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The difference in the defect structures produced by different ion masses in a tungsten lattice is investigated using 80 MeV Au7+ ions and 10 MeV B3+ ions. The details of the defects produced by ions in recrystallized tungsten foil samples are studied using transmission electron microscopy. Dislocations of type b = 1/2 and  were observed in the analysis. While highly energetic gold ion produced small clusters of defects with very few dislocation lines, boron has produced large and sparse clusters with numerous dislocation lines. The difference in the defect structures could be due to the difference in separation between primary knock-on atoms produced by gold and boron ions.
In November and December 2012, 6 patients at a hemodialysis clinic were given a diagnosis of new hepatitis C virus (HCV) infection.
To investigate the outbreak to identify risk factors for transmission.
A case patient was defined as a patient who was HCV-antibody negative on clinic admission but subsequently was found to be HCV-antibody positive from January 1, 2008, through April 30, 2013. Patient charts were reviewed to identify and describe case patients. The hypervariable region 1 of HCV from infected patients was tested to assess viral genetic relatedness. Infection control practices were evaluated via observations. A forensic chemiluminescent agent was used to identify blood contamination on environmental surfaces after cleaning.
Eighteen case patients were identified at the clinic from January 1, 2008, through April 30, 2013, resulting in an estimated 16.7% attack rate. Analysis of HCV quasispecies identified 4 separate clusters of transmission involving 11 case patients. The case patients and previously infected patients in each cluster were treated in neighboring dialysis stations during the same shift, or at the same dialysis station on 2 consecutive shifts. Lapses in infection control were identified. Visible and invisible blood was identified on multiple surfaces at the clinic.
Epidemiologic and laboratory data confirmed transmission of HCV among numerous patients at the dialysis clinic over 6 years. Infection control breaches were likely responsible. This outbreak highlights the importance of rigorous adherence to recommended infection control practices in dialysis settings.
Infect. Control Hosp. Epidemiol. 2016;37(2):125–133
This book provides an overview of the research related to psychological assessment across South Africa. The thirty-six chapters provide a combination of psychometric theory and practical assessment applications in order to combine the currently disparate research that has been conducted locally in this field. Existing South African texts on psychological assessment are predominantly academic textbooks that explain psychometric theory and provide brief descriptions of a few testing instruments. Psychological Assessment in South Africa provides in-depth coverage of a range of areas within the broad field of psychological assessment, including research conducted with various psychological instruments. The chapters critically interrogate the current Eurocentric and Western cultural hegemonic practices that dominate the field of psychological assessment. The book therefore has the potential to function both as an academic text for graduate students, as well as a specialist resource for professionals, including psychologists, psychometrists, remedial teachers and human resource practitioners.
This chapter discusses the fundamental thermodynamic concepts such as laminar flow and turbulent flow. Flow tends to be turbulent in upper airway obstruction, so gas density is influential. The functional anatomy of the upper airway can be reduced to a consideration of a collapsible segment (the pharynx) between two rigid segments (the nasopharynx and the trachea). This system behaves as a Starling resistor and airflow can become limited or completely abolished during spontaneous (negative intrathoracic pressure) breathing. Maintenance of pharyngeal airway patency is a complex neuromuscular phenomenon. In airway obstruction at the pharyngeal level, inspiratory flow may not be increased by increased inspiratory effort, but can be increased by positive pressure applied above the obstruction. The chapter describes the physics and function of a device which permitted ventilation of patients during bronchoscopy. There are a number of misconceptions regarding the operating principles of the Sanders injector.
An increase in the sensitivity of airway reflexes during induction of anaesthesia increases the likelihood of laryngeal spasm and coughing. Some early work identified two types of receptor in the larynx: one a slowly adapting receptor and the second a rapidly adapting receptor thought to be especially sensitive to chemical stimulants. Anaesthetic agents may sensitise the receptors, explaining why some inhaled and intravenous agents may easily precipitate laryngeal spasm. Prior to the administration of lidocaine airway irritation caused not only the cough reflex, but also other respiratory reflexes such as expiration, apnoea and spasmodic panting. It should be noted that the initial application of local anaesthetic agents to the airway may be associated with laryngospasm. It is now thought that the pharyngeal dilators, in addition to the diaphragm, comprise the efferent output of the respiratory centre. Tonic contraction is required to keep the tongue forward and maintain airway patency.
An extubation plan should always be formulated. Extubation in a deep plane of anaesthesia is an advanced technique. One-third of aspiration events occur after extubation. Every extubation technique should ensure minimal interruption in the delivery of oxygen to the patient's lungs, and should extubation fail, ventilation should be achievable with the minimal difficulty or delay. The choice of extubation position reflects a balance between the risks of vomiting post-extubation, and subsequent inhalation and soiling of the lungs, and potential respiratory embarrassment and ease of assisting ventilation. The depth of anaesthesia at the time of extubation is highly important because of the risk of life-threatening laryngospasm. Peri-extubation insertion of a laryngeal mask airway (LMA) is a useful technique for airway maintenance in the recovery period with less airway obstruction and coughing, and higher saturations than either deep or awake extubation. An airway exchange catheter (AEC) is a useful aid.
Guanfacine is a noradrenergic agonist that is believed to improve symptoms of attention-deficit/hyperactivity disorder (ADHD) through selective actions at α2A-adrenoceptors in the prefrontal cortex. A recent double-blind, multicenter trial supports the efficacy and safety of guanfacine extended release (GXR) for pediatric ADHD. This long-term, open-label extension was conducted to study the safety profile and effectiveness of GXR for up to 2 years.
Subjects were 240 children 6–17 years of age with a diagnosis of ADHD who participated in the preceding randomized trial. GXR was initiated at 2 mg/day and titrated as needed in 1-mg increments to a maximum of 4 mg/day to achieve optimal clinical response.
The most common adverse events were somnolence (30.4%), headache (26.3%), fatigue (14.2%), and sedation (13.3%). Somnolence, sedation, and fatigue were usually transient. Cardiovascular-related adverse events were uncommon, although small reductions in mean blood pressure and pulse rate were evident at monthly visits. ADHD Rating Scale, Version IV, total and subscale scores improved significantly from baseline to endpoint for all dose groups (P<.001 for all comparisons, intent-to-treat population).
Long-term treatment with GXR was generally safe for up to 24 months of treatment, and effectiveness was maintained over this treatment period.