THE EFFECTS OF CLEAT LOCATION ON MUSCLE RECRUITMENT STRATEGIES OF CYCLING

Foot placement may play an important role in muscle recruitment patterns and affect cycling performance. The purpose of this study was to determine if magnitude of activation increased in more proximal muscles when a more posterior compared to standard cleat location is used. Surface electromyography (8 muscles) and kinematics were collected from 11 experienced cyclists pedalling at 80 rpm rate during standard and posterior cleat location conditions. Root mean square (RMS) EMG were analyzed using paired t-tests. Peak RMS magnitude and crank angle of peak RMS were affected by cleat conditions. Posterior cleat locations alter the magnitude and muscular recruitment strategies of seated cycling when compared to neutral cleat placement

COMPARISON OF LINEAR AND ANGULAR SWING VELOCITIES WITH DIFFERENTLY WEIGHTED WARM-UP BATS IN SOFTBALL PLAYERS

Swing velocity has been considered as one of the essential factors of bat swing biomechanics, and traditionally coaches and players think it can be altered by using a differently weighted bat for warm-up before an at bat. The purpose of this study was to examine the effects of 3 differently weighted warm-up bats on 3D linear and angular kinematics. Ten female varsity softball players were recruited and bat swing kinematics with normal (NW), heavy (HW), and light (LW) weighted warm-up bats were collected. Both linear and angular kinematic variables were compared between different bat weights using RMANOVA. Only 1 velocity variable difference between LW and NW, and 4 temporal differences between HW and NW were found. It is suggested that in general, swing kinematics is not altered by differently weighted bats warm-up prior maximal swing

4-Amino-3-methyl­benzoic acid–1,2-bis­(4-pyrid­yl)ethane (1/1)

In the crystal structure of the title 1:1 adduct, C12H12N2·C8H9NO2, the 4-amino-3-methyl­benzoic acid mol­ecules and 1,2-bis­(4-pyrid­yl)ethane mol­ecules are linked by inter­molecular O—H⋯N, N—H⋯O and N—H⋯N hydrogen bonds, forming a two-dimensional supra­molecular network parallel to (001). In the 1,2-bis­(4-pyrid­yl)ethane mol­ecule, the two pyridine rings are twisted to each other by a dihedral angle of 12.12 (8)°. The non-H atoms of the 4-amino-3-methyl­benzoic acid mol­ecule are almost coplanar, the maximum atomic deviation being 0.029 (1) Å. Weak C—H⋯π inter­actions are present in the crystal structure

Does interlimb knee symmetry exist after unicompartmental knee arthroplasty? Knee

BACKGROUND: Unicompartmental knee arthroplasty (UKA) has long been a treatment option for patients with disease limited primarily to one compartment with small, correctable deformities. However, some surgeons presume that normal kinematics of a lateral compartment UKA are difficult to achieve. Furthermore, it is unclear whether UKA restores normal knee kinematics and interlimb symmetry. QUESTIONS/PURPOSES: We determined knee kinematics exhibited during stair ascent by patients with medial- (MED-UKA) or lateral-UKA (LAT-UKA) and if the knee kinematics of the operated and nonoperated limbs were symmetrical. METHODS: Participants were 17 individuals with MED-UKA and nine with LAT-UKA, all with nondiseased contralateral limbs. For each limb, participants walked up four stairs for five trials while a motion-capture system obtained reflective marker locations. Temporal events were determined by force platform signals. Interlimb symmetry was classified for temporal gait and knee angular kinematics by comparing observed interlimb differences with clinically meaningful differences set at 5% of stride time for temporal variables and 5° for angular variables. The minimum postoperative followup was 6 months (median, 24 months; range, 6-53 months). RESULTS: Neither group demonstrated clinically meaningful mean interlimb differences. However, approximately half of participants of each UKA group displayed asymmetry favoring the operative or nonoperative limb with similar frequency. CONCLUSIONS: Many patients undergoing UKA demonstrate kinematic interlimb symmetry during stair ascent. Interlimb asymmetry may be affected by a variety of factors unrelated to the UKA. CLINICAL RELEVANCE: A MED- or LAT-UKA can potentially restore normal knee function for a demanding task of daily life

Does Long-Term Use of Silver Nanoparticles Have Persistent Inhibitory Effect on H. pylori Based on Mongolian Gerbil’s Model?

It is urgent to find alternative agents due to increasing failure rate of Helicobacter pylori (H. pylori) eradication. The study surveyed the long-term effect of silver nanoparticles (AgNP) on H. pylori based on Mongolian gerbil's model

Mechanical regulation of cancer cell apoptosis and autophagy: Roles of bone morphogenetic protein receptor, Smad1/5, and p38 MAPK

AbstractMechanical forces induced by interstitial fluid flow in and surrounding tissues and by blood/lymphatic flow in vessels may modulate cancer cell invasion and metastasis and anticancer drug delivery. Our previous study demonstrated that laminar flow-induced shear stress induces G2/M arrest in tumor cells. However, whether shear stress modulates final cell fate remains unclear. In this study, we investigated the role of flow-induced shear stress in modulating the survival of four human tumor cell lines, i.e., Hep3B hepatocarcinoma cells, MG63 osteosarcoma cells, SCC25 oral squamous carcinoma cells, and A549 carcinomic alveolar basal epithelial cells. Laminar shear stress (LSS) ranging from 0.5 to 12dyn/cm2 induced death of these four tumor cell lines. In contrast to LSS at 0.5dyn/cm2, oscillatory shear stress (OSS) at 0.5±4dyn/cm2 cannot induce cancer cell death. Both LSS and OSS had no effect on human normal hepatocyte, lung epithelial, and endothelial cells. Application of LSS to these four cell lines increased the percentage of cells stained positively for annexin V–FITC, with up-regulations of cleaved caspase-8, -9, and -3, and PARP. In addition, LSS also induced Hep3B cell autophagy, as detected by acidic vesicular organelle formation, LC3B transformation, and p62/SQSTM1 degradation. By transfecting with small interfering RNA, we found that the shear-induced apoptosis and autophagy are mediated by bone morphogenetic protein receptor type (BMPR)-IB, BMPR-specific Smad1 and Smad5, and p38 mitogen-activated protein kinase in Hep3B cells. Our findings provide insights into the molecular mechanisms by which shear stress induces apoptosis and autophagy in tumor cells

Knee moments after unicompartmental knee arthroplasty during stair ascent knee

BACKGROUND: For unicompartmental knee arthroplasty (UKA), abnormal loading on the tibiofemoral joint could exacerbate knee osteoarthritis or implant wear. Joint moments are an indirect measure of such loading. However, little is known about knee moments of patients with UKA, tempering enthusiasm for its use. QUESTIONS/PURPOSES: In patients with UKAs performing stair ascent, we (1) determined whether interlimb differences for knee moments are demonstrated, (2) described the knee kinetics of patients with medial and lateral UKAs, and (3) investigated possible factors that might influence the knee abductor moments. METHODS: In our cross-sectional study, we recruited 26 patients with UKA with nondiseased contralateral limbs who performed stair ascent. Seventeen patients had medial UKAs and nine had lateral UKAs. Paired t-tests and CIs were applied to determine interlimb differences within each UKA group for peak knee moments and times to peak moments. RESULTS: During stair ascent, the medial UKA group displayed greater peak extensor moments for the nondiseased compared to the UKA limb (p = 0.030), whereas the lateral UKA group did not (p = 0.087). For both medial and lateral UKA groups, the UKA limb demonstrated greater internal peak abductor moments (p = 0.005 and 0.013, respectively). Both UKA groups exhibited knee moments similar to those in the literature. Limb dominance and postoperative time were correlated for both UKA groups. CONCLUSIONS: Reduced knee extensor moments of limbs with UKA displayed by some participants may indicate less compressive loading on the tibiofemoral joint surfaces, whereas the increased abductor moments suggest increased compression on the medial compartment. These findings suggest UKA knees may not be subjected to excessive loads regardless of the side reconstructed

The Hidden Hydroxide in BaNiO3 Single Crystals Grown from a KOH Flux

Hexagonal oxide perovskites with one-dimensional chains of face-sharing MO6 octahedra are of enduring interest. Specifically, the hexagonal perovskite BaNiO3, prepared via non-ceramic approaches, acts as a highly functional catalyst for the oxygen-evolution reaction (OER) in alkaline media, with numerous studies focusing on this behavior, while its fundamental structural and physical properties have been somewhat overlooked. The current work is intiated by the observation of contrasting magnetic properties of BaNiO3 synthesized via KOH flux growth and high O2 pressure ceramic synthesis. To shed light on this difference, we have performed a series of rigorous analyses and found that the KOH flux-grown crystals made in open-air are actually a wet form of BaNiO3 that can be dried upon annealing in O2 flow but will then slowly degrade if stored under a condition where the O2 partial pressure is not high enough. Therefore, the present work not only provides insightful information to unveil a previously unknown aspect of the OER catalyst BaNiO3, but also rings a bell that the hidden hydroxide principle described here may also be applied to other hexagonal perovskite oxides prepared in wet conditions.Comment: 21 pages, 6 figure

KCNN2 polymorphisms and cardiac tachyarrhythmias

Potassium calcium-activated channel subfamily N member 2 (KCNN2) encodes an integral membrane protein that forms small-conductance calcium-activated potassium (SK) channels. Recent studies in animal models show that SK channels are important in atrial and ventricular repolarization and arrhythmogenesis. However, the importance of SK channels in human arrhythmia remains unclear. The purpose of the present study was to test the association between genetic polymorphism of the SK2 channel and the occurrence of cardiac tachyarrhythmias in humans. We enrolled 327 Han Chinese, including 72 with clinically significant ventricular tachyarrhythmias (VTa) who had a history of aborted sudden cardiac death (SCD) or unexplained syncope, 98 with a history of atrial fibrillation (AF), and 144 normal controls. We genotyped 12 representative tag single nucleotide polymorphisms (SNPs) across a 141-kb genetic region containing the KCNN2 gene; these captured the full haplotype information. The rs13184658 and rs10076582 variants of KCNN2 were associated with VTa in both the additive and dominant models (odds ratio [OR] 2.89, 95% confidence interval [CI] = 1.505-5.545, P = 0.001; and OR 2.55, 95% CI = 1.428-4.566, P = 0.002, respectively). After adjustment for potential risk factors, the association remained significant. The population attributable risks of these 2 variants of VTa were 17.3% and 10.6%, respectively. One variant (rs13184658) showed weak but significant association with AF in a dominant model (OR 1.91, CI = 1.025-3.570], P = 0.042). There was a significant association between the KCNN2 variants and clinically significant VTa. These findings suggest an association between KCNN2 and VTa; it also appears that KCNN2 variants may be adjunctive markers for risk stratification in patients susceptible to SCD