An outbreak of ammonia poisoning from chicken tenders served in a school lunch

Although foodborne outbreaks of illness are relatively common, they are rarely caused by chemical agents. An outbreak of gastrointestinal illness occurred among students at two schools shortly after lunch was served. A cohort study, an environmental investigation, and microbiological and toxicological laboratory testing of food samples were performed. A case was defined as a student or teacher who ate food prepared in the kitchen at school A on 25 November 2002 (and served at schools A and B) and who later developed headache or symptoms of gastrointestinal tract irritation, with onset within 180 min of eating lunch. Among 312 persons interviewed, 157 persons became ill (attack rate = 49%; attack rate 41% for school A, 11% for school B). Onset of illness occurred within 60 min for 81% of cases; 91% of students reported that their chicken tenders smelled unusual. Eating chicken tenders that smelled unusual was associated with being a case (relative risk 9.2, 95% confidence interval 1.4 to 62.6, P < 0.05). Ammonia was detected in uncooked chicken tenders at levels as high as 2,468 ppm. The chicken had been contaminated during a warehouse leak of ammonia refrigerant. This outbreak of ammonia poisoning is only the second reported in food, and the first in a solid food. Heated chicken tenders contaminated with ammonia can cause acute illness within a short period of time.     

Synergistic blends of natural polymers,pectin and sodium alginate

A wide range of Pectin and Sodium Alginate blends have been investigated by casting films from aqueous solution. Blends showed synergy both in mechanical properties and water vapor permeation rate. Previously observed synergism in gels at low pH is also maintained in cast films of blends having up to 40% Pectin. Films were made water‐insoluble by post‐treatment with CaCl₂, which develops physical crosslinks among the molecules of both polymers. After CaCl₂ treatment, mechanical properties are drastically changed due to development of physically crosslinked tie points in the molecular network structure. The modulus and tensile strength of the resulting network structure are dependent on the nature of the polymers. Even in water insoluble films, synergism in mechanical and water barrier properties is retained in films having up to 20% Pectin content. Structural reorganization before and after CaCl₂ treatment was investigated by X‐ray and dynamic mechanical analysis. The synergism observed in mechanical properties of the films before and after CaCl₂ treatment is attributed to reduction in molecular mobility and change in molecular network structure. Structural reorganization in CaCl₂‐treated films, and thereby film properties, is dependent on the compositions of the blends; blended films show sharp glassy‐rubbery transition in the storage modulus—temperature plot, which is not the case in untreated films. Film flexibility increases with increasing Pectin content in the blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Fibrillar Growth of Amylose Acetate and Other Polymers

Fibrillar crystals of amylose acetate have been grown in different conditions of growth using film formation method of crystal growth. For generalization of fibrillar growth conditions, crystals of cellulose triacetate, polyoxymethylene and polyacrylonitrile have been grown and compared with the fibrillar crystal growth habit of amylose acetate. The type of fibrillar aggregation is dependent on type of solvent, concentration of polymer and crystallization temperature. Various growth stages of features are shown in order to understand their growth mechanismus. It is proposed that the fibrils are the fundamental units of most polymer crystallization processes and fibrous crystal growth is as common as the frequently observed lamellar growth of polymer crystals. The most common features of the fibres are the twisting and branching habit which can be compared with the morphology of fibres of natural polymers.     

Pre-qualification of brazed plasma facing components of divertor target elements for ITER like tokamak application

Qualification of tungsten (W) and graphite (C) based brazed plasma facing components (PFCs) is an important R&D area in fusion research. Pre-qualification tests for brazed joints between W–CuCrZr and C–CuCrZr using NDT (IR thermography and ultrasonic test) and thermal fatigue test are attempted. Mockups having good quality brazed joints of W and C based PFCs were identified using NDT. Subsequently, thermal fatigue test was performed on the identified mockups. All brazed tiles of W based PFC mockups could withstand thermal fatigue test, however, few tiles of C based PFC mockup were found detached. Thermal analyses of mockups are performed using finite element analysis (ANSYS) software to simulate the thermal hydraulic condition with 10 MW/m² uniform heat flux. Details about experimental and computational work are presented here.     

Analysis of the human hephaestin gene and protein: comparative modelling of the N-terminus ecto-domain based upon ceruloplasmin

Hephaestin was implicated in mammalian iron homeostasis followingits identification as the defective gene in murine sex-linkedanaemia. It is a member of the family of copper oxidases thatincludes mammalian ceruloplasmin, factors V and VIII, yeastfet3 and fet5 and bacterial ascorbate oxidase. Hephaestin isdifferent from ceruloplasmin, a soluble ferroxidase, in havinga membrane-spanning region towards the C-terminus. Here we reportthe gene structure, spanning ~100 kb, of the human homologueof mouse hephaestin. The sequence was assembled from the cDNAclones and the chromosome X genomic sequence data availableat the Sanger Centre. It has an open reading frame that encodesa protein of 1158 residues, 85% identical with the murine homologue.A model of the N-terminal ecto-domain has been built based onthe known three-dimensional structure of human ceruloplasmin.The overall tertiary structure for the hephaestin and the putativeresidues involved in binding copper and iron appear to be highlyconserved between these proteins, which suggests they sharethe same fold and a conserved function.     

Morphology-property relationships in oriented PET films: A role of in-plane crystalline orientation distribution on the film properties

The role of in-plane crystalline, amorphous, and overall molecular orientation on various properties in the plane of the films was investigated using a variety of techniques. It is shown that for a fixed value of crystallinity the in-plane crystalline orientation and the nature of the constraint imposed by the crystallites on the molecules play an important role in obtaining isotropic in-plane expansion or shrinkage properties. Achievement of in-plane isotropic tensile strength and elongation at the break are found to depend entirely upon an isotropic distribution of the amorphous orientation; the orientation of crystallites plays no detectable role. Furthermore, the deformation mechanisms of sequential and simultaneous biaxial stretching processes have been investigated and compared. The simulteneous stretching process is considered to be a more controlled film-fabricating method compared to sequential stretching in achieving balanced, in-plane film properties. © 1993 John Wiley & Sons, Inc.     

Universal, geometry-driven hydrophobic behaviour of bare metal nanowire clusters

A parallel array of isolated metal nanowires is expected to be hydrophilic. We show, however, that a clustering of such nanowires brought about by vacuum drying produces a 'dual-scale roughness' and confers a strongly hydrophobic property to the surface. The mean size of the nanowire clusters as well as the contact angle are both found to be related to the wire length, and the critical wire length above which the surface becomes hydrophobic is ≈10?μm. Surface roughness is generally known to enhance water-repellent properties, but this is the first report of roughness-induced hydrophobicity on a bare (uncoated) metallic surface.     

Discovering known and unanticipated protein modifications using MS/MS database searching

We present an MS/MS database search algorithm with the following novel features: (1) a novel protein database structure containing extensive preindexing and (2) zone modification searching, which enables the rapid discovery of protein modifications of known (i.e., user-specified) and unanticipated delta masses. All of these features are implemented in Interrogator, the search engine that runs behind the Pro ID, Pro ICAT, and Pro QUANT software products. Speed benchmarks demonstrate that our modification-tolerant database search algorithm is 100-fold faster than traditional database search algorithms when used for comprehensive searches for a broad variety of modification species. The ability to rapidly search for a large variety of known as well as unanticipated modifications allows a significantly greater percentage of MS/MS scans to be identified. We demonstrate this with an example in which, out of a total of 473 identified MS/MS scans, 315 of these scans correspond to unmodified peptides, while 158 scans correspond to a wide variety of modified peptides. In addition, we provide specific examples where the ability to search for unanticipated modifications allows the scientist to discover: unexpected modifications that have biological significance; amino acid mutations; salt-adducted peptides in a sample that has nominally been desalted; peptides arising from nontryptic cleavage in a sample that has nominally been digested using trypsin; other unintended consequences of sample handling procedures.     

Enhanced visible-light photoresponse of DVT-grown Ni-doped SnSe crystal

Semiconductors with the group of IV-VI are key components of future photonics technology due to their unique properties. In the present study, we investigated the influence of nickel inclusion on the structural and electrical responsiveness of SnSe-layered crystals produced through direct vapour transport. The elemental composition, stoichiometry of grown crystals and the orthorhombic structure were investigated by EDAX and XRD analysis. The phase and high crystallinity of produced compounds are revealed by scanning electron microscopy and the SAED pattern of transmission electron microscopy. Nickel-doped SnSe photodetector exhibited a photocurrent of 53.83 nA, which is six times higher compared to the pristine SnSe. Moreover, the pristine and nickel-doped SnSe demonstrated excellent photoresponse behaviour under visible light. Additionally, important photodetection characteristics such as photoresponsivity (R), spectral detectivity (D), rise time and decay time are assessed. Our findings contribute to a better understanding of SnSe and Ni-doped SnSe-based photodetection capabilities which open up the future gateway for SnSe-based optoelectronic devices.