bluuebunny/crossref_metadata_2025 huggingface dataset:
Neural network learning and Quantum Gravity
Authors: Lanza Stefano
Published: July 2024

Abstract

The landscape of low-energy effective field theories stemming from string theory is too vast for a systematic exploration. However, the meadows of the string landscape may be fertile ground for the application of machine learning techniques. Employing neural network learning may allow for inferring novel, undiscovered properties that consistent theories in the landscape should possess, or checking conjectural statements about alleged characteristics thereof. The aim of this work is to describe to what extent the string landscape can be explored with neural network-based learning. Our analysis is motivated by recent studies that show that the string landscape is characterized by finiteness properties, emerging from its underlying tame, o-minimal structures. Indeed, employing these results, we illustrate that any low-energy effective theory of string theory is endowed with certain statistical learnability properties. Consequently, several local learning problems therein formulated, including interpolations and multi-class classification problems, can be concretely addressed with machine learning, delivering results with sufficiently high accuracy.
Human post-implantation blastocyst-like characteristics of Muse cells isolated from human umbilical cord
Authors: Kushida Yoshihiro , Oguma Yo , Abe Kana , Deguchi Taichi , Barbera Federico Girolamo , Nishimura Noriyuki , Fujioka Kazumichi , Iwatani Sota , Dezawa Mari
Published: July 2024

Muse cells, identified as cells positive for the pluripotent surface marker SSEA-3, are pluripotent-like endogenous stem cells located in the bone marrow (BM), peripheral blood, and organ connective tissues. The detailed characteristics of SSEA-3(+) cells in extraembryonic tissue, however, are unknown. Here, we demonstrated that similar to human-adult tissue-Muse cells collected from the BM, adipose tissue, and dermis as SSEA-3(+), human-umbilical cord (UC)-SSEA-3(+) cells express pluripotency markers, differentiate into triploblastic-lineage cells at a single cell level, migrate to damaged tissue, and exhibit low telomerase activity and non-tumorigenicity. Notably, ~ 20% of human-UC-SSEA-3(+) cells were negative for X-inactive specific transcript (XIST), a naïve pluripotent stem cell characteristic, whereas all human adult tissue-Muse cells are XIST-positive. Single-cell RNA sequencing revealed that the gene expression profile of human-UC-SSEA-3(+) cells was more similar to that of human post-implantation blastocysts than human-adult tissue-Muse cells. The DNA methylation level showed the same trend, and notably, the methylation levels in genes particularly related to differentiation were lower in human-UC-SSEA-3(+) cells than in human-adult tissue-Muse cells. Furthermore, human-UC-SSEA-3(+) cells newly express markers specific to extraembryonic-, germline-, and hematopoietic-lineages after differentiation induction in vitro whereas human-adult tissue-Muse cells respond only partially to the induction. Among various stem/progenitor cells in living bodies, those that exhibit properties similar to post-implantation blastocysts in a naïve state have not yet been found in humans. Easily accessible human-UC-SSEA-3(+) cells may be a valuable tool for studying early-stage human development and human reproductive medicine.
A joint model of longitudinal pharmacokinetic and time-to-event data to study exposure–response relationships: a proof-of-concept study with alectinib
Authors: Lin Lishi , van der Noort Vincent , Steeghs Neeltje , Ruiter Gerrina , Beijnen Jos H. , Huitema Alwin D. R.
Published: July 2024

Purpose

In exposure–response analyses of oral targeted anticancer agents, longitudinal plasma trough concentrations are often aggregated into a single value even though plasma trough concentrations can vary over time due to dose adaptations, for example. The aim of this study was to compare joint models to conventional exposure–response analyses methods with the application of alectinib as proof-of-concept.

Methods

Joint models combine longitudinal pharmacokinetic data and progression-free survival data to infer the dependency and association between the two datatypes. The results from the best joint model and the standard and time-dependent cox proportional hazards models were compared. To normalize the data, alectinib trough concentrations were normalized using a sigmoidal transformation to transformed trough concentrations (TTC) before entering the models.

Results

No statistically significant exposure–response relationship was observed in the different Cox models. In contrast, the joint model with the current value of TTC in combination with the average TTC over time did show an exposure–response relationship for alectinib. A one unit increase in the average TTC corresponded to an 11% reduction in progression (HR, 0.891; 95% confidence interval, 0.805–0.988).

Conclusion

Joint models are able to give insights in the association structure between plasma trough concentrations and survival outcomes that would otherwise not be possible using Cox models. Therefore, joint models should be used more often in exposure–response analyses of oral targeted anticancer agents.
On the Connected Blocks Polytope
Authors: Bruckamp Justus , Chimani Markus , Juhnke Martina
Published: July 2024

In this paper, we study the connected blocks polytope, which, apart from its own merits, can be seen as the generalization of certain connectivity based or Eulerian subgraph polytopes. We provide a complete facet description of this polytope, characterize its edges and show that it is Hirsch. We also show that connected blocks polytopes admit a regular unimodular triangulation by constructing a squarefree Gröbner basis. In addition, we prove that the polytope is Gorenstein of index 2 and that its $$h^*$$

h
∗

-vector is unimodal.
On Pisier Type Theorems
Authors: Nešetřil Jaroslav , Rödl Vojtěch , Sales Marcelo
Published: July 2024

For any integer $$h\geqslant 2$$

h
⩾
2

, a set of integers $$B=\{b_i\}_{i\in I}$$

B
=

{

b
i

}

i
∈
I

is a $$B_h$$

B
h

-set if all h-sums $$b_{i_1}+\ldots +b_{i_h}$$

b

i
1

+
…
+

b

i
h

with $$i_1<\ldots <i_h$$

i
1

<
…
<

i
h

are distinct. Answering a question of Alon and Erdős [2], for every $$h\geqslant 2$$

h
⩾
2

we construct a set of integers X which is not a union of finitely many $$B_h$$

B
h

-sets, yet any finite subset $$Y\subseteq X$$

Y
⊆
X

contains an $$B_h$$

B
h

-set Z with $$|Z|\geqslant \varepsilon |Y|$$

|
Z
|
⩾
ε
|
Y
|

, where $$\varepsilon :=\varepsilon (h)$$

ε
:
=
ε
(
h
)

. We also discuss questions related to a problem of Pisier about the existence of a set A with similar properties when replacing $$B_h$$

B
h

-sets by the requirement that all finite sums $$\sum _{j\in J}b_j$$

∑

j
∈
J

b
j

are distinct.
Validity of Ultra-Short-Term Heart Rate Variability Derived from Femoral Arterial Pulse Waveform in a British Military Cohort
Authors: Maqsood Rabeea , Schofield Susie , Bennett Alexander N. , Khattab Ahmed , Bull Anthony M. J. , Fear Nicola T. , Boos Christopher J.
Published: July 2024

Various non-electrocardiogram (ECG) based methods are considered reliable sources of heart rate variability (HRV) measurement. However, the ultra-short recording of a femoral arterial waveform has never been validated against the gold-standard ECG-based 300s HRV and was the aim of this study.

A validity study was conducted using a sample from the first follow-up of the longitudinal ADVANCE study UK. The participants were adult servicemen (n = 100); similar in age, rank, and deployment period (Afghanistan 2003–2014). The femoral arterial waveforms (14s) from the pulse wave velocity (PWV) assessment, and ECG (300s) were recorded at rest in the supine position using the Vicorder™ and Bittium Faros™ devices, respectively, in the same session. HRV analysis was performed using Kubios Premium. Resting heart rate (HR) and root mean square of successive differences (RMSSD) were reported. The Bland-Altman %plots were constructed to explore the PWV-ECG agreement in HRV measurement. A further exploratory analysis was conducted across methods and durations.

The participants’ mean age was 38.0 ± 5.3 years. Both PWV-derived HR (r = 0.85) and RMSSD (rs=0.84) showed strong correlations with their 300s-ECG counterparts (p < 0.001). Mean HR was significantly higher with ECG than PWV (mean bias: -12.71 ± 7.73%, 95%CI: -14.25%, -11.18%). In contrast, the difference in RMSSD between the two methods was non-significant [mean bias: -2.90 ± 37.82% (95%CI: -10.40%, 4.60%)] indicating good agreement. An exploratory analysis of 14s ECG-vs-300s ECG measurement revealed strong agreement in both RMSSD and HR.

The 14s PWV-derived RMSSD strongly agrees with the gold-standard (300s-ECG-based) RMSSD at rest. Conversely, HR appears method sensitive.
Weak convergence of tamed exponential integrators for stochastic differential equations
Authors: Erdoğan Utku , Lord Gabriel J.
Published: July 2024

We prove weak convergence of order one for a class of exponential based integrators for SDEs with non-globally Lipschitz drift. Our analysis covers tamed versions of Geometric Brownian Motion (GBM) based methods as well as the standard exponential schemes. The numerical performance of both the GBM and exponential tamed methods through four different multi-level Monte Carlo techniques are compared. We observe that for linear noise the standard exponential tamed method requires severe restrictions on the step size unlike the GBM tamed method.
The significance of the apelinergic system in doxorubicin-induced cardiotoxicity
Authors: Matusik Katarzyna , Kamińska Katarzyna , Sobiborowicz-Sadowska Aleksandra , Borzuta Hubert , Buczma Kasper , Cudnoch-Jędrzejewska Agnieszka
Published: July 2024

Cancer is the leading cause of death worldwide, and the number of cancer-related deaths is expected to increase. Common types of cancer include skin, breast, lung, prostate, and colorectal cancers. While clinical research has improved cancer therapies, these treatments often come with significant side effects such as chronic fatigue, hair loss, and nausea. In addition, cancer treatments can cause long-term cardiovascular complications. Doxorubicin (DOX) therapy is one example, which can lead to decreased left ventricle (LV) echocardiography (ECHO) parameters, increased oxidative stress in cellular level, and even cardiac fibrosis. The apelinergic system, specifically apelin and its receptor, together, has shown properties that could potentially protect the heart and mitigate the damages caused by DOX anti-cancer treatment. Studies have suggested that stimulating the apelinergic system may have therapeutic benefits for heart damage induced by DOX. Further research in chronic preclinical models is needed to confirm this hypothesis and understand the mechanism of action for the apelinergic system. This review aims to collect and present data on the effects of the apelinergic system on doxorubicin-induced cardiotoxicity.
Gradient-Based Monte Carlo Methods for Relaxation Approximations of Hyperbolic Conservation Laws
Authors: Bertaglia Giulia , Pareschi Lorenzo , Caflisch Russel E.
Published: July 2024

Particle methods based on evolving the spatial derivatives of the solution were originally introduced to simulate reaction-diffusion processes, inspired by vortex methods for the Navier–Stokes equations. Such methods, referred to as gradient random walk methods, were extensively studied in the ’90s and have several interesting features, such as being grid-free, automatically adapting to the solution by concentrating elements where the gradient is large, and significantly reducing the variance of the standard random walk approach. In this work, we revive these ideas by showing how to generalize the approach to a larger class of partial differential equations, including hyperbolic systems of conservation laws. To achieve this goal, we first extend the classical Monte Carlo method to relaxation approximation of systems of conservation laws, and subsequently consider a novel particle dynamics based on the spatial derivatives of the solution. The methodology, combined with asymptotic-preserving splitting discretization, yields a way to construct a new class of gradient-based Monte Carlo methods for hyperbolic systems of conservation laws. Several results in one spatial dimension for scalar equations and systems of conservation laws show that the new methods are very promising and yield remarkable improvements compared to standard Monte Carlo approaches, either in terms of variance reduction as well as in describing the shock structure.
Studies for mutual solubility of TODGA and water at 298.15 K and 0.1 MPa
Authors: Kumar Shekhar
Published: July 2024

Tetra-octyl diglycolic amide (TODGA) is an emerging novel solvent for flowsheet demonstrations of novel nuclear extraction processes used in nuclear fuel cycle and associated waste management activities. Mutual solubilities of extractant and water are important process parameters for modeling the mass transfer as these are vital for phase volume change calculations. Experimental results for aqueous solubility of TODGA were reported based on SCWO assisted persulphate based TOC measurements. Experimental results for solubility of water in the binary solutions of TODGA and n-dodecane were reported based on KF titration. Reported values were correlated by empirical equations.
Physiologic and anatomic determinants of hyoid motion during drug-induced sleep endoscopy
Authors: Parekh Manan H. , Thuler Eric , Triantafillou Vasiliki , Seay Everett , Sehgal Chandra , Schultz Susan , Keenan Brendan T. , Schwartz Alan R. , Dedhia Raj C.
Published: July 2024

Purpose

To examine factors accounting for differences in hyoid motion during obstructive breathing events amongst obstructive sleep apnea (OSA) patients.

Methods

This was a prospective cohort study from June 2022 to October 2022. Patients with OSA undergoing evaluation for PAP alternative therapies with drug-induced sleep endoscopy with positive airway pressure titration (DISE-PAP). All patients underwent DISE-PAP and concurrent hyoid-focused ultrasound. DISE-PAP enabled measurement of airway physiology (flow, respiratory effort) and airway collapsibility (pharyngeal opening pressure, PhOP). Hyoid-ultrasound enabled hyoid bone movement during obstructive breathing. Respiratory effort was measured using a retro-epiglottic pressure-sensitive catheter. Hyoid position was measured using a standardized, awake, CT protocol. Regression analyses adjusted for age, race, sex, and BMI were performed to associate indices of respiratory effort and CT data with hyoid motion.

Results

On average, the 26 patients in this cohort were older (63.9 ± 10.5 years), male (69%), overweight (29.6 ± 3.99 kg/m2), and with moderate-to-severe OSA (26.8 ± 10.4 events/hour). Greater respiratory effort was associated with increased hyoid motion (β [95% CI] = 0.034 [0.016,0.052], standardized β = 0.261,p = 0.0003). Higher hyoid position was associated with greater hyoid displacement (β [95% CI] = -0.20 [-0.38,-0.01], Standardized β = -0.57, p = 0.036).

Conclusion

Our data demonstrate that greater respiratory effort, higher hyoid position, and higher airway collapsibility, but not airflow, are associated with greater hyoid motion during obstructive breathing in DISE. These findings suggest that downward hyoid movement represents a compensatory response to upper airway obstruction. Further studies should investigate the vectors of hyoid motion to better understand its role in sleep-related airway collapse.
Fuel Subsidies in Ecuador: A Computable General Equilibrium Model for Targeting Evaluation
Authors: Montenegro-Casa Cristhian , Ramírez-Álvarez José
Published: July 2024

Fuel subsidies have been an enduring policy in Ecuador’s political and economic history. Given their lack of targeting and high opportunity cost, they have been amply criticized. As of 2017, the Ecuadorian government started a budget consolidation plan that so far has involved seven reforms to subsidies policy in less than seven years. In late 2019, in response to social unrest motivated by a temporal elimination of fuel subsidies, the government pledged to study new targeting mechanisms for this policy to mitigate the impact on the most vulnerable sectors. This work seeks to contribute to that effort by evaluating the macroeconomic effects of these subsidies and serving as a guideline for targeting. A computable general equilibrium model is used to assess counterfactual scenarios. The results suggest that by implementing progressiveness and productive linkage criteria, targeting household final consumption and intermediate consumption is a feasible way to reduce the reforms’ negative effects.
A Sugar Coating for Arrokoth
Authors: O’Callaghan Jonathan
Published: July 2024

A Kuiper Belt object might contain ribose and glucose on its surface—the same elements that could have seeded life on Earth.
The Fluvial Battering Ram: Collisional Experiments Reveal the Importance of Particle Impact Energies on Bedrock Erosional Efficiency
Authors: Masteller C. C. , Chandler H. , Bower J.
Published: July 2024

The battering of bedrock by bedload collisions is the primary mechanism by which bedrock rivers erode and landscapes evolve. The energy imparted via impacts acts to detach bedrock via the growth and intersection of surface fractures. We present impact experiments designed to test the influence of particle impact energy on bedrock erosion rates. We found that erosional efficiency increased with increasing impact energy. Notably, these increases in efficiency are not captured by a widely‐used mechanistic bedrock erosion model. Observed increases in erosional efficiency were linked with enhanced elastic energy dissipation captured by differences in the coefficient of restitution. We suggest that this increase in energy dissipation is indicative of enhanced crack extension for high velocity impacts. Our experiments indicate a clear energy‐dependence for bedrock detachment processes that is not yet captured by bedrock incision models but may be integrated into long‐term erosion rates and landscape evolution.
Developing an eyeball positioning method in the eye orbit for craniofacial identification in Korean population
Authors: Ryu Joon Yeol , Park Yeon-Kyung , Park Ji-Hwan , Seo Jeong Uk , Roh Byung-Yoon , Kim Eui-Joo , Choi Chang-Un , Koh Kyoung Min , Lee Won-Joon
Published: July 2024

We analysed the skulls and faces of Korean subjects using anthropometric methods to understand the anatomical characteristics of the eyeball and eye orbit region of Korean population and to determine the correlations between the hard and soft tissues around the eyeball and eye orbit region. In total, 82 sections in the region were measured to determine the correlations; among them, 34 showed significant differences by sex, and 6 showed significant differences by age. As the distance from the centre of the eye lens to the eye orbit is calculated as a ratio, we determined that the centre of the eye lens is located relatively on the lateral and superior position in each eye orbit in front view. Fourteen sections that could be used for craniofacial reconstruction/approximation in men and women were selected. Regression equations were derived according to the correlation of each section, and their reliabilities were verified by out of sample validation tests. Therefore, our results increase the accuracy of eyeball position determination, which would be useful for more efficient craniofacial reconstruction/approximation of the Korean population and should improve the efficiency of facial recognition.
Study on the inhibitory activity and mechanism of Mentha haplocalyx essential oil nanoemulsion against Fusarium oxysporum growth
Authors: Liao Hongxin , Wen Jinrui , Nie Hongyan , Ling Cuiqiong , Zhang Liyan , Xu Furong , Dong Xian
Published: July 2024

Mentha haplocalyx essential oil (MEO) has demonstrated inhibitory effects on Fusarium oxysporum. Despite its environmentally friendly properties as a natural product, the limited water solubility of MEO restricts its practical application in the field. The use of nanoemulsion can improve bioavailability and provide an eco-friendly approach to prevent and control Panax notoginseng root rot. In this study, Tween 80 and anhydrous ethanol (at a mass ratio of 3) were selected as carriers, and the ultrasonic method was utilized to produce a nanoemulsion of MEO (MNEO) with an average particle size of 26.07 nm. Compared to MTEO (MEO dissolved in an aqueous solution of 2% DMSO and 0.1% Tween 80), MNEO exhibited superior inhibition against F. oxysporum in terms of spore germination and hyphal growth. Transcriptomics and metabolomics results revealed that after MNEO treatment, the expression levels of certain genes related to glycolysis/gluconeogenesis, starch and sucrose metabolism were significantly suppressed along with the accumulation of metabolites, leading to energy metabolism disorder and growth stagnation in F. oxysporum. In contrast, the inhibitory effect from MTEO treatment was less pronounced. Furthermore, MNEO also demonstrated inhibition on meiosis, ribosome function, and ribosome biogenesis in F. oxysporum growth process. These findings suggest that MNEO possesses enhanced stability and antifungal activity, which effectively hinders F. oxysporum through inducing energy metabolism disorder, meiotic stagnation, as well as ribosome dysfunction, thus indicating its potential for development as a green pesticide for prevention and control P. notoginseng root rot caused by F.oxyosporum.
Three-pressure prediction method of jointing well-seismic data in JT1 well area of Sichuan Basin in China
Authors: Zhao Hu , Zhang Zhong-wei , Zhao Rong-rong , Chen Wei , He Chang-long
Published: July 2024

With the high yield of many wells represented by Well JT1 in the Maokou Formation, has catalyzed a surge in exploration activities along the platform margin facies of the Maokou Formation in central Sichuan and further showed the significant exploration potential of the Maokou Formation in the northern slope. However, the fracture cave body of the Maokou Formation exhibits a high degree of development, strong longitudinal and horizontal heterogeneity, large formation pressure differences, and drilling events such as gas kicks and lost circulation occur frequently, which seriously affects the efficient implementation of drilling. Understanding the spatial distribution of the three-pressure in the formation can help better deal with and solve the above problems. Therefore, in order to help the safe, high-quality and rapid drilling of the Maokou Formation in the study area, and enhance the efficiency of oil and gas development, this paper explores the research on the prediction method of the three-pressure of jointing well-seismic data based on the geomechanical experimental data and the actual drilling data. In the process of prediction of pore pressure, this study found that the pore pressure and formation velocity in the study area have an exponential relationship. In order to enhance the applicability of the Filippone’s method in the study area and improve the prediction accuracy of pore pressure, the linear relationship between pore pressure and formation velocity in the Filippone’s method is modified to an exponential relationship, and a pore pressure prediction model suitable for the work area was established. Based on the Mohr–Coulomb criterion and Huang's model, the prediction models of collapse pressure and fracture pressure applicable to the study area were established, respectively. Then, the elastic parameters were obtained through pre-stack inversion, and the three-pressure bodies were calculated based on the elastic parameter bodies. The results indicate that: (1) The three-pressure prediction method of the jointing well-seismic data in this paper can predict the formation's longitudinal and transverse pressure anomaly zones in advance. (2) The Maokou Formation in the study area is characterized by abnormally high pressure, to balance the pressure of the high-ground formation, high-density drilling fluid is necessary. (3) The prediction results of three-pressure in this paper are highly consistent with the actual drilling engineering events, which verifies the reliability of the three-pressure prediction results presented in this study. The results of the study can provide a basis for decision-making in drilling geological design, such as the determination of drilling fluid density, the evaluation of borehole stability and other engineering problems that require support from three-pressure data.
Evaluation of biocementation of slope soil for erosion control with low-cost materials
Authors: Moqsud M. Azizul , Gochi Takuya
Published: July 2024

In this study, biocementation of slope soil was performed using low-cost, commercially available materials to create a nutrient solution with native Cytobacillus hornekea. The high cost of laboratory-grade materials and microbes for biocementation is one of the main obstacles to its popularity. However, the cost of biocementation has been reduced significantly without reducing the strength when low-cost materials were used instead of laboratory-grade materials in this study. Direct shear test results and SEM also proved the suitability of the low-cost biocementation. Artificial rainfall with an intensity of 50–60 mm/h resulted in soil erosion of around 10% and 2% without and with biocementation, respectively. The amount of produced calcium carbonate was around 3.9% while using the low-cost materials with native microbes which is quite comparable with the laboratory-grade materials (3.4%).
New insights into the composition and catalytic performance of VOx-Ga/γ-Al2O3 for the oxidative dehydrogenation of propane to propene
Authors: Kandasamy Prabu , Gawali Sheetal , Venugopalan Aswathy Thareparambil , Manikandan Marimuthu , Mekala Siva Prasad , Shelke Ankita , Ajithkumar Thalasseril G. , Bhatte Kushal , Raja Thirumalaiswamy
Published: July 2024

This study demonstrates the influence of catalyst composition on catalytic insights towards enhanced catalytic activity of vanadium oxide and gallium oxide supported on γ-Al2O3 catalysts for the oxidative dehydrogenation of propane (ODHP).
Scalable synthesis of Bi2O2S nanoplates with large piezoelectric potential induced by a built-in electric field in a [Bi2O2]2+ layer for the degradation of organic contaminants
Authors: Wu Zhende , Xie Jing , Yin Suixin , Lu Zhenjiang , Hu Jindou , Cao Yali
Published: July 2024

2D piezoelectric catalysts with strong piezoresponse have valuable applications in catalytic degradation of pollutants and antibiotics, but the development of novel nanomaterials with powerful piezopotential still remains a serious challenge.
Improved separation of rare earth elements using hydrophobic deep eutectic solvents: liquid–liquid extraction to selective dissolution
Authors: Hanada Takafumi , Schaeffer Nicolas , Katoh Masahiro , Coutinho Joao A. P. , Goto Masahiro
Published: July 2024

Tuning steric environment of hydrophobic deep eutectic solvents improves dissolution selectivity of rare earth elements.
Synthesis of pyrrolo[2,3-d]pyridazines and pyrrolo[2,3-c]pyridines (6-azaindoles). Experimental and theoretical study
Authors: Efimov Ilya V. , Sultanova Yana V. , Cicolella Alessandra , Talarico Giovanni , Voskressensky Leonid G.
Published: July 2024

A new synthetic route towards 6-azaindoles (pyrrolo[2,3-c]pyridines) and pyrrolo[2,3-d]pyridazines starting from 4-aroyl pyrroles is described.
Unknown system dynamics estimator based control for sub‐synchronous oscillation of direct‐drive wind farms
Authors: Xi Xinze , Wang Min , Xing Chao , Tian Xincui , Wang Xian
Published: July 2024

Aiming at the problem of sub‐synchronous oscillations induced by direct‐drive wind farms with series‐compensated lines, this paper proposes an unknown system dynamics estimation‐based PI controller to achieve sub‐synchronous oscillation suppression. According to the mathematical model of the direct‐drive wind farm grid‐connected system, the relationship between the direct‐drive wind turbine grid‐side converter current inner‐loop PI controller and the sub‐synchronous components is first established. Secondly, the uncertain sub‐synchronous current components and voltage components in the series‐compensated lines of the direct‐drive wind farm are taken as the total disturbance, and an unknown system dynamic estimator‐based PI controller is designed by introducing the first‐order low‐pass filter operation. Then, the stability and convergence of the closed‐loop system are proved by Lyapunov theory. Finally, the Prony method is used to analyse the current signal output by the direct‐drive wind turbine, and the inherent characteristics of the negative damping of the SSO induced by the series‐compensated line of the direct‐driven wind farm are revealed. A comparative numerical simulation is carried out to demonstrate that the sub‐synchronous oscillations of the direct‐drive wind farm with series‐compensated lines can be suppressed under different operating conditions.
Receding horizon estimation for multi‐rate sampled data systems under component‐based event‐triggered mechanisms: Handling delayed and degraded measurements
Authors: Sun Zhenglu , Han Chunyan , Hu Xiaodong
Published: July 2024

The purpose of this article is to develop the receding horizon (RH) estimation for multi‐rate sampled systems with measurement delays and packet losses in the measurements. An event‐triggered transmission scheme is introduced to remove measurements that are unnecessary for the design of the estimator. The stochastic diagonal matrixes are introduced to represent the phenomenon of packet losses, where each component is subject to an individual Bernoulli process. The original system is firstly transformed into a delay‐free one by using the reorganized observation method. Further, a batch form and an iterative form of RH estimation are proposed by minimizing a given cost function that includes some terminal weighting terms based on the new system. The stability of the proposed RH estimation is guaranteed by the natural assumptions and a simulation instance is given to verify the effectiveness of the proposed method.
SmartCardio: Advancing cardiac risk prediction through Internet of Things and edge cloud intelligence
Authors: Durga S. , Daniel Esther , Andrew J. , Bhat Radhakrishna
Published: July 2024

Cardiovascular disease is a leading cause of illness and death globally. The integration of Internet of Things (IoT) and deep learning technologies, including transfer learning, has transformed healthcare by improving the prediction and monitoring of conditions such as arrhythmias, which can be fatal if not detected and treated promptly. Traditional methods often lack real‐time accuracy due to scattered data sources. A novel heart care approach utilising IoT technology and edge cloud computing is introduced to provide rapid, automated responses and support decision‐making. The system connects smart devices, sensors, and healthcare providers to predict patient conditions and deliver accessible healthcare services. It consists of two main phases: data acquisition, where sensors measure heart rate, temperature, and blood pressure, and data processing, where the edge cloud processes the data using Haar Wavelet transform, Convolutional Neural Network (CNN), and transfer learning. Experimental results demonstrate that this smart cardio system achieves 99.3% accuracy with reduced network delay and response time, outperforming traditional methods, such as k‐nearest neighbours, support vector machine, and discrete wavelet‐based convolutional neural network.
Optimal maintenance management for synchronous generators: A condition-based approach to predict and assess equipment wear
Authors: Vargas Geovanny Jimenez , Velez Ivan Endara
Published: July 2024

Currently, effective and early detection of potential failures is of paramount importance in power generation systems, posing a significant challenge for generating companies. This article proposes optimal maintenance policies using a condition-based maintenance (CBM) architecture for a case study based on a synchronous generator. These policies are defined based on the estimated degradation index of the different components of the synchronous generator. The results obtained demonstrate that the proposed model is capable of suggesting an accurate optimal maintenance policy by relating the severity of component damage to the average maintenance cost.
Optimization of indoor quality and thermal comfort for university classrooms using data-based machine learning
Authors: Jiang Qiwen , Liu Jialu , Yang Xian
Published: July 2024

Improving indoor environment quality on university classrooms is a hot research topic. The on-site experiment was conducted on indoor environmental quality regarding temperature, humidity, air pollutants, light and acoustics during different seasonal conditions. The result shows that nearly 25% of indoor particulate matters exceeded the GB18883 standard when the outdoor environmental pollution was severe under natural ventilation conditions in autumn. More than 20% of students experienced symptoms of drowsiness, dizziness, chest tightness, poor breathing, as well as depression and irritability. From the analysis of occupant demand, indoor air pollution and thermal comfort are the most anticipated areas for students to improve their learning environment. This paper proposes an optimal IEQ prediction model integrated with students’ satisfaction and indoor environmental features using machine-learning classification algorithms. The back-propagation neural network shows the high prediction accuracy among different algorithms. The traditional PMV-PPD model shows an accuracy rate of only 28% for thermal sensation prediction, while the highest prediction accuracy obtained through machine learning algorithms is about 75%. Moreover, the influence of individual’s thermal adaptation ability, including gender, long-term thermal experience, and psychological factors, and environmental factors was analyzed in this study.
Embodied carbon of structural earthen composites with natural materials and byproducts suitable for robotic 3d printing
Authors: Hanifa Mohamad Fouad , Daruari Harish , Figueiredo Bruno , Mendonça Paulo
Published: July 2024

The objective of this research is focused on 3D printing techniques using natural materials in the construction sector. Digital fabrication has captured widespread attention for its remarkable ability to craft parametric and complex geometry with relative ease. Beyond its technical prowess, this process holds great potential in addressing two pressing issues: waste management and carbon emissions, to reduce costs and environmental impacts. This study assesses the eco-efficiency of 3D printing with earthen composites compared to conventional construction materials in large-scale Robotic fabrication, employing the life cycle assessment (LCA) framework to quantify the environmental impacts of materials suitable for 3D printing. An eco-efficiency analysis was employed to aggregate the results of LCA into a single framework to assist in decision-making by selecting the most optimized and eco-efficient alternative. The findings indicate that shell structures built using additive manufacturing and 3D printed materials can be better optimized for efficiency. This paper comprehensively examines 3D printing with earth materials, focusing particularly on biocomposites, byproducts, and direct extrusion printing methods. Comparative analysis highlights the materials, processes, and industries driving these advancements. There has been a surge of interest in reinforcing 3D-printed structures with natural fibres and additives. A significant aspect of this study explores how 3D printing, especially when utilizing natural materials and byproduct-based composites, can contribute positively to the environment.
Optimized MPPT for Grid tied Transformer Less PV System: A Comparative Analysis
Authors: Gurram Janardhan , Surendra Babu N.N.V. , Srinivas G.N.
Published: July 2024

For grid-tied photovoltaic (PV) systems, Maximum Power Point Tracking (MPPT) algorithms based on artificial neural networks (ANNs) are prone to initialization issues, which could cause them to converge at local maxima rather than the global maximum power point (MPP). This means that, a regular retraining on big datasets is required. This paper presents a novel hybrid MPPT algorithm that combines Extreme Gradient Boosting (XGBoost) and Vascular Invasive Growth Optimization (VIGO) to address this challenge. The exploration-exploitation conundrum that traditional optimization algorithms have is addressed by VIGO, and the convergence speed and accuracy of MPPT are improved by XGBoost. To assess its performance, the suggested approach is compared with well-known methods such as Grasshopper Optimization Algorithm (GOA), Sparrow Search Algorithm (SSA), and Particle Swarm Optimization (PSO). This comparison study shows that the hybrid VIGO-XGBoost method produces improved maximum power.
Simulation of Hybrid Boost Converter with Reduced Switch Stress for PV Systems
Authors: Shanmugasundaram Ravivarman , Manojkumar P. , Sreedhar J. , Mallesh M. , Chanv Jayraj
Published: July 2024

Currently, there is a growing prominence on using switched capacitor and switched inductor techniques in high-power boost converters to achieve higher voltages. This is accomplished by employing reactive elements, where the inductor discharges while the capacitor charges. The switched capacitor and switched inductor can extremely attain dc voltage obtain with require few quantities like inductors, capacitors, diodes, and a switch. Modifications were made to the switched inductor converter, resulting in a reduction in the voltage stress on the active switch. The converter now operates based only on the duty ratio. This study suggests adjustments to the switched capacitor and switched inductor converter to decrease the stress on the switch by altering the duty ratio closer to unity. The paper covers the converter's operation, waveforms, design equations, and simulation results to illustrate this modified converter setup.
Revolutionizing Renewable Energy Integration: The Innovative Gravity Energy Storage Solution
Authors: Karuppiah Natarajan , Mounica Patil , Bhanutej J.N. , Saravanan S. , Reddy Rakshith , Israni Riaz
Published: July 2024

In recent times, energy storage has been a major concern in the renewable energy sector. Traditional batteries are becoming less effective and sustainable as the world is moving towards renewable energy. Gravity battery, also known as Gravitricity is a new energy storage technology that is gaining popularity in the renewable energy sector. Gravity battery uses excess energy to hoist heavy objects, and when needed, the objects are released, generating energy. This paper highlights the need for alternative energy storage systems and the potential of gravity batteries to address the limitations of traditional batteries. This paper provides an in-depth analysis of gravity battery technology including the need analysis, problem Statement, product producers, advantages, disadvantages, and how it can replace the present batteries in power systems. The paper concludes that gravity battery technology is a promising alternative to traditional batteries and requires further research and development to accelerate its adoption in the renewable energy sector.
Chronic Venous Disease: Pathophysiological Aspects, Risk Factors, and Diagnosis
Authors: Kienzl Philip , Deinsberger Julia , Weber Benedikt
Published: July 2024

Chronic venous disease (CVD) is highly prevalent in the general population and encompasses a range of pathological and hemodynamic changes in the veins of the lower extremities. These alterations give rise to a variety of symptoms, with more severe forms resulting in venous ulceration, which causes morbidity and high socioeconomic burden. The origins and underlying mechanisms of CVD are intricate and multifaceted, involving environmental factors, genetics, hormonal factors, and immunological factors that bring about structural and functional alterations in the venous system. This review offers the latest insights into the epidemiology, pathophysiology, and risk factors of CVD, aiming to provide a comprehensive overview of the current state of knowledge. Furthermore, the diagnostic approach for CVD is highlighted and current diagnostic tools are described.
Prospective feasibility study of a novel rigidizing stabilizing overtube in the resection of complex gastrointestinal polyps
Authors: Jawaid Salmaan , Aboelezz Ahmed F. , Daba Gehad , Khalaf Mai , Ayoub Fares , Zabad Noor , Mercado Michael , Keihanian Tara , Othman Mohamed
Published: July 2024

Background A novel rigidizing overtube (ROT) was developed to facilitate endoscopic removal of complex gastrointestinal polyps. We aimed to prospectively evaluate the efficacy and safety of the device in the management of large gastrointestinal polyps.

Methods A prospective, single-center study, conducted between May 2021 and April 2023, enrolled patients undergoing endoscopic resection of colon/duodenal polyps ≥25 mm. Primary outcomes were safety, technical success, and clinical success defined as the ability of ROT to facilitate endoscopic polyp removal without changing the initial resection method.

Results 97 patients (98 polyps), with a mean polyp size of 33.2 mm (median 31.1), were evaluated. Technical and clinical success rates were 100% and 84%, respectively. Ileocecal valve location was the only predictor of clinical failure (P = 0.02). The mean time to reach the lesion was 7.2 minutes (95%CI 5–8), with overall resection and procedure times of 53.6 minutes (95%CI 48–61) and 88.9 minutes (95%CI 79–95), respectively. No device-related adverse events occurred. Lower technical (67%) and clinical (67%) success rates were seen for duodenal polyps (n = 6).

Conclusion The novel ROT was safe, with high technical and clinical success during resection of complex colon polyps. Future studies will determine timing of implementation during routine endoscopic resection.
Role of Medical and Surgical Treatment in Management of the Patients
With Prolactinoma: A Single-Center Experience
Authors: Zulfaliyeva Guldana , Demir Ahmet Numan , Cetintas Semih Can , Ozaydin Dilan , Tanriover Necmettin , Kadioglu Pinar
Published: July 2024

Abstract

Background Current guidelines recommend dopamine agonists (DA) as the
primary therapeutic approach for prolactinomas; however, emerging evidence
suggests that surgical intervention can also yield favorable outcomes.

Objective To comprehensively evaluate prolactinoma patients undergoing
surgical and medical treatments at our pituitary center.

Methods Retrospective review of mMedical records from prolactinoma
patients treated between 2015 and 2022 was performedwere retrospectively
reviewed. The study focused on treatment outcomes and remission rates while
investigating factors influencing the success of both treatment modalities in
achieving remission.

Results A total of 301 prolactinoma patients were included, of whom 199
were women. Among them, 235 were managed medically, while 66 underwent surgical
intervention. The overall remission rates of patients treated with medical and
surgery were similar at the final examination (Respectively respectively 82.9%
and 81.8%, p=0.114). Factors associated with remission in both treatment
modalities included female sex, low initial prolactin levels, small adenoma
size, and absence of cavernous invasion. Compared to DA treatment, Ssurgical
treatment demonstrated a higher rate of drug-free remission compared to DA
treatment for microadenomas, and macroadenomas without cavernous invasion. In
cases with cavernous invasion, standalone surgical treatment yielded a low rate
of drug-free remission (7.7%); however, when combined with DA therapy
post-surgery, remission rates increased to 66.7%.

Conclusion Medical treatment with DAs remains the preferred option for
macroadenomas with cavernous sinus invasion, and giant adenomas, with surgery
reserved for selected cases to address complications. Conversely, surgery
emerges as the most effective modality for achieving remission in patients with
microadenomas, and macroadenomas confined to the sella. The recommendation of
DAs as first-line therapy for all patients has been withdrawn in the current
guidelines, and individual treatment approaches based on tumor characteristics
are emphasized. Our results support this approach.
Scalable capillary-pin-fin structure enabled efficient flow boiling
Authors: Luo Kai , Foysal Fahim , Chang Wei , Santi Enrico , Li Chen
Published: July 2024

Flow boiling with dielectric coolant is not only a highly desirable approach for effective electronic cooling but is also notorious for its poor scalability. Most current flow boiling enhancement strategies are based on silicon substrates with footprint areas less than 1 cm2, which greatly limits their applications to large-size electronics. This study developed a scalable channel configuration to facilitate efficient flow boiling on large copper substrates (∼10 cm2), in which the channel walls are formed by porous pin-fin arrays. This type of hybrid capillary wall makes up for the limitation of conventional machining in creating intricate features, making it scalable and feasible for developing large-size, two-phase cold plates. Moreover, effective two-phase separation and sustainable film evaporation have been realized in the current work. As a result, the proposed structure achieved a 512% increase in heat dissipation when the heating area scales up 480% from the silicon microchannels with micro-pin-fin arrays. Experiments showed a base heat flux of 106.1 W/cm2 was dissipated over a heating area of 9.6 cm2 using the dielectric fluid HFE-7100 at a mass flux of 247 kg/m2 s. It outperformed most existing metallic flow boiling heat sinks using the same coolant at a similarly high coefficient of performance as small-size enhanced silicon microchannels.
Computational demonstrations of density wave of Cooper pairs and paired-electron liquid in the quarter-filled band—A brief review
Authors: Mazumdar Sumit , Torsten Clay R.
Published: July 2024

There has been strong interest recently in the so-called Cooper pair density wave, subsequent to the proposition that such a state occurs in the hole-doped cuprate superconductors. As of now, there is no convincing demonstration of such a state in the cuprate theoretical literature. We present here a brief but complete review of our theoretical and computational work on the paired-electron crystal (PEC), which has also been experimentally seen in the insulating phase proximate to superconductivity (SC) in organic charge-transfer solid (CTS) superconductors. Within our theory, SC in the CTS does indeed evolve from the PEC. A crucial requirement for the finding of the PEC is that the proper carrier density of one charge carrier per two sites is taken into consideration at the outset. Following the discussion of CTS superconductors, we briefly discuss how the theory can be extended to understand the phase diagram of the cuprate superconductors that has remained mysterious after nearly four decades of the discovery of SC in this family.
Near-infrared focused heating method for the rotational diamond anvil cell
Authors: Azuma Shintaro , Okazaki Keishi , Uesugi Kentaro , Yasutake Masahiro , Natsui Bunrin , Jayawickrama Eranga , Ishimori Keiya , Okuda Yoshiyuki , Park Yohan , Nomura Ryuichi
Published: July 2024

We developed a near-infrared focused heating system (IRrDAC) for deformation experiments using a rotational diamond anvil cell. This study reports the results of annealing tests on silver and antigorite conducted at SPring-8 (BL47XU) using the IRrDAC system. The experimental results demonstrated the melting of silver and the dehydration of antigorite, confirming the capability of this system. The reproducible relationships between temperature and input power were also confirmed. The IRrDAC system enables deformation experiments at pressures equivalent to those of the lower mantle under homogeneous and stable temperatures and is expected to contribute to the understanding of deep Earth rheology.