Inexperience in cast removal in the pediatric population can lead to a range of cast saw-related injuries. The purpose of this study is to validate a simple simulation-based wax model that is both ...reproducible and economical while providing a valuable tool that can be used to grade cast saw use performance in trainees.
Cylindrical wax models were used as an analog for a pediatric upper extremity. The wax models were casted in a proscribed reproducible fashion for consistency. Two groups, the first consisting of 15 experienced cast saw users and the second consisting of 15 inexperienced individuals, completed 4 sequential longitudinal cuts in the casted wax models. After removal of the cast material, marks left by the cast saw in the wax were counted and measured. Indentation length, maximum depth, and maximum width were measured on each wax model. The total length of the cast saw indentations per cast saw user was also calculated.
For the inexperienced cast saw users, the average total length of the cast saw indentations was 526.56 mm, average maximum depth was 1.91 mm, and average maximum width was 3.24 mm. For experienced cast saw users, the average total length of the cast saw indentations was 156.57 mm with an average maximum depth of 1.06 mm and average maximum width of 2.19 mm. Receiver operating characteristic curves of the total number of errors, total error length, maximum error depth, and maximum error width show effective discrimination of experienced from inexperienced trainees.
This study provides valid evidence supporting a cost-effective, time-efficient, and easily reproducible educational simulation module that can objectively measure cast saw the performance in trainees. This model demonstrates construct validity and can distinguish novice from experienced cast saw users. It is sensitive enough to identify mistakes even in the most experienced cast saw users, creating a platform that can provide performance-based feedback to cast saw users of all experience levels.
Level III-diagnostic test.
In this study, the potential of Fesub.3Al coating material as an environmentally friendly alternative to coatings containing critical elements for brake discs was investigated. A buffer layer of ...Cr–Mo steel (Ferro 55) that was about 500 µm thick was applied on a gray cast iron disc to enhance the coating quality and prevent the formation of hot cracks during solidification. The microstructural analysis of the cross-section of the coating showed that the buffer layer diffused into the Fesub.3Al coating, forming a combination of Fesub.3Al, Fe, and Fesub.3AlCsub.0.5 phases. The tribological properties of the Fesub.3Al-coated disc were evaluated using pin-on-disc tests against two different copper-free friction materials extracted from commercial brake pads. The wear results show a coefficient of friction comparable to that of an uncoated disc (≈0.55), but with a reduction in particulate matter (PM) emissions, which decreased from 600 to 476 #/cmsup.3. The last issue is an interesting aspect that is gaining increasing importance in view of the upcoming international standards.
Purpose
The aim of this study was to investigate whether short-arm fiberglass cast (SAC) immobilization provides fracture stabilization comparable to that of long-arm cast (LAC) treatment of ...displaced distal forearm fractures after closed reduction in paediatric patients.
Methods
A prospective, randomized, controlled trial of children aged four to 16 years (mean 9.9 years) was designed with a sample of 120 children, whose size was set a priori, with 60 treated with SAC and 60 with LAC. The primary outcome was fracture stability and rate of loss of reduction. The secondary outcome analysis evaluated duration of analgesic therapy, restriction in activities of daily life, and the duration until patients regained normal range of motion in the elbow.
Results
No statistically significant differences were found between the two groups in loss of reduction or duration of analgesic therapy. In contrast, the duration until normal range of motion in the elbow was regained was significantly longer in the LAC group (median 4.5 days,
P
< 0.001). Restriction in activities of daily life did not differ significantly between the two groups except for the item “help needed with showering in the first days after trauma” (SAC 60%, LAC 87%,
P
= 0.001).
Conclusion
Fracture immobilization with short-arm fiberglass cast in reduced distal forearm fractures is not inferior to long-arm casts in children four years and older, excluding completely displaced fractures. Furthermore, short-arm casting reduces the need for assistance during showering.
Trial registration
NCT03297047, September 29, 2017
Display omitted
•Boride particles have lamellar structure, composed of varied boride phases and B2 phase.•B2 phase exist in curved but not in straight borides, reactions involved during formation are ...different.•Stacking faults is closely related to the transition between TiB2, Ti3B4 and Bf-TiB.•B27-TiB tends to grow alone because of the difficulty of the transition between B27 and other boride structures.
Borides with varied morphologies and structures obtained by changing B content in as-cast Ti-45Al-2Mn-2Nb alloys are investigated. With the increase of B content, morphologies of borides change from curved to straight, and flake shape, ribbon shape, needle/rod shape, and blocky appear in turn. Curved boride particles have a lamellar structure composed of TiB2 and B2 layers, accompanied by the random appearance and distribution of Ti3B4 and Bf-TiB layers. Except for the absence of the B2 layer, straight needle-like and blocky boride particles have roughly the same structure as curved boride particles, revealing that the formation of curved boride particles is accompanied by divorced eutectic with the matrix and internal irregular eutectic, while no eutectics occurs in straight boride particles. The lack of B atoms during solidification in alloys with lower B content results in a less regular structure and higher stacking fault density of curved boride particles compared to straight boride particles in alloys with higher B content. In addition, some needle-like boride particles are observed to have pure B27-TiB structure without intergrowth. The difference in morphologies and structures can be attributed to the difference in formation mechanism and crystallographic structures of the borides.
The purpose of this paper is to describe the technique of making casts
using alginate compound for negative and dental stone plaster for
positive impressions. With certain modifications a cast could ...be made
of any part of the body and one can make a museum of interesting cases.
Casts serve as useful teaching material especially in cleft lip and
palate patients to study the effect of surgery on growth and
development of the cleft lip-palate-nose complex in relation to the
remaining face. It also helps in planning reconstruction in cases of
facial defects, recording serial changes in multistage surgery,
pre-operative and post-operative comparison as in rhinoplasty, ear
reconstruction, hand etc; for comparing results before and after
treatment in keloid and hypertrophic scars, fabrication of implants and
preparation of prosthesis. In spite of newer modalities like 3-D
imaging and stereolithography, the usefulness of this old technique in
certain interesting cases can not be denied.
•Fatigue crack growth of spheroidal and compacted graphite cast irons are studied.•Graphite of cast irons are observed with the help of X-ray microtomography.•The crack propagation rate is larger in ...compacted graphite cast iron than in spheroidal graphite cast iron.•Graphite fracture is the main mode of fatigue crack propagation for the compacted graphite cast iron.
The present paper focuses on the fatigue life of a Compacted Graphite cast Iron (CGI) as compared to a Spheroidal Graphite cast Iron (SGI). Fatigue crack growth laws have been determined with digital image correlation. Main difference between the materials is that cracks propagate faster in the CGI than in the SGI. X-ray tomography was also used in order to assess graphite morphologies and crack shapes. A complex morphology was observed for the vermicular graphite with rounded edges that limit notch effects. The crack spreads easily in CGI via a quasi cleavage mechanism and by propagating through graphite mainly by breaking the vermicules.
The article proposes the use of ADI cast iron as an alternative material solution for 30CrMo12 cast steel in the construction of friction systems intended for use in tribocorrosion conditions with ...the presence of an abradant. An independent evaluation of the resistance to tribocorrosion of the analyzed materials was made using two types of tests: a laboratory and industrial one. The industrial test was carried out using an original research stand. It made it possible to map the real operating conditions of the chain wheels of the scraper conveyor transporting a mixture of mineral abrasive and salt water. A standard tribotester with a ball-on-plate system and a model corrosion environment of 3.5% NaCl were used in the laboratory test.
The research results included in the article indicate that ADI cast iron has a higher resistance to tribocorrosion than 30CrMo12 cast steel despite lower initial hardness and similar corrosion resistance. This effect may be caused by the ability to strengthen the near-surface layers of cast iron due to frictional interactions.
The article also showed that the results of the comparative assessment of the tribocorrosion resistance of various materials obtained in the model systems (the laboratory test) can be as effective as the tests of real machine systems (the industrial test).
•Proposition of ADI cast iron as a replacement for 30CrMo12 cast steel for friction nodes in tribocorrosion conditions.•ADI cast iron tribocorrosion resistance was shown to be better than 30CrMo12 cast steel.•The possibility of strengthening the ADI cast iron surface layer in frictional coupling during tribocorrosion.•Analysis of the effectiveness of laboratory and industrial tests in the field of comparative evaluation of materials.•An original test stand was used to test the tribocorrosive wear of scraper conveyor elements under real operating conditions.
Genetic engineering technologies are essential not only for basic science but also for generating animal models for therapeutic applications. The clustered regularly interspaced short palindromic ...repeats (CRISPR)-CRISPR-associated protein (Cas) system, derived from adapted prokaryotic immune responses, has led to unprecedented advancements in the field of genome editing because of its ability to precisely target and edit genes in a guide RNA–dependent manner. The discovery of various types of CRISPR-Cas systems, such as CRISPR-associated transposons (CASTs), has resulted in the development of novel genome editing tools. Recently, research has expanded to systems associated with omega RNAs including ancestral CRISPR-Cas and eukaryotic Fanzor systems, which are expected to complement the conventional CRISPR-Cas systems. In this review, we briefly introduce the features of various CRISPR-Cas systems and their application in diverse animal models.
3.6wt%C-2.5wt%Si 구상흑연주철을 오스템퍼링 열처리하는 동안 프로세싱 윈도우에 미치는 오스템퍼링 온도, 오스테나이트화 처리 온도와 시간, 구리 첨거량 그리고 사전 열처리의 영향을 연구하였다. 350℃의 오스템퍼링 처리 온도에서 최대 프로세싱 윈도우를 얻었다. 프로세싱 윈도우는 오스테나이트화 처리 온도가 850에서 900℃로 증가함에 따라 ...증가하였으나 950℃로 증가하면 오히려 감소하였다. 프로세싱 윈도우는 오스테나이트화 처리 시간이 30분에서 2시간까지 증가함에 따라 증가하였다가 4시간일 때 감소하였다. 최적 오스템퍼링 처리 조건은 900℃에서 2시간인 것으로 나타났다. 프로세싱 윈도우는 구리 첨가량이 0.0~0.8wt% 범위에서 증가함에 따라 증가하였다. 프로세싱 윈도우는 주방 상태의 구상흑연주철에 비하여 사전 노르말라이징 처리로 증가하였으며 사정 어닐링 처리로 감소하였다.
The effects of austempering temperature, austenitizing temperature and time, added copper content and prior heat-treatment on the processing window of 3.6wt%C-2.5wt%Si ductile cast iron during austempering. The maximum processing window was obtained at 350℃ of austempering temperature. The processing window was increased with increased austenitizing temperature from 850 to 900℃; however, it decreased at 950℃. The processing window was increased with increased austenitizing time from 0.5 to 2 hours and rather decreased for 4 hours. The optimum condition of austenitizing was obained at 900℃ for 2 hours. The processing window was increased with copper content added in the range of 0.0~0.8wt%. The processing window was increased by prior normalizing heat-treatment and decreased by prior annealing in comparison with that for the as-cast state,
The paper reviews original data obtained by the authors, from recent separate publications, specifically concerning graphite formation in the solidification pattern of industrial cast irons, ...focussing on grey iron versus ductile iron. Additional unpublished data and selected data from literature are represented in the paper. Complex compounds act as nucleation sites in commercial cast irons, generally in a three-stage graphite formation, but with different sequences: (1) first micro-compound formation is oxide/silicate in grey iron and sulphide in ductile iron; (2) the second compound nucleates on the first one, as complex manganese sulphide in grey iron and complex silicates in ductile iron; (3) graphite nucleation on the sides of stage 2 compounds, which have low crystallographic misfit with graphite. Resulphurization (Mn/S control), preconditioning with strong oxide forming elements (Al, Zr), more potent inoculants and inoculation enhancement with S, O and oxy-sulphide forming elements were found to be beneficial treatments especially in critical solidification conditions
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