Search

Abstract Synthesizing high-crystalline covalent organic framework films is highly desired to advance their applications in two-dimensional optoelectronics, but it remains a great challenge. Here, we report a diffusion-limited synthesis strategy for wafer-scale uniform covalent organic framework films, in which pre-deposited 4,4′,4″,4‴-(1,3,6,8-Tetrakis(4-aminophenyl) pyrene is encapsulated on substrate surface with a layer of covalent organic framework prepolymer. The polymer not only prevents the dissolution of precursor, but limits the reaction with terephthalaldehyde dissolved in solution, thereby regulating the polymerization process. The size depends on growth substrates, and 4-inch films have been synthesized on silicon chips. Their structure, thickness, patterning and crystallization degree can be controlled by adjusting building blocks and polymerization chemistries, and molybdenum disulfide have been used as substrates to construct vertical heterostructure. The measurements reveal that using covalent organic framework as a photosensitive layer, the heterojunction displays enhanced photoelectric performance, which can be used to simulate the adaptative function of visual system.

The Mg–8Li dual phase alloy was deformed by multi-directional compression with different passes. Microstructure evolution of deformed Mg–8Li alloy was analyzed by electron backscatter diffraction. X-ray diffraction profile was used to calculate the dislocation density in α-Mg and β-Li phase to reveal the quantitively change trend under different compression passes. The mechanical properties were assessed through tensile and compressive tests. The Mg–8Li alloy exhibited optimal mechanical properties when compressed with 12 passes (sample 12MDC), with a compression yield strength of 183.1 MPa and a tensile yield strength of 124.2 MPa. The improved mechanical properties in sample 12MDC were attributed to an increase in {10 1‾ 2} twin and {101‾ 3}-{101‾ 2} double twin boundaries, along with the presence of sub-grain boundaries and a reduced grain size in the α-Mg phase. Additionally, the inconsistent results between microhardness and dislocation density calculation manifests the uneven distribution of dislocations in β-Li phase. Broken α-Mg phase brings more phase interface to relieve the strain in β-Li phase, which results to a decreased dislocation density in sample 12MDC (1.19 × 1011/m2). Results show that weaken tension-compression yield asymmetry and more even distribution of dislocation in both phases could be achieved when the compression passes increases to 12.

Abstract Dynamin-related protein 1 (Drp1) is a crucial regulator of mitochondrial dynamics, the overactivation of which can lead to cardiovascular disease. Multiple distinct posttranscriptional modifications of Drp1 have been reported, among which S-nitrosylation was recently introduced. However, the detailed regulatory mechanism of S-nitrosylation of Drp1 (SNO-Drp1) in cardiac microvascular dysfunction in diabetes remains elusive. The present study revealed that mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) was consistently upregulated in diabetic cardiomyopathy (DCM) and promoted SNO-Drp1 in cardiac microvascular endothelial cells (CMECs), which in turn led to mitochondrial dysfunction and cardiac microvascular disorder. Further studies confirmed that MAP4K4 promoted SNO-Drp1 at human C644 (mouse C650) by inhibiting glutathione peroxidase 4 (GPX4) expression, through which MAP4K4 stimulated endothelial ferroptosis in diabetes. In contrast, inhibition of MAP4K4 via DMX-5804 significantly reduced endothelial ferroptosis, alleviated cardiac microvascular dysfunction and improved cardiac dysfunction in db/db mice by reducing SNO-Drp1. In parallel, the C650A mutation in mice abolished SNO-Drp1 and the role of Drp1 in promoting cardiac microvascular disorder and cardiac dysfunction. In conclusion, our findings demonstrate that MAP4K4 plays an important role in endothelial dysfunction in DCM and reveal that SNO-Drp1 and ferroptosis activation may act as downstream targets, representing potential therapeutic targets for DCM.

The purpose of this research is financing options for high-tech enterprises in China during their early-stage. This study develops a three-phase model to analyze the financing choices of Chinese high-tech firms between banking and venture capital while considering information asymmetry. The findings reveal that opaque information disclosure favors venture capital financing, while transparent disclosure leads to bank loans for equally qualified high-tech enterprises. Data analysis further confirms that both bank loans and venture capital are viable options for early-stage Chinese high-tech enterprises. These findings offer valuable guidance for high-tech firms and investors navigating China’s financial landscape. Moreover, policy management departments can leverage these insights to make informed decisions and facilitate the financing of high-tech enterprises. JEL Classification : C70, C23, D22, G24.

The high ductility of Mg-Li alloy has been mainly ascribed to a high activity of pyramidal slip to accommodate plastic strain. In the present study, however, a quantitative analysis reveals that Li-addition can only slightly stimulate the activation of pyramidal slip under compression along the normal direction of a hot-rolled Mg-4.5 wt.% Li plate, with a relative activity of approximately 18%. Although the limited activity of pyramidal slip alone cannot accommodate a large plastic strain, it effectively reduces the number of {101¯1}−{101¯2} double twins, which are believed to be favorable sites for crack initiation. The evidently reduced activity of double twins leads to a lower cracking tendency, and therefore improves ductility.

Extracting agricultural parcel boundaries from remote sensing images based on deep learning methods is currently the most promising method. Due to the diversity of agricultural types and limitations of deep learning networks, parcel boundaries extracted by edge detection deep learning networks lack target specificity, and parcel boundaries extracted by semantic segmentation deep learning networks generally causes a loss of precise boundary information. Based on the principles of multi-task deep learning networks Psi-Net, BsiNet, and ResUNet-a, we constructed a parallel multi-task deep learning network M_ResUnet. The M_ResUnet is capable of performing edge detection and semantic segmentation simultaneously, and it is designed for extracting agricultural parcel boundaries from high-resolution remote sensing images. To improve the effectiveness of parcel boundary recognition, the edge enhancement concept from the context-aware tracing strategy (CATS) is introduced into the M_ResUnet, which enhanced the continuity and effectiveness of parcel boundary recognition and accelerated network training convergence. Finally, we conducted experiments on three different study areas with different remote sensing data sources and agricultural parcel types. The experimental results demonstrate that the method we proposed achieved better continuity in identifying parcel boundaries, and it also improved the recognition of boundaries between neighboring parcels with strong similarities remote sensing features such as texture and spectral characteristics.

Cu–Fe composite is a promising candidate for electromagnetic shielding material, while it exhibits poor corrosion resistance due to the different corrosion potential of Fe particles and Cu matrix. In this study, a Cu–Fe composite was processed by multi-directional compression. The effect of multi-directional compression on the mechanical properties of the Cu–Fe composite was evaluated by the tensile test, and the effect of multi-directional compression on the corrosion properties was evaluated by the weight loss test and electrochemical measurement. After 12 compression passes, the yield strength of the Cu–Fe composite is more than two times higher than that of the initial state, and the corrosion rate decreases to nearly half compared to the initial state. Microstructure examination reveals that high density of twin boundaries were generated by multi-directional compression, which could effectively refine the grain size of Cu matrix and improve the strength of Cu–Fe composite. In addition, twin boundaries would reduce the Volta potential difference between Cu matrix and Fe particles, which could effectively inhibit galvanic corrosion, finally leading to a high corrosion resistance of the Cu–Fe composite.

Yellow catfish is one of the most important aquaculture species in China, with an annual output of 565,000 tons. Between May and July 2022, the farmed yellow catfish experienced an unusually high mortality rate in an aquaculture farm next to Futou Lake in Hubei, China. Diseased fish exhibited symptoms including ascites, skin ulcers, and bleeding in the head, oral cavity, and lower jaw base. Polymerase chain reaction (PCR) and sequence analyses confirmed the co-infection of Yellow Catfish Calicivirus (YcCV) and Aeromonas veronii in the diseased fish. Transmission electron microscopy exposed abundant virus particles within kidney and spleen cells, characterized by their spherical shape and approximate diameter of 35 nm. Historically, the ascites disease in yellow catfish has been predominantly attributed to bacterial infections over the past two decades. This study represents the first documentation of a correlation between the ascites disease of yellow catfish and the natural co-infection of YcCV and Aeromonas veronii. The findings suggest a possible synergistic interaction between YcCV and bacterial pathogens, potentially aggravating disease severity in yellow catfish aquaculture.

The aim of the current study was to explore the potential of human plasma-derived exosomes as versatile carriers for drug delivery by employing various active and passive loading methods. Exosomes were isolated from human plasma using differential centrifugation and ultrafiltration method. Drug loading was achieved by employing sonication and freeze thaw methods, facilitating effective drug encapsulation within exosomes for delivery. Each approach was examined for its effectiveness, loading efficiency and ability to preserve membrane stability. Methotrexate (MTX), a weak acid model drug was loaded at a concentration of 2.2 µM to exosomes underwent characterization using various techniques such as particle size analysis, transmission electron microscopy and drug loading capacity. Human plasma derived exosomes showed a mean size of 162.15 ± 28.21 nm and zeta potential of −30.6 ± 0.71 mV. These exosomes were successfully loaded with MTX demonstrated a better drug encapsulation of 64.538 ± 1.54 % by freeze thaw method in comparison 55.515 ± 1.907 % by sonication. In-vitro drug release displayed 60 % loaded drug released within 72 h by freeze thaw method that was significantly different from that by sonication method i.e., 99 % within 72 h (p value 0.0045). Moreover, cell viability of exosomes loaded by freeze thaw method was significantly higher than that by sonication method (p value 0.0091) suggested that there was membrane disruption by sonication method. In conclusion, this study offers valuable insights into the potential of human plasma-derived exosomes loaded by freeze thaw method suggest as a promising carrier for improved drug loading and maintenance of exosomal membrane integrity.

Cu–Fe alloys are expected to be extensively used in electronics, transportation and machinery industries due to the extraordinary mechanical properties and functional properties. To optimize rolling process and the final properties of Cu–Fe plates. The effect of rolling path, rolling temperature and thickness reduction on microstructure evolution, mechanical and electrical properties of Cu–Fe alloy are carefully investigated. The results shown that the thickness reduction has a significant effect on mechanical properties of Cu–Fe alloy. The yield strength of Cu–Fe plates with 20% thickness reduction is more than 2 times higher than that of homogenized ingot. While the yield strength increases gradually as further increasing the thickness reduction. Rolling temperature is an important parameter determining the strength-ductility balance. The strength of plate rolled with 80% thickness reduction at 400 °C is similar to that of the plates in cold-rolled state, and the ductility is higher than that for the plates in the cold-rolled state. Further investigation reveals that the formation of heterogeneous structure characterized with recrystallized-fine grains embedded in deformed-coarse grains is responsible for the observed extraordinary mechanical properties. Rolling path could also affect the microstructure evolution and formability of the plates. For plate rolled with route 1 (unidirectional rolling), a stronger Copper-type texture with two Brass-type textures are observed. For plate rolled with route 2, where the rolled plate is rotated to 90° with respect to previous rolling direction between adjacent rolling passes, only Brass-type texture is generated. A rolling-path dependent edge-crack behavior is observed during rolling. Edge cracks are generated during rolling with route 2, while the edge cracks are not observed for plates rolled with route 1. Factors affecting the edge-cracks behavior are also discussed.

BackgroundThe pathogenesis of silicosis is complex and treatment methods are limited. SiO2-induced increase of transforming growth factor-β1 (TGF-β1) can activate fibroblasts to promote collagen deposition, ultimately leading to fibrosis. Previous studies have confirmed that lipid metabolism plays an important role in the progression of silicosis. Peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) mediates mitochondrial dysfunction and lipid metabolism pathways in diabetic models, but its role in silicosis has not been elucidated. ObjectiveTo investigate the effect of PGC1α on lipid metabolism disorder of macrophages induced by SiO2 and its effect on the progression of silicosis fibrosis. Methods(1) Macrophages were divided into four groups by transfecting and silencing PGC1α and its control sequence in macrophages and followed by SiO2 stimulation: negative control group (transfected with si-NC for 48 h), si-PGC1α group (transfected with si-PGC1α for 48 h), SiO2 stimulation group (stimulated with 50 μg·mL−1 SiO2 for 36 h after transfection with si-NC for 48 h), and si-PGC1α+SiO2 group (stimulated with 50 μg·mL−1 SiO2 for 36 h after transfection with si-PGC1α for 48 h). Western blot and cell immunofluorescence were used to test PGC1α expression, 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY 493/503) and total cholesterol (TC) and free cholesterol (FC) kits were used to test lipid accumulation, and the Oroboros2k-Oxygraph respiratory test system (O2K) was used to assess the effects of PGC1α on mitochondrial respiratory chain. ELISA kits were used to test TGF-β1 expressed in the macrophage supernatant. (2) Lung fibroblasts were divided into the same four groups as above, and stimulated with the supernatant of macrophages in the above groups. The expression of collagen Ι (COL Ι), E-cadherin (Eca), and fibronectin (FN) were detected by cell immunofluorescence and Western blot to further evaluate the effect of silencing PGC1α on fibrosis. ResultsThe protein expression level of PGC1α stimulated by SiO2 was decreased, and the relative expression level of PGC1α was 0.78 times that of the control group (P

The diatom Phaeodactylum tricornutum, known for its high triacylglycerol (TAG) content and significant levels of n-3 long chain polyunsaturated fatty acids (LC-PUFAs), such as eicosapentaenoic acid (EPA), has a limited ability to utilize exogenous organic matter. This study investigates the enhancement of acetate utilization in P. tricornutum by introducing an exogenous acetate transport protein. The acetate transporter gene ADY2 from Saccharomyces cerevisiae endowed the organism with the capability to assimilate acetate and accelerating its growth. The transformants exhibited superior growth rates at an optimal NaAc concentration of 0.01 M, with a 1.7- to 2.0-fold increase compared to the wild-type. The analysis of pigments and photosynthetic activities demonstrated a decline in photosynthetic efficiency and maximum electron transport rate. This decline is speculated to result from the over-reduction of the electron transport components between photosystems due to acetate utilization. Furthermore, the study assessed the impact of acetate on the crude lipid content and fatty acid composition, revealing an increase in the crude lipid content and alterations in fatty acid profiles, particularly an increase in C16:1n-7 at the expense of EPA and a decrease in the unsaturation index. The findings provide insights into guiding the biomass and biologically active products production of P. tricornutum through metabolic engineering.

Abstract For high‐power converters, the low switching frequency (SF) modulation represented by selective harmonic elimination pulse width modulation (SHE‐PWM) is crucial to reduce the switching loss and enhance the efficiency with a good steady‐state performance. However, since the advantages of SHE‐PWM mainly come from the fixed switching angle distribution limited by non‐linear equations, switching angles should be adjusted slowly. This requires that the bandwidth of proportional integral (PI) controllers be limited hugely, resulting in a poor dynamic response. As the most popular control to improve the dynamic response, finite‐control‐set model predictive control (FCS‐MPC) has a worse steady‐state performance under low SF because of large errors caused by a long prediction period and harmonics caused by space vector PWM (SVPWM). Therefore, a hybrid modulation strategy with an acceptable complexity is proposed in this article, which combines SHE‐PWM and FCS‐MPC. PI + SHE‐PWM is adopted in a steady state with low SF, while MPC + SVPWM is used in a transient state with high SF. By studying smooth switching from the modulation level and control level, the proposed method can eliminate the current surge when switching between PI + SHE‐PWM and MPC + SVPWM. Experiments verify that the proposed method have a good steady‐state performance and high dynamic response simultaneously under overall low SF.

BackgroundRecent studies have shown that obesity may contribute to the pathogenesis of benign prostatic hyperplasia (BPH). However, the mechanism of this pathogenesis is not fully understood.MethodsA prospective case-control study was conducted with 30 obese and 30 nonobese patients with BPH. Prostate tissues were collected and analyzed using ultra performance liquid chromatography ion mobility coupled with quadrupole time-of-flight mass spectrometry (UPLC-IMS-Q-TOF).ResultsA total of 17 differential metabolites (3 upregulated and 14 downregulated) were identified between the obese and nonobese patients with BPH. Topological pathway analysis indicated that glycerophospholipid (GP) metabolism was the most important metabolic pathway involved in BPH pathogenesis. Seven metabolites were enriched in the GP metabolic pathway. lysoPC (P16:0/0:0), PE (20:0/20:0), PE (24:1(15Z)/18:0), PC (24:1(15Z)/14:0), PC (15:0/24:0), PE (24:0/18:0), and PC (16:0/18:3(9Z,12Z,15Z)) were all significantly downregulated in the obesity group, and the area under the curve (AUC) of LysoPC (P-16:0/0/0:0) was 0.9922. The inclusion of the seven differential metabolites in a joint prediction model had an AUC of 0.9956. Thus, both LysoPC (P-16:0/0/0:0) alone and the joint prediction model demonstrated good predictive ability for obesity-induced BPH mechanisms.ConclusionsIn conclusion, obese patients with BPH had a unique metabolic profile, and alterations in PE and PC in these patients be associated with the development and progression of BPH.

Titanium (Ti) particles reinforced AZ91 matrix composite (Tip/AZ91) was prepared by powder metallurgy method. In the present work, we investigated the hot deformation behavior of Tip/AZ91 composite by isothermal compression tests at a range of temperature from 250 °C to 400 °C and strain rates from 0.001 s−1 to 1 s−1. Microstructure observations revealed that Ti particles were distributed uniformly in the composite, with the presence of a diffusion layer containing Mg, Ti, and Al elements between the Ti particles and the magnesium (Mg) matrix. The strain-compensated Arrhenius constitutive model was constructed, and the accuracy was evaluated by error analysis. The stress index exponent (n) was calculated as 4.98, indicating that the dislocation climb mechanism dominates the thermal deformation of Tip/AZ91 composite. Moreover, the calculated activation energy (Q) of 153.7 kJ/mol was observed to be lower than that of the pure AZ91 alloy, which can be attributed to the presence of a particle deformation zone (PDZ). Further microstructure analysis indicated that the continuous dynamic recrystallization mechanism (CDRX) occurred. As the recrystallized grains grow, the texture changes from a bimodal texture to a typical unimodal texture, resulting in a recrystallized //normal direction texture. In addition, the particle stimulated nucleation (PSN) phenomenon was observed around Ti particles at low Zener-Hollomon parameter (lnZ = 20.73) condition.

A new type of graphene electric heating solid wood composite floor and its heat transfer model were designed to enable users to have a higher-quality and safe living experience. A heat transfer mathematical model was developed. The structural entity of the composite graphene heating floor was drawn using Solidworks software. The floor structure was abstracted as a two-dimensional model using MATLAB software to obtain the temperature rise curves and corresponding time of each group. Then, six groups of the best data were selected from the experimental data to simulate the heat storage capacity of graphene floors. The optimal group of the model was verified via experiments. According to the simulation, the comprehensive performance was optimal when the overall thickness of the floor was 18 mm, the thickness of the floor surface was 4 mm, and the thickness of the heat-accumulating layer was 2 mm. The experimental results showed a maximum difference between the measured and calculated data of only 3.2%, which shows the scientific validity, accuracy, and advancement of the model. The composite graphene electric heating energy storage floor designed in this study can be regarded as safe, reliable, environmentally friendly, and healthy.

With the quick development of mobile light detection and ranging (LiDAR) systems, point clouds are frequently applied for various large-scale outdoor scenes. It is fundamental to quickly and accurately classify objects of mobile laser scanning (MLS) point clouds in such urban scene applications. However, an important problem is the need for massive training samples in object classification. High computational cost is also a common challenge. To overcome them, a knowledge-based multi-scale adaptive classification approach (KMAC) is proposed in the paper. The method consisting of four layers derives from a normal neural network framework, the operation in part layers differ. As the scale difference of various objects in natural environment, 3D multi-scale spatial local relation of objects is explored with inspiration by the idea of convolution. Two types of distinguishable features of actual objects are explored to describe 3D point clouds by a 2D vector representation. Then, human knowledge is used to directly build an end-to-end match between these feature descriptions in 2D and 3D point clouds of actual objects. Point clouds which are adjacent with the same feature representation would be intentionally integrated into multiple adaptive regions. The adaptive integration solves scale difference of various objects. The direct match by knowledge exactly plays the role of training samples. Qualitative and quantitative experimental results on three data-sets finally show the proposed approach is promising to efficiently classify unlabeled objects in urban scenes.

Abstract Background The relationship between triglyceride-glucose (TyG) index, an emerging marker of insulin resistance, and the risk of incident heart failure (HF) was unclear. This study thus aimed to investigate this relationship. Methods Subjects without prevalent cardiovascular diseases from the prospective Kailuan cohort (recruited during 2006–2007) and a retrospective cohort of family medicine patients from Hong Kong (recruited during 2000–2003) were followed up until December 31st, 2019 for the outcome of incident HF. Separate adjusted hazard ratios (aHRs) summarizing the relationship between TyG index and HF risk in the two cohorts were combined using a random-effect meta-analysis. Additionally, a two-sample Mendelian randomization (MR) of published genome-wide association study data was performed to assess the causality of observed associations. Results In total, 95,996 and 19,345 subjects from the Kailuan and Hong Kong cohorts were analyzed, respectively, with 2,726 cases of incident HF in the former and 1,709 in the latter. Subjects in the highest quartile of TyG index had the highest risk of incident HF in both cohorts (Kailuan: aHR 1.23 (95% confidence interval: 1.09–1.39), P Trend

Organic metal chalcogenides (OMCs) are organic-inorganic hybrid materials with continuous M-X (X = S, Se, Te) networks that are covalently connected by organic ligands. Here authors report a family of bimetallic OMCs synthesized via selective metal metathesis and oxidation transformation.

Ionizing radiation (IR)-induced hematopoietic injury has become a global concern in the past decade. The underlying cause of this condition is a compromised hematopoietic reserve, and this kind of hematopoietic injury could result in infection or bleeding, in addition to lethal mishaps. Therefore, developing an effective treatment for this condition is imperative. Fluacrypyrim (FAPM) is a recognized effective inhibitor of STAT3, which exhibits anti-inflammation and anti-tumor effects in hematopoietic disorders. In this context, the present study aimed to determine whether FAPM could serve as a curative agent in hematopoietic-acute radiation syndrome (H-ARS) after total body irradiation (TBI). The results revealed that the peritoneally injection of FAPM could effectively promote mice survival after lethal dose irradiation. In addition, promising recovery of peripheral blood, bone marrow (BM) cell counts, hematopoietic stem cell (HSC) cellularity, BM colony-forming ability, and HSC reconstituting ability upon FAPM treatment after sublethal dose irradiation was noted. Furthermore, FAPM could reduce IR-induced apoptosis in hematopoietic stem and progenitor cells (HSPCs) both in vitro and in vivo. Specifically, FAPM could downregulate the expressions of p53-PUMA pathway target genes, such as Puma, Bax, and Noxa. These results suggested that FAPM played a protective role in IR-induced hematopoietic damage and that the possible underlying mechanism was the modulation of apoptotic activities in HSCs.

Abstract. Background:. Changes in thyroid hormone levels are commonly recognized characters among the elderly, which were reported to potentially influence incident frailty. Therefore, we examined the cross-sectional associations of thyroid hormones (THs) with frailty as well as the five components characterizing frailty (fatigue, resistance, ambulation, number of illnesses, and loss of weight) among the oldest-old. Methods:. Four hundred and eighty-seven community-dwelling oldest-old from a local community in Haidian District, Beijing, participated in our recruitment campaign between April 2019 and May 2020. The primary outcomes were a definitive diagnosis of frailty according to the FRAIL scale (Fatigue, Resistance, Ambulation, Illnesses, Loss of weight) and a positive score for each frailty subdomain. Demographic information (age, sex, marital status, and educational status), comorbidities, and details on the participants’ lifestyles were recorded. Serum THs including free triiodothyronin (fT3), triiodothyronine (T3), free thyroxine (fT4), and thyroxine (T4) and thyroid stimulating hormone (TSH) levels were also measured at the beginning of our study. Logistic regressions were conducted to screen for potential risk factors for frailty and its subdomains. Results:. Among the total 487 subjects at enrollment, 60 (12.23%) of them were diagnosed with subclinical hypothyroidism and 110 (22.59%) of the total population scored positive for frailty. Logistic regression analyses adjusted for all potential confounders, showed that frailty was significantly associated with the serum TSH concentration (odds ratio [OR]: 1.06), fT3 concentration (OR: 0.54), and subclinical hypothyroidism score (OR: 2.18). The association between fT4 and frailty was absent in our observational study. The fT3/fT4 ratio characterizing peripheral hormone conversion was also tested to be correlated with frailty. Conclusion:. Subclinical hypothyroidism, higher TSH level, lower fT3 level, and decreased fT3/fT4 ratio were all associated with frailty assessed by the FRAIL scale among the community-dwelling oldest-old, suggesting a relevant role of thyroid function in aging. Future longitudinal studies are warranted to determine the casual relationship between thyroid dysfunction and frailty in the oldest-old.

Estuarine wetlands are highly heterogeneous due to strong interactions between freshwater input and seawater intrusion. However, little is known about how clonal plant populations adapt to heterogeneous salinity in soil environments. In the present study, the effects of clonal integration on Phragmites australis populations under salinity heterogeneity were studied using field experiments with 10 treatments in the Yellow River Delta. Clonal integration significantly increased plant height, aboveground biomass, underground biomass, root–shoot ratio, intercellular CO2 concentration, net photosynthetic rate, stomatal conductance, transpiration rate, and stem Na+ content under homogeneous treatment. Under the heterogeneous salt treatment, clonal integration significantly affected total aboveground and underground biomass, photosynthetic traits, and stem Na+ content under different salt gradients. The increase in salt concentration inhibited the physiological activity and growth of P. australis to varying degrees. Compared with the heterogeneous saline environment, clonal integration was more beneficial to P. australis populations in the homogeneous saline habitat. The results of the present study suggest that P. australis prefers homogeneous saline habitats; however, plants can adapt to heterogeneous salinity conditions via clonal integration.

This study investigates the impact of strain rate on the twinning process (i.e., twin nucleation, twin propagation, and twin growth) and associated mechanical behavior during compression along the normal direction (ND) and transverse direction (TD) of a rolled AZ31 Mg plate at a range of strain rates from 0.00005 s−1 to 2500 s−1. The findings reveal that the yield strength is insensitive to strain rates below 0.05 s−1 during both ND and TD compression tests, while at higher strain rates of 2500 s−1, the yield strength increases under both loading conditions. Interestingly, the TD-compressed sample exhibits a larger yield plateau at a strain rate of 2500 s−1, attributed to an increased activation of {101¯2} twins. Further examination of the microstructure reveals that the twinning process is highly dependent on the strain rate. As the strain rate increases, twin nucleation is promoted, leading to a higher twin boundary density. In contrast, at lower strain rates, twin nucleation is restrained, and the external strain is mainly accommodated by twin growth, which results in higher area fractions of twinned regions.

Organic thermoelectric (OTE) materials offer a direct way to harvest electricity from heat resources. Although OTE paints can be coated on irregular heat sources via various solution‐processing techniques, most candidates are only soluble in toxic organic solvents and require complex preparation method, limiting their wide industrial applications. Herein, an environment‐friendly waterborne colloid based on a selenium‐substituted diketopyrrolopyrrole derivative (PDPPSe‐12) is utilized using a miniemulsion process to enable water‐dispersive OTE paints. The doped films not only exhibit prominent electrical conductivity and high Seebeck coefficient, but also show unexpected low thermal conductivity, yielding a maximum power factor and figure of merit value of up to 74.77 ± 1.76 μW m−1 K−2 and 0.14, respectively. More importantly, their application potential in a realistic thermoelectric generator (TEG) on a paper substrate by painting is demonstrated, which possesses an output power of 14.70 nW under a temperature difference of 19 K. For the first time, these results reveal that the fabrication of waterborne OTE paints can decrease the thermal conductivity and its integrated organic TEGs exhibit preferable performance. These results offer valuable insights for designing high‐performance OTE paints toward multiple‐energy supplier systems in an environmentally friendly way.

Background: The association between serum bilirubin level and heart failure (HF) was controversial in previous observational studies and the causal effects of bilirubin on HF have not been investigated. Here, we conducted a Mendelian randomization (MR) study to investigate the associations between genetically determined bilirubin level and HF.Methods: Summary data on the association of single nucleotide polymorphisms (SNPs) with serum bilirubin levels were obtained from genome-wide association study (GWAS) for individuals of European descent and East Asian descent separately. Statistical data for gene-HF associations were extracted from three databases: the HERMES Consortium (47,309 cases and 930,014 controls), FinnGen study (30,098 cases and 229,612 controls) for European population and Biobank Japan (2,820 HF cases and 192,383 controls) for East Asian population. We applied a two-sample Mendelian randomization framework to investigate the causal association between serum bilirubin and HF.Results: Findings from our MR analyses showed that genetically determined serum bilirubin levels were not causally associated with HF risk in either European or East Asian population (odds ratio [OR] = 1.01 and 95% confidence interval [CI] = .97–1.05 for HERMES Consortium; OR = 1.01 and 95% CI = .98–1.04 for FinnGen Study; OR = .82, 95% CI: .61–1.10 for Biobank Japan). These results remained unchanged using different Mendelian randomization methods and in sensitivity analyses.Conclusion: Our study did not find any evidence to support a causal association between serum bilirubin and HF.

Tidal hydrology has an important effect on anaerobic carbon decomposition in estuary wetlands. However, it remains unclear how soil anaerobic CO2 production responds to change in tidal hydrology. We differentiated anaerobic CO2 production of freshwater marsh soil exposed to different tidal hydrology in the Yellow River estuary wetland. For this purpose, soil cores of a freshwater marsh with no-tidal hydrology were translocated to and cultured in the three tidal salt marshes with different tidal hydrology, respectively. Over 16-month culture, change in tidal hydrology significantly affected properties and anaerobic CO2 production of freshwater marsh soil. Exposure to tidal hydrology had increased pH and electrical conductivity (EC) of freshwater marsh soil, while decreased organic carbon (TOC), dissolved organic carbon (DOC) and C:N ratios. Anaerobic CO2 production of freshwater marsh soil showed a significantly reduction after exposed to different tidal hydrology conditions, with the corresponding mean decreasing from 2.53 μgC·g−1·d−1 under the no-tidal hydrology to 1.09–2.10 μgC·g−1·d−1 under the different tidal hydrology. Soil anaerobic CO2 production were negatively correlated with pH and EC, and positively correlated with TOC, DOC and C:N ratios, with a total 92.6% explanation of soil properties for the change in anaerobic CO2 production. The results suggest that soil anaerobic CO2 production of freshwater marsh soil might be inhibited when exposed to seawater intrusion due to the rise of salt and the decrease of substrate quality.

Immiscible Cu-Fe alloys exhibit poor corrosion resistance due to different corrosion potentials between the constituent phases, which limits their application. In this paper, a composite gradient-structured Cu-10 wt.%Fe plate was prepared via the ultrasonic surface rolling process (USRP). The microstructure evolution, mechanical properties and corrosion behavior were studied. The results demonstrate that USRP effectively enhances both the strength and corrosion resistance of the Cu-10Fe alloy. The improved strength is related to the combined effects of Hall–Petch strengthening, dislocation strengthening, and additional strengthening resulting from homogeneous deformation between the surface layer and the matrix. The enhanced corrosion resistance is primarily attributed to the refined microstructure of the surface layer after USRP, which facilitates the formation of a protective passivation film.

Through development of non-fullerene acceptors, OPVs have reached efficiencies of 18%, yet the inadequate operational lifetime still poses a challenge for the commercialisation. Here, the authors investigate the origin of instability of NFA solar cells, and propose some strategies to mitigate this issue.

Conventional ultrafine grains can generate high-strength Mg alloys, but non-equilibrium grain boundaries deteriorates their corrosion resistance. Here, the authors present ultrafine grained Mg alloys with dense twins that display high strength and reduced corrosion rate by one order of magnitude.

Phragmites australis is highly adaptable with high competitive ability and is widely distributed in the coastal wetland of the Yellow River Delta. However, allelopathic effects of P. australis on the growth of neighboring plants, such as Suaeda salsa, are poorly understood. In this study, germination responses of S. salsa seeds collected from two different habitats (intertidal zone and inland brackish wetland) to the extracts from different part of P. australis were compared. Potential allelopathic effects on germination percentage, germination rate, radicle length, and seedling biomass were analyzed. The germination of S. salsa was effectively inhibited by P. australis extract. Extract organ, extract concentration, and salt concentration showed different effects, the inhibitory rates were highest with belowground extract of P. australis between the four different parts. Germination percentage and germination rate were significantly decreased by the interactive effect of salt stress and extract concentration in S. salsa from a brackish wetland but not in S. salsa from the intertidal zone. The impact of different extracts of P. australis on radicle length and seedling biomass of S. salsa showed significant but inconsistent variation. The response index results showed that the higher concentration of extract solution (50 g·L−1) of P. australis had stronger inhibitory effect on the seed germination and seedling growth of S. salsa while the belowground extract had the strongest negative effect. Our results indicated that allelopathy is an important ecological adaptation mechanism for P. australis to maintain a high interspecific competitive advantage in the species’ natural habitat.

Blocking of hydrological connectivity could greatly impact the sediment deposition process and change water and salinity conditions, which in turn affect plant germination, growth, and development in delta wetlands. A 2-year experiment, which included the effects of soil burial, water, and salinity on germination, growth, and production, was conducted to examine the function of hydrological connectivity blocking on the development of Suaeda salsa, a halophyte species. The results demonstrated that soil burial, water, and salinity all had significant effects on seed germination, plant growth, and production (p < 0.05). Seed germination decreased as soil buried depth increased (< 4 cm), and seeds did not germinate successfully when the buried depth was > 4 cm. Seed germination was the highest at 0 cm burial. However, moderate burial was beneficial for seedling emergence; therefore, the survival rate was the lowest when seeds were distributed at the surface (0 cm). Water and salinity both significantly affected the germination, growth, and productivity of S. salsa. Moderate salinity (10–20 g/kg) and fluctuating water (0–10 cm water depth) were suitable for seed germination and plant growth. Low salinity (< 10 g/kg), High salinity (>20 g/kg), drought, and high water levels (long-term flooding with water depth > 10 cm) were not conducive to the growth of S. salsa, and biomass and seed yield were also reduced. As a halophyte, salinity that is too low or too high is unsuitable for S. salsa population. Water and salinity also significantly affected S. salsa population (p < 0.05). In particular, water can offset the hazards of high salt concentrations. Blocking of hydrological connectivity can influence seed germination, yield, and vitality. In this case, S. salsa may have died out from the coastal wetland due to the lack of hydrological connectivity restoration.

Tidal creeks have attracted considerable attention in estuary wetland conservation and restoration with diverse micro-habitats and high hydrological connectivity. Bacterial communities act effectively as invisible engines to regulate nutrient element biogeochemical processes. However, few studies have unveiled the bacterial community structures and diversities of micro-habitats soils on the tidal creek section. Our study selected three sections cross a tidal creek with obviously belt-like habitats “pluff mudflat – bare mudflat – Tamarix chinensis community – T. chinensis-Suaeda salsa community– S. salsa community” in the Yellow River estuarine wetland. Based on soil samples, we dissected and untangled the bacterial community structures and special bacterial taxa of different habitats on the tidal creek section. The results showed that bacterial community structures and dominant bacterial taxa were significantly different in the five habitats. The bacterial community diversities significantly decreased with distance away from tidal creeks, as well as the dominant bacteria Flavobacteriia and δ-Proteobacteria, but in reverse to Bacteroidetes and Gemmatimonadetes. Moreover, the important biomarkers sulfate-reducing bacteria and photosynthetic bacteria were different distributions within the five habitats, which were closely associated with the sulfur and carbon cycles. We found that the bacterial communities were heterogeneous in different micro-habitats on the tidal creek section, which was related to soil salinity, moisture, and nutrients as well as tidal action. The study would provide fundamental insights into understanding the ecological functions of bacterial diversities and biogeochemical processes influenced by tidal creeks.

The soils from four typical natural wetlands, namely, Phragmites australis, Tamarix chinensis, Suaeda salsa, and tidal flat, as well as reclaimed wetland, were selected to evaluate the soil quality in the Yellow River Delta. Fourteen soil physicochemical property indexes were employed to build a minimum data set (MDS). Combined with vegetation type and soil depth, the soil quality index (SQI) was conducted. A fuzzy logic model was applied for data normalization. The contrast test was conducted to verify the accuracy of the MDS. The results showed that the MDS consists of TOC, NO3--N, soil salinity, TS, TP, Mg, C/N and pH. The soil quality decreased from the inland to the coastline and from reclaimed wetland to tidal flat with the change of vegetation type. The soil quality of 0–10 cm soil depth was better than that of 20–30 cm soil depth. The soil qualities of reclaimed land were significantly better than those of natural wetlands at the same soil depth. Correlation analysis results showed that agricultural reclamation has become an important factor of soil quality change in the study area. Comparative results of two methods of MDS and the total data set (TDS) testified that the method of MDS was credible and accurate for soil quality assessment of the study area. Our results indicated that wetland protection and agricultural reclamation in coastal areas should keep a rational balance.

The arrangements of defect lines in liquid crystal blue phases provide promising templates for photonic crystals. Here Liu et al. investigate in detail how inter-phase transitions proceed, by intercepting nucleation with on-demand cross linking of a supporting polymer matrix.

The regeneration of functional tendons remains a clinical challenge. Here the authors develop a biomimetic scaffold loaded with recombinant periostin and demonstrate its functionality in promoting tendon stem/progenitor cell recruitment and tenogenic differentiation, and tendon regeneration in a rat full-cut Achilles tendon defect model.

Suppressing grain boundaries and defects in perovskite solar cells remains a quest to address the efficiency and stability issues. Here, the authors use methylamine gas for assisting the growth of uniaxial-oriented perovskite thin films with millimeter-sized grains.

In this paper, an improved commutative encryption and data hiding scheme for bit rate preservation of High Efficiency Video Coding (HEVC) is proposed. To achieve commutative property, one set of syntax elements within the HEVC standard is utilized for data hiding, while another set is exploited for encryption. Specifically, the syntax elements including the sign of quantized transform coefficient (QTC), the sign of motion vector difference (MVD), and the magnitude of MVD are encrypted to perceptually distort the video. On the other hand, an improved QTC modification method is employed for data hiding to increase the embedding capacity. The proposed framework produces the format compliant bitstream and allows the hidden information to be extracted regardless of the video being in the encrypted or decrypted from. Experimental results demonstrate that the proposed scheme keeps the bit rate unchanged while increasing the embedding capacity.

Iron is a limiting factor that controls the phytoplankton biomass of the ocean and plays an important role in the lipid production of microalgae. Elucidating the effects of different iron valences on microalgae is helpful for their commercial production. We investigated the growth, photosynthesis, and fatty acid profile of the model diatom Phaeodactylum tricornutum cultured with depleted Fe, Fe2+, Fe2+/Fe3+, and Fe3+. Samples were taken every 24 h for 8 days, and their cell density, photosynthetic pigment content, chlorophyll fluorescence, total fatty acid content, and fatty acid composition were analyzed. The cell densities of the Fe2+ and Fe2+/Fe3+ groups were significantly higher than those of the control and Fe3+ groups (p < 0.05). They were 1.26 times and 1.23 times higher than those in the Fe-depleted group. The contents of chlorophyll a and c in the Fe2+ group were significantly higher than those in the Fe-depleted group (p < 0.05). The chlorophyll fluorescence results show that Fe2+ enhanced the photosynthesis of P. tricornutum to a greater extent than Fe3+. On the eighth day of harvest, Fv/Fm and Y(II) in the Fe2+ group were 0.672 and 0.476, respectively, being 1.10 and 1.19 times greater than those in the Fe3+ group and 1.15 and 1.33 times greater than those in the Fe-depleted group, respectively. Compared with the control group, the levels of saturated fatty acids of the Fe2+/Fe3+ and Fe3+ groups were significantly higher (p < 0.05) at 21.36 ± 1.24% and 21.20 ± 0.13%, respectively. The levels of polyunsaturated fatty acids of the Fe2+/Fe3+ group were significantly lower (p < 0.05) at 29.82 ± 2.75%. Our results show that P. tricornutum exhibited physiological plasticity, including changes in photosynthetic activities and shifts in fatty acid composition, in response to different iron valences and that Fe2+ was more beneficial to the biomass production of this species than Fe3+. These findings are applicable to the production of biomass and polyunsaturated fatty acids.

Background: Positive associations between inflammatory biomarkers and the risk of heart failure (HF) have been reported in conventional observational studies. However, the causal effects of inflammatory biomarkers on HF have not been fully elucidated. We conducted a Mendelian randomization (MR) study to examine the possible etiological roles of inflammatory biomarkers in HF.Methods: Summary statistical data for the associations between single nucleotide polymorphisms (SNPs) and C-reactive protein (CRP), fibrinogen, and components of the interleukin-1 (IL-1)-interleukin-6 (IL-6) inflammatory signaling pathway, namely, interleukin-1β (IL-1β), IL-1 receptor antagonist (IL-1ra), IL-6, and soluble IL-6 receptor (sIL-6r), were obtained from genome-wide association studies (GWASs) for individuals of European descent. The GWAS dataset of 977,323 participants of European ancestry, which included 47,309 HF cases and 930,014 controls, was collected to identify genetic variants underlying HF. A two-sample Mendelian randomization framework was implemented to examine the causality of the association between these inflammatory biomarkers and HF.Results: Our MR analyses found that genetically determined CRP and fibrinogen were not causally associated with HF risk (odds ratio [OR] = 0.93, 95% confidence interval [CI] = 0.84–1.02, p = 0.15; OR = 0.94, 95% CI = 0.55–1.58, p = 0.80, respectively). These findings remained consistent using different Mendelian randomization methods and in sensitivity analyses. For the IL-1-IL-6 pathway, causal estimates for IL-6 (OR = 0.86, 95% CI 0.81–0.91, p < 0.001), but not for IL-1β, IL-1ra, or sIL-6r, were significant. However, the association between genetically determined IL-6 and HF risk became non-significant after excluding SNPs with potential pleiotropy (OR = 0.89, 95% CI = 0.77–1.03, p = 0.12).Conclusion: Our study did not identify convincing evidence to support that CRP and fibrinogen, together with their upstream IL-1-IL-6 signaling pathway, were causally associated with HF risk.

Psychrophiles inhabiting various cold environments are regarded as having evolved diverse physiological and molecular strategies, such as the accumulation of trehalose to alleviate cold stress. To investigate the possible contributions of trehalose metabolism-related enzymes to cold-adaption in psychrotrophic bacteria and enrich the resource bank of trehalose hydrolysis enzymes, a novel cold-adapted GH15 GA-like trehalase (MpTre15A) from psychrotolerant Microbacteriumphyllosphaerae LW106 isolated from glacier sediments was cloned and characterized. The recombinant MpTre15A from M. phyllosphaerae LW106 was expressed and purified in Escherichia coli BL21(DE3). The purified MpTre15A functioned as a hexamer and displayed maximal activity at pH 5.0 and 50 °C. Substrate specificity assay proved MpTre15A only showed hydrolytic activity toward α,α-trehalose. Site-directed mutation verified the key catalytic sites of Glu392 and Glu557 in MpTre15A. The kcat and kcat/Km values of MpTre15A at 4 °C (104.50 s−1 and 1.6 s−1 mM−1, respectively) were comparable to those observed for thermophilic GH15 trehalases at 50 °C, revealing its typical cold-adaptability. MpTre15A showed a trehalose conversion rate of 100% and 99.4% after 10 min and 15 min of incubation at 50 °C and 37 °C, respectively. In conclusion, this novel cold-adapted α,α-trehalase MpTre15A showed potential application for developing therapeutic enzymes, enzyme-based biosensors, and enzyme additives in the fermentation industry.

Acrylamide, a II A carcinogen, widely exists in fried and baked foods. L-asparaginase can inhibit acrylamide formation in foods, and enzymatic stability is the key to its application. In this study, the Escherichia coli L-asparaginase (ECA) stable variant, D60W/L211R/L310R, was obtained with molecular dynamics (MD) simulation, saturation mutation, and combinatorial mutation, the half-life of which increased to 110 min from 60 min at 50 °C. Furthermore, the working temperature (maintaining the activity above 80%) of mutation expanded from 31 °C–43 °C to 35 °C–55 °C, and the relative activity of mutation increased to 82% from 65% at a pH range of 6–10. On treating 60 U/mL and 100 U/g flour L-asparaginase stable mutant (D60W/L211R/L310R) under uncontrolled temperature and pH, the acrylamide content of potato chips and bread was reduced by 66.9% and 51.7%, which was 27% and 49.9% higher than that of the wild type, respectively. These results demonstrated that the mutation could be of great potential to reduce food acrylamide formation in practical applications.

To study metal enrichment and identify the influencing factors, 106 surface soils were collected in the Yellow River delta, including ten vegetation types. Concentrations of 10 different metals, including As, Cd, Cr, Ni, Cu, Pb, Zn, Mn, Al, Fe, and physicochemical properties pH, salinity, particle size were detected. The pH value was 7.35~9.17, and the salinity was in the range of 0.01~2.00%. The average value of silt was 76.18%, which was the main particle size for 99% of the samples. The mean concentrations of As, Cd, Cr, and Ni were higher than the background value of Shandong Province or the background value of yellow soil in China. A higher concentration of Fe occurred in Phragmites australis (mean concentration 2.50%) and paddy field. The concentrations of Cd, Cr, Ni, Cu, Pb and Zn were lower in the Suaeda salsa soil. The Nemerow pollution index indicated that 79% of all samples showed low-level metal pollution, and 7% of all samples showed moderate-level metal pollution. In the areas with higher salinity, the concentrations of As were higher, while the concentrations of Cd and Ni were lower. The correlation analysis showed that with increasing pH, the concentrations of As and Zn decreased significantly. The metal concentrations had a significant positive correlation with clay, except for As.

Background and Aims: Long noncoding RNA (small nucleolar RNA host gene 7) has been reported to be involved in multiple malignancies and acts as an oncogene. However, the potential mechanism of small nucleolar RNA host gene 7 in glioblastoma is rarely known. In this study, we attempted to elucidate the biological effects of small nucleolar RNA host gene 7 and the possible molecular mechanism in glioblastoma. Methods: The expression level of small nucleolar RNA host gene 7 in glioblastoma tissues and corresponding tumor cell lines was evaluated by using quantitative real-time polymerase chain reaction. Bioinformatics analyses and dual-luciferase reporter gene assay were conducted to verify the correlation among small nucleolar RNA host gene 7, miR-449b-5p, and MYCN. The role of small nucleolar RNA host gene 7 on cell viability, migration, and invasion was measured. Results: Small nucleolar RNA host gene 7 expression was markedly increased in glioblastoma tumor tissue. Small nucleolar RNA host gene 7 can sponge miR-449b-5p and negatively regulate miR-449b-5p expression. MiR-449b-5p was remarkably repressed in glioblastoma tissues. Reduction of miR-449b-5p reversed the repressive effects of small nucleolar RNA host gene 7 knockdown on cellular behaviors in glioblastoma. In addition, miR-449b-5p can directly bind with MYCN. Compared with normal samples, MYCN expression was increased. The MYCN expression was negatively related to miR-449b-5p expression while positively related to small nucleolar RNA host gene 7 expression. Rescue experiments revealed that MYCN overexpression reversed the repressive role of small nucleolar RNA host gene 7 knockdown on viability, migration, and invasion of U251 cells. Conclusion: In summary, our results demonstrated that small nucleolar RNA host gene 7 regulates glioblastoma proliferation, migration, and invasion via regulating miR-449b-5p and its target gene MYCN, thereby providing a potential therapeutic target for glioblastoma.

Hydroxynitrile lyases (HNL's) belonging to the α/β-hydrolase-fold superfamily evolved from esterases approximately 100 million years ago. Reconstruction of an ancestral hydroxynitrile lyase in the α/β-hydrolase fold superfamily yielded a catalytically active hydroxynitrile lyase, HNL1. Several properties of HNL1 differ from the modern HNL from rubber tree (HbHNL). HNL1 favors larger substrates as compared to HbHNL, is two-fold more catalytically promiscuous for ester hydrolysis (p-nitrophenyl acetate) as compared to mandelonitrile cleavage, and resists irreversible heat inactivation to 35 °C higher than for HbHNL. We hypothesized that the x-ray crystal structure of HNL1 may reveal the molecular basis for the differences in these properties. The x-ray crystal structure solved to 1.96-Å resolution shows the expected α/β-hydrolase fold, but a 60% larger active site as compared to HbHNL. This larger active site echoes its evolution from esterases since related esterase SABP2 from tobacco also has a 38% larger active site than HbHNL. The larger active site in HNL1 likely accounts for its ability to accept larger hydroxynitrile substrates. Site-directed mutagenesis of HbHNL to expand the active site increased its promiscuous esterase activity 50-fold, consistent with the larger active site in HNL1 being the primary cause of its promiscuous esterase activity. Urea-induced unfolding of HNL1 indicates that it unfolds less completely than HbHNL (m-value = 0.63 for HNL1 vs 0.93 kcal/mol·M for HbHNL), which may account for the ability of HNL1 to better resist irreversible inactivation upon heating. The structure of HNL1 shows changes in hydrogen bond networks that may stabilize regions of the folded structure.

Dielectrics with high capacitive energy storage density are essential for modern electrical devices and pulsed power systems. Here, the authors realised superior energy storage performance in lead-free bismuth ferrite-based relaxor ferroelectric films through domain engineering.

Spartina alterniflora is one of the most noxious invasive plants in China and many other regions. Exploring environmentally friendly, economic and effective techniques for controlling Spartina alterniflora is of great significance for the management of coastal wetlands. In the present study, different approaches, including mowing and waterlogging, mowing and tilling and herbicide application, were used to control Spartina alterniflora. The results suggest that the integrated approach of mowing and waterlogging could eradicate Spartina alterniflora, the herbicide haloxyfop-r-methyl could kill almost all the Spartina alterniflora, and the integrated approach of mowing and tilling at the end of the growing season was a perfect way to inhibit the germination of Spartina alterniflora in the following year. However, no matter which control approach is adopted, secondary invasion of Spartina alterniflora must be avoided. Otherwise, all the efforts will be wasted in a few years.

The surveillance system, which is mainly used for detecting and tracking moving targets, is one of the most significant applications of wireless sensor networks. Up to present, received signal strength indicator is the most common measuring mean for estimating the distance in sensor networks. However, in the presence of noise, it is impossible to gain the accurate distance based on received signal strength indicator. In this article, we propose a new tracking scheme based on received signal strength difference, which is the difference value of received signal strength indicators between two neighboring sampling steps. Supposing the noise has a certain degree of correlation in a certain time interval, received signal strength difference can effectively reduce the negative impact from noise. The tracking algorithm based on received signal strength difference is built: The sensor nodes collectively estimate a possible zone of the target via the signs of received signal strength difference. Next, the possible zone is further immensely shrunk to the refined zone via the absolute values of received signal strength difference. Finally, we determine the target’s final location by choosing the reference dot with the minimum norm in the refined zone . The simulation results demonstrate that the proposed tracking method achieves higher localization accuracy than the typical received signal strength indicator–based scheme. The received signal strength difference–based method also has good generality and robustness with respect to the noises with different deviation values and the target following arbitrarily state model.

Indoor localization is a significant research area in wireless sensor networks (WSNs). Generally, the nodes of WSNs are deployed in the same plane, i.e., the floor, as the target to be positioned, which causes the sensing signal to be influenced or even blocked by unpredictable obstacles, like furniture. However, a 3D system, like Cricket, can reduce the negative impact of obstacles to the maximum extent and guarantee the sensing signal transmission by using the line of sight (LOS). However, most of the traditional localization methods are not available for the new deployment mode. In this paper, we propose the self-localization of beacons method based on the Cayley–Menger determinant, which can determine the positions of beacons stuck in the ceiling; and differential sensitivity analysis (DSA) is also applied to eliminate measurement errors in measurement data fusion. Then, the calibration of beacons scheme is proposed to further refine the locations of beacons by the mobile robot. According to the robot’s motion model based on dead reckoning, which is the process of determining one’s current position, we employ the H ∞ filter and the strong tracking filter (STF) to calibrate the rough locations, respectively. Lastly, the optimal node selection scheme based on geometric dilution precision (GDOP) is presented here, which is able to pick the group of beacons with the minimum GDOP from all of the beacons. Then, we propose the GDOP-based weighting estimation method (GWEM) to associate redundant information with the position of the target. To verify the proposed methods in the paper, we design and conduct a simulation and an experiment in an indoor setting. Compared to EKF and the H ∞ filter, the adopted STF method can more effectively calibrate the locations of beacons; GWEM can provide centimeter-level precision in 3D environments by using the combination of beacons that minimizes GDOP.