Insertion/deletion correction by using parallel-interconnected viterbi decoders

Abstract: A new insertion/deletion correction scheme is presented for standard convolutional codes that makes use of multiple parallel-interconnected Viterbi decoders. Whenever an insertion or deletion error occurs, the connections between different Viterbi decoders ensure that decoding will proceed from the decoder that is in synchronization . In this way, a larger Viterbi decoder is created that can correct insertion and/or deletion errors by extending the Viterbi algorithm to encompass all parallel decoders. Further, it is shown how the performance can be improved by inverting certain bits during the encoding of the convolutional codes. This lowers the frequency of occurrence of repeating sequences, which is detrimental to synchronization when dealing with insertions/deletions

Enhanced upconversion emission of Er3+-Yb3+ co-doped Ba5 (PO4) 3OH powder phosphor for application in photodynamic therapy

Er3+-Yb3+ co-doped Ba5(PO4)3OH nanoparticle powder phosphors were successfully synthesized by urea combustion method. The resulting powder phosphors were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HRSEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL). XRD data confirmed crystallization of pure hexagonal phase of Ba5(PO4)3OH and HRSEM images showed formation of ellipsoidal particles. XPS data combined with EDS analysis confirmed the materials composition that corresponds with identification of all the chemical elements constituting the materials. The in vitro dark cytotoxicity of the particles confirmed lack of cytocidal behaviour in the absence of light, but considerable photodynamic therapy (PDT) activity was observed upon illumination. Upon excitation using a 980 nm laser, multiple emission peaks in the green and red regions corresponding to the optical transitions of Er3+ ion were observed. Upon co-doping with Yb3+, upconverted red emission was detected and this was attributable to non-radiative energy transfer from Yb3+ to Er3+. The proposed mechanism of upconversion photoluminescence is discussed

Definition and Validation of the American College of Rheumatology 2021 Juvenile Arthritis Disease Activity Score Cutoffs for Disease Activity States in Juvenile Idiopathic Arthritis

Export Date: 16 February 2023; Cited By: 10Peer reviewe

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

Effect of initial nickel particle size on stability of nickel catalysts for aqueous phase reforming

The deactivation behavior by crystallite growth of nickel nanoparticles on various supports (carbon nanofibers, zirconia, SiC, α-Al2O3 and γ-Al2O3) was investigated in the aqueous phase reforming of ethylene glycol. Supported Ni catalysts of ∼10 wt% were prepared by impregnation of carbon nanofibers (CNF), ZrO2, SiC, γ-Al2O3 and α-Al2O3. The extent of the Ni nanoparticle growth on various support materials follows the order CNF ∼ ZrO2 > SiC > γ-Al2O3 >> α-Al2O3 which sequence, however, was determined by the initial Ni particle size. Based on the observed nickel leaching and the specific growth characteristics; the particle size distribution and the effect of loading on the growth rate, Ostwald ripening is suggested to be the main mechanism contributing to nickel particle growth. Remarkably, initially smaller Ni particles (∼12 nm) supported on α-Al2O3 were found to outgrow Ni particles with initially larger size (∼20 nm). It is put forward that the higher susceptibility with respect to oxidation of the smaller Ni nanoparticles and differences in initial particle size distribution are responsible for this behavior

Effect of initial nickel particle size on stability of nickel catalysts for aqueous phase reforming

The deactivation behavior by crystallite growth of nickel nanoparticles on various supports (carbon nanofibers, zirconia, SiC, α-Al2O3 and γ-Al2O3) was investigated in the aqueous phase reforming of ethylene glycol. Supported Ni catalysts of ∼10 wt% were prepared by impregnation of carbon nanofibers (CNF), ZrO2, SiC, γ-Al2O3 and α-Al2O3. The extent of the Ni nanoparticle growth on various support materials follows the order CNF ∼ ZrO2 > SiC > γ-Al2O3 >> α-Al2O3 which sequence, however, was determined by the initial Ni particle size. Based on the observed nickel leaching and the specific growth characteristics; the particle size distribution and the effect of loading on the growth rate, Ostwald ripening is suggested to be the main mechanism contributing to nickel particle growth. Remarkably, initially smaller Ni particles (∼12 nm) supported on α-Al2O3 were found to outgrow Ni particles with initially larger size (∼20 nm). It is put forward that the higher susceptibility with respect to oxidation of the smaller Ni nanoparticles and differences in initial particle size distribution are responsible for this behavior

TOF SIMS analysis, structure and photoluminescence properties of pulsed laser deposited CaS:Eu2+ thin films

CaS:Eu2þ thin films weredepositedonSi(100)substratesusingthepulsedlaserdepositiontechniqueto investigatetheeffectofargon(Ar),oxygen(O2), andvacuumdepositionatmospheresonthestructural, morphological andphotoluminescencepropertiesofthethin films. Thephosphortargetwasablated using a266nmNd:YAGlaser.X-raydiffraction,atomicforcemicroscopy,scanningelectronmicroscopy, energy dispersiveX-ray, fluorescencespectrophotometryandtime-of-flight secondaryionmassspec- trometry wereusedtocharacterizethethin films. Thethin films preparedinoxygenwereessentially amorphous, whilethosepreparedinargonandvacuumshowedsomedegreeofcrystallinity.The film deposited inArshowedbetterphotoluminescenceintensitythanthosedepositedinanO2 and vacuum. The emissionobservedataround650nmforallthe films isattributedtothetransitionsfromtheexcited 4f F 5dt 6 0 7 1 [ ] ( 2g) state tothegroundstate 4f7 S 7/2 8 ( ) of theEu2þ ions. Theemissionat618nm,whichismore prominent inthe film preparedinO2, isascribedtothe 5D F 0 2 7 → transitions inEu3þ, suggestingthatEu2þ wasunintentionallyoxidizedtoEu3þ. Theatomicforcemicroscopydatashowedthatthe film prepared in argonwasrougherthanthosepreparedinoxygenandvacuum.This workwas financially supportedbythecompetitivepro- gramme forratedresearchers(Grantno.CPR20110724000021870) of theSouthAfricanNationalResearchFoundation(NRF),the South AfricanResearchChairsInitiativeoftheDepartmentof Science andTechnology(Grantno.84415)therentalpoolpro- grammeoftheNationalLaserCentre(NLC)(Grantno.NLC- LREGM00-CON-001).CaS:Eu2þ thin films weredepositedonSi(100)substratesusingthepulsedlaserdepositiontechniqueto investigatetheeffectofargon(Ar),oxygen(O2), andvacuumdepositionatmospheresonthestructural, morphological andphotoluminescencepropertiesofthethin films. Thephosphortargetwasablated using a266nmNd:YAGlaser.X-raydiffraction,atomicforcemicroscopy,scanningelectronmicroscopy, energy dispersiveX-ray, fluorescencespectrophotometryandtime-of-flight secondaryionmassspec- trometry wereusedtocharacterizethethin films. Thethin films preparedinoxygenwereessentially amorphous, whilethosepreparedinargonandvacuumshowedsomedegreeofcrystallinity.The film deposited inArshowedbetterphotoluminescenceintensitythanthosedepositedinanO2 and vacuum. The emissionobservedataround650nmforallthe films isattributedtothetransitionsfromtheexcited 4f F 5dt 6 0 7 1 [ ] ( 2g) state tothegroundstate 4f7 S 7/2 8 ( ) of theEu2þ ions. Theemissionat618nm,whichismore prominent inthe film preparedinO2, isascribedtothe 5D F 0 2 7 → transitions inEu3þ, suggestingthatEu2þ wasunintentionallyoxidizedtoEu3þ. Theatomicforcemicroscopydatashowedthatthe film prepared in argonwasrougherthanthosepreparedinoxygenandvacuum

Energy Transfer Mechanisms and Optical Thermometry of BaMgF4:Yb3+,Er3+ Phosphor

Motivated from our previous studies on the upconversion properties of BaMgF4:Yb3+,Tb3+ phosphor, here we investigated the upconversion properties of BaMgF4:Yb3+,Er3+ phosphor. We demonstrate a two-way versatile approach for the fine-tuning of emission from green to the red region, by varying the dopant concentration and adjusting the pulse width of an infrared laser. The mechanism involved in tuning the emission color by laser power and pulse width variation was illustrated in detail. The temperature dependent upconversion spectra were studied by analyzing the fluorescence intensity ratio of the thermally coupled levels. The maximum sensitivity obtained is 83.29 x 10(-4) K-1 at 583 K, which is much higher than the temperature sensitivity reported for other fluoride based materials. Moreover, the influence of the excitation power density on the ability of the phosphor for temperature sensing was also investigated. We obtained a maximum (similar to 415 K) temperature detection at 2563 mW laser power. The obtained results illustrate the potential use of BaMgF4:Yb3+,Er3+ phosphor in an optical thermometer due to its highly sensitive temperature detection ability

Persistent luminescence excitation spectroscopy of BaAl₂O₄:Eu²⁺,Dy³⁺

BaAl2O4:Eu2+,Dy3+ is related, both by structure and luminescence, to one of the best persistent luminescent phosphors, SrAl2O4:Eu2+,Dy3+. At room temperature (RT), the green persistent emission of BaAl2O4:Eu2+,Dy3+ remains visible for hours after ceasing irradiation. Similar to SrAl2O4, BaAl2O4 with hexagonal P63 structure, has two M2+ sites, but, limited optical activity from the 2nd site is observed in the emission of BaAl2O4:Eu2+,Dy3+ - even at 77 K. Using combined approach of photoluminescence, thermoluminescence (TL), and persistent (excitation) luminescence measurements, the origin and properties of persistent luminescence of BaAl2O4:Eu2+,Dy3+ were studied in detail. Ultraviolet (UV) excited and persistent emission are identical and no contribution from the Eu2+ in the high-symmetry Ba site was observed. TL excitation spectra clarified the unstructured conventional excitation spectrum; now it is evident that defects or the Dy3+ co-dopant do not contribute to persistent luminescence via direct energy absorption. Mechanisms for persistent luminescence should thus be revised.Accepted Author ManuscriptRST/Luminescence Material