Height Shrinkage Research Articles

Age estimation at death in individuals over 50 using CT images: An innovative anthropological approach

ObjectivesThe aim of the present work is to develop a novel method for predicting age in individuals over 50 years old, utilizing regression models. MethodsThe conducted study is of an analytical cross-sectional nature, involving a sample of 44 young subjects and 107 elderly subjects. The necessary data for this research were extracted from "The New Mexico Decedent Image Database." Based on the phenomenon of height shrinkage with age, we created models for young subjects and applied them to elderly subjects, allowing us to extract the variables. ResultsWe obtained highly encouraging results with an R2 of 0.73, a mean absolute error of 3.94, and stable cross-validation. We used a Student's t-test, which demonstrated no significant difference between predicted and actual values (p-value >0.05). We also conducted a learning curve analysis and examined residuals against predicted values. This suggests that the forecasts are accurate, with no significant bias in predictions. ConclusionThis work has allowed us to conclude that it is possible to reliably estimate the age of subjects over 50, taking into account age-related physiological and pathological changes.

Aramid Honeycomb Cores under Constant Pressure: Unveiling the Out-of-Plane Compression Deformation.

The primary challenge during the secondary bonding process of full-height honeycomb sandwich structures is the aramid honeycomb core's height shrinkage. This paper systematically investigated the height evolution behavior of the honeycomb core by using a creep testing machine. The results showed that the out-of-plane compression deformation curve of aramid honeycomb cores is mainly divided into three stages: the dehumidification stage, the pressurization stage and the creep stage. Under conditions of high temperature and pressure, height shrinkage was attributed to the dehydration caused by moisture infiltration, and the compression creep resulted from the slippage of polymer molecular chains. Dehydration shrinkage is stable, whereas compression creep reflects typical viscoelastic polymer characteristics. By employing the viscoelastic Burgers mechanical model and applying the nonlinear surface fitting method, the total height shrinkage deformation behavior of the aramid honeycomb core during the curing process can be accurately predicted by summing the above three stages. This research contributes valuable insights for the manufacturing process of honeycomb sandwich structures.

Effects of Incorporating Ionic Crosslinking on 3D Printing of Biomass-Fungi Composite Materials.

Biomass-fungi composite materials primarily consist of biomass particles (sourced from agricultural residues) and a network of fungal hyphae that bind the biomass particles together. These materials have potential applications across diverse industries, such as packaging, furniture, and construction. 3D printing offers a new approach to manufacturing parts using biomass-fungi composite materials, as an alternative to traditional molding-based methods. However, there are challenges in producing parts with desired quality (for example, geometric accuracy after printing and height shrinkage several days after printing) by using 3D printing-based methods. This paper introduces an innovative approach to enhance part quality by incorporating ionic crosslinking into the 3D printing-based methods. While ionic crosslinking has been explored in hydrogel-based bioprinting, its application in biomass-fungi composite materials has not been reported. Using sodium alginate (SA) as the hydrogel and calcium chloride as the crosslinking agent, this paper investigates their effects on quality (geometric accuracy and height shrinkage) of 3D printed samples and physiochemical characteristics (rheological, chemical, and texture properties) of biomass-fungi composite materials. Results show that increasing SA concentration led to significant improvements in both geometric accuracy and height shrinkage of 3D printed samples. Moreover, crosslinking exposure significantly enhanced hardness of the biomass-fungi mixture samples prepared for texture profile analysis, while the inclusion of SA notably improved cohesiveness and springiness of the biomass-fungi mixture samples. Furthermore, Fourier transform infrared spectroscopy confirms the occurrence of ionic crosslinking within 3D printed samples. Results from this study can be used as a reference for developing new biomass-fungi mixtures for 3D printing in the future.

3D-hexagonhelical TiO2-monoliths: Design, printing process and solar photoactivity

Solid 3D titanium dioxide (TiO2) structures with hexagonhelical (3DHH) geometry were possible to achieve through additive printing technology. The monoliths acquired the shape and hydrodynamic requirements of a tubular solar CPC photoreactor. The optimum printing parameters were achieved with a 1.2 mm ∅ nozzle, and a dosing rate of 0.87 ml/min, with a duration of 10 min per complete manufactured piece. The heat treatment (Tam⇨180°C30 min ⇨250°C30 min ⇨350°C30 min) applied to the printed pieces does not modify the active anatase/rutile weight ratio (82.9/17.1). On the contrary, the mechanical resistance improved remarkably after the heat treatment: a compressive stress 5 folds higher (307.81 ± 15.31 kPa) was observed in comparison with the pieces without heat treatment. The most important shrinkage in diameter and height are generated throughout the dehumidification process at room temperature of free drying for 24 h (Δ∅ = 3.86 ± 0.43 mm and Δh = 3.78 ± 0.16 mm respectively). In contrast, the size changes were insignificant after heat treatment (Δ∅ = 0.075 ± 0.12 mm and Δh = 0.15 ± 0.01 mm). The microscopic morphology shows changes on the surface of the monoliths with deagglomerated flat shapes after heat treatment. Persistent degradation of the IBP model compound was observed over 10 cycles under solar irradiation in a laboratory-scale photoreactor using twelve heat-pretreated 3DHH-TiO2 monoliths. In addition, 10 cycles were compared for monoliths without thermal processing. Including both cases (monoliths with and without heat treatment), 90% of the solar experiments degraded between 50 and 95% of the initial IBP concentration per cycle (200 mg/L).The resistance to erosion acquired by heat treatment allows mechanical stability for photocatalytic purposes while maintaining significant solar activity. The commercial use of heterogeneous photocatalytic processes on an industrial scale could soon be achieved with the support of 3D additive manufacturing.

Research on deposition toolpath planning and laser head Z-axis rising height setting for directed energy deposition

In this study, the biggest goal was using laser directed energy deposition (L-DED) process to fabricate a solid blade part. In the process of CAD modeling, a blade model was built by sweeping a blade cross-section and twisting 10° simultaneously, which made it to have overhanging and tilting features. So, to select an appropriate deposition toolpath was the most important thing. The deposition toolpath in this study was decomposed into contour and field toolpaths. First of all, a cuboid part model of which the geometry was simpler was created to test toolpath planning approaches. The results recommended to use “Fixed rising height per layer with proper laser head rising height (Z-offset setting)” or “Spiral” approaches to plan contour toolpaths. For field toolpaths, “Reciprocating zigzag” planning approach was suggested and it needed to adjust the cladding angle to fit the cross-section of the parts. According to the test results of cuboid part fabrications, the contour of the target blade part was successfully manufactured with a 50% Z-offset setting and the spiral toolpath. The solid blade fabrication was also finished with a fixed rising height per layer with a 50% Z-offset setting and 45° reciprocating zigzag toolpath. In addition, the relationship between the Z-offset setting and the dilution was investigated through experiments. A conjecture that a height shrinkage of an old layer caused by thermal deformation is equal to the single-layer deposition dilution was proposed. Based on this conjecture, users can improve L-DED deposition results by setting the Z-offset as “the product of single-track height and the degree of shrinkage of an old layer height.” By combining the predictive value of dilution surface fitting model with the conjecture, it can be easier to get better LDED deposition quality.

Volumetric behavior of an unsaturated clayey soil-rock mixture subjected to freeze-thaw cycles: A new insight

The volumetric behavior of clayey soil-rock mixtures under freeze-thaw action is very important for the design of anti-frost heave in cold-region engineering. However, existing studies mainly focus on the effect of freeze-thaw cycles on the global volume change of fine-grained soils, and few attempts have focused on mixed soils with coarse particles such as clayey soil-rock mixtures. In this study, a series of laboratory freezing-thawing tests were conducted to investigate the effects of the freeze-thaw cycles and rock content on the global volume change, diameter change, and height change behaviors of cylindrical soil-rock mixture samples. The results demonstrate that: 1) the volumetric behavior of the samples under freeze-thaw cycles is closely related to the rock content, which is mainly because different rock contents dominate the different skeleton structures. 2) For samples with 0%, 10%, and 30% rock content, the global volume of compacted samples shows shrinkage upon freezing and expansion after thawing. However, the global volume of the sample with 50% rock content began to shrink after three freeze-thaw cycles. 3) Compared with the samples not subjected to freeze-thaw weathering, the height of samples with 0%, 10%, and 30% rock content shows shrinkage upon freezing and expansion after thawing no matter what the number of freeze-thaw cycles is. However, the diameter and height of the sample are always shrinking, regardless of whether they are frozen or thawed. 4) Upon freezing, the shrinkage of the sample's global volume and diameter tends to decrease linearly with the increase of rock content, but the shrinkage of the sample's height is not sensitive to the change of rock content. Upon thawing, the global volume and height of the sample exhibit a trend from expansion to contraction with increasing rock content, but the shrinkage of the diameter of the sample is nearly the same no matter what the rock content is. Furthermore, a computed tomography (CT)-based mesoscopic structural characteristic and two idealized schematic diagrams well illustrated the evolution mechanism of the volumetric behavior of an unsaturated clayey soil-rock mixture subjected to freeze-thaw cycles.

The effect of particle size distribution on the microstructure and properties of Al2O3 ceramics formed by stereolithography

Stereolithography (SL) shows advantages for preparing alumina-based ceramics with complex structures. The effects of the particle size distribution, which strongly influence the sintering properties in ceramic SL, have not been systematically explored until now. Herein, the influence of the particle size distribution on SL-manufactured alumina ceramics was investigated, including bending strength at room temperature, post-sintering shrinkage, porosity, and microstructural morphology. Seven particle size distributions of alumina ceramics were studied (in μm/μm: 30/5, 20/3, 10/2, 5/2, 5/0.8, 3/0.5, and 2/0.3); a coarse:fine particle ratio of 6:4 was maintained. At the same sintering temperature, the degree of sintering was greater for finer particle sizes. The particle size distribution had a larger influence on flexural strength, porosity and shrinkage than sintering temperature when the particle size distribution difference reached 10-fold but was weaker for 10 μm/2 μm, 5 μm/2 μm and 5 μm/0.8 μm. The sintering shrinkage characteristics of cuboid samples with different particle sizes were studied. The use of coarse particles influenced the accuracy of small-scale samples. When the particle size was comparable to the sample width, such as 30 μm/5 μm and 5 mm, the width shrinkage was consistent with the height shrinkage. When the particle size was much smaller than the sample width, such as 2 μm/0.3 μm and 5 mm, the width shrinkage was consistent with the length shrinkage. The results of this study provide meaningful guidance for future research on applications of SL and precise control of alumina ceramics through particle gradation.

Long-Term Performance of Untreated Fresh Autologous Pericardium as a Valve Substitute in Pulmonary Position

Background:Pulmonary regurgitation is imminent after transannular patch (TAP). We analyze the long-term performance of untreated autologous pericardium (UAP) as valve substitute at pulmonary position in patients requiring TAP.Material and Methods:This cross-sectional study include patients operated between 2007 and 2012 (n = 92). A sample of 19 patients was selected for this study which had a follow-up of more than 3 years. This includes patients with no TAP (n = 4) and with TAP and valve substitute, a monocusp (n = 11) or a tricuspid valve (n = 4) at neopulmonary annulus. Patients underwent echocardiography for assessment of right ventricle function and 18 fluoro-deoxyglucose PET CT scan for measurements of valve substitute at neopulmonary annulus. The target to blood ratio (TBR) of uptake of glucose by monocusp was measured at the cooptation edge of the neopulmonary valve.Results:The median age of the patients is 14 (9 – 37). RV function is preserved (TAPSE 18.9 (10.6 – 22.8)) at a mean follow-up of 4 years (3-9). The measurements of monocusp shows a shrinkage in height of the cusp by 35.5% (70% – 1.0%) and length by 7% (-44% - +104%). There was less shrinkage observed in patients below 15 years of age. The TBR of monocusp was 0.945 (0.17 – 3.35) with a strong correlation between the TBR values of aortic valve leaflet and monocusp leaflet of same patient.Conclusion:The UAP is functional and successful as a valve substitute at neo pulmonary annulus at long-term follow-up. It has resisted calcification and has shown uptake of glucose in physiological limits.

An Investigation Into Magnetic Properties, Sintering Shrinkage Characteristics, and Formability of Isotropic Barium Ferrite Permanent Magnets

In this study, traditional ceramic process was used to prepare isotropic barium-based ferrite permanent magnets. The lower grade iron oxide powder (Fe₂O₃) manufactured by China Steel Corporation (CSC) was used as the main raw material to prepare calcined magnetic powders with different Fe₂O₃/BaCO₃ mole ratios (5.3&#x2013;5.65). It can be seen from the experimental results that the remanence (<inline-formula> <tex-math notation="LaTeX">$B_{\mathrm {r}}$ </tex-math></inline-formula>) decreases with the increase of mole ratio, but the intrinsic coercivity (<inline-formula> <tex-math notation="LaTeX">$_{\mathrm {i}}H_{\mathrm {c}}$ </tex-math></inline-formula>) shows the opposite trend. On the other hand, the sintering radial shrinkage rate (Sh-D) and sintering height shrinkage rate (Sh-H) both decrease as mole ratio increases, but the required molding pressure is higher. On condition of Fe₂O₃/BaCO₃ mole ratio &#x003D; 5.4, Fe₂O₃ &#x003D; 81.38 wt&#x0025;, BaCO₃ &#x003D; 18.62 wt&#x0025;, the magnetic properties of the final sintered magnet can reach: <inline-formula> <tex-math notation="LaTeX">$B_{\mathrm {r}}$ </tex-math></inline-formula> &#x003E; 2250 G, <inline-formula> <tex-math notation="LaTeX">$_{\mathrm {b}}H_{\mathrm {c}}$ </tex-math></inline-formula> &#x003E; 1950 Oe, <inline-formula> <tex-math notation="LaTeX">$_{\mathrm {i}}H_{\mathrm {c}}$ </tex-math></inline-formula> &#x003E; 3300 Oe, (<i>BH</i>)_max &#x003E; 1.15 MGOe, which are obtained on the basis without expensive lanthanum and cobalt. In terms of the operability, the sintering shrinkage rate Sh-D &#x003C; 15.1&#x0025; and required molding pressure of magnetic powder &#x003C; 2.5 ton/cm² both meet the specifications of the permanent magnet industry. Above results successfully overcome high-cost technical bottlenecks in the past in order to achieve high characteristics and formability, and comprehensively improve magnetic properties, operability, and production efficiency. The low-cost isotropic barium-based ferrite permanent magnets with good magnetic properties and operability realized in this work have been practically used in high-efficiency small automobiles motors, such as electric rearview mirror motor.

Efficient Detection of Hyperkalemia with Highly Transparent and Ion-Recognizable Hydrogel Grating Sensors

A novel detection method based on highly transparent and ion-recognizable hydrogel grating sensors is developed for efficient diagnosis of hyperkalemia in this work. The proposed hydrogel gratings are made of poly(N-isopropylacrylamide-co-benzo-15-crown-5-acrylamide) (poly(NIPAM-co-B15C5Am)) networks by using tetra-arm-polyethylene-glycol-acrylamide (tetra-arm-PEGAAm) as a macromolecular cross-linker. The macromolecular cross-linker tetra-arm-PEGAAm can prevent the microstructure inside the poly(NIPAM-co-B15C5Am) hydrogel networks changing from the homogeneous state to the heterogeneous state during the response processes, which ensures the high transparency of hydrogel gratings as well as the strong laser intensity through the diffraction gratings during the response processes. The pendent crown ether 15-crown-5 units on the polymer networks in hydrogel can specifically recognize K+ to form stable 2:1 “sandwich” host–guest complexes, which cause the height shrinkage of hydrogel gratings. By using a simple optical detection system, the proposed poly(NIPAM-co-B15C5Am) hydrogel grating sensor can realize a highly selective and sensitive detection of K+ concentrations in both water and real human serum. Due to the specific host–guest complexation between crown ether 15-crown-5 and K+, the detections of K+ concentrations in aqueous solutions are nearly not interfered by other metal ions. Furthermore, because of the rapid response of the nanostructured poly(NIPAM-co-B15C5Am) hydrogel gratings, the diagnosis of hyperkalemia can be achieved within 3 min. The proposed smart hydrogel grating sensors in this work can be applied for rapid and efficient detection of hyperkalemia, and the results in this work provide valuable guidance for the development of novel smart sensors.

Development of 3D Slurry Printing Technology with Submersion-Light Apparatus in Dental Application

This study proposes an innovative three-dimensional printing technology with submersion-light apparatus. A zirconia powder with an average particle size of 0.5 µm is mixed with 1,6-Hexanediol diacrylate (HDDA) and photo-initiator to form a slurry. The weight percentage of zirconia powder to HDDA is 70:30 wt.%. A light engine box is submerged in a slurry and emits a layered pattern to induce photopolymerization and transform a slurry into a printed green body. Green body sintering parameters for the first and second stages are 380 °C with a holding time of 1.5 h and 1550 °C with a holding time of 2 h. The sintered parts’ length, width, and height shrinkage ratios are 29.9%, 29.7%, and 30.6%. The ball milling decreases the powder particle size to 158 ± 16 nm and the mean grain size of the sintered part is 423 ± 25 nm. The sintered part has an average hardness of 1224 (HV), a density of 5.45 g/cm3, and a flexural strength of 641.04 MPa. A three-unit zirconia dental bridge also has been fabricated with a clinically acceptable marginal gap.

Dual-purpose ability of barley and wheat at drought and heat stress conditions

Dual-purpose barley and wheat production is a valuable resource to fill feed gaps and grain production, but availability at drought and heat stress conditions is still not clearly studied. Two experiments were conducted at semi-controlled green house to determine biomass production at vegetative stages, chlorophyll content and grain yield. Experiment 1 consists of four clipping treatments on wheat, i.e. one, two, three times clipping and un-clipping control. Experiment 2 combined two clipping treatments (one clipping and un-clipping) and two levels of water (low: 40 % of field capacity; normal: 85 % of field capacity) on barley. Wheat grain yield was severely affected by increasing clipping number under heat stress. Total biomass at one clipping was the same level as control treatment. Although physiological maturity was delayed 8 days from control to 3 times clipping application, biomass and yield remained below the control application due to shrinkage in plant height and other organs size. Clipping and water levels at barley significantly impacted biomass and plant height, but all traits were not related by interactions clipping x water level. The clipping application in heat stress reduced total biomass by 21.3 and 30.4 % in well-watered and dry conditions, respectively. Contrary to what is expected, it seems clear to obtain satisfactory forage and grain yield by optimizing the management technique, growing in dual-purpose production in wheat and barley in warm environments.

Experimental and kinetic studies on ash fusion behavior: a high‐precision acquisition method for ash fusion temperatures

AbstractAsh fusion characteristics including ash properties and morphological changes in high‐temperature fusion test were studied among four types of fuels comprising two woody biomass, three straw biomass, two bituminous coals, and three biomass/coal mixtures. On the basis of ash fusion behavior and kinetic analysis of the ash melting process, a high‐precision acquisition method for ash fusion temperatures (AFTs) was developed. First, a reading index of AFTs was proposed; that is, in high‐temperature fusion test, initial deformation temperature (IDT), softening temperature (ST), and fluid temperature (FT) could be identified by the height shrinkage of 38%, 86%, and 98%, or the area shrinkage of 50%, 77%, and 97%, respectively. Kinetic analysis conducted on height/area shrinkage indicated that activation energy was highly related to temperature difference among IDT, ST, and FT, and low activation energy facilitated the enlargement of the temperature differences of ST‐IDT and FT‐ST. XRD patterns illustrated low activation energy had a promotion effect on the generation of higher melting substances such as KAlSi3O8 and CaSiO3, causing the elevation of the ST and FT. At last, a calculation method for AFTs based on activation energy and average height/area shrinkage was performed, which had high repeatability within an average error of ~6°C.

On the characterization of the shrinkage behavior and soil-water retention curves of four soils using centrifugation and their relation to the soil structure

In this study, a consistent centrifuge procedure was applied to four soils. The height shrinkage, bulk density increase, soil shrinkage curve (SSC), and soil-water retention curve (SWRC) of the soils were analyzed. Scanning electron microscopy (SEM) tests and image processing techniques were adopted to qualitatively and quantitatively investigate the microstructure of the soils with different bulk densities. The results showed that under a matric suction ranging from 0 to 2000 kPa, the bulk density increased from an initial value of 1.30 g/cm3 to 1.60, 1.72, 1.61, and 1.57 g/cm3 for the soils retrieved from Chanhe, Qingyang, Yan’an, and Lvliang, respectively, resulting in corrected SWRCs considering soil shrinkage that was higher than the uncorrected SWRCs, consistent with previously published work. However, this difference was effectively reduced by retesting the soil samples. A reduction in water volume resulted in the same reduction in the bulk soil volume in the normal shrinkage state, while a shrinkage rate higher than one was found with increasing soil drying. More hydraulically active and connected macropores were detected in the low-density soil. The maximum pore diameter, total pore area ratio (PAR), pore size, and number distribution considerably changed with increasing density. The captured microstructural information is beneficial for the interpretation of the shrinkage behavior and hydraulic properties of soil.

Study on shearing shrinkage properties of multilayered biaxial weft knitted fabrics

In order to know the shearing shrinkage properties of multilayered biaxial weft knitted (MBWK) fabrics, the change rule of forming angle, the number of fibers at different forming height and shearing shrinkage were studied, respectively. Through the experiment of MBWK fabrics draping on cylinder and cube, the results show that the number of fibers increases with the increase of forming height, and the fiber volume content reaches the maximum when the forming height reaches the maximum. Besides, the shearing shrinkage is positively correlated with forming height and negatively correlated with the cylinder diameter and the cross-section length of the cube. The obtained formula of shearing shrinkage can be used to evaluate the formability of fabrics as the theoretical results are in good agreement with the experimental data.

Effects of Solvent Debinding on the Microstructure and Properties of 3D-Printed Alumina Ceramics.

Solvents assist in the debinding of stereolithography-based 3D-printed alumina green bodies. The green bodies subsequently undergo thermal debinding and sintering to obtain alumina ceramics. In this study, several solvents were tested, including polyethylene glycol, oxalic acid, ammonium hydroxide, ethyl alcohol, methyl methacrylate, butyl acetate, dimethyl carbonate, methanol, ethyl acetate, and sec-butyl alcohol. The tested solvents during the debinding process showed different effects on microstructure and properties of 3D-printed alumina ceramics due to the variable aspects of their solubility toward the binders. The microstructure of the samples changed significantly after green bodies underwent solvent debinding, thermal debinding, and sintering, leading to loose spongy structures, porous aggregates, and compact structures, respectively. Shrinkage, bulk density, and open porosity changed slightly due to the debinding function of different solvents. Polyethylene glycol-impregnated samples displayed the minimum shrinkage in length direction (5.3%). Ethyl alcohol-impregnated sample showed minimum shrinkage in width (4.8%) and height (11.5%) directions. Ammonium hydroxide-impregnated samples exhibited minimum bulk density (2.8 g/cm3) and maximum open porosity (28.3%). Dimethyl carbonate-impregnated samples presented minimum flexural strength (32.6 MPa), and oxalic acid-impregnated samples revealed maximum flexural strength (63.4 MPa). In sum, the as-obtained ceramics would be used as ceramic cores for hollow blades in aircraft engines due to their high open porosity and moderate flexural strength.

Height shrinkage, health and mortality among older adults: Evidence from Indonesia

In this paper, we analyze the correlates of height shrinkage and the association of height shrinkage and late-life health among mid-aged and older adults from the Indonesian Family Life Survey. We first document the extent of height shrinkage based on measured height over 17 years. Height shrinkage is higher among older age groups, taller individuals, and women. Socioeconomic and initial health correlates of shrinkage are found to be different for men and women. Higher education, marital status, household consumption, urban birth and poor self-reported health in adulthood and childhood are found to be significant correlates for men. Ethnicity, working in the agricultural sector and availability of local health infrastructure are key correlates of height shrinkage for women. Height shrinkage of 1 cm is associated with a 0.02 s.d. decrease in cognition scores for Indonesian men and a 0.01 s.d. decrease for women, and 4% increase in index of mobility difficulties for both men and women. Extreme height loss, defined as height loss greater than 3 cm is associated with 8–10 percent lower lung function and grip strength among both men and women. Extreme height loss among Indonesian older women is also associated with a 7-percentage-point increase in the likelihood of death in the most recent wave. Our results emphasize the importance of taking into account age related height loss as a significant covariate for health and mortality of older adults, independent of baseline height and health.

Height Shrinkage, Health and Mortality Among Older Adults: Evidence from Indonesia

In this paper, we analyze the correlates of height shrinkage and the association of height shrinkage and late-life health among older adults aged over 50 from the Indonesian Family Life Survey. We first document the extent of height shrinkage based on measured height over 17 years. Height shrinkage is higher among older age groups, taller individuals, and women. Shrinkage is lower among men living in urban areas, and higher education is weakly associated with lower levels of height loss, but these associations are not found for women. Height shrinkage of 1 cm is associated with a 0.03 s.d. decrease in cognition scores for both older Indonesian men and women. Extreme height loss, defined as height loss greater than 3 cm is associated with 8 to 10 percent lower lung function and grip strength among both men and women. While height is not correlated with disability, extreme height loss is associated with a higher likelihood of disability by 8 percentage points. Extreme height loss among Indonesian older women is also associated with a 9 percentage points increase in the likelihood of death in the most recent wave. Our results emphasize the importance of taking into account age related height loss as a significant covariate for health and mortality of older adults, independent of baseline height.

3D gel printing of porous calcium silicate scaffold for bone tissue engineering

Potential porous calcium silicate (CaSiO3) scaffolds for bone tissue engineering were successfully prepared by 3D gel printing technology. The average particle size of CaSiO3 powder is about 5.119 μm. The CaSiO3 slurry prepared for printing had been exhibited shear-thinning properties, and the maximum solid loading of the slurry was 72 wt%. The green scaffolds were sintered at 1150 °C for 4 h after degreasing at 250 °C for 3 h, 420 °C for 9 h, and 660 °C for 3 h, respectively. The sintered scaffolds have well-distributed designed voids and microporous. The shrinkage in length, width, and height is 12.29 ± 0.20%, 12.43 ± 0.17%, 13.15 ± 0.19%, respectively. The porosity of the sintered scaffold is approximately 62%, and the compressive strength is about 16.52 MPa, which is equivalent to the strength of human cancellous bone.

3D gel-printing of hydroxyapatite scaffold for bone tissue engineering

Porous hydroxyapatite (HA) scaffolds for bone tissue engineering were successfully prepared using 3D gel-printing technology. The rheological properties of the HA ceramic slurry, the porosity and shrinkage of the scaffold, and the mechanical properties and degradability of the scaffold were studied. The influence of printing speed on the formation of the scaffold was also investigated. HA ceramic slurry with a solid volume fraction of 55 vol% was used to prepare the scaffolds with an interconnected pore structure that can provide a channel for the adhesion, proliferation, and substance transportation of bone cells. The sintered scaffold had a pore size of about 350 µm × 350 µm. The porosity, and shrinkage in height and width were 52.26%, 16.2 ± 0.2%, and 17.8 ± 0.23%, respectively. The maximum compressive strength and compressive modulus of the sintered scaffolds were 16.77 ± 0.38 and 492 ± 11 MPa, respectively. The weight loss rate of the scaffold was 10.38% after degradation in Tris-HCl solution for 5 wk.