Biodegradable PLGA Based Nanoparticles for Sustained Regional Lymphatic Drug Delivery

The purpose of this work is to evaluate biodegradable drug carriers with defined size, hydrophobicity, and surface charge density for preferential lymphatic uptake and retention for sustained regional drug delivery. PLGA–PMA:PLA-PEG (PP) nanoparticles of defined size and relative hydrophobicity were prepared by nanoprecipitation method. These were compared with PS particles of similar sizes and higher hydrophobicity. PLGA–PMA:PLGA-COOH (PC) particles at 80:20, 50:50, and 20:80 ratios were prepared by nanoprecipitation for the charge study. Particle size and zeta potential were characterized by dynamic light scattering and laser doppler anemometry, respectively. Particles were administered in vivo to rats subcutaneously. Systemic and lymph node uptake was evaluated by marker recovery. Lymphatic uptake and node retention of PP nanoparticles was shown to be inversely related to size. Lymphatic uptake and node retention of PP particles, as compared to PS particles, was shown to be inversely related to hydrophobicity. Lastly, lymphatic uptake and node retention of PC nanoparticles were directly related to the anionic charge on the particles. In vivo lymphatic uptake and retention in a rat model indicates that the 50 nm PP particles are ideal for sustained regional delivery into the lymphatics for prevention/treatment of oligometastases

Thermodynamics Inducing Massive Particles' Tunneling and Cosmic Censorship

By calculating the change of entropy, we prove that the first law of black hole thermodynamics leads to the tunneling probability of massive particles through the horizon, including the tunneling probability of massive charged particles from the Reissner-Nordstr\"om black hole and the Kerr-Newman black hole. Novelly, we find the trajectories of massive particles are close to that of massless particles near the horizon, although the trajectories of massive charged particles may be affected by electromagnetic forces. We show that Hawking radiation as massive particles tunneling does not lead to violation of the weak cosmic-censorship conjecture

Meeting report on the Bellagio Conference ‘prevention of vascular diseases in the emerging world: An approach to global health equity’

Representatives from five international organizations (International Society of Nephrology, World Heart Federation, International Diabetes Federation, International Atherosclerosis Federation, and International Society of Hypertension) participated in a strategic planning workshop in December 2005 in Bellagio, Italy sponsored by the Rockefeller Foundation. There were equal representatives from developed and developing countries. Global perspectives on diabetes and cardiovascular and renal diseases were presented, with special emphasis on China, India, Latin America, and Africa. The rationale and effectiveness of preventive measures were discussed. It was apparent that measures for primary prevention and early intervention for all the chronic vascular diseases are similar. The five organizations agreed that an integrated global approach to chronic vascular diseases is needed. They resolved to collaborate and work towards an integrated approach to chronic vascular diseases with the establishment of a 5-year plan for the prevention and treatment of chronic vascular diseases, including public advocacy, advising international and national agencies, and improving education and the practice of established approaches

Meeting report on the Bellagio Conference ‘prevention of vascular diseases in the emerging world: An approach to global health equity’

Representatives from five international organizations (International Society of Nephrology, World Heart Federation, International Diabetes Federation, International Atherosclerosis Federation, and International Society of Hypertension) participated in a strategic planning workshop in December 2005 in Bellagio, Italy sponsored by the Rockefeller Foundation. There were equal representatives from developed and developing countries. Global perspectives on diabetes and cardiovascular and renal diseases were presented, with special emphasis on China, India, Latin America, and Africa. The rationale and effectiveness of preventive measures were discussed. It was apparent that measures for primary prevention and early intervention for all the chronic vascular diseases are similar. The five organizations agreed that an integrated global approach to chronic vascular diseases is needed. They resolved to collaborate and work towards an integrated approach to chronic vascular diseases with the establishment of a 5-year plan for the prevention and treatment of chronic vascular diseases, including public advocacy, advising international and national agencies, and improving education and the practice of established approaches

Black Hole Entropy: From Shannon to Bekenstein

In this note we have applied directly the Shannon formula for information theory entropy to derive the Black Hole (Bekenstein-Hawking) entropy. Our analysis is semi-classical in nature since we use the (recently proposed [8]) quantum mechanical near horizon mode functions to compute the tunneling probability that goes in to the Shannon formula, following the general idea of [5]. Our framework conforms to the information theoretic origin of Black Hole entropy, as originally proposed by Bekenstein.Comment: 9 pages Latex, Comments are welcome; Thoroughly revised version, reference and acknowledgements sections enlarged, numerical error in final result corrected, no major changes, to appear in IJT

A retrospective cohort study of differential attainment, COVID and chaos: taking the difference out of a terrible trinity

Background: This study aimed to evaluate core surgical training (CST) differential attainment related to coronavirus disease 2019 (COVID-19), gender and ethnicity. The hypothesis was that COVID-19 adversely influenced CST outcomes. Methods: A retrospective cohort study of 271 anonymised CST records was undertaken at a UK Statutory Education Body. Primary effect measures were Annual Review of Competency Progression Outcome (ARCPO), Membership of the Royal College of Surgeons (MRCS) examination pass and Higher Surgical Training National Training Number (NTN) appointment. Data were collected prospectively at ARCP and analysed with non-parametric statistical methods in SPSS. Results: CSTs numbering 138 completed training pre-COVID and 133 peri-COVID. ARCPO 1, 2 and 6 were 71.9% pre-COVID versus 74.4% peri-COVID (P = 0.844). MRCS pass rates were 69.6% pre-COVID versus 71.1% peri-COVID (P = 0.968), but NTN appointment rates diminished (pre-COVID 47.4% vs. peri-COVID 36.9%, P = 0.324); none of the above varied by gender or ethnicity. Multivariable analyses by three models revealed: ARCPO was associated with gender [m:f 1:0.87, odds ratio (OR) 0.53, P = 0.043] and CST theme (Plastics vs. General OR 16.82, P = 0.007); MRCS pass with theme (Plastics vs. General OR 8.97, P = 0.004); NTN with the Improving Surgical Training run-through programme (OR 5.00, P < 0.001). Programme retention improved peri-COVID (OR 0.20, P = 0.014) with pan University Hospital rotations performing better than Mixed or District General-only rotations (OR 6.63, P = 0.018). Conclusion: Differential attainment profiles varied 17-fold, yet COVID-19 did not influence ARCPO or MRCS pass rates. NTN appointment fell by one-fifth peri-COVID, but overall training outcome metrics remained robust despite the existential threat

Limits on spin-dependent WIMP-nucleon cross-sections from the first ZEPLIN-II data

The first underground data run of the ZEPLIN-II experiment has set a limit on the nuclear recoil rate in the two-phase xenon detector for direct dark matter searches. In this paper the results from this run are converted into the limits on spin-dependent WIMP-proton and WIMP-neutron cross-sections. The minimum of the curve for WIMP-neutron cross-section corresponds to 0.07 pb at a WIMP mass of around 65 GeV.Comment: 12 pages, 2 figures, to be published in Physics Letters

Horizons, Constraints, and Black Hole Entropy

Black hole entropy appears to be ``universal''--many independent calculations, involving models with very different microscopic degrees of freedom, all yield the same density of states. I discuss the proposal that this universality comes from the behavior of the underlying symmetries of the classical theory. To impose the condition that a black hole be present, we must partially break the classical symmetries of general relativity, and the resulting Goldstone boson-like degrees of freedom may account for the Bekenstein-Hawking entropy. In particular, I demonstrate that the imposition of a ``stretched horizon'' constraint modifies the algebra of symmetries at the horizon, allowing the use of standard conformal field theory techniques to determine the asymptotic density of states. The results reproduce the Bekenstein-Hawking entropy without any need for detailed assumptions about the microscopic theory.Comment: 16 pages, talk given at the "Peyresq Physics 10 Meeting on Micro and Macro structures of spacetime

Method to compute the stress-energy tensor for the massless spin 1/2 field in a general static spherically symmetric spacetime

A method for computing the stress-energy tensor for the quantized, massless, spin 1/2 field in a general static spherically symmetric spacetime is presented. The field can be in a zero temperature state or a non-zero temperature thermal state. An expression for the full renormalized stress-energy tensor is derived. It consists of a sum of two tensors both of which are conserved. One tensor is written in terms of the modes of the quantized field and has zero trace. In most cases it must be computed numerically. The other tensor does not explicitly depend on the modes and has a trace equal to the trace anomaly. It can be used as an analytic approximation for the stress-energy tensor and is equivalent to other approximations that have been made for the stress-energy tensor of the massless spin 1/2 field in static spherically symmetric spacetimes.Comment: 34 pages, no figure

The ZEPLIN II dark matter detector: data acquisition system and data reduction

ZEPLIN-II is a two-phase (liquid/gas) xenon dark matter detector searching for WIMP-nucleon interactions. In this paper we describe the data acquisition system used to record the data from ZEPLIN-II and the reduction procedures which parameterise the data for subsequent analysis.Comment: 11 pages, 10 figure