Controlled Laboratory Generation of Atmospheric Black Carbon Using Laser Excitation-Based Soot Generator: From Basic Principles to Application Perspectives: A Review

The mimicking of atmospheric soot with versatile chemophysical properties is a critical issue in many applications, starting from instrument calibration, through producing aerosol standards for academic research, and ending with the reduction of uncertainties associated to carbonaceous particulate matter in the atmosphere, just to name a few. The present study deals with laser ablation as a novel and interesting technique for the generation of soot with high elementary carbon (EC) content with microphysical features similar to diesel or atmospheric soot and for modelling biomass emission under well-controlled laboratory conditions. The operation of the laser-excitation-based soot generator and the characteristics of the produced particles are compared to the most widely used techniques like flame, spark discharge generators, and real combustion soot originating from diesel- and aircraft engines or from field measurement. The comparison shows that significant differences in the physicochemical features exist between the real combustion soot and the soot originating from different excitation mechanisms. Moreover, the soot produced by different techniques shown also significant differences. However, due to some inherent and favorable attributes of the laser ablation technique—such as the possibility of the independent variation of physical characteristics of the generated soot particles—the potential for modelling biomass burning or to produce soot particles even in the accumulation mode makes it a useful tool in many cases

A végtagi vénás adaptáció mechanizmusai tartós orthosztatikus és inverz-orthosztatikus gravitációs terheléshez egészséges és kórós körülmények között = Mechanism of adaptation to long-term orthostatic and inverse-orthostatic gravitation loading in the extremity veins

Bizonyítékok sorát tártuk fel annak igazolására ill. megerősítésére, hogy orthosztatikus jellegű krónikus gravitációs terhelésre - esetenként inverz-orthosztatikus (mikrogravitás modell) is - patkány alsó végtagi vénák mindhárom rétege adaptációs jellegű microvesiculáris, myogen ill. innervációs változásokkal válaszol. E kísérletes eredmények egy részét, pl. a vénás endothelium micro-vesiculáris és a media myogen válaszai vonatkozásában, már humán érvizsgálatokkal is sikerült megerősíteni. Emberi kutatásokra fejlesztett új, non-invazív módszerünkkel alapvető információkat nyertünk számos nagyvéna disztenzibilitásának testhelyzet-, nyomás-, régió- és korfüggő sajátosságairól egészséges és beteg (postthrombotikus) egyének vonatkozásában. Mivel a vérkeringési rendszer gravitációs alkalmazkodó képességének megítélésében meghatározó fontos az artériás vérnyomás viselkedése, kombinált tilt-telemetriás módszereket és protokollokat fejlesztettünk ki rövid- és hosszú-távú orthosztatikus, valamint inverz-orthosztatikus kardiovaszkuláris hatások jellemzőinek ill. mechanizmusainak tanulmányozására éber patkányokban. Meglepetésre, mindkét testhelyzetben artériás hipertenzió a válasz, amely sympathicus efferens függő és specifikus gravitációs hatásokhoz kötött (nemspecifikus stressz effektusát kizártuk). Igazoltuk, hogy e válasz vestibulo-sympathicus reflex, amely néhány nap alatt adaptálódik a tilt pozícióhoz. Publikált munkák száma összesen 83, ebből 22 eredeti nemzetközi (IF: 23,531). | Experimental evidence has been provided to show that all three layers of rat hind limb veins respond to chronic orthostatic or inverse-orthostatic body position (ground-base model of microgravity) with adaptive microvesicular, myogenic, and neural changes. A part of these results (microvesicular properties of the venous endothelium, enhanced myogenic response) has been verified in human studies too. Using a new method developed by us for human investigations, information has been collected to characterize the distensibility of different healthy and diseased (postthrombotic) large veins in respect of body position, blood pressure, body region, and age. Taking into consideration, that arterial pressure response to gravitation stress is decisive in the ability of the organism to adapt, we developed combined techniques and protocols using telemetry, tilt-cages with appropriate rat models for studying the nature and mechanism of short- and long-term cardiovascular reactions to orthostatic and inverse-orthostatic effects. Interestingly, both of these body positions resulted in hypertension which proved to be dependent on intact sympathetic innervation and was connected with gravitation effects. Non-specific stress was excluded. It has been proven that vestibulo-sympathetic reflex activation plays a role in these blood pressure responses which adapt to the tilt-positions in a few days. Total number of publications: 83 with 22 original papers in international journals (IF: 23.531)

Indoleamine 2,3-Dioxygenase Activity in Chlamydia muridarum and Chlamydia pneumoniae Infected Mouse Lung Tissues

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Systemic administration of ivabradine, a hyperpolarization‐activated cyclic nucleotide‐gated channel inhibitor, blocks spontaneous absence seizures

Objective: Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are known to be involved in the generation of absence seizures (ASs), and there is evidence that cortical and thalamic HCN channel dysfunctions may have a proabsence role. Many HCN channel blockers are available, but their role in ASs has been investigated only by localized brain injection or in in vitro model systems due to their limited brain availability. Here, we investigated the effect on ASs of orally administered ivabradine (an HCN channel blocker approved for the treatment of heart failure in humans) following injection of the P-glycoprotein inhibitor elacridar, which is known to increase penetration into the brain of drug substrates for this efflux transporter. The action of ivabradine was also tested following in vivo microinjection into the cortical initiation network (CIN) of the somatosensory cortex and in the thalamic ventrobasal nucleus (VB) as well as on cortical and thalamocortical neurons in brain slices. Methods: We used electroencephalographic recordings in freely moving Genetic Absence Epilepsy Rats From Strasbourg (GAERSs) to assess the action of oral administration of ivabradine, with and without elacridar, on ASs. Ivabradine was also microinjected into the CIN and VB of GAERSs in vivo and applied to Wistar CIN and GAERS VB slices while recording patch-clamped cortical Layer 5/6 and thalamocortical neurons, respectively. Results: Oral administration of ivabradine markedly and dose-dependently reduced ASs. Ivabradine injection into CIN abolished ASs and elicited small-amplitude 4–7-Hz waves (without spikes), whereas in the VB it was less potent. Moreover, ivabradine applied to GAERS VB and Wistar CIN slices selectively decreased HCN channel-dependent properties of cortical Layer 5/6 pyramidal and thalamocortical neurons, respectively. Significance: These results provide the first demonstration of the antiabsence action of a systemically administered HCN channel blocker, indicating the potential of this class of drugs as a novel therapeutic avenue for ASs

Vanillin and vanillin analogs relax porcine coronary and basilar arteries by inhibiting L-type Ca2+ channels.

ABSTRACT Vanillin (VA) and vanillyl alcohol (VAA), components of natural vanilla, and ethyl vanillin (EtVA; synthetic analog) are used as flavoring agents and/or as additives by the food, cosmetic, or pharmaceutic industries. VA, VAA, and EtVA possess antioxidant and anti-inflammatory properties, but their vascular effects have not been determined. Therefore, we compared in isolated porcine coronary and basilar arteries the changes in isometric tension caused by VA, VAA, and EtVA. VA and its analogs caused concentration-dependent relaxations of both preparations during contractions from U46619 (9,11-dideoxy-11a,9a-epoxymethanoprostaglandin F2a, a thromboxane A 2 receptor agonist), and of coronary arteries contracted with KCl or endothelin-1. The order of potency was VAA , VA , EtVA. The Thus, in porcine arteries, relaxation from VA (and its analogs) is due to inhibition of L-type Ca 21 channels. Hence, these compounds could be used to relieve coronary or cerebral vasospasms due to exaggerated Ca 21 influx, but therapeutic efficacy would require exposures that far exceed the current levels obtained by the use of vanillin additives

Controlled Laboratory Generation of Atmospheric Black Carbon Using Laser Excitation-Based Soot Generator: From Basic Principles to Application Perspectives: A Review

The mimicking of atmospheric soot with versatile chemophysical properties is a critical issue in many applications, starting from instrument calibration, through producing aerosol standards for academic research, and ending with the reduction of uncertainties associated to carbonaceous particulate matter in the atmosphere, just to name a few. The present study deals with laser ablation as a novel and interesting technique for the generation of soot with high elementary carbon (EC) content with microphysical features similar to diesel or atmospheric soot and for modelling biomass emission under well-controlled laboratory conditions. The operation of the laser-excitation-based soot generator and the characteristics of the produced particles are compared to the most widely used techniques like flame, spark discharge generators, and real combustion soot originating from diesel- and aircraft engines or from field measurement. The comparison shows that significant differences in the physicochemical features exist between the real combustion soot and the soot originating from different excitation mechanisms. Moreover, the soot produced by different techniques shown also significant differences. However, due to some inherent and favorable attributes of the laser ablation technique—such as the possibility of the independent variation of physical characteristics of the generated soot particles—the potential for modelling biomass burning or to produce soot particles even in the accumulation mode makes it a useful tool in many cases