Optical Tomography of Chemical Elements Synthesized in Type Ia Supernovae.

We report the discovery of optical emission from the nonradiative shocked ejecta of three young type Ia supernova remnants (SNRs): SNR 0519-69.0, SNR 0509-67.5, and N103B. Deep integral field spectroscopic observations reveal broad and spatially resolved [Fe XIV] 5303 Å emission. The width of the broad line reveals, for the first time, the reverse shock speeds. For two of the remnants we can constrain the underlying supernova explosions with evolutionary models. SNR 0519-69.0 is well explained by a standard near-Chandrasekhar mass explosion, whereas for SNR 0509-67.5 our analysis suggests an energetic sub-Chandrasekhar mass explosion. With [S XII], [Fe IX], and [Fe XV] also detected, we can uniquely visualize different layers of the explosion. We refer to this new analysis technique as "supernova remnant tomography".

Letter to the Editor: Thrombocytopenia After Sutureless Aortic Valve Implantation: Does It Really Matter?

Despite the limited clinical relevance of thrombocytopenia after bioprosthetic aortic valve replacement (AVR), the postoperative depletion of platelet count continues to attract the attention of many authors. The development of thrombocytopenia has been evaluated either in patients receiving a sutureless bioprosthesis (1,2) or in those undergoing transcatheter aortic valve implantation, where cardiopulmonary bypass bears little or no relation to this phenomenon (3). Recently, Sánchez et al. (1) have published their findings on this topic, but their limited experience with the devices used makes their study of doubtful interest. Over three years, 27 patients were implanted with a sutureless bioprosthetic valve and were compared with 50 patients receiving a stented aortic valve. No risk factors that may have predisposed to platelet dysfunction were described in either group.Mortality and number of units of transfused red blood cells also seems to be extremely high for a patient population undergoing elective isolated AVR: it is not clear whether bleeding complications occurred in any patients and re-thoracotomy could not be performed, or whether more liberal transfusion protocols were used. In addition, platelet transfusions in patients from the sutureless group could represent a bias that renders the comparison of postoperative mean platelet volume and platelet distribution width between groups unreliable. It would have been more appropriate to consider postoperative echocardiographic findings because, in case of suboptimal placement of the prosthesis, paravalvular leakage may cause severe hemolysis and thrombocytopenia. At present, clinical data can be derived from other case series (4). At our Center, over a six-year period, AVR was performed using a sutureless, stentless, or stented bioprosthesis in 432, 193, and 180 patients, respectively, with all devices being supplied by the same manufacturer. Perioperative trends in platelet count after sutureless AVR did not show progression towards thrombocytopenia as occurs after stentless AVR (5), but compared favourably with conventional stented AVR (Fig. 1), where platelet depletion has no clinical relevance. Figure 1: Perioperative trends in platelet count after aorticvalve replacement with the sutureless Perceval, stentlessSolo, and stented Crown bioprosthetic valves.References1. Sánchez E, Corrales JA, Fantidis P, Tarhini IS, Khan I, Pineda T, González JR. Thrombocytopenia after aortic valve replacement with Perceval S sutureless bioprosthesis. J Heart Valve Dis 2016;25:75-812. Jiritano F, Cristodoro L, Malta E, Mastroroberto P. Thrombocytopenia after sutureless aortic valve implantation: Comparison between Intuity and Perceval bioprostheses. J Thorac Cardiovasc Surg 2016;152:1631-16333. McCabe JM, Huang PH, Riedl LA, et al. Incidence and implications of idiopathic thrombocytopenia following transcatheter aortic valve replacement with the Edwards Sapien® valves: A single center experience. Catheter Cardiovasc Interv 2014;83:633-6414. Santarpino G, Fischlein T, Pfeiffer S. A word of caution is needed before uttering a word of caution: Thrombocytopenia and sutureless valves. Heart Surg Forum 2016;19:E1695. Pozzoli A, De Maat GE, Hillege HL, Boogaard JJ, Natour E, Mariani MA. Severe thrombocytopenia and its clinical impact after implant of the stentless Freedom Solo bioprosthesis. Ann Thorac Surg 2013;96:1581-1586.

[Aortic valve replacement in the elderly]. / Aortenklappenersatz im Alter.

The treatment of severe symptomatic aortic valve stenosis by conventional aortic valve replacement (AVR) or by transcatheter aortic valve implantation (TAVI) has a good perinterventional prognosis even for patients of advanced age. Having a heart team select the best management strategies based on current guidelines for each individual patient is essential for success. Especially in elderly and increasingly multimorbid patients with sometimes severe preconditions, the detection of functional deficits is relevant not only for the mortality but also for perioperative and postoperative complications as well as the functional outcome. Various methods of geriatric assessment are important supplements to standard risk scores. The aim is to implement targeted interventions to minimize the risk factors and to improve the prognosis for elderly patients. The aim of this article is to provide an overview of the current therapy options for aortic valve replacement and to summarize current aspects of treatment options for elderly patients.

Describing readmissions to an Ebola case management centre (CMC), Sierra Leone, 2014.

Case management centres (CMCs) are part of the outbreak control plan for Ebola virus disease (EVD). A CMC in Sierra Leone had 33% (138/419) of primary admissions discharged as EVD negative (not a case). Fifteen of these were readmitted within 21 days, nine of which were EVD positive. All readmissions had contact with an Ebola case in the community in the previous 21 days indicating that the infection was likely acquired outside the CMC.

In-silico analysis of hemodynamic indicators in idealized stented coronary arteries for varying stent indentation.

In this work, we investigate the effects of stent indentation on hemodynamic indicators in stented coronary arteries. Our aim is to assess in-silico risk factors for in-stent restenosis (ISR) and thrombosis after stent implantation. The proposed model is applied to an idealized artery with Xience V stent for four indentation percentages and three mesh refinements. We analyze the patterns of hemodynamic indicators arising from different stent indentations and propose an analysis of time-averaged WSS (TAWSS), topological shear variation index (TSVI), oscillatory shear index (OSI), and relative residence time (RRT). We observe that higher indentations display higher frequency of critically low TAWSS, high TSVI, and non-physiological OSI and RRT. Furthermore, an appropriate mesh refinement is needed for accurate representation of hemodynamics in the stent vicinity. The results suggest that disturbed hemodynamics could play a role in the correlation between high indentation and ISR.

[CEUS as a tool to uncover an unusual cause of obstructive jaundice]. / KM-verstärkter Ultraschall zur Erkennung der seltenen Ursache eines obstruktiven Ikterus.

Aneurysms within the visceral arteries are rare. Among these, aneurysms of the splenic artery occur most frequently followed by aneurysms of the hepatic arteries. An early diagnosis is easily missed and almost all patients become symptomatic with an acute rupture associated with high mortality. Here we demonstrate the case of a 76-year-old patient who presented with acute upper abdominal pain accompanied by a single episode of vomiting and pyrexia of 39 °C. Laboratory results presented the picture of an obstructive jaundice without evidence for accompanying pancreatitis. Inflammatory markers were within normal limits at onset, but increased dramatically within the next few days. An acute calculous cholecystitis was diagnosed on abdominal ultrasound whereas gastroscopy revealed no relevant changes. Computed tomography was suspicious for pancreatitis of the head with obstruction of the bile duct. Choledocholithiasis was ruled out by ERCP, but symptoms persisted despite papillotomy. Due to raising inflammatory markers and an ongoing impairment of the patients condition, an abdominal CT scan was repeated which revealed the suspicion of a ruptured aneurysm of the common hepatic artery. At the time of transferral we were able to confirm the diagnosis by contrast-enhanced ultrasound and angiography. The patient was immediately forwarded to surgery due to lack of satisfactory endovascular procedures. In summary, the patient suffered from a ruptured spurial aneurysm of the right gastric artery thereby obstructing the common bile duct. Beside CT scans and angiography, this case documents a pivotal role for contrast-enhanced ultrasound in the work-up of visceral artery aneurysms.

Development of In Vitro Endothelialised Stents - Review.

Endovascular treatment is prevalent as a primary treatment for coronary and peripheral arterial diseases. Although the introduction of drug-eluting stents (DES) dramatically reduced the risk of in-stent restenosis, stent thrombosis persists as an issue. Notwithstanding improvements in newer generation DES, they are yet to address the urgent clinical need to abolish the late stent complications that result from in-stent restenosis and are associated with late thrombus formation. These often lead to acute coronary syndromes with high mortality in coronary artery disease and acute limb ischemia with a high risk of limb amputation in peripheral arterial disease. Recently, a significant amount of research has focused on alternative solutions to improve stent biocompatibility by using tissue engineering. There are two types of tissue engineering endothelialisation methods: in vitro and in vivo. To date, commercially available in vivo endothelialised stents have failed to demonstrate antithrombotic or anti-stenosis efficacy in clinical trials. In contrast, the in vitro endothelialisation methods exhibit the advantage of monitoring cell type and growth prior to implantation, enabling better quality control. The present review discusses tissue-engineered candidate stents constructed by distinct in vitro endothelialisation approaches, with a particular focus on fabrication processes, including cell source selection, stent material composition, stent surface modifications, efficacy and safety evidence from in vitro and in vivo studies, and future directions.

Finite element evaluation of artery damage in deployment of polymeric stent with pre- and post-dilation.

Using finite element method, this paper evaluates damage in an arterial wall and plaque caused by percutaneous coronary intervention. Hyperelastic damage models, calibrated with experimental results, are used to describe stress-stretch responses of arterial layers and plaque; these models are capable to simulate softening behaviour of the tissue due to damage. Abaqus CAE is employed to create the finite element models for the artery wall (with media and adventitia layers), a symmetric uniform plaque, a bioresorbable polymeric stent and a tri-folded expansion balloon. The effect of percutaneous coronary intervention on vessel damage is investigated by simulating the processes of vessel pre-dilation, stent deployment and post-stenting dilation. Energy dissipation density is used to assess the extent of damage in the tissue. Softening of the plaque and the artery, due to the pre-dilation-induced damage, can facilitate the subsequent stent deployment process. The plaque and the artery experienced heterogeneous damage behaviour after the stent deployment, caused by non-uniform deformation. The post-stenting dilation was effective to achieve a full expansion of the stent, but caused additional damage to the artery. The continuous and discontinuous damage models yielded similar results in the percutaneous coronary intervention simulations, while the incorporation of plaque rupture affected the simulated outcomes of stent deployment. The computational evaluation of the artery damage can be potentially used to assess the risk of in-stent restenosis after percutaneous coronary intervention.

Patient-specific modelling of stent overlap: Lumen gain, tissue damage and in-stent restenosis.

This paper investigates the effects of multiple stents, with and without overlap, on the outcome of stent deployment in a patient-specific coronary artery using the finite element method. Specifically, the objective of this study is to reveal the effect of stent overlap on lumen gain, tissue damage and in-stent restenosis in percutaneous coronary intervention. Based on intravital optical coherency tomography imaging, three-dimensional model of a specific patient's coronary artery was developed, with two constituent layers (media and adventitia) and plaque, using Mimics. Hyperelastic models with damage, verified against experimental results, were used to describe stress-stretch responses of arterial layers and plaque. Abaqus CAE was used to create the models for Resolute Integrity™ drug-eluting stents and tri-folded expansion balloons. The results showed that lumen gain was improved by the overlapping stents than a single stent after deployment; however, damage to the media layer was greater, promoting a higher rate of in-stent restenosis. Meanwhile, the lumen gain achieved with the non-overlapping stents was smaller than that with the overlapping ones, due to an increased recoiling effect. Also, non-overlapping stents induced more tissue damage and higher rate of in-stent restenosis than overlapping stents. With respect to long-term clinical outcomes, the study recommended the use of a single stent where possible or multiple stents with minimal overlaps to treat long or angulated lesions.

Delay of transfer from the intensive care unit: a prospective observational analysis on economic effects of delayed in-house transfer.

BACKGROUND: Intensive care unit (ICU) capacity is a scant and precious resource in hospitals. Therefore, an optimal occupancy rate as well as detailed occupation planning is of great importance. Most literature deals with admission to the ICU, while only few discuss discharge from the ICU. Specifically, a delay of transfer from the ICU can cause a shortness of beds, jeopardize urgent patient treatment and lead to a decrease in treatment quality as well as economic downsides. This study examined the incidence, costs and reasons for delayed discharge from the ICU and analyzed the influence of the department the patient was admitted to. METHODS: Over the course of 12 months, the discharges of all 1643 patients of two surgical intensive care units of a large academic medical center were analyzed. Delay in minutes and reasons were recorded and translated into financial figures. A univariate logistic regression model was developed to evaluate the impact of length of stay at the ICU, age, gender, subspecialty and specific ICU on the delay of transfer. In a next step, significant factors of the univariate logistic regression were incorporated into a multivariate regression model. RESULTS: In 326 out of 1312 patients ready for discharge (24.8%), the transfer to the floor was delayed. Time of delay for all patients added up to a total of 265,691 min in 1 year. The application of the internal cost allocation, in which 1 min corresponds to 0.75 Euro cents, led to costs of 199,268 Euros (~ $240,000) for the study period. In 91.7% of the cases, the reason for the delay was the lack of an available or appropriate bed on the regular ward. Multivariate regression analysis revealed that the type of department the patient is admitted to poses a significantly influencing factor for delayed discharge from the ICU. CONCLUSION: Delay in discharge from the ICU is a common problem of economic relevance. The main reason is a lack of appropriate floor beds. Patients from certain specific departments are at a higher risk to be discharged with delay. A solution to this problem lies in the focus on the downstream units. A proper use of the scarce resources is to be pursued because of ethical as well as economic reasons in an increasingly aging population.

[Assessment of aortic stenosis after aortic valve replacement: comparative evaluation of dual-source CT and echocardiography]. / Quantitative Evaluation der Aortenklappenöffnungsfläche mit der Dual-Source-CT und Korrelation mit der 2D-Echokardiografie: Initiale Ergebnisse.

PURPOSE: To prospectively evaluate whether planimetric measurements of aortic valve area (AVA) with dual-source computed tomography (DSCT) correlate with measurements obtained by echocardiography and to correlate the amount of calcification of the aortic valve with AVA in a group of patients after aortic valve replacement. MATERIALS AND METHOD: 23 patients underwent dual-source computed tomography (DSCT) of the heart (Somatom Definition, Siemens Medical Solutions, Forchheim, Germany), without heart rate control (heart rate 52-113 beats/minute). All patients had undergone aortic valve replacement (homografts, mean time after surgery: 7+/-3 years). The AVA of the transplanted aortic valve graft was measured planimetrically by means of DSCT and compared with echocardiography as a standard of reference, to exclude post-surgical restenosis of the valve. Maximum AVA in systole planimetrically measured with CT was compared with calculated AVA values determined with the continuity equation, using transvalvular pressure gradients. The amount of calcification of the aortic valve was quantified and correlated (Spearman's R) with the AVA. To assess intra- and inter-reader reproducibility, the DCST data was re-analyzed by two readers 4 weeks after the initial review. RESULTS: All DSCT datasets were of diagnostic image quality concerning valve depiction. The mean AVA as measured by DSCT was 2.7+/-0.9 cm (2) compared to 1.8+/-0.5 cm (2) by echocardiography (p<0.05). The planimetric evaluation of the CT data as compared to results of echocardiography showed a significant correlation of the results (Pearson's correlation coefficient R=0.78, p<0.001). Intra- and inter-reader reproducibility was good with intra-class correlation coefficients of 0.86 and 0.81, respectively (p<0.001). There was a significant negative correlation between the amount of aortic valve calcification and AVA as measured by echocardiography (R= -0.42; p<0.05) and as measured by DSCT (R= -0.67; p=0.001). CONCLUSION: First experience indicates that DSCT is able to assess aortic valve opening area with high image quality and good intra- and inter-reader reproducibility in subjects after aortic valve replacement. The negative correlation between AVA and the amount of aortic valve calcification suggests that calcification is a possible risk factor for restenosis in subjects with aortic valve replacement.

[Femoral neck fractures in patients over 50 years old]. / Les fractures du col du fémur après 50 ans.

INTRODUCTION: Despite many papers and instructional course lectures, therapeutic guidelines are not clearly defined about treatment of femoral neck fractures. The aim of this multicentric French symposium was to prospectively study the results of current therapeutic options in order to propose scientifically proven options. MATERIAL AND METHODS: Three prospective studies were carried out in order to answer to these questions: (1) is it possible with anatomical reduction and stable fixation to lower the non union and osteonecrosis rate? (2) is functional treatment of Garden 1 fractures successful in more than 65 years patients? (3) what criteria are useful to choose the kind of arthroplasty for more than 65 years patients? RESULTS: For the 64 patients between 50 and 65 years old included in the first study, 44 ORIF and 17 prostheses were performed. No open reduction was performed in this series despite a 34% malreduction rate. The risk for displacement after functional treatment of Garden 1 fractures is 31%. For patients over 65 years old, almost fractures are treated in this series by an arthroplasty. The one-year mortality rate after displaced femoral neck fracture was 17%. Functional results were better in total hip prosthesis group than in bipolar or unipolar group. Non cemented stems were not safer than cemented ones in frail patients. DISCUSSION AND CONCLUSIONS: For young patients, ORIF should be the treatment of choice: the initial displacement and its effects on the femoral head vascularisation, the quality of reduction and fixation are the two most significant factors for good outcome. For Garden 1, fractures in patients 65 years old or more, it is proposed to performed an internal fixation despite in two thirds of the cases, it should be unnecessary because non identification of predictive factors of failure. For patients over 65 years old, the type of arthroplasty to perform in displaced fractures is to be chosen according to the preoperative mobility and comorbidities. Because of acetabular erosion with long-term follow-up, it is clearly indicated to perform total hip replacement for patients with life expectancy of 10 years or more. For frail patients, unipolar arthroplasty is the best option. The place for bipolar or uncemented implants is not yet well-defined and more prospective trials are needed. In this multicentric study, results appear quite different in terms of mortality, or functional status. These differences seem to be related to technical choice, geriatric care, nutritional consideration or surgical organisation, all factors that may be of major importance for prognostic.

[Diagnostic performance of contrast-enhanced MR angiography of the aortoiliac arteries with the blood pool agent Vasovist: initial results in comparison to intra-arterial DSA]. / Diagnostische Wertigkeit der kontrastverstärkten Magnetresonanzangiografie der Beckenstrombahn mit dem intravaskulären Kontrastmittel Vasovist: Erste klinische Erfahrungen im Vergleich zur i. a. DSA.

PURPOSE: To prospectively assess the accuracy of contrast-enhanced MR angiography of the aortoiliac arteries using the blood pool agent Vasovist compared to unenhanced time-of-flight MRA. Conventional digital subtraction angiography served as the standard of reference. MATERIALS AND METHODS: Twenty-nine patients with suspected or known peripheral arterial occlusive disease (PAOD) were examined by means of contrast-enhanced aortoiliac MR angiography using a dosage of 0.03 mmol/kg bodyweight Vasovist. Unenhanced two-dimensional time-of-flight (TOF) MRA of the same anatomic region was performed immediately prior to injection of the contrast agent. This study was approved by the local Institutional Review Board and informed consent was obtained from all subjects. Both contrast-enhanced and unenhanced MRA images were compared to conventional angiography with respect to the presence of vascular stenosis. Three independent, blinded readers evaluated vessel stenosis and occlusion on the basis of DSA and MR angiographic image readings. Sensitivity, specificity, accuracy, and the area under the receiver operating characteristic curve were analyzed. Correlations between readers of conventional angiograms were calculated and compared to the MR results. RESULTS: In the case of pooled readings, unenhanced TOF MR angiography had a sensitivity of 42.6 %, a specificity of 78.4 % and an accuracy of 74.9 % for detection of clinically significant (>50 %) stenosis. Vasovist-enhanced MRA showed significant improvement in sensitivity (83.3 %), specificity (88.8 %) and accuracy (88.3 %) compared to TOF MRA (p<0.01). The areas under the receiver operating characteristic curve for quantitative measurements increased significantly (p<0.01) in the case of Vasovist-enhanced MRA compared to TOF MRA. All readers found fewer images uninterpretable with Vasovist enhancement and the agreement regarding stenosis location and degree of stenosis between MR angiography and DSA improved substantially after Vasovist administration compared to the noncontrast examination. CONCLUSION: MR angiography using the blood pool agent Vasovist is a feasible and minimally invasive alternative to DSA and provides angiograms of the aortoiliac region with high sensitivity, specificity, and diagnostic accuracy.

[Rapid total body fat measurement by magnetic resonance imaging: quantification and topography]. / Schnelle Ganzkörperfettmessung mittels MRT: Quantifizierung und Topografie.

PURPOSE: To evaluate a rapid and comprehensive MR protocol based on a T1-weighted sequence in conjunction with a rolling table platform for the quantification of total body fat. MATERIALS AND METHODS: 11 healthy volunteers and 50 patients were included in the study. MR data was acquired on a 1.5-T system (Siemens Magnetom Sonata). An axial T1-weighted flash 2D sequence (TR 101, TE 4.7, FA 70, FOV 50 cm, 205 x 256 matrix, slice thickness: 10 mm, 10 mm interslice gap) was used for data acquisition. Patients were placed in a supine position on a rolling table platform capable of acquiring multiple consecutive data sets by pulling the patient through the isocenter of the magnet. Data sets extending from the upper to lower extremities were collected. The images were analyzed with respect to the amount of intraabdominal, subcutaneous and total abdominal fat by semi-automated image segmentation software that employs a contour-following algorithm. RESULTS: The obtained MR images were able to be evaluated for all volunteers and patients. Excellent correlation was found between whole body MRI results in volunteers with DEXA (r (2) = 0.95) and bioimpedance (r (2) = 0.89) measurements, while the correlation coefficient was 0.66 between MRI and BMI, indicating only moderate reliability of the BMI method. Variations in patients with respect to the amount of total, subcutaneous, and intraabdominal adipose tissue was not related to standard anthropometric measurements and metabolic lipid profiles (r (2) = 0,001 to 0.48). The results showed that there was a significant variation in intraabdominal adipose tissue which could not be predicted from the total body fat (r (2) = 0.14) or subcutaneous adipose tissue (r (2) = 0.04). Although no significant differences in BMI could be found between females and males (p = 0.26), females showed significantly higher total and subcutaneous abdominal adipose tissue (p < 0.05). CONCLUSION: This MR protocol can be used for the rapid and non-invasive quantification of body fat. The missing relationship between serum lipids and body fat masses suggests that the latter is an additional and independent hazard factor. Variations in body fat distribution, e. g. relationship between subcutaneous and intraabdominal fat, can be comprehensively assessed.

[Tibial diaphysis fractures below a total knee prosthesis]. / Fractures diaphysaires du tibia sous une prothèse totale du genou.

The fractures of the tibial diaphysis below a total knee prosthesis are a surgical challenge and intra medullary nailing seems impossible. For the SOFCOT 2005 symposium on peri prosthetic fractures we reviewed our files: six cases were found and analysed. These fractures are rare: 5 cases from the symposium (out of 96 periprosthetic fractures at the knee) are reported plus a more recent one. They were observed in elderly (over 70) women except two cases of rheumatoid arthritis. All the patients were osteoporotic either due to aging or to a long duration corticosteroid treatment. All happened after minor trauma (fall from height). The fractures were classified as SOFCOT C1: letter C means diaphyseal below the prosthetic keel or stem, number 1 means: a well-fixed implant. Intra medullary nailing became the preferred treatment over time. A good analysis of the preoperative lateral radiograph of the knee shows if there is room enough for the nail between the prosthetic keel and the anterior tibial tuberosity, the nail remaining outside the synovium. Bone healed as usually for this type of fracture without impairment of knee or ankle function. However the patients became more dependent. In some instances, an unusual type of fracture may need an unusual treatment.

[Fence grafting for acetabular reconstruction with a cementless cup]. / Greffe en palissade pour recentrage acétabulaire dans les reprises par implant sans ciment.

Acetabular reconstruction is difficult after loss of bone stock and socket remodeling. Several techniques have been proposed ranging from a metal backing to allografting. We propose fence grafting. After explantation, the acetabulum is carefully cleaned of all interface tissue and precisely measured. If the vertical diameter is clearly greater than the anteroposterior diameter, a tricortical graft is harvested from the iliac crest and modeled to perfectly fit between the anterioinferior iliac spine and the residual posterior wall as well as the fundus medially. One or two oblique screws are inserted for stabilization. Any superior bone loss is filled by bone substitute (without mechanical value). The acetabulum is then reamed from the obturator foramen sparing the anterior and posterior columns. Residual bony defects are filled with cancellous bone. A hemispheric cup is then press fit and maintained with two or three screws. We performed this procedure in eight patients with SO.F.C.O.T. stage III acetabular loosening with segmentary bone loss and an oval acetabular cavity. Clinical follow-up was more than four years. The Postel-Merle-d'Aubigné score improved from 9.8 to 15.7 on average. Radiographically, there were no implant mobilization or migration and no circumferential lucent lines were observed. A nearly anatomic position was achieved in all cases except two (technical imperfection). At more than one-year follow-up, the grafts could not be distinguished from adjacent bone. For us, high-positioned or jumbo cups do not offer a satisfactory reconstruction option. There is a risk of compression with allografts from a head bank. We have not used the cemented metal-backed solution nor impacted grafts. The major drawback with fence grafting is the iliac harvesting (possible residual limping because of the extensive disinsertion of the gluteus medius. The reliable acetabular reconstruction is the major advantage. This technique is not simply an acetabular block widened laterally but it decreases the vertical dimension. This is a reliable but minute technique which allows true long-lasting reconstruction of the acetabulum.

First experience with the new Sorin Crown PRT bioprosthetic aortic valve: early postoperative outcome and hemodynamic performance in 90 patients.

AIM: The Crown PRT (The Phospholipid Reduction Treatment) is a new stent bovine bioprosthesis for aortic valve replacement (AVR). Aim of this paper is to report the postoperative clinical and hemodynamic results after ninety consecutive implants. METHODS: After receiving CE mark in July 2014, two European university centers implanted the new Crown PRT (Sorin Group, Burnaby, Canada) for the first time. Up to now, ninety patients underwent aortic valve replacement, in isolated or combined procedures, for aortic stenosis or insufficiency. Intraoperative transesophageal echocardiogram was used to assess the prosthesis's function. In hospital outcomes and echocardiographic parameters were recorded. RESULTS: Age and Log Euroscore were 71.8±7.9 years and 10.2%±4.5 respectively. In-hospital mortality for isolated AVR was 0%; one patient died after a multiple procedure (overall 30-days mortality 1.1%). No adverse device effects were recorded. Intensive Care Unit stay was 2±5.8 days. At discharge, echocardiogram showed no paravalvular leaks and normal postoperative gradients. CONCLUSION: Our starting results showed that the Crown PRT is safe and reliable, with excellent hemodynamic performance. Further clinical results with a larger population and long term follow-up are needed to assess the versatility and the durability of this new device.

Ring-opening polymerization of lactones in the presence of hydroxyapatite.

The ring-opening polymerization of epsilon-caprolactone, delta-valerolactone (VL) and D,L-lactide, respectively, in the presence of different proportions of hydroxyapatite (HA) was catalyzed by stannous (II)octoate (SnOct2) at 130 degrees C and resulted in composites. The lactones were almost completely converted to the polymers within a reaction time of 70 up to 240 min. The number-average molecular weights Mn as determined by size exclusion chromatography decreased with increasing content of HA. The initiating efficiency of HA as calculated from the difference of the polymerization degrees P. obtained with and without HA turned out to be relatively low with ca. 11 to 0.5% for 1 to 80 wt% HA, respectively. For the polymerization of VL, the initiating efficiency of HA was on the average threefold higher. The quantitative proof of non-extractable polymer on HA by means of thermogravimetric analysis, fourier transform infrared spectroscopy with photoacoustic detection and differential scanning calorimetry confirmed the initiating efficiency of HA as mentioned above. This poly(lactone) can be debound from HA by treatment with aqueous HCl. Hence it is assumed to be ionically bound.

Multiple-rotor-cycle 2D PASS experiments with applications to (207)Pb NMR spectroscopy.

Thetwo-dimensional phase-adjusted spinning sidebands (2D PASS) experiment is a useful technique for simplifying magic-angle spinning (MAS) NMR spectra that contain overlapping or complicated spinning sideband manifolds. The pulse sequence separates spinning sidebands by their order in a two-dimensional experiment. The result is an isotropic/anisotropic correlation experiment, in which a sheared projection of the 2D spectrum effectively yields an isotropic spectrum with no sidebands. The original 2D PASS experiment works best at lower MAS speeds (1-5 kHz). At higher spinning speeds (8-12 kHz) the experiment requires higher RF power levels so that the pulses do not overlap. In the case of nuclei such as (207)Pb, a large chemical shift anisotropy often yields too many spinning sidebands to be handled by a reasonable 2D PASS experiment unless higher spinning speeds are used. Performing the experiment at these speeds requires fewer 2D rows and a correspondingly shorter experimental time. Therefore, we have implemented PASS pulse sequences that occupy multiple MAS rotor cycles, thereby avoiding pulse overlap. These multiple-rotor-cycle 2D PASS sequences are intended for use in high-speed MAS situations such as those required by (207)Pb. A version of the multiple-rotor-cycle 2D PASS sequence that uses composite pulses to suppress spectral artifacts is also presented. These sequences are demonstrated on (207)Pb test samples, including lead zirconate, a perovskite-phase compound that is representative of a large class of interesting materials.

High-frequency components in the alpha band and memory performance.

We tested the hypothesis that alpha band power is correlated with memory performance. For a sample of 68 subjects, the ongoing electroencephalogram (EEG) was analyzed during three experimental conditions: eyes closed (EC), eyes open (EO), and memorizing words. The results show that the upper alpha band of approximately 10-12 Hz is related to memory performance. Only within this frequency range did we obtain significant positive correlations between memory performance and EEG power. A comparison of power spectra showed that within the range of the upper alpha band good performers had significantly greater normalized percent power than bad memory performers. In contrast to condition EC, the obtained relationship between upper alpha power and memory performance was particularly strong during EO and memorizing words.