Femoral Neck Anteversion: Which Distal Femur Landmark Matters?

Background: Femoral neck anteversion has traditionally been measured by the angle between the distal femur posterior condylar axis (PCA) and a line drawn through the center of the femoral head and neck. While less common, the transepicondylar axis (TEA) has also been used to reference femoral neck anteversion. The purpose of this study was to compare femoral neck version of the PCA vs the TEA using computerized tomography (CT). Methods: A total of 1507 femoral CTs were included. Precise bony landmarks were established: lateral epicondyle, medial epicondyle, posteromedial condyle, posterolateral condyle, center of the femoral neck, and center of the femoral head. Femoral version was calculated between the head and neck axis and either the PCA or TEA. Differences between sex and ethnicity were evaluated. Results: The mean femoral anteversion was 12.7° ± 9.1° based on the PCA and 11.5° ± 7.9° based on the TEA (mean difference 1.2° ± 1.9°, P < .001). Males were less anteverted than females (9.8° ± 7.6° vs 13.5° ± 7.8°, P < .001). African Americans had less anteversion than other groups (8.1° ± 9.2° vs 11.5° ± 7.8°, P = .04), while Asians were more anteverted than other groups (12.1° ± 9.0° vs 11.2° ± 7.3°, P = .04). These values were referenced on the TEA. Conclusions: In this series of over 1500 femoral CT scans, the mean difference between anteversion measurements referencing the PCA and TEA was 1.2°. Native femoral version varied widely between gender and ethnic groups. Extreme femoral version, defined as <0° or >30°, was present in 11.8% of patients referencing the PCA.

Leadership perspectives on osteopathic medical school applicants to pathology residency training.

The number of graduating allopathic (MD) medical students matching into pathology has declined in recent years, while the number of osteopathic (DO) medical students has increased modestly, given the rapid expansion of osteopathic medical schools. Nonscholarly publications and materials on the internet often perpetuate negative perceptions of osteopathic physicians. Anecdotally, perspectives exist that some pathology residency programs are not DO-friendly; however, the reasons and how widespread an effect this might be are unclear. Our survey queried pathology chairs and residency program directors about their perceptions of osteopathic applicants and their knowledge of osteopathic medical school/training in general. This study utilized two similar, parallel surveys of pathology chairs and residency program directors with general questions structured around the perceptions and knowledge of both allopathic and osteopathic physicians, their medical training, and the consideration of osteopathic applicants to pathology residency. Pathology residency leaders acknowledge some negative perceptions of osteopathic physicians in the medical profession, the news, and social media. They also have some knowledge and perception gaps regarding osteopathic training and applicants, although experience with training osteopathic physicians as residents has been equivalent to that with allopathic physicians, and consideration appears to be fairly equal for osteopathic applicants. Even though negative perceptions of osteopathic physicians persist in news and social media, our surveys demonstrate that the leadership of pathology residency programs does not hold the same degree of bias and that DOs perform well in allopathic pathology residency programs without evidence of inferior outcomes.

How to Estimate Femoral Stem Anteversion During Direct Anterior Approach Total Hip Arthroplasty.

Background: There are various traditional landmarks used to estimate the femoral component version, yet none are widely accepted by direct anterior surgeons. The purpose of this study was to compare bony landmarks easily accessible to direct anterior surgeons and to estimate which one provides the best estimate of femoral component anteversion. Methods: A computed tomography database was used to identify 736 left entire-femur computed tomography scans. Seven visible anatomic landmarks were identified using a computer model in which a 45° virtual neck resection was made at 10 mm above the lesser trochanter. Thirteen axes, to reference the femoral stem position, were created between the 7 landmarks. Means and standard deviations (SDs) of angles between each axis and the transepicondylar axis (TEA) were compared for their precision. Results: The traditional lesser trochanter predicted anteversion from the TEA was 34.1° (SD 9.7°). Predicted anteversion from the TEA was 3.3° (SD 8.1°) when aligned from the center of the canal to the middle of the medial calcar; 14.0° (SD 8.1°) from the center of the canal to the anterior 1/3 of the medial calcar; and 24.8° (SD 8.5°) from the center of the canal to the most anterior point on the medial calcar. Conclusions: Compared to the lesser trochanter, 7 axes were more precise (lower SD) when predicting the version. Estimating the femoral component position, via simulated data, using 3 points along the medial calcar is a relatively precise and easily accessible tool for surgeons.

A modified Delphi consensus statement on patellar instability: part I.

Aims: The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. Methods: A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous. Results: Of 27 questions and statements on patellar instability, three achieved unanimous consensus, 14 achieved strong consensus, five achieved consensus, and five did not achieve consensus. Conclusion: The statements that reached unanimous consensus were that an assessment of physeal status is critical for paediatric patients with patellar instability. There was also unanimous consensus on early mobilization and resistance training following nonoperative management once there is no apprehension. The statements that did not achieve consensus were on the importance of immobilization of the knee, the use of orthobiologics in nonoperative management, the indications for MPFC repair, and whether a vastus medialis oblique advancement should be performed.

A modified Delphi consensus statement on patellar instability: part II.

Aims: The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. Methods: This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous. Results: Of 41 questions and statements on patellar instability, none achieved unanimous consensus, 19 achieved strong consensus, 15 achieved consensus, and seven did not achieve consensus. Conclusion: Most statements reached some degree of consensus, without any achieving unanimous consensus. There was no consensus on the use of anchors in MPFL reconstruction, and the order of fixation of the graft (patella first versus femur first). There was also no consensus on the indications for trochleoplasty or its effect on the viability of the cartilage after elevation of the osteochondral flap. There was also no consensus on postoperative immobilization or weightbearing, or whether paediatric patients should avoid an early return to sport.

Healthcare staff mental health trajectories during the COVID-19 pandemic: findings from the COVID-19 Staff Wellbeing Survey.

BACKGROUND: Cross-sectional studies have shown that the COVID-19 pandemic has had a significant impact on the mental health of healthcare staff. However, it is less well understood how working over the long term in successive COVID-19 waves affects staff well-being. AIMS: To identify subpopulations within the health and social care staff workforce with differentiated trajectories of mental health symptoms during phases of the COVID-19 pandemic. METHOD: The COVID-19 Staff Wellbeing Survey assessed health and social care staff well-being within an area of the UK at four time points, separated by 3-month intervals, spanning November 2020 to August 2021. RESULTS: Growth mixture models were performed on the depression, anxiety and post-traumatic stress disorder longitudinal data. Two class solutions provided the best fit for all models. The vast majority of the workforce were best represented by the low-symptom class trajectory, where by symptoms were consistently below the clinical cut-off for moderate-to-severe symptoms. A sizable minority (13-16%) were categorised as being in the high-symptom class, a group who had symptom levels in the moderate-to-severe range throughout the peaks and troughs of the pandemic. In the depression, anxiety and post-traumatic stress disorder models, the high-symptom class perceived communication from their organisation to be less effective than the low-symptom class. CONCLUSIONS: This research identified a group of health service staff who reported persistently high mental health symptoms during the pandemic. This group of staff may well have particular needs in terms of the provision of well-being support services.

Ungulate spatiotemporal responses to contrasting predation risk from wolves and snow leopards.

Spatial responses to risk from multiple predators can precipitate emergent consequences for prey (i.e. multiple-predator effects, MPEs) and mediate indirect interactions between predators. How prey navigate risk from multiple predators may therefore have important ramifications for understanding the propagation of predation-risk effects (PREs) through ecosystems. The interaction of predator and prey traits has emerged as a potentially key driver of antipredator behaviour but remains underexplored in large vertebrate systems, particularly where sympatric prey share multiple predators. We sought to better generalize our understanding of how predators influence their ecosystems by considering how multiple sources of contingency drive prey distribution in a multi-predator-multi-prey system. Specifically, we explored how two sympatric ungulates with different escape tactics-vertically agile, scrambling ibex Capra sibirica and sprinting argali Ovis ammon-responded to predation risk from shared predators with contrasting hunting modes-cursorial wolves Canis lupus and vertical-ambushing, stalking snow leopards Panthera uncia. Contrasting risk posed by the two predators presented prey with clear trade-offs. Ibex selected for greater exposure to chronic long-term risk from snow leopards, and argali for wolves, in a nearly symmetrical manner that was predictable based on the compatibility of their respective traits. Yet, acute short-term risk from the same predator upended these long-term strategies, increasing each ungulates' exposure to risk from the alternate predator in a manner consistent with a scenario in which conflicting antipredator behaviours precipitate risk-enhancing MPEs and mediate predator facilitation. By contrast, reactive responses to wolves led ibex to reduce their exposure to risk from both predators-a risk-reducing MPE. Evidence of a similar reactive risk-reducing effect for argali vis-à-vis snow leopards was lacking. Our results suggest that prey spatial responses and any resulting MPEs and prey-mediated interactions between predators are contingent on the interplay of hunting mode and escape tactics. Further investigation of interactions among various drivers of contingency in PREs will contribute to a more comprehensive understanding and improved forecasting of the ecological effects of predators.

The trochlear sulcus of the native knee is consistently orientated close to the sagittal plane despite variation in distal condylar anatomy.

PURPOSE: The aim of this study was to describe the native trochlear orientation of non-arthritic knees in three planes and to quantify the relationship between trochlear and distal condylar anatomy across race and sex. METHODS: Computed tomography scans of 1578 femora were included in this study. The mediolateral position of the trochlear sulcus, the distal trochlear sulcus angle (DTSA) the medial sulcus angle (MSA) and the lateral sulcus angle (LSA) as well as the mechanical lateral distal femoral angle (mLDFA) were measured relative to a standard reference coordinate system. Multiple linear regression analyses were performed to account for potential confounding variables. RESULTS: The mediolateral position of the trochlear sulcus had minimal mean deviation of the sagittal femoral plane. The mean DTSA was 86.1° (SD 2.2°). Multilinear regression analysis found mLDFA, sex, and age all influence DTSA (p < 0.05), with mLDFA having by far the greatest influence (r2 = 0.55). The medial facet of the trochlear sulcus was found to be flat proximally and more prominent distally. The lateral facet was relatively uniform throughout the arc. CONCLUSION: In non-arthritic knees, due to a strong positive correlation between the DTSA and the mLDFA, the trochlear sulcus is consistently orientated in the sagittal femoral plane regardless of distal condylar anatomy. Minor deviations from the sagittal plane occur in a lateral direction in the middle part and in a medial direction at the proximal and distal part of the trochlea. These findings have relevance regarding the biomimetic design of total knee implants.

Hemisilicone Elastomers That Are Recyclable to the Monomer.

Methyl-, vinyl-, and hydride-terminated polymers of the heterocyclic monomer, 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane (c-M2E) were prepared by sulfuric acid-catalyzed, ring-opening equilibration with the end-capping agents hexamethyldisiloxane (MM), divinyltetramethyldisiloxane (MVMV), and tetramethyldisiloxane (MHMH), respectively. The molecular weights of the polymers were controlled by adjusting the ratio of monomer to end-capping agent. All of these polymers are oils and exhibit molecular weight-dependent viscosities that are qualitatively similar to those of polydimethylsiloxane (PDMS)-based analogs prepared by the same reaction using octamethylcyclotetrasiloxane (D4) instead of c-M2E. Vinyl end-capped polymers with a range of molecular weights were cross-linked by platinum-catalyzed hydrosilylation with tetramethylcyclotetrasiloxane (DH4) to prepare a series of transparent solid elastomers with moduli that increase with decreasing molecular weight. These studies suggest that reactive polymers prepared from c-M2E may be useful resins in two-part curable elastomer formulations. Several experiments, as well as the over 60-year-old initial synthesis of this polymer, suggest that the recyclability of these resins and elastomers may be practical.

Alterations in Protein Translation and Carboxylic Acid Catabolic Processes in Diabetic Kidney Disease.

Diabetic kidney disease (DKD) remains the leading cause of end-stage kidney disease despite decades of study. Alterations in the glomerulus and kidney tubules both contribute to the pathogenesis of DKD although the majority of investigative efforts have focused on the glomerulus. We sought to examine the differential expression signature of human DKD in the glomerulus and proximal tubule and corroborate our findings in the db/db mouse model of diabetes. A transcriptogram network analysis of RNAseq data from laser microdissected (LMD) human glomerulus and proximal tubule of DKD and reference nephrectomy samples revealed enriched pathways including rhodopsin-like receptors, olfactory signaling, and ribosome (protein translation) in the proximal tubule of human DKD biopsy samples. The translation pathway was also enriched in the glomerulus. Increased translation in diabetic kidneys was validated using polyribosomal profiling in the db/db mouse model of diabetes. Using single nuclear RNA sequencing (snRNAseq) of kidneys from db/db mice, we prioritized additional pathways identified in human DKD. The top overlapping pathway identified in the murine snRNAseq proximal tubule clusters and the human LMD proximal tubule compartment was carboxylic acid catabolism. Using ultra-performance liquid chromatography-mass spectrometry, the fatty acid catabolism pathway was also found to be dysregulated in the db/db mouse model. The Acetyl-CoA metabolite was down-regulated in db/db mice, aligning with the human differential expression of the genes ACOX1 and ACACB. In summary, our findings demonstrate that proximal tubular alterations in protein translation and carboxylic acid catabolism are key features in both human and murine DKD.

A poly(ethylene glycol) three-dimensional bone marrow hydrogel.

Three-dimensional (3D) hydrogels made from synthetic polymers have emerged as in vitro cell culture platforms capable of representing the extracellular geometry, modulus, and water content of tissues in a tunable fashion. Hydrogels made from these otherwise non-bioactive polymers can be decorated with short peptides derived from proteins naturally found in tissues to support cell viability and direct phenotype. We identified two key limitations that limit the ability of this class of materials to recapitulate real tissue. First, these environments typically display between 1 and 3 bioactive peptides, which vastly underrepresents the diversity of proteins found in the extracellular matrix (ECM) of real tissues. Second, peptides chosen are ubiquitous in ECM and not derived from proteins found in specific tissues, per se. To overcome this critical limitation in hydrogel design and functionality, we developed an approach to incorporate the complex and specific protein signature of bone marrow into a poly (ethylene glycol) (PEG) hydrogel. This bone marrow hydrogel mimics the elasticity of marrow and has 20 bone marrow-specific and cell-instructive peptides. We propose this tissue-centric approach as the next generation of 3D hydrogel design for applications in tissue engineering and beyond.

COVID-19 Staff Wellbeing Survey: longitudinal survey of psychological well-being among health and social care staff in Northern Ireland during the COVID-19 pandemic.

BACKGROUND: Throughout the coronavirus disease 2019 (COVID-19) pandemic, health and social care workers have faced unprecedented professional demands, all of which are likely to have placed considerable strain on their psychological well-being. AIMS: To measure the national prevalence of mental health symptoms within healthcare staff, and identify individual and organisational predictors of well-being. METHOD: The COVID-19 Staff Wellbeing Survey is a longitudinal online survey of psychological well-being among health and social care staff in Northern Ireland. The survey included four time points separated by 3-month intervals; time 1 (November 2020; n = 3834) and time 2 (February 2021; n = 2898) results are presented here. At time 2, 84% of respondents had received at least one dose of a COVID-19 vaccine. The survey included four validated psychological well-being questionnaires (depression, anxiety, post-traumatic stress and insomnia), as well as demographic and organisational measures. RESULTS: At time 1 and 2, a high proportion of staff reported moderate-to-severe symptoms of depression (30-36%), anxiety (26-27%), post-traumatic stress (30-32%) and insomnia (27-28%); overall, significance tests and effect size data suggested psychological well-being was generally stable between November 2020 and February 2021 for health and social care staff. Multiple linear regression models indicated that perceptions of less effective communication within their organisation predicted greater levels of anxiety, depression, post-traumatic stress and insomnia. CONCLUSIONS: This study highlights the need to offer psychological support to all health and social care staff, and to communicate with staff regularly, frequently and clearly regarding COVID-19 to help protect staff psychological well-being.

Range of Motion to Impingement Curves Create a New Patient-Specific Impingement-Free Zone for Acetabular Cup Placement.

INTRODUCTION: The acetabular "safe zone" has recently been questioned as a reliable reference for predicting total hip arthroplasty impingement and instability as many dislocations occur within the described parameters. Recently, an improved understanding of spino-pelvic mechanics has provided surgeons useful information to both identify those at a higher risk of dislocation and, in some cases, allows altering component positioning to accommodate the patient's individual "functional" range of motion. The purpose of this study was to create a new patient-specific impingement-free zone by considering range of motion (ROM) to prosthetic impingement for both high flexion and extension poses, thus demarcating a zone that avoids both anterior and posterior impingement, thereby creating an objective approach to identifying a patient's ideal functional safe zone. MATERIALS AND METHODS: A validated hip ROM three-dimensional simulator was utilized to create ROM-to-impingement curves for both high flexion as well as pivot and turn poses. The user imported a computerized tomography (CT) with a supine pelvic tilt (PT) value of zero and implant models (tapered wedge stem, 132° neck angle, 15° stem version, 36mm femoral head). Femur-to-pelvis relative motions were determined for three upright seated poses (femur flexed at 90° and 40° internal rotation, with 0°, 10°, and 20° posterior PT), one chair rise pose (femur flexed at 90° and 0° internal rotation, with the pelvis flexed anteriorly until the pelvis made contact with the femur), and three standing pivot and turn poses (femur set at 5° extension, and 35° external rotation, with 5° posterior PT, 0°, and 5° anterior PT). ROM-to-impingement curves for cup inclination versus anteversion were graphed and compared against the Lewinnek safe zone. RESULTS: The ROM-to-impingement curves provide an objective assessment of potential impingement sites as they relate to femoral rotation and pelvic tilt. The area between the stand and sit curves is the impingement-free area. A sitting erect pose with a simulated stiff spine (0° PT) yielded less impingement-free combinations of cup inclination and version than poses with greater than 0° posterior pelvic tilt. CONCLUSION: The results demonstrate that the acetabular target zone has a relatively small margin for error between the sitting and standing ROM curves to impingement. Importantly, anterior and posterior pelvic tilt can markedly increase the risk of impingement, potentially leading to posterior or anterior dislocations, respectively. This study highlights the importance of correctly identifying the patient-specific functional range of motion to execute optimal component positioning.

The orchestrated cellular and molecular responses of the kidney to endotoxin define a precise sepsis timeline.

Sepsis is a dynamic state that progresses at variable rates and has life-threatening consequences. Staging patients along the sepsis timeline requires a thorough knowledge of the evolution of cellular and molecular events at the tissue level. Here, we investigated the kidney, an organ central to the pathophysiology of sepsis. Single-cell RNA-sequencing in a murine endotoxemia model revealed the involvement of various cell populations to be temporally organized and highly orchestrated. Endothelial and stromal cells were the first responders. At later time points, epithelial cells upregulated immune-related pathways while concomitantly downregulating physiological functions such as solute homeostasis. Sixteen hours after endotoxin, there was global cell-cell communication failure and organ shutdown. Despite this apparent organ paralysis, upstream regulatory analysis showed significant activity in pathways involved in healing and recovery. This rigorous spatial and temporal definition of murine endotoxemia will uncover precise biomarkers and targets that can help stage and treat human sepsis.

Rediscovering Silicones: The Anomalous Water Permeability of "Hydrophobic" PDMS Suggests Nanostructure and Applications in Water Purification and Anti-Icing.

Cross-linked polydimethylsiloxane (PDMS) is simultaneously water-repellent and highly permeable to water vapor. Unfilled and silica-free cross-linked PDMS films of variable thickness (8-160 µm) are prepared and their water vapor transmission rates and permeability values are determined. Vapor transmission rate increases as membrane thickness decreased from 160 to 15 µm, but does not increase further when the film thickness is decreased to 8 µm. Rate-limiting sorption is implicated as the cause of this effect and substantiated by a surface modification to enhance adsorption rate. Water vapor does not macroscopically condense on films thin enough to operate in this kinetic regime, and vapor transmission rates as high as 60% of the transmission rates through air are measured. A mechanism for water permeation is offered based on those proposed for nanoscopically confined water in carbon nanotubes and aquaporins.

Multiple factors influence local perceptions of snow leopards and Himalayan wolves in the central Himalayas, Nepal.

An understanding of local perceptions of carnivores is important for conservation and management planning. In the central Himalayas, Nepal, we interviewed 428 individuals from 85 settlements using a semi-structured questionnaire to quantitatively assess local perceptions and tolerance of snow leopards and wolves. We used generalized linear mixed effect models to assess influential factors, and found that tolerance of snow leopards was much higher than of wolves. Interestingly, having experienced livestock losses had a minor impact on perceptions of the carnivores. Occupation of the respondents had a strong effect on perceptions of snow leopards but not of wolves. Literacy and age had weak impacts on snow leopard perceptions, but the interaction among these terms showed a marked effect, that is, being illiterate had a more marked negative impact among older respondents. Among the various factors affecting perceptions of wolves, numbers of livestock owned and gender were the most important predictors. People with larger livestock herds were more negative towards wolves. In terms of gender, males were more positive to wolves than females, but no such pattern was observed for snow leopards. People's negative perceptions towards wolves were also related to the remoteness of the villages. Factors affecting people's perceptions could not be generalized for the two species, and thus need to be addressed separately. We suggest future conservation projects and programs should prioritize remote settlements.

A Different Silica Surface: Radical Oxidation of Poly(methylsilsesquioxane) Thin Films and Particles (Tospearl).

Surfaces that exhibit the reactivity of silica toward surface modification (silanol condensation) were prepared by treating thin films and particles of poly(methylsilsesquioxane) with aqueous potassium persulfate at elevated temperature. Parallel experiments were carried out using a highly cross-linked poly(dimethylsiloxane). Advancing (θA) and receding (θR) water contact angles for all of these oxidized surfaces were θA/θR = ∼10/∼0°, and these low values remain unchanged for months. Reactions of these silica-like surfaces with a range of functional silane reagents indicate that the surface silanol concentration is sufficient to prepare covalently attached monolayers of similar surface density to those prepared using silicon wafers as substrates.

Children Devise and Selectively Use Tools to Offload Cognition.

From maps sketched in sand to supercomputing software, humans ubiquitously enhance cognitive performance by creating and using artifacts that bear mental load [1-5]. This extension of information processing into the environment has taken center stage in debates about the nature of cognition in humans and other animals [6-9]. How does the human mind acquire such strategies? In two experiments, we investigated the developmental origins of cognitive offloading in 150 children aged between 4 and 11 years. We created a memory task in which children were required to recall the location of hidden targets. In one experiment, participants were provided with a pre-specified cognitive offloading opportunity: an option to mark the target locations with tokens during the hiding period. Even 4-year-old children quickly adopted this external strategy and, in line with a metacognitive account, children across ages offloaded more often when the task was more difficult. In a second experiment, we provided children with the means to devise their own cognitive offloading strategy. Very few younger children spontaneously devised a solution, but by ages 10 and 11, nearly all did so. In a follow-up test phase, a simple prompt greatly increased the rate at which the younger children devised an offloading strategy. These findings suggest that sensitivity to the difficulties of thinking arises early in development and improves throughout the early school years, with children learning to modify the world around them to compensate for their cognitive limits.

Identifying Injury Patterns Associated With Physical Elder Abuse: Analysis of Legally Adjudicated Cases.

STUDY OBJECTIVE: Elder abuse is common and has serious health consequences but is underrecognized by health care providers. An important reason for this is difficulty in distinguishing between elder abuse and unintentional trauma. Our goal was to identify injury patterns associated with physical elder abuse in comparison with those of patients presenting to the emergency department (ED) with unintentional falls. METHODS: We partnered with a large, urban district attorney's office and examined medical, police, and legal records from successfully prosecuted cases of physical abuse of victims aged 60 years or older from 2001 to 2014. RESULTS: We prospectively enrolled patients who presented to a large, urban, academic ED after an unintentional fall. We matched 78 cases of elder abuse with visible injuries to 78 unintentional falls. Physical abuse victims were significantly more likely than unintentional fallers to have bruising (78% versus 54%) and injuries on the maxillofacial, dental, and neck area (67% versus 28%). Abuse victims were less likely to have fractures (8% versus 22%) or lower extremity injuries (9% versus 41%). Abuse victims were more likely to have maxillofacial, dental, or neck injuries combined with no upper and lower extremity injuries (50% versus 8%). Examining precise injury locations yielded additional differences, with physical elder abuse victims more likely to have injuries to the left cheek or zygoma (22% versus 3%) or on the neck (15% versus 0%) or ear (6% versus 0%). CONCLUSION: Specific, clinically identifiable differences may exist between unintentional injuries and those from physical elder abuse. This includes specific injury patterns that infrequently occur unintentionally.

Sessile Liquid Features as Molds for Silicone Elastomers.

Liquid applied to a chemically patterned (wetting/nonwetting, lyophilic/lyophobic) substrate forms a 3-dimensional contoured surface, the shape of which depends on the volume of liquid applied and the shape of the three-phase contact lines of air (or other phase in contact), liquid, and the wetted pattern. The resulting binary contoured interface with air, which consists of flat unwetted regions of the substrate and the mean curvature liquid-vapor interfaces of the sessile structures, can be used as a mold for imprinting solid polymers by curing liquid resins in contact. The success, flexibility with regard to shape, and reproducibility of this molding process depend on numerous issues. These include the substrate surface chemistry, the liquid application method, properties of the liquid (vapor pressure, surface tension, viscosity, and permeability in the resin), the contact angles of the liquid on the patterned substrate, and the resin curing chemistry and conditions. We investigate the room temperature platinum(0)-catalyzed curing of the most commonly studied commercial silicone elastomer, Sylgard 184, using molds composed of sessile drops of liquids on circular wetting features (bare silicon wafer) patterned on covalently attached fluoroalkylsilyl monolayers. Liquids reported are water, glycerol, an ethylene glycol oligomer, and an ionic liquid. The vapor pressure of water and its permeability in dimethyl silicone were important (and problematic) issues that could be controlled by adjusting humidity. The ionic liquid N-ethyl-N'-methylimidazolium methanesulfonate poisoned/inhibited the curing chemistry and affected silicone cross-link density and the resulting feature shape, but its lack of vapor pressure was useful in studying flow coating as a scalable liquid application method. The ethylene glycol oligomer exhibited compatibility with (and diffusion into) the silicone. Glycerol proved to be the most well-behaved and controllable liquid studied and was used to demonstrate that condensation/evaporation can be used to adjust feature shape.