Observation of Ξ(1620)^{0} and Evidence for Ξ(1690)^{0} in Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+} Decays

We report the first observation of the double strange baryon Ξ(1620)^{0} in its decay to Ξ^{-}π^{+} via Ξ_{c}^{+}→Ξ^{-}π^{+}π^{+} decays based on a 980  fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The mass and width are measured to be 1610.4±6.0(stat)_{-4.2}^{+6.1} (syst)  MeV/c^{2} and 59.9±4.8(stat)_{-7.1}^{+2.8}(syst)  MeV, respectively. We obtain 4.0σ evidence of the Ξ(1690)^{0} with the same data sample. These results shed light on the structure of hyperon resonances with strangeness S=-2.

Search for a Light CP-odd Higgs Boson and Low-Mass Dark Matter at the Belle Experiment

We report on the first Belle search for a light CP-odd Higgs boson, A^{0}, that decays into low mass dark matter, χ, in final states with a single photon and missing energy. We search for events produced via the dipion transition ϒ(2S)→ϒ(1S)π^{+}π^{-}, followed by the on-shell process ϒ(1S)→γA^{0} with A^{0}→χχ, or by the off-shell process ϒ(1S)→γχχ. Utilizing a data sample of 157.3×10^{6} ϒ(2S) decays, we find no evidence for a signal. We set limits on the branching fractions of such processes in the mass ranges M_{A^{0}}<8.97  GeV/c^{2} and M_{χ}<4.44  GeV/c^{2}. We then use the limits on the off-shell process to set competitive limits on WIMP-nucleon scattering in the WIMP mass range below 5  GeV/c^{2}.

First Evidence for cos2β>0 and Resolution of the Cabibbo-Kobayashi-Maskawa Quark-Mixing Unitarity Triangle Ambiguity

We present first evidence that the cosine of the CP-violating weak phase 2β is positive, and hence exclude trigonometric multifold solutions of the Cabibbo-Kobayashi-Maskawa (CKM) Unitarity Triangle using a time-dependent Dalitz plot analysis of B^{0}→D^{(*)}h^{0} with D→K_{S}^{0}π^{+}π^{-} decays, where h^{0}∈{π^{0},η,ω} denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BABAR and Belle experiments collected at the ϒ(4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6}BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6}BB[over ¯] pairs recorded by the Belle detector. The results of the measurement are sin2β=0.80±0.14(stat)±0.06(syst)±0.03(model) and cos2β=0.91±0.22(stat)±0.09(syst)±0.07(model). The result for the direct measurement of the angle β of the CKM Unitarity Triangle is β=[22.5±4.4(stat)±1.2(syst)±0.6(model)]°. The measurement assumes no direct CP violation in B^{0}→D^{(*)}h^{0} decays. The quoted model uncertainties are due to the composition of the D^{0}→K_{S}^{0}π^{+}π^{-} decay amplitude model, which is newly established by performing a Dalitz plot amplitude analysis using a high-statistics e^{+}e^{-}→cc[over ¯] data sample. CP violation is observed in B^{0}→D^{(*)}h^{0} decays at the level of 5.1 standard deviations. The significance for cos2β>0 is 3.7 standard deviations. The trigonometric multifold solution π/2-β=(68.1±0.7)° is excluded at the level of 7.3 standard deviations. The measurement resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle.

Observation of ϒ(4S)→η^{'}ϒ(1S)

We report the first observation of the hadronic transition ϒ(4S)→η^{'}ϒ(1S), using 496  fb^{-1} data collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We reconstruct the η^{'} meson through its decays to ρ^{0}γ and to π^{+}π^{-}η, with η→γγ. We measure B(ϒ(4S)→η^{'}ϒ(1S))=[3.43±0.88(stat)±0.21(syst)]×10^{-5}, with a significance of 5.7σ.

Observation of an Excited Ω^{-} Baryon

Using data recorded with the Belle detector, we observe a new excited hyperon, an Ω^{*-} candidate decaying into Ξ^{0}K^{-} and Ξ^{-}K_{S}^{0} with a mass of 2012.4±0.7(stat)±0.6(syst)  MeV/c^{2} and a width of Γ=6.4_{-2.0}^{+2.5}(stat)±1.6(syst)  MeV. The Ω^{*-} is seen primarily in ϒ(1S),ϒ(2S), and ϒ(3S) decays.

Cognitive sequelae of methanol poisoning involve executive dysfunction and memory impairment in cross-sectional and long-term perspective

Methanol poisoning leads to lesions in the basal ganglia and subcortical white matter, as well as to demyelination and atrophy of the optic nerve. However, information regarding cognitive deficits in a large methanol sample is lacking. The principal aim of the present study was to identify the cognitive sequelae of methanol poisoning and their morphological correlates. A sample of 50 patients (METH; age 48 ± 13 years), 3-8 months after methanol poisoning, and 57 control subjects (CS; age 49 ± 13 years) were administered a neuropsychological battery. Forty-six patients were followed in 2 years' perspective. Patients additionally underwent 1.5T magnetic resonance imaging (MRI). Three biochemical and toxicological metabolic markers and a questionnaire regarding alcohol abuse facilitated the classification of 24 patients with methanol poisoning without alcohol abuse (METHna) and 22 patients with methanol poisoning and alcohol abuse (METHa). All groups were compared to a control group of similar size, and matched for age, education, premorbid intelligence level, global cognitive performance, and level of depressive symptoms. Using hierarchical multiple regression we found significant differences between METH and CS, especially in executive and memory domains. METHa showed a similar pattern of cognitive impairment with generally more severe executive dysfunction. Moreover, all METH patients with extensive involvement on brain MRI (lesions in ≥2 anatomical regions) had a more severe cognitive impairment. From a longitudinal perspective, we did not find any changes in their cognitive functioning after 2 years' follow-up. Our findings suggest that methanol poisoning is associated with executive dysfunction and explicit memory impairment, supposedly due to basal ganglia dysfunction and disruption of frontostriatal circuitry proportional to the number of brain lesions, and that these changes are persistent after 2 years' follow-up.

Markers of oxidative damage of nucleic acids and proteins among workers exposed to TiO2 (nano) particles

OBJECTIVE

The use of nanotechnology is growing enormously and occupational physicians have an increasing interest in evaluating potential hazards and finding biomarkers of effect in workers exposed to nanoparticles.

METHODS

A study was carried out with 36 workers exposed to (nano)TiO2 pigment and 45 controls. Condensate (EBC) titanium and markers of oxidation of nucleic acids (including 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), 5-hydroxymethyl uracil (5-OHMeU)) and proteins (such as o-tyrosine (o-Tyr), 3-chlorotyrosine (3-ClTyr) and 3-nitrotyrosine (3-NOTyr)) were analysed from samples of their exhaled breath.

RESULTS

In the production workshops, the median total mass 2012 and 2013 TiO2 concentrations were 0.65 and 0.40 mg/m(3), respectively. The median numbers of concentrations measured by the scanning mobility particle sizer (SMPS) and aerodynamic particle sizer (APS) were 1.98 × 10(4) and 2.32 × 10(4) particles/cm(3), respectively; and about 80% of those particles were smaller than 100 nm in diameter. In the research workspace, lower aerosol concentrations (0.16 mg/m(3) and 1.32 × 10(4) particles/cm(3)) were found. Titanium in the EBC was significantly higher in production workers (p<0.001) than in research workers and unexposed controls. Accordingly, most EBC oxidative stress markers, including in the preshift samples, were higher in production workers than in the two other groups. Multiple regression analysis confirmed an association between the production of TiO2 and the levels of studied biomarkers.

CONCLUSIONS

The concentration of titanium in EBC may serve as a direct exposure marker in workers producing TiO2 pigment; the markers of oxidative stress reflect the local biological effect of (nano)TiO2 in the respiratory tract of the exposed workers.

[Typing of Mycobacterium tuberculosis cultures from Samara region by the variable number of tandem repeats]

To type Mycobacterium tuberculosis (MT) strains by the variable number of tandem repeats (VNTR), 136 MT cultures, isolated in 5 main general therapeutic laboratories and penitentiary antituberculosis institutions of the Samara region, were studied. Gene typing revealed that the greatest number of MT strains (73) belonged to VNTR type 42435. It was followed by VNTR type 22232, found in 13 isolated cultures. Among the MT cultures of the most widely spread VNTR type 42435, rifampicin-resistant strains prevailed (57 strains, i.e. 78%), while strains belonging to VNTR type 22232 were mainly sensitive to rifampicin (84%). VNTR typing of MT typing may be useful for epidemiological studies in the field of phthisiology.

Latex aeroallergen quantification in hospitals of Moscow, Russia

BACKGROUND

Health care workers (HCWs) who use latex gloves regularly are at a significant risk for developing allergic sensitization to natural rubber latex (NRL) proteins. The airborne route of exposure presents a hazard for sensitization and subsequent allergic symptoms.

OBJECTIVE

The purpose of this study was to measure the content of the NRL proteins in the air of work areas (laboratories, treatment rooms, operating rooms, examination rooms, and dentist's treatment rooms) in eight Moscow hospitals where the employees used powdered latex gloves.

METHODS

The air samples were collected by a volumetric filtration method using a static air sampler at a flow rate of 3 L/second. Airborne particles were collected onto polytetrafluoroethylene filters rated 99.9% efficient at 0.3 microm. The NRL allergens were extracted from the air filter samples in phosphate-buffered saline and quantified by an inhibition immunoassay using a five-person pool of sera containing latex-specific human immunoglobulin E.

RESULTS

The airborne latex allergen concentrations in 11 areas (including positive control) where latex gloves were used varied from 5 to 26 ng/m3. Conversely, in 12 areas where latex gloves were seldom used or where powdered-free latex gloves were used allergen levels were not detectable (including two negative controls). The highest concentration of latex allergen (26 ng/m3) was found in an examination room of a gynecology department. Low and moderate concentrations were detected in most operating rooms, and low concentrations in the laboratories and treatment rooms.

CONCLUSIONS

This study indicates that, in general, the airborne NRL concentrations in the work areas of Moscow hospitals are rather low compared with NRL concentrations reported from American hospitals and are dependent on the intensity of latex glove usage.

Huge variation in Russian mortality rates 1984-94: artefact, alcohol, or what?

BACKGROUND

According to published data, between 1984 and 1994 mortality rates in Russia initially underwent a rapid decline followed by an even steeper increase. In 1994, male life expectancy at birth was 57.6 years, having fallen by 6.2 years since 1990. There has been concern that such striking fluctuations in mortality are an artefact, although, among other factors, alcohol consumption has been implicated.

METHODS

We analysed the age-specific and cause-specific patterns of mortality decrease and increase by use of data from a newly reconstructed mortality series for Russia so that we could examine the plausibility of various explanations for the mortality trends.

FINDINGS

All major causes of death, with the exception of neoplasms, showed declines in mortality between 1984 and 1987 and increases between 1987 and 1994. In relative terms, these tended to be largest for the age-group 40-50 years; surprisingly, they were of the same magnitude among women and men. The largest declines and subsequent increases in proportional terms were observed for alcohol-related deaths and accidents and violence. However, pronounced effects were also seen for deaths from infections, circulatory disease, and respiratory disease. No substantial variations were seen for neoplasms.

INTERPRETATION

The stability of mortality from neoplasms in contrast to other causes over the period 1984-94 largely precludes the possibility that the changes in life expectancy are mainly an artefact, particularly one due to underestimation of the population. Although factors such as nutrition and health services may be involved, the evidence is that substantial changes in alcohol consumption over the period could plausibly explain the main features of the mortality fluctuations observed. These results provide a major challenge to public health in Russia and to our understanding of the determinants of alcohol consumption and its role in explaining mortality patterns within and between many other countries.