the level of TNF-alpha,IL-1, IL-6 in serum on admission (day 0), day 1, 2, 3, 4, and 7 were measured. Data were compared and analyzed between different groups.

RESULTS

NF-kappaB activity in monocytes and TNF-alpha,IL-1 and IL-6 of these patients reached peak levels at 24 hour after trauma, with gradual decrease to normal at 72 hour after trauma. NF-kappaB activity and levels of TNF-alpha,IL-1 and IL-6 were lower in ulinastain group than control one, without any significant difference between the two groups. The mean duration for systemic inflammatory response syndrome and multiple organ dysfunction syndrome was 7 d+/-3.1 d and 10 d+/-3.5 d in ulinastain group and control group respectively, and showed a significant difference.

CONCLUSIONS

NF-kappaB activity in monocytes and the levels of inflammatory cytokines in multiply injured patients increased transiently at the early stage of trauma. Ulinastain may shorten the duration of systemic inflammatory response syndrome and multiple organ dysfunction syndrome, but does not show the ability to decrease the activity of NF-kappaB .

Spring Viremia of Carp Virus N Protein Suppresses Fish IFNφ1 Production by Targeting the Mitochondrial Antiviral Signaling Protein

For a virus to replicate efficiently, it must try and inhibit host IFN expression because IFN is an important host defense at early stages after viral infection. For aquatic viruses, the mechanisms used to escape the hosts IFN system are still unclear. In this study, we show that the N protein of spring viremia of carp virus (SVCV) inhibits zebrafish IFNφ1 production by degrading the mitochondrial antiviral signaling protein (MAVS). First, the upregulation of IFNφ1 promoter activity stimulated by polyinosinic:polycytidylic acid, retinoic acid-inducible gene I (RIG-I) or MAVS was suppressed by the SVCV infection. However, the upregulation by the downstream factor of the RIG-I-like receptor signaling pathway, TANK-binding kinase 1, was not affected. Notably, at the protein level, MAVS decreased remarkably when cells were infected with SVCV. Second, consistent with the result of the SVCV infection, overexpression of the N protein of SVCV blocked the IFNφ1 transcription activated by MAVS and downregulated MAVS expression at the protein level but not at the mRNA level. Further analysis demonstrated that the N protein targeted MAVS for K48-linked ubiquitination, which promoted the degradation of MAVS. These data indicated that fish MAVS could be degraded by the N protein of SVCV through the ubiquitin-proteasome pathway. To our knowledge, this is the first article of a fish RIG-I-like receptor pathway interfered by an aquatic virus in an ubiquitin-proteasome manner, suggesting that immune evasion of a virus also exists in lower vertebrates.

Role of further-neighbor interactions in modulating the critical behavior of the Ising model with frustration

In this work, we investigate the phase transitions and critical behaviors of the frustrated J(1)-J(2)-J(3) Ising model on the square lattice using Monte Carlo simulations, and particular attention goes to the effect of the second-next-nearest-neighbor interaction J(3) on the phase transition from a disordered state to the single stripe antiferromagnetic state. A continuous Ashkin-Teller-like transition behavior in a certain range of J(3) is identified, while the four-state Potts-critical end point [J(3)/J(1)](C) is estimated based on the analytic method reported in earlier work [Jin, Sen, and Sandvik, Phys. Rev. Lett. 108, 045702 (2012)]. It is suggested that the interaction J(3) can tune the transition temperature and in turn modulate the critical behaviors of the frustrated model. Furthermore, it is revealed that an antiferromagnetic J(3) can stabilize the staggered dimer state via a phase transition of strong first-order character.

Synthesis and catalytic application of N-heterocyclic carbene copper complex functionalized conjugated microporous polymer

The first example of IPr(CuCl) functionalized conjugated microporous polymer has been synthesized and applied for the hydrosilylation of terminal alkynes and hydrosilylation of CO₂. Good catalytic activities and catalytic stability have been achieved.

Double carboxylation of o-alkynyl acetophenone with carbon dioxide

A copper-catalyzed double carboxylation of o-alkynyl acetophenone using carbon dioxide via a carboxylation/intramolecular cyclization/second carboxylation sequence to afford 1(3H)-isobenzofuranylidene dicarboxylic esters in good yields is developed.