Evaluation of non-additive genetic effects on carcass and meat quality traits in Korean Hanwoo cattle using genomic models

The traditional genetic evaluation methods generally consider additive genetic effects only and often ignore non-additive (dominance and epistasis) effects that may have contributed to genetic variation of complex traits of livestock species. The available dense single nucleotide polymorphisms (SNPs) panels offer to investigate the potential benefits of including non-additive genetic effects in the genomic evaluation models. Data from 16 971 genotyped (Illumina Bovine 50 K SNP chip) Korean Hanwoo cattle were used to estimate genetic variance components and prediction accuracy of genomic breeding values (GEBVs) for four carcass and meat quality traits: carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT) and marbling score (MS). Five different genetic models were evaluated through including additive, dominance and epistatic interactions (additive by additive, A × A; additive by dominance, A × D and dominance by dominance, D × D) successively in the models. The estimates of additive genetic variances and narrow sense heritabilities (ha2) were found similar across the evaluated models and traits except when additive interaction (A × A) was included. The dominance variance estimates relative to phenotypic variance ranged from 1.7-3.4% for CWT and MS traits, whereas, they were close to zero for EMA and BFT traits. The magnitude of A × A epistatic heritability (haa2) ranged between 14.8 and 27.7% in all traits. However, heritability estimates for A × D and D × D epistatic interactions (had2 and hdd2) were quite low compared to haa2 and were contributed only 0.0-9.7% of the total phenotypic variation. In general, broad sense heritability (hG2) estimates were almost twice (ranging between 0.54 and 0.68) the ha2 for all of the investigated traits. The inclusion of dominance effects did not improve the prediction accuracy of GEBV but improved 2.0-3.0% when epistatic effects were included in the model. More importantly, rank correlation revealed that partitioning of variance components considering dominance and epistatic effects in the model would enable to re-rank of top animals with better prediction of GEBV. The present result suggests that dominance and epistatic effects could be included in the genomic evaluation model for better estimates of variance components and more accurate prediction of GEBV for carcass and meat quality traits in Korean Hanwoo cattle.

High-fidelity initialization and control of electron and nuclear spins in a four-qubit register

Single electron spins bound to multi-phosphorus nuclear spin registers in silicon have demonstrated fast (0.8 ns) two-qubit [Formula: see text] gates and long spin relaxation times (~30 s). In these spin registers, when the donors are ionized, the nuclear spins remain weakly coupled to their environment, allowing exceptionally long coherence times. When the electron is present, the hyperfine interaction allows coupling of the spin and charge degrees of freedom for fast qubit operation and control. Here we demonstrate the use of the hyperfine interaction to enact electric dipole spin resonance to realize high-fidelity ([Formula: see text]%) initialization of all the nuclear spins within a four-qubit nuclear spin register. By controllably initializing the nuclear spins to [Formula: see text], we achieve single-electron qubit gate fidelities of F = 99.78 ± 0.07% (Clifford gate fidelities of 99.58 ± 0.14%), above the fault-tolerant threshold for the surface code with a coherence time of [Formula: see text].

Defining characteristics and long-term prognosis of drug-induced autoimmune-like hepatitis: A retrospective cohort study

BACKGROUND

Drug-induced autoimmune-like hepatitis (DI-AILH) is poorly defined and more data are required to better characterise and manage this disease entity.

OBJECTIVES

The aim of this study was to evaluate the clinical characteristics, histology and long-term outcomes of DI-AILH compared with idiopathic autoimmune hepatitis (AIH).

METHODS

This retrospective cohort study reviewed 28 DI-AILH and 39 AIH patients in a single centre. The new (2022) and simplified (2008) AIH histology criteria were used to assess DI-AILH.

RESULTS

DI-AILH were more likely to present with jaundice (p = 0.004) and higher bilirubin levels (p = 0.04) than AIH. AIH patients had higher rate of immunosuppression (IS) use including second- and third-line agents, though the time to reach biochemical remission were comparable. AIH patients had more advanced fibrosis than DI-AILH (Ishak fibrosis score 3.5 vs. 1.9, p < 0.0001). DI-AILH more commonly had eosinophilic aggregates (18% vs. 3%, p = 0.031) and less commonly showed plasma cell aggregates (61% vs. 97%, p < 0.001) than AIH. The simplified AIH histology criteria identified 1 atypical histology within the DI-AILH cohort, although this patient required long-term IS. The new AIH histology criteria classified 23 (82%) as likely AIH and 5 (18%) as possible AIH. Two of the possible DI-AILH did not require IS and one patient had successful IS withdrawal. Four DI-AILH patients with fibrosis stage ≤3 had successful IS withdrawal compared with none in the AIH group. Four patients underwent liver transplantation (LT) in both cohorts with significantly shorter time to LT in DI-AILH as the indication was for (sub)acute liver failure. Two DI-AILH patients died within 60 days of LT.

CONCLUSION

The new AIH histology criteria may be better at identifying DI-AILH. Immunosuppression withdrawal in those without significant fibrosis may be considered. DI-AILH is at risk of (sub)acute liver failure and early discussions with a transplant centre would be desirable.

Five-year Clinical Evaluation of Universal Adhesives in Noncarious Cervical Lesions

OBJECTIVES

To compare the clinical performance of mildly acidic universal adhesives Scotchbond Universal (SU, 3M Oral Care, St Paul, MN, USA) and Prime & Bond Elect (PBE, Dentsply Sirona, Charlotte, NC, USA) in the restoration of noncarious cervical lesions (NCCLs).

METHODS AND MATERIALS

A total of 63 patients in need of 203 NCCL restorations participated in this randomized controlled clinical trial. Notch-shaped lesions were restored with Kalore (GC Corporation, Tokyo, Japan) after application of either SU or PBE, following the etch-and-rinse (ER) or self-etch (SE) techniques. Subjects were followed up for 60 months. The focus of the statistical analyses was on the change of outcome over time as assessed by the Modified USPHS rating system (ie, Alfa vs Bravo + Charlie outcomes). Logistic regression was performed for each outcome separately with compound symmetric variance-covariance structure assumed to consider a correlation of restorations within subjects. All analyses were conducted using SAS 9.4 (SAS, Cary, NC, USA).

RESULTS

One-hundred twenty-nine teeth in 35 subjects were assessed at the 60-month follow-up. In addition, three restorations that failed prior to the 60-month evaluation, two of which were in subjects who did not present for the 60-month follow-up, were included in the statistical analysis. In total, two restorations in the SU_ER group and three restorations in the PBE_SE group failed the retention category. Statistically significant differences were obtained for the comparison of restorations in the PBE_SE and PBE_ER groups, where the former was 58% less likely to maintain a score of Alfa for marginal discoloration than the latter.

CONCLUSIONS

SU and PBE demonstrated acceptable clinical performance at 60 months with regard to restoration retention. Phosphoric-acid etching of the NCCLs prior to adhesive application significantly improved the performance of PBE in regard to marginal discoloration.

Development of obstetric-hepatology services: defining optimal care and impact of pregnancy counselling on patient experience

Objective

Prepregnancy counselling (PPC) is an important aspect of care for women with chronic liver disease (CLD) and liver transplantation (LT), yet its impact has not been well described. This study aims to assess the experience of women attending a joint obstetric-hepatology PPC clinic in a single-centre unit.

Design/methods

A retrospective questionnaire-based study in a tertiary unit within the UK where patients who attended the PPC clinic between March 2016 and July 2021 were invited to participate by filling in a questionnaire. Descriptive data and free-text content were subsequently analysed.

Results

108 women attended the PPC clinic over a 5-year period. Overall, 58/108 (54%) completed the questionnaire. Principal concerns regarding pregnancy included fears around deterioration in health (66%), maternal death (24%), pregnancy loss (66%), medication effects (60%) and disease transmission (36%). 17/58 (14%) patients felt the presence of multiple doctors was intimidating, however, perceptions improved by the end of the consultation.Overall, 44/58 (76%) respondents felt the clinic helped them reach a decision about pursuing pregnancy. Almost all respondents would recommend the clinic to others. There were no major differences in pregnancy outcomes between those that received PPC and those that did not.

Conclusion

The PPC clinic facilitates a personalised approach to care and is well received by patients with CLD/LT. It is difficult to elucidate whether attendance alone impacts on pregnancy outcomes; registry data may be better placed at addressing this important question.

O-009 Controlled ovarian stimulation (COS) protocols for assisted reproduction: a Cochrane systematic review and network meta-analysis

Study question

What is the relative effectiveness and safety of existing COS protocols for women undergoing assisted reproductive technology (ART) treatment?

Summary answer

There was no difference in live birth between all protocols, but short antagonist protocols may reduce ovarian hyperstimulation syndrome in women with predicted normal/high response.

What is known already

Controlled ovarian stimulation is an essential step in most ART cycles. It involves the administration of exogenous gonadotrophins to induce multifollicular growth, usually in addition to drugs that prevent untimely ovulation by suppressing the pituitary gland. Different treatment combinations may be used in COS. These vary according to the type of drugs administered for pituitary suppression (e.g., gonadotrophin-releasing hormone [GnRH] agonists, antagonists) and ovarian stimulation (e.g., urinary or recombinant gonadotrophins). Drug dosages, timing and routes of administration also vary between different regimens. However, there is no consensus on how the existing COS protocols rank according to their effectiveness and safety.

Study design, size, duration

We searched the following databases to November 2021: MEDLINE, EMBASE, CINAHL, CENTRAL and ClinicalTrials.gov. We included randomised controlled trials (RCTs) comparing at least two COS protocols using GnRH agonists or antagonists for pituitary suppression; and human menopausal gonadotrophin (hMG), urinary or recombinant follicle-stimulating hormone (u/rFSH), with or without luteinising hormone (LH) for ovarian stimulation. The primary outcomes were the rates of live birth (LBR) and ovarian hyperstimulation syndrome (OHSS) per participant after one stimulation cycle.

Participants/materials, setting, methods

Two reviewers independently selected studies and extracted data. We conducted pairwise and network meta-analyses (NMA) according to participants’ predicted response to COS (normal, high and low). Using the Cochrane-RoB-1 tool, we restricted our primary analyses to RCTs at low risk of selection and other biases. We presented effect estimates as risk ratio (RR) with 95% confidence interval (CI) and considered I2&gt;50% as representing substantial heterogeneity. For each outcome, we generated ranking plots comparing different interventions.

Main results and the role of chance

In total, our searches identified 9464 studies. The primary analysis included 68 RCTs assessing 17861 women and 34 different COS protocols. The evidence showed that in women with predicted normal or high response, the use of short GnRH antagonist protocols may result in little to no difference in LBR (RR 0.98, 95% CI 0.85 to 1.13; 6 studies; 2063 women; I2 = 0%; low-certainty evidence) and a reduction in OHSS (RR 0.88, 95% CI 0.78 to 0.99; 7 studies; 2246 women; I2 = 0%; low-certainty evidence) compared with long GnRH agonist protocols. The rankogram comparing different COS protocols showed a probability of 98% that short GnRH antagonist regimens are the best treatment to prevent OHSS. Sensitivity analyses including all studies showed that in women with predicted normal response undergoing long GnRH agonist cycles for pituitary suppression, the use of rFSH for ovarian stimulation may result in decreased fresh-cycle LBR compared to hMG (RR 0.80, 95% CI 0.68 to 0.95; 7 studies; 1575 women; I2 = 1%; low-certainty evidence). For the remaining interventions (e.g., agonist flare or progestogens for pituitary suppression, in combination with various gonadotrophin regimens) the evidence was uncertain of an effect or insufficient for quantitative synthesis.

Limitations, reasons for caution

The high number of interventions resulted in disconnected networks, limiting our ability to perform NMA for some comparisons. The certainty of the evidence was limited by serious risk of bias. Finally, the lack of data on cumulative LBR and differences in oocyte yield made comparisons between FSH preparations potentially unbalanced.

Wider implications of the findings

Our findings suggest that the use of short GnRH antagonist protocols may result in reduced OHSS rates in women with predicted normal or high ovarian response without compromising live birth rates. There is a paucity of high-quality RCTs comparing different gonadotrophin preparations (e.g., hMG versus rFSH) for COS.

Trial registration number

N/A

Engineering topological states in atom-based semiconductor quantum dots

The realization of controllable fermionic quantum systems via quantum simulation is instrumental for exploring many of the most intriguing effects in condensed-matter physics^1–3. Semiconductor quantum dots are particularly promising for quantum simulation as they can be engineered to achieve strong quantum correlations. However, although simulation of the Fermi–Hubbard model⁴ and Nagaoka ferromagnetism⁵ have been reported before, the simplest one-dimensional model of strongly correlated topological matter, the many-body Su–Schrieffer–Heeger (SSH) model^6–11, has so far remained elusive—mostly owing to the challenge of precisely engineering long-range interactions between electrons to reproduce the chosen Hamiltonian. Here we show that for precision-placed atoms in silicon with strong Coulomb confinement, we can engineer a minimum of six all-epitaxial in-plane gates to tune the energy levels across a linear array of ten quantum dots to realize both the trivial and the topological phases of the many-body SSH model. The strong on-site energies (about 25 millielectronvolts) and the ability to engineer gates with subnanometre precision in a unique staggered design allow us to tune the ratio between intercell and intracell electron transport to observe clear signatures of a topological phase with two conductance peaks at quarter-filling, compared with the ten conductance peaks of the trivial phase. The demonstration of the SSH model in a fermionic system isomorphic to qubits showcases our highly controllable quantum system and its usefulness for future simulations of strongly interacting electrons.

Precision-engineered devices consisting of a linear array of ten quantum dots are used to realize both the trivial and topological phases of the many-body Su–Schrieffer–Heeger model.

Managing hepatic complications of pregnancy: practical strategies for clinicians

Liver disorders specific to pregnancy are rare but can have potentially serious consequences for mother and fetus. Pregnancy-related liver disorders are the most common cause of liver disease in otherwise healthy pregnant women and pose a challenge to physicians because of the need to take into account both maternal and fetal health. A good knowledge of these disorders is necessary as prompt diagnosis and appropriate management results in improved maternal and fetal outcomes. This review will focus on pregnancy-specific disorders and will aim to serve as a guide for physicians in their diagnosis, management and subsequent monitoring.

Effect of total cholesterol level variabilities on cerebrovascular disease

OBJECTIVE

Hyperlipidemia is a risk factor of cerebrovascular disease (CVD). However, the relationship between CVD and cholesterol variability is less clear. This study assesses the relationship between cholesterol change and CVD risk.

PATIENTS AND METHODS

We reviewed 480,830 people from 20 to 99 years with 2 health check-ups from 2002 to 2015 from the Korean National Health Insurance (KNHI) database. People's baseline and follow-up cholesterol levels were classified into low (<180 mg/dL), moderate (≥180 mg/dL and <240 mg/dL), and high (≥240 mg/dL). Participants were divided into 9 groups (low-to-low, low-to-moderate, low-to-high, moderate-to-low, moderate-to-moderate, moderate-to-high, high-to-low, high-to-moderate, high-to-high).

RESULTS

Low to high cholesterol level is associated with hemorrhagic stroke (aHR1 = 1.59; 95% CI 1.12-2.28 and aHR2 = 1.56; 95% CI 1.07-2.25). Low to moderate/high cholesterol level is associated with ischemic stroke and occlusion/stenosis (for low to moderate, aHR1 = 1.11; 95% CI 1.04-1.17 and aHR2 = 1.14; 95% CI 1.07-1.21 for ischemic stroke and aHR1 = 1.18; 95% CI 1.07-1.29 and aHR2 = 1.20; 95% CI 1.08-1.32 for occlusion/stenosis, for low to high, aHR1 = 1.42; 95% CI 1.20-1.67 and aHR2 = 1.28; 95% CI 1.08-1.52 for ischemic stroke and aHR1 = 1.86; 95% CI 1.46-2.36 and aHR2= 1.74; 95% CI 1.36-2.23 for occlusion/stenosis). Moderate to high cholesterol level is associated with ischemic stroke and occlusion/stenosis (for ischemic stroke, aHR1 = 1.12; 95% CI 1.05-1.20 and aHR2 = 1.10; 95% CI 1.03-1.17, for occlusion/stenosis, aHR1 = 1.21; 95% CI 1.10-1.33 and aHR2 = 1.19; 95% CI 1.08-1.32). Moderate to low cholesterol level is associated with ischemic and hemorrhagic stroke and occlusion/stenosis (for ischemic, aHR1 = 1.15; 95% CI 1.09-1.21, for hemorrhagic, aHR1 = 1.14; 95% CI 1.01-1.28, for occlusion/stenosis, aHR1 = 1.14; 95% CI 1.05-1.23). High to low cholesterol level is associated with ischemic stroke and occlusion/stenosis (for ischemic stroke, aHR1 = 1.51; 95% CI 1.33-1.71 and aHR2 = 1.20; 95% CI 1.05-1.36, for occlusion/stenosis, aHR1 = 1.50; 95% CI 1.24-1.81).

CONCLUSIONS

Our study shows that cholesterol changes, especially larger changes, lead to an increase in CVD, which demonstrates that cholesterol variability may increase CVD.

Reducing inappropriate blood testing in haematology inpatients: A multicentre quality improvement project

Haematology inpatients are subject to extensive blood testing and many of these tests could be deemed inappropriate as they are not indicated for monitoring or clinical symptoms. Unnecessary testing exposes the patient to the risks of phlebotomy and adds resources' strain to the NHS.Our aim was to reduce the number of inappropriate blood tests performed on haematology inpatient wards.Quality improvement projects (QIPs) were performed in four haematology units introducing inpatient blood testing schedules (BTS) or providing staff education on current schedules.A reduction in inappropriate or overall blood testing was achieved at every site where a BTS was implemented, with a median reduction in inappropriate blood testing of 24.7% and estimated cost savings of up to £38,438 per annum.This QIP can be safely adapted to a variety of inpatient settings and is associated with cost savings. This initiative could be extended to other inpatient departments throughout the NHS.

An update on the pharmacological management of autoimmune hepatitis

Introduction: Autoimmune hepatitis (AIH) is an immune mediated, inflammatory disease affecting the liver as a result of environmental triggers in susceptible individuals leading to loss of self-tolerance. The immunopathogenesis of AIH is not fully understood, which limits targeted therapeutic options.Areas covered: In this review, the authors provide an overview of current practice in the management of AIH, which include induction therapy with corticosteroids (± thiopurines), followed by maintenance therapy. Lack of early response to treatment may serve as a predictor of those at risk of requiring treatment escalation to second- and third-line agents such as mycophenolate mofetil (MMF), calcineurin inhibitors or biologics. Evidence for third-line agents from small retrospective studies or individual centers are reviewed. The nuances of AIH treatment in pregnancy, overlap syndromes, and drug induced liver injury (DILI) warrant further consideration.Expert opinion: Augmenting the balance of regulatory T cells (Treg) and effector T cells is an appealing therapeutic target with a multitude of agents in development. Many of the challenges in AIH research are due to its rarity and lack of randomized data. Management of AIH should strive towards individualized care through risk stratification and use of the best therapeutic modality for each patient.

Highlights of the updated Dutch evidence- and consensus-based guideline on psoriasis 2017

Linked Comment: https://doi.org/10.1111/bjd.17390.

Poor agreement between the automated risk assessment of a smartphone application for skin cancer detection and the rating by dermatologists

Background

Several smartphone applications (app) with an automated risk assessment claim to be able to detect skin cancer at an early stage. Various studies that have evaluated these apps showed mainly poor performance. However, all studies were done in patients and lesions were mainly selected by a specialist.

Objectives

To investigate the performance of the automated risk assessment of an app by comparing its assessment to that of a dermatologist in lesions selected by the participants.

Methods

Participants of a National Skin Cancer Day were enrolled in a multicentre study. Skin lesions indicated by the participants were analysed by the automated risk assessment of the app prior to blinded rating by the dermatologist. The ratings of the automated risk assessment were compared to the assessment and diagnosis of the dermatologist. Due to the setting of the Skin Cancer Day, lesions were not verified by histopathology.

Results

We included 125 participants (199 lesions). The app was not able to analyse 90 cases (45%) of which nine BCC, four atypical naevi and one lentigo maligna. Thirty lesions (67%) with a high and 21 with a medium risk (70%) rating by the app were diagnosed as benign naevi or seborrhoeic keratoses. The interobserver agreement between the ratings of the automated risk assessment and the dermatologist was poor (weighted kappa = 0.02; 95% CI −0.08‐0.12; P = 0.74).

Conclusions

The rating of the automated risk assessment was poor. Further investigations about the diagnostic accuracy in real‐life situations are needed to provide consumers with reliable information about this healthcare application.

Eighteen-month Clinical Study of Universal Adhesives in Noncarious Cervical Lesions

OBJECTIVE

To evaluate the clinical performance of Scotchbond Universal (3M Oral Care) and Prime & Bond Elect (Dentsply Sirona) in the restoration of noncarious cervical lesions (NCCLs).

METHODS AND MATERIALS

This was a randomized controlled clinical trial involving 63 subjects. Two hundred and three NCCLs were restored using Scotchbond Universal and Prime & Bond Elect using both an etch-and-rinse and a self-etch technique. Lesions were notch-shaped NCCLs, and the restorations were placed without any mechanical retention. Restorations were finished immediately after placement and scored with regard to retention, marginal discoloration, marginal adaptation, and secondary caries. Similar assessment of the restorations was performed 18 months after placement. Logistic regression was performed for each outcome separately with a compound symmetric variance-covariance structure assumed to consider a correlation of restorations within subjects. All analyses were conducted using SAS version 9.4 (SAS Inc).

RESULTS

One hundred and fifty-eight teeth (77.8% of the restorations placed) in 46 subjects (73% of subjects enrolled) were available for the 18-month follow-up. A statistically significant difference was reached only for the comparison Scotchbond Universal/self-etch (SU_SE) and Prime & Bond Elect/etch-and-rinse (PBE_E&R) groups ( p=0.01), where a restoration with SU_SE was 66% less likely to maintain a score of Alpha for marginal discoloration than a restoration performed with PBE_E&R.

CONCLUSIONS

Scotchbond Universal and Prime & Bond Elect presented acceptable clinical performance after 18 months of clinical service. However, Scotchbond Universal, when applied with a self-etch approach, did demonstrate a relatively high level of marginal discoloration when compared to the other groups.

Automatic Detection of Cow's Oestrus in Audio Surveillance System

Early detection of anomalies is an important issue in the management of group-housed livestock. In particular, failure to detect oestrus in a timely and accurate way can become a limiting factor in achieving efficient reproductive performance. Although a rich variety of methods has been introduced for the detection of oestrus, a more accurate and practical method is still required. In this paper, we propose an efficient data mining solution for the detection of oestrus, using the sound data of Korean native cows (Bos taurus coreanea). In this method, we extracted the mel frequency cepstrum coefficients from sound data with a feature dimension reduction, and use the support vector data description as an early anomaly detector. Our experimental results show that this method can be used to detect oestrus both economically (even a cheap microphone) and accurately (over 94% accuracy), either as a standalone solution or to complement known methods.

Cyclosporine A up-regulates Sonic hedgehog in gingiva: role of the up-regulation on gingival cell proliferation

BACKGROUND AND OBJECTIVE

Sonic hedgehog protein (SHH) is a mitogen that stimulates cell proliferation. Cyclosporine A enhances the proliferation of gingival cells; however, the relationships of SHH to cyclosporine A or to cyclosporine A-enhanced gingival cell proliferation have not been described.

MATERIAL AND METHODS

Here, we investigated SHH expression in gingiva in vitro and in vivo after cyclosporine A treatment and tested the effect of SHH inhibition on cyclosporine A-enhanced gingival fibroblast proliferation in vitro.

RESULTS

In human gingival fibroblasts, cyclosporine A treatment increased the expression of SHH transcripts and SHH protein, and stimulated cell proliferation; the addition of cyclopamine, an SHH signaling inhibitor, suppressed cyclosporine A-enhanced cell proliferation. Up-regulated expression of SHH and up-regulation of proliferating cell nuclear antigen transcripts and protein were observed in the edentulous gingiva of cyclosporine A-treated rats.

CONCLUSION

Cyclosporine A up-regulates gingival SHH expression in vitro and in vivo, and the inhibition of the SHH pathway counteracts the stimulatory effect of cyclosporine A on gingival fibroblast proliferation. Therefore, we suggest that SHH mediates a novel molecular mechanism for cyclosporine A-induced gingival complications.

A Feasibility Study of a Tilted Head Position in Helical Tomotherapy for Fractionated Stereotactic Radiotherapy of Intracranial Malignancies

Herein, we evaluated the feasibility of placing patients in a tilted head position as part of routine clinical practice for fractionated stereotactic radiotherapy (FSRT) of intracranial tumors using helical tomotherapy (HT), by assessing its dosimetric benefit and setup accuracy. We reviewed treatment plans of four cases that were to receive FSRT for brain lesions in normal and head-tilted positions. These patients underwent two computed tomography (CT) scans: first in the normal supine position and then in the supine position with the head tilted at a 458 angle. Two separate HT plans for each position were generated in these four patients, using the same planning parameters. Plans were compared for target conformity and dose homogeneity. Maximum and average doses to critical organs, including normal brain, brain stem, optic chiasm, optic nerves, and the eyes, were considered. To evaluate setup accuracy, patient movement during treatment was assessed by post-treatment megavoltage CT scans. Both HT plans achieved similar conformal and homogeneous dose coverage to the target. Head-tilted HT delivered lower average and maximum doses to critical organs in the cases where the tumor was located on the same plane with critical organs, particularly when they were not directly attached. Placement in the head-tilted position without a mouthpiece allowed for increased patient movement during treatment, while use of a mouthpiece reduced patient movement to even less than that observed for normal setup in the supine position. This pilot study showed that placement in a tilted head position for FSRT of intracranial tumors using HT may be of clinical use, but depends on the tumor location.

Saving the NHS one blood test at a time

As a team of junior doctors our aim has been to save costs in day to day work so that money can be reallocated to improving nursing staff levels on our wards. Stem cell units have regular blood collection schedules in order to monitor organ response to chemotherapy and to look for complications in immunocompromised patients. We set out to reduce the number of biochemical investigations to a minimum that would be clinically indicated. We designed a new blood collection proforma for nursing staff to follow and audited all blood tests taken during a 2 week period before and after its introduction. The number of inappropriate blood tests were recorded as those that were not clinically indicated or not present on the collection schedule. After the introduction of the change the number of inappropriate tests were reduced by 937 over the 2 week period, with a cost saving of £1,478.42. Similar strategies for reducing unnecessary investigations and focusing on tests that will change management could help the NHS cope with a difficult financial future and provide continued safe staffing levels and quality care.

Multi-valued logic gates based on ballistic transport in quantum point contacts

Multi-valued logic gates, which can handle quaternary numbers as inputs, are developed by exploiting the ballistic transport properties of quantum point contacts in series. The principle of a logic gate that finds the minimum of two quaternary number inputs is demonstrated. The device is scalable to allow multiple inputs, which makes it possible to find the minimum of multiple inputs in a single gate operation. Also, the principle of a half-adder for quaternary number inputs is demonstrated. First, an adder that adds up two quaternary numbers and outputs the sum of inputs is demonstrated. Second, a device to express the sum of the adder into two quaternary digits [Carry (first digit) and Sum (second digit)] is demonstrated. All the logic gates presented in this paper can in principle be extended to allow decimal number inputs with high quality QPCs.

Charge frustration in a triangular triple quantum dot

We experimentally investigate the charge (isospin) frustration induced by a geometrical symmetry in a triangular triple quantum dot. We observe the ground-state charge configurations of sixfold degeneracy, the manifestation of the frustration. The frustration results in omnidirectional charge transport, and it is accompanied by nearby nontrivial triple degenerate states in the charge stability diagram. The findings agree with a capacitive interaction model. We also observe unusual transport by the frustration, which might be related to elastic cotunneling and the interference of trajectories through the dot. This work demonstrates a unique way of studying geometrical frustration in a controllable way.