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Morphological properties and structures of the porcupine quills of different sizes can be explored in detail using micro-CT scans. Information including the porosity, volume thickness, number and lengths of stiffeners within quills are extracted via two modalities, using commercially available software and custom-developed scripts. Three segmentation methods, including the Otsu global thresholding, histographic segmentation and deep learning segmentation, are applied to identify the porosity variation based on different segmentation methods. Over segmentation is found when applying Otsu global thresholding, yielded the highest porosity. Histographic segmentation performed better than Otsu thresholding in segmenting CT slices, however speckles are observed in foam areas with lower intensity. Among all methods, deep learning segmentation resulted in the most reliable segmentation, and showed a consistent porosity across different quill sizes. Obtained results provide essential information for biomimicry research with an aim towards designing stronger and lighter structures for various engineering applications. [ABSTRACT FROM AUTHOR]

The discovery of an oil reservoir in Pishan Caldera of the Tarim Basin, northwest China, highlights the hydrocarbon exploration potential of large calderas. We used 3 D seismic interpretations, waveform clustering analysis, and seismic profiles to investigate the origin and evolution of Pishan Caldera, along with the mechanisms of hydrocarbon accumulation, and its significance for future oil and gas exploration. Pishan Caldera is located at depths of >7000 m, has an elliptical shape, extends over an area of 25 × 20 km, and is surrounded by ring faults. Pishan Caldera were the result of magma withdrawal and later magma intrusion. Volcanic eruptions, caldera collapse, and reactivation of Pishan Caldera resulted in Cretaceous oil migration and accumulation in Cretaceous breccia reservoirs. Ring faults, dense fracture networks, and lava tubes associated with the caldera acted as conduits for upward hydrocarbon migration. We propose a generalized model for hydrocarbon reservoirs related to the caldera, which includes five major reservoir types: drape anticline, fault block, volcanic-trapped, laterally sealed and lava tube type. Further efforts should be made to identify deep caldera structures that may be targets for hydrocarbon exploration. [ABSTRACT FROM AUTHOR]

Among various bio-inspired structures, sutures are a prominent structure which has evolved independently to optimize their functionalities. The diabolical ironclad beetle suture-inspired structure was fabricated using multi-material additive manufacturing (3D printing) system with TangoBlackPlus (TBP) as the soft suture layer and VeroWhitePlus (VWP) as the hard material. The print quality of the specimen was assessed through the optical microscope images, and a nanoindentation test was performed to investigate the interfacial hardness between TBP and VWP. Flexural properties of the suture structure when changing the thickness of the soft layers were then studied. Experiments were continued to identify the effect of combining different sizes of suture modules to develop the suture structure. A numerical simulation model was then generated and validated using the experimental results to proceed with the parametric study. A design of experiment (DoE) was developed to analyse the effect of changing the suture geometry to optimize performance. The research concluded that gradually decreasing the size of the suture allowed the structure to withstand higher loads. It was also evident that the deformability of the structure could be increased by incorporating smaller interlocking angles and larger a:b ratios, while larger interlocking angles and smaller a:b ratios generate stiff structures. [ABSTRACT FROM AUTHOR]

Chemotherapy is the primary treatment for advanced non-small-cell lung cancer (NSCLC). However, related dose-dependent toxicity limits its clinical use. Therefore, it is necessary to explore new strategies for improving the clinical outcomes while reducing the side effects of chemotherapy in the treatment of NSCLC. In this study, we designed and synthesized epidermal growth factor (EGF)-modified doxorubicin nanoparticles (EGF@DOX-NPs) that selectively targets the epidermal growth factor receptor (EGFR) overexpressed in lung tumor cells. When administered in combination with low-dose X-ray radiotherapy (RT), the NPs preferentially accumulated at the tumor site due to radiation-induced outburst of the local intra-tumoral blood vessels. Compared with DOX alone, EGF@DOX-NPs significantly decreased the viability and migration and enhanced the apoptosis rates of tumor cells in vitro. Also, the EGF@DOX-NPs significantly inhibited tumor growth in vivo, increasing the survival of the tumorbearing mice without apparent systemic toxic effects through RT-induced aggregation. The tumor cell proliferation was greatly inhibited in the RTþEGF@DOX-NPs group. Contrarily, the apoptosis of tumor cells was significantly higher in this group. These results confirm the promising clinical application of radiotherapy in combination with EGF@DOX-NPs for lung cancer treatment. [ABSTRACT FROM AUTHOR]

The emerging four-dimensional (4D) additive manufacturing (AM) has evolved from passive 3D printed objects to active ones, where materials and structures react to environmental stimulus. While nature is often the inspiration in fabricating static structures, it also plays a vital role in 4D printing. In order to survive and protect themselves from harsh environments, both plants and animals are equipped with unique movements and locomotion. However, the process of fabricating bioinspired 4D structures is complex and challenging. This review provides an overview of nature-inspired actuation to the realisation by 4D printing. Firstly, an understanding of nature actuations is briefly depicted. Next, the processes involved in the fabrication of 4D printed parts are described. Lastly, the challenges and potential applications are discussed. [ABSTRACT FROM AUTHOR]

The multi-modal imaging contrast agent has been attracted an increased interest to the tumor detecting and diagnosis in these recent years since the multi-modal imaging technology combines the advantages of several medical imaging modalities. A water-soluble fullerenol probe containing glypican-3 monoclonal antibody (GPC3-mAb) group mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 was synthesized by the incorporation of 5-formyl-1,1,3,3-tetramethylisoindolin-2-yloxyl (FTMIO), naphthalimide (NI) and GPC3-mAb as a tumor-targeting group into fullerenol C60(OH)11. This nanomaterial was further characterized by FTIR, UV, MS, fluorescence, etc., and then its properties including electron paramagnetic resonance (EPR), particle size, electrophoresis, electrochemical assay, cell cytotoxicity, cell uptake and fluorescent imaging of HeLa tumor cells in vitro were also evaluated. Experiment results indicated that mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 had similar fluorescent properties as NI and similar electrochemical and redox properties as 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl (CTMIO). Moreover, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 possessed low cell cytotoxicity, good fluorescence and good tumor-targeting property. Meanwhile, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 can be taken up highly by HeLa tumor cells, achieve good green fluorescent imaging in tumor cells and highly enhance the contrast of fluorescent images. Therefore, mAb-GPC3-C60(OH)10-(TMIO)3-(NI)3 can disperse homogeneously in aqueous solution and be used as a potential tumor-targeting dual-modal contrast agent for EPR imaging/fluorescence imaging (EPRI/FI). [ABSTRACT FROM AUTHOR]

As a new variety of Jatropha curcas L., Jatropha curcas var. nigroviensrugosus has high development and utilization values because of its high flowering and fruiting rates and yield. In this study, the complete chloroplast (cp) genome of J. nigroviensrugosus was assembled using Illumina sequencing data. Results revealed that its cp genome is 170,811 bp in length and has 106 unique genes, including 76 protein-coding genes, 26 tRNA genes and 4 rRNA genes. Phylogenetic analysis indicated that J. nigroviensrugosus was closely related to J. curcas. [ABSTRACT FROM AUTHOR]

In this paper, we develop a residential mortgage valuation tree model that incorporates housing price volatility, along with interest rates and interest rate volatility as determinants of mortgage yield spreads (above Treasury yields). When initial loan-to-value (LTV) ratios are low (e.g., 80%), the sensitivity of theoretical mortgage yield spreads to housing price volatility occurs for housing price volatility at annualized rates of 9%-11%. Annual price volatilities of 9%-11% are primarily observed in "hot" residential markets. When initial LTV ratios are high (e.g., 95%), we find the sensitivity of theoretical mortgage yield spreads to housing price volatility begins at annualized rates of 3%-8%, levels consistent with normal real estate markets. These sensitivities are generally irrespective of interest rate levels and interest rate volatilities. Ignoring the sensitivity of mortgage values to housing price volatility can cause lenders to misprice mortgages, and can cause insurance companies to misprice mortgage insurance. This can cause perverse incentives and unintended consequences, with substantial public policy implications including unsafe lending practices, excessive real estate speculation, and systemic risk. [ABSTRACT FROM AUTHOR]

While cyclosporine (CsA) inhibits calcineurin and is highly effective in prolonging rejection for transplantation patients, the immunological mechanisms remain unknown. Herein, the role of calcineurin signaling was investigated in a mouse allogeneic skin transplantation model. The calcineurin inhibitor CsA significantly ameliorated allograft rejection. In CsA-treated allograft recipient mice, CD11b+ Gr1+ myeloid-derived suppressor cells (MDSCs) were functional suppressive immune modulators that resulted in fewer gamma interferon (IFN-γ)-producing CD8+ T cells and CD4+ T cells (TH1 T helper cells) and more interleukin 4 (IL-4)-producing CD4+ T cells (TH2) and prolonged allogeneic skin graft survival. Importantly, the expression of NFATc1 is significantly diminished in the CsA-induced MDSCs. Blocking NFAT (nuclear factor of activated T cells) with VIVIT phenocopied the CsA effects in MDSCs and increased the suppressive activities and recruitment of CD11b+ Gr1+ MDSCs in allograft recipient mice. Mechanistically, CsA treatment enhanced the expression of indoleamine 2,3-dioxygenase (IDO) and the suppressive activities of MDSCs in allograft recipients. Inhibition of IDO nearly completely recovered the increased MDSC suppressive activities and the effects on T cell differentiation. The results of this study indicate that MDSCs are an essential component in controlling allograft survival following CsA or VIVIT treatment, validating the calcineurin-NFAT-IDO signaling axis as a potential therapeutic target in transplantation. [ABSTRACT FROM AUTHOR]

Na and Al-doped ZnO nano-powders were prepared by the sol-gel method. The XRD results indicated that all samples revealed a wurtzite-type hexagonal crystalline structure and the grain size of Al-doped ZnO decreases with increasing Al doping. The grain size of Na-doped ZnO is about 50 nm. Photocatalytic degradation of the methyl orange solution under the light of wavelength of 254 nm was performed to investigate the photocatalytic activity of Na, Al-doped ZnO powders. The results showed that Al dopant can greatly improve the photocatalytic activity of ZnO powder. The enhancement of photocatalytic activity of doped ZnO powers is mainly due to their smaller particle size and capability for reducing the electron hole pair recombination. [ABSTRACT FROM AUTHOR]

Giant permittivity at 1 MHz, which slightly changes with temperatures, is observed in a polymer composite. The dielectric spectroscopy demonstrates that the samples are electrically heterogeneous. The microstructure observation and the ingredient analysis evidence they self assemble the conducting cores surrounded by the insulating shells. The giant-dielectric phenomenon is therefore attributed to the percolation effect. The electrically heterogeneous microstructure with effective permittivity values about 10 000 can be fabricated by a simple solution casting process in air. The composite is an attractive option to the currently used printing dielectric and the future flexible electronics. [ABSTRACT FROM AUTHOR]

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported. [ABSTRACT FROM AUTHOR]

This study examines pathways to chemical dependency (CD) treatment for adolescents in a prepaid health plan, including factors influencing treatment referral and access. Data were collected from 419 adolescent CD treatment intakes ages 13 to 18 in a large, private health plan. The study examines predictors of referral from different sources and of mental health treatment prior to CD treatment. Referral patterns, problem severity, and psychiatric comorbidity differed by gender. Being male (p < .05) and higher scores on the Youth Self-Report (YSR) externalizing scale (p < .01) predicted a justice system referral. Using more types of substances predicted referral by medical and mental health providers (p < .05) and self-referral (p < .01). Higher YSR internalizing scores predicted referral from mental health (p < .01) and self-referral (p <.01). Being White versus African American (p < .05) or Latino (p < .01), older (p < .05), and having higher YSR internalizing scores (p < .05), a conduct disorder (p < .01), or a family member with a substance use problem (p < .01) predicted a mental health visit prior to CD intake. The findings raise questions regarding the role of health plans, clinicians, families, schools, and community agencies in referring and treating adolescents with substance use problems. They suggest that improved coordination of care may promote more integrated treatment practices, which could decrease substance use, mental health, and medical problem severity. [ABSTRACT FROM AUTHOR]

This paper considers string stability for vehicle longitudinal control from a practical implementation viewpoint. A different parameterization is used compared to previous work. Two following strategies are considered, i.e. Adaptive Cruise Control (ACC) and vehicle platooning with inter-vehicle communication. A simplified model and transfer function are used for analysis. It shows that ACC cannot achieve string stability while platooning with communication can achieve it, which agrees with practical test. [ABSTRACT FROM AUTHOR]

One important problem in tire modeling and its application to vehicle control is to quantitatively describe tire slip effect which is a dynamic interaction between the tire and road surface. Several tire slip models have been established, which can be divided as static models such as Bakker-Pacejka magic model and dynamic models such as LuGre model. It is generally recognized that the former provides a reasonably good curve-fitting from experimental data. However, the main difficulty in using those models is real-time estimation of the tire slip because it behaves as a random variable. It is impossible to estimate the tire slip exactly at each time instant. Even if this estimate is available, compensation for it in a controller is not easy. It is thus suggested that tire slip makes sense to longitudinal control only when it is considered statistically or on average. Based on this idea, a new definition of tire slip is proposed, which makes the real-time estimation and compensation practical. This method can also be applied to all-wheel-drive and/or all-wheel-brake vehicles without extra hardware installation. Two most important effects of tire slip on vehicle longitudinal motion, i.e. vehicle acceleration/deceleration capability and vehicle moving distance measurements, have been considered. Methods to compensate for the tire slip in longitudinal control have been proposed. Some experimental tests have been carried out. [ABSTRACT FROM AUTHOR]

A numerical study is performed of flow behind a rotationally oscillating circular cylinder in a uniform flow by solving the two-dimensional incompressible Navier-Stokes equations. The flow behavior in lock-on regime and the timing of vortex formation from the oscillating cylinder are studied. When the frequency of excitation of the cylinder is in the vicinity of the natural vortex formation frequency, a lock-on vortex formation regime appears. As the excitation frequency being increased relative to the natural frequency the initially formed vorticity concentration switches to the opposite side of the cylinder. The effects of oscillating frequency and amplitude on the vortex structures formed in the near wake of the cylinder are also investigated. Based on the present calculated results, some complicated vortex patterns are identified and are consistent with the previous experimental visualizations. [ABSTRACT FROM AUTHOR]

Discusses the output feedback stabilization of SISO nonlinear systems through dynamic sliding modes. Background on the sliding mode control and output feedback control; Semi-high gain observer into the closed-loop systems resulting from dynamic sliding mode control; Stability of the closed-loop system through the Lyapunov approach.