bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitral Valve Surgery for Mitral Regurgitation Results in Reduced Left Ventricular Ejection Fraction in Barlow’s Disease as Compared with Fibro-Elastic Deficiency
Authors: Pype Lobke L. , Bertrand Philippe B. , Debonnaire Philippe , Dhont Sebastiaan , Hoekman Boukje , Paelinck Bernard P. , De Bock Dina , Heidbuchel Hein , Van Craenenbroeck Emeline M. , Van De Heyning Caroline M.
Published: February 2024

Surgical correction of severe mitral regurgitation (MR) can reverse left ventricular (LV) remodeling in patients with mitral valve prolapse (MVP). However, whether this process is similar to the case in Barlow’s Disease (BD) and Fibro-elastic Deficiency (FED) is currently unknown. The aim of this study is to evaluate post-operative LV reverse remodeling and function in patients with BD versus FED. In this study, 100 MVP patients (BD = 37 and FED = 63) with severe MR who underwent mitral valve surgery at three Belgian centers were retrospectively included. Transthoracic echocardiography was used to assess MR severity, LV volumes and function before surgery and 6 months thereafter. Baseline MR severity, LV ejection fraction (LVEF), indexed LV end-diastolic (LVEDVi) and end-systolic volumes (LVESVi) were not different between the groups. After a median follow-up of 278 days, there was a similar decrease in LVEDVi, but a trend towards a smaller decrease in LVESVi in BD compared to FED (−3.0 ± 11.2 mL/m2 vs. −5.3 ± 9.0 mL/m2; p = 0.154). This resulted in a significantly larger decrease in LVEF in BD (−8.3 ± 9.6%) versus FED (−3.9 ± 6.9%) after adjusting for baseline LVEF (p < 0.001) and type of surgical intervention (p = 0.01). These findings suggest that LV (reverse) remodeling in BD could be affected by other mechanisms beyond volume overload, potentially involving concomitant cardiomyopathy.
Short- and Long-Term Outcomes of Neoadjuvant Chemoradiotherapy Followed by Pancreatoduodenectomy in Elderly Patients with Resectable and Borderline Resectable Pancreatic Cancer: A Retrospective Study
Authors: Suto Hironobu , Fuke Takuro , Matsukawa Hiroyuki , Ando Yasuhisa , Oshima Minoru , Nagao Mina , Takahashi Shigeo , Shibata Toru , Yamana Hiroki , Kamada Hideki , Kobara Hideki , Okuyama Hiroyuki , Kumamoto Kensuke , Okano Keiichi
Published: February 2024

Background: The efficacy of neoadjuvant chemoradiotherapy (NACRT) followed by pancreatoduodenectomy (PD) in elderly patients with pancreatic ductal adenocarcinoma (PDAC) remains unclear. Methods: This retrospective analysis of prospectively collected data examined the effect of NACRT followed by PD in elderly patients with PDAC. A total of 112 patients with resectable (R-) and borderline resectable (BR-) PDAC, who were planned for PD and received NACRT between 2009 and 2022, were assessed. Changes induced by NACRT, surgical outcomes, nutritional status, renal and endocrine functions, and prognosis were compared between elderly (≥75 years, n = 43) and non-elderly (<75 years, n = 69) patients over two years following PD. Results: Completion and adverse event rates during NACRT, nutritional status, renal function, endocrine function over two years postoperatively, and prognosis did not significantly differ between the two groups. Low prognostic index after NACRT and the absence of postoperative adjuvant chemotherapy may be adverse prognostic indicators for elderly patients undergoing NACRT for R- and BR-PDAC. Conclusions: Despite a higher incidence of postoperative complications, NACRT followed by PD can be safely performed in elderly patients, resulting in a prognosis similar to that in non-elderly patients.
Using an Interpretable Amino Acid-Based Machine Learning Method to Enhance the Diagnosis of Major Depressive Disorder
Authors: Ho Cyrus Su Hui , Tan Trevor Wei Kiat , Khoe Howard Cai Hao , Chan Yee Ling , Tay Gabrielle Wann Nii , Tang Tong Boon
Published: February 2024

Background: Major depressive disorder (MDD) is a leading cause of disability worldwide. At present, however, there are no established biomarkers that have been validated for diagnosing and treating MDD. This study sought to assess the diagnostic and predictive potential of the differences in serum amino acid concentration levels between MDD patients and healthy controls (HCs), integrating them into interpretable machine learning models. Methods: In total, 70 MDD patients and 70 HCs matched in age, gender, and ethnicity were recruited for the study. Serum amino acid profiling was conducted by means of chromatography-mass spectrometry. A total of 21 metabolites were analysed, with 17 from a preset amino acid panel and the remaining 4 from a preset kynurenine panel. Logistic regression was applied to differentiate MDD patients from HCs. Results: The best-performing model utilised both feature selection and hyperparameter optimisation and yielded a moderate area under the receiver operating curve (AUC) classification value of 0.76 on the testing data. The top five metabolites identified as potential biomarkers for MDD were 3-hydroxy-kynurenine, valine, kynurenine, glutamic acid, and xanthurenic acid. Conclusions: Our study highlights the potential of using an interpretable machine learning analysis model based on amino acids to aid and increase the diagnostic accuracy of MDD in clinical practice.
Re-Do Plastic Reconstruction for Locally Advanced and Recurrent Colorectal Cancer Following a beyond Total Mesorectal Excision (TME) Operation—Key Considerations
Authors: Giannas Emmanuel , Kavallieros Konstantinos , Nanidis Theodoros , Giannas John , Tekkis Paris , Kontovounisios Christos
Published: February 2024

Innovation in surgery and pelvic oncology have redefined the boundaries of pelvic exenteration for CRC. However, surgical approaches and outcomes following repeat exenteration and reconstruction are not well described. The resulting defect from a second beyond Total Mesorectal Excision (TME) presents a challenge to the reconstructive surgeon. The aim of this study was to explore reconstructive options for patients undergoing repeat beyond TME for recurrent CRC following previous beyond TME and regional reconstruction. MEDLINE and Embase were searched for relevant articles, yielding 2353 studies. However, following full text review and the application of the inclusion criteria, all the studies were excluded. This study demonstrated the lack of reporting on re-do reconstruction techniques following repeat exenteration for recurrent CRC. Based on this finding, we conducted a point-by-point discussion of certain key aspects that should be taken into consideration when approaching this patient cohort.
Obsessive–Compulsive Disorder as an Epiphenomenon of Comorbid Bipolar Disorder? An Updated Systematic Review
Authors: de Filippis Renato , Aguglia Andrea , Costanza Alessandra , Benatti Beatrice , Placenti Valeria , Vai Eleonora , Bruno Edoardo , De Berardis Domenico , Dell’Osso Bernardo , Albert Umberto , De Fazio Pasquale , Amore Mario , Serafini Gianluca , Ghaemi Nassir S. , Amerio Andrea
Published: February 2024

Background: Bipolar disorder (BD) and obsessive–compulsive disorder (OCD) comorbidity is an emerging condition in psychiatry, with relevant nosological, clinical, and therapeutic implications. Methods: We updated our previous systematic review on epidemiology and standard diagnostic validators (including phenomenology, course of illness, heredity, biological markers, and treatment response) of BD-OCD. Relevant papers published until (and including) 15 October 2023 were identified by searching the electronic databases MEDLINE, Embase, PsychINFO, and Cochrane Library, according to the PRISMA statement (PROSPERO registration number, CRD42021267685). Results: We identified 38 new articles, which added to the previous 64 and raised the total to 102. The lifetime comorbidity prevalence ranged from 0.26 to 27.8% for BD and from 0.3 to 53.3% for OCD. The onset of the two disorders appears to be often overlapping, although the appearance of the primary disorder may influence the outcome. Compared to a single diagnosis, BD-OCD exhibited a distinct pattern of OC symptoms typically following an episodic course, occurring in up to 75% of cases (vs. 3%). Notably, these OC symptoms tended to worsen during depressive episodes (78%) and improve during manic or hypomanic episodes (64%). Similarly, a BD course appears to be chronic in individuals with BD-OCD in comparison to patients without. Additionally, individuals with BD-OCD comorbidity experienced more depressive episodes (mean of 8.9 ± 4.2) compared to those without comorbidity (mean of 4.1 ± 2.7). Conclusions: We found a greater likelihood of antidepressant-induced manic/hypomanic episodes (60% vs. 4.1%), and mood stabilizers with antipsychotic add-ons emerging as a preferred treatment. In line with our previous work, BD-OCD comorbidity encompasses a condition of greater nosological and clinical complexity than individual disorders.
Stereotactic Navigation-Assisted Laparoscopic Resection of Challenging Low Pelvic Tumors: A Case Series
Authors: Piozzi Guglielmo Niccolò , Kwak Jung-Myun , Kim Ji-Seon , Baek Se-Jin , Kim Jin , Kim Seon-Hahn
Published: February 2024

(1) Introduction: The laparoscopic approach to low pelvic tumors is challenging and hindered by suboptimal tumor visualization and dissection, with possible oncological failure. Stereotactic navigation provides real-time image guidance that may optimize safety, accuracy, and precision when dissecting challenging low pelvic tumors. (2) Methods: Preoperative CT images were acquired with eight skin-fixed fiducials and loaded into a navigation system. A patient tracker was mounted on the bed side. Patient-to-image paired point registration was performed, and an instrument tracker was mounted on a laparoscopic instrument and calibrated for instrument tracking. Surgical operations were performed with real-time stereotactic navigation assistance. (3) Results: Three patients underwent stereotactic navigation surgery. Fiducial registration errors were good to optimal (±1.9, ±3.4, and ±3.4 mm). Lesions were easily identified and targeted with real-time navigation. Surgeries were uneventful. Histopathology examinations identified one retro-rectal schwannoma, one lateral pelvic recurrence from rectal adenocarcinoma, and one advanced anal canal carcinoma. No navigation-related complications, readmissions, or postoperative mortalities were observed. (4) Conclusions: The application of laparoscopic stereotactic navigation surgery to complex low pelvic tumors is feasible and could impact oncological surgical quality by enabling tumor targeting and ensuring resection margins. Further wider series are needed to confirm stereotactic navigation’s impact on challenging low pelvic tumors.
Factors Associated with Nutritional Risk Assessment in Critically Ill Patients Using the Malnutrition Universal Screening Tool (MUST)
Authors: Díaz Chavarro Blanca Cecilia , Molina-Recio Guillermo , Assis Reveiz Jorge Karim , Romero-Saldaña Manuel
Published: February 2024

Background: Malnutrition is an underdiagnosed condition that negatively affects the clinical outcomes of patients, being associated with an increased risk of adverse events, increased hospital stay, and higher mortality. Therefore, nutritional assessment is a required and necessary process in patient care. The objective of this study was to identify the factors associated with nutritional risk by applying the Malnutrition Universal Screening Tool (MUST) scale in a population of critically ill patients. Methods: This was an observational, analytical, and retrospective study. Sociodemographic, clinical, hematological, and biochemical variables and their relationship with nutritional risk and mortality were analyzed. Results: Of 630 patients, the leading cause of admission was pathologies of the circulatory and respiratory system (50%); 28.4% were at high nutritional risk; and mortality was 11.6% and associated with nutritional risk, hemoglobin, and plasma urea nitrogen. Conclusions: The presence of gastrointestinal symptoms and the type of nutritional support received during hospitalization could increase the likelihood of presenting a medium/high nutritional risk, while polycythemia reduced this probability. An associative model was found to determine nutritional risk with an adequate specificity and diagnostic validity index.
Essential and Non-Essential Elemental Composition and Health Risks in Pacific Sardine in the Northwest Pacific Ocean
Authors: Leng Tiantian , Liu Bilin , Xie Jingqian , Zou Leilei , Lu Dongqi
Published: February 2024

Pacific sardine (Sardinops sagax) in the northwest Pacific Ocean (NPO) not only preserve the equilibrium of the NPO food chain, but also serve as a source of nutrition for humans. In order to evaluate the levels of various elements in S. sagax, we collected specimens from NWP waters and ascertained the quantities of four macronutrients, nine essential trace elements, and twelve non-essential trace elements. The factors (fatness, sex, sexual maturity, body length, body weight, and age) influencing the concentration were investigated, and the correlations of trace elements were examined. Additionally, the Estimated Daily Intake (EDI) approach and the Target Hazard Quotient (THQ) methodology were used to assess contamination levels and associated consumption risks. The results revealed that the macronutrient content (54–10,500 mg kg−1) was higher than the necessary trace elements (0–488 mg kg−1) and the non-essential trace elements (0–448 mg kg−1), and most of the elements showed positive correlation with each other. Almost all of the element concentrations were below the maximum permitted levels (MPLs) recommended by the FAO/WHO, except for As and Cd. The factors, including fatness, sexual maturity, body length, body weight, and age, showed a negative correlation with most of the trace elements. The outcomes of the stepwise regression analysis showed that sex and stage of sexual maturation were the principal biological factors influencing elemental content. The risk assessment and standard dietary intake levels indicated that the potential health issues associated with the consumption of S. sagax were negligible.
Numerical Simulation of Seakeeping Performance of a Barge Using Computational Fluid Dynamics (CFD)-Modified Potential (CMP) Model
Authors: Nam Seol , Park Jong-Chun , Park Jun-Bum , Yoon Hyeon Kyu
Published: February 2024

This paper explains the evaluation process of seakeeping performance for small vessels using a CFD-modified potential (CMP) model, a hybrid simulation model that modifies the damping ratio with computational fluid dynamics (CFD) after analyzing ship motion based on the linear potential theory. From the result of the motion analysis using the CMP model, the seakeeping performance of a small vessel (a barge here) was evaluated on the basis of the single significant amplitude (SSA) under the sea states 2~4. The results of the motion RAOs and seakeeping performance evaluation were verified through comparison with the results obtained by performing model tests and potential flow programs only. In all sea states, the relative errors (compared to the experiment) of roll motion using the CMP model were relatively small compared to the results using the potential flow program and tended to decrease more as the sea state increased. On the other hand, the results of pitch motion using the CMP model were underestimated in all sea states compared to the experiment. However, it is seen that they are relatively closer to the experiment compared to the results using a potential flow program only.
“Putin’s War of Choice”: U.S. Propaganda and the Russia–Ukraine Invasion
Authors: Hyzen Aaron , Van den Bulck Hilde
Published: February 2024

The Russian invasion of Ukraine on 24 February 2022 ignited propaganda efforts from the U.S. executive branch of government and the U.S. media, as the country tried to position itself towards the war not just in the eyes of its citizens but of the entire world as part of its geopolitical power position. A comparative quantitative and qualitative analysis of official U.S. communications and U.S. partisan media coverage in the first week of the invasion aims to uncover how the U.S. government set the agenda and framed the events, and to what extent the media copied or diverged from this agenda-setting and framing. The results suggest a narrow focus and distinct framing on the part of the U.S. government, partly taken over by partisan media. The latter also touched on other topics that fit media logic and provided some counter-frames in line with their ideological positions, yet overall confirmed the dominant framing of the war as unjust, unprovoked and premeditated, as Putin’s choice, and the position of the U.S. as the leader of the free world and defender of democracy.
Diagnostic Accuracy of Fecal Calprotectin in Discriminating Organic-Inflammatory Gastrointestinal Diseases and Functional Gastrointestinal Disorders in Older Patients
Authors: Gallo Antonella , Covino Marcello , Baroni Silvia , Camilli Sara , Ibba Francesca , Andaloro Silvia , Agnitelli Maria Chiara , Rognoni Fiammetta Maria , Landi Francesco , Montalto Massimo
Published: February 2024

Fecal calprotectin (FC) has been largely recognized as a surrogate marker of intestinal neutrophilic inflammation, very reliable in distinguishing between inflammatory bowel diseases and functional gastrointestinal (GI) disorders. Aging has been suggested to influence FC results and their diagnostic accuracy; however, no studies are specifically targeted on this focus. In a retrospective study, we evaluated the eventual age-differences of the diagnostic accuracy of FC in discriminating between organic-inflammatory GI diseases and functional GI disorders. In 573 younger and 172 older (≥65 years) subjects undergoing an FC assay, we found that the latter showed higher median FC values, 72 (25–260) µg/g vs. 47 (25–165) µg/g (p < 0.01). Younger patients were more commonly affected by IBDs, while colorectal cancer and high-risk polyps, infective colitis, and diverticular disease represented the most common findings in the older subgroup. However, the estimated optimum FC threshold in discriminating between organic-inflammatory GI diseases and functional GI disorders was quite similar between the two groups (109 μg/g for the younger subgroup and 98 μg/g for the older subgroup), maintaining a very high specificity. In conclusion, we show that FC also represents a very specific test for intestinal inflammation in older patients, at similar threshold levels to younger subjects.
Determinants of Behavioral Intention to Use Digital Payment among Indian Youngsters
Authors: Hasan Arif , Sikarwar Priyanka , Mishra Arun , Raghuwanshi Sandeep , Singhal Abhishek , Joshi Astha , Singh Prashant Raj , Dixit Abhilasha
Published: February 2024

In the current study, we sought to construct an integrated model to identify various elements and evaluate the impact of these identified factors on customers’ behavioral intention to use or not use specific M-wallets for payment. To this end, we proposed and validated a conceptual model. In all, 600 questionnaires were distributed, and 482 responses were deemed usable. Structural equation modeling was used to demonstrate the stability of the proposed model and to test the research hypotheses. Perceived value, trust, compatibility, and social influence were all found to have a substantial influence on behavioral intention; however, consumers are less likely to use an M-wallet on the basis of perceived enjoyment. We also found that trust, followed by compatibility, has a stronger influence on customers’ behavioral intentions in the context of M-payments. This study only included six M-wallets and was restricted to a certain age group in a single city. Understanding the many characteristics of behavioral intention can help M-wallet providers gain consumer trust and increase the frequency with which consumers use M-wallets for M-payments. The findings suggest that M-wallet service providers should consider and manage all influencing elements as proactive strategies for M-wallet intention. This strategy can be used to create an M-wallet-user behavioral intention model that will assist enterprises/companies in managing the establishment of their users’ behavioral intentions.
Algorithm-Based Low-Frequency Trading Using a Stochastic Oscillator and William%R: A Case Study on the U.S. and Korean Indices
Authors: Paik Chan Kyu , Choi Jinhee , Vaquero Ivan Ureta
Published: February 2024

Using stochastics in stock market analysis is widely accepted for index estimation and ultra-high-frequency trading. However, previous studies linking index estimation to actual trading without applying low-frequency trading are limited. This study applied William%R to the existing research and used fixed parameters to remove noise from stochastics. We propose contributing to stock market stakeholders by finding an easy-to-apply algorithmic trading methodology for individual and pension fund investors. The algorithm constructed two oscillators with fixed parameters to identify when to enter and exit the index and achieved good results against the benchmark. We tested two ETFs, SPY (S&P 500) and EWY (MSCI Korea), from 2010 to 2022. Over the 12-year study period, our model showed it can outperform the benchmark index, having a high hit ratio of over 80%, a maximum drawdown in the low single digits, and a trading frequency of 1.5 trades per year. The results of our empirical research show that this methodology simplifies the process for investors to effectively implement market timing strategies in their investment decisions.
Spatiotemporal Evolution and Prediction of Land Use and Carbon Stock in Shanghai
Authors: Xu Di , Yu Chuanqing , Lin Wenpeng , Yao Jiang , Zhou Wenying
Published: February 2024

Soil organic carbon (SOC) constitutes a critical component of carbon reservoirs within terrestrial ecosystems. The ramifications of urban land use transitions on SOC dynamics, particularly in rapidly urbanizing regions such as Shanghai, remain insufficiently elucidated. This investigation synergizes a predictive land use change model (Logistic-CA-Markov) with an ecosystem service quantification framework (InVEST), aiming to delineate the interplay between SOC variability and Land Use and Land Cover Change (LUCC) under natural development and ecological protection scenarios. Empirical observations from 2010 to 2020 reveal a contraction in Shanghai’s agricultural land of 34,912.76 hectares, juxtaposed with an expansion of urban built-up areas of 36,048.24 hectares. Projections for 2030 under an ecological protection scenario indicate a moderated urban sprawl, reducing built-up area expansion by 13,518 hectares relative to the natural development scenario. Notably, the net carbon sequestration capacity of Shanghai is anticipated to diminish by approximately 0.418 million tons between 2020 and 2030. This trend is observed under both considered scenarios, forecasting a cumulative reduction in SOC stocks exceeding 1 million tons by 2030. The natural development pathway portends a more pronounced and accelerated depletion of SOC reserves. Although ecological conservation measures show the potential to decelerate this loss, they appear insufficient to reverse the ongoing decline in SOC stocks. This study advocates for strategic urban planning interventions focused on constraining the growth of building densities and augmenting the preservation and management of eco-lands. Such measures are imperative for bolstering Shanghai’s carbon sequestration capacity.
Agency within Neighborhoods: Multi-Scalar Relations between Urban Form and Social Actors
Authors: Geddes Ilaria , Chatzichristou Christakis , Charalambous Nadia , Ricchiardi Ana
Published: February 2024

This research provides an abstract representation of neighborhoods, accounting for the actors involved in the process of their formation and transformation as local entities embedded in a complex yet specific configuration of historical, social, structural, and political contexts. The analysis uses a conceptual framework combining Assemblage Theory and Actor–Network Theory to examine how both human and non-human actors or agents interact and consequently exert an impact on three different neighborhoods in Limassol, Cyprus. The methodology combines both qualitative as well as quantitative approaches. The tools used include space syntax, land use, and building typology, descriptive statistics of social factors, a photographic survey, observation of the built environment’s expressive features, and archival research of press articles. The findings reveal the extent to which global factors, such as colonialism and the mobility of wealthy populations from former Soviet countries, have an impact on the social makeup and expressive features of the environment, while local factors, such as block size and housing typology, have a strong impact on the use of public space. Furthermore, more complex networks may exhibit structural resilience or adaptability but may be, at the same time, more sensitive to varying and conflicting interests.
Effects of Seed Size and Cache Density on the Seed Fate of Quercus wutaishanica Mediated by Rodents
Authors: Cheng Jiming , Zhang Min , Yan Xingfu
Published: February 2024

Animal-mediated seed dispersal is very important for plant population regeneration and the stability of forest ecosystems. Seed size and cache density are important factors for seed dispersal, but we still know little about seed size selection at different cache densities. Here, we conducted field experiments in a Larix principis-rupprechtii plantation in the Liupan Mountains in Ningxia province to investigate the effects of tag-marked Quercus wutaishanica seeds of different sizes and cache densities on predation and the scatter-hoarding behavior of rodents. The results showed lower proportions of intact in situ (IIS) and eaten in situ (EIS) large seeds than small seeds at all levels of cache density, with the exception of IIS seeds at a 6.25 seed·m−2 cache density. A higher proportion of small seeds were eaten after removal (EAR), but a higher proportion of large seeds were scatter-hoarded (SH) by rodents at most cache densities. Furthermore, rodents preferentially removed large seeds farther away for eating or scatter-hoarding. The IIS and EIS proportions of both large and small seeds declined, but the proportion of the two types of seeds that were EAR fluctuated, increasing with increasing cache density. Rodents preferred to increase the proportion of scatter-hoarding of large seeds with increasing cache density, whereas the proportion of scatter-hoarding of small seeds was maximized at a cache density of 6.25 seed·m−2. Both the eaten distance after removal (EDAR) and scatter-hoarded distance (SHD) increased with increasing cache density. These results suggest that large seeds are more likely to be scatter-hoarded and removed to longer distances than small ones. Rodents tended to reduce the seed proportion of EIS seeds and increased the proportion of seeds EAR and SH, and accordingly increased EDAR and SHD with increasing cache density. This study provides some scientific basis for animal-mediated seed dispersal.
Effectiveness of Virtual Reality on Postoperative Pain, Disability and Range of Movement after Knee Replacement: A Systematic Review and Meta-Analysis
Authors: Esteban-Sopeña Jara , Beltran-Alacreu Hector , Terradas-Monllor Marc , Avendaño-Coy Juan , García-Magro Nuria
Published: February 2024

Postoperative pain after knee arthroplasty (TKA) is a reality that continues to be experienced today. Recently, virtual reality (VR) has demonstrated effectiveness in the management of pain. Our aim was to review the original controlled trials evaluating the effectiveness of VR for pain management and quality of life after TKA. Six databases were searched for articles published from inception to September 2023, following (PRISMA) guidelines. The methodological quality was assessed using the Risk of Bias tool for Randomized Trials (ROB2). Five RCTs were included in the systematic review, and four of them in the meta-analysis. The effectiveness of VR for short term pain relief was superior compared to the control (MD = −0.8 cm; CI 95%: −1.3 to −0.4; p < 0.001). VR showed a greater effect on the secondary outcomes of WOMAC (MD = −4.6 points; CI 95%: −6.5 to −2.6, p < 0.001) and the HSS scale (MD = 6.5 points; CI 95%: 0.04 to 13.0, p = 0.049). However, no differences were found in the effect on the ROM between groups (MD = 3.4 grades; CI 95%: −6.0 to 12.8, p = 0.48). Our findings suggest that the use of virtual reality during the postoperative period could be an effective non-pharmacological therapy in relieving acute pain, compared to a control intervention, with a very low degree of certainty according to the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE). However, the low methodological quality of the articles limits our findings.
Identifying Key Issues in Integration of Autonomous Ships in Container Ports: A Machine-Learning-Based Systematic Literature Review
Authors: Hirata Enna , Hansen Annette Skovsted
Published: February 2024

Background: Autonomous ships have the potential to increase operational efficiency and reduce carbon footprints through technology and innovation. However, there is no comprehensive literature review of all the different types of papers related to autonomous ships, especially with regard to their integration with ports. This paper takes a systematic review approach to extract and summarize the main topics related to autonomous ships in the fields of container shipping and port management. Methods: A machine learning method is used to extract the main topics from more than 2000 journal publications indexed in WoS and Scopus. Results: The research findings highlight key issues related to technology, cybersecurity, data governance, regulations, and legal frameworks, providing a different perspective compared to human manual reviews of papers. Conclusions: Our search results confirm several recommendations. First, from a technological perspective, it is advised to increase support for the research and development of autonomous underwater vehicles and unmanned aerial vehicles, establish safety standards, mandate testing of wave model evaluation systems, and promote international standardization. Second, from a cyber–physical systems perspective, efforts should be made to strengthen logistics and supply chains for autonomous ships, establish data governance protocols, enforce strict control over IoT device data, and strengthen cybersecurity measures. Third, from an environmental perspective, measures should be implemented to address the environmental impact of autonomous ships. This can be achieved by promoting international agreements from a global societal standpoint and clarifying the legal framework regarding liability in the event of accidents.
Experimental and Numerical Study on Chloride Transport in Unsaturated Concrete: Highlighting Temperature, Humidity, and Mineral Admixtures
Authors: Du Zhantao , Jin Zuquan , Li Shicai , Xue Huan , Zhao Rui
Published: February 2024

Chloride transport within concrete is critical for the durability of reinforced concrete structures; however, its diffusion under the coupling action of temperature and humidity has not been fully comprehended. Therefore, in this work, the coupling effects of temperature, relative humidity, and mineral admixtures on chloride transport in concrete were investigated through experimental and numerical simulation work. The results show that the chloride diffusion coefficient decreases with the decreased temperature and growth of relative humidity; however, the chloride concentration on the concrete surface is increased with the growth of temperature and relative humidity. Moreover, compounding about 15% fly ash (FA) and 30% granulated ground blast furnace slag (GGBS) to replace the cement is the most beneficial for improving the antichloride capacity of concrete, considering also the strength. In addition, the numerical simulation considering the coupled effect of temperature and relative humidity of chloride transport in concrete has good agreement with that of experimental results.
Effects of Shot Peening and Electropolishing Treatment on the Properties of Additively and Conventionally Manufactured Ti6Al4V Alloy: A Review
Authors: Okuniewski Wojciech , Walczak Mariusz , Szala Mirosław
Published: February 2024

This literature review indicates that the basic microstructure of Ti6Al4V is bimodal, consisting of two phases, namely α + β, and it occurs after fabrication using conventional methods such as casting, plastic forming or machining processes. The fabrication of components via an additive manufacturing process significantly changes the microstructure and properties of Ti6Al4V. Due to the rapid heat exchange during heat treatment, the bimodal microstructure transforms into a lamellar microstructure, which consists of two phases: α′ + β. Despite the application of optimum printing parameters, 3D printed products exhibit typical surface defects and discontinuities, and in turn, surface finishing using shot peening is recommended. A literature review signalizes that shot peening and electropolishing processes positively impact the corrosion behavior, the mechanical properties and the condition of the surface layer of conventionally manufactured titanium alloy. On the other hand, there is a lack of studies combining shot peening and electropolishing in one hybrid process for additively manufactured titanium alloys, which could synthesize the benefits of both processes. Therefore, this review paper clarifies the effects of shot peening and electropolishing treatment on the properties of both additively and conventionally manufactured Ti6Al4V alloys and shows the effect process on the microstructure and properties of Ti6Al4V titanium alloy.
Investigation into the Structure and Properties of Biochar Co-Activated by ZnCl2 and NaHCO3 under Low Temperature Conditions
Authors: Zhang Hao , Wei Zhaozhou , Xiong Deyuan , Wu Yao , Tong Menglong , Su Huiping , Zhang Zuoyuan , Liao Jian
Published: February 2024

Using sodium lignosulfonate as feedstock, ZnCl2 and NaHCO3 co-activated the hierarchical porous carbons (HPCs) were prepared by one-pot pyrolysis with different NaHCO3 dosages (0–4 g) and carbonization temperatures (400–600 °C). Subsequently, phosphotungstate (HPW) was supported with the resulting biochar for the α-pinene hydration reaction to produce α-terpineol. The optimum preparation conditions were determined according to the yield of α-terpineol. The formation mechanism and physicochemical properties of HPCs were analyzed through TG, SEM, XPS, XRD, FT-IR, and N2 adsorption–desorption isotherms. The results demonstrated that NaHCO3 underwent a two-step reaction which liberated a substantial quantity of CO2, thereby enhancing activated carbon’s macroporous and mesoporous structures. Simultaneously, NaHCO3 mitigated strong acid gas (HCl) emissions during ZnCl2 activation. Compared with AC450-4:8:0 prepared by ZnCl2 activation alone, the total pore volume of AC450-4:8:2 prepared by co-activation is increased from 0.595 mL/g to 0.754 mL/g and the mesopore rate from 47.7% to 77.8%, which is conducive to reducing the steric hindrance of the hydration reaction and improving the selectivity. Hydration experiments show that the selectivity of α-terpineol is 55.7% under HPW/AC450-4:8:2 catalysis, higher than 31.0% for HPW and 47.4% for HPW/AC450-4:8:0.
Quantitative Analysis of the Physical Properties of Ti6Al4V Powders Used in a Powder Bed Fusion Based on 3D X-ray Computed Tomography Images
Authors: Mao Yuyi , Hu Juan , Chen Qiang , Shen Xiaodong
Published: February 2024

The physical properties of Ti6Al4V powder affect the spreadability of the powder and uniformity of the powder bed, which had a great impact on the performance of built parts made by powder bed fusion technology. Micro-computed tomography is a well-established technique used to analyze the non-destructivity of the objects’ interior. Ti6Al4V powders were scanned with micro-CT to show the internal and external information of all the particles. The morphology, particle size distribution, hollow particle ratio, density, inclusion, and specific surface area of the powder samples were quantitatively characterized, and the relationship of flowability with these physical properties was analyzed in this work. The research results of this article showed that micro-CT is an effective way to characterize these items, and can be developed as a standard method of powder physical properties in the future.
A Novel Sandwich-Structured Phase Change Composite with Efficient Photothermal Conversion and Electromagnetic Interference Shielding Interface
Authors: Xu Jun , Li Yuanyuan , Zhou Zhangxinyu , Cheng Xiaomin
Published: February 2024

Stability and multifunctionality greatly extend the applications of phase change materials (PCMs) for thermal storage and management. Herein, CuS and Fe3O4 nanoparticles were successfully loaded onto cotton-derived carbon to develop a multifunctional interface with efficient photothermal conversion and electromagnetic interference (EMI) shielding properties. 1,3:2,4-di-(3,4-dimethyl) benzylidene sorbitol (DMDBS) and expanded graphite (EG) formed an organic/inorganic three-dimensional network framework to encapsulate 1-octadecanol (OD) by self-assembly. Finally, multifunctional shape-stabilized PCMs (SSPCMs) with the sandwich structure were prepared by the hot-press process. Multifunctional SSPCMs with high load OD (91%) had favorable thermal storage density (200.6 J/g), thermal stability, and a relatively wider available temperature range with improved thermal conductivity to support the thermal storage and management realization. Furthermore, due to the synergistic enhancement of two nanoparticles and the construction of the carbon network with cotton carbon and EG, highly efficient photothermal conversion (94.4%) and EMI shielding (68.9 dB average, X-band) performance were achieved at about 3 mm thickness, which provided the possibility of the multifunctional integration of PCMs. Conclusively, this study provides new insights towards integrating solar energy utilization with the comprehensive protection of related electronics.
Deformation Behavior and Microstructure of 6061 Aluminum Alloy Processed by Severe Plastic Deformation Using Biaxial Alternate Forging
Authors: Ha Seong-Ho , Shin Young-Chul
Published: February 2024

The deformation behavior and microstructure of 6061 aluminum alloy processed by severe plastic deformation (SPD) using biaxial alternate forging that can evaluate the forming limit and mechanical properties of alloys, simultaneously, were investigated in this study. A finite element (FE) analysis on the biaxial alternating forging process, considering the strain-hardening coefficient and forging pass of the material, was conducted. When the strain-hardening coefficient is 0, an average effective strain of 440% was found within a diameter of 4 mm in the core of the workpiece after eight passes, while it was 300% at the same pass number when the strain-hardening coefficient was 0.2. The average effective strain estimated from the FE analysis was about 264% after eight passes of forging, which is considered to be a level of SPD that significantly exceeds the elongation of the raw material. As a result of the tensile test according to the forging pass, after two passes, the strength of the material could be gradually improved without significant degradation of elongation. Even though a large strain of 264% was found after eight passes were applied, deformed grains and twins with no recrystallized structure in optical microstructures with different forging passes were found.
Design and Effect of Resonant Ultrasonic Vibration-Assisted Laser Cladding (R-UVALC) on AlCrFeMnNi High-Entropy Alloy
Authors: Mohsan Aziz Ul Hassan , Zhang Mina , Wang Dafeng , Wang Yishen , Zhang Jiahao , Zhou Yanyuan , Li Yifei , Zhao Su
Published: February 2024

The design of the resonant ultrasonic vibration-assisted laser cladding (R-UVALC) setup involved employing finite element analysis (FEA) to simulate the ultrasonic transducer, horn, and workpiece in a resonance state. The impact of R-UVALC on AlCrFeMnNi high-entropy alloys was assessed using various ultrasonic vibration amplitudes of 0, 5, 10, and 15 µm, with a constant frequency of 20 kHz. Ultrasonic vibrations reduced pores and cracks and increased the clad breadth, melt pool wetting angle, and laser-clad layer consistency. The columnar elongated grains in proximity to the substrate surface underwent a size reduction and transformed into grains with a more equiaxed shape with the utilization of ultrasonic vibrations at an amplitude of 5 µm. Laser cladding performed without ultrasonic vibrations yields two phases: face-centered cubic (FCC) and body-centered cubic (BCC). However, when the coating is exposed to ultrasonic vibrations with an amplitude of 5 µm, it forms a solitary body-centered cubic (BCC) phase. The microhardness tripled compared to the substrate, and the most significant microhardness value was achieved at 5 µm of ultrasonic vibration. The friction coefficient was assessed at an ambient temperature, revealing that an ultrasonic amplitude yields the lowest friction coefficient, demonstrating the excellent wear resistance properties of the coating. The analysis of the 3D surface profile of the wear indicates that the use of ultrasonic aid with a 5 µm amplitude leads to reduced depth of scars, and the primary wear mechanism observed is abrasive and oxidative wear with fewer grooves and debris. In addition, XPS analysis revealed the presence of metal components in an oxidized condition, suggesting that the wear process is oxidative in nature. Integrating the R-UVALC setup into a resonance state can significantly enhance the efficiency of the laser cladding process in the laser cladding field.
Multi-Scale Analysis of the Damage Evolution of Coal Gangue Coarse Aggregate Concrete after Freeze–Thaw Cycle Based on CT Technology
Authors: Xin Changhao , Yang Yu , Yang Mengze , Di Junzhen , Sun Yidan , Liang Pengfei , Wang Yaohong
Published: February 2024

This study utilized X-ray computed tomography (CT) technology to analyze the meso-structure of concrete at different replacement rates, using a coal gangue coarse aggregate, after experiencing various freeze–thaw cycles (F-Ts). A predictive model for the degradation of the elastic modulus of Coal Gangue coarse aggregate Concrete (CGC), based on mesoscopic damage, was established to provide an interpretation of the macroscopic mechanical behavior of CGC after F-Ts damage at a mesoscopic scale. It was found that after F-Ts, the compressive strength of concrete, with coal gangue replacement rates of 30%, 60%, and 100%, respectively, decreased by 33.76%, 34.89%, and 42.05% compared with unfrozen specimens. The results indicate that an increase in the coal gangue replacement rate exacerbates the degradation of concrete performance during the F-Ts process. Furthermore, the established predictive formula for elastic modulus degradation closely matches the experimental data, offering a reliable theoretical basis for the durability design of CGC in F-Ts environments.
The Microstructure and Thermal Conductive Behavior of Three-Dimensional Carbon/Carbon Composites with Ultrahigh Thermal Conductivity
Authors: Li Baoliu , Zhu Chenyu , Xu Huitao , Qin Yudan , Shan Changchun , Gao Fang , Guo Jianguang , Dong Zhijun , Li Xuanke
Published: February 2024

Carbon-based composite materials, denoted as C/C composites and possessing high thermal conductivity, were synthesized utilizing a three-dimensional (3D) preform methodology. This involved the orthogonal weaving of mesophase pitch-based fibers in an X (Y) direction derived from low-temperature carbonization, and commercial PAN-based carbon fibers in a Z direction. The 3D preforms were saturated with mesophase pitch in their raw state through a hot-pressing process, which was executed under relatively low pressure at a predetermined temperature. Further densification was achieved by successive stages of mesophase pitch impregnation (MPI), followed by impregnation with coal pitch under high pressure (IPI). The microstructure and thermal conductivity of the C/C composites were systematically examined using a suite of analytical techniques, including Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and PLM, amongst others. The findings suggest that the volumetric fraction of fibers and the directional alignment of the mesophase pitch molecules can be enhanced via hot pressing. The high graphitization degree of the mesophase pitch matrix results in an increased microcrystalline size and thus improved thermal conductivity of the C/C composite. Conversely, the orientation of the medium-temperature coal pitch matrix is relatively low, which compensates for the structural inadequacies of the composite material, albeit contributing minimally to the thermal conductivity of the resultant C/C composites. Following several stages of impregnation with mesophase pitch and subsequent impregnation with medium-temperature coal pitch, the 3D C/C composites yielded a density of 1.83 and 2.02 g/cm3. The thermal conductivity in the X (Y) direction was found to be 358 and 400 W/(m·K), respectively.
Research on the Hot Deformation Process of A100 Steel Based on High-Temperature Rheological Behavior and Microstructure
Authors: Sun Chaoyuan , Qin Yi , Liu Yang , Xiao Guiqian , Zhang Jiansheng , Zhou Jie
Published: February 2024

To obtain the optimal hot deformation process, the rheological and dynamic recrystallization behaviors of A100 steel were researched through isothermal compression tests. Firstly, a Hensel-Spittel constitutive model was established based on the stress–strain curves. Secondly, dynamic recrystallization percentage and grain size models were established to identify the necessary conditions for complete dynamic recrystallization. Finally, microstructural analysis was employed to validate the accuracy of the recrystallization model. The results indicate that the flow stress is highly sensitive to both the strain rate and the temperature, and the HS model demonstrates a high predictive accuracy, with a correlation coefficient of 0.9914. There exists a contradictory relationship between decreasing the average grain size and increasing the recrystallization percentage. The higher the percentage of dynamic recrystallization, the larger the average grain size tends to be. This situation should be avoided when devising the actual processing procedures. The optimal hot working processes for achieving complete dynamic recrystallization and a smaller average grain size are as follows: a strain equal to or greater than 0.6, a temperature between 1193 and 1353 K, and a strain rate between 0.1 and 1 s−1.