Virus Size Analysis by Gas-Phase Mobility Measurements: Resolution Limits.

Electrospraying (ES) dissolved viral particles, followed by charge reduction and size analysis with a differential mobility analyzer (DMA), offers a flexible size-analysis tool for small particles in solution. The technique relies on pioneering work by Kaufman and colleagues, commercialized by TSI, and often referred to as GEMMA. However, viral studies with TSI's GEMMA have suffered from limited resolving power, possibly because of imperfections in either the instrument (DMA or charge reduction) or the sample solution preparation. Here, we explore the limits of the resolution achievable by GEMMA, taking advantage of (i) cleaner charge reduction methods and (ii) DMAs of higher resolving power. Analysis of the literature provides indications that mobility peak widths (fwhm) of 2% or less may be achieved by combining careful sample preparation with improved instrumentation. Working with purified PP7 bacteriophage particles small enough to be classifiable by existing high-resolution DMAs, we confirm that fairly narrow viral mobility peaks may be obtained (relative full width at half-maximum fwhm <5%). Comparison of spectra of a given apian virus sample obtained with TSI's GEMMA and our improved instrumentation confirms that one critical limitation is the DMA. This is further verified by narrow peaks from murine parvovirus, norovirus, and encephalomyelitis virus samples, obtained in our improved GEMMA with little sample preparation, directly from infected cell cultures. Classification of purified large (60 nm) coliphage PR772 particles leads to broad peaks, due to both viral degradation and limited intrinsic resolution of the DMAs used to cover the range of such large particles. We conclude that improved DMAs suitable for high-resolution analysis of particles larger than 30 nm need to be developed to determine the intrinsic mobility width of viral particles.

Building professional competence in dental hygiene students through a community-based practicum.

OBJECTIVES: As Canadians age, there is an increased need for oral health professionals specializing in services for this unique population. Dental hygiene students require exposure to this population to develop professional competencies. This study investigated the dimensions of professional competence that were developed through a practicum for dental hygiene students in long-term care settings while working with older adults. METHODS: Nine dental hygiene students were recruited across two cohorts. All students completed reflective journals describing their practicum experiences. Five students also participated in an audio-recorded focus group and completed a pre-focus group questionnaire. Additionally, the practicum course coordinator completed an audio-recorded interview. Transcripts and journals were coded using a constant comparative approach and themes were identified. RESULTS: Students described developing client-focused skills, such as effective verbal and non-verbal communication with older adults with dementia. Context-based learning was also a large part of the competency development for the practicum students. Understanding the care environment within which these residents lived helped students to understand and empathize why oral health may not be prioritized. Students also developed an understanding of the work of other health professionals in the settings and improved their abilities to communicate with other healthcare providers. However, students recognized that the utility of those interprofessional skills in private practice may be limited. CONCLUSION: Dental hygiene students developed personal and ethical competencies during practicum that are highly transferrable across professional settings. Exposure of students to older adult populations in long-term care may increase the likelihood of dental hygienists working in this area.

Independent older adults perspectives on oral health.

OBJECTIVES: The purpose of this study was to explore oral health experiences from the perspective of older adults' living in community dwellings. The two objectives of this study were to identify facilitators and barriers to oral health care, and to determine how utilization of oral health services compares to utilization of other healthcare services. METHODOLOGY: An interpretive descriptive methodology was employed with a purposive sample of 12 adults, aged 70 years or older. The inclusion criterion was English-speaking seniors residing in community dwellings. Community dwellings were defined as any housing outside of long-term care or other supportive living facilities. Semi-structured interviews were 30-80 min, audio-recorded and transcribed verbatim. Three researchers participated in the comparative analysis process to develop codes, generate categories, interpret patterns and construct themes. RESULTS: Three central themes surfacing from the data were as follows: life course influences on oral health, transparency in delivery of oral health services and interrelationships between oral health and overall health. CONCLUSIONS: Older adults in this study emphasized the value of establishing collaborative and trusting relationships between oral health practitioners and older adults. Oral health practitioners should be clear and transparent when communicating information about oral health costs and be cognizant of different circumstances from childhood to older adulthood that inhibit or promote routine utilization of oral health services. Including oral health services as part of interdisciplinary care teams could help promote understandings of the reciprocal relationship between oral health and general health and improve oral health status for older adults.

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility.

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the National Ignition Facility's diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built-in calorimeters give in situ measurements of the x-ray environment along the sample lines of sight. The measured accuracy of sample responses as well as planned modifications to the XTRRA cassette is discussed.

Torque-mixing magnetic resonance spectroscopy.

A universal, torque-mixing method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by magnetic induction, the transverse component of a precessing dipole moment can be measured in sensitive broadband spectroscopy, here using a resonant mechanical torque sensor. Unlike induction, the torque amplitude allows equilibrium magnetic properties to be monitored simultaneously with the spin dynamics. Comprehensive electron spin resonance spectra of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature reveal assisted switching between magnetization states and mode-dependent spin resonance interactions with nanoscale surface imperfections. The rich detail allows analysis of even complex three-dimensional spin textures. The flexibility of microelectromechanical and optomechanical devices combined with broad generality and capabilities of torque-mixing magnetic resonance spectroscopy offers great opportunities for development of integrated devices.

Expert Consensus on the Management of Adverse Events from EGFR Tyrosine Kinase Inhibitors in the UK.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) such as gefitinib, erlotinib, and afatinib are standard-of-care for first-line treatment of EGFR-mutant advanced non-small cell lung cancer (NSCLC). These drugs have a proven benefit in terms of higher response rate, delaying progression and improvement of quality of life over palliative platinum-based chemotherapy. The most common adverse events (AEs) are gastrointestinal (GI) (diarrhoea and stomatitis/mucositis) and cutaneous (rash, dry skin and paronychia). These are usually mild, but if they become moderate or severe, they can have a negative impact on the patient's quality of life (QOL) and lead to dose modifications or drug discontinuation. Appropriate management of AEs, including prophylactic measures, supportive medications, treatment delays and dose reductions, is essential. A consensus meeting of a UK-based multidisciplinary panel composed of medical and clinical oncologists with a special interest in lung cancer, dermatologists, gastroenterologists, lung cancer nurse specialists and oncology pharmacists was held to develop guidelines on prevention and management of cutaneous (rash, dry skin and paronychia) and GI (diarrhoea, stomatitis and mucositis) AEs associated with the administration of EGFR-TKIs. These guidelines detail supportive measures, treatment delays and dose reductions for EGFR-TKIs. Although the focus of the guidelines is to support healthcare professionals in UK clinical practice, it is anticipated that the management strategies proposed will also be applicable in non-UK settings.

Assessment of Grenadian coastal recreational water quality

OBJECTIVE: To investigate the quality of recreational water along the southern coast of Grenada. DESIGN AND METHODS: A total of 12 sites were sampled along the southern coast. Water samples were collected bi-weekly for four weeks, during the month of November. Samples were taken from six sites per day, two samples per site, amounting to 24 samples per week, totaling 96 samples for four weeks. The samples were collected between the hours of 8am-12pm. Rainfall data for the sampling period was also collected. Variables measured were Enterococci, total coliform, pH, turbidity, nitrate, and phosphate. RESULTS: The site with the highest percentage of sampling days exceeding recommended limits was Beausejour Bay. Sixty percent of sampling days on the Carenage showed a high rate total coliform readings exceeding 200.5 CFU/100 ml. Flamingo Bay (10%) showed the lowest percentage of sampling days that exceeded the recommended limit for Enterococci. Overall, 30.2% of samples from all sites showed Enterococci level above the recommended limits set by Caribbean Environmental Health Institute (35 CFU/100ml). Temperature, turbidity, pH and rainfall variables were inconsistently associated with microbial content. CONCLUSION: Recreational water on the majority of the beaches along the southern end of Grenada for the month of November 2008 exceeded the recommended limits of total coliform and Enterococci. No positive correlation between rainfall and Enterococci was found.

A geophysical shock and air blast simulator at the National Ignition Facility.

The energy partitioning energy coupling experiments at the National Ignition Facility (NIF) have been designed to measure simultaneously the coupling of energy from a laser-driven target into both ground shock and air blast overpressure to nearby media. The source target for the experiment is positioned at a known height above the ground-surface simulant and is heated by four beams from the NIF. The resulting target energy density and specific energy are equal to those of a low-yield nuclear device. The ground-shock stress waves and atmospheric overpressure waveforms that result in our test system are hydrodynamically scaled analogs of full-scale seismic and air blast phenomena. This report summarizes the development of the platform, the simulations, and calculations that underpin the physics measurements that are being made, and finally the data that were measured. Agreement between the data and simulation of the order of a factor of two to three is seen for air blast quantities such as peak overpressure. Historical underground test data for seismic phenomena measured sensor displacements; we measure the stresses generated in our ground-surrogate medium. We find factors-of-a-few agreement between our measured peak stresses and predictions with modern geophysical computer codes.

Emergency medicine resident well-being: stress and satisfaction.

BACKGROUND: Emergency medicine (EM) residents are exposed to many work-related stressors, which affect them both physically and emotionally. It is unknown, however, how EM residents perceive the effect of these stressors on their well-being and how often they use unhealthy coping mechanisms to manage stress. AIMS: To evaluate EM residents' perceptions of stressors related to their overall well-being and the prevalence of various coping mechanisms. METHODS: An online survey instrument was developed to gauge resident stress, satisfaction with current lifestyle, stress coping mechanisms and demographics. A stratified random sample of EM residents from three postgraduate years (PGY-I, PGY-II and PGY-III) was obtained. Descriptive statistics and one-way analysis of variance were used to compare residents across PGY level. RESULTS: There were 120 potential participants in each of the three PGYs. The overall response rate was 30% (109) with mean age of 30 and 61% were male. On a 0-4 scale (0 = completely dissatisfied), respondents in PGY-I reported significantly less satisfaction with lifestyle than those in PGY-II and III (mean rating: 1.29, 1.66 and 1.70, respectively; P < 0.001). There were no significant differences in mean ratings between PGYs on each of the other stress categories: work relationships (1.37), work environment (1.10) and response to patients (1.08). Residents reported exercise (94%), hobbies (89%) and use of alcohol (71%) as coping methods. CONCLUSIONS: Residents reported low satisfaction with current lifestyle. This dissatisfaction was unrelated to perceived work-related stress. Some undesirable coping methods were prevalent, suggesting that training programs could focus on promotion of healthy group activities.

Methodological quality and descriptive characteristics of prosthodontic-related systematic reviews.

Ideally, healthcare systematic reviews (SRs) should be beneficial to practicing professionals in making evidence-based clinical decisions. However, the conclusions drawn from SRs are directly related to the quality of the SR and of the included studies. The aim was to investigate the methodological quality and key descriptive characteristics of SRs published in prosthodontics. Methodological quality was analysed using the Assessment of Multiple Reviews (AMSTAR) tool. Several electronic resources (MEDLINE, EMBASE, Web of Science and American Dental Association's Evidence-based Dentistry website) were searched. In total 106 SRs were located. Key descriptive characteristics and methodological quality features were gathered and assessed, and descriptive and inferential statistical testing performed. Most SRs in this sample originated from the European continent followed by North America. Two to five authors conducted most SRs; the majority was affiliated with academic institutions and had prior experience publishing SRs. The majority of SRs were published in specialty dentistry journals, with implant or implant-related topics, the primary topics of interest for most. According to AMSTAR, most quality aspects were adequately fulfilled by less than half of the reviews. Publication bias and grey literature searches were the most poorly adhered components. Overall, the methodological quality of the prosthodontic-related systematic was deemed limited. Future recommendations would include authors to have prior training in conducting SRs and for journals to include a universal checklist that should be adhered to address all key characteristics of an unbiased SR process.

Candidatus Mycoplasma haematoparvum and Mycoplasma haemocanis infections in dogs from the United States.

Mycoplasma haemocanis (Mhc) and Candidatus Mycoplasma haematoparvum (CMhp) have been described in dogs. Historically, microscopic visualization of hemotropic Mycoplasma spp. has occurred most often in immunocompromised or splenectomized dogs. The aim of this study was to determine the Mhc and CMhp prevalences among dogs from the United States. Novel 16S rRNA and RNAseP gene PCR assays were used to amplify hemotropic Mycoplasma species DNA for GenBank sequence alignment. Among the study population, hemoplasma prevalence was 1.3% (7 out of 506), with Mhc and CMhp prevalences of 0.6% and 0.8%, respectively. Two of six CMhp-infected dogs were co-infected with a Bartonella sp., and a third dog was seroreactive to Bartonella henselae antigens. The prevalence of Mhc and CMhp in this study was low; potential blood donors should be screened; and dogs and people can be co-infected with hemoplasma and Bartonella spp.

Arrhythmia discrimination using hemoglobin spectroscopy in humans.

BACKGROUND: Inappropriate therapies are frequently delivered by implantable cardioverter-defibrillators (ICDs). We have investigated muscle perfusion as a means of augmenting arrhythmia discrimination by using implanted near-infrared spectroscopy. OBJECTIVE: To evaluate hemodynamic stability by monitoring muscle perfusion from within the ICD pocket, in fresh tissue and inside the scar capsule on preexisting ICD generators, during induced cardiac arrhythmias, in humans. METHODS: The sensor was implanted on or under the pectoral muscle, during ICD defibrillation threshold testing. A microvascular oxygenation trend indicator (O2 Index) was computed during 74 induced ventricular fibrillation and 34 normal sinus rhythm episodes in 34 patients and also during 28 atrial and 90 ventricular overdrive pacing episodes as simulations of supraventricular and ventricular tachycardias, respectively. RESULTS: On average, the change in oxygenation, based on the O2 Index, was statistically significant (P <.003) from baseline within 3 seconds following cardiac arrest. An optimized O2 Index, used for detecting the hemodynamic trend, exhibited a decreasing trend during ventricular fibrillation (P <.0001) and was different from that during normal sinus rhythm (P <.0001). The sensitivity for the detection of ventricular fibrillation was 100%, and the specificity for the rejection of normal sinus rhythm was 82% in the presence of scar tissue on the optical sensor. For a 35-mm Hg drop in the mean arterial pressure as the threshold for hemodynamic instability, the specificity for the rejection of hemodynamically stable atrial and ventricular pacing episodes was 93% and 71%, respectively. CONCLUSION: An implantable near-infrared spectroscopic sensor may be useful for hemodynamic monitoring during cardiac arrhythmias to prevent inappropriate therapy.

A multicentre study of capecitabine, oxaliplatin plus bevacizumab as perioperative treatment of patients with poor-risk colorectal liver-only metastases not selected for upfront resection.

BACKGROUND: Perioperative chemotherapy improves outcome in resectable colorectal liver-only metastasis (CLM). This study aimed to evaluate perioperative CAPOX (capecitabine-oxaliplatin) plus bevacizumab in patients with poor-risk CLM not selected for upfront resection. PATIENTS AND METHODS: Poor-risk CLM was defined as follows: more than four metastases, diameter >5 cm, R0 resection unlikely, inadequate viable liver function if undergoing upfront resection, inability to retain liver vascular supply, or synchronous colorectal primary presentation. Patients underwent baseline computed tomography, magnetic resonance imaging, and/or positron emission tomography (PET) for staging and received neoadjuvant CAPOX plus bevacizumab, with resectability assessed every four cycles. Primary end point was radiological objective response rate (ORR). RESULTS: Forty-six patients were recruited, of which 91% underwent PET to ensure metastases confined to liver. Following neoadjuvant CAPOX plus bevacizumab, the ORR was 78% (95% confidence interval 63% to 89%). This allowed 12 of 30 (40%) patients with initial nonsynchronous unresectable CLM to be converted to resectability. In addition, 10 of 15 (67%) patients with synchronous resectable CLM underwent liver resection, with four additional patients being observed alone due to excellent response to neoadjuvant therapy. No grade 3-4 perioperative complications were seen. CONCLUSION: Neoadjuvant CAPOX plus bevacizumab resulted in a high response rate for patients with CLMs with poor-risk features not selected for upfront resection and converted 40% of patients to resectability.

WAG-F8(m1Ycb) rats harboring a factor VIII gene mutation provide a new animal model for hemophilia A.

BACKGROUND: We recently described an inherited coagulopathy arising in an inbred colony of WAG/RijYcb rats. The bleeding phenotype, demonstrated by both male and female rats, included periarticular hemorrhage, spontaneous bruising, prolonged bleeding from minor wounds and maternal peripartum deaths. Coagulation testing of affected rats revealed normal prothrombin time but prolongation of activated partial thromboplastin time to twice that of controls. OBJECTIVE: To determine the specific coagulation factor and the underlying genetic defect responsible for the inherited coagulopathy in the WAG/RijYcb rats. RESULTS: Evaluation of individual clotting factor activities revealed that the affected animals had a specific deficiency of factor (F) VIII (FVIII). The FVIII gene (F8) has an autosomal location on chromosome 18 in rats, in contrast to its location on the X chromosome in mice and humans. Sequencing of F8 cDNA led to the identification of a point mutation resulting in a substitution, Leu176Pro, in the A1 domain, that is predicted to disrupt the tertiary structure of the FVIII molecule. Administration of human plasma or human recombinant FVIII corrects the coagulation abnormality in the affected animals. CONCLUSIONS: We have now identified the genetic basis of the hemostatic defect in the WAG/RijYcb rat colony. The larger size of rats relative to mice and the presence of this coagulation defect in both sexes provide a unique model, well-suited to the development of novel therapies for acquired and hereditary FVIII deficiencies.

An argument for dental hygiene to develop as a discipline.

UNLABELLED: The practice of dental hygiene was developed to provide oral health education and preventive oral health care, originally for children. It has grown to provide oral health services valued by a broad spectrum of society, but has not attained the desired respect and status accorded to other professional groups. OBJECTIVE: Professional disciplines link actions of practitioners with the science that is the foundation of practice. The purpose of this paper is to examine whether dental hygiene practice could benefit from pursuit of development as a discipline. METHODS: Literature on professionalization and disciplines, related to dental hygiene in general and the North American context specifically, was retrieved from databases and grey sources, such as organizational reports. Dental hygiene's current characteristics relative to a discipline were examined. RESULTS: Dental hygiene has developed some characteristics of a discipline, such as identifying a metaparadigm that includes concepts of the client, the environment, health/oral health and dental hygiene actions, with a perspective that includes a focus on disease prevention and oral health promotion. However, research production by dental hygienists has been limited, and often not situated within theoretical or conceptual frameworks. CONCLUSION: Dental hygiene draws its knowledge for practice from a variety of sources. Dental hygiene could strengthen its value to society by prioritizing development of highly skilled researchers to study interventions leading to improved oral outcomes, and transferring that knowledge to practitioners, strengthening links between practice and science. Intentional pursuit of knowledge for practice would lead to dental hygiene's eventual emergence as a professional discipline.

Persistent Seoul virus infection in Lewis rats.

Mechanistic studies of hantavirus persistence in rodent reservoirs have been limited by the lack of a versatile animal model. This report describes findings from experimental infection of inbred Lewis rats with Seoul virus strain 80-39. Rats inoculated with virus intraperitoneally at 6 days of age became persistently infected without clinical signs. Tissues from Seoul virus-inoculated 6-day-old rats were assessed at 6, 9, and 12 weeks post-inoculation for viral RNA by RT-PCR and in situ hybridization (ISH) and for infectious virus by inoculation of Vero E6 cells. Virus was isolated from lung and kidney of infected rats at 6 weeks and viral RNA was detected in lung, kidney, pancreas, salivary gland, brain, spleen, liver and skin at 6, 9 and 12 weeks. Rats inoculated with Seoul virus intraperitoneally at 10 or 21 days of age became infected without clinical signs but had low to undetectable levels of viral RNA in tissues at 6 weeks post-inoculation. ISH identified vascular smooth muscle and endothelial cells as common sites of persistent infection. Cultured rat smooth muscle cells and to a lesser extent cultured endothelial cells also were susceptible to Seoul virus infection. Pancreatic infection resulted in insulitis with associated hyperglycemia. These studies demonstrate that infant Lewis rats are uniformly susceptible to asymptomatic persistent Seoul virus infection. Additionally, they offer opportunities for correlative in vivo and in vitro study of Seoul virus interactions in host cell types that support persistent infection.

Foundress re-emergence and fig permeability in fig tree-wasp mutualisms.

Some female pollinating fig wasps (foundresses) re-emerge from figs after oviposition/pollination. We investigated why this occurs in the mutualism between the gynodioecious Ficus montana and Liporrhopalum tentacularis. Re-emergence increased with foundress density in figs and some foundresses oviposited in two male figs, indicating that they re-emerge because of oviposition site limitation. Re-emergence was independent of fig diameter, indicating that permeability is not because of fig age at entry. Rather, as some foundresses also pollinate two female figs we suggest permeability is selected for because it increases pollinator production and/or efficiency (although, potentially opposing these hypotheses, we also found between-tree differences in permeability in male figs). In addition, we show that re-emergence is much more common than previously suspected, and more common from gynodioecious than monoecious fig species. We argue that our findings in F. montana could explain this pattern of incidence.

A retrospective study of the behavioural and psychological symptoms of mid and late phase Alzheimer's disease.

AIM: To document the behavioural and psychological symptoms in patients with a diagnosis of established Alzheimer's disease (AD) for at least 3 years. METHODS: Patients with a > or =3 year history of AD (NINCDS/ADRDA) were recruited from old age psychiatrist and elderly care memory clinics. Information regarding duration of symptoms and non-cognitive symptomatology was obtained during interview with a carer or next-of-kin who had contact with the patient at least 3 times a week and for at least 3 years. MMSE, FAST and NPI including caregiver distress, were used to assess cognition, function and behavioural/psychological disturbance respectively. With each non-cognitive symptom the carer was asked to estimate its onset. RESULTS: The mean age of patients was 77 years and duration of illness 87 months. Mean MMSE was 8/30 and FAST score 6d. Of the psychological symptoms occurring at any stage, depression (56%), delusions (55%) and anxiety (52%) were most common, with hallucinations, elation and disinhibition occurring less frequently. In general, behavioural changes were more common with apathy occurring in 88% of patients, motor behaviour in 70%, aggression in 66%, irritability and appetite changes in 60% and sleep disturbance in 54%. All symptoms except apathy became less common when the carer was asked if they were still present in the last month. Mean onset of psychological symptoms was 47 months. Mean onset of behavioural symptoms was 48 months. Behavioural disturbance seemed to cause more care-giver distress than psychological change. CONCLUSION: The results show behavioural and psychological symptoms in AD are common and distressing for carers. They appear to require a consistent period of neurodegeneration in order to emerge.

Cardiac arrest in private locations: different strategies are needed to improve outcome.

BACKGROUND: A tremendous amount of public resources are focused on improving cardiac arrest (OHCA) survival in public places, yet most OHCAs occur in private residences. METHODS AND RESULTS: A prospective, observational study of patients transported to seven urban and suburban hospitals and the individuals who called 911 at the time of a cardiac arrest (bystander) was performed. Bystanders (N=543) were interviewed via telephone beginning 2 weeks after the incident to obtain data regarding patient and bystander demographics, including cardiopulmonary resuscitation (CPR) training. Of all arrests 80.2% were in homes. Patients who arrested in public places were significantly younger (63.2 vs. 67.2, P<0.02), more often had an initial rhythm of VF (63.0 vs. 37.7%, P<0.001), were seen or heard to have collapsed by a bystander (74.8 vs. 48.1%, P<0.001), received bystander CPR (60.2 vs. 28.6%, P<0.001), and survived to DC (17.5 vs. 5.5%, P<0.001). Patients who arrested at home were older and had an older bystander (55.4 vs. 41.3, P<0.001). The bystander was less likely to be CPR trained (65.0 vs. 47.4%, P<0.001), less likely to be trained within the last 5 years (49.2 vs. 17.9, P<0.001), and less likely to perform CPR if trained (64.2 vs. 30.0%, P<0.001). Collapse to shock intervals for public versus home VF patients were not different. CONCLUSIONS: Many important characteristics of cardiac arrest patients and the bystander differ in public versus private locations. Fundamentally different strategies are needed to improve survival from these events.