Initial cranial CT scan for the assessment of prognosis in head injury

Summary A total of 208 multiple trauma patients with head injury (HI) were investigated who had been treated in the period from 1990 to 1995. The average age was 35.2 ± 17.7 years; the injury severity according to ISS was 30.2 ± 8.6 points; 20.5 % died as a result of the HI; the mortality of all patients was 26.5 %. The Glasgow Coma Scale (GCS) was determined at an average of 22 min after trauma (8.0 ± 4.3 points) at the scene of accident. The patients were classified according to GCS into minor HI (group 1: 14–15 points), moderate HI (group 2: 9–13 points) and severe HI (group 3: 3–8 points). Patient outcome was assessed by the Glasgow Outcome Scale (GOS) and was classified as good (GOS 4 and 5) and poor (GOS 1, 2 and 3) outcome. At the latest, 2 h after trauma, a CT scan of the head (CCT) was done. The HI groups are compared regarding frequency of types of injury. In all HI groups the fractures of the bony face occurred at the same frequency (36.0–38.9 %). The frequency of calotte fractures (Kal-Fx) increased from group 1 (8.0 %) to 2 (19.2 %) and 3 (25.6 %); fractures of the skull base significantly differed between group 1 (16.0 %), 2 (7.8 %) and 3 (33.4 %). Epidural hemorrhage (EDB) appeared only in group 2 (7.8 %) and 3 (6.7); subdural hemorrhage was found in group 1 (2.7 %), 2 (7.8 %) and 3 (10.0 %). Subarachnoid hemorrhage (SAB) was significantly more frequently seen, dependent on HI severity, in group 3 (26.7 %) compared to group 2 (11.7 %) and 1 (8.0 %). Intracerebral contusion (ICK) significantly increased from group 1 (12.0 %) to 2 (27.3) and 3 (45.6 %). Brain swelling (BS) also significantly increased from group 1 (8.0 %) to 2 (19.5 %) and 3 (49.0 %) and lesions of ventricles (VL) from group 1 (2.7 %) to 2 (11.7 %) and 3 (20.0 %). Midline shift (13.4 %) and signs of herniation (4.5 %) only occurred in group 3. The analysis of correlation/regression and receiver operating characteristics was able to predict 79 % of patients' outcome accurately using GCS (r 0.54; P < 0.0001) alone, using CCT (r 0.65; P < 0.0001) 87 % were correctly predicted with significant variables Cal-Fx, EDB, SAB and BS. CCT with GCS (r 0.74; P < 0.0001) were able to predict 88 % accurately with significant variables Cal-Fx, EDB, BS and GCS. The combination of CCT with GCS, age and ISS (r 0.78; P < 0.0001) was able to predict only 87 % correctly, although the r value was the highest; significant variables were Kal-Fx, EDB, BS, VL, GCS, age and ISS.      

Ultrasound for the assessment of the embolic risk of carotid plaques

In a prospective study we compared duplex-ultrasound characteristics of symptomatic internal carotid artery (ICA) stenoses with cranial computerized tomographic (CCT) findings in 82 patients suffering from completed or transient middle cerebral artery symptoms. The aim was to assess the pathogenic role of ICA plaque morphology and the potential embolic risk of ICA plaques. The degree of carotid stenosis was estimated by spectral analysis of the pulsed Doppler signal. The CCT findings were classified as being either normal, lacunar lesions, hemodynamically induced low-perfusion infarctions, or territorial embolic infarctions. According to their ultrasonic features we characterized the ICA plaque surface as smooth or irregular and their structure as homogeneous or heterogeneous. Plaques with an irregular surface and heterogeneous echogenicity dominated significantly in CCT-territorial infarctions (p < 0.01), whereas hemodynamically induced low-perfusion infarctions showed no relationship with any plaque characteristic. High degree ICA stenoses (> 50>%) dominated in both territorial infarctions and low-perfusion infarctions, as compared to ipsilateral normal CCT or lacunes (p < 0.05). Normal CCT and lacunar infarctions were associated with homogeneous and smooth plaques (both p < 0.05). We conclude that > 50% ICA stenoses can cause both hemodynamically induced low-perfusion infarctions as well as thromboembolic territorial infarctions, whereas ulcerated and heterogeneous plaques constitute a high risk factor for arterio-arterial embolic stroke. Furthermore, carotid ultrasound may help to estimate the clinical significance of carotid lesions.     

高眼压症和青光眼患者角膜中央厚度的研究

目的研究高眼压症和原发性开角型青光眼患者的角膜中央厚度(central corneal thickness,CCT),探讨CCT对Goldmann眼压计眼压测量的影响.方法分别用超声角膜测厚仪和Goldmann眼压计对原发性开角型青光眼病例18例36只眼和高眼压症患者15例26只眼以及正常对照组18例36只眼行角膜中央厚度和眼压(intraocular pressure,IOP)测量,并进行统计学分析.结果CCT在高眼压组为572.76±37.42(μm),原发性开角型青光眼组为548.41±34.15(μm),对照组为547.22±34.68(μm).高眼压组CCT值明显大于原发性开角型青光眼组和正常对照组,差异有显著性(P＜0.05),CCT在后两组间差异不显著(P＞O.05).46%的高眼压患者校正眼压正常.结论CCT是影响眼压测量的重要因素,诊断高眼压症的同时应该测量CCT.     

Artificial Neural Network Modelling of the Effect of Vanadium Addition on the Tensile Properties and Microstructure of High-Strength Tempcore Rebars

In high-strength rebar, the various microstructures obtained by the Tempcore process and the addition of V have a complex effect on the strength improvement of rebar. This study investigated the mechanism of strengthening of high-strength Tempcore rebars upon the addition of vanadium through artificial neural network (ANN) modelling. Various V contents (0.005, 0.072 and 0.14 wt.%) were investigated, and a large amount of bainite and V(C, N) were precipitated in the core of the Tempcore rebar in the high-V specimens. In addition, as the V content increased, the number of these fine precipitates (10–30 nm) increased. The precipitation strengthening proposed by the Ashby–Orowan model is a major contributing factor to the yield-strength increase (35 MPa) of the Tempcore rebar containing 0.140 wt.% V. The ANN model was developed to predict the yield and tensile strengths of Tempcore rebar after the addition of various amounts of V and self-tempering at various temperatures, and it showed high reproducibility compared to the experimental values (R-square was 93% and the average relative error was 2.6%). ANN modelling revealed that the yield strength of the Tempcore rebar increased more significantly with increasing V content (0.01–0.2 wt.%.) at relatively high self-tempering temperatures (≥530 °C). These results provide guidelines for selecting the optimal V content and process conditions for manufacturing high-strength Tempcore rebars.     

Algorithm for Determining Time Series of Phase Transformations in the Solid State Using Long-Short-Term Memory Neural Network

In the numerical analysis of manufacturing processes of metal parts, many material properties depending on, for example, the temperature or stress state, must be taken into account. Often these data are dependent on the temperature changes over time. Strongly non-linear material property relationships are usually represented using diagrams. In numerical calculations, these diagrams are analyzed in order to take into account the coupling between the properties. An example of these types of material properties is the dependence of the kinetics of phase transformations in the solid state on the rate and history of temperature change. In literature, these data are visualized Continuous Heating Transformation (CHT) and Continuous Cooling Transformation (CCT) diagrams. Therefore, it can be concluded that time series analysis is important in numerical modeling. This analysis can also be performed using neural networks. This work presents a new approach to storing and analyzing the data contained in the discussed CCT diagrams. The application of Long-Short-Term Memory (LSTM) neural networks and their architecture to determine the correct values of phase fractions depending on the history of temperature change was analyzed. Moreover, an area of research was elements that determine what type of information should be stored by LSTM network coefficients, e.g., whether the network should store information about changes of single phase transformations, or whether it would be better to extract data from differences between several networks with similar architecture. The purpose of the studied network is strongly different from typical applications of artificial neural networks. The main goal of the network was to store information (even by overfitting the network) rather than some form of generalization that allows computation for unknown cases. Therefore, the authors primarily investigated in the ability of the layer-based LSTM network to store nonlinear time series data. The analyses presented in this paper are an extension of the issues presented in the paper entitled “Model of the Austenite Decomposition during Cooling of the Medium Carbon Steel Using LSTM Recurrent Neural Network”.     

计算机辅助细胞检测系统对子宫颈病变筛查的意义

目的:对应用计算机辅助细胞(CCT)检测系统进行子宫颈病变的细胞学诊断作出初步评价。方法:对妇科病普查中936例宫颈涂片标本采用PAPNET全自动电脑扫描和诊断系统行细胞学筛选,按TBS诊断分类标准诊断,并按不同年龄及宫颈光滑与糜烂程度进行对照。结果:正常821例,异常115例,其中不典型鳞状细胞性质未定(ASCUS)87例,低度鳞状上皮内病变(LSIL)26例,高度鳞状上皮内病变(HSIL)2例,异常涂片多见30~49岁年龄组,且宫颈光滑组与宫颈糜烂组阳性检出率无显著差异。结论:CCT是细胞学诊断的重要革新,有很高的敏感性和特异性,且效率高,适用于宫颈癌患者的大规模普查。     

Cardiac computed tomography in the contemporary evaluation of infective endocarditis

Increasing data have accumulated on the role of Cardiac Computed Tomography (CCT) in infective endocarditis (IE) with high accuracy for large vegetations, perivalvular complications and for exclusion of coronary artery disease to avoid invasive angiography. CCT can further help to clarify the etiology of infective prosthetic valve dysfunction (e.g. malposition, abscess, leak, vegetation or mass). Structural interventions have increased the relevance of CCT in valvular heart disease and have amplified its use. CCT may be ideally integrated into a multimodality approach that incorporates a central role of transesophageal echocardiography (TEE) with 18-FDG PET and/or cardiac magnetic resonance in individually selected cases, guided by the Heart Team. The coronavirus-19 (COVID-19) pandemic has resulted in renewed attention to CCT as a safe alternative or adjunct to TEE in selected patients. This review article provides a comprehensive, contemporary review on CCT in IE to include scan optimization, characteristics of common IE findings on CCT, published data on the diagnostic accuracy of CCT, multimodality imaging comparison, limitations and future technical advancements.     

Role of GABAA/benzodiazepine receptors containing α1 and α5 subunits in the discriminative stimulus effects of triazolam in squirrel monkeys

RATIONALE: Conventional benzodiazepines (BZs), clinically used for treatment of anxiety and insomnia, bind to GABA(A) receptors containing alpha(1), alpha(2), alpha(3), or alpha(5) subunits. The role of these different GABA(A) receptor subtypes in mediating the subjective effects of BZs remains largely unknown. OBJECTIVE: The purpose of the present study was to evaluate the role of GABA(A) receptors containing the alpha(1) or alpha(5) subunits in the discriminative stimulus (DS) effects of the conventional BZ agonist triazolam. METHODS: Squirrel monkeys were trained to discriminate triazolam (0.03 mg/kg, i.v.) from vehicle under a fixed-ratio 10 schedule of food reinforcement. RESULTS: The GABA(A)/alpha(1)-preferring agonists zolpidem and zaleplon engendered responses predominantly on the triazolam lever (73-80% drug-lever responding), and the GABA(A)/alpha(1) partial agonist CL 218,872 engendered an average maximum of less than 50% triazolam-lever responding. The GABA(A)/alpha(1)-preferring antagonists beta-carboline-3-carboxylate-t-butyl ester (betaCCT) and 3-(propyloxy)-beta-carboline (3-PBC) blocked the DS effects of triazolam and zolpidem in a surmountable manner. Schild analyses for betaCCT and 3-PBC in combination with triazolam and zolpidem suggest that the interactions between these compounds were competitive in nature and mediated by a common population of receptors, presumably GABA(A)/alpha(1) receptors. In contrast, the GABA(A)/alpha(5)-preferring agonist QH-ii-66 did not engender triazolam-lever responding regardless of dose and did not alter the DS effects of triazolam when administered in combination. CONCLUSIONS: The results are consistent with GABA(A)/alpha(1) receptor involvement in mediating the DS effects of triazolam. In contrast, binding to GABA(A)/alpha(5) receptors may not play a critical role in mediating triazolam's DS effects.     

Bithalamic infarcts: embolism of the top of basilar artery or deep cerebral venous thrombosis?

Bithalamic infarcts are usually attributed to thromboembolism of the top of the basilar artery. However, in some cases, deep cerebral venous thrombosis and thrombosis of cerebral venous sinuses was proved to be the cause. The case of a 47-year-old female with ischemic thalamic and mesencephalic lesions is reported, that was attributed to thrombosis of internal cerebral veins. In cases of bithalamic infarcts, apart from the top of the basilar artery syndrome, deep cerebral venous thrombosis should be taken into consideration. Neuroimaging findings such as generalized cerebral edema, multiple infarcts or hemorrhages, hyperdense appearance of cerebral sinuses or veins and filling defects in the cerebral venous sinuses in contrast-CCT, can lead to the proper diagnosis.