Αρχειοθήκη ιστολογίου

Κυριακή 22 Νοεμβρίου 2020

EEG Characteristics during Short-Term Spontaneous Waking Periods of Different Durations with Changes in Psychomotor Activity Induced by Falling Asleep

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Changes in EEG spectral characteristics during periods of recovery of performance in a psychomotor test during spontaneous short-term periods of waking in daytime sleep were studied in 17 healthy subjects. The test consisted of two sequentially alternating tasks: to count from 1 to 10 silently accompanied by synchronized pressing of a button, and silent counting only. The monotonous nature of the test led to a rapid decline in the level of consciousness and, in most cases, induced falling asleep. Presses serves as a behavioral indicator of the recovery of cognitive processes inhibited during sleep. Situations with small (2–5) and relatively large (6–10) numbers of button presses were compared. The start of pressing was preceded by the appearance of generalized α rhythm, which decreas ed during performance of psychomotor activity. The power of this rhythm was always greater in longer periods of observed behavioral activity. The end of pressing returned α-power indicators to levels seen before waking. The EEG α rhythm in decreased consciousness during short-term waking evidently characterized the action of the thalamocortical activatory mechanism and was a necessary condition for motor interaction of the body with the external environment. The absence of any differences in the frontal areas at the initial stage on performance of short-lived activity and longer-lasting activity, approaching performance of the complete cycle of presses, suggested that they are involved to the same extent during this period regardless of the number of presses. This result may provide indirect support for the notion that the observed psychomotor activity, even with a small number of presses, is not automatic and unconscious but is accompanied by reduced and fragmented consciousness.

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Cross-Correlation and Coherence Analysis of Electrocortigrams in Rats Subjected to Craniocerebral Trauma

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Craniocerebral trauma (CCT) is one of the leading causes of death and long-term loss of work capacity among the young population of both the Russian Federation and other countries. The development of adequate and reproducible models of CCT in laboratory animals and objective methods for assessing the extent of neurological impairments gives cause for optimism in seeking and studying new and effective neurorehabilitation approaches. The aim of the present work was to carry out a comparative cross-correlation and coherence analysis of electrocorticograms from presumptively healthy rats and animals subjected to CCT. After initial trepanning, open penetrating CCT was modeled by controlled cortical impacts applied to the motor cortex of the left hemisphere. Nichrome corticographic recording el ectrodes were implanted bilaterally in the primary and secondary motor cortex and in the primary somatosensory cortex (above the hippocampus). Electrocorticograms were recorded on days 3 and 7 after surgery in the home cage and in the resting state. Cross-correlation analysis consisted of computing the cross-correlation coefficient, the mean frequency, and the maximum span in the cross-correlation function. Mean coherence power levels for the δ, θ, α, and β rhythms were computed for pairs of leads. Unilateral traumatic damage to the motor cortex and underlying structures led to impairment to the operation of interhemisphere and intrahemisphere connections and these changes were seen not only in the impact area, but also in distant parts of the cortex on post-trauma days 3 and 7. These changes in ECoG cross-correlation and coherence parameters occurring in rats as a result of CCT were similar to those seen in patients in clinical practice, so it can be suggested that this experim ental model can be used for neurophysiological and pharmacological research.

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Absorbed dose simulation of meta - 211 At-astato-benzylguanidine using pharmacokinetics of 131 I-MIBG and a novel dose conversion method, RAP

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Abstract

Objective

We aimed to estimate in vivo 211At-labeled meta-benzylguanidine (211At-MABG) absorbed doses by the two dose conversion methods, using 131I-MIBG biodistribution data from a previously reported neuroblastoma xenograft model. In addition, we examined the effects of different cell lines and time limitations using data from two other works.

Methods

We used the framework of the Monte Carlo method to create 3200 virtual experimental data sets of activity concentrations (kBq/g) to get the statistical information. Time activity concentration curves were produced using the fitting method of a genetic algorithm. The basic method was that absorbed doses of 211At-MABG were calculated based on the medical internal radiation dose formalism with the conversion of the physical half-life time of 131I to that of 211At. We have further improved the basic method; that is, a novel dose conversion method, RAP (Ratio of Pharmacokinetics), using percent injected dose/g.

Results

Virtual experiments showed that 211At-MABG and 131I-MIBG had similar properties of initial activity concentrations and biological components, but the basic method did not simulate the 211At-MABG dose. Simulated 211At-MABG doses from 131I-MIBG using the RAP method were in agreement with those from 211At-MABG, so that their boxes overlapped in the box plots. The RAP method showed applicability to the different cell lines, but it was difficult to predict long-term doses from short-term experimental data.

Conclusions

The present RAP dose conversion method could estimate 211At-MABG absorbed doses from the pharmacokinetics of 131I-MIBG with some limitations. The RAP method would be applicable to a large number of subjects for targeted nuclide therapy.

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Evaluation of different airway tests to determine difficult intubation in apparently normal adult patients: undergoing surgical procedures

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Abstract

Background

Inadequate maintenance of a patient's airway represents a major cause of anesthesia-related morbidity and mortality. This study was designed to evaluate common preoperative clinical tests to determine the risk of difficult endotracheal intubation in apparent "normal" adult patients undergoing surgical procedures.

Methods

A prospective observational cohort study was performed on 160 consecutive adult patients undergoing surgical procedures at an academic medical center in Jordan from 20 May 2019 until 11 February 2020.

Preoperative assessment of airway risk stratification was performed by the following clinical tests: the mandible protrusion test (MPT), thyromental (TMD) and sternomental (SMD) distances, inter-incisor gap (IIG), and the modified Mallampati tests with tongue protrusion (MMT-TP) and without tongue protrusion (MMT-NTP). Grade C on the MPT, TMD ≤ 6 cm, SMD ≤ 12 cm, and MMT grades III and IV were considered to be predictors of difficult endotracheal intubations. A modified Cormack-Lehane grading (MCLG) of laryngoscopic views with backward, upward, and right-sided pressure on the thyroid and cricoid cartilages (BURP) maneuver was also documented, with grades 2B, 3, and 4 considered to be difficult airways for intubation.

Results

Fifteen patients (9.4%) were classified as MCLG 2B, 3, and 4, with age significantly associated with the MCLG grade (P = 0.028). The sensitivity and Youden's index of MMT-TP were found to be the lowest (40% and 0.29, respectively). The MPT was the most accurate and specific test (90.63 and 95.17%, respectively), with the highest PPV (50%), Youden's index (0.42), and area under the curve (AUC) (0.781). Bivariant analysis of MPT and the t-test of the mean TMDs and SMDs revealed significant associations between these airway tests and the difficulty of intubation (P values: < 0.001, 0.02, < 0.01, respectively).

Conclusion

The MPT, with its highest accuracy, specificity, positive predictive value, and good sensitivity may be used as a routine screening test for preoperative prediction of difficult endotracheal intubations.

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Provider confidence in the telemedicine spine evaluation: results from a global study

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Abstract

Purpose

To utilize data from a global spine surgeon survey to elucidate (1) overall confidence in the telemedicine evaluation and (2) determinants of provider confidence.

Methods

Members of AO Spine International were sent a survey encompassing participant's experience with, perception of, and comparison of telemedicine to in-person visits. The survey was designed through a Delphi approach, with four rounds of question review by the multi-disciplinary authors. Data were stratified by provider age, experience, telemedicine platform, trust in telemedicine, and specialty.

Results

Four hundred and eighty-five surgeons participated in the survey. The global effort included respondents from Africa (19.9%), Asia Pacific (19.7%), Europe (24.3%), North America (9.4%), and South America (26.6%). Providers felt that physical exam-based tasks (e.g., provocative testing, assessing neurologic deficits/myelopathy, etc.) were inferior to in-person exams, while communication-based aspects (e.g., history taking, imaging review, etc.) were equivalent. Participants who performed greater than 50 visits were more likely to believe telemedicine was at least equivalent to in-person visits in the ability to make an accurate diagnosis (OR 2.37, 95% C.I. 1.03–5.43). Compared to in-person encounters, video (versus phone only) visits were associated with increased confidence in the ability of telemedicine to formulate and communicate a treatment plan (OR 3.88, 95% C.I. 1.71–8.84).

Conclusion

Spine surgeons are confident in the ability of telemedicine to communicate with patients, but are concerned about its capacity to accurately make physical exam-based diagnoses. Future research should concentrate on standardizing the remote examination and the development of appropriate use criteria in order to increase provider confidence in telemedicine technology.

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Problems with Early Systematic Reviews: The Case of Coronavirus Disease 2019 (COVID-19) in Pregnancy

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Abstract

Introduction

Rapid dissemination of findings regarding the Coronavirus Disease 2019 (COVID-19) and its potential effects on pregnancy is crucial to support understanding and development of recommendations for optimization of obstetrics care. However, much of the current studies published are in the form of case reports or case series which can be prone to biases. Other factors also further complicate attempts to analyze data accurately. Hence, this evaluation hopes to highlight some of these problems and provide suggestions to help clinicians mitigate and make reasonable conclusions when reading the abundant yet limited body of evidence when furthering their research efforts.

Methods

Studies regarding COVID-19 and pregnancy were searched on databases such as PubMed, EMBASE, Scopus, the Cochrane Library. Manual search of references of select articles were also undertaken. Apart from summarizing study limitations identified by authors, the characteristics of current literature and systematic reviews were also evaluated to identify potential factors affecting accuracy of subsequent analysis.

Results

Factors such as innate biasness in study design of current literature, duplicate reporting, differing inclusion criteria of systematic reviews, scarce data, inadequate follow-up period and limitations of systematic reviews have been shown to hinder the ability for accurate data extrapolation.

Discussion

Unless additional studies are conducted in identified areas of data scarcity and a common list of factors affecting accuracy of data analysis are taken into account when developing recommendations, discrepancies will continue to arise and accurate data analysis and valid systematic reviews will be precluded.

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Incidence, impact and risk factors for multidrug-resistant organisms (MDRO) in patients with major trauma: a European Multicenter Cohort Study

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Abstract

Introduction

The burden of MDRO in health systems is a global issue, and a growing problem. We conducted a European multicenter cohort study to assess the incidence, impact and risk factors for multidrug-resistant organisms in patients with major trauma. We conducted this study because the predictive factors and effects of MDRO in severely injured patients are not yet described. Our hypothesis is that positive detection of MDRO in severely injured patients is associated with a less favorable outcome.

Methods

Retrospective study of four level-1 trauma centers including all patients after major trauma with an injury severity score (ISS) ≥ 9 admitted to an intensive care unit (ICU) between 2013 and 2017. Outcome was measured using the Glasgow outcome scale (GOS).

Results

Of 4131 included patients, 95 (2.3%) had a positive screening for MDRO. Risk factors for MDRO were male gender (OR 1.73 [95% CI 1.04–2.89]), ISS (OR 1.01 [95% CI 1.00–1.03]), PRBC's given (OR 1.73 [95% CI 1.09–2.78]), ICU stay > 48 h (OR 4.01 [95% CI 2.06–7.81]) and mechanical ventilation (OR 1.85 [95% CI 1.01–3.38]). A positive MDRO infection correlates with worse outcome. MDRO positive cases GOS: good recovery = 0.6%, moderate disability = 2.1%, severe disability = 5.6%, vegetative state = 5.7% (p < 0.001).

Conclusions

MDRO in severely injured patients are rare but associated with a worse outcome at hospital discharge. We identified potential risk factors for MDRO in severely injured patients. Based on our results, we recommend a standardized screening procedure for major trauma patients.

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Sagittal imbalance and symptoms of depression in adults: Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study (LOHAS)

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Abstract

Purpose

With spinal deformities, mental health can deteriorate due to sagittal imbalance of the spine. The purpose of this study was to clarify the relationship between sagittal imbalance and symptoms of depression among local residents in the community.

Methods

This study used data from the Locomotive Syndrome and Health Outcomes in Aizu Cohort Study (LOHAS) in 2010. The sagittal vertical axis (SVA) was identified as an indicator of sagittal imbalance. Symptoms of depression were assessed using the 5-item version of the Mental Health Inventory. Participants were classified into three categories based on the SVA balance as normal (< 40 mm), moderate imbalance (40–95 mm), and severe imbalance (> 95 mm). To evaluate the relationship between sagittal imbalance of the spine and symptoms of depression, the adjusted risk ratio (RR) and the 95% confidence interval (CI) were calculated using a generalized linear model with Poisson link.

Results

There were 786 participants included in the statistical analysis. Overall, the mean age was 68.1 y (standard deviation, 8.8 y), and 39.4% were men. The prevalence of symptoms of depression by SVA category was 18.6% for normal, 23.8% for moderate, and 40.6% for severe. On multivariate analysis, the RR of SVA for symptoms of depression compared to the normal category was 1.12 (95% CI 0.7–1.70) for the moderate category and 2.29 (95% CI 1.01–5.17) for the severe category.

Conclusion

In local community residents, sagittal imbalance had a significant association with symptoms of depression.

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Application of an attention U-Net incorporating transfer learning for optic disc and cup segmentation

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Abstract

Optic disc (OD) and optic cup (OC) regional parameters are of utmost importance in the early diagnosis of glaucoma. Improving the accuracy of OD/OC segmentation results and parameter extraction in colour fundus images plays a very important role in early glaucoma screening. To improve the accuracy and inference speed of fundus image segmentation, an algorithm for fundus image segmentation based on an attention U-Net with transfer learning is proposed in this paper. First, an attention gate was added between the encoder and decoder of U-Net to focus on the target areas, thus forming the architecture of the attention U-Net. Then, after the network had been trained on the DRIONS-DB dataset to partially obtain the weights of the encoder, it was trained on the Drishti-GS dataset to further modify the weights. Finally, the trained attention U-Net model incorporating transfer learning was used to segment fundus images. OD/OC extraction using this method shows obvious ad vantages in model parameter quantity and inference time compared with existing algorithms, the parameter quantity is much smaller than that of existing algorithms, and the model inference time is 0.33 s, representing a reduction of more than 50%. The proposed method can be applied to a fundus image dataset with only a small number of labels. Whilst offering fast OD/OC segmentation, it also guarantees a relatively high segmentation accuracy.

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Evaluating the Relationship Between Post Traumatic Stress Disorder Symptoms and Psychological Resilience in a Sample of Turkoman Refugees in Turkey

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Abstract

Turkey has witnessed an increase in migration of people belonging to neighboring countries due to civil war. Traumatic life events experienced by refugees bring along mental problems. Their psychological resilience enables them to cope with these difficulties. In this study, 101 Iraqi Turkoman refugees who migrated to Turkey following the increasing civil war events in their country were evaluated psychologically. Sociodemographic data form Resilience Scale for Adults (RSA) and Clinician-Administered Post-Traumatic Stress Disorder Scale (CAPS) were used for psychological evaluation. The prevalence of lifetime post-traumatic stress disorder (PTSD) among the refugees was 25.7%. There was no significant difference between the psychological resilience of the patients who developed PTSD and those who did not (p = 0.709). As the severity of trauma decreased, psychological resilience increased in the people who developed PTSD (p = 0.001, r = −0.622). Consi dering the psychological resilience of refugees, the area with the highest resilience is access to social resources, while the area with the lowest is the planned future. It was observed that the basic needs of refugees after migration could not be met clearly compared to the ones before migration. It was noteworthy that in cases diagnosed with PTSD, CAPS scores increased (p = 0.011, r: 0.251) and resilience decreased (p < 0.001, r: −0.376) as the inability to reach basic needs increased. Our study is very important in terms of defining how refugees are mentally affected after settling in another country and what determines their psychological resilience.

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Numerical investigation of patient-specific thoracic aortic aneurysms and comparison with normal subject via computational fluid dynamics (CFD)

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Abstract

Vascular hemodynamics play an important role in cardiovascular diseases. This work aimed to investigate the effects of an increase in ascending aortic diameter (AAD) on hemodynamics throughout a cardiac cycle for real patients. In this study, two scans of thoracic aortic aneurysm (TAA) subject with different AADs (42.94 mm and 48.01 mm) and a scan of a normal subject (19.81 mm) were analyzed to assess the effects of hemodynamics on the progression of TAA with the same flow rate. Real-patient aortic geometries were scanned by computed tomography angiography (CTA), and steady and pulsatile flow conditions were used to simulate real patient aortic geometries. Aortic arches were obtained from routine clinical scans. Computational fluid dynamics (CFD) simulations were performed with in vivo boundary conditions, and 3D Navier-Stokes equations were solved by a UDF (user-defined function) code defining a real cardiac cycle of one patient using Fourier seri es (FS). Wall shear stress (WSS) and pressure distributions were presented from normal subject to TAA cases. The results show that during the peak systolic phase pressure load increased by 18.56% from normal subject to TAA case 1 and by 23.8% from normal subject to TAA case 2 in the aneurysm region. It is concluded that although overall WSS increased in aneurysm cases but was low in dilatation areas. As a result, abnormal changes in WSS and higher pressure load may lead to rupture and risk of further dilatation. CFD simulations were highly effective to guide clinical predictions and assess the progress of aneurysm regions in case of early surgical intervention.

Graphical abstract
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