57 research outputs found

    Subspecialty surveillance of long-term course of small and moderate muscular ventricular septal defect: heterogenous practices, low yield.

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    BACKGROUND: No expert consensus guides practice for intensity of ongoing pediatric cardiology surveillance of hemodynamically insignificant small and moderate muscular ventricular septal defect (mVSD). Therefore, despite the well-established benign natural history of mVSD, there is potential for widely divergent follow up practices. The purpose of this investigation was to evaluate (1) variations in follow up of mVSD within an academic children\u27s hospital based pediatric cardiology practice, and (2) the frequency of active medical or surgical management resulting from follow up of mVSD. METHODS: We retrospectively reviewed records of 600 patients with isolated mVSD echocardiographically diagnosed between 2006 and 2012. Large mVSD were excluded (n = 4). Patient age, gender, echocardiographic findings, provider, recommendations for follow up, and medical and surgical management were tabulated at initial and follow up visits. Independent associations with follow up recommendations were sought using multivariate analysis. RESULTS: Initial echocardiography showed small single mVSD in 509 (85%), multiple small mVSD in 60 (10%), and small-to-moderate or moderate single mVSD in 31 (5%). The mean age at diagnosis was 15.9 months (0-18.5 years) and 25.7 months (0-18.5 years) at last follow up. There was slight female predominance (56.3%). Fourteen pediatric cardiology providers recommended 316 follow up visits, 259 of which were actually accomplished. There were 37 other unplanned follow up visits. No medical or surgical management changes were associated with any of the follow up visits. The proportion of patients for whom follow up was advised varied among providers from 11 to 100%. Independent associations with recommendation for follow up were limited to the identity and clinical volume of the provider, age of the patient, and the presence of multiple, small-to-moderate, or moderate mVSD. CONCLUSIONS: In this large series of moderate or smaller mVSD, pediatric cardiology follow up was commonly recommended but resulted in no active medical or surgical management. Major provider based inconsistency in intensity of follow up of mVSD was identified, but is difficult to justify

    Petrography and geochemistry of the enriched basaltic shergottite Northwest Africa 2975

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    We present a study of the petrology and geochemistry of basaltic shergottite Northwest Africa 2975 (NWA 2975). NWA 2975 is a medium-grained basalt with subophitic to granular texture. Electron microprobe (EMP) analyses show two distinct pyroxene compositional trends and patchy compositional zoning patterns distinct from those observed in other meteorites such as Shergotty or QUE 94201. As no bulk sample was available to us for whole rock measurements, we characterized the fusion crust and its variability by secondary ion mass spectrometer (SIMS) measurements and laser ablation inductively coupled plasma spectroscopy (LA-ICP-MS) analyses as a best-available proxy for the bulk rock composition. The fusion crust major element composition is comparable to the bulk composition of other enriched basaltic shergottites, placing NWA 2975 within that sample group. The CI-normalized REE (rare earth element) patterns are flat and also parallel to those of other enriched basaltic shergottites. Merrillite is the major REE carrier and has a flat REE pattern with slight depletion of Eu, parallel to REE patterns of merrillites from other basaltic shergottites. The oxidation state of NWA 2975 calculated from Fe-Ti oxide pairs is NNO-1.86, close to the QFM buffer. NWA 2975 represents a sample from the oxidized and enriched shergottite group, and our measurements and constraints on its origin are consistent with the hypothesis of two distinct Martian mantle reservoirs: a reduced, LREE-depleted reservoir and an oxidized, LREE-enriched reservoir. Stishovite, possibly seifertite, and dense SiO_2 glass were also identified in the meteorite, allowing us to infer that NWA 2975 experienced a realistic shock pressure of ~30 GPa

    Mortality-related resource utilization in the inpatient care of hypoplastic left heart syndrome.

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    BACKGROUND: Quantifying resource utilization in the inpatient care of congenital heart diease is clinically relevant. Our purpose is to measure the investment of inpatient care resources to achieve survival in hypoplastic left heart syndrome (HLHS), and to determine how much of that investment occurs in hospitalizations that have a fatal outcome, the mortality-related resource utilization fraction (MRRUF). METHODS: A collaborative administrative database, the Pediatric Health Information System (PHIS) containing data for 43 children\u27s hospitals, was queried by primary diagnosis for HLHS admissions of patients ≤21 years old during 2004-2013. Institution, patient age, inpatient deaths, billed charges (BC) and length of stay (LOS) were recorded. RESULTS: In all, 11,122 HLHS admissions were identified which account for total LOS of 277,027 inpatient-days and $3,928,794,660 in BC. There were 1145 inpatient deaths (10.3%). LOS was greater among inpatient deaths than among patients discharged alive (median 17 vs. 12, p \u3c 0.0001). BC were greater among inpatient deaths than among patients discharged alive (median 4.09 × 10(5) vs. 1.63 × 10(5), p \u3c 0.0001). 16% of all LOS and 21% of all BC were accrued by patients who did not survive their hospitalization. These proportions showed no significant change year-by-year. The highest volume institutions had lower mortality rates, but there was no relation between institutional volume and the MRRUF. CONCLUSIONS: These data should alert providers and consumers that current practices often result in major resource expenditure for inpatient care of HLHS that does not result in survival to hospital dismissal. They highlight the need for data-driven critical review of standard practices to identify patterns of care associated with success, and to modify approaches objectively

    The progress of pulmonary artery denervation

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    Pulmonary arterial hypertension (PAH) is a chronic pulmonary vascular disease characterized by increased pulmonary arterial pressure and pulmonary arterioles remodeling. Some studies have discovered the relationship between sympathetic nerves (SNs) and pathogenesis of PAH. This review is aimed to illustrate the location and components of SNs in the pulmonary artery, along with different methods and effects of pulmonary artery denervation (PADN). Studies have shown that the SNs distributed mainly around the main pulmonary artery (MPA) and pulmonary artery (PA) bifurcation. And the SNs could be destroyed by three ways: the chemical way, the surgical way and the catheter-based way. PADN can significantly decrease pulmonary arterial pressure rapidly, improve hemodynamic varieties, and then palliate PAH. PADN has been recognized as a prospective and effective therapy for PAH patients, especially for those with medication-refractory PAH. However, further enlarged clinical studies are needed to confirm accurate distribution of SNs in the pulmonary artery and the efficacy of PADN

    Furan-containing double tetraoxa[7]helicene and its radical cation

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    An unprecedented furan-based double oxa[7]helicene 1 was achieved, featuring a stable twisted conformation with π-overlap at both helical ends. The excellent conformational stability allowed for optical resolution of 1, which provided a pair of enantiomers exhibiting pronounced mirror-imaged circular dichroism and circularly polarized luminescence activity. The radical cation of 1 was obtained by chemical oxidation as evidenced by UV-Vis-NIR absorption, electron paramagnetic resonance spectroscopy and in situ spectroelectrochemistry. The present work is the starting point for the investigation of open-shell oxahelicenes

    Three-dimensional printing models in congenital heart disease education for medical students: a controlled comparative study

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    Abstract Background This study sought to assess, using subjective (self-assessment) and objective (MCQ) methods, the efficacy of using heart models with ventricular septal defect lesions produced with three-dimensional printing technology in a congenital heart disease curriculum for medical students. Methods Three computed tomography datasets of three subtypes of ventricular septal defects (perimembranous, subarterial and muscular, one for each) were obtained and processed for building into and printing out 3D models. Then a total of 63 medical students in one class were randomly allocated to two groups (32 students in the experimental, and 31 the control). The two groups participated in a seminar with or without a 3D heart model, respectively. Assessment of this curriculum was carried out using Likert-type questionnaires as well as an objective multiple choice question test assessing both knowledge acquisition, and structural conceptualization. Open-ended questions were also provided for getting advice and suggestion on 3D model utilization in CHD education. Results With these 3D models, feedback shown in the questionnaires from students in experimental group was significantly more positive than their classmates in the control. And the test results also showed a significant difference in structural conceptualization in favor of the experimental group. Conclusion It is effective to use heart models created using current 3D printing technology for congenital heart disease education. It stimulates students’ interest in congenital heart disease and improves the outcomes of medical education

    Optimal selection and effect evaluation of re-fracturing intervals in shale gas horizontal wells

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    The monitoring results of production logging show that almost one third of perforation clusters produce no or less gas after volumetric fracturing is initially applied in shale gas reservoirs. Besides, the production decline after the commissioning is commonly faster. In this paper, a fracture network prediction model and a fracturing well productivity prediction model were established based on microseismic interpretation data and hydraulic fracture network propagation results. After petrophysics, microseism, production performance were taken into consideration comprehensively, shale re-fracturing development potential evaluation index (RDPEI) was proposed. Then, a re-fracturing design and evaluation method was developed and targeted interval selection and evaluation was realized and applied on site. And the following research results were obtained. First, due to the heterogeneity of natural fractures, hydraulic fracture networks are more different, so an obvious “dead gas zone” can be easily formed and its re-fracturing potential is high. Second, the initial hydraulic fracture network is more affected by natural fractures. The main part of a fracture network propagates along the direction of maximum horizontal major stress, the fractures in regional stimulated intervals propagate in the form of double wing, and the length of a liquid swept fracture network is 52–70% of seismic interpretation result. Third, the RDPEI model avoids the limitations of single factor analysis and realizes the quantitative prediction on three types of indexes of recoverability, compressibility and re-fracturing. Fourth, re-fracturing of the case well is remarkable in stimulation effect. Its shale gas productivity is increased by 38.9%, and its cumulative gas production in one year is increased by 62.5%. In conclusion, re-fracturing is an effective and feasible method for improving the single well ultimate recovery reserves of shale gas. This method provides a theoretical and technical support for the selection and effect evaluation of re-fracturing intervals in shale-gas horizontal wells. Keywords: Shale gas, Re-fracturing, Productivity, Prediction, Fracture network propagation, Microseismic, Production decline, Single-well ultimate recoverable reserve
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