Monolithic single mode interband cascade lasers with wide wavelength tunability

Financial support by the European Union in terms of the WideLase project (grant agreement no: 318798) within the Seventh Framework Programme is gratefully acknowledged.Monolithic two-section interband cascade lasers offering a wide wavelength tunability in the wavelength range around 3.7 μm are presented. Stable single mode emission in several wavelength channels was realized using the concept of binary superimposed gratings and two-segment Vernier-tuning. The wavelength selective elements in the two segments were based on specially designed lateral metal grating structures defined by electron beam lithography. A dual-step dry etch process provided electrical separation between the segments. Individual current control of the segments allowed wavelength channel selection as well as continuous wavelength tuning within channels. A discontinuous tuning range extending over 158 nm in up to six discrete wavelength channels was achieved. Mode hop free wavelength tuning up to 14 nm was observed within one channel. The devices can be operated in continuous wave mode up to 30 °C with output powers of 3.5 mW around room temperature.PostprintPeer reviewe

Vitamin C supplementation in nicotine use during pregnancy: A narrative review

Abstract Nicotine use during pregnancy remains a widespread problem in obstetrics, leading to complications such as intrauterine growth restriction, preterm birth, stillbirth, and sudden infant death syndrome. Consistent education by medical personnel is essential, as no medication or supplement has been found to prevent the dangers of nicotine use during pregnancy. If a pregnant woman is unable to quit nicotine despite intensive efforts, vitamin C, with its antioxidant properties, may help mitigate these risks, as suggested by some studies. This review summarizes current knowledge based on publications related to vitamin C, nicotine, and pregnancy. Research was conducted on the medical literature platforms PubMed and Cochrane Library, using all relevant studies to provide a comprehensive overview of the topic. The identified studies primarily examined the impact of maternal smoking and nicotine on placental function, as well as the respiratory, cardiac, neuronal, and bone systems of the offspring. They suggest that vitamin C has a generally positive preventive or protective effect, though no study has shown complete compensation for the damage caused by nicotine. Nicotine abstinence remains the most crucial preventive measure. If this is not achievable despite intensive efforts by medical personnel, vitamin C supplementation during pregnancy may be considered. With a very low side effect profile, a daily dose of up to 500 mg can be recommended. However, further studies are necessary to provide reliable data on the effectiveness and appropriate dosage, given an ethically justifiable study approach.Plain language summary This review looks at how vitamin C might protect against the harmful effects of smoking during pregnancy, based on previously published scientific papers. Why was the study done? Nicotine use during pregnancy poses significant risks, including restricted fetal growth, preterm birth, stillbirth, and sudden infant death syndrome. Despite efforts to educate pregnant women about these dangers, nicotine use remains common. No medication or supplement has yet been identified to effectively counteract these risks. However, there is emerging research suggesting that vitamin C, known for its antioxidant properties, could help reduce the negative impacts of nicotine use during pregnancy. This review was conducted to explore the current state of research on this topic. What did the researchers do? The authors reviewed existing studies that focused on the effects of maternal nicotine use and the potential protective role of vitamin C supplementation. The studies primarily examined the impact on the placenta, as well as the respiratory, cardiac, and neuronal systems of offspring exposed to maternal smoking. They sought to determine whether vitamin C could prevent or reduce the harm caused by nicotine exposure during pregnancy. What did the researchers find? The studies reviewed showed generally positive results, indicating that vitamin C supplementation may have a protective effect against some of the damage caused by nicotine use during pregnancy. However, none of the studies demonstrated complete compensation for the harm caused by nicotine. The researchers suggested that a daily dose of 500 mg of vitamin C during pregnancy might offer some benefit, particularly for women who feel unable to quit smoking. At this dosage, no significant side effects are expected. What do the findings mean? While the best way to prevent nicotine-related complications during pregnancy is still to quit smoking, vitamin C supplementation may be a helpful adjunctive measure for pregnant women who struggle to stop smoking. The findings point to the need for further research to better understand the effectiveness and appropriate dosage of vitamin C, using ethically sound study designs to explore this potential intervention

TERRAIN PREDICTION WITH A LOW-COST LIDAR SENSOR FOR MOBILE ROBOTS

Terrain modelling influences various aspects of mobile robot navigation. The ability to explore in rough terrain and to recognise ground conditions are essential to perform different activities efficiently, safely and satisfactorily. For this reason, intelligent vehicles and robotic systems need cognitive capabilities to understand the terrain and derive information from it. The information is mostly acquired and processed by very high resolution 3D-cameras and LiDAR sensors which provide full 360-degree environmental view to deliver accurate 3D data. The aim of this paper is to find out whether a low-cost sensor variant can measure sufficient and significant data from the terrain in order to modify the navigation behaviour and provide the correct control commands. In this paper we describe a low-cost sensor with Infrared Time-of-Flight (ToF) technology and 64 pixel depth image. Furthermore, different experiments on the detection of the sensor were conducted and with appropriate filters and signal processing algorithms the environmental perception could be significantly improved. In summary, our results provide both evidence and guidelines for the use of the selected sensor in environmental perception to improve local obstacle detection and terrain modelling, which we believe will lead to a very cost-effective improvement in competence and situational awareness

Demonstration of the self-mixing effect in interband cascade lasers

In this Letter, we demonstrate the self-mixing effect in an interband cascade laser. We show that a viable self-mixing signal can be acquired through the variation in voltage across the laser terminals, thereby removing the need for an external detector. Using this interferometric technique, we have measured the displacement of a remote target, and also demonstrated high resolution imaging of a target. The proposed scheme represents a highly sensitive, compact, and self-aligned sensing technique with potential for materials analysis in the mid-infrared. (C) 2013 AIP Publishing LLC

Effectiveness of second generation antipsychotics: A systematic review of randomized trials

<p>Abstract</p> <p>Background</p> <p>Systematic reviews based on efficacy trials are inconclusive about which second generation antipsychotic drug (SGA) should be preferred in normal clinical practice, and studies with longer duration and more pragmatic designs are called for. Effectiveness studies, also known as naturalistic, pragmatic, practical or real life studies, adhere to these principles as they aim to mimic daily clinical practice and have longer follow-up.</p> <p>Objective</p> <p>To review the head-to-head effectiveness of SGAs in the domains of global outcomes, symptoms of disease, and tolerability.</p> <p>Methods</p> <p>Searches were made in Embase, PubMED, and the Cochrane central register of controlled trials for effectiveness studies published from 1980 to 2008, week 1. Different combinations of the keywords <it>antipsychotic*, neuroleptic* AND open, pragmatic, practical, naturalistic, real life, effectiveness, side effect*, unwanted effect*, tolera* AND compar* AND random* </it>were used.</p> <p>Results</p> <p>Sixteen different reports of randomized head-to-head comparisons of SGA effectiveness were located. There were differences regarding sample sizes, inclusion criteria and follow-up periods, as well as sources of financial sponsorship. In acute-phase and first-episode patients no differences between the SGAs were disclosed regarding alleviating symptoms of disease. Olanzapine was associated with more weight gain and adverse effects on serum lipids. In the chronic phase patients olanzapine groups had longer time to discontinuation of treatment and better treatment adherence compared to other SGAs. The majority of studies found no differences between the SGAs in alleviating symptoms of psychosis in chronically ill patients. Olanzapine was associated with more metabolic adverse effects compared to the others SGAs. There were surprisingly few between-drug differences regarding side effects. First generation antipsychotics were associated with lower total mental health care costs in 2 of 3 studies on chronically ill patients, but were also associated with more extrapyramidal side effects compared to the SGAs in several studies.</p> <p>Conclusion</p> <p>In chronically ill patients olanzapine may have an advantage over other SGAs regarding longer time to treatment discontinuation and better drug adherence, but the drug is also associated with more metabolic side effects. More effectiveness studies on first-episode psychosis are needed.</p

Burden of onchocerciasis-associated epilepsy: First estimates and research priorities

__Background:__ Since the 1990s, evidence has accumulated of an increased prevalence of epilepsy in onchocerciasis-endemic areas in Africa as compared to onchocerciasis-free areas. Although the causal relationship between onchocerciasis and epilepsy has yet to be proven, there is likely an association.

Genome-wide association analyses of symptom severity among clozapine-treated patients with schizophrenia spectrum disorders

Clozapine is the most effective antipsychotic for patients with treatment-resistant schizophrenia. However, response is highly variable and possible genetic underpinnings of this variability remain unknown. Here, we performed polygenic risk score (PRS) analyses to estimate the amount of variance in symptom severity among clozapine-treated patients explained by PRSs (R2) and examined the association between symptom severity and genotype-predicted CYP1A2, CYP2D6, and CYP2C19 enzyme activity. Genome-wide association (GWA) analyses were performed to explore loci associated with symptom severity. A multicenter cohort of 804 patients (after quality control N = 684) with schizophrenia spectrum disorder treated with clozapine were cross-sectionally assessed using the Positive and Negative Syndrome Scale and/or the Clinical Global Impression-Severity (CGI-S) scale. GWA and PRS regression analyses were conducted. Genotype-predicted CYP1A2, CYP2D6, and CYP2C19 enzyme activities were calculated. Schizophrenia-PRS was most significantly and positively associated with low symptom severity (p = 1.03 × 10−3; R2 = 1.85). Cross-disorder-PRS was also positively associated with lower CGI-S score (p = 0.01; R2 = 0.81). Compared to the lowest tertile, patients in the highest schizophrenia-PRS tertile had 1.94 times (p = 6.84×10−4) increased probability of low symptom severity. Higher genotype-predicted CYP2C19 enzyme activity was independently associated with lower symptom severity (p = 8.44×10−3). While no locus surpassed the genome-wide significance threshold, rs1923778 within NFIB showed a suggestive association (p = 3.78×10−7) with symptom severity. We show that high schizophrenia-PRS and genotype-predicted CYP2C19 enzyme activity are independently associated with lower symptom severity among individuals treated with clozapine. Our findings open avenues for future pharmacogenomic projects investigating the potential of PRS and genotype-predicted CYP-activity in schizophrenia