Future aspects of renal transplantation

New and exciting advances in renal transplantation are continuously being made, and the horizons for organ transplantation are bright and open. This article reviews only a few of the newer advances that will allow renal transplantation to become even more widespread and successful. The important and exciting implications for extrarenal organ transplantation are immediately evident. © 1988 Springer-Verlag

Force distributions in a triangular lattice of rigid bars

We study the uniformly weighted ensemble of force balanced configurations on a triangular network of nontensile contact forces. For periodic boundary conditions corresponding to isotropic compressive stress, we find that the probability distribution for single-contact forces decays faster than exponentially. This super-exponential decay persists in lattices diluted to the rigidity percolation threshold. On the other hand, for anisotropic imposed stresses, a broader tail emerges in the force distribution, becoming a pure exponential in the limit of infinite lattice size and infinitely strong anisotropy.Comment: 11 pages, 17 figures Minor text revisions; added references and acknowledgmen

Heat conduction in the disordered harmonic chain revisited

A general formulation is developed to study heat conduction in disordered harmonic chains with arbitrary heat baths that satisfy the fluctuation-dissipation theorem. A simple formal expression for the heat current J is obtained, from which its asymptotic system-size (N) dependence is extracted. It is shown that the ``thermal conductivity'' depends not just on the system itself but also on the spectral properties of the fluctuation and noise used to model the heat baths. As special cases of our heat baths we recover earlier results which reported that for fixed boundaries $J \sim 1/N^{3/2}$, while for free boundaries $J \sim 1/N^{1/2}$. For other choices we find that one can get other power laws including the ``Fourier behaviour'' $J \sim 1/N$.Comment: 5 pages, 3 figures, accepted for publication in Phys. Rev. Let

Parity Effect and Charge Binding Transition in Submicron Josephson Junction Arrays

We reconsider the issue of Berezinskii-Kosterlitz-Thouless (BKT) transition into an insulating state in the Coulomb-dominated Josephson junction arrays. We show that previously predicted picture of the Cooper-pair BKT transtion at T = T_2 is valid only under the condition that T_2 is considerably below the parity-effect temperature (which is usually almost 10 times below the value of superconductive transition temperature), and even in this case it is not a rigorous phase transition but only a crossover, whereas the real phase transition takes place at T_1 = T_2/4. Our theory is in agreement with available experimental data on Coulomb-dominated Josephson arrays and also sheds some light on the origin of unusual reentrant temperature dependence of resistivity in the array with nearly-criticial ratio of Coulomb to Josephson energies.Comment: 4 pages, Revtex, to be published in JETP Letters, April 9

Critical properties of two-dimensional Josephson junction arrays with zero-point quantum fluctuations

We present results from an extensive analytic and numerical study of a two-dimensional model of a square array of ultrasmall Josephson junctions. We include the ultrasmall self and mutual capacitances of the junctions, for the same parameter ranges as those produced in the experiments. The model Hamiltonian studied includes the Josephson, $E_J$, as well as the charging, $E_C$, energies between superconducting islands. The corresponding quantum partition function is expressed in different calculationally convenient ways within its path-integral representation. The phase diagram is analytically studied using a WKB renormalization group (WKB-RG) plus a self-consistent harmonic approximation (SCHA) analysis, together with non-perturbative quantum Monte Carlo simulations. Most of the results presented here pertain to the superconductor to normal (S-N) region, although some results for the insulating to normal (I-N) region are also included. We find very good agreement between the WKB-RG and QMC results when compared to the experimental data. To fit the data, we only used the experimentally determined capacitances as fitting parameters. The WKB-RG analysis in the S-N region predicts a low temperature instability i.e. a Quantum Induced Transition (QUIT). We carefully simulations and carry out a finite size analysis of $T_{QUIT}$ as a function of the magnitude of imaginary time axis $L_\tau$. We find that for some relatively large values of $\alpha=E_C/E_J$ ($1\leq \alpha \leq 2.25)$, the $L_\tau\to\infty$ limit does appear to give a {\it non-zero} $T_{QUIT}$, while for $\alpha \ge 2.5$, $T_{QUIT}=0$. We use the SCHA to analytically understand the $L_\tau$ dependence of the QMC results with good agreement between them. Finally, we also carried out a WKB-RG analysis in the I-N region and found no evidence of a low temperature QUIT, up to lowest order in ${\alpha}^{-1}$Comment: 39 pages, 18 postscript figures, to appear in Phys. Rev.

Scaling Analysis of Magnetic Filed Tuned Phase Transitions in One-Dimensional Josephson Junction Arrays

We have studied experimentally the magnetic field-induced superconductor-insulator quantum phase transition in one-dimensional arrays of small Josephson junctions. The zero bias resistance was found to display a drastic change upon application of a small magnetic field; this result was analyzed in context of the superfluid-insulator transition in one dimension. A scaling analysis suggests a power law dependence of the correlation length instead of an exponential one. The dynamical exponents $z$ were determined to be close to 1, and the correlation length critical exponents were also found to be about 0.3 and 0.6 in the two groups of measured samples.Comment: 4 pages, 4 figure

Quantum interference and Coulomb interaction in arrays of tunnel junctions

We study the electronic properties of an array of small metallic grains connected by tunnel junctions. Such an array serves as a model for a granular metal. Previous theoretical studies of junction arrays were based on models of quantum dissipation which did not take into account the diffusive motion of electrons within the grains. We demonstrate that these models break down at sufficiently low temperatures: for a correct description of the screening properties of a granular metal at low energies the diffusive nature of the electronic motion within the grains is crucial. We present both a diagrammatic and a functional integral approach to analyse the properties of junction arrays. In particular, a new effective action is obtained which enables us to describe the array at arbitrary temperature. In the low temperature limit, our theory yields the correct, dynamically screened Coulomb interaction of a normal metal, whereas at high temperatures the standard description in terms of quantum dissipation is recovered.Comment: 14 pages, 7 figure

Looking ahead at the potential benefits of biotechnology-derived allergen therapeutics

While biotechnology-derived allergen therapeutics show promise in improving the safety of immunotherapy, they may prove to have additional benefits in comparison to conventional allergenic extracts that deserve commentary. These issues range from product stability and compatibility to medical practice issues, which will be the focus of this article

Mothers' beliefs about infant teething in Enugu, South-east Nigeria: a cross sectional study

<p>Abstract</p> <p>Background</p> <p>Parents and Health Care Workers have traditionally attributed a variety of symptoms to teething in young children. Some of these symptoms may however connote underlying serious medical condition in a child. There is little evidence to support these beliefs despite their implications on management of a symptomatic teething child. This study therefore seeks determine the beliefs and problems mothers associate with teething in Enugu, South-east Nigeria.</p> <p>Findings</p> <p>A cross-sectional survey involving sixty mothers presenting at a Children's clinic in Enugu metropolis using questionnaire. More than 90% of the respondents thought that babies can experience medical problems as a result of teething. The commonest medical problems perceived to be associated with teething were fever (71.7%), loose stools (58.3%) and vomiting (35%).</p> <p>Conclusion</p> <p>Mothers still associate a variety of symptoms of childhood illnesses to teething and this association is not evidence based and could lead to delayed interventions, increased morbidity and mortality of children. It is important therefore that mothers and health workers caring for young children are educated on the need to seek prompt medical attentions in a symptomatic child.</p

Ex vivo and in vitro production of pro-inflammatory cytokines in Blau syndrome

SUMMARY The objective was to study both ex vivo and in vitro secretion of pro-inflammatory cytokines in patients affected by Blau syndrome (BS) and carrying p.E383K mutation in the CARD15/NOD2 gene associated with the disease. For ex vivo studies, peripheral blood mononuclear cells (PBMCs), serum from three patients and healthy controls have been collected. PBMCs have been cultured in the presence or absence of inflammatory enhancers, such as lipopolysaccharide (LPS) and muramyl dipeptide (MDP). The levels of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α and interferon (IFN)-γ were assayed by either immunoassay or array-based system. For in vitro studies, different constructs were created cloning human wild-type and p.E383K-mutated NOD2 cDNA into the expression vector pCMV-Tag2c. HEK293 cell lines were stably transfected, cultured with or without MDP and IL-8 level was assayed in their surnatants. Statistical analysis in both studies was performed using non-parametric tests. Both ex vivo and in vitro studies have not identified a significant increase in secretion of the analyzed proinflammatory cytokines. p.E383K-mutated NOD2 transfected cells express low level of IL-8. The ex vivo basal level results from both serum and PBMCs surnatants present similar levels of IL-1β, IL-6, TNF-α and IFN-γ in patients and controls. The presence of the stimulant agents (LPS and MDP), either individual or paired, does not lead to significant increases in all cytokines concentrations in patients compared to controls. Taken together, the ex vivo and in vitro data suggest that there is not a primary mediation of IL-1β and other pro-inflammatory cytokines in BS patients carrying p.E383K