Rectal Foreign Bodies: Surgical Management and the Impact of Psychiatric Illness.

Background Entrapped rectal foreign bodies can be a challenge to manage and are being encountered by acute surgical teams with increasing frequency. The aims of our study were to (a) ascertain the population demographics of patients presenting with this problem in our local area of East Kent, (b) see if an association could be drawn between this presentation and proposed risk factors such as a psychiatric illness or socioeconomic deprivation, and (c) to review how foreign bodies are being removed in the East Kent Hospital University Foundation NHS Trust, United Kingdom and to highlight best practice with regards to this in line with the latest guidelines. Methodology Between 2017 and 2021, 32 cases of entrapped rectal foreign bodies were diagnosed and managed at our NHS Trust. Retrospective data taken from the theatre directory and electronic patient records were used to audit patient demographics, co-morbidities, the type of foreign body, and the extraction technique. Results The majority of patients (90%) were male (n = 29). The patients' age ranged from 15 to 95 years, with a median age of 48 years. In total, 12 (37.5%) patients had a medical history of a psychiatric illness. The most common foreign bodies removed were sex toys or vibrators (n = 8) and roll-on deodorant bottles (n = 7). Kent Area B (n = 10) and Kent Area A (n = 9) were the areas with the highest number of cases. Twenty-two (68.8%) patients underwent examination under a general anaesthetic for removal, seven (21.8%) patients had the object manually removed without sedation, and three (9.4%) required a laparotomy with or without bowel resection. Conclusions Cases of an entrapped rectal foreign body in this local region typically involved male patients between 40 and 50 years old. A high proportion of this group had a history of a psychiatric illness supporting an association between this presentation and mental health. We have proposed some explanations for this association including the anal canal nervous system interplay with the "brain-gut axis." Lower socioeconomic status and unemployment may also be risk factors for this surgical problem. A trans-anal approach for management is successful in the majority of cases; however, almost 10% of patients required emergency surgical management. We have highlighted best practice guidelines for the investigation and management of the entrapped rectal foreign body as part of our discussion.

Anisotropy-driven quantum criticality in an intermediate valence system.

Intermetallic compounds containing f-electron elements have been prototypical materials for investigating strong electron correlations and quantum criticality (QC). Their heavy fermion ground state evoked by the magnetic f-electrons is susceptible to the onset of quantum phases, such as magnetism or superconductivity, due to the enhanced effective mass (m*) and a corresponding decrease of the Fermi temperature. However, the presence of f-electron valence fluctuations to a non-magnetic state is regarded an anathema to QC, as it usually generates a paramagnetic Fermi-liquid state with quasiparticles of moderate m*. Such systems are typically isotropic, with a characteristic energy scale T0 of the order of hundreds of kelvins that require large magnetic fields or pressures to promote a valence or magnetic instability. Here we show the discovery of a quantum critical behaviour and a Lifshitz transition under low magnetic field in an intermediate valence compound α-YbAlB4. The QC origin is attributed to the anisotropic hybridization between the conduction and localized f-electrons. These findings suggest a new route to bypass the large valence energy scale in developing the QC.

Cost Implications of Reactive Versus Prospective Testing for Dihydropyrimidine Dehydrogenase Deficiency in Patients With Colorectal Cancer: A Single-Institution Experience.

BACKGROUND: Severe toxicity is experienced by a substantial minority of patients receiving fluoropyrimidine-based chemotherapy, with approximately 20% of these severe toxicities attributable to polymorphisms in the DPYD gene. The DPYD codes for the enzyme dihydropyrimidine dehydrogenase (DPD) important in the metabolism of fluoropyrimidine-based chemotherapy. We questioned whether prospective DPYD mutation analysis in all patients commencing such therapy would prove more cost-effective than reactive testing of patients experiencing severe toxicity. METHODS: All patients experiencing severe toxicity from fluoropyrimidine-based chemotherapy for colorectal cancer in an Irish private hospital over a 3-year period were tested for 4 DPYD polymorphisms previously associated with toxicity. The costs associated with an index admission for toxicity in DPD-deficient patients were examined. A cost analysis was undertaken comparing the anticipated cost of implementing screening for DPYD mutations versus current usual care. One-way sensitivity analysis was conducted on known input variables. An alternative scenario analysis from the perspective of the Irish health-care payer (responsible for public hospitals) was also performed. RESULTS: Of 134 patients commencing first-line fluoropyrimidine chemotherapy over 3 years, 30 (23%) patients developed grade 3/4 toxicity. Of these, 17% revealed heterozygote DPYD mutations. The cost of hospitalization for the DPYD-mutated patients was €232 061, while prospectively testing all 134 patients would have cost €23 718. Prospective testing would result in cost savings across all scenarios. CONCLUSIONS: The cost of hospital admission for severe chemotherapy-related toxicity is significantly higher than the cost of prospective DPYD testing of each patient commencing fluoropyrimidine chemotherapy.

Scaling of Majorana Zero-Bias Conductance Peaks.

We report an experimental study of the scaling of zero-bias conductance peaks compatible with Majorana zero modes as a function of magnetic field, tunnel coupling, and temperature in one-dimensional structures fabricated from an epitaxial semiconductor-superconductor heterostructure. Results are consistent with theory, including a peak conductance that is proportional to tunnel coupling, saturates at 2e^{2}/h, decreases as expected with field-dependent gap, and collapses onto a simple scaling function in the dimensionless ratio of temperature and tunnel coupling.

Transport properties of pristine few-layer black phosphorus by van der Waals passivation in an inert atmosphere.

Ultrathin black phosphorus is a two-dimensional semiconductor with a sizeable band gap. Its excellent electronic properties make it attractive for applications in transistor, logic and optoelectronic devices. However, it is also the first widely investigated two-dimensional material to undergo degradation upon exposure to ambient air. Therefore a passivation method is required to study the intrinsic material properties, understand how oxidation affects the physical properties and enable applications of phosphorene. Here we demonstrate that atomically thin graphene and hexagonal boron nitride can be used for passivation of ultrathin black phosphorus. We report that few-layer pristine black phosphorus channels passivated in an inert gas environment, without any prior exposure to air, exhibit greatly improved n-type charge transport resulting in symmetric electron and hole transconductance characteristics.