Transported vs. local contributions from secondary and biomass burning sources to PM2.5

Publication date: November 2016
Source:Atmospheric Environment, Volume 144
Author(s): Bong Mann Kim, Jihoon Seo, Jin Young Kim, Ji Yi Lee, Yumi Kim
The concentration of fine particulates in Seoul, Korea has been lowered over the past 10 years, as a result of the city's efforts in implementing environmental control measures. Yet, the particulate concentration level in Seoul remains high as compared to other urban areas globally. In order to further improve fine particulate air quality in the Korea region and design a more effective control strategy, enhanced understanding of the sources and contribution of fine particulates along with their chemical compositions is necessary. In turn, relative contributions from local and transported sources on Seoul need to be established, as this city is particularly influenced by sources from upwind geographic areas. In this study, PM2.5 monitoring was conducted in Seoul from October 2012 to September 2013. PM2.5 mass concentrations, ions, metals, organic carbon (OC), elemental carbon (EC), water soluble OC (WSOC), humic-like substances of carbon (HULIS-C), and 85 organic compounds were chemically analyzed. The multivariate receptor model SMP was applied to the PM2.5 data, which then identified nine sources and estimated their source compositions as well as source contributions. Prior studies have identified and quantified the transported and local sources. However, no prior studies have distinguished contributions of an individual source between transported contribution and locally produced contribution. We differentiated transported secondary and biomass burning sources from the locally produced secondary and biomass burning sources, which was supported with potential source contribution function (PSCF) analysis. Of the total secondary source contribution, 32% was attributed to transported secondary sources, and 68% was attributed to locally formed secondary sources. Meanwhile, the contribution from the transported biomass burning source was revealed as 59% of the total biomass burning contribution, which was 1.5 times higher than that of the local biomass burning source. Four-season average source contributions from the transported and the local sources were 28% and 72%, respectively.

Graphical abstract

from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/2c799Cj
via IFTTT

Aviation-attributable ozone as a driver for changes in mortality related to air quality and skin cancer

Publication date: November 2016
Source:Atmospheric Environment, Volume 144
Author(s): Sebastian D. Eastham, Steven R.H. Barrett
Aviation is a significant source of tropospheric ozone, which is a critical UV blocking agent, an indirect precursor to the formation of particulate matter, and a respiratory health hazard. To date, investigations of human health impacts related to aviation emissions have focused on particulate matter, and no global estimate yet exists of the combined health impact of aviation due to ozone, particulate matter and UV exposure changes. We use a coupled tropospheric-stratospheric chemical-transport model with a global aviation emissions inventory to estimate the total impact of aviation on all three risk factors. We find that surface ozone due to aviation emissions is maximized during hemispheric winter due to the greater wintertime chemical lifetime of ozone, but that a smaller enhancement of 0.5 ppbv occurs during summertime. This summertime increase results in an estimated 6,800 premature mortalities per year due to ozone exposure, over three times greater than previous estimates. During the winter maximum, interaction with high background NOx concentrations results in enhanced production of nitrate aerosol and increased annual average exposure to particulate matter. This ozone perturbation is shown to be the driving mechanism behind an additional 9,200 premature mortalities due to exposure to particulate matter. However, the increase in tropospheric ozone is also found to result in 400 fewer mortalities due to melanoma skin cancer in 2006. This is the first estimate of global melanoma mortality due to aviation, and the first estimate of skin cancer mortality impacts due to aviation using a global chemical transport model.



from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/2c793dD
via IFTTT

Editorial board

Publication date: October 2016
Source:Atmospheric Environment, Volume 142





from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/2bZ42qh
via IFTTT

Middle ear ventilation status postoperatively after translabyrinthine resection of vestibular schwannoma with mastoid obliteration and Eustachian tube occlusion: is the Eustachian tube enough to ventilate the middle ear without the mastoid air cell system?

Gas pressure balance is essential for maintaining normal middle ear function. The mucosal surfaces of the middle ear, the mastoid air cell system (MACS), and the Eustachian tube (ET) play a critical role in th...

from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/2bUqobh
via IFTTT

Transient resistance to DNA damaging agents is associated with expression of microRNAs-135b and -196b in human leukemia cell lines.

Related Articles

Transient resistance to DNA damaging agents is associated with expression of microRNAs-135b and -196b in human leukemia cell lines.

Int J Biochem Mol Biol. 2016;7(2):27-47

Authors: Ho TT, He X, Mo YY, Beck WT

Abstract
The acquisition of resistance to anticancer drugs is widely viewed as a key obstacle to successful cancer therapy. However, detailed knowledge of the initial molecular events in the response of cancer cells to these chemotherapeutic and stress responses, and how these lead to the development of chemoresistance, remains incompletely understood. Using microRNA array and washout and rechallenge experiments, we found that short term treatment of leukemia cells with etoposide led a few days later to transient resistance that was associated with a corresponding transient increase in expression of ABCB1 mRNA, as well as microRNA (miR)-135b and miR-196b. This phenomenon was associated with short-term exposure to genotoxic agents, such as etoposide, topotecan, doxorubicin and ionizing radiation, but not agents that do not directly damage DNA. Further, this appeared to be histiotype-specific, and was seen in leukemic cells, but not in cell lines derived from solid tumors. Treatment of leukemic cells with either 5-aza-deoxycytidine or tricostatin A produced similar increased expression of ABCB1, miR-135b, and miR-196b, suggesting a role for epigenetic regulation of this phenomenon. Bioinformatics analyses revealed that CACNA1E, ARHGEF2, PTK2, SIAH1, ARHGAP6, and NME4 may be involved in the initial events in the development of drug resistance following the upregulation of ABCB1, miR-135b and miR-196b. In summary, we report herein that short-term exposure of cells to DNA damaging agents leads to transient drug resistance, which is associated with elevations in ABCB1, miR-135b and miR-196b, and suggests novel components that may be involved in the development of anticancer drug resistance.

PMID: 27570640 [PubMed]

from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/2c6UMOe
via IFTTT

Pesg PNH diagnosis, follow-up and treatment guidelines.

Related Articles

Pesg PNH diagnosis, follow-up and treatment guidelines.

Am J Blood Res. 2016;6(2):19-27

Authors: Sahin F, Akay OM, Ayer M, Dal MS, Ertop S, Ilhan O, Karakus V, Ozcan MA, Ozkocaman V, Ozsan H, Salim O, Tobu M, Tombak A, Tuglular TF, Yilmaz M, Unal A, Yenerel MN, Saydam G

Abstract
PNH Education and Study Group (PESG) have been established in December 2013 as a non-profit, independent, medical organization www.pesg.org. Paroxysmal Nocturnal Hemoglobinuria (PNH) is a multi-systemic disease that should be treated with a multidisciplinary approach. Patients may apply to the clinics other than the hematology due to variability and diversity of clinical findings which lower the rate of diagnosis due to low awareness about PNH. PNH might be overlooked and diagnosis might be delayed. Regarding these, PESG was established with the collaboration of Immunology, Cardiology, Thorax Diseases (Pulmonology), Neurology, Gastroenterology, General Surgery and Urology specialists in addition to hematologists dealing with PNH. The PESG study group aims to increase the awareness about PNH, including training activities about PNH, strengthening the relations between clinics and planning of clinical studies as a goal. It is the first professional organization focusing on PNH, in Turkey.In this guideline, we want to facilitate the diagnosis attributes of physicians from all specializations that deal with PNH and its systemic complications. One can perceive this as a tailor made guideline of international guidelines but not a compilation.

PMID: 27570707 [PubMed]

from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/2c6UN4K
via IFTTT

The effect of aliskiren on the renal dysfunction following unilateral ureteral obstruction in the rat.

The effect of aliskiren on the renal dysfunction following unilateral ureteral obstruction in the rat.

Int J Physiol Pathophysiol Pharmacol. 2016;8(2):70-7

Authors: Hammad FT, Lubbad L

Abstract
PURPOSE: To investigate the effect of blocking renin-angiotensin system by direct renin inhibition using aliskiren on the renal dysfunction following reversible unilateral ureteral obstruction (UO).
METHODS: Wistar rats underwent reversible left UO for 72 hours. Group-Alsk (n=12) received aliskiren (30 mg/kg/day) dissolved in water starting one day before creating UO and continued until the terminal experiment five days post reversal when renal functions were measured using clearance techniques. Group-Vx (n=12) underwent similar protocol but had water only. Gene expression analysis of some markers of kidney injury was measured using PCR technique.
RESULTS: In Group-Vx, renal blood flow (RBF) and glomerular filtration rate (GFR) in the left kidney were significantly lower than the right kidney (1.82±0.12 vs. 3.19±0.40, P=0.001 and 0.81±0.08 vs. 1.44±0.09, P=0.004, respectively). However, left fractional excretion of sodium (FENa) was higher than the right FENa (0.80±0.15 vs. 0.55±0.04, P=0.05). Comparing the left obstructed kidney in Group-Alsk vs. Group-Vx, RBF and GFR were higher in Group-Alsk (2.44±0.30 vs. 1.82±0.12, P=0.049 and 1.02±0.11 vs. 0.81±0.08, P=0.07, respectively). The left renal FENa was lower in Group-Alsk but did not reach statistical significance (0.54±0.07 vs. 0.80±0.15, P=0.07). Aliskiren also decreased the gene expressions of NGAL, KIM-1 and p53.
CONCLUSION: Direct renin inhibition by aliskiren appears to have protective effect on the renal dysfunction and on the markers of renal injury following UO indicating a potential clinical benefit of this agent. Further, this data and the previous studies indicate that blocking renin-angiotensin system at any level has a protective effect in obstructive nephropathy.

PMID: 27570581 [PubMed]

from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/2c6V7jN
via IFTTT