Cardiac evaluation of young athletes: Time for a risk-based approach?

Pre-participation cardiovascular screening (PPCS) is recommended by several scientific and sporting organizations on the premise that early detection of cardiac disease provides a platform for individualized risk assessment and management; which has been proven to lower mortality rates for certain conditions associated with sudden cardiac arrest (SCA) and sudden cardiac death (SCD). What constitutes the most effective strategy for PPCS of young athletes remains a topic of considerable debate. The addition of the electrocardiogram (ECG) to the medical history and physical examination undoubtedly enhances early detection of disease, which meets the primary objective of PPCS. The benefit of enhanced sensitivity must be carefully balanced against the risk of potential harm through increased false-positive findings, costly downstream investigations, and unnecessary restriction/disqualification from competitive sports. To mitigate this risk, it is essential that ECG-based PPCS programs are implemented by institutions with a strong infrastructure and by physicians appropriately trained in modern ECG standards with adequate cardiology resources to guide downstream investigations. While PPCS is compulsory for most competitive athletes, the current debate surrounding ECG-based programs exists in a binary form; whereby ECG screening is mandated for all competitive athletes or none at all. This polarized approach fails to consider individualized patient risk and the available sports cardiology resources. The limitations of a uniform approach are highlighted by evolving data, which suggest that athletes display a differential risk profile for SCA/SCD, which is influenced by age, sex, ethnicity, sporting discipline, and standard of play. Evaluation of the etiology of SCA/SCD within high-risk populations reveals a disproportionately higher prevalence of ECG-detectable conditions. Selective ECG screening using a risk-based approach may, therefore, offer a more cost-effective and feasible approach to PPCS in the setting of limited sports cardiology resources, although this approach is not without important ethical considerations

Capacity loss of non-aqueous Li-Air battery due to insoluble product formation: Approximate solution and experimental validation

In this paper, we present a study of Lithium (Li)-air battery capacity by accounting for the voltage loss associated with the electrode passivation and transport resistance caused by insoluble product formation. Two regimes are defined, in which approximate formulas are developed to explicitly evaluate the battery capacity, along with extensive validation against experimental data of various cathode properties and materials from our and several other groups. The dependence of battery capacity on the surface coverage factor, tortuosity, and Damköhler numbers (Da) is explicitly expressed and discussed. The formulas provide a guideline for experimentalists and practitioners in air cathode design, analysis, and control

Laser Doppler velocimetry for continuous flow solar-pumped iodine laser system

A laser Doppler velocimetry (LDV) system was employed to measure the flow velocity profile of iodide vapor inside laser tubes of 36 mm ID and 20 mm ID. The LDV, which was operated in the forward scatter mode used a low power (15 mW) He-Ne laser beam. Velocity ranges from 1 m/s was measured to within one percent accuracy. The flow velocity profile across the laser tube was measured and the intensity of turbulence was determined. The flow of iodide inside the laser tube demonstrated a mixture of both turbulence and laminar flow. The flowmeter used for the laser system previously was calibrated with the LDV and found to be in good agreement

Management of erectile dysfunction post-radical prostatectomy

© 2015 Saleh et al.Radical prostatectomy is a commonly performed procedure for the treatment of localized prostate cancer. One of the long-term complications is erectile dysfunction. There is little consensus on the optimal management; however, it is agreed that treatment must be prompt to prevent fibrosis and increase oxygenation of penile tissue. It is vital that patient expectations are discussed, a realistic time frame of treatment provided, and treatment started as close to the prostatectomy as possible. Current treatment regimens rely on phosphodiesterase 5 inhibitors as a first-line therapy, with vacuum erection devices and intraurethral suppositories of alprostadil as possible treatment combination options. With nonresponders to these therapies, intracavernosal injections are resorted to. As a final measure, patients undergo the highly invasive penile prosthesis implantation. There is no uniform, objective treatment program for erectile dysfunction post-radical prostatectomy. Management plans are based on poorly conducted and often underpowered studies in combination with physician and patient preferences. They involve the aforementioned drugs and treatment methods in different sequences and doses. Prospective treatments include dietary supplements and gene therapy, which have shown promise with there proposed mechanisms of improving erectile function but are yet to be applied successfully in human patients

A ducted wind turbine simulation model for building simulation

Power production is shifting away from centralized generation plants to production of heat and power at the point of demand. A technology that may play a part in this shift is the ducted wind turbine (DWT). The emergence of small building integrated micro turbines opens up the possibility of utilizing the differential pressures occurring around buildings for local power production. This paper describes work to develop and test a simple mathematical model of a ducted wind turbine and its integration within a building simulation tool. A case study in which the simulation model will be used to analyse of the likely power output from a building incorporating ducted wind turbines within the façade is also presented

Au-SN Flip-Chip Solder Bump for Microelectronic and Optoelectronic Applications

As an alternative to the time-consuming solder pre-forms and pastes currently used, a co-electroplating method of eutectic Au-Sn alloy was used in this study. Using a co-electroplating process, it was possible to plate the Au-Sn solder directly onto a wafer at or near the eutectic composition from a single solution. Two distinct phases, Au5Sn and AuSn, were deposited at a composition of 30at.%Sn. The Au-Sn flip-chip joints were formed at 300 and 400 degrees without using any flux. In the case where the samples were reflowed at 300 degrees, only an (Au,Ni)3Sn2 IMC layer formed at the interface between the Au-Sn solder and Ni UBM. On the other hand, two IMC layers, (Au,Ni)3Sn2 and (Au,Ni)3Sn, were found at the interfaces of the samples reflowed at 400 degrees. As the reflow time increased, the thickness of the (Au,Ni)3Sn2 and (Au,Ni)3Sn IMC layers formed at the interface increased and the eutectic lamellae in the bulk solder coarsened.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

Genetic and physical mapping of DNA replication origins in Haloferax volcanii

The halophilic archaeon Haloferax volcanii has a multireplicon genome, consisting of a main chromosome, three secondary chromosomes, and a plasmid. Genes for the initiator protein Cdc6/Orc1, which are commonly located adjacent to archaeal origins of DNA replication, are found on all replicons except plasmid pHV2. However, prediction of DNA replication origins in H. volcanii is complicated by the fact that this species has no less than 14 cdc6/orc1 genes. We have used a combination of genetic, biochemical, and bioinformatic approaches to map DNA replication origins in H. volcanii. Five autonomously replicating sequences were found adjacent to cdc6/orc1 genes and replication initiation point mapping was used to confirm that these sequences function as bidirectional DNA replication origins in vivo. Pulsed field gel analyses revealed that cdc6/orc1-associated replication origins are distributed not only on the main chromosome (2.9 Mb) but also on pHV1 (86 kb), pHV3 (442 kb), and pHV4 (690 kb) replicons. Gene inactivation studies indicate that linkage of the initiator gene to the origin is not required for replication initiation, and genetic tests with autonomously replicating plasmids suggest that the origin located on pHV1 and pHV4 may be dominant to the principal chromosomal origin. The replication origins we have identified appear to show a functional hierarchy or differential usage, which might reflect the different replication requirements of their respective chromosomes. We propose that duplication of H. volcanii replication origins was a prerequisite for the multireplicon structure of this genome, and that this might provide a means for chromosome-specific replication control under certain growth conditions. Our observations also suggest that H. volcanii is an ideal organism for studying how replication of four replicons is regulated in the context of the archaeal cell cycle. © 2007 Norais et al

Metallopanstimulin as a marker for head and neck cancer

BACKGROUND: Metallopanstimulin (MPS-1) is a ribosomal protein that is found in elevated amounts in the sera of patients with head and neck squamous cell carcinoma (HNSCC). We used a test, denoted MPS-H, which detects MPS-1 and MPS-1-like proteins, to determine the relationship between MPS-H serum levels and clinical status of patients with, or at risk for, HNSCC. PATIENTS AND METHODS: A total of 125 patients were prospectively enrolled from a university head and neck oncology clinic. Participants included only newly diagnosed HNSCC patients. Two control groups, including 25 non-smokers and 64 smokers, were studied for comparison. A total of 821 serum samples collected over a twenty-four month period were analyzed by the MPS-H radioimmunoassay. RESULTS: HNSCC, non-smokers, and smokers had average MPS-H values of 41.5 ng/mL, 10.2 ng/mL, and 12.8 ng/mL, respectively (p = 0.0001). CONCLUSION: We conclude that MPS-1 and MPS-1-like proteins are elevated in patients with HNSCC, and that MPS-H appears to be a promising marker of presence of disease and response to treatment in HNSCC patients

An acidic fibroblast growth factor protein generated by alternate splicing acts like an antagonist.

Polymerase chain reaction amplification of cDNA for acidic fibroblast growth factor in several lines of cultured human cells revealed two forms of mRNA. The novel smaller mRNA lacks the entire second coding exon of the acidic fibroblast growth factor gene, whereas the previously identified mRNA consists of three coding exons. The truncated variant of acidic fibroblast growth factor (aFGF') is only 60 amino acids long with an apparent molecular mass of 6.7 kD on sodium dodecyl sulfate gels in contrast to 18 kD for the full-length acidic fibroblast growth factor. aFGF' elicits only minimal fibroblast proliferation and antagonizes the effects of acidic fibroblast growth factor when added exogenously to or when coexpressed with aFGF in BALB/c/3T3 fibroblasts. Thus, the truncated variant of acidic fibroblast growth factor may provide fibroblasts with a unique mechanism for endogenous regulation of their responses to acidic fibroblast growth factor