Low Intensity Resistance Exercise Training with Blood Flow Restriction: Insight into Cardiovascular Function, and Skeletal Muscle Hypertrophy in Humans

Park, Song-Young,Kwak, Yi Sub,Harveson, Andrew,Weavil, Joshua C.,Seo, Kook E. The Korean Society of Pharmacology 2015 The Korean Journal of Physiology & Pharmacology Vol.19 No.3

Attenuated functional exercise capacity in elderly and diseased populations is a common problem, and stems primarily from physical inactivity. Decreased function and exercise capacity can be restored by maintaining muscular strength and mass, which are key factors in an independent and healthy life. Resistance exercise has been used to prevent muscle loss and improve muscular strength and mass. However, the intensities necessary for traditional resistance training to increase muscular strength and mass may be contraindicated for some at risk populations, such as diseased populations and the elderly. Therefore, an alternative exercise modality is required. Recently, blood flow restriction (BFR) with low intensity resistance exercise (LIRE) has been used for such special populations to improve their function and exercise capacity. Although BFR+LIRE has been intensively studied for a decade, a comprehensive review detailing the effects of BFR+LIRE on both skeletal muscle and vascular function is not available. Therefore, the purpose of this review is to discuss previous studies documenting the effects of BFR+LIRE on hormonal and transcriptional factors in muscle hypertrophy and vascular function, including changes in hemodynamics, and endothelial function.

95 kW Fuel Cell-Based Test of a Novel Self-Pressurized Liquid Hydrogen Storage System

Rahmadio Catur Putra,Song Soo Young(송수용),Joshua Kim Schimpf,Seo Young Kim(김서영) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2021 No.6

Symptomatic Construct Failure after Metastatic Spine Tumor Surgery

Kumar Naresh,Patel Ravish,Tan Jiong Hao,Song Joshua,Pandita Naveen,Hey Dennis Hwee Weng,Lau Leok Lim,Liu Gabriel Ka-Po,Thambiah Joseph,Wong Hee-Kit 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.4

Study Design: Retrospective cohort study.Purpose: To evaluate the incidence and presentation of symptomatic failures (SFs) after metastatic spine tumor surgery (MSTS). To identify the associated risk factors. To categorize SFs based on the management in these patients.Overview of Literature: Few studies have reported on the incidence (1.9%–16%) and risk factors of SF after MSTS. It is unclear whether all SFs, occurring in MSTS-patients, result in revision surgery.Methods: We conducted a retrospective analysis on 288 patients (246 for final analysis) who underwent MSTS between 2005–2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological SF were defined as presentation before and after 3 months from index surgery, respectively. Univariate and multivariate models of competing risk regression analysis were designed to determine the risk factors for SF with death as a competing event.Results: We observed 14 SFs (5.7%) in 246 patients; 10 (4.1%) underwent revision surgery. Median survival was 13.4 months. The mean age was 58.8 years (range, 21–87 years); 48.4% were women. The median time to failure was 5 months (range, 1–60 months). Patients with SF were categorized into three groups: (1) SF when the primary implant was revised (n=5, 35.7%); (2) peri-construct progression of disease requiring extension (n=5, 35.7%); and (3) SFs that did not warrant revision (n=4, 28.5%). Four patients (28.5%) presented with early failure. SF commonly occurred at the implant-bone interface (9/14) and all patients had a spinal instability neoplastic score (SINS) >7. Thirteen patients (92.8%) who developed failure had fixation spanning junctional regions. Multivariate competing risk regression showed that preoperative Eastern Cooperative Oncology Group score was a significant risk factor for implant failure (adjusted sub-hazard ratio, 7.0; 95% confidence interval, 1.63–30.07; p<0.0009).Conclusions: The incidence of SF (5.7%) was low in patients undergoing MSTS although these patients did not undergo spinal fusion. Preoperative ambulators involved a 7 times higher risk of failure than non-ambulators. Preoperative SINS >7 and fixations spanning junctional regions were associated with SF. Majority of construct failures occurred at the implant-bone interface.

Downregulation of exocyst Sec10 accelerates kidney tubule cell recovery through enhanced cell migration

Noh, Mi Ra,Jang, Hee-Seong,Song, Dae-Kyu,Lee, Seong-Ryong,Lipschutz, Joshua H.,Park, Kwon Moo,Kim, Jee In Elsevier 2018 Biochemical and biophysical research communication Vol. No.

<P><B>Abstract</B></P> <P>Migration of surviving kidney tubule cells after sub-lethal injury, for example ischemia/reperfusion (I/R), plays a critical role in recovery. Exocytosis is known to be involved in cell migration, and a key component in exocytosis is the highly-conserved eight-protein exocyst complex. We investigated the expression of a central exocyst complex member, Sec10, in kidneys following I/R injury, as well as the role of Sec10 in wound healing following scratch injury of cultured Madin-Darby canine kidney (MDCK) cells. Sec10 overexpression and knockdown (KD) in MDCK cells were used to investigate the speed of wound healing and the mechanisms underlying recovery. In mice, Sec10 decreased after I/R injury, and increased during the recovery period. In cell culture, Sec10 OE inhibited ruffle formation and wound healing, while Sec10 KD accelerated it. Sec10 OE cells had higher amounts of diacylglycerol kinase (DGK) gamma at the leading edge than did control cells. A DGK inhibitor reversed the inhibition of wound healing and ruffle formation in Sec10 OE cells. Conclusively, downregulation of Sec10 following I/R injury appears to accelerate recovery of kidney tubule cells through activated ruffle formation and enhanced cell migration.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Exocyst Sec10 decreases by I/R injury and restores with functional recovery. </LI> <LI> Sec10 inversely regulates kidney tubule cell wound healing after scratch injury. </LI> <LI> Sec10 inversely regulates ruffle formation at the leading edge during recovery. </LI> <LI> Upregulation of Sec10 increases DGKγ expression at the leading edge during recovery. </LI> <LI> DGK inhibitor reversed Sec10-mediated ruffle formation and wound healing defect. </LI> </UL> </P>

Effects of impact conditions on the electrical and mechanical properties of supersonic cold sprayed Cu–Ni electrodes

Lee, Jong-Gun,Lee, Jong-Hyuk,An, Seongpil,Yoon, Joshua Yeosong,Choi, Jae-Wook,Kang, Min Gu,Lee, Jeong In,Song, Hee-eun,Al-Deyab, Salem S.,James, Scott C.,Kang, Yoonmook,Kim, Donghwan,Yoon, Sam S.,Lee, Elsevier 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.695 No.-

<P><B>Abstract</B></P> <P>Supersonic cold sprayed Cu and Ni particles were deposited on Si wafers for potential use as solar-cell front electrodes. Line-printed Ni–Cu electrodes were successfully fabricated with thicknesses between 30 and 50 μm. Choice of carrier gas (nitrogen and air) and effects of particle size and impact velocity on the electrical and mechanical properties of these Ni–Cu electrodes were quantified. The carrier gas had no discernable effect on electrode properties while increased particle sizes slightly decreased electrode specific resistivities. Impact velocity had the most pronounced influence on electrode electrical properties. Both the contact and specific resistivities decreased nearly linearly with increasing impact velocity. Adhesion strength was measured with a STAB-TEST instrument and found sufficient for all measured electrodes. The electrodes were further characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and auger electron spectroscopy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Supersonically sprayed Cu and Ni particles were deposited on Si wafers for potential use as solar-cell front electrodes. </LI> <LI> Line-printed Ni–Cu electrodes were successfully fabricated with thicknesses between 30 and 50 μm. </LI> <LI> Effects of impact conditions on the electrical and mechanical properties of these Ni–Cu electrodes were quantified. </LI> <LI> Both the contact and specific resistivities decreased nearly linearly with increasing impact velocity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>