No abstract

Background. Many patients suffer from lack of retention of conventional mandibular overdentures due to loss of clip retention over time. Computer-aided design-computer-aided manufacturing (CAD-CAM) milled polyether ether ketone (PEEK) materials may be used for the construction of retentive housing and clips for improving retention of implant-supported overdentures. Objective. To compare retention and patient satisfaction of implant-supported mandibular overdentures retained by conventional nylon clip and metal housings for ball attachments versus PEEK clip and housings. Methods. Twenty-two participants were divided into 2 equal groups (n = 11). The conventional group received implant-supported mandibular overdentures retained by metal housings and nylon retentive elements, while the PEEK group received implant-supported mandibular overdentures retained by PEEK retentive elements and housings. The PEEK retentive elements were made using computer-aided design and computer-aided manufacturing (CAD-CAM). The evaluation included measuring the retention by applying a gradual pulling up force by force meter and patient satisfaction with a 7-point visual analog scale (VAS) at overdenture insertion and 3, 6, and 12 months subsequently by a research interviewer. Results. The PEEK group showed statistically significantly increased retention force ( P < 0.05 ) at the time of insertion (37.6/17.79) and after 3 months (33.9/16.78), 6 months (32.7/15.97), and 12 months (31.65/13.05). The conventional group had a statistically significantly higher mean overall satisfaction ( P < 0.05 ) at the time of insertion (65/82.18). No statistically significant difference was found after 3 months (87.81/84.72). The PEEK group showed statistically significantly higher mean overall satisfaction ( P < 0.05 ) after 6 months (86.36/80.18) and 12 months (85.45/79.54). Conclusions. According to the results of this study, the PEEK retentive material provided more retention than did the conventional material and led to improved patient satisfaction. The study was registered at clinical trials.gov (https://clinicaltrials.gov/ct2/show/NCT05079048).

PURPOSE: The aim of this study was to evaluate biting force of patients with unilateral mandibular distal extension area treated with two different designs of the removable partial denture (RPD), conventional RPD, and new design of extracoronal castable precision attachment (OT Unilateral attachment). MATERIALS AND METHODS: This study was conducted on 16 patients with unilateral mandibular distal extension area with the second premolar is the last abutment teeth. The patients were divided into two equal groups, Group I received conventional RPD, which provides cross arch stabilization and a double Aker clasp was fabricated. Group II received new design of extracoronal castable precision attachment (OT Unilateral attachment). Evaluation of biting force by loadstar sensor, patients of both groups were evaluated at the time of prosthesis insertion, 3, 6, and 1 year later. Statistical analysis performing one-way analysis of variance followed by Tukey’s post hoc test to compare between all follow-up periods within each group, comparison between two groups regarding each follow-up period was performed by independent t-test. RESULTS: Both treatments yielded better after-treatment summary when compared with the baseline; however, better results were obtained and showed a statistically significant increase in Group II (OT unilateral design), especially after 3, 6 months, and 1 year later. CONCLUSION: From the results of this study, it was concluded that: It is preferable to use the new design of extracoronal castable precision attachment (OT unilateral) being simpler, more comfortable to the patients and give high masticatory efficiency in the form of biting force than conventional RPD.

Dieulafoy's lesion (DL) is a rare but important cause of obscure gastrointestinal bleeding that may be overlooked during diagnostic endoscopy. Mortality rates are similar to those of other causes for gastrointestinal bleeding. Diagnosis by upper endoscopy is the modality of choice during acute bleeding. In the absence of active bleeding, the lesion resembles a raised nipple or visible vessel. There are no guidelines regarding effective selective therapy for DL, when diagnosed, endoscopist experience is the major determinant of the treatment strategy. Following our strategy, an expert endoscopist with a skilled assistant should have a high rate of successful DL diagnosis when an obscured gastrointestinal lesion is suspected. Cyanoacryltes compounds have been used successfully in management of Gastric varices and DLs. To our knowledge, there have been no previous reports regarding use of isoamyl-2-cyanoacrylate (AMCRYLATE(®); Concord Drugs Ltd., Hyderabad, India) as an effective therapy for gastric DL without serious complications. In our case study, Isoamyl-2-cyanoacrylate (AMCRYLATE(®)) was effective and safe for treating DL. Surgical wedge resection of the lesion should be considered as a therapeutic option if endoscopic therapy fails.

The main objective of this study was to perform model experimentation for predicting draft and power requirements of simple tillage tools such as chisel plow. Four tool operating parameters were chosen to be cases for model experimentation. These were tool rake angle (ranged from 15 to75), tool depth (ranged from 100 to 300 mm), tool speed (ranged from 0.89 to 1.92 m/s), and tool width (ranged from 100 to 400 mm). Experimentation process was carried out using simulation model modified by Afify et al. (2020) based on Sohne's model, (1956).Validation results of such model showed an acceptable agreement between the test data and the model. The model experimentation was conducted by running a program modified by VB Software using real data as inputs of soil parameters from Afify (1999) and Roza (1997). The soil under these studies was clay soil in terms of soil mechanical analysis. Results of model experimentation showed the model could be predicting daft and power requirements by an accuracy exceeds than 90% for the four examined parameters under this study.

Movement of the soil particles during tillage operation is the result of the application of force by the tillage tools. The soil crushed due to the action of the applied force, and soil particles move in various directions. The extent of unnecessary soil movement by tillage tools during tillage practices will affect the rate of soil erosion. Moreover, there is a lack of experimental data concerning soil movement with currently used tillage tools and particularly the effect of repeated tillage over decades of time (Sharifat and Kushwaha, 1997). Under this study, a factorial experiment (2x3x3x3) with random design was used. The tool operating parameters were share shape, plowing speed and constant level of share depth. On the other hand, the soil parameters were soil moisture content and soil compaction. Soil movement was determined using the tracer method introduced by Turkelboom et al. (1996). Results of statistical analysis showed that there are highly significant differences were obtained for the soil movements in three directions with all factors and with the interaction between factors at P 0.01. It could be concluded that the use of shovel share instead of sweep share for the same job will reduce soil movement and consequently reduce the rate of soil erosion.

Energy Energy consumption in buildings is approximately 40% of the total world annual consumption. In hot climate, crucial percentage of energy consumed due to the cooling loads in buildings. Wherefore, tendency towards decreasing the energy demand rises through the revival of passive strategies and encouraging the development of innovative initiatives in different fields. Double skin facade (DSF) is a promising passive strategy to enhance the thermal comfort while decreasing energy consumption. The DSF promotes the convective strategy in the cavity as an additive force to enhance air movement the occupied spaces. The study will introduce a proposed skin inspired from parametric pattern movement and exploit the features of the pattern mutation. The movement of the parametric pattern demonstrates changes in the cavity configuration revealed at the outer skin through the entire height of the façade. The proposed facade generates a special species of fluctuation for air distribution covering larger area of the occupied space by applying the principle of Venturi's effect. The results show enhancement in the magnitude and distribution air velocity inside the occupied space, which assists in improving thermal comfort range inside by natural means.

Background: Welding is the most common way of permanently joining metal parts. Welders use many types of welding equipment set up in a variety of positions. Arc welding is the most common type. Welding, soldering, and brazing workers often are exposed to a number of hazards, including the intense light created by the arc, poisonous fumes, and very hot materials.Objective: The aim of the present study was to investigate some of the health hazards among gas metal arc welders with special emphasis on renal and lung examination and to monitor the level of chromium in blood and urine, and studying its relation with the renal condition. Our aim was also to detect early renal affection by measuring of B 2 microglobulin in urine. Subjects and methodology: This study was conducted in three welding shops in El Manial, and El Maadi, in Cairo. The study was accomplished during the months of October and November, 2006.The studied group comprised 18 workers in the metal arc welding shops. They were adult men aged between 18-42 years (26.5 ±7.8), working on the basis of 12 hours/day with one day off per week. None of the workers used any protective equipment during working hours. A referent group of 20 males matched for age that ranged from 21-41 yrs., (26.2±6.38), sex, socioeconomic status, smoking Health education programs of workers about hazards of exposure to harmful agents and proper measures for protection is essential and this includes training programs to raise awareness among welders. Effective local exhaust ventilation to remove hazardous gases and fumes is essential. Finally, urinary or blood chromium can be used as indicators of recent chromium exposure among welders.