采用超声组装与滚压工艺制备铝–碳纳米管复合材料

This study introduced a novel fabrication of aluminum–carbon nanotube (CNT) composites by employing bulk acoustic waves and accumulative roll bonding (ARB). In this method, CNT particles were aligned using ultrasonic standing wave in an aqueous media, and the arrayed particles were precipitated on the aluminum plate substrate. Then, the plates rolled on each other through the ARB process with four passes. Optical and scanning electron micrographs demonstrated the effective aligning of CNTs on the aluminum substrate with a negligible deviation of arrayed CNTs through the ARB process. The X-ray diffraction pattern of the developed composites showed no peaks for carbon and aluminum carbide. In addition, tensile tests showed that the longitudinal strength of the specimens processed with aligned CNTs was significantly greater than that of the specimens with common randomly dispersed particles. The proposed technique is beneficial for the fabrication of Al–CNT composites with directional mechanical strength.     

A preliminary survey of the insect fauna of the Hajar Mountain Range,Oman

The Hajar Mountain Range of Northern Oman is an important centre of species endemism, and of biogeographical interest as a crossroads between the Afrotropical and Palaearctic regions. Despite this, the invertebrate fauna of the region is largely unknown, with very little dedicated research or surveys having been undertaken until now. Here we present the invertebrate species collected and identified from five different survey locations within the Hajar Mountains. This preliminary checklist contains 296 records, of which 36 are new records for Oman. Our surveys also discovered two new species of ant: Lepisiota omanensis collected from Jebel Qahwan Reserve and at the base of Jebel Akhdar, and Anochetus annetteae from Hibra Village in the Nakhl Region.     

Addenda to the insect fauna of Al-Baha Province,Kingdom of Saudi Arabia with zoogeographical notes

The first list of insects (Arthropoda: Hexapoda) of Al-Baha Province, Kingdom of Saudi Arabia (KSA) was published in 2013 and contained a total of 582 species. In the present study, 142 species belonging to 51 families and representing seven orders are added to the fauna of Al-Baha Province, bringing the total number of species now recorded from the province to 724. The reported species are assigned to recognized regional zoogeographical regions. Seventeen of the species are recorded for the first time for KSA, namely: Platypleura arabica Myers [Cicadidae, Hemiptera]; Cletomorpha sp.; Gonocerus juniperi Herrich-Schäffer [Coreidae, Hemiptera]; Coranus lateritius (Stål); Rhynocoris bipustulatus (Fieber) [Reduviidae, Hemiptera]; Cantacader iranicus Lis; Dictyla poecilla Drake &; Hill [Tingidae, Hemiptera]; Mantispa scabricollis McLachlan [Mantispidae, Neuroptera]; Cerocoma schreberi Fabricius [Meloidae, Coleoptera]; Platypus parallelus (Fabricius) [Curculionidae, Coleoptera]; Zodion cinereum (Fabricius) [Conopidae, Diptera]; Ulidia ?ru?ceps Becker [Ulidiidae, Diptera]; Atherigona reversura Villeneuve [Muscidae, Diptera]; Aplomya metallica (Wiedemann); Cylindromyia sp. [Tachinidae, Diptera]; Messor semirufus (André); and Nesomyrmex denticulatus (Mayr) [Formicidae, Hymenoptera]. Also, the reduviid bug Dasycnemus sahlbergi Bergroth, that was questionably recorded from KSA is confirmed herein as occurring in KSA. The generic name Peirates (Reduviidae, Hemiptera) and the specific name of Apis florea Fabricius (Apidae, Hymenoptera) were inadvertently misspelled in the original list and are corrected here. Zoogeographically, the present study supports the original study conclusion that the insect species composition of Al-Baha Province is strongly affiliated with the Afrotropical Region rather than to the Palearctic Region or the Eremic Zone. Our insect surveys emphasize the fact that parts of the Arabian Peninsula, including Al-Baha Province, ought to be considered part of the Afrotropical Region rather than in the Palaearctic Region or the Eremic Zone.     

Corticosteroid effects on cholinergic enzymes in ethanol-treated fetal brain cell cultures

In the presence of ethanol, corticosterone and dexamethasone inhibit choline acetyltransferase and acetyl-cholinesterase activities in cultured fetal brain cells of the rat. These results suggest that corticosteroids may have an important influence on the activity of cholinergic enzymes in the fetal brain may antagonize the effects of ethanol in this setting.     

Reduction of incubation time in citric acid fermentation by vermiculite

Zusammenfassung In Gegenwart des exfolierten Tonminerals Vermikulit wird die Zitronensäurebildung durchAspergillus niger besonders stimuliert. Dabei wird die Induktionsphase verkürzt sowie die gesamte Gärgeschwindigkeit im messbaren Bereich der Zitronensäurebildungsphase erhöht. Die Stimulierung scheint einzig auf verbesserten Haushalt der Spurenelemente zurückzuführen zu sein.     

Dexamethasone protection against the acute lethality of ethanol in mice

Summary The administration of dexamethasone (DXM, 2.00 mg/kg) 1 h prior to the injection of lethal doses of ethanol was found to offer complete protection against ethanol toxicity at doses up to 5.25 g/kg and partial protection using higher doses. It is suggested that DXM central action might be involved in the protection against ethanol toxicity.Supported by a grant from U.S. National Aeronautics and Space Administration.     

Controllable and switchable capillary adhesion mechanism for bio-adhesive pads: Effect of micro patterns

Some insects and animals, such as bugs, grasshoppers and tree frogs, realize their efficient adhesion mechanism to glass surface, wall and ceiling by injecting a wetting liquid thin film into the pad-substrate contact area. Their ability to control adhesion (attaching or detaching from a surface) is in many cases connected to the contact geometry and surface patterns of their attachment pads. This paper focuses on the dependence of the capillary adhesion (wet adhesion) on the micro patterns of the bio-adhesive pads. The objective is to reveal the possible mechanism for a bio-adhesive pad to control capillary force through adjusting its micro-scale surface pattern and topography. A capillary adhesion force model is built up taking account of the combined role of micro-dimple geometry as well as the wetting behavior of the confined liquid thin film. Calculated results of the apparent contact angle on the regularly micro-dimpled surfaces are compared with and in good agreement with the experimental measurements. Simulation of the capillary adhesion force reveals that it is controllable in a large magnitude by adjusting a dimensionless surface pattern parameter k defined as a/(a+b), where a is the diameter of micro dimple, and (a+b) is the side length of one pattern cell. When adjusting the parameter k more than 0.75, the capillary adhesion force could be switchable from attractive to repulsive. This effect of micro patterns on the interfacial capillary force is proved to be dominant when the pad-substrate clearance decreases to the nano/micrometer scale. These results indicate that a controllable and switchable capillary adhesive mechanism might be utilized by a living insect or animal to realize its stable adhesion and quick releasing movement through adjusting the micro-pattern topography of its bio-adhesive pad. Supported by the National Natural Science Foundation of China (Grant Nos. 50575123, 50730007), PPP Project from CSC and DAAD, and German Research Foundation (DFG) (Grant No. SFB622) (Y.H. Liu and S.I.-U. Ahmed)     

Diversity and specificity of the mitogen-activated protein kinase phosphatase-1 functions

The balance of protein phosphorylation is achieved through the actions of a family of protein serine/threonine kinases called the mitogen-activated protein kinases (MAPKs). The propagation of MAPK signals is attenuated through the actions of the MAPK phosphatases (MKPs). The MKPs specifically inactivate the MAPKs by direct dephosphorylation. The archetypal MKP family member, MKP-1 has garnered much of the attention amongst its ten other MKP family members. Initially viewed to play a redundant role in the control of MAPK signaling, it is now clear that MKP-1 exerts profound regulatory functions on the immune, metabolic, musculoskeletal and nervous systems. This review focuses on the physiological functions of MKP-1 that have been revealed using mouse genetic approaches. The implications from studies using MKP-1-deficient mice to uncover the role of MKP-1 in disease will be discussed.     

Tunability of physical properties of (Cd:Zn)S thin film by Close Space Sublimation Process (CSSP)

The present paper reports on a systematic study of the influence of Zn alloying on the structural and optical properties of Cd1 xZnxS thin films. X-ray diffraction study for structural analysis reveals that the two binary compounds have been completely transformed into ternary compound with hexagonal (wurtzite) structure with preferred orientation along c-direction with (002) planes. The optical properties such as optical constants and band gap energy of the films were examined by using spectroscopic ellipsometer and Photospectrometery. It was found that the optical constants (n and k) decrease with the addition of Zn content in the alloy. It was also confirmed that the band gap increases with increasing Zn amount in the alloy and is attributed to quantum size effect in the grain size. Raman spectroscopy analysis shows one dominant phonon band at 326 cm 1, the so-called longitudinal optical (LO) mode for all the alloy composition (x). The appearance of a single phonon band in the Raman spectra established the formation of single phase hexagonal structured Cd1 xZnxS thin film. The LO band is asymmetrically broaden and high frequency shifted due to potential fluctuation caused by the dopant material. The AFM results showed that the surface roughness was decreased with increasing Zn content.