Integrated III-V Photonic Crystal - Si waveguide platform with tailored optomechanical coupling

Optomechanical systems, in which the vibrations of a mechanical resonator are coupled to an electromagnetic radiation, have permitted the investigation of a wealth of novel physical effects. To fully exploit these phenomena in realistic circuits and to achieve different functionalities on a single chip, the integration of optomechanical resonators is mandatory. Here, we propose a novel approach to heterogeneously integrate arrays of two-dimensional photonic crystal defect cavities on top of silicon-on-insulator waveguides. The optomechanical response of these devices is investigated and evidences an optomechanical coupling involving both dispersive and dissipative mechanisms. By controlling the optical coupling between the waveguide and the photonic crystal, we were able to vary and understand the relative strength of these couplings. This scalable platform allows for an unprecedented control on the optomechanical coupling mechanisms, with a potential benefit in cooling experiments, and for the development of multi-element optomechanical circuits in the framework of optomechanically-driven signal-processing applications

An insight into polarization states of solid-state organic lasers

The polarization states of lasers are crucial issues both for practical applications and fundamental research. In general, they depend in a combined manner on the properties of the gain material and on the structure of the electromagnetic modes. In this paper, we address this issue in the case of solid-state organic lasers, a technology which enables to vary independently gain and mode properties. Different kinds of resonators are investigated: in-plane micro-resonators with Fabry-Perot, square, pentagon, stadium, disk, and kite shapes, and external vertical resonators. The degree of polarization P is measured in each case. It is shown that although TE modes prevail generally (P>0), kite-shaped micro-laser generates negative values for P, i.e. a flip of the dominant polarization which becomes mostly TM polarized. We at last investigated two degrees of freedom that are available to tailor the polarization of organic lasers, in addition to the pump polarization and the resonator geometry: upon using resonant energy transfer (RET) or upon pumping the laser dye to an higher excited state. We then demonstrate that significantly lower P factors can be obtained.Comment: 12 pages, 12 figure

The state of specific immunity of population of the Republic of Tajikistan to measles, rubella, poliomyelitis viruses

Relevance. To achieve the goals of measles and rubella elimination and poliomyelitis eradication programs, immunization coverage of at least 95% of the target population is required. Objective data on the state of specific herd immunity are provided only by the results of serosurveys. In the Republic of Tajikistan, such monitoring is not carried out regularly. Therefore, the purpose of the study was to assess the actual state of the specific herd immunity to measles, rubella, and poliomyelitis viruses. Materials and methods. The blood sera of 563 children and adults collected in 7 cities and 13 districts of Tajikistan in 2020 were investigated. The level of antibodies (ABs) to measles and rubella viruses was determined using enzyme immunoassay. Test systems VectoKor-IgG (VECTOR-BEST, Russia) and Ecolab, Russia were used to determine ABs to measles and rubella virus, respectively. Neutralizing antibodies (nABs) to the 3 types of poliovirus (PV) were determined in 359 sera using a neutralization reaction with Sabin strains of types 1, 2, 3. Results. The conducted serosurvey showed the level of the specific herd immunity to rubella to be 87.9% in total population, including 86.2% in children, 93.1% in adolescents, and 93.5% and adults, that is sufficient to prevent transmission of the rubella virus. The proportion of individuals seropositive to measles was 54.5%, which is not enough to prevent sustained secondary transmission of infection and the resumption of circulation of the endemic strain of measles virus. The children under 15 years of age should be considered a population at risk of the infection, since children accounted for 38% among seronegative individuals. In general, less than 95% of the examined patients had nABs to PV: 94.4% to PV1, 86.1% to PV2, 83.6% to PV3; 3.3% did not have antibodies to all three types of PV. The level of herd immunity varied in the examined groups depending on the vaccination schedule and the composition of the poliovirus vaccines used: nABs to PV2 had 59.6% of children born during the period when vaccines containing PV2 were not used, and 85.7% of children born after the introduction of trivalent IPV. Deficiency in immunity to PV2 was the cause of a polio outbreak in 2021 caused by circulating vaccine-derived PV type 2. Conclusion. A high level of humoral immunity to the rubella virus was determined. Shortcomings of routine immunization against measles and polio associated with insufficient coverage and lack of IPV have been identified. Conducting regular serological monitoring in the Republic of Tajikistan is advisable to obtain objective information about the level of herd immunity, identify vulnerable groups of the population, and plan additional immunization activities

Computational optical imaging with a photonic lantern

[EN] The thin and flexible nature of optical fibres often makes them the ideal technology to view biological processes in-vivo, but current microendoscopic approaches are limited in spatial resolution. Here, we demonstrate a route to high resolution microendoscopy using a multicore fibre (MCF) with an adiabatic multimode-to-single-mode "photonic lantern" transition formed at the distal end by tapering. We show that distinct multimode patterns of light can be projected from the output of the lantern by individually exciting the single-mode MCF cores, and that these patterns are highly stable to fibre movement. This capability is then exploited to demonstrate a form of single-pixel imaging, where a single pixel detector is used to detect the fraction of light transmitted through the object for each multimode pattern. A custom computational imaging algorithm we call SARA-COIL is used to reconstruct the object using only the pre-measured multimode patterns themselves and the detector signals.This work was funded through the "Proteus" Engineering and Physical Sciences Research Council (EPSRC) Interdisciplinary Research Collaboration (IRC) (EP/K03197X/1), by the Science and Technology Facilities Council (STFC) through STFC-CLASP grants ST/K006509/1 and ST/K006460/1, STFC Consortium grants ST/N000625/1 and ST/N000544/1. S.L. acknowledges support from the National Natural Science Foundation of China under Grant no. 61705073. DBP acknowledges support from the Royal Academy of Engineering, and the European Research Council (PhotUntangle, 804626). The authors thank Philip Emanuel for the use of his confocal image of A549 cells and Eckhardt Optics for their image of the USAF 1951 target. The authors sincerely thank the anonymous reviewers of this paper for their detailed and considered feedback which helped us to improve the quality of this paper significantly.Choudhury, D.; Mcnicholl, DK.; Repetti, A.; Gris-Sánchez, I.; Li, S.; Phillips, DB.; Whyte, G.... (2020). Computational optical imaging with a photonic lantern. Nature Communications. 11(1):1-9. https://doi.org/10.1038/s41467-020-18818-6S19111Wood, H. A. C., Harrington, K., Birks, T. A., Knight, J. C. & Stone, J. M. High-resolution air-clad imaging fibers. Opt. Lett. 43, 5311–5314 (2018).Akram, A. R. et al. In situ identification of Gram-negative bacteria in human lungs using a topical fluorescent peptide targeting lipid A. Sci. Transl. Med. 10, eaal0033 (2018).Shin, J., Bosworth, B. T. & Foster, M. A. Compressive fluorescence imaging using a multi-core fiber and spatially dependent scattering. Opt. Lett. 42, 109–112 (2017).Papadopoulos, I. N., Farahi, S., Moser, C. & Psaltis, D. Focusing and scanning light through a multimode optical fiber using digital phase conjugation. Opt. Express 20, 10583–10590 (2012).Čižmár, T. & Dholakia, K. Exploiting multimode waveguides for pure fibre-based imaging. Nat. Commun. 3, 1027 (2012).Plöschner, M., Tyc, T. & Čižmár, T. Seeing through chaos in multimode fibres. Nat. Photon. 9, 529–535 (2015).Birks, T. A., Gris-Sánchez, I., Yerolatsitis, S., Leon-Saval, S. G. & Thomson, R. R. The photonic lantern. Adv. Opt. Photon. 7, 107–167 (2015).Birks, T. A., Mangan, B. J., Díez, A., Cruz, J. L. & Murphy, D. F. Photonic lantern’ spectral filters in multi-core fiber. Opt. Express 20, 13996–14008 (2012).Edgar, M. P., Gibson, G. M. & Padgett, M. J. Principles and prospects for single-pixel imaging. Nat. Photon. 13, 13–20 (2019).Mahalati, R. N., Yu, Gu. R. & Kahn, J. M. Resolution limits for imaging through multi-mode fiber. Opt. Express 21, 1656–1668 (2013).Amitonova, L. V. & de Boer, J. F. Compressive imaging through a multimode fiber. Opt. Lett. 43, 5427–5430 (2018).Mallat, S. A Wavelet Tour of Signal Processing 2nd edn (Academic Press, Burlington, MA, 2009).Lustig, M., Donoho, D. & Pauly, J. M. Sparse MRI: the application of compressed sensing for rapid MR imaging. Magn. Reson. Med. 58, 1182–1195 (2007).Davies, M., Puy, G., Vandergheynst, P. & Wiaux, Y. A compressed sensing framework for magnetic resonance fingerprinting. SIAM J. Imaging Sci. 7, 2623–2656 (2014).Wiaux, Y., Puy, G., Scaife, A. M. M. & Vandergheynst, P. Compressed sensing imaging techniques in radio interferometry. Mon. Not. R. Astron. Soc. 395, 1733–1742 (2009).Carrillo, R. E., McEwen, J. D. & Wiaux, Y. Sparsity averaging reweighted analysis (SARA): a novel algorithm for radio-interferometric imaging. Mon. Not. R. Astron. Soc. 426, 1223–1234 (2012).Katz, O., Bromberg, Y. & Silberberg, Y. Compressive ghost imaging. Appl. Phys. Lett. 95, 131110 (2009).Sun, B., Welsh, S. S., Edgar, M. P., Shapiro, J. H. & Padgett, M. J. Normalized ghost imaging. Opt. Express 20, 16892–16901 (2012).Kim, M., Park, C., Rodriguez, C., Park, Y. & Cho, Y.-H. Superresolution imaging with optical fluctuation using speckle patterns illumination. Sci. Rep. 5, 16525 (2015).Combettes, P. L. & Pesquet, J. -C. in Fixed-Point Algorithms for Inverse Problems in Science and Engineering (Springer, New York, 2011).Komodakis, N. & Pesquet, J.-C. Playing with duality: an overview of recent primal dual approaches for solving large-scale optimization problems. IEEE Signal Proc. Mag. 32, 31–54 (2015).Chandrasekharan, H. K. et al. Multiplexed single-mode wavelength-to-time mapping of multimode light. Nat. Commun. 8, 14080 (2017).Wadsworth, W. J. et al. Very high numerical aperture fibers. Photon. Technol. Lett. 16, 843–845 (2004).Pesquet, J.-C. & Repetti, A. A class of randomized primal-dual algorithms for distributed optimization. J. Nonlinear Convex Anal. 16, 2353–2490 (2015).Chambolle, A., Ehrhardt, M. J., Richtárik, P. & Schönlieb, C.-B. Stochastic primal-dual hybrid gradient algorithm with arbitrary sampling and imaging applications. SIAM J. Optim. 28, 2783–2808 (2018).Bolte, J., Sabach, S. & Teboulle, M. Proximal alternating linearized minimization for nonconvex and nonsmooth problems. Math. Program. 146, 459–494 (2014).Chouzenoux, E., Pesquet, J.-C. & Repetti, A. A block coordinate variable metric forward-backward algorithm. J. Glob. Optim. 66, 457–485 (2016).Flusberg, B. A. et al. Fiber-optic fluorescence imaging. Nat. Methods 2, 941–950 (2005).Tsvirkun, V. et al. Bending-induced inter-core group delays in multicore fibers. Opt. Express 25, 31863–31875 (2017).Candès, E. J., Wakin, M. B. & Boyd, S. Enhancing sparsity by reweighted l1 minimization. J. Fourier Anal. Appl. 14, 877–905 (2008).Condat, L. A primal–dual splitting method for convex optimization involving lipschitzian, proximable and linear composite terms. J. Optim. Theory Appl. 158, 460–479 (2013).Vu, B. C. A splitting algorithm for dual monotone inclusions involving cocoercive operators. Adv. Comp. Math. 38, 667–681 (2013)

ПЕРВЫЕ РЕЗУЛЬТАТЫ РАДИКАЛЬНЫХ И УСЛОВНО РАДИКАЛЬНЫХ РЕЗЕКЦИЙ ПРИ ОПУХОЛИ КЛАЦКИНА

Relevance: Hilar cholangiocarcinoma is the most common malignant tumor of the bile ducts.Aim: analysis of the first experience of radical and conditionally radical operations performed in MCSC during one year.Materials and methods: Extended hepatectomies combined with resection of bile ducts and first segment performed in 18 patients with Klatskin tumor. Right hemihepatectomy performed in 8 patients, resection with caudal lobectomy – in 8 patients. The preoperative percutaneous right-sided selective portal embolisation using Celonova microspheres was performed in 5 patients. One patient with type II tumor according to Bismuth-Corlette classification underwent hemihepatectomy with a left caudal lobectomy and resection of the extrahepatic bile ducts using laparoscopic approach and DaVinci robotic system.Results: The average volume of intraoperative blood loss was 705±616 ml (range 200 to 2000 ml). Postoperative III and IV grade complications according to Clavien-Dindo classification occurred in 13 patients (72%). Two patients (11%) died postoperatively. The cause of death in both observations was severe sepsis. Patients with R1 and R2-resections undergo adjuvant chemotherapy with no objective signs of progression. Patients with R0-resection are under observation with no signs of progression.Conclusion: Late diagnosis, a high risk of postoperative complications requires a multidisciplinary approach at each stage of the treatment of Klatskin tumor.Актуальность. Воротная холангиокарцинома является наиболее частой из злокачественных опухолей желчных протоков.Цель. Анализ первого опыта радикальных и условно радикальных операций, выполненных в МКНЦ в течение года.Материал и методы. Обширные резекции печени в сочетании с резекцией протоков и первого сегмента выполнены 18 пациентам с опухолью Клацкина. Правосторонняя гемигепатэктомия выполнена 8 пациентам, резекция с каудальной лобэктомией  — 8 пациентам. В предоперационном периоде правосторонняя чрескожная селективная портальная эмболизация микросферами Celonova выполнена 5 пациентам. Одному пациенту со II типом опухоли по Bismuth-Corlette левосторонняя гемигепатэктомия с каудальной лобэктомией и резекцией внепеченочных желчных протоков выполнена лапароскопическим доступом с использованием роботизированного комплекса DaVinci.Результаты. Средний объем интраоперационной кровопотери составил 705±616 мл (200–2000 мл). Послеоперационные осложнения III и V типов согласно классификации послеоперационных осложнений Clavien-Dindo имели место у 13 пациентов (72%). На госпитальном этапе умерло 2 пациента (11%). Причиной летального исхода в обоих наблюдениях явился тяжелый сепсис. Пациентам, оперированным в объеме R1 и R2, проводится химиотерапевтическое лечение. Убедительных данных за прогрессирование заболевания нет. Пациенты, оперированные в объеме R0, находятся под наблюдением без признаков прогрессии.Заключение. Поздняя диагностика, высокий риск осложнений хирургического лечения опухоли Клацкина требует мультидисциплинарного подхода на каждом из этапов лечения. Относительно медленное прогрессирование опухоли по сравнению с другими холангиокарциномами оправдывает агрессивную хирургическую тактику и целесообразность адъювантной химиотерапии при R1, R2 резекциях. Лучшие результаты лечения обеспечивает резекция в объеме R0

Russian consensus on exoand endocrine pancreatic insufficiency after surgical treatment

The Russian consensus on exo - and endocrine pancreatic insufficiency after surgical treatment was prepared on the initiative of the Russian "Pancreatic Club" on the Delphi method. His goal was to clarify and consolidate the opinions of specialists on the most relevant issues of diagnosis and treatment of exo - and endocrine insufficiency after surgical interventions on the pancreas. An interdisciplinary approach is provided by the participation of leading gastroenterologists and surgeons

The Russian consensus on the diagnosis and treatment of chronic pancreatitis: Enzyme replacement therapy

The Russian consensus on the diagnosis and treatment of chronic pancreatitis has been prepared on the initiative of the Russian Pancreatology Club to clarify and consolidate the opinions of Russian specialists (gastroenterologists, surgeons, and pediatricians) on the most significant problems of diagnosis and treatment of chronic pancreatitis. This article continues a series of publications explaining the most significant interdisciplinary consensus statements and deals with enzyme replacement therapy

Прогнозирование панкреатической фистулы после панкреатодуоденальной резекции с помощью компьютерной томографии

Aim. To reveal and evaluate opportunities of preoperative computer tomography (CT) for pancreatic fistula (PF) prediction after pancreatoduodenectomy.Materials and methods. In 2005 International Study Group on Pancreatic Fistula (ISGPF) developed grading criteria for PF, including asymptomatic biochemical (Grade A), that could be treated conservatively, and clinically relevant (Grade B, Grade C), with consecutive active surgical treatment. For now ISGPF definition of PF is widely accepted. We review the literature since 2005 for original articles in English describing quantitive assessment of the pancreatic parenchyma using CT with histological validation. Low sample trials (<10 cases) were excluded.Results. Three original publications met the inclusion criteria. Fatty and fibrosis infiltration of the pancreatic parenchyma assessed by preoperative CT revealed statistically significant correlation with PF rate.Conclusion. Preoperative CT offers accurate prediction opportunities for postoperative pancreatic fistula and may help caregivers to set up protocols for a strict and early detection of warning clinical signs, to tailor the clinical management of different risk classes, or to select high-risk patients who might be excluded from surgical resection. This would also improve patient selection for relevant research protocols and facilitate a more definitive assessment of collected data related to surgical outcomes, across different institutions and surgeons, and even among different surgeries, in either single-institution or multi-center trials that involve pancreatic surgery.Цель исследования: выявить и оценить возможности прогнозирования панкреатической фистулы после панкреатодуоденальной резекции на основании данных предоперационной компьютерной томографии (КТ).Материал и методы. В 2005 г. Международная рабочая группа по изучению панкреатических фистул (International Study Group on Pancreatic Fistula, ISGPF) разработала критерии градации панкреатических фистул на бессимптомные биохимические (Grade A) и клинически значимые (Grade B и С), требующие терапевтической (Grade A) или хирургической коррекции (Grade B и С). Данная классификация стала общепринятой и широко используется. Проведен анализ литературы, при котором учитывались только оригинальные англоязычные публикации после 2005 г, которые описывали возможности предоперационной количественной оценки плотности поджелудочной железы (ПЖ) с помощью КТ, а данные КТ сопоставлялись с результатами гистологического исследования ткани ПЖ. Работы с малыми выборками (<10 пациентов) были исключены из анализа.Результаты. Критериям включения соответствовали 3 статьи, описывающие возможности КТ для оценки степени фиброза и жировой инфильтрации паренхимы ПЖ, в качестве факторов риска панкреатической фистулы. Выявлена статистически достоверная зависимость данных показателей и риска панкреатической фистулы.Заключение. Современные возможности Кт позволяют объективно судить о риске развития панкреатической фистулы и предоставляют хирургам возможность подобрать наиболее подходящую периоперационную тактику ведения пациента. Прогнозирование риска панкреатической фистулы и формирование гомогенных групп для клинических исследований позволят получать более достоверные результаты при анализе данных даже из разных источников, что, несомненно, повысит качество проводимых исследований

Российский консенсус по профилактике, диагностике и лечению рака желудка

The Russian consensus on prevention, diagnostic and treatment of gastric cancer was prepared on the initiative of the Moscow clinical scientific center named after A. S. Loginov according to the Delphi method. Its aim was to clarify and consolidate the opinions of specialists on the most relevant issues of prevention, diagnosis and treatment of gastric cancer. An interdisciplinary approach was provided by the participation of leading gastroenterologists, oncologists and surgeons.Российский консенсус по профилактике, диагностике и лечению рака желудка подготовлен по инициативе Московского клинического научного центра им А. С. Логинова ДЗМ по Дельфийской системе. Его целью явилась консолидация мнений отечественных специалистов по наиболее актуальным вопросам профилактики, скрининга, диагностики и лечения рака желудка. Междисциплинарный подход обеспечен участием ведущих гастроэнтерологов, онкологов и хирургов.Цель статьи: представить положения Российского консенсуса по профилактике, диагностике и лечению рака желудка