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Esophageal foreign body impaction is a notable clinical emergency. If the high-risk esophageal foreign bodies are not removed in time, life-threatening complications, such as perforation, infection and injury to the vessels, may occur. In the present study, the case of a patient experiencing a foreign body sensation in the throat after ingesting a fish bone by mistake is presented. A high risk of impending arterial puncture was confirmed using thoracic CT and thoracic aorta CT angiography scanning. The ends of the fish bone were first confirmed using a fibro-bronchoscopy light source passing through the bronchial and esophageal walls, before biopsy forceps were used to successively free the thoracic aorta and bronchial ends under gastroscopy. Finally, the fish bone was safely removed using a combination of gastroscopy and the rarely used fibro-bronchoscopy, and the patient recovered well after standard care. In certain cases of foreign bodies, it is necessary to use multiple strategies in a timely manner according to the type and location of the ingested foreign body. [ABSTRACT FROM AUTHOR]

In order to reduce the leakage between the teeth of the twin-screw pump and improve the working performance, it is necessary to reduce the clearance between the teeth; In this paper, the end face profile equation of A-type screw rotor is derived by coordinate transformation method, the end face profile is generated based on MATLAB software, and the cusp and curve of the profile are optimized by arc transition method; The changes of pressure field and velocity field in the fluid domain of screw rotor before and after optimization are analyzed by finite element method; Taking the twin-screw pump as the research object, the fluid-structure coupling analysis and calculation of the master and slave screw rotors are carried out. The modal analysis of the screw without prestress and under the action of prestress is carried out respectively. Through the simulation calculation, the first six modal vibration shapes of the screw are taken, and the results of the two different states are compared. The results show that when the working pressure difference is 2 MPa, the maximum pressure after optimization increases by 1% compared with that before optimization. With the continuous increase of center distance, the maximum pressure of flow field fluctuates slightly up and down; The maximum velocity after optimization is 3.5 % lower than that before optimization. The comparison results show that the frequency of the screw rotor increases with the increase of the modal order of the screw rotor without prestress. The frequencies of the second and third orders are similar, and the amplitudes of the first and fourth orders are similar. After the fluid-structure coupling force is applied, the change trends of the modal frequencies of each order are basically the same, but the magnitudes of the frequencies and amplitudes change. The amplitude of the main and driven screw rotors under the fluid-structure interaction decreases rapidly in the third-order vibration mode and is lower than the amplitude without prestress. [ABSTRACT FROM AUTHOR]

Aiming at the problem that the vibration of space robot will reduce the dynamic accuracy of robot, a method of vibration suppression of space robot through trajectory planning is proposed. First, the joint was simplified to a linear torsion spring, and the flexible rod was modelled using the finite element method, resulting in a flexible motion model of the robot. Then, a rigid-soft coupled dynamic model that combined the flexible motion model with the Lagrange method was established. Using the dynamic model, the factors influencing the vibration behaviour of space robots were analysed. Finally, the space robot was subjected to vibration suppression through trajectory planning. As verified by experimental analysis, different trajectories and loads affect the excitation force and inherent characteristics of the robot. In the design process, it is necessary to consider the relationship between the excitation force and natural frequency. The trajectory planning method has apparent effects on vibration suppression. The vibration amplitude was significantly reduced, which can improve the positioning accuracy and work efficiency of the robot. [ABSTRACT FROM AUTHOR]

Objective: This study was designed to investigate the hypothesis that dietary quercetin (QUE) and coated sodium butyrate (SB) supplementation alleviate oxidative stress in the small intestine of diquat (DIQ)-challenged pullets. Methods: A total of 200 13-week-old pullets were divided into four groups: the control group (CON), the DIQ group, the QUE group, and the coated SB group, and injected intraperitoneally with either saline (CON) or diquat (DIQ, QUE, and SB) to induce oxidative stress on day 0. Results: On the first day, the malondialdehyde and superoxide dismutase (SOD) concentrations in the SB group were significantly different from those in the DIQ and QUE groups (p<0.05), and dietary supplementation with SB increased serum glutathione peroxidase (GSH-PX) levels compared with the DIQ group (p<0.05). Quercetin and SB increased the levels of CLAUDIN-1 and zonula occludens-1 (ZO-1) in the jejunum. On the tenth day of treatment, QUE attenuated the decrease in GSH-PX levels compared to those of the CON group (p<0.05), while SB increased SOD, GSH-PX, and total antioxidant capacity levels compared to those of the DIQ group. Nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase-1 (HO-1) mRNA levels in the QUE and SB groups increased (p<0.05) and CLAUDIN-1 mRNA levels in the QUE and SB groups were upregulated compared to those in the DIQ group ileum tissue. Conclusion: Supplementation of QUE and SB demonstrated the ability to relieve oxidative stress in pullets post DIQ-injection with a time-dependent manner and QUE and SB may be potential antioxidant additives for relieving oxidative stress and protecting the intestinal barrier of pullets. [ABSTRACT FROM AUTHOR]

The direct-imaging exploration can obtain comprehensive physical information of exoplanets, which is a key technology to search for extraterrestrial life in the future. In this paper, based on our recent high-contrast imaging data of ground-based telescope, the newly discovered multi-star candidates are presented. In the early stage, combined with the ability of high-contrast imaging equipment for the exoplanets in the ground-based system, we select about 1000 targets from published works which are compiled using the catalogs released by Gaia. These targets are distributed in different young star clusters. Recently, we used Hale Telescope at Palomar Observatory to carry out high-contrast imaging observation on 42 of the above targets in the K-band. Most of the observed targets are 7.5–14 in the V-band. In 2019, after two rounds of observation, we discover six multi-star system candidates. It is however difficult to find out whether these targets are single-star or multi-star systems in Gaia DR2 (Data Release 2) catalog and Gaia EDR3 (early Data Release 3) catalog. [ABSTRACT FROM AUTHOR]

Chemical examination of a fraction of the EtOAc extract of a marine-derived fungus Aspergillus sp. YPGA8 resulted in the isolation of two new compounds, namely aspertriols A-B (1-2). Compounds 1-2 possess an identical 2,3,4-trihydroxybutoxy moiety, which is rarely found in natural products. Their structures were determined by extensive analyses of spectroscopic data (1D and 2D NMR, HRESIMS). The bioassay study revealed that compounds 1 and 2 were inactive toward α-glucosidase. [ABSTRACT FROM AUTHOR]

The gut microbiome is a complex ecosystem that contributes to host nutrition and health. However, our current knowledge of the relationship between ambient temperature and gut microbiota of poultry is still limited. The objective of the present study was to characterize the intestinal microbiota of ducks exposed to high ambient temperature. Sixty 60-day-old Shaoxing ducks were allocated to control and heattreated groups. The ducks in the control group were kept at 25°C, and the ducks in the heat treatment group were raised at 30–40°C, which simulated the temperature change of day and night in summer. After 15 D, the intestinal contents of the duodenum, jejunum, and ileum were obtained from 6 ducks of each group. Genomic DNA was extracted and amplified based on the V4–V5 hypervariable region of 16S rRNA. The results showed that Firmicutes was the dominant bacterial phylum with the highest abundance in the contents of the small intestine of ducks, and the relative abundance of the phylum Firmicutes in all 3 intestinal segments was increased by high temperature. At the genus level, Lactobacillus was found to be the most dominant bacterial genus across 3 gut segments, and its abundance was increased in ducks under heat treatment. Compared with the corresponding intestine segment of control ducks, a total of 36 genera in the duodenum, 19 genera in the jejunum, and 6 genera in the ileum of heat-treated ducks were found to be significantly different in the abundance (linear discriminant analysis score .3.0, P, 0.05). Functional prediction of gut microbiota revealed that high temperature caused changes in the abundance of metabolism and transcription-related pathways. It is noteworthy that most of the altered pathways are related to metabolism. In conclusion, high temperature induced remarkable taxonomic changes in the gut microbiome of ducks, which might be related to the negative effects of high temperature in ducks. Our present study provided an important theoretical ground for high-temperature intervention. [ABSTRACT FROM AUTHOR]

Recently, from the new Spitzer Photometry and Accurate Rotation Curves data, McGaugh, Lelli & Schombert reported a tight radial acceleration relation between the observed total acceleration and the acceleration produced by baryons in spiral galaxies. The relation can be fitted by different functions. However, these functions can be discerned if we express the data in the form of a halo acceleration relation. The data reveals a maximum in the halo acceleration. We examined the NFW (cusp) and Burkert (core) profiles in the context of dark matter and different parameter families of the interpolating function in the framework of modified Newtonian dynamics. [ABSTRACT FROM AUTHOR]

The vomerovaginal canal (VVC) and palatovaginal canal (PVC) are two canals that open forward to the posterior wall of the pterygopalatine fossa (PPF). Although the anatomy and computed tomography (CT) appearances of the PVC have been well studied, the VVC has been rarely reported, especially in endoscopic examinations. Some studies have even failed to distinguish the PVC from the VVC on CT images. The purpose of this study was to demonstrate the anatomy of the VVC on endoscopy and reveal its differences from the PVC, and to analyse the relative positions of the VVC, PVC, and pterygoid canal on CT images. Ten dry skull bases were studied to observe the structures involved in the formation of the VVC. Dissection of four cadaveric heads was performed to demonstrate the anatomy of the VVC on endoscopy. Coronal CT image analysis in 70 patients was conducted to evaluate the distances and relative positions between the VVC, PVC, and pterygoid canal. The PVC and VVC were also compared on axial CT images. The osteological study showed the top wall of the VVC was the antero‐inferior wall of the sphenoid sinus. The VVC may be a helpful landmark in endoscopic endonasal transpterygoid approaches. Steps and discrimination in the dissections of the VVC and PVC were described. The interval between the PVC and VVC could be observed on both coronal and axial CT images. The coronal CT images of patients showed differences in the positions and distances among the three canals at both the anterior and posterior apertures of the PVC. The VVC can be easily mistaken for the PVC if its existence is not suspected. The anatomical morphologies and trajectories of the VVC and PVC differed on both nasal endoscopy and CT. The existence of the VVC should be considered during surgery and CT diagnosis within this area. [ABSTRACT FROM AUTHOR]

GaN thin films on Si(001) substrates are studied by infrared reflectance (IRR) spectroscopy at room temperature (RT). Variations in the IRR spectral line shape with the microstructure of GaN/Si(011) film are quantitatively explained in terms of a three-component effective medium model. In this model, the nominally undoped GaN film is considered to consist of three elementary components, i.e., single crystalline GaN grains, pores (voids), and inter-granulated materials (amorphous GaN clusters). Such a polycrystalline nature of the GaN/Si(001) films was confirmed by scanning electron microscopy measurements. It was demonstrated that based on the proposed three-component effective medium model, excellent overall simulation of the RT-IRR spectra can be achieved, and the fine structures of the GaN reststrahlen band in the measured RT-IRR spectra can also be interpreted very well. Furthermore, the volume fraction for each component in the GaN/Si(001) film was accurately deter! mined by fitting the experimental RT-IRR spectra with the theoretical simulation. These results indicate that IRR spectroscopy can offer a sensitive and convenient tool to probe the microstructure of GaN films grown on silicon. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The endoplasmic reticulum (ER) has a central role in the fine-tuning of environmental and internal stimuli. We herein report a ratiometric fluorescent probe, α-Naph, capable of determining basal H2O2 in the ER. The probe specifically responds to H2O2. The limit of detection of the probe is as low as 38 nM, making it a feasible sensor to image intracellular basal H2O2. In addition, utilizing its ratiometric property, we are able to measure the concentration of H2O2 in the ER quantitatively, eliminating the error caused by the probe concentration and environment. The intracellular concentration of H2O2 in the ER is calculated to be 0.692 µM under normal conditions and 1.26 µM under the stimulation of phorbol myristate acetate. [ABSTRACT FROM AUTHOR]

We study themass discrepancy-acceleration relation (MDAR) of 57 elliptical galaxies by their Einstein rings from the Sloan Lens ACS Survey (SLACS). The mass discrepancy between the lensing mass and the baryonic mass derived from population synthesis is larger when the acceleration of the elliptical galaxy lenses is smaller. The MDAR is also related to surface mass density discrepancy. At the Einstein ring, these lenses belong to high-surface-mass density galaxies. Similarly, we find that the discrepancy between the lensing and stellar surface mass density is small. It is consistent with the recent discovery of dynamical surface mass density discrepancy in disc galaxies where the discrepancy is smaller when surface density is larger. We also find relativistic modified Newtonian dynamics (MOND) can naturally explain the MDAR and surface mass density discrepancy in 57 Einstein rings. Moreover, the lensing mass, the dynamical mass and the stellar mass of these galaxies are consistent with each other in relativistic MOND. [ABSTRACT FROM AUTHOR]

The measurement of acoustic nonlinear response is known as a promising technique to characterize material micro-damages. In this paper, nonlinear ultrasonic approach is used to characterize the evolution of fatigue induced micro-cracks in polymer bonded explosives. The variations of acoustic nonlinearity with respect to fatigue cycles in the specimens are obtained in this investigation. The present results show a significant increase of acoustic nonlinearity with respect to fatigue cycles. The experimental observation of the correlation between the acoustic nonlinearity and fatigue cycles in carbon/epoxy laminates, verifies that an acoustic nonlinear response can be used to evaluate the progressive fatigue damage in the granular polymer bonded explosives. The sensitivity comparison of nonlinear and linear parameters of ultrasonic waves in the specimens shows that nonlinear acoustic parameters are more promising indicators to fatigue induced micro-damage than linear ones. The feasibility study of the micro-damage assessment of polymer bonded explosives by nonlinear ultrasonic technique in this work can be applied to damage identification, material degradation monitoring, and lifetime prediction of the explosive parts. [ABSTRACT FROM AUTHOR]

The dynamics of an elliptical galaxy within a couple of effective radii can be probed effectively by stars. However, at larger distances planetary nebulae (PNe) replace stars as the tracer of the dynamics. Making use of the motion of PNe, Romanowsky et al. measured the dynamics of three luminous elliptical galaxies (NGC821, NGC3379 and NGC4494) at large distances from the galactic centre. They found that little dark matter is needed up to six effective radii. Milgrom & Sanders showed that this result can be understood in the framework of MOdified Newtonian Dynamics (MOND). As more data are available in the past decade, we revisit this problem. We combine PNe data (up to six to eight effective radii) and stellar data from SAURON of seven elliptical galaxies, including those three galaxies in Romanowsky et al. with updated data and four other galaxies which have not been analysed before. We conclude that the dynamics of these galaxies can be well explained by MOND. [ABSTRACT FROM AUTHOR]

For effective use of a laser-produced-plasma (LPP) light source, an LPP is desired to emit a narrow spectral peak because the reflection spectrum of multilayer mirrors for guiding emission from the source is very narrow. While a Gd plasma has been studied extensively as an extreme ultraviolet (EUV) light source at around 6.8 nm, where La/B4C multilayer is reported to have a high reflectivity with a bandwidth of about 0.6%, all previous works using an Nd:YAG laser reported very broad spectra. This paper reports the first narrowing of the 6.8 nm peak in the case of using an Nd:YAG laser to generate a Gd plasma by using a pre-pulse. The best peak narrowing is observed when a pre-formed plasma is heated by a 1064 nm main laser pulse with a duration of 10 ns at the irradiation density of 4x 1011 W/cm² at a delay time of 50 ns after the pre-pulse irradiation. The observed spectral width of about 0.3 nm is about one fifth of the value for no pre-formed plasma. The peak wavelength of the 6.8 nm band shifted to a longer wavelength side and the peak was broadened both for lower and higher laser irradiation density. It is discussed that this robustness of the peak position of the 6.8 nm Gd peak against temperature change is suitable to achieve a narrow bandwidth from an LPP generated on solid. The observed spectra are compared with those previously reported in various conditions. [ABSTRACT FROM AUTHOR]

Real time online calibration of mass shift and intensity fluctuation to improve the accuracy of measurements for identification and quantitation in trace mass spectrometric analysis was demonstrated using extractive electrospray ionization mass spectrometry (EESI-MS). The signals of authentic compounds (e.g., lysine (Lys), proline (Pro), and histidine (His)) spiked into the extractive solution for the EESI process were used as the references to calibrate the signal of analytes (e.g., methionine (Met)) in the untreated sample solution. The intensity of the analyte signal was recorded simultaneously with the reference signals. The analyte signals at a given time point were calibrated on the basis of these correlation factors and real time signal response of the reference. The calibrated signal of Met at 10 µg L-1 was improved with a better signal-to-noise ratio (S/N from 2.3 to 4.3), better linearity (R² from 0.9758 to 0.9980), and reduced relative standard deviation (RSD from 9.8% to 6.0%). The shift of mass-to-charge ratio of Met signal between the detected and theoretical values was decreased from 247 ± 133 to -7 ± 167 ppm for 50 min of detection using a linear ion trap mass analyzer and was reduced from -0.27 ± 0.60 to -0.12 ± 0.23 ppm for 50 min of detection using an Orbitrap mass analyzer (P = 95%). This method has been validated using a certified standard amino acids solution (GBW(E)100062) and applied for quantitative detection of amino acids in chicken feed, urine, nutritional drink, and facial mask samples, showing that the method is useful to improve the accuracy of mass spectrometric analysis. [ABSTRACT FROM AUTHOR]

Clubroot is a serious threat to cruciferous crops in Shanghai, China, andTrichoderma harzianumT4 (T4) has shown good efficiency for its control. In this study, T4 was applied alone or in combination with the fungicide cyazofamid orBacillus subtilisXF-1, respectively, in a pot experiment to determine its efficiency of controlling clubroot. The control efficiency of T4 (79.3%) was significantly higher than that of XF-1 (63.1%,p < .05), and was similar to that of cyazofamid (93.2%,p > .05). Furthermore, T4 could promote the growth of the Chinese cabbageBrassica, particularly with respect to its fresh weight. These results indicated that T4 could be used as a green biofungicide not only to control the incidence of clubroot but also to increase the production of vegetables. The structure of microbial communities changed substantially when T4 was applied to the soil, as revealed by a non-metric multidimensional scaling test. T4 could not only reduce the average abundance ofBacillussp.andAcidiphiliumsp.(terminal restriction fragment 231 (TRF231), the most dominant fragment) but could also increase the average abundance ofStreptococcussp.(TRF307, the second most dominant fragment). Therefore, the high control efficiency of T4 against clubroot results not only from its ability to directly inhibit spore germination ofPlasmodiophora brassicaebut also from its ability to regulate the microbial communities in the rhizosphere soil ofB. chinensis, which could then inhibit the growth ofP. brassicaein soil indirectly. [ABSTRACT FROM AUTHOR]

Nowadays there are limited types of commercially available stationary phases for hydrophilic interaction liquid chromatography and therefore new ones with unique selectivity are urgently in demand to meet the need of separations of various polar and hydrophilic analytes. The present study describes the preparation and evaluation of a new stationary phase based on thiourea derivative modified silica for hydrophilic interaction liquid chromatography. Thiourea derivative was bonded onto the surface of silica particles via a mild addition reaction between -NH2 and -SCN, and the result of elemental analysis together with infrared analysis and solid-state NMR spectroscopy proved that the synthesis method was feasible. The new stationary phase succeeded in fast separations of a wide range of polar and hydrophilic analytes and exhibited excellent separation performance, especially unique selectivity. Furthermore, the effects of water content, buffer pH, and salt concentration on retention indicated that a complicated separation mechanism rather than partitioning was involved in the stationary phase and hydrogen bonding interaction between analytes and thiourea functional group could play a very important role in its selectivity. For sure, the new stationary phase is of a great potential as a new type of hydrophilic interaction liquid chromatographic stationary phase. [ABSTRACT FROM AUTHOR]

The effect of a naphthalimide pharmacophore coupled with diverse substituents on the interaction between naphthalimide-polyamine conjugates 1-4 and bovine serum albumin (BSA) was studied by UV absorption, fluorescence and circular dichroism (CD) spectroscopy under physiological conditions (pH = 7.4). The observed spectral quenching of BSA by the compounds indicated that they could bind to BSA. Furthermore, caloric fluorescent tests revealed that the quenching mechanisms of compounds 1-3 were basically static type, but that of compound 4 was closer to a classical type. The Ksv values at room temperature for compound-BSA complexes-1-BSA, 2-BSA, 3-BSA and 4-BSA were 1.438 × 104, 3.190 × 104, 5.700 × 104 and 4.745 × 105, respectively, compared with the value of MINS, 2.863 × 104 at Ex = 280 nm. The obtained quenching constant, binding constant and thermodynamic parameter suggested that the binding between compounds 1-4 with BSA protein, significantly affected by the substituted groups on the naphthalene backbone, was formed by hydrogen bonds, and other principle forces mainly consisting of charged and hydrophobic interactions. Based on results from the analysis of synchronous three-dimensional fluorescence and CD spectra, we can conclude that the interaction between compounds 1-4 and BSA protein has little impact on the BSA conformation. Calculated results obtained from in silico molecular simulation showed that compound 1 did not prefer either enzymatic drug sites I or II over the other. However, DSII in BSA was more beneficial than DSI for the binding between compounds 2-4 and BSA protein. The binding between compounds 1-3 and BSA was hydrophobic in nature, compared with the electrostatic interaction between compound 4 and BSA. [ABSTRACT FROM AUTHOR]

State of charge (SOC) estimation is essential to battery management systems in electric vehicles (EVs) to ensure the safe operations of batteries and providing drivers with the remaining range of the EVs. A number of estimation algorithms have been developed to get an accurate SOC value because the SOC cannot be directly measured with sensors and is closely related to various factors, such as ambient temperature, current rate and battery aging. In this paper, two model-based adaptive algorithms, including the adaptive unscented Kalman filter (AUKF) and adaptive slide mode observer (ASMO) are applied and compared in terms of convergence behavior, tracking accuracy, computational cost and estimation robustness against parameter uncertainties of the battery model in SOC estimation. Two typical driving cycles, including the Dynamic Stress Test (DST) and New European Driving Cycle (NEDC) are applied to evaluate the performance of the two algorithms. Comparison results show that the AUKF has merits in convergence ability and tracking accuracy with an accurate battery model, while the ASMO has lower computational cost and better estimation robustness against parameter uncertainties of the battery model. [ABSTRACT FROM AUTHOR]

Under partial shading conditions (e.g., due to buildings, trees, and clouds), multiple peaks may exist on the power-voltage (P-V) characteristic curve of photovoltaic (PV) array, leading to the conventional maximum power point tracking methods fail to extract the global maximum power point (GMPP). In this paper, a mathematical model of PV array under partial shading conditions with a voltage calculated principle is established. The presented model is implemented with an m-file in MATLAB software, which is used as a tool to study the non-linear characteristics of current-voltage (I-V) and P-V curves of PV array, as well as quickly develop the GMPP tracking controllers. Besides, an adaptive random particle swarm optimization (ARPSO) algorithm is presented to accurately extract the GMPP under partial shading conditions. Five simulation cases with different partial shading patterns are used to evaluate the performance of the presented approach by comparing with the conventional PSO, perturbation and observation (P&O), incremental conductance (INC), and genetic algorithm (GA) methods. Simulation results show that the ARPSO algorithm can rapidly find the GMPP under different shading conditions compared with the conventional PSO algorithm. Furthermore, the presented algorithm can accurately extract the GMPP when the shading condition sharply changes, while the P&O and INC algorithms fail to track the GMPP, but only detect the rightmost MPP encountered either local or global and regardless of the course. Besides, the ARPSO can rapidly and accurately converge to the GMPP with smaller population size and higher convergence speed compared with the GA. [ABSTRACT FROM AUTHOR]

The state of charge (SOC) is important for the safety and reliability of battery operation since it indicates the remaining capacity of a battery. However, it is difficult to get an accurate value of SOC, because the SOC cannot be directly measured by a sensor. In this paper, an adaptive gain nonlinear observer (AGNO) for SOC estimation of lithium-ion batteries (LIBs) in electric vehicles (EVs) is proposed. The second-order resistor-capacitor (2RC) equivalent circuit model is used to simulate the dynamic behaviors of a LIB, based on which the state equations are derived to design the AGNO for SOC estimation. The model parameters are identified using the exponential-function fitting method. The sixth-order polynomial function is used to describe the highly nonlinear relationship between the open circuit voltage (OCV) and the SOC. The convergence of the proposed AGNO is proved using the Lyapunov stability theory. Two typical driving cycles, including the New European Driving Cycle (NEDC) and Federal Urban Driving Schedule (FUDS) are adopted to evaluate the performance of the AGNO by comparing with the unscented Kalman filter (UKF) algorithm. The experimental results show that the AGNO has better performance than the UKF algorithm in terms of reducing the computation cost, improving the estimation accuracy and enhancing the convergence ability. [ABSTRACT FROM AUTHOR]

Eleven novel naphthalimide-diamine conjugates were synthesized and their structures were confirmed by elemental analysis, 1H-NMR, 13C-NMR and MS. Their in vitro antitumor activities were assessed using MTT assays on two cancerous cell lines K562, HCT116, and one normal hepatoma cell line QSG 7701. Compound 7f exhibited potent antitumor activity on HCT116 cells and favorable cell selectivity toward QSG 7701 compared with the positive control, amonafide. Moreover, 7f could block HeG2 cells in the G2/M phase and induce HeG2 cells apoptosis. The interaction of compound 7f with herring sperm DNA was studied by UV/vis absorption and fluorescence spectroscopy under physiological conditions (pH = 7.4). The observed spectral quenching of compound 7f by DNA and the displacement of EB from DNA-EB complex by compound 7f indicated that compound 7f could intercalate into DNA base pairs, which was also corroborated by the effect of KI on compound-DNA interaction. Further caloric fluorescent tests revealed that the quenching mechanism was a static type. Meanwhile, the binding constants, thermodynamic parameters and the effect of NaCl on compound-DNA interaction showed that the type of interaction force was mainly hydrogen bonds and the binding process was driven by hydrogen and van der Waals bonding. [ABSTRACT FROM AUTHOR]

We proposed a method to realize three-dimensional (3D) gradient index (GRIN) devices requiring large refractive index (RI) range with broadband performance. By combining non-resonant GRIN woodpile photonic crystals structure in the metamaterial regime with a compound liquid medium, a wide RI range (1-6.32) was fulfilled flexibly. As a proof-of-principle for the low-loss and nondispersive method, a 3D Eaton lens was designed and fabricated based on 3D printing process. Full-wave simulation and experiment validated its omnidirectional wave bending effects in a broad bandwidth covering Ku band (12 GHz-18 GHz). [ABSTRACT FROM AUTHOR]

Abstract: This study aimed to introduce a comprehensive process for separating and recovering antimony from a complex stibnite concentrate. Antimony is first leached through a chlorination–oxidation procedure to obtain SbCl3 solution. Antimony is then recovered in the forms of cubic crystal Sb2O3 (99.9%), high-purity cathode antimony (99.98%), crude cathode antimony (99.7%), high-purity SbOCl (99.9%), and crude antimony (>99%) through the following processes: hydrolysis, membrane electrowinning, hydrolysis–low temperature smelting, and hydrolysis–washing. [Copyright &y& Elsevier]

The power-voltage (P-V) characteristic of a photovoltaic (PV) array is nonlinear and time varying with the change in atmospheric conditions. As a result, the maximum power point tracking (MPPT) technique must be applied in PV systems to maximize the generated energy. The incremental conductance (INC) algorithm, one of the MPPT strategies, is widely used for its high tracking accuracy, good adaptability to rapidly changing atmospheric conditions, and easy implementation. This paper presents a modified asymmetrical variable step size INC MPPT method that is based on the asymmetrical feature of the P-V curve. Compared with conventional fixed or variable step size method, the proposed method can effectively improve tracking accuracy and speed. The theoretical foundation and design principle of the proposed approach are validated by the simulation and experimental results. [ABSTRACT FROM AUTHOR]

[Display omitted] • 46 triterpenoids including 12 new ones (1 – 12) were obtained from the mushroom Inonotus obliquus. • I. obliquus triterpenoids showed significant α-glucosidase inhibitory effect. • The structure − activity relationships of I. obliquus triterpenoids and α-glucosidase inhibition were discussed. • Line-weaver-Burk analysis indicated the possible dynamic binding mechanism of inonotusol F. • Molecular docking and molecular dynamics stimulation analysis revealed the interaction of inonotusol F and α-glucosidase. Bioassay-guided fractionation led to the isolation of a series of triterpenoids (1 – 46) including 12 new ones (1 – 12) from the mushroom Inonotus obliquus. The structures of all the compounds were elucidated by spectroscopic analysis as well as by comparison with literature data. Triterpenoids 1 – 3 , 6 , 7 , 16 , 24 , 25 , 27 , 38 , 43 , 44 and 46 showed strong α-glucosidase inhibition, with IC 50 values from 11.5 to 81.8 μM. Their structure–activity relationships were discussed. Inonotusol F (24) showed the strongest inhibitory activity and it presented noncompetitive inhibition against α-glucosidase. Molecular docking and molecular dynamics stimulation further demonstrated that GLU302 and PHE298 were key amino acids for the inhibition of inonotusol F (24) towards α-glucosidase. This study indicates the vital role of triterpenoids in explaining hypoglycemic effect of Inonotus obliquus and provides important evidence for further development and utilization of this mushroom. [ABSTRACT FROM AUTHOR]

The time delay in galaxy gravitational lensing systems has been used to determine the value of the Hubble constant. As with other dynamical phenomena on the galaxy scale, dark matter is often invoked in gravitational lensing to account for the "missing mass" (the apparent discrepancy between the dynamical mass and the luminous mass). Alternatively, modified gravity can be used to explain the discrepancy. In this paper, we adopt the tensor-vector-scalar gravity (TeVe S), a relativistic version of Modified Newtonian Dynamics, to study gravitational lensing phenomena and derive the formulae needed to evaluate the Hubble constant. We test our method on quasar lensing by elliptical galaxies in the literature. We focus on double-image systems with time delay measurement. Three candidates are suitable for our study: HE 2149-2745, FBQ J0951+2635, and SBS 0909+532. The Hubble constant obtained is consistent with the value used to fit the cosmic microwave background result in a neutrino cosmological model. [ABSTRACT FROM AUTHOR]

Abstract: A systematic numerical investigation of heat transfer in turbulent channel flow over dimpled surface is conducted. Both symmetric (or spherical) and asymmetric dimple with different depth ratios (h/D) and skewness (Dx and Dz) are considered for a series of Reynolds numbers Re 2H (based on bulk velocity and full channel height) between 4000 and 6000 while Prandtl number Pr is fixed at 0.7. It is found that the optimum dimple configuration for enhancing heat transfer measured in terms of the volume goodness factor is obtained for the case of asymmetric dimple with a depth ratio of h/D =15% and stream-wise skewness of Dx =15%. The heat transfer capacity in terms of Nusselt number is significantly increased, while the associated pressure loss is kept almost to the same level as the symmetric dimple with the same depth ratio. The present study also suggests that the heat transfer enhancement is closely related to ejection with counter-rotating flow, intensified secondary flow and vortex structures at the downstream rim of asymmetric dimple. All these findings suggest that a carefully designed asymmetric dimpled surface presents a viable means of enhancing heat transfer compared to the symmetric dimple. [Copyright &y& Elsevier]

Abstract: Waste printed circuit boards (WPCBs) contain plenty of valuable resources and hazardous materials, considered both an attractive secondary resource and an environmental contaminant. In the current research, a hydrometallurgical process combined ammonia leaching and solvent extraction to recover copper from the metal components of WPCBs, and the production of ultrafine copper particles stripped from a solution was investigated. The results of copper oxidation leaching indicated that 96.7% of copper can be recovered at a temperature of 35°C for a leaching duration of 2h with ammonium sulfate and ammonia concentration of 2mol/L at a solid:liquid ratio of 1:10g/cm3. The treatment of leach liquor for solvent extraction of copper with LIX 84 showed that 50% LIX 84 in kerosene, a 3min period of equilibration, and a pH of 10 were sufficient for the extraction of Cu(II) and 99.6% copper can be recovered from the leached solution. The results of the preparation of copper particles from stripped solution showed that mono-dispersed ultrafine copper particles with a diameter of approximately 1.5μm were obtained from the stripped solution containing 39.25g/L Cu2+ ion, oleic acid used as surfactant, and sodium hypophosphite as reductant. As the purity of the copper extracted from the leaching system was high and the as-synthesized ultrafine copper particles possess excellent anti-oxidation property, this WPCB metal-component hydrometallurgical recycling process has the potential of recovering high-purity ultrafine copper particles. [Copyright &y& Elsevier]

A novel green/biodegradable adsorbent, mungbean-coat, has been investigated for the adsorption of ultra-trace amounts of cadmium. Carboxylic groups on the bean-coat effectively retain the cadmium ions viacoordinative interactions. This well facilitates the adsorption of cadmium ions which can readily be recovered by acid elution. In practice, bean-coat is used to pack a mini-column for on-line adsorption and preconcentration of cadmium from environmental samples with detection by electrothermal atomic absorption spectrometry. By using a sample loading volume of 1.4 mL and an eluent volume of 70 μL, an enrichment factor of 19.8 along with a detection limit of 1.4 ng L−1are achieved. A precision of 2.4% RSD at the level of 0.05 μg L−1is derived. The present procedure has been applied for the determination of cadmium in certified reference materials (GBW08608 Trace Elements in Water and CRM 176 Trace Elements in a City Waste Incineration Ash) and a snow water sample. Fair agreements are reached between the certified values and the experimental results, in addition to a satisfactory spiking recovery for the snow water sample. In the present work, the use of green and biodegradable adsorbent as well as the elimination of use of organic solvent/eluent facilitates the development of a green analytical protocol. [ABSTRACT FROM AUTHOR]

The linear coefficient of thermal expansion (CTE) and the theoretical density are important for energetic materials. To obtain the CTE and theoretical density of 2,2′,4,4′,6,6′-hexanitrostilbene (HNS), X-ray powder diffraction (XRD) together with Rietveld refinement was employed to estimate the dimension and density change at a crystal lattice level, in the range of temperature 30-240 °C. The CTE of a-, b-, c-axis and volume were obtained as 7.6719 × 10/°C, 6.8044 × 10/°C, 1.1192 × 10/°C and 16.725 × 10/°C, respectively. Also, the possible reasons for the expansion property of HNS have been discussed by comparing its structure with 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). Based on the refined lattice parameters, the theoretical densities of HNS at various temperatures were obtained. By extrapolation of linear fitting the theoretical density of HNS at 20 °C was gotten as 1.7453 g/cm. Furthermore, a good thermal resilience of HNS has also been observed when the temperature returned from 240 to 30 °C. [ABSTRACT FROM AUTHOR]

A novel method for arsenic speciation is developed by interfacing solid phase preconcentration-liquid chromatography (LC) separation-gradient hydride generation (GHG)-quartz flame atomic absorption spectrometry (QFAAS). A MnO2mini-column is used to preconcentrate the arsenic species of As(iii), As(v), MMA and DMA, during which process, As(iii) is converted to As(v) viaoxidation by MnO2, while other species remain unchanged. The recovery of As(v) (i.e., the total amount of arsenate and arsenite in the original sample), MMA and DMA from the MnO2mini-column is facilitated by tetramethylammonium hydroxide (TMAH). After LC separation with C30 columns, arsenic species in the eluate are subject to gradient hydride generation with detection by QFAAS. On the other hand, cellulose fibre selectively adsorbs the chelating complex between As(iii) and ammonium pyrrolidine dithiocarbamate (APDC). After elution with HNO3, As(iii) in the original sample is quantified by graphite furnace atomic absorption spectrometry (GFAAS), and the amount of As(v) is obtained by subtraction. A sample volume of 2.0 mL derives enrichment factors of 14.0–19.2 for the arsenic species. By injecting 20 μL of eluate into the LC system (the eluate of As(iii)-PDC complex is injected into the GFAAS), detection limits of 0.019, 0.33, 0.39, 0.62 μg L−1are obtained for As(iii), As(v), MMA and DMA respectively. RSDs of less than 4.2% are achieved at the level of 2 μg L−1for As(v), MMA, DMA and 1 μg L−1for As(iii). The procedure is evaluated by speciating arsenic in snow water and Hijiki samples. [ABSTRACT FROM AUTHOR]

Mesoporous carbons with bimodal rod-like pore structures and tunable pore sizes from 3.66 to 5.42 nm were for the first time obtained by employing SBA-15 as templates and raffinose as carbon precursors. Small angle X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N2 sorption analysis, and Raman spectroscopy were used to determine the textural properties of the resulting materials. Bimodal frameworks with mesopores (4–5 nm) as well as macropores (125–130 nm) were achieved. The mesoporous carbons lost its ordered structure from the templates due to mesostructural shrinkage and collapse of mesopores, which resulted in partial duplicate of the template and pore-widening effect (meso to macropores). With the increasing of carbonization temperature from 500, 700 to 900 °C, the textural parameters such as specific surface areas, pore volumes, and mean pore diameters all increased significantly. In the temperature range studied, higher carbonization temperature would generate much more abundant porosity. The ratio of ID to IG ( ID/ IG) indicated a rather low crystallinity with the varying of aging temperature and the carbonization temperatures. The advantage of the procedure was that no acid or other chemical catalysts were involved during the infiltration and carbon formation process. [ABSTRACT FROM AUTHOR]

Arsenic speciation was performed based on liquid chromatographic separation followed by gradient hydride generation (GHG) and quartz atomizer atomic absorption spectrometric detection. The arsenic species, i.e., arsenate (As(V)), arsenite (As(III)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and trimethylarsine oxide (TMAO), were separated on C30-5 columns, and the concept of gradient hydride generation facilitates high conversion efficiency of the arsenic species into corresponding hydrides. The use of 2% L-cysteine in the GHG process gives rise to further improvements on the hydride generation efficiency of 13% to 32% for the arsenic species. The hydrides were separated in a unique design of gas–liquid separator, which not only ensures a complete separation but minimizes the dispersion of hydrides when delivering into the atomizer, resulting in a maximum of 13-fold improvement on the sensitivity of As(V) compared to previous studies. A separation process was finished within 800 s by injecting 100 µL sample solution, achieving detection limits of 0.9, 1.4, 1.4, 1.6, 1.5 µg/L, respectively, for As(V), As(III), MMA, DMA and TMAO. Precisions of less than 3% and 6% RSD were obtained for the five arsenic species at 100 µg/L and 20 µg/L, respectively. Three arsenic species, i.e., As(V), DMA and TMAO, were identified in Hijiki samples by this procedure. [ABSTRACT FROM AUTHOR]

This paper studies relationships between the best linear unbiased estimators (BLUEs) of an estimable parametric functions K β under the Gauss-Markov model { y, X β, σ2 Σ} and its misspecified model { y, X0 β, σ2 Σ0}. In addition, relationships between BLUEs under a restricted Gauss-Markov model and its misspecified model are also investigated. [ABSTRACT FROM AUTHOR]

The densities and viscosities of 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF 4] ionic liquid with methyl formate, methyl acetate, ethyl formate, and acetone have been measured at 298.15 K. The excess molar volume VmEand the viscosity deviations Δη for the binary mixture have been calculated and were fitted to the Redlich−Kister polynomials. The values of VmEand Δη are negative over the whole composition range. The minima in VmEand Δη are observed at about mole fraction of the ionic liquid, x≈ 0.3 and 0.7, respectively. [ABSTRACT FROM AUTHOR]

A cellulose fibre packed micro-column was used for sorption preconcentration of ultra-trace cadmium and successive coating of a thin layer of sodium tetrahydroborate solution. The retained cadmium was stripped with hydrochloric acid and in-situ vapor generation on the cellulose surface was initiated by reaction with the coated layer of reducing reagent. The vapor was detected by atomic fluorescence spectrometry (AFS). The integration of preconcentration, reducing reagent immobilization, elution and in-situ vapor generation onto the cellulose surface significantly simplifies the entire operation, where a single syringe pump suffices fluids delivery, providing sufficient stability and long-term reliability indicated by an intra-day RSD <5%. In addition, the detection limit and precision were significantly improved with respect to those obtained by a conventional elution approach. With a sampling volume of 1.0 mL, a quantitative retention of cadmium was obtained within a linear range of 0.01–1.0 μg L−1, along with an enrichment factor of 19.5 and a sampling frequency of 12 h−1. A precision of 1.9% at 0.2 μg L−1 was obtained and a detection limit of 3 ng L−1 was derived. The procedure was validated by analyzing certified reference materials of Riverine Water (SLRS-4), and Trace Elements in Water (GBW 08608), in addition to spiking recovery in a coastal sea water. [ABSTRACT FROM AUTHOR]

Background: Biomedical researchers often want to explore pathogenesis and pathways regulated by abnormally expressed genes, such as those identified by microarray analyses. Literature mining is an important way to assist in this task. Many literature mining tools are now available. However, few of them allows the user to make manual adjustments to zero in on what he/she wants to know in particular. Results: We present our software program, GenCLiP (Gene Cluster with Literature Profiles), which is based on the methods presented by Chaussabel and Sher (Genome Biol 2002, 3(10):RESEARCH0055) that search gene lists to identify functional clusters of genes based on upto-date literature profiling. Four features were added to this previously described method: the ability to 1) manually curate keywords extracted from the literature, 2) search genes and gene cooccurrence networks related to custom keywords, 3) compare analyzed gene results with negative and positive controls generated by GenCLiP, and 4) calculate probabilities that the resulting genes and gene networks are randomly related. In this paper, we show with a set of differentially expressed genes between keloids and normal control, how implementation of functions in GenCLiP successfully identified keywords related to the pathogenesis of keloids and unknown gene pathways involved in the pathogenesis of keloids. Conclusion: With regard to the identification of disease-susceptibility genes, GenCLiP allows one to quickly acquire a primary pathogenesis profile and identify pathways involving abnormally expressed genes not previously associated with the disease. [ABSTRACT FROM AUTHOR]

The NDRG4 gene is a member of the N-myc downregulated gene family which belongs to the alpha/beta hydrolase superfamily. The protein encoded by this gene is a cytoplasmic protein that may be involved in the regulation of mitogenic signalling in vascular smooth muscle cells. To map this gene in the chicken chromosome, a 6000 rads chicken-hamster radiation hybrid panel (ChickRH6) was used. Primers were designed according to the published human sequence for amplification of the chicken NDRG4 gene by comparative genomics. We compared the corresponding human mRNA sequence with the predicted coding sequence of the chicken NDRG4 gene, and found that the assembled contig shared a high percentage of similarity with that of the human gene. PCR of samples from the ChickRH6 revealed the locations of the NDRG4 gene to be linked to the marker PARD6G (5 cR away) with a LOD score of 20.46. Our present results support the idea that the RH technique is indeed a powerful tool for mapping genes due to its rapidity, precision, convenience and reproducibility. [ABSTRACT FROM AUTHOR]

The time-of-flight (TOF), typically associated with wave propagation processes, can be extracted from physical processes governed by parabolic PDE's, such as those occurring in eddy current testing of conductive materials. The main "tool" for extracting the TOF is the Q-Transform, which is an integral transform capable of relating solutions of hyperbolic PDE's to solutions of parabolic PDE's. The extraction of TOF is considerably more complex when the specimen to be tested has material interfaces, as in any realistic situation. Here we develop a technique capable of "removing" the effects due to known material interfaces. [ABSTRACT FROM AUTHOR]

We present a systematic study of tunneling leakage current in metal gate MOSFETs and how it is affected by the work function of the metal gate electrodes. Physical models used for simulations were corroborated by experimental results from SiO2 and HfO2 gate dielectrics with TaN electrodes. In bulk CMOS results show that, at the same capacitance equivalent oxide thickness (CET) at inversion, replacing a poly-Si gate by metal reduces: the gate leakage appreciably by one to two orders of magnitude due to the elimination of polysilicon gate depletion. It is also found that the work function ф β of a metal! gate affects tunneling characteristics in MOSFETS. It is particularly significant when the transistor is biased at accumulation. Specifically, the increase of ф β reduces the gate-to-channel tunneling in off-biased n-FET and the use of a metal gate with midgap ф β results in a significant reduction of gate to source/drain extension (SDE) tunneling in both n- and p-FETs. Compared to bulk YET, double gate (DG); VET1 has much lower off-state leakage due to the smaller gate to SDE tunneling. This reduction in off-state leakage can be as much as three orders of magnitude when high-κ gate dielectric is used. Finally, the benefits of employing metal gate DG structure in future CMOS scaling are discussed. [ABSTRACT FROM AUTHOR]

The authors derive an analytical model for threshold voltage for fully depleted single-gate silicon-on-insulator (SOI) MOSFETs taking into consideration the two-dimensional effects in both SOI and buried-oxide layers. Their model is valid for both long- and short-channel SOI MOSFETs and demonstrates the dependence of short-channel effects on the device parameters of channel-doping concentration, gate oxide, SOI, and buried-oxide thickness. It reproduces the numerical data for sub-0.1-µm gate-length devices better than previous models. [ABSTRACT FROM AUTHOR]

Presents the systematic investigation of the hole tunneling current through ultrathin oxynitride/oxide stack gate dielectrics in p-metal oxide semiconductor field-effect transistors (p-MOSFET). Effects of the increase in the dielectric constant; Energy band diagram of a p-MOSFET with oxide gate dielectric; Comparison of simulated and measured hole tunneling current through oxide and nitride gate dielectrics.

Postaxial polydactyly is characterised by fifth digit duplications in hands and/or feet. Two phenotypic varieties have been described. In type A, the extra digit is well formed and articulates with the fifth or an extra metacarpal. A rudimentary extra fifth digit characterises type B. Mutations in the GLi3 gene are associated with postaxial polydactyly in some families and a second locus has been identified on chromosome 13 but the majority of cases remain unexplained. We report here a third locus for postaxial polydactyly on chromosome 19p 13.1-13.2 in a large Chinese kindred with a combination of type A and B. Two-point linkage analysis showed the highest LOD score (Z[sub max]=5.85 at θ=0 CM) at marker D19S221. Recombination events with markers D19S1165 and D19S929 define the critical region for this postaxial polydactyly locus to a region of 4.3 CM on the genetic map. [ABSTRACT FROM AUTHOR]

Presents a model for hole quantization in inversion layer of metal oxide semiconductor (MOS) devices. Description of the model; Quantization effects in hole inversion layer; Analysis of the approach for calculating the uncertainties affecting the evaluation of traps parameter.