49 research outputs found

    Characteristics and potential biomarkers of flavor compounds in four Chinese indigenous chicken breeds

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    Chinese indigenous chickens have a long history of natural and artificial selection and are popular for their excellent meat quality and unique flavor. This study investigated six meat quality-related traits in Ningdu yellow, Baier yellow, Kangle, and Shengze 901 chickens. Two-dimensional gas chromatography-time-of-flight mass spectrometry was used to detect unique flavors in 24 breast muscle samples from the same phenotyped chickens. Overall, 685, 618, 502, and 487 volatile organic compounds were identified in Ningdu yellow, Baier yellow, Kangle, and Shengze 901 chickens, respectively. The flavor components were separated into eight categories, including hydrocarbons and aldehydes. Multivariate analyses of the identified flavor components revealed some outstanding features of these breeds. For example, the hydrocarbons (22.09%) and aldehydes (14.76%) were higher in Ningdu yellow chickens and the highest content of N, N-dimethyl-methylamine was in Ningdu yellow, Baier yellow, and Shengze 901 chickens, indicating the maximum attribution to the overall flavor (ROAV = 439.57, 289.21, and 422.80). Furthermore, we found that 27 flavor compounds differed significantly among the four Chinese breeds, including 20 (e.g., 1-octen-3-ol), two (e.g., 2-methyl-naphthalene), four (e.g., 2,6-lutidine), and one (benzophenone) flavor components were showed significant enrichment in Ningdu yellow, Baier yellow, Kangle, and Shengze 901 chickens, respectively. The flavor components enriched in each breed were key biomarkers distinguishing breeds and most were significantly correlated with meat quality trait phenotypes. These results provide novel insights into indigenous Chinese chicken meat flavors

    Biogenic flower-shaped Au-Pd nanoparticles: Synthesis, SERS detection and catalysis towards benzyl alcohol oxidation

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    ~40 nm flower-shaped Au-Pd bimetallic nanoparticles were prepared in a facile and eco-friendly way based on the simultaneous bioreduction of HAuCl 4 and Na2PdCl4 with ascorbic acid and Cacumen Platycladi leaf extract at room temperature. Characterization techniques, such as transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction, were employed to confirm that the as-synthesized nanoparticles were alloys. The obtained flower-shaped Au-Pd alloy nanoparticles exhibited an excellent surface enhanced Raman spectroscopic activity with rhodamine 6G and efficient catalytic ability for the oxidation of benzyl alcohol to benzaldehyde. ? 2014 The Royal Society of Chemistry

    Characterization of the Biosynthesis, Processing and Kinetic Mechanism of Action of the Enzyme Deficient in Mucopolysaccharidosis IIIC

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    Heparin acetyl-CoA:alpha-glucosaminide N-acetyltransferase (N-acetyltransferase, EC 2.3.1.78) is an integral lysosomal membrane protein containing 11 transmembrane domains, encoded by the HGSNAT gene. Deficiencies of N-acetyltransferase lead to mucopolysaccharidosis IIIC. We demonstrate that contrary to a previous report, the N-acetyltransferase signal peptide is co-translationally cleaved and that this event is required for its intracellular transport to the lysosome. While we confirm that the N-acetyltransferase precursor polypeptide is processed in the lysosome into a small amino-terminal alpha- and a larger ß- chain, we further characterize this event by identifying the mature amino-terminus of each chain. We also demonstrate this processing step(s) is not, as previously reported, needed to produce a functional transferase, i.e., the precursor is active. We next optimize the biochemical assay procedure so that it remains linear as N-acetyltransferase is purified or protein-extracts containing N-acetyltransferase are diluted, by the inclusion of negatively charged lipids. We then use this assay to demonstrate that the purified single N-acetyltransferase protein is both necessary and sufficient to express transferase activity, and that N-acetyltransferase functions as a monomer. Finally, the kinetic mechanism of action of purified N-acetyltransferase was evaluated and found to be a random sequential mechanism involving the formation of a ternary complex with its two substrates; i.e., N-acetyltransferase does not operate through a ping-pong mechanism as previously reported. We confirm this conclusion by demonstrating experimentally that no acetylated enzyme intermediate is formed during the reaction

    Microorganism-mediated synthesis of chemically difficult-to-synthesize Au nanohorns with excellent optical properties in the presence of hexadecyltrimethylammonium chloride

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    Fundamental Research Funds for Central Universities [2010121051]; NSFC [21106117, 21036004]Closely packed, size-controllable and stable Au nanohorns (AuNHs) that are difficult to synthesize through pure chemical reduction are facilely synthesized using a microorganism-mediated method in the presence of hexadecyltrimethylammonium chloride (CTAC). The results showed that the size of the as-synthesized AuNHs could be tuned by adjusting the dosage of the Pichia pastoris cells (PPCs). The initial concentrations of CTAC, ascorbic acid (AA) and tetrachloroaurate trihydrate (HAuCl4 center dot 3H(2)O) significantly affected the formation of the AuNHs. Increasing the diameters of AuNHs led to a red shift of the absorbance bands around 700 nm in their UV-vis-NIR spectra. Interestingly, the AuNH/PPC composites exhibited excellent Raman enhancement such that rhodamine 6G with concentration as low as (10(-9) M) could be effectively detected. The formation process of the AuNHs involved the initial binding of the Au ions onto the PPCs with subsequent reduction by AA to form supported Au nanoparticles (AuNPs) based on preferential nucleation and initial anisotropic growth on the platform of the PPCs. The anisotropic growth of these AuNPs, which was influenced by CTAC and PPCs, resulted in the formation of growing AuNHs, while the secondary nucleation beyond the PPCs produced small AuNPs that were subsequently consumed through Ostwald ripening during the aging of the AuNHs. This work exemplifies the fabrication of novel gold nanostructures and stable bio-Au nanocomposites with excellent optical properties by combining microorganisms and a surfactant

    Earliella scabrosa-associated postoperative Endophthalmitis after Phacoemulsification with intraocular lens implantation: a case report

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    Abstract Background Postoperative endophthalmitis after cataract surgery is a severe eye infection that can lead to irreversible blindness in the affected eye. The characteristics, treatment and prognosis of this disease vary because of its association with different pathogens. Here, we report what is possibly the first case of endophthalmitis after cataract surgery to be associated with the rare pathogen Earliella scabrosa. Case presentation A 56-year-old man from Hainan Island (China) with a history of phacoemulsification and type II diabetes mellitus underwent intraocular lens (IOL) implantation. He later presented with progressive endophthalmitis in his right eye. IOL explantation with capsular bag removal and a 23G pars plana vitrectomy combined with a silicone oil tamponade was performed. The infection was cleared without recurrence, and the patient’s visual acuity improved from light perception to 20/200 in the right eye. An in vitro culture determined that the causative pathogen was Earliella scabrosa, and this result was confirmed by an internal transcribed spacer (ITS) sequence analysis. Conclusion Earliella scabrosa has never been reported as an infectious agent in human eyes, and its clinical significance remains unknown. Here, we report a rare case of Earliella scabrosa-associated endophthalmitis after cataract surgery. The fungal infection presented as an acute attack and was successfully treated with vitrectomy

    Contrasting roles of Bi-doping and Bi 2 Te 3 alloying on the thermoelectric performance of SnTe

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    Previous studies have revealed that both Bi doping and Bi2Te3 alloying are successful strategies to optimize the thermoelectric performance of SnTe; however, detailed and thorough investigations on exactly how they differ in modulating the band structure and microstructure were seldom given. Through a systematic comparison between Bi-doped and Bi2Te3-alloyed SnTe, we find in this work that despite the fact that they both contribute to the valence band convergence of SnTe, Bi2Te3 alloying induces little effect on the hole concentration unlike the typical n-type feature of Bi-doping; moreover, Bi2Te3 alloying tends to produce dense dislocation arrays at micron-scale grain boundaries which differs significantly from the substitutional point defect character upon Bi-doping. It was then found that Bi2Te3 alloying exhibits a relatively higher quality factor (B ∼ μw/κlat) at higher temperatures than Bi-doping. Subsequent Ge-doping in Bi2Te3-alloyed samples results in further valence band convergence and hole concentration optimization and eventually results in a maximum figure of merit ZT of 1.4 at 873 K in the composition of (Sn0.88Ge0.12Te)0.97-(BiTe1.5)0.03

    Ultra-fast charge-discharge and high-energy storage performance realized in KNaNbO3-Bi(MnNi)O3 ceramics

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    Lead-free relaxor ceramics (1 − [Formula: see text])K[Formula: see text]Na[Formula: see text]NbO3 − [Formula: see text]Bi(Mn[Formula: see text]Ni[Formula: see text])O3 ((1 − [Formula: see text] )KNN- [Formula: see text]BMN) with considerable charge–discharge characteristics and energy storage properties were prepared by a solid state method. Remarkable, a BMN doping level of 0.04, 0.96KNN–0.04BMN ceramic obtained good energy storage performance with acceptable energy storage density [Formula: see text][Formula: see text] of 1.826 J/cm3 and energy storage efficiency [Formula: see text] of 77.4%, as well as good frequency stability (1–500 Hz) and fatigue resistance (1–5000 cycles). Meanwhile, a satisfactory charge–discharge performance with power density [Formula: see text][Formula: see text] [Formula: see text] 98.90 MW/cm3, discharge time [Formula: see text][Formula: see text] < 70 ns and temperature stability (30–180∘C) was obtained in 0.96KNN–0.04BMN ceramic. The small grain size ([Formula: see text]150 nm) and the high polarizability of Bi[Formula: see text] are directly related to its good energy storage capacity. This work proposes a feasible approach for lead-free KNN-based ceramics to achieve high-energy storage and ultra-fast charge–discharge performance as well as candidate materials for the application of advanced high-temperature pulse capacitors

    Combined transabdominal and transvaginal ultrasound-guided percutaneous microwave ablation of uterine myomas: an effective monitoring technique

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    AbstractObjective This study compared the feasibility and efficacy of transabdominal ultrasound (TAU) and combined transabdominal and transvaginal ultrasound (TA/TV US)-guided percutaneous microwave ablation (PMWA) for uterine myoma (UM).Method This study enrolled 73 patients with UM who underwent PMWA via the transabdominal ultrasound-guided (TA group) or the combined transabdominal and transvaginal ultrasound-guided (TA/TV group) approaches. The intraoperative supplementary ablation rates, postoperative immediate ablation rates, lesion reduction rates and other indicators three months postoperatively were compared between the groups. The display of the needle tip, endometrium, uterine serosa, rectum and myoma feeding vessels under the guidance of TAU, transvaginal ultrasound (TVU) and TA/TV US were evaluated in the TA/TV group.Results In the TA/TV group, the real-time position of the needle tip and the endometrium complete display rate of the same lesions with TVU guidance were significantly higher than those using TAU. TA/TV US guidance significantly improved the complete display rate of each indicator. The intraoperative supplementary ablation rate in the TA/TV group was lower than that in the TA group. Similarly, the postoperative immediate ablation and volume reduction rates of the lesions three months postoperatively were higher than those in the TA group, especially for lesions with a maximum diameter ≥6 cm.Conclusion TA/TV US is an effective monitoring method that can be used to improve imaging display. Its use is recommended in patients with obesity, poor transabdominal ultrasound image quality and large myoma volumes
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