The epidemiology of hematogenous vertebral osteomyelitis: a cohort study in a tertiary care hospital

<p>Abstract</p> <p>Background</p> <p>Vertebral osteomyelitis is a common manifestation of osteomyelitis in adults and associated with considerable morbidity. Limited data exist regarding hematogenous vertebral osteomyelitis. Our objective was to describe the epidemiology and management of hematogenous vertebral osteomyelitis.</p> <p>Methods</p> <p>We performed a 2-year retrospective cohort study of adult patients with hematogenous vertebral osteomyelitis at a tertiary care hospital.</p> <p>Results</p> <p>Seventy patients with hematogenous vertebral osteomyelitis were identified. The mean age was 59.7 years (±15.0) and 38 (54%) were male. Common comorbidities included diabetes (43%) and renal insufficiency (24%). Predisposing factors in the 30 days prior to admission included bacteremia (19%), skin/soft tissue infection (17%), and having an indwelling catheter (30%). Back pain was the most common symptom (87%). Seven (10%) patients presented with paraplegia. Among the 46 (66%) patients with a microbiological diagnosis, the most common organisms were methicillin-susceptible <it>S. aureus </it>[15 (33%) cases], and methicillin-resistant <it>S. aureus </it>[10 (22%)]. Among the 44 (63%) patients who had a diagnostic biopsy, open biopsy was more likely to result in pathogen recovery [14 (93%) of 15 with open biopsy vs. 14 (48%) of 29 with needle biopsy; p = 0.003]. Sixteen (23%) patients required surgical intervention for therapeutic purposes during admission.</p> <p>Conclusions</p> <p>This is one of the largest series of hematogenous vertebral osteomyelitis. A microbiological diagnosis was made in only approximately two-thirds of cases. <it>S. aureus </it>was the most common causative organism, of which almost half the isolates were methicillin-resistant.</p

Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system

What are the consequences of combining nuclear and mitochondrial data for phylogenetic analysis? Lessons from Plethodon salamanders and 13 other vertebrate clades

<p>Abstract</p> <p>Background</p> <p>The use of mitochondrial DNA data in phylogenetics is controversial, yet studies that combine mitochondrial and nuclear DNA data (mtDNA and nucDNA) to estimate phylogeny are common, especially in vertebrates. Surprisingly, the consequences of combining these data types are largely unexplored, and many fundamental questions remain unaddressed in the literature. For example, how much do trees from mtDNA and nucDNA differ? How are topological conflicts between these data types typically resolved in the combined-data tree? What determines whether a node will be resolved in favor of mtDNA or nucDNA, and are there any generalities that can be made regarding resolution of mtDNA-nucDNA conflicts in combined-data trees? Here, we address these and related questions using new and published nucDNA and mtDNA data for <it>Plethodon </it>salamanders and published data from 13 other vertebrate clades (including fish, frogs, lizards, birds, turtles, and mammals).</p> <p>Results</p> <p>We find widespread discordance between trees from mtDNA and nucDNA (30-70% of nodes disagree per clade), but this discordance is typically not strongly supported. Despite often having larger numbers of variable characters, mtDNA data do not typically dominate combined-data analyses, and combined-data trees often share more nodes with trees from nucDNA alone. There is no relationship between the proportion of nodes shared between combined-data and mtDNA trees and relative numbers of variable characters or levels of homoplasy in the mtDNA and nucDNA data sets. Congruence between trees from mtDNA and nucDNA is higher on branches that are longer and deeper in the combined-data tree, but whether a conflicting node will be resolved in favor mtDNA or nucDNA is unrelated to branch length. Conflicts that are resolved in favor of nucDNA tend to occur at deeper nodes in the combined-data tree. In contrast to these overall trends, we find that <it>Plethodon </it>have an unusually large number of strongly supported conflicts between data types, which are generally resolved in favor of mtDNA in the combined-data tree (despite the large number of nuclear loci sampled).</p> <p>Conclusions</p> <p>Overall, our results from 14 vertebrate clades show that combined-data analyses are not necessarily dominated by the more variable mtDNA data sets. However, given cases like <it>Plethodon</it>, there is also the need for routine checking of incongruence between mtDNA and nucDNA data and its impacts on combined-data analyses.</p

Pressure-tuned spin and charge ordering in an itinerant antiferromagnet

Elemental chromium orders antiferromagnetically near room temperature, but the ordering temperature can be driven to zero by applying large pressures. We combine diamond anvil cell and synchrotron x-ray diffraction techniques to measure directly the spin and charge order in the pure metal at the approach to its quantum critical point. Both spin and charge order are suppressed exponentially with pressure, well beyond the region where disorder cuts off such a simple evolution, and they maintain a harmonic scaling relationship over decades in scattering intensity. By comparing the development of the order parameter with that of the magnetic wave vector, it is possible to ascribe the destruction of antiferromagnetism to the growth in electron kinetic energy relative to the underlying magnetic exchange interaction

Perceptions of change in the environment caused by the COVID-19 pandemic: implications for environmental policy

COVID-19 lockdown measures have impacted the environment with both positive and negative effects. However, how human populations have perceived such changes in the natural environment and how they may have changed their daily habits have not been yet thoroughly evaluated. The objectives of this work were to investigate (1) the social perception of the environmental changes produced by the COVID-19 pandemic lockdown and the derived change in habits in relation to i) waste management, energy saving, and sustainable consumption, ii) mobility, iii) social inequalities, iv) generation of noise, v) utilization of natural spaces, and, vi) human population perception towards the future, and (2) the associations of these potential new habits with various socio-demographic variables. First, a SWOT analysis identified strengths (S), weaknesses (W), opportunities (O), and threats (T) generated by the pandemic lockdown measures. Second, a survey based on the aspects of the SWOT was administered among 2370 adults from 37 countries during the period from February to September 2021. We found that the short-term positive impacts on the natural environment were generally well recognized. In contrast, longer-term negative effects arise, but they were often not reported by the survey participants, such as greater production of plastic waste derived from health safety measures, and the increase in e-commerce use, which can displace small storefront businesses. We were able to capture a mismatch between perceptions and the reported data related to visits to natural areas, and generation of waste. We found that age and country of residence were major contributors in shaping the survey participants ´answers, which highlights the importance of government management strategies to address current and future environmental problems. Enhanced positive perceptions of the environment and ecosystems, combined with the understanding that livelihood sustainability, needs to be prioritized and would reinforce environmental protection policies to create greener cities. Moreover, new sustainable jobs in combination with more sustainable human habits represent an opportunity to reinforce environmental policy

Technical and vocational education and training (TVET) for young people in low- and middle-income countries: a systematic review and meta-analysis

The world is facing a worsening youth employment crisis. In response, technical and vocational education and training (TVET) is back on the development agenda after years of neglect. This systematic review examined the evidence from studies evaluating the impacts of TVET interventions for young people in low- and middle-income countries (LMICs). The 26 included studies evaluated 20 different interventions, predominantly from Latin America. Meta-analyses of the effectiveness of TVET on five outcome measure categories were conducted. The overall mean effects on overall paid employment, formal employment, and monthly earnings were small, positive, and significant; however, significant heterogeneity was observed. Moderator analysis was performed in an attempt to explain between-study differences in effects. The overall paucity of research in this area, together with specific gaps and methodological limitations, affirm the need for strengthening the evidence base. Implications for policy, practice and research are discussed

Computational investigation of diesel nozzle internal flow during the complete injection event

[EN] Currently, diesel engines are calibrated using more and more complex multiple injection strategies. Under these conditions, the characteristics of the flow exiting the fuel injector are strongly affected by the transient interaction between the needle, the sac volume and the orifices, which are not yet clear. In the current paper, a methodology combining a 1D injector model and 3D-CFD simulations is proposed. First, the characteristics of the nozzle flow have been experimentally assessed in transient conditions by means of injection rate and momentum flux measurements. Later, the 3D-CFD modeling approach has been validated at steady-state fixed lift conditions. Finally, a previously developed 1D injector model has been used to extract the needle lift profiles and transient pressure boundary conditions used for the full-transient 3D-CFD simulations, using adaptive mesh refinement (AMR) strategies to be able to simulate the complete injection rate starting from 1 mu m lift.This work was partly sponsored by "Ministerio de Economia y Competitividad'', of the Spanish Government, in the frame of the Project "Estudio de la interaccion chorro-pared en condiciones realistas de motor'', Reference TRA2015-67679-c2-1-R. The authors would like also to thank the computer resources, technical expertise and assistance provided by Universidad de Valencia in the use of the supercomputer "Tirant''. Mr. Jaramillo's Thesis is funded by "Conselleria d'Educacio, Cultura i Esports'' of Generalitat Valenciana in the frame of the program "Programa VALI + D para investigadores en formacion, Reference ACIF/2015/040.Salvador, FJ.; De La Morena, J.; Bracho Leon, G.; Jaramillo-Císcar, D. (2018). Computational investigation of diesel nozzle internal flow during the complete injection event. Journal of the Brazilian Society of Mechanical Sciences and Engineering. 40(3):153-167. https://doi.org/10.1007/s40430-018-1074-zS153167403Hall CAS, Lambert JG, Balogh SB (2014) EROI of different fuels and the implications for society. Energy Policy 64:141–152. https://doi.org/10.1016/j.enpol.2013.05.049Lujan JM, Tormos B, Salvador FJ, Gargar K (2009) Comparative analysis of a DI diesel engine fuelled with biodiesel blends during the European MVEG-A cycle: preliminary study (I). Biomass Bioenergy 33:941–947. https://doi.org/10.1016/j.biombioe.2009.02.004Pickett LM, Siebers DL (2004) Soot in diesel fuel jets: effects of ambient temperature, ambient density, and injection pressure. Combust Flame 138:114–135. https://doi.org/10.1016/j.combustflame.2004.04.006Dec JE (1997) A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging. SAE Tech. Pap. 970873Wang X, Huang Z, Zhang W et al (2011) Effects of ultra-high injection pressure and micro-hole nozzle on flame structure and soot formation of impinging diesel spray. Appl Energy 88:1620–1628. https://doi.org/10.1016/j.apenergy.2010.11.035Sayin C, Gumus M, Canakci M (2013) Influence of injector hole number on the performance and emissions of a di diesel engine fueled with biodiesel-diesel fuel blends. Appl Therm Eng 61:121–128. https://doi.org/10.1016/j.applthermaleng.2013.07.038Mohan B, Yang W, Chou SK (2013) Fuel injection strategies for performance improvement and emissions reduction in compression ignition engines—A review. Renew Sustain Energy Rev 28:664–676. https://doi.org/10.1016/j.rser.2013.08.051Payri R, Salvador FJ, Gimeno J, De la Morena J (2011) Influence of injector technology on injection and combustion development, Part 1: hydraulic characterization. Appl Energy 88:1068–1074. https://doi.org/10.1016/j.apenergy.2010.10.012Park SW, Kim JW, Lee CS (2006) Effect of injector type on fuel-air mixture formation of high-speed diesel sprays. Proc Inst Mech Eng D 220:647–659. https://doi.org/10.1243/09544070D20304Moon S, Komada K, Sato K et al (2015) Ultrafast X-ray study of multi-hole GDI injector sprays: effects of nozzle hole length and number on initial spray formation. Exp Therm Fluid Sci 68:68–81. https://doi.org/10.1016/j.expthermflusci.2015.03.027Powell CF, Kastengren AL, Liu Z, Fezzaa K (2010) The effects of diesel injector needle motion on spray structure. J Eng Gas Turbines Power 133:12802. https://doi.org/10.1115/1.4001073Huang W, Moon S, Ohsawa K (2016) Near-nozzle dynamics of diesel spray under varied needle lifts and its prediction using analytical model. Fuel 180:292–300. https://doi.org/10.1016/j.fuel.2016.04.042Sun Z-Y, Li G-X, Chen C et al (2015) Numerical investigation on effects of nozzle’s geometric parameters on the flow and the cavitation characteristics within injector’s nozzle for a high-pressure common-rail DI diesel engine. Energy Convers Manag 89:843–861. https://doi.org/10.1016/j.enconman.2014.10.047Devassy BM, Habchi C, Daniel E (2015) Atomization modelling of liquid jets using a two-surface density approach. At Sprays 25:47–80Moon S, Gao Y, Park S et al (2015) Effect of the number and position of nozzle holes on in- and near-nozzle dynamic characteristics of diesel injection. Fuel 150:112–122. https://doi.org/10.1016/j.fuel.2015.01.097Payri R, Salvador FJ, Carreres M, De la Morena J (2016) Fuel temperature influence on the performance of a last generation common-rail diesel ballistic injector. Part II: 1D model development, validation and analysis. Energy Convers Manag 114:376–391. https://doi.org/10.1016/j.enconman.2016.02.043Plamondon E, Seers P (2014) Development of a simplified dynamic model for a piezoelectric injector using multiple injection strategies with biodiesel/diesel-fuel blends. Appl Energy 131:411–424. https://doi.org/10.1016/j.apenergy.2014.06.039Postrioti L, Malaguti S, Bosi M et al (2014) Experimental and numerical characterization of a direct solenoid actuation injector for diesel engine applications. Fuel 118:316–328. https://doi.org/10.1016/j.fuel.2013.11.001Desantes JM, Salvador FJ, Lopez JJ, De la Morena J (2011) Study of mass and momentum transfer in diesel sprays based on X-ray mass distribution measurements and on a theoretical derivation. Exp Fluids 50:233–246. https://doi.org/10.1007/s00348-010-0919-8De la Morena J, Neroorkar K, Plazas AH et al (2013) Numerical analysis of the influence of diesel nozzle design on internal flow characteristics for 2-valve diesel engine application. At Sprays 23:97–118. https://doi.org/10.1615/AtomizSpr.2013006361Duke DJ, Schmidt DP, Neroorkar K et al (2013) High-resolution large eddy simulations of cavitating gasoline-ethanol blends. Int J Engine Res 14:578–589. https://doi.org/10.1177/1468087413501824Mitroglou N, McLorn M, Gavaises M et al (2014) Instantaneous and ensemble average cavitation structures in diesel micro-channel flow orifices. Fuel 116:736–742. https://doi.org/10.1016/j.fuel.2013.08.060Wang X, Li K, Su W (2012) Experimental and numerical investigations on internal flow characteristics of diesel nozzle under real fuel injection conditions. Exp Therm Fluid Sci 42:204–211. https://doi.org/10.1016/j.expthermflusci.2012.04.022Sou A, Pratama RH (2016) Effects of asymmetric inflow on cavitation in fuel injector and discharged liquid jet. At Sprays 26:939–959. https://doi.org/10.1615/AtomizSpr.2015013501Xue Q, Battistoni M, Powell CF et al (2015) An Eulerian CFD model and X-ray radiography for coupled nozzle flow and spray in internal combustion engines. Int J Multiph Flow 70:77–88. https://doi.org/10.1016/j.ijmultiphaseflow.2014.11.012Castilla R, Gamez-Montero PJ, Ertrk N et al (2010) Numerical simulation of turbulent flow in the suction chamber of a gearpump using deforming mesh and mesh replacement. Int J Mech Sci 52:1334–1342. https://doi.org/10.1016/j.ijmecsci.2010.06.009Parlak Z, Engin T (2012) Time-dependent CFD and quasi-static analysis of magnetorheological fluid dampers with experimental validation. Int J Mech Sci 64:22–31. https://doi.org/10.1016/j.ijmecsci.2012.08.006Chiatti G, Chiavola O, Palmieri F (2009) Spray modeling for diesel engine performance analysis. SAE Tech Pap 2009-01-0835. https://doi.org/10.4271/2009-01-0835Marcer R, Audiffren C, Viel A, et al (2010) Coupling 1D system AMESim and 3D CFD EOLE models for diesel injection simulation Renault. In: ILASS—Eur. 2010, 23rd Annu. Conf. Liq. At. Spray Syst., pp 1–10Desantes JM, Salvador FJ, Carreres M, Martínez-López J (2014) Large-eddy simulation analysis of the influence of the needle lift on the cavitation in diesel injector nozzles. Proc Inst Mech Eng D 229:407–423. https://doi.org/10.1177/0954407014542627Battistoni M, Xue Q, Som S (2016) Large-eddy simulation (LES) of spray transients: start and end of injection phenomena. Oil Gas Sci Technol 71:24. https://doi.org/10.2516/ogst/2015024CONVERGE is a trade mark of convergent science. https://convergecfd.comMacian V, Bermúdez V, Payri R, Gimeno J (2003) New technique for determination of internal geometry of a diesel nozzle with the use of silicone methodology. Exp Tech 27:39–43. https://doi.org/10.1111/j.1747-1567.2003.tb00107.xDabiri S, Sirignano WA, Joseph DD (2007) Cavitation in an orifice flow. Phys Fluids 19:72112. https://doi.org/10.1063/1.2750655Mohan B, Yang W, Chou SK (2014) Cavitation in injector nozzle holes—a parametric study. Eng Appl Comput Fluid Mech 8:70–81Salvador FJ, Hoyas S, Novella R, Martinez-Lopez J (2011) Numerical simulation and extended validation of two-phase compressible flow in diesel injector nozzles. Proc Inst Mech Eng D 225:545–563. https://doi.org/10.1177/09544070JAUTO1569Som S, Longman DE, Ramirez AI, Aggarwal S (2012) Influence of nozzle orifice geometry and fuel properties on flow and cavitation characteristics of a diesel injector. In: Fuel Inject. Automot. Eng., pp 112–126Desantes JM, Salvador FJ, Carreres M, Jaramillo D (2015) Experimental characterization of the thermodynamic properties of diesel fuels over a wide range of pressures and temperatures. SAE Int J Fuels Lubr 8:2015-01-0951. https://doi.org/10.4271/2015-01-0951Bosch W (1966) The fuel rate indicator: a new measuring instrument for display of the characteristics of individual injection. SAE Pap. 660749Payri R, Salvador FJ, Gimeno J, Bracho G (2008) A new methodology for correcting the signal cumulative phenomenon on injection rate measurements. Exp Tech 32:46–49. https://doi.org/10.1111/j.1747-1567.2007.00188.xPayri F, Payri R, Salvador FJ, Martínez-López J (2011) A contribution to the understanding of cavitation effects in diesel injector nozzles through a combined experimental and computational investigation. Comput Fluids 58:88–101. https://doi.org/10.1016/j.compfluid.2012.01.005Lichtarowicz AK, Duggins RK, Markland E (1965) Discharge coefficients for incompressible non-cavitating flow through long orifices. J Mech Eng Sci 7:210–219. https://doi.org/10.1243/JMES_JOUR_1965_007_029_02Lopez JJ, Salvador FJ, De la Garza OA, Arrègle J (2012) Characterization of the pressure losses in a common rail diesel injector. Proc Inst Mech Eng D 226:1697–1706. https://doi.org/10.1177/0954407012447020Salvador FJ, Carreres M, Jaramillo D, Martínez-López J (2015) Comparison of microsac and VCO diesel injector nozzles in terms of internal nozzle flow characteristics. Energy Convers Manag 103:284–299. https://doi.org/10.1016/j.enconman.2015.05.062LMS (2010) Imagine.Lab AMESim v.10. User’s manualPayri R, Salvador FJ, Martí-Aldaraví P, Martínez-López J (2012) Using one-dimensional modeling to analyze the influence of the use of biodiesels on the dynamic behavior of solenoid-operated injectors in common rail systems: detailed injection system model. Energy Convers Manag 54:90–99. https://doi.org/10.1016/j.enconman.2011.10.00

Pyogenic spondylitis

Pyogenic spondylitis is a neurological and life threatening condition. It encompasses a broad range of clinical entities, including pyogenic spondylodiscitis, septic discitis, vertebral osteomyelitis, and epidural abscess. The incidence though low appears to be on the rise. The diagnosis is based on clinical, radiological, blood and tissue cultures and histopathological findings. Most of the cases can be treated non-operatively. Surgical treatment is required in 10–20% of patients. Anterior decompression, debridement and fusion are generally recommended and instrumentation is acceptable after good surgical debridement with postoperative antibiotic cover

In silico modeling indicates the development of HIV-1 resistance to multiple shRNA gene therapy differs to standard antiretroviral therapy

<p>Abstract</p> <p>Background</p> <p>Gene therapy has the potential to counter problems that still hamper standard HIV antiretroviral therapy, such as toxicity, patient adherence and the development of resistance. RNA interference can suppress HIV replication as a gene therapeutic via expressed short hairpin RNAs (shRNAs). It is now clear that multiple shRNAs will likely be required to suppress infection and prevent the emergence of resistant virus.</p> <p>Results</p> <p>We have developed the first biologically relevant stochastic model in which multiple shRNAs are introduced into CD34+ hematopoietic stem cells. This model has been used to track the production of gene-containing CD4+ T cells, the degree of HIV infection, and the development of HIV resistance in lymphoid tissue for 13 years. In this model, we found that at least four active shRNAs were required to suppress HIV infection/replication effectively and prevent the development of resistance. The inhibition of incoming virus was shown to be critical for effective treatment. The low potential for resistance development that we found is largely due to a pool of replicating wild-type HIV that is maintained in non-gene containing CD4+ T cells. This wild-type HIV effectively out-competes emerging viral strains, maintaining the viral <it>status quo</it>.</p> <p>Conclusions</p> <p>The presence of a group of cells that lack the gene therapeutic and is available for infection by wild-type virus appears to mitigate the development of resistance observed with systemic antiretroviral therapy.</p

IL-3 and oncogenic Abl regulate the myeloblast transcriptome by altering mRNA stability

The growth factor interleukin-3 (IL-3) promotes the survival and growth of multipotent hematopoietic progenitors and stimulates myelopoiesis. It has also been reported to oppose terminal granulopoiesis and to support leukemic cell growth through autocrine or paracrine mechanisms. The degree to which IL-3 acts at the posttranscriptional level is largely unknown. We have conducted global mRNA decay profiling and bioinformatic analyses in 32Dcl3 myeloblasts indicating that IL-3 caused immediate early stabilization of hundreds of transcripts in pathways relevant to myeloblast function. Stabilized transcripts were enriched for AU-Response elements (AREs), and an ARE-containing domain from the interleukin-6 (IL-6) 3′-UTR rendered a heterologous gene responsive to IL-3-mediated transcript stabilization. Many IL-3-stabilized transcripts had been associated with leukemic transformation. Deregulated Abl kinase shared with IL-3 the ability to delay turnover of transcripts involved in proliferation or differentiation blockade, relying, in part, on signaling through the Mek/ Erk pathway. These findings support a model of IL-3 action through mRNA stability control and suggest that aberrant stabilization of an mRNA network linked to IL-3 contributes to leukemic cell growth. © 2009 Ernst et al