Common core structure of amyloid fibrils by synchrotron X-ray diffraction

Tissue deposition of normally soluble proteins as insoluble amyloid fibrils is associated with serious diseases including the systemic amyloidoses, maturity onset diabetes, Alzheimer's disease and transmissible spongiform encephalopathy. Although the precursor proteins in different diseases do not share sequence homology or related native structure, the morphology and properties of all amyloid fibrils are remarkably similar. Using intense synchrotron sources we observed that six different ex vivo amyloid fibrils and two synthetic fibril preparations all gave similar high-resolution X-ray fibre diffraction patterns, consistent with a helical array of beta-sheets parallel to the fibre long axis, with the strands perpendicular to this axis. This confirms that amyloid fibrils comprise a structural superfamily and share a common protofilament substructure, irrespective of the nature of their precursor proteins.     

Probabilistic model for pitting of copper canisters

Copper canisters for the final disposal of spent nuclear fuel are expected to be subject to general (uniform) corrosion and a limited degree of localised damage. Although the canister is expected to be exposed to predominantly active conditions, it is nevertheless prudent to assess the probability of pitting corrosion in passive conditions. A probabilistic pitting model is developed for aerobic conditions in water-saturated bentonite. While aerobic, saturated conditions may be unlikely to occur if saturation is slow or O₂ consumption is fast, these conditions have been assumed as a starting point because of the availability of data. The model samples from environmental conditions use a Monte Carlo approach to predict active or passive conditions. Under passive conditions, the model compares corrosion potentials to breakdown and repassivation potentials to determine pit initiations and deaths, respectively. Pit depth distributions can then be calculated. For the assumed conditions, the model predicts that active conditions dominate 90% of the time while the remaining passive conditions can lead to pitting during the first few years primarily controlled by the availability of oxygen.     

Specific developmental disorders. The language-learning continuum

The goal of this article is to inform and educate those who work with children who present with language-learning disorders about phonologic processing deficits, because this area has been shown to have a significant impact on children and adults who exhibit reading disabilities. Mental health professionals who work with children with reading problems need to be aware of what is known about this source of reading disorders and the implications of this knowledge for prevention and treatment. Advocating for appropriate instruction for children with reading problems is an important role mental health professionals can play in working with this population.     

Early syphilis in an active duty military population and the surrounding civilian community, 1985-1993

The study of human aggression has been hindered by the lack of reliable and valid diagnostic categories that specifically identify individuals with clinically significant displays of impulsive aggressive behavior. DSM intermittent explosive disorder (IED) ostensibly identifies one such group of individuals. In its current form, IED suffers from significant theoretical and psychometric shortcomings that limit its use in clinical or research settings. This study was designed to develop a revised criteria set for IED and present initial evidence supporting its reliability and validity in a well characterized group of personality disordered subjects. Accordingly, research criteria for IED-Revised (IED-R) were developed. Clinical, phenomenologic, and diagnostic data from 188 personality disordered individuals were reviewed. IED-R diagnoses were assigned using a best-estimate process. The reliability and construct validity of IED-R were examined. IED-R diagnoses had high interrater reliability (kappa = .92). Subjects meeting IED-R criteria had higher scores on dimensional measures of aggression and impulsivity, and had lower global functioning scores than non-IED-R subjects, even when related variables were controlled. IED-R criteria were more sensitive than DSM-IV IED criteria in identifying subjects with significant impulsive-aggressive behavior by a factor of four. We conclude that in personality disordered subjects, IED-R criteria can be reliably applied and appear to have sufficient validity to warrant further evaluation in field trials and in phenomenologic, epidemiologic, biologic, and treatment-outcome research.     

Employee drug use, demographic characteristics, work reactions, and absenteeism.

Investigated the relationships between employee use of illicit drugs, perceptions of and reactions to the work environment, and employee absenteeism and tardiness above and beyond that accounted for by demographic and work reaction variables. 162 employees in a large work organization completed demographic and background information and assessments of work perceptions and reactions and absenteeism and tardiness. Drug use was assessed with a questionnaire and urine testing. Employee drug use accounted for additional statistically significant variance in overall absenteeism and in absenteeism due to injuries and suspensions, as well as days tardy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mucosal and systemic antibody responses to a C4/V3 construct following DNA vaccination of rabbits via the Peyer's patch

A plasmid encoding T1-SP10MN(A), a peptide derived from immunodominant regions of human immunodeficiency virus type 1 gp120, was delivered to rabbit Peyer's patches using a helium-driven gene gun. Six weeks thereafter, 2 of 5 animals were given an intradermal booster immunization. Blood, feces, and vaginal washes were collected weekly and assayed by ELISA. High titer T1-SP10MN(A)-specific fecal and vaginal secretory IgA responses were observed, and the response appeared to be augmented following dermal booster immunizations. Specific serum IgG was also detected within 1 week of immunization and remained elevated through week 20 in the 2 animals receiving dermal boosts (titers > or = 6400). This study establishes the Peyer's patch as a promising target tissue for DNA vaccination and demonstrates the efficacy of gene gun-mediated delivery of foreign DNA to a mucosal tissue for the induction of an immune response.     

Evaluation of a four- versus six-week length of stay in the Navy''s alcohol treatment program

A high-performance liquid chromatographic-atmospheric pressure chemical ionization mass spectrometric method was developed for the determination of volatile nitrosamines in dry sausages. Tandem mass spectrometry was applied for the detection of N-nitrosopyrrolidine, N-nitrosodiethylamine and N-nitrosopiperidine. N-nitrosomethylamine was detected by using the selected ion monitoring mode. The occurrence of the four different nitrosamines was monitored in 27 dry sausage samples and a correlation was observed between N-nitrosopyrrolidine and biogenic amines. Nitroso compounds are thus not only formed in heated conditions but formation can also occur during ripening of dry sausages by reaction between residual nitrite and amines formed during the fermentation process.     

Large area microchannel plate detector with amorphous silicon pixel array readout for fast neutron radiography

Fast neutron radiography is a non-destructive testing technique with a variety of industrial applications and the capability for element sensitive imaging for contraband and explosives detection.

Commonly used position sensitive detectors for fast neutron radiography are based on charge coupled devices (CCDs) and scintillators. The limited format of CCDs implies that complex optical systems involving lenses and mirrors are required to indirectly image areas that are larger than 8.6 cm×11.05 cm. The use of optics reduces the light collection efficiency of the imaging system, while the efficiency of hydrogen rich scintillators exploiting the proton recoil reaction is limited by the hydrogen concentration and the magnitude of the neutron scattering cross-section.

The light conversion step inevitably involves a tradeoff in scintillator thickness between light yield and spatial resolution.

The development of large area amorphous silicon (a-Si) panel flat panel photodiode arrays and direct neutron-to-charge converters based on microchannel plates, provide an attractive new form of high resolution, large area, fast neutron imaging detector for the non-destructive imaging of large structures. This paper describes some recent results of both Monte Carlo simulations and measurements for such a detector.     

Pharmacokinetics of vecuronium during acute isovolaemic haemodilution

To evaluate the effect of acute isovolaemic haemodilution on the pharmacokinetics of vecuronium, we studied 13 patients undergoing haemodilution during surgery and 13 control patients. General anaesthesia was induced with thiopentone 4-6 mg kg-1 and fentanyl 2-4 micrograms kg-1, and maintained with enflurane and 60% nitrous oxide in oxygen. The haemodilution patients underwent major elective plastic surgery with an anticipated surgical loss of more than 600 ml. Haemodilution was achieved by drainage of venous blood and i.v. infusion of lactated Ringer's solution and 6% dextran, during which the packed cell volume and haemoglobin concentration decreased from 45% to 28.1% and from 14.7 g dl-1 to 9.1 g dl-1, respectively. After administration of a bolus of vecuronium 100 micrograms kg-1, an improved fluorimetric assay was used to measure the plasma concentrations of vecuronium for 5 h. The results showed that the disposition kinetics of vecuronium were best described mathematically by a three-compartment open model in the two groups. The mean volume of the central compartment and volume of distribution at steady state were 42.3 (SD 11.8) ml kg-1 and 168.4 (31.5) ml kg-1, respectively, in control patients, and significantly greater (55.2 (13.4) ml kg-1 and 225.9 (53.3) ml kg-1) in the haemodilution patients (P < 0.05). The elimination half-life was 50.3 (11.5) min in control patients and significantly greater (68.2 (15.1) min) in the haemodilution patients (P < 0.05). The half-lives of fast distribution and distribution, mean residual time, area under the plasma concentration curve and plasma clearance were unchanged in patients who underwent haemodilution compared with the control group.