The Effects of Progressive Resistance Exercise on Recovery Rate of Bone and Muscle in a Rodent Model of Hindlimb Suspension

Purpose: This study aimed to examine the exercise-mediated musculoskeletal recovery following hindlimb suspension (HS) in order to identify whether bone modeling and muscle hypertrophy would eventuate in a synchronized manner during recovery stage.Methods: To identify whether 2-week HS would be sufficient to induce a significant reduction of physiological indices in both tibia and adjacent hindlimb muscles, a total of 20 rats was randomized into 2-week HS (n = 10) and age-matched control group (n = 10, CON). Another batch of rats were randomly assigned to three different groups to identify recovery intervention effects following suspension: (1) 2-week HS followed by 4-week spontaneous reloading recovery (HRE, n = 7). (2) 2-week HS followed by 4-week progressive resistance ladder climbing exercise (HEX, n = 7). (3) Age-matched control (CON, n = 7). DXA, micro-CT, and 18F-sodium fluoride (NaF) imaging, and EIA analysis were utilized to measure tibia bone indices. Hindlimb muscle wet weight and grip strength were measured to evaluate muscle mass and strength, respectively.Results: In study 1, bone quality values [bone volume/total volume (BV/TV): -27%, areal bone mineral density (aBMD): -23%, mineral contents: -7.9%, mineral density: –4.1%, and bone density: -38.9%] and skeletal muscle weight (soleus: -46.8%, gastrocnemius: -19.6%, plantaris: -20.8%, TA: -22.8%, and EDL: -9.9%) were significantly lower in HS group compared to CON group. In study 2, micro-CT and DXA-based bone morphology (bone density, BT/TV, and aBMD) were fully recovered in HRE or HEX group. However, suspension-induced dysregulation of bone mineral metabolism was returned to age-matched control group in only HEX group, but not in HRE group. A greater level of biomarkers of bone formation (P1NF) and resorption (CTX-1) was observed in only HRE group compared to CON. The hindlimb skeletal muscle mass was significantly lower in both HRE and HEX groups compared to CON group. Hindlimb grip strength was the greatest in HEX group, followed by CON and HRE groups.Conclusion: Following HS, progressive resistance exercise promotes recovery rates of bone and skeletal muscle strength without a significant increase in muscular mass, suggesting that exercise-induced reacquisition of bone and muscle strength is independent of muscle hypertrophy during early recovery stage

Barrier protection via Toll-like receptor 2 signaling in porcine intestinal epithelial cells damaged by deoxynivalnol

Additional file 2. IPEC-J2 cells pretreated with TLR2 ligand maintained the expression of MCP-1, GM-CSF and TLR2 against DON exposure. IPEC-J2 cells pretreated with or without TLR2 ligand for 24 h were exposed to DON. (A) The bar graph showed the mRNA levels of porcine mcp-1, gm-csf measured using real time-PCR at 1 and 6 h after DON exposure (n = 3). (B) The mRNA levels of porcine tlr2 were measured using real-time quantitative PCR analysis at 6 h. NT represents no treatment. Expression of each mRNA was presented relative to the expression of housekeeping gene, gapdh (n = 3). *P < 0.05; **P < 0.01; ***P < 0.001, determined by one-way ANOVA with Tukey’s posttest

Strongly adhesive dry transfer technique for van der Waals heterostructure

That one can stack van der Waals materials with atomically sharp interfaces has provided a new material platform of constructing heterostructures. The technical challenge of mechanical stacking is picking up the exfoliated atomically thin materials after mechanical exfoliation without chemical and mechanical degradation. Chemically inert hexagonal boron nitride (hBN) has been widely used for encapsulating and picking up vdW materials. However, due to the relatively weak adhesion of hBN, assembling vdW heterostructures based on hBN has been limited. We report a new dry transfer technique. We used two vdW semiconductors (ZnPS3 and CrPS4) to pick up and encapsulate layers for vdW heterostructures, which otherwise are known to be hard to fabricate. By combining with optimized polycaprolactone (PCL) providing strong adhesion, we demonstrated various vertical heterostructure devices, including quasi-2D superconducting NbSe2 Josephson junctions with atomically clean interface. The versatility of the PCL-based vdW stacking method provides a new route for assembling complex 2D vdW materials without interfacial degradation.Comment: Accepted for publication in 2D Material

Organosilicate Spin-on Glasses II. Effect of Physical Modification on Mechanical Properties

Porous copolymer films were synthesized from a methylsilsequioxane:1,2-bis(trimethoxysilyl)ethane (MSSQ:BTMSE) matrix and either an aromatic-core or aliphatic-core porogen at 10, 20, or 30 wt % porogen loading. Films were characterized using scanning electron microscopy (SEM), IR spectroscopy, and ellipsometry. Depth-sensing indentation experiments were performed to measure apparent film modulus, E, and hardness, H. Indentation load-displacement traces and SEM images were used to determine the threshold load for cracking, Pc. The aliphatic-core porogen produced a greater porosity film than the aromatic-core porogen for 10 wt % loading and smaller porosity films for 20 and 30 wt % loadings. IR spectra, normalized for film thickness and density, indicated decreased O-Si-O networking in porous MSSQ:BTMSE films. The combination of increased porosity and decreased O-Si-O networking led to a decreased apparent E and H relative to the unmodified MSSQ:BTMSE film. However, low-porosity (approximately 7%), aliphatic-porogen MSSQ:BTMSE films are optimized relative to unmodified MSSQ with smaller dielectric constant and greater E and H.This work is supported by the Korean Collaborative Project for Excellence in Basic System IC Technology (System IC 2010: 98- B4-C0-00-01-00-02). Financial support from the Ministry of Science and Technology (MOST) and the Korean Ministry of Education through the National Research Laboratory Fund and the Brain Korea 21 Program, respectively, is also greatly acknowledged

A new membrane performance index using flow-field flow fractionation (fl-FFF)

A new application of flow-field flow fractionation (fl-FFF) method was developed to quantify the interfacial interactions. The fl-FFF method was designed so as to characterize a new membrane performance index (MPI-FFF), which represents not only fouling resistibility of a membrane for a specific foulant, but also the removal capability for the foulant. Three commercial ultrafiltration (UF) and nanofiltration (NF) membranes and two foulants including organic and colloidal materials, were tested to verify MPI-FFF in lab-scale membrane fouling tests. Higher values of MPI-FFF mean better performance of membranes fora specific foulant in terms of rejection and fouling resistibility. According to the fouling tests, combinations of foulant and membrane with higher MPI-FFF values showed lower fouling and higher rejection characteristics, which means the MPI-FFF is a useful parameter to account for membrane performance. In addition. MPI-FFF values can be easily and quickly obtained for membranes and the foulants in the feed water tor the selection of membrane with high performanceclose1

3,3′-Bicarbazole-Based Host Molecules for Solution-Processed Phosphorescent OLEDs

Solution-processed organic light-emitting diodes (OLEDs) are attractive due to their low-cost, large area displays, and lighting features. Small molecules as well as polymers can be used as host materials within the solution-processed emitting layer. Herein, we report two 3,3′-bicarbazole-based host small molecules, which possess a structural isomer relationship. 9,9′-Di-4-n-butylphenyl-9H,9′H-3,3′-bicarbazole (BCz-nBuPh) and 9,9′-di-4-t-butylphenyl-9H,9′H-3,3′-bicarbazole (BCz-tBuPh) exhibited similar optical properties within solutions but different photoluminescence within films. A solution-processed green phosphorescent OLED with the BCz-tBuPh host exhibited a high maximum current efficiency and power efficiency of 43.1 cd/A and 40.0 lm/W, respectively, compared to the device with the BCz-nBuPh host

Continuous Task Transition Approach for Robot Controller based on Hierarchical Quadratic Programming

International audienceThe robots with high Degrees of Freedom (DoF) such as humanoids and mobile manipulators are expected to perform multiple tasks simultaneously. Hierarchical Quadratic Programming (HQP) can effectively compute a solution for strictly prioritized tasks. However, the continuity of control input is not guaranteed when the priorities of the tasks are modified during operation. This paper proposes a continuous task transition method for HQP based controller to insert, remove, and swap arbitrary tasks without discontinuity. Smooth task transition is assured because our approach uses activation parameters of the new and existing tasks without modifying control structure. The proposed approach is applied to various task transition scenarios including joint limit, singularity, and obstacle avoidance to guarantee the stable execution of the robot. The proposed control scheme was implemented on a 7-DoF robotic arm, and its performance was demonstrated by the continuity of control input during various task transition scenarios