Manufacturing and Evaluation of the Mechanical Response of Geopolymeric Mortars with Raw Materials from Khapia Hill in Puno (Peru)

Gene-mediated Restoration of Normal Myofiber Elasticity in Dystrophic Muscles

ObjectiveTo investigate the Young's modulus value of infraspinatus tendons using shear wave elastography (SWE) technique in normal adults, and to analyze the influence of gender, postures, exercise, and dominant side on Young's modulus of infraspinatus tendons.MethodsThis is a prospective cross‐sectional study. From January 2019 to July 2020, 14 healthy subjects were identified, including seven males and seven females aged between 24 to 34, with a mean age of 27.67 ± 3.08 years. The Young's modulus of their infraspinatus tendons was measured by two operators using SWE in neutral and maximum external rotation positions of both sides before exercise and the dominant side after exercise. The Young's modulus values in different sexes, different postures, before vs after exercise, and dominant vs non‐dominant side were statistically analyzed.ResultsAll 14 subjects completed the data collection process. The mean Young's modulus values of infraspinatus tendon for dominant sides in neutral position were 33.04 ± 3.01 kPa for males and 28.76 ± 3.09 kPa for females. And for non‐dominant sides in the neutral position, the values were 33.02 ± 2.38 kPa for males and 28.86 ± 2.47 kPa for females. In the maximum external rotation position, the values for dominant sides were 50.19 ± 4.86 kPa for males and 42.79 ± 4.44 kPa for females, and for non‐dominant sides were 50.95 ± 3.24 kPa for males and 42.42 ± 3.66 kPa for females. After exercise, the mean Young's modulus values of infraspinatus tendon for dominant sides in neutral position were 54.56 ± 3.76 kPa for males and 46.66 ± 5.99 kPa for females. And for the maximum external rotation position, the values were 59.13 ± 3.78 kPa for males and 54.49 ± 5.67 kPa for females. The Young's modulus of infraspinatus tendon in the neutral and maximum external rotation positions showed statistically significant differences in males and females, as well as before and after exercise (P < 0.05). However, the difference in Young's modulus between the dominant and non‐dominant sides was not statistically significant (P > 0.05). Intergroup reliability between both operators was excellent (ICC > 0.85).ConclusionThere are gender‐related differences and post‐exercise increase in Young's modulus, yet such a difference cannot be witnessed between the dominant and non‐dominant sides.

PURPOSEThis study inspects the effect of incorporating halloysite nanotubes (HNTs) into polymethyl methacrylate (PMMA) resin on its flexural strength, hardness, and Young's modulus.MATERIALS AND METHODSFour groups of acrylic resin powder were prepared. One group without HNTs was used as a control group and the other three groups contained 0.3, 0.6 and 0.9 wt% HNTs. For each one, flexural strength, Young's modulus and hardness values were measured. One-way ANOVA and Tukey's test were used for comparison (P<.05).RESULTS At lower concentration (0.3 wt%) of HNT, there was a significant increase of hardness values but no significant increase in both flexural strength and Young's modulus values of PMMA resin. In contrast, at higher concentration (0.6 and 0.9 wt%), there was a significant decrease in hardness values but no significant decrease in flexural strength and Young's modulus values compared to those of the control group.CONCLUSIONAddition of lower concentration of halloysite nanotubes to denture base materials could improve some of their mechanical properties. Improving the mechanical properties of acrylic resin base material could increase the patient satisfaction.

To compare the clinical effect between pricking-cupping therapy and acupuncture-cupping therapy on cervical spondylotic radiculopathy (CSR) with qi stagnation and blood stasis, and to evaluate the trapezius muscle objectively and quantitatively with ultrasonic shear wave elastography (SWE). A total of 70 patients with CSR of qi stagnation and blood stasis were randomly divided into a pricking-cupping group (35 cases) and an acupuncture-cupping group (35 cases). In both groups, Dazhui (GV 14), Jianjing (GB 21), C5-C7 Jiaji (EX-B 2), positive sensitive points, etc. were selected. In addition, the patients in the pricking-cupping group were treated with pricking-cupping therapy, seven-star needle was used to tap the acupoints and positive sensitive points, and cupping was added after slight bleeding. The patients in the acupuncture-cupping group were treated with conventional acupuncture and cupping. Both groups were treated once every other day, three times a week, for two consecutive weeks. The difference of Young's modulus value, pain visual analogue scale (VAS) score and neck disability index (NDI) score were observed before treatment, after the first treatment, after one-week treatment and after two-week treatment, and the efficacy was evaluated in the two groups. At each time point after treatment, the difference of Young's modulus value, VAS scores and NDI scores in the two groups were lower than those before treatment (P<0.001). Except for the NDI score after two-week treatment, all the indexes in the pricking-cupping group were lower than those in the acupuncture-cupping group (P<0.001). The total effective rate was 91.4% (32/35) in the pricking-cupping group, which was higher than 68.6% (24/35) in the acupuncture-cupping group (P<0.05). The pricking-cupping therapy could improve trapezius muscle elasticity, relieve pain and improve cervical function in patients of CSR with qi stagnation and blood stasis, which is more effective than acupuncture-cupping therapy.

Strength, porosity and life cycle analysis of geopolymer and hybrid cement mortars for sustainable construction

Objective. To determine in the experiment the changes in the elasticity of the liver parenchyma during its radiofrequency ablation at different distances from the electrode and their correspondence to the zones of irreversible thermal damage of the tissue. Materials and methods. The elasticity of the parenchyma of six samples of isolated porcine liver during radiofrequency ablation in automatic mode for 12 min with an initial applicator power of 50 W and its subsequent automatic increase by 10 W/min until critical impedance values were reached was evaluated by ultrasonic elastometry with the determination of the Young's modulus. The elasticity of the liver in kilopascals was determined before the start of radiofrequency ablation, during its implementation every minute for 12 minutes and 15, 30 and 60 minutes after the procedure in three zones located at a distance of 1.0, 1.8 and 3.0 cm from the applicator. Results. Before radiofrequency ablation, the elasticity of the liver parenchyma ranged from 4.1 to 9.3 kPa and averaged (6.64 ± 1.55) kPa. At the maximum power of the applicator – (109.67 ± 4.97) W – the transverse size of the hyperechogenic “cloud” at the 12th minute of the procedure was (18.0 ± 1.41) mm. The value of Young's modulus in the first zone of elastometry statistically significantly increased from the 1st minute of radiofrequency ablation and by the 11th minute reached the level of (46.38 ± 5.43) kPa and did not change significantly thereafter. In the second zone, a statistically significant increase in the value of Young's modulus to (44.22 ± 6.55) kPa was observed throughout the procedure, and after its termination it changed statistically insignificantly. In the third zone, changes in the value of Young's modulus occurred 3 minutes after the start of the procedure and continued until its completion, but its maximum value – (15.63 ± 1.57) kPa – exceeded the baseline level only about 2 times, and an hour after the completion of radiofrequency ablation, the value of Young's modulus decreased statistically significantly. Conclusions. The stiffness of the parenchyma of isolated porcine liver increases significantly during radiofrequency ablation under conditions of its sufficient duration, and depending on the distance to the electrode, these changes have different phase character. In loci corresponding to the zone of irreversible tissue necrosis, the initial slow approximately twofold increase in Young's modulus during the first 3 to 4 minutes is followed by a rapid exponential increase in the next 5 to 6 minutes and the formation of a plateau with 6 to 8 times the initial level, after which the index does not change significantly. To determine the edge of liver parenchyma ablation by elastometry, in addition to the absolute value of Young's modulus at the end of radiofrequency ablation and the multiplicity of its increase relative to the baseline value, such criteria as the three–phase nature of the increase in this indicator and the absence of its decrease within an hour after the procedure are equally important.

The diagnostic value of two-dimensional shear wave elastography in gestational diabetes mellitus

Viral hepatitis causes fibrosis in liver and may change liver's mechanical properties. To evaluate the impact of fibrosis on elastic properties of human liver and to investigate potential benefits of ultrasonic elasticity imaging, nineteen fresh human liver samples and one hepatic tumor (focal nodular hyperplasia) sample obtained during operations were studied. Simple ID estimates based on the cyclic compression-relaxation method were preformed. Young's modulus values were derived from the pre-determined strain (controlled by a step motor system) and the stress values (measured by an electronic balance). Each specimen subsequently received histological examination and a grade of liver fibrosis was scored from 0 to 5. Results show that the Young's modulus values were at the order of several hundreds to thousands Pascals. The Young's modulus generally increased with the fibrosis grade though some discrepancies existed at the middle grades of fibrosis (score 1-3). The correlation between the fibrosis score and the Young's modulus was significant (P<0.01) based on the statistical analysis using the Pearson correlation method.

The displacements of axially loaded single piles can be analyzed using a variety of techniques. One of the simplest is based on the theory of elasticity and, thus, is most useful for estimating movements in working range of loads. An advantage of this method is that it requires use of only two soil properties: Young's modulus and Poisson's ratio. Predictions are relatively insensitive to the selected values of Poisson's ratio. Values of Young's modulus are not usually obtained during a site investigation. In situ values in the free field may not be relevant for prediction of pile displacements because pile driving is likely to change the properties in critical regions right around the pile. Consequently, the most practical approach seems to be to find values of Young's modulus that cause predictions to match measurements and develop correlations with data from conventional field testing. Such analyses were performed using data from a number of pile load tests performed in California. The results are presented here. ABSTRACT: The displacements of axially loaded single piles can be analyzed using a variety of techniques. One of the simplest is based on the theory of elasticity and, thus, is most useful for estimating movements in working range of loads. An advantage of this method is that it requires use of only two soil properties: Young's modulus and Poisson's ratio. Predictions are relatively insensitive to the selected values of Poisson's ratio. Values of Young's modulus are not usually obtained during a site investigation. In situ values in the free field may not be relevant for prediction of pile displacements because pile driving is likely to change the properties in critical regions right around the pile. Consequently, the most practical approach seems to be to find values of Young's modulus that cause predictions to match measurements and develop correlations with data from conventional field testing. Such analyses were performed using data from a number of pile load tests performed in California. The results are presented here.

Elasticity, plasticity and fine structure of plant cell walls

Rapid fabrication of cross-linked silica aerogel by laser induced gelation

Spark plasma reaction sintering of ZrO 2–mullite composites from plasma spheroidized zircon/alumina powders

Recycled Non-Biodegradable polyethylene terephthalate waste as fine aggregate in fly ash geopolymer and cement mortars

Experimental Young's modulus values were obtained as a function of adsorbed moisture content for filter paper samples with no absorbed salt and with several different types of salt adsorbed on filter paper. The Young's modulus values were correlated with the room-temperature phosphorescence intensities and room-temperature phosphorescence lifetimes of several phosphors adsorbed on filter paper samples with the use of a theory for the Young's modulus of paper and solid-matrix phosphorescence quenching concepts. Phosphorescence intensity ratios changed much more dramatically than phosphorescence lifetime ratios, both with increasing moisture uptake on the filter paper and with decreasing modulus ratio of the filter paper samples. The changes in the phosphorescence parameters, due to the adsorption of moisture on filter paper, were caused primarily by alterations of the hydrogen-bonding network in the amorphous regions of filter paper.

PERFORMANCE PROPERTIES OF SALTSTONE PRODUCED USING SWPF SIMULANTS