481 research outputs found
Kruchość chorych kierowanych na operacje kardiochirurgiczne — badanie pilotażowe
Introduction. Frailty has been recently approved in many surgical fields as the acknowledged preoperative predictor of adverse postoperative complications. Several methods are available to assess frailty assessment which focus on different patient-related data. The aims of the study were: 1) to verify whether frailty may predict early postoperative complications in cardiac surgery; and 2) to investigate the agreement between objective and subjective assessment of frailty.
Material and methods. This prospective study included 54 consecutive patients (32 men; median age 75 years) hospitalized between December 2015 and February 2016. Frailty was assessed using the Edmonton Frail Scale (EFS, subjective tool) and the Modified Frailty Index (MFI, objective tool). Complications were evaluated based on medical records.
Results. The median EFS was 6 (IQR 5–7) points. Frailty was observed in 15% and vulnerability in 49% of subjects. The median MFI was 0.45 (IQR 0.36–0.56). We found a weak correlation between frailty and the length of hospital stay (EFS: r = 0.22; P = 0.1; MFI: r = 0.324; P = 0.02). Neither tools could predict the occurrence of postoperative complications (EFS: AUROC = 0.602; 95% CI 0.459–0.732; P = 0.2; MFI: AUROC = 0.532; 95% CI 0.389–0.670; P = 0.2). We found no correlation between EFS and MFI (r = 0.05, P = 0.7).
Conclusions. Although many elderly cardiac surgical patients are at risk of frailty, none of the evaluated methods could predict postoperative complications. Available diagnostic tools to assess frailty cannot be used interchangeably. Subjective assessment (by a patient) should be verified by objective evaluation (by a treating physician) and conclusions should be drawn based on the overall clinical picture
Application of near infrared sensors to preconcentration of hydrothermally-formed copper ore
Article© 2015. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Near infrared sensors can be a very useful technique for the qualitative analysis of complex ores, and thus could be useful for the preconcentration of ores. In this paper, individual particles of hydrothermally-formed copper ore sampled from a mine in the Los Pozos mining district, northern Chile, were classified as product, middling and waste based on their near infrared response. The classification of copper bearing minerals (product) from gangue (waste) was considered for vibration combination bands at longer wavelengths from 2000 to 2400 nm. This region exhibits characteristic features for carbonates and hydroxyl gangue bearing minerals. The near infrared features at 1400 and 1900 nm were not considered favourable for classification and subsequent discrimination because they can be influenced by moisture and other environmental factors and are easily suppressed by iron-rich minerals. Two near infrared preconcentration strategies were applied for particle discrimination. Results indicate that targeting only the calcite (carbonate) dominated particles for discrimination as waste provided the best option for preconcentration. The near infrared discrimination analysis correlates well with mineralogical (QEMSCAN® and XRD) and elemental (XRF) data classification. The results indicate that near infrared spectroscopy is a suitable preconcentration method for supergene copper ore
Seasonal variability of meio- and macrobenthic standing stocks and diversity in an Arctic fjord (Adventfjorden, Spitsbergen)
Strong environmental seasonality is a basic feature of the Arctic system, still there are few published records of the seasonal variability of the Arctic marine biota. This study examined the year-round seasonal changes of soft bottom macro- and meiobenthic standing stocks and diversity on a station located in an Arctic fjord (Adventfjorden, Spitsbergen). The seasonality observed in benthic biota was related to the pelagic processes, primarily the seasonal fluxes of organic and inorganic particles. The highest abundance, biomass and richness of benthic fauna occurred in the spring after the phytoplankton bloom. During the summer, when a high load of glacial mineral material was transported to the fiord, the number of both meio- and macrobenthic individuals decreased remarkably. The strong inorganic sedimentation in summer was accompanied by a decline in macrobenthic species richness, but had no effects on evenness. Redundancy analysis (RDA) pointed to granulometric composition of sediments (depended on mineral sedimentation) and organic fluxes as factors best related to meio- and macrobenthic taxonomic composition, but no clear seasonal trend could be observed on the nMDS plots based on meiobenthic higher taxa or macrobenthic species abundances in the samples. This study addresses the possible effects of changes in the winter ice cover on the fjordic benthic systems because it was performed in a year with no ice cover on the fjord
Mutations in the KRAS gene in ovarian tumors.
RAS genes are the most frequently mutated oncogenes detected in human cancer. In this study we analyzed the presence of mutations at codon 12 of the KRAS gene in 78 women with ovarian tumor, including 64 invasive ovarian cancers and 14 borderline ovarian tumors, using an RFLP-PCR technique and we evaluated whether such alterations were associated with the selected clinicopathological parameters of the patients. KRAS codon 12 gene mutations were found in 6,2% of ovarian cancer tissue and in 14,3% of the borderline ovarian tumor. KRAS mutations were found with a significantly higher frequency in mucinous and borderline tumors compared to serous tumors (
ActiveStereoNet: End-to-End Self-Supervised Learning for Active Stereo Systems
In this paper we present ActiveStereoNet, the first deep learning solution
for active stereo systems. Due to the lack of ground truth, our method is fully
self-supervised, yet it produces precise depth with a subpixel precision of
of a pixel; it does not suffer from the common over-smoothing issues;
it preserves the edges; and it explicitly handles occlusions. We introduce a
novel reconstruction loss that is more robust to noise and texture-less
patches, and is invariant to illumination changes. The proposed loss is
optimized using a window-based cost aggregation with an adaptive support weight
scheme. This cost aggregation is edge-preserving and smooths the loss function,
which is key to allow the network to reach compelling results. Finally we show
how the task of predicting invalid regions, such as occlusions, can be trained
end-to-end without ground-truth. This component is crucial to reduce blur and
particularly improves predictions along depth discontinuities. Extensive
quantitatively and qualitatively evaluations on real and synthetic data
demonstrate state of the art results in many challenging scenes.Comment: Accepted by ECCV2018, Oral Presentation, Main paper + Supplementary
Material
Shallow-Water Scavengers of Polar Night and Day – An Arctic Time-Lapse Photography Study
Until recently, polar night constituted truly a “mare incognitum” of our times. Yet, the first records from this very little-explored period showcased a surprisingly rich and active ecosystem. This investigation aims to reveal the level of scavenger activity during both Arctic polar night and day. It compares the shallow-water scavenging fauna observed during two contrasting seasons (winter vs. summer) in a high Arctic fjord (Kongsfjorden, 79° N, Spitsbergen, Svalbard Archipelago). In each of January and July 2015, two different bait types – Atlantic cod (Gadus morhua) and a bird carcass (chicken meat) were deployed at a depth of 12 m. Fauna were monitored remotely using time-lapse cameras equipped with bait traps, with photographs taken every 15 min over a period of 4 days. Thirty taxa were recorded at baits, dominated by lysianassid amphipods (Onisimus sp. 88%, Anonyx sp. 2%, but only during winter), and buccinid gastropods (B. undatum 5%, B. glaciale 1%, Buccinum sp. 3%, in both seasons). In most cases, buccinids were the first animals to appear at bait. The total number of recorded taxa, mean species richness per sampling unit, total abundance and associations among taxa were higher, on average, in winter than in summer deployments, while Pielou’s evenness index showed the opposite pattern. Scavenger assemblages differed significantly between the two seasons and also in response to the two different bait types, with seasonal effects being strongest. Contrary to expectations, bait consumption rates differed very little between the two seasons, being slow in general and only slightly faster in summer (0.05 g of cod bait consumed in 1 min) compared to winter (0.04 g min–1), yielding novel insights into ecological interactions and functions in shallow marine ecosystems during Arctic polar nights
Characterising the linearity of an optically controlled photoconductive microwave switch
The linearity response of a photoconductive switch
on microstrip line is presented at 2GHz. A silicon switch is
exposed to incident signal power of up to 1W and controlled via
illumination with a range of optical intensities at a wavelength of
980nm in order to characterise the linearity in terms of harmonic
content. Reported single tone output third order intercept (TOI)
was measured as 63dBm under 200mW of optical incident light.
The study presents photoconductive switches as a promising
alternative to conventional microwave switches in high power
applications
Mutations of the KRAS oncogene in endometrial hyperplasia and carcinoma.
The aim of this study was to examine the prevalence and clinicopathological significance of KRAS point mutation in endometrial hyperplasia and carcinoma. We analysed KRAS in 11 cases of complex atypical hyperplasia and in 49 endometrial carcinomas using polymerase chain reaction associated with restriction fragment length polymorphism (PCR-RFPL). Point mutations at codon 12 of KRAS oncogene were identified in 7 of 49 (14,3%) tumor specimens and in 2 of 11 (18,2%) hyperplasias. No correlation was found between KRAS gene mutation and age at onset, histology, grade of differentiation and clinical stage. We conclude that KRAS mutation is a relatively common event in endometrial carcinogenesis, but with no prognostic value
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