In this paper, a multilayer ultra-wideband transparent metamaterial wave absorber is proposed, which has the characteristics of ultra-wideband wave absorption, light transmission and flexible ...bending; in addition, due to the complete symmetry of the structure, the absorber has polarization insensitivity to incident electromagnetic waves. Both simulation and experimental results show that the frequency range of the microwave absorption rate is higher than 90% between 8.7 GHz and 38.9 GHz (between which most of the absorption rate can reach more than 95%), the total bandwidth is 30.2 GHz, and the relative bandwidth is 126.9%, realizing microwave broadband absorption and covering commonly used communication frequency bands such as X-band, Ku-band, and K-band. A sample was processed and tested. The test results are in good agreement with the results of the theoretical analysis, which proves the correctness of the theoretical analysis. In addition, through the selection and oxidation of indium tin (ITO) materials, the metamaterial also has the characteristics of optical transparency and flexibility, so it has potential application value in the window radar stealth and conformal radar stealth of weapons and equipment.
In order to study the effects and mechanism of florfenicol (FFC) on the kidney function of broilers, 180 1-day-old broilers were randomly divided into 6 groups, 30 in each group. Except for the ...control group, different doses of FFC were added to drinking water in the other 5 groups (0.15 g/L, 0.3 g/L, 0.6 g/L, 1.2 g/L and 1.8 g/L). After continuous administration for 5 days, renal histopathological changes, serum renal function indicators, renal peroxidation products and antioxidant factors, and apoptotic factors were detected in broilers aged 21 and 42 days. The results showed that compared with the control group, the kidney tissue structure was disordered, the glomerulus was atrophic, the cystic cavity was enlarged, and the epithelial cells of renal tubules were seriously vacuolated in broilers of treatment groups. And with the growth of broilers, the kidney injury of broilers in the low-dose FFC group was relieved. FFC significantly increased the contents of uric acid (UA), blood urea nitrogen (BUN), creatinine (CRE) in serum and malondialdehyde (MDA) in kidney of broilers, but significantly reduced the levels of glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) in kidney. FFC significantly inhibited the mRNA relative transcriptional levels of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and nicotinamide adenine dinucleotide phosphate: quinone oxidoreductase-1 (NQO-1), and increased the mRNA and protein expression levels of p53, Caspase-3 and Caspase-6 in kidney tissue of broilers. It is concluded that FFC has certain nephrotoxicity to broilers, and its effect on kidney is dose-dependent and reversible. FFC causes intense lipid peroxidation in broiler kidney by inhibiting the expression of related factors in the downstream signal pathway of Nrf2. FFC can also up-regulate the expression of pro-apoptotic factors and accelerate the abnormal apoptosis of renal cells, thus seriously affecting the renal function of broilers.
•Broiler kidney taking florfenicol orally were unable to excrete uric acid, blood urea nitrogen and creatinine normally.•Florfenicol causes intense lipid peroxidation in broiler renal cells.•Florfenicol could down regulate the mRNA expression levels of Nrf2 and its downstream key factors.•Florfenicol induced abnormal apoptosis of broiler renal cells by up regulating the expression of pro-apoptotic factors.•Florfenicol causes kidney damage in broilers by promoting cell necrosis and abnormal apoptosis.
Road detection plays key roles for remote sensing image analytics. Hough transform (HT) is one very typical method for road detection, especially for straight line road detection. Although many ...variants of Hough transform have been reported, it is still a great challenge to develop a low computational complexity and time-saving Hough transform algorithm. In this paper, we propose a generalized Hough transform (i.e., Radon transform) implementation for road detection in remote sensing images. Specifically, we present a dictionary learning method to approximate the Radon transform. The proposed approximation method treats a Radon transform as a linear transform, which then facilitates parallel implementation of the Radon transform for multiple images. To evaluate the proposed algorithm, we conduct extensive experiments on the popular RSSCN7 database for straight road detection. The experimental results demonstrate that our method is superior to the traditional algorithms in terms of accuracy and computing complexity.
The extensively studied cAMP-dependent protein kinase A (PKA) is involved in the regulation of critical cell processes, including metabolism, gene expression, and cell proliferation. Therefore, PKA ...has been viewed increasingly as potential target for variety of drugs and environmental endocrine disruptors. Consequentially, the preparation of PKA protein became an important initial step for the subsequent exploration of PKA’s character in endocrine disrupting effects of pesticides. To investigate PKA protein, which is potential to be the environmental endocrine toxicity target of triazole fungicides, a strategy to heterologously express protein kinase A catalytic alpha subunit of human (hPKAcα) and zebrafish (zPKAcα) in Escherichia coli (E. coli) BL21(DE3) host cells was demonstrated. After optimizing conditions and protein purification, we successfully obtained enzymatically active hPKAcα and zPKAcα. Western blot analysis indicated that the recombinant hPKAcα and zPKAcα still retained their characteristic antigenicity and binding activity, while in vitro kinase activity assays revealed that the recombinant hPKAcα and zPKAcα maintained enzyme activity. By in silico methods including homology modelling and molecular docking, the affinity of ligands and the models of hPKAcα and zPKAcα were further tested. The present study offered a valuable method to achieve the prokaryotic expression of a eukaryotic protein kinase and laid a foundation to facilitate further investigation of toxicological target of triazole pesticides.
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•The optimal conditions to express and purify PKAcα of human and zebrafish.•The antigenicity of recombinant proteins was demonstrated by Western blot.•The active phosphorylation was revealed by in vitro activity assay.•Homology modelling and molecular docking showed detailed interaction information.
The Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ) is a self-report tool widely used to assess individuals' level of reinforcement sensitivity. Drug addiction is strongly ...associated with reinforcement sensitivity, but there is a lack of measurement tools to assess reinforcement sensitivity in drug users, necessitating the revision and application of the SPSRQ among drug users. This study recruited 819 drug users (mean age = 34.74; 56.41% female) from five compulsory rehabilitation centers in Hunan Province, China. The applicability of the SPSRQ among person with substance use disorder was assessed by conducting reliability analyses and validity analyses, with retesting performed by 127 individuals after 6 weeks. Exploratory factor analysis for the SPSRQ showed a stable two-factor structure in person with substance use disorder. Confirmatory factor analysis indicated acceptable goodness of fit indexes for the two-factor structure. The SPSRQ also demonstrated good reliability and convergent and discriminant validity evidence. The two-factor structure of the SPSRQ also demonstrated measurement invariance across gender. Further comparative analysis found that the degree of reward sensitivity was higher for males than for females. Generally, the SPSRQ has shown evidence of good reliability and validity in Chinese drug-dependent populations, and it is suitable for research and application with Chinese person with substance use disorder. These findings about the personality traits of people with substance use disorder provide a solid basis for further research.
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•Aerogel scaffolds with adjustable macro/micro-pore structure were prepared for tissue engineering by combining 3D printing with sacrificial template method.•3D printing allows ...manufacturing macroscale porous scaffold samples.•Sacrificial template method allows controlling the microstructure of aerogel scaffolds.•L929 fibroblast cell showed high cell viability and well proliferation after seeding, demonstrating that the aerogel scaffolds are suitable for tissue engineering.
Aerogel is a kind of promising biomaterial to prepare scaffolds used in tissue engineering due to the characteristics of high water uptake, interconnected porous structure, and excellent permeability. However, the process to adjust the macro/micro-pore structure which affect nutrient diffusion and cell adhesion of the aerogel scaffolds is still challenging. In this study, combining 3D printing with sacrificial template method aiming to fabricate aerogel scaffolds with adjustable macro/micro-pore structure for tissue engineering was explored. A mixture of poly (ethylene glycol) diacrylate (PEGDA), Pluronic F127, and Lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) was used as aerogel scaffold materials. The rheological results indicated that PEGDA-Pluronic F127 hydrogel precursors possessed shear thinning and shear recovery behaviors and were suitable for 3D printing. After removing the sacrificial material of Pluronic F127, the aerogel scaffolds displayed larger micro-pore structure compared to no removing group and still maintained sufficient mechanical strength. Furthermore, the L929 fibroblast cell showed high cell viability and well proliferation performance after culturing 7 days on aerogel scaffolds fabricated by 3D printing. All these results suggest that the aerogel scaffolds with adjustable macro/micro-pore structure exhibit good mechanical and biological properties, which are expected to be used in tissue engineering.
Edwardsiella tarda and Vibrio harveyi are the main pathogens causing ascites in turbot, which severely restricts the development of turbot farming. This study evaluated the effect of feeding phage ...cocktail on the prevention of ascites in turbot. The turbot was challenged by bacterial suspension comprising 50 μL of E. tarda ET9 at a concentration of 5.99 × 106 CFU/fish and 50 μL of V. harveyi VH5 at a concentration of 7.86 × 107 CFU/fish after they were fed with phage cocktails for 7 days. The cumulative survival rate of negative control group was 100%, and that of positive control group decreased to 7%, while that of phage-treated group was 60%, 83% and 87% when multiplicity of infection (MOI) was equal to 1, 10 and 100 respectively after 15 days of challenge. The pathological section showed that only the liver and intestines of turbot in the positive control group had lesions, while that of the phage-treated group had no obvious symptom. The contents of white blood cells, red blood cell distribution width and platelets in the blood of the positive control group were significantly higher than those of the negative control group and the phage-treated group (P < 0.05). In contrast, there was no significant difference between the negative control group and the phage-treated group (P > 0.05). Only the levels of Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Total protein (TP), Globulin (GLO), Total bile acid (TBA), Cholinesterase (CHE), Creatinine (CREA), Uric acid (UA), Glucose (GLU), Total cholesterol (CHOL), Low density lipoprotein (LDL), Creatine kinase (CK) and Creatine kinase isoenzymes (CKMB) in the serum of turbot in the positive control group were significantly different from those in the negative control group and the phage-treated group (P < 0.05), but there was no significant difference between the negative control group and the phage-treated group (P > 0.05). The transcription levels of 1L-1β, 1L-8, TNF-α and C 3 in the head kidney and spleen of turbot fed with phage cocktails with MOI = 10 were significantly lower than those of the positive control group after 24 h of challenge (P < 0.05). The intestinal flora of turbot in phage-treated group and positive control group was analyzed by high-throughput sequencing. The results showed that the abundance of Vibrio species and Edwardsiella species in turbot's intestine was significantly reduced by feeding with phage cocktails. These results indicate that feeding phage cocktails can effectively prevent bacterial ascites on turbot.
•Phage cocktails were used as agent for the prevention of turbot ascites.•Phage cocktails reduces inflammatory response in turbot.•Phage cocktails does not disturb the normal bacteria in the turbot intestinal.
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The design of Co-Mn composite oxides catalysts derived from MOF is significant for catalytic combustion of toluene. Here, a series of M-CoaMnbOx, with enhanced catalytic properties ...compared with that of M-Co3O4, were successfully prepared through pyrolysis of Mn-doped Co-MOF. The as-synthesized M-Co1Mn1Ox (Co:Mn = 1:1) exhibits an optimal catalytic activity with 90% toluene conversion reached at 227 °C, which benefits from the increase of Co3+, Oads and the synergistic effect between Mn and Co. According to the analysis of the in situ diffuse reflectance infrared Fourier transform spectroscopy, toluene could be degraded easier on M-Co1Mn1Ox with lower activation energy than M-Co3O4. The main intermediate products are benzaldehyde, benzoic acid, anhydride, and maleate species. Those findings reveal the value of Mn doping for improved activity of toluene oxidation on MOF derived Co3O4, which provide a feasible method for the construction of toluene-oxidation catalysts.
Recent advances on remote sensing techniques allow easier access to imaging spectrometer data. Manually labeling and processing of such collected hyperspectral images (HSIs) with a vast quantities of ...samples and a large number of bands is labor and time consuming. To relieve these manual processes, machine learning based HSI processing methods have attracted increasing research attention. A major assumption in many machine learning problems is that the training and testing data are in the same feature space and follow the same distribution. However, this assumption doesn't always hold true in many real world problems, especially in certain HSI processing problems with extremely insufficient or even without training samples. In this letter, we present a transfer learning framework to address this unsupervised challenge (i.e., without training samples in the target domain), by making the following three main contributions: 1) to the best of our knowledge, this is the first time for transfer learning framework to be used for the classification of totally unknown target HSI data with no training samples; 2) the characteristics of HSI are learned on dual spaces to exploit its structure knowledge to better label HSI samples; and 3) two specific new scenarios suitable for transfer learning are investigated. Experimental results on several real world HSIs support the superiority of the proposed work.
People infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) experience a wide range of clinical manifestations, from asymptomatic and mild illness to severe illness and death, ...influenced by age and a variety of comorbidities. Neutralizing antibodies (nAbs) are thought to be a primary immune defense against the virus. Large, diverse, well-characterized cohorts of convalescent individuals provide standardized values to benchmark nAb responses to past SARS-CoV-2 infection and define potentially protective levels of immunity.
This analysis comprises an observational cohort of 329 HIV-seronegative adults in the United States (n = 167) and Peru (n = 162) convalescing from SARS-CoV-2 infection from May through October 2020. The mean age was 48 years (range 18 to 86), 54% of the cohort overall was Hispanic, and 34% identified as White. nAb titers were measured in serum by SARS-CoV-2.D614G Spike-pseudotyped virus infection of 293T/ACE2 cells. Multiple linear regression was applied to define associations between nAb titers and demographic variables, disease severity and time from infection or disease onset, and comorbidities within and across US and Peruvian cohorts over time. nAb titers peaked 28 to 42 days post-diagnosis and were higher in participants with a history of severe Coronavirus Disease 2019 (COVID-19) (p < 0.001). Diabetes, age >55 years, male sex assigned at birth, and, in some cases, body mass index were also independently associated with higher nAb titers, whereas hypertension was independently associated with lower nAb titers. nAb titers did not differ by race, underlying pulmonary disease or smoking. Two months post-enrollment, nAb ID50 (ID80) titers declined 3.5 (2.8)-fold overall. Study limitations in this observational, convalescent cohort include survivorship bias and missing early viral loads and acute immune responses to correlate with the convalescent responses we observed.
In summary, in our cohort, nAb titers after SARS-CoV-2 infection peaked approximately 1 month post-diagnosis and varied by age, sex assigned at birth, disease severity, and underlying comorbidities. Our data show great heterogeneity in nAb responses among people with recent COVID-19, highlighting the challenges of interpreting natural history studies and gauging responses to vaccines and therapeutics among people with recent infection. Our observations illuminate potential correlations of demographic and clinical characteristics with nAb responses, a key element for protection from COVID-19, thus informing development and implementation of preventative and therapeutic strategies globally.
ClinicalTrials.gov NCT04403880.
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