bluuebunny/crossref_metadata_2025_split huggingface dataset:
Image simulation and a model of noise power spectra across a range of mammographic beam qualities
Authors: Mackenzie Alistair , Dance David R. , Diaz Oliver , Young Kenneth C. 
Published: November 2014

Purpose:The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities.Methods:Five detectors and x‐ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems.Results:The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise in CR. The use of the quantum noise correction factor reduced the difference from the model to the real NPS to generally within 4%. The use of the quantum noise correction improved the conversion of ASEh image to CRc image but had no difference for the conversion to CSI images.Conclusions:A practical method for estimating the NPS at any dose and over a range of beam qualities for mammography has been demonstrated. The noise model was incorporated into a methodology for converting an image to appear as if acquired on a different detector. The method can now be extended to work for a wide range of beam qualities and can be applied to the conversion of mammograms.
Characterization of energy response for photon‐counting detectors using x‐ray fluorescence
Authors: Ding Huanjun , Cho Hyo‐Min , Barber William C. , Iwanczyk Jan S. , Molloi Sabee 
Published: November 2014

Purpose:To investigate the feasibility of characterizing a Si strip photon‐counting detector using x‐ray fluorescence.Methods:X‐ray fluorescence was generated by using a pencil beam from a tungsten anode x‐ray tube with 2 mm Al filtration. Spectra were acquired at 90° from the primary beam direction with an energy‐resolved photon‐counting detector based on an edge illuminated Si strip detector. The distances from the source to target and the target to detector were approximately 19 and 11 cm, respectively. Four different materials, containing silver (Ag), iodine (I), barium (Ba), and gadolinium (Gd), were placed in small plastic containers with a diameter of approximately 0.7 cm for x‐ray fluorescence measurements. Linear regression analysis was performed to derive the gain and offset values for the correlation between the measured fluorescence peak center and the known fluorescence energies. The energy resolutions and charge‐sharing fractions were also obtained from analytical fittings of the recorded fluorescence spectra. An analytical model, which employed four parameters that can be determined from the fluorescence calibration, was used to estimate the detector response function.Results:Strong fluorescence signals of all four target materials were recorded with the investigated geometry for the Si strip detector. The average gain and offset of all pixels for detector energy calibration were determined to be 6.95 mV/keV and −66.33 mV, respectively. The detector's energy resolution remained at approximately 2.7 keV for low energies, and increased slightly at 45 keV. The average charge‐sharing fraction was estimated to be 36% within the investigated energy range of 20–45 keV. The simulated detector output based on the proposed response function agreed well with the experimental measurement.Conclusions:The performance of a spectral imaging system using energy‐resolved photon‐counting detectors is very dependent on the energy calibration of the detector. The proposed x‐ray fluorescence technique offers an accurate and efficient way to calibrate the energy response of a photon‐counting detector.
Bartonella chomelii Is the Most Frequent Species Infecting Cattle Grazing in Communal Mountain Pastures in Spain
Authors: Antequera-Gómez M. L. , Lozano-Almendral L. , Barandika J. F. , González-Martín-Niño R. M. , Rodríguez-Moreno I. , García-Pérez A. L. , Gil H. 
Published: November 2014

ABSTRACT

The presence of
Bartonella
spp. was investigated in domestic ungulates grazing in communal pastures from a mountain area in northern Spain, where 18.3% (17/93) of cattle were found to be positive by PCR combined with a reverse line blot (PCR/RLB), whereas sheep (
n
= 133) or horses (
n
= 91) were found not to be infected by this pathogen.
Bartonella
infection was significantly associated with age, since older animals showed a higher prevalence than heifers and calves. In contrast to other studies,
B. chomelii
was the most frequent species found in cattle (14/17), while
B. bovis
was detected in only three animals. Moreover, 18
B. chomelii
isolates and one
B. bovis
isolate were obtained from nine animals. Afterwards,
B. chomelii
isolates were characterized by a multilocus sequence typing (MLST) method which was adapted in this study. This method presented a high discrimination power, identifying nine different sequence types (STs). This characterization also showed the presence of different STs simultaneously in the same host and that STs had switched over time in one of the animals. In addition,
B. chomelii
STs seem to group phylogenetically in two different lineages. The only
B. bovis
isolate was characterized with a previously described MLST method. This isolate corresponded to a new ST which is located in lineage I, where the
B. bovis
strains infecting
Bos taurus
subsp.
taurus
are grouped. Further studies on the dynamics of
Bartonella
infection in cattle and the potential ectoparasites involved in the transmission of this microorganism should be performed, improving knowledge about the interaction of
Bartonella
spp. and domestic ungulates.
Tongue-tie and frenotomy in infants with breastfeeding difficulties: achieving a balance
Authors: Power R F , Murphy J F 
Published: November 2014

AimsCurrently there is debate on how best to manage young infants with tongue-tie who have breastfeeding problems. One of the challenges is the subjectivity of the outcome variables used to assess efficacy of tongue-tie division. This structured review documents how the argument has evolved. It proposes how best to assess, inform and manage mothers and their babies who present with tongue-tie related breastfeeding problems.MethodsDatabases were searched for relevant papers including Pubmed, Medline, and the Cochrane Library. Professionals in the field were personally contacted regarding the provision of additional data. Inclusion criteria were: infants less than 3 months old with tongue-tie and/or feeding problems. The exclusion criteria were infants with oral anomalies and neuromuscular disorders.ResultsThere is wide variation in prevalence rates reported in different series, from 0.02 to 10.7%. The most comprehensive clinical assessment is the Hazelbaker Assessment Tool for lingual frenulum function. The most recently published systematic review of the effect of tongue-tie release on breastfeeding concludes that there were a limited number of studies with quality evidence. There have been 316 infants enrolled in frenotomy RCTs across five studies. No major complications from surgical division were reported. The complications of frenotomy may be minimised with a check list before embarking on the procedure.ConclusionsGood assessment and selection are important because 50% of breastfeeding babies with ankyloglossia will not encounter any problems. We recommend 2 to 3 weeks as reasonable timing for intervention. Frenotomy appears to improve breastfeeding in infants with tongue-tie, but the placebo effect is difficult to quantify. Complications are rare, but it is important that it is carried out by a trained professional.
How context affects electronic health record-based test result follow-up: a mixed-methods evaluation
Authors: Menon Shailaja , Smith Michael W , Sittig Dean F , Petersen Nancy J , Hysong Sylvia J , Espadas Donna , Modi Varsha , Singh Hardeep 
Published: November 2014

ObjectivesElectronic health record (EHR)-based alerts can facilitate transmission of test results to healthcare providers, helping ensure timely and appropriate follow-up. However, failure to follow-up on abnormal test results (missed test results) persists in EHR-enabled healthcare settings. We aimed to identify contextual factors associated with facility-level variation in missed test results within the Veterans Affairs (VA) health system.Design, setting and participantsBased on a previous survey, we categorised VA facilities according to primary care providers’ (PCPs’) perceptions of low (n=20) versus high (n=20) risk of missed test results. We interviewed facility representatives to collect data on several contextual factors derived from a sociotechnical conceptual model of safe and effective EHR use. We compared these factors between facilities categorised as low and high perceived risk, adjusting for structural characteristics.ResultsFacilities with low perceived risk were significantly more likely to use specific strategies to prevent alerts from being lost to follow-up (p=0.0114). Qualitative analysis identified three high-risk scenarios for missed test results: alerts on tests ordered by trainees, alerts ‘handed off’ to another covering clinician (surrogate clinician), and alerts on patients not assigned in the EHR to a PCP. Test result management policies and procedures to address these high-risk situations varied considerably across facilities.ConclusionsOur study identified several scenarios that pose a higher risk for missed test results in EHR-based healthcare systems. In addition to implementing provider-level strategies to prevent missed test results, healthcare organisations should consider implementing monitoring systems to track missed test results.
Low dose thiopurine and allopurinol co-therapy results in significant cost savings at a district general hospital
Authors: Dharmasiri Suranga , Dewhurst Hannah , Johnson Heather , Weaver Sean , McLaughlin Simon 
Published: November 2014

BackgroundThiopurines are widely used for maintenance of remission in Crohn's disease (CD). Published data report >50% of patients stop thiopurines due to therapeutic failure, hepatitis or side effects. In this situation, many UK clinicians start biologics in CD patients. This has significant cost implications. An alternative strategy is low dose thiopurine and allopurinol (LDTA) co-therapy. We report the annual cost savings from adopting this strategy at our centre.MethodsPatients with CD treated with LDTA in preference to biological therapy were identified using a prospective local inflammatory bowel disease database. The annual drug cost of treatment with LDTA compared with biologic therapy was calculated. Cost of attending the day unit for an infusion was not included.Results26 patients with CD who failed standard dose thiopurine and were treated with LDTA were identified over a 12-month period and followed up for 1 year. 12 patients failed LDTA and progressed to biological therapy. The remaining 14 patients entered sustained clinical remission on LDTA. The cost savings achieved using the LDTA strategy in this group of patients was £146 413 per year with an average saving of £10 458 per patient per year.ConclusionsThis study has identified a significant annual cost savings with this treatment strategy through the prevention of escalation to biologics. These cost savings are likely to be even more significant in the long term since a significant proportion of patients treated with biological therapy require dose escalation. We believe adopting this strategy more widely could lead to significant healthcare savings.
Effectiveness of a brief primary care intervention to reduce passive smoking in babies: a cluster randomised clinical trial
Authors: Cuelva Guadalupe Ortega , Peña Carmen Cabezas , Ortega Jesús Almeda , Zafra Marc Saez , Moreno Jose L Ballvé , Esteban Jose A Pascual , Cuesta Cristina Castellà , Martín-Cantera Carlos , Cerezuela Esteve Saltó , Pou Rosa M Casademont , Alvarez Estela Díaz , Fernandez Joan Lozano , Jordán Concepció Morera , Trillo Araceli Valverde , Pérez-Ortuño Raúl , Ponce Lourdes Rofes , Checa Mireia Jané ,   The BIBE study group
Published: November 2014

BackgroundTobacco smoke pollution (TSP) has major negative effects on infant health. Our objectives were to determine the effectiveness of a brief primary care intervention directed at parents who smoke in reducing babies’ TSP exposure, and to establish variables related to greater exposure.MethodA multicentre, open, cluster-randomised clinical trial in Catalonia. The 83 participating primary health paediatric teams of the Catalan Health Service recruited 1101 babies whose parents were smokers. The intervention group (IG) received a brief TSP intervention; the control group (CG) received the usual care. Outcomes were measured by parents’ reported strategies to avoid TSP exposure. Baseline clinical data and characteristics of each baby's TSP exposure were collected, along with infant hair samples and parents’ tobacco use and related attitudes/behaviours. At 3-month and 6-month follow-up, behavioural changes to avoid TSP exposure were recorded; the association between reported parental behaviours and nicotine concentration in infant hair samples was tested in a random sample of 253 babies at baseline and 6 months.ResultsDuring follow-up, TSP-avoidance strategies improved more in the IG than in the CG: 35.4% and 26.9% ( p=0.006) at home, and 62.2% and 53.1% in cars (p=0.008). Logistic regression showed adjusted ORs for appropriate measures in the IG versus CG of 1.59 (95% CI 1.21 to 2.09) at home and 1.30 (95% CI 0.97 to 1.75) in cars. Hair samples showed that 78.7% of the babies tested were exposed. Reduced nicotine concentration was associated with improved implementation of effective strategies reported by parents at home (p=0.029) and in cars (p=0.014).ConclusionsThe intervention produced behavioural changes to avoid TSP exposure in babies. The proportion of babies with nicotine (>=1ng/mg) in hair samples at baseline is a concern.Trial registration numberClinical Trials.gov Identifier:NCT00788996.
Carotid stenting and intracranial thrombectomy for treatment of acute stroke due to tandem occlusions with aggressive antiplatelet therapy may be associated with a high incidence of intracranial hemorrhage
Authors: Heck Donald V , Brown Morry D 
Published: November 2014

BackgroundAcute stroke from tandem extracranial carotid artery and intracranial large vessel occlusion poses challenges for emergency endovascular treatment. Establishing and maintaining patency of the carotid artery and avoiding intracranial hemorrhage are competing concerns.MethodsTwenty-three consecutive cases of emergency carotid stenting followed by mechanical thrombectomy identified by retrospective review of the endovascular ischemic stroke database maintained prospectively at our institution since January 2011 form the basis for this report. No cases were lost to follow-up.ResultsPatients were selected with CT angiography or MR angiography and diffusion weighted imaging. Carotid stenting was successful in all cases, and establishment of Thrombolysis in Cerebral Ischemia 2A, 2B or 3 flow was successful in 21/23 (91%). 12/23 (52%) patients achieved a modified Rankin Scale score of 0–2 at 90 days. Symptomatic intracranial hemorrhage (SICH) occurred in 5/23 patients (22%). Of 13 patients receiving an intravenous loading dose of abciximab during the procedure, 4/13 had SICH (31%) compared with 1/10 (10%) of those who did not. Of seven patients who received intravenous tissue plasminogen activator prior to the procedure, none had SICH. 90-day mortality was 9/23 (39%). All patients who had SICH were above the median age.ConclusionsPrimary stenting of the extracranial carotid artery combined with intracranial mechanical thrombectomy can be an effective treatment for tandem occlusions, can be performed with a high rate of technical success, and can achieve good clinical outcomes in selected patients. However, the incidence of SICH may be higher than in other patient populations and may be associated with the use of abciximab and advanced patient age.
Low-Temperature Hydrothermal Synthesis of Hierarchical Porous Hydroxyapatite Microsphere with Co-substituted Essential Trace Elements for pH-responsive Drug Delivery
Authors: Wang Sha , Guo Zhiguang 
Published: November 2014

Hierarchical hydroxyapatite microspheres composed of two porous hemispherulites have been synthesized hydrothermally at 80°C. A possible formation mechanism was proposed. The drug loading and release properties were further investigated. [Formula: see text] 3D hierarchical microspheric hydroxyapatite (HAp) composed of two porous hemispherulites was hydrothermally fabricated at low temperature with the aid of urea and NaNO 3, Mg ( NO 3)2, KNO 3, NH 4 Cl and NH 4 F as the homogeneous precipitation reagent and substituted ion sources. In this novel strategy, the element-substitutions serve as regulating agents for the self-assembly of porous HAp microspheres from the dumbbell-like particles to two hemispheres with radius of about 10 μm. Furthermore, the as-prepared hierarchical HAp microspheres exhibit high drug-loading capability and superior sustained release properties, which make it a promising carrier for pH responsive drug delivery system.
B-Raf Inhibitors Induce Epithelial Differentiation inBRAF-Mutant Colorectal Cancer Cells
Authors: Herr Ricarda , Köhler Martin , Andrlová Hana , Weinberg Florian , Möller Yvonne , Halbach Sebastian , Lutz Lisa , Mastroianni Justin , Klose Martin , Bittermann Nicola , Kowar Silke , Zeiser Robert , Olayioye Monilola A. , Lassmann Silke , Busch Hauke , Boerries Melanie , Brummer Tilman 
Published: November 2014

AbstractBRAF mutations are associated with aggressive, less-differentiated and therapy-resistant colorectal carcinoma. However, the underlying mechanisms for these correlations remain unknown. To understand how oncogenic B-Raf contributes to carcinogenesis, in particular to aspects other than cellular proliferation and survival, we generated three isogenic human colorectal carcinoma cell line models in which we can dynamically modulate the expression of the B-RafV600E oncoprotein. Doxycyclin-inducible knockdown of endogenous B-RafV600E decreases cellular motility and invasion in conventional and three-dimensional (3D) culture, whereas it promotes cell–cell contacts and induces various hallmarks of differentiated epithelia. Importantly, all these effects are recapitulated by B-Raf (PLX4720, vemurafenib, and dabrafenib) or MEK inhibitors (trametinib). Surprisingly, loss of B-RafV600E in HT29 xenografts does not only stall tumor growth, but also induces glandular structures with marked expression of CDX2, a tumor-suppressor and master transcription factor of intestinal differentiation. By performing the first transcriptome profiles of PLX4720-treated 3D cultures of HT29 and Colo-205 cells, we identify several upregulated genes linked to epithelial differentiation and effector functions, such as claudin-1, a Cdx-2 target gene encoding a critical tight junction component. Thereby, we provide a mechanism for the clinically observed correlation between mutant BRAF and the loss of Cdx-2 and claudin-1. PLX4720 also suppressed several metastasis-associated transcripts that have not been implicated as targets, effectors or potential biomarkers of oncogenic B-Raf signaling so far. Together, we identify a novel facet of clinically applied B-Raf or MEK inhibitors by showing that they promote cellular adhesion and differentiation of colorectal carcinoma cells. Cancer Res; 75(1); 216–29. ©2014 AACR.
Loss of Estrogen-Regulated microRNA Expression Increases HER2 Signaling and Is Prognostic of Poor Outcome in Luminal Breast Cancer
Authors: Bailey Shannon T. , Westerling Thomas , Brown Myles 
Published: November 2014

Abstract
Among the genes regulated by estrogen receptor (ER) are miRNAs that play a role in breast cancer signaling pathways. To determine whether miRNAs are involved in ER-positive breast cancer progression to hormone independence, we profiled the expression of 800 miRNAs in the estrogen-dependent human breast cancer cell line MCF7 and its estrogen-independent derivative MCF7:2A (MCF7:2A) using NanoString. We found 78 miRNAs differentially expressed between the two cell lines, including a cluster comprising let-7c, miR99a, and miR125b, which is encoded in an intron of the long noncoding RNA LINC00478. These miRNAs are ER targets in MCF7 cells, and nearby ER binding and their expression are significantly decreased in MCF7:2A cells. The expression of these miRNAs was interrogated in patient samples profiled in The Cancer Genome Atlas (TCGA). Among luminal tumors, these miRNAs are expressed at higher levels in luminal A versus B tumors. Although their expression is uniformly low in luminal B tumors, they are lost only in a subset of luminal A patients. Interestingly, this subset with low expression of these miRNAs had worse overall survival compared with luminal A patients with high expression. We confirmed that miR125b directly targets HER2 and that let-7c also regulates HER2 protein expression. In addition, HER2 protein expression and activity are negatively correlated with let-7c expression in TCGA. In summary, we identified an ER-regulated miRNA cluster that regulates HER2, is lost with progression to estrogen independence, and may serve as a biomarker of poor outcome in ER+ luminal A breast cancer patients. Cancer Res; 75(2); 436–45. ©2014 AACR.