‘Testosterone Boosting’ Supplements Composition and Claims Are not Supported by the Academic Literature

Chase G. Clemesha,Hatim Thaker,Mary K. Samplaski 대한남성과학회 2020 The World Journal of Men's Health Vol.38 No.1

Purpose: Men take testosterone (T) boosting supplements to naturally improve T levels. We evaluated the composition and advertised claims of “T boosting” supplements, and supporting published evidence. Materials and Methods: Fifty “T booster” supplements were evaluated for active ingredients and product claims, discovered via Google search. PubMed was reviewed for any literature supporting the claims, followed by review of Recommended Daily Allowance (RDA) and upper tolerable intake level (UL) for each component. Results: Ninety percent of supplements claimed to “boost T”, 50% “improve libido”, and 48% “feel stronger”. One-hundred nine unique components were found, with a mean number of 8.3 per product. On PubMed, 24.8% of supplements had data showing an increase in T with supplementation, 10.1% had data showing a decrease in T, and 18.3% had data showing no change in T. No data were found on 61.5% of supplements on their effect on T. Supplements contained a median 1,291% of the RDA for vitamin B12, 807.6% for vitamin B6, 272% of zinc, 200% of vitamin B5, and 187.5% of vitamin B3. Thirteen products exceeded the US Food and Drug Administration UL of ingredients (zinc, vitamin B3, and magnesium). Conclusions: Ninety percent of “T booster” supplements claimed to boost T. However, only 24.8% of these had data to support these claims. A total of 10.1% contained components with data suggesting a negative effect on T. Many had supra-therapeutic doses of vitamins and minerals, occasionally over the UL. Patients should be informed that “T booster” supplements may not have ingredients to support their claims.

Nonlinear spectral design analysis of a structure for hybrid self-centring device enabled structures

Farzin G. Golzar,Geoffrey W. Rodgers,J. Geoffrey Chase 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.61 No.6

Seismic dissipation devices can play a crucial role in mitigating earthquake damages, loss of life and post-event repair and downtime costs. This research investigates the use of ring springs with high-force-to-volume (HF2V) dissipaters to create damage-free, recentring connections and structures. HF2V devices are passive rate-dependent extrusion-based devices with high energy absorption characteristics. Ring springs are passive energy dissipation devices with high self-centring capability to reduce the residual displacements. Dynamic behaviour of a system with nonlinear structural stiffness and supplemental hybrid damping via HF2V devices and ring spring dampers is used to investigate the design space and potential. HF2V devices are modelled with design forces equal to 5% and 10% of seismic weight and ring springs are modelled with loading stiffness values of 20% and 40% of initial structural stiffness and respective unloading stiffness of 7% and 14% of structural stiffness (equivalent to 35% of their loading stiffness). Using a suite of 20 design level earthquake ground motions, nonlinear response spectra for 8 different configurations are generated. Results show up to 50% reduction in peak displacements and greater than 80% reduction in residual displacements of augmented structure compared to the baseline structure. These gains come at a cost of a significant rise in the base shear values up to 200% mainly as a result of the force contributed by the supplemental devices.

논문 : 노외기계시스템공학 ; 코어샘플을 이용한 질소 등 토양성분 현장 측정방법의 비교평가

권기영 ( G. Kweon ),( Eric Lund ),( Chase Maxton ),( Dreiling Kenton ) 한국농업기계학회 2011 바이오시스템공학 Vol.36 No.2

Several methods of in-field measurements of Nitrogen and other soil properties using cores extracted by a hydraulic soil sampler were evaluated. A prototype core scanner was built to accommodate Veris Technologies commercial Vis-NIRS equipment. The testing result for pH, P and Mg were close to RPD (Ratio of Prediction to Deviation=Standard deviation/RMSE) of 2, however the scanner could not achieve the goal of RPD of 2 on some other properties, especially on nitrate nitrogen (NO3) and potassium (K). In situ NIRS/EC probe showed similar results to the core scanner; pH, P and Mg were close to RPD of 2, while NO3 and K were RPD of 1.5 and 1.2, respectively. Correlations between estimations using the probe and the core scanner were strong, with r2>0.7 for P, Mg, Total N, Total C and CEC. Preliminary results for mid-IR spectroscopy showed an r2 of 0.068 and an RMSE for nitrate (N) of 18ppm, even after the removal of calcareous samples and possible N outlier. After removal of calcareous samples on a larger sample set, results improved considerably with an r2 of 0.64 and RMSE of 6 ppm. However, this was only possible after carbonate samples were detected and eliminated, which would not be feasible under in-field measurements. Testing of NO3 and K ion-selective electrodes (ISEs) revealed promising results, with acceptable errors measuring soil solutions containing nitrate and potassium levels that are typical of production agriculture fields.

정보처리 및 복합기술 ; 프로브형 가시광-근적외선 센서를 이용한 토양의 탄소량 측정

권기영 ( G. Y. Kweon ),Eric Lund,Chase Maxton,Paul Drummond,Kyle Jensen 한국농업기계학회 2009 바이오시스템공학 Vol.34 No.5

Delayed surgical repair of the deltoid following acromioplasty: a case report

Zohaib Sherwani,Chase Kelley,Hassan Farooq,Nickolas G. Garbis 대한견주관절의학회 2022 대한견주관절의학회지 Vol.25 No.4

Currently, the literature contains few studies that describe any potential complications following arthroscopic acromioplasty. Because part of the anterior deltoid originates from the anterior acromion, there is a risk for violation and subsequent iatrogenic rupture or avulsion during this procedure. This type of injury can be a devastating problem for patients that may lead to poor function and debilitating pain. We present a patient with deltoid insufficiency following arthroscopic acromioplasty who elected to proceed with operative management with a planned arthroscopic evaluation of the shoulder followed by an open deltoid repair. At the final follow-up visit 2.5 years postoperatively, the patient reported improved pain from baseline and no residual disability and was able to perform most activities of daily living without difficulty. This case serves as an example of a surgical repair for a deltoid avulsion following arthroscopic acromioplasty. As there is still a lack of standard guidelines, our suture repair technique can be considered one method of treatment for this type of injury.

Mechanical properties of titania nanofiber mats fabricated by electrospinning of sol-gel precursor

Park, Soo-Jin,Chase, George G.,Jeong, Kwang-Un,Kim, Hak Yong Springer-Verlag 2010 Journal of sol-gel science and technology Vol.54 No.2

Structural health monitoring for pinching structures via hysteretic mechanics models

Mohammad Rabiepour,Cong Zhou,James G. Chase,Geoffrey W. Rodgers,Chao Xu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.2

Many Structural Health Monitoring (SHM) methods have been proposed for structural damage diagnosis and prognosis. However, SHM for pinched hysteretic structures can be problematic due to the high level of nonlinearity. The model-free hysteresis loop analysis (HLA) has displayed notable robustness and accuracy in identifying damage for full-scaled and scaled test buildings. In this paper, the performance of HLA is compared with seven other SHM methods in identifying lateral elastic stiffness for a six-story numerical building with highly nonlinear pinching behavior. Two successive earthquakes are employed to compare the accuracy and consistency of methods within and between events. Robustness is assessed across sampling rates 50-1000 Hz in noise-free condition and then assessed with 10% root mean square (RMS) noise added to responses at 250 Hz sampling rate. Results confirm HLA is the most robust method to sampling rate and noise. HLA preserves high accuracy even when the sampling rate drops to 50 Hz, where the performance of other methods deteriorates considerably. In noisy conditions, the maximum absolute estimation error is less than 4% for HLA. The overall results show HLA has high robustness and accuracy for an extremely nonlinear, but realistic case compared to a range of leading and recent model-based and model-free methods.

Effect of aluminum oxide doping on the structural, electrical, and optical properties of zinc oxide (AOZO) nanofibers synthesized by electrospinning

Lotus, A.F.,Kang, Y.C.,Walker, J.I.,Ramsier, R.D.,Chase, G.G. Elsevier 2010 Materials science and engineering B. Advanced Func Vol.166 No.1

Zinc oxide nanofibers doped with aluminum oxide were prepared by sol-gel processing and electrospinning techniques using polyvinylpyrrolidone (PVP), zinc acetate and aluminum acetate as precursors. The resulting nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy, and current-voltage (I-V) properties. The nanofibers had diameters in the range of 60-150nm. The incorporation of aluminum oxide resulted in a decrease in the crystallite sizes of the zinc oxide nanofibers. Aluminum oxide doped zinc oxide (AOZO) nanofibers exhibited lower bandgap energies compared to undoped zinc oxide nanofibers. However, as the aluminum content (Al/(Al+Zn)x100%) was increased from 1.70at.% to 3.20at.% in the electrospinning solution, the bandgap energy increased resulting in lower conductivity. The electrical conductivity of the AOZO samples was found to depend on the amount of aluminum dopant in the matrix as reflected in the changes in oxidation state elucidated from XPS data. Electrospinning was found to be a productive, simple, and easy method for tuning the bandgap energy and conductivity of zinc oxide semiconducting nanofibers.

Spectral analysis of semi-actively controlled structures subjected to blast loading

C.M. Ewing,C. Guillin,R.P. Dhakal,J.G. Chase 국제구조공학회 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.33 No.1

This paper investigates the possibility of controlling the response of typical portal frame structures to blast loading using a combination of semi-active and passive control devices. A one storey reinforced concrete portal frame is modelled using non-linear finite elements with each column discretised into multiple elements to capture the higher frequency modes of column vibration response that are typical features of blast responses. The model structure is subjected to blast loads of varying duration, magnitude and shape, and the critical aspects of the response are investigated over a range of structural periods in the form of blast load response spectra. It is found that the shape or length of the blast load is not a factor in the response, as long as the period is less than 25% of the fundamental structural period. Thus, blast load response can be expressed strictly as a function of the momentum applied to the structure by a blast load. The optimal device arrangements are found to be those that reduce the first peak of the structural displacement and also reduce the subsequent free vibration of the structure. Semi-active devices that do not increase base shear demands on the foundations in combination with a passive yielding tendon are found to provide the most effective control, particularly if base shear demand is an important consideration, as with older structures. The overall results are summarised as response spectra for eventual potential use within standard structural design paradigms.

Temperature-induced changes in morphology and structure of TiO2–Al2O3 fibers

J.S. Tobin,A.J. Turinske,N. Stojilovic,A.F. Lotus,G.G. Chase 한국물리학회 2012 Current Applied Physics Vol.12 No.3

Electrospinning of a sol-gel and polymer mixture is used to produce titania-alumina (TiO2-Al2O3) fibers with diameters ranging from 200 to 800 nm. These composite metal-oxide fibers were calcined at various temperatures and their morphology is studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The decrease in the average diameter of the fibers with increasing temperature is observed. Powder X-ray diffraction (XRD) reveals that up to 800 ℃ the composite fibers have anatase titania structure whereas at 900 ℃ the fibers exhibit mixture of anatase and rutile phases. It is found that specific surface area decreases as a function of temperature in the 700-900 ℃ range. The change in phase (anatase-to-rutile) and the increase in crystallite size occur simultaneously. The presence of smaller amount of amorphous alumina in the primarily titania-based structure seems to play the role in stabilizing the anatase phase.