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The objective of our study was to establish and verify a novel combined model based on multiparameter magnetic resonance imaging (MRI) radiomics and clinical features to distinguish intraspinal schwannomas from meningiomas. This research analyzed the preoperative magnetic resonance (MR) images and clinical characteristics of 209 patients with intraspinal tumors who received tumor resection at three institutions. 159 individuals from institutions 1 and 2 were randomly assigned into a training group (n=111) and a test group (n=48) in a 7–3 ratio. A nomogram was constructed using the training cohort and was internally and externally verified in the test cohort and an independent validation cohort (n=50). Model performance was assessed utilizing the area under the curve (AUC) of receiver operating characteristics (ROC), decision curve analysis (DCA), and calibration curves. The nomogram exhibited superior predictive efficacy in distinguishing between spinal schwannomas and meningiomas when compared to both the radiomics model and the clinical model. The nomogram yielded AUCs of 0.994, 0.962, and 0.949 in the training, test, and external validation cohorts, respectively, indicating its exceptional differentiating ability. The DCAs demonstrated that the nomogram yielded the best net benefit. The calibration curves indicated that the nomogram got good agreement between the predicted and the actual observation. This research suggests that the nomogram incorporating clinical and radiomic features may be an effective auxiliary tool for distinguishing between intraspinal schwannomas and meningiomas, and has important clinical significance for clinical decision-making and prognosis prediction. • A nomogram can accurately differentiate intraspinal schwannomas from meningiomas. • The nomogram is helpful for clinicians to make correct treatment decisions. • An independent cohort is used to prove the generalization and validity of the model. [ABSTRACT FROM AUTHOR]

The development of electrocaloric materials (ECMs) with strong electrocaloric effect (ECE) in recent years offers a great opportunity for the development of solid-state heat pumps without using environmentally unfriendly vapor-based technologies. Currently existing ECE-based heat pumps (CEHPs) use one ECM layer that has to be moved back and forth between the thermal source (SO) and sink (SI), which raises reliability and safety concerns. Here, a design, which uses two layers of an ECM and the electric field on each layer is independently controlled with a special pattern, is introduced to develop ECE-based heat pumps with a high cooling power. In the design, the two ECM layers are permanently bound together and used as a single ECM module. The performance of the heat pumps is calculated using the newly introduced analytical solutions. First of all, it is found that the cooling power of CEHPs is strongly dependent on, while the cooling power of heat pumps using the two-ECM-layers module (TELM) is insensitive to, the materials used as the SO/SI. This would significantly expand the application of ECE-based heat pumps since in many applications there is no freedom to choose the materials to be used as the SO/SI. Secondly, the heat pumps using the TELM exhibit a high cooling power. For example, when different materials are used as the SO/SI, the cooling power of CEHPs would be changed over more than 100 times, while it is only changed less than 2 times when the TELM is used to replace the ECM layer used in CEHPs. And the cooling power of heat pumps using the TELM can be more than 7 times higher than the highest cooling power obtained in CEHPs. More importantly, the TELM can be permanently bound to the SO (or the SI) (i.e., the ECM is not moved at all during the operation), which would result in a high reliability. In this case, the cooling power of the heat pumps using the TELM can only be changed less than 25 % when different materials are used as the SO/SI and this cooling power is close to the highest cooling power obtained in the CEHPs. [Display omitted] • Two independently-controlled layers of an electrocaloric material are permanently bonded together as an ECE module. • When the ECE module is used to replace the ECM in current designs the cooling power is enhance more than 7 times. • When the module is permanently bonded to the SO/SI, the cooling power is ∼ 80 % of highest in current designs. • The high cooling power obtained in designs using the ECE module is insensitive to the materials used as the SO/SI. [ABSTRACT FROM AUTHOR]

An all-organic composite system using newly developed PPy nanoclips is developed. The composites have a uniform microstructure due to the unique preparation process. The composites have a very low percolation threshold (<8 wt%) and exhibit a high dielectric constant. At room temperature, the composites exhibit a dielectric constant of more than 1000. At temperatures higher than 98 °C, the composites exhibit a dielectric constant of about 2000. More interestingly, the high dielectric constant reported here is associated with a loss much smaller than the loss reported for other CDCs using 1-D fillers. It is indicated that a new dielectric relaxation process is induced due to the mixture of PPy with P(VDF-TrFE), whose relaxation time decreases with increasing PPy content. The loss observed in the composites at low temperature including room temperature is mainly determined by this relaxation process rather than the conductivity. If this relaxation process has a strong contribution to the dielectric constant, the widely used percolation formula describing relationship between the dielectric constant and the composite cannot be used. [ABSTRACT FROM AUTHOR]

GABA B receptors associate with G i/o -proteins that regulate voltage-gated Ca 2+ channels and thus the intracellular Ca 2+ concentration ([Ca 2+ ]i), there is also reported cross-regulation of phospholipase C. These associations have been studied extensively in the brain and also shown to occur in non-neural cells (e.g. human airway smooth muscle). More recently GABA B receptors have been observed in chick retinal pigment epithelium (RPE). The aims were to investigate whether the GABA B receptor subunits, GABA B1 and GABA B2 , are co-expressed in cultured human RPE cells, and then determine if the GABA B receptor similarly regulates the [Ca 2+ ]i of RPE cells and if phospholipase C is involved. Human RPE cells were cultured from five donor eye cups. Evidence for GABA B1 and GABA B2 mRNAs and proteins in the RPE cell cultures was investigated using real time polymerase chain reaction, western blots and immunofluorescence. The effects of the GABA B receptor agonist baclofen, antagonist CGP46381, a G i/o -protein inhibitor pertussis toxin, and the phospholipase C inhibitor U73122 on [Ca 2+ ]i in cultured human RPE were demonstrated using Fluo-3. Both GABA B1 and GABA B2 mRNA and protein were identified in cell cultures of human RPE; antibody staining was co-localized to the cell membrane and cytoplasm. One-hundred micromolars of baclofen caused a transient increase in the [Ca 2+ ]i of RPE cells regardless of whether Ca 2+ was added to the buffer. Baclofen-induced increases in the [Ca 2+ ]i were attenuated by pre-treatment with CGP46381, pertussis toxin, and U73122. GABA B1 and GABA B2 are co-expressed in cell cultures of human RPE. GABA B receptors in RPE regulate the [Ca 2+ ]i via a G i/o -protein and phospholipase C pathway. [ABSTRACT FROM AUTHOR]

To overcome the low discharging efficiency of ceramic-polymer composites using ferroelectric polymers as matrix and to take the advantage in fabrication offered by the polar polymer, a polar but non-ferroelectric polymer – poly(methyl methacrylate) (PMMA) – was selected as the matrix in the development of high performance composites for energy storage. Ba 0.5 Sr 0.5 TiO 3 (BST) nanoparticles were selected as the filler. Freestanding and flexible BST-PMMA ceramic-polymer nanocomposites with BST content up to 30 vol.% were fabricated in thickness of about 5 μm using spin-coating process and were systemically studied. Due to the strong interaction between the polar groups of PMMA and the hydroxyl groups on the surface of BST nanoparticles, the suspension of BST nanoparticles in PMMA solution exhibits excellent stability and, hence, the nanocomposite films have excellent microstructure uniformity and compatibility between the BST nanoparticles and PMMA matrix. All the BST-PMMA films exhibit excellent frequency (100 Hz to 1 MHz) and temperature (−90 to 100 °C) stabilities in their dielectric properties with a high energy-storage density of more than 11 J/cm3. Most importantly, an ultra-high discharging efficiency of almost 100% is obtained in all the nanocomposites. Image 1 • Non-ferroelectric polar polymer is introduced as matrix for the nanocomposites used as energy-storage dielectrics. • High energy density with ultrahigh discharging efficiency (~100%) are demonstrated by BST-PMMA nanocomposite films. • The BST-PMMA nanocomposite films exhibit excellent temperature and frequency stabilities of dielectric properties. [ABSTRACT FROM AUTHOR]

Whereas activation of α 1 -adrenoceptors (α 1 -ARs) modulates glutamatergic transmission, the roles of α 1 -ARs in GABAergic transmission in the medial prefrontal cortex (mPFC) are elusive. Here, we examined the effects of the α 1 -AR agonist phenylephrine (Phe) on GABAergic transmission onto pyramidal neurons in the deep layers of the mPFC. We found that bath application of Phe dose-dependently increased the amplitude of evoked IPSCs (eIPSCs). Phe increased the frequency but not the amplitude of miniature IPSCs (mIPSCs). Ca 2+ influx through T-type voltage-gated calcium channels is required for Phe-induced increases in GABA release. Phe increases GABA release probability and the number of releasable vesicles. Phe depolarizes the fast-spiking (FS) interneurons without effects on the firing rate of action potentials (APs) of interneurons. Phe-induced depolarization is independent of extracellular Na + , Ca 2+ and T-type calcium channels, but requires inward rectifier K + channels (Kirs). The present study demonstrates that Phe enhances GABAergic transmission onto mPFC pyramidal neurons through inhibiting interneurons Kirs, which further depolarizes interneurons leading to increase in Ca 2+ influx via T-type calcium channels. Our results may provide a cellular and molecular mechanism that helps explain α 1 -AR-induced PFC dysfunction. [ABSTRACT FROM AUTHOR]

Abstract: Electric fatigue tests were carried out on [001]-oriented (PMN–0.32PT) single crystals at different electric fields: lower and higher than the coercive field. For the crystals fatigued at low (1.5 kV/cm) electric field, the polarization fatigue and piezoelectric constant degradation are weak (<20%) and can be easily removed by thermal annealing, and it is found that the fatigue behavior is mainly due to the phase transition and the introduction of intermediate phase(s) during the fatigue process. For the crystals fatigued at high (7.5 kV/cm) electric field, a severe fatigue behavior (∼40%) is observed in the polarization, and the piezoelectric constant and the fatigue are difficult to eliminate by thermal annealing. It is believed that for the samples fatigued at high electric field, besides the contribution of the phase transition and the introduction of intermediate phase(s) during fatigue, domain wall pinning is the key contribution to the observed severe fatigue behavior. It is also found that the fatigue causes the crystal to have a different strain response: a more gradual response and with a smaller maximum strain response. [Copyright &y& Elsevier]

SiGe-free strained Si on insulator (SSOI) is a new material system that combines the carrier transport advantages of strained Si with the reduced capacitance and improved scalability of thin film silicon on insulator (SOI). We demonstrate fabrication of 20% Ge equivalent strain level SSOI substrates with Si thicknesses of 100 and 400 A˚ by hydrogen-induced layer transfer of strained Si layers from high quality graded SiGe virtual substrates. The substrate properties are excellent: wafer scale strained Si film thickness uniformities are better than 8%, strained Si surface roughnesses are better than 0.5 nm RMS, and robust tensile strain levels are maintained during anneals as long as 80 min at 1100 °C. Fully depleted n-MOSFET electrical results show that biaxial tensile strain, and hence enhanced mobility, is fully maintained in the 400 A˚ 20% SSOI films through the substrate and device fabrication processes, even after a generous FET fabrication thermal budget. Long channel devices exhibit nearly ideal subthreshold slopes of 66 mV/decade and exhibit 112% electron mobility enhancements at Ninv=1×1013 cm−2, identical to devices on bulk strained Si substrates. Furthermore, a photoemission microscopy study was used to confirm that the useable SSOI layer thickness significantly exceeds the critical thickness for fabrication of bulk strained Si FETs without deleterious leakage current effects. The fabrication of epitaxially defined, thin strained Si layers directly on a buried insulator is an ideal platform for future generations of Si-based microelectronics. [Copyright &y& Elsevier]

Nanocomposites using poly (vinylidene fluoride- co -hexafluoropropylene), P(VDF-HFP), as the matrix, and barium strontium titanium oxide (BST) nanoparticles as the filler were systematically studied. P(VDF-HFP)/BST composite films containing different amounts of BST were prepared using the solution-casting method. The dielectric constant (ε r), dielectric loss (tan δ), and their frequency and temperature dependence, were characterised for the films under weak electric fields. The behaviour of the films under high electric fields was explored using polarisation-electric field (P-E) loops. The ε r was found to increase from 14.1 to 42.1 as the BST content increased from 0 vol% to 40 vol%, and the Maxwell-Wagner model showed a good fit with the measured ε r values, indicating that the microstructure of the fabricated nanocomposites is uniform, which can also be observed in SEM images of all P(VDF-HFP)/BST nanocomposite films. In determining the temperature (T) dependence of the ε r and tan δ of the composites, P(VDF-HFP) plays a decisive role, while BST plays an influential role. As the BST content increases, the charge/discharge energy density (U charge / U discharge) increases, while the breakdown strength (E b) and charge-discharge efficiency (η) decrease. Notably, the maximal U discharge 3.79 J/cm3 was obtained when the BST content was 20 vol% at 2100 kV/cm. In addition, from the perspective of practical application, when the applied electric field intensity is lower than 900 kV/cm or between 900 kV/cm and 2100 kV/cm, in order to obtain the maximal U discharge , the P(VDF-HFP)/BST composite with BST content of 30 vol% or 20 vol% should be selected respectively. [ABSTRACT FROM AUTHOR]

In this work, free-standing and flexible polymer-ceramic nanocomposite films were fabricated by a spin-coating process using poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)] as matrix and BaTiO 3 (BTO) nanoparticles as filler. The relationships between the properties and compositions were systematically investigated. It is experimentally found that the crystallinity and the size of crystals of the P(VDF-HFP) matrix decreases with increasing BTO content. The dielectric responses of the polymer used as matrix were determined by four dielectric processes. Both the temperature and frequency dependences of the dielectric responses obtained in the composite films are mainly determined by the polymer matrix, and the influences of the ceramic filler on the four dielectric processes of the polymer matrix were discussed. [ABSTRACT FROM AUTHOR]

Abstract Free-standing and flexible polymer-ceramic composite films were fabricated using P(VDF-CTFE) 91/09 mol.% (VC 91) as polymer matrix and (Pb 0.94 La 0.04)[(Zr 0.56 Sn 0.44) 0.84 Ti 0.16 ]O 3 (PLZST) nanoparticles as ceramic filler. All the VC 91 -PLZST composite films are dense and homogeneous in microstructure, and are flexible with a uniform thickness of about 5 μm. It is experimentally found that as the PLZST content increases, the dielectric constant of the composite films increases, while the dielectric loss decreases. Besides the glass-transition process, there is another relaxation process related to the motion of entire polymer chains of VC 91. These two relaxation processes determine the frequency dependences and temperature dependences of the dielectric properties observed in the composite films. The ac conductivity of the VC 91 -PLZST composite films was investigated at different temperatures and the results indicate that the conductive mechanisms are related to the relaxation processes of the VC 91 matrix at different temperatures and all the VC 91 -PLZST composite films are good insulators. [ABSTRACT FROM AUTHOR]

Abstract All-organic nanocomposites using conducting polypyrrole (PPy) nano-clips as fillers and poly(vinylidene fluoride-chlorotrifluoroethylene) (PVDF-CTFE) as the matrix are studied. The nanocomposites with a uniform microstructure were fabricated via a combination of a solution casting and a hot pressing process. Due to the uniform microstructure, the composites exhibit a single glass transition process, whose temperature decreases with increasing PPy content. The dielectric properties of the nanocomposites are systemically studied and analyzed over a wide temperature range from −60 °C to 140 °C and a broad frequency range from 100 Hz to 1 MHz. The nanocomposites have a low percolation threshold (∼7.4 wt%) and exhibit a high dielectric constant and a low dielectric loss. For the composites with 7 wt% of PPy at room temperature, the dielectric constant at 1 kHz is 23 times higher than that of the polymer matrix and the dielectric loss over a broad frequency range is less than 0.4 which is lower than the loss reported in other composites with the composition close to the percolation threshold. It is concluded that mixing PPy with P(VDF-CTFE) results in a new relaxation process that dominates the observed dielectric loss at low temperatures including room temperature. It is demonstrated that it is the DC conductivity rather than the dielectric constant that should be used to determine the percolation threshold. [ABSTRACT FROM AUTHOR]

CuO was used as an additive in BaTiO 3 -SiO 2 ceramic-glass composites sintered from SiO 2 -coated BaTiO 3 nanoparticles. The effects of the CuO content on the microstructure, phase composition, dielectric property, and energy-storage performance were investigated. The porosity of the composites was obviously reduced by the addition of CuO. All the composites suggested a perovskite phase. The maximal polarization, remnant polarization, and dielectric breakdown strength were strongly dependent on the CuO content. A maximal discharged energy density of 1.43 J/cm 3 with a charge-discharge efficiency of 53% was achieved in the composite with 2.0 mol% CuO, which was enhanced by about 4 times as compared with that of the pure BaTiO 3 -SiO 2 composite. [ABSTRACT FROM AUTHOR]

Ba 0.5 Sr 0.5 TiO 3 (BST) nanoparticles were coated with SiO 2 using a chemical process. SiO 2 -coated BST was used as the starting material to prepare BST- x SiO 2 ( x  = 0, 1.0, 2.0, 3.0, 4.0, and 5.0 wt%) composites via a conventional ceramic process. The influence of SiO 2 on the structure and properties of these composites was systematically studied. Scanning electron microscopy (SEM) results showed that the porosity of the composites was obviously reduced by the addition of SiO 2 . X-ray diffraction (XRD) results indicated that, besides the perovskite phase of BST, a traceable secondary phase of BaTiSiO 5 also existed. The formation of BaTiSiO 5 was due to the reaction between SiO 2 and barium from BST. This resulted in a lower phase transition temperature of BST phase in the composites. It was found that the dielectric constant and loss decreased with increasing SiO 2 content. All the composites exhibited a low dielectric loss (< 0.01) and an almost frequency independent dielectric constant in a frequency range from 100 Hz to 100 kHz. All the composites exhibited a high tunability (> 47%). Although the tunability decreased with increasing SiO 2 content, a higher tunability was achieved in the composites because the composites exhibited a much higher breakdown strength than the pure BST ceramics. Additionally, it was found that the tunability of the composites increased with the decrease of the operating temperature. [ABSTRACT FROM AUTHOR]

This paper presents a piezoelectric-excited membrane device for rapid measurement of liquids viscosity and density. The working principle of the device is based on membrane’s resonant frequency and Q factor responses to the damping effects of a surrounding liquid. The dependences of the resonant frequency and Q factor on liquids viscosity and mass density were theoretically investigated using a sphere-end oscillator model in viscous liquids and compared to experimental results. The theory and experimental results show that the piezoelectric-excited membrane can be used to measure liquids viscosity in a range from 19.88 cP to 1733 cP and mass density in a range from 0.829 g/cm 3 to 0.886 g/cm 3 . Hence, the piezoelectric-excited membrane device is a promising candidate for rapid measurement of liquids viscosity and mass density, especially for wide-range viscosity measurement. [ABSTRACT FROM AUTHOR]

Abstract: Ceramic–polymer 0–3 nanocomposites, in which nanosized Ba0.5Sr0.5TiO3 (BST) powders were used as ceramic filler and P(VDF–CTFE) 88/12mol% [poly(vinylidene fluoride–chlorotrifluoroethylene)] copolymer was used as matrix, were studied over a concentration range from 0 to 50vol.% of BST powders. It is found that the solution cast composites are porous and a hot-press process can eliminate the porosity, which results in a dense composite film. Two different configurations used in the hot-press process are studied. Although there is no clear difference in the uniformity and microstructure of the composites prepared using these two configurations, the composites prepared using one figuration exhibit a higher dielectric constant with a lower loss. For the composite with 40vol.% BST, a dielectric constant of 70 with a loss of 0.07 at 1kHz is obtained at room temperature. The composites exhibit a lower dielectric loss than the polymer matrix at high frequency. However, at low frequency, the composites exhibit a higher loss than the polymer matrix due to a low frequency relaxation process that appears in the composites. It is believed that this relaxation process is related to the interfacial layer formed between BST particle and the polymer matrix. The temperature dependence of the dielectric property of the composites was studied. It is found that the dielectric constant of these composites is almost independent of the temperature over a temperature range from 20 to 120°C. [Copyright &y& Elsevier]

Abstract: Objective: This study sought to describe the surgical management of right portal venous (PV) branches encountered among 104 cases of right lobe living donor liver transplantation (LDLT). Methods: From January 2002 to September 2007, we performed 104 cases of right-lobe LDLT including 11-donors who had anomalous right portal venous branches (APVB). One recipient had PV sponginess hemangioma. The donor right PV branches were type I in 93 cases, type II (trifurcation) in nine cases, and type III in two cases. Except one narrow bridge of tissue excision, the PV branches were transected on the principal of donor priority: PV branches were excised approximately 2 to 3 mm from the confluence while leaving the donor''s main portal vein and confluence intact. In type II APVB, donor PV branches were obtained with two separate openings in six cases; with two separate openings joined as a common orifice at the back table in two cases, with one common opening with a narrow bridge of tissue in one case. In type III APVB, the donor right anterior and posterior PV branches were obtained with separate openings. The donor right PV branches with one common opening in 92 cases of type I PV branches and a joined common orifice in three cases of type II APVB were anastomosed to the recipient''s main portal vein or to right branching. As the unavailable recipient PV for sponginess hemangioma, one case of type I right PV branches was end-to-end anastomosed to one of the variceal lateral veins of about 1 cm diameter in a pediatric patient. The PV were reconstructed as double anastomoses in six type II APVB and in one type III APVB obtained with two separate PV openings. In the another type III APVB reconstruction, we successfully utilized a novel U-shaped vein graft interposition. Results: The type II APVB donor receiving a narrow bridge of portal vein tissue excision developed portal vein thrombosis on the third postoperative day and underwent reexploration for thrombectomy. There were no vascular complications, such as portal vein thrombosis or stricture among other donors or all recipients. The velocity of blood flow in the U-graft was normal. The anastomosis between the type I donor right portal vein and recipient variceal lateral vein was unobstructed. Conclusion: Right PV branches should be excised on the principal of donor priority while leaving the donor''s main portal vein and confluence intact. Single anastomoses was the fundamental procedure of right branch reconstruction. Double anastomoses could be used as the main management for type II and type III APVB reconstruction. U-graft interposition may be a potential procedure for type III APVB reconstruction. Single anastomoses between the donor right portal vein and the recipient variceal lateral vein may be performed when recipient portal vein is unavailable. These innovations for excision and reconstruction of right PV branches were feasible, safe, and had good outcomes. [Copyright &y& Elsevier]

Crystallization behaviors and related dielectric properties of semicrystalline matrix in polymer-ceramic nanocomposites have been systemically investigated by using P(VDF-TrFE) 70/30 mol.% as matrix and Ba 0.5 Sr 0.5 TiO 3 nanoparticles as filler. It is found that due to the presence of ceramic nanofiller, there are two types of crystals formed in the matrix: one formed on the surface of the ceramic nanoparticles and the other formed in the polymer. The former favors the all-trans β phase due to the interaction between matrix chains and ceramic surface. The later has defects that result in two low-temperature phases: the well-ordered β phase and less-ordered β phase (i.e. β′ phase). The conformation defects of the β′ phase result in it a lower dielectric permittivity than β phase. The proportion of β' phase decreases with increasing ceramic content and only β phase can be observed in the nanocomposites with a ceramic content higher than 35 vol%. These results were reflected in and confirmed by the DSC analyses and the dielectric properties. [ABSTRACT FROM AUTHOR]