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The resistive switching of polymer films embedded with nanoparticles (NPs) offers the promise for future flexible and transparent memory applications. However, the polymer/NP interfacial effect on switching behavior under various mechanical stimuli is a vital issue that has received scant attention. Here, polymer thin films embedded with TiO 2 NPs were fabricated by vacuum spray method to study how the polymer/NP interface affects the switching behavior, especially under severe bending conditions. Compared with that of the initial sample, the ON/OFF ratio decreases by two orders of magnitude with the conduction mechanism translating from trap-controlled space charge limited current conduction to Poole−Frankel emission after repetitive bending. Surface wrinkle and interfacial micro cracks were observed. Using the finite element analyses and quantum chemical calculation, we show that the TiO 2 NPs produce strain-sensitive regions within the film, and micro cracks initiate and propagate along the polymer/NP interface under severe bending. Such cracks can serve as vacuum gap to block the carriers transport and further result in the deterioration of switching performance. [ABSTRACT FROM AUTHOR]

Pre-stressed high-strength concrete (PHC) pipe piles have been widely used in the pile foundations of buildings and bridges which are usually designed elastic based on the capacity design principle. However, when the PHC pipe pile comes to the foundations of Integral Abutment Jointless Bridges (IAJBs), limited ductility might apply in order to accommodate the relatively large deformation demand under the effect of temperature fluctuations or earthquake. The conventional design methods for PHC pipe piles remain in doubt. This paper focuses on low cycle pseudo-static tests on 4 PHC pipe-pile models with various pre-stress levels to gain insight into their mechanical behaviors with consideration of soil-pile interaction. Medium sand was employed in the tests. The details of the experiments are introduced, including design of the models, instrumentation and loading scheme. The testing results indicate that the damages of the PHC pipe piles are mainly concentrated at 4D to 8D of embedded depths. Moreover, the pre-stress level and reinforcement ratio have a significant influence on the failure mode of PHC pipe piles, especially on the distribution of internal force and moment along piles. It is found that the interaction effect of pile-soil strengthens with the pre-stress level which is beneficial to the seismic performance. Furthermore, the backbone of the PHC pipe piles model has four stages: elastic, elastic-plastic, plastic hardening, and failure. It is concluded that PHC pipe piles perform favorably plastic and ductile behavior, and their failure modes are flexural (bending) not brittle (shear). Finally, the PHC pipe pile has an appreciable energy dissipation and deformation capacity, and hence can be used for pile foundations in IAJBs. [ABSTRACT FROM AUTHOR]

Objective To assess the clinical and radiographic outcomes of posterior vertebral column resection (PVCR) without anterior support in treatment of Yang type A severe rigid thoracic kyphoscoliosis. Methods The records of 27 Yang type A severe thoracic kyphoscoliosis patients treated with PVCR without anterior support from January 2010 to September 2013 were analyzed retrospectively. Intraoperative multimodal neurophysiological monitoring was conducted in all patients. The 6 modes were somatosensory evoked potential, motor evoked potential, descending neurogenic evoked potential, spinal cord evoked potential, and electromyography (both triggered and free run). Radiographic parameters and complications were used to evaluate the clinical outcomes. Results PVCR without anterior support was conducted successfully in all 27 patients. Intraoperative monitoring events occurred in 3 patients (3/27); of these, 1 patient (1/27) showed postoperative spinal cord injury, but completely recovered within 9 months after the operation (Frankel level E). The number and osteotomy space of vertebrae resection were mean 1.33 levels and 3.7 cm, respectively. All cases achieved good coronal and sagittal curve correction. No implant related complications occurred until the latest follow-up. The average follow-up was 40.1 months (range, 24–59 months). Conclusions In this study, we found that posterior vertebral column resection (PVCR) without any anterior support with a mean 3.7 cm shortening of the spinal column is safe, if close and unyielding contact of end plates can be obtained. A comprehensive understanding of the technique and intensive intraoperative neuromonitoring is mandatory to perform these challenging and complex spine deformity correction procedures safely. [ABSTRACT FROM AUTHOR]

Addressable molecular junctions based on a thiol-functionalized oligo (3-methylthiophene) derivative incorporated with pyridine unit were fabricated using polymer stamp-printing method. The junction charge transport was measured from 95 to 299 K under both dark and light conditions. Asymmetric current–voltage characteristics with temperature, light, and bias-direction dependence were observed. Simmons tunneling combined with hopping play dominant roles at low bias under both dark and light. The thermionic and Poole–Frankel emissions are also found to affect the charge transport in some cases. Based on the density functional theory in conjunction with the non-equilibrium Green's function method, we investigated the transport properties of a series of single-molecule junctions with different molecular structures, in which negative differential resistance was observed. Density functional theory calculation and transmission spectrum show that the tunneling barrier may depend on the relative energetic position of the frontier molecular orbitals with respect to the metal Fermi level under the effects of bias and temperature. [ABSTRACT FROM AUTHOR]

A two-dimensional (2D) HPLC system focusing on the determination of phenylalanine (Phe) enantiomers in mammalian physiological fluids has been developed. ᴅ-Phe is indicated to have potential values as a disease biomarker and therapeutic molecule in several neuronal and metabolic disorders, thus the regulation of ᴅ-Phe in mammals is a matter of interest. However, the precise determination of amino acid enantiomers is difficult in complex biological samples, and the development of an analytical method with practically acceptable sensitivity, selectivity and throughput is expected. In the present study, a 2D-HPLC system equipped with a reversed-phase column in the 1st dimension and an enantioselective column in the 2nd dimension has been designed, following the fluorescence derivatization of the target amino acid enantiomers with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F). The analytical method was validated using both plasma and urine samples, and successfully applied to human, rat and mouse fluids. Trace levels of ᴅ-Phe were determined in the plasma, and the %ᴅ values were around 0.1% for all species. In the urine, relatively large amounts of ᴅ-Phe were observed, and the %ᴅ values for humans, rats and mice were 3.99, 1.76 and 5.25%, respectively. The relationships between the enzymatic activity of ᴅ-amino acid oxidase (DAO) and the amounts of intrinsic ᴅ-Phe have also been clarified, and high ᴅ-Phe amounts were observed (around 0.3% in the plasma and around 50% in the urine) in the DAO deficient rats and mice. • A 2D-HPLC system for Phe enantiomers in mammalian plasma and urine was developed. • The analytical method was successfully validated using both plasma and urine. • Trace levels of D-Phe (%D around 0.1%) were determined in the plasma for all species. • High D-Phe amounts were observed in the DAO deficient rats and mice. [ABSTRACT FROM AUTHOR]

Background The use of posterior vertebral column resection (PVCR) has extended the treatment of severe spinal deformity. However, the practice guidelines for anterior column support in patients treated by PVCR remain ill defined. The objective of the present study was to compare the clinical and radiographic outcomes of severe thoracic spinal deformity treated by PVCR with and without anterior column support (ACS). Methods We performed a prospective study of 57 patients with severe thoracic deformity (classified as Yang's A type) treated by PVCR with or without anterior column support from January 2010 to April 2015. The patient characteristics, radiographic parameters, intraoperative data, and complications were analyzed to clarify these 2 clinical series. Results The sex, age, diagnosis, curve magnitude, and curve type were similar between the PVCR with ACS group (n = 21) and non-ACS group (n = 36) preoperatively. Evaluation of the radiographic parameters, intraoperative data, and complications found no statistically significant intergroup differences, except for the osteotomy distance (non-ACS group, 4.0 cm; ACS group, 5.3 cm; P < 0.001) and shortening distance of the osteotomy gap (non-ACS group, 4.0 cm; ACS group, 3.5 cm; P = 0.005). Conclusions The results of the present study have shown that PVCR without ACS seems to be a safe and effective technique for Yang's A type severe thoracic spinal deformity correction compared with PVCR with ACS. PVCR without ACS requires a relatively smaller osteotomy range and could potentially decrease the risk of implant failure due to bone to bone fusion. Highlights • Non-ACS group with 4.0-cm osteotomy gap shortening is safe and effective for Yang's type A severe thoracic spinal deformity. • The osteotomy range can be effectively decreased using the non-ACS technique compared with the ACS technique. • The non-ACS technique can potentially decrease the risk of implant failure owing to bone to bone fusion. [ABSTRACT FROM AUTHOR]

In this paper, the large signal operation of the ring oscillator based injection locked frequency divider is analyzed considering the trade-offs among the operating frequency, locking range and power consumption. A large signal model is used to reveal several key findings such as voltage-limited locking ranges and asymmetry between the upper and lower locking bands. They are applied to the optimize the dividers maintaining a good balance among design considerations. Several prototypes, including the divide-by-2 with 3 and 5 stages of inverters, divide-by-3 and divide-by-5, are implemented in a standard 0.18 µm CMOS technology to verify the operation under a large injected signal. As an extension, dual-modulus prescalers are further designed by the integration of switches for different ways of signal mixing. Measurements results show the proposed divide-by-2/3 unit and a divide-by-8/9 with this unit are able to work up to 8 GHz and 4.0 GHz with maximum power consumption of 0.7 mW and 1.5 mW respectively. [ABSTRACT FROM AUTHOR]

Canine mammary tumors (CMTs) are the most common type of tumors in female dogs. Heat shock proteins are highly expressed in many cancers and are involved in tumor progression and chemoresistance in CMTs; however, the biological role of canine heat shock protein 27 (cHSP27) in CMTs has not been thoroughly characterized. This study investigated the roles of cHSP27 in cell growth, migration, anchorage, and resistance to doxorubicin (DOX) using DTK-F cells, a CMT cell line that does not express cHSP27. DTK-F cells were transfected with cHSP27 and stable overexpression was established. A mouse monoclonal antibody against cHSP27 was also produced. The biological functions of cHSP27 in DTK-F cells were then evaluated using a variety of assays. Overexpression of cHSP27 was associated with increased cell proliferation, clone formation, migration, and decreased DOX sensitivity. In conclusion, these data provide evidence that cHSP27 overexpression can promote anchorage-independent growth, migration, and increased DOX resistance in CMT cells. [ABSTRACT FROM AUTHOR]

Local anesthetics have been reported to induce apoptosis in various cell lines. In this study, we showed that bupivacaine also induced apoptosis in DTK-SME cells, a vimentin+/AE1+/CK7+/HSP27+, tumorigenic, immortalized, canine mammary tumor cell line. Bupivacaine induced apoptosis in DTK-SME cells in a time- and concentration-dependent manner. Apoptosis-associated morphological changes, including cell shrinkage and rounding, chromatin condensation, and formation of apoptotic bodies, were observed in the bupivacaine-treated DTK-SME cells. Apoptosis was further confirmed with annexin V staining, TUNEL staining, and DNA laddering assays. At the molecular level, the activation of caspases-3, -8, and -9 corresponded well to the degree of DNA fragmentation triggered by bupivacaine. We also demonstrated that the pan-caspase inhibitor, z-VAD-fmk, only partially inhibited the apoptosis induced by bupivacaine. Moreover, treated cells increased expression of endonuclease G, a death effector that acts independently of caspases. Our data suggested that bupivacaine-induced apoptosis occurs through both caspasedependent and caspase-independent apoptotic pathways. [ABSTRACT FROM AUTHOR]

Abstract: We examined the ac transport attribute of the multi-terminal structures in the absence and presence of magnetic field. We found that the ac response depends on the structural configurations and that the admittance varies with the features of the attached nanoribbons. In the vicinity of Dirac point the dc conductance manifests a dip or peak and the imaginary part (emittance) vanishes or not, depending on whether the attached ribbon is semiconductive or metallic. In the presence of magnetic field, the emittance becomes asymmetric reflecting the dynamic behaviors of electron and hole. [Copyright &y& Elsevier]

Abstract: Phonon transport in the uniform, dimer, Fibonacci and random atomic chains has been comparatively examined using the nonequilibrium atomistic Green''s function method, with particular focus on the interface effects. The tapered and the flat contact to the heat reservoir are compared. It is found that the thermal conductance of the atomic chain depends on both the order degree of the atomic chain structure and the interface configuration. The flat contact is found to favor phonon transmission between the reservoirs and the effect depends on the atomic chain structure as well. [Copyright &y& Elsevier]

Multimodal intraoperative neuromonitoring (IONM) has been proposed as an effective way to reduce permanent neurologic injury during spinal deformity surgery. However, few studies have reported evoked potential changes at different surgical stages of thoracic posterior vertebral column resection (PVCR). A total of 82 cases with severe thoracic deformity (Yang's A type) treated by PVCR in a single institution between January 2010 and March 2015 were reviewed. Multimodal IONM including somatosensory evoked potential, motor evoked potential, and descending neurogenic evoked potential was performed for real-time assessment of spinal cord function during surgery. The risk factors of neuromonitoring events at different surgical stages were documented and analyzed. Multimodal IONM was successfully performed in all 82 cases. Thirty-nine neuromonitoring events presented in 27 (32.9%) cases. Neurologic monitoring events were more likely to occur in patients with larger scoliosis and kyphosis, longer osteotomy closure distance, more Halo gravity traction, more screw insertion, and higher PVCR segments. The reasons for monitoring changes included 6 events during screw insertion, 20 during osteotomy, 9 during osteotomy gap closure, and 4 during deformity correction. New postoperative neurologic deficits were observed in 11 (13.4%) cases including 1 incomplete paraplegia, 8 transient cord deficits, and 2 nerve root injuries. Multimodal IONM can effectively identify neurologic deficits throughout surgery. Osteotomy and osteotomy gap closure are the surgical stages with the highest neurologic risks during PVCR procedures. It is imperative to improve dexterity since the majority of neuromonitoring events are caused by surgical techniques. [ABSTRACT FROM AUTHOR]