241 research outputs found

    Effect of nanostructuration on compressibility of cubic BN

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    Compressibility of high-purity nanostructured cBN has been studied under quasi-hydrostatic conditions at 300 K up to 35 GPa using diamond anvil cell and angle-dispersive synchrotron powder X-ray diffraction. It has been found that the data fit to the Vinet equation of state yields the values of the bulk modulus B₀ of 375(4) GPa with its first pressure derivative B₀´ of 2.3(3), thus, the nanometer grain size (≈ 20 nm) results in a decrease of the bulk modulus by ≈ 9‰.Сжимаемость высокочистого наноструктурированного cBN была изучена в квазигидростатических условиях при 300 K до 35 GPa в алмазных наковальнях с помощью угловой дисперсионной рентгеновской дифракции синхротронного излучения. Описание полученных данных уравнением состояния Винэ дает значение модуля сжимаемости B₀ = 375(4) ГПа и его первой производной по давлению B₀' = 2.3(3). Наноразмер зерна (~ 20 нм) приводит к уменьшению модуля сжимаемости на ~ 9 %.Стисливість високочистого наноструктурованого cBN була вивчена в квазігідростатичних умовах при 300 K до 35 ГПa в алмазних наковальнях за допомогою кутової дисперсійної рентгенівської дифракції синхротронного випромінювання. Опис одержаних даних рівнянням стану Віне дає значення модуля стисливості B₀ = 375(4) ГПа і його першої похідної по тиску B₀' = 2.3(3). Нанорозмір зерна (~ 20 нм) приводить до зменшення модуля стисливості на ~ 9 %

    Equation of state of single-crystal cubic boron phosphide

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    The 300 K equation of state of cubic (zinc-blende) boron phosphide BP has been studied by in situ single-crystal X-ray diffraction with synchrotron radiation up to 55 GPa. The measurements have been performed under quasi-hydrostatic conditions using a Ne pressure medium in a diamond anvil cell. A fit of the experimental p-V data to the Vinet equation of state yields the bulk modulus B0 of 179(1) GPa with its pressure derivative of 3.3(1). These values are in a good agreement with previous elastic measurements, as well as with semiempirical estimations.Уравнение состояния кубического (цинковая обманка) фосфида бора BP при 300 К изучено in situ до давления 55 ГПа с применением монокристаллической дифракции рентгеновских лучей с синхротронным излучением. Измерения проводили в алмазных наковальнях в квазигидростатических условиях с использованием Ne в качестве среды, передающей давление. Соответствие экспериментальных p-V данных уравнению состояния Винета (Vinet) дает объемный модуль упругости B0 = 179(1) ГПа и его производную по давлению 3,3(1). Эти величины хорошо согласуются с прежними измерениями упругости, а также с полуэмпирическими оценками.Рівняння стану кубічного (цинкова обманка) фосфіду бору BP при 300 К вивчено in situ до тиску 55 ГПа зі застосуванням монокристалічної дифракції рентгенівських променів із синхротронним випромінюванням. Вимірювання проводили в алмазних ковадлах у квазігідростатичних умовах з використанням Ne в якості середовища, що передає тиск. Відповідність експериментальних p-V даних рівнянню стану Вінета (Vinet) дає об’ємний модуль пружності B0 = 179(1) ГПа і його похідну по тиску 3,3(1). Ці величини добре узгоджуються з попередніми вимірюваннями пружності, а також із напівемпіричними оцінками

    Measures of Performance and Proficiency in Robotic-Assisted Surgery : A Systematic Review

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    The first author received a research grant from RCS England and Health Education England in November 2021 until present to complete the study.Peer reviewedPostprin

    Effect of nanostructuration on compressibility of cubic BN

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    Compressibility of high-purity nanostructured cBN has been studied under quasi-hydrostatic conditions at 300 K up to 35 GPa using diamond anvil cell and angle-dispersive synchrotron X-ray powder diffraction. A data fit to the Vinet equation of state yields the values of the bulk modulus B0 of 375(4) GPa with its first pressure derivative B0' of 2.3(3). The nanometer grain size (\sim20 nm) results in decrease of the bulk modulus by ~9%

    Impact of deficit irrigation on grapevine cv. ‘Touriga Nacional’ during three seasons in Douro region: an agronomical and metabolomics approach

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    The introduction of irrigation in vineyards of the Mediterranean basin is a matter of debate, in particular in those of the Douro Demarcated Region (DDR), due to the limited number of available studies. Here, we aimed to perform a robust analysis in three consecutive vintages (2018, 2019, and 2020) on the impact of deficit irrigation on the yield, berry quality traits, and metabolome of cv. ‘Touriga Nacional’. Results showed that in the peaks of extreme drought, irrigation at 30% crop evapotranspiration (ETc) (R30) was able to prevent a decay of up to 0.4 MPa of leaf predawn water potential (ΨPd), but irrigation at 70% ETc (R70) did not translate into additional protection against drought stress. Following three seasons of irrigation, the yield was significantly improved in vines irrigated at R30, whereas irrigation at R70 positively affected the yield only in the 2020 season. Berry quality traits at harvest were not significantly changed by irrigation, except for Total Soluble Solids (TSS) in 2018. A UPLC–MS-based targeted metabolomic analysis identified eight classes of compounds, amino acids, phenolic acids, stilbenoid DP1, stilbenoid DP2, flavonols, flavan-3-ols, di-OH- and tri-OH anthocyanins, and showed that anthocyanins and phenolic acids did not change significantly with irrigation. The present study showed that deficit irrigation partially mitigated the severe summer water deficit conditions in the DDR but did not significantly change key metabolites.This research was funded by the VISCA project (Vineyards’ Integrated Smart Climate Application), funded by European Union’s Horizon 2020 research and innovation programme under grant agreement no. 730253. The Région-Centre Val de Loire (France) supported this work under the grant agreement to Project VITI’ACTIF. The work was also supported by the “Contrato-Programa” UIDB/04050/2020 funded by Portuguese national funds through the FCT I.P. The work was also supported by FCT, CCDR-N (Norte Portugal Regional Coordination and Development Commission) and European Funds (FEDER/POCI/COMPETE2020) through the project AgriFoodXXI (NORTE01-0145-FEDER-000041) and the research projects BerryPlastid (PTDC/BIA-FBT/28165/2017 and POCI-01-0145-FEDER-028165), MitiVineDrought (PTDC/BIA-FBT/30341/2017 and POCI-01-0145- FEDER-030341), and GrapeInfectomics (PTDC/ASPHOR/28485/2017). A.T. was supported by a post-doctoral researcher contract/position within the project “BerryPlastid”. This work also benefited from the networking activities within the European COST Action CA 17111 INTEGRAPE, the CoLAB VINES & WINES, and the CoLAB 4FOOD—Collaborative Laboratory for Innovation in the Food Industry

    Cytotoxic CD8+ T cell-neuron interactions: perforin-dependent electrical silencing precedes but is not causally linked to neuronal cell death

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    Cytotoxic CD8(+) T cells are considered important effector cells contributing to neuronal damage in inflammatory and degenerative CNS disorders. Using time-lapse video microscopy and two-photon imaging in combination with whole-cell patch-clamp recordings, we here show that major histocompatibility class I (MHC I)-restricted neuronal antigen presentation and T cell receptor specificity determine CD8(+) T-cell locomotion and neuronal damage in culture and hippocampal brain slices. Two separate functional consequences result from a direct cell-cell contact between antigen-presenting neurons and antigen-specific CD8(+) T cells. (1) An immediate impairment of electrical signaling in single neurons and neuronal networks occurs as a result of massive shunting of the membrane capacitance after insertion of channel-forming perforin (and probably activation of other transmembrane conductances), which is paralleled by an increase of intracellular Ca(2+) levels (within <10 min). (2) Antigen-dependent neuronal apoptosis may occur independently of perforin and members of the granzyme B cluster (within approximately 1 h), suggesting that extracellular effects can substitute for intracellular delivery of granzymes by perforin. Thus, electrical silencing is an immediate consequence of MHC I-restricted interaction of CD8(+) T cells with neurons. This mechanism is clearly perforin-dependent and precedes, but is not causally linked, to neuronal cell death

    Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: A multi-centre study

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    The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40–50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses
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