Machine-Learning Optimized Measurements of Chaotic Dynamical Systems via the Information Bottleneck.

Deterministic chaos permits a precise notion of a "perfect measurement" as one that, when obtained repeatedly, captures all of the information created by the system's evolution with minimal redundancy. Finding an optimal measurement is challenging and has generally required intimate knowledge of the dynamics in the few cases where it has been done. We establish an equivalence between a perfect measurement and a variant of the information bottleneck. As a consequence, we can employ machine learning to optimize measurement processes that efficiently extract information from trajectory data. We obtain approximately optimal measurements for multiple chaotic maps and lay the necessary groundwork for efficient information extraction from general time series.

Information decomposition in complex systems via machine learning.

One of the fundamental steps toward understanding a complex system is identifying variation at the scale of the system's components that is most relevant to behavior on a macroscopic scale. Mutual information provides a natural means of linking variation across scales of a system due to its independence of functional relationship between observables. However, characterizing the manner in which information is distributed across a set of observables is computationally challenging and generally infeasible beyond a handful of measurements. Here, we propose a practical and general methodology that uses machine learning to decompose the information contained in a set of measurements by jointly optimizing a lossy compression of each measurement. Guided by the distributed information bottleneck as a learning objective, the information decomposition identifies the variation in the measurements of the system state most relevant to specified macroscale behavior. We focus our analysis on two paradigmatic complex systems: a Boolean circuit and an amorphous material undergoing plastic deformation. In both examples, the large amount of entropy of the system state is decomposed, bit by bit, in terms of what is most related to macroscale behavior. The identification of meaningful variation in data, with the full generality brought by information theory, is made practical for studying the connection between micro- and macroscale structure in complex systems.

The impact of badmouthing of medical specialties to medical students.

OBJECTIVES: This study aimed to evaluate the proportion of Irish medical students exposed to 'badmouthing' of different specialities and to ascertain: the degree of criticism of specialities based on the seniority of clinical or academic members of staff; if 'badmouthing' influenced student career choice in psychiatry; and attitudes of medical students towards psychiatry as a speciality and career choice. METHODS: Medical students in three Irish universities were invited to complete an online survey to determine the frequency and effect of non-constructive criticism on choice of medical specialty. The online questionnaire was distributed to Royal College of Surgeons in Ireland (RCSI), University of Galway (UoG) and University College Dublin (UCD) in the academic year 2020-2021. RESULTS: General practice (69%), surgery (65%) and psychiatry (50%) were the most criticised specialties. Criticism was most likely to be heard from medical students. 46% of students reported reconsidering a career in psychiatry due to criticism from junior doctors. There was a positive perception of psychiatry with 27% of respondents considering psychiatry as a first-choice specialty. CONCLUSIONS: Criticism of psychiatry by doctors, academics and student peers negatively influences students' career choice, which could be contributing to recruitment difficulties in psychiatry.

Cost Effectiveness of Endovascular Ultrasound Renal Denervation in Patients with Resistant Hypertension.

BACKGROUND: Resistant hypertension (rHTN) is defined as blood pressure (BP) of ≥ 140/90 mmHg despite treatment with at least three antihypertensive medications, including a diuretic. Endovascular ultrasound renal denervation (uRDN) aims to control BP alongside conventional BP treatment with antihypertensive medication. This analysis assesses the cost effectiveness of the addition of the Paradise uRDN System compared with standard of care alone in patients with rHTN from the perspective of the United Kingdom (UK) health care system. METHODS: Using RADIANCE-HTN TRIO trial data, we developed a state-transition model. Baseline risk was calculated using Framingham and Prospective Cardiovascular Münster (PROCAM) risk equations to estimate the long-term cardiovascular risks in patients treated with the Paradise uRDN System, based on the observed systolic BP (SBP) reduction following uRDN. Relative risks sourced from a meta-analysis of randomised controlled trials were then used to project cardiovascular events in patients with baseline SBP ('control' patients); utility and mortality inputs and costs were derived from UK data. Costs and outcomes were discounted at 3.5% per annum. Modelled outcomes were validated against trial meta-analyses and the QRISK3 algorithm and real-world evidence of RDN effectiveness. One-way and probabilistic sensitivity analyses were conducted to assess the uncertainty surrounding the model inputs and sensitivity of the model results to changes in parameter inputs. Results were reported as incremental cost-effectiveness ratios (ICERs). RESULTS: A mean reduction in office SBP of 8.5 mmHg with uRDN resulted in an average improvement in both absolute life-years (LYs) and quality-adjusted life-years (QALYs) gained compared with standard of care alone (0.73 LYs and 0.67 QALYs). The overall base-case ICER with uRDN was estimated at £5600 (€6500) per QALY gained (95% confidence interval £5463-£5739 [€6341-€6661]); modelling demonstrated > 99% probability that the ICER is below the £20,000-£30,000 (€23,214-€34,821) per QALYs gained willingness-to-pay threshold in the UK. Results were consistent across sensitivity analyses and validation checks. CONCLUSIONS: Endovascular ultrasound RDN with the Paradise system offers patients with rHTN, clinicians, and healthcare systems a cost-effective treatment option alongside antihypertensive medication.

Source-based morphometry reveals structural brain pattern abnormalities in 22q11.2 deletion syndrome.

22q11.2 deletion syndrome (22q11DS) is the most frequently occurring microdeletion in humans. It is associated with a significant impact on brain structure, including prominent reductions in gray matter volume (GMV), and neuropsychiatric manifestations, including cognitive impairment and psychosis. It is unclear whether GMV alterations in 22q11DS occur according to distinct structural patterns. Then, 783 participants (470 with 22q11DS: 51% females, mean age [SD] 18.2 [9.2]; and 313 typically developing [TD] controls: 46% females, mean age 18.0 [8.6]) from 13 datasets were included in the present study. We segmented structural T1-weighted brain MRI scans and extracted GMV images, which were then utilized in a novel source-based morphometry (SBM) pipeline (SS-Detect) to generate structural brain patterns (SBPs) that capture co-varying GMV. We investigated the impact of the 22q11.2 deletion, deletion size, intelligence quotient, and psychosis on the SBPs. Seventeen GMV-SBPs were derived, which provided spatial patterns of GMV covariance associated with a quantitative metric (i.e., loading score) for analysis. Patterns of topographically widespread differences in GMV covariance, including the cerebellum, discriminated individuals with 22q11DS from healthy controls. The spatial extents of the SBPs that revealed disparities between individuals with 22q11DS and controls were consistent with the findings of the univariate voxel-based morphometry analysis. Larger deletion size was associated with significantly lower GMV in frontal and occipital SBPs; however, history of psychosis did not show a strong relationship with these covariance patterns. 22q11DS is associated with distinct structural abnormalities captured by topographical GMV covariance patterns that include the cerebellum. Findings indicate that structural anomalies in 22q11DS manifest in a nonrandom manner and in distinct covarying anatomical patterns, rather than a diffuse global process. These SBP abnormalities converge with previously reported cortical surface area abnormalities, suggesting disturbances of early neurodevelopment as the most likely underlying mechanism.

Management of Tarlov cysts: an uncommon but potentially serious spinal column disease-review of the literature and experience with over 1000 referrals.

Tarlov cysts were thought to be anatomic variants of uncertain etiology and clinical significance when initially described over 80 years ago. They are often detected in routine lumbosacral imaging and generally not reported in a differential diagnosis. There is increasing evidence that at least some Tarlov cysts are symptomatic and can have a significant adverse impact on patients' health and well-being. Women are disproportionately affected with this condition, often presenting with long-standing pain and neurological dysfunctions. Significant gender bias has been a concern in the management of these patients. Unfortunately, there is no consensus on patient selection or management approaches for symptomatic Tarlov cysts. This review article updates information on the prevalence, diagnosis, clinical significance, and treatments of these cysts. Based on these findings and experience with over 1000 patient referrals, a treatment decision algorithm for symptomatic Tarlov cysts was constructed to provide guidance for appropriate management of patients with these complex cysts.

Improving the biological realism of predator-prey size relationships in food web models alters ecosystem dynamics.

Body-size relationships between predators and prey exhibit remarkable diversity. However, the assumption that predators typically consume proportionally smaller prey often underlies size-dependent predation in ecosystem models. In reality, some animals can consume larger prey or exhibit limited changes in prey size as they grow larger themselves. These distinct predator-prey size relationships challenge the conventional assumptions of traditional size-based models. Cephalopods, with their diverse feeding behaviours and life histories, offer an excellent case study to investigate the impact of greater biological realism in predator-prey size relationships on energy flow within a size-structured ecosystem model. By categorizing cephalopods into high and low-activity groups, in line with empirically derived, distinct predator-prey size relationships, we found that incorporating greater biological realism in size-based feeding reduced ecosystem biomass and production, while simultaneously increasing biomass stability and turnover. Our results have broad implications for ecosystem modelling, since distinct predator-prey size relationships extend beyond cephalopods, encompassing a wide array of major taxonomic groups from filter-feeding fishes to baleen whales. Incorporating a diversity of size-based feeding in food web models can enhance their ecological and predictive accuracy when studying ecosystem dynamics.

Cost-effectiveness and willing-to-pay thresholds for vertebral augmentation of osteoporotic vertebral fractures, what are they based on: a systematic review.

OBJECTIVE: Although there is substantial clinical evidence on the safety and effectiveness of vertebral augmentation for osteoporotic vertebral fractures, cost-effectiveness is less well known. The objective of this study is to provide a systematic review of cost-effectiveness studies and policy-based willingness-to-pay (WTP) thresholds for different vertebral augmentation (VA) procedures, vertebroplasty (VP) and balloon kyphoplasty (BK), for osteoporotic vertebral fractures (OVFs). DESIGN: A systematic review targeting cost-effectiveness studies of VA procedures for OVFs. DATA SOURCES: Six bibliographic databases were searched from inception up to May 2021. ELIGIBILITY CRITERIA FOR STUDY SELECTION: Studies were eligible if meeting all predefined criteria: (1) VP or BK intervention, (2) OVFs and (3) cost-effectiveness study. Articles not written in English, abstracts, editorials, reviews and those reporting only cost data were excluded. DATA EXTRACTION AND SYNTHESIS: Information was extracted on study characteristics, cost-effective estimates, summary decisions and payer WTP thresholds. Incremental cost-effective ratio (ICER) was the main outcome measure. Studies were summarised by a structured narrative synthesis organised by comparisons with conservative management (CM). Two independent reviewers assessed the quality (risk of bias) of the systematic review and cost-effectiveness studies by peer-reviewed checklists. RESULTS: We identified 520 references through database searching and 501 were excluded as ineligible by titles and abstract. Ten reports were identified as eligible from 19 full-text reviews. ICER for VP versus CM evaluated as cost per quality-adjusted life-year (QALY) ranged from €22 685 (*US$33 395) in Netherlands to £-2240 (*US$-3273), a cost-saving in the UK. ICERs for BK versus CM ranged from £2706 (*US$3954) in UK to kr600 000 (*US$90 910) in Sweden. ICERs were within payer WTP thresholds for a QALY based on historical benchmarks. CONCLUSIONS: Both VP and BK were judged cost-effective alternatives to CM for OVFs in economic studies and were within WTP thresholds in multiple healthcare settings.

Chromatin regulators in the TBX1 network confer risk for conotruncal heart defects in 22q11.2DS.

Congenital heart disease (CHD) affecting the conotruncal region of the heart, occurs in 40-50% of patients with 22q11.2 deletion syndrome (22q11.2DS). This syndrome is a rare disorder with relative genetic homogeneity that can facilitate identification of genetic modifiers. Haploinsufficiency of TBX1, encoding a T-box transcription factor, is one of the main genes responsible for the etiology of the syndrome. We suggest that genetic modifiers of conotruncal defects in patients with 22q11.2DS may be in the TBX1 gene network. To identify genetic modifiers, we analyzed rare, predicted damaging variants in whole genome sequence of 456 cases with conotruncal defects and 537 controls, with 22q11.2DS. We then performed gene set approaches and identified chromatin regulatory genes as modifiers. Chromatin genes with recurrent damaging variants include EP400, KAT6A, KMT2C, KMT2D, NSD1, CHD7 and PHF21A. In total, we identified 37 chromatin regulatory genes, that may increase risk for conotruncal heart defects in 8.5% of 22q11.2DS cases. Many of these genes were identified as risk factors for sporadic CHD in the general population. These genes are co-expressed in cardiac progenitor cells with TBX1, suggesting that they may be in the same genetic network. The genes KAT6A, KMT2C, CHD7 and EZH2, have been previously shown to genetically interact with TBX1 in mouse models. Our findings indicate that disturbance of chromatin regulatory genes impact the TBX1 gene network serving as genetic modifiers of 22q11.2DS and sporadic CHD, suggesting that there are some shared mechanisms involving the TBX1 gene network in the etiology of CHD.

A Novel Tissue Preservation and Transport Solution as a Substitute for Formalin.

Formalin, a common laboratory fixative, is a type 1 carcinogen; a biohazard with risks, environmental, disposal, and legal costs; and a chemical modifier of protein epitopes in tissues. A less-toxic tissue preservation method is therefore badly needed. We have developed a novel tissue preservation medium, Amber, composed of low-potassium dextran glucose, 10% honey, and 1% coconut oil. This study investigates Amber as compared with formalin with respect to the following aspects: (1) histologic preservation, (2) epitope integrity with immunohistochemistry (IHC) and immunofluorescence (IF), and (3) integrity of tissue RNA. Rat and human lung, liver, kidney, and heart tissues were collected and stored for 24 hours at 4 °C in Amber or formalin. The tissues were evaluated with hematoxylin and eosin; IHC: thyroid transcription factor, muscle-specific actin, hepatocyte-specific antigen, and common acute lymphoblastic leukemia antigen; and IF: VE-cadherin, vimentin, and muscle-specific actin. RNA quality upon extraction was also assessed. Amber demonstrated superior and/or noninferior performance in rat and human tissue evaluation with respect to standard techniques of histology, IHC, IF, and extracted RNA quality. Amber maintains high-quality morphology without compromising the ability to perform IHC and nucleic acid extraction. As such, Amber could be a safer and superior substitute to formalin for clinical tissue preservation for contemporary pathological examination.

Role of Antioxidant Vitamins and Other Micronutrients on Regulations of Specific Genes and Signaling Pathways in the Prevention and Treatment of Cancer.

Cancer is an escalating global issue, with 19.3 million new cases and 9.9 million deaths in 2020. Therefore, effective approaches to prevent cancer are urgently required. Diet plays a significant role in determining cancer risk. Nutrients and food bioactives influence specific signaling pathways in the body. Recently, there have been significant advances in cancer prevention research through nutrigenomics or with the effects of dietary components on the genome. Google Scholar, PubMed, and Scopus databases were used to search for peer-reviewed articles between 2017 and 2023. Criteria used were vitamins, minerals, tumors, cancer, genes, inflammation, signaling pathways, and nutrigenomics. Among the total of 1857 articles available, the highest relevant 90 articles that specifically discussed signaling pathways and genes on cancer cell lines and human cancer patients were selected and reviewed. Food sources are rich in antioxidant micronutrients, which are effective in activating or regulating signaling pathways involved in pathogenesis and cancer therapy by activating enzymes such as mitogen-activated protein kinase (MAPK), protein kinase C (PKC), and phosphatidylinositol 3-kinase (PI3K). The micronutrients are involved in the regulation of ß-catenin (WNT/ß-catenin) including mutations in Kras and epidermal growth factor receptor (EGFR) alongside inhibition of the NF-kB pathway. The most common mechanism of cancer prevention by these micronutrients is their antioxidative, anti-inflammation, and anti-apoptosis effects. This review discusses how nutrigenomics is essential and beneficial for developing cancer prevention and treatment approaches.

The Acute Effect of Multi-Ingredient Antioxidant Supplementation following Ionizing Radiation.

Radiation exposure is an undeniable health threat encountered in various occupations and procedures. High energy waves in ionizing radiation cause DNA damage and induce reactive oxygen species (ROS) production, which further exacerbate DNA, protein, and lipid damage, increasing risk of mutations. Although endogenous antioxidants such as superoxide dismutase have evolved to upregulate and neutralize ROS, exogenous dietary antioxidants also have the potential to combat ionizing radiation (IR)-induced ROS production. We evaluated a cocktail of ingredients (AOX) purported to have antioxidant and mitochondrial protective properties on the acute effects of IR. We show that IR stimulates DNA damage through phosphorylation of DNA repair proteins in the heart, brain, and liver of mice. AOX showed partial protection in brain and liver, through a lack of significant activation in given repair proteins. In addition, AOX attenuated the IR-induced increase in NF-kß mRNA and protein expression in brain and liver. Lastly, cytochrome c oxidase complex transcripts were significantly higher in heart and brain following radiation, which was also diminished by prior ingestion of AOX. Together, our findings suggest that a multi-ingredient AOX supplement may attenuate the IR-induced cellular damage response and represents a feasible and cost-effective preventative supplement for at-risk populations of radiation exposure.

Lead-Dust Contamination on Radiation Protection Apparel.

PURPOSE: To evaluate the prevalence of surface lead-dust contamination on radiation protection apparel (RPAs) in the radiology department and compare findings with those from other studies of RPA lead-dust contamination. MATERIALS AND METHODS: A survey of RPAs was conducted between June and December 2021 in radiology departments at a tertiary-care university hospital. A convenience sample of RPAs located on wall-mounted racks outside the angiography suite and emergency department was surveyed. Surface lead dust on RPAs was detected using a rapid qualitative test. RESULTS: A total of 69 RPAs included full-length frontal lead aprons (n = 11), full-length frontal lead aprons (n = 25) with thyroid collars (n = 25), and thyroid collars alone (n = 8). Garments consisted mainly of a lead/antimony composite core with a 0.5-mm lead equivalency. One RPA failed radiologic quality inspection, and 8 garments were in poor or worn condition. The overall prevalence of surface lead-dust contamination on RPAs was 60.9% (95% CI, 49.1%-71.5%) and was significantly (P = .0035) higher on thyroid collars (78.8% [95% CI, 62.2%-89.3%]) than on lead aprons (44.4% [95% CI, 29.5%-60.4%]). CONCLUSIONS: A high prevalence of surface lead-dust contamination was detected on RPAs using a rapid qualitative test. There is currently no established safe level of lead, and these findings suggest RPAs be monitored frequently not only for physical defects limiting radiation protection but also for lead-dust contamination.

One year of psychiatric presentations to a hospital emergency department during COVID-19.

OBJECTIVES: To examine the impact of the first full year of the COVID-19 pandemic and its associated restrictions on the volume and nature of psychiatric presentations to an emergency department (ED) in a large academic hospital. METHODS: Anonymised clinical data on psychiatric presentations to the ED were collected for the 52-week period from the start of the COVID-19 pandemic and compared with corresponding 1 year periods in 2019 and 2018. RESULTS: There was a significant increase in psychiatric presentations overall to the ED during the first year of the COVID-19 pandemic compared to previous years, in contrast to a reduction in total presentations for all other specialties. There was a marked increase in psychiatric presentations of those below 18 years, and in the 30-39 years and 40-49 years age groups, but a decrease in the 18-29 years group. There was a significant increase in anxiety disorder presentations but a decrease in alcohol related presentations. There was no significant change observed in the rates of presentations for self-harm or suicidal ideation. CONCLUSIONS: Psychiatric presentations to the ED have increased during the first year of the COVID-19 pandemic in contrast to a decrease in presentations for other medical specialties, with this increase being driven by out-of-hours presentations. The fourfold increase in presentations of young people below the age of 18 years to the ED with mental health difficulties is an important finding and suggests a disproportionate burden of psychological strain placed on this group during the pandemic.

(Epi)genomic adaptation driven by fine geographical scale environmental heterogeneity after recent biological invasions.

Elucidating processes and mechanisms involved in rapid local adaptation to varied environments is a poorly understood but crucial component in management of invasive species. Recent studies have proposed that genetic and epigenetic variation could both contribute to ecological adaptation, yet it remains unclear on the interplay between these two components underpinning rapid adaptation in wild animal populations. To assess their respective contributions to local adaptation, we explored epigenomic and genomic responses to environmental heterogeneity in eight recently colonized ascidian (Ciona intestinalis) populations at a relatively fine geographical scale. Based on MethylRADseq data, we detected strong patterns of local environment-driven DNA methylation divergence among populations, significant epigenetic isolation by environment (IBE), and a large number of local environment-associated epigenetic loci. Meanwhile, multiple genetic analyses based on single nucleotide polymorphisms (SNPs) showed genomic footprints of divergent selection. In addition, for five genetically similar populations, we detected significant methylation divergence and local environment-driven methylation patterns, indicating the strong effects of local environments on epigenetic variation. From a functional perspective, a majority of functional genes, Gene Ontology (GO) terms, and biological pathways were largely specific to one of these two types of variation, suggesting partial independence between epigenetic and genetic adaptation. The methylation quantitative trait loci (mQTL) analysis showed that the genetic variation explained only 18.67% of methylation variation, further confirming the autonomous relationship between these two types of variation. Altogether, we highlight the complementary interplay of genetic and epigenetic variation involved in local adaptation, which may jointly promote populations' rapid adaptive capacity and successful invasions in different environments. The findings here provide valuable insights into interactions between invaders and local environments to allow invasive species to rapidly spread, thus contributing to better prediction of invasion success and development of management strategies.

A Dietary Antioxidant Formulation Ameliorates DNA Damage Caused by γ-Irradiation in Normal Human Bronchial Epithelial Cells In Vitro.

Antioxidants can be used as radioprotectants to reduce DNA damage due to exposure to radiation that could result in malignancies, including lung cancer. Mortality rates are consistently higher in lung cancer, which is usually diagnosed at later stages of cancer development and progression. In this preliminary study, we examined the potential of an antioxidant formulation (AOX2) to reduce DNA damage using a cell model of human normal bronchial epithelial cells (BEAS-2B). Cells were exposed to γ-irradiation or smoke-related hydrocarbon 4[(acetoxymethyl)nitrosamino]-1 (3-pyridyl) 1-butanone (NNKOAc) to induce DNA damage. We monitored intracellular reactive oxygen species (ROS) levels and evidence of genotoxic damage including DNA fragmentation ELISA, γ-H2AX immunofluorescence, and comet assays. Pre-incubation of the cells with AOX2 before exposure to γ-irradiation and NNKOAc significantly reduced DNA damage. The dietary antioxidant preparation AOX2 significantly reduced the induction of the tumor suppressor protein p53 and DNA damage-associated γ-H2AX phosphorylation by radiation and the NNKOAc treatment. Thus, AOX2 has the potential to act as a chemoprotectant by lowering ROS levels and DNA damage caused by exposure to radiation or chemical carcinogens.

Ecological Review of the Ciona Species Complex.

AbstractThe set of four closely related solitary ascidians Ciona spp. were once considered a single cosmopolitan species, Ciona intestinalis, but are now recognized as genetically and morphologically distinct species. The possibility of ecological differences between the species was not widely considered in studies preceding the schism of Ciona spp. Consequently, there may be an over-generalization of the ecology of Ciona spp., with potential implications for the broad range of studies targeting these species, encompassing the evolution, development, genomics, and invasion biology of Ciona spp. We completed a comprehensive review of the ecology of Ciona spp. to establish the similarities and differences between the widely distributed Ciona robusta and C. intestinalis (and what little is known of the two other species, Ciona sp. C and Ciona sp. D). When necessary, we used study locations and the species' geographic ranges to infer the species in each study in the review. As expected, ecological similarities are the norm between the two species, spanning both abiotic and biotic interactions. However, there are also important differences that have potential implications for other aspects of the biology of Ciona spp. For example, differences in temperature and salinity tolerances likely correspond with the disparities in the geographic distribution of the species. Asymmetries in topics studied in each species diminish our ability to fully compare several aspects of the ecology of Ciona spp. and are priority areas for future research. We anticipate that our clarification of common and unique aspects of each species' ecology will help to provide context for future research in many aspects of the biology of Ciona spp.

Cost-effectiveness studies of vertebral augmentation for osteoporotic vertebral fractures: a systematic review.

BACKGROUND CONTEXT: Osteoporotic vertebral fractures (OVF) dramatically increase with age and are serious life altering adverse events for seniors resulting in increased rates of institutionalization, morbidity and mortality. Given the expanding population of the elderly and increasing prevalence of OVFs, cost-effective treatment strategies need to be considered. Percutaneous vertebral augmentation (VA) procedures such as vertebroplasty (VP) or balloon kyphoplasty (BK) are increasingly employed to treat painful vertebral fractures not responding to conservative management (CM) of bedrest and analgesia. Both VA procedures have been shown to be effective treatments for OVFs in multiple systematic reviews of randomized controlled trials. In this systematic review, analytical strategies, designs and results were compared for health economic studies evaluating cost-effectiveness of VA procedures, VP or BK for OVFs. Furthermore, assessments of quality (risk of bias) were conducted for the systematic review and the individual studies with peer-reviewed checklists recommended for cost-effectiveness studies. PURPOSE: To provide an up-to-date systematic review of peer-reviewed studies evaluating cost-effectiveness of VA procedures, VP or KP for OVFs to support treatment and health care funding decisions. STUDY DESIGN: This study is a systematic literature review and structured narrative synthesis. STUDY SAMPLE: Peer reviewed health economic studies reporting cost-effectiveness for VA procedures, VP or BK for OVFs OUTCOME MEASURES: The following information extracted from the studies included: report country and year, study design, comparators, population, perspective, health valuations, costing sources and cost-effectiveness measures. For economic studies involving modeling, information was also extracted for model type, time horizon, key model drivers, and handling of uncertainty. Incremental cost-effectiveness ratio (ICER), the ratio of differences between comparator treatment groups in costs and health benefits, was considered the main cost-effectiveness measure. METHODS: A systematic review was conducted of MEDLINE, EMBASE, CINAHL, ECONLIT, Cochrane Library and DARE databases up to the review date May 2021. Studies were reviewed for those reporting cost-effectiveness analyses on VA procedures including VP or BK for OVFs. Studies including only costs, abstracts, editorials, methodologies and reviews were not included. The selection of articles was reported in line with PRISMA guidance. A descriptive framework was developed to classify types of cost-effectiveness studies based on methodological differences and a structured narrative synthesis was used to summarize studies. Quality assessments were made with British Medical Journal checklist for individual cost-effectiveness studies and the CiCERO checklist for systematic reviews of cost-effectiveness studies. RESULTS: In this systematic review, 520 references were identified through database searching and 501 were excluded as ineligible by titles and abstract based on prior eligibility criteria. From full-text reviews of 19 reports, ten were identified as eligible for the systematic review evaluating cost-effectiveness of VA procedures for OVFs. All references were published between 2008 and 2020. The ten cost-effectiveness studies, three for VP, three for BK and four for both VP and BK, all involved CM for OVFs as a treatment comparator. The studies involved different methods of economic analysis, modeling assumptions, cost and health valuations conducted in different health care setting over different time periods. A framework for the review outlines key features of cost-effectiveness study designs consisting of unmatched, matched, or randomized controls involving cost-effectiveness or cost-utility) analyses. Both VP and BK were cost-effective alternatives to CM for OVFs with earlier health gains and significantly shorter hospital stays. Cost-effectiveness estimates, ICERs, remained relatively stable and within willingness-to-pay thresholds under a range of sensitivity analyses. Comparisons between VP and BK were variable depending on modeling assumptions, but generally the procedures had similar health benefit gains with VP having lower acute procedural costs. CONCLUSIONS: Both VP and BK, have been shown to be cost-effective alternatives to CM for osteoporotic vertebral fractures in diverse cost-effectiveness studies conducted in multiple health care settings. Trial-based cost-utility contributed the strongest evidence supporting cost-effectiveness determination for VP and BK for OVFs.

Tuning the mechanical impedance of disordered networks for impact mitigation.

Disordered-Network Mechanical Materials (DNMM), comprised of random arrangements of bonds and nodes, have emerged as mechanical metamaterials with the potential for achieving fine control over their mechanical properties. Recent computational studies have demonstrated this control whereby an extremely high degree of mechanical tunability can be achieved in disordered networks via a selective bond removal process called pruning. In this study, we experimentally demonstrate how pruning of a disordered network alters its macroscopic dynamic mechanical response and its capacity to mitigate impact. Impact studies with velocities ranging from 0.1 m s-1 to 1.5 m s-1 were performed, using a mechanical impactor and a drop tower, on 3D printed pruned and unpruned networks comprised of materials spanning a range of stiffness. High-speed videography was used to quantify the changes in Poisson's ratio for each of the network samples. Our results demonstrate that pruning is an efficient way to reduce the transmitted force and impulse from impact in the medium strain rate regime (101 s-1 to 102 s-1). This approach provides an interesting alternative route for designing materials with tailored impact mitigating properties compared to random material removal based on open cell foams.