► The capacity degradation of lithium battery was characterized by an ensemble model. ► The remaining useful performance was presented as probability distribution. ► The robustness of the algorithm ...was verified by different datasets. ► More measured data, more accurate prediction results.
We developed an ensemble model to characterize the capacity degradation and predict the remaining useful performance (RUP) of lithium-ion batteries. Our model fuses an empirical exponential and a polynomial regression model to track the battery’s degradation trend over its cycle life based on experimental data analysis. Model parameters are adjusted online using a particle filtering (PF) approach. Experiments were conducted to compare our ensemble model’s prediction performance with the individual results of the exponential and polynomial models. A validation set of experimental battery capacity data was used to evaluate our model. In our conclusion, we presented the limitations of our model.
The battery management system (BMS) is a critical component of electric and hybrid electric vehicles. The purpose of the BMS is to guarantee safe and reliable battery operation. To maintain the ...safety and reliability of the battery, state monitoring and evaluation, charge control, and cell balancing are functionalities that have been implemented in BMS. As an electrochemical product, a battery acts differently under different operational and environmental conditions. The uncertainty of a battery’s performance poses a challenge to the implementation of these functions. This paper addresses concerns for current BMSs. State evaluation of a battery, including state of charge, state of health, and state of life, is a critical task for a BMS. Through reviewing the latest methodologies for the state evaluation of batteries, the future challenges for BMSs are presented and possible solutions are proposed as well.
The role of subclinical severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in perpetuating the COVID-19 pandemic is unknown because population seroprevalence data are absent. We ...aimed to establish the sensitivity and specificity of our enzyme immunoassay and microneutralisation assay, and the seroprevalence of SARS-CoV-2 in Hong Kong before and after the pandemic, as well as in Hong Kong residents evacuated from Hubei province, China.
We did a multicohort study in a hospital and university in Hong Kong. We evaluated the sensitivity of our enzyme immunoassay and microneutralisation assay with RT-PCR data from patients positive for SARS-CoV-2 and the specificity of our enzyme immunoassay and microneutralisation assay with archived serum samples collected before 2019. We compared the seropositivity of the general population of Hong Kong before and after the pandemic had begun, and determined the seropositivity of Hong Kong residents evacuated from Hubei province, China, in March, 2020.
Between Feb 26 and March 18, 2020, we assessed RT-PCR samples from 45 patients who had recovered from COVID-19 to establish the sensitivity of our enzyme immunoassay and microneutralisation assay. To establish the specificity of these assays, we retrieved archived serum. The sensitivity was 91·1% (41 of 45 95% CI 78·8–97·5) for the microneutralisation assay, 57·8% (26 of 45 42·2–72·3) for anti-nucleoprotein IgG, 66·7% (30 of 45 51·1–80·0) for anti-spike protein receptor binding domain (RBD) IgG, and 73·3% (33 of 45 58·1–85·4) for enzyme immunoassay (either positive for anti-nucleoprotein or anti-RBD IgG). The specificity was 100% (152 of 152 95% CI 97·6–100·0) for both the enzyme immunoassay and microneutralisation assay. Among the Hong Kong general population, 53 (2·7%) of 1938 were enzyme immunoassay positive, but of those who were positive, all 53 were microneutralisation negative, and no significant increase was seen in the seroprevalence between April 12, 2018, and Feb 13, 2020. Among asymptomatic Hubei returnees, 17 (4%) of 452 were seropositive with the enzyme immunoassay or the microneutralisation assay, with 15 (88%) of 17 seropositive with the microneutralisation assay, and two familial clusters were identified.
Our serological data suggest that SARS-CoV-2 is a new emerging virus. The seropositivity rate in Hubei returnees indicates that RT-PCR-confirmed patients only represent a small proportion of the total number of cases. The low seroprevalence suggests that most of the Hong Kong and Hubei population remain susceptible to COVID-19. Future waves of the outbreak are inevitable without a vaccine or antiviral prophylaxis. The role of age-related cross reactive non-neutralising antibodies in the pathogenesis of COVID-19 warrants further investigation.
Richard and Carol Yu, May Tam Mak Mei Yin, Shaw Foundation (Hong Kong), Michael Tong, Marina Lee, and the Government Consultancy Service (see acknowledgments for full list).
•Nonpharmaceutical interventions were effective in reducing COVID-19 transmission.•Social distancing is more effective than the other NPIs in containing COVID-19.•Two or more synchronous NPIs are ...more effective than a single type of NPI.
To evaluate and compare the effectiveness of four types of non-pharmaceutical interventions (NPIs) to contain the time-varying effective reproduction number (Rt) of coronavirus disease-2019 (COVID-19).
This study included 1,908,197 confirmed COVID-19 cases from 190 countries between 23 January and 13 April 2020. The implemented NPIs were categorised into four types: mandatory face mask in public, isolation or quarantine, social distancing and traffic restriction (referred to as mandatory mask, quarantine, distancing and traffic hereafter, respectively).
The implementations of mandatory mask, quarantine, distancing and traffic were associated with changes (95% confidence interval, CI) of −15.14% (from −21.79% to −7.93%), −11.40% (from −13.66% to −9.07%), −42.94% (from −44.24% to −41.60%) and −9.26% (from −11.46% to −7.01%) in the Rt of COVID-19 when compared with those without the implementation of the corresponding measures. Distancing and the simultaneous implementation of two or more types of NPIs seemed to be associated with a greater decrease in the Rt of COVID-19.
Our study indicates that NPIs can significantly contain the COVID-19 pandemic. Distancing and the simultaneous implementation of two or more NPIs should be the strategic priorities for containing COVID-19.
Abstract Sensory neurons express a variety of voltage-gated Ca2+ channel subtypes, but reports differ on their proportionate representation, and the effects of painful nerve injury on each subtype ...are not established. We compared levels of high-voltage activated currents in medium-sized (30–40 μm) dorsal root ganglion neurons dissociated from control animals and those subjected to spinal nerve ligation, using sequential application of semiselective channel blockers (nisoldipine for L -type, SNX-111 or ω-conotoxin GVIA for N-type, agatoxin IVA or ω-conotoxin MVIIC for P/Q-type, and SNX-482 for a component of R-type) during either square wave depolarizations or action potential waveform voltage commands. Using sequential administration of multiple blockers, proportions of total Ca2+ current attributable to different subtypes and the effect of injury depended on the sequence of blocker administration and type of depolarization command. Overall, however, N-type and L -type currents comprised the dominant components of ICa in sensory neurons under control conditions, and these subtypes showed the greatest loss of current following injury ( L -type 26–71% loss, N-type 0–51% loss). Further exploration of N-type current identified by its sensitivity to ω-conotoxin GVIA applied alone showed that injury reduced the peak N-type current during step depolarization by 68% and decreased the total charge entry during action potential waveform stimulation by 44%. Isolation of N-type current by blockade of all other subtypes demonstrated a 50% loss with injury, and also revealed an injury-related rightward shift in the activation curve. Non-stationary noise analyses of N-type current in injured neurons revealed unitary channel current and number of channels that were not different from control, which indicates that injury-induced loss of current is due to a decrease in channel open probability. Our findings suggest that diminished Ca2+ influx through N-type and L -type channels may contribute to sensory neuron dysfunction and pain after nerve injury.
Abstract ATP-sensitive potassium (KATP ) channels may be linked to mechanisms of pain after nerve injury, but remain under-investigated in primary afferents so far. We therefore characterized these ...channels in dorsal root ganglion (DRG) neurons, and tested whether they contribute to hyperalgesia after spinal nerve ligation (SNL). We compared KATP channel properties between DRG somata classified by diameter into small or large, and by injury status into neurons from rats that either did or did not become hyperalgesic after SNL, or neurons from control animals. In cell-attached patches, we recorded basal KATP channel opening in all neuronal subpopulations. However, higher open probabilities and longer open times were observed in large compared to small neurons. Following SNL, this channel activity was suppressed only in large neurons from hyperalgesic rats, but not from animals that did not develop hyperalgesia. In contrast, no alterations of channel activity developed in small neurons after axotomy. On the other hand, cell-free recordings showed similar ATP sensitivity, inward rectification and unitary conductance (70–80 pS) between neurons classified by size or injury status. Likewise, pharmacological sensitivity to the KATP channel opener diazoxide, and to the selective blockers glibenclamide and tolbutamide, did not differ between groups. In large neurons, selective inhibition of whole-cell ATP-sensitive potassium channel current (IK(ATP) ) by glibenclamide depolarized resting membrane potential (RMP). The contribution of this current to RMP was also attenuated after painful axotomy. Using specific antibodies, we identified SUR1, SUR2, and Kir6.2 but not Kir6.1 subunits in DRGs. These findings indicate that functional KATP channels are present in normal DRG neurons, wherein they regulate RMP. Alterations of these channels may be involved in the pathogenesis of neuropathic pain following peripheral nerve injury. Their biophysical and pharmacological properties are preserved even after axotomy, suggesting that KATP channels in primary afferents remain available for therapeutic targeting against established neuropathic pain.
Background
This study evaluates the contemporary care for patients with locally recurrent nasopharyngeal carcinoma after failure of the primary course of intensity modulated radiotherapy.
Methods
...Eligible patients were identified through the Hong Kong Cancer Registry database. Patterns of care and treatment outcomes were analyzed.
Results
Two hundred seventy‐two patients with locally recurrent tumors were identified. Of them, 30.9% received surgery, whereas 35.7% received re‐irradiation (re‐RT). The 5‐year overall survival (OS) for the whole group was 30.2%. Old age and advanced rT classification were adverse prognostic factors, whereas surgery (mainly in resectable recurrence) was associated with favorable survival outcome. The 5‐year OS rates for patients who received surgery and re‐RT were 56.3% and 21.8%, respectively.
Conclusions
Early detection of resectable recurrence is of paramount importance as surgery for resectable tumors offers the potential to achieve excellent outcomes. Re‐RT could be considered in selected patients with unresectable disease and favorable prognostic features.
Norovirus genogroup II genotype 4 (GII.4) has been the predominant cause of viral gastroenteritis since 1996. Here we show that during the winter of 2014-2015, an emergent variant of a previously ...rare norovirus GII.17 genotype, Kawasaki 2014, predominated in Hong Kong and outcompeted contemporary GII.4 Sydney 2012 in hospitalized cases. GII.17 cases were significantly older than GII.4 cases. Root-to-tip and Bayesian BEAST analyses estimate GII.17 viral protein 1 (VP1) evolves one order of magnitude faster than GII.4 VP1. Residue substitutions and insertion occur in four of five inferred antigenic epitopes, suggesting immune evasion. Sequential GII.4-GII.17 infections are noted, implicating a lack of cross-protection. Virus bound to saliva of secretor histo-blood groups A, B and O, indicating broad susceptibility. This fast-evolving, broadly recognizing and probably immune-escaped emergent GII.17 variant causes severe gastroenteritis and hospitalization across all age groups, including populations who were previously less vulnerable to GII.4 variants; therefore, the global spread of GII.17 Kawasaki 2014 needs to be monitored.
To evaluate the psychometric properties of the traditional Chinese version of the Childbirth Experience Questionnaire (CEQ 2.0) and assess the childbirth experiences of Chinese women.
A ...cross-sectional survey was conducted in Hong Kong from July 2020 to February 2021. In total, 975 mothers, who could read traditional Chinese and gave birth in 2020 or 2021, were included in the analysis. Data were fitted into the model proposed by the original developers using the confirmatory factor analysis. The data were then randomly split into training and validation sets for exploratory and confirmatory factor analyses. Childbirth experiences were assessed. Factor structure, internal construct validity, internal consistency, and known-group validity were assessed.
The originally proposed CEQ2.0 model showed a poor fit. An exploratory factor analysis identified a revised four-factor model (CEQ2.0-R) on a randomly split sample, which showed a satisfactory fit (CFI=0.912; TLI=0.884; SRMR=.053; RMSEA=0.072) on the other split sample. The revised scale comprised 13 items and four domains: (1)"Own capacity" (6 items), (2) "General support" (3 items), (3) "Perceived safety" (2 items), and (4) "Professional support" (2 items). CEQ2.0-R showed high internal construct validity and reliability. It can differentiate between participants with different characteristics, including parity, oxytocin augmentation, and companionship during labour. The childbirth experiences of the participants were merely positive, and participants reported that more support from midwives is needed.
CEQ2.0-R can adequately describe the childbirth experiences of women in Hong Kong. The questionnaire is easy to be administer and can be used to assess several domains of the childbirth experiences. It may be useful to evaluate the aspects of support needed during childbirth.
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