Owing to the advantages of integration and being magnet-free and light-weight, the switched-capacitor-convertor plays an increasing role compared to traditional transformer in some specific power ...supply systems. However, the high output impedance and switching loss largely reduces its power efficiency, due to imperfect topology and transistors. Herein, we propose a fractal-design based switched-capacitor-convertors with characteristics including high conversion efficiency, minimum output impedance, and electrostatic voltage applicability. As a double-function output power management system for triboelectric nanogenerators, it delivers over 67 times charge boosting and 954 W m
power density in pulse mode, and achieves over 94% total energy transfer efficiency in constant mode. The establishment of the fractal-design switched-capacitor-convertors provides significant guidance for the development of power management toward multi-functional output for numerous applications. The successful demonstration in triboelectric nanogenerators also declares its great potential in electric vehicles, DC micro-grids etc.
Quantum gas microscopes have expanded the capabilities of quantum simulation of Hubbard models by enabling the study of spatial spin and density correlations in square lattices. However, quantum gas ...microscopes have not been realized for fermionic atoms in frustrated geometries. Here, we demonstrate the single-atom resolved imaging of ultracold fermionic ^{6}Li atoms in a triangular optical lattice with a lattice constant of 1003 nm. The optical lattice is formed by a recycled narrow-linewidth, high-power laser combined with a light sheet to allow for Raman sideband cooling on the D_{1} line. We optically resolve single atoms on individual lattice sites using a high-resolution objective to collect scattered photons while cooling them close to the two-dimensional ground vibrational level in each lattice site. By reconstructing the lattice occupation, we measure an imaging fidelity of approximately 98%. Our triangular lattice microscope platform for fermions clears the path for studying spin-spin correlations, entanglement, and dynamics of geometrically frustrated Hubbard systems which are expected to exhibit exotic emergent phenomena including spin liquids and kinetic frustration.
In this work, we constructed a Collagen I–Matrigel composite extracellular matrix (ECM). The composite ECM was used to determine the influence of the local collagen fiber orientation on the ...collective intravasation ability of tumor cells. We found that the local fiber alignment enhanced cell–ECM interactions. Specifically, metastatic MDA-MB-231 breast cancer cells followed the local fiber alignment direction during the intravasation into rigid Matrigel (∼10 mg/mL protein concentration).
This study investigates how deviation angles close to the 001 orientation affect the tensile properties and deformation behavior of a nickel-based single-crystal superalloy at room temperature. The ...research focuses on samples with deviation angles of 3°, 8°, and 13° from the 001 orientation and examines their strength and ductility. We employed scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) to explore the deformation micro-mechanisms at varying angles. Findings reveal that strength decreases and ductility increases as the deviation angle widens within the 001 vicinity. The study emphasizes that octahedral slip-driven crystal slip and rotation are crucial for understanding tensile deformation. The deformation differences in samples at varying angles are attributed to the differential engagement of mechanisms. Specifically, at lower angles, reduced ductility and increased strength are due to short lattice rotation paths and work hardening causing superlattice stacking faults (SSFs) to slip in two directions on the {111} plane within the γ' phase. As the angles increase, the lattice rotation paths extend, and Shockley partial dislocations (a/6 ) accumulate in γ channels. This process, involving SSFs moving in a single direction within the γ' phase, results in higher ductility and reduced strength.
Microvascular invasion (MVI) is regarded as one of the independent risk factors for recurrence and poor prognosis of hepatocellular carcinoma (HCC). The presence of MVI in HCCs was evaluated on the ...basis of pathological reports of surgical specimens and was defined as tumor within a vascular space lined by endothelium that was visible only on microscopy. The aim of the study was to investigate the usefulness of intravoxel incoherent motion (IVIM) diffusion weighted (DW) magnetic resonance (MR) imaging in predicting MVI of HCC. Preoperative IVIM DW imaging and Gd-EOB-DTPA-enhanced MRI (DCE-MRI) of 51 patients were analyzed. Standard apparent diffusion coefficient (ADC), D (the true diffusion coefficient), D* (the pseudodiffusion coefficient) and f (the perfusion fraction), relative enhancement (RE) and radiological features were evaluated and analyzed. Univariate analysis revealed that HCCs with MVI had a higher portion of an irregular tumor shape than HCCs without MVI (p = 0.009), the Standard ADC, D value were significantly lower in HCCs with MVI (p = 0.022, p = 0.007, respectively). Multivariate analysis revealed that an irregular shape (p = 0.012) and D value ≤ 1.16×10-3mm2/sec (p = 0.048) were independent predictors for MVI. Combining the two factors of an irregular shape and D value, a sensitivity of 94.4% and specificity of 63.6% for predicting MVI was obtained. In conclusion, we found that an irregular shape and D value ≤ 1.16×10-3mm2/sec may suggest the presence of MVI in HCCs.
Bacterial bloodstream infection is responsible for the majority of cases of sepsis and septic shock. Early recognition of the causative pathogen is pivotal for administration of adequate empiric ...antibiotic therapy and for the survival of the patients. In this study, we developed a feasible machine learning (ML) model to predict gram-positive and gram-negative bacteremia based on routine laboratory parameters. Data for 2118 patients with bacteremia were obtained from the Medical Information Mart for Intensive Care dataset. Patients were randomly split into the training set and test set by stratified sampling, and 374 routine laboratory blood test variables were retrieved. Variables with missing values in more than 40% of the patients were excluded. Pearson correlation test was employed to eliminate redundant features. Five ML algorithms were used to build the model based on the selected features. Additionally, 132 patients with bacteremia who were treated at Qilu Hospital of Shandong University were included in an independent test cohort to evaluate the model. After feature selection, 32 variables remained. All the five ML algorithms performed well in terms of discriminating between gram-positive and gram-negative bacteremia, but the performance of convolutional neural network (CNN) and random forest (RF) were better than other three algorithms. Consider of the interpretability of models, RF was chosen for further test (ROC-AUC = 0.768; 95%CI = 0.715-0.798, with a sensitivity of 75.20% and a specificity of 63.79%). To expand the application of the model, a decision tree (DT) was built utilizing the major variables, and it achieved an AUC of 0.679 (95%CI = 0.632-0.723), a sensitivity of 66%, and a specificity of 67.82% in the test cohort. When tested in the Qilu Hospital cohort, the ROC-AUC of the RF and DT models were 0.666 (95%CI = 0.579-0.746) and 0.615 (95%CI = 0.526-0.698), respectively. Finally, a software was developed to make the RF- and DT-based prediction models easily accessible. The present ML-based models could effectively discriminate between gram-positive and gram-negative bacteremia based on routine laboratory blood test results. This simple model would be beneficial in terms of guiding timely antibiotic selection and administration in critically ill patients with bacteremia before their pathogen test results are available.
Wearable devices integrated with various electronic modules, biological sensors, and chemical sensors have drawn large public attention. Due to their inherent advantages of superior stretchability, ...elaborate microstructure, high integration of multiple functions, and low cost, microfluidics are an excellent candidate and have already been widely used in wearable devices. Well‐designed microfluidic devices can realize excellent multiple functions in wearable devices, including sample collecting, handling and storage, sample analysis, signal converting and amplification, mechanic sensing, and power supplying. Moreover, the microfluidic wearable devices with further integration of wireless modules have exhibited potential applications in healthcare monitoring, clinical assessment, and human and intelligent device interaction. This review focuses on the latest advances on multifunctional wearable devices based on microfluidics, primarily including general functions and designs of microfluidic wearable devices, and their specific applications in physiological signal monitoring, clinical diagnosis and therapeutics, and healthcare.
Microfluidics are widely applied in wearable devices for their inherent advantages. In this review, the general functions and designs of microfluidic‐based wearable devices are summarized in detail. Additionally, some recent progress and main challenges of their applications in specific areas related to physiological signal monitoring, clinical diagnosis and therapeutics, and healthcare are introduced and discussed.
Correlated cell migration in fibrous extracellular matrix (ECM) is important in many biological processes. During migration, cells can remodel the ECM, leading to the formation of mesoscale ...structures such as fiber bundles. However, how such mesoscale structures regulate correlated single‐cells migration remains to be elucidated. Here, using a quasi‐3D in vitro model, we investigate how collagen fiber bundles are dynamically re‐organized and guide cell migration. By combining laser ablation technique with 3D tracking and active‐particle simulations, we definitively show that only the re‐organized fiber bundles that carry significant tensile forces can guide strongly correlated cell migration, providing for the first time a direct experimental evidence supporting that matrix‐transmitted long‐range forces can regulate cell migration and self‐organization. This force regulation mechanism can provide new insights for studies on cellular dynamics, fabrication or selection of biomedical materials in tissue repairing, and many other biomedical applications.
Collagen fibers are dynamically re‐organized by cells, and are able to transmit tensile force for precise cell‐communication at single‐cells level. This mechanism also explains the self‐organization of multiple cells in the quasi‐3D microenvironment.
This study explores the microstructure and coloration mechanism of high-saturation structural colors in ultra-thin oxide films formed on TC11 aerospace titanium alloy near permissible engineering ...temperatures. Utilizing optical microscopy (OM), spectrophotometry, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), focused ion beam (FIB), transmission electron microscopy (TEM), and energy dispersive spectrometer (EDS), the optical properties, thickness, and microstructure of the oxide films were examined. The research posits a coloration theory grounded in zero-order Fabry-Pérot resonance-enhanced absorption. Key findings reveal a color transition in the oxide films from golden to light blue as oxidation conditions vary from 450 °C for 5 h to 550 °C for 60 h, with an average thickness ranging from 16.3 nm to 63.4 nm. Despite changes in oxidation conditions, the film's structure remains consistent and uniform. It predominantly consists of Brookite-type TiO2, TiO and Al2O3, with trace amounts of MoO2 and MoO3. The film's color is independent of its structural composition and instead related to its thickness, influencing the absorption wavelength per the Fabry-Pérot model, which closely matches the observed absorption wavelengths. Notably, oxidation acceleration between 30 and 60 h at 550 °C heralds the commencement of a deviation from the coloration mechanism of the oxide film based on the Fabry-Pérot cavity.
Circulating tumor cells (CTCs) and circulating clusters of cancer and stromal cells have been identified in the blood of patients with malignant cancer and can be used as a diagnostic for disease ...severity, assess the efficacy of different treatment strategies and possibly determine the eventual location of metastatic invasions for possible treatment. There is thus a critical need to isolate, propagate and characterize viable CTCs and clusters of cancer cells with their associated stroma cells. Here, we present a microfluidic device for mL/min flow rate, continuous-flow capture of viable CTCs from blood using deterministic lateral displacement (DLD) arrays. We show here that a DLD array device can isolate CTCs from blood with capture efficiency greater than 85% CTCs at volumetric flow rates of up to 10 mL/min with no effect on cell viability.
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