Wideband rectangular slot antenna for personal wireless communication systems

Antenna designs are achieved for wideband operation by the use of a coplanar patch-slot antenna, fed by a coplanar waveguide. This design is easily tuned to operate at 2.45 and 5.75 GHz, with wide bandwidth for wireless systems. The operating frequency is controlled by modifying the patch dimensions. The return loss, input impedance, radiation pattern, directivity, gain, and efficiency of the proposed designs are computed and presented. A parametric study of the antenna is also introduced.     

Voltage-Current Characteristics of a Simple Zinc Oxide Varistor Containing Magnesia

This paper examines the effect of MgO addition on the structural and electrical characteristics of a ZnO varistor composition with few dopants. MgO acts as a grain-growth inhibitor. The electrical performances of the obtained varistors are improved.     

Education for manufacturing industry: The rudimentary requirements from a student's viewpoint

There is much evidence that U.S. manufacturing is not responding to the global challenge to its manufacturing base. In addition, there are relatively few university graduates considering choosing operations management as a career. Of those who do make such a choice, many are not well-prepared. One possible reason for some of these problems lies in the fact that most programs of study are designed from the academic, rather than the students', point of view. Some common-sense suggestions to help alleviate these problems will be discussed.     

Predicting relapse back to smoking: Contrasting affective and physical models of dependence.

Traditional models of physical dependence suggest that nicotine dependence should be reflected by the extent of drug exposure (e.g., smoking rate) and by evidence of physiological adaptation (e.g., withdrawal severity). An affective model suggests that nicotine dependence should be related to an individual's tendency to experience negative affect and expectations that nicotine use would ameliorate such affect. This research investigated the ability of these 2 models to predict relapse back to smoking at 6 months postquit, Logistic regression models were developed and tested in 505 heavy smokes participating in nicotine patch clinical trials. Results supported both models, but the most potent predictor of outcome was postquit negative affect, which accounted for much of the predictive validity of traditional measures of nicotine dependence. Affective reactivity appears to be a core constituent of dependence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Management of ingested foreign bodies within the appendix: a case report with review of the literature

A case is reported of an elective appendectomy in a patient with known ingestion of a sharp foreign body. The metal drill bit was ingested unintentionally 3 months before presentation at our institution. Plain abdominal films demonstrated the foreign body in the right lower abdominal quadrant. Because the gold dental drill bit was sharp and thought to be lodged in the terminal ileum or cecum, an attempt was made to remove the object during colonoscopy. This attempt was unsuccessful because no drill bit could be detected in the colon or terminal ileum. A laparoscopic exploration was performed, and the foreign body was found to lie in the appendix, after bowel manipulation under fluoroscopic guidance and with direct laparoscopic visualization. A laparoscopic assisted appendectomy was performed. On pathologic examination the drill bit was embedded in the tip of the appendix with signs of intramucosal acute inflammation. Management and indication for surgery of foreign bodies in the appendix are discussed, and we review the related literature. This is the second reported case of a dental drill bit in the appendix causing appendicitis.     

Effect of nordihydroguaiaretic acid on luteal phase length and oxytocin-induced release of prostaglandin F2 alpha in heifers

Two experiments were conducted to determine if intrauterine infusion of nordihydroguaiaretic acid, a lipoxygenase pathway inhibitor, would delay luteolysis (Experiment 1) and inhibit oxytocin-induced release of prostaglandin F2 alpha (as measured by the stable prostaglandin F2 alpha metabolite, 15-keto-13,14-dihydroprostaglandin F2 alpha) in plasma on d 16 (d 0 = estrus) of the estrous cycle (Experiment 2). Nordihydroguaiaretic acid (20 mg) or saline was infused twice daily into the uterus on d 14 to 23 (Experiment 1) or d 14 to 20 (Experiment 2) postestrus, respectively. In Experiment 1 and 2, mean concentration of progesterone was higher and luteolysis was delayed in nordihydroguaiaretic acid-infused heifers compared with saline-infused heifers. In Experiment 2, saline or oxytocin (100 IU, i.v.) was injected into each heifer on d 16 postestrus to stimulate the release of prostaglandin F2 alpha from the uterus. Mean concentration of 15-keto-13,14-dihydroprostaglandin F2 alpha increased within 1.5 h postinjection in heifers infused with saline, whereas concentration of 15-keto-13,14-dihydroprostaglandin F2 alpha in nordihydroguaiaretic acid-infused heifers did not increase within the same time period. Thus, nordihydroguaiaretic acid may inhibit both the lipoxygenase and cyclooxygenase pathways of arachidonic acid metabolism and therefore delay luteolysis.     

A paradigm of experimentally induced mild hyperthyroidism: effects on nitrogen balance, body composition, and energy expenditure in healthy young men

OBJECTIVE: To conceptualize, with fine needle aspiration cytology (FNAC), the early cellular events occurring in and around fresh autogenous and allogenic bone grafts during the first 40 postimplantation days. STUDY DESIGN: Forty-eight cases of bone grafts were studied by FNAC at serial intervals of 10, 20, 30 and 40 postimplantation days. Twenty patients were recipients of autogenous grafts, 16 received 0.6N HCI partially decalcified allogenic bone implants, and 4 received combined autogenous and allogenic bone grafts (included in the allograft group). There were eight control cases of closed fracture shaft femur, which were managed conservatively. RESULTS: The initial cellular responses in autogenous grafts, allografts and controls appear to be a part of the nonspecific reparative process followed by a more specific phase, with a steady increase in relative lymphocyte count from the 20th day onwards. Osteogenesis, as judged by osteoblasts and osteoclasts, was also comparable. CONCLUSION: Partially decalcified allografts appear to be a good substitute for autogenous bone grafts in clinical practice when adequate autogenous material is not available. FNAC is a good technique for studying bone graft responses without interfering with graft uptake. It is helpful in the early detection of subclinical infection or any other pathology at the graft site.     

Demonstration of a word design strategy for DNA computing on surfaces

A strategy for DNA computing on surfaces using linked sets of 'DNA words' that are short oligonucleotides (16mers) is proposed. The 16mer words have the format 5'-FFFFvvvvvvvvFFFF-3' in which 4-8 bits of data are stored in 8 variable ('v') base locations, and the remaining fixed ('F') base locations are used as a word label. Using a template and map strategy, a set of 108 8mers each of which possesses at least a 4 base mismatch with the complements to all the other members of the set (4bm complements) are identified for use as a variable base sequence set. In addition, sets of 4 and 12 word labels of the form ABCD....DCBA that are respectively 8bm and 6bm complements with each other are identified. The 16mers are chosen to have a G/C content of 50% in order to make the thermodynamic stability of the perfectly matched hybridized DNA duplexes similar; a simple pairwise additive method is used to estimate the perfect match and mismatch hybridization thermodynamics. A series of preliminary experiments are presented that use small arrays of 16mers attached to chemically modified gold surfaces and fluorescently labeled complements to study the hybridization adsorption and enzymatic manipulation of the oligonucleotides.