Computing the local pressure in molecular dynamics simulations

Computer simulations of inhomogeneous soft matter systems often require accurate methods for computing the local pressure. We present a simple derivation, based on the virial relation, of two equivalent expressions for the local (atomistic) pressure in a molecular dynamics simulation. One of these expressions, previously derived by other authors via a different route, involves summation over interactions between particles within the region of interest; the other involves summation over interactions across the boundary of the region of interest. We illustrate our derivation using simulations of a simple osmotic system; both expressions produce accurate results even when the region of interest over which the pressure is measured is very small.Comment: 11 pages, 4 figure

Highly efficient and selective extraction of uranium from aqueous solution by a magnetic device: succinyl-ß-cyclodextrin-APTES@maghemite nanoparticles

The removal of radio-elements, notably uranium, from waste-waters is crucial for public health and environmental remediation. To this end, succinyl-ß-cyclodextrin (SßCD) is grafted onto maghemite nanoparticles (NPs) synthesized by the polyol method. The nanocomposite was well characterized. The adsorption of U(VI) by SßCD-APTES@Fe2O3 is pH-dependent with a maximum at pH 6. Adsorption occurs mainly by complex formation and displays a very good selectivity for U(VI) compared to other cations such as Cs+, K+, Na+, Mg2+ and Al3+. The data were plotted according to the Langmuir, Freundlich, Elovich, Temkin and Halsey isotherms. The Langmuir isotherm maximum adsorption capacity (qmax) is 286 mg U g-1 and higher than for other reported sorbents. Moreover, Cs-corrected STEM visualizes the uranium on the NP surface, which is consistent with the Halsey isotherm model for multilayer adsorption. The U(VI) adsorbed on SßCD-APTES@Fe2O3 is easily recovered by magnetic sedimentation and desorption performed in a small volume in order to concentrate the extract. The nanocomposite can be regenerated and re-used at least tenfold

Interprofessional spiritual care education in pediatric hematology-oncology: A pilot study.

Background Evidence and clinical guidelines call care team members to address the spiritual well-being of pediatric patients, especially adolescents and young adults (AYA), with cancer and blood disorders. However, the lack of relevant training in generalist spiritual care has been a key barrier. Therefore, we aimed to improve clinicians’ capabilities by utilizing the Interprofessional Spiritual Care Education Curriculum (ISPEC) to close this gap in pediatric hematology-oncology. A model of interprofessional spiritual care entails that all team members attend to patients’ spirituality by employing generalist spiritual care skills and collaborating with spiritual care specialists such as chaplains. Methods Interdisciplinary team members providing care for AYA with cancer and blood disorders were recruited to participate in interprofessional spiritual care education. Our intervention combined an evidence-based online curriculum and in-person discussion groups. Pretest-posttest study examined changes in participants’ skills and practices to identify, address, and discuss spiritual concerns. Surveys were conducted at baseline and at 1, 3, and 6 months after the intervention. Results Participants (n = 21) included physicians, advanced practice providers, nurse coordinators, and psychosocial team members. We observed positive changes in participants’ ability (36%, P < 0.01), frequency (56%, P = 0.01), confidence (32%, P < 0.01), and comfort (31%, P = 0.02) providing generalist spiritual care baseline versus one month, with significant gains maintained through six months (Omnibus P < 0.05). Conclusions Utilizing ISPEC, interprofessional spiritual care education has a strong potential to develop pediatric hematology-oncology team members’ capabilities to attend to the spiritual aspect of whole-person care and thus contribute to the well-being of AYA with cancer and blood disorders

Topological complexity of the relative closure of a semi-Pfaffian couple

Gabrielov introduced the notion of relative closure of a Pfaffian couple as an alternative construction of the o-minimal structure generated by Khovanskii's Pfaffian functions. In this paper, use the notion of format (or complexity) of a Pfaffian couple to derive explicit upper-bounds for the homology of its relative closure. Keywords: Pfaffian functions, fewnomials, o-minimal structures, Betti numbers.Comment: 12 pages, 1 figure. v3: Proofs and bounds have been slightly improve

Defense-Inducing Volatiles: In Search of the Active Motif

Herbivore-induced volatile organic compounds (VOCs) are widely appreciated as an indirect defense mechanism since carnivorous arthropods use VOCs as cues for host localization and then attack herbivores. Another function of VOCs is plant–plant signaling. That VOCs elicit defensive responses in neighboring plants has been reported from various species, and different compounds have been found to be active. In order to search for a structural motif that characterizes active VOCs, we used lima bean (Phaseolus lunatus), which responds to VOCs released from damaged plants with an increased secretion of extrafloral nectar (EFN). We exposed lima bean to (Z)-3-hexenyl acetate, a substance naturally released from damaged lima bean and known to induce EFN secretion, and to several structurally related compounds. (E)-3-hexenyl acetate, (E)-2-hexenyl acetate, 5-hexenyl acetate, (Z)-3-hexenylisovalerate, and (Z)-3-hexenylbutyrate all elicited significant increases in EFN secretion, demonstrating that neither the (Z)-configuration nor the position of the double-bond nor the size of the acid moiety are critical for the EFN-inducing effect. Our result is not consistent with previous concepts that postulate reactive electrophile species (Michael-acceptor-systems) for defense-induction in Arabidopsis. Instead, we postulate that physicochemical processes, including interactions with odorant binding proteins and resulting in changes in transmembrane potentials, can underlie VOCs-mediated signaling processes

Radiative rotational lifetimes and state-resolved relative detachment cross sections from photodetachment thermometry of molecular anions in a cryogenic storage ring

Photodetachment thermometry on a beam of OH$^-$ in a cryogenic storage ring cooled to below 10 K is carried out using two-dimensional, frequency and time dependent photodetachment spectroscopy over 20 minutes of ion storage. In equilibrium with the low-level blackbody field, we find an effective radiative temperature near 15 K with about 90% of all ions in the rotational ground state. We measure the J = 1 natural lifetime (about 193 s) and determine the OH$^-$ rotational transition dipole moment with 1.5% uncertainty. We also measure rotationally dependent relative near-threshold photodetachment cross sections for photodetachment thermometry.Comment: Manuscript LaTeX with 5 pages, 3 figures, and 1 table plus LaTeX supplement with 12 pages, 3 figures and 3 tables. This article has been accepted by Physical Review Letter

The Huygens Atmospheric Structure Instrument (HASI): Expected Results at Titan and Performance Verification in Terrestrial Atmosphere

The Huygens ASI is a multi-sensor package resulting from an international cooperation, it has been designed to measure the physical quantities characterizing Titan's atmosphere during the Huygens probe mission. On 14th January, 2005, HASI will measure acceleration, pressure, temperature and electrical properties all along the Huygens probe descent on Titan in order to study Titan s atmospheric structure, dynamics and electric properties. Monitoring axial and normal accelerations and providing direct pressure and temperature measurements during the descent, HASI will mainly contribute to the Huygens probe entry and trajectory reconstruction. In order to simulate the Huygens probe descent and verify HASI sensors performance in terrestrial environment, stratospheric balloon flight experiment campaigns have been performed, in collaboration with the Italian Space Agency (ASI). The results of flight experiments have allowed to determine the atmospheric vertical profiles and to obtain a set of data for the analysis of probe trajectory and attitude reconstruction

XANTHENE DYES SHELL FORMATION ONTO NANOSCALE KEPLERATE {MO132} SURFACE: NMR AND PHOTOPHYSICAL STUDIES

This work was supported by Russian Science Foundation: Project No.21-73-00311

Understanding the dynamics of Toll-like Receptor 5 response to flagellin and its regulation by estradiol

© 2017 The Author(s). Toll-like receptors (TLRs) are major players of the innate immune system. Once activated, they trigger a signalling cascade that leads to NF-ΰ B translocation from the cytoplasm to the nucleus. Single cell analysis shows that NF-ΰ B signalling dynamics are a critical determinant of transcriptional regulation. Moreover, the outcome of innate immune response is also affected by the cross-talk between TLRs and estrogen signalling. Here, we characterized the dynamics of TLR5 signalling, responsible for the recognition of flagellated bacteria, and those changes induced by estradiol in its signalling at the single cell level. TLR5 activation in MCF7 cells induced a single and sustained NF-k B translocation into the nucleus that resulted in high NF-k B transcription activity. The overall magnitude of NF-k B transcription activity was not influenced by the duration of the stimulus. No significant changes are observed in the dynamics of NF-k B translocation to the nucleus when MCF7 cells are incubated with estradiol. However, estradiol significantly decreased NF-k B transcriptional activity while increasing TLR5-mediated AP-1 transcription. The effect of estradiol on transcriptional activity was dependent on the estrogen receptor activated. This fine tuning seems to occur mainly in the nucleus at the transcription level rather than affecting the translocation of the NF-k B transcription factor