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Ulcerating skin lesions are manifestations of human ISG15 deficiency, a type I interferonopathy. However, chronic inflammation may not be their exclusive cause. We describe two siblings with recurrent skin ulcers that healed with scar formation upon corticosteroid treatment. Both had a homozygous nonsense mutation in the ISG15 gene, leading to unstable ISG15 protein lacking the functional domain. We characterized [ISG15.sup.-/-] dermal fibroblasts, HaCaT keratinocytes, and human induced pluripotent stem cell-derived vascular endothelial cells. ISG15-deficient cells exhibited the expected hyperinflammatory phenotype, but also dysregulated expression of molecules critical for connective tissue and epidermis integrity, including reduced collagens and adhesion molecules, but increased matrix metalloproteinases. [ISG15.sup.-/-] fibroblasts exhibited elevated ROS levels and reduced ROS scavenger expression. As opposed to hyperinflammation, defective collagen and integrin synthesis was not rescued by conjugation-deficient ISG15. Cell migration was retarded in [ISG15.sup.-/-] fibroblasts and HaCaT keratinocytes, but normalized under ruxolitinib treatment. Desmosome density was reduced in an [ISG15.sup.-/-] 3D epidermis model. Additionally, there were loose architecture and reduced collagen and desmoglein expression, which could be reversed by treatment with ruxolitinib/doxycycline/TGF-[beta]1. These results reveal critical roles of ISG15 in maintaining cell migration and epidermis and connective tissue homeostasis, whereby the latter likely requires its conjugation to yet unidentified targets., Introduction Monogenic type I interferonopathies are a heterogeneous group of autoinflammatory and autoimmune disorders characterized by persistently elevated levels of type I interferons (IFN-I) (1-3). The underlying molecular mechanisms are [...]

In Egypt, highly pathogenic avian influenza A(H5N1) clade 2.2.1 virus was introduced to poultry via migratory birds in late 2005 (1) and is now endemic among poultry in Egypt (2). [...]

This paper provides an expert review of the tribological considerations that dictate the sliding wear performance of thermal spray WC-Co coatings. Structure--property relationships and failure modes are discussed to grasp [...]

Manufacturing process routes of materials can be adapted to manipulate their microstructure and hence their tribological performance. As industrial demands push the applications of tribological materials to harsher environments of higher stress, starved lubrication, and improved life performance, manufacturing processes can be tailored to optimize their use in particular engineering applications. The aim of this paper was there lore to comprehend the structure-property relationships of a wear resistant cobalt-based alloy (Stellite 6) produced from two different processing routes of powder consolidated hot isostatic pressing (HIPing) and casting. This alloy had a nominal wt % composition of Co--28Cr--4.5W--1C, which is commonly used in wear related applications in harsh tribological environments. However; the coarse carbide structure of the cast alloy results in higher brittleness and lower toughness. Hence this research was conducted to comprehend if carbide refinement, caused by changing the processing route to HIPing, could improve the tribomechanical performance of this alloy. Microstructural and tribomechanical evaluations, which involved hardness, impact toughness, abrasive wear, sliding wear, and contact fatigue performance tests, indicated that despite the similar abrasive and sliding wear resistance of both alloys, the HIPed alloy exhibited an improved contact fatigue and impact toughness performance in comparison to the cast counterpart. This difference in behavior is discussed in terms of the structure-property relationships. Results of this research indicated that the HIPing process could provide additional impact and fatigue resistance to this alloy without compromising the hardness and the abrasive/sliding wear resistance, which makes the HIPed alloy suitable for relatively higher stress applications. Results are also compared with a previously reported investigation of the Stellite 20 alloy, which had a much higher carbide content in comparison to the Stellite 6 alloy, caused by the variation in the content of alloying elements. These results indicated that the fatigue resistance did not follow the expected trend of the improvement in impact toughness. In terms of the design process, the combination of hardness, toughness, and carbide content show a complex interdependency, where a 40% reduction in the average hardness and 60% reduction in carbide content had a more dominating effect on the contact fatigue resistance when compared with an order of magnitude improvement in the impact toughness of the HIPed Stellite 6 alloy. Keywords: Stellite 6, HIPing, contact fatigue, abrasive wear, sliding wear

This paper aims to compare the tribo-mechanical properties and structure-property relationships of a wear resistant cobalt-based alloy produced via two different manufacturing routes, namely sand casting and powder consolidation by hot isostatic pressing (HIPing). The alloy had a nominal wt % composition of Co-33Cr-17.5W-2.5C, which is similar to the composition of commercially available Stellite 20 alloy. The high tungsten and carbon contents provide resistance to severe abrasive and sliding wear. However, the coarse carbide structure of the cast alloy also gives rise to brittleness. Hence this research was conducted to comprehend if the carbide refinement and corresponding changes in the microstructure, caused by changing the processing route to HIPing, could provide additional merits in the tribo-mechanical performance of this alloy. The HIPed alloy possessed a much finer microstructure than the cast alloy. Both alloys had similar hardness, but the impact resistance of the HIPed alloy was an order of magnitude higher than the cast counterpart. Despite similar abrasive and sliding wear resistance of both alloys, their main wear mechanisms were different due to their different carbide morphologies. Brittle fracture of the carbides and ploughing of the matrix were the main wear mechanisms for the cast alloy, whereas ploughing and carbide pullout were the dominant wear mechanisms for the HIPed alloy. The HIPed alloy showed significant improvement in contact fatigue performance, indicating its superior impact and fatigue resistance without compromising the hardness and sliding/abrasive wear resistance, which makes it suitable for relatively higher stress applications. [DOI: 10.1115/1.2736450] Keywords: Stellite 20, HIPing, abrasive wear, sliding wear, fatigue

The impact and fatigue resistance of overlay coatings is significantly influenced by the residual strain (or stress) field induced during coating deposition, post-treatment, and in-service loading. Optimization of the residual strain field is therefore critical to the life and performance of components. Nondestructive measurement of these strain fields in relatively thin (300-400 [micro]m) thermal spray coatings, however, poses a challenge because conventional techniques, such as deep hole drilling, x-ray diffraction, synchrotron diffraction, and changes in beam curvature either make these techniques destructive and/or provides only a very near-surface strain measurement. This particularly complicates the strain analysis in cermet coatings, e.g., WC-Co deposited by the thermal spraying process, where the low penetration depth of x-ray and synchrotron-diffraction ray can only provide a through thickness measurement of stress or strain profile via the destructive layer removal technique. Recent investigations have therefore concentrated on the use of neutron diffraction technique for such analysis, and this paper reports some of the early findings of the comparison of through thickness strain measurements in relatively thin (400 [micro]m) as-sprayed and post-treated WC-12wt. %Co coatings via the neutron diffraction technique. Since neutrons are not charged, they do not interact with the electron cloud surrounding the atom (unlike x-ray); hence, diffraction results from the interaction with the atomic nucleus. Neutrons therefore have greater penetration depth in most engineering materials, and therefore provide a nondestructive through thickness strain measurement. Results of strain measurement are discussed with the structure property relationships and contact fatigue performance, and indicate that post-treatment of these coatings results in harmonization of the strain field within the coating, and at the coating substrate interface. This significantly influences the contact fatigue performance by improving both the cohesive and adhesive strength of these coatings. Keywords: neutron diffraction, residual stress, thermal spray coatings, rolling contact fatigue

Rapid, size-based, deposition of particles from liquid suspension is demonstrated using the nonuniform electric field created by coplanar microelectrode strips patterned on an insulating substrate. The scheme uses the dielectrophoretic force both to distribute aqueous liquid containing particles and to separate the particles.

Byline: P. Mandhan (1), N. Hasan (1), R. Ahmed (1), T. Zuberi (1), S. Mirza (1) Keywords: Key words Neonatal cholelithiasis; Portal-vein thrombosis; Biliary cirrhosis; Cholecystectomy Abstract: Cholelithiasis in infants and children is unusual and is reputedly associated with underlying hemolytic disorders, total parenteral nutrition, ileal disease, and congenital anomalies of the biliary tree. We report a case of cholecystitis with pigmented stones in a 3-month-old infant associated with portal vein thrombosis (PVT) and biliary cirrhosis without the above-mentioned causes. Recanalization of the PV and partial resolution of the cirrhosis was observed following cholecystectomy. To our knowledge, cholelithiasis associated with PVT and cirrhosis in an infant has not been reported in the literature. Author Affiliation: (1) Orthopedic and Medical Institute, Karachi, Pakistan, PK Article note: Accepted: 25 September 1998

Progress is the result of creative ideas and innovative activities. Successful organizations rely on their creative employees to develop new products and services that provide them with a competitive edge in the marketplace. Many large organizations, however, do not demonstrate the leadership necessary to foster creativity by providing a conducive environment and by personally stimulating their creative employees. To address this problem, creativity professionals are characterized, an organizational culture that stimulates creativity is outlined, and blocks to creativity - and ways to overcome them - are discussed. Creativity is combining old ideas or generating new ideas to satisfy a need. Creativity forms something from nothing; innovation shapes that something into products and services. Managing for creativity is to provide the environment, recognition, rewards, and leadership necessary to motivate employees to be creative. Creative professionals have distinctive characteristics; managers should be able to recognize these individuals when filling vacant positions. An organizational culture conducive to the development and testing of creative ideas is essential for stimulating creativity. Creative professionals value recognition and increased self-esteem more than monetary reward.

H.M. Mitchell [1] M. Wiseman [1] R. Ally [2] R. Ahmed [2] I. Segal [2] [4/10] [*] The Cytokine Response to H. pylori is significantly Different in Symptomatic Sowetans compared [...]

This paper presents an experimental investigation of the mechanisms of pit elimination in strip drawing and rolling of stainless steel strips. Strip drawing tests with artificial indents confirm the role of micro-plasto-hydrodynamic lubrication (MPHL) in allowing pits to be reduced in size and depth. The similarity of results for two oils, which differ in viscosity by a factor of 10, is attributed to the fact that oil is drawn out of the pits rather easily, so that the behavior tends to the unlubricated case. Similar behavior is observed for strip drawing of shot blast white hot band. For much smoother bright anneal strip, it is suggested that the presence of an oil film in the unpitted region prevents generation of pressure differences between the pits and the unpitted regions. A comparison of stripdrawn and cold-rolled stainless steel samples show that the change in pit area and [R.sub.q] roughness varies with overall reduction in a remarkably similar way. The reason for such similar behavior is attributed to the absence of hydrodynamic action in preventing pit elimination, albeit for opposite reasons. The similar rate of pit evolution in both cases confirms the usefulness of the strip drawing rig as a tool to model the change of surface topography during rolling, as long as care is taken in matching the regimes of lubrication. [DOI: 10.1115/1.1327580] Keywords: Asperity, Metal Rolling, Strip Drawing, Friction, Lubrication, Surface Finish, Pit, Void, Stainless Steel

Objective: To evaluate students' performance on test questions developed for assessing the students' ability to integrate knowledge. Materials and methods: Questions requiring one best response to a descriptive scenario and testing the ability to integrate knowledge across disciplines were administered as a mock examination to students in the third and fifth (final) year at the end of certifying exams. Students' performance and internal consistency of the tests were determined. Scores obtained in the mock examinations were correlated against mean scores in certifying examinations and in different subjects. Results: The responses of 60 (88%) of the third-year students and 54 (91%) of the final year students were complete and included in the study. The difficulty index of the integrated questions ranged from 26% to 75% and was higher than that of the certifying examinations. None of the integrated questions showed negative discrimination. Scores of the final year students in the mock test showed a weak correlation (r = 0.33, P = 0.01) with the certifying examination scores. The correlation was weaker for third-year students (r = 0.23, P = 0.37). For final year scores, the paired t-test for correlated means was significant (P = 0.19) as was also the correlation of integrated scores against individual disciplines (one-way ANOVA F = 6.377; P = 0.01). The internal consistency of the test was 0.69 for the final year, whereas it was 0.45 for certifying exams. Conclusions: Students found integrated questions difficult. The improved integrating ability of final year students may have resulted from exposure to patients. As evaluation drives learning, appropriate tests of integration should be used in the assessment of students.

To assess students' laboratory skills and abilities to integrate these with knowledge of basic and clinical sciences, a tool was designed at the Aga Khan University in 1997. This paper discusses the development, administration, and refinement of this tool. The model of the Objective-Structured Clinical Examination (OSCE) with multiple timed stations was adopted. Each station objectively tested a standard procedural skill and asked restricted response (with predetermined key) essay questions related to the interpretation of results obtained and application of the underlying concept to arrive at a conclusion. Two separate voluntary practice mock examination sessions were arranged at an interval of 12 weeks. Of the total 72 students of the third year, 61 participated in the first exam and 55 in the second. Those 47 students who took both examinations were included in this correlational study. The scores of OSIPE were correlated with the scores obtained in the total and viva component of the certifying examination and OSCE held at the end of the third year. The internal consistency (reliability) of the two examinations was determined. The mean scores of OSIPE 1, OSIPE 11, combined OSIPE I and 11, certifying examination, and OSCE were 58 [+ or -] 19.8, 48.5 [+ or -] 15.7, 52.7 [+ or -] 14.1, 69.5 [+ or -] 8.7, and 67.0 [+ or -] 9.1, respectively. The internal consistency for the first OSIPE was 0.47; for the second examination it increased to 0.85. The internal reliability for the two OSIPEs combined was 0.71. Scores of OSIPE II and combined scores of OSIPE I and II showed a correlation of 0.413 and 0.445 (P = 0.004 and 0.002) with the scores of OSCE. However, a weak and nonsignificant correlation was found with the scores obtained in the certifying (comprehensive) and viva-voce examination. Verbal and written comments from the students illustrated that although they liked the form of the test, it was difficult. They also felt that there was a discrepancy between the overall instructional strategies and this test. Results indicate that there is a need to explore and refine this tool further before it can be considered for implementation in university examinations. The attributes that are being actually tested by this instrument should also be ascertained.

This cross-sectional survey investigated the undergraduate medical students' familiarity with computers at the Aga Khan University. This study aimed to determine the need for support strategies to ensure that all medical graduates are capable of using computers for learning, professional practice, communication, and research. The study evaluated computer competencies of the class of 1997 and 1998 at graduation and for the class of 2003, one month from entry to the Medical College. For the latter, the questionnaire was modified to elicit similar information. The availability of computers in the Learning Resource Centre (LRC) from 1995 to 1998 was noted. For the classes of 1997, 1998, and 2003, 62.96%, 93.67%, and 24.3% students were using computers for word processing; 27.78%, 65.82%, and 23.7% for preparation of presentations; 5.56%, 39.24%, and 18.8% for literature search; and 40%, 44%, and 61% for E-mail, respectively. The number of students capable of using the computers has increased in the ensuing years. The study depicted that students are using computers more frequently for word processing, data analysis, presentations, and E-mail than for searching for additional information. The increased use of computers by the class of 2003 (new entrants) may be the result of a combination of home~-acquired computer skills, availability of more computers in the LRC, and an increase in the number of instructional strategies requiring discovery of information.

Acoustic Emission (AE) measurements can be used to supplement the mechanical information available from an indentation test. The extent to which AE data can be used to replace time-consuming surface […]

The micro-plasto-hydrodynamic lubrication (MPHL) model of pit evolution is extended to account for the variation of sliding speed and strain rate in rolling and drawing processes. Results show that all of the following factors are important: pit angle, lubricant viscosity and pressure viscosity coefficient, material yield stress and sliding speed. Theoretical predictions for the change in pit area during the deformation process are well correlated by a non-dimensional group of these parameters. The model agrees reasonably with the measured change in pit volume and area from drawing experiments on cold rolled stainless steel strip containing both artificial and stochastic roughness.