ТОВАРИСЬКИЙ ГУРТОК ІНЖЕНЕРІВ КАТЕРИНОСЛАВСЬКОГО РАЙОНУ: СТВОРЕННЯ, ВІДКРИТТЯ Й ПЕРШІ РОКИ ДІЯЛЬНОСТІ (1908-1910 РР.)

Досліджено історію створення та відкриття Товариського гуртка інженерів Катеринославського регіону (ТГІКр).(ТГІКр).; The history of creation and opening of Yekaterinoslav engineers group (YEG) is investigated

Regulierung in Telekommunikationsmärkten: Technologische Dynamik und Wettbewerbspotential

Moderne Kommunikationsnetze tragen zur Verbreitung von Wissen und Information bei und sind daher für die wirtschaftliche Entwicklung von Industrienationen wie Deutschland von zentraler Bedeutung. Insbesondere stellt der Umbau der Netzarchitektur vom traditionellen vermittelten Sprachtelefonnetz zum IP-basierten Datennetz zur Bewältigung aktueller und zukünftiger Datenaufkommen eine besondere Herausforderung, aber auch Chance für die beteiligten Akteure dar. Aus einer technologisch-ökonomischen Perspektive werden in diesem Beitrag die Wettbewerbspotentiale sowie die Rolle einer sektorspezifischen Regulierung in diesem Transformationsprozess analysiert. Dabei folgt die Argumentation der Einsicht, dass neue Wettbewerber nur in einen wachsenden Markt eintreten. Neue infrastrukturbasierte Wettbewerber müssen jedoch frühzeitig die Möglichkeit bekommen, sich Marktanteile im wachsenden Markt für Datentransport zu sichern. Aufgrund des sukzessiven Übergangs zum IP-basierten Datennetz hat Regulierung die Aufgabe, neuen Wettbewerbern den Zugang zu Elementen des traditionellen Netzes des etablierten Anbieters zu gewährleisten. Die Regulierung des Zugangs zu neuen Zugangsnetzen lässt sich dagegen nur in dünn besiedelten Regionen begründen, in denen aufgrund der hohen Aufbaukosten und der geringen Nachfrage kein infrastrukturbasierter Wettbewerb zu erwarten ist. In diesem Fall könnte sich die öffentliche Hand auch an der Finanzierung des Netzes beteiligen, um die Entstehung des Netzes selbst sicherzustellen. In Agglomerationsräumen schafft dagegen der Wettbewerb zwischen wenigen Kopf-an-Kopf-Wettbewerbern Anreize zur Investitionen in neue Zugangsnetze.Telekommunikation, Wettbewerb, Regulierung, Telekommunikationsnetz, Markt, Infomationstechnik, Deutschland

Monitoring of cerebral blood flow during hypoxia-ischemia and resuscitation in the neonatal rat using laser speckle imaging

Neonatal hypoxic‐ischemic encephalopathy (HIE) is associated with alterations in cerebral blood flow (CBF) as a result of perinatal asphyxia. The extent to which CBF changes contribute to injury, and whether treatments that ameliorate these changes might be neuroprotective, is still unknown. Higher throughput techniques to monitor CBF changes in rodent models of HIE can help elucidate the underlying pathophysiology. We developed a laser speckle imaging (LSI) technique to continuously monitor CBF in six postnatal‐day 10 (P10) rats simultaneously before, during, and after unilateral hypoxia‐ischemia (HI, ligation of the left carotid artery followed by hypoxia in 8% oxygen). After ligation, CBF to the ligated side fell by 30% compared to the unligated side (P < 0.0001). Hypoxia induced a bilateral 55% reduction in CBF, which was partially restored by resuscitation. Compared to resuscitation in air, resuscitation in 100% oxygen increased CBF to the ligated side by 45% (P = 0.033). Individual variability in CBF response to hypoxia between animals accounted for up to 24% of the variability in hemispheric area loss to the ligated side. In both P10 and P7 models of unilateral HI, resuscitation in 100% oxygen did not affect hemispheric area loss, or hippocampal CA1 pyramidal neuron counts, after 1‐week survival. Continuous CBF monitoring using LSI in multiple rodents simultaneously can screen potential treatment modalities that affect CBF, and provide insight into the pathophysiology of HI

Diagnostic Confidence of Run-Off CT-Angiography as the Primary Diagnostic Imaging Modality in Patients Presenting with Acute or Chronic Peripheral Arterial Disease

Objectives To investigate the reliability of CT-angiography of the lower extremities (run-off CTA) to derive a treatment decision in patients with acute and chronic peripheral artery disease (PAD). Materials and Methods 314 patients referred for run-off CTA were includ-ed in this retrospective study. First, diagnostic confidence of run-off CTA to derive a treat-ment decision was assessed in an interdisciplinary vascular conference using a 2 point scale (sufficient or not sufficient diagnostic confidence) and compared with the image quality eval-uated by two readers in consensus in four different levels (abdominopelvic, thigh, calf, foot arteries). Second, reliability of treatment decision was verified in all patients undergoing re-vascularization therapy. Results Diagnostic confidence of run-off CTA to derive a treatment deci-sion was sufficient in all patients with acute and in 97% of patients (215/221) with chronic PAD, whereas the rate of run-off CTA with non-diagnostic image quality was considerably higher in the calf and foot level (acute vs. chronic; calf: 28% vs.17%; foot: 52% vs. 20%). Reliability of treatment decision was superior for patients with chronic (123/133 = 92%) than for patients with acute PAD (64/78 = 82%, P = 0.02). Conclusion Run-off CTA is a reliable imaging modality for primary diag-nostic work-up of patients with acute and chronic PAD

Treatment temperature and insult severity influence the neuroprotective effects of therapeutic hypothermia

Therapeutic hypothermia (HT) is standard care for moderate and severe neonatal hypoxic-ischaemic encephalopathy (HIE), the leading cause of permanent brain injury in term newborns. However, the optimal temperature for HT is still unknown, and few preclinical studies have compared multiple HT treatment temperatures. Additionally, HT may not benefit infants with severe encephalopathy. In a neonatal rat model of unilateral hypoxia-ischaemia (HI), the effect of five different HT temperatures was investigated after either moderate or severe injury. At postnatal-day seven, rat pups underwent moderate or severe HI followed by 5 h at normothermia (37 °C), or one of five HT temperatures: 33.5 °C, 32 °C, 30 °C, 26 °C, and 18 °C. One week after treatment, neuropathological analysis of hemispheric and hippocampal area loss, and CA1 hippocampal pyramidal neuron count, was performed. After moderate injury, a significant reduction in hemispheric and hippocampal loss on the injured side, and preservation of CA1 pyramidal neurons, was seen in the 33.5 °C, 32 °C, and 30 °C groups. Cooling below 33.5 °C did not provide additional neuroprotection. Regardless of treatment temperature, HT was not neuroprotective in the severe HI model. Based on these findings, and previous experience translating preclinical studies into clinical application, we propose that milder cooling should be considered for future clinical trials

Optical conductivity of CuO_2 infinite-layer films

The infrared conductivity of CaCuO_2, SrCuO_{2-y}, and Sr_{0.85}Nd_{0.15}CuO_2 infinite-layer films is obtained from reflectivity measurements by taking into account the substrate contribution. SrCuO_{2-y} and Sr_{0.85}Nd_{0.15}CuO_2 exhibit extra-phonon modes and structured bands in the midinfrared, not found in stoichiometric CaCuO_2. These features mirror those observed in the perovskitic cuprates, thus showing that the polaronic properties of high-T_c superconductors are intrinsic to the CuO_2 planes.Comment: File latex, 5 p. incl. 4 fig. in epsf. Submitted to Solid State Com

Lung tumour growth kinetics in SPC-c-Raf-1-BB transgenic mice assessed by longitudinal in-vivo micro-CT quantification

<p>Abstract</p> <p>Background</p> <p>SPC-c-Raf-1-BxB transgenic mice develop genetically induced disseminated lung adenocarcinoma allowing examination of carcinogenesis and evaluation of novel treatment strategies. We report on assessment of lung tumour growth kinetics using a semiautomated region growing segmentation algorithm.</p> <p>Methods</p> <p>156 non contrast-enhanced respiratory gated micro-CT of the lungs were obtained in 12 SPC-raf transgenic (n = 9) and normal (n = 3) mice at different time points. Region-growing segmentation of the aerated lung areas was obtained as an inverse surrogate for tumour burden. Time course of segmentation volumes was assessed to demonstrate the potential of the method for follow-up studies.</p> <p>Results</p> <p>Micro-CT allowed assessment of tumour growth kinetics and semiautomated region growing enabled quantitative analysis. Significant changes of the segmented lung volumes over time could be shown (<it>p </it>= 0.009). Significant group differences could be detected between transgenic and normal animals for time points 8 to 13 months (<it>p </it>= 0.043), when marked tumour progression occurred.</p> <p>Conclusion</p> <p>The presented region-growing segmentation algorithm allows in-vivo quantification of multifocal lung adenocarcinoma in SPC-raf transgenic mice. This enables the assessment of tumour load and progress for the study of carcinogenesis and the evaluation of novel treatment strategies.</p