Особенности периоперационного ведения пожилых больных при эндоскопическом транссфеноидальном удалении опухолей хиазмально-селлярной области

Nowadays, in the age of rapid introduction of digital and fiber-optic technologies in neurosurgery, a technique for removal of tumors in the chiasmatic-sellar area via an endoscopic transsphenoidal endonasal approach is actively developed; this technique is considered less invasive and is well tolerated by patients, thus permitting to operate patients with somatic complications, as well as the elderly. Taking into account these facts, as well as world statistic data indicating a continuous trend of population aging in developed countries, including Russia, optimization of the perioperative care of elderly patients with a tumor of the chiasmatic-sellar area becomes the problem of highest priority. In order to solve it, this review discusses the basic peculiarities of the perioperative management of elderly patients (characteristics of their somatic status and possible variants of the pre-operational state) with a pathology in the chiasmatic-sellar region; it also presents the modern and most acceptable alternative solutions of this difficult problem (introduction of modern methods of anesthesia, management of the postoperative cognitive dysfunction, postoperative pain syndrome, and postoperative nausea and vomiting). В наши дни, в век бурного внедрения в нейрохирургию цифровых и оптико-волоконных технологий, активно развивается метод удаления опухолей хиазмально-селлярной области эндоскопическим эндоназальным транссфеноидальным доступом, который считается малотравматичным и хорошо переносится больными, в результате чего расширияется возможность оперировать соматически отягощенных больных, а также людей старшей возрастной группы. Учитывая эти факты, а также данные мировой статистики, указывающие на неуклонную тенденцию старения населения в развитых странах, в том числе и в России, оптимизация периоперационного ведения пожилых больных, имеющих опухоль хиазмально-селлярной области, становится наиболее приоритетной задачей. Для ее решения в данной статье рассмотрены основные нюансы периоперационного ведения пожилых больных, имеющих патологию хиазмально-селлярной области: особенности их соматического статуса и возможные варианты их предоперационного состояния. Также представлены современные и наиболее приемлемые альтернативные варианты решения этой непростой проблемы: внедрение современных методик анестезии, борьба с послеоперационной когнитивной дисфункцией, послеоперационным болевым синдромом и послеоперационной тошнотой и рвотой.

Observation of robust polarization squeezing via the Kerr nonlinearity in an optical fibre

Squeezed light is one of the resources of photonic quantum technology. Among the various nonlinear interactions capable of generating squeezing, the optical Kerr effect is particularly easy-to-use. A popular venue is to generate polarization squeezing, which is a special self-referencing variant of two-mode squeezing. To date, polarization squeezing generation setups have been very sensitive to fluctuations of external factors and have required careful tuning. In this work, we report on a development of a new all-fibre setup for polarization squeezing generation. The setup consists of passive elements only and is simple, robust, and stable. We obtained more than 5 dB of directly measured squeezing over long periods of time without any need for adjustments. Thus, the new scheme provides a robust and easy to set up way of obtaining squeezed light applicable to different applications. We investigate the impact of pulse duration and pulse power on the degree of squeezing

Comparative assessment of energy metabolism, body composition and metabolic features in children with hypothalamic and simple obesity

Background: Hypothalamic obesity often develops after surgical treatment of craniopharyngioma and is characterized by rapid weight gain, high frequency of metabolic disorders, body composition specificity and resistance to standard lifestyle modification approaches and medication therapy of obesity. Recent studies show that one of the mechanisms, explaining weight gain in these children is decrease in resting energy expenditure (REE).Aims: To compare REE, body composition parameters, and the frequency of metabolic disorders in children with hypothalamic and simple obesity.Materials and methods: The study included 60 obese children aged 7 to 17 years, divided into two groups. The study group included 20 children with hypothalamic obesity, developed after craniopharyngioma treatment. The control group consisted of 40 children with simple obesity. Body composition, REE, and metabolic disorders were associated in all children.Results: Children with hypothalamic obesity showed a significant decrease of resting energy expenditure. The average decrease in REE was 13.1%, but in single patients it reached 33.4%. The percentage of fat mass in hypothalamic and simple obesity does not differ significantly (39.7% [36.2; 42.6] vs 38.8 % [35.9; 43.2]; p=0.69). Screening for metabolic disorders revealed a high prevalence of metabolic disorders in hypothalamic obesity: impaired glucose tolerance - in 10%; dyslipidemia - 55%, insulin resistance-50%, non-alcoholic fatty liver disease - 60 %.Conclusions: Children with hypothalamic obesity showed a significant decrease of resting energy expenditure. When planning a diet in this group of patients it is preferable to use indirect calorimetry. Hypothalamic obesity even at an early age is associated with a high frequency of metabolic disturbance. Hypothalamic obesity in children is not associated with more pronounced hyperinsulinemia and insulin resistance compared to the simple obesity

Towards local electromechanical probing of cellular and biomolecular systems in a liquid environment

Electromechanical coupling is ubiquitous in biological systems with examples ranging from simple piezoelectricity in calcified and connective tissues to voltage-gated ion channels, energy storage in mitochondria, and electromechanical activity in cardiac myocytes and outer hair cell stereocilia. Piezoresponse force microscopy (PFM) has originally emerged as a technique to study electromechanical phenomena in ferroelectric materials, and in recent years, has been employed to study a broad range of non-ferroelectric polar materials, including piezoelectric biomaterials. At the same time, the technique has been extended from ambient to liquid imaging on model ferroelectric systems. Here, we present results on local electromechanical probing of several model cellular and biomolecular systems, including insulin and lysozyme amyloid fibrils, breast adenocarcinoma cells, and bacteriorhodopsin in a liquid environment. The specific features of SPM operation in liquid are delineated and bottlenecks on the route towards nanometer-resolution electromechanical imaging of biological systems are identified.Comment: 37 pages (including refs), 8 figure

Design, Performance, and Calibration of CMS Hadron Endcap Calorimeters

Detailed measurements have been made with the CMS hadron calorimeter endcaps (HE) in response to beams of muons, electrons, and pions. Readout of HE with custom electronics and hybrid photodiodes (HPDs) shows no change of performance compared to readout with commercial electronics and photomultipliers. When combined with lead-tungstenate crystals, an energy resolution of 8\% is achieved with 300 GeV/c pions. A laser calibration system is used to set the timing and monitor operation of the complete electronics chain. Data taken with radioactive sources in comparison with test beam pions provides an absolute initial calibration of HE to approximately 4\% to 5\%

Synchronization and Timing in CMS HCAL

The synchronization and timing of the hadron calorimeter (HCAL) for the Compact Muon Solenoid has been extensively studied with test beams at CERN during the period 2003-4, including runs with 40 MHz structured beam. The relative phases of the signals from different calorimeter segments are timed to 1 ns accuracy using a laser and equalized using programmable delay settings in the front-end electronics. The beam was used to verify the timing and to map out the entire range of pulse shapes over the 25 ns interval between beam crossings. These data were used to make detailed measurements of energy-dependent time slewing effects and to tune the electronics for optimal performance

Energy Response and Longitudinal Shower Profiles Measured in CMS HCAL and Comparison With Geant4

The response of the CMS combined electromagnetic and hadron calorimeter to beams of pions with momenta in the range 5-300 GeV/c has been measured in the H2 test beam at CERN. The raw response with the electromagnetic compartment calibrated to electrons and the hadron compartment calibrated to 300 GeV pions may be represented by sigma = (1.2) sqrt{E} oplus (0.095) E. The fraction of energy visible in the calorimeter ranges from 0.72 at 5 GeV to 0.95 at 300 GeV, indicating a substantial nonlinearity. The intrinsic electron to hadron ratios are fit as a function of energy and found to be in the range 1.3-2.7 for the electromagnetic compartment and 1.4-1.8 for the hadronic compartment. The fits are used to correct the non-linearity of the e pi response to 5% over the entire measured range resulting in a substantially improved resolution at low energy. Longitudinal shower profile have been measured in detail and compared to Geant4 models, LHEP-3.7 and QGSP-2.8. At energies below 30 GeV, the data, LHEP and QGSP are in agreement. Above 30 GeV, LHEP gives a more accurate simulation of the longitudinal shower profile

Design, Performance and Calibration of the CMS Forward Calorimeter Wedges

We report on the test beam results and calibration methods using charged particles of the CMS Forward Calorimeter (HF). The HF calorimeter covers a large pseudorapidity region (3\l |\eta| \le 5), and is essential for large number of physics channels with missing transverse energy. It is also expected to play a prominent role in the measurement of forward tagging jets in weak boson fusion channels. The HF calorimeter is based on steel absorber with embedded fused-silica-core optical fibers where Cherenkov radiation forms the basis of signal generation. Thus, the detector is essentially sensitive only to the electromagnetic shower core and is highly non-compensating (e/h \approx 5). This feature is also manifest in narrow and relatively short showers compared to similar calorimeters based on ionization. The choice of fused-silica optical fibers as active material is dictated by its exceptional radiation hardness. The electromagnetic energy resolution is dominated by photoelectron statistics and can be expressed in the customary form as a/\sqrt{E} + b. The stochastic term a is 198% and the constant term b is 9%. The hadronic energy resolution is largely determined by the fluctuations in the neutral pion production in showers, and when it is expressed as in the electromagnetic case, a = 280% and b = 11%

Design, Performance, and Calibration of the CMS Hadron-Outer Calorimeter

The CMS hadron calorimeter is a sampling calorimeter with brass absorber and plastic scintillator tiles with wavelength shifting fibres for carrying the light to the readout device. The barrel hadron calorimeter is complemented with an outer calorimeter to ensure high energy shower containment in the calorimeter. Fabrication, testing and calibration of the outer hadron calorimeter are carried out keeping in mind its importance in the energy measurement of jets in view of linearity and resolution. It will provide a net improvement in missing \et measurements at LHC energies. The outer hadron calorimeter will also be used for the muon trigger in coincidence with other muon chambers in CMS