Total dose hardness of TiN/HfOx/TiN resistive random access memory

Resistive random access memory based on TiN/HfOx/TiN has been fabricated, with the stoichiometry of the HfOx layer altered through control of atomic layer deposition (ALD) temperature. Sweep and pulsed electrical characteristics were extracted before and after 60Co gamma irradiation. Monoclinic HfOx deposited at 400°C did not result in resistive switching. Deposition at 300°C and 350°C resulted in cubic HfOx which switched successfully. Both stoichiometric HfO2 and sub-oxides HfO2-x result in similar memory characteristics. All devices are shown to be radiation hard up to 10 Mrad(Si), independent of stoichiometry

CHOPPI: a web tool for the analysis of immunogenicity risk from host cell proteins in CHO-based protein production

Despite high quality standards and continual process improvements in manufacturing, host cell protein (HCP) process impurities remain a substantial risk for biological products. Even at low levels, residual HCPs can induce a detrimental immune response compromising the safety and efficacy of a biologic. Consequently, advanced-stage clinical trials have been cancelled due to the identification of antibodies against HCPs. To enable earlier and rapid assessment of the risks in Chinese Hamster Ovary (CHO)-based protein production of residual CHO protein impurities (CHOPs), we have developed a web tool called CHOPPI, for CHO Protein Predicted Immunogenicity. CHOPPI integrates information regarding the possible presence of CHOPs (expression and secretion) with characterizations of their immunogenicity (T cell epitope count and density, and relative conservation with human counterparts). CHOPPI can generate a report for a specified CHO protein (e.g., identified from proteomics or immunoassays) or characterize an entire specified subset of the CHO genome (e.g., filtered based on confidence in transcription and similarity to human proteins). The ability to analyze potential CHOPs at a genomic scale provides a baseline to evaluate relative risk. We show here that CHOPPI can identify clear differences in immunogenicity risk among previously validated CHOPs, as well as identify additional ‘risky’ CHO proteins that may be expressed during production and induce a detrimental immune response upon delivery. We conclude that CHOPPI is a powerful tool that provides a valuable computational complement to existing experimental approaches for CHOP risk assessment and can focus experimental efforts in the most important directions

Mass spectrometric quantitation of covalently bound cell wall proteins in Saccharomyces cerevisiae

The cell wall of yeast consists of an internal skeletal layer and an external layer of glycoproteins covalently linked to the stress-bearing polysaccharides. The cell wall protein (CWP) population consists of over 20 different proteins, and may vary in composition. We present two complementary methods for quantifying CWPs, based on isobaric tagging and tandem MS: (1) absolute quantitation of individual CWPs, allowing estimation of surface densities; and (2) relative quantitation of CWPs, allowing monitoring of the dynamics of the CWP population. For absolute quantitation, we selected a representative group of five proteins (Cwp1p, Crh1p, Scw4p, Gas1p, and Ecm33p), which had 67 × 103, 44 × 103, 38 × 103, 11 × 103 and 6.5 × 103 of wall-bound copies per cell, respectively. As Cwp1p is predominantly incorporated in the birth scar, this corresponds to a protein density of c. 22 × 103 copies μm−2. For relative quantitation, we compared wild-type cells to gas1Δ cells, in which the cell wall integrity pathway is constitutively activated. The levels of Crh1p, Crh2p, Ecm33p, Gas5p, Pst1p and Pir3p increased about three- to fivefold, whereas the level of Scw4p was significantly decreased. We propose that our methods are widely applicable to other fungi

Smarter Vaccine Design Will Circumvent Regulatory T Cell-Mediated Evasion in Chronic HIV and HCV Infection

Despite years of research, vaccines against HIV and HCV are not yet available, due largely to effective viral immunoevasive mechanisms. A novel escape mechanism observed in viruses that cause chronic infection is suppression of viral-specific effector CD4(+) and CD8(+) T cells by stimulating regulatory T cells (Tregs) educated on host sequences during tolerance induction. Viral class II MHC epitopes that share a T cell receptor (TCR)-face with host epitopes may activate Tregs capable of suppressing protective responses. We designed an immunoinformatic algorithm, JanusMatrix, to identify such epitopes and discovered that among human-host viruses, chronic viruses appear more human-like than viruses that cause acute infection. Furthermore, an HCV epitope that activates Tregs in chronically infected patients, but not clearers, shares a TCR-face with numerous human sequences. To boost weak CD4(+) T cell responses associated with persistent infection, vaccines for HIV and HCV must circumvent potential Treg activation that can handicap efficacy. Epitope-driven approaches to vaccine design that involve careful consideration of the T cell subsets primed during immunization will advance HIV and HCV vaccine development

Immune Camouflage: Relevance to Vaccine Design and Human Immunology

High strain sequence variability, interference with innate immune mechanisms, and epitope deletion are all examples of strategies that pathogens have evolved to subvert host defenses. To this list we would add another strategy: immune camouflage. Pathogens whose epitope sequences are cross-conserved with multiple human proteins at the TCR-facing residues may be exploiting ignorance and tolerance, which are mechanisms by which mature T cells avoid immune responses to self-antigens. By adopting amino acid configurations that may be recognized by autologous regulatory T cells, pathogens may be actively suppressing protective immunity. Using the new JanusMatrix TCR-homology-mapping tool, we have identified several such \u27camouflaged\u27 tolerizing epitopes that are present in the viral genomes of pathogens such as emerging H7N9 influenza. Thus in addition to the overall low number of T helper epitopes that is present in H7 hemaglutinin (as described previously, see http://dx.doi.org/10.4161/hv.24939), the presence of such tolerizing epitopes in H7N9 could explain why, in recent vaccine trials, whole H7N9-HA was poorly immunogenic and associated with low seroconversion rates (see http://dx.doi.org/10.4161/hv.28135). In this commentary, we provide an overview of the immunoinformatics process leading to the discovery of tolerizing epitopes in pathogen genomic sequences, provide a brief summary of laboratory data that validates the discovery, and point the way forward. Removal of viral, bacterial and parasite tolerizing epitopes may permit researchers to develop more effective vaccines and immunotherapeutics in the future

Faecal volatile organic compounds analysis using field asymmetric ion mobility spectrometry : non-invasive diagnostics in paediatric inflammatory bowel disease

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), remains challenging to diagnose. Diagnostic work up carries a high burden, especially in paediatric patients, due to invasive endoscopic procedures. IBD is associated with alterations in intestinal microbiota composition. Faecal volatile organic compounds (VOCs) reflect gut microbiota composition. Aim of this study was to assess the diagnostic accuracy of faecal VOC profiling as non-invasive diagnostic biomarker for paediatric IBD

CHANGING NURSING CARE TIME AS AN EFFECT OF CHANGED CHARACTERISTICS OF THE DIALYSIS POPULATION

Background: The population of dialysis patients is ageing. Dialysis nurses are confronted with geriatric patients with multiple comorbidities. Nurses are confronted with an increasing burden of care. Objectives: The present study focused on the question of whether, over time, the increasing age and comorbidities of the haemodialysis population increased nursing care time. Furthermore, we studied potential changes in the predictors of the required nursing time. Design: Observational study. Participants: A total of 980 dialysis patients from 12 dialysis centres were included. Measurements: Nurses filled out the classification tool for each patient and completed a form for reporting patient characteristics for groups of relevant haemodialysis patients at baseline and after 1 and four years. Changes in patient and dialysis characteristics were analysed, as well as the estimated nursing care time needed. Results: An increase in the nursing time needed for dialysis was largely due to decreased mobility, closing of the vascular access and a greater need for psychosocial attention and was most strongly present in incident dialysis patients. The time needed for dialysis decreased as patient participation increased and vascular access changed from catheters to fistulae. Over the four-year period, the average overall needed nursing care time per haemodialysis session did not change. Conclusions: Our study shows that the average nursing time needed per patient did not change in the four-year observation period. However, more time is required for incident patients; thus, if a centre has high patient turnover, more nursing care time is needed

Physical and Cognitive Functioning After 3 Years Can Be Predicted Using Information From the Diagnostic Process in Recently Diagnosed Multiple Sclerosis

Objective\ud To predict functioning after 3 years in patients with recently diagnosed multiple sclerosis (MS).\ud \ud Design\ud Inception cohort with 3 years of follow-up. At baseline, predictors were obtained from medical history taking, neurologic examination, and magnetic resonance imaging (MRI).\ud \ud Setting\ud Neurology outpatient clinic.\ud \ud Participants\ud Patients with MS (N=156); 146 with complete follow-up.\ud \ud Interventions\ud Not applicable.\ud \ud Main Outcome Measures\ud Inability to walk at least 500m, impaired dexterity, cognitive impairments, incontinence, inability to drive a car or use public transportation, social dysfunction, and reliance on a disability pension.\ud \ud Results\ud Clinical prediction rules were constructed for the models that were well calibrated (sufficient agreement between predicted and observed outcomes, based on visual inspection of calibration curves) and that showed sufficient discrimination (area under the receiver operation characteristic curve >.70) after internal bootstrap validation. The models for the inability to walk at least 500m, impaired dexterity, and cognitive impairments were well calibrated. Discrimination was sufficient for all 7 models, except the one predicting social dysfunction (.67). The inability to walk at least 500m was predicted by the perceived ability to walk, impairment of the cerebellar tract, and the number of MRI lesions in the spinal cord. Impaired dexterity was predicted by the perceived ability to use the hands, impairments of the pyramidal, cerebellar, and sensory tracts, and the T2-weighted infratentorial lesion load. Cognitive impairment was predicted by age, gender, the perceived ability to concentrate, and the T2-weighted supratentorial lesion load.\ud \ud Conclusions\ud Inability to walk at least 500m, impaired dexterity, and cognitive impairments can be predicted with predictors that are derived from medical history taking, neurologic examination, and MRI shortly after a definite diagnosis of MS has been made.\ud \u