Correlation between membrane bending and lipidic composition during the sperm acrosomal exocytosis : computational analysis

Fil: Suhaiman, L..Fil: Borioni, J.L..Fil: Ferguson, M..Fil: Belmonte, S..Fil: Del Popolo, M. G.

Research in Extracorporeal Life Support: A Call to Action

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The CcmC-CcmE interaction during cytochrome c maturation by System I is driven by protein-protein and not protein-heme contacts.

Cytochromes c are ubiquitous proteins, essential for life in most organisms. Their distinctive characteristic is the covalent attachment of heme to their polypeptide chain. This post-translational modification is performed by a dedicated protein system, which in many Gram-negative bacteria and plant mitochondria is a nine-protein apparatus (CcmA-I) called System I. Despite decades of study, mechanistic understanding of the protein-protein interactions in this highly complex maturation machinery is still lacking. Here, we focused on the interaction of CcmC, the protein that sources the heme cofactor, with CcmE, the pivotal component of System I responsible for the transfer of the heme to the apocytochrome. Using in silico analyses, we identified a putative interaction site between these two proteins (residues Asp <sup>47</sup> , Gln <sup>50</sup> , and Arg <sup>55</sup> on CcmC; Arg <sup>73</sup> , Asp <sup>101</sup> , and Glu <sup>105</sup> on CcmE), and we validated our findings by in vivo experiments in Escherichia coli Moreover, employing NMR spectroscopy, we examined whether a heme-binding site on CcmE contributes to this interaction and found that CcmC and CcmE associate via protein-protein rather than protein-heme contacts. The combination of in vivo site-directed mutagenesis studies and high-resolution structural techniques enabled us to determine at the residue level the mechanism for the formation of one of the key protein complexes for cytochrome c maturation by System I

Can Surgical Trainees Achieve Arthroscopic Competence at the End of Training Programs? A Cross-sectional Study Highlighting the Impact of Working Time Directives.

PURPOSE: To provide training guidance on procedure numbers by assessing how the number of previously performed arthroscopic procedures relate to both competent and expert performance in simulated arthroscopic shoulder tasks. METHODS: A cross-sectional study that assessed simulated shoulder arthroscopic performance was undertaken. A total of 45 participants of varying experience performed 2 validated tasks: a simple diagnostic task and a more complex Bankart labral repair task. All participants provided logbook numbers for previously performed arthroscopies. Performance was assessed with the Global Rating Scale and motion analysis. Receiver operating characteristic curve analyses were conducted to identify optimum cut points for task proficiency at both "competent" and "expert" levels. RESULTS: Increasing surgical experience resulted in significantly better performance for both tasks as assessed by Global Rating Scale or motion analysis (P < .0001). Receiver operating characteristic curve analyses demonstrated 52 previous arthroscopies were needed to perform to a competent level at the diagnostic task and 248 to be competent at the complex task. To perform at an expert level, 290 and 476 previous arthroscopies, respectively, were needed. CONCLUSIONS: This study provides quantified guidance for arthroscopic training and highlights the positive relationship between arthroscopic case load and arthroscopic competency. We have estimated that the number of arthroscopies required to achieve competency in a basic arthroscopic task exceed those recommended in some countries. These estimates provide useful guidance to those responsible for training program. CLINICAL RELEVANCE: The numbers to achieve competent arthroscopic performance in the assessed simulated tasks exceed what is recommended and what is possible during surgical training programs in some countries

In Situ Synthesis of Molybdenum Carbide Nanoparticles Incorporated into Laser Patterned Nitrogen Doped Carbon for Room Temperature VOC Sensing

Carbon laser patterning CLaP is emerging as a new tool for the precise and selective synthesis of functional carbon based materials for on chip applications. The aim of this work is to demonstrate the applicability of laser patterned nitrogen doped carbon LP NC for resistive gas sensing applications. Films of pre carbonized organic nanoparticles on polyethylenetherephthalate are carbonized with a CO2 laser. Upon laser irradiation a compositional and morphological gradient in the films is generated with a carbon content of 92 near the top surface. The specific surface areas of the LP NC are increased by introducing sodium iodide NaI as a porogen. Electronic conductivity and surface area measurements corroborate the deeper penetration of the laser energy into the film in the presence of NaI. Furthermore, impregnation of LP NC with MoC1 x lt;10 nm nanoparticles is achieved by addition of ammonium heptamolybdate into the precursor film. The resulting doping sensitive nano grain boundaries between p type carbon and metallic MoC1 x lead to an improvement of the volatile organic compounds sensing response of Delta R R0 3.7 or 0.8 for 1250 ppm acetone or 900 ppm toluene at room temperature, respectively, which is competitive with carbon based sensor materials. Further advances in sensitivity and in situ functionalization are expected to make CLaP a useful method for printing selective sensor array

Sagittarius II, Draco II and Laevens 3: Three New Milky Way Satellites Discovered in the Pan-STARRS 1 3 Survey

We present the discovery of three new Milky Way satellites from our search for compact stellar overdensities in the photometric catalog of the Panoramic Survey Telescope and Rapid Response System 1 (Pan-STARRS 1, or PS1) 3π survey. The first satellite, Laevens 3, is located at a heliocentric distance of d = 67 ± 3 kpc. With a total magnitude of MV = −4.4 ± 0.3 and a half-light radius of rh = 7 ± 2 pc, its properties resemble those of outer halo globular clusters. The second system, Draco II/Laevens 4, is a closer and fainter satellite (d ~ 20 kpc, MV = −2.9 ± 0.8), whose uncertain size (${r}_{h}={19}_{-6}^{+8}\;\mathrm{pc}$) renders its classification difficult without kinematic information; it could either be a faint and extended globular cluster or a faint and compact dwarf galaxy. The third satellite, Sagittarius II/Laevens 5 (Sgr II), has an ambiguous nature, as it is either the most compact dwarf galaxy or the most extended globular cluster in its luminosity range (${r}_{h}={37}_{-8}^{+9}\;\mathrm{pc}$ and MV = −5.2 ± 0.4). At a heliocentric distance of 67 ± 5 kpc, this satellite lies intriguingly close to the expected location of the trailing arm of the Sagittarius stellar stream behind the Sagittarius dwarf spheroidal galaxy (Sgr dSph). If confirmed through spectroscopic follow up, this connection would locate this part of the trailing arm of the Sagittarius stellar stream that has so far gone undetected. It would further suggest that Sgr II was brought into the Milky Way halo as a satellite of the Sgr dSph

Pegasus IV: Discovery and Spectroscopic Confirmation of an Ultra-faint Dwarf Galaxy in the Constellation Pegasus

We report the discovery of Pegasus IV, an ultra-faint dwarf galaxy found in archival data from the Dark Energy Camera processed by the DECam Local Volume Exploration Survey. Pegasus IV is a compact, ultra-faint stellar system (r1 2 = 41-+68 pc; MV = −4.25 ± 0.2 mag) located at a heliocentric distance of 90-+64 kpc. Based on spectra of seven nonvariable member stars observed with Magellan/IMACS, we confidently resolve Pegasus IV’s velocity dispersion, measuring sv = 3.3-+1.11.7 km s−1 (after excluding three velocity outliers); this implies a mass-to-light ratio of M1 2 LV,1 2 = 167-+99224M☉ L☉ for the system. From the five stars with the highest signal-to-noise spectra, we also measure a systemic metallicity of [Fe/H] =-2.63-+0.300.26 dex, making Pegasus IV one of the most metal-poor ultra-faint dwarfs. We tentatively resolve a nonzero metallicity dispersion for the system. These measurements provide strong evidence that Pegasus IV is a dark-matter-dominated dwarf galaxy, rather than a star cluster. We measure Pegasus IV’s proper motion using data from Gaia Early Data Release 3, finding (μα*, μδ) = (0.33 ± 0.07, −0.21 ± 0.08) mas yr−1. When combined with our measured systemic velocity, this proper motion suggests that Pegasus IV is on an elliptical, retrograde orbit, and is currently near its orbital apocenter. Lastly, we identify three potential RR Lyrae variable stars within Pegasus IV, including one candidate member located more than 10 half-light radii away from the system’s centroid. The discovery of yet another ultra-faint dwarf galaxy strongly suggests that the census of Milky Way satellites is still incomplete, even within 100 kpc

A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3π Survey

We present the discovery of a faint Milky Way satellite, Laevens 2/Triangulum II, found in the Panoramic Survey Telescope And Rapid Response System (Pan-STARRS 1) 3 pi imaging data and confirmed with follow-up wide-field photometry from the Large Binocular Cameras. The stellar system, with an absolute magnitude of M_V=-1.8 +/-0.5, a heliocentric distance of 30 +2/-2 kpc, and a half-mass radius of 34 +9/-8 pc, shows remarkable similarity to faint, nearby, small satellites such as Willman 1, Segue 1, Segue 2, and Bo\"otes II. The discovery of Laevens 2/Triangulum II further populates the region of parameter space for which the boundary between dwarf galaxies and globular clusters becomes tenuous. Follow-up spectroscopy will ultimately determine the nature of this new satellite, whose spatial location hints at a possible connection with the complex Triangulum-Andromeda stellar structures

A bibliometric analysis of nursing and midwifery research in the Caribbean

Purpose: To determine the research output of Caribbean nurses and midwives. Methods: We searched the Scopus database to identify publications by Caribbean nurses and midwives during the period 2000–2020. Publications were included in the analysis if they had at least one author who was either a nurse or midwife and affiliated with a Caribbean geographic location. All publication types and languages were included in the analysis. Organization analysis and collaboration networks were created using the VOS Viewer application. Findings: The number of Scopus publications by Caribbean nurses and midwives progressively grew from 22 in 2000 to 584 in 2020. Cuba recorded the highest number of nursing research publications (319) followed by Jamaica (92), and Puerto Rico (59). Most publishing institutions were universities. The University of the West Indies (Jamaica) ranked highest with 15.2% of publications, followed by Universidad de Ciencias Médicas de La Habana with 14.4% of publications, Universidad de Puerto Rico ranked third with 9.8% of publications. The majority of publications (83.6%) were peer reviewed research articles, while review articles accounted for 9.8% of publications. Six out of the ten journals that published most research done by Caribbean nurse researchers were Cuban journals which published a total of n = 250 (75.8%) articles. All six journals had no impact factor and had low cite scores. Conclusions: Our analysis of bibliometric indicators suggest that recent and steady growth in nursing and midwifery research in the Caribbean has had low visibility. Equipping nurses and midwives with the necessary knowledge and skills to lead, teach, and conduct high quality research through doctorate level education is an imperative for increasing research productivity among Caribbean nurses and midwives. Clinical relevance: Nursing and midwifery research is critical for evidence-based nursing and midwifery practice. High quality and context specific research evidence will enable Caribbean nurses and midwives to provide quality and culturally sensitive nursing and midwifery care and contribute to evidence informed policy decisions