Secondary wall thickenings in tracheary elements were specifically stained by incubation of Arabidopsis and maize in Silver Stain Plus (Bio-Rad) staining solution, after pretreatment with SDS and ethanol solution. Scanning electron microscopic analysis of sections of celery revealed that silver particles were deposited on the secondary wall thickenings, indicating that the staining was due to t...

objective:at the present study, relationship between phagocytosis of plga particles and combined effects of particle size and surface pegylation was investigated.  materials and methods:microspheres and nanospheres (3500 nm and 700 nm) were prepared from three types of plga polymers (non-pegylated and pegylation percents of 9% and 15%). these particles were prepared by solvent evaporation metho...

[1] Aircraft-based measurements of aerosol composition, either bulk or single-particle, and both subsaturated and supersaturated hygroscopicity were made in the Los Angeles Basin and its outflows during May 2010 during the CalNex field study. Aerosol composition evolves from source-rich areas in the western Basin to downwind sites in the eastern Basin, evidenced by transition from an external t...

Primary organic aerosol (POA) and associated vapors can play an important role in determining the formation and properties of secondary organic aerosol (SOA). If SOA and POA are miscible, POA will significantly enhance SOA formation and some POA vapor will incorporate into SOA particles. When the two are not miscible, condensation of SOA on POA particles forms particles with complex morphology....

Viruses can spread by different mechanisms: via intracellular particles through cell junctions to neighboring cells or via secreted virions to adjacent or remote cells. The observation of clusters of hepadnavirus-infected cells both in vivo and in primary hepatocytes neither proves the first mechanism nor excludes the second. In order to test which mechanism, if not both, is used by hepatitis B...

[1] The cloud condensation nucleus (CCN) activity of organic-sulfate particles was investigated using a steadystate environmental chamber. The organic component consisted of secondary organic aerosol (SOA) generated in the dark from 24 ± 2 ppb a-pinene for conditions of 300 ± 5 ppb ozone, 40 ± 2% relative humidity, and 25 ± 1 C, with the organic mass loading in the chamber ranging from 23 to 37...

The effects of microplastics on zooplankton are an increasing environmental concern. Both primary microplastics that are produced as constituents of cosmetic products, as well as secondary microplastics that are formed by degradation of larger plastic debris, are ubiquitous in aquatic environments. Today, primary microplastics are being phased out and replaced by plant-derived bioplastics. Whet...

We studied the OH oxidation of submicron aerosol particles consisting of pure palmitic acid (PA) or thin (near monolayer) coatings of PA on aqueous and effloresced inorganic salt particles. Experiments were performed as a function of particle size and OH exposure using a continuous-flow photochemical reaction chamber coupled to a chemical 5 ionization mass spectrometer (CIMS) system, for detect...

Measurements on the composition of nanometersized atmospheric particles are the key to understand which vapors participate in the secondary aerosol formation processes. Knowledge on these processes is crucial in assessing the climatic effects of secondary aerosol formation. We present data of >2 nm particle concentrations and their water-affinity measured with the Condensation Particle Counter ...

[1] Laboratory experiments investigated the relationship between oxidation level and hygroscopic properties of secondary organic aerosol (SOA) particles generated via OH radical oxidation in an aerosol flow reactor. The hygroscopic growth factor at 90% RH (HGF90%), the CCN activity ( ORG,CCN) and the level of oxidation (atomic O:C ratio) of the SOA particles were measured. Both HGF90% and ORG,C...