On the Morphological Deviation in Additive Manufacturing of Porous Ti6Al4V Scaffold: A Design Consideration

Additively manufactured Ti scaffolds have been used for bone replacement and orthopaedic applications. In these applications, both morphological and mechanical properties are important for their in vivo performance. Additively manufactured Ti6Al4V triply periodic minimal surface (TPMS) scaffolds with diamond and gyroid structures are known to have high stiffness and high osseointegration properties, respectively. However, morphological deviations between the as-designed and as-built types of these scaffolds have not been studied before. In this study, the morphological and mechanical properties of diamond and gyroid scaffolds at macro and microscales were examined. The results demonstrated that the mean printed strut thickness was greater than the designed target value. For diamond scaffolds, the deviation increased from 7.5 μm (2.5% excess) for vertical struts to 105.4 μm (35.1% excess) for horizontal struts. For the gyroid design, the corresponding deviations were larger, ranging from 12.6 μm (4.2% excess) to 198.6 μm (66.2% excess). The mean printed pore size was less than the designed target value. For diamonds, the deviation of the mean pore size from the designed value increased from 33.1 μm (−3.0% excess) for vertical struts to 92.8 μm (−8.4% excess) for horizontal struts. The corresponding deviation for gyroids was larger, ranging from 23.8 μm (−3.0% excess) to 168.7 μm (−21.1% excess). Compressive Young’s modulus of the bulk sample, gyroid and diamond scaffolds was calculated to be 35.8 GPa, 6.81 GPa and 7.59 GPa, respectively, via the global compression method. The corresponding yield strength of the samples was measured to be 1012, 108 and 134 MPa. Average microhardness and Young’s modulus from α and β phases of Ti6Al4V from scaffold struts were calculated to be 4.1 GPa and 131 GPa, respectively. The extracted morphology and mechanical properties in this study could help understand the deviation between the as-design and as-built matrices, which could help develop a design compensation strategy before the fabrication of the scaffolds.     

Fabrication of a graphene-based sensor to detect the humidity and the temperature of a metal body with imprecise data analysis

Graphene is a 2D material with remarkable properties. The present study demonstrates the fabrication of a graphene-based sensor for measuring the temperature and humidity of a metal body. The graphene sensor was fabricated by depositing a thin film of graphene nanoparticles between silver electrodes (separated by ∼50 μm) on a glass substrate. The graphene thin film was characterized by XRD, Raman spectroscopy and UV-vis techniques. The capacitance and resistance for both the relative humidity (in the range of 0–100% RH) and temperature (in the range of 230–310 K) were measured using an LCR meter at 1 kHz in a controlled chamber. The graphene-based sensor expressed high sensitivity with fast response and recovery times for both humidity and temperature with long stability and low hysteresis curves. The sensor was also tested on a metal body, which expressed a good response time. Moreover, the measured data of capacitance and resistance was analyzed with classical and neutrosophic analysis as an application of modern material statistics. It was observed that neutrosophic analysis is more flexible for analyzing the capacitance and resistance of the fabricated sensor.

Graphene is a 2D material with remarkable properties.     

Assessment of Bioceramic Sealer Retreatability and Its Influence on Force and Torque Generation

This study assesses the retreatability of TotalFill bioceramic (TFBC) and AH Plus (AHP) sealers and their impact on retreatment force and torque. Twenty-six premolar teeth with single oval canals were instrumented, obturated using the matched gutta-percha cone technique with one of the tested sealers, and then temporized. After a 6-month incubation at 37 °C and 100% humidity, the canals were retreated with the XP Shaper system. During retreatment, the generated force and torque were measured. Micro-CT scanning was run before and after the retreatment procedure to analyze the remaining obturating materials in the canals. The apically directed maximum force in AHP was higher than that in TFBC. The coronally directed maximum force and the maximum torque were comparable between the groups. A higher amount of remaining obturating materials was found in the AHP compared to that in the TFBC. Based on these findings, endodontic sealer had an influence on retreatability, and the TFBC showed less remaining obturating materials and lower retreatment forces in the apical direction compared to the AHP in extracted teeth with oval canals.     

Practise what you preach: the Interactive Whiteboard in preschool mathematics education

The Interactive Whiteboard (IWB) is now a common technological artefact in Swedish preschools and schools. This study examines preschool teachers’ thinking behind the embedding of IWB in the early years’ mathematics classroom and how preschool teachers structure their mathematical activities when using IWB. Two complementary empirical studies, that is, interviews and video observations, were conducted with four preschool teachers. The findings demonstrate that (just) having a positive attitude to technological artefacts like IWB is less likely to enrich the learning environment and lead to pedagogical change. This suggests that teachers’ IWB use is mostly informed by their pedagogical knowledge.     

Evaluation of Non Diseased Specified Outcome Measures in Hand Injuries to Assess Activity and Participation Based on ICF Content

The objective of the study is to provide information about non disease specified outcome measures which evaluate disability in patients who have impairments in hand and upper extremity and to find the extent to which they are evaluating “disability” based on ICF hand Core Set (activity limitation and participation restriction). MEDLINE, CINAHL, GOOGLE SCHOLAR , OVID and SCIENCE DIRECT databases were systematically searched for studies on non disease specified outcome measures used to evaluate upper extremity function; only studies written in English were considered. We reviewed titles and abstracts of the identified studies to determine whether the studies met predefined eligibility criteria (eg, non disease specified out come measures used in hand injured patients). All the outcome measures which had eligibility included. After full text review ,7 non disease specified outcome measures in hand were identified. Studies were extracted, and the information retrieved from them. All the outcome measures which had incuded, were linked with ICF hand core set disability part (activity and participation). All of them only linked to 16 (42 %) components of ICF hand Core Set, which were most activity and less participation from ICF. None of the non disease specified out come measures in hand injuries cover all domains of disability from the ICF Hand Core Set.     

Aneurysm formation of pericardial patch in Manouguian procedure

Pericardial patch has been used to repair cardiac defects; however, its strength as an aortoplasty patch to tolerate systemic pressure is a matter of debate. We report an aneurysmal dilatation of pericardial patch in aortoplasty. Our patient was a 56-year-old female known case of rheumatic heart disease that underwent redoes mitral and aortic valve replacements along with Manouguian aortoplasty at the age of 44?years old. After 2?months, she was readmitted with a diagnosis of endocarditis. Echocardiography revealed a small cavity in the posterior wall of the aorta. She responded to medical therapy and discharged in a good condition. Twelve years later, she was scheduled to undergo reoperation due to a severe paraprosthetic aortic valve leakage and a pericardial patch aneurysm. The leaking prosthetic aortic valve was explanted and the aneurysmal tissue was replaced with a polyethylene terephthalate patch.     

Congenital aortocaval fistula between right aortic sinus of Valsalva and superior vena cava: A rare case report

Thoracic aortocaval fistula is a very rare cause of left to right shunt. Drainage of fistula into the superior vena cava (SVC) is very uncommon. Clinical symptoms depend on the size of the shunt. We report a rare case of an asymptomatic 27‐year‐old woman with congenital aortocaval fistula to the SVC with a small amount of left to right shunt that was considered for serial medical follow‐up.     

Congestive heart failure as a rare cause of unilateral breast edema: A case report & review of the literature

Reported cases encountered difficulty in differentiating between inflammatory carcinoma and breast edema caused by congestive heart failure especially if the breast edema is unilateral. Our presented case is an elderly woman with unilateral breast edema due to congestive heart failure that was initially suspected to have breast cancer based on clinical findings. However imaging studies showed breast edema pattern with no definite underlying mass. This edema was resolved with standard treatment of heart failure. Congestive heart failure may be a possible cause of unilateral breast edema especially in a patient with background of congestive heart failure.