Heparins are linear sulfated polysaccharides widely used as anticoagulant drugs. Their nonreducing-end (NRE) has been little investigated due to challenges in their characterization, but is known to ...be partly generated by enzymatic cleavage with heparanases, resulting in
-sulfated glucosamines at the NRE. Uronic NRE (specifically glucuronic acids) have been isolated from porcine heparin, with GlcA-GlcNS,3S,6S identified as a porcine-specific NRE marker. To further characterize NRE in heparinoids, a building block analysis involving exhaustive heparinase digestion and subsequent reductive amination with sulfanilic acid was performed. This study describes a new method for identifying heparin classical building blocks and novel NRE building blocks using strong anion exchange chromatography on AS11 columns for the assay, and ion-pair liquid chromatography-mass spectrometry for building block identification. Porcine, ovine, and bovine intestine heparins were analyzed. Generally, NRE on these three heparins are highly sulfated moieties, particularly with 3-
sulfates, and the observed composition of the NRE is highly dependent on heparin origin. At the highest level of specificity, the isolated marker was only detected in porcine heparin. However, the proportion of glucosamines in the NRE and the proportion of glucuronic/iduronic configurations in the NRE uronic moieties greatly varied between heparin types.
Types I and II Keratin Intermediate Filaments Jacob, Justin T; Coulombe, Pierre A; Kwan, Raymond ...
Cold Spring Harbor perspectives in biology,
04/2018, Letnik:
10, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Keratins-types I and II-are the intermediate-filament-forming proteins expressed in epithelial cells. They are encoded by 54 evolutionarily conserved genes (28 type I, 26 type II) and regulated in a ...pairwise and tissue type-, differentiation-, and context-dependent manner. Here, we review how keratins serve multiple homeostatic and stress-triggered mechanical and nonmechanical functions, including maintenance of cellular integrity, regulation of cell growth and migration, and protection from apoptosis. These functions are tightly regulated by posttranslational modifications and keratin-associated proteins. Genetically determined alterations in keratin-coding sequences underlie highly penetrant and rare disorders whose pathophysiology reflects cell fragility or altered tissue homeostasis. Furthermore, keratin mutation or misregulation represents risk factors or genetic modifiers for several additional acute and chronic diseases.
North African populations are distinct from sub-Saharan Africans based on cultural, linguistic, and phenotypic attributes; however, the time and the extent of genetic divergence between populations ...north and south of the Sahara remain poorly understood. Here, we interrogate the multilayered history of North Africa by characterizing the effect of hypothesized migrations from the Near East, Europe, and sub-Saharan Africa on current genetic diversity. We present dense, genome-wide SNP genotyping array data (730,000 sites) from seven North African populations, spanning from Egypt to Morocco, and one Spanish population. We identify a gradient of likely autochthonous Maghrebi ancestry that increases from east to west across northern Africa; this ancestry is likely derived from "back-to-Africa" gene flow more than 12,000 years ago (ya), prior to the Holocene. The indigenous North African ancestry is more frequent in populations with historical Berber ethnicity. In most North African populations we also see substantial shared ancestry with the Near East, and to a lesser extent sub-Saharan Africa and Europe. To estimate the time of migration from sub-Saharan populations into North Africa, we implement a maximum likelihood dating method based on the distribution of migrant tracts. In order to first identify migrant tracts, we assign local ancestry to haplotypes using a novel, principal component-based analysis of three ancestral populations. We estimate that a migration of western African origin into Morocco began about 40 generations ago (approximately 1,200 ya); a migration of individuals with Nilotic ancestry into Egypt occurred about 25 generations ago (approximately 750 ya). Our genomic data reveal an extraordinarily complex history of migrations, involving at least five ancestral populations, into North Africa.
Abstract
We propose a “guide” towards quantisation of gravity based on quantum matter in a statistical mechanics context. On one hand, a statistical mechanics model naturally arises from the ...thermodynamic interpretation of horizons in Rindler space. On the other hand, the path integral formulation of quantum field theory can be interpreted from the point of view of statistical mechanics. From these perspectives, gravity and matter are related to each other in the same way as a gas and its chemical potential are. This statistical mechanics interpretation of gravity and matter suggests that gravity should be quantised in a precise way which is determined by the quantisation of matter. Although, in a first step, quantisation of gravity applies for small perturbations of the metric with respect to the vacuum, the most central and general features of quantisation (quantisation prescription, quantum space dimensions) are supported from statistical mechanics and remain valid non-perturbatively.
Intermediate filaments (IFs) are cytoskeletal polymers whose protein constituents are encoded by a large family of differentially expressed genes. Owing in part to their properties and intracellular ...organization, IFs provide crucial structural support in the cytoplasm and nucleus, the perturbation of which causes cell and tissue fragility and accounts for a large number of genetic diseases in humans. A number of additional roles, nonmechanical in nature, have been recently uncovered for IF proteins. These include the regulation of key signaling pathways that control cell survival, cell growth, and vectorial processes including protein targeting in polarized cellular settings. As this discovery process continues to unfold, a rationale for the large size of this family and the context-dependent regulation of its members is finally emerging.
We investigate the properties of magnon edge states in a ferromagnetic honeycomb lattice with armchair boundaries. In contrast with fermionic graphene, we find novel edge states due to the missing ...bonds along the boundary sites. After introducing an external on-site potential at the outermost sites we find that the energy spectra of the edge states are tunable. Additionally, when a non-trivial gap is induced, we find that some of the edge states are topologically protected and also tunable. Our results may explain the origin of the novel edge states recently observed in photonic lattices. We also discuss the behavior of these edge states for further experimental confirmations.
•Novel edge states in a ferromagnetic honeycomb lattice with armchair boundaries are obtained.•The missing bonds along the boundary sites make the edge itself a defect and Tamm-like edge states are thus induced.•The Tamm-like edge states are strongly sensitive to external on-site potentials.•The external on-site potential can also be used to tune the topologically protected edge states.
Central pattern generators (CPGs) are generally defined as networks of neurons capable of enabling the production of central commands, specifically controlling stereotyped, rhythmic motor behaviors. ...Several CPGs localized in brainstem and spinal cord areas have been shown to underlie the expression of complex behaviors such as deglutition, mastication, respiration, defecation, micturition, ejaculation, and locomotion. Their pivotal roles have clearly been demonstrated although their organization and cellular properties remain incompletely characterized. In recent years, insightful findings about CPGs have been made mainly because (1) several complementary animal models were developed; (2) these models enabled a wide variety of techniques to be used and, hence, a plethora of characteristics to be discovered; and (3) organizations, functions, and cell properties across all models and species studied thus far were generally found to be well-preserved phylogenetically. This article aims at providing an overview for non-experts of the most important findings made on CPGs in
animal models,
preparations from invertebrate and vertebrate species as well as in primates. Data about CPG functions, adaptation, organization, and cellular properties will be summarized with a special attention paid to the network for locomotion given its advanced level of characterization compared with some of the other CPGs. Similarities and differences between these networks will also be highlighted.
The lack of comprehensive data on the association between psychiatric and substance use disorders and habitual sleep duration represents a major health information gap. This study examines the ...12-month prevalence of mental disorders stratified by duration of sleep. Data were drawn from face-to-face interviews conducted in the National Epidemiologic Survey on Alcohol and Related Conditions III, a nationally representative survey of US adults (N = 36,309). There were 1893 (5.26%) participants who reported <5h of sleep/night; 2434(6.76%) 5 h/night; 7621(21.17%) 6 h/night; 9620(26.72%) 7 h/night; 11,186(31.07%) 8 h/night, and 3245(9.01%) ≥9 h/night. A U-shaped association was observed between sleep duration and all mental disorders. The prevalence of mental disorders was 55% for individuals with <5 h/night and 47.81% for ≥9 h/night, versus 28.24% for the 7 h/night (aOR = 1.90 and 1.39 respectively). The greatest odds ratios were for the <5 h/night group, with an increased risk above 3-fold for panic disorder (PD), post-traumatic stress disorder (PTSD), psychotic disorder, and suicide attempt; between 2 and 3 fold for major depressive disorder (MDD), bipolar disorder (BD), and generalized anxiety disorder (GAD); and between 1 and 2 fold for tobacco and drug use disorders, specific and social phobias. The ≥9 h/night group had an increased risk above 1 to 2-fold regarding tobacco and drug use disorders, MDD, BD, PD, social phobia, GAD, PTSD, psychotic disorder, and suicide attempt. U-shaped associations exist between sleep duration and mental disorders, calling for respect to recommendations for adequate sleep duration in routine clinical care as well as to actions for primary prevention in public health settings.
•This study present nationally representative data on the prevalence of mental disorders stratified by duration of sleep.•A U-shaped association was observed between sleep duration and all psychiatric and substance use disorders.•Highest risks, exceeding a 3-fold increase for some mental disorders, were observed for short sleepers, especially for the <5h/night group.•Adequate sleep duration may have general clinical benefits, calling for actions for primary prevention in public health settings.
Transition from petroleum‐ to biomass‐based fuel economy will require new conversion strategies. In a petroleum refinery, particular hydrocarbon fractions from crude oil are catalytically converted ...into high‐grade fuels. Certain zeolite catalysts are performing exceptionally well. Unlike petroleum fractions, biomass‐derived compounds have a high oxygen content requiring low‐temperature catalytic aqueous phase processes for selective conversion and stability of zeolite catalysts in hot liquid water. It will be shown that recent developments in zeolite synthesis and modification allow adapting zeolite properties to achieve selective conversion of biomass compounds/fractions as well.
Approved catalysts for fuels of the future: Transition from petroleum‐ to biomass‐based fuel economy will require new conversion strategies. This Essay describes how recent developments in zeolite synthesis and modification allow adapting zeolite properties to achieve selective conversion of biomass compounds.
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