bluuebunny/crossref_metadata_2025 huggingface dataset:
Defect detection in laser-based powder bed fusion process using machine learning classification methods
Authors: Akmal Jan , Macarie Mihai , Björkstrand Roy , Minet Kevin , Salmi1 Mika
Published: December 2023

The aim of this study is to deploy machine learning (ML) classification methods to detect defective regions in additive manufacturing, colloquially known as 3D printing, particularly for the laser-based powder bed fusion process. A custom-designed test specimen composed of 316L was manufactured using EOS M 290 machine. Multinomial logistic regression (MLR), artificial neural network (ANN), and convolutional neural network (CNN) classification techniques were applied to train the ML models using optical tomography infrared images of each additively manufactured layer of test specimen. Based on the trained MLR, ANN, and CNN classifiers, the ML models predict whether the manufactured layer is standard or defective, yielding five classes. Defective layers were classified into two classes for lack of fusion and two classes for keyhole porosity. The supervised approach yielded impeccable accuracy (>99%) for all three classification methods, however CNN inherited the highest degree of performance with 100% accuracy for independent test dataset unfamiliar to the model for unbiased evaluation. The high performance and low cost of computing observed in this work can have the potential to detect and eliminate defective regions by tuning the processing parameters in real time resulting in significantly decreased costs, lead-time, and waste. The proposed quality control can enable mass adoption of additive manufacturing technologies in a vast number of industries for critical components that are design- and shape- agnostic.
Digital manufacturing in laser powder bed fusion of aluminium alloy safety feature for EV battery cell
Authors: Saariluoma Heikki , Vesterinen Kalevi , Salminen Antti
Published: December 2023

Recently, a new way to produce prismatic Li-ion battery cell’s lid part for Battery Electric Vehicles (BEV) was presented, with integrated cell thermal management, based on the Laser Additive Manufacturing (LAM) method. In the solution, the safety vent protects the battery cell from unpredictable explosions caused by the increasing internal pressure. Additive manufacturing allows integrating the feature to the cell lid part and significantly decreases the process steps in manufacturing and increases the production efficiency. Aluminium powder materials for the used Laser Powder Bed Fusion (LPBF) method have relatively high tensile strength, which causes the need for minimum layer thickness for the safety vent. Reliability of producing such a thin layer as a gas tight structure is challenging and several procedures were studied. Material with lower tensile strength and higher elongation ability was tested during the second phase. The challenge is to produce such a thin wall thickness, which breaks at the pressure level of one MPa and opens the valve. The design is based on FEM analysis with constant equivalent strain theory to optimize safety vent dimensions. The pressure test was performed to measure the rupturing pressure of the thin aluminium LPBF layer as materials in normal mode and in annealed mode. The constant equivalent strain theory for estimate rupture pressure was in fine agreement with the experimentally measured ones, even with a maximum error rate. The results show that the manufacturing method is possible for such automotive mass production parts and when comparing different stacking strategies, it showed a great influence in the productivity of such parts’ production.
Development of a build volume reduction kit for studying epitaxial re-solidification in laser powder bed fusion
Authors: Norouzi-Inallu M. , Laitinen V. , Poutiainen I. , Ullakko K.
Published: December 2023

Laser powder bed fusion (PBF-LB/M) is a promising additive manufacturing process that enables the production of complex and high-performance parts. However, the high cost of materials and the need for large quantities of powder in conventional industrial-grade systems pose challenges for experimental materials development and testing activities. This study focuses on the development of a modular build volume reduction kit for an existing EOS EOSINT M-series PBF-LB/M machine. The proposed build volume reduction kit can be customized and adapted for specific research needs, expanding the capabilities of existing infrastructure without significant capital investment. This study describes the design and characterization of the build volume reduction kit and a detachable Pt-heater module, which allows for preheating of the substrate material above 500 °C. The kit’s operation was validated by manufacturing simple cuboid samples using EOS 316L stainless steel powder on a 316L stainless steel substrate. The results demonstrate the feasibility of using the reduction kit for cost-effective experimental investigations, as well as highlighting its potential for studying the epitaxial solidification of PBF-LB/M-built functional materials.
Optimized Inconel 718 pressure vessel manufactured with laser powder bed fusion
Authors: Tepponen V , Westman S , Nyamekye P , Poutiainen I
Published: December 2023

Laser powder bed fusion (L-PBF) is one of the most novel additive manufacturing methods used for a wide range of industrial grade metallic materials. The process can produce end-use metal parts with desirable qualities and mechanical properties. L-PBF however, remains a complicated and expensive manufacturing method. Design for additive manufacturing (DfAM) is a key aspect leveraging the uptake of advantages and possibilities offered by AM in augmenting its competitiveness against conventional manufacturing (CM) methods. Inconel 718 (IN718) is a nickel-based superalloy boasting high temperature strength, good oxidation, and corrosion resistance at elevated temperatures. IN718 is commonly used for high performance applications, such as power and process industry parts, and gas turbine components. High inherent toughness, hardness, work hardening, and low thermal conductivity properties make the material difficult to manufacture through conventional machining methods. The layer-by-layer building of powder metals via L-PBF makes it possible to build different geometrical intricacy. The offered manufacturing flexibility for complex high-end metal structures for variety of applications makes L-PBF an alternative manufacturing method for high performance metals. This study investigates use of DfAM for a small-scale pressure vessel with predefined geometry, dimensions, design space and load condition. The aim is to introduce and exploit contemporary design optimization methods and their feasibility with AM. Structures, such as lattices and stress field driven geometries based on finite element analysis are investigated in this study. The designs are virtually tested under predefined pressure load of 50 bar. All four design options are manufactured on EOS M290 and IN718 powder. The result of the study shows the different optimizations decrease weight and improve material savings without compromising the linear load capacity. Optimized designs could also be made in such a way that it does not increase the manufacturing duration or add additional steps to it.
Validation of powder layering simulation via packing density measurement for laser-based powder bed fusion
Authors: Haapa E , Gopaluni A , Piili H , Ganvir A , Salminen A , Ottelin J
Published: December 2023

Powder bed fusion using a laser beam (PBF-LB/M) is considered one of the most versatile additive manufacturing methods as the parts printed have high resolution thanks to the low layer thickness used. The powder packing density (PD) of the powder layer has a significant impact on the density, surface roughness and other mechanical properties of the built parts. Due to the difficulty of characterizing the powder bed in situ, simulation has often been used to study the powder behavior on the powder bed. However, in order for the simulation to have practical value, there must be some way of confirming the results via experimental methods, also called validation. The aim of this study was to develop a powder packing density-based validation method for a powder bed simulation. The developed method featured a simplistic “open cup” style sample which traps powder inside for PD measurement. The samples were built with an EOS M 290 PBF-LB/M system using Alloy 718 (also known as “IN718” or “Inconel”) powder. Average PD over the five built samples was 52.4 %, with a standard deviation of 0.2 %. The method was used to successfully validate a powder bed simulation with four recoated powder layers, modelled using FLOW-3D DEM simulation software from Flow Science Inc. Similar methods for PD characterization were found in literature, but in many cases the method does not fully correspond to the conditions of a simulated powder bed, the scale is very small, or the reliability of the PD measurement is not confirmed. The method presented in this study corresponds to typical powder bed simulation conditions, while retaining high reliability and repeatability of results.
Bioinert ceramics scaffolds for bone tissue engineering by laser-based powder bed fusion: a preliminary review
Authors: Kamboj N , Piili H , Ganvir A , Gopaluni A , Nayak C , Moritz N , Salminen A
Published: December 2023

The implementation of laser powder bed fusion (PBF-LB) on ceramics is far more demanding than their metallic and polymeric counterparts for bone tissue engineering (BTE). The review will shed light on bioinert ceramics-based biomaterials manufacturing through PBF-LB incorporating alumina and yttria-stabilized zirconia as oxide-based ceramics and nitride-based ceramics as non-oxide-based ceramics with particular prominence on their properties and requirements for biomedical devices and BTE. The review paper will also classify bioinert scaffolds processed through PBF-LB as a medium to manufacture drug delivery systems (DDS) and to ameliorate critical-sized bone defects based on the fracture site length of the bone with the various modes of functionalization through the incorporation of drugs, stem cells, and growth factors for personalized medicine.
Additive manufacturing systems integration
Authors: Heilala J , Parchegani S , Piili H
Published: December 2023

This research explores real-time database systems’ evolution, focusing on unique features and the addressed challenges. It examines the role of multi-material additive manufacturing quality domain databases in innovation and maintaining standards. It also looks at the challenges of implementing quality manufacturing systems from a technology, organization, and people of European Manufacturing research perspective. The study offers a new perspective on reconfigurable intelligent surfaces with multi-material additive manufacturing with system integration, discussing its applications and digital products’ transformative potential. Enhancing multi-material additive manufacturing capabilities redefines the industries, creating a strong communication culture by adopting quality integration of quality and robotics while exploring the future of mathematics complexity in optimizing manufacturing education. The paper also explains the statistical classification of historical technology in manufacturing engineering education by flagging the platform‘s role of opportunities in secure research collaboration. The manufacturing horizontal is essential for effectively managing the multi-material additive manufacturing system through advanced technology to quality management integration. Certified advanced training and competency development econophysics show the multi-material additive manufacturing systems development influence on the production theories and mechanics of complex electronics. To enable, for example, communication links and cellural multi-material additive manufacturing integrations research for new technologies.
Effects of laser welding speed on the microstructure and microhardness of ultra-high strength steel S1100
Authors: Afkhami S , Ghafouri M , Lipiäinen K , Poutiainen I , Amraei M , Björk T
Published: December 2023

Ultra-high strength steels strengthened via thermomechanical processing and low alloying constituents are currently quite popular for industrial applications. The popularity is primarily due to these steels being relatively economical compared with their high-alloy rivals, making them feasible to provide significant strength-to-weight ratios with reasonable costs in steel structures. However, welded joints in most steel structures cannot be avoided, and ultra-high strength steels, due to their thermomechanical strengthening mechanisms, are prone to loss of strength, toughness, or ductility after welding. Also, due to the ultra-high strength levels of the base metals, providing a suitable filler material with mechanical properties comparable to those of the base metals for filling the joint gap seems challenging. Accordingly, laser welding can be a relatively more suitable approach than arc welding to weld ultra-high strength steels, considering its easier control over the weld heat input, joint shape, and the possibility of welding without the requirement of filler metals. Therefore, this study investigates the influence of travel speed and its subsequent change in heat input of laser welding on the joint shape, microstructure, and hardness of the S1100 low-alloy carbon steel, one of the most commonly used ultra-high strength steels in modernized steel structures.
Impact of laser beam shaping on weld pool and seam geometry in butt-joint welding with filler wire
Authors: Mi Y , Sikström F , Nilsen M , Joshi S , Guglielmi P , Palumbo G , Ancona A
Published: December 2023

Beam shaping offers a promising solution to address various challenges in laser-based processes. This study explores the use of an adaptive beam shaping solution using a deformable mirror for high-power continuous wave lasers. Specifically, the impact of three different elliptical beam shapes on weld pool geometry, weld cross section in butt-joint welding with a filler wire is investigated. The results reveal that beam shaping significantly affects the weld pool and cross section, with elliptical beam shapes resulting in wider fusion zones in two tested cases and more uniform weld bead compared to a typical circular beam. These findings highlight the potential of beam shaping for enhancing consistency and quality in laser beam welding.
Influence of shielding gas on filler wire mixing at laser hybrid welding of thick high strength steels
Authors: Üstündag Ömer , Kampffmeyer Dirk , Wolters Michael , Bakir Nasim , Gumenyuk Andrey , Rethmeier Michael
Published: December 2023

The laser hybrid welding process offers many advantages during welding of thick-walled steels, such as the increased penetration depth and, thus, reduced number of layers, reduced heat input and decreased distortion compared to arc-based welding processes. Especially, when welding high-strength steels (HSS), the reduced heat input plays an essential role. However, a major challenge when laser hybrid welding of thick-walled steels is the limited filler wire mixing over the entire seam thickness, which can lead to changed mechanical properties over the depth. To overcome this issue, the add of oxygen into the shielding gas and its influence on the filler wire mixing and finally to the mechanical properties were investigated within this work. Therefore, 20 mm thick S690QL steels were laser hybrid welded in a single-pass. A contactless electromagnetic backing was used to avoid sagging. The admixture of oxygen was performed by a gas mixer, where the oxygen content was varied between 0 % and 7.2 %. The experiments were also accompanied by laser beam welding tests in steel/glass configuration, where the melt pool geometry as well as the melt flow characteristics were captured by a high-speed camera. It can be concluded, that adding of approx. 4 % oxygen into the shielding gas had a positive effect on the filler wire mixing, were up to a depth of 18 mm elements of the filler wire could be observed.
The effects of laser welding parameters on weldability and quality of the microstructure of additively manufactured Inconel 718-316L joints
Authors: Kivirasi E , Lindqvist M , Lipiäinen K , Piili H , Salminen A
Published: December 2023

Additive manufacturing of metals is a way of producing high-quality end-use parts. Technical alloys, for example Inconel 718, can be used to obtain a lot of benefits for example wear, corrosion, and heat resistance. Laser welding of Inconel 718 is a standard process, but there is rather limited amount of information of welding of additively manufactured nickel superalloys to the additively manufactured stainless steel. The process parameters need to be considered in laser welding. Undesired microstructure can occur due to wrong heat input during the welding process. This study examines laser welding of additively manufactured Inconel 718-316L parts and the effects of the welding parameters to the quality of the weld by analysing microstructure from the heat affected zone. This is done to achieve better part quality more cost efficiently compared to traditionally produced parts and to optimize the welding parameters. It is not feasible to manufacture the full large structure with IN718 and AM could be used to manufacture just the functional parts of the assembly. Tests have shown that welding heat input and cooling time affect to the quality. Inconel 718 hardness decrease across the fused zone because of the mixing of different elements in the molten weld pool. Laser welding highlights cuboidal shaped niobium rich carbides throughout the material to the heat affected zone grain boundaries on Inconel side.
Coaxial Wire Laser-based Additive Manufacturing of AA7075 with TiC Nanoparticles
Authors: Meneses W , Tuominen J , Ylä-Autio A , Wiikinkoski O , Sabr A , Peura P
Published: December 2023

AA7075 is a heat treatable aluminium alloy widely used in aerospace and automotive applications due to its outstanding high strength-to-weight ratio. However, the implementation of this alloy in Additive Manufacturing (AM) processes has been limited due to its susceptibility to hot cracking. Moreover, selective evaporation of low boiling point elements Zn and Mg can cause gas porosity and diminish the mechanical properties of AM parts. Recent research revealed the effectiveness of nanoparticles additives to change the solidification behaviour of high-strength aluminium alloys and improve their weldability/printability. In this study, AA7075 enhanced with TiC nanoparticles was utilized as wire feedstock to create single and multi-layer samples with coaxial laser-directed energy deposition (L-DED). The response of the samples to precipitation hardening was studied, evaluating the microstructure and the microhardness before and after T6 heat treatment. Specimens were characterized using optical and electron microscopy and electron backscatter diffraction (EBSD). Crack-free and virtually porosity-free samples were fabricated, which exhibit a refined equiaxed grain structure with grain size <10μm. This confirms the ability of TiC nanoparticles to prevent columnar dendritic growth and promote heterogeneous nucleation. Microhardness values increased by 51 HV after T6 heat treatment and were uniform across the sample. Energy Dispersive Spectroscopy (EDS) analysis showed that there are evaporation losses of Zn and Mg. Considering the boiling temperatures of these elements, it is inferred that the molten pool reaches temperatures above 1090°C, and the partially melted zone temperature is between 907°C and 1090°C.
Temperature and distortion in laser melt injection of MMC wear-resistant coatings in a copper beryllium alloy
Authors: Bohlen A , Langebeck A , Seefeld T
Published: December 2023

Wear-resistant coatings made of MMC materials (metal matrix composites) are ideal for increasing the service life of tools subjected to high abrasive stresses. Such MMC surfaces can be produced by laser melt injection during the manufacturing process of the tools or subsequently as a retrofit near-net-shape. However, during laser melt injection (LMI) thermally induced residual stresses can be introduced into the MMC surfaces. These can have a detrimental effect on the service life of these surfaces and thus reduce the positive effect of wear resistance.

In order to determine the influence hard particles injected during LMI have on residual stresses within the surface layer the distortion of the surface layer was evaluated. MMC layers consisting of a copper beryllium matrix and fused tungsten carbide hard particles were created by LMI. The MMC layers are compared to parts with remelted surfaces. Laser power and process velocity were varied to examine their influence on distortion. The process temperature was recorded on the melt pool by a two-color pyrometer. After the process the top layer of the MMC surface was cut off by wire EDM and then measured with a coordinate measuring machine. It is shown that an increase of incorporated powder mass per unit length and process temperature lead to higher distortions.
The properties of laser-clad coatings made of NiCrBSi alloy and recycled tungsten carbides
Authors: Tuominen J , Näkki J
Published: December 2023

Tungsten carbide hard metals are one of the most known and successful powder metallurgical products used in environments where severe wear conditions prevail. Since tungsten belongs to the list of critical raw materials for the European Union (EU), its recycling is highly desirable. In this paper, recycled tungsten carbide powders fabricated by the zinc-reclaim process where mixed with NiCrBSi matrix and deposited with one-step laser cladding using a coaxial powder feeding on mild steel substrates. Prepared clads were tested in low-stress rubber wheel abrasion tests and compared with clads produced from commercial macrocrystalline (WC) and cast and crushed eutectoid WC/W2C reinforced clads. The results showed that recycled WC induced porosity in clads when produced with ‘production’ laser cladding parameters due to small carbide size resulting in poor wear performance. When laser-clad with lower heat input and productivity, pore-free clads with excellent wear performance were obtained.
A Laser Forming Study on Time and Energy Efficiency
Authors: Nikolov Georgi Nikolaev , Thomsen Anders Noel , Kristiansen Morten
Published: December 2023

Laser forming is a relatively slow process utilizing temperature differences in the material to cause plastic deformation. The process requires dwell time between laser passes to cool down the material, which results in a slow production rate. Not fully cooling the workpiece has been shown to give a higher bend rate per unit of time. This, coupled with the cooling rate at higher temperatures being more pronounced permits examining the efficiency of laser forming while working in different temperature ranges. The presented work experimentally explores different temperature ranges for AISI 304 from 20 to 1300°C using a thermal camera. Therefore, for each temperature range, the workpiece is heated and cooled to a achieve a constant peak temperature. The purpose is to compare the bend rate per unit of time with different temperature ranges and to examine overall time efficiency. Finally, since different power levels are utilized for each temperature range, the total energy used to achieve each bend will also be investigated. The results show that the increased formability and rate of cooling at higher temperatures increase efficiency in terms of total time. While efficiency in terms of the equipment is higher when allowing the workpiece to fully cool.
Correlation of signal feature importance and process parameters in water jet-guided laser cutting
Authors: Richter Roland Axel , Braunmüller Falk , Pandiyan Vigneashwara , Shevchik Sergey , Ivas Toni , Zryd Amédée
Published: December 2023

Laser-based cutting can deliver high accuracy and speed during the process. However, there are still some technical challenges to be solved. First, the process itself requires precise focusing of the laser beam. When using continuous wave (CW)- or pulses in the μs- to ns-range for efficient materials removal, not only the targeted material volume is heated, but also the surrounding material due to heat diffusion. This decreases the quality of the cut. Coupling the light into a water-jet solves both issues: It ensures the delivery of focused light to the target surface, while cooling the affected material during processing. This work proposes a real-time monitoring system of the cutting process by exploiting unique physical phenomena related to the process. The water jet allows both the propagation of laser light towards the target while keeping it focused and the back-propagation of process light through the focusing system. This can be captured using suitable sensors, and saved using a data acquisition system. The acquired data can be used for process characterization using signal processing. In this work we demonstrate the direct correlation between different process parameters and statistical signal features. We show that reducing the signal to a few statistical features both in time and frequency by feature extraction does not reduce the information content, but instead makes it more robust to mis-classification while decreasing the classification time. It also opens up a wide range of future applications not only to process data, but also to control the process more precise.
Health-system specialty pharmacy: Overview of a hybrid clinical model
Authors: Meadors Crystal , McPheeters Chelsey , Maier Chelsea , O’Reilly Emily
Published: December 2023

Purpose

The prevalence of specialty pharmacies has grown, especially within the hospital setting. These pharmacies have shown benefits in the areas of patient education and adherence, financial support, and patient and provider satisfaction. Currently, there are gaps in literature describing use of a hybrid clinical model in health-system specialty pharmacies.

The UofL Health – UofL Hospital Specialty Pharmacy (UofL Health SP) is attached to a retail pharmacy in a larger health system. Pharmacists in the UofL Health SP utilize a hybrid clinical model in which they split their time between working in a specialty clinic and staffing in the specialty pharmacy. The specialty pharmacy and its oncology satellite pharmacy each have a primary staffing pharmacist, and 5 other pharmacists participate in this hybrid clinical model. In addition to the specialty pharmacists, pharmacy technicians and patient care advocates support the operations of the specialty pharmacy and ensure financial access to medications for patients.

Conclusion

With the hybrid clinical model at UofL Health SP, there is increased workflow efficiency and better communication between specialty clinics and the specialty pharmacy, which results in a streamlined patient experience. Additionally, there has been an increase in specialty pharmacy prescriptions dispensed in the specialty pharmacy since the implementation of this hybrid clinical model.
Recent and anticipated novel drug approvals for 2023 and 2024
Authors: Rim Matthew H , Karas Brittany L , Barada Farah , Levitsky Andrew M
Published: December 2023

Purpose

Health-system pharmacists play a crucial role in monitoring the pharmaceutical pipeline to manage formularies, allocate resources, and optimize clinical programs for new therapies. This article aims to support pharmacists by providing updates on new and anticipated novel drug approvals.

Selected drug approvals anticipated in the 12-month period covering the fourth quarter of 2023 through the third quarter of 2024 are reviewed. The analysis emphasizes drugs selected from 58 novel drugs awaiting FDA approval that are expected to have significant clinical and financial impact in hospitals and clinics. The pipeline includes recently added drugs with various indications, including oncology, infectious diseases such as complicated urinary tract infection and pneumonia, and rare diseases.

Conclusion

Cellular and gene therapies continue to strengthen the pipeline as potential new treatment options for genetic disorders, rare diseases, and cancer. Additional diseases treated by new agents include pulmonary arterial hypertension, chronic obstructive pulmonary disease, diabetes, and obesity.
The Looming Future of Private Equity in Plastic Surgery
Authors: Shaffrey Ellen C , Attaluri Pradeep K , Wirth Peter J , Rao Venkat K
Published: December 2023

Private equity acquisition of independent private practices has grown dramatically in the last decade, with private equity firms increasingly investing in surgical specialties that practice in outpatient ambulatory centers. This trend has slowly started to creep into plastic surgery; therefore, understanding the concepts of private equity ownership in healthcare and its benefits and risks is critical. This article provides a fundamental economic background on private equity, describes its current state in healthcare, including trends in plastic surgery, and provides recommendations for plastic surgeons considering private equity acquisition.
In search of strategies for rural revitalization in China: Puhan’s approach to sustainable community development
Authors: Meng Qian , Gray Mel , Bradt Lieve , Roets Griet
Published: December 2023

Despite the central government’s rural reconstruction programme targeting rural villages, rural communities in contemporary China continue to face massive social, economic, and environmental challenges. This paper reports on a case study of a farmers’ cooperative in Puhan. Continual rural decline, alongside national economic reform and rural community development, provide the context for the case study. Well known to rural community development scholars in China, the Puhan cooperative represents an island of rural revitalization in a sea of rural decline. The paper begins with a discussion of the background to the study, the research design and objectives, and participatory observation method employed. Thereafter, it discusses sustainable community development and provides an analysis of the way in which the community development approach facilitates the attainment of sustainable development goals generally and in Puhan in particular. Focusing on the broader context of rural development in the context of national top-down policy-driven change, it examines the Puhan cooperative’s contribution to rural revitalization and the strengths and challenges encountered, given its adoption of bottom-up, grassroots community development. By outlining the lessons learnt from this case study research, the paper aims to enrich knowledge on the community development approach, sustainable community development, and rural revitalization in contemporary China.
Sucrose, NaCl, and citric acid suppress the metallic sensation of FeSO4
Authors: Tansaraviput Sasi , Nolden Alissa A
Published: December 2023

Metallic sensation is often described as unpleasant and can reduce acceptance of foods and beverages and compliance with medication. Masking and suppressing aversive sensations can help to improve acceptance of these products, with many successful strategies identified for bitterness. However, there are few studies investigating effective strategies for suppressing metallic sensation. This study aims to assess the effectiveness of mixture suppression to reduce the metallic sensation elicited from ferrous sulfate and examine whether individual differences in metallic sensation are associated with the effectiveness of suppression strategies. To achieve this, participants (n = 121) reported the intensity of suprathreshold concentrations of ferrous sulfate alone and in binary mixtures with three tastants, specifically, sucrose, citric acid, and sodium chloride. The results revealed that metallic sensation ratings were significantly lower for every binary mixture tested compared to ferrous sulfate presented in isolation. For 0.3 mM ferrous sulfate, sucrose was identified to be the most effective compound in suppressing metallic sensation, followed by citric acid and sodium chloride. For the 1.0 mM ferrous sulfate solutions, all tastants were equally effective at suppressing metallic sensation. In addition, there is a significant interaction between the perceived metallic intensity and the effectiveness of each strategy. These findings suggest that sucrose, citric acid, and sodium chloride have the potential to be effective in suppressing metallic sensation.
Hibernoma: a case report of a rare cardiac tumour
Authors: Cistulli David , Othman Farrah , Karim Rooshdiya , Puranik Rajesh
Published: December 2023

Background

A cardiac hibernoma is a rare phenomenon, with just a handful of reports in the literature. They are difficult to characterize with conventional imaging including echocardiography, computed tomography (CT), cardiac magnetic resonance (CMR), or positron emission tomography (PET). Their definitive diagnosis relies primarily on histopathology via either endovascular or surgical biopsy. Previous case reports have entailed surgical excision followed by histopathology; however, surgery may be unfavourable in some patients with increased perioperative risk.

Case summary

We present the case of a 57-year-old woman who was referred to our cardiology service with an interatrial lipomatous mass found incidentally on chest CT for assessment of rib fractures. She had 6 months of unexplained syncope, which was attributed to superior vena cava (SVC) compression demonstrated by chest CT. The mass had benign characteristics on echocardiography, CT, and CMR but was glucose-avid on PET, which indicated a possible malignancy such as liposarcoma. Her comorbid and very significant airways disease precluded her from surgical excision, so instead, endovascular biopsy was performed. Histopathology showed brown fat which was negative for mouse double minute 2 amplification on fluorescence in situ hybridisation testing; hence, a diagnosis was made of hibernoma, a rare benign tumour of brown fat. Given the benign diagnosis and her surgical risk with severe chronic obstructive pulmonary disease, a multidisciplinary recommendation was made favouring conservative management, with careful ongoing follow-up and the consideration of SVC stenting if symptoms progressed.

Discussion

The definitive diagnosis of a cardiac hibernoma is complex and relies heavily on histopathology due to the contradictory findings on chest imaging. Careful consideration of management within a multidisciplinary team setting is essential to achieve a successful outcome.
Aortic arch shape after arch repair predicts exercise capacity: a multicentre analysis
Authors: Mandell Jason G , Romanowicz Jennifer , Loke Yue-Hin , Ikeda Nobuyuki , Pena Emily , Siddiqi Umar , Hibino Narutoshi , Alexander Mark E , Powell Andrew J , Olivieri Laura J
Published: December 2023

Aims

Coarctation of the aorta is associated with long-term morbidity including decreased exercise capacity, despite successful repair. In the absence of discrete recoarctation, the haemodynamic mechanism remains unknown. This multicentre study evaluated the relationship between aorta shape, flow, and exercise capacity in patients after arch repair, specifically through the lens of aortic size mismatch and descending aortic (DAo) flow and their association with exercise.

Methods and results

Cardiac magnetic resonance, cardiopulmonary exercise test, and echocardiogram data within 1 year were analysed from 58 patients (age 28 ± 10 years, 48% male) across four centres with history of isolated arch repair. Aortic arch measurements were correlated with % predicted VO2max with subgroup analyses of those with residual arch obstruction, bicuspid aortic valve, and hypertension. Ascending aorta (AAo) to DAo diameter ratio (DAAo/DDAo) was negatively correlated with % predicted VO2max. %DAo flow positively correlated with VO2max. Sub-analyses demonstrated that the negative correlation of DAAo/DDAo with VO2max was maintained only in patients without arch obstruction and with a bicuspid aortic valve. Smaller aortic arch measurements were associated with both hypertension and exercise-induced hypertension.

Conclusion

Aorta size mismatch, due to AAo dilation or small DAo, and associated decreased %DAo flow, correlated significantly with decreased exercise capacity after aortic arch repair. These correlations were stronger in patients without arch obstruction and with a bicuspid aortic valve. Aorta size mismatch and %DAo flow capture multiple mechanisms of altered haemodynamics beyond blood pressure gradient or discrete obstruction and can inform the definition of a successful repair.
Clinical features of anti-pituitary-specific transcription factor-1 (PIT-1) hypophysitis: a new aspect of paraneoplastic autoimmune condition
Authors: Urai Shin , Iguchi Genzo , Kanie Keitaro , Bando Hironori , Yamamoto Masaaki , Oi Yuka , Kashitani Yuya , Iida Keiji , Kanzawa Maki , Fukuoka Hidenori , Takahashi Michiko , Shintani Yasushi , Ogawa Wataru , Takahashi Yutaka
Published: December 2023

The pathogenesis of anti-pituitary-specific transcription factor-1 (PIT-1) hypophysitis was gradually revealed as cases emerged. Our comprehensive analysis, including all reported cases, identified a new instance of anti-PIT-1 hypophysitis postimmune checkpoint inhibitor therapy. All 9 patients exhibited extremely low growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH) levels; 2 had a slightly atrophic pituitary gland; 4 had thymoma, and 5 had malignant neoplasms of diffuse large B-cell lymphoma (DLBCL) and other origins. Patients with thymoma showed multiple autoimmune diseases. HLA-A*24:02 and/or A*02:06 were present in six and DR53 in 5 cases analyzed. High anti-PIT-1 antibody titers and ectopic PIT-1 expression in the cytosol and nucleus of the tumor tissues were observed in patients with thymoma or DLBCL, whereas it was exclusively observed in the nuclei of a bladder cancer patient. These findings provide new insights into the pathophysiology of paraneoplastic autoimmune hypophysitis.
Developmental process of the modern house shrew’s molars: implications for the evolution of the tribosphenic molar in Mesozoic mammals
Authors: Yamanaka Atsushi , Haider Yasin , Morita Wataru , Corfe Ian , Nakamura Norifumi , Goto Tetsuya
Published: December 2023

Phylogenetically, the tribosphenic molars—prototypes of multi-cusped cheek teeth in marsupial and placental mammals—are derived from the single-cusped conical teeth of reptiles through the addition of cusps. Ontogenetically, mammalian molars are formed through the interface between the dental epithelium and mesenchyme (future enamel–dentin junction), becoming geometrically complex by adding epithelial signaling centers, called enamel knots, which determine future cusp positions. To reevaluate cusp homologies in Mesozoic mammals from an ontogenetic perspective, this study tracked molar development in a living placental mammal species, the house shrew (Suncus murinus), whose molars are morphologically the least derived from tribosphenic prototypes. The development of shrew molars proceeded as if it replayed the evolutionary process of tribosphenic molars. The first formed enamel knots gave rise to the evolutionarily oldest cusps—upper paracone and lower protoconid. The order of formation of other enamel knots and their location in development seemed to trace the order of cusp appearance in evolution. The parallel relationship between ontogeny and phylogeny of mammalian molars, if any, suggests that a change in the timing between developmental events rather than a change in the morphogenetic mechanism itself, should have been a major causal factor for the evolutionary transformation of tooth morphology.
The fitness consequences of genetic divergence between polymorphic gene arrangements
Authors: Charlesworth Brian
Published: December 2023

Inversions restrict recombination when heterozygous with standard arrangements, but often have few noticeable phenotypic effects. Nevertheless, there are several examples of inversions that can be maintained polymorphic by strong selection under laboratory conditions. A long-standing model for the source of such selection is divergence between arrangements with respect to recessive or partially recessive deleterious mutations, resulting in a selective advantage to heterokaryotypic individuals over homokaryotypes. This paper uses a combination of analytical and numerical methods to investigate this model, for the simple case of an autosomal inversion with multiple independent nucleotide sites subject to mildly deleterious mutations. A complete lack of recombination in heterokaryotypes is assumed, as well as constancy of the frequency of the inversion over space and time. It is shown that a significantly higher mutational load will develop for the less frequent arrangement. A selective advantage to heterokaryotypes is only expected when the two alternative arrangements are nearly equal in frequency, so that their mutational loads are very similar in size. The effects of some Drosophila pseudoobscura polymorphic inversions on fitness traits seem to be too large to be explained by this process, although it may contribute to some of the observed effects. Several population genomic statistics can provide evidence for signatures of a reduced efficacy of selection associated with the rarer of two arrangements, but there is currently little published data that are relevant to the theoretical predictions.
The gender wage gap among health care workers across educational and occupational groups
Authors: Dill Janette S , Frogner Bianca K
Published: December 2023

Women perform 77% of health care jobs in the United States, but gender inequity within the health care sector harms women's compensation and advancement in health care jobs. Using data from 2003 to 2021 of the Annual Social and Economic Supplement of the Current Population Survey (CPS), we measured women's representation and the gender wage gap in health care jobs by educational level and occupational category. We found, descriptively, that women's representation in health care occupations has increased over time in occupations that require a master's or doctoral/professional degree (eg, physicians, therapists), while men's representation has increased slightly in nursing occupations (eg, registered nurses, LPNs/LVNs, aides, and assistants). The adjusted wage gap between women and men is the largest among workers in high-education health care (eg, physicians, advanced practitioners) but has decreased substantially over the last 20 years, while, descriptively, the gender wage gap has stagnated or grown larger in some lower education occupations. Our policy recommendations include gender equity reviews within health care organizations, prioritizing women managers, and realigning Medicare and Medicaid reimbursement policies to promote greater gender equity within and across health care occupations.
Feasibility of implementing patient-reported outcome measures into routine breast cancer care delivery using a novel collection and reporting platform
Authors: Tsangaris Elena , Hyland Colby , Liang George , O’Gorman Joanna , Huerta Dany Thorpe , Kim Ellen , Edelen Maria , Pusic Andrea
Published: December 2023

Objectives

imPROVE is a new Health Information Technology platform that enables systematic patient-reported outcome measure (PROM) collection through a mobile phone application. The purpose of this study is to describe our initial experience and approach to implementing imPROVE among breast cancer patients treated in breast and plastic surgery clinics.

Materials and Methods

We describe our initial implementation in 4 phases between June 2021 and February 2022: preimplementation, followed by 3 consecutive implementation periods (P1, P2, P3). The Standards for Reporting Implementation Studies statement guided this study. Iterative Plan-Do-Study-Act (PDSA) cycles supported implementation, and success was evaluated using the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework.

Results

Qualitative interviews conducted during the preimplementation phase elicited 4 perceived implementation barriers. Further feedback collected during each phase of implementation resulted in the development of brochures, posters in clinic spaces, and scripts for clinic staff to streamline discussions with patients, and the resolution of technical issues concerning patient login capabilities, such as compatibility with cell phone software and barriers to downloading imPROVE. Feedback also generated ideas for facilitating provider interpretation of PROM results. By the end of P3, 2961 patients were eligible, 1375 (46.4%) downloaded imPROVE, and 1070 (36.1% of those eligible, 78% of those who downloaded) completed at least 1 PROM.

Discussion and Conclusion

Implementation efforts across 2 surgical departments at 2 academic teaching hospitals enabled collaboration across clinical specialties and longitudinal PROM reporting for patients receiving breast cancer care; the implementation effort also highlighted patient difficulties with mobile app-based PROM collection, particularly around initial engagement.
Arthropod and mollusk pests of hemp, Cannabis sativa (Rosales: Cannabaceae), and their indoor management plan in Florida
Authors: Ahmed Muhammad Z , McKenzie Cindy L , Osborne Lance S
Published: December 2023

The first step in developing a pest management strategy is to know which pests can be found on the crop. Recently, the legal cultivation of hemp, Cannabis sativa (Rosales: Cannabaceae), has begun in Florida, and although hemp harbors one of the most diverse pest complexes globally, growers often do not consider the importance of pest identification until it is too late. This study aims to list arthropod and mollusk species reported on hemp in Florida to date. A total of 105 arthropod and mollusk species are reported on hemp in Florida from 8 insect orders and 2 non-insect orders. We found 78 species in Florida already reported in published literature, and 27 species are reported here on hemp for the first time. Even though 105 species in Florida are reported from hemp, not all can reproduce, complete their life cycle, and cause damage to hemp. Therefore, we divided them into 3 categories based on their pest potential: major (26), minor (72), and minor-to-major (7) pests. In addition, we provide representative images, a field guide, and easy-to-follow keys for hemp pest diagnostics. Our study provides the first comprehensive list of hemp pests known to occur in Florida. This will help extension agents, growers, regulators, and researchers scout and inspect hemp regardless of their background and let them know which hemp pest species are commonly found in Florida. We propose and discuss a management plan for pest species on hemp in indoor cultivation with a controlled environment. The pest list and the management plan proposed herein will help aid in the management of hemp pests and the detection of newly introduced hemp pests in Florida.