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•Influence of the fluid forces on the vibration characteristics of carbon nanotube is studied.•Effect of magnetic fields on vibration characteristics of single-walled nanotube is ...analyzed.•The force of the fluid on the nanotube wall is derived by Hamiltonian variation principle.•The governing equations of vibration frequency are based on the non-local beam model.•The fluid force has a significant influence on the vibration characteristics of nanotubes.
This paper studies the effects of fluid forces and magnetic fields on the vibration characteristics of single-walled carbon nanotube (SWCNT). The force of the fluid on the SWCNT tube wall is derived by using the Hamilton’s variation principle, and the Lorentz magnetic force obtained from Maxwell's relationship. The governing equations of motion are based on the non-local beam model under the action of fluid and longitudinal magnetic field. Moreover, in the present investigation, an analytical approach is also proposed to study the effect of fluid, small-scale effect and longitudinal magnetic field on the vibration frequency of single-walled fluid-conveying carbon nanotube. The numerical results show that the fluid has a significant influence on the vibration characteristics of SWCNTs, and the effect of the high-speed fluid on the carbon nanotube (CNT) wall cannot be neglected.
Diabetic cardiomyopathy (DCM) is one of the major complications of diabetes that causes mortality and morbidity in diabetic patients. Gastrodin (GSTD) is a bioactive phenolic glucoside component of ...an ancient Chinese herb Tianma (Gastrodia elata Bl.), which is widely used for cardiovascular and cerebrovascular diseases by ancient Chinese. Up to now, whether GSTD has a beneficial effect on DCM is unclear. Therefore, this study aimed to investigate the effect of GSTD on high glucose-induced injury in H9c2 rat cardiomyocytes and HL-1 mouse cardiomyocytes, and its underlying mechanisms. High glucose (33 mM) treatment caused cardiomyocyte toxicity, oxidative stress and apoptosis in both H9c2 and HL-1 cells. Under both normal (5.5 mM glucose) and high glucose conditions, GSTD showed protective effect against high glucose-induced cytotoxicity and promoted the nuclear translocation of Nrf2 in a concentration and time-dependent manner in H9c2 and HL-1 cells. Knockdown of Nrf2 expression using siRNA specifically targeting Nrf2 attenuated the protective effect of GSTD. Furthermore, GSTD promoted the nuclear translocation of Nrf2 via activating glycogen synthase kinse-3β (GSK-3β) signaling pathway. 4-benzyl, 2-methyl, 1, 2, 4-thiadiazolidine, 3, 5 dione (TDZD-8), an inhibitor of GSK-3β, inhibited the nuclear translocation of Nrf2 induced by GSTD, and attenuated the protective effect of GSTD as Nrf2 knockdown did. In summary, GSTD could protect against high glucose-induced cardiomyocyte toxicity via GSK-3β-mediated nuclear translocation of Nrf2.
Although the sun is really far away from us, some solar activities could still influence the performance and reliability of space-borne and ground-based technological systems on Earth. Those ...time-varying conditions in space caused by the sun are also called solar storm or space weather. It is known that aviation activities can be affected during solar storms, but the exact effects of space weather on aviation are still unclear. Especially how the flight delays, the top topic concerned by most people, will be affected by space weather has never been thoroughly researched. By analyzing huge amount of flight data (~ 4 × 10
records), for the first time, we quantitatively investigate the flight delays during space weather events. It is found that compared to the quiet periods, the average arrival delay time and 30-min delay rate during space weather events are significantly increased by 81.34% and 21.45% respectively. The evident negative correlation between the yearly flight regularity rate and the yearly mean total sunspot number during 22 years also confirms such correlation. Further studies show that the flight delay time and delay rate will monotonically increase with the geomagnetic field fluctuations and ionospheric disturbances. These results indicate that the interferences in communication and navigation during space weather events may be the most probable reason accounting for the increased flight delays. The above analyses expand the traditional field of space weather research and could also provide us with brand new views for improving the flight delay predications.
Solar flares are one of the severest solar activities that have important effects on near-Earth space. Previous studies have shown that flight arrival delays increase as a result of solar flares, but ...the intrinsic mechanism behind this relationship is still unknown. In this study, we conducted a comprehensive analysis of flight departure delays during 57 solar X-ray events by using a huge amount of flight data (~ 5 × 10
records) gathered over a 5-year period. It is found that the average flight departure delay time during solar X-ray events increased by 20.68% (7.67 min) compared to quiet periods. Our analysis also revealed apparent time and latitude dependencies, with flight delays being more serious on the dayside than on the nightside and longer (shorter) delays tending to occur in lower (higher) latitude airports during solar X-ray events. Furthermore, our results suggest that the intensity of solar flares (soft X-ray flux) and the Solar Zenith Angle directly modulate flight departure delay time and delay rate. These results indicate that communication interferences caused by solar flares directly affect flight departure delays. This work expands our conventional understanding of the impacts of solar flares on human society and provides new insights for preventing or coping with flight delays.
To assess the utility of preoperatively evaluating the vascular anatomy using multisection spiral computed tomography angiography (CTA) and image fusion technology in the treatment of obese patients ...undergoing laparoscopic radical resection for rectal cancer.
This randomised prospective study included 56 patients who underwent laparoscopic surgery for rectal cancer. Patients were randomly divided into two groups: the fusion imaging group (preoperative CTA and image fusion reconstruction n=28) and the control group (not performed CTA and image fusion reconstruction before the operation n=28). Duration of surgery was defined as the primary endpoint, and the volume of bleeding, the number of lymph node dissections, conversion to laparotomy, time to recovery of postoperative flatus, length of hospitalisation as well as perioperative complications were defined as secondary endpoints.
Compared with the control group, the duration of surgery in the image fusion group was shorter, bleeding volume was reduced, and the number of lymph node dissections was greater (p<0.05); however, there was no significant differences between the two groups regarding time to postoperative flatus recovery, conversion to laparotomy, length of hospitalisation, and perioperative complications (p>0.05).
Preoperative assessment of the vascular anatomy was an effective method and avoided some invisible risks during surgery, and resulted in a better therapeutic effect.
•Evaluation of the arteries is effective for obese rectal cancer patients.•The preoperative evaluation could shorten the operative time and reduce bleeding.•The preoperative evaluation could increase the number of lymph node dissections.
A novel wideband circularly-polarized patch antenna is presented. First, a new broadband 90deg hybrid feed network is proposed to have a bandwidth of 75% for the 10-dB return loss, good two output ...ports amplitude balance and a consistent 90deg (plusmn3deg) phase difference between two output ports. Then, a circular patch antenna fed by four sequential-rotation proximity-coupled L-probes orientated to have phase of 0deg, 90deg, 180deg and 270deg is presented. The four L-probes are connected to the respective ports of a feed network comprising a pair of the proposed broadband 90deg hybrid. It is found that the antenna can deliver a measured impedance bandwidth of 79.4% from 1.04 to 2.41 GHz for SWR<2, measured 2-dB and 3-dB axial-ratio bandwidths of 57% from 1.3 to 2.35 GHz and 82% from 1 to 2.4 GHz, respectively, and a measured gain bandwidth of 56.1% from 1.26 to 2.32 GHz for gain>3 dBi. The simulated impedance bandwidth is 94% from 0.9 to 2.5 GHz for SWR<2. The simulated 3-dB axial-ratio bandwidth is 63.8% from 1.25 to 2.42 GHz. The simulated gain bandwidth is 59.3% from 1.33 to 2.45 GHz for the gain>3 dBi. Good agreement is observed between simulation and measurement
Oral cancers, primarily squamous cell carcinomas (SCCs), progress either slowly or aggressively. Here we assessed the role of macrophages in SCC behavior. We used mouse SCC cells derived from tumors ...harboring a KrasG12D activation mutation and Smad4 deletion in keratin 15–positive stem cells and a human oral SCC cell line, FaDu, which has NRAS amplification and SMAD4 deletion. SCC cells were transplanted into immune-compromised or immune-competent (syngeneic) recipients. After tumors were established, we used clodronate liposomes to ablate macrophages. We found that the number of tumor-associated macrophages (TAMs) was not affected by the presence of T cells but differed considerably among tumors derived from different SCC lines. Clodronate significantly reduced TAMs and splenic macrophages, resulting in reduced SCC volumes. Tumors with clodronate treatment did not show decreased proliferation but did exhibit increased apoptosis and reduced vascular density. FLIP (Fas-associated via death domain-like interleukin 1β–converting enzyme inhibitory protein), an apoptosis inhibitor abundantly produced in tumor cells and TAMs, was reduced in tumor cells of clodronate-treated mice. Reduced FLIP levels correlated with reductions in phosphorylated nuclear NFκB p65 and NFκB inhibitor attenuated FLIP protein levels in SCC cells. Furthermore, TGFβ1 serum levels and pSmad3 were reduced in clodronate-treated mice, but their reductions were insufficient to reverse epithelial-mesenchymal transition or TGFβ-mediated angiogenesis in endothelial cells. Consequently, metastasis was not significantly reduced by macrophage reduction. However, reduced pSmad3 correlated with reduction of its transcriptional target, vascular endothelial growth factor A, in clodronate-treated tumor cells, which correlated with reduced vascular density in clodronate-treated tumors. Taken together, our study revealed that macrophages contribute to SCC expansion through interactions with tumor cells but are dispensable for SCC metastasis. Our study provides novel insights into understanding the contributions and limitations of TAMs in SCC progression.
The magnetostrictive/piezoelectric (MP) laminate composite has dramatically enhanced magnetoelectric (ME) effect when operating around resonance. The theoretical analysis of the resonant ME effect is ...investigated using the equivalent circuit method, in which the eddy current loss, the mechanical loss and the electric loss are all taken into account. The results indicate that, the mechanical loss plays a primary role in dissipations in resonant status, and a strong bias magnetic field is essential to restrain eddy current loss and improve the ME conversion efficiency.
A Kaczmarz method is presented for solving a class of fuzzy linear systems of equations with crisp coefficient matrix and fuzzy right-hand side. The iterative scheme is established and the ...convergence theorem is provided. Numerical examples show that the method is effective.
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