Large area multi-filamentary plasma source for large volume plasma device-upgrade.

This paper discusses the salient features and plasma performance of the newly installed Large Area Multi-Filamentary Plasma Source (LAMPS) in large volume plasma device-upgrade. The plasma source is designed to exhibit a plasma electron density of ∼1018 m-3, low electron temperature (∼eV), and a uniform plasma cross section of 2.54 m2. The directly heated LAMPS emits accelerated primary energetic electrons when it is biased with a negative discharge voltage with respect to the anode. The hairpin shaped tungsten (W) filaments, each of diameter 0.5 mm and length 180 mm, are heated to a temperature of 2700 K by feeding ∼19.5A to each filament. The LAMPS consists of 162 numbers of filaments, and it has been successfully operated with a total investment of 50 kW of electrical power. The LAMPS as a laboratory plasma source is characterized by large operational life, ease of handling, better compatibility to high pressure conditions, and advantages over other contemporary plasma sources, viz., oxide coated cathodes, RF based sources, and helicon sources, when producing plasma over large cross sections and fill volumes. Pulsed argon plasma is produced with quiescence (δnene≪1%) using LAMPS for the duration of 50 ms and a reasonably good radial uniformity (Ln = 210 cm) is achieved. Good axial uniformity is also observed over the entire length of the device. Initial measurements on plasma parameters have yielded plasma density of ∼2×1017m-3 with existing set of filaments. A plasma density of ∼1018 m-3 is envisaged for larger thickness of filaments, such as 0.75 and 1.0 mm, with the existing plasma source assembly setup.

Micro/nano-machines for spilled-oil cleanup and recovery: A review.

High-efficiency, safe and economically viable nano-engineered platforms for oil spill cleanup and recovery are of great importance. This review takes account of the concept of nanomotors and micromotors and their most advancements in use for oil spill treatment. The fundamental facets of artificial micro- and nano-machines/nanobots/nanomotors (MNMs) are first documented, followed by the most recent influencing developments in chemical engineering approaches toward their specific utilizations. The surface chemistry of these MNMs, their behaviors in different water matrices and their roles in the removal of oil are examined, revealing great rooms for improvement. The strategies for surface and structural modification of these tiny machines toward enhancing their reactivity in the removal of oil and coupled tasking are discussed in details, highlighting the significance of fit-for-duty design and tailored fabrication. The engineering limitations and practical implementation barriers of this emerging technology and how it can be overcome are also considered. Finally, some engineering boundaries and perspectives of this fast-evolving field are proposed at the end.

Unilateral Branchial Sinus with Unilateral Renal Agenesis: A Variant of BOR Syndrome? A Case Report.

Patient presented with a congenital discharging branchial sinus. Pre-operative work up including a CT scan of the abdomen-pelvis revealed absence of the left kidney. Branchio-Oto-Renal (BOR) syndrome, a rare autosomal dominant disorder is characterized by branchial arch anomalies, otological and renal anomalies. Clinical manifestations tend to have considerable variability, But no case with branchial and renal abnormality sans otological defects has been described yet in the spectrum of BOR syndrome variants.

Profile of children with poor school performance in Mumbai.

We report on the etiology of poor school performance (PSP) in children assessed at a learning disability clinic in western India over 12 months. Specific learning disabilities (dyslexia, dysgraphia and dyscalculia) were the commonest cause of PSP (72.76%), followed by borderline intellectual functioning (8.94%), language barrier (8.54%), and mental retardation (4.88%).

A study of warning letters issued to clinical investigators and institutional review boards by the United States Food and Drug Administration.

BACKGROUND: Warning letters (WLs) issued by the US FDA (United States Food and Drug Administration) mention the nature of violations by clinical investigators and institutional review boards (IRBS) and can help as training tools. METHODS: WLs issued by the US FDA between January 2005 and December 2010 to clinical investigators and IRBs were reviewed for various violation themes. RESULTS: A total of 129 WLs were issued to investigators and 40 to IRBs. Among the WLs issued to investigators, 67 (51.95%) were issued for drug-related research and 62 (48.06%) were for device-related research. For investigators, deviation from the investigational plan was the most common violation (81%) followed by failure to maintain accurate and adequate case histories (58.1%) and then informed consent issues (48.06%). Among WLs issued to IRBs, failure to have and follow standard operating procedures (SOPs) was seen in 93.89% followed by issues pertaining to membership (59.4%). When compared to a similar study published in 2004, for clinical investigators, no improvement was seen with respect to deviation from the investigational plan and study supervision. However, a significant improvement was seen in reporting of adverse events to IRBs, and some improvement was seen in the area of informed consent. For IRBs, no improvement was seen in most areas which included maintaining and following SOPs, membership, quorum requirements, misuse of expedited review and informed consent. CONCLUSION: WLs serve as indicators of an active regulatory agency which should translate into greater safety for participants in clinical trials. For developing countries with weak regulatory systems, these can serve as useful learning tools to help improve systems and put in patient safeguards.

Comparative bioavailability study of clonazepam after oral administration of two tablet formulations.

OBJECTIVE: To assess the bioavailability of clonazepam from two brands of 2 mg tablet formulations--Epitril and reference brand. METHODS: A two-way randomised cross-over bioavailability study was carried out in 12 healthy male volunteers. Coded plasma samples were analysed for levels of clonazepam by high performance liquid chromatography (HPLC) method. RESULTS: The mean Cmax, Tmax t1/2 beta and AUC (0-48) for Epitril were: 16.31 +/- 3.07 ng/mL, 1.63 +/- 0.48 h, 46.97 +/- 12.26 h and 207.70 +/- 57.07 ng/ml.h; for reference brand were 19.75 +/- 5.95 ng/mL, 1.42 +/- 0.29 h, 46.88 +/- 11.29 h and 215.70 +/- 50.89 ng/ml.h respectively. These were comparable and the differences were not statistically significant. CONCLUSION: Based on above pharmacokinetic parameters, Epitril was bioequivalent to reference brand.

Cytoskeletal pathology in familial cerebral amyloid angiopathy (British type) with non-neuritic amyloid plaque formation.

The histological features of familial cerebral amyloid angiopathy (British type) with non-neuritic amyloid plaque formation (FAB) include deposition of amyloid, (supposedly associated with the C-terminal fragments of both alpha- and beta-tubulin), in small cerebral and spinal arteries, hippocampal amyloid plaques and neurofibrillary tangles (NFTs) as well as ischaemic white matter changes. In the present study we report on the cytoskeletal pathology that occurs in association with FAB. Sections from the hippocampus and cerebellum of three cases from three unrelated families were stained with silver impregnation methods and antibodies to antigens including tau, neurofilaments, ubiquitin and glial fibrillary acidic protein. Electron microscopic examination of the hippocampus was carried out in one case. All hippocampal subregions contained large numbers of NFTs and neuropil threads (NT), which were stained with both phosphorylation-dependent and phosphorylation-independent tau antibodies and ultrastructurally were found to be composed of paired helical filaments (PHFs). Although the majority of the amyloid plaques were of the non-neuritic type, distended PHF-containing and tau-positive neurites were seen in close proximity of a minority of the hippocampal plaques. The perivascular amyloid deposits of the cerebellum contained numerous ubiquitin-positive granular elements similar to those seen in cerebellar A beta amyloid plaques in Alzheimer's disease. In FAB severe cytoskeletal pathology is present in areas most affected by amyloid plaque deposits, thus suggesting a localised neurotoxic effect of the poorly characterised amyloidogenic peptide characteristic of this condition.

Alterations in hippocampal non-phosphorylated MAP2 protein expression in schizophrenia.

Microtubule-associated proteins (MAPs) are central to the development of normal neuronal cytoarchitecture and have been suggested in previous studies to be altered in schizophrenia. We investigated hippocampal phosphorylated and non-phosphorylated MAP2 expression in schizophrenia in relation to neuronal orientation and interneuronal distance. One paraffin embedded mid-hippocampal block was obtained from each of 8 schizophrenic and 11 control postmortem brains and immunohistochemistry for the phosphorylated and non-phosphorylated forms of MAP2 performed. Within the corona ammonis (CA) subregions and the subiculum, we assessed densitometry readings for non-phosphorylated MAP2-positive neurones (MAP2-NP), and counted the number of neurones immunopositive for phosphorylated MAP2 (MAP2-P). Using image analysis computer software we measured interneuronal distances and neuronal orientation. While there were no overall alterations in densitometric density of MAP2-NP neurones in any hippocampal subregions, we found a left-sided increase in densitometric density of MAP2-NP neurones within the subiculum (F = 8.740, P < 0.021), and the CA1 (F = 7.044, P < 0.033) of schizophrenic subjects which were unrelated to age, postmortem interval or neuroleptic exposure. There was no accompanying alteration of interneuronal distances, neuronal orientation. The findings support previous work demonstrating altered subicular MAP2 expression in schizophrenia and indicate that the finding may be lateralised. However, in contrast to previous investigations, we have demonstrated this alteration in MAP2 expression is due to an increase in the non-phosphorylated form of MAP2, rather than a decrease in total MAP2 expression. These findings suggest that cytoskeletal assembly is abnormal in schizophrenia and generate testable hypotheses regarding the developmental basis of the disorder.

Medullary cell carcinoma of the thyroid: metastases to the central nervous system.

We document a case of a patient who had been treated for a medullary cell carcinoma of the thyroid three years previously and who presented with a three month history of ataxia, weakness and headache. A CT scan showed contrast enhancing lesions in the posterior fossa. An MIBG uptake scan showed that there was some uptake in the cerebellar lesions; however, it was not sufficient to rely on this alone for treatment. The larger of these lesions was therefore surgically resected. Immunocytochemistry, using CAM 5.2, CEA and chromogranin, demonstrated a positive reaction which strongly favoured a diagnosis of metastases from a medullary cell carcinoma of the thyroid. However, absolute confirmation of the diagnosis was obtained using immunocytochemistry with calcitonin. Medullary cell carcinomas of the thyroid usually spread locally and metastasis to the brain has never before been reported.

Perils of a 'true' posterior communicating artery aneurysm.

Successful 'clipping' of the apparent neck of a posterior communicating artery aneurysm was carried out, but 2 days later the patient had a further haemorrhage and died. Postmortem examination revealed that the aneurysm was that of a rare fusiform 'true' posterior communicating artery aneurysm.

Delayed cerebral ischaemia: the pathological substrate.

Ischaemic complications both at the level of the cortex and the hypothalamus are well recognised after an aneurysmal subarachnoid haemorrhage. We have studied histological changes in the cortex (53 patients) and hypothalamus (48 patients) in patients who died after an aneurysmal subarachnoid haemorrhage. Cortical ischaemic lesions were demonstrated in 41 of the 53 patients studied. These changes were more common in patients who had impaired control of systemic blood pressure (p = 0.0004) and in patients who died gradually (p = 0.0003). Hypothalamic lesions were found in 24 of 48 patients studied; 23 of these patients had widespread associated changes in the cerebral cortex. Patients with moderate/severe cortical changes tended to have hypothalamic lesions and it was uncommon for patients with no cortical lesions to have changes in the hypothalamus (p = 0.0007). We believe that these histological changes are due to diffuse microangiopathy which develops slowly after a subarachnoid haemorrhage and affects the cortex and hypothalamus. Because the cortical lesions are widespread we postulate that they may be implicated in the aetiology of the well described psychosocial or cognitive problems in patients who survive a subarachnoid haemorrhage.

Malignant glioma in laboratory workers.

In 1989 an increased risk of cancer, with a higher than expected incidence of brain tumours, was reported in laboratory workers at the Pasteur Institute, Paris. Three cases of primary brain tumours occurring in three laboratory workers from one laboratory in a district general hospital also came to light. Although this may have been due to coincidence or geographic clustering, the need for stringent safety standards in all laboratories is reiterated, and it is proposed that a national register should be established to record the causes of death in laboratory workers.

Radiation therapy for primary squamous cell carcinoma of the vagina: Stanford University experience.

A retrospective analysis of 38 patients with primary squamous cell carcinoma of the vagina seen at Stanford University Medical Center from 1958 to 1984 was undertaken. Patients were analyzed with regard to symptoms, stage, treatment techniques, survival, patterns of failure, and complications. Eighteen patients were classified as FIGO Stage I, 5 as Stage II, 10 as Stage III, and 5 as Stage IV. The 5-year disease-free survival was 94% in Stage I, 80% in Stage II, 50% in Stage III, and 0% in Stage IV. Five patients (13%) had eight major complications secondary to treatment. Only 2 of 23 patients with Stage I or Stage II disease developed a recurrence. There was a significant correlation between dose and response in patients treated with radiotherapy.

Primary intracranial choriocarcinoma.

Two cases of primary intracranial choriocarcinoma are reported. One patient died with raised intracranial pressure and pulmonary metastases whereas the second patient, who was diagnosed early, has remained well a year after chemotherapy. Human chorionic gonadotrophin level estimation in serum and cerebrospinal fluid is a useful marker in suspected cases, and chemotherapy following biopsy appears to be the treatment of choice.