Mechanics of leukemic T-cell.

Cell mechanics is a factor that determines cell growth, migration, proliferation, or differentiation, as well as trafficking inside the cytoplasm and organization of organelles. Knowledge about cell mechanics is critical to gaining insight into these biological processes. Here, we used atomic force microscopy to examine the elasticity, an important parameter of cell mechanics, of non-adherent Jurkat leukemic T-cells in both interphase and mitotic phases. We found that the elasticity of an individual cell does not significantly change at interphase. When a cell starts to divide, its elasticity increases in the transition from metaphase to telophase during normal division while the cell is stiffened right after it enters mitosis during abnormal division. At the end of the division, the cell elasticity gradually returned to the value of the mother cell. These changes may originate from the changes in cell surface tension during modulating actomyosin at the cleavage furrow, redistributing cell organelles, and constricting the contractile ring to sever mother cell to form daughters. The difference in elasticity patterns suggests that there is a discrepancy in the redistribution of the cell organelles during normal and abnormal division.

Cytotoxic and Anti-Inflammatory Activity of 3,19-Isopropylidene-/Arylidene-Andrographolide Analogs.

A series of 3,19-isopropylidene-/or arylidene-andrographolide analogs were synthesized and their structures were confirmed by NMR spectroscopic methodology. Twenty-five analogs were evaluated for their in vitro cytotoxic activity against HT-29, HepG2 and LNCaP cancer cell lines based on the sulforhodamine B (SRB) assay. Analog 2 f exhibited the most potent cytotoxic activity, with IC50 values of 11.14 and 9.25 µM on HepG2 and LNCaP cancer cell lines, respectively. Esterification of hydroxy functional group at position C-14 in andrographolide analogs, 2 a and 2 b, showed somewhat higher cytotoxicity than the precursor. In addition, andrographolide analogs (2 a-2 d, 2 f, 3 a, 4 a and 4 h) were evaluated for the NO inhibitory activity in the LPS stimulated RAW264.7 macrophages. The most active analog 2 a significantly reduced nitric oxide (NO) production from LPS stimulated RAW264.7 cells, with IC50 values of 0.34±0.02 µM providing encouraging results for anti-inflammatory compound development.

Bayesian merging of numerical modeling and remote sensing for saltwater intrusion quantification in the Vietnamese Mekong Delta.

Saltwater intrusion has become one of the most concerning issues in the Vietnamese Mekong Delta (VMD) due to its increasing impacts on agriculture and food security of Vietnam. Reliable estimation of salinity plays a crucial role to mitigate the impacts of saltwater intrusion. This study developed a hybrid technique that merges satellite imagery with numerical simulations to improve the estimation of salinity in the VMD. The salinity derived from Landsat images and by numerical simulations was fused using the Bayesian inference technique. The results indicate that our technique significantly reduces the uncertainties and improves the accuracy of salinity estimates. The Nash-Sutcliffe coefficient is 0.74, which is much higher than that of numerical simulation (0.63) and Landsat estimation (0.6). The correlation coefficient between the ensemble and measured salinity is relatively high (0.88). The variance of the ensemble salinity errors (5.0 ppt2) is lower than that of Landsat estimation (10.4 ppt2) and numerical simulations (9.6 ppt2). The proposed approach shows a great potential to combine multiple data sources of a variable of interest to improve its accuracy and reliability wherever these data are available.

On the Performance of Underlay Device-to-Device Communications.

This paper comprehensively investigates the performance of the D2D underlaying cellular networks where D2D communications are operated concurrently with cellular networks provided that the aggregate interference measured on licensed users is strictly guaranteed. In particular, we derive the outage probability (OP), the average rate, and the amount of fading (AoF) of the D2D networks in closed-form expressions under three distinct power allocation schemes, i.e., the path-loss-based, equal, and random allocation schemes. It is noted that the considered networks take into consideration the impact of the intra-D2D networks, the inter-interference from the cellular networks and background noise, thus involving many random variables and leading to a complicated mathematical framework. Moreover, we also reveal the behavior of the OP with respect to the transmit power based on the rigorous mathematical frameworks rather than the computer-based simulation results. The derived framework shows that increasing the transmit power is beneficial for the OP of the D2D users. Regarding the cellular networks, the coverage probability (Pcov) of the cellular users is computed in closed-form expression too. Monte Carlo simulations are given to verify the accuracy of the proposed mathematical frameworks. Our findings illustrate that the power allocation method based on prior path-loss information outperforms the other methods in the average sum rate.

Assessment of the distribution and ecological risks of heavy metals in coastal sediments in Vietnam's Mong Cai area.

Coastal sediments in the Mong Cai area were collected and analyzed for grain size, heavy metals, total organic carbon, and isotopes (210Pb, 226Ra, δ15N, δ13C) to assess sediment quality. The most common sediments were fine sand in surface sediment, very fine sand in core C1, and very coarse and coarse silt in core C2. The total organic carbon was highest in C2 next to the surface and lowest in C1, with content levels of 1.81%, 0.40%, and 0.31%, respectively. The chronology in C1 was 1877-2019 (142 years, 0-5 0 cm), with an average sedimentation rate of 0.71 cm/year. In C2, the chronology was 1944-2019 (75 years, 0-14 cm), with an average sedimentation rate of 0.27 cm/year. These δ13C and δ15N in the sediment reflect the source of the organic matter mix from the marine and terrigenous sediments. All studied heavy metals were lower than the ISQGs, with the exception of As in C1 and C2, which were higher. C1 showed a decline in As over time, while C2 As levels increased between 1996 and 2019. In terms of heavy metal pollution indexes, the geoaccumulation index (Igeo) showed that C1 and C2 were unpolluted to moderately polluted with As, with Li and Pb in C2; the enrichment factor (EF) was moderately enriched with As; the contamination factor (CF) was moderately contaminated (Pb, Cd, Fe, Mo, and Li) in C2 and C1 (Cd, As, Li) and considerably contaminated (As) in C2. The risk factor (ER) of As showed a moderate potential ecological risk in C2. The degree of contamination (CD) ranged from moderate to considerable (C1, C2), and the ecological risk (RI) was low. Although CD ranged from moderate (C1) to considerable (C2), most contamination was concentrated at the bottom of the cores. RI was low. The Mong Cai sediment quality does not currently affect the coastal area's ecosystem and fauna.

A simple and efficient ultrasonic-assisted electrochemical approach for scalable production of nitrogen-doped TiO2nanocrystals.

In this study, we report a facile and effective approach for large-scale production of nitrogen-doped TiO2nanocrystals (UNTs) by a combination of ultrasonic irradiation and electrochemistry at room temperature using NH4NO3electrolyte as the nitrogen source. The as-prepared UNTs were then characterized by x-ray diffraction, Raman spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV-visible diffuse reflectance spectroscopy. The results indicated that the nitrogen content of UNTs reached 9.3% and bandgap energy of 2.62 eV, thus gave the high photocatalytic degradation of methylene blue under visible light irradiation. The mechanism for the formation of UNTs by ultrasonic-assisted electrochemical approach was also proposed.

Machine Learning-Based 5G-and-Beyond Channel Estimation for MIMO-OFDM Communication Systems.

Channel estimation plays a critical role in the system performance of wireless networks. In addition, deep learning has demonstrated significant improvements in enhancing the communication reliability and reducing the computational complexity of 5G-and-beyond networks. Even though least squares (LS) estimation is popularly used to obtain channel estimates due to its low cost without any prior statistical information regarding the channel, this method has relatively high estimation error. This paper proposes a new channel estimation architecture with the assistance of deep learning in order to improve the channel estimation obtained by the LS approach. Our goal is achieved by utilizing a MIMO (multiple-input multiple-output) system with a multi-path channel profile for simulations in 5G-and-beyond networks under the level of mobility expressed by the Doppler effects. The system model is constructed for an arbitrary number of transceiver antennas, while the machine learning module is generalized in the sense that an arbitrary neural network architecture can be exploited. Numerical results demonstrate the superiority of the proposed deep learning-based channel estimation framework over the other traditional channel estimation methods popularly used in previous works. In addition, bidirectional long short-term memory offers the best channel estimation quality and the lowest bit error ratio among the considered artificial neural network architectures.

Dragon Fruit Foliage: An Agricultural Cellulosic Source to Extract Cellulose Nanomaterials.

In this report, we focus our effort to extract cellulose nanomaterials (CNs) from an agricultural cellulosic waste, Dragon Fruit foliage (DFF). DFF was first pretreated by several mechanical treatments and then bleached by chemical treatment to obtain bleached DFF. CNs were then produced from the hydrolysis of the bleached DFF catalyzed by sulfuric acid. We obtained CNs with a small diameter (50 to 130 nm) and length (100 to 500 nm) and a height of 3 to 10 nm. The CNs have a high crystallinity (crystallinity index 84.8%), high -COOH content (0.74 mmol·g-1), good thermal stability and a good Cu (II) adsorption capacity with an adsorption maximum of ~103 mg·g-1. These findings demonstrated the great potential of converting many agricultural cellulosic wastes into valuable cellulose nanomaterials.

Direct monitoring of drug-induced mechanical response of individual cells by atomic force microscopy.

Mechanical characteristics of individual cells play a vital role in many biological processes and are considered as indicators of the cells' states. Disturbances including methyl-ß-cyclodextrin (MßCD) and cytochalasin D (cytoD) are known to significantly affect the state of cells, but little is known about the real-time response of single cells to these drugs in their physiological condition. Here, nanoindentation-based atomic force microscopy (AFM) was used to measure the elasticity of human embryonic kidney cells in the presence and absence of these pharmaceuticals. The results showed that depletion of cholesterol in the plasma membrane with MßCD resulted in cell stiffening whereas depolymerization of the actin cytoskeleton by cytoD resulted in cell softening. Using AFM for real-time measurements, we observed that cells mechanically responded right after these drugs were added. In more detail, the cell´s elasticity suddenly increased with increasing instability upon cholesterol extraction while it is rapidly decreased without changing cellular stability upon depolymerizing actin cytoskeleton. These results demonstrated that actin cytoskeleton and cholesterol contributed differently to the cell mechanical characteristics.

Biophysical characteristics of hematopoietic cells during division.

Cell division is managed by a complex and coordinated sequence of cytoskeleton alterations that give rise to major morphological changes. During dividing the cleavage furrow of the cell is significantly stiffened due to the accumulation of actomyosin. However, it is unclear whether the stiffness on top of the cell is changed or not. Here, we used atomic force microscopy to measure stiffness on this location of non-adhesion Jurkat T cell and its derivative D1.1 cell from interphase to cytokinesis. The results showed that during division the cell stiffness significantly increases at anaphase and telophase. These increases in cell stiffness are most likely due to the cell surface tension created by the pulling forces of the microtubules to separate sister chromatids in the anaphase and the contraction forces of the contractile ring to separate the mother cell into daughters in the telophase. The dynamic measurement of cell elasticity during cell division may be used as a tool to gain further insight into the involved molecules and mechanisms.

DNA aggregation induced by Mg2+ ions under different conditions.

Cations-induced DNA aggregation can modify the local structure of oligonucleotides and has potential applications in medicine and biotechnology. Here, we used atomic force microscopy to investigate λ-DNA aggregation on Mg2+ -treated glass (Mg2+ /glass) and in Mg2+ solution. Atomic force microscopy topography images showed that some DNA fragments were slightly stacked together on 10 mM Mg2+ /glass and stacked stronger on ≥50 mM Mg2+ /glass. They also showed that DNA aggregated stronger in Mg2+ solution than on Mg2+ /glass, ie, DNAs are strongly stacked and twisted at 10 mM Mg2+ , rolled together at 50 mM Mg2+ , and slightly aggregated to form small particles at 100 mM Mg2+ . At a specific condition, ie, heating λ-DNA to 92°C, cooling down to 75°C, adding Mg2+ , and vortexing the resulting solution, DNA strongly aggregated and formed pancake-like shapes at 10 and 50 mM or a large aggregate at 100 mM Mg2+ solutions. Our results may be helpful for medical applications and gene therapy using cation-DNA technology.

New cycloartanes and new iridoids from Dolichandrone spathacea collected in the mangrove forest of Soc Trang province, Vietnam.

Two new cycloartanes, named dolichandrone A (1) and dolichandrone B (2), as well as two new iridoids, named [6-O-[(E)-4-methoxycinnamoyl]-1ß-hydroxy-dihydrocatalpolgenin (3) and 6-O-[(E)-4-methoxycinnamoyl]-1α-hydroxy-dihydrocatalpolgenin (4), together with four known iridoids (5-8), were isolated from the leaves and barks of Dolichandrone spathacea. Their structures were elucidated by means of extensive analysis of their HRESIMS, 1D and 2D NMR spectroscopic data. All of these compounds have been isolated for the first time from this plant. Compounds 1, 2, 5, and 7 were evaluated for their cytotoxic activity in vitro against four human cancer cell lines KB, Lu, HepG2, and MCF7. The results showed that only compound 2 exhibited a good cytotoxicity against KB cell line with IC50 of 18.77 µM.

The Role of Single-Molecule Force Spectroscopy in Unraveling Typical and Autoimmune Heparin-induced Thrombocytopenia.

For the last two decades, heparins have been widely used as anticoagulants. Besides numerous advantages, up to 5% patients with heparin administration suffer from a major adverse drug effect known as heparin-induced thrombocytopenia (HIT). This typical HIT can result in deep vein thrombosis, pulmonary embolism, occlusion of a limb artery, acute myocardial infarct, stroke, and a systemic reaction or skin necrosis. The basis of HIT may lead to clinical insights. Recent studies using single-molecule force spectroscopy (SMFS)-based atomic force microscopy revealed detailed binding mechanisms of the interactions between platelet factor 4 (PF4) and heparins of different lengths in typical HIT. Especially, SMFS results allowed identifying a new mechanism of the autoimmune HIT caused by a subset of human-derived antibodies in patients without heparin exposure. The findings proved that not only heparin but also a subset of antibodies induce thrombocytopenia. In this review, the role of SMFS in unraveling a major adverse drug effect and insights into molecular mechanisms inducing thrombocytopenia by both heparins and antibodies will be discussed.

Macrocyclic analogues of the diuretic insect neuropeptide helicokinin I show strong receptor-binding.

Helicokinin I, a diuretic neuropeptide of the relevant cotton pest Helicoverpa zea represents a promising target for the design of insect neuropeptide mimetics. Using a ring-closing metathesis reaction, N-terminal bridged macrocyclic helicokinin I analogues with different rigidity were prepared and tested in a helicokinin receptor assay. A partially peptidomimetic helicokinin analogue, containing two structural modifications provides a deeper insight into the structural-requirements for receptor-binding.

Successful Chemotherapy Treatment for a Tricuspid Valvular Stenosis Patient due to Right Ventricular Lymphoma.

Background: This study presents a patient diagnosed with tricuspid valvular stenosis due to right ventricular lymphoma, who was treated successfully. Case presentation: A 66-year-old man with a history of worsening shortness of breath during activity for the last three weeks sought medical attention. The patient later experienced swelling in the extremities, fluid build-up around the lungs and abdominal fluid accumulation, with no reported chest pain, fever, or weight loss. An echocardiogram found a mass in the lateral wall near the tricuspid valve of the right ventricle, leading to moderate tricuspid stenosis. The cardiac magnetic resonance imaging (MRI) revealed a lumpy, poorly defined mass that invaded the heart muscle and displayed varied enhancement after contrast administration. Suspicion arose for a malignant tumour or metastatic lesion due to its features and contrast uptake capability. A percutaneous biopsy was carried out on the mass in the right ventricle to confirm the diagnosis. The pathology report indicated a diagnosis of non-Hodgkin's lymphoma. After being diagnosed, the patient underwent chemotherapy using the R-CHOP regimen. Over time the symptoms improved, and echocardiograms revealed a decrease in the size of the tumour. After undergoing six rounds of chemotherapy, a cardiac MRI four months later showed no signs of a tumour. After that, the patient resumed their regular activities. Conclusion: Right ventricular tumours are mostly malignant lesions and often have an inferior prognosis. Early diagnosis with imaging techniques and myocardial biopsy is necessary to deliver life-saving treatment quickly. LEARNING POINTS: Right ventricular tumours are mostly malignant lesions and often have an inferior prognosis.Early diagnosis with imaging techniques and myocardial biopsy is necessary to deliver life-saving treatment quickly.Right ventricular lymphoma is a sporadic tumour, but the prognosis is favourable if detected in time.

A novel flood risk management approach based on future climate and land use change scenarios.

Climate change and increasing urbanization are two primary factors responsible for the increased risk of serious flooding around the world. The prediction and monitoring of the effects of land use/land cover (LULC) and climate change on flood risk are critical steps in the development of appropriate strategies to reduce potential damage. This study aimed to develop a new approach by combining machine learning (namely the XGBoost, CatBoost, LightGBM, and ExtraTree models) and hydraulic modeling to predict the effects of climate change and LULC change on land that is at risk of flooding. For the years 2005, 2020, 2035, and 2050, machine learning was used to model and predict flood susceptibility under different scenarios of LULC, while hydraulic modeling was used to model and predict flood depth and flood velocity, based on the RCP 8.5 climate change scenario. The two elements were used to build a flood risk assessment, integrating socioeconomic data such as LULC, population density, poverty rate, number of women, number of schools, and cultivated area. Flood risk was then computed, using the analytical hierarchy process, by combining flood hazard, exposure, and vulnerability. The results showed that the area at high and very high flood risk increased rapidly, as did the areas of high/very high exposure, and high/very high vulnerability. They also showed how flood risk had increased rapidly from 2005 to 2020 and would continue to do so in 2035 and 2050, due to the dynamics of climate change and LULC change, population growth, the number of women, and the number of schools - particularly in the flood zone. The results highlight the relationships between flood risk and environmental and socio-economic changes and suggest that flood risk management strategies should also be integrated in future analyses. The map built in this study shows past and future flood risk, providing insights into the spatial distribution of urban area in flood zones and can be used to facilitate the development of priority measures, flood mitigation being most important.

The Binding of the SARS-CoV-2 Spike Protein to Platelet Factor 4: A Proposed Mechanism for the Generation of Pathogenic Antibodies.

Pathogenic platelet factor 4 (PF4) antibodies contributed to the abnormal coagulation profiles in COVID-19 and vaccinated patients. However, the mechanism of what triggers the body to produce these antibodies has not yet been clarified. Similar patterns and many comparable features between the COVID-19 virus and heparin-induced thrombocytopenia (HIT) have been reported. Previously, we identified a new mechanism of autoimmunity in HIT in which PF4-antibodies self-clustered PF4 and exposed binding epitopes for other pathogenic PF4/eparin antibodies. Here, we first proved that the SARS-CoV-2 spike protein (SP) also binds to PF4. The binding was evidenced by the increase in mass and optical intensity as observed through quartz crystal microbalance and immunosorbent assay, while the switching of the surface zeta potential caused by protein interactions and binding affinity of PF4-SP were evaluated by dynamic light scattering and isothermal spectral shift analysis. Based on our results, we proposed a mechanism for the generation of PF4 antibodies in COVID-19 patients. We further validated the changes in zeta potential and interaction affinity between PF4 and SP and found that their binding mechanism differs from ACE2-SP binding. Importantly, the PF4/SP complexes facilitate the binding of anti-PF4/Heparin antibodies. Our findings offer a fresh perspective on PF4 engagement with the SARS-CoV-2 SP, illuminating the role of PF4/SP complexes in severe thrombotic events.

Two Cases of Management of Coronary Artery Perforation During Percutaneous Coronary Intervention Using Injection of Combined Histoacryl (n-Butyl-2-Cyanoacrylate) and Lipiodol (Ethiodized Oil).

BACKGROUND Coronary artery perforation is a rare complication of percutaneous coronary intervention for coronary artery occlusion. This report is of 2 cases of coronary artery perforation during percutaneous coronary intervention that were managed successfully using injection of combined Histoacryl (n-Butyl-2-Cyanoacrylate) and Lipiodol (ethiodized oil). CASE REPORT Case 1 was a 51-year-old man with a past medical history of hypertension, dyslipidemia, and multivessel coronary disease. He was admitted to our hospital with inferior wall myocardial infarction, and a stent was placed in the proximal right coronary artery. He also had chronic total occlusion (CTO) of the left anterior descending artery (LAD). The planned LAD CTO intervention was complicated by balloon-induced coronary perforation and was managed successfully with intracoronary injection of Histoacryl-Lipiodol mixtures via microcatheter. He was discharged in stable condition without any serious consequences. Case 2 was a 72-year-old man with underlying hypertension who was admitted to the hospital with diagnosis of unstable angina. The diagnostic angiography showed occlusion of the LAD, CTO of the left circumflex artery, and minor atherosclerosis in right coronary artery. A stent was placed in the mid-LAD without any complications. Subsequently, a planned left circumflex artery CTO intervention was complicated by wire-induced coronary perforation, which was treated successfully with injection of Histoacryl-Lipiodol mixture. The patient was discharged in good condition. CONCLUSIONS Histoacryl and Lipiodol injection was a rapid and effective management method in 2 rare cases of coronary artery perforation during percutaneous coronary intervention.

Soil salinity prediction using hybrid machine learning and remote sensing in Ben Tre province on Vietnam's Mekong River Delta.

Soil salinization is considered one of the disasters that have significant effects on agricultural activities in many parts of the world, particularly in the context of climate change and sea level rise. This problem has become increasingly essential and severe in the Mekong River Delta of Vietnam. Therefore, soil salinity monitoring and assessment are critical to building appropriate strategies to develop agricultural activities. This study aims to develop a low-cost method based on machine learning and remote sensing to map soil salinity in Ben Tre province, which is located in Vietnam's Mekong River Delta. This objective was achieved by using six machine learning algorithms, including Xgboost (XGR), sparrow search algorithm (SSA), bird swarm algorithm (BSA), moth search algorithm (MSA), Harris hawk optimization (HHO), grasshopper optimization algorithm (GOA), particle swarm optimization algorithm (PSO), and 43 factors extracted from remote sensing images. Various indices were used, namely, root mean square error (RMSE), mean absolute error (MAE), and the coefficient of determination (R2) to estimate the efficiency of the prediction models. The results show that six optimization algorithms successfully improved XGR model performance with an R2 value of more than 0.98. Among the proposed models, the XGR-HHO model was better than the other models with a value of R2 of 0.99 and a value of RMSE of 0.051, by XGR-GOA (R2 = 0.931, RMSE = 0.055), XGR-MSA (R2 = 0.928, RMSE = 0.06), XGR-BSA (R2 = 0.926, RMSE = 0.062), XGR-SSA (R2 = 0.917, 0.07), XGR-PSO (R2 = 0.916, RMSE = 0.08), XGR (R2 = 0.867, RMSE = 0.1), CatBoost (R2 = 0.78, RMSE = 0.12), and RF (R2 = 0.75, RMSE = 0.19), respectively. These proposed models have surpassed the reference models (CatBoost and random forest). The results indicated that the soils in the eastern areas of Ben Tre province are more saline than in the western areas. The results of this study highlighted the effectiveness of using hybrid machine learning and remote sensing in soil salinity monitoring. The finding of this study provides essential tools to support farmers and policymakers in selecting appropriate crop types in the context of climate change to ensure food security.