bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the axial stress of angle steel components of transmission tower
Authors: Yu Xinmin , Fu Benzhao , Xie Ming
Published: July 2020

Taking the common specifications of the transmission tower as equal angle steel as the research object, for the angle steel of different specifications, based on the theory of equal strength, the critical slenderness ratio and the critical calculated length of each angle steel under the arrangement of parallel axis and minimum axis and Q345 and Q420 materials The critical slenderness ratio and critical calculated length of each angle steel under the minimum axis arrangement, and by simplifying the economic index, comparing the stability coefficient and stable bearing capacity of the angle steel under the same conditions, analyzing the economics of the angle steel, and finally proposing In the design of the line pole tower, the method of selecting angle steel reasonably.
Study on calculation method of auxiliary materials for transmission tower
Authors: Fu Benzhao , Yu Xinmin , Xie Ming
Published: July 2020

Comparing the provisions of domestic and foreign codes on the supporting force of auxiliary materials, the major domestic design institutes used design software, combined with the test results of the 220kV double-circuit linear tower (SZ801) true-type test, and concluded that compared with “Standard for design of steel structures”, “Design of latticed steel transmission structures “and the test results, the value of the internal force of the auxiliary materials of “Technical code for the design of tower and pole structures of overhead transmission line “is conservative. The value of the internal force of auxiliary materials supported by “Industry standards” only considers the influence of the main and inclined materials, and does not consider the effect of different equal distribution methods on the value.
Mechanical analysis of ribbed floor using continuum model
Authors: Zhu Jiejiang , Zhou Bolun
Published: July 2020

An approximate method based on a continuum model is proposed for analysis of floor system. A continuum model equivalent to the original ribbed floor is derived and the theoretical analytical solution of the deflection and force of the floor system is calculated. The calculation of rectangular slab whose size is 8m and 6m is carried out in the paper. Finite element analysis program SAP2000 is used for structural calculation to verify the correctness of the sample. The continuum method can result in considerable simplicity in computation analysis and provide a basis for subsequent optimization design.
Seismic finite element analysis of tailings dam in high seismic intensity area
Authors: Zhao Chongxu , Yao Lunqiang , Hou Shichao , Zhu Yantao , Gu Hao , Li Bo
Published: July 2020

As an important facility for mine exploitation, the safety of tailings dam is very important in high seismic intensity area. In this paper, the seismic stability analysis of tailings dam located in high intensity area was carried out by taking the example of one tailings dam. Three-dimensional finite element model was established, and the calculation results were analyzed and compared under fixed boundary condition and viscous spring boundary condition. The results showed that, (1) Under the static condition, the deformation value is distributed in layers from top to bottom. (2) Under the seismic condition, it can be seen that the Z direction deformation is the largest, followed by the X direction, and the Y direction deformation is the smallest. (3) It is too conservative to evaluate the seismic stability of dam slope with the minimum safety coefficient, while it is more practical to use the minimum average safety factor as the evaluation index.
The Status of Foreign Advanced Pasture Water Supply Technology
Authors: Wang Xingtian , Zhu Junfeng , Cao Liang , Wang Shifeng
Published: July 2020

Pasture water supply is of great significance for rational management of grassland, maintaining grassland ecological balance and promoting the development of animal husbandry. The investigation of international advanced pasture water supply technology has important reference value for the development of science, technology and economy in domestic pasture area. The advanced pasture water supply technology in the United States, Canada and Holland was summarized and analyzed through the literature retrieval with database. And the current situation of water supply technology in typical pastures of China was investigated and summarized through the field investigation of the Inner Mongolia pasture and the visit of the local herdsmen. The foreign pasture advanced water supply technology of Fresh Water Mill, batteryless photovoltaic water supply system, stand-alone mixed energy supply system, wireless data collection system of remote water supply system, automatic constant temperature water supply system and automatic water supply control system for pasture are put forward in accordance with the characteristics of pasture in China.
Impact of Slightly-Curved Riparian Vegetation Distribution on Hyporheic Lateral Exchange solute migration
Authors: Yu Genting , Zhou Xinyan , You Aiju , Xu Haibo , Hu Keke , Hu Lin
Published: July 2020

Riparian hyporheic exchange has a very important role in blocking and reducing pollution. In order to quantitatively grasp the self-purification ability of the river and predict the change of water quality, it is necessary to have a good understanding of the process that drives river water into the hyporheic layer. In this paper, the effects of slightly-curved riparian and vegetation density on the hyporheic lateral exchange of solute migration were studied in depth through model tests. The results show that: (1) The vegetation spacing d has a significant effect on the hyporheic lateral exchange. As the lateral spacing of vegetation decreases, the rate of hyporheic lateral exchange increases. (2) The amplitude a has a significant effect on the hyporheic lateral exchange. As the amplitude a increases, the faster the hyporheic lateral exchange rate on convex surface, and the larger the feather forward area of solute migration. However, due to the expansion of the volume of the retention area on the concave surface, it has a suppressive effect on the disturbance pressure and delays the solute transport. (3) There is a certain asymptotic limit for the increase of the hyporheic lateral exchange width, when the ratio of the underground pore water concentration C′ to the surface circulating water concentration C0′in the riparian zone is equal to 0.50, the solute transport width can be approximated as a suitable width for the hyporheic lateral exchange. The results are expected to provide a certain reference for the theoretical research of riparian hyporheic exchange.
On Building a Green Credit System for Marine Environment Protection
Authors: Wei Yang , Hao Kong
Published: July 2020

On August 31, 2016, the People’s Bank of China (PBC), along with six other government agencies, issued the Guidelines for Establishing the Green Financial System, introducing a series of measures to support and encourage green investment and financing. On September 2, the China Banking Regulatory Commission (CBRC) proposed a framework for building a green credit system and comprehensive evaluation of green credit, which lays out the development direction for green lending. Learning from international and domestic research and practical experiences, this paper tries to develop a green credit system for marine environmental protection. Based on the current green credit theory and policy trend, this thesis sets the operating mechanism for green credit, which can enforce contact and cooperation between marine environmental protection departments and financial regulators. All of these can promote enterprises and individual polluters to pay attention to marine environment, strengthen pollution control and maintain ecosystem healthy.
Seismic landslide susceptibility assessment based on ADASYN-LDA model
Authors: Zhang Shuhao , Yu Peiqiao
Published: July 2020

Seismic landslide susceptibility (SLS) assessment can be used to estimate the susceptibility of landslides induced by an earthquake, which has great significance for emergency measure making and land use planning to mitigate the landslide hazard and risk. At present, one of the key problems in SLS evaluation is that the sample is extremely unbalanced, that is, the number of landslide units is usually far less than that of non-landslide units, which easily leads to poor prediction performance of SLS model. In addition, when using high-resolution mapping units, the sample size greatly increases, and thus the training time cost is considerable especially for complicated nonlinear artificial intelligence such as the Support Vector Machine and the Neural Networks. In view of this, this paper proposes an SLS model (called ADASYN-LDA) combining ADASYN sample method and linear discriminant analysis (LDA), and evaluates it using 2014 Ludian earthquake event. The results show that the two ADASYN-LDA models are highly efficient in training, and have good prediction performance with the high AUC of 0.8737 and 0.8535 respectively, and with the balanced accuracy of 0.7950 and 0.6174 respectively. Compared with the traditional LDA model without ADASYN method, ADASYN-LDA model improves the results of the SLS assessment affected by the sample imbalance. The further evaluation is needed in other earthquake events, and the further improvement can be made with more landslide conditioning factors and seismic landslide data set.
Numerical investigation of bolt anchorage with tension force and shear force
Authors: Chen Yu , Li Yongde
Published: July 2020

The bolt anchorage with tension force and shear force are studied numerically by FLAC3D modelling. A tri-linear material model was utilized for the bolt steels in order to simulate the strain hardening behaviour of the materials. The numerical modelling show that different types of bolts have similar load capacities, while their deformation capacities are different. The numerical results match the laboratory test results. The different deformation capacities of rock bolts are attributed to their different bonding conditions and stretching lengths. The axial load in the rebar bolt reduces exponentially from the loading point close to the joint to the bolt end. The axial load in the D-Bolt has its maximum at the joint and reduces slowly as the distance from the joint increases.
Research on speed regulation system of water turbine generator unit based on PID neural network
Authors: Yu Ping , Yu Yue , Ren Zhiqiang , Wu Congbing , Xu Yubao
Published: July 2020

For the water turbine generator unit speed control system control error is large, long adjustment time, low control accuracy, poor stability and other problems, the PID neural network speed control strategy is proposed. First of all, the PID neural network (PIDNN) is used to design the speed control system of the turbine generator unit, and a complete model of the turbine generator unit speed control system is established. Secondly, using MATLAB for simulation, the step response of the water turbine generator unit speed control system is obtained. Finally, compared with the traditional PID controller, the PID neural network controller has obvious advantages in controlling error, adjusting time, over-tuning inhibition, etc., and has good stability.
Water Resources Carrying Capacity Assessment in Dali Prefecture Based on T-S Fuzzy Neural Network Model
Authors: Chen Jinming , Gu Shixiang , Chen Gang , Du Xuanxuan , Hong Jinshu
Published: July 2020

Water resources carrying capacity (WRCC) assessment is an effective way to evaluate the coordinated development of water resources, economic society and ecological environment, thus, it is significant to study WRCC to realize the harmony among water resources, economy and society in region. In this paper, an index system for evaluating WRCC, which represents the natural attributes and the managerial attributes of water resource, was constructed. Moreover, the T-S Fuzzy Neural Network Model was applied to evaluate WRCC of resource-oriented, management-oriented and comprehensive in Dali Prefecture, respectively. The results showed that evaluation results of WRCC of resource-oriented, management-oriented and comprehensive were different from each other obviously. Evaluation results of comprehensive WRCC accords with the fact. The WRCC in research region was averaged overall. WRCC in Heqing county, Eryuan county, Yangbi county, Dali city, Binchuan county, Xiangyun county and north of Midu county and Weishan county was already in a critical status, but that in the other area of Dali Prefecture was in non-overloading status.
Study on the Method of Solving the P-III Curve Fitted by Precipitation Frequency Based on Excel
Authors: Liu Hongliang , Li Shanhai , Qin Peng
Published: July 2020

The built-in function of Excel was used to calculate the precipitation frequency, the least square method was used to fit the appropriate line, the statistical parameters of hydrological variables were optimized, and the charting function was used to draw the precipitation frequency curve to meet the requirements of production practice.
Analysis on Mechanism to Improve the Recovery in Tight Oil Reservoirs by Imbibition
Authors: Chunming He , Jin Chen , Xiaochao Wang , Shuai Li , Ning Cheng , hui Zhang
Published: July 2020

In order to explore the mechanism to improve the recovery percent in tight oil reservoirs, the mechanisms and main controlling factors of improving the recovery percent by different production mechanisms are analyzed by combining spontaneous imbibition, core displacement experiment and nuclear magnetic resonance (NMR) test. It is shown by the study that the recovery percent can be improved from 20% to more than 40% by increasing the displacement differential pressure for tight rock samples. During differential pressure displacement, the reservoir fluid in large and medium pores is mostly produced. It is proven by the pressured imbibition experiment that in the process of soaking, the fluid exchange between fractures and matrix and between large and small pores can be realized to improve the recovery percent of fine pores, and the recovery percent (mainly of fine pores) can be improved by 7-10% through pressured imbibition displacement. Large contact area caused by the complex fractures formed by stimulated reservoir volume (SRV) fracturing is the basis to improve the recovery percent by imbibition, but the recovery percent of simple fractures is limited. The research results of this paper will provide guidance for the stimulation technology and fluid system optimization to improve the recovery percent of tight oil.
A New Probe into the Evaluation indicator for the Suitability of Recharge Engineering
Authors: Changbing Song , Xiangdong Song
Published: July 2020

Recharge measures can effectively eliminate the potential environmental risks caused by the loss of groundwater. It is a commonly used groundwater control measure and is widely implemented nationwide. However, at present, there is no clear judgment method for whether certain projects are feasible to recharge. This article classifies and summarizes the evaluation indicators in terms of the necessity, feasibility and economy of recharging, and provides a basis for the decision of recharging projects.
Displacement analysis of open pipe piles sinking based on strain path method
Authors: Kaishun Zhang
Published: July 2020

The displacement field in the process of opening pipe piles sink has always been a hot issue in the study, especially in the area of pile, the soil body has produced a large strain, regardless of the large deformation effect of the soil, there will be a large calculation error. The strain path method can obtain the flow velocity of the soil because it does not rely on the constitutive relationship of the soil, which is a favorable theory for solving large strain problems. In this paper, the modified strain path method is used as the theoretical basis. The open pipe pile is equivalent to a closed pipe pile through the soil plug effect, and the sunk pile displacement of the open pipe pile is calculated to further reveal the soil plug effect and the soil squeeze effect of the open pipe pile mutual restraint and mutual influence, thus providing a theoretical basis for the pile displacement of open pipe piles.
Superposition Technology of Complex Giant Reinforced Concrete Beams
Authors: Cangjie He , Hu Huang , Lu Li , Jing Guo , Fengqi Gao
Published: July 2020

Superposition technology construction is widely used in Large-span structures, super high-rise structures and large drop concrete structures. Based on the construction process of reinforced concrete for deep foundation pit engineering in Changsha Ice and Snow World, Superposition technology and support design of large section concrete structures are discussed. ABAQUS finite element analysis was used to obtain the pouring process. It provides the technical foundation for the future design and construction of complex giant reinforced concrete structures.
The evolution of cracks in red clay under wet and dry cycles and its influence on shear strength
Authors: Chen Kai-Sheng
Published: July 2020

Using computer image processing technology and lots of triaxial experiments, the fracture evolution rules and shear strength indexes of red clay in the wet and dry cycles were analyzed, and the functional relationship between shear strength indexes of red clay and fracture density was established. The parameters in slope stability calculation were also discussed by the strength indexes reduction method. The results show that with the increase of the times of dry and wet cycles, the crack density gradually increases and eventually it remains stable. During the first two wet and dry cycles, the crack development of red clay was the most obvious. After the dry-wet cycle, the stress-strain curve of the red clay is weakly hardened and the failure mode is bulging. The shear strength of red clay is significantly reduced by the influence of dry wet cycle. After the first cycle, the attenuation of strength indexes is obvious, and the final strength indexes trend to be stable. The attenuation amplitude of the cohesive force is significantly larger than the internal friction angle. After the wet-dry cycle, the stable value of its cohesion becomes 54% ∼ 57% of the initial value, and the stable value of the internal friction angle becomes 45% ∼ 63% of the initial value, so it is recommended to use the value of the long-term strength index and it is more accurate to calculate the slope stability under dry and wet cycles. Under the action of dry and wet cycles, a quadratic polynomial can be used to fit the functional connection between the crack density of red clay and the index of shear strength.
Grouting reinforcement treatment method for super-shallow buried metro station crossing sand layer
Authors: Bing Zhang , Shijie Zhang
Published: July 2020

The quaternary water-rich sand layer is often traversed during the construction of metro tunnels, and is one of the main geological disaster sources that affect the safety of metro construction. The grouting method is the most commonly used method to control the geological hazards of the water-rich sand layer. Affected by the pore structure of the sand layer and the state of in-situ stress, this paper proposes a method of grouting reinforcement with mould bag piles for sand grouting. Progressive section grouting can successfully solve the problem of sand layer reinforcement. The results show that: (1) The mould bag pile reinforcement can effectively strengthen the sand layer and ensure that the sand layer within the slurry diffusion range can be effectively strengthened, and increase the grouting retention rate; (2) Progressive section grouting can achieve the effect of grouting reinforcement at different depths to ensure the effect of grouting. This method has been successfully applied in metro station, hoping to provide some reference for similar projects.
Bearing Performance Analysis of Anti-slip Connector
Authors: Fang Zhenggang , Dong Yuming , Qi Daokun , Zhao Weibo
Published: July 2020

The performance of anti-slip connector determines whether the mounted load can be reliably transmitted to the main body of transmission tower. In this paper, the specific design process for each part parameter of anti-slip connector is given, and the bearing performance of anti-slip connector is analysed by theoretical/finite element method. The results show that: The influence of the distance between rectangular steel pipes on the bearing capacity of anti-slip connector is related to the bolt grade. When the bolt grade is lower, the initial stiffness of anti-slip connector mainly depends on the rotational stiffness of two-plate connection. When the bolt grade is higher, the change of the distance between rectangular steel pipes causes the change of the linear stiffness of mounted iron bar, which leads to the obvious change of both initial stiffness and plastic bearing capacity of anti-slip connector. Meanwhile, the influence of bolt grade on the initial stiffness of anti-slip connector is also related to the distance between rectangular steel pipes. When the distance between rectangular steel pipes is smaller, the initial stiffness of anti-slip connector is greatly affected by the bolt grade. When the distance between rectangular steel pipes is larger, the initial stiffness of the anti-slip connector model is basically unchanged under the change of bolt grade. In practical engineering, when the mounted distance is limited, the corresponding bolt grade must be matched, so that the bearing capacity of anti-slip connector can be effectively performed.
Groundwater velocity determination by single-borehole dilution test
Authors: Zhang Yuping , Wang Hongbo , Zhang Xike , Dong Haizhou , Mao Changping
Published: July 2020

The single-borehole dilution test involves the injection of a tracer into a borehole following by repeated water column profiling to monitor groundwater velocity within the vicinity of the borehole. Based on the concept that a tracer’s concentration decreases as a consequence of the groundwater dilution, the groundwater velocity can be determined by analysing the measured tracer concentration curves over time. The borehole dilution test allows the determination of both horizontal and vertical velocities in a single well. The presence of vertical flow in a borehole may greatly affect the evaluation of horizontal velocity since the decline of tracer concentration is caused by both horizontal and vertical flow simultaneously. Two approaches presented provide the estimation method of horizontal velocity without using packers to prevent vertical flow.
Finite element simulation of recycled large aggregate self-compacting concrete short columns with steel tubes
Authors: Wang Jianchao , Ma Guangzhuo , Yang Wentao
Published: July 2020

In order to study the mechanical properties of recycled large aggregate self-compacting concrete filled steel tube(RLA-SCCFST) and promote the research and application of the structure, the mechanical properties of nine groups of RLA-SCCFST short columns under axial compression were studied by ABAQUS simulation. Comparing the results of finite element simulation with the test results, it is found that: 1. The simulation results of the load-vertical strain curve are in good agreement with the test results, and the maximum error of the ultimate bearing capacity measured by the simulation and the test is within 3%; 2. The ultimate bearing capacity and ductility of RLA-SCCFST specimen increase with the increase of steel pipe wall thickness, recycled large aggregate strength and self-compacting concrete strength, and the ultimate bearing capacity of specimen decreases with the increase of recycled large aggregate content.
Human mobility in interest space and interactive random walk
Authors: Zeng Fanqi , Gong Li , Liu Jing , Zhang Jiang , Chen Qinghua , Xin Ruyue
Published: July 2020

Compared with the well-studied topic of human mobility in real geographic space, only a few studies focus on human mobility in virtual space, such as interests, knowledge, ideas, and so on. However, it relates to the issues like public opinion management, knowledge diffusion, and innovation. In this paper, we assume that the interests of a group of online users can span an Euclidean space which is called interest space, and the transfers of user interests can be modelled as Lévy Flight in the interest space. Considering the interaction between users, we assume that the random walkers are not independent but interacting with each other indirectly via the digital resources in the interest space. The proposed model in this paper successfully reproduced a set of scaling laws for describing the growth of attention flow networks of online communities, and obtaining similar ranges of users’ scaling exponents with empirical data. Further, we inferred parameters for describing the individual behaviours of the users according to the scaling laws of empirical attention flow network. Our model can not only provide theoretical understanding of human online behaviours but also has broad potential applications such as dissemination and public opinion management, online recommendation, etc.
Neurodiversity at work: a biopsychosocial model and the impact on working adults
Authors: Doyle Nancy
Published: July 2020

Introduction

The term neurodiversity is defined and discussed from the perspectives of neuroscience, psychology and campaigners with lived experience, illustrating the development of aetiological theories for included neurodevelopmental disorders. The emerging discourse is discussed with relevance to adults, social inclusion, occupational performance and the legislative obligations of organizations.

Sources of data

Literature is reviewed from medicine, psychiatry, psychology, sociology and popular press. No new data are presented in this article.

Areas of agreement

There is consensus regarding some neurodevelopmental conditions being classed as neurominorities, with a ‘spiky profile’ of executive functions difficulties juxtaposed against neurocognitive strengths as a defining characteristic.

Areas of controversy

The developing nomenclature is debated and the application of disability status versus naturally occurring difference. Diagnosis and legal protections vary geographically, resulting in heretofore unclear guidance for practitioners and employers.

Growing points

The evolutionary critique of the medical model, recognizing and updating clinical approaches considering the emerging consensus and paradigmatic shift.

Areas timely for developing research

It is recommended that research addresses more functional, occupational concerns and includes the experiences of stakeholders in research development, moving away from diagnosis and deficit towards multi-disciplinary collaboration within a biopsychosocial model.
Life-Long Neural Stem Cells Are Fate-Specified at an Early Developmental Stage
Authors: Tanaka Aoi , Ishida Shohei , Fuchigami Takahiro , Hayashi Yoshitaka , Kuroda Anri , Ikenaka Kazuhiro , Fukazawa Yugo , Hitoshi Seiji
Published: July 2020

The origin and life-long fate of quiescent neural stem cells (NSCs) in the adult mammalian brain remain largely unknown. A few neural precursor cells in the embryonic brain elongate their cell cycle time and subsequently become quiescent postnatally, suggesting the possibility that life-long NSCs are selected at an early embryonic stage. Here, we utilized a GFP-expressing lentivirus to investigate the fate of progeny from individual lentivirus-infected NSCs by identifying the lentiviral integration site. Our data suggest that NSCs become specified to two or more lineages prior to embryonic day 13.5 in mice: one NSC lineage produces cells only for the cortex and another provides neurons to the olfactory bulb. The majority of neurosphere-forming NSCs in the adult brain are relatively dormant and generate very few cells, if any, in the olfactory bulb or cortex, and this NSC population could serve as a reservoir that is occasionally reactivated later in life.
Risk Factors for Healthcare Personnel Infection With Endemic Coronaviruses (HKU1, OC43, NL63, 229E): Results from the Respiratory Protection Effectiveness Clinical Trial (ResPECT)
Authors: Cummings Derek A T , Radonovich Lewis J , Gorse Geoffrey J , Gaydos Charlotte A , Bessesen Mary T , Brown Alexandria C , Gibert Cynthia L , Hitchings Matthew D T , Lessler Justin , Nyquist Ann-Christine , Rattigan Susan M , Rodriguez-Barradas Maria C , Price Connie Savor , Reich Nicholas G , Simberkoff Michael S , Perl Trish M
Published: July 2020

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents a large risk to healthcare personnel (HCP). Quantifying the risk of coronavirus infection associated with workplace activities is an urgent need.

Methods

We assessed the association of worker characteristics, occupational roles and behaviors, and participation in procedures with the risk of endemic coronavirus infection among HCP who participated in the Respiratory Protection Effectiveness Clinical Trial (ResPECT), a cluster randomized trial to assess personal protective equipment to prevent respiratory infections and illness conducted from 2011 to 2016.

Results

Among 4689 HCP seasons, we detected coronavirus infection in 387 (8%). HCP who participated in an aerosol-generating procedure (AGP) at least once during the viral respiratory season were 105% (95% confidence interval, 21%–240%) more likely to be diagnosed with a laboratory-confirmed coronavirus infection. Younger individuals, those who saw pediatric patients, and those with household members <5 years of age were at increased risk of coronavirus infection.

Conclusions

Our analysis suggests that the risk of HCP becoming infected with an endemic coronavirus increases approximately 2-fold with exposures to AGPs. Our findings may be relevant to the coronavirus disease 2019 (COVID-19) pandemic; however, SARS-CoV-2, the virus that causes COVID-19, may differ from endemic coronaviruses in important ways.

Clinical Trials Registration

NCT01249625.
Safety, Pharmacokinetics, and Causal Prophylactic Efficacy of KAF156 in a Plasmodium falciparum Human Infection Study
Authors: Kublin James G , Murphy Sean C , Maenza Janine , Seilie Annette M , Jain Jay Prakash , Berger David , Spera Danielle , Zhao Rong , Soon Rachel L , Czartoski Julie L , Potochnic Meredith A , Duke Elizabeth , Chang Ming , Vaughan Ashley , Kappe Stefan H I , Leong F Joel , Pertel Peter , Prince William T ,   KAF156 Study Team
Published: July 2020

Background

KAF156 is a novel antimalarial drug that is active against both liver- and blood-stage Plasmodium parasites, including drug-resistant strains. Here, we investigated the causal prophylactic efficacy of KAF156 in a controlled human malaria infection (CHMI) model.

Methods

In part 1, healthy, malaria-naive participants received 800 mg KAF156 or placebo 3 hours before CHMI with P. falciparum–infected mosquitoes. In part 2, KAF156 was administered as single doses of 800, 300, 100, 50, or 20 mg 21 hours post-CHMI. All participants received atovaquone/proguanil treatment if blood-stage infection was detected or on day 29. For each cohort, 7–14 subjects were enrolled to KAF156 treatment and up to 4 subjects to placebo.

Results

KAF156 at all dose levels was safe and well tolerated. Two serious adverse events were reported—both resolved without sequelae and neither was considered related to KAF156. In part 1, all participants treated with KAF156 and none of those randomized to placebo were protected against malaria infection. In part 2, all participants treated with placebo or 20 mg KAF156 developed malaria infection. In contrast, 50 mg KAF156 protected 3 of 14 participants from infection, and doses of 800, 300, and 100 mg KAF156 protected all subjects against infection. An exposure–response analysis suggested that a 24-hour postdose concentration of KAF156 of 21.5 ng/mL (90% confidence interval, 17.66–25.32 ng/mL) would ensure a 95% chance of protection from malaria parasite infection.

Conclusions

KAF156 was safe and well tolerated and demonstrated high levels of pre- and post-CHMI protective efficacy.

Clinical Trials Registration

NCT04072302
Multitemporal analysis of ambient noise polarization to characterize site response in the town of Amatrice, shattered by the 2016 central Italy earthquake
Authors: Del Gaudio Vincenzo , Wasowski Janusz , Pierri Pierpaolo , Moretti Antonio , Ferrini Gianluca
Published: July 2020

The Mw 6.0 earthquake that hit central Italy on 2016 August 24 caused an abnormally high level of destruction in the town of Amatrice. In order to clarify the role of site response in causing such a disaster, a series of ambient noise recordings acquired in the aftermath of the event are analysed here to identify site resonance properties from the ratios H/V between horizontal and vertical amplitudes of ground motion. Although the noise data acquisition was limited by the emergency management activities, the use of a new analysis technique, which isolates the contribution of Rayleigh waves to the noise wavefield and averages instantaneous estimates of H/V ratios, provided more stable results compared to the standard Nakamura's technique based on mean spectral ratios. The results demonstrated the occurrence of significant resonance phenomena, but without an obvious correlation with the spatial distribution of damage severity. It is apparent that the damage severity was also influenced by some additional local factors related to building vulnerability. Moreover, the time-series analysis revealed seasonal variations in the Rayleigh wave ellipticity curves likely related to the water content changes in the surface deposits and their influence on the Poisson coefficient. Finally, the new method proved capable of recognizing time-varying directions of Rayleigh wave propagation. This capability could be exploited to support other passive seismic methods (e.g. ReMi), whose results’ reliability is limited by the lack of control on wave direction origin.
Outcome of modified réparation à l’ètage ventriculaire (REV) based on anatomical characteristics for the anomalous ventriculoarterial connection with ventricular septal defect and left ventricular outflow tract obstruction
Authors: An Kang , Hu Shengshou , Li Shoujun , Yan Jun , Wang Xu , Hua Zhongdong
Published: July 2020

OBJECTIVES

The present study evaluated the results of the modified réparation à l’étage ventriculaire (REV) based on the individual anatomical and pathological findings of the patients with an anomalous ventriculo-arterial connection with ventricular septal defect (VSD) and left ventricular outflow tract obstruction.

METHODS

We reviewed a series of 24 patients who underwent modified REV between 2005 and 2019. Surgical indications included ventricles and atrioventricular valves suitable for biventricular repair, severe left ventricular outflow tract obstruction (peak gradient >30 mmHg), unrestrictive subaortic VSD and coronary arteries not suitable for reimplantation.

RESULTS

The mean follow-up time was 7.0 ± 4.2 years (range 0.5–14.1 years). Kaplan–Meier analyses showed that overall survival was 100% and freedom from any reoperation was 93.3% ± 6.4%. Longitudinal analyses of the available postoperative echocardiographic data showed that the left ventricular outflow tract peak gradient was less than 10 mmHg in all patients (15/15) and the left ventricular ejection fraction was more than 50% in 93.3% of patients (14/15). The right ventricular outflow tract peak gradient was less than 40 mmHg in 73.3% of patients (11/15).

CONCLUSIONS

The REV remains an option for selected patients despite the increasing use in recent years of the Nikaidoh procedure and its modifications. The surgical strategy needs to be determined by the specific anatomical and pathological findings of the patient. The modified REV had excellent long-term survival and freedom from reoperation for the treatment of anomalous ventriculo-arterial connection with VSD and left ventricular outflow tract obstruction. The long-term performance of the reconstructed left ventricular outflow tract and right ventricular outflow tract is satisfactory.
The Impact of Immunosuppression on Chronic Kidney Disease in People Living With Human Immunodeficiency Virus: The D:A:D Study
Authors: Ryom Lene , Lundgren Jens D , Reiss Peter , Ross Mike , Kirk Ole , Fux Christophe A , Morlat Phillipe , Fontas Eric , Smith Colette , De Wit Stephane , d’Arminio Monforte Antonella , El Sadr Wafaa , Hatleberg Camilla , Phillips Andrew , Sabin Caroline , Law Matthew , Mocroft Amanda
Published: July 2020

Background

Relations between different measures of human immunodeficiency virus–related immunosuppression and chronic kidney disease (CKD) remain unknown.

Methods

Immunosuppression measures included baseline, current, time-lagged and nadir CD4, years and percentage of follow-up (%FU) with CD4 ≤200 cells/μL, and CD4 recovery. CKD was defined as confirmed estimated glomerular filtration rate <60 mL/minute/1.73 m2.

Results

Of 33 791 persons, 2226 developed CKD. Univariably, all immunosuppression measures predicted CKD. Multivariably, the strongest predictor was %FU CD4 ≤200 cells/μL (0 vs >25%; incidence rate ratio [IRR], 0.77 [95% confidence interval [CI], .68–.88]), with highest effect in those at low D:A:D CKD risk (IRR, 0.45 [95% CI, .24–.80]) vs 0.80 [95% CI, .70–.93]).

Conclusions

Longer immunosuppression duration most strongly predicts CKD and affects persons at low CKD risk more.
Role of Base Excision Repair inListeria monocytogenesDNA Stress Survival During Infections
Authors: Zhang Juan , Wang Shuyi , Abee Tjakko , van der Veen Stijn
Published: July 2020

Background

Base excision repair (BER), consisting mostly of lesion-specific DNA glycosylases and apurinic/apyrimidinic (AP) endonucleases, is one of the most important DNA repair mechanisms for repair of single nucleobase lesions generated by reactive oxygen and nitrogen species as part of an immune response against bacterial infections. However, few studies have addressed the contribution of BER to bacterial virulence and Listeria monocytogenes BER has thus far remained completely uncharacterized.

Methods

Analysis of the L. monocytogenes EGDe genome identified 7 DNA glycosylases (MutM, MutY, Nth, Tag, Mpg, Ung, and Ung2) and 2 apurinic/apyrimidinic endonucleases (Xth and Nfo) as part of BER. Markerless in-frame deletion mutants were generated for all 9 genes, and mutants were tested for DNA damage survival, mutagenesis, and the ability to colonize a mouse model of infection.

Results

Distinct lesion-specific phenotypes were identified for all deletion mutants. Importantly, the Δnth, ΔmutY, and Δnfo mutants were significantly attenuated for virulence in the mouse model and showed much lower colonization of the liver and spleen or were unable to compete with the wild-type strain during in vivo competition assays.

Conclusions

Our results highlight the importance of BER for L. monocytogenes virulence and survival of DNA-damaging insults during host colonization.
The impact of the COVID-19 pandemic on antimicrobial resistance: a debate
Authors: van Duin David , Barlow Gavin , Nathwani Dilip
Published: July 2020

The coronavirus disease 2019 (COVID-19) pandemic is having an enormous impact on public health. Infection with SARS-CoV-2 has become a leading cause of morbidity and mortality in many regions around the world. As many COVID-19 patients are treated with antibiotics, there is concern regarding an associated rise in rates of antimicrobial resistance (AMR). On the other hand, social distancing, isolation and reduced travel may result in decreased spread of AMR. In this issue of JAC-Antimicrobial Resistance, we present a PRO/CON debate on the question of the potential impact of COVID-19 on AMR rates.
Reflector Localization of Breast Lesions and Parameters Associated with Positive Surgical Margins in Women Undergoing Breast Conservation Surgery
Authors: Kuzmiak Cherie M , Kim Suk Jung , Lee Sheila S , Jordan Sheryl G , Gallagher Kristalyn K , Ollila David W , Zeng Donglin
Published: July 2020

Objective

To evaluate our experience with reflector localization of breast lesions and parameters influencing surgical margins in patients with a malignant diagnosis.

Methods

A retrospective institution review board–approved review of our institutional database was performed for breast lesions preoperatively localized from September 1, 2016, through December 31, 2017. Wire localizations were excluded. From electronic medical records and imaging, the following data was recorded: breast density, lesion type and size, reflector placement modality and number placed, reflector distance from lesion and skin, excision of lesion and reflector, tissue volume, margin status, and final pathology. Statistical analysis was performed with a Fisher’s exact test, Mann-Whitney test, and logistic regression. P < 0.05 was significant.

Results

A total of 111 reflectors were deployed in the breasts of 103 women with 109 breast lesions. Ninety (81.1%) reflectors were placed under mammographic guidance and 21 (18.9%) under US. The lesions consisted of 68 (62.4%) masses, 17 (15.6%) calcifications, 2 (1.8%) architectural distortions, and 22 (20.2%) biopsy markers. Fourteen (21.2%) of 66 cases with a preoperative malignant diagnosis had a positive surgical margin. Final pathology, including 6 lesions upgraded to malignancy on excision, demonstrated 72 (66.0%) malignant, 22 (20.2%) high-risk, and 15 (13.8%) benign lesions. Univariate and multivariate analysis revealed no statistically significant parameters (lesion type or size, placement modality, reflector distance to skin or lesion, specimen radiography or pathology) were associated with a positive surgical margin.

Conclusion

Reflector localization is an alternative to wire localization of breast lesions. There were no lesion-specific or technical parameters affecting positive surgical margins.
Conjuring the Criminal State: The “State-Idea” in Post-Conflict Reconstruction and International Statebuilding
Authors: Schwartz Rachel A
Published: July 2020

A central challenge of post-conflict recovery is the reconstruction of state institutions, which often emerge from war destroyed or otherwise unable to carry out core administrative activities. But scholarship on international peacebuilding and post-conflict politics tends to focus narrowly on the functional aspects of the state, the state-system, to the neglect of another critical dimension: the state-idea, or its symbolic and normative authority. How do internationally backed institution-building efforts shape the ideational foundations of the state following conflict? Drawing on original interviews and archival research from postwar Guatemala, this article illustrates how, paradoxically, postwar peacebuilding and rule of law initiatives that sought to strengthen the capacity of state institutions simultaneously contributed to the discursive construction of the state as a criminal organization. Specifically, the United Nations’ International Commission against Impunity in Guatemala (CICIG), in seeking to combat state-based criminal structures and bolster institutions, transformed long-held conceptions of Guatemala's “weak” or “failed” state into an alternative vision of the state as a powerful complex of clandestine, predatory networks, and practices. In conjuring the state as a criminal organization that appropriates the formal organs of political power for illicit ends, this international statebuilding initiative generated a coherent and durable state-idea that belies key advances in institutional capacity and the rule of law. Overall, this article contributes to growing debates about the unintended, deleterious effects of international statebuilding efforts by demonstrating how distinct ideas of state power come to fill the void between state capacity and legitimacy.
Single Embryo Transfer Versus Double Embryo Transfer: A Cost-Effectiveness Analysis in a Non-IVF Insurance Mandated System
Authors: Sitler Collin , Lustik Michael , Levy Gary , Pier Bruce
Published: July 2020

Introduction

Because of increased morbidity seen in multiple gestations, the American Society of Reproductive Medicine recommends transfer of blastocysts one at a time for most patients. While cost-effectiveness models have compared single embryo transfer (SET) versus double embryo transfer (DET), few incorporate maternal and neonatal morbidity, and none have been performed in U.S. Military facilities. The purpose of this study was to determine the cost effectiveness of sequential SET versus DET in a U.S. Military treatment facility.

Materials and Methods

A cost-effectiveness model was created based on 250 patients between the ages of 20–44 who previously underwent in vitro fertilization (IVF) at our facility. The model consisted of patients pursuing either SET or DET with two total embryos. Cycle outcomes were determined using the published SARTCORS success calculator. Neonatal and obstetrical outcomes were simulated based on singleton and twin IVF pregnancies. Neonatal and obstetrical cost estimates were based on internal data as well.

Results

If 250 model patients pursue SET, 140 live births would occur, with total cost of $5.7 million, and cost per delivery of $40,500. If the model patients pursued DET, 117 live births would occur, with total cost of $9.2 million and a cost per delivery of $77.700. DET would lead to more total infants (207 vs. 143 in SET cohort). Personal costs are higher in SET versus DET cohorts ($23,036 vs. $20,535).

Conclusions

SET in a system with no infertility coverage saves approximately $3.5 million per 250 patients. Higher personal costs as seen with SET may incentivize patients to seek DET. The total savings should encourage alteration to practice patterns with the U.S Military Healthcare System.
Start the Right Way: A Foundation for Improving Connection to Service and People in Medical Education
Authors: Nevo Ofir Noah , Lambert Laura
Published: July 2020

Bottom Line Up Front: In this perspective essay, ENS Ofir Nevo and Dr Laura Lambert briefly discuss the concept of an outward mindset and how they have applied it in the context of medical education. ENS Nevo shares his story of deciding to attend medical school at the Uniformed Services University, as part of his desire and commitment to serve others. Early on, the requirements of medical school created intense demands that began to disconnect him from the commitment and connection that first drew him to a medical career. ENS Nevo describes how an awareness of the choice of mindset helped him address these challenges and stay better connected to his purpose and calling. A case analysis by Dr Lambert further explores how the awareness and practice of an outward mindset may help students, residents, and attendings see how they can improve their own well-being and connection to the people that brought them to medicine in the first place. Their experiences demonstrate how outward mindset principles can be a valuable tool for empowering students and physicians with a perspective that invites new solutions for the challenges of life and work.