662 research outputs found
A Refined Calibration Procedure of Two-Channel Sun Photometers to Measure Atmospheric Precipitable Water at Various Antarctic Sites
Abstract
Two-channel sun photometers can be easily employed at Antarctic sites, where harsh environmental conditions prevail, to carry out measurements of precipitable water W. In the very dry air conditions observed in the Antarctic atmosphere, water vapor does not produce strong absorption features along the sun path. Therefore, these instruments need to be calibrated using analytical forms different from the square root regime, which can be determined by simulating the output voltages measured at Antarctic sites, for the spectral near-IR curves of extraterrestrial solar irradiance, instrumental responsivity parameters, and atmospheric transmittance, relative to various measurement periods. For this purpose, average models of the Antarctic atmosphere from the ground level up to the 30-km altitude were considered for different solar zenith angles and relative humidity conditions. The ratios between the output voltages simulated in the band and window channels were plotted as a function of total water vapor content Cw, for each site and each period, to define the best-fit calibration curves, which were subsequently normalized to the field measurements to take into account the aging effects on the filter transmission characteristics. Each of the five calibration curves was found to present a slope coefficient decreasing gradually with Cw from values higher than 0.8 to about 0.6. Using these curves, measurements of W were obtained, which differ appreciably at both sea level and high-altitude sites from those given by the square root calibration curves, avoiding large overestimation errors of 10%–40% at the high-altitude sites and underestimation errors of 5%–15% at the sea level site
Protein-disulfide isomerase- and protein thiol-dependent dehydroascorbate reduction and ascorbate accumulation in the lumen of the endoplasmic reticulum.
The transport and intraluminal reduction of dehydroascorbate was investigated in microsomal vesicles from various tissues. The highest rates of transport and intraluminal isotope accumulation (using radiolabeled compound and a rapid filtration technique) were found in hepatic microsomes. These microsomes contain the highest amount of protein-disulfide isomerase, which is known to have a dehydroascorbate reductase activity. The steady-state level of intraluminal isotope accumulation was more than 2-fold higher in hepatic microsomes prepared from spontaneously diabetic BioBreeding/Worcester rats and was very low in fetal hepatic microsomes although the initial rate of transport was not changed. In these microsomes, the amount of protein-disulfide isomerase was similar, but the availability of protein thiols was different and correlated with dehydroascorbate uptake. The increased isotope accumulation was accompanied by a higher rate of dehydroascorbate reduction and increased protein thiol oxidation in microsomes from diabetic animals. The results suggest that both the activity of protein-disulfide isomerase and the availability of protein thiols as reducing equivalents can play a crucial role in the accumulation of ascorbate in the lumen of the endoplasmic reticulum. These findings also support the fact that dehydroascorbate can act as an oxidant in the protein-disulfide isomerase-catalyzed protein disulfide formation
Pelvic lymphadenectomy for cervical carcinoma: Laparotomy extraperitoneal, transperitoneal or laparoscopic approach? A randomized study
To compare transperitoneal, extraperitoneal and laparoscopic pelvic lymphadenectomy in terms of feasibility and morbidity in patients affected by cervical cancer undergoing radical hysterectomy. Consecutive patients affected by stage IB-IIB cervical carcinoma scheduled for radical surgery entered the study. Patients were randomly assigned to transperitoneal (TPL), extraperitoneal (EPL) or laparoscopic pelvic lymphadenectomy (LPL). All patients underwent classical radical hysterectomy. Perioperative data were recorded. Follow up examinations were performed at the 15th, 30th and 60th day after surgery. 168 patients entered the study. The mean operative times were: 63+/-7.6, 54+/-6.7 and 75+/-8.4 min (TPL vs EPL P<0.001; EPL vs LPL P<0.001; TPL vs LPL P<0.001) for TPL, EPL and LPL respectively. The feasibility of the procedures, analyzed on an intention-to-treat basis, was 96%, 93% and 95% for TPL, EPL and LPL group respectively (P=ns). The average hospitalizations were: 5.6+/-0.9, 3.2+/-0.4 and 3.1+/-0.3 days (TPL vs EPL P<0.001; TPL vs LPL P<0.001) for TPL, EPL and LPL respectively. EPL and LPL are as feasible and effective as TPL and can be adequately performed with a reasonable complication rate. LPL showed a statistically significant longer operative time. However, both EPL and LPL can minimize some postoperative complications reducing length of stay
Comparison between balloon angioplasty and additional coronary stent implantation for the treatment of drug-eluting stent restenosis: 18-month clinical outcomes
OBJECTIVE: To evaluate the long-term outcomes after different modalities of treatment of drug-eluting stent (DES) in-stent restenosis (ISR) in a 'real world' setting. METHODS: Actually, few and conflicting data are available about the management of in-stent restenosis (ISR) after DES implantation. In our 'real world' registry 1082 consecutive patients who received a DES implantation were included. At 9-month angiographic follow-up, 93 patients presented a DES ISR that was treated with 'homo-DES' (HMD) (N = 27), 'hetero-DES' (HTD) (N = 19) and conventional balloon angioplasty (POBA) (N = 47). We evaluated the clinical outcomes in terms of major adverse cardiac event (MACE) (death, myocardial infarction and target vessel revascularization) at 18 months. RESULTS: There was no difference for clinical and angiographic characteristics between the three groups, except for the presence of silent ischaemia as clinical presentation (7.7 HMD vs. 2.2% POBA; P = 0.0001). No late stent thrombosis was found. At 18-month clinical follow-up patients treated with HMD, HTD and POBA presented a rate of MACE of 10.2, 0 and 8.7%, respectively (P = NS). Kaplan-Meier survival probability showed that HTD and POBA treatment tended to have more favourable outcomes at 18 months than the HMD treatment. CONCLUSION: In our registry, POBA seems to be as effective as other DES implantations in cases of DES ISR, especially in cases of focal type (Mehran classification IA, IC), in terms of long-term outcomes
Monocentric Analysis of the Effectiveness and Financial Consequences of the Use of Lenograstim Versus Filgrastim for Mobilization of Peripheral Blood Progenitor Cells in Patients With Lymphoma and Myeloma Receiving Chemotherapy and Autologous Stem Cell Transplantation
Purpose: Granulocyte-colony stimulating factors (G-CSFs) are widely used to mobilize CD34+ stem cells and to support the engraftment after hematopoietic stem cell transplantation (HSCT). A budget impact analysis and an incremental cost-effectiveness study of two G-CSFs (Lenograstim and Filgrastim biosimilar), considering engraftment, number of hospitalization days and number of G-CSF vials administered were performed. Patients and methods: Between 2009 and 2016, 248 patients undergoing autologous HSCT have been evaluated and divided into three groups (100 Leno-Leno, 93 Leno-Fil, 55 Fil-Fil) according to the type of G-CSF used for hematopoietic stem cell mobilization and hematopoietic stem cell recovery after transplant. Results: The following statistically significant differences have been observed between Leno-Leno, Leno-Fil, Fil-Fil groups: a higher number of harvested CD34+ cells (10.56 vs 8.00 vs 7.20; p=0.0003) and a lower number of G-CSF vials (8 vs 8 vs 9; p=0.00020) used for full bone marrow recovery favoring Lenograstim. No statistically significant differences were found regarding the number of G-CSF vials used for mobilization, apheresis number and CD34+ cell peak. The post-transplant hematological recovery was faster in Lenograstim group than Filgrastim group: median time to neutrophil count engraftment (>500/mmc) was 12 vs 13 days; median time for platelets recovery (>20.000/mmc) was 12 vs 15 days (p=0.0001). The use of Lenograstim achieved cost savings of \u20ac566/patient over Filgrastim biosimilar, related to a decreased number of days of hospitalization (16 vs 17 days; p=0.00012), a lower overall incidence of adverse events, laboratory tests, transfusions for platelet recovery following discharge. Conclusion: In our experience, Lenograstim outperforms Filgrastim in terms of effectiveness and lower cost. This study shows a clinical superiority of Lenograstim over Filgrastim suggesting a potential cost savings favoring Lenograstim
La trombectomia nell’angioplastica primaria
Primary percutaneous coronary intervention is the standard treatment in patients with ST-segment
elevation myocardial infarction achieving a TIMI 3 flow in more than 90% of patients. However, despite
a brisk epicardial coronary flow in the infarct-related artery, frequently post-ischemic microvascular
damage limits the efficacy of primary PCI. Recent studies suggest that thrombectomy
during primary PCI, in patients with intracoronary angiographically visible thrombus, represents a
useful adjunct to pharmacotherapy able to prevent distal embolization
Towards a definition of a real-time forecasting network for rainfall induced shallow landslides
PREVIEW is an European Commission FP6 Integrated Project with the aim of developing, at an European level, innovative geo-information services for atmospheric, geophysical and man-made risks. Within this framework, the Landslides Platform Service 2 (forecasting of shallow rapid slope movements) has developed an integrated procedure for the forecasting and warning of distributed shallow landsliding to be used for civil protection purposes. The Service consists of an automated end-to-end forecasting chain which uses data from a probabilistic downscaled short-term rainfall forecast, soil saturation estimates and meteorological radar outputs. The above data are entered into a hydro-geological model that makes use of an infinite slope approach to calculate the distributed Factor of Safety over the entire basin. All outputs, and much of the input data, are shown on a WebGIS system so that end-users can interactively access and download data. A distinctive feature of the service is the use of an innovative soil depth model for predicting the distributed thickness of the regolith cover within the basin, which is one of the most important parameters controlling shallow landslide triggering. The service was developed in a pilot test site in NE Italy, the Armea basin. Validation makes use of two rainfall events: one that occurred in 2000 and a smaller, more recent event (2006) that caused fewer landslides. Rainfall data have been used to compute a distributed factor-of-safety map that has been overlaid onto the landslide inventory. Instead of a traditional validation approach based on the number count of correctly identified landslides, we carried out an alternative procedure based on the landslides area that gave outcomes which, for this preliminary stage of the research, can be considered promising
Glucose Transport and Transporters in the Endomembranes
Glucose is a basic nutrient in most of the creatures; its transport through biological membranes is an absolute requirement of life. This role is fulfilled by glucose transporters, mediating the transport of glucose by facilitated diffusion or by secondary active transport. GLUT (glucose transporter) or SLC2A (Solute carrier 2A) families represent the main glucose transporters in mammalian cells, originally described as plasma membrane transporters. Glucose transport through intracellular membranes has not been elucidated yet; however, glucose is formed in the lumen of various organelles. The glucose-6-phosphatase system catalyzing the last common step of gluconeogenesis and glycogenolysis generates glucose within the lumen of the endoplasmic reticulum. Posttranslational processing of the oligosaccharide moiety of glycoproteins also results in intraluminal glucose formation in the endoplasmic reticulum (ER) and Golgi. Autophagic degradation of polysaccharides, glycoproteins, and glycolipids leads to glucose accumulation in lysosomes. Despite the obvious necessity, the mechanism of glucose transport and the molecular nature of mediating proteins in the endomembranes have been hardly elucidated for the last few years. However, recent studies revealed the intracellular localization and functional features of some glucose transporters; the aim of the present paper was to summarize the collected knowledge
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