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"Zhou, Zhong"
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Bound-state solitons in three-wave resonant interactions
Three-wave resonant interactions are commonly observed in the dispersive and weakly nonlinear media in fluid mechanics, plasma physics, nonlinear optics, solid-state physics, Bose–Einstein condensates and acoustics. This paper investigates a three-wave resonant interaction system in the one-dimensional space-time form. For that system of the soliton-exchange case, a Lax pair is introduced. Then, we utilize the generalized Darboux transformation method to derive the semi-rational solutions depicting the bound-state dark–bright mixed solitons. The three wave packets can manifest themselves as the bound-state bright–dark–bright solitons on the zero–nonzero–zero background, and bound-state dark–bright–bright solitons on the nonzero–zero–zero background. The bound states between the bright/dark solitons exhibit periodic attractions and repulsions, while the bound states among the bright/dark solitons and multi-pole bright/dark solitons exhibit non-periodic attractions and repulsions. We explore how the phase shift of the single bright/dark soliton component affects the bound states among a single bright/dark soliton and the double-pole bright/dark solitons. All the results obtained for the one-dimensional space-time evolution can be reinterpreted in terms of the two-dimensional steady-state interaction. This work may provide explanations for the complex and variable natural mechanisms of three-wave resonant interactions in various physical contexts.
Journal Article
بعد النھایة : انتهى العرض والجمهور لم يغادر : (رواية)
لو كان لديك مسرح فلتلعب دورك على أكمل وجه وان لم يكن لديك مسرح فاد تكن مجرد متفرج رواية نصف سياسية نصف فلسفية ظاهرها يحمل استقصاء لحياة حاكم ما وباطنها يجسد علاقات مجتمعية وعاطفية متشابكة ومعقدة كما هي حياتنا جميعا رجل مات يعاد إحياؤه بعيون 26 مقابلة مع بعض من كانوا قريبين منه 26 رؤية مختلفة لرجل واحد و26 رواية متباينة للحدث نفسه رواية تحمل أحلام وهموم الصين وتراجيديا الحياة كل حياة.
Book
Comparison of ARIMA and GM(1,1) models for prediction of hepatitis B in China
Hepatitis B virus (HBV) infection is a major public health threat in China for China has a hepatitis B prevalence of more than one million people in 2017 year. Disease incidence prediction may help hepatitis B prevention and control. This study intends to build and compare 2 forecasting models for hepatitis B incidence in China.
Autoregressive integrated moving average (ARIMA) model and grey model GM(1,1) were adopted to fit the monthly incidence of hepatitis B in China from March 2010 to October 2017. The fitting and forecasting performances of the 2 models were evaluated. The better one was adopted to predict the incidence from November 2017 to March 2018. Database was built by Excel 2016 and statistical analysis was completed using R 3.4.3 software.
Descriptive analysis showed that the incidence of hepatitis B in China has seasonal variation and has shown a downward trend from 2010 to 2017. We selected the ARIMA (3,1,1) (0,1,2)12 model among all the ARIMA models for it has the lowest AIC value. Model expression of GM (1,1) was X(1) (k + 1) = 3386876.7478e0.0249k - 3289206.7428. The root mean square error (RMSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) of ARIMA(3,1,1)(0,1,2)12 model were lower than GM(1,1) model on fitting part and forecasting part. According to the forecast results, the incidence may have a slight fluctuation during the following months.
The ARIMA model showed better hepatitis B fitting and forecasting performance than GM(1,1) model. It is a potential decision supportive tool for controlling hepatitis B in China before a predictive hepatitis B outbreak.
Journal Article
Nonlinear waves behaviors for a coupled generalized nonlinear Schrödinger–Boussinesq system in a homogeneous magnetized plasma
Under investigation in this paper is a coupled generalized nonlinear Schrödinger–Boussinesq system, which describes the coupled upper-hybrid and magnetoacoustic modes in a homogeneous magnetized plasma for the bidirectional propagation near the magnetoacoustic speed. Based on the Hirota method, the expressions for the multi-soliton solutions are given. Effects of the group velocity, group dispersion coefficient for the upper-hybrid, and the properties of the magnetic field on the soliton are discussed. Based on the asymptotic analysis, interaction between two solitons is proved to be elastic through the asymptotic analysis. Position at which the maximal distortion occurs is obtained. Multi-soliton interaction is illustrated and investigated. Two prerequisites of the formation and features of the bound state are discussed. For the cases of three solitons, inelastic interaction occurs with phase shifts. Characteristics of the breather and its relation with the bound state and the breather are investigated. Interaction between the bound state (even the breather) and a single soliton is discussed for both cases that they are parallel or not.
Journal Article
A Shortage of FTH Induces ROS and Sensitizes RAS-Proficient Neuroblastoma N2A Cells to Ferroptosis
Ferroptosis, an iron-dependent form of programmed cell death, has excellent potential as an anti-cancer therapeutic strategy in different types of tumors, especially in RAS-mutated ones. However, the function of ferroptosis for inhibiting neuroblastoma, a common child malignant tumor with minimal treatment, is unclear. This study investigated the anti-cancer function of ferroptosis inducer Erastin or RSL3 in neuroblastoma N2A cells. Our results show that Erastin or RSL3 induces ROS level and cell death and, therefore, reduces the viability of RAS-proficient N2A cells. Importantly, inhibitors to ferroptosis, but not apoptosis, ameliorate the high ROS level and viability defect in Erastin- or RSL3-treated cells. In addition, our data also show that N2A cells are much more sensitive to ferroptosis inducers than primary mouse cortical neural stem cells (NSCs) or neurons. Moreover, a higher level of ROS and PARylation is evidenced in N2A, but not NSCs. Mechanically, ferritin heavy chain 1 (Fth), the ferroxidase function to oxidate redox-active Fe2+ to redox-inactive Fe3+, is likely responsible for the hypersensitivity of N2A to ferroptosis induction since its expression is lower in N2A compared to NSCs; ectopic expression of Fth reduces ROS levels and cell death, and induces expression of GPX4 and cell viability in N2A cells. Most importantly, neuroblastoma cell lines express a significantly low level of Fth than almost all other types of cancer cell lines. All these data suggest that Erastin or RSL3 induce ferroptosis cell death in neuroblastoma N2A cells, but not normal neural cells, regardless of RAS mutations, due to inadequate FTH. This study, therefore, provides new evidence that ferroptosis could be a promising therapeutic target for neuroblastoma.
Journal Article
Artificial intelligence alphafold model for molecular biology and drug discovery: a machine-learning-driven informatics investigation
AlphaFold model has reshaped biological research. However, vast unstructured data in the entire AlphaFold field requires further analysis to fully understand the current research landscape and guide future exploration. Thus, this scientometric analysis aimed to identify critical research clusters, track emerging trends, and highlight underexplored areas in this field by utilizing machine-learning-driven informatics methods. Quantitative statistical analysis reveals that the AlphaFold field is enjoying an astonishing development trend (Annual Growth Rate = 180.13%) and global collaboration (International Co-authorship = 33.33%). Unsupervised clustering algorithm, time series tracking, and global impact assessment point out that Cluster 3 (Artificial Intelligence-Powered Advancements in AlphaFold for Structural Biology) has the greatest influence (Average Citation = 48.36 ± 184.98). Additionally, regression curve and hotspot burst analysis highlight “structure prediction” (s = 12.40, R
2
= 0.9480,
p
= 0.0051), “artificial intelligence” (s = 5.00, R
2
= 0.8096,
p
= 0.0375), “drug discovery” (s = 1.90, R
2
= 0.7987,
p
= 0.0409), and “molecular dynamics” (s = 2.40, R
2
= 0.8000,
p
= 0.0405) as core hotspots driving the research frontier. More importantly, the Walktrap algorithm further reveals that “structure prediction, artificial intelligence, molecular dynamics” (Relevance Percentage[RP] = 100%, Development Percentage[DP] = 25.0%), “sars-cov-2, covid-19, vaccine design” (RP = 97.8%, DP = 37.5%), and “homology modeling, virtual screening, membrane protein” (RP = 89.9%, DP = 26.1%) are closely intertwined with the AlphaFold model but remain underexplored, which implies a broad exploration space. In conclusion, through the machine-learning-driven informatics methods, this scientometric analysis offers an objective and comprehensive overview of global AlphaFold research, identifying critical research clusters and hotspots while prospectively pointing out underexplored critical areas.
Journal Article
Opening-up as entrepreneurial internationalisation in Chinese higher education
PurposeThis study describes and elucidates higher education internationalisation with an in-depth case study of China and its Tsinghua University using international entrepreneurship concepts. The study examines internationalisation as a dynamic reciprocal interplay between opening-up policy and higher education policy, especially world-class university policy.Design/methodology/approachThis is a qualitative mixed-method single case study. In desktop research, the study reviewed China's national policy documents on educational opening-up, Tsinghua's institutional strategy papers and research literature concerning internationalisation, entrepreneurship, Chinese higher education and Tsinghua University. In fieldwork research, the present researcher engaged in action, participatory and collaborative research about university internationalisation in her capacity as both a faculty and an international office administrator at Tsinghua.FindingsEntrepreneurial internationalisation in Chinese higher education has served multiple purposes simultaneously: (1) a pillar to support domestic confidence in educational opening-up for modernisation while also contributing to global development; (2) a cost-effective way to cultivate Chinese talent by accessing the international education market; (3) a quality imperative to stimulate domestic reform and innovation through Sino-foreign exchange and collaboration; (4) a public diplomacy measure building a global network of educational engagement; and (5) a differentiation strategy to stretch the capacity of the nation's top universities by benchmarking their global competitiveness.Originality/valueConceptualising opening-up as entrepreneurial internationalisation is key to understand China's higher education development. This study expounds this special term by connecting it with basic concepts in international entrepreneurship research. The analyses at system and institutional levels reinforce one another to forge a synthetic view by integrating policy and practice.
Journal Article
Solitary and rogue waves with controllable backgrounds for the non-autonomous generalized AB system
Investigated in this paper is a non-autonomous generalized
AB
system, which is used to describe certain baroclinic instability processes in the geophysical flows. We discover that the two short waves and mean flow can evolve in the forms of the multi-rogue waves on the condition that the nonlinearity effect
σ
is positive. Via the Darboux and generalized Darboux transformations, we obtain the first- and second-order rogue waves as well as the algorithm to derive the
N
th-order rogue waves. It is revealed that the perturbation function
δ
(
t
)
has no effect on the two short waves while affects the mean flow by changing its evolution background. When
σ
is negative, those rogue waves turn to be singular. In addition, we find that the two short waves and mean flow can also appear as the solitary waves, and they perform as the “bright” solitons under
σ
>
0
while perform as the “dark” solitons under
σ
<
0
. With the Hirota method, introducing the auxiliary function
α
(
t
)
, we derive the first- and second-order bright and dark solitary waves. Both solitary wave velocities are related to
δ
(
t
)
and
α
(
t
)
. Besides,
δ
(
t
)
and
α
(
t
)
have no effect on the amplitudes of the two short waves but bring about controllable backgrounds and deformations of the solitary waves for the mean flow.
Journal Article
Nsun2 coupling with RoRγt shapes the fate of Th17 cells and promotes colitis
T helper 17 (Th17) cells are a subset of CD4
+
T helper cells involved in the inflammatory response in autoimmunity. Th17 cells secrete Th17 specific cytokines, such as IL-17A and IL17-F, which are governed by the master transcription factor RoRγt. However, the epigenetic mechanism regulating Th17 cell function is still not fully understood. Here, we reveal that deletion of RNA 5-methylcytosine (m
5
C) methyltransferase Nsun2 in mouse CD4
+
T cells specifically inhibits Th17 cell differentiation and alleviates Th17 cell-induced colitis pathogenesis. Mechanistically, RoRγt can recruit Nsun2 to chromatin regions of their targets, including
Il17a
and
Il17f
, leading to the transcription-coupled m
5
C formation and consequently enhanced mRNA stability. Our study demonstrates a m
5
C mediated cell intrinsic function in Th17 cells and suggests Nsun2 as a potential therapeutic target for autoimmune disease.
Th17 cells produce a range of characteristic Th17 type cytokines and express transcription factors governed by epigenetic regulation to engage the Th17 programme. Here the authors implicate the RNA 5- methylcytosine (m
5
C) methyltransferase Nsun2 in Th17 cells and the promotion of colitis in a murine model.
Journal Article