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The unregulated commercialization of stem cell treatments: a global perspective

Douglas Sipp

《医学前沿(英文)》 2011年 第5卷 第4期   页码 348-355 doi: 10.1007/s11684-011-0150-x

摘要: Research into the biological properties and clinical potential of stem cells has spurred strong public investment, industry development, media coverage, and patient interest in recent years. To date, however, few clinical applications of demonstrated safety and efficacy have been developed with the exception of uses of hematopoietic stem cells in the treatment of diseases of the blood and immune systems. This lack of an evidence basis notwithstanding, hundreds of companies and private clinics around the world now sell putative stem cell treatments for an enormously broad range of medical and quality-of-life conditions. This represents a major challenge for legitimate scientists working in the field, for authorities seeking to protect their constituencies, and for patients and consumers targeted by such companies’ marketing strategies. In this review, I provide an overview of the global industry in pseudomedical stem cell treatments, with an investigation of claims in a single disease area (amyotrophic lateral sclerosis), and make recommendations for the introduction and enforcement of appropriate regulatory responses to this problem.

关键词: stem cell tourism     medical ethics     stem cell policy and regulation     alternative medicine    

Impact of diabetes and its treatments on skeletal diseases

null

《医学前沿(英文)》 2013年 第7卷 第1期   页码 81-90 doi: 10.1007/s11684-013-0243-9

摘要:

Diabetes mellitus is an enormous menace to public health globally. This chronic disease of metabolism will adversely affect the skeleton if not controlled. Both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) are associated with an increased risk of osteoporosis and fragility fractures. Bone mineral density is reduced in T1DM, whereas patients with T2DM have normal or slightly higher bone density, suggesting impaired bone quality is involved. Detrimental effects of T1DM on the skeleton are more severe than T2DM, probably because of the lack of osteo-anabolic effects of insulin and other pancreatic hormones. In both T1DM and T2DM, low bone quality could be caused by various means, including but not limited to hyperglycemia, accumulation of advanced glycosylation end products (AGEs), decreased serum levels of osteocalcin and parathyroid hormone. Risk for osteoarthritis is also elevated in diabetic population. How diabetes accelerates the deterioration of cartilage remains largely unknown. Hyperglycemia and glucose derived AGEs could contribute to the development of osteoarthritis. Moreover, it is recognized that oral antidiabetic medicines affect bone metabolism and turnover as well. Insulin is shown to have anabolic effects on bone and hyperinsulinemia may help to explain the slightly higher bone density in patients with T2DM. Thiazolidinediones can promote bone loss and osteoporotic fractures by suppressing osteoblastogenesis and enhancing osteoclastogenesis. Metformin favors bone formation by stimulating osteoblast differentiation and protecting them against diabetic conditions such as hyperglycemia. Better knowledge of how diabetic conditions and its treatments influence skeletal tissues is in great need in view of the growing and aging population of patients with diabetes mellitus.

关键词: diabetes     bone     osteoporosis     osteoarthritis    

Testing development of different surface treatments on pervious concrete

Mina YEKKALAR,Liv HASELBACH,Quinn LANGFITT

《结构与土木工程前沿(英文)》 2016年 第10卷 第4期   页码 385-393 doi: 10.1007/s11709-016-0351-0

摘要: Pervious concrete systems are developing stormwater management technologies which also have wintertime benefits as melting snow may percolate into the system instead of refreezing on the surface. Enhancing the surface microtexture of pervious concrete may also be beneficial in preventing icing or slipping by pedestrians. This research explored different surface treatments on pervious concrete specimens both qualitatively from personal judgements, and quantitatively through static friction measurements with a spring balance with respect to “slipperiness”. The tests were performed on both dry and wet specimens. One aim was to determine whether the spring balance method may be a simple test for comparing surface treatments on pavement samples with little surface area such as laboratory specimens or sidewalk sections. The other purpose was to make a preliminary decision of which surface treatments to use for a sidewalk installation for future studies on wintertime performance. The reliability analysis of the spring balance results showed that there was high operator consistency. In addition, there was a high level of consistency on average results between the quantitative and qualitative methods. This implies that the spring balance test may be an acceptable methodology for comparative analyses with respect to static friction.

关键词: pervious concrete     static coefficient of friction     pedestrian    

assimilable organic carbon (AOC) levels in MBR effluents followed by coagulation, ozonation and combined treatments

Xiaojie Shi, Zhuo Chen, Yun Lu, Qi Shi, Yinhu Wu, Hong-Ying Hu

《环境科学与工程前沿(英文)》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1360-8

摘要: Abstract • Annual AOCs in MBR effluents were stable with small increase in warmer seasons. • Significant increase in AOC levels of tertiary effluents were observed. • Coagulation in prior to ozonation can reduce AOC formation in tertiary treatment. • ∆UV254 and SUVA can be surrogates to predict the AOC changes during ozonation. As water reuse development has increased, biological stability issues associated with reclaimed water have gained attention. This study evaluated assimilable organic carbon (AOC) in effluents from a full-scale membrane biological reactor (MBR) plant and found that they were generally stable over one year (125–216 µg/L), with slight increases in warmer seasons. After additional tertiary treatments, the largest increases in absolute and specific AOCs were detected during ozonation, followed by coagulation-ozonation and coagulation. Moreover, UV254 absorbance is known to be an effective surrogate to predict the AOC changes during ozonation. Applying coagulation prior to ozonation of MBR effluents for removal of large molecules was found to reduce the AOC formation compared with ozonation treatment alone. Finally, the results revealed that attention should be paid to seasonal variations in influent and organic fraction changes during treatment to enable sustainable water reuse.

关键词: Assimilable organic carbon (AOC)     MBR effluents     Tertiary treatments     Coagulation     Ozonation    

Cytokine storm and translating IL-6 biology into effective treatments for COVID-19

《医学前沿(英文)》 doi: 10.1007/s11684-023-1044-4

摘要: As of May 3, 2023, the coronavirus disease 2019 (COVID-19) pandemic has resulted in more than 760 million confirmed cases and over 6.9 million deaths. Several patients have developed pneumonia, which can deteriorate into acute respiratory distress syndrome. The primary etiology may be attributed to cytokine storm, which is triggered by the excessive release of proinflammatory cytokines and subsequently leads to immune dysregulation. Considering that high levels of interleukin-6 (IL-6) have been detected in several highly pathogenic coronavirus-infected diseases, such as severe acute respiratory syndrome in 2002, the Middle East respiratory syndrome in 2012, and COVID-19, the IL-6 pathway has emerged as a key in the pathogenesis of this hyperinflammatory state. Thus, we review the history of cytokine storm and the process of targeting IL-6 signaling to elucidate the pivotal role played by tocilizumab in combating COVID-19.

关键词: SARS-CoV-2     COVID-19     cytokine storm     interleukin-6     tocilizumab    

Sonication and grinding pre-treatments on

Kit Wayne Chew, Pau Loke Show, Yee Jiun Yap, Joon Ching Juan, Siew Moi Phang, Tau Chuan Ling, Jo-Shu Chang

《环境科学与工程前沿(英文)》 2018年 第12卷 第4期 doi: 10.1007/s11783-018-1040-0

摘要:

Effects of sonication and grinding pretreatment on agarose quality were observed.

Successful agarose extraction with direct PEG method without the need to dry agar.

FTIR spectra and the characteristics peaks in agarose are explained.

Improvements in gel strength and sulfate content properties in agarose samples.

关键词: Agarose     Gelidium     Pretreatment     Seaweed     Sonication    

Uncertainty assessment in hydro-mechanical-coupled analysis of saturated porous medium applying fuzzy

Farhoud KALATEH, Farideh HOSSEINEJAD

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 387-410 doi: 10.1007/s11709-019-0601-z

摘要: The purpose of the present study was to develop a fuzzy finite element method, for uncertainty quantification of saturated soil properties on dynamic response of porous media, and also to discrete the coupled dynamic equations known as - hydro-mechanical equations. Input parameters included fuzzy numbers of Poisson’s ratio, Young’s modulus, and permeability coefficient as uncertain material of soil properties. Triangular membership functions were applied to obtain the intervals of input parameters in five membership grades, followed up by a minute examination of the effects of input parameters uncertainty on dynamic behavior of porous media. Calculations were for the optimized combinations of upper and lower bounds of input parameters to reveal soil response including displacement and pore water pressure via fuzzy numbers. Fuzzy analysis procedure was verified, and several numerical examples were analyzed by the developed method, including a dynamic analysis of elastic soil column and elastic foundation under ramp loading. Results indicated that the range of calculated displacements and pore pressure were dependent upon the number of fuzzy parameters and uncertainty of parameters within equations. Moreover, it was revealed that for the input variations looser sands were more sensitive than dense ones.

关键词: fuzzy finite element method     saturated soil     hydro-mechanical coupled equations     coupled analysis     uncertainty analysis    

Microbial responses to combined oxidation and catalysis treatment of 1,4-dioxane and co-contaminants in groundwater and soil

Yu Miao, Nicholas W. Johnson, Kimberly Heck, Sujin Guo, Camilah D. Powell, Thien Phan, Phillip B. Gedalanga, David T. Adamson, Charles J. Newell, Michael S. Wong, Shaily Mahendra

《环境科学与工程前沿(英文)》 2018年 第12卷 第5期 doi: 10.1007/s11783-018-1071-6

摘要:

Groundwater microbial community was altered after catalysis and chemical oxidation.

The coupled treatment train removed 90% 1,4-dioxane regardless of co-contaminants.

Dynamics of microbial populations varied along with different treatment stages.

Many microbial taxa exhibited resilience against oxidative and catalytic treatments.

Metagenomic analysis will be valuable for long-term management of polluted sites.

关键词: Coupled treatments     Chlorinated solvents     Diethylene ether     Biological diversity     Microbial populations     Biomarkers    

Assessment of oxidative and UV-C treatments for inactivating bacterial biofilms from groundwater wells

Kyle E. MURRAY,Erin I. Manitou-ALVAREZ,Enos C. INNISS,Frank G. HEALY,Adria A. BODOUR

《环境科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 39-49 doi: 10.1007/s11783-014-0699-0

摘要: Microorganisms are ubiquitous in natural environments and in water supply infrastructure including groundwater wells. Sessile-state microorganisms may build up on well surfaces as biofilms and, if excessive, cause biofouling that reduces well productivity and water quality. Conditions can be improved using biocides and other traditional well rehabilitation measures; however, biofilm regrowth is inevitable given the continuous introduction of microorganisms from the surrounding environment. Alternative and less invasive well maintenance approaches are desirable for reducing biofilm densities while also minimizing harmful disinfection-by-products. The primary objective of this research was to evaluate effectiveness of alternative treatments for inactivating microorganisms comprising biofilms. A novel approach was designed for in situ growth of biofilms on steel coupons suspended from ‘chandeliers’. After more than 100 days of in situ growth, biofilms were harvested, sampled, and baseline biofilm densities quantified through cultivation. Ultraviolet-C (UV-C) and oxidative treatments including hydrogen peroxide (H O ), ozone (O ) and mixed oxidants were then applied to the biofilms in laboratory-scale treatments. Microbial inactivation was assessed by comparing treated versus baseline biofilm densities. H O was the most effective treatment, and decreased density below baseline by as much as 3.1 orders of magnitude. Mixed oxidants were effective for the well having a lower density biofilm, decreasing density below baseline by as much as 1.4 orders of magnitude. Disparity in the response to treatment was apparent in the wells despite their spatial proximity and common aquifer source, which suggests that microbiological communities are more heterogeneous than the natural media from which they originate.

关键词: well rehabilitation     aquifer     biofouling     hydrogen peroxide     sustainability    

Thermal fluid-structure interaction and coupled thermal-stress analysis in a cable stayed bridge exposed

Nazim Abdul NARIMAN

《结构与土木工程前沿(英文)》 2018年 第12卷 第4期   页码 609-628 doi: 10.1007/s11709-018-0452-z

摘要: In this paper, thermal fluid structure-interaction (TFSI) and coupled thermal-stress analysis are utilized to identify the effects of transient and steady-state heat-transfer on the vortex induced vibration and fatigue of a segmental bridge deck due to fire incidents. Numerical simulations of TFSI models of the deck are dedicated to calculate the lift and drag forces in addition to determining the lock-in regions once using fluid-structure interaction (FSI) models and another using TFSI models. Vorticity and thermal convection fields of three fire scenarios are simulated and analyzed. Simiu and Scanlan benchmark is used to validate the TFSI models, where a good agreement was manifested between the two results. Extended finite element method (XFEM) is adopted to create 3D models of the cable stayed bridge to simulate the fatigue of the deck considering three fire scenarios. Choi and Shin benchmark is used to validate the damaged models of the deck in which a good coincide was seen between them. The results revealed that TFSI models and coupled thermal-stress models are significant in detecting earlier vortex induced vibration and lock-in regions in addition to predicting damages and fatigue of the deck due to fire incidents.

关键词: fire scenario     transient heat transfer     TFSI model     coupled thermal-stress     XFEM    

Vehicle-bridge coupled vibrations in different types of cable stayed bridges

Lingbo WANG,Peiwen JIANG,Zhentao HUI,Yinping MA,Kai LIU,Xin KANG

《结构与土木工程前沿(英文)》 2016年 第10卷 第1期   页码 81-92 doi: 10.1007/s11709-015-0306-x

摘要: Numerical analyses of the coupled vibrations of vehicle-bridge system and the effects of different types of cable stayed bridges on the coupled vibration responses have been presented in this paper using ANSYS. The bridge model and vehicle model were independently built which have no internal relationship in the ANSYS. The vehicle-bridge coupled vibration relationship was obtained by using the APDL program which subsequently imposed on the vehicle and bridge models during the numerical analysis. The proposed model was validated through a field measurements and literature data. The judging method, possibility, and criterion of the vehicle-bridge resonance (coupled vibrations) of cable stayed bridges (both the floating system and half floating system) under traffic flows were presented. The results indicated that the interval time between vehicles is the main influence factor on the resonance excitation frequency under the condition of equally spaced traffic flows. Compared to other types of cable stayed bridges, the floating bridge system has relatively high possibility to cause vehicle-bridge resonance.

关键词: vehicle-bridge coupled vibration     cable stayed bridge     resonances of vehicle-bridge system    

Isogeometric analysis of coupled thermo-elastodynamic problems under cyclic thermal shock

Asghar AMANI DASHLEJEH

《结构与土木工程前沿(英文)》 2019年 第13卷 第2期   页码 397-405 doi: 10.1007/s11709-018-0473-7

摘要: The isogeometric analysis (IGA) method was extended for the solution of the coupled thermo-elastodynamic equations. The dimensionless formulation was accepted in discretization of the uncoupled and coupled thermoelasticity equations and the Generalized Newmark method was used in the time integration procedure. First, the performance of the proposed method was verified against a two-dimensional benchmark example subjected to constant thermal shock with available exact analytical solutions. Then a two-dimensional half-space benchmark example under thermal shock was solved. Finally, cyclic thermal shock (CTS) loading was applied on the half-space problem. The results dedicated that IGA can be used as a suitable approach in the analysis of the general thermomechanical problems.

关键词: isogeometric analysis     coupled thermo-elastodynamic     dynamic analysis     generalized newmark     cyclic thermal shock    

Stress induced polarization switching and coupled hysteretic dynamics in ferroelectric materials

Linxiang WANG, Roderick MELNIK, Fuzai LV

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 287-291 doi: 10.1007/s11465-011-0230-2

摘要:

The dynamic responses of ferroelectric materials upon external mechanical and electrical stimulations are inherently nonlinear and coupled. In the current paper, a macroscopic differential model is constructed for the coupled hysteretic dynamics via modeling the orientation switching induced in the materials. A non-convex potential energy is constructed with both mechanic and electric field contributions. The governing equations are formulated as nonlinear ordinary differential equations by employing the Euler-Lagrange equation, and can be easily recast into a state space form. Hysteresis loops associated with stress induced polarization switching and butterfly-shaped behavior in ferroelectric materials are also successfully captured. The effects of mechanical loadings on the electrically induced switching are numerically investigated, as well as the mechanically-induced switching with various bias electric fields.

关键词: differential model     state space     electromechanical switching     butterfly effects     hysteresis    

Scenario analysis of water pollution control in the typical peri-urban river using a coupled hydrodynamic-water

Haifeng JIA, Shuo WANG, Mingjie WEI, Yansong ZHANG

《环境科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 255-265 doi: 10.1007/s11783-010-0279-x

摘要: The water quality pollution and ecological deterioration in peri-urban rivers are usually serious under rapid urbanization and economic growth. In the study, a typical peri-urban river, Nansha River, was selected as a case study to discuss the scheme of peri-urban river rehabilitation. Located in the north part of the Beijing central region, the Nansha River watershed has been designated as an ecologically friendly garden-style area with high-tech industry parks and upscale residential zones. However, the Nansha River is currently seriously contaminated by urban and rural pollutants from both nonpoint sources (NPS) and point sources (PS). In this study, the pollutant loads from point sources and nonpoint sources in the Nansha River watershed were first assessed. A coupled model, derived from the Environmental Fluid Dynamics Code and Water Quality Analysis Simulation Program, was developed to simulate the hydrodynamics and water quality in the Nansha River. According to the characteristics of the typical peri-urban river, three different PS and NPS control scenarios were designed and examined by modeling analyses. Based on the results of the scenario analysis, a river rehabilitation scheme was recommended for implementation.

关键词: peri-urban river     coupled hydrodynamic-water quality modeling     scenario analysis     river rehabilitation    

Hole quality in longitudinal–torsional coupled ultrasonic vibration assisted drilling of carbon fiber

Guofeng MA, Renke KANG, Zhigang DONG, Sen YIN, Yan BAO, Dongming GUO

《机械工程前沿(英文)》 2020年 第15卷 第4期   页码 538-546 doi: 10.1007/s11465-020-0598-y

摘要: Carbon fiber reinforced plastic (CFRP) composites are extremely attractive in the manufacturing of structural and functional components in the aircraft manufacturing field due to their outstanding properties, such as good fatigue resistance, high specific stiffness/strength, and good shock absorption. However, because of their inherent anisotropy, low interlamination strength, and abrasive characteristics, CFRP composites are considered difficult-to-cut materials and are prone to generating serious hole defects, such as delamination, tearing, and burrs. The advanced longitudinal–torsional coupled ultrasonic vibration assisted drilling (LTC-UAD) method has a potential application for drilling CFRP composites. At present, LTC-UAD is mainly adopted for drilling metal materials and rarely for CFRP. Therefore, this study analyzes the kinematic characteristics and the influence of feed rate on the drilling performance of LTC-UAD. Experimental results indicate that LTC-UAD can reduce the thrust force by 39% compared to conventional drilling. Furthermore, LTC-UAD can decrease the delamination and burr factors and improve the surface quality of the hole wall. Thus, LTC-UAD is an applicable process method for drilling components made with CFRP composites.

关键词: longitudinal–torsional coupled     ultrasonically drilling     CFRP     thrust force     hole quality    

标题 作者 时间 类型 操作

The unregulated commercialization of stem cell treatments: a global perspective

Douglas Sipp

期刊论文

Impact of diabetes and its treatments on skeletal diseases

null

期刊论文

Testing development of different surface treatments on pervious concrete

Mina YEKKALAR,Liv HASELBACH,Quinn LANGFITT

期刊论文

assimilable organic carbon (AOC) levels in MBR effluents followed by coagulation, ozonation and combined treatments

Xiaojie Shi, Zhuo Chen, Yun Lu, Qi Shi, Yinhu Wu, Hong-Ying Hu

期刊论文

Cytokine storm and translating IL-6 biology into effective treatments for COVID-19

期刊论文

Sonication and grinding pre-treatments on

Kit Wayne Chew, Pau Loke Show, Yee Jiun Yap, Joon Ching Juan, Siew Moi Phang, Tau Chuan Ling, Jo-Shu Chang

期刊论文

Uncertainty assessment in hydro-mechanical-coupled analysis of saturated porous medium applying fuzzy

Farhoud KALATEH, Farideh HOSSEINEJAD

期刊论文

Microbial responses to combined oxidation and catalysis treatment of 1,4-dioxane and co-contaminants in groundwater and soil

Yu Miao, Nicholas W. Johnson, Kimberly Heck, Sujin Guo, Camilah D. Powell, Thien Phan, Phillip B. Gedalanga, David T. Adamson, Charles J. Newell, Michael S. Wong, Shaily Mahendra

期刊论文

Assessment of oxidative and UV-C treatments for inactivating bacterial biofilms from groundwater wells

Kyle E. MURRAY,Erin I. Manitou-ALVAREZ,Enos C. INNISS,Frank G. HEALY,Adria A. BODOUR

期刊论文

Thermal fluid-structure interaction and coupled thermal-stress analysis in a cable stayed bridge exposed

Nazim Abdul NARIMAN

期刊论文

Vehicle-bridge coupled vibrations in different types of cable stayed bridges

Lingbo WANG,Peiwen JIANG,Zhentao HUI,Yinping MA,Kai LIU,Xin KANG

期刊论文

Isogeometric analysis of coupled thermo-elastodynamic problems under cyclic thermal shock

Asghar AMANI DASHLEJEH

期刊论文

Stress induced polarization switching and coupled hysteretic dynamics in ferroelectric materials

Linxiang WANG, Roderick MELNIK, Fuzai LV

期刊论文

Scenario analysis of water pollution control in the typical peri-urban river using a coupled hydrodynamic-water

Haifeng JIA, Shuo WANG, Mingjie WEI, Yansong ZHANG

期刊论文

Hole quality in longitudinal–torsional coupled ultrasonic vibration assisted drilling of carbon fiber

Guofeng MA, Renke KANG, Zhigang DONG, Sen YIN, Yan BAO, Dongming GUO

期刊论文