Evaluation of the paraskeletal clamp system (Mennen plate) in treatment of mandibular fractures

In this study, we used the relatively recent Paraskeletal clamp system (Mennen plate) to evaluate its effectiveness in the treatment of mandibular fractures. This study was conducted on eight patients with mandibular fractures selected from the out patient clinic, Oral Surgery Department, Faculty of Oral and Dental Medicine, Cairo University. Patient sample consisted of six males and two females, four patients were children below the age of 11 years, while the other four were edentulous above the age of 58. Each patient was thoroughly examined both clinically and radiographically. Data collected from each patient were recorded in a special examination chart. Under general anesthesia, the fracture was exposed using a submandibular approach. The fractured segments were reduced and fixed using micro-5 Mennen plates. All patients were followed up both clinically and radiographically for six months postoperatively. Results obtained from this study showed uneventful healing of all patients with no cases of non-union, bony infection or osteomyelitis as proven both clinically and radiographically. All the patients presented normal functioning occlusion and facial symmetry. No bony step deformities were detected.     

Comparing the Effectiveness of Coatings on Carbide andCermet Cutting Tool Inserts

A series of metal cutting experiments was performed on a CNC lathe to evaluate the performance of various coatings on different tool substrates. The workpiece material was plain medium carbon steel and the cutting tool materials were carbide and cermet inserts coated with various single as well as multilayer coatings. Machining was done under various cutting conditions of speed and feed-rate, and for various durations of Cutting. The output parameters studied were the cutting forces (axial, radial and tangential), the surface roughness of the workpiece, as well as the tool wear (crater and flank wear). From these results, the performances of the various cutting inserts are evaluated and compared. Results show that cutting forces are significantly lower when using coated cermets than when using coated carbides although different coatings on the same substrate also result in different cutting forces. However, there is less difference in the surface roughness of the finished workpiece for the various coatings and substrates.     

Long-term results of short segmental syngeneic small intestinal transplantation: comparison of jejunal and ileal grafts

A short-segment intestinal graft is favorable to reduce the rate of rejection and the incidence of graft-versus-host disease in recipients of small intestine transplantation. To determine whether a jejunal or an ileal graft is preferable with respect to intestinal morphology and function, syngeneic two-step small intestinal transplantations were performed using male Lewis rats (RT1(1)). They were divided into two groups according to the small intestine donor site (group 1 received 10 cm of jejunum; group 2 received 10 cm of ileum). There was no significant difference in the survival rate or weight gain between the two groups. Nearly all the hematologic findings, serum nutritional parameters, and results of liver function tests were normal for both groups. The only difference was that the serum total bile acid level was significantly higher in group 2. Fifty weeks after transplantation, the graft mucosa showed normal architecture, with adaptive hyperplasia of villi and crypt noted through histological study. The villus height of group 1 was 595 +/- 64 microns (control, 452 +/- 67 microns); that of group 2 was 732 +/- 53 microns (control, 217 +/- 20 microns). The crypt depth of group 1 was 228 +/- 35 microns (control, 165 +/- 24 microns); that of group 2 was 320 +/- 19 microns (control, 102 +/- 19 microns). These compensatory changes were more pronounced in group 2. The authors conclude that, on the basis of long-term functional capacity, there was no significant difference between jejunal and ileal grafts, and that both segments were suitable for transplantation. However, the ileal graft was considered to be better with respect to morphological adaptation.     

Separation of bacterial capsular and lipopolysaccharides by preparative electrophoresis

Preparative gel electrophoresis was used to separate and purify extracellular, capsular and lipopolysaccharides (EPSs, CPSs, and LPSs, respectively) from crude bacterial extracts. The procedure effectively separates CPS from LPSs. In addition discreet size ranges of these various polysaccharides can be isolated. The 'rough' (R-type), 'smooth' (S-type), and 'semi-smooth' LPSs were separated from one another. In addition different size classes of 'semi-smooth', or S-type LPS, can be separated. This procedure was demonstrated for diverse bacterial species, including the soil bacteria Rhizobium fredii, and the enteric bacterial species, Salmonella enteritidis and Proteus mirabilis. In the latter case, it was also possible to separate capsular polysaccharide from its lipid-bound form.     

Implementing the Put Prevention into Practice program

Put Prevention into Practice (PPIP) is a national program designed to improve the delivery of preventive care to patients by all primary care clinicians. It covers the full range of clinical preventive services, including immunizations, screening tests, chemoprophylaxis, and counseling interventions. The materials that comprise this program involve patients, office/clinic systems and staff, and clinicians, including nurse practitioners. The need for preventive care, the barriers to be overcome, the PPIP program, and a strategy for its implementation are delineated. Principles for successful implementation include: high level administrative support, ownership by all the players in the implementation process, a person designated to manage implementation, and an ongoing evaluation/auditing process that provides feedback to clinicians and others participating in the program.     

Electric-field induced fluctuations in laser generated plasma plume

The effect of an external electric field on laser-generated plasma has been studied. It is observed that the laser-generated plasma can be used for the ignition of a spark in the presence of a low voltage external electric field. An eight-fold emission intensity enhancement in Cu Ⅰ spectral lines are measured as compared to the signal intensity in the absence of an external electric field.The plasma parameters remain the same initially, up to a few microseconds after the generation of plasma, and this feature makes it more interesting for the quantitative analysis of any sample using laser induced breakdown spectroscopy(LIBS). In the presence of an external electric field,fluctuations(contraction and expansion) in the laser-generated plasma are observed which increase the plasma decay time and consequently result in enhanced signal intensity.     

A survey on trust based detection and isolation of malicious nodes in ad-hoc and sensor networks

Mobile ad-hoc networks (MANETs) and wireless sensor networks (WSNs) have gained remarkable appreciation and technological development over the last few years. Despite ease of deployment, tremendous applications and significant advantages, security has always been a challenging issue due to the nature of environments in which nodes operate. Nodes’ physical capture, malicious or selfish behavior cannot be detected by traditional security schemes. Trust and reputation based approaches have gained global recognition in providing additional means of security for decision making in sensor and ad-hoc networks. This paper provides an extensive literature review of trust and reputation based models both in sensor and ad-hoc networks. Based on the mechanism of trust establishment, we categorize the stateof-the-art into two groups namely node-centric trust models and system-centric trust models. Based on trust evidence, initialization, computation, propagation and weight assignments, we evaluate the efficacy of the existing schemes. Finally, we conclude our discussion with identification of some unresolved issues in pursuit of trust and reputation management.     

Study on orthogonal turning of titanium alloys with different coolant supply strategies

In this paper, the effects of different coolant supply strategies (using flood coolant, dry cutting, and minimum quantity of lubricant [MQL]) on cutting performance in continuous and interrupted turning process of Ti6Al4V are investigated. Based on the observation of the cutting forces with the different coolant supply strategies, the mean friction coefficient in the sliding region at the tool–chip interface has been obtained and used in a finite element method (FEM) to simulate the deformation process of Ti6Al4V during turning. From the FEM simulation and Oxley’s predictive machining theory, cutting forces have been estimated under different coolant supply strategies and verified experimentally.