Polyethylene Glycol Camouflaged Earthworm Hemoglobin.

Nearly 21 million components of blood and whole blood and transfused annually in the United States, while on average only 13.6 million units of blood are donated. As the demand for Red Blood Cells (RBCs) continues to increase due to the aging population, this deficit will be more significant. Despite decades of research to develop hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) as RBC substitutes, there are no products approved for clinical use. Lumbricus terrestris erythrocruorin (LtEc) is the large acellular O2 carrying protein complex found in the earthworm Lumbricus terrestris. LtEc is an extremely stable protein complex, resistant to autoxidation, and capable of transporting O2 to tissue when transfused into mammals. These characteristics render LtEc a promising candidate for the development of the next generation HBOCs. LtEc has a short half-life in circulation, limiting its application as a bridge over days, until blood became available. Conjugation with polyethylene glycol (PEG-LtEc) can extend LtEc circulation time. This study explores PEG-LtEc pharmacokinetics and pharmacodynamics. To study PEG-LtEc pharmacokinetics, hamsters instrumented with the dorsal window chamber were subjected to a 40% exchange transfusion with 10 g/dL PEG-LtEc or LtEc and followed for 48 hours. To study the vascular response of PEG-LtEc, hamsters instrumented with the dorsal window chamber received multiple infusions of 10 g/dL PEG-LtEc or LtEc solution to increase plasma LtEc concentration to 0.5, then 1.0, and 1.5 g/dL, while monitoring the animals' systemic and microcirculatory parameters. Results confirm that PEGylation of LtEc increases its circulation time, extending the half-life to 70 hours, 4 times longer than that of unPEGylated LtEc. However, PEGylation increased the rate of LtEc oxidation in vivo. Vascular analysis verified that PEG-LtEc showed the absence of microvascular vasoconstriction or systemic hypertension. The molecular size of PEG-LtEc did not change the colloid osmotic pressure or blood volume expansion capacity compared to LtEc, due to LtEc's already large molecular size. Taken together, these results further encourage the development of PEG-LtEc as an O2 carrying therapeutic

Cleavable Biotin Probes for Labeling of Biomolecules via Azide−Alkyne Cycloaddition

The azide−alkyne cycloaddition provides a powerful tool for bio-orthogonal labeling of proteins, nucleic acids, glycans, and lipids. In some labeling experiments, e.g., in proteomic studies involving affinity purification and mass spectrometry, it is convenient to use cleavable probes that allow release of labeled biomolecules under mild conditions. Five cleavable biotin probes are described for use in labeling of proteins and other biomolecules via azide−alkyne cycloaddition. Subsequent to conjugation with metabolically labeled protein, these probes are subject to cleavage with either 50 mM Na_2S_2O_4, 2% HOCH_2CH_2SH, 10% HCO_2H, 95% CF_3CO_2H, or irradiation at 365 nm. Most strikingly, a probe constructed around a dialkoxydiphenylsilane (DADPS) linker was found to be cleaved efficiently when treated with 10% HCO_2H for 0.5 h. A model green fluorescent protein was used to demonstrate that the DADPS probe undergoes highly selective conjugation and leaves a small (143 Da) mass tag on the labeled protein after cleavage. These features make the DADPS probe especially attractive for use in biomolecular labeling and proteomic studies

Acute kidney injury contributes to worse physical and quality of life outcomes in survivors of critical illness

Objectives: Survivors of critical illness and acute kidney injury (AKI) are at risk of increased morbidity. The purpose of this study was to compare physical, emotional, and cognitive health in survivors of critical illness with and without AKI. Methods: Retrospective cohort study of adult (≥ 18 years old) survivors of critical illness due to sepsis and/or acute respiratory failure who attended follow-up in a specialized ICU Recovery Clinic. Outcomes were evaluated during 3-month visit and comprised validated tests for evaluation of physical function, muscle strength, cognitive and emotional health, and self-reported health-related quality of life (HRQOL). Descriptive statistics and group comparisons were performed. Results: A total of 104 patients with median age of 55 [49-64] years, 54% male, and median SOFA score of 10 [8-12] were analyzed. Incidence of AKI during ICU admission was 61 and 19.2% of patients required renal replacement therapy (RRT). Patients with AKI stage 2 or 3 (vs. those with AKI stage 1 or no AKI) walked less on the 6-min walk test (223 ± 132 vs. 295 ± 153 m, p = 0.059) and achieved lower of the predicted walk distance (38% vs. 58%, p = 0.041). Similar patterns of worse physical function and more significant muscle weakness were observed in multiple tests, with overall worse metrics in patients that required RRT. Patients with AKI stage 2 or 3 also reported lower HRQOL scores when compared to their counterparts, including less ability to return to work or hobby, or reengage in driving. There were no significant differences in cognitive function or emotional health between groups. Conclusions: Survivors of critical illness and AKI stage 2 or 3 have increased physical debility and overall lower quality of life, with more impairment in return to work, hobby, and driving when compared to their counterparts without AKI or AKI stage 1 at 3 months post-discharge

Hybrid additive and subtractive machine tools - research and industrial developments

By synergistically combining additive and subtractive processes within a single workstation, the relative merits of each process may be harnessed. This facilitates the manufacture of internal, overhanging and high aspect ratio features with desirable geometric accuracy and surface characteristics. The ability to work, measure and then rework material enables the reincarnation and repair of damaged, high-value components. These techniques present significant opportunities to improve material utilisation, part complexity and quality management in functional parts.The number of single platform workstations for hybrid additive and subtractive processes (WHASPs) is increasing. Many of these integrate additive directed energy deposition (DED) with subtractive CNC machining within a highly mobile multi-axis machine tool. Advanced numerical control (NC), and computer aided design (CAD), manufacture (CAM) and inspection (CAI) help to govern the process.This research reviews and critically discusses salient published literature relating to the development of WHASPs, and identifies future avenues for research and development. It reports on state-of-the-art WHASP systems, identifying key traits and research gaps. Finally, a future vision for WHASPs and other hybrid machine tools is presented based upon emerging trends and future opportunities within this research are

Turbulent Magnetic Field Amplification from Spiral SASI Modes: Implications for Core-Collapse Supernovae and Proto-Neutron Star Magnetization

We extend our investigation of magnetic field evolution in three-dimensional flows driven by the stationary accretion shock instability (SASI) with a suite of higher-resolution idealized models of the post-bounce core-collapse supernova environment. Our magnetohydrodynamic simulations vary in initial magnetic field strength, rotation rate, and grid resolution. Vigorous SASI-driven turbulence inside the shock amplifies magnetic fields exponentially; but while the amplified fields reduce the kinetic energy of small-scale flows, they do not seem to affect the global shock dynamics. The growth rate and final magnitude of the magnetic energy are very sensitive to grid resolution, and both are underestimated by the simulations. Nevertheless our simulations suggest that neutron star magnetic fields exceeding $10^{14}$ G can result from dynamics driven by the SASI, \emph{even for non-rotating progenitors}.Comment: 28 pages, 17 figures, accepted for publication in the Ap

Cell-selective metabolic labeling of proteins

Metabolic labeling of proteins with the methionine surrogate azidonorleucine can be targeted exclusively to specified cells through expression of a mutant methionyl-tRNA synthetase (MetRS). In complex cellular mixtures, proteins made in cells that express the mutant synthetase can be tagged with affinity reagents (for detection or enrichment) or fluorescent dyes (for imaging). Proteins made in cells that do not express the mutant synthetase are neither labeled nor detected

Controlling size, shape and homogeneity of embryoid bodies using poly(ethylene glycol) microwells

Directed differentiation of embryonic stem (ES) cells is useful for creating models of human disease and could potentially generate a wide array of functional cell types for therapeutic applications. Methods to differentiate ES cells often involve the formation of cell aggregates called embryoid bodies (EBs), which recapitulate early stages of embryonic development. EBs are typically made from suspension cultures, resulting in heterogeneous structures with a wide range of sizes and shapes, which may influence differentiation. Here, we use microfabricated cell-repellant poly(ethylene glycol) (PEG) wells as templates to initiate the formation of homogenous EBs. ES cell aggregates were formed with controlled sizes and shapes defined by the geometry of the microwells. EBs generated in this manner remained viable and maintained their size and shape within the microwells relative to their suspension counterparts. Intact EBs could be easily retrieved from the microwells with high viability (> 95%). These results suggest that the microwell technique could be a useful approach for in vitro studies involving ES cells and, more specifically, for initiating the differentiation of EBs of greater uniformity based on controlled microenvironments.This research has been supported by NIH (NIH grant # HL60435), Draper laboratory, Institute of Soldier Nanotechnology (DAAD-19-02-D-002), and the NSF (through the Bioprocess Engineering Research Center). JF is supported by a Grant-in-Aid for JSPS fellows, 16–4754, 2004

IT controls in the public cloud : success factors for allocation of roles and responsibilities

The rapid adoption of cloud computing by organizations has resulted in the transformation of the roles and responsibilities of staff in managing the information technology (IT) resources (via IT governance controls) that have migrated to the cloud. Hence, the objective of this research is to provide a set of success factors that can assist IT managers to allocate the roles and responsibilities of IT controls appropriately to staff to manage the migrated IT resources. Accordingly, we generated a set of success factors from behavioral and information systems (IS) literature. These success factors were verified using in-depth interviews of executives from the United Arab Emirates (UAE). The empirical intervention suggests that the role allocation is driven predominantly by people’s skills, competencies, organizational strategy, structures, and policies. In addition, the research made clear that the most significant competency and skill for a person allocated to IT controls is to be able to evaluate and manage a cloud service provider, especially in terms of risks, compliance, and security issues related to public cloud technology. The findings of this study not only offer new insights for scholars and practitioners involved in assigning responsibilities but also provide extensions for IT governance framework authorities to align their guidelines to the emerging cloud technology

Manufacturing technologies and joining methods of metallic thin-walled pipes for use in high pressure cooling systems

Small diameter thin-walled pipes, typically with a diameter less than 20 mm and a ratio of outer diameter to wall thickness is 20 or above, have increasingly become a key value adding factor for a number of industries including medical applications, electronics and chemical industries. In high-energy physics experiments, thin-walled pipes are needed in tracking detector cooling systems where the mass of all components needs to be minimised for physics measurement reasons. The pipework must reliably withstand the cooling fluid operation pressures (of up to 100 bar), but must also be able to be reliably and easily joined within the cooling system. Suitable standard and/or commercial solutions combining the needed low mass and reliable high-pressure operation are poorly available. The following review of literature compares the various techniques that exist for the manufacture and joining of thin-walled pipes, both well-established techniques and novel methods which have potential to increase the use of thin-walled pipes within industrial cooling systems. Gaps in knowledge have been identified, along with further research directions. Operational challenges and key considerations which have to be identified when designing a system which uses thin-walled pipes are also discussed

Understanding teaching assistant self-efficacy in role and in training: its susceptibility to influence

There has been a noted growth in the number of teaching assistants (TAs) in mainstream schools (DfE, 2013a). Research is inconclusive about their efficacy at changing outcomes for children (Alborz et al 2009; Blatchford et al, 2009) and has proposed more training for TAs (Russell et al, 2005). Generic training models have suggested that enhancing self-efficacy in turn improves performance. This exploratory study investigated factors that may influence TAs’ sense of self-efficacy and its susceptibility to influence in training. Following two modes of mode of school-based training by Educational Psychologists (EPs) data were collected from 14 mainstream secondary school TAs using focus groups. A thematic analysis noted themes regarding self-efficacy, aligned with Bandura’s (1977) sources of information, outcome expectations and whole school support and norms. Review of the data is likely to be able to guide potential trainers to coach consult strategies which are self-efficacy supportive and which address contextual factors including the perceived status of TAs in schools