Local and average fields inside surface-disordered waveguides: Resonances in the one-dimensional Anderson localization regime

We investigate the one-dimensional propagation of waves in the Anderson localization regime, for a single-mode, surface disordered waveguide. We make use of both an analytical formulation and rigorous numerical simulation calculations. The occurrence of anomalously large transmission coefficients for given realizations and/or frequencies is studied, revealing huge field intensity concentration inside the disordered waveguide. The analytically predicted s-like dependence of the average intensity, being in good agreement with the numerical results for moderately long systems, fails to explain the intensity distribution observed deep in the localized regime. The average contribution to the field intensity from the resonances that are above a threshold transmission coefficient $T_{c}$ is a broad distribution with a large maximum at/near mid-waveguide, depending universally (for given $T_{c}$) on the ratio of the length of the disorder segment to the localization length, $L/\xi$. The same universality is observed in the spatial distribution of the intensity inside typical (non-resonant with respect to the transmission coefficient) realizations, presenting a s-like shape similar to that of the total average intensity for $T_{c}$ close to 1, which decays faster the lower is $T_{c}$. Evidence is given of the self-averaging nature of the random quantity $\log[I(x)]/x\simeq -1/\xi$. Higher-order moments of the intensity are also shown.Comment: 9 pages, 9 figure

Effect of low extracellular pH on NF-κB activation in macrophages

Objective: Many diseases, including atherosclerosis, involve chronic inflammation. The master transcription factor for inflammation is NF-κB. Inflammatory sites have a low extracellular pH. Our objective was to demonstrate the effect of pH on NF-κB activation and cytokine secretion. Methods: Mouse J774 macrophages or human THP-1 or monocyte-derived macrophages were incubated at pH 7.0–7.4 and inflammatory cytokine secretion and NF-κB activity were measured. Results: A pH of 7.0 greatly decreased pro-inflammatory cytokine secretion (TNF or IL-6) by J774 macrophages, but not THP-1 or human monocyte-derived macrophages. Upon stimulation of mouse macrophages, the levels of IκBα, which inhibits NF-κB, fell but low pH prevented its later increase, which normally restores the baseline activity of NF-κB, even though the levels of mRNA for IκBα were increased. pH 7.0 greatly increased and prolonged NF-κB binding to its consensus promoter sequence, especially the anti-inflammatory p50:p50 homodimers. Human p50 was overexpressed using adenovirus in THP-1 macrophages and monocyte-derived macrophages to see if it would confer pH sensitivity to NF-κB activity in human cells. Overexpression of p50 increased p50:p50 DNA-binding and in THP-1 macrophages inhibited considerably TNF and IL-6 secretion, but there was still no effect of pH on p50:p50 DNA binding or cytokine secretion. Conclusion: A modest decrease in pH can sometimes have marked effects on NF-κB activation and cytokine secretion and might be one reason to explain why mice normally develop less atherosclerosis than do humans

A Methodology for Real-Time 3D Visualization of Asphalt Thermal Behaviour During Road Construction

Asphalt mixture temperature plays an essential role in the road construction process. For high-quality asphalt, it is crucial that the compaction is performed within a certain range of the temperature, known as the compaction window. The compaction of the asphalt at a temperature outside this range would compromise the quality of the final product considerably. The compaction window is predicated on a myriad of parameters such as the type of the asphalt mix, the ambient temperature, etc. However, the operators of the road construction equipment (e.g., rollers and pavers) currently rely on their professional intuitions and experiences to develop their operational strategies. This practice can be significantly improved if the operators can be provided with the real-time information about the temperature of the asphalt mat during the construction. The available solutions for the real-time monitoring of the asphalt are limited to capturing and presenting only the surface temperature or only core temperature of the asphalt mat. Given the complex behaviour of the asphalt with relation to the mixture type and the ambient conditions, this approach cannot best represent the asphalt behaviour during the construction. This paper presents an approach for capturing the real-time asphalt behaviour using multiple sensing technologies. In this approach, the core and surface temperatures of the asphalt are captured using thermologger and linescanner, respectively. These data are then translated into 3D temperature contour plots that represent the asphalt behaviour under the construction site settings in real time. Finally, the data is presented to the equipment operator via a user interface. A prototype is developed and tested to demonstrate the feasibility of the proposed approach. The case study indicates that the presented method can improve the asphalt operation by enabling the operators to better develop their operational strategies

Повторные операции после коррекции частичного аномального дренажа. Серия клинических наблюдений

Rationale: The surgical procedure for partial abnormal pulmonary venous return (PAPV) implies the formation of a tunnel between the orifices of the right pulmonary veins and the left atrial cavity with the interatrial septum repair. To avoid any obstruction of the tunnel, a direct anastomosis between the superior vena cava (SVC) and the right atrial appendage is placed in a number of cases. However, the reparative procedure is potentially associated with such complications as SVC stenosis and/or pulmonary vein stenosis. Aim: To present our experience of reoperations for stenosis of systemic and pulmonary veins after primary PAPV repair. Materials and methods: From 2014 to 2018, seven patients (boys, 4) with SVC stenosis and/or with stenosis of the right pulmonary veins have been admitted to the FCHMT (Kaliningrad). Their mean bodyweight was 29.1 kg (± 12.5 kg), mean age 9.3 years (± 3.6 years). Three patients had an isolated SVC stenosis. In two patients, there was a combination of SVC stenosis and pulmonary vein obstruction (from stenosis to complete occlusion); in one patient the right pulmonary vein stenosis had been caused by thrombosis. SVC stenosis with subaortal obstruction after the repair of double-outlet right ventricle was diagnosed in one case. In six patients, various procedures for correction of SVC and/or pulmonary vein stenosis were performed. Only in one case the obstruction of systemic veins, confirmed by cardiac catheterization, turned out to be non-significant, making a reoperation unnecessary. Results: There were no deaths in this patient group. Endovascular procedures were performed in two patients. In one case, there was an unsuccessful attempt of transluminal balloon angioplasty for SVC stenosis, with subsequent Warden procedure. In another case, a 16-year old patient with SVC stenosis and high pulmonary hypertension was admitted after two previous surgeries had failed. We used a homograft as SVC prosthesis; however, after one year, a re-stenosis was identified. In this case, a SVC stent placement was successful. Due to sick sinus syndrome at one year after the Warden procedure and the repair of pulmonary veins by a homograft, an implantation of electric cardiac pacemaker was necessary in one patient. Conclusion: The curative repair of partial abnormal venous return is a well-established surgical technique with satisfactory shortand long-term results. A potential complication of the procedure is an obstruction of systemic and pulmonary veins. To prevent such complications during primary defect repair, as well as with reoperations for vein stenosis, the Warden procedure seems effective and highly reproducible technique associated with lower surgical risks.Актуальность. Хирургическая методика коррекции частичного аномального дренажа легочных вен (ЧАДЛВ) заключается в формировании тоннеля между устьями правых легочных вен и полостью левого предсердия при пластике дефекта межпредсердной перегородки. Чтобы избежать обструкции тоннеля, в ряде случаев выполняется прямой анастомоз верхней полой вены (ВПВ) с ушком правого предсердия. Однако после коррекции порока возможны такие осложнения, как стеноз ВПВ и/или стеноз легочных вен. Цель – представить опыт повторных операций при стенозах системных и легочных вен после первичной коррекции ЧАДЛВ. Материал и методы. С 2014 по 2018 г. в центр поступили 7 пациентов со стенозом ВПВ и/или стенозом правых легочных вен (4 из них были мальчики). Средний вес пациентов составил 29,1 кг (± 12,5 кг), средний возраст – 9,3 года (± 3,6 года). Изолированный стеноз ВПВ был у 3 пациентов. У 2 пациентов стеноз ВПВ сочетался с обструкцией легочных вен (от стеноза до полной окклюзии), а в 1 наблюдении стеноз правых легочных вен был обусловлен их тромбозом. Стеноз ВПВ в сочетании с подаортальной обструкцией после коррекции двойного отхождения сосудов от правого желудочка был диагностирован в 1 наблюдении. Шестерым пациентам были выполнены различные операции с целью коррекции стенозов ВПВ и/или легочных вен. Только в 1 случае обструкция системных вен, подтвержденная данными внутрисердечного исследования, оказалась незначительной, и повторное хирургическое вмешательство не потребовалось. Результаты. Летальных исходов в нашей группе пациентов не было. Эндоваскулярные процедуры были выполнены 2 пациентам. В 1 случае попытка транслюминальной баллонной ангиопластики стеноза ВПВ оказалась неудачной, в результате была выполнена операция Warden. В другом наблюдении пациент 16 лет после двух предшествующих операций поступил к нам со стенозом ВПВ и высокой легочной гипертензией. Для протезирования ВПВ мы использовали гомографт, однако через год был диагностирован рестеноз ВПВ. Предпринятая в этом случае имплантация стента в ВПВ оказалась успешной. По причине синдрома слабости синусового узла через год после операции Warden и пластики легочных вен гомографтом потребовалась имплантация постоянной электрокардиостимулирующей системы у 1 пациента. Заключение. Радикальная коррекция частичного аномального дренажа – хорошо отработанная хирургическая методика, характеризующаяся удовлетворительными результатами в ближайшем и отдаленном периодах после операции. Наличие обструкции системных и легочных вен является возможным осложнением коррекции. Для профилактики подобных осложнений при первичной коррекции порока, а также в случаях повторных оперативных вмешательств при наличии стеноза вен методика, предложенная Warden, представляется эффективной, хорошо воспроизводимой процедурой, сопряженной с меньшими хирургическими рисками