A rotor CFD solver is developed for simulating the aerodynamic interaction phenomenon among rotor, wing and fuselage of a tilt rotor aircraft in its helicopter mode. The unsteady Navier–Stokes ...equations are discretized in inertial frame and embedded grid system is adopted for describing the relative motion among blades and nacelle/wing/fuselage. A combination of multi-layer embedded grid and ‘‘extended hole fringe" technique is complemented in original grid system to tackle grid assembly difficulties arising from the narrow space among different aerodynamic components, and to improve the interpolation precision by decreasing the cell volume discrepancy among different grid blocks. An overall donor cell searching and automatic hole cutting technique is used for grid assembly, and the solution processes are speeded up by introduction of Open MP parallel method. Based on this solver, flow fields and aerodynamics of a tilt rotor aircraft in hover are simulated with several rotor collective angles, and the corresponding states of an isolated rotor and rotor/wing/fuselage model are also computed to obtain reference solution.Aerodynamic interference influences among the rotor and wing/fuselage/nacelle are analyzed,and some meaningful conclusions are drawn.
AIM: In order to detect risk factors for esophageal cancer,a national research program was carded out during the Eighth Five-Year Plan (from 1991 to 1995).METHODS: Cixian County and Chichen County in ...Hebei Province were selected as the index and the control for the study fields with higher or lower incidence of esophagus cancer in China, respectively, In these areas, we investigated the pollution of three nitrogenous compounds in well water for drinking and the use of nitrogen fertilizer in farming.RESULTS: In well water, nitrate nitrogen, nitrite nitrogen and ammonia nitrogen were 8.77 mg/L, 0.014 mg/L and 0.009 mg/L in Cixian County in 1993, respectively. They were significantly higher than their levels (3.84 mg/L, 0.004 mg/L and 0.004 mg/L) in Chichen County (P<0.01, t=6.281,t=3.784, t=3.775). There was a trend that the nitrogenous compounds in well water increased from 1993 to 1996.The amount of nitrogen fertilizer used in farming was 787.6 kg per hectare land in Cixian County in 1991, significantly higher than 186 kg per hectare in Chichen County (t=9.603,P<O.O01).CONCLUSION: These investigations indicate that the pollution of nitrogenous compounds in well water for drinking is closely related to the use of nitrogen fertilizer in farming, and there is a significantly positive correlation between the level of three nitrogenous compounds in well water and the mortality of esophageal cancer (correlation coeffident =0.5992). We suggest that improvement of well system for drinking water quality should be an effective measure for esophageal cancer prevention and control in rural areas.
We report the observations of FRB 20220912A using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We conducted 17 observations totaling 8.67 hours and detected a total of 1076 ...bursts with an event rate up to 390 hr\(^{-1}\). The cumulative energy distribution can be well described using a broken power-law function with the lower and higher-energy slopes of \(-0.38\pm0.02\) and \(-2.07\pm0.07\), respectively. We also report the L band (\(1-1.5\) GHz) spectral index of the synthetic spectrum of FRB~20220912A bursts, which is \(-2.6\pm0.21\). The average rotation measure (RM) value of the bursts from FRB~20220912A is \(-0.08\pm5.39\ \rm rad\,m^{-2}\), close to 0 \(\rm rad\,m^{-2}\) and maintain relatively stable over two months. Most bursts have nearly 100\% linear polarization. About 45\% of the bursts have circular polarization with SNR \(>\) 3, and the highest circular polarization degree can reach 70\%. Our observations suggest that FRB~20220912A is located in a relatively clean local environment with complex circular polarization characteristics. These various behaviors imply that the mechanism of circular polarization of FRBs likely originates from an intrinsic radiation mechanism, such as coherent curvature radiation or inverse Compton scattering inside the magnetosphere of the FRB engine source (e.g. a magnetar).
Aim： To improve the therapeutic efficacy of cancer treatments, combinational therapies based on nanosized drug delivery system （NDDS） has been developed recently. In this study we designed a new NDDS ...loaded with an anti-metastatic drug silibinin and a photothermal agent indocyanine green （ICG）, and investigated its effects on the growth and metastasis of breast cancer cells in vitro. Methods： Silibinin and ICG were self-assembled into PCL lipid nanoparticles （SIPNs）. Their physical characteristics including the particle size, zeta potential, morphology and in vitro drug release were examined. 4T1 mammalian breast cancer cells were used to evaluate their cellular internalization, cytotoxicity, and their influences on wound healing, in vitro cell migration and invasion. Results： SIPNs showed a well-defined spherical shape with averaged size of 126.3＋0.4 nm and zeta potential of -10.3＋0.2 mV. NIR laser irradiation substantially increased the in vitro release of silibinin from the SIPNs （58.3% at the first 8 h, and 97.8% for the total release）. Furthermore, NIR laser irradiation markedly increased the uptake of SIPNs into 4T1 cells. Under the NIR laser irradiation, both SIPNs and IPNs （PCL lipid nanoparticles loaded with ICG alone） caused dose-dependent ablation of 4T1 cells. The wound healing, migration and invasion experiments showed that SIPNs exposed to NiR laser irradiation exhibited dramatic in vitro anti-metastasis effects. Conclusion： SIPNs show temperature-sensitive drug release following NIR laser irradiation, which can inhibit the growth and metastasis of breast cancer cells in vitro.
With the proliferation of network traffic, replaying traffic in a virtual environment faces many problems. In order to meet the requirements of traffic integrity and accuracy in the replay process, ...an accelerated traffic replay method based on time-compressed was proposed to achieve accelerated replay of real network traffic in a virtual environment. The method prioritized the compression of the largest time interval in the set of time intervals, and reduced the compression of the smaller intervals, thus reducing the traffic spike per unit time caused by time compression, and reducing the packet loss rate of traffic. The effect was measured in terms of packet loss rate, time interval error and similarity. The experiments show that this method has a lower packet loss rate and lower time interval error compared with the isometric compression method, although it performs worse in similarity.
The thermal stability of triple helical structure plays a critical role in collagen biosynthesis,function and degradation.CD technique was utilized to characterize the thermal stability of synthetic ...collagen mimic peptides.Fluorescence spectroscopy is widely used with easy access all around the world because of its inexpensive instrumentation,low operation cost,easy operation,and high sensitivity.Here we have developed an alternative fluorescence method to detect the thermal stability of collagen mimic peptides.We have demonstrated that fluorescence spectroscopy could measure the thermal stability of collagen mimic peptides with low concentrations under different circumstances.This highly sensitive fluorescence self-quenching assay will greatly expedite the studies of sequence-dependent properties of collagen mimic peptides,and it has great potential in the application of determining the thermal stability of triple helix systems such as collagens,collectins,adiponectin,macrophage scavenger and C1q.
We present a statistical study of decimetric type Ⅲ radio bursts, coronal mass ejections （CMEs）, and Hα flares observed in the period from July 2000 to March 2005. In total, we investigated 395 ...decimetric type Ⅲ radio burst events, 21% of which showed apparent correlation to CMEs that were associated with Hα flares. We noticed that the Hα flares which were strongly associated with CMEs were gradual events, and 82% of them took place before CMEs appeared in the field of view of LASCO C2; that most of the CME-associated radio bursts started in the frequency range around 750 MHz with a frequency drifting rate of several hundred MHz s-1, of which both positive and negative ones were recognized; and that the correlation of type Ⅲ radio bursts to CMEs without associated flares is fairly vague, less than 9%.
The performances of the Prostate Cancer Prevention Trial （PCPT） risk calculator and other risk calculators for prostate cancer （PCa） prediction in Chinese populations were poorly understood. We ...performed this study to build risk calculators （Huashan risk calculators） based on Chinese population and validated the performance of prostate-specific antigen （PSA）, PCPT risk calculator, and Huashan risk calculators in a validation cohort. We built Huashan risk calculators based on data from 1059 men who underwent initial prostate biopsy from January 2006 to December 2010 in a training cohort. Then, we validated the performance of PSA, PCPT risk calculator, and Huashan risk calculators in an observational validation study from January 2011 to December 2014. All necessary clinical information were collected before the biopsy. The results showed that Huashan risk calculators 1 and 2 outperformed the PCPT risk calculator for predicting PCa in both entire training cohort and stratified population （with PSA from 2.0 ng ml^-1 to 20.0 ng ml^-1）. In the validation study, Huashan risk calculator 1 still outperformed the PCPT risk calculator in the entire validation cohort （0.849 vs 0.779 in area under the receiver operating characteristic curve AUC） and stratified population. A considerable reduction of unnecessary biopsies （approximately 30%） was also observed when the Huashan risk calculators were used. Thus, we believe that the Huashan risk calculators （especially Huashan risk calculator 1） may have added value for predicting PCa in Chinese population. However, these results still needed further evaluation in larger populations.
AIM：To identify the novel methylation-silenced gene pentraxin 3（PTX3） in esophageal squamous cell carcinoma（ESCC）.METHODS：PTX3 mRNA expression was examined in six human ESCC cell lines,one human ...immortalized normal esophageal epithelial cell line,primary ESCC tumor tissue,and paired adjacent nontumor tissue using reverse transcription polymerase chain reaction（RTPCR）.Semi-quantitative immunohistochemistry was used to examine cellular localisation and protein levels.Methylation specific PCR and bisulphite genomic sequencing were employed to investigate the methylation of the candidate gene.RESULTS：In the majority of ESCC cell lines,we found that PTX3 expression was down-regulated due to gene promoter hypermethylation,which was further confirmed by bisulphite genomic sequencing.Demethylation treatment with 5-aza-2＇-deoxycytidine restored PTX3 mRNA expression in ESCC cell lines.Methylation was more common in tumor tissues（85%） than in adjacent nontumor tissues（25%）（P 〈 0.01）.CONCLUSION：PTX3 is down-regulated through promoter hypermethylation in ESCC,and could potentially serve as a biomarker of ESCC.
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