Der Einfluss von Hypoxie bei simulierten Flugreisen auf kardiale Repolarisation und Oxygenierung bei chronisch obstruktiver Lungenerkrankung

Hintergrund und Zielsetzung: Die chronisch obstruktive Lungenerkrankung (COPD) ist eine Volkskrankheit, die zu chronischer Hypoxie führen kann. Da viele COPD-Patienten gewillt sind, Flugreisen zu unternehmen sind die Effekte eines verminderten Sauerstoffpartialdrucks in Flugzeugkabinen im Reiseflug auf diese Patienten von besonderem klinischem Interesse. Vorherige Studien haben Beeinträchtigungen der zerebralen Oxygenierung und der kardialen Repolarisation bei COPD-Patienten aufgezeigt. Das Ziel dieser Studie war die Untersuchung der Veränderungen der zerebralen Oxygenierung und der kardialen Repolarisation dieser Patienten während eines Hypoxie-Belastungstest in Kombination mit milder körperlicher Anstrengung. Methoden: COPD-Patienten und Kontrollprobanden ohne Lungenerkrankungen unterliefen ein Testprotokoll, welches aus drei Phasen bestand: Zunächst wurde unter normoxischen Ruhebedingungen die regionale zerebrale Sauerstoffsättigung (rSO2) im linken und rechten frontalen Kortex mittels Nah-infrarot Spektroskopie (NIRS) gemessen. Zudem wurde die pulsoxymetrische Sauerstoffsättigung (SpO2), die Herzfrequenz und der Blutdruck aufgezeichnet sowie ein 12-Kanal-EKG abgeleitet. Anschließend erfolgte eine fahrradergometrische, milde körperliche Belastung (25 W), welche in zehn Minuten Normoxie und 30 Minuten milder Hypoxie (FiO2=0,15) aufgeteilt wurde. Währenddessen wurden die genannten Parameter im Zwei-Minuten-Intervall aufgezeichnet. Hinsichtlich der EKG-Parameter wurden P, PQ, QRS, QT, QTc, QTd, TpTe (T-peak-T-end Intervall), TpTec (korrigierte TpTe) und TpTed (TpTe-Dispersion) anhand von drei EKG-Komplexen unter Ruhebedingungen, am Ende der prähypoxischen Phase und am Ende der hypoxischen Phase gemessen. Ergebnisse: Zehn COPD-Patienten und zehn Kontrollprobanden ohne Lungenerkrankungen wurden in diese Studie eingeschlossen. Während des gesamten Tests war die SpO2 der COPD-Patienten signifikant niedriger. Die frontozerebrale rSO2 der COPD-Patienten war während der hypoxischen Phase linksseitig signifikant niedriger als in der Kontrollgruppe (59,5±8,5 vs. 67,5±5,7 %, p=0,035). Hinsichtlich der Parameter der kardialen Repolarisation zeigte sich bei den COPD-Patienten eine signifikant höhere TpTec in der prähypoxischen Phase (104±10 vs. 88±14 ms, p=0,004). Schlussfolgerung: Die vorliegende Studie zeigt erstmals eine verminderte linksfrontal zerebrale Oxygenierung während eines Hypoxiebelastungstests bei COPD-Patienten. Dieses Ergebnis lässt eine verminderte Höhenbelastbarkeit von COPD-Patienten vermuten, was in einer eingeschränkten Flugtauglichkeit resultieren könnte.Background and Objectives: Chronic obstructive pulmonary disease (COPD) is a widespread disease that can result in chronic hypoxia. Since many patients with COPD wish to travel by air, the effects of a diminish partial pressure of oxygen in aircraft cabins at cruising altitude are of special clinical interest. Previous studies have shown disturbances of cerebral oxygenation and cardiac repolarization in COPD patients. The aim of this study was to assess changes of cerebral oxygenation as well as parameters of cardiac repolarization during a hypoxia altitude simulation combined with mild physical activity in these patients. Methods: Patients with COPD and control subjects without lung diseases conducted a test which consisted of three phases. First, the regional cerebral oxygen saturation (rSO2) of the left and right frontal cortex was measured at rest using near-infrared spectroscopy (NIRS). Furthermore, pulsoxymetric saturation (SpO2), blood pressure and heart rate values as well as a 12-lead-ECG were recorded. Subsequently, a mild treadmill exercise program (25 W) was divided into ten minutes of normoxia (prehypoxia) and 30 minutes of mild hypoxia (FiO2=0,15). Meanwhile, mentioned parameters were recorded in a two minutes interval. As for ECG parameters, P, PQ, QRS, QT, QTc, QTd, TpTe (T-peak-T-end interval), TpTec (corrected TpTe) and TpTed (TpTe dispersion) were measured on three ECG complexes each at baseline, at the end of the normoxic phase and at the end of the hypoxic phase. Results: Ten patients with COPD and ten control subjects were included into this study. SpO2 was significantly lower in COPD-Patients throughout the whole test. Frontocerebral rSO2 was significantly lower in the left hemisphere during hypoxia altitude simulation in COPD patients (59.5±8.5 vs. 67.5±5.7 %, p=0.035). Regarding parameters of cardiac repolarisation TpTec during prehypoxia was significantly higher in COPD patients (104±10 vs. 88±14 ms, p=0.004). Conclusion: This study is the first to show reduced left frontal cerebral oxygenation during hypoxia and mild exercise in patients with COPD. This result suggests a diminished altitude resilience in COPD patients, which may limit their fitness to fly

First report of Fusarium avenaceum causing branch canker on pear in Turkey

Pear (Pyrus communis) is an important fruit crop in Turkey. In May 2021, canker lesions were observed in pruning wounds on approximately 70% of the pear trees cultivar Deveci in a fve-year-old orchard in Bursa province, Turkey. Disease symptoms were twig blight, brownish bark and branch canker. Twenty small pieces from branch lesions were surface disinfected with 1% NaOCl solution for 3 min and placed on potato dextrose agar. Petri dishes were incubated for 10 days at 23 °C. All colonies were Fusarium-like with the production of a yellow to rose pigment and a dark pink to red reverse with abundant white aerial mycelium

Added Value of Tomoelastography for Characterization of Pancreatic Neuroendocrine Tumor Aggressiveness Based on Stiffness

Simple Summary: The prediction of pancreatic neuroendocrine tumor (PNET) aggressiveness is important for treatment planning. The aim of this study was to evaluate the diagnostic performance of magnetic resonance elastography (MRE) with tomoelastography postprocessing (tomoelastography) in differentiating PNET from healthy pancreatic tissue and to correlate PNET stiffness with aggressiveness using asphericity derived from positron emission tomography (PET) as reference. In this prospective study we showed in a group of 13 patients with PNET that tomoelastography detected PNET by increased stiffness (p < 0.01) with a high diagnostic performance (AUC = 0.96). PNET was positively correlated with PET derived asphericity (r = 0.81). Tomoelastography provides quantitative imaging markers for the detection of PNET and the prediction of greater tumor aggressiveness by increased stiffness. Abstract: Purpose: To evaluate the diagnostic performance of tomoelastography in differentiating pancreatic neuroendocrine tumors (PNETs) from healthy pancreatic tissue and to assess the prediction of tumor aggressiveness by correlating PNET stiffness with PET derived asphericity. Methods: 13 patients with PNET were prospectively compared to 13 age-/sex-matched heathy volunteers (CTR). Multifrequency MR elastography was combined with tomoelastography-postprocessing to provide high-resolution maps of shear wave speed (SWS in m/s). SWS of pancreatic neuroendocrine tumor (PNET-T) were compared with nontumorous pancreatic tissue in patients with PNET (PNET-NT) and heathy pancreatic tissue (CTR). The diagnostic performance of tomoelastography was evaluated by ROC-AUC analysis. PNET-SWS correlations were calculated with Pearson’s r. Results: SWS was higher in PNET-T (2.02 ± 0.61 m/s) compared to PNET-NT (1.31 ± 0.18 m/s, p < 0.01) and CTR (1.26 ± 0.09 m/s, p < 0.01). An SWS-cutoff of 1.46 m/s distinguished PNET-T from PNET-NT (AUC = 0.89; sensitivity = 0.85; specificity = 0.92) and a cutoff of 1.49 m/s differentiated pancreatic tissue of CTR from PNET-T (AUC = 0.96; sensitivity = 0.92; specificity = 1.00). The SWS of PNET-T was positively correlated with PET derived asphericity (r = 0.81; p = 0.01). Conclusions: Tomoelastography provides quantitative imaging markers for the detection of PNET and the prediction of greater tumor aggressiveness by increased stiffness

Evaluation of the Electronic Resource Usage of Ankara University Faculty Members

Günümüzde üniversiteler, eğitim-öğretim, araştırma ve uygulama faaliyetleri içerisinde bulunabilmek için bilimsel bilgiye en doğru ve en hızlı biçimde ulaşmayı hedeflemektedir. Bundan dolayı, Ankara Üniversitesi akademik personelinin bilimsel bilgiye erişim için çağdaş bilgi ve iletişim teknolojilerini kullanması kaçınılmazdır. Bilimsel her veri tabanının standart taşıması gereken belirli özellikleri bulunmaktadır. Bu özellikler veri tabanında yer alan verilere erişimin doğru ve hızlı olması bakımından önem kazanmaktadır. Ankara Üniversitesi mensuplarına gereksinim duyacakları bilimsel bilgi kaynakları elektronik ortamda en çağdaş bilgi ve iletişim teknolojilerini kullanarak sunulmaktadır. Bu araştırmada, Ankara Üniversitesi akademik personelinin bilgi gereksinimleri doğrultusunda oluşturulan ve elektronik kütüphanede yer alan veri tabanlarının kullanılıp kullanılmadığının belirlenmesi amaçlanmış; bu amaca yönelik bilgi modeli ve içeriği belirlenerek uygulamaların gerçekleştirilmesi hedeflenmiştir.Education, research, and implementation activities of universities necessitate access to information in the most accurate and fastest manner in today's conditions. In this regard; Members of Ankara University have to access scientific information through the most contemporary information and communication technology in the electronic environment, primarily through the global internet system. Each scientific database has specific standard characteristics. These properties gain importance in terms of the correctness and speed of access to the data contained in the database. The sources of scientific information that the members of Ankara University will need are presented in the electronic environment using the most contemporary information and communication technologies. This article aims to determine the information needs of the members of Ankara University and to determine the information access and the use of information by identifying the information access model for researching the educational facilities and the necessary infrastructure and technical support so that the maximum benefit can be obtained from the electronic library. Aims at realizing their application by determining the information model and content for this purpose

EFFECT OF BEARING MACROGEOMETRY ON BEARING PERFORMANCE IN ELASTOHYDRODYNAMIC LUBRICATION

During manufacturing, ideal dimension and mutual positioning of machine elements proposed in project desing can be achieved only within certain range of tolerances. These tolerances, being classified in two groups, related to micro and macro geometry of machine elements, don't have to effect the functioning of these elements. So, as for all machine elements, investigation of the effects of macro and micro tolerances for journal bearings is important. In this study, we have investigated the effect of macro geometric irregularities of journal bearings on performance characteristics. In this regard, we have studied the change of bearing performance in respect to deviation from ideal circle for an elliptic shaft with small ovality rolling in circular journal bearing

Treatment of detrusor sphincter dyssynergia with baclofen and doxazosin

Detrusor sphincter dyssynergia (DSD) is an involuntary contraction of the external urethral sphincter during detrusor contraction. A high proportion of patients needing repeat surgery and long term failure have both been described in the literature. In the present study, we evaluated clinical characteristics, underlying disorders and outcomes of conservative medical treatment in 21 female patients. Two patients were newly diagnosed multiple sclerosis. Urodynamic studies were performed in all symptomatic patients, and consisted of measurement of post-micturition residuals, urethral pressure profilometry and EMG cystometry according to the criteria of the International Continence Society. All patients were treated with baclofen 15 mg/day and doxazosin 4 mg/day. Seven patients received tolterodine 4 mg/day in addition to baclofen and doxazocin because they had detrusor hyperreflexia (DH). In conclusion, treatment with either combined baclofen and doxazosin or anticholinergic agent tolterodine appeared to be effective. In addition, it should be kept in mind that DSD could be the first sign to any neurologic diseases

Detection of laryngeal tumors and tumoral extension by multislice computed tomography-virtual laryngoscopy (MSCT-VL)

Virtual endoscopy is becoming a widely used non-invasive clinical diagnostic tool. The present study was designed to compare the sensitivity and specificity of the conventional endoscopy and virtual laryngoscopy with respect to laryngeal masses. A total of 38 patients (20 males, 18 females, mean age 61 years) with the complaint of hoarseness were included in the study. Laryngeal mucosa, lumen and mass pathology were evaluated initially by direct endoscopy and then by virtual laryngoscopy during multislice CT of the larynx. Histopathologic evaluation of the masses was also made. The main pathology of the patients was found to be laryngeal masses (60% of patients, one mass for each patient), which were polyps (n = 8), papilloma (n = 4) and carcinoma (n = 11) according to histopathologic evaluation. Retrospective evaluation of 6 lesions detected in virtual but not in conventional laryngoscopy resulted with the finding of viscous-dense mucous secretion. On the contrary, three lesions detected by conventional laryngoscopy could not be detected by virtual evaluation. A total of six patients were evaluated and considered as normal both by conventional and virtual laryngoscopic examinations. Sensitivity of the virtual laryngoscopy was 88% (23/26) while its specificity was only 50% (6/12). Positive and negative predictive values were 79% (23/29) and 66% (6/9), respectively. Accuracy of the virtual laryngoscopy was 76% (29/38). Virtual laryngoscopy is not an alternative to conventional laryngoscopy but may assist direct endoscopy without causing additional radiation exposure or discomfort to the patient. The three-dimensional contribution to interpretation of the results and subsequent manipulation of the data can be used for educational and surgical purposes

First report of brown leaf spot caused by Alternaria alternata on Aronia melanocarpa in Turkey

[No Abstract Available

Unusual ventricular entrainment response: What is the mechanism?

WOS: 000464349700024PubMed ID: 31007802Entrainment is an important tool for the diagnosis and location of reentry. The usefulness of this maneuver requires that, prior to cessation of ventricular pacing, the atrial rate accelerates to the ventricular pacing rate. Moreover, it is important to verify the continuation of the tachycardia following cessation of entrainment. The recognizing the last entrained atrial beat is utmost important to avoid erroneous A-A-V labeling