Inkjet printing and electrical characterisation of DNA-templated cadmium sulphide nanowires.

Cadmium sulphide can be templated on λ-DNA molecules to form an aqueous dispersion of CdS/λ-DNA nanowires. Subsequent addition of ethylene glycol to 50% v/v is sufficient to formulate an ink suitable for printing using piezoelectric drop-on-demand technology. Printed droplet arrays show a coffee-ring morphology of individual deposits by fluorescence and Raman microscopy, but upon increasing the number of layers of printed material by repeated printing over each droplet, the dry deposit approaches closer to a disc shape. It is also possible to print parallel tracks by reducing the droplet separation in the array until neighbouring droplets overlap before they dry. The droplets coalesce to form a strip of width roughly equal to the diameter of the droplets. Evaporation-driven capillary flow sends the nanowires to the edges of the strip and when dry they form parallel tracks of CdS/λ-DNA nanowire bundles. Both droplets and tracks were printed onto Pt-on-glass interdigitated microelectrodes (10 µm width, 10 µm gap). The current-voltage characteristics of these two-terminal devices were approximately ohmic, but with some hysteresis. The conductance increased with temperature as a simple activated process with activation energies of 0.57 ± 0.02 eV (tracks) and 0.39 ± 0.02 eV (droplets). The impedance spectra of the printed films were consistent with hopping between CdS grains.

The theory of a trapped degenerate mode resonator.

Resonance based biosensors are used in the detection of biological molecules for medical diagnostics. Sensing in a liquid environment is very desirable for this application, but presents a significant challenge for resonators based upon conventional technologies. In this paper, the major originality lies in the development and exposition of a fundamental theory enabling design of an original elastic resonant sensor whose modes are engineered to simultaneously possess three separate but complementary dynamical properties: namely, (1) in-plane displacement of the free interface whereby the SH waves are uncoupled from the SV and P waves; (2) intrinsic modal trapping; and finally, (3) cyclic symmetry and modal degeneracy. The modal trapping is due to the physical configuration of the resonator resulting in an imaginary wavenumber for one region of the resonator. The wave will be evanescent in this region and propagating elsewhere. The fundamental principles are elucidated, and analytical techniques are presented that facilitate the efficient design of this unique class of device.

Antibiotic stewardship for reptiles.

This review discusses the general principles underlying responsible antibiotic usage in reptiles. Very little evidence underlies antibiotic usage in reptiles, and there are no published guidelines for responsible antibiotic usage. A literature search was performed to review the evidence for bacterial involvement in the pathology of selected common diseases of reptiles, allowing the development of recommendations for responsible antibiotic treatment of those diseases.

Effect of retinal and/or extra-retinal information on age in memory-guided saccades.

The aim of the study was to determine whether the addition of retinal or extra-retinal information could be used to improve memory-guided saccadic performance in healthy participants. Furthermore, we included two age groups in our study; healthy young adult subjects (mean age 20 years) and healthy middle-aged adult subjects (mean age 52 years). All subjects performed a novel task that incorporated a Go/NoGo task with a memory-guided saccade paradigm to investigate whether extra-retinal information (making a saccade towards the visible target) or retinal (a visible frame-of-reference) has any affect on the accuracy or variability of the response. We found all subjects made slight hypometric responses to the memory-guided targets. Both younger and middle-aged subjects revealed an increase in accuracy in the Go task compared with the NoGo task and the framed condition compared to the frameless condition, respectively. The frame also revealed a significant decrease in variability in the memory-guided saccades. A positive correlation in errors between the 1st and 2nd saccade in the Go task was revealed for all subjects; however, the older subjects revealed a greater correlation than younger subjects. The results presented indicate that younger and middle-aged perform highly similar patterns of errors during eye movements to remembered locations. However, middle-aged subjects show a greater tendency to use extra-retinal and retinal feedback to guide the response.

Athletes and the Aorta: Normal Adaptations and the Diagnosis and Management of Pathology.

OPINION STATEMENT: Over a hundred years ago, physicians first recognized that participation in regular, vigorous training resulted in enlargement of the heart. Since that time, the term "athlete's heart" has entered the medical lexicon as a global expression encompassing the electrical, functional, and morphological adaptations that develop in response to physical training. Exercise-induced adaptations of the aorta, which is also exposed to large hemodynamic stresses during prolonged endurance exercise or resistance training, are less well recognized. Young athletes tend to have slightly larger aortas than their sedentary counterparts; however, this rarely exceeds normal ranges for the general population. A systematic approach is advised when presented with an athlete with aortic enlargement. The size of the aorta needs to be first put in the context of the athlete's age, sex, size, and sporting endeavors; however, even in the largest young athletes, the aortic root rarely exceeds 4 cm in men or 3.4 cm in women. A comprehensive evaluation is advised which includes a detailed family history and a thorough physical examination evaluating for signs of any defined connective tissue disorder associated with aortopathy. Downstream testing is then tailored for the individual and may include further tomographic imaging, opthalmology review, and genetic testing. This should ideally be performed at a specialist center. Management of athletes with an aortopathy includes tailoring athletic activity, medical management with strict impulse control, and, in some cases, prophylactic surgery. The issue of sporting eligibility should be individualized and if disqualification is necessary, this should be undertaken by a sports cardiologist or an expert in aortic disease with experience in dealing with an athletic population.

Analysis of millimetre-wave polarization diverse multiple-input multiple-output capacity.

Millimetre-waves offer the possibility of wide bandwidth and consequently high data rate for wireless communications. For both uni- and dual-polarized systems, signals sent over a link may suffer severe degradation due to antenna misalignment. Orientation robustness may be enhanced by the use of mutual orthogonality in three dimensions. Multiple-input multiple-output polarization diversity offers a way of improving signal reception without the limitations associated with spatial diversity. Scattering effects often assist propagation through multipath. However, high path loss at millimetre-wave frequencies may limit any reception enhancement through scattering. We show that the inclusion of a third orthogonal dipole provides orientation robustness in this setting, as well as in a rich scattering environment, by means of a Rician fading channel model covering all orientations for a millimetre-wave, tri-orthogonal, half-wave dipole transmitter and receiver employing polarization diversity. Our simulation extends the analysis into three dimensions, fully exploiting individual sub-channel paths. In both the presence and absence of multipath effects, capacity is observed to be higher than that of a dual-polarized system over the majority of a field of view.

Familial hypouricaemia associated with renal tubular uricosuria and uric acid calculi: case report.

We describe a patient with the rare combination of uric acid calculi, familial hypouricaemia, and increased renal urate clearance.

HUMTH01 validation studies: effect of substrate, environment, and mixtures.

New DNA typing methods need to be thoroughly validated prior to use in forensic investigation. This includes determining the effects different sample conditions have on the typeability of those samples. Biological samples routinely encountered in forensic case work were exposed to a series of different substrates, environmental conditions, and mixtures and typed for the STR HUMTH01 using PCR. None of the conditions resulted in a false typing or preferential allele amplification. It is demonstrated that the application of HUMTH01 typing methods in forensic case work can be reliable, robust, and efficient.

Unilateral breast-feeding: a new clue to the diagnosis of thyrotoxicosis.

Two thyrotoxic women who had breast-fed exclusively at the right breast are reported. This phenomenon may prove to be a useful clue to undiagnosed thyrotoxicosis in the postpartum period.

Conjugal thyroid disease--six couples with thyrotoxicosis, one couple with hypothyroidism, and one couple with thyroid cancer.

Six married couples with thyrotoxicosis, one couple with primary hypothyroidism, and one couple with well differentiated thyroid cancer are reported. The occurrence of conjugal thyroid disease raises the possibility that environmental factors may have played an aetiological role.

Cloacal prolapses in reptiles: a retrospective study of 56 cases.

OBJECTIVES: To review the types of cloacal prolapses seen in reptiles and to investigate potential risk factors which may be associated with the presence of a cloacal prolapse. METHOD: Retrospective review of medical records of all reptile cases evaluated at the Royal (Dick) School of Veterinary Studies between 1999 and 2013; only cases which had a history of cloacal prolapse were included in the study. RESULTS: Prolapses were identified in 56 of 3019 (1·9%) reptiles examined over the study period. Prolapses were 3·47 times as likely in chelonians and lizards compared to snakes. There were no statistically significant differences between the prevalence of prolapses in males and females. Females were 7·5 times more likely to present with a true cloacal prolapse involving no other organs compared to males, and were 4·83 times more likely to present with a prolapse of the colon. CLINICAL SIGNIFICANCE: These results suggest that cloacal prolapses are not a common occurrence but that species and sex may both influence the prevalence and type of cases seen.

Husbandry risk factors associated with hock pododermatitis in UK pet rabbits (Oryctolagus cuniculus).

Pododermatitis, often called 'sore hocks', is a chronic, granulomatous, ulcerative dermatitis which most commonly affects the plantar aspect of the caudal metatarsal and tarsal areas. Pododermatitis is a common clinical finding in the pet rabbit population, but no data is available regarding the actual prevalence of this condition in the UK pet rabbit population or possible husbandry-related factors which may predispose pet rabbits to development of this condition. It was the aim of this study to determine the prevalence of pododermatitis within a sample pet rabbit population, and study possible correlations with husbandry, sex, breed and origin of the rabbits. Findings suggested that young rabbits are at a lower risk of pododermatitis compared with older rabbits; female domestic rabbits are more predisposed to pododermatitis than males; and 100 per cent of the neutered females examined showed clinical evidence of pododermatitis. The effect that different types of bedding may have on the prevalence of pododermatitis was also investigated. This study also produced a scoring system which can be used to score clinical cases. Our study is of clinical importance because it helps to recognise many of the factors which predispose pet rabbits to pododermatitis, representing the first step towards increased awareness of this extremely common problem.

The effects of UV light on calcium metabolism in ball pythons (Python regius).

Despite the popularity of keeping snakes in captivity, there has been limited investigation into the effects of UV radiation on vitamin D levels in snakes. The aim of this study was to investigate the effects of UV-b radiation on plasma 25-hydroxyvitamin D3 levels and ionised calcium concentrations in ball pythons (Python regius). Blood samples were taken from 14 ball pythons, which had never been exposed to UV-b light, to obtain baseline 25-hydroxyvitamin D3 levels and ionised calcium concentrations. Blood samples were then taken again from the same snakes 70 days later after one group (Group 1, n=6 females) were exposed to UV-b radiation daily, and the other group (Group 2, n=5 males and 3 females) were exposed to no UV-b radiation. Mean±sd 25-hydroxyvitamin D3 levels on day 0 in Group 1 were 197±35 nmol/l, and on day 70 were 203.5±13.8 nmol/l. Mean±sd 25-hydroxyvitamin D3 levels in Group 2 on day 0 were 77.7±41.5 nmol/l, and on day 70 were 83.0±41.9 nmol/l. Mean±sd ionised calcium levels at day 0 were 1.84±0.05 mmol/l for Group 1, and on day 70 were 1.78±0.07 mmol/l. Mean±sd ionised calcium levels at day 0 were 1.79±0.07 mmol/l for Group 2, and on day 70 were 1.81±0.05 mmol/l. No association was demonstrated between exposure to UV-b radiation and plasma 25-hydroxyvitamin D3 and ionised calcium concentrations. These results may provide baseline parameters for future studies in this and other snake species to determine ability to utilise UV-b light for vitamin D production.

The use of negative pressure wound therapy following subcarapacial abscess excision in a tortoise.

A 42-year-old female Testudo graeca was referred with a five-month history of a non-healing carapacial wound. Previous treatment had involved long-term antibiotic therapy and conscious debridement of necrotic tissue. On presentation an extensive deep wound with purulent discharge was visible on the right side of the carapace. A computed tomographic scan was performed to assess the extent of the wound. This revealed a large carapacial deficit with two underlying soft tissue masses. Surgical debridement was performed under general anaesthesia resulting in an even larger defect. Because of the extensive nature of the deficit, negative pressure wound therapy was applied to aid wound healing. A negative pressure of approximately 120 mmHg was maintained and bandages were changed every third day. Wound healing progressed rapidly and a healthy granulation bed was formed within 16 days.

Gastrointestinal parasitic burdens in UK tortoises: a survey of tortoise owners and potential risk factors.

Despite gastrointestinal parasites being commonly diagnosed in captive tortoises throughout the UK, there is a lack of data regarding the prevalence. The aims of this study were to investigate the prevalence of gastrointestinal parasites in tortoises in the UK, and to investigate the factors affecting the prevalence of these parasites. Owners were invited to submit a faecal sample from their tortoise in conjunction with a completed questionnaire covering details of signalment and husbandry. Data from the questionnaires were analysed at the end of the study. Faecal analysis was performed on samples from Testudo hermanni, Testudo graeca and Testudo horsfieldii. This involved examination of direct wet preparations, a modified McMaster technique, passive NaCl flotation and Cryptosporidium staining. Of the 142 samples used, 130 were examined by the first three methods. 49 per cent were positive for one or more parasites. Of the positive samples, 67 per cent were positive for oxyurids, 28 per cent were positive for ascarids and 28 per cent were positive for protozoa (Balantidium, Nyctotherus or flagellates). Only 1/113 (0.8 per cent) samples was positive for Cryptosporidium. The most important risk factors for parasites were sex (F) and length of time (<5 years) in owner's possession. This survey showed that gastrointestinal parasites are frequently detected in the faecal samples of captive tortoises in the UK, but their prevalence may be influenced by various factors including sex, length of time owned, age and species.

Partial ear canal ablation and lateral bulla osteotomy in rabbits.

Six lop rabbits were presented with clinical signs of otitis media or externa. The presence of disease was confirmed by computerized tomography examination, with two rabbits suffering from bilateral disease. The rabbits were anaesthetized and underwent surgery of the affected bulla. Rabbits with bilateral disease had a minimum of 2 weeks between procedures. A single vertical incision was made over the base of the vertical canal, which was bluntly dissected free from surrounding tissue. The ventral portion of the vertical canal was removed and a lateral bulla osteotomy was performed. The mucosa at the base of the dorsal vertical canal was apposed and the aural cartilage sutured to form a blind-ending pouch open at the pretragic incisure. Histopathological samples taken from the dorsal margin of the vertical canal yielded subtle and non-specific changes in the six samples submitted. All rabbits were discharged within 48 hours of surgery. The cosmetic outcome was excellent with animals retaining visually normal aural anatomy. The partial ear canal ablation/lateral bulla osteotomy procedure is quick and has a good cosmetic result when performed in rabbits.

Use of arterial blood gas analysis as a superior method for evaluating respiratory function in pet rabbits (Oryctolagus cuniculus).

A retrospective study compared invasive (arterial blood gas analysis) and non-invasive (capnography and pulse oximetry) methods of monitoring respiratory function in conscious rabbits. Arterial samples from 50 healthy dwarf lop rabbits, presenting for routine surgical neutering, were analysed on a point-of-care blood gas analysis machine. Reference intervals were obtained for pH (7.35-7.54), PaCO2 (mm Hg) (25.29-40.37), PaO2 (mm Hg) (50.3-98.2), base excess (mmol/l) (6.7-6.5), HCO3 (mmol/l) (17.96-29.41), TCO2 (mmol/l) (18.9-30.5). SaO2 (per cent) (88.8-98.0), Na (mmol/l) (137.6-145.2), K (mmol/l) (3.28-4.87), iCal (mmol/l) (1.64-1.94), glucose (mmol/l) (6.23-10.53), haematocrit (per cent) (23.3-40.2) and haemoglobin (mg/dl) (7.91-13.63). Pulse oximetry (SPO2) and capnography (ETCO2) readings were taken concurrently. There was no statistically significant relationship between SPO2 and SaO2 with a mean difference between SPO2 and SaO2 of 8.22 per cent. There was a statistically significant relationship between ETCO2 vs PaCO2, but a wide range of ETCO2 values were observed for a given PaCO2. The mean difference between these was 16.16 mm Hg. The study has provided reference intervals for arterial blood gas analysis in rabbits and demonstrated that capnography and pulse oximetry readings should not be relied upon in conscious rabbits as a guide to ventilation and oxygenation.