Manipulating etch selectivities in XeF2 vapour etching

The vapour etching of silicon sacrificial layers is often a critical process in the fabrication of micro/nanosystems. This method has a number of attractive features, in particular, high etch rates of sacrificial silicon layers and good selectivities associated with photoresist, SiO₂, stoichiometric Si₃N₄ and a number of regularly used metal films. However, materials that are commonly inert to XeF₂ are etched when located in the proximity of a silicon sacrificial layer. This proximity is a common situation in the fabrication of such systems and can become a critical issue affecting process control and device reliability. This work uses test structures that have been designed to be very sensitive, thereby delivering much lower selectivities then are typically reported in the literature. This sensitive quantification of the proximity effect is used to evaluate methods designed to improve the selectivity. This work suggests that a reduction in the processing temperature from 25°C to 10°C increases the Si: PECVD SiN selectivity by 68%. However, a more easily implemented modification is to flow hydrogen into the reaction chamber. This method improves the Si: PECVD SiN selectivity by an order of magnitude and the Si: LPCVD SiN selectivity between 200% and 600%. [2020-0346]

Functional IP3- and ryanodine-sensitive calcium stores in presynaptic varicosities of NG108–15 (rodent neuroblastoma × glioma hybrid) cells

Presynaptic varicosities of the model neuronal cell line NG108–15, a cholinergic neuroblastoma cell × glioma cell hybrid capable of innervating striated myotubes, were examined for the presence of inositol 1,4,5-trisphosphate (IP3)-sensitive and Ca2+-activated (ryanodine-sensitive) Ca2+ stores using confocal microscopic imaging of Ca2+-sensitive fluorescent dye loaded into the cells.Initial demonstration of the presence of IP3 receptors and ryanodine receptors in the NG108–15 varicosities was obtained using immunocytochemistry.Treatment of NG108–15 cells with bradykinin (0.1 μM), whose receptor is linked to IP3 generation, and separately, caffeine (10 mM), an activator of endoplasmic reticulum ryanodine receptors, resulted in substantial increases in [Ca2+]i in the varicosities.K+-evoked changes in [Ca2+]i in the varicosities were reduced (52 %) after emptying the ryanodine-sensitive Ca2+ store using caffeine (10 mM), but were not affected by prior depletion of the IP3-sensitive Ca2+ store using thapsigargin (1 μM).Bradykinin-induced changes in [Ca2+]i were abolished following depletion of the IP3-sensitive Ca2+ store using thapsigargin (1 μM) and were reduced (72 %) by prior emptying of the ryanodine-sensitive Ca2+ store with caffeine (10 mM).The same results were obtained when the varicosities of the NG108–15 cells had formed synaptic junctions with co-cultured rat hindlimb myotubes.Taken together, the results suggest that, in the varicosities, activation of the IP3 pathway evoked the release of Ca2+ from the IP3-sensitive store, which, in turn, secondarily induced the release of Ca2+ from the ryanodine-sensitive store via Ca2+-induced Ca2+ release, and that depolarization-induced Ca2+ entry evoked Ca2+-induced Ca2+ release only from the ryanodine-sensitive store. Thus, functional internal Ca2+ stores are inherent components of presynaptic varicosities in this neural cell line

Local innovation ecosystem: structure and impact on adaptive capacity of firms

International audienceFocusing on the Local Innovation Ecosystem in Hauts-de-France region (France), the aim of this paper is to analyse how the ecosystems affect firm’s adaptive capacity. First, we show these local innovation ecosystems are based on Innovation Parks. They promote knowledge development and innovation processes by bringing together heterogeneous agents such as research laboratories, technological structures, finance organisations, brokers, start-ups, and companies within a complex interacting and strategic context. Second, we use econometric models to test the impact of these local innovation ecosystems on the innovativeness and technological diversity of firms viewed as components of adaptive capacity. Our results show that firms belonging to local innovation ecosystems centred on innovation parks are both more innovative and more technologically diversified than others. Our study suggests further empirical research in order to specify links between the most relevant characteristics of the innovation ecosystem and the firm’s adaptive capacity

The NANOTUMOR consortium - Towards the Tumor Cell Atlas

International audienceCancer is a multi-step disease where an initial tumour progresses through critical steps shaping, in most cases, life-threatening secondary foci called metastases. The oncogenic cascade involves genetic, epigenetic, signalling pathways, intracellular trafficking and/or metabolic alterations within cancer cells. In addition, pre-malignant and malignant cells orchestrate complex and dynamic interactions with non-malignant cells and acellular matricial components or secreted factors within the tumour microenvironment that is instrumental in the progression of the disease. As our aptitude to effectively treat cancer mostly depends on our ability to decipher, properly diagnose and impede cancer progression and metastasis formation, full characterisation of molecular complexes and cellular processes at play along the metastasis cascade is crucial. For many years, the scientific community lacked adapted imaging and molecular technologies to accurately dissect, at the highest resolution possible, tumour and stromal cells behaviour within their natural microenvironment. In that context, the NANOTUMOR consortium is a French national multi-disciplinary workforce which aims at a providing a multi-scale characterisation of the oncogenic cascade, from the atomic level to the dynamic organisation of the cell in response to genetic mutations, environmental changes or epigenetic modifications. Ultimately, this program aims at identifying new therapeutic targets using innovative drug design

R&D productivity and the organization of cluster policy: an empirical evaluation of the Industrial Cluster Project in Japan

Industrial cluster, University-industry partnership, Small and medium enterprise, R&D, Patent, O23, O32, O38, R38,