bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards applicability of wavelet-based cross-correlation in locating leaks in steel water supply pipes
Authors: Faerman V , Sharkova S , Avramchuk V , Shkunenko V
Published: June 2022

The paper discussed the application of wavelet-based cross-correlation analysis to the processing of the leak noise signals acquired in the field. Nine recordings produced with the commercial leak noise correlator are considered in this study. All the cases are considered as classified as challenging for signal interpretation. For most of the cases, the basic correlation technique proved to be insufficient to measure the time lag with the required confidence. We implemented a wavelet cross-correlation algorithm for time lag estimation. At least in five cases out of nine, it managed to estimate time lag accurately. In three of the remaining cases, it failed. Unfortunately, due to a lack of information on field studies when records were produced, we are not able to investigate the reason of failures. We concluded that the proposed solution is practical and can be implemented in the software of leak noise correlators.
On ensuring dynamic voltage stability of critical loads in the electric power systems of industrial facilities
Authors: Suslov K V , Ilyushin P V , Kulikov A L
Published: June 2022

Voltage sags and interruptions in the electric power systems (internal grids) of industrial facilities are caused by various short circuits, including those that occur in external grids. If the depth and duration of such sags and interruptions exceed the rated limits for critical loads, they cause continuous processes to shut down, which produces defective products and entails substantial losses. Russian standards and regulations do not set forth requirements with respect to voltage sags and interruptions, which means that industrial companies cannot sue grid operators for damages. This is why dynamic voltage stability of critical loads involved in continuous processes has to be addressed within the internal grid. They analyze the effectiveness of solutions designed for dynamic voltage stability of critical loads; these can be shared, used on a single site or designed to power secondary circuits. It shows that use of dynamic voltage restorers (DVR) and dynamic voltage sag correctors (DVSC) can be a cost- effective solution if the topology and specifications are configured appropriately. The paper presents general technical requirements for sag and interruption compensators, which are adjusted for cost-effectiveness. Case-specific feasibility testing should be based on daily readings of electrical parameters and electric power quality readings, calculated electromechanical transients, and a feasibility study. Use of DVRs at an industrial facility helped stabilize the voltage curve and reduce the span of irregular voltage fluctuations by a factor of 3, reduce the average voltage at the 6 kV busbars without compromising equipment performance, and improve the starting conditions for AM clusters and self-starting conditions for large AMs. Thus, lowering the elevated voltage at the 6 kV busbars helped cut electricity purchase costs. In most cases where accidents cause disturbances in the external 110 kV grid, DVRs coupled with the automatic voltage controls of power transformers were able to prevent process shutdowns, which constituted the key cost effect.
Overview of existing methods of asynchronous motor diagnostics
Authors: Konstantinova M V , Malozyomov B V , Alikhadzhiyev S KH
Published: June 2022

The paper provides a review, analysis and research of existing diagnostic methods such as a vibroacoustic method based on the analysis of damped oscillations arising from dynamic loads of the system in friction nodes, the thermal method based on the analysis of thermal fields created by the object under study and the acoustic emission method, which includes an assessment of acoustic emission occurring in metals and welded joints. The advantages and disadvantages are identified and the conditions and areas of use of these methods are described. The applicability of these methods to such an electromechanical system as an asynchronous motor is also described. Vibroacoustic diagnostics can be used to assess shaft fatigue and wear of rolling bearings; thermal diagnostics can be used to diagnose the operation of the cooling system and assess the degree of aging of the insulation of the windings; the acoustic emission method is applicable in cases where it is necessary to assess the progressive wear of the shaft and bearing assemblies, as well as fatigue of gear elements in the gearbox.
Universal prediction algorithm in maneuvering target tracking
Authors: Zemskov Y , Koptseva E , Pankratova A , Borodulina S , Kalinov S
Published: June 2022

The paper considers the methods to increase the accuracy of trajectory processing of the results of radar measurements in automated air traffic management systems (AATMS). The recursive filters traditionally used in the secondary processing path of radar information of modern AATMS systems are briefly considered: alpha-beta filter, linear and extended Kalman filters, multi-model filter. Along with multi-model Kalman filters it is proposed to use a universal filter based on the universal prediction theorem, the accuracy of which is asymptotically no worse than any other filter in the class of continuous functions. The algorithm for the operation of a universal alpha-beta filter was developed. As a result of modeling, it was obtained that the mean square of the tracking error of the trajectory of a maneuvering target for the universal filter during the change of the motion model turned out to be lower than for traditional filters.
On the choice of a failure criterion for pumping units based on the results of vibration spectra measurement
Authors: Suleymanov R N , Suleymanov S R
Published: June 2022

The paper presents the results of a study of the possibility of failure prediction (failure) of complex units (for example, pumping units) as a result of the impact of vibration forces. It is shown that the total energy (time integral of the vibration power) at resonance frequencies and in an infinite frequency strip under the condition of the experimental coefficient can be a criterion for the failure of both individual units and the unit as a whole. In this case, the predicted failure time is a function of the calculated measure of destruction” and the accumulated energy.
Neural network technologies for analysis and risk assessment in forecasting the market of industrial financial instruments
Authors: Dvoryatkina S , Golovin D
Published: June 2022

The issues of risk analysis and assessment in forecasting the dynamics of prices on the stock exchange and the OTC market have always been a difficult task for many researchers and analysts. Successful investment is largely determined by knowledge of the future situation in the financial market. The article deals with the issues of search and development of technical tools for risk analysis and assessment in forecasting the market of derivative financial instruments under conditions of uncertainty. A recurrent network with a long-term short-term memory cell LSTM, which is one of the most powerful prediction models, was chosen as the architecture of neural networks. The development of technical tools for solving this problem was carried out on the basis of the C# programming language. An additional TA-Lib library served as a mathematical base for technical analysis, from which 42 technical analysis indicators were used during the development process, and for working with the LSTM recurrent network, the library Keras.NET. The ability to efficiently link memory and input remote data using these network memory cells provides a dynamic understanding of the data structure over time. The estimates of the accuracy of the forecast for the cost indicators of a derivative financial instrument obtained as a result of computer experiments showed the high efficiency of the constructed neural network model.
Investigation of the application of a high-voltage liquid voltage divider on Multisim software (version 10.0) and SolidWorks
Authors: Denmukhammadiev A M , Begmatov M T , Pardaev A I , Valikhanova H
Published: June 2022

The considered model was investigated according to the main characteristics corresponding to the real process (even the geometrical dimensions and electrophysical parameters coincide). It is known that a prerequisite for physical modeling is a strict geometric similarity of the model and character, as well as the equality of the corresponding similarity criteria in them. The cheapest insulator in the power industry is air. The air environment plays an important role in the design of ball arresters used in pulsed technology. In this case, it is important to measure the high-voltage voltage and obtain the exact shape of the discharge current pulse on the oscillogram. For this purpose, in this work, liquid voltage dividers were studied and the corresponding electronic models were developed. The results obtained in the electronic model are unreliable without experimental verification. The measuring equipment during the experiment gave positive results, indicating the quality of measurements, the correctness of the process of electric pulse treatment of seeds.
Method for modeling the process of wear of gear teeth
Authors: Ishmuratov Kh , Hamroev R K , Kurbonov B B , Mirzaev N N
Published: June 2022

When modeling gears by means of roller analogues it is necessary to take into account that the degree of slippage is equal to zero in the meshing pole of the gears, in thecontact zone ofinitial circles of the gears. The greatest slippage occurs between the tooth head of the master gear and the tooth foot of the driven gear, and between the tooth head of the driven gear and the tooth foot of the driven gear. Thus, the simulation of the wear process of gear wheels with roller counterparts is achieved by ensuring equality of geometric and kinematic parameters (radii of contact point curvature, degree of relative slippage of the surfaces, friction paths) and contact pressure.
Modern problems of digitalization in energy
Authors: Kondratiev V V , Permyakova D N , Olentsevich V A
Published: June 2022

The formation of the technological progress of the Russian economy is inextricably linked with the development of the industry. And one of the key industries is energy. It is she who largely determines the socio-economic and industrial development of the country. Without a doubt, with digitization, business becomes more efficient and products become more accessible. At this stage, the digitalization of postal systems in the Russian Federation makes it possible to process more than a billion e-mail messages every day. This leads to an increase in the growth rate of labor productivity and a decrease in costs. Therefore, there is reason to say that the digitalization of the electric power industry will allow not only achieving similar results, but also surpassing them.
Risk-based approach towards energy production
Authors: Permyakova D N , Konyukhov V Yu , Kondratiev V V
Published: June 2022

In modern digitalization conditions, reducing operating costs in order to increase profits in the energy sector is one of the fundamental tools for the company's growth and planning the production sector for the long term. One of the most modern approaches to work is risk-based. The article discusses the main aspects of the formation of this approach, the probability and consequences of failure, as well as the methodology for calculating technical risk.
An experimental study on the anisotropic and intermittent behaviour of a turbulent flow over a rough bed
Authors: Coscarella F , Penna N , Servidio S , Gaudio R
Published: June 2022

The flow field in open channels can be classified into different zones according to the velocity distribution. To explore the anisotropic and intermittent behaviour in the turbulent flow layers, an experimental study was performed using Particle Image Velocimetry (PIV) measurements in a hydraulic flume with rough bed. Specifically, the analysis has been focused on the two-dimensional (2D) high-order structure functions applied to the velocity data. It is demonstrated that the system spans from large-scale anisotropy, which is induced by the main shear of the boundary layer, to small-scale isotropy. Moreover, it is shown that the intermittency is more pronounced in the near-bed layer, where the flow is more populated by coherent whirling structures. In essence, both anisotropy and intermittency are proved to be important phenomena for natural bed rivers, since they affect the turbulence transport characteristics of the flow.
Transport analysis of solid sediments in a ballast water flow
Authors: Amoresano A , Iodice P , Langella G , Mocerino L , Quaranta F
Published: June 2022

The ballast waters, necessary for the stabilization of the ships, move with it and are often discharged into marine environments sensitive to non-native organisms and transport polluting sediments capable of altering the balance of the local ecosystem. In this work, the transportability of particles smaller than 1 mm in size is studied by experimental analysis and the velocity field, generated by the flow, is detected by means of an image acquisition system. The work is developed with an experimental method using a variable flow rate hydraulic circuit equipped with a transparent duct capable of allowing optical access. The measurements of the motion of the particles, acquired by means of the fast photography system, along a section of the transparent duct are analyzed near the sedimentation area. By means of an image processing the frequency of the particles, crossing trough the reference section is detected. The data processing by FFT provides the average flow rate of the sediments and allows quantizing the particles transport according to the different hydrodynamic conditions imposed.
On the Wall Pressure Fluctuations induced by a Supersonic Jet over the Wing pressure side
Authors: Meloni S. , de Paola E. , Curcio L. , Camussi R.
Published: June 2022

Supersonic jet wing integrated configurations are expected to be relatively louder than subsonic installed configurations, increasing the wall pressure load transmitted inside the fuselage and stressing the wing/fuselage panels with very energetic and frequency localized supersonic effects. In this framework, a model-scale experimental investigation of an installed jet-wing configuration has been performed using a supersonic convergent-divergent nozzle interacting with a wing generated by a NACA4415 airfoil. The measurements have been carried out in the semi-anechoic chamber of the “G.Guj” Fluid Dynamic laboratory at the University Roma Tre. Wall pressure fluctuations are acquired at different axial locations in stream-wise and span-wise directions. Measurements are repeated for different wing radial positions and by varying the NPR between 2.2 and 2.6, thus exploring both over-expanded and under-expanded jet flow conditions. The flow features that characterize the different flow regimes were caught using the Background Oriented Schlieren (BOS) technique. Fluctuating pressure data, acquired with flush-mounted pressure transducers, were analysed in the frequency domain, considering a Fourier-based approach. A comparison of results obtained with an infinite flat plate has been used to highlight effects generated by the discontinuity related to the trailing edge.
Line Scanning with Gas-Coupled Laser Acoustic Detection
Authors: Gulino Michelangelo-Santo , Bruzzi Mara , Vangi Dario
Published: June 2022

The Gas-Coupled Laser Acoustic Detection (GCLAD) is an optical technique for ultrasonic detection based on the deviation that a laser beam sustains when travelling in a fluid that features refractive index fluctuations. If the laser beam is perpendicular to the wave propagation direction, the technique enables simultaneous detection of direct waves in mechanical components and eventual echoes from defects to be achieved.

The technique is applied to the inspection of elements predominantly extending in one/two dimensions as bars and axisymmetric pieces, exploiting a signal enhancement effect occurring in defects’ proximity. The phenomenon, namely constructive interference between wave crests of a direct Rayleigh ultrasound and those associated with reflections on a defect flank, is first illustrated numerically. The effect of parameters like the angle between wave propagation direction and source-receiver distance on the GCLAD sensitivity is then experimentally highlighted. The technique is finally implemented to B-scan a steel plate with 1 mm wide, 20 mm long, and 3 mm deep surface defects.

Since the GCLAD probe laser beam insists on an entire line, defects present on that line can be identified without moving the device along such direction. This reduces the monitoring time compared to techniques leveraging on traditional air-coupled transducers or more sophisticated methods (Scanning Laser Source).
Exploring Mechanical Properties of SiO2 Elastic Micro-Nano Ceramic Fibres Aerogels
Authors: Wang Yanbo
Published: June 2022

With the development of hypersonic vehicles and the military, SiO2 elastic nano-fibre ceramic aerogel becomes a preferred and potential material due to its ultralight, thermal superinsulation, and superelasticity properties. Compared with traditional ceramic materials which are brittle and easily degraded, SiO2 elastic nano-fibre aerogel shows up with its outstanding characteristics under extreme conditions. Facing a major demand in the national strategy of thermal insulation materials, this study will keep an eye on these growing and famous novel materials. Summarizing current studies and research at home and abroad. And explaining the evolution from traditional SiO2 aerogels to elastic aerogels to new SiO2 nano-fibre aerogels with flexible elastic bonds. Finally, providing regulation factors that can be improved and employed in future experiments. Giving prospects and focus for future research.
Preparation and Consolidation Mechanism of Nickel Laterite Carbon Composite Hot Briquette
Authors: Huang Zhuang , Xing Zhenxing , Cheng Gongjin , Liu Jianxing , Xue Xiangxing , Ding Xueyong
Published: June 2022

Blast furnace smelting process has advantages in producing ferronickel products because of its low comprehensive energy consumption and high production efficiency. However, laterite nickel ore has poor performance of pellets and lump ore due to its own characteristics. At present, the main lumping method is low basicity sinter, which is difficult to optimize the charge structure. This paper mainly studies the preparation process of laterite nickel carbon composite hot briquette (LN-CCHB) and the influence of process parameters on the basic compressive strength properties, so as to explore a new charge for smelting laterite nickel in blast furnace process. Results showed that the influence of pressure and temperature of hot briquette on the compressive strength of NL-CCHB is obvious. The compressive strength of NL-CCHB increases with the increase of briquetting pressure increases first and then decreases with the increase of hot briquetting temperature. The FC/O ratio (the ratio of the fixed carbon mol (C) in coal to the reducible oxygen mol (O) in iron oxides) has little effect on the compressive strength of NL-CCHB. In the experimental range, the mixture of laterite nickel ore and pulverized coal can obtain NL-CCHB with compressive strength of more than 1300N after hot briquetting. After heat treatment, NL-CCHB with compressive strength of more than 1800N can be obtained. The optimum hot briquetting process parameters are: FC/O ratio 1.25, hot briquetting temperature 450°C, hot briquetting pressure 80MPa. The optimum heat treatment process parameters are: FC/O ratio 1.50, heat treatment temperature 550°C.
Study on fabrication technology and corrosion resistance of Fe-based amorphous alloy coatings by high-speed laser cladding
Authors: Wu Jianpeng , Wang Yuyue , Niu Qiang , Zhang Jingchun
Published: June 2022

In this paper, the AME201 Fe-based amorphous alloy coating was prepared by ultra-high speed laser cladding on the surface of 27SiMn alloy steel. The effects of technological parameters on the surface morphology, micro-structure and dilution rate of coating. Corrosion resistance and weight loss of matrix, AME201Fe coating, 316L coating and Fe901 coating were studied by salt spray corrosion test. The results show that the thickness of AME201Fe coating is mostly affected by powder feeding, laser power and scanning speed have a huge impact on the width of coating, and the dilution rate increased from 0.13% to 29% with the change of laser power, nearly several hundreds of times. The results of salt spray test show that the AME201Fe coating has the minimum weight loss value at each stage compared with the matrix, 316L coating and Fe901 coating, which can play a good role in surface protection because of less internal defects and no grain boundary dislocations.
Genome of the bee Holcopasites calliopsidis—a species showing the common apid trait of brood parasitism
Authors: Sless Trevor J L , Searle Jeremy B , Danforth Bryan N
Published: June 2022

Brood parasites represent a substantial but often poorly studied fraction of the wider diversity of bees. Brood parasitic bees complete their life cycles by infiltrating the nests of solitary host bees thereby enabling their offspring to exploit the food provisions intended for the host’s offspring. Here, we present the draft assembly of the bee Holcopasites calliopsidis, the first brood parasitic species to be the subject of detailed genomic analysis. Consistent with previous findings on the genomic signatures of parasitism more broadly, we find that H. calliopsidis has the smallest genome currently known among bees (179 Mb). This small genome does not appear to be the result of purging of repetitive DNA, with some indications of novel repetitive elements which may show signs of recent expansion. Nor does H. calliopsidis demonstrate any apparent net loss of genic content in comparison with nonparasitic species, though many individual gene families do show significant contractions. Although the basis of the small genome size of this species remains unclear, the identification of over 12,000 putative genes—with functional annotation for nearly 10,000 of these—is an important step in investigating the genomic basis of brood parasitism and provides a valuable dataset to be compared against new genomes that remain to be sequenced.
Ileo-ileal intussusception due to inflammatory fibroid polyp: a rare cause of small bowel obstruction in adults
Authors: Saeed Rafeh , Hassan Mekki , Tul-Zahra Fatima , Neary Peter
Published: June 2022

Intussusception in adults is a relatively uncommon occurrence for a cause of bowel obstruction, which can present acutely, chronically or in an acute on chronic fashion. It is clinically concerning because of the possibility of cancer acting as a lead point. Small bowel tumours are rare, mostly detected incidentally with small bowel obstruction. Inflammatory fibroid polyp (IFP) is a rare benign tumour of the small bowel, either detected incidentally on imaging or endoscopy carried out for other reasons, or presents with acute features. We present a case of small bowel intussusception caused by IFP within the distal third of the ileum as a leading point. The patient presented acutely with small bowel obstruction, on a background of recurrent non-specific abdominal pain over the preceding month, and the computed tomography scan revealed an intussusception that was timely managed with a laparoscopy-assisted small bowel segmental resection.
Management of a rare, giant multicompartmental lipoma of the hand: a case report and review of the literature
Authors: Shah Rushabh K , Rahman Shakeel M , Pywell Matthew , Ibanez Javier
Published: June 2022

Lipomas are the commonest benign tumour, made up exclusively of adipose tissue, and can arise anywhere in the body. However, giant lipomas of the hand, defined as >5 cm in diameter, are rare. They have the potential to invade into surrounding areas and cause a multitude of symptoms due to the compression and proximity of underlying structures. We describe a case of a 64-year-old woman who presents with a swelling of the left thenar eminence, associated with numbness and tingling in all fingers. Magnetic resonance imaging and nerve conduction studies confirmed the diagnosis of a lipoma causing median nerve compression. The patient underwent elective surgical excision with good postoperative recovery. The excised lesion, measuring 12 × 7 × 2.4 cm, is one of the largest giant lipomas of the hand reported in literature, and the first to demonstrate invasion from the mid palmar space into both the dorsal sub-aponeurotic space and carpal tunnel.
Bounded model checking distributed temporal logic
Authors: Peres Augusto , Ramos Jaime , DionÍsio Francisco
Published: June 2022

The distributed temporal logic (DTL) is a logic for reasoning about temporal properties of distributed systems from the local point of view of the system’s agents, which are assumed to execute sequentially and to interact by means of synchronous event sharing. Different versions of DTL have been proposed over the years for a number of different applications, reflecting different perspectives on how non-local information can be accessed by each agent. In a recent paper, an automata-theoretic approach to model check DTL was proposed Subtil et al. (2020, Technical Report). Herein, we follow a different approach and adapt the bounded model-checking (BMC) algorithm for linear temporal logic to the case of DTL (see Biere et al. (2003, Adv. Comput., 58, 117–148) and Biere et al. (1999, TACAS 1999, 193–207)). For that purpose, a new notion of bounded semantics for DTL is proposed. In the BMC approach, the witness problem is translated to the satisfiability of a propositional formula that can be addressed (efficiently) by SAT solvers. An important application for this approach is verification of security protocols (Basin et al. (2011, Theoret. Comput. Sci., 412, 4007–4043); Caleiro et al. (2005, Electron. Notes Theor. Comput. Sci., 125, 67–89)).
Coronavirus Disease 2019 On Board a Submarine: A Retrospective Review
Authors: Weinberg Daniel , Edgar Mia , Majewski Michael , Wakefield Rozlyn
Published: June 2022

Background

The submarine environment presents unique challenges in mitigating the spread of respiratory viruses because of the re-circulatory atmosphere and lack of ability to physically distance. The atmosphere of a submarine is periodically ventilated and continuously scrubbed. However, the air is recycled for months until the ship is able to ventilate. An outbreak of coronavirus disease 2019 (COVID-19) occurred on a U.S. Navy fast-attack nuclear submarine (SSN) with a crew of 128 personnel.

Methods

Demographics, symptom data, and test results for all crew members on board during the outbreak were collected. Testing was completed by real-time reverse-transcriptase polymerase chain reaction, and symptom data were collected via a patient-reported online application. Symptom results were collected from August 4, 2020 to September 1, 2020.

Results

The crew was 100% male, with a mean age of 27.0 years. All crew members met the stringent medical standards for submarine and sea duty. Fifty-five Sailors tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (43.0% of the crew) during the outbreak. Additionally, nine Sailors (7.0% of the crew) met the criteria for infection despite testing negative, resulting in an overall attack rate of 50.0%. Among the 64 crew members with suspected or confirmed COVID-19, 1 (1.6%) was hospitalized. There were no deaths. Out of the 55 positive tests, there were 6 (10.9%) asymptomatic positive cases.

Conclusions

As expected, SARS-CoV-2 was able to spread rapidly among a submarine crew. In 11 days, the infection spread to 64 total crewmembers out of 128. Outbreaks such as these have played a role in future COVID-19 testing and mitigation protocols that have affected day-to-day operations.
Comparison of baseline characteristics and postoperative complications in neuromuscular, syndromic and congenital scoliosis
Authors: Deveza Lorenzo R. , Chhabra Barkha N. , Heydemann John , Hung Chun , Vanorny Dallas , Birhiray Dion , Dahl Benny
Published: June 2022

Nonidiopathic scoliosis encompasses a group of diagnoses, including neuromuscular scoliosis, syndromic scoliosis and congenital scoliosis. The objective of this study was to compare the preoperative and postoperative clinical differences in pediatric nonidiopathic scoliosis patients with neuromuscular scoliosis vs. syndromic scoliosis/congenital scoliosis. This is a single-center retrospective review of all pediatric patients undergoing spinal instrumentation for nonidiopathic scoliosis during a 5-year period. Neuromuscular scoliosis patients (n = 144), syndromic scoliosis patients (n = 44) and congenital scoliosis patients (n = 52) were compared. Demographics, patient characteristics and outcomes were compared. Neuromuscular scoliosis patients had lower BMI z-scores and were more likely to have pulmonary disease, technology dependence and seizure disorder. Additionally, neuromuscular scoliosis patients underwent bigger procedures with more levels fused and a higher rate of pelvis fixation. By direct comparison, neuromuscular scoliosis patients tended to have more complications including deep surgical site infections, readmission in 30 days, return to operating room in 90 days and emergency care visits in 90 days. When controlling for the differences in their preexisting conditions and surgical procedure, we found that pelvic fixation was a major confounding factor, whereas the others had no effect. We further subanalyzed cerebral palsy patients and found this group to exhibit no difference in complications compared to other neuromuscular scoliosis subtypes. Neuromuscular scoliosis patients have different characteristics and subsequent postoperative complications than those with syndromic scoliosis and congenital scoliosis. The difference in complication profile is mainly due to differences in surgical procedure and a higher rate of pelvic fixation. This should be considered when planning nonidiopathic scoliosis surgery among multidisciplinary teams.
Role of islatravir in HIV treatment and prevention: an update
Authors: Derbalah Abdallah , Karpick Hayley Christine , Maize Holly , Skersick Preston , Cottrell Mackenzie , Rao Gauri G.
Published: June 2022

Purpose of review

To summarize recent updates on the potential role of islatravir for HIV treatment and prevention.

Recent findings

Islatravir is an investigational antiretroviral agent with unique pharmacologic properties that facilitate flexible dosing regimens. Islatravir has demonstrated potent antiviral activity and a high barrier to resistance when combined with doravirine and lamivudine. A simplified two-drug HIV treatment regimen of islatravir combined with doravirine has also demonstrated comparable efficacy to standard of care three-drug regimens. The long half-life and high potency of islatravir's active metabolite may support its use as a long-acting option for HIV preexposure prophylaxis (PrEP). A once monthly oral dose of islatravir maintains effective concentrations of its active metabolite over the entire dosing interval. Furthermore, an investigational implantable formulation has been projected to provide efficacious concentrations for at least a year and exhibits comparable distribution into vaginal and rectal tissues making it a promising PrEP option for male and female individuals. Islatravir has minimal risks of drug interactions as it is not a substrate, inducer, or inhibitor of major drug metabolizers and transporters. Finally, clinical trials demonstrate islatravir's favorable safety profile revealing only mild and transient adverse events.

Leveraging the unique pharmacological properties of islatravir offers opportunities for simplified HIV treatment regimens and long-acting PrEP making it a valuable addition to the antiretroviral arsenal.
Sirtuin1 inhibitor attenuates hypertension in spontaneously hypertensive rats: role of Giα proteins and nitroxidative stress
Authors: Arifen Nahida , Li Yuan , Srivastava Ashok K. , Anand-Srivastava Madhu B.
Published: June 2022

Background:

We recently showed that vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) exhibit overexpression of Sirtuin1 (Sirt1) that contributes to the enhanced expression of Giα proteins implicated in the development of hypertension in SHR.

Method:

The present study investigated if the inhibition of Sirt1 could also ameliorate hypertension in SHR and explore the underlying molecular mechanisms. For this study, a selective inhibitor of Sirt1, EX-527 (5 mg/kg of body weight), was injected intraperitoneally into 8-week-old SHR and age-matched Wistar Kyoto (WKY) rats twice per week for 3 weeks. The blood pressure (BP) and heart rate was measured twice a week by the CODA noninvasive tail cuff method.

Results:

The high BP and augmented heart rate in SHR was significantly attenuated by EX-527 treatment, which was associated with the suppression of the overexpression of Sirt1 and Giα proteins in heart, VSMC and aorta. In addition, the enhanced levels of superoxide anion, NADPH oxidase activity, overexpression of NADPH oxidase subunits and FOXO1 were attenuated and the decreased levels of endothelial nitric oxide synthase (eNOS), nitric oxide and increased levels of peroxynitrite (ONOO-) and tyrosine nitration in VSMC from SHR were restored to control levels by EX-527 treatment. Furthermore, knockdown of FOXO1 by siRNA also attenuated the overexpression of Giα-2 and NADPH oxidase subunit proteins and restored the decreased expression of eNOS in VSMC from SHR.

Conclusion:

These results suggest that the inhibition of overexpressed Sirt1 and its target FOXO1 through decreasing the enhanced levels of Giα proteins and nitro-oxidative stress attenuates the high BP in SHR.
Association of home and office systolic and diastolic hypertension with glucose metabolism in a general population: the Ohasama study
Authors: Tatsumi Yukako , Satoh Michihiro , Asayama Kei , Murakami Takahisa , Hirose Takuo , Hara Azusa , Tsubota-Utsugi Megumi , Inoue Ryusuke , Kikuya Masahiro , Nomura Kyoko , Metoki Hirohito , Hozawa Atsushi , Katagiri Hideki , Imai Yutaka , Ohkubo Takayoshi
Published: June 2022

Objective:

This study was performed to investigate the association of hypertension subtypes with glucose metabolism among the Japanese general population.

Methods:

The study involved 646 residents (mean age: 62.4 years) without treatment for hypertension or a history of diabetes from Ohasama, a rural Japanese community, who underwent an oral glucose tolerance test. Hypertension subtypes [normotension, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic and diastolic hypertension (SDH)] were defined on the basis of home and office SBP and DBP (HBP and OBP, respectively). The estimated means of blood glucose related indices among the groups were compared by analysis of covariance adjusted for possible confounding factors.

Results:

Blood glucose related indices were not different among the morning HBP-defined hypertension subtypes. Participants with evening HBP-defined ISH had a significantly higher estimated mean BG at 120 min, higher homeostasis model assessment-insulin resistance (HOMA-IR) and lower Matsuda–DeFronzo index than participants with NT (all P < 0.021). Participants with OBP-defined SDH had a significantly higher estimated mean fasting blood glucose; blood glucose at 30, 60 and 120 min; and HOMA-IR and a lower Matsuda–DeFronzo index than participants with NT (all P < 0.0025).

Conclusion:

The blood glucose related indices were different among hypertension subtypes. Participants with evening HBP-defined ISH and OBP-defined SDH had higher blood glucose levels and insulin resistance than participants with correspondingly defined normotension, while those with morning HBP did not. These findings suggest the importance of measuring evening HBP and office blood pressure for early detection of coexisting hypertension and diabetes.
Spot urinary sodium to monitor relative changes in population salt intake during the UK salt reduction programme
Authors: Tan Monique , Wang Changqiong , Song Jing , He Feng J. , MacGregor Graham A.
Published: June 2022

Objectives:

The most accurate method to measure population salt intake is to collect the complete 24-h urinary sodium excretion (24-h UNa) but it is resource intensive and is rarely carried out frequently. We, therefore, assessed the use of spot urinary sodium concentration to monitor relative changes in population salt intake in between 24-h urine surveys.

Methods:

We used 24-h (n = 2020) and spot urine (n = 21 711) samples drawn from adult participants in separate, cross-sectional, nationally representative surveys in England, repeated between 2006 and 2014.

Results:

As population average 24-h UNa fell from 2006 to 2014 (from 8.7 to 7.6 g/day, i.e. by 12%) with the ongoing salt reduction programme, spot sodium concentration fell by a similar extent (from 106.1 to 93.1 mmol/l, i.e. by 13%). The regression slopes of 24-h UNa and spot sodium concentration ran parallel (P value = 0.1009) in a linear regression modelling the difference in their year-on-year changes [by regressing the 24-h UNa or sodium concentration values on time, estimation method (24-h versus spot), and their interaction term]. In contrast, when 24-h UNa was estimated by applying the Kawasaki, Tanaka, or INTERSALT formulas to spot sodium concentrations, almost no change was detected from 2006 to 2014 (±1%) and their regression slopes were significantly different from that of the measured 24-h UNa (all P values <0.0001).

Conclusion:

Spot urinary sodium concentration drawn from random and representative samples of the population accurately reflected relative changes in population average 24-h UNa, and can therefore, be used in between 24-h urine surveys to monitor population salt reduction programmes. Formulas commonly used to estimate 24-h UNa were unsuitable to do so.
Role of the angiotensin type 1 receptor in modulating the carotid chemoreflex in an ovine model of renovascular hypertension
Authors: Sohn Chris Sung-Eun , Chang Joshua Wen-Han , George Bindu , Chen Siyi , Ramchandra Rohit
Published: June 2022

Objective:

The carotid body has been implicated as an important mediator and putative target for hypertension. Previous studies have indicated an important role for angiotensin II in mediating carotid body function via angiotensin type-1 receptors (AT1R); however, their role in modulating carotid body function during hypertension is unclear.

Methods:

Using a large preclinical ovine model of renovascular hypertension, we hypothesized that acute AT1R blockade would lower blood pressure and decrease carotid body-mediated increases in arterial pressure. Adult ewes underwent either unilateral renal artery clipping or sham surgery. Two weeks later, flow probes were placed around the contralateral renal and common carotid arteries.

Results:

In both hypertensive and sham animals, carotid body stimulation using potassium cyanide caused dose-dependent increases in mean arterial pressure but a reduction in renal vascular conductance. These responses were not different between groups. Infusion of angiotensin II led to an increase in arterial pressure and reduction in renal blood flow. The sensitivity of the renal vasculature to angiotensin II was significantly attenuated in hypertension compared with the sham animals. Systemic inhibition of the AT1R did not alter blood pressure in either group. Interestingly carotid body-evoked arterial pressure responses were attenuated by AT1R blockade in renovascular hypertension but not in shams.

Conclusion:

Taken together, our findings indicate a decrease in vascular reactivity of the non-clipped kidney to angiotensin II in hypertension. The CB-evoked increase in blood pressure in hypertension is mediated in part, by the AT1R. These findings indicate a differential role of the AT1R in the carotid body versus the renal vasculature.
Recurrent Pott Puffy Tumor in a Child With Frontonasal Dermoid: An Unusual Presentation
Authors: Agarwal Pallavi , Pandhi Aashima , Litra Florentina , Barr Lori
Published: June 2022

We present a case of Pott puffy tumor in a 21-month-old male, the youngest patient ever reported to have developed this complication and the first ever to have developed recurrence from an infected frontonasal dermoid. Hence, by reporting this case, we want to raise awareness about the importance of early recognition of Pott puffy tumor; and the need to meticulously evaluate and resect any craniofacial dermoid that could potentially lead to recurrence and intracranial complications if left unrecognized.
Overlapping Signs and Symptoms Between Recurrent Varicella and Pityriasis rosea Gibert
Authors: Baba Koichi , Baba Tomoko , Ogra Pearay L. , Okuno Toshiomi
Published: June 2022

Background:

Pityriasis rosea Gibert (PRG) has features similar to those of common infectious childhood diseases, suggesting a viral cause, but no agent has been identified to date. We describe 4 children with PRG and 2 with recurrent varicella who were studied using photochronography, virology and immunology.

Methods:

The 6 patients with skin rashes visited our pediatric clinic from April 2012 to May 2016. Photographs of their skin lesions were taken; blood, skin lesions, and/or nasal lavage samples were collected to detect varicella-zoster virus (VZV) DNA and antibodies; and skin tests were carried out to measure cell-mediated immunity to VZV.

Results:

Herald patches were confirmed in 2 of 4 PRG patients. No specimen cultures were positive for infectious VZV. However, VZV-DNA was detected in skin lesions of 3 PRG patients. During the acute phase, 5 patients had IgG antibodies to VZV, and skin-test reactions were positive in 5 patients.

Conclusions:

IgG antibody titers to VZV at rash onset were high, suggesting that they were already rising at the appearance of the rash and that reinfection with VZV must have occurred during the prodromal stage or several weeks before rash appearance in PRG patients whose immunity had declined below the threshold. Our study suggests a new pathogenesis of PRG that might help to address incongruities of past theories on PRG sites of viral entry and replication, incubation period and variations in the clinical course of PRG from prodrome to healing.
Timing of Monovalent Vaccine Administration in Infants Receiving DTaP-based Combination Vaccines in the United States
Authors: Marshall Gary S. , Petigara Tanaz , Liu Zhiwen , Wolfson Lara , Johnson David , Goveia Michelle G. , Chen Ya-Ting
Published: June 2022

Background:

The recommended US infant immunization schedule includes doses of diphtheria, tetanus, acellular pertussis (DTaP), inactivated poliovirus (IPV), Haemophilus influenzae type b (Hib) and hepatitis B virus (HepB) during the first 6 months of life. Little information is available about the timing of associated, complementary monovalent vaccine administration in infants receiving DTaP-based pentavalent combination vaccines.

Methods:

This was a retrospective cohort study of infants born between July 1, 2010, and June 30, 2018, in the US MarketScan commercial claims and encounters database. Descriptive statistics were used to assess vaccine administration patterns. Multivariate logistic regression was performed to explore factors associated with coadministration of DTaP-IPV/Hib and HepB.

Results:

Among infants who received DTaP-HepB-IPV (n = 129,885), 93.7% had claims for at least 2 Hib doses; most (91.5%‐98.3%) of these doses were administered on the same day as DTaP-HepB-IPV doses. Among infants who received DTaP-IPV/Hib (n=214,172), 95.3% had claims for ≥2 doses of HepB. Although coverage was high, 59.2% received the second HepB dose on the same day as the first DTaP-IPV/Hib dose, and 44.6% received the third dose of HepB on the same day as the third DTaP-IPV/Hib dose. Differences in coadministration of the second and third HepB doses with DTaP-IPV/Hib were associated with the region of residence, provider type, health plan type and coadministration of pneumococcal conjugate vaccine and rotavirus vaccine.

Conclusions:

Almost all infants received the appropriate, complementary monovalent vaccine series. However, this study found variability in the timing of HepB doses in relation to DTaP-IPV/Hib doses with many infants not completing the HepB series until 9 months of age.
Adherence to Recommendations for Βacillus Calmette-Guérin Vaccination of High-risk Neonates in Greece
Authors: Maltezou Helena C. , Magaziotou Ioanna , Tseroni Maria , Syrigonaki Katerina , Syrogiannopoulos George A. , Tsolia Maria , Roilides Emmanuel , Theodoridou Maria , Georgakopoulou Theano
Published: June 2022

In 2016 a Βacillus Calmette-Guérin vaccination policy targeting high-risk neonates for tuberculosis before discharge from maternity hospital was adopted in Greece. Vaccination rates were 38.2% in 2019 and 24.7% in 2020. Vaccination coverage varied by risk group (higher for neonates in close contact with an active noncompliant or multidrug-resistant tuberculosis case and lower for Roma and immigrant neonates).
Extended Work Shifts Increase Subjective Pain Complaints Among Cabin Crewmembers, but Not Among Airline Pilots or Healthcare Workers
Authors: Matre Dagfinn , Goffeng Elisabeth , Nordby Karl-Christian , Lie Jenny-Anne S.
Published: June 2022

Objective

To determine whether four consecutive extended work shifts are associated with an increased risk of subjective pain complaints, sleep duration, and sleep disturbances.

Methods

Forty-three healthcare workers, 41 cabin crewmembers, and 18 airline pilots working 4 consecutive extended workdays reported subjective pain complaints and sleep after the 1st and 4th workday.

Results

The risk of headache (odds ratio [OR] 21.4, 95% confidence interval [CI] 1.85 to 246.5) and pain in the hands, arms, or wrists (OR 3.78, 95% CI 1.84 to 7.76) increased after workday 4 versus workday 1 in cabin crewmembers. Sleep duration was longer (0.6 to 1.1 hours), and sleep disturbances fewer, the night before the fourth extended workday, compared with before the first workday, in all occupations.

Conclusions

We found no general support for an association between extended work shifts and subjective pain, whereas sleep duration was improved, and sleep disturbances reduced after 4 consecutive extended workdays.
Giant Cholesteatoma: A Case Report and Review of the Literature
Authors: Wong Wai Keat , Lee Michael Fook-Ho , Saxby Alexander J.
Published: June 2022

Objective

To present a case of giant cholesteatoma and review of the contemporary literature.

Patients

A 61-year-old male presented with foul-smelling discharge from his right ear in the setting of a previous canal wall down mastoidectomy. Otomicroscopy demonstrated a mastoid cavity filled with infected keratinous debris. Neuro-imaging revealed soft tissue inflammatory changes in the mastoid cavity, with involvement of the temporomandibular joint (TMJ) and parotid gland and tegmen erosion. Biopsies showed evidence of desquamated epithelium consistent with cholesteatoma, with no malignant cells identified. Audiogram demonstrated a mean hearing loss of 65 dB on the right ear and an air-bone gap of 45 dB. Review of literature was also performed on giant cholesteatoma.

Interventions

He underwent a modified Fisch Type B infratemporal fossa approach to completely remove the cholesteatoma and a vascularized free flap was utilized to fill the surgical defect.

Main Outcome Measures

Complete extirpation of choles-teatoma and resolution of otorrhoea.

Results

Repeat imaging showed complete removal of cholesteatoma and clinically there was resolution of the otorrhea. Review of the literature has shown a lack of consensus around the definition of giant cholesteatoma. Most cases in the literature demonstrated extensive involvement of anatomical spaces beyond the confines of the temporal bone to qualify for the diagnosis of giant cholesteatoma.

Conclusions

Giant cholesteatoma should be suspected in cases of recurrent ear discharge following canal wall down mastoidectomy. The case we report add to the literature to benefit future patients in preoperative counseling and better inform management.