Search

Thin films of energetic materials enable a diverse range of characterization measurements: structure, surface energy and adhesion, and even reactivity. Here we describe growth of thin films by a physical vapor deposition method (sublimation) using a dedicated instrument which can operate at ultra-high vacuum. The approach enables fabrication of thin films of energetic materials that are otherwise difficult to process by traditional methods, for example because of their low solubility. The intention is to use this instrument as a platform for studying pure materials and co-deposited materials grown either as multi-layers or as co-crystals. Examples of TATB and LLM-105 film morphologies grown using this technique are presented.

Introduction This study investigates the current practice of surgeons in the United Kingdom with regards to their usage of prophylactic antibiotics for percutaneous orthopaedic procedures. Methods An electronic survey of 10 questions was devised and sent to all members of the British Orthopaedic Association. Three hundred and three replies were obtained (172 consultants, 131 trainees). Results Only half the numbers of orthopaedic surgeons would routinely use antibiotics for percutaneous K-wire fixation. Of the other half, 28% would never prescribe antibiotics and 22% would use them in special circumstances only. These ‘special circumstances’ were also not standardised. 92% of those who did prescribe antibiotics would administer single dose only and the majority (90%) would administer them during induction. There was no significant difference between trainees and consultants or between different orthopaedic procedures with regards to whether prophylactic antibiotics were prescribed or not. Discussion This survey highlights the split of opinion amongst practising orthopaedic surgeons as to the necessity or otherwise of antibiotic prophylaxis in percutaneous orthopaedic procedures. There are no reliable guidelines and further work should be carried out to investigate this subject.

The application of speckle metrology to high strain rate materials characterisation, through the use of appropriate high-speed photography, provides an exciting opportunity for measurements to be performed on materials, and in loading configurations, which were not previously possible. In particular, a full understanding of the mechanical properties of inhomogeneous materials such as composites, geological and biological materials at high strain rates, requires more data than has previously been provided by the split Hopkinson pressure bar, which only gives a measure of average specimen response. Following from a separate paper by Siviour and Grantham describing the application of speckle metrology to the Hopkinson bar, this paper discusses recent experiments in which this application was used to make previously unobtainable measurements of specimen response. Results are presented from experiments performed on a polymer bonded explosive simulant and long polymer rods. These experiments were designed to evaluate the technique in a number of different configurations, as well as providing useful experimental data on these materials. In addition, we revisit the use of speckle metrology in the high strain rate Brazilian test.

While some recent neuroimaging studies have implicated medial rostral prefrontal cortex (MPFC) in ‘mentalizing’ and self-reflection, others have implicated this region in attention towards perceptual vs self-generated information. In order to reconcile these seemingly contradictory findings, we used fMRI to investigate MPFC activity related to these two functions in a factorial design. Participants performed two separate tasks, each of which alternated between ‘stimulus-oriented phases’ (SO), where participants attended to task-relevant perceptual information, and ‘stimulus-independent phases’ (SI), where participants performed the same tasks in the absence of such information. In half of the blocks (‘mentalizing condition’), participants were instructed that they were performing these tasks in collaboration with an experimenter; in other blocks (‘non-mentalizing condition’), participants were instructed that the experimenter was not involved. In fact, the tasks were identical in these conditions. Neuroimaging data revealed adjacent but clearly distinct regions of activation within MPFC related to (i) mentalizing vs non-mentalizing conditions (relatively caudal/superior) and (ii) SO vs SI attention (relatively rostral/inferior). These results generalized from one task to the other, suggesting a new axis of functional organization within MPFC.

The dynamic compressive properties of Dyneema have been investigated using a drop-weight machine. The mechanical behaviour was monitored using high-speed photography and aforce transducer. There was considerable variation in behaviour shot-to-shot, but all the specimensof this material were observed to shatter in this apparatus. Stress-time plots showed multiple fail-ures on a timescale of approximately 0.2 ms interval. 1. INTRODUCTIONDyneema is the registered trademark of a self-reinforced polyethylene (manufactured by DSM)which is showing great promise as a replacement for brittle-fibre-reinforced epoxies in variousdynamic applications [1–3]. As part of an investigation of its high rate mechanical properties, wehave measured the impact response of this material in compression using a dropweight [4].2. EXPERIMENTALDropweights are used in many industrial settings as a conceptually simple impact test. Their mainadvantage over other techniques of similar strain rates is their ability to apply a large force for acomparatively long period of time. Their main disadvantage is that their output signal usually haslarge oscillations due to ringing within the dropweight or the associated force transducer [5, 6].In the work reported here, a weight of mass 6.414 kg is dropped from a height of about 1.25 montoaforce transducer (Figure 1).The massis guidedtothe target bytwo rodson either side. Theimpact speed is about 5 m s

Previous research at room temperature and quasi‐static loading rates has shown that above the glass transition conditions of their binders, PBX Brazilian disc specimens fail by the localisation of strain in binder rich areas, followed by debonding of the binder from the largest energetic crystals. Crystal fracture is rare and the process is predominantly intergranular. In contrast we show, for a UK PBX, that when the temperature is reduced to below the glass transition condition of the binder system, failure becomes predominantly transgranular. Such data are required for the development and validation of PBX micromechanical models. This paper outlines the current state of research and details the important observations to date.

Porous and granular materials are widely found in a number of environments. One of the most important groups both geographically and in the construction industry are the sands. A review of the response of sand (42% porous) over a wide range of strain rates is presented. Factors such as water content and density variation are addressed. In addition a very low‐density silica dust (95% porous) is also discussed in relation to its contrasting behaviour.

The thermal conductivity, diffusivity and heat capacity of the UK PBX EDC37 and its binder system have been measured over a temperature range of ambient to approximately 90 °C. Independent measurements of any two of the above, and knowledge of the density, allows the third to be calculated. Comparisons between the directly measured and calculated values give an indication of the reliability of such data. Thermal conductivity measurements were made using the Lee's disc method, thermal diffusivity via Angstrom's method, and heat capacity via Differential Scanning Calorimetry. Such data are required for the development and validation of PBX thermal models. This paper outlines the current state of research and details the important observations to date.

This prospective, controlled study compared cold compressive dressings with wool and crepe in the postoperative management of patients undergoing total knee replacement (TKR). Forty TKR patients were assessed for blood loss, pain, swelling, and range of motion. Patients in the cold compression group had less blood loss through suction drainage (982 ml versus 768 ml). A higher proportion of patients in the treatment group did not require blood transfusion postoperatively. Mean opiate requirements were lower in the cold compression group (0.57 versus 0.71 mg/kg/48 hours). The cold compression device appeared to reduce blood loss and pain following TKR.

Room temperature stress‐strain curves were measured for the polymer bonded explosive (PBX) EDC 37 at strain rates between 400 s−1 and 4000 s−1. The material was found to exhibit strong strain rate dependence in this region, the strength increasing linearly with increasing rate. Speckle photography was used to measure the two dimensional surface deformation of the specimens during the test. The behaviour was found to be uniform at most rates, however, the specimens tested at 4000 s−1 showed shear banding.

OBJECTIVE--To compare the efficacy and safety of terbinafine 1% cream and clotrimazole 1% cream in the treatment of tinea pedis. DESIGN--Multicentre, double blind parallel group study. SETTING--32 general practices and one hospital. PATIENTS--256 patients with mycologically confirmed tinea pedis. Of the 211 patients evaluable, 107 were randomised to terbinafine (75 male, 32 female; mean (range) age 40 (12-81) years) and 104 to clotrimazole (79 male, 25 female; mean (range) age 36 (12-71) years). INTERVENTIONS--Terbinafine 1% cream applied twice daily for one week and inert cream applied twice daily for the next three weeks. Clotrimazole 1% cream applied twice daily for four weeks. MAIN OUTCOME MEASURES--Mycological cure (negative results on microscopy and culture) and effective treatment (mycological cure plus no or minimal signs and symptoms) measured at weeks 1, 2, 3, 4, and 6. RESULTS--At week four rates of mycological cure were 93.5% for terbinafine and 73.1% for clotrimazole (p = 0.0001); and at week six 97.2% for terbinafine and 83.7% for clotrimazole (p = 0.001). Rates of effective treatment at week 4 were 89.7% for terbinafine and 58.7% for clotrimazole (p = 0.0001); and 89.7% for terbinafine and 73.1% for clotrimazole (p = 0.002) at week 6. CONCLUSION--These results indicate that a one week course of terbinafine 1% cream is more effective in the treatment of tinea pedis than a four week course of clotrimazole 1% cream, both in terms of mycological cure and effective treatment.

Equations of state can be used to predict the relationship between pressure, volume and temperature. However, in shock physics, they are usually only constrained by experimental observations of pressure and volume. Direct observation of temperature in a shock is therefore valuable in constraining equations of state. Bloomquist and Sheffield (1980, 1981) and Rosenberg and Partom (1984) have attempted such observations in poly(methyl methacrylate) (PMMA). However, their results disagree strongly above 2GPa shock pressure. Here we present an improved fabrication technique, to examine this outstanding issue. We make use of the fact that the electrical resistivity of most metals is a known function of both pressure and temperature. If the change in resistance of a thin metal thermistor gauge is measured during a shock experiment of known pressure, the temperature can be calculated directly. The time response is limited by the time taken for the gauge to reach thermal equilibrium with the medium in which it is embedded. Gold gauges of thickness up to 200 nm have been produced by thermal evaporation, and fully embedded in PMMA. These reach thermal equilibrium with the host material in under 1 us, allowing temperature measurement within the duration of a plate impact experiment.

Using a recently extended version of the two-dimensional aerial image simulator, SPLAT 1 , we show that annular illumination of a soft-x-ray 1:1 ring-field camera at 13 nm increases image contrast for features with spatial frequencies immediately above the coherent cutoff and that surface figure errors are responsible for the asymmetric, spatially-shifted images that have been observed experimentally.

We evaluated the normal Baumann (humerocapitellar) angle in 114 children aged 2-13 years because the angle has been proposed to be useful in assessing alignment of the elbow in children with supracondylar fractures of the humerus. In this age range, the angle did not change significantly, nor was there any significant difference between the angle in boys and girls. The mean Baumann angle was 72 degrees (SD 4 degrees), and 95% of normal elbows had a Baumann angle of 64 degrees-81 degrees.

Two patients, one with Sézary syndrome and one with mycosis fungoides are described, in whom lesions on the palms and soles were associated with extensive ulceration and gave rise to diagnostic difficulty. Extensive ulceration of the palms and soles is uncommon; its presence should alert clinicians to the possibility of cutaneous T-cell lymphoma.

We report three cases of thoracic spine translocation without neurological deficit. In each case bilateral pedicular fractures, demonstrated by computed tomography, produced 'floating arches' which account for the sparing of the cord. If computed tomography demonstrates adequate canal dimensions, these patients may be treated conservatively, but the treatment of choice at specialist spinal centres is operative stabilisation.

A half-sided, single-blind, comparative study of a new modified formulation of 1% hydrocortisone/10% urea and 0.1% betamethasone valerate cream in the treatment of dry eczema showed that the two products were equally effective at the end of 1, 2 and 3 weeks of treatment in terms of efficacy and speed of action. No statistically significant differences could be detected between either preparation in any of the trial's measures (i.e. overall severity score, dryness/scaling, erythema, papules, itching, excoriation or lichenification) at any of the weekly assessments. The incidence of side-effects was the same with both treatments and patients' preference was equally divided between the two creams.

Pigmented neurofibroma is a rare tumour of the dermis. The clinical features and histology of a lesion occurring in a female of 69 years are described in this report. This entity was first described by Willis in 1959 in three patients with pigmented dermal tumours which showed a plexiform structure and the presence of pseudo-Meissnerian bodies.

We reviewed the cases of 38 children with 45 congenitally dislocated hips who presented for primary treatment after the age of three years. Of these, 34 hips were managed by the 'direct approach' of Somerville and Scott (1957); 14 of these required secondary operations for subluxation, often with a poor outcome. Eleven hips were treated by combined pelvic and femoral osteotomy which, in general, gave good results. At a mean follow-up of 16.7 years, 80% of the whole series had a good or excellent clinical result and 51% were good or excellent radiologically. Simultaneous correction both above and below the hip is considered to be the best treatment for the older child with congenital hip dislocation.

Summary Erythema gyratum repens (EGR) is a rare and distinctive eruption which is widely regarded as a marker of internal malignancy (Rook, Wilkinson & Ebling, 1979). We report two cases of pityriasis rubra pilaris which presented in the classical form, but developed EGR during the resolving stage of the condition. Malignancy was not detected in cither case, despite extensive investigation.

SummaryA double-blind controlled trial was carried out over a period of 3 weeks to assess the effectiveness of 1% hydrocortisone, in a specialized carbamide drug delivery system, compared with 0.1 % betamethasone 17-valerate cream in the treatment of 21 patients with bilateral, symmetrical, non-infective inflammatory dermatoses. The trial preparations were applied topically twice daily, each to one side only during the trial. Although overall patient preference tended to favour betamethasone 17-valerate, the physician's assessment of clinical improvement, based on severity rating scores, indicated that both preparations were equally effective and there were no significant differences between the calculated mean percentage clinical improvements at the end of each week.

A prospective survey has been made of the injuries to members of the public attending a well established ice rink in a major city. Comparison is made with series in the literature reporting high levels of injuries, with corresponding demands on local hospital services, from newly established ice rinks. The main conclusion is that demands on hospital services have been markedly reduced for the well established rink, with corresponding savings in health service resources.

We report a case of pseudarthrosis of the radius successfully treated by free vascularised bone grafting. After a comprehensive review of the literature, we recommend this as the treatment of choice in this condition. We also report the use of callus distraction of an incorporated vascularised bone graft to achieve bone lengthening.

An area of fibrous dysplasia of bone may undergo rapid enlargement which may be due to either cystic degeneration or malignant transformation. These complications may be clinically and radiologically indistinguishable and, unless both are borne in mind, incorrect management may follow. Magnetic resonance imaging was used in one of our cases and was the only imaging modality to demonstrate the true nature of the condition.

SummaryA small uncontrolled pilot study was carried out in 6 patients with ischaemic leg ulceration in which pain was severe to assess the effectiveness of thymoxamine in the relief of pain and on the rate of healing. Patients were treated for 3 days with intravenous injections of 0.1 mg thymoxamine/kg body weight and then with oral 40 mg thymoxamine 4-times daily for a further month. The results showed that there appeared to be a definite improvement in pain during intravenous therapy and this was maintained to a large extent, although not so definite, on oral therapy. No enhanced rate of healing, however, was evident.

Summary.— Three case of unilateral idiopathic hyperhidrosis are described. Two of the lesions were congenital; the thrid occurred in later life. Quantitative sweat collections demonstrated that the sweat glands in the lesion were hyperresponsive to those stimuli, which normally evoked sweating in the skin sites where the lesions occurred. Hyper-responsiveness of the sweat glands to cholinergic stimuli was also demonstrated, and histology revealed greatly enalrged glands. These results suggest that the hyperhidrosis is due to Increased glandular mass, although sweat gland hypersensitivity could notberuled out as an additional contributing factor to the hyperhidrosis. Local anticholinergic therapy was found to besuccessful in the treatment of all 3 patients.

To the Editor.— Further to the observation by Fine and Omura 1 in the July 1985 issue of theArchivesof a patient with herpes gestationis (HG) who had persistent disease 11 years post partum, we would like to draw your attention to a similar case that we first reported in the British Journal of Dermatology . 2 Our patient, aged 25 years, developed a pruritic urticarial eruption at 37 weeks' gestation during her first pregnancy. By two days post partum, the pruritic urticarial eruption had evolved into a widespread bullous eruption. Treatment with high doses of systemic corticosteroids and, subsequently, azathioprine failed to control the disease satisfactorily. The administration of dapsone and sulfapyridine resulted in allergic reactions; therefore, therapy with these drugs had to be discontinued before any assessment could be made of the effect on her disease. When our case was published, we reported that her blistering had persisted