224 research outputs found

    ΠœΠ°Π³Π½ΠΈΡ‚ΠΎΡΠ»Π΅ΠΊΡ‚Ρ€ΠΈΡ‡Π΅ΡΠΊΠΈΠΉ Π΄Π²ΠΈΠ³Π°Ρ‚Π΅Π»ΡŒ для ΠΏΡ€ΠΈΠ²ΠΎΠ΄Π° Ρ€ΡƒΠ»Π΅Π²ΠΎΠΉ ΠΊΠΎΠ»ΠΎΠ½ΠΊΠΈ автотранспортного срСдства

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    Научная квалификационная Ρ€Π°Π±ΠΎΡ‚Π° посСщСна исслСдованию ΠΏΡƒΠ»ΡŒΡΠ°Ρ†ΠΈΠΉ элСктромагнитного ΠΌΠΎΠΌΠ΅Π½Ρ‚Π° Π² магнитоэлСктричСском Π΄Π²ΠΈΠ³Π°Ρ‚Π΅Π»Π΅ Ρ€ΡƒΠ»Π΅Π²ΠΎΠΉ ΠΊΠΎΠ»ΠΎΠ½ΠΊΠΈ автотранспортного срСдства. Π’ ΠΏΠ΅Ρ€Π²ΠΎΠΉ Π³Π»Π°Π²Π΅ Π²Ρ‹ΠΏΠΎΠ»Π½Π΅Π½ ΠΎΠ±Π·ΠΎΡ€ исслСдований Π½Π° Ρ‚Π΅ΠΌΡƒ магнитоэлСктричСских машин с Ρ€Π°Π·Π»ΠΈΡ‡Π½ΠΎΠΉ ΠΊΠΎΠΌΠΏΠΎΠ½ΠΎΠ²ΠΊΠΎΠΉ ΠΌΠ°Π³Π½ΠΈΡ‚ΠΎΠ² Π½Π° Ρ€ΠΎΡ‚ΠΎΡ€Π΅ ΠΈ осущСствлСна постановка Π·Π°Π΄Π°Ρ‡ΠΈ Π½Π°ΡƒΡ‡Π½ΠΎΠΉ ΠΊΠ²Π°Π»ΠΈΡ„ΠΈΠΊΠ°Ρ†ΠΈΠΎΠ½Π½ΠΎΠΉ Ρ€Π°Π±ΠΎΡ‚Ρ‹. Π’ΠΎ Π²Ρ‚ΠΎΡ€ΠΎΠΉ Π³Π»Π°Π²Π΅ рассмотрСны вопросы ΠΈΠΌΠΈΡ‚Π°Ρ†ΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ модСлирования магнитоэлСктричСской ΠΌΠ°ΡˆΠΈΠ½Ρ‹ Π² ΠΊΠΎΠ½Π΅Ρ‡Π½ΠΎ-элСмСнтной ΠΊΠΎΠΌΠΏΡŒΡŽΡ‚Π΅Ρ€Π½ΠΎΠΉ срСдС. Π’Ρ‹ΠΏΠΎΠ»Π½Π΅Π½ΠΎ ΠΏΠ»Π°Π½ΠΈΡ€ΠΎΠ²Π°Π½ΠΈΠ΅ экспСримСнта, ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½Π° взаимосвязь ΠΌΠ΅ΠΆΠ΄Ρƒ количСством ΠΏΠ°Π·ΠΎΠ² Ρ€ΠΎΡ‚ΠΎΡ€Π°, Π·ΡƒΠ±Ρ†Π°ΠΌΠΈ статора, коэрцитивной силы ΠΌΠ°Π³Π½ΠΈΡ‚ΠΎΠ² с ΠΏΠΎΠ·ΠΈΡ†ΠΈΠΈ Π·Π½Π°Ρ‡Π΅Π½ΠΈΠΉ элСктромагнитного ΠΌΠΎΠΌΠ΅Π½Ρ‚Π°. Π’ Ρ‚Ρ€Π΅Ρ‚ΡŒΠ΅ΠΉ Π³Π»Π°Π²Π΅ Π²Ρ‹ΠΏΠΎΠ»Π½Π΅Π½ расчСт связанной ΠΌΠΎΠ΄Π΅Π»ΠΈ магнитоэлСктричСский Π΄Π²ΠΈΠ³Π°Ρ‚Π΅Π»ΡŒ-ΠΈΠ½Π²Π΅Ρ€Ρ‚ΠΎΡ€ напряТСния-систСма управлСния.Scientific qualification work is visited to a research of pulsations of the electromagnetic torque in the magnetoelectric motor of a steering column of the vehicle. In chapter 1 the review of researches on magnetoelectric machine with various configuration of magnets on a rotor is executed and problem definition of scientific qualification work is carried out. In chapter 2 questions of a simulation modeling of the magnetoelectric machine in the terminating and element computer environment are considered. Scheduling of an experiment is executed, the interrelation between quantity of poles of a rotor, tooths of a stator, a coercive force of magnets from a position of values of the electromagnetic torque is received. In a chapter 3 calculation of the bound model the magnetoelectric motor

    PET-MR imaging using a tri-modality PET/CT-MR system with a dedicated shuttle in clinical routine

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    Tri-modality PET/CT-MRI includes the transfer of the patient on a dedicated shuttle from one system into the other. Advantages of this system include a true CT-based attenuation correction, reliable PET-quantification and higher flexibility in patient throughput on both systems. Comparative studies of PET/MRI versus PET/CT are readily accomplished without repeated PET with a different PET scanner at a different time point. Additionally, there is a higher imaging flexibility based on the availability of three imaging modalities, which can be combined for the characterization of the disease. The downside is a somewhat higher radiation dose of up to 3mSv with a low dose CT based on the CT-component, longer acquisition times and potential misalignment between the imaging components. Overall, the tri-modality PET/CT-MR system offers comparative studies using the three different imaging modalities in the same patient virtually at the same time, and may help to develop reliable attenuation algorithms at the same tim

    Identifying predictive features of autism spectrum disorders in a clinical sample of adolescents and adults using machine learning

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    Diagnosing autism spectrum disorders (ASD) is a complicated, time-consuming process which is particularly challenging in older individuals. One of the most widely used behavioral diagnostic tools is the Autism Diagnostic Observation Schedule (ADOS). Previous work using machine learning techniques suggested that ASD detection in children can be achieved with substantially fewer items than the original ADOS. Here, we expand on this work with a specific focus on adolescents and adults as assessed with the ADOS Module 4. We used a machine learning algorithm (support vector machine) to examine whether ASD detection can be improved by identifying a subset of behavioral features from the ADOS Module 4 in a routine clinical sample of N = 673 high-functioning adolescents and adults with ASD (n = 385) and individuals with suspected ASD but other best-estimate or no psychiatric diagnoses (n = 288). We identified reduced subsets of 5 behavioral features for the whole sample as well as age subgroups (adolescents vs. adults) that showed good specificity and sensitivity and reached performance close to that of the existing ADOS algorithm and the full ADOS, with no significant differences in overall performance. These results may help to improve the complicated diagnostic process of ASD by encouraging future efforts to develop novel diagnostic instruments for ASD detection based on the identified constructs as well as aiding clinicians in the difficult question of differential diagnosis

    Diagnostic accuracy of contrast-enhanced FDG-PET/CT in primary staging of cutaneous malignant melanoma

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    Purpose: To evaluate the diagnostic accuracy of contrast-enhanced FDG-PET/CT (ce-PET/CT), PET-only, and CT-only in patients with newly diagnosed and resected cutaneous malignant melanoma. Methods: A final group of 56 patients (mean age 62years, range 23-86years; 29 women, 27 men) were staged with ce-PET/CT after resection of the primary tumour. Histopathology as well as clinical follow-up (mean 780days, range 102-1,390 days) served as the standards of reference. Differences between the staging modalities were tested for statistical significance with McNemar's test. Results: All imaging procedures provided low sensitivities in the detection of lymph nodes (sensitivity N-stage: PET/CT and PET-only 38.5%; CT-only 23.1%) and distant metastases (sensitivity M-stage: PET/CT 41.7%, PET-only 33.3%, CT-only 25.0%) in initial staging after resection of the primary tumour. No statistically significant differences were detected between the imaging procedures (p > 0.05). PET/CT resulted in an alteration in further treatment in two patients compared to PET-only and in four patients compared to CT-only. Conclusion: All imaging modalities had a low sensitivity on initial staging of patients with malignant melanoma. Thus, close patient follow-up must be considered mandator

    Development and validation of an automated liquid-liquid extraction GC/MS method for the determination of THC, 11-OH-THC, and free THC-carboxylic acid (THC-COOH) from blood serum

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    The analysis of Ξ”9-tetrahydrocannabinol (THC) and its metabolites 11-hydroxy-Ξ”9-tetrahydrocannabinol (11-OH-THC), and 11-nor-9-carboxy-Ξ”9-tetrahydrocannabinol (THC-COOH) from blood serum is a routine task in forensic toxicology laboratories. For examination of consumption habits, the concentration of the phase I metabolite THC-COOH is used. Recommendations for interpretation of analysis values in medical-psychological assessments (regranting of driver’s licenses, Germany) include threshold values for the free, unconjugated THC-COOH. Using a fully automated two-step liquid-liquid extraction, THC, 11-OH-THC, and free, unconjugated THC-COOH were extracted from blood serum, silylated with N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA), and analyzed by GC/MS. The automation was carried out by an x-y-z sample robot equipped with modules for shaking, centrifugation, and solvent evaporation. This method was based on a previously developed manual sample preparation method. Validation guidelines of the Society of Toxicological and Forensic Chemistry (GTFCh) were fulfilled for both methods, at which the focus of this article is the automated one. Limits of detection and quantification for THC were 0.3 and 0.6 ΞΌg/L, for 11-OH-THC were 0.1 and 0.8 ΞΌg/L, and for THC-COOH were 0.3 and 1.1 ΞΌg/L, when extracting only 0.5 mL of blood serum. Therefore, the required limit of quantification for THC of 1 ΞΌg/L in driving under the influence of cannabis cases in Germany (and other countries) can be reached and the method can be employed in that context. Real and external control samples were analyzed, and a round robin test was passed successfully. To date, the method is employed in the Institute of Legal Medicine in Giessen, Germany, in daily routine. Automation helps in avoiding errors during sample preparation and reduces the workload of the laboratory personnel. Due to its flexibility, the analysis system can be employed for other liquid-liquid extractions as well. To the best of our knowledge, this is the first publication on a comprehensively automated classical liquid-liquid extraction workflow in the field of forensic toxicological analysis

    Extended stereotactic brain biopsy in suspected primary central nervous system angiitis: good diagnostic accuracy and high safety

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    OBJECTIVE To evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous system (PACNS). METHODS A standardized stereotactic biopsy targeting MRI-positive lesions and collecting samples from the meninges and the cortex as well as from the white matter was performed in 23 patients with clinically suspected PACNS between 2010 and 2017. The relationship between biopsy yield and clinical characteristics, cerebrospinal fluid parameters, MR-imaging, time point of biopsy and exact localization of biopsy as well as number of tissue samples were examined. RESULTS PACNS was confirmed in 7 of 23 patients (30.4%). Alternative diagnoses were identified in 7 patients (30%). A shorter time period between the onset or worsening of symptoms (p = 0.018) and ESBB significantly increased the diagnostic yield. We observed only minor and transient postoperative complications in 3 patients (13.0%). ESBB led to a direct change of the therapeutic regime in 13 of 23 patients (56.5%). Careful neuropathological analysis furthermore revealed that cortical samples were crucial in obtaining a diagnosis. CONCLUSION ESBB is a safe approach with good feasibility, even in critically ill patients, and high diagnostic accuracy in patients with suspected PACNS changing future therapies in 13 of 23 patients (56.5%). Early biopsy after symptom onset/worsening is crucial and (sub)acute MRI-lesions should be targeted with a particular need for biopsy samples from the cortical layer

    Time Period From Onset of Pain to Hospital Admission and Patients' Awareness in Acute Pancreatitis

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    Objectives: This study aimed to explore the period between onset of pain and hospital-admission (pain-to-admission time) in patients with acute pancreatitis (AP), to investigate the prognostic value and associated factors of this time, and to ascertain the knowledge about the pancreas in these patients. Methods: An analysis of a prospective multicenter study was done, which included 188 patients with AP. Results: Median pain-to-admission time was 27 hours (interquartile range, 6.0-72.0). Median pain-to-admission time was significantly shorter in intensive care unit (ICU) patients (10 hours) compared to non-ICU patients (36 hours) (P = 0.045). Short pain-to-admission time was associated with high pain level. Median pain level (0, no pain; 10, maximal pain) was 8.0 (interquartile range, 7.0-10.0). Older age correlated with lower pain level (r = -0.26; P = 0.002). Multiple logistic regression analysis including the admission values for serum lipase and C-reactive protein and the corresponding interactions to the pain-to-admission time showed substantial discriminative ability regarding ICU admission (concordance index, 0.706; P = 0.006). 86% (112/130) knew that they have a pancreas, 72% (81/112) of these patients knew that AP exists, and 56% (45/81) recognized that AP is potentially fatal. Conclusions: Knowledge about AP in hospitalized AP patients is poor. Serum lipase and C-reactive protein in dependency of the pain-to-admission time might be a suitable predictor for severity of AP

    Standardized Diagnostics Including PET-CT Imaging, Bilateral Tonsillectomy and Neck Dissection Followed by Risk-Adapted Post-Operative Treatment Favoring Radio-Chemotherapy Improve Survival of Neck Squamous Cell Carcinoma of Unknown Primary Patients

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    Background: About five to 10% of cancers in the head and neck region are neck squamous cell carcinoma of unknown primary (NSCCUP). Their diagnosis and treatment are challenging given the risk of missing occult tumors and potential relapse. Recently, we described human papillomavirus (HPV)-related NSCCUP-patients (NSCCUP-P) as a subgroup with superior survival. However, standardized diagnostic workup, novel diagnostic procedures, decision-making in the multidisciplinary tumor board (MDTB) and multimodal therapy including surgery and post-operative radio-chemotherapy (PORCT) may also improve survival. Methods: For assessing the impact of standardized diagnostic processes simultaneously established with the MDTB on outcome, we split our sample of 115 NSCCUP-P into two cohorts treated with curative intent from 1988 to 2006 (cohort 1; n = 53) and 2007 to 2018 (cohort 2; n = 62). We compared diagnostic processes and utilized treatment modalities applying Chi-square tests, and outcome by Kaplan–Meier plots and Cox regression. Results: In cohort 2, the standardized processes (regular use of [18F]-FDG-PET-CT imaging followed by examination under anesthesia, EUA, bilateral tonsillectomy and neck dissection, ND, at least of the affected site) improved detection of primaries (P = 0.026) mostly located in the oropharynx (P = 0.001). From 66.0 to 87.1% increased ND frequency (P = 0.007) increased the detection of extracapsular extension of neck nodes (ECE+) forcing risk factor-adapted treatment by increased utilization of cisplatin-based PORCT that improved 5-years progression-free and overall survival from 60.4 and 45.3 to 67.7% (P = 0.411) and 66.1% (P = 0.025). Conclusions: Standardized diagnostic workup followed by ND and risk-factor adapted therapy improves survival of NSCCUP-P
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