Taekwondo Training Has Long-term Beneficial Effects on Bone Mineral Density and Physical Fitness in Middle-Aged Men

( Jennifer Ann Clarke ),( Hyun-chul Jung ),( Hyo-jung Kang ),( Myong-won Seo ),( Jong-kook Song ) 국제태권도학회 2016 Journal of the International Association for Taekw Vol.3 No.2

This study examined the long-term effects of Taekwondo training on bone mineral density (BMD), body composition, and physical fitness in middle-aged men. Thirty men (43 ± 2 yr) were divided into three groups based on Taekwondo experience and current training volume. The currently practicing Taekwondo group (TKDC: n = 10, training career: 34.1 yr) practiced Taekwondo ≥ 2 times per week. The former Taekwondo group (TKDS: n = 10, training career: 19.2 yr) trained during childhood and adolescence, but ceased training before age 30. The control group (CON: n = 10) received no regular physical training during youth. The results showed that both Taekwondo groups had a significantly higher BMD, (p < 0.004) and Z-scores (p < 0.008) for femoral neck and L4 BMD (p < 0.023). For physical fitness, both groups showed significantly better results for 50m shuttle run (p < 0.001) and sit-ups (p < 0.0004) than the control group. No significant difference was found in body composition among the groups. In conclusion, TKDC and TKDS may have had site-specific benefits for BMD. As there was no significant difference in these variables between the two Taekwondo groups, the benefits were most likely gained during childhood and adolescence, and further training did not appear to increase these gains. More research is needed with a larger sample size to confirm these findings.

미 대선 후보들의 노동정책 및 고용정책 비교

Jennifer Clark 한국노동연구원 2008 국제노동브리프 Vol.6 No.11

The RunSmart training program: effect on oxygen consumption and lower extremity biomechanics during running

Jennifer Bogulski,Steven Gonser,Doug Bush,Raechel Bugner,Lindsay Clark,Lisa Farrell,Kristen Swanson,Michael David Ross 한국운동재활학회 2017 JER Vol.13 No.4

Outstanding Laser Damage Threshold in Li₂MnGeS₄ and Tunable Optical Nonlinearity in Diamond-Like Semiconductors

Brant, Jacilynn A.,Clark, Daniel J.,Kim, Yong Soo,Jang, Joon I.,Weiland, Ashley,Aitken, Jennifer A. American Chemical Society 2015 Inorganic Chemistry Vol.54 No.6

<P>The new Li<SUB>2</SUB>MnGeS<SUB>4</SUB> and Li<SUB>2</SUB>CoSnS<SUB>4</SUB> compounds result from employing a rational and simple design strategy that guides the discovery of diamond-like semiconductors (DLSs) with wide regions of optical transparency, high laser damage threshold, and efficient second-order optical nonlinearity. Single-crystal X-ray diffraction was used to solve and refine the crystal structures of Li<SUB>2</SUB>MnGeS<SUB>4</SUB> and Li<SUB>2</SUB>CoSnS<SUB>4</SUB>, which crystallize in the noncentrosymmetric space groups <I>Pna</I>2<SUB>1</SUB> and <I>Pn</I>, respectively. Synchrotron X-ray powder diffraction (SXRPD) was used to assess the phase purity, and diffuse reflectance UV–vis–NIR spectroscopy was used to estimate the bandgaps of Li<SUB>2</SUB>MnGeS<SUB>4</SUB> (<I>E</I><SUB>g</SUB> = 3.069(3) eV) and Li<SUB>2</SUB>CoSnS<SUB>4</SUB> (<I>E</I><SUB>g</SUB> = 2.421(3) eV). In comparison with Li<SUB>2</SUB>FeGeS<SUB>4</SUB>, Li<SUB>2</SUB>FeSnS<SUB>4</SUB>, and Li<SUB>2</SUB>CoSnS<SUB>4</SUB> DLSs, Li<SUB>2</SUB>MnGeS<SUB>4</SUB> exhibits the widest region of optical transparency (0.60–25 μm) and phase matchability (≥1.6 μm). All four of the DLSs exhibit second-harmonic generation and are compared with the benchmark NLO material, AgGaSe<SUB>2</SUB>. Most remarkably, Li<SUB>2</SUB>MnGeS<SUB>4</SUB> does not undergo two- or three-photon absorption upon exposure to a fundamental Nd:YAG beam (λ = 1.064 μm) and exhibits a laser damage threshold > 16 GW/cm<SUP>2</SUP>.</P><P>New nonlinear optical (NLO) materials, Li<SUB>2</SUB>MnGeS<SUB>4</SUB> and Li<SUB>2</SUB>CoSnS<SUB>4</SUB>, are obtained using a steadfast design strategy for diamond-like semiconductors. Li<SUB>2</SUB>MnGeS<SUB>4</SUB> is the most promising NLO material for high-powered applications that use infrared radiation in comparison to Li<SUB>2</SUB>CoSnS<SUB>4</SUB>, Li<SUB>2</SUB>FeGeS<SUB>4</SUB>, and Li<SUB>2</SUB>FeSnS<SUB>4</SUB>. Li<SUB>2</SUB>MnGeS<SUB>4</SUB> exhibits second-harmonic generation (χ<SUP>(2)</SUP> = 15 pm/V), wide phase matchability (λ ≥ 1.6 μm), and a wide window of optical clarity (λ = 0.7−24 μm). Most remarkably, the laser damage threshold of Li<SUB>2</SUB>MnGeS<SUB>4</SUB> is > 16 GW/cm<SUP>2</SUP>.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/inocaj/2015/inocaj.2015.54.issue-6/ic502981r/production/images/medium/ic-2014-02981r_0011.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ic502981r'>ACS Electronic Supporting Info</A></P>

Bevacizumab in Recurrent Glioma: Patterns of Treatment Failure and Implications

( Yi Li ),( Saad Ali ),( Jennifer Clarke ),( Soonmee Cha ) 대한뇌종양학회 대한신경종양학회 2017 Brain Tumor Research and Treatment Vol.5 No.1

Glioblastoma, the most common primary malignant brain tumor in adults, is highly aggressive and associated with a poor prognosis. Bevacizumab, a monoclonal antibody against the vascular endothelial growth factor receptor, has increasingly been used in the treatment of recurrent glioblastoma. It has achieved excellent rates of radiographic response, but most patients will progress after only a few months. Upon recurrence, tumors may not enhance, secondary to vascular normalization. We describe four patterns of radiographic progression commonly associated with Bevacizumab failure: 1) Distant enhancing tumor, 2) Local tumor progression without enhancement, 3) Diffuse gliomatosis-like infiltration, and 4) Local or multifocal progression, with enhancement. Some have noted an increased incidence of distant or diffuse disease upon recurrence, suggestive of a transition to a more aggressive phenotype, but a review of the literature suggests there is no conclusive evidence that Bevacizumab treatment is associated with an increased rate of distant or diffuse recurrence.

Infrared nonlinear optical properties of lithium-containing diamond-like semiconductors Li₂ZnGeSe₄ and Li₂ZnSnSe₄

Zhang, Jian-Han,Clark, Daniel J.,Brant, Jacilynn A.,Sinagra, Charles W.,Kim, Yong Soo,Jang, Joon I.,Aitken, Jennifer A. The Royal Society of Chemistry 2015 Dalton Transactions Vol.44 No.24

<P>Two new lithium-containing diamond-like semiconductors, Li<SUB>2</SUB>ZnGeSe<SUB>4</SUB> and Li<SUB>2</SUB>ZnSnSe<SUB>4</SUB>, have been prepared by high-temperature, solid-state synthesis. Single crystal X-ray diffraction reveals that both compounds adopt the wurtz–kesterite structure type, crystallizing in the noncentrosymmetric space group <I>Pn</I>. X-ray powder diffraction coupled with Rietveld refinement indicates the high degree of phase purity in which the materials are prepared. Both compounds display optical bandgaps around 1.8 eV, wide optical transparency windows from 0.7 to 25 μm and type-I phase matched second harmonic generation starting at 2500 nm and persisting deeper into the infrared. Using the Kurtz powder method, the second-order nonlinear optical coefficient, <I>χ</I><SUP>(2)</SUP>, was estimated to be 19 and 23 pm V<SUP>−1</SUP> for Li<SUB>2</SUB>ZnGeSe<SUB>4</SUB> and Li<SUB>2</SUB>ZnSnSe<SUB>4</SUB>, respectively. Using a 1064 nm incident laser beam with a pulse width (<I>τ</I>) of 30 ps both compounds exhibit a laser damage threshold of 0.3 GW cm<SUP>−2</SUP>, which is higher than that of the AgGaSe<SUB>2</SUB> reference material measured under identical conditions. Differential thermal analysis shows that the title compounds are stable up to 684 and 736 °C, respectively. These properties collectively demonstrate that Li<SUB>2</SUB>ZnGeSe<SUB>4</SUB> and Li<SUB>2</SUB>ZnSnSe<SUB>4</SUB> have great potential for applications in tunable laser systems, especially in the infrared and even up to the terahertz regime. Electronic structure calculations using a plane-wave pseudopotential method within density functional theory provide insight regarding the nature of the bandgap and bonding.</P> <P>Graphic Abstract</P><P>Two new lithium-containing diamond-like semiconductors were synthesized, and the nonlinear optical properties were studied. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5dt01635e'> </P>

Li₂CdGeS₄, A Diamond-Like Semiconductor with Strong Second-Order Optical Nonlinearity in the Infrared and Exceptional Laser Damage Threshold

Brant, Jacilynn A.,Clark, Daniel J.,Kim, Yong Soo,Jang, Joon I.,Zhang, Jian-Han,Aitken, Jennifer A. American Chemical Society 2014 Chemistry of materials Vol.26 No.10

<P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2014/cmatex.2014.26.issue-10/cm501029s/production/images/medium/cm-2014-01029s_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm501029s'>ACS Electronic Supporting Info</A></P>

Optical Nonlinearity in Cu₂CdSnS₄ and α/β-Cu₂ZnSiS₄: Diamond-like Semiconductors with High Laser-Damage Thresholds

Rosmus, Kimberly A.,Brant, Jacilynn A.,Wisneski, Stephen D.,Clark, Daniel J.,Kim, Yong Soo,Jang, Joon I.,Brunetta, Carl D.,Zhang, Jian-Han,Srnec, Matthew N.,Aitken, Jennifer A. American Chemical Society 2014 Inorganic Chemistry Vol.53 No.15

<P>Cu<SUB>2</SUB>CdSnS<SUB>4</SUB> and α/β-Cu<SUB>2</SUB>ZnSiS<SUB>4</SUB> meet several criteria for promising nonlinear optical materials for use in the infrared (IR) region. Both are air-stable, crystallize in noncentrosymmetric space groups, and possess high thermal stabilities. Cu<SUB>2</SUB>CdSnS<SUB>4</SUB> and α/β-Cu<SUB>2</SUB>ZnSiS<SUB>4</SUB> display wide ranges of optical transparency, 1.4–25 and 0.7–25 μm, respectively, and have relatively large second-order nonlinearity as well as phase matchability for wide regions in the IR. The laser-damage threshold (LDT) for Cu<SUB>2</SUB>CdSnS<SUB>4</SUB> is 0.2 GW/cm<SUP>2</SUP>, whereas α/β-Cu<SUB>2</SUB>ZnSiS<SUB>4</SUB> has a LDT of 2.0 GW/cm<SUP>2</SUP> for picosecond near-IR excitation. Both compounds also exhibit efficient third-order nonlinearity. Electronic structure calculations provide insight into the variation in properties.</P><P>Changing Sn<SUP>4+</SUP> to Si<SUP>4+</SUP> in the I<SUB>2</SUB>−II−IV−VI<SUB>4</SUB> formula has significant effects on the characteristics critical for nonlinear optical applications. The air-stable, noncentrosymmetric, diamond-like Cu<SUB>2</SUB>CdSnS<SUB>4</SUB> and α/β-Cu<SUB>2</SUB>ZnSiS<SUB>4</SUB> exhibit significant second- and third-order nonlinearity. These materials are practical for applications because of their elevated thermal stabilities, wide optical transparency windows, broad regions of phase matchability for second harmonic generation, and high laser-damage thresholds (LDTs). The LDT of the wide-gap α/β-Cu<SUB>2</SUB>ZnSiS<SUB>4</SUB> surpasses that of commercially available materials.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/inocaj/2014/inocaj.2014.53.issue-15/ic501310d/production/images/medium/ic-2014-01310d_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ic501310d'>ACS Electronic Supporting Info</A></P>

Does Pre-season Training Improve Body Composition, Physical Fitness, and Isokinetic Muscle Strength in Female Taekwondo Athletes?

( Jong-kook Song ),( Duk-jae Han ),( Hyun-chul Jung ),( Hyo-jung Kang ),( Myong-won Seo ),( Jennifer Ann Clarke ),( Hyun-bae Kim ) 국제태권도학회 2015 Journal of the International Association for Taekw Vol.2 No.1

The aim of this study was to examine the effects of a 6-week pre-season Taekwondo training program on body composition, physical fitness, and isokinetic muscular strength in female athletes. Twenty-two collegiate female athletes with mean ages ranging from 18.8 to 19.4 years participated. They were divided into four groups according to their weight categories: G1 (≤49 kg), G2 (>49 kg-57 kg), G3 (>57-67 kg), and G4 (>67 kg). The training program included 3 sessions a day, 3 days a week for 6 weeks. Body composition parameters were measured by Dual X-Ray Absorptiometry (DXA). Physical fitness tests including sit and reach, grip strength, sit-ups, standing long jump, 50 m shuttle run, and 20 m multi-stage endurance shuttle run were applied. Isokinetic strength was measured by an isokinetic dynamometer. The extensors and flexors of the knee and trunk were tested at three fixed angular velocities (60°·s^-1, 120°·s^-1, and 240°·s^-1). Significant time x group interaction effects were found for fat tissue (p < 0.05). G4 demonstrated significant decreases in fat tissue (p < 0.01) and percent body fat (p < 0.05) after the training program. However, no significant changes were found for body mass, lean tissue, and bone mineral density in all groups. G1 demonstrated significant improvements on the 50 m shuttle run (p < 0.001) and the multistage endurance run (p < 0.001), while G2 showed significant changes for grip strength (p < 0.01), the 50 m shuttle run (p < 0.01), and the multistage endurance run (p < 0.05). G1 demonstrated significant improvement in left extension (p < 0.0001) and left flexion (p < 0.05) at 60°·s^-1, left flexion (p < 0.001) at 120°·s^-1, and all variables at 240°·s^-1. Significant changes were also found in G2 (left and right extension at 60°·s-1 and 120°·s^-1; right and left flexion at 240°·s^-1), and in G3 (left extension at 60°·s^-1, 120°·s^-1, and 240°·s^-1). However, the training had no effect on trunk isokinetic strength in all groups. In conclusion, this study suggests that a pre-season training program may decrease body fat, while improving agility, endurance, and knee muscular strength in specific weight categories of female Taekwondo athletes. However, this specific type of training should not be considered as an alternative training method for trunk strength in female athletes.

Stem cells act through multiple mechanisms to benefit mice with neurodegenerative metabolic disease

Lee, Jean-Pyo,Jeyakumar, Mylvaganam,Gonzalez, Rodolfo,Takahashi, Hiroto,Lee, Pei-Jen,Baek, Rena C,Clark, Dan,Rose, Heather,Fu, Gerald,Clarke, Jonathan,McKercher, Scott,Meerloo, Jennifer,Muller, Franz- Nature Publishing Group 2007 Nature medicine Vol.13 No.4

Intracranial transplantation of neural stem cells (NSCs) delayed disease onset, preserved motor function, reduced pathology and prolonged survival in a mouse model of Sandhoff disease, a lethal gangliosidosis. Although donor-derived neurons were electrophysiologically active within chimeric regions, the small degree of neuronal replacement alone could not account for the improvement. NSCs also increased brain β-hexosaminidase levels, reduced ganglioside storage and diminished activated microgliosis. Additionally, when oral glycosphingolipid biosynthesis inhibitors (β-hexosaminidase substrate inhibitors) were combined with NSC transplantation, substantial synergy resulted. Efficacy extended to human NSCs, both to those isolated directly from the central nervous system (CNS) and to those derived secondarily from embryonic stem cells. Appreciating that NSCs exhibit a broad repertoire of potentially therapeutic actions, of which neuronal replacement is but one, may help in formulating rational multimodal strategies for the treatment of neurodegenerative diseases.