Fabrication of Pressure Conductive Silicone Rubber Socket Device by Shape-Controlled Nickel Powders Produced by High-Energy Ball Milling.

The pressure conductive silicone rubber socket (PCR) is one of the promising test socket devices in high-speed testing environments. In this study, we report highly dense PCR device channels comprised of high aspect-ratio flake-shaped Ni powders. The shape-controlled Ni powders are prepared by the high-energy milling process. The scanning electron microscopy (SEM) and particle size analyzer (PSA) results of the synthesized powder samples showed well-defined flake type Ni powder morphology, and the powder sizes are distributed in the range of ~24-49 µm. The cross-sectional SEM study of the fabricated PCR revealed that the channels consisting of flake Ni powder are uniformly, densely distributed, and connected as face-to-face contact. The resistance of the PCR channels comprised of flake-shaped Ni powders showed ~23% lower resistance values than the spherical-shaped Ni powders-based channels, which could be due to the face-to-face contact of the powders in the channels. The magnetic properties study for the flake-type Ni powder showed a high remanence (~2.2 emu/g) and coercivity (~5.24 mT), owing to the shape anisotropy factor. Finally, the fabricated highly dense and conductive channels of the silicone rubber socket device by shape-controlled Ni powder could be a potential test socket device.

Interactions between red and processed meat consumption and APOA5 gene variants associated with the incidence of metabolic syndrome in Korean adults.

BACKGROUND: Metabolic syndrome (MetS) is characterized by the coexistence of disorders such as diabetes, hypertension, hyperlipidemia, and obesity and is affected by genetic factors. Previous genome-wide association studies (GWAS) suggested that APOA5 gene variants were significantly associated with MetS and its components. Dietary factors such as red and processed meat consumption can cause chronic diseases, including hypertension, diabetes, and vascular depression. The aim of this study was to investigate the modulation of the incidence of MetS by the interaction between APOA5 rs662799 polymorphism and red and processed meat consumption. METHODS: In this prospective cohort study, 3266 participants were collected from the Korea Association REsource (KARE) cohort of the Korean Genome and Epidemiology Study (KoGES) from 2001 to 2016. APOA5 rs662799 polymorphism was extracted by GWAS using the Korean Chip. Red and processed meat consumption data were assessed using a semi-quantitative food frequency questionnaire. RESULTS: The incidence of MetS in carriers of the minor G allele of rs662799 (AG + GG) and the third tertile of red and processed meat consumption (serving/day) was higher than those with the major allele of rs662799 (AA) and the first tertile of red and processed meat consumption (HR 1.70, 95% CI 1.30-2.22, p interaction = 0.002). CONCLUSIONS: An association between the presence of the minor alleles of rs662799 and high red and processed meat consumption and the incidence of MetS was observed in Korean adults.

Dietary Protein and Fat Intake Affects Diabetes Risk with CDKAL1 Genetic Variants in Korean Adults.

Cyclin-dependent kinase 5 regulatory subunit-associated protein 1-like 1 (CDKAL1) is one of the strongest diabetes loci identified to date; evidence suggests that it plays an important role in insulin secretion. Dietary factors that affect insulin demand might enhance the risk of diabetes associated with CDKAL1 variants. Our aim was to examine the interactions between dietary protein and fat intake and CDKAL1 genetic variants in relation to the risk of diabetes in Korean adults. Single nucleotide polymorphisms (SNPs) were selected with a genome-wide association study (GWAS) for diabetes after adjustment for age, gender, and examination site. Using data from the Health Examinees (HEXA) Study of the Korean Genome and Epidemiology Study (KoGES), 3988 middle-aged Korean adults between 40-76 years of age (2034 men and 1954 women) were included in the study. Finally, rs7756992 located within the CDKAL1 gene region was selected from GWAS (p-value < 5 × 10-8). Multivariable logistic regression models were used to evaluate the interactions between genotypes and dietary protein and fat intake in relation to diabetes risk after adjustment for age, gender, BMI, waist circumference, physical activity, smoking status, drinking habits, and examination site. Significant interactions between CDKAL1 rs7756992 and dietary protein and fat intake for the risk of diabetes were observed in men (p-value < 0.05). In women, significant interactions between dietary protein and fat intake and CDKAL1 variants (rs7756992) were associated with increased risk of diabetes (p-value < 0.05). Dietary protein and fat intake interacted differently with CDKAL1 variants in relation to the risk of diabetes in Korean adults of both genders. These findings indicate that CDKAL1 variants play a significant role in diabetes and that dietary protein and fat intake could affect these associations.

Different weight bearing push-up plus exercises with and without isometric horizontal abduction in subjects with scapular winging: A randomized trial.

The aim of the present study was to determine whether the application of isometric horizontal abduction (IHA) differentially affected two weight-bearing push-up plus exercises by examining activation of the scapulothoracic muscles in subjects with scapular winging. Fifteen male subjects performed standard push-up plus (SPP) and wall push-up plus (WPP), with and without IHA. Two-way analyses of variance using two within-subject factors were used to determine the statistical significance of observed differences in upper trapezius (UT), pectoralis major (PM), and serratus anterior (SA) muscle activities and UT/SA and PM/SA muscle activity ratios. UT and SA muscle activities were greater during SPP than WPP. PM muscle activity was lower with IHA application. The UT/SA and PM/SA muscle activity ratios were lower during SPP than WPP. The PM/SA muscle activity ratio was lower with IHA application. The results suggest that IHA application using a Thera-Band can effectively reduce PM muscle activity during SPP and WPP exercises. Moreover, the SPP exercise can be used to increase UT and SA muscle activity and reduce the UT/SA and PM/SA muscle activity ratios in subjects with scapular winging.

Reliability of levator scapulae index in subjects with and without scapular downward rotation syndrome.

OBJECTIVES: The objective of this study was to introduce levator scapulae (LS) measurement using a caliper and the levator scapulae index (LSI) and to investigate intra- and interrater reliability of the LSI in subjects with and without scapular downward rotation syndrome (SDRS). DESIGN: Two raters measured LS length twice in 38 subjects (19 with SDRS and 19 without SDRS). MAIN OUTCOME MEASURES: For reliability testing, intraclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimal detectable change (MDC) were calculated. RESULTS: Intrarater reliability analysis resulted with ICCs ranging from 0.94 to 0.98 in subjects with SDRS and 0.96 to 0.98 in subjects without SDRS. These results represented that intrarater reliability in both groups were excellent for measuring LS length with the LSI. Interrater reliability was good (ICC: 0.82) in subjects with SDRS; however, interrater reliability was moderate (ICC: 0.75) in subjects without SDRS. Additionally, SEM and MDC were 0.13% and 0.36% in subjects with SDRS and 0.35% and 0.97% in subjects without SDRS. In subjects with SDRS, low dispersion of the measurement errors and MDC were shown. CONCLUSIONS: This study suggested that the LSI is a reliable method to measure LS length and is more reliable for subjects with SDRS.

Various shrug exercises can change scapular kinematics and scapular rotator muscle activities in subjects with scapular downward rotation syndrome.

Scapular dyskinesis, characterized by scapular downward rotation syndrome (SDRS) affects scapula-humeral rhythm and results in shoulder dysfunction. Previous study has led to the recommendation of standard shrug exercise to contend with SDRS and strengthen the upper trapezius (UT) muscle. However, few researchers have examined which shrug exercise is most effective. The aim of this research was to compare scapular kinematic changes and scapular rotator muscles activity across three different shrug exercises in SDRS. The amounts of scapular downward rotation were measured by a caliper and the scapular upward rotation angle was measured using two digital inclinometers. Surface electromyography was used to measure EMG amplitude from the UT, lower trapezius (LT), serratus anterior (SA), and levator scapula (LS). Seventeen subjects with SDRS were recruited for this study. The subjects performed three shrug exercises with 30° shoulder abduction (preferred shrug, frontal shrug, and stabilization shrug). The stabilization shrug showed a significantly greater scapular upward rotation angle compared with the preferred shrug (P=0.004) and frontal shrug (P=0.006). The UT activity was significantly greater in the frontal shrug than in the preferred shrug (P=0.002). The UT/LS muscle activity ratio was also significantly greater in the frontal shrug than in the preferred shrug (P=0.004). The stabilization shrug should be preferred to enhance the upward rotation angle. In addition, the frontal shrug can be used as an effective method to increase UT activity and to decrease LS activity in SDRS.

Comparison of scapular posterior tilting exercise alone and scapular posterior tilting exercise after pectoralis minor stretching on scapular alignment and scapular upward rotators activity in subjects with short pectoralis minor.

OBJECTIVES: To compare scapular posterior tilting exercise alone and scapular posterior tilting exercise after pectoralis minor (PM) stretching on the PM index (PMI), scapular anterior tilting index, scapular upward rotation angle, and scapular upward rotators' activity in subjects with a short PM. PARTICIPANTS: Fifteen subjects with a short PM participated in this study. MAIN OUTCOME MEASURES: The PMI, scapular anterior tilting index, and scapular upward rotation angle were measured after scapular posterior tilting exercise alone and scapular posterior tilting exercise after PM stretches. Scapular upward rotators' activities were collected during scapular posterior tilting exercise alone and scapular posterior tilting exercise after PM stretches. RESULTS: The PMI and scapular upward rotation angle, as well as the activity of the upper trapezius, lower trapezius, and serratus anterior muscles, were significantly greater for scapular posterior tilting exercise after PM stretching and the scapular anterior tilting index was significantly lower for scapular posterior tilting exercise after PM stretching than the scapular posterior tilting exercise alone. CONCLUSIONS: Scapular posterior tilting exercise after PM stretching in subjects with a short PM could be an effective method of modifying scapular alignment and scapular upward rotator activity.

Shrug exercises combined with shoulder abduction improve scapular upward rotator activity and scapular alignment in subjects with scapular downward rotation impairment.

The aim of this research was to investigate which shoulder abduction angle (30°, 90°, 150°) during shrug exercise is superior for (1) activating the scapular upward rotators and (2) improving scapular and clavicular position in subjects with scapular downward rotation impairment. Twenty subjects performed shrug exercises at three different shoulder abduction angles (30°, 90°, 150°) which were obtained and maintained actively. Surface EMG data were collected from the levator scapulae (LS), upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) during shrug exercises. Scapular downward rotation index (SDRI) and clavicular tilt angle (CTA) were measured immediately after each shrug exercise. Oneway repeated-measures analysis of variance was used to determine the significance. UT muscle activity was greater at 90° and 150° than at 30° of shoulder abduction. UT/LS muscle activity ratio was greater at 90° than at 30°. LT and LT/LS increased as shoulder abduction angle increased. SA was greater at 150° than at 30° or 90°. SA/LS was greater at 150° than at 30°. SDRI was lower at 90° and 150° than at 30°. CTA was greater at 90° and 150° than at 30°. In conclusion, shrug exercises at 90° or 150° of shoulder abduction angle may be advocated to activate scapular upward rotators, decrease SDRI, and increase CTA in patients with scapular downward rotation impairment.

The effect of scapular posterior tilt exercise, pectoralis minor stretching, and shoulder brace on scapular alignment and muscles activity in subjects with round-shoulder posture.

BACKGROUND: There are various methods for rehabilitating round-shoulder posture (RSP), including strengthening exercises, stretching, and using a shoulder brace or taping to correct the altered posture. However, no study has determined which intervention is the most effective of the three methods to decrease RSP (intervention #1: scapular posterior tilting exercise alone [hereafter, SPT], intervention #2: the scapular posterior tilting exercise after PM stretching [PM stretch+SPT], and intervention #3: the scapular posterior tilting exercise with use of a shoulder brace [SPT+brace]). OBJECTIVES: The purpose of this study was to compare the SPT, PM stretch+SPT, and SPT+brace on RSP, PM index (PMI), and lower trapezius (LT) and serratus anterior (SA) activity in subjects with RSP. METHODS: In total, fifteen young men with RSP, participated in the study (21.46 ± 2.30 years old). RSP was confirmed using a caliper measure. Surface electromyography (SEMG) data for LT and SA activity were collected during the three interventions, and the SEMG data are expressed as a percentage of the maximal voluntary isometric contraction (%MVIC). RESULTS: RSP was significantly less in the PM stretch+SPT and SPT+brace than in the SPT (P<0.05). PMI was significantly greater in the PM stretch+SPT and SPT+brace than in the SPT (P<0.05). LT activity was significantly greater in the PM stretch+SPT than in the SPT or SPT+brace in subjects with RSP (P<0.05). CONCLUSIONS: The PM stretching exercise and application of a shoulder brace may help correct RSP and restore the length of the PM. The posterior tilting exercise after PM stretching was the most effective method for eliciting greater LT muscle activation among the interventions tested.

Isometric hip abduction using a Thera-Band alters gluteus maximus muscle activity and the anterior pelvic tilt angle during bridging exercise.

The purpose of this study was to investigate the effects of bridging with isometric hip abduction (IHA) using the Thera-Band on gluteus maximus (GM), hamstring (HAM), and erector spinae (ES) muscle activity; GM/HAM and GM/ES ratios; and the anterior pelvic tilt angle in healthy subjects. Twenty-one subjects participated in this study. Surface EMG was used to collect EMG data of GM, HAM, and ES muscle activities, and Image J software was used to measure anterior pelvic tilt angle. A paired t-test was used to compare GM, HAM, and ES muscle activity; the GM/HAM and GM/ES ratios; and the anterior pelvic tilt angle with and without IHA during the bridging exercise. GM muscle activity increased significantly and the anterior pelvic tilt angle decreased significantly during bridging with IHA using the Thera-Band (p < 0.05). However, there were no significant differences in the activity of the HAM and ES and the GM/HAM and GM/ES ratios between bridging with and without IHA (p > 0.05). The results of this study suggest that bridging with IHA using the Thera-Band can be implemented as an effective method to facilitate GM muscle activity and reduce the anterior pelvic tilt angle.

Trunk muscle activation during different quadruped stabilization exercises in individuals with chronic low back pain.

BACKGROUND AND PURPOSE: The aim of this study was to compare the trunk muscle activities and the local/global activity ratios of the abdominal, back and trunk muscles during stabilization exercises such as one arm raise (AR), one leg raise (LR), and opposing arm/leg raise (ALR) in patients with chronic low back pain (LBP). METHOD: Ten individuals with chronic LBP (five men and five women) participated in this study. The external oblique abdominis, internal oblique abdominis, multifidus, thoracic part of the lumbar iliocostalis and the local/global activity ratio were assessed, while quadruped stabilization exercises were performed (AR, LR, and ALR); each exercise was carried out three times. RESULT: One-way repeated ANOVA was used to measure the differences in the trunk muscle activity and the local/global activity ratio. Post hoc analyses were performed (α = 0.05/3 = 0.017). In the right internal oblique, muscle activity during LR was significantly greater than that during AR. In the bilateral multifidus and lumbar iliocostalis, each ALR muscle activity was significantly greater than those of AR and LR. In addition, the local/global activity ratios of the back and trunk muscle in LR and ALR were significantly greater compared with AR. CONCLUSIONS: LR should be recommended over AR for individuals with chronic LBP. Moreover, the application of ALR should be approached carefully on the basis of progress and ability to stabilize the spine in this patient population.

Different hip rotations influence hip abductor muscles activity during isometric side-lying hip abduction in subjects with gluteus medius weakness.

The purpose of this study was to establish the effects of different hip rotations during isometric side-lying hip abduction (SHA) in subjects with gluteus medius (Gmed) weakness by investigating the electromyographic (EMG) amplitude of the Gmed, tensor fasciae latae (TFL) activity, and gluteus maximus (Gmax), and the activity ratio of the Gmed/TFL, Gmax/TFL, and Gmed/Gmax. Nineteen subjects with Gmed weakness were recruited for this study. Subjects performed three isometric hip abductions: frontal SHA with neutral hips (SHA-N), frontal SHA with hip medial rotation (SHA-MR), and frontal SHA with hip lateral rotation (SHA-LR). Surface EMG amplitude was measured to collect the EMG data from the Gmed, TFL, and Gmax. A one-way repeated-measures analysis of variance was used to determine the statistical significance of the Gmed, TFL, and Gmax EMG activity and the Gmed/TFL, Gmax/TFL, and Gmed/Gmax EMG activity ratios. Gmed EMG activity was significantly greater in SHA-MR than in SHA-N. TFL EMG activity was significantly greater in SHA-LR than in SHA-N. The Gmed/TFL and Gmed/Gmax EMG activity ratios were also significantly greater in SHA-MR than in SHA-N or SHA-LR. The results of this study suggest that SHA-MR can be used as an effective method to increase Gmed activation and to decrease TFL activity during SHA exercises.

The use of chitosan as a condensing agent to enhance emulsion-mediated gene transfer.

Previously we have formulated a new cationic emulsion, composed of 3beta [N-(N',N'-dimethylaminoethane) carbamoyl] cholesterol and dioleoylphosphatidyl ethanolamine, castor oil and Tween 80, and it efficiently delivered plasmid DNA into various cancer cells with low toxicity. Chitosan is a natural cationic polysaccharide and is able to form polyelectrolyte complexes with DNA, in which the DNA is condensed and protected against nuclease degradation. Based on these facts, chitosan was used as a condensing agent to enhance the transfection efficiency of cationic emulsion-mediated gene delivery vehicle. The particle size, zeta potential and transmission electron micrographs of DNA/emulsion complexes were observed before and after condensation by chitosan. In vitro transfection efficiency of naked or precondensed DNA/emulsion (pcDNA/E) complexes was investigated in human hepatoma cells (HepG2) using flow cytometer, confocal microscope and western blot. In addition, in vivo gene transfer was also evaluated as GFP mRNA expression by reverse transcriptase-polymerase chain reaction. The size of transfection complexes was reduced after the condensation of DNA by chitosan. Moreover, when the pcDNA/E complexes were administered into the mice, the GFP mRNA expression was prolonged in liver and lung until day 6. These results suggest that the use of chitosan enhance the in vitro transfection efficiency and extend in vivo gene transfer.

Low toxicity of cationic lipid-based emulsion for gene transfer.

Cationic liposome has been studied as one of the most promising non-viral gene delivery systems. However, it has major drawbacks such as the formation of large aggregates at higher concentrations and the instability in the serum due to cationic lipid. As an alternative gene delivery system, cationic emulsion was formulated and transfection efficiency was evaluated in vitro and in vivo, in comparison with cationic liposome. Cationic emulsion was prepared with varying compositions of 3 beta [N-(N',N'-dimethylaminoethane) carbamoyl] cholesterol (DC-Chol), dioleoylphosphatidyl ethanolamine (DOPE), caster oil and Tween 80. Cationic liposome was prepared with DC-Chol and DOPE. The particle size of all the DNA/lipid complexes varied from 150 to 230 nm. The in vitro transfection efficiency of plasmid DNA was assessed by the expression of green fluorescent protein as a reporter. Of various formulations, cationic emulsion E2 (DC-Chol/DOPE/Castor Oil/Tween 80 = 0.3:0.3:0.3:0.15) and cationic liposome L3 (DC-Chol/DOPE = 0.6:0.3) showed improved transfection. DNA/E2 complexes exhibited higher transfection efficiencies (17.39+/-0.58%) in comparison with DNA/L3 complexes (11.47+/-0.59%). DNA/E2 complexes also showed a better physical stability and a stronger serum resistance than DNA/L3 complexes. Moreover, the cytotoxicity of DNA/E2 complexes was comparable to that of DNA/L3 complexes. When DNA/lipid complexes were intravenously administered, DNA/E2 complexes showed a prolonged circulation in blood and mRNA expression in various tissues compared with DNA/L3 complexes. These results suggest that cationic emulsion E2 could be a potential gene delivery system in clinical approaches because of enhanced in vivo gene transfer with low toxicity.