Systemic Hypoxemia Induces Cardiomyocyte Hypertrophy and Right Ventricular Specific Induction of Proliferation.

BACKGROUND: A recent study suggests that systemic hypoxemia in adult male mice can induce cardiac myocytes to proliferate. The goal of the present experiments was to confirm these results, provide new insights on the mechanisms that induce adult cardiomyocyte cell cycle reentry, and to determine if hypoxemia also induces cardiomyocyte proliferation in female mice. METHODS: EdU-containing mini pumps were implanted in 3-month-old, male and female C57BL/6 mice. Mice were placed in a hypoxia chamber, and the oxygen was lowered by 1% every day for 14 days to reach 7% oxygen. The animals remained in 7% oxygen for 2 weeks before terminal studies. Myocyte proliferation was also studied with a mosaic analysis with double markers mouse model. RESULTS: Hypoxia induced cardiac hypertrophy in both left ventricular (LV) and right ventricular (RV) myocytes, with LV myocytes lengthening and RV myocytes widening and lengthening. Hypoxia induced an increase (0.01±0.01% in normoxia to 0.11±0.09% in hypoxia) in the number of EdU+ RV cardiomyocytes, with no effect on LV myocytes in male C57BL/6 mice. Similar results were observed in female mice. Furthermore, in mosaic analysis with double markers mice, hypoxia induced a significant increase in RV myocyte proliferation (0.03±0.03% in normoxia to 0.32±0.15% in hypoxia of RFP+ myocytes), with no significant change in LV myocyte proliferation. RNA sequencing showed upregulation of mitotic cell cycle genes and a downregulation of Cullin genes, which promote the G1 to S phase transition in hypoxic mice. There was significant proliferation of nonmyocytes and mild cardiac fibrosis in hypoxic mice that did not disrupt cardiac function. Male and female mice exhibited similar gene expression following hypoxia. CONCLUSIONS: Systemic hypoxia induces a global hypertrophic stress response that was associated with increased RV proliferation, and while LV myocytes did not show increased proliferation, our results minimally confirm previous reports that hypoxia can induce cardiomyocyte cell cycle activity in vivo.

Improving explanation of motor disability with diffusion-based graph metrics at onset of the first demyelinating event.

BACKGROUND: Conventional magnetic resonance imaging (MRI) does not account for all disability in multiple sclerosis. OBJECTIVE: The objective was to assess the ability of graph metrics from diffusion-based structural connectomes to explain motor function beyond conventional MRI in early demyelinating clinically isolated syndrome (CIS). METHODS: A total of 73 people with CIS underwent conventional MRI, diffusion-weighted imaging and clinical assessment within 3 months from onset. A total of 28 healthy controls underwent MRI. Structural connectomes were produced. Differences between patients and controls were explored; clinical associations were assessed in patients. Linear regression models were compared to establish relevance of graph metrics over conventional MRI. RESULTS: Local efficiency (p = 0.045), clustering (p = 0.034) and transitivity (p = 0.036) were reduced in patients. Higher assortativity was associated with higher Expanded Disability Status Scale (EDSS) (ß = 74.9, p = 0.026) scores. Faster timed 25-foot walk (T25FW) was associated with higher assortativity (ß = 5.39, p = 0.026), local efficiency (ß = 27.1, p = 0.041) and clustering (ß = 36.1, p = 0.032) and lower small-worldness (ß = -3.27, p = 0.015). Adding graph metrics to conventional MRI improved EDSS (p = 0.045, ΔR2 = 4) and T25FW (p < 0.001, ΔR2 = 13.6) prediction. CONCLUSION: Graph metrics are relevant early in demyelination. They show differences between patients and controls and have relationships with clinical outcomes. Segregation (local efficiency, clustering, transitivity) was particularly relevant. Combining graph metrics with conventional MRI better explained disability.

Using The Virtual Brain to study the relationship between structural and functional connectivity in patients with multiple sclerosis: a multicenter study.

The relationship between structural connectivity (SC) and functional connectivity (FC) captured from magnetic resonance imaging, as well as its interaction with disability and cognitive impairment, is not well understood in people with multiple sclerosis (pwMS). The Virtual Brain (TVB) is an open-source brain simulator for creating personalized brain models using SC and FC. The aim of this study was to explore SC-FC relationship in MS using TVB. Two different model regimes have been studied: stable and oscillatory, with the latter including conduction delays in the brain. The models were applied to 513 pwMS and 208 healthy controls (HC) from 7 different centers. Models were analyzed using structural damage, global diffusion properties, clinical disability, cognitive scores, and graph-derived metrics from both simulated and empirical FC. For the stable model, higher SC-FC coupling was associated with pwMS with low Single Digit Modalities Test (SDMT) score (F=3.48, P$\lt$0.05), suggesting that cognitive impairment in pwMS is associated with a higher SC-FC coupling. Differences in entropy of the simulated FC between HC, high and low SDMT groups (F=31.57, P$\lt$1e-5), show that the model captures subtle differences not detected in the empirical FC, suggesting the existence of compensatory and maladaptive mechanisms between SC and FC in MS.

Outcomes of total shoulder arthroplasty in patients with prior anterior shoulder instability: minimum 5-year follow-up.

BACKGROUND: Patients with a history of anterior shoulder instability (ASI) commonly progress to glenohumeral arthritis or even dislocation arthropathy and often require total shoulder arthroplasty (TSA). The purposes of this study were to (1) report patient-reported outcomes (PROs) after TSA in patients with a history of ASI, (2) compare TSA outcomes of patients whose ASI was managed operatively vs. nonoperatively, and (3) report PROs of TSA in patients who previously underwent arthroscopic vs. open ASI management. METHODS: Patients were included if they had a history of ASI and had undergone TSA ≥5 years earlier, performed by a single surgeon, between October 2005 and January 2017. The exclusion criteria included prior rotator cuff repair, hemiarthroplasty, or glenohumeral joint infection before the index TSA procedure. Patients were separated into 2 groups: those whose ASI was previously operatively managed and those whose ASI was treated nonoperatively. This was a retrospective review of prospective collected data. Data collected was demographic, surgical and subjective. The PROs used were the American Shoulder and Elbow Surgeons score, Single Assessment Numerical Evaluation score, QuickDASH (Quick Disabilities of the Arm, Shoulder and Hand) score, and 12-item Short Form physical component score. Failure was defined as revision TSA surgery, conversion to reverse TSA, or prosthetic joint infection. Kaplan-Meier survivorship analysis was performed. RESULTS: This study included 36 patients (27 men and 9 women) with a mean age of 56.4 years (range, 18.8-72.2 years). Patients in the operative ASI group were younger than those in the nonoperative ASI group (50.6 years vs. 64.0 years, P < .001). Operative ASI patients underwent 10 open and 11 arthroscopic anterior stabilization surgical procedures prior to TSA (mean, 2 procedures; range, 1-4 procedures). TSA failure occurred in 6 of 21 patients with operative ASI (28.6%), whereas no failures occurred in the nonoperative ASI group (P = .03). Follow-up was obtained in 28 of 30 eligible patients (93%) at an average of 7.45 years (range, 5.0-13.6 years). In the collective cohort, the American Shoulder and Elbow Surgeons score, Single Assessment Numerical Evaluation score, QuickDASH (Quick Disabilities of the Arm, Shoulder and Hand) score, and 12-item Short Form physical component score significantly improved, with no differences in the postoperative PROs between the 2 groups. We found no significant differences when comparing PROs between prior open and prior arthroscopic ASI procedures or when comparing the number of prior ASI procedures. Kaplan-Meier analysis demonstrated a 79% 5-year survivorship rate in patients with prior ASI surgery and a 100% survivorship rate in nonoperatively managed ASI patients (P = .030). CONCLUSION: At mid-term follow-up, patients with a history of ASI undergoing TSA can expect continued improvement in function compared with preoperative values. However, TSA survivorship is decreased in patients with a history of ASI surgery compared with those without prior surgery.

Do maternal haemodynamics have a causal influence on treatment for gestational diabetes?

BACKGROUND: Arterial stiffening is believed to contribute to the worsening of insulin resistance, and factors which are associated with needing pharmacological treatment of gestational diabetes (GDM), such as maternal obesity or advanced age, are associated with impaired cardiovascular adaptation to pregnancy. In this observational study, we aimed to investigate causal relationships between maternal haemodynamics and treatment requirement amongst women with GDM. METHODS: We assessed maternal haemodynamics in women with GDM, comparing those who remained on dietary treatment with those who required pharmacological management. Maternal haemodynamics were assessed using the Arteriograph® (TensioMed Ltd, Budapest, Hungary) and the NICOM® non-invasive bio-reactance method (Cheetah Medical, Portland, Oregon, USA). A graphical causal inference technique was used for statistical analysis. RESULTS: 120 women with GDM were included in the analysis. Maternal booking BMI was identified as having a causative influence on treatment requirement, with each unit increase in BMI increasing the odds of needing metformin and/or insulin therapy by 12% [OR 1.12 (1.02 - 1.22)]. The raw values of maternal heart rate (87.6 ± 11.7 vs. 92.9 ± 11.90 bpm, p = 0.014) and PWV (7.8 ± 1.04 vs. 8.4 ± 1.61 m/s, p = 0.029) were both significantly higher amongst the women requiring pharmacological management, though these relationships did not remain significant in causal logistic regression. CONCLUSIONS: Maternal BMI at booking has a causal, rather than simply associational, relationship on the need for pharmacological treatment of GDM. No significant causal relationships were found between maternal haemodynamics and the need for pharmacological treatment.

This observational study is the first to examine relationships between maternal haemodynamics and treatment requirement for gestational diabetes (GDM). This is also the first study to demonstrate a causative, rather than simply associational, relationship between maternal body mass index (BMI) and the need for pharmacological treatment of GDM, with each unit increase in BMI increasing the odds of needing metformin and/or insulin therapy by 12%. Maternal heart rate and pulse wave velocity were significantly higher among women with GDM requiring pharmacological management, but this finding did not remain significant in logistic regression analysis, and no causative relationships between maternal hemodynamics and treatment requirement were identified. Our findings highlight the importance of pre- and peri-conception weight control, but do not support a role for measurement of maternal hemodynamics in the prediction of women who are likely to require pharmacological management of GDM.

Combining three independent pathological stressors induces a heart failure with preserved ejection fraction phenotype.

Heart failure (HF) with preserved ejection fraction (HFpEF) is defined as HF with an ejection fraction (EF) ≥ 50% and elevated cardiac diastolic filling pressures. The underlying causes of HFpEF are multifactorial and not well-defined. A transgenic mouse with low levels of cardiomyocyte (CM)-specific inducible Cavß2a expression (ß2a-Tg mice) showed increased cytosolic CM Ca2+, and modest levels of CM hypertrophy, and fibrosis. This study aimed to determine if ß2a-Tg mice develop an HFpEF phenotype when challenged with two additional stressors, high-fat diet (HFD) and Nω-nitro-l-arginine methyl ester (l-NAME, LN). Four-month-old wild-type (WT) and ß2a-Tg mice were given either normal chow (WT-N, ß2a-N) or HFD and/or l-NAME (WT-HFD, WT-LN, WT-HFD-LN, ß2a-HFD, ß2a-LN, and ß2a-HFD-LN). Some animals were treated with the histone deacetylase (HDAC) (hypertrophy regulators) inhibitor suberoylanilide hydroxamic acid (SAHA) (ß2a-HFD-LN-SAHA). Echocardiography was performed monthly. After 4 mo of treatment, terminal studies were performed including invasive hemodynamics and organs weight measurements. Cardiac tissue was collected. Four months of HFD plus l-NAME treatment did not induce a profound HFpEF phenotype in FVB WT mice. ß2a-HFD-LN (3-Hit) mice developed features of HFpEF, including increased atrial natriuretic peptide (ANP) levels, preserved EF, diastolic dysfunction, robust CM hypertrophy, increased M2-macrophage population, and myocardial fibrosis. SAHA reduced the HFpEF phenotype in the 3-Hit mouse model, by attenuating these effects. The 3-Hit mouse model induced a reliable HFpEF phenotype with CM hypertrophy, cardiac fibrosis, and increased M2-macrophage population. This model could be used for identifying and preclinical testing of novel therapeutic strategies.NEW & NOTEWORTHY Our study shows that three independent pathological stressors (increased Ca2+ influx, high-fat diet, and l-NAME) together produce a profound HFpEF phenotype. The primary mechanisms include HDAC-dependent-CM hypertrophy, necrosis, increased M2-macrophage population, fibroblast activation, and myocardial fibrosis. A role for HDAC activation in the HFpEF phenotype was shown in studies with SAHA treatment, which prevented the severe HFpEF phenotype. This "3-Hit" mouse model could be helpful in identifying novel therapeutic strategies to treat HFpEF.

Effects of maternal hypothyroidism on postnatal cardiomyocyte proliferation and cardiac disease responses of the progeny.

Maternal hypothyroidism (MH) could adversely affect the cardiac disease responses of the progeny. This study tested the hypothesis that MH reduces early postnatal cardiomyocyte (CM) proliferation so that the adult heart of MH progeny has a smaller number of larger cardiac myocytes, which imparts adverse cardiac disease responses following injury. Thyroidectomy (TX) was used to establish MH. The progeny from mice that underwent sham or TX surgery were termed Ctrl (control) or MH (maternal hypothyroidism) progeny, respectively. MH progeny had similar heart weight (HW) to body weight (BW) ratios and larger CM size consistent with fewer CMs at postnatal day 60 (P60) compared with Ctrl (control) progeny. MH progeny had lower numbers of EdU+, Ki67+, and phosphorylated histone H3 (PH3)+ CMs, which suggests they had a decreased CM proliferation in the postnatal timeframe. RNA-seq data showed that genes related to DNA replication were downregulated in P5 MH hearts, including bone morphogenetic protein 10 (Bmp10). Both in vivo and in vitro studies showed Bmp10 treatment increased CM proliferation. After transverse aortic constriction (TAC), the MH progeny had more severe cardiac pathological remodeling compared with the Ctrl progeny. Thyroid hormone (T4) treatment for MH mothers preserved their progeny's postnatal CM proliferation capacity and prevented excessive pathological remodeling after TAC. Our results suggest that CM proliferation during early postnatal development was significantly reduced in MH progeny, resulting in fewer CMs with hypertrophy in adulthood. These changes were associated with more severe cardiac disease responses after pressure overload.NEW & NOTEWORTHY Our study shows that compared with Ctrl (control) progeny, the adult progeny of mothers who have MH (MH progeny) had fewer CMs. This reduction of CM numbers was associated with decreased postnatal CM proliferation. Gene expression studies showed a reduced expression of Bmp10 in MH progeny. Bmp10 has been linked to myocyte proliferation. In vivo and in vitro studies showed that Bmp10 treatment of MH progeny and their myocytes could increase CM proliferation. Differences in CM number and size in adult hearts of MH progeny were linked to more severe cardiac structural and functional remodeling after pressure overload. T4 (synthetic thyroxine) treatment of MH mothers during their pregnancy, prevented the reduction in CM number in their progeny and the adverse response to disease stress.

First-line immunosuppression in neuromuscular diseases.

Autoimmune neuromuscular diseases are common and often treatable causes for peripheral nervous system dysfunction. If not optimally managed, they result in meaningful impairments and disability. The treating neurologist should aim to maximise clinical recovery with minimal iatrogenic risk. This requires careful patient and medication selection, appropriate counselling and close monitoring of clinical efficacy and safety. Here, we summarise our consensus departmental approach to first-line immunosuppression in neuromuscular diseases. We combine multispecialty evidence and expertise with a focus on autoimmune neuromuscular diseases to create guidance on starting, dosing and monitoring for toxic effects of the commonly used drugs. These include corticosteroids, steroid-sparing agents and cyclophosphamide. We also provide efficacy monitoring advice, as clinical response informs dosage and drug choice. The principles of this approach could be applied across much of the spectrum of immune-mediated neurological disorders where there is significant therapeutic crossover.

Sub-ppm gas phase Raman spectroscopy in an anti-resonant hollow core fiber.

We demonstrate recent progress in the development of a Raman gas sensor using a single cladding ring anti-resonant hollow core micro-structured optical fiber (HC-ARF) and a low power pump source. The HC-ARF was designed specifically for low attenuation and wide bandwidth in the visible spectral region and provided low loss at both the pump wavelength (532 nm) and Stokes wavelengths up to a Raman shift of 5000 cm-1. A novel selective core pressurization scheme was also implemented to further reduce the confinement loss, improving the Raman signal enhancement by a factor of 1.9 compared to a standard fiber filling scheme. By exploiting longer lengths of fiber, direct detection of both methane and hydrogen at concentrations of 5 and 10 ppm respectively is demonstrated and a noise equivalent limit-of-detection of 0.15 ppm is calculated for methane.

Editorial Commentary: Shoulder Superior Capsular Reconstruction Graft Tensioning Between 30° and 40° of Glenohumeral Abduction Is Recommended: The Balance Beam of Superior Capsular Reconstruction.

Massive irreparable rotator cuff tears in young, active patients pose a challenging treatment dilemma. Since the relatively recent development of the superior capsular reconstruction (SCR) procedure, the technique has been increasingly used to stave off reverse total shoulder arthroplasty in this demographic. As a result of continued output of supportive literature, both biomechanically and clinically, SCR has been adopted by surgeons despite some technical aspects of the procedure not being fully elucidated. One notable topic of study is the ideal glenohumeral position in which to determine graft length and therefore graft tension. Tensioning inevitably affects glenohumeral joint kinematics, including superior humeral head translation, subacromial contact pressure, and graft healing potential. Although it is currently known that some degree of glenohumeral abduction is necessary for appropriate graft tensioning, and there are some biomechanical studies from our group and other groups that have looked at this, there is not a clinically supported position in which to measure graft length and therefore set graft tension. Well-designed biomechanical studies will serve as the foundation for what is performed clinically. On the basis of the best available evidence, tensioning the graft between 30° and 40° of glenohumeral abduction is recommended and has yielded encouraging clinical outcomes for SCR in our patients.

The connected patient project: moving towards a population-based primary health care research registry.

BACKGROUND: The NHS pledges to give all patients access to clinical research. In England, 32% of General Practices are research active and only 14% of patients engage in research. This project aimed to evaluate consent-for-contact and communication in primary care patients. METHODS: An explanatory mixed methods study of patients and staff within a single general practice. The study included all patients over the age of 18 years, and excluded those on the palliative care register and those unable to give informed consent. The questionnaire asked recipients to indicate their preferred contact method and data-sharing permissions with three organisations: NHS, Universities and Commercial Companies. Survey recipients and staff were invited to take part in a semi-structured interview. Interviews explored project acceptability, feasibility and reasoning behind choices made. Statistical data were triangulated with interview data. RESULTS: The target patient population was 4678, 24% (n = 1148) responded. Seven hundred and three gave permission for at least one of the organisations to contact them. Older people were more likely to respond than young people, (p < 0.001). There was a trend for more women than men to give permissions however, in the 70 years plus age group this was reversed. Short message service was the preferred method of communication (48% n = 330), but those aged 70 years and over, preferred letter (p = 0.001). Interviews suggested patients felt the project was primarily about improving communication and secondly access to research. Patients trusted the NHS and university researchers. Staff interviewees found the project was less onerous than expected. Barriers to wider rollout included workload and the fragmented nature of NHS digital systems. CONCLUSIONS: A registry of patients was established; however, the response rate of 24% needs increasing before wider adoption. Health promotion and chronic disease-based research may recruit better when based in primary health care. Older demographics would be more likely to volunteer for research. NHS and academic researchers are trusted, commercial organisations less so. The move to digitalise communication methods has the potential to marginalise older women. Findings were used to drive forward two novel developments: a consent registry (Research+Me) and a federation-wide participant identification process.

Editorial Commentary: Suprascapular Nerve Decompression Can Be Effective, But Should You Have the Nerve to Do It?

Isolated suprascapular neuropathy that requires surgical decompression is rare. Arthroscopic suprascapular nerve decompression is an effective treatment for correctly indicated patients, but identifying which patients would benefit from decompression is challenging. While good outcomes and low complication rates after arthroscopic suprascapular nerve decompression have been reported by expert surgeons, this procedure has potential for neurovascular injury in inexperienced hands. Given the rarity of the condition, the difficulty with accurate diagnosis, and the potential risks from surgical intervention, we believe that these patients are best treated in a tertiary referral practice.

Review and construction of interatomic potentials for molecular dynamics studies of hydrogen embrittlement in Fe─C based steels.

Reducing hydrogen embrittlement in the low-cost Fe─C based steels have the potential to significantly impact the development of hydrogen energy technologies. Molecular dynamics studies of hydrogen interactions with Fe─C steels provide fundamental information about the behavior of hydrogen at microstructural length scales, although such studies have not been performed due to the lack of an Fe─C─H ternary interatomic potential. In this work, the literature on interatomic potentials related to the Fe─C─H systems are reviewed with the aim of constructing an Fe─C─H potential from the published binary potentials. We found that Fe─C, Fe─H, and C─H bond order potentials exist and can be combined to construct an Fe─C─H ternary potential. Therefore, we constructed two such Fe─C─H potentials and demonstrate that these ternary potentials can reasonably capture hydrogen effects on deformation characteristics and deformation mechanisms for a variety of microstructural variations of the Fe─C steels, including martensite that results from γ to α phase transformation, and pearlite that results from the eutectic formation of the Fe3 C cementite compound.

A randomized clinical trial comparing early active motion programs: Earlier hand function, TAM, and orthotic satisfaction with a relative motion extension program for zones V and VI extensor tendon repairs.

STUDY DESIGN: Randomized clinical trial with parallel groups. INTRODUCTION: Early active mobilization programs are used after zones V and VI extensor tendon repairs; two programs used are relative motion extension (RME) orthosis and controlled active motion (CAM). Although no comparative studies exist, use of the RME orthosis has been reported to support earlier hand function. PURPOSE OF THE STUDY: This randomized clinical trial investigated whether patients managed with an RME program would recover hand function earlier postoperatively than those managed with a CAM program. METHODS: Forty-two participants with zones V-VI extensor tendon repairs were randomized into either a CAM or RME program. The Sollerman Hand Function Test (SHFT) was the primary outcome measure of hand function. Days to return to work, QuickDASH (Disabilities of Arm, Shoulder and Hand) questionnaire, total active motion (TAM), grip strength, and patient satisfaction were the secondary measures of outcome. RESULTS: The RME group demonstrated better results at four weeks for the SHFT score (P = .0073; 95% CI: -10.9, -1.8), QuickDASH score (P = .05; 95% CI: -0.05, 19.5), and TAM (P = .008; 95% CI: -65.4, -10.6). Days to return to work were similar between groups (P = .77; 95% CI: -28.1, 36.1). RME participants were more satisfied with the orthosis (P < .0001; 95% CI: 3.5, 8.4). No tendon ruptures occurred. DISCUSSION: Participants managed using an RME program, and RME finger orthosis demonstrated significantly better early hand function, TAM, and orthosis satisfaction than those managed by the CAM program using a static wrist-hand-finger orthosis. This is likely due to the less restrictive design of the RME orthosis. CONCLUSIONS: The RME program supports safe earlier recovery of hand function and motion when compared to a CAM program following repair of zones V and VI extensor tendons.

Correlating structure and transport behavior in Li+ and O2 containing pyrrolidinium ionic liquids.

Ionic liquids are a unique class of materials with several potential applications in electrochemical energy storage. When used in electrolytes, these highly coordinating solvents can influence device performance through their high viscosities and strong solvation behaviors. In this work, we explore the effects of pyrrolidinium cation structure and Li+ concentration on transport processes in ionic liquid electrolytes. We present correlated experimental measurements and molecular simulations of Li+ mobility and O2 diffusivity, and connect these results to dynamic molecular structural information and device performance. In the context of Li-O2/Li-air battery chemistries, we find that Li+ mobility is largely influenced by Li+-anion coordination, but that both Li+ and O2 diffusion may be affected by variations of the pyrrolidinium cation and Li+ concentration.

Orthopaedic surgery patients who use recreational marijuana have less pre-operative pain.

AIMS: To determine the baseline clinical characteristics of recreational marijuana users undergoing outpatient orthopaedic surgery. We hypothesized that patients who report marijuana use would have worse pain, function, and general health status. PATIENTS AND METHODS: Nine-hundred and thirty-seven patients undergoing outpatient orthopaedic surgery were asked to fill out patient-reported outcome (PRO) tools. These PROs included the Patient-Reported Outcomes Measurement Information Systems (PROMIS) computer adaptive tests and legacy PROs unique to each patients' surgical site. RESULTS: Forty patients (4.2%) reported marijuana use. Marijuana use was associated with younger age (33 vs. 43 years, p < 0.001), having a history of fewer operations (1.8 vs. 3.2, p < 0.05), single marital status (68 vs. 38%, p < 0.01), and having a history of smoking cigarettes (63 vs. 31%, p < 0.0001). Marijuana use was found to be significantly associated with greater Marx lower extremity activity rating scale scores (8.5 points vs. 6.1 points, p < 0.05) and decreased pain intensity in the operative site (3.7 points vs. 5.0 points, p < 0.05). Multivariable analysis found that marijuana use was an independent factor associated with less pain intensity in the operative site (p < 0.05). CONCLUSION: Our studies support other national studies that report increased marijuana use among younger patients and those who smoke cigarettes. The results do not support our hypothesis, as marijuana use was associated with less pain and better lower extremity activity rating scale scores when compared to non-users. Further research is warranted to analyze the effects of marijuana use on orthopaedic surgery patients. STUDY DESIGN: Cross-sectional study.

An Fe-Ni-Cr embedded atom method potential for austenitic and ferritic systems.

Fe-Ni-Cr stainless-steels are important structural materials because of their superior strength and corrosion resistance. Atomistic studies of mechanical properties of stainless-steels, however, have been limited by the lack of high-fidelity interatomic potentials. Here using density functional theory as a guide, we have developed a new Fe-Ni-Cr embedded atom method potential. We demonstrate that our potential enables stable molecular dynamics simulations of stainless-steel alloys at high temperatures, accurately reproduces the stacking fault energy-known to strongly influence the mode of plastic deformation (e.g., twinning vs. dislocation glide vs. cross-slip)-of these alloys over a range of compositions, and gives reasonable elastic constants, energies, and volumes for various compositions. The latter are pertinent for determining short-range order and solute strengthening effects. Our results suggest that our potential is suitable for studying mechanical properties of austenitic and ferritic stainless-steels which have vast implementation in the scientific and industrial communities. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Deep convolutional neural networks for Raman spectrum recognition: a unified solution.

Machine learning methods have found many applications in Raman spectroscopy, especially for the identification of chemical species. However, almost all of these methods require non-trivial preprocessing such as baseline correction and/or PCA as an essential step. Here we describe our unified solution for the identification of chemical species in which a convolutional neural network is trained to automatically identify substances according to their Raman spectrum without the need for preprocessing. We evaluated our approach using the RRUFF spectral database, comprising mineral sample data. Superior classification performance is demonstrated compared with other frequently used machine learning algorithms including the popular support vector machine method.

The impact of insurance coverage and the family on pediatric diabetes management.

BACKGROUND/OBJECTIVE: The impact of family composition on glycemic control in children with type 1 diabetes remains unclear. We sought to evaluate the relationship between health insurance coverage, family composition, and insulin management, and assess their impact on glycemic control in a pediatric type 1 diabetes population. METHODS: A retrospective chart review was completed for patients seen in the Pediatric Endocrinology Clinic at the University of Louisville in 2012. RESULTS: The analysis included 729 patients with type 1 diabetes; 268 (37%) had public insurance while 461(63%) had private insurance. Compared with publicly insured patients, privately insured patients had higher rates of intensive insulin management with multiple daily injections (MDI) plans or pump devices (88 vs. 83.2%, p = 0.066) and lower HbA1c levels [8.57 vs. 9.39% (70 vs. 79 mmol/mol), p < 0.001]. Of the 729 patients, 243 were in single-adult homes (33%). Single-adult homes had higher HbA1c levels than two-adult homes, [9.3 vs. 8.6% (78 vs. 70 mmol/mol), p < 0.001]. Among publicly insured, there was no difference in HbA1c levels for single-adult vs. two-adult homes [9.4 (79 mmol/mol), p = 0.868]. For privately insured, patients in single-adult homes had higher HbA1c levels than peers in two-adult homes [9.2 vs. 8.4% (77 vs. 68), p < 0.001]. CONCLUSION: Insurance type and family composition have significant associative effects on glycemic control and insulin management that may be mitigated by insulin pump therapy. Identifying and addressing factors such as availability of resources, family education, and adult support and supervision, may help improve glycemic control in high-risk pediatric diabetes patients.

Two-dimensional metal-organic frameworks with high thermoelectric efficiency through metal ion selection.

Two-dimensional (2D) materials have attracted much attention due to their novel properties. An exciting new class of 2D materials based on metal-organic frameworks (MOFs) has recently emerged, displaying high electrical conductivity, a rarity among organic nanoporous materials. The emergence of these materials raises intriguing questions about their fundamental electronic, optical, and thermal properties, but few studies exist in this regard. Here we present an atomistic study of the thermoelectric properties of crystalline 2D MOFs X3(HITP)2 with X = Ni, Pd or Pt, and HITP = 2,3,6,7,10,11-hexaiminotriphenylene, using both ab initio transport models and classical molecular dynamics simulations. We find that these materials have a high Seebeck coefficient and low thermal conductivity, making them promising for thermoelectric applications. Furthermore, we explore the dependence of thermoelectric transport properties on the atomic structure by comparing the calculated band structure, band alignment, and electronic density of states of the three 2D MOFs, and find that the thermoelectric transport properties strongly depend on both the interaction between the ligands and the metal ions, and the d orbital splitting of the metal ions induced by the ligands. This demonstrates that selection of the metal ion is a powerful approach to control and enhance the thermoelectric properties. Interestingly we reveal an unexpected effect where, unlike for electrons, the thermal and electrical current may not be equally carried by the holes, leading to a significant deviation from the Wiedemann-Franz law. The results of this work provide fundamental guidance to optimize the existing 2D MOFs, and to design and discover new families of MOF-like materials for thermoelectric applications.