Volatiles of Fresh and Commercial Sweet Red Pepper Pastes: Processing Methods and Microwave Assisted Extraction

Microwave-assisted hexane or water extraction was used to extract flavor compounds from fresh red pepper fruit and also from traditionally and industrially made pepper pastes. The composition of the volatile components from each extract was analyzed using comprehensive two-dimensional gas chromatography with time of flight mass spectrometry. In total, 79 compounds were determined including 15 alcohols, 14 terpenes, 13 aldehydes, 12 ketones, 7 fatty acids, 6 fatty acid esters, and 6 browning reaction products. The major common compounds of fresh pepper and the pastes were 2-pentanone, 3-hexanol, acetic acid, oleic acid, and linoleic acid. The compounds (E)-2-undecenal, farnesol, 2-pentadecyn-1-ol, linolenic acid, and squalene were found only in the fresh pepper samples. Browning reaction products were observed in both of the pastes. However, their concentration was much higher in the industrially made one. Microwave-assisted hexane extraction from the traditionally made pepper paste gave the highest number of volatiles. Many volatiles considered to possess pleasant aroma characteristics were observed only in the traditionally made paste.     

Determination of polycyclic aromatic hydrocarbons in edible oils and barbecued food by HPLC/UV–Vis detection

Determination of nine polycyclic aromatic hydrocarbons in corn, sunflower, olive oils and barbecued meat and fish by HPLC/UV–Vis method is described. The extraction procedure included a saponification, liquid–liquid extraction and finally purification of PAHs through a house-made silica–alumina column. Chromatographic determination was based on separation of PAHs on ODS column and measurement at 254 nm. All polycyclic aromatic hydrocarbons were separated and analyzed in 12 min on reversed phase ODS column with acetonitrile/water mobile phase at 1.5 mL min⁻¹ flow rate. The detection limits of nine polycyclic aromatic hydrocarbons ranged from 0.26 to 1.15 μg L⁻¹ at a signal/noise ratio of 3. The linearity of the method was between 0.9951 and 0.9996. Oil samples contain different PAHs ranging from 0.44 to 98.92 μg L⁻¹. Barbecuing process increased the concentration (in the range of 2- to 8-fold) and caused the formation of PAHs in food samples.     

Nonlinear stress analysis in adhesively bonded single-lap joint

In this investigation, an analytical elastic–plastic solution was proposed for a single-lap joint. A ductile adhesive joint material was used as the bond material. FM-73 was utilized in the study. The influence of the bending moment was neglected in the solution. The solution was modified for shear stresses. The analytical solution was compared with the FEM solution. An ANSYS 10.0 solution was employed in the numerical solution. Both solutions were compared with each other. These two solutions produced close agreements.     

粒状土与结构接触面多重剪切边界面模型

针对工程中存在大量的土与结构物相互作用,使接触面的力学特性对土体和结构物的受力变形及其相互作用产生重要影响的问题,利用塑性滑移理论,将粗粒土与结构接触面的宏观变形分解为一个宏观法向变形和剪切面内一系列不同方向分布的相互独立虚拟微观剪切变形;通过虚功原理,在粒状土的状态相关和边界面弹塑性理论框架内建立一个粗粒土与结构接触面的多重剪切边界面模型.每个微观剪切变形包含一个微观剪应力-应变关系和一个微观应力-剪胀关系.引入一个与接触面土体密度和法向应力相关的状态参数,用以描述不同状态下土与结构接触面的变形和强度特性.对不同粗粒土与结构接触面在二维或三维应力条件下的单调和循环剪切试验进行模拟计算,模型预测与试验结果吻合良好,说明模型能够合理地描述粗粒土与结构接触面的非线性力学行为.     

Anisotropic Broadband Photoresponse of Layered Type‐II Weyl Semimetal MoTe2

Photodetectors based on Weyl semimetal promise extreme performance in terms of highly sensitive, broadband and self‐powered operation owing to its extraordinary material properties. Layered Type‐II Weyl semimetal that break Lorentz invariance can be further integrated with other two‐dimensional materials to form van der Waals heterostructures and realize multiple functionalities inheriting the advantages of other two‐dimensional materials. Herein, we report the realization of a broadband self‐powered photodetector based on Type‐II Weyl semimetal T_d‐MoTe₂. The prototype metal–MoTe₂–metal photodetector exhibits a responsivity of 0.40 mA W^?1 and specific directivity of 1.07 × 10⁸ Jones with 43 μs response time at 532 nm. Broadband responses from 532 nm to 10.6 μm are experimentally tested with a potential detection range extendable to far‐infrared and terahertz. Furthermore, we identify the response of the detector is polarization angle sensitive due to the anisotropic response of MoTe₂. The anisotropy is found to be wavelength dependent, and the degree of anisotropy increases as the excitation wavelength gets closer to the Weyl nodes. In addition, with power and temperature dependent photoresponse measurements, the photocurrent generation mechanisms are investigated. Our results suggest this emerging class of materials can be harnessed for broadband angle sensitive, self‐powered photodetection with decent responsivities.     

综放工作面矿压显现数值模拟研究

近年来,综合放顶煤开采技术成为我国厚煤层开采中应用最为广泛的技术,针对综放工作面所具有的"加长"、"快速推进"的特点,采用FLAC^3D数值模拟计算研究了其矿压显现规律,模拟分析了综放工作面不同推进速度及不同长度条件下围岩的应力场、位移场及塑性区的分布与演化规律,得出了综放工作面的矿压显现规律,为工作面支架的选型提供了依据。     

Sequences within a small yeast RNA required for inhibition of internal initiation of translation: interaction with La and other cellular proteins influences its inhibitory activity

We recently reported purification, determination of the nucleotide sequence, and cloning of a 60-nucleotide RNA (I-RNA) from the yeast Saccharomyces cerevisiae which preferentially blocked cap-independent, internal ribosome entry site (IRES)-mediated translation programmed by the poliovirus (PV) 5' untranslated region (UTR). The I-RNA appeared to inhibit IRES-mediated translation by virtue of its ability to bind a 52-kDa polypeptide which interacts with the 5' UTR of viral RNA. We demonstrate here that the HeLa 52-kDa I-RNA-binding protein is immunologically identical to human La autoantigen. Moreover, I-RNA-mediated purified La protein. By using I-RNAs with defined deletions, we have identified sequences of I-RNA required for inhibition of internal initiation of translation. Two smaller fragments of I-RNA (16 and 25 nucleotides) inhibited PV UTR-mediated translation from both monocistronic and bicistronic RNAs. When transfected into HeLa cells, these derivatives of I-RNA inhibited translation of PV RNA. A comparison of protein binding by active and inactive I-RNA mutants demonstrates that in addition to the La protein, three other polypeptides with apparent molecular masses of 80, 70, and 37 kDa may influence the translation-inhibitory activity of I-RNA.     

Osteoblastoma of the humerus associated with type-I Gaucher's disease. A case report

We report a unique case of juxtacortical osteoblastoma of the humeral shaft, which stimulated the appearance of an extraosseous extension of Gaucher-cell deposits. The tumour was treated successfully by curettage and bone grafting. We can find no previous report of this association between osteoblastoma and Gaucher's disease.