bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognostic Impact of Surgical Margin Status on Overall Survival of Patients with Early Breast Cancer: A Retrospective Analysis from the Department for Women’s Medicine at Charité – University Hospital Berlin
Authors: Beck Maximilian Heinz , Weiler Karoline Barbara Stephanie , Trelinska-Finger Anna , Blohmer Jens-Uwe
Published: September 2024

The impact of surgical margins on the prognosis of early breast cancer remains uncertain, particularly in the context of modern treatment approaches. This study aimed to investigate whether involved margins after surgery for early breast cancer affect overall survival.

We conducted a retrospective analysis of 3767 patients who underwent surgery for primary breast cancer or carcinoma in situ between 2006 and 2022 at Charité – University Hospital Berlin. Survival analysis based on margin status and a subsequent multivariate Cox regression analysis were conducted.

With a median follow-up of 72.2 months, clear margins were achieved in 81.4% of patients (n = 3068) after primary surgery, while 16.2% (n = 610) required re-excision. Only 2.4% of patients (n = 89) had definitively involved margins. Margin involvement was more common in hormone receptor-positive disease, lobular subtype, carcinoma in situ, or locally advanced tumors, but less frequent in patients with previous neoadjuvant chemotherapy or triple-negative breast cancer. The Kaplan–Meier survival curves showed a significant separation with worse outcomes for patients with definitive R1 resections. However, the multivariate Cox regression analysis detected no statistically significant difference in overall survival based on margin status. Breast conserving surgery (HR 0.66; 95% CI 0.54–0.81) and HER2 overexpression (HR 0.65; 95% CI 0.48–0.89) were associated with improved survival.

Patients who underwent breast-conserving surgery in our study demonstrated favorable outcomes compared to patients after mastectomy. Although margin status did not significantly affect overall survival, larger multicenter studies are needed to evaluate the prognostic implications of margin involvement in breast cancer treatment in different tumor stages, tumor subtypes and local and systemic treatments.
Novel Antibody-Drug-Conjugates in Routine Clinical Practice for the Treatment of Metastatic Breast Cancer: Adherence, Efficacy and Tolerability – Real-World Data from German Breast Centers
Authors: Schäffler Henning , Jakob Dorothee , Huesmann Sophia , Pfister Kerstin , Veselinovic Kristina , Schochter Fabienne , Leinert Elena , Fink Visnja , Rack Brigitte , Englisch Alexander , Volmer Lea-Louise , Engler Tobias , Frevert Marie Louise , Juhasz-Böss Ingolf , Brucker Sara , Heublein Sabine , Janni Wolfgang , Taran Florin-Andrei , Hartkopf Andreas , Dannehl Dominik
Published: September 2024

The third-generation antibody-drug conjugates (ADC), trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG), recently obtained approval for metastatic breast cancer treatment across various subtypes and therapeutic contexts.

This retrospective, multicentric study evaluated real-world tolerability, feasibility and efficacy in a pre-treated, real-world cohort at three major German breast cancer centers.

125 patients treated with T-DXd or SG from November 2020 to June 2023 were included (T-DXd: 77 patients; SG: 48 patients). The median treatment duration was 6.0 months for T-DXd and 3.5 months for SG therapy, with a median follow-up duration of 10.4 months for T-DXd (95% CI: 8.4–11.6) and 11.8 months for SG (95% CI: 8.0–14.4). Severe neutropenia (CTC ≥ III°) occurred in 33.3% during SG therapy, with a numerical reduction observed following primary, prophylactic use of G-CSF. T-DXd-associated pneumonitis occurred in 8 out of 77 patients (10.4 %). Median progression-free survival (mPFS) was 8.6 months (95% CI: 5.8–12.4) with T-DXd (HER2+: 10.8; HER2-low: 4.7) and 4.9 months (95% CI: 2.8–6.3) with SG (TNBC 4.9; HR+/HER2−: not reached). Median overall survival (OS) was 23.8 months (95% CI: 16.1–not estimable) with T-DXd (HER2+: 27.1; HER2-low: not reached), and 12.4 months (95% CI: 8.7–not estimable) with SG therapy (TNBC: 12.4, HR+/HER2−: not reached). 95.7% of the
protocol-specified, therapeutic dose was administered for T-DXd and 89.6% for SG.

Overall, this indicates good feasibility, tolerability, and effectiveness of ADC therapies in the real-world setting.
Delivery Hospitalization Cardiac and Respiratory Complications during SARS-CoV-2 Delta Variant Dominance
Authors: Wang Ruiyan M. , Friedman Alexander , Booker Whitney A. , Liu Lilly Y. , Wen Timothy
Published: September 2024

In 2021, the severe acute respiratory syndrome coronavirus 2 Delta variant rapidly proliferated and became dominant. Some but not all research evidence supports that Delta was associated with increased maternal risk. The purpose of this study was to determine whether Delta was associated with risk for cardiac and respiratory complications in a national sample. Of an estimated 3,495,188 delivery hospitalizations in 2021, 1.8% of pre-Delta deliveries (n = 29,580; January–June) and 2.1% of Delta-period deliveries (n = 37,545; July–December) had a coronavirus disease 2019 (COVID-19) diagnosis. The Delta period was associated with increased adjusted odds of respiratory complications (adjusted odds ratio [aOR] = 1.54, 95% CI: 1.41, 1.69) and cardiac severe maternal morbidity (SMM; aOR = 1.54, 95% CI: 1.40, 1.69). Among deliveries with a COVID-19 diagnosis, the Delta period was associated with a higher incidence of respiratory complications (8.4 vs. 3.7%) and cardiac SMM (8.4 vs. 3.5%; p < 0.01 for both). These findings corroborate prior clinical studies suggesting that the Delta strain was associated with an increased maternal population-level clinical burden.

Key Points
Cobalt-Catalyzed Regio- and Enantioselective Hydroalkylation of 1,1-Disubstituted Styrenes
Authors: Lu Xi , Li Yan
Published: September 2024

The metal hydride catalyzed alkene hydroalkylation enables efficient alkyl–alkyl coupling, yielding structurally diverse chiral organic compounds. However, the control of stereochemical selectivity in alkene hydroalkylation still heavily relies on the assistance of substrate Lewis basic functional groups or polar heteroatom functional groups. We have recently developed a cobalt hydride catalytic system and established a paradigm of enantioselective control assisted by C–H···π noncovalent interactions. This approach enables the asymmetric hydroalkylation of 1,1-disubstituted styrenes, thereby circumventing the limitations imposed by substrate heteroatom functional groups.

1 Introduction

2 Reaction Development

3 Synthetic Applications

4 Mechanistic Investigation

5 Conclusion and Future Outlook
Methoxydioxasilepane: A Versatile and Stable Synthetic Precursor of Trimethoxysilane
Authors: Shimokawa Jun , Yorimitsu Hideki , Hitoshio Kenshiro , Morinaga Takuto , Sahashi Ryohei , Goshona Shinya , Yamagishi Hiroki , Saito Hayate
Published: September 2024

This study introduces aryl(methoxy)dioxasilepane as a versatile and stable precursor for aryl(trimethoxy)silanes. We conducted a quantitative assessment of the stability of this silicon moiety under acidic and basic conditions, demonstrating its superior stability compared to triethoxysilane, and methyl- or (trifluoroethoxy)dioxasilepanes. The synthetic utility of the methoxydioxasilepane unit was further elucidated through an examination of its orthogonality and selective functionalization capabilities. Notably, we developed an efficient method for the conversion of methoxydioxasilepane into trimethoxysilane. This method underscores the potential of a methoxydioxasilepane as a surrogate in multistep syntheses of silanetriols, which offer advantages in the development of silicon-based bioisosteres for medicinal chemistry applications.
Improving Diagnostic Yield and Accuracy of Stereotactic Biopsies through Changes in Practice and Techniques: An 8-Year Single-Center Comparative Study
Authors: Vijian Kugan , Lau Bik Liang , Kanesen Davendran , Lim Swee San , Ngian Donald L. , Wong Albert S. Hieng
Published: September 2024

Background Stereotactic biopsies are used to aid neurosurgeons in clinching the diagnosis of intracranial lesions that are difficult to access surgically. A published study of stereotactic biopsies in our center demonstrated a diagnostic yield of only 76% for biopsies from the year 2014 to 2019. A set of criteria/prerequisites was applied to increase yield.

Objective The aim of the study was to identify the improvement in accuracy and yield after implementation of a set of criteria/prerequisites.

Materials and Methods This was a retrospective and prospective analysis of all patients who underwent stereotactic biopsies from the year 2014 to 2022. This study was conducted at Sarawak General Hospital, Malaysia. A set of stereotactic criteria/prerequisites was introduced since 2020, which include preoperative careful, meticulous trajectory planning and target selection, regular checking and maintenance of equipment, larger burr holes, and good sampling techniques.

Results A total of 83 patients underwent stereotactic biopsies from the year 2014 to 2022. Frameless and frame-based methods were used for 45 (54%) and 38 (46%) patients, respectively. The overall diagnostic yield of all biopsies was 84%. Fifty patients underwent stereotactic biopsies prior to implementation of good practice guidelines in 2020 with a positive histopathological yield and accuracy of 76 and 88%, respectively. Thirty-three biopsies done postimplementation demonstrated a yield and accuracy of 97% (p < 0.05). There was also a shift of preference toward frame-based methods after 2019, with 85% of these biopsies being frame based.

Conclusion This comparative study shows that adherence to specific stereotactic biopsy guidelines and techniques introduced in our center has successfully improved our biopsy yield and accuracy.
Arthroscopic Dorsal Round-Block Capsulo-Ligamentoplasty for Dynamic Scapholunate Instability: An Anatomical Study and Case Series
Authors: Goorens Chul Ki , Van Royen Kjell , Atzei Andrea
Published: September 2024

Background Chronic dynamic scapholunate (SL) instability remains difficult to treat. Several treatment options exist.

Purpose We propose an arthroscopic dorsal round-block capsulo-ligamentoplasty technique to treat dynamic scapholunate instability: a dorsal purse-string-like suture around the dorsal aspect of the proximal row, following the course of the dorsal intercarpal ligament (DICL). A Fiberwire suture travels between the radiocarpal and midcarpal space, piercing the attachments of the DICL on the triquetrum and of the scaphotrapezial ligament on the distal scaphoid. It reinforces the DICL and the dorso-capsuloscapholunate septum, also inducing a fibrotic healing. Moreover, it produces an extension lever correcting the scaphoid flexion/pronation. Compared with other capsulodesis techniques, the all-inside dorsal round-block capsulo-ligamentoplasty is theoretically likely to produce less stiffness, without additional damage to the SL complex. The wrist remains practically undamaged after surgery: no bone tunnels, bone anchors, or tendon grafts are required, thus enabling all possible secondary procedures. Data of a cadaveric study and case series illustrate the technique.

Conclusion The arthroscopic dorsal round-block capsulo-ligamentoplasty can be considered to treat chronic dynamic scapholunate instability.
Chronic diseases and their behavioural risk factors among South Asian immigrants in Australia
Authors: Nisar Mehwish , Kolbe-Alexander Tracy , Khan Asaduzzaman
Published: September 2024

Objectives The prevalence of chronic diseases among immigrants varies across different ethnic groups attributed to the disparities in their risk factors. This study aimed to explore the prevalence and correlates of chronic diseases among the rapidly growing South Asian population in Australia. Methods An online survey was administered (2020–2021) among South Asian immigrants in Australia. Diagnosed chronic diseases, smoking habits, physical activity, alcohol consumption, body mass index, and fruit and vegetable intake were assessed. A multivariable logistic regression model was used to examine factors associated with chronic disease. Results Overall, 50% of the study participants had one chronic disease and 39% had more than one chronic disease (n = 282). Back pain (30%), depression (22%), diabetes (21%), hypertension (19%), and heart disease (12%) were the most reported diseases. Approximately 78% of participants were insufficiently active and 38% regularly consumed alcohol. Approximately three-quarters consumed fruits and vegetables less than once per day. Multivariable analyses showed that those who were aged more than 50 years (OR = 4.38, 95% CI 1.66–11.56), consumed alcohol more than once/month (OR = 3.25, 95% CI 1.17–8.96), and ate less than one serving of vegetables/day (OR = 2.94, 95% CI 1.19–7.26) had higher odds of having two or more chronic diseases. Conclusions Fifty percent of study participants presented with preventable diseases, signifying a substantial health burden. Public health interventions should primarily focus on reducing alcohol intake and increasing fruit and vegetable consumption, particularly among individuals of advanced age, to reduce the overall burden on the healthcare system.
Methods and current developments of the Solvay process for brine management and CO2 capture: a critical review
Authors: Rahimi-Ahar Zohreh , Ghareghashi Abbas
Published: September 2024

Environmental context This manuscript focuses on the introduction of the conventional and modified Solvay processes. The Solvay process is used to produce sodium carbonate and sodium bicarbonate, while also providing brine management and CO2 capture. Optimal values must be used for reactant contents, temperature, salinity of the brine and stirring rate to enhance efficiency. Abstract The Solvay process is used to produce sodium carbonate and sodium bicarbonate. Simultaneous brine management and CO2 capture occur by the Solvay process. In this review, the Solvay process based on different solutions (i.e. NH3, KOH, CaO, Ca(OH)2 and alcohol amines) is reviewed. The most efficient processes considering CO2 uptake and Na+/Cl− removal are introduced. The Solvay process benefits from increasing NH3 content, salinity, stirring rate, decreasing temperature and using inert mixing particles in the reactor. Adding NH4HCO3, extra KOH in subsequent stages and brine pretreatment are recommended. The results show that a Ca(OH)2-based Solvay process, an NH3-based process running in contactor and reactor, and a 2-amino-2-methylpropanol-based Solvay process obtain the highest CO2 capture efficiencies of 99, 98 and 80% respectively.
Impacts of the new UM convection scheme, CoMorph-A, over the Indo-Pacific and Australian regions
Authors: Zhu Hongyan , Hudson Debra , Li Chen , Shi Li , White Bethan , Young Griffith , Stirling Alison , Whitall Michael , Lock Adrian , Lavender Sally , Stratton Rachel
Published: September 2024

A new convection scheme, ‘CoMorph-A’, has been introduced into the latest UK Met Office coupled (GC4) and atmosphere-only (GA8) models. In this study, the impact of CoMorph-A is assessed in atmosphere-only Atmospheric Model Intercomparison Project simulations, as well as in sets of initialised 28-day forecasts with both the coupled and uncoupled models. Initial results show improvements over the Indo-Pacific and northern Australian regions, as well as improvements in the rainfall bias, Madden–Julian Oscillation simulation and prediction, tropical cyclone forecasts and the diurnal cycle of rainfall over the Maritime Continent. The improvements are mostly consistent across the initialised forecasts and the climate simulations, indicating the effectiveness of the new scheme across applications. The use of this new convection scheme is promising for future model configurations, and for improving the simulation and prediction of Australian weather and climate. The UK Met Office is continuing to develop CoMorph and will soon release version B.
Protracted bar closure temporarily transforms an estuary into a salt lake
Authors: Tweedley James R. , Krispyn Kurt N.
Published: September 2024

Protracted disconnection from the ocean, low rainfall and high evaporation led to salinities in Hamersley Inlet, south-western Australia, reaching 345 ppt, the highest recorded for an estuary. These conditions resulted in the loss of the fish fauna and associated ecosystem services. Climate change may increase the frequency of such events.
COOMET key comparison COOMET.PR-K1.a.2018 for spectral irradiance 250 nm to 2500 nmm, final report
Authors: Khlevnoy B B , Solodilov M V , Kolesnikova S S , Otryaskin D A , Korseko I V , Nikanenka S V , Huriev M V , Sametoğlu F
Published: September 2024

Main text

This report describes the Key Comparison COOMET.R-K1.a.2018 for spectral irradiance in the wavelength range of 250 nm to 2500 nm, conducted by the Regional Metrology Organization "Euro-Asian Cooperation of National Metrological Institutions" (COOMET). The comparison was, in fact, a combination of three bilateral comparisons with the same link/pilot laboratory - the All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), the Russian Federation. The non-link laboratories were the Belarusian State Institute of Metrology (BelGIM), Belarus, the National Scientific Centre "Institute of Metrology" (NSC IM), Ukraine, and the National Metrology Institute of Türkiye (TÜBİTAK UME), Türkiye.

The aim of the comparison was to link the BelGIM, NSC IM and TÜBİTAK UME measurement results to the CIPM key comparison CCPR-K1.a.2017, conducted by the Consultative Committee for Photometry and Radiometry (CCPR).

Tungsten quartz halogen lamps of the FEL type (1000 W) were used as artefacts. Each participant used its own set of lamps. The sequence of measurements was participant - pilot - participant. The pilot measurements of the described here COOMET comparison were performed in a short time (within three months) after completing the measurements of CCPR-K1.a.2017, where VNIIOFI also was a pilot, which provided a high quality link.

NSC IM performed measurements in the full spectral range, from 250 nm to 2500 nm, while BelGIM and TÜBİTAK UME managed to cover the range from 250 nm to 1100 nm only.

The analysis of the comparison was performed following the approach described in the Appendix A of the Guidelines for CCPR and RMO Bilateral Key Comparisons (CCPR-G5). Differences from KCRV of BelGIM and TÜBİTAK UME, for the most of the measured wavelengths, do not exceed 2% and are within the expanded uncertainties. For NSC IM the differences from KCRV are within or comparable with the uncertainties in the IR range, from 900 nm to 2500 nm, but become larger with decreasing wavelength in the visible and UV reaching 9% at 250 nm.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Final report, ongoing key comparison BIPM.QM-K1, ozone at ambient level, comparison with VSL, April 2024
Authors: Viallon Joële , Idrees Faraz , Moussay Philippe , Wielgosz Robert , Meijer Luuk , Veen Adriaan van der
Published: September 2024

Main text

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone standard of the Netherlands maintained by the Van Swinden Laboratorium (VSL) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount fraction range of 0 nmol mol−1 to 500 nmol mol−1.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Spatially-homogeneous cosmologies
Authors: Antonio Sáez Juan , Mengual Salvador , Josep Ferrando Joan
Published: September 2024

The necessary and sufficient conditions for a perfect fluid solution to define a spatially-homogeneous cosmology are achieved. These conditions are Intrinsic, Deductive, Explicit and ALgorithmic, and they offer an IDEAL labeling of these geometries. When a three-dimensional group acts on the three-dimensional space-like orbits, the Bianchi type of the model is also obtained.
Extension of the characterization of non-Gaussianity in gravitational wave detectors with a statistical hypothesis test
Authors: Yamamura Shunsei , Yuzurihara Hirotaka , Yamamoto Takahiro , Uchiyama Takashi
Published: September 2024

In gravitational wave (GW) astronomy, non-Gaussian noise, such as scattered light noise disturbs stable interferometer operation, limiting the interferometer’s sensitivity, and reducing the reliability of the analyses. In scattered light noise, the non-Gaussian noise dominates the sensitivity in a low frequency range of less than a few hundred Hz, which is sensitive to GWs from compact binary coalescence. This non-Gaussian noise prevents reliable parameter estimation, since several analysis methods are optimized only for Gaussian noise. Therefore, identifying data contaminated by non-Gaussian noise is important. In this work, we extended the conventional method to evaluate non-Gaussian noise, the Rayleigh statistic, by using a statistical hypothesis test to determine a threshold for non-Gaussian noise. First, we estimated the distribution of the Rayleigh statistic against Gaussian noise, called the background distribution, and validated that our extension serves as the hypothetical test. The threshold on the Rayleigh statistic is estimated at 0.73 and 1.28 when the significance level is 0.05, and the sample size is 39. Moreover, we investigated the detection efficiency by assuming two non-Gaussian noise models. For example, for the model with strong scattered light noise, the true positive rate (TPR) was always above 0.7 when the significance level was 0.05. For the demonstration, we applied our extension with the estimated thresholds to the real data. We confirmed our extension provides the binarized outputs of the statistical tests and contributes to finding the non-Gaussian noise in the real data. The results showed that our extension can contribute to an initial detection of non-Gaussian noise and lead to further investigation of the origin of the non-Gaussian noise.
Chemo-elasto-electro free energy of non-uniform system in the diffuse interface context
Authors: Cai Yuhan , Wang Fei , Zhang Haodong , Nestler Britta
Published: September 2024

In the present work, we propose an alternative approach for deriving the free energy formulation of a non-uniform system. Compared with the work of Cahn and Hilliard (1958 J. Chem. Phys.
28 258–67), our approach provides a more comprehensive explanation for the individual energy contribution in a non-uniform system, including entropy, interaction energy, and internal energy. By employing a fundamental mathematical calculus, we reformulate the local composition within the interface region. Utilizing the reformulated local composition as well as classic thermodynamic principles, we establish formal expressions for entropy, interaction energy, and the internal energy, which are functions of both composition and composition gradients. We obtain a comprehensive free energy expression for a non-uniform system by integrating these energy density formulations. The obtained free energy expression is consistent with the formula type of Cahn and Hilliard and prodives more deeper physical interpretation. Moreover, using the same approach, we derive formulations for elastic energy and electric potential energy in a non-uniform system. However, the proposed approach encounters a limitation in the special case of a non-uniform fluid contacting a solid substrate. Due to the significant difference in the length scales between the solid–fluid and fluid–fluid interfaces, the wall free energy formulation based on the aforementioned concept is unsuitable for this multi-scale system. To address this limitation, we reformulate the wall free energy as a function of the average composition over the solid–fluid interface. Additionally, the previous derivation relies on an artificial treatment of describing the composition variation across the interface by a smooth monotone function, while the true nature of this variation remains unclear. By utilizing the concept of average composition, we circumvent the open question of how the composition varies across the interface region. Our work provides a thorough understanding for the construction of free energy formulations for a non-uniform system in condensed matter physics.
Super-resolved fluorescence imaging utilising accessible stochastic optical reconstruction microscopy (easySTORM) implemented on a low-cost, modular open-source (openFrame) microscope
Authors: Bharadwaj Anupam , Kumar Amalesh , Kalita Ranjan , MITRA RUMELA , Sharma Amit , Jaganathan Bithiah Grace , Bhattacharyya Jina , Sarma Anupam , Garcia Edwin , Boruah Bosanta Ranjan , Kumar Sunil , Lightley Jonathon , Alexandrov Yuriy , Dunsby Christopher , Neil Mark , French Paul M W
Published: September 2024

Optical super-resolution microscope is a powerful tool for the life sciences, including cell biology and pathology yielding information on, e.g., biological structure and protein distribution in the nano-scale range. In recent years, there has been an exponential rise in the interest to apply super-resolution microscopes in diverse areas, but its wider utility is hindered by the cost of purchasing and maintaining super-resolved microscopes. In this paper we present the implementation of easySTORM, an accessible implementation of stochastic optical reconstruction microscopy (STORM) at Indian Institute of Technology Guwahati (IITG), India, in a flexible, user friendly and cost-effective manner using a state-of-the-art, modular, open-source, optical microscope platform called: "openFrame". Providing comparable imaging performance to commercial optical super-resolution microscopes, the openFrame-based implementation of easySTORM uses in-expensive multimode diode lasers and industry grade CMOS cameras, and the open-source and modular nature of the instrument makes it easy to maintain and to upgrade. To demonstrate its successful implementation at IITG, we image quantum dots and actin-tubulin structure in both normal and cancer cells, resolved features separated by a few tens of nanometers. This work demonstrates that openFrame-enabled easySTORM instrumentation can be widely accessible to provide affordable, research grade super-resolution microscopy capability for academic and medical research.
Efficient and low-drift point-cloud mapping method for GNSS weak and obstructed areas
Authors: Tu Zhiyong , Song Weiwei , Lou Yidong , Wen Jingren
Published: September 2024

Road modelling based on point-cloud data often encounters signal-rejection areas, where the absence of absolute position constraints leads to rapid error accumulation in the constructed map. Mitigating error growth requires manual setting of control points, which compromises automation in the mapping process and causes a challenging trade-off between efficiency and accuracy. To address these issues, in the present study, we designed a fast and efficient map-construction method that provides absolute pose constraints for simultaneous localisation and mapping based on the bidirectional filter position of the global navigation satellite system (GNSS)/inertial measurement unit integrated navigation. First, we designed an absolute position constraint factor (BF_Factor) updated at each epoch according to the reference-position difference and time-delay error, which can significantly mitigate error divergence during mobile mapping in a GNSS-rejected region. An adaptive noise model was then constructed for the above factors so that the weights of different factors could be adjusted automatically to achieve a more accurate mapping result. Finally, we conducted experimental tests on the proposed mapping approach in two scenarios that included multiple GNSS-rejected areas. Even when several hundred metres of GNSS signal-obstructed areas were present in the scene, the relocation results indicated that the three-dimensional position error obtained using point-cloud maps was <0.15 m and the pitch/roll error was better than 2°. Compared with Fastlio2 and Fastlio2 with Scan Context, the proposed method had a better mapping effect and higher mapping accuracy in the aforementioned scenarios. The method proposed in this paper can reduce the human labour cost in traditional modelling and can provide more rapid and accurate map for related industry applications.
UAV swarm path planning approach based on integration of multi-population strategy and adaptive evolutionary optimizer
Authors: Wang Chuanyun , Hu Anqi , Gao Qian , Liu Qiong , Wang Tian
Published: September 2024

Addressing the optimal path planning problem encountered by swarm of unmanned aerial vehicle (UAV) in three-dimensional space under multiple constraints, the Multi-population Adaptive Cuckoo Search and Grey Wolf Optimizer (MACSGWO) integrates Multi-Population (MP) strategies and adaptive evolutionary optimizer including the enhanced Adaptive Grey Wolf Optimizer (AGWO) and adaptive Cuckoo search (ACS). The optimizer strategically divides the initial population into multiple sub-groups, enabling each sub-group to independently iterate. During the iteration process, the algorithm adaptively adjusts parameters based on the optimal fitness values obtained by each sub-group after each iteration. The iteration cycle is divided into two stages: during the global exploration phase, each sub-group autonomously executes AGWO and periodically shares the fitness information of the Alpha wolf with other sub-groups, accelerating convergence. In the subsequent local optimization phase, MACSGWO dynamically decides whether to initiate ACS based on the disparity in the best fitness of each sub-group after each iteration, assisting the algorithm in escaping local optima. In experiments involving various complex benchmark functions and swarm path planning scenarios, MACSGWO demonstrated significant superiority in solution stability, convergence speed, and optimal convergence value compared to multiple existing variant algorithms. The integration of MACSGWO with the best relay UAV selection strategy further optimized the communication efficiency within the swarm. MACSGWO ensures the efficient resolution of UAV swarm path planning problems, providing robust support for optimization challenges in complex, multi-constraint scenarios.
Modified central frequency mode decomposition for the fault diagnosis of rotating machinery
Authors: Zhang Wanliang , Jiang Xingxing , Sima Can , Song Qiuyu , Meng Tao , Zhu Zhongkui
Published: September 2024

Central frequency mode decomposition (CFMD) is a promising tool for complex mechanical signal processing. Some characteristics of CFMD are disclosed by performing a detailed discussion on its decomposing theory in this study. As a result, three deficiencies of CFMD are found through the characteristic analysis, including the low accuracies of detected central frequencies (CFs), the filters with too wide bandwidth, and the excessive number of the decomposed modes. To address these issues, a modified CFMD (MCFMD) method is proposed for enhancing its performance of fault diagnosis. First, an exchange weighting function is defined to improve the accuracies of detected CFs. Then, the combination of the detected CFs and the separating information of modes is used to optimize the structures of filters for excluding the interferential information as much as possible. Furthermore, the number of the decomposed modes are compressed based the properties of the fault-related modes to facilitate the implementation of the diagnosis tasks. Lastly, a product envelope spectrum is introduced for further enabling the fault characteristic frequency in the fault-related modes to be more prominent while suppressing other noises. Analysis results verified the effectiveness of the MCFMD and its superiority over some existing advanced methods in the fault diagnosis of rotating machinery.
A fault detection of aero-engine rolling bearings based on CNN-BiLSTM network integrated cross-attention
Authors: Jiang Zhilei , Li Yang , Gao Jinke , Wu Chengpu
Published: September 2024

Aero-engine rolling bearings are essential for engine health, in which disruptive failures can be prevented and reduce great losses in air flight. To improve the efficiency of fault detection, an improved network, named CNN- BiLSTM -Cross-Attention (CBLCA) was proposed. The Bidirectional Long Short-Term Memory (BiLSTM) layer captures the temporal features as the input data. The cross-attention mechanism is integrated with the Convolutional neural networks (CNN) layer and the BiLSTM layer respectively. More important feature information can be identified with the CBLCA model. The proposed model was also validated with the open-sourced aero-engine rolling bearings data set. To improve the identification accuracy, a novel method that combines fast Fourier transform and Variational mode decomposition is used for the data preprocessing. Each original signal sample is transformed into a feature set containing richer information, and the number of features significantly increased in the entire dataset. Compared with some existing LSTM models, such as LSTM, BiLSTM, CNN-BiLSTM, and CNN-LSTM, the classification accuracy was increased by 55%, 54%, 5%, and 7%, respectively. The processing method for vibration signals and the CBLCA model can improve the accuracy and reliability of fault diagnosis for aero-engine rolling bearings.
A novel weighted-guided tensor completion missing data imputation method for health monitoring data of planar parallel mechanism
Authors: Wu Qiqiang , Zhang Xianmin , Zhao Bo
Published: September 2024

High-end mechanical equipment plays a crucial role in the manufacturing industry, making the monitoring of its operational status highly significant. Due to various factors such as environmental influences, the absence of monitoring signals in mechanical equipment status is a common issue, leading to a decline in data quality. To ensure data quality, this paper proposes an adaptive weighted low-rank tensor missing data imputation method. Firstly, based on the motion characteristics of a planar parallel mechanism (PPM), a new low-rank tensor model is established using periodicity, sliding windows, and time series. Secondly, the tensor truncation nuclear norm is defined, and a novel rate parameter is introduced to control the truncation degree of all tensor modes, thereby obtaining weights for each dimension. Finally, within the framework of the alternating direction method of multipliers, adaptive weights for each dimension are obtained during each iteration, completing the filling of missing data. Two types of missing patterns are studied on a PPM experimental platform, and the results showed that as the missing rate increased, the mean absolute percentage error is less than 0.018, and root mean square error is less than 0.001, and the rate of change is less than 0.08, which was significantly better than other compared algorithms.
Remaining useful life prediction based on time-series features and conformalized quantile regression
Authors: Mao Song , Li Xiaofeng , Zhao Boyang
Published: September 2024

The remaining useful life (RUL) prediction is a key task in the field of prognostics and health management (PHM) and plays a crucial role in preventive maintenance tasks. Traditional prediction methods have mostly focused on point prediction issues, neglecting the uncertain factors in the prediction task, thus failing to ensure the credibility of the prediction. In light of this, this paper focuses on improving the accuracy of point prediction models for RUL and interval prediction issues, proposing the introduction of multi-scale convolutional neural networks (MCNN), decomposed time-sequential linear layers (DL), and conformal quantile regression (CQR) techniques into the RUL prediction task of aero engines. The aim is to provide timely and accurate failure warnings for aero-engines, effectively ensure their reliability and safety, and reduce maintenance costs throughout their life cycle. In response to the limitations of current point prediction models in capturing the temporal features of life data, a MCNN-DL-based RUL prediction model is proposed to capture life data’s long-term trends and local variations for precise point predictions. Furthermore, an interval estimation approach for RUL is presented, which integrates the MCNN-DL model with CQR to account for prediction uncertainty. Finally, the method in this paper is verified using the commercial modular aero-propulsion system simulation (CMAPSS) dataset, and the results show that the method has achieved excellent results in both RUL point prediction and interval prediction tasks.
Prediction method for 4D trajectory of large fixed wing UAV under multi-layer convolution and bidirectional gating model
Authors: Ma Xin , Li Zixuan , Zheng Linxin , Lu Xikang
Published: September 2024

With the increase of low-altitude flight tasks, the importance of research on low-altitude flight safety and efficient operation has gradually become prominent. Therefore, it is necessary to try to establish a low-altitude airspace flight path pre-planning method based on 4D trajectory prediction, which can effectively support the above research. In order to improve the integrity, accuracy and reliability of the long-range trajectory prediction results of large fixed wing UAV (LFW UAV), based on the standard neural network as the basic concept to form a fusion model of improved convolutional neural network and bidirectional gated recurrent neural network. At the same time, the flight trajectory fitting preprocessing is added to build the completed multilayer cyclic convolutional improvement model (MCCI). The experimental results show that the MCCI model has obvious advantages in terms of prediction accuracy, deviation range and predictable duration when dealing with the LFW UAV 4D trajectory prediction problem, and better reflects the characteristics of 3D position and spatiotemporal elements. The comparative analysis shows that the error values of the MCCI model are smaller than those of the comparison prediction models in any dimension, and the prediction results have better fit and model performance.
A novel dynamic predictive maintenance framework for gearboxes utilizing nonlinear Wiener process
Authors: Dong Enzhi , Zhang Yu , Zhan Xianbiao , Bai Yongsheng , Cheng Zhonghua
Published: September 2024

In the context of advancing industrial automation, gearboxes, as pivotal components in power transmission systems, have a direct bearing on the operational efficiency and safety of the entire machinery. This study introduces a novel dynamic predictive maintenance (PdM) framework for gearboxes using a nonlinear Wiener process. Comprehensive experiments validate the framework, demonstrating significant reductions in maintenance costs and improvements in reliability. First, a full-life degradation experiment was executed on the gearbox, leveraging the root mean square value of the vibration signal as an indicator of system degradation. Subsequently, the signals from four vibration sensors were synthesized and normalized through kernel principal component analysis, thereby enabling a more nuanced representation of the gearbox’s degradation profile. The degradation trajectory was then modeled using a nonlinear Wiener process framework. The Wiener process’s parameters and state variables were iteratively refined utilizing an online filtering algorithm grounded in Bayesian inference. This facilitated the derivation of the probability density function for the remaining useful life (RUL), thereby enabling a robust prediction of the gearbox’s RUL. Finally, to minimize maintenance costs per unit of time, an optimization model for dynamic maintenance decision-making was formulated. The optimal maintenance timing was ascertained by solving this model. The empirical findings of this investigation demonstrate the efficacy of the proposed approach in executing dynamic PdM for gearboxes. This research endeavors to furnish novel theoretical underpinnings and pragmatic directives for the field of PdM in the context of gearboxes.
Hive-shaped carbon nanotubes coated with MoSe2 as an electrochemical sensor for cholesterol
Authors: Hu Lei , Huang Yu-Chiao , Huang Yung-Jui , Lin Pao-Hung , Wang Huan-Chun , Lin Chung-Kuang , Lee Kuei-Yi
Published: September 2024

The study utilized transition metal chalcogenide, molybdenum diselenide (MoSe2), for application in the field of bioelectrochemical sensing. The MoSe2 was combined with carbon nanotubes (CNTs) by chemical vapor deposition to enhance the specific surface area and improve the detection sensitivity. To further increase the contact area between the electrolyte and the electrode, photolithography techniques were employed to fabricate hive-shaped CNTs, thereby enhancing the specific surface area. Next, cholesterol oxidase (ChOx) was coated onto the electrode material, creating a cholesterol biosensor. Cyclic voltammetry was utilized to detect the concentration of cholesterol. The experiment involved segmented testing for cholesterol concentrations ranging from 0 μM to 10 mM. Excellent sensitivity, low detection limits, and high accuracy were achieved. In the cholesterol concentration range of 0 μM–100 μM, the experiment achieved the highest sensitivity of 4.44 μAμM

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cm−2. Consequently, all data indicated that ChOx/MoSe2/CNTs functioned as an excellent cholesterol sensor in the study.
Unconventional free fall measurements of g: involving the Pythagorean Theorem and inverse tangent function
Authors: Pili Unofre B
Published: September 2024

The current work presents unconventional but instructionally useful approaches to data analysis and modelling that allow for measurements of the acceleration due to gravity, g, using free-falling motion and the popular Tracker software. The two techniques detailed in this article illustrate the employability of the Pythagorean Theorem and the inverse tangent function in modelling free-falling motion that likewise, expectedly, permit for the determination of g. These two mathematical concepts are brought to relevance by strategically situating the origin of the coordinate system at an appropriate point. The models returned values of the gravitational acceleration that are comparable to that by the traditional technique, the one directly based on the vertical position-time data. Additionally, the unconventional free-fall data analyses presented in this paper suggest extra and insightful activities for the students, exercises on a notably less-automated nonlinear curve fitting on a spreadsheet (MS Excel) at most. Ultimately, by applying familiar mathematical concepts associated with a right triangle to nontraditional contexts like free-fall, this laboratory or lecture activity is perceived to spark greater interest of the students and enhance learning by unifying theory and experimental data.
Cronpes: time measurement device suitable for teaching experimental physics in Brazil
Authors: Bulla M A , Oliviera T , Franco M K K D , Yokaichiya F
Published: September 2024

Several public schools and also universities in Brazil have few or none financial resources to acquire certain equipment for teaching physics. Nevertheless, it is extremely important that institutions, schools and universities offer laboratory conditions for the students, mainly in engineering courses, in order to get the first contact with physics concepts in practice. For this purposes, it was proposed to develop a simple construction, low-cost and easy maintenance photogate (Cronpes) device, so that teachers, technicians and even students from the basic and high education network can build them for their schools, institutions and universities, thus improving the quality of teaching physics. This study aims to implement a photogate Esp32 microcontroller based programmed in MicroPython with good resolution, accuracy and user friendly in order to apply in experiments like simple pendulum, spring oscillations and conservation of mechanical energy. The main focus of this research was to demonstrate, through the development of Cronpes, that we can create solutions for educational laboratories, in a viable, creative and inexpensive way.
Effect of atomic layer deposition process parameters on TiN electrode for Hf0.5Zr0.5O2 ferroelectric capacitor
Authors: Li Hongbo , Zhang Jian , Guo Chongyong , Liu Yuanya , Liu Chunyan , Wang Yu , Li Jianjun , Yuan Hui , Jin Xingcheng
Published: September 2024

Hf0.5Zr0.5O2 (HZO), an innovative and exceptional ferroelectric material, exhibits remarkably high sensitivity, making it particularly vulnerable to electrode effect. Titanium nitride (TiN) is a commonly employed as electrode material in the complementary metal–oxide–semiconductor process. Optimizing the process parameters of preparing TiN film can alter matching degree with HZO capacitor, so as to find the optimal parameters of TiN process to improve ferroelectric property of HZO. In this study, the impact of key process parameters in atomic layer deposition (ALD) TiN, including cycle number, TiCl4 and NH3 pulse time, process temperature (T
p) on film thickness, crystalline phases of TiN, square resistivity (R
s), surface average roughness (R
a) and the root-mean-square roughness (R
q) of TiN film are comprehensively investigated. Through optimization, ∼10 nm ALD TiN film can achieve excellent uniformity of 0.43%, low R
s of 286.9 Ω/□, improved R
a and R
q of 1.82 Å and 2.28 Å. The results show that the maximum 2 times remnant polarization (2P
r) of the HZO ferroelectric capacitor with optimized TiN electrodes can reach 35.17 µC cm−2, and the switching cycle endurance exceeds 8 × 107.
The effect of temperature on the electrical characteristics of zigzag and armchair black phosphorus based 2D MOSFET
Authors: Majumder Tanmoy , Mukherjee Chandrima , Dasgupta Sudeb , Chakraborty Udayan , Das Narottam , Bhattacharjee Abhishek
Published: September 2024

A first time comparative study of the thermal dependence of vital electrical characteristics of two-dimensional metal-oxide-semiconductor field-effect transistors based on black phosphorus for both zigzag and armchair orientations is presented in this paper. It is seen that a higher in-plane thermal conductivity in zigzag direction results in a much better on state current performance which comes at the cost of orders of magnitude increase in gate leakage and a reduced on to off state current ratio. The effect of temperature on threshold voltage (V
TH), short channel effects like drain induced barrier lowering, subthreshold swing (SS), Schottky barrier height ΦSB and transconductance behavior in both zigzag and armchair orientations is thoroughly discussed and the inherent physical mechanisms resulting the variations are also presented. Though increase in temperature is found to deteriorate the SS and drain conductance but at the same time, it is found to improve the short channel performance of the devices under consideration.