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The effort to develop metallic alloys with increased structural strength and improved radiation performance has focused on the incorporation of either solute elements or microstructural inhomogeneities to mitigate damage. The recent discovery and development of single-phase concentrated solid-solution alloys (SP-CSAs) has prompted fundamental questions that challenge established theories and models currently applicable to conventional alloys. The current understanding of electronic and atomic effects, defect evolution, and microstructure progression suggests that radiation energy dissipates in SP-CSAs at different interaction strengths via energy carriers (electrons, phonons, and magnons). Modification of electronic- and atomic-level heterogeneities and tailoring of atomic transport processes can be realized through tuning of the chemical complexity of SP-CSAs by the selection of appropriate elements and their concentrations. Fundamental understanding of controlling energy dissipation via site-to-site chemical complexity reveals new design principles for predictive discovery and guided synthesis of new alloys with targeted functionalities, including radiation tolerance.
Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic disease transmitted from dromedary camels to people, which can result in outbreaks with human-to-human transmission. Because it is a subclinical infection in camels, epidemiological measures other than prevalence are challenging to assess. This study estimated the force of infection (FOI) of MERS-CoV in camel populations from age-stratified serological data. A cross-sectional study of MERS-CoV was conducted in Kenya from July 2016 to July 2017. Seroprevalence was stratified into four age groups: <1, 1–2, 2–3 and >3 years old. Age-independent and age-dependent linear and quadratic generalised linear models were used to estimate FOI in pastoral and ranching camel herds. Models were compared based on computed AIC values. Among pastoral herds, the age-dependent quadratic FOI was the best fit model, while the age-independent FOI was the best fit for the ranching herd data. FOI provides an indirect estimate of infection risk, which is especially valuable where direct estimates of incidence and other measures of infection are challenging to obtain. The FOIs estimated in this study provide important insight about MERS-CoV dynamics in the reservoir species, and contribute to our understanding of the zoonotic risks of this important public health threat.
Norovirus is a predominant cause of infectious gastroenteritis in countries worldwide [1–5]. It accounts for approximately 50% of acute gastroenteritis (AGE) and >90% of viral gastroenteritis outbreaks [6, 7]. The incubation period ranges between 10 and 48 h and illness duration is generally 1–3 days with self-limiting symptoms; however, this duration is often longer (e.g. 4–6 days) in vulnerable populations such as hospital patients or young children [2, 8]. Symptomatic infection of norovirus presents as acute vomiting, diarrhoea, abdominal cramps and nausea, with severe vomiting and diarrhoea (non-bloody) being most common [2, 5, 9].
To assess antimicrobial utilization before and after a change in urine culture ordering practice in adult intensive care units (ICUs) whereby urine cultures were only performed when pyuria was detected.
A 700-bed academic medical center
Patients admitted to any adult ICU
Aggregate data for all adult ICUs were obtained for population-level antimicrobial use (days of therapy [DOT]), urine cultures performed, and bacteriuria, all measured per 1,000 patient days before the intervention (January–December 2012) and after the intervention (January–December 2013). These data were compared using interrupted time series negative binomial regression. Randomly selected patient charts from the population of adult ICU patients with orders for urine culture in the presence of indwelling or recently removed urinary catheters were reviewed for demographic, clinical, and antimicrobial use characteristics, and pre- and post-intervention data were compared.
Statistically significant reductions were observed in aggregate monthly rates of urine cultures performed and bacteriuria detected but not in DOT. At the patient level, compared with the pre-intervention group (n=250), in the post-intervention group (n=250), fewer patients started a new antimicrobial therapy based on urine culture results (23% vs 41%, P=.002), but no difference in the mean total DOT was observed.
A change in urine-culture ordering practice was associated with a decrease in the percentage of patients starting a new antimicrobial therapy based on the index urine-culture order but not in total duration of antimicrobial use in adult ICUs. Other drivers of antimicrobial use in ICU patients need to be evaluated by antimicrobial stewardship teams.
Infect. Control Hosp. Epidemiol. 2016;37(4):448–454
Evaluate the effect of outpatient antimicrobial stewardship programs on prescribing, patient, microbial outcomes, and costs.
Search of MEDLINE (2000 through November 2013), Cochrane Library, and reference lists of relevant studies. We included English language studies with patient populations relevant to the United States (eg, infectious conditions, prescription services) evaluating stewardship programs in outpatient settings and reporting outcomes of interest. Data regarding study characteristics and outcomes were extracted and organized by intervention type.
We identified 50 studies eligible for inclusion, with most (29 of 50; 58%) reporting on respiratory tract infections, followed by multiple/unspecified infections (17 of 50; 34%). We found medium-strength evidence that stewardship programs incorporating communication skills training and laboratory testing are associated with reductions in antimicrobial use, and low-strength evidence that other stewardship interventions are associated with improved prescribing. Patient-centered outcomes, which were infrequently reported, were not adversely affected. Medication costs were generally lower with stewardship interventions, but overall program costs were rarely reported. No studies reported microbial outcomes, and data regarding outpatient settings other than primary care clinics are limited.
Low- to moderate-strength evidence suggests that antimicrobial stewardship programs in outpatient settings improve antimicrobial prescribing without adversely effecting patient outcomes. Effectiveness depends on program type. Most studies were not designed to measure patient or resistance outcomes. Data regarding sustainability and scalability of interventions are limited.
Evaluate the evidence for effects of inpatient antimicrobial stewardship programs (ASPs) on patient, prescribing, and microbial outcomes.
Search of MEDLINE (2000 through November 2013), Cochrane Library, and reference lists of relevant studies. We included English language studies with patient populations relevant to the United States (ie, infectious conditions and prescriptions required for antimicrobials) that evaluated ASP interventions and reported outcomes of interest. Study characteristics and outcomes data were extracted and reviewed by investigators and trained research personnel.
Few intervention types (eg, audit and feedback, guideline implementation, and decision support) substantially impacted patient outcomes, including mortality, length of stay, readmission, or incidence of Clostridium difficile infection. However, most interventions were not powered adequately to demonstrate impacts on patient outcomes. Most interventions were associated with improved prescribing patterns as measured by decreased antimicrobial use or increased appropriate use. Where reported, ASPs were generally associated with improvements in microbial outcomes, including institutional resistance patterns or resistance in the study population. Few data were provided on harms, sustainability, or key intervention components. Studies were typically of short duration, low in methodological quality, and varied in study design, populations enrolled, hospital setting, ASP intent, intervention composition and implementation, comparison group, and outcomes assessed.
Numerous studies suggest that ASPs can improve prescribing and microbial outcomes. Strength of evidence was low, and most studies were not designed adequately to detect improvements in mortality or other patient outcomes, but obvious adverse effects on patient outcomes were not reported.
The association between mothers' psychological control and their children's emotional adjustment problems is well documented. However, processes that may explain this association are not well understood. The present study tested the idea that relational aggression and psychological control within the context of the sibling relationship may help to account for the relation between mothers' psychological control and adolescents' internalizing symptoms. Older (M = 16.46, SD = 1.35 years) and younger (M = 13.67, SD = 1.56 years) siblings from 101 dyads rated the psychological control they received from mothers and siblings, and the relational aggression they received from siblings. Despite some similarities between psychological control and relational aggression, confirmatory factor analyses provided evidence that the two sibling processes are distinct. Maternal psychological control was related to psychological control and relational aggression within the sibling relationship, which were related to adolescents' anxiety and depressed mood. In addition, sibling relational aggression was a more powerful mediator of the relationship between maternal psychological control and adolescent adjustment than sibling psychological control.
Some data suggest that older adults with anxiety disorders do not respond as well to treatment as do younger adults.
We examined age differences in outcomes from the Coordinated Anxiety Learning and Management (CALM) study, an effectiveness trial comparing usual care to a computer-assisted collaborative care intervention for primary care patients with panic disorder, generalised anxiety disorder, post-traumatic stress disorder (PTSD), and/or social anxiety disorder. This is the first study to examine the efficacy of a collaborative care intervention in a sample that included both younger and older adults with anxiety disorders. We hypothesised that older adults would show a poorer response to the intervention than younger adults.
We examined findings for the overall sample, as well as within each diagnostic category (clinicaltrials.gov identifier: NCT00347269).
The CALM intervention was more effective than usual care among younger adults overall and for those with generalised anxiety disorder, panic disorder and social anxiety disorder. Among older adults, the intervention was effective overall and for those with social anxiety disorder and PTSD but not for those with panic disorder or generalised anxiety disorder. The effects of the intervention also appeared to erode by the 18-month follow-up, and there were no significant effects on remission among the older adults.
These results are consistent with the findings of other investigators suggesting that medications and psychotherapy for anxiety disorders may not be as effective for older individuals as they are for younger people.
We investigate through-thickness hardness and modulus of Zr50Cu45Al5 metallic glass melt-spun ribbon. Because of their thinness, the ribbons are challenging to measure, so we employ a novel nanoindentation based-method to remove artifacts caused by ribbon flexing and edge effects. Hardness and modulus vary approximately linearly across the thickness but, unlike bulk ingots, the side of the ribbon that cooled most quickly had the highest hardness and modulus. This “inverse” variation may be caused by the fast-moving solidification front, which might conceivably, for instance, push free volume in advance of it. Annealing near Tg causes both hardness and modulus to increase and become more uniform across the thickness.
Sleep disturbances are persistent residual symptoms following remission of major depressive disorder (MDD) and are associated with an increased risk of MDD recurrence. The purpose of the current study was to examine the effect of exercise augmentation on self-reported sleep quality in participants with non-remitted MDD.
Participants were randomized to receive selective serotonin reuptake inhibitor (SSRI) augmentation with one of two doses of exercise: 16 kilocalories per kilogram of body weight per week (KKW) or 4 KKW for 12 weeks. Depressive symptoms were assessed using the clinician-rated Inventory of Depressive Symptomatology (IDS-C). The four sleep-related items on the IDS-C (Sleep Onset Insomnia, Mid-Nocturnal Insomnia, Early Morning Insomnia, and Hypersomnia) were used to assess self-reported sleep quality.
Significant decreases in total insomnia (p < 0.0001) were observed, along with decreases in sleep onset, mid-nocturnal and early-morning insomnia (p's <0.002). Hypersomnia did not change significantly (p = 0.38). Changes in total, mid-nocturnal and early-morning insomnia were independent of changes in depressive symptoms. Higher baseline hypersomnia predicted a greater decrease in depression severity following exercise treatment (p = 0.0057). No significant moderating effect of any baseline sleep on change in depression severity was observed. There were no significant differences between exercise treatment groups on total insomnia or any individual sleep item.
Exercise augmentation resulted in improvements in self-reported sleep quality in patients with non-remitted MDD. Given the prevalence of insomnia as a residual symptom following MDD treatment and the associated risk of MDD recurrence, exercise augmentation may have an important role in the treatment of MDD.
Background: Identifying individuals at risk for mental health problems after a disaster often involves assessing potentially traumatic exposures inherent to the disaster. Survivors of disasters also may have been exposed, both before and during the event, to trauma not directly related to the disaster. A substantial literature suggests exposure to interpersonal violence may have more severe negative outcomes than exposure to non-violent events; however, it is unclear whether violent vs nonviolent exposures before and during a disaster have differential effects on postdisaster psychological functioning.
Methods: We examined the associations of violent and nonviolent exposures before and during Hurricane Katrina with postdisaster psychological functioning in a sample of male military veterans.
Results: Violent and nonviolent exposures post-Hurricane Katrina as well as pre-Katrina violent exposures were significantly associated with symptoms of posttraumatic stress disorder, panic, and generalized anxiety disorder more than 2 years after the storm. Moreover, veterans who reported violent exposures pre-Katrina were more than 4 times more likely to have reexperienced interpersonal violence during Katrina than those who did not report such exposures.
Conclusions: Results suggest assessing disaster-specific experiences in addition to predisaster interpersonal violence may be important for identifying and triaging individuals at risk for postdisaster mental health problems.
(Disaster Med Public Health Preparedness. 2011;5:S227-S234)
Organosilicate glasses (OSG), also known as SiCOH or carbon-doped oxide are used as low-k inter-metal dielectrics for integrated circuits. The material must fulfill two conflicting requirements: It has to have low density to reduce the dielectric constant and be mechanically stable enough to withstand mechanical stress during subsequent production steps. Experimental advances in improving their mechanical and electrical properties have not yet been theoretically examined at the ab initio level, due to the relatively large model sizes necessary for amorphous materials. We employ the density-functional based tight-binding (DFTB) method to achieve an accurate description of OSG properties at different compositions. We analyze the influence of composition and topological defects on the density and bulk modulus of non-porous OSG. We find that the dependence of density and stiffness on chemical composition is of different nature. This difference is traced to a transition between different mechanisms of elastic deformation in silica glass and in silicon hydrocarbide, which is also the reason for different sensitivity to topological defects in the two materials.
Carbon nanotubes (CNTs) are appealing materials for biomedical applications due to their unique chemical, electrical and mechanical properties. The emphasis of the present work is on controlling the structure and symmetry of carbon nanotubes by imposing an applied stress at the CNT growth site. CNTs were grown under these conditions using standard chemical vapor deposition (CVD) techniques and were subsequently characterized with a scanning electron microscope; the methodology and implications of this approach are discussed herein.