bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinicopathological characteristics of fibrosing alopecia in a pattern distribution: a single‐center, retrospective study
Authors: Wei Kelu , Ni Chunya , Huang Qiong , Yang Kai , Zhang Yue , Liu Qingmei , Sha Yuou , Zhang Qiaoan , Lin Jinran , Wu Wenyu
Published: September 2023

Background

Fibrosing alopecia in a pattern distribution (FAPD) is a distinct entity of primary cicatricial alopecia (PCA), mimicking diffuse hair loss of androgenetic alopecia (AGA) with trichoscopic and histopathologic features of both AGA and lichen planopilaris (LPP).

Methods

Clinical, demographic, and histopathological data of 20 FAPD patients were retrospectively collected.

Results

All patients presented with female pattern hair loss with a median Sinclair grade of 3. Trichoscopic findings revealed hair diameter variability (20/20), perifollicular erythema (mild 7/20, moderate 11/20, severe 2/20), peripilar casts (none 2/20, mild 12/20, moderate 5/20, severe 1/20), and loss of follicular ostia (+12/20, ±7/20, −1/20). Histopathologic examination revealed perifollicular lymphocytic infiltration at the infundibulum or isthmus level and an increase of vellus‐like hairs. All cases showed interface dermatitis with concentric perifollicular lamellar fibrosis and follicular scars. Infundibular or isthmic infiltration of mast cells was found.

Conclusions

The uniqueness of our study lies in perifollicular mast cells and discovering that the young population is at higher risk than previously thought. Clinicopathological features of FAPD were identified, filling the void of much‐needed details for FAPD diagnosis tailored to the Chinese population.
Do supplementary jobs for welfare recipients increase the chance of welfare exit? Evidence from Germany
Authors: Mosthaf Alexander , Schank Thorsten , Schwarz Stefan
Published: September 2023

Welfare recipients in Germany are allowed to take up supplementary jobs while receiving welfare. In the present study, we use the German Panel Study “Labour Market and Social Security” (PASS) for the years 2006–2014 to analyze the impact of these supplementary jobs on the chances of welfare exit. Dynamic multinomial logit models controlling for unobserved heterogeneity and endogenous initial conditions reveal that full‐time employed men and women are more likely to exit welfare into employment than their non‐employed counterparts. For supplementary part‐time jobs, however, we find no or (only in some specifications for men) much smaller stepping stone effects.
Study of platelet‐rich fibrin combined with rat periodontal ligament stem cells in periodontal tissue regeneration
Authors: Duan Xuejing , Lin Zhiyong , Lin Xiujuan , Wang Zhiqiang , Wu Yihua , Ji Mei , Lu Wei , Wang Xiaoyang , Zhang Dongsheng
Published: September 2023

The objective of this study was to investigate the advantages and feasibility of periodontal tissue regeneration using platelet‐rich fibrin (PRF) combined with rat periodontal ligament stem cells (PDLSCs) for the first time. We first determined the effect of PRF on rat PDLSCs in vitro. We next conducted an in vivo study, in which a tissue engineering technique was performed to repair periodontal defects in five groups: a blank group, collagen group (implanted collagen membrane), collagen + cells group (implanted collagen membrane and rat PDLSCs), PRF group (implanted PRF membrane) and PRF + cells group (implanted PRF membrane and rat PDLSCs). PRF greatly enhanced cell proliferation, mRNA and protein expression levels of bone sialoprotein (BSP), osteocalcin (OC), and runt‐related transcription factor 2 (RUNX2) and activity of alkaline phosphatase (ALP) in vitro. Transplantation of PRF combined with rat PDLSCs resulted in higher expression of osteopontin (Opn), collagen I (COL1A) and RUNX2 at both 12 and 24 days after surgery. Micro‐computed tomography and histological analysis showed substantially more new bone formation in the PRF + cells group at 24 days after surgery. Based on these results, we discuss the role of PRF in the proliferation and differentiation of rat PDLSCs and suggest that PRF combined with rat PDLSCs provides a valuable tool for periodontal tissue engineering.
The role of reflectance confocal microscopy in the diagnosis and management of pigmentary disorders: A review
Authors: Farabi Banu , Khan Samavia , Jamgochian Marielle , Atak Mehmet Fatih , Jain Manu , Rao Babar K.
Published: September 2023

Background

Reflectance confocal microscopy (RCM) has quickly transitioned from a research tool to an adjunct diagnostic bedside tool, providing the opportunity for noninvasive evaluation of skin lesions with histologic resolution. RCM is an optical imaging technique that uses near‐infrared excitation wavelengths and safe low‐power lasers. En‐face images of different skin layers (up to the superficial dermis) are acquired in grayscale based on the reflective indices of tissue components. Melanin has the highest reflective index (contrast) and appears bright on RCM.

Aims

We present a review of the current literature on the use of RCM in the diagnosis and management of pigmentary disorders.

Methods

We reviewed PubMed and Ovid Medline databases from January 2000 to June 2021, using MeSH key terms: “reflectance confocal microscopy, confocal laser scanning microscopy, pigmentary disorders, treatment, melasma, vitiligo, freckles, solar lentigo, lentigo, tattoo, complications, melanoma, skin cancers, pigmented lesions, post inflammatory, melanin, photoaging” to identify studies and review articles discussing the use of RCM in the diagnosis and management of pigmentary disorders.

Results

RCM findings of pigmentary disorders were divided into the following categories: (1) disorders of increased pigmentation (post‐inflammatory hyperpigmentation, melasma, Riehl's melanosis, solar lentigines, ephelides, hori nevus, naevus of Ota, café‐au‐lait macules, melanocytic nevus, melanoma, nevus spilus, labial mucosal melanosis, and mucosal melanoma), (2) disorders of decreased pigmentation or depigmentation (post‐inflammatory hypopigmentation, vitiligo, nevus depigmentosus, halo nevus), and (3) exogenous pigmentation (tattoo, ochronosis).

Conclusion

RCM has been explored and proven valuable for the evaluation and management of pigmentary disorders including melasma, vitiligo, solar lentigines, tattoo, and tattoo‐related complications.
Recreational cannabis policy reform—What mental health nurses need to know about minimising harm and contributing to the reform debate
Authors: Murta Janina Catalao Dionisio , Easpaig Brona Nic Giolla , Hazell‐Raine Karen , Byrne Mitchell K. , Lertwatthanawilat Wanchai , Kritkitrat Preeyakamon , Bressington Daniel
Published: September 2023

The recently rapidly evolving legal status of recreational cannabis in various countries has triggered international debate, particularly around measures required to minimise resulting harms. The present article argues that mental health nurses should have a key role in promoting safe and appropriate use of recreational cannabis, and minimising harm based on the extant evidence. The article summarises the factors driving legalisation, outlines the evident medicinal benefits of cannabis, and appraises the evidence on the negative mental health impacts associated with use. We go on to discuss research findings on the potentially deleterious mental health effects resulting from legalising recreational cannabis and strategies to minimise these harms, including directions for future research and evaluation. Further, we consider the importance of the implementation of harm minimisation measures that are context‐specific, using Thailand as an example. Finally, we present the key health promotion messages that mental health nurses should aim to convey to people who use or consider using recreational cannabis. Ultimately, we aim to provide a summary of the existing evidence that mental health nurses can draw upon to promote mental health and engage with the policy reform debate.
Extracellular vesicles biogenesis and uptake concepts: A comprehensive guide to studying host–pathogen communication
Authors: Sabatke Bruna , Rossi Izadora Volpato , Sana Abel , Bonato Leticia Bassani , Ramirez Marcel I.
Published: September 2023

The study of host–pathogen interactions has increased considerably in recent decades. This intercellular communication has been mediated by extracellular vesicles (EVs) that play an important role during the interaction. EVs are particles of lipid bilayer and described in different types of cells, eukaryotic or prokaryotic. Depending on their biogenesis they are described as exosomes (derived from multivesicular bodies) and microvesicles (derived from the plasma membrane). The EVs carry biomolecules, including nucleic acids, lipids, and proteins that can be released or internalized by other cells in different pathways (endocytosis, macropinocytosis, phagocytosis, or membrane fusion) in the process described as uptake. The balance between biogenesis and uptake of EVs could modify physiological and pathophysiological processes of the cell. This review is focusing on the dynamic roles of release and capture of EVs during host–pathogen interaction. We also do a critical analysis of methodologies for obtaining and analyzing EVs. Finally, we draw attention to critical points to be considered in EV biogenesis and uptake studies.
Food and non‐alcoholic beverage marketing in children and adults: A systematic review and activation likelihood estimation meta‐analysis of functional magnetic resonance imaging studies
Authors: Boyland Emma , Maden Michelle , Coates Anna E. , Masterson Travis D. , Alblas Monique C. , Bruce Amanda S. , Roberts Carl A.
Published: September 2023

Food marketing impacts the food behaviors of children and adults, but the underpinning neural mechanisms are poorly understood. This systematic review and meta‐analysis pooled evidence from neuroimaging studies of exposure to food marketing stimuli (vs. control) on brain activations in children and adults to clarify regions associated with responding. Databases were searched for articles published to March 2022. Inclusion criteria included human functional magnetic resonance imaging (fMRI) studies employing a contrast between a food marketing stimulus and a non‐food/non‐exposure control, published in English in a peer‐reviewed journal, reporting whole brain (not Region of Interest [ROI] only) co‐ordinates. Eleven studies met inclusion criteria, of which eight were included in the quantitative synthesis (Activation Likelihood Estimation [ALE] meta‐analysis). Food marketing exposures (vs. controls) produced greater activation in two clusters lying across the middle occipital gyrus, lingual gyrus, and cuneus (cluster 1), and the postcentral gyrus, precentral gyrus, and the inferior parietal lobule/supramarginal gyrus (cluster 2). Brain responses to food marketing are most consistently observed in areas relating to visual processing, attention, sensorimotor activity, and emotional processing. Subgroup analyses (e.g., adults vs. children) were not possible because of the paucity of data, and sensitivity analyses highlighted some instability in the clusters; therefore, conclusions remain tentative pending further research.
Scoping review of outcome measures in cleft care used in research and reports
Authors: Sarilita Erli , Sjamsudin Endang , Mossey Peter A.
Published: September 2023

Treatment outcome measures are critical in the decision making of best practices in the OFC field. OFC consortium working groups provided standardization of outcome measures based on previous treatment outcome studies. However, the implementation of such standardization in OFC centres worldwide is unknown. This study presented mapped outcome measures in cleft care using a structured review method complemented by quantitative overview of the relevant published research to provide initial guidelines for the implementation of treatment outcome standardization. A scoping review of the literature of treatment outcomes in cleft care following Preferred Reporting Items for Systematic reviews and Meta‐Analyses extension for Scoping Reviews guidelines was performed. The selected indexed paper in outcome measures mapped following the international consortium in standard set of outcome measures in cleft care. Three hundred and sixty‐five articles were filtered. The most discussed domains of cleft care were dental and oral health, appearance and speech/communication. Overall, the majority of publications were produced in high‐income countries. The current review indicates that there are inequalities of treatment outcome studies among the domain of cleft care. In addition, there are also inequalities of published articles from HIC versus LMIC in treatment outcomes. This information can be used to develop targeted interventions aimed at encouraging cleft centres worldwide to adapt standardized outcome measures.
Impact of the COVID‐19 pandemic on sleep bruxism among adolescents in Brazil: A longitudinal study
Authors: Lito Marcia Farias Pereira , Knorst Jessica Klöckner , Noronha Thaís Gioda , Pohl Marina Blanco , Brondani Bruna , de Araújo Gabriela , Ardenghi Thiago Machado , Tomazoni Fernanda
Published: September 2023

Aim

To evaluate the immediate and late impact of the COVID‐19 pandemic on the occurrence of possible sleep bruxism (SB) among adolescents in Brazil.

Design

This is a longitudinal study performed with adolescents (11–15 years old) from Southern Brazil. Baseline data were collected before the Brazilian COVID‐19 outbreak (T1). Posteriorly, data were collected after 3 (T2) and 15 months under the Brazilian COVID‐19 outbreak. The possible SB was evaluated by the question: ‘Do you grind your teeth during your sleep?’. Sociodemographic, psychosocial and clinical variables were also collected. Changes in SB were evaluated by multilevel logistic regression models for repeated measures.

Results

Of the 290 adolescents assessed at T1, 182 were reassessed at both follow‐ups. The prevalence of possible SB was 13% at T1, 11% at T2 and 22% at T3. There were no immediate effects of the COVID‐19 pandemic on the occurrence of possible SB (T2). Adolescents had odds 2.77 times greater of presented possible SB after 15 months (T3) of COVID‐19 pandemic scenarios when compared to T1.

Conclusion

There was a considerable and late increase in the possible SB in adolescents in Brazil during the COVID‐19 pandemic.
Gender inequality among the editorial boards of periodontology and implantology journals
Authors: Pekin Sevgi , Buduneli Nurcan , Ellidokuz Hülya , Akcalı Aliye
Published: September 2023

Objectives

The aim of the present study was to investigate gender composition of the editorial board members of the journals in the field of periodontology and implantology.

Materials and Methods

A rigorous search was performed through Web of Science database to identify journals, scoping on the periodontology and implantology research fields. Data on journal's demographic information, gender of the editorial board members were gathered from the journals fulfilling the predefined inclusion/exclusion criteria. Variables including journal impact factor and quartiles were extracted as well.

Results

The proportion of women in the editorial team in periodontology journals was 27.3%, whereas it was almost 19% in implantology journals. As for editorial leadership, these ratios were 22.1% and 19.8%, respectively. There were significantly less women than men in editor‐in‐chief position in periodontology journals (p = 0.042). Journal metrics had no impact on the gender distribution of editor‐in‐chief positions in both fields.

Conclusions

Women seem to be under‐represented as editorial leaders or board members in journals of periodontology and implantology. The proportion of women in periodontology journals has increased in the last decade; however, there is still a clear need for further increase to have a gender balance.
One Step Double Augmentation with Human Dermis Allograft and Homologous PRP in Misdiagnosed and or Chronic Achilles Tendon Ruptures
Authors: Lughi Marcello , Bondioli Elena , Moretti Cinzia , Maitan Nicolò , Ferretti Matteo , Casadei Roberto
Published: September 2023

Objective

Misdiagnosed/chronic Achilles tendon injuries are rare and disabling for patients. The surgical treatment of these rare injuries aims to ensure the tendon heals mechanically and biologically. This is the prerequisite for a good clinical and functional outcome and reduces recurrences. The main aim of the study is to present a surgical technique that has proven to be original, reproducible, and capable of guaranteeing solid tendon repair and optimal tissue regeneration.

Methods

We treated five patients, four males and one female, with the one‐step double augmentation technique. All patients of this study complained of pain, but above all severe functional limitation that Achilles tendon injury had been causing for more than a month. In this study, we widely described the surgical technique, original and not found in the literature, which provides a biological graft (allograft of decellularized dermis) and homologous, thrombin‐activated, platelet‐rich plasma (H‐PRP) in a single step. Surgical approach, always used by the first author, respected predefined steps: careful dissection and preparation of the peritendinous tissues from suture to the end of the procedure, tenorrhaphy, and augmentation with allopatch to obtain a mechanically effective repair to avoid recurrences, and finally “biological” augmentation with a unit of homologous, thrombin activated, PRP. We offered to all patients a regenerative rehabilitation program post‐operatively.

Results

All patients were evaluated clinically (functional clinical tests and questionnaires) and instrumentally (elastic‐sonography and perfusion MRI). The obtained results have been evaluated at a minimum follow‐up of 18 months and a maximum of 24 months. In all patients pain was resolved, and district function and kinetic chains improved with resumption of daily activities, work, and sports.

Conclusion

The present study confirmed the regenerative potential of decellularized dermis allograft and PRP (homologous and thrombin‐activated). The same approach can also be exploited in cases of severe tendon destructuring and limited “intrinsic” regenerative potential at any age. The proposed one‐step surgical technique of a double augmentation therefore appears useful, safe, reproducible, and applicable in all chronic tendon lesions with low regenerative potential.
Is Sliding Compression Necessary for Intramedullary Nailing Fixation of AO/OTA Type A3.3 Intertrochanteric Fracture?
Authors: Zhang Cong , Chen Zhangxin , Wang Mengyuan , Chen Huiyu , Zhu Lingqi , Yang Wenqing , Ding Zhenqi , Huang Guofeng
Published: September 2023

Objectives

The intramedullary nail is considered the gold standard for treating AO/OTA type A3.3 intertrochanteric fractures. However, it still faces a significant rate of failure, mainly due to the critical factor of comminuted lateral wall defects leading to inadequate proximal sliding compression. The primary objective of this study is to investigate the requirement of sliding compression in the treatment of unstable AO/OTA type A3.3 intertrochanteric fractures. To achieve this, we conduct a comparative analysis between two approaches: InterTAN alone and proximal femoral anti‐rotation blade nailing (PFNA) combined with lateral wall reconstruction for treating AO/OTA type A3.3 intertrochanteric fractures with lateral wall damage.

Methods

A retrospective analysis was conducted on the clinical data of patients who underwent intramedullary nailing fixation for AO/OTA type A3.3 intertrochanteric fractures at our hospital from January 2012 to January 2022. Patient characteristics as well as treatment details, including operative time, intraoperative blood loss, weight‐bearing time, fracture healing time, tip apex distance (TAD) loss, Harris hip scores (HHS), Parker–Palmer mobility score (PPMS), and postoperative complications, were collected and analyzed. Continuous variables were analyzed using independent sample t‐tests, while categorical variables were examined using the chi‐square test. For group comparisons, variance analysis was applied, and pairwise comparisons were conducted using the LSD‐t test.

Results

These patients were divided into PFNA combined with lateral wall reconstruction group (sliding compression group) and InterTAN fixation group (static fixation group) based on surgical methods. The operation time, intraoperative bleeding loss, HHS at 12 months and PPMS at 12 months in the sliding compression group were significantly higher than those in the static fixation group, and time to weight‐bearing and fracture healing time were significantly lower than those in the static fixation group (p < 0.05). There were no significant differences between two groups in terms of the TAD at 2 days, 2, and 12 months postoperatively, the incidence of complications (p > 0.05). At 6 months postoperatively, femoral neck length was shortened compared to 2 days postoperatively in both groups, and the sliding compression group had a significantly greater degree of femoral neck shortening than the static fixation group (p < 0.05).

Conclusion

The use of PFNA with lateral wall reconstruction for A3.3 intertrochanteric fractures demonstrated superior mobility, efficiency, and reduced internal fixation failure rates compared to InterTAN. These findings suggest that sliding compression may be required for intramedullary nailing treatment.
Brief history of the Society for Melanoma Research: A community of clinicians, researchers, and friends
Authors: Rebecca Vito W. , Villanueva Jessie , Webster Marie R.
Published: September 2023

To commemorate the 20th Anniversary of the Society of Melanoma Research and the first International Melanoma Research Congress held in June of 2003, we have described in brief, how the Society for Melanoma Research (SMR) began, the purpose, goals, and governance of the SMR, and how the society has evolved to support new melanoma researchers. In celebration of the immense progress in treating melanoma patients over the last 20 years and the impact of the SMR on these advances, we have highlighted memories and insight from early SMR members and founders.
Extraction of visual information to predict crowdfunding success
Authors: Blanchard Simon J. , Noseworthy Theodore J. , Pancer Ethan , Poole Maxwell
Published: September 2023

Researchers have increasingly turned to crowdfunding platforms to gain insights into entrepreneurial activity and dynamics. While previous studies have explored various factors influencing crowdfunding success, such as technology, communication, and marketing strategies, the role of visual elements that can be automatically extracted from images has received less attention. This is surprising, considering that crowdfunding platforms emphasize the importance of attention‐grabbing and high‐resolution images, and previous research has shown that image characteristics can significantly impact product evaluations. Indeed, a comprehensive review of empirical articles ( n = 202) utilized Kickstarter data, focusing on the incorporation of visual information in their analyses. Our findings reveal that only 29.70% controlled for the number of images, and less than 12% considered any image details. In this manuscript, we contribute to the existing literature by emphasizing the significance of visual characteristics as essential variables in empirical investigations of crowdfunding success. We review the literature on image processing and its relevance to the business domain, highlighting two types of visual variables: visual counts (number of pictures and number of videos) and image details. Building upon previous work that discussed the role of color, composition, and figure–ground relationships, we introduce visual scene elements that have not yet been explored in crowdfunding, including the number of faces, the number of concepts depicted, and the ease of identifying those concepts. To demonstrate the predictive value of visual counts and image details, we analyze Kickstarter data using flexible machine learning models (Lasso, Ridge, Bayesian additive regression trees, and eXtreme Gradient Boosting). Our results highlight that visual count features are two of the top three predictors of success and highlight the ease at which researchers can incorporate some information about visual information. Our results also show that simple image detail features such as color matter a lot, and our proposed measures of visual scene elements can also be useful. By supplementing our article with R and Python codes that help authors extract image details ( https://osf.io/ujnzp/ ), we hope to stimulate scholars in various disciplines to consider visual information data in their empirical research and enhance the impact of visual cues on crowdfunding success.
Identification and characterization of Entyloma eschscholziae, a recently introduced pathogen in Europe, and its segregate Entyloma dendromeconis sp. nov.
Authors: Piątek Marcin , Lutz Matthias , Kruse Julia , Stryjak‐Bogacka Monika
Published: September 2023

Entyloma includes pathogenic and saprobic species that infect or colonize dicotyledonous host plants. Although most Entyloma species are known only from native areas of occurrence, some species were introduced with their host plants and spread outside their natural areas. The identification of introduced species is important for detection and management of invasive species. In this study, the morphology, phylogeny and species boundaries of Entyloma eschscholziae, recently introduced from North America to Europe, are revisited. Morphology was similar among the type and other specimens of E. eschscholziae analysed on Eschscholzia californica. Both asexual and sexual morphs were observed. The rDNA ITS1‐5.8S‐ITS2 sequences of the E. eschscholziae specimens from Europe and New Zealand and the environmental sequence obtained from grassland soil in California, United States, were identical. Morphological and molecular analyses confirm that the causative agents of white smut on E. californica in native (North America) and introduced (Europe, New Zealand) areas belong to the same species. DNA barcodes obtained in this study (especially ITS sequence from the designated epitype specimen) could be used to facilitate its molecular identification. Specimens on Dendromecon rigida, previously assigned to E. eschscholziae, are morphologically distinct. An attempt to obtain DNA barcode data from degraded holotype material was not successful and no more recent material is available. However, based on the morphological differences and high host specificity found in Entyloma spp., it is appropriate to describe a new species, Entyloma dendromeconis, for this smut pathogen.
The racial economy of Instagram
Authors: O'Connor Sinéad
Published: September 2023

This paper explores the mechanisms of white supremacy within digital spaces in relation to the body/embodiment, social justice movements, and the nature and expression of contemporary feminism. New digital political economies work through social media such as Instagram to colonise, disempower and obscure the work of Black feminists in the sphere of fat liberation (re‐framed as ‘body positivity’), and in terms of imperatives for self‐care, which have been co‐opted by an emerging online wellness industry. I call to account the pervasiveness of neoliberal logics which are re‐shaping (post)feminism and re‐inscribing white supremacy onto bodies online and offline through ‘disciplined whiteness’.
Evaluating skin colour diversity in the validation of scar assessment tools
Authors: Garg Stuti P. , Williams Tokoya , Taritsa Iulianna C. , Wan Rou , Goel Chirag , Harris Raiven , Huffman Kristin , Galiano Robert D.
Published: September 2023

Across scar studies, there is a lack of dark‐skinned individuals, who have a predisposition for keloid formation, altered pigmentation and poorer quality of life (QOL). There is a need for patients of colour to be included in scar scale development and validation. In this study, we evaluate the racial diversity of patients included in the validation of scar assessment scales. A systematic review was conducted for articles reporting on the validation of a scar assessment tool. Racial, ethnic and Fitzpatrick skin type (FST) data were extracted. Fifteen scar scale validation studies were included. Nine of the studies did not mention FST, race or ethnicity of the patients. Two of the studies that reported FST or race information only included White patients or included no FST V/VI patients: mapping assessment of scars (MAPS) and University of North Carolina ‘4P’. Only four studies included non‐White patients or dark‐skinned patients in the validation of their scar scale: the modified Vancouver Scar Scale (VSS), modified Patient and Observer Scar Assessment Scale (POSAS), acne QOL and SCAR‐Q scales. The patients included in the modified VSS validation were 7% and 13% FST V/VI, 14% African in the modified POSAS and 4.5% FST V/VI in the SCAR‐Q. We highlight the severe lack of diversity in scar scale validation, with only 4 out of 15 studies including dark‐skinned patients. Given the susceptibility of darker‐skinned individuals to have poorer scarring outcomes, it is critical to include patients of colour in the very assessment tools that determine their scar prognosis. Inclusion of patients of colour in scar scale development will improve scar assessment and clinical decision‐making.
Una aproximación a los deberes de sacrificio en el derecho penal
Authors: Balmaceda Hoyos Gustavo , Muñoz Tejo Sebastián
Published: September 2023

Este artículo de investigación está centrado en el estudio del deber de sacrificio en el derecho penal, con el objetivo de analizar su relevancia en el marco legal contemporáneo y su implicación en la protección de los derechos legales de las personas. Así, por medio de un enfoque metodológico, que implica la revisión exhaustiva de principios jurídicos y teorías, el documento propone una reflexión sobre cómo se equilibran los deberes y derechos en situaciones de conflicto. Se examinan conceptos fundamentales como el de estado de necesidad, la teoría diferenciadora, el derecho a la legítima defensa y la relación entre libertad y solidaridad. La principal conclusión del estudio destaca la importancia del deber de sacrificio en el derecho penal y su interacción con los conceptos de libertad y solidaridad, subrayando la necesidad de considerar estos principios en la construcción de un sistema jurídico justo y equilibrado.
Cyclic Combustion Variability of Dimethyl-Ether-Fueled Agricultural Tractor Engine
Authors: Agarwal Avinash Kumar , Valera Hardikk , Kumar Vikram , Mukherjee Nalini Kanta , Mehra Shanti , Nene Devendra
Published: September 2023

Combustion in dimethyl-ether (DME)-fueled engines needs to be assessed carefully for its widespread acceptability from a drivability viewpoint. Since the test engine used in an off-highway segment, it was tested in a steady-state cycle for engine performance, combustion, emissions, and their cyclic variations, which were the only parameters to assess the drivability. This study investigated and analyzed the cyclic variations of a 100% DME-fueled engine equipped with modified mechanical fuel injection equipment. It was compared with baseline diesel to understand its positive and negative aspects. Experiments were conducted at different engine speeds (1200,1600, and 2000 rpm) and loads (No Load, 1.29, 2.59, 3.88, 5.18, and 6.47 bar brake mean effective pressure (BMEP)) . In-cylinder pressure was recorded for 250 consecutive engine cycles, and many combustion parameters were comparatively analyzed for diesel and DME fuelings. The coefficient of variation (COV) of maximum in-cylinder pressure (Pmax) was lower for DME than diesel at 1600 rpm and comparable at the other remaining engine speeds (1200 and 2000 rpm). Variations in COV of Pmax were higher at low loads and negligible at high loads for both test fuels. At 2000 rpm, the crank angle positions at which Pmax occurred were distributed in a narrow range for DME, representing higher combustion stability than baseline diesel. Variations in the maximum rate of pressure rise (RoPRmax) were lower for DME at 3.88 and 6.47 bar BMEP, while these were higher at 1.29 bar BMEP than baseline diesel. COV of indicated mean effective pressure (COVIMEP) decreased from lower to higher loads for diesel and DME fueling at 1600 and 2000 rpm engine speeds. The differences in COVIMEP between diesel and DME were negligible at higher loads, representing engine stability similar to baseline diesel. Combustion parameters assessed indicated that DME fueling led to lower cyclic variations than baseline diesel as the engine operated from lower to higher loads. At lower loads, DME fueling showed higher cyclic variations than baseline diesel.
Multi-Objective Conceptual Design of Turboexpander Subsystems: Inner Casings, a Case Study
Authors: Orlandi Rachele , Filice Valentina , Fabbrini Marco , Fantaccione Luca , Pucciarelli Martina , Serra Angela , Ragni Giacomo , Fantozzi Francesco
Published: September 2023

Turbomachinery design typically foresees three different phases: conceptual, preliminary and detailed. Conceptual design is the first stage of industrial design process, providing mainly the architectures down-selection. Traditionally, this phase is driven by the target “performance” as the main goal to be achieved. Therefore, the design team sketches an early configuration looking at this goal. Performances can be affected by material and geometry changes, manufacturing technology and engine architecture. Conceptual design phase is dramatically important, as the outcome of the down selection will not only affect performances, but also other important parameters like ”cost” and “environmental impact”. Moreover, in conceptual phase the configuration is still under definition and the designer has the highest flexibility in defining and then designing the product. Cost and environmental sustainability are comparable to performance as drivers in industrial design process from the earliest stage. Connections between performance, cost and carbon footprint (CF) are fundamental in decision making and down-selection process. Usually, cost estimations are tailored to each design and technical requirements, to give an assessment of the costs from the buyer’s point of view. Assessment of the environmental impacts can be carried out by means of the Life Cycle Assessment (LCA) methodology (ISO 14040: 2006, ISO 14044:2006), looking at the whole life cycle of the product. Therefore, as boundary definition can be different, there is a possibility that cost estimation and LCA results are not consistent with each other due to different system boundaries, leading to misinformed decisions. To overcome this issue, the principles underlying the environmental Life Cycle Costing (e-LCC) method can be used (Hunkeler et al. 2008). It integrates both LCA and LCC studies, based on the same functional unit and system boundaries.

This article will present a case study of a supercritical CO2 turboexpander inner casings’ subsystem conceptual design and architecture down selection to propose an approach for maximizing product’s sustainability and performance. Results show the relevance of the geographical location of suppliers on the CF, as well as how small changes on the overstock materials could lead to a relevant change in costs.
POD-Based Surrogate Modeling Approximation for Aeroengines Nonlinear Unbalance Responses
Authors: D’Alessandro Francesco , Festjens Hugo , Chevallier Gael , Cogan Scott , Benamara Tariq , Sainvitu Caroline
Published: September 2023

FE models to simulate aeroengines rotordynamics become more and more complex thanks to the improvement of computational resources. Numerical simulations for industrial scale applications are nevertheless expensive in terms of computational effort because of their size and the presence of nonlinearities. In many-query frameworks (sensitivity or reliability analysis, model calibration, etc.), parametric studies have to be performed and the FE models are generally simplified or strongly reduced with a consequent loss of accuracy.

Recent machine learning methods can be employed to build faster-to-evaluate surrogates of the original model. Nevertheless, this type of offline approach can be very demanding in terms of number of full order evaluations to reach a sufficient accuracy. The challenge is therefore to control the burden associated to the evaluation of the DoE and the surrogate model training phase.

This work presents a surrogate modeling technique to quickly and accurately reproduce the nonlinear unbalance responses of industrial scale rotor-dynamical models submitted to rotor-stator contact. About 20 DOFs of the industrial FEM are considered in this work and a POD-based approximation (surrogate modeling technique known as POD-SM or non-intrusive POD in the literature) of their frequency dependent unbalance response are presented. In order to analyse the modeling uncertainties of a specific shaft’s support of a modern aeroengine, its dynamical parameters (stiffness, damping, nonlinear contact parameters) are studied within a specific variation range, defining the design space covered by the present study.
Design and Performance Assessment of an Experimental Rig to Conduct Material Nitridation Studies at Extreme Ammonia Conditions
Authors: Laws Nicole , Campuzano Felipe , Dawood Ziad , Roberts William L.
Published: September 2023

This work presents the design and assessment of an experimental rig intended to carry out material sustainability studies in ammonia (NH3) environments. The designed facility aims at furthering the understanding of the nitridation potential of NH3 under extreme conditions, particularly at both high pressure and high temperature, when interacting with varying materials of interest. Several key factors were considered during the design process, including a system capable of operating at high pressures (up to 30 bar) and temperatures (up to 800 °C), the possibility of maintaining a continuous NH3 flow to increase the nitridation potential of the atmosphere, the flexibility of accommodating between 60 to 70 metal samples, and the design of a suitable system to operate continuously for hundreds of hours (up to 1000 hours in total). A facility achieving those features involved the development and optimization of three main subsystems such as a liquefied NH3 feeding system, a high-pressure/temperature rig, and an abatement system. Altogether these guarantee safe and continuous operation for long periods of time at the desired experimental conditions. Finally, several tests were conducted to assess the reproducibility and stability of the designed facility, including temperature and pressure profiles, and NH3 concentration gradients in the rig.
The Effect of Meter-Diffuser Angular Offset on Film Cooling Hole Adiabatic Effectiveness
Authors: Lundburg Evan , Lynch Stephen , Liu Kevin , Xu Hongzhou , Fox Michael
Published: September 2023

Turbine blades and vanes are manufactured with shaped film cooling holes to deliver coolant to the high temperature surfaces to improve blade life and durability. A shaped film cooling hole consists of a cylindrical meter section followed by a shaped diffuser. When the meter and diffuser sections are manufactured in two-step processes, a meter-diffuser angular offset can occur. Past studies have shown that linear meter-diffuser offsets in the spanwise direction will reduce adiabatic effectiveness. In addition, the geometry of a meter-diffuser angular offset is similar to the effect of film cooling holes at a compound angle, where the diffusion of the film cooling hole flow is angled away from the mainstream flow. However, the sensitivity of an angular offset has not been investigated. This study utilizes 10-10-10 expansion angle film cooling holes that are unchanged except for a meter-diffuser angular offset of 5° and 10°. The film cooling hole meter remains aligned with the mainstream. To mimic the coolant delivery method used in turbine vanes, a coolant channel provided co-flow and counterflow feed to the film cooling holes. Each geometry was tested at three blowing ratios as well as in co-flow and counterflow coolant feed. Adiabatic effectiveness measurements indicate that a 5° meter-diffuser angular offset did not significantly reduce performance. The angular offset of 10° reduced performance at blowing ratios greater than one, due to the coolant on the wall following the direction of the metering section. Roughness effects were also investigated for the 5° offset. When compared with roughness effects and diffuser cross-sectional shape effects, the 5° offset provided the least impact to performance. Thus, it is expected that manufacturing angular alignment errors are less significant than errors in shape, with roughness providing the most significant impact to performance.
Water Enhanced Turbofan: Improved Thermodynamic Cycle Using Hydrogen as Fuel
Authors: Görtz Alexander , Häßy Jannik , Schmelcher Marc , El-Soueidan Mahmoud
Published: September 2023

Revolutionary developments are needed to drastically reduce emissions of aviation. Two promising approaches are hydrogen combustion and the water enhanced turbofan (WET). Heat exchangers are needed for both concepts. Whereas for hydrogen combustion, it is necessary to bring liquid hydrogen to operating temperature, the WET requires an evaporator for water and a condenser to extract it from the exhaust flow. Although both technologies may contribute to the mitigation of climate impact individually, it makes sense to combine them in the long term. Unfortunately, it is not known to what extent these approaches can be combined but there is potential for synergy. In this work, a hydrogen-fueled WET is compared with a kerosene-fueled WET. The design approach is described and the interaction of both technologies is investigated. While the thrust specific energy consumption is reduced by 2.2 % when switching to hydrogen, it is also possible to reduce the additional water tank mass by 40 %.
Evaluation of Water-Cooling Effect in Hydrogen-Fed SOFC for High-Efficiency Combined System Design
Authors: Kim Hye Rim , Kim Tong Seop
Published: September 2023

If pure hydrogen is used as a fuel in high-temperature fuel cells, waste heat must be removed by air cooling, which requires increased power consumption for supplying excess air. This study presents a hydrogen-fed solid oxide fuel cell (SOFC) that uses water instead of air for stack cooling and improved system performance. A novel SOFC system with energy cascade utilization is also proposed using cooling water as the working fluid for a steam turbine. Water cooling for the SOFC stack cooling reduced the stack power and efficiency but significantly reduced the power consumption for supplying excess air by more than 60%. Under ambient SOFC operating pressure, the net power and efficiency of the proposed system were increased by 25.6% and 12.2%p compared to the air-cooled system, respectively. At an SOFC operating pressure of 1000 kPa, the proposed hybrid system with energy cascade utilization achieved improvements of 10.2% in net power and 7.5%p in net efficiency, leading to efficiency higher than 73%. This study is significant in that it proposes a novel high-efficiency SOFC system with energy cascade utilization by using two-phase water as a cooling medium and working fluid of steam turbine.
Performance Investigation of Stator-Less and Blade-Less Radial Expander
Authors: Renuke Avinash , Traverso Alberto , Reggio Federico , Pascenti Matteo , Silvestri Paolo
Published: September 2023

Interests in small-scale turbomachinery are gaining momentum, particularly around waste heat recovery using Organic Rankine Cycle (ORC), energy harvesting, pico-hydro, refrigeration and heat pumps and small-scale power generation. These applications demand to have economical, simple construction, and reasonably efficient machines. The performance of bladed turbomachine at a small scale is poor mainly due to viscous losses and relatively large clearances. In some cases, like ORC, it requires a lubrication system, making it complex and costly. Bladeless or Tesla turbomachinery is seen as one of the solutions for these applications due to its simple construction and cost-effectiveness. However, the experimental efficiency of the bladeless turbines/compressors is found in the low region, < 40%. In this article, the performance of a bladeless turbine is investigated using a vaneless volute configuration, making the turbine stator-less (vaneless volute) and bladeless (vaneless rotor). This study presents numerical and experimental performance investigation with a volute as a stator of the bladeless rotor. 3D Numerical results show very promising performance of the turbine with total to static efficiencies calculated above 65%. In the second part of the article, turbine prototype components, assembly and test set-up are discussed. Experimental maximum efficiency of 41.5±0.88% at 3.5 kg/s@5000 rpm and power of 915 W is obtained. This is the highest recorded efficiency for the Tesla turbine in peer-reviewed research. The overall turbine performance from 3D numerical simulation with ventilation and mechanical losses is compared with experimental results. This work demonstrates that the proposed stator-less/volute configuration provides an efficient way for bladeless or Tesla turbines, particularly for low-head applications.
Optimization of Variable Geometry Turbine Electric Turbocharger for a Heavy-Duty, On-Highway Fuel Cell
Authors: Taylor Alexander H. , Naik Pavan , Nibler Simon , Al-Hasan Nisar
Published: September 2023

An air compressor is a necessary component on fuel cell electric generators as fuel cells do not pull in air without an external intervention. There are many fuel cell air compression options, each with their own benefits and drawbacks, such as roots-style screw compressors, radial e-compressors, e-turbos with wastegate, and e-turbos with a variable geometry turbine (VTG). Turbocharger turbine wheels for internal combustion engine applications are optimized to maximize exhaust gas enthalpy extraction while limiting centrifugal forces in the blades. In the presence of high temperature exhaust gas, 950–1050° C for gasoline engines, material strength decreases, elasticity increases, and thus induced stresses must be reduced to prevent turbine failure or contact with the turbine housing. The proton exchange membrane fuel cell (PEMFC) exhaust gas temperature is significantly lower, in the range of 85–90° C, which enables more degrees of freedom in the design and thereby a higher thermodynamic efficiency of the turbine. This work proposes a variable geometry turbine specifically for the fuel cell environment, and compares system performance through 1-D simulations at a lower-power road load and rated power point, to i) baseline electric compressor (e-compressor), ii) electric turbo (e-turbo) with wastegate turbine, & iii) e-turbo with VTG designed for an IC engine environment. The VTG turbine optimized for fuel cell enthalpy harvesting has 13%-points higher efficiency at rated power compared to that of a typical ICE VTG, a relative increase of 23%. This study finds an optimized VTG e-turbo improves PEMFC efficiency at rated power by 3%, or 1.5%-points, compared to the e-compressor without a turbine.