Aerosol flow pattern and emission obtained in two variants of aerolizer/cyclohaler DPI was modeled using CFD at the standard airflow rate of 100L/min. Airflow was analyzed with k-ε turbulence model ...on the unstructured numerical meshes with more than 0.5 million elements. Dynamics of aerosol particles with the size of 1-10μm were analyzed with the Lagrangian approach. The results of simulations showed that aerosol particles get stronger rotation and higher centrifugal velocities in the DPI with the longer mouthpiece. This inertial effect results in a higher deposition of fine particles (2-4μm) in the inhaler mouthpiece and in the adjacent outer space. Theoretical predictions were verified by high-speed video recordings of the aerosol cloud released from both studied DPIs. It is concluded that the application of the modified cyclohaler with the short mouthpiece may be beneficial for a more efficient delivery of fine particles to the lower respiratory tract.
Background and Aims
Eutypa and Botryosphaeria dieback are diseases that affect vineyards worldwide, reducing productivity and longevity. The ability of the causal pathogens Eutypa lata and Diplodia ...seriata to colonise grapevine canes was investigated in the search for resistance or tolerance to trunk diseases.
Methods and Results
Visual assessments of 174 winegrape cultivars (Vitis vinifera) in a mature germplasm collection in the Barossa Valley in South Australia revealed substantial variation (0–98%) in severity of foliar symptoms and dieback. A selection of 18 cultivars representing those without symptoms or low (<10%) severity was compared with the susceptible cultivars Shiraz and Sauvignon Blanc. Inoculation of canes in situ in the vineyard and detached canes in the greenhouse, confirmed variability among cultivars for the extent of pathogen colonisation.
Conclusions
Cultivars varied in susceptibility to colonisation by E. lata and D. seriata, with some differences between the two pathogens in terms of the ranking of cultivars. Muscadelle was most resistant to colonisation by both pathogens, and Sauvignonasse was the most susceptible.
Significance of the Study
Knowledge of cultivar susceptibility to grapevine trunk diseases will assist in prioritisation of disease management strategies. Identification of cultivars with resistance could inform selection of planting material and may lead to improved breeding programs in the future.
A broader use of carbon nanomaterials increases the risk of their inhalation as aerosol dispersed in the air. Inhaled nanometer-sized particles are known to penetrate to the pulmonary region where ...they interact with the lung surfactant as the first barrier they meet and eventually penetrate to the surface of the cellular layer. This study presents the results of experimental studies of physicochemical interactions between several types of carbon nanomaterials (nanotubes and nanohorns of various size and surface properties) and lipid layers in two qualitatively different experimental systems: Langmuir trough and pulsated drop tensiometer, both providing complementary possibilities to study interfacial properties of the lipid-rich layer. Quantified alterations in mechanical properties if lipid films (equilibrium compressibility, dynamic surface elasticity, and viscosity) indicate that nanocarbons with different wettability may induce concentration-dependent frustration of the lung surfactant and biological membranes in vivo. The observed effects are discussed not only in relation to health effects from nanoparticle inhalation but also to potential medical applications of engineered carbon nanomaterials.
Background and Aims
Grapevine trunk diseases, caused by fungal pathogens that infect pruning wounds, pose a major threat to the sustainability of vineyards throughout the world. Pruning wound ...protectants can control infection, but little is known about the optimal timing of application of protectants following pruning. In this study, the timing of fungicide application to pruning wounds was evaluated to assess curative and preventative effects.
Methods and Results
To assess curative control, on the day of pruning, wounds were inoculated with ascospores of Eutypa lata or conidia of Neofusicoccum luteum followed 1, 3 or 6 days later by application of the fungicides tebuconazole, pyraclostrobin or fluazinam. To assess preventative control, fresh pruning wounds were treated with the same fungicides, then inoculated 1, 6 or 14 days later. The fungicides provided curative control of both pathogens for up to 6 days and preventative control of E. lata for up to 6 days and of N. luteum for up to 14 days.
Conclusion
These results indicate that fungicides can provide control of trunk disease pathogens when applied up to 6 days after wound infection, and continue to protect wounds for up to 14 days after application.
Significance of the Study
Current recommendations to protect grapevine pruning wounds from trunk disease pathogens are to apply protectants within 24 h of pruning. This study suggests that a single application of the fungicides tested 6 days after pruning may provide up to 3 weeks of wound protection, thereby offering improved flexibility in managing grapevine trunk disease.
Nanosized objects can be used as the drug carriers with specific functionalities which are introduced to the body via the respiratory system, i.e., by inhalation. They can be carried in as aerosol ...nanoparticles (NPs), nanostructured particles (NSPs) or components of nanosuspensions atomized into micrometer-sized droplets. In the first part of the paper physical factors required for the effective inhalation of nanocarriers are discussed, including the flow dynamics of NPs and NSPs in the respiratory tract. Selected problems related to designing of the required properties of inhalable drug carriers are also addressed. In the next part of the paper, the importance of direct physicochemical interactions between deposited nanoparticles and pulmonary fluids (pulmonary surfactant and bronchial mucus) is emphasized. This perspective allows for a more rational definition of the efficient strategies of the delivery of nanoparticle drug carriers via inhalation.
Background and Aims
Angular leaf scorch (ALS), caused by the fungus Pseudopezicula tetraspora, is an exotic disease threat to the $45 billion Australian wine industry. Research was undertaken at the ...Cornell University New York State Agricultural Experiment Station in Geneva, NY, USA to develop contingency plans for the Australian wine industry in the event of an ALS incursion.
Methods and Results
Evaluation of Vitis vinifera cultivars widely grown in Australia revealed that Riesling, Sauvignon Blanc, Cabernet Sauvignon and Pinot Noir have moderate to high susceptibility to infection by P. tetraspora. The fungicides trifloxystrobin, pyraclostrobin and tebuconazole were shown to be effective at controlling ALS. A drastic pruning eradication strategy was successfully validated for ALS, resulting in no disease recurrence within 3 years of the initial eradication protocol.
Conclusions
Cultivars grown in Australia ranged in susceptibility to ALS. Fungicides available in Australia are effective and could be used to control ALS in the event of an incursion. The drastic pruning strategy will be included in the Australian Viticulture Industry Biosecurity Plan for potential implementation as part of an incursion response.
Significance of the Study
This research contributes to the biosecurity capability of the Australian viticulture industry and to improved industry preparedness. It has the potential to reduce production losses and vineyard re‐establishment costs, while maintaining the competitive advantage conferred by freedom from exotic diseases.
Foliar symptoms of Eutypa dieback, caused by Eutypa lata, in grapevines, cv. Shiraz, varied from year to year in a 6-year study conducted in South Australia and, although trends were similar for ...vineyards within geographical regions, differences were observed between regions. We attempted to elucidate the causes underlying this variation and hypothesized that it was influenced by climatic factors. A number of possible relationships were identified between climate and symptom expression: (i) increased symptom expression was related to increased winter rainfall 18 months earlier, (ii) decreased disease incidence and prevalence were related to increased temperature in spring, and (iii) a reduction in disease incidence was related to both very high and very low rainfall in October. Theories for these relationships are proposed and require further investigation. A conceptual model was developed which requires validation and has the potential to predict the incidence of foliar symptoms of Eutypa dieback. Information from this study could lead to an improved integrated pest management system to suppress foliar symptoms and sustain productivity of vines infected with E. lata.
The article discusses selected issues related to construction and performance of dry powder inhalers with the spinning capsule: Aerolizer® and cyclohaler. Investigations involved devices and capsules ...found among medicinal products available on the domestic market. Based on scanning electron microscope images, the following were determined: (i) shape and crosssection of needles used to puncture drug-containing capsules as well as (ii) size, geometry and cross-section of small holes in the capsules through which powder is introduced into the airstream while using the inhaler. It was found that differences in shape and spatial arrangement of needles affect both the total area of holes and the character of perforation. In Aerolizer® inhalers, the average area of holes is 1.3 mm2 at each side of the capsule, and oval through holes are obtained. In investigated cyclohaler-type inhalers, the average hole area ranges from 1.6 to 2.2 mm2, and perforations are partly covered by torn fragments of the capsule. It has been determined that both the type of needles and inherent properties of the material from which capsules are made have an impact on observed effects. The authors have also assessed the potential influence of differences in the manner of perforation and applied capsule material on even powder release and aerosol generation in the device. Also, attention has been paid to other significant features of inhaler devices and powder formulations which decide about effective inhalation drug delivery to the respiratory system.
Direct physicochemical interactions between the major components of electronic cigarette liquids (e-liquids): glycerol (VG) and propylene glycol (PG), and lung surfactant (LS) were studied by ...determining the dynamic surface tension under a simulated breathing cycle using drop shape method. The studies were performed for a wide range of concentrations based on estimated doses of e-liquid aerosols (up to 2500 × the expected nominal concentrations) and for various VG/PG ratios. The results are discussed as relationships among mean surface tension, surface tension amplitude, and surface rheological properties (dilatational elasticity and viscosity) versus concentration and composition of e-liquid. The results showed that high local concentrations (>200 × higher than the estimated average dose after a single puffing session) may induce measurable changes in biophysical activity of LS; however, only ultra-high e-liquid concentrations inactivated the surfactant. Physiochemical characterization of e-liquids provide additional insights for the safety assessment of electronic nicotine delivery systems (ENDS).
The generalist ascomycete fungus Eutypa lata causes Eutypa dieback of grapevine (Vitis vinifera) worldwide. To decipher the cosmopolitan distribution of this fungus, the population genetic structure ...of 17 geographic samples was investigated from four continental regions (Australia, California, Europe and South Africa), based on analysis of 293 isolates genotyped with nine microsatellite markers. High levels of haplotypic richness (R = 0·91–1) and absence of multilocus linkage disequilibrium among loci supported the preponderance of sexual reproduction in all regions examined. Nonetheless, the identification of identical multilocus haplotypes with identical vegetative compatibility groups, in some vineyards in California and South Africa, suggests that asexual dispersal of the fungus among neighbouring plants could be a rare means of disease spread. The greatest levels of allelic richness (A = 4·89–4·97) and gene diversity (H = 0·66–0·69) were found in Europe among geographic samples from coastal areas surrounding the Mediterranean Sea, whereas the lowest genetic diversity was found in South Africa and Australia (A = 2·78–3·74; H = 0·49–0·57). Samples from California, Australia and South Africa, which had lower genetic diversity than those of Europe, were also characterized by demographic disequilibrium and, thus, may represent founding populations of the pathogen. Low but significant levels of genetic differentiation among all samples (DEST = 0·12, P = 0·001; FST = 0·03, P = 0·001) are consistent with historical gene flow preventing differentiation at continental scales. These findings suggest that global, human‐mediated spread of the fungus may have resulted in its current global distribution.
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