bluuebunny/crossref_metadata_2025 huggingface dataset:
An orally bioavailable SARS-CoV-2 main protease inhibitor exhibits improved affinity and reduced sensitivity to mutations
Authors: Westberg Michael , Su Yichi , Zou Xinzhi , Huang Pinghan , Rustagi Arjun , Garhyan Jaishree , Patel Puja Bhavesh , Fernandez Daniel , Wu Yan , Hao Chenzhou , Lo Chieh-Wen , Karim Marwah , Ning Lin , Beck Aimee , Saenkham-Huntsinger Panatda , Tat Vivian , Drelich Aleksandra , Peng Bi-Hung , Einav Shirit , Tseng Chien-Te K. , Blish Catherine , Lin Michael Z.
Published: March 2024

Inhibitors of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (M
pro
) such as nirmatrelvir (NTV) and ensitrelvir (ETV) have proven effective in reducing the severity of COVID-19, but the presence of resistance-conferring mutations in sequenced viral genomes raises concerns about future drug resistance. Second-generation oral drugs that retain function against these mutants are thus urgently needed. We hypothesized that the covalent hepatitis C virus protease inhibitor boceprevir (BPV) could serve as the basis for orally bioavailable drugs that inhibit SARS-CoV-2 M
pro
more efficiently than existing drugs. Performing structure-guided modifications of BPV, we developed a picomolar-affinity inhibitor, ML2006a4, with antiviral activity, oral pharmacokinetics, and therapeutic efficacy similar or superior to those of NTV. A crucial feature of ML2006a4 is a derivatization of the ketoamide reactive group that improves cell permeability and oral bioavailability. Last, ML2006a4 was found to be less sensitive to several mutations that cause resistance to NTV or ETV and occur in the natural SARS-CoV-2 population. Thus, anticipatory design can preemptively address potential resistance mechanisms to expand future treatment options against coronavirus variants.
The Level of Anti-Viral Antigen-Specific Antibodies to EBNA-1 in the Serum of MS Patients Does not Depend on the Severity of the Disease
Authors: Ovchinnikova L. A. , Dzhelad S. S. , Simaniv T. O. , Zakharova M. N. , Gabibov A. G. , Lomakin Y. A.
Published: March 2024

Multiple sclerosis (MS) is an autoimmune neurodegenerative disease leading to inevitable disability and primarily affecting the young and middle-aged population. Recent studies have shown a direct correlation between the risk of MS development and Epstein–Barr virus (EBV) infection. Analysis of the titer of EBV-specific antibodies among patients with MS and healthy donors among Russian population confirmed that MS is characterized by an increased level of serum IgG binding EBNA-1 (EBV nuclear antigen 1). The number of patients with elevated levels of EBNA-1-specific antibodies does not differ statistically significantly between two groups with diametrically opposite courses of MS: benign MS or highly active MS. It can be assumed that the primary link between EBV and the development of MS is restricted to the initiation of the disease and does not impact its severity.
Unusual overlap of systemic sclerosis with Takayasu arteritis
Authors: Chithrabhanu Anoop , Ponniah Subramanian Arul Rajamurugan , Ramamoorthy Ramesh , Seetharaman Varadhan Mythili
Published: March 2024

Overlap syndromes are diseases that meet the criteria of two or more rheumatic diseases. In this case report, a woman in her 20s presented with a constellation of symptoms, including skin thickening, Raynaud’s phenomenon, hypertension, absent pulse in both lower limbs with bilateral renal artery bruit. The antinuclear antibody profile revealed Scl-70 positivity. CT thorax identified early interstitial lung disease, and nailfold capillaroscopy showed severe capillary loss. CT angiogram features were suggestive of Takayasu arteritis. Notably, there have been only four documented cases of systemic sclerosis coexisting with Takayasu arteritis, highlighting the rarity of this overlap syndrome. The diagnosis of overlap syndrome was made after a thorough history recording and clinical examination. In the presence of bilateral renal artery stenosis, managing the scleroderma renal crisis may be challenging . This patient received treatment with mycophenolate mofetil and oral corticosteroids, aiming to address both systemic sclerosis and Takayasu arteritis effectively.
Possible association between lithium intoxication and Takotsubo syndrome
Authors: Vasconcelos Mara Elisa , Mota David , Silva Tânia
Published: March 2024

More than 25 years after being diagnosed with bipolar disorder and receiving continuous treatment with lithium, a woman develops Takotsubo syndrome.
Do they stay, or do they go? Children presenting to five emergency departments across New South Wales, Australia with acute burn injuries: a retrospective review
Authors: Phillips Wayne , Southern Erin , Cattell Carol , Owens Penny , Jaques Madeleine , Melbourne Gregory , Kezhekkekara Shwetha , Frost Steven A
Published: March 2024

Objective

The overall objective of the study was to describe the disposition status of children presenting with a burn injury to five emergency departments (ED) across New South Wales (NSW), Australia.

Design

A retrospective study design was used to review routinely collected ED data.

Setting

Study sites included five acute hospitals across NSW, Australia.

Participants

During the 5-year study period between 1 January 2015 to 31 December 2020, there were 5213 paediatric burn injury presentations.

Results

The mean age of burn injury presentations was 24 months (Inter-Quartile-Range (IQR) 12–84), of which 57% (2951/5213) were males. The most common presentation time was between 16:00 and 23:59 hours (63%, 3297/5213), and the median time spent in the ED was 3 hours (IQR 1–4). The majority (80%, 4196/5213) of the burn injuries presentations did not require hospital admission. The most common principal diagnoses were ‘Burn body region unspecified’ (n=1916) and ‘Burn of wrist and hand’ (n=1060).

Conclusion

Most children who presented to the hospital with a burn injury were not admitted. Often the details of these burns were poorly recorded and a complete picture of the true burden of burn injury in children, especially the ongoing care given outside the acute hospital setting, is missing. This information is crucial, as it would inform future models of care as the paradigm shifts rapidly towards primary, ambulatory and outpatient models of care.
Development of radiographic knee osteoarthritis and the associations to radiographic changes and baseline variables in individuals with knee pain: a 2-year longitudinal study
Authors: Törnblom Margareta , Bremander Ann , Aili Katarina , Andersson Maria L E , Nilsdotter Anna , Haglund Emma
Published: March 2024

Objectives

The aim was to study the development of radiographic knee osteoarthritis (RKOA) in individuals with knee pain over 2 years, and the associations between radiographic changes and baseline variables.

Design

Longitudinal cohort study.

Participants and setting

This study is part of the Halland Osteoarthritis cohort. The included 178 individuals, aged 30–67, had knee pain, without cruciate ligament injury or radiographic findings and 67% were women. The presence of RKOA was defined as Ahlbäck score of ≥1 in ≥1 knee. (Ahlbäck grade 1: joint space narrowing in the tibiofemoral joint <3 mm). Diagnosis of clinical KOA was based on the clinical guideline from the National Institute for Health and Care Excellence (NICE). Knee injury and Osteoarthritis Outcome Score (KOOS), pain intensity, physical function, body mass index (BMI) and visceral fat area (VFA) were measured. Associations to RKOA were analysed with logistic regression (OR).

Results

In all, 13.8% (n=24) developed RKOA in 2 years whereof all had clinical KOA at baseline, as defined by NICE. Deterioration to RKOA was significantly associated with higher BMI, OR 1.119 (95% CI 1.024 to 1.223; p=0.013), and VFA, 1.008 (95% CI 1.000 to 1.016; p=0.049), worse knee pain intensity, 1.238 (95% CI 1.028 to 1.490; p=0.024), worse scores for KOOS Pain, 0.964 (95% CI 0.937 to 0.992; p=0.013) and KOOS Symptoms, 0.967 (95% CI 0.939 to 0.996; p=0.027), KOOS Activities of daily living 0.965 (95% CI 0.935 to 0.996; p=0.026) and KOOS Quality of Life 0.973 (95% CI 0.947 to 0.999; p=0.044), at baseline.

Conclusions

One out of seven individuals with clinical KOA developed RKOA in only 2 years. Baseline variables associated with RKOA after 2 years may possibly be detected early by using the NICE guideline, assessment of obesity and self-reported data of symptoms to support first-line treatment: education, exercise and weight control.

Trial registration number

ClinicalTrials.gov (NCT04928170)
Physician awareness and understanding of chronic inflammatory demyelinating polyradiculoneuropathy in Japan: a web-based study
Authors: Takeshita Yukio , Imajo Yasuaki , Oh Akinori , Kikutani Masayoshi , Okamatsu Nobuaki
Published: March 2024

Objectives

To investigate potential knowledge gaps between neurologists and non-specialists and identify challenges in the current management of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), with a focus on ‘early diagnosis’ and ‘appropriate treatment’ for CIDP.

Design

A non-interventional, cross-sectional, web-based quantitative survey of physicians working in healthcare clinics or hospitals in Japan.

Setting

Participants were recruited from the Nikkei Business Publications panel from 18 August to 14 September 2022.

Participants

Responses from 360 physicians (120 each of internists, orthopaedists and neurologists) were collected.

Outcome measures

Responses relating to a CIDP hypothetical case and current understanding were assessed to determine awareness, collaboration preferences and diagnosis and treatment decisions.

Results

Understanding of CIDP was 90.8% among neurologists, 10.8% among orthopaedists and 13.3% among internists; >80% of orthopaedists and internists answered that neurologists are preferable for treatment. Diagnostic assessment using a hypothetical case showed 95.0% of neurologists, 74.2% of orthopaedists and 72.5% of internists suspected CIDP. Among orthopaedists and internists suspecting CIDP, >70% considered referring to neurology, while ~10% considered continuing treatment without a referral. Among neurologists, 69.4% chose intravenous immunoglobulin (IVIg) as first-line treatment and determined effectiveness to be ≤3 months.

Conclusions

Orthopaedists and internists had lower CIDP awareness compared with neurologists, which may lead to inadequate referrals to neurology. Evaluation of IVIg effectiveness for maintenance therapy occurred earlier than the guideline recommendations (6–12 months), risking premature discontinuation. Improving CIDP knowledge among orthopaedists and internists is critical for better diagnosis and collaboration with neurologists. Neurologists should consider slow and careful evaluation of IVIg maintenance therapy.

Trial registration number

UMIN000048516.
Predicting parameters of airway dynamics generated from inspiratory and expiratory plethysmographic airway loops, differentiating subtypes of chronic obstructive diseases
Authors: Kraemer Richard , Smith Hans-Jürgen , Reinstaedtler Juergen , Gallati Sabina , Matthys Heinrich
Published: March 2024

Background

The plethysmographic shift volume–flow loop (sRaw-loop) measured during tidal breathing allows the determination of several lung function parameters such as the effective specific airway resistance (sReff), calculated from the ratio of the integral of the resistive aerodynamic specific work of breathing (sWOB) and the integral of the corresponding flow–volume loop. However, computing the inspiratory and expiratory areas of the sRaw-loop separately permits the determination of further parameters of airway dynamics. Therefore, we aimed to define the discriminating diagnostic power of the inspiratory and expiratory sWOB (sWOBin, sWOBex), as well as of the inspiratory and expiratory sReff(sReffINand sReffEX), for discriminating different functional phenotypes of chronic obstructive lung diseases.

Methods

Reference equations were obtained from measurement of different databases, incorporating 194 healthy subjects (35 children and 159 adults), and applied to a collective of 294 patients with chronic lung diseases (16 children with asthma, aged 6–16 years, and 278 adults, aged 17–92 years). For all measurements, the same type of plethysmograph was used (Jaeger Würzburg, Germany).

Results

By multilinear modelling, reference equations of sWOBin, sWOBex, sReffINand sReffEXwere derived. Apart from anthropometric indices, additional parameters such as tidal volume (VT), the respiratory drive (P0.1), measured by means of a mouth occlusion pressure measurement 100 ms after inspiration and the mean inspiratory flow (VT/TI) were found to be informative. The statistical approach to define reference equations for parameters of airway dynamics reveals the interrelationship between covariants of the actual breathing pattern and the control of breathing.

Conclusions

We discovered that sWOBin, sWOBex, sReffINand sReffEXare new discriminating target parameters, that differentiate much better between chronic obstructive diseases and their subtypes, especially between chronic obstructive pulmonary disease (COPD) and asthma–COPD overlap (ACO), thus strengthening the concept of precision medicine.
Sequential comparison of two intraductal biliary brush cytology devices for suspected malignant biliary strictures
Authors: Nayar Manu , Oppong Kofi W , Maheshwari Pardeep , Johnson Sarah , Esmaily Shiran , Waller Ruth , Leeds John
Published: March 2024

Background

The diagnostic performance of endoscopic retrograde cholangiopancreatography brush cytology for malignant strictures is modest. A novel larger more abrasive brush may have improved diagnostic performance. We compared the utility of the new biliary brush with a conventional brush.

Methods

The new brush was used in 51 consecutive patients (group 1) referred with a biliary stricture and matched to 102 patients who underwent sampling with a conventional brush (group 2). Demographic data, stricture characteristics, sensitivity, specificity, negative predictive values and positive predictive values were analysed and compared with final diagnosis. Analysis was performed using strict criteria (definite for cancer) and relaxed criteria (suspicious for cancer). All patients had a minimum follow-up of 12 months.

Results

There was no statistically significant difference in the age and sex distribution between the two groups. Malignancy was diagnosed in 74% in both groups. There was no significant difference in sensitivity between the groups using either strict criteria (sensitivity group 1 47.4% vs group 2 52%, p=0.69) or relaxed criteria (sensitivity group 1 71.1% vs group 2 71.2%, p=1.0).

Conclusions

Our data suggest that the novel brush design does not confer improved diagnostic performance in malignant biliary strictures when compared in a robust manner. This highlights the difficulties of intraductal brush sampling and the need to develop newer diagnostic techniques.
Validation of 2D flow MRI for helical and vortical flows
Authors: Mehmood Zia , Assadi Hosamadin , Grafton-Clarke Ciaran , Li Rui , Matthews Gareth , Alabed Samer , Girling Rebekah , Underwood Victoria , Kasmai Bahman , Zhao Xiaodan , Ricci Fabrizio , Zhong Liang , Aung Nay , Petersen Steffen Erhard , Swift Andrew J , Vassiliou Vassilios S , Cavalcante João , Geest Rob J van der , Garg Pankaj
Published: March 2024

Purpose

The main objective of this study was to develop two-dimensional (2D) phase contrast (PC) methods to quantify the helicity and vorticity of blood flow in the aortic root.

Methods

This proof-of-concept study used four-dimensional (4D) flow cardiovascular MR (4D flow CMR) data of five healthy controls, five patients with heart failure with preserved ejection fraction and five patients with aortic stenosis (AS). A PC through-plane generated by 4D flow data was treated as a 2D PC plane and compared with the original 4D flow. Visual assessment of flow vectors was used to assess helicity and vorticity. We quantified flow displacement (FD), systolic flow reversal ratio (sFRR) and rotational angle (RA) using 2D PC.

Results

For visual vortex flow presence near the inner curvature of the ascending aortic root on 4D flow CMR, sFRR demonstrated an area under the curve (AUC) of 0.955, p<0.001. A threshold of >8% for sFRR had a sensitivity of 82% and specificity of 100% for visual vortex presence. In addition, the average late systolic FD, a marker of flow eccentricity, also demonstrated an AUC of 0.909, p<0.001 for visual vortex flow. Manual systolic rotational flow angle change (ΔsRA) demonstrated excellent association with semiautomated ΔsRA (r=0.99, 95% CI 0.9907 to 0.999, p<0.001). In reproducibility testing, average systolic FD (FDsavg) showed a minimal bias at 1.28% with a high intraclass correlation coefficient (ICC=0.92). Similarly, sFRR had a minimal bias of 1.14% with an ICC of 0.96. ΔsRA demonstrated an acceptable bias of 5.72°—and an ICC of 0.99.

Conclusion

2D PC flow imaging can possibly quantify blood flow helicity (ΔRA) and vorticity (FRR). These imaging biomarkers of flow helicity and vorticity demonstrate high reproducibility for clinical adoption.

Trials registration number

NCT05114785.
Application of restorative neurostimulation for chronic mechanical low back pain in an older population with 2-year follow up
Authors: Ardeshiri Ardeshir , Amann Marco , Thomson Simon , Gilligan Christopher J
Published: March 2024

Introduction

Data on the Medicare-aged population show that older patients are major consumers of low back pain (LBP) interventions. An effective approach for patients with mechanical LBP that has been refractory to conservative management is restorative neurostimulation. The efficacy of restorative neurostimulation has been demonstrated in multiple prospective studies, with published follow-up over 4 years, showing a consistent durable effect.

Methods

To further examine the effect of restorative neurostimulation in an older demographic, data from three clinical studies were aggregated: ReActiv8-B prospectively followed 204 patients, ReActiv8-C study prospectively followed 87 patients and ReActiv8-PMCF prospectively followed 42 patients.

Two hundred and sixty-one patients were identified with complete 2-year follow-up and divided into cohorts of equal size based of age quartiles.

At 2 years from device activation, patients in either cohort were classified by change in disability (Oswestry Disability Index (ODI)) or change in pain score(NRS/VAS) and assessed as proportion of patients per group at each time point. Additionally, health-related quality of life (HRQoL) (EQ5D-5L) was longitudinally compared with baseline. Differences in proportions were assessed using χ2and continuous variables by repeated measures analysis of variance.

Results

The oldest quartile (n=65) had a median age of 60 (56–82) years compared with the entire population (n=261) who had a median age of 49 (22–82) years. The completer analysis on patients with 2 years of continuous data showed improvement of a 50% in pain was achieved by 62% and 65% and a 15-point ODI improvement in 48% and 60% in the oldest quartile and entire population, respectively. HRQoL (EuroQol 5-Dimension) improved from baselines of 0.568 and 0.544 to 0.763 and 0.769 in the oldest quartile and entire population respectively. All age quartiles improved statistically and clinically over baseline.

Conclusions

This aggregate analysis of three independent studies provides insight into the performance of restorative neurostimulation in an older population. Patients derived significant and clinically meaningful benefit in disability, pain and HRQoL. When compared with a similarly indicated cohort of younger patients, there were no statistically or clinically significant differences.
The four-loop $$\beta $$-function from vacuum supergraphs and the NSVZ relation for $${{{\mathcal {N}}}}=1$$ SQED regularized by higher derivatives
Authors: Shirokov I. E. , Shirokova V. Yu.
Published: March 2024

In $${{{\mathcal {N}}}}=1$$

N
=
1

SQED with $$N_f$$

N
f

flavors regularized by higher derivatives we obtain the four-loop beta function using a method based on calculating vacuum supergraphs. For this purpose we use a special C++ program which obtain contributions to the $$\beta $$
β
-function from supergraphs without external legs in the form of integrals of double total derivatives. After that the result was compared with the three-loop anomalous dimension calculated earlier. We explicitly check the NSVZ relation in this order.
Prediction on the alpha decay half-lives of 223−243Am isotopes
Authors: Rostami M. Hosseinian , Motevalli S. M. , Amrani N. , Hosseini S. S.
Published: March 2024

We studied the alpha decay half-life of Americium isotopes ([Formula: see text]) with mass numbers ranging from 223 to 243. Our investigation employed the Coulomb and proximity potential model (CPPM), in addition to alternative analytical and semiempirical formulas. The calculations took into account both experimental and theoretical Q-values, as well as the total alpha kinetic energy. We analyzed the behavior of the hindrance factor concerning changes in the mass numbers of parent nuclei within the range of 223–243, and also examined the impact of magic numbers associated with closed shells. To evaluate the accuracy of our findings, we utilized the SemFIS, UNIV, and Royer formulas to make predictions, which were then compared to the existing experimental data.
Supersymmetric behavior of polarized electromagnetic waves in anisotropic media
Authors: Asenjo Felipe A. , Hojman Sergio A. , M. Villegas-Martínez Braulio , Moya-Cessa Héctor M. , Soto-Eguibar Francisco
Published: March 2024

A medium with specific anisotropic refractive indices can induce a supersymmetric behavior in the propagation of polarized electromagnetic waves, in an analog fashion to a quantum mechanical system. The polarizations of the wave are the ones which behave as superpartners from each other. For this to happen, the anisotropy of the medium must be transverse to the direction of propagation of the wave, with different refractive indices along the direction of each polarization, being in this way a biaxial medium. These refractive indices must be complex and follow a very specific relation in order to trigger the supersymetric response of the electromagnetic wave, each of them with spatial dependence on the longitudinal (propagation) direction of the wave. In this form, in these materials, different polarized light can be used to test supersymmetry in an optical fashion.
High-Speed Power Allocation in NOMA System Using FPGA-Based DNN
Authors: Yanamala Rama Muni Reddy , Pullakandam Muralidhar
Published: March 2024

Artificial Intelligence (AI) is rapidly transforming the healthcare, finance and transportation industries. This paper presents a field-programmable gate array (FPGA)-based neural network accelerator (NNA) design for power allocation in downlink nonorthogonal multiple access (NOMA) networks. The proposed hardware accelerator effectively cuts computational costs while delivering performance on par with the highest sum capacity. Numerical results show that this NNA offers a remarkable computational speed increase of up to 99% compared to the conventional exhaustive search method. Furthermore, the deep learning (DL) model achieved high accuracy (0.92 training, 0.93 testing), and the hardware accelerator design for this DL inference model was implemented on the PYNQ-Z2 board-constrained edge device to predict power allocation coefficients in NOMA systems.
FPGA-Based High-Speed Energy-Efficient 32-Bit Fixed-Point MAC Architecture for DSP Application in IoT Edge Computing
Authors: Nagar Mitul Sudhirkumar , Patel Sohan H. , Engineer Pinalkumar
Published: March 2024

Designing high-speed and energy-efficient blocks for image and digital signal processing (DSP) architecture is an evolving research field. This work designs a high-speed and energy-efficient multiply-accumulate (MAC) unit to augment the performance of field-programmable gate array (FPGA)-based accelerators and softcore processors. In this work, three discrete 32-bit fixed-point signed MAC architectures were designed in Verilog and synthesized for the Zynq 7000 ZedBoard to obtain efficient MAC architecture. The ultimate goal of this work is to design a fast and energy-efficient MAC unit that can achieve speed up to the DSP48 block to reduce the latency of IoT edge computing. Energy efficiency was achieved in PPG and partial product addition (PPA) for the proposed Booth radix-4 Dadda (BR4D)-based MAC. At PPG, the width of the partial product (PP) terms was optimized with Bewick’s signed extension to reduce the power consumption. At PPA, the number of PP rows reduces the critical path delay (CPD) with Dadda-based PPA. The proposed BR4D MAC unit offers a reduction in dynamic power, CPD, power-delay product (PDP) and energy-delay product (EDP) by 22%, 9%, 29% and 36%, respectively, compared to standard Booth radix-4 Wallace tree (BR4WT) based MAC. Furthermore, hybrid MACs (BR4WT and BR4D) were compared with the current state-of-the-art (SoA) designs, and it was found that the proposed BR4D MAC is 47% faster compared to the same design in SoA. The proposed BR4D was tested for frequency scaling technique by reducing the frequency in steps of 10 MHz from a maximum usable frequency (MUF) of 64 MHz to 10 MHz to evaluate the performance for low-power applications. Reducing clock frequency by 84% will reduce the power consumption at the same proportion and speed by 38%. Additionally, the proposed design helps to improve the battery life of IoT end nodes with a reduction in energy consumption and EDP by 76% and 61%, respectively.
Design and Implementation of Electronically Controllable Sinusoidal Oscillators Using Commercially Available Current-Feedback Operational Amplifiers with Externally Accessible Compensation Node z
Authors: Pandiev Ivaylo
Published: March 2024

This paper presents the structure and operational principles of high-frequency electronically controllable sinusoidal oscillators employing current-feedback operational amplifiers (CFOAs) with externally accessible compensation node [Formula: see text] as active components. The resonant circuits in the oscillators are connected to the terminal [Formula: see text], and for them in the selective network varactor diodes or varicaps as the variable capacitances are utilized, which are controlled by external DC voltage. Based on an analysis of the proposed circuit configurations, analytical expressions for the characteristic equation in a steady-state mode of operation and formulas for the basic electrical parameters have been obtained. In order to verify the functionality of the proposed electronic circuits and the effectiveness of the derived analytical expressions, an experimental and simulation study of sample electronic circuits with commercially available integrated circuit CFOAs AD844 in the frequency range up to about 10[Formula: see text]MHz is performed. The obtained results for the studied electronic circuits confirm the theoretical studies and hypotheses, and the comparative analysis shows that the maximum value for the relative error does not exceed 10%, which is acceptable considering the tolerances of the technological parameters of the used passive and active elements.
Bistability and Bifurcations of Tumor Dynamics with Immune Escape and the Chimeric Antigen Receptor T-Cell Therapy
Authors: Wang Shaoli , Wang Tengfei , Bai Xiyan , Ji Shaoping , Tian Tianhai
Published: March 2024

Tumor immune escape refers to the inability of the immune system to clear tumor cells, which is one of the major obstacles in designing effective treatment schemes for cancer diseases. Although clinical studies have led to promising treatment outcomes, it is imperative to design theoretical models to investigate the long-term treatment effects. In this paper, we develop a mathematical model to study the interactions among tumor cells, immune escape tumor cells, and T lymphocyte. The chimeric antigen receptor (CAR) T-cell therapy is also described by the mathematical model. Bifurcation analysis shows that there exists backward bifurcation and saddle-node bifurcation when the immune intensity is used as the bifurcation parameter. The proposed model also exhibits bistability when its parameters are located between the saddle-node threshold and backward bifurcation threshold. Sensitivity analysis is performed to illustrate the effects of different mechanisms on the backward bifurcation threshold and basic immune reproduction number. Simulation studies confirm the bifurcation analysis results and predict various types of treatment outcomes using different CAR T-cell therapy strengths. Analysis and simulation results show that the immune intensity can be used to control the tumor size, but it has no effect on the control of the immune escape tumor size. The introduction of the CAR T-cell therapy will reduce the immune escape tumor size and the treatment effect depends on the CAR T-cell therapy strength.
Impact of Fear and Group Defense on the Dynamics of a Predator–Prey System
Authors: Pal Soumitra , Karmakar Sarbari , Pal Saheb , Pal Nikhil , Misra A. K. , Chattopadhyay Joydev
Published: March 2024

To reduce the chance of predation, many prey species adopt group defense mechanisms. While it is commonly believed that such defense mechanisms lead to positive feedback on prey density, a closer observation reveals that it may impact the growth rate of species. This is because individuals invest more time and effort in defense rather than reproductive activities. In this study, we delve into a predator–prey system where predator-induced fear influences the birth rate of prey, and the prey species exhibit group defense mechanism. We adopt a nonmonotonic functional response to govern the predator–prey interaction, which effectively captures the group defense mechanism. We present a detailed mathematical analysis, encompassing the determination of feasible equilibria and their stability conditions. Through the analytical approach, we demonstrate the occurrence of Hopf and Bogdanov–Takens (BT) bifurcations. We observe two distinct types of bistabilities in the system: one between interior and predator-free equilibria, and another between limit cycle and predator-free equilibrium. Our findings reveal that the parameters associated with group defense and predator-induced fear play significant roles in the survival and extinction of populations.
Optimal and Poor Synchronizations of Directionally Coupled Phase-Coherent Chaotic Oscillators
Authors: Lei Yong , Xu Xin-Jian , Wang Xiaofan
Published: March 2024

We study directionally coupled phase-coherent chaotic oscillators in complex networks. We introduce an adjusted Lyapunov function that incorporates the frequencies of the oscillators and the interaction structure. Using the well-known Rössler system as an example, we address two optimization problems: frequency allocation and network design. Through numerical experiments, we demonstrate that the systematic synchrony can be effectively enhanced or inhibited by minimizing or maximizing the objective function, respectively. We then delve into the relationship between the structural and dynamical properties that lead to optimal synchronization. Interestingly, we observe a positive correlation between nodal in-degrees and frequency magnitudes, indicating that nodes with higher in-degrees tend to exhibit larger frequency magnitudes. On the other hand, we also find a negative correlation between nodal frequency and adjacent in-frequencies, suggesting that nodes with higher frequencies tend to be surrounded by nodes with lower frequency values. Finally, we explore the connections between degree correlations and optimal synchronization. We find that when minimizing the objective function, the presence of degree correlations always inhibits the systematic synchrony for frequency allocation, while the act of network design causes the correlations to become negative.
On–Off Intermittency and Long-Term Reactivity in a Host–Parasitoid Model with a Deterministic Driver
Authors: Diele Fasma , Lacitignola Deborah , Monti Angela
Published: March 2024

Bursting behaviors, driven by environmental variability, can substantially influence ecosystem services and functions and have the potential to cause abrupt population breakouts in host–parasitoid systems. We explore the impact of environment on the host–parasitoid interaction by investigating separately the effect of grazing-dependent habitat variation on the host density and the effect of environmental fluctuations on the average host population growth rate. We hence focus on the discrete host–parasitoid Beddington–Free–Lawton model and show that a more comprehensive mathematical study of the dynamics behind the onset of on–off intermittency in host–parasitoid systems may be achieved by considering a deterministic, chaotic system that represents the dynamics of the environment. To this aim, some of the key model parameters are allowed to vary in time according to an evolution law that can exhibit chaotic behavior. Fixed points and stability properties of the resulting 3D nonlinear discrete dynamical system are investigated and on–off intermittency is found to emerge strictly above the blowout bifurcation threshold. We show, however, that, in some cases, this phenomenon can also emerge in the sub-threshold. We hence introduce the novel concept of long-term reactivity and show that it can be considered as a necessary condition for the onset of on–off intermittency. Investigations in the time-dependent regimes and kurtosis maps are provided to support the above results. Our study also suggests how important it is to carefully monitor environmental variability caused by random fluctuations in natural factors or by anthropogenic disturbances in order to minimize its effects on throphic interactions and protect the potential function of parasitoids as biological control agents.
Optimal Scheme Models with Two Kinds of Errors
Authors: Naruse Kenichiro , Nakagawa Toshio
Published: March 2024

In this paper, we propose stochastic scheme models with two kinds of errors for a computer system. A highly reliable computer system needs greatly to be backed up successfully in case of computer system crashes due to hardware failures and malicious software infections. We aim to determine appropriate backup times in computer processing of constant and random tasks. For this purpose, the trade-off between backup times and data losses due to errors is considered. The total execution times until the computing processing completes are obtained, and optimal backup policies to minimize them are derived analytically. Furthermore, we take up extended models of random tasks with [Formula: see text] sub-tasks and analyze them.
Vibration Suppression of Piecewise-Linear Stiffness NES System Under Random Excitation
Authors: Wang Jun , Kan Zi Jian , Zhang Yun Hao , Zhang Jian Chao
Published: March 2024

Nonlinear energy sinks (NESs) are critically important for structural vibration suppression. They can absorb vibrational energy across a broad frequency spectrum, possess strong robustness, and have a relatively small mass. This study addresses the vibration suppression in a piecewise linear stiffness NES system under random excitation. Initially, a theoretical model of the piecewise linear stiffness NES system is developed. The piecewise linear stiffness function is approximated using Legendre polynomial approximation. Following this, the steady-state Fokker–Planck–Kolmogorov (FPK) equation of the system is formulated via the Generalized Harmonic Function Method. The FPK equation is solved using the fourth-order central difference method, and the effectiveness of this approach is validated by comparing the FDM results with numerical simulations. Lastly, the influence of varying system parameters on the stability of the piecewise linear stiffness NES system is analyzed.
Experiment, Simulation, and Theoretical Investigation of a New Type of Interlayer Connections Enhanced Viscoelastic Damper
Authors: Xu Yeshou , Xu Zhao-Dong , Hu Hao , Guo Ying-Qing , Huang Xing-Huai , Zhang Zhong-Wen , Zhang Tian , Xu Chao
Published: March 2024

A conventional plate-type viscoelastic damper (VED) can easily crack at the interfaces of steel plates and viscoelastic components. In the present work, grooved VEDs, which are a new type of interfacial enhanced VEDs with interfacial grooves, are designed to improve the damping capacity and anti-cracking ability of conventional dampers. The dynamic property experiments of the normal and grooved VEDs are carried out and the interfacial cracking failure of the VEDs are simulated and analyzed by using bilayer cohesive constitutive model with ABAQUS. The grooved VED exhibits excellent dynamic performance and energy dissipation capacity at different temperatures, frequencies, and displacement amplitudes. Experiments and finite element analysis prove that the energy dissipation performance and interfacial bonding strength of the grooved VED are effectively improved. A modified fractional standard linear solid model, in which the Payne effect and temperature–frequency equivalent principle are combined and implemented, is proposed. This model can portray the influence of the excitation displacement, surrounding temperature and external excitation frequency on damper properties at the same time. The fillers and molecular chains affections at micro- and meso-scale are also taken into account. The model’s numerical calculations and experimental results comparisons present that the modified fractional standard linear solid model has sufficient accuracy and performs well in depicting the dynamic properties of the interfacial grooved VED. The errors between the theoretical and experimental values of [Formula: see text] and [Formula: see text] for the grooved VED are mostly within 20% at representative conditions. The interfacial groove structures can well enhance the interfacial bonding and improve the service life of conventional dampers. The modified fractional standard linear solid model is simple and has clear physical meanings for each macro/micro parameters, making it convenient for application in engineering practice. The present research is of great significance in improving the work stability of VEDs and promoting the application of viscoelastic damping technology.
Out-of-Plane Instability and Vibrations of a Flexible Circular Arch Under a Moving Load
Authors: Zhao Xingwei , van der Heijden G. H. M.
Published: March 2024

Flexible lightweight arched structures are finding increasing use as components in smart engineering applications. Such structures are prone to various types of instability under moving transverse loads. Here, we study deformation and vibration of a hinged circular arch under a uniformly moving point load using geometrically-exact rod theory to allow for large pre- and post-buckling deformations. We first consider the quasi-statics problem, without inertia. We find that for arches with relatively large opening angle ([Formula: see text]160[Formula: see text]) a sufficiently large traversing load will induce an out-of-plane flopping instability, instead of the in-plane collapse (snap-through) that dominates failure of arches with smaller opening angle. In a subsequent dynamics study, with full account of inertia, we then explore the effect of the speed of the load on this lateral buckling. We find speed to have a delaying (or even suppressing) effect on the onset of three-dimensional bending–torsional vibrations and instability. Based on numerical computations we propose a power law describing this effect. Our results highlight the role of inertia in the onset of elastic instability.
Optimization Research of Bird Detection Algorithm Based on YOLO in Deep Learning Environment
Authors: Chen Xi , Zhang Zhenyu
Published: March 2024

Recent environmental degradation has led to an unparalleled decline in wild bird habitats, resulting in a worldwide decrease in bird populations. To prevent extinction, it is vital to implement protective measures. One effective solution could be the application of deep learning techniques to identify bird species and habitats, which would prove useful for bird enthusiasts and rescuers. Therefore, a dataset of 20 globally prized bird species has been collated and analyzed. The Bird-YOLO algorithm precisely identifies avian creatures by combining neural architecture search and knowledge distillation. To diminish noise interference, preprocessing of images and dimension clustering of prior boxes are carried out prior to the training. The experiments show that the Bird-YOLO algorithm attains an 88.23% bird recognition rate, with a frames per second (FPS) of 47.
HLNBO: Hybrid Leader Namib Beetle Optimization Algorithm-Based LeNet for Classification of Parkinson’s Disease
Authors: Sharanyaa S , Sambath M
Published: March 2024

Parkinson’s disease (PD) occurs while particular cells of the brain are not able to create dopamine that is required for regulating the count of non-motor as well as motor activities of the human body. One of the earlier symptoms of PD is voice disorder and current research shows that approximately about 90% of patients affected by PD suffer from vocal disorders. Hence, it is vital to extract pathology information in voice signals for detecting PD, which motivates to devise the approaches for feature selection and classification of PD. Here, an effectual technique is devised for the classification of PD, which is termed as Hybrid Leader Namib beetle optimization algorithm-based LeNet (HLNBO-based LeNet). The considered input voice signal is subjected to pre-processing of the signal phase. The pre-processing is carried out to remove the noises and calamities using a Gaussian filter whereas in the feature extraction phase, several features are extracted. The extracted features are given to the feature selection stage that is performed employing the Hybrid Leader Squirrel Search Water algorithm (HLSSWA), which is the combination of Hybrid Leader-Based Optimization (HLBO), Squirrel Search Algorithm (SSA), and Water Cycle Algorithm (WCA) by considering the Canberra distance as the fitness function. The PD classification is conducted using LeNet, which is tuned by the designed HLNBO. Additionally, HLNBO is newly presented by merging HLBO and the Namib beetle optimization algorithm (NBO). Thus, the new technique achieved maximal values of accuracy, TPR, and TNR of about 0.949, 0.957, and 0.936, respectively.
iCEED: Integrated customized extraction of enzyme data
Authors: Karbhal Rajiv , Sawant Sangeeta , Kulkarni-Kale Urmila
Published: March 2024

Enzymes catalyze diverse biochemical reactions and are building blocks of cellular and metabolic pathways. Data and metadata of enzymes are distributed across databases and are archived in various formats. The enzyme databases provide utilities for efficient searches and downloading enzyme records in batch mode but do not support organism-specific extraction of subsets of data. Users are required to write scripts for parsing entries for customized data extraction prior to downstream analysis. Integrated Customized Extraction of Enzyme Data (iCEED) has been developed to provide organism-specific customized data extraction utilities for seven commonly used enzyme databases and brings these resources under an integrated portal. iCEED provides dropdown menus and search boxes using typehead utility for submission of queries as well as enzyme class-based browsing utility. A utility to facilitate mapping and visualization of functionally important features on the three-dimensional (3D) structures of enzymes is integrated. The customized data extraction utilities provided in iCEED are expected to be useful for biochemists, biotechnologists, computational biologists, and life science researchers to build curated datasets of their choice through an easy to navigate web-based interface. The integrated feature visualization system is useful for a fine-grained understanding of the enzyme structure–function relationship. Desired subsets of data, extracted and curated using iCEED can be subsequently used for downstream processing, analyses, and knowledge discovery. iCEED can also be used for training and teaching purposes.
Quantum key distribution with relay-assisted scheme over long atmospheric channels
Authors: Ni Ju , Mao Shuxia , Xiao Hailin , Chronopoulos Anthony Theodore
Published: March 2024

A relay-assisted scheme for quantum key distribution (QKD) over long atmospheric channels is proposed. In this scheme, a polarization orbital-angular-moment with measurement-device-independent (POAM-MDI) QKD for quantum relay is designed to both reconstruct the turbulence-degraded qubits and redirect the qubits to the next relay or to Bob who performs detection randomization. The proposed scheme will neither be time-consuming nor lead to unstable or even intermittent in volatile environments. Theoretical and numerical results show that the proposed relay-assisted scheme outperforms the conventional direct transmission over long atmospheric channels.
Photoluminescence of Monolayer WSe2 Enhanced by the Exciton Funnel Effect and the Interfacial Carrier Tunneling Effect When Integrated with 3D Si Wrinkled Structures
Authors: Lv Yanhui , Wu Gang , Chang Guo-En , Coileáin Cormac Ó , Hung Kuan-Ming , Arora Sunil K. , Chang Ching-Ray , Cheng H. H. , Wu Han-Chun
Published: March 2024

Quantum optics and photonic quantum-information technologies require emitters that have good stability and brightness, coupled with fabrication scalability and on-chip integrability. Most quantized emitters are presently based on 1D and 3D sources. Recently, monolayer transition metal dichalcogenides (TMDCs) hosting spatially localized excitons with narrow linewidths have garnered great interest. Advantages such as large binding energies and long room-temperature lifetimes of intralayer excitons suggest that TMDCs are promising candidates for use in optical devices. Here, we propose an emitter based on a 2D WSe2 semiconductor monolayer integrated with a periodic 3D Si-based wrinkled pattern. Carriers confined within the wrinkled pattern can be electrically and optically pumped, and funneled, to boost emission from the 2D WSe2 layer. This in turn acts as a monochromated quantum light source for the Si or any Si-based quantum optic and photonic information technologies. The brightness of the emission is enhanced by a factor greater than 40 compared with monolayer WSe2 on conventional flat SiGe. Moreover, these monolayer 2D/3D semiconductor composite heterostructures are fully scalable and promisingly efficient chip-integrated emitters.
The Changing Dynamics of Japan–India Cooperation: A Case of ‘Rule-Based Order’ in Indo-Pacific
Authors: SUBBA NARESH
Published: March 2024

Japan and India are the two oldest and largest democracies in Asia. Since the inception of their diplomatic relations in 1952, the two countries have maintained a cordial relationship. They remain aloof during the Cold War period due to their ideological differences. After that, India following the economic liberalization followed by the “Look East” policy in the post-Cold War period had a positive impact on bilateral relations. This took a sudden gap due to India’s second Pokhran nuclear test in 1998 followed by Japanese economic sanctions. However, the relations normalized soon when Mori visited India along with other South Asian nations in 2000. The bilateral relations further improved when the two countries signed the “strategic orientation of Japan-India global partnership” during Koizumi’s visit in 2005. Since then, the two countries have been engaging in different aspects of strategic partnership, and a peaceful and stable Indo-Pacific along with the “rule-based order” has always been their priority. Thus, different scholars and statesmen from both countries started the discussion on building a new architecture of ‘rule-based order’ in the Indo-Pacific. To that end, Japan and India have continuously engaged themselves in bilateral and multilateral dialogue such as G4, Shangri-La Dialogue and Quad. Thus, this paper will try to see how far the two countries can persuade the international community to push the concept of “rule-based order” in the Indo-Pacific.