Design of size-tunable molecularly imprinted polymer for selective adsorption of acetaminophen

Pharmaceutical and personal care products are a broad and diverse group of biologically active compounds which are widely used and unregulated suspected carcinogens. In this study, the fabrication of molecularly imprinting polymer (MIP) particles by precipitation polymerisation were developed to selectively and rapidly capture acetaminophen, a commonly used analgesic and antipyretic drug, by hydrogen and hydrophobic bondings. Methacrylic acid, 3-(trimethoxysilyl) propyl methacrylate and 2, 2′-azobis-isobutyronitrile were utilised as the functional monomer, cross-linker and initiator. Acetonitrile was found to be the optimised porogen to obtain imprinted polymers with surface area and pore size of 447.2 m²/g and 3.35 nm. By adjusting the ratio of cross-linker and functional monomer, the particle size of MIPs changed from 177 to 2782 nm when the ratio increased from 0.43 to 12.8. In addition, the adsorption equilibrium of acetaminophen by MIPs can be reached within the first 30 min because of the surface imprinting characteristics and small particle sizes. In addition, the maximum adsorption capacity of acetaminophen and the adsorption constant, well fitted by Langmuir equation, were 0.35 mg/g and 0.045 L/mg. In addition, the MIPs exhibited the excellent selectivity to acetaminophen. The high surface area and adsorption capacity and excellent selectivity make MIPs an ideal tailor-made green material and can open the door to develop the novel technology for adsorption and removal of pharmaceutical and personal care products in the environment.     

The effect of annealing on the structure,magnetic properties and AC heating of CoFe2O4 for biomedical applications

Single and nanosized spinel CoFe₂O₄ phase has been prepared successfully by a simple combination of mechanical milling from a mixture of Fe₂O₃ and Co₃O₄ powder precursors followed by a subsequent annealing. X-ray diffraction analysis reveals that the estimated crystallite size of CoFe₂O₄ increases with increasing temperature but remains at the nanoscale, i.e. 85 nm at 900 °C. Moreover, magnetic measurements show that a great enhancement in the saturation magnetization was achieved whereas a large hysteresis loop was observed (i.e.72 emu/g at 900 °C). Evaluation and applicability of CoFe₂O₄ nanoparticles under high frequency AC magnetic field for heating in biomedical applications were examined. It was found that under fixed amplitude (516 Oe) and frequency (229 kHz), the prepared nanoparticles generate significant heat: after 5 s the temperature was around 97 °C for the as-milled powder and reached almost 178 °C for the powder annealed at 900 °C.     

Development of constant-power driving control for light-emitting-diode (LED) luminaire

The illumination of an LED may be affected by operating temperature even under constant-current condition. A constant-power driving technique is proposed in the present study for LED luminaire. A linear system dynamics model of LED luminaire is first derived and used in the design of the feedback control system. The PI controller was designed and tuned taking into account the control accuracy and robust properties with respect to plant uncertainty and variation of operating conditions. The control system was implemented on a microprocessor and used to control a 150W LED luminaire. The test result shows that the feedback system accurately controls the input power of LED luminaire to within 1.3 per cent error. As the ambient temperature changes from 0 to 40 °C, the LED illumination varies slightly (?1.7%) for constant-power driving, as compared to that of constant-current driving (?12%) and constant-voltage driving (+50%). The constant-power driving has revealed advantage in stabilizing the illumination of LED under large temperature variation.     

极致风景——香港丽思卡尔顿酒店

香港丽思卡尔顿酒店位处全球第四高的环球贸易广场之中，占据了其中102至118层，取代上海环球金融中心中的柏悦酒店，成为目前全球最高的酒店。酒店内设有6间高级餐厅和酒廊，包括中莱厅、意大利餐厅、大堂酒廊、茶吧和顶层酒吧，宾客尽情享用顶级美食之余，更可将香港城市景观尽收眼底。同时，从商务客房到各种套房，不同的规格也满足了宾...     

Effect of Gaseous Ozone on Papaya Anthracnose

Anthracnose caused by the fungus Colletotrichum gloeosporioides is considered as one of the most devastating postharvest disease of papaya. The aim of this study was to evaluate the effectiveness of gaseous ozone as a potential antifungal preservation technique to overcome anthracnose disease of papaya during cold storage. Different concentrations of ozone (0 (control), 0.04, 1.6, and 4 ppm) were applied for various exposure durations (48, 96, and 144 h). Radial mycelia growth and conidial germination were evaluated in vitro after fungal exposure to the different levels and durations of ozone. Significant inhibition in radial mycelia growth of C. gloeosporioides was observed (p?<?0.05) in all ozone treatments as compared to the control during 8 days of incubation at room temperature (25?±?3 °C). Ozone treatment of papaya fruit with 1.6-ppm ozone for 96 h delayed and simultaneously decreased the disease incidence to 40 % whereas disease severity was rated at 1.7, following 28 days of storage at 12?±?1 °C and 80 % relative humidity. The scanning electron microscopy showed that 4-ppm ozone caused disintegration of spore structure and did not affect the cuticular surface of fruit. Thus, ozone fumigation can reduce postharvest losses of papaya caused by anthracnose.     

Robot programming using augmented reality: An interactive method for planning collision-free paths

Current robot programming approaches lack the intuitiveness required for quick and simple applications. As new robotic applications are being identified, there is a greater need to be able to programme robots safely and quickly. This paper discusses the use of an augmented reality (AR) environment for facilitating intuitive robot programming, and presents a novel methodology for planning collision-free paths for an n-d.o.f. (degree-of-freedom) manipulator in a 3D AR environment. The methodology is interactive because the human is involved in defining the free space or collision-free volume (CFV), and selecting the start and goal configurations. The methodology uses a heuristic beam search algorithm to generate the paths. A number of possible scenarios are discussed.     

Temperature Modulation Measurements of the Thermal Properties of Nanosystems at Low Temperatures

We report on the dynamic measurements of thermal properties of nanosystems at very low temperatures. These techniques are based on the modulation of the temperature and hence leads to highly sensitive measurements. We will discuss the intrinsic limitations of these methods when the thermal properties of nano-objects are studied at very low temperatures, much below 1 K. Firstly, we will present thermal conductance measurements using the 3ω method. This technique is limited at low temperatures due to the significant increase of the mean free path. Secondly, heat capacity measurements using ac calorimetry are outlined, and again restrictions occur due to the continuous temperature gradient inherent to that technique. Propositions are made in order to overcome these limitations.     

In vivo evaluation of modified titanium implant surfaces produced using a hybrid plasma spraying processing

In this study, the biological responses to surface-modified titanium (Ti) was investigated using a dog model. Titanium plasma spraying and ion implantation of amino (NH₂⁺) groups were used as means of modifying Ti surfaces. Characterization of the modified Ti surfaces was performed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning Auger electron spectroscopy. In vivo evaluations were performed using fluorescence microscope, scanning electron microscope and energy disperse spectroscopy. It was observed in this study that ion-implanted porous-graded titanium coatings had a thick surface oxide layer, containing a small amount of nitride. In vivo study indicates direct bone contact between surface-modified Ti implants and osseous tissues. In addition, osseous tissues were observed to grow into the pores inside the coatings, thereby allowing the formation of a gradual calcium phosphate interface layer. It was concluded from this study that ion implantation of Ti surfaces with amino groups, induced higher concentration of calcium and phosphorus precipitation and more mineralization as compared to non-ion-implanted Ti surfaces.     

Variability in blood flow and pO2 in tumors in response to carbogen breathing

PURPOSE: There is speculation that the CO2 in carbogen (95% O2, 5% CO2) can block the vasoconstrictive effects of oxygen. However, it has recently been shown that blood flow in human tumors is variable while patients breathe carbogen. Furthermore, we have shown a consistent decrease in tumor blood flow (TBF) with carbogen breathing in the rat window chamber model. Also, we have previously shown that there is no significant difference in tumor growth time after radiation with air vs. carbogen breathing. This study was designed to investigate the effects of carbogen breathing on blood flow and oxygen levels in a solid tumor. METHODS: Measurements were made in Fischer-344 rats with 8-10 mm diameter R3230Ac tumors transplanted either within the quadriceps muscle (n = 16) or subcutis (n = 14). Nontumor-bearing quadriceps muscle was studied in six other rats. After a 20-minute air-breathing baseline, rats breathed carbogen for an additional 40 minutes. Partial pressure of oxygen (pO2) was continuously monitored at one position for 60 minutes using 9-12 microm diameter oxygen microelectrodes. Blood flow was simultaneously monitored in all animals using laser Doppler flowmetry (1-2 probes/tumor). RESULTS: Blood flow changes during carbogen breathing were variable in all tissues and intratumoral heterogeneity was observed. Despite variability in blood flow, pO2 consistently increased in normal muscle but varied in both tumor sites. During carbogen breathing, the percent pO2 measurements greater than the baseline average were 99.5% +/- 0.4% (mean +/- SEM), 42.7% +/- 13.8%, and 79.8% +/- 11.0% in normal muscle, subcutaneous tumor, and muscle tumor, respectively. To show the magnitude of change, average pO2 values during air and carbogen breathing were calculated for each site. Normal muscle increased from 14.9 +/- 2.3 to 39.0 +/- 6.4 mm Hg (paired t-test; p = 0.009). Muscle tumors showed a rise from 14.6 +/- 3.2 to 34.5 +/- 8.2 mm Hg (p = 0.019). However, pO2 in subcutaneous tumors remained unchanged, with a pO2 of 7.3 +/- 2.0 mm Hg on air and 7.3 +/- 4.1 mm Hg (p = 0.995) during carbogen breathing. CONCLUSIONS: Carbogen had no consistent effect on blood flow and was ineffective at increasing tumor pO2. These results may partially explain why carbogen breathing failed to improve the efficacy of radiation in this tumor model when transplanted subcutaneously.     

Autofocusing for tissue microscopy

This paper describes the implementation of autofocusing for tissue microscopy. We first investigate the suitability of several criterion functions for the evaluation of image sharpness. Since tissue sections are invariably stained, we also discuss the selection of the colour component on which autofocusing will be performed. In tissue microscopy, where a section generally comprises multiple layers, it is often not possible to obtain an image that is well focused over the field of view because of the limited depth of field of the objective. We describe focus enhancement algorithms, closely related to the autofocus system, which may be employed to obtain an entirely sharp image.