Clinical and laboratory characteristics of patients hospitalized with severe COVID-19 in New Orleans, August 2020 to September 2021.

Louisiana experienced high morbidity and mortality from COVID-19. To assess possible explanatory factors, we conducted a cohort study (ClinSeqSer) of patients hospitalized with COVID-19 in New Orleans during August 2020-September 2021. Following enrollment, we reviewed medical charts, and performed SARS-CoV-2 RT-PCR testing on nasal and saliva specimens. We used multivariable logistic regression to assess associations between patient characteristics and severe illness, defined as ≥ 6 L/min oxygen or intubation. Among 456 patients, median age was 56 years, 277 (60.5%) were Black non-Hispanic, 436 (95.2%) had underlying health conditions, and 358 were unvaccinated (92.0% of 389 verified). Overall, 187 patients (40.1%) had severe illness; 60 (13.1%) died during admission. In multivariable models, severe illness was associated with age ≥ 65 years (OR 2.08, 95% CI 1.22-3.56), hospitalization > 5 days after illness onset (OR 1.49, 95% CI 1.01-2.21), and SARS CoV-2 cycle threshold (Ct) result of < 32 in saliva (OR 4.79, 95% CI 1.22-18.77). Among patients who were predominantly Black non-Hispanic, unvaccinated and with underlying health conditions, approximately 1 in 3 patients had severe COVID-19. Older age and delayed time to admission might have contributed to high case-severity. An association between case-severity and low Ct value in saliva warrants further investigation.

Impact of Race, gait speed and arch height on plantar loading.

Diabetes is a leading cause for death in the United States, with African Americans (AA) being twice as likely to die from diabetes than White Americans (WA). AA are twice as likely to experience diabetes-related foot amputation due to foot ulcers, which are most often caused by high plantar pressure. While it is known that arch height, sex, family history of diabetes, Body Mass Index (BMI), age, and gait speed can impact plantar loading, there is a need to test the hypothesis that race in combination with the previously mentioned variables are significant predictors of plantar loading. To answer this question, plantar loading data was collected from 107 participants using an EMED pressure-measurement system (Novel Electronics, Inc, St Paul, MN, USA). Each participant walked barefoot at a self-selected walking pace ten times. Contact area, maximum force, and were force-time integral collected for each step on the pressure plate. A multiple linear regression was used to test if race, age, Arch Height Index (AHI), gait speed, sex assigned at birth, family history of diabetes, and BMI significantly predicted plantar loading. Race, age, AHI, gait speed, sex, and BMI were considered significant predictor variables for plantar loading. Most importantly, race was a significant predictor of maximum force in the hallux (ß = 6.46, p < 0.001), rearfoot (ß = -6.36, p < 0.001), and lateral midfoot (ß = -2.72, p < 0.001), and the force-time integral in the hallux (ß = 2.37, p < 0.001), rearfoot (ß = -2.14, p < 0.001), and lateral midfoot (ß = -0.65, p < 0.001). These findings could help with understanding why AA are more likely to develop diabetic foot ulcers than WA.

Empowering Black Scientists in STEM: Early Success of the Black Biomechanists Association.

Black individuals are underrepresented in science, technology, engineering, and mathematics (STEM) fields. In 2016, Black students earned 9% of science and 4% of engineering bachelor's degrees compared to a total of 56% of science and engineering bachelor's degrees earned by White students. Even with similar entering rates, Black students leave STEM majors at 1.4 times the rate of White students. These data reflect the manifestation of diversity, equity, and inclusion (DEI) barriers faced by Black students and scientists to successfully navigate higher education and pursue careers in STEM fields. There remains a critical need to develop better ways to recruit, retain, train, and graduate Black students in STEM, especially within predominantly White institutions. Biomechanics is a growing interdisciplinary and translational STEM field where DEI barriers persist. Thus, the Black Biomechanists Association (BBA) was founded in 2020 with intentions to reduce these barriers and give much needed support to Black students and biomechanists in STEM spaces. The organization's mission is to uplift and enrich Black biomechanists in their academic and professional careers. Our objectives to achieve this mission provide a supportive environment and resources to address the challenges, needs, and interests of Black biomechanists, as well as aid in the biomechanics community's efforts to achieve DEI. In two short years, BBA has developed a needs-based mentoring program, hosted professional development and culturally-competent mentoring workshops, and produced communications to educate the biomechanics community and broader audience on culturally-relevant topics that impact Black biomechanists. The purpose of this article is to share the work and impact of BBA to date.

Development of a finite element-based model for the thermal assessment of transtibial prosthetic liners.

BACKGROUND: Thermal discomfort because of elevated residual limb skin temperatures and/or perspiration within the prosthetic socket is frequently reported among people with amputation. OBJECTIVE: To evaluate the impact of the thermal conductivity characteristics of prosthetic liners on transtibial prosthesis heat dissipation, following postactivity rest. STUDY DESIGN: Time-dependent heat transfer study in solids using finite element analysis. METHODS: A three-dimensional model of the transtibial residual limb was developed by simplifying the geometry to tapered, layered cylinders. Four prosthetic socket liners of varying thermal conductivities were then added to the exterior, and the final surface temperatures of the skin layer were analyzed. RESULTS: Warmer temperatures were observed near regions with greater muscle volume; cooler temperatures were observed at the distal end of the simplified model. The final residual limb skin temperatures for each prosthetic liner were found to be significantly different from one another. Overall, the average final surface temperatures of the skin layer at the end of postactivity rest was 3.85°C ± 0.12°C greater than the initial surface temperatures of skin layer. CONCLUSIONS: None of the prosthetic liners made a significant reduction in residual limb skin temperatures after activity. The results indicate that the focus should be on other material properties of the prosthetic liners or active cooling systems.

Type 1 Diabetes incidence among youth in Utah: A geographical analysis.

Type 1 Diabetes (T1D) poses an increasing threat to public health, as incidence rates continue to rise globally. However, the etiology of T1D is still poorly understood, especially from the perspective of geography. The objective of this research is to examine the incidence of T1D among youth and to identify high-risk clusters and their association with socio-demographic and geographic variables. The study area was the entire state of Utah and included youth with T1D from birth to 19 years of age from 1998 to 2015 (n = 4161). Spatial clustering was measured both globally and locally using the Moran's I statistic and spatial scan statistic. Ordinary least squares (OLS) regression was used to measure the association of high-risk clusters with certain risk factors at the Census Block Group (CBG) level. The mean age at diagnosis was 9.3 years old. The mean incidence rate was 25.67 per 100,000 person-years (95% CI, 24.57-26.75). The incidence rate increased by 14%, from 23.94 per100,000 person-years in 1998 to 27.98 per 100,000 person-years in 2015, with an annual increase of 0.80%. The results of the spatial scan statistic found 42 high-risk clusters throughout the state. OLS regression analysis found a significant association with median household income, population density, and latitude. This study provides evidence that incidence rates of T1D are increasing annually in the state of Utah and that significant geographic high-risk clusters are associated with socio-demographic and geographic factors.

The Structural Effects of Diabetes on Soft Tissues: A Systematic Review.

Hyperglycemia, which is associated with diabetes, increases the production of advanced glycation end products. Advanced glycation end products lead to the structural degradation of soft tissues. The structural degradation of diabetic soft tissues has been investigated in humans, rodents, and canines. Therefore, the objective of this review is to unify the various contributions to diabetes research through the mechanical properties and geometric characteristics of soft tissues. A systematic review was performed and identified the effects of diabetes on mechanical and geometric properties of soft tissues via experimental testing or in vivo - driven finite element analysis. The literature concludes that diabetes contributes to major structural changes in soft tissues but does not cause the same structural changes in all soft tissues (e.g., diabetic tendons are weaker and diabetic plantar tissues are tougher). Diabetes stiffens and toughens soft tissues, thus altering viscoelastic behavior (e.g., poor strain and stress response). However, diabetes management routines can prevent or minimize the effects of diabetes on the mechanical and geometric properties of soft tissues. Unification of the structural effects of diabetes on soft tissues will contribute to the pathophysiology of diabetes.

Supersoft Top Squarks.

In a supersymmetric theory, the IR contributions to the Higgs mass are calculable below the mediation scale Λ_{UV} in terms of the IR field content and parameters. However, logarithmic sensitivity to physics at Λ_{UV} remains. In this Letter, we present a first example of a framework, dictated by symmetries, to supersoften these logarithms from the matter sector. The result is a model with finite, IR-calculable corrections to the Higgs mass. This requires the introduction of new fields-the "lumberjacks"-whose role is to screen the UV-sensitive logs. These models have considerably reduced fine-tuning, by more than an order of magnitude for high-scale supersymmetry. This impacts interpretations of the natural parameter space, suggesting it may be premature to declare a naturalness crisis for high-scale supersymmetry.

Impact of screw thread shape on stress transfer in bone: a finite element study.

Gradual screw loosening is a well-known failure mechanism in internal fixation. Loosening is primarily due to progressive bone loss caused by stress shielding, a phenomenon in which a medical device absorbs a disproportionate amount of load within the screw-bone construct. The proximity of elastic moduli of magnesium and bone presents the potential for alleviating screw loosening by allowing optimum stress to be transferred between screw and bone, and in turn, supporting bone remodeling around the screw. In this study, the effect of thread profile on stress transfer in a magnesium fixation was simulated using a 2-D finite element model. Modified stress parameters from a previous study were used to estimate stress transfer across three thread profiles. Results showed highest stress transfer in trapezoidal-shaped magnesium screw thread. In accordance, this study corroborates the potential for magnesium as an ultimate screw material to eliminate progressive screw loosening.

Design of a new magnesium-based anterior cruciate ligament interference screw using finite element analysis.

BACKGROUND/OBJECTIVE: In anterior cruciate ligament â€‹reconstruction, a tendon graft, anchored by interference screws (IFSs), is frequently used as a replacement for the damaged ligament. Generally, IFSs are classified as being either metallic or polymeric. Metallic screws have sharp threads that lacerate the graft, preventing solid fixation. These constructs are difficult to image â€‹and can limit bone--screw integration because of the higher stiffness of the screw. Polymeric materials are often a better match to bone's material properties, but lack the strength needed to hold grafts in place. Magnesium (Mg) is a material of great promise for orthopaedic applications. Mg has mechanical properties similar to bone, ability to be seen on magnetic resonance imagings, and promotes bone healing. However, questions still remain regarding the strength of Mg-based screws. Previous ex vivo â€‹animal experiments found stripping of the screw drive when the full torque was applied to Mg screws during surgery, preventing full insertion and poor graft fixation. The similar design of the Mg screw led to questions regarding the relationship between material properties and design, and the ultimate impact on mechanical behaviour. Thus, the objective of this study was to analyze the stresses in the screw head, a key factor in the stripping mechanism of IFS, then use that information to improve screw design, for this material. METHODS: Using finite element analysis, a comparison study of six drive designs (hexagonal, quadrangle, torx, trigonal, trilobe, and turbine) was performed. This was followed by a parametric analysis to determine appropriate drive depth and drive width. RESULTS: It was observed that with a typical torque (2 â€‹Nm) used for screw insertion during anterior cruciate ligament reconstruction, the maximum von Mises and shear stress values were concentrated in the corners or turns of the drive, which could lead to stripping if the values were greater than the yield stress of Mg (193 â€‹MPa). With a four-time â€‹increase in drive depth to be fully driven and a 30% greater drive width, these maximum stress values were significantly decreased by more than 75%. CONCLUSION: It was concluded that improving the design of a Mg-based screw may increase surgical success rates, by decreasing device failure at insertion. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The results of this work have the potential to improve designs of degradable IFSs, allowing for greater torque to be applied and thus greater screw fixation between host bone and the graft. Such a fixation will allow greater integration, better patient healing, and ultimately improved patient outcomes.

Long-lived particles at the energy frontier: the MATHUSLA physics case.

We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of standard model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the [Formula: see text]m scale up to the Big Bang Nucleosynthesis limit of [Formula: see text] m. Neutral LLPs with lifetimes above [Formula: see text]100 m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging backgrounds, triggers, and small acceptances. MATHUSLA is a proposal for a minimally instrumented, large-volume surface detector near ATLAS or CMS. It would search for neutral LLPs produced in HL-LHC collisions by reconstructing displaced vertices (DVs) in a low-background environment, extending the sensitivity of the main detectors by orders of magnitude in the long-lifetime regime. We study the LLP physics opportunities afforded by a MATHUSLA-like detector at the HL-LHC, assuming backgrounds can be rejected as expected. We develop a model-independent approach to describe the sensitivity of MATHUSLA to BSM LLP signals, and compare it to DV and missing energy searches at ATLAS or CMS. We then explore the BSM motivations for LLPs in considerable detail, presenting a large number of new sensitivity studies. While our discussion is especially oriented towards the long-lifetime regime at MATHUSLA, this survey underlines the importance of a varied LLP search program at the LHC in general. By synthesizing these results into a general discussion of the top-down and bottom-up motivations for LLP searches, it is our aim to demonstrate the exceptional strength and breadth of the physics case for the construction of the MATHUSLA detector.

Prognostic significance, angiographic characteristics and impact of antithrombotic and anticoagulant therapy on outcomes in high versus low grade coronary artery ectasia: A long-term follow-up study.

OBJECTIVES: To assess the prognostic significance of high vs. low grade coronary artery ectasia (CAE) and the impact of antithrombotic or anticoagulant therapy on adverse cardiac outcomes. BACKGROUND: There is paucity of knowledge on the impact of angiographic characteristics in CAE or that of antithrombotic or anticoagulant therapy on outcomes. METHODS AND RESULTS: In this retrospective study, we reviewed angiograms and medical records of all cases of confirmed CAE (2001-2011). Extent of CAE was categorized using the Markis classification. Types 1 and 2 were categorized as high-grade and types 3 and 4 as low-grade CAE. Angiographic flow was recorded as normal or sluggish (

A facility to search for hidden particles at the CERN SPS: the SHiP physics case.

This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, [Formula: see text] and to search for weakly-interacting sub-GeV dark matter candidates. We discuss the evidence for physics beyond the standard model and describe interactions between new particles and four different portals-scalars, vectors, fermions or axion-like particles. We discuss motivations for different models, manifesting themselves via these interactions, and how they can be probed with the SHiP experiment and present several case studies. The prospects to search for relatively light SUSY and composite particles at SHiP are also discussed. We demonstrate that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the standard model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation.

Rapidly Progressing Chagas Cardiomyopathy.

Chagas disease, caused by the parasite Trypanosoma cruzi, can cause a potentially life-threatening cardiomyopathy in approximately 10-40% of afflicted individuals. The decline in cardiac function characteristically progresses over the course of many years. We report a case of Chagas disease in which the patient experienced an atypical rapid deterioration to severe cardiomyopathy over the course of 16 months. This case argues the need for increased routine surveillance for patients with confirmed T. cruzi infection, who are determined to be at high-risk for worsening cardiomyopathy.

Goldstone Gauginos.

Models of supersymmetry with Dirac gauginos provide an attractive scenario for physics beyond the standard model. The "supersoft" radiative corrections and suppressed supersymmetry production at colliders provide for more natural theories and an understanding of why no new states have been seen. Unfortunately, these models are handicapped by a tachyon which is naturally present in existing models of Dirac gauginos. We argue that this tachyon is absent, with the phenomenological successes of the model preserved, if the right-handed gaugino is a (pseudo-)Goldstone field of a spontaneously broken anomalous flavor symmetry.

Revolutionizing orthopaedic biomaterials: The potential of biodegradable and bioresorbable magnesium-based materials for functional tissue engineering.

In recent years, there has been a surge of interest in magnesium (Mg) and its alloys as biomaterials for orthopaedic applications, as they possess desirable mechanical properties, good biocompatibility, and biodegradability. Also shown to be osteoinductive, Mg-based materials could be particularly advantageous in functional tissue engineering to improve healing and serve as scaffolds for delivery of drugs, cells, and cytokines. In this paper, we will present two examples of Mg-based orthopaedic devices: an interference screw to accelerate ACL graft healing and a ring to aid in the healing of an injured ACL. In vitro tests using a robotic/UFS testing system showed that both devices could restore function of the goat stifle joint. Under a 67-N anterior tibial load, both the ACL graft fixed with the Mg-based interference screw and the Mg-based ring-repaired ACL could restore anterior tibial translation (ATT) to within 2mm and 5mm, respectively, of the intact joint at 30°, 60°, and 90° of flexion. In-situ forces in the replacement graft and Mg-based ring-repaired ACL were also similar to those of the intact ACL. Further, early in vivo data using the Mg-based interference screw showed that after 12 weeks, it was non-toxic and the joint stability and graft function reached similar levels as published data. Following these positive results, we will move forward in incorporating bioactive molecules and ECM bioscaffolds to these Mg-based biomaterials to test their potential for functional tissue engineering of musculoskeletal and other tissues.

New probe of naturalness.

Any new scalar fields that perturbatively solve the hierarchy problem by stabilizing the Higgs boson mass also generate new contributions to the Higgs boson field-strength renormalization, irrespective of their gauge representation. These new contributions are physical, and in explicit models their magnitude can be inferred from the requirement of quadratic divergence cancellation; hence, they are directly related to the resolution of the hierarchy problem. Upon canonically normalizing the Higgs field, these new contributions lead to modifications of Higgs couplings that are typically great enough that the hierarchy problem and the concept of electroweak naturalness can be probed thoroughly within a precision Higgs boson program. Specifically, at a lepton collider this can be achieved through precision measurements of the Higgs boson associated production cross section. This would lead to indirect constraints on perturbative solutions to the hierarchy problem in the broadest sense, even if the relevant new fields are gauge singlets.

Complications of axial lumbar interbody fusion.

OBJECT: Axial lumbar interbody fusion (AxiaLIF) is a novel minimally invasive approach for fusion of L4-5 and L5-S1. This technique uses the presacral space for percutaneous access to the anterior sacrum. The AxiaLIF procedure has the potential to decrease patient recovery time, length of hospital stay, and overall occurrence of surgical complications. It can be used alone or in combination with minimally invasive or traditional open fusion procedures. The purpose of this study was to evaluate complications of the AxiaLIF procedure at the authors' institutions. METHODS: Patients who underwent AxiaLIF surgery between October 2005 and June 2009 at the authors' institutions were identified. The authors retrospectively reviewed these patients' charts, including operative reports and postoperative medical records, to determine what complications were encountered. RESULTS: A total of 68 patients underwent AxiaLIF surgery, with an average follow-up time of 34 months. Sixteen patients (23.5%) experienced a total of 18 complications (26.5%); this group included 8 men and 8 women (mean age 52.1 years). These complications included pseudarthrosis (8.8%), superficial infection (5.9%), sacral fracture (2.9%), pelvic hematoma (2.9%), failure of wound closure (1.5%), transient nerve root irritation (1.5%), and rectal perforation (2.9%). CONCLUSIONS: The complication rate associated with AxiaLIF in the present study was relatively low (26.5%). The most common complications were superficial infection and pseudarthrosis. There were 2 cases of rectal perforation associated with AxiaLIF; one case was found intraoperatively and the other presented 4 days postoperatively. Both patients underwent emergency repair by a general surgeon and had no long-term sequelae as a result of the rectal injuries. It is important for surgeons to be aware of the potential for these complications. Many of these complications can probably be avoided with proper patient selection and operative planning. Preoperative MR imaging, a detailed patient physical examination and history, full bowel preparation, and the use of live fluoroscopy can all help to prevent complications with AxiaLIF surgery.

Moment arms of the ankle throughout the range of motion in three planes.

BACKGROUND: The moment, a force applied at a distance, is responsible for movement and balance. A key component of the moment is the moment arm. The moment arms of nine muscles surrounding the ankle complex during motion in three planes, were studied. MATERIALS AND METHODS: Five cadaveric feet were mounted in a testing device that created moments in the sagittal, coronal and transverse planes. Axial and tendon loads were applied as the foot was passively moved in these planes. Tendon excursions and bone kinematics were monitored. The moment arm was calculated using the tendon excursion method and averaged across all specimens. RESULTS: The largest average moment arm during plantarflexion/dorsiflexion, was the Achilles (mean, 53.1; SD, 5.1 mm). During internal/external rotation the largest moment arm was the peroneus brevis (mean, 20.5; SD, 6.4 mm). During inversion/eversion, the largest moment arm was the peroneus longus (31 mm; SD, 2.3 mm). CONCLUSION: This study quantified the functional moment arms of nine tendons of the ankle/foot. The involvement of multiple tendons in multiple planes of motion should be considered in computational models and when deciding treatments. CLINICAL RELEVANCE: The correlation between moment arms and muscle function has significant effects on treatment efficacy. Information on the balance of moments around the ankle will assist in achieving optimal biomechanical behavior following operative treatments.

Evaluation of muscles affected by myositis using magnetic resonance elastography.

INTRODUCTION: Idiopathic inflammatory myopathies (IIMs, or myositis) represent a group of autoimmune diseases that result in decreased muscle strength and/or endurance. Non-invasive tools to assess muscle may improve our understanding of the clinical and functional consequences of myopathies and their response to treatment. In this study we examine magnetic resonance elastography (MRE), a non-invasive technique that assesses the shear modulus (stiffness) of muscle, in IIM subjects. METHODS: Nine subjects with active myositis completed the MRE protocol. Participants lay in a positioning device, and scans of the vastus medialis (VM) were taken in the relaxed state and at two contraction levels. Manual inversion was used to estimate the stiffness. RESULTS: A significant reduction in muscle stiffness was seen in myositis subjects compared with healthy controls during the "relaxed" condition. DISCUSSION: The use of non-invasive technologies such as MRE may provide greater understanding of the pathophysiology of IIM and improve assessment of treatment efficacy.