9 resultados para size-fractionated iron
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Characterization and source apportionment of organic aerosol using offline aerosol mass spectrometry
Resumo:
Field deployments of the Aerodyne Aerosol Mass Spectrometer (AMS) have significantly advanced real-time measurements and source apportionment of non-refractory particulate matter. However, the cost and complex maintenance requirements of the AMS make its deployment at sufficient sites to determine regional characteristics impractical. Furthermore, the negligible transmission efficiency of the AMS inlet for supermicron particles significantly limits the characterization of their chemical nature and contributing sources. In this study, we utilize the AMS to characterize the water-soluble organic fingerprint of ambient particles collected onto conventional quartz filters, which are routinely sampled at many air quality sites. The method was applied to 256 particulate matter (PM) filter samples (PM1, PM2:5, and PM10, i.e., PM with aerodynamic diameters smaller than 1, 2.5, and 10 μm, respectively), collected at 16 urban and rural sites during summer and winter. We show that the results obtained by the present technique compare well with those from co-located online measurements, e.g., AMS or Aerosol Chemical Speciation Monitor (ACSM). The bulk recoveries of organic aerosol (60–91 %) achieved using this technique, together with low detection limits (0.8 μg of organic aerosol on the analyzed filter fraction) allow its application to environmental samples. We will discuss the recovery variability of individual hydrocarbon ions, ions containing oxygen, and other ions. The performance of such data in source apportionment is assessed in comparison to ACSM data. Recoveries of organic components related to different sources as traffic, wood burning, and secondary organic aerosol are presented. This technique, while subjected to the limitations inherent to filter-based measurements (e.g., filter artifacts and limited time resolution) may be used to enhance the AMS capabilities in measuring size-fractionated, spatially resolved longterm data sets.
Resumo:
Purpose To evaluate the efficacy and toxicity of stereotactic fractionated radiotherapy (SFRT) for patients with pituitary macroadenoma (PMA). Methods and Materials Between March 2000 and March 2009, 27 patients (male to female ratio, 1.25) with PMA underwent SFRT (median dose, 50.4 Gy). Mean age of the patients was 56.5 years (range, 20.3 - 77.4). In all but one patient, SFRT was administered for salvage treatment after surgical resection (transphenoidal resection in 23, transphenoidal resection followed by craniotomy in 2 and multiple transphenoidal resections in another patient). In 10 (37%) patients, the PMAs were functional (3 ACTH-secreting, 3 prolactinomas, 2 growth hormone-secreting and 2 multiple hormone-secretion). Three (11.1%) and 9 (33.3%) patients had PMA abutting and compressing the optic chiasm, respectively. Mean tumor volume was 2.9 ± 4.6 cm3. Eighteen (66.7%) patients had hypopituitarism prior to SFRT. The mean follow-up period after SFRT was 72.4 ± 37.2 months. Results Tumor size decreased for 6 (22.2%) patients and remained unchanged for 19 (70.4%) other patients. Two (7.4%) patients had tumor growth inside the prescribed treatment volume. The estimated 5-year tumor growth control was 95.5% after SFRT. Biochemical remission occurred in 3 (30%) patients with functional PMA. Two patients with normal anterior pituitary function before SFRT developed new deficits 25 and 65 months after treatment. The 5-year survival without new anterior pituitary deficit was thus 95.8%. Five patients with visual field defect had improved visual function and 1 patient with no visual defect prior to SFRT, but an optic chiasm abutting tumor, had a decline in visual function. The estimated 5-year vision and pituitary function preservation rates were 93.2% and 95.8%, respectively. Conclusions SFRT is a safe and effective treatment for patients with PMA, although longer follow-up is needed to evaluate long-term outcomes. In this study, approximately 1 patient with visual field defect out of two had an improved visual function.
Resumo:
We assessed the efficacy and the toxicity for pediatric craniopharyngioma patients of fractionated stereotactic radiotherapy (FSRT). Between May 2000 and May 2009, 9 patients (male to female ratio, 5:4) with craniopharyngiomas underwent FSRT (median dose, 54 Gy). Among the 9 patients, 6 received radiation therapy (RT) for recurrent tumors and 3 for residual disease as adjuvant therapy after incomplete surgery. Median tumor 3 volume was 2.3 cm (range, 0.1-5.8). The median target coverage was 93.7% (range 79.3-99.8%). The median conformity index was 0.94 (range, 0.6-1.4). Dose to the hippocampal region was assessed for all patients. After a median follow-up of 62.5 months (range, 32-127)the treated volume decreased in size in four of eight patients (50%). One patient was lost to follow-up. Local control and survival rates at 3 years were 100% and there were no marginal relapses. One patient, with a chronic bilateral papillary oedema after surgery, visual defect deteriorated after FSRT to a complete hemianopsia. One male patient with normal pituitary function before FSRT presented with precocious puberty at the age of 7.4 years, 24 months after FSRT. Four patients (50%) were severely obese at their last visit. FSRT is a safe treatment option for craniopharyngioma after incomplete resection.
Resumo:
Restless legs syndrome (RLS) is a common multifactorial disease. Some genetic risk factors have been identified. RLS susceptibility also has been related to iron. We therefore asked whether known iron-related genes are candidates for association with RLS and, vice versa, whether known RLS-associated loci influence iron parameters in serum. RLS/control samples (n = 954/1814 in the discovery step, 735/736 in replication 1, and 736/735 in replication 2) were tested for association with SNPs located within 4 Mb intervals surrounding each gene from a list of 111 iron-related genes using a discovery threshold of P = 5 × 10(-4). Two population cohorts (KORA F3 and F4 with together n = 3447) were tested for association of six known RLS loci with iron, ferritin, transferrin, transferrin-saturation, and soluble transferrin receptor. Results were negative. None of the candidate SNPs at the iron-related gene loci was confirmed significantly. An intronic SNP, rs2576036, of KATNAL2 at 18q21.1 was significant in the first (P = 0.00085) but not in the second replication step (joint nominal P-value = 0.044). Especially, rs1800652 (C282Y) in the HFE gene did not associate with RLS. Moreover, SNPs at the known RLS loci did not significantly affect serum iron parameters in the KORA cohorts. In conclusion, the correlation between RLS and iron parameters in serum may be weaker than assumed. Moreover, in a general power analysis, we show that genetic effects are diluted if they are transmitted via an intermediate trait to an end-phenotype. Sample size formulas are provided for small effect sizes.
Resumo:
Ancient Kinneret (Tēl Kinrōt [Hebrew]; Tell el-ʿOrēme [Arabic]) is located on a steep limestone hill on the northwestern shores of the Sea of Galilee (2508.7529 [NIG]). The site, whose settlement history began sometime during the Pottery-Neolithic or the early Chalcolithic period, is emerging as one of the major sites for the study of urban life in the Southern Levant during the Early Iron Age (c. 1130–950 BCE). Its size, accessibility by major trade routes, and strategic location between different spheres of cultural and political influence make Tēl Kinrōt an ideal place for studying the interaction of various cultures on urban sites, as well as to approach questions of ethnicity and regionalism during one of the most debated periods in the history of the ancient Levant. The paper will briefly discuss the settlement history of the site during the Early Iron Age. However, the main focus will lie on the material culture of the late Iron Age IB city that rapidly evolved to a regional center during the transition from the 11th to the 10th century BCE. During this period, ancient Kinneret features a multitude of cultural influences that reach from Egypt via the Central Hill Country until the Northern parts of Syria and the Amuq region. While there are indisputably close ties with the ‘Aramaean’ realm, there are also strong indications that there were – at the same time – vivid socio-economic links with the West, i.e. the Southern and Northern Mediterranean coasts and their hinterland. It will be argued that the resulting ‘cultural blend’ is a typical characteristic of the material culture of the Northern Jordan Rift Valley in the advent of the emerging regional powers of the Iron Age II.
Resumo:
Ancient Kinneret (Tel Kinrot [Hebrew]; Tell el-‘Orēme [Arabic]) is located on a steep limestone hill on the northwestern shores of the Sea of Galilee (map ref. 2508.7529 [NIG]; 35.56/32.87 [WGS84]). The site, whose settlement history began sometime during the Pottery-Neolithic or the early Chalcolithic period, is emerging as one of the major sites for the study of urban life in the Southern Levant during the Early Iron Age (c. 1130–950 BCE). Its size, accessibility by major trade routes, and strategic location between different spheres of cultural and political influence make Tel Kinrot an ideal place for studying the interaction of various cultures on urban sites, as well as to approach questions of ethnicity and regionalism during one of the most debated periods in the history of the ancient Southern Levant.