The Off-Shell Electromagnetic T-matrix: momentum-dependent scattering from spherical inclusions with both dielectric and magnetic contrast

The momentum- and frequency-dependent T-matrix operator for the scattering of electromagnetic waves by a dielectric/conducting and para- or diamagnetic sphere is derived as a Mie-type series, and presented in a compact form emphasizing various symmetry properties, notably the unitarity identity. This result extends to magnetic properties one previously obtained for purely dielectric contrasts by other authors. Several situations useful to spatially-dispersive effective-medium approximations to one-body order are examined. Partial summation of the Mie series is achieved in the case of elastic scattering.Comment: 22 pages. Preprint of a paper to appear in `Waves in Complex And Random Media' ((c) Taylor and Francis, 2011

Rectal metastasis of prostate cancer: about a case

Prostate adenocarcinomas present a high risk of metastasis. We report a case of an atypical prostate cancer metastasis. A male patient presented a prostatic adenocarcinoma treated by surgery. A biological recurrence was discovered during the follow-up by an increased rate of Prostate Specific Antigen (PSA) and was treated by hormonotherapy. Several months later, there was a re-increase of the PSA rate. The CT scan showed a radiation proctitis aspect. An intermittent hormonotherapy was decided. Six months later, he presented abdominal pain. Examinations were performed and showed a rectal carcinosarcoma with prostate origins. A surgical management was realised. The outcomes were an early recurrence. A symptomatic treatment was decided. There are not any rectal localisations reported in the literature. Only loco-regional invasions of the rectum are described and no histological modification of metastasis compared to the primitive tumor has been reported. So, we report a metastasis of a prostate adenocarcinoma which transformed into a carcinosarcoma. KEYWORDS: Adenocarcinoma; Carcinosarcoma; Metastasis; Prostate; Rectal neoplasm

Solitary fibrous tumour of the mesorectum: a case report

International audienc

Microscopic theory of vertical-transport phenomena in semiconductor heterostructures: Interplay between two- and three-dimensional hot-carrier relaxation

A theoretical analysis of vertical-transport phenomena in semiconductor heterostructures is presented. In particular, the scattering coupling between two- and three-dimensional states in multiple quantum wells is investigated. To this purpose, a fully three-dimensional approach for the description of both localized and extended states in the heterostructure is proposed. Starting from such three-dimensional states, obtained from a self-consistent Schrödinger-Poisson calculation, a Monte Carlo solution of the corresponding Boltzmann transport equation is performed. In contrast to various phenomenological transport models, the present simulation scheme allows a kinetic description, i.e., based on microscopic scattering rates, of vertical transport across a generic heterostructure. Our results provide a rigorous description of hot-carrier relaxation between extended and localized states. This simulation scheme has been applied to finite multiple quantum wells with different geometries and doping profiles. A detailed analysis of the electron current as a function of temperature in quasiequilibrium conditions shows good agreement with experimental results. Moreover, in non-equilibrium conditions (i.e., hot-carrier regime) the scattering coupling between three- and two-dimensional states is found to play a significant role in modifying the carrier mobility as well as the fraction of conducting electrons

Some methods for blindfolded record linkage

BACKGROUND: The linkage of records which refer to the same entity in separate data collections is a common requirement in public health and biomedical research. Traditionally, record linkage techniques have required that all the identifying data in which links are sought be revealed to at least one party, often a third party. This necessarily invades personal privacy and requires complete trust in the intentions of that party and their ability to maintain security and confidentiality. Dusserre, Quantin, Bouzelat and colleagues have demonstrated that it is possible to use secure one-way hash transformations to carry out follow-up epidemiological studies without any party having to reveal identifying information about any of the subjects – a technique which we refer to as "blindfolded record linkage". A limitation of their method is that only exact comparisons of values are possible, although phonetic encoding of names and other strings can be used to allow for some types of typographical variation and data errors. METHODS: A method is described which permits the calculation of a general similarity measure, the n-gram score, without having to reveal the data being compared, albeit at some cost in computation and data communication. This method can be combined with public key cryptography and automatic estimation of linkage model parameters to create an overall system for blindfolded record linkage. RESULTS: The system described offers good protection against misdeeds or security failures by any one party, but remains vulnerable to collusion between or simultaneous compromise of two or more parties involved in the linkage operation. In order to reduce the likelihood of this, the use of last-minute allocation of tasks to substitutable servers is proposed. Proof-of-concept computer programmes written in the Python programming language are provided to illustrate the similarity comparison protocol. CONCLUSION: Although the protocols described in this paper are not unconditionally secure, they do suggest the feasibility, with the aid of modern cryptographic techniques and high speed communication networks, of a general purpose probabilistic record linkage system which permits record linkage studies to be carried out with negligible risk of invasion of personal privacy

Sodium ion interactions with aqueous glucose: Insights from quantum mechanics, molecular dynamics, and experiment

In the last several decades, significant efforts have been conducted to understand the fundamental reactivity of glucose derived from plant biomass in various chemical environments for conversion to renewable fuels and chemicals. For reactions of glucose in water, it is known that inorganic salts naturally present in biomass alter the product distribution in various deconstruction processes. However, the molecular-level interactions of alkali metal ions and glucose are unknown. These interactions are of physiological interest as well, for example, as they relate to cation-glucose cotransport. Here, we employ quantum mechanics (QM) to understand the interaction of a prevalent alkali metal, sodium, with glucose from a structural and thermodynamic perspective. The effect on B-glucose is subtle: a sodium ion perturbs bond lengths and atomic partial charges less than rotating a hydroxymethyl group. In contrast, the presence of a sodium ion significantly perturbs the partial charges of α-glucose anomeric and ring oxygens. Molecular dynamics (MD) simulations provide dynamic sampling in explicit water, and both the QM and the MD results show that sodium ions associate at many positions with respect to glucose with reasonably equivalent propensity. This promiscuous binding nature of Na + suggests that computational studies of glucose reactions in the presence of inorganic salts need to ensure thorough sampling of the cation positions, in addition to sampling glucose rotamers. The effect of NaCl on the relative populations of the anomers is experimentally quantified with light polarimetry. These results support the computational findings that Na + interacts similarly with a- and B-glucose

Translating Clinical Findings into Knowledge in Drug Safety Evaluation - Drug Induced Liver Injury Prediction System (DILIps)

Drug-induced liver injury (DILI) is a significant concern in drug development due to the poor concordance between preclinical and clinical findings of liver toxicity. We hypothesized that the DILI types (hepatotoxic side effects) seen in the clinic can be translated into the development of predictive in silico models for use in the drug discovery phase. We identified 13 hepatotoxic side effects with high accuracy for classifying marketed drugs for their DILI potential. We then developed in silico predictive models for each of these 13 side effects, which were further combined to construct a DILI prediction system (DILIps). The DILIps yielded 60–70% prediction accuracy for three independent validation sets. To enhance the confidence for identification of drugs that cause severe DILI in humans, the “Rule of Three” was developed in DILIps by using a consensus strategy based on 13 models. This gave high positive predictive value (91%) when applied to an external dataset containing 206 drugs from three independent literature datasets. Using the DILIps, we screened all the drugs in DrugBank and investigated their DILI potential in terms of protein targets and therapeutic categories through network modeling. We demonstrated that two therapeutic categories, anti-infectives for systemic use and musculoskeletal system drugs, were enriched for DILI, which is consistent with current knowledge. We also identified protein targets and pathways that are related to drugs that cause DILI by using pathway analysis and co-occurrence text mining. While marketed drugs were the focus of this study, the DILIps has a potential as an evaluation tool to screen and prioritize new drug candidates or chemicals, such as environmental chemicals, to avoid those that might cause liver toxicity. We expect that the methodology can be also applied to other drug safety endpoints, such as renal or cardiovascular toxicity