bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Interaction between Low-Viscosity High-Permeability Pregrouting Sealing Material and Coal and Its Application
Authors: Chen Yujia , Li Ao , Yang Dingding , Liu Tianyu , Li Xiaowei , Tang Jun , Jiang Chenglin
Published: February 2020

In order to ensure the intactness of pressure-measuring boreholes and the accuracy of gas pressure determination, pregrouting treatment with polymer materials is frequently applied to bedding drilling in coal mines. However, the existing polyurethane materials are of high viscosity, low permeability, and poor safety, bringing great difficulties to their field promotion and application. In view of this problem, after optimization and experiments, polylactide polyol/polyether polyol 4110/isocyanate was determined as the target system. Bio-based benzoxazine (Boz-F), red phosphorus, and melamine with a mass ratio of 2 : 1 : 2 were used as the flame retardant, which then underwent mechanical modification by hollow glass bubbles. Finally, the pregrouting material with low viscosity and high permeability was compounded, and its interaction with coal was experimentally studied. The results show that compared with traditional polyurethane, the new material increases the effective consolidation distance in the coal seam by 40% on average. Its permeation radius is also larger than the calculated radius of the plastic softening zone of a borehole. In addition, the strengths of coal-new material consolidated products with different ratios fully surpass those of coal-polyurethane material consolidated products. The enhancement of compressive strength and bending strength is up to 153% and 161%, respectively. The field application indicates that after pregrouting treatment of boreholes in the coal seam with the new material, the borehole formation rate reaches 100%. Therefore, the new material is safe and practical for gas pressure measurement through bedding drilling on site.
Clinical Investigation into Posterior Capsule Rupture in Phacoemulsification Operations Performed by Surgery Trainees
Authors: Bai Haiqing , Yao Lin , Wang Haitao
Published: February 2020

This retrospective cohort study investigated the occurrence rate, correlative factors, and prognosis of posterior capsule rupture (PCR) in phacoemulsification operations conducted by surgery trainees. This study assessed the first 200 phacoemulsification surgeries performed by six surgery trainees between August 2016 and December 2018. Cases were divided into two groups depending on whether they fell within the first 100 surgeries performed by a trainee (first 100 cases group) or the last 100 surgeries (last 100 cases group). The following clinical data were analyzed: the occurrence rate of PCR, whether this complication arose in the phaco or irrigation/aspiration (IA) phase, the occurrence of vitreous loss, retinal detachment, and dropped nucleus, the site of intraocular lens (IOL) implantation, and postoperative visual acuity. Thirty-nine of the 1200 cases (3.25%) experienced PCR. The occurrence rates of PCR and vitreous loss were higher in the first 100 cases group than in the last 100 cases group (P=0.015 and P=0.017). PCR occurred more frequently in the phaco phase in the first 100 cases group and in the IA phase in the last 100 cases group (P=0.012). There was no difference between the two groups in terms of site of IOL implantation, the occurrence of retinal detachment or dropped nucleus, and postoperative visual acuity. With a supervising surgeon and the selection of suitable cases, the occurrence rate of PCR in phacoemulsification operations performed by surgery trainees could be controlled to the desired level. The phase in which PCR most frequently occurred and the likelihood of vitreous loss differed depending on the level of surgical experience of the trainees. It is a lengthy process for surgery trainees to reach the stage at which they can manage PCR and complex cataract surgery independently.
Intracardiac Fibrinolysis and Endothelium Activation Related to Atrial Fibrillation Ablation with Different Techniques
Authors: Hajas Orsolya , Bagoly Zsuzsa , Tóth Noémi K , Urbancsek Réka , Kiss Alexandra , Kovács Kitti B , Sarkady Ferenc , Nagy Attila , Oláh Anna V. , Nagy László , Clemens Marcell , Csiba László , Csanádi Zoltán
Published: February 2020

Objective. The effect of pulmonary vein isolation (PVI) on fibrinolytic and endothelial activation with currently applied periprocedural anticoagulation has not been explored. We measured markers of fibrinolysis and endothelium activation before and after PVI with the second-generation cryoballoon (Cryo), pulmonary vein ablation catheter (PVAC-Gold), and irrigated radiofrequency (IRF). Methods. Markers of fibrinolysis and endothelium activation in left atrial (LA) blood samples were measured in 31 patients before and after PVI (Cryo:10, PVAC-Gold: 7, IRF: 14). Periprocedural anticoagulation included uninterrupted vitamin K antagonist and iv heparin (ACT≥300 sec) during LA dwelling. Results. Levels of D-dimer (median; interquartile range, mgFEU/L) increased with all techniques (PVAC: 0.34; 0.24–0.50 versus 0.70; 0.61–1.31; p=0.0313, Cryo: 0.33; 0.28–0.49 versus 0.79; 0.65–0.93; p=0.0078; IRF 0.33; 0.21–0.44 versus 0.83; 0.56–1.21; p=0.0001). PAP complex level (ng/ml) increased after Cryo (247.3, 199.9–331.6 versus 270.9, 227.9–346.7; p=0.0020) and IRF (265.3; 202.0–800.1 versus 325.6, 250.2–701.9; p=0.0166), but not after PVAC (p=0.2969). PAI-1 activity (%) decreased with the PVAC (1.931; 0.508–3.859 versus 0.735, 0.240–2.707; p=0.0313) and Cryo (0.361; 0.080–1.575 versus 0.378; 0.111–0.915; p=0.0313). A similar trend was observed with IRF (p=0.0676). Both VWF antigen levels and FVIII activity increased after PVI with all the 3 techniques. The levels of soluble VCAM-1 (ng/ml) did not change after PVAC procedures, but increased after Cryo (542, 6; 428.5–753.1 versus 619.2; 499.8–799.0; p=0.0005) and IRF (679.3; 505.0–744.7 versus 770.9; 631.9–894.0; p<0.0001). Conclusion. PVI with contemporary ablation techniques and periprocedural antithrombotic treatment induces coagulation and endothelium activation of similar magnitude with different ablation methods.
Adjacent Channel Interference Modeling of Single Vibration Point on Multichannel Dynamic Pressure Sensors
Authors: Geng Xingguang , Liu Su , Zhang Yitao , Zhang Shaolong , Hou Jiena , Zhang Jun , Asif Muhammad , Zhang Hai-Ying
Published: February 2020

Pulse waves of a radial artery under different pressures applied through a cuff play an important role in disease diagnosis, especially in traditional chinese medicine (TCM). Pulse waves could be collected by a pressure sensor array affixed to an inflatable cuff. During a process of collecting pulse waves, one sensor of a sensor array moves up and down when the sensor is shocked by a pulse wave. Movement of the sensor leads to the passive displacement of other nearby sensors because of a connecting structure between them. Then, vibration signals will be generated by the nearby sensors although these sensors do not receive radial artery pulse waves. These vibration signals considered an interference are usually superimposed on real signals obtained from these nearby sensors and degrade signal quality. The problem mentioned above does not only generally exist in a pressure sensor array attached to a wristband but also is easy to ignore. This paper proposes a novel interference suppression algorithm based on Welch’s method for estimating and weakening adjacent sensor channel interference to overcome the problem. At first, a sensor array attached to an inflatable cuff and a vibration generator is proposed to establish an experimental platform for simplifying the pulse wave collection process. Then, the interference suppression algorithm is proposed according to mechanical analysis and Welch’s method based on the proposed sensor array and vibration generator. Next anti-interference abilities of the algorithm based on a simplified process are evaluated by different vibration frequencies and applied pressures. The anti-interference abilities of the algorithm based on pulse waves of the radial artery are evaluated indirectly. The results show that the novel interference suppression algorithm could weaken adjacent sensor channel interference and upgrade the signal quality.
Reaction Kinetics of Chlorine Corrosion to Heating Surfaces during Coal and Biomass Cofiring
Authors: Wang Yongzheng , Sun Yu , Yue Maozhen , Li Yungang
Published: February 2020

The high content of chlorine in biomass will cause serious ash deposition and corrosion problems on the heating surface in boiler, reduce heat transfer efficiency, and endanger the boiler operation safety. On the basis of discussing the mechanism of chlorine corrosion to heating surface in the boiler, the temperature, atmosphere, and fouling in the boiler are simulated by high-temperature reaction device. Reaction kinetics of chlorine corrosion to heating surfaces during coal and biomass cofiring was studied by the weight gain method, which provides a theoretical basis for solving the problem of corrosion and improving the safety of boiler operation. The results show that the weight gain caused by corrosion increases with time, and its curve is in accordance with the parabola. In the early stage, the corrosion rate is very fast, and the corrosion gradually slows down after the protective layer is formed. The mixing ratio of straw biomass increases, and the corrosion rate increases proportionally. With the increase in temperature, the rate of corrosion reaction increases continuously. When the temperature exceeds 600°C, the corrosion reaction rate increases greatly. The concentration of HCl in the gas phase increases and the rate of corrosion reaction increases rapidly. Under the constant temperature, the reaction kinetics characteristics of chlorine corrosion were analyzed by model function matching. The best kinetic model function for calculating the kinetic parameters was determined, and the kinetic equation of corrosion reaction was established to quantitatively characterize the corrosion reaction.
The Cardinal Spline Methods for the Numerical Solution of Nonlinear Integral Equations
Authors: Liu Xiaoyan , Xie Jin , Liu Zhi , Huang Jiahuan
Published: February 2020

In this study, an effective technique is presented for solving nonlinear Volterra integral equations. The method is based on application of cardinal spline functions on small compact supports. The integral equation is reduced to a system of algebra equations. Since the matrix for the system is triangular, it is relatively straightforward to solve for the unknowns and an approximation of the original solution with high accuracy is accomplished. Several cardinal splines are employed in the paper to enhance the accuracy. The sufficient condition for the existence of the inverse matrix is examined, and the convergence rate is analyzed. We compare our method with other methods proposed in recent papers and demonstrated the advantage of our method with several examples.
Fault Detection Filter Design of Polytopic Uncertain Continuous-Time Singular Markovian Jump Systems with Time-Varying Delays
Authors: Shi Yunling , Peng Xiuyan
Published: February 2020

This paper investigates the problem of full-order and reduced-order fault detection filter (FDF) design under unified linear matrix inequality (LMI) conditions for a class of continuous-time singular Markovian jump systems (CTSMJSs) with time-varying delays and polytopic uncertain transition rates. By constructing a new Lyapunov function, sufficient conditions are firstly provided for the singular model error augmented system such that the system is stochastically admissible with an H∞ performance level γ. And then, by applying a novel convex polyhedron technique to decoupled linear matrix inequalities, the full-order and reduced-order fault detection filter parameters can be obtained within a convex optimization frame. The reduced-order fault detection filter (FDF) can not only meet the fault detection accuracy requirements of complex systems but also improve the fault detection efficiency. Finally, a DC motor and an illustrative simulation example are given to verify the feasibility and effectiveness of the proposed algorithms.
An Approach Based on Customized Robust Cloaked Region for Geographic Location Information Privacy Protection
Authors: Shen Zhidong , Lu Siyuan , Huang Huijuan , Yuan Meng , Tang Guoming , Chen Weiying , Zhang Taige , Zhong Ting
Published: February 2020

Location-based services (LBS) have gained huge popularity because of the easy availability of modern mobile devices and the fast development of geographical information science (GIS). However, the lack of protection for private user positions might give rise to privacy concerns. This kind of problem is especially serious in mobile application environment because many mobile applications tend to use LBS. In this paper, we propose a new privacy preserving approach using customized robust cloaked region (RCR), depending on a peer-to-peer structure and the premise that users do not trust each other when sharing their geographical locations. Two algorithms are used to generate the RCR with high user density. The area of the RCR is controlled by the user’s demanded degree of protection. To enhance the resistance to regional background knowledge attack, we incorporate a location semantic value into each unit of the user map. According to extensive simulations, our method can effectively obfuscate a user’s geographical location into a highly indistinguishable region because of the disturbance of nearby users and different equally possible locations.
Simulating Study on Mechanical Properties of Rock Wool Board for Thermal Insulation on External Walls
Authors: Li Xiaoguang , Liu Jinjin , Fan Xin , Qin Jinyi , Zhang Rui , Cao Ren , Wang Panqi , Huo Xiaoliang
Published: February 2020

Rock wool board (RWB) is widely used in construction of exterior insulation worldwide. Fiber diameter, solid volume fraction (SVF), and contact degree among the fibers significantly influence the RWB physical properties. Herein, the effects of these factors on the mechanical properties of RWB were investigated using the GeoDict software. First, the fiberization process resulted in a finer fiber diameter, and the SVF of RWB increased with decreasing pore sizes. In addition, both the fiber diameter and SVF significantly influenced the RWB shear strength. Furthermore, in compliance with the Chinese standards of compression, tensile, and shear strength, the SVF of RWB with a 10.5 μm fiber diameter did not exceed 4.72%, 4.04%, and 5.4%, respectively. The novel method proposed herein can be used for optimizing the RWB manufacturing process.
Transhepatic Insertion of Percutaneous Endoscopic Gastrostomy Tube
Authors: Imam Zaid , Simons-Linares C. Roberto
Published: February 2020

Inadvertent injury to interposing organs during percutaneous endoscopic gastrostomy (PEG) tube placement is a feared complication of this common and generally safe procedure. Transhepatic PEG insertion is likely an underrepresented complication which may be identified incidentally on imaging or present with life-threatening conditions such as sepsis or massive bleeding. Use of ultrasound in patients with known hepatomegaly may possibly help avoid this complication. We hereby report a case of transhepatic PEG insertion, one of 16 only other cases published in the literature, and review the characteristics of the previous reported cases.
A High-Precision Fatigue Detecting Method for Air Traffic Controllers Based on Revised Fractal Dimension Feature
Authors: Shen Zhiyuan , Pan Guozhuang , Yan Yonggang
Published: February 2020

As air traffic volume increases, the air traffic controller (ATC) fatigue has become a major cause for air traffic accidents. However, the conventional fatigue-detecting methods based on speech are neither effective nor accurate because the speech signals are nonlinear and complicated. In this paper, an ATC fatigue-detecting method based on fractal dimension (FD) is proposed. Firstly, a special speech database of ATC radiotelephony communications is constructed. These radiotelephony communications are obtained from Air Traffic Management Shandong Bureau of China. Then, speech signals implement a wavelet decomposition and FD calculation. The calculation result shows the significant difference among the FD of the speech signal before and after fatigue. Furthermore, a novel fatigue feature of the ATC based on the FD of speech is built. A series of experiments are conducted to detect the ATC fatigue with the fatigue feature comparison process and a support vector machine (SVM). The results show that the accuracy in detecting ATC fatigue based on FD was 92.82%, which are higher than the state-of-the art methods. The research provides a theoretical guidance for Air Traffic Management Authority on detecting ATC’s fatigue, while it may provide reference for the fatigue assessment in other professional fields of civil aviation.
Sealing Performance of New Solidified Materials: Mechanical Properties and Stress Sensitivity Characterization of Pores
Authors: Zhang Chao , Jin Gaohan , Liu Chao , Li Shugang , Xue Junhua , Cheng Renhui , Liu Hua
Published: February 2020

Borehole-sealing solidified material plays a significant role in improving sealing quality and enhancing gas drainage performance. In this study, the MTS815 electro-hydraulic triaxial servo test system and MR-60 NMR test system were adopted to conduct triaxial compression control experiment on the coal sample material, concrete material, and new solidified sealing material, respectively. This paper aims to analyze the difference of support effects, porosity, and stress sensitivity between those materials. Experimental results show that under the same stress condition, the stiffness of traditional concrete solidified material is the largest, while the new solidified material is the second, and the coal sample material is the smallest. Compared with the traditional concrete solidified material, the new solidified sealing material has better strain-bearing capacity and volumetric expansion capacity under each confining pressure in the experiment. The axial strain and volume increment of new solidified material is higher than those of the traditional concrete solidified material at the peak stress. Meanwhile, the confining pressure has a certain hysteresis effect on the postpeak stress attenuation. Fracture has the strongest stress sensitivity in three pore types, and its T2 map relaxation area has a larger compression than adsorption pore and seepage pore under the same pressure. The relative content of seepage pore and fracture in the new solidified material is less than that of coal and concrete samples, and the stress sensitivity of the new solidified materials is weaker than that of coal and concrete materials, thence, new solidified material will have better performance in borehole sealing. Outcomes of this study could provide guidance on the selection of the most effective sealing materials for sealing-quality improvement.
An Optimized RBF Neural Network Based on Beetle Antennae Search Algorithm for Modeling the Static Friction in a Robotic Manipulator Joint
Authors: Wang Yuxiang , Chen Zhangwei , Zu Hongfei , Zhang Xiang
Published: February 2020

Friction is a nonlinear effect that occurs in all mechanical systems which may cause limit cycles, tracking errors, and other undesirable effects. Traditional static friction models cannot characterize all the friction situations. In recent years, neural network (NN) technique has been widely used to approximate the nonlinear function. In this paper, a new method which combines radical basis function neural network (BRFNN) with beetle antennae search (BAS) algorithm for modeling friction in a robotic joint is proposed. Velocity, load, and temperature are considered as the three factors that influence the static friction. It is shown that the proposed BAS-RBFNN possesses better performance in terms of faster convergence rate and higher accuracy.
Optimal Fault Tolerant Control of Large-Scale Wind Turbines in the Case of the Pitch Actuator Partial Faults
Authors: El Maati Younes Ait , El Bahir Lhoussain
Published: February 2020

In this paper, an adaptive fault tolerant control strategy is proposed to deal with the three pitch actuator faults in the large-scale wind turbines. Firstly, a simultaneous state and fault estimation was performed through a suitable LMI (linear matrix inequality) based optimal strategy. Hereafter, the new control law is designed using the previously estimated fault information. The actuator efficiency estimator uses as design parameters, respectively, the performance index γ against the wind and the learning rate Ξ. of the fault estimation algorithm. The study shows that the choice of the previous two parameters impacts the response time of the fault estimation and the correlation of the tracking error with the wind. The aim is to choose a small fault estimation response time while keeping a weak correlation between the tracking error and the wind turbulence noise. Finally, a tuning strategy is elaborated to choose the suitable γ and Ξ to match the reconfiguration objective.
An Investigation on Mechanical Behavior of Tooth-Plate-Glass-Fiber Hybrid Sandwich Beams
Authors: Xie Honglei , Wan Li , Wang Bo , Pei Haiping , Liu Weiqing , Yue Kong , Wang Lu
Published: February 2020

Tooth-plate-glass-fiber hybrid sandwich (TFS) is a type of sandwich composites fabricated by vacuum-assisted resin infusion process, in which glass fiber facesheets reinforced by metal plate are connected to foam core through tooth nails. Bending properties and interlaminar properties of TFS beams with various foam densities were investigated by flexural tests and DCB (double cantilever beam) tests. The test results showed that by increasing the foam core density from 35 kg/m3 to 150 kg/m3, the peak strength of TFS beams significantly increased by 168% to 258% compared with similar sandwich beams with fibrous composite facesheets. With the change of foam density and span length, the main failure modes are core shear and facesheet indentation beneath the loading roller. The interlaminar strain energy release rates of TFS specimens also increased by increasing the density of the foam. In addition, an analytical model was used to predict the ultimate bending strength of TFS beams, which were in good accordance with the experimental results.
Pre-Anesthesia Extracorporeal Membrane Oxygenation in Two Lung Transplant Recipients with Severe Pulmonary Hypertension
Authors: Minqiang Liu , Hong Gao , Jingyu Chen , Yanjuan Wang , Bo Xu , Guilong Wang , Qiang Wu , Chunxiao Hu
Published: February 2020

Extracorporeal membrane oxygenation (ECMO) is a widely used cardiopulmonary support method that is usually implemented after anesthesia during the period of lung transplantation (LTx). In severe pulmonary arterial hypertension (PAH) patients, however, anesthesia induction is a high-risk phase and can result in severe cardiorespiratory failure. Herein, we describe two severe PAH patients who received ECMO support before anesthesia and whose preoperative evaluations indicated that the risk was too high to safely survive the anesthesia induction period before LTx. The strategy was successful, and in both patients, hemodynamics was stable and no ECMO-related complications occurred.
Generalized Acquired Cutis Laxa Associated with Monoclonal Gammopathy of Dermatological Significance
Authors: Shalhout Sophia Z. , Nahas Myrna R. , Drews Reed E. , Miller David M.
Published: February 2020

Background. Cutis laxa is a rare dermatosis that is inherited or acquired and clinically features loose, wrinkled, and redundant skin with decreased elasticity. This heterogeneous connective tissue disorder may be localized or generalized, with or without internal manifestations. Generalized cutis laxa often has a cephalocaudal progression and is attributed to inflammatory cutaneous eruptions, medications, and infections. Cutis laxa is also associated with several other conditions including rheumatoid arthritis, systemic lupus erythematosus, and plasma-cell dyscrasias.Case Presentation. We report an unusual case of a 35-year-old male with progression of generalized acquired cutis laxa and vasculitis that occurred over a period of one year. No cutaneous inflammatory eruption preceded or accompanied his decreased skin elasticity, and a biopsy of the skin showed elastolysis. His cutaneous manifestation led to systemic evaluation and an eventual diagnosis of smoldering multiple myeloma accompanied by aortitis and anemia. His myeloma and vasculitis were successfully treated with cyclophosphamide, bortezomib, and dexamethasone and high-dose prednisone, respectively, with no improvement to his cutis laxa.Conclusions. The presence of monoclonal gammopathy is strongly associated with several dermatological entities such as acquired cutis laxa. We propose a new term for the dermatological manifestations caused by paraproteinemia: monoclonal gammopathy of dermatological significance, or MGODS, and stress the evaluation of an underlying gammopathy in the setting of certain dermatologic conditions, including scleromyxedema and amyloidosis. We present a case of a newly acquired cutis laxa secondary to plasma-cell dyscrasias that exemplifies MGODS, alongside a brief literature review, and underscore the clinical relevance of monoclonal gammopathies of dermatological significance.
Numerical Studies on the Heat Effect of Explosion Suppression by a Heat Pipe
Authors: Zhang Yaping , Ning Ning , Quan Xin , Zhang Shuanwei
Published: February 2020

A composite structure with a heat pipe and foamed iron-nickel composite fire suppression is proposed on the basis of the phase-change heat transfer of the heat pipe, which simultaneously attenuates the metal foam explosion energy. A numerical simulation is conducted to evaluate the feasibility of the designed construction for suppressing explosions under various thicknesses and pore diameters of the metal foam. The results demonstrate that when the foam iron-nickel metal is installed in the pipeline, the temperature reduction rate in the pipeline can reach 8.9%. The new heat pipe foam composite structure can reduce the flame temperature to 1600 K within 0.095 s. It is concluded that the heat pipe composite metal foam structure pipeline has a strong effect on suppressing combustion and explosion overpressure. Due to the combined effect of the heat pipe vacuum chamber suction energy and the foamed iron-nickel, the flame temperature decay rate increases. The maximum attenuation rate of the foamed iron-nickel for the gas explosion shock wave reaches 41.76%, and the maximum flame temperature attenuation rate reaches 64.7%. The composite heat pipe structure can quickly disperse and transfer heat, thereby effectively destroying the heat storage environment as soon as possible to prevent a secondary explosion from occurring.
Effects of CST3 Gene G73A Polymorphism on Cystatin C in a Prospective Multiethnic Cohort Study
Authors: Mohd Tahir Nor Asyikin , Mohd Saffian Shamin , Islahudin Farida Hanim , Abdul Gafor Abdul Halim , Othman Hanita , Abdul Manan Hamizah , Makmor-Bakry Mohd
Published: February 2020

Background/Aims: G73A polymorphism in the CST3 gene of cystatin C has been associated with Alzheimer’s disease, age-related macular degeneration, and cardiovascular disease. However, studies investigating the influence of this genetic variability on serum cystatin C and cystatin-based renal function estimate are limited. Therefore, the aim of this study is to investigate the possible association of single-nucleotide polymorphism (rs1064039) of the CST3 gene on the serum cystatin C level and cystatin C-based estimated glomerular filtration rate (eGFR). Methods: Study subjects include patients with various levels of renal function recruited from the nephrology clinic and wards of a tertiary hospital. The blood samples collected were analyzed for serum cystatin C and creatinine levels by particle-enhanced turbidimetric immunoassay and kinetic alkaline picrate method, respectively. DNA was extracted using a commercially available kit. ­Polymerase chain reaction results were confirmed by direct DNA Sanger sequencing. Results: The genotype percentage (G/G = 73%, G/A = 24.1%, and A/A = 2.9%) adhere to the Hardy-Weinberg equilibrium. The dominant allele found in our population was CST3 73G allele (85%). The regression lines’ slope of serum cystatin C against creatinine and cystatin C-based eGFR against creatinine-based eGFR, between G and A allele groups, showed a statistically significant difference (z-score = 3.457, p < 0.001 and z-score = 2.158, p = 0.015, respectively). Patients with A allele had a lower serum cystatin C level when the values were extrapolated at a fixed serum creatinine value, suggesting the influence of genetic factor. Conclusion: Presence of CST3 gene G73A polymorphism affects serum cystatin C levels.
СУЧАСНІ ВИМОГИ ДО ПРОВЕДЕННЯ СПІРОМЕТРІЇ
Authors: Bakalets O. V. , Behosh N. B. , Dzyha S. V. , Zaiets T. A.
Published: February 2020

Мета роботи. Висвітлити основні нововведення після останнього перегляду стандартів спірометрії, проведених Американським торакальним товариством та Європейським респіраторним това- риством у поточному році.

Матеріали і методи. Проаналізовано сучасні уявлення стосовно методології виконання спірометрії, контролю якості та аналізу її результатів.

Результати й обговорення. Представлено оновлений список відносних протипоказань, перелік видів діяльності, яких пацієнт повинен уникати перед проведенням обстеження, сучасний підхід до термінів утримання від використання бронхолітиків перед тестуванням, нова система оцінки якості результатів спірометрії, наведено нові вимоги для клінічних спірометрів тощо. В основному тексті статті використовуються англомовні абревіатури назв спірометричних параметрів. Водночас, зважаючи на можливість використання кількох «робочих» мов у сучасних спірометрах, наведено відповідність як повних, так і коротких назв українською та англійською мовами.

Висновки. Дотримання рекомендацій ATS/ERS від 2019 р. має забезпечувати виконання спірометрії та інтерпретації її результатів на належному рівні.
ОСОБЛИВОСТІ СЕСТРИНСЬКОЇ ДОПОМОГИ ВІЙСЬКОВОСЛУЖБОВЦЯМ Й МИРНОМУ НАСЕЛЕННЮ, ЯКІ ПЕРЕБУВАЛИ В ЗОНІ БОЙОВИХ ДІЙ
Authors: Tzipkalo A. I. , Kopanytsia O. M. , Mialiuk O. P.
Published: February 2020

Мета роботи. Проаналізувати основні напрямки сестринської допомоги військовослужбовцям та цивільному населенню, які перебували в зоні ведення бойових дій.

Матеріали і методи. На базі військово-медичної служби ВМС УСБУ в Закарпатській області було проаналізовано анкетні дані 30 учасників АТО, 30 осіб із переселених військових територій та 20 осіб, які є близькими родичами учасників бойових дій, проживають і доглядають за ними щодо наявності посттравматичного стресу (тривоги та депресії). Використовували шкалу госпітальної тривоги та депресії (Hospital Anxiety and Depression Scale, HADS).

Результати й обговорення. Аналіз даних, які ми отримали, свідчить про поширеність субклінічно вираженої депресії серед 56,7 % учасників АТО, клінічно вираженої депресії у 23,3 % ветеранів. При цьому субклінічно виражену депресію реєструють у 55,0 % осіб, які перебувають поруч із військовослужбовцями. Поширеність клінічно вираженої депресії серед осіб, переселених із зони АТО, становить 16,6 % субклінічно вираженої депресії – 46,7 % населення. Встановлено, що військовослужбовці та ветерани значною мірою відчувають напруження, страх перед невідомістю, вважають, що можуть легко розслабитись, часто бувають раптові відчуття паніки та дуже часто – відчувають внутрішнє напруження. Мирне населення, що перебувало в зоні АТО, теж характеризується помірним рівнем тривоги, який підтверджується частим відчуттям страху, що може щось трапитись, нечастими хвилюючими думками, частим відчуттям внутрішнього напруження. Порівнюючи отримані відповіді на твердження у блоці питань, що стосуються рівня депресії, можна говорити про середній рівень депресії у військовослужбовців та помірний – у цивільного населення, переселеного із зони АТО.

Висновки. Особи, які несли військову службу або перебували в зоні АТО, їх близькі родичі потребують психологічного супроводу при зверненні до медичного закладу будь-якого профілю. Медичні сестри повинні знати методи надання екстреної психологічної допомоги, тому рекомендується включити в освітню програму для медсестер освітнього рівня «Магістр» курс за вибором «Екстрена психологічна допомога».
СТАН КЛІТИННОГО ІМУНІТЕТУ В ЖІНОК ПРЕ- ТА МЕНОПАУЗАЛЬНОГО ВІКУ З ГІПЕРПЛАСТИЧНИМИ ПРОЦЕСАМИ ЕНДОМЕТРІЯ
Authors: Slyva A. F. , Selskyy P. R. , Kuziv O. Ye. , Slyva V. V.
Published: February 2020

Мета роботи. Вивчити стан клітинного імунітету в пацієнтів із гіперпластичними процесами ендометрія. Матеріали і методи. Вивчено біопсійний матеріал та проаналізовано показники клітинного імунітету в 33 жінок пре- та менопаузального віку, яких поділили на три групи: першу групу складали 11 жінок із простою гіперплазією ендометрія без атипії; другу – 2 жінки з простою атиповою гіперплазією ендометрія; третю групу – 20 жінок із комплексною гіперплазією ендометрія без атипії. Контрольну групу складали 12 жінок без ознак захворювань ендометрія. Проведено дослідження низки параметрів: визначення відносної та абсолютної кількості різних субпопуляцій лімфоцитів крові, циркулюючих імунних комплексів, показників функціональної та проліферативної активності імунних клітин у сироватці венозної крові. Результати й обговорення. У жінок з гіперпластичними процесами ендометрія виявлено виражені порушення імунологічного гомеостазу, які проявлялися Т-лімфоцитопенією, дисбалансом субпопуляцій Т-клітин, здебільшого за рахунок зниження циркулюючих Т-хелперів/індукторів, що супроводжувалось зниженням коефіцієнта CD4/CD8 та свідчило про формування вторинного імунодефіциту. Індивідуальний аналіз імунограм хворих із гіперпластичними процесами показав наявність імунодефіциту в усіх обстежуваних пацієнток, проте у жінок із простою гіперплазією без атипії він проявляється гіпосупресією, у хворих з простою атиповою гіперплазією ендометрія більш вираженим супресорним варіантом, а у жінок із комплексною гіперплазією ендометрія мало місце пропорційне зниження індексу CD4/CD8. Порушення функції імунітету виявлялося в різкому зниженні фагоцитарного індексу нейтрофілів у всіх жінок із гіперпластичними процесами ендометрія та зниженні проліферативної активності лімфоцитів у жінок із простою гіперплазією ендометрія без атипії й тенденцією до її підвищення у хворих із простою атиповою гіперплазією ендометрія. Висновки. В усіх пацієнток із різними видами гіперплазії ендометрія виявлено зростання дрібних циркулюючих імунних комплексів та збільшення концентрації середніх циркулюючих імунних комплексів у хворих із простою гіперплазією без атипії та комплексною гіперплазією ендометрія.
ЕПІДЕМІОЛОГІЯ ТА ОСНОВНІ ЧИННИКИ ГОСТРОГО РЕСПІРАТОРНОГО ДИСТРЕС-СИНДРОМУ
Authors: Savchuk S. O. , Synytsky I. M.
Published: February 2020

Мета роботи. Проаналізувати літературні джерела щодо поширеності та основних етіологічних чинників гострого респіраторного дистрес-синдрому.

Матеріали і методи. У дослідженні опрацьовано наукові публікації за останнє десятиліття, які доступні у мережі «Інтернет», ключовими словами були «гострий респіраторний дистрес-синдром», «гостре ураження легень».

Результати й обговорення. Узагальнюючи аналіз літературних джерел, можна говорити про прогрес у вивченні ГРДС, удосконалення термінів і понять, хоча й до сьогодні у наукових джерелах описано високу захворюваність і смертність від даного синдрому. Різні автори наголосили на появі цього синдрому при травматичному ушкодженні легень і голови, отруєннях газом або димом, аспірації шлункового вмісту і меконію, дифузній альвеолярній кровотечі, туберкульозі. Багато сучасних досліджень торкається розвитку ГРДС при пневмоніях. В останнє десятиліття встановлено, що розвитку ГРДС також сприяє хронічний алкоголізм. Наукові публікації свідчать про велике число позалегеневих патологій.

Висновки. Аналітичний огляд основних тенденцій наукових досліджень вказує на високу частоту гострого респіраторного дистрес-синдрому, що асоціюється зі зростанням смертності при цій патології. Це обґрунтовує необхідність подальшого розширення і поглиблення уявлень про основні патобіохімічні процеси, що розвиваються при цьому синдромі.
ЕКОНОМІЧНА СКЛАДОВА СТРАХОВОЇ МЕДИЦИНИ
Authors: Habor V. S. , Badiuk O. O.
Published: February 2020

Мета роботи. Проаналізувати витрати на охорону здоров’я населення й держави у сучасних реаліях страхової медицини.

Матеріали і методи. Теоретичним та методологічним підґрунтям статті стали офіційні документи Міністерства охорони здоров’я, праці вітчизняних і зарубіжних науковців, Internet-ресурси. Дослідження проведено із застосуванням методів теоретичного узагальнення, порівняльного аналізу, аналізу та синтезу, що дозволило проаналізувати економічні витрати на охорону здоров’я.

Результати й обговорення. Якщо розглядати здоров’я населення з позиції виробничої сили, то воно є невід’ємною частиною виробничого циклу, що є основою розвитку держави. Розуміння цього зумовлює великі витрати в економічно розвинутих країнах на охорону здоров’я. Чи можливо впровадити на даний час соціальне медичне страхування? Так, за умови розширення та доповнення законопроектів щодо медичного страхування, а також чіткого визначення процедур їх застосування. Проте особливої уваги потребує узгодження упровадження обов’язкового медичного страхування з українськими реаліями. Чи готова держава і роботодавці нести фінансову відповідальність за працівника? Питання дискутабельне.

Висновки. Впровадження соціального медичного страхування є доцільним для забезпечення комплексного лікування, забезпечення медикаментами; конт­ролю якості лікування, відповідного рівня підготовки лікарів. Ефективне функціонування страхової медицини можливе при стабільній економіці. Витрати бюджету на охорону здоров’я в 2019 р. в Україні становили в середньому 51 % від загального обсягу.
Initial Precipitants and Recurrence of Atrial Fibrillation
Authors: Wang Elizabeth Y. , Hulme Olivia L. , Khurshid Shaan , Weng Lu-Chen , Choi Seung Hoan , Walkey Allan J. , Ashburner Jeffrey M. , McManus David D. , Singer Daniel E. , Atlas Steven J. , Benjamin Emelia J. , Ellinor Patrick T. , Trinquart Ludovic , Lubitz Steven A.
Published: February 2020

Background:

Atrial fibrillation (AF) may occur after an acute precipitant and subsequently resolve. Management guidelines for AF in these settings are unclear as the risk of recurrent AF and related morbidity is poorly understood. We examined the relations between acute precipitants of AF and long-term recurrence of AF in a clinical setting.

Methods:

From a multi-institutional longitudinal electronic medical record database, we identified patients with newly diagnosed AF between 2000 and 2014. We developed algorithms to identify acute AF precipitants (surgery, sepsis, pneumonia, pneumothorax, respiratory failure, myocardial infarction, thyrotoxicosis, alcohol, pericarditis, pulmonary embolism, and myocarditis). We assessed risks of AF recurrence in individuals with and without a precipitant and the relations between AF recurrence and heart failure, stroke, and mortality.

Results:

Among 10 723 patients with newly diagnosed AF (67.9±9.9 years, 41% women), 19% had an acute AF precipitant, the most common of which were cardiac surgery (22%), pneumonia (20%), and noncardiothoracic surgery (15%). The cumulative incidence of AF recurrence at 5 years was 41% among individuals with a precipitant compared with 52% in those without a precipitant (adjusted hazard ratio [HR], 0.75 [95% CI, 0.69–0.81];
P
<0.001). The lowest risk of recurrence among those with precipitants occurred with postoperative AF (5-year incidence 32% in cardiac surgery and 39% in noncardiothoracic surgery). Regardless of the presence of an initial precipitant, recurrent AF was associated with increased adjusted risks of heart failure (hazard ratio, 2.74 [95% CI, 2.39–3.15];
P
<0.001), stroke (hazard ratio, 1.57 [95% CI, 1.30–1.90];
P
<0.001), and mortality (hazard ratio, 2.96 [95% CI, 2.70–3.24];
P
<0.001).

Conclusions:

AF after an acute precipitant frequently recurs, although the risk of recurrence is lower than among individuals without an acute precipitant. Recurrence is associated with substantial long-term morbidity and mortality. Future studies should address surveillance and management after newly diagnosed AF in the setting of an acute precipitant.
Potassium Disturbances and Risk of Ventricular Fibrillation Among Patients With ST‐Segment–Elevation Myocardial Infarction
Authors: Ravn Jacobsen Mia , Jabbari Reza , Glinge Charlotte , Kjær Stampe Niels , Butt Jawad Haider , Blanche Paul , Lønborg Jacob , Wendelboe Nielsen Olav , Køber Lars , Torp‐Pedersen Christian , Pedersen Frants , Tfelt‐Hansen Jacob , Engstrøm Thomas
Published: February 2020

Background

Potassium disturbances per se increase the risk of ventricular fibrillation (
VF
). Whether potassium disturbances in the acute phase of
ST
‐segment–elevation myocardial infarction (
STEMI
) are associated with
VF
before primary percutaneous coronary intervention (
PPCI
) is uncertain.

Methods and Results

All consecutive
STEMI
patients were identified in the Eastern Danish Heart Registry from 1999 to 2016. Comorbidities and medication use were assessed from Danish nationwide registries. Potassium levels were collected immediately before
PPCI
start. Multivariate logistic models were performed to determine the association between potassium and
VF
. The main analysis included 8624
STEMI
patients of whom 822 (9.5%) had
VF
before
PPCI
. Compared with 6693 (77.6%) patients with normokalemia (3.5–5.0 mmol/L), 1797 (20.8%) patients with hypokalemia (<3.5 mmol/L) were often women with fewer comorbidities, whereas 134 (1.6%) patients with hyperkalemia (>5.0 mmol/L) were older with more comorbidities. After adjustment, patients with hypokalemia and hyperkalemia had a higher risk of
VF
before
PPCI
(odds ratio 1.90, 95%
CI
1.57–2.30,
P
<0.001) and (odds ratio 3.36, 95%
CI
1.95–5.77,
P
<0.001) compared with normokalemia, respectively. Since the association may reflect a post‐resuscitation phenomenon, a sensitivity analysis was performed including 7929
STEMI
patients without
VF
before
PPCI
of whom 127 (1.6%) had
VF
during
PPCI
. Compared with normokalemia, patients with hypokalemia had a significant association with
VF
during
PPCI
(odds ratio 1.68, 95%
CI
1.01–2.77,
P
=0.045) after adjustment.

Conclusions

Hypokalemia and hyperkalemia are associated with increased risk of
VF
before
PPCI
during
STEMI
. For hypokalemia, the association may be independent of the measurement of potassium before or after
VF
.
Association of Neighborhood Race and Income With Survival After Out‐of‐Hospital Cardiac Arrest
Authors: Chan Paul S. , McNally Bryan , Vellano Kimberly , Tang Yuanyuan , Spertus John A.
Published: February 2020

Background

For individuals with an out‐of‐hospital cardiac arrest (OHCA), survival may be influenced by the neighborhood in which the arrest occurs.

Methods and Results

Within the national CARES (Cardiac Arrest Registry to Enhance Survival) registry, we identified 169 502 patients with OHCA from 2013 to 2017. On the basis of census tract data, OHCAs were categorized as occurring in predominantly white (>80% white), majority black (>50% black), or integrated (neither of these 2) neighborhoods and in low‐income (median household <$40 000), middle‐income ($40 000 to $80 000), or high‐income (>$80 000) neighborhoods. With hierarchical logistic regression, the association of neighborhood race and income on overall survival was assessed. Overall, 37.5%, 16.6%, and 45.9% of people had an OHCA in predominantly white, majority black, and integrated neighborhoods, and 30.1%, 53.4%, and 16.5% in low‐, middle‐, and high‐income neighborhoods, respectively. Compared with OHCAs occurring in predominantly white neighborhoods, those in majority black neighborhoods were 12% less likely (6.9% versus 10.6%; adjusted odds ratio 0.88; 95% CI 0.82‐0.95;
P
<0.001) to survive to discharge, whereas those in integrated neighborhoods had similar survival (10.3% versus 10.6%; adjusted odds ratio 1.00; 95% CI 0.96‐1.04;
P
=0.93). Compared with high‐income neighborhoods, those in middle‐income neighborhoods were 11% (10.1% versus 11.3%; adjusted odds ratio 0.89; 95% CI 0.8‐0.94;
P
<0.001) less likely to survive to discharge, whereas those in low‐income neighborhoods were 12% (8.6% versus 11.3%; adjusted odds ratio 95% CI 0.83‐0.94;
P
<0.001) less likely to survive. Differential rates of bystander cardiopulmonary resuscitation only modestly attenuated neighborhood differences in survival.

Conclusions

OHCAs in majority black and non–high‐income neighborhoods have lower survival rates, and these differences were not explained by differential bystander cardiopulmonary resuscitation rates.
Relation Between Leisure Time, Commuting, and Occupational Physical Activity With Blood Pressure in 125 402 Adults: The Lifelines Cohort
Authors: Byambasukh Oyuntugs , Snieder Harold , Corpeleijn Eva
Published: February 2020

Background

Whether all domains of daily‐life moderate‐to‐vigorous physical activity (
MVPA
) are associated with lower blood pressure (
BP
) and how this association depends on age and body mass index remains unclear.

Methods and Results

In the population‐based Lifelines cohort (N=125 402),
MVPA
was assessed by the Short Questionnaire to Assess Health‐Enhancing Physical Activity, a validated questionnaire in different domains such as commuting, leisure‐time, and occupational
PA
.
BP
was assessed using the last 3 of 10 measurements after 10 minutes’ rest in the supine position. Hypertension was defined as systolic
BP
≥140 mm Hg and/or diastolic
BP
≥90 mm Hg and/or use of antihypertensives. In regression analysis, higher commuting and leisure‐time but not occupational
MVPA
related to lower
BP
and lower hypertension risk. Commuting‐and‐leisure‐time
MVPA
was associated with
BP
in a dose‐dependent manner. β Coefficients (95%
CI
) from linear regression analyses were −1.64 (−2.03 to −1.24), −2.29 (−2.68 to −1.90), and finally −2.90 (−3.29 to −2.50) mm Hg systolic
BP
for the low, middle, and highest tertile of
MVPA
compared with “No
MVPA
” as the reference group after adjusting for age, sex, education, smoking and alcohol use. Further adjustment for body mass index attenuated the associations by 30% to 50%, but more
MVPA
remained significantly associated with lower
BP
and lower risk of hypertension. This association was age dependent. β Coefficients (95%
CI
) for the highest tertiles of commuting‐and‐leisure‐time MVPA were −1.67 (−2.20 to −1.15), −3.39 (−3.94 to −2.82) and −4.64 (−6.15 to −3.14) mm Hg systolic
BP
in adults <40, 40 to 60, and >60 years, respectively.

Conclusions

Higher commuting and leisure‐time but not occupational
MVPA
were significantly associated with lower
BP
and lower hypertension risk at all ages, but these associations were stronger in older adults.