Folding motifs induced and stabilized by distinct cystine frameworks

To whom correspondence should be addressed Bioactive peptides of different sources and biological functionalities, like endothelins, sarafotoxins, bee and scorpion venom toxins, contain a consensus cystine framework, Cys-(X)1-Cys/Cys-(X)3-Cys, which has been found to induce and stabilize a homologous folding motif named the cystine- stabilized alpha-helix (CSH). This is composed of an alpha-helical segment spanning the Cys-(X)3-Cys sequence portion that is crosslinked by two disulfide bridges to the sequence portion Cys-(X)1-Cys, itself folded in an extended beta-strand type structure. Search for sequence homologies of peptides and proteins in the SWISS-PROT and PDB data banks provided additional multiple examples of this type of cystine framework in serine proteinase inhibitors, in insect and plant defense proteins, as well as in members of the growth factor family with the cystine-knot. A comparative analysis of the known 3D-structures of these peptides and proteins confirmed that the presence of this peculiar cystine framework leads in all cases to a high degree of local structural homology that consists of the CSH motif, except for the cystine-knot, of the superfamily of the growth factors. In this case the cyclic structure formed by the parallel cysteine connectivities of Cys-(X)1-Cys/Cys-(X)3-Cys framework is penetrated by a third disulfide bond with formation of a concatenated knot, and the two disulfide- bridged peptide chains Cys-(X)1-Cys and Cys-(X)3-Cys are located in beta-strands. Conversely, peptides and proteins containing Cys-(X)m- Cys/Cys-(X)n-Cys cystine frameworks that differ from m/n = 1/3 were found to fold only sporadically into local alpha-helical structures.      

Expression of tropomyosin alpha 4 chain is increased in esophageal squamous cell carcinoma as evidenced by proteomic profiling by two-dimensional electrophoresis and liquid chromatography-mass spectrometry/mass spectrometry

To identify proteins associated with esophageal carcinogenesis, we performed protein profiling of 16 esophageal squamous cell carcinomas (ESCCs) and paired noncancerous tissues by 2-DE and MS/MS. In cancerous tissues, three spots showed significant up-regulation in the amount of protein, while eight spots were significantly down-regulated. The identities of the spots were determined by PMF with LC-MS/MS and were confirmed by immunoblotting. The up-regulated proteins were tropomyosin alpha 4 chain, transgelin, and pyruvate kinase. The down-regulated proteins were serum albumin precursor, isoforms of annexin A1, tropomyosin beta chain, 14-3-3 protein sigma, and isoforms of serotransferrin precursor. In all 16 cases, up-regulation of the tropomyosin alpha 4 chain was confirmed by immunoblotting. Localization of the tropomyosin alpha 4 chain in ESCC cells and adjacent fibroblasts was confirmed by immunohistochemistry.     

A unified approach to reducts in dominance-based rough set approach

The Dominance-based Rough Set Approach (DRSA), which is an extension of the Rough Set Approach (RSA), analyzes a sorting problem for a given data set. Attribute reduction is one of major topics in RSA as well as DRSA. By attribute reduction, we can find an important attribute set, which is called a reduct. In this paper, we propose a new approach to reducts in DRSA. A few kinds of reducts have been already proposed in DRSA, therefore, we clarify relations among the proposed and previous ones. We prove that they are consolidated into four kinds. Moreover, we show that all kinds of reducts can be enumerated based on two discernibility matrices.     

Balanced Secure Scan: Partial Scan Approach for Secret Information Protection

Scan-based Design-for-Testability technique is widely used to enhance the testability. However, it increases the vulnerability to attacks through scan chains for secure chips such as cryptographic circuits with embedded secret keys. This paper proposes a secure scan design method which protects the circuits containing secret information such as cryptographic circuits from scan-based side channel attacks. The proposed method prevents the leakage of secret information by partial scan design based on a balanced structure. We also guarantee the testability of both the design under test and DFT circuitry, and therefore, realize both security and testability. Experiments for RSA circuit shows the effectiveness of the proposed method.     

Structural and Textural Quality of Kinu-Tofu Frozen-then-Thawed at High-Pressure

To determine effects of high-pressure thawing on quality of high-pressure frozen tofu, kinu-tofu (soybean curd) was frozen 90 min at ca ?20°C at 100 MPa (ice I), 200 MPa (liquid phase), 340 MPa (ice III), 400, 500 or 600 MPa (ice V), then thawed at the same pressure. Texture and structure of this tofu (D) were compared with high-pressure-frozen tofu thawed at atmospheric pressure (A: 90 min frozen; B: 90 min frozen then 2 days at ?30°C; C: 160 min frozen). When tofu was frozen at 200- 500 MPa, ice crystals were largest to smallest in B > A and C > D; pore size of D was the same as untreated tofu. Results indicated ice crystals never grew when frozen at 200–500 MPa. Growth occurred during reduction of pressure at ca ?20°C, frozen storage or while thawing at atmospheric pressure due to phase transition.     

Polyvinylphosphonic acid copolymer hydrogels prepared with amide and ester type crosslinkers

Crosslinked hydrogels made of poly(vinylphosphonic acid‐co‐N,N′‐methylenebisacrylamide) (P(VPA‐co‐MBAA)) and poly(vinylphosphonic acid‐co‐ethyleneglycol diacrylate) (P(VPA‐co‐EGDA)) were prepared by using precipitation polymerization in water medium. A comparison research was made between the resultant hydrogels containing different loads of vinylphosphonic acid segments when N,N′‐methylenebisacrylamide (MBAA) or ethyleneglycol diacrylate (EGDA) were used as comonomers. Morphological observations indicated that the resultant copolymer appeared as a fine powder at low VPA loadings and strongly aggregated at the high loadings; especially, a copolymer containing 63 mol % of VPA segments in P(VPA‐co‐MBAA) was observed to have a flake‐shaped appearance in its aggregated morphology. The resultant copolymer powders were characterized using FTIR spectroscopy and titrimetric analysis. Also, monomer reactivity ratios, r₁ and r₂, of VPA and MBAA or EGDA were estimated as 0.06 and 0.98 for VPA and MBAA and 0.05 and 1.82 for VPA and EGDA, respectively. This suggested that a large distribution of MBAA and EGDA was present in the resultant copolymer powders. Their crosslinked PVPA structure presented hydrogel properties having high water uptakes and an absorption mechanism independent from pH of bulk solution. The evidence showed that high VPA loadings could strongly interacted through hydrogen bonds between neighbor VPA segments even in the presence of water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effects of annealing ambient on ferroelectric properties and surface chemistry of sol–gel derived Bi3.25La0.75Ti3O12 thin films

In this work, Bi_3.25La_0.75Ti₃O₁₂ (BLT) thin films were prepared by sol–gel coatings followed by rapid thermal annealing in Ar or O₂ ambient. The correlation among annealing ambient, ferroelectric characteristics and surface chemistry of the BLT thin films were investigated. The BLT thin film annealed in Ar showed weaker crystallization, less dense surface and smaller polarization value than that annealed in O₂. After 10⁹ cycles, the remnant polarization of the BLT film annealed in Ar decreased to 83.5 % of the initial value while it remained 89.5 % for the sample annealed in O₂. X-ray photoelectron spectroscopy results indicated the inferior fatigue characteristics of the sample annealed in Ar was the comprehensive result of oxygen vacancies vicinity to Bi and Ti ion in the thin film.     

Polymerization of ethylene using zirconocenes supported on swellable cation-exchanged fluorotetrasilicic mica

Supported catalysts consisting of Cp₂ZrCl₂ and cation-exchanged fluorotetrasilicic mica (Mⁿ⁺-mica, Mⁿ⁺ = Na⁺, Mg²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺) were prepared and employed in the ethylene polymerization or ethylene/1-hexene copolymerization in the presence of R₃Al. The catalysts consisting of swellable Mg²⁺-mica and Zn²⁺-mica (both calcined at 200 °C) and Cp₂ZrCl₂ displayed high activity for the polymerization reaction. By contrast, when Mg²⁺-mica and Zn²⁺-mica were calcined above 250 °C, the swellability was lost, and the activities of Cp₂ZrCl₂ supported on these non-swellable micas were significantly reduced. The relationship between the activity and swellability of mica was clearly observed both in ethylene polymerizations employing (n-BuCp)₂ZrCl₂ in place of Cp₂ZrCl₂ and in ethylene/1-hexene copolymerizations using Cp₂ZrCl₂. The role of Mⁿ⁺-mica for the activation of the metallocene complex was investigated by surface observation using a scanning electron microscope and by XRD measurements of the catalysts after polymerization of ethylene for a short time. The results of the surface observations indicated that polyethylene was produced on the edges of Mⁿ⁺-mica lamellas at the initial stage of the polymerization. The XRD measurements show that the regularity of the stacked lamellas was immediately lost at this stage. The catalyst prepared by removing free Cp₂ZrCl₂ (i.e., unsupported Cp₂ZrCl₂, Cp₂ZrCl₂ dissolved into the catalyst slurry) showed extremely low activity, suggesting that the most of the active sites were formed through the reactions of Mⁿ⁺-mica and free Cp₂ZrCl₂. These results indicate that the lamellas of Mⁿ⁺-mica are peeled off at the initial stage of the polymerization and that exposed metal cations react with free-Cp₂ZrCl₂ to form additional active species. The swellability of Mⁿ⁺-mica strongly affects the formation of additional active sites, and therefore the supported catalysts based on non-swellable Mⁿ⁺-mica displayed only low activities.     

Experimental study on TNF-alpha linked percutaneous isolated hepatic chemoperfusion (PIHP)]

BACKGROUND: This study aimed to establish perceptions of informed consent in patients undergoing surgery for acute abdominal conditions. METHODS: A prospective observational study was carried out using a structured questionnaire-based interview technique in patients undergoing surgery for acute abdominal conditions. Main outcome measures were to establish the effects of pain and preoperative analgesia on informed consent, patient comprehension of planned surgery and the degree of discussion of potential side-effects and complications. RESULTS: Thirty-one of 49 patients perceived that pain did not interfere with their ability to give informed consent. Forty of 48 stated that preoperative analgesia did not impair their ability to give informed consent. Forty-two understood why an operation was being planned but 28 patients stated that there had been no preoperative discussion of any potential side-effects or complications of surgery. CONCLUSION: In this study the majority of patients perceived that they retained the ability to give informed consent despite the effects of pain and analgesia. Although the majority of patients understood why an operation was being planned there is a clear need for improved discussion of potential side-effects and complications.