Aerospace Medicine and Biology: A cumulative index to the 1974 issues of a continuing bibliography

This publication is a cumulative index to the abstracts contained in supplements 125 through 136 of Aerospace Medicine and Biology: A Continuing Bibliography. It includes three indexes--subject, personal author, and corporate source

On Improving Generalization of CNN-Based Image Classification with Delineation Maps Using the CORF Push-Pull Inhibition Operator

Deployed image classification pipelines are typically dependent on the images captured in real-world environments. This means that images might be affected by different sources of perturbations (e.g. sensor noise in low-light environments). The main challenge arises by the fact that image quality directly impacts the reliability and consistency of classification tasks. This challenge has, hence, attracted wide interest within the computer vision communities. We propose a transformation step that attempts to enhance the generalization ability of CNN models in the presence of unseen noise in the test set. Concretely, the delineation maps of given images are determined using the CORF push-pull inhibition operator. Such an operation transforms an input image into a space that is more robust to noise before being processed by a CNN. We evaluated our approach on the Fashion MNIST data set with an AlexNet model. It turned out that the proposed CORF-augmented pipeline achieved comparable results on noise-free images to those of a conventional AlexNet classification model without CORF delineation maps, but it consistently achieved significantly superior performance on test images perturbed with different levels of Gaussian and uniform noise

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device

Radiographic Assessment of Hip Disease in Children with Cerebral Palsy: Development of a Core Measurement Set and Analysis of an Artificial Intelligence System

Cerebral palsy is the most common physical disability during childhood. Cerebral palsy related hip disease is caused by an imbalance of muscle forces, resulting in progressive migration of the hip to complete dislocation. This can decrease function and quality of life. The prevention of hip dislocation is possible if detected early. Therefore, surveillance programmes have been set up to monitor children with cerebral palsy enabling clinicians to intervene early and improve outcomes. Currently, hip disease is assessed by analysing pelvic radiographs with various geometric measurements. This time-consuming task is undertaken frequently when monitoring a child with cerebral palsy. This thesis aimed to identify the key radiographic parameters used by clinicians (the core measurement set), and then build an artificial intelligence system to automate the calculation of this core measurement set. A systematic review was conducted identifying a comprehensive list of previously reported measurements from studies measuring radiographic outcomes in cerebral palsy children with hip pathologies. Fifteen measurements were identified from the systematic review, of which Reimers’ migration percentage was the most commonly reported. These measurements were used to perform a two-round Delphi study among orthopaedic surgeons and physiotherapists. Participants rated the importance of each measurement using a nine-point Likert scale (‘not important’ to critically important’). After the two rounds of the Delphi process, Reimers’ migration percentage was included in the core measurement set. Following the final consensus meeting, the femoral head-shaft angle was also included. The anteroposterior pelvic radiographs of 1650 children were then used to build an artificial intelligence system integrating the core measurement set, in collaboration with engineers from the University of Manchester. The newly developed artificial intelligence system was assessed by comparing its ability to calculate measurements and outline the pelvis and femur on a radiograph. The reliability of the dataset used to train the model was also analysed. The proposed artificial intelligence model achieved a ‘good to excellent’ inter-observer reliability across 450 radiographs when comparing its ability to calculate Reimers’ migration percentage to five clinicians. Its ability to outline the pelvis and proximal femur was ‘adequate’ with the better performance observed in the pelvis than the femur. The reliability of the training dataset used to teach the artificial intelligence model was ‘good’ to ‘very good’. Artificial intelligence systems are feasible solutions to optimise the efficiency of hip radiograph analysis in cerebral palsy. Studies are warranted to include the core measurement set as a minimum when reporting on hip disease in cerebral palsy. Future research should investigate the feasibility of implementing a risk score to predict the likelihood of hip displacement

[¹⁸F]fluorination of biorelevant arylboronic acid pinacol ester scaffolds synthesized by convergence techniques

Aim: The development of small molecules through convergent multicomponent reactions (MCR) has been boosted during the last decade due to the ability to synthesize, virtually without any side-products, numerous small drug-like molecules with several degrees of structural diversity.(1) The association of positron emission tomography (PET) labeling techniques in line with the “one-pot” development of biologically active compounds has the potential to become relevant not only for the evaluation and characterization of those MCR products through molecular imaging, but also to increase the library of radiotracers available. Therefore, since the [18F]fluorination of arylboronic acid pinacol ester derivatives tolerates electron-poor and electro-rich arenes and various functional groups,(2) the main goal of this research work was to achieve the 18F-radiolabeling of several different molecules synthesized through MCR. Materials and Methods: [18F]Fluorination of boronic acid pinacol esters was first extensively optimized using a benzaldehyde derivative in relation to the ideal amount of Cu(II) catalyst and precursor to be used, as well as the reaction solvent. Radiochemical conversion (RCC) yields were assessed by TLC-SG. The optimized radiolabeling conditions were subsequently applied to several structurally different MCR scaffolds comprising biologically relevant pharmacophores (e.g. β-lactam, morpholine, tetrazole, oxazole) that were synthesized to specifically contain a boronic acid pinacol ester group. Results: Radiolabeling with fluorine-18 was achieved with volumes (800 μl) and activities (≤ 2 GBq) compatible with most radiochemistry techniques and modules. In summary, an increase in the quantities of precursor or Cu(II) catalyst lead to higher conversion yields. An optimal amount of precursor (0.06 mmol) and Cu(OTf)2(py)4 (0.04 mmol) was defined for further reactions, with DMA being a preferential solvent over DMF. RCC yields from 15% to 76%, depending on the scaffold, were reproducibly achieved. Interestingly, it was noticed that the structure of the scaffolds, beyond the arylboronic acid, exerts some influence in the final RCC, with electron-withdrawing groups in the para position apparently enhancing the radiolabeling yield. Conclusion: The developed method with high RCC and reproducibility has the potential to be applied in line with MCR and also has a possibility to be incorporated in a later stage of this convergent “one-pot” synthesis strategy. Further studies are currently ongoing to apply this radiolabeling concept to fluorine-containing approved drugs whose boronic acid pinacol ester precursors can be synthesized through MCR (e.g. atorvastatin)