bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes of Supraspinatus Muscle Volume and Fat Fraction After Successful or Failed Arthroscopic Rotator Cuff Repair
Authors: Wieser Karl , Joshy Jethin , Filli Lukas , Kriechling Philipp , Sutter Reto , Fürnstahl Philipp , Valdivieso Paola , Wyss Sabine , Meyer Dominik C. , Flück Martin , Gerber Christian 
Published: September 2019

Background: Muscle atrophy and fatty infiltration are limiting factors for successful rotator cuff (RC) repair. Quantitative data regarding these hallmarks of degenerative muscle changes after RC repair in humans are scarce. By utilizing a new application of the 6-point Dixon magnetic resonance imaging technology, 3-dimensional volume and fat fraction analysis of the whole RC muscle have become possible. Purpose: Quantitative analysis of atrophy and fatty infiltration of the supraspinatus muscle after healed and failed RC tendon-to-bone repair. Study Design: Cohort study; Level of evidence, 3. Methods: Muscle volume and fat fraction were measured preoperatively and at 3 and 12 months postoperatively in 19 failed and 21 healed arthroscopic supraspinatus tendon repairs, with full muscle volume segmentation and magnetic resonance Dixon sequences. Results: In both groups, the muscle volume initially decreased 3 months after RC repair by –3% in intact ( P = .140) and –10% in failed repair ( P = .004) but recovered between 3 and 12 months to 103% ( P = .274) in intact and 92% ( P = .040) in failed repairs when compared with the preoperative volume (difference of change between groups, preoperative to 12 month: P = .013). The supraspinatus muscle’s fat fraction did not significantly change after successful repair (6.5% preoperative, 6.6% after 3 months, and 6.7% after 12 months; all nonsignificant). There was, however, a significant increase from 7.8% to 10.8% at 3 months ( P = .014) and 11.4% at 12 months ( P = .020) after failed repair (difference between groups at 3- and 12-month follow-up: P = .018 and P = .001, respectively). Conclusion: After successful arthroscopic repair, RC tendon tear–induced fatty infiltration can be almost stopped, and muscle atrophy can even be slightly reversed. In case of a failed repair, however, these changes are further pronounced during the first 3 postoperative months but seem to stabilize thereafter.
Rotational and varus–valgus laxity affects kinematics of the normal knee: A cadaveric study
Authors: Wada Keizo , Hamada Daisuke , Takasago Tomoya , Goto Tomohiro , Tonogai Ichiro , Tsuruo Yoshihiro , Sairyo Koichi 
Published: September 2019

Purpose: The aim of this study was to evaluate the relationship between soft tissue laxity and kinematics of the normal knee using a navigation system. Methods: Fifteen cadaveric knees from 11 fresh frozen whole-body specimens were included in this study. The navigation system automatically recorded the rotation angle of the tibia as the internal–external (IE) kinematics and the coronal alignment of the lower limb as the varus–valgus (VV) kinematics. These measurements were made with the joint in maximal extension, at 10° intervals from 0° to 120° of flexion, and at maximal flexion during passive knee motion. For evaluation of laxity, the examiner gently applied maximum manual IE and VV stress to the knee at 0°, 30°, 60°, and 90° of flexion. Results: The measurements showed almost perfect reliability. The mean correlation coefficient between the intraoperative tibial rotation angle and the intermediate angle of IE laxity was 0.82, while that between the coronal alignment of the lower limb and the intermediate angle of the VV laxity was 0.96. There was a statistically significant correlation between kinematics and laxity at all degrees of knee flexion. Conclusion: The present study revealed that the rotation angle of the tibia was correlated to the intermediate angle of IE laxity at 0°, 30°, 60°, and 90° of knee flexion and the coronal alignment of the lower limb also correlated to the intermediate angle of VV laxity. These findings provide important reference data on soft tissue laxity and kinematics of the normal knee.
Survival by Race and Ethnicity in Pediatric and Adolescent Patients With Hodgkin Lymphoma: A Children’s Oncology Group Study
Authors: Kahn Justine M. , Kelly Kara M. , Pei Qinglin , Bush Rizvan , Friedman Debra L. , Keller Frank G. , Bhatia Smita , Henderson Tara O. , Schwartz Cindy L. , Castellino Sharon M. 
Published: September 2019

PURPOSE Population-based studies of children and adolescents with Hodgkin lymphoma (HL) report a survival disadvantage in nonwhite—non-Hispanic black (NHB) and Hispanic—patients. Whether disparities persist after adjustment for clinical and treatment-related variables is unknown. We examined survival by race/ethnicity in children receiving risk-based, response-adapted, combined-modality therapy for HL in contemporary Children’s Oncology Group trials. PATIENTS AND METHODS This pooled analysis used individual-level data from 1,605 patients (younger than age 1 to 21 years) enrolled in phase III trials for low-risk (AHOD0431), intermediate-risk (AHOD0031), and high-risk (AHOD0831) HL from 2002 to 2012. Event-free survival (EFS) and overall survival (OS) were compared between non-Hispanic white (NHW) and nonwhite patients. Cox proportional hazards for survival were estimated for both de novo and relapsed HL, adjusting for demographics, disease characteristics, and therapy. RESULTS At median follow up of 6.9 years, cumulative incidence of relapse was 17%. Unadjusted 5-year EFS and OS were 83% (SE, 1.2%) and 97% (SE, < 1%), respectively. Neither differed by race/ethnicity. In multivariable analyses for OS, nonwhite patients had a 1.88× higher hazard of death (95% CI, 1.1 to 3.3). Five-year postrelapse survival probabilities by race were as follows: NHW, 90%; NHB, 66%; and Hispanic, 80% ( P < .01). Compared with NHW, Hispanic and NHB children had 2.7-fold (95% CI, 1.2 to 6.2) and 3.5-fold (95% CI, 1.5 to 8.2) higher hazard of postrelapse mortality, respectively. CONCLUSION In patients who were treated for de novo HL in contemporary Children’s Oncology Group trials, EFS did not differ by race/ethnicity; however, adjusted OS was significantly worse in nonwhite patients, a finding driven by increased postrelapse mortality in this population. Additional studies examining treatment and survival disparities after relapse are warranted.
Conducting sexualities research: an outline of emergent issues and case studies from ten Wellcome-funded projects
Authors: Kneale Dylan , French Robert , Spandler Helen , Young Ingrid , Purcell Carrie , Boden Zoë , Brown Steven D. , Callwood Dan , Carr Sarah , Dymock Alex , Eastham Rachael , Gabb Jacqui , Henley Josie , Jones Charlotte , McDermott Elizabeth , Mkhwanazi Nolwazi , Ravenhill James , Reavey Paula , Scott Rachel , Smith Clarissa , Smith Matthew , Thomas James , Tingay Karen 
Published: September 2019

This letter seeks to synthesise methodological challenges encountered in a cohort of Wellcome Trust-funded research projects focusing on sexualities and health. The ten Wellcome Trust projects span a diversity of gender and sexual orientations and identities, settings; institutional and non-institutional contexts, lifecourse stages, and explore a range of health-related interventions. As researchers, we originate from a breadth of disciplinary traditions, use a variety of research methods and data sources. Despite this breadth, four common themes are found across the projects: (i) inclusivity, representations and representativeness, (ii) lumping together of diverse groups, (iii) institutions and closed settings (iv) ethical and governance barriers.
Assessment of PrEP eligibility and uptake among at-risk MSM participating in a HIV-1 vaccine feasibility cohort in coastal Kenya
Authors: Wahome Elizabeth , Graham Susan , Thiong’o Alexander , Chirro Oscar , Mohamed Khamisi , Gichuru Evans , Mwambi John , Price Matt , Sanders Eduard J. 
Published: September 2019

Introduction: Pre-exposure prophylaxis (PrEP) is provided free of costs to at-risk populations in Kenya, including men who have sex with men (MSM), but anal intercourse is not an eligibility criterion. We set out to determine PrEP eligibility, uptake and predictors of PrEP uptake among MSM enrolled in an HIV-1 vaccine feasibility cohort in coastal Kenya. Methods: We compared the number of MSM identified as eligible for PrEP from June-December 2017 by Kenyan Ministry of Health (MoH) criteria, which do not include reported anal intercourse, to those identified as eligible by a published MSM cohort-derived HIV-1 risk score (CDHRS). We determined PrEP uptake and assessed factors associated with uptake at first offer among eligible MSM followed up monthly for HIV-1 testing, risk assessment, and risk reduction counselling. Results: Out of 167 MSM assessed for PrEP eligibility, 118 (70.7%) were identified by both MoH and CDHRS eligibility criteria. However, the CDHRS identified 33 (19.8%) more cohort MSM for PrEP eligibility than the MoH criteria, of whom the majority (24 or 72.7%) reported receptive anal intercourse (RAI). Of the 162 MSM eligible for PrEP, 113 (69.7%) accepted PrEP at first offer. Acceptance of PrEP was higher for men reporting RAI (adjusted prevalence ratio [aPR], 1.4; 95% confidence interval [CI], 1.0–1.9), having paid for sex (aPR, 1.3; 95% CI, 1.1–1.6) and group sex (aPR, 1.4; 95% CI, 1.1–1.8), after adjustment for sociodemographic factors. Conclusions: Assessing PrEP eligibility using a CDHRS identified 20% more at-risk MSM for PrEP initiation than when Kenyan MoH criteria were used. Approximately 70% of eligible men accepted PrEP at first offer, suggesting that PrEP is acceptable among at-risk MSM. MSM reporting RAI, group sex, or paying for sex were more likely to accept PrEP, reinforcing the importance of an informed discussion of HIV-1 risk during PrEP counselling.
Audio waves and its loss of energy in puncture needles
Authors: Maldonado Ivan , Illanes Alfredo , Kalmar Marco , Sühn Thomas , Boese Axel , Friebe Michael 
Published: September 2019

Abstract
The location of a puncture needle’s tip and the resistance of tissue against puncture are crucial information for clinicians during a percutaneous procedure. The tip location and needle alignment can be observed by image guidance. Tactile information caused by tissue resistance to rupture, allow clinicians the perception of structural changes during puncture. Nevertheless, this sense is individual and subjective. To improve percutaneous procedures, the implementation of transducers to enhance or complement the senses offer objective feedback to the user. Known approaches are e.g. based on integrated force sensors. However, this is connected to higher device costs, sterilization and certification issues. A recent publication shows the implementation of an audio transducer clipped at the proximal end of the needle. This sensor is capable of acquiring emitted sounds of the distal tiptissue interaction that are transmitted over the needle structure. The interpretation of the measured audio signals is highly depended on the transmission over the needle, the tissue and, the penetration depth. To evaluate the influence of these parameters, this work implements a simplified experimental setup in a controlled environment with a minimum of noise and without micro tremors induced by clinician’s hands. A steel rod simulating a needle is inserted into pork meat of different thickness. A controlled impact covering the needle’s tip mimics tissue contact. The resulting signals are recorded and analyzed for better understanding of the system.
OmniPD: One-Step Person Detection in Top-View Omnidirectional Indoor Scenes
Authors: Yu Jingrui , Seidel Roman , Hirtz Gangolf 
Published: September 2019

Abstract
We propose a one-step person detector for topview omnidirectional indoor scenes based on convolutional neural networks (CNNs). While state of the art person detectors reach competitive results on perspective images, missing CNN architectures as well as training data that follows the distortion of omnidirectional images makes current approaches not applicable to our data. The method predicts bounding boxes of multiple persons directly in omnidirectional images without perspective transformation, which reduces overhead of pre- and post-processing and enables realtime performance. The basic idea is to utilize transfer learning to fine-tune CNNs trained on perspective images with data augmentation techniques for detection in omnidirectional images. We fine-tune two variants of Single Shot MultiBox detectors (SSDs). The first one uses Mobilenet v1 FPN as feature extractor (moSSD). The second one uses ResNet50 v1 FPN (resSSD). Both models are pre-trained on Microsoft Common Objects in Context (COCO) dataset. We fine-tune both models on PASCAL VOC07 and VOC12 datasets, specifically on class person. Random 90-degree rotation and random vertical flipping are used for data augmentation in addition to the methods proposed by original SSD. We reach an average precision (AP) of 67.3%with moSSD and 74.9%with resSSD on the evaluation dataset. To enhance the fine-tuning process, we add a subset of HDA Person dataset and a subset of PIROPO database and reduce the number of perspective images to PASCAL VOC07. The AP rises to 83.2% for moSSD and 86.3% for resSSD, respectively. The average inference speed is 28 ms per image for moSSD and 38 ms per image for resSSD using Nvidia Quadro P6000. Our method is applicable to other CNN-based object detectors and can potentially generalize for detecting other objects in omnidirectional images.
Microphysiological system for heart tissue - going from 2D to 3D culture
Authors: Busek Mathias , Schubert Mario , Guan Kaomei , Sonntag Frank , Schmieder Florian , Marschner Uwe , Richter Andreas 
Published: September 2019

Abstract
Recently, we could demonstrate positive effects of microfluidic cultivation conditions on maturation of cardiomyocytes derived from human induced pluripotent stem cells (iPS-CMs) in a 2D model. However, 3D cell culture models are much closer to physiological conditions. Combined with microfluidics, 3D systems should resemble the in-vivo conditions even better than standard 2D cultivation. For 3D models, two main technical challenges arise, the tissue integration and sufficient nutrient supply for the cells. This work focuses on concepts for the tissue integration based on a modular approach and different manufacturing technologies as well as using an oxygenator in the microfluidic device to provide sufficient oxygen supply for the cells.
An Evaluation of Image Feature Detectors Based on Spatial Density and Temporal Robustness in Microsurgical Image Processing
Authors: Sieler Konstantin , Naber Ady , Nahm Werner 
Published: September 2019

Abstract
Optical image processing is part of many applications used for brain surgeries. Microscope camera, or patient movement, like brain-movement through the pulse or a change in the liquor, can cause the image processing to fail. One option to compensate movement is feature detection and spatial allocation. This allocation is based on image features. The frame wise matched features are used to calculate the transformation matrix. The goal of this project was to evaluate different feature detectors based on spatial density and temporal robustness to reveal the most appropriate feature. The feature detectors included corner-, and blob-detectors and were applied on nine videos. These videos were taken during brain surgery with surgical microscopes and include the RGB channels. The evaluation showed that each detector detected up to 10 features for nine frames. The feature detector KAZE resulted in being the best feature detector in both density and robustness.
Temperature Controlled and Monitored Ex Vivo Lung Perfusion System for Research and Training Purposes
Authors: Pongratz Christina , Ziegle Jens , Boese Axel , Friebe Michael , Linge Helena , Walles Thorsten 
Published: September 2019

Abstract
Ex vivo lung perfusion (EVLP) is a preservation method for donor lungs, which keep lungs viable in a physiological environment outside of a body for a short period of time. EVLP is established clinically for lung transplantation. Experimental applications for EVLP are e.g. lung cancer research or medical device development and testing. For preservation, a lung is ventilated artificially in an organ chamber and perfused antegrade through the pulmonary artery. Here we introduce a thermoregulation system for an experimental EVLP system to be used for translational research approaches as well as for training medical staff. To implement physiological culture conditions that are a prerequisite for lung preservation and tissue homeostasis, a thermoregulation is needed to rewarm the explanted lung tissue (storage temperature 4°C). Technically, the EVLP system must be thermally insulated, so loss of caloric is avoided. For monitoring, temperature sensors are integrated within the lung, in the organ chamber and in the afferent perfusate tube, whereby the measured values determine the thermoregulation. Initial tests using thermal packs (cooled to 4-6°C) placed on a heating mat, as a part of the perfusion circuit, showed that the perfusate temperature falls to 34°C, but restores after approximately 60 minutes (36.5°C), whereby the thermal pack is warmed. With this setup longer perfusion times should be obtained rather than without thermoregulation due to normothermic perfusion of the lung.
Thermomechanical properties of PEGDA in combination with different photo-curable comonomers
Authors: Rekowska Natalia , Arbeiter Daniela , Eickner Thomas , Grabow Niels , Teske Michael , Konasch Jan , Riess Alexander , Mau Robert , Seitz Hermann 
Published: September 2019

Abstract
The technology of pharmaceutical drug delivery systems (DDS) as an individual and adjustable tool for drug administration has been intensively developed in the last years. Additive manufacturing (AM) techniques, such as stereolithography, are a promising approach towards DDS scaffold manufacturing. Stereolithography, by using layerby- photo-polymerisation, creates DDS scaffolds with highly controlled 3D geometry. Combined with inkjet printing it allows a very precise positioning of the drug depot in the basic scaffold and therefore also a better control of the drug release. Furthermore, this hybrid AM technique also allows for the creation of a multi-drug DDS with a several drug depots localized in desired positions within the scaffold. Determination of the scaffold and drug depot material properties is one of the initial steps for such novel DDS development. Basic characteristics, such as stiffness, elasticity or glass transition temperature (Tg), are important for designing and adapting the material for biomedical application. The photosensitive poly(ethylene glycol) diacrylate (PEGDA) can be easily formed into a desired biocompatible scaffold geometry via stereolithography. In this study we have focused on the evaluation of PEGDA (Mn=700 g/mol) as a pure and copolymer system in combination with other acrylates (butanediol diacrylate, pentaerythritol triacrylate) as possible materials for DDS using this novel hybrid AM technique. Irgacure 2959, a biocompatible photoinitiator (PI), was used as a radical starter for photopolymerisation. Samples varying in PI and coacrylate concentration were prepared by conventional photopolymerisation. Physico-chemical analyses of the samples were performed and several parameters, such as stiffness, elongation at break and glass transition temperatures, were determined.
Determination of the hyperelastic material behavior of hydrogel specimens for expandable lens implants
Authors: Martin Heiner , Sahmel Olga , Eickner Thomas , Grabow Niels , Kreiner Christine , Guthoff Rudolf 
Published: September 2019

Abstract
Theoretical and experimental investigations were carried out for development of human lens implants made from hydrogel material. The material properties were measured and implemented in a Finite element model. Though the material is still too stiff for accommodative lenses, the theoretical and experimental foundations for the implant development were established.
Influence of leaflet geometry on hydrodynamic performance of transcatheter aortic valve prostheses
Authors: Sebastian Kaule , Sylvia Pfensig , Stefan Siewert , Pfensig Sylvia , Siewert Stefan , Schmitz Klaus-Peter , Stiehm Michael , Stefanie Kohse , Niels Grabow , Alper Öner 
Published: September 2019

Abstract
The implantation of transcatheter aortic valve prostheses (TAVP) for therapy of aortic valve stenosis shows more and more clinically non-inferiority results compared to surgical valve replacement in intermediate and low risk patients. Commonly clinically used TAVP are manufactured from chemically fixed xenograft leaflet material, e.g. bovine or porcine pericardium. While the clinical use of TAVP currently extends, challenges concerning valve durability and leaflet calcification have to be addressed. In this regard, artificial leaflet materials represent a promising option for a next generation of TAVP. As a first step for the development of TAVP from polymeric nonwoven, the aim of this study was to determine the influence of leaflet geometry on hydrodynamic performance of TAVP prototypes. Based on a parametric model of the valve leaflets, we varied the curvature of the belly line forming the leaflet coaptation area from an initial, quite concave, leaflet geometry with a value of 0.5° to an almost straight geometry for the leaflets with a value 0.15°. Manufacturing of TAVP prototypes was conducted by means of electrospinning technique with a polycarbonate based silicone elastomer. Hydrodynamic characterization according to ISO 5840-3 standards was performed using a pulse duplicator system with a heart rate of 70 BPM, systolic duration of 35%, mean aortic pressure of 100 mmHg and a stroke volume of 96 ml. Cardiac output as well as mean transaortic pressure gradient, closing volume, leakage volume and regurgitation were measured to compare the different leaflet geometries. To summarize, the curvature of the leaflets’ belly has a crucial impact on TAVP hydrodynamics under physiological test conditions. In particular, the opening and closing behavior is strongly influenced by a steeper curvature leading to larger closing volumes and higher regurgitant fractions. Further studies are planned to identify an optimum with respect to leaflet material selection, leaflet geometry and hydrodynamic properties of TAVP.
Low-turbulence displacement-flow for an operating environment
Authors: Heinz Julia , Schäfer Max B. , Stewart Kent W. , Pott Peter P. 
Published: September 2019

Abstract
In developing countries airborne micro-organisms are one of the most common causes of surgical wound infection. In the operating room low-turbulence displacementflow has been shown to reduce the influence of airborne bacteria. However, due to complexity and cost, current systems are not accessible to all potential users. In this paper a low-cost ventilation system is presented that provides lowturbulence displacement-flow over a surgical operating environment. A stand-alone, simple to assemble, mobile airflow system was developed using the principle of speed compensation for laminar airflow. From visual inspection and measurements, the system was seen to generate a continuous downwards displacement of air over the protected area around the situs. The entire system can be assembled quickly with minimal standard tools, making it very suitable for mobile use, such as in disaster areas. Future work is required to achieve the vertical dimension of a laminar flow field required by the DIN 1946-4. Overall, the low-cost and simple system could provide many potential users access to the technology and thus improving hygiene conditions in their operating environment.