The energy density of Li ion batteries (LIBs) needs to be improved for the requirement of electric vehicles, hybrid electric vehicles and smart grids. Developing high-voltage LIBs is an important ...trend. In recent years, high-voltage cathode materials, such as LiCoPO4, Li3V2(PO4)3, Li2CoPO4F, LiNi0.5Mn1.5O4, and lithium-rich layered oxides, and matched electrolytes including stable solvents and functional additives, have been investigated extensively. In this review, we summarize the recent progress in high-voltage cathode materials and matched electrolytes, as well as the optimization of other cell components such as conductive agents, binders, positive cans, separators and current collectors. The problems and prospects of high-voltage LIBs are also discussed.
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•The progress is summarized for cathode materials in high-voltage Li ion batteries.•The development in high-voltage electrolytes is particularly reviewed, as well as other cell components.•Also, the challenges and prospects of high-voltage Li ion batteries are discussed.
Background. Whether cytomegalovirus (CMV) DNA exists in plasma as virion-associated or free DNA is uncertain. Methods. An assay combining DNase I digestion and CMV quantitative polymerase chain ...reaction (DNase-CMV-qPCR) was developed to differentiate free naked DNA from virion DNA. One hundred three frozen and 10 fresh CMV DNA-positive plasma samples from solid-organ transplant recipients (SOTRs) were tested. Three sets of paired qPCR (P-qPCR) assays with amplicons of variable length were used to study CMV DNA fragmentation in 20 SOTR plasma samples, viral stocks (Towne, Merlin, AD169) and the first World Health Organization (WHO) international standard (IS) for CMV DNA. Results. In all plasma samples, 98.8%–100% of CMV DNA was free DNA; this was the only form in 93 of 103 (90.3%) frozen and all 10 fresh samples tested using DNase-CMV-qPCR. Low levels of virion CMV DNA were found in 10 of 103 (9.7%) samples with higher total DNA load. Cytomegalovirus DNA results were highly reproducible for 3 CMV virus stocks and WHO IS (P > .80), tested by three sets of paired q-PCR. However, for the 20 SOTR plasma samples, the smaller amplicon assay result was 2.6-fold, 3.4-fold, and 6.5-fold higher than the longer amplicion result (P < .001). Conclusions. Cytomegalovirus DNA in SOTR plasma is almost exclusively free DNA, highly fragmented, and not virion associated.
We identified a novel recombinant GII.P16-GII.12 norovirus associated with epidemic and endemic gastroenteritis during March 1, 2018-February 12, 2019, in Alberta, Canada. GII.12 viruses have not ...been detected in Alberta since 2000. Comparing the full genome of this strain to previously published sequences revealed this virus to be a novel recombinant strain.
Abstract
Background
The epidemiology of single versus multiple cytomegalovirus (CMV) strain transmission from donor (D+) to seronegative solid organ transplant (SOT) recipients (R−) is uncertain, as ...is whether “relapsing” recipient infection represents changing strain predominance when multiple strains are transmitted. Here we characterized CMV strain transmission patterns in D+/R− SOT recipients.
Methods
We studied pairs or groups of D+/R− SOT recipients who received organs from a common donor (group A) and recipients who experienced ≥2 waves of CMV DNAemia (group B). CMV in plasma was characterized by genotype-specific real-time PCR for genes gB and gH.
Results
Single concordant genotypes were identified in 12 of 18 recipient pairs/group sharing a common donor (group A); at least 6 of 18 (33%) donors transmitted > 1 strain. A single CMV strain was detected in 14 of 15 recipients in group B; only 1 recipient had coinfection. A shift in CMV strain predominance occurred after the first posttransplant year in at least 4 recipients with coinfection.
Conclusions
Using a common donor approach, we confirmed that multiple CMV strain transmission from donors to R− SOT recipients is not uncommon. D+/R− SOT recipients with CMV coinfection can undergo changes in strain predominance in late waves of CMV DNAemia.
Although multiple strain transmission by SOT donors is not uncommon, most D+/R− recipient recurrent CMV DNAemia was due to infection with the same single strain. In coinfected recipients, late CMV DNAemia waves frequently demonstrated CMV strain predominance shifts
Background. Interassay harmonization of cytomegalovirus (CMV) DNA measurement is important for infection management. Uncertainty exists regarding the result harmonization achievable in patient plasma ...samples using quantitative polymerase chain reaction (qPCR) assays with calibrators now traceable to the First World Health Organization International Standard (IS) for CMV DNA. Method. Serial dilutions of the IS and a blinded panel of 40 genotypes CMV DNA-positive pooled plasma samples and 10 negative plasma samples were tested by 6 laboratories using 10 qPCR assays calibrated to the IS. Each clinical sample was constructed using plasma from a single unique transplant recipient. Results. The variance for individual CMV DNA-positive samples was greater for clinical samples (median, 1.50 range, 1.22–2.82 log10 IU/mL) than for IS dilutions (median, 0.94 range, 0.69–1.35 log10 IU/mL (P < .001); 58.9% of all clinical sample results and 93.6% of IS dilution results fell within ±0.5 log10 IU/mL of the mean viral load of each sample. Result variability was not impacted by either genotype or quantitative levels of CMV DNA. Testing procedure differences can significantly influence results, even when analyte-specific reagents are identical. For clinical samples, all assays demonstrated result bias (P < .008). Assays with amplicon sizes ≤86 bp had significantly higher results compared to assays with larger amplicon sizes (≥105 bp) (P < .001). Conclusions. The variability in CMV DNA results reported on individual samples has been reduced by the IS, but ongoing clinically relevant variability persists, preventing meaningful interassay result comparison.
The prevalence and seasonal variation of 7 viruses in 6 major rivers in Alberta were assessed using a combination of qPCR, cell culture and integrated cell culture with qPCR (ICC-qPCR). Water samples ...were collected monthly from rivers at different sites upstream and downstream of major urban centers. Seven viruses including rotavirus, adenovirus, astrovirus, norovirus, sapovirus, JC virus and enterovirus, were detected in at least one of the water samples at each site using qPCR. Rotavirus was most common with concentration ranging from 2.3 to 4.5 log10 genomic equivalent (GE) copies/L. Norovirus, sapovirus, astrovirus, adenoviruses and JC virus peaked during the winter (November to March). Viruses were most prevalent at the Bow River sampling site downstream of the City of Calgary, followed by the North Saskatchewan River site downstream of the City of Edmonton and the Red Deer River site downstream of the City of Red Deer. The detection rates and quantity of viruses had significant difference in the sampling sites between upstream and downstream of major urban centers (p < 0.001). 14% of the samples tested positive using viral culture indicating the presence of infectious viruses in river. Sequencing analysis identified human rotavirus in 75% of the samples collected from downstream versus 37% of the samples collected from upstream sites (p < 0.02). Multivariate binary regression showed that human activity in watersheds is a significant determinant of viruses in Alberta's Rivers. The discharge from wastewater treatment plants may be the possible sources of viral contamination. Seasonal coincidence of acute viral gastroenteritis outbreaks and monthly peak occurrence of enteric viruses in river water implies potential impact of waterborne viruses on human health.
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•Seven viruses were detected in 6 major rivers across Alberta by qPCR.•Rotavirus and adenovirus were the most common viruses detected all year around.•Norovirus, sapovirus, astrovirus and adenovirus had seasonal peak during winter.•Viruses were more frequently detected at downstream of cities along the river.•Infectious viruses were detected in 14% of the samples by cell culture and ICC-qPCR.
Norovirus GII.4 is the predominant genotype circulating worldwide over the last decade causing 80% of all norovirus outbreaks with new GII.4 variants reported in parallel with periodic epidemic waves ...of norovirus outbreaks. The circulating new GII.4 variants and the epidemiology of norovirus outbreaks in Alberta, Canada have not been described. Our hypothesis is that the periodic epidemic norovirus outbreak activity in Alberta was driven by new GII.4 variants evolving by genetic drift.
The Alberta Provincial Public Health Laboratory performed norovirus testing using RT-PCR for suspected norovirus outbreaks in the province and the northern Territories between 2000 and 2008. At least one norovirus strain from 707 out of 1,057 (66.9%) confirmed norovirus outbreaks were successfully sequenced. Phylogenetic analysis was performed using BioNumerics and 617 (91.1%) outbreaks were characterized as caused by GII.4 with 598 assigned as novel variants including: GII.4-1996, GII.4-2002, GII.4-2004, GII.4-2006a, GII.4-2006b, GII.4-2008a and GII.4-2008b. Defining July to June of the following year as the yearly observation period, there was clear biannual pattern of low and high outbreak activity in Alberta. Within this biannual pattern, high outbreak activity followed the emergence of novel GII.4 variants. The two variants that emerged in 2006 had wider geographic distribution and resulted in higher outbreak activity compared to other variants. The outbreak settings were analyzed. Community-based group residence was the most common for both GII.4 variants and non-GII.4 variants. GII.4 variants were more commonly associated with outbreaks in acute care hospitals while outbreaks associated non-GII.4 variants were more commonly seen in school and community social events settings (p<0.01).
The emergence of new norovirus GII.4 variants resulted in an increased norovirus outbreak activity in the following season in a unique biannual pattern in Alberta over an eight year period. The association between antigenic drift of GII.4 strains and epidemic norovirus outbreak activity could be due to changes in host immunity, viral receptor binding efficiency or virulence factors in the new variants. Early detection of novel GII.4 variants provides vital information that could be used to forecast the norovirus outbreak burden, enhance public health preparedness and allocate appropriate resources for outbreak management.
Analysis of complete capsid sequences of the emerging norovirus GII.17 Kawasaki 308 from 13 countries demonstrated that they originated from a single haplotype since the initial emergence in China in ...late 2014. Global spread of a sublineage SL2 was identified. A new sublineage SL3 emerged in China in 2016.
The emergence of norovirus genotype GII.4 variants has been associated with gastroenteritis pandemics worldwide, prompting molecular surveillance for early detection of novel strains. In this study, ...we aimed to analyze the outbreak activity of norovirus and characterize the norovirus strains circulating in Alberta between July 2012 and February 2018.
Stool samples from gastroenteritis outbreaks in Alberta were tested for norovirus at the Provincial Laboratory for Public Health using a multiplex real time-RT PCR assay. The ORF1 and ORF2-genotypes of norovirus positive samples were assigned based on phylogenetic analyses of partial polymerase and capsid sequences, respectively.
A total of 530 norovirus outbreaks were identified. During July 2012 and June 2017 there was a gradual decrease in the annual number of GII.4 outbreaks, however, outbreak numbers increased from June 2017-February 2018. Four novel strains emerged: GII.17 Kawasaki in July 2014-June 2015, GII.P16/GII.4 Sydney in July 2015-June 2016, GII.P16/GII.2 and GII.P4 New Orleans/GII.4 Sydney in July 2016-June 2017. GII.Pe/GII.4 Sydney was the single predominant strain responsible for the majority (over 50%) of all norovirus outbreaks up to June 2015. Between June 2017 and February 2018, GII.P16/GII.4 Sydney was the leading strain causing 63% of all norovirus outbreaks.
GII.4 stands as the predominant capsid genotype causing a large majority of the norovirus outbreaks in early 2018. An increase in genotype diversity was observed in the last years, characterized by a high circulation of non-GII.4 strains and GII.4 recombinants.
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