Ultrasound Stimulation of a Piezoelectric Composite with Compliant Layers on Power Output for Bone Healing in Spinal Fusion Applications

Spinal fusion devices have up to 50% failure rates for patients who smoke or are diabetic 1. Bone healing has been accomplished through direct current (DC) electrical stimulation to improve bone healing rates 2. Current DC electrical stimulation can accomplish bone healing, but batteries are used as a source of power. Replacing a battery after fusion would require a second surgery. Many microgenerators use piezoelectric material to convert mechanical energy into electrical potential 3. In a pilot ovine study, composite spinal interbody implants made with stacked layers of piezoelectric fibers provided DC electrical stimulation at the fusion site and substantially enhanced fusion under normal loading after six weeks as compared to a control 2,4,5. To improve manufacturability while maintaining material toughness of the interbody implants, alternative manufacturing methods were explored in which compliant layers of epoxy (EPO-TEK® 301, Billerica, MA) were inserted between stacked discs of piezoelectric material, PZT-SM111 (STEMiNC-0.4mm thickness, 10mm diameter, Part No. SMD10T04F5000S111, Doral, FL). For patients with limited weight bearing abilities that cannot provide enough mechanical energy from human body movement, another method of mechanically stimulating the PZT discs would be beneficial. Many methods of wirelessly powering medical devices have been investigated including electromagnetic waves, thermoelectric devices, and ultrasound 3. Transmitted ultrasound waves can be used to mechanically activate a medical device implanted into human tissue with PZT elements 3. Using ultrasound as the loading source, the effect of varying compliant layer thicknesses on generated electrical potential and power output of the PZT compliant layer adaptive composite stacks (CLACS) in different media (water, tissue, and tissue plus bone), media thicknesses (20mm and 40mm), and loading orientations of the PZT composites with respect to the ultrasound wave front (perpendicular and parallel) were investigated. An Acuson 128xp ultrasound medical imaging machine (Mountain View, CA) was used to mechanically stimulate the PZT elements in the compliant layer thickness composites and voltage measurements were made with a Tektronix (Beaverton, OR) DPO 3034 Digital Phosphor Oscilloscope (300 MHz). The PZT composite was manufactured with six through thickness pre-poled PZT-SM511 discs (STEMiNC-0.4mm thickness, 10mm diameter, Part No. SMD10T04F5000S111, Doral, FL) that were connected electrically in parallel (EPO-TEK® H20E, Billerica, MA) with copper strips, varying compliant layer thickness (0, 0.2, 0.4, and 0.8 mm ± 0.02 mm) of medical grade epoxy slices (EPO-TEK® 301, Billerica, MA) interposed between the PZT discs, and encapsulated in medical grade epoxy (EPO-TEK® 301, Billerica, MA). After assembly, the CLACS were tested at each combination of media type, media thickness, and loading orientations. The CLACS were subject to 4MHz ultrasound waves (1 W) in a Gaussian shape pattern with a V4 vector 128 PZT element array probe (Mountain View, CA). Voltage measurements before rectification (alternating current - AC) and after rectification (direct current - DC) were recorded. Power was computed after rectification by applying an average voltage measured across the lumped internal Oscilloscope channel impedance (1 MΩ) with the influence of a variable load resistance (Ω) and capacitor (c) connected in parallel and then using P=V^2/R by combining Joule’s and Ohm’s law. By adding a compliant layer thickness in between the PZT discs of the CLACS, generated electrical potential and power output increased. As the compliant layer thickness increased there were significant increases in power output due to more deformation that occurred along the entire face and edges of the PZT discs. As media thickness increased, DC power output decreased. The CLACS produced the most power with water as the media. Significantly less power was produced in tissue media, and even less in the tissue plus bone medium (p<0.05 BoxCox Transformation). When the stacked PZT layers were being loaded perpendicular to the wave front of the ultrasound waves, there was significantly more power output than when the stacked PZT layers were being loaded parallel to the ultrasound wave front (p<0.05 BoxCox Transformation). Future work could build off this foundational study to further characterize the CLACS power output behavior. These future studies would include focused vs. unfocused ultrasound loading sources to increase the amount of mechanical energy that influences the CLACS, differing operating frequencies to match and mismatch the resonant frequency of the PZT discs and to determine optimum frequencies for certain media depths, testing more varied loading orientations, differing ultrasound intensity levels, using a combination of radially and through-thickness poled PZT discs, designing circuit components to improve electrical energy transfer (impedance matching) efficiency and implementing pulsed DC circuit logic after rectification to approach a more realistic application of DC electrical stimulation in bone healing for spinal fusion

A Unified Account of the Moral Standing to Blame

Recently, philosophers have turned their attention to the question, not when a given agent is blameworthy for what she does, but when a further agent has the moral standing to blame her for what she does. Philosophers have proposed at least four conditions on having “moral standing”: 1. One’s blame would not be “hypocritical”. 2. One is not oneself “involved in” the target agent’s wrongdoing. 3. One must be warranted in believing that the target is indeed blameworthy for the wrongdoing. 4. The target’s wrongdoing must some of “one’s business”. These conditions are often proposed as both conditions on one and the same thing, and as marking fundamentally different ways of “losing standing.” Here I call these claims into question. First, I claim that conditions (3) and (4) are simply conditions on different things than are conditions (1) and (2). Second, I argue that condition (2) reduces to condition (1): when “involvement” removes someone’s standing to blame, it does so only by indicating something further about that agent, viz., that he or she lacks commitment to the values that condemn the wrongdoer’s action. The result: after we clarify the nature of the non-hypocrisy condition, we will have a unified account of moral standing to blame. Issues also discussed: whether standing can ever be regained, the relationship between standing and our "moral fragility", the difference between mere inconsistency and hypocrisy, and whether a condition of standing might be derived from deeper facts about the "equality of persons"

Trichomonas vaginalis Infection and Associated Risk Factors in a Socially-Marginalized Female Population in Coastal Peru

Objective. The epidemiology of Trichomonas vaginalis infection among sexually active socially-marginalized women in three urban, coastal Peruvian cities was examined in order to quantify the prevalence of trichomonas infection and identify associated risk factors. Methods. We conducted a cross-sectional, venue-based study of women from socially-marginalized populations in three coastal Peruvian cities. Results. Among the 319 women enrolled, the overall prevalence of trichomonal infection was 9.1% (95% CI, 5.9%–12.3%). The mean age was 26.3 years, and 35.5% reported having had unprotected intercourse with nonprimary partners and 19.8% reported two or more sex partners in the last three months. Trichomonal infection was associated with increased number of sex partners (PR 2.5, 95% CI 1.4–4.6) and unprotected sex with nonprimary partner in the last three months (PR 2.3, 95% CI 1.1–4.9). Conclusions. A moderately high prevalence of trichomonal infection was found among women in our study. Trichomonal infection was associated with unprotected sex and multiple sex partners. Efforts to control the continued spread of trichomonal infection are warranted

Amazonian Amphibian Diversity Is Primarily Derived from Late Miocene Andean Lineages

The Neotropics contains half of remaining rainforests and Earth's largest reservoir of amphibian biodiversity. However, determinants of Neotropical biodiversity (i.e., vicariance, dispersals, extinctions, and radiations) earlier than the Quaternary are largely unstudied. Using a novel method of ancestral area reconstruction and relaxed Bayesian clock analyses, we reconstructed the biogeography of the poison frog clade (Dendrobatidae). We rejected an Amazonian center-of-origin in favor of a complex connectivity model expanding over the Neotropics. We inferred 14 dispersals into and 18 out of Amazonia to adjacent regions; the Andes were the major source of dispersals into Amazonia. We found three episodes of lineage dispersal with two interleaved periods of vicariant events between South and Central America. During the late Miocene, Amazonian, and Central American-Chocoan lineages significantly increased their diversity compared to the Andean and Guianan-Venezuelan-Brazilian Shield counterparts. Significant percentage of dendrobatid diversity in Amazonia and Chocó resulted from repeated immigrations, with radiations at <10.0 million years ago (MYA), rather than in situ diversification. In contrast, the Andes, Venezuelan Highlands, and Guiana Shield have undergone extended in situ diversification at near constant rate since the Oligocene. The effects of Miocene paleogeographic events on Neotropical diversification dynamics provided the framework under which Quaternary patterns of endemism evolved

Certolizumab pegol and secukinumab for treating active psoriatic arthritis following inadequate response to disease-modifying antirheumatic drugs : a systematic review and economic evaluation

BACKGROUND: Several biologic therapies are approved by the National Institute for Health and Care Excellence (NICE) for psoriatic arthritis (PsA) patients who have had an inadequate response to two or more synthetic disease-modifying antirheumatic drugs (DMARDs). NICE does not specifically recommend switching from one biologic to another, and only ustekinumab (UST; STELARA(®), Janssen Pharmaceuticals, Inc., Horsham, PA, USA) is recommended after anti-tumour necrosis factor failure. Secukinumab (SEC; COSENTYX(®), Novartis International AG, Basel, Switzerland) and certolizumab pegol (CZP; CIMZIA(®), UCB Pharma, Brussels, Belgium) have not previously been appraised by NICE. OBJECTIVE: To determine the clinical effectiveness and cost-effectiveness of CZP and SEC for treating active PsA in adults in whom DMARDs have been inadequately effective. DESIGN: Systematic review and economic model. DATA SOURCES: Fourteen databases (including MEDLINE and EMBASE) were searched for relevant studies from inception to April 2016 for CZP and SEC studies; update searches were run to identify new comparator studies. REVIEW METHODS: Clinical effectiveness data from randomised controlled trials (RCTs) were synthesised using Bayesian network meta-analysis (NMA) methods to investigate the relative efficacy of SEC and CZP compared with comparator therapies. A de novo model was developed to assess the cost-effectiveness of SEC and CZP compared with the other relevant comparators. The model was specified for three subpopulations, in accordance with the NICE scope (patients who have taken one prior DMARD, patients who have taken two or more prior DMARDs and biologic-experienced patients). The models were further classified according to the level of concomitant psoriasis. RESULTS: Nineteen eligible RCTs were included in the systematic review of short-term efficacy. Most studies were well conducted and were rated as being at low risk of bias. Trials of SEC and CZP demonstrated clinically important efficacy in all key clinical outcomes. At 3 months, patients taking 150 mg of SEC [relative risk (RR) 6.27, 95% confidence interval (CI) 2.55 to 15.43] or CZP (RR 3.29, 95% CI 1.94 to 5.56) were more likely to be responders than patients taking placebo. The NMA results for the biologic-naive subpopulations indicated that the effectiveness of SEC and CZP relative to other biologics and each other was uncertain. Limited data were available for the biologic-experienced subpopulation. Longer-term evidence suggested that these newer biologics reduced disease progression, with the benefits being similar to those seen for older biologics. The de novo model generated incremental cost-effectiveness ratios (ICERs) for three subpopulations and three psoriasis subgroups. In subpopulation 1 (biologic-naive patients who had taken one prior DMARD), CZP was the optimal treatment in the moderate-severe psoriasis subgroup and 150 mg of SEC was optimal in the subgroups of patients with mild-moderate psoriasis or no concomitant psoriasis. In subpopulation 2 (biologic-naive patients who had taken two or more prior DMARDs), etanercept (ETN; ENBREL(®), Pfizer Inc., New York City, NY, USA) is likely to be the optimal treatment in all subgroups. The ICERs for SEC and CZP versus best supportive care are in the region of £20,000-30,000 per quality-adjusted life-year (QALY). In subpopulation 3 (biologic-experienced patients or patients in whom biologics are contraindicated), UST is likely to be the optimal treatment (ICERs are in the region of £21,000-27,000 per QALY). The optimal treatment in subpopulation 2 was sensitive to the choice of evidence synthesis model. In subpopulations 2 and 3, results were sensitive to the algorithm for Health Assessment Questionnaire-Disability Index costs. The optimal treatment is not sensitive to the use of biosimilar prices for ETN and infliximab (REMICADE(®), Merck Sharp & Dohme, Kenilworth, NJ, USA). CONCLUSIONS: SEC and CZP may be an effective use of NHS resources, depending on the subpopulation and subgroup of psoriasis severity. There are a number of limitations to this assessment, driven mainly by data availability. FUTURE WORK: Trials are needed to inform effectiveness of biologics in biologic-experienced populations. STUDY REGISTRATION: This study is registered as PROSPERO CRD42016033357. FUNDING: The National Institute for Health Research Health Technology Assessment programme

Progress and prospects for event tourism research

This paper examines event tourism as a field of study and area of professional practice updating the previous review article published in 2008. In this substantially extended review, a deeper analysis of the field’s evolution and development is presented, charting the growth of the literature, focusing both chronologically and thematically. A framework for understanding and creating knowledge about events and tourism is presented, forming the basis which signposts established research themes and concepts and outlines future directions for research. In addition, the review article focuses on constraining and propelling forces, ontological advances, contributions from key journals, and emerging themes and issues. It also presents a roadmap for research activity in event tourism

Global, regional, and national disability-adjusted life-years (DALYs) for 315 diseases and injuries and healthy life expectancy (HALE), 1990-2015:a systematic analysis for the Global Burden of Disease Study 2015

Background Healthy life expectancy (HALE) and disability-adjusted life-years (DALYs) provide summary measures of health across geographies and time that can inform assessments of epidemiological patterns and health system performance, help to prioritise investments in research and development, and monitor progress toward the Sustainable Development Goals (SDGs). We aimed to provide updated HALE and DALYs for geographies worldwide and evaluate how disease burden changes with development.Methods We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) for all-cause mortality, cause-specific mortality, and non-fatal disease burden to derive HALE and DALYs by sex for 195 countries and territories from 1990 to 2015. We calculated DALYs by summing years of life lost (YLLs) and years of life lived with disability (YLDs) for each geography, age group, sex, and year. We estimated HALE using the Sullivan method, which draws from age-specific death rates and YLDs per capita. We then assessed how observed levels of DALYs and HALE differed from expected trends calculated with the Socio-demographic Index (SDI), a composite indicator constructed from measures of income per capita, average years of schooling, and total fertility rate.Findings Total global DALYs remained largely unchanged from 1990 to 2015, with decreases in communicable, neonatal, maternal, and nutritional (Group 1) disease DALYs off set by increased DALYs due to non-communicable diseases (NCDs). Much of this epidemiological transition was caused by changes in population growth and ageing, but it was accelerated by widespread improvements in SDI that also correlated strongly with the increasing importance of NCDs. Both total DALYs and age-standardised DALY rates due to most Group 1 causes significantly decreased by 2015, and although total burden climbed for the majority of NCDs, age-standardised DALY rates due to NCDs declined. Nonetheless, age-standardised DALY rates due to several high-burden NCDs (including osteoarthritis, drug use disorders, depression, diabetes, congenital birth defects, and skin, oral, and sense organ diseases) either increased or remained unchanged, leading to increases in their relative ranking in many geographies. From 2005 to 2015, HALE at birth increased by an average of 2.9 years (95% uncertainty interval 2.9-3.0) for men and 3.5 years (3.4-3.7) for women, while HALE at age 65 years improved by 0.85 years (0.78-0.92) and 1.2 years (1.1-1.3), respectively. Rising SDI was associated with consistently higher HALE and a somewhat smaller proportion of life spent with functional health loss; however, rising SDI was related to increases in total disability. Many countries and territories in central America and eastern sub-Saharan Africa had increasingly lower rates of disease burden than expected given their SDI. At the same time, a subset of geographies recorded a growing gap between observed and expected levels of DALYs, a trend driven mainly by rising burden due to war, interpersonal violence, and various NCDs.Interpretation Health is improving globally, but this means more populations are spending more time with functional health loss, an absolute expansion of morbidity. The proportion of life spent in ill health decreases somewhat with increasing SDI, a relative compression of morbidity, which supports continued efforts to elevate personal income, improve education, and limit fertility. Our analysis of DALYs and HALE and their relationship to SDI represents a robust framework on which to benchmark geography-specific health performance and SDG progress. Country-specific drivers of disease burden, particularly for causes with higher-than-expected DALYs, should inform financial and research investments, prevention efforts, health policies, and health system improvement initiatives for all countries along the development continuum. Copyright (C) The Author(s). Published by Elsevier Ltd.</p

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Changes in health in England, with analysis by English regions and areas of deprivation, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.

BACKGROUND: In the Global Burden of Disease Study 2013 (GBD 2013), knowledge about health and its determinants has been integrated into a comparable framework to inform health policy. Outputs of this analysis are relevant to current policy questions in England and elsewhere, particularly on health inequalities. We use GBD 2013 data on mortality and causes of death, and disease and injury incidence and prevalence to analyse the burden of disease and injury in England as a whole, in English regions, and within each English region by deprivation quintile. We also assess disease and injury burden in England attributable to potentially preventable risk factors. England and the English regions are compared with the remaining constituent countries of the UK and with comparable countries in the European Union (EU) and beyond. METHODS: We extracted data from the GBD 2013 to compare mortality, causes of death, years of life lost (YLLs), years lived with a disability (YLDs), and disability-adjusted life-years (DALYs) in England, the UK, and 18 other countries (the first 15 EU members [apart from the UK] and Australia, Canada, Norway, and the USA [EU15+]). We extended elements of the analysis to English regions, and subregional areas defined by deprivation quintile (deprivation areas). We used data split by the nine English regions (corresponding to the European boundaries of the Nomenclature for Territorial Statistics level 1 [NUTS 1] regions), and by quintile groups within each English region according to deprivation, thereby making 45 regional deprivation areas. Deprivation quintiles were defined by area of residence ranked at national level by Index of Multiple Deprivation score, 2010. Burden due to various risk factors is described for England using new GBD methodology to estimate independent and overlapping attributable risk for five tiers of behavioural, metabolic, and environmental risk factors. We present results for 306 causes and 2337 sequelae, and 79 risks or risk clusters. FINDINGS: Between 1990 and 2013, life expectancy from birth in England increased by 5·4 years (95% uncertainty interval 5·0-5·8) from 75·9 years (75·9-76·0) to 81·3 years (80·9-81·7); gains were greater for men than for women. Rates of age-standardised YLLs reduced by 41·1% (38·3-43·6), whereas DALYs were reduced by 23·8% (20·9-27·1), and YLDs by 1·4% (0·1-2·8). For these measures, England ranked better than the UK and the EU15+ means. Between 1990 and 2013, the range in life expectancy among 45 regional deprivation areas remained 8·2 years for men and decreased from 7·2 years in 1990 to 6·9 years in 2013 for women. In 2013, the leading cause of YLLs was ischaemic heart disease, and the leading cause of DALYs was low back and neck pain. Known risk factors accounted for 39·6% (37·7-41·7) of DALYs; leading behavioural risk factors were suboptimal diet (10·8% [9·1-12·7]) and tobacco (10·7% [9·4-12·0]). INTERPRETATION: Health in England is improving although substantial opportunities exist for further reductions in the burden of preventable disease. The gap in mortality rates between men and women has reduced, but marked health inequalities between the least deprived and most deprived areas remain. Declines in mortality have not been matched by similar declines in morbidity, resulting in people living longer with diseases. Health policies must therefore address the causes of ill health as well as those of premature mortality. Systematic action locally and nationally is needed to reduce risk exposures, support healthy behaviours, alleviate the severity of chronic disabling disorders, and mitigate the effects of socioeconomic deprivation. FUNDING: Bill & Melinda Gates Foundation and Public Health England.Bill & Melinda Gates Foundation; Public Health EnglandThis is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/S0140-6736(15)00195-