bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of rheumatoid arthritis diagnoses in health care utilization data
Authors: Kim Seo Young , Servi Amber , Polinski Jennifer M , Mogun Helen , Weinblatt Michael E , Katz Jeffrey N , Solomon Daniel H 
Published: February 2011

Abstract
Introduction
Health care utilization databases have been increasingly used for studies of rheumatoid arthritis (RA). However, the accuracy of RA diagnoses in these data has been inconsistent.

Methods
Using medical records and a standardized abstraction form, we examined the positive predictive value (PPV) of several algorithms to define RA diagnosis using claims data: A) at least two visits coded for RA (ICD-9, 714); B) at least three visits coded for RA; and C) at least two visits to a rheumatologist for RA. We also calculated the PPVs for the subgroups identified by these algorithms combined with pharmacy claims data for at least one disease-modifying anti-rheumatic drug (DMARD) prescription.

Results
We invited 9,482 Medicare beneficiaries with pharmacy benefits in Pennsylvania to participate; 2% responded and consented for review of their medical records. There was no difference in characteristics between respondents and non-respondents. Using 'RA diagnosis per rheumatologists' as the gold standard, the PPVs were 55.7% for at least two claims coded for RA, 65.5% for at least three claims for RA, and 66.7% for at least two rheumatology claims for RA. The PPVs of these algorithms in patients with at least one DMARD prescription increased to 86.2%-88.9%. When fulfillment of 4 or more of the ACR RA criteria was used as the gold standard, the PPVs of the algorithms combined with at least one DMARD prescriptions were 55.6%-60.7%.

Conclusions
To accurately identify RA patients in health care utilization databases, algorithms that include both diagnosis codes and DMARD prescriptions are recommended.
Utility and safety of draining pleural effusions in mechanically ventilated patients: a systematic review and meta-analysis
Authors: Goligher Ewan C , Leis Jerome A , Fowler Robert A , Pinto Ruxandra , Adhikari Neill KJ , Ferguson Niall D 
Published: February 2011

Abstract
Introduction
Pleural effusions are frequently drained in mechanically ventilated patients but the benefits and risks of this procedure are not well established.

Methods
We performed a literature search of multiple databases (MEDLINE, EMBASE, HEALTHSTAR, CINAHL) up to April 2010 to identify studies reporting clinical or physiological outcomes of mechanically ventilated critically ill patients who underwent drainage of pleural effusions. Studies were adjudicated for inclusion independently and in duplicate. Data on duration of ventilation and other clinical outcomes, oxygenation and lung mechanics, and adverse events were abstracted in duplicate independently.

Results
Nineteen observational studies (N = 1,124) met selection criteria. The mean PaO2:FiO2 ratio improved by 18% (95% confidence interval (CI) 5% to 33%, I
2
= 53.7%, five studies including 118 patients) after effusion drainage. Reported complication rates were low for pneumothorax (20 events in 14 studies including 965 patients; pooled mean 3.4%, 95% CI 1.7 to 6.5%, I
2
= 52.5%) and hemothorax (4 events in 10 studies including 721 patients; pooled mean 1.6%, 95% CI 0.8 to 3.3%, I
2
= 0%). The use of ultrasound guidance (either real-time or for site marking) was not associated with a statistically significant reduction in the risk of pneumothorax (OR = 0.32; 95% CI 0.08 to 1.19). Studies did not report duration of ventilation, length of stay in the intensive care unit or hospital, or mortality.

Conclusions
Drainage of pleural effusions in mechanically ventilated patients appears to improve oxygenation and is safe. We found no data to either support or refute claims of beneficial effects on clinically important outcomes such as duration of ventilation or length of stay.
Interactions between the mat‐forming algaDidymosphenia geminataand its hydrodynamic environment
Authors: Larned Scott T. , Packman Aaron I. , Plew David R. , Vopel Kay 
Published: February 2011

Lay AbstractAlgae require dissolved nutrients to grow, but nutrient concentrations are often very low in unpolluted streams and rivers. The supply of dissolved nutrients to benthic (bottom‐dwelling) algae increases with increasing river flow, but higher flows also produce drag forces that can damage the algae. To persist under high‐flow, low‐nutrient conditions, benthic algae must balance the conflicting requirements of minimal drag (to minimize detachment risks) and maximal exposure to turbulent flow (to maximize nutrient supplies). We explored flow‐algae interactions using the freshwater algaDidymosphenia geminata. D. geminataforms dense mats in swift, nutrient‐poor rivers, and is of particular interest because it is a highly invasive species in North American and New Zealand. To identify the properties that helpD. geminatagrow rapidly and resist detachment, we transplanted cobbles with attachedD. geminatamats from a river to a laboratory flow chamber and measured flow properties above and within the mats. We then removed the mats from the cobbles and repeated the measurements. We found that water flow near the streambed is strongly altered in the presence ofD. geminatamats. The dense, interwovenD. geminatastalks produce high friction and reduce flow fluctuations around and within the mats. The reduction in flow fluctuations around mats may reduce the risk of detachment and help retain dissolved nutrients within mats. We also found thatD. geminatamats increase the roughness of riverbeds relative to bare cobbles, which may increase the rate of nutrient supply from the water to mat surfaces.
Pleomorphic xanthoastrocytoma: MR imaging findings in 19 patients
Authors: Yu Shenping , He Li , Zhuang Xiaozhao , Luo Boning 
Published: February 2011

Background Pleomorphic xanthoastrocytoma (PXA) is a rare and special type of astrocytoma which occurs in childhood and adolescence, and usually with a favorable prognosis. Since its initial description, PXA cases have been reported infrequently in the literature, mostly as single cases or small series. Purpose To review the imaging characteristics of PXA. Material and Methods MR imaging findings of 19 pathologically confirmed PXAs were retrospectively analyzed and correlated with the clinical and pathological features. Results The clinical presentation in 18 patients included: dizziness (8); headache (9); and epilepsy (8). One patient was asymptomatic. On MR imaging, the tumors were located in the brain surface (17), thalamus (1) or deep in the right frontal lobe (1). The tumors were cystic (4), mixed cystic-solid (7), or solid (8) with well-defined (11) or poorly-defined borders (8). Peritumoral edema was marked (8), mild (9) or absent (2). Cystic components of tumors were hypointense on T1- and hyperintense on T2-weighted images whereas the solid components of tumors were hypointense or isointense on T1- and slightly hyperintense on T2-weighted images. There was marked (10), moderate (7) or no (2) contrast enhancement in the solid tumors with surrounding leptomeningeal enhancement (7). The tumors were located in the frontal lobes (8), temporal lobes (7), occipital lobe (1), cerebellum (1), thalamus (1), and sellar region (1). Histologically, 18 tumors were classified as WHO grade 2 comprising of pleomorphic giant cells, spindle cells and foamy cells. One PXA with anaplastic features was composed of pleomorphic polygonal cells and spindle cells, and with high mitotic activity ( ≥5 mitoses per 10 HPF). Immunohistochemical reactions to glial fibrillary acidic protein (GFAP) were positive in all 19 cases. Conclusion The pathological appearances of PXA are distinctive. MR imaging could display the morphologic features exactly, and has important diagnostic value for PXA.
Whole-body diffusion-weighted imaging compared with FDG-PET/CT in staging of lymphoma patients
Authors: Abdulqadhr Goran , Molin Daniel , Åström Gunnar , Suurküla Madis , Johansson Lars , Hagberg Hans , Ahlström Håkan 
Published: February 2011

BackgroundDiffusion-weighted imaging (DWI) has become increasingly valuable in lymph node imaging, yet the clinical utility of this technique in the staging of lymphoma has not been established.PurposeTo compare whole-body DWI with FDG-PET/CT in the staging of lymphoma patients.Material and MethodsThirty-one patients, eight with Hodgkin lymphoma (HL) and 23 with non-Hodgkin's lymphoma (18 aggressive and five indolent) underwent both whole-body DWI, whole-body MRI (T1W and T2W-STIR) and FDG-PET/CT. Lesions on whole-body DWI were only considered positive if they correlated with lesions on T1W and T2W-STIR images. The staging given by each technique was compared, according to the Ann Arbor staging system. Differences in staging were solved using biopsy results, and clinical and CT follow-ups as standard of reference.ResultsThe staging was the same for DWI and FDG-PET/CT in 28 (90.3%) patients and different in three (9.7%). Of the 28 patients with the same staging, 11 had stage IV in both techniques and 17 had stages 0–III. No HL or aggressive non-Hodgkin's lymphoma patients had different staging. Three indolent small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) lymphoma had higher staging with DWI when compared with FDG-PET/CT. One small subcutaneous breast lymphoma was not seen but all other extranodal sites were detected by both techniques.ConclusionWhole-body DWI is a promising technique for staging of both (aggressive and indolent) non-Hodgkin's lymphoma and HL.
Clinical experience of photon counting breast tomosynthesis: comparison with traditional mammography
Authors: Svane Gunilla , Azavedo Edward , Lindman Karin , Urech Mattias , Nilsson Jonas , Weber Niclas , Lindqvist Lars , Ullberg Christer 
Published: February 2011

Background In two-dimensional mammography, a well-known problem is over- and underlying tissue which can either obstruct a lesion or create a false-positive result. Tomosynthesis, with an ability to layer the tissue in the image, has the potential to resolve these issues. Purpose To compare the diagnostic quality, sensitivity and specificity of a single tomosynthesis mammography image and a traditional two-view set of two-dimensional mammograms and to assess the comfort of the two techniques. Material and Methods One hundred and forty-four women, mainly chosen because of suspicious features on standard mammograms (76 malignant), had a single tomosynthesis image taken of one breast using a novel photon counting system. On average, the dose of the tomosynthesis images was 0.63 times that of the two-view images and the compression force during the procedure was halved. The resulting images were viewed by two radiologists and assessed both individually and comparing the two techniques. Results In 56% of the cases the radiologists rated the diagnostic quality of the lesion details higher in the tomosynthesis images than in the conventional images (and in 91% equal or higher), which means there is a statistically significant preference for the tomosynthesis technique. This included the calcifications which were rated as having better quality in 41% of the cases. While sensitivity was slightly higher for traditional mammography the specificity was higher for tomosynthesis. However, neither of these two differences was large enough to be statistically significant. Conclusion The overall accuracy of the two techniques was virtually equal despite the radiologist's very limited experience with tomosynthesis images and vast experience with two-dimensional mammography. As the diagnostic quality of the lesion details in the tomosynthesis images was valued considerably higher this factor should improve with experience. The patients also favored the tomosynthesis examination, rating the comfort of the procedure as much higher than regular mammography which might affect screening attendance.
Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose
Authors: Jeong Dong Wook , Choo Ki Seok , Baik Seung Kug , Kim Yong Woo , Jeon Ung Bae , Kim Jeong Soo , Lim Soo Jin 
Published: February 2011

Background Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and-shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3 ± 6.8) and retrospective CCTA with TCM (77, mean HR: 59.1 ± 9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results There was good agreement for quality scores of coronary artery segment images between the independent reviewers (κ = 0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P > .05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94 ± 0.70 mSv) than for retrospective CCTA with TCM (4.51 ± 1.18 mSv) (P < 0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI] ≥ 25) and non-obese patients (BMI < 25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion Both step-and-shoot and retrospective CCTA with TCM using 128-slice MDCT had similar subjective image quality scores, but step-and-shoot required a lower radiation dose than retrospective CCTA with TCM.
Central venous device-related thrombosis as imaged with MDCT in oncologic patients: prevalence and findings
Authors: Catalano Orlando , de Lutio di Castelguidone Elisabetta , Sandomenico Claudia , Petrillo Mario , Aprea Pasquale , Granata Vincenza , D'Errico Adolfo Gallipoli 
Published: February 2011

Background Venous thrombosis is a common occurrence in cancer patients, developing spontaneously or in combination with indwelling central venous devices (CVD). Purpose To analyze the multidetector CT (MDCT) prevalence, appearance, and significance of catheter-related thoracic venous thrombosis in oncologic patients and to determine the percentage of thrombi identified in the original reports. Material and Methods Five hundred consecutive patients were considered. Inclusion criteria were: presence of a CVD; availability of a contrast-enhanced MDCT; and cancer history. Exclusion criteria were: direct tumor compression/infiltration of the veins; poor image quality; device tip not in the scanned volume; and missing clinical data. Seventeen (3.5%) out of the final 481 patients had a diagnosis of venous thrombosis. Results Factors showing the highest correlation with thrombosis included peripherally-inserted CVD, right brachiocephalic vein tip location, patient performance status 3, metastatic stage disease, ongoing chemotherapy, and longstanding CVD. The highest prevalence was in patients with lymphoma, lung carcinoma, melanoma, and gynecologic malignancies. Eleven out of 17 cases had not been identified in the original report. Conclusion CVD-related thrombosis is not uncommon in cancer patients and can also be observed in outpatients with a good performance status and a non-metastatic disease. Thrombi can be very tiny. Radiologists should be aware of the possibility to identify (or overlook) small thrombi.
MR imaging findings of high-voltage electrical burns in the upper extremities: correlation with angiographic findings
Authors: Lee Gyung Kyu , Suh Kyung Jin , Kang Ik Won , Hwang Dae Hyun , Min Seon Jung , Han You Mie , Choi Min Ho 
Published: February 2011

Background A high-voltage electrical burn is often associated with deep muscle injuries. Hidden, undetected deep muscle injuries have a tendency for progressive tissue necrosis, and this can lead to major amputations or sepsis. MRI has excellent soft tissue contrast and it may aid in differentiating the areas of viable deep muscle from the areas of non-viable deep muscle. Purpose To describe the MR imaging findings of a high-voltage electrical burn in the upper extremity with emphasis on the usefulness of the gadolinium-enhanced MRI and to compare the MR imaging findings with angiography. Material and Methods We retrospectively reviewed the imaging studies of six patients with high-voltage electrical burns who underwent both MRI and angiography at the burn center of our hospital from January 2005 to December 2009. The imaging features were evaluated for the involved locations, the MR signal intensity of the affected muscles, the MR enhancement pattern, the involved arteries and the angiographic findings (classified as normal, sluggish flow, stenosis or occlusion) of the angiography of the upper extremity. We assessed the relationship between the MR imaging findings and the angiographic findings. Results The signal intensities of affected muscles were isointense or of slightly high signal intensity as compared with the adjacent unaffected skeletal muscle on the T1-weighted MR images. Affected muscles showed heterogenous high signal intensity relative to the adjacent unaffected skeletal muscle on the T2-weighted images. The gadolinium-enhanced T1-weighted images showed diffuse inhomogeneous enhancement or peripheral rim enhancement of the affected muscles. The angiographic findings of the arterial injuries showed complete occlusion in three patients, severe stenosis in two patients and sluggish flow in one patient. Of these, the five patients with complete occlusion or severe stenosis on angiography showed non-perfused and non-viable areas of edematous muscle on MRI. On the other hand, one patient with sluggish flow on angiography showed a perfused and viable area of edematous muscle on MRI. Conclusion Gadolinium-enhanced MRI is a useful non-invasive imaging modality to detect the site and extent of hidden, undetected deep muscle injuries in a group of patients with high-voltage electrical burns of the upper extremities.
Study on the Role of Second Phase Particles in Hydrogen Uptake Behavior of Zirconium Alloys
Authors: Yao M. Y. , Wang J. H. , Peng J. C. , Zhou B. X. , Li Q. 
Published: February 2011

Abstract
In an effort to better understand the role of second phase particles (SPPs) in the hydrogen uptake of zirconium alloys, four alloys and four heat treatments for each alloy were chosen to prepare specimens with different SPPs size distributions and area fractions. The hydrogen uptake performance of these specimens was investigated after autoclave testing in 400°C/10.3 MPa steam. Results show that the hydrogen uptake is not always in a strict corresponding relationship with the corrosion resistance among the specimens, but it is closely related to the size, area fraction, and compositions of the SPPs. In the case of Zry-2 and Zry-4, the hydrogen uptake fraction (HUF) increased with increasing size and area fraction of the SPPs. The dependence was more notable for the Zry-2 than the Zry-4. In the case of N36 and N18, the HUF had only a slight variation with the size and area fraction of the SPPs. No matter which heat treatment was employed, the corrosion resistance of the N18 specimens was superior to the N36 specimens, but the HUF of the former was larger than that of the latter. These results clearly demonstrate that the effect of the size and area fraction of SPPs on the hydrogen uptake depends on the SPP compositions. Pressure-composition-temperature and kinetics of absorbing and desorbing hydrogen tests were conducted on Zr(Fe,Cr)2, Zr2(Fe,Ni), Zr(Nb,Fe)2, and β-Nb alloys (which may be found as SPPs in the four zirconium alloys tested) as well as on pure zirconium. Results show that Zr(Nb,Fe)2, Zr2(Fe,Ni), and Zr(Fe,Cr)2 alloys have a stronger reversible ability for hydrogen absorption and desorption than β-Nb alloy and pure zirconium. Based on the testing results, a model correlating the hydrogen uptake performance to the reversible ability of the SPPs to absorb and desorb hydrogen is proposed. The model can successfully explain the results.
Verteilte koordinierte Lastflusssteuerung in elektrischen Energieübertragungsnetzen
Authors: Häger Ulf , Lehnhoff Sebastian , Rehtanz Christian 
Published: February 2011

Zusammenfassung
Energiemarktaktivitäten und die zunehmende Windenergieeinspeisung führen zu einer erhöhten Belastung der elektrischen Energieübertragungsnetze. Um dabei entstehende Netzengpässe zu beheben sind Netzausbaumaßnahmen erforderlich. Neue Leitungen können aufgrund von Umweltauflagen nur zögerlich errichtet werden. Leistungsflussregler (LFR) werden zunehmend eingesetzt, um Engpässe zu entschärfen. Dieser Beitrag stellt einen agentenbasierten verteilten Koordinationsansatz vor, bei dem LFR weitestgehend autonom auf kritische Belastungssituationen reagieren und eine weiträumige Ausregelung ermöglichen.
Characterization of Electrodeposited NiCo Films with Incorporated Ferrite (BaFe12O19) Nano-Particles
Authors: Cojocaru Paula , Pahari Sougata , Magagnin Luca , Dietrich Dagmar , Liebig Andreas , Lampke Thomas 
Published: February 2011

Abstract
NiCo films with incorporated ferrite (BaFe12O19) nano-particles were studied with the motivation of future MEMS application. The microstructure was characterized by SEM, TEM, EBSD and XRD. Magnetic properties were derived from SQUID magnetometry. Two types of layers were electrodeposited distinguished by their microstructure. One type is a pure NiCo nano-grained matrix without particle incorporation; the other is a composite of the nano-grained NiCo matrix with co-deposited nano-sized ferrite particles with a content of about 0.2 wt. %. The soft magnetic matrix dominates the global magnetization behavior expected for NiCo alloys. Despite the low incorpotation rate, the influence of the BaFe12O19 particles in the matrix is apparent in the in-plane measurement.
Precise Analysis of Small Wavenumber Shift of Pyridine on Dilution with H2O and D2O Using RDS Technique
Authors: Mishra Shivangi , Meyer Tobias , Popp Jürgen , Singh Ranjan K. 
Published: February 2011

Abstract
The wavenumber difference (Δν) of the ring breathing mode (ν
1), ring deformation mode (ν
12) and C–H stretching mode (ν
3) of pyridine (Py) dissolved in both H2O and D2O at equal mole fractions of the solute (Py) and the solvent (H2O/D2O) has been determined precisely by using the technique of Raman difference spectroscopy (RDS) in order to analyze the relative shift caused by these two solvents. The spectra of the two systems, for which the difference spectrum is to be generated, were recorded simultaneously and the wavenumber shifts up to almost one hundredth part of the linewidth of a band could be determined precisely. The values of Δν for the three modes as a function of mole fraction are compared with the Δν obtained by the solvation of Py molecule in the media of dielectric constants equal to that of the mixture of Py and H2O/D2O at the experimental mole fractions using DFT and MP2 methods. The variation in Δν with mole fraction seems to be the result of difference of dielectric constants of Py+H2O and Py+D2O at equal mole fraction. The absolute peak position and linewidth of the three modes as a function of mole fraction have been discussed in terms of relevant models, which show the effective role of diffusion and concentration fluctuation in the mixture.