Search for Daily Modulation of MeV Dark Matter Signals with DAMIC-M.

Dark matter (DM) particles with sufficiently large cross sections may scatter as they travel through Earth's bulk. The corresponding changes in the DM flux give rise to a characteristic daily modulation signal in detectors sensitive to DM-electron interactions. Here, we report results obtained from the first underground operation of the DAMIC-M prototype detector searching for such a signal from DM with MeV-scale mass. A model-independent analysis finds no modulation in the rate of 1 e^{-} events with sidereal period, where a DM signal would appear. We then use these data to place exclusion limits on DM in the mass range [0.53,2.7] MeV/c^{2} interacting with electrons via a dark photon mediator. Taking advantage of the time-dependent signal we improve by ∼2 orders of magnitude on our previous limit obtained from the total rate of 1 e^{-} events, using the same dataset. This daily modulation search represents the current strongest limit on DM-electron scattering via ultralight mediators for DM masses around 1 MeV/c^{2}.

First Constraints from DAMIC-M on Sub-GeV Dark-Matter Particles Interacting with Electrons.

We report constraints on sub-GeV dark matter particles interacting with electrons from the first underground operation of DAMIC-M detectors. The search is performed with an integrated exposure of 85.23 g days, and exploits the subelectron charge resolution and low level of dark current of DAMIC-M charge-coupled devices (CCDs). Dark-matter-induced ionization signals above the detector dark current are searched for in CCD pixels with charge up to 7e^{-}. With this dataset we place limits on dark matter particles of mass between 0.53 and 1000 MeV/c^{2}, excluding unexplored regions of parameter space in the mass ranges [1.6,1000] MeV/c^{2} and [1.5,15.1] MeV/c^{2} for ultralight and heavy mediator interactions, respectively.

Results on Low-Mass Weakly Interacting Massive Particles from an 11 kg d Target Exposure of DAMIC at SNOLAB.

We present constraints on the existence of weakly interacting massive particles (WIMPs) from an 11 kg d target exposure of the DAMIC experiment at the SNOLAB underground laboratory. The observed energy spectrum and spatial distribution of ionization events with electron-equivalent energies >200 eV_{ee} in the DAMIC CCDs are consistent with backgrounds from natural radioactivity. An excess of ionization events is observed above the analysis threshold of 50 eV_{ee}. While the origin of this low-energy excess requires further investigation, our data exclude spin-independent WIMP-nucleon scattering cross sections σ_{χ-n} as low as 3×10^{-41} cm^{2} for WIMPs with masses m_{χ} from 7 to 10 GeV c^{-2}. These results are the strongest constraints from a silicon target on the existence of WIMPs with m_{χ}<9 GeV c^{-2} and are directly relevant to any dark matter interpretation of the excess of nuclear-recoil events observed by the CDMS silicon experiment in 2013.

Value of cardiac MRI for evaluation of chronic Chagas disease cardiomyopathy.

AIM: To determine whether cardiac magnetic resonance imaging (cMRI) is more sensitive than electrocardiogram (ECG) and echocardiogram (ECHO) for detecting myocardial involvement in a Latin American migrant population with untreated Chagas disease (CD) in the United States. MATERIALS AND METHODS: All untreated CD patients with ECG and ECHO examinations who underwent cMRI at Olive View-UCLA Medical Center from September 2010 to December 2013 (n=81) were analysed in three groups: Group 1, normal ECG and ECHO examinations (n=50); Group 2, abnormal ECG and normal ECHO examinations (n=10); and Group 3, abnormal ECHO examination (n=21). Frequencies of ECG, ECHO, and cMRI findings were compared across groups. RESULTS: Seventy percent (57/81) of the study population was female, with a mean age of 47 years (range, 17-77 years). Twenty-six percent (21/81) had delayed myocardial enhancement (DME), which was most commonly inferolateral in location (27%, 32/117 segments) and transmural in pattern (56%, 65/117 segments). Eight percent (4/50), 30% (3/10), and 67% (14/21) of Groups 1-3, respectively, had DME. Of these individuals with DME, 50% (2/4), 67% (2/3), and 100% (14/14) of Groups 1-3, respectively, also had wall motion abnormality (WMA) on cMRI. In addition to the highest percentages of DME and WMA, Group 3 also had significantly higher mean myocardial mass (p<0.01), mean left ventricular end-diastolic (p<0.01) and end-systolic volumes (p<0.0005), and significantly lower mean left ventricular ejection fraction (p<0.001). CONCLUSION: cMRI may detect myocardial involvement in untreated CD that is otherwise unrecognised on ECG and ECHO.

Endoscopic ultrasound-guided transmural drainage of infected pancreatic fluid collections with placement of covered self-expanding metal stents: a case series.

Endoscopic ultrasound-guided transmural drainage (EUS-GTD) has become the standard procedure for treating symptomatic pancreatic fluid collections. The aim of this series was to evaluate the efficacy and safety of covered self-expanding metal stent (CSEMS) placement for treating infected pancreatic fluid collections. From January 2007 to May 2010, 22 patients (18 M/4F; mean age 56.9) with infected pancreatic fluid collections (mean size, 13.2 cm) at two Italian centers were evaluated for EUS-GTD. In 20 of the 22 patients, EUS-GTD with CSEMS placement was indicated. Early complications occurred in two patients: one patient developed a superinfection, which was managed conservatively, and one experienced stent migration and superinfection, and was managed surgically. The CSEMSs were removed without difficulty in 18 patients after a median of 26 days, while stent removal failed in one patient due to inflammatory tissue ingrowth; instead it was removed during surgery performed for renal cancer. Clinical success was achieved without additional intervention in 17 patients during a mean follow-up of 610 days; only one symptomatic recurrence was observed. In our experience, EUS-GTD with CSEMS placement appears safe for the treatment of infected pancreatic fluid collections.

Fully covered metallic stents in biliary stenosis after orthotopic liver transplantation.

BACKGROUND AND STUDY AIMS: Data from a preliminary study suggested that the placement of a fully covered metal stent may be a valid alternative to surgery in patients who do not respond to standard endoscopic treatment. The aims of the current study were to evaluate the clinical success of self-expandable metallic stents (SEMS) in a large cohort of patients and with a long followup,and the effectiveness of SEMS placement as a first-line procedure. MATERIALS AND METHODS: Between January 2008 and August 2010, 54 consecutive patients with biliary complications following orthotopic liver transplantation were treated with SEMS placement:39 after failure of conventional endoscopic therapy (Group I), and 15 with no previous endoscopic treatment who were undergoing SEMS placement as first-line treatment for complications(Group II). RESULTS: In Group I, resolution after SEMS removal was observed in 71.8% of patients. Mean followup after resolution was 22.1 ±10 months. Recurrence of the complication was observed in 14.3%of patients after a mean of 8.5 months and SEMS migration was observed in 33.3% of patients. In Group II, resolution was observed in 53.3% of patients.Mean follow-up after resolution was 14.4±2.2 months. Recurrence was observed in 25% of patients and SEMS migration was observed in 46.7 %. CONCLUSIONS: For endotherapy of biliary complications after orthotopic liver transplantation, metallic stents should not be used as the primary modality. In patients in whom the standard approach fails, treatment with temporary SEMS placement can solve biliary complications in almost three-quarters of cases; however stent migration(33 %) remains a problem.

Fully covered self-expandable metallic stents in benign biliary strictures: a multicenter study on efficacy and safety.

BACKGROUND AND STUDY AIM: Benign biliary diseases include benign biliary stricture (BBS), lithiasis, and leaks. BBSs are usually treated with plastic stent placement; use of uncovered or partially covered metallic stents has been associated with failure related to mucosal hyperplasia. Some recently published series suggest the efficacy of fully covered self-expandable metal stents (FCSEMSs) in BBS treatment. We aimed to assess the efficacy and safety of FCSEMS in a large series of patients with BBS and a long follow-up.  PATIENTS AND METHODS: Prospective multicenter clinical study at three tertiary referral centers: ISMETT/UPMC Italy, Palermo, San Paolo Hospital, Milan, and the ARNAS Civico Hospital, Palermo, Italy. All consecutive patients with BBS were treated with placement of FCSEMS rather than plastic stents, as first approach (11 patients, 17.7 %), or as a second approach after failure of other treatments (51 patients, 82.2 %). RESULTS: From January 2008 to March 2011, 62 patients (40 male) were included. Mean period of FCSEMS indwelling was 96.7 days (standard deviation [SD] 6.5 days). In 15 patients (24.2 %) the SEMS migrated. Resolution of BBS occurred in 56 patients (90.3 %), while in 6 (9.6 %) the treatment failed. Mean (SD) follow-up after SEMS removal was 15.9 (10) months. FCSEMS placement as first- or second-line approach showed no difference in failure. Recurrence was observed in 4 /56 patients (7.1 %); all were transplant recipients: P = 0.01; odds ratio (OR) 1.2, confidence interval (CI) 1.1 - 1.3. CONCLUSIONS: Despite the noteworthy migration rate, FCSEMSs should be considered effective for refractory benign biliary strictures. Further studies are needed to assess their role as a first approach in the management of BBS.

The effects of a 3-week training on basal biomarkers in professional soccer players during the preseason preparation period.

AIM: The present study aimed at investigating the effect of a 3-week training on biomarkers in professional soccer players during the preseason preparation-period. METHODS: Eight participants (age 22.5±2.2 yrs) were enrolled in the study. During the physical preparation period players have attended a training program (51.9 hours) formulated by coaches of "Equipe-Sicilia-2009". RESULTS: At rest, the lipid profile, the creatine kinase (CK), the lactic-acid dehydrogenase (LDH) and the expression of nuclear receptors peroxisome-proliferator-activated receptors (PPAR α/γ) were analyzed before starting and after 3 weeks of training. The plasma level of CK in our samples showed great variability already in the baseline: value was on average nearly 500 IU/l showed that a large amount of these athletes were a high responders. This biomarker showed a reduction (P<0.01) after 3 weeks of training. No modifications were found in the LDH plasma level, in the lipid profile and in the expression of mRNA of PPAR α/γ and also no significant person's correlations were found among variables. CONCLUSION: In conclusion, we retain that those basal biomarkers, except CK, are not able to assist coaches to better understand training adaptations and overreaching mechanisms during a 3-week of preseason preparation-period. More studies are necessary to confirm these results.