AlGaAs/GaAs transverse junction stripe lasers with distributed feedback

Transverse junction stripe (TJS) lasers with periodic feedback were fabricated in two geometries. An interferometric and wet chemical etching technique was used to create a feedback grating across the entire pumping region for the distributed feedback (DFB) TJS laser and to create the separate distributed Bragg reflectors/DBR) for the TJS/DBR laser. The TJS/DFB laser was a double heterostructure device grown by liquid phase epitaxy (LPE) and had a third order grating etched in the top ALO.2GaO.8As layer. The grating was buried by growing an ALO.35GaO.65As layer on the grating by metal organic chemical vapor deposition (MO-CVD). The TJS/DBR laser was also fabricated in an LPE double heterostructure. The top AlGaAs layer was thinned to 0.1 micron over more than half of the laser so that the grating would be close to the GaAs active layer and optical field. Single mode operation in both configurations was obtained. The thermal shift of the laser wavelength in both cases was less than 1 Angstrom/deg K, compared to the 3 Angstrom/deg K shift of the spontaneous emission peak

Antibodies to decorin-binding protein B (DbpB) in the diagnosis of Lyme neuroborreliosis in children

Peer reviewe

Effects of Carbon Dioxide Aerosols on the Viability of Escherichia coli during Biofilm Dispersal

A periodic jet of carbon dioxide (CO2) aerosols is a very quick and effective mechanical technique to remove biofilms from various substrate surfaces. However, the impact of the aerosols on the viability of bacteria during treatment has never been evaluated. In this study, the effects of high-speed CO2 aerosols, a mixture of solid and gaseous CO2, on bacteria viability was studied. It was found that when CO2 aerosols were used to disperse biofilms of Escherichia coli, they led to a significant loss of viability, with approximately 50% of the dispersed bacteria killed in the process. By comparison, 75.6% of the biofilm-associated bacteria were viable when gently dispersed using Proteinase K and DNase I. Indirect proof that the aerosols are damaging the bacteria was found using a recombinant E. coli expressing the cyan fluorescent protein, as nearly half of the fluorescence was found in the supernatant after CO2 aerosol treatment, while the rest was associated with the bacterial pellet. In comparison, the supernatant fluorescence was only 9% when the enzymes were used to disperse the biofilm. As such, these CO2 aerosols not only remove biofilm-associated bacteria effectively but also significantly impact their viability by disrupting membrane integrity.open

Repetition and severity of suicide attempts across the life cycle: a comparison by age group between suicide victims and controls with severe depression

<p>Abstract</p> <p>Background</p> <p>Suicide attempts have been shown to be less common in older age groups, with repeated attempts generally being more common in younger age groups and severe attempts in older age groups. Consistently, most studies have shown an increased suicide risk after attempts in older age. However, little is known about the predictive value of age on repeated and severe suicide attempts for accomplished suicide. The aim of the present study was to investigate the reduced incidence for initial, repeated, or severe suicide attempts with age in suicide victims and controls by gender.</p> <p>Methods</p> <p>The records of 100 suicide victims and matched controls with severe depression admitted to the Department of Psychiatry, Lund University Hospital, Sweden between 1956 and 1969, were evaluated and the subjects were monitored up to 2006. The occurrence of suicide attempts (first, repeated, or severe, by age group) was analysed for suicide victims and controls, with gender taken into consideration.</p> <p>Results</p> <p>There was a reduced risk for an initial suicide attempt by older age in females (suicide victims and controls) and male controls (but not suicide victims). The risk for repeated suicide attempts appeared to be reduced in the older age groups in female controls as compared to female suicide victims. The risk for severe suicide attempts seemed reduced in the older age groups in female suicide victims. This risk was also reduced in male controls and in male controls compared to male suicide victims.</p> <p>Conclusion</p> <p>In the older age groups repeated attempts appeared to be predictive for suicide in women and severe attempts predictive in men.</p

Occurrence of erythema migrans in children with Lyme neuroborreliosis and the association with clinical characteristics and outcome - a prospective cohort study

Background: Erythema migrans (EM) is the most common manifestation of Lyme borreliosis (LB), caused by the spirochete Borrelia burgdorferi sensu lato. The infection can disseminate into the nervous system and cause Lyme neuroborreliosis (LNB), the second most frequent LB manifestation in children. The aim of this prospective cohort study is to describe the occurrence of EM among children with LNB and to evaluate possible differences in clinical characteristics or outcome between LNB patients with and without EM. Method: Children being evaluated for LNB in southeast Sweden during the period 2010-2014 underwent a clinical examination, laboratory testing and filled out a questionnaire regarding duration and nature of symptoms, EM and the child's health. Children were classified according to European guidelines for LNB. Clinical recovery was evaluated at a 2-month follow-up. Results: The occurrence of EM among children with LNB was 37 out of 103 (36%). Gender, age, observed tick bite, clinical features, duration of neurological symptoms or clinical outcome did not differ significantly between LNB patients with or without EM. However, facial nerve palsy was significantly more common among children with EM in the head and neck area. Conclusion: EM occurred in 36% of children with LNB and the location on the head and neck was more common among children with facial nerve palsy. EM was not associated with other specific clinical characteristics or outcome. Thus, the occurrence of EM in children with LNB cannot be useful as a prognostic factor for clinical outcome. This aspect has not previously been highlighted but seems to be relevant for the paediatrician in a clinical setting

The NeBoP score - a clinical prediction test for evaluation of children with Lyme Neuroborreliosis in Europe

Background: The diagnosis of Lyme neuroborreliosis (LNB) in Europe is based on clinical symptoms and laboratory data, such as pleocytosis and anti-Borrelia antibodies in serum and CSF according to guidelines. However, the decision to start antibiotic treatment on admission cannot be based on Borrelia serology since results are not available at the time of lumbar puncture. Therefore, an early prediction test would be useful in clinical practice. The aim of the study was to develop and evaluate a clinical prediction test for children with LNB in a relevant European setting. Method: Clinical and laboratory data were collected retrospectively from a cohort of children being evaluated for LNB in Southeast Sweden. A clinical neuroborreliosis prediction test, the NeBoP score, was designed to differentiate between a high and a low risk of having LNB. The NeBoP score was then prospectively validated in a cohort of children being evaluated for LNB in Central and Southeast Sweden (n = 190) and controls with other specific diagnoses (n = 49). Results: The sensitivity of the NeBoP score was 90 % (CI 95 %; 82-99 %) and the specificity was 90 % (CI 95 %; 85-96 %). Thus, the diagnostic accuracy (i.e. how the test correctly discriminates patients from controls) was 90 % and the area under the curve in a ROC analysis was 0.95. The positive predictive value (PPV) was 0.83 (CI 95 %; 0.75-0.93) and the negative predictive value (NPV) was 0.95 (CI 95 %; 0.90-0.99). Conclusion: The overall diagnostic performance of the NeBoP score is high (90 %) and the test is suggested to be useful for decision-making about early antibiotic treatment in children being evaluated for LNB in European Lyme endemic areas.Funding Agencies|Center of Clinical Research Dalarna (CKF); Swedish Society of Medicine; Research Council in the Uppsala-Orebro region (RFR); Samaritan Foundation; Lions Foundation</p

Seroprevalence of Borrelia IgG antibodies among young Swedish children in relation to reported tick bites, symptoms and previous treatment for Lyme borreliosis: a population-based survey

Background Lyme borreliosis (LB) is the most common tickborne infection in Sweden and the seroprevalence of Borrelia immunoglobulin G (IgG) antibodies varies between 2% and 26%. The seroprevalence in young Swedish children is unknown and the relation to clinical data has not been previously studied. Objective To determine the seroprevalence of Borrelia IgG antibodies in serum of young Swedish children and to relate it to gender, geographical location, reported tick bites, symptoms and previous treatment for LB. Methods 2000 healthy 5-year-old children (n=2000) were randomly selected from among participants of a larger prospective population-based study, the ABIS (All Babies in Southeast Sweden) study. Serum samples were collected and a Borrelia specific ELISA test (Dako) were performed for IgG antibody detection. Clinical data were collected from questionnaires completed by the parents. Results The seroprevalence of Borrelia IgG antibodies was 3.2% (64/2000). Previous tick bite had been noted in 66% of these seropositive children but the majority (94%) had not previously been treated for LB. In addition, another 55 children reported a history of LB but were negative to Borrelia IgG antibodies in serum. Many of these seronegative children had received treatment for erythema migrans (n=24), which is a clinical diagnosis. Whether children were correctly treated or overtreated for LB is however unknown. No differences in gender, geographical location or reported tick bites were found when comparing Borrelia-seropositive children (n=64) and seronegative children with previous LB (n=55). Conclusion This population-based study demonstrates a Borrelia IgG antibody seroprevalence of 3.2% in young Swedish children. Very few of these seropositive children report previous symptoms or treatment for LB. Thus the findings suggest that exposure to the Borrelia spirochaete (with subsequent antibody response in serum) does occur in young children, mostly without giving rise to clinical LB. Future studies on cell-mediated immune responses are needed to investigate explanatory immunological mechanisms.Original Publication: Barbro H Skogman, Christina Ekerfelt, Johnny Ludvigsson and Pia Forsberg, Seroprevalence of Borrelia IgG antibodies among young Swedish children in relation to reported tick bites, symptoms and previous treatment for Lyme borreliosis: a population-based survey, 2010, ARCHIVES OF DISEASE IN CHILDHOOD, (95), 12, 1013-1016. http://dx.doi.org/10.1136/adc.2010.183624 Copyright: BMJ Publishing Group http://group.bmj.com