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Sökning: WFRF:(Koo S)

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  • Wang, Li-San, et al. (författare)
  • Rarity of the Alzheimer Disease-Protective APP A673T Variant in the United States.
  • 2015
  • Ingår i: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 72:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Recently, a rare variant in the amyloid precursor protein gene (APP) was described in a population from Iceland. This variant, in which alanine is replaced by threonine at position 673 (A673T), appears to protect against late-onset Alzheimer disease (AD). We evaluated the frequency of this variant in AD cases and cognitively normal controls to determine whether this variant will significantly contribute to risk assessment in individuals in the United States.
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  • Milham, Michael P., et al. (författare)
  • An Open Resource for Non-human Primate Imaging
  • 2018
  • Ingår i: Neuron. - : Elsevier BV. - 0896-6273 .- 1097-4199. ; 100:1, s. 61-74
  • Tidskriftsartikel (refereegranskat)abstract
    • Non-human primate neuroimaging is a rapidly growing area of research that promises to transform and scale translational and cross-species comparative neuroscience. Unfortunately, the technological and methodological advances of the past two decades have outpaced the accrual of data, which is particularly challenging given the relatively few centers that have the necessary facilities and capabilities. The PRIMatE Data Exchange (PRIME-DE) addresses this challenge by aggregating independently acquired non-human primate magnetic resonance imaging (MRI) datasets and openly sharing them via the International Neuroimaging Data-sharing Initiative (INDI). Here, we present the rationale, design, and procedures for the PRIME-DE consortium, as well as the initial release, consisting of 25 independent data collections aggregated across 22 sites (total = 217 non-human primates). We also outline the unique pitfalls and challenges that should be considered in the analysis of non-human primate MRI datasets, including providing automated quality assessment of the contributed datasets.
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  • Yu, K-H, et al. (författare)
  • Comparison of 90-day case-fatality after ischemic stroke between two different stroke outcome registries using propensity score matching analysis
  • 2011
  • Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 123:5, s. 325-331
  • Tidskriftsartikel (refereegranskat)abstract
    • Background - It has not been clarified whether the disparity in ischemic stroke outcome between populations is caused by ethnic and geographic differences or by variations in case mix. Propensity score matching (PSM) analysis can overcome some analytical problems but is rarely used in stroke outcome research. This study was to compare the ischemic stroke case-fatality between two PSM cohorts of Sweden and Korea. Methods - Prognostic variables related to baseline characteristics and stroke care were included in our PSM model. Then, we selected 7675 Swedish and 1220 Korean patients with ischemic stroke from each stroke registers and performed one-to-one matching based on propensity scores of each patient. Results - After PSM, all measured variables were well balanced in 1163 matched subjects, and the 90-day case-fatality was identical 6.2% (HR 0.997, 95%CI 0.905-1.099) in Sweden and Korea. Conclusions - No difference is found in the 90-day case-fatality in propensity score-matched Swedish and Korean patients with ischemic stroke.
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  • Escaned, Javier, et al. (författare)
  • Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes
  • 2018
  • Ingår i: JACC. - : Elsevier. - 1936-8798 .- 1876-7605. ; 11:15, s. 1437-1449
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVES The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS). BACKGROUND Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization. METHODS The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. RESULTS Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p < 0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04). CONCLUSIONS Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year. (C) 2018 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.
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10.
  • Pattabiraman, M., et al. (författare)
  • Annealing effect on transport properties of Nd0.67Sr0.33MnO3 thin films
  • 2000
  • Ingår i: Pramana (Bangalore). - : Springer Science and Business Media LLC. - 0304-4289 .- 0973-7111. ; 55:3, s. 455-469
  • Tidskriftsartikel (refereegranskat)abstract
    • Annealing dependence of the lattice parameter, resistivity, magnetoresistance and thermopower have been studied on Nd0.87Sr0.33MnO3 thin films deposited on LaAlO3 and alumina substrates by pulsed laser ablation. Upon annealing at 800 degrees C and 1000 degrees C the lattice constant of the LaAlO3 film tends toward that of the bulk target due to reduction in oxygen vacancies. This results in a metal-insulator transition at temperatures which increase with progressive annealing along with a decrease in the observed low temperature MR. Using a magnon scattering model we estimate the e(g) bandwidth of the film annealed at 1000 degrees C and show that the magnon contribution to the resistivity is suppressed in a highly oxygen deficient film and gains prominence only upon subsequent annealing. We also show that upon annealing, the polaron concentration and the spin cluster size increases in the paramagnetic phase, using an adiabatic polaron hopping model which takes into account an exchange dependent activation energy above the resistivity peak.
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11.
  • Schilling, S., et al. (författare)
  • Differential effects of familial Alzheimer's disease-causing mutations on amyloid precursor protein (APP) trafficking, proteolytic conversion, and synaptogenic activity
  • 2023
  • Ingår i: Acta Neuropathologica Communications. - 2051-5960. ; 11:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The amyloid precursor protein (APP) is a key player in Alzheimer`s disease (AD) and the precursor of the A beta peptide, which is generated by consecutive cleavages of beta- and gamma-secretases. Familial Alzheimer's disease (FAD) describes a hereditary subgroup of AD that represents a low percentage of AD cases with an early onset of the disease. Different APP FAD mutations are thought to have qualitatively different effects on its proteolytic conversion. However, few studies have explored the pathogenic and putative physiological differences in more detail. Here, we compared different FAD mutations, located at the beta- (Swedish), alpha- (Flemish, Arctic, Iowa) or gamma-secretase (Iberian) cleavage sites. We examined heterologous expression of APP WT and FAD mutants in non-neuronal cells and their impact on presynaptic differentiation in contacting axons of co-cultured neurons. To decipher the underlying molecular mechanism, we tested the subcellular localization, the endocytosis rate and the proteolytic processing in detail by immunoprecipitation-mass spectrometry. Interestingly, we found that only the Iberian mutation showed altered synaptogenic function. Furthermore, the APP Iowa mutant shows significantly decreased alpha-secretase processing which is in line with our results that APP carrying the Iowa mutation was significantly increased in early endosomes. However, most interestingly, immunoprecipitation-mass spectrometry analysis revealed that the amino acid substitutions of APP FAD mutants have a decisive impact on their processing reflected in altered A beta profiles. Importantly, N-terminally truncated A beta peptides starting at position 5 were detected preferentially for APP Flemish, Arctic, and Iowa mutants containing amino acid substitutions around the alpha-secretase cleavage site. The strongest change in the ratio of A beta 40/A beta 42 was observed for the Iberian mutation while APP Swedish showed a substantial increase in A beta 1-17 peptides. Together, our data indicate that familial AD mutations located at the alpha-, beta-, and gamma-secretase cleavage sites show considerable differences in the underlying pathogenic mechanisms.
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  • Zetterling, Carl-Mikael, et al. (författare)
  • Challenges for High Temperature Silicon Carbide Electronics
  • 2003
  • Ingår i: Materials Research Society Symposium - Proceedings. - San Francisco, CA. ; , s. 15-25
  • Konferensbidrag (refereegranskat)abstract
    • Silicon carbide has been proposed as an excellent material for high-frequency, high-power and high-temperature electronics. High power and high frequency applications have been pursued for quite some time in SiC with a great deal of success in terms of demonstrated devices. However, self-heating problems due to the much higher power densities that result when ten times higher electrical fields are used inside the devices needs to be addressed. High-temperature electronics has not yet experienced as much attention and success, possibly because there is no immediate market. This paper will review some of the advances that have been made in high-temperature electronics using silicon carbide, starting from process technology, continuing with device design, and finishing with circuit examples. For process technology, one of the biggest obstacles is long-term stable contacts. Several device structures have been electrically characterized at high temperature (BJTs and FETs) and will be compared to surface temperature measurements and physical device simulation. Finally some proposed circuit topologies as well as novel solutions will be presented.
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  • Berglundh, Tord, 1954, et al. (författare)
  • Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions
  • 2018
  • Ingår i: Journal of Periodontology. - : Wiley. - 0022-3492. ; 89
  • Tidskriftsartikel (refereegranskat)abstract
    • A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis.
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  • Davies, Neil, et al. (författare)
  • The founding charter of the Genomic Observatories Network
  • 2014
  • Ingår i: GigaScience. - 2047-217X. ; 3:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Abstract The co-authors of this paper hereby state their intention to work together to launch the Genomic Observatories Network (GOs Network) for which this document will serve as its Founding Charter. We define a Genomic Observatory as an ecosystem and/or site subject to long-term scientific research, including (but not limited to) the sustained study of genomic biodiversity from single-celled microbes to multicellular organisms.An international group of 64 scientists first published the call for a global network of Genomic Observatories in January 2012. The vision for such a network was expanded in a subsequent paper and developed over a series of meetings in Bremen (Germany), Shenzhen (China), Moorea (French Polynesia), Oxford (UK), Pacific Grove (California, USA), Washington (DC, USA), and London (UK). While this community-building process continues, here we express our mutual intent to establish the GOs Network formally, and to describe our shared vision for its future. The views expressed here are ours alone as individual scientists, and do not necessarily represent those of the institutions with which we are affiliated.
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  • Enejder, Annika, 1969, et al. (författare)
  • Blood analysis by Raman spectroscopy
  • 2002
  • Ingår i: Optics Letters. - : The Optical Society. - 0146-9592 .- 1539-4794. ; 27:22, s. 2004-2006
  • Tidskriftsartikel (refereegranskat)
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  • Kang, M. -S, et al. (författare)
  • Metal work-function and doping-concentration dependent barrier height of Ni-contacts to 4H-SiC with metal-embedded nano-particles
  • 2012
  • Ingår i: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. - 9783037854198 ; 717-720, s. 857-860
  • Tidskriftsartikel (refereegranskat)abstract
    • We investigated the effect of the metal work-function and doping concentration on the barrier height of Ni-contacts with embedded nano-particles (NPs) on 4H-SiC surfaces. Both n-type epitaxial layers with N-D=1x10(16) cm(-3), and layers doped by phosphorus implantation to a doping concentration of similar to 1x10(19) cm(-3) are used. The barrier height is reduced with increasing doping concentration and the silver (Ag) nano-particles (R similar to 18.5 nm) further enhance the local electric field of the electrical contacts to 4H-SiC in comparison to gold (Au) nano-particles (R similar to 20.2 nm). In the case of ion-implanted samples, the barrier height of the fabricated SiC diode structures with embedded Ag-NPs was significantly reduced by similar to 0.09 eV and similar to 0.25 eV compared to the samples with Au-NPs and the sample without NPs, respectively.
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  • Koo, S. M., et al. (författare)
  • Combination of JFET and MOSFET devices in 4H-SiC for high-temperature stable circuit operation
  • 2003
  • Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 39:12, s. 933-935
  • Tidskriftsartikel (refereegranskat)abstract
    • A novel combination of junction-gated and metal-oxide-semiconductor field effect transistor (JMOSFET) has been fabricated and characterised in 4H-SiC. The high-temperature stable operation of JMOSFETs has been explored in terms of constant current levels. The JMOSFETs have shown the feasibility for operating with constant on and off current levels from room temperature up to 300degreesC. Another advantage of this device is the improved current density by accumulation of the MOS n-channel.
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23.
  • Koo, S. M., et al. (författare)
  • Electrical characteristics of metal-oxide-semiconductor capacitors on plasma etch-damaged silicon carbide
  • 2002
  • Ingår i: Solid-State Electronics. - 0038-1101 .- 1879-2405. ; 46:9, s. 1375-1380
  • Tidskriftsartikel (refereegranskat)abstract
    • The characteristics of metal-oxide-semiconductor (MOS) capacitors formed on inductively coupled plasma (ICP) etch-damaged SiC have been investigated. MOS capacitors were prepared by dry-oxidation on ICP-etch-damaged n- and p-type. 6H- and 4H-SiC. The effect of a sacrificial oxidation treatment on the damaged surfaces has also been examined. Capacitance-voltage and current-voltage measurements of these capacitors were performed and referenced to those of simultaneously prepared control samples without etch damage. The effective interface densities (N-IT) and fixed oxide charges (Q(V)) of etch-damaged samples have been found to increase while the breakdown field strength (E-BD) of the oxide decreases. The barrier height (phib) at the SiC-SiO2, interface, determined from a Fowler-Nordheim analysis, decreased for MOS capacitors on etch-damaged surfaces. It has been found that a sacrificial oxidation treatment can improve the electrical characteristics of MOS capacitors on etch-damaged SiC.
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24.
  • Koo, S. -M, et al. (författare)
  • Influence of trenching effect on the characteristics of buried-gate SiC junction field-effect transistors
  • 2002
  • Ingår i: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. ; 389-393:2, s. 1235-1238
  • Tidskriftsartikel (refereegranskat)abstract
    • Two different structures of junction field-effect transistors in 4H-SiC, with and without trenching effect in the channel region, have been fabricated and characterized. The devices formed with metal mask show a trenching profile (>∌0.2 ÎŒm) after dry etch in the channel groove region and exhibited static induction transistor (SIT)-like characteristics in the sub-threshold region of I-V curves as the channel thickness decreases. The devices without trenching effect have been processed by using a wet-etched oxide mask resulting in a sloped dry-etch profile (Ξ=∌30°) in the channel, and consequently showed well-saturated drain characteristics for all the channel thicknesses. The conduction mechanisms in these JFETs are examined by the potential profiles from two dimensional numerical simulations.
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  • Koo, S. -M, et al. (författare)
  • Towards ferroelectric field effect transistors in 4H-silicon carbide
  • 2002
  • Ingår i: Materials Research Society Symposium - Proceedings. - Boston, MA. ; , s. 371-379
  • Konferensbidrag (refereegranskat)abstract
    • We report on the integration of ferroelectric Pb(Zr,Ti)O3 (PZT) thin films on 4H-silicon carbide and their electrical properties. The structures of metal-ferroelectric-(insulator)-semiconductor MF(I)S and metal-ferroelectric-metal-insulator-semiconductor MFMIS have been fabricated and characterized. The MFMIS structures of Au/PZT/Pt/Ti/SiO2/SiC have shown fully saturated P-E hysteresis loops with remnant polarization Pr = 14.2 ÎŒC/cm2 and coercive field Ec = 58.9 kV/cm. The MFIS structures exhibited stable capacitance-voltage C-V loops with low conductance (<0.1 mS/cm2, tan ÎŽ ∌ 0.0007 at 12 V, 400 kHz) and memory window as wide as 10 V, when a 5 nm-thick Al2O3 was used as a high bandgap (Eg ∌ 9 eV) barrier buffer layer between PZT (Eg ∌ 3.5 eV) and SiC (Eg ∌ 3.2 eV). Both structures on n- and p- SiC have shown electrical properties promising for the application to the gate stacks for the SiC field-effect transistors (FETs) and the design and process issues on different types of the metal-ferroelectric-silicon carbide field-effect transistors (FETs) have also been proposed.
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  • Lee, S. K., et al. (författare)
  • Ohmic contact formation on inductively coupled plasma etched 4H-silicon carbide
  • 2002
  • Ingår i: Journal of Electronic Materials. - : Springer Science and Business Media LLC. - 0361-5235 .- 1543-186X. ; 31:5, s. 340-345
  • Tidskriftsartikel (refereegranskat)abstract
    • We report on the investigation of ohmic contact formation using sputtered titanium-tungsten contacts on an inductively coupled plasma (ICP) etch-damaged 4H-SiC surface. Transfer length method (TLM) measurements were performed to characterize how ICP-etch damage affects the performance of ohmic contacts to silicon carbide. In order to recover etch damage, high-temperature oxidation (1250degreesC for 1 h) was evaluated for one of the samples. Some of the etch damage was recovered, but it did not fully recover the etch damage for the sample etched with medium platen power (60 W). From our TLM measurements, the specific contact resistance (rho(C) of sputtered titanium tungsten on highly doped n(+)-type 4H-SiC epilayers with a doping of 1.1 X 10(19) cm(-3) for the unetched reference sample, 30-W etched, and 60-W etched with and without sacrificial oxidation was as low as 3.8 X 10(-5) Omegacm(2), 3.3 X 10(-5) Omega cm(2), 2.3 X 10(-4) Omegacm(2), and 1.3 X 10(-3) Omegacm(2), respectively. We found that the low-power (30 W) ICP-etching process did not affect the formation of ohmic contacts, and we did not observe any difference between the unetched and the 30-W etched sample from our TLM measurements, having the same value of the rho(C). However, medium-platen-power (60 W) ICP etching showed significant influence on the ohmic contact formation. We found that the specific contact resistance is highly related to the surface roughness and quality of the metals, and the lower, specific contact resistance is due to the smoother and denser ohmic contacts.
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30.
  • Mazei-Robison, Michelle S., et al. (författare)
  • Role for mTOR Signaling and Neuronal Activity in Morphine-Induced Adaptations in Ventral Tegmental Area Dopamine Neurons
  • 2011
  • Ingår i: Neuron. - : Elsevier BV. - 0896-6273 .- 1097-4199. ; 72:6, s. 977-990
  • Tidskriftsartikel (refereegranskat)abstract
    • While the abuse of opiate drugs continues to rise, the neuroadaptations that occur with long-term drug exposure remain poorly understood. We describe here a series of chronic morphine-induced adaptations in ventral tegmental area (VTA) dopamine neurons, which are mediated via downregulation of AKT-mTORC2 (mammalian target of rapamycin complex-2). Chronic opiates decrease the size of VTA dopamine neurons in rodents, an effect seen in humans as well, and concomitantly increase the excitability of the cells but decrease dopamine output to target regions. Chronic morphine decreases mTORC2 activity, and overexpression of Rictor, a component of mTORC2, prevents morphine-induced changes in cell morphology and activity. Further, local knockout of Rictor in VTA decreases DA soma size and reduces rewarding responses to morphine, consistent with the hypothesis that these adaptations represent a mechanism of reward tolerance. Together, these findings demonstrate a novel role for AKT-mTORC2 signaling in mediating neuroadaptations to opiate drugs of abuse.
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31.
  • Nene, Vishvanath, et al. (författare)
  • Genome sequence of Aedes aegypti, a major arbovirus vector.
  • 2007
  • Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 316:5832, s. 1718-23
  • Tidskriftsartikel (refereegranskat)abstract
    • We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species.
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32.
  • Oh, Juhwan, et al. (författare)
  • Mobility restrictions were associated with reductions in COVID-19 incidence early in the pandemic : evidence from a real-time evaluation in 34 countries
  • 2021
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Most countries have implemented restrictions on mobility to prevent the spread of Coronavirus disease-19 (COVID-19), entailing considerable societal costs but, at least initially, based on limited evidence of effectiveness. We asked whether mobility restrictions were associated with changes in the occurrence of COVID-19 in 34 OECD countries plus Singapore and Taiwan. Our data sources were the Google Global Mobility Data Source, which reports different types of mobility, and COVID-19 cases retrieved from the dataset curated by Our World in Data. Beginning at each country's 100th case, and incorporating a 14-day lag to account for the delay between exposure and illness, we examined the association between changes in mobility (with January 3 to February 6, 2020 as baseline) and the ratio of the number of newly confirmed cases on a given day to the total number of cases over the past 14 days from the index day (the potentially infective 'pool' in that population), per million population, using LOESS regression and logit regression. In two-thirds of examined countries, reductions of up to 40% in commuting mobility (to workplaces, transit stations, retailers, and recreation) were associated with decreased cases, especially early in the pandemic. Once both mobility and incidence had been brought down, further restrictions provided little additional benefit. These findings point to the importance of acting early and decisively in a pandemic.
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35.
  • Aryapratama, Rio, et al. (författare)
  • Performance evaluation of hollow fiber air gap membrane distillation module with multiple cooling channels
  • 2016
  • Ingår i: Desalination. - : Elsevier BV. - 0011-9164. ; 385, s. 58-68
  • Tidskriftsartikel (refereegranskat)abstract
    • The hollow fiber air gap membrane distillation (AGMD) module equipped with the multiple cooling channels network made of stainless steel was developed. The performance of the developed AGMD module was evaluated by conducting several experiments, including the effect of feed temperature and flow rate, ratio of membrane surface area to condensation surface area, membrane packing position, comparison with hollow fiber DCMD, and the effect of inner and outer module channels to process performance. Moreover, theoretical model was suggested for the multiple cooling channels module. This study reveals that the produced flux and thermal efficiency of this module were up to 12.5 kg/m2 h and 81.7%, respectively, which is higher than most of previous studies that used polymeric fibers as coolant channels. Furthermore, the optimum ratio of membrane area to condensation surface area to produce optimum flux and thermal efficiency is known to be around 0.55. Further experimental results show that the outer channel has significant contribution in reducing the amount of heat loss. This is also could be the reason why the average flux of hollow fiber AGMD module was only 22% lower, while the average thermal efficiency is 58% higher than that of hollow fiber DCMD module.
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36.
  • Berglundh, Tord, 1954, et al. (författare)
  • Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions
  • 2018
  • Ingår i: J Clin Periodontol. - : Wiley. - 0303-6979 .- 1600-051X. ; 45
  • Tidskriftsartikel (refereegranskat)abstract
    • A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis.
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39.
  • Choi, Y. W., et al. (författare)
  • Ordered Phases in Fe-Si Alloys : A First-Principles Study
  • 2018
  • Ingår i: Journal of the Korean Physical Society. - : The Korean Physical Society. - 0374-4884 .- 1976-8524. ; 72:6, s. 737-740
  • Tidskriftsartikel (refereegranskat)abstract
    • It is known that the formation of ordered phases causes the brittleness of electrical steels. We employed first-principles method in order to examine the possibility of the ordered-phases formation in Fe-Si alloys. It is found that the D03-like ordered configuration is most stable among other atomic configurations in the ferromagnetic state. In the paramagnetic state, for low Si concentration, the stability of the ordered configurations is comparable to that of disordered ones. However, as Si content increases, the B2 ordered phase as well as the D03 phase becomes more stable than the disordered ones. 
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40.
  • Granville, S, et al. (författare)
  • Optical conductivity and x-ray absorption and emission study of the band structure of MnN films
  • 2005
  • Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 72:20, s. 205127-
  • Tidskriftsartikel (refereegranskat)abstract
    • The band structure of MnN films prepared by ion assisted deposition has been investigated by optical conductivity and x-ray absorption and emission spectroscopies. X-ray diffraction and extended x-ray absorption fine structure show the films to be nanocrystalline but phase pure and exhibiting the known antiferromagnetic distorted rocksalt phase. X-ray emission spectroscopy of the N K-edge and x-ray absorption near edge spectroscopy of both the N K- and Mn L-edges are used to probe the occupied and empty densities of states, which compare well with the N(2p) and Mn(3d) partial densities of states calculated using the linearized muffin-tin orbital band structure method. A similar comparison is made between the measured optical conductivity and the calculated contribution from interband transitions. It is possible to associate the main features in the measured spectrum with corresponding ones in the calculated optical function. The major differences between calculated and measured spectra can be understood on the basis of a limited electron mean-free-path in these nanocrystalline films, which broadens the features in the joint density of states and relaxes the momentum conservation requirement. The calculated optical functions are analyzed in detail in terms of their dominant band-to-band contributions and in addition the polarization dependence is predicted. Temperature dependent conductivity measurements are also reported and show a clear metallic behavior and a weak Kondo-like low temperature anomaly.
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41.
  • Kim, Dae-Kyum, et al. (författare)
  • EVpedia: A Community Web Portal for Extracellular Vesicles Research
  • 2015
  • Ingår i: Bioinformatics. - : Oxford University Press (OUP). - 1367-4803 .- 1367-4811. ; 31:6, s. 933-939
  • Tidskriftsartikel (refereegranskat)abstract
    • Motivation: Extracellular vesicles (EVs) are spherical bilayered proteolipids, harboring various bioactive molecules. Due to the complexity of the vesicular nomenclatures and components, online searches for EV-related publications and vesicular components are currently challenging. Results: We present an improved version of EVpedia, a public database for EVs research. This community web portal contains a database of publications and vesicular components, identification of orthologous vesicular components, bioinformatic tools and a personalized function. EVpedia includes 6879 publications, 172 080 vesicular components from 263 high-throughput datasets, and has been accessed more than 65 000 times from more than 750 cities. In addition, about 350 members from 73 international research groups have participated in developing EVpedia. This free web-based database might serve as a useful resource to stimulate the emerging field of EV research.
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42.
  • Kim, Se-Hoon, et al. (författare)
  • Nanophase oxalate precursors of thermoelectric CoSb3 by controlled coprecipitation predicted by thermodynamic modeling
  • 2016
  • Ingår i: Advanced Powder Technology. - : Elsevier. - 0921-8831 .- 1568-5527. ; 27:2, s. 773-778
  • Tidskriftsartikel (refereegranskat)abstract
    • The precursors for the formation of thermoelectric skutterudite CoSb3 nanoparticles are predicted by thermodynamic modeling of the complex chemical species. Based on the results, equimolar mixture of CoC2O4 center dot 2H(2)O and Sb(C2O4) OH are successively co-precipitated under controlled conditions of pH = 2.7 and concentration of reactants. The as synthesized powder was decomposed at 350 degrees C to remove the organic molecules and further reduced to CoSb3 phase by heating at 530 degrees C under hydrogen flow. The obtained powder was consolidated by spark plasma sintering (SPS). CoSb3 prepared by controlled chemical co-precipitation has p-type behavior with a positive sign of the Seebeck coefficient. TE transport properties were measured, which revealed that the Seebeck coefficient increased 2.5 times with increasing the temperature and it is lower than the ball milled CoSb3. Thermal conductivity of sintered CoSb3 at 773 K starts from 0.06 W/cm K at room temperature and decreases to 0.04 W/cm K at 700 K, which is lower than the bulk counterpart. The ZT of coprecipitated CoSb3 and SPS consolidated at 773 K shows 2 times higher than the ball milled one. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.
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43.
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44.
  • Koo, S. M., et al. (författare)
  • Ferroelectric Pb(Zr,Ti)O-3/Al2O3/4H-SiC diode structures
  • 2002
  • Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 81:5, s. 895-897
  • Tidskriftsartikel (refereegranskat)abstract
    • Pb(Zr,Ti)O-3 (PZT) films (450 nm thick) were grown on 4H-silicon carbide (SiC) substrates by a pulsed-laser deposition technique. X-ray diffraction confirms single PZT phase without a preferred orientation. Stable capacitance-voltage (C-V) loops with low conductance (<0.1 mS/cm(2), tan deltasimilar to0.0007 at 400 kHz) and memory window as wide as 10 V were obtained when 5-nm-thick Al2O3 was used as a high band gap (E(g)similar to9 eV) barrier buffer layer between PZT (E(g)similar to3.5 eV) and SiC (E(g)similar to3.2 eV). High-frequency (400 kHz) C-V characteristics revealed clear accumulation, and depletion behavior. Although the charge injection from SiC is the dominant mechanism for C-V hysteresis in PZT/Al2O3/SiC, negligible sweep rate dependence and negligible applied bias dependence were observed compared to that of PZT/SiC. By using room-temperature photoilluminated C-V measurements, the interface states as well as the charge trapping in the PZT/Al2O3 stacks have been calculated.
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45.
  • Koo, S. M., et al. (författare)
  • Ferroelectric Pb(Zr0.52Ti0.48)/SiC field-effect transistor
  • 2003
  • Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 83:19, s. 3975-3977
  • Tidskriftsartikel (refereegranskat)abstract
    • Nonvolatile operation of ferroelectric gate field-effect transistors in silicon carbide (SiC) is demonstrated. Depletion mode transistors have been realized by forming a Pb(Zr0.52Ti0.48)O-3/Al2O3 gate stack on n-type epitaxial channel layer and p-type substrate of 4H-SiC. A memory window, as wide as 5 V, has been observed in the drain current and the ferroelectric gate voltage transfer characteristics. The transistor showed memory effect from room temperature up to 200 degreesC, whereas stable transistor operation was observed up to 300 degreesC. The retention of remnant polarization was preserved after 2x10(4) s at 150 degreesC with no bias on the gate.
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46.
  • Koo, S. M., et al. (författare)
  • Processing and properties of ferroelectric Pb(Zr,Ti)O-3/silicon carbide field-effect transistor
  • 2003
  • Ingår i: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 57, s. 1221-1231
  • Tidskriftsartikel (refereegranskat)abstract
    • Metal-ferroelectric-(insulator)-semiconductor MF(I)S structures have been fabricated and the properties of pulsed laser-deposited PZT/Al-2 O-3 gate stacks have been studied on n - and p -type 4H-SiC. Among several polytypes of SiC, 4H-SiC is considered as the most attractive one because of its wider bandgap (E-g congruent to 3.2 eV) as well as higher and more isotropic bulk mobility than other polytypes. Single PZT phase without a preferred orientation was confirmed by x-ray diffraction. The interface trap densities N-IT , fixed oxide charges Q(F) , and trapped oxide charges Q HY have been estimated by C-V curves with and without photo-illuminated measurements at room temperature. It is found that the charge injection from SiC is the dominant mechanism for C-V hysteresis. Importantly, with PZT/Al-2 O-3 gate stacks, superior C-V characteristics with negligible sweep rate dependence and negligible time dependence under the applied bias were obtained compared to PZT directly deposited on SiC. The MFIS structures exhibited very stable capacitance-voltage C-V loops with low conductance (<0.1 mS/cm(2) , tan delta similar to 0.0007 at 400 kHz) and memory window as wide as 10 V, when 5 nm-thick Al2O3 was used as a high bandgap (E-g similar to 9 eV) barrier buffer layer between PZT (E-g similar to 3.5 eV) and SiC (E-g similar to 3.2 eV). The structures have shown excellent electrical properties promising for the gate stacks as the SiC field-effect transistors (FETs). Depletion mode transistors were prepared by forming a Pb(Zr-0.52 Ti-0.48 )O-3 /Al-2 O-3 gate stack on 4H-SiC. Based on this structure, ferroelectric Pb(Zr,Ti)O-3 (PZT) thin films have been integrated on 4H-silicon carbide (SiC) in a SiC field-effect transistor process. Nonvolatile operation of ferroelectric-gate field-effect transistors in silicon carbide (SiC) is demonstrated.
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47.
  • Koo, S. -M, et al. (författare)
  • Simulation and Measurement of Switching Characteristics of 4H-SiC Buried-Gate JFETs
  • 2003
  • Ingår i: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. ; 433-436, s. 773-776
  • Tidskriftsartikel (refereegranskat)abstract
    • Buried-gate junction field-effect transistors (JFETs) have been fabricated in 4H polytype silicon carbide (SiC). The dynamic switching characteristics of the JFETs in a circuit with inductive load have been characterized. The drain voltage rise/fall time of ∌30 ns and 25 ns have been observed for turn-off and turn-on, respectively. The results have been compared to numerical mixed-mode circuit simulations with finite element structures.
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48.
  • Larsson, Kjell, et al. (författare)
  • Treatment Patterns, Socioeconomic Status and Clinical Burden in Mild COPD : A Swedish Real-World, Retrospective Cohort Study, the ARCTIC Study
  • 2022
  • Ingår i: The International Journal of Chronic Obstructive Pulmonary Disease. - : Informa UK Limited. - 1176-9106 .- 1178-2005. ; 17, s. 1409-1421
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Patients with mild chronic obstructive pulmonary disease (COPD) account for more than half of the total COPD population but are often undiagnosed and sparsely studied. This real-world, longitudinal study compared the socioeconomic burden, clinical characteristics and treatment patterns in patients with mild COPD and age-and gender-matched controls. Patients and methods: Our population included mild COPD patients (forced expiratory volume in one second >= 80% of predicted value) and reference controls from 52 Swedish primary care centres over 15 years (2000-2014). We linked electronic medical record (EMR) data to Sweden's National Health Registries. The outcomes analyzed were socioeconomic status including annual income from work, presence of comorbidities and the use of medications. Results: 844 patients with mild COPD were included in this study and matched with 844 reference controls. Compared with the reference controls, mild COPD patients had a significantly lower annual income from work (mean difference, men: 12,559 euro and women: 7143 euro ) and were significantly less likely to be married or employed. The presence of comorbidities, including cardiovascular disease, anxiety and depression (only women) was significantly higher in mild COPD patients. The use of medications, such as proton pump inhibitors, antidepressants, central painkillers and sleep medications, was significantly higher in the mild COPD group. Conclusion: Mild COPD presents a considerable socioeconomic and clinical burden compared with reference controls The findings suggest that COPD constitutes a condition that influences health status even in mild disease clearly demanding an increased need for early detection and treatment.
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49.
  • Lee, J. -H, et al. (författare)
  • Local anodic oxidation of phosphorus-implanted 4H-SiC by atomic force microscopy
  • 2012
  • Ingår i: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. - 9783037854198 ; 717-720, s. 905-908
  • Tidskriftsartikel (refereegranskat)abstract
    • In this work, local oxidation behavior in phosphorus ion-implanted 4H-SiC has been investigated by using atomic force microscopy (AFM). The AFM-local oxidation (LO) has been performed on the implanted samples, with and without activation anneal, using varying applied bias (15/20/25 V). It has been clearly shown that the post-implantation annealing process at 1650 °C has a great impact on the local oxidation rate by electrically activating the dopants and by modulating the surface roughness. In addition, the composition of resulting oxides changes depending on the doping level of SiC surfaces.
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50.
  • Lee, Jong-Koo, et al. (författare)
  • Institutional and behaviour-change interventions to support COVID-19 public health measures : a review by the Lancet Commission Task Force on public health measures to suppress the pandemic
  • 2021
  • Ingår i: International Health. - : Oxford University Press (OUP). - 1876-3413 .- 1876-3405. ; 13:5, s. 399-409
  • Forskningsöversikt (refereegranskat)abstract
    • The Lancet COVID-19 Commission Task Force for Public Health Measures to Suppress the Pandemic was launched to identify critical points for consideration by governments on public health interventions to control coronavirus disease 2019 (COVID-19). Drawing on our review of published studies of data analytics and modelling, evidence synthesis and contextualisation, and behavioural science evidence and theory on public health interventions from a range of sources, we outline evidence for a range of institutional measures and behaviour-change measures. We cite examples of measures adopted by a range of countries, but especially jurisdictions that have, thus far, achieved low numbers of COVID-19 deaths and limited community transmission of severe acute respiratory syndrome coronavirus 2. Finally, we highlight gaps in knowledge where research should be undertaken. As countries consider long-term measures, there is an opportunity to learn, improve the response and prepare for future pandemics.
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