Nuclear DNA and protein content evaluation in Taxus plant cell cultures using multiparameter flow cytometry

Plant cell cultures of Taxus provide the most reliable production methods for the anti-cancer drug paclitaxel. In order to comprehend the inherent culture heterogeneity and production variability in cell cultures, it is essential that the cellular metabolism is studied at the genomic level. Genomic stability in plant cell cultures is crucial as it affects cell growth and division, metabolite accumulation and protein synthesis. A rapid and efficient method to prepare nuclei suspensions from aggregated cell cultures of Taxus was employed. Methods were subsequently developed to simultaneously stain them for DNA and protein content using Propidium Iodide and Fluorescein Isothiocyanate respectively. Flow cytometry was used to analyze and quantify the DNA content and genome size of Taxus using known reference species as standards. Furthermore, their genomic stability was evaluated by correlating DNA content and genome size with cell size and complexity, protein content, and elicitation effects using multiparameter flow cytometry. These techniques to evaluate and correlate various culture characteristics can be very useful in designing superior bio processes for enhanced production.


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Evolution of Collective Motion in a Model Glass-Forming Liquid During Physical Aging

At temperatures moderately below their glass transition temperature, the properties of many glassforming materials can evolve slowly with time in a process known as physical aging whereby the thermodynamic, mechanical, and dynamic properties all drift towards their equilibrium values. In this work, we study the evolution of the thermodynamic and dynamic properties during physical aging for a model polymer glass. Specifically, we test the relationship between an estimate of the size of the cooperative rearrangements taking the form of strings and the effective structural relaxation time predicted by the Adam-Gibbs relationship for both an equilibrium supercooled liquid and the same fluid undergoing physical aging towards equilibrium after a series of temperature jumps. We find that there is apparently a close correlation between a structural feature of the fluid, the size of the string-like rearrangements, and the structural relaxation time, although the relationship for the aging fluid appears to be distinct from that of the fluid at equilibrium

Admit your weakness: Verifying correctness on TSO architectures

“The final publication is available at http://link.springer.com/chapter/10.1007%2F978-3-319-15317-9_22 ”.Linearizability has become the standard correctness criterion for fine-grained non-atomic concurrent algorithms, however, most approaches assume a sequentially consistent memory model, which is not always realised in practice. In this paper we study the correctness of concurrent algorithms on a weak memory model: the TSO (Total Store Order) memory model, which is commonly implemented by multicore architectures. Here, linearizability is often too strict, and hence, we prove a weaker criterion, quiescent consistency instead. Like linearizability, quiescent consistency is compositional making it an ideal correctness criterion in a component-based context. We demonstrate how to model a typical concurrent algorithm, seqlock, and prove it quiescent consistent using a simulation-based approach. Previous approaches to proving correctness on TSO architectures have been based on linearizabilty which makes it necessary to modify the algorithm’s high-level requirements. Our approach is the first, to our knowledge, for proving correctness without the need for such a modification

Quiescent consistency: Defining and verifying relaxed linearizability

Concurrent data structures like stacks, sets or queues need to be highly optimized to provide large degrees of parallelism with reduced contention. Linearizability, a key consistency condition for concurrent objects, sometimes limits the potential for optimization. Hence algorithm designers have started to build concurrent data structures that are not linearizable but only satisfy relaxed consistency requirements. In this paper, we study quiescent consistency as proposed by Shavit and Herlihy, which is one such relaxed condition. More precisely, we give the first formal definition of quiescent consistency, investigate its relationship with linearizability, and provide a proof technique for it based on (coupled) simulations. We demonstrate our proof technique by verifying quiescent consistency of a (non-linearizable) FIFO queue built using a diffraction tree. © 2014 Springer International Publishing Switzerland

Performance of two head injury decision rules evaluated on an external cohort of 18,913 children

The Pediatric Emergency Care Applied Research Network (PECARN) decision rule demonstrates high sensitivity for identifying children at low risk for clinically important traumatic brain injury (ciTBI). As with the PECARN rule, the Israeli Decision Algorithm for Identifying TBI in Children (IDITBIC) recommends proceeding directly to computed tomography (CT) in children with Glasgow Coma Score (GCS) lower than 15. The aim was to assess the diagnostic accuracy of two clinical rules that assign children with GCS lower than 15 at presentation directly to CT

Physiological roles of macrophages

Macrophages are present in mammals from midgestation, contributing to physiologic homeostasis throughout life. Macrophages arise from yolk sac and foetal liver progenitors during embryonic development in the mouse and persist in different organs as heterogeneous, self-renewing tissue-resident populations. Bone marrow-derived blood monocytes are recruited after birth to replenish tissue-resident populations and to meet further demands during inflammation, infection and metabolic perturbations. Macrophages of mixed origin and different locations vary in replication and turnover, but are all active in mRNA and protein synthesis, fulfilling organ-specific and systemic trophic functions, in addition to host defence. In this review we emphasise selected properties and non-immune functions of tissue macrophages which contribute to physiologic homeostasis

Sedation and Analgesia for Reduction of Pediatric Ileocolic Intussusception

IMPORTANCE: Ileocolic intussusception is an important cause of intestinal obstruction in children. Reduction of ileocolic intussusception using air or fluid enema is the standard of care. This likely distressing procedure is usually performed without sedation or analgesia, but practice variation exists. OBJECTIVE: To characterize the prevalence of opioid analgesia and sedation and assess their association with intestinal perforation and failed reduction. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study reviewed medical records of children aged 4 to 48 months with attempted reduction of ileocolic intussusception at 86 pediatric tertiary care institutions in 14 countries from January 2017 to December 2019. Of 3555 eligible medical records, 352 were excluded, and 3203 medical records were eligible. Data were analyzed in August 2022. EXPOSURES: Reduction of ileocolic intussusception. MAIN OUTCOMES AND MEASURES: The primary outcomes were opioid analgesia within 120 minutes of reduction based on the therapeutic window of IV morphine and sedation immediately before reduction of intussusception. RESULTS: We included 3203 patients (median [IQR] age, 17 [9-27] months; 2054 of 3203 [64.1%] males). Opioid use was documented in 395 of 3134 patients (12.6%), sedation 334 of 3161 patients (10.6%), and opioids plus sedation in 178 of 3134 patients (5.7%). Perforation was uncommon and occurred in 13 of 3203 patients (0.4%). In the unadjusted analysis, opioids plus sedation (odds ratio [OR], 5.92; 95% CI, 1.28-27.42; P = .02) and a greater number of reduction attempts (OR, 1.48; 95% CI, 1.03-2.11; P = .03) were significantly associated with perforation. In the adjusted analysis, neither of these covariates remained significant. Reductions were successful in 2700 of 3184 attempts (84.8%). In the unadjusted analysis, younger age, no pain assessment at triage, opioids, longer duration of symptoms, hydrostatic enema, and gastrointestinal anomaly were significantly associated with failed reduction. In the adjusted analysis, only younger age (OR, 1.05 per month; 95% CI, 1.03-1.06 per month; P \u3c .001), shorter duration of symptoms (OR, 0.96 per hour; 95% CI, 0.94-0.99 per hour; P = .002), and gastrointestinal anomaly (OR, 6.50; 95% CI, 2.04-20.64; P = .002) remained significant. CONCLUSIONS AND RELEVANCE: This cross-sectional study of pediatric ileocolic intussusception found that more than two-thirds of patients received neither analgesia nor sedation. Neither was associated with intestinal perforation or failed reduction, challenging the widespread practice of withholding analgesia and sedation for reduction of ileocolic intussusception in children

Nanomechanics of glassy polymers under confinement

Many of today\u27s nanotechnologies and processes rely on highly confined (\u3c 30 nm) polymer glasses and polymer nanocomposites. These materials have aided the development of smaller and faster computer chips, improved energy storage devices, protective coatings, and next generation materials with enhanced mechanical, electrical, and optical properties. However, confinement of these materials introduces interfaces, which may drastically change fundamental properties of the material. For example, confinement of polymer glasses has shown to cause changes in the elastic modulus, which in turn may lead to significant adverse effects on the end-use applications of these materials. Understanding how confinement changes the properties of the material may provide us with a mechanism to control it, enabling the production of better materials on the nano scale. Fortunately, the length scales where confinement has an effect are reasonable to model using computer simulations. This Thesis investigates the confinement of polymer glasses and polymer nanocomposites using molecular dynamics and Monte Carlo simulations. In Chapter 2, we use a coarse-grained model to investigate the effect of backbone rigidity and confinement on polymer glasses in bulk and free-standing thin films. We extend this model throughout the entire Thesis. In Chapters 3-4, we study the process of physical aging and its role on local mobility in thin films, and, for the first time, we find a bulk property which may control important dynamical length scales in the film. In Chapter 5, we investigate the mechanical properties of confined model nanopillars, which have not been previously simulated in the context of polymer glasses, and develop close phenomenological connections between polymer glasses and metallic glasses by looking at the local non-affine strain. Lastly, in Chapter 6, we turn to polymer nanocomposites, and study the mechanism by which polymers infiltrate a highly packed nanoparticle film, a method that has been recently discovered to produce polymer nanocomposite films with very high loadings. By investigating all of these systems on the molecular level, we explain some of the underlying physics, and our results shed light on several controversies present in the literature

The chemical and microstructural signature of peri-implantitis on titanium dental implants’ surface

Titanium and titanium alloys are deemed to be biocompatible materials. But what happens to the biomaterial when the environment and/or the working conditions change? This study aims to identify changes in the surface chemistry and morphology of retrieved titanium dental implants after exposure to the inflammatory conditions that are characteristic of peri-implantitis. The surface of unused (reference) and retrieved dental implants are systematically compared at two distinct scales, namely micron and nano, using high-resolution analysis microscopic methods (SEM, Tof-SIMS and S/TEM).At the micron scale, a profusion of (micron-size) metallic particles were observed only on the top area of the retrieved implants. For those implants, significant nanoscale damage to the (protective) oxide layer was observed, consisting of changes in thickness, composition, and atomic arrangement (amorphization), as opposed to that of the reference implants. An organic compound, denoted by CNx, was found to infiltrate the oxide layer, rendering it significantly thicker, porous, and weak with evidence of delamination.We present a systematic methodology to study biocompatibility and degradation processes in those implants, exposing unambiguously the severe degradation of the protective oxide layer that should guide further studies aimed at increasing the implants’ resistance to their biological environment.The results reported herein do not differentiate between implants of different origins, make and/or patients’ history, so that these results confer a definite generality to the protective layer's degradation related to peri-implantitis