Extracellular ATP-induced NO production and its dependence on membrane Ca2+ flux in Salvia miltiorrhiza hairy roots

Extracellular ATP (eATP) is a novel signalling agent, and nitric oxide (NO) is a well-established signal molecule with diverse functions in plant growth and development. This study characterizes NO production induced by exogenous ATP and examines its relationship with other important signalling agents, Ca2+ and H2O2 in Salvia miltiorrhiza hairy root culture. Exogenous ATP was applied at 10–500 μM to the hairy root cultures and stimulated NO production was detectable within 30 min. The NO level increased with ATP dose from 10–100 μM but decreased from 100–200 μM or higher. The ATP-induced NO production was mimicked by a non-hydrolysable ATP analogue ATPγS, but only weakly by ADP, AMP or adenosine. The ATP-induced NO production was blocked by Ca2+ antagonists, but not affected by a protein kinase inhibitor. ATP also induced H2O2 production, which was dependent on both Ca2+ and protein kinases, and also on NO biosynthesis. On the other hand, ATP induced a rapid increase in the intracellular Ca2+ level, which was dependent on NO but not H2O2. The results suggest that NO is implicated in ATP-induced responses and signal transduction in plant cells, and ATP signalling is closely related to Ca2+ and ROS signalling

Modelling of photonic wire Bragg Gratings

Some important properties of photonic wire Bragg grating structures have been investigate. The design, obtained as a generalisation of the full-width gap grating, has been modelled using 3D finite-difference time-domain simulations. Different types of stop-band have been observed. The impact of the grating geometry on the lowest order (longest wavelength) stop-band has been investigated - and has identified deeply indented configurations where reduction of the stop-bandwidth and of the reflectivity occurred. Our computational results have been substantially validated by an experimental demonstration of the fundamental stop-band of photonic wire Bragg gratings fabricated on silicon-on-insulator material. The accuracy of two distinct 2D computational models based on the effective index method has also been studied - because of their inherently much greater rapidity and consequent utility for approximate initial designs. A 2D plan-view model has been found to reproduce a large part of the essential features of the spectral response of full 3D models

Broadband Reconfiguration of OptoMechanical Filters

We demonstrate broad-band reconfiguration of coupled photonic crystal nanobeam cavities by using optical gradient force induced mechanical actuation. Propagating waveguide modes that exist over wide wavelength range are used to actuate the structures and in that way control the resonance of localized cavity mode. Using this all-optical approach, more than 18 linewidths of tuning range is demonstrated. Using on-chip temperature self-referencing method that we developed, we determined that 20 % of the total tuning was due to optomechanical reconfiguration and the rest due to thermo-optic effects. Independent control of mechanical and optical resonances of our structures, by means of optical stiffening, is also demonstrated

Allergic rhinitis: evidence for impact on asthma

BACKGROUND: This paper reviews the current evidence indicating that comorbid allergic rhinitis may have clinically relevant effects on asthma. DISCUSSION: Allergic rhinitis is very common in patients with asthma, with a reported prevalence of up to 100% in those with allergic asthma. While the temporal relation of allergic rhinitis and asthma diagnoses can be variable, the diagnosis of allergic rhinitis often precedes that of asthma. Rhinitis is an independent risk factor for the subsequent development of asthma in both atopic and nonatopic individuals. Controlled studies have provided conflicting results regarding the benefits for asthma symptoms of treating comorbid allergic rhinitis with intranasal corticosteroids. Effects of other treatments for comorbid allergic rhinitis, including antihistamines, allergen immunotherapy, systemic anti-IgE therapy, and antileukotriene agents, have been examined in a limited number of studies; anti-IgE therapy and antileukotriene agents such as the leukotriene receptor antagonists have benefits for treating both allergic rhinitis and asthma. Results of observational studies indicate that treating comorbid allergic rhinitis results in a lowered risk of asthma-related hospitalizations and emergency visits. Results of several retrospective database studies in the United States and in Europe indicate that, for patients with asthma, the presence of comorbid allergic rhinitis is associated with higher total annual medical costs, greater prescribing frequency of asthma-related medications, as well as increased likelihood of asthma-related hospital admissions and emergency visits. There is therefore evidence suggesting that comorbid allergic rhinitis is a marker for more difficult to control asthma and worsened asthma outcomes. CONCLUSION: These findings highlight the potential for improving asthma outcomes by following a combined therapeutic approach to comorbid allergic rhinitis and asthma rather than targeting each condition separately

Effects of controlled diesel exhaust exposure on apoptosis and proliferation markers in bronchial epithelium – an in vivo bronchoscopy study on asthmatics, rhinitics and healthy subjects

BackgroundEpidemiological evidence demonstrates that exposure to traffic-derived pollution worsens respiratory symptoms in asthmatics, but controlled human exposure studies have failed to provide a mechanism for this effect. Here we investigated whether diesel exhaust (DE) would induce apoptosis or proliferation in the bronchial epithelium in vivo and thus contribute to respiratory symptoms.MethodsModerate (n?=?16) and mild (n?=?16) asthmatics, atopic non-asthmatic controls (rhinitics) (n?=?13) and healthy controls (n?=?21) were exposed to filtered air or DE (100 ?g/m 3 ) for 2 h, on two separate occasions. Bronchial biopsies were taken 18 h post-exposure and immunohistochemically analysed for pro-apoptotic and anti-apoptotic proteins (Bad, Bak, p85 PARP, Fas, Bcl-2) and a marker of proliferation (Ki67). Positive staining was assessed within the epithelium using computerized image analysis.ResultsNo evidence of epithelial apoptosis or proliferation was observed in healthy, allergic or asthmatic airways following DE challenge.ConclusionIn the present study, we investigated whether DE exposure would affect markers of proliferation and apoptosis in the bronchial epithelium of asthmatics, rhinitics and healthy controls, providing a mechanistic basis for the reported increased airway sensitivity in asthmatics to air pollutants. In this first in vivo exposure investigation, we found no evidence of diesel exhaust-induced effects on these processes in the subject groups investigated

Greater risk of incident asthma cases in adults with Allergic Rhinitis and Effect of Allergen Immunotherapy: A Retrospective Cohort Study

Asthma and rhinitis are often co-morbid conditions. As rhinitis often precedes asthma it is possible that effective treatment of allergic rhinitis may reduce asthma progression. The aim of our study is to investigate history of allergic rhinitis as a risk factor for asthma and the potential effect of allergen immunotherapy in attenuating the incidence of asthma. Hospital-referred non-asthmatic adults, aged 18–40 years between 1990 and 1991, were retrospectively followed up until January and April 2000. At the end of follow up, available subjects were clinically examined for asthma diagnosis and history of allergen specific immunotherapy, second-hand smoking and the presence of pets in the household. A total of 436 non-asthmatic adults (332 subjects with allergic rhinitis and 104 with no allergic rhinitis nor history of atopy) were available for final analyses. The highest OR (odds ratio) associated with a diagnosis of asthma at the end of follow-up was for the diagnosis of allergic rhinitis at baseline (OR, 7.8; 95%CI, 3.1–20.0 in the model containing the covariates of rhinitis diagnosis, sex, second-hand smoke exposure, presence of pets at home, family history of allergic disorders, sensitization to Parietaria judaica; grass pollen; house dust mites; Olea europea: orchard; perennial rye; and cat allergens). Female sex, sensitization to Parietaria judaica and the presence of pets in the home were also significantly predictive of new onset asthma in the same model. Treatment with allergen immunotherapy was significantly and inversely related to the development of new onset asthma (OR, 0.53; 95%CI, 0.32–0.86). In the present study we found that allergic rhinitis is an important independent risk factor for asthma. Moreover, treatment with allergen immunotherapy lowers the risk of the development of new asthma cases in adults with allergic rhinitis

Photonic band gaps in materials with triply periodic surfaces and related tubular structures

We calculate the photonic band gap of triply periodic bicontinuous cubic structures and of tubular structures constructed from the skeletal graphs of triply periodic minimal surfaces. The effect of the symmetry and topology of the periodic dielectric structures on the existence and the characteristics of the gaps is discussed. We find that the C(I2-Y**) structure with Ia3d symmetry, a symmetry which is often seen in experimentally realized bicontinuous structures, has a photonic band gap with interesting characteristics. For a dielectric contrast of 11.9 the largest gap is approximately 20% for a volume fraction of the high dielectric material of 25%. The midgap frequency is a factor of 1.5 higher than the one for the (tubular) D and G structures

Nanostructures, Technology, Research, and Applications

Contains reports on twenty research projects and a list of publications.Joint Services Electronics Program Grant DAAH04-95-1-0038National Science Foundation Grant ECS-94-07078Semiconductor Research CorporationU.S. Army Research Office Grant DAAH04-95-1-0564Defense Advanced Research Projects Agency/Naval Air Systems Command Contract N00019-95-K-0131National Aeronautics and Space Administration Contract NAS8-38249National Aeronautics and Space Administration Grant NAGW-2003IBM Corporation Contract 1622National Science Foundation Graduate FellowshipU.S. Navy - Office of Naval Research Grant N00014-95-1-1297U.S. Army Research Office Contract DAAH04-94-G-0377U.S. Air Force - Office of Scientific Research Grant F49620-92-J-0064U.S. Air Force - Office of Scientific Research Grant F49620-95-1-0311National Science Foundation Contract DMR 94-0034U.S. Air Force - Office of Scientific Research Contract F49620-96-0126Harvard-Smithsonian Astrophysical Observatory Contract SV630304National Aeronautics and Space Administration Grant NAG5-5105Los Alamos National Laboratory Contract E57800017-9