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Abstract Background Thoracic epidural anesthesia (TEA) is associated with a knowledge gap regarding its mechanisms in lung protection and reduction of postoperative pulmonary complications (PPCs). Driving pressure (ΔP), an alternative indicator of alveolar strain, is closely linked to reduced PPCs with lower ΔP values. We aim to investigate whether TEA contributes to lung protection by lowering ΔP during mechanical ventilation. Methods In this prospective, randomized, patient and evaluator-blinded parallel study, adult patients scheduled for elective major upper abdominal surgery were assigned to either the TEA group with combined thoracic epidural anesthesia and general anesthesia (TEA-GA) (n = 30) or the control group with only general anesthesia (GA) (n = 30). Measurements The primary outcome was the minimum ΔP determined based on positive end-expiratory pressure (PEEP) after intubation. Secondary outcomes included the incidence of PPCs within seven days, the minimum ΔP at various time points, blood gas analysis, intensive care unit (ICU) admission rates, length of hospital stay, and 30-day mortality rate. Results The TEA group had a significantly lower minimum ΔP titrated based on PEEP compared to the control group (11.23 ± 2.19 cmH2O vs. 12.67 ± 2.70 cmH2O; P = 0.028). Multivariate linear regression analysis showed that intraoperative TEA application (compared with its absence; unstandardized beta coefficient (B) = -1.289; P = 0.008) significantly correlated with ΔP. The incidence of PPCs did not differ significantly between the two groups (8 of 30 [26.7%] vs. 12 of 30 [40%]; P = 0.273), but the incidence of atelectasis in the TEA group was significantly lower than in the control group (5 of 30 [16.7%] vs. 12 of 30 [40.7%]; P = 0.012). Multivariate logistic regression analysis indicated that ΔP was the only variable significantly associated with PPCs (Adjusted Odds Ratio [OR] = 2.190; 95% Confidence Interval [CI]: 1.300 to 3.689; P = 0.003). Conclusion Compared to GA, TEA-GA can reduce intraoperative ΔP in patients undergoing major upper abdominal surgery, especially those undergoing laparoscopic surgery. However, compared to GA combined with ΔP-guided ventilation, TEA-GA combined with ΔP-guided ventilation does not reduce the risk of PPCs. There was no significant difference in the total use of various vasoactive drugs between the two groups. Trial registration This study was registered in the Chinese Clinical Trial Registry (registration number ChiCTR2300068778 date of registration February 28, 2023).

The intestinal mucus barrier is an important line of defense against gut pathogens. Damage to this barrier brings bacteria into close contact with the epithelium, leading to intestinal inflammation. Therefore, its restoration is a promising strategy for alleviating intestinal inflammation. This study showed that Abelmoschus manihot polysaccharide (AMP) fortifies the intestinal mucus barrier by increasing mucus production, which plays a crucial role in the AMP-mediated amelioration of colitis. IL-10-deficient mouse models demonstrated that the effect of AMP on mucus production is dependent on IL-10. Moreover, bacterial depletion and replenishment confirmed that the effects of AMP on IL-10 secretion and mucus production were mediated by Akkermansia muciniphila. These findings suggest that plant polysaccharides fortify the intestinal mucus barrier by maintaining homeostasis in the gut microbiota. This demonstrates that targeting mucus barrier is a promising strategy for treating intestinal inflammation.

Abstract Sleep deprivation (SD) is observed to adversely affect the reproductive health of women. However, its precise physiological mechanisms remain largely elusive. In this study, using a mouse model of SD, it is demonstrated that SD induces the depletion of ovarian primordial follicles, a phenomenon not attributed to immune‐mediated attacks or sympathetic nervous system activation. Rather, the excessive secretion of stress hormones, namely norepinephrine (NE) and epinephrine (E), by overactive adrenal glands, has emerged as a key mediator. The communication pathway mediated by the KIT ligand (KITL)‐KIT between granulosa cells and oocytes plays a pivotal role in primordial follicle activation. SD heightened the levels of NE/E that stimulates the activation of the KITL‐KIT/PI3K and mTOR signaling cascade in an β2 adrenergic receptor (ADRB2)‐dependent manner, thereby promoting primordial follicle activation and consequent primordial follicle loss in vivo. In vitro experiments further corroborate these observations, revealing that ADRB2 upregulates KITL expression in granulosa cells via the activation of the downstream cAMP/PKA pathway. Together, these results reveal the significant involvement of ADRB2 signaling in the depletion of ovarian primordial follicles under sleep‐deprived conditions. Additionally, ADRB2 antagonists are proposed for the treatment or prevention of excessive activation of primordial follicles induced by SD.

BackgroundUnder the guidance of achieving carbon peaking and carbon neutrality goals, the demand for lithium-ion batteries has increased significantly. However, during the production, use, and maintenance of lithium-ion batteries, workers are inevitably exposed to various occupational hazards, and some chemicals are nephrotoxic. ObjectiveTo evaluate the kidney function and potential determinants among male workers in a lithium-ion battery-related enterprise in Shanghai. MethodsThe data of occupational health examination carried out by an occupational disease prevention and control institution for workers in a lithium-ion battery-related enterprise in Shanghai were collected. The workers participating pre-employment occupational health examination were treated as a control group, and the other group was recruited from those participating periodic health examination. Serum creatinine, urea nitrogen, uric acid, and renal ultrasound were used to assess the kidney function of workers. Kidney function was classified according to the reference range of kidney function indicators in Diagnostics (9th Edition, national planning textbook for high education in medicine). Binary logistic regression and generalized linear regression were used to identify potential determinants of abnormal values in kidney function indicators in workers. ResultsThere were 6184 workers in the control group (pre-employment) with a mean age of (27.40±4.50) years. There were 3526 workers on the job with a mean age of (29.40±4.99) years and the median time of service was 2.00 (1.00, 3.42) years. The prevalence rates of high serum creatinine, high urea nitrogen, and high uric acid, and abnormal kidney ultrasound among the control group were 0.66%, 2.47%, 30.32%, and 10.12%, respectively; the indicators in the on-the-job workers were 0.96%, 3.35%, 38.25%, and 12.68%, respectively, significantly higher than those in the control group (P1-3 years, OR=1.747, 95%CI: 1.494, 2.042; >3 years, OR=1.866, 95%CI: 1.511, 2.304), hypertension (OR=1.400, 95%CI: 1.055, 1.859), and hyperglycemia (OR=1.565, 95%CI: 1.221, 2.006). Workers who were older (OR=1.038, 95%CI: 1.022, 1.054) and had longer working years (>1-3 years, OR=1.518, 95%CI: 1.201, 1.920), occasional smoking habits (OR=1.239, 95%CI: 1.039, 1.478), regular drinking habits (OR=1.875, 95%CI: 1.139, 3.087), and hypertension (OR=1.465, 95%CI: 1.075, 1.998) were at a higher risk of renal ultrasound abnormalities. The generalized linear models showed that length of service (>1-3 years, β=1.120, 95%CI: 0.360, 1.880; >3 years, β=1.451, 95%CI: 0.543, 2.358), smoking status (occasional, β=0.818, 95%CI: 0.156, 1.479; regular, β=0.841, 95%CI: 0.066, 1.616), and hypertension (β=2.742, 95%CI: 1.390, 4.094) were the influencing factors of serum creatinine concentration in the workers. Age (β=0.014, 95%CI: 0.009, 0.019) and length of service (>1-3 years, β=0.079, 95%CI: 0.012, 0.146) were the influencing factors of urea nitrogen. Age (β=−1.759, 95%CI: −2.288, −1.231), length of service (≤1 year, β=10.676, 95%CI: 4.035, 17.316; >1-3 years, β=26.117, 95%CI: 19.962, 32.272; >3 years, β=34.558, 95%CI: 26.116, 43.001), hypertension (β=23.162, 95%CI: 11.617, 34.707), and hyperglycemia (β=15.017, 95%CI: 4.853, 25.180) were the influencing factors of uric acid. ConclusionThe prevalence of abnormal kidney function of workers in selected lithium-ion battery-related enterprise is varied by age, length of service, smoking status, drinking status, hypertension, and hyperglycemia. There may be a trend that the longer the time working in a lithium-ion battery-related enterprise, the worse the workers' kidney function. Therefore, the enterprise should pay attention to the possible reasons for their changes and take targeted interventions.

ObjectiveTo analyze the genomic characteristics of the monkeypox virus (MPXV) strains isolated from local cases in Ji′nan city, Shandong province. MethodsBlood serum and vesicular fluid samples from suspected cases of MPXV infection reported in Ji′nan city from June to October 2023 were tested for MPXV nucleic acids. The complete genome sequence of MPXV was obtained using whole-genome sequencing (WGS) technology. Molecular genetic evolution of the MPXV genome sequence was performed using Mega 11 software, Bioedit software, and the Nextclade online comparison website. Systematic phylogenetic trees and nucleotide and amino acid sequence mutation analyses were performed. ResultsIn this study, the complete genome sequences of 7 strains of MPXV isolated from the cases in Ji′nan city were obtained by WGS, with a total genome length of 196 858 bp. The online comparison results uploaded to the Nexttrade website showed that all of them belonged to the IIb branch of the West African branch, and the lineage classification was C.1. The number of nucleotide variations with a depth greater than 50% is 86, and the total number of variations with an effect of ≥ intermediate is 39. ConclusionThe evolutionary distance between the sequences of MPXV strains isolated in Ji′nan city and those in China is relatively close, belonging to the same evolutionary branch, and no new branches have been found.

BackgroundPhotovoltaic (PV) cells can convert solar energy into electricity and alleviate the dilemma of energy supply shortage. Shanghai's PV module industry is booming, but there are few reports on the health status of the workers and there is an urgent need for health risk assessment. ObjectiveTo evaluate the health status of PV module production workers and the association between work and health status, in order to provide a direction for the health management of the workers. MethodsAmong the PV module production workers who completed prescriptive occupational health examination by a designated medical institution in 2021, 2453 workers with more than one year of working age were selected as the exposure group and 538 newly hired workers as the control group. On the basis of the Technical specifications for occupational health surveillance (GBZ 188−2014), the health examination included physical examination and laboratory examination and information such as sociodemographics, living habits, and disease history. We compared the indicators of pure-tone hearing test, blood routine examination, electrocardiogram (ECG), liver function, and kidney function between the two groups. The blood routine results included erythrocyte-related indicators, leukocyte-related indicators, and platelet-related indicators, and the results of liver function included hepatocyte injury indicators, hepatic secretory function indicators, and hepatic synthesis function indicators. The workers were divided into four groups by quartiles of working age. Trend chi-square test was used to analyze differences in health status between the four working age groups. Multiple logistic regression models were used to evaluate the association between working age and health indicators. ResultsAmong the exposure group workers, 2035 (83.0%) were male and 418 (17.0%) were female. The median (P25, P75) age was 34.0 (30.0, 39.0) years and the median (P25, P75) working age was 6.0 (3.0, 10.0) years. The abnormality rate of blood routine was 61.7%. Among them, the abnormality rates of platelet-related indicators and liver secretory function indicators were 39.8% and 48.1% respectively. The risks of abnormal hepatocyte injury-related indicators, fatty liver, and platelet-related indicator abnormalities among the exposure group were 1.471 (95%CI: 1.060, 2.054), 1.691 (95%CI: 1.208, 2.385), and 7.576 (95%CI: 4.967, 11.994) times higher than those in the control group respectively. The single-factor analysis demonstrated a positively linear trend between working age and hypertension prevalence, electrical audiometry abnormality rate, or liver secretory function indicator abnormality rate. Corrected for gender, age, smoking status, hypertension, etc., the results of logistic analysis showed that quartile working age was positively related to abnormal liver secretion function and abnormal platelet-related indicators respectively (OR=1.047, P=0.005; OR=1.037, P=0.014), and inversely associated with the abnormal rate of renal function (OR=0.953, P=0.044). ConclusionNegative associations between health status and working age are identified in PV module production workers. The target PV module production employees are in younger age, and with the increase of working age, the abnormalities of liver function and platelets may increase. Therefore, the enterprises should extend occupational health work from workplace to workers.

This study presents a compact dual-band dual-sense circularly polarized (CP) fragmental patch antenna that advanced by an improved simulated-annealing-based optimization algorithm. This design replaces truncated corners of traditional truncated patch antennas with fragmental structures, generating dual-band dual-CP radiation with a small frequency ratio and a high front-to-back ratio. The proposed optimized framework tackles the multi-objective optimization problem through hierarchical optimization to achieve an optimal balance among various performance metrics. Furthermore, the simulated annealing is improved using a matrix-based dynamic step-size perturbation mechanism and a nested cyclic process, averting premature convergence and ensuring multifaceted objective enhancement. The measurement results reveal that the proposed antenna can operate with a small frequency ratio of 1.07, providing left-hand CP radiation from 4.99 to 5.02 GHz and right-hand CP radiation 5.34 to 5.41 GHz, respectively. This compact cost-efficient design demonstrates potential for diverse antenna applications.

Free-space optical (FSO) communication technology is widely utilized in uncrewed aerial vehicle (UAV) communication because it provides larger communication bandwidth than radio frequency technology. However, the system performance of FSO-based UAV communication systems is severely affected by several adverse factors, such as atmospheric turbulence, fog-induced absorption, and pointing errors, all of which result in performance deterioration drastically. This study proposes a multi-UAV optical communication system to suppress the influence of the foggy channel and pointing error impairments under atmospheric turbulence with a Málaga distribution, with both amplify-and-forward (AF) and decode-and-forward (DF) protocols, respectively. Specifically, some critical statistical expressions, such as probability and cumulative density functions, were derived, which were employed to assess the performance metrics, including outage probability, average bit error rate, and ergodic capacity. Additionally, these performance metrics obtained through theoretical analysis in the presence of atmospheric turbulence, fog absorption, and pointing errors were corroborated by Monte Carlo simulations. Finally, the performance indicators under AF and DF relay protocols were compared.

Abstract Background Exposure to a harsh ovarian microenvironment induced by chemotherapeutic agents seriously affects the remodeling of ovarian function and follicular development, leading to premature ovarian failure or insufficiency (POF/POI). For decades, the effectiveness of stem cell therapies in POI animal models has been intensively studied; however, strategies to enhance the therapeutic effect of stem cells remain challenging. Methods In this study, we first observed the pathological changes of the ovaries at different time points during chemotherapy, including the number of follicles, granulosa cell proliferation, oxidative stress damage, ovarian fibrosis, and inflammatory reaction. Moreover, we investigated whether activated hAECs stimulated by the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were more effective than native hAECs in repairing ovarian injury induced by chemotherapy. Results The inhibitory effect of chemotherapy drugs on ovarian granulosa cells (GCs) in growing follicles mainly occurred on day 3 after chemotherapy in a mouse model. Then, continued ovarian injury, including oxidative damage and cell death cascades, resulted in the depletion of follicular reserves and inflammation-related ovarian fibrosis. Cytokine array demonstrated that activated hAECs secreted high levels of paracrine cytokines related to extracellular matrix (ECM) remodeling, angiogenesis, and immunomodulation. An in vivo study showed that the engraftment rate of activated hAECs in damaged ovaries was higher than that of native hAECs. Furthermore, activated hAECs in damaged ovaries had significantly upregulated expression of the antioxidant proteins thioredoxin1/2. In addition, activated hAECs had increased numbers of mature follicles and ameliorated the ovarian microenvironment by promoting angiogenesis and reducing ovarian fibrosis. Conclusions These results indicated that secondary ovarian damage induced by chemotherapy, including oxidative stress damage, chronic inflammatory response, and ovarian tissue fibrosis should be attended. Prestimulation with the proinflammatory factors TNF-α and IFN-γ could enhance the therapeutic efficacy of hAECs against chemotherapy-induced ovarian dysfunction, which may become a new feasible strategy to improve the therapeutic potential of hAECs in regenerative medicine. Graphical Abstract

Abstract Background An understanding of the impact of goal-directed fluid therapy (GDFT) on the outcomes of patients undergoing one-lung ventilation (OLV) for thoracic surgery remains incomplete and controversial. This meta-analysis aimed to assess the effect of GDFT compared to other fluid therapy strategies on the incidence of postoperative complications in patients with OLV. Methods The Embase, Cochrane Library, Web of Science, and MEDLINE via PubMed databases were searched from their inception to November 30, 2022. Forest plots were constructed to present the results of the meta-analysis. The quality of the included studies was evaluated using the Cochrane Collaboration tool and Risk Of Bias In Non-Randomized Study of Interventions (ROBINS-I). The primary outcome was the incidence of postoperative complications. Secondary outcomes were the length of hospital stay, PaO2/FiO2 ratio, total fluid infusion, inflammatory factors (TNF-α, IL-6), and postoperative bowel function recovery time. Results A total of 1318 patients from 11 studies were included in this review. The GDFT group had a lower incidence of postoperative complications [odds ratio (OR), 0.47; 95% confidence interval (95% CI), 0.29–0.75; P = 0.002; I 2, 67%], postoperative pulmonary complications (OR 0.48, 95% CI 0.27–0.83; P = 0.009), and postoperative anastomotic leakage (OR 0.51, 95% CI 0.27–0.97; P = 0.04). The GDFT strategy reduces total fluid infusion. Conclusions GDFT is associated with lower postoperative complications and better survival outcomes after thoracic surgery for OLV.

The scarcity of hematopoietic stem cells (HSCs) restricts their use in both clinical settings and experimental research. Here, we examined a recently developed method for expanding rigorously purified murine HSCs ex vivo. After 3 weeks of culture, only 0.1% of cells exhibited the input HSC phenotype, but these accounted for almost all functional long-term HSC activity. Input HSCs displayed varying potential for ex vivo self-renewal, with alternative outcomes revealed by single-cell multimodal RNA and ATAC sequencing profiling. While most HSC progeny offered only transient in vivo reconstitution, these cells efficiently rescued mice from lethal myeloablation. The amplification of functional HSC activity allowed for long-term multilineage engraftment in unconditioned hosts that associated with a return of HSCs to quiescence. Thereby, our findings identify several key considerations for ex vivo HSC expansion, with major implications also for assessment of normal HSC activity.

Automatic and accurate instance segmentation of street trees from point clouds is a fundamental task in urban green space research. Previous studies have achieved satisfactory tree segmentation results in simple scenarios. However, for challenging cases, including adjacent overlapping tree crowns, irregular tree shapes, and incompleteness caused by occlusion, most methods show under- or over-segmentation effects. In this study, an automated two-stage framework (tree extraction and individual tree segmentation) using vehicle-mounted mobile laser scanning (MLS) point clouds is developed to robustly detect single roadside trees. In the first stage, the ground points are filtered to reduce the processing time. Subsequently, an improved graph-based semantic segmentation network extracts roadside tree points from the urban scenes. For individual tree segmentation, a segmentation strategy combining cylindrical convolution and dynamic shift detects instance-level roadside trees. A simple road environment and two complex urban areas are used to verify the performance of the individual urban tree segmentation. The proposed method achieves 84–92% overall segmentation accuracy of the roadside tree point clouds and significantly outperforms existing methods in various challenging cases. Some applications can benefit from individual tree segmentation. For instance, the 3D green volume is calculated at the level of individual urban trees. The proposed method provides a practical solution for ecological assessment based on the 3D green volume of urban roads.

Change Detection (CD) is the process of recognizing and quantitatively evaluating changes in surface objects at the exact location but at different times from remote sensing images that may be caused by extreme heat events. Attention-based CD methods have gained much traction because of their ability to concentrate on change regions. However, most current attention-based methods only calculate the attention matrix based on features extracted from a single image but fail to consider the correlation of features extracted from images at different times. The effectiveness of the correlation of learned features from change regions in bi-temporal images is an essential element influencing the improvement of CD performance. This paper proposes a Cascaded Attention-Induced Difference Representation Learning (CADRL) method for multispectral CD to explore the correlation of features extracted from bi-temporal images to obtain more discriminative features. The proposed CADRL method contains three modules: the feature extraction module, the Cascaded Cross-attention based Difference Learning Module (CCADLM) and the detection module. First, the feature extraction module extracts multi-scale features from bi-temporal images. Then, CCADLM generates more discriminative features by fusing difference features and the cross-attention matrix learned from the temporal attention unit from multiple levels to explore the correlation information of change regions in bi-temporal images. Finally, the learned discriminative features are fed to the detection module to gain the final detection map. Experimental results on three multispectral datasets demonstrate that the CADRL method outperforms other existing CD algorithms.

Summary: Aging negatively affects hematopoiesis, with consequences for immunity and acquired blood cell disorders. Although impairments in hematopoietic stem cell (HSC) function contribute to this, the in vivo dynamics of such changes remain obscure. Here, we integrate extensive longitudinal functional assessments of HSC-specific lineage tracing with single-cell transcriptome and epitope profiling. In contrast to recent suggestions from single-cell RNA sequencing alone, our data favor a defined structure of HSC/progenitor differentiation that deviates substantially from HSC-derived hematopoiesis following transplantation. Native age-dependent attrition in HSC differentiation manifests as drastically reduced lymphoid output through an early lymphoid-primed progenitor (MPP Ly-I). While in vitro activation fails to rescue lymphoid differentiation from most aged HSCs, robust lymphopoiesis can be achieved by culturing elevated numbers of candidate HSCs. Therefore, our data position rare chronologically aged HSC clones, fully competent at producing lymphoid offspring, as a prime target for approaches aimed to improve lymphopoiesis in the elderly.

As a promising technology, free-space optical (FSO) communication plays an important role in the next generation of wireless communication. A dual-hop FSO communication system with decode-and-forward (DF) protocol is proposed in this paper, considering the influences of the atmospheric turbulence (AT), atmospheric absorption and pointing error impairments, in which the Málaga distribution model is used to characterize the fading caused by AT in each link. The end-to-end statistical expressions of our proposed dual-hop Málaga-Málaga communication system are derived, such as the cumulative distribution function (CDF), probability density function and moment generating function. Thereafter, using the above statistical results, the accurate end-to-end expressions of outage probability, average bit error rate (ABER) and ergodic capacity are deduced under the direct detection intensity modulation and heterodyne detection techniques. Furthermore, the end-to-end asymptotic expressions for CDF and the ABER at high signal-to-noise ratio as well as simplified expressions from simple basic functions are obtained. The effects of different AT and pointing error impairments conditions on the proposed system are analyzed based on theoretical and numerical results. Finally, Monte Carlo simulation results indicate that all our novel deduced expressions are basically consistent with the numerical results.

The well-known magnetoelectric dipole (ME-dipole) has huge adoption in antenna designs. In this paper, we manage to implement ME-dipoles in metasurfaces. The unit cell of an ME-dipole metasurface consists of a cross slot etched on the middle metal layer and an ME-dipole loaded on each side of the middle metal layer. The unit cell of an ME-dipole metasurface is designed based on the antenna theory, i.e., one ME-dipole works as a receiving antenna while the other ME-dipole works as a transmitting antenna. The metasurface is then formed by arraying these unit cells in a periodic grid with optimal cell size. Three ME-dipole metasurfaces, including a frequency selective surface (FSS), a polarizer, and a transmitarray, are presented to show the potential of the proposed metasurface design method. The proposed concept and the design method are validated using simulation as well as experiments.

Abstract In clustered distributed storage systems (CDSSs), one of the main design goals is minimizing the transmission cost during the failed storage nodes repairing. Generalized regenerating codes (GRCs) are proposed to balance the intra‐cluster repair bandwidth and the inter‐cluster repair bandwidth for guaranteeing data availability. The trade‐off performance of GRCs illustrates that, it can reduce storage overhead and inter‐cluster repair bandwidths simultaneously. However, in practical big data storage scenarios, GRCs cannot give an effective solution to handle the heterogeneity of bandwidth costs among different clusters for node failures recovery. This paper proposes an asymmetric bandwidth allocation strategy (ABAS) of GRCs for the inter‐cluster repair in heterogeneous CDSSs. Furthermore, an upper bound of the achievable capacity of ABAS is derived based on the information flow graph (IFG), and the constraints of storage capacity and intra‐cluster repair bandwidth are also elaborated. Then, a metric termed global repair bandwidth cost (GRBC), which can be minimized regarding of the inter‐cluster repair bandwidths by solving a linear programming problem, is defined. The numerical results demonstrate that, maintaining the same data availability and storage overhead, the proposed ABAS of GRCs can effectively reduce the GRBC compared to the traditional symmetric bandwidth allocation schemes.

Given the lack of a standardized evaluation system for the infrared jamming effectiveness of false targets, this paper first uses a co-saliency detection model to extract the main parts of the true and false targets. Then the perceptual similarity algorithm is improved by combining the operational requirements of false targets in the infrared band. Finally, a background-independent evaluation model for infrared jamming effectiveness of false targets is constructed. The experimental results show that the model can quantitatively reflect the infrared jamming effectiveness of a single false target and distinguish the infrared jamming effectiveness of different types of false targets. In addition, the model has stronger robustness than traditional evaluation models.

Morel is a popular edible mushroom with considerable medicinal and economic value which has garnered global popularity. However, the increasing heavy metal (HM) pollution in the soil presents a significant challenge to morels cultivation. Given the susceptibility of morels to HM accumulation, the quality and output of morels are at risk, posing a serious food safety concern that hinders the development of the morel industry. Nonetheless, research on the mechanism of HM enrichment and mitigation strategies in morel remains scarce. The morel, being cultivated in soil, shows a positive correlation between HM content in its fruiting body and the HM content in the soil. Therefore, soil remediation emerges as the most practical and effective approach to tackle HM pollution. Compared to physical and chemical remediation, bioremediation is a low-cost and eco-friendly approach that poses minimal threats to soil composition and structure. HMs easily enriched during morels cultivation were examined, including Cd, Cu, Hg, and Pb, and we assessed soil passivation technology, microbial remediation, strain screening and cultivation, and agronomic measures as potential approaches for HM pollution prevention. The current review underscores the importance of establishing a comprehensive system for preventing HM pollution in morels.

To solve the problem of low resource utilization of the traditional two-way communication network with unmanned aerial vehicle (UAV) as relays, a resource optimization algorithm based on physical-layer network coding was proposed.Considering the transmission power constraints of the UAV relay communication network, the maximum speed constraints of the UAV and the synchronization requirements of the physical-layer network coding, a resource allocation model for joint optimization of transmission power and UAV trajectory design was formulated to minimize the system outage probability.By decoupling the original non-convex problem into two sub-problems, an iterative algorithm was proposed to realize the joint implementation of optimal trajectory design and optimal system power distribution based on the Karush-Kuhn-Tucker (KKT) conditions, Lagrangian duality method and subgradient method.Simulation results show that the proposed algorithm can significantly improve the system performance and reduce the possibility of communication interruption.

Aspergillus fungi can produce a wide range of secondary metabolites, and they have represented a potential resource of novel bioactive compounds. Bacterial plant diseases have a serious impact on the sustainable development of agriculture worldwide, so it is necessary to use natural antibacterial compounds in microorganisms to control plant pathogens. This study was conducted to investigate the bioactive compounds of Aspergillus niger xj, three plant pathogens (Agrobacterium tumefaciens T-37, Erwinia carotovora EC-1, and Ralstonia solanacearum RS-2) were used as indicator bacteria, according to the biological activity tracking, five compounds were isolated from A. niger xj spore powder, and characterization of compounds was done by NMR (1H-NMR and 13C-NMR) and EI-MS and was identified as ergosterol (1), β-sitosterol (2), 5-pentadecylresorcinol (3), 5-hydroxymethyl-2-furancarboxylic acid (4), and succinimide (5). Compounds 3 and 5 were isolated from A. niger xj for the first time. The minimum inhibitory concentration (MIC) of five compounds against three plant pathogens was evaluated, the results showed that compound 4 exhibited the strongest antibacterial activity against tested bacteria, and RS-2 was the most sensitive to compound 4, showing the lowest MIC of 15.56 μg/ml. We concluded that the mechanism of action of the compound 4 against RS-2 might be described as compound 4 acting on bacterial protein synthesis and intracellular metabolism according to the results of the scanning electron microscopy observation, permeability of cell membrane and SDS-PAGE. These results indicated that compound 4 has good potential to be as a biocontrol agent. In conclusion, the results from this study demonstrated that the compounds with antibacterial activity are of great significance of the prevention and control of plant phytopathogenic bacteria, and they may be applicable to exploring alternative approaches to integrated control of phytopathogens.

Abstract This work introduces an efficient neuron design for fixed‐point artificial neural networks with the rectified linear unit (ReLU) activation function for energy‐constrained wireless applications. The fixed‐point binary numbers and ReLU activation function are used in most application‐specific integrated circuit designs and artificial neural networks (ANN), respectively. It is well known that, owing to involved computation intensive tasks, the computational burden of ANNs is ultra heavy. Consequently, many practitioners and researchers are discovering the ways to reduce implementation complexity of ANNs, particularly for battery‐powered wireless applications. For this, a low‐complexity neuron to predict the sign bit of the input of the non‐linear activation function, ReLU, by employing the saturation characteristics of the activation function is proposed. According to our simulation results based on random data, computation overhead of a neuron using the proposed technique can be saved by a ratio of 29.6% compared to the conventional neuron using a word length of 8 bits without apparently increasing the prediction error. A comparison of the proposed algorithm with the popular 16‐bit fixed‐point format of the convolutional network, AlexNet, indicates that the computation can be saved by 48.58% as well.

Abstract An efficient modes analyses technique for isotropic or anisotropic material filled 2D metallic waveguides with an arbitrary contour using the multifilament current method (MFCM) is presented. The ideal PEC boundary of a 2D waveguide is replaced by a shell with a high conductivity and electrical small thickness. The thin lossy shell not only can well approximate the boundary condition of PEC waveguide wall therefore without altering the initial waveguide modes, but also can let the external excitation penetrate through to excite the inside modes, resulting in a high internal field intensity at the frequency of each mode. In this case, the modes are revealed by the peaks of field intensity responses, and the spurious modes which existed in traditional source‐free modes determination techniques can be completely avoided. Based on this idea, a generalized impedance boundary condition (GIBC) is formulated to represent the lossy waveguide wall and further utilized in the MFCM for simulating the internal field intensity over frequency. Three different configurations of a 2D waveguide are considered. The computed modes are compared with that obtained from commercial software, and an excellent agreement is achieved, yet an competitive advantage on simulation performances is observed by using the proposed technique.

A crude extract (B10) of Aspergillus niger spores showed effective antibacterial activity against Agrobacterium tumefaciens T-37. The inhibition rate was 98.22%, and the half maximal inhibitory concentration was 0.035 ± 0.018 mg/mL. To study the primary antibacterial mechanism, this study used relative electric conductivity, release of proteins and nucleic acids, sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) and detection of reactive oxygen species (ROS). After adding B10, the relative electric conductivity increased in the supernatant indicating electrolyte transport from intracellular to extracellular space. Compared with the control group and the benzylpenicillin potassium (BP) group, the B10 group had a significant increase in extracellular nucleic acid and protein within 0–18 h, showing that the cell and cytoplasmic membranes were damaged by B10. The SDS–PAGE results confirmed that the extracellular protein and nucleic acid levels were in agreement with lower intracellular total protein. Finally, the intracellular levels of ROS indicated that B10 caused an increase in ROS. In summary, B10 showed clear antibacterial activity against A. tumefaciens through damaging cytoplasmic membranes. The research provided a scientific basis for the prevention and treatment of bacteria.

BackgroundHypoxemia and fluctuations in respiratory mechanics parameters are common during one-lung ventilation (OLV) in thoracic surgery. Additionally, the incidence of postoperative pulmonary complications (PPCS) in thoracic surgery is higher than that in other surgeries. Previous studies have demonstrated that driving pressure-oriented ventilation can reduce both mortality in patients with acute respiratory distress syndrome (ARDS) and the incidence of PPCS in patients undergoing general anesthesia. Our aim was to determine whether driving pressure-oriented ventilation improves intraoperative physiology and outcomes in patients undergoing thoracic surgery.MethodsWe searched MEDLINE via PubMed, Embase, Cochrane, Web of Science, and ClinicalTrials.gov and performed a meta-analysis to compare the effects of driving pressure-oriented ventilation with other ventilation strategies on patients undergoing OLV. The primary outcome was the PaO2/FiO2 ratio (P/F ratio) during OLV. The secondary outcomes were the incidence of PPCS during follow-up, compliance of the respiratory system during OLV, and mean arterial pressure during OLV.ResultsThis review included seven studies, with a total of 640 patients. The PaO2/FiO2 ratio was higher during OLV in the driving pressure-oriented ventilation group (mean difference [MD]: 44.96; 95% confidence interval [CI], 24.22–65.70.32; I2: 58%; P

Unlimited and seamless coverage as well as ultra-reliable and low-latency communications are vital for connected vehicles, in particular for new use cases like autonomous driving and vehicle platooning. In this paper, we propose a novel Space-Air-Ground integrated vehicular network (SAGiven) architecture to gracefully integrate the multi-dimensional and multi-scale context-information and network resources from satellites, High-Altitude Platform stations (HAPs), low-altitude Unmanned Aerial Vehicles (UAVs), and terrestrial cellular communication systems. One of the key features of the SAGiven is the reconfigurability of heterogeneous network functions as well as network resources. We first give a comprehensive review of the key challenges of this new architecture and then provide some up-to-date solutions on those challenges. Specifically, the solutions will cover the following topics: (1) space-air-ground integrated network reconfiguration under dynamic space resources constraints; (2) multi-dimensional sensing and efficient integration of multi-dimensional context information; (3) real-time, reliable, and secure communications among vehicles and between vehicles and the SAGiven platform; and (4) a holistic integration and demonstration of the SAGiven. Finally, it is concluded that the SAGiven can play a key role in future autonomous driving and Internet-of-Vehicles applications.

With the increasing of the number of edge-devices and the demand of real-time experience, the end-edge-cloud hierarchical storage system (EECHSS) is emerged recently for reliable caching and fast offloading of massive amounts of data. EECHSS can accommodate various services, save computing power and improve storage capacity, due to transformation from central-cloud to edge-cloud, considerable reducing service delay and communication overhead. One of the main challenges brought by edge-cloud architecture is consistency problem. It is difficult to guarantee that the data from the two distributed clusters is consistent by existing consistency protocols. In addition, as the variety of applications increases, the existing fixed consistency level of classical protocols can no longer satisfy the system dynamic requirements. In this paper, we focus on designing grouping-based consistency protocols with adaptively selecting consistency level in EECHSS. At first, we analyze the internal structure and the workflow of EECHSS, and devise two modified adaptive grouping-based consistency protocols (GM-Paxos and GEPaxos) with efficient grouping algorithms. Then, for the characteristics that data is offloaded frequently, we design two synchronization strategies to ensure the consistency of the data cached in the edge-cloud and the central-cloud, respectively. Experiments show that, our proposed grouping-based consistency protocols of EECHSS can improve the availability as much as possible while ensuring data consistent.

The formulations for three-dimensional (3D) scattering from uniaxial objects with a smooth boundary using a multiple infinitesimal dipole method (MIDM) are introduced. The proposed technique uses two sets of infinitesimal dipole triplets (IDTs), including three co-located orthogonally polarized electric infinitesimal dipoles, distributed inside and outside of a scatterer to construct simulated fields. The dyadic Green's functions of uniaxial materials are deployed in the MIDM so as to obtain the simulated fields. The singularity issues in using the uniaxial dyadic Green's functions, which cannot be solved analytically so far for a general uniaxial medium, can be easily eliminated by using the proposed MIDM. In comparison to the traditional single-layered distribution scheme of IDTs, the proposed multiple-layered distribution scheme can handle the scattering from uniaxial objects accurately and efficiently. Several numerical examples are presented to study bistatic radar cross section (RCS) responses under different scenarios. Excellent agreement is achieved by comparing numerical results with those obtained from commercial software packages, while the simulation performance including CPU time and required memory is drastically improved by using the MIDM when computing a general uniaxial material or a relatively larger object. The proposed technique has its merits on simplicity, conciseness and fast computation in comparison to existing numerical methods.

We present a multifilament current method (MFCM) incorporated with generalized sheet transition condition (GSTC) to simulate 2.5-dimensional cylindrical metasurfaces with arbitrary cross sections for the first time. The chain-type form of GSTC is synthesized and utilized to relate the tangential fields on two sides of a cylindrical metasurface. The MFCM is subsequently introduced and formulated by deploying the GSTC. The doublet-current unit which contains both electric and magnetic line sources with phase terms is deployed in the MFCM for simulating co- and cross-polarized scattered and transmitted fields from GSTC characterized cylindrical metasurfaces. Three illustrative examples regarding different geometries, different metasurface characteristics and different excitations are presented to validate the proposed simulation technique. In comparison to existing numerical methods, the proposed technique has its merits on simplicity and conciseness.

The mileage of China’s high-speed railways is increasing, and trains running only during the day cannot satisfy the need. In the existing train organization and maintenance modes, overnight trains and maintenance constructions strongly interact with each other and are difficult to coordinate. Although some overnight trains run on a high-speed railway (HSR), currently, they are all sunset-departure and sunrise-arrival trains, and none of them depart in the night by passenger’s habits. Only a one-way line is occupied by night, except rendezvous; the opposite direction line resources are idled. According to this feature, a double-track one-direction mode on the HSR was proposed based on the reverse running ability of the train control system to coordinate the train operation and maintenance. A mathematical model was established, and a heuristic algorithm based on simulated annealing was designed. The validity of the model was verified on the section from Xuzhoudong to Xi’anbei of Xuzhou-Lanzhou HSR, as an example. The results showed that 10 pairs of overnight sleeper trains and some freight trains can run, and the maintenance disruption is not less than 180 min. The proposed method can provide a new method to coordinate the overnight operation and maintenance of the HSR and increase the capacity of HSRs.

Forward osmosis membrane technology (FO) shows potential application prospects in biogas slurry concentration, which is conducive to promoting the sustainable development of biogas projects. However, at present, the key influencing factors of membrane concentration using FO are not well understood. Therefore, this study analyzed the influence of draw solution concentration, pH, temperature and cross-flow velocity on the concentration efficiency of FO membrane, and optimized the operation parameters of FO membrane. The results showed that the concentration effect of the NaCl draw solution at pH 5 or 9 was better than that at pH 7. The order of factor influencing the water flux was as follows: draw liquid concentration > cross-flow velocity > operating temperature. The optimal combination obtained by orthogonal analysis was under 45 °C, with a cross-flow velocity of 1 L/min and the use of 1.5 mol/L NaCl as draw solution. The results of the membrane cleaning implied that the recovery rate of the fouled membrane after acid–base cleaning is significantly higher (88%) than other cleaning solutions. This research offers a scientific reference for applying positive osmosis technology to re-utilize biogas slurry resources.

Epigenetic mechanisms are gatekeepers for the gene expression patterns that establish and maintain cellular identity in mammalian development, stem cells and adult homeostasis. Amongst many epigenetic marks, methylation of histone 3 lysine 4 (H3K4) is one of the most widely conserved and occupies a central position in gene expression. Mixed lineage leukemia 1 (MLL1/KMT2A) is the founding mammalian H3K4 methyltransferase. It was discovered as the causative mutation in early onset leukemia and subsequently found to be required for the establishment of definitive hematopoiesis and the maintenance of adult hematopoietic stem cells. Despite wide expression, the roles of MLL1 in non-hematopoietic tissues remain largely unexplored. To bypass hematopoietic lethality, we used bone marrow transplantation and conditional mutagenesis to discover that the most overt phenotype in adult Mll1-mutant mice is intestinal failure. MLL1 is expressed in intestinal stem cells (ISCs) and transit amplifying (TA) cells but not in the villus. Loss of MLL1 is accompanied by loss of ISCs and a differentiation bias towards the secretory lineage with increased numbers and enlargement of goblet cells. Expression profiling of sorted ISCs revealed that MLL1 is required to promote expression of several definitive intestinal transcription factors including Pitx1, Pitx2, Foxa1, Gata4, Zfp503 and Onecut2, as well as the H3K27me3 binder, Bahcc1. These results were recapitulated using conditional mutagenesis in intestinal organoids. The stem cell niche in the crypt includes ISCs in close association with Paneth cells. Loss of MLL1 from ISCs promoted transcriptional changes in Paneth cells involving metabolic and stress responses. Here we add ISCs to the MLL1 repertoire and observe that all known functions of MLL1 relate to the properties of somatic stem cells, thereby highlighting the suggestion that MLL1 is a master somatic stem cell regulator.

Background: Hepatocellular carcinoma (HCC) cells exhibit the stemness property, which makes the patient with HCC prone to tumor recurrence and metastasis. Despite the prominent regulatory role of long non-coding RNAs (lncRNAs) in tumor stemness, the roles and molecular mechanisms of LINC00106 in HCC are poorly understood.Methods: LINC00106, let7f and periostin expression levels in tissue specimens and cell lines were assessed through qRT-PCR and immunohistochemistry (IHC). Various in vivo and in vitro assays, namely sphere/colony formation, proportion of side population cells (SP%), invasion, migration, western blot, and murine xenograft model were employed for assessing the stemness and metastatic properties of HCC cells. Luciferase reporter assays, RNA-seq, RNA pull-down, RNA immunoprecipitation (RIP) were conducted to clarificate the target gene and analyze the underlying mechanisms.Results: LINC00106 was prominently upregulated in tissues and cell lines of HCC. Patients having a high LINC00106 level exhibited a poor outcome. Under in vivo and in vitro conditions, the stemness and metastatic properties of HCC cells were augmented by LINC00106. Additionally, LINC00106 was found to sponge let7f to upregulate periostin, which lead to the activation of periostin-associated PI3K-AKT signaling pathway. Moreover, m6A methylation was found to cause LINC00106 upregulation while maintaining LINC00106 RNA transcript stability.Conclusion: m6A methylation triggers the upregulation of LINC00106, which promotes the stemness and metastasis properties in HCC cells by sponging let7f, thereby resulting in periostin activation. The findings indicate the potential of LINC00106 as a diagnostic marker and therapeutic target for HCC.

Cloud radio access network(CRAN) is a new network architecture commonly used in 5G network.It uses network function virtualization and software defined network technology to support end-to-end network slicing so that access network can share the same infrastructure.A computing resource allocation scheme based on virtualized network function(VNF) computing resource demand forecasting was proposed for cloud wireless network supporting end-to-end network slicing.Data-driven operation and maintenance framework established by the control plane collects network information and performs data processing to predict the demand for computing traffic in a period of time,which used the discrete particle swarm optimization based on best-fit-decreasing to dynamically and dynamically allocate CRAN computing resources,reducing the migration energy consumption and migration times of VNF.

Mobile edge caching technology is gaining more and more attention because it can effectively improve the Quality of Experience (QoE) of users and reduce backhaul burden. This paper aims to improve the utility of mobile edge caching technology from the perspectie of caching resource management by examining a network composed of one operator, multiple users and Content Providers (CPs). The caching resource management model is constructed on the premise of fully considering the QoE of users and the servicing capability of the Base Station (BS). In order to create the best caching resource allocation scheme, the original problem is transformed into a multi-leader multi-follower Stackelberg game model through the analysis of the system model. The strategy combinations and the utility functions of players are analyzed. The existence and uniqueness of the Nash Equilibrium (NE) solution are also analyzed and proved. The optimal strategy combinations and the best responses are deduced in detail. Simulation results and analysis show that the proposed model and algorithm can achieve the optimal allocation of caching resource and improve the QoE of users. Keywords: Stackelberg game, Caching resource management, Quality of Experience, Mobile edge caching

As an important branch of the Internet of Things, the Internet of Multimedia Things (IoMT) has complex application scenarios, thus putting forward new challenges to data communication. With the application of compressed sensing (CS)-based image compression and transmission in the field of IoMT, the traditional CS image reconstruction algorithms have been extended to model-based algorithms, which exploit more prior information of multimedia objects other than sparsity/compressibility in the reconstruction process. However, these algorithms mainly exploit just one type of prior information, still leaving room for further improvement. In this paper, we propose a novel CS image reconstruction algorithm by jointly leveraging multi-scale (local and global) heterogeneous (statistical and structural) priors of natural images, named jointly leveraging statistical and structural priors for CS image reconstruction (JLSSP-CS), to enable high-quality CS image recovery for IoMT. Specifically, the proposed JLSSP-CS algorithm is realized under the iterative hard thresholding framework, and the reconstruction process is composed of two phases. In the first phase, the local statistical correction and the global statistical correction are considered sequentially. Then, the global statistical and structural priors are exploited in nested iterations to further refine the recovery result in the second phase. The extensive simulations have been conducted, and the results indicate that the proposed JLSSP-CS algorithm outperforms the current state of the art by realizing high-quality image reconstruction with a small number of measurements for IoMT end devices.

The Internet of Things (IoT) is a promising technology for the collection data among the seamless connectivity with massive physical devices for future 5G networks. While device-to-device (D2D) communication is an emerging technique, which potentially tends to promote the machine-type communications developments of the IoT. In this paper, we consider a wireless distributed storage network where the IoT devices cache decentralized data in each memory and use D2D links to share the whole content, and to save the bandwidth and energy consumptions compared to traditional base station cellular network. We analyze and compare the energy costs of regenerating codes and maximum distance separable (MDS) codes for data downloading and repairing processes with the different parameter configuration. We also define a target named D2D link availability to measure the download and repair efficiency, and obtain the optimal repair intervals of various schemes for the lowest energy cost. Furthermore, we propose a novel caching scheme, termed double replication MDS (DR-MDS), which can modify the repair bandwidth by utilizing more storage occupation, and improve the D2D link availability in the system. The simulation results have shown that the DR-MDS caching significantly outperformed the MDS caching in the energy saving, that also verifies the practicability and the feasibility of our D2D distributed caching system for the low-power IoT scenarios.

Novel successive cancellation list (SCL) decoding schemes of Polar codes by exploiting the error correction (EC) capability of the cyclic redundancy check (CRC) codes are proposed in this paper. Different from the schemes in the literature that only considered the error detection capability of CRC, the proposed schemes aim to improve the performance of CRC-aided Polar decoding to the most by benefiting from the potential EC capability of CRC. Specifically, we first propose a basic decoding scheme, named CRC error-correction-aided successive cancellation list (CRC-EC-SCL) decoding, by introducing the look-up-table-based CRC EC method into the Polar SCL decoding process. Then, based on the basic scheme, we further propose the segmented-CRC-EC-SCL decoding scheme. By segmented-CRC, the information block is divided into multiple segments and each segment is attached with a shorter CRC sequence. By conducting the CRC-EC-aided coding for each of the segments, multiple erroneous bits can be corrected early and error propagation can, thus, be efficiently suppressed. The simulation results show that both of the proposed decoding schemes have a significant performance gain over the classic CRC-EC-SCL decoding scheme. Especially for the segmented-CRC-EC-SCL, the performance gain at a frame error rate of 10−4 is about 0.4 dB. Moreover, the average computation complexity of the segmented-CRC-EC-SCL is close to the classic scheme.

In this paper, we focus on the millimeter-wave (mmWave) band multiple-input and multiple-output (MIMO) channel estimation in the satellite-based Internet of Things (S-IoT). At first, we establish a sparse geometric-based mmWave MIMO channel model between a high throughput satellite (HTS) and multiple terrestrial user equipments (UEs) for the S-IoT downlink system. By exploiting the sparsity inherent to the mmWave band channel, we propose an efficient adaptive random-selected multi-beamforming (ARM) estimation scheme, which can simultaneously estimate the mmWave MIMO channel state information (CSI) for multiple UEs in angle domain. The ARM estimation scheme measures of the CSI between the HTS and multiple UEs by utilizing a series of random combinations of transmitting beamforming vectors and receiving UEs' antennas and the required number of measurements can adaptively reduce as well as the signal-to-noise ratios (SNR) increases. To further improve the performance of ARM estimation scheme, the number of each beamforming been selected for the channel measurement is buffered, and modify the probability of the random selection of beams and UEs. Two improved ARM estimation schemes are proposed, one is ARM forcing adaptation beam selection (ARM-FABS) scheme, and the other is ARM partially estimated beam selection (ARM-PEBS) scheme. The simulation results show that the proposed ARM estimation schemes can reduce the required number of measurements and achieve a better tracking performance over a wide range of SNRs.

In this paper, we formulate a long-term resource allocation problem of non-orthogonal multiple access (NOMA) downlink system for the satellite-based Internet of Things (S-IoT) to achieve the optimal decoding order and power allocation. This long-term resource allocation problem of the satellite NOMA downlink system can be decomposed into two subproblems, i.e., a rate control subproblem and a power allocation subproblem. The latter is a non-convex problem and the solution of which relies on both queue state and channel state. However, the queue state and the channel state continually change from one time slot to another, which makes it extremely strenuous to characterize the optimal decoding order of successive interference cancellation (SIC). Therefore, we explore the weight relationship between the queue state and the channel state to derive an optimal decoding order by leveraging deep learning. The proposed deep learning-based long-term power allocation (DL-PA) scheme can efficiently derive a more accurate decoding order than the conventional solution. The simulation results show that the DL-PA scheme can improve the performance of the S-IoT NOMA downlink system, in terms of long-term network utility, average arriving rate, and queuing delay.

Benefiting from the extensive coverage, remote sensing satellites have been playing important roles in surveillance for regions on the earth surface. In order to accommodate with intermittent connected and partitioned characteristics of satellite topology, disruption-tolerant network (DTN) develops a feasible solution for networking among such satellites. However, utilized widely and frequently in the future, numerous image covering hundreds of spectral bands and kilometers width is supposed to be delivered simultaneously. Due to the timeliness constrain, efficient routing design with minimum delivery delay for bulk and concurrent image data has become the bottleneck of remote sensing application. Considering data transmission initiated as different tasks, therefore, the Task-driven Updated Discrete Graph (TUDG) is designed to depict the topology evolution, with task data and edge capacity model for BP/LTP incorporated Remote Sensing DTN Network (RS-DTNet). In particular, the multitask-based delivery delay analytical framework is proposed based on the TUDG graph model, by solving a mixed integer Max-Min optimization problem. The Multi-Task Minimum Delay Routing (MTMDR) is designed with the delay-optimal flow distribution, dispatching appropriate bundle data to edges in the TUDG. This flow-based routing avoids the path selection procedure, which may degenerate the delivery delay performance. Through numerical simulation based on the representative RS-DTNet scene, the proposed MTMDR routing strategy shows to advantage on delivery delay, compared with typical path-based routing.

Change detection determines and evaluates changes by comparing bi-temporal images, which is a challenging task in the remote-sensing field. To better exploit the high-level features, deep-learning-based change-detection methods have attracted researchers’ attention. Most deep-learning-based methods only explore the spatial–spectral features simultaneously. However, we assume the key spatial-change areas should be more important, and attention should be paid to the specific bands which can best reflect the changes. To achieve this goal, we propose the spatial–spectral joint attention network (SJAN). Compared with traditional methods, SJAN introduces the spatial–spectral attention mechanism to better explore the key changed areas and the key separable bands. To be more specific, a novel spatial-attention module is designed to extract the spatially key regions first. Secondly, the spectral-attention module is developed to adaptively focus on the separable bands of land-cover materials. Finally, a novel objective function is proposed to help the model to measure the similarity of learned spatial–spectral features from both spectrum amplitude and angle perspectives. The proposed SJAN is validated on three benchmark datasets. Comprehensive experiments have been conducted to demonstrate the effectiveness of the proposed SJAN.

Bacterial metabolites exhibit a variety of biologically active compounds including antibacterial and antifungal activities. It is well known that Bacillus is considered to be a promising source of bioactive secondary metabolites. Most plant pathogens have an incredible ability to mutate and acquire resistance, causing major economic losses in the agricultural field. Therefore, it is necessary to use the natural antibacterial compounds in microbes to control plant pathogens. This study was conducted to investigate the bio-active compounds of Bacillus megaterium L2. According to the activity guidance of Agrobacterium tumefaciens T-37, Erwinia carotovora EC-1 and Ralstonia solanacearum RS-2, five monomeric compounds, including erucamide (1), behenic acid (2), palmitic acid (3), phenylacetic acid (4), and β-sitosterol (5), were fractionated and purified from the crude ethyl acetate extract of B. megaterium. To our knowledge, all compounds were isolated from the bacterium for the first time. To understand the antimicrobial activity of these compounds, and their minimum inhibitory concentrations (MICs) (range: 0.98∼500 μg/mL) were determined by the broth microdilution method. For the three tested pathogens, palmitic acid exhibited almost no antibacterial activity (>500 μg/mL), while erucamide had moderate antibacterial activity (MIC = 500 μg/mL). Behenic acid showed MICs of 250 μg/mL against T-37 and RS-2 strains with an antibacterial activity. β-sitosterol showed significant antimicrobial activity against RS-2. β-sitosterol showed remarkable antimicrobial activity against RS-2 with an MIC of 15.6 μg/mL. In addition, with the antimicrobial activity, against T-37 (62.5 μg/mL) and against EC-1 (125 μg/mL) and RS-2 (15.6 μg/mL) strains notably, phenylacetic acid may be interesting for the prevention and control of phytopathogenic bacteria. Our findings suggest that isolated compounds such as behenic acid, β-sitosterol, and phenylacetic acid may be promising candidates for natural antimicrobial agents.

Due to the advantages of high transmission rate, lower power consumption, high security, etc., underwater wireless optical communication (UWOC) has been widely studied and considered as a potential technique for underwater communication. However, its performance is severely degraded by oceanic turbulence due to refractive index fluctuations, which is caused by the change of inhomogeneous ocean environment. Within our derived spatial power spectrum model under anisotropic oceanic turbulence, we conducted a detailed investigation for a spherical wave propagating in weak anisotropic turbulence in this paper. Based on the derived oceanic spectrum, we proposed a scintillation index model for spherical wave in anisotropic oceanic turbulence considering the aperture averaging effect at non-zero inner scale and limited outer scale. Besides, we analyze the aperture averaging scintillation index under the influence of channel parameters such as inner and outer scales. Simulation results reveal that the scintillation index increases with the increase of the outer scale, while the inner scale induces an opposite trend on the scintillation index. Moreover, the inner scale exhibits a larger impact than the outer scale on the UWOC system over weak oceanic turbulence.

Based on the concepts and related techniques of Internet of things (IoT),tracking the development tendency of the satellite IoT and LEO constellation communication system abroad,and the deployment of the integrated satellite-terrestrial information network in China,the concept of space Internet of things (Space IoT) with its framework and main characteristics was proposed.Space IoT has the different concept compared to the traditional IoT,not just using the relay satellite to implement remote machine-to-machine communication.Space IoT is a ubiquitous IoT system under the integrated satellite-terrestrial information network architecture,and an expansion of the terrestrial IoT in the global three-dimensional world,and a service and application platform of multiple information technologies.With the recently era of big data,the space IoT has to face some data storage and transmission problems,such as excessive system load,data loss,frequent link interruption,high energy consumption,etc.Establishing a space-oriented IoT integrated distributed storage and transmission system was to meet the requirements of security guarantee and cross-domain interconnection with massive information businesses.Development status of related technologies were illustrated.At last,the prospect and thought of the future research of space Internet of things were presented.

Recently, with the development of Ka-band high throughput satellites and hybrid satellite-terrestrial networks, distributed/virtual multiple-input multiple-output (MIMO) technology over satellites have attracted considerable research interest. In this paper, a novel performance analysis framework is proposed for MIMO with orthogonal space-time block coding under Licklider transmission protocol (LTP) for emerging hybrid satellite terrestrial networks, where we derive the closed-form expressions of the mean number of transmission rounds by using Laplace transform for reliable data delivery in automatic repeat request (ARQ) and hybrid-ARQ schemes. Furthermore, we obtain the throughput expressions and unit information energy for lossless- and truncated-(H)ARQ schemes, and the maximum throughput and minimum unit information energy value on information rate. We also investigate the LTP file delivery time over Rayleigh and Rician fading channels. Simulations results are provided to demonstrate the validity of our theoretical results and show the effect of antenna number on the system performance.

The integrated satellite-terrestrial network can provide broadband wireless access in a wide coverage, efficient, and cost-effective manner, and is regarded as one of the most promising infrastructures for future heterogeneous network toward fifth generation. With the development of next generation of high throughput satellites (HTS), the application of the millimeter-wave (mmWave) band HTS is viewed as a vital role in the future integrated satellite-terrestrial network. Considering the rain attenuation is the dominant fading factor of the mmWave channel, we first propose a practical time-varying rain attenuation prediction model based on the autoregressive-moving-average (ARMA) model. Then, we develop an adaptive coding transmission (ACT) scheme based on the analog fountain codes combine the ARMA mmWave channel prediction model. The key parameters are selected based on a tradeoff between the decoding failure probability, block length, and overhead for our ARMA-based ACT scheme. Simulation results show that our proposed ACT scheme can effectively improve the throughput.

Delay/disruption tolerant networking (DTN) was proposed as an internetworking architecture to accommodate the frequent and lengthy link disruptions and/or long propagation delays that are typical of a challenging communication environment. The challenging problems of reliable data delivery and effective mission control that are critical in space explorations are a typical application scenario of the DTN technology. Because space communications must integrate seamlessly with terrestrial communications to support efficient flight operations, DTN is designed as an overlay network architecture; as such, it innately supports the highly heterogeneous networks that will be built on 5G technology. In the absence of reliable underlying links, the reliable data delivery services of DTN rely heavily on the custody transfer feature of its core bundle protocol (BP). Little work has been done in theoretical analysis of the performance of BP custodial transfer in a space communication environment in presence of link disruptions. In this paper, we present a study of BP for reliable data delivery in space communications characterized by multiple link disruption events, accompanied by an extremely long propagation delay and data loss. An analytical model is built to estimate the bundle delivery time and transmission goodput performance of BP for bundle delivery over a space channel in the presence of multiple link disruptions. The model is validated by running data-flow experiments using a testbed infrastructure.

For inverse synthetic aperture radar imaging, high-quality and real-time performances are two essential indicators in many real applications. Due to the complex motion of the maneuvering target, the Doppler frequency is generally time varying. Consequently, it is difficult for most imaging algorithms to satisfy these two indicators simultaneously. The approaches based on the traditional range-Doppler (RD) algorithm can generally achieve rapid imaging but often encounter image blurring problems while the range-instantaneous-Doppler (RID) algorithms can generate high-quality images but at the cost of tremendous computational complexity. Aiming at this issue, we propose a new approach, termed power-weighting Fourier transform-based range-Doppler (PWFT-RD), to achieve a better comprehensive performance of the image quality and computational cost simultaneously. Specifically, we first build up the generalized signal model to describe the target motion with high-order dynamics. Second, we propose the PWFT which has the property of modulating expanded the signal spectrum into a keen-edged envelope. After that, we implement high-accuracy motion compensation (MOCOMP) by formulating the high-order parameter estimation as the least-squares problem and finally develop the PWFT-RD approach. Analysis and comparison experiments are designed to validate the effectiveness of our approach on employing PWFT for improving MOCOMP accuracy and enhancing the azimuth focus quality. In particular, the PWFT-RD approach shows much better real-time performance than RID algorithms thanks to its linear and blind processing attributes with quite low computational complexity.

An innovative scheme for concatenating the polar codes with the recently proposed spinal codes is presented in this paper. The primary objective is to improve the performance of the polar codes in the finite-length regime. One effective used way is to concatenate the polar codes with short outer codes. Essentially, the short outer codes that have as high performance as possible is required for concatenation. To this end, the newly invented spinal codes are used as the outer codes, which are characterized by its great error correcting capability even when the message length is short. First, the proposed codes, named spinal-polar, is implemented through an interleaved concatenation scheme. A joint iterative decoding algorithm is proposed accordingly, and the decoding complexity of the algorithm is also analyzed. Second, in order to reduce the decoding complexity of the full concatenation while maintaining the BER performance, the partial concatenation scheme is presented. Finally, we propose a rate allocation algorithm to further improve the BER performance of the designed concatenated codes. Extensive simulations results indicate that the proposed spinal-polar codes have significant performance improvement over the stand-alone polar codes, and the other improvement strategies mentioned earlier have also been proved to be effective.