Great power comes at a high (locomotor) cost: the role of muscle fascicle length in the power versus economy performance trade-off.

Muscle design constraints preclude simultaneous specialization of the vertebrate locomotor system for explosive and economical force generation. The resulting performance trade-off between power and economy has been attributed primarily to individual differences in muscle fiber type composition. While certainly crucial for performance specialization, fiber type likely interacts with muscle architectural parameters, such as fascicle length, to produce this trade-off.

Structure Determination of Boron-Based Oxidative Dehydrogenation Heterogeneous Catalysts with Ultra-High Field 35.2 T B Solid-State NMR Spectroscopy.

Boron-based heterogenous catalysts, such as hexagonal boron nitride (-BN) as well as supported boron oxides, are highly selective catalysts for the oxidative dehydrogenation (ODH) of light alkanes to olefins. Previous catalytic measurements and molecular characterization of boron-based catalysts by B solid-state NMR spectroscopy and other techniques suggests that oxidized/hydrolyzed boron clusters are the catalytically active sites for ODH. However, B solid-state NMR spectroscopy often suffers from limited resolution because boron-11 is an = 3/2 half-integer quadrupolar nucleus.

Extreme enhanced myometrial vascularity following cesarean scar pregnancy: a new diagnostic entity.

Objective: To define, illustrate and to follow-up the diagnosis, pathophysiology and treatment of a subset of the known enhanced myometrial vascularity (EMV): its extreme form, associated with cesarean scar pregnancies (CSP) and with some cases pf placenta accreta spectrum being at increased risk of significant bleeding complications. We also aim to provide guidance to the management of such cases.

Material And Methods: This is an IRB-approved retrospective observational study of thirteen patients with an extreme form of EMV complicating CSPs.

Leukocytoclastic vasculitis as a rare dermatologic manifestation of Crohn's disease mimicking cellulitis: a case report.

Background: Leukocytoclastic vasculitis (LCV) is an immune-complex mediated vasculitis characterized by neutrophilic inflammation and nuclear debris in post capillary venules. LCV is a rare dermatologic manifestation of Crohn's disease (CD) and may occur with the onset of the disease or any time after the diagnosis including the period of exacerbation.

Case Presentation: We present a 70 year old woman with history of psoriasis and treatment refractory CD requiring monoclonal antibody therapy with ustekinumab.

Why Boron Nitride is such a Selective Catalyst for the Oxidative Dehydrogenation of Propane.

Boron-containing materials, and in particular boron nitride, have recently been identified as highly selective catalysts for the oxidative dehydrogenation of alkanes such as propane. To date, no mechanism exists that can explain both the unprecedented selectivity, the observed surface oxyfunctionalization, and the peculiar kinetic features of this reaction. We combine catalytic activity measurements with quantum chemical calculations to put forward a bold new hypothesis.

Septic Shock and Purpura Fulminans Due to Streptococcus pneumoniae Bacteremia in an Unvaccinated Immunocompetent Adult: Case Report and Review.

BACKGROUND Despite proven efficacy of vaccinations against Streptococcus pneumoniae in preventing infection, only 70% of eligible individuals receive the vaccine in the United States. Pneumococcal bacteremia represents a form of invasive pneumococcal disease and is associated with high mortality, especially in immunocompromised patients and the elderly. Purpura fulminans is a rare complication and manifestation of disseminated intravascular coagulation and sepsis.

Serial Hurricanes The 2017 Hurricane Public Health Responses: Case Studies Illustrating the Role of Centers for Disease Control and Prevention's Public Health Emergency Preparedness Program.

The Centers for Disease Control and Prevention (CDC), Division of State and Local Readiness (DSLR), Public Health Emergency Preparedness(PHEP) program funds 62 recipients to strengthen capability standards to prepare for and respond to public health emergencies. Recipients use these PHEP resources in addition to CDC's administrative and scientific guidance to support preparedness and response program planning and requirements. It is expected that public health agencies develop and maintain comprehensive emergency preparedness and response plans in preparation for disasters such as hurricanes.

B-MWW Zeolite: The Case Against Single-Site Catalysis.

Boron-containing materials have recently been identified as highly selective catalysts for the oxidative dehydrogenation (ODH) of alkanes to olefins. It has previously been demonstrated by several spectroscopic characterization techniques that the surface of these boron-containing ODH catalysts oxidize and hydrolyze under reaction conditions, forming an amorphous B (OH) O (x=0-6) layer. Yet, the precise nature of the active site(s) remains elusive.

Selective Oxidative Cracking of n-Butane to Light Olefins over Hexagonal Boron Nitride with Limited Formation of CO.

In recent years, hexagonal boron nitride (hBN) has emerged as an unexpected catalyst for the oxidative dehydrogenation of alkanes. Here, the versatility of hBN was extended to alkane oxidative cracking chemistry by investigating the production of ethylene and propylene from n-butane. Cracking selectivity was primarily controlled by the ratio of n-butane to O within the reactant feed.

Probing the Transformation of Boron Nitride Catalysts under Oxidative Dehydrogenation Conditions.

Hexagonal boron nitride (h-BN) and boron nitride nanotubes (BNNT) were recently reported as highly selective catalysts for the oxidative dehydrogenation (ODH) of alkanes to olefins in the gas phase. Previous studies revealed a substantial increase in surface oxygen content after exposure to ODH conditions (heating to ca. 500 °C under a flow of alkane and oxygen); however, the complexity of these materials has thus far precluded an in-depth understanding of the oxygenated surface species.

Serendipity in Catalysis Research: Boron-Based Materials for Alkane Oxidative Dehydrogenation.

Light olefins such as ethylene and propylene form the foundation of the modern chemical industry, with yearly production volumes well into the hundreds of millions of metric tons. Currently, these light olefins are mainly produced via energy-intensive steam cracking. Alternatively, oxidative dehydrogenation (ODH) of light alkanes to produce olefins allows for lower operation temperatures and extended catalyst lifetimes, potentially leading to valuable process efficiencies.

Aerobic Oxidations of Light Alkanes over Solid Metal Oxide Catalysts.

Heterogeneous metal oxide catalysts are widely studied for the aerobic oxidations of C-C alkanes to form olefins and oxygenates. In this review, we outline the properties of supported metal oxides, mixed-metal oxides, and zeolites and detail their most common applications as catalysts for partial oxidations of light alkanes. By doing this we establish similarities between different classes of metal oxides and identify common themes in reaction mechanisms and research strategies for catalyst improvement.

Selective oxidative dehydrogenation of propane to propene using boron nitride catalysts.

The exothermic oxidative dehydrogenation of propane reaction to generate propene has the potential to be a game-changing technology in the chemical industry. However, even after decades of research, selectivity to propene remains too low to be commercially attractive because of overoxidation of propene to thermodynamically favored CO Here, we report that hexagonal boron nitride and boron nitride nanotubes exhibit unique and hitherto unanticipated catalytic properties, resulting in great selectivity to olefins. As an example, at 14% propane conversion, we obtain selectivity of 79% propene and 12% ethene, another desired alkene.

Bone strength estimates relative to vertical ground reaction force discriminates women runners with stress fracture history.

Purpose: To determine differences in bone geometry, estimates of bone strength, muscle size and bone strength relative to load, in women runners with and without a history of stress fracture.

Methods: We recruited 32 competitive distance runners aged 18-35, with (SFX, n=16) or without (NSFX, n=16) a history of stress fracture for this case-control study. Peripheral quantitative computed tomography (pQCT) was used to assess volumetric bone mineral density (vBMD, mg/mm), total (ToA) and cortical (CtA) bone areas (mm), and estimated compressive bone strength (bone strength index; BSI, mg/mm) at the distal tibia.

Effect of running speed and leg prostheses on mediolateral foot placement and its variability.

This study examined the effects of speed and leg prostheses on mediolateral (ML) foot placement and its variability in sprinters with and without transtibial amputations. We hypothesized that ML foot placement variability would: 1. increase with running speed up to maximum speed and 2.

Dynamic stability of running: the effects of speed and leg amputations on the maximal Lyapunov exponent.

In this paper, we study dynamic stability during running, focusing on the effects of speed, and the use of a leg prosthesis. We compute and compare the maximal Lyapunov exponents of kinematic time-series data from subjects with and without unilateral transtibial amputations running at a wide range of speeds. We find that the dynamics of the affected leg with the running-specific prosthesis are less stable than the dynamics of the unaffected leg and also less stable than the biological legs of the non-amputee runners.

Chronic eccentric cycling improves quadriceps muscle structure and maximum cycling power.

An interesting finding from eccentric exercise training interventions is the presence of muscle hypertrophy without changes in maximum concentric strength and/or power. The lack of improvements in concentric strength and/or power could be due to long lasting suppressive effects on muscle force production following eccentric training. Thus, improvements in concentric strength and/or power might not be detected until muscle tissue has recovered (e.

Electromyographic analysis of the rotator cuff in postoperative shoulder patients during passive rehabilitation exercises.

Background: Numerous rehabilitation protocols exist for postoperative rotator cuff repairs. Because the goal of early rehabilitation is to prevent postoperative adhesions while protecting the repaired tendons, it would be advantageous to know which range-of-motion exercises allow the rotator cuff to remain the most passive in a painful, guarded, postsurgical shoulder.

Methods: Twenty-six subjects who had undergone subacromial decompression, distal clavicle resection, or a combination of both procedures volunteered to participate within the first 4 days after surgery.

Leg stiffness of sprinters using running-specific prostheses.

Running-specific prostheses (RSF) are designed to replicate the spring-like nature of biological legs (bioL) during running. However, it is not clear how these devices affect whole leg stiffness characteristics or running dynamics over a range of speeds. We used a simple spring-mass model to examine running mechanics across a range of speeds, in unilateral and bilateral transtibial amputees and performance-matched controls.

Locomotor-respiratory coupling patterns and oxygen consumption during walking above and below preferred stride frequency.

Locomotor respiratory coupling patterns in humans have been assessed on the basis of the interaction between different physiological and motor subsystems; these interactions have implications for movement economy. A complex and dynamical systems framework may provide more insight than entrainment into the variability and adaptability of these rhythms and their coupling. The purpose of this study was to investigate the relationship between steady state locomotor-respiratory coordination dynamics and oxygen consumption [Formula: see text] of the movement by varying walking stride frequency from preferred.

Running-specific prostheses limit ground-force during sprinting.

Running-specific prostheses (RSP) emulate the spring-like behaviour of biological limbs during human running, but little research has examined the mechanical means by which amputees achieve top speeds. To better understand the biomechanical effects of RSP during sprinting, we measured ground reaction forces (GRF) and stride kinematics of elite unilateral trans-tibial amputee sprinters across a range of speeds including top speed. Unilateral amputees are ideal subjects because each amputee's affected leg (AL) can be compared with their unaffected leg (UL).

Nm23-H1 suppresses metastasis by inhibiting expression of the lysophosphatidic acid receptor EDG2.

Nm23-H1 transcriptionally down-regulates expression of the lysophosphatidic acid receptor EDG2 and this down-regulation is critical for Nm23-H1-mediated motility suppression in vitro. We investigated the effect of altered EDG2 expression on Nm23-H1-mediated metastasis suppression in vivo. Clonal MDA-MB-435-derived tumor cell lines transfected with Nm23-H1 together with either a vector control or EDG2 had similar anchorage-dependent and anchorage-independent growth rates in vitro.