The measurement of attogram mass accumulation on nanostructures during e-beam scanning, using carbon nanopillars in resonant mode.

We present a 'universal' phenomenon of mass accumulation and its sensing on nanostructures due to electron beam cracking of residual gas molecules during electron beam scanning. Though the extent of this phenomenon is limited to a very small increment in mass or thickness, it has significant implications for both the scientific and technological aspects of almost all processes in the nanodomain. Mass accumulation in every frame scan (or per second) is of the order of a few attograms and the thickness of deposition is of the order of picometre (fraction of a monolayer) only. Direct measurement of a mass or thickness of this order is difficult. Nanopillars having a high resonance 'Q-factor' have been successfully exploited for such high precision measurements. The mass accumulation rate has been characterized with respect to (i) electron energy and beam current, (ii) environment within the chamber (presence or absence of a precursor gas) and (iii) partial exposure of the nanopillars to the e-beam.

Co-occurrence of superparamagnetism and anomalous hall effect in highly reduced cobalt-doped rutile TiO2-delta films.

We report a detailed magnetic and structural analysis of highly reduced Co doped rutile TiO(2-delta) films displaying an anomalous Hall effect (AHE). The temperature and field dependence of magnetization, and transmission electron microscopy, clearly establish the presence of nanosized superparamagnetic cobalt clusters of approximately 8-10 nm size in the films at the interface. The co-occurrence of superparamagnetism and AHE raises questions regarding the use of the AHE as a test of the intrinsic nature of ferromagnetism in diluted magnetic semiconductors.

Evidence for a quantum phase transition in Pr2-xCe(x)CuO4-delta from transport measurements.

The doping and temperature dependences of the Hall coefficient, R(H), and ab-plane resistivity in the normal state down to 350 mK is reported for oriented films of the electron-doped high-T(c) superconductor Pr(2-x)Ce(x)CuO(4-delta). The doping dependences of beta (rho=rho(0)+ATbeta) and R(H) (at 350 mK) suggest a quantum phase transition at a critical doping near x=0.165.

High temperature ferromagnetism with a giant magnetic moment in transparent co-doped SnO(2-delta).

The occurrence of room temperature ferromagnetism is demonstrated in pulsed laser deposited thin films of Sn(1-x)Co(x)O(2-delta) (x<0.3). Interestingly, films of Sn(0.95)Co(0.05)O(2-delta) grown on R-plane sapphire not only exhibit ferromagnetism with a Curie temperature close to 650 K, but also a giant magnetic moment of 7.5+/-0.5 micro(B)/Co, not yet reported in any diluted magnetic semiconductor system. The films are semiconducting and optically highly transparent.

Plantar ulceration in patients with leprosy.

A controlled trial was implemented to investigate the hypothesis that plantar ulcer sites associated with leprosy, in subjects who were supplied with foot orthoses, would heal more quickly than those in a control group. The population was comprised of individuals with impairments associated with leprosy, living near a leprosy hospital in India. Ulcer area was compared in the two groups and assessed at three-monthly intervals from July 1993 to March 1994. At the March 1994 assessment 58% of ulcers in the experimental group had healed but only 14% in the control group. At this point patients in the control group were supplied with orthoses and three months later, in June 1994, 60% of the ulcers in the experimental group and 62% of ulcers in the control group had healed. The results of this study demonstrate that orthotic intervention can significantly reduce the duration of ulceration.

Wax therapy for dry feet in leprosy.

A comparative study of the effect of wax therapy and foot soaks on dry plantar skin was conducted in patients with leprosy. Thirty patients with varying grades of fissures and callosities were given wax therapy for feet, and 20 similar patients were given foot soaks. Patients given wax therapy felt subjectively much better than those who had soaking. Healing of cracks and fissures and softening of callosities was observed more frequently in patients with wax therapy. These differences are statistically significant. As an institutional method wax therapy has definite advantages for treating patients with fissures and callosities, whereas soaking of the feet is easy and readily available in patients' homes to restore the dry skin to normal.

The efficacy of podiatric orthoses as an adjunct to the treatment of plantar ulceration in leprosy.

This study examines the outcome of a management approach to plantar ulceration secondary to leprotic neuropathy. Locally-available resources were used to produce podiatric orthoses which were supplied to an experimental group. The effects on healing time and quality of healing were compared with a control group. Both groups were ambulant (the programme sought not to interfere with socioeconomic independence). Using standard nonparametric methods of analysis, it was demonstrated that the effects on healing rate, attributed to the experimental intervention, were highly significant. Over a 7-month period, 57% of the experimental group ulcers healed, while only 12.5% of the control group ulcers healed. The experimental intervention also demonstrated a positive effect on the quality of ulcer healing. This effect was not reflected in the control group.

Vibration sense and tarsal disintegration.

The extent of loss of vibration and pressure sensations was assessed in 21 leprosy patients with disintegration of the tarsus. Feet which had and did not have tarsal disintegration both showed severe impairment of pressure sensation, but the loss of vibration sense was more severe in feet which had undergone the destructive process. It appears that loss of deep sensation is an important factor in the process of tarsal disintegration in feet which are already anaesthetic. Measurement of vibration sense using a biosthesiometer may be a valuable clinical test in the investigation and follow-up of the patient with the insensitive foot to identify those at risk of developing tarsal disintegration.

Newer designs in foot-wear for leprosy patients.

Micro-cellular rubber (MCR) foot-wear has been used widely over the past several years for the anaesthetic feet of leprosy. Although MCR has got good shock absorbing and moulding qualities, many tend to reject the foot-wear because of the stigma of the disease which it carries. Two newer models of foot-wear which would meet the demands of anaesthetic sole and avoid the stigma because of their resemblance to foot-wear available in the market were tried. Model mark II fulfilled the needs and was acceptable to the patients. Such models must be tried and acceptable and effective foot-wear need to be made available.

Management of tarsal disintegration (T.D.) in leprosy.

Tarsal Disintegration (T.D.) is a known entity occurring exclusively in neuropathic foot of Leprosy and being influenced by several factors among which the disease itself and altered biomechanics constitute the main. In this study done on more than fifty cases at the Dr. Bandorawalla Leprosy Hospital, Kondhawa these factors have been studied in detail and it has been found that the increased and abnormal shearing forces constitute one of the major factors both in occurrence and progression of T.D. Treatment based mainly on the conservative lines is thus aimed at minimizing these forces which occur during the heel-toe pattern gait. Depending upon the severity of the case immobilization, periodic check x-rays, graded weight bearing and suitable modified footwear appliance is recommended. A Fixed Ankle Brace (FAB) serves well controlling the ankle movements by its rocker action and ultimately reducing the forces occurring during the normal heel-toe pattern. It has also been found that if the case is detected early and treated promptly the process can be controlled satisfactorily. Careful screening in high risk group is stressed and health education emphasized.

A new approach in muscle training to rehabilitate the hand in leprosy.

Rehabilitation of the hand in Leprosy with its deformities and anaesthesia no doubt poses a formidable challenge as far as rehabilitation is concerned. Here we have applied a combination of latest concepts in sports physiology and the exercise followed by the students of ancient Indian martial art known as Krishni Vidya. This exercise consists of crumpling a newspaper sheet with a single hand without any external support. We are unable to explain the type of exercise done by the people before existence of newspaper. They might be using naturally occurring materials for the same like woodbark. With this exercise we have been able to improve the function of the hand remarkably well and the rehabilitation time following surgery is drastically reduced, with function returning close to normalcy. The full function is achieved within four weeks from the date of removal of plaster as compared to eight to ten weeks or more with conventional physical therapy. This full function is not only in mobility but also in co-ordination, static and dynamic strength, speed of movement and flexibility required of a normal hand. 16 patients operated for lumbrical replacement (using sublimis as a motor from the long finger) at the Dr. Bandorawalla Leprosy Hospital were put under the paper crumpling exercise. It was observed that the average time for the achievement of fully close fist was two weeks. (All of them had thumb function intact, i.e. either normal or operated-out of sixteen, four patients were operated for opponens prior to lumbrical replacement).

Observations of tarsal disintegration in the cases operated for foot-drop.

Fifty cases operated for foot-drop during the years 1971-82 were called for follow-up. Out of fifty, twenty cases were reported to the hospital. Three cases among the twenty were found to have changes of tarsal disintegration. The changes were found more confined to the talo-navicular junction. X-ray changes both in non-weight and weight bearing were studied. Their line drawings (tracings from actual radiograph) are presented. It is concluded that due attention should be given to the pre-operative evaluation, operative procedure used and post-operative management particularly the weight-bearing and proper footwear.

Special features of physical therapy in the claw hand of leprosy.

This article emphasizes the vital role of a physical therapist in the surgical programme of the correction of clawing caused in leprosy due to paralysis of intrinsics. Right from the assessment of patient till the final re-education a physical therapist is a must helping in motivating the patient, planning the type of procedure to be performed on him and training the patient post-operatively. If treated early a physical therapist himself can overcome the deformity by the help of various physical therapy measures without surgical intervention.

Splinting of the hand in leprosy.

Clawing of the hand in Leprosy, which is caused due to paralysis of intrinsics can often be prevented and corrected to some extent if looked in properly. Splints can contribute a lot to this. This article emphasizes the use of variety of splints prepared from alumafoam, hexcelplast and such other materials, as an adjunct to other physiotherapy measures like wax-bath, massage and exercises.

Tarsal disintegration (T.D.) in leprosy.

Tarsal Disintegration in leprosy has been a challenge as far as its prevention is concerned. It is, no doubt, a complex and less understood phenomenon influenced by many factors. In this study made at Dr. Bandorawalla Leprosy Hospital, Kondhawa, factors like insensitivity, loss of protective reflex, infection, lepromatous infiltration of bones etc. have been taken into consideration, but, more emphasis is laid on the biomechanical factors (i.e. altered muscle pulls due to muscular paralysis resulting in imbalance) and the resulting change in weight bearing areas and weight transmission lines. Sixteen cases of neuropathic feet were examined clinically and radiologically. All were burnt out cases of tuberculoid and borderline tuberculoid variety excepting one which was active being of lepromatous variety. Tracings made from actual radiographs of the patients were studied. It was found that apart from insensitivity, biomechanical factors play a lot of importance in accentuating the process of T.D. The changes are predominantly seen in Tuberculoid variety of Leprosy. Attempts have been made to understand this process more closely by drawing conclusions based on the kinetic and kinematic analysis of the normal human foot and comparing it with neuropathic feet.

Observations on peg-prosthesis in leprosy.

Three leprosy patients with peg-prosthesis were studied in detail. It was found that there were several disadvantages of this type of prosthesis. However, its application in a rural situation has some merits, and with some suggested modifications, it could be adopted with better results.