A new cylindrical borehole detector for radiographic imaging with muons.

Muon radiography is a methodology which enables measuring the mass distribution within large objects. It exploits the abundant flux of cosmic muons and uses detectors with different technologies depending on the application. As the sensitive surface and geometric acceptance are two fundamental parameters for increasing the collection of muons, the optimization of the detectors is very significant. Here we show a potentially innovative detector of size and shape suitable to be inserted inside a borehole, that optimizes the sensitive area and maximizes the angular acceptance thanks to its cylindrical geometry obtained using plastic arc-shaped scintillators. Good spatial resolution is obtained with a reasonable number of channels. The dimensions of the detector make it ideal for use in 25 cm diameter wells. Detailed simulations based on Monte Carlo methods show great cavity detection capability. The detector has been tested in the laboratory, achieving overall excellent performance.

Applications of muon absorption radiography to the fields of archaeology and civil engineering.

Muon radiography, also known as muography, is an imaging technique that provides information on the mass density distribution inside large objects. Muons are naturally produced in the interactions of cosmic rays in the Earth's atmosphere. The physical process exploited by muography is the attenuation of the muon flux, that depends on the thickness and density of matter that muons cross in the course of their trajectory. A particle detector with tracking capability allows the measurement of the muons flux as a function of the muon direction. The comparison of the measured muon flux with the expected one gives information on the distribution of the density of matter, in particular, on the presence of cavities. In this article, the measurement performed at Mt. Echia in Naples (Saracino 2017 Sci. Rep. 7, 1181. (doi:10.1038/s41598-017-01277-3)), will be discussed as a practical example of the possible application of muography in archaeology and civil engineering.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

Tests of a novel imaging algorithm to localize hidden objects or cavities with muon radiography.

A novel algorithm developed within muon radiography to localize objects or cavities hidden inside large material volumes was recently proposed by some of the authors (Bonechi et al. 2015 J. Instrum. 10, P02003 (doi:10.1088/1748-0221/10/02/P02003)). The algorithm, based on muon back projection, helps to estimate the three-dimensional position and the transverse extension of detected objects without the need for measurements from different points of view, which would be required to make a triangulation. This algorithm can now be tested owing to the availability of real data collected both in laboratory tests and from real-world measurements. The methodology and some test results are presented in this paper.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

Volcanoes in Italy and the role of muon radiography.

Cosmic-ray muon radiography (muography), an imaging technique that can provide measurements of rock densities within the top few 100 m of a volcanic cone, has now achieved a spatial resolution of the order of 10 m in optimal detection conditions. Muography provides images of the top region of a volcano edifice with a resolution that is considerably better than that typically achieved with other conventional methods (i.e. gravimetric). We expect such precise measurements, to provide us with information on anomalies in the rock density distribution, which can be affected by dense lava conduits, low-density magma supply paths or the compression with the depth of the overlying soil. The MUon RAdiography of VESuvius (MURAVES) project is now in its final phase of construction and deployment. Up to four muon hodoscopes, each with a surface of roughly 1 m2, will be installed on the slope of Vesuvius and take data for at least 12 months. We will use the muographic profiles, combined with data from gravimetric and seismic measurement campaigns, to determine the stratigraphy of the lava plug at the bottom of the Vesuvius crater, in order to infer potential eruption pathways. While the MURAVES project unfolds, others are using emulsion detectors on Stromboli to study the lava conduits at the top of the volcano. These measurements are ongoing: they have completed two measurement campaigns and are now performing the first data analysis.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

Imaging of underground cavities with cosmic-ray muons from observations at Mt. Echia (Naples).

Muography is an imaging technique based on the measurement of absorption profiles for muons as they pass through rocks and earth. Muons are produced in the interactions of high-energy cosmic rays in the Earth's atmosphere. The technique is conceptually similar to usual X-ray radiography, but with extended capabilities of investigating over much larger thicknesses of matter thanks to the penetrating power of high-energy muons. Over the centuries a complex system of cavities has been excavated in the yellow tuff of Mt. Echia, the site of the earliest settlement of the city of Naples in the 8th century BC. A new generation muon detector designed by us, was installed under a total rock overburden of about 40 metres. A 26 days pilot run provided about 14 millions of muon events. A comparison of the measured and expected muon fluxes improved the knowledge of the average rock density. The observation of known cavities proved the validity of the muographic technique. Hints on the existence of a so far unknown cavity was obtained. The success of the investigation reported here demonstrates the substantial progress of muography in underground imaging and is likely to open new avenues for its widespread utilisation.

Modification of the Bu/Cy myeloablative regimen using daily parenteral busulfan: reduced toxicity without the need for pharmacokinetic monitoring.

Pharmacokinetic and clinical outcome measures among three groups of patients undergoing hematopoietic transplant were assessed: group A: Parenteral busulfan (Bu) 3.2 mg/kg i.v. given qd, n=20; group B: parenteral Bu 0.8 mg/kg i.v. given every 6 h, n=11; group C: Bu 1 mg/kg p.o. given every 6 h, n=25. All groups received Bu over 4 days followed by Cy 60 mg/kg i.v. qd over 2 days; followed by an infusion of allogeneic stem cells. Median Bu clearance was 3.21 ml/min/kg and median daily AUC was 4071 micromol/min for the group A patients. The dosing formula for Bu i.v. qd was highly predictive of the AUC for patients whose mass < or =IBW+20%. For patients of greater mass, the dosing formula uniformly resulted in lower-than-predicted AUC. Neurologic toxicity, hepatic toxicity, hematologic engraftment, and relapse at 100 days were comparable across all three groups. Severe AGVHD was least among group A, followed by group B when compared with group C. Bu i.v. qd is a safe and effective regimen for allogeneic transplantation and is at least clinically equivalent to every 6 h dosing schemes using either oral or parenteral Bu.

Sirolimus conversion after liver transplantation: improvement in measured glomerular filtration rate after 2 years.

METHODS: We reviewed our prospectively maintained database of 2005 liver transplantations. Therapy was either started de novo or converted from calcineurin inhibitors (CNIs) to sirolimus as the main immunosuppressive agent for nephrotoxicity or rejection. Glomerular filtration rate (GFR) was determined with iodine 125-labeled sodium isthalamate (Glofil-125), and serum creatinine concentration was obtained before and 3 months after transplantation, and yearly in both groups. Sirolimus levels were 10 to 15 ng/mL in patients at less than 3 months after transplantations and 5 to 10 ng/mL in the remaining patients. All patients received mycophenolate mofetil as maintenance therapy. RESULTS: Data for 29 patients in the de novo group and 35 in the conversion group were reviewed. Patients in the de novo group demonstrated an acute cellular rejection rate of 17.2%, 40% of which were steroid resistant. In this group, 48.2% discontinuation of sirolimus was necessary because of adverse effects. Patients in the conversion group demonstrated an acute cellular rejection rate of 2.8% and a 34.3% rate of sirolimus discontinuation. Seventeen (56.7%) patients at 1 year and 8 (44.4%) patients at 2 years demonstrated continued improvement in GFR. In the conversion group, case-control analysis did not demonstrate a significant difference in GFR and serum creatinine concentration (P > .05) at 1 and 2 years after conversion. At the time of review, no patients in the conversion group required hemodialysis. CONCLUSIONS: Conversion to sirolimus therapy is an effective strategy in improving renal function in patients with CNI-induced nephrotoxicity and can be done without increased rejection. Most of our patients (65.7%) tolerated sirolimus conversion. Of these, 56.7% and 44.4% demonstrated continued increase in GFR with the CNI-free regimen at 1 and 2 years, respectively. Long-term, large-population, prospective, randomized, controlled studies should further validate these results.

Endovascular treatment of a postlaminectomy arteriovenous fistula. A case report.

We report a case of iliac arteriovenous fistula (AVF) following disk surgery. A 51-year-old woman underwent hemilaminectomy for a slipped disk. Two weeks after surgery the patient experienced dyspnea and oedema of the lower limbs. Presence of a systolic murmur on the cardiac floor and on the abdomen was detected and abdomen CT scan which evidenced a AVF between the right common iliac artery and vein. The lesion, confirmed by angiography, was successfully treated with the endovascular technique. The endovascular technique appears to be a valid alternative to the traditional surgical treatment of postlaminectomy AVF.

Changes in left ventricular size during parabolic flights by two-dimensional echocardiography and level set method.

This study aims to evaluate changes on cardiac chambers size, induced by gravitational stresses. During parabolic flight, seven subjects underwent 2-D transthoracic echocardiography at three different gravity phases (1 Gz, 1.8 Gz, and 0 Gz). LV endocardial borders were detected applying a semi-automatic segmentation procedure based on level set methods. LV cavity area was computed frame-by-frame for a whole cardiac cycle during each gravity phase. Expected modifications in LV area with different gravity were found: at 1.8 Gz, end-diastolic (ED) and end-systolic (ES) areas were significantly (p<0.05) reduced of 10.7 +/- 5.4% and 21.6 +/- 11.1% respectively, compared to 1 Gz values, while they were increased of 11.2 +/- 5.4% and 11.1 +/- 6% during 0 Gz. Fractional area change was augmented of 20.9 +/- 29.1% at 1.8 Gz, while it remained unchanged at 0 Gz, compared with 1 Gz values. Furthermore, LV filling due to atrial contraction was increased at 0 Gz of 39 +/- 35.6%.

Fast interactive real-time volume rendering of real-time three-dimensional echocardiography: an implementation for low-end computers.

Real-time three-dimensional echocardiography (RT3DE) is an innovative cardiac imaging modality. However, partly due to lack of user-friendly software, RT3DE has not been widely accepted as a clinical tool. The object of this study was to develop and implement a fast and interactive volume renderer of RT3DE datasets designed for a clinical environment where speed and simplicity are not secondary to accuracy. Thirty-six patients (20 regurgitation, 8 normal, 8 cardiomyopathy) were imaged using RT3DE. Using our newly developed software, all 3D data sets were rendered in real-time throughout the cardiac cycle and assessment of cardiac function and pathology was performed for each case. The real-time interactive volume visualization system is user friendly and instantly provides consistent and reliable 3D images without expensive workstations or dedicated hardware. We believe that this novel tool can be used clinically for dynamic visualization of cardiac anatomy.

A semi-automatic method for left ventricle volume estimate: an in vivo validation study.

This study aims to the validation of the left ventricular (LV) volume estimates obtained by processing volumetric data utilizing a segmentation model based on level set technique. The validation has been performed by comparing real-time volumetric echo data (RT3DE) and magnetic resonance (MRI) data. A validation protocol has been defined. The validation protocol was applied to twenty-four estimates (range 61-467 ml) obtained from normal and pathologic subjects, which underwent both RT3DE and MRI. A statistical analysis was performed on each estimate and on clinical parameters as stroke volume (SV) and ejection fraction (EF). Assuming MRI estimates (x) as a reference, an excellent correlation was found with volume measured by utilizing the segmentation procedure (y) (y=0.89x + 13.78, r=0.98). The mean error on SV was 8 ml and the mean error on EF was 2%. This study demonstrated that the segmentation technique is reliably applicable on human hearts in clinical practice.

A plausible mechanism of electron transfer between quinones in photosynthetic reaction centers.

The mechanism of long-range electron transfer between the primary and the secondary quinone of photosynthetic reaction centers has been investigated, with particular attention on the role of the iron-histidine bridge. Computations suggest that in such a system, where the molecular subunits are packed together by H-bonds, a mobile electron, injected on one end of the chain, can be carried to the other end by switching the positions of the H-bonded hydrogens. Energy estimates would suggest that the proposed mechanism is plausible and worthy of further experimental investigations.

[Role of echography in the diagnosis of urethral stenosis]. / Ruolo dell'ecografia nella diagnostica delle stenosi dell'uretra.

A recently developed ultrasonographic technique was described to evaluate the anterior urethra in 10 men suspected to have urethral stenoses. With the patient in frog leg position, during a perfusion of the urethra with saline through a catheter positioned at the beginning of the urethra, penile, transscrotal and transperineal scanning of the urethra was obtained. In all patients a diagnosis of urethral stenoses was made. After sonographic evaluation all patient underwent retrograde urethrogram and internal urethrotomy, that confirmed the diagnosis made by ultrasound. The urethral ultrasound provides valuable informations about the number, extent, position of the strictures and eventual scarring of the periurethral tissue. Urethral ultrasonography can be used as alternative imaging modality to the conventional radiological techniques.

[Echo-guided percutaneous treatment of renal cysts: aspiration vs continuous 24-hour drainage]. / Trattamento percutaneo ecoguidato delle cisti renali: aspirazione vs drenaggio continuo di 24 ore.

The results of 2 treatment options, percutaneous aspiration vs percutaneous aspiration and continuous drainage over 24 hours, in the management of simple renal cyst were compared. Thirteen patients were managed with aspiration alone (group 1) while 19 with aspiration and continuous drainage (group 2). Recurrence rate was 100% in group 1 and 73% in group 2 (p: n.s.). Therefore, we believe that the higher cost of continuous drainage are not justified.

[Renal peripelvic multicystic lymphangiectasia: is echographic diagnosis possible?]. / La linfangiectasia multicistica peripielica renale (LMPR): è possibile una diagnosi ecografica?

We describe the role of US, in the diagnosis of LMPR and in differentiating LMPR from other renal disease, such as hydronephrosis and parapelvic cysts. In 10 patients mild to moderate hydronephrosis showed at the US, bilateral in 8 cases, was not confirmed at IVP and CT scan evaluation. Instead, compression of the collecting system by multiple cysts arising from the renal sinus was revealed by CT scan in 8 cases and by IVP in 2. At the U.S. the profile of the calices appeared irregular, differing from the features of hydronephrosis; furthermore calices were adjacent each other, separated only by a thin membrane. All patients were asymptomatic. The examination of the cystic liquor and wall, obtained percutaneously or during surgical procedures, showed the lymphatic origin of them. We cannot provide definitive data regarding how to differentiate LMPR from hydronephrosis at U.S.. In asymptomatic patients the U.S. evidence of dilated calices with irregular profile and thin membrane separating each other, can strongly suggest the diagnosis of LMPR.

Flow cytometric analysis and motility response to laminin and fibronectin of four new metastatic variants of the human renal cell carcinoma line RC43.

Using subrenal capsule implantation (SRC) in nude mice we have isolated 4 new sublines (RC43MSP, MBO, MLI, MDI) from the human renal cell carcinoma line (HRCC) RC43. These sublines exhibit an enhanced metastatic ability and a faster doubling time after subcutaneous (SC) transplantation in vivo, when compared to the parental line. With the aim of a better characterization of these new sublines we have performed a flow cytometric analysis (FA) of the DNA content and studied the motility response (MR) to laminin and fibronectin. FA results. The RC43 parental line showed a tetraploid pattern (DNA index: 2.08). Also the variant lines RC43MLI and RC43MDI were tetraploid (DNAind: 2.05 and 2.07, respectively). With RC43MDI a second peak in the tetraploid range was evident. The RC43MSP and the RC43MBO sublines both showed a hypertetraploid pattern (DNAind respectively 2.21 and 2.11). MR results. Motility studies showed that all RC43 lines, including the parental line, were stimulated to migrate in response to either laminin or fibronectin both from rat and human sources. There were no significant differences between the parental line and its variants in this respect, however. We conclude that by the use of FA at least two of the sublines (MSP and MBO) can be distinguished from the parental RC43 cell line, suggesting a different clonal origin of the various sublines. As all sublines, as well as the parental line, showed a large but similar response to migration-stimulating agents (such as laminin and fibronectin) determination of MR could not be used to obtain a further discrimination between the different sublines.

Prediction of recurrence and progression in primary superficial bladder cancer with DNA flow cytometry.

Intravesical chemotherapy has been well established as an effective therapy for recurrent superficial bladder tumors. We investigated the role of flow cytometry as a predictor of tumor recurrence/progression after intravesical chemotherapy. Flow cytometric analysis of nuclear DNA ploidy pattern was performed on 'cold cup' biopsy samples of 52 patients with primary superficial bladder cancer. Cell suspensions, retrieved after mechanical fragmentation, were stained with propidium iodide and examined on FACScan flow cytometer. Clinical follow-up ranged from 3 to 57 months with a median of 20 months. Of the 52 patients, 24 aneuploid and 28 diploid tumors were observed. The degree of ploidy in relation to histological grade showed an increasing frequency of aneuploid pattern in grades 2 and 3 but with no statistical significance. 17.8% of diploid tumors versus 54.1% of aneuploid tumors recurred (p less than 0.05). 12.5% of the aneuploid tumors progressed. No progression among diploid tumors was observed. Of the 52 patients examined, 35 (16 aneuploid and 19 diploid) were treated, after TUR, with intravesical prophylactic therapy. Epirubicin in 24, mitomycin C in 4 and recombinant interferon alpha 2a in 7 were used. 50% of aneuploid tumors versus 10.5% of diploid tumors recurred (p less than 0.05). Strong predictors of response to intravesical prophylaxis of recurrence were G1 grade and diploid DNA content.