Оптическая система установки для передачи единиц фотометрических величин

Представлений вибір та дослідження оптичної системи установки для калібруванняпо спектральній густині енергетичної яскравості прецизійних цифрових відеосистем, що працюють у видимій та ближній інфрачервоній областях спектру. Визначено оптимальне кутове положення оптичної системи згідно з аналізом аберацій.The present paper presents choose and research of optical system of devices for calibration of spectral radiance density of precise digital video systems working of visible and near infrared region. Optimum rotate angle of position of optical system accordant aberration analysis at schemes of control devices for measurement have been defined.Представленный выбор и исследование оптической системы установки для калибровки по спектральной плотности энергетической яркости прецизионных цифровых видеосистем, работающих в видимой и ближней инфракрасной областях спектра. Определено оптимальное угловое положение оптической системы согласно с анализом аберраций

Retina ray-tracing technique for eye-refraction mapping

ABSTRACT In photorefractive sight correction, pre-operational computations of to-be-ablated layers are usually based on information about cornea shape that is one of the causes of aberrations. To obtain high-quality results of operation, contributions to aberrations of other origins are to be taken into account. Technique of eye-aberration mapping has been investigated, we called retina ray-tracing. It consists in directing into the eye a narrow beam, scanned (translated) in parallel to itself. Computer controls trajectory of scanning. Beam projection (spot of light) is formed on the retina. Aberrations result in varying position of the spot on retina in the course of scanning. Deviations from initial position are measured and reconstructed into wave aberration function. Mathematical relations, using Zernike polynomial expansions, were found to transform these data into necessary cornea shape correction with ablation technologies. In our experimental setup, we used the technique of acousto-optic scanning with frame time less than 10 ms for 65 sensed points. Eye-aberration mapping is realized with optical power resolution 0.1 diopter

Forward ray tracing for image projection prediction and surface reconstruction in the evaluation of corneal topography systems

A forward ray tracing (FRT) model is presented to determine the exact image projection in a general corneal topography system. Consequently, the skew ray error in Placido-based topography is demonstrated. A quantitative analysis comparing FRT-based algorithms and Placido-based algorithms in reconstructing the front surface of the cornea shows that arc step algorithms are more sensitive to noise (imprecise). Furthermore, they are less accurate in determining corneal aberrations particularly the quadrafoil aberration. On the other hand, FRT-based algorithms are more accurate and more precise showing that point to point corneal topography is superior compared to its Placido-based counterpart

ВОЗМОЖНОСТИ ПОВТОРНОЙ ЛУЧЕВОЙ ТЕРАПИИ БОЛЬНЫХ С РЕЦИДИВОМ ПЛОСКОКЛЕТОЧНОГО РАКА ГОЛОВЫ И ШЕИ

Locoregional recurrence  is the most frequent cause of death of patients  with SCCHN. At present day clear guidance on the irradiation volume, total dose and timing of radiation re-treatment of these patients  are missing. 20 patients  with histologically confirmed locoregional recurrence  of HNSCC, received reirradiation. Median time after primary radiotherapy course was 37 months.  The treatment volumes and total doses were formed as follows: GTV (primary lesion and involved lymph nodes, delineated on CT, MRI and 18F-FDG PET-CT)+CTV (0,5–1,0 cm) + PTV (0,3–0,5 cm) was treated  to the total dose equivalent  to 66–70 Gy of conventional  fractionation,  the upper  neck (if indicated,  levels I–III+PTV 0,5 cm) to 60 Gy, the lower neck (if indicated,  levels IV–V+PTV 0,5 cm) — equivalent to 50 Gy. Single doses to these volumes were 2,14–2,21 Gy, 2,0 Gy and 1,8 Gy, respectively. Treatment was planned using IMRT and VMAT techniques with SIB (Simultaneously Integrated Boost). Daily positioning  inaccuracy was less than 3 mm at lymph nodes PTV and less than 1 mm in OARs of CNS and optic pathways. 19 of 20 patients  received full course of radiation therapy without a break. Radiation toxicity manifested with grade 2 oral and pharyngeal mucositis and grade 2 radiation epidermitis. Relief time of radiation mucositis and dermatitis was the same to primary radiotherapy course. Oneyear OS was 48%. Using technique of SIB with IMRT and VMAT during curative reirradiation of recurrent HNSCC is available with maintaining  satisfactory tolerability.Локорегионарный рецидив является наиболее частой причиной гибели больных ПРГШ.  Четкие рекомендации относительно  объемов  облучения,  суммарных доз  и  сроков  повторного  лучевого  лечения  этих  пациентов на сегодняшний день отсутствуют. Повторное облучение проведено 20 пациентам с рецидивом ПРГШ. Медиана времени  между курсами ЛТ составила  37  мес. Объемы  облучения и предписание суммарных очаговых доз (СОД) формировались следующим образом: первичный очаг (GTV+0,5–1,0 см CTV+0,3 см PTV) — СОД экв. 70 Гр; лимфатические узлы шеи высокого риска (CTV+0,5 см PTV) — СОД экв. 60 Гр: лимфоузлы шеи низкого риска (CTV+0,5 см PTV) — СОД экв. 51 Гр. Разовые  дозы составили 2,12–2,23 Гр, 2,0 Гр и 1,7–1,8 Гр соответственно. Оконтуривание GTV первичной опухоли проводилось по данным КТ, МРТ и ПЭТ-КТ  с 18F-ФДГ, выполненных в лечебном  положении  пациента.  При  дозиметрическом планировании  использовалась  IMRT и VMAT в режиме одновременно интегрированного буста (SIB). Ежедневная  погрешность укладки составила 3 мм в области регионарных лимфоузлов, 1 мм в области критических структур ЦНС (зрительные  нервы и их перекрест,  ствол мозга, спинной мозг). Без перерыва курс облучения удалось провести 19 больным. Местные лучевые реакции проявлялись в виде мукозита и дерматита II степени. Одному пациенту потребовался перерыв на 7 дней в связи мукозитом III степени. Продолжительность ранних лучевых реакций не отличалась от таковых при первичном облучении. Медиана наблюдения за больными составила 11 мес. Общая  однолетняя выживаемость с момента повторного облучения — 48%. Использование методики IMRT и VMAT с одновременно интегрированным бустом позволяет  подвести радикальные СОД  при удовлетворительной переносимости лечения

Fitness of Escherichia coli during Urinary Tract Infection Requires Gluconeogenesis and the TCA Cycle

Microbial pathogenesis studies traditionally encompass dissection of virulence properties such as the bacterium's ability to elaborate toxins, adhere to and invade host cells, cause tissue damage, or otherwise disrupt normal host immune and cellular functions. In contrast, bacterial metabolism during infection has only been recently appreciated to contribute to persistence as much as their virulence properties. In this study, we used comparative proteomics to investigate the expression of uropathogenic Escherichia coli (UPEC) cytoplasmic proteins during growth in the urinary tract environment and systematic disruption of central metabolic pathways to better understand bacterial metabolism during infection. Using two-dimensional fluorescence difference in gel electrophoresis (2D-DIGE) and tandem mass spectrometry, it was found that UPEC differentially expresses 84 cytoplasmic proteins between growth in LB medium and growth in human urine (P<0.005). Proteins induced during growth in urine included those involved in the import of short peptides and enzymes required for the transport and catabolism of sialic acid, gluconate, and the pentose sugars xylose and arabinose. Proteins required for the biosynthesis of arginine and serine along with the enzyme agmatinase that is used to produce the polyamine putrescine were also up-regulated in urine. To complement these data, we constructed mutants in these genes and created mutants defective in each central metabolic pathway and tested the relative fitness of these UPEC mutants in vivo in an infection model. Import of peptides, gluconeogenesis, and the tricarboxylic acid cycle are required for E. coli fitness during urinary tract infection while glycolysis, both the non-oxidative and oxidative branches of the pentose phosphate pathway, and the Entner-Doudoroff pathway were dispensable in vivo. These findings suggest that peptides and amino acids are the primary carbon source for E. coli during infection of the urinary tract. Because anaplerosis, or using central pathways to replenish metabolic intermediates, is required for UPEC fitness in vivo, we propose that central metabolic pathways of bacteria could be considered critical components of virulence for pathogenic microbes

The Bacterial Fimbrial Tip Acts as a Mechanical Force Sensor

The subunits that constitute the bacterial adhesive complex located at the tip of the fimbria form a hook-chain that acts as a rapid force-sensitive anchor at high flow

Positive Signature-Tagged Mutagenesis in Pseudomonas aeruginosa: Tracking Patho-Adaptive Mutations Promoting Airways Chronic Infection

The opportunistic pathogen Pseudomonas aeruginosa can establish life-long chronic infections in the airways of cystic fibrosis (CF) patients. Persistent lifestyle is established with P. aeruginosa patho-adaptive variants, which are clonal with the initially-acquired strains. Several reports indicated that P. aeruginosa adapts by loss-of-function mutations which enhance fitness in CF airways and sustain its clonal expansion during chronic infection. To validate this model of P. aeruginosa adaptation to CF airways and to identify novel genes involved in this microevolution, we designed a novel approach of positive-selection screening by PCR-based signature-tagged mutagenesis (Pos-STM) in a murine model of chronic airways infection. A systematic positive-selection scheme using sequential rounds of in vivo screenings for bacterial maintenance, as opposed to elimination, generated a list of genes whose inactivation increased the colonization and persistence in chronic airways infection. The phenotypes associated to these Pos-STM mutations reflect alterations in diverse aspects of P. aeruginosa biology which include lack of swimming and twitching motility, lack of production of the virulence factors such as pyocyanin, biofilm formation, and metabolic functions. In addition, Pos-STM mutants showed altered invasion and stimulation of immune response when tested in human respiratory epithelial cells, indicating that P. aeruginosa is prone to revise the interaction with its host during persistent lifestyle. Finally, sequence analysis of Pos-STM genes in longitudinally P. aeruginosa isolates from CF patients identified signs of patho-adaptive mutations within the genome. This novel Pos-STM approach identified bacterial functions that can have important clinical implications for the persistent lifestyle and disease progression of the airway chronic infection

Uropathogenic Escherichia coli P and Type 1 Fimbriae Act in Synergy in a Living Host to Facilitate Renal Colonization Leading to Nephron Obstruction

The progression of a natural bacterial infection is a dynamic process influenced by the physiological characteristics of the target organ. Recent developments in live animal imaging allow for the study of the dynamic microbe-host interplay in real-time as the infection progresses within an organ of a live host. Here we used multiphoton microscopy-based live animal imaging, combined with advanced surgical procedures, to investigate the role of uropathogenic Escherichia coli (UPEC) attachment organelles P and Type 1 fimbriae in renal bacterial infection. A GFP+ expressing variant of UPEC strain CFT073 and genetically well-defined isogenic mutants were microinfused into rat glomerulus or proximal tubules. Within 2 h bacteria colonized along the flat squamous epithelium of the Bowman's capsule despite being exposed to the primary filtrate. When facing the challenge of the filtrate flow in the proximal tubule, the P and Type 1 fimbriae appeared to act in synergy to promote colonization. P fimbriae enhanced early colonization of the tubular epithelium, while Type 1 fimbriae mediated colonization of the center of the tubule via a mechanism believed to involve inter-bacterial binding and biofilm formation. The heterogeneous bacterial community within the tubule subsequently affected renal filtration leading to total obstruction of the nephron within 8 h. Our results reveal the importance of physiological factors such as filtration in determining bacterial colonization patterns, and demonstrate that the spatial resolution of an infectious niche can be as small as the center, or periphery, of a tubule lumen. Furthermore, our data show how secondary physiological injuries such as obstruction contribute to the full pathophysiology of pyelonephritis

Genomic variation landscape of the human gut microbiome

While large-scale efforts have rapidly advanced the understanding and practical impact of human genomic variation, the latter is largely unexplored in the human microbiome. We therefore developed a framework for metagenomic variation analysis and applied it to 252 fecal metagenomes of 207 individuals from Europe and North America. Using 7.4 billion reads aligned to 101 reference species, we detected 10.3 million single nucleotide polymorphisms (SNPs), 107,991 short indels, and 1,051 structural variants. The average ratio of non-synonymous to synonymous polymorphism rates of 0.11 was more variable between gut microbial species than across human hosts. Subjects sampled at varying time intervals exhibited individuality and temporal stability of SNP variation patterns, despite considerable composition changes of their gut microbiota. This implies that individual-specific strains are not easily replaced and that an individual might have a unique metagenomic genotype, which may be exploitable for personalized diet or drug intake