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Exosomes are small vesicles containing proteins, nucleic acids, and biological lipids, which are responsible for intercellular communication. Studies have shown that exosomes can be utilized as effective drug delivery vehicles to accurately deliver therapeutic substances to target tissues, enhancing therapeutic effects and reducing side effects. Mesenchymal stem cells (MSCs) are a class of stem cells widely used for tissue engineering, regenerative medicine, and immunotherapy. Exosomes derived from MSCs have special immunomodulatory functions, low immunogenicity, the ability to penetrate tumor tissues, and high yield, which are expected to be engineered into efficient drug delivery systems. Despite the promising promise of MSC-derived exosomes, exploring their optimal preparation methods, drug-loading modalities, and therapeutic potential remains challenging. Therefore, this article reviews the related characteristics, preparation methods, application, and potential risks of MSC-derived exosomes as drug delivery systems in order to find potential therapeutic breakthroughs. [ABSTRACT FROM AUTHOR]

Two-stage remote sensing image captioning (RSIC) methods have achieved promising results by incorporating additional pre-trained remote sensing tasks to extract supplementary information and improve caption quality. However, these methods face limitations in semantic comprehension, as pre-trained detectors/classifiers are constrained by predefined labels, leading to an oversight of the intricate and diverse details present in remote sensing images (RSIs). Additionally, the handling of auxiliary remote sensing tasks separately can introduce challenges in ensuring seamless integration and alignment with the captioning process. To address these problems, we propose a novel cross-modal retrieval and semantic refinement (CRSR) RSIC method. Specifically, we employ a cross-modal retrieval model to retrieve relevant sentences of each image. The words in these retrieved sentences are then considered as primary semantic information, providing valuable supplementary information for the captioning process. To further enhance the quality of the captions, we introduce a semantic refinement module that refines the primary semantic information, which helps to filter out misleading information and emphasize visually salient semantic information. A Transformer Mapper network is introduced to expand the representation of image features beyond the retrieved supplementary information with learnable queries. Both the refined semantic tokens and visual features are integrated and fed into a cross-modal decoder for caption generation. Through extensive experiments, we demonstrate the superiority of our CRSR method over existing state-of-the-art approaches on the RSICD, the UCM-Captions, and the Sydney-Captions datasets [ABSTRACT FROM AUTHOR]

Purpose: Direct immunofluorescence (DIF) on frozen sections (DIF-F) plays a key role in the identification and differential diagnosis of bullous dermatoses, which are a group of critical autoimmune diseases that include pemphigus, bullous pemphigoid (BP), and epidermolysis bullosa acquisita (EBA). However, this technique requires specialized laboratory equipment conditions, sample acquisition and sample preservation. In this study, the application value of DIF on paraffin-embedded tissue sections (DIF-P) detecting IgG using heat-induced antigen retrieval (HIAR) in the diagnosis of bullous dermatosis was explored. Patients and Methods: Samples from 12 patients with pemphigus vulgaris (PV), 10 patients with pemphigus foliaceus (PF), 17 patients with BP, and 4 patients with EBA were retrospectively studied for DIF-P IgG detection. Formalin-fixed, paraffin-embedded tissue (FFPE) was used, and the antigen retrieval method used in the experiment was HIAR. All patients were diagnosed with the autoimmune bullous disease (AIBD) based on clinical presentation, histopathology, DIF-F, and enzyme-linked immunosorbent assay (ELISA). Results: Intercellular staining for IgG in the epidermis was successful in paraffin-embedded tissue sections in 11 of 12 PV samples and in all 10 PF samples. IgG at the basement membrane zone (BMZ) was not detected by immunofluorescent staining in 17 BP samples and 4 EBA samples. Conclusion: The detection of IgG by DIF-P using HIAR can be used for the diagnosis of pemphigus as an alternative method to DIF-F. [ABSTRACT FROM AUTHOR]

Welding via bond exchange reactions has provided advances in obtaining high-quality joining performance. However, the reported welding method requires a relatively high press force, and challenges are still encountered in welding hard vitrimer. In this work, a facile surface depolymerization strategy was introduced to weld high-performance epoxy vitrimer. The vitrimers were firstly dissolved into ethylene glycol for depolymerization based on the solvent-assisted bond exchange reactions. Then, the depolymerized vitrimers were welded under heat and press force. The effect of the depolymerizing time, welding pressure, welding temperature and welding time on the welding strength were further investigated. It was found that there were optimal values for the depolymerizing time, welding pressure, and welding temperature, respectively, for the welding strength, while the welding strength increased with increasing welding time. Through facile surface degradation, the welding pressure was highly reduced, while the welding strength was increased. With surface depolymerization, the welding strength was 1.55-times higher, but the magnitude of press force was 1/1000-times than that with no surface depolymerization. It is elucidative that surface depolymerization can be used to weld hard vitrimer composites alongside reducing the press force effectively. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is one of the important macronutrients in plants, and N deficiency induces leaf senescence. However, the molecular mechanism underlying how N deficiency affects leaf senescence is unclear. Here, we report an apple NAC TF, MdNAC4, that participates in N deficiency-induced leaf senescence. The senescence phenotype of apple leaves overexpressing MdNAC4 was enhanced after N deficiency. Consistently, the chlorophyll content of transgenic leaves was significantly lower than that in the WT control leaves, the expression of chlorophyll catabolism-related genes (MdNYC1 , MdPAO , and MdSGR1) was significantly higher than that in the WT controls, and the expression of chlorophyll synthesis-related genes (MdHEMA , MdCHLI , and MdCHLM) was significantly lower than that in the WT control leaves. Furthermore, MdNAC4 was found to directly activate the transcription of the chlorophyll catabolism-related genes MdNYC1 and MdPAO. Additionally, MdNAC4 was proven to interact with MdAPRR2 proteins both in vitro and in vivo , and overexpression of MdAPRR2 seemed to delay N deficiency-induced leaf senescence. Correspondingly, the chlorophyll loss of MdAPRR2-overexpressing (MdAPRR2-OE) lines was significantly lower than in WT control plants. Although downregulated, the expression of the chlorophyll synthesis-related genes MdHEMA , MdCHLI , and MdCHLM in the transgenic plants was more than twice that in the WT control plants. Taken together, our results enrich the regulatory network of leaf senescence induced by N deficiency through the interaction between MdNAC4 and MdAPRR2. [ABSTRACT FROM AUTHOR]

Vehicle detection in remote sensing imagery is a challenging task because of its inherent attributes, e.g., dense parking, small sizes, various angles, etc. Prevalent vehicle detectors adopt an oriented/rotated bounding box as a basic representation, which needs to apply a distance regression of height, width, and angles of objects. These distance-regression-based detectors suffer from two challenges: (1) the periodicity of the angle causes a discontinuity of regression values, and (2) small regression deviations may also cause objects to be missed. To this end, in this paper, we propose a new vehicle modeling strategy, i.e., regarding each vehicle-rotated bounding box as a saliency area. Based on the new representation, we propose SR-Net (saliency region representation network), which transforms the vehicle detection task into a saliency object detection task. The proposed SR-Net, running in a distance (e.g., height, width, and angle)-regression-free way, can generate more accurate detection results. Experiments show that SR-Net outperforms prevalent detectors on multiple benchmark datasets. Specifically, our model yields 52.30%, 62.44%, 68.25%, and 55.81% in terms of AP on DOTA, UCAS-AOD, DLR 3 K Munich, and VEDAI, respectively. [ABSTRACT FROM AUTHOR]

In the domain of data parallel computation, most works focus on data flow optimization inside the PE array and favorable memory hierarchy to pursue the maximum parallelism and efficiency, while the importance of data contents has been overlooked for a long time. As we observe, for structured data, insights on the contents (i.e., their values and locations within a structured form) can greatly benefit the computation performance, as fine-grained data manipulation can be performed. In this paper, we claim that by providing a flexible and adaptive data path, an efficient architecture with capability of fine-grained data manipulation can be built. Specifically, we design SOM, a portable and highly-adaptive data transmission network, with the capability of operand sorting, non-blocking self-route ordering and multicasting. Based on SOM, we propose the processing-in-transmission architecture (PITA), which extends the traditional SIMD architecture to perform some fundamental data processing during its transmission, by embedding multiple levels of SOM networks on the data path. We evaluate the performance of PITA in two irregular computation problems. We first map the matrix inversion task onto PITA and show considerable performance gain can be achieved, resulting in 3×-20× speedup against Intel MKL, and 20×-40× against cuBLAS. Then we evaluate our PITA on sparse CNNs. The results indicate that PITA can greatly improve computation efficiency and reduce memory bandwidth pressure. We achieved 2×-9× speedup against several state-of-art accelerators on sparse CNN, where nearly 100 percent PE efficiency is maintained under high sparsity. We believe the concept of PIT is a promising computing paradigm that can enlarge the capability of traditional parallel architecture. [ABSTRACT FROM AUTHOR]

Objective: To demonstrate similar image quality with deep learning image reconstruction (DLIR) in reduced contrast medium (CM) and radiation dose (double‐low‐dose) head CT angiography (CTA), in comparison with standard‐dose and adaptive statistical iterative reconstruction‐Veo (ASIR‐V). Methods: A prospective study was performed in 63 patients who under head CTA using 256‐slice CT. Patients were randomized into either the standard‐dose group (n = 38) with 40 ml of Iopromide (370 mgI ml−1 at 4.5 ml s−1); or a double‐low‐dose group (n = 25) with CM of 25 ml at 3.0 ml s−1. For image reconstruction, the double‐low‐dose group used DLIR‐M and DLIR‐H strength, and the standard‐dose group used ASIR‐V with 50% strength. The CT value and standard deviation, signal‐to‐noise ratio and contrast‐to‐noise ratio of posterior fossa, neck muscles, carotid, vertebral and middle cerebral arteries were measured. The image noise, vessel edge and structure blurring and overall image quality were assessed by using a 5‐grade method. The double‐low‐dose group reduced CM dose by 37.5% and CT dose index by 41% compared with the standard‐dose group. DLIR further reduced the standard deviation value of the middle cerebral artery and posterior fossa and provided better overall subjective image quality (p < 0.05). Conclusion: DLIR significantly reduces image noise and provides higher overall image quality in the double‐low‐dose CTA. Advances in knowledge: It is feasible to reduce CM dose by 37.5% and volume CT dose index by 41% with the combination of 80 kVp and DLIR in head CTA. Compared with ASIR‐V, DLIR further reduces image noise and achieves better image quality with reduced contrast and radiation dose. [ABSTRACT FROM AUTHOR]

A multilevel per cell (MLC) technique significantly improves the storage density, but also poses serious data integrity challenge for NAND flash memory. This consequently makes the low-density parity-check (LDPC) code and the soft-decision memory sensing become indispensable in the next-generation flash-based solid-state storage devices. However, the use of LDPC codes inevitably increases memory read latency and, hence, degrades speed performance. Motivated by the observation of intracell unbalanced bit error probability and data dependence in the MLC NAND flash memory, this paper proposes two techniques, i.e., intracell data placement interleaving and intracell data dependence aware LDPC decoding, to efficiently improve the LDPC decoding throughput and energy efficiency for the MLC NAND flash-based storage in a mobile device. Experimental results show that, by exploiting the intracell bit-error characteristics, the proposed techniques together can improve the LDPC decoding throughput by up to 84.6% and reduce the energy consumption by up to 33.2% while only incurring less than 0.2% silicon area overhead. [ABSTRACT FROM PUBLISHER]

Highlights: [•] High aromatics and low asphaltenes could improve dispersion of SBS. [•] Particle size distribution curve S/B ratio at 30/70 was narrower than others. [•] As SBS contents increasing the particle size distribution curve became wide. [•] With the range of SBS distribution becoming narrow the viscosity was increased. [ABSTRACT FROM AUTHOR]

Epoxy-anhydride resins are widely used in engineering fields due to their excellent performance. However, the insolubility and infusibility make the recycling of epoxy resins challenging. The development of degradable epoxy resins with stable covalent networks provides an efficient solution to the recycling of thermosets. In this paper, 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) is incorporated into the epoxy-glutaric anhydride (GA) system to prepare high-performance epoxy resins that can be recycled below 200 °C at ordinary pressure via ethylene glycol (EG) participated transesterification. The tertiary amine groups in DMP-30 can catalyze the curing reaction of epoxy and anhydride, as well as the transesterification between ester bonds and alcoholic hydroxyl groups. Compared with early recyclable anhydride-cured epoxy resins, the preparation and recycling of diglycidyl ether of bisphenol A (DGEBA)/GA/DMP-30 systems do not need any special catalysts such as TBD, Zn(Ac)2, etc., which are usually expensive, toxic, and have poor compatibility with other compounds. The resulting resins have glass transition temperatures and strengths similar to those of conventional epoxy resins. The influences of GA content, DMP-30 content, and temperature on the dissolution rate were studied. The decomposed epoxy oligomer (DEO) is further used as a reaction ingredient to prepare new resins. It is found that the DEO can improve the toughness of epoxy resins significantly. This work provides a simple method to prepare readily recyclable epoxy resins, which is of low-cost and easy to implement. [ABSTRACT FROM AUTHOR]

This research analyzed key technologies, including object tracking and image matching, for realizing a television guidance system and proposed multiple kernels matching for precise television guidance. A semiphysical simulation system was designed to test the effectiveness of the proposed method. The experimental results showed that this method performed well in a television guidance system and did better than a template matching method. [ABSTRACT FROM AUTHOR]

Understanding the heat transfer characteristics of supercritical kerosene is significant for the corresponding engineering design, and the special properties of supercritical fluids make the heat transfer more complicated. In this article, the heat transfer characteristics of kerosene under the condition of supercritical pressure, high heat flux and high velocity were investigated and analyzed. The experimental results show that with the increase of flow velocity and inlet temperature at supercritical pressure, the heat transfer coefficient of kerosene increases and the pressure has little effect on the heat transfer coefficient. Experiment shows that when the inlet temperature is high, coking phenomenon may occur to affect heat transfer. Considering the particularity of the properties of supercritical kerosene and its violent changes of physical parameters in the flow space, dynamic viscosity and thermal conductivity were introduced to modify the traditional kerosene heat transfer correlation. Simultaneously taking the changes of the physical properties of kerosene in time dimension into consideration, the temperature probability density function (PDF) was introduced to obtain the time average physical property from the perspective of probability and statistics. The results show that when the inner wall temperature exceeds 400 °C, the kerosene heat transfer correlation with radial correction factors can reduce the predicted average error to 13%. With the proper selections of the standard deviation, the PDF model can reduce prediction error of 6% to 11% at high wall temperature. The results of this article provide reliable support for the reasonable design of the relevant equipment. [ABSTRACT FROM AUTHOR]

A facile strategy has been developed for the preparation of novel silver/poly(styrene-N-isopropylacrylamide-methacrylic acid) (Ag/PSNM) nanocomposite spheres with high catalytic activity and good storage stability. Silver (Ag) nanoparticles are successfully deposited on poly(styrene-N-isopropylacrylamide-methacrylic acid) (PSNM) spheres surfaces via in situ reduction and simultaneously protected by polyvinylpyrrolidone (PVP). The prepared Ag/PSNM nanocomposite spheres show good temperature/pH responsive property and improved thermal property. Moreover, they also exhibit high catalytic activity and good recyclability for the catalytic reduction of methylene blue (MB) to leuco methylene blue (LMB). The result of clock reaction indicate that the redox reaction generates a colorless (LMB) solution which easily reverts back to blue (MB) in air. The catalytic activity increase with the increasing of temperature and the reaction rate constant (k) follows the typical Arrhenius-type dependence on temperature. In addition, the prepared Ag/PSNM nanocomposite spheres show good storage stability and the catalytic activity remains almost unchanged after storage for 90 days at room temperature. Therefore, the prepared Ag/PSNM nanocomposite spheres can have a highly potential use in the catalytic degradation of organic dyes in wastewater treatment applications. [ABSTRACT FROM AUTHOR]

A series of polyimide (PI) films, polyimide/pure silica zeolite nanoparticles (PSZN) blend films and polyimide/amine-functionalized pure silica zeolite nanoparticles (APSZN) composite films were successfully prepared by random copolycondensation. Thereinto, PSZN were synthesized by hydrothermal method. The polyimides were derived from 4,4′-diaminodiphenyl ether (ODA), and three adjustable molar ratios (3:1, 1:1, 1:3) of 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl] propane dianhydride (BPADA) and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA). The effects of PSZN, APSZN and different chain structure on PI films were specifically evaluated in terms of morphology, thermal, mechanical, dielectric and UV-shielding properties, etc. Comparison was given among pure PI flims, PI/PSZN blend films and PI/APSZN composite flims. The results showed that the thermal and mechanical properties of PI films were drastically impaired after adding PSZN. On the contrary, the strength, toughness and thermal stability were improved after adding APSZN. Moreover, the dielectric constants of the PI/APSZN composite flims were lowered but UV-shielding properties were enhanced. Interestingly, we found that the greatest effects were obtained through introducing APSZN in PI derived by the 1:1 ratio of BPADA:6FDA. The corresponding PI/APSZN composite flim exhibited the most reinforced and toughened properties, the largest decrement of dielectric constant and the best UV-shielding efficiency, which made the composite flim be used as ultraviolet shielding material in outer space filled with high temperature and intensive ultraviolet light. Meanwhile, this work also provided a facile way to synthesize composite materials with adjustable performance. [ABSTRACT FROM AUTHOR]

Preparation of high-performance semiconductor photocatalysts is often considered to be the challenge and focus in dealing with water contaminations, and attracts numerous concerns and research interests nowadays. In this work, high-performance Z-scheme AgI/(Na,F) doped g-C 3 N 4 composites were synthesized by facile calcination and in-situ deposition methods and employed for ultrahigh-performance degradation of broad-spectrum antibiotics contaminants. The prepared (Na,F) doped g-C 3 N 4 showed narrower bandgaps, enhanced solar-light absorption, and highly improved visible-light photocatalytic performance. Besides, the strong combined interfaces between AgI nanoparticles and (Na,F) doped g-C 3 N 4 was contributing to visible-light harvesting and highly boosted charge separation of the samples, among which AgI/(Na,F)–CN-40% composite presented the best visible-light photocatalytic performance. The photocatalytic reaction rate constant of the AgI/(Na,F)–CN-40% composite was as high as approximately 0.2007 min−1, which was 65.80 times of pristine g-C 3 N 4 and 3.60 times of AgI, mainly because of the construction of direct Z-scheme charge transfer pathways between AgI and (Na,F) doped g-C 3 N 4. Finally, the radical scavenger experiments, possible degradation pathways, and photocatalytic mechanism were also proposed. [Display omitted] • Direct Z-scheme AgI/(Na,F)–CN composites were synthesized; • The sample showed ultrahigh-performance photodegradation of antibiotic contaminants; • The sample showed high photocatalytic stability and chemical stability; • Direct Z-scheme charge transfer mechanism were proposed. [ABSTRACT FROM AUTHOR]

Background: Coronary computed tomography angiography (CTA) has been increasingly used to identify the degree of coronary artery stenosis and plaque lesions in vessels. This study evaluated the feasibility of using high-definition (HD) scanning with high-level deep learning image reconstruction (DLIR-H) to improve the image quality and spatial resolution when imaging calcified plaques and stents in coronary CTA as compared to the standard definition (SD) reconstruction mode with adaptive statistical iterative reconstruction-V (ASIR-V)., Methods: A total of 34 patients (age 63.3±10.9 years; 55.88% female) with calcified plaques and/or stents who underwent coronary CTA in HD-mode were included in this study. Images were reconstructed with SD-ASIR-V, HD-ASIR-V, and HD-DLIR-H. Subjective image quality with image noise and clarity of vessels, calcifications, and stented lumens was evaluated by 2 radiologists using a 5-point scale. The kappa (κ) test was used to analyze the interobserver agreement. Objective image quality with image noise, signal-to-noise-ratio (SNR), and contrast-to-noise-ratio (CNR) was measured and compared. Image spatial resolution and beam-hardening artifacts (BHAs) were also evaluated using the calcification diameter and CT numbers in 3 points along the stented lumen (inside, at the proximal and distal ends just outside stent)., Results: There were 45 calcified plaques and 4 coronary stents. HD-DLIR-H images had the highest overall image quality score (4.50±0.63) with the lowest image noise (22.59±3.59 HU) and the highest SNR (18.30±4.88) and CNR (26.56±6.33), followed by SD-ASIR-V50% image quality score (4.06±2.49), image noise (35.02±8.09 HU), SNR (12.77±1.59), CNR(15.67±1.92) and HD-ASIR-V50% image quality score (3.90±0.64), image noise (57.7±12.03 HU), SNR (8.16±1.86), CNR (10.01±2.39). HD-DLIR-H images also had the smallest calcification diameter measurement (2.36±1.58 mm), followed by HD-ASIR-V50% (3.46±2.07 mm) and SD-ASIR-V50% (4.06±2.49 mm). HD-DLIR-H images had the closest CT value measurements for the 3 points along the stented lumen, indicating much less BHA. Interobserver agreement on the image quality assessment was good to excellent (HD-DLIR-H: κ value =0.783; HD-ASIR-V50%: κ value =0.789; SD-ASIR-V50%: κ value =0.671)., Conclusions: Coronary CTA with HD scan mode and DLIR-H significantly improves the spatial resolution for displaying calcifications and in-stent lumens while simultaneously reducing image noise., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-22-186/coif). The authors have no conflicts of interest to declare., (2023 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

In an ECG auto-analysis system, correct QRS detection is most important. For this detection there are several methods, such as derivative-based algorithms, filter-bank methods and wavelet based methods and neural network approaches, but there is no single method that is extensively used. These methods are compared and analyzed in this paper.