bluuebunny/crossref_metadata_2025 huggingface dataset:
Institutional rental housing market – new approaches and formats
Authors: Yu Gorbachevskaya E , Gimelshtein I V
Published: May 2021

Russia needs to create an institutional, civilized commercial rental market. its practical absence today limits the territorial mobility of the population and significantly reduces the flexibility of the labor market. To accelerate the mechanisms of economic development by attracting the best specialists and retaining their own human capital, it is possible that this will make commercial rental housing available in the largest cities with full legal protection of the tenant and owner from fraud. The development of the rental market is influenced by many factors: demand and preferences from potential consumers, availability of financial resources, technical and technological capabilities, population structure, etc. All this determines the requirements for new rental housing formats and makes it necessary to develop new investment mechanisms. The article discusses the current state of the rental housing segment in Russia. Most attention is paid to the developing formats of rental housing such as apartments, coliving and retirement homes. Their characteristics, classifications and prospects for the development of construction of such projects in Russia are presented. The rental segment of the residential real estate market creates new prospects for the spatial development of cities and regions, improving the situation related to personnel problems at large enterprises and increasing the mobility of the population.
Development of civil engineering financing forms and their influence on the development’s economy
Authors: Kogan A B
Published: May 2021

The purpose of this work is to study the influence of financing housing construction methods on the financial and economic characteristics of projects for apartment buildings construction (AB) and on price level of the primary Residential Real Estate Market. The methodological foundations of the research work are the rules for financing housing construction and other standards in this area, tax standards, rules for developing construction schedules, methods for assessing the investments effectiveness. Theoretical foundations of work are the work of leading scientists in the field of real estate development, provisions on the rules of pricing in the primary Real Estate Market, provisions of the finance and entrepreneurship theories. Information bases of work are market information on the primary Real Estate Market state (Novosibirsk) and the estimated cost of apartment buildings. The evolution of financing housing construction methods in the Russian Federation is described. Two modern methods are considered: financing with the use of agreements for participation in shared construction and financing, using real estate purchase and sale agreements (PSA). On the example of an apartment building, created in the city of Novosibirsk, calculations were made of the project implementation results for the AB construction, using both funding methods: (PAShC and PSA). The contradictions of the indicators describing these results are shown and explained (using PSA, the profit is higher; however, the internal rate is higher, using PAShC). The assessment of the initiative implementation consequences to ban PAShC is given.
Innovative technologies in the Russian construction industry as a factor of economic development
Authors: Timchuk O G , Kazantseva I I
Published: May 2021

The construction sector is a priority area of the economy, which affects the quality of life of the population. The dynamics of construction is one of the key indicators by which one can judge the economic and social development of the country. At the same time, in recent decades the investment and construction industry of Russia experiences a number of problems that hinder its development. First of all, they include a low proportion of qualified personnel; underdevelopment of the competitive environment due to a relatively low share of small and medium-sized enterprises in the structure of the construction industry; poor legal regulation of the construction sector; low investment efficiency; inconsistency of building codes and regulations with modern requirements for construction projects; the lack of a well-developed mechanism for coordinating inter-firm interactions. The article discusses the main factors influencing the innovative development of enterprises in the construction industry. The system of indicators characterizing the structural components of the innovative potential of the enterprise is presented. The authors have developed an organizational economic mechanism for implementing innovations in the construction sector.
Prediction of dissolved oxygen content in water based on EEMD-Pearson and LSTM hybrid models
Authors: Li Qihua , Wang Xin , Wang Jiangying , Zhou Yun
Published: May 2021

Improving the accuracy of dissolved oxygen (DO) prediction and establishing a water body DO prediction model are of great importance in water environment pollution management and planning management. In this paper, we propose a hybrid model (EEMD-Pearson-LSTM) of ensemble empirical modal decomposition-Pearson analysis and long-short memory neural network (LSTM), which firstly uses EEMD to decompose the non-stationary dissolved oxygen data into several sub-series that are easy to analyze, and secondly uses Pearson correlation analysis method to The screened subsequences are input to the LSTM network for training and prediction. By establishing the conventional LSTM model, EEMD-LSTM model, EEMD-BP model, and EEMD-Pearson-BP model for comparison under different time periods, root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and coefficient of determination (R2) were used as evaluation indicators. In predicting the first 90 days of data, the RMSE, MAE, MAPE, and R2 of the EEMD-Pearson-LSTM model were 0.2355, 0.1893, 2.4710, and 0.8787, respectively, which were optimized by 37.88%, 35.44%, 37.42%, and 28.15%, respectively, compared with the traditional LSTM model, and the EEMD- LSTM model by 13.74%, 16.46%, 16.82%, and 4.98%, respectively, and the error of EEMD-BP network by 23.93%, 22.70%, and 24.32%, respectively, and its R2 by 11.17%, and the error of EEMD-Pearson-BP network by 18.62%, 14.07%, and 14.44%, and its R2 improved by 7.58%. To further demonstrate the advantages of EEMD-Pearson-LSTM, the prediction models for 30-day and 60-day time periods were selected for comparison, and the results showed that EEMD-Pearson-LSTM outperformed other models for the prediction of dissolved oxygen content in different time periods.
Effects of aging methods on properties of rubber powder modified asphalt
Authors: Kaikai Gao , Abulimiti Nuermaimaiti , Zhiqiang Huo , Zheng Xun Yang , Fang Chen
Published: May 2021

Three types of aging methods were conducted on rubber powder modified asphalt, and the basic physical properties test, dynamic shear rheological test and infrared spectrum analysis were adopted to study the effect of aging methods on properties of rubber powder modified asphalt comprehensively. Results show that effects of different aging methods on physical properties of rubber powder modified asphalt are inconsistent. There is a slight influence of aging on its rheological properties, which means a better aging resistance. Through microanalysis, it can be found that there is a significant aging for rubber powder modified asphalt after pressurized aging, followed by the ultraviolet aging. The aging degree of rubber powder modified asphalt is relatively small after short-term thermal-oxidative aging.
Migration and transformation of three nitrogen in groundwater and antipollution effect of aquitard in North China Plain typical area
Authors: Zhao Yanjie , Deng Yirong , Lu Haijian , Lv Mingchao , Cheng Zhou
Published: May 2021

The “three nitrogen” (NH4
+-N, NO2
—N, NO3
−-N) pollution of groundwater in north China plain region endanger the groundwater ecological environment. In this study, we chose the typical area of North China Plain as the representative research area. By numerical method, we analyzed the migration characteristics of “three nitrogen” pollutants in the 200 year time scale in different representative strata structural modes of shallow groundwater system in this area. Based on the simulation results, the retardant ability of the unit thickness of aquitard was analyzed. The results were as follows: 1 The migration of different kinds of “three nitrogen” pollutants in the aquifer system were different; (2) The strata structural characteristics have obvious effects on the migration of “three nitrogen”, and their influence rules were different. The three representative strata structure models were constructed on the basis of comprehensive analyzing the regional strata features. Therefore, the simulation results have reference value for evaluation of the “three nitrogen” migration and the retardant ability of the aquitard in this area.
Study on the properation and properties of PP/mental aluminium power composites
Authors: Dou Yanli , Huang Jiaming , Yao Weiguo , Li Jinliang , Guan Dongbo
Published: May 2021

In this paper, polypropylene(PP) was blended with aluminum powder, porous powder and EVOH reinforcing agent in different proportions by melt blending method. The infrared spectrum analysis of the blending components was carried out to study the tensile strength, impact strength, ball indentation hardness and heat resistance of the composites with different proportions. The results show that when the content of aluminum powder is 2 wt.%, the content of porous powder is 9 wt.%, and the content of EVOH is 4 wt.%, the heat resistance of the composite is the best. The tensile strength, impact strength and hardness of the composite are 21.33 MPa, 1.83 MPa and 74.78 N/mm 2, respectively. At this time, the composite has the best comprehensive properties.
Dynamic prediction model of bridge project life cycle cost investment based on decision tree algorithm
Authors: Li Jing , Li Xu , Zhang Zhuoqun
Published: May 2021

In order to further improve the dynamic prediction effect of bridge engineering life cycle cost, a life cycle cost prediction model of bridge engineering is established by using decision tree algorithm, and the influence coefficient of bridge engineering characteristics on cost is analyzed by data acquisition method. After analysis, the project characteristics which have great influence on the cost of bridge engineering are determined. The decision tree algorithm is used to establish the dynamic prediction model of bridge engineering life cycle cost; through MATLAB software, a good bridge cost prediction model is gradually established, and the model is trained, modified and verified according to the actual engineering data. The dynamic prediction model of life cycle cost investment of bridge engineering is established by using decision tree algorithm, which effectively improves the prediction accuracy and has strong practicability.
The Convertibility Forecast Model of Space Structure in Architecture Programming——Collective Housing in Taiwan for example
Authors: Shyng  , Jyh-Harng
Published: May 2021

House refurbishment related to the convertibility of space organizations is nowadays a common phenomenon in Taiwan, reflecting user demands for the diversity of unit plane and space expansion in quantity, and forming an important research topic over the implementation of sustainable development concept in living environment. In this paper, apartment mansion-type amalgamated dwellings were quantitatively analyzed and investigated, and four models, which were dimension combinations of influence factors, were compared through the field survey and logistic regression model (binary regression method). The results showed that the variables in Model IV consisted of three dimensions—space organization, building entity and spatial planning, with the optimal prediction rate (74.5%), so it was regarded as a convertibility prediction model of space organization; the significance and goodness of fit of each model were analyzed by comparing each variable coefficient with the expected symbol, and next, the concrete meaning of each influence factor belonging to each dimension of each model was indicated by means of coefficient correction, which could further predict the convertibility of space organizations, accurately obtain the factors influencing the convertibility prediction, and improve the prediction accuracy. This research, which conforms to the concept of sustainable environmental development, will contribute to construction project planning and design of residential buildings.
Finite Element Analysis of Pipe Shed Pre-Supporting Reinforcement Effect on A Shallow-Buried Tunnel
Authors: Su Jianping , Wang Tao
Published: May 2021

Under the engineering background of crushed zone at the entrance section of a shallow-buried soft rock tunnel, the 3D finite element simulation of pipe shed pre-reinforcement measures was implemented under different diameters, lengths, and spacing via Midas Civil software after the excavation of tunnel portal, in an effort to analyze the reinforcement principle of pipe shed grouting reinforcement method during the tunnel excavation process. The stress-induced deformation laws of the support system were summarized, and the reinforcement effect of pipe shed grouting method was analyzed. The results show that with the increase in diameter of pipe shed, the maximum deformation of pipe shed is obviously reduced, and the favorable effect is reached when the diameter of pipe shed is within 300-600 mm. As the pipe shed extends to the undisturbed zone of soil mass, the change in length has a very minor effect on the deformation of pipe shed, while the deformation is greatly impacted by the excavation footage, and the deformation becomes the most significant after the excavation footage becomes greater than 1.5 m.
Large eddy simulation of the variable density mixing layer
Authors: Huang J X , Hug S N , McMullan W A
Published: May 2021

In this paper we perform large eddy simulations of variable density mixing layers, which originate from initially laminar conditions. The aim of this work is to capture the salient flow physics present in the laboratory flow. This is achieved through varying the nature of the inflow condition, and assessing the vortex structure present in the flow. Two distinct inflow condition types are studied; the first is an idealised case obtained from a mean inflow velocity profile with superimposed pseudo-white-noise, and the second is obtained from an inflow generation technique. The inflow conditions generated have matching mean and root mean squared statistics. Validation of the simulations is achieved through grid dependency and subgrid-scale model testing. Regardless of the inflow condition type used, the change in growth rate of the mixing layer caused by the density ratio is captured. It is found that the spacing of the large-scale spanwise structure is a function of the density ratio of the flow. Detailed interrogation of the simulations shows that the streamwise vortex structure present in the mixing layer depends on the nature of the imposed inflow condition. Where white-noise fluctuations provide the inflow disturbances, a spatially-stationary streamwise structure is absent. Where the inflow generator is used, a spatially stationary streamwise structure is present, which appears as streaks in plan-view visualisations. The stationary streamwise structure evolves such that the ratio of streamwise structure wavelength to local vorticity thickness asymptotes to unity, independent of the density ratio. This value is in agreement with previous experimental studies. Recommendations are made on the requirements of inflow condition modelling for accurate mixing layer simulations.
Tailoring a sub-diffraction optical focus via a straightforward interferometric approach
Authors: Neyra Enrique G , Vaveliuk Pablo
Published: May 2021

An approach for yielding light focuses below Abbe’s diffraction limit in Gaussian beams is presented. The method uses only standard passive optical elements as lenses, filters and mirrors and consists of a Michelson interferometric setup, where one of the light branches is modified in amplitude and/or phase. The focus narrowing process is carried out at the focal plane of a spherical lens by the interference of altered and unaltered light branches. The main focus features, namely, the focus intensity and size as well as the sidelobe intensity, are adjusted by varying two external parameters in a controllable manner under the conditions of pure destructive interference. Narrowing of the diffraction limit close to 40% with reduced intensity sidelobes (10%) is achieved. Due to the use of only lenses and mirrors, the approach does work with laser beams within a broad optical bandwidth ranging from infrared to ultraviolet in continuum regime as well as in ultra-short pulse regime. The method can also be implemented for high-power lasers and temporal domains. The focus-narrowing process emerges as a natural mechanism to the light interference, bringing a fresh perspective to applications from a few controllable degrees of freedom. The good performance of the sub-diffraction optical focus and the simplicity of the experimental setup promote new opportunities in fields ranging from optical manipulation of particles at sub-wavelength scale to optical writing and super-resolution microscopy.
Suspended graphene on germanium: selective local etching via laser-induced photocorrosion of germanium
Authors: Binder Johannes , Rogoza Jakub , Tkachenko Leonid , Pasternak Iwona , Sitek Jakub , Strupinski Wlodek , Zdrojek Mariusz , Baranowski Jacek M , Stepniewski Roman , Wysmolek Andrzej
Published: May 2021

The implementation of graphene in nanoelectromechanical systems and electronic applications requires not only techniques to fabricate high-quality monolayers, but also methods to process these layers. Nondestructive processing is especially challenging in the case of fragile suspended graphene membranes. In this work, we present a direct writing method for graphene grown on germanium that yields suspended layers without the need to transfer the graphene layer. To this end, we employ laser-induced photoelectrochemical etching which is highly selective and dissolves only germanium leaving the graphene layer intact. Only a focused continuous wave laser beam and water (or an aqueous solution) are required for the etching to proceed. Raman spectroscopy measurements were performed in-situ to monitor the etching process. These measurements reveal a dramatic increase of the graphene-related Raman bands as the graphene layer detaches from the substrate. This substantial increase indicates that the commonly observed weak Raman signal for graphene on germanium is not an inherent material property but is due to the interaction of the germanium substrate with graphene. Together with the established graphene growth on germanium, the presented direct writing method builds a complete toolbox for graphene membrane-based applications.
Plasmonic waveguides from Coulomb-engineered two-dimensional metals
Authors: Jiang Zhihao , Haas Stephan , Rösner Malte
Published: May 2021

Coulomb interactions play an essential role in atomically-thin materials. On one hand, they are strong and long-ranged in layered systems due to the lack of environmental screening. On the other hand, they can be efficiently tuned by means of surrounding dielectric materials. Thus all physical properties which decisively depend on the exact structure of the electronic interactions can be in principle efficiently controlled and manipulated from the outside via Coulomb engineering. Here, we show how this concept can be used to create novel plasmonic waveguides in metallic layered materials. We discuss how dielectrically structured environments can be utilized to non-invasively confine plasmonic excitations in an unperturbed homogeneous metallic two-dimensional system by modifications of its many-body interactions. We define optimal energy ranges for this mechanism and demonstrate plasmonic confinement within several nanometers. In contrast to conventional functionalization mechanisms, this scheme relies on a purely many-body concept and does not involve any direct modifications to the active material itself.
Renormalization functions of the tricritical O(N)-symmetric Φ6 model beyond the next-to-leading order in 1/N
Authors: Sakhi S
Published: May 2021

We investigate higher-order corrections to the effective potential of the tricritical O(N)-symmetric

Φ

6

model in 3-2ε dimensions in its phase exhibiting spontaneous breaking of its scale symmetry. The renormalization group β-function and the anomalous dimension γ of this model are computed up to the next-to-next-to-leading order in the1/N expansion technique and using a dimensional regularization in a minimal subtraction scheme.
Using pulsed mode scanning electron microscopy for cathodoluminescence studies on hybrid perovskite films
Authors: Ferrer Orri Jordi , Tennyson Elizabeth M , Kusch Gunnar , Divitini Giorgio , Macpherson Stuart , Oliver Rachel A , Ducati Caterina , Stranks Samuel D
Published: May 2021

The use of pulsed mode scanning electron microscopy cathodoluminescence (CL) for both hyperspectral mapping and time-resolved measurements is found to be useful for the study of hybrid perovskite films, a class of ionic semiconductors that have been shown to be beam sensitive. A range of acquisition parameters is analysed, including beam current and beam mode (either continuous or pulsed operation), and their effect on the CL emission is discussed. Under optimized acquisition conditions, using a pulsed electron beam, the heterogeneity of the emission properties of hybrid perovskite films can be resolved via the acquisition of CL hyperspectral maps. These optimized parameters also enable the acquisition of time-resolved CL of polycrystalline films, showing significantly shorter lived charge carriers dynamics compared to the photoluminescence analogue, hinting at additional electron beam-specimen interactions to be further investigated. This work represents a promising step to investigate hybrid perovskite semiconductors at the nanoscale with CL.
Electrospinning fabrication of polystyrene-silica hybrid fibrous membrane for high-efficiency air filtration
Authors: Tang Hongzhe , Han Dong , Zhang Jian
Published: May 2021

The development of new materials for air filtration and particulate matter (PM) pollution is critical to solving global environmental issues that threaten human health and accelerate the greenhouse effect. In this study, a novel electrospun polystyrene-SiO2 nanoparticle (PS-SNP) fibrous membrane was explored by a single-step strategy to obtain the composite multi-layered filter masks. In addition, the air filtration performance of this fibrous membrane for PM was evaluated. The effects of SiO2 on the composition, morphology, mechanical property, and surface wetting of PS-SNP membranes were studied. Allowing SiO2 to be incorporated into the PS polymer was endowed with promising superhydrophobicity and demonstrated excellent mechanical properties. As-prepared PS-SNP membranes possess significantly better filtration efficiency than pure PS membrane. Furthermore, a three-layered air filter media (viscose/PS-SNP/polyethylene terephthalate) used in this study has considerable performances compared to the commercial masks. Since this air filtration membrane has excellent features such as high air filtration and permeability, we anticipate it to have huge potential application in air filtration systems, including cleanroom, respirator, and protective clothing.
Bistability in the polarity circuit of yeast
Authors: Errede Beverly , Hladyshau Siarhei , Nivedita Nivedita , Tsygankov Denis , Elston Timothy C.
Published: May 2021

Cells polarize their growth or movement in many different physiological contexts. A key driver of polarity is the Rho GTPase Cdc42, which when activated becomes clustered or concentrated at polar sites. Multiple models for polarity establishment have been proposed. All of them rely on positive feedback to reinforce regions of high Cdc42 activity. Positive feedback can lead to bistability, a scenario in which cells can exist in either a polarized or unpolarized state under identical external conditions. Determining if the signaling circuit that drives Cdc42 polarity is bistable would provide important information about the mechanism that underlies polarity establishment and insights into the design features required for proper cellular function. We studied polarity establishment during the mating response of yeast. Using microfluidics to precisely control the temporal profile of mating pheromone and live-cell imaging to monitor the polarity process in single living cells, we found that the polarity circuit of yeast shows hysteresis, a characteristic feature of bistable systems. Our analysis also revealed that cells exposed to high pheromone concentrations rapidly lose polarity following a precipitous removal of pheromone. We used a reaction-diffusion model for polarity establishment to demonstrate that delayed negative regulation is sufficient to explain our experimental results.

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The 3D-Transition Study: Objectives, Methods, and Implementation of an Innovative Planned Missing-Data Design
Authors: Rioux Charlie , Parent Sophie , Castellanos-Ryan Natalie , Archambault Isabelle , Boivin Michel , Herba Catherine M , Lupien Sonia J , Marc Isabelle , Muckle Gina , Fraser William D , Séguin Jean R
Published: May 2021

The prevalence of mental health problems represents a significant burden on school and community health resources as early as preschool. Reducing this burden requires a better understanding of the developmental mechanisms linking children’s early vulnerabilities with mental health after the transition to formal schooling. The 3D-Transition Study (2017–2021) follows 939 participants from a pregnancy cohort in the province of Québec, Canada, as they transition to kindergarten and first grade to examine these mechanisms. Biannual assessments include completed questionnaires from 2 parents as well as teachers, parent-child observations, anthropometric measurements, and age-sensitive cognitive assessments. Saliva is also collected on 11 days over a 16-month period in a subsample of 384 participants to examine possible changes in child salivary cortisol levels across the school transition and their role in difficulties observed during the transition. A combination of planned missing-data designs is being implemented to reduce participant burden, where incomplete data are collected without introducing bias after the use of multiple imputation. The 3D-Transition Study will contribute to an evidence-based developmental framework of child mental health from pregnancy to school age. In turn, this framework can help inform prevention programs delivered in health-care settings during pregnancy and in child-care centers, preschools, and schools.
Truth and truthiness: evidence, experience and clinical judgement in surgery
Authors: Matthews Jeffrey B
Published: May 2021

The scientific basis of surgery, derived through observation and experiment, does not fully account for surgical expertise gained through experience. The evidence that supports surgical practice is limited, elusive, and subject to bias. Surgical judgment requires not only explicit, fact-based, knowledge but also tacit forms of understanding that are not easily teachable or testable.
Serum and cerebrospinal fluid biomarker profiles in acute SARS-CoV-2-associated neurological syndromes
Authors: Paterson Ross W , Benjamin Laura A , Mehta Puja R , Brown Rachel L , Athauda Dilan , Ashton Nicholas J , Leckey Claire A , Ziff Oliver J , Heaney Judith , Heslegrave Amanda J , Benedet Andrea L , Blennow Kaj , Checkley Anna M , Houlihan Catherine F , Mummery Catherine J , Lunn Michael P , Manji Hadi , Zandi Michael S , Keddie Stephen , Chou Michael , Vinayan Changaradil Deepthi , Solomon Tom , Keshavan Ashvini , Barker Suzanne , Jäger Hans Rolf , Carletti Francesco , Simister Robert , Werring David J , Spyer Moira J , Nastouli Eleni , Gauthier Serge , Rosa-Neto Pedro ,   The UCLH Queen Square COVID-19 Biomarker Study Group, Ashraghi Mohammed R , Balendra Rubika , Kumar Guru , Lim Soon Tjin , Longley Nicki , Samra Kiran , Chandratheva Arvind , Cohen Hannah , Efthymiou Maria , Zambreanu Laura , Foulkes Alexander , Zetterberg Henrik , Schott Jonathan M
Published: May 2021

Preliminary pathological and biomarker data suggest that SARS-CoV-2 infection can damage the nervous system. To understand what, where and how damage occurs, we collected serum and CSF from patients with COVID-19 and characterized neurological syndromes involving the PNS and CNS (n = 34). We measured biomarkers of neuronal damage and neuroinflammation, and compared these with non-neurological control groups, which included patients with (n = 94) and without (n = 24) COVID-19. We detected increased concentrations of neurofilament light, a dynamic biomarker of neuronal damage, in the CSF of those with CNS inflammation (encephalitis and acute disseminated encephalomyelitis) [14 800 pg/ml (400, 32 400)], compared to those with encephalopathy [1410 pg/ml (756, 1446)], peripheral syndromes (Guillain–Barré syndrome) [740 pg/ml (507, 881)] and controls [872 pg/ml (654, 1200)]. Serum neurofilament light levels were elevated across patients hospitalized with COVID-19, irrespective of neurological manifestations. There was not the usual close correlation between CSF and serum neurofilament light, suggesting serum neurofilament light elevation in the non-neurological patients may reflect peripheral nerve damage in response to severe illness. We did not find significantly elevated levels of serum neurofilament light in community cases of COVID-19 arguing against significant neurological damage. Glial fibrillary acidic protein, a marker of astrocytic activation, was not elevated in the CSF or serum of any group, suggesting astrocytic activation is not a major mediator of neuronal damage in COVID-19.
Desirability of Outcome Ranking for the Management of Antimicrobial Therapy (DOOR MAT) Reveals Improvements in the Treatment of Bloodstream Infections Caused by Escherichia coli and Klebsiella pneumoniae in Patients from the Veterans Health Administration
Authors: Perez Federico , Colindres Roberto Viau , Wilson Brigid M , Saade Elie , Jump Robin L P , Banerjee Ritu , Patel Robin , Evans Scott R , Bonomo Robert A
Published: May 2021

Background

Reductions in the use of broad-spectrum antibiotics is a cornerstone of antimicrobial stewardship. We aim to demonstrate use of the Desirability of Outcome Ranking Approach for the Management of Antimicrobial Therapy (DOOR MAT) to evaluate the treatment of Escherichia coli and Klebsiella pneumoniae bloodstream infections in patients from the Veterans Health Administration (VHA) across a decade.

Methods

Using electronic records, we determined empiric and definitive antibiotic treatments, clinical characteristics, and 30-day mortality of patients with monomicrobial E. coli and K. pneumoniae bloodstream infections hospitalized in VHA medical centers from 2009 to 2018. Focusing on patients treated with parenteral β-lactams and with available antibiotic susceptibility testing results, we applied a range of DOOR MAT scores that reflect the desirability of antibiotic choices according to spectrum and activity against individual isolates. We report trends in resistance and desirability of empiric and definitive antibiotic treatments.

Results

During the 10-year period analyzed, resistance to expanded-spectrum cephalosporins and fluoroquinolones increased in E. coli but not in K. pneumoniae, while resistance to carbapenems and piperacillin-tazobactam remained unchanged. In 6451 cases analyzed, we observed improvements in DOOR MAT scores consistent with deescalation. Improvement in desirability of definitive treatment compared with empiric treatment occurred in 26% of cases, increasing from 16% in 2009 to 34% in 2018. Reductions in overtreatment were sustained and without negative impact on survival.

Conclusions

DOOR MAT provides a framework to assess antibiotic treatment of E. coli and K. pneumoniae bloodstream infections and can be a useful metric in antimicrobial stewardship.
Cruise Ship Travel in the Era of Coronavirus Disease 2019 (COVID-19): A Summary of Outbreaks and a Model of Public Health Interventions
Authors: Guagliardo Sarah Anne J , Prasad Pragati V , Rodriguez Andrea , Fukunaga Rena , Novak Ryan T , Ahart Lauren , Reynolds Jared , Griffin Isabel , Wiegand Ryan , Quilter Laura A S , Morrison Stephanie , Jenkins Keisha , Wall Hilary K , Treffiletti Aimee , White Stefanie B , Regan Joanna , Tardivel Kara , Freeland Amy , Brown Clive , Wolford Hannah , Johansson Michael A , Cetron Martin S , Slayton Rachel B , Friedman Cindy R
Published: May 2021

Background

Cruise travel contributed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission when there were relatively few cases in the United States. By 14 March 2020, the Centers for Disease Control and Prevention (CDC) issued a No Sail Order suspending US cruise operations; the last US passenger ship docked on 16 April.

Methods

We analyzed SARS-CoV-2 outbreaks on cruises in US waters or carrying US citizens and used regression models to compare voyage characteristics. We used compartmental models to simulate the potential impact of 4 interventions (screening for coronavirus disease 2019 (COVID-19) symptoms; viral testing on 2 days and isolation of positive persons; reduction of passengers by 40%, crew by 20%, and reducing port visits to 1) for 7-day and 14-day voyages.

Results

During 19 January to 16 April 2020, 89 voyages on 70 ships had known SARS-CoV-2 outbreaks; 16 ships had recurrent outbreaks. There were 1669 reverse transcription polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infections and 29 confirmed deaths. Longer voyages were associated with more cases (adjusted incidence rate ratio, 1.10, 95% confidence interval [CI]: 1.03–1.17, P < .003). Mathematical models showed that 7-day voyages had about 70% fewer cases than 14-day voyages. On 7-day voyages, the most effective interventions were reducing the number of individuals onboard (43.3% reduction in total infections) and testing passengers and crew (42% reduction in total infections). All four interventions reduced transmission by 80.1%, but no single intervention or combination eliminated transmission. Results were similar for 14-day voyages.

Conclusions

SARS-CoV-2 outbreaks on cruises were common during January–April 2020. Despite all interventions modeled, cruise travel still poses a significant SARS-CoV-2 transmission risk.
Secure and Differentiated Fog-Assisted Data Access for Internet of Things
Authors: Yu Ping , Ni Wei , Zhang Hua , Ping Liu Ren , Wen Qiaoyan , Li Wenmin , Gao Fei
Published: May 2021

The ability of Fog computing to admit and process huge volumes of heterogeneous data is the catalyst for the fast expansion of Internet of things (IoT). The critical challenge is secure and differentiated access to the data, given limited computation capability and trustworthiness in typical IoT devices and Fog servers, respectively. This paper designs and develops a new approach for secure, efficient and differentiated data access. Secret sharing is decoupled to allow the Fog servers to assist the IoT devices with attribute-based encryption of data while preventing the Fog servers from tampering with the data and the access structure. The proposed encryption supports direct revocation and can be decoupled among multiple Fog servers for acceleration. Based on the decisional $q$-parallel bilinear Diffie–Hellman exponent assumption, we propose a new extended $q$-parallel bilinear Diffie–Hellman exponent (E$q$-PBDHE) assumption and prove that the proposed approach provides ‘indistinguishably chosen-plaintext attacks secure’ data access for legitimate data subscribers. As numerically and experimentally verified, the proposed approach is able to reduce the encryption time by 20% at the IoT devices and by 50% at the Fog network using parallel computing as compared to the state of the art .
LraSched: Admitting More Long-Running Applications via Auto-Estimating Container Size and Affinity
Authors: Cai Binlei , Guo Qin , Yu Junfeng
Published: May 2021

Many long-running applications (LRAs) are increasingly using containerization in shared production clusters. To achieve high resource efficiency and LRA performance, one of the key decisions made by existing cluster schedulers is the placement of LRA containers within a cluster. However, they fail to account for estimating the size and affinity of LRA containers before executing placement. We present LraSched, a cluster scheduler that places LRA containers onto machines based on their sizes and affinities while providing consistently high performance. LraSched introduces an automated method that leverages historical data and collects new information to estimate container size and affinity for an LRA. Specifically, it uses an online machine learning method to map a new incoming LRA to previous workloads from which we can transfer experience and recommends the amount of resources (size) and the degree of collocation (affinity) for the containers of the new incoming LRA. By means of recommendations, LraSched adapts the heuristic for vector bin packing to LRA scheduling and places LRA containers in a manner that both maximizes the number of LRAs deployed and minimizes the resource fragmentation, but without affecting LRA performance. Testbed and simulation experiments show that LraSched can improve the resource utilization by up to 6.2% while meeting performance constraints for LRAs.
Utility of wearable physical activity monitors in cardiovascular disease: a systematic review of 11 464 patients and recommendations for optimal use
Authors: Hammond-Haley Matthew , Allen Christopher , Han Jennie , Patterson Tiffany , Marber Michael , Redwood Simon
Published: May 2021

Aims

Physical activity (PA) plays an important role in primary and secondary prevention of cardiovascular disease (CVD), functioning as a marker of disease progression and response to therapy. Real-world measurement of habitual PA is now possible through wearable activity monitors, however, their use in cardiovascular patients is not well described.

Methods and results

We performed a systematic review to summarize how wearable activity monitors have been used to measure PA in patients with CVD, with 11 464 patients included across 108 studies. Activity monitors were primarily used in the setting of cardiac rehabilitation (46, 43%). Most often, triaxial accelerometers (70, 65%) were instructed to be worn at the hip (58, 54%) for 7 days (n = 54, 50%). Thirty-nine different activity monitors were used, with a range of accelerometer specific settings for collection and reporting of activity data. Activity was reported most commonly as time spent in metabolic equivalent-defined activity levels (49, 45%), while non-wear time was defined in just 16 (15%) studies.

Conclusion

The collecting, processing, and reporting of accelerometer-related outcomes were highly heterogeneous. Most validation studies are limited to healthy young adults, while the paucity of methodological information disclosed renders interpretation of results and cross-study comparison challenging. While accelerometers are promising tools to measure real-world PA, we highlight current challenges facing their use in elderly multimorbid cardiology patients. We suggest recommendations to guide investigators using these devices in cardiovascular research. Future work is required to determine optimal methodology and consensus-based development of meaningful outcomes using raw acceleration data.
SCORE2-OP risk prediction algorithms: estimating incident cardiovascular event risk in older persons in four geographical risk regions
Authors:   SCORE2-OP working group and ESC Cardiovascular risk collaboration, de Vries Tamar I , Cooney Marie Therese , Selmer Randi M , Hageman Steven H J , Pennells Lisa A , Wood Angela , Kaptoge Stephen , Xu Zhe , Westerink Jan , Rabanal Kjersti S , Tell Grethe S , Meyer Haakon E , Igland Jannicke , Ariansen Inger , Matsushita Kunihiro , Blaha Michael J , Nambi Vijay , Peters Ruth , Beckett Nigel , Antikainen Riitta , Bulpitt Christopher J , Muller Majon , Emmelot-Vonk Marielle H , Trompet Stella , Jukema Wouter , Ference Brian A , Halle Martin , Timmis Adam D , Vardas Panos E , Dorresteijn Jannick A N , De Bacquer Dirk , Di Angelantonio Emanuele , Visseren Frank L J , Graham Ian M
Published: May 2021

Aims 

The aim of this study was to derive and validate the SCORE2-Older Persons (SCORE2-OP) risk model to estimate 5- and 10-year risk of cardiovascular disease (CVD) in individuals aged over 70 years in four geographical risk regions.

Methods and results 

Sex-specific competing risk-adjusted models for estimating CVD risk (CVD mortality, myocardial infarction, or stroke) were derived in individuals aged over 65 without pre-existing atherosclerotic CVD from the Cohort of Norway (28 503 individuals, 10 089 CVD events). Models included age, smoking status, diabetes, systolic blood pressure, and total- and high-density lipoprotein cholesterol. Four geographical risk regions were defined based on country-specific CVD mortality rates. Models were recalibrated to each region using region-specific estimated CVD incidence rates and risk factor distributions. For external validation, we analysed data from 6 additional study populations {338 615 individuals, 33 219 CVD validation cohorts, C-indices ranged between 0.63 [95% confidence interval (CI) 0.61–0.65] and 0.67 (0.64–0.69)}. Regional calibration of expected-vs.-observed risks was satisfactory. For given risk factor profiles, there was substantial variation across the four risk regions in the estimated 10-year CVD event risk.

Conclusions 

The competing risk-adjusted SCORE2-OP model was derived, recalibrated, and externally validated to estimate 5- and 10-year CVD risk in older adults (aged 70 years or older) in four geographical risk regions. These models can be used for communicating the risk of CVD and potential benefit from risk factor treatment and may facilitate shared decision-making between clinicians and patients in CVD risk management in older persons.
Combined gene therapy via VEGF and mini-dystrophin synergistically improves pathologies in temporalis muscle of dystrophin/utrophin double knockout mice
Authors: Xin Can , Chu Xiangyu , Wei Wenzhong , Kuang Biao , Wang Yiqing , Tang Ying , Chen Jincao , You Hongbo , Li Chengwen , Wang Bing
Published: May 2021

Duchenne muscular dystrophy (DMD) is a severe X-linked inherited muscular disorder characterized by the loss of dystrophin. We have previously shown that monogene therapy using the mini-dystrophin gene improves muscle function in DMD. However, chronic inflammation plays an important role in progressive muscle degeneration in DMD as well. Vascular endothelial growth factor (VEGF) has been used to enhance muscle vasculature, reduce local inflammation and improve DMD muscle function. Temporalis muscles are the key skeletal muscles for mastication and loss of their function negatively affects DMD patient quality of life by reducing nutritional intake, but little is known about the pathology and treatment of the temporalis muscle in DMD. In this work, we tested the hypothesis that the combined delivery of the human mini-dystrophin and human VEGF genes to the temporalis muscles using separate recombinant adeno-associated viral (rAAV) vectors will synergistically improve muscle function and pathology in adult male dystrophin/utrophin double-knockout (mdx/utrn+/−) mice. The experimental mice were divided into four groups including: dystrophin + VEGF combined, dystrophin only, VEGF only and PBS control. After 2 months, gene expression and histological analysis of the temporalis muscles showed a synergistic improvement in temporalis muscle pathology and function coincident with increased restoration of dystrophin-associated protein complexes and nNOS in the dystrophin + VEGF combined group. We also observed significantly reduced inflammatory cell infiltration, central nucleation, and fibrosis in the dystrophin + VEGF combined group. We have demonstrated the efficacy of combined rAAV-mediated dystrophin and VEGF treatment of temporalis muscles in a DMD mouse model.
Norwood-I in a hypoplastic left heart variant and right aortic arch
Authors: Amodeo Antonio , Schweiger Martin , Erdil Tugba , Hübler Michael
Published: May 2021

Even though preoperative diagnostics have improved significantly, intraoperative surprises may still occur especially in the case of complex congenital heart disease. An instance of such a complex congenital heart disease is a hypoplastic left heart syndrome with a right-sided aortic arch. In this case report, we present 1 patient with such a complex and unexpected anatomy, as well as a possible way to overcome the obstacles.
Persisting Salivary IgG Against SARS-CoV-2 at 9 Months After Mild COVID-19: A Complementary Approach to Population Surveys
Authors: Alkharaan Hassan , Bayati Shaghayegh , Hellström Cecilia , Aleman Soo , Olsson Annika , Lindahl Karin , Bogdanovic Gordana , Healy Katie , Tsilingaridis Georgios , De Palma Patricia , Hober Sophia , Månberg Anna , Nilsson Peter , Pin Elisa , Sällberg Chen Margaret
Published: May 2021

Background

Declining humoral immunity in coronavirus disease 2019 (COVID-19) patients and possible reinfection have raised concern. Mucosal immunity, particularly salivary antibodies, may be short lived although long-term studies are lacking.

Methods

Using a multiplex bead-based array platform, we investigated antibodies specific to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins in 256 saliva samples from convalescent patients 1–9 months after symptomatic COVID-19 (n = 74, cohort 1), undiagnosed individuals with self-reported questionnaires (n = 147, cohort 2), and individuals sampled prepandemic (n = 35, cohort 3).

Results

Salivary IgG antibody responses in cohort 1 (mainly mild COVID-19) were detectable up to 9 months postrecovery, with high correlations between spike and nucleocapsid specificity. At 9 months, IgG remained in blood and saliva in most patients. Salivary IgA was rarely detected at this time point. In cohort 2, salivary IgG and IgA responses were significantly associated with recent history of COVID-19–like symptoms. Salivary IgG tolerated temperature and detergent pretreatments.

Conclusions

Unlike SARS-CoV-2 salivary IgA that appeared short lived, specific saliva IgG appeared stable even after mild COVID-19, as for blood serology. This noninvasive saliva-based SARS-CoV-2 antibody test with home self-collection may be a complementary alternative to conventional blood serology.
Gateway reflexes, neuronal circuits that regulate the autoreactive T cells in organs having blood barriers
Authors: Uchida Mona , Yamamoto Reiji , Matsuyama Shiina , Murakami Kaoru , Hasebe Rie , Hojyo Shintaro , Tanaka Yuki , Murakami Masaaki
Published: May 2021

Gateway reflexes are neural circuits that maintain homeostasis of the immune system. They form gateways for autoreactive T cells to infiltrate the central nervous system in a noradrenaline-dependent manner despite the blood–brain barrier. This mechanism is critical not only for maintaining organ homeostasis but also for inflammatory disease development. Gateway reflexes can be regulated by environmental or artificial stimuli including electrical stimulation, suggesting that the infiltration of immune cells can be controlled by bioelectronic medicine. In this review, we describe the discovery of gateway reflexes and their future directions with special focus on bioelectronic medicine.