Adsorption-Based Model for Single-Wall Carbon Nanotube Response to NO Gas

In this work, the response of single-wall carbon nanotube as a resistive NO 2 sensor was investigated. A model was developed based on the Freundlich adsorption isotherm and a multi-exponential function was used to describe the relationship between the sensor response and the gas concentration. The model predicts both static and dynamic responses in a closed sampling system. In addition, the model considers the effect of different variables such as the operating temperature, NO 2 concentration in air and the two phases (adsorption and desorption) of response. The developed model is in good accordance with the experimental data. This model could be used to design new environmental detection devices and interpret experimental data by providing some insight into the sensor behaviour during the transient phase

A randomized trial of high dose bolus metoclopramide versus low-dose continuous infusion metoclopramide in the prevention of cisplatin-induced emesis.

We compared the antiemetic efficacy of metoclopramide in a bolus low-dose infusion schedule to that of metoclopramide given in a conventional high-dose bolus schedule in a randomized crossover trial. Thirty-two treatment courses in 16 patients receiving cisplatin chemotherapy were evaluable. The metoclopramide regimen was either 2 mg/kg i.v. bolus, then 20 mg/h by infusion for 4 h, or 2 mg/kg i.v. bolus every 2 h for three doses. Dexamethasone 20 mg i.v. and diphenhydramine 50 mg i.v. were also given. Antiemetic efficacy was assessed by a questionnaire. There were no differences in antiemetic efficacy between the metoclopramide regimens. With either program, 75% of patients were emesis-free, 13% had mild symptoms, and 13% had moderate symptoms (greater than two emetic episodes). The infusion metoclopramide regimen was 30% less expensive than the bolus schedule in our pharmacy. Thus, we recommend low-dose metoclopramide infusion as a less expensive, equally effective alternative to high-dose bolus regimens for antiemetic treatment

Effect of signal acquisition method on the fetal heart rate analysis with phase rectified signal averaging

Phase rectified signal averaging (PRSA) is increasingly used for fetal heart rate monitoring, both with traces acquired with external Doppler cardiotocography (D-FHR), and with transabdominal fetal electrocardiography (ta-FHR). However, it is unclear to what extend the acquisition method influences the PRSA analysis, whether results from using one acquisition method are comparable to those based on FHR acquired by the other method, and if not, which should be the preferred method. To address these questions, we applied PRSA analysis to 28 antepartum synchronous recordings of the fetal heart rate using simultaneously D-FHR and ta-FHR. The data included late-onset intrauterine growth restricted (IUGR) fetuses (n=20) and non-IUGR fetuses (n=8), all of them at gestation ≥34weeks. PRSA analysis depends on two parameters intrinsic to the algorithm, T and S. We analyzed the data using parameters that included all values adopted by other researchers previously (derived from a literature search in PubMed and Google Scholar). T and S were adjusted for the difference in acquisition techniques. We found that the correlation between PRSA analysis based on D-FHR and taFHR decreased with decreasing values of the PRSA parameters T and S. Therefore, the acquisition technique affects PRSA values for high resolution PRSA (low values of T and S). In conclusion, for low resolution PRSA, the results from both acquisition methods are comparable. Because ta-FHR signals provide beat to beat data and thus capture more subtle differences in the heart rate variation than D-FHR signals (pre-processed by commercial monitors), we assumed that ta-FHR may provide potentially valuable extra information compared to D-FHR. However, no parameter settings or acquisition method seemed to have diagnostic value for identifying the late-onset IUGR babies in our dataset

RFamide-related Peptide-3 and the Trade-off between Reproductive and Ingestive Behavior

Ingestive and sex behaviors are important for individual survival and reproductive success, but when environmental energy availability is limited, individuals of many different species make a trade-off, forfeiting sex for ingestive behavior. For example, food-deprived female Syrian hamsters (Mesocricetus auratus) forego vaginal scent marking and lordosis (sex behaviors) in favor of foraging, hoarding, and eating food (ingestive behavior). Reproductive processes tend to be energetically costly, and individual survival requires homeostasis in metabolic energy. Thus, during energetic challenges, the chances of survival are enhanced by decreasing the energy expended on reproductive processes. The entire hypothalamic-pituitary-gonadal (HPG) system is inhibited by severe energetic challenges, but comparatively little is known about the effects of mild energetic challenges. We hypothesized that (1) a trade-off is made between sex and ingestive behavior even when the level of food restriction is insufficient to inhibit the HPG system; (2) mild energetic challenges force a trade-off between appetitive ingestive and sex behaviors, but not consummatory versions of the same behaviors; and (3) the trade-off is orchestrated by ovarian steroid modulation of RFamide-related peptide 3 (RFRP-3). In other species, RFRP-3, an ortholog of avian gonadotropin-inhibitory hormone, is implicated in control of behavior in response to energetic challenges and stressful stimuli. In support of our three hypotheses, there is a "dose-response" effect of food restriction and re-feeding on the activation of RFRP-3-immunoreactive cells in the dorsomedial hypothalamus and on appetitive behaviors (food hoarding and sexual motivation), but not on consummatory behaviors (food intake and lordosis), with no significant effect on circulating levels of estradiol or progesterone. The effect of food restriction on the activation of RFRP-3 cells is modulated at the time of estrus in gonadally-intact females and in ovariectomized females treated with progesterone alone or with estradiol plus progesterone. Intracerebral treatment with RFRP-3 results in significant decreases in sexual motivation and results in significant but small increases in food hoarding in hamsters fed ad libitum. These and other results are consistent with the idea that ovarian steroids and RFRP-3 are part of a system that orchestrates trade-offs in appetitive behaviors in environments where energy availability fluctuates