ABSTRACT
Migratory wild birds can carry various pathogens, such as influenza A virus, which can spread to globally and cause disease outbreaks and epidemics. Continuous epidemiological surveillance of migratory wild birds is of great significance for the early warning, prevention, and control of epidemics. To investigate the pathogen infection status of migratory wild birds in eastern China, fecal samples were collected from wetlands to conduct pathogen surveillance. The results showed that duck orthoreovirus (DRV) and goose parvovirus (GPV) nucleic acid were detected positive in the fecal samples collected from wild ducks, egrets, and swan. Phylogenetic analysis of the amplified viral genes reveals that the isolates were closely related to the prevalent strains in the regions involved in East Asian-Australasian (EAA) migratory flyway. Phylogenetic analysis of the amplified viral genes confirmed that they were closely related to circulating strains in the regions involved in the EAA migration pathway. The findings of this study have expanded the host range of the orthoreovirus and parvovirus, and revealed possible virus transmission between wild migratory birds and poultry.
Subject(s)
Animals, Wild , Bird Diseases , Orthoreovirus, Avian , Parvoviridae Infections , Parvovirus , Phylogeny , Reoviridae Infections , Animals , Reoviridae Infections/veterinary , Reoviridae Infections/epidemiology , Reoviridae Infections/virology , Orthoreovirus, Avian/isolation & purification , Orthoreovirus, Avian/genetics , Parvoviridae Infections/veterinary , Parvoviridae Infections/virology , Parvoviridae Infections/epidemiology , China/epidemiology , Bird Diseases/virology , Bird Diseases/epidemiology , Animals, Wild/virology , Parvovirus/genetics , Parvovirus/isolation & purification , Feces/virology , Disease Reservoirs/veterinary , Disease Reservoirs/virology , Ducks/virology , Anseriformes/virology , Epidemiological Monitoring/veterinaryABSTRACT
2D transition metal dichalcogenides (TMDCs) are considered as promising materials in post-Moore technology. However, the low photoluminescence quantum yields (PLQY) and single carrier polarity due to the inevitable defects during material preparation are great obstacles to their practical applications. Here, an extraordinary defect engineering strategy is reported based on first-principles calculations and realize it experimentally on WS2 monolayers by doping with IIIA atoms. The doped samples with large sizes possess both giant PLQY enhancement and effective carrier polarity modulation. Surprisingly, the high PL emission maintained even after one year under ambient environment. Moreover, the constructed p-n homojunctions shows high rectification ratio (≈2200), ultrafast response times and excellent stability. Meanwhile, the doping strategy is universally applicable to other TMDCs and dopants. This smart defect engineering strategy not only provides a general scheme to eliminate the negative influence of defects, but also utilize them to achieve desired optoelectronic properties for multifunctional applications.
ABSTRACT
The stomach is a vital organ in the human digestive system, and its digestive condition is critical to human health. The physical movement of the stomach during digestion is controlled by the circular and oblique muscles. Existing stomach simulators are unable to realistically reproduce the physical movement of the stomach. Due to the complexity of gastric motility, it is challenging to simulate and sense gastric motility. This paper proposes for the first time a bionic soft robotic stomach (BSRS) with an integrated drive and sensing structure inspired by origami and self-powered sensing technology. This soft stomach (SS) can realistically simulate and sense the movements of various parts of the human stomach in real-time. The contraction force and contraction rate of the BSRS are investigated with different viscosity contents, and the experimental values are similar to the physiological range (maximum contraction force is 3.2 N, and maximum contraction rate is 0.8). This paper provides an experimental basis for the study of gastric digestive medicine and food science by simulating the peristaltic motion of the BSRS according to the human stomach and by combining the triboelectric nanogenerator (TENG) sensing technology to monitor the motion of the BSRS in real-time. This article is protected by copyright. All rights reserved.
ABSTRACT
The natural frequency of traditional velocity sensors such as moving coil geophones limits their measurable low-frequency range, and the damping ratio affects the flatness of the sensor in the amplitude and frequency curves, resulting in variations in sensitivity over the available frequency range. In this paper, the structure and working principle of the geophone are analyzed and its dynamics are modeled. After synthesizing the negative resistance method and zero-pole compensation, two commonly adopted low-frequency extension methods, a method for improving low-frequency response, which is a series filter and a subtraction circuit to increase the damping ratio, is proposed. Applying this method to improve the low-frequency response of the JF-20DX geophone, which has a natural frequency of 10 Hz, results in a flat response to acceleration in the frequency range from 1 to 100 Hz. Both the PSpice simulation and actual measurement show a much lower noise level via the new method. Testing the vibration at 10 Hz, the new method has a 17.52 dB higher signal-to-noise ratio than the traditional zero-pole method. Both theoretical analysis and actual measurement results show that this method has a simple circuit structure, introduces less circuit noise, and has a low-frequency response improvement effect, which provides an approach for the low-frequency extension of moving coil geophones.
ABSTRACT
The development of optoelectronic devices requires breakthroughs in new material systems and novel device mechanisms, and the demand recently changes from the detection of signal intensity and responsivity to the exploration of sensitivity of polarized state information. Two-dimensional (2D) materials are a rich family exhibiting diverse physical and electronic properties for polarization device applications, including anisotropic materials, valleytronic materials, and other hybrid heterostructures. In this review, we first review the polarized-light-dependent physical mechanism in 2D materials, then present detailed descriptions in optical and optoelectronic properties, involving Raman shift, optical absorption, and light emission and functional optoelectronic devices. Finally, a comment is made on future developments and challenges. The plethora of 2D materials and their heterostructures offers the promise of polarization-dependent scientific discovery and optoelectronic device application.
ABSTRACT
BACKGROUND: Down-regulation of mechanistic target of rapamycin (mTOR) activity in myeloid-derived suppressor cells (MDSCs) has been shown to promote inducible nitric oxide (NO) synthase (iNOS) expression and NO production. Importantly, pharmacological inhibition of iNOS blocks MDSCs recruitment in immunological hepatic injury. As bronchial asthma is also an immune disease, whether mTOR could interact with MDSCs via iNOS and NO or not is unclear. OBJECTIVE: The aim of this study was to determine whether mTOR could interact with MDSCs via iNOS and NO in asthma. METHODS: Ovalbumin-induced asthma mouse model was established to perform our investigation, and asthmatic markers were evaluated by hematoxylin and eosin (H&E), immunohistochemistry (IHC), and periodic acid-Schiff (PAS) staining. The levels of iNOS and NO in serum were determined by enzyme linked immunosorbent assay (ELISA). Mice lung tissues were stained with antibodies against phosphorylated (p)-mTOR, and p-p70S6K, and yellow/brown staining was considered as giving a positive signal, meanwhile, the protein levels of p-mTOR, and p-p70S6K were also detected using western blot assay. Mice iNOS activity was determined by radioimmunoassay. RESULTS: Tumor-derived MDSCs in asthmatic mice were regulated by mTOR and iNOS. mTOR pathway activation in asthmatic mice was regulated by iNOS and tumor-derived MDSCs. NO production in asthmatic mice was regulated by mTOR and tumor-extracted MDSCs. Positive correlation of iNOS with mTOR pathway and serum MDSCs was observed. CONCLUSION: The data indicated that rapamycin, an inhibitor of mTOR, blocked iNOS and NO production during asthma onset. Thus, our results revealed potential novel targets for asthma therapy.
ABSTRACT
Myeloid-derived suppressor cells (MDSCs), a group of newly discovered and heterogeneous myeloid-derived immunosuppressive cells, play an important role in the progress of asthma, however, the specific mechanism is still largely unclear. Our previous study has indicated that during the onset of asthma, the accumulation of MDSCs and the level of serum interleukin (IL)-10 increased, while the level of IL-12 decreased. The present study aimed to investigate whether tumor-derived MDSCs could inhibit airway remodeling in asthmatic mice through regulating IL-10 and IL-12 secretion. To perform our investigation, we established a mouse model of breast cancer, and the extracted MDSCs from breast caner mouse model were injected into a mouse model of asthma induced by ovalbumin (OVA). Then, asthmatic airway remodeling of mice was analyzed and the levels of IL-10 and IL-12 in the serum and bronchoalveolar lavage fluid (BALF) of mice were detected. In addition, the correlation of MDSCs with the levels of IL-10 and IL-12 in the transplantation group was analyzed. The transplantation of tumor-derived MDSCs into asthmatic mice significantly improved airway remodeling, decreased MDSCs and the expression of IL-10, and significantly increased the expression of IL-12. Besides, we confirmed that IL-10 was positively correlated with MDSCs, while IL-12 was negatively correlated with MDSCs. The results indicated that tumor-derived MDSCs could reduce IL-10 level, increase the level of IL-12, and thus correct the Th1/Th2 imbalance in asthmatic mice. In summary, our results revealed that tumor-derived MDSCs could serve as a potential novel target for asthma therapy.
ABSTRACT
AIM: Abelmoschi Corolla is a well-known herbal medicine used for the treatment of chronic renal disease. Flavonoids are the major bioactive ingredients of Abelmoschi Corolla, but some non-flavonoid components also exist in this herb. In order to clarify the influences of non-flavonoid components on the pharmacokinetics profile of the flavonoid fraction from Abelmoschi Corolla (FFA), an investigation was carried out to compare the pharmacokinetic parameters of seven flavonoid components after administration of FFA and after administration of FFA combined with different non-flavonoid fractions. MATERIALS AND METHODS: A selective and sensitive UPLC-MS/MS method was established to determine the plasma concentrations of the seven compounds. Sprague-Dawley rats were allocated to four groups which orally administered FFA, FFA combined with macromolecular fraction (FFA-MF), FFA combined with small molecule fraction (FFA-SF) and FFA combined with MF-SF (FFA-MF-SF) with approximately the same dose of FFA. At different time points, the concentration of rutin (1), hyperoside (2), isoquercitrin (3), hibifolin (4), myricetin (5), quercetin-3'-O-glucose (6), quercetin (7) in rat plasma were determined and main pharmacokinetic parameters including T(1/2), T(max), AUC and C(max) were calculated using the DAS 2.0 software package. The statistical analysis was performed using the Student's t-test with P<0.05 as the level of significance. RESULTS: Flavonoids almost had similar pharmacokinetics profile that were rapidly absorbed, reached the peak concentration at 30-60 min in group A, but the pharmacokinetic profiles and parameters of these flavonoids changed when co-administered with non-flavonoid components. It was found that AUC of five flavonoids but not hibifolin and quercetin in group FFA-SF and group FFA-MF-SF increased (P<0.05) in comparison with group FFA while the tendency was not observed in group FFA-MF. Moreover, seven flavonoids had varying degrees of differences in the pharmacokinetics parameters such as C(max), T(max) and T(1/2) (P<0.05) in group FFA-MF, FFA-SF and FFA-MF-SF by comparison with group FFA. CONCLUSION: These results indicate that non-flavonoid components could improve the bioavailability and delay the elimination of some flavonoids in rat.