Analysing a mechanism of failure in retrieved magnetically controlled spinal rods

PURPOSE: We aim to describe a mechanism of failure in magnetically controlled growth rods which are used for the correction of the early onset scoliosis. METHODS: This retrieval study involved nine magnetically controlled growth rods, of a single design, revised from five patients for metal staining, progression of scoliosis, swelling, fractured actuator pin, and final fusion. All the retrieved rods were radiographed and assessed macroscopically and microscopically for material loss. Two implants were further analysed using micro-CT scanning and then sectioned to allow examination of the internal mechanism. No funding was obtained to analyse these implants. There were no potential conflicts interests. RESULTS: Plain radiographs revealed that three out of nine retrieved rods had a fractured pin. All had evidence of surface degradation on the extendable telescopic rod. There was considerable corrosion along the internal mechanism. CONCLUSIONS: We found that a third of the retrieved magnetically controlled growth rods had failed due to pin fracture secondary to corrosion of the internal mechanism. We recommend that surgeons consider that any inability of magnetically controlled growth rods to distract may be due to corrosive debris building up inside the mechanism, thereby preventing normal function

Characteristics of Patients Presenting at an Emergency Department for a Heroin Overdose vs Detoxification

Kenneth E Leonard,1 Joshua J Lynch,2 Florence W Leong,3 Daniel J Kruger,2 Brian M Clemency2 1Department of Psychiatry and Clinical and Research Institute on Addiction, University at Buffalo, The State University of New York, Buffalo, NY, USA; 2Department of Emergency Medicine and Clinical and Research Institute on Addiction, University at Buffalo, The State University of New York, Buffalo, NY, USA; 3Clinical and Research Institute on Addiction, University at Buffalo, The State University of New York, Buffalo, NY, USACorrespondence: Kenneth E Leonard, Clinical and Research Institute on Addictions, University at Buffalo, 1021 Main Street, Buffalo, NY, 14203, USA, Email [email protected]: This study compares substance use, treatment histories, and sociodemographic characteristics of patients presenting to an emergency department (ED) following a heroin overdose or seeking detoxification services for heroin and examines risk factors for a subsequent return to the ED for a substance-related problem.Methods: A convenience sample of patients presenting for an overdose or detoxification at an urban teaching ED was recruited for this study. During their ED visit, patients were interviewed regarding demographics, substance use experiences, and treatment history. Subsequently, a review of patient records for past and subsequent ED use was performed.Results: Patients requesting detox and those with an overdose were similar in terms of prior treatment. Both groups had similar extensive polysubstance histories. As a group, however, patients presenting for detox were more likely to report use of each of three substances (benzodiazepines, opioid pain medications, and heroin) more than three times per week, compared to those presenting for overdose. Detox patients had higher scores on the 3-item Alcohol Use Disorder Identification Test-C and the drug problems scale compared to overdose patients. Overall, 28% of the patients returned to the ED within 90 days for a drug-related issue, including 8% that returned for an overdose. Factors predictive of a return ED visit included ED visits for substance use in the previous year and recent frequent heroin use.Conclusion: Patients requesting detox were similar in most domains to those presenting following an overdose. Notably, overdose patients were less likely to use heroin more than three times per week compared to detox patients. Both groups were equally likely to return for an SUD reason within 3-months, however for both groups, previous ED visits and recent frequent heroin use predicted a return visit.Keywords: heroin, overdose, recidivism, detoxificatio

Academic Performance and Behavioral Patterns

Identifying the factors that influence academic performance is an essential part of educational research. Previous studies have documented the importance of personality traits, class attendance, and social network structure. Because most of these analyses were based on a single behavioral aspect and/or small sample sizes, there is currently no quantification of the interplay of these factors. Here, we study the academic performance among a cohort of 538 undergraduate students forming a single, densely connected social network. Our work is based on data collected using smartphones, which the students used as their primary phones for two years. The availability of multi-channel data from a single population allows us to directly compare the explanatory power of individual and social characteristics. We find that the most informative indicators of performance are based on social ties and that network indicators result in better model performance than individual characteristics (including both personality and class attendance). We confirm earlier findings that class attendance is the most important predictor among individual characteristics. Finally, our results suggest the presence of strong homophily and/or peer effects among university students

Comparison of Newtonian and Special-Relativistic Trajectories with the General-Relativistic Trajectory for a Low-Speed Weak-Gravity System

We show, contrary to expectation, that the trajectory predicted by general-relativistic mechanics for a low-speed weak-gravity system is not always well-approximated by the trajectories predicted by special-relativistic and Newtonian mechanics for the same parameters and initial conditions. If the system is dissipative, the breakdown of agreement occurs for chaotic trajectories only. If the system is non-dissipative, the breakdown of agreement occurs for chaotic trajectories and non-chaotic trajectories. The agreement breaks down slowly for non-chaotic trajectories but rapidly for chaotic trajectories. When the predictions are different, general-relativistic mechanics must therefore be used, instead of special-relativistic mechanics (Newtonian mechanics), to correctly study the dynamics of a weak-gravity system (a low-speed weak-gravity system)

Inherent Interfacial Mechanical Gradients in 3D Hydrogels Influence Tumor Cell Behaviors

Cells sense and respond to the rigidity of their microenvironment by altering their morphology and migration behavior. To examine this response, hydrogels with a range of moduli or mechanical gradients have been developed. Here, we show that edge effects inherent in hydrogels supported on rigid substrates also influence cell behavior. A Matrigel hydrogel was supported on a rigid glass substrate, an interface which computational techniques revealed to yield relative stiffening close to the rigid substrate support. To explore the influence of these gradients in 3D, hydrogels of varying Matrigel content were synthesized and the morphology, spreading, actin organization, and migration of glioblastoma multiforme (GBM) tumor cells were examined at the lowest (<50 µm) and highest (>500 µm) gel positions. GBMs adopted bipolar morphologies, displayed actin stress fiber formation, and evidenced fast, mesenchymal migration close to the substrate, whereas away from the interface, they adopted more rounded or ellipsoid morphologies, displayed poor actin architecture, and evidenced slow migration with some amoeboid characteristics. Mechanical gradients produced via edge effects could be observed with other hydrogels and substrates and permit observation of responses to multiple mechanical environments in a single hydrogel. Thus, hydrogel-support edge effects could be used to explore mechanosensitivity in a single 3D hydrogel system and should be considered in 3D hydrogel cell culture systems

Comparative Study of Monoclonal and Recombinant Antibody-Based Immunoassays for Fungicide Analysis in Fruit juices

[EN] A comparative study of the analytical performance of enzyme-linked immunosorbent assays (ELISAs), based on monoclonal and recombinant antibodies, for the determination of fungicide residues in fruit juices has been carried out. To this aim, three murine hybridoma cell lines secreting specific monoclonal antibodies against (RS)-2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl-1,1,2,2-tetrafluoroethyl ether (tetraconazole), 2-(4-triazolyl)benzimidazole (thiabendazole), and (RS)-1-(beta-allyloxy-2,4-dichlorophenylethyl)imidazole (imazalil) were used as a source of immunoglobulin gene fragments for the production of single-chain variable fragment (scFv) and fusion scFv-pIII recombinant antibodies in Escherichia coli. Selected recombinant antibodies displayed cross-reactivity profiles very similar to those of the parent monoclonal antibodies. Imazalil and tetraconazole recombinant antibodies showed one order of magnitude lower affinity than their respective monoclonal antibodies, whereas the thiabendazole recombinant antibodies showed an affinity similar to that of their parent monoclonal antibody. On the other hand, scFv-pIII fusion fragments showed similar analytical properties as, and occasionally better than, scFv recombinant antibodies. Finally, ELISAs developed from each antibody type showed similar analytical performance when applied to the analysis of the target fungicides in fruit juices.This work was funded by Ministerio de Educacion y Ciencia (MEC, Spain, Project AGL2002-03266). E. P. was the recipient of a doctoral fellowship from Conselleria d'Educacio (Generalitat Valenciana, Spain).Moreno Tamarit, MJ.; Plana Andani, E.; Manclus Ciscar, JJ.; Montoya Baides, Á. (2014). Comparative Study of Monoclonal and Recombinant Antibody-Based Immunoassays for Fungicide Analysis in Fruit juices. Food Analytical Methods. 7(2):481-489. https://doi.org/10.1007/s12161-013-9655-zS48148972Abad A, Manclús JJ, Moreno M, Montoya A (2001) J AOAC Int 84:1–6Alcocer MJC, Doyen C, Lee HA, Morgan MRA (2000) J Agric Food Chem 48:4053–4059Brichta J, Vesela H, Franek M (2003) Vet Med 48:237–247Brichta J, Hnilova M, Viskovic T (2005) Vet Med 50:231–252Charlton K, Harris WJ, Potter AJ (2001) Biosens Bioelec 16:639–646EU Pesticide Database (2013) Pesticide EU-MRLs. http://ec.europa.eu/sanco_pesticides/public/index.cfm . Accessed Jan 2013Ferrer C, Martínez-Bueno MJ, Lozano A, Fernández-Alba AR (2011) Talanta 83:1552–1561Garret SD, Appleford DJA, Wyatt GM, Lee HA, Morgan MRA (1997) J Agric Food Chem 45:4183–4189Graham BM, Porter AJ, Harris WJ (1995) J Chem Technol Biotech 63:279–289Hiemstra M, de Kok A (2007) J Chromatog A 1154:3–25Kipriyanov SM, Moldenhauer G, Little M (1997) J Immunol Meth 200:69–77Kramer K, Hock B (2007) Recombinant antibodies for agrochemicals: Evolutionary optimization. In: Kennedy IR, Solomon KR, Gee SJ, Crossan AN, Wang S, Sánchez-Bayo F (eds) Rational environmental management of agrochemicals: Risk assessment, monitoring, and remedial action. ACS Symposium Series, vol. 966, pp 155−170Krebber A, Bornhauser S, Burmester J, Honegger A, Willuda J, Bosshard HR, Plückthun A (1997) J Immunol Meth 201:35–55Leong SSJ, Chen WN (2008) Chem Engin Sci 63:1401–1414Li T, Zhang Q, Liu Y, Chen D, Hu B, Blake DA, Liu F (2006) J Agric Food Chem 54:9085–9091Manclús JJ, Moreno M, Plana E, Montoya A (2008) J Agric Food Chem 56:8790–8800Markus V, Janne L, Urpo L (2011) Trends Anal Chem 30:219–226Mersmann M, Schmidt A, Tesar M, Schöneberg A, Welschof M, Kipriyanov S, Terness P, Little M, Pfizenmaier K, Moosmayer D (1998) J Immunol Meth 220:51–58Moreno M, Plana E, Montoya A, Caputo P, Manclús JJ (2007) Food Addit Contam 24:704–712Morozova VS, Levashova AI, Eremin SA (2005) J Anal Chem 60:202–217Nishi K, Imajuku Y, Nakata M, Ohde K, Miyake S, Morimune K, Kawata M, Ohkawa H (2003) J Pest Sci 28:301–309Nishi K, Ishiuchi M, Morimune K, Ohkawa H (2005) J Agric Food Chem 53:5096–5104Scholthof KB, Whang G, Karu AE (1997) J Agric Food Chem 45:1509–1517Sheedy C, MacKenzie CR, Hall JC (2007) Biotech Adv 25:25333–25352Tout NL, Yau KYF, Trevors JT, Lee H, Hall JC (2001) J Agric Food Chem 49:3628–3637Webb SR, Lee H, Hall JC (1997) J Agric Food Chem 45:535–541Yau KYF, Tout NL, Trevors JT, Lee H, Hall JC (1998) J Agric Food Chem 46:4457–4463Yoshioka N, Akiyama Y, Matsuoka T, Mitsuhashi T (2010) Food Control 21:212–21

Probing charge transfer characteristics in a donor–acceptor metal-organic framework by Raman spectroelectrochemistry and pressure-dependence studies

The stimuli responsive behaviour of charge transfer donor-acceptor metal-organic frameworks (MOFs) remains an understudied phenomenon which may have applications in tuneable electronic materials. We now report the modification of donor-acceptor charge transfer characteristics in a tetrathiafulvalene-naphthalene diimide-based MOF under applied electrochemical bias and pressure. We employ a facile solid state in situ Raman spectroelectrochemical technique, applied for the first time in the characterisation of electroactive MOFs, to monitor the formation of a new complex TTFTC•+–DPNI from a largely neutral system, upon electrochemical oxidation of the framework. In situ pressure-dependent Raman spectroscopy and powder X-ray diffraction experiments performed in a diamond anvil cell revealed blue shifts in the donor and acceptor vibrational modes in addition to contractions in the unit cell which are indicative of bond shortening. This study demonstrates the utility of in situ Raman spectroscopic techniques in the characterisation of redox-active MOFs and the elucidation of their electronic behaviours

Adjuvant and neoadjuvant therapy for gastric cancer using epirubicin/cisplatin/5-fluorouracil (ECF) and alternative regimens before and after chemoradiation

Chemoradiation is now used more commonly for gastric cancer following publication of the US Intergroup trial results that demonstrate an advantage to adjuvant postoperative chemoradiotherapy. However, there remain concerns regarding the toxicity of this treatment, the optimal chemotherapy regimen and the optimal method of radiotherapy delivery. In this prospective study, we evaluated the toxicity and feasibility of an alternative chemoradiation regimen to that used in the Intergroup trial. A total of 26 patients with adenocarcinoma of the stomach were treated with 3D-conformal radiation therapy to a dose of 45 Gy in 25 fractions with concurrent continuous infusional 5-fluorouracil (5-FU). The majority of patients received epirubicin, cisplatin and 5-FU (ECF) as the systemic component given before and after concurrent chemoradiation. The overall rates of observed grade 3 and 4 toxicities were 38 and 15%, respectively. GIT grade 3 toxicity was observed in 19% of patients, while haematologic grade 3 and 4 toxicities were observed in 23%. Our results suggest that this adjuvant regimen can be delivered safely and with acceptable toxicity. This regimen forms the basis of several new studies being developed for postoperative adjuvant therapy of gastric cancer

Role of Right Ventricular Global Longitudinal Strain in Predicting Early and Long-Term Mortality in Cardiac Resynchronization Therapy Patients.

BACKGROUND: Right ventricular (RV) dysfunction has been associated with poor prognosis in chronic heart failure (HF). However, less data is available about the role of RV dysfunction in patients with cardiac resynchronization therapy (CRT). We aimed to investigate if RV dysfunction would predict outcome in CRT. DESIGN: We enrolled prospectively ninety-three consecutive HF patients in this single center observational study. All patients underwent clinical evaluation and echocardiography before CRT and 6 months after implantation. We assessed RV geometry and function by using speckle tracking imaging and calculated strain parameters. We performed multivariable Cox regression models to test mortality at 6 months and at 24 months. RESULTS: RV dysfunction, characterized by decreased RVGLS (RV global longitudinal strain) [10.2 (7.0-12.8) vs. 19.5 (15.0-23.9) %, p<0.0001] and RVFWS (RV free wall strain) [15.6 (10.0-19.3) vs. 17.4 (10.5-22.2) %, p = 0.04], improved 6 months after CRT implantation. Increasing baseline RVGLS and RVFWS predicted survival independent of other parameters at 6 months [hazard ratio (HR) = 0.37 (0.15-0.90), p = 0.02 and HR = 0.42 (0.19-0.89), p = 0.02; per 1 standard deviation increase, respectively]. RVGLS proved to be a significant independent predictor of mortality at 24 months [HR = 0.53 (0.32-0.86), p = 0.01], and RVFWS showed a strong tendency [HR = 0.64 (0.40-1.00), p = 0.05]. The 24-month survival was significantly impaired in patients with RVGLS below 10.04% before CRT implantation [area under the curve = 0.72 (0.60-0.84), p = 0.002, log-rank p = 0.0008; HR = 5.23 (1.76-15.48), p = 0.003]. CONCLUSIONS: Our findings indicate that baseline RV dysfunction is associated with poor short-term and long-term prognosis after CRT implantation

Brane-World Gravity

The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+\textit{d}-dimensional spacetime (the "bulk"), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the \textit{d} extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak ($\sim$ TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity "leaks" into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall--Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at \emph{low} energies -- the 5-dimensional Dvali--Gabadadze--Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.Comment: A major update of Living Reviews in Relativity 7:7 (2004) "Brane-World Gravity", 119 pages, 28 figures, the update contains new material on RS perturbations, including full numerical solutions of gravitational waves and scalar perturbations, on DGP models, and also on 6D models. A published version in Living Reviews in Relativit