Characterization of 30 76 Ge enriched Broad Energy Ge detectors for GERDA Phase II.

The GERmanium Detector Array (Gerda) is a low background experiment located at the Laboratori Nazionali del Gran Sasso in Italy, which searches for neutrinoless double-beta decay of 76 Ge into 76 Se+2e - . Gerda has been conceived in two phases. Phase II, which started in December 2015, features several novelties including 30 new 76Ge enriched detectors. These were manufactured according to the Broad Energy Germanium (BEGe) detector design that has a better background discrimination capability and energy resolution compared to formerly widely-used types. Prior to their installation, the new BEGe detectors were mounted in vacuum cryostats and characterized in detail in the Hades underground laboratory in Belgium. This paper describes the properties and the overall performance of these detectors during operation in vacuum. The characterization campaign provided not only direct input for Gerda Phase II data collection and analyses, but also allowed to study detector phenomena, detector correlations as well as to test the accuracy of pulse shape simulation codes.

Probing Majorana neutrinos with double-ß decay.

A discovery that neutrinos are Majorana fermions would have profound implications for particle physics and cosmology. The Majorana character of neutrinos would make possible the neutrinoless double-ß (0νßß) decay, a matter-creating process without the balancing emission of antimatter. The GERDA Collaboration searches for the 0νßß decay of 76Ge by operating bare germanium detectors in an active liquid argon shield. With a total exposure of 82.4 kg⋅year, we observe no signal and derive a lower half-life limit of T 1/2 > 0.9 × 1026 years (90% C.L.). Our T 1/2 sensitivity, assuming no signal, is 1.1 × 1026 years. Combining the latter with those from other 0νßß decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 to 0.16 electron volts.

Improved Limit on Neutrinoless Double-ß Decay of

The GERDA experiment searches for the lepton-number-violating neutrinoless double-ß decay of ^{76}Ge (^{76}Ge→^{76}Se+2e^{-}) operating bare Ge diodes with an enriched ^{76}Ge fraction in liquid argon. The exposure for broad-energy germanium type (BEGe) detectors is increased threefold with respect to our previous data release. The BEGe detectors feature an excellent background suppression from the analysis of the time profile of the detector signals. In the analysis window a background level of 1.0_{-0.4}^{+0.6}×10^{-3} counts/(keV kg yr) has been achieved; if normalized to the energy resolution this is the lowest ever achieved in any 0νßß experiment. No signal is observed and a new 90% C.L. lower limit for the half-life of 8.0×10^{25} yr is placed when combining with our previous data. The expected median sensitivity assuming no signal is 5.8×10^{25} yr.

Results on neutrinoless double-ß decay of 76Ge from phase I of the GERDA experiment.

Neutrinoless double beta decay is a process that violates lepton number conservation. It is predicted to occur in extensions of the standard model of particle physics. This Letter reports the results from phase I of the Germanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory (Italy) searching for neutrinoless double beta decay of the isotope (76)Ge. Data considered in the present analysis have been collected between November 2011 and May 2013 with a total exposure of 21.6 kg yr. A blind analysis is performed. The background index is about 1 × 10(-2) counts/(keV kg yr) after pulse shape discrimination. No signal is observed and a lower limit is derived for the half-life of neutrinoless double beta decay of (76)Ge, T(1/2)(0ν) >2.1 × 10(25) yr (90% C.L.). The combination with the results from the previous experiments with (76)Ge yields T(1/2)(0ν)>3.0 × 10(25) yr (90% C.L.).

Statistical analysis of low-level material screening measurements via gamma-spectroscopy.

Background estimations in neutrinoless double beta decay experiments (0nubetabeta) require reliable statistical limits on gamma-spectrometric low-level material screening measurements. For this purpose a custom method based on Bayesian statistics with reference to the international standard ISO 11929-7 is presented. The analysis combines the data from sample- and background spectra and comprises the physical knowledge of non-negative counting rates. It allows to incorporate multiple gamma lines of radionuclides. The confidence intervals pass continuously from two-sided intervals into single-sided upper limits.

Gamma-ray spectrometry of ultra low levels of radioactivity within the material screening program for the GERDA experiment.

In present and future experiments in the field of rare events physics a background index of 10(-3) counts/(keV kg a) or better in the region of interest is envisaged. A thorough material screening is mandatory in order to achieve this goal. The results of a systematic study of radioactive trace impurities in selected materials using ultra low-level gamma-ray spectrometry in the framework of the GERDA experiment are reported.

Optimisation of the MC-model of a p-type Ge-spectrometer for the purpose of efficiency determination.

An optimisation of the geometrical model of a p-type detector used for material screening was carried out to improve the accuracy of Monte Carlo simulations in reproducing spectrometric measurements. Gamma-ray sources were measured to determine the dimensions of the detector dead layer and borehole. An agreement between simulations and measurement within 3% was achieved at energies above 100 keV. In contrast, discrepancies on the order of 23% were encountered using the nominal parameters from the detector manufacturer.

Use of recombinant factor VIIa (rFVIIa) to control intraoperative bleeding in pediatric brain tumor patients.

Surgical bleeding during the resection of brain tumors in children may be related to tumor vascularity, pathology, and location. Despite improvements in neurosurgical technique, neuroanesthesia, and blood product replacement, bleeding can be life-threatening in these surgeries. We report eight pediatric patients in whom recombinant factor VIIa (rFVIIa) was used to control intraoperative bleeding during surgical resection of pediatric brain tumors. rFVIIa should be considered as a method to control intraoperative bleeding that is unresponsive to conventional interventions. Additional studies are needed to determine optimal patient selection and drug dosing, efficacy and safety.

Human coagulation factor FVIIa (recombinant) in the management of limb-threatening bleeds unresponsive to alternative therapies: results from the NovoSeven emergency-use programme in patients with severe haemophilia or with acquired inhibitors.

This open-label, emergency-use study evaluated the efficacy and safety of activated human coagulation factor VIIa (recombinant) (rFVIIa) (NovoSeven; Novo Nordisk Pharmaceuticals, Inc., New Jersey, USA) in treating limb-threatening joint or muscle bleeds in 17 patients with haemophilia A or B and six patients with acquired inhibitors to factor VIII or factor IX. All patients had previously failed on one or more alternative therapies. rFVIIa administration was effective or partially effective in controlling joint or muscle bleeds in 34 out of 35 (97%) bleeding episodes; in 23 patients, 14 of 17 (82%) muscle bleeds and 16 of 18 (89%) joint bleeds were effectively controlled. These findings suggest that rFVIIa is an effective and well-tolerated therapeutic option in the management of joint or muscle haemorrhage in patients with haemophilia and in patients with acquired inhibitors.

The use of implantable venous access devices (IVADs) in children with hemophilia.

PURPOSE: Implantable venous access devices (IVADs), either centrally or peripherally implanted, have become increasingly popular in children with hemophilia to assist in the early treatment of bleeding episodes and in the prevention of arthropathy. Their use has been associated with complications including thrombosis, thrombophlebitis, and infection. We attempted to better define whether the benefits associated with IVADs in this population outweight the associated risks. PATIENTS AND METHODS: We studied the medical records of 35 children from the University of Minnesota's Comprehensive Hemophilia Center who received IVADs between 1992 and 1996. RESULTS: There was no bleeding or thrombophlebitis associated with IVADs in our population. One patient required removal of a central IVAD due to thrombosis. The central IVADs were associated with local infection and bacteremia rates of 3% and 33%, respectively. The rates of local infection and bacteremia associated with peripheral IVADs were both 25%. The majority of infections were cleared with antibiotics, and ports remained intact. Both types of IVADs were associated with a high patient/parent satisfaction. CONCLUSION: Despite being associated with a significant incidence of infection, we believe the benefits of IVADs for children with hemophilia and their families outweigh the risks. Possible explanations for the observed infection rates are discussed.

Feasibility study for neonatal neuroblastoma screening in the United States.

Urine was obtained from infants born at two large metropolitan Minneapolis/St. Paul, Minnesota hospitals to determine whether normal levels of urinary catecholamine metabolites in neonates can be used for subsequent neuroblastoma screening as well as to determine compliance with collecting such urine in a voluntary program. The results suggest that there are wide variations in raw values of urinary creatinine, homovanillic acid, and vanillylmandelic acid through the first 4 days of age, apparently because of maternal creatinine and catecholamine metabolite influences. Such maternal influences appear negligible by 3 weeks of age. Furthermore, the study suggests that voluntary compliance in the United States with collecting urine at home without rigorous public education and/or methods for reminding parents may be very poor.

Intrathoracic extravasation of sclerosing agents associated with central venous catheters.

Two children receiving continuous infusions of vesicant chemotherapy through central venous catheters (CVCs) developed venous thrombosis, and intrathoracic extravasations ensued. One child receiving a continuous vincristine infusion presented with signs of thoracic venous obstruction, fever, and respiratory distress and had pleural effusions and pulmonary infiltrates on his chest roentgenogram. The other child was receiving a continuous doxorubicin infusion and developed superior vena cava thrombosis and retrograde extravasation along the catheter tunnel site. Both children improved after chemotherapy was discontinued and the CVCs removed. Catheter placement and the continuous infusion of sclerosing agents are discussed.

Older women in developing countries.

Women's issues are markedly underrepresented in international policy and research discussions. This paper addresses these deficits by delineating the particular conditions of aging women in developing countries. While these women experience many of the age-related problems as their counterparts in developed countries, cultural and economic influences place them at a greater disadvantage.

Congenital pernicious anemia: report of seven patients, with studies of the extended family.

Seven children ages 1 1/2 to 12 years with congenital pernicious anemia were detected in an extended Mexican family. All affected children had megaloblastic anemia accompanied by low serum B12 and normal serum folate levels. Gastric fluid analysis in six patients revealed normal gastric acidity and absent intrinsic factor. Serum antibodies to intrinsic factor or parietal cells were also absent. Schilling tests performed in six of the seven patients yielded abnormal results. Of the three patients in whom gastric biopsy was done, two had normal histologic findings (including examination by electron microscopy) and one had mild atrophy. All patients responded rapidly to parenterally administered vitamin B12 therapy. In addition, 170 family members were screened for the defect with complete blood counts and serum B12 levels. Such screening detected pernicious anemia in two of the children, but no other abnormalities that could be attributed to pernicious anemia were found in other family members. Based on the family pedigree, autosomal recessive inheritance is likely. The variability of age of presentation in this family is noteworthy and suggests that expression may be modified by still undefined factors.

Effects of X-irradiation on artificial blood vessel wall degradation by invasive tumor cells.

Artificial vessel wall cultures, constructed by growing arterial endothelial cells on preformed layers of rat smooth muscle cells, were used to evaluate the effects of X-irradiation on tumor cell-induced tissue degradation. Bovine endothelial cells had radiation sensitivities similar to those of rat smooth muscle cells. Preirradiation of smooth muscle cells, before the addition of human fibrosarcoma (HT 1080) cells, did not increase the rate of degradation and destruction by the invasive cells. However, the degradation rate was decreased if the cultures were irradiated after the addition of HT 1080 cells. The presence of bovine endothelial cells markedly inhibited the destructive abilities of fibrosarcoma cells, but preirradiation of artificial vessel walls substantially decreased their capabilities to resist HT 1080-induced lysis. These findings suggest that the abilities of blood vessels to limit extravasation may be compromised by ionizing radiation.

Aging in the context of population policies in developing countries.

PIP: In spite of the continued low proportion of the aged in their population, developing countries can anticipate a substantial increment in the number of older persons by the end of this century and still higher rates of increase after that. Demographic changes such as reduced fertility and migration can lead to harsh conditions for the aged, unless there is full awareness of their predicament and policies to deal with ensuing problems. The present study examines the perceptions and policies on aging by Governments in the developing regions of the world. 2 recent sets of data were analysed to obtain information: 1) documents from the World Assembly on Aging held at Vienna in 1982, particularly reports and statements by 52 developing countries on the situation of the aged; 2) an analysis of the 5th Population inquiry among Governments, conducted by the UN in 1983 to monitor a broad range of government policies and perceptions on demographic trends in relation to development. The analysis reveals substantial concern in developing countries with the health and welfare of the rising number of older persons in their populations, expressed in 46 of the World Assembly statements. Interest in policies to benefit the aged was not limited to countries with relatively higher proportions of older persons; it was also present in some with very young populations, such as among African nations. The analysis of the 5th Population Inquiry showed that, even though the questionnaire referred to the aging issue in only a limited and indirect manner, 1/3 of the developing countries (30 of 89 responses) expressed "aging concern" in responding to the questionnaire. Many governments recommended that the issue of aging be discussed at the International Conference on Population to be held in Mexico in 1984.^ieng

Inhibition by bovine endothelial cells of degradation by HT-1080 fibrosarcoma cells of extracellular matrix proteins.

Medium conditioned by bovine arterial endothelial cells inhibited the degradation by human fibrosarcoma cells of living cultures of rat smooth muscle cells or their cell-free extracellular matrices. Endothelial cell-conditioned medium had no effect on the growth kinetics of fibrosarcoma cells, and the inhibitory influence of conditioned medium on matrix degradation was greatest with low numbers of tumor cells. Conditioned medium inhibited the production of tumor cell plasminogen activators, enzymes previously found to play a role in matrix glycoprotein degradation. The endothelial factor was heat- and acid-stable and non-dialyzable, and mixing experiments showed that it did not directly inactivate the tumor cell plasminogen activator. Endothelial cells may therefore modulate the production of proteolytic enzymes important in the implantation stage of tumor metastasis.

Hypertension in children with neurogenic tumors.

Fifty-nine children with neurogenic tumors were examined for the presence of hypertension. Eleven of the 59 (19%) were found to have elevated blood pressure levels at the time of diagnosis or with progression of their disease. Several antihypertensive agents produced poor or only partial pressure control. All blood pressure levels returned to normal values after tumor excision or administration of effective antitumor therapy. There was no correlation of hypertension with urinary catecholamine levels. The etiologies of hypertension in children with neurogenic tumors are discussed.

Radionuclide bone scan in neuroblastoma.

A comparison of radionuclide bone scans with other methods of monitoring disease status was undertaken in a series of 51 children with neuroblastoma. The radionuclide bone scan was more accurate than either conventional radiographic studies or physical examination in localizing the primary tumor. When the extent of bony metastatic disease was evaluated, the bone scan and radiographic skeletal surveys were generally both positive, but the bone scan tended to show evidence of greater metastatic disease than radiographs.