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Due to their outstanding properties, bamboo-based fiber composites are gaining significant traction in the fields of construction and decoration. Among the crucial process steps in their production, hot pressing stands out as a pivotal one. Temperature, being a key parameter in hot pressing, and its stability of control exert a profound impact on the finished mechanical properties and associated indices of bamboo-based fiber composites. In this investigation, we introduce an active disturbance rejection control (ADRC) methodology specifically tailored for the hot-pressing temperature of bamboo-based fiber composites. A mathematical model encompassing the motor, steam regulating valve, and, ultimately, the hot-pressing temperature is formulated, with the transfer functions at each level being precisely determined through parameter identification techniques. The simulation outcomes reveal that in the absence of signal interference, sinusoidal signal interference, or random signal interference, the ADRC method outperforms the traditional PID algorithm in the realm of hot-pressing temperature control for bamboo-based fiber composites. This approach effectively reduces the temperature fluctuations of the PID algorithm, thereby averting issues such as premature curing or board bursting. In summary, this study holds significant implications for enhancing the mechanical properties of bamboo-based fiber composites. [ABSTRACT FROM AUTHOR]

Bamboo-based fiber composites, known as recombinant bamboo, have emerged as a new material in the construction and decoration industry. With its excellent mechanical and ornamental properties, recombinant bamboo is gaining popularity. However, its high hardness and abrasion resistance pose challenges in the milling process. To address this, we conducted an experimental study to investigate the milling machinability of recombinant bamboo. We studied the impact of various factors—fiber angle, feed rate, and spindle speed—on the tangential and normal roughness of milled surfaces. Our findings indicated that increasing the spindle speed within an acceptable range can effectively mitigate issues such as carbonization and endface cracking on a milled surface. Additionally, we developed a prediction model to assess the probability of end splitting in recombinant bamboo. This research aimed to enhance the milling quality of recombinant bamboo, improve control over surface roughness, reduce the likelihood of end splitting, and, ultimately, expand application possibilities. [ABSTRACT FROM AUTHOR]

Bamboo-based fiber composite panel is a new type of composite material with excellent performance. When processing bamboo-based fiber composite panels, the dynamic stability of the circular saw blade affects the surface quality of the product and the life of the machinery and equipment. Sawing heat and vibration characteristics can significantly affect the dynamic stability of circular saw blades. Circular saw blade temperature and vibration characteristics are affected by the processing parameters, and the circular saw blade temperature and vibration characteristics are analyzed by changing the processing parameters. Adopting the thermoset coupling model can be used to analyze the change rule of circular saw blade temperature when sawing bamboo-based fiber composite boards, and at the same time to analyze the change rule of circular saw blade temperature, vibration speed, and vibration acceleration through the use of by CCD experiments. The regression equations for circular saw blade temperature, vibration velocity, and vibration acceleration were derived through the use of ANOVA and significance analysis. The thermoset coupling model predictions agree with the experimental results, and the density of the isotherms is progressively thinner as the temperature is conducted from the serrated region to the body of the saw. Finally, the accuracy of the regression equations for circular saw blade temperature, vibration velocity, and vibration acceleration was checked via error analysis. The temperature change regression equation has the highest fitting accuracy, with an average error of only 1.37%; the vibration velocity and vibration acceleration regression equations have poorer fitting accuracy, with an average error of 9.5% and 11.45%, respectively, but all of them have sufficient accuracy to predict the dynamic stability of circular saw blades. The results of the study can provide some guidance for the innovative design of circular saw blades. [ABSTRACT FROM AUTHOR]

The surface roughness of wood has a great influence on its performance and is a very important indicator in processing and manufacturing. In this paper, we use the central composite design experiment (CCD experiment) and artificial neural network (ANN) model to study the changing pattern of surface roughness during the high-speed milling process of pine wood. In the CCD experiments, the spindle speed, feed speed, and depth of cut are used as the influencing factors, and the surface roughness is used as the index to analyze the variation law and fit the surface roughness parameter equation. By measuring the chip size in each group in the CCD experiment, the ANN model is used to predict the surface roughness under this machining parameter by measuring the chip size in each test group. The experimental results showed that the mean error of the surface roughness prediction values in the CCD experiment (12.2%) was larger than that of the ANN model (7.8%), and the mean squared error (MSE) of the ANN model was 0.025, the mean absolute percentage error(MAPE) was 0.01, and the coefficient of determination R2 was 0.95. Compared with the CCD experiment, the ANN model had a higher prediction accuracy. The results of this paper can provide some guidance for the prediction of surface roughness during wood processing. [ABSTRACT FROM AUTHOR]

Background and aims: Amino acids (AAs) not only constitute milk protein but also stimulate milk synthesis through the activation of mTORC1 signaling, but which amino acids that have the greatest impact on milk fat and protein synthesis is still very limited. In this study, we aimed to identify the most critical AAs involved in the regulation of milk synthesis and clarify how these AAs regulate milk synthesis through the G-protein-coupled receptors (GPCRs) signaling pathway. Methods: In this study, a mouse mammary epithelial cell line (HC11) and porcine mammary epithelial cells (PMECs) were selected as study subjects. After treatment with different AAs, the amount of milk protein and milk fat synthesis were detected. Activation of mTORC1 and GPCRs signaling induced by AAs was also investigated. Results: In this study, we demonstrate that essential amino acids (EAAs) are crucial to promote lactation by increasing the expression of genes and proteins related to milk synthesis, such as ACACA, FABP4, DGAT1, SREBP1, α-casein, β-casein, and WAP in HC11 cells and PMECs. In addition to activating mTORC1, EAAs uniquely regulate the expression of calcium-sensing receptor (CaSR) among all amino-acid-responsive GPCRs, which indicates a potential link between CaSR and the mTORC1 pathway in mammary gland epithelial cells. Compared with other EAAs, leucine and arginine had the greatest capacity to trigger GPCRs (p-ERK) and mTORC1 (p-S6K1) signaling in HC11 cells. In addition, CaSR and its downstream G proteins Gi, Gq, and Gβγ are involved in the regulation of leucine- and arginine-induced milk synthesis and mTORC1 activation. Taken together, our data suggest that leucine and arginine can efficiently trigger milk synthesis through the CaSR/Gi/mTORC1 and CaSR/Gq/mTORC1 pathways. Conclusion: We found that the G-protein-coupled receptor CaSR is an important amino acid sensor in mammary epithelial cells. Leucine and arginine promote milk synthesis partially through the CaSR/Gi/mTORC1 and CaSR/Gq/mTORC1 signaling systems in mammary gland epithelial cells. Although this mechanism needs further verification, it is foreseeable that this mechanism may provide new insights into the regulation of milk synthesis. [ABSTRACT FROM AUTHOR]

Alpine grasslands are undergoing severe degradation and are mainly restored through fencing. Numerous studies have explored the patterns, processes, and mechanisms of plant and soil during degradation, but few have been conducted on nitrogen (N) uptake by plant functional groups during restoration. An alpine meadow and an alpine steppe on the Tibetan Plateau were chosen to carry out in situ15N labelling experiments in the forms of NH4+, NO3−, and glycine during restoration. Short‐, moderate‐, and long‐term restoration periods were explored, and plants were classified by functional groups into grasses, sedges, and forbs. Our results found biomass of grasses increased and that of sedges decreased with restoration in alpine meadow. In alpine steppe, forbs gradually became dominant in the community biomass by 58% during restoration. Long‐term restoration increased NH4+ uptake by grasses in alpine meadow. The total N uptake rates by grasses increased, but by forbs decreased during restoration in alpine meadow. Restoration decreased the total N uptake rates of grasses and forbs in alpine steppe. Chemical niche in N uptake was discovered during long‐term restoration in alpine meadow and during moderate‐term restoration in alpine steppe. We conclude that restoration alters the biomass composition of grasses, sedges, and forbs in alpine grasslands and shifts N uptake partitions. Chemical niche in N uptake by different functional groups in grasslands during restoration can decrease the fierce competition for N. Our results provide a synthesis for plant N utilization from soil during restoration of degraded grasslands from the perspective of shifting N uptake strategies. [ABSTRACT FROM AUTHOR]

As one typical heterogeneous material, the heterogeneity of rock micro parameters has an important effect on its macro mechanical behavior. The study of the heterogeneity of micro parameters is more important to reveal the root cause of deformation and failure. However, as a typical heterogeneous material, the current testing and inversion method is not suitable for micro parameters measurement for the rock. Aiming at obtaining the distribution of micro Young's modulus and micro Poisson's ratio of the rock, based on the digital image correlation method (DIC) and finite element method (FEM), this paper proposed a parameter field inversion method, namely the DF-PF inversion method. Its inversion accuracy is verified using numerical simulation and laboratory uniaxial compression test. Considering the influences of heterogeneity, stress state and dimension difference, the average inversion error of Young's modulus field and Poisson's ratio field are below 10%, and the proportion of elements with an error of less than 15% accounts for more than 86% in the whole specimen model. Compared with the conventional measuring method, the error of macro Young's modulus and macro Poisson's ratio calculated by the DF-PF inversion method is less than 2.8% and 9.07%, respectively. Based on the statistical analysis of Young's modulus field and Poisson's ratio field, the parameter homogeneity and quantitative function relation between the micro parameter and the principal strain can also be obtained in laboratory tests. The DF-PF inversion method provides a new effective method of testing Young's modulus field and Poisson's ratio field of the rocks under complex stress states. [ABSTRACT FROM AUTHOR]

The study was designed to prepare and evaluate chitosan stabilized-albumin nanoparticles as NELL-1 protein carriers(Chi/NNPs). The Chi/NNPs were prepared by desolvation method and then stabilized by chitosan through electrostatic interaction. The Chi/NNPs were characterized for drug loading efficiency, surface morphology, particle size, surface charge. Fluorescein isothiocyanate-labeled chitosan was used to confirm the homogeneity of chitosan coating on the BSA nanoparticles. The NELL-1 bioactivity of Chi/NNPs and the release kinetics were investigated in vitro. It was observed that the mean particle size with chitosan (0.075 wt%,0.15 wt%, 0.3 wt%, respectively) and the surface charge were 368.663 ± 15.470 nm, 382.881 ± 18.767 nm, 390.480 ± 11.465 nm and +25.03 ± 1.42 mV, +30.27 ± 1.80 mV, +31.03 ± 2.05 mV respectively. Drug entrapment efficiency ranged from 87.83% to 89.30%. The Chi/NNPs prepared with the 0.15 wt% chitosan were able to successfully control the release of NELL-1 and maintain a sustained release for up to 8 days. Furthermore, more than 82.67 ± 8.74% of the loaded protein’s bioactivity was preserved in Chi/NNPs over the period of the investigation. Our findings suggest that Chi/NNPs as promising protein delivery nanocarriers have the ability to maintain sustained release kinetics and to preserve the bioactivity of released NELL-1. [ABSTRACT FROM AUTHOR]

Objective: To explore the relationship between G protein-coupled estrogen receptor (GPER) and hypertension in post-menopausal women. Methods: Using a matched case-control design, clinical and laboratory data were collected. Conditional logistic regression with stratified analysis was conducted to identify the association between GPER and hypertension. Results: The GPER level was significantly lower in the case group than in the control group (126.3 ± 21.6 vs. 133.6 ± 27.3, P=0.000). The GPER levels of the hypertension cases with and those without menopause were significant (120.5 ± 11.8 and 127.2 ± 12.1, P=0.000). No significant difference in the GPER level between the controls with and those without menopause was observed (P=0.241). Logistic regression revealed that the GPER quartile was related to hypertension (odds ratio [OR]: 0.63, 95% confidence interval [CI]: 0.13–0.93, P=0.018) after adjusting for potential confounding factors. Stratified analysis revealed that the GPER quartile was not associated with hypertension in premenopausal women, and the fourth GPER quartile showed a predictive association with hypertension (OR: 0.43, 95% CI: 0.29–0.90) in menopausal women. Conclusions: GPER level is associated with hypertension and is a protective factor for hypertension in menopausal women but not premenopausal women. Further research is required due to study limitations. [ABSTRACT FROM AUTHOR]

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In the present work, a one-step synthetic route is developed for fabricating hierarchical anatase TiO2 microspheres for the first time. These microspheres are composed of ultrathin rod-like structures in the radial direction, in which ultrathin rods consisted of tiny octahedra via a growth model of oriented attachment. Based on XRD and electron microscopic analyses, a mechanism for the growth of the microspheres is proposed. This material displays a large capacity of 157.3 mA h g−1 at 1 C after 200 cycles and also exhibits high rate performance and excellent cycling stability. These high performance characteristics may be due to the intrinsic characteristics of the hierarchical porous anatase TiO2 microspheres, in which the porous structure can permit facile diffusion of the electrolyte. They can also enhance the contact between the electrode surface and the electrolyte, while the ultrathin rods can shorten the transport distance of Li-ions and electrons during electrochemical cycling. At the same, the porous microsphere can also accommodate volume changes in the charge–discharge process. [ABSTRACT FROM AUTHOR]

This communication presents a novel compact planar monopole antenna configuration: the spirograph planar monopole antenna (SPMA) covering C-/X-Band (4–12 GHz). The antenna has an invariant omnidirectional radiation pattern across the frequency band with no multi-lobe effect and low cross-polarization. The SPMA radiating element size is less than \lambda /2 at the highest frequency of operation such that it can be used as a beam scanning array element. For the SPMA, it was found that increasing the number of points in the antenna shape miniaturizes the radiating element and increases the impedance bandwidth. A prototype SPMA was fabricated and measured for impedance and radiation performance. [ABSTRACT FROM PUBLISHER]

Microstrip patch antenna with multi-frequency and dual-mode is presented in this communication. The introduction of metamaterial substrate made of modified mushroom-type electromagnetic band-gap (EBG) structure enables the multi- functions. The composite right/left-handed transmission line (CRLH TL) theory and multi-conductor transmission line (MTL) theory are introduced to analyze and design this kind of antenna. Three modes including one monopolar radiation pattern in the n=0 mode and two patch-like radiation patterns in the n=-1, 1 modes respectively are analyzed and can be tuned by the parameters of the EBG structure. Since geometry of the radiating patch does not affect the infinite wavelength mode, circular polarization (CP) is obtained for the n=+1 mode by truncating the square radiating patch with linear polarization (LP) for the n=0 mode staying unchanged. Thus dual polarized antenna is obtained. Two prototypes of probe-fed patch antennas are fabricated to verify the theory analysis. [ABSTRACT FROM PUBLISHER]

A novel broadband high gain periodic endfire antenna is presented. Broad bandwidth is realized by using a parallel strip line (PSL) feed and bowtie dipole elements while gain enhancement is achieved by loading split-ring resonator (SRR) structure in the endfire direction. The measurements show that SRR-loaded antenna presents gain of about 6.2~9.9 dB in the whole working band (5.1~8.2 GHz), which is about 1.3~4.2 dB more than the unloaded one. This antenna can be used in wireless communication systems for its advantages of broad bandwidth and high gain. [ABSTRACT FROM PUBLISHER]