We have studied the interaction forces and electrical conduction properties arising between multiwall carbon nanotube tips and the Au(111) surface in air, by means of amplitude modulation scanning force microscopy, also called intermittent contact. We have centered our work on tips with metallic electronic structure and for the specific parameters used we have found a preliminary interaction range where there is no contact between tip and surface. Stable imaging in this non-contact range is possible with multiwall carbon nanotube tips.
View Article and Find Full Text PDFObjective: Information on registers of children with special needs will be more meaningful if a validated measure of the severity of impact of a child's disability on life and family is included.
Design: We describe the development and initial validation of a parent-completed questionnaire (Generic Lifestyle Assessment Questionnaire LAQ-G) aimed at measuring such impact.
Results: Data were collected on 95 case children, representing various disabilities, and 65 control children without disability, and analysed for case-control, test-re-test and inter-reporter reliability.
Measurements of some of the main internal N-cycling processes in soil were obtained by labelling the inorganic N pool with the stable isotope of nitrogen ((15)N). The (15)N mean pool dilution technique, combined with other field measurements, enabled gross and net N-mineralization rates to be resolved in grassland soils, which had previously either received fertilizer N (F), or had remained unfertilized (U) for many years. The two soils were subdivided into plots that received N at different time intervals (over 3 weeks), prior to (15)N measurements being made.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
December 2002
Protein kinase C (PKC) regulation of l-ascorbic acid transport mediated by the Na+/ascorbic acid transporters, hSVCT1 and hSVCT2, expressed in COS-1 cells was studied using recombinant carboxyl-terminal V5 epitope-tagged forms of the transporters. The PKC activator phorbol 12-myristate 13-acetate (PMA) caused a time-dependent and concentration-dependent decrease (40-60%) in ascorbic acid transport activity. Effects of PMA were not observed with the inactive phorbol ester 4 alpha-phorbol and were reversed by treatment of the cells with the PKC-specific inhibitor Ro-31-8220.
View Article and Find Full Text PDFHairy polyps are rare tumours that can occur anywhere in the body. They are especially rare inthe pharynx. We report two cases of hairy polyps which originated from the nasopharynx.
View Article and Find Full Text PDFWe have previously reported that syntaxin 1A, a component of the presynaptic SNARE complex, directly modulates N-type calcium channel gating in addition to promoting tonic G-protein inhibition of the channels, whereas syntaxin 1B affects channel gating but does not support G-protein modulation (Jarvis, S. E., and Zamponi, G.
View Article and Find Full Text PDFIn this edition of Public Health, McClure and colleagues report on research that considered the criterion validity of indicators based on serious long bone fracture and length of stay in hospital. They found that neither were sensitive or specific indicators for serious injury as defined by an Injury Severity Score (ISS) of 16 or more. They contend that their study findings ' em leader strongly support a return to a measure similar in intent to that encapsulated in the original UK Green Paper em leader '.
View Article and Find Full Text PDFInt Urogynecol J Pelvic Floor Dysfunct
October 2002
Levator ani muscle function is traditionally evaluated by palpation or perioneometry. Recently, three different techniques of performing this task by translabial ultrasound have been described. The authors intended to validate these new methods by correlating results with assessments performed by perineometry and palpation.
View Article and Find Full Text PDFThe Child Health Network (CHN) for the Greater Toronto Area (GTA) is a partnership of hospital, rehabilitation and community providers committed to developing a regional system to deliver high quality, accessible, family-centred care for mothers, newborns, children and youth. This article reviews the history and model of the CHN, assesses its achievements, and provides insights into the challenges and lessons learned by the network. Stemming from the CHN's commitment to quality, accessibility and efficiency, regionalization of maternal, newborn and children's services is emerging as a success story.
View Article and Find Full Text PDFPublic Health
March 2002
The aim of the study was to develop a statistical method to derive a domain structure for the development of an impact of disability index, using multidimensional scaling of questionnaire items and expert and non-expert judgement of severity based on standardised videos. The participants were parents of children with cerebral palsy, parents of children in mainstream schools and clinicians with expertise in cerebral palsy, all accessed through child health services in the north east of England. The methods to create a weighted, domain structure for use with the impact of disability index were developed.
View Article and Find Full Text PDFChem Pharm Bull (Tokyo)
December 2001
Using atomic force microscopy (AFM), the length of the alpha-helix structure of poly-L-lysine was investigated by stretching the peptide directly, one molecule at a time. In the absence of urea, many rupturing points that seemed to be due to the breaking of some hydrogen bonds were observed in force-extension curves, while these points were never observed in the presence of 8 M urea. In the presence of 0.
View Article and Find Full Text PDFDiamidine drugs such as pentamidine and berenil (diminazene aceturate) are vital drugs for the treatment of early stage human African trypanosomiasis and the corresponding veterinary condition, respectively. The action of diamidines on trypanosomes is critically dependent on their efficient uptake by the parasite. We have therefore investigated the mode of uptake of pentamidine by Trypanosoma brucei brucei, using [(125)I]iodopentamidine as a permeant.
View Article and Find Full Text PDFInflux of Ca(2+) through presynaptic voltage-gated Ca(2+) channels is a key step in rapid neurotransmitter release. The amount of Ca(2+) entering through these channels is modulated by a plethora of intracellular messenger molecules, including betagamma-subunits of G proteins, and protein kinases. In addition, Ca(2+) channels bind physically to proteins of the vesicle-release machinery in a Ca(2+)-dependent manner, which can, in turn, regulate the activity of Ca(2+) channels.
View Article and Find Full Text PDFJ Laryngol Otol
June 2001
We report an unusual case of a mycotic external carotid artery aneurysm presenting in a nine-month-old infant. She presented with coryzal-like symptoms and oropharyngeal haemorrhage. This was thought initially to be due to acute tonsillitis.
View Article and Find Full Text PDFVitamin C is essential for many enzymatic reactions and also acts as a free radical scavenger. Specific non-overlapping transport proteins mediate the transport of the oxidized form of vitamin C, dehydroascorbic acid, and the reduced form, L-ascorbic acid, across biological membranes. Dehydroascorbic acid uptake is via the facilitated-diffusion glucose transporters, GLUT 1, 3 and 4, but under physiological conditions these transporters are unlikely to play a major role in the uptake of vitamin C due to the high concentrations of glucose that will effectively block influx.
View Article and Find Full Text PDFN-type Ca(2+) channels are modulated by a variety of G-protein-coupled pathways. Some pathways produce a transient, voltage-dependent (VD) inhibition of N channel function and involve direct binding of G-protein subunits; others require the activation of intermediate enzymes and produce a longer-lasting, voltage-independent (VI) form of inhibition. The ratio of VD:VI inhibition differs significantly among cell types, suggesting that the two forms of inhibition play unique physiological roles in the nervous system.
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