Characterizing the tumor microenvironment at the single-cell level reveals a novel immune evasion mechanism in osteosarcoma

The immune microenvironment extensively participates in tumorigenesis as well as progression in osteosarcoma(OS).However,the landscape and dynamics of immune cells in OS are poorly characterized.By analyzing single-cell RNA sequencing(sc RNA-seq)data,which characterize the transcription state at single-cell resolution,we produced an atlas of the immune microenvironment in OS.The results suggested that a cluster of regulatory dendritic cells(DCs)might shape the immunosuppressive microenvironment in OS by recruiting regulatory T cells.We also found that major histocompatibility complex class I(MHC-I)molecules were downregulated in cancer cells.The findings indicated a reduction in tumor immunogenicity in OS,which can be a potential mechanism of tumor immune escape.Of note,CD24 was identified as a novel“don’t eat me”signal that contributed to the immune evasion of OS cells.Altogether,our findings provide insights into the immune landscape of OS,suggesting that myeloid-targeted immunotherapy could be a promising approach to treat OS.

A rescaling algorithm for multi-relaxation-time lattice Boltzmann method towards turbulent flows with complex configurations

Understanding and modeling flows over porous layers are of great industrial significance.To accurately solve the turbulent multi-scale flows on complex configurations,a rescaling algorithm designed for turbulent flows with the Chapman-Enskog analysis is proposed.The mesh layout and the detailed rescaling procedure are also introduced.Direct numerical simulations(DNSs)for a turbulent channel flow and a porous walled turbulent channel flow are performed with the three-dimensional nineteen-velocity(D3Q19)multiple-relaxation-time(MRT)lattice Boltzmann method(LBM)to validate the accuracy,adaptability,and computational performance of the present rescaling algorithm.The results,which are consistent with the previous DNS studies based on the finite difference method and the LBM,demonstrate that the present method can maintain the continuity of the macro values across the grid interface and is able to adapt to complex geometries.The reasonable time consumption of the rescaling procedure shows that the present method can accurately calculate various turbulent flows with multi-scale and complex configurations while maintaining high computational efficiency.

骨水泥型人工双极股骨头置换治疗股骨近段骨转移瘤

目的:探讨骨水泥型人工双极股骨头置换治疗股骨近段转移瘤的临床疗效。方法:回顾性分析2012年1月至2019年6月华中科技大学同济医学院附属协和医院收治的54例行骨水泥型人工双极股骨头置换的股骨近段转移瘤患者的资料。采用疼痛视觉模拟评分(visual analogue scale,VAS)、国际骨肿瘤协会(musculoskeletal tumor society system,MSTS)功能评分、国际保肢学会(international society of limb salvage,ISOLS)影像评分、Harris髋关节功能评分量表(Harris hip score)、Karnofsky功能状态(Karnofsky performance status,KPS)评分和诺丁汉健康调查问卷(Nottingham health profile,NHP)评分评定患者疼痛、肢体功能和生存质量。Kaplan-Meier法分析生存情况。结果:患者随访时间为10~99个月,平均42.17个月。患者手术时间(79.68±6.17)min,术中出血量(524.00±39.25)mL。术后3、6和12个月,VAS评分和NHP评分分别较术前降低,MSTS评分、ISOLS评分、Harris评分和KPS评分分别较术前提高,差异均具有统计学意义(P<0.05)。术后3、6和12个月,每个随访点之间的VAS评分、相关功能评分和生存质量评分差异均无统计学意义(P>0.05)。随访期内6例发生并发症。患者平均生存时间19.46个月,6个月、1年和3年生存率分别为88.89%、70.37%和11.11%。结论:股骨近段骨转移瘤患者行骨水泥型人工双极股骨头置换可减轻患者疼痛,提高肢体功能,延长生存时间,提高生存质量。

Adaptive coherence estimator based on the Krylov subspace technique for airborne radar

A novel adaptive detector for airborne radar space-time adaptive detection （STAD） in partially homogeneous environments is proposed. The novel detector combines the numerically stable Krylov subspace technique and diagonal loading technique, and it uses the framework of the adaptive coherence estimator （ACE）. It can effectively detect a target with low sample support. Compared with its natural competitors, the novel detector has higher proba- bility of detection （PD）, especially when the number of the training data is low. Moreover, it is shown to be practically constant false alarm rate （CFAR）.

Increasing rainfed wheat yield by optimizing agronomic practices to consume more subsoil water in the Loess Plateau

Erratic rainfall and misalignment between the rainy season and the growing season of winter wheat greatly limit rainfed winter wheat yield in the Loess Plateau of China. To increase the grain yield of winter wheat in this region, the effects of different agronomic practices, including adjusting planting pattern(NR, narrow row spacing), increasing seeding rate(high seeding rate, HS), decreasing basal nitrogen rate and increasing top-dressed nitrogen rate(DBN), and replacing an old cultivar with a new cultivar(NC) on wheat yield were investigated for two consecutive years. The results showed that the current grain yield of rainfed winter wheat in the Loess Plateau could be increased to 5879–7093 kg ha^(-1) by HS, DBN and NC practices relative to the practice of high-yielding farmers(PF). The increased yield due to HS, DBN and NC was attributed to the higher number of spikes ha^(-1), 1000-grain weight, and kernels spike^(-1). Before the flowering stage, HS increased soil water consumption(SWC) in 1–3 m subsoil due to the higher plant population compared with that of PF, whereas DBN decreased SWC in the 0–2 m soil layer compared with that of PF. After the flowering stage, HS, DBN, and NC increased SWC by 8–16 mm in 2–3 m subsoil compared to PF. The water use efficiency(WUE) was increased under DBN and NC in comparison with PF.However, the WUE did not increase under HS as it had the highest evapotranspiration among the five treatments. Increasing the use of subsoil water during the late growth stage by optimizing agronomic practices or applying new cultivars with expansive roots should be the primary approach to increase rainfed winter wheat yield in this region.

Adaptive detection based on orthogonal partition of the primary and secondary data

A novel adaptive detection scheme both for point-like and distributed targets in the presence of Gaussian disturbance in the partial y homogeneous environment （PHE） is proposed. The novel detection scheme is based on the orthogonal projection technique. Both the case of known covariance matrix structure and the case of unknown covariance matrix structure are con-sidered. For the former case, the closed-form statistical pro-perty of the novel detectors is derived. When the covariance matrix is unknown, the corresponding detectors have higher probabilities of detection （PDs） than their natural competitors. Moreover, they ensure constant false alarm rate （CFAR） property.

Adaptive detection in the presence of signal mismatch

The problem of adaptive detection in the situation of signal mismatch is considered; that is, the actual signal steering vector is not aligned with the nominal one. Two novel tunable detectors are proposed. They can control the degree to which the mismatched signals are rejected. Remarkably, it is found that they both cover existing famous detectors as their special cases. More importantly, they possess the constant false alarm rate（CFAR）property and achieve enhanced mismatched signal rejection or improved robustness than their natural competitors. Besides, they can provide slightly better matched signals detection performance than the existing detectors.

A robust joint frequency spectrum and power allocation strategy in a coexisting radar and communication system

The resource allocation technique is of great significance in achieving frequency spectrum coexistence in Joint Radar-Communication(JRC) systems, by which the problem of radio frequency spectrum congestion can be well alleviated. A Robust Joint Frequency Spectrum and Power Allocation(RJFSPA) strategy is proposed for the Coexisting Radar and Communication(CRC)system. Specifically, we consider the uncertainty of target Radar Cross Section(RCS) and communication channel gain to formulate a bi-objective optimization model. The joint probabilities that the Cramér-Rao Lower Bound(CRLB) of each target satisfying the localization accuracy threshold and the Communication Data Ratio(CDR) of each user satisfying the communication threshold are simultaneously maximized, under the constraint of the total power budget. A Three-Stage Alternating Optimization Method(TSAOM) is proposed to obtain the Best-Known Pareto Subset(BKPS) of this problem, where the frequency spectrum, radar power, and communicator power are allocated using the greedy search and standard convex optimization methods, respectively. Simulation results confirm the effectiveness of the proposed RJFSPA strategy, compared with the resource allocation methods in a uniform manner and that ignores the uncertainties. The efficiency of the TSAOM is also verified by the comparison with the exhaustive search-based method.

Fabrication of Bio-inspired Superamphiphobic Aluminum Alloy Surface with Oil-triggered Wenzel-Slippery Transition via Femtosecond Laser

Surface-tension-confined microfluidic devices are platforms for manipulating 2D droplets based on patterned surfaces with special wettability.They have great potential for various applications,but are still in the early stages of development and face some challenges that need to be addressed.This study,inspired by the Wenzel and slippery transition of rose petal,develops a Patterned Oil-triggered Wenzel-slippery Surface(POWS)to examine the microfluidic devices.A laser-chemical composite method is established to fabricate POWSs,which take rose-petal-like microstructures as wettability pattern and a superamphiphobic surface as the background.The prepared POWSs switched between high adhesion superhydrophobic state and the slippery liquid-infused surface state through adding or removing the lubricant oil.In the high adhesion superhydrophobic state,the droplets can be sticked on the surface.In the slippery liquid-infused state,the droplet can slide along the wettability pattern as the designed route.A POWS-based droplet reactor is further constructed,on which,the droplets can be remotely controlled to move,mix and react,as required.Such a POWS,which manipulates droplets with surface tension controlled by the switchable wettability patterns,would be a promising candidate to construct multiple surface-tension-confined microfluidic devices.In addition,the fabrication technique and design principle proposed here may aid the development of various field related to the bio-inspired surfaces,such as water collection,desalination and high throughput analysis,etc.

Traumatic brain injury stimulates sympathetic tone-mediated bone marrow myelopoiesis to favor fracture healing

Traumatic brain injury(TBI)accelerates fracture healing,but the underlying mechanism remains largely unknown.Accumulating evidence indicates that the central nervous system(CNS)plays a pivotal role in regulating immune system and skeletal homeostasis.However,the impact of CNS injury on hematopoiesis commitment was overlooked.Here,we found that the dramatically elevated sympathetic tone accompanied with TBI-accelerated fracture healing;chemical sympathectomy blocks TBIinduced fracture healing.TBI-induced hypersensitivity of adrenergic signaling promotes the proliferation of bone marrow hematopoietic stem cells(HSCs)and swiftly skews HSCs toward anti-inflammation myeloid cells within 14 days,which favor fracture healing.Knockout ofβ3-orβ2-adrenergic receptor(AR)eliminate TBI-mediated anti-inflammation macrophage expansion and TBIaccelerated fracture healing.RNA sequencing of bone marrow cells revealed that Adrb2 and Adrb3 maintain proliferation and commitment of immune cells.Importantly,flow cytometry confirmed that deletion ofβ2-AR inhibits M2 polarization of macrophages at 7th day and 14th day;and TBI-induced HSCs proliferation was impaired inβ3-AR knockout mice.Moreover,β3-andβ2-AR agonists synergistically promote infiltration of M2 macrophages in callus and accelerate bone healing process.Thus,we conclude that TBI accelerates bone formation during early stage of fracture healing process by shaping the anti-inflammation environment in the bone marrow.These results implicate that the adrenergic signals could serve as potential targets for fracture management.

Beam resource scheduling for a VHF-MIMO radar network in low-angle tracking

The low-angle tracking in multipath interference is a challenging problem for the Very High Frequency(VHF)radar.The colocated Multi-Input Multi-Output(MIMO)technique can remedy such a defect.In this paper,a Joint Beam-Target Assignment and Power Allocation(JBTAPA)strategy is proposed for the VHF-MIMO radar network tracking low-angle targets.The core of the JBTAPA strategy is to improve the worst tracking accuracy among multiple targets by assigning appropriate beams to targets and allocating the power resource in each beam using the feedback information in the tracking cycle.Taking into account the transmit multipath and receive multipath,we derive the Cramer-Rao Lower Bound(CRLB)on angle estimate,which is then incor-porated in the Predicted Conditional CRLB(PC-CRLB).A more accurate and consistent lower bound is provided as the optimization metric since the PC-CRLB is based on the most recently real-ized measurements.A two-stage-based technique is proposed to solve the JBTAPA problem,which is originally NP-hard.Simulation results verify the effectiveness and efficiency of the proposed method.The results also imply that the target reflectivity plays one of the important roles in resource allocation.

Resource saving based dwell time allocation and detection threshold optimization in an asynchronous distributed phased array radar network

The resource optimization plays an important role in an asynchronous Phased Array Radar Network(PARN)tracking multiple targets with Measurement Origin Uncertainty(MOU),i.e.,considering the false alarms and missed detections.A Joint Dwell Time Allocation and Detection Threshold Optimization(JDTADTO)strategy is proposed for resource saving in this case.The Predicted Conditional Cramér-Rao Lower Bound(PC-CRLB)with Bayesian Detector and Amplitude Information(BD-AI)is derived and adopted as the tracking performance metric.The optimization model is formulated as minimizing the difference between the PC-CRLBs and the tracking precision thresholds under the constraints of upper and lower bounds of dwell time and false alarm ratio.It is shown that the objective function is nonconvex due to the Information Reduction Factor(IRF)brought by the MOU.A cyclic minimizer-based solution is proposed for problem solving.Simulation results confirm the flexibility and robustness of the JDTADTO strategy in both sufficient and insufficient resource scenarios.The results also reveal the effectiveness of the proposed strategy compared with the strategies adopting the BD without detection threshold optimization and amplitude information.

Enhanced activation of persulfate using mesoporous silica spheres augmented Cu–Al bimetallic oxide particles for bisphenol A degradation

Herein,Cu–Al bimetallic oxide was synthesized and mixed with mesoporous silica spheres via a simple hydrothermal method.The prepared sample was then analyzed and employed to activate potassium peroxydisulfate for bisphenol A removal.Based on the results of X-ray diffraction,scanning electron microscopy,and energy dispersion spectroscopy,Cu–Al bimetallic oxide was determined as CuO-Al2O3,and mesoporous silica spheres were found around the these particles.At 30 min,a bisphenol A degradation level of 90%was achieved,and it remained at over 60%after five consecutive cycles,indicating the catalyst’s superior capacity and stability.In terms of removal performance,the radical pathway(including■OH•,and■)and singlet oxygen(■)bisphenol A,potassium peroxydisulfate,and the catalyst played a dominant role.The introduction of Al2O3 promoted the formation of surface oxygen vacancies,which improved ligand complex formation between potassium peroxydisulfate and the catalyst,thereby facilitating electron migration.Furthermore,mesoporous silica spheres augment not only enhanced bisphenol A adsorption but also alleviated Cu leaching.Overall,this work is expected to provide significant support for the rational development of catalysts with high catalytic activity for persulfate activation via surface electron migration.

一种基于稀疏重构的主瓣拖曳式干扰抑制方法

提出了一种基于稀疏重构的主瓣拖曳式干扰抑制方法,可在干扰环境下有效提取目标的距离和空间角度信息.新方法首先利用正交匹配追踪算法估计主瓣拖曳式干扰的角度、幅度和相位,进而重构干扰数据;再利用接收数据减去干扰重构数据,大幅削弱主瓣拖曳式干扰的能量;然后利用稀疏Bayes算法来估计剩余干扰和目标的角度–距离信息;最后结合稀疏恢复结果,并根据目标在某一空间角度上仅占有2~3个距离单元,而剩余的干扰占满所有距离单元这一先验知识,可容易鉴别目标和干扰,进而提取目标参数.

Numerical simulation and experiment of grain motion in the conveying system of ratooning rice harvesting machine

The mixtures,grains,and residues in the ratooning rice harvesting machine need to be conveyed forward,backward,upward,and downward.Due to such operations,often accumulation and blockage take place at the intersection of a horizontal-vertical screw conveyor,resulting in low efficiency,high power consumption,and even grain damage.In this study,a CFD-DEM approach was applied to address the above problems.Firstly,a pneumatic conveying device was designed for ratooning rice,and then the motion of the rice grains and airflow field was analyzed in detail.The effects of different cross-sectional heights and lengths of the contraction section related to the mixing cavity were examined.Finally,the three-factor quadratic regression orthogonal rotational combination method was adopted in the experiment,and the fan velocity,filling coefficient,and speed of the horizontal screw conveyor were taken as test factors.The results showed that with the increasing cross-sectional height of the contraction section in the mixing cavity,the grain velocity decreased and the dispersity increased.With increasing length of the contraction section in the mixing cavity,the area of the high-speed airflow zone increased and the diffusion effect was enhanced.At the fan velocity of 2700 r/min,the filling coefficient was 0.41,the speed of the horizontal screw conveyor was 1173 r/min,and the outlet flow optimization index was the highest,which was 45.9%higher than that obtained without airflow.

Accelerated antibacterial red-carbon dots with photodynamic therapy against multidrug-resistant Acinetobacter baumannii

The emergence of antibiotic resistance in bacteria is a major public-health issue.Synthesis of efficient antibiotic-free material is very important for fighting bacterial infection-related diseases.Herein,red-carbon dots(R-CDs)with a broad range of spectral absorption(350–700 nm)from organic bactericides or intermediates were synthesized through a solvothermal route.The prepared R-CDs not only had intrinsic antibacterial activities,but also could kill multidrug-resistant bacteria(multidrug-resistant Acinetobacter baumannii(MRAB)and multidrug-resistant Staphylococcus aureus(MRSA))effectively by generating reactive oxygen species.Furthermore,R-CDs could eliminate and inhibit the formation of MRAB biofilms,while conferring few side effects on normal cells.A unique property of R-CDs was demonstrated upon in vivo treatment of antibiotic-sensitive MRABinduced infected wounds.These data suggested that this novel R-CDs-based strategy might enable the design of nextgeneration agents to fight drug-resistant bacteria.

Air pollution and inhalation exposure to particulate matter of different sizes in rural households using improved stoves in central China

Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter（PM） emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China.Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4 ± 41.1, 159.3 ± 74.3, 176.7 ± 78.1 and 217.9 ± 78.1 μg/m3,respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25 μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure.

Polycyclic aromatic hydrocarbons in ambient air,surface soil and wheat grain near a large steel-smelting manufacturer in northern China

The total concentrations and component profiles of polycyclic aromatic hydrocarbons（PAHs） in ambient air,surface soil and wheat grain collected from wheat fields near a large steel-smelting manufacturer in Northern China were determined.Based on the specific isomeric ratios of paired species in ambient air,principle component analysis and multivariate linear regression,the main emission source of local PAHs was identified as a mixture of industrial and domestic coal combustion,biomass burning and traffic exhaust.The total organic carbon（TOC） fraction was considerably correlated with the total and individual PAH concentrations in surface soil.The total concentrations of PAHs in wheat grain were relatively low,with dominant low molecular weight constituents,and the compositional profile was more similar to that in ambient air than in topsoil.Combined with more significant results from partial correlation and linear regression models,the contribution from air PAHs to grain PAHs may be greater than that from soil PAHs.