bluuebunny/crossref_metadata_2025 huggingface dataset:
Habitat restoration weakens negative environmental effects on telomere dynamics
Authors: McLennan Darryl , Auer Sonya K. , McKelvey Simon , McKelvey Lynn , Anderson Graeme , Boner Winnie , Duprez Jessica S. , Metcalfe Neil B.
Published: May 2021

Habitat quality can have far‐reaching effects on organismal fitness, an issue of concern given the current scale of habitat degradation. Many temperate upland streams have reduced nutrient levels due to human activity. Nutrient restoration confers benefits in terms of invertebrate food availability and subsequent fish growth rates. Here we test whether these mitigation measures also affect the rate of cellular ageing of the fish, measured in terms of the telomeres that cap the ends of eukaryotic chromosomes. We equally distributed Atlantic salmon eggs from the same 30 focal families into 10 human‐impacted oligotrophic streams in northern Scotland. Nutrient levels in five of the streams were restored by simulating the deposition of a small number of adult Atlantic salmon Salmo salar carcasses at the end of the spawning period, while five reference streams were left as controls. Telomere lengths and expression of the telomerase reverse transcriptase (TERT) gene that may act to lengthen telomeres were then measured in the young fish when 15 months old. While TERT expression was unrelated to any of the measured variables, telomere lengths were shorter in salmon living at higher densities and in areas with a lower availability of the preferred substrate (cobbles and boulders). However, the adverse effects of these habitat features were much reduced in the streams receiving nutrients. These results suggest that adverse environmental pressures are weakened when nutrients are restored, presumably because the resulting increase in food supply reduces levels of both competition and stress.
Tape stripping and lipidomics reveal skin surface lipid abnormity in female melasma
Authors: Xu Jinhui , lu Haojie , Luo Haixin , Hu Yebei , Chen Yi , Xie Bo , Du Xiaohang , Hua You , Song Xiuzu
Published: May 2021

The skin barrier of melasma is involved in the pathogenesis of melasma. Previous studies have shown that there are differences in the expression of epidermal lipid genes in melasma, but little is known about the epidermis lipid composition of melasma. Compared with the non‐lesional skin, the content of total lipids, phosphatidic acid, phosphatidylserine, and ceramide (Cer) increased significantly in the lesional skin. Multivariate data analysis indicated that 40 individual Cer lipid species were responsible for the discrimination. In terms of acyl chain length in Cer, the expressions of very long chain (VLC) (C20–C26) and ultra‐long chain (ULC) (>C26) increased significantly in the lesional skin. However, Cer[AH] had negative correlations with the activation of melanocytes in the lesional skin. Some lipid species had lower expression in lesional skin with high activation of melanocytes, as well as the high darkness. The epidermal thickness of lesional skin was higher compared with the non‐lesional skin. These results suggest that Cer increased significantly in the lesional skin of melasma, possibly as a compensatory mechanism to maintain skin barrier function. Between different groups of darkness and activation of melanocytes, the change of ceramides might have correlation with the pigmentation progress of melasma.
Participation of keratinocyte‐ and fibroblast‐derived factors in melanocyte homeostasis, the response to UV, and pigmentary disorders
Authors: Upadhyay Parth R. , Ho Tina , Abdel‐Malek Zalfa A.
Published: May 2021

Human epidermal melanocytes play a central role in sensing the environment and protecting the skin from the drastic effects of solar ultraviolet radiation and other environmental toxins or inflammatory agents. Melanocytes survive in the epidermis for decades, which subjects them to chronic environmental insults. Melanocytes have a poor self‐renewal capacity; therefore, it is critical to ensure their survival with genomic stability. The function and survival of melanocytes is regulated by an elaborate network of paracrine factors synthesized mainly by epidermal keratinocytes and dermal fibroblasts. A symbiotic relationship exists between epidermal melanocytes and keratinocytes on the one hand, and between melanocytes and dermal fibroblasts on the other hand. Melanocytes protect epidermal keratinocytes and dermal fibroblasts from the damaging effects of solar radiation, and the latter cells synthesize biochemical mediators that maintain the homeostasis, and regulate the stress response of melanocytes. Disruption of the paracrine network results in pigmentary disorders, due to abnormal regulation of melanin synthesis, and compromise of melanocyte survival or genomic stability. This review provides an update of the current knowledge of keratinocyte‐ and fibroblast‐derived paracrine factors and their contribution to melanocyte physiology, and how their abnormal production is involved in the pathogenesis of common pigmentary disorders.
Defence responses of grapevine cultivars to powdery mildew: Ontogenic resistance versus genetic resistance
Authors: Calonnec Agnes , Jolivet Jerome , Ramaroson Marie‐Louisa , Dufour Marie‐Cecile , Corio‐Costet Marie‐France
Published: May 2021

The most sustainable management of resistant varieties involves understanding which defence mechanisms the plant uses according to its resistance genes and stage of development and how effective these mechanisms are. Three grapevine varieties were compared for their susceptibility versus resistance to powdery mildew: Vitis vinifera ‘Cabernet Sauvignon’ (CS) and two hybrids, ‘Artaban’ and ‘Prior’. Four different leaf ages were collected from 2‐year‐old grafted grapevines planted in pot or in vineyard, and several variables were assessed for each leaf: (a) morphological and physiological indicators, (b) pathogenicity traits: spore germination, infection efﬁciency, mycelial growth and sporulation, and (c) gene expression using a high‐throughput quantitative reverse transcription PCR method to inform about plant defence status and functioning of primary metabolism. A significant decrease in germination and sporulation with increasing leaf age were observed for the three varieties: Prior showed a susceptibility similar to that of CS, whereas Artaban was fully resistant with no sporulation. Genes highlighted as markers of the variety were involved in defence (VvPR3, VvPR4 overexpressed in Artaban, VvPR4bis, VvAlli2 in Prior) or in primary metabolism (repression of VvCitS in Artaban, VvCHI in Prior, overexpression of VvCAD2, VvGST3 in Prior). After inoculation, more defence genes, especially PR proteins, were overexpressed in the oldest leaves as potential components of ontogenic resistance. PR proteins accounted for 25% of total disease variation. Phenylpropanoid and ethylene pathways were leaf age‐dependent. The statistical method used highlighted the contributions of the genotypic expression involved in genetic (cultivar) and ontogenic (leaf age) resistances and of the metabolic pathways to the disease.
Rigorous justification of the Whitham modulation theory for equations of NLS type
Authors: Clarke W.A. , Marangell R.
Published: May 2021

We study the modulational stability of periodic travelling wave solutions to equations of nonlinear Schrödinger type. In particular, we prove that the characteristics of the quasi‐linear system of equations resulting from a slow modulation approximation satisfy the same equation, up to a change in variables, as the normal form of the linearized spectrum crossing the origin. This normal form is taken from Stability of Travelling wave solutions of Nonlinear Dispersive equations of NLS type, where Leisman et al. compute the spectrum of the linearized operator near the origin via an analysis of Jordan chains. We derive the modulation equations using Whitham's formal modulation theory, in particular the variational principle applied to an averaged Lagrangian. We use the genericity conditions assumed in the rigorous theory of Leismen et al.​to direct the homogenization of the modulation equations. As a result of the agreement between the equation for the characteristics and the normal form from the linear theory, we show that the hyperbolicity of the Whitham system is a necessary condition for modulational stability of the underlying wave.
On mixed problem of Chaplygin's hodograph equation in hyperbolic domain near the parabolic degenerate line
Authors: Xu Meng
Published: May 2021

The transonic flow problem is an important one in fluid dynamics or gas dynamics. Local solvability of the mixed problem of Chaplygin's hodograph equation in hyperbolic bounded domains near the degenerate line is considered by using abc method.
Biophysical and ultrasonographic changes in early patch/plaque stage of mycosis fungoides, compared with uninvolved skin
Authors: Yazdanparast Taraneh , Yazdani Kamran , Ahmad Nasrollahi Saman , Izadi Firouzabadi Leila , Humbert Philippe , Khatami Alireza , Kassir Martin , Firooz Alireza
Published: May 2021

Background

The goal of this study was evaluation of the skin biophysical properties in early patch/plaque stage of mycosis fungoides (MF) and its comparison with uninvolved skin in order to gain a better understanding of the pathogenesis of diseases.

Materials and Methods

The stratum corneum hydration, transepidermal water loss (TEWL), surface friction, pH, sebum, melanin, erythema, temperature, elasticity parameters (R0, R2, R5), thickness, and echo density of epidermis and dermis were measured on lesions of 21 patients and compared with controls (average measures of uninvolved perilesional and symmetrical skins) by paired sample t test.

Results

Stratum corneum hydration (P < 0.001) and echo density of dermis (P = 0.044) were significantly lower, whereas pH (P‐value = 0.007), erythema (P < 0.001), and melanin content (P = 0.007) were significantly higher in lesions. There was not any significant difference in TEWL, friction index, sebum, temperature, R0, R2, R5, thickness of epidermis and dermis, and echo density of epidermis between lesions and normal skin.

Conclusion

Parapsoriasis/MF lesions are specified by a set of certain changes in biophysical properties which are mainly correlated with histological changes. These sets of alterations may help in noninvasive, early diagnosis of parapsoriasis/MF.
Technique for analyzing the transfer of colored cosmetics onto face masks
Authors: Kim Suyeon , Lee Juseon , Park Minhye , Kim Hongbi , Kim Sungeun , Byun Ji Won , Hwang‐Bo Jeon , Park Keun Hyung
Published: May 2021

Background

With the rapid spread of COVID‐19, the makeup trend in the cosmetics market is changing as mask‐wearing has become a common practice. This study was conducted to establish an objective and reliable method for analyzing the transfer of colored cosmetics onto face masks.

Methods

A total of 24 women participated in this test. The participants were requested to wear Korean Filter 94 masks after having applied colored cosmetics on their faces and lips. VISIA‐CR was used to photograph the face, and a camera was used to photograph the mask, which had smeared the cosmetics. Each image was analyzed using the Image‐pro® 10 image analysis software.

Results

Immediately after applying the cosmetics, the intensity of the face decreased and the redness of the lips increased when compared with the results 30 minutes after washing the face. After wearing a mask, the intensity increased and the redness decreased when compared with immediately after applying the cosmetics. The area before and after the colored cosmetics smeared onto the mask was increased.

Conclusion

It is expected that this study could be used as a reference for further experiments on analysis of methods for preventing mask stains.
Phylogeny and temporal diversification of mosquitoes (Diptera: Culicidae) with an emphasis on the Neotropical fauna
Authors: Lorenz Camila , Alves João M.P. , Foster Peter G. , Suesdek Lincoln , Sallum Maria Anice M.
Published: May 2021

Understanding phylogenetic relationships within the family Culicidae informs mosquito evolution and may have public health implications as this family includes numerous species of medical and veterinary importance. We investigated the mitochondrial genomes of 102 mosquitoes, including six newly sequenced species, representing 21 genera with an emphasis on the Neotropical region. We estimated divergence times based on sequence data and three fossil calibration points, using Bayesian relaxed clock methods. Bayesian and maximum‐likelihood phylogenetic analyses based on the DNA sequences of 13 PCGs of the 102 species provided robust support for the monophyly of the subfamily Anophelinae and the tribes Aedini, Culicini, Mansoniini and Sabethini. Despite the current genera of Anophelinae being consistently recovered as monophyletic, relationships among them proved to be quite variable depending on the method used (concatenated or partitioned) and the number of taxa sampled. Molecular divergence time estimates revealed that the two mosquito subfamilies, Anophelinae and Culicinae, diverged in the early Jurassic (approximately 197.5 Mya). However, most major lineages of these groups arose after the Cretaceous, coincident with the emergence of angiosperms and the expansion of mammals and birds. The diversification and worldwide distribution of Culicidae may also be determined in part by geographic isolation as a result of continental drift during the Cretaceous.
RNA‐seq analysis of laser microdissected Arabidopsis thaliana leaf epidermis, mesophyll and vasculature defines tissue‐specific transcriptional responses to multiple stress treatments
Authors: Berkowitz Oliver , Xu Yue , Liew Lim Chee , Wang Yan , Zhu Yanqiao , Hurgobin Bhavna , Lewsey Mathew G. , Whelan James
Published: May 2021

SUMMARY

Acclimation of plants to adverse conditions requires the coordination of gene expression and signalling pathways between tissues and cell types. As the energy and carbon capturing organs, leaves are significantly affected by abiotic and biotic stresses. However, tissue‐ or cell type‐specific analyses of stress responses have focussed on the Arabidopsis root. Here, we comparatively explore the transcriptomes of three leaf tissues (epidermis, mesophyll, vasculature) after induction of diverse stress pathways by chemical stimuli (antimycin A, 3‐amino‐1,2,4‐triazole, methyl viologen, salicylic acid) and ultraviolet light in Arabidopsis using laser capture microdissection followed by RNA sequencing. Stimulation of stress pathways caused an overall reduction in the number of genes expressed in a tissue‐specific manner, though a small subset gained or changed their tissue specificity. We find no evidence of a common stress response, with only a few genes consistently responsive to two or more treatments in the analysed tissues. However, differentially expressed genes overlap between tissues for individual treatments. A focussed analysis provided evidence for an interaction of auxin and ethylene that mediates retrograde signalling during mitochondrial dysfunction specifically in the epidermis, and a gene regulatory network defined the hierarchy of interactions. Taken together, we have generated an extensive reference dataset that will be valuable for future experiments analysing transcriptional responses on a tissue or single‐cell level. Our results will enable the tailoring of the tissue‐specific engineering of stress‐tolerant plants.
A New Heat Source Model for Keyhole Mode Laser Welding
Authors: Lorin Samuel , Madrid Julia , Söderberg Rikard , Wärmefjord Kristina
Published: May 2021

Laser welding is a common technique for joining metals in many manufacturing industries. During welding, a weld gun traverses the interface of the parts to be joined causing them to melt, fuse, and solidify when the temperature decreases, thus joining the parts. Due to the heat input and the resulting melting and solidification, the parts deform causing residual distortion and residual stresses. To assure the geometrical and functional quality of the product, computational welding mechanics (CWM) is often employed in the design phase to predict the outcome of different design proposals. Furthermore, CWM can be used to design the welding process with the objective of assuring the quality of the weld. However, welding is a complex multiphysical process including the weld pool flow, microstructure dynamics, and structural mechanics. In a design process, it is typically not feasible, for example, to employ fluid simulation of the weld pool in order to predict deformation of a welded assembly, especially if a set of design proposals is under investigation. This is because of the high resolution needed for these fluid simulations in combination with challenges to couple fluid simulation with structural simulation. Instead, what is used is a heat source that emulates the heat input from the melt pool. An example of a heat source is the standard doubled ellipsoid. This heat source has been efficiently used for a large number of welding simulation. However, standard heat sources are typically not flexible enough to capture the fusion zone for deep keyhole mode laser welding. In this study, we presented a new heat source model for keyhole mode laser welding. In an industrial case study, a number of bead-on-plate welds have been employed to compare standard weld heat sources and develop the new heat source model. The proposed heat source is based on a combination of standard heat sources. From this study, it was concluded that the standard heat sources could not predict the observed melted zone for certain industrial application while the new heat source was able to do so. Therefore, the proposed heat source model can be employed to model keyhole mode laser welding, which enables welding simulation of a set of design proposals during the design process in a larger number of industrial cases.
New Correlations for Flow and Conjugate Heat Transfer With Surface Radiation Characteristics of a Real-Scale Infrared Suppression System With Conical Funnels
Authors: Mukherjee Arnab , Chandrakar Vikrant , Senapati Jnana Ranjan
Published: May 2021

The consistent and accurate prediction of fluid flow and heat transfer characteristics in an infrared suppression (IRS) device is challenging due to the complex nature of the flow features. The cool ambient air intake and subsequent mixing of hot exhaust gas from the engine in the cargo/naval ships are done inside the IRS system. The objective is to propose correlations for mass entrainment and outlet temperature for the IRS device with conical funnels. The mass intake rate and funnel exit temperature are determined by a set of relevant operating and geometric parameters, such as Reynolds number, nozzle exhaust temperature, the number of funnels, and funnel overlap. In this study, the funnel walls are conducting with finite wall thickness, and the surface radiation is taken into consideration. Numerical simulations are performed for the real-scale IRS unit by solving the mass, momentum, energy, and radiation equations in the computational domain surrounding the system. Nonlinear regression analysis of the data is carried out using the Levenberg and Marquest (L–M) method to achieve an empirical correlation of mass intake ratio and outlet temperature ratio. The proposed correlation for mass intake ratio is valid within ±6%, and that of outlet temperature is valid within ±5% of the numerical data. The valid ranges for correlations are 6×105≤ nozzle Reynolds number ≤3×106; 2 ≤ number of funnel ≤ 5; −0.325 ≤ funnel-overlapping height ≤ 0.25; and 1.33 ≤ nozzle exit temperature ≤ 2.
Microwave Versus Conventional Porcelain Firing: Greenware to Biscuit Crystallochemical Transformations
Authors: Santos T. , Gomes C. S. F. , Costa V. A. F. , Costa L. C.
Published: May 2021

This work reports and compares the structural crystallochemical transformations occurring during the microwave and conventional porcelain manufacture. Batches of greenware (just dried) porcelain pieces are microwave and electrically fired at increasing temperatures, from 420 °C up to 1100 °C. Crystallochemical transformations are identified by X-ray diffraction (XRD) analysis and compared the results from samples microwave and conventionally fired. Microwave fired samples show the full and rapid collapse of kaolinite structure for firing temperatures just above 500 °C, whereas the collapse of kaolinite structure of the electrically fired samples is progressive, from about 500 °C up to 950 °C. Muscovite structure totally collapses at about 950 °C for microwave fired greenware samples, whereas muscovite structure total collapse only occurs at about 1050 °C for electrically fired greenware samples. Microwave and electric firing lead to appreciable differences in the sanidine–orthoclase–microcline structural transformations. Mullite formation could be identified in the microwave fired samples at temperatures 50 °C lower than in the electrically fired ones, especially for the conventional firing temperatures above 1050 °C, the same temperature reported in the literature.
A General Expression for the Welding Tendon Force
Authors: Grams Mitchell R. , Mendez Patricio F.
Published: May 2021

This study presents a novel expression for the tendon force associated with residual stresses produced during welding of large, thin sections. A general engineering equation is presented as the combination of a closed-form expression, based on idealized treatment, and correction factors to account for the effects of temperature-dependent thermal and mechanical material properties. The closed-form expression corresponds to the assumption of constant material properties. A rigorous mathematical treatment is utilized to derive explicit, exact expressions for the temperature-dependent correction factors without the need for empirical correlations. The temperature-dependent behavior of materials is captured accurately using four dimensionless groups. The analysis was validated through numerical simulations with common structural grades of low-carbon steel, stainless steel, aluminum, and titanium. The idealized treatment resulted in predictions with a mean difference of 18%, which was reduced to 7% by incorporating the correction factors. The remaining error is a systematic overestimate, which can be attributed to compliance effects of the finite plate used in the simulations, and is the focus of ongoing research. The utility of applying the novel tendon force equation to problems in fabrication procedure design is demonstrated with an example predicting distortion during manufacturing of hollow structural sections.
Intuitive Physical Human–Robot Interaction Using an Underactuated Redundant Manipulator With Complete Spatial Rotational Capabilities
Authors: Audet Julien M. , Gosselin Clément
Published: May 2021

In this paper, the concept of underactuated redundancy is presented using a novel spatial two-degrees-of-freedom (2-DoF) gravity-balanced rotational manipulator, composed of movable counterweights. The proposed kinematic arrangement makes it possible to intuitively manipulate a payload undergoing 3-DoF spatial rotations by adding a third rotational axis oriented in the direction of gravity. The static equilibrium equations of the 2-DoF architecture are first described in order to provide the required configuration of the counterweights for a statically balanced mechanism. A method for calibrating the mechanism, which establishes the coefficients of the static equilibrium equations, is also presented. In order to both translate and rotate the payload during manipulation, the rotational manipulator is mounted on an existing translational manipulator. Experimental validations of both systems are presented to demonstrate the intuitive and responsive behavior of the manipulators during physical human–robot interactions.
The Hemolysis Effect of Rotary Cutting Thrombectomy Device: The CFD and Experimental Study
Authors: Gu Xuelian , Zhang Xiaoying , Qiu Xiaojian , Zheng Kang , Lu Licheng
Published: May 2021

Percutaneous mechanical thrombectomy (PMT) is an efficient way to treat the deep vein thrombosis (DVT). During the course of treatment, blood cell will be destroyed by the component of thrombectomy device, causing hemolysis. In this research, the computational fluid dynamics (CFD) methodology is used to investigate hemolysis effect of rotary cutting thrombectomy device. And a prototype of rotary cutting thrombectomy device is made to carry out two corresponding experiments to verify the simulation results. CFD results indicate that the hemolysis rate increases significantly with the rise of rotation speed of cutting component. The experimental results are in good consistence with the CFD results, and shows that the longer the working time, the higher the hemolysis rate. Thus a rotation speed between 5,000 rpm and 10,000 rpm can be considered reasonable. The results can be served as a helpful guidance for the design of such thrombectomy devices.
Design of Novel Baby Personal Protective Equipment: A Portable IOT-Based Baby Protective Tent
Authors: Liao Yu-Chi , Bu Hsing-Yun , Lee Pei-Jung , Lin Yu-Sheng , Weng Chen-Hsun
Published: May 2021

Due to the threat of COVID-19 pandemic, personal protection equipment (PPE) has raised lots of attentions to protect people from infection. This unprecedented virus can be spread through airborne, respiratory droplets and social contact. Although there are some devices and PPEs for people who are conscious and able to obey the social distance policy, to protect infants is still challenging. Baby is one of the vulnerable groups to the disease but there is no appropriate PPE when baby needs to be exposed to irresistible events like visiting a hospital, receiving vaccination or being accompanied by parents who come home from work). In this study, a concept of smart baby protective tent is developed. The simple hardware offers a quick assembly using PVC pipes, 3D-printed joints and a transparent cover sheet to create an independent and safe space from direct and indirect infection through breathing or saliva. With two additional parts, the smart baby protective tent can thereby provide clear air circulation and modern care. A fan system equipped with a clamp for a disposable medical-certified mask is applied to supply clean and circulated air for the babies. Functional sensors are attached to detect essential signals like body temperature, environment temperature, humidity, vibration, brightness, sound, CO2, and PM 2.5. These received signals are processed via a micro-controller and can be uploaded to personal social media in order to increase caregivers’ awareness of the babies’ situation inside the tent.
The Design and Use of a Minimally-Invasive, Expandable Retractor for Deep-Seated Brain Lesions
Authors: Yoo Sun Jay , Mou Jody , Elizebath Reena , Sivakumar Ananyaa , DeBrabander Rene , Shifman Mark , Tu Kevin , Ishida Wataru , Fouda Mohammed , Manbachi Amir , Cohen Alan R.
Published: May 2021

Access to deep-seated brain lesions (e.g., tumors, aneurysms, hematomas, and other malformations) is challenging due to the potential for retraction-induced injury. Traditionally, neurosurgeons use dissection and blade retractors to push apart tissue to visualize and operate on target lesions. These blades apply focal pressure onto the brain, resulting in ischemia, edema, and parenchymal trauma, leading to complications in up to 29% of cases. Tubular retractors were introduced to distribute forces radially and have led to improved safety and clinical outcomes. However, reports indicate that tubular retractors still led to complications in up to 9.1% of cases. Other concerns include significant pressure in the direction of insertion and the displacement of anatomic landmarks leading to inaccurate stereotaxis.

We present a novel, minimally-invasive brain retractor that utilizes an expandable soft balloon to further reduce retraction-induced injury and increase stereotactic accuracy with a minimal port of entry. The device consists of a balloon catheter system, a clear sheath, and integration with neuronavigation stylets. This approach can reduce the rate of iatrogenic injury and improve clinical outcomes for brain lesion operations. Furthermore, we illustrate the efficacy of this device in use compared to those of conventional tubular and blade retractors in a pig cadaver.
Imaging of Focused Ultrasound-Induced Shear Waves to Probe Mechanical Anisotropy of Tissue
Authors: Guertler Charlotte A , Okamoto Ruth J , Garbow Joel R , Chen Hong , Bayly Philip V
Published: May 2021

It is important to understand mechanical anisotropy in fibrous soft tissues because of the relationship of anisotropy to tissue function, and because anisotropy may change due to injury and disease. We have developed a method to noninvasively investigate anisotropy, based on MR imaging of harmonic ultrasound-induced motion (MR-HUM), using focused ultrasound (FUS) and magnetic resonance elastography (MRE). MR-HUM produces symmetric, radial waves inside a tissue, which enables a simple assessment of anisotropy using features of the resulting shear wave fields. This method was applied to characterize ex vivo muscle tissue, which is known to exhibit mechanical anisotropy. Finite element (FE) simulations of the experiment were performed to illustrate and validate the approach. Anisotropy was characterized by ratios of apparent shear moduli and strain components in different directions.
Automated Device for Public Elevator Control Panel UVC Sanitization
Authors: Hu Jia , O’Brien Jacob , Joshi Amey S. , Navabi Zahra S. , Alegria Andrew D. , Kodandaramaiah Suhasa B.
Published: May 2021

In response to the COVID-19 pandemic, studies have shown that frequently-touched surfaces that are contaminated with SARS-CoV-2 can pose a risk to public health and safety. Considering elevators as a high-risk environment for the spread of COVID-19 and other infectious diseases via surface transmission, common methods of manually applying liquid-form disinfectants are impractical for sanitizing the elevator panel after each use. Therefore, an automated UVC light surface sanitization device with integrated sensing components to avoid UVC light-human interaction and perform frequent sanitization was developed. Algorithmically, the system uses a motion sensor, an inertial measurement unit, and a door sensor to determine when the elevator is empty, stationary, and shut. Once these conditions are met, the UVC lamp is enabled to safely sanitize the elevator control panel. The device’s UVC irradiation capabilities were tested by applying UVC light to a mock control panel. A minimum power density of 0.31 mW/cm² was detected, which can deactivate SARS-CoV-2. The sensing and control system was tested in an elevator and it was demonstrated to be able to detect operating conditions and activate the UVC light at appropriate instances. Our device operates using inexpensive hardware and it can be easily integrated into existing elevator infrastructures.
Design of a Multi-Degree-of-Freedom Traction and Stabilization Device for Open Reduction and Internal Fixation of Distal Radius Fractures
Authors: Oeding J. , Bockman S. , Chiu H. , Hua C. , Connor J. , Slocum A.
Published: May 2021

Open reduction and internal fixation (ORIF) is a surgical procedure performed with the objectives of restoring normal alignment and providing stability to broken bone fragments after a fracture. This procedure is increasingly used to treat fractures of the distal end of the radius. Reduction of the fracture into correct alignment is often achieved by the surgeon pulling and manipulating the hand while looking at real-time x-rays, and frequently requires large forces to distract impacted fragments from proximal bone. This can make the task of simultaneously aligning the fracture fragments and placing hardware to secure fragments into the correct position particularly challenging for surgeons. This study presents the design and preliminary testing of a multi-degree-of-freedom (DOF) device capable of performing both distraction and reduction of fractured bone fragments using a traction splint mechanism with locking joints that results in significantly reduced effort and greater accuracy in performing ORIF procedures on distal radius fractures. Quantitative force testing found an 80% reduction in the maximum force required to create needed traction, while qualitative tests with a hand surgeon found the device’s ability to reduce and stabilize bone fragments while hardware is secured to be more intuitive and less obstructive than existing techniques.
3D Shape Estimation of an Active Needle Inside Tissue Using 2D Ultrasound Images
Authors: Konh Bardia , Batsaikhan Zolboo , Padasdao Blayton
Published: May 2021

This work presents a method to estimate 3D shape of an active needle inside tissue using 2D transverse ultrasound images. The shape of the needle provides a valuable feedback information for precise control and guidance of the needle inside tissue toward target. We used a series of image processing techniques to identify the needle’s cross section in the ultrasound images. Using this method, we estimated the 3D shape of a tendon-driven active needle, when bent inside a transparent phantom tissue using a robotic needle insertion system. The estimated shape of the needle was then compared with true shape of the needle captured by two cameras. At least three ultrasound images were required to estimate the needle shape with a second order polynomial function. We found an average error of 0.54mm and a maximum error of 1.00mm in shape estimation compared to the true shape of the needle captured by the cameras for an insertion depth of 70mm.
A Qualitative Comparison of the Covex Respirator with Face Shield Versus the N95 Respirator
Authors: Mimmack Reid , Germo Elijah , Augustine Garrett , Belani Kumar
Published: May 2021

In March 2020, the World Health Organization declared the novel coronavirus (COVID-19) outbreak a worldwide pandemic. The pandemic led to concerns of shortages regarding healthcare-related resources, including personal protective equipment (PPE), ventilators, and more. The uniquely designed COVEX respirator with face shield was engineered and manufactured by Augustine Surgical, Inc. to combat the PPE shortage. The novel COVEX mask is an “all-in-one” face shield and filter with a Viral Filtration Efficiency (VFE) greater than 99%. A standard respirator qualitative fit test was completed on the COVEX respirator as well as the current medical standard 3M N95 respirator. Fit test studies comparing the two masks yielded similar outcomes. The COVEX respirator had a qualitative fit test pass rate of 96.6% and the 3M N95 respirator had a pass rate of 93.3% (n=30). Participants also reported other variables comparing the comfort and fit of each mask, which is described further in the discussion. The COVEX respirator with face shield passed a standardized qualitative fit test at a rate similar to the current medical standard N95 respirator. Our results suggest that the COVEX mask may be a viable PPE option in the future.
Design of a Soft, Self-Uncoiling Stent for Extended Retention of Drug Delivery in the Small Intestine
Authors: Sarker Sunandita , Jones Ryan , Chow Gabriel , Terry Benjamin
Published: May 2021

Despite being the preferred route of drug administration, the oral formulation of biological drugs is limited due to its intrinsic instability, low permeability, and physical, chemical and immunological barriers. Various innovative swallowable technologies such as drug-loaded, dissolvable microneedles, mucoadhesive patches, and various microdevices present unique drug-carrying capabilities. The current work presents a novel soft stent platform that can facilitate contact between the small intestine tissue and drug carriers to enhance drug absorption and increase residence time. This study aims to prove the concept of this novel platform and determine if the soft stent will retain orally to the ileocecal valve longer than a capsule-shaped bolus. Benchtop studies on an intestinal simulator showed successful retention of the soft stent compared to a control capsule. In vivo studies in pig models also showed that the soft stent was retained longer than the control capsule. Overall, this study shows promise that this novel platform could be used for oral drug delivery of biologics.
Application of a Viscous Liquid as an Aerosol for Post-Operative Adhesion Prevention: First Engineering Steps Towards Nozzle Design
Authors: Smith P. Alex , Keane Timothy J. , Serpelloni Stefano , Ramon Stephen G. , Taraballi Francesca
Published: May 2021

Postoperative adhesions are scar tissue that form between internal organs after surgery, leading to devastating life-long complications. Current adhesion barriers used clinically are solid sheets which can only be applied in open surgeries through large incisions. We have developed a material which can be applied as a liquid in minimally invasive surgeries which transitions into a solid thin film barrier upon contact with warm tissue. However, to be effective, it must be sprayed, and spraying a viscous liquid consistently is challenging. We proposed using a gas dispersant to facilitate aerosolization. In this study, we compared a commercially available nozzle without gas dispersant to a custom 3D printed nozzle with gas dispersant. For comparison, we measured both spray pattern and stiffness of the resulting gel. We found that when sprayed with gas dispersant, the spray pattern covered a larger area, and the resulting gel was stiffer than when sprayed without gas dispersant.
Modeling Reality: Revisiting Calvert’s Fitness Simulation
Authors: Hartzler Aniya , Qian Alice , Rupert Daniella , Sethi Maia , VanBibber Helina , Bova Taylor , Seshadri Dhruv , Drummond Colin
Published: May 2021

Wearable sensors have gained mainstream acceptance for health and fitness monitoring despite the absence of clinically validated analytic models for clinical decision support. Individual sensors measuring, say, EKG signal and heart rate can provide insight on cardiovascular response, but a more complete picture of health and fitness requires a more complete portfolio of sensors and data. This paper outlines the research underway to revisit and reconfigure the 1976 Calvert systems model of the effect of training on physical performance. Specifically, we use wearable sensor data from clinical trials to supplement a hybrid model created by nesting Perl’s Performance-Potential model within Calvert’s transfer function approach to system simulation. Contemporary simulation tools combined with wearables clinical trial data is the foundation for a more agile platform for simulation of fitness and exploration of causality between training and physical performance. This platform offers the opportunity to strategically integrate data from various wearable sensors in a fashion enabling improved support for post-injury and return to sport decision-making.
Natural Language Processing Based Machine Learning Model Using Cardiac MRI Reports to Identify Hypertrophic Cardiomyopathy Patients
Authors: Sundaram Divaakar Siva Baala , Arunachalam Shivaram P. , Damani Devanshi N. , Farahani Nasibeh Z. , Enayati Moein , Pasupathy Kalyan S. , Arruda-Olson Adelaide M.
Published: May 2021

Hypertrophic Cardiomyopathy (HCM) is the most common genetic heart disease in the US and is known to cause sudden death (SCD) in young adults. While significant advancements have been made in HCM diagnosis and management, there is a need to identify HCM cases from electronic health record (EHR) data to develop automated tools based on natural language processing guided machine learning (ML) models for accurate HCM case identification to improve management and reduce adverse outcomes of HCM patients.

Cardiac Magnetic Resonance (CMR) Imaging, plays a significant role in HCM diagnosis and risk stratification. CMR reports, generated by clinician annotation, offer rich data in the form of cardiac measurements as well as narratives describing interpretation and phenotypic description. The purpose of this study is to develop an NLP-based interpretable model utilizing impressions extracted from CMR reports to automatically identify HCM patients. CMR reports of patients with suspected HCM diagnosis between the years 1995 to 2019 were used in this study. Patients were classified into three categories of yes HCM, no HCM and, possible HCM. A random forest (RF) model was developed to predict the performance of both CMR measurements and impression features to identify HCM patients. The RF model yielded an accuracy of 86% (608 features) and 85% (30 features). These results offer promise for accurate identification of HCM patients using CMR reports from EHR for efficient clinical management transforming health care delivery for these patients.
Application of Machine Learning for Detection of Hypertrophic Cardiomyopathy Patients from Echocardiogram Measurements
Authors: Farahani Nasibeh Zanjirani , Enayati Moein , Sundaram Divaakar Siva Baala , Damani Devanshi , Kaggal Vinod C. , Zacher April L. , Geske Jeffrey B. , Kane Garvan , Arunachalam Shivaram Poigai , Pasupathy Kalyan , Arruda-Olson Adelaide M.
Published: May 2021

Hypertrophic cardiomyopathy (HCM) is a heritable, phenotypically diverse, and often asymptomatic heart muscle disease which is a major cause of sudden cardiac death (SCD) in young adults. The gold-standard for the diagnosis of HCM is echocardiography (echo), which is an ultrasound-based cardiac imaging modality. Across all sites of the Mayo Clinic enterprise, echo images and measurement data are reviewed, interpreted, and reported via the Echo Information Management System (EIMS). The objective of this paper is to develop a machine learning model for the identification of HCM from cardiac measurements obtained by the echo. We developed a novel machine learning model on patient demographic information and echo measurements that were retrieved from the EIMS digital data registry and selected by cardiologists.

Random forest (RF) was utilized to investigate the predictive performance of these features on the identification of HCM patients. The HCM cohort consists of 3,548 patients with at least one HCM diagnostic billing code (ICD-9 or ICD-10), from 2014 to 2019. The class labels “HCM yes” and “HCM no” were assigned by manual review of medical records as well as the outcomes of the gold standard imaging tests for HCM diagnosis. The developed model performed well in finding HCM patients with an accuracy of 95%, recall of 99%, and precision of 97%. The F1 score was 98 %, while 4% of patients were misclassified. This model will be translated into clinical practice for a clinical decision support system in EIMS to assist providers in the accurate diagnosis of HCM from echo data automatically while ensuring high-quality echo interpretation.
Measuring Line Pressure in Convection-Enhanced Delivery Infusions
Authors: Mehta Jason N. , Morales Brianna E. , Rylander Christopher G.
Published: May 2021

Convection-Enhanced Delivery (CED) is an investigative treatment for brain tumors. Reflux has been shown to be a key issue in the success of CED treatments. Minimal research has been conducted to determine the onset of reflux. Furthermore, the ability to identify reflux allows for corrective action to be taken before the consequences of reflux renders the treatment unsuccessful. Reflux could be quickly identified by changes in pressure measured in the catheter. In this study we examine the difficulties associated with measuring inline pressure. Results indicate the measured inline pressure will change depending on catheter length and orientation. Therefore, relative changes in pressure coupled with early treatment imaging could be utilized to determine the success of CED treatment.
Crisis Ventilator: A 3D Printed Option for Pressure Controlled Ventilation
Authors: Brito Alex , Fontaine Evan , El Haddi S. James , Chi MD FACS Albert
Published: May 2021

During the Coronavirus-19, or COVID-19, pandemic there was an early shortage of available ventilators. Domestic production was limited by dependence on overseas sources of raw materials despite partnering with automotive manufacturers. Our group has developed a 3D printed alternative called the CRISIS ventilator. Its design is similar to existing resuscitator devices on the market and uses a modified Pressure-Control ventilation. Here we compare the performance of the device on a simulated ARDS lung and handling of different clinical scenarios included tension pneumothorax and bronchospasm.
Impact of chemical bonding difference of ALD Mo on SiO2 and Al2O3 on the effective work function of the two gate stacks
Authors: Zoubenko Ekaterina , Iacopetti Sara , Weinfeld Kamira , Kauffmann Yaron , Van Cleemput Patrick , Eizenberg Moshe
Published: May 2021

This study investigates molybdenum deposited by atomic layer deposition (ALD) as a potential gate metallization for flash memory devices. Polycrystalline (110)-oriented, with low-resistivity (∼16 μΩ cm) ALD Mo films were deposited on SiO2 and Al2O3 using hydrogen reduction of Mo-oxychloride precursor. On SiO2, an effective work function (EWF) of 4.75 ± 0.1 eV was obtained for as-deposited samples, and its value increased up to 4.9 ± 0.05 eV upon annealing at 600 °C, whereas on Al2O3, a stable EWF value of 5.05 ± 0.05 eV was observed. The EWF variation is correlated with changes in the composition and chemical bonding at the metal/dielectric interface. The latter were investigated by energy dispersive x-ray spectroscopy and electron energy loss spectroscopy performed using scanning transmission electron microscopy and x-ray photoelectron spectroscopy. This analysis revealed that the presence of Mo oxide at the Al2O3/Mo interface stabilizes the EWF, and the EWF increase on SiO2 is attributed to Si enrichment at the SiO2/Mo interface upon annealing. A theoretical model is suggested to explain the chemical bonding difference on SiO2 and Al2O3, based on the Mo-precursor reactions with the surface groups of the dielectric. This study emphasizes the importance of the precursor/substrate reactions in determining the compositional and, therefore, electrical properties of the metal/dielectric interface, and demonstrates that ALD Mo deposited directly on SiO2 and Al2O3 is a promising candidate for gate metallization of flash devices due to its high EWF.
Effects of thickness and interlayer on optical properties of AlN films at room and high temperature
Authors: Liu Yao , Yang Zhaolun , Long Xianjian , Zhang Xiong , Yan Minxin , Huang Dan , Ferguson Ian T. , Feng Zhe Chuan
Published: May 2021

This paper investigates the systematic influence of thickness (136–412 nm) and temperature (300–860 K) on the refractive index and the band-edge of aluminum nitride (AlN) films. The combination of x-ray diffraction, spectroscopic ellipsometry (SE), and transmittance measurements at 300 K shows that the increase of epilayer thickness or the introduction of an AlN interlayer can improve the crystal quality. This is observed as an enlargement of the grain size, a reduction of the Urbach binding energy, and strain with a corresponding increase in the refractive index and bandgap. Moreover, the expected reduction in the bandgap and the increase of the refractive index are observed at elevated temperatures by SE. The temperature dependence of the refractive index at 632.8 nm and the bandgap were well understood and modeled using a quadratic nonlinear equation and the Bose–Einstein equation, respectively. This high-temperature phenomenological and quantitative analysis suggests that the reduction of the bandgap with temperature is more significant in thinner or noninterlayer films than expected due to the corresponding stronger electron–phonon interactions involved with larger Urbach binding energies. The thickest AlN film in this work (with an epilayer thickness of 412.9 nm and an interlayer thickness of 20.69 nm) has the smallest strength of the average electron–phonon coupling (407 meV) in the temperature range 300–860 K. On the other hand, the temperature-dependent variation of the refractive index in the transparent region is more rapid as the film thickness decreases owing to the high correlation between temperature-dependent bandgap and refractive index. These observations are critical when designing AlN-based device structures that can operate well above room temperature.