33 research outputs found
An adherent tissue-inspired hydrogel delivery vehicle utilised in primary human glioma models.
A physical hydrogel cross-linked via the host-guest interactions of cucurbit[8]uril and utilised as an implantable drug-delivery vehicle for the brain is described herein. Constructed from hyaluronic acid, this hydrogel is biocompatible and has a high water content of 98%. The mechanical properties have been characterised by rheology and compared with the modulus of human brain tissue demonstrating the production of a soft material that can be moulded into the cavity it is implanted into following surgical resection. Furthermore, effective delivery of therapeutic compounds and antibodies to primary human glioblastoma cell lines is showcased by a variety of in vitro and ex vivo viability and immunocytochemistry based assays.This work was supported by The Brain Tumour Charity (RG89672), the National Institute for Health Research Cambridge Biomedical Research Centre; the Higher Education Funding Council for England. We acknowledge the Human Research Tissue Bank and Biomedical Research Centre for the tissue being accessed through the Human Research Tissue Bank. The Human Research Tissue Bank is supported by the NIHR Cambridge Biomedical Research Centre. MJR thanks the University of Cambridge Chemical Biology and Molecular Medicine PhD Training Programme for funding. CCP is thankful for the support of the EPSRC and the Brain Tumour Charity for funding. JHM acknowledges the support of the Gates Cambridge Scholarship programme. AKK was supported by a studentship from the John and Lucille van Geest Foundation
Quantum feedback with weak measurements
The problem of feedback control of quantum systems by means of weak
measurements is investigated in detail. When weak measurements are made on a
set of identical quantum systems, the single-system density matrix can be
determined to a high degree of accuracy while affecting each system only
slightly. If this information is fed back into the systems by coherent
operations, the single-system density matrix can be made to undergo an
arbitrary nonlinear dynamics, including for example a dynamics governed by a
nonlinear Schr\"odinger equation. We investigate the implications of such
nonlinear quantum dynamics for various problems in quantum control and quantum
information theory, including quantum computation. The nonlinear dynamics
induced by weak quantum feedback could be used to create a novel form of
quantum chaos in which the time evolution of the single-system wave function
depends sensitively on initial conditions.Comment: 11 pages, TeX, replaced to incorporate suggestions of Asher Pere
Creation of Coherent Superposition States in Inhomogeneously Broadened Media with Relaxation
We propose and analyze a scheme for "on demand" creation of coherent
superposition of meta-stable states in a tripod-structured atom using
frequency-chirped laser pulses. Negligible excitation of the atoms during the
creation of the superposition states is a priority in our consideration. The
underlying physics of the scheme is explained using the formalism of adiabatic
states. By numerically solving master equation for the density matrix operator,
we analyze the influence of the spontaneous decay and transverse relaxation on
the efficiency of the creation of superposition states. We show that the
proposed scheme is robust against small-to-medium variations of the parameters
of the laser pulses. We provide a detailed analysis of the effect of the
inhomogeneous (Doppler-) broadening on the efficiency of the coherence creation
and show that the proposed scheme may be equally efficient in both
homogeneously and Doppler-broadened media
Odontogenic tumors and giant cell lesions of jaws - a nine year study
<p>Abstract</p> <p>Objectives</p> <p>A definite geographic variation has been observed in the frequency of odontogenic tumors and giant cell lesions of the jaws reported from different parts of the world. However, there are a few studies on these lesions, especially giant cell lesions, reported from India. Hence, this study was designed to provide a demographic data on the odontogenic tumors and giant cell lesions reported from our institute located in the city of Hyderabad. Hyderabad is the capital city of the southern state of Andhra Pradesh in India. A retrospective analysis of odontogenic tumors and giant cell lesions of jaws reported in our institute between the years 2000 and 2009 was done and this data was compared with previous reports from different parts of the world and India.</p> <p>Methods</p> <p>Biopsies of the lesions received between the years 2000 and 2009 were reviewed and patient's history, clinical, radiological and histopathological characteristics were analyzed.</p> <p>Results</p> <p>A total of 77 biopsies were received during the nine year study period. These lesions were more frequently seen in the males, in a younger age group and showed a predilection for the mandible. Most of them presented as radiolucent, slow growing and painless lesions. Ameloblastomas (71.4%) constituted the majority of odontogenic tumors while central giant cell granulomas (7.8%) constituted the majority of giant cell lesions.</p> <p>Conclusion</p> <p>These lesions showed a definite geographic variation with ameloblastomas being the most common odontogenic tumors and odontomas being relatively rarer lesions in our region.</p
Recommended from our members
Womenâs experiences of decision-making and informed choice about pregnancy and birth care: a systematic review and meta-synthesis of qualitative research
Background
The purpose of this systematic review (PROSPERO Ref: CRD42017053264) was to describe and interpret the qualitative research on parentâs decision-making and informed choice about their pregnancy and birth care. Given the growing evidence on the benefits of different models of maternity care and the prominence of informed choice in health policy, the review aimed to shed light on the research to date and what the findings indicate.
Methods
a systematic search and screening of qualitative research concerning parentsâ decision-making and informed choice experiences about pregnancy and birth care was conducted using PRISMA guidelines. A meta-synthesis approach was taken for the extraction and analysis of data and generation of the findings. Studies from 1990s onwards were included to reflect an era of policies promoting choice in maternity care in high-income countries.
Results
Thirty-seven original studies were included in the review. A multi-dimensional conceptual framework was developed, consisting of three analytical themes (âUncertaintyâ, âBodily autonomy and integrityâ and âPerforming good motherhoodâ) and three inter-linking actions (âInformation gathering,â âAligning with a birth philosophy,â and âBalancing aspects of a choiceâ).
Conclusions
Despite the increasing research on decision-making, informed choice is not often a primary research aim, and its development in literature published since the 1990s was difficult to ascertain. The meta-synthesis suggests that decision-making is a dynamic and temporal process, in that it is made within a defined period and invokes both the past, whether this is personal, familial, social or historical, and the future. Our findings also highlighted the importance of embodiment in maternal health experiences, particularly when it comes to decision-making about care. Policymakers and practitioners alike should examine critically current choice frameworks to ascertain whether they truly allow for flexibility in decision-making. Health systems should embrace more fluid, personalised models of care to augment service usersâ decision-making agency
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
The Female Subject on the Stage: Self-fashioning and Performing Femininity in Elizabeth Robinsâ The Convert (1907)
Recommended from our members
Mechanically matching the rheological properties of brain tissue for drug-delivery in human glioblastoma models.
Peptide functionalized hyaluronic acid (HACF) cross-linked by cucurbit[8]uril (CB[8]), a new class of drug-delivery reservoirs, is used to enable improved drug bioavailability for glioblastoma tumors in patient-derived xenograft (PDX) models. The mechanical and viscoelastic properties of native human and mouse tissues are measured over 8âŻh via oscillatory rheology under physiological conditions. Treatment with drug-loaded hydrogels allowed for a significant survival impact of 45âŻ% (55.5-80.5 days). A relationship between the type of PDX tumor formed-a consequence of the heterogeneic nature of GB tumors-and changes in the initial survival is observed owing to greater local pressure from stiffer tumors. These biocompatible and tailorable materials warrant use as drug delivery reservoirs in PDX resection models, where the mechanical properties can be readily adjusted to match the stiffness of local tissue and thus have potential to improve the survival of GB patients.EPSRC Doctoral Training Grant, EPSRC reference EP/M508007/1 for lead author Chris Parkins.
This work was supported by The Brain Tumour Charity (GN-000409), the National Institute for Health Research Cambridge Biomedical Research Centre and the Higher Education Funding Council for England. We acknowl- edge the Human Research Tissue Bank and Biomedical Research Centre for a portion of the tissue being accessed. The Human Research Tissue Bank is supported by the NIHR Cambridge Biomedical Research Centre. CCP is thankful for the support of the EPSRC and the Brain Tumour Charity for funding. JHM acknowledges the support of the Gates Cambridge Trust and NIH OxCam Scholarship programme. LR and RJG thank the Mathile Family Foundation for funding