Radiographic features of liver allograft rejection

The radiographic features of 19 transplanted patients with failure of the liver allograft were evaluated. These features were: poor filling, stretching, attenuation of intrahepatic biliary ducts documented by T-tube cholangiogram, attenuation of branches of the hepatic artery seen on angiogram as well as a decrease of blood flow through the liver seen on angiogram and nuclear medicine dynamic scintigram. These findings were secondary to swelling of the transplanted liver and were not specific for rejection; they may also be present in hepatic infarction or infection

Trinucleotide cassettes increase diversity of T7 phage-displayed peptide library

<p>Abstract</p> <p>Background</p> <p>Amino acid sequence diversity is introduced into a phage-displayed peptide library by randomizing library oligonucleotide DNA. We recently evaluated the diversity of peptide libraries displayed on T7 lytic phage and M13 filamentous phage and showed that T7 phage can display a more diverse amino acid sequence repertoire due to differing processes of viral morphogenesis.</p> <p>Methods</p> <p>In this study, we evaluated and compared the diversity of a 12-mer T7 phage-displayed peptide library randomized using codon-corrected trinucleotide cassettes with a T7 and an M13 12-mer phage-displayed peptide library constructed using the degenerate codon randomization method.</p> <p>Results</p> <p>We herein demonstrate that the combination of trinucleotide cassette amino acid codon randomization and T7 phage display construction methods resulted in a significant enhancement to the functional diversity of a 12-mer peptide library. This novel library exhibited superior amino acid uniformity and order-of-magnitude increases in amino acid sequence diversity as compared to degenerate codon randomized peptide libraries. Comparative analyses of the biophysical characteristics of the 12-mer peptide libraries revealed the trinucleotide cassette-randomized library to be a unique resource.</p> <p>Conclusion</p> <p>The combination of T7 phage display and trinucleotide cassette randomization resulted in a novel resource for the potential isolation of binding peptides for new and previously studied molecular targets.</p

Sources of dissolved iron to oxygen minimum zone waters on the Senegalese continental margin in the tropical North Atlantic Ocean: Insights from iron isotopes

Oxygen minimum zones (OMZs) cover extensive areas of eastern boundary ocean regions and play an important role in the cycling of the essential micronutrient iron (Fe). The isotopic composition of dissolved Fe (dFe) in shelf and slope waters on the Senegalese margin was determined to investigate the processes leading to enhanced dFe concentrations (up to 2 nM) in this tropical North Atlantic OMZ. On the shelf, the δ56Fe value of dFe (relative to the reference material IRMM-014) was as low as −0.33‰, which can be attributed to input of dFe from both reductive and nonreductive dissolution of sediments. Benthic inputs of dFe are subsequently upwelled to surface waters and recycled in the water column by biological uptake and remineralisation processes. Remineralised dFe is characterised by relatively high δ56Fe values (up to +0.41‰), and the contribution of remineralised Fe to the total dFe pool increases with distance from the shelf. Remineralisation plays an important role in the redistribution of dFe that is mainly supplied by benthic and atmospheric inputs, although dust inputs, estimated from dissolved aluminium concentrations, were low at the time of our study (2–9 nmol dFe m−2 d−1). As OMZs are expected to expand as climate warms, our data provide important insights into Fe sources and Fe cycling in the tropical North Atlantic Ocean

Ge and Si Isotope Behavior During Intense Tropical Weathering and Ecosystem Cycling

Chemical weathering of volcanic rocks in warm and humid climates contributes disproportionately to global solute fluxes. Geochemical signatures of solutes and solids formed during this process can help quantify and reconstruct weathering intensity in the past. Here, we measured silicon (Si) and germanium (Ge) isotope ratios of the soils, clays, and fluids from a tropical lowland rainforest in Costa Rica. The bulk topsoil is intensely weathered and isotopically light (mean ± 1σ: δ³⁰Si = −2.1 ± 0.3‰, δ⁷⁴Ge = −0.13 ± 0.12‰) compared to the parent rock (δ³⁰Si = −0.11 ± 0.05‰, δ⁷⁴Ge = 0.59 ± 0.07‰). Neoforming clays have even lower values (δ³⁰Si = −2.5 ± 0.2‰, δ⁷⁴Ge = −0.16 ± 0.09‰), demonstrating a whole‐system isotopic shift in extremely weathered systems. The lowland streams represent mixing of dilute local fluids (δ³⁰Si = 0.2 − 0.6‰, δ⁷⁴Ge = 2.2 − 2.6‰) with solute‐rich interbasin groundwater (δ³⁰Si = 1.0 ± 0.2‰, δ⁷⁴Ge = 4.0‰). Using a Ge‐Si isotope mass balance model, we calculate that 91 ± 9% of Ge released via weathering of lowland soils is sequestered by neoforming clays, 9 ± 9% by vegetation, and only 0.2 ± 0.2% remains dissolved. Vegetation plays an important role in the Si cycle, directly sequestering 39 ± 14% of released Si and enhancing clay neoformation in surface soils via the addition of amorphous phytolith silica. Globally, volcanic soil δ⁷⁴Ge closely tracks the depletion of Ge by chemical weathering (τGe), whereas δ³⁰Si and Ge/Si both reflect the loss of Si (τ_{Si}). Because of the different chemical mobilities of Ge and Si, a δ⁷⁴Ge‐δ³⁰Si multiproxy system is sensitive to a wider range of weathering intensities than each isotopic system in isolation

Virtual patients design and its effect on clinical reasoning and student experience : a protocol for a randomised factorial multi-centre study

Background Virtual Patients (VPs) are web-based representations of realistic clinical cases. They are proposed as being an optimal method for teaching clinical reasoning skills. International standards exist which define precisely what constitutes a VP. There are multiple design possibilities for VPs, however there is little formal evidence to support individual design features. The purpose of this trial is to explore the effect of two different potentially important design features on clinical reasoning skills and the student experience. These are the branching case pathways (present or absent) and structured clinical reasoning feedback (present or absent). Methods/Design This is a multi-centre randomised 2x2 factorial design study evaluating two independent variables of VP design, branching (present or absent), and structured clinical reasoning feedback (present or absent).The study will be carried out in medical student volunteers in one year group from three university medical schools in the United Kingdom, Warwick, Keele and Birmingham. There are four core musculoskeletal topics. Each case can be designed in four different ways, equating to 16 VPs required for the research. Students will be randomised to four groups, completing the four VP topics in the same order, but with each group exposed to a different VP design sequentially. All students will be exposed to the four designs. Primary outcomes are performance for each case design in a standardized fifteen item clinical reasoning assessment, integrated into each VP, which is identical for each topic. Additionally a 15-item self-reported evaluation is completed for each VP, based on a widely used EViP tool. Student patterns of use of the VPs will be recorded. In one centre, formative clinical and examination performance will be recorded, along with a self reported pre and post-intervention reasoning score, the DTI. Our power calculations indicate a sample size of 112 is required for both primary outcomes

Validation and justification of the phylum name Cryptomycota phyl. nov.

The recently proposed new phylum name Cryptomycota phyl. nov. is validly published in order to facilitate its use in future discussions of the ecology, biology, and phylogenetic relationships of the constituent organisms. This name is preferred over the previously tentatively proposed “Rozellida” as new data suggest that the life-style and morphology of Rozella is not representative of the large radiation to which it and other Cryptomycota belong. Furthermore, taxa at higher ranks such as phylum are considered better not based on individual names of included genera, but rather on some special characteristics – in this case the cryptic nature of this group and that they were initially revealed by molecular methods rather than morphological discovery. If the group were later viewed as a member of a different kingdom, the name should be retained to indicate its fungal affinities, as is the practice for other fungal-like protist groups

Manipulation of drugs to achieve the required dose is intrinsic to paediatric practice but is not supported by guidelines or evidence

Background: A lack of age-appropriate formulations can make it difficult to administer medicines to children. A manipulation of the dosage form may be required to achieve the required dose. This study aimed to describe medicines that are manipulated to achieve the required dose in paediatric practice.Method: A structured, undisguised observational study and postal survey. The observational study investigated drug manipulations occurring in clinical practice across three sites. The questionnaire, administered to a sample of paediatric nurses throughout the UK, surveyed manipulations conducted and nurses' experiences and views.Results: The observational study identified 310 manipulations, of which 62% involved tablets, 21% were intravenous drugs and 10% were sachets. Of the 54 observed manipulations 40 involved tablets with 65% of the tablets being cut and 30% dispersed to obtain a smaller dose. 188 manipulations were reported by questionnaire respondents, of these 46% involved tablets, 12% were intravenous drugs, and 12% were nebuliser solutions. Manipulations were predominantly, but not exclusively, identified in specialist clinical areas with more highly dependent patients. Questionnaire respondents were concerned about the accuracy of the dose achieved following manipulations and the lack of practice guidance.Conclusion: Manipulations to achieve the required dose occur throughout paediatric in-patient settings. The impact of manipulations on the efficacy of the drugs, the accuracy of the dose and any adverse effects on patients is not known. There is a need to develop evidence-based guidance for manipulations of medicines in children

New differential equations for on-shell loop integrals

We present a novel type of differential equations for on-shell loop integrals. The equations are second-order and importantly, they reduce the loop level by one, so that they can be solved iteratively in the loop order. We present several infinite series of integrals satisfying such iterative differential equations. The differential operators we use are best written using momentum twistor space. The use of the latter was advocated in recent papers discussing loop integrals in N=4 super Yang-Mills. One of our motivations is to provide a tool for deriving analytical results for scattering amplitudes in this theory. We show that the integrals needed for planar MHV amplitudes up to two loops can be thought of as deriving from a single master topology. The master integral satisfies our differential equations, and so do most of the reduced integrals. A consequence of the differential equations is that the integrals we discuss are not arbitrarily complicated transcendental functions. For two specific two-loop integrals we give the full analytic solution. The simplicity of the integrals appearing in the scattering amplitudes in planar N=4 super Yang-Mills is strongly suggestive of a relation to the conjectured underlying integrability of the theory. We expect these differential equations to be relevant for all planar MHV and non-MHV amplitudes. We also discuss possible extensions of our method to more general classes of integrals.Comment: 39 pages, 8 figures; v2: typos corrected, definition of harmonic polylogarithms adde

Re‐defining the virtual reality dental simulator: Demonstrating concurrent validity of clinically relevant assessment and feedback

Introduction Virtual reality (VR) dental simulators are gaining momentum as a useful tool to educate dental students. To date, no VR dental simulator exercise has been designed which is capable of reliably providing validated, meaningful clinical feedback to dental students. This study aims to measure the concurrent validity of the assessment, and the provision of qualitative feedback, pertaining to cavity preparations by VR dental simulators. Methods A cavity preparation exercise was created on a VR dental simulator, and assessment criteria for cavity preparations were developed. The exercise was performed 10 times in order to demonstrate a range of performances and for each, the simulator feedback was recorded. The exercises were subsequently three‐dimensionally printed and 12 clinical teachers were asked to assess the preparations according to the same criteria. Inter‐rater reliability (IRR) between clinical teachers was measured using a free‐marginal multirater kappa value. Clinical teacher assessment responses were compared with the VR simulator responses and percentage agreements calculated. Results IRR values for each exercise ranged from 0.39‐0.77 (69.39‐88.48%). The assessment of smoothness (κfree0.58, 78.79%) and ability to follow the outline (κfree0.56, 77.88%) demonstrated highest agreement between clinical teachers, whilst the assessment of undercut (κfree0.15, 57.58%) and depth (κfree 0.28, 64.09%) had the lowest agreement. The modal percentage agreement between clinical teachers and the VR simulator was, on average, 78% across all exercises. Conclusion The results of this study demonstrate that it is possible to provide reliable and clinically relevant qualitative feedback via a VR dental simulator. Further research should look to employ this technique across a broader range of exercises that help to develop other complex operative dental skills

Elementary Forms of the Metaphorical Life : Tropes at Work in Durkheim’s Theory of the Religious

Peer reviewedPostprin