Radiocarbon positive-ion mass spectrometry

Proof-of-principle of a new mass spectrometric technique for radiocarbon measurement is demonstrated. Interfering nitrogen and hydrocarbon molecules are largely eliminated in a charge-exchange cell operating on non-metallic gas. The positive-to-negative ion conversion is the reverse of that conventionally used in accelerator mass spectrometry (AMS) and is compatible with plasma ion sources that may be significantly more efficient and capable of greater output than are AMS sputter ion sources. The Nanogan electron cyclotron resonance (ECR) ion source employed exhibited no sample memory and the >50 kyrs age range of AMS was reproduced. A bespoke prototype new instrument is now required to optimise the plasma and cell physics and to realise hypothetical performance gains over AMS

Rear optical reflection and passivation using a nanopatterned metal/dielectric structure in thin-film solar cells

Currently, one of the main limitations in ultrathin Cu(In,Ga)Se2 (CIGS) solar cells are the optical losses, since the absorber layer is thinner than the light optical path. Hence, light management, including rear optical reflection and light trapping is needed. In this work we focus on increasing the rear optical reflection. For this, a novel structure based on having a metal interlayer in between the Mo rear contact and the rear passivation layer is presented. In total, eight different metallic interlayers are compared. For the whole series, the passivation layer is aluminum oxide (Al2O3). The interlayers are used to enhance the reflectivity of the rear contact and thereby increasing the amount of light reflected back into the absorber. In order to understand the effects of the interlayer in the solar cell performance both from optical and/or electrical point of view, optical simulations were performed together with fabrication and electrical measurements. Optical simulations results are compared with current density-voltage (J-V) behavior and external quantum efficiency (EQE) measurements. A detailed comparison between all the interlayers is done, in order to identify the material with the greatest potential to be used as rear reflective layer for ultrathin CIGS solar cells and to establish fabrication challenges. The Ti-W alloy is a promising rear reflective layer since it provides solar cells with light to power conversion efficiency values of 9.9 %, which is 2.2 % (abs) higher than the passivated ultrathin sample and 3.7 % (abs) higher than the unpassivated ultrathin reference sample.publishe

Search for the best indicators for the presence of a VPS13B gene mutation and confirmation of diagnostic criteria in a series of 34 patients genotyped for suspected Cohen syndrome

BACKGROUND: Cohen syndrome is a rare autosomal recessive inherited disorder that results from mutations of the VPS13B gene. Clinical features consist of a combination of mental retardation, facial dysmorphism, postnatal microcephaly, truncal obesity, slender extremities, joint hyperextensibility, myopia, progressive chorioretinal dystrophy, and intermittent neutropenia.PATIENTS AND METHODS: The aim of the study was to determine which of the above clinical features were the best indicators for the presence of VPS13B gene mutations in a series of 34 patients with suspected Cohen syndrome referred for molecular analysis of VPS13B. RESULTS: 14 VPS13B gene mutations were identified in 12 patients, and no mutation was found in 22 patients. The presence of chorioretinal dystrophy (92% vs 32%, p=0.0023), intermittent neutropenia (92% vs 5%, p<0.001), and postnatal microcephaly (100% vs 48%, p=0.0045) was significantly higher in the group of patients with a VPS13B gene mutation compared to the group of patients without a mutation. All patients with VPS13B mutations had chorioretinal dystrophy and/or intermittent neutropenia. The Kolehmainen diagnostic criteria provided 100% sensibility and 77% specificity when applied to this series. CONCLUSION: From this study and a review of more than 160 genotyped cases from the literature, it is concluded that, given the large size of the gene, VPS13B screening is not indicated in the absence of chorioretinal dystrophy or neutropenia in patients aged over 5 years. The follow-up of young patients could be a satisfactory alternative unless there are some reproductive issues

Imaging Immune Surveillance of Individual Natural Killer Cells Confined in Microwell Arrays

New markers are constantly emerging that identify smaller and smaller subpopulations of immune cells. However, there is a growing awareness that even within very small populations, there is a marked functional heterogeneity and that measurements at the population level only gives an average estimate of the behaviour of that pool of cells. New techniques to analyze single immune cells over time are needed to overcome this limitation. For that purpose, we have designed and evaluated microwell array systems made from two materials, polydimethylsiloxane (PDMS) and silicon, for high-resolution imaging of individual natural killer (NK) cell responses. Both materials were suitable for short-term studies (<4 hours) but only silicon wells allowed long-term studies (several days). Time-lapse imaging of NK cell cytotoxicity in these microwell arrays revealed that roughly 30% of the target cells died much more rapidly than the rest upon NK cell encounter. This unexpected heterogeneity may reflect either separate mechanisms of killing or different killing efficiency by individual NK cells. Furthermore, we show that high-resolution imaging of inhibitory synapse formation, defined by clustering of MHC class I at the interface between NK and target cells, is possible in these microwells. We conclude that live cell imaging of NK-target cell interactions in multi-well microstructures are possible. The technique enables novel types of assays and allow data collection at a level of resolution not previously obtained. Furthermore, due to the large number of wells that can be simultaneously imaged, new statistical information is obtained that will lead to a better understanding of the function and regulation of the immune system at the single cell level

L'indemnisation des servitudes d'urbanisme.

Moor Pierre, Donzel Valérie. Suisse : L'indemnisation des servitudes d'urbanisme. In: Droit et Ville, tome 48, 1999. Colloque international : L'indemnisation des servitudes d'urbanisme en Europe (Toulouse, 15-16 octobre 1999). Première partie : Rapports internationaux. pp. 283-315

Effect of foodstuffs on the absorption of zinc sulfate

Single doses of zinc sulfate were given to healthy young volunteers, either in the fasting state or with various types of meals. Dairy products (milk and cheese) and brown bread decreased zinc absorption, as indicated by a significant drop in peak serum zinc levels. Zinc absorption was decreased when zinc was given in the fasting state with the same amounts of purified phosphate or phytate as those found in foods above. Experiments in vitro have shown that zinc is precipitated by phosphate and phytate at pH values close to that of the intestinal lumen. Coffee also seems to inhibit zinc absorption

License (CC BY 4.0) Radiocarbon positive-ion mass spectrometry

a b s t r a c t Proof-of-principle of a new mass spectrometric technique for radiocarbon measurement is demonstrated. Interfering nitrogen and hydrocarbon molecules are largely eliminated in a charge-exchange cell operating on non-metallic gas. The positive-to-negative ion conversion is the reverse of that conventionally used in accelerator mass spectrometry (AMS) and is compatible with plasma ion sources that may be significantly more efficient and capable of greater output than are AMS sputter ion sources. The Nanogan electron cyclotron resonance (ECR) ion source employed exhibited no sample memory and the &gt;50 kyrs age range of AMS was reproduced. A bespoke prototype new instrument is now required to optimise the plasma and cell physics and to realise hypothetical performance gains over AMS

The effectiveness of adapted schema therapy for cluster C personality disorders in older adults: Integrating positive schemas

Introduction Schema therapy (ST) is an efficacious psychotherapy for personality disorders (PDs) in adults. The first empirical support for the effectiveness of ST in older adults with cluster C PDs was provided recently. ST partly focusses on the positive, but there is an increasing awareness of imbalance in the ST community because of the emphasis on negative schemas versus attention to positive schemas. Positive schemas may be important vehicles of therapeutic change in psychotherapy with older people, as it may help strengthen the healthy adult mode, and it might also help change a negative life review. Suggestions were made to increase the efficacy and feasibility of ST in older adults, including adjusting the case conceptualisation, modifying the experiential techniques, making use of the patient's wisdom and reactivating positive schemas. The aim of the current study is to investigate the feasibility and effectiveness of adapted individual ST for older adults. Methods/design A multiple baseline design is used with positive and negative core beliefs as primary outcome measures. Ten older adults (age > 60 years) with cluster C PDs are treated with schema therapy, with weekly sessions during one year. This treatment phase is preceded by a baseline phase varying randomly from 4 to 8 weeks. After treatment, there is a 6-month follow-up phase with monthly booster sessions. Symptomatic distress, schema modes, early maladaptive schemas (EMS) and early adaptive schemas (EAS) are secondary outcome measures. PD will be diagnosed before baseline and after treatment phase. EAS are assessed with the Dutch version of the Young Positive Schema Questionnaire (YPSQ). Discussion To the best of our knowledge, this is the first empirical study in which positive schemas are integrated in ST treatment to examine the efficacy of an adapted form of ST for older adults. This is in line with wider developments supporting the integration of positive schema's into ST. It offers the possibility to improve the effectiveness of ST in older adults