1,234 research outputs found
An investigation into the feasibility of myoglobin-based single-electron transistors
Myoglobin single-electron transistors were investigated using nanometer- gap
platinum electrodes fabricated by electromigration at cryogenic temperatures.
Apomyoglobin (myoglobin without heme group) was used as a reference. The
results suggest single electron transport is mediated by resonant tunneling
with the electronic and vibrational levels of the heme group in a single
protein. They also represent a proof-of-principle that proteins with redox
centers across nanometer-gap electrodes can be utilized to fabricate
single-electron transistors. The protein orientation and conformation may
significantly affect the conductance of these devices. Future improvements in
device reproducibility and yield will require control of these factors
Dealing with Complexity: Infant Feeding Choices and Experiences for Mothers with Infants in Neonatal Intensive Care Units and Transitional Care Wards
EXECUTIVE SUMMARY The central aim of the research on which this document reports was: To explore the knowledge, perceptions and experiences of infant feeding of mothers with infants in neonatal intensive care units (NICU) and transitional care wards (TCW) and the support these mothers receive from healthcare professionals and significant others with the aim of contributing to further support of mothers, significant others and healthcare professionals in the future. The objectives were: 1. To explore mothers’ with infants in NICU knowledge and understanding of infant, feeding and how this influences feeding choices. 2. To gain an understanding of mothers experiences of infant feeding, 3. To investigate the challenges of infant feeding in NICU. 4. To explore the significance of their self-identity and perception as ‘good’ or ‘not so good’ mothers in relation to this choice. 5. To ascertain the support women receive from healthcare professionals and significant others. 6. To identify further research needs, develop service provision and inform practice and policy. Background to the study is supported by a review of the clinical and sociologically relevant literature and brief detail on a previous related study (Stenhouse and Letherby 2013) which focused on the experience of mothers’ whose pregnancies were complicated by diabetes. A mixed method ethnographic approach was adopted: • Observations in the NICU and TCW were undertaken (alongside interviewing) amounting to approximately six hours. • One-to-one and dyad/group interviewing were undertaken with mothers and some of their partners. • Questionnaires (consisting of 10 questions, some of which were open to allow more respondent input) were distributed to all healthcare professionals working in NICU and TCW. An audit involving a systematic and independent examination of maternal and infant notes was undertaken at the same time as the primary data was collected. DATA AND DISCUSSION The Audit: This section provides a snapshot of infant feeding and expression of breastmilk from a cohort of mothers and babies who had previously been cared for in NICU, TCW or both. Appendix IV is a copy of a poster presented as part of the Medical Training Special Studies Unit. Interview and Questionnaire Data: This section reports on data collected from women, significant others and healthcare professionals and includes detailed reference to the significance of ‘The Journey’, the mixed experience of ‘Skills and Support’ and the experiences of ‘Pleasure, Pressure and Propaganda’. CONCLUSIONS, IMPLICATIONS AND RECOMMENDATIONS Six summary points 1. Training for staff is mixed and this is linked to confidence in supporting women. 2. Women ‘sensed’ the lack of confidence of some staff and this caused anxiety i.e. if the combination of staff on a shift had little experience/knowledge. 3. Women recognised that certain occupation groups had more time and experience to support them i.e. nursery nurses on TCW, midwives on NICU. 4. The physical environment was an issue for respondents. For example: a. TCW privacy, or not, when expressing and feeding. b. In NICU screens used for expressing or feeding sometimes caused anxiety given that screens are also used when baby is poorly/undergoing a procedure. 5. In TCW, formula feed was linked to early discharge resulting in some experiencing subtle pressure to formula feed. 6. Community outreach team very supportive to some and women respondents felt they would have benefited from longer support. Six recommendations 1. Training needs to be consistent for all grades of staff and a whole day annually is preferred by healthcare professional respondents. 2. Release from service essential to ensure training is undertaken and given the high priority it deserves. 3. Different coloured screens for expressing/feeding AND for procedures would be beneficial and reduce stress for mothers and significant others. 4. Active recruitment of peer supporters with experience of having a baby in NICU. 5. Ensure continued support from peer supporters when moving from breastfeeding to formula feeding. 6. More information related to equipment available in the community on discharge i.e. hospital grade breast pumps
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Comprehensive Immune Monitoring of Clinical Trials to Advance Human Immunotherapy.
The success of immunotherapy has led to a myriad of clinical trials accompanied by efforts to gain mechanistic insight and identify predictive signatures for personalization. However, many immune monitoring technologies face investigator bias, missing unanticipated cellular responses in limited clinical material. We present here a mass cytometry (CyTOF) workflow for standardized, systems-level biomarker discovery in immunotherapy trials. To broadly enumerate immune cell identity and activity, we established and extensively assessed a reference panel of 33 antibodies to cover major cell subsets, simultaneously quantifying activation and immune checkpoint molecules in a single assay. This assay enumerates ≥98% of peripheral immune cells with ≥4 positively identifying antigens. Robustness and reproducibility are demonstrated on multiple samples types, across two research centers and by orthogonal measurements. Using automated analysis, we identify stratifying immune signatures in bone marrow transplantation-associated graft-versus-host disease. Together, this validated workflow ensures comprehensive immunophenotypic analysis and data comparability and will accelerate biomarker discovery
Force and energy dissipation variations in non-contact atomic force spectroscopy on composite carbon nanotube systems
UHV dynamic force and energy dissipation spectroscopy in non-contact atomic
force microscopy were used to probe specific interactions with composite
systems formed by encapsulating inorganic compounds inside single-walled carbon
nanotubes. It is found that forces due to nano-scale van der Waals interaction
can be made to decrease by combining an Ag core and a carbon nanotube shell in
the Ag@SWNT system. This specific behaviour was attributed to a significantly
different effective dielectric function compared to the individual
constituents, evaluated using a simple core-shell optical model. Energy
dissipation measurements showed that by filling dissipation increases,
explained here by softening of C-C bonds resulting in a more deformable
nanotube cage. Thus, filled and unfilled nanotubes can be discriminated based
on force and dissipation measurements. These findings have two different
implications for potential applications: tuning the effective optical
properties and tuning the interaction force for molecular absorption by
appropriately choosing the filling with respect to the nanotube.Comment: 22 pages, 6 figure
Composition, taxonomy and functional diversity of the oropharynx microbiome in individuals with schizophrenia and controls.
The role of the human microbiome in schizophrenia remains largely unexplored. The microbiome has been shown to alter brain development and modulate behavior and cognition in animals through gut-brain connections, and research in humans suggests that it may be a modulating factor in many disorders. This study reports findings from a shotgun metagenomic analysis of the oropharyngeal microbiome in 16 individuals with schizophrenia and 16 controls. High-level differences were evident at both the phylum and genus levels, with Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria dominating both schizophrenia patients and controls, and Ascomycota being more abundant in schizophrenia patients than controls. Controls were richer in species but less even in their distributions, i.e., dominated by fewer species, as opposed to schizophrenia patients. Lactic acid bacteria were relatively more abundant in schizophrenia, including species of Lactobacilli and Bifidobacterium, which have been shown to modulate chronic inflammation. We also found Eubacterium halii, a lactate-utilizing species. Functionally, the microbiome of schizophrenia patients was characterized by an increased number of metabolic pathways related to metabolite transport systems including siderophores, glutamate, and vitamin B12. In contrast, carbohydrate and lipid pathways and energy metabolism were abundant in controls. These findings suggest that the oropharyngeal microbiome in individuals with schizophrenia is significantly different compared to controls, and that particular microbial species and metabolic pathways differentiate both groups. Confirmation of these findings in larger and more diverse samples, e.g., gut microbiome, will contribute to elucidating potential links between schizophrenia and the human microbiota
The Msx1 Homeoprotein Recruits G9a Methyltransferase to Repressed Target Genes in Myoblast Cells
Although the significance of lysine modifications of core histones for regulating gene expression is widely appreciated, the mechanisms by which these modifications are incorporated at specific regulatory elements during cellular differentiation remains largely unknown. In our previous studies, we have shown that in developing myoblasts the Msx1 homeoprotein represses gene expression by influencing the modification status of chromatin at its target genes. We now show that genomic binding by Msx1 promotes enrichment of the H3K9me2 mark on repressed target genes via recruitment of G9a histone methyltransferase, the enzyme responsible for catalyzing this histone mark. Interaction of Msx1 with G9a is mediated via the homeodomain and is required for transcriptional repression and regulation of cellular differentiation, as well as enrichment of the H3K9me2 mark in proximity to Msx1 binding sites on repressed target genes in myoblast cells as well as the developing limb. We propose that regulation of chromatin status by Msx1 recruitment of G9a and other histone modifying enzymes to regulatory regions of target genes represents an important means of regulating the gene expression during development
Comprehensive Immune Monitoring of Clinical Trials to Advance Human Immunotherapy
The success of immunotherapy has led to a myriad of clinical trials accompanied by efforts to gain mechanistic insight and identify predictive signatures for personalization. However, many immune monitoring technologies face investigator bias, missing unanticipated cellular responses in limited clinical material. We present here a mass cytometry (CyTOF) workflow for standardized, systems-level biomarker discovery in immunotherapy trials. To broadly enumerate immune cell identity and activity, we established and extensively assessed a reference panel of 33 antibodies to cover major cell subsets, simultaneously quantifying activation and immune checkpoint molecules in a single assay. This assay enumerates >= 98% of peripheral immune cells with >= 4 positively identifying antigens. Robustness and reproducibility are demonstrated on multiple samples types, across two research centers and by orthogonal measurements. Using automated analysis, we identify stratifying immune signatures in bone marrow transplantation-associated graft-versus-host disease. Together, this validated workflow ensures comprehensive immunophenotypic analysis and data comparability and will accelerate biomarker discovery
Systemic immunity is required for effective cancer immunotherapy
Immune responses involve coordination across cell types and tissues. However, studies in cancer immunotherapy have focused heavily on local immune responses in the tumor microenvironment. To investigate immune activity more broadly, we performed an organism-wide study in genetically engineered cancer models using mass cytometry. We analyzed immune responses in several tissues after immunotherapy by developing intuitive models for visualizing single-cell data with statistical inference. Immune activation was evident in the tumor and systemically shortly after effective therapy was administered. However, during tumor rejection, only peripheral immune cells sustained their proliferation. This systemic response was coordinated across tissues and required for tumor eradication in several immunotherapy models. An emergent population of peripheral CD4 T cells conferred protection against new tumors and was significantly expanded in patients responding to immunotherapy. These studies demonstrate the critical impact of systemic immune responses that drive tumor rejection
Reconstructing Gene Regulatory Networks That Control Hematopoietic Commitment.
Hematopoietic stem cells (HSCs) reside at the apex of the hematopoietic hierarchy, possessing the ability to self-renew and differentiate toward all mature blood lineages. Along with more specialized progenitor cells, HSCs have an essential role in maintaining a healthy blood system. Incorrect regulation of cell fate decisions in stem/progenitor cells can lead to an imbalance of mature blood cell populations-a situation seen in diseases such as leukemia. Transcription factors, acting as part of complex regulatory networks, are known to play an important role in regulating hematopoietic cell fate decisions. Yet, discovering the interactions present in these networks remains a big challenge. Here, we discuss a computational method that uses single-cell gene expression data to reconstruct Boolean gene regulatory network models and show how this technique can be applied to enhance our understanding of transcriptional regulation in hematopoiesis.Work in the author’s laboratory is supported by grants from the Wellcome,
Bloodwise, Cancer Research UK, NIH-NIDDK and core support grants by the Wellcome to the Cambridge Institute for Medical Research and Wellcome & MRC Cambridge Stem Cell Institute. F.K.H. is a recipient of a Medical Research Council PhD Studentship
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