First Directional Measurement of Sub-MeV Solar Neutrinos with Borexino

We report the measurement of sub-MeV solar neutrinos through the use of their associated Cherenkov radiation, performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The measurement is achieved using a novel technique that correlates individual photon hits of events to the known position of the Sun. In an energy window between 0.54 to 0.74 MeV, selected using the dominant scintillation light, we have measured 10 887_{-2103}^{+2386}(stat)±947(syst) (68% confidence interval) solar neutrinos out of 19 904 total events. This corresponds to a ^{7}Be neutrino interaction rate of 51.6_{-12.5}^{+13.9}  counts/(day·100  ton), which is in agreement with the standard solar model predictions and the previous spectroscopic results of Borexino. The no-neutrino hypothesis can be excluded with >5σ confidence level. For the first time, we have demonstrated the possibility of utilizing the directional Cherenkov information for sub-MeV solar neutrinos, in a large-scale, high light yield liquid scintillator detector. This measurement provides an experimental proof of principle for future hybrid event reconstruction using both Cherenkov and scintillation signatures simultaneously.

Recent Borexino results and perspectives of the SOX measurement

Borexino is a liquid scintillator detector sited underground in the Laboratori Nazionali del Gran Sasso (Italy). Its physics program, until the end of this year, is focussed on the study of solar neutrinos, in particular from the Beryllium, pp, pep and CNO fusion reactions. Knowing the reaction chains in the sun provides insights towards physics disciplines such as astrophysics (star physics, star formation, etc.), astroparticle and particle physics. Phase II started in 2011 and its aim is to improve the phase I results, in particular the measurements of the neutrino fluxes from the pep and CNO processes. By the end of this year, data taking from the sun will be over and a new project is scheduled to launch: Short distance Oscillation with boreXino (SOX), which uses a Cerium source for neutrinos (100÷150 kCi of activity) and aims to confirm or rule out the presence of sterile neutrinos. This particle is hypothesised to justify the reactor, Gallium and LSND anomalies found and can reject extensions to the standard model. The work presented is a summary of the solar neutrino results achieved so far, which lead not only to a precise study of the processes in the sun, but also to more Standard Model oriented measurements (such as the stability of the charge, i.e. the life time of the electron). Furthermore, the perspectives of the SOX program are discussed showing the experiment sensitivity to a fourth neutrino state covering almost entirely 3σ of the preferred region of the anomalous neutrino experiments, and additional applications of the detector such as the study of geo-neutrinos.

Test of Electric Charge Conservation with Borexino

Borexino is a liquid scintillation detector located deep underground at the Laboratori Nazionali del Gran Sasso (LNGS, Italy). Thanks to the unmatched radio purity of the scintillator, and to the well understood detector response at low energy, a new limit on the stability of the electron for decay into a neutrino and a single monoenergetic photon was obtained. This new bound, τ≥6.6×10^{28}  yr at 90% C.L., is 2 orders of magnitude better than the previous limit.

Evaluation of four Narcissus cultivars as potential sources for galanthamine production

Galanthamine, an alkaloid present in the Amaryllidaceae is currently undergoing clinical trials for the treatment of Alzheimer's. Common daffodils, Narcissus spp., contain galanthamine and other alkaloids. Four commercial Narcissus cultivars were evaluated as potential sources of galanthamine. Planting depths, planting densities, bulb size or flower bud removal did not affect galanthamine content.

Transnasal transesophageal echocardiography

Transesophageal echocardiography has been used as a diagnostic tool in the critical care unit. However, long-term serial evaluation of ventricular function with transesophageal echocardiography is difficult because of the current probe sizes and intolerance to prolonged oral intubation. We performed 139 intubations (64 oral and 75 transnasal) with a new prototype probe in 128 patients referred for transesophageal echocardiography. Transnasal intubation with the prototype probe was possible in 63/75 attempts. Oral intubation was successful in all 64 attempts. Patients tolerated transnasal intubation well when mildly sedated or awake. Two-dimensional echocardiographic views obtained with the nasal probe were similar to those obtained with a standard monoplane probe. Image quality was rated as good or acceptable in nearly all cases. Transgastric short-axis imaging of the left ventricle combined with acoustic quantification provided stable left ventricular area waveforms. Using custom developed software we showed the feasibility of monitoring left ventricular performance with minimal probe adjustment while graphically displaying and updating left ventricular area and fractional area change. Thus, transesophageal echocardiography with a prototype miniaturized monoplane probe passed transnasally is feasible, safe, and well tolerated by patients. This probe provides excellent two-dimensional echocardiographic images and may allow long-term echocardiographic monitoring of ventricular performance.

HIV infection in healthcare workers. How great is the risk? What can be done before and after exposure?

Healthcare workers know that there is a risk of HIV infection through exposure to AIDS patients. In both hospital and office settings, physicians have the opportunity to set standards and promote education about the degree of risk, effective precautions, and postexposure testing, prophylaxis, and treatment. Drs Henry and Thurn share the latest findings and offer policy recommendations based on their own experience.

Needlestick injuries and needle disposal in Minnesota nursing homes

We examined needle use and disposal, needlestick injuries and their management, and employee education regarding the acquired immunodeficiency syndrome and needle use by means of a questionnaire sent to all long-term care facilities certified for skilled care in Minnesota. Responses were received from 297 of 349 (85.1%) homes. Nearly all homes (271 of 293; 92.5%) provided education for new nursing employees about use and disposal of needles. Disposal of needles and sharps was generally consistent with current recommendations for short-term care hospitals. Needlestick injuries were usually related to recapping and were most common in registered and licensed practical nurses but were infrequent (i.e., less than 1 injury per home per employee-year) probably because parenteral therapy is infrequently used in long-term care settings. Only slightly over half (166 of 286; 58%) of the homes had protocols for management of needlestick injuries. Although Minnesota nursing homes properly dispose of needles and sharps, many of these institutions need to develop policies for management of needlestick injuries that are consistent with current recommendations.

Enteral hyperalimentation as a source of nosocomial infection

Microbial growth in enteral nutrition solutions (ENS) has frequently been documented. To determine the relation of this contamination to nosocomial infection, we prospectively studied 24 intensive care unit patients who received enteral feeding. Cultures of solutions were obtained while refrigerated and during administration as well as pharyngeal and rectal cultures from patients at the start of enteral nutrition and serially during administration. Most patients (10/16, 62.5%) receiving solutions mixed on the ward and 3/14 (21.4%) receiving solutions prepared elsewhere appeared to become colonized (0.05 less than P less than 0.10) by organisms initially isolated from feeds. By antibiotic susceptibility and plasmid analysis, eight patients were found to be colonized by 11 organisms identical to those which were first isolated from ENS. Two of these patients had ENS-associated pneumonias caused by Acinetobacter baumannii. Solutions often contained multiple Gram-negative bacilli similar to those recovered from nurses' hands and blenders, in numbers up to 1 x 10(8) ml-1. We conclude that ENS may be an important source of nosocomial infection. Uniform microbial criteria for ENS should be developed and methods to limit contamination should be utilized.

The evolving challenge of Pneumocystis carinii. A deadly opportunist in AIDS

Considerable progress has been made in the identification and treatment of Pneumocystis carinii pneumonia related to acquired immunodeficiency syndrome (AIDS). Prophylaxis, either primary or secondary, represents a major advance and should be used appropriately by physicians caring for patients infected with human immunodeficiency virus. Yet with success come new challenges. Centers for treatment of AIDS that aggressively use prophylaxis have seen a shift toward severe illness due to other pathogens and generalized wasting. The strategies employed in combating P carinii pneumonia are likely to be tried against other AIDS-related infections.

Needlestick injuries and needle disposal in Minnesota physicians' offices

Because little is known about needlestick injury and needle disposal in non-hospital settings, we surveyed physicians' offices in Minnesota. Recapping of needles was frequent (51.1%, 72 of 141) and injuries had occurred during the past year in 44.0% of offices. When of known cause, needlesticks were most common during blood drawing and recapping (52.0%, 13 of 25). Small offices more often recapped needles, but only metropolitan small offices reported more frequent injuries. Only 37.6% of offices used a protocol for management of injuries, and in less than half (45.4%) was physician evaluation routine. Although most offices used plastic containers and a majority (73.0%) incinerated or autoclaved needles prior to disposal, small offices more often disposed of sharps in their routine solid waste. Larger metropolitan offices more consistently followed current recommendations for handling and disposing of needles. There is a need for education efforts to address these issues for physicians and their office staff.

Human parvovirus B19: historical and clinical review

Human parvovirus B19 has been associated with disease only for the past few years. First isolated from sera obtained for studies on hepatitis B in 1975, it was not until 1981 that infection with this small, single-stranded DNA virus was related to aplastic crisis associated with hemolytic anemia. A nonspecific viral prodrome, the occurrence in family members, and epidemics of aplastic crisis suggested the infectious etiology. Human parvovirus infection has since been associated with arthritis, erythema infectiosum (fifth disease), fetal death, and hydrops fetalis. Through the use of recently developed serologic tests, epidemics of erythema infectiosum and parvoviral infection have been related not only to aplastic crisis but also to intrauterine infection and hydrops; DNA hybridization studies have allowed the detection of viral DNA in serum and tissue extracts. Studies have been hampered by the lack of an ability to culture the virus, but this is now possible utilizing bone marrow culture and erythropoietin. This article is a historical and clinical review of human parvovirus infection and disease and considers potential questions regarding their consequences.