570 research outputs found

    3D Woven Composites: From Weaving to Manufacturing

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    Manufacturing near-net shape preforms of fibre-reinforced composites has received growing interest from industry. Traditionally, a preform was made from 2D fabrics, but recently, it has been shown that 3D textiles can be used with success; with weaving being the predominant technology for carbon fibre composites. In 3D weaving, weft, warp and binder fibres run across, along and through the fabrics in the X, Y and Z directions, respectively. Producing a unitised single-piece fabric and subsequently reducing the takt time required for rapid composite manufacturing are two of the main advantages of using 3D woven preforms. Weaving of 3D fabrics, manufacturing of 3D composites, physical characterisation and mechanical testing of infused composites samples are discussed in this chapter. Finally, a large automotive composite made of single-piece 3D woven preform was manufactured and presented for demonstration

    Towards Standardized, Safe and Efficacious Screening Approaches to Patients with Lower Extremity Peripheral Arterial Disease in the setting of Lower Extremity Arthroplasty

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    INTRODUCTION: Peripheral arterial disease (PAD) impedes recovery from lower extremity arthroplasties (LEA) and increases risk of complications/mortality, yet there aren’t standards for screening PAD patients pre-LEA. This review proposes some. METHODS: This review searched databases for articles containing relevant terms. Non-English articles, those unrelated to LEA, and duplicates were excluded. Articles were cross-referenced to find other relevant papers for a total of 111. RESULTS: Up to 49.2% of PAD patients have CAD. Wagner grade III/IV ulcers increase amputations and decrease wound closures. The Wound, Ischemia, and Foot Infection (WIfI) system provides more accurate, and therefore actionable, assessment. Overlooking PAD in surgery patients is linked to sequelae from tourniquets. Arterial calcification increases risk of perioperative blood loss from vascular compression, anemia, and critical limb ischemia. Compounding risk factors for PAD (diabetes, smoking, etc.) increase likelihood of future PAD diagnosis. If SBP\u3e180 or DBP\u3e110 mmHg, forgo elective surgery. Non-cardiac surgery patients with hypertension should receive a beta-blocker one day pre-surgery and perioperatively. Smoking cessation four weeks preoperatively and abstinence four weeks postoperatively may halve wound complications. Absent/asymmetrical pulses should prompt vascular referral pre-LEA. ABI may be falsely normal in asymptomatics with moderate aortoiliac stenosis. Risk of hematoma formation and LEA infection suggests waiting one year while continuing antiplatelet therapy. DISCUSSION/CONCLUSIONS: Adequate blood flow is imperative peri- and postoperatively for optimal healing from LEA. Before orthopedic surgery, we suggest meticulous history and assessment to identify PAD risk factors and determine tolerance for surgical intervention. Patients should be stratified for amputation risk and revascularization benefit using the WIfI system. ABI should be performed to assess severity of vascular stenosis. Patients \u3c0.9 should receive vascular consultation, then reassessment. These recommendations could help clinicians assign vascular intervention pre-LEA, minimize complications/reoperations, truncate spending, and improve patient satisfaction/well-being

    The recent advances in the nanotechnology and its applications in food processing : a review.

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    The objectives of this paper was to discuss the latest development of nanotechnology, especially in food industries, to give clearer picture about the effect of nanotechnology in food industries and to highlight the latest applications of nanotechnology in food processing industry. However, the risk issues involving the use of nanotechnology in food were also explored. The outcome of this research revealed that the nanotechnology could be useful for controlling and manipulating the matter at the nanoscale level during processing. On the other hand, nanotechnology could also help the consumers to modify the food depending on their own nutritional needs and tastes. However, from health viewpoint, the potential risks of nanoscale materials and the possibility of the accumulation and translocation of nanoparticles in the body should be avoided

    Patients with Chronic Kidney Disease and Their Quality of Life

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    This study aimed at exploring the assessment of Quality of Life (QOL) in patients with Chronic Kidney Disease (CKD), and aiming at assessing the QOL of patients with stages 1–5 Chronic Kidney Disease CKD on conservative treatment in order to identify a possible association between Quality Of Life QOL and progression of kidney insufficiency. The results were compared with those obtained for patients on hemodialysis. Sociodemographic, clinical and laboratory data were also evaluated. And the study concluded that research efforts have expanded significantly to determine the state of pediatric CKD patient HRQOL and the factors that impact HRQOL across all stages of CKD and all modalities of renal replacement therapy. Data from all studies suggest that children with a renal transplant fare better with respect to HRQOL than those receiving dialysis.

    Seismic response analysis of linked twin tall buildings with structural coupling

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    Effect of structural links on seismic responses for a linked building system has been investigated in this paper by using finite element modeling technique. The linked building system in this study is represented by twin 40-story reinforced concrete frame-wall structures horizontally coupled by structural links. It is assumed that the two adjacent buildings were similar in this linked building system, so the two adjacent stories could be linked at the same height by an inter-building link. The linked building system is modeled as a rigid floor diaphragm for towers and as a beam for each link fixedly linked to the perimeter structural framework of the buildings. By employing earthquake time history excitation, the seismic responses of the twin towers were computed at different locations for the link. The responses of structures were evaluated and compared. The analysis outcomes indicated that the link could effectively change the structural responses of the linked building system. The structural responses have been decreased in some cases compared to the single tower, referring to the extra link stiffness as gathering the single tower to withstand seismic excitation. While the responses have been increased in other cases, attributing to the additional mass of link. Thus, in the design of seismic-resistant linked building systems, care must be taken. Particularly regarding properties of the link, specifically mass, stiffness, and location, as well as the link resistance with respect to the strength of the link and/or the structural elements composing the link to obviate undesired structural responses

    Physiological responses of callus from gerbera jamesonii Bolus ex. Hook f. to Gamma Irradiation

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    In the present study, in vitro mutagenesis techniques were applied to investigate the effects of gamma irradiation at 0, 10, 20, 30, 40, 50 and 60 Gy on physiological changes in callus of Gerbera jamesonii Bolus ex. Hook f. Biochemical changes in chlorophyll and soluble protein content of pre- and post- irradiated Gerbera callus were studied. Non-irradiated callus demonstrated the highest amount of chlorophyll content as compared to callus irradiated at 10, 20, 30, 40, 50 and 60 Gy. In addition, the amount of chlorophyll b was relatively higher than chlorophyll a in both the irradiated and non-irradiated callus, except for callus irradiated at 10 Gy. Biochemical differentiation based on total soluble protein content revealed gradual reduction after day 9 of exposure to gamma irradiation. Reduction of soluble protein content was observed in all the treatments as the increase of incubation period

    Association between vitamin D receptor gene polymorphisms and chronic periodontitis among Libyans

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    Background: Chronic periodontitis (CP) is a common oral disease characterized by inflammation in the supporting tissue of the teeth ‘the periodontium’, periodontal attachment loss, and alveolar bone loss. The disease has a microbial etiology; however, recent findings suggest that the genetic factors, such as vitamin D receptor (VDR) gene polymorphisms, have also been included.Aim: Investigation of the relationship between VDR gene polymorphisms and CP among Libyans.Materials and methods: In this study, we examined 196 unrelated Libyans between the ages of 25 and 65 years, including 99 patients and 97 controls. An oral examination based on Ramfjord Index was performed at different dental clinics in Tripoli and information were collected using a self-reported questionnaire. DNA was extracted from buccal swabs; the VDR ApaI, BsmI, and FokI polymorphisms were genotyped using polymerase chain reaction and were sequenced using Sanger Method.Results: A significant difference in the newly detected ApaI SNP C/T rs#731236 was found (p0.022), whereas no significant differences were found in ApaI SNP G/T rs#7975232, BsmI SNPA/G rs#1544410, and FokI SNP A/G rs#2228570 between patients and controls (p0.939, 0.466, 0.239), respectively.Conclusion: VDR ApaI SNP C/T rs#731236 may be related to the risk of CP in the Libyan population.Keywords: chronic periodontitis; vitamin D receptor; gene; polymorphisms; variations; SN

    10 years of experience in adopting, implementing and evaluating progress testing for Saudi medical students

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    Objectives: The progress test (PT) is a comprehensive examination that is designed to match the knowledge acquisition necessary at graduation and monitors progress during the entire period of an undergraduate program. Qassim College of Medicine (QCM) began using the multi-institutional PT in the Kingdom of Saudi Arabia (KSA). This study aimed to determine if the PT can be utilized to assess the progress of medical students at different Saudi medical colleges with different educational approaches, as well as whether this testing modality could be accepted by other colleges. Methods: Beside the establishment of a PT committee, comprehensive blueprinting was crafted to sample 200 A-type multiple choice questions (MCQs) from different disciplines. The PT is a paper-and-pencil model and is answered in a 4-h period. All PT items followed a uniform design. Results: In total, 13 rounds of the progress test have been conducted. The number of participating colleges increased from three (with 285 students) in the first test (May 2012) to more than 20 (with &gt;6000 students) in the ninth round (February 2017). The average % scores for first-year students ranged from 3.0% to 7.9% while the average scores for fifth-year students ranged from 34.0% to 43.0%. Conclusion: The conduction of this meticulously crafted test to evaluate knowledge achievement at medical graduation is a fruitful tool and helps to provide constructive feedback for test-takers and other stakeholders relating to their relative positions among other fellows at the national level.</p

    Safety and efficacy of implantable phakic contact lens versus implantable collamer lens in myopia correction

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    Background: Phakic intraocular lenses (pIOLs) have proven to be excellent substitutes for excimer laser keratorefractive surgery in certain situations. We aimed to assess the efficacy and safety of two pIOLs, the implantable collamer lens (ICL V4c) versus the implantable phakic contact lens (IPCL V2), for myopic correction. Methods: In this prospective randomized clinical trial, we allocated eligible eyes with myopia &gt; - 6 diopters into IPCL or ICL implantation groups, each including 100 eyes of 100 individuals. Preoperative and postoperative assessments at 3, 6, and 12 months included measurements of the spherical equivalent (SE), uncorrected distance visual acuity (UCDVA), best-corrected distance visual acuity (BCDVA), intraocular pressure (IOP), maximum keratometry (K1), minimum keratometry (K2), mean keratometry (Kmean), anterior chamber depth (ACD), anterior chamber angle (ACA), and endothelial cell density (ECD). Results: The groups had comparable demographic characteristics and baseline visual and anatomical values (all P &gt; 0.05). The UCDVA, BCDVA, and SE of the two groups were comparable at baseline and at all postoperative follow-up examinations (all P &gt; 0.05). Both groups experienced significant improvements in UCDVA, BCDVA, and SE at three months postoperatively (all P = 0.001), and measurements remained stable for up to 12 months. Keratometry readings were comparable between the groups over the follow-up period and remained unchanged at all visits (all P &gt; 0.05). The ACA in the ICL group was significantly decreased at three months postoperatively (P = 0.001) and then widened significantly at 6 and 12 months (both P = 0.001). In the IPCL group, the postoperative ACA was significantly decreased at three months (P = 0.001) and was comparable to that in the ICL group (P &gt; 0.01). However, at the 6- and 12-month postoperative visits, the ACA was significantly narrower in the IPCL group than in the ICL group (both P = 0.001). The ACD in both groups was decreased at three months postoperatively (both P = 0.001) and remained stable until the end of the study. The ECD remained comparable between the groups at all postoperative visits (all P &gt; 0.05). We did not observe a significant ECD reduction in either group at any postoperative follow-up visit (all P &gt; 0.05). We encountered no serious complications in either group. Conclusions: ICL and IPCL had comparable safety and efficacy outcomes in terms of anterior chamber morphometrics, visual and refractive results, and corneal parameters. Further multicenter randomized clinical trials with longer follow-up periods, larger sample sizes, and measurement of additional anterior chamber and corneal morphometrics, vault, and other vision parameters are needed to verify these findings

    Divorce and Severity of Coronary Artery Disease: A Multicenter Study

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    The association between marital status and coronary artery disease (CAD) is supported by numerous epidemiological studies. While divorce may have an adverse effect on cardiac outcomes, the relationship between divorce and severe CAD is unclear. We conducted a multicenter, observational study of consecutive patients undergoing coronary angiography during the period between April 1, 2013, and March 30, 2014. Of 1,068 patients, 124 (12%) were divorced. Divorce was more frequent among women (27%) compared to men (6%). Most divorced patients had been divorced only once (49%), but a subset had been divorced 2 (38%) or ≥3 (12%) times. After adjusting for baseline differences, there was no significant association between divorce and severe CAD in men. In women, there was a significant adjusted association between divorce and severe MVD (OR 2.31 [1.16, 4.59]) or LMD (OR 5.91 [2.19, 15.99]). The modification of the association between divorce and severe CAD by gender was statistically significant for severe LMD (Pinteraction 0.0008) and marginally significant for CAD (Pinteraction 0.05). Among women, there was a significant adjusted association between number of divorces and severe CAD (OR 2.4 [95% CI 1.2, 4.5]), MVD (OR 2.0 [95% CI 1.4, 3.0]), and LMD (OR 3.4 [95% CI 1.9, 5.9]). In conclusion, divorce, particularly multiple divorces, is associated with severe CAD, MVD, and LMD in women but not in men
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