Three new species of the genus Zaitzevia Champion, 1923 (Coleoptera, Elmidae) from China

Three new riffle beetles of the genus Zaitzevia Champion, 1923 are described from China, namely Zaitzevia sichuanensis sp. nov. and Zaitzevia fengtongzhaiensis sp. nov. from Sichuan Province, and Zaitzevia yingzuijieensis sp. nov. from Hunan Province. Habitus and diagnostic features of the new species are illustrated. A checklist of all known Chinese Zaitzevia species is given, and a key and distributional map of Zaitzevia species from the Chinese mainland are provided

Synthesis and properties of novel soluble fluorinated polyamides containing pyridine and sulfone moieties

AbstractA new diamine containing pyridine and trifluoromethylphenyl groups, 4-(4-trifluoromethylphenyl)-2,6-bis(4-aminophenyl)pyridine, was synthesized and used in the preparation of the fluorinated polyamides containing pyridine and sulfone moieties with inherent viscosities of 0.70–1.06dLg−1 by the low temperature polycondensation with 4,4′-sulfonyl dibenzoyl chloride, 4,4′-[sulfonyl bis(4-phenyleneoxy)]dibenzoyl chloride, 3,3′-[sulfonyl bis(4-phenyleneoxy)]dibenzoyl chloride and 4,4′-[sulfonyl bis(2,6-dimethyl-1,4-phenyleneoxy)]dibenzoyl chloride in N,N-dimethylacetamide (DMAc) solution containing pyridine, respectively. All the polymers are amorphous and readily soluble in organic solvents such as DMAc, N-methyl-2-pyrrolidinone (NMP), N,N-dimethylformamide, dimethyl sulfoxide, pyridine (Py), and tetrahydrofuran at room temperature. The resulting polymers showed glass transition temperatures between 280 and 318°C and 10% weight loss temperatures ranging from 485°C to 516°C, and char yields at 800°C higher than 50% in nitrogen. All polymers could be casted into transparent, flexible and strong films from DMAc solutions with tensile strengths of 72–81MPa, elongations at break of 12–15%, and tensile moduli of 1.8–2.1GPa. These polymers had low dielectric constants of 3.40–3.51 (1MHz), low moisture absorption in the range of 1.08–1.28%, and high transparency with an ultraviolet–visible absorption cut-off wavelength in the 374–382nm range

Wave Characteristics of Falling Film on Inclination Plate at Moderate Reynolds Number

Falling water film on an inclined plane is studied by shadowgraphy. The ranges of inclination angle and the film Reynolds number are, respectively, up to 21° and 60. Water is used as working fluid. The scenario of wave regime evolution is identified as three distinctive regimes, namely, initial quiescent smooth film flow, two-dimensional regular solitary wave pattern riding on film flow, and three-dimensional irregular wave pattern. Three characteristic parameters of two-dimensional solitary wave pattern, namely, inception length, primary pulse spacing, and propagation velocity, are examined, which are significant in engineering applications for estimation of heat and mass transfer on film flow. The present experimental data are well in agreement with the Koizumi correlations, the deviation from which is limited to 20% and 15%, respectively, for primary pulse spacing and propagation velocity. Through the scrutiny of the present experimental observation, it is concluded that wave evolution on film flow at the moderate Reynolds number is controlled by gravity and drag and the Rayleigh-Taylor instability that occurred on the steep front of primary pulse triggers the disintegration of continuous two-dimensional regular solitary wave pattern into three-dimensional irregular wave pattern

Temperature Dependent Droplet Impact Dynamics on Flat and Textured Surfaces

Droplet impact dynamics determines the performance of surfaces used in many applications such as anti-icing, condensation, boiling, and heat transfer. We study impact dynamics of water droplets on surfaces with chemistry/texture ranging from hydrophilic to superhydrophobic and across a temperature range spanning below freezing to near boiling conditions. Droplet retraction shows very strong temperature dependence especially on hydrophilic surfaces; it is seen that lower substrate temperatures lead to lesser retraction. Physics-based analyses show that the increased viscosity associated with lower temperatures combined with an increased work of adhesion can explain the decreased retraction. The present findings serve as a starting point to guide further studies of dynamic fluid-surface interaction at various temperatures. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3692598

A Thermostable β-Glucuronidase Obtained by Directed Evolution as a Reporter Gene in Transgenic Plants

A β-glucuronidase variant, GUS-TR3337, that was obtained by directed evolution exhibited higher thermostability than the wild-type enzyme, GUS-WT. In this study, the utility of GUS-TR337 as an improved reporter was evaluated. The corresponding gus-tr3337 and gus-wt genes were independently cloned in a plant expression vector and introduced into Arabidopsis thaliana. With 4-MUG as a substrate, plants containing the gus-wt gene showed no detectable β-glucuronidase activity after exposure to 60°C for 10 min, while those hosting the gus-tr3337 gene retained 70% or 50% activity after exposure to 80°C for 10 min or 30 min, respectively. Similarly, in vivo β-glucuronidase activity could be demonstrated by using X-GLUC as a substrate in transgenic Arabidopsis plants hosting the gus-tr3337 gene that were exposed to 80°C for up to 30 min. Thus, the thermostability of GUS-TR3337 can be exploited to distinguish between endogenous and transgenic β-glucuronidase activity, which is a welcome improvement in its use as a reporter

CT Findings of an Ectopic Pancreas in the Anterior Mediastinum

We report here on a rare case of an ectopic pancreatic tissue in the anterior mediastinum. A 32-year-old woman without any symptoms was transferred to our hospital because of an abnormal large mediastinal shadow on her chest radiograph during a checkup. The computed tomography (CT) scan revealed a giant cystic-solid mass that measured 16 × 13 × 8 cm and it was located in the center of the anterior mediastinum and it symmetrically grew to two sides. On enhanced CT scans, the solid component of the mass showed marked enhancement. We performed total surgical resection of the mass and complete pancreatic tissues were verified on the pathological examination