4种动物药水提液中3种嘌呤碱HPLC法测定

以甲醇/水为流动相,反相高效液相色谱-紫外检测器测定了乌蛇、蟾蜍、土虫、地龙水提取液中黄嘌呤、次黄嘌呤、腺嘌呤的含量,对样品提取和高效液相色谱条件进行了优化。 黄嘌呤、次黄嘌呤、腺嘌呤的检出限分别为0.012×10-6、0.041×10-6、0.042×10-6 g/mL,样品分析的日内测定相对标准偏差分别小于4.1%、7.3%、4.5%,日间测定相对标准偏差分别小于5.8%、2.9%、3.1%,平均加标回收率为94%～107%。     

Effect of microcrystallite preparation conditions on the formation of colloid crystals of cellulose

Stable colloidal suspensions of cellulose microcrystallites may be prepared from filter paper by sulfuric acid hydrolysis. Above a critical concentration, the suspensions form a chiral nematic ordered phase, or colloid crystal. The preparation conditions govern the properties of the individual cellulose microcrystallites, and hence the liquid crystalline phase separation of the cellulose suspensions. The particle properties and the phase separation of the suspensions were strongly dependent on the hydrolysis temperature and time, and on the intensity of the ultrasonic irradiation used to disperse the particles. The particle size of the microcrystallites was characterized with transmission electron microscopy and photon correlation spectroscopy. The surface charge was determined by conductometric titration. It was possible to fractionate the microcrystallites by size using the partitioning between isotropic and liquid crystalline phases; the longer microcrystallites migrate to the liquid crystalline phase     

Preparation of Graphene by Using an Intense Cavitation Field in a Pressurized Ultrasonic Reactor

A new and efficient method to produce a large quantity of high‐quality and non‐oxidized graphene flakes from powdered natural graphite by using a high‐intensity cavitation field in a pressurized ultrasonic reactor is demonstrated. TEM and selected‐area electron diffraction (SAED) confirmed the ordered graphite crystal structure of graphene. Atomic force microscopy (AFM) was used to examine the thickness of the graphene sheets. The delamination (exfoliation) of natural graphite in the liquid phase depends on the physical effects of ultrasound, which break down the 3D graphite structure into a 2D graphene structure. The prepared graphene is of high purity and without defects because no strongly oxidizing chemicals are used and no toxic products result. TEM shows that graphene nanosheets were produced with sizes in the range of tens to hundreds of square nanometers; these nanosheets were smooth and without any ripples and corrugations. High‐resolution TEM (HRTEM) and SAED analysis confirmed that the products were graphene nanosheets.     

2-取代亚肼基-1,3-二硫杂环戊烷类化合物的合成及其生物活性研究

以取代苯甲醛、取代吡啶和取代苯甲酸酯等为原料合成了 10种含硫杂环化合物 (其中 2a～ 2g化合物为国内外未见报道 ) .在合成过程中采用了超声波技术 ,极大地缩短了反应时间 ,提高了收率 .所得化合物的结构经IR ,1 HNMR ,MS和元素分析证实 .对其生物活性进行了初步测试 ,结果证明一些化合物具有良好的抑菌或杀菌作用 ,其中 2b ,2c ,2e ,2h ,2i和2j对大肠杆菌 ( 10 40 7号 )的抗菌效果与CET和SMZ相当 ;2b ,2c ,2f对草绿色链球菌 ( 112 3号 )的抗菌效果与CET和SMZ相当 .     

超声波辐射下金属锰引发芳香醛的偶联反应

超声波引发下Mn-H2O-HOAc体系中进行的一系列芳香醛的偶联反应,室温反应3 h得到45%～71%的邻二醇产品.     

超声波辐射下光致变色螺噁嗪类化合物的快速合成

在超声波辐射条件下,以Fischer碱、1-亚硝基-2,7-二羟基萘为原料,无水乙醇为溶剂快速合成了三个螺嗪类光致变色化合物,通过1 H NMR、IR对目标产物的结构进行了表征,讨论了超声辐射时间对合成产率的影响,利用超声波法合成螺噁嗪类光致变色化合物反应速率快、产率有所提高.     

Response surface methodology toward the optimization of high-energy carotenoid extraction from Aristeus antennatus shrimp

High-energy assisted extraction techniques, like ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE), are widely applied over the last years for the recovery of bioactive compounds such as carotenoids, antioxidants and phenols from foods, animals and herbal natural sources. Especially for the case of xanthophylls, the main carotenoid group of crustaceans, they can be extracted in a rapid and quantitative way with the use of UAE and MAE.     

Sonochemical Synthesis of Gold Nanoparticles by Using High Intensity Focused Ultrasound

The sonochemical synthesis of gold nanoparticles (GNPs) with different shapes and size distributions by using high‐intensity focused ultrasound (HIFU) operating at 463 kHz is reported. GNP formation proceeds through the reduction of Au³⁺ to Au⁰ by radicals generated by acoustic cavitation. TEM images reveal that GNPs show irregular shapes at 30 W, are primarily icosahedral at 50 W and form a significant amount of nanorods at 70 W. The size of GNPs decreases with increasing acoustic power with a narrower size distribution. Sonochemiluminescence images help in the understanding of the effect of HIFU in controlling the size and shapes of GNPs. The number of radicals that form and the mechanical forces that are generated control the shape and size of the GNPs. UV/Vis spectra and TEM images are used to propose a possible mechanism for the observed effects. The results presented demonstrate, for the first time, that the HIFU system can be used to synthesise size‐ and shape‐controlled metal nanoparticles.     

超微血管成像和超声造影对乳腺癌病灶内微血流及超微血管的评价及其联合诊断价值

本文探讨了超微血管成像(SMI)和超声造影(CEUS)对乳腺癌病灶内微血流及超微血管的评价,及其联合检查对乳腺癌的诊断价值。选取2017年6月~2019年3月我院收治的经手术病理证实的乳腺癌患者106例(106个肿块)作为研究对象,所有患者术前均完成彩色多普勒血流显像(CDFI)、CEUS及SMI检查。比较SMI、CEUS对乳腺癌的诊断准确率及对病灶内血流信号、穿支血管的显示情况。结果显示,106例乳腺癌(106个肿块)中,SMI和CEUS对乳腺癌的诊断准确率分别为79.25%、83.96%,两者比较差异无统计学意义(P>0.05);SMI联合CEUS检查对乳腺癌的诊断准确率为96.23%,明显高于单一SMI或CEUS的诊断准确率(P<0.05)。在血流信号显示上,SMI检出不丰富血流信号、丰富血流信号分别为64个、42个;CEUS表现为低增强64个、等增强及高增强为42个;SMI和CEUS评价乳腺癌病灶内微血管及血流供应情况具有较好的一致性(P<0.05)。在穿支血管显示上,SMI检出44个、CDFI检出34个,SMI能够清晰检出CDFI不能检出的穿支血管10个。表明SMI和CEUS诊断乳腺癌病灶内微血管及血流供应情况具有较好的一致性,对乳腺癌均有较高的诊断价值,二者联合检查有助于提高乳腺癌的诊断准确率。     

Ligandless,deep eutectic solvent‐based ultrasound‐assisted dispersive liquid‐liquid microextraction with solidification of the aqueous phase for preconcentration of lead,cadmium, cobalt and nickel in water samples

A green and efficient sample preparation method using a deep eutectic solvent‐based ultrasounds‐assisted dispersive liquid–liquid microextraction with solidification of the aqueous phase followed by high performance liquid chromatography analysis was developed for preconcentration and determination of heavy metals in environmental samples. In the proposed method, a novel, low density deep eutectic solvent was prepared by mixing trihexyl(tetradecyl)phosphonium chloride and thiosalicylic acid at a molar ratio of 1:2 and used both as an extractant and complexing agent. Ultrasound was used to disperse the extractant in the aqueous phase of the sample. Then, the phases were separated by centrifugation, after which the aqueous phase was frozen and the surface extractant phase was dissolved in a small volume of acetonitrile and subjected to liquid chromatographic analysis. The proposed method provided precisions (relative standard deviation, n = 5) in the range of 2.6–4.7%. The limit of detection were 0.05, 0.13, 0.06, and 0.11 µg/L for Pb(II), Cd(II), Co(II), Ni(II), respectively. The enhancement factors were equal to 154, 159, 162, and 158 for lead(II), cadmium(II), cobalt(II), and nickel(II), respectively. The accuracy of the proposed method was evaluated using certified reference materials (CA011b – hard drinking water, NIST 1643e – trace elements in water, TMRAIN‐04 – simulated rain sample).