bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalytic synthesis of methyl ethyl ketone from N-Butane
Authors: Fayzullaev Normurot , Kholliyev Shamsiddin
Published: August 2023

In the article, in order to evaluate the effect of various factors on the oxidation process of n-butane, a series of experiments were conducted at a temperature of 170 ℃ for 58 hours with the mixing of reactants in a reactor at a speed of 0.05 m amplitude 2s-1. Infrared spectroscopy, transmission electron microscopy, and powder X-ray diffraction data were reported. According to infrared spectroscopy, when the ratio of tetra-Npropylammonium hydroxide/tetraethoxysilane is less than 0.085, it is proved that the main product is a mixture of amorphous titanium(IV) oxide and the amorphous form of titanium(IV) oxide is amorphous silicon(IV) oxide. Powder X-ray diffraction of the samples also showed the X-ray appearance of amorphous titanium(IV) oxide peaks. According to electron microscopy, a change in the size of the catalyst particles is observed as the initial molar ratio of tetra-N-propylammonium hydroxide/tetraethylorthosilicate increases. As a result of the study of the effect of temperature on the reaction rate, it was proved that the productivity of butanone-2 increased from 13.65% to 30.85% and the conversion rate of potassium permanganate solution increased from 37.5 to 97.2% with an increase in temperature from 50 ℃ to 90 ℃. It should be noted that the initial tetra butyl titanatetetraethylorthosilicate molar ratio is xTiO2•(1-x)SiO2(x=0.0001-0.04) with 33% porosity obtained by reaction in aqueous solutions at temperatures above 100 ℃ and pressures above 1 atmosphere. ) has a significant effect on the obtained samples of the catalyst.
Investigation of the drying process of ehfef in the technology of obtaining a nanocatalyst from the retention substance bentonite
Authors: Fayzullayev N. I. , Kurbonov J. M. , Daminova G. B. , Kurbonova R. J. , Kurbonov J. J.
Published: August 2023

In this study, the study of the drying process using the energy of a convective electromagnetic field (electromagnetic field of extremely highfrequency) was considered when obtaining a nanocatalyst from bentonite of a trapping substance based on the "Zol-gel" technology. Also, the bentonite layer "Navbahor" is a textural description of samples, the effect of bentonite heating on the size of microporosity, heating from surface to surface, distribution and chemical composition of the porosity diameter in accordance with the size of unmodified bentonite.
The effect of reagents on the production of highly nanocomposite bentonite sorbents using zol-gel technology
Authors: Fayzullayev N.I. , Kurbonov J.M. , Uktamov L.U. , Kurbonova R.J. , Kurbonov J.J.
Published: August 2023

In this study, the analysis of the study of the effect of reagents upon receipt of cargo was highlighted—nanocomposite bentonite sorbents using Sol–gel technology and the results obtained were highlighted. The comparative surface surface was calculated at 77 K using a nitrogen adsorption isotherm. The size and pore size of the catalysts were determined from data on desorption and adsorption isotherms, respectively, at a relative pressure R/ro=0.99 in accordance with the BJH (Barette–Joyner–Halend) model. Bentonite in Navoi region of Navahor district is a light gray powder, odorless, practically insoluble in water and organic solvents, the pH value of the suspension is 7.1–8.7. The weak alkalinity of the suspension is explained by the presence of hydroxide soil and hydroxide metals in the clay. According to its adsorption properties, it is a combined meso–macromicrobial adsorbent, its specific surface area is 54.5 m2/g, the porosity volume is 0.065 cm3/g, the average porosity is 4.8 nm, the adsorption activity for blue methylene is 62.0 bentonite/g.
Possibility of application of high silicon keolitic catalyst with thermal and mechanochemical treatment for catalytic flavoring of the propane-butane fraction
Authors: Fayzullaev Normurot , Bobomuratova Sanobar , Ergasheva Surayyo , Xolliyev Shamsiddin , Kholmuminova Dilorom
Published: August 2023

The studies were carried out in a flow catalytic device in the stationary phase of the catalyst (catalyst volume 6 cm3), at 450–6000C, at normal atmospheric pressure (P = 0.1 MPa), was carried out under conditions in which the volumetric velocity of the initial gas mixture was 600–1000 h-1. Qualitative and quantitative composition of propane-butane fraction and reaction products were analyzed on the chromatograph “Chromatic-Crystal 5000M” under the following favorable conditions: separation of gaseous products was carried out in a column thermal conductivity detector (TCD) with a length of 3 m and a diameter of 3 mm filled with 8% NaOH / Al2O3. The separation of liquid products was carried out in a DV-1 capillary quartz column (30 m x 0.25 μm), and detection was carried out in a flame ionization detector. Check the acidity of the catalysts. The acid characteristics of the samples were studied by the method of the programmed desorption of ammonia in the automatic chemisorption analyzer “USGA-101”. X-ray phase analysis: X-ray examination of the samples (X-ray phase analysis) was performed on a diffractometer XRD-6100 (Shimadzu, Japan). Phase identification was performed based on radiographs of individual components (JSPDS card index) based on data from the literature. The purpose of this work is to study the possibility of using thermally and mechanochemically treated high-silicon zeolite catalysts in the catalytic aromatization of the propane-butane fraction and acid properties.
Resonance multiphoton ionization of alkaline Earth Ca, Ba, Sr atoms
Authors: Tursunov М. , Gaibnazarov B. , Bakieva Kh. , Eltazarov B. , Alimova Z.
Published: August 2023

In this work, we study the process of three-photon resonant ionization of alkaline earth atoms Ca, Sr, and Ba. To carry out the experiments, a frequency-tunable laser setup was created. An effusive beam of alkali atoms served as an atomic target.
Processing of serpentenites of the Arvaten deposit of Uzbekistan with the use of ammonium sulphate
Authors: Pirimov Tuychi , Namazov Shafoat , Seytnazarov Atanazar , Temirov Uktam , Usanboyev Najmiddin
Published: August 2023

The article presents the results of a study of the processes of obtaining magnesium oxide by fusing serpentinites of the Arvaten deposit in the presence of ammonium sulfate, followed by grinding and treatment with water to separate silica from the suspension, neutralizing the filtrate with ammonia to pH 8.5 for precipitation and separation of impurity metal ions, precipitation and separation of ions magnesium from solution using ammonia and ammonium carbonate, thermal decomposition of magnesium corbanate to obtain magnesium oxide. It has been established that the use of ammonium sulfate for fusion of serpentite at a ratio of serpentenite: (NH4)2SO4 = 100: 201.77 and further processing of the resulting solutions allows you to obtain magnesium oxide with a composition (wt.%): MgO - 97.55; Fe2O3 - 0.86; A12O3 - 0.12; CaO - 0.18; SO3 - 0.48.
Comparison of Methods for Point of Care Preparation of Autologous Platelet Gel
Authors: Kevy Sherwin V. , Jacobson May S.
Published: August 2023

A platelet gel (PG) is produced by the addition of calcium chloride and thrombin to a platelet concentrate (PC). PG releases multiple growth factors, which have the ability to initiate and stimulate one growth factor's function in the presence of others. This finding has resulted in the use of PG in orthopedic, plastic, and reconstructive surgery. The study compared the commercial systems available for the preparation of PG. All procedures were performed according to the manufacturers directions. The devices were evaluated with respect to ease of use, collection efficiency, platelet quality, and growth factor release. The SmartPRep® requires only four processing steps compared to 12 to 24 required by other devices. The SmartPReP® and the CATS® were the most reproducible, as evidenced by their low coefficient of variation of 13% and 16%. The mean platelet yield was 72% for the SmartPReP®, 58% for the 3iPCCS, 54% for the Sequestra®, 31% for the Secquire®, 31% for the CATS®, 27% for the Interpore Cross®, and 42.6% for the Biomet GPS™. The mean total amount of PDGF-AB and TGF-B1 obtained from the SmartPReP® is greater than other systems evaluated. The SmartPReP® produced a consistent PC with a yield that was four times baseline range with the lowest coefficient of variation.
Evaluation of the Hemobag: A Novel Ultrafiltration System for Circuit Salvage
Authors: Roeder Ben , Graham Susan , Searles Bruce , Darling Edward
Published: August 2023

Following termination of bypass, the CPB circuit contains a significant volume of diluted blood. Various methods have been used to salvage this blood, including direct transfusion or centrifugation /washing of the circuit volume. These techniques produce a reinfusion product that is either dilute or free of plasma proteins. The purpose of this study is to evaluate the Hemobag ultrafiltration system, which may overcome these limitations. Yorkshire pigs (n = 4, ∼40 kg) were placed on CPB (prime volume 1.5 L) for 60 min. Following CPB, control blood samples (Pre) were collected from the circuit. The circuit contents were then transferred into a Hemobag and processed. Blood samples (post) were then collected from the Hemobag. Pre- and post-samples were analyzed and compared using a Studen’s t-test. Parameters that were significantly different (p < .05) pre-Hemobag versus post-Hemobag were as follows: hematocrit 20.4 ± 3.4% vs. 54.1 ± 11.6%, total protein 2.4 ± 0.4 vs. 8.2 ± 2.9 gms/DL, fibrinogen 92.0 ± 20.3 vs. 305.8 ± 137.2 mg/DL. Parameters that were not significantly different but trended toward an increase post-Hemobag were platelet counts, heparin levels, white cell count, and plasma free hemoglobin. Parameters that showed no differences or trends included sodium, potassium, chloride, bicarbonate, and osmolarity. Processing times were measured at approximately 10 minutes. This device effectively concentrates post-bypass circuit volume, providing a product that is high in red blood cells and plasma proteins and may provide an alternative to current techniques for circuit volume salvage.
A non-linear multiscale chemo-mechanical model describing the delayed evolution of concrete structures in marine environments
Authors: El-Khoury Marinelle , Grondin Frédéric , Roziere Emmanuel , Cortas Rachid , Chehade Fadi Hage
Published: August 2023

The failure of offshore structures is a major issue as they lead to economic, environmental, and social disasters. Assessing the durability and long-term behavior of these structures subjected to chemical and mechanical degradation is subsequently critical. The analysis of these coupled phenomena induced by seawater attack and mechanical loading is complex and requires the development of innovative measurement systems and modelling strategies. Thus, multiscale protocols, starting from the microscopic scale of the cement paste, seems relevant for the characterization of the chemo-mechanical behavior of offshore structures. Therefore, the competition between protective layers' formations and harmful effects of seawater ions has been coupled with the creep phenomenon.
A Retrospective Analysis of Pinnaplasty Outcomes: The Welsh Experience
Authors: Kadhum Murtaza , Atherton Samuel , Jawad Ali , Wilson-Jones Nick , Javed Muhammad Umair
Published: August 2023

Prominent ears (PEs) are the most frequent congenital external ear deformity, occurring in ∼5% of the population. Although the deformity does not usually cause functional difficulties, it can significantly affect the patient's psychological and social health. The authors aim to present the Welsh experience of pinnaplasty, reviewing our outcomes and complications. A retrospective cross-sectional study was performed of all patients undergoing pinnaplasty in Morriston Hospital, Swansea, Wales. We represent the tertiary plastic surgery referral unit across Wales. We included all patients undergoing pinnaplasty between 2015 and 2022 inclusive. We excluded patients undergoing revision procedures or those who had no follow-up. Over the 7-year period, 236 pinnaplasties were performed and 203 were included in the analysis. Ninety-six percent of cases were performed using a cartilage-sparing approach, which represents the mainstay in our unit. The mean follow-up length for our cases was 12 months. Revision procedures were required in 4% of cases. Three hematomas (1.5%) and one (0.5%) wound dehiscence due to infection were recorded and required a return to the operating room. Suture extrusion was noted in 5% of cases (10 patients); 4.5% (9) cases were affected by either hypertrophic or keloid scarring. Across the United Kingdom, cosmetic procedures have come under scrutiny, namely, because of a difficult economic climate. In the era of tight fiscal control in health care, it is pertinent to analyze the outcomes and performance metrics of our operations regularly, thus aiding in the development of an established evidence base to advocate for our respective patients.
Analysis of the Anatomical Variations in Sylvian Fissure Using MRI
Authors: Aranha Kevin N. , Mijar Mahesh , Bhat Malathi
Published: August 2023

Background The most common surgical approach in neurosurgery to diagnose and treat tumors and aneurysms is the transylvian-pterional approach. The classification of Sylvian fissure (SF) was proposed based on pure anatomical observations by Yasargil. The SF is the most identifiable feature of the superolateral brain surface, which divides the parietal and frontal lobes from the temporal lobe which lies below.

Aim The aim was to identify the anatomical variations in SF (bilaterally) in the normal population and to identify its morphological asymmetry.

Setting and Design This was a retrospective, observational descriptive record-based study which was done to identify the anatomical variations and morphological asymmetry in SF (bilaterally) in the normal healthy population using a 1.5-T magnetic resonance imaging (MRI) system.

Materials and Methods The SF was classified into five types. The categorization of the SF was done by MRI, either using T1-weighted images in three planes.

Statistical Analysis Percentage and frequency using SPSS 23.0.

Results In this study, we found that type 4 was most common in the general population of 100 patients. We found type 1 was most common in age groups above 50 up to 60 years of age. Types 2 and 4 SF were found in all age groups. Bilateral presentation of the SF can be considered as symmetric in 85% of the general population and asymmetric in 15% of the population considered in this study.

Conclusion Classification of the SF types on MRI was shown to be reliable and practicable. Sound knowledge of SF anatomy before neurosurgery can help reduce procedure-related morbidity, ischemic lesions, or edema.
Management of Human Bites of “Face”
Authors: Prasanna Mita
Published: August 2023

In literature human bite of the hand has received more attention than that of face. The treatment of the human bite wounds at the two sites differ. Highlighting the reasons, the principles of management of human bites of ‘Face’ are discussed. Representative cases are reported.
Craniomaxillofacial Surgery: Anaesthetic Management
Authors: Misra Varun , Yajnik Sudarshan , Bhatnagar S. K.
Published: August 2023

Graniomaxillofacial surgery poses a major challenge to clinicians. A multidisciplinary approach is required with the anaesthesiologist playing a vital role in the outcome. The anaesthetic management of three case is presented alongwith a discussion on the problems likely to be encountered. Graniomaxillofacial surgery can be performed in any hospital equipped for Neurological, Paediatric surgery, and Plastic Surgical work.
Silastic Foam Elastomer for Dressing Open Granulating Wounds—A Preliminiary Report
Authors: Kumar Sandeep , Ramakant Ramakant , Bhattacharya Surajit , Sinha K. N. , Dubey P. C.
Published: August 2023

A preliminary report on the utility of silastic foam elastomer in the management of 32 open granulating wounds in 30 patients is presented. By offering more wound comfort to the patients and by relieving the work load of surgical residents and nurses, the silicone stent serves a dual function. The ease with which the patients can dress themselves makes such a dressing ideal for domiciliary practice. The cost of silastic foam elastomer may well balance the cumulative cost of conventional dressing material i.e. cotton gauze and bandages and their sterilization.
Snake Bite Gangrene of the Leg
Authors: Parkash Satya
Published: August 2023

A 14 year old male had gangrene of the leg following snake bite, leaving only 4 cms. skin beyond the level of knee and a thin strip of skin reaching the lower part of leg posteriorly, with an alive muscle deep to it.

A below knee amputation was achieved by utilizing the thin strip and the muscle to go round the bone stump, supplemented with limited free skin graft. This avoided an above knee amputation.
Mycosis Fungoides: A Case Report
Authors: Chandra Ramesh , Agarwal P. K. , Agarwal Mrs. Padam K.
Published: August 2023

Twenty years follow-up of a case of Mycosis fungoides is being presented here where diagnosis could be established only after 13 years after the initial onset of symptoms. It is a rare condition affecting the skin which eludes diagnosis in its early stages.
Congenital Syndactyly: An Analysis of 20 Cases*
Authors: Krishnan A.
Published: August 2023

20 cases of congenital syndactyly seen during the last 3 ½ year at the Command Hospital, Pune have been analysed, elucidating the types of the anomaly confronted, the sex incidence and the associated anomalies / syndromes. The reconstructive procedures performed on these patients are being presented whereby restoration of hand function was achieved in more than 90% of the cases.
Extranasal Rhinosporidiosis: A Case Report
Authors: Patil D. R. , Thatte M. R. , Thatte R. L.
Published: August 2023

Clinical findings, pharmacological control and the surgical treatment adopted in an unusual case of extranasal rhinosporidiosis without a nasal lesion is being presented.
Dental Wire Tightner
Authors: Singh Avtar , Sidhu Gurdev Singh , Thind Manpreet Singh
Published: August 2023

A new simple innovation for the proper tightening of eyelet wire, Gilmer wires and interosseous wires is described. This is very useful in routine as well as in difficult cases having loose or shaky teeth.
Sinophobia was popular in Chinese language communities on Twitter during the early COVID-19 pandemic
Authors: Zhang Yongjun , Lin Hao , Wang Yi , Fan Xinguang
Published: August 2023

The COVID-19 pandemic has led to a global surge in Sinophobia. We examine how Chinese language users responded to COVID-19 on Western social media by compiling a unique database (CNTweets) with over 25 million Chinese tweets mentioning any Chinese characters related to China, the Chinese Communist Party (CCP), Chinese, and Asians from December 2019 to April 2021. Our analysis of Twitter users’ self-reported geographic information shows that most Chinese language users on Twitter originated from Mainland China, Hong Kong, Taiwan, and the United States. We then adopt the Robustly Optimized Bidirectional Encoder Representations from Transformers (RoBERTa) and structural topic modeling to further analyze the sentiments, content, and topics of Chinese tweets during the COVID-19 pandemic. Our results suggest that 61.8% of tweets in our database were contributed by only 1% of Twitter users and 62.2% of tweets were negative toward China. Despite the prevalence of anti-China sentiments, the target entity analysis shows that these negative sentiments were more likely to target the Chinese government and CCP than the Chinese people. Our findings also show that the most popular topics were politics (e.g., Hong Kong protests and Taiwan issues), COVID-19, and the United States (e.g., the US-China relations and domestic issues). Anti-China users focused relatively more on political issues such as democracy and freedom, while pro-China users mentioned cultural and economic topics more. Our social network analysis reveals that these pro-China and anti-China Twitter users lacked in-depth engagement in China-related conversations and were highly segregated from each other. We conclude by discussing our contributions to China and social media studies and possible policy implications.
Quiet quitting during COVID-19: the role of psychological empowerment
Authors: Lu Mingxiao , Al Mamun Abdullah , Chen Xuelin , Yang Qing , Masukujjaman Mohammad
Published: August 2023

Due to the outbreak of the Covid-19 pandemic, Chinese university lecturers have experienced increased levels of disappointment and powerlessness due to the changing work environment. An increasing number of lecturers exhibit quiet-quitting intention, which affects their work passion, teaching quality, and so on. However, it is little known about how work-related factors, influence quiet-quitting intention of lecturers. Drawing on the social exchange theory, this study proposes a conceptual model that investigates the effects of work overload, perceived career development opportunities, perceived pay-for performance, affective organizational commitment and work conditions on job burnout, employee well-being, and quiet-quitting intention. Using a quantitative cross-sectional approach, 698 responses were obtained from young Chinese university lecturers. We also employed partial least squares structural equation modeling to analyze and forecast the extent of the impact of this study’s independent variables. The findings revealed that work overload, perceived pay-for-performance, affective organizational commitment, and work conditions significantly affect job burnout and employee well-being. Additionally, job burnout and employee well-being significantly effect quiet-quitting intention, which are moderated by psychological empowerment. Overall, this study contributes to the understanding of the factors influencing quiet-quitting intention among Chinese university lecturers, providing theoretical and practical implications for addressing the challenges arising from the Covid-19 pandemic.
Growth and mobility characterization of N-polar AlGaN channel high electron mobility transistors
Authors: Noshin Maliha , Wen Xinyi , Soman Rohith , Xu Xiaoqing , Chowdhury Srabanti
Published: August 2023

All-AlGaN based high electron mobility transistors (HEMTs) are promising for increasing the power density in both RF and power devices, improving overall efficiency. Nitrogen (N) polar GaN/AlGaN HEMTs offer lower contact resistance compared to its metal-polar counterpart. In this work, we report the metal organic chemical vapor deposition (MOCVD)-based growth of N-polar AlGaN channel HEMT structures with a varying Al mole fraction in the AlxGa1−xN channel (x = 20%, 30%, 59%, and 73%). We confirmed the high-quality morphology and the Al composition of the grown structures using atomic force microscopy and x-ray diffraction spectra, respectively. We measured a mobility of ∼160 cm2/(V.s) in our N-polar AlGaN HEMT stack (20% Al in the channel) structure and found an alloy-scattering dominated transport with increasing Al mole fraction, further supported by our simulations that consider both alloy-scattering and optical phonon-scattering mechanisms. From 20% to 59% Al composition, we found a decreasing trend in mobility while for 59%–73% Al composition in the channel, both the simulated and the experimental mobility showed a nearly saturating trend. The structures were then fabricated into HEMTs with Al0.20Ga0.80N (channel)/Al0.59Ga0.41N (barrier), showing 320 mA/mm drain current for a 4 μm long-channel device.
Time-shift selection for reservoir computing using a rank-revealing QR algorithm
Authors: Hart Joseph D. , Sorrentino Francesco , Carroll Thomas L.
Published: August 2023

Reservoir computing, a recurrent neural network paradigm in which only the output layer is trained, has demonstrated remarkable performance on tasks such as prediction and control of nonlinear systems. Recently, it was demonstrated that adding time-shifts to the signals generated by a reservoir can provide large improvements in performance accuracy. In this work, we present a technique to choose the time-shifts by maximizing the rank of the reservoir matrix using a rank-revealing QR algorithm. This technique, which is not task dependent, does not require a model of the system and, therefore, is directly applicable to analog hardware reservoir computers. We demonstrate our time-shift selection technique on two types of reservoir computer: an optoelectronic reservoir computer and the traditional recurrent network with a t a n h activation function. We find that our technique provides improved accuracy over random time-shift selection in essentially all cases.
Fundamental limitations on gain of terahertz quantum cascade lasers
Authors: Shvartsman L. D. , Laikhtman B.
Published: August 2023

We analyze the main physical processes in quantum cascade lasers with a spatial separation between the region of photon radiation and longitudinal optical (LO) phonon emission, which facilitates the depopulation of the lower level of the optical transition. Our objective is to identify the reasons for the reduction of population inversion at low photon energy and explore methods to enhance it. The expression for population inversion is derived from an equation for a simplified density matrix. This approach allows us to consider the coherence of tunneling between different levels and comprehend its influence on transition probabilities in a straightforward manner. We have found out that the energy uncertainty principle is the fundamental factor limiting population inversion in terahertz lasers. By optimizing the tunneling matrix element between the two regions and the LO phonon emission time, it is possible to significantly increase the population inversion. The optimal value for the matrix element is smaller than its maximum possible value, while the optimal LO phonon emission time exceeds the time achieved during LO phonon resonant emission.
Toward using the Villari effect for non-destructive evaluation of steel structures
Authors: Ives C. A. , Staples S. G. H. , Vo C. K. , Cowell D. M. J. , Freear S. , Varcoe B. T. H.
Published: August 2023

This work follows on from studies carried out by Jiles and Atherton on magnetic hysteresis and on the magnetomechanical effect. The Jiles–Atherton equation, which models the rate of change of magnetization with respect to stress, was solved numerically in the forward and reverse directions for stress up to 90 MPa, suggesting that stressing carbon steel will cause a lasting change in the magnetization of the sample. This was confirmed experimentally by measuring the B-field in proximity to samples of C45 steel while undergoing tensile stress, with the pattern of magnetization suggesting that the magnetic domains reorient themselves in the geomagnetic field when stressing loosens their pinning. A further experiment on two samples confirms this, with the B-field around the samples showing strong changes according to their orientation in the geomagnetic field at the time of the stressing. This work has relevance to the non-destructive testing of steel structures such as pipelines, and the relevance of the experiments to this work is considered, as well as future prospects.
Numerical and experimental investigation of flow characteristics in natural gas pipe
Authors: Chen Huiyu , Qiu Yilong , Wang Hui
Published: August 2023

To measure the natural gas flow in the natural gas pipeline, a flow measurement method based on a laser Doppler velocimeter (LDV) is proposed, and the flow field in the natural gas pipeline is accurately measured. The flow laws of the flow field in the pipeline are obtained. In this paper, the influence of the jet flow on the flow field in the main pipe during the injection of tracer particles is analyzed by numerical calculations, and the reliability of the calculation is verified by the LDV test. The results show that the influence of the jet on the flow field in the main pipe weakens rapidly within a short distance, which provides good conditions for measuring the flow in the LDV test pipeline. The error between the flow measured by LDV and the turbine standard device is within 0.47%. Meanwhile, the uncertainty of the LDV measurement test system of a natural gas pipeline is evaluated. The system uncertainty is less than 2%, which satisfies the uncertainty requirements of the metering system, verifying the feasibility of the LDV metering flow and providing a reliable basis for the accurate metering of natural gas.
Fast and cold negative ion and neutral atom beams from a water spray
Authors: Ter-Avetisyan S. , Schnürer M. , Tikhonchuk V.
Published: August 2023

High-power lasers are routinely used to generate energetic positively charged ions, and this paper reports on the observation of negative ions in these experiments. A large number of negative ions and neutral atoms at MeV energies was obtained from the interaction of a high intensity laser pulse with a water spray along with positive ions [Abicht et al., Appl. Phys. Lett. 103, 253501 (2013)]. Beams of negative ions and neutral atoms have the same properties as beams of positive ions. However, the mechanism of negative ion formation and acceleration is still under discussion. In order to gain more information about physics of generation negative ions and neutrals, we present a new experiment where all species, positive, negative ions, and neutrals, are spatially separated, and the electron capture and loss of each in water spray is evaluated. The formation of negative ions and neutral atoms of hydrogen and carbon with energies up to 140 keV and 1.2 MeV, respectively, is confirmed. It is suggested that the electrification of spray droplets plays a decisive role in these charge-exchange processes.
A classification and review of cavitation models with an emphasis on physical aspects of cavitation
Authors: Folden Tobias Simonsen , Aschmoneit Fynn Jerome
Published: August 2023

This review article presents a summary of the main categories of models developed for modeling cavitation, a multiphase phenomenon in which a fluid locally experiences phase change due to a drop in ambient pressure. The most common approaches to modeling cavitation along with the most common modifications to said approaches due to other effects of cavitating flows are identified and categorized. The application of said categorization is demonstrated through an analysis of selected cavitation models. For each of the models presented, the various assumptions and simplifications made by the authors of the model are discussed, and applications of the model to simulating various aspects of cavitating flow are also presented. The result of the analysis is demonstrated via a visualization of the categorizations of the highlighted models. Using the preceding discussion of the various cavitation models presented, the review concludes with an outlook toward future improvements in the modeling of cavitation.
Simulating excited-state complex ensembles: Fluorescence and solvatochromism in amine-arene exciplexes
Authors: Patra Abhilash , Krylov Anna I. , Mallikarjun Sharada Shaama
Published: August 2023

Exciplexes are excited-state complexes formed as a result of partial charge transfer from the donor to the acceptor species when one moiety of the donor–acceptor pair is electronically excited. The arene–amine exciplex formed between oligo-(p-phenylene) (OPP) and triethylamine (TEA) is of interest in the catalytic photoreduction of CO2 because it can compete with complete electron transfer to the OPP catalyst. Therefore, formation of the exciplex can hinder the generation of a radical anion OPP·− necessary for subsequent CO2 reduction. We report an implementation of a workflow automating quantum-chemistry calculations that generate and characterize an ensemble of structures to represent this exciplex state. We use FireWorks, Pymatgen, and Custodian Python packages for high-throughput ensemble generation. The workflow includes time-dependent density functional theory optimization, verification of excited-state minima, and exciplex characterization with natural transition orbitals, exciton analysis, excited-state Mulliken charges, and energy decomposition analysis. Fluorescence spectra computed for these ensembles using Boltzmann-weighted contributions of each structure agree better with experiment than our previous calculations based on a single representative exciplex structure [Kron et al., J. Phys. Chem. A 126, 2319–2329 (2022)]. The ensemble description of the exciplex state also reproduces an experimentally observed red shift of the emission spectrum of [OPP-4–TEA]* relative to [OPP-3–TEA]*. The workflow developed here streamlines otherwise labor-intensive calculations that would require significant user involvement and intervention.
From Feynman’s ratchet to time crystalline molecular motors
Authors: Wang Jianmei , Dai Jin , Niemi Antti J. , Peng Xubiao
Published: August 2023

Cats have an instinctive ability to use the connection governing parallel transport in the space of shapes to land safely on their feet. Here, we argue that the concept of connection, which is extensively used in general relativity and other parts of theoretical physics, also explains the impressive performance of molecular motors by enabling molecules to evade the conclusions of Feynman’s ratchet-and-pawl analysis. First, we demonstrate the emergence of directed rotational motion from shape changes, which is independent of angular momentum. Then, we computationally design knotted polyalanine molecules and demonstrate the organization of individual atom thermal vibrations into collective rotational motion, which is independent of angular momentum. The motion occurs effortlessly even in ambient water and can be further enhanced through spontaneous symmetry breaking, rendering the molecule an effective theory time crystal. Our findings can be experimentally verified via nuclear magnetic resonance measurements and hold practical potential for molecular motor design and engineering.
Power law singularity for cavity collapse in a compressible Euler fluid with Tait–Murnaghan equation of state
Authors: Krimans Daniels , Putterman Seth
Published: August 2023

Motivated by the high energy focusing found in rapidly collapsing bubbles, which is relevant to implosion processes that concentrate energy density, such as sonoluminescence, we consider a calculation of an empty cavity collapse in a compressible Euler fluid. We review and then use the method based on similarity theory that was previously used to compute the power law exponent n for the collapse of an empty cavity in water during the late stage of the collapse. We extend this calculation by considering different fluids surrounding the cavity, all of which are parametrized by the Tait–Murnaghan equation of state through parameter γ. As a result, we obtain the dependence of n on γ for a wide range of γ, and indeed see that the collapse is sensitive to the equation of state of an outside fluid.
An iron–sulfur cluster in the zinc-binding domain of the SARS-CoV-2 helicase modulates its RNA-binding and -unwinding activities
Authors: Maio Nunziata , Raza Md Kausar , Li Yan , Zhang De-Liang , Bollinger J. Martin , Krebs Carsten , Rouault Tracey A.
Published: August 2023

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, uses an RNA-dependent RNA polymerase along with several accessory factors to replicate its genome and transcribe its genes. Nonstructural protein (nsp) 13 is a helicase required for viral replication. Here, we found that nsp13 ligates iron, in addition to zinc, when purified anoxically. Using inductively coupled plasma mass spectrometry, UV-visible absorption, EPR, and Mössbauer spectroscopies, we characterized nsp13 as an iron–sulfur (Fe–S) protein that ligates an Fe
4
S
4
cluster in the treble-clef metal-binding site of its zinc-binding domain. The Fe–S cluster in nsp13 modulates both its binding to the template RNA and its unwinding activity. Exposure of the protein to the stable nitroxide TEMPOL oxidizes and degrades the cluster and drastically diminishes unwinding activity. Thus, optimal function of nsp13 depends on a labile Fe–S cluster that is potentially targetable for COVID-19 treatment.
Knock-sideways by inducible ER retrieval enables a unique approach for studying
Plasmodium-
secreted proteins
Authors: Fierro Manuel A. , Hussain Tahir , Campin Liam J. , Beck Josh R.
Published: August 2023

Malaria parasites uniquely depend on protein secretion for their obligate intracellular lifestyle but approaches for dissecting
Plasmodium
-secreted protein functions are limited. We report knockER, a unique DiCre-mediated knock-sideways approach to sequester secreted proteins in the ER by inducible fusion with a KDEL ER-retrieval sequence. We show conditional ER sequestration of diverse proteins is not generally toxic, enabling loss-of-function studies. We employed knockER in multiple
Plasmodium
species to interrogate the trafficking, topology, and function of an assortment of proteins that traverse the secretory pathway to diverse compartments including the apicoplast (ClpB1), rhoptries (RON6), dense granules, and parasitophorous vacuole (EXP2, PTEX150, HSP101). Taking advantage of the unique ability to redistribute secreted proteins from their terminal destination to the ER, we reveal that vacuolar levels of the PTEX translocon component HSP101 but not PTEX150 are maintained in excess of what is required to sustain effector protein export into the erythrocyte. Intriguingly, vacuole depletion of HSP101 hypersensitized parasites to a destabilization tag that inhibits HSP101-PTEX complex formation but not to translational knockdown of the entire HSP101 pool, illustrating how redistribution of a target protein by knockER can be used to query function in a compartment-specific manner. Collectively, our results establish knockER as a unique tool for dissecting secreted protein function with subcompartmental resolution that should be widely amenable to genetically tractable eukaryotes.
Security control of Markovian jump neural networks with stochastic sampling subject to false data injection attacks★
Authors: Yao Lan , Huang Xia , Wang Zhen , Xiao Min
Published: August 2023

The security control of Markovian jumping neural networks (MJNNs) is investigated under false data injection attacks that take place in the shared communication network. Stochastic sampled-data control is employed to research the exponential synchronization of MJNNs under false data injection attacks (FDIAs) since it can alleviate the impact of the FDIAs on the performance of the system by adjusting the sampling periods. A multi-delay error system model is established through the input-delay approach. To reduce the conservatism of the results, a sampling-period-probability-dependent looped Lyapunov functional is constructed. In light of some less conservative integral inequalities, a synchronization criterion is derived, and an algorithm is provided that can be solved for determining the controller gain. Finally, a numerical simulation is presented to confirm the efficiency of the proposed method.
Applying Image Analysis and Machine Learning to Historical Newspaper Collections
Authors: Soh Leen-Kiat , Lorang Liz , Pack Chulwoo , Liu Yi
Published: August 2023

Diving below the surface has its challenges, however. For example, “noise effects” are especially widespread when digital images have been created from earlier microphotographic copies, as is common in historical newspaper collections. Noise effects introduce interference to the primary signals of the pages, both for human vision and computer vision and processing. Various types of noise effects (fig. 1) are common, including unevenly distributed luminosity (i.e., range effects), visible characters from the other side of the page (bleed-through), tilted document scans (skewed orientation), and markings on the newspaper that obscure text (blobs).1 There is a wide range of severity for each of these effects, and images can range from very clean to very noisy within and across datasets.
Bayesian multitask learning for medicine recommendation based on online patient reviews
Authors: Cheng Yichen , Xia Yusen , Wang Xinlei
Published: August 2023

Motivation

We propose a drug recommendation model that integrates information from both structured data (patient demographic information) and unstructured texts (patient reviews). It is based on multitask learning to predict review ratings of several satisfaction-related measures for a given medicine, where related tasks can learn from each other for prediction. The learned models can then be applied to new patients for drug recommendation. This is fundamentally different from most recommender systems in e-commerce, which do not work well for new customers (referred to as the cold-start problem). To extract information from review texts, we employ both topic modeling and sentiment analysis. We further incorporate variable selection into the model via Bayesian LASSO, which aims to filter out irrelevant features. To our best knowledge, this is the first Bayesian multitask learning method for ordinal responses. We are also the first to apply multitask learning to medicine recommendation. The sample code and data are made available at GitHub: https://github.com/thrushcyc-github/BMull.

Results

We evaluate the proposed method on two sets of drug reviews involving 17 depression/high blood pressure-related drugs. Overall, our method performs better than existing benchmark methods in terms of accuracy and AUC (area under the receiver operating characteristic curve). It is effective even with a small sample size and only a few available features, and more robust to possible noninformative covariates. Due to our model explainability, insights generated from our model may work as a useful reference for doctors. In practice, however, a final decision should be carefully made by combining the information from the proposed recommender with doctors’ domain knowledge and past experience.

Availability and implementation

The sample code and data are publicly available at GitHub: https://github.com/thrushcyc-github/BMull.
Cystatin C–based estimated glomerular filtration rate and risk of stroke in the general population: a prospective cohort study
Authors: Liao Jinlan , Xiao Fei , Yang Liuqiao , Wei Yanling , Song Congying , Li Jing , Yu Sike , Lu Yueqi , Zhang Jingwen , Dai Liang , Liang Wei , Li Tao , Xiong Zuying , Wu Yangfeng , Jardine Meg J , Carrero Juan Jesus , Shan Ying , Huang Xiaoyan
Published: August 2023

Background

Previous results on the association between the estimated glomerular filtration rate (eGFR) and stroke are mixed. Most studies derived the eGFR from serum creatinine, which is affected by non-kidney determinants and thus has possibly biased the association with stroke risk.

Methods

In this cohort study, we included 429 566 UK Biobank participants (94.5% white, 54% women, age 56 ± 8 years) free of stroke at enrollment. The eGFRcys and eGFRcr were calculated with serum cystatin C and creatinine, respectively. Outcomes of interest were risk of total stroke and subtypes. We investigated the linear and nonlinear associations using Cox proportional hazards models and restricted cubic splines, corrected for regression dilution bias.

Results

During an average follow-up of 10.11 years, 4427 incident strokes occurred, among which 3447 were ischemic and 1163 were hemorrhagic. After adjustment for confounders, the regression dilution-corrected hazard ratios (95% confidence intervals) for every 10 mL/min/1.73 m2 decrement in eGFRcys were 1.10 (1.05–1.14) for total stroke and 1.11 (1.08–1.15) for ischemic stroke. A similar pattern was observed with eGFRcr, although the association was weaker. When either type of eGFR was below 75 mL/min/1.73 m2, the risks of total and ischemic stroke increased exponentially as eGFR decreased. A U-shaped relationship was witnessed if eGFRcr was used instead. There was a null association between eGFR and hemorrhagic stroke.

Conclusions

The risks of total stroke and ischemic stroke increased exponentially when the eGFRcys fell below 75 mL/min/1.73 m2.
Association of oral iron replacement therapy with kidney failure and mortality in CKD patients
Authors: Paul Shejuti , Shrestha Prabin , Sumida Keiichi , Thomas Fridtjof , Surbhi Satya , Naser Abu Mohd , Streja Elani , Rhee Connie M , Kalantar-Zadeh Kamyar , Kovesdy Csaba P
Published: August 2023

Background

Oral iron is the predominant route of iron replacement (IRT) but its benefits and safety are unclear in patients with chronic kidney disease (CKD).

Methods

We examined the association of oral IRT vs no IRT with end-stage kidney disease (ESKD) and mortality in a national cohort of US Veterans. We identified 17 413 incident new users of oral IRT with estimated glomerular filtration rates <60 mL/min/1.73 m2 and 32 530 controls who did not receive any IRT during 2004–18. We used propensity score–overlap weighting to account for differences in key baseline characteristics associated with the use of oral IRT. We examined associations using competing risk regression and Cox models.

Results

In the cohort of 49 943 patients, 1616 (3.2%) patients experienced ESKD and 28 711 (57%) patients died during a median follow-up of 1.9 years. Oral IRT was not associated with ESKD [subhazard ratio (HR) (95% confidence interval, CI) 1.00 (0.84–1.19), P = .9] and was associated with higher risk of all-cause mortality [HR (95% CI) 1.06 (1.01–1.11), P = .01]. There was significant heterogeneity of treatment effect for mortality, with oral IRT associated with higher mortality in the subgroups of patients without congestive heart failure (CHF), anemia or iron deficiency. In patient with blood hemoglobin <10 g/dL oral IRT was associated with significantly lower mortality.

Conclusion

Oral IRT was associated with lower mortality only in patients with anemia. In patients without anemia, iron deficiency or CHF, the risk–benefit ratio of oral IRT should be further examined.
Toward alert triage: scalable qualitative coding framework for analyzing alert notes from the Telehealth Intervention Program for Seniors (TIPS)
Authors: Nguyen Phuong , Schiaffino Melody K , Zhang Zhan , Choi Hyung Wook , Huh-Yoo Jina
Published: August 2023

Objective

Combined with mobile monitoring devices, telehealth generates overwhelming data, which could cause clinician burnout and overlooking critical patient status. Developing novel and efficient ways to correctly triage such data will be critical to a successful telehealth adoption. We aim to develop an automated classification framework of existing nurses’ notes for each alert that will serve as a training dataset for a future alert triage system for telehealth programs.

Materials and Methods

We analyzed and developed a coding framework and a regular expression-based keyword match approach based on the information of 24 931 alert notes from a community-based telehealth program. We evaluated our automated alert triaging model for its scalability on a stratified sampling of 800 alert notes for precision and recall analysis.

Results

We found 22 717 out of 24 579 alert notes (92%) belonging to at least one of the 17 codes. The evaluation of the automated alert note analysis using the regular expression-based information extraction approach resulted in an average precision of 0.86 (SD = 0.13) and recall 0.90 (SD = 0.13).

Discussion

The high-performance results show the feasibility and the scalability potential of this approach in community-based, low-income older adult telehealth settings. The resulting coded alert notes can be combined with participants’ health monitoring results to generate predictive models and to triage false alerts. The findings build steps toward developing an automated alert triaging model to improve the identification of alert types in remote health monitoring and telehealth systems.