[Fractures of the lateral condyle of the humerus in children : High risk of secondary dislocation with conservative treatment]

BACKGROUND

Fractures of the lateral condyle of the humerus in children are articular fractures with difficult diagnostics due to the incompletely ossified elbow joint. The aim of this study was to evaluate the method of treatment at initial presentation and to analyze the frequency of subsequent displacement during follow-up.

MATERIAL AND METHOD

Retrospective analysis of the frequency of primary fracture dislocation and subsequent displacement of fractures of the lateral condyle of the humerus in children under 16 years of age between 2004 and 2021. Conventional radiographs in two planes at the time of the accident and in the follow-up after 5-7 days were evaluated.

RESULTS

A total of 285 fractures of the lateral condyle of the humerus were evaluated. The average age was 5.3 years. Of the fractures 109 (38.3%) were directly surgically treated in cases of primary displacement and 176 fractures (61.7%) were not primarily displaced and were initially treated conservatively. During follow-up, subsequent displacement was evident in 46 fractures (26.1%). A total of 130 fractures (45.6%) were treated conservatively and 155 fractures (54.4%) were treated surgically using open joint visualization and screw osteosynthesis or K‑wire osteosynthesis.

CONCLUSION

Fractures of the lateral condyle of the humerus occur more frequently in a certain age group and require targeted radiological diagnostics. Nondisplaced fractures can be treated conservatively but essential radiological follow-up shows a high number of subsequent displacements, so that open surgical stabilization is often necessary.

Revealing the quantum nature of the voltage-induced conductance changes in oxygen engineered yttrium oxide-based RRAM devices

In this work, the quasi-analog to discrete transition occurring in the current-voltage characteristic of oxygen engineered yttrium oxide-based resistive random-access memory (RRAM) devices is investigated in detail. In particular, the focus of our research is not on the absolute conductance values of this characteristic but on the magnitude of its conductance changes occurring during the reset process of the device. It is found that the detected changes correspond to conductance values predominantly of the order of the quantum unit of conductance G0 = 2e2/h, where e is the electron charge and h the Planck constant. This feature is observed even at conductance levels far above G0, i.e. where electron transport is seemingly diffusive. It is also observed that such behavior is reproducible across devices comprising yttrium oxide layers with different oxygen concentrations and measured under different voltage sweep rates. While the oxygen deficiency affects the total number of quantized conductance states, the magnitude of the changes in conductance, close to 1 G0, is invariant to the oxygen content of the functional layer.

Prior Vaccination Exceeds Prior Infection in Eliciting Innate and Humoral Immune Responses in Omicron Infected Outpatients

Antibody response following Omicron infection is reported to be less robust than that to other variants. Here we investigated how prior vaccination and/or prior infection modulates that response. Disease severity, antibody responses and immune transcriptomes were characterized in four groups of Omicron-infected outpatients (n=83): unvaccinated/no prior infection, vaccinated/no prior infection, unvaccinated/prior infection and vaccinated/prior infection. The percentage of patients with asymptomatic or mild disease was highest in the vaccinated/no prior infection group (87%) and lowest in the unvaccinated/no prior infection group (47%). Significant anti-Omicron spike antibody levels and neutralizing activity were detected in the vaccinated group immediately after infection but were not present in the unvaccinated/no prior infection group. Within two weeks, antibody levels against Omicron, increased. Omicron neutralizing activity in the vaccinated group exceeded that of the prior infection group. No increase in neutralizing activity in the unvaccinated/no prior infection group was seen. The unvaccinated/prior infection group showed an intermediate response. We then investigated the early transcriptomic response following Omicron infection in these outpatient populations and compared it to that found in unvaccinated hospitalized patients with Alpha infection. Omicron infected patients showed a gradient of transcriptional response dependent upon whether or not they were previously vaccinated or infected. Vaccinated patients showed a significantly blunted interferon response as compared to both unvaccinated Omicron infected outpatients and unvaccinated Alpha infected hospitalized patients typified by the response of specific gene classes such as OAS and IFIT that control anti-viral responses and IFI27, a predictor of disease outcome.

Study of the possibility of high accuracy flow measurements with the pulsed neutron activation method

The performance of water flow measurements with pulsed neutron activation (PNA) have been investigated in the past few years. In this report the following particular Problems were investigated: (a) the effect of collimation on the time-resolved detector signals; (b) the behavior of the background signal, in order to expedite optimum background elimination from the measured signals; and (c) the properties of water mixing, by measuring the geometrical asymmetry of the activated volume as a function of distance from the source as well as of flow velocity. It was seen that with the flow velocities and Reynolds numbers in the present experiments, the mixing is not perfect. Thus, in general, the PNA method will lead to an underestimation of the mass flow due to the effect of the laminar layer close to the wall whose contribution to the total mass flow will be enhanced. The investigations reported here contribute to the improvement of the accuracy of the method.

Immune transcriptome analysis of COVID-19 patients infected with SARS-CoV-2 variants carrying the E484K escape mutation identifies a distinct gene module

Fast-spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) energize the COVID-19 pandemic. While viral infections elicit a conserved immune response, it is not known whether SARS-CoV-2 variants, which display enhanced binding to the ACE2 receptor and reduced neutralizing activity by vaccine-elicited antibodies, prompt specific genomic immune responses. To test this, we generated and investigated the transcriptomes in BCs from hospitalized patients infected with either the Alpha variant (n = 36) or with the Alpha variant that had acquired the E484K escape mutation (Alpha+E484K) (n = 13). We identified a gene module preferentially activated in patients infected with the Alpha+E484K variant and in patients infected with the Beta (n = 9) and Gamma (n = 3) variants that also carry by the E484K escape mutation. The E484K signature was enriched for genes preferentially expressed in monocytes and linked to severe viral infection. However, both cohorts had undergone similar treatments and no differences in disease severity were reported suggesting that this signature reflects a variant response and does not necessarily associate with disease outcome. Additionally, longitudinal transcriptome analyses revealed a more persistent retention of immune signatures in Alpha+E484K patients throughout the entire course of COVID-19 disease and convalescence. While the OAS1 Neanderthal mutation has been linked to a milder COVID-19 pathology, we did not identify significant immune transcriptomes differences in the 25 patients homozygous for this mutation. Our study offers insights into distinct molecular immune responses elicited by SARS-CoV-2 variants carrying the E484K escape mutation throughout the COVID-19 disease.

Influence of seed layers on the reflectance of sputtered aluminum thin films

The fabrication of highly reflective aluminum coatings is still an important part of current research due to their high intrinsic reflectivity in a broad spectral range. By using thin seed layers of Cu, CuO_x, Cr, CrO_x, Au, and Ag, the morphology of sputtered (unprotected) aluminum layers and, consequently, their reflectance can be influenced. In this long-term study, the reflectance behavior was measured continuously using spectrophotometry. Particular seed layer materials enhance the reflectance of aluminum coatings significantly and reduce their long-term degradation. Combining such seed layers with evaporation processes and suitable protective layers could further increase the reflectance of aluminum coatings.

Discontinuation versus continuation of renin-angiotensin-system inhibitors in COVID-19 (ACEI-COVID): a prospective, parallel group, randomised, controlled, open-label trial

Background

SARS-CoV-2 entry in human cells depends on angiotensin-converting enzyme 2, which can be upregulated by inhibitors of the renin–angiotensin system (RAS). We aimed to test our hypothesis that discontinuation of chronic treatment with ACE-inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) mitigates the course o\f recent-onset COVID-19.

Methods

ACEI-COVID was a parallel group, randomised, controlled, open-label trial done at 35 centres in Austria and Germany. Patients aged 18 years and older were enrolled if they presented with recent symptomatic SARS-CoV-2 infection and were chronically treated with ACEIs or ARBs. Patients were randomly assigned 1:1 to discontinuation or continuation of RAS inhibition for 30 days. Primary outcome was the maximum sequential organ failure assessment (SOFA) score within 30 days, where death was scored with the maximum achievable SOFA score. Secondary endpoints were area under the death-adjusted SOFA score (AUC_SOFA), mean SOFA score, admission to the intensive care unit, mechanical ventilation, and death. Analyses were done on a modified intention-to-treat basis. This trial is registered with ClinicalTrials.gov, NCT04353596.

Findings

Between April 20, 2020, and Jan 20, 2021, 204 patients (median age 75 years [IQR 66–80], 37% females) were randomly assigned to discontinue (n=104) or continue (n=100) RAS inhibition. Within 30 days, eight (8%) of 104 died in the discontinuation group and 12 (12%) of 100 patients died in the continuation group (p=0·42). There was no significant difference in the primary endpoint between the discontinuation and continuation group (median [IQR] maximum SOFA score 0·00 (0·00–2·00) vs 1·00 (0·00–3·00); p=0·12). Discontinuation was associated with a significantly lower AUC_SOFA (0·00 [0·00–9·25] vs 3·50 [0·00–23·50]; p=0·040), mean SOFA score (0·00 [0·00–0·31] vs 0·12 [0·00–0·78]; p=0·040), and 30-day SOFA score (0·00 [10–90th percentile, 0·00–1·20] vs 0·00 [0·00–24·00]; p=0·023). At 30 days, 11 (11%) in the discontinuation group and 23 (23%) in the continuation group had signs of organ dysfunction (SOFA score ≥1) or were dead (p=0·017). There were no significant differences for mechanical ventilation (10 (10%) vs 8 (8%), p=0·87) and admission to intensive care unit (20 [19%] vs 18 [18%], p=0·96) between the discontinuation and continuation group.

Interpretation

Discontinuation of RAS-inhibition in COVID-19 had no significant effect on the maximum severity of COVID-19 but may lead to a faster and better recovery. The decision to continue or discontinue should be made on an individual basis, considering the risk profile, the indication for RAS inhibition, and the availability of alternative therapies and outpatient monitoring options.

Funding

Austrian Science Fund and German Center for Cardiovascular Research.

Impact of BNT162b First Vaccination on the Immune Transcriptome of Elderly Patients Infected with the B.1.351 SARS-CoV-2 Variant

Fast-spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) energize the COVID-19 pandemic. The B.1.351 variant carrying the escape mutation E484K in the receptor binding domain is of particular concern due to reduced immunological protection following vaccination. Protection can manifest as early as 10 days following immunization with full protection two weeks following the second dose, but the course is not well-characterized for variants. Here, we investigated the immune transcriptome of six elderly individuals (average age 82 yr.) from an old people’s home, who contracted B.1.351, with four having received the first dose of BNT162b eight to 11 days prior to the onset of COVID-19 symptoms. The patients were hospitalized and received dexamethasone treatment. Immune transcriptomes were established from PBMCs approximately 10 and 35 days after the onset of COVID-19 symptomology. RNA-seq revealed a more intensive immune response in vaccinated patients as compared to unvaccinated ones. Specifically, transcription factors linked to the JAK/STAT pathway, interferon stimulated genes, and genes associated with innate antiviral immunity and COVID-19-SARS-CoV-2 infection were highly enriched in vaccinated patients. This rendered the transcriptomes of the older vaccinated group significantly different than older unvaccinated individuals infected at the same institution and more similar to the immune response of younger unvaccinated individuals (ages 48-62) following B.1.351 infection. All individuals in this study whether vaccinated or not were hospitalized due to B.1.351 infection and one vaccinated patient died illustrating that although an enhanced immune response was documented infection it was insufficient to protect from disease. This highlights the need for maintaining physical distancing and prevention measures throughout the time course of vaccination in older adults.

Immune transcriptomes from hospitalized patients infected with the SARS-CoV-2 variants B.1.1.7 and B.1.1.7 carrying the E484K escape mutation

Fast-spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) energize the COVID-19 pandemic. B.1.1.7 (VOC-202012/01) has become the predominant variant in many countries and a new lineage (VOC-202102/02) harboring the E484K escape mutation in the B.1.1.7 background emerged in February 2021 1 . This variant is of concern due to reduced neutralizing activity by vaccine-elicited antibodies 2,3 . However, it is not known whether this single amino acid change leads to an altered immune response. Here, we investigate differences in the immune transcriptome in hospitalized patients infected with either B.1.1.7 (n=28) or B.1.1.7+E484K (n=12). RNA-seq conducted on PBMCs isolated within five days after the onset of COVID symptoms demonstrated elevated activation of specific immune pathways, including JAK-STAT signaling, in B.1.1.7+E484K patients as compared to B.1.1.7. Longitudinal transcriptome studies demonstrated a delayed dampening of interferon-activated pathways in B.1.1.7+E484K patients. Prior vaccination with BNT162b vaccine (n=8 one dose; n=1 two doses) reduced the transcriptome inflammatory response to B.1.1.7+E484K infection relative to unvaccinated patients. Lastly, the immune transcriptome of patients infected with additional variants (B.1.258, B.1.1.163 and B.1.7.7) displayed a reduced activation compared to patients infected with B.1.1.7. Acquisition of the E484K substitution in the B.1.1.7 background elicits an altered immune response, which could impact disease progression.

Impact of BNT162b first vaccination on the immune transcriptome of elderly patients infected with the B.1.351 SARS-CoV-2 variant

Fast-spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) energize the COVID-19 pandemic. The B.1.351 variant carrying the escape mutation E484K in the receptor binding domain is of particular concern due to reduced immunological protection following vaccination. Protection can manifest as early as 10 days following immunization with full protection two weeks following the second dose, but the course is not well-characterized for variants. Here, we investigated the immune transcriptome of six elderly individuals (average age 82 yr.) from an old people's home, who contracted B.1.351, with four having received the first dose of BNT162b eight to 11 days prior to the onset of COVID-19 symptoms. The patients were hospitalized and received dexamethasone treatment. Immune transcriptomes were established from PBMCs approximately 10 and 35 days after the onset of COVID-19 symptomology. RNA-seq revealed a more intensive immune response in vaccinated patients as compared to unvaccinated ones. Specifically, transcription factors linked to the JAK/STAT pathway, interferon stimulated genes, and genes associated with innate antiviral immunity and COVID-19-SARS-CoV-2 infection were highly enriched in vaccinated patients. This rendered the transcriptomes of the older vaccinated group significantly different than older unvaccinated individuals infected at the same institution and more similar to the immune response of younger unvaccinated individuals (age range 48-62) following B.1.351 infection. All individuals in this study whether vaccinated or not were hospitalized due to B.1.351 infection and one vaccinated patient died illustrating that although an enhanced immune response was documented infection it was insufficient to protect from disease. This highlights the need for maintaining physical distancing and prevention measures throughout the time course of vaccination in older adults.

[Elastic, stable intramedullary nailing of pertrochanteric femoral fractures in children (<6-8 years)]

Operationsziel

Minimal-invasive, übungsstabile Versorgung von pertrochantären Femurfrakturen bei Kindern < 6 bis 8 Jahren mittels elastisch-stabiler intramedullärer Nagelung (ESIN).

Indikationen

Proximale, pertrochantäre Femurfrakturen Delbet Typ IV bei Kindern < 6 Jahre.

Kontraindikationen

Trümmerfrakturen, Schenkelhalsfrakturen.

Operationstechnik

Durch Einbringen von insgesamt 3 (gelegentlich nur 2) im proximalen Drittel vorgebogenen, elastischen Titannägeln (TEN) retrograd in das Femur wird im proximalen Fragment eine stabile 3‑Punkt-Abstützung erreicht. Eine weitere Verbesserung der Stabilität kann durch die Applikation von Endcaps erreicht werden.

Weiterbehandlung

Die Nachbehandlung erfolgt mittels Sohlenbelastung während 4 bis 5 Wochen. Röntgenkontrollen erfolgen direkt postoperativ sowie nach 4 bis 5 Wochen. Eine Sportunfähigkeit besteht für 3 Monate.

Ergebnisse

In unserem Patientengut haben wir gute Erfahrungen mit dieser Technik bei den sehr seltenen pertrochantären Frakturen bei Kindern < 6 bis 8 Jahren. Mit minimal-invasivem Vorgehen kann eine übungsstabile Versorgung ohne Notwendigkeit eines Becken-Bein-Gipses erreicht werden.

Immune transcriptomes of highly exposed SARS-CoV-2 asymptomatic seropositive versus seronegative individuals from the Ischgl community

To investigate prevalence of ongoing activation of inflammation following asymptomatic SARS-CoV-2 infection we characterized immune cell transcriptomes from 43 asymptomatic seropositive and 52 highly exposed seronegative individuals with few underlying health issues following a community superspreading event. Four mildly symptomatic seropositive individuals examined three weeks after infection as positive controls demonstrated immunological activation. Approximately four to six weeks following the event, the two asymptomatic groups showed no significant differences. Two seropositive patients with underlying genetic disease impacting immunological activation were included (Cystic Fibrosis (CF), Nuclear factor-kappa B Essential Modulator (NEMO) deficiency). CF, but not NEMO, associated with significant immune transcriptome differences including some associated with severe SARS-CoV-2 infection (IL1B, IL17A, respective receptors). All subjects remained in their usual state of health from event through five-month follow-up. Here, asymptomatic infection resolved without evidence of prolonged immunological activation. Inclusion of subjects with underlying genetic disease illustrated the pathophysiological importance of context on impact of immunological response.

Immune transcriptomes of highly exposed SARS-CoV-2 asymptomatic seropositive versus seronegative individuals from the Ischgl community

To investigate prevalence of ongoing activation of inflammation following asymptomatic SARS-CoV-2 infection we characterized immune cell transcriptomes from 43 asymptomatic seropositive and 52 highly exposed seronegative individuals with few underlying health issues following a community superspreading event. Four mildly symptomatic seropositive individuals examined three weeks after infection as positive controls demonstrated immunological activation. Approximately four to six weeks following the event, the two asymptomatic groups showed no significant differences. Two seropositive patients with underlying genetic disease impacting immunological activation were included (Cystic Fibrosis (CF), Nuclear factor-kappa B Essential Modulator (NEMO) deficiency). CF, but not NEMO, associated with significant immune transcriptome differences including some associated with severe SARS-CoV-2 infection (IL1B, IL17A, respective receptors). All subjects remained in their usual state of health from event through five-month follow-up. Here, asymptomatic infection resolved without evidence of prolonged immunological activation. Inclusion of subjects with underlying genetic disease illustrated the pathophysiological importance of context on impact of immunological response.

Investigation of SiO2-Al2O3 nanolaminates for protection of silver reflectors

H₂S and particles from the atmosphere can damage silver reflectors. These defects lead to scattering and a reduction of reflectivity. With regard to these risks, the suitability of sputtered SiO₂, Al₂O₃, and SiO₂-Al₂O₃ nanolaminates for the protection of Ag was analyzed. The optical properties, protection properties against H₂S, solubility, film stress, and protection properties against particle-induced defect formation have been investigated. Especially in the case of particle-induced defects on protected Ag, differences between the protective coatings are considerable, and the nanolaminate layers have advantageous properties.

Investigation of the refractive index repeatability for tantalum pentoxide coatings, prepared by physical vapor film deposition techniques

Random effects in the repeatability of refractive index and absorption edge position of tantalum pentoxide layers prepared by plasma-ion-assisted electron-beam evaporation, ion beam sputtering, and magnetron sputtering are investigated and quantified. Standard deviations in refractive index between 4*10^-4 and 4*10^-3 have been obtained. Here, lowest standard deviations in refractive index close to our detection threshold could be achieved by both ion beam sputtering and plasma-ion-assisted deposition. In relation to the corresponding mean values, the standard deviations in band-edge position and refractive index are of similar order.

Description of particle induced damage on protected silver coatings

In the visible to infrared spectral range, highly-reflective silver mirrors are applied in the manufacture of optical instruments such as telescopes. However, it is still difficult to combine high reflectivity and long-term stability of the protected silver coating. We show that the deposition of impervious protective layers is necessary but often not sufficient for long-term environmental stability. Hygroscopic air borne particles absorbed by the protections surface attract water molecules and form a solution. This solution first damages the protection, subsequently permeates the protection and finally damages the silver whereby the reflectivity is reduced. We demonstrate this particular damage mechanism with different experiments and describe this mechanism in detail.

Estimation of the composition of coelectron-beam-evaporated thin-mixture films by making use of the Wiener bounds

Material mixtures offer prospective possibilities for synthesizing coating materials with tailored optical constants. We present experimental results for mixture coatings of alumina/aluminum fluoride and alumina/hafnia deposited by electron beam evaporation. Thereby, the volume filling factors of the components are commonly estimated on the basis of deposition rates measured by quartz crystal microbalance. The interplay between the vapor fluxes from the two evaporation sources, the crosstalk between quartz crystal microbalances, and the influence of the plasma source on the tooling factors limit the accuracy of this estimation, and this has motivated us to develop an alternative approach. The general idea of our approach is based on the commonly high accuracy in thin-film optical constant determination using spectrophotometry. Therefore, these optical constants serve as a reliable input for a rather simple but robust evaluation procedure based on the concept of Wiener bounds. The consistency of the obtained results is illustrated by opposing the data to the elementary film composition estimated from energy-dispersive x-ray spectroscopy.

Stellar dynamics. The fastest unbound star in our Galaxy ejected by a thermonuclear supernova

Hypervelocity stars (HVSs) travel with velocities so high that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a spectroscopic and kinematic analysis of US 708. Traveling with a velocity of ~1200 kilometers per second, it is the fastest unbound star in our Galaxy. In reconstructing its trajectory, the Galactic center becomes very unlikely as an origin, which is hardly consistent with the most favored ejection mechanism for the other HVSs. Furthermore, we detected that US 708 is a fast rotator. According to our binary evolution model, it was spun-up by tidal interaction in a close binary and is likely to be the ejected donor remnant of a thermonuclear supernova.

La/B(4)C multilayer mirrors with an additional wavelength suppression

In this paper, the authors report on La/B(4)C multilayer mirrors designed for an incidence angle of 45° with both maximum reflectivity at a wavelength of 6.7 nm and reflectivity suppression at a wavelength of 20.1 nm. These mirrors were deposited for the EIS-TIMER at the FERMI@Elettra Free Electron Laser. The multilayer structure and optical properties were characterized using grazing incidence X-ray reflectometry with Cu-K(α) radiation and EUV reflectometry in the spectral region of 6.5 - 21.0 nm. An anti-reflective coating designed at the wavelength of 20.1 nm had to be deposited on top of the high reflective La/B(4)C multilayer mirror optimized at a wavelength of 6.7 nm. Measured reflectivities of 53.4% at the wavelength of 6.72 nm and 0.15% at the wavelength of 20.1 nm were simultaneously achieved. It is shown that the reflectivity loss at the wavelength of 6.7 nm due to the utilization of antireflective coating designed at the wavelength of 20.1 nm can be minimized up to 1.0%.

Protected and enhanced aluminum mirrors for the VUV

Aluminum layers protected with fluoride coatings have been deposited by evaporation and characterized with respect to their suitability as vacuum ultraviolet (VUV) mirrors. Optical characterization has been performed by spectrophotometry, while the surface quality of the layers has been judged by means of x ray reflection, scanning electron microscopy, and atomic force microscopy. In particular, protection with aluminum fluoride results in superior VUV reflection properties. VUV reflectance values between 80% and nearly 90% have been verified even two years after deposition and exposure to the atmosphere.

Manufacture and characterization of optical coatings with incorporated copper island films

Copper island films have been prepared by thermal evaporation in vacuum and characterized by in situ as well as ex situ spectrophotometry. The parallel investigation of the island morphology by means of transmission electron microscopy allowed us to establish a clear correlation between film structure and optical properties. The effective optical constants of the copper island films could be determined by means of a fit of their ex situ transmission and reflection spectra. The effective optical constants have been used for designing and preparing optical multilayer coatings applicable for attenuator or color filter specifications. Measured characteristics of the multilayer coatings are in very good agreement with the calculated spectra.

Improved scratch resistance for antireflective coatings on sapphire

Antireflective coatings on sapphire were optimized by variation of the coating design, the total thickness, and the highly refractive material used. The coatings were characterized with a focus on their scratch resistance. An increased resistance against scratching wear is shown for hafnia-containing coatings with a total thickness of about 500 nm.

Plasma-etched organic layers for antireflection purposes

Organic layers can be used to realize special functions in optical interference coatings. Suitable compounds for such layers were thermally evaporated and characterized. A plasma etching procedure was applied to produce nanostructures on top of the organic layers to reduce their effective refractive indices. Broadband antireflective coatings were obtained by combining these artificial low-index layers with conventionally prepared interference stacks.

Plasma-assisted deposition of metal fluoride coatings and modeling the extinction coefficient of as-deposited single layers

We realized metal fluoride coatings with a high packing density and a low extinction coefficient by plasma (ion)-assisted deposition. The densification can be performed by different types of plasma sources, e.g., by a Leybold LION source and a Leybold APSpro, respectively. But the as-deposited coatings show a characteristic absorption behavior, whereas the absorption losses can be reduced in a postdeposition UV treatment step. We show experimental results of the plasma-assisted metal fluorides before and after the UV treatment and present a new model that allows us to describe and calculate the characteristic absorption losses of LaF3, MgF2, and AlF3.

Combined in situ and ex situ optical data analysis of magnesium fluoride coatings deposited by plasma ion assisted deposition

The combination of in situ spectrophotometry during film deposition and ex situ spectrophotometry allows insight into the depth distribution of optical losses in plasma ion assisted deposition coatings. An adapted optical characterization strategy for absorbing coatings using only in situ transmittance data has been developed and is exemplified in application to magnesium fluoride coatings. Measurements and simulation results strongly indicate an increased absorption caused by local understoichiometry of the fluoride material close to the fused silica substrate.

Mixed oxide coatings for optics

Material mixtures offer new possibilities for synthesizing coating materials with tailored optical and mechanical properties. We present experimental results on mixtures of HfO2, ZrO2, and Al2O3, pursuing applications in UV coating technology, while the mixtures are prepared by magnetron sputtering, ion beam sputtering, plasma ion-assisted deposition (PIAD), and electron beam evaporation without assistance. The properties investigated include the refractive index, optical gap, thermal shift, and mechanical stress. The first high reflectors for UV applications have been deposited by PIAD.

Impact of emotion on cognition in trauma survivors: what is the role of posttraumatic stress disorder?

BACKGROUND

Cognitive theories of anxiety disorders postulate an increased attentional bias to environmental cues associated with threat that underlies the exaggerated fear response. The role of trauma, which may represent strong competitive advantage for attention, remains unclear. We investigated the influence of trauma exposure and the presence of anxiety/stress disorders on the impact of emotional distractors on cognitive performance.

METHODS

Fourteen trauma-exposed subjects with PTSD, 12 trauma-exposed subjects with anxiety disorders other than PTSD, 12 trauma-exposed healthy subjects and 19 non-trauma-exposed healthy controls participated in this study. The impact of emotion on cognition was determined by the Affective Stroop task that measures the effect of irrelevant emotional distractors on the speed of operant responding.

RESULTS

The speed of cognitive performance was significantly reduced in the presence of negative distractors versus neutral or positive distractors in subjects with PTSD, while there was no significant influence of the distractor type on performance in the other diagnostic groups (diagnosis-by-distractor type interaction, p<0.001). While negative distractors induced the same levels of anxiety and depersonalization in subjects with PTSD and subjects with other anxiety disorders, distractor-induced depersonalization was associated with slowing of cognitive performance in PTSD (p=0.02) but not in other groups.

LIMITATIONS

Different types of anxiety disorders in the non-PTSD group might reduce the selectivity of the results; some subjects received medication possibly impacting on their cognitive functioning.

CONCLUSIONS

The cognitive impairments in the presence of negative distractors specifically found in PTSD call for research into novel psychotherapeutic approaches, e.g. attentional training, for PTSD.

Glucose regulation of β-cell stress in type 2 diabetes

In type 2 diabetes, the β-cell is exposed to chronic hyperglycaemia, which increases its metabolic activity, with excess generation of reactive oxygen species (ROS) as a consequence. ROS accumulation induces both oxidative and endoplasmic reticulum (ER) stress, which may lead to β-cell dysfunction and apoptosis. Recent data suggest that oxidative and ER stress are interconnected, although the mechanisms involved in nutrient regulation of the different stress pathways are dissimilar. Several components of the oxidative and ER stress machineries have important roles in the physiological response to glucose and are thus necessary for normal β-cell function. Glucose stimulates signalling pathways that provide crucial messages for β-cell adaptation to metabolic stress; however, the same pathways may eventually lead to apoptosis. Dynamic, temporally fluctuating activation of stress signalling is probably required for the maintenance of β-cell survival, whereas its persistent activation results in β-cell dysfunction and apoptosis. Thus, stress signalling is a 'double-edged sword' that may promote adaptation or apoptosis according to the balance between the divergent outputs of the various pathways. Developing new strategies for β-cell protection based on inhibition of oxidative and/or ER stress requires comprehensive understanding of the switch from β-cell adaptation to β-cell apoptosis under conditions of metabolic stress, such as occurs under hyperglycaemic conditions.

Neuronal nitric oxide synthase protects the pancreatic beta cell from glucolipotoxicity-induced endoplasmic reticulum stress and apoptosis

AIMS/HYPOTHESIS

Cytokines stimulate nitric oxide production in pancreatic beta cells, leading to endoplasmic reticulum (ER) stress and apoptosis. Treatment of beta cells with glucose and NEFA induces nitric oxide synthase (NOS) as well as ER stress. However, the role of NO in glucolipotoxicity-induced ER stress in beta cells is not clear.

METHODS

We studied the effect of high glucose and palmitate levels on NOS isoform production in rat and Psammomys obesus islets and in insulinoma-1E beta cells. The effects of neuronal NOS (nNOS) inhibition by small interfering RNA or by N (omega)-nitro-L-arginine methyl ester (L-NAME) on beta cell function, ER stress and apoptosis under conditions of glucolipotoxicity were investigated.

RESULTS

Overnight incubation of rat and P. obesus islets at 22.2 mmol/l glucose with 0.5 mmol/l palmitate induced the production of nNOS but not inducible NOS (iNOS), in contrast with the robust stimulation of iNOS by cytokines. NOS inhibition by L-NAME did not prevent the decrease in glucose-stimulated insulin secretion and proinsulin biosynthesis or the depletion of islet insulin content observed under conditions of glucolipotoxicity. Moreover, treatment of beta cells with palmitate and L-NAME together resulted in marked activation of the IRE1alpha and PERK pathways of the unfolded protein response. This was associated with increased JNK phosphorylation and apoptosis in islets and beta cells. Moreover, partial nNos knockdown increased JNK phosphorylation and CHOP production, leading to apoptosis.

CONCLUSIONS/INTERPRETATION

In beta cells subjected to glucolipotoxic conditions, chronic inhibition of NOS exacerbates ER stress and activates JNK. Therefore, induction of nNOS is an adaptive response to glucolipotoxicity that protects beta cells from stress and apoptosis.

All-oxide broadband antireflection coatings by plasma ion assisted deposition: design, simulation, manufacturing and re-optimization

A new all-oxide design for broadband antireflection coatings with significantly reduced impact of deposition errors to the final reflectance is presented. Computational manufacturing including re-optimization during deposition has been used in the design work to account for maximum insensibility of the design with respect to deposition errors typical for plasma ion assisted deposition PIAD. Repeated deposition runs with the deducted monitoring and re-optimization strategy verify the validity of the simulations and the stability of the derived design solution.

Computational manufacturing of optical interference coatings: method, simulation results, and comparison with experiment

Virtual deposition runs have been performed to estimate the production yield of selected oxide optical interference coatings when plasma ion-assisted deposition with an advanced plasma source is applied. Thereby, deposition of each layer can be terminated either by broadband optical monitoring or quartz crystal monitoring. Numerous deposition runs of single-layer coatings have been performed to investigate the reproducibility of coating properties and to quantify deposition errors for the simulation. Variations of the following parameters are considered in the simulation: refractive index, extinction coefficient, and film thickness. The refractive index and the extinction coefficient are simulated in terms of the oscillator model. The parameters are varied using an apodized normal distribution with known mean value and standard deviation. Simulation of variations in the film thickness is performed specific to the selected monitoring strategy. Several deposition runs of the selected oxide interference coatings have been performed to verify the simulation results by experimental data.

Onset of the optical damage in CaF(2) optics caused by deep-UV lasers

The exterior sides of calcium fluoride (CaF(2)) outcoupling mirrors are damaged by ArF laser light irradiation with high pulse-energy densities (80 mJ/cm(2)). The damage is generated by a partial alteration of the CaF(2) substrate to calcite. The CaF(2) decomposition is driven by photochemical processes due to the UV light and the presence of water vapor and is supported by elevated temperatures within the laser beam transmitting area. Small filaments act as starting points for the decomposition process, where kerogenous carbon and calcite can occur.

Balancing needs and means: the dilemma of the beta-cell in the modern world

The insulin resistance of type 2 diabetes mellitus (T2DM), although important for its pathophysiology, is not sufficient to establish the disease unless major deficiency of beta-cell function coexists. This is demonstrated by the fact that near-physiological administration of insulin (CSII) achieved excellent blood glucose control with doses similar to those used in insulin-deficient type 1 diabetics. The normal beta-cell adapts well to the demands of insulin resistance. Also in hyperglycaemic states some degree of adaptation does exist and helps limit the severity of disease. We demonstrate here that the mammalian target of rapamycin (mTOR) system might play an important role in this adaptation, because blocking mTORC1 (complex 1) by rapamycin in the nutritional diabetes model Psammomys obesus caused severe impairment of beta-cell function, increased beta-cell apoptosis and progression of diabetes. On the other hand, under exposure to high glucose and FFA (gluco-lipotoxicity), blocking mTORC1 in vitro reduced endoplasmic reticulum (ER) stress and beta-cell death. Thus, according to the conditions of stress, mTOR may have beneficial or deleterious effects on the beta-cell. beta-Cell function in man can be reduced without T2DM/impaired glucose tolerance (IGT). Prospective studies have shown subjects with reduced insulin response to present, several decades later, an increased incidence of IGT/T2DM. From these and other studies we conclude that T2DM develops on the grounds of beta-cells whose adaptation capacity to increased nutrient intake and/or insulin resistance is in the lower end of the normal variation. Inborn and acquired factors that limit beta-cell function are diabetogenic only in a nutritional/metabolic environment that requires high functional capabilities from the beta-cell.

Insulin counteracts glucotoxic effects by suppressing thioredoxin-interacting protein production in INS-1E beta cells and in Psammomys obesus pancreatic islets

AIMS/HYPOTHESIS

In type 2 diabetes, glucose toxicity leads to beta cell apoptosis with decreased beta cell mass as a consequence. Thioredoxin-interacting protein (TXNIP) is a critical mediator of glucose-induced beta cell apoptosis. Since hyperglycaemia leads to elevated serum insulin, we hypothesised that insulin is involved in the regulation of TXNIP protein levels in beta cells.

METHODS

We studied the production of TXNIP in INS-1E beta cells and in islets of Psammomys obesus, an animal model of type 2 diabetes, in response to glucose and different modulators of insulin secretion.

RESULTS

TXNIP production was markedly augmented in islets from diabetic P. obesus and in beta cells exposed to high glucose concentration. In contrast, adding insulin to the culture medium or stimulating insulin secretion with different secretagogues suppressed TXNIP. Inhibition of glucose and fatty acid-stimulated insulin secretion with diazoxide increased TXNIP production in beta cells. Nitric oxide (NO), a repressor of TXNIP, enhanced insulin signal transduction, whereas inhibition of NO synthase abolished its activation, suggesting that TXNIP inhibition by NO is mediated by stimulation of insulin signalling. Treatment of beta cells chronically exposed to high glucose with insulin reduced beta cell apoptosis. Txnip knockdown mimicking the effect of insulin prevented glucose-induced beta cell apoptosis.

CONCLUSIONS/INTERPRETATION

Insulin is a potent repressor of TXNIP, operating a negative feedback loop that restrains the stimulation of TXNIP by chronic hyperglycaemia. Repression of TXNIP by insulin is probably an important compensatory mechanism protecting beta cells from oxidative damage and apoptosis in type 2 diabetes.

Extreme-ultraviolet-induced oxidation of Mo/Si multilayers

The extreme-ultraviolet (EUV)-induced oxidation of Mo/Si multilayer mirrors was characterized by several methods: EUV reflectivity, x-ray photoelectron spectroscopy, small-angle x-ray reflectometry, atomic force microscopy, and EUV scattering measurements. Based on the results of the different investigation techniques, an oxidation model was developed to explain the degradation of the mirrors under EUV radiation.

Stochastic subwavelength structures on poly(methyl methacrylate) surfaces for antireflection generated by plasma treatment

Subwavelength structures of sufficient height-to-width aspect ratio are adequate for reduction of the Fresnel reflection of surfaces. In the case of low-pressure plasma-treated polymers, the self-organized features are stochastically distributed on the surface area with unequal shapes. Common descriptions use effective medium theory along with a continuously altering volume filling factor that together lead to a lateral homogeneous layer with a depth-dependent refractive index. We use a fixed gradient function for the refractive index for reverse engineering of in situ measured broadband optical data, and we compare the results with nonoptic methods.