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1.
Small ; : e2401877, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38837548

ABSTRACT

The efficiency and stability of solar cells are two key indicators that determine for the commercial feasibility of photovoltaic devices. Formamidine-cesium perovskite has been extensively investigated since its excellent thermal stability and has great potential in achieving high power conversion efficiency. However, during the aging process, especially under light conditions, formamidine-rich perovskites are prone to produce iodine, and the escape of iodine is one of the important factors leading to device degradation. Here, DL-Serine Hydrazide Hydrochloride containing the reducing group is introduced into the precursor solution of formamidine-cesium perovskite, which achieves multiple-site passivation. Hydrazine reacts with iodine to reduce it to iodine ions, inhibiting the escape of iodine. In addition, carbonyl groups and uncoordinated lead ions form coordination bonds to reduce defects. In the end, the perovskite solar cell with DL-Serine Hydrazide Hydrochloride added achieves a champion efficiency of 22.22%, and maintains 85.88% of the initial efficiency after continuous exposure under 1 sun for 7000 s at a relative humidity of ≈40%. Additionally, DL-Serine Hydrazide Hydrochloride added device shows good stability in air environments with relative humidity of 50%-60%. DL-Serine Hydrazide Hydrochloride improves the stability of formamidine-rich perovskite solar cells and provides a low-cost strategy for commercial development.

2.
Small ; : e2400179, 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39031523

ABSTRACT

With the rapid development of micro/nano machining, there is an elevated demand for high-performance microdevices with high reliability and low cost. Due to their outstanding electrochemical, optical, electrical, and mechanical performance, carbon materials are extensively utilized in constructing microdevices for energy storage, sensing, and optoelectronics. Carbon micro/nano machining is fundamental in carbon-based intelligent microelectronics, multifunctional integrated microsystems, high-reliability portable/wearable consumer electronics, and portable medical diagnostic systems. Despite numerous reviews on carbon materials, a comprehensive overview is lacking that systematically encapsulates the development of high-performance microdevices based on carbon micro/nano structures, from structural design to manufacturing strategies and specific applications. This review focuses on the latest progress in carbon micro/nano machining toward miniaturized device, including structural engineering, large-scale fabrication, and performance optimization. Especially, the review targets an in-depth evaluation of carbon-based micro energy storage devices, microsensors, microactuators, miniaturized photoresponsive and electromagnetic interference shielding devices. Moreover, it highlights the challenges and opportunities in the large-scale manufacturing of carbon-based microdevices, aiming to spark further exciting research directions and application prospectives.

3.
Mol Breed ; 43(5): 34, 2023 May.
Article in English | MEDLINE | ID: mdl-37312744

ABSTRACT

Japanese apricot (Prunus mume Sieb. et Zucc.) is a traditional woody flower and fruit tree restrictedly cultivated in northern area due to its inability to survive harsh winters and early springs. In the current study, RNA-seq and physiological assay were used to study the cold response of P. mume 'Xuemei'. A total of 4705 genes were identified as differentially expressed genes (DEGs) in the 21 pairwise comparisons among seven time points under 0 °C cold treatment, and 3678 of them showed differential levels compared with control at normal temperature. The gene expression profiles indicated that the number of upregulated genes increased with prolongation of treatment time throughout the whole 48 h. Hierarchical clustering suggested three obvious phases of the gene expression profiles. Gene ontology (GO) analysis of the 4705 DEGs resulted in 102 significantly enriched GO items in which the transcription activity was dominant. 225 DEGs were predicted to encode transcription factor (TF) genes. Some important TFs (ERF, CBF, WRKY, NAC, MYB, bHLH) were strongly induced during the whole cold treatment. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that plant signal transduction pathways such as plant hormone and calcium (Ca2+) were notable. Metabolic pathways such as sugar metabolism, especially RFOs (raffinose family oligosaccharides) were activated, which was accompanied by the accumulation of soluble sugars. SOD and POD enzyme activities coupled with reactive oxygen species (ROS)-related gene expression profile implied a gradually induced ROS scavenging system under cold treatment. These results might shed light on the sensitivity to cold stress in Japanese apricot and provide new insights into hardiness studies in P. mume and its related species. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-023-01376-2.

4.
Sensors (Basel) ; 23(11)2023 May 25.
Article in English | MEDLINE | ID: mdl-37299776

ABSTRACT

Sorts of Li-ion batteries (LIB) have been becoming important energy supply and storage devices. As a long-standing obstacle, safety issues are limiting the large-scale adoption of high-energy-density batteries. Strategies covering materials, cell, and package processing have been paid much attention to. Here, we report a flexible sensor array with fast and reversible temperature switching that can be incorporated inside batteries to prevent thermal runaway. This flexible sensor array consists of PTCR ceramic sensors combined with printed PI sheets for electrodes and circuits. Compared to room temperature, the resistance of the sensors soars nonlinearly by more than three orders of magnitude at around 67 °C with a 1 °C/s rate. This temperature aligns with the decomposition temperature of SEI. Subsequently, the resistance returns to normal at room temperature, demonstrating a negative thermal hysteresis effect. This characteristic proves advantageous for the battery, as it enables a lower-temperature restart after an initial warming phase. The batteries with an embedded sensor array could resume their normal function without performance compromise or detrimental thermal runaway.


Subject(s)
Ceramics , Electric Power Supplies , Temperature , Cell Movement , Electrodes , Ions , Lithium
5.
Sensors (Basel) ; 23(13)2023 Jun 26.
Article in English | MEDLINE | ID: mdl-37448094

ABSTRACT

The authors wish to make the following corrections to the original paper [...].

6.
Sensors (Basel) ; 23(6)2023 Mar 15.
Article in English | MEDLINE | ID: mdl-36991843

ABSTRACT

In high dynamic scenes, fringe projection profilometry (FPP) may encounter fringe saturation, and the phase calculated will also be affected to produce errors. This paper proposes a saturated fringe restoration method to solve this problem, taking the four-step phase shift as an example. Firstly, according to the saturation of the fringe group, the concepts of reliable area, shallow saturated area, and deep saturated area are proposed. Then, the parameter A related to the reflectivity of the object in the reliable area is calculated to interpolate A in the shallow and deep saturated areas. The theoretically shallow and deep saturated areas are not known in actual experiments. However, morphological operations can be used to dilate and erode reliable areas to produce cubic spline interpolation areas (CSI) and biharmonic spline interpolation (BSI) areas, which roughly correspond to shallow and deep saturated areas. After A is restored, it can be used as a known quantity to restore the saturated fringe using the unsaturated fringe in the same position, the remaining unrecoverable part of the fringe can be completed using CSI, and then the same part of the symmetrical fringe can be further restored. To further reduce the influence of nonlinear error, the Hilbert transform is also used in the phase calculation process of the actual experiment. The simulation and experimental results validate that the proposed method can still obtain correct results without adding additional equipment or increasing projection number, which proves the feasibility and robustness of the method.

7.
Cell Mol Biol (Noisy-le-grand) ; 68(3): 365-373, 2022 Mar 31.
Article in English | MEDLINE | ID: mdl-35988187

ABSTRACT

This study aimed to explore the clinical value of Fe3O4-based magnetic lipid nano-contrast agent in breast-conserving surgery for breast cancer using color doppler ultrasound positioning and to analyze the tumor resection effect of breast-conserving surgery. On account of Fe3O4 magnetic nanoparticles prepared by the chemical co-precipitation method, magnetic lipid ultrasonic microbubbles (MLU-MBs) were prepared by mechanical oscillation method after surface modification using polyethylene terephthalate (PET). Characterization and analysis of the prepared MLU-MBs were performed using scanning electron microscopy (SEM), energy spectrometer, transmission electron microscopy (TEM), and Fourier infrared spectroscopy (FIRS). A high-frequency alternating magnetic field was used to detect the heating of MLU-MBs and the color ultrasound machine was applied to observe the enhancement effect of the MLU-MBs on rabbit liver images. 92 patients undergoing breast-conserving surgery for breast cancer were taken as the research objects and were divided into a nano group (MLU-MB as contrast agent) and a control group (conventional contrast agent) according to the differences of intraoperative contrast agents, with 46 cases in each group. Before the surgery, both groups of patients were positioned and marked the tumor boundary under ultrasound. The differences in tumor volume (TV), amount of tissue removed, resection rate, and positive rate (PR) of resection margins were compared between the two groups. The results showed that the Fe3O4 magnetic nanoparticles were particles with an average particle size of about 15nm, and their iron and oxygen percentages were consistent with the content of Fe3O4. The MLU-MBs were spherical particles of about 1120nm, containing phosphorus (P), oxygen(O), and Ferrum (Fe). Under 30A and 220kHz of output current and frequency, the temperature rise of the MLU-MBs suspension with different concentrations was 10 ~ 60°C, and the temperature was constant after heating for 45 minutes. Compared with the rabbit liver parenchyma, the image was greatly enhanced. TV, the amount of tissue removed, the resection rate, and the PR of resection margins in the nano group were obviously lower than those in the control group (P<0.05). It showed that MLU-MBs with good image enhancement effect on account of Fe3O4 magnetic nanoparticles were successfully prepared and it could effectively reduce the PR of normal tissues and the positive margin of two-fold resection during breast-conserving surgery for breast cancer and showed good accuracy and stability.


Subject(s)
Contrast Media , Mastectomy, Segmental , Animals , Contrast Media/chemistry , Lipids , Margins of Excision , Mastectomy, Segmental/methods , Oxygen , Rabbits , Ultrasonography, Doppler, Color
8.
Sensors (Basel) ; 22(23)2022 Dec 01.
Article in English | MEDLINE | ID: mdl-36502089

ABSTRACT

An improved three-frequency heterodyne synthesis phase unwrapping method is proposed to improve the measurement accuracy through phase difference and phase sum operations. This method can reduce the effect of noise and increase the equivalent phase frequency. According to the distribution found in the phase difference calculation process, the Otsu segmentation is introduced to judge the phase threshold. The equivalent frequency obtained from the phase sum is more than those of all projected fringe patterns. In addition, the appropriate period combinations are also studied. The simulations and related experiments demonstrate the feasibility of the proposed method and the ability to improve the accuracy of the measurement results further.

9.
Nano Lett ; 21(11): 4730-4737, 2021 Jun 09.
Article in English | MEDLINE | ID: mdl-34038143

ABSTRACT

A novel n-type nanowire/nanosheet (NW/NS) vertical sandwich gate-all-around field-effect-transistor (nVSAFET) with self-aligned and replaced high-κ metal gates (HKMGs) is presented for the first time, aiming at a 3 nm technology node and beyond. The nVSAFETs were fabricated by an integration flow of Si/SiGe epitaxy, quasi-atomic layer etching (qALE) of SiGe selective to Si, formation of SiGe/Si core/shell NS/NW structure, building of nitride dummy gate, and replacement of the dummy gate. This fabrication method is complementary metal oxide semiconductor (CMOS)-compatible, simple, and reproducible, and NWs with a diameter of 17 nm and NSs with a thickness of 20 nm were obtained. Excellent control of short-channel-effects was presented. The device performance was also investigated and discussed. The proposed integration scheme has great potential for applications in chip manufacturing, especially with vertical channel devices.

10.
Stat Med ; 40(25): 5628-5641, 2021 11 10.
Article in English | MEDLINE | ID: mdl-34263963

ABSTRACT

In biomedical studies, the causal mediation effect might be heterogeneous across individuals in the study population due to each study subject's unique characteristics. While individuals' mediation effects may differ from each other, it is often reasonable and more interpretable to assume that individuals belong to several distinct latent subgroups with similar attributes. In this article, we first show that the subgroup-specific mediation effect can be identified under the group-specific sequential ignorability assumptions. Then, we propose a simple mixture modeling approach to account for the latent subgroup structure where each mixture component corresponds to one latent subgroup in the linear structural equation model framework. Model parameters can be estimated using the standard expectation-maximization (EM) algorithm. Each individual's subgroup membership can be inferred based on the posterior probability. We propose to use the singular Bayesian information criterion to consistently select the number of latent subgroups by recognizing that the Fisher information matrix for mixture models might be singular. We then propose to use nonparametric bootstrap method to compute standard errors and confidence intervals. We conducted simulation studies to evaluate the empirical performance of our proposed method named iMed. Finally, we reanalyzed a DNA methylation data set from the Normative Aging Study and found that the mediation effects of two well-documented DNA methylation CpG sites are heterogeneous across two latent subgroups in the causal pathway from smoking behavior to lung function. We also developed an R package iMed for public use.


Subject(s)
Mediation Analysis , Bayes Theorem , Causality , Computer Simulation , Humans , Probability
11.
Phys Chem Chem Phys ; 23(19): 11466-11471, 2021 May 19.
Article in English | MEDLINE | ID: mdl-33959738

ABSTRACT

Using first-principles calculations, we identify a robust R30° reconstruction of a Si3 trimer bilayer on the Si(111) surface with a La coverage of 2/3 monolayer. Each surface unit cell contains two Si3 trimers and two La atoms, where the upper Si3 trimer is located just above the lower one with a rotation of about 60°, while two La atoms with different heights are distributed between the Si3 trimers and located on the T4 top site of the Si(111) surface, forming a honeycomb-like network structure. We find that the two La atoms have different valence states, La2+ and La3+, respectively. The high structural stability is attributed to the lower La atom saturating all the three dangling bonds of the upper Si3 trimer, while the higher La atom compensates two electrons to the lower Si3 trimer. The electronic band structure and band-decomposed charge density distribution show a semiconducting characteristic with a small surface band gap of 42 meV. Moreover, simulated STM images show a good structural match with the recent experimental observations.

12.
Oncologist ; 25(11): e1640-e1649, 2020 11.
Article in English | MEDLINE | ID: mdl-32533785

ABSTRACT

LESSONS LEARNED: The efficacy of second-line treatment for advanced non-small cell lung carcinoma (NSCLC) without a sensitizing driver gene mutation is still unsatisfactory. The combination of apatinib and chemotherapy improved progression-free survival in the second-line therapy of advanced NSCLC without a sensitizing mutation. This study offers a new treatment strategy for second-line treatment of such patients but requires confirmation in a larger multi-institutional trial. BACKGROUND: This study explored the efficacy and safety of apatinib combined with single-agent chemotherapy versus single-agent chemotherapy in the second-line treatment of advanced non-small-cell lung carcinoma (NSCLC) without driver mutations. METHODS: In this double-arm, open label, exploratory clinical study, we enrolled patients with unresectable locally advanced or advanced NSCLC without driver mutations that had progressed following first-line chemotherapy. The subjects were allocated into an experimental group and a control group by 2:1. The experimental group received apatinib combined with four cycles of docetaxel or pemetrexed until disease progression, intolerable toxicity, or discontinuation at the patient' request. The control group only received four cycles of docetaxel or pemetrexed. The primary endpoints were progression-free survival (PFS), and the secondary endpoints were overall survival (OS), disease control rate (DCR), and safety. RESULTS: Thirty-seven patients were enrolled. The efficacy of 33 patients was evaluated. The median PFS was 5.47 versus 2.97 months, the DCR was 95% versus 73%, and the objective response rate (ORR) was 27% versus 9% in the experimental versus control group. The OS was still under follow-up. The most common adverse effects included hypertension, hand-foot skin reaction (HFSR), and fatigue. CONCLUSION: Apatinib combined with single-agent chemotherapy may be a novel option for second-line treatment of advanced NSCLC.


Subject(s)
Antineoplastic Agents , Antineoplastic Combined Chemotherapy Protocols , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Pyridines , Adult , Aged , Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Female , Humans , Lung Neoplasms/drug therapy , Male , Middle Aged , Pemetrexed/therapeutic use , Pyridines/therapeutic use
13.
Mol Ecol ; 29(23): 4573-4587, 2020 12.
Article in English | MEDLINE | ID: mdl-33006793

ABSTRACT

Genetic stochasticity and bottlenecking in the course of Pleistocene glaciations have been identified as threatening the survival of local endemics. However, the mechanisms by which local endemic species balance the influences of these two events remain poorly understood. Here, we generated a double-digest restriction site-associated DNA sequencing (ddRAD-seq) data set, mined mitochondrial sequences and constructed ecological niche models for the island endemic water strider Metrocoris esakii (Hemiptera: Gerridae). We found that M. esakii comprised three divergent lineages (i.e., north, central and south) isolated by geographical barriers and generally experienced population declines with the constriction of suitable areas during the Last Glacial Maximum (LGM). Further demographic model testing and stairway plots revealed a history of recent gene flow among the neighbouring lineages and rapid recovery at the end of the LGM, indicating that M. esakii at least had the potential for an adaptive response to population fragmentation and bottlenecking. The northern lineage did not show genetic bottlenecking during the LGM, which was probably due to its large effective population size (Ne ) from migration, which improved its adaptive potential. Relative to the ddRAD-seq data set, the demographic results based on mitochondrial sequences were less conclusive, showing weak differentiation and oversimplified demographic trajectories for the three genetic lineages. Overall, this study provides some degree of optimism for the survival of island endemic water striders from a demographic perspective, but further evaluation of their extinction risk under the impacts of human activities is required.


Subject(s)
DNA, Mitochondrial , Genetic Variation , Animals , DNA, Mitochondrial/genetics , Demography , Ecosystem , Humans , Islands , Phylogeny , Phylogeography , Water
14.
Sensors (Basel) ; 20(17)2020 Aug 31.
Article in English | MEDLINE | ID: mdl-32878041

ABSTRACT

The non-contact monitoring of vital signs by radar has great prospects in clinical monitoring. However, the accuracy of separated respiratory and heartbeat signals has not satisfied the clinical limits of agreement. This paper presents a study for automated separation of respiratory and heartbeat signals based on empirical wavelet transform (EWT) for multiple people. The initial boundary of the EWT was set according to the limited prior information of vital signs. Using the initial boundary, empirical wavelets with a tight frame were constructed to adaptively separate the respiratory signal, the heartbeat signal and interference due to unconscious body movement. To verify the validity of the proposed method, the vital signs of three volunteers were simultaneously measured by a stepped-frequency continuous wave ultra-wideband (UWB) radar and contact physiological sensors. Compared with the vital signs from contact sensors, the proposed method can separate the respiratory and heartbeat signals among multiple people and obtain the precise rate that satisfies clinical monitoring requirements using a UWB radar. The detection errors of respiratory and heartbeat rates by the proposed method were within ±0.3 bpm and ±2 bpm, respectively, which are much smaller than those obtained by the bandpass filtering, empirical mode decomposition (EMD) and wavelet transform (WT) methods. The proposed method is unsupervised and does not require reference signals. Moreover, the proposed method can obtain accurate respiratory and heartbeat signal rates even when the persons unconsciously move their bodies.


Subject(s)
Radar , Wavelet Analysis , Algorithms , Heart Rate , Humans , Signal Processing, Computer-Assisted , Vital Signs
15.
Inorg Chem ; 58(1): 428-438, 2019 Jan 07.
Article in English | MEDLINE | ID: mdl-30582691

ABSTRACT

Rietveld refinement is used to investigate the crystal structure of prepared (0.965 - x)(K0.48Na0.52)NbO3- xBiInO3-0.035(Bi0.5Na0.5)ZrO3 (KNN- xBI-BNZ) ceramics. From refined results, the distortion degree of crystal structures in KNN- xBI-BNZ ceramics presents a rising trend with BiInO3 modification, which is in keeping with the results of diffuseness. The spontaneous polarization ( Ps) is also calculated using refined structural parameters. The submicron domains are observed when x = 0.004, which presents good electrical properties ( d33 = 317 pC/N, Tc = 336 °C) simultaneously. Excellent thermal stability of ceramics modified with BiInO3 is observed in a broad temperature range.

16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(2): 320-4, 2015 Feb.
Article in Zh | MEDLINE | ID: mdl-25970885

ABSTRACT

ZnS/CdS composite window layer was prepared by magnetron sputtering method and then applied to CdTe solar cell. The morphology and structure of films were measured. The data of I-V in light and the quantum efficiency of CdTe solar cells with different window layers were also measured. The effect of ZnS films prepared in different conditions on the performance of CdTe solar cells was researched. The effects of both CdS thickness and ZnS/CdS composite layer on the transmission in short wavelength were studied. Particularly, the quantum efficiency of CdTe solar cells with ZnS/CdS window layer was measured. The results show as follows. With the thickness of CdS window layer reducing from 100 to 50 nm, the transmission increase 18.3% averagely in short wavelength and the quantum efficiency of CdTe solar cells increase 27.6% averagely. The grain size of ZnS prepared in 250 degrees C is smaller than prepared at room temperature. The performance of CdTe solar cells with ZnS/CdS window layer is much better if ZnS deposited at 250 degrees C. This indicates grain size has some effect on the electron transportation. When the CdS holds the same thickness, the transmission of ZnS/CdS window layer was improved about 2% in short wavelength compared with CdS window layer. The quantum efficiency of CdTe solar cells with ZnS/CdS window layer was also improved about 2% in short wavelength compared with that based on CdS window layer. These indicate ZnS/CdS composite window layer can increase the photon transmission in short wavelength so that more photons can be absorbed by the absorbent layer of CdTe solar cells.

17.
ScientificWorldJournal ; 2014: 852978, 2014.
Article in English | MEDLINE | ID: mdl-25126605

ABSTRACT

Two common problems are often encountered in analysis dictionary learning (ADL) algorithms. The first one is that the original clean signals for learning the dictionary are assumed to be known, which otherwise need to be estimated from noisy measurements. This, however, renders a computationally slow optimization process and potentially unreliable estimation (if the noise level is high), as represented by the Analysis K-SVD (AK-SVD) algorithm. The other problem is the trivial solution to the dictionary, for example, the null dictionary matrix that may be given by a dictionary learning algorithm, as discussed in the learning overcomplete sparsifying transform (LOST) algorithm. Here we propose a novel optimization model and an iterative algorithm to learn the analysis dictionary, where we directly employ the observed data to compute the approximate analysis sparse representation of the original signals (leading to a fast optimization procedure) and enforce an orthogonality constraint on the optimization criterion to avoid the trivial solutions. Experiments demonstrate the competitive performance of the proposed algorithm as compared with three baselines, namely, the AK-SVD, LOST, and NAAOLA algorithms.


Subject(s)
Algorithms , Artificial Intelligence , Dictionaries as Topic , Models, Theoretical , Computer Simulation
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(4): 888-93, 2014 Apr.
Article in English | MEDLINE | ID: mdl-25007593

ABSTRACT

The effects of device performance of 1.7 MeV electron irradiation on cadmium telluride polycrystalline thin film solar cells with the structure of anti-radiation glass/ITO/ZnO/CdS/CdTe/ZnTe/ZnTe : Cu/Ni have been studied. Light and dark I-V characteristics, dark C-V characteristics, quantum efficiency (QE), admittance spectrum (AS) and other testing methods were used to analyze cells performance such as the open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF) and conversion efficiency (eta). It was explored to find out the effects of irradiation on the current transfer characteristic of solar cells combined with the dark current density (Jo), diode ideal factor (A), quantum efficiency, carrier concentration and the depletion layer width. The decline in short-circuit current was very large and the efficiency of solar cells decreased obviously after irradiation. Reverse saturation current density increased, which indicates that p-n junction characteristics of solar cells were damaged, and diode ideal factor was almost the same, so current transport mechanism of solar cells has not changed. Quantum efficiency curves proved that the damage of solar cells' p-n junction influenced the collection of photo-generated carriers. Irradiation made carrier concentration reduce to 40.6%. The analyses have shown that. A new defect was induced by electron irradiation, whose position is close to 0.58 eV above the valence band in the forbidden band, and capture cross section is 1.78 x 10(-16) cm2. These results indicate that irradiation influences the generation of photo-generated carriers, increases the risk of the carrier recombination and the reverse dark current, and eventually makes the short-circuit current of solar cells decay.

19.
Materials (Basel) ; 17(8)2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38673169

ABSTRACT

Positive temperature coefficient of electrical resistivity (PTCR) materials with low Curie temperature have been paid increasing attention lately. In this study, PTCR materials with a Curie temperature of approximately -15 °C were investigated by La3+ doping Ba0.55Sr0.45TiO3 ceramics. It could be expected to meet the requirements of thermal management systems for low-temperature control. In addition, a trace amount of Bi0.5Na0.5TiO3 (BNT) was employed to improve the resistivity and the PTCR performance. A significant PTCR effect was achieved with a high resistivity jump of nearly four orders of magnitude, a high temperature coefficient of ~28.76%/°C, and a narrow transition temperature span of 22 °C in the (Ba0.55Sr0.45)0.99875La0.00125Ti1.01O3-0.0025Bi0.5Na0.5TiO3 ceramics. The PTCR enhancement mechanism of BNT is discussed.

20.
IEEE J Biomed Health Inform ; 28(4): 2175-2186, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38109246

ABSTRACT

Biomedical image segmentation of organs, tissues and lesions has gained increasing attention in clinical treatment planning and navigation, which involves the exploration of two-dimensional (2D) and three-dimensional (3D) contexts in the biomedical image. Compared to 2D methods, 3D methods pay more attention to inter-slice correlations, which offer additional spatial information for image segmentation. An organ or tumor has a 3D structure that can be observed from three directions. Previous studies focus only on the vertical axis, limiting the understanding of the relationship between a tumor and its surrounding tissues. Important information can also be obtained from sagittal and coronal axes. Therefore, spatial information of organs and tumors can be obtained from three directions, i.e. the sagittal, coronal and vertical axes, to understand better the invasion depth of tumor and its relationship with the surrounding tissues. Moreover, the edges of organs and tumors in biomedical image may be blurred. To address these problems, we propose a three-direction fusion volumetric segmentation (TFVS) model for segmenting 3D biomedical images from three perspectives in sagittal, coronal and transverse planes, respectively. We use the dataset of the liver task provided by the Medical Segmentation Decathlon challenge to train our model. The TFVS method demonstrates a competitive performance on the 3D-IRCADB dataset. In addition, the t-test and Wilcoxon signed-rank test are also performed to show the statistical significance of the improvement by the proposed method as compared with the baseline methods. The proposed method is expected to be beneficial in guiding and facilitating clinical diagnosis and treatment.


Subject(s)
Liver , Neoplasms , Humans , Liver/diagnostic imaging , Abdomen , Imaging, Three-Dimensional/methods , Neoplasms/diagnostic imaging , Tomography, X-Ray Computed/methods , Image Processing, Computer-Assisted/methods
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