Comparing the clinical effects of local administration of minocycline ointment and doxycycline solution in the treatment of acute periodontal abscesses: a retrospective clinical study

PURPOSE

The objective of this retrospective clinical study was to provide evidence supporting the adjunctive local application of doxycycline solution or minocycline ointment, in conjunction with drainage, for the treatment of acute periodontal abscesses.

METHODS

The study included 63 patients who had received treatment for acute periodontal abscesses through drainage supplemented with 1 of 3 types of adjunctive medications during their initial visit (visit 1; baseline): 1) saline irrigation (the control group), 2) 2% minocycline ointment (the TM group), or 3) 300 mg/mL doxycycline irrigation (the TD group). The same adjunctive medication was administered at visit 2, which took place 1 week after visit 1. Probing depth (PD), bleeding on probing (BOP), plaque index, gingival recession, clinical attachment level, and tooth mobility were clinically evaluated at visits 1, 2, and a third visit (visit 3; 4 weeks after visit 1). Statistical significance was considered to be indicated by P values <0.05.

RESULTS

By visit 3, all clinical indices and tooth mobility had significantly decreased in each group. At this visit, PD and BOP on the abscess side were significantly lower in the TM and TD groups compared to the control group. The TD group showed a significantly greater improvement than the TM group, with mean PD reductions of 1.09 mm in the control group, 1.88 mm in the TM group, and 2.88 mm in the TD group. Similarly, mean BOP reductions were 45% in the control group, 73.02% in the TM group, and 95.45% in the TD group.

CONCLUSIONS

Local and adjunctive administration of doxycycline and minocycline in combination with drainage exhibited clinical advantages over drainage alone in improving PD and BOP. Notably, a doxycycline solution of 300 mg/mL was more effective than a 2% minocycline ointment.

Punctuated growth of InAs quantum dashes-in-a-well for enhanced 2-μm emission

InAs quantum dashes (Qdash) engineered to emit near 2 μm are envisioned to be promising quantum emitters for next-generation technologies in sensing and communications. In this study, we explore the effect of punctuated growth (PG) on the structure and optical properties of InP-based InAs Qdashes emitting near the 2-μm wavelength. Morphological analysis revealed that PG led to an improvement in in-plane size uniformity and increases in average height and height distribution. A 2 × boost in photoluminescence intensity was observed, which we attribute to improved lateral dimensions and structural stabilization. PG encouraged formation of taller Qdashes while photoluminescence measurements revealed a blue-shift in the peak wavelength. We proposed that the blue-shift originates from the thinner quantum well cap and decreased distance between the Qdash and InAlGaAs barrier. This study on the punctuated growth of large InAs Qdashes is a step toward realizing bright, tunable, and broadband sources for 2-μm communications, spectroscopy, and sensing.

Stabilized Radiation Pressure Acceleration and Neutron Generation in Ultrathin Deuterated Foils

Premature relativistic transparency of ultrathin, laser-irradiated targets is recognized as an obstacle to achieving a stable radiation pressure acceleration in the "light sail" (LS) mode. Experimental data, corroborated by 2D PIC simulations, show that a few-nm thick overcoat surface layer of high Z material significantly improves ion bunching at high energies during the acceleration. This is diagnosed by simultaneous ion and neutron spectroscopy following irradiation of deuterated plastic targets. In particular, copious and directional neutron production (significantly larger than for other in-target schemes) arises, under optimal parameters, as a signature of plasma layer integrity during the acceleration.

Neuroimaging Correlates of Post-Traumatic Stress Disorder in Traumatic Brain Injury: A Systematic Review of the Literature

Introduction

Neuroimaging has been a highly utilized technique for studying traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) independently of one another, however, neuroimaging has increasingly been identified as a useful tool in better understanding TBI-related psychiatric conditions, such as PTSD.

Objectives

To complete a systematic review of the literature examining neuroimaging findings in TBI-related PTSD and to highlight the current literature’s limitations in order to strengthen future research.

Methods

A PRISMA compliant literature search was conducted in PubMed (MEDLINE), PsychINFO, EMBASE, and Scopus databases prior to May of 2019. The initial database query yielded 4388 unique articles, which were narrowed down based on specified inclusion criteria (e.g., clear TBI definition, clinician-diagnosed PTSD, statistically analyzed relationship between neuroimaging and PTSD, quantified time interval between TBI and neuroimaging).

Results

A final cohort of 10 articles met inclusion criteria, comprising the findings of 482 participants with TBI. Key neuroanatomical findings among the included articles suggest that PTSD is associated with significant changes in whole-brain networks of resting state connectivity and disruptions in bilateral frontal and temporal white matter tracts, fronto-limbic pathways, the internal capsule, and the uncinate fasciculus (Figure 1). Figure 1a:

Absolute calibration of Fujifilm BAS-TR image plate response to laser driven protons up to 40 MeV

Image plates (IPs) are a popular detector in the field of laser driven ion acceleration, owing to their high dynamic range and reusability. An absolute calibration of these detectors to laser-driven protons in the routinely produced tens of MeV energy range is, therefore, essential. In this paper, the response of Fujifilm BAS-TR IPs to 1-40 MeV protons is calibrated by employing the detectors in high resolution Thomson parabola spectrometers in conjunction with a CR-39 nuclear track detector to determine absolute proton numbers. While CR-39 was placed in front of the image plate for lower energy protons, it was placed behind the image plate for energies above 10 MeV using suitable metal filters sandwiched between the image plate and CR-39 to select specific energies. The measured response agrees well with previously reported calibrations as well as standard models of IP response, providing, for the first time, an absolute calibration over a large range of proton energies of relevance to current experiments.

Probing sedimentation non-ideality of particulate systems using analytical centrifugation

Analytical centrifugation is a versatile technique for the quantitative characterization of colloidal systems including colloidal stability. The recent developments in data acquisition and evaluation allow the accurate determination of particle size, shape anisotropy and particle density. High precision analytical centrifugation is in particular suited for the study of particle interactions and concentration-dependent sedimentation coefficients. We present a holistic approach for the quantitative determination of sedimentation non-ideality via analytical centrifugation for polydisperse, plain and amino-functionalized silica particles spanning over one order of magnitude in particle size between 100 nm and 1200 nm. These systems typically behave as neutral hard spheres as predicted by auxiliary lattice Boltzmann simulations. The extent of electrostatic interactions and their impact on sedimentation non-ideality can be quantified by the repulsion range, which is the ratio of the Debye length and the average interparticle distance. Experimental access to the repulsion range is provided through conductivity measurements. With the experimental repulsion range at hand, we estimate the effect of polydispersity on concentration-dependent sedimentation properties through a combination of lattice Boltzmann and Brownian dynamics simulations. Finally, we determine the concentration-dependent sedimentation properties of charge-stabilized, fluorescently-labeled silica particles with a nominal particle size of 30 nm and reduced interparticle distance, hence an elevated repulsion range. Overall, our results demonstrate how the influence of hard-sphere type and electrostatic interactions can be quantified when probing sedimentation non-ideality of particulate systems using analytical centrifugation even for systems exhibiting moderate sample heterogeneity and complex interactions.

Predicting patient outcomes in psychiatric hospitals with routine data: a machine learning approach

BACKGROUND

A common problem in machine learning applications is availability of data at the point of decision making. The aim of the present study was to use routine data readily available at admission to predict aspects relevant to the organization of psychiatric hospital care. A further aim was to compare the results of a machine learning approach with those obtained through a traditional method and those obtained through a naive baseline classifier.

METHODS

The study included consecutively discharged patients between 1st of January 2017 and 31st of December 2018 from nine psychiatric hospitals in Hesse, Germany. We compared the predictive performance achieved by stochastic gradient boosting (GBM) with multiple logistic regression and a naive baseline classifier. We tested the performance of our final models on unseen patients from another calendar year and from different hospitals.

RESULTS

The study included 45,388 inpatient episodes. The models' performance, as measured by the area under the Receiver Operating Characteristic curve, varied strongly between the predicted outcomes, with relatively high performance in the prediction of coercive treatment (area under the curve: 0.83) and 1:1 observations (0.80) and relatively poor performance in the prediction of short length of stay (0.69) and non-response to treatment (0.65). The GBM performed slightly better than logistic regression. Both approaches were substantially better than a naive prediction based solely on basic diagnostic grouping.

CONCLUSION

The present study has shown that administrative routine data can be used to predict aspects relevant to the organisation of psychiatric hospital care. Future research should investigate the predictive performance that is necessary to provide effective assistance in clinical practice for the benefit of both staff and patients.

The Impact of Rate Formulations on Stochastic Molecular Motor Dynamics

Cells are complex structures which require considerable amounts of organization via transport of large intracellular cargo. While passive diffusion is often sufficiently fast for the transport of smaller cargo, active transport is necessary to organize large structures on the short timescales necessary for biological function. The main mechanism of this transport is by cargo attachment to motors which walk in a directed fashion along intracellular filaments. There are a number of models which seek to describe the motion of motors with attached cargo, from detailed microscopic to coarse phenomenological descriptions. We focus on the intermediate-detailed discrete stochastic hopping models, and explore how cargo transport changes depending on the number of motors, motor interaction, system constraints and rate formulations, which are derived from common thermodynamic assumptions. We find that, despite obeying the same detailed balance constraint, the choice of rate formulation considerably affects the characteristics of the overall motion of the system, with one rate formulation exhibiting novel behavior of loaded motor groups moving faster than a single unloaded motor.

PSIX-37 Evaluation of reducing dietary crude protein concentrations coupled with increasing essential amino acids on growth performance in fattening pigs

A body of evidence suggests that low-protein diets in swine have benefits in view of environmental stewardship and economic returns. The present study was performed to evaluate essential amino acid (EAA) supplementation in the diets with reducing crude protein (CP) concentrations on growth performance in fattening pigs. We hypothesized that a low-CP diet with elevated EAA concentrations would result in similar growth performance in fattening pigs compared with a normal CP diet. Eighty finishing pigs with initial body weight (BW) of 72.0 ± 5.34 kg were assigned in a randomized complete block design with 5 replicates to test 4 dietary treatments: 1) 15.5% CP with EAA concentration at 109% of NRC requirement (control); 2) 14.0% CP with EAA concentration at 111% of NRC requirement (EAA111); 3) 14.0% CP with EAA concentration at 113% of NRC requirement (EAA113); and 14.0% CP with EAA concentration at 115% of NRC requirement (EAA115). The diets were isocaloric, whereas crystalline amino acids, L-Lys, L-Met, L-Thr, L-Trp, and L-Val were added to the diets to achieve the varying levels of EAA in the treatments. The Lys-to-net energy ratio in the diets was maintained at 3.06, 3.12, 3.18, and 3.24 to the control, EAA111, EAA113, and EAA115, respectively. Dietary treatments did not affect final BW. Additionally, average daily gain, average daily feed intake, and feed conversion ratio (FCR) were similar across the treatments. On average, pigs fed the control and EAA111 numerically decreased FCR compared to those fed EAA113 and 115 (3.21 vs. 3.35, respectively; P = 0.46). Total feed cost throughout the experiment was $9.0/head lessen in EAA111 relative to the control; however, total feed costs to EAA113 and EAA115 were greater than the control. In summary, a low-CP diet with increased EAA supplementations did not have any negative impact on growth performance of fattening pigs.

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Physical activity, quality of life and successful ageing among community-dwelling older adults

AIM

To identify the relationships between physical activity, quality of life and successful ageing among community-dwelling older adults in South Korea.

BACKGROUND

With increasing numbers of financially stable and active older adults, it has become imperative to understand successful ageing to promote well-being in this population.

METHODS

Questionnaire data were collected from senior welfare centres from August to November 2013. Participants were adults aged 65 years or older living in urban areas. Participants were asked to complete self-report questionnaires assessing physical activity, quality of life and successful ageing. Data from 212 participants were analysed using descriptive statistics, independent t-tests, ANOVAs with Scheffe tests and ordinary least square and quantile regression models using STATA 12.0.

FINDINGS

In the ordinary least square model, the association between physical activity and successful ageing was not statistically significant, whereas quantile regression revealed significant associations within the 75th and 90th percentiles of successful ageing scores. Quality of life was significantly associated with successful ageing in the ordinary least square model and with the median and 75th percentiles of successful ageing in quantile regressions.

CONCLUSION

Results suggested that physical activity and quality of life were both in part significantly associated with successful ageing among Korean older adults.

IMPLICATIONS FOR NURSING AND HEALTH POLICIES

Physical activity and quality of life play an important role in enhancing successful ageing. The development of an effective exercise programme advertised towards community-dwelling older adults may be essential for maintaining their successful ageing.

Decision Making by Young Transplant Surgeons Regarding Expanded-Criteria Donors With Acute Kidney Injury or Allocation Failure

BACKGROUND

The utilization of expanded-criteria donors (ECDs) has increased to overcome donor shortages. Unfortunately, the discard rate has also increased, especially in ECDs with acute kidney injury (AKI). We evaluated the outcomes of kidney transplantation in ECDs and standard-criteria donors (SCDs) with and without AKI.

METHODS

We reviewed the medical records of patients who underwent kidney transplantation. We used the AKI definition published by the Kidney Disease: Improving Global Outcomes group and reviewed the demographic characteristics of donors and recipients. We analyzed transplantation outcomes.

RESULTS

Twenty-seven patients underwent kidney transplantation from ECDs with AKI (n = 6) or without AKI (n = 5) and SCDs with AKI (n = 6) or without AKI (n = 10). Initial creatinine and estimated glomerular filtration rate (eGFR) were not significantly different between the groups. The incidence of delayed graft function was highest in ECDs with AKI (n = 3; 36.4%), but this was not a significantly difference. There was no difference in the last creatinine and eGFR in ECDs with AKI (1.32 mg/dL, 58.7 mL/min/1.73 m(2)), ECDs without AKI (1.67 mg/dL, 44.2 mL/min/1.73 m(2)), SCDs with AKI (0.94 mg/dL, 81.5 mL/min/1.73 m(2)) and SCDs without AKI (0.97 mg/dL, 81.8 mL/min/1.73 m(2)).

CONCLUSIONS

As the donor pool is extended to ECDs, young transplant surgeons may increasingly face decisions regarding ECDs with AKI or allocation failure. There is no consensus regarding discard criteria. However, if the donor showed initially normal creatinine levels or if dual-kidney transplantation can be performed, young transplant surgeons should not hesitate to use ECDs with AKI or allocation failure.

Calibration of time of flight detectors using laser-driven neutron source

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

On the analysis of inhomogeneous magnetic field spectrometer for laser-driven ion acceleration

We present a detailed study of the use of a non-parallel, inhomogeneous magnetic field spectrometer for the investigation of laser-accelerated ion beams. Employing a wedged yoke design, we demonstrate the feasibility of an in-situ self-calibration technique of the non-uniform magnetic field and show that high-precision measurements of ion energies are possible in a wide-angle configuration. We also discuss the implications of a stacked detector system for unambiguous identification of different ion species present in the ion beam and explore the feasibility of detection of high energy particles beyond 100 MeV/amu in radiation harsh environments.

A fall prevention guideline for older adults living in long-term care facilities

BACKGROUND

Falls are among the most frequent critical health problems for older adults over 65 years of age and often result in consequential injuries.

AIM

This study developed a guideline covering risk factors and interventions for falls in order to prevent them from occurring in long-term care facilities.

METHODS

This study was grounded in the methodological approach of the Scottish Intercollegiate Guideline Network for establishing evidence-based guidelines: (1) establishment of the target population and scope of the guideline, (2) systematic literature review and critical analysis, (3) determination of the recommendation grade, (4) development of a draft nursing intervention guideline and algorithm, (5) expert evaluation of the draft nursing intervention guideline, and (6) confirmation of the final intervention guideline and completion of the algorithm.

RESULTS

The resulting evidence-based fall prevention guideline consists of a three-step factor assessment and a three-step intervention approach.

LIMITATIONS

The resulting guideline was based on the literature and clinical experts. Further research is required to test the guideline's feasibility in across long term care facilities.

CONCLUSION

This guideline can be used by nurses to screen patients who are at a high risk of falling to provide patient interventions to help prevent falls.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Considering the high rate of falls at long-term care facilities and the absence of evidence-based guidelines to prevent them, additional studies on falls at long-term care facilities are necessary. Meanwhile, given prior research that indicates the importance of human resources in the application of such guidelines, continuous investigations are needed as to whether the research outcomes are actually conveyed to nurses.

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C(6+), O(8+), etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Factors associated with cognition recovery among elders with mild cognitive impairment in Korea

BACKGROUND

Of elders with mild cognitive impairment, around half recover their cognitive function at some point in time. However, very little is known about the factors that influence their cognitive change towards recovery.

AIM

This study evaluated the role of depression, instrumental activity of daily living and sleep quality as they affect cognition recovery among community-dwelling elders.

METHODS

The study follows a longitudinal comparative research design using secondary data analysis. Community-dwelling elders with mild cognitive impairment were assessed twice with a 1-year interval to assess their levels of cognition. Adult participants were drawn from those who visited a community health centre, were aged 65 or over and who were assessed as having MCI.

RESULTS

Those with mild cognitive impairment when compared with the normal cognition group were more likely to be younger, have more education, living with their spouses and had better cognitive function at baseline assessment than other participants. Predictors for cognitive recovery among elders with mild cognitive impairment were age, depression and cognitive function at baseline assessment.

LIMITATIONS

Participants included only those who visit a community health centre in an urban area of Korea, so the findings may not be applicable to other elders with less mobility or who live in rural areas.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

With the understanding that cognitive function and depression predict the recovery of mild cognitive function, nurses might be able to identify and target those older adults who are likely to achieve recovery of cognitive function. Additionally, health policy options, as suggested by the study as having the potential to improve mild cognitive impairment recovery, could include public education strategies.

Influence of malnutrition on the disposition of metronidazole in rats

The influence of dietary protein deficiency on the disposition of metronidazole and its two major metabolites was examined in male Sprague-Dawley rats fed for 4 weeks on a 23% (control-) or a 5% (low-) protein diet ad libitum. Following an intravenous bolus dose of 10 mg/kg metronidazole hydrochloride, blood samples were obtained serially for a period of 24 hr after drug administration. Serum concentration-time data were analyzed by nonlinear least-squares regression, as well as noncompartmental techniques. The average mean residence time (MRT) was significantly prolonged by 48%, while the systemic clearance (Cl) was decreased by 42% in the protein-deficient rats. Since there was no alteration in the apparent steady-state volume of distribution (V ss), the mean harmonic half-life was increased from 2.9 to 5.0 hr in the protein-deficient rats. Although the percentage of metronidazole recovered as total drug in the urine over 24 hr was not significantly different between the two groups of animals, rats on a low-protein diet excreted a significantly smaller percentage of the administered dose as unchanged metronidazole (mean ± SD, 24.6 ± 3.8 vs 36.5 ± 12%) and a larger percentage (16.7 ± 2.6 vs 8.3 ± 1.8%) as the hydroxylated metabolite. No significant difference in the partial metabolic clearance of the hydroxylated metabolite of metronidazole was seen between the two groups of animals; however, there was a significant decrease in the renal clearance of metronidazole (1.45 ± 0.68 vs 0.55 ± 0.06 ml/min/kg) in the rats fed a low-protein diet. We conclude that the decreased clearance of metronidazole in protein deficiency is a result primarily of the decreased glomerular filtration rate, decreased biliary excretion, and/or increased net tubular reabsorption of metronidazole.

Acute effects of an exposure to 100 ppm 1-methoxypropanol-2 on the upper airways of human subjects

The German MAK value of 1-methoxypropanol-2 has been fixed at 100 ppm. The aim of this study was to evaluate possible acute effects of an exposure to 100 ppm 1-methoxypropanol-2 on the upper airways of human subjects. Twenty subjects were exposed in a crossover design to 100 ppm 1-methoxypropanol-2 and to air in an exposure chamber for 4h. Subjective symptoms were assessed by questionnaire. Olfactory thresholds for n-butanol and mucociliary transport time were measured before and after exposure. Concentrations of interleukin 1β and interleukin 8 were determined in nasal secretions taken after exposure. mRNA levels of interleukins 1β, 6 and 8, tumor necrosis factor α, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1, and cyclooxygenases 1 and 2 were measured in nasal epithelial cells, obtained after exposure. Possible effects were investigated by semiparametric and parametric cross-over analyses. Subjects did not have any subjective irritating symptoms. The olfactory threshold was slightly elevated following exposure to 1-methoxypropanol-2. Mucociliary transport time did not change. Neither concentrations of interleukins in nasal secretions nor mRNA levels except for interleukin 1β were higher after exposure to 1-methoxypropanol-2. In conclusion, the acute exposure to 100 ppm 1-methoxypropanol-2 did not cause clear-cut adverse effects in test subjects.

Bright laser-driven neutron source based on the relativistic transparency of solids

Neutrons are unique particles to probe samples in many fields of research ranging from biology to material sciences to engineering and security applications. Access to bright, pulsed sources is currently limited to large accelerator facilities and there has been a growing need for compact sources over the recent years. Short pulse laser driven neutron sources could be a compact and relatively cheap way to produce neutrons with energies in excess of 10 MeV. For more than a decade experiments have tried to obtain neutron numbers sufficient for applications. Our recent experiments demonstrated an ion acceleration mechanism based on the concept of relativistic transparency. Using this new mechanism, we produced an intense beam of high energy (up to 170 MeV) deuterons directed into a Be converter to produce a forward peaked neutron flux with a record yield, on the order of 10(10)  n/sr. We present results comparing the two acceleration mechanisms and the first short pulse laser generated neutron radiograph.

Rayleigh-Taylor instability of an ultrathin foil accelerated by the radiation pressure of an intense laser

We report experimental evidence for a Rayleigh-Taylor-like instability driven by radiation pressure of an ultraintense (10(21) W/cm(2)) laser pulse. The instability is witnessed by the highly modulated profile of the accelerated proton beam produced when the laser irradiates a 5 nm diamondlike carbon (90% C, 10% H) target. Clear anticorrelation between bubblelike modulations of the proton beam and transmitted laser profile further demonstrate the role of the radiation pressure in modulating the foil. Measurements of the modulation wavelength, and of the acceleration from Doppler-broadening of back-reflected light, agree quantitatively with particle-in-cell simulations performed for our experimental parameters and which confirm the existence of this instability.

[Sport injuries and overuse damage of the elbow]

Sports injuries of the elbow joint can be acute or can arise due to chronic overuse. Such overstress syndromes are common in overhead, throwing and racket sports activities. The present article introduces diagnostic algorithms developed from knowledge gained through motion analysis, clinical examination and further imaging. The diagnosis of the overtaxing syndromes mainly depends on these findings. Basically most of the disorders in the elbow joint can be treated conservatively. If this is not the case or if the conservative treatment does not succeed, arthroscopic techniques, ligament reconstruction or nerve decompression are the major alternatives. The prognosis for regaining elbow function and returning to the previous level of performance is generally good. The resulting therapy recommendations are summarised on the basis of the current highest grades of evidence.

Monoenergetic ion beam generation by driving ion solitary waves with circularly polarized laser light

Experimental data from the Trident Laser facility is presented showing quasimonoenergetic carbon ions from nm-scaled foil targets with an energy spread of as low as ±15% at 35 MeV. These results and high-resolution kinetic simulations show laser acceleration of quasimonoenergetic ion beams by the generation of ion solitons with circularly polarized laser pulses (500 fs, λ=1054  nm). The conversion efficiency into monoenergetic ions is increased by an order of magnitude compared with previous experimental results, representing an important step towards applications such as ion fast ignition.

Three-dimensional dynamics of breakout afterburner ion acceleration using high-contrast short-pulse laser and nanoscale targets

Breakout afterburner (BOA) laser-ion acceleration has been demonstrated for the first time in the laboratory. In the BOA, an initially solid-density target undergoes relativistically induced transparency, initiating a period of enhanced ion acceleration. First-ever kinetic simulations of the BOA in three dimensions show that the ion beam forms lobes in the direction orthogonal to laser polarization and propagation. Analytic theory presented for the electron dynamics in the laser ponderomotive field explains how azimuthal symmetry breaks even for a symmetric laser intensity profile; these results are consistent with recent experiments at the Trident laser facility.

A low dielectric study on hybrid plasma-polymer thin films of different ratio between toluene and TEOS

Organic-inorganic hybrid co-polymer thin films were deposited on silicon(100) substrates under the several ratio of TEOS (tetraethoxysilane) against toluene by plasma enhanced chemical vapour deposition (PECVD) method. Toluene and TEOS were utilized as organic and inorganic precursors each, and hydrogen and argon were also used as a bubbler and carrier gases, respectively. In order to compare the difference of the electrical and the mechanical properties of the plasma polymerized thin films, we grew the hybrid co-polymer thin films under the conditions of various ratio between toluene and TEOS with fixed RF (radio frequency using 13.56 MHz) powers at 30 W. The as-grown polymerized thin films were in first analyzed by FT-IR and XPS. The result of FT-IR showed that the co-polymer thin films were polymerized with fragmented each precursor. Also, XPS results showed the chemical species and binding energies of each species. Si 2p core-level spectra from the hybrid polymer thin film showed the status of Si oxidation number. Impedance analyzer was utilized for the measurements of I-V curves and capacitance values. Also, the thin films were analyzed for hardness and Young's modulus by nano-indenter.

A novel high resolution ion wide angle spectrometer

A novel ion wide angle spectrometer (iWASP) has been developed, which is capable of measuring angularly resolved energy distributions of protons and a second ion species, such as carbon C(6 +), simultaneously. The energy resolution for protons and carbon ions is better than 10% at ∼50 MeV/nucleon and thus suitable for the study of novel laser-ion acceleration schemes aiming for ultrahigh particle energies. A wedged magnet design enables an acceptance angle of 30°(∼524 mrad) and high angular accuracy in the μrad range. First, results obtained at the LANL Trident laser facility are presented demonstrating high energy and angular resolution of this novel iWASP.

Development of a high resolution and high dispersion Thomson parabola

Here, we report on the development of a novel high resolution and high dispersion Thomson parabola for simultaneously resolving protons and low-Z ions of more than 100 MeV/nucleon necessary to explore novel laser ion acceleration schemes. High electric and magnetic fields enable energy resolutions of ΔE∕E < 5% at 100 MeV/nucleon and impede premature merging of different ion species at low energies on the detector plane. First results from laser driven ion acceleration experiments performed at the Trident Laser Facility demonstrate high resolution and superior species and charge state separation of this novel Thomson parabola for ion energies of more than 30 MeV/nucleon.

Pulse shape measurements using single shot-frequency resolved optical gating for high energy (80 J) short pulse (600 fs) laser

Relevant to laser based electron/ion accelerations, a single shot second harmonic generation frequency resolved optical gating (FROG) system has been developed to characterize laser pulses (80 J, ∼600 fs) incident on and transmitted through nanofoil targets, employing relay imaging, spatial filter, and partially coated glass substrates to reduce spatial nonuniformity and B-integral. The device can be completely aligned without using a pulsed laser source. Variations of incident pulse shape were measured from durations of 613 fs (nearly symmetric shape) to 571 fs (asymmetric shape with pre- or postpulse). The FROG measurements are consistent with independent spectral and autocorrelation measurements.

Caregiving appraisal of family caregivers for older stroke patients in Korea

PURPOSE

The purpose of this study was to investigate factors related to caregiving appraisal for family caregivers of older stroke patients in Korea.

METHOD

A descriptive, cross-sectional survey of a sample of 242 family caregivers (95.7% response rate) was conducted in Korea from 1 January 2005 to 4 January 2007. Data were collected from outpatient stroke centres at three hospitals and two home health agencies located in Seoul, the capital city of Korea, its suburban area of Kyunggi-do, and the rural areas Gyeongsangbuk-do and Chungcheongbuk-do. The questionnaire was self-administered. spss 13.0 (SPSS, Inc., Chicago, IL, USA) was used to perform frequency, percentage, mean standard deviation, t-test or analysis of variance, and Pearson's correlation calculations.

RESULTS

Caregiving appraisal was statistically different based on the caregiver's location of residency and the relationship between the caregiver and the recipient. The caregivers who resided in urban areas reported higher scores of caregiving appraisal compared with those who resided in rural areas. With regard to the caregiver-recipient relationship, spouses reported the highest caregiving distress status, followed by daughters-in-law, sons and, finally, daughters. In addition, caregiving distress significantly correlated with age (r = 0.151, P = 0.022), the number of caregiving hours per week (r = 0.198, P = 0.003) and filial obligations (r = 0.336, P = 0.000).

DISCUSSION

The study results helped to better understand the caregiving process of Korean family caregivers. The data emphasized the importance of examining the expression of cultural roles and individual values on the caregivers' quality of life in diverse cultures. The knowledge gained from this study will be utilized to develop culture-specific interventions and social policies to directly support Korean family caregivers and to indirectly support stroke patients.

The prevalence, characteristics and correlates of falls in Korean community-dwelling older adults

BACKGROUND

The risk factors for falls that have been reported in Caucasian older adults may not be the same for Korean older adults.

OBJECTIVE

To examine the prevalence, characteristics and correlates of falls among community-dwelling older adults in Korea.

METHODS

A stratified random sampling method was conducted to recruit participants, and 335 were eligible to participate from September 2006 to March 2007. Socio-demographic data, history of disease and medications, activities of daily living (ADL), cognitive status, health behaviour and fall incidents were collected. Descriptive statistics were used to describe the sample. The prevalence of falls was obtained. Univariate analyses for risk factors of falls using chi-square and t-test statistics, and multivariate logistic regression analyses for correlates of falls were performed.

RESULTS

Of the 335 older adults, 48 (15%) elderly had experienced falls. There was a significant difference between older adults who fell and those who did not fall with regard to ADL and exercise behaviour. Non-fallers had higher ADL scores and showed higher levels of adherence to exercise than fallers. The independent risk factor for falls was ADL.

CONCLUSIONS/IMPLICATIONS

In this study, an individual's functional status and exercise engagement were significant factors that differentiated fallers and non-fallers. Therefore, an effective fall prevention programme should be focused on encouraging older adults to participate in regular exercise.