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Objective: This study aims to investigate the current status and trends of pressure ulcer care studies over the past two decades using bibliometric and visual analysis, with the objective of providing guidelines for the development of relevant clinical practices or further research. Methods: We conducted a search on the Web of Science Core Collection database using the subject terms “pressure ulcers” or “pressure injuries” for the period from January 2002 to December 2021. Bibliometric tools such as CiteSpace (version 5.8.R3), VOS viewer (version 1.6.17) and the R software 4.0.3 were used to visualize and analyze annual publications, country, institution, author, keyword and cited literature. Results: We identified 5102 publications related to pressure ulcers during the 20-year period, including 4034 articles published in 1557 journals. The number of annual publications on the relevant topics has been increasing annually at an annual growth rate of 4.89 %. The keyword cluster analysis of these studies can be divided into four areas: epidemiology, risk assessment, caring intervention and prognostic analysis. Keyword temporal analysis revealed that the “Braden score” was the most commonly used keyword over a long-term span. The dissemination of knowledge and student training on pressure ulcers have become hot topics of research in recent years. Additionally, pressure ulcer care in COVID-19 patients has emerged as another research hotspot due to the pandemic. Conclusion: Bibliometric analyses have shown that there has been a steady increase in research on pressure ulcer care, with studies related to pressure ulcer risk scores accounting for a large portion of this research. In recent years, education on pressure ulcer-related knowledge and pressure ulcer care in COVID-19 patients have emerged as research hotspots. Future research on pressure ulcer care in the elderly may be a research hotspot as the aging population progresses.

ObjectiveAiming at the problem of the narrow dynamic range of current optical fiber displacement sensors, a balloon-like long-period fiber grating (LPFG) displacement sensor with a simple structure and easy preparation method is designed. MethodsBased on simulation and optimization by RSOFT software, the measurement range is determined by the balloon-like optical fiber under different curvatures. A multimode fiber balloon-like LPFG (MMF-BLPFG) formed by periodically embedding multimode fiber (MMF) into single-mode fiber (SMF) provides a reference peak for measuring the displacement. Using a precise continuous cutting device as the experimental basis, test samples consistent with the simulation results are prepared for testing. ResultsThe maximum displacement measurement range of 36 mm is achieved by measuring the drift of two resonance peaks. ConclusionsThe proposed sensor has good application potential in large-scale measurement scenarios such as the stability measurement and continuous monitoring of the underwater drainage space piping systems of ships.

AbstractSkin infection is a major health issue that usually is caused by the continuous proliferation of bacteria in wounds. With the abuse of antibiotics worldwide, the battle against skin infection is becoming more and more difficult. Therefore, the development of new ways with different antibacterial mechanisms to current antibiotics is urgently needed. Inspired by the powerful inhibition of ferroptosis used in cancer therapy, here in our study, ferric-loaded lipid nanoparticles (Fe-LNPs) with unform size (∼130 nm) and surface charge (∼12 mV) were constructed and found to effectively inhibit the growth of both Gram positive (Staphylococcus aureus, S. aureus) and negative (Escherichia coli, E. coli) strains, possibly due to induction of ferroptosis-like cell death mechanisms. Most importantly, Fe-LNPs can also effectively inhibit the proliferation of S. aureus in a skin infection model and promote the healing of wounds. The Fe-LNPs can be applied as a powerful antibacterial formulation for future application in clinic.

Although advanced deep learning techniques have significantly improved SAR ship detection, accurately detecting small ships remains challenging due to their limited size and the few appearance and geometric clues available. In order to solve this problem, we propose several small object detection strategies. The backbone network uses space-to-depth convolution to replace stride and pooling. It reduces information loss during down-sampling. The neck integrates multiple layers of features globally and injects global and local information into different levels. It avoids the inherent information loss of traditional feature pyramid networks and strengthens the information fusion ability without significantly increasing latency. The proposed intersection-of-union considers the center distance and scale of small ships specifically. It reduces the sensitivity of intersection-of-union to positional deviations of small ships, which is helpful for training toward small ships. During training, the smaller the localization loss of small ships, the greater their localization loss gains are. By this, the supervision of small ships is strengthened in the loss function, which can make the losses more biased toward small ships. A series of experiments are conducted on two commonly used datasets, SSDD and SAR-Ship-Dataset. The experimental results show that the proposed method can detect small ships successfully and thus improve the overall performance of detectors.

The tumor microenvironment is closely linked to the initiation, promotion, and progression of solid tumors. Among its constitutions, immunologic cells emerge as critical players, facilitating immune evasion and tumor progression. Apart from their indirect impact on anti-tumor immunity, immunocytes directly influence neoplastic cells, either bolstering or impeding tumor advancement. However, current therapeutic modalities aimed at alleviating immunosuppression from regulatory cells on effector immune cell populations may not consistently yield satisfactory results in various solid tumors, such as breast carcinoma, colorectal cancer, etc. Therefore, this review outlines and summarizes the direct, dualistic effects of immunocytes such as T cells, innate lymphoid cells, B cells, eosinophils, and tumor-associated macrophages on tumor cells within the tumor microenvironment. The review also delves into the underlying mechanisms involved and presents the outcomes of clinical trials based on these direct effects, aiming to propose innovative and efficacious therapeutic strategies for addressing solid tumors.

Globalization and informatization have exerted far-reaching impacts on the spatial connection and development of urban systems. This study, concerning the network of an urban system based on the space of flows, supplements the insufficiency on the micro-level in macro-urban network research. Taking Nanjing as an example, this study explores the characteristics of the network of the urban system from the perspective of people flow, refining the granularity of the analysis to the township- and street-level spatial units using mobile phone data. The findings are as follows: (1) There is a multicenter layered network pattern, with the main urban area being the core of the network, while Dongshan Street and Moling Street, as secondary centers, form a joint development pattern with the main urban area. (2) The spatial differentiation is significant. The spatial heterogeneity of “centralization in the central region, delayering in the north, and hierarchization in the south” is obvious. The net people inflow nodes are mainly concentrated in the main urban area and its surroundings, while the net outflow nodes are mostly located on the edge of the city. Moreover, the nodes to the south of Yangtze River are advantageous in urban resource control. (3) The phenomenon of “double shadow circle” appears in the ring of the main city and the ring of the municipal area. Moreover, the northern district experiences a serious outflow of population. (4) The effect of policy intervention is beginning to show. Improved levels of development of street and township units such as Jiangbei New District show the positive influence of national strategy on regional development.

Aeromagnetic surveys are widely used in geological exploration, mineral resource assessment, environmental monitoring, military reconnaissance, and other areas. It is necessary to perform magnetic compensation for interference in these fields. In recent years, large unmanned aerial vehicles (UAVs) have been more suitable for magnetic detection missions because of the greater loads they can carry. This article proposes some methods for the magnetic compensation of large multiload UAVs. Because of the interference of the large platform and instrument noise, the standard deviations (stds) of the compensation data used in this paper are larger. At the beginning of this article, using the traditional T-L model, we avoid the shortcomings of the anti-magnetic interference ability of triaxial magnetic gate magnetometers. The direction cosine information is obtained by using an inertial navigation system, the global positioning system, and a triaxial magnetic gate magnetometer. Then, we increase the amplitude of the maneuvers in the compensation process; this reduces the multicollinearity problems in the compensation matrix to a certain extent, but it also results in greater magnetic field interference. Lastly, we employ the method of Lasso regularization Newton iteration (LRNM). Compared to the traditional methods of least squares (LS) and singular value decomposition (SVD), LRNM provides improvements of 34% and 27%, respectively. In summary, this series of schemes can be used to perform effective compensation for large multi-load UAVs and improve the actual use of large UAVs, making them more accurate in the measurement of aeromagnetic survey data.

The objective of this study was to analyze the response of runoff in the area of runoff yield of the upstream Shiyang River basin to climate change and to promote sustainable development of regional water resources and ecological environment. As the biggest tributary of the Shiyang River, Xiying River is the only hydrological station (Jiutiaoling) that has provincial natural river and can achieve long time series monitoring data in the basin. The data obtained from this station is representative of natural conditions because it has little human activites. This study built a regression model through identifying the characteristics of runoff and climate change by using Mann-Kendall nonparametric statistical test, cumulative anomaly, and correlation analysis. The results show that the average annual runoff is 320.6 million m3/a with the coefficient of variation of 0.18 and shows slightly decrease during 1956–2020. It has a significant positive correlation the average annual precipitation (P

Abstract Siglec‐15, a novel immune suppressor, is upregulated in many human cancers. The aim of this study was to explore the expression of Siglec‐15 in colorectal cancer (CRC), and investigate whether Siglec‐15 could be a potential target for cancer immunotherapy in patients with CRC. We performed immunohistochemical analyses of Siglec‐15 on a cohort of 805 patients with CRC and made comparisons between clinicopathological characteristics, PD‐L1 expression, CD3, CD8, CD45RO tumor‐infiltrating lymphocytes (TILs), and prognosis. We found that Siglec‐15 expression was commonly detected in tumor cells (48.3%) and tumor‐associated stromal cells (33.4%), and was more frequently observed than PD‐L1 expression in tumor cells. In contrast, Siglec‐15 expression was weakly and scarcely found in normal mucosa (13%). Siglec‐15 overexpression in tumor cells was associated with advanced TNM stage (p = 0.020). Co‐expression of Siglec‐15 and PD‐L1 in tumor cells was found in 14.4% of patients, and Siglec‐15 expression was detected in almost half of PD‐L1 negative cases. Elevated Siglec‐15 expression in tumor and stromal cells was associated with sparser CD45RO and CD8 TILs (p = 0.035 and p = 0.004, respectively). The expression of Siglec‐15 did not have prognostic significance. In summary, compared to PD‐L1, Siglec‐15 protein expression is more prevalent in CRC and is associated with advanced disease stage and fewer TILs. These findings support Siglec‐15 as a potential cancer immunotherapy target, in addition to PD‐1/PD‐L1 inhibitors, in patients with CRC.

The Doppler information in complement to the intensity of radar backscatter has been verified useful for ocean synthetic aperture radar (SAR) applications. An accurate estimate of the ocean surface motions requires an accurate estimate of the Doppler centroid. When we process the real SAR data, we find that different methods yield different mean values of the estimates. After a careful analysis, we find that it is caused by the underestimation of the centroids for conventional methods. The estimate bias depends on the Doppler centroid itself. To overcome this problem, we carefully study the conventional methods and the Cramér–Rao bound of the estimation. Based on the maximum-likelihood principle, a novel method is proposed. By adaptively adjusting the center and the bandwidth of the weighting function after a coarse estimation of the spectrum, the symmetry of the spectrum is maintained. The estimate bias of conventional methods is eliminated. It is a fully optimal method meeting the Cramér–Rao bound no matter whether the true Doppler centroid is high or low. Both the simulated and the real SAR data validate our novel method. In the simulation, an estimate error of tens of Hz could be avoided when the true Doppler center is hundreds of hertz. In real SAR estimation, an accuracy of 3–6 Hz can be improved. The result of the estimation is consistent with the simulation and theoretical analysis, validating the efficiency of our improved method.

Recently, deep learning has greatly promoted the development of synthetic aperture radar (SAR) ship detection. But the detectors are usually heavy and computation intensive, which hinder the usage on the edge. In order to solve this problem, a lot of lightweight networks and acceleration ideas are proposed. In this survey, we review the papers that are about real-time SAR ship detection. We first introduce the model compression and acceleration methods. They are pruning, quantization, knowledge distillation, low-rank factorization, lightweight networks, and model deployment. They are the source of innovation in real-time SAR ship detection. Then, we summarize the real-time object detection methods. They are two-stage, single-stage, anchor free, trained from scratch, model compression, and acceleration. Researchers in SAR ship detection usually learn from these ideas. We then spend a lot of content on the review of the 70 real-time SAR ship detection papers. The years, datasets, journals, deep-learning frameworks, and hardwares are introduced first. After that, 10 public datasets and the evaluation metrics are shown. Then, we survey the 70 papers according to anchor free, trained from scratch, YOLO series, constant false alarm rate+convolutional neural network, lightweight backbone, pruning, quantization, knowledge distillation, and hardware deployment. The experimental results show that the algorithms have been greatly developed in speed and accuracy. In the end, we pointed out the problems of 70 papers and the directions to be studied in the future. This article can enable researchers to quickly understand the research status in this field.

Abstract Nanozymes, featuring intrinsic biocatalytic effects and broad‐spectrum antimicrobial properties, are emerging as a novel antibiotic class. However, prevailing bactericidal nanozymes face a challenging dilemma between biofilm penetration and bacterial capture capacity, significantly impeding their antibacterial efficacy. Here, this work introduces a photomodulable bactericidal nanozyme (ICG@hMnOx), composed of a hollow virus‐spiky MnOx nanozyme integrated with indocyanine green, for dually enhanced biofilm penetration and bacterial capture for photothermal‐boosted catalytic therapy of bacterial infections. ICG@hMnOx demonstrates an exceptional capability to deeply penetrate biofilms, owing to its pronounced photothermal effect that disrupts the compact structure of biofilms. Simultaneously, the virus‐spiky surface significantly enhances the bacterial capture capacity of ICG@hMnOx. This surface acts as a membrane‐anchored generator of reactive oxygen species and a glutathione scavenger, facilitating localized photothermal‐boosted catalytic bacterial disinfection. Effective treatment of methicillin‐resistant Staphylococcus aureus‐associated biofilm infections is achieved using ICG@hMnOx, offering an appealing strategy to overcome the longstanding trade‐off between biofilm penetration and bacterial capture capacity in antibacterial nanozymes. This work presents a significant advancement in the development of nanozyme‐based therapies for combating biofilm‐related bacterial infections.

Generalized broadband operation facilitates multifunction or multiband highly integrated applications, such as modern transceiver systems, where ultra-wideband bidirectional passive mixers are favored to avoid a complex up/down-conversion scheme. In this paper, a modified Ruthroff-type transmission line transformer (TLT) balun is presented to enhance the isolation of the mixer from the local oscillator (LO) to the radio frequency (RF). Compared to the conventional methods, the proposed Ruthroff-type architecture adopts a combination of shunt capacitors and parallel coupled lines to improve the return loss at the LO port, thus effectively avoiding the area consumption for the diode-to-balun impedance transformation while simultaneously providing a suitable point for IF extraction. In addition, a parallel compensation technique consisting of an inductor and resistor is applied to the RF balun to significantly improve the amplitude/phase balance performance over a wide bandwidth. Benefiting from the aforementioned operations, an isolation-enhanced 8–30 GHz passive double-balanced mixer is designed as a proof-of-principle demonstration via 0.15-micrometer GaAs p-HEMT technology. It exhibits ultra-broadband performance with 7 dB average conversion loss and 50 dB LO-to-RF isolation under 15 dBm LO power. The monolithic microwave integrated circuit area is 0.96 × 1.68 mm2 including all pads.

In a beamforming circuit for a modern broadband phased-array system, high accuracy and compactness have received sufficient attention as they are directly related to side lobe level and fabrication cost, respectively. In order to meet the low phase error required, this paper proposed an ultra-broadband 6-bit digital step switched-type attenuator (STA) with capacitive/inductive compensation networks. Compared to the conventional methods, the proposed technique employs an improved simplified T-structure with capacitive compensation networks, which simultaneously achieves low insertion loss and high-accuracy amplitude/phase control. In addition, on-chip level shifting circuit is integrated to avoid complex control schemes. The strategy of prioritizing return loss is adopted to alleviate the performance degradation caused by impedance mismatch after cascade. As a proof-of-principle demonstration, a wideband 6-bit STA with core area of only 0.5 mm × 1.8 mm was designed via 0.15-micrometer GaAs pHEMT technology. It exhibits ultra-broadband operation with a 31.5 dB amplitude tuning range and a 0.5 dB tuning step. The insertion loss of the reference state is 4–5.3 dB. The return loss is better than 15 dB for all the 64 states. The RMS amplitude and phase errors are less than 0.2 dB and 2° over the 10 to 20 GHz.

Abstract This study aimed to establish a nomogram for the prediction of cancer-specific survival (CSS) of CRC patients with synchronous LM. The final prognostic nomogram based on prognostic factors was evaluated by concordance index (C-index), time-dependent receiver operating characteristic curves, and calibration curves. In the training and validation groups, the C-index for the nomogram was 0.648 and 0.638, and the AUC was 0.793 and 0.785, respectively. The high quality of the calibration curves in the nomogram models for CSS at 1-, 3-, and 5-year was observed. The nomogram model provided a conventional and useful tool to evaluate the 1-, 3-, and 5-year CSS of CRC patients with synchronous LM.

Hot dry rock (HDR) is a kind of clean energy with significant potential. Since the 1970s, the United States, Japan, France, Australia, and other countries have attempted to conduct several HDR development research projects to extract thermal energy by breaking through key technologies. However, up to now, the development of HDR is still in the research, development, and demonstration stage. An HDR exploration borehole (with 236 °C at a depth of 3705 m) was drilled into Triassic granite in the Gonghe Basin in northwest China in 2017. Subsequently, China Geological Survey (CGS) launched the HDR resources exploration and production demonstration project in 2019. After three years of efforts, a sequence of significant technological breakthroughs have been made, including the genetic model of deep heat sources, directional drilling and well completion in high-temperature hard rock, large-scale reservoir stimulation, reservoir characterization, and productivity evaluation, reservoir connectivity and flow circulation, efficient thermoelectric conversion, monitoring, and geological risk assessment, etc. Then the whole-process technological system for HDR exploration and production has been preliminarily established accordingly. The first power generation test was completed in November 2021. The results of this project will provide scientific support for HDR development and utilization in the future.©2022 China Geology Editorial Office.

With an arid climate and shortage of water resources, the groundwater dependent ecosystems in the oasis–desert ecotone of the Shiyang River Watershed has been extremely damaged, and the water crisis in the oasis has become a major concern in the social and the scientific community. In this study, the degeneration characteristics of the groundwater ecological function was identified and comprehensive evaluated, based on groundwater depth data, vegetation quadrat and normalized difference vegetation index (NDVI) from Landsat program. The results showed that (1) the suitable groundwater depth for sustainable ecology in the Shiyang River Watershed is about 2-4 m; (2) the terms of degenerative, qualitative and disastrous stages of the groundwater ecological function are defined with the groundwater depths of about 5 m, 7 m and 10 m; (3) generally, the groundwater ecological function in the oasis-desert ecotone of the lower reaches of Shiyang River Watershed is weak with an area of 1 397.9 km2 identified as the severe deterioration region, which accounted 74.7% of the total area. In the meantime, the percentages of the good, mild and moderate deterioration areas of groundwater ecological function are 3.5%, 5.5% and 16.3%, respectively, which were mainly distributed in the Qingtu lake area and the southeastern area of the Shoucheng town; (4) the degradation and shrinkage of natural oasis could be attributed to the dramatic groundwater decline, which is generally caused by irrational use of water and soil resources. This study could provide theoretical basis and scientific support for the decision-making in environmental management and ecological restoration of the Shiyang River Watershed.

Background Although endoscopic submucosal dissection (ESD) is considered to be a curative treatment for early colorectal cancer, additional surgery with lymph node dissection is routinely recommended for patients treated in non-curative ESD, owing to the risk of residual cancer and lymph node metastasis (LNM). However, in clinical practice, few patients are found to have either residual cancer or LNM after additional surgery. Therefore, we conducted this study to determine the risk factors associated with residual cancer and LNM. Methods Patients with early colorectal cancer after non-curative ESD and additional surgery from January 2015 to May 2019 were retrospectively identified. Clinicopathological characteristics were collected to determine the predictors of residual cancer and LNM. Results A total of 62 patients were enrolled for analysis in this study. After additional surgery, residual cancer and LNM was detected in 12 patients (19.35%). Clinicopathological comparison of patients with the presence or absence of residual cancer and LNM demonstrated that piecemeal resection (80% vs. 14.04%, P

Hydrogeochemical processes that would occur in polluted groundwater and aquifer system, may reduce the sensitivity of Sr isotope being the indicator of hydraulic fracturing flowback fluids (HFFF) in groundwater. In this paper, the Dameigou shale gas field in the northern Qaidam Basin was taken as the study area, where the hydrogeochemical processes affecting Sr isotope was analysed. Then, the model for Sr isotope in HFFF-polluted groundwater was constructed to assess the sensitivity of Sr isotope as HFFF indicator. The results show that the dissolution can release little Sr to polluted groundwater and cannot affect the εSr (the deviation of the 87Sr/86Sr ratio) of polluted groundwater. In the meantime, cation exchange can considerably affect Sr composition in the polluted groundwater. The Sr with low εSr is constantly released to groundwater from the solid phase of aquifer media by cation exchange with pollution of Quaternary groundwater by the HFFF and it accounts for 4.6% and 11.0% of Sr in polluted groundwater when the HFFF flux reaches 10% and 30% of the polluted groundwater, respectively. However, the Sr from cation exchange has limited impact on Sr isotope in polluted groundwater. Addition of Sr from cation exchange would only cause a 0.2% and 1.2% decrease in εSr of the polluted groundwater when the HFFF flux reaches 10% and 30% of the polluted groundwater, respectively. These results demonstrate that hydrogeochemical processes have little effect on the sensitivity of Sr isotope being the HFFF indicator in groundwater of the study area. For the scenario of groundwater pollution by HFFF, when the HFFF accounts for 5% (in volume percentage) of the polluted groundwater, the HFFF can result in detectable shifts of εSr (ΔεSr=0.86) in natural groundwater. Therefore, after consideration of hydrogeochemical processes occurred in aquifer with input of the HFFF, Sr isotope is still a sensitive indicator of the Quaternary groundwater pollution by the HFFF produced in the Dameigou shale of Qaidam Basin.

Abstract Endometrial carcinoma (EC) is a common malignancy of female genital system which exhibits a unique immune profile. It is a promising strategy to quantify immune patterns of EC for predicting prognosis and therapeutic efficiency. Here, we attempted to identify the possible immune microenvironment-related prognostic markers of EC. We obtained the RNA sequencing and corresponding clinical data of EC from TCGA database. Then, 3 immune scores based on the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm were computed. Correlation between above ESTIMATE scores and other immune-related scores, molecular subtypes, prognosis, and gene mutation status (including BRCA and TP53) were further analyzed. Afterwards, gene modules associated with the ESTIMATE scores were screened out through hierarchical clustering analysis and weighted gene co-expression network analysis (WGCNA). Differentially expressed analysis was performed and genes shared by the most relevant modules were found out. KEGG pathway enrichment analysis was conducted to explore the biological functions of those genes. Survival analysis was carried out to identify prognostic immune-related genes and GSE17025 database was further used to confirm the correlation between immune-related genes and the ImmuneScore. The immune-related scores based on ESTIMATE algorithm was closely related to the immune microenvironment of EC. 3 gene modules that had the closest correlations with 3 ESTIMATE scores were obtained. 109 immune-related genes were preliminarily found out and 29 pathways were significantly enriched, most of which were associated with immune response. Univariate survival analysis revealed that there were 14 genes positively associated with both OS and PFS. Among which, 11 genes showed marked correlations with ImmuneScore values in GSE17025 database. Our current study profiled the immune status and identified 14 novel immune-related prognostic biomarkers for EC. Our findings may help to investigate the complicated tumor microenvironment and develop novel individualized therapeutic targets for EC.

Due to the advantages of Synthetic Aperture Radar (SAR), the study of Automatic Target Recognition (ATR) has become a hot topic. Deep learning, especially in the case of a Convolutional Neural Network (CNN), works in an end-to-end way and has powerful feature-extracting abilities. Thus, researchers in SAR ATR also seek solutions from deep learning. We review the related algorithms with regard to SAR ATR in this paper. We firstly introduce the commonly used datasets and the evaluation metrics. Then, we introduce the algorithms before deep learning. They are template-matching-, machine-learning- and model-based methods. After that, we introduce mainly the SAR ATR methods in the deep-learning era (after 2017); those methods are the core of the paper. The non-CNNs and CNNs, that is, those used in SAR ATR, are summarized at the beginning. We found that researchers tend to design specialized CNN for SAR ATR. Then, the methods to solve the problem raised by limited samples are reviewed. They are data augmentation, Generative Adversarial Networks (GAN), electromagnetic simulation, transfer learning, few-shot learning, semi-supervised learning, metric leaning and domain knowledge. After that, the imbalance problem, real-time recognition, polarimetric SAR, complex data and adversarial attack are also reviewed. The principles and problems of them are also introduced. Finally, the future directions are conducted. In this part, we point out that the dataset, CNN architecture designing, knowledge-driven, real-time recognition, explainable and adversarial attack should be considered in the future. This paper gives readers a quick overview of the current state of the field.

Particulate polymer composites (PPCs) are widely applied under different elastic wave loading conditions in the automobile, aviation, and armor protection industries. This study investigates the elastic wave propagation behavior of a typical PPC, specifically a Cu/poly (methyl methacrylate) (PMMA) composite, with a wide range of particle contents (30–65 vol. %) and particle sizes (1–100 μm). The results demonstrate an inflection phenomenon in both the elastic wave velocity and attenuation coefficient with increasing volume content. In addition, the inflection point moves to the direction of low content with the increase in particle size. Notably, the elastic wave velocity, attenuation, and wavefront width significantly increased with the particle size. The inflection phenomenon of elastic wave propagation behavior in PPCs is demonstrated to have resulted from particle interaction using the classical scattering theory and finite element analysis. The particle interaction initially intensified and then reduced with increasing particle content. This study elucidates the underlying mechanism governing the elastic wave propagation behavior of high particle content PPCs and provides guidelines for the design and application of wave-absorbing composites.

Nuclear magnetic resonance spectroscopy was employed to monitor the change in chemical structures, olefin units (cis, trans and vinyl) and hydroxyl value on stabilized Hydroxyl‐terminated polybutadiene (HTPB) under accelerated ageing condition. Thermal ageing of HTPB was carried out at 65 °C for 10‐weeks and periodically withdrawn sample for NMR analysis. 1H and 13C NMR spectroscopy provided detailed structural information for all HTPB samples, including the quantification of olefin units and the determination of hydroxyl value. The analysis revealed a decrease in signal intensity, particularly for the olefin near or at the molecular end, suggesting that they were oxidized before those in the middle position within the chain. The quantitative assessment of olefin units indicates a slight decrease of 2 % in 1,2‐vinyl unit after 10‐weeks of ageing. The NMR spectra did not show any detectable signals corresponding to epoxides, peroxides or alcohols in any HTPB samples. However, a slight increase in the OH value was observed after 8 and 10 weeks of ageing, suggesting the possible incorporation of new hydroxyl groups due to thermal‐oxidation. The antioxidants used to stabilize HTPB exhibited limited effectiveness in preventing degradation reactions, even after 4 weeks of ageing at 65 °C. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is the most common joint disease in the elderly, characterized by cartilage degradation and proliferation of subchondral bone. The pathogenesis of OA involves a variety of inflammatory mediators, including nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β. From the molecular mechanism, the nuclear factor-erythroid 2-related factor (Nrf2)/heme oxygenase-1 (HO-1) pathway and the expression of ROS regulated the production of the above inflammatory mediators. Saikosaponin D (SSD), which is an active ingredient isolated from Bupleurum, has various biological functions. In this study, IL-1β was used as a pro-inflammatory factor to create an in vitro OA model. According to the results of high-density culture, qPCR, ROS measurement, Western blot, and immunofluorescence, SSD activated the Nrf2/HO-1/ROS axis, inhibited the production of inflammatory mediators, and protected against ECM destruction. The DMM mouse model was used as a model of OA in mice. From the results of safranin O/fast green staining, hematoxylin–eosin staining, tartrate-resistant acid phosphatase (TRAP) staining, and OARSI scores, SSD protected against the mice knee articular cartilage degeneration and reduced the number of osteoclasts in the subchondral bone. Experimental results found that SSD suppressed IL-1β–induced differentiated ATDC 5 chondrocytes apoptosis via the Nrf2/HO-1/ROS axis in vitro. SSD delayed the progression of OA in DMMs model mice in vivo. Therefore, SSD has the potential to become a drug for clinical treatment of OA.

We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5N6) (DK/GZ/S4184/17) (a clade 2.3.4.4d virus), A/chicken/Liaoning/SD007/2017(H5N1) (CK/LN/SD007/17) (a clade 2.3.2.1d virus), and A/chicken/Guangxi/SD098/2017(H7N9) (CK/GX/SD098/17), respectively. The protective efficacy of this novel vaccine and that of the recently used H5/H7 bivalent inactivated vaccine against different H5 and H7N9 viruses was evaluated in chickens. We found that the H5/H7 bivalent vaccine provided solid protection against the H7N9 virus CK/GX/SD098/17, but only 50–60% protection against different H5 viruses. In contrast, the novel H5/H7 trivalent vaccine provided complete protection against the H5 and H7 viruses tested. Our study underscores the importance of timely updating of vaccines for avian influenza control.