Lattice strain effects on the optical properties of MoS2 nanosheets.

"Strain engineering" in functional materials has been widely explored to tailor the physical properties of electronic materials and improve their electrical and/or optical properties. Here, we exploit both in plane and out of plane uniaxial tensile strains in MoS2 to modulate its band gap and engineer its optical properties. We utilize X-ray diffraction and cross-sectional transmission electron microscopy to quantify the strains in the as-synthesized MoS2 nanosheets and apply measured shifts of Raman-active modes to confirm lattice strain modification of both the out-of-plane and in-plane phonon vibrations of the MoS2 nanosheets. The induced band gap evolution due to in-plane and out-of-plane tensile stresses is validated by photoluminescence (PL) measurements, promising a potential route for unprecedented manipulation of the physical, electrical and optical properties of MoS2

Transition routes of electrokinetic flow in a divergent microchannel with bending walls

Electrokinetic flow can be generated as a highly coupled phenomenon among velocity field, electric conductivity field and electric field. It can exhibit different responses to AC electric fields in different frequency regimes, according to different instability/receptivity mechanisms. In this investigation, by both flow visualization and single-point laser-induced fluorescence (LIF) method, the response of AC electrokinetic flow and the transition routes towards chaos and turbulence have been experimentally investigated. It is found, when the AC frequency $f_f<30$ Hz, the interface responds at both the neutral frequency of the basic flow and the AC frequency. However, when $f_f>=30$ Hz, the interface responds only at the neutral frequency of the basic flow. Both periodic doubling and subcritical bifurcations have been observed in the transition of AC electrokinetic flow. We hope the current investigation can promote our current understanding on the ultrafast transition process of electrokinetic flow from laminar state to turbulence

Electrokinetic origin of swirling flow on nanoscale interface

The zeta ($\zeta$) potential is a pivotal metric for characterizing the electric field topology within an electric double layer - an important phenomenon on phase interface. It underpins critical processes in diverse realms such as chemistry, biomedical engineering, and micro/nanofluidics. Yet, local measurement of $\zeta$ potential at the interface has historically presented challenges, leading researchers to simplify a chemically homogenized surface with a uniform $\zeta$ potential. In the current investigation, we present evidence that, within a microchannel, the spatial distribution of $\zeta$ potential across a chemically homogeneous solid-liquid interface can become two-dimensional (2D) under an imposed flow regime, as disclosed by a state-of-art fluorescence photobleaching electrochemistry analyzer (FLEA) technique. The $\zeta$ potential' s propensity to become increasingly negative downstream, presents an approximately symmetric, V-shaped pattern in the spanwise orientation. Intriguingly, and of notable significance to chemistry and engineering, this 2D $\zeta$ potential framework was found to electrokinetically induce swirling flows in tens of nanometers, aligning with the streamwise axis, bearing a remarkable resemblance to the well-documented hairpin vortices in turbulent boundary layers. Our findings gesture towards a novel perspective on the genesis of vortex structures in nanoscale. Additionally, the FLEA technique emerges as a potent tool for discerning $\zeta$ potential at a local scale with high resolution, potentially accelerating the evolution and applications of novel surface material

Use of Radiomics Combined With Machine Learning Method in the Recurrence Patterns After Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma: A Preliminary Study

Objective: To analyze the recurrence patterns and reasons in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT) and to investigate the feasibility of radiomics for analysis of radioresistance.Methods: We analyzed 306 NPC patients treated with IMRT from Jul-2009 to Aug-2016, 20 of whom developed with recurrence. For the NPCs with recurrence, CT, MR, or PET/CT images of recurrent disease were registered with the primary planning CT for dosimetry analysis. The recurrences were defined as in-field, marginal or out-of-field, according to dose-volume histogram (DVH) of the recurrence volume. To explore the predictive power of radiomics for NPCs with in-field recurrences (NPC-IFR), 16 NPCs with non-progression disease (NPC-NPD) were used for comparison. For these NPC-IFRs and NPC-NPDs, 1117 radiomic features were quantified from the tumor region using pre-treatment spectral attenuated inversion-recovery T2-weighted (SPAIR T2W) magnetic resonance imaging (MRI). Intraclass correlation coefficients (ICC) and Pearson correlation coefficient (PCC) was calculated to identify influential feature subset. Kruskal-Wallis test and receiver operating characteristic (ROC) analysis were employed to assess the capability of each feature on NPC-IFR prediction. Principal component analysis (PCA) was performed for feature reduction. Artificial neural network (ANN), k-nearest neighbor (KNN), and support vector machine (SVM) models were trained and validated by using stratified 10-fold cross validation.Results: The median follow up was 26.5 (range 8–65) months. 9/20 (45%) occurred in the primary tumor, 8/20 (40%) occurred in regional lymph nodes, and 3/20 (15%) patients developed a primary and regional failure. Dosimetric and target volume analysis of the recurrence indicated that there were 18 in-field, and 1 marginal as well as 1 out-of-field recurrence. With pre-therapeutic SPAIR T2W MRI images available, 11 NPC-IFRs (11 of 18 NPC-IFRs who had available pre-therapeutic MRI) and 16 NPC-NPDs were subsequently employed for radiomic analysis. Results showed that NPC-IFRs vs. NPC-NPDs could be differentiated by 8 features (AUCs: 0.727–0.835). The classification models showed potential in prediction of NPC-IFR with higher accuracies (ANN: 0.812, KNN: 0.775, SVM: 0.732).Conclusion: In-field and high-dose region relapse were the main recurrence patterns which may be due to the radioresistance. After integration in the clinical workflow, radiomic analysis can be served as imaging biomarkers to facilitate early salvage for NPC patients who are at risk of in-field recurrence

Analysis of factors influencing health-related quality of life in patients with femoropopliteal atherosclerotic occlusive disease treated with drug-coated balloons 12 months after surgery

BackgroundPatients with femoropopliteal (FP) occlusive disease encounter considerable obstacles concerning health-related quality of life (HRQoL), which serve as the primary objectives of their interventions. While Drug-Coated Balloons (DCBs) present potential advantages, they are not constitute definitive cures. There is a paucity of research concerning postoperative HRQoL in these patients. This study evaluates HRQoL 12 months post-DCB treatment and examines influencing risk factors through a multicenter cross-sectional study.MethodsThis retrospective, multicenter study involved 1012 patients with FP occlusive disease who underwent DCB at 8 vascular centers from August 2021 to December 2023. Data on initial hospitalizations and 12-month follow-up were gathered, and logistic regression was utilized to examine the influencing factors.ResultsAccording to the median HRQoL at 12 months postoperatively, patients were categorized into low (N = 503) and high (N = 509) HRQoL groups. Significant differences were found in several variables such as renal insufficiency, calcification degree and TLR incidence (P &lt; 0.05), while intervention approach (P = 0.781), DCB diameter (P = 0.301) and DCB length (P = 0.368) showed no significant differences. Logistic regression demonstrated that arterial calcification (OR = 0.33–0.44, P &lt; 0.001), postoperative Rutherford classification (grade 1–6, OR = 0.0000 to 0.0367, P &lt; 0.001), the Rutherford classification progression within 12 months (OR = 9.53, P &lt; 0.001), and target lesion revascularization (TLR) occurrence (OR = 0.09, P = 0.011) were significantly linked to HRQoL at 12 months postoperatively, with no significant differences for other factors.ConclusionsOverall, the Rutherford classification progression over 12 months was significantly positively linked to HRQoL 12 months postoperatively. Conversely, HRQoL was notably diminished in patients who exhibited arterial calcification, elevated postoperative Rutherford classification, and experienced TLR. Nevertheless, intervention approach, DCB length and diameter had no significant relationship to postoperative HRQoL

Combination of Decitabine and a Modified Regimen of Cisplatin, Cytarabine and Dexamethasone: A Potential Salvage Regimen for Relapsed or Refractory Diffuse Large B-Cell Lymphoma After Second-Line Treatment Failure

ObjectiveThe prognosis for patients with relapsed or refractory diffuse large B-cell lymphoma (R/R-DLBCL) after second-line treatment failure is extremely poor. This study prospectively observed the efficacy and safety of decitabine with a modified cisplatin, cytarabine, and dexamethasone (DHAP) regimen in R/R-DLBCL patients who failed second-line treatment.MethodsTwenty-one R/R-DLBCL patients were enrolled and treated with decitabine and a modified DHAP regimen. The primary endpoints were overall response rate (ORR) and safety. The secondary endpoints were progression-free survival (PFS) and overall survival (OS).ResultsORR reached 50% (complete response rate, 35%), five patients (25%) had stable disease (SD) with disease control rate (DCR) of 75%. Subgroup analysis revealed patients over fifty years old had a higher complete response rate compared to younger patients (P = 0.005), and relapsed patients had a better complete response rate than refractory patients (P = 0.031). Median PFS was 7 months (95% confidence interval, 5.1-8.9 months). Median OS was not achieved. One-year OS was 59.0% (95% CI, 35.5%-82.5%), and two-year OS was 51.6% (95% confidence interval, 26.9%-76.3%). The main adverse events (AEs) were grade 3/4 hematologic toxicities such as neutropenia (90%), anemia (50%), and thrombocytopenia (70%). Other main non-hematologic AEs were grade 1/2 nausea/vomiting (40%) and infection (50%). No renal toxicity or treatment-related death occurred.ConclusionDecitabine with a modified DHAP regimen can improve the treatment response and prognosis of R/R-DLBCL patients with good tolerance to AEs, suggesting this regimen has potential as a possible new treatment option for R/R-DLBCL patients after second-line treatment failure.Clinical Trial RegistrationClinicalTrials.gov, identifier: NCT03579082

Modélisation numérique d’impacts à hautes vitesses par la méthode sans maillage Smoothed Particles Hydrodynamics. Application aux micro-impacts dans des tissus mous.

Investigations on the ballistic behaviours of soft tissue materials are significant research in a medical and pharmaceutical framework. They mainly focus on particles penetrating or traveling into the soft materials. For instance, in the needle-free drug delivery, the micro-scale particles as drug powders are injected into skin with high velocity, and several factors should be considered such as the particle diameters, trajectories, and momentum or velocities of projectile in this process. There have been investigated by some experiments, but there is still no study from the numerical insights.The numerical methods are suitable to study these kinds of processes. Although grid-based methods like FEM have been powerful tools in engineering, the large distortions of elementsexist when solid structures are extremely deformed. The methods based on the particle modelling are very suitable for simulating phenomena like the high velocity impacts. As the earliest meshless method, Smoothed Particles Hydrodynamics (SPH) has been applied in solid dynamics because of its great potentials in simulating extremely large deformation and perforation of targets by various projectiles at high velocities. This thesis mainly studies the SPH method by developing a SPH code for solid dynamics, and then propose a numerical model based on SPH method to investigate the penetration process into soft tissues (gelatin and synthetic polymer SEBS gel (styrene-ethylene-butylene-styrene) considered as biofidelic soft tissue simulants) at micro-scale.Résumé : L’étude sur les impacts à hautes vitesses dans les tissus mous constituent un des pans de la recherche en biomécanique des chocs, et peuvent avoir des applications importantes en médecine, que ce soit à l’échelle microscopique ou macroscopique. La perforation d’un projectile dans les tissus mous doit être compris, à l’échelle macroscopique, pour analyser un impact ballistique perforant par exemple, mais également à plus petite échelle, avec l’administration de particules médicamenteuses à hautes vitesses au travers de différents tissus, comme la peau, en prenant en compte différents paramètres du phénomène, comme la vitesse d’impact ou la taille du projectile.Un des moyens efficace pour comprendre ces phénomènes à très hautes vitesses est la simulation numérique. Les modèles numériques doivent être alors validés par rapport à des tests expérinentaux permettant de s’assurer de leurs biofidélités.Bien que les méthodes basées sur unmaillage comme la méthode des éléments finis sont des outils puissante, les grandes distorsions des éléments tels qu’ils peuvent apparaître lors d’impacts pénétrant génèrent des erreurs numériques importantes. Ainsi, des méthodes sans maillage baséessur une modélisation particulaire s’affranchissant de toutes grillessont très adaptées pour simuler à hautes vitesses et grandes déformations. Un des plus anciennes méthode, la méthode SPH (Smoothed Particles Hydrodynamics) a été appliquée, dans cette thèse à la mécanique du solide en grandes vitesses et grandes déformations. Cette thèse s’attache à étudier la méthode SPH en développant un code “maison” pour ls impacts perforants ou non, puis propose un modèle numérique pour étudier le processus de pénétration de projectiles dans les tissus mous (la gélatine et le polymère synthétique gel SEBS sont considérés dans la litérature comme des substituts de tissus biofidèles) à échelle micrométrique

Design and Implementation of a Two-Wheeled Self-Balancing Car Using a Fuzzy Kalman Filter

To improve the upright balancing performance of the two-wheeled self-balancing car, this paper proposes an attitude estimation algorithm based on fuzzy Kalman filtering. Fuzzy logic is used to correct the inclination angle and angular velocity of the two-wheeled self-balancing car, thereby optimizing the state of the Kalman filter and ultimately improving the balancing performance of the car. This paper combines dual closed-loop PID control with the complementary filtering algorithm, Kalman filtering algorithm, and fuzzy Kalman filtering algorithm to conduct experiments on a physical two-wheeled self-balancing car. The experimental results validate the superiority of the fuzzy Kalman filtering algorithm proposed in this paper for improving the upright balancing performance of the two-wheeled self-balancing car