269 research outputs found
Characterizing the local vectorial electric field near an atom chip using Rydberg state spectroscopy
We use the sensitive response to electric fields of Rydberg atoms to
characterize all three vector components of the local electric field close to
an atom-chip surface. We measured Stark-Zeeman maps of and Rydberg
states using an elongated cloud of ultracold Rubidium atoms ( K)
trapped magnetically m from the chip surface. The spectroscopy of
states yields a calibration for the generated local electric field at the
position of the atoms. The values for different components of the field are
extracted from the more complex response of states to the combined electric
and magnetic fields. From the analysis we find residual fields in the two
uncompensated directions of V/cm and V/cm
respectively. This method also allows us to extract a value for the relevant
field gradient along the long axis of the cloud. The manipulation of electric
fields and the magnetic trapping are both done using on-chip wires, making this
setup a promising candidate to observe Rydberg-mediated interactions on a chip.Comment: 8 pages, 5 figure
Observation of dipolar-induced spin dephasing in ionic solids using coherent optical-microwave spectroscopy
The observation of spin dephasing in an ensemble of dipolar coupled A and B spins is reported. In CaO crystals, the A-spin species are photoexcited S=1, F22+ centers and the group of B spins consists of S=1 / 2, F+ centers. Measurements were made at different temperatures and magnetic field strengths with use of coherent optical-microwave spectroscopy. For the first time, the results show that the A-spin dephasing is influenced by exchange narrowing in the B-spin ensemble
Immunologic biomarkers in relation to exposure markers of PCBs and dioxins in Flemish adolescents (Belgium).
In this study, we investigated 17- to 18-year-old boys and girls to determine whether changes in humoral or cellular immunity or respiratory complaints were related to blood serum levels of polychlorinated biphenyls (PCBs) and dioxin-like compounds after lifetime exposure in Flanders (Belgium). We obtained blood samples from and administered questionnaires to 200 adolescents recruited from a rural area and two urban suburbs. Physicians recorded medical history and respiratory diseases. We measured immunologic biomarkers such as differential blood cell counts, lymphocyte phenotypes, and serum immunoglobulins. As biomarkers of exposure, we determined the serum concentrations of PCBs (PCB 138, PCB 153, and PCB 180) and dioxin-like compounds [chemical-activated luciferase expression (CALUX) bioassay]. The percentages of eosinophils and natural killer cells in blood were negatively correlated with CALUX toxic equivalents (TEQs) in serum (p = 0.009 and p = 0.05, respectively). Increased serum CALUX TEQs resulted in an increase in serum IgA levels (p = 0.05). Furthermore, levels of specific IgEs (measured by radioallergosorbent tests) of cat dander, house dust mite, and grass pollen were also significantly and negatively associated with the CALUX TEQ, with odds ratios (ORs) equal to 0.63 [95% confidence interval (CI), 0.42-0.96], 0.68 (0.5-0.93), and 0.70 (0.52-0.95), respectively. In addition, reported allergies of the upper airways and past use of antiallergic drugs were negatively associated with CALUX TEQs, with ORs equal to 0.66 (0.47-0.93) and 0.58 (0.39-0.85), respectively. We found a negative association between IgGs and marker PCBs in serum (p = 0.009). This study shows that immunologic measurements and respiratory complaints in adolescents were associated with environmental exposure to polyhalogenated aromatic hydrocarbons (PHAHs). The negative correlation between PHAHs and allergic responses in adolescents suggested that exposure may entail alterations in the immune status
Designing a Virtual Hospital-at-Home Intervention for Patients with Infectious Diseases: A Data-Driven Approach
BACKGROUND: Virtual hospital-at-home care might be an alternative to standard hospital care for patients with infectious diseases. In this study, we explore the potential for virtual hospital-at-home care and a potential design for this population. METHODS: This was a retrospective cohort study of internal medicine patients suspected of infectious diseases, admitted between 1 January and 31 December 2019. We collected information on delivered care during emergency department visits, the first 24 h, between 24 and 72 h, and after 72 h of admission. Care components that could be delivered at home were combined into care packages, and the potential number of eligible patients per package was described. The most feasible package was described in detail. RESULTS: 763 patients were included, mostly referred for general internal medicine (35%), and the most common diagnosis was lower respiratory tract infection (27%). The most frequently administered care components were laboratory tests, non-oral medication, and intercollegiate consultation. With a combination of telemonitoring, video consultation, non-oral medication administration, laboratory tests, oxygen therapy, and radiological diagnostics, 48% of patients were eligible for hospital-at-home care, with 35% already eligible directly after emergency department visits. CONCLUSION: While the potential for virtual hospital-at-home care is high, it depends greatly on which care can be arranged
Under positive pressure: how stakeholder pressure affects corporate social responsibility implementation
This study tests a model that links stakeholder pressure to the implementation of corporate social responsibility (CSR) activities and market performance. Stakeholder groups and competitors might exert pressure on companies to implement CSR, which could lead to positive effects on market performance. Using structural equation modeling (SEM), the authors find that stakeholders and competitors exert pressure differently. The effect of CSR implementation on market performance is moderated by market dynamism: It affects market performance more in dynamic environments. The authors discuss implications for both companies and stakeholders
Sex-specific associations between particulate matter exposure and gene expression in independent discovery and validation cohorts of middle-aged men and women
BACKGROUND: Particulate matter (PM) exposure leads to premature death, mainly due to respiratory and cardiovascular diseases. OBJECTIVES: Identification of transcriptomic biomarkers of air pollution exposure and effect in a healthy adult population. METHODS: Microarray analyses were performed in 98 healthy volunteers (48 men, 50 women). The expression of eight sex-specific candidate biomarker genes (significantly associated with PM(10) in the discovery cohort and with a reported link to air pollution-related disease) was measured with qPCR in an independent validation cohort (75 men, 94 women). Pathway analysis was performed using Gene Set Enrichment Analysis. Average daily PM(2.5) and PM(10) exposures over 2-years were estimated for each participant’s residential address using spatiotemporal interpolation in combination with a dispersion model. RESULTS: Average long-term PM(10) was 25.9 (± 5.4) and 23.7 (± 2.3) μg/m(3) in the discovery and validation cohorts, respectively. In discovery analysis, associations between PM(10) and the expression of individual genes differed by sex. In the validation cohort, long-term PM(10) was associated with the expression of DNAJB5 and EAPP in men and ARHGAP4 (p = 0.053) in women. AKAP6 and LIMK1 were significantly associated with PM(10) in women, although associations differed in direction between the discovery and validation cohorts. Expression of the eight candidate genes in the discovery cohort differentiated between validation cohort participants with high versus low PM(10) exposure (area under the receiver operating curve = 0.92; 95% CI: 0.85, 1.00; p = 0.0002 in men, 0.86; 95% CI: 0.76, 0.96; p = 0.004 in women). CONCLUSIONS: Expression of the sex-specific candidate genes identified in the discovery population predicted PM(10) exposure in an independent cohort of adults from the same area. Confirmation in other populations may further support this as a new approach for exposure assessment, and may contribute to the discovery of molecular mechanisms for PM-induced health effects. CITATION: Vrijens K, Winckelmans E, Tsamou M, Baeyens W, De Boever P, Jennen D, de Kok TM, Den Hond E, Lefebvre W, Plusquin M, Reynders H, Schoeters G, Van Larebeke N, Vanpoucke C, Kleinjans J, Nawrot TS. 2017. Sex-specific associations between particulate matter exposure and gene expression in independent discovery and validation cohorts of middle-aged men and women. Environ Health Perspect 125:660–669; http://dx.doi.org/10.1289/EHP37
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