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Tribological components cost just a fraction of the whole spacecraft, but they often lead to failures that partially or completely disrupt the spacecraft. Mechanical components used in space applications have to withstand extreme and severe environmental conditions such as very high or very low cryogenic temperatures, high vacuum, corrosive elements and radiation. MoS2 is the most widely used lubricating material in space applications. It possesses a lamellar structure with strong covalent bonds within layers and simultaneously weak van der Wall’s interlayer bonds, resulting in easy shearing of the crystals in the direction parallel to the basal planes, hence acting as a good solid lubricant. In this research, a thin film nano scale coating of MoS2 was deposited on steel using Physical Vapour Deposition (PVD). The PVD technique used was the RF magnetron sputtering process. Material characterization was performed using X-Ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Raman spectroscopy. According to the results, the developed MoS2 nano coatings have a polycrystalline structure with basal planes that are oriented perpendicular to the substrate surface.

The lubrication effect of solid-based materials has been recognized for centuries, but their use as lubricants dates back to only about 50 years. Solid lubricants are used in applications where parts operate under severe operating conditions such as extreme temperatures and very high vacuum. Solid lubricants replace liquid based lubricants for operation under extreme environmental conditions that are beyond the capability of a liquid-based lubricant such as high or very high vacuum, high and cryogenic temperatures, radiation, corrosive gases, and fretting wear. Applications such as space mechanisms, satellites, space vehicles, turbopumps, nuclear reactors, refrigeration plants, etc are examples of such operating conditions. In this research, nano scale composite coatings of MoS2with varied proportions of ZrN (5%, 10% and 20%) were deposited on Ti3SiC2 Max phase substrate using Physical Vapour Deposition (PVD). The PVD technique used was the RF magnetron sputtering process. Material characterization was carried out using Field Emission Scanning Electron Microscope (FESEM) Spectroscopy and Energy Dispersive X-Ray Spectroscopy (EDS). Addition of ZrNis observed to reduce the porosity of the self-lubricating MoS2 coating.

We report a case of squamous cell carcinoma of external auditory canal in an Omani man with oculocutaneous albinism. The disease mimicked inflammatory process revealing positive cultures for various microorganisms during the course of his illness. He was eventually biopsied to rule out atypical infective process or presence of malignancy. He was staged as T4N0M0 and treated with radical doses of palliative radiation therapy which was very well tolerated and resulted in a complete resolution of disease clinically and a major soft tissue response on radiological imaging. Another unique finding was the absence of epidermal growth factor receptor (EGFR) protein overexpression in the tumour specimen. More than 90% of mucosal squamous cell carcinoma (SCC) involving the head and neck region overexpress the EGFR protein in normal skin patients. SCC is the predominant cutaneous malignancy in albinos, and the presence of EGFR protein overexpression in cutaneous SCC is believed to be 56-58% in normal skin patients. The scientific literature is scarce on reporting incidence of EGFR overexpression in either cutaneous or mucosal SCC in albinos, and it remains to be defined whether being albino is the cause for its absence., (2014 BMJ Publishing Group Ltd.)

The bulk alignment of actin filament sliding movement, powered by randomly oriented myosin molecules, has been observed and studied using an in vitro motility assay. The well established, actin filament gliding assay is a minimal experimental system for studying actomyosin motility. Here, we show that when the assay is performed at densities of actin filaments approaching those found in living cells, filament gliding takes up a preferred orientation. The oriented patterns of movement that we have observed extend over a length scale of 10-100 microm, similar to the size of a mammalian cell. We studied the process of filament alignment and found that it depends critically upon filament length and density. We developed a simple quantitative measure of filament sliding orientation and this enabled us to follow the time course of alignment and the formation and disappearance of oriented domains. Domains of oriented filaments formed spontaneously and were separated by distinct boundaries. The pattern of the domain structures changed on the time scale of several seconds and the collision of neighboring domains led to emergence of new patterns. Our results indicate that actin filament crowding may play an important role in structuring the leading edge of migrating cells. Filament alignment due to near-neighbor mechanical interactions can propagate over a length scale of several microns; much greater than the size of individual filaments and analogous to a log drive. Self-alignment of actin filaments may make an important contribution to cell polarity and provide a mechanism by which cell migration direction responds to chemical cues.

We report a 2 1/2 years old female child who presented with Malignant Sacrococcygeal Yolk sac (Endodermal Sinus) tumor as presacral mass with ulceration of overlying skin. Her ultrasonography (USG)abdomen revealed a huge presecral mass with irregular margins extending in to the pelvis, pushing the rectum antero-laterally. CT scanning of abdomen confirmed USG finding with out enlargement of retroperitoneal lymph nodes and no involvement of the liver. Serum AFP was abnormally elevated. The tumor was excised along with Coccyx in-toto through posterior approach dividing the sacrum and 3-Drugs (VAC) Chemotherapy started postoperatively i.e. 2-weeks after surgery. Here we discuss our experience with this extremely rare malignant extra-gonadal germ-cell tumor and review of literature.

In a randomised controlled prospective trial, different antibiotic regimens were evaluated as prophylaxis in wound infection following elective surgical procedures. Four hundred and four consecutive cases were divided in four groups. Two groups were allotted two different conventional postoperative antibiotic regimens while the fourth group received short term perioperative antibiotic; group one served as control. A higher frequency of postoperative wound infection was observed in the controls. Results showed reduction in gross infection in only group III where short term perioperative antibiotic was used. Combination of penicillin and streptomycin were not found effective, and low infection rate was observed with Cephamendole used perioperatively.