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Notes: Field emission from isolated individual vertically aligned carbon nanocones (VACNCs) has been measured using a small-diameter moveable probe. The probe was scanned parallel to the sample plane to locate the VACNCs, and perpendicular to the sample plane to measure the emission turn-on electric field of each VACNC. Individual VACNCs can be good field emitters. The emission threshold field depends on the geometric aspect ratio (height/tip radius) of the VACNC and is lowest when a sharp tip is present. VACNCs exposed to a reactive ion etch process demonstrate a lowered emission threshold field while maintaining a similar aspect ratio. Individual VACNCs can have low emission thresholds, carry high current densities, and have long emission lifetime. This makes them very promising for various field emission applications for which deterministic placement of the emitter with submicron accuracy is needed. © 2002 American Institute of Physics.

Notes: . Vairimorpha invictae n. sp. infects the red imported fire ant, Solenopsis invicta Buren, in Brazil. The parasite is dimorphic, producing two morphologically distinct types of spores, which develop sequentially in the same fat cells or oenocytes in the fat body. The binucleate free spores develop from disporous sporonts; the uninucleate octospores develop from multinucleate sporonts within a sporophorous vesicle. Infected cells are transformed into large sacs which contain both types of spores in mature adult hosts. Mature free spores are often present by the time the larvae pupate, but mature octospores are found only in adult hosts. Masses of spores may be seen through the intact cuticle by low power phase-contrast microscopy; there are no other physical signs and no behavioral signs of infection. Attempts to transmit the infection in the laboratory failed.

Notes: Abstract: We have previously developed an in vitro model for traumatic brain injury that simulates a major component of in vivo trauma, that being tissue strain or stretch. We have validated our model by demonstrating that it produces many of the posttraumatic responses observed in vivo. Sustained elevation of the intracellular free calcium concentration ([Ca2+]i) has been hypothesized to be a primary biochemical mechanism inducing cell dysfunction after trauma. In the present report, we have examined this hypothesis in astrocytes using our in vitro injury model and fura-2 microphotometry. Our results indicate that astrocyte [Ca2+]i is rapidly elevated after stretch injury, the magnitude of which is proportional to the degree of injury. However, the injury-induced [Ca2+]i elevation is not sustained and returns to near-basal levels by 15 min postinjury and to basal levels between 3 and 24 h after injury. Although basal [Ca2+]i returns to normal after injury, we have identified persistent injury-induced alterations in calcium-mediated signal transduction pathways. We report here, for the first time, that traumatic stretch injury causes release of calcium from inositol trisphosphate-sensitive intracellular calcium stores and may uncouple the stores from participation in metabotropic glutamate receptor-mediated signal transduction events. We found that for a prolonged period after trauma astrocytes no longer respond to thapsigargin, glutamate, or the inositol trisphosphate-linked metabotropic glutamate receptor agonist trans-(1S,3R)-1-amino-1,3-cyclopentanedicarboxylic acid with an elevation in [Ca2+]i. We hypothesize that changes in calcium-mediated signaling pathways, rather than an absolute elevation in [Ca2+]i, is responsible for some of the pathological consequences of traumatic brain injury.

Notes: Objective To evaluate the efficacy and safety of a suppressive course of acyclovir in late pregnancy in women with recurrent genital herpes infection on the incidence of viral shedding, herpes lesion development and caesarean section for recurrent genital herpes.Design Double-blind, randomised placebo controlled clinical trial.Setting Adepartment of genitourinary medicine in Sheffield and an antenatal clinic in London.Population Pregnant women with recurrent genital herpes infection at 〈 36 weeks of gestation.Methods Participating women were given acyclovir 200 mg four times a day (or matching placebo) from 36 weeks of gestation until the time of delivery. Women were seen weekly and viral cultures were obtained from the cervix and vulva. Decisions regarding mode of delivery were left to the discretion of the attending obstetrician.Main outcome measures Delivery by caesarean section for recurrent genital herpes infection. Number of episodes of recurrent genital herpes infection and number of episodes of asymptomatic viral shedding during the treatment period. In addition blood was taken at two weekly intervals to determine acyclovir levels.Results The total number of women recruited was 63 (3 1 received acyclovir and 32 received placebo). The number of women undergoing delivery by caesarean section for recurrent herpes at the time of delivery was 12 (19%). The odds ratio for delivery by caesarean section in women taking acyclovir, compared with those talung placebo, was 0.44 (95% CI 0.09–1.59). The odds ratio for clinical recurrences during treatment was 0.10 (95% confidence interval 0.00–0.86) and the odds ratio for clinical recurrence or asymptomatic shedding during treatment was 0.32 (95% CI 0.05–1.56).Conclusion This trial was unable to demonstrate that acyclovir can significantly decrease the number of caesarean section deliveries; however, the number of clinical recurrences was significantly reduced. Two episodes of asymptomatic virus shedding both occurred in women taking acyclovir. At the present time there is little evidence to suggest that acyclovir should be used outside randomised controlled trials for the suppression of recurrent genital herpes infection during pregnancy.

Notes: We report on the operation of an integrated gated cathode device using a single vertically aligned carbon nanofiber as the field emission element. This device is capable of operation in a moderate vacuum for extended periods of time without experiencing a degradation of performance. Less than 1% of the total emitted current is collected by the gate electrode, indicating that the emitted electron beam is highly collimated. As a consequence, this device is ideal for applications that require well-focused electron emission from a microscale structure. © 2001 American Institute of Physics.

Notes: Several studies have reported devitalization of teeth following surgical procedures in the area of the root apices. The purpose of this investigation was to observe the 1–4-week wound healing pattern in monkey dental tissues following intentional vital apicoectomy (IVA). Two adult Macaca mulatta were used in this study. All of the teeth were surgically transected within the apical one-third with a bur. The soft tissues were then closed. At death, a maxillary and a mandibular quadrant for 1, 2, 1 and 4 weeks following surgery were obtained after vascular perfusion. Each quadrant was demineralized in HDTA, processed, serially sectioned at 7 μm and alternately stained with hematoxylin and eosin, Preece's modified trichome, and McKay's bacterial stains. Examination of sequential IVA cuts showed an initial disruption of the pulpal neurovascular supply resulting in pulpal necrosis. The pulpal tissue underwent a process of replacement with PDL-like connective tissues and deposition of cementum on all cut dentin surfaces of the tooth roots as well as in some of the pulp chambers No abscesses, external resorption or ankylosis were found.