Utilizing the electrical resonance method, matrices encompassing elastic, piezoelectric, and dielectric properties were calculated for 0.36BiScO3-0.64PbTiO3 (BSPT) ceramics. The design parameters for ...the BSPT/epoxy 2-2 composite material were meticulously elucidated through simulations conducted via COMSOL software. Characterization outcomes unveil that the synthesized composite material exhibits diminished acoustic impedance and heightened electromechanical coupling in comparison to its piezoelectric ceramic counterparts. Subsequent to the design and fabrication of ultrasonic transducers employing both BSPT ceramics and BSPT/epoxy 2-2 composite material, a thorough investigation into their electrical and acoustic attributes ensued at ambient temperature and 200 °C. Test results manifest that the BSPT/epoxy 2-2 composite high temperature ultrasonic transducer (CHTUT) demonstrates a center frequency and bandwidth of 4.52 MHz and 54.71%, respectively, at room temperature. While, at 200 °C, these parameters are 3.54 MHz and 80.79%. The HTUT, under parallel scrutiny, exhibits a center frequency and bandwidth of 4.65 MHz and 34.23% at room temperature, respectively, and 4.52 MHz and 29.65% at 200 °C. These findings prove the robust ultrasonic performance of the CHTUT, even under elevated temperatures, with the BSPT ceramic based counterpart demonstrating superior temperature stability. Furthermore, the results of an imaging experiment involving steel step blocks at both room temperature and 200 °C align consistently with the acoustic test outcomes.
Background： The detection of solitary pulmonary nodules （SPNs） that may potentially develop into a malignant lesion is essential for early clinical interventions. However, grading classification ...based on computed tomography （CT） imaging results remains a significant challenge. The 2-^18F-fluoro-2-deoxy-D-glucose （^18F-FDG） positron emission tomography （PET）/CT imaging produces both false-positive and false-negative findings for the diagnosis of SPNs. In this study, we compared 18F-FDG and 3-deoxy-3-^18F-fluorothymidine （^18F-FLT） in lung cancer PET/CT imaging. Methods： The binding ratios of the two tracers to A549 lung cancer cells were calculated. The mouse lung cancer model was established （n = 12）, and micro-PET/CT analysis using the two tracers was performed. Images using the two tracers were collected from 55 lung cancer patients with SPNs. The correlation among the cell-tracer binding ratios, standardized uptake values （SUVs）, and Ki-67 proliferation marker expression were investigated. Results： The cell-tracer binding ratio for the A549 cells using the ^18F-FDG was greater than the ratio using 18F-FLT （P 〈 0.05）. The Ki-67 expression showed a significant positive correlation with the ^18F-FLT binding ratio （r = 0.824, P〈 0.01）. The tumor-to-nontumor uptake ratio of ^18F-FDG imaging in xenografts was higher than that of ^18F-FLT imaging. The diagnostic sensitivity, specificity, and the accuracy of ^18F-FDG for lung cancer were 89%, 67%, and 73%, respectively. Moreover, the diagnostic sensitivity, specificity, and the accuracy of ^18F-FLT for lung cancer were 71%, 79%, and 76%, respectively. There was an obvious positive correlation between the lung cancer Ki-67 expression and the mean maximum SUV of ^18F-FDG and ^18F-FLT （r = 0.658, P〈 0.05 and r = 0.724, P〈 0.01, respectively）. Conclusions： The ^18F-FDG uptake ratio is higher than that of ^18F-FLT in A549 cells at the cellular level.^18F-FLT imaging might be superior for the quantitative diagnosis of lung tumor tissue and could distinguish lung cancer nodules from other SPNs.
Cross-docks serve as distribution centers where shipments from different vendors are first consolidated according to their destinations, and then delivered to the retailers directly, with little or ...no storage in between. A critical problem encountered in the operation of cross-docks is the assignment of receiving and shipping doors, which greatly influences the labor or machinery cost of transferring the shipments between inbound and outbound transports. We show that the cross-dock door assignment problem (CDAP) is strictly non-deterministic polynomial-time complete. Although some deterministic algorithms have been reported to handle small-scale problems, the solutions to the middle- and large-scale CDAPs progressed at a slow pace. In this paper, we develop a nature-inspired dual-colony ant algorithm for CDAP, in which the two colonies of ants cooperatively search the optimal assignments of receiving and shipping doors to minimize the transferring costs of shipments. A collaborative local search strategy is designed and incorporated into the algorithm to enhance the search efficiency. Experiments have been conducted on a number of problem instances with different cross-dock sizes and freight flow patterns. The results show that the proposed algorithm is very competitive and can provide better solutions than the state-of-the-art heuristic algorithms.
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•Provide a generic framework for describing node placement problems.•Propose a flexible genetic algorithm for solving a variety of node placement problems.•Devise a novel crossover ...operator capable of adjusting the number of deployed nodes.•Application to wind farm layout optimization and RFID network planning problems.
Node placement problems, such as the deployment of radio-frequency identification systems or wireless sensor networks, are important problems encountered in various engineering fields. Although evolutionary algorithms have been successfully applied to node placement problems, their fixed-length encoding scheme limits the scope to adjust the number of deployed nodes optimally. To solve this problem, we develop a flexible genetic algorithm in this paper. With variable-length encoding, subarea-swap crossover, and Gaussian mutation, the flexible genetic algorithm is able to adjust the number of nodes and their corresponding properties automatically. Offspring (candidate layouts) are created legibly through a simple crossover that swaps selected subareas of parental layouts and through a simple mutation that tunes the properties of nodes. The flexible genetic algorithm is generic and suitable for various kinds of node placement problems. Two typical real-world node placement problems, i.e., the wind farm layout optimization and radio-frequency identification network planning problems, are used to investigate the performance of the proposed algorithm. Experimental results show that the flexible genetic algorithm offers higher performance than existing tools for solving node placement problems.
Traditional multi-objective evolutionary algorithms have encountered difficulties when handling many-objective problems. This is due to the loss of selection pressure incurred by the growing size of ...objective space. A variety of environmental selection operators have been proposed to address the issue, each has its distinct benefits and drawbacks. We develop a novel ensemble framework to enhance the effectiveness and robustness of many-objective optimization. The framework incorporates multiple environmental selection operators to guide the search, which are then viewed as voters to construct a mating pool. We design an ensemble mating selection strategy that makes decisions based on the preference information provided by the voters: individuals elected by more voters will be assigned larger possibilities to enter the mating pool. By doing so, high quality offspring can be reproduced from the elected promising candidates. To accommodate the multiple selection operators for voting, the framework maintains multiple parallel populations, where each population is updated by one of the selection operators. An instantiation of the framework with three popular operators is presented as a prime example. Extensive experiments have been conducted on a number of many-objective problems to examine the effectiveness of the proposed approach. Experimental results show that the mating selection strategy is capable of improving the quality of the obtained solution set.
•Devise a multi-population framework to combine advantages of multiple operators.•Propose a voting-based ensemble mating selection operator.•Develop a parallel program model capable of reducing the time overhead.•Conduct extensive experiments to verify the efficacy of the proposed approach.
Background：Nontraumatic spontaneous subarachnoid hemorrhage （SAH） is associated with a high mortality.This study was conducted to investigate the epidemiological features of nontraumatic spontaneous ...SAH in China.Methods：From January 2006 to December 2008,the clinical data of patients with nontraumatic SAH from 32 major neurosurgical centers of China were evaluated.Emergent digital subtraction angiography （DSA） was performed for the diagnosis of SAH sources in the acute stage of SAH （≤3 days）.The results and complications of emergent DSA were analyzed.Repeated DSA or computed tomography angiography （CTA） was suggested 2 weeks later if initial angiographic result was negative.Results：A total of 2562 patients were enrolled,including 81.4% of aneurysmal SAH and 18.6% of nonaneurysmal SAH.The total complication rate of emergent DSA was 3.9% without any mortality.Among the patients with aneurysmal SAH,321 cases （15.4%） had multiple aneurysms,and a total of 2435 aneurysms were detected.The aneurysms mostly originated from the anterior communicating artery （30.1%）,posterior commtmicating artery （28.7%）,and middle cerebral artery （15.9%）.Among the nonaneurysmal SAH cases,76.5% （n =365） had negative initial DSA,including 62 cases with peri-mesencephalic nonaneurysmal SAH （PNSAH）.Repeated DSA or CTA was performed in 252 patients with negative initial DSA,including 45 PNSAH cases.Among them,the repeated angiographic results remained negative in 45 PNSAH cases,but 28 （13.5%） intracranial aneurysms were detected in the remaining 207 cases.In addition,brain arteriovenous malformation （AVM,7.5%）,Moyamoya disease （7.3%）,stenosis or sclerosis of the cerebral artery （2.7%）,and dural arteriovenous fistula or carotid cavernous fistula （2.3%） were the major causes of nonaneurysmal SAH.Conclusions：DSA can be performed safely for pathological diagnosis in the acute stage of SAH.Ruptured intracranial aneurysms,AVM,and Moyamoya disease are the major causes of SAH detected by emergent DSA in China.
Tyrosine kinase inhibitors (TKIs) have improved the overall survival of patients with gastrointestinal stromal tumors (GISTs), but their side effects can impact dose intensity and, consequently, the ...clinical benefit. To date, no guideline or consensus has been published on the TKI-associated adverse reactions. Therefore, the Chinese Society of Surgeons for Gastrointestinal Stromal Tumor of the Chinese Medical Doctor Association organized an expert panel discussion involving representatives from gastrointestinal surgery, medical oncology, cardiology, dermatology, nephrology, endocrinology, and ophthalmology to consider the systemic clinical symptoms, molecular and cellular mechanisms, and treatment recommendations of GISTs. Here, we present the resultant evidence- and experience-based consensus to guide the management of TKI-associated side events in clinical practice.
Two new phenolic glycosides 7R,8R-threo-4,7,9,9'-tetrahydroxy-3-methoxy-8-O-4'-neolignan-3'-O-(3''-α-L-arabinofuranosyl)-β-D-glucopyranoside. (1), ...4-(4'-hydroxyphenyl)-2-butanone-4''-O-(6-β-D-xylosyl)-β-D-glucopyranoside (2), along with two known related analogues 7R,8R-threo-4,7,9,9'-tetrahydroxy-3-methoxy-8-O-4'-neolignan-3'-O-β-D-glucopyranoside (3), 4-(4'-hydroxyphenyl)-2-butanone-4'-O-β-D-glucopyranoside (4) were obtained from the roots of Sanguisorba officinalis. Combined with acid hydrolysis derivatization, the absolute configurations of these new compounds were elucidated by comprehensive analyses of spectroscopic data including nuclear magnetic resonance (NMR), electrospray ionization high resolution mass (HRESIMS) as well as circular dichroism (CD). Compounds 1-4 exhibited anti-inflammatory properties in vitro by attenuating the production of inflammatory mediators, such as nitric oxide (NO) as well as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6).
Solubilities, densities and refractive indices for the quaternary system KCl + KBO
2
+ K
2
SO
4
+ H
2
O at 298.15 K were determined using the isothermal dissolution equilibrium method. According to ...the experimental data, the diagrams of solubilities, densities, and refractive indices were plotted, respectively. The phase diagram consist of one invariant point, three isothermal dissolution curves, and three crystallization regions corresponding to potassium chloride (KCl), potassium metaborate hydrate (KBO
2
⋅1.33H
2
O), and potassium sulfate (K
2
SO
4
), respectively. The size of crystallization areas of salt is in the order K
2
SO
4
> KCl > KBO
2
⋅1.33H
2
O, which indicates K
2
SO
4
could be more easily separated from the system. The diagrams of solution density and refractive index changed regularly with changing concentration of KCl at 298.15 K.
As part of our search for compounds with cytotoxicity from endophytes of traditional Chinese medicines, two novel nor-sesquiterpenoids (1-2) with a new skeleton containing a tetrahydrofuran moiety ...were isolated form a rice medium of Fusarium tricinctum, an endophytic fungus isolated from the root of Ligusticum chuanxiong. The structures of these two previously undescribed compounds were elucidated by interpretation of the spectroscopic evidences including NMR correlations as well as MS data. The absolute configurations of these two compounds were confirmed by TD-DFT-ECD calculations. An MTT assay indicated that compound 1 exhibited moderate cytotoxic activity against MV4-11 with an IC
50
value of 22.29 μM.
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