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Atherosclerotic changes can be measured as changes in common carotid intima media thickness (CIMT). It is hypothesised that repeated infection-associated inflammatory responses in childhood contribute to the atherosclerotic process. We set out to determine whether the frequency of infectious diseases in childhood is associated with CIMT in adolescence. The study is part of the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) population-based birth cohort. At age 16 years, common CIMT was measured. We collected general practitioner (GP) diagnosed infections and prescribed antibiotics. Parent-reported infections were retrieved from annual questionnaires. Linear regression analysis assessed the association between number of infections during the first 4 years of life and common CIMT. Common CIMT measurement, GP and questionnaire data were available for 221 participants. No association was observed between the infection measures and CIMT. In a subgroup analysis, significant positive associations with CIMT were observed in participants with low parental education for 2–3 or ⩾7 GP diagnosed infections (+26.4 µm, 95% CI 0.4–52.4 and +26.8 µm, 95% CI 3.6–49.9, respectively) and ⩾3 antibiotic prescriptions (+35.5 µm, 95%CI 15.8–55.3). Overall, early childhood infections were not associated with common CIMT in adolescence. However, a higher number of childhood infections might contribute to the inflammatory process of atherosclerosis in subgroups with low education, this needs to be confirmed in future studies.
Congenital cytomegalovirus infection (cCMV) may lead to symptoms at birth and long-term consequences. We present a nationwide, retrospective cohort study on the outcome of cCMV up to age 6 years. For this study we identified cCMV, using polymerase chain reaction, by analysing dried blood spots, which are taken shortly after birth for neonatal screening. The group of children with cCMV were compared to a group of children who were cCMV negative at birth. Data were collected about their health and development up to age 6 years. Parents of 73 693 children were invited to participate, and 32 486 (44·1%) gave informed consent for testing of their child's dried blood spot for CMV. Of the 31 484 dried blood spots tested, 156 (0·5%) were positive for cCMV. Of these, four (2·6%) children had been diagnosed with cCMV prior to this study. This unique retrospective nationwide study permits the estimation of long-term sequelae of cCMV up to the age of 6 years. The birth prevalence of cCMV in this study was 0·5%, which is in line with prior estimates. Most (97·4%) children with cCMV had not been diagnosed earlier, indicating under-diagnosis of cCMV.
Gonorrhoea is one of the most common sexually transmitted infections. The control of gonorrhoea is extremely challenging because of the repeated development of resistance to the antibiotics used for its treatment. We explored different strategies to control the spread of antimicrobial resistance and prevent increases in gonorrhoea prevalence. We used a mathematical model that describes gonorrhoea transmission among men who have sex with men and distinguishes gonorrhoea strains sensitive or resistant to three antibiotics. We investigated the impact of combination therapy, switching first-line antibiotics according to resistance thresholds, and other control efforts (reduced sexual risk behaviour, increased treatment rate). Combination therapy can delay the spread of resistance better than using the 5% resistance threshold. Increased treatment rates, expected to enhance gonorrhoea control, may reduce gonorrhoea prevalence only in the short term, but could lead to more resistance and higher prevalence in the long term. Re-treatment of resistant cases with alternative antibiotics can substantially delay the spread of resistance. In conclusion, combination therapy and re-treatment of resistant cases with alternative antibiotics could be the most effective strategies to prevent increases in gonorrhoea prevalence due to antimicrobial resistance.
Autism spectrum disorder (ASD) is characterised by deficits in the ability to socialise, communicate and use imagination, and displays of stereotypical behaviour. It is widely accepted that ASD involves a disorder in brain development. However, the real causes of the neurodevelopmental disorders associated with ASD are not clear. In this respect, it has been found that a majority of children with ASD display gastrointestinal symptoms, and an increased intestinal permeability. Moreover, large differences in microbiotic composition between ASD patients and controls have been reported. Therefore, nutrition-related factors have been hypothesised to play a causal role in the aetiology of ASD and its symptoms. Through a review of the literature, it was found that abnormalities in carbohydrate digestion and absorption could explain some of the gastrointestinal problems observed in a subset of ASD patients, although their role in the neurological and behavioural problems remains uncertain. In addition, the relationship between an improved gut health and a reduction of symptoms in some patients was evaluated. Recent trials involving gluten-free diets, casein-free diets, and pre- and probiotic, and multivitamin supplementation show contradictive but promising results. It can be concluded that nutrition and other environmental influences might trigger an unstable base of genetic predisposition, which may lead to the development of autism, at least in a subset of ASD patients. Clear directions for further research to improve diagnosis and treatment for the different subsets of the disorder are provided.
The photoluminescence and Raman spectra of several Ga1−xAlxN layers (0 ≤ x ≤ 0.86) grown on sapphire substrates by metal-organic vapor phase epitaxy have been recorded at room temperature, under an excitation at 244 nm. Using the photoluminescence spectra, the variation of the band gap of these alloys can be followed only up to x = 0.5. From resonant Raman scattering, it can be deduced that the band gap energy of the solid solution for x very close to 0.7 corresponds to the incident photon energy (5.08 eV). This result is confirmed by a detailed comparison of the present work with previous experimental data on the A1(LO) phonon peak position, obtained under visible excitation.
This essay places transnational environmental law in an epistemological context. Starting from the general concept of ‘transnational law’ and the specific environmental dimension of ‘international administrative law’, four case histories are presented to illustrate the integrant approach of transnational environmental law. The cases – all arising in the 1970s – deal with transboundary problems of aircraft noise, ocean dumping, river pollution, and marine protected areas. In addition to traditional aspects of public international law in the environmental field, they typically interface with questions of administrative law, private international law, criminal law, and human rights law. The essay advocates a new focus on mechanisms for participation by civil society in the operation and implementation of transnational environmental law.
Short-term structured risk assessment is presumed to reduce incidents of aggression and seclusion on acute psychiatric wards. Controlled studies of this approach are scarce.
To evaluate the effect of risk assessment on the number of aggression incidents and time in seclusion for patients admitted to acute psychiatric wards.
A cluster randomised controlled trial was conducted in four wards over a 40-week period (n = 597 patients). Structured risk assessment scales were used on two experimental wards, and the numbers of incidents of aggression and seclusion were compared with two control wards where assessment was based purely on clinical judgement.
The numbers of aggressive incidents (relative risk reduction −68%, P<0.001) and of patients engaging in aggression (relative risk reduction RRR =–50%, P<0.05) and the time spent in seclusion (RRR =–45%, P<0.05) were significantly lower in the experimental wards than in the control wards. Neither the number of seclusions nor the number of patients exposed to seclusion decreased.
Routine application of structured risk assessment measures might help reduce incidents of aggression and use of restraint and seclusion in psychiatric wards.
We aimed to assess differences in the prevalence of hepatitis B virus (HBV) infection in The Netherlands between 1996 and 2007, and to identify risk factors for HBV infection in 2007. Representative samples of the Dutch population in 1996 and 2007 were tested for antibodies to hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg) and HBV-DNA. In 2007, the weighted anti-HBc prevalence was 3·5% (95% CI 2·2–5·5) and the HBsAg prevalence was 0·2% (95% CI 0·1–0·4). In indigenous Dutch participants, the anti-HBc prevalence was lower in 2007 than in 1996 (P=0·06). First-generation migrants (FGMs) had a 13-fold greater risk of being HBsAg- and/or HBV-DNA-positive than indigenous Dutch participants. In indigenous Dutch participants, risk factors for anti-HBc positivity were older age and having received a blood product before 1990. In FGMs, being of Asian origin was a risk factor. In second-generation migrants, having a foreign-born partner and injecting drug use were risk factors. FGMs are the main target group for secondary HBV prevention in The Netherlands.
Relaxed, high Ge content SiGe layers have been realized using stress balance on acompliant borophosphorosilicate glass (BPSG). A 30-nm fully-strained Si0.7Ge0.3 layer wastransferred onto a 1 μm BPSG film by wafer-bonding and Smart-cutρ processes, after which thecontinuous Si0.7Ge0.3 film was patterned into small islands to allow for lateral expansion. Afterthe strain in Si0.7Ge0.3 islands was released by the lateral expansion resulting from the flow of theBPSG, a Si0.4Ge0.6 layer was commensurately deposited under compression. Upon equilibriumafter an annealing, stress balance was formed between the SiGe films, resulting in a larger inplanelattice constant than that of relaxed Si0.7Ge0.3. With a thiner (6 nm) Si0.7Ge0.3 starting film,an in-plane lattice constant equivalent to fully-relaxed Si0.45Ge0.55 has been obtained.
Ethnic disparities in chlamydia infections in The Netherlands were assessed, in order to compare two definitions of ethnicity: ethnicity based on country of birth and self-defined ethnicity. Chlamydia positivity in persons aged 16–29 years was investigated using data from the first round of the Chlamydia Screening Implementation (CSI, 2008–2009) and surveillance data from STI centres (2009). Logistic regression modelling showed that being an immigrant was associated with chlamydia positivity in both CSI [adjusted odds ratio (aOR) 2·3, 95% confidence interval (CI) 2·0–2·6] and STI centres (aOR 1·4, 95% CI 1·3–1·5). In both settings, 60% of immigrants defined themselves as Dutch. Despite the difference, classification by self-defined ethnicity resulted in similar associations between (non-Dutch) ethnicity and chlamydia positivity. However, ethnicity based on country of birth explained variation in chlamydia positivity better, and is objective and constant over time and therefore more useful for identifying young persons at higher risk for chlamydia infection.
Fluorescence detection in integrated micro-bioanalytical systems requires the selective exclusion of light from the excitation source (typically blue or UV) and transmission of the longer wavelength fluorescence signal. In the present research, the application of (In,Ga)N alloy thin films as optical filters for absorption of blue (470 nm) and transmission of green (530 nm) has been evaluated. Absorption spectra, photoluminescence (PL) and Rutherford backscattering spectroscopy (RBS) results are presented for 200-400 nm (In,Ga)N thin films grown by MOCVD on sapphire substrates with 2-4 μm GaN buffer layers. A sigmoidal function was used to model the absorption coefficient of (In,Ga)N as a function of energy, Eg, and the broadening (ΔE) associated with the Urbach tail. Experimental data showed that, as expected, the absorption band edge for (In,Ga)N films broadened with increasing InN mole%. An increase in ΔE of 35 meV was observed when the InN mole% was increased from 10 to 16%. The sigmoidal function model provided a good fit to the experimental data, which allowed the experimental data to be extrapolated to higher InN concentrations. Based on this analysis, it is predicted that a 5 μm thick In0.22Ga0.78N film should transmit 50% of green light (530 nm) and only 3.29 x 1 0-4 of blue light (470 nm). The (In,Ga)N films that have been evaluated range in InN mole% from ~2-16%. The higher InN mole% samples (10-16%) can successfully filter lower wavelengths (e.g., 400 nm). For a filter application, it is also important that photoluminescence be effectively suppressed. In MQW structures, high PL intensity is often obtained by means of InN segregation (InN-rich nanoclusters). But for our evaluation with 200-400 nm (In,Ga)N films, relaxation of coherency strain results in large densities of dislocations, and correspondingly low PL intensity.
Sputter-deposited piezoelectric lead zirconate titanate (PZT) thin films with Ti/Pt and polysilicon electrode layers are being investigated for use in Microelectromechanical Systems (MEMS). Existing research shows the nucleation of the perovskite phase of the PZT is linked to the lattice spacing of the underlying Pt electrode and/or seed layers, and is key in obtaining PZT layers with good piezoelectric/ferroelectric properties. Our research with piezoelectric PZT films on Ti/Pt electrode layers aims at employing these films to generate and receive acoustic waves in flexural plate wave devices (FPWs). Our experiments indicate the formation of a random polycrystalline perovskite phase is linked to the emergence of oriented <100> Pt grains within the dominant <111>-oriented crystal structure during rapid thermal annealing in an oxygen environment. Pt films annealed in nitrogen, in contrast, retained their <111> preferential orientation without the formation of Pt <100> grains. PZT films deposited on these electrodes and annealed in nitrogen were strongly oriented in the <111> direction, but exhibited lossy ferroelectric behavior and were prone to delamination. We are also investigating the feasibility of using doped polysilicon electrode layers with PZT thin films. The multiple layers used with the Pt electrode (Pt, Ti, and SiO2 adhesion layer) have significant interactions with one another, and replacing these layers with a single electrode layer should alleviate these complications. A low-temperature PZT deposition process (300°C) and short annealing cycles (30 sec.), coupled with a TiO2 barrier/seed layer should prevent interdiffusion and reactions between the polysilicon and PZT layers. Our experiments show that PZT films deposited and annealed on doped polysilicon layers develop a random polycrystalline perovskite phase, but are subject to tensile cracking. The use of polysilicon as an electrode layer should also facilitate the integration of piezoelectric PZT layers with polysilicon surface micromachined structures using SiGe sacrificial layers.