A quad-mode dual-band dual-sense circularly polarized (CP) single patch antenna is proposed. The four boresight radiating modes are obtained by simply loading a stub and U-slot on the patch. The ...characteristic mode analysis (CMA) is utilized to reveal the operational principles of the patch. The control over the antenna's frequency ratio and the sense of circular polarization is achieved by independently manipulating the different modes. This is accomplished by altering the dimensions of the patch, U-slot, and the stub. To further validate the effectiveness of the proposed design method, a patch antenna prototype has been designed and fabricated for experimental validation. In both bands, left-hand circular polarization and right-hand circular polarization were obtained separately. The measured impedance bandwidths in the low and high bands are 12.7% and 13%, respectively, corresponding to a 3 dB axial ratio (AR) bandwidths of 2.47% (3.2-3.28 GHz) and 1.17% (4.26-4.31 GHz).
Yan’an new district (YND) is one of the largest civil engineering projects for land creation in Loess Plateau, of which the amount of earthwork exceeds 600 million m3, to create 78.5 km2 of flat ...land. Such mega-scale engineering activities and complex geological characteristics have induced wide land deformation in the region. Small baseline subset synthetic aperture radar interferometry (SBAS-InSAR) method and 55 Sentinel-1A (S-1A) images were utilized in the present work to investigate the urban surface deformation in the Yan’an urban area and Yan’an new airport (YNA) from 2015 to 2019. The results were validated by the ground leveling measurements in the YNA. It is found that significant uneven surface deformation existed in both YND and YNA areas with maximum accumulative subsidence of 300 and 217 mm, respectively. Moreover, the average subsidence rate of the YND and YNA areas ranged from −70 to 30 mm/year and −50 to 25 mm/year, respectively. The present work shows that the land deformation suffered two periods (from 2015 to 2017 and from 2017 to 2019) and expanded from urban center to surrounding resettlement area, which are highly relevant with urban earthwork process. It is found that more than 60% of land subsidence occurs at filled areas, while more than 65% of surface uplifting occurs at excavation areas. The present work shows that the subsidence originates from the earth filling and the load of urban buildings, while the release of stress is the major factor for the land uplift. Moreover, it is found that the collapsibility of loess and concentrated precipitation deteriorates the degree of local land subsidence. The deformation discovered by this paper shows that the city may suffer a long period of subsidence, and huge challenges may exist in the period of urban maintaining buildings and infrastructure facilities.
Shared leadership is lauded to be a performance-enhancing approach with applications in many management domains. It is conceptualized as a dynamic team process as it evolves over time. However, it is ...surprising to find that there are no studies that have examined its temporally relevant boundary conditions for the effectiveness of the team. Contributing to an advanced understanding of the mechanism of shared leadership in engineering design teams, this research aims to investigate
shared leadership is positively related to team effectiveness and
shared leadership is more likely to be effective. Using a field sample of 119 individuals in 26 engineering design teams from China and the technique of social network analysis, we found that, consistent with cognate studies, shared leadership is positively related to team effectiveness when measured in terms of team task performance and team viability. Moreover, by integrating the project life cycle as a moderator, this study is among the first to investigate the temporal factors, for the effectiveness of shared leadership. The result shows that the stage of the project life cycle moderates the positive shared leadership-team effectiveness relationship, such that this association is stronger at the early phase than at the later phase of the project. Overall, these findings offer insightful thoughts to scholars in the field of shared leadership and bring practical suggestions for project managers in business who seek to implement best practice in organizations toward high team effectiveness.
Extracellular vesicles (EVs) have emerged as promising tumor biomarkers for early cancer diagnosis, as primary tumor-secreted EVs carry characteristic molecular information on parent cells. It is ...thus desirable to realize the efficient discrimination of the signatured EVs-associated microRNAs (miRNAs) with low expression and subtle variation. Here, we introduce an autonomous nonlinear enzyme-free signal amplification paradigm for EVs discrimination through a highly sensitive and selective detection of their inherent miRNAs in situ. Our proposed amplifier consists of a modularized DNAzyme-amplified two-stage cascaded hybridization chain reaction (CHCR–DNAzyme) circuit, where the analyte-generated output of the preceding hybridization chain reaction (HCR1) stage serves as input to motivate the following hybridization chain reaction (HCR2) stage and the concomitant assembly of numerous DNAzyme biocatalysts. By incorporating a flexibly configurable sensing module, this modular CHCR–DNAzyme circuit can further extend to “plug-and-play” sensing mode that enables the miRNA assay with high specificity. The sophisticated design and the detecting performance of our CHCR–DNAzyme scheme were systematically investigated in vitro. The optimized CHCR–DNAzyme system was further applied for distinguishing EVs derived from different cells through the amplified detection of a putative miRNA biomarker in EVs. This compact CHCR–DNAzyme amplifier provides a universal and facile toolbox for highly efficient identification of multiple miRNAs-involved EVs and thus holds great potential for early cancer diagnosis.
Biomolecular self-assembly circuits have been well developed for high-performance biosensing and bioengineering applications. Here we designed an isothermal concatenated nucleic acid amplification ...system which is composed of a lead-in catalyzed hairpin assembly (CHA), intermediate hybridization chain reaction (HCR) and ultimate DNAzyme amplifier units. The analyte initiates the self-assembly of hairpin reactants into dsDNA products in CHA, which generates numerous trigger sequences for activating the subsequent HCR-assembled long tandem DNAzyme nanowires. The as-acquired DNAzyme catalyzed the successive cleavage of its substrates, leading to an amplified fluorescence readout. The sophisticated design of our CHA-HCR-DNAzyme scheme was systematically investigated
in vitro
and showed dramatically enhanced detection performance. As a general sensing strategy, this CHA-HCR-DNAzyme method enables the amplified analysis of miRNA and its accurate intracellular imaging in living cells, originating from their synergistic signal amplifications. This method shows great potential for analyzing trace amounts of biomarkers in various clinical research studies.
A rationally and modularly engineered CHA-HCR-DNAzyme circuit was constructed for amplified biosensing and bioimaging with high performance.
Tebuconazole is a widely used fungicide that has been detected in water ecosystems, of which the concentrations may affect the endocrine function of aquatic organisms. At present study, ...tissue-specific bioaccumulation of tebuconazole was found in ovary of adult zebrafish, indicating a potential risk of endocrine disruption. In order to evaluate the potential endocrine disrupting effects, three life stages (2 hpf (hours post-fertilization) −60 dpf (days post-fertilization), Stage I; 60–120 dpf, Stage II; 180–208 dpf, Stage III) of zebrafish (Danio rerio) were chronically exposed to tebuconazole at the concentrations ranging from 0.05 mg/L to 1.84 mg/L. Result showed that exposed to tebuconazole could lead to a male-biased sex differentiation in juvenile zebrafish and significant decrease of the percentage of germ cells in sexually-mature zebrafish. Egg production was significantly inhibited by 57.8% and 19.2% after Stage II- and Stage III-exposures, respectively. The contents of 17β-estradiol in gonad decreased by 63.5% when exposed to 0.20 mg/L tebuconazole at Stage II and by 49.5% after exposed to 0.18 mg/L tebuconazole at Stage III, respectively. For all stages exposure, reductions in 17β-estradiol/testosterone ratio were observed, indicating an imbalance in steroids synthesis. Additionally, tebuconazole reduced the expression of cyp19a, which was consistent with the decrease of E2 level. In overall, the present findings indicated that, playing as an anti-estrogen-like chemical, tebuconazole inhibited the expression of Cyp19, thereby impairing steroid hormones biosynthesis, leading to a diminished fecundity of zebrafish.
Display omitted
•Tebuconazole plays as an anti-estrogen endocrine disrupting effects on zebrafish.•Tebuconazole induces a male-biased gonadal differentiation in juvenile zebrafish.•Tebuconazole delays development of germ cells in puberty and adult zebrafish.•Block of E2 pathway may be the disrupting mechanism caused by tebuconazole.
Tebuconazole blocks E2 pathway, thereby leading to a male-biased differentiation in juvenile zebrafish and delaying germ cells development in puberty and adult zebrafish, playing an antiestrogen-like role.
•The technique of process mining is presented to discover bottlenecks and position deviations of gas explosion accident emergency rescue processes in underground coal mines.•The feasibility and ...advantage of extracting emergency rescue process model for GEAs from historical events log is validated and the emergency rescue process is characterized in the meantime.•The average length of cases is 23.72 events, 60% of the cases are below the average length, and 40% of the cases exceed the average length.•Considerable GEAs consume more time for emergency rescue compared with major GEAs, emergency rescue of GEAs in north part of China consumes more time compared with south part of China, the accident site of heading face is slightly higher than coal face in emergency rescue time, the emergency rescue duration is least affected by coal mine ownership; compared with case length, the factors of accident grade, coal mine region and accident site possess greater influence on case duration.•56% of the cases take less than two days, 38% of the cases take less than one day, 16% of the cases take less than half a day, while 14% of the cases take more than 10 days.•The resources of emergency rescue headquarters, barmaster and medical staff share a better centrality in GEA emergency rescue processes.
Gas explosion has always been one of the major accident types in the coal mines of China, and reliable emergency rescue process is one of the key guarantees to minimize accident losses. As an emerging discipline to discover bottlenecks and position deviations of processes, process mining is widely used to improve various business processes in recent years. Nevertheless, scarcely does any research apply it to the field of coal mine emergency rescue to our knowledge. In this study, we apply the technique of process mining to domain of gas explosion accident emergency rescue in coal mines. 50 considerable and major gas explosion accidents, which occurred from the second half of 2006–2014 in Chinese coal mines, are selected as log data. The aspects of control-flow perspective, case perspective, helicopter view, organizational dimension and performance perspective are analyzed by process mining. In terms of control-flow perspective, the emergency rescue model is extracted by the inductive miner in ProM, correspondingly, conformance checking and comparison with real-life model have shown the validity of our work. Research also shows that the average length of cases is 23.72 events, and 60% of the cases are under the average length; 56% of the gas explosion accident emergency rescue processes last less than two days; emergency rescue headquarters, barmaster and medical staff share the highest centrality in social network of rescue; the rescue performance is more affected by accident grade, compared with the factors of accident site, region of coal mine and coal mine ownership.
DNAzyme‐based gene therapy holds immense prospects for effectively treating severe diseases, yet is constrained with inefficient delivery and unconditional activation. Herein, we designed a ...bioinspired self‐catabolic DNA nanocapsule for sustaining tumor‐specific cascade activation of therapeutic DNAzyme. The exquisite DNAzyme was temporarily masked by the self‐excising DNAzyme in the hierarchical rolling circle replication (RCR) nanostructures, thus stayed in an inactive state in physiological fluids. Through the multivalent tumor‐anchoring aptamer strands, the RCR nanocapsule was specifically accumulated in cancer cells and was sequentially activated for motivating the ultimate DNAzyme‐mediated gene silencing via the intelligent stimuli‐responsive cascade DNAzyme activation. By virtue of the programmable RCR assembly strategy, our compact DNAzyme nanoplatform shows great promise for developing versatile smart gene therapeutics and personalized nanomedicines.
An exquisite cascade DNAzyme‐sustained gene silencing platform was assembled to program the “mask‐cleave‐release” of therapeutic DNAzyme from the intelligent DNAzyme nanosponge, where the upstream self‐catabolic DNAzyme mediated the specific and accurate activation of downstream therapeutic DNAzyme for guaranteeing the efficient gene silencing with improved bioavailability.
In this work, a novel approach that can calibrate the colors obtained with a cellphone camera was proposed for the colorimetric sensor array. The variations of ambient light conditions, imaging ...positions and even cellphone brands could all be compensated via taking the black and white backgrounds of the sensor array as references, thereby yielding accurate measurements. The proposed calibration approach was successfully applied to the detection of glucose in urine by a colorimetric sensor array. Snapshots of the glucose sensor array by a cellphone camera were calibrated by the proposed compensation method and the urine samples at different glucose concentrations were well discriminated with no confusion after a hierarchical clustering analysis.
Display omitted
•The glucose in urine was detected using a colorimetric sensor array.•A calibration approach for cellphone camera imaging was proposed.•Snapshots of the glucose sensor array by a cellphone camera were calibrated.•Glucose concentrations were well discriminated with no confusion.
The responses of microbial communities in hyporheic zone to the eco-hydrological process have been a hotspot in river ecological health research. However, the impact of different metal pollution ...levels and hyporheic exchange on the microbial communities are still unclear. In this study, we further explored the effects of different degrees of heavy metals pollution and the strength of hyporheic exchange on the structures and functions of microbial community in hyporheic zone sediment ecosystem. Sediments were collected from the Weihe River to determine the concentrations of heavy metals, grain size distribution, and hydraulic conductivity, and the microbial information were obtained by eDNA technology. The comprehensive pollution status of the study area was at the slight and moderate level. The hydraulic conductivity (Kv) varied between 0.20 and 3.65 (m/d). The microbial community structures had complex temporal and spatial heterogeneity. The microbial molecular ecological network had modular characteristics and significant differences in different periods (p < 0.05). Metabolic functional genes in microbial communities had the highest relative abundance. In particular, there is a significant negative correlation between heavy metals and microorganisms (p < 0.05), with Cu and Zn contributing the most to microbial community changes (p < 0.05). Moreover, grain size had a significant impact on microorganisms, heavy metals and grain size significantly affect the predictive functions of microbial communities. Our in-depth research on microorganisms in the hyporheic zone provides references for monitoring and bioremediation of aquatic ecosystems.
•Heavy metals and grain size had significant effects on functions of microorganisms.•Heavy metal pollutants in hyporheic zone will pose certain ecological risks.•Microbial community structure and hydraulic conductivity had seasonal fluctuation.•Cu and Zn contributed the most to variations of microbial communities.•Ni, Cu, Zn and Pb had negative effects on the abundance of certain microbial taxa.
PDF
