171 research outputs found
Multivariate analysis of energy dispersive X-ray diffraction data for the detection of illicit drugs in border control
A system using energy dispersive X-ray diffraction has been tested to detect the presence of illicit drugs concealed within parcels typical of those which are imported into the UK via postal and courier services. The system was used to record diffraction data from calibration samples of diamorphine (heroin) and common cutting agents and a partial least squares regression model was established between diamorphine concentration and diffraction spectra. Parcels containing various crystalline and amorphous materials, including diamorphine, were then scanned to obtain multiple localised diffraction spectra and to form a hyperspectral image. The calibration model was used for the prediction of diamorphine concentration throughout the volume of parcels and enabled the presence and location of diamorphine to be determined from the visual inspection of concentration maps. This research demonstrates for the first time the potential of an EDXRD system to generate continuous hyperspectral images of real parcels from volume scanning in security applications and introduces the opportunity to explore hyperspectral image analysis in chemical and material identification. However, more work must be done to make the system ready for implementation in border control operations by bringing down the procedure time to operational requirements and by proving the system's portability
<i>miniPixD</i>: a compact sample analysis system which combines X-ray imaging and diffraction
This paper introduces miniPixD: a new, compact system that utilises transmission X-ray imaging and X-ray diffraction (XRD) to locate and identify materials of interest within an otherwise opaque volume. The system and the embodied techniques have utility in security screening, medical diagnostics, non-destructive testing (NDT) and quality assurance (QA). This paper outlines the design of the system including discussion on the choice of components and presents some data from relevant samples which are compared to other energy dispersive and angular dispersive XRD techniques
Etiology of Anemia in Patients With Advanced Heart Failure
ObjectivesWe prospectively investigated the causes of anemia in patients with advanced congestive heart failure (CHF).BackgroundAnemia is common in patients with advanced CHF, and its etiology is generally considered to be multifactorial. However, despite its importance, precise information is lacking regarding the prevalence of putative etiologic factors.MethodsPatients who were hospitalized for decompensated advanced CHF and who were stabilized after their initial treatment underwent evaluation of “clinically significant” anemia, defined as a hemoglobin content <12 g/dl for men and <11.5 g/dl for women. Patients with a serum creatinine concentration >3 mg/dl or patients with concurrent diseases that are known to cause anemia were not included. The initial evaluation included measurements of vitamin B12, folic acid, thyroid-stimulating hormone, erythropoietin, lactate dehydrogenase, Coombs test, multiple fecal occult tests, and bone marrow aspiration. Patients without diagnosis by these methods underwent red cell mass measurement with 51Cr assay.ResultsThe mean age of the 37 patients was 57.9 ± 10.9 years and mean left ventricular ejection fraction 22.5 ± 5.9%. Iron deficiency anemia was confirmed by bone marrow aspiration in 27 patients (73%), 2 patients (5.4%) had dilutional anemia, and 1 patient (2.7%) had drug-induced anemia. No specific cause was identified in 7 patients (18.9%) who were considered to have “anemia of chronic disease.” Serum ferritin for the iron-deficient patients was not a reliable marker of iron deficiency in this population.ConclusionsIn this group of patients, iron deficiency was the most common cause of anemia. The iron status of patients with end-stage chronic CHF should be thoroughly evaluated and corrected before considering other therapeutic interventions
The COSMOS-Web ring: in-depth characterization of an Einstein ring lensing system at z~2
Aims. We provide an in-depth analysis of the COSMOS-Web ring, an Einstein
ring at z=2 that we serendipitously discovered in the COSMOS-Web survey and
possibly the most distant lens discovered to date.
Methods. We extract the visible and NIR photometry from more than 25 bands
and we derive the photometric redshifts and physical properties of both the
lens and the source with three different SED fitting codes. Using JWST/NIRCam
images, we also produce two lens models to (i) recover the total mass of the
lens, (ii) derive the magnification of the system, (iii) reconstruct the
morphology of the lensed source, and (iv) measure the slope of the total mass
density profile of the lens.
Results. The lens is a very massive and quiescent (sSFR < 10^(-13) yr-1)
elliptical galaxy at z = 2.02 \pm 0.02 with a total mass Mtot(<thetaE) = (3.66
\pm 0.36) x 10^11 Msun and a stellar mass M* = (1.37 \pm 0.14) x 10^11 Msun.
Compared to SHMRs from the literature, we find that the total mass is
consistent with the presence of a DM halo of mass Mh = 1.09^(+1.46)_(-0.57) x
10^13 Msun. In addition, the background source is a M* = (1.26 \pm 0.17) x
10^10 Msun star-forming galaxy (SFR=(78 \pm 15) Msun/yr) at z = 5.48 \pm 0.06.
Its reconstructed morphology shows two components with different colors. Dust
attenuation values from SED fitting and nearby detections in the FIR also
suggest it could be partially dust-obscured.
Conclusions. We find the lens at z=2. Its total, stellar, and DM halo masses
are consistent within the Einstein ring, so we do not need any unexpected
changes in our description of the lens (e.g. change its IMF or include a
non-negligible gas contribution). The most likely solution for the lensed
source is at z = 5.5. Its reconstructed morphology is complex and highly
wavelength dependent, possibly because it is a merger or a main sequence galaxy
with a heterogeneous dust distribution.Comment: 16 pages, submitted to A&
Development and internal validation of a clinical prediction model for serious complications after emergency laparotomy
Purpose
Emergency laparotomy (EL) is a common operation with high risk for postoperative complications, thereby requiring accurate risk stratification to manage vulnerable patients optimally. We developed and internally validated a predictive model of serious complications after EL.
Methods
Data for eleven carefully selected candidate predictors of 30-day postoperative complications (Clavien-Dindo grade > = 3) were extracted from the HELAS cohort of EL patients in 11 centres in Greece and Cyprus. Logistic regression with Least Absolute Shrinkage and Selection Operator (LASSO) was applied for model development. Discrimination and calibration measures were estimated and clinical utility was explored with decision curve analysis (DCA). Reproducibility and heterogeneity were examined with Bootstrap-based internal validation and Internal–External Cross-Validation. The American College of Surgeons National Surgical Quality Improvement Program’s (ACS-NSQIP) model was applied to the same cohort to establish a benchmark for the new model.
Results
From data on 633 eligible patients (175 complication events), the SErious complications After Laparotomy (SEAL) model was developed with 6 predictors (preoperative albumin, blood urea nitrogen, American Society of Anaesthesiology score, sepsis or septic shock, dependent functional status, and ascites). SEAL had good discriminative ability (optimism-corrected c-statistic: 0.80, 95% confidence interval [CI] 0.79–0.81), calibration (optimism-corrected calibration slope: 1.01, 95% CI 0.99–1.03) and overall fit (scaled Brier score: 25.1%, 95% CI 24.1–26.1%). SEAL compared favourably with ACS-NSQIP in all metrics, including DCA across multiple risk thresholds.
Conclusion
SEAL is a simple and promising model for individualized risk predictions of serious complications after EL. Future external validations should appraise SEAL’s transportability across diverse settings
The Hellenic emergency laparotomy study (HELAS): a prospective multicentre study on the outcomes of emergency laparotomy in Greece
Background
Emergency laparotomy (EL) is accompanied by high post-operative morbidity and mortality which varies significantly between countries and populations. The aim of this study is to report outcomes of emergency laparotomy in Greece and to compare them with the results of the National Emergency Laparotomy Audit (NELA).
Methods
This is a multicentre prospective cohort study undertaken between 01.2019 and 05.2020 including consecutive patients subjected to EL in 11 Greek hospitals. EL was defined according to NELA criteria. Demographics, clinical variables, and post-operative outcomes were prospectively registered in an online database. Multivariable logistic regression analysis was used to identify independent predictors of post-operative mortality.
Results
There were 633 patients, 53.9% males, ASA class III/IV 43.6%, older than 65 years 58.6%. The most common operations were small bowel resection (20.5%), peptic ulcer repair (12.0%), adhesiolysis (11.8%) and Hartmann’s procedure (11.5%). 30-day post-operative mortality reached 16.3% and serious complications occurred in 10.9%. Factors associated with post-operative mortality were increasing age and ASA class, dependent functional status, ascites, severe sepsis, septic shock, and diabetes. HELAS cohort showed similarities with NELA patients in terms of demographics and preoperative risk. Post-operative utilisation of ICU was significantly lower in the Greek cohort (25.8% vs 56.8%) whereas 30-day post-operative mortality was significantly higher (16.3% vs 8.7%).
Conclusion
In this study, Greek patients experienced markedly worse mortality after emergency laparotomy compared with their British counterparts. This can be at least partly explained by underutilisation of critical care by surgical patients who are at high risk for death
The additional value of patient-reported health status in predicting 1-year mortality after invasive coronary procedures: A report from the Euro Heart Survey on Coronary Revascularisation
Objective: Self-perceived health status may be helpful in identifying patients at high risk for adverse outcomes. The Euro Heart Survey on Coronary Revascularization (EHS-CR) provided an opportunity to explore whether impaired health status was a predictor of 1-year mortality in patients with coronary artery disease (CAD) undergoing angiographic procedures. Methods: Data from the EHS-CR that included 5619 patients from 31 member countries of the European Society of Cardiology were used. Inclusion criteria for the current study were completion of a self-report measure of health status, the EuroQol Questionnaire (EQ-5D) at discharge and information on 1-year follow-up, resulting in a study population of 3786 patients. Results: The 1-year mortality was 3.2% (n = 120). Survivors reported fewer problems on the five dimensions of the EQ-5D as compared with non-survivors. A broad range of potential confounders were adjusted for, which reached a p<0.10 in the unadjusted analyses. In the adjusted analyses, problems with self-care (OR 3.45; 95% CI 2.14 to 5.59) and a low rating (≤ 60) on health status (OR 2.41; 95% CI 1.47 to 3.94) were the most powerful independent predictors of mortality, among the 22 clinical variables included in the analysis. Furthermore, patients who reported no problems on all five dimensions had significantly lower 1-year mortality rates (OR 0.47; 95% CI 0.28 to 0.81). Conclusions: This analysis shows that impaired health status is associated with a 2-3-fold increased risk of all-cause mortality in patients with CAD, independent of other conventional risk factors. These results highlight the importance of including patients' subjective experience of their own health status in the evaluation strategy to optimise risk stratification and management in clinical practice
Emerging roles of ATF2 and the dynamic AP1 network in cancer
Cooperation among transcription factors is central for their ability to execute specific transcriptional programmes. The AP1 complex exemplifies a network of transcription factors that function in unison under normal circumstances and during the course of tumour development and progression. This Perspective summarizes our current understanding of the changes in members of the AP1 complex and the role of ATF2 as part of this complex in tumorigenesis.Fil: Lopez Bergami, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; ArgentinaFil: Lau, Eric . Burnham Institute for Medical Research; Estados UnidosFil: Ronai, Zeev . Burnham Institute for Medical Research; Estados Unido
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