Global Impact of the COVID-19 Pandemic on Cerebral Venous Thrombosis and Mortality

Thanh N. Nguyen,Muhammad M. Qureshi,Piers Klein,Hiroshi Yamagami,Mohamad Abdalkader,Robert Mikulik,Anvitha Sathya,Ossama Yassin Mansour,Anna Czlonkowska,Hannah Lo,Thalia S. Field,Andreas Charidimou,So 대한뇌졸중학회 2022 Journal of stroke Vol.24 No.2

Background and Purpose Recent studies suggested an increased incidence of cerebral venous thrombosis (CVT) during the coronavirus disease 2019 (COVID-19) pandemic. We evaluated the volume of CVT hospitalization and in-hospital mortality during the 1st year of the COVID-19 pandemic compared to the preceding year. Methods We conducted a cross-sectional retrospective study of 171 stroke centers from 49 countries. We recorded COVID-19 admission volumes, CVT hospitalization, and CVT in-hospital mortality from January 1, 2019, to May 31, 2021. CVT diagnoses were identified by International Classification of Disease-10 (ICD-10) codes or stroke databases. We additionally sought to compare the same metrics in the first 5 months of 2021 compared to the corresponding months in 2019 and 2020 (ClinicalTrials.gov Identifier: NCT04934020). Results There were 2,313 CVT admissions across the 1-year pre-pandemic (2019) and pandemic year (2020); no differences in CVT volume or CVT mortality were observed. During the first 5 months of 2021, there was an increase in CVT volumes compared to 2019 (27.5%; 95% confidence interval [CI], 24.2 to 32.0; P<0.0001) and 2020 (41.4%; 95% CI, 37.0 to 46.0; P<0.0001). A COVID-19 diagnosis was present in 7.6% (132/1,738) of CVT hospitalizations. CVT was present in 0.04% (103/292,080) of COVID-19 hospitalizations. During the first pandemic year, CVT mortality was higher in patients who were COVID positive compared to COVID negative patients (8/53 [15.0%] vs. 41/910 [4.5%], P=0.004). There was an increase in CVT mortality during the first 5 months of pandemic years 2020 and 2021 compared to the first 5 months of the pre-pandemic year 2019 (2019 vs. 2020: 2.26% vs. 4.74%, P=0.05; 2019 vs. 2021: 2.26% vs. 4.99%, P=0.03). In the first 5 months of 2021, there were 26 cases of vaccine-induced immune thrombotic thrombocytopenia (VITT), resulting in six deaths. Conclusions During the 1st year of the COVID-19 pandemic, CVT hospitalization volume and CVT in-hospital mortality did not change compared to the prior year. COVID-19 diagnosis was associated with higher CVT in-hospital mortality. During the first 5 months of 2021, there was an increase in CVT hospitalization volume and increase in CVT-related mortality, partially attributable to VITT.

A New Approach for Human-Robot Interaction Using Human Body Language

Nguyen-Duc-Thanh, N.,Stonier, D.,Lee, S.,Kim, D.-H. SPRINGER-VERLAG 2011 ICHIT 2012 Vol.6935 No.-

Study of Nanostructured Polymeric Composites and Hybrid Layers Used for Light-Emitting Diodes

N. N. Dinh,L. H. Chi,T. T. C. Thuy,D. V. Thanh,T. P. Nguyen 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

Nanocomposite polymeric thin lms of poly(2-methoxy-5-(2'-ethyl hexyloxy)phenylene vinylene) (MEH-PPV) with nano-crystalline titanium oxide (nc-TiO2) and polycarbazole (PVK) with cadmium selenide (CdSe) were fabricated by spin-coating. A 20-nm-thick nanocrystalline (molyb-denum oxide) MoO3 layer prepared by using thermal oxidation was also spin-coated with a PVK film. A study of photoluminescence (PL) spectra of the polymers and nanocomposites showed an enhancement in the photoluminescence from the nanocomposites. Moreover, MEH-PPV+nc-TiO2 composites exhibited a blue-shift of the PL spectrum as compared to that of the polymer film. The current-voltage characteristics of the Mo/nc-MoO3/PVK/Al-Au structures show that a semitransparent metallic coating or a transparent polymer can serve as a cathode in devices with enhanced charge carrier injection.

Magnetic and magnetocaloric properties of Ni-Ag-Mn-Sn ribbons and their composites

Thanh, Tran Dang,Duc, Nguyen Huu,Dan, Nguyen Huy,Mai, N.T.,Phan, T.L.,Oh, S.K.,Yu, Seong-Cho Elsevier 2017 Journal of Alloys and Compounds Vol.696 No.-

<P><B>Abstract</B></P> <P>In this work, we have investigated the influence of Ag-doping on the magnetic and magnetocaloric effect (MCE) of Ni<SUB>50-x</SUB>Ag<SUB>x</SUB>Mn<SUB>37</SUB>Sn<SUB>13</SUB> ribbons with <I>x</I> = 1, 2, and 4, which were prepared by a melt-spinning method. With increasing Ag concentration, a systematic decrease in the antiferromagnetic interaction and in the magnetic phase transition temperatures was observed. Analyses of the critical behavior based on the Banerjee criterion and scaling hypothesis for <I>M</I>(<I>H</I>, <I>T</I>) data near the ferromagnetic-paramagnetic transformation prove an increase of Ag favors establishing long-range ferromagnetic interactions in the austenitic phase. The temperature and magnetic field dependences of magnetic entropy change, Δ<I>S</I> <SUB>m</SUB>(<I>T</I>, <I>H</I>) were investigated via isothermal magnetization measurements. Interestingly, these samples exhibit a MCE at room-temperature with the Δ<I>S</I> <SUB>m</SUB>(<I>T</I>) curves distributed over a quite wide temperature range. To enhance the relative cooling power (RCP) value and to extend the magnetic phase transition region, we have prepared the composites in the form of the layered material samples based on ribbons obtained above. Under Δ<I>H</I> = 10 kOe, the maximum value of Δ<I>S</I> <SUB>m</SUB> (denoted as |Δ<I>S</I> <SUB>max</SUB>|) at around room-temperature is 1.08 J kg<SUP>−1</SUP> K<SUP>−1</SUP>, corresponding to RCP = 51.8 J kg<SUP>−1</SUP>, which is about 10% higher than that obtained from a separate sample. Additionally, we also pointed out that the dependences of |Δ<I>S</I> <SUB>max</SUB>| on Δ<I>H</I> at around room-temperature for samples obey a power law, |Δ<I>S</I> <SUB>max</SUB>| = <I>a</I> × Δ<I>H</I> <SUP>n</SUP>, and all the Δ<I>S</I> <SUB>m</SUB>(<I>T</I>, <I>H</I>) data obey completely a universal master curve.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An increase of Ag in Ni<SUB>1-x</SUB>Ag<SUB>x</SUB>Mn<SUB>37</SUB>Sn<SUB>13</SUB> ribbons favors establishing long-range FM order in the austenitic phase. </LI> <LI> High magnetic entropy change, wide operative temperature range, and high RCP value around room-temperature. </LI> <LI> The composite of Ni<SUB>1-x</SUB>Ag<SUB>x</SUB>Mn<SUB>37</SUB>Sn<SUB>13</SUB> ribbons exhibits higher RCP value and extends the magnetic phase transition region. </LI> <LI> Field dependence of |Δ<I>S</I> <SUB>max</SUB>| can be expressed by the power law. </LI> <LI> All the Δ<I>S</I> <SUB>m</SUB>(<I>T, H</I>) data around room temperature are followed a universal master curve. </LI> </UL> </P>

Deep Learning Approaches to Human Gait Pattern Classification Based On MEMS Sensors

My N. Nguyen,Hai Thanh Nguyen 대한전자공학회 2020 IEIE Transactions on Smart Processing & Computing Vol.9 No.4

Body motion is essential to our daily lives, and partly reflects our health. With the ubiquitous spread of mobile and wearable devices having built-in micro-electro-mechanical system (MEMS) sensors, acquisition of linear acceleration and angular velocity of personal gait is much easier today. These data can reveal different types of human movement as well as possible abnormalities. This study introduces an approach to collecting and processing human gait data, transforming these data into images and leveraging deep learning technique for the classification task. Features of three-dimensional linear acceleration are re-orientated and decomposed into various frequency components and characteristic waveforms by Zao and Lu method. Then, the summary of these characteristic waveforms produces a feature data set with four classes of human gait motion: walking, jogging, climbing upstairs, and going downstairs. We show promising results with the use of a convolutional neural network and a traditional neural network on the refined feature data. From this study, applications such as tele-monitoring, tele-rehabilitation, and assessing sedentary habits can be implemented to diagnose and intervene in human behavior.

Reduced Graphene Oxide Field-effect Transistor as a Transducer for Ion Sensing Application

T. N. T. Nguyen,Nguyen Thanh Tien,Tran Quang Trung,N.-E. Lee 한국진공학회 2012 한국진공학회 학술발표회초록집 Vol.2012 No.2

Monsoonal sediment transport along the subaqueous Mekong Delta: An analysis of surface sediment grain-size changes

Thanh C., Nguyen,An T., Dang,Khuong N.T., Tran Techno-Press 2022 Ocean systems engineering Vol.12 No.4

Annually, about 48-60% of sediment discharge of the Mekong River is delivered near the mouths of the Mekong River branches which is mostly coinciding with the southwest (SW) monsoon. This sediment budget in turn will be southwestwardly transported along the coast of the Mekong Delta (MD) during the northeast (NE) monsoon. Analysis of monsoonal changes in grain-size distribution (GSD) of surface sediment contributes to a better understanding of erosion and deposition processes along the MD. This study aims to figure out changes in GSD and sediment textures along the MD between SW and NE monsoons based on 183 surficial sediment samples collected along the MD during two field surveys carried-out in October 2016 and February-March 2017. Compared to the GSD during the SW and NE monsoon, the GSD along the MD changed significantly, especially in the estuary areas and along the coast of Bac Lieu and Ganh Hao. Whereas, in the west coast of the MD, GSD seem no changes between the two seasons. These changes in seabed sediment suggest that sediment with grain-sizes ranging from silt to fine sand can be transported during only a NE season.

An efficient approach for model updating of a large-scale cable-stayed bridge using ambient vibration measurements combined with a hybrid metaheuristic search algorithm

Tran N. Hoa,S. Khatir,G. De Roeck,Nguyen N. Long,Bui T. Thanh,M. Abdel Wahab 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.4

This paper proposes a novel approach to model updating for a large-scale cable-stayed bridge based on ambient vibration tests coupled with a hybrid metaheuristic search algorithm. Vibration measurements are carried out under excitation sources of passing vehicles and wind. Based on the measured structural dynamic characteristics, a finite element (FE) model is updated. For long-span bridges, ambient vibration test (AVT) is the most effective vibration testing technique because ambient excitation is freely available, whereas a forced vibration test (FVT) requires considerable efforts to install actuators such as shakers to produce measurable responses. Particle swarm optimization (PSO) is a famous metaheuristic algorithm applied successfully in numerous fields over the last decades. However, PSO has big drawbacks that may decrease its efficiency in tackling the optimization problems. A possible drawback of PSO is premature convergence leading to low convergence level, particularly in complicated multi-peak search issues. On the other hand, PSO not only depends crucially on the quality of initial populations, but also it is impossible to improve the quality of new generations. If the positions of initial particles are far from the global best, it may be difficult to seek the best solution. To overcome the drawbacks of PSO, we propose a hybrid algorithm combining GA with an improved PSO (HGAIPSO). Two striking characteristics of HGAIPSO are briefly described as follows: (1) because of possessing crossover and mutation operators, GA is applied to generate the initial elite populations and (2) those populations are then employed to seek the best solution based on the global search capacity of IPSO that can tackle the problem of premature convergence of PSO. The results show that HGAIPSO not only identifies uncertain parameters of the considered bridge accurately, but also outperforms than PSO, improved PSO (IPSO), and a combination of GA and PSO (HGAPSO) in terms of convergence level and accuracy.

Raman spectroscopy of pH-induced release of zidovudine from lactobionic acid-conjugated PEGylated gold colloids

Ly, Nguyễ,n Hoà,ng,Nguyen, Thanh Danh,Joo, Sang-Woo Elsevier 2018 Colloids and surfaces Biointerfaces Vol.171 No.-

<P><B>Abstract</B></P> <P>Zidovudine (AZT) adsorbed on colloidal gold nanoparticles (AuNPs) undergoes pH-induced conformational changes according to spectral changes in surface-enhanced Raman scattering (SERS). In acidic pH values conditions, AZT assumes the C<SUB>(2ʹ)</SUB>-endo conformer, which binds more weakly to AuNPs than under neutral and alkaline conditions. In this study, density functional theory (DFT) calculations were performed; these calculations also supported the conformation-dependent binding energies. A lactobionic acid-conjugated PEGylated (LA-PEG-SH; molecular weight: 3400) unit was attached to AuNPs to target the asialoglycoprotein receptors overexpressed in hepatocarcinoma cells of Huh7 and SNU-354. The loading efficiency values were measured to be ∼44–49% and ∼66–68% at pH values of 7 and 10, respectively. At an acidic pH of 4.5, they were estimated to be only ∼35–38%. pH-dependent spectral changes were observed for the asymmetric stretching modes of the azide (NNN) bands at 2183 cm<SUP>−1</SUP> (in acidic pH) and at 2129 cm<SUP>−1</SUP> (in basic pH). Cell viability analysis indicated that the LA-PEG-capped, AZT-coated AuNPs specifically inhibited the growth of the targeted hepatocarcinoma cells with better cancer cell killing efficiency than was observed with the LA-PEG-capped AuNPs without AZT.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Zidovudine bound to colloidal gold nanoparticles undergoes pH-induced conformational changes. </LI> <LI> At acidic pH values, zidovudine assumes the C<SUB>(2ʹ)</SUB>-endo conformer, which binds weakly to gold. </LI> <LI> Cytotoxicity analysis indicated that the complex could inhibit the growth of the targeted hepatocarcinoma cells. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Conformational change-induced drug release of zidovudine from gold nanoparticles in acidic pH conditions was studied by Raman spectroscopy and density functional theory.</P> <P>[DISPLAY OMISSION]</P>

Inhomogeneous Ferromagnetism and Spin-Glass-Like Behavior in <inline-formula> <tex-math notation='TeX'> <tex> $({\rm Nd}_{1-x}{\rm Y}_{x})_{0.7}{\rm Sr}_{0.3}{\rm MnO}_{3}$ </tex> </tex-math></inline-formula> With <inline-formula> <tex-math notation='TeX

Phan, T. L.,Nguyen, V. D.,Ho, T. A.,Khiem, N. V.,Thanh, T. D.,Phuc, N. X.,Thang, P. D.,Yu, S. C. IEEE 2014 IEEE transactions on magnetics Vol.50 No.6

<P>The magnetic properties of polycrystalline ceramic samples (Nd1-xYx)(0.7)Sr0.3MnO3 with x = 0.21 - 0.35 were studied by means of dc magnetization and ac susceptibility measurements. Experimental results reveal a strong decrease of the ferromagnetic (FM)-paramagnetic phase-transition temperature (T-C) from 97 to 65 K as increasing x from 0.21 to 0.35, respectively. There is magnetic inhomogeneity associated with short-range FM order. Particularly, the samples undergo a spin-glass (SG) phase transition at the so-called blocking temperature (T-B) below T-C, which shifts toward lower temperatures with increasing the applied field, Hex; T-B -> T-g (the SG phase-transition temperature) as H-ex -> 0. The existence of the SG behavior in these samples was also confirmed by frequency (f) dependences of the ac susceptibility. For the in-phase/real component, chi' (T), it shows a frequency-dependent peak at the SG freezing temperature (T-f); T-f -> T-g as f -> 0. Dynamics of this process were analyzed by means of the slowing down scaling law, tau/tau(0) proportional to (T-f/T-g - 1)(-zv), where tau(0) and zv are the characteristic time and critical exponent, respectively. Fitting the experimental T-f(f) data to the scaling law gave the results of zv = 10.1-12.3 and tau(0) = 10(-21)-10(-15)s. These values are different from those expected for canonical SG systems with zv = 10 and tau(0) = 10(-13)s, revealing the cluster-SG behavior of (Nd1-xYx)(0.7)Sr0.3MnO3 samples. Notably, the increase in Y content leads to the shift of tau(0) and zv values toward those of canonical SG systems, which is ascribed to an expansion of SG clusters.</P>