This paper gives a brief introduction to the four research methods for the study on thermal conductivity of cast irons, including experimental measurement, statistical analysis, effective medium ...theory and numerical simulation. Recent studies on the thermal conductivity of various cast irons are reviewed through the influence of alloying elements, structural constituents, and temperature. The addition of alloying elements is the main reason that restricts the thermal conductivity of cast irons, especially spheroidal graphite cast iron. The connectivity of graphite has a significant effect on the thermal conductivity of flake and compacted graphite cast irons, semiquantitative and quantitative analysis of this factor is a key and difficult point in the study of thermal conductivity of cast irons. The thermal conductivities of different types of cast irons show varying degrees of dependence on temperature. This phenomenon is the combination of graphite and matrix, rather than just depending on graphite morphology. The study of the relationship between individual phase and temperature is the focus of future research. These summaries and discussions may provide reference and guidance for the future research and development of high thermal conductivity cast irons.
To determine the effectiveness of a novel cast-saw alarm system in minimizing the number and duration of cast-saw blade-to-skin contacts.
Twenty orthopaedic residents removed a pair of long-arm casts ...applied to instrumented pediatric upper extremity models. The model and cast-saw were instrumented to detect blade to "skin" contact at a rate of 600 Hz. Each resident performed cast removal with and without the use of a cast-saw alarm, the order of which was randomized. Eleven additional "new" cast-saw users then removed pairs of casts, without and then with the cast alarm, to evaluate what effect the alarm would have on preventing blade-to-skin contact in users with no previous cast-saw experience. The number and duration of cast-saw touches were then evaluated. Statistical significance was determined paired 1-sided students t tests (number of touches).
For the residents (n=20), the total number of blade-to-skin contacts was 233. One hundred eighty-one blade-to-skin contacts without the alarm and 52 with the alarm (71% reduction) (t(19)=-3.42, P=0.001), averaging 6.45 more blade-to-skin contacts per cast without the alarm. The median blade-to-skin contact duration was 0.166 seconds without the alarm and 0.087 seconds with the alarm. This was a 48% reduction in contact time (P=0.073). For the inexperienced users (n=11), the total number of blade-to-skin contacts was 356, 324 blade-to-skin contacts without the alarm and 32 with the alarm (90% reduction) (t(10)=-2.78, P=0.009), averaging 26.5 more blade-to-skin contacts without the alarm. The median blade-to-skin contact duration for the novice was 0.313 seconds without the alarm and 0.1 seconds with the alarm (68% reduction). Contact time was reduced in both groups but failed to reach statistical significance. However, alarm use significantly reduced the number of touches of >0.5 seconds duration (62 vs. 3) in the novice group, P=0.0176. Blade-to-skin contact of >0.5 seconds were felt to represent touches that were more likely to result in thermal injury to a living patient.
Blade-to-skin contact can be reduced with the use of a cast-saw alarm. These effects appear most amplified in users with little prior cast-saw experience.
Not applicable.
The identification and proper characterization of pathologic renal intratubular casts can be an arduous task, especially since they often admixed with non-pathologic casts, obfuscating debris and ...inflammation. The list of pathologic intratubular casts is long, and they can be easily missed or misdiagnosed without a thorough understanding of their pathophysiology and morphologic variety. Correct characterization of tubular casts is important since each cast type has a unique pathogenic mechanism, with specific treatment and prognostic implications.
This review discusses the clinicopathologic characteristics of the six most common pathologic casts: light chain, hemoglobin, myoglobin, red cell, neutrophilic and bile casts. We also discuss hyaline and uromodulin casts, the commonly encountered "benign" cast types that share certain histologic features with pathologic casts. We limit the discussion to proteinaceous and cellular intratubular casts, with crystalline casts discussed in a separate review within the same journal issue.
While not exhaustive, this review covers pathogenesis, clinical and prognostic significance, and a practical discussion of the histomorphologic spectrum of each cast type, along with commonly encountered pitfalls.
In the past two years, significant progresses have been achieved in high-performance cast and wrought magnesium and magnesium alloys, magnesium-based composites, advanced cast technologies, advanced ...processing technologies, and functional magnesium materials, such as Mg ion batteries, hydrogen storage Mg materials, bio-magnesium alloys, etc. Great contributions to the development of new magnesium alloys and their processing technologies have been made by Chongqing University, Shanghai Jiaotong University, Chinese Academy of Sciences, Helmholtz Zentrum Geesthacht, Queensland University, Brunel University, etc. This review paper is aimed to summarize the latest important advances in cast magnesium alloys, wrought magnesium alloys and functional magnesium materials worldwide in 2018–2019, including both the development of new materials and the innovation of their processing technologies. Based on the issues and challenges identified here, some future research directions are suggested, including further development of high-performance magnesium alloys having high strength and superior plasticity together with high corrosion resistance and low cost, and fundamental research on the phase diagram, diffusion, precipitation, etc., as well as the development of advanced welding and joining technology.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Thermal injuries can occur during cast removal with an oscillating saw. The purpose of this study is to describe the effect of blade material, blade wear, and cast material on blade temperature.
...Short arm plaster and fiberglass casts were cured overnight and bivalved with either new or worn stainless-steel or tungsten-disulfide coated blades. Blade use was defined as removing 1 short arm cast. Blades used to remove more than 20 casts were defined as worn. Ten trials were performed with each combination of blade material, blade wear, and cast material, except for the combination of fiberglass and a worn stainless-steel blade due to complete erosion of cutting teeth. Thirty casts were removed with stainless-steel blades, and 40 casts were removed with coated blades. Blade temperature was measured continuously at 5 Hz using a T-type thermocouple and microcontroller board. A Mann-Whitney U test was used to compare the mean maximum temperature between groups.
For plaster casts, new and worn stainless-steel blades produced mean maximum temperatures of 51.4°C and 63.7°C ( P =0.003), respectively. New stainless-steel blades produced significantly higher mean maximum temperatures on fiberglass casts than plaster casts (95.9°C vs. 51.4°C, P <.001). For plaster casts, new and worn coated blades produced mean maximum temperatures of 56.9°C and 53.8°C ( P =0.347). For fiberglass casts, new and worn coated blades produced mean maximum temperatures of 76.6°C and 77.7°C ( P =0.653). As with new stainless-steel blades, new coated blades produced significantly higher mean maximum temperatures on fiberglass than plaster (76.6°C vs. 56.9°C, P <0.001). Mean maximum temperatures between new stainless-steel and coated blades during removal of plaster casts were 51.4°C and 56.9°C ( P =0.131), respectively. However, new coated blades demonstrated significantly lower mean maximum temperatures during fiberglass cast removal compared to new stainless-steel blades (76.6°C vs. 95.9°C, P =0.016).
Coated blades outperformed stainless-steel in nearly all combinations. We recommend limited use of stainless-steel blades to minimize blade temperatures during cast removal.
Appropriate selection of blade material and monitoring blade wear minimizes blade temperature during cast removal.
The most common cause of acute kidney injury (AKI) in multiple myeloma is light-chain cast nephropathy (LCCN), which consists of a light chain and Tamm-Horsfall protein (THP). We herein report a ...46-year-old woman with hypercalcemia and AKI. A renal biopsy showed crystalline casts, which were consistent with lambda light chains but not THP. Hydration therapy and treatment to lower her serum calcium concentration were initiated immediately. She subsequently received bortezomib-based anti-myeloma therapy and recovered successfully. This was a rare case of LCCN, suggesting that hypercalcemia may play a role in the development of crystalline LCCN.
The most common cause of acute kidney injury (AKI) in multiple myeloma is light-chain cast nephropathy (LCCN), which consists of a light chain and Tamm-Horsfall protein (THP). We herein report a ...46-year-old woman with hypercalcemia and AKI. A renal biopsy showed crystalline casts, which were consistent with lambda light chains but not THP. Hydration therapy and treatment to lower her serum calcium concentration were initiated immediately. She subsequently received bortezomib-based anti-myeloma therapy and recovered successfully. This was a rare case of LCCN, suggesting that hypercalcemia may play a role in the development of crystalline LCCN.
INTRODUCTION:Serial casting of children with early onset scoliosis (EOS) is an established treatment option. A break from cast treatment often called a “cast holiday,” (CH) is often allowed by some ...centers, particularly over the summer months. The impact of CHs on treatment duration or outcome has not been examined.
METHODS:Institution review board approved retrospective review of children treated for EOS with elongation derotation flexion (“Mehta”) casting at a children’s hospital between 2001 and 2016 with a minimum of 2 years’ follow-up. A CH was defined as a minimum of 4 weeks out of the cast, braced, or unbraced.The analysis was performed to determine the impact of a CH within the first 18 months of treatment. Separate analyses were performed for the entire cohort of children castedduring the study period, and then separately looking at idiopathic EOS in isolation. The impact of a CH was assessed in terms of the likelihood of achieving scoliosis <15 degrees at the final follow-up (“success”). Odds ratios were used to assess group differences between “success” ratios, and Student t tests assessed group differences for parametric data.
RESULTS:Ninety children met inclusion and exclusion criteria, 31 of whom took a CH during the first 18 months of treatment (34%). This included 59 patients with idiopathic EOS (66%), 18 with syndromic EOS, 5 congenital, and 1 neuromuscular. There were no statistically significant differences between CH and no CH groups.Forty-four percent of the no CH group achieved scoliosis <15 degrees at final follow-up, as opposed to 13% of the CH group, an odds ratio of 5.3 for success without a CH. When limited to children with idiopathic EOS, 56% achieved success in the no CH, versus only 22% in the group that took a CH, an odds ratio of 4.4 for success with no CH.
CONCLUSION:This study demonstrates that children treated for EOS with serial casting who take a CH within the first 18 months of treatment are less likely to achieve scoliosis <15 degrees than those who persist with treatment.
LEVEL OF EVIDENCE:Level III.
Motivated by (i) more and more interest in strong gravitational lensing by supermassive black holes due to the achievement of EHT observations, (ii) the ongoing popular topic on the possibility of ...Lorentz symmetry being broken in gravitation and its consequences, we will apply the Einstein bumblebee gravity with Lorentz violation (LV) to the study of strong gravitational lensing effect and the black hole shadow of slowly rotating Kerr-like black hole. In the strong gravitational lensing sector, we first calculate the deflection angle; then treating the slowly rotating Kerr-like black hole as supermassive M87* black hole, we evaluate the gravitational lensing observables (position, separation and magnification) and the time delays between the relativistic images. In the black hole shadow sector, we show the effect of LV parameter on the luminosity of the black hole shadow and photon sphere using the infalling spherical accretion. Moreover, we explore the dependence of various shadow observables on the LV parameter, and then give the possible constraint on the LV parameter by M87* black hole of EHT observations. We find that the LV parameter shows significant effect on the strong gravitational lensing effect, the black hole shadow and photon sphere luminosity by accretion material. Our results point out that the future generations of EHT observation may help to distinguish the Einstein bumblebee gravity from GR, and also give a possible constrain on the LV parameter.
•The strong gravitational lensing observables was evaluated by treating the rotating Kerr-like black hole as supermassive M87* black hole.•The effect of Lorentz Violation (LV) parameter on shadow observables and the possible constraint on the parameter has been disclosed.•The future generations of EHT observation may help to distinguish the Einstein bumblebee gravity from GR, and also give a possible constrain on the LV parameter.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
There is no consensus on which is the best way to maintain initial reduction of a distal radius fractures (DRFs). The aim of this study is to test the hypothesis that below elbow cast (BEC) is ...equivalent to above elbow cast (AEC) in maintaining initial reduction of DRFs. This paper will report on midterm results.
SLA-VER is a prospective, monocentric, randomized, parallel-group, open label, blinded endpoint evaluation non-inferiority trial (PROBE design) comparing the efficacy of AECs and BECs in DRFs conservative treatment in terms of loss of radial height (RH), radial inclination (RI) and volar tilt (VT) during cast immobilization (average 35 days) of 353 consecutive DRFs. Non-inferiority thresholds are 2 mm for radial height, 3Åã for radial inclination and 3Åã for volar tilt. Study population will be 353 patients, randomized into 2 groups (AEC vs BEC). One-hundred patients have completed the study so far.
Patients in BEC group lost 1,75 mm of RH, 2,9Åã of RI and 4,5Åã of VT over the course of cast immobilization. Patients in AEC group lost 1,71 mm of RH, 2,2Åã of RI and 4,8Åã of VT. Raw differences between average loss of RH, RI, VT during treatment between study groups were respectively 0,04 mm, 0,7Åã and 0,3Åã. Logistic and ANCOVA models have been used to correct for confouding variables.
Difference of loss of RH, RI and VT between the two groups are all below the non inferiority thresholds. Cast type does not seem to affect maintenance of reduction in conservatively managed DRFs.
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