363 research outputs found
Image Segmentation from RGBD Images by 3D Point Cloud Attributes and High-Level Features
In this paper, an approach is developed for segmenting an image into major surfaces and potential objects using RGBD images and 3D point cloud data retrieved from a Kinect sensor. In the proposed segmentation algorithm, depth and RGB data are mapped together. Color, texture, XYZ world coordinates, and normal-, surface-, and graph-based segmentation index features are then generated for each pixel point. These attributes are used to cluster similar points together and segment the image. The inclusion of new depth-related features provided improved segmentation performance over RGB-only algorithms by resolving illumination and occlusion problems that cannot be handled using graph-based segmentation algorithms, as well as accurately identifying pixels associated with the main structure components of rooms (walls, ceilings, floors). Since each segment is a potential object or structure, the output of this algorithm is intended to be used for object recognition. The algorithm has been tested on commercial building images and results show the usability of the algorithm in real time applications
DECORAS: detection and characterization of radio-astronomical sources using deep learning
We present DECORAS, a deep learning based approach to detect both point and
extended sources from Very Long Baseline Interferometry (VLBI) observations.
Our approach is based on an encoder-decoder neural network architecture that
uses a low number of convolutional layers to provide a scalable solution for
source detection. In addition, DECORAS performs source characterization in
terms of the position, effective radius and peak brightness of the detected
sources. We have trained and tested the network with images that are based on
realistic Very Long Baseline Array (VLBA) observations at 20 cm. Also, these
images have not gone through any prior de-convolution step and are directly
related to the visibility data via a Fourier transform. We find that the source
catalog generated by DECORAS has a better overall completeness and purity, when
compared to a traditional source detection algorithm. DECORAS is complete at
the 7.5 level, and has an almost factor of two improvement in
reliability at 5.5. We find that DECORAS can recover the position of
the detected sources to within 0.61 0.69 mas, and the effective radius
and peak surface brightness are recovered to within 20 per cent for 98 and 94
per cent of the sources, respectively. Overall, we find that DECORAS provides a
reliable source detection and characterization solution for future wide-field
VLBI surveys.Comment: submitted to MNRA
Serum and Cellular Biologic Tumor Markers in Testicular Cancer
During the past two decades, a dramatic improvement has been made in the treatment of testicular germ cell tumor. This progress has been dueto finding more efficacious systemic chemotherapeutic agents and the availability of specific and sensitive biologic tumor markers to detect early recurrence and monitor the therapy. In this review, i will update my 15 years of experience in establishing and utilization of these serum and cell markers in testicular cancer
The ROAM/EORTC-1308 trial: Radiation versus Observation following surgical resection of Atypical Meningioma: study protocol for a randomised controlled trial
BACKGROUND
Atypical meningiomas are an intermediate grade brain tumour with a recurrence rate of 39-58 %. It is not known whether early adjuvant radiotherapy reduces the risk of tumour recurrence and whether the potential side-effects are justified. An alternative management strategy is to perform active monitoring with magnetic resonance imaging (MRI) and to treat at recurrence. There are no randomised controlled trials comparing these two approaches.
METHODS/DESIGN
A total of 190 patients will be recruited from neurosurgical/neuro-oncology centres across the United Kingdom, Ireland and mainland Europe. Adult patients undergoing gross total resection of intracranial atypical meningioma are eligible. Patients with multiple meningioma, optic nerve sheath meningioma, previous intracranial tumour, previous cranial radiotherapy and neurofibromatosis will be excluded. Informed consent will be obtained from patients. This is a two-stage trial (both stages will run in parallel): Stage 1 (qualitative study) is designed to maximise patient and clinician acceptability, thereby optimising recruitment and retention. Patients wishing to continue will proceed to randomisation. Stage 2 (randomisation) patients will be randomised to receive either early adjuvant radiotherapy for 6 weeks (60 Gy in 30 fractions) or active monitoring. The primary outcome measure is time to MRI evidence of tumour recurrence (progression-free survival (PFS)). Secondary outcome measures include assessing the toxicity of the radiotherapy, the quality of life, neurocognitive function, time to second line treatment, time to death (overall survival (OS)) and incremental cost per quality-adjusted life year (QALY) gained.
DISCUSSION
ROAM/EORTC-1308 is the first multi-centre randomised controlled trial designed to determine whether early adjuvant radiotherapy reduces the risk of tumour recurrence following complete surgical resection of atypical meningioma. The results of this study will be used to inform current neurosurgery and neuro-oncology practice worldwide.
TRIAL REGISTRATION
ISRCTN71502099 on 19 May 2014
Surgical aortic valve replacement in the era of transcatheter aortic valve implantation: a review of the UK national database
Objectives To date the reported outcomes of surgical aortic valve replacement (SAVR) are mainly in the settings of trials comparing it with evolving transcatheter aortic valve implantation. We set out to examine characteristics and outcomes in people who underwent SAVR reflecting a national cohort and therefore âreal-worldâ practice.
Design Retrospective analysis of prospectively collected data of consecutive people who underwent SAVR with or without coronary artery bypass graft (CABG) surgery between April 2013 and March 2018 in the UK. This included elective, urgent and emergency operations. Participantsâ demographics, preoperative risk factors, operative data, in-hospital mortality, postoperative complications and effect of the addition of CABG to SAVR were analysed.
Setting 27 (90%) tertiary cardiac surgical centres in the UK submitted their data for analysis.
Participants 31â277 people with AVR were identified. 19â670 (62.9%) had only SAVR and 11â607 (37.1%) had AVR+CABG.
Results In-hospital mortality for isolated SAVR was 1.9% (95% CI 1.6% to 2.1%) and was 2.4% for AVR+CABG. Mortality by age category for SAVR only were: 75 years=2.2%. For SAVR+CABG these were; 2.2%, 1.8% and 3.1%. For different categories of EuroSCORE, mortality for SAVR in low risk people was 1.3%, in intermediate risk 1% and for high risk 3.9%. 74.3% of the operations were elective, 24% urgent and 1.7% emergency/salvage. The incidences of resternotomy for bleeding and stroke were 3.9% and 1.1%, respectively. Multivariable analyses provided no evidence that concomitant CABG influenced outcome. However, urgency of the operation, poor ventricular function, higher EuroSCORE and longer cross clamp and cardiopulmonary bypass times adversely affected outcomes.
Conclusions Surgical SAVR±CABG has low mortality risk and a low level of complications in the UK in people of all ages and risk factors. These results should inform consideration of treatment options in people with aortic valve disease
Cerebral activations during viewing of food stimuli in adult patients with acquired structural hypothalamic damage: A functional neuroimaging study
BACKGROUND/OBJECTIVES: Obesity is common following hypothalamic damage due to tumours. Homeostatic and non-homeostatic brain centres control appetite and energy balance but their interaction in the presence of hypothalamic damage remains unknown. We hypothesized that abnormal appetite in obese patients with hypothalamic damage results from aberrant brain processing of food stimuli. We sought to establish differences in activation of brain food motivation and reward neurocircuitry in patients with hypothalamic obesity (HO) compared with patients with hypothalamic damage whose weight had remained stable. SUBJECTS/METHODS: In a cross-sectional study at a University Clinical Research Centre, we studied 9 patients with HO, 10 age-matched obese controls, 7 patients who remained weight-stable following hypothalamic insult (HWS) and 10 non-obese controls. Functional magnetic resonance imaging was performed in the fasted state, 1âh and 3âh after a test meal, while subjects were presented with images of high-calorie foods, low-calorie foods and non-food objects. Insulin, glucagon-like peptide-1, Peptide YY and ghrelin were measured throughout the experiment, and appetite ratings were recorded. RESULTS: Mean neural activation in the posterior insula and lingual gyrus (brain areas linked to food motivation and reward value of food) in HWS were significantly lower than in the other three groups (P=0.001). A significant negative correlation was found between insulin levels and posterior insula activation (P=0.002). CONCLUSIONS: Neural pathways associated with food motivation and reward-related behaviour, and the influence of insulin on their activation may be involved in the pathophysiology of HO.International Journal of Obesity advance online publicatio
End-Tagging of Ultra-Short Antimicrobial Peptides by W/F Stretches to Facilitate Bacterial Killing
BACKGROUND: Due to increasing resistance development among bacteria, antimicrobial peptides (AMPs), are receiving increased attention. Ideally, AMP should display high bactericidal potency, but low toxicity against (human) eukaryotic cells. Additionally, short and proteolytically stable AMPs are desired to maximize bioavailability and therapeutic versatility. METHODOLOGY AND PRINCIPAL FINDINGS: A facile approach is demonstrated for reaching high potency of ultra-short antimicrobal peptides through end-tagging with W and F stretches. Focusing on a peptide derived from kininogen, KNKGKKNGKH (KNK10) and truncations thereof, end-tagging resulted in enhanced bactericidal effect against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Through end-tagging, potency and salt resistance could be maintained down to 4-7 amino acids in the hydrophilic template peptide. Although tagging resulted in increased eukaryotic cell permeabilization at low ionic strength, the latter was insignificant at physiological ionic strength and in the presence of serum. Quantitatively, the most potent peptides investigated displayed bactericidal effects comparable to, or in excess of, that of the benchmark antimicrobial peptide LL-37. The higher bactericidal potency of the tagged peptides correlated to a higher degree of binding to bacteria, and resulting bacterial wall rupture. Analogously, tagging enhanced peptide-induced rupture of liposomes, particularly anionic ones. Additionally, end-tagging facilitated binding to bacterial lipopolysaccharide, both effects probably contributing to the selectivity displayed by these peptides between bacteria and eukaryotic cells. Importantly, W-tagging resulted in peptides with maintained stability against proteolytic degradation by human leukocyte elastase, as well as staphylococcal aureolysin and V8 proteinase. The biological relevance of these findings was demonstrated ex vivo for pig skin infected by S. aureus and E. coli. CONCLUSIONS/SIGNIFICANCE: End-tagging by hydrophobic amino acid stretches may be employed to enhance bactericidal potency also of ultra-short AMPs at maintained limited toxicity. The approach is of general applicability, and facilitates straightforward synthesis of hydrophobically modified AMPs without the need for post-peptide synthesis modifications
The outcomes measured and reported in intracranial meningioma clinical trials: A systematic review
Background
Meningioma clinical trials have assessed interventions including surgery, radiotherapy, and pharmacotherapy. However, agreement does not exist on what, how, and when outcomes of interest should be measured. To do so would allow comparative analysis of similar trials. This systematic review aimed to summarize the outcomes measured and reported in meningioma clinical trials.
Methods
Systematic literature and trial registry searches were performed to identify published and ongoing intracranial meningioma clinical trials (PubMed, Embase, Medline, CINAHL via EBSCO, and Web of Science, completed January 22, 2022). Reported outcomes were extracted verbatim, along with an associated definition and method of measurement if provided. Verbatim outcomes were deduplicated and the resulting unique outcomes were grouped under standardized outcome terms. These were classified using the taxonomy proposed by the âCore Outcome Measures in Effectiveness Trialsâ (COMET) initiative.
Results
Thirty published articles and 18 ongoing studies were included, describing 47 unique clinical trials: Phase 2 nâ
=â
33, phase 3 nâ
=â
14. Common interventions included: Surgery nâ
=â
13, radiotherapy nâ
=â
8, and pharmacotherapy nâ
=â
20. In total, 659 verbatim outcomes were reported, of which 84 were defined. Following de-duplication, 415 unique verbatim outcomes remained and were grouped into 115 standardized outcome terms. These were classified using the COMET taxonomy into 29 outcome domains and 5 core areas.
Conclusions
Outcome measurement across meningioma clinical trials is heterogeneous. The standardized outcome terms identified will be prioritized through an eDelphi survey and consensus meeting of key stakeholders (including patients), in order to develop a core outcome set for use in future meningioma clinical trials
The outcomes measured and reported in observational studies of incidental and untreated intracranial meningioma: A systematic review
Background
The clinical management of patients with incidental intracranial meningioma varies markedly and is often based on clinician choice and observational data. Heterogeneous outcome measurement has likely hampered knowledge progress by preventing comparative analysis of similar cohorts of patients. This systematic review aimed to summarize the outcomes measured and reported in observational studies.
Methods
A systematic literature search was performed to identify published full texts describing active monitoring of adult cohorts with incidental and untreated intracranial meningioma (PubMed, EMBASE, MEDLINE, and CINAHL via EBSCO, completed January 24, 2022). Reported outcomes were extracted verbatim, along with an associated definition and method of measurement if provided. Verbatim outcomes were de-duplicated and the resulting unique outcomes were grouped under standardized outcome terms. These were classified using the taxonomy proposed by the âCore Outcome Measures in Effectiveness Trialsâ (COMET) initiative.
Results
Thirty-three published articles and 1 ongoing study were included describing 32 unique studies: study designs were retrospective nâ
=â
27 and prospective nâ
=â
5. In total, 268 verbatim outcomes were reported, of which 77 were defined. Following de-duplication, 178 unique verbatim outcomes remained and were grouped into 53 standardized outcome terms. These were classified using the COMET taxonomy into 9 outcome domains and 3 core areas.
Conclusions
Outcome measurement across observational studies of incidental and untreated intracranial meningioma is heterogeneous. The standardized outcome terms identified will be prioritized through an eDelphi survey and consensus meeting of key stakeholders (including patients), in order to develop a Core Outcome Set for use in future observational studies
The ROAM/EORTC-1308 trial: Radiation versus Observation following surgical resection of Atypical Meningioma: study protocol for a randomised controlled trial
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