777 research outputs found
Effects of unloading and positive inotropic interventions on left ventricular function in asymptomatic patients with chronic severe aortic insufficiency.
The effect of an unloading (nifedipine, 20 mg sublingually) and of a combined unloading and positive inotropic intervention (nifedipine plus digoxin, 0.5 mg intravenously) on left ventricular performance was assessed in 48 patients with chronic severe aortic insufficiency. The left ventricular pump function-myocardial contractility relation (ejection fraction, EF vs. peak arterial pressure to end-systolic volume ratio, PAP/ESV), and the pump function-afterload relation (EF vs. mean systolic wall stress, MWS) were constructed by means of quantitative M-mode and two-dimensional echocardiography. In patients with normal control pump function (n = 14), nifedipine markedly decreased MWS, moving the patients to a new, more advantageous EF-MWS relation. In the 34 patients with abnormal pump function, the myocardial contractility level was the mean factor conditioning the response to pharmacological intervention. Patients with a value of PAP/ESV greater than 2.5 (n = 22) had normalization of EF after nifedipine and were upgraded to a more advantageous outlook for left ventricular mechanics EF-MWS and EF-PAP/ESV relations. Of the 12 patients without normalization of EF after nifedipine, only the 4 patients with PAP/ESV greater than 2 had normalization of pump function indices after combined administration of nifedipine and digoxin
Near real time regional moment tensor estimation using italian broadband stations
Since 2002, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) in Rome has started the installation of a high quality
regional broadband network throughout the Italian territory. Up today, the network consists of 125 stations equipped with 40 s
natural period instruments. The dense station coverage allows for the implementation of real-time regional moment tensor (MT)
estimation procedures such as that proposed by Dreger and Helmberger (1993).
The automatic MT algorithm uses real-time broadband waveforms continuously telemetered to INGV, and it is triggered for events
with magnitude greater than Ml 3.5. This is the lowermost value for which we have found it possible to obtain reliable MT determination
in the frequency band used in the inversion. The automatic solution is available within about 3-5 minutes after the earthquake
location. Each solution has an assigned quality factor dependent on the number of the station used in the inversion, and the godness
of fit between synthetic and observed data. MT is published on the web after revision by a seismologist.
Efforts are also made to evaluate MT solutions for earthquakes occurring in Italy and neighboring regions in the last years. The
results are compared to those obtained from application of other moment tensor methods. It is always found a good agreement
between the newly determined solutions and those from other methods.
Overall, fast and accurate moment tensor solutions are an important ingredient when attempting to estimate the recorded ground
shaking. Overall, in Italy, earthquakes in the magnitude range 3.5 – 5 are very common; the availability of their focal mechanisms
allows the mapping of the principal stress field axes leading to a better understanding of the ongoing tectonics
PHK from phenol hydroxylase of Pseudomonas sp. OX1. Insight into the role of an accessory protein in bacterial multicomponent monooxygenases
Bacterial multicomponent monooxygenases (BMMs) are members of a wide family of diiron enzymes that use molecular oxygen to hydroxylate a variety of aromatic compounds. The presence of genes encoding for accessory proteins not involved in catalysis and whose role is still elusive, is a common feature of the gene clusters of several BMMs, including phenol hydroxylases and several soluble methane monooxygenases. In this study we have expressed, purified, and partially characterized the accessory component PHK of the phenol hydroxylase from Pseudomonas sp. OX1, a bacterium able to degrade several aromatic compounds. The phenol hydroxylase (ph) gene cluster was expressed in Escherichia coli/JM109 cells in the absence and in the presence of the phk gene. The presence of the phk gene lead to an increase in the hydroxylase activity of whole recombinant cells with phenol. PHK was assessed for its ability to interact with the active hydroxylase complex. Our results show that PHK is neither involved in the catalytic activity of the phenol hydroxylase complex nor required for the assembly of apo-hydroxylase. Our results suggest instead that this component may be responsible for enhancing iron incorporation into the active site of the apo-hydroxylase
Centroid moment tensor catalog with 3D lithospheric wavespeed model. The 2016–2017 Central Apennines sequence
Moment tensor inversions of broadband velocity data are usually managed by adopting Green's
functions for 1D layered seismic wave speed models. This assumption can impact on source parameter
estimates in regions with complex 3D heterogeneous structures and discontinuities in rock properties. In
this work, we present a new centroid moment tensor (CMT) catalog for the Amatrice-Visso-Norcia (AVN)
seismic sequence based on a recently generated 3D wave speed model for the Italian lithosphere. Forward
synthetic seismograms and Fréchet derivatives for CMT-3D inversions of 159 earthquakes with Mw ≥ 3.0 are
simulated using a spectral-element method (SEM) code. By comparing the retrieved solutions with those from
time domain moment tensor (TDMT) catalog, obtained with a 1D wave speed model calibrated for Central
Apennines (Italy), we observe a remarkable degree of consistency in terms of source geometry, kinematics,
and magnitude. Significant differences are found in centroid depths, which are more accurately estimated using
the 3D model. Finally, we present a newly designed parameter, Ï„, to better quantify and compare a-posteriori
the reliability of the obtained MT solutions. Ï„ measures the goodness of fit between observed and synthetic
seismograms accounting for differences in amplitude, arrival time, percentage of fitted seconds, and the usual
L2-norm estimate. The CMT-3D solutions represent the first Italian CMT catalog based on a full-waveform
3D wave speed model. They provide reliable source parameters with potential implications for the structures
activated during the sequence. The developed approach can be readily applied to more complex Italian regions
where 1D models are underperforming and not representative of the area
Weight Loss in Advanced Chronic Kidney Disease: Should We Consider Individualised, Qualitative, ad Libitum Diets? A Narrative Review and Case Study.
In advanced chronic kidney disease, obesity may bring a survival advantage, but many transplant centres demand weight loss before wait-listing for kidney graft. The case here described regards a 71-year-old man, with obesity-related glomerulopathy; referral data were: weight 110 kg, Body Mass Index (BMI) 37 kg/m2, serum creatinine (sCr) 5 mg/dL, estimated glomerular filtration rate (eGFR) 23 mL/min, blood urea nitrogen (BUN) 75 mg/dL, proteinuria 2.3 g/day. A moderately restricted, low-protein diet allowed reduction in BUN (45–55 mg/dL) and good metabolic and kidney function stability, with a weight increase of 6 kg. Therefore, he asked to be enrolled in a weight-loss program to be wait-listed (the two nearest transplant centres required a BMI below 30 or 35 kg/m2). Since previous low-calorie diets were not successful and he was against a surgical approach, we chose a qualitative, ad libitum coach-assisted diet, freely available in our unit. In the first phase, the diet is dissociated; he lost 16 kg in 2 months, without need for dialysis. In the second maintenance phase, in which foods are progressively combined, he lost 4 kg in 5 months, allowing wait-listing. Dialysis started one year later, and was followed by weight gain of about 5 kg. He resumed the maintenance diet, and his current body weight, 35 months after the start of the diet, is 94 kg, with a BMI of 31.7 kg/m2, without clinical or biochemical signs of malnutrition. This case suggests that our patients can benefit from the same options available to non-CKD (chronic kidney disease) individuals, provided that strict multidisciplinary surveillance is assured
Results of patch-grafting of tissue infected by ‘Candidatus Phytoplasma pyri’ or by ‘Candidatus Phytoplasma prunorum’, respectively on pear and apricot plants cultivated in pot
Molecular analyses carried out either on the pear varieties ‘Conference’, ‘Comice’ and ‘William’ grafted on different rootstocks or on sixty-eight apricot varieties grafted on Myrobalan, showed the susceptibility of the tested combinations to 'Candidatus Phytoplasma pyri', transmitted by Cacopsylla pyri, and to 'Candidatus Phytoplasma prunorum', transmitted by Empoasca decedens, respectively. In order to find pear and/or apricot combinations immune to the associated Phytoplasma, several varieties grafted on new rootstock were tested in the period 2002-2008. 68 pear plants belonging to seven variety/rootstock combinations and 76 apricot plants belonging to seven combinations, all cultivated in pot, in greenhouse covered by anti-aphid tissue, were grafted with patches of infected tissues containing the specific phytoplasmas. Young healthy potted plants belonging to the pear combination ‘Comice’/P. communis and to the apricot combination ‘Palummella’/Myrobalan, both susceptible in open field to the associated phytoplasmas transmitted by the specific vectors, were also used and patch-grafted. Molecular analyses, carried out on nucleic acids extracted from leaf samples, to detect the presence of the pathogens, showed the pear variety ‘William’ grafted on Pyrus betulaefolia to be susceptible to 'Candidatus Phytoplasma pyri’. Neither the pear combination ‘Comice’/P. communis nor the apricot ‘Palummella’/Myrobalan 29 C, susceptible, in open field, to the associated phytoplasmas, became infected after patchgrafting under greenhouse conditions. Thus the results show that patch-grafting cannot be utilized in young potted plants for artificial transmission of these two phytoplasmas.Keywords: Phytoplasmas, source of immunity, variety/rootstock combination, molecular tests, insect proof green-hous
Erosion of Empathy in Primary Care Trainees
Objective:
To evaluate if empathy among physician residents (trainees) differs dependent on training year and to assess trainees\u27 characteristics associated with higher empathy scores.
Poster presented at 2016 ISPOR conference in Washington DC.https://jdc.jefferson.edu/jcphposters/1006/thumbnail.jp
Evaluation of corneal distortion characteristics in different eyes using Scheimpflug camera device
Objective. To study the correlations between corneal distortion and morphological features in different kinds of eyes such as healthy ones (HE), ones previously undergone myopic PRK (PRKE), ones affected by keratoconus (KCE) and keratoconus eyes previously undergone corneal collagen crosslinking (CCCE). Materials and Methods. In this retrospective comparative study, a total of 106 HE of 106 patients, 58 PRKE of 58 patients, 33 KCE of 33 patients, 28 CCCE of 28 patients were included. A complete examination of all eyes was followed by tomographic (Pentacam, Oculus, Wetzlar, Germany) and biomechanical (Corvis ST, Oculus, Wetzlar, Germany) evaluation. Differences among Corvis ST (CST) parameters in the different groups have been analyzed. Linear regressions between central corneal thickness (CCT), intraocular pressure (IOP) and anterior corneal curvature measured with Simulated Keratometry (SK), versus corneal deformation parameters measured with Corvis ST in the different groups, have been run using SPSS software version 18.0. Results, HE showed a significant correlation between main curvature power of the cornea within the central 3 mm expressed in Diopters (KM) and 6 CST parameters; between CCT and 4 CST parameters and between IOP and 5 CST parameters. PRKE showed a significant correlation between KM and 3 CST parameters; between IOP and 4 CST parameters and none between CCT and CST parameters. KCE showed a significant correlation between SK and 3 CST parameters; between IOP and 3 CST parameters and none between CCT and CST parameters. CCCE showed a significant correlation between KM and 5 CST parameters; between CCT and 1 CST parameters and between IOP and 5 CST parameters. Discussion. Data of this study suggest that both corneal curvature and IOP could have a greater influence on the corneal deformation, compared to central corneal thickness (CCT). These results should be taken into account by further studies aiming to assess biomechanical corneal characteristics
Regional Body-Wave Attenuation Using a Coda Source Normalization Method: Application to MEDNET Records of Earthquakes in Italy
We develop a new methodology to determine apparent attenuation for the regional seismic phases Pn, Pg, Sn, and Lg using coda-derived source spectra. The local-to-regional coda methodology (Mayeda, 1993; Mayeda and Walter, 1996; Mayeda et al., 2003) is a very stable way to obtain source spectra from sparse networks using as few as one station, even if direct waves are clipped. We develop a two-step process to isolate the frequency-dependent Q. First, we correct the observed direct wave amplitudes for an assumed geometrical spreading. Next, an apparent Q, combining path and site attenuation, is determined from the difference between the spreading-corrected amplitude and the independently determined source spectra derived from the coda methodology. We apply the technique to 50 earthquakes with magnitudes greater than 4.0 in central Italy as recorded by MEDNET broadband stations around the Mediterranean at local-to-regional distances. This is an ideal test region due to its high attenuation, complex propagation, and availability of many moderate sized earthquakes. We find that a power law attenuation of the form Q(f) = Q{sub 0}f{sup Y} fit all the phases quite well over the 0.5 to 8 Hz band. At most stations, the measured apparent Q values are quite repeatable from event to event. Finding the attenuation function in this manner guarantees a close match between inferred source spectra from direct waves and coda techniques. This is important if coda and direct wave amplitudes are to produce consistent seismic results
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