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Hydroxyphenyl-pyranoanthocyanins (PACNs), derived from anthocyanins (ACNs) reacted with hydroxycinnamic acids, have higher practical application value because of better physicochemical stability than their precursors. However, the slow formation rate restricted their broader applications. In the present study, cyanidin-3-O-glucoside (C3G) was chosen to react with four kinds of hydroxycinnamic acids in a model solution. Changes of color and the production of hydroxyphenyl-PACNs were monitored. The formation of derivatives was time-dependent, and the orange-yellow changing trend was correlated with the formation of PACNs and the consumption of C3G. In addition, high-pressure processing (HPP) as a widely-used non-thermal processing method in the food industry was conducted to investigate its impact on hydroxyphenyl-PACNs formation. The results showed that HPP significantly improves the yield of two types of hydroxyphenyl-PACNs (C3G-4-vinylcatechol and C3G-4-vinylphenol) and the retention of total residual pigments during 56 days of storage. Therefore, HPP contributed to color-protecting and the transformation of hydroxyphenyl-PACNs.

Anthocyanins contribute to the attractive color of fruit wine, and their excessive degradation is deleterious to quality, especially for wine with an inherently low anthocyanin content, such as Sanhua plum wine. Ultrasonic treatment is well recognized for wine color maintenance. In the present study, fresh Sanhua plum wine was ultrasonic-treated and aged in barrels for three months. Our results demonstrate that ultrasonic treatment at 28 and 40 kHz improves color performance, as expressed by an increase in a*, b*, and C* values and color intensity, which is highly related to copigmentation. This successful conservation was attributed to the inactivation of polyphenol oxidase and the corresponding reduction in anthocyanin degradation. Finally, the increased antioxidative ability was verified due to the hydrogen donating ability of the surviving anthocyanins. This study indicates the reliability of ultrasonic treatment for providing superior colorfastness during Sanhua plum wine aging, which is also of great potential in processing different fruit wines.

In this study, eight different levels of commercial blueberry wines were studied to establish the comprehensive quality evaluation method of blueberry wine. Eleven physicochemical indexes (total carbohydrates (TC), total acids (TA), total esters (TE), total phenols (TP), total anthocyanins (ANT), color density (CD), tint (T), alcohol by volume (ABV), total soluble solids (TSS), Ph value, total dry extracts (TDE)) were used to establish the quality evaluation model and conduct the principal component analysis (PCA). Based on the results from PCA, the first three principal components accounted for 85.73% of the total quality variability. The consistent ranking of blueberry wines between quality evaluation model and sensory evaluation test verified the reliability of this model. In addition, ultrasonic-treated blueberry wine showed a higher score than the untreated group, which reflected the sensory quality changes of blueberry wine during ultrasonic treatment with high sensitivity. This study provides a theoretical basis for the comprehensive quality evaluation of blueberry wines and reasonable instruction for consumers' choices.

We report the synthesis, characterization, and reactivities of two stable NiIII N-confused porphyrin (NCP) complexes. Metalation of 3-OEt NCP 1 with NiCl2 ⋅ 6H2 O in CHCl3 /EtOH gave 3-OEt NiII NCP 3 initially, which was easily oxidized in air to form the NiIII complex of NCP inner C-oxide 4. Bis-ethoxy-modified NiIII complex 5 was synthesized by oxidation of 3 with PIFA in ethanol and CHCl3 . The structures of 4 and 5 were determined by single-crystal X-ray diffraction analysis. An unusually long NiIII -C bond (2.170(9) A) was observed in 4. The g-factor (g>2.1) observed in the EPR spectra of 4 and 5 further confirmed that they are paramagnetic NiIII complexes. Comparative experiments showed that the 3-ethoxy group plays an important role in the formation of 4 and 5. Reduction of 4 and 5 with NaBH4 regenerated complex 3.

We report the synthesis, characterization, and reactivities of two stable Ni

Anthocyanin accounts for wine color performance, while it is susceptive to saccharomyces cerevisiae, causing threatened stability. Considering pyranoanthocyanin performed better color and stability, converting anthocyanins to pyranoanthocyanins in advance during fermentation was an ideal way for color improvement. Thus, pyruvic acid (PA) as the precursor of vitisin A was applied to fermentation with cyanidin-3-O-glucoside (C3G). Results showed that PA-stress leads to a color loss associated with a decrease in C3G and cyanidin. However, the content of pyranoanthocyanins under PA stress is unvaried. LC-MS-based non-target metabolomics revealed that superfluous PA can disturb the process of glycolysis and tricarboxylic acid cycle. Importantly, 1291 molecular features were increased and 1122 were decreased under PA-stress, in which several anthocyanins derivatization and isomerization were changed, contributing to color performance. This study indicated that extra PA is unfriendly to anthocyanins during fermentation, playing an adverse effect on color, which should be avoided in wine production.

A scheme of closed-loop distribution network by a midvoltage flexible high-temperature superconducting (HTS) dc system is proposed and analyzed. This midvoltage (10-kV) scheme is compared, in terms of capital costs, with that of the closed-loop distribution network by a high-voltage (110-kV) flexible conventional dc system. Based on the HTS cables that are made of the first-generation Bi2223 tapes with a length of 2.5 km, the total investment cost of the 10-kV flexible superconducting dc system with a power capacity of 42 MVA is estimated about 1% lower than that of the 110-kV flexible conventional dc system with the same power capacity, owing to the substantial cost reduction of the voltage-source converter stations with the reduced voltage level. According to the “N - 1” principle of distribution networks, with the interconnecting flexible HTS dc system of 42 MVA, the total power to supply loads of the connected substations can be increased by the same power capacity of the interconnecting system. The simulation results of a three-phase short-circuit fault reveal that the voltage recovery time of the critical loads in the closed-loop distribution network can be reduced to less than 0.1 s, which is much faster than that in open-loop distribution networks.

Core competence is important for high-risk and high-demand operating room nurses, while there are few reports on the core competence of operating room nurses and its influencing factors. This study was to investigate the core competence of nurses in operating room and to explore the effect of fixed surgery specialty on their core competence. The Competency Inventory for Registered Nurses scale, which includes 7 dimensions consisting of a total of 58 items, including ethics/legal practice, professional development ability, leadership ability, clinical nursing ability, interpersonal relationship ability, education/counseling ability and critical thinking/scientific research ability, was used to evaluate the core competence of nurses. Based on the core competence scale of registered nurses, the specific items of core competence of nurses in 5 operating rooms were added to investigate 408 operating room nurses in 8 Grade 3A hospitals in Guangzhou. The total average score of core competence of nurses in operating room was (2.80±0.54). The scores of core competence of nurses in fixed surgery specialty were higher than that in unfixed surgery specialty group (P

This paper presents a method to analyze the dynamic physical limits of a phase-shifted full bridge (PSFB) circuit used for the power supply of Magnetic Resonance Imaging (MRI) gradient amplifiers. Based on the time-optimal control theory, the detailed optimal transient response process under a sudden load current change is analyzed considering the sample time delay, the minimum voltage undershoot and the minimum recovery time are calculated. The analytic results are validated by simulations and experiments on a 120 V/30 A PSFB converter.

This paper presents a method for evaluations and measurements of a high frequency nanocrystalline core transformer for power converters. An experimental platform is set up to measure the B-H characteristics of the core and the performances of the transformer with a frequency range up to 100 kHz. Using the measured B-H characteristics, a 3D FEM model of the transformer is built to simulate the performances and calculate the equivalent circuit parameters of the transformer that will be verified by the experimental data. The results show that the B-H characteristics of the nanocrystalline core are non-linear with frequency but well linear before it starts to saturation at a magnetic field of 0.6∼0.8 T depending on the frequency. The linear relative permeabilities of the core are as high as around 20000 at room temperature, and the iron losses are so low that the efficiencies of the transformer are kept over 99% in the frequency range of under 100 kHz and with a magnetic field within 0.66 T.

To investigate the clinical characteristics and therapeutic effects of vitrectomy in patients with perforating eye injuries with foreign bodies at the exit wound in the posterior global wall.Fifty-two cases, diagnosed with perforating eye injury with foreign bodies at the exit of the posterior global wall and admitted to our hospital between June 2010 and June 2013, were enrolled in this study. All patients underwent vitrectomy and removal of intraocular foreign bodies and were followed up for 6 to 24 months. The causes of injuries were analyzed and postoperative visual acuity and overall treatment efficacy were evaluated.Intraocular foreign bodies were successfully removed in all cases. The incidence of postoperative complication was low. Among 52 subjects, 46 showed alleviated symptoms after treatment with an overall efficacy of 88.46%.Perforating eye injuries combined with residual foreign bodies in the posterior global wall are commonly observed in young people who perform physical labor. Vitrectomy has a high efficacy for the treatment of perforating eye injuries complicated with foreign bodies located at the posterior global wall, with a low incidence of postoperative complications.

This paper presents a capacitor voltage balancing method for the five-level active neutral-point clamped (5L-ANPC) converter using phase-shifted pulse-width modulation (PS-PWM), including the voltage balancing of DC-link capacitors and flying capacitors. With PS-PWM, the series connected switches are operated at fundamental frequency and the other switches are operated at a constant switching frequency. The relationship between the average neutral-point current and zero-sequence voltage is investigated and an optimum zero-sequence voltage can be calculated to regulate the neutral-point potential. The voltage across the flying capacitor is regulated by adjusting the switching duty cycles of two PWM signals, which varies the operation time of redundant switching states in each switching period. Simulation and experimental results are presented to verify the validity of this method.

In this paper, a new five-level hybrid-clamped inverter topology is introduced; this topology adopts a flying capacitor based active-clamped structure. Currents through dc-link neutral points and flying capacitor are studied; decoupling control for capacitor voltages is discussed. A voltage balancing algorithm based on redundant switching combination selection is proposed, the implementation of the algorithm adopts a self-adapting approach simply using PI regulators. Some simulation results are presented to validate the algorithm.