110 research outputs found
Loss of intranetwork and internetwork resting state functional connections with Alzheimer\u27s disease progression
Alzheimer\u27s disease (AD) is the most common cause of dementia. Much is known concerning AD pathophysiology but our understanding of the disease at the systems level remains incomplete. Previous AD research has used resting-state functional connectivity magnetic resonance imaging (rs-fcMRI) to assess the integrity of functional networks within the brain. Most studies have focused on the default-mode network (DMN), a primary locus of AD pathology. However, other brain regions are inevitably affected with disease progression. We studied rs-fcMRI in five functionally defined brain networks within a large cohort of human participants of either gender (n = 510) that ranged in AD severity from unaffected [clinical dementia rating (CDR) 0] to very mild (CDR 0.5) to mild (CDR 1). We observed loss of correlations within not only the DMN but other networks at CDR 0.5. Within the salience network (SAL), increases were seen between CDR 0 and CDR 0.5. However, at CDR 1, all networks, including SAL, exhibited reduced correlations. Specific networks were preferentially affected at certain CDR stages. In addition, cross-network relations were consistently lost with increasing AD severity. Our results demonstrate that AD is associated with widespread loss of both intranetwork and internetwork correlations. These results provide insight into AD pathophysiology and reinforce an integrative view of the brain\u27s functional organization
The Origin of Separable States and Separability Criteria from Entanglement-breaking Channels
In this paper, we show that an arbitrary separable state can be the output of
a certain entanglement-breaking channel corresponding exactly to the input of a
maximally entangled state. A necessary and sufficient separability criterion
and some sufficient separability criteria from entanglement-breaking channels
are given.Comment: EBCs with trace-preserving and EBCs without trace-preserving are
separately discusse
RP-HPLC-DAD metoda za odreÄivanje olmesartan medoksomila kao Äiste supstancije i u tabletama izloženih razgradnji
A simple, sensitive and precise RP-HPLC-DAD method was developed and validated for the determination of olmesartan medoxomil (AT-II receptor blocker) in the presence of its degradation products. Olmesartan medoxomil and all the degradation products were resolved on a C18 column with the mobile phase composed of methanol, acetonitrile and water (60:15:25, V/V/V, pH 3.5 by orthophosphoric acid) at 260 nm using a photodiode array detector. The method was linear over the concentration range of 1ā18 Āµg mL 1 and precise with RSD 2.0 for each peak and sensitive with LOD 0.03 Āµg mLā1 and LOQ 0.1 Āµg mLā1. The method was used to study the drug degradation behavior under forced conditions. Four degradation products (DP-I, II, III, IV) were formed during the degradation study in 0.1 mol Lā1 HCl whereas only DP-I, II and III were formed in water, 0.01 mol Lā1 NaOH and 3 % H2O2. No significant thermal or photolytic degradation was observed in solid drug. The method was applied successfully for the assay of olmesartan medoxomil in the tablet dosage form.U ovom radu razvijena je i validirana jednostavna, osjetljiva i precizna RP-HPLC-DAD metoda za odreÄivanje olmesartan medoksomila (inhibitor AT-II receptora) u prisutnosti njegovih razgradnih produkata. Olmesartan medoksomil i razgradni produkti kromatografirani su na C18 koloni uz mobilnu fazu metanol/ acetonitril/vo
da (60:15:25 V/V/V; pH 3,5 podeÅ”en ortofosfornom kiselinom) pri 260 nm uz detektor s fotodiodnim nizom. Metoda je linearna u koncentracijskom rasponu 1ā18 Āµg mL 1 i precizna s RSD < 1 % tijekom ispitivanja repetabilnosti i intermedijarne ponovljivosti. Povrat od 99,3 Ā± 0,9 do 100,8 Ā± 1,2 % dokazuje toÄnost metode. Razvijena metoda je specifiÄna na Å”to ukazuje kromatografsku rezoluciju veÄu od 2,0 i osjetljiva (LOD = 0,03 Āµg mLā1 i LOQ = 0,1 Āµg mLā1). Metoda je upotrebljena za praÄenje razgradnje olmesartan medoksomila u uvjetima potencirane razgradnje. U 0,1 mol Lā1 HCl detektirana su Äetiri razgradna produkta (DP-I, II, III, IV), a u vodi, 0,01 mol Lā1 NaOH i 3 % H2O2 samo DP-I, II i III. U Ävrstom agregatnom stanju nije primjeÄena znaÄajna termiÄka ni fotolitiÄka razgradnja ljekovite tvari. Metoda je uspjeÅ”no primijenjena za odreÄivanje olmesartan medoksomila u tabletama
Functional filter for whole genome sequencing data identifies HHT and stress-associated non-coding SMAD4 polyadenylation site variants >5kb from coding DN
Acknowledgments: This research was made possible through access to the data and findings generated by the 100,000 Genomes Project. The work was cofounded by the National Institute for Health Research Imperial Biomedical Research Centre, the DāAlmeida Charitable Trust, and Imperial College Healthcare NHS Trust. AA was supported by Prince Sultan Military Medical City, Saudi Arabia. MAA was supported by the National Institutes of Health (grant R35HL140019). The 100,000 Genomes Project is managed by Genomics England Limited (a wholly owned company of the Department of Health and Social Care). The 100,000 Genomes Project uses data provided by patients and collected by the National Health Service as part of their care and support. We thank the National Health Service staff of the UK Genomic Medicine Centres and the participants for their willing participation; the Genomics England Clinical Research Interface team, specifically Susan Walker, for separately reviewing bam file variant sequences; Charlotte Bevan, Michael Hubank and Santiago Vernia for helpful discussions and manuscript review; and our academic and public partners within the NIHR Imperial BRCās Social Genetic and Environmental Determinants of Health (SGE) theme. We specifically thank the presented families for confirmation of their clinical phenotypes and consent to share in this manuscript. The views expressed are those of the authors and not necessarily those of funders, the NHS, the NIHR, or the Department of Health and Social Care.Peer reviewedPublisher PD
Maturing Thalamocortical Functional Connectivity Across Development
Recent years have witnessed a surge of investigations examining functional brain organization using resting-state functional connectivity MRI (rs-fcMRI). To date, this method has been used to examine systems organization in typical and atypical developing populations. While the majority of these investigations have focused on corticalācortical interactions, corticalāsubcortical interactions also mature into adulthood. Innovative work by Zhang et al. (2008) in adults have identified methods that utilize rs-fcMRI and known thalamo-cortical topographic segregation to identify functional boundaries in the thalamus that are remarkably similar to known thalamic nuclear grouping. However, despite thalamic nuclei being well formed early in development, the developmental trajectory of functional thalamo-cortical relations remains unexplored. Thalamic maps generated by rs-fcMRI are based on functional relationships, and should modify with the dynamic thalamo-cortical changes that occur throughout maturation. To examine this possibility, we employed a strategy as previously described by Zhang et al. to a sample of healthy children, adolescents, and adults. We found strengthening functional connectivity of the cortex with dorsal/anterior subdivisions of the thalamus, with greater connectivity observed in adults versus children. Temporal lobe connectivity with ventral/midline/posterior subdivisions of the thalamus weakened with age. Changes in sensory and motor thalamo-cortical interactions were also identified but were limited. These findings are consistent with known anatomical and physiological corticalāsubcortical changes over development. The methods and developmental context provided here will be important for understanding how corticalāsubcortical interactions relate to models of typically developing behavior and developmental neuropsychiatric disorders
Preparation of flexible dielectric nanocomposites using nanocellulose and recycled alum sludge for wearable technology applications
With the rapid development of wearable technology, flexible dielectric materials with environmental-friendly, low-cost and high-energy efficiency characteristics are in increasing demand. In this work, a flexible dielectric nanocomposite was developed by incorporating two components: cellulose nanofibrils (CNF) and recycled alum sludge, as the reinforcement phase and for enhancing the dielectric properties, in a bio-elastomer matrix. CNF and alum sludge were processed from waste materials which would otherwise be disposed to landfills. CNF were derived from water hyacinth, an invasive aquatic weed. Dried water hyacinth was treated using a simple and less energy-intensive process to obtain CNF. The alum sludge raw material was collected from a water treatment plant of Scottish Water and heat treated and refined before being used in preparing the composites. A biodegradable elastomer polydimethylsiloxane was used as the matrix and the nanocomposites were processed by casting the materials in petri dishes. The processed composites were characterised using scanning electron microscopy (SEM), thermogravimetric (TGA/DTG) and X-ray diffraction (XRD) analysis. The SEM micrographs illustrated CNF of approximately 20nm in diameter and alum sludge particles of approximately 200um in size. The TGA/DTG analysis results showed that a total mass of 46% has been removed when the sludge sample was heated up to 900Ā°C. The XRD result showed that both quartz SiO2 and cubic Ī³-Al2O3 structures can be found in the sample that was heat treated up to 800Ā°C. Other experiments also showed that the composites exhibit comparable mechanical and dielectric performances with other works in the literature. The work depicts that it is a sustainable practice of reusing such wastes in preparing flexible, lightweight and miniature dielectric materials that can be used for wearable technology applications
RP-LC and HPTLC Methods for the Determination of Olmesartan Medoxomil and Hydrochlorothiazide in Combined Tablet Dosage Forms
Two new, rapid, precise, accurate and specific chromatographic methods were described for the simultaneous determination of olmesartan medoxomil and hydrochlorothiazide in combined tablet dosage forms. The first method was based on reversed phase liquid chromatography using an Eurosphere 100 RP C18 column (250Ā ĆĀ 4.6Ā mm ID, 5Ā Ī¼m). The mobile phase was methanolā0.05% o-phosphoric acid (60:40 v/v) at a flow rate of 1.0Ā mLĀ minā1. Commercially available tablets and laboratory mixtures containing both drugs were assayed and detected using a UV detector at 270Ā nm. The second method involved silica gel 60 F254 high performance thin layer chromatography and densitometric detection at 254Ā nm using acetonitrileāethyl acetateāglacial acid (7:3:0.4 v/v/v) as the mobile phase. Calibration curves ranged between 200ā600 and 125ā375Ā ng spotā1 for olmesartan and hydrochlorothiazide, respectively
Spatiotemporal epidemic characteristics and risk factor analysis of malaria in Yunnan Province, China
Bacterial endosymbiont Cardinium cSfur genome sequence provides insights for understanding the symbiotic relationship in Sogatella furcifera host
Background: Sogatella furcifera is a migratory pest that damages rice plants and causes severe economic losses. Due to its ability to annually migrate long distances, S.furcifera has emerged as a major pest of rice in several Asian countries. Symbiotic relationships of inherited bacteria with terrestrial arthropods have significant implications. The genus Cardinium is present in many types of arthropods, where it influences some host characteristics. We present a report of a newly # identified strain of the bacterial endosymbiont Cardinium cSfur in S. furcifera.
Result: From the whole genome of S. furcifera previously sequenced by our laboratory, we assembled the whole genome sequence of Cardinium cSfur. The sequence comprised 1,103,593 bp with a GC content of 39.2%. The phylogenetic tree of the Bacteroides phylum to which Cardinium cSfur belongs suggests that Cardinium cSfur is closely related to the other strains (Cardinium cBtQ1 and cEper1) that are members of the Amoebophilaceae family. Genome comparison between the host-dependent endosymbiont including Cardinium cSfur and freeliving bacteria revealed that the endosymbiont has a smaller genome size and lower GC content, and has lost some genes related to metabolism because of its special environment, which is similar to the genome pattern observed in other insect symbionts. Cardinium cSfur has limited metabolic capability, which makes it less contributive to metabolic and biosynthetic processes in its host. From our findings, we inferred that, to compensate for its limited metabolic capability, Cardinium cSfur harbors a relatively high proportion of transport proteins, which might act as the hub between it and its host. With its acquisition of the whole operon related to biotin synthesis and glycolysis related genes through HGT event, Cardinium cSfur seems to be undergoing changes while establishing a symbiotic relationship with its host.
Conclusion: A novel bacterial endosymbiont strain (Cardinium cSfur) has been discovered. A genomic analysis of the endosymbiont in S. furcifera suggests that its genome has undergone certain changes to facilitate its settlement in the host. The envisaged potential reproduction manipulative ability of the new endosymbiont strain in its S. furcifera host has vital implications in designing eco-friendly approaches to combat the insect pest
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