345 research outputs found

    Evaluation of Carboxymethyl-Hexanoyl Chitosan as a Protein Nanocarrier

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    Carboxymethyl‐hexanoyl chitosan (CHC) has the ability to self‐assemble into nanocapsules in an aqueous solution and it has recently shown potential in numerous biomedical applications. Here we investigate the protein loading efficiency and release, as well as the structural properties of CHC protein nanocarriers. Bovine serum albumin (BSA) or its chromophore labelled version, fluorescein‐BSA, was used as a model protein and the loading was performed with a simple mixing of pre‐formed nanocapsules and protein. Dynamic light scattering and zeta potential analysis revealed that protein loaded nanocarriers with high positive zeta potential were formed. The protein loaded nanocarriers displayed a loading efficiency of 75% and a very slow protein release. In summary, our results highlight the potential of CHC as a protein nanocarrier, but also indicate that protein‐CHC interactions need to be considered in protein containing CHC formulations where protein release is not the main function

    Born's rule from measurements of classical signals by threshold detectors which are properly calibrated

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    The very old problem of the statistical content of quantum mechanics (QM) is studied in a novel framework. The Born's rule (one of the basic postulates of QM) is derived from theory of classical random signals. We present a measurement scheme which transforms continuous signals into discrete clicks and reproduces the Born's rule. This is the sheme of threshold type detection. Calibration of detectors plays a crucial role.Comment: The problem of double clicks is resolved; hence, one can proceed in purely wave framework, i.e., the wave-partcile duality has been resolved in favor of the wave picture of prequantum realit

    Studies of the collision-based Xe VI and Xe VII spectra

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    Collision-based spectroscopy of a Xeq+ (q = 6, 7) beam with a target T (T = Na, Ar) has been performed in the 35-800-nm wavelength region. Twenty-five new Xe VI lines and twenty-two new Xe VII lines were classified, twelve new energy levels of Xe VI and nine new energy levels of Xe VII were established, and one energy level of Xe VI was revised from the classified transitions. The analysis was supported by Hartree-Fock calculations. (C) 1997 Optical Society of America [S0740-3224(97)00512-2].14123277328

    TillstÄnd och trender för arter och deras livsmiljöer

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    2015 Ärs upplaga av den svenska rödlistan Àr den fjÀrde i ordningen. Den Àr baserad pÄ IUCN:s rödlistningskriterier och revideras vart femte Är. I rödlistan bedöms risken som enskilda arter av djur, vÀxter och svampar löper att försvinna frÄn Sverige. Bedömningen utförs av ArtDatabankens medarbetare i samverkan med över 100 externa experter, indelade i 14 expertkommittéer för olika organismgrupper. Under arbetet med 2015 Ärs rödlista har tillstÄnd och trender bedömts för 21 600 arter och 1 318 lÀgre taxa (apomiktiska arter, underarter och varieteter), sammanlagt ca 22 900 taxa. Av de bedömda arterna klassificerades 2 029 som hotade (kategorierna CR, EN och VU) och 4 273 som rödlistade (inkluderar Àven kategorierna NT, RE och DD). FörhÄllandet mellan antalet rödlistade och antalet bedömda arter ar 19,8 %, vilket Àr ungefÀr samma vÀrde som 2010 och 2005. I denna rapport jÀmförs antalet och andelen rödlistade arter mellan olika organismgrupper, biotoper, substrat och pÄverkansfaktorer. Texten ar indelad i en allmÀn del och Ätta kapitel inriktade pÄ olika landskapstyper. Landskapstyperna utgör en grov indelning av landets miljöer enligt följande kategorier: Skog, Jordbrukslandskap, Urbana miljöer, FjÀll, VÄtmarker, Sötvatten, HavsstrÀnder och Havsmiljöer. Skogen och jordbrukslandskapet Àr de artrikaste landskapstyperna med 1 800 respektive 1 400 arter som har en stark anknytning dit, och ytterligare flera hundra arter som förekommer dÀr mer sporadiskt. De faktorer som pÄverkar flest rödlistade arter i Sverige Àr skogsavverkning och igenvÀxning, som bÄda utgör ett hot mot vardera ca 30 % av de rödlistade arterna. Avverkning minskar arealen av skog dÀr naturliga strukturer och naturlig dynamik upprÀtthÄlls, och den orsakar dÀrmed förlust av livsmiljöer. IgenvÀxning orsakas av ett antal faktorer, bland annat upphörande hÀvd (bete och slÄtter), gödsling, trÀdplantering och brist pÄ naturliga störningsregimer som t.ex. regelbundna översvÀmningar kring vattendrag och sjöar. Andra viktiga pÄverkansfaktorer Àr fiske, torrlÀggning av vÄtmarker, tillbakagÄng hos vÀrdarter (frÀmst alm och ask som drabbats av invasiva svampsjukdomar), klimatförÀndringar och konkurrens frÄn invasiva arter. IUCN:s rödlisteindex berÀknas för ett urval av de bedömda organismgrupperna. Rödlisteindex visar att skillnaderna mellan rödlistorna frÄn 2000, 2005, 2010 och 2015 Àr smÄ. Ett par undantag finns dock. Groddjur och stora dÀggdjur har fÄtt en nÄgot förbÀttrad situation sedan 2000. Totalt förefaller det ÀndÄ som att trycket mot Sveriges artstock har förblivit relativt konstant under de senaste 15 Ären

    Testing foundations of quantum mechanics with photons

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    The foundational ideas of quantum mechanics continue to give rise to counterintuitive theories and physical effects that are in conflict with a classical description of Nature. Experiments with light at the single photon level have historically been at the forefront of tests of fundamental quantum theory and new developments in photonics engineering continue to enable new experiments. Here we review recent photonic experiments to test two foundational themes in quantum mechanics: wave-particle duality, central to recent complementarity and delayed-choice experiments; and Bell nonlocality where recent theoretical and technological advances have allowed all controversial loopholes to be separately addressed in different photonics experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review articl

    Sustained proliferation in cancer: mechanisms and novel therapeutic targets

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    Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression

    Region-Specific Expression of Mitochondrial Complex I Genes during Murine Brain Development

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    Mutations in the nuclear encoded subunits of mitochondrial complex I (NADH:ubiquinone oxidoreductase) may cause circumscribed cerebral lesions ranging from degeneration of the striatal and brainstem gray matter (Leigh syndrome) to leukodystrophy. We hypothesized that such pattern of regional pathology might be due to local differences in the dependence on complex I function. Using in situ hybridization we investigated the relative expression of 33 nuclear encoded complex I subunits in different brain regions of the mouse at E11.5, E17.5, P1, P11, P28 and adult (12 weeks). With respect to timing and relative intensity of complex I gene expression we found a highly variant pattern in different regions during development. High average expression levels were detected in periods of intense neurogenesis. In cerebellar Purkinje and in hippocampal CA1/CA3 pyramidal neurons we found a second even higher peak during the period of synaptogenesis and maturation. The extraordinary dependence of these structures on complex I gene expression during synaptogenesis is in accord with our recent findings that gamma oscillations – known to be associated with higher cognitive functions of the mammalian brain – strongly depend on the complex I activity. However, with the exception of the mesencephalon, we detected only average complex I expression levels in the striatum and basal ganglia, which does not explain the exquisite vulnerability of these structures in mitochondrial disorders

    Physician Experiences and Understanding of Genomic Sequencing in Oncology

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    The amount of information produced by genomic sequencing is vast, technically complicated, and can be difficult to interpret. Appropriately tailoring genomic information for nonĂą geneticists is an essential next step in the clinical use of genomic sequencing. To initiate development of a framework for genomic results communication, we conducted eighteen qualitative interviews with oncologists who had referred adult cancer patients to a matched tumorĂą normal tissue genomic sequencing study. In our qualitative analysis, we found varied levels of clinician knowledge relating to sequencing technology, the scope of the tumor genomic sequencing study, and incidental germline findings. Clinicians expressed a perceived need for more genetics education. Additionally, they had a variety of suggestions for improving results reports and possible resources to aid in results interpretation. Most clinicians felt genetic counselors were needed when incidental germline findings were identified. Our research suggests that more consistent genetics education is imperative in ensuring the proper utilization of genomic sequencing in cancer care. Clinician suggestions for results interpretation resources and results report modifications could be used to improve communication. CliniciansĂą perceived need to involve genetic counselors when incidental germline findings were found suggests genetic specialists could play a critical role in ensuring patients receive appropriate followĂą up.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147187/1/jgc40187.pd
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