2,740 research outputs found
A High-Resolution Survey of HI Absorption toward the Central 200 pc of the Galactic Center
We present an HI absorption survey of the central 250 pc of the Galaxy. Very
Large Array (VLA) observations were made at 21 cm in the DnC and CnB
configurations and have a resolution of ~15"(0.6 pc at the Galactic Center (GC)
distance) and a velocity resolution of ~2.5 km/s. This study provides HI data
with high spatial resolution, comparable with the many high resolution
observations which have been made of GC sources over the past ten years. Here
we present an overview of the HI absorption toward ~40 well-known continuum
sources and a detailed comparison of the ionized, atomic and molecular
components of the interstellar medium for the Sgr B, Radio Arc and Sgr C
regions. In these well-known regions, the atomic gas appears to be closely
correlated in both velocity and distribution to the ionized and molecular gas,
indicating that it resides in photo-dissociation regions related to the HII
regions in the GC. Toward the majority of the radio continuum sources, HI
absorption by the 3-kpc arm is detected, constraining these sources to lie
beyond a 5 kpc distance in the Galaxy.Comment: 59 pages, including 41 figures; accepted for publication in
Astrophysical Journal Supplement Series in December 201
Individualising Chronic Care Management by Analysing Patients’ Needs – A Mixed Method Approach
Background: Modern health systems are increasingly faced with the challenge to provide effective, affordable and accessible health care for people with chronic conditions. As evidence on the specific unmet needs and their impact on health outcomes is limited, practical research is needed to tailor chronic care to individual needs of patients with diabetes. Qualitative approaches to describe professional and informal caregiving will support understanding the complexity of chronic care. Results are intended to provide practical recommendations to be used for systematic implementation of sustainable chronic care models.
Method: A mixed method study was conducted. A standardised survey (n = 92) of experts in chronic care using mail responses to open-ended questions was conducted to analyse existing chronic care programs focusing on effective, problematic and missing components. An expert workshop (n = 22) of professionals and scientists of a European funded research project MANAGE CARE was used to define a limited number of unmet needs and priorities of elderly patients with type 2 diabetes mellitus and comorbidities. This list was validated and ranked using a multilingual online survey (n = 650). Participants of the online survey included patients, health care professionals and other stakeholders from 56 countries.
Results: The survey indicated that current care models need to be improved in terms of financial support, case management and the consideration of social care. The expert workshop identified 150 patient needs which were summarised in 13 needs dimensions. The online survey of these pre-defined dimensions revealed that financial issues, education of both patients and professionals, availability of services as well as health promotion are the most important unmet needs for both patients and professionals.
Conclusion: The study uncovered competing demands which are not limited to medical conditions. The findings emphasise that future care models need to focus stronger on individual patient needs and promote their active involvement in co-design and implementation. Future research is needed to develop new chronic care models providing evidence-based and practical implications for the regional care setting
Operator Product Expansion of the Lowest Weight CPOs in N=4 SYM_4 at Strong Coupling
We present a detailed analysis of the 4-point functions of the lowest weight
chiral primary operators O^{I} \sim \tr \phi^{(i}\phi^{j)} in SYM
at strong coupling and show that their structure is compatible with the
predictions of AdS/CFT correspondence. In particular, all power-singular terms
in the 4-point functions exactly coincide with the contributions coming from
the conformal blocks of the CPOs, the R-symmetry current and the stress tensor.
Operators dual to string modes decouple at strong coupling. We compute the
anomalous dimensions and the leading corrections to the normalization
constants of the 2- and 3-point functions of scalar and vector double-trace
operators with approximate dimensions 4 and 5 respectively. We also find that
the conformal dimensions of certain towers of double-trace operators in the
{\bf 105}, {\bf 84} and {\bf 175} irreps are non-renormalized. We show that,
despite the absence of a non-renormalization theorem for the double-trace
operator in the {\bf 20} irrep, its anomalous dimension vanishes. As
by-products of our investigation, we derive explicit expressions for the
conformal block of the stress tensor, and for the conformal partial wave
amplitudes of a conserved current and of a stress tensor in dimensions.Comment: Latex, 47p, subsection 4.5 is modified, typos are correcte
On the Origin of the Wide HI Absorption Line Toward Sgr A*
We have imaged a region of about 5' extent surrounding Sgr A* in the HI 21
cm-line absorption using the Very Large Array. A Gaussian decomposition of the
optical depth spectra at positions within about 2' (approx. 5 pc at 8.5 kpc) of
Sgr A* detects a wide line underlying the many narrow absorption lines. The
wide line has a mean peak optical depth of 0.32 +/- 0.12 centered at a mean
velocity of V(lsr) = -4 +/- 15 km/s. The mean full width at half maximum is 119
+/- 42 km/s. Such a wide line is absent in the spectra at positions beyond
about 2' from Sgr A*. The position-velocity diagrams in optical depth reveal
that the wide line originates in various components of the circumnuclear disk
(radius approx. 1.3') surrounding Sgr A*. These components contribute to the
optical depth of the wide line in different velocity ranges. The
position-velocity diagrams do not reveal any diffuse feature which could be
attributed to a large number of HI clouds along the line of sight to Sgr A*.
Consequently, the wide line has no implications either to a global population
of shocked HI clouds in the Galaxy or to the energetics of the interstellar
medium as was earlier thought.Comment: LaTeX, 12 pages and 9 figures, accepted for publication in J.
Astrophys. Ast
The Role of the Mucus Barrier in Digestion
Mucus forms a protective layer across a variety of epithelial surfaces. In the gastrointestinal (GI) tract, the barrier has to permit the uptake of nutrients, while excluding potential hazards, such as pathogenic bacteria. In this short review article, we look at recent literature on the structure, location, and properties of the mammalian intestinal secreted mucins and the mucus layer they form over a wide range of length scales. In particular, we look at the structure of the gel-forming glycoprotein MUC2, the primary intestinal secreted mucin, and the influence this has on the properties of the mucus layer. We show that, even at the level of the protein backbone, MUC2 is highly heterogeneous and that this is reflected in the networks it forms. It is evident that a combination of charge and pore size determines what can diffuse through the layer to the underlying gut epithelium. This information is important for the targeted delivery of bioactive molecules, including nutrients and pharmaceuticals, and for understanding how GI health is maintained
A VLA H92alpha Study of the Arched Filament Complex Near the Galactic Center
The VLA has been used at 8.3 GHz in the DnC and CnB array configurations to
carry out an H92alpha recombination line study (at 8.3 GHz) of the ionized gas
in the Arched Filaments H II complex, which defines the western edge of the
Galactic center Radio Arc. The H92alpha line properties of the ionized gas are
consistent with photoionization from hot stars,and consistent with the physical
properties of other Galactic center H II regions. The LTE electron temperatures
vary only slightly across the entire extent of the source, and have an average
value of 6200 K. The velocity field is very complex, with velocities ranging
from +15 to - 70 km/s and the majority of velocities having negative values.
Large velocity gradients (2-7 km/s/pc, with gradients in some regions >10
km/s/pc) occur along each of the filaments, with the velocities becoming
increasingly negative with decreasing distance from the Galactic center. The
magnitudes of the velocity gradient are consistent with the cloud residing on
an inner, elongated orbit which is due to the Galaxy's stellar bar, or with a
radially infalling cloud. The ionization of the Arched Filaments can be
accounted for completely by the massive Arches stellar cluster, which consists
of > 150 O-stars. This cluster is likely to belocated 10-20 pc from the Arched
Filaments, which can explain the uniformity of ionization conditions in the
ionized gas.Comment: 29 pages, 22 figures embedded (some poor quality), accepted to the
Astronomical Journal (May 2001 issue), higher resolution figures available
from [email protected]
Investigation of conduction band structure, electron scattering mechanisms and phase transitions in indium selenide by means of transport measurements under pressure
In this work we report on Hall effect, resistivity and thermopower
measurements in n-type indium selenide at room temperature under either
hydrostatic and quasi-hydrostatic pressure. Up to 40 kbar (= 4 GPa), the
decrease of carrier concentration as the pressure increases is explained
through the existence of a subsidiary minimum in the conduction band. This
minimum shifts towards lower energies under pressure, with a pressure
coefficient of about -105 meV/GPa, and its related impurity level traps
electrons as it reaches the band gap and approaches the Fermi level. The
pressure value at which the electron trapping starts is shown to depend on the
electron concentration at ambient pressure and the dimensionality of the
electron gas. At low pressures the electron mobility increases under pressure
for both 3D and 2D electrons, the increase rate being higher for 2D electrons,
which is shown to be coherent with previous scattering mechanisms models. The
phase transition from the semiconductor layered phase to the metallic sodium
cloride phase is observed as a drop in resistivity around 105 kbar, but above
40 kbar a sharp nonreversible increase of the carrier concentration is
observed, which is attributed to the formation of donor defects as precursors
of the phase transition.Comment: 18 pages, Latex, 10 postscript figure
Intravenous sodium nitrite in acute ST-elevation myocardial infarction: a randomized controlled trial (NIAMI).
AIM: Despite prompt revascularization of acute myocardial infarction (AMI), substantial myocardial injury may occur, in part a consequence of ischaemia reperfusion injury (IRI). There has been considerable interest in therapies that may reduce IRI. In experimental models of AMI, sodium nitrite substantially reduces IRI. In this double-blind randomized placebo controlled parallel-group trial, we investigated the effects of sodium nitrite administered immediately prior to reperfusion in patients with acute ST-elevation myocardial infarction (STEMI).
METHODS AND RESULTS: A total of 229 patients presenting with acute STEMI were randomized to receive either an i.v. infusion of 70 μmol sodium nitrite (n = 118) or matching placebo (n = 111) over 5 min immediately before primary percutaneous intervention (PPCI). Patients underwent cardiac magnetic resonance imaging (CMR) at 6-8 days and at 6 months and serial blood sampling was performed over 72 h for the measurement of plasma creatine kinase (CK) and Troponin I. Myocardial infarct size (extent of late gadolinium enhancement at 6-8 days by CMR-the primary endpoint) did not differ between nitrite and placebo groups after adjustment for area at risk, diabetes status, and centre (effect size -0.7% 95% CI: -2.2%, +0.7%; P = 0.34). There were no significant differences in any of the secondary endpoints, including plasma troponin I and CK area under the curve, left ventricular volumes (LV), and ejection fraction (EF) measured at 6-8 days and at 6 months and final infarct size (FIS) measured at 6 months.
CONCLUSIONS: Sodium nitrite administered intravenously immediately prior to reperfusion in patients with acute STEMI does not reduce infarct size
pT3 colorectal cancer revisited: a multicentric study on the histological depth of invasion in more than 1000 pT3 carcinomas—proposal for a new pT3a/pT3b subclassification
BACKGROUND: Pathological TNM staging (pTNM) is the strongest prognosticator in colorectal carcinoma (CRC) and the foundation of its post-operative clinical management. Tumours that invade pericolic/perirectal adipose tissue generally fall into the pT3 category without further subdivision. METHODS: The histological depth of invasion into the pericolic/perirectal fat was digitally and conventionally measured in a training cohort of 950 CRCs (Munich). We biostatistically calculated the optimal cut-off to stratify pT3 CRCs into novel pT3a (≤3 mm)/pT3b (>3 mm) subgroups, which were then validated in two independent cohorts (447 CRCs, Bayreuth/542 CRCs, Mainz). RESULTS: Compared to pT3a tumours, pT3b CRCs showed significantly worse disease-specific survival, including in pN0 vs pN+ and colonic vs. rectal cancers (DSS: P < 0.001, respectively, pooled analysis of all cohorts). Furthermore, the pT3a/pT3b subclassification remained an independent predictor of survival in multivariate analyses (e.g. DSS: P < 0.001, hazard ratio: 4.41 for pT3b, pooled analysis of all cohorts). While pT2/pT3a CRCs showed similar survival characteristics, pT3b cancers remained a distinct subgroup with dismal survival. DISCUSSION: The delineation of pT3a/pT3b subcategories of CRC based on the histological depth of adipose tissue invasion adds valuable prognostic information to the current pT3 classification and implementation into current staging practices of CRC should be considered
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