Search for magnetic monopoles produced via the Schwinger mechanism.

Electrically charged particles can be created by the decay of strong enough electric fields, a phenomenon known as the Schwinger mechanism1. By electromagnetic duality, a sufficiently strong magnetic field would similarly produce magnetic monopoles, if they exist2. Magnetic monopoles are hypothetical fundamental particles that are predicted by several theories beyond the standard model3-7 but have never been experimentally detected. Searching for the existence of magnetic monopoles via the Schwinger mechanism has not yet been attempted, but it is advantageous, owing to the possibility of calculating its rate through semi-classical techniques without perturbation theory, as well as that the production of the magnetic monopoles should be enhanced by their finite size8,9 and strong coupling to photons2,10. Here we present a search for magnetic monopole production by the Schwinger mechanism in Pb-Pb heavy ion collisions at the Large Hadron Collider, producing the strongest known magnetic fields in the current Universe11. It was conducted by the MoEDAL experiment, whose trapping detectors were exposed to 0.235 per nanobarn, or approximately 1.8 × 109, of Pb-Pb collisions with 5.02-teraelectronvolt center-of-mass energy per collision in November 2018. A superconducting quantum interference device (SQUID) magnetometer scanned the trapping detectors of MoEDAL for the presence of magnetic charge, which would induce a persistent current in the SQUID. Magnetic monopoles with integer Dirac charges of 1, 2 and 3 and masses up to 75 gigaelectronvolts per speed of light squared were excluded by the analysis at the 95% confidence level. This provides a lower mass limit for finite-size magnetic monopoles from a collider search and greatly extends previous mass bounds.

Burden of rare coding variants in an Italian cohort of familial multiple sclerosis.

BACKGROUND: Multiple Sclerosis (MS) is a chronic inflammatory and neurodegenerative demyelinating disease of the central nervous system. It is a complex and heterogeneous disease caused by a combination of genetic and environmental factors, and it can cluster in families. OBJECTIVE: to evaluate at gene-level the aggregate contribution of predicted damaging low-frequency and rare variants to MS risk in multiplex families. METHODS: We performed whole exome sequencing (WES) in 28 multiplex MS families with at least 3 MS cases (81 affected and 42 unaffected relatives) and 38 unrelated healthy controls. A gene-based burden test was then performed, focusing on two sets of candidate genes: i) literature-driven selection and ii) data-driven selection. RESULTS: We identified 11 genes enriched with predicted damaging low-frequency and rare variants in MS compared to healthy individuals. Among them, UBR2 and DST were the two genes with the strongest enrichment (p = 5 × 10-4 and 3 × 10-4, respectively); interestingly enough the association signal in UBR2 is driven by rs62414610, which was present in 25% of analysed families. CONCLUSION: Despite limitations, this is one of the first studies evaluating the aggregate contribution of predicted damaging low-frequency and rare variants in MS families using WES data. A replication effort in independent cohorts is warranted to validate our findings and to evaluate the role of identified genes in MS pathogenesis.

First Search for Dyons with the Full MoEDAL Trapping Detector in 13 TeV pp Collisions.

The MoEDAL trapping detector consists of approximately 800 kg of aluminum volumes. It was exposed during run 2 of the LHC program to 6.46 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point. Evidence for dyons (particles with electric and magnetic charge) captured in the trapping detector was sought by passing the aluminum volumes comprising the detector through a superconducting quantum interference device (SQUID) magnetometer. The presence of a trapped dyon would be signaled by a persistent current induced in the SQUID magnetometer. On the basis of a Drell-Yan production model, we exclude dyons with a magnetic charge ranging up to five Dirac charges (5g_{D}) and an electric charge up to 200 times the fundamental electric charge for mass limits in the range 870-3120 GeV and also monopoles with magnetic charge up to and including 5g_{D} with mass limits in the range 870-2040 GeV.

Magnetic Monopole Search with the Full MoEDAL Trapping Detector in 13 TeV pp Collisions Interpreted in Photon-Fusion and Drell-Yan Production.

MoEDAL is designed to identify new physics in the form of stable or pseudostable highly ionizing particles produced in high-energy Large Hadron Collider (LHC) collisions. Here we update our previous search for magnetic monopoles in Run 2 using the full trapping detector with almost four times more material and almost twice more integrated luminosity. For the first time at the LHC, the data were interpreted in terms of photon-fusion monopole direct production in addition to the Drell-Yan-like mechanism. The MoEDAL trapping detector, consisting of 794 kg of aluminum samples installed in the forward and lateral regions, was exposed to 4.0 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to or above the Dirac charge are excluded in all samples. Monopole spins 0, ½, and 1 are considered and both velocity-independent and-dependent couplings are assumed. This search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.

Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC.

MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

[Clinical and instrumental surveillance of the arteriovenous fistula]. / La sorveglianza clinica e strumentale della fistola arterovenosa.

Stenosis and thrombosis are the most important complications leading to vascular access failure in hemodialysis (HD). Aiming for an early access dysfunction diagnosis and elective repair of the failing access, the DOQI guidelines recommend that all HD patients undergo a program of regular monitoring and surveillance. The K/DOQI 2000 update identifies specific types of evaluation for dialysis accesses. First nephrologists should examine patients by inspecting, ausculting and palpating the access at least every 4-6 weeks when patients are not being dialyzed. In addition, access surveillance should be regularly performed by various techniques, i.e. urea recirculation test, dialysis venous pressure measurement and access blood flow assessment. Recently many methods have been proposed and implemented. Ultrasound dilution is the most commonly used. This technique relies on the change in ultrasound velocity when blood is diluted with a normal saline bolus at a known dialyzer blood flow rate, after the lines have been reversed. Following the use of blood ultrasound dilution, multiple technologies have been implemented for access flow measurement with line reversal, i.e. hematocrit (Hct) dilution, thermodilution, conductivity variation assessment. There are three other methods that do not require line reversal: i.e. transcutaneous access flow (TQA) assessment, glucose pump test (GPT) and the variable flow Doppler. Finally, duplex scanning can provide both the anatomy and blood flow of the access. With a Qa <600 mL/min or <1000 mL/min, but reduced by 25% in 4 months, K/DOQI suggest performing angiography and eventual elective repair.

[Contrast nephropathy in cardiac procedures: no advantages with prophylactic use of N-acetylcysteine (NAC)]. / Nefropatia da contrasto in cardiologia interventistica: assenza di vantaggi con impiego profilattico di N-Acetilcisteina.

BACKGROUND: Acute renal failure induced by contrast agents represents the third cause of acute nephropathy in hospitalized patients. Some mediators are potentially involved in this process: recent data underscored the role of oxidising agents and prophylactic administration of NAC showed a lower incidence of acute renal damage after using contrast agents. METHODS: We analyzed 100 patients consecutively undergoing coronary angiography and/or transluminal angioplasty: the study group was given NAC orally at a dose of 600 mg twice daily, on the day before and on the day of administration of the contrast agent, together with hydration, while the control group was given only the hydration protocol with hypotonic saline. RESULTS: Twenty patients had baseline serum creatinine concentrations > 1.2 mg/dL (mild renal insufficiency group). The mean dose of contrast agent (Iodixanol; Visipaque 320, Nycomed) was 203 mL/procedure, with no statistical difference between groups. Among the patients with normal renal function, 5.7% in the NAC group and 8.8% in the control group had baseline serum creatinine concentrations above 0.3 mg/dL after 48 hours (p=NS). In patients with mild renal failure, 16.6% in the NAC group and 0% in the control group had serum creatinine concentrations > 0.5 mg/dL at 48 h (p=NS). We found no significant differences in serum creatinine values at 48 hours vs. baseline in anyone (NAC group with normal renal function or mild renal insufficiency, control group with normal renal function or mild renal insufficiency). Similarly, serum creatinine values at either baseline or after 48 hours were not significantly different in patients with normal renal function (NAC vs. control group) and with mild renal failure. CONCLUSIONS: Our study showed no potential advantage in the prevention of acute nephropathy, induced by high volumes of contrast agent, through the administration of NAC in patients with normal renal function and mild renal failure. However, the NAC dose used in our study might not be sufficient in balancing the contrast agent volume employed in these procedures.

[Organohalogen contamination of a dialysis-water treatment plant]. / Contaminazione da organo-alogenati di un impianto di trattamento di acqua per dialisi.

On March 2001 the regular quality control test of the water used for dialysis in an urban centre using a reverse osmosis system revealed a high level of organo-halogenated contamination. The compounds implicated were: trichloroethylene (trielene) [M.Wt. 131 D], tetrachloroethylene, trichloromethane (chloroform) [M.Wt. 121 D], chlorodibromomethane. The dialysis unit was closed. Water samples were analysed in duplicate. The table shows the values (in ppm or microgram/l) obtained for chloroform at the given times: March 8th, altered sample; March 12th, confirmation sample; March 16th, after osmosis membranes change; March 22nd, after carbon filtration replacement; March 26th, after softener resins substitution. The AAMI doesn't recommend any value for organo-halogenated compounds in dialysis water. In the past, the European Pharmacopoeia and the Italian Health Ministry released some reference values for tap water, values which were extended to water used for dialysis. The values are 1 ppm as reference value, 30 ppm as maximum accepted value for the sum of all organo-halogenated compounds, and 10 ppm as the recommended value. In conclusion, the problem was solved by progressive replacement of the components of the water treatment system, even though the real cause remained undetermined. No clinical symptom was recorded and no level of chloroform or trielene was detected in patients' sera despite the low molecular weight and low protein binding of the compounds. A strict control of the water quality and a more comprehensive and updated reference guide are needed for better and safer dialysis delivery.

[Microbiological evaluation of two different disinfection protocols of a new hemodialysis monitor with an ultrafilter]. / Valutazione microbiologica di due diversi protocolli di disinfezione di un nuovo monitor di dialisi dotato di ultrafiltro sul dialisato.

BACKGROUND: Hemodialysis monitors represent a frequent site for bacterial contamination. METHODS: Two different disinfection protocols on a new device (Formula(R), Bellco) have been compared: only chemical or chemical plus heat disinfection by means of CFU, and LAL test. The endotoxin removing capacity of ultrafilter was tested with varying lipopolysaccharide concentrations. RESULTS: Similar results were obtained with heat disinfection compared to chemical disinfection (CFU and LAL test). The LAL test (chromogenic and gel-clot) showed that the ultrafilter performance decreased with use and was significant after 200 operating hours. CONCLUSIONS: Heat disinfection between dialysis shifts and chemical disinfection at the end of the day exclude bacterial contamination of the monitor as well as chemical disinfection; LAL test is a useful and simple tool to assess the ultrafilters performance in each Center.

[Spiral x-ray computed tomography in the diagnosis of central venous catheterization complications]. / Contribution de la tomodensitométrie spiralée dans le diagnostic des complications du cathétérisme veineux central.

In this work we report our initial experience on the utilisation of the spiral tomodensitometry in the study of the vascular complications due to the catheterization of the internal jugular vein. We present the results of a systematic search of vascular lesions after removal of an indwelling catheter in a group of 18 patients and describe a few cases of acute complications where the use of TDMS has been very useful in the diagnostic workout. The results confirm the risks associated with the catheterization of the internal jugular vein, showing a frequency of lesions of various degree in about 50% of the cases. Moreover, we discuss some aspects of the thrombotic complications in the patients carrying a central venous catheter and the advantages of the diagnostic application of the spiral tomodensitometry.

Dialock(R)subcutaneous port for hemodialysis: A twelve-month experience in a single center.

Background.The arteriovenous fistula (AVF) is still considered the golden standard form of vascular access for hemodialysis. However, the increasing use of central venous catheters mirrors the growing difficulty in planning an AVF. A totally implantable new device, the Dialock(R)system (Biolink Corporation, Norwell, MA), allowed us to conduct the first Italian experience. Methods.From February 1st 2000 to January 31st 2001, we implanted 21 devices in 12 males and 9 females, median age 66+/-12 years, with a dialysis duration ranging from 0 to 22 years. In 6 cases the Dialock (R)was first choice access, in 5 it replaced a malfunctioning tunneled central venous catheter, and in 10 cases it was the rescue access after previous AVF failures. Results.On average, the device was accessed 3.5 days after implantation. Median duration of use was 142 days (range 29-365), for a global observation period of 118.2 pt-months. Nineteen devices are currently working with-out any problem. One port was removed after 60 days due to thrombosis, and another after 9 months of use due to sepsis. Another patient had a systemic infection with cardiac and vertebral involvement with complete remission after 4 months of antibiotic therapy and salvage of the device. The infection rate was 1.3 per 1000 catheter-days. Prescribed blood flow was achieved in 95.7% of the sessions. Conclusion.Our short-term results confirm the efficacy and reliability of the new device. In order to assess the true indication for implanting Dialock(R), a more prolonged observation period is needed.

Is vecuronium toxicity abolished by hemodialysis? A case report.

Vecuronium is a curaric agent, largely used in anesthesia. Indications as to its employ in uremic patients appear to be debated because of partial renal elimination of the drug. A 52-year-old hemodialyzed woman required transplantectomy for rejection. At awakeness after general anesthesia (induced with fentanyl, propofol, and 6 mg of vecuronium, repeated with a single 2 mg dose 30 min later), she presented diafragmatic and muscular limb weakeness that lasted 180 min in spite of prostigmine administration. A 2 h 30 min predilutional hemofiltration was then performed, which induced rapid disappearance of neuromuscular blockade. Even if vecuronium can be used in dialysis patients, one should remember its possible side effects, especially with repeated doses, in determining prolonged neuromuscular blockade. Cautious use of this drug in renal failure is mandatory. Low dosage must be employed and repeated administration avoided. Neuromuscular blockade seems to be rapidly reversible with dialytic treatment.

[Critical review of renal transplantation data from the Piedmontese Regional Dialysis and Transplantation Registry]. / Revisione critica dei dati riguardanti il trapianto renale nel Registro Regionale Piemontese di Dialisi e Trapianto (RPDT).

On 31/12/1995 a total of 1,128 Piedmontese uremic patients had undergone kidney transplantation, with 65% of operations performed by the Regional Reference Centre and 35% by extra-regional centres. Waiting time for dialysis was less than 5 years in over half of the patients most of whom were aged between 40 and 60 years old. In overall terms, the patient survival rate was 94%, 87%, 75% at 24, 60, 120 months respectively, with a statistically significant improvement when the curve was evaluated in the patient-pool treated with cyclosporine (84% versus 87% at 7 years). Organ survival was 76% at 21 years and 42% at 10 years, and results were again improved by the use of cyclosporine. Pathologies affecting the transplanted organ represent the main cause of morbidity; drop-out during dialysis is caused above all by immunological diseases. Infectious pathologies were responsible for the majority of deaths in this population.

[Informatics support and teledialysis]. / Supporto informatico e teledialisis.

Computer-assisted medical activity is increasing in several fields, with wide perspectives in nephrology and dialysis accounting for the peculiar characteristics of this population such as number, complexity, follow-up length and economic costs. Since 1980 we have been studying a computerized organization of our Region's departments in order to achieve 3 main results: 1) a registry of all patients undergoing dialysis in the area, with a one- a-year complete clinical update; 2) a computerized medical chart, which could gather all the clinical, technical and managerial aspects of the treatment; 3) a teledialysis program, to follow every session in local and remote stations. The first aim has been reached with useful information for the dialytic policy in the area. The second objective is ongoing with straight evidence of easy, speedy procedures, and accurate data collection. The third goal is on a preliminary phase looking at the safety, reliability and precision of the treatments. Informatic procedures seem to be quite advisable in improving as clinical surveillance of the patients, as technical and managerial aspects of dialysis units.

Prospective study on captopril renography in hypertensive patients.

Six hundred and sixty-seven hypertensive patients were analyzed by captopril-enhanced scintigraphy. If time to reach maximal activity (Tmax) was > or = 5 min using 99mTc-diethylenetriaminepentaacetic acid (DTPA) or > or = 3 min with 123I-o-iodohippurate (OIH) and 99mTc-mercaptoacetyltriglycine (MAG3) and washout time > or = 15 min, a control study with nifedipine was performed. If the difference between Tmax under captopril and nifedipine premedication was > or = 5 min with 99mTc-DTPA or > or = 3 min with 123I-OIH and 99mTc-MAG3, the renogram was defined highly suggestive of renovascular hypertension. In the evaluation of bilateral abnormalities an additional parameter was considered, i.e. the presence of functional asymmetry of the emuntories susceptible of partial reversal in the control study under nifedipine. Based on these criteria, 58 out of 667 (8.7%) scintigrams were found to be abnormal. Thirty-five of these 58 patients and 32 of the remaining 609 scintigraphically negative cases underwent additional arteriographic examination. A renal vascular stenosis > or = 50% was found in 33 out of 35 (94.2%) patients with positive scintigraphy and in 3 out of 32 patients with negative scintigraphy. By examining results of the 67 patients undergoing arteriography, the sensitivity of captopril-enhanced scintigraphy was estimated to be 91.6%, with a specificity of 93.5%, an accuracy of 92.5%, and predictive values of a positive or negative result of 94.2 and 90.6%, respectively. By restricting analysis to bilateral stenosis, sensitivity was found to be 76.9%.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the influence of peritoneal dialysis on cellular immunity by the E-rosette inhibition test.

Sera of patients on peritoneal dialysis and regular hemodialysis were analyzed over a follow-up period of 8 months for the capacity of normal lymphocytes to inhibit E-rosette formation. The percentage of inhibition in sera from peritoneal dialysis patients was significantly reduced (p less than 0.02) only 1 month after treatment was started, whereas in hemodialysis patients the percentage of inhibition remained unchanged. No difference was observed between sera collected before and after the hemodialysis sessions. There was no significant positive correlation between the percentage of E-rosette inhibition and p-urea, p-creatinine, s-albumin, and s-proteins, respectively. Statistical analysis of the E-rosette inhibition test by uremic serum and spontaneous E-rosettes in these patients showed a significant regression coefficient (p less than 0.01) in both groups. The fact that, unlike ultrafiltrate from hemodialysis, peritoneal dialysate significantly (p less than 0.05) inhibits the E-rosette formation capacity of normal lymphocytes, confirms these findings, suggesting an inhibitory activity of serum factors on lymphocyte function.

Lymphocyte subsets assayed by numerical tests in CAPD.

Peripheral and peritoneal lymphocytes were assayed by numerical tests in adults on peritoneal dialysis. T lymphocytes were classified by monoclonal antibodies (OKT3, OKT4, OKT8) and B lymphocytes by the presence of surface immunoglobulins, using the immunofluorescence technique. Peripheral T cells showed no significant change from the normal, except for T suppressor cells which increased in patients with 2 or more peritonitis episodes. Examination of peritoneal lymphocytes showed a significant reduction in S-IgA lymphocytes (B cells bearing IgA receptors) and an increase in T-suppressor cells (OKT8+) in patients who developed peritonitis in the follow-up study. The implications of these results are discussed with particular reference to susceptibility to peritonitis.