All polymers exhibited low cytotoxicity and their micelles had a desirable release-acceleration pH (pH 5.0) for cytoplasmic drug delivery. With the introduction of polylactide into the polymer, the micelle critical micelle concentration can be effectively decreased and the drug-loading content was enhanced. Most importantly, the drug resistance of MCF-7/ADR cells was significantly reversed via the interaction between polymer and Pgp. Therefore, this type of polymer has potential superiority for cancer therapy.

Abstract-Linearity testing of analog-to-digital converters (ADCs) can be very challenging because it requires a signal generator substantially more linear than the ADC under test. This paper introduces the stimulus error identification and removal (SEIR) method for accurately testing ADC linearity using signal generators that may be significantly less linear than the device under test. In the SEIR approach, two imprecise nonlinear but functionally related excitations are applied to the ADC input to obtain two sets of ADC output data. The SEIR algorithm then uses the redundant information from the two sets of data to accurately identify the nonlinearity errors in the stimuli. The algorithm then removes the stimulus error from the ADC output data, allowing the ADC nonlinearity to be accurately measured. For a high resolution ADC, the total computation time of the SEIR algorithm is significantly less than the data acquisition time and therefore does not contribute to testing time. The new approach was experimentally validated on production test hardware with a commercial 16-bit successive approximation ADC. Integral nonlinearity test results that are well within the device specification of 2 least significant bits were obtained by using 7-bit linear input signals. This approach provides an enabling technology for cost-effective full-code testing of high precision ADCs in production test and for potential cost-effective chip-level implementation of a built-in self-test capability. Index Terms-Analog-to-digital converters (ADCs), integral nonlinearity (INL), linearity test, stimulus error identification and removal (SEIR).I. BACKGROUND T HE "histogram method" is a standard approach for quasi-static linearity testing of analog-to-digital converters (ADCs) [1]- [3]. However, during the past decade, linearity testing of ADCs has not received much research attention for several reasons. As long as best practices are followed, modern mixed-signal automated test equipment (ATE) can be used to make quasi-static linearity testing of ADCs a fairly straightforward production task for low-to-medium resolution ADCs [4]. High-precision delta-sigma ADCs are inherently sufficiently linear and do not require linearity testing. In the communications circuit area, high-speed pipelined ADCs are widely used and are usually production tested with high-frequency input signals [2], whereas quasi-static linearity testing is primarily used for debugging [5] or calibration [6]. Probably the biggest reason, however, can be attributed to the challenges associated with generating highly linear or spectrally pure test signals with no major technological breakthroughs occurring in this area in the past decade. Nevertheless, quasi-static linearity testing remains a test challenge for the production of certain classes of high performance ADCs, and the increasing downward production cost pressures are making the convenient use of expensive mixed-signal ATEs for testing low and medium resolution ADCs more difficult to justify. In this paper, emphasis ...

These data suggest that the neuroprotective effect of carnosine on rUCCAO in mice is not dependent on the histaminergic pathway, but may be due to a suppression of reactive oxygen species generation, glia activation, and myelin degeneration.

Tissue engineering is a technology that enables us to construct complicated hominine organs composed of many different types of cells. One of the key points to achieve this goal is to control the material composition and porous structure of the scaffold accurately. A disposable syringe based volume-driven injecting (VDI) nozzle was proposed and designed to extrude both natural derived and synthetic polymers. A multinozzle low-temperature deposition and manufacturing (M-LDM) system is proposed to fabricate scaffolds with heterogeneous materials and gradient hierarchical porous structures. PLGA, collagen, gelatin, chitosan can be extruded without leaking to form hierarchical porous scaffolds for primary study. Composite scaffolds with two kinds of materials were fabricated via two different nozzles to get both hydrophilic and mechanical properties. The results from scanning electron microscopy (SEM) demonstrated that the natural-derived biomaterials were strongly absorbed onto the synthetic biomaterials to form a stable network. Several gradient PLGA/TCP scaffolds were also fabricated to supply several samples.

In addition to providing maneuverability, electrospun nanofibrous meshes can make excellent supports for constructing flexible cell sheets to regulate cell behavior by nanofiber features. With the target of bone regeneration, herein composite nanofibers with two different fiber arrangements (nestlike, random) were electrospun from a blend solution containing poly(l-lactide) (PLLA) and gelatin (1:1 in weight ratio). Unlike the non-woven morphology in a random nanofibrous mesh, PLLA/gelatin composite nanofibers in the nestlike nanofibrous mesh displayed both non-woven and parallel morphologies. Both kinds of nanofibrous mesh were ∼50 μm thick as-prepared, and shrank to ∼30 μm after seeding with bone mesenchymal stromal cells (BMSCs). After 7 days of in vitro culture, cell sheets could form on both meshes (CSM) and on the culture plate. It was found that application of nanofibrous mesh promoted the osteogenic differentiation of BMSC sheets compared with the control. The nestlike mesh displayed slight superiority over the random mesh in enhancing osteogenic differentiation, but their different fiber arrangements did not cause much difference in cell proliferation. Three-dimensional multi-layered CSM constructs were built by stacking four mono-layered CSMs together. The CSM constructs (based on a nestlike or random nanofibrous mesh) were incubated in vitro for 3 days before being implanted into rat cranial defects. In comparison with the control group, there was significant formation of new calcified bone in both CSM construct-filled groups at 12 weeks' post-operation. The nestlike group showed slightly better bone healing (based on both qualitative and quantitative analysis) than the random group, while showing insignificant differences. We showed that the concept of using a three-dimensional multi-layered CSM construct in enhancing bone regeneration was feasible. Future studies should take more nanofiber features (e.g. bioactive components) into account to further enhance osteogenesis.

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In this work, a kind of thin K‐type thermocouple and self‐developed CAS‐I sealant were used to assembly solid oxide fuel cell (SOFC) stacks and temperatures of unit cells inside a planar SOFC stack were measured. The open circuit voltage testing of the stack and characterization of the interface between sealant and components suggested excellent sealing effect by applying the developed method. The effect of discharging direct‐current on temperature and temperature distribution inside the designed SOFC stack was investigated. The results showed that the discharging current had a great impact and the gas flow rate had a slight impact on the temperatures of unit cells. Temperature distribution of unit cells inside the stack was much non‐uniform and there is a significant temperature difference between various components of the stack and heating environment. The relationship between temperatures and cell performance showed that the worse the cell performance, the higher the cell surface temperature. When the stack was discharged at a constant current and the temperature of cell surface was over 950 °C, the higher the temperature, the more drop the corresponding voltage.