Analysis of the hydrogen and oxygen stable isotope ratios of beverage waters without prior water extraction using isotope ratio infrared spectroscopy

Hydrogen (δ²H) and oxygen (δ¹⁸O) stable isotope analysis is useful when tracing the origin of water in beverages, but traditional analytical techniques are limited to pure or extracted waters. We measured the isotopic composition of extracted beverage water using both isotope ratio infrared spectroscopy (IRIS; specifically, wavelength‐scanned cavity ring‐down spectroscopy) and isotope ratio mass spectrometry (IRMS). We also analyzed beer, sodas, juices, and milk ‘as is’ using IRIS. For IRIS analysis, four sequential injections of each sample were measured and data were corrected for sample‐to‐sample memory using injections (a) 1‐4, (b) 2‐4, and (c) 3‐4. The variation between δ²H and δ¹⁸O values calculated using the three correction methods was larger for unextracted (i.e., complex) beverages than for waters. The memory correction was smallest when using injections 3‐4. Beverage water δ²H and δ¹⁸O values generally fit the Global Meteoric Water Line, with the exception of water from fruit juices. The beverage water stable isotope ratios measured using IRIS agreed well with the IRMS data and fit 1:1 lines, with the exception of sodas and juices (δ²H values) and beers (δ¹⁸O values). The δ²H and δ¹⁸O values of waters extracted from beer, soda, juice, and milk were correlated with complex beverage δ²H and δ¹⁸O values (r = 0.998 and 0.997, respectively) and generally fit 1:1 lines. We conclude that it is possible to analyze complex beverages, without water extraction, using IRIS although caution is needed when analyzing beverages containing sugars, which can clog the syringe and increase memory, or alcohol, a known spectral interference. Copyright © 2010 John Wiley & Sons, Ltd.     

Hyperfine interactions of aluminum-substituted goethites in external magnetic fields

Six goethite samples α(Fe, Al)OOH prepared by a similar synthetic method but varying in Al substitution from 0 to 31 mole percent, have been examined by Mössbauer spectroscopy at ≌ 4 K in an external field of 6 T. The resulting spectra have been fitted by two methods: first a simplified model consisting of three distributions of magnetic fields (parallel, perpendicular and antiparallel orientations of internal and external field) and second, a model-independent bi-dimensional distribution of both the internal hyperfine field and the orientation angle ? with the external field. Both fitting methods show that the angular distribution of spins is not random in the case of high Al substitution, but canted towards an antiparallel orientation (?>90°).     

Densest Packing of Equal Spheres in Hyperbolic Space

   Abstract. We propose a method to analyze the density of packings of spheres of fixed radius in the hyperbolic space of any dimension m≥ 2 , and prove that for all but countably many radii, optimally dense packings must have low symmetry.     

粘结超磁致伸缩Tb-Dy-Fe合金磁致伸缩性能的研究

采用粘结方法制备了Tb1-xDyxFe2棒状合金样品，经筛选确定了粘结材料的制备工艺，测试了粘结棒状合金样品的静态、动态磁致伸缩系数和磁机械耦合系数k33。结果表明，所制备的粘结棒状样品具有较高的磁致伸缩性能，且动态磁致伸缩参数k33和磁机械耦合系数k33高于国外所报道的结果。     

Mössbauer study of small-particle maghemite

Two small-particle maghemite (λ-Fe₂O₃) samples have been investigated with the Mössbauer effect. From the results of the model-independent hyperfine-field distribution fits some characteristic temperature-dependent parameters have been obtained. The spectra at the lowest temperatures could be fitted with two strongly overlapping hyperfine-field distributions with different isomer shifts. Spectra in applied magnetic fields ranging from 40 to 60 kOe, and at 4.2 K showed non vanishing Δm ₁=0 absorption lines. The hyperfine-field distribution and canting-angle distribution method for fitting these spectra did not yield reasonable results. Therefore, a bi-dimensional hyperfine-field-canting-angle distribution has been applied, and was found to reproduce the experimental line shapes with remarkable adequacy. The resulting distribution profiles revealed a linear correlation between H_hf and the angle between the magnetic moments and the external field.     

Facile Hydrolysis and Alcoholysis of Palladium Acetate

Palladium(II) acetate is readily converted into [Pd₃(μ²‐OH)(OAc)₅] ( 1 ) in the presence of water in a range of organic solvents and is also slowly converted in the solid state. Complex 1 can also be formed in nominally anhydrous solvents. Similarly, the analogous alkoxide complexes [Pd₃(μ²‐OR)(OAc)₅] ( 3 ) are easily formed in solutions of palladium(II) acetate containing a range of alcohols. An examination of a representative Wacker‐type oxidation shows that the Pd‐OH complex 1 and a related Pd‐oxo complex 4 can be excluded as potential catalytic intermediates in the absence of exogenous water.     

Development of a method using high‐performance liquid chromatographic fingerprint and multi‐ingredients quantitative analysis for the quality control of Yangxinshi Pian

A simple and reliable method of high‐performance liquid chromatography with diode array detection method was developed for fingerprint analysis and simultaneous determination of six compounds including puerarin, salvianolic acid B, berberine hydrochloride, palmatine chloride, dehydrocorydaline, and icariin in the Chinese medicine preparation Yangxinshi Pian. The separation was performed on an Agilent Eclipse XDB‐C₁₈ reserved‐phase column (250 mm × 4.6mm I.D., 5 μm) using gradient elution with 50 mmol/L monopotassium phosphate aqueous solution and methanol as mobile phase at a flow rate of 1.0 mL/min. The column operating temperature was set at 30°C, and the detection wavelength was 280 nm. The method was validated by linearity, precision, accuracy, stability, and recovery. For fingerprint analysis, 25 peaks were selected as the common peaks, and four kinds of similarities including cosine similarity (S), ratio of similarity (S′), projection content similarity (C), and content similarity (P) were applied to evaluate the quality consistency of different batches of Yangxinshi Pian. The results showed that the developed method was an efficient tool for quality evaluation of Yangxinshi Pian.     

The Cancer Genetics Network: recruitment results and pilot studies

OBJECTIVE: The National Cancer Institute established the Cancer Genetics Network (CGN) to support collaborative investigations into the genetic basis of cancer susceptibility, explore mechanisms to integrate this new knowledge into medical practice, and identify ways of addressing the associated psychosocial, ethical, legal, and public health issues. SUBJECTS AND METHODS: The CGN has developed the complex infrastructure required to support the projects, including the establishment of guidelines and policies, uniform methods, standard questionnaires to be used by all of the centers, and a standard format for submission of data to the Informatics Center. Cancer patients and their family members have been invited to enroll and be included in a pool of potential study participants. The Information Technology Group is responsible for support of the design, implementation, and maintenance of the multicenter Network-wide research protocols. RESULTS: As of January 2004, the CGN contained data on 23,995 probands (participants) and 425,798 family members. As a resource for cancer genetic studies, the CGN has a large number of probands and first-degree relatives with and without cancer and with multiple ethnicities. Different study designs can be used including case-control, case-case, and family studies. CONCLUSIONS: The unique resources of the CGN are available for studies on cancer genetic susceptibility, translational research, and behavioral research. The CGN is now at a point where approved collaborators may have access to enrolled patients and their families for special studies, as well as to the clinical, environmental and family cancer history data banked in the Informatics Center.     

黄酮-6-羧酸类化合物的合成、表征和抑菌活性

通过查尔酮路线合成了6种黄酮-6-羧酸化合物,采用I2/DMSO为氧化剂通过微波辐射合成了其中3种黄酮羧酸.所有化合物的结构通过NMR,IR和元素分析方法进行了表征,并采用X射线单晶衍射法进一步测定了黄酮-6,4'-二羧酸的晶体结构.初步生物活性试验结果表明,6种化合物对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌均有一定的抑制作用.     

Superhalogen properties of CumCln clusters: theory and experiment

Using a combination of density functional theory and anion photoelectron spectroscopy experiment, we have studied the structure and electronic properties of CuCl(n)(-) (n = 1-5) and Cu(2)Cl(n)(-) (n = 2-5) clusters. Prominent peaks in the mass spectrum of these clusters occurring at n = 2, 3, and 4 in CuCl(n)(-) and at n = 3, 4, and 5 in Cu(2)Cl(n)(-) are shown to be associated with the large electron affinities of their neutral clusters that far exceed the value of Cl. While CuCl(n) (n ≥ 2) clusters are conventional superhalogens with a metal atom at the core surrounded by halogen atoms, Cu(2)Cl(n) (n ≥ 3) clusters are also superhalogens but with (CuCl)(2) forming the core. The good agreement between our calculated and measured electron affinities and vertical detachment energies confirm not only the calculated geometries of these superhalogens but also our interpretation of their electronic structure and relative stability.