bluuebunny/crossref_metadata_2025 huggingface dataset:
Solving invex multitime control problems with first‐order PDE constraints via the absolute value exact penalty method
Authors: Antczak Tadeusz , Treanţă Savin
Published: August 2023

In this paper, a nonconvex multitime control problem with first‐order PDE constraints is considered. Then, we investigate the absolute value exact penalty function method which is used for solving the aforesaid control problem. Namely, in order to ensure the effective use of the absolute value exact penalty function method in the considered case, the most important property of any exact penalty function method, that is, exactness of the penalization, is analyzed in the case when the aforementioned method is applied for solving the considered multitime control problem with first‐order PDE constraints in which the functionals involved are nonconvex. Thus, the equivalence between an optimal solution of the aforementioned control problem and a minimizer of its associated unconstrained multitime control problem constructed in the used absolute value exact penalty function method is proved under appropriate invexity hypotheses.
Melt and solution processability of poly(butylene succinate‐dilinoleic succinate) copolymers modified with poly(ethylene glycol) using3Dprinting and electrospinning
Authors: Zarei Moein , Żwir Marek J. , Wiśniewska Ewa , Michalkiewicz Beata , El Fray Miroslawa
Published: August 2023

Fabrication of complex structures usually requires a combination of different advanced manufacturing techniques at different length scales. In this work, we discuss the structure‐properties relationship of recently developed biodegradable poly(butylene succinate‐dilinoleic succinate) (PBS‐DLS) copolymers modified with hydrophilic poly(ethylene glycol) (PEG) towards their processibility via 3D printing and electrospinning. Notably, filaments suitable for 3D printing with 1.75 mm diameter were fabricated directly from the reactor after the synthesis of copolymers through extruding polymer melt into a water bath thus overcoming the postprocessing. Two series of copolymers containing 60 wt% and 70 wt% of hard PBS content were synthesized using magnesium‐titanium butoxide as heterometallic catalyst. Differential scanning calorimetry indicated biphasic morphology with low‐glass transition temperature and high‐melting point, which were dependent from the PBS hard segments content. Crystallized copolymers exhibited distinct spherulitic morphology, but presence of crystallites has no adverse effect on warping or delamination of subsequent layers during 3D printing. Furthermore, these copolymers demonstrated also easy processability through electrospinning, yielding uniform nanofibers with diameters ranging from 400 to 600 nm. The addition of 5 wt% PEG to copolymers with higher hard segments content (70 wt%) increased the elasticity up to 830% and improved hydrophilicity of the copolymers. Overall, these findings together with the excellent cell viability of new materials highlight their potential for different applications, including the biomedical sector.
Polydicyclopentadiene toughened epoxy resin and its carbon fiber composites via sequential polymerization
Authors: Cheng Chao , Zhang Chenyu , Chen Zhengguo , Zhou Fei , Zhou Jinli , Sun Zeyu , Yu Muhuo
Published: August 2023

In this work, a dicyclopentadiene monomer/Grubbs 2 catalyst was added to a mixture of epoxy oligomers and methyl nadic anhydride to obtain a poly‐dicyclopentadiene (DCPD) modified epoxy cross‐linked network via sequential curing. The hybrid resin was used as a matrix for preparing carbon fiber composites. The results indicated that the addition of DCPD monomers significantly reduced the viscosity of the epoxy resin. The toughness and heat resistance of the co‐cured resin was improved without significant loss of strength, which was attributed to the high compatibility between epoxy and the modifier polymer. Regarding the composites, the flexural strength of the hybrid resin‐derived composite first increased and then diminished slightly. Meanwhile, the mode‐I interlaminar fracture toughness continued to increase with the increase of PDCPD content compared to the non‐modified composites. Generally, the change trend of the above properties in the composites was consistent with the change trend of the strength and toughness exhibited in the bulk resin with increasing PDCPD contents, while the change extent was inconsistent due to factors such as fiber volume content and interfacial bonding.

Highlights

The epoxy/PDCPD hybrid resin system was obtained via sequential curing.

The PDCPD as modifier can reduce the viscosity of the epoxy curing system.

The toughness and heat resistance of the PDCPD modified epoxy resin was improved.

The loss in flexural strength of the hybrid resin system was insignificant.

The GIC of the epoxy composites modified with PDCPD improved appreciably.
A study on the crystallization and melting of PLA nanocomposites with cellulose nanocrystals by DSC
Authors: Kang Homin , Kim Dae Su
Published: August 2023

Poly(lactic acid) (PLA)/cellulose nanocrystal (CNC) nanocomposites with 1 or 3 phr of CNC were prepared by melt mixing and compression molding then their % crystallinities as well as crystallization and melting behavior during the first heating/cooling/second heating process were investigated by differential scanning calorimetry (DSC). Isothermal crystallization at 80–130°C for 5 min was performed during the cooling process to see how the isothermal crystallization affects % crystallinity at 25°C. The % crystallinity at 25°C as well as the crystallization rate of the nanocomposite increased with CNC content and showed a maximum at the isothermal crystallization temperature of 105°C regardless of CNC content. The bimodal DSC melting peaks observed during the second heating process were considered due to the crystals with many defects (α′) and the crystals with more perfect structure (α), respectively. Isothermal crystallization kinetic analysis by Avrami equation showed that the Avrami exponents of the nanocomposites were about 1, meaning a rod‐ or disc‐shaped crystal growth mechanism. Improving the mechanical properties of the PLA/CNC nanocomposite would be possible because the % crystallinity at 25°C could be effectively increased by changing CNC content and cooling history.

Highlights

PLA/CNC nanocomposites.

Crystallization and melting behavior analysis of the nanocomposites by DSC.

Isothermal crystallization at 80–130°C for 5 min during cooling by DSC.

Crystallization degree was maximum for the isothermal crystallization at 105°C.

Isothermal crystallization kinetic analysis by Avrami equation.
The Cornbelt's Last Open Pollinated Corn: Agricultural extension and the origins of the hybrid corn seed industry
Authors: Curry Helen Anne
Published: August 2023

Societal Impact Statement

Agricultural extension is recognized as an important pathway for generating changes in individual farmers' practices and therefore broader patterns of production. In the United States, historical research has implicated extension work in transformations that privileged White farmers and wealthier operations over other producers and that fostered the industrialization and consolidation of farms. This article examines the work of one early 20th‐century extension agent and the demonstrations he used to teach farmers how to choose and keep corn seeds and to identify the best performing corn varieties for a particular location. This history can inform contemporary efforts to develop more socially and ecologically aware approaches to agricultural research, extension, and production by emphasizing the need for measures of success that align with community‐level objectives and for larger institutional structures that support and sustain such goals.

The article examines the histories of agricultural extension and crop development in the early 20th‐century United States. It discusses the role of farm demonstrations, including the participation of farmer‐breeders, in the development of spread of higher yielding corn varieties in the Midwestern states in the 1910s and 1920s. It highlights the emphasis placed on finding locally or regionally appropriate varieties in some early corn extension activities and dwells on the irony that these locally specific endeavors played a role in the development of universalized solutions.

The article examines and contextualizes an unusual archival document as an entry point into these histories: The Cornbelt's Last Open Pollinated Corn, a two‐volume work prepared by Martin Luther Mosher (1882–1982). Mosher was the first county agricultural extension agent in the state of Iowa and worked in extension until his retirement in 1950.

The article makes three main observations: (1) The Cornbelt's Last Open Pollinated Corn is best read as an agricultural demonstration; (2) The Cornbelt's Last Open Pollinated Corn is Mosher's attempt to grapple with the material legacies of his extension work in relation to the different agricultural life he idealized; and (3) Mosher's work exemplifies the complex relationships and expectations seen among breeders, seed companies, extension agents, and farmers in the early 20th‐century United States.

The article concludes that Mosher's work with open‐pollinated corn varieties offers insight into the importance of agricultural extension as a means of crop development and highlights the contingent nature of agricultural industrialization.
Reevaluation of bromodomain ligands targeting BAZ2A
Authors: Cazzanelli Giulia , Vedove Andrea Dalle , Parolin Eleonora , D'Agostino Vito Giuseppe , Unzue Andrea , Nevado Cristina , Caflisch Amedeo , Lolli Graziano
Published: August 2023

BAZ2A promotes migration and invasion in prostate cancer. Two chemical probes, the specific BAZ2‐ICR, and the BAZ2/BRD9 cross‐reactive GSK2801, interfere with the recognition of acetylated lysines in histones by the bromodomains of BAZ2A and of its BAZ2B paralog. The two chemical probes were tested in prostate cancer cell lines with opposite androgen susceptibility. BAZ2‐ICR and GSK2801 showed different cellular efficacies in accordance with their unequal selectivity profiles. Concurrent inhibition of BAZ2 and BRD9 did not reproduce the effects observed with GSK2801, indicating possible off‐targets for this chemical probe. On the other hand, the single BAZ2 inhibition by BAZ2‐ICR did not phenocopy genetic ablation, demonstrating that bromodomain interference is not sufficient to strongly affect BAZ2A functionality and suggesting a PROTAC‐based chemical ablation as an alternative optimization strategy and a possible therapeutic approach. In this context, we also present the crystallographic structures of BAZ2A in complex with the above chemical probes. Binding poses of TP‐238 and GSK4027, chemical probes for the bromodomain subfamily I, and two ligands of the CBP/EP300 bromodomains identify additional headgroups for the development of BAZ2A ligands.
Engineering gain‐of‐function mutants of a WW domain by dynamics and structural analysis
Authors: Lu Jin , Rahman Mohammad Imtiazur , Kazan I. Can , Halloran Nicholas R. , Bobkov Andrey A. , Ozkan S. Banu , Ghirlanda Giovanna
Published: August 2023

Proteins gain optimal fitness such as foldability and function through evolutionary selection. However, classical studies have found that evolutionarily designed protein sequences alone cannot guarantee foldability, or at least not without considering local contacts associated with the initial folding steps. We previously showed that foldability and function can be restored by removing frustration in the folding energy landscape of a model WW domain protein, CC16, which was designed based on Statistical Coupling Analysis (SCA). Substitutions ensuring the formation of five local contacts identified as “on‐path” were selected using the closest homolog native folded sequence, N21. Surprisingly, the resulting sequence, CC16‐N21, bound to Group I peptides, while N21 did not. Here, we identified single‐point mutations that enable N21 to bind a Group I peptide ligand through structure and dynamic‐based computational design. Comparison of the docked position of the CC16‐N21/ligand complex with the N21 structure showed that residues at positions 9 and 19 are important for peptide binding, whereas the dynamic profiles identified position 10 as allosterically coupled to the binding site and exhibiting different dynamics between N21 and CC16‐N21. We found that swapping these positions in N21 with matched residues from CC16‐N21 recovers nature‐like binding affinity to N21. This study validates the use of dynamic profiles as guiding principles for affecting the binding affinity of small proteins.
Prediction of protein assemblies by structure sampling followed by interface‐focused scoring
Authors: Olechnovič Kliment , Valančauskas Lukas , Dapkūnas Justas , Venclovas Česlovas
Published: August 2023

Proteins often function as part of permanent or transient multimeric complexes, and understanding function of these assemblies requires knowledge of their three‐dimensional structures. While the ability of AlphaFold to predict structures of individual proteins with unprecedented accuracy has revolutionized structural biology, modeling structures of protein assemblies remains challenging. To address this challenge, we developed a protocol for predicting structures of protein complexes involving model sampling followed by scoring focused on the subunit‐subunit interaction interface. In this protocol, we diversified AlphaFold models by varying construction and pairing of multiple sequence alignments as well as increasing the number of recycles. In cases when AlphaFold failed to assemble a full protein complex or produced unreliable results, additional diverse models were constructed by docking of monomers or subcomplexes. All the models were then scored using a newly developed method, VoroIF‐jury, which relies only on structural information. Notably, VoroIF‐jury is independent of AlphaFold self‐assessment scores and therefore can be used to rank models originating from different structure prediction methods. We tested our protocol in CASP15 and obtained top results, significantly outperforming the standard AlphaFold‐Multimer pipeline. Analysis of our results showed that the accuracy of our assembly models was capped mainly by structure sampling rather than model scoring. This observation suggests that better sampling, especially for the antibody–antigen complexes, may lead to further improvement. Our protocol is expected to be useful for modeling and/or scoring protein assemblies.
Mixed 5f configuration in americium trichloride: Dynamical mean‐field theory combined with density functional theory study
Authors: Li Ru‐song , He Yu‐song , Wang Jin‐tao , Liu Zhi‐yong , Wang Yuan‐ming , Cao Ze‐lin , Xie Zheng
Published: August 2023

The electronic properties in particular the occupation number of 5f electrons and the valence state of Am ions in americium trichloride (AmCl3) are studied by using density functional theory (DFT) merged with dynamical mean‐field theory (DMFT). We find that j = 5/2, j = 7/2 manifolds both are in the insulating regimes, resulting in the semiconducting band gap of about 0.837 eV, together with the weak Am 5f‐conduction electrons hybridization and the localized 5f‐derived spectra feature in the vicinity of the Fermi level. The weighted summation for the occupation probabilities of 5fn (n = 3–7) atomic configurations suggests that 5f electrons have the inter‐configuration fluctuation with an average occupation number of 5f electrons n5f ~ 5.182, corresponding to the valence state of Am3.818+ in AmCl3. The 5fn‐mixing‐driven inter‐configuration fluctuation might originate from the complicated quantum mechanics processes such as the dual nature of 5f electrons and the flexible electronic configuration of Am ions. Finally, the so‐called quasiparticle band structure is also predicted.
Modeling of flexible metal wheel for pressurized lunar rover and traction performance prediction
Authors: Zhu Jianzhong , Shen Yan , Hao Pujun , Liu Jingna , Li Yuqiong , Wang Kang , Zou Meng
Published: August 2023

The pressurized lunar rover has become one of the most important equipment in lunar exploration and resource utilization missions. On the terrain of soft lunar regolith, the rover wheels are easy to slip, sink, or even fail to move. To improve the traction performance of the rover on soft lunar soil, it is necessary to study the interaction between the wheels and the lunar soil. The deformation of the flexible wheel provides a larger contact area, which results in greater tractive force. Moreover, flexible wheels have better comfort and stability than rigid wheels, which are needed for manned rovers. However, there are few studies on the wheel soil interaction model of the heavy flexible wheel for the pressurized lunar rover. In this paper, a metal flexible wheel soil interaction model for pressurized lunar rovers was established, and the traction performance of the flexible wheel was predicted by using this model. Then, the accuracy of the wheel soil interaction model was verified by the soil bin test. The experimental results showed that the average error between the theoretical value of sinkage and the experimental value was 13.9%, and the average error between the theoretical and experimental value of drawbar pull was 11.5%, indicating that the model has high prediction accuracy. The new model can be used to predict the traction performance of flexible wheels and the experimental results can provide a reference for the flexible wheel design lunar rovers.
Anisotropic Black Phosphorene Structural Modulation for Thermal Storage and Solar‐Thermal Conversion
Authors: Wang Yandong , Chen Yapeng , Dai Wen , Zhang Zhenbang , Kong Xiangdong , Li Maohua , Li Linhong , Gong Ping , Chen Huanyi , Ruan Xinxin , Jiao Chengcheng , Cai Tao , Zhou Wenying , Wang Zhongwei , Nishimura Kazuhito , Lin Cheng‐Te , Jiang Nan , Yu Jinhong
Published: August 2023

Exploiting novel strategies for simultaneously harvesting ubiquitous, renewable, and easily accessible solar energy based on the photothermal effect, and efficiently storing the acquired thermal energy plays a vital role in revolutionizing the current fossil fuel‐dominating energy structure. Developing black phosphorene‐based phase‐change composites with optimized photothermal conversion efficiencyand high latent heat is the most promising way to achieve efficient solar energy harvesting and rapid thermal energy storage. However, exfoliating high‐quality black phosphorene nanosheets  remains challenging, Furthermore, an efficient strategy that can construct the aligned black phosphorene frameworks to maximize thermal conductivity enhancement is still lacking. Herein, high‐quality black phosphorene nanosheets are prepared by an optimized exfoliating strategy. Meanwhile, by regulating the temperature gradient during freeze‐casting, the framework consisting of shipshape aligned black phosphorene at long‐range is successfully fabricated, improving the thermal conductivity of the poly(ethylene glycol) matrix up to 1.81 W m−1 K−1 at 20 vol% black phosphorene loading. The framework also endows the composite with excellent phase‐change material encapsulation capacity and  high latent heat of 103.91 J g−1. It is envisioned that the work advances the paradigm of contrasting frameworks with nanosheets toward controllable structure thermal enhancement of the composites.
Data Regulation in Africa: Free Flow of Data, Open Data Regimes and Cybersecurity
Authors: Hlomani Hanani , Ncube Caroline B.
Published: August 2023

This chapter seeks to address the concerns associated with data regulation on the African continent. In particular, the paper zooms in on three major aspects of data regulation that hold the reigns to the potential development of the continent. These are the free flow of data, the adoption of open data regimes and cybersecurity. This will be in the general context of Africa, with a focus on regulatory instruments from the different bodies at continental and sub-regional level as well as some national legislation from countries that have developed any legislative instruments that address the same concerns. Emphasis will also be paid to the strides that have been taken by the European Union, the first continental body that has taken a geographically concerted approach to comprehensive data regulation. The aim is to draw lessons from such efforts with the intention of determining an appropriate African centred approach to data regulation, particularly in the context of increased inter-African trade as envisaged by the Agreement on the African Free Continental Trade Area and an enhanced digital economy as motivated for in the Digital Transformation Strategy for Africa (2020–2030).
Preventable Losses: Threatening Rise in Suicides During the Pandemic
Authors: Mittal Komal , Philo Magdalene A. , Pathak Drishya
Published: August 2023

From being a public health emergency to becoming one of the worst humanitarian crises of the twenty-first century, the COVID-19 pandemic has unraveled the very fabric of human lifestyles, with mental health at the core of its concerns. Now more than ever, suicide has become a serious public health problem worldwide. Studies published after the pandemic was declared in March 2020 estimate that suicide rates will rise globally as a result of the COVID-19 pandemic. The WHO estimates that for each adult suicide, more than 20 others attempt suicide and suicide risk is much higher in individuals who previously attempted suicide. Hence, suicide prevention in the times of the COVID-19 pandemic has become a global priority not only due to the increased rate of mortality, but also because of exacerbation of risk factors including economic instability, poor access to healthcare facilities, basic amenities, social disconnect, and many more. The aim of this chapter is to examine the relationship between the COVID-19 pandemic and the rise in suicide rates and mental health concerns. The authors undertake an analysis of existing systems and programs put in place by the government and civil society groups to critically examine suicide prevention strategies and approaches and comment on the way forward.
Stigma Mechanisms in a Globalized Pandemic in India: A Theoretical Framework for Stigma
Authors: Chatterjee Anirban , Ramraj Balaji
Published: August 2023

Stigma has been documented to act as a significant barrier to healthcare access and healthcare-seeking behavior. Traditional frameworks of stigma and discrimination have been used in the past to explain the stigma associated with diseases such as tuberculosis, leprosy, and HIV. However, increasing globalization and unprecedented access to information via social media and the internet have altered infectious disease dynamics and have forced a rethink on mechanisms which propagate stigma. SARS, MERS, Ebola, and more recently COVID-19 have been associated with fear in communities across the globe due to the inherent uncertainties associated with emerging infectious diseases and a concurrent spread of misinformation—an infodemic. The authors present a theoretical framework to explain the evolution of COVID-19 associated stigma by exploring the complex interplay of various international and national mechanisms. It is anticipated that a conceptual framework which explains the evolution of stigma in fast-spreading global pandemics such as COVID-19 may also prove to be useful as a starting point for furthering the discussion on the progenitors, pathways, and manifestations of COVID-19-related stigma. This should be of practical use to researchers who are interested in exploring, validating, and identifying interventions for informing other frameworks for similar diseases.
COVID-19 in Mexico: How the Systems Approach Can Improve Our Response
Authors: Orozco Oscar San Roman , Bloch Kiera , Torino Robert
Published: August 2023

Using Mexico as a model nation, the authors explore the systems approach for addressing COVID-19. The elements in any system are highly interconnected as they continuously influence each other. Public health challenges do not exist in a vacuum but are influenced by several factors including the social, economic, and political context. To understand any one factor, mapping the surrounding elements and analyzing the relationship between them and other elements in the rest of the system is necessary. Key elements of the impact and the response to the pandemic are examined by applying the systems thinking approach within the Mexican context. A systems analysis of COVID-19 is conducted using a systems map to illustrate the complexity of the system and to understand how to leverage the power of systems thinking to execute intersectoral, innovative, and highly impactful interventions for an improved response to the ongoing COVID-19 pandemic and pandemics in the future.
Response to the COVID-19 Pandemic in Taiwan
Authors: Kukreti Shikha , Padmalatha Sriyani , Fu Shau-Huai , Chen Yu-Ching
Published: August 2023

In the midst of the COVID-19 pandemic, the world witnessed a large number of infections and deaths. Due to its proximity to China, it was initially feared that Taiwan would become the country worst affected by the pandemic. However, COVID-19 has been widely controlled in the region; a few local outbreaks occurred with limited cases since the pandemic began. Taiwan leveraged its experience in containing the SARS outbreak in 2003 to respond to the COVID-19 crisis with proactive measures, early deployment, prudent actions, and transparency. Most political debate in Taiwan has centered around vaccines. However, from challenges like vaccine availability to increasing the willingness to take vaccines by the population, the Taiwan government has succeeded well. Taiwan’s National Health Insurance system is a vital component of its strategy to improve the efficiency of healthcare delivery throughout the country. And the database integrated with the Centers of Disease Control provides real-time alerts to healthcare providers about patients whenever they are identified. In response to delta variant spread after a community outbreak, health monitoring measures were tightened, leading the country to successfully control the spread of the infection. Other countries can learn lessons from Taiwan's response to COVID-19.
COVID-19: An Accelerant Toward a Sustainable Health System in Kenya
Authors: Munene Daniella
Published: August 2023

In the face of supply chain inadequacies, human resource constraints, and pervasive false narratives that misinformed the public, the COVID-19 pandemic directed our individual and collective focus on the adequacy of our health system. Was it resilient enough? Had the deficiencies that we were seeing been there all along? Why were they not noticed? Why were voices not raised earlier about the gaps? Perhaps they were. But, why have the proposed changes not been made? Was it resource constraints? Was it poor policies? Was it weak enforcement? These were some of the questions that were going through our minds, the nature of the question reflecting the position each actor had within the system. Action was taken. People organized themselves into task forces and committees, and implemented strategies and work plans. And we started to see results. Face masks and assembling ventilators have now been manufactured in the country. Critical care capacity has been increased. Oxygen plants have been built. Policies have been drafted to spur the growth of the local pharmaceutical manufacturing sector. Drug supply chains have been diversified to prevent stock outs. The general public has tremendously increased its health literacy. Countries are in a much better place than when it began.
Prevalence and outcomes of end-stage kidney disease in patients with systemic lupus erythematous: a population-based study
Authors: Lao Chunhuan , Van Dantzig Philippa , White Douglas , Rabindranath Kannaiyan , Foxall Donna , Lawrenson Ross
Published: August 2023

This study aims to examine the prevalence and outcomes of end-stage kidney disease (ESKD) among systemic lupus erythematosus (SLE) patients. SLE patients identified from the national administrative datasets were linked to the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) to identify the ESKD cases. Period prevalence of ESKD among SLE patients was calculated. The risk of developing ESKD by ethnicity was explored with Cox Proportional Hazards model. The adjusted hazard ratio (HR) of all-cause mortality for Māori, Pacific, Asian compared to European/others was estimated. Of the 2837 SLE patients, 210 (7.4%) developed ESKD. The average period prevalence of ESKD among SLE patients was 5.7%. Men had twice the prevalence rate of ESKD than women (10.0% vs 5.2%). Māori and Pacific had higher prevalence rate than Asian and European/others (9.4%, 9.8% vs 4.4% and 3.8%). The adjusted HR of developing ESKD for men compared to women was 3.37 (95% CI 1.62–7.02). The adjusted HR of developing ESKD for Māori and Pacific compared to European/others was 4.63 (95% CI 1.61–13.29) and 4.66 (95% CI 1.67–13.00), respectively. Compared to European/others, Māori had an HR of 2.17 (95% CI 1.18–4.00) for all-cause mortality. SLE patients had a high prevalence rate of ESKD. Men, Māori, and Pacific patients with SLE were more likely to develop ESKD. Māori patients with ESKD had poorer survival than other patients. Interventions are needed to reduce the risk of ESKD and to improve the survival of ESKD patients for the disadvantaged groups.
Analysis of training pathway to reach expert performance levels based on proficiency-based progression in robotic-assisted minimally invasive esophagectomy (RAMIE)
Authors: Müller Dolores T. , Brunner Stefanie , Straatman Jennifer , Babic Benjamin , Eckhoff Jennifer A. , Reisewitz Alissa , Storms Christian , Schiffmann Lars M. , Schmidt Thomas , Schröder Wolfgang , Bruns Christiane J. , Fuchs Hans F.
Published: August 2023

Background

Robotic-assisted minimally invasive esophagectomy (RAMIE) was first introduced in 2003 and has since then shown to significantly improve the postoperative course. Previous studies have shown that a structured training pathway based on proficiency-based progression using individual skill levels as measures of reach of competence can enhance surgical performance. The aim of this study was to evaluate and help understand our pathway to reach surgical expert levels using a proficiency-based approach introducing RAMIE at our German high-volume center.

Methods

All patients undergoing RAMIE performed by two experienced surgeons for esophageal cancer since the introduction of the robotic technique in 2017 was included in this analysis. Intraoperative outcomes and postoperative outcomes were included in the analysis. The cumulative sum method was used to analyze how many cases are needed to reach expert levels for different performance characteristics and skill sets during robotic-assisted minimally invasive esophagectomy.

Results

From 06/2017 to 03/2022, a total of 154 patients underwent RAMIE at our facility and were included in the analysis. An advancement in performance level was observed for total operating time after 70 cases and for thoracic operative time after 79 cases. Lymph node yield showed an increase up until case 60 in the CUSUM analysis. Length of hospital stay stabilized after case 55. The CCI score inflection point was at case 55 in both CUSUM and regression analyses. Anastomotic leak rate stabilized at case 38 and showed another inflection point after case 83.

Conclusion

Our data and analysis showed the progression from proficient to expert performance levels during the implementation of RAMIE at a European high-volume center. Further analysis of surgeons, especially with a different training status has yet to reveal if the caseloads found in this study are universally applicable. However, skill acquisition and respective measures of such are diverse and as a great range of number of cases was observed, we believe that the learning curve and ascent in performance levels cannot be defined by one parameter alone.
Limb position affects intraoperative assessment of condylar width
Authors: Tucker Douglass W. , Chen Michael J. , Reddy Akhil , Carney John J. , Gardner Michael J. , Marecek Geoffrey S.
Published: August 2023

Purpose

We sought to define how changes in position and rotation of fluoroscopic imaging may affect the assessment of condylar widening intraoperatively.

Methods

Thirty-three patients with tibial plateau fractures were prospectively identified and included in this study. Fluoroscopic images of the uninjured tibial plateau were obtained in (1) full extension and (2) slight flexion on foam ramp. Beginning with a plateau view, additional views of the tibial plateau were then obtained by rotating the fluoroscope around the knee in 5 degree increments up to 15 degrees in both internal and external rotation. Measurements of distal femoral condylar width (DFW), distal femoral articular width (FAW), proximal tibial articular width (TAW) and lateral plateau width (LPW) were performed.

Results

LPW was decreased in flexion compared to extension at all degrees of rotation (p = 0.04–0.00001). There was a trend toward increasing LPW with increasing degrees of internal rotation which reached significance at 15˚ of internal rotation when the knee was flexed. On ANOVA, there was a significant difference of LPW with increasing degree of internal rotation when the knee was in flexion (p = 0.008), but not in extension. There were no differences in DFW, FAW, TAW and DFW/TAW at any point though LPW was decreased in flexion at all degrees of rotation. The FAW/TAW ratio was increased in flexion at all degrees of rotation.

Discussion

The knee in flexion will underestimate the measurement of condylar width compared to the knee in full extension, by ~ 2 mm. Rotation of the knee, in comparison, did not have a significant effect on condylar width assessment.

Level of evidence

Diagnostic II.
Diagnostic Value of MRI Features in Dual-phenotype Hepatocellular Carcinoma: A Preliminary Study
Authors: Gu Hong-Xian , Huang Xiao-Shan , Xu Jian-Xia , Zhu Ping , Xu Jian-Feng , Fan Shu-Feng
Published: August 2023

This study aimed to explore the magnetic resonance imaging (MRI) features of dual-phenotype hepatocellular carcinoma (DPHCC) and their diagnostic value.The data of 208 patients with primary liver cancer were retrospectively analysed between January 2016 and June 2021. Based on the pathological diagnostic criteria, 27 patients were classified into the DPHCC group, 113 patients into the noncholangiocyte-phenotype hepatocellular carcinoma (NCPHCC) group, and 68 patients with intrahepatic cholangiocarcinoma (ICC) were classified into the ICC group. Two abdominal radiologists reviewed the preoperative MRI features by a double-blind method. The MRI features and key laboratory and clinical indicators were compared between the groups. The potentially valuable MRI features and key laboratory and clinical characteristics for predicting DPHCC were identified by univariate and multivariate analyses, and the odds ratios (ORs) were recorded. In multivariate analysis, tumour without capsule (P = 0.046, OR = 9.777), dynamic persistent enhancement (P = 0.006, OR = 46.941), and targetoid appearance on diffusion-weighted imaging (DWI) (P = 0.021, OR = 30.566) were independently significant factors in the detection of DPHCC compared to NCPHCC. Serum alpha-fetoprotein (AFP) > 20 µg/L (P = 0.036, OR = 67.097) and prevalence of hepatitis B virus (HBV) infection (P = 0.020, OR = 153.633) were independent significant factors in predicting DPHCC compared to ICC. The differences in other tumour marker levels and imaging features between the groups were not significant. In MR enhanced and diffusion imaging, tumour without capsule, persistent enhancement and DWI targetoid findings, combined with AFP > 20 µg/L and HBV infection-positive laboratory results, can help to diagnose DPHCC and differentiate it from NCPHCC and ICC. These results suggest that clinical, laboratory and MRI features should be integrated to construct an AI diagnostic model for DPHCC.
US Population Eligibility and Estimated Impact of Semaglutide Treatment on Obesity Prevalence and Cardiovascular Disease Events
Authors: Wong Nathan D. , Karthikeyan Hridhay , Fan Wenjun
Published: August 2023

Background

Semaglutide 2.4 mg benefits weight loss and reduction of cardiovascular disease (CVD) risk factors in adults with obesity. We estimated the US population eligibility for semaglutide 2.4 mg (based on the weight management indication) and the impact on obesity and CVD events.

Methods

We applied STEP 1 trial eligibility criteria to US adults aged ≥ 18 years in the US National Health and Nutrition Examination Survey (NHANES) 2015-2018 to estimate the US eligible population. Semaglutide weight changes in STEP 1 were applied to estimate the population impact on weight changes and obesity prevalence. We also estimated 10-year CVD risks utilizing the BMI-based Framingham CVD risk scores. The difference in estimated risks with and without semaglutide “treatment” multiplied by the eligible NHANES weighted population represented the estimated “preventable” CVD events.

Results

We identified 3999 US adults weighted to an estimated population size of 93.0 million [M] (38% of US adults) who fit STEP 1 eligibility criteria. Applying STEP 1 treatment effects on weight loss resulted in an estimated 69.1% (64.3 M) and 50.5% (47.0 M) showing ≥ 10% and ≥ 15% weight reductions, respectively, translating to a 46.1% (43.0 M) reduction in obesity (BMI ≥ 30 kg/m2) prevalence. Among those without CVD, estimated 10-year CVD risks were 10.15% “before” and 8.34% “after” semaglutide “treatment” reflecting a 1.81% absolute (and 17.8% relative) risk reduction translating to 1.50 million preventable CVD events over 10 years.

Conclusion

Semaglutide treatment in eligible US adults may substantially reduce obesity prevalence and CVD events, which may dramatically impact associated healthcare costs.
ProCrackPlast: a finite element tool to simulate 3D fatigue crack growth under large plastic deformations
Authors: Ganesh Rahul , Dude Durga Prasanth , Kuna Meinhard , Kiefer Bjoern
Published: August 2023

Many structural components and devices in combustion and automotive engineering undergo highly intensive cyclic thermal and mechanical loading during their operation, which leads to low cycle (LCF) or thermomechanical (TMF) fatigue crack growth. This behavior is often characterized by large scale plastic deformations and creep around the crack, so that concepts of linear-elastic fracture mechanics fail. The finite element softwareProCrackPlast has been developed at TU Bergakademie Freiberg for the automated simulation of fatigue crack growth in arbitrarily loaded three-dimensional components with large scale plastic deformations, in particular under cyclic thermomechanical loading.ProCrackPlast consists of a bundle of Python routines, which manage finite element pre-processing, crack analysis, and post-processing in combination with the commercial softwareAbaqus .ProCrackPlast is based on a crack growth procedure which adaptively updates the crack size in finite increments. Crack growth is controlled by the cyclic crack tip opening displacement$$\varDelta $$ΔCTOD, which is considered as the appropriate fracture-mechanical parameter in case of large scale yielding. The three-dimensional$$\varDelta $$ΔCTOD concept and its effective numerical calculation by means of special crack-tip elements are introduced at first. Next, the program structure, the underlying numerical algorithms and calculation schemes ofProCrackPlast are outlined in detail, which capture the plastic deformation history along with the moving crack. In all simulations, a viscoplastic cyclic material law is used within a large strain setting. The numerical performance of this software is studied for a single edge notch tension (SENT) specimen under isothermal cyclic loading and compared to common finite element techniques for fatigue crack simulation. The capability of this software is featured in two application examples showing crack growth under mixed-mode LCF and TMF in a typical austenite cast steel, Ni-Resist. In combination with a crack growth law identified in terms of$$\varDelta $$ΔCTOD for a specific material, the toolProCrackPlast is able to predict the crack evolution in a 3D component for a given thermomechanical loading scenario.
Does Dyadic Gratitude Make Sense? The Lived Experience and Conceptual Delineation of Gratitude in Absence of a Benefactor
Authors: Hebbink Nick , Schinkel Anders , de Ruyter Doret
Published: August 2023

In this paper we defend the idea that dyadic gratitude — i.e. gratitude in absence of a benefactor — is a coherent concept. Some authors claim that ‘gratitude’ is by definition a triadic concept involving a beneficiary who is grateful for a benefit to a benefactor. These authors state that people who use the term gratitude in absence of a benefactor do so inappropriately, e.g. by using it as an interchangeable term for ‘appreciation’ or ‘being glad’. We believe that the conceptual analyses which underlie such statements are too strongly focused on language and pay insufficient attention to the lived experience of gratitude. Thus, we have conducted a phenomenological analysis of several experiences in which people report feeling gratitude in absence of a benefactor. Informed by our phenomenological findings, we argue that dyadic gratitude is a coherent concept that shares certain core experiential elements with triadic gratitude. Gratitude is an appreciative response that construes its object as a gratuitous good and as a (metaphorical) gift; it is characterised by a receptive-appreciative attitude, an awareness that we are in some sense dependent on something other than ourselves, and a motivational impetus to promote, celebrate and/or radiate goodness. Finally, we argue that dyadic gratitude is a useful concept because it enables us to think and communicate effectively about a set of experiences. Moreover, it is also a scientifically and philosophically relevant concept, since it seems to be associated with various positive psychosocial effects and might even be developed as a virtuous disposition.
Quantifying the Structural Stability of Simplicial Homology
Authors: Guglielmi Nicola , Savostianov Anton , Tudisco Francesco
Published: August 2023

Simplicial complexes are generalizations of classical graphs. Their homology groups are widely used to characterize the structure and the topology of data in e.g. chemistry, neuroscience, and transportation networks. In this work we assume we are given a simplicial complex and that we can act on its underlying graph, formed by the set of 1-simplices, and we investigate the stability of its homology with respect to perturbations of the edges in such graph. Precisely, exploiting the isomorphism between the homology groups and the higher-order Laplacian operators, we propose a numerical method to compute the smallest graph perturbation sufficient to change the dimension of the simplex’s Hodge homology. Our approach is based on a matrix nearness problem formulated as a matrix differential equation, which requires an appropriate weighting and normalizing procedure for the boundary operators acting on the Hodge algebra’s homology groups. We develop a bilevel optimization procedure suitable for the formulated matrix nearness problem and illustrate the method’s performance on a variety of synthetic quasi-triangulation datasets and real-world transportation networks.
Suchthilfe und -prävention für Menschen mit geistiger Behinderung: Ergebnisse einer bundesweiten Online-Befragung von Fachkräften des Suchthilfesystems
Authors: Schote Caroline , Rathmann Katharina
Published: August 2023

Hintergrund

Durch die fortschreitende Inklusion und die Möglichkeiten stärkerer Teilhabe von Menschen mit (geistiger) Behinderung kommt dieser Personenkreis zunehmend auch in Kontakt mit Suchtmitteln. Dabei ist das Risiko, eine Abhängigkeit bzw. Sucht zu entwickeln, ähnlich hoch wie bei Menschen ohne Behinderung, allerdings bestehen noch immer Ungleichheiten im Zugang zu geeigneten Angeboten der Suchthilfe und -prävention. Ziel des Beitrags ist daher 1) den Kenntnisstand sowie das Angebot zielgruppenspezifischer Programme und Maßnahmen der Suchthilfe und -prävention zu erfassen, 2) die Vernetzung zwischen Sucht- und Behindertenhilfe zu erfassen, 3) den Zusammenhang zwischen der Vernetzung und den zielgruppenspezifischen Angeboten der Suchthilfe und -prävention zu analysieren und 4) den Unterstützungsbedarf von Fachkräften des Suchthilfesystems zu ermitteln, um die Teilhabechancen von Menschen mit geistiger Behinderung an den Suchthilfestrukturen zukünftig zu verbessern.

Material und Methoden

Datenbasis stellt eine Primärerhebung (online) bei Fachkräften des Suchthilfesystems in Deutschland dar. Der Feldzugang erfolgte per E‑Mail über insgesamt 1677 Einrichtungen. An der Befragung nahmen n = 533 Fachkräfte teil. Die Daten wurden mittels uni- und bivariater Analysen ausgewertet.

Ergebnisse

Insgesamt gaben 62 % der befragten Fachkräfte an, keine suchtspezifischen Angebote für Menschen mit geistiger Behinderung zu kennen, 87 % bieten keine Angebote für diese Zielgruppe an. Gut die Hälfte der Befragten (52 %) arbeitet mit Einrichtungen der Behindertenhilfe zusammen. Die bivariaten Auswertungen verdeutlichen, dass mit der Behindertenhilfe vernetzte Einrichtungen häufiger suchtspezifische Angebote für Menschen mit geistiger Behinderung bereitstellen als nicht vernetzte Einrichtungen. Großer bis sehr großer Unterstützungsbedarf für Fachkräfte des Suchthilfesystems besteht in Bezug auf Weiterbildungsangebote, Handlungsempfehlungen, Leitfäden und Arbeitshilfen, um eine zielgruppenadäquate Beratung, Behandlung und Prävention anbieten zu können.

Schlussfolgerung

Um den Zugang für Menschen mit geistiger Behinderung zu Angeboten der Suchthilfe und -prävention zu verbessern, sollten entsprechende Angebote (weiter-)entwickelt werden und in der Suchthilfe Anwendung finden. Wichtige Voraussetzungen hierfür sind die stärkere Vernetzung zwischen Sucht- und Behindertenhilfe, eine wirksame Öffentlichkeitsarbeit sowie Qualifizierungsangebote und Informationen.
Maintaining long-term physical activity after cancer: a conceptual framework to inform intervention development
Authors: Grimmett Chloe , Corbett Teresa , Bradbury Katherine , Morton Kate , May Carl R. , Pinto Bernardine M. , Foster Claire
Published: August 2023

Purpose

This paper describes a conceptual framework of maintenance of physical activity (PA) and its application to future intervention design.

Methods

Evidence from systematic literature reviews and in-depth (N = 27) qualitative interviews with individuals with cancer were used to develop a conceptual framework of long-term physical activity behaviour. Determinants of long-term PA were listed and linked with domains of the Theoretical Domains Framework which in turn were linked to associated behaviour change techniques (BCTs) and finally to proposed mechanisms of action (MoA).

Results

The conceptual framework is presented within the context of non-modifiable contextual factors (such as demographic and material resources) and in the presence of learnt and adapted behavioural determinants of skills, competence and autonomous motivation that must be established as part of the initiation of physical activity behaviour. An inventory of 8 determinants of engagement in long-term PA after cancer was developed. Clusters of BCTs are presented along with proposed MoA which can be tested using mediation analysis in future trials.

Conclusion

Understanding the processes of PA maintenance after cancer and presentation of implementable and testable intervention components and mechanisms of action to promote continued PA can inform future intervention development.

Implications for Cancer Survivors

This resource can act as a starting point for selection of intervention components for those developing future interventions. This will facilitate effective support of individuals affected by cancer to maintain PA for the long term.