Research progress on medicinal components and pharmacological activities of polygonatum sibiricum.

ETHNOPHARMACOLOGICAL RELEVANCE: Polygonatum sibiricum, commonly known as Siberian Solomon's seal, is a traditional herb widely used in various traditional medical systems, especially in East Asia. In ancient China, the use of polygonatum sibiricum in medicine and food was mentioned in Li Shizhen's Bencao Gangmu of traditional Chinese medicine (TCM). It was also used in history of India in Vedic medicine. The plant is rich in bioactive substances such as polysaccharides, saponins, flavonoid and alkaloids. AIM OF THE REVIEW: The aim of this review is to understand the pharmacological and pharmacokinetics research progress of the major components of polygonatum sibiricum, and to prospect its potential application and development in the treatment of various diseases. MATERIALS AND METHODS: We conducted a systematic literature search against major online databases on the Web, including PubMed, ancient books, patents, PubMed, Wiley, Google Scholar, Web of Science, and others. We select the pharmacological process and mechanism of the main components of polygonatum sibiricum in a variety of diseases, and make a strict but careful supplement and in-depth elaboration to this review. RESULTS: Several studies have demonstrated the strong antioxidant properties of polygonatum extract, which can be attributed to the presence of flavonoids and other polyphenol compounds; for diabetes and other metabolic-related diseases, polygonatum saponins have particular advantages in regulating intestinal flora and lipoprotein concentration in organisms. In addition, the polysaccharides extracted from this plant have a strong anti-inflammatory effect, which is related to its ability to regulate proinflammatory cytokine and mediators. In the aspect of anti-tumor effect, polygonatum derivatives can induce cancer cell apoptosis mainly by adjusting the cell membrane potential and cell cycle. It is worth noting that the combined action of the main components of polygonatum also offers promising solutions for the treatment of the disease. CONCLUSION: Polygonatum polysaccharide has therapeutic effects on many diseases by adjusting cell signal pathways, polygonatum sibiricum have significant advantages in regulating intestinal flora, inducing apoptosis of tumor cells, activating antioxidant processes, etc. Further research and basic exploration are needed to prove the function and mechanisms of the main components of polygonatum sibiricum on related diseases. The study on the immunomodulatory properties of polygonatum revealed its potentiality of enhancing immune function, which made it an interesting subject for further exploration in the field of immunotherapy.

Study on the Low-Velocity Impact Response and Damage Mechanisms of Thermoplastic Composites.

A comparative experimental and numerical study of the impact behaviour of carbon-fiber-reinforced thermoplastic (TP) and thermoset (TS) composites has been carried out. On the one hand, low velocity impact (LVI) tests were performed on TP and TS composites with different lay-up sequences at different energy levels, and the damage modes and microscopic damage mechanisms after impact were investigated using macroscale inspection, C-scan inspection, and X-ray-computed tomography. The comparative results show that the initial damage valve force under LVI depends not only on the material, but also on the layup sequence. The initial valve force of the P2 soft layer with lower stiffness is about 11% lower than that of the P1 quasi-isotropic layer under the same material, while the initial valve force of thermoplastic composites is about 28% lower than that of thermoset composites under the same stacking order. Under the same stacking order and impact energy level, the damage area and depth of TP composites are smaller than those of TS composites; while under the same material and impact energy level, the indentation depth of P2 plies is greater than that of P1 plies, and the damage area of P2 plies is smaller than that of P1 plies, but the change of thermoplastic composites is not as obvious as that of thermoset composites. This indicates that TP composites have a higher initial damage threshold energy and impact resistance at the same lay-up order, while increasing the lay-up ratio of the same material by 45° improves the impact resistance of the structure. In addition, a damage model based on continuum damage mechanics (CDM) was developed to predict different damage modes of thermoplastic composites during low velocity impact, and the analytical results were compared with the experimental results. At an impact energy of 4.45 J/mm, the error of the initial damage valve force is 5.26% and the error of the maximum impact force is 4.36%. The simulated impact energy and impact velocity curves agree with the experimental results, indicating that the finite element model has good reliability.

Assessment of unilateral condylar hyperplasia with quantitative SPECT/CT.

Purpose: The current study aimedto assess condylar activityin patients with unilateral condylar hyperplasia (UCH) with quantitative SPECT/CT. Patients and methods: This retrospective study included patients with UCH who underwent quantitative SPECT/CT. SPECT analysis and quantification of SPECT/CT were performed, and the maximum count per pixel and SUVmax of either side of the condyles were calculated. Results: 39 patients were included in the analysisand classified into three subgroups according to the percentile differential right-left ratio: inactive group, left active (LA) group, and right active (RA) group. Totally, the SUVmax of the affected side is significantly higher than the unaffected side (active:5.93 ± 2.43 vs inactive:3.62 ± 1.76, P < 0.001), SUVmax-based ratios correlated well with the ratios based on maximum count (R = 0.944, P < 0.001). ROC analysis showed poorSUVmaxperformance in differentiation between theactive condyles and the inactive condyles due to the lower area under the curve (AUC) (0.588). In subgroup analysis, the affected side is significantly higher than the unaffected side in active groups with SUVmax, no significant difference was found between the active sides or the inactive sides of active groups. Interestingly, the SUVmax of the left side was statistically higher than that of the right sidein the inactive group (P = 0.01),while the left side of the right active group has significantlylower activitythan that in the inactive group, meanwhile,the right side showed no significant difference. Furthermore, each side showed no significant difference between the left active group and the inactive group. Conclusions: SUVmax is not an optimal measurement effectively used to evaluate active condyles. However, SUV ratios correlated well with the count ratios, and the left side of condyles showed a peculiar feature in condyle growth status reflected in radioactivity quantified with SPECT/CT, which needs further study to determine the role in the development of the UCH.

A Comparative Study on the Mechanical Properties of Open-Hole Carbon Fiber-Reinforced Thermoplastic and Thermosetting Composite Materials.

In this paper, the damage initiation/propagation mechanisms and failure modes of open-hole carbon fiber-reinforced thermoplastic composites and thermosetting composites with tension, compression, and bearing loads are investigated, respectively, by experiments and finite element simulations. The experimental evaluations are performed on the specimens using the Combined Loading Compression (CLC) test method, the tensile test method, and the single-shear test method. The differences in macroscopic damage initiation, evolution mode, and damage characteristics between thermoplastic composite materials and thermosetting composite material open-hole structures are obtained and analyzed under compressive load. Based on scanning electron microscope SEM images, a comparative analysis is conducted on the micro-failure modes of fibers, matrices, and fiber/matrix interfaces in the open-hole structures of thermoplastic and thermosetting composites under compressive load. The differences between thermoplastic and thermosetting composites were analyzed from the micro-failure mechanism. Finally, based on continuum damage mechanics (CDM), a damage model is also developed for predicting the initiation and propagation of damage in thermoplastic composites. The model, which can capture fiber breakage and matrix crack, as well as the nonlinear response, is used to conduct virtual compression tests, tensile test, and single-shear test, respectively. Numerical simulation results are compared with the extracted experimental results. The displacement-load curve and failure modes match the experimental result, which indicates that the finite element model has good reliability.

Combustion Behavior of Ethanol/Ether Molecules-Coated Al Nanoparticles with H2O Vapor by Non-equilibrium Molecular Dynamics Simulations.

Al nanoparticles (ANPs) have high reactivity and can improve the system's combustion performance. However, ANPs are susceptible to inactivation by external oxidants. Here, we use ethanol and ether molecules to coat ANPs and then compare and discuss the combustion process between coated ANPs and bare ANPs. Our results show that the ethanol/ether coating can adsorb more H2O molecules and increase the active Al atom number and the Al core area in the ignition stage. The combustion phase can be divided into four stages according to the rate of the combustion temperature. The ethanol/ether coating can enable ANPs to deliver a better combustion performance, reducing the ignition delay time of particles, greatly increasing the combustion temperature, and making the whole system enter the gas phase combustion stage. These will enable the ethanol/ether-ANPs systems to release more energy and improve the combustion efficiency of the system.

Combustion of Al Nanoparticles Coated with Nitrocellulose/Ethanol/Ether Molecules by Equilibrium Molecular Dynamics Simulations.

Al nanoparticles (ANPs) have high reactivity, but they are easily inactivated by external oxidants. To improve their surface properties, we coat ANPs with a nitrocellulose (NC)/ethanol/ether solution. Comparative discussions are raised from the coating to the combustion process. Our results show that NC/ethanol/ether forms a dense coating layer on the surface of annealed ANPs and passivates ANPs through physical and chemical adsorption. The coating layer can block the contact between the active Al atoms and O2 molecules at low temperatures. In the ignition phase, the NC/ethanol/ether coating layer can increase the density of the O2 molecules around the ANPs and the surface temperature of ANPs. At the end of the ignition phase, the number of O atoms adsorbed on the surface of NC/ethanol/ether coating-passivated ANPs (csANPs) and NC/ethanol/ether coating-annealed ANPs (cANPs) increased by about 60 and 50%, respectively, compared with passivated ANPs (sANPs). Since the desorption and diffusion of the coating layer will expose more reaction sites, ANPs have a shorter ignition delay and a lower ignition temperature. According to the change in atomic displacement, the combustion stage can be divided into three stages: surface oxidation/core melting diffusion, combustion inward propagation, and uniform combustion. The decomposition of NC molecules can increase the combustion speed, combustion time, and efficiency of ANPs. Such improvement will enable ANPs to obtain better storage and combustion performance and play a stronger role in the field of energetic materials.

[Chemical constituents of roots of Rodgersia aesculifolia].

The chemical compositions of Rodgersia aesculifolia were isolated and purified using a combination of silica gel, reverse phase silica gel, Sephadex LH-20 column chromatography, and semi-preparative HPLC. The structures were determined according to the physicochemical properties and spectroscopic data. The MTT method and the ABTS kit were used to measure the cytotoxicity and antioxidant capacity of all isolates, respectively. Thirty-four compounds were isolated from R. aesculifolia and elucidated as stigmastane-6ß-methoxy-3ß,5α-diol(1), stigmastane-3ß,5α,6ß triol(2), ß-sitosterol(3), ß-daucosterol(4), stigmast-4-en-3-one(5), bergenin(6), 11-ß-D-glucopyranosyl-bergenin(7), 11-O-galloybergenin(8), 1,4,6-tri-O-galloyl-ß-D-glucose(9), gallic acid(10), 3,4-dihydroxybenzoic acid methyl ester(11), ethyl gallate(12), ethyl 3,4-dihydroxybenzoate(13), caffeic acid ethyl ester(14), p-hydroxybenzeneacetic acid(15), 4-hydroxybenzoic acid(16), 2,3-dihydroxy-1-(4-hydroxy-3-methoxyphenyl)-propan-1-one(17), 3,7-dimethyl-2-octene-1,7-diol(18), crocusatin-B(19), neroplomacrol(20), geniposide(21), 3-hydroxyurs-12-en-27-oic acid(22), 3ß-trans-p-coumaroyloxy-olean-12-en-27-oic acid(23), aceriphyllic acid G(24), isolariciresinol(25), trans-rodgersinine B(26), cis-rodgersinine A(27), neo-olivil(28),(7S,8R)-dihydro-3'-hydroxy-8-hydroxy-methyl-7-(4-hydroxy-3-methoxy phenyl)-1'-benzofuranpropanol(29), 5,3',4'-trihydroxy-7-methoxyflavanone(30), quercetin 3-rutinoside(31), catechin-[8,7-e]-4ß-(3,4-dihydroxy-phenyl)-dihydro-2(3H)-pyranone(32), ethyl α-L-arabino-furanoside(33), and l-linoleoylglycerol(34). One new compound was discovered(compound 1), 25 compounds were first isolated from R. aesculifolia, and 22 compounds were first isolated from the Rodgersia plant. The results indicated that compounds 22-24 possessed cytotoxicity for HepG2, MCF-7, HCT-116, BGC-823, and RAFLS cell lines(IC_(50) ranged from 5.89 µmol·L~(-1) to 20.5 µmol·L~(-1)). Compounds 8-14 and 30-32 showed good antioxidant capacity, and compound 9 showed the strongest antioxidant activity with IC_(50) of(2.00±0.12) µmol·L~(-1).

Triplet generation at the CdTe quantum dot/anthracene interface mediated by hot and thermalized electron exchange for enhanced production of singlet oxygen.

Triplet energy transfer (TET) from semiconductor quantum dots (QDs) to molecular triplets has potential applications in photon up-conversion and singlet oxygen generation. Here, we have constructed a complex consisting of CdTe QDs as the donor and 9-anthracenecarboxylic acid (ACA) as the triplet acceptor, and studied the TET pathways and enhanced singlet oxygen generation properties. The results from steady-state and time-resolved spectroscopy demonstrate efficient TET with a total efficiency of over 80% from photoexcited CdTe QDs to ACA. Dynamical analysis clearly indicates two distinctive TET channels - hot electron exchange and thermalized electron exchange - mediating the TET process in the CdTe QDs-ACA complex. The TET efficiencies from hot electron exchange at high energetic levels and thermalized electron exchange on the lowest exciton state can reach ∼27% and ∼85%, respectively, following 530 nm excitation. This efficient TET endows the CdTe QDs-ACA complex with a good capability of generating singlet oxygen species with a yield of up to ∼59%. These findings contribute further insights to the mechanisms of interfacial TET processes and are significant in designing efficient TET systems based on semiconductor nanoparticles and triplet molecules.

Spinning thermal radiation from twisted two different anisotropic materials.

Thermal radiation has applications in numerous fields, such as radiation cooling, thermal imaging, and thermal camouflage. Micro/nanostructures such as chiral metamaterials with polarization-dependent or symmetry-breaking properties can selectively emit circularly (spin) polarized polarization waves. In this paper, we propose and demonstrate the spinning thermal radiation from two twisted different anisotropic materials. Taking industrial polymer and biaxial hyperbolic material α-MoO3 as an example, it is found that broadband spinning thermal radiation can be obtained from 13 µm to 18 µm. The spin thermal radiation of the proposed twisted structure originates from the combined effect of polarization conversion of circularly polarized wave and selective absorption of linearly polarized wave by the top and bottom layers of anisotropic materials, respectively. Besides, the narrowband spinning thermal radiation with 0.9 circular dichroism is achieved at wavelength of 12.39 µm and 18.93 µm for finite thickness α-MoO3 due to the epsilon-near-zero mode, and the magnetic field distribution can confirm the phenomenon. This work achieves broadband and narrowband spin thermal radiation and significantly enhances circular dichroism, which may have applications in biological sensing and thermal detection.

Integrative analysis of metabolome and transcriptome provide new insights into the bitter components of Lilium lancifolium and Lilium brownii.

Lilium, a perennial crop with great ornamental, medicinal and edible value, has been frequently used as functional food and medicine. Lilium lancifolium Thunb. (L. lancifolium) and Lilium brownii F.E.Brown var.viridulum Baker (L. brownii) are the most used medicinal species in China. However, the flavor compounds of these two species have not yet been clear. Here, metabolomics and transcriptome analysis were used to reveal the difference of the bitter substances of L. lancifolium and L. brownii. Qualitative results indicated that nine compounds are commonly existed in L. lancifolium and L. brownii, while nine compounds are unique in L. lancifolium and eight compounds are unique in L. brownii. Furthermore, quantitative results revealed that the content of regaloside A in L. lancifolium was nearly 2-7 folds higher than that of L. brownii, and the content of regaloside B in L. lancifolium was about 4-16 folds higher than that of L. brownii. Regaloside C and E were not detected in L. brownii. Transcriptome analysis showed that there were 90 unique genes up-regulated in L. lancifolium samples in the pathway of phenylpropanoid biosynthesis and 75 unique genes up-regulated in L. brownii samples, which could be related to the different content and chemical structure specificity of phenylpropanoid glycerol glucosides in L. lancifolium and L. brownii. The results of our in-deep research provide new insights into the bitter substances of L. lancifolium and L. brownii, and a further consideration for the chemical consistency and quality evaluation for Lilii bulbus.

Comprehensive Analysis of Tripterine Anti-Ovarian Cancer Effects Using Weighted Gene Co-Expression Network Analysis and Molecular Docking.

BACKGROUND Ovarian cancer has the highest mortality of gynecological cancers worldwide. The aim of this study was to identify the role of tripterine against ovarian cancer. MATERIAL AND METHODS GSE18520 and GSE12470 data sets were downloaded from the GEO database. WGCNA was used to analyze gene modules and hub genes related to ovarian cancer. These hub genes were intersected with tripterine targets, and GO and KEGG enrichment analyses were performed. HPA and GEPIA determined the expression of tripterine anti-ovarian hub genes in tumor tissues. Kaplan-Meier plotter was used to explore the role of hub genes in ovarian cancer prognosis. AutoDock was used to conduct molecular docking of tripterine and hub genes to observe whether the combination was stable. RESULTS By differential analysis of gene expression and the construction of WGCNA co-expression network, 5 hub genes, ARHGAP11A, MUC1, HBB, RUNX1T1, and FUT8, were screened by module gene screening. Seven biological processes and 20 KEGG-related pathways were obtained by gene enrichment. The expression of tripterine anti-ovarian hub genes ARHGAP11A, MUC1, and FUT8 were obtained by HPA and GEPIA. Using Kaplan-Meier plotter, the survival of ovarian cancer was negatively correlated with ARHGAP11A, MUC1, and FUT8. Molecular docking showed the combination of tripterine and FUT8 was most stable, having the greatest potential role. CONCLUSIONS Tripterine may be involved in megakaryocyte development and platelet production through potential genes ARHGAP11A, MUC1, HBB, RUNX1T1, and FUT8 and may have an anti-ovarian cancer effect in immune factors signaling, transporting and exchanging oxygen pathways, and autophagy pathways, through these 5 key genes.

Defect Detection of Composite Material Terahertz Image Based on Faster Region-Convolutional Neural Networks.

Terahertz (THz) nondestructive testing (NDT) technology has been increasingly applied to the internal defect detection of composite materials. However, the THz image is affected by background noise and power limitation, leading to poor THz image quality. The recognition rate based on traditional machine vision algorithms is not high. The above methods are usually unable to determine surface defects in a timely and accurate manner. In this paper, we propose a method to detect the internal defects of composite materials by using terahertz images based on a faster region-convolutional neural networks (faster R-CNNs) algorithm. Terahertz images showing internal defects in composite materials are first acquired by a terahertz time-domain spectroscopy system. Then the terahertz images are filtered, the blurred images are removed, and the remaining images are enhanced with data and annotated with image defects to create a dataset consistent with the internal defects of the material. On the basis of the above work, an improved faster R-CNN algorithm is proposed in this paper. The network can detect various defects in THz images by changing the backbone network, optimising the training parameters, and improving the prior box algorithm to improve the detection accuracy and efficiency of the network. By taking the commonly used composite sandwich structure as a representative, a sample with typical defects is designed, and the image data are obtained through the test. Comparing the proposed method with other existing network methods, the former proves to have the advantages of a short training time and high detection accuracy. The results show that the mean average precision (mAP) without data enhancement reached 95.50%, and the mAP with data enhancement reached 98.35% and exceeded the error rate of human eye detection (5%). Compared with the original faster R-CNN algorithm of 84.39% and 85.12%, the improvement is 11.11% and 10.23%, respectively, which demonstrates superb feature extraction capability and reduces the occurrence of network errors and omissions.

Growth trends analysis of unilateral condylar hyperplasia followed up with planar scintigraphy: Retrospective overview of 249 cases.

ABSTRACT: The current research aimed to retrospectively investigate the trends of the growth of condylar hyperplasia with serial planar scintigraphs.Patients of unilateral condylar hyperplasia with at least one follow-up planar scintigraph were retrospectively included in the study. Patients' age, gender at the initial scan, durations of following scans, and ratios between condylar activities were recorded.The study retrospectively included 111 patients of unilateral condylar hyperplasia. Patients were divided into 3 groups (progressive, relatively stable, regressive) according to ratio variation between initial and last scans. There were 23 (21%) patients fell into the progressive group, 40 (36%) patients into the relatively stable group, and 48 (43%) patients into the regressive group. More female patients were in the progressive group than those in the other groups (P < .01). There were no significant differences among the 3 groups in terms of age or durations of follow-up (P > .05). There were no strong relations between ratio differences and ages. However, a weak relation seems to exist in the regressive group with r = -0.240, (P = .10).Our investigation showed that more than a half of patients with condylar hyperplasia remain constantly or progressively active growth in patients in the follow-up scans. Roughly less than a half of patients showed regressive trends toward normal growth. Patients' age seemly does not play a role in the growth trend pattern, although there are no optimum follow-up periods, regularly follow-up scans are needed to determine the growth status of condylar hyperplasia.

Polygonatum sibiricum polysaccharides (PSP) improve the palmitic acid (PA)-induced inhibition of survival, inflammation, and glucose uptake in skeletal muscle cells.

Polygonatum sibiricum polysaccharides (PSP) can decrease the levels of fasting blood glucose, total cholesterol, and triglyceride (TG) in hyperlipidemic and diabetic animals. It can also reduce inflammatory cytokines and promote glucose uptake in adipocytes. However, the underlying molecular mechanisms of PSP in improving insulin resistance (IR) in skeletal muscle remain unclear. In this study, palmitic acid (PA) induced an IR model in L6 myotubes. After treatment, cell proliferation was measured using the CCK8. miR-340-3p, glucose transporter 4 (GLUT-4), and interleukin-1 receptor-associated kinase 3 (IRAK3) expression was measured by qRT-PCR. IRAK3 protein levels were measured by Western blotting. Glucose in the cell supernatant, TG concentration in L6 myotubes, and the levels of IL-1ß, IL-6, and TNF-α were measured by an ELISA. We found that cell survival, glucose uptake, and GLUT-4 expression in L6 myotubes were significantly suppressed, while lipid accumulation and inflammatory factor levels were enhanced by PA stimulation. Furthermore, PSP treatment markedly alleviated these effects. Interestingly, PSP also significantly reduced the upregulated expression of miR-340-3p in the L6 myotube model of IR. Furthermore, overexpression of miR-340-3p reversed the beneficial effects of PSP in the same IR model. miR-340-3p can bind to the 3'-untranslated regions of IRAK3. Additionally, PA treatment inhibited IRAK3 expression, whereas PSP treatment enhanced IRAK3 expression in L6 myotubes. Additionally, miR-340-3p also inhibited IRAK3 expression in L6 myotubes. Taken together, PSP improved inflammation and glucose uptake in PA-treated L6 myotubes by regulating miR-340-3p/IRAK3, suggesting that PSP may be suitable as a novel therapeutic agent for IR.

Aluminium nanoparticle modelling coupled with molecular dynamic simulation method to compare the effect of annealing rates on diethyl ether coating and oxidation behaviours.

This study was conducted to examine the influence of annealing rates on coating and oxidation performances of Aluminium (Al) nanoparticle (ANP) by molecular dynamic (MD) simulations. Four levels of cooling rates were utilized on melted ANP to obtain annealed ANP models with different microstructures. Then those nanoparticles were placed into pure diethyl ether or oxygen gas environments to perform coating and oxidation simulations respectively. It was revealed that there was a relatively optimal annealing condition for ANP models to recover the initial microstructure of themselves as much as possible. The ether coating behaviour of annealed ANP model under this condition was better than other models. In contrast, the oxidation of all different models was almost the same. So, the factor of the annealing rate had little effect on the oxidation results. Along with the growth of the oxide layer, the core of ANP still kept its annealed microstructure.

Molecular Dynamics Simulations of Melting Iron Nanoparticles with/without Defects Using a Reaxff Reactive Force Field.

Molecular dynamics simulations are performed to study thermal properties of bulk iron material and Fe nanoparticles (FNP) by using a ReaxFF reactive force field. Thermodynamic and energy properties such as radial distribution function, Lindemann index and potential energy plots are adopted to study the melting behaviors of FNPs from 300 K to 2500 K. A step-heating method is introduced to obtain equilibrium melting points. Our results show ReaxFF force field is able to detect size effect in FNP melting no matter in energy or structure evolution aspect. Extra storage energy of FNPs caused by defects (0%-10%) is firstly studied in this paper: defects will not affect the melting point of FNPs directly but increase the system energy especially when temperature reaches the melting points.

Comparison of design methods for negative pressure gradient rotary bodies: A CFD study.

Computational fluid dynamics (CFD) simulation is used to test two body design methods which use negative pressure gradient to suppress laminar flow separation and drag reduction. The steady-state model of the Transition SST model is used to calculate the pressure distribution, wall shear stress, and drag coefficient under zero angle of attack at different velocities. Four bodies designed by two different methods are considered. Our results show the first method is superior to the body of Hansen in drag reduction and the body designed by the first method is more likely to obtain the characteristics of suppressing or eliminating separation, which can effectively improve laminar flow coverage to achieve drag reduction under higher Reynolds number conditions. The results show that the negative pressure gradient method can suppress separation and drag reduction better than the second method. This successful design method is expected to open a promising prospect for its application in the design of small drag, small noise subsonic hydrodynamic hull and underwater weapons.

Is Single-Photon Emission Computed Tomography/Computed Tomography Superior to Single-Photon Emission Computed Tomography in Assessing Unilateral Condylar Hyperplasia?

PURPOSE: Single-photon emission computed tomography (SPECT) with technetium-99m diphosphates plays an important role in assessing unilateral condylar hyperplasia (UCH). The aim of this study was to evaluate whether quantification methods of SPECT plus CT (SPECT/CT) based on precise region-of-interest (ROI) drawings made under the guide of CT images were more accurate than conventional SPECT methods in the assessment of UCH growth. MATERIALS AND METHODS: This study is a nonblinded retrospective case series. Patients with UCH who had undergone SPECT/CT were enrolled. CT images were used to guide ROI drawings around the anatomic contour of the affected and contralateral condyles on SPECT/CT images versus fixed ROIs on conventional SPECT images. Mean and maximum values within the ROIs were recorded to compute percentile ratios. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristic (ROC) curves were calculated separately for SPECT-based methods (SPECTaver, SPECTmax) and SPECT/CT methods (SPECTCTaver, SPECTCTmax). The area under the ROC curve of each method was calculated and compared pairwise. RESULTS: Fifty-six patients (30 patients with progressive and 26 patients with nonprogressive mandibular asymmetry) were evaluated. SPECTmax had the highest sensitivity of 83.3%, followed by SPECTCTmax, SPECTaver, and SPECTCTaver. In contrast, SPECTaver, SPECTCTmax, and SPECTmax had similar specificities, PPVs, and NPVs. Nonetheless, SPECTCTaver had the lowest specificity, PPV, and NPV among all methods. ROC analysis also showed similar diagnostic performances among SPECTaver, SPECTmax, and SPECTCTmax (P > .05) and poorer diagnostic performance of SPECTCTaver compared with the other 3 methods (P < .05). CONCLUSIONS: The method of using ROIs drawn around the contour of the condyle on SPECT/CT images does not show improved accuracy over conventional SPECT-fixed ROI methods in assessing UCH.

Adsorption of ethanol molecules on the Al (1 1 1) surface: a molecular dynamic study.

The adsorption process of ethanol molecules on Al slabs was investigated by molecular dynamic simulations with a ReaxFF force field. The force field used in this paper has been validated by comparing adsorption energy results with quantum mechanical (QM) calculations. All simulations were performed under the canonical (NVT) ensemble. The single-molecule adsorption simulation shows that the hydroxyl group plays a more important role in the whole progress than the ethyl group. Besides, decomposition of hydroxyl groups was also observed during multimolecule adsorption processes. Simulations of adsorption processes of Al slab by ethanol molecules at different temperatures and pressures (controlled by the number of ethanol molecules) was also performed. System energy and radial distribution function (RDF) plots were invoked to describe adsorption processes and centro-symmetry parameter (CSP) analysis was adopted to study the surface properties with coating layers. Our results indicate that the whole adsorption process can be divided into two periods and the greater the pressure, the more ethanol molecules diffuse into the Al slab. How raising the temperature helps the adsorption processes is related to the initial number of molecules. The crystal structure of the Al surface will become amorphous under the constant impact of ethanol molecules.