bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrodynamic Interaction of Floating Structure in Regular Waves
Authors: Abyn Hassan , Maimun Adi , Jaswar Jaswar , Rafiqul Islam M. , Magee Allan , Bodaghi Behnam , Pauzi Mohamad , Siow C. L. , Mobassher Tofa M.
Published: March 2014

Floating structures play an important role for exploring the oil and gas from the sea. In loading and offloading, motion responses of offshore floating structures are affected through hydrodynamic interaction. Large motions between floating bodies would cause the damage of moorings, offloading system and may colloid to each other. This research studies on hydrodynamic interaction between Tension Leg Platform (TLP) and Semi-Submersible (Tender Assisted Drilling (TAD)) in regular and irregular waves with scenario as follows: fixed TLP and 6-DOF floating semi-submersible and 6-DOF both TLP and semi-submersible. Under these conditions, hydrodynamics coefficients, mooring and connectors forces, motions and relative motions of TLP and Semi-Submersible will be simulated numerically by using 3D source distribution method. As the scope is big, this paper only presents model experiment of floating TLP and semi-submersible in the regular wave. The experiment is carried out in the UTM Towing Tank.
Characterization of a Low NOx Flameless Combustion Burner Using Natural Gas
Authors: Abuelnuor A. A. A. , A. Wahid Mazlan , Osman M.
Published: March 2014

Flameless combustion is a method that has a great potential in reducing pollutant emission from combustion process. In this work, the operation and emission of a laboratory scale furnace under the flameless combustion regime using natural gas as a fuel was examined. In the experimental setup, the combustor was equipped with parallel jet burner systems with controlled gas fuel and oxidizer. Several ports have been integrated in the combustor to allow for temperature and combustion emission measurement. In the study, a comparison between flameless combustion with and without preheated combustion air has been made. The atmospheric air was heated to near the auto ignition temperature by a coil placed within the furnace assembly. The results show that flameless combustion mode could be obtained with and without preheated combustion air. The results also revealed that the laboratory scale furnace could successfully operate in flameless combustion regime using natural gas as fuel. In terms of emission, it was found that flameless combustion was more effective than the conventional combustion in reducing the rate of NOX emission.
Numerical Simulation on Wave Interference of Catamaran with Fin Stabilizer
Authors: Ali Arifah , Maimun Adi , M. Ahmed Yasser
Published: March 2014

Generated wave pattern of twin hull ship is important in analyzing wave interference between hulls. As each hull will generate own wave pattern, which might be identical for both hulls, the interference of wave generated can be either amplification or reduction factor for wave making resistance of the twin hull ship. Free Surface Flow is important to be considered in wave making resistance analysis of twin hull including hull with fin stabilizer, especially for ship operates in shallow water condition. Computational analysis using Computational Fluid Dynamics (CFD) simulation is performed using Reynolds Average Navier-Stokes (RANS) to solve free surface effect problem. The method which applied is Volume of Fluid method, considering two phase condition. The objective of simulation is to predict the wave making resistance and flow pattern of catamaran with and without fin stabilizer, considering the relationship between wave interference and fins stabilizer. The analysis is performed in two configurations, bare hulls and hulls attached with fins. For both configurations, the investigation was conducted with range of model speed from 10 to 20 knots using k-epsilon turbulence model in shallow water condition. The results were based on pressure resistance (Rp) and flow pattern around hulls.
Friction Characteristics of Liquid Lubricated MEMS with Deterministic Boundary Slippage
Authors: Tauviqirrahman Mohammad , Muchammad Muchammad , Ismail Rifky , Jamari Jamari , Schipper Dik J.
Published: March 2014

It has been proven experimentally that boundary slippage represents a viable effect on the hydrodynamic performance of lubricated sliding contacts. Along with several friction reduction mechanisms that have been explored in the literature, the slippage parameters remain an important feature. With the main objective of evaluating the effects of the slippage, a modified Reynolds equation is employed. The result shows that deterministic boundary slippage of the lubricated-MEMS with uniform film thickness has a very beneficial effect on decreasing friction force as well as coefficient of friction.
Effect of Surface Texturing Arrangement for Improving Anti-Seizure Property of Lead-Free Copper Alloy
Authors: Kuroiwa Yuki , Amanov Auezhan , Tsuboi Ryo , Sasaki Shinya , Kato Shinji
Published: March 2014

Lead-bronze is widely used in the automotive industry owing to its excellent anti-seizure property. However, lead is toxic, and thus, from an environmental viewpoint, there is a demand for a lead-free copper alloy in the automotive industry. Despite the anti-seizure property of lead-free copper alloy being comparable to that of lead-bronze, it has not yet been well exploited. Therefore, the objective of this study was to improve the anti-seizure property of lead-free copper alloy using a laser surface texturing (LST) method. A ring-on-ring sliding friction tester was used to assess the effectiveness of LST and to investigate the effect of surface texturing arrangement on the anti-seizure property of lead-free copper alloy. In the friction tests, upper specimens made of FCD700 and lower specimens made of PBC2 (lead-free copper alloy) were used. Paraffinic oil was used as a lubricant and was circulated using a pump. Results of the friction tests showed that the textured specimens demonstrated superior anti-seizure property to that of the non-textured specimens. Further, on the basis of the obtained experimental results, it was concluded that the arrangement of dimples plays an important role in improving the anti-seizure property of lead-free alloy.
Sleep Phenomena from the Perspectives of Islam and Science
Authors: Mohd Yusof Farahwahida , Muhamad Siti Norlina , Rosman Arieff Salleh , Ahmad Sarimah Noor , Razak Nor Farhah , Hashim Nor Izzati , Awang Asmahani
Published: March 2014

This article discusses the phenomenon of sleep, with emphasized to its importance, sleeping times, sleeping positions and even the etiquette of sleeping, from the views of Islam and Science. The Quran and Science are inseparable and the relationship between the two is highly balanced. Scientists have said that the phenomena of sleep is a miracle that deserves to be analysed and studied in depth, as it is a complex phenomena. Glory and Praise to be Allah Almighty has decreed in the Quran of the importance of sleep in the day and night, and that sleep is one of the signs of Allah’s Almighty power and is a miracle to be studied by each individual. Islam places great importance on taking care of one’s body and sleep is one need that has to be fulfilled. Scientists have stressed that sleep is needed to rest the brain, improve memory, and increase one’s energy. This shows that Islam places great importance on having productivity and alertness in each individual’s deed. Many scientific facts that had been clearly stated in a fundamental manner in the Quran could only be analysed with the advanced technology of the 20th century. These facts were not known when they were first revealed and are proof that the Quran is the book of Allah Almighty. The view of Islam on the sleep phenomenon is in line with and is according to the findings of contemporary scien
Development of Spectral Delayed Luminescence System for Whole Saliva Analysis: A Prototype Study
Authors: Jamaludin Mohd Najeb , Balakrishnan Malarvili
Published: March 2014

This paperwork presents the development of spectral delayed luminescence system for the measurement of whole saliva. Despite various reports of delayed luminescence and its correlation to various diseases, it has fail to highlight the specific cause of the occurrence suggesting it being more suitable as a screening tool utilizing saliva as non-invasive sampling medium. Therefore it is the aim of this paper to have the system critical performance tested before putting it to use at the field. The system prototype is tested for its response during room temperature operation and during spot cooling of the photomultiplier tube module. Delayed luminescence of saliva is compared over distilled water as a control. The spectral delayed luminescence of saliva is compared to that of the dimmed white light for functional testing purposes. Through experiments, the best operation for the system is at constant room temperature with light stimulation time determined at 150 ms. Being 98% water, the delayed luminescence of saliva is slightly greater than that of distilled water. Given light stimulation of wide spectrum from white LED, the delayed luminescence of saliva is accumulated between 495 nm and 530 nm. Results demonstrated that the system for spectral delayed luminescence of saliva is viable and capable for acquiring data for further studies.
Short‐term sustained hypoxia induces changes in the coupling of sympathetic and respiratory activities in rats
Authors: Moraes Davi J. A. , Bonagamba Leni G. H. , Costa Kauê M. , Costa‐Silva João H. , Zoccal Daniel B. , Machado Benedito H.
Published: March 2014

Key points

Hypoxia activates peripheral chemoreceptors producing an increase in breathing and arterial pressure.

In conditions of sustained hypoxia, an increase in ventilation and arterial blood pressure is observed that persists after the return to normoxia.

We show in rats that sustained hypoxia for 24 h produces glutamate‐dependent changes in the activity of expiratory and sympathetic neurones of the rostral ventrolateral medulla, which are essential for the control of respiratory and sympathetic activities.

These neuronal changes induced by sustained hypoxia are critical for the emergence of coupled active expiration and augmented sympathetic activity.

These findings contribute to a better understanding of cardiorespiratory adjustments associated with sustained hypoxia in individuals experiencing high altitudes.

Individuals experiencing sustained hypoxia (SH) exhibit adjustments in the respiratory and autonomic functions by neural mechanisms not yet elucidated. In the present study we evaluated the central mechanisms underpinning the SH‐induced changes in the respiratory pattern and their impact on the sympathetic outflow. Using a decerebrated arterially perfused in situ preparation, we verified that juvenile rats exposed to SH (10% O2) for 24 h presented an active expiratory pattern, with increased abdominal, hypoglossal and vagal activities during late‐expiration (late‐E). SH also enhanced the activity of augmenting‐expiratory neurones and depressed the activity of post‐inspiratory neurones of the Bötzinger complex (BötC) by mechanisms not related to changes in their intrinsic electrophysiological properties. SH rats exhibited high thoracic sympathetic activity and arterial pressure levels associated with an augmented firing frequency of pre‐sympathetic neurones of the rostral ventrolateral medulla (RVLM) during the late‐E phase. The antagonism of ionotropic glutamatergic receptors in the BötC/RVLM abolished the late‐E bursts in expiratory and sympathetic outputs of SH rats, indicating that glutamatergic inputs to the BötC/RVLM are essential for the changes in the expiratory and sympathetic coupling observed in SH rats. We also observed that the usually silent late‐E neurones of the retrotrapezoid nucleus/parafacial respiratory group became active in SH rats, suggesting that this neuronal population may provide the excitatory drive essential to the emergence of active expiration and sympathetic overactivity. We conclude that short‐term SH induces the activation of medullary expiratory neurones, which affects the pattern of expiratory motor activity and its coupling with sympathetic activity.
Greater excitability and firing irregularity of tufted cells underlies distinct afferent‐evoked activity of olfactory bulb mitral and tufted cells
Authors: Burton Shawn D. , Urban Nathaniel N.
Published: March 2014

Key points

The two classes of principal neurons in the mammalian main olfactory bulb, mitral and tufted cells, respond with different firing latencies and rates to afferent‐evoked input; how these differences in activity arise is incompletely understood.

Tufted cells receive stronger afferent‐evoked excitation than mitral cells, but this difference alone is insufficient to account for the greater afferent‐evoked firing in tufted versus mitral cells.

Mitral and tufted cells exhibit significant intrinsic functional differences; compared to mitral cells, tufted cells fire action potentials with shorter durations and faster afterhyperpolarizations and exhibit twofold greater firing rate–current curve gains and peak rates.

Tufted cells exhibit diverse firing modes, including tonic firing and irregular stuttering, and on average fire more irregularly than mitral cells.

Collectively, stronger afferent excitation, greater intrinsic excitability and more irregular firing in tufted cells combine to drive distinct responses of mitral and tufted cells to sensory input.

Mitral and tufted cells, the two classes of principal neurons in the mammalian main olfactory bulb, exhibit morphological differences but remain widely viewed as functionally equivalent. Results from several recent studies, however, suggest that these two cell classes may encode complementary olfactory information in their distinct patterns of afferent‐evoked activity. To understand how these differences in activity arise, we have performed the first systematic comparison of synaptic and intrinsic properties between mitral and tufted cells. Consistent with previous studies, we found that tufted cells fire with higher probability and rates and shorter latencies than mitral cells in response to physiological afferent stimulation. This stronger response of tufted cells could be partially attributed to synaptic differences, as tufted cells received stronger afferent‐evoked excitation than mitral cells. However, differences in intrinsic excitability also contributed to the differences between mitral and tufted cell activity. Compared to mitral cells, tufted cells exhibited twofold greater excitability and peak instantaneous firing rates. These differences in excitability probably arise from differential expression of voltage‐gated potassium currents, as tufted cells exhibited faster action potential repolarization and afterhyperpolarizations than mitral cells. Surprisingly, mitral and tufted cells also showed firing mode differences. While both cell classes exhibited regular firing and irregular stuttering of action potential clusters, tufted cells demonstrated a greater propensity to stutter than mitral cells. Collectively, stronger afferent‐evoked excitation, greater intrinsic excitability and more irregular firing in tufted cells can combine to drive distinct responses of mitral and tufted cells to afferent‐evoked input.
Neuro‐humoral signalling by bile acids and the TGR5 receptor in the gastrointestinal tract
Authors: Bunnett Nigel W.
Published: March 2014

In addition to their role in the digestion and absorption of dietary fats, bile acids (BAs) are tightly regulated signalling molecules. Their levels in the intestinal lumen, circulation and tissues fluctuate after feeding and fasting, and as a result of certain diseases and therapies. BAs regulate many cell types in the gut wall and beyond by activating nuclear and plasma membrane receptors. Of these, the G protein‐coupled receptor TGR5 has emerged as a key mediator of the non‐genomic actions of BAs. TGR5 is a cell‐surface receptor that couples to Gαs, formation of cAMP, activation of protein kinase A and extracellular signal‐regulated kinases, and inhibition of inflammatory signalling pathways. TGR5 has been implicated in mediating the actions of BAs on secretion of glucagon‐like peptide 1 and glucose homeostasis, gastrointestinal motility and transit, electrolyte and fluid transport in the colon, bile formation and secretion, sensory transduction and inflammation. TGR5 agonists have been developed as treatments for metabolic, inflammatory and digestive disorders, and emerging evidence suggests that TGR5 mutations are associated with inflammatory diseases. Thus, TGR5 plays an important role in the normal processes of digestion and is a new therapeutic target for important digestive diseases.
Focused helium and neon ion beam induced etching for advanced extreme ultraviolet lithography mask repair
Authors: Gonzalez Carlos M. , Timilsina Rajendra , Li Guoliang , Duscher Gerd , Rack Philip D. , Slingenbergh Winand , van Dorp Willem F. , De Hosson Jeff T. M. , Klein Kate L. , Wu Huimeng M. , Stern Lewis A.
Published: March 2014

The gas field ion microscope was used to investigate helium and neon ion beam induced etching of nickel as a candidate technique for extreme ultraviolet (EUV) lithography mask editing. No discernable nickel etching was observed for room temperature helium exposures at 16 and 30 keV in the dose range of 1 × 1015–1 × 1018 He+/cm2; however, transmission electron microscopy (TEM) revealed subsurface damage to the underlying Mo-Si multilayer EUV mirror. Subsequently, neon beam induced etching at 30 keV was investigated over a similar dose range and successfully removed the entire 50 nm nickel top absorber film at a dose of ∼3 × 1017 Ne+/cm2. Similarly, TEM revealed subsurface damage in the underlying Mo-Si multilayer. To further understand the helium and neon damage, the authors simulated the ion–solid interactions with our EnvizION Monte-Carlo model, which reasonably correlated the observed damage and bubble formation to the nuclear energy loss and the implanted inert gas concentration, respectively. A critical nuclear energy density loss of ∼80 eV/nm3 and critical implant concentration of ∼2.5 × 1020 atoms/cm3 have been estimated for damage generation in the multilayer structure.
Phase formation and morphological stability of ultrathin Ni-Co-Pt silicide films formed on Si(100)
Authors: Xu Peng , Kubart Tomas , Gao Xindong , Wu Dongping , Zhang Shi-Li
Published: March 2014

Ultrathin Ni, Co, and Pt films, each no more than 4 nm in thickness, as well as their various combinations are employed to investigate the competing growth of epitaxial Co1-yNiySi2 films against polycrystalline Pt1-zNizSi. The phase formation critically affects the morphological stability of the resulting silicide films, with the epitaxial films being superior to the polycrystalline ones. Any combination of those metals improves the morphological stability with reference to their parent individual metal silicide films. When Ni, Co, and Pt are all included, the precise initial location of Pt does little to affect the final phase formation in the silicide films and the epitaxial growth of Co1-xNixSi2 films is always perturbed, in accordance to thermodynamics that shows a preferential formation of Pt1-zNizSi over that of Co1-yNiySi2.
A Comparison of Capillary, Venous, and Salivary Cortisol Sampling after Intense Exercise
Authors: Fryer Simon , Dickson Tabitha , Hillier Stephen , Stoner Lee , Scarrott Carl , Draper Nick
Published: March 2014

Venipuncture is expensive, invasive, and impractical for many sport-science and clinical-based settings. Salivary free cortisol is often cited as a noninvasive practical alternative. However, when cortisol concentrations exceed the corticosteroid-binding globulin (CBG) point of 500 nmol/L, a lack of agreement between salivary and venous blood cortisol has been found. Alternatively, capillary blood may present a minimally invasive, cost-effective, and practical surrogate for determining cortisol concentration.

Purpose:

The aim of this study was to determine whether cortisol concentrations sampled from capillary blood and saliva accurately reflect those found in venous blood across a large range of concentrations after intense exercise.

Methods:

Eleven healthy aerobically trained male subjects were recruited. Capillary, salivary, and venous blood samples were collected before and after (immediately and 5, 10, 15, and 20 min after) a treadmill VO2 maxtest.

Results:

Capillary and venous concentrations increased at a similar rate after exercise (Cohend.14–.33), increasing up to 15 min postexercise before a decline was seen. Salivary cortisol values increased at a slower rate than venous and capillary cortisol but continued to increase 15 min postexercise (Cohend.19–.47 and .09–.72, respectively).

Conclusions:

Capillary cortisol accurately reflects concentrations assayed from venous blood across a range of values below and above the CBG binding point. Capillary sampling provides a minimally invasive, cost-effective, practical surrogate for assessment of hypothalamic-pituitary-gland function.
The Effect of Short-Term Interval Training during the Competitive Season on Physical Fitness and Signs of Fatigue: A Crossover Trial in High-Level Youth Football Players
Authors: Faude Oliver , Steffen Anke , Kellmann Michael , Meyer Tim
Published: March 2014

Purpose:

To analyze performance and fatigue effects of small-sided games (SSG) vs high-intensity interval training (HIIT) performed during a 4-wk in-season period in high-level youth football.

Methods:

Nineteen players from 4 youth teams (16.5 [SD 0.8] y, 1.79 [0.06] m, 70.7 [5.6] kg) of the 2 highest German divisions completed the study. Teams were randomly assigned to 1 of 2 training sequences (2 endurance sessions per wk): One training group started with SSG, whereas the other group conducted HIIT during the first half of the competitive season. After the winter break, training programs were changed between groups. Before and after the training periods the following tests were completed: the Recovery-Stress Questionnaire for Athletes, creatine kinase and urea concentrations, vertical-jump height (countermovement jump [CMJ], drop jump), straight sprint, agility, and an incremental field test to determine individual anaerobic threshold (IAT).

Results:

Significant time effects were observed for IAT (+1.3%, ηp2 = .31), peak heart rate (–1.8%, ηp2 = .45), and CMJ (–2.3%, ηp2 = .27), with no significant interaction between groups (P > .30). Players with low baseline IAT values (+4.3%) showed greater improvements than those with high initial values (±0.0%). A significant decrease was found for total recovery (–5.0%, ηp2 = .29), and an increase was found for urea concentration (+9.2%, ηp2 = .44).

Conclusion:

Four weeks of in-season endurance training can lead to relevant improvements in endurance capacity. The decreases in CMJ height and total-recovery score together with the increase in urea concentration might be interpreted as early signs of fatigue. Thus, the danger of overtaxing players should be considered.
Intra- and Interdimeric Caspase-8 Self-Cleavage Controls Strength and Timing of CD95-Induced Apoptosis
Authors: Kallenberger Stefan M. , Beaudouin Joël , Claus Juliane , Fischer Carmen , Sorger Peter K. , Legewie Stefan , Eils Roland
Published: March 2014

Dual modes of activation of caspase-8 enable precise control of apoptosis.
YAP Inhibits MicroRNA Processing
Authors: Berndt Jason D.
Published: March 2014

High cell density decreases microRNA abundance by inhibiting Hippo signaling.
MIV-150-Containing Intravaginal Rings Protect Macaque Vaginal Explants against SHIV-RT Infection
Authors: Ouattara Louise A. , Barnable Patrick , Mawson Paul , Seidor Samantha , Zydowsky Thomas M. , Kizima Larisa , Rodriguez Aixa , Fernández-Romero José A. , Cooney Michael L. , Roberts Kevin D. , Gettie Agegnehu , Blanchard James , Robbiani Melissa , Teleshova Natalia
Published: March 2014

Recent studies demonstrated that intravaginal rings (IVRs) containing 100 mg of the nonnucleoside reverse transcriptase inhibitor (NNRTI) MIV-150 significantly protect macaques against a chimeric simian-human immunodeficiency virus that expresses the HIV-1 HxB2 reverse transcriptase (SHIV-RT) when present before and after vaginal challenge. The objectives of this study were to (i) evaluate the pharmacodynamics (PD) of MIV-150 in vaginal fluids (VF) and in ectocervical and vaginal tissues following 100-mg MIV-150 IVR exposure and to (ii) gain more insight whether pharmacokinetics (PK) of MIV-150 can predict PD. MIV-150 in VF collected at 1 day and 14 days post-MIV-150 IVR insertion inhibited
ex vivo
SHIV-RT infection in vaginal biopsy specimens from untreated animals (not carrying IVRs) in a dose-dependent manner. Previous PK studies demonstrated a significant increase of ectocervical and vaginal tissue MIV-150 concentrations 14 days versus 1 day post-IVR insertion, with the highest increase in vaginal tissue. Therefore, we tested PD of MIV-150 in tissues 14 days post-MIV-150 IVR insertion.
Ex vivo
SHIV-RT infection of vaginal, but not ectocervical, tissues collected 14 days post-MIV-150 IVR insertion was significantly inhibited compared to infection at the baseline (prior to MIV-150 IVR exposure). No changes in vaginal and ectocervical tissue infection were observed after placebo IVR exposure. Overall, these data underscore the use of the
ex vivo
macaque explant challenge models to evaluate tissue and VF PK/PD of candidate microbicides before
in vivo
animal efficacy studies. The data support further development of MIV-150-containing IVRs.
Pharmacodynamics of Cefquinome in a Neutropenic Mouse Thigh Model of Staphylococcus aureus Infection
Authors: Wang Jing , Shan Qi , Ding Huanzhong , Liang Chaoping , Zeng Zhenling
Published: March 2014

Cefquinome is a cephalosporin with broad-spectrum antibacterial activity, including activity against
Staphylococcus aureus
. The objective of our study was to examine the
in vivo
activity of cefquinome against
S. aureus
strains by using a neutropenic mouse thigh infection model. Cefquinome kinetics and protein binding in infected neutropenic mice were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS).
In vivo
postantibiotic effects (PAEs) were determined after a dose of 100 mg/kg of body weight in mice infected with
S. aureus
strain ATCC 29213. The animals were treated by subcutaneous injection of cefquinome at doses of 2.5 to 320 mg/kg of body weight per day divided into 1, 2, 3, 6, or 12 doses over 24 h. Cefquinome exhibited time-dependent killing and produced
in vivo
PAEs at 2.9 h. The percentage of time that serum concentrations were above the MIC (%
T
>MIC
) was the pharmacokinetic-pharmacodynamic (PK-PD) index that best described the efficacy of cefquinome. Subsequently, we employed a similar dosing strategy by using increasing total cefquinome doses that increased 4-fold and were administered every 4 h to treat animals infected with six additional
S. aureus
isolates. A sigmoid maximum effect (
E
max
) model was used to estimate the magnitudes of the ratios of the %
T
that the free-drug serum concentration exceeded the MIC (%
T

>
f
MIC

) associated with net bacterial stasis, a 0.5-log
10
CFU reduction from baseline, and a 1-log
10
CFU reduction from baseline; the respective values were 30.28 to 36.84%, 34.38 to 46.70%, and 43.50 to 54.01%. The clear PAEs and potent bactericidal activity make cefquinome an attractive option for the treatment of infections caused by
S. aureus
.
Energy Metabolism and Drug Efflux in Mycobacterium tuberculosis
Authors: Black Philippa A. , Warren Robin M. , Louw Gail E. , van Helden Paul D. , Victor Thomas C. , Kana Bavesh D.
Published: March 2014

The inherent drug susceptibility of microorganisms is determined by multiple factors, including growth state, the rate of drug diffusion into and out of the cell, and the intrinsic vulnerability of drug targets with regard to the corresponding antimicrobial agent.Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), remains a significant source of global morbidity and mortality, further exacerbated by its ability to readily evolve drug resistance. It is well accepted that drug resistance inM. tuberculosisis driven by the acquisition of chromosomal mutations in genes encoding drug targets/promoter regions; however, a comprehensive description of the molecular mechanisms that fuel drug resistance in the clinical setting is currently lacking. In this context, there is a growing body of evidence suggesting that active extrusion of drugs from the cell is critical for drug tolerance.M. tuberculosisencodes representatives of a diverse range of multidrug transporters, many of which are dependent on the proton motive force (PMF) or the availability of ATP. This suggests that energy metabolism and ATP production through the PMF, which is established by the electron transport chain (ETC), are critical in determining the drug susceptibility ofM. tuberculosis. In this review, we detail advances in the study of the mycobacterial ETC and highlight drugs that target various components of the ETC. We provide an overview of some of the efflux pumps present inM. tuberculosisand their association, if any, with drug transport and concomitant effects on drug resistance. The implications of inhibiting drug extrusion, through the use of efflux pump inhibitors, are also discussed.
How To Minimize Toxic Exposure to Pyridine during Continuous Infusion of Ceftazidime in Patients with Cystic Fibrosis?
Authors: Bourget P. , Amin A. , Dupont C. , Abely M. , Desmazes-Dufeu N. , Dubus J. C. , Jouani B.-L. , Merlette C. , Nové-Josserand R. , Pages J. , Panzo R. , Vidal F. , Voge F. , Hubert D.
Published: March 2014

Ceftazidime is particularly efficient against
Pseudomonas aeruginosa
in cystic fibrosis patients. Thus, the spontaneous production of pyridine, which is a toxic product, raises some concern. Our aim was to examine the kinetics of degradation of ceftazidime in portable infusion pumps either at 4°C, 22°C, or 33°C and to propose some recommendations in order to reduce the pyridine exposure. Two administration models were studied
in vitro
. In model 1, we administered 12 g of ceftazidime infused over 23 h (once-daily infusion) compared to 6 g infused over 11.5 h in model 2 (twice-daily regimen). Samples were collected at 0 h and then every 4 and 2 h after the shaping of portable infusion pumps in models 1 and 2, respectively. Both ceftazidime and pyridine were analyzed using an ultraviolet high-performance liquid chromatograph. Production of pyridine is highly depending on the temperature. The
in situ
production of pyridine per day of treatment decreases at a ratio close to 1/6 and 1/3 between 33°C and 4°C in models 1 and 2, respectively. Regardless of the conditions, the production of pyridine is significantly lower in model 2, whereas the total delivery amount of ceftazidime is significantly higher at 4°C and 33°C compared to that in model 1. According to a the precautionary principle, these findings lead to three major recommendations: (i) exposing a solution of ceftazidime to over 22°C should be strictly avoided, (ii) a divided dose of 6 g over 11.5 h instead of a once-daily administration is preferred, and (iii) infusion should be administered immediately after reconstitution.
Cytokine/Chemokine Secretion and Proteomic Identification of Upregulated Annexin A1 from Peripheral Blood Mononuclear Cells Cocultured with the Liver Fluke Opisthorchis viverrini
Authors: Hongsrichan Nuttanan , Intuyod Kitti , Pinlaor Porntip , Khoontawad Jarinya , Yongvanit Puangrat , Wongkham Chaisiri , Roytrakul Sittiruk , Pinlaor Somchai
Published: March 2014

We investigated the cytokine/chemokine secretions and alteration of protein expression from peripheral blood mononuclear cells (PBMCs) cocultured with adult liver flukes (Opisthorchis viverrini) for 6 to 24 h. PBMC-derived proteins were identified by two-dimensional electrophoresis and mass spectrometry, and the cytokines/chemokines in the supernatant were assessed using a cytokine array. Exposure toO. viverriniinduced increases in secretion of proinflammatory cytokines, costimulating protein, adhesion molecules, and chemotactic chemokines relative to untreated controls. In contrast, secretion of the CD40 ligand, interleukin 16, and macrophage inflammatory protein 1β decreased. Proteomic analysis revealed that expression of 48 proteins was significantly altered in PBMCs stimulated withO. viverrini. Annexin A1 (ANXA1) was selected for further study, and immunoblotting showed upregulation of ANXA1 expression in PBMCs after 12 and 24 h coculture with liver flukes. In anin vivostudy, transcription and translation of ANXA1 significantly increased in livers of hamsters infected withO. viverriniat 21 days and from 3 months onwards compared to normal controls. Interestingly, immunohistochemistry revealed that ANXA1 was present not only in the cytoplasm of inflammatory cells but also in the cytoplasm of cholangiocytes, which are in close contact with the parasite and its excretory/secretory products in the biliary system. Expression of ANXA1 increased with time concomitant with bile duct enlargement, bile duct formation, and epithelial cell proliferation. In conclusion, several cytokines/chemokines secreted by PBMCs and upregulation of ANXA1 in PBMCs and biliary epithelial cells might have a role in host defense againstO. viverriniinfection and tissue resolution of inflammation.
Live Attenuated Mutants of Francisella tularensis Protect Rabbits against Aerosol Challenge with a Virulent Type A Strain
Authors: Reed Douglas S. , Smith Le'Kneitah P. , Cole Kelly Stefano , Santiago Araceli E. , Mann Barbara J. , Barry Eileen M.
Published: March 2014

Francisella tularensis, a Gram-negative bacterium, is the causative agent of tularemia. No licensed vaccine is currently available for protection against tularemia, although an attenuated strain, dubbed the live vaccine strain (LVS), is given to at-risk laboratory personnel as an investigational new drug (IND). In an effort to develop a vaccine that offers better protection, recombinant attenuated derivatives of a virulent type A strain, SCHU S4, were evaluated in New Zealand White (NZW) rabbits. Rabbits vaccinated via scarification with the three attenuated derivatives (SCHU S4 ΔguaBA, ΔaroD, and ΔfipBstrains) or with LVS developed a mild fever, but no weight loss was detected. Twenty-one days after vaccination, all vaccinated rabbits were seropositive for IgG toF. tularensislipopolysaccharide (LPS). Thirty days after vaccination, all rabbits were challenged with aerosolized SCHU S4 at doses ranging from 50 to 500 50% lethal doses (LD50). All rabbits developed fevers and weight loss after challenge, but the severity was greater for mock-vaccinated rabbits. The ΔguaBAand ΔaroDSCHU S4 derivatives provided partial protection against death (27 to 36%) and a prolonged time to death compared to results for the mock-vaccinated group. In contrast, LVS and the ΔfipBstrain both prolonged the time to death, but there were no survivors from the challenge. This is the first demonstration of vaccine efficacy against aerosol challenge with virulent type AF. tularensisin a species other than a rodent since the original work with LVS in the 1960s. The ΔguaBAand ΔaroDSCHU S4 derivatives warrant further evaluation and consideration as potential vaccines for tularemia and for identification of immunological correlates of protection.
Ortner's syndrome
Authors: Shahul Hameed Aboobackar , Manu Mohan K , Mohapatra Aswini Kumar , Magazine Rahul
Published: March 2014

A 42-year-old man with a significant smoking history presented with chronic expectorative cough and exertional shortness of breath with recent-onset hoarseness. Chest examination was essentially normal and cardiovascular examination was suggestive of aortic regurgitation. Ears, nose and throat evaluation showed left vocal cord palsy and CT scan revealed an aortic arch aneurysm. Ortner's syndrome refers to hoarseness due to recurrent laryngeal nerve palsy secondary to a cardiovascular abnormality. Aortic aneurysms usually present with chest pain, back pain or epigastric pain, depending on the site of the aneurysm. An aortic arch aneurysm presenting as hoarseness is extremely rare.
Acute kidney injury after massive attack of Africanised bees
Authors: Bridi Ramaiane A , Balbi Andre Luis , Neves Precil M , Ponce Daniela
Published: March 2014

Acute kidney injury (AKI) is a well-documented complication of massive attack by Africanised bees and can be observed 48–72 h after the accident. We report a case of Africanised bees attack followed by severe and lethal AKI. A 56-year-old man was admitted to emergency department after a massive attack of Africanised bees (>1000 bee stings). He was unconscious, presenting with hypotension and tachycardia. Mechanical ventilation, volume expansion and care for anaphylaxis were instituted. The patient was transferred to the intensive care unit (ICU) and after 48 h he developed rhabdomyolysis, oliguria, increased creatinine levels, hyperkalaemia and refractory acidosis. A diagnosis of AKI secondary to rhabdomyolysis and shock was made. The patient was treated with a prolonged course of haemodialysis. However, he progressed to refractory shock and died 5 days after admission.
Cerebellar and oculomotor dysfunction induced by rapid infusion of pethidine
Authors: Dai Yang-Hong , Ou Kuang-Ling , Chu Po-Wei
Published: March 2014

Pethidine is an opioid that gains its popularity for the effective pain control through acting on the opioid-receptors. However, rapid pain relief sometimes brings about unfavourable side effects that largely limit its clinical utility. Common side effects include nausea, vomiting and hypotension. In patients with impaired renal and liver function, and those who need long-term pain control, pethidine may cause excitatory central nervous system (CNS) effects through its neurotoxic metabolite, norpethidine, resulting in irritability and seizure attack. On the contrary, though not clinically apparent, pethidine potentially causes inhibitory impacts on the CNS and impairs normal cerebellar and oculomotor function in the short term. In this case report, we highlight opioid's inhibitory side effects on the cerebellar structure that causes dysmetria, dysarthria, reduced smooth pursuit gain and decreased saccadic velocity.
Acute hamstring injuries in Swedish elite sprinters and jumpers: a prospective randomised controlled clinical trial comparing two rehabilitation protocols
Authors: Askling Carl M , Tengvar Magnus , Tarassova Olga , Thorstensson Alf
Published: March 2014

Background

Hamstring strain is a common injury in sprinters and jumpers, and therefore time to return to sport and secondary prevention become of particular concern.

Objective

To compare the effectiveness of two rehabilitation protocols after acute hamstring injury in Swedish elite sprinters and jumpers by evaluating time needed to return to full participation in the training process.

Study design

Prospective randomised comparison of two rehabilitation protocols.

Methods

Fifty-six Swedish elite sprinters and jumpers with acute hamstring injury, verified by MRI, were randomly assigned to one of two rehabilitation protocols. Twenty-eight athletes were assigned to a protocol emphasising lengthening exercises, L-protocol, and 28 athletes to a protocol consisting of conventional exercises, C-protocol. The outcome measure was the number of days to return to full training. Re-injuries were registered during a period of 12 months after return.

Results

Time to return was significantly shorter for the athletes in the L-protocol, mean 49 days (1SD±26, range 18–107 days), compared with the C-protocol, mean 86 days (1SD±34, range 26–140 days). Irrespective of protocol, hamstring injuries where the proximal free tendon was involved took a significantly longer time to return than injuries that did not involve the free tendon, L-protocol: mean 73 vs 31 days and C-protocol: mean 116 vs 63 days, respectively. Two reinjuries were registered, both in the C-protocol.

Conclusions

A rehabilitation protocol emphasising lengthening type of exercises is more effective than a protocol containing conventional exercises in promoting time to return in Swedish elite sprinters and jumpers.
PREVALENCE OF DIETARY SUPPLEMENT USE AMONG ELITE IRANIAN ATHLETES (MALE & FEMALE NATIONAL LEVEL ATHLETES)
Authors: Golshanraz A , Laleh H , Lotfali P
Published: March 2014

Background

Dietary supplement use is common in athletes. Besides their cost, they may have side effects on health and performance. They may also cause inadvertent doping violation.

Objective

The study aimed to explore the frequency, type, believes, attitudes and knowledge of participants regarding dietary supplements.

Design

KAP analysis, cross sectional, cluster sampling, year 2011.

Setting

Face to face data gathering strategy from national level athletes performed based on valid questionnaire.

Participants

350 national level athletes (mean age 21.87 years) from 26 different sports fields and both sexes.

Risk factor assessment

Age, sex, level of education, sports field, history of sports participation, weight, height, body mass index.

Main Outcome Measurements

Knowledge was good in 36.70%, average in 59.80%, and poor in 3.20% of respondents. 65% of them either did not use any sports supplements at all, or they used less than 2 times weekly. The most widely used supplements were vitamins (m=76.9%, f=77.4%), energy supplements (m=56.9%, f=47.1%), and minerals (m=44.6%, f=57.4%). 72.1% of athletes believed in their efficacy, 40.2% experienced performance enhancement and 11.4% reported side effects. Over 60% rated their knowledge inadequate and 57.5% were eager to learn more.

Conclusions

Many athletes believe in the efficacy of supplements and think they are an unavoidable part of competitive sports. Considering three aspects of supplement consumption –safety, efficacy, legitimacy, it should be focused that "optimal dietary intake is the basics for sport for life". We have to stress on education, consulting sessions, and rational prescription.
THE EFFECT OF REMOVING MAN-MADE JUMPS FROM SNOW-PARKS ON THE RISK OF SEVERE SKI-PATROL REPORTED INJURIES SUSTAINED BY SKIERS AND SNOWBOARDERS
Authors: Goulet C , Hagel B , Hamel D , Tremblay B
Published: March 2014

Background

Evidence indicates that snow-park (SP) injuries are more severe than injuries on regular slopes. This prompted two major ski areas in the province of Québec, Canada, to remove all man-made jumps from their SPs before season 2007–08.

Objective

To determine if removing jumps from SPs reduced the prevalence of severe injuries for skiers and snowboarders.

Design

Retrospective study using ski-patrol Injury Report Forms (IRF). The proportion of severe injuries before (seasons 2000–01 to 2006–07) and after (seasons 2007–08 to 2009–10) SP jump removal was compared with proportions at other areas.

Setting

All ski areas in operation in the province (between 77 and 84).

Participants

Skiers and snowboarders who reported to the ski patrol with a SP injury at two ski areas before and after SP jumps were removed, and for all the ski areas with no SP jump removal.

Risk factor assessment

Risk factor data and injury outcomes were collected through IRFs.

Main outcome measurements

Severe injuries were defined based on type of injury or ambulance evacuation. The proportion of severe injuries before and after SP jump removal was compared with proportions at other areas. Logistic regression analysis was used to adjust the pre- and post change comparison for age, sex, skill level, helmet use, and type of activity.

Results

At the two hills that removed jumps, the proportion of severe injuries was 19.3% (600 severe SP injuries/3,109 all SP injuries) before and 14.5% (63/434) after the change, compared with 23.7% (2 679/11 324) and 22.1% (921/4 173) at other hills. The odds of severe injuries declined at the two areas that removed jumps (adjusted odds ratio [AOR]: 0.72; 95% CI: 0.54–0.97) with no change at other ski areas (AOR: 0.94; 95% CI: 0.83–1.08).

Conclusions

Results suggest that removing man-made jumps from SPs prevents severe injuries.
THE MAIN CAUSES OF INJURIES SUSTAINED AT FITNESS FACILITIES PRESENTING TO VICTORIAN EMERGENCY DEPARTMENTS: IDENTIFYING THE CULPRITS
Authors: Gray S , Finch CF
Published: March 2014

Background

Fitness facilities provide an important avenue for people to increase their physical activity; however they can also be a common context of injury. The only source of routinely collected data about injuries associated with fitness activities is the Victorian Emergency Minimum Dataset as used by the Victorian Injury Surveillance Unit. This includes injury presentations to all public Victorian emergency rooms with a 24-hour service. Each case is accompanied by a 250-character narrative that provides further details surrounding the circumstances of the injury.

Objective

To determine the main causes of injury associated with fitness activities.

Design

Analysis of emergency department case narratives from 2002/03 to 2011/12.

Participants

1 979 de-identified injured persons who presented to included Victorian emergency departments.

Main outcome measurements

Textual analysis and summary of the narratives to identify specific causes of injuries sustained in fitness facilities to lead potential injury prevention efforts.

Results

The leading cause of injury depended on the type of activity being participated in (i.e. resistance training, aerobics/group exercise and use of other equipment). Across all fitness activities, the leading specified cause of injury was hit/struck/crush (50.9%) however this was largely driven by the high proportion of resistance training hit/struck/crush injuries (82.6% of all resistance training injuries). Falls were the leading specified cause of injury for aerobics and other equipment (62.4% and 63.2%, respectively). Most cases were not severe, with only 7.5% subsequently admitted to hospital.

Conclusion:

Injury prevention efforts should be specific to particular activities commonly participated in at fitness facilities, as the specific causes of injuries vary across these.
ISOKINETIC RELATIVE STRENGTH PROFILE OF POLISH ELITE AND SUB-ELITE FEMALE AND MALE SOCCER PLAYERS – A CROSS SECTIONAL STUDY
Authors: Grygorowicz M , Hojszyk R , Piontek T , Dudzinski W
Published: March 2014

Background

However the isokinetic strength is well described in the literature, there is still little know about the relative isokinetic strength values in sub-elite and elite soccer players of both sexes. One has to remember that this value should be regarded as one of critical sport-return criteria in case of the injury.

Objective

To describe distribution of isokinetic relative strength value in Polish elite female and male soccer players. We hypothesize that there will be no differences in relative isokinetic strength between players in different soccer level group.

Design

Cross sectional study.

Setting

Elite and sub-elite division.

Participants

41 young sub-elite (YSMS), 27 elite male (EMS) and 30 elite female soccer (EFS) players from Polish Ekstraklasa and Youth Division.

Interventions

All soccer players performed concentric-concentric knee extension-flexion movements on Biodex System 3 Pro dynamometer at 60°/s of angular isokinetic velocity. Alignment axis of dynamometer rotation, thigh, hip and trunk stabilization as well as gravity correction and the range of motion was then set for each participant according to standard procedures. Values of relative isokinetic strength for were recorded. The one-way ANOVA with post hoc Tukey T test were used to assess differences between three groups. t-Test for two independent samples was used to analyze gender effects. Statistical significance was set at P<.05.

Main outcomes measurements

Relative knee extensors and flexors isokinetic strength (Nm/kg).

Results

EFS had significantly higher results in isokinetic quadriceps and hamstring strength comparing to YSMS (2.64 vs. 2.31; P<.001 and 1.39 vs. 1.27; P=.0207, respectively) and significantly lower results comparing EMS group (2.64 vs. 3.11; P<.0001 and 1.39 vs. 1.78; P<.0001, respectively). However there were no differences between groups regarding sex (P=.8881 for extension and P=.0839 for flexion).

Conclusions

Observed differences may be related to soccer skill level and not gender.