•This study applied a logistic growth model with parameters estimated by a non-linear least squares (NLS) method to daily new COVID-19 cases.•The model fitted time-series data exceedingly well for ...the whole of China, eleven selected Chinese provinces and municipalities, South Korea and Iran.•This study provided key estimates and a 95% confidence interval for parameters K, r, and P0.•This study found that the growth rates of outbreaks differed between provinces in China and between South Korea and Iran.•As of March 13, 2020, this study's model suggested that countries such as the U.S.A., France, Italy, and Spain were still in the early stages of outbreaks.
As the coronavirus disease 2019 (COVID-19) pandemic continues to proliferate globally, this paper shares the findings of modelling the outbreak in China at both provincial and national levels. This paper examines the applicability of the logistic growth model, with implications for the study of the COVID-19 pandemic and other infectious diseases.
An NLS (Non-Linear Least Squares) method was employed to estimate the parameters of a differentiated logistic growth function using new daily COVID-19 cases in multiple regions in China and in other selected countries. The estimation was based upon training data from January 20, 2020 to March 13, 2020. A restriction test was subsequently implemented to examine whether a designated parameter was identical among regions or countries, and the diagnosis of residuals was also conducted. The model's goodness of fit was checked using testing data from March 14, 2020 to April 18, 2020.
The model presented in this paper fitted time-series data exceedingly well for the whole of China, its eleven selected provinces and municipalities, and two other countries - South Korea and Iran - and provided estimates of key parameters. This study rejected the null hypothesis that the growth rates of outbreaks were the same among ten selected non-Hubei provinces in China, as well as between South Korea and Iran. The study found that the model did not provide reliable estimates for countries that were in the early stages of outbreaks. Furthermore, this study concured that the R2 values might vary and mislead when compared between different portions of the same non-linear curve. In addition, the study identified the existence of heteroskedasticity and positive serial correlation within residuals in some provinces and countries.
The findings suggest that there is potential for this model to contribute to better public health policy in combatting COVID-19. The model does so by providing a simple logistic framework for retrospectively analyzing outbreaks in regions that have already experienced a maximal proliferation in cases. Based upon statistical findings, this study also outlines certain challenges in modelling and their implications for the results.
Abstract
Background
Recent studies have focused on initial clinical and epidemiological characteristics of the coronavirus disease 2019 (COVID-19), which is the mainly revealing situation in Wuhan, ...Hubei.
Aim
This study aims to reveal more data on the epidemiological and clinical characteristics of COVID-19 patients outside of Wuhan, Zhejiang, China.
Design
This study was a retrospective case series.
Methods
Eighty-eight cases of laboratory-confirmed and three cases of clinically confirmed COVID-19 were admitted to five hospitals in Zhejiang province, China. Data were collected from 20 January 2020 to 11 February 2020.
Results and discussion
Of all 91 patients, 88 (96.70%) were laboratory-confirmed COVID-19 with throat swab samples that tested positive for SARS-Cov-2, three (3.30%) cases were clinically diagnosed. The median age of the patients was 50 (36.5–57) years, and female accounted for 59.34%. In this sample, 40 (43.96%) patients had contracted the disease from local cases, 31 (34.07%) patients had been to Wuhan/Hubei, eight (8.79%) patients had contacted with people from Wuhan, and 11 (12.09%) patients were diagnosed after having flown together in the same flight with no passenger that could later be identified as the source of infection. In particular within the city of Ningbo, 60.52% cases can be traced back to an event held in a temple. The most common symptoms were fever (71.43%), cough (60.44%) and fatigue (43.96%). The median of incubation period was 6 (interquartile range 3–8) days and the median time from the first visit to a doctor to the confirmed diagnosis was 1 (1–2) days. According to the chest computed tomography scans, 67.03% cases had bilateral pneumonia.
Conclusions
Social activity cluster, family cluster and flying alongside with persons already infected with COVID-19 were how people got infected with COVID-19 in Zhejiang.
Background Phase II data suggested that guselkumab, an anti-interleukin-23 monoclonal antibody, was efficacious in psoriasis. Objective We sought to assess efficacy and safety of guselkumab in ...moderate to severe psoriasis versus placebo and adalimumab, including interrupted treatment and switching adalimumab nonresponders to guselkumab. Methods Patients were randomized to guselkumab 100 mg (weeks 0 and 4, then every 8 weeks; n = 496); placebo→guselkumab (weeks 0, 4, and 12 then guselkumab at weeks 16 and 20; n = 248); or adalimumab (80 mg week 0, then 40 mg week 1, and every 2 weeks through week 23; n = 248). At week 28, guselkumab 90% or greater improvement in Psoriasis Area and Severity Index (PASI) score from baseline (PASI 90) responders were rerandomized to guselkumab or placebo with guselkumab after loss of response. Placebo→guselkumab responders and adalimumab responders received placebo, then guselkumab after loss of response. Nonresponders received guselkumab. Results At week 16, more patients receiving guselkumab achieved an Investigator Global Assessment (IGA) score 0/1 (cleared/minimal) (84.1% vs 8.5%) and PASI 90 (70.0% vs 2.4%) versus placebo (coprimary end points). Guselkumab was superior to adalimumab at week 16 (IGA score 0/1, 75% or greater improvement in PASI score from baseline, and PASI 90) and week 24 (IGA score 0/1 and 0, PASI 90, 100% improvement in PASI score from baseline) ( P < .001). From weeks 28 to 48, better persistence of response was observed in guselkumab maintenance versus withdrawal groups ( P < .001). Of adalimumab nonresponders who switched to guselkumab, 66.1% achieved PASI 90 at week 48. Guselkumab improved patient-reported outcomes. Adverse events were comparable among groups. Limitations One-year follow-up limits retreatment data. Conclusions Guselkumab is a highly effective, well-tolerated, maintenance therapy, including in adalimumab nonresponders.
Metastasis of the cervical lymph nodes frequently leads to poor survival of patients with oral squamous cell carcinoma (OSCC). The underlying mechanisms of lymph node metastasis are unclear. ...Wingless-type MMTV integration site family, member 5B (WNT5B), one component of the WNT signal pathway, was markedly up-regulated in OSCC sublines with high potential of lymphatic metastasis compared to that in OSCC cells with low nodal metastasis. Increased WNT5B mRNA was demonstrated in human OSCC tissues in comparison with adjacent non-tumorous tissues. Interestingly, the high level of WNT5B protein in serum was associated with lymph node metastasis in OSCC patients. Knockdown of WNT5B expression in OSCC sublines did not affect tumour growth but impaired lymph node metastasis and tumour lymphangiogenesis of orthotopic transplantation. Conditioned medium from WNT5B knockdown cells reduced the tube formation of lymphatic endothelial cells (LECs). In contrast, recombinant WNT5B enhanced the tube formation, permeability and migration of LECs. In LECs stained with phalloidin, the morphology of those treated with recombinant WNT5B changed from flat to spindle-like. Recombinant WNT5B also increased α-smooth muscle actin and inhibited the expression of vascular endothelial-cadherin but retained characteristics of endothelial cells. The results suggest that WNT5B functions in the partial endothelial-mesenchymal transition (EndoMT). Furthermore, WNT5B-induced tube formation was impaired in the LECs following the knockdown of EndoMT-related transcription factor, SNAIL or SLUG. The WNT5B-induced expression of Snail or Slug was abolished by IWR-1-endo and Rac1 inhibitors, which are involved in the WNT/β-catenin and planar cell polarity pathways, respectively. Collectively, the data suggest that WNT5B induces tube formation by regulating the expression of Snail and Slug proteins through activation of canonical and non-canonical WNT signalling pathways.
The main recent advances in Al-based amorphous alloys are discussed in three areas: crystallization behavior, glass-forming ability and minor alloying effects. First, as a brief introduction, the ...special features and structure-property relationships are presented for the Al-based amorphous alloys. The different models for the nucleation behaviors, such as phase separation model and the quenched-in nuclei model, are compared and evaluated. In addition, an overview is given for the effects of minor alloying additions on glass-forming ability (GFA) and the crystallization behavior in terms of the reported structural, thermodynamic, kinetic factors.
•Present features and structure-property relationships of Al-based amorphous alloys.•Different models for the nucleation behaviors are compared and evaluated.•Summarize the effects of minor alloying additions on GFA and crystallization.
Abstract Previous data demonstrate that traumatic brain injury (TBI) activates autophagy, and increases microtubule-associated protein 1 light chain 3 (LC3) immunostaining mainly in neurons. However, ...the role of autophagy in traumatic brain damage remains elusive. The aim of the present study was to investigate the autophagic mechanisms participating in traumatic brain injury. The autophagy inhibitors 3-methyladenine (3-MA) and bafliomycin A1 (BFA) were administered with a single i.c.v. injection before TBI. We first examined the protein levels of Beclin-1 and LC3 II, which have been found to promote autophagy previously. Immunoblotting analysis showed that 3-MA pretreatment reduced post-TBI Beclin-1 and LC3-II levels, and maintained p62/SQSTM1 (p62) levels. In addition, double immunolabeling showed that the increased punctate LC3-II dots colocalizing with Propidium Iodide (PI)-stained nuclei at 24 h after injury, were partially inhibited by 3-MA pretreatment. Furthermore, inhibition of autophagy could reduce TBI-induced cell injury assessed with i.p. injection of PI and lesion volume, and attenuate behavioral outcome evaluated by motor test and Morris water maze. The neuroprotective effects were associated with an inhibition on TBI-induced up-regulation of LC3, Beclin-1, cathepsin B, caspase-3 and the Beclin-1/Bcl-2 ratio. Taken together, these data imply that the autophagy pathway is involved in the pathophysiologic responses after TBI, and inhibition of this pathway may help attenuate traumatic damage and functional outcome deficits.
The electronic bandgap is an intrinsic property of semiconductors and insulators that largely determines their transport and optical properties. As such, it has a central role in modern device ...physics and technology and governs the operation of semiconductor devices such as p-n junctions, transistors, photodiodes and lasers. A tunable bandgap would be highly desirable because it would allow great flexibility in design and optimization of such devices, in particular if it could be tuned by applying a variable external electric field. However, in conventional materials, the bandgap is fixed by their crystalline structure, preventing such bandgap control. Here we demonstrate the realization of a widely tunable electronic bandgap in electrically gated bilayer graphene. Using a dual-gate bilayer graphene field-effect transistor (FET) and infrared microspectroscopy, we demonstrate a gate-controlled, continuously tunable bandgap of up to 250 meV. Our technique avoids uncontrolled chemical doping and provides direct evidence of a widely tunable bandgap-spanning a spectral range from zero to mid-infrared-that has eluded previous attempts. Combined with the remarkable electrical transport properties of such systems, this electrostatic bandgap control suggests novel nanoelectronic and nanophotonic device applications based on graphene.
Graphene is an optical material of unusual characteristics because of its linearly dispersive conduction and valence bands and the strong interband transitions. It allows broadband light-matter ...interactions with ultrafast responses and can be readily pasted to surfaces of functional structures for photonic and optoelectronic applications. Recently, graphene-based optical modulators have been demonstrated with electrical tuning of the Fermi level of graphene. Their operation bandwidth, however, was limited to about 1 GHz by the response of the driving electrical circuit. Clearly, this can be improved by an all-optical approach. Here, we show that a graphene-clad microfiber all-optical modulator can achieve a modulation depth of 38% and a response time of ∼2.2 ps, limited only by the intrinsic carrier relaxation time of graphene. This modulator is compatible with current high-speed fiber-optic communication networks and may open the door to meet future demand of ultrafast optical signal processing.
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