With the increase of communication frequency, terahertz (THz) communication technology has been an important research field; particularly the terahertz modulator is becoming one of the core devices ...in THz communication system. The modulation performance of a THz communication system depends on the characterization of THz modulator. THz modulators based on different principles and materials have been studied and developed. However, they are still on the way to practical application due to low modulation speed, narrow bandwidth, and insufficient modulation depth. Therefore, we review the research progress of THz modulator in recent years and evaluate devices critically and comprehensively. We focus on the working principles such as electric, optical, optoelectrical, thermal, magnetic, programmable metamaterials and nonlinear modulation methods for THz wave with semiconductors, metamaterials, and 2D materials (such as graphene, molybdenum disulfide, and tungsten disulfide). Furthermore, we propose a guiding rule to select appropriate materials and modulation methods for specific applications in THz communication.
The effects of the macroscopic surface morphology caused by the uneven wear on friction induced vibration were investigated. The experimental results showed the uneven wear in the sliding direction ...produced the contact plateaus with large theoretical contact lengths at the leading edge and increased the unstable vibrations. A numerical analysis of the contact pressure distribution in different macroscopic surface morphology indicated variation of contact pressure deteriorated the wear status, thus increased the tendency of unstable vibration. And the stability of the friction system decreased with the changes in the macroscopic surface morphology. The lumped parameter model proved the uneven wear in the sliding direction would decrease the stability of the system and increase the coupling of tangential and normal vibration.
•Effect of surface morphology on evolution of friction induced vibration is studied.•The change of surface morphology show relation with the surface contact plateaus.•Numerical analysis simulated wear and dynamic contact pressure of friction surface.•The surface morphology caused by uneven wear decreases the stability of friction system.
Abstract We present the first catalog of very-high-energy and ultra-high-energy gamma-ray sources detected by the Large High Altitude Air Shower Observatory. The catalog was compiled using 508 days ...of data collected by the Water Cherenkov Detector Array from 2021 March to 2022 September and 933 days of data recorded by the Kilometer Squared Array from 2020 January to 2022 September. This catalog represents the main result from the most sensitive large coverage gamma-ray survey of the sky above 1 TeV, covering decl. from −20° to 80°. In total, the catalog contains 90 sources with an extended size smaller than 2° and a significance of detection at >5 σ . Based on our source association criteria, 32 new TeV sources are proposed in this study. Among the 90 sources, 43 sources are detected with ultra-high energy ( E > 100 TeV) emission at >4 σ significance level. We provide the position, extension, and spectral characteristics of all the sources in this catalog.
External controlling the phase transition behavior of vanadium dioxide is important to realize its practical applications as energy-efficient electronic devices. Because of its relatively high phase ...transition temperature of 68 °C, the central challenge for VO2-based electronics, lies in finding an energy efficient way, to modulate the phase transition in a reversible and reproducible manner. In this work, we report an experimental realization of p–n heterojunctions by growing VO2 film on p-type GaN substrate. By adding the bias voltage on the p–n junction, the metal–insulator transition behavior of VO2 film can be changed continuously. It is demonstrated that the phase transition of VO2 film is closely associated with the carrier distribution within the space charge region, which can be directly controlled by the bias voltage. Our findings offer novel opportunities for modulating the phase transition of VO2 film in a reversible way as well as extending the concept of electric-field modulation on other phase transition materials.
The meat quality of chicken is an important factor affecting the consumer’s health. It was hypothesized that n-3 polyunsaturated fatty acid (n-3 PUFA) could be effectively deposited in chicken, by ...incorporating antioxidation of soybean isoflavone (SI), which led to improved quality of chicken meat for good health of human beings. Effects of partial or complete dietary substitution of lard (LA) with linseed oil (LO), with or without SI on growth performance, biochemical indicators, meat quality, fatty acid profiles, lipid-related health indicators and gene expression of breast muscle were examined in chickens. A total of 900 males were fed a corn–soybean meal diet supplemented with 4% LA, 2% LA + 2% LO and 4% LO and the latter two including 30 mg SI/kg (2% LA + 2% LO + SI and 4% LO + SI) from 29 to 66 days of age; each of the five dietary treatments included six replicates of 30 birds. Compared with the 4% LA diet, dietary 4% LO significantly increased the feed efficiency and had no negative effect on objective indices related to meat quality; LO significantly decreased plasma triglycerides and total cholesterol (TCH); abdominal fat percentage was significantly decreased in birds fed the 4% LO and 4% LO + SI diets. Chickens with LO diets resulted in higher contents of α-linolenic acid (C18:3n-3), EPA (C20:5n-3) and total n-3 PUFA, together with a lower content of palmitic acid (C16:0), lignoceric acid (C24:0), saturated fatty acids and n-6:n-3 ratio in breast muscle compared to 4% LA diet (P < 0.05); they also significantly decreased atherogenic index, thrombogenic index and increased the hypocholesterolemic to hypercholesterolemic ratio. Adding SI to the LO diets enhanced the contents of EPA and DHA (C22:6n-3), plasma total superoxide dismutase, reduced glutathione (GSH)/oxidized glutathione and muscle GSH content, while decreased plasma total triglyceride and TCH and malondialdehyde content in plasma and breast muscle compared to its absence (P < 0.05). Expression in breast muscle of fatty acid desaturase 1 (FADS1), FADS2, elongase 2 (ELOVL2) and ELOVL5 genes were significantly higher with the LO diets including SI than with the 4% LA diet. Significant interactions existed between LO level and inclusion of SI on EPA and TCH contents. These findings indicate that diet supplemented with LO combined with SI is an effective alternative when optimizing the nutritional value of chicken meat for human consumers.
Abstract
Objectives
To compare the short-term outcomes of unilateral biportal endoscopic lumbar interbody fusion (BLIF) and uniportal endoscopic lumbar interbody fusion (ULIF).
Methods
Sixty patients ...diagnosed with L4/5 spinal stenosis who underwent BLIF and ULIF were included (30 in each group). Clinical evaluation was performed preoperatively and postoperatively in the 1st week, 1st month, and 1st year. Factors such as the visual analogue score (VAS), Oswestry Disability Index (ODI), operative time, surgical complications, and radiological outcomes (fusion rate, screw loosening, and cage subsidence) were compared between the two groups.
Results
All patients showed improved mean VAS and ODI at all three postoperative follow-ups, and no statistically significant differences were detected between the BLIF and ULIF groups. The mean operative time in the BLIF group was shorter than that in the ULIF group. Nerve root injury occurred in two patients in the BLIF group, while leakage of cerebrospinal fluid occurred in one patient in the ULIF group. All adverse events were treated adequately prior to discharge. The fusion rates with definite and probable grades were significantly higher in the BLIF group than that in the ULIF group. One case of cage subsidence with no screw loosening occurred in each group.
Conclusion
Both BLIF and ULIF are safe and effective surgical techniques. Compared with ULIF, BLIF has the advantages of shorter operative time and a higher fusion rate. Other merits of BLIF include a wider surgical field, greater maneuverability of instruments, visibility during cage implantation, and transverse orientation of the cage.
Summary
Porcine deltacoronavirus (PDCoV) is a recently identified coronavirus in the genus Deltacoronavirus that can cause enteric disease with clinical signs including diarrhoea, vomiting, ...dehydration and mortality in neonatal piglets. Although evidence of the prevalence of PDCoV in China is accumulating, little published information about Chinese PDCoV isolates is available. In this study, we investigated the presence of PDCoV in 49 faecal/intestinal samples from piglets with diarrhoea on different farms in Hebei province. Five samples (10.2%) were positive for PDCoV, but no coinfection of PDCoV with other enteropathogens was observed. A PDCoV strain named HB‐BD was successfully isolated from the intestinal contents of a diarrhoeic piglet and serially propagated in swine testicular (ST) cells for >40 passages. The complete genome of the HB‐BD strain was sequenced and analysed. Genomic analysis showed that the HB‐BD strain had a closer relationship with Chinese strains than those from other countries and was grouped within the Chinese PDCoV cluster. The results of this study will be valuable for further research of PDCoV genetic evolution and development of effective diagnostic reagents, assays and potential vaccines against newly emerged PDCoV strains.
Summary
The purpose of this study was to investigate the effects of long‐term treatment with dexamethasone (DEX) on the antioxidation and nutrition metabolism in broiler chickens. Broilers were ...placed on a high‐nutrient diet for 41 days, and half were given orally DEX‐supplemented water at 20 mg/L every other day from 19 to 41 days of age. DEX treatment downregulated superoxide dismutase activity as well as the mRNA expression of CuZn‐superoxide dismutase and glutathione peroxidase with a decrease in GSH/GSSG ratio and an increase in malondialdehyde level in the liver of broilers. DEX treatment aggravated oxidative damage in the liver and, therefore, increased the sensitivity of broilers to ascites syndrome with higher mortality and reduced growth performance. Serum metabolomics analysis showed that DEX treatment significantly increased the levels of glucose, intermediates in protein metabolism (valine, proline, serine, threonine and urea) and lipid metabolism‐related products (palmitic acid, stearic acid and cholesterol) while decreasing the levels of β‐hydroxy butyric acid, succinic acid and malic acid, demonstrating that DEX treatment inhibited the Krebs cycle and the oxidation of fatty acids, and promoted the de novo synthesis of fatty acids as well as protein decomposition in the liver of broilers. Additionally, detection of metabolism‐related enzymes revealed that DEX treatment inhibited glycolysis and promoted glycogen decomposition. In summary, DEX treatment resulted in oxidative stress and glucose and lipid metabolism disorders in the broilers.
Plants are constantly threatened by adverse environments including heat stress which can significantly decrease crop yield. Trehalose involvement in plant resistance to heat stress has been reported, ...but the mechanisms of trehalose-induced plant resistance are unclear. In this study, the role of trehalose in enhancing heat—stressed maize (
Zea mays
L.) light reaction of photosynthesis was investigated. We observed that exogenously supplied trehalose accelerated photosynthetic electron transport in heat-stressed leaves. We further found that exogenously supplied trehalose under heat stress conditions greatly improved the values of actual photosystem II (PSII) efficiency
Y
(II)
and the photochemical quenching coefficient (
qP
) and accelerated the rate of photosynthetic electron transport from pheophytin (Pheo) to Q
A
to Q
B
in PSII. In addition, exogenously supplied trehalose elevated the rate of cyclic electron flow (CEF), the xanthophyll cycle, ATPase activities, the osmotic component of the trans-thylakoid proton motive force and size of the plastoquinone (PQ) pool and reduced photosystem I (PSI)donor-side limitation. We conclude that exogenously supplied trehalose improves electron transport from Pheo to Q
A
and Q
A
to Q
B
by protecting the oxygen-evolving complex and the PSII reaction center, thereby improving the values of Y(II) and
qP
during heat stress. Our study reveals a good technological method to improve photosynthetic electron transport in maize under changing climatic conditions like heat.
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