A triple-band terahertz metamaterial absorber based on buck Dirac semimetals

In this paper, a triple-band terahertz metamaterial absorber (MA) based on buck Dirac semimetals (BDSs) is proposed, which consists of a windmill-shaped element in a square ring layer, a dielectric layer, and a BDSs layer. The MA unit cell is investigated at normal and oblique incidence angle for both transverse electric (TE) and transverse magnetic (TM) polarizations. The simulation results show that the MA has three high absorption peaks at 0.80 THz, 1.72 THz, and 3.38 THz. The corresponding peak absorbance are 99.43%, 99.92% and 99.58%, respectively. Moreover, the absorption peaks of MA can be tuned by adjusting the Fermi energy of the BDSs. And the density of electric field, the magnetic field, and surface current distributions of the MA are given to reveal the absorption mechanism. According to the simulation results, the designed MA not only has high absorbance, but also insensitive to polarizations. Hence it is favorable for various applications, such as terahertz detecting, radar stealth and bio-chemical sensor. Keywords: BDSs, Terahertz, Perfect absorber, Polarization-independen

Potential Influences of Volcanic Eruptions on Future Global Land Monsoon Precipitation Changes

The global monsoon system is of exceptional socioeconomic importance owing to its impacts on two-thirds of the globe’s population. Major volcanic eruptions strongly influence global land monsoon (GLM) precipitation change. By using 60 plausible eruption scenarios sampled from reconstructed volcanic proxies over the past 2,500 years, 21st century volcanic influences on GLM precipitation projections are examined with an Earth system model under a moderate emission scenario. The decadal-scale ensemble spread with realistic eruptions (VOLC) increases by 17.5% and 20.1% compared to no-volcanic (NO-VOLC) and constant background-volcanic (VOLC-CONST) scenarios, respectively. Compared with NO-VOLC, the centennial mean VOLC GLM precipitation shows a 10% overall reduction and regionally, Asia is the most impacted. Changes in atmospheric circulation in the aftermath of large volcanic eruptions match the global warming response patterns well with opposite sign, with the North American monsoon precipitation enhanced following large volcanic eruptions, which is in sharp contrast to the robust decrease in Asian monsoon rainfall. Volcanic activity could delay the time of emergence of anthropogenic influence by five years on average over about 60% of the GLM area. Our results demonstrate the importance of statistical representation of potential volcanism for the projections of future monsoon variability. Quantifying volcanic impacts on regional climate projections and their socioeconomic influences on infrastructure planning, food security, and disaster management should be a priority of future work.publishedVersio

Production of a high-efficiency cellulase complex via β-glucosidase engineering in Penicillium oxalicum

Additional file 6: Table S1. Primers used in this study

Nrf2 Down-Regulation by Camptothecin Favors Inhibiting Invasion, Metastasis and Angiogenesis in Hepatocellular Carcinoma

Higher oxidant stress capacity could promote invasion and metastasis. A previous study showed hepatocellular carcinoma (HCC) expressed more Nrf2 than para-carcinoma tissue. The chemotherapeutics such as epirubicin (EPI) could increase Nrf2 expression, while Camptothecin (CPT) could inhibit tumor growth by down-regulating the key molecule of antioxidant stress signal—Nrf2. The role of Nrf2 in invasion and metastasis was still unclear. In this study, we use EPI and CPT to determine the invasion and metastasis in Huh7 cells, H22 and Huh7 mouse models. In Huh7 cells, Nrf2 expression and ROS level were found increased after incubation with EPI by western blot and flow cytometry assay. But with the combination of EPI and CPT, inhibition of Nrf2 could decrease proliferation, invasion, and metastasis, which were investigated by CCK8 assay, wound healing, and Transwell assays. In Huh7 and H22 mouse models, EPI promoted Nrf2 up-regulation and nucleus translocation. Tumor growth was obviously inhibited with a single application of EPI or CPT. The combination of EPI and CPT could inhibit Nrf2 expression but demonstrated more suppressing effect of tumor growth than EPI. Western blot and immunohistochemical staining study revealed that Nrf2 inhibition was beneficial in decreasing the expression of N-cadherin, MMP9, Snail as well as Twist, and increasing E-cadherin, which were associated with epithelial–mesenchymal transition (EMT). Nrf2 down-regulation promoted lung metastasis of H22 cells in vivo. In addition, H&E staining and immunofluorescence staining of VEGFR suggested angiogenesis of Huh7 and H22 tumors was reduced. In conclusion, down-regulation of Nrf2 demonstrated inhibition of invasion, metastasis, and angiogenesis of hepatoma, which may provide a potential therapy in HCC

Case report: An ectopic adrenocortical adenoma in the renal sinus

BackgroundEctopic adrenal tissue is rare in adults, with an incidence of only about 1%. We report a rare case of ectopic adrenocortical adenoma in the left renal sinus.Case PreentationA 57-year-old woman was admitted to the Department of Urology due to “a left kidney tumor” on physical examination. Multislice helical computed tomography (CT) showed the left kidney with an anterior lip mass near the hilum, approximately 2.3 cm × 2.2 cm in size. Preoperative renal artery CT angiography (CTA) showed no obvious abnormality. Laparoscopic resection of the left renal sinus mass was performed, and postoperative pathological findings showed ectopic adrenocortical adenoma. The tumor was a nonfunctional adenoma.ConclusionRenal ectopic adrenal cortical adenoma is rare. Most of them are nonfunctional adenomas, which cannot be clearly diagnosed by preoperative imaging examination and can often be diagnosed by postoperative pathology

Vibration performance prediction and reliability analysis for rolling bearing

The bearing vibration signal is a rich dynamic symptom of bearing wear, and the vibration signal of rolling bearing presents chaotic characteristics. Input and output variables of vibration signal can be constructed through phase space reconstruction, the Input and output variables can be imported into the prediction model for prediction. The prediction accuracy of the extreme learning machine (ELM) model, Kriging model and RBF model are compared, the results show that ELM has higher accuracy, so ELM chaos model is used to predict the future vibration time series data, and the forecasting error can be obtained by comparing the prediction value with the actual values so as to verity the feasibility of the ELM model. The prediction results of the future state of the bearing are processed as the grey-bootstrap method, and the performance reliability prediction of the bearing is realized by the Poisson counting process. The experimental data show that with the deepening of the fault degree, the reliability performance decreases gradually. The reliability performance of the bearing without fault is 100 %, and the reliability performance is 47.56 % when the inner ring faulty size is 0.72 mm