111 research outputs found
Impact of lactoferrin on bone regenerative processes and its possible implementation in oral surgery - a systematic review of novel studies with metanalysis and metaregression
Background: Lactoferrin is an iron - binding glycoprotein with anti-inflammatory and anabolic properties found in many internal fluids. It is worth looking at novel studies, because of their methodology and observations that may once be applicable in modern implantology. The aim of the study is to answer the question if lactoferrin is a promising factor for bone regenerative process in oral surgery. Method: An electronic search was conducted on 14th October 2019 on the PubMed, Scopus and Web of Science databases. The keywords used in the search strategy were: lactoferrin AND bone regeneration AND oral surgery. The qualitative evaluation was conducted using the Jadad and Newcastle-Ottawa Quality Assessment Form. Then a metanalysis of a new bone growth and percentage of the resorbed graft were performed with the metaregression of lactoferrin dose to its outcome effects on bone regeneration. Results: The search strategy identified potential articles: 133 from PubMed, 2 from Scopus, 4 from Web of science. After removal of duplicates, 136 articles were analyzed. Subsequently, 131 papers were excluded because they did not meet the inclusion criteria. The remaining 5 papers were included in the qualitative synthesis. The use of lactoferrin clearly increases the growth of a newly formed bone (2.58, CI:[0.79, 4.37]), as well as shortens the time of the graft resorption (- 1.70, Cl:[3.43, 0.03]) and replaces it with a species-specific bone. Heterogeneity is significant at p < 0.001 level. Metaregression indicates that one unit increase in the log (Treatment dose), i.e. a 2.78 times increase of the Treatment dose, results in an increase of the Effect size by 0.682. Conclusions: The use of lactoferrin both systemically and locally promotes anabolic processes (new bone formation). There is a relationship between the increase in administered dose of lactoferrin and the intensity of new bone formation. However, it is not only necessary to continue experimental research, but also to extend it to the clinical studies on patients, due to the limitations of different animal model research and different methodology, to introduce lactoferrin as a standard procedure for the treatment of bone defects, because it is a promising product
Copper-Catalyzed Enantioselective Allylic Alkylation with a γ-Butyrolactone-Derived Silyl Ketene Acetal
Herein, we report a Cu‐catalyzed enantioselective allylic alkylation using a γ‐butyrolactone‐derived silyl ketene acetal. Critical to the development of this work was the identification of a novel mono‐picolinamide ligand with the appropriate steric and electronic properties to afford the desired products in high yield (up to 96 %) and high ee (up to 95 %). Aryl, aliphatic, and unsubstituted allylic chlorides bearing a broad range of functionality are well‐tolerated. Spectroscopic studies reveal that a Cu^I species is likely the active catalyst, and DFT calculations suggest ligand sterics play an important role in determining Cu coordination and thus catalyst geometry
Reflections on the Shifting Shape of Journalism Education in the Covid-19 pandemic
Journalists usually report on crisis. The Covid -19 pandemic places journalists, like everyone else, in the crisis. Thus, it presents a unique challenge to journalism, which is founded on the principle of impartiality, and to journalism educators, striving to teach professional values in an online environment, whilst also focusing on student wellbeing. This paper shares the initial reflections of journalism practitioners who are members of a journalism education research group within the Centre for Excellence in Media Practice at Bournemouth University in the UK. The overarching theme considers the delivery of high quality, industry - facing and relevant journalism education in a digital environment and within a context where we are all part of the story. We reflect on building community and identity for undergraduate and postgraduate students; the challenges of teaching the normative values and skills of journalism (such as objectivity, accuracy, fairness), emotional literacy and the delivery of industry-accredited standards. These individual reflections are presented as a collective essay which engages with questions of identity, self and voice: how can we instil a sense of wellbeing in journalism students who may feel anxious and marginalised? How can they focus on telling the stories of others when they are part of the same story? How can we best engage with these challenges in a digital environment, whilst instilling an understanding of the importance of self–care and wellbeing? In responding and adapting to crisis, we have also discovered - through the work of our students in the virtual classroom - new ways of teaching journalism and innovative approaches to storytelling as we grapple together with the shifting shapes of journalism practice and journalism education
Intraoperative detection of insufficient surgical margins in head and neck cancer resection using dual aperture fluorescence ratio imaging
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Dust-free quasars in the early Universe
The most distant quasars known, at redshifts z=6, generally have properties
indistinguishable from those of lower-redshift quasars in the rest-frame
ultraviolet/optical and X-ray bands. This puzzling result suggests that these
distant quasars are evolved objects even though the Universe was only seven per
cent of its current age at these redshifts. Recently one z=6 quasar was shown
not to have any detectable emission from hot dust, but it was unclear whether
that indicated different hot-dust properties at high redshift or if it is
simply an outlier. Here we report the discovery of a second quasar without
hot-dust emission in a sample of 21 z=6 quasars. Such apparently hot-dust-free
quasars have no counterparts at low redshift. Moreover, we demonstrate that the
hot-dust abundance in the 21 quasars builds up in tandem with the growth of the
central black hole, whereas at low redshift it is almost independent of the
black hole mass. Thus z=6 quasars are indeed at an early evolutionary stage,
with rapid mass accretion and dust formation. The two hot-dust-free quasars are
likely to be first-generation quasars born in dust-free environments and are
too young to have formed a detectable amount of hot dust around them.Comment: To be published in Nature on the 18 March 2010
Schemes for generation of isolated attosecond pulses of pure circular polarization
We propose and analyze two schemes capable of generating isolated attosecond pulses of pure circular polarization, based on results of numerical simulations. Both schemes utilize the generation of circularly polarized high-order-harmonics by crossing two circularly polarized counter-rotating pulses in a noncollinear geometry. Our results show that in this setup isolation of a single attosecond pulse can be achieved either by restricting the driver pulse duration to a few cycles or by temporally delaying the two crossed driver pulses. We further propose to compensate the temporal walk-off between the pulses across the focal spot and increasing the conversion efficiency by using angular spatial chirp to provide perfectly matched pulse fronts. The isolation of pure circularly polarized attosecond pulses, along with the opportunity to select their central energy and helicity in the noncollinear technique, opens new perspectives from which to study ultrafast dynamics in chiral systems and magnetic materials.The authors acknowledge Luis Plaja for valuable discussions. C.H.-G. acknowledges support from the Marie Curie International Outgoing Fellowship within the EU Seventh Framework Programme for Research and Technological Development (2007–2013), under REA Grant Agreement No. 328334. C.H.-G. and I.J.S. acknowledge support from Junta de Castilla y León (Project SA116U13, UIC016) and MINECO (Grants No. FIS2013-44174-P and No. FIS2015-71933-REDT). A.J.-B. was supported by grants from the U.S. National Science Foundation (Grants No. PHY-1125844 and No. PHY-1068706). D.H. was supported via a grant from the Department of Energy. M.M.M., H.C.K., C.G.D., and A.B. acknowledge support by a MURI grant from Air Force Office of Scientific Research under Award Number FA9550-16-1- 0121. This work utilized the Janus supercomputer, which is supported by the U.S. National Science Foundation (Grant No. CNS-0821794) and the University of Colorado Boulder
Fluorescence molecular imaging using cetuximab-800CW in cutaneous squamous cell carcinoma surgery:a proof-of-concept study
On positivity of Ehrhart polynomials
Ehrhart discovered that the function that counts the number of lattice points
in dilations of an integral polytope is a polynomial. We call the coefficients
of this polynomial Ehrhart coefficients, and say a polytope is Ehrhart positive
if all Ehrhart coefficients are positive (which is not true for all integral
polytopes). The main purpose of this article is to survey interesting families
of polytopes that are known to be Ehrhart positive and discuss the reasons from
which their Ehrhart positivity follows. We also include examples of polytopes
that have negative Ehrhart coefficients and polytopes that are conjectured to
be Ehrhart positive, as well as pose a few relevant questions.Comment: 40 pages, 7 figures. To appear in in Recent Trends in Algebraic
Combinatorics, a volume of the Association for Women in Mathematics Series,
Springer International Publishin
Bright Coherent Ultrahigh Harmonics in the keV X-ray Regime from Mid-Infrared Femtosecond Lasers
High-harmonic generation (HHG) traditionally combines ~100 near-infrared laser photons to generate bright, phase-matched, extreme ultraviolet beams when the emission from many atoms adds constructively. Here, we show that by guiding a mid-infrared femtosecond laser in a high-pressure gas, ultrahigh harmonics can be generated, up to orders greater than 5000, that emerge as a bright supercontinuum that spans the entire electromagnetic spectrum from the ultraviolet to more than 1.6 kilo–electron volts, allowing, in principle, the generation of pulses as short as 2.5 attoseconds. The multiatmosphere gas pressures required for bright, phase-matched emission also support laser beam self-confinement, further enhancing the x-ray yield. Finally, the x-ray beam exhibits high spatial coherence, even though at high gas density the recolliding electrons responsible for HHG encounter other atoms during the emission process.The experimental work was funded by a National Security Science and Engineering Faculty Fellowship, and the NSF Center for EUV Science and Technology. A.G., A.J.-B., M.M.M., H.C.K. and A. Becker acknowledge support for theory from the U.S. Air Force Office of Scientific Research (grant no. FA9550-10-1-0561); A. Baltuška acknowledges support from Austrian Science Fund (FWF, grant no. U33-16) and the Austrian Research Promotion Agency (FFG, Project 820831 UPLIT); and C.H.-G. and L.P. acknowledge support from Junta de Castilla y León, Spanish MINECO (CSD2007-00013 and FIS2009-09522), and from Centro de Láseres Pulsados, CLPU. T.P., M.-C.C., A. Bahabad, M.M.M. and H.C.K. have filed for a patent on “Method for phase-matched generation of coherent soft and hard X-rays using IR lasers,” U.S. patent application 61171783 (2008)
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