Utility of Nitriles in Organic Synthesis: Synthesis of Poly-Functionaly Substituted Pyridones and Isoquinoline Derivatives. Alex. J. Pharm. Sci.

Aryl hydrocarbon receptor (AhR) ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and metals, such as mercury (Hg(2+)), are environmental co-contaminants and their molecular interaction may disrupt the coordinated regulation of the carcinogen-activating enzyme cytochrome P450 1A1 (CYP1A1). Therefore, we examined the effect of co-exposure to Hg(2+) and TCDD on the expression of the CYP1A1 in HepG2 cells. Our results showed that Hg(2+) significantly inhibited the TCDD-mediated induction of CYP1A1 at the mRNA, protein, and catalytic activity levels. At the transcriptional level, co-exposure to Hg(2+) and TCDD significantly decreased the TCDD-mediated induction of AhR-dependent luciferase reporter gene expression. Moreover, Hg(2+) did not affect CYP1A1 mRNA stability, while decreasing its protein half-life, suggesting the involvement of a posttranslational mechanism. Importantly, Hg(2+) increased the expression of heme oxygenase-1 (HO-1), a rate limiting enzyme in heme degradation, which coincided with further decrease in the CYP1A1 catalytic activity levels. Upon using a competitive HO-1 inhibitor, tin mesoporphyrin, heme precursor, hemin, or transfecting the HepG2 cells with siRNA for HO-1 there was a partial restoration of the inhibition of TCDD-mediated induction of CYP1A1 catalytic activity. In conclusion, we demonstrate that Hg(2+) down-regulates the expression of CYP1A1 at the transcriptional and posttranslational levels in HepG2 cells. In addition, HO-1 is involved in the modulation of CYP1A1 at the posttranslational level.

The monolingual/bilingual dictionary use dichotomy has recently gained more spotlight than before, and this dichotomy has turned back to reassess the usefulness of each type in terms of vocabulary knowledge and acquisition. Although EFL (English as a foreign language) learners perceive dictionaries as inevitable references for vocabulary knowledge and linguistic consultation and almost all (learners and teachers) consider dictionaries ‘absolutely essential’ in the learning and teaching profession (Christianson, 1997; Walz, 1990; McAlpine and Myles, 2003), the usefulness of dictionaries tends to be dependent upon the type of dictionary being consulted (Laufer and Hadar, 1997; Hulstijn, 1993; Knight, 1994). Within this heated debate and abounding controversies over the usefulness of dictionary, the usability of dictionary and dictionary usefulness (Laufer and Kimmel, 1997) “do not necessarily go hand in hand” (p. 362), and Arab FL (Foreign language)  learners’ perspectives towards dictionary types problems and users’ dictionary type preferences are not yet unearthed (Al-Ajmi, 2002). Moreover, within the recent emphasis for dictionary skills (Scholfield, 1982, Laufer and Hadar, 1997; Laufer and Kimmel, 1997), it is reported that Arab learners are not dictionary competent or skilled dictionary users and do lack the necessary skills (Aly, 2004). Within this framework, this qualitative study aims at arriving at a deeper understanding of the problems of dictionary use, either bilingual or monolingual, as faced by Libyan Arab learners for general dictionary use purposes among postgraduate master students at UUM(Univeristi Utara Malaysia). 

Positioning systems are one of the key elements required by location-based services (LBS). As global positioning system (GPS) was never intended for indoor environments, indoor positioning systems based on wireless local area networks (WLAN) have been proposed as a viable solution. RADAR algorithm is one of the famous indoor positioning techniques. It uses a database of predetermined fingerprints for selected locations to estimate the location of a mobile user in the signal space. Another new proposed algorithm named the Enhanced Fingerprint (EFP) uses the same principle as RADAR algorithm but with more than one fingerprint per location. In this paper we investigated the location fingerprint based algorithms by taking RADAR and EFP with more details. We evaluated these two algorithms in terms of accuracy, reliability and computation time. Experiment results show that the EFP algorithm gains 1.82 m of accuracy over RADAR algorithm, while the last one saves 75% of computation time. We found that EFP algorithm is more consistent with varying number of training samples.

Proteomic and molecular studies on the human follicle and follicular fluid: phenotypic differences between human granulosa cell subtypes.

Abstract

The present report concerns a 23-year-old woman who sustained an injury to her right knee while playing 10-pin bowling on a Nintendo Wii video game console. She presented to our orthopaedic outpatients clinic 3 months later with history and examination findings suggestive of a medial meniscal tear, which was confirmed by MRI scan. She underwent arthroscopic partial medial meniscectomy and made an uneventful recovery.