257 research outputs found
The Framework for the Prediction of the Critical Turning Period for Outbreak of COVID-19 Spread in China based on the iSEIR Model
The goal of this study is to establish a general framework for predicting the
so-called critical Turning Period in an infectious disease epidemic such as the
COVID-19 outbreak in China early this year. This framework enabled a timely
prediction of the turning period when applied to Wuhan COVID-19 epidemic and
informed the relevant authority for taking appropriate and timely actions to
control the epidemic. It is expected to provide insightful information on
turning period for the world's current battle against the COVID-19 pandemic.
The underlying mathematical model in our framework is the individual
Susceptible-Exposed- Infective-Removed (iSEIR) model, which is a set of
differential equations extending the classic SEIR model. We used the observed
daily cases of COVID-19 in Wuhan from February 6 to 10, 2020 as the input to
the iSEIR model and were able to generate the trajectory of COVID-19 cases
dynamics for the following days at midnight of February 10 based on the updated
model, from which we predicted that the turning period of CIVID-19 outbreak in
Wuhan would arrive within one week after February 14. This prediction turned to
be timely and accurate, providing adequate time for the government, hospitals,
essential industry sectors and services to meet peak demands and to prepare
aftermath planning. Our study also supports the observed effectiveness on
flatting the epidemic curve by decisively imposing the Lockdown and Isolation
Control Program in Wuhan since January 23, 2020. The Wuhan experience provides
an exemplary lesson for the whole world to learn in combating COVID-19.Comment: 24 paages, 9 figures, 10 table
Inverse Correlation Between Plasma Adropin and ET-1 Levels in Essential Hypertension: A Cross-Sectional Study
Adropin is a recently identified bioactive protein that promotes energy homeostasis by affecting glucose and lipid metabolism. Recently, adropin has also been reported to be associated with endothelial dysfunction. Also, ET-1, as a biomarker for endothelial dysfunction, is a key regulator in hypertension. Accordingly, the aim of the present study was to detect the relationship between plasma adropin and ET-1 levels in hypertension. A total of 123 participants, diagnosed with primary hypertension on the basis of World Health Organization criteria (systolic blood pressure [SBP] ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg), and 58 normotensive subjects were enrolled in the cross-sectional study from October 2011 to December 2013. All study participants were older than 18 years of age. Adropin and ET-1 levels were measured by enzyme-linked immunosorbent assay (ELISA). We found that plasma adropin levels were significantly lower in hypertensives compared with controls (3.18 ± 1.00 vs 4.21 ± 1.14 ng/mL, P \u3c 0.001). Plasma ET-1 levels were higher in hypertensives than controls (2.60 ± 1.14 vs 1.54 ± 0.66 pg/mL, P \u3c 0.001). Adropin had a negative correlation with DBP (r = -0.40, P \u3c 0.001), SBP (r = -0.49, P \u3c 0.001), and adjusted for age, body mass index, SBP, DBP, glucose, TC, TG, LDL, and Cr, there was a negative correlation between ET-1 and adropin (r = -0.20, P = 0.04). In multivariate logistic regression analysis of the variables, ET-1 (odds ratio [OR], 3.84; 95% CI, 2.16-6.81; P \u3c 0.001) and adropin (OR, 0.99; 95% CI, 0.99 -1.0; P \u3c  .001) were found to be independent predictors for hypertension.In conclusion, decreased plasma adropin levels are associated with increased blood pressure in hypertension. Adropin is an independent predictor for hypertension, and may influence blood pressure by protecting endothelial function
Observation of a thermoelectric Hall plateau in the extreme quantum limit
The thermoelectric Hall effect is the generation of a transverse heat current
upon applying an electric field in the presence of a magnetic field. Here we
demonstrate that the thermoelectric Hall conductivity in the
three-dimensional Dirac semimetal ZrTe acquires a robust plateau in the
extreme quantum limit of magnetic field. The plateau value is independent of
the field strength, disorder strength, carrier concentration, or carrier sign.
We explain this plateau theoretically and show that it is a unique signature of
three-dimensional Dirac or Weyl electrons in the extreme quantum limit. We
further find that other thermoelectric coefficients, such as the thermopower
and Nernst coefficient, are greatly enhanced over their zero-field values even
at relatively low fields.Comment: 17+21 pages, 3+14 figures; published versio
A proteome map of primary cultured rat Schwann cells
<p>Abstract</p> <p>Background</p> <p>Schwann cells (SCs) are the principal glial cells of the peripheral nervous system with a wide range of biological functions. SCs play a key role in peripheral nerve regeneration and are involved in several hereditary peripheral neuropathies. The objective of this study was to gain new insight into the whole protein composition of SCs.</p> <p>Results</p> <p>Two-dimensional liquid chromatography coupled with tandem mass spectrometry (2D LC-MS/MS) was performed to identify the protein expressions in primary cultured SCs of rats. We identified a total of 1,232 proteins, which were categorized into 20 functional classes. We also used quantitative real time RT-PCR and Western blot analysis to validate some of proteomics-identified proteins.</p> <p>Conclusion</p> <p>We showed for the first time the proteome map of SCs. Our data could serve as a reference library to provide basic information for understanding SC biology.</p
Challenges and Opportunities for Second-life Batteries: A Review of Key Technologies and Economy
Due to the increasing volume of Electric Vehicles in automotive markets and
the limited lifetime of onboard lithium-ion batteries (LIBs), the large-scale
retirement of LIBs is imminent. The battery packs retired from Electric
Vehicles still own 70%-80% of the initial capacity, thus having the potential
to be utilized in scenarios with lower energy and power requirements to
maximize the value of LIBs. However, spent batteries are commonly less reliable
than fresh batteries due to their degraded performance, thereby necessitating a
comprehensive assessment from safety and economic perspectives before further
utilization. To this end, this paper reviews the key technological and economic
aspects of second-life batteries (SLBs). Firstly, we introduce various
degradation models for first-life batteries and identify an opportunity to
combine physics-based theories with data-driven methods to establish
explainable models with physical laws that can be generalized. However,
degradation models specifically tailored to SLBs are currently absent.
Therefore, we analyze the applicability of existing battery degradation models
developed for first-life batteries in SLB applications. Secondly, we
investigate fast screening and regrouping techniques and discuss the regrouping
standards for the first time to guide the classification procedure and enhance
the performance and safety of SLBs. Thirdly, we scrutinize the economic
analysis of SLBs and summarize the potentially profitable applications.
Finally, we comprehensively examine and compare power electronics technologies
that can substantially improve the performance of SLBs, including
high-efficiency energy transformation technologies, active equalization
technologies, and technologies to improve reliability and safety
Overlapping Mechanisms of Peripheral Nerve Regeneration and Angiogenesis Following Sciatic Nerve Transection
Peripheral nervous system owns the ability of self-regeneration, mainly in its regenerative microenvironment including vascular network reconstruction. More recently, more attentions have been given to the close relationship between tissue regeneration and angiogenesis. To explore the overlap of molecular mechanisms and key regulation molecules between peripheral nerve regeneration and angiogenesis post peripheral nerve injury, integrative and bioinformatic analysis was carried out for microarray data of proximal stumps after sciatic nerve transection in SD rats. Nerve regeneration and angiogenesis were activated at 1 day immediately after sciatic nerve transection simultaneously. The more obvious changes of transcription regulators and canonical pathways suggested a phase transition between 1 and 4 days of both nerve regeneration and angiogenesis after sciatic nerve transection. Furthermore, 16 differentially expressed genes participated in significant biological processes of both nerve regeneration and angiogenesis, a few of which were validated by qPCR and immunofluorescent staining. It was demonstrated that STAT3, EPHB3, and Cdc42 co-expressed in Schwann cells and vascular endothelial cells to play a key role in regulation of nerve regeneration and angiogenesis simultaneously response to sciatic nerve transection. We provide a framework for understanding biological processes and precise molecular correlations between peripheral nerve regeneration and angiogenesis after peripheral nerve transection. Our work serves as an experimental basis and a valuable resource to further understand molecular mechanisms that define nerve injury-induced micro-environmental variation for achieving desired peripheral nerve regeneration
MicroRNA-483 amelioration of experimental pulmonary hypertension.
Endothelial dysfunction is critically involved in the pathogenesis of pulmonary arterial hypertension (PAH) and that exogenously administered microRNA may be of therapeutic benefit. Lower levels of miR-483 were found in serum from patients with idiopathic pulmonary arterial hypertension (IPAH), particularly those with more severe disease. RNA-seq and bioinformatics analyses showed that miR-483 targets several PAH-related genes, including transforming growth factor-β (TGF-β), TGF-β receptor 2 (TGFBR2), β-catenin, connective tissue growth factor (CTGF), interleukin-1β (IL-1β), and endothelin-1 (ET-1). Overexpression of miR-483 in ECs inhibited inflammatory and fibrogenic responses, revealed by the decreased expression of TGF-β, TGFBR2, β-catenin, CTGF, IL-1β, and ET-1. In contrast, inhibition of miR-483 increased these genes in ECs. Rats with EC-specific miR-483 overexpression exhibited ameliorated pulmonary hypertension (PH) and reduced right ventricular hypertrophy on challenge with monocrotaline (MCT) or Sugen + hypoxia. A reversal effect was observed in rats that received MCT with inhaled lentivirus overexpressing miR-483. These results indicate that PAH is associated with a reduced level of miR-483 and that miR-483 might reduce experimental PH by inhibition of multiple adverse responses
- …