Characterization of carbon nanotubes produced by arc discharge: Effect of the background pressure

Single walled carbon nanotubes (SWNT) produced by the anodic arc discharge over a range of constant background pressures of helium (100–1000 Torr) were examined under a high-resolution transmission electron microscope, and a Raman spectrometer. It was found that the average SWNT diameter is about 2 nm and fairly independent of the background pressure. Analysis of the relative purity of SWNTs samples suggests that highest SWNT relative concentration can be obtained at background pressure of about 200–300 Torr. Measured anode ablation rate increases linearly with background pressure. The model of the anodic arc discharge was developed. It was found that the predicted anode ablation rate agrees well with experiment suggesting that electron temperature in the anodic arc is about 0.5 eV. © 2004 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69876/2/JAPIAU-95-5-2749-1.pd

Cost-effectiveness of 10-kHz Spinal Cord Stimulation Therapy Compared With Conventional Medical Management Over the First 12 Months of Therapy for Patients With Nonsurgical Back Pain: Randomized Controlled Trial

Objective: This analysis evaluated if spinal cord stimulation (SCS) at 10 kHz plus conventional medical management (CMM) is cost-effective compared with CMM alone for the treatment of nonsurgical refractory back pain (NSRBP). Methods: NSRBP subjects were randomized 1:1 into the 10-kHz SCS (n = 83) or CMM (n = 76) group. Outcomes assessed at 6 months included EQ-5D 5-level (EQ-5D-5L), medication usage, and healthcare utilization (HCU). There was an optional crossover at 6 months and follow-up to 12 months. The incremental cost-effectiveness ratio (ICER) was calculated with cost including all HCU and medications except for the initial device and implant procedure, and cost-effectiveness was analyzed based on a willingness-to-pay threshold of \u3c $50,000 per quality-adjusted life-year. Results: Treatment with 10-kHz SCS resulted in a significant improvement in quality of life (QOL) over CMM (EQ-5D-5L index score change of 0.201 vs -0.042, p \u3c 0.001) at a lower cost, based on reduced frequency of HCU resulting in an ICER of -$4964 at 12 months. The ICER was -$8620 comparing the 6 months on CMM with postcrossover on 10-kHz SCS. Conclusions: Treatment with 10-kHz SCS provides higher QOL at a lower average cost per patient compared with CMM. Assuming an average reimbursement for device and procedure, 10-kHz SCS therapy is predicted to be cost-effective for the treatment of NSRBP compared with CMM within 2.1 years

Pulsed electromagnetic field applications: A corporate perspective

Corporate establishment of US Food & Drug Administration approved pulsed electromagnetic fields (PEMFs) for clinical applications has been achieved. However, optimization of PEMFs for improvement in efficacy for current indications, in addition to the expansion into new indications, is not trivial. Moving directly into a clinical trial can be costly and carries little guarantee for success, necessitating the need for preclinical studies as supported by this review of the extensive corporate preclinical experience by Orthofix, Inc. The Translational Potential of this Article: This review illustrates the need to gain enough in vitro/in vivo knowledge of specific PEMF signals and its target tissue interaction to enable a high success rate in clinical trials

Pulsed-electromagnetic-field induced osteoblast differentiation requires activation of genes downstream of adenosine receptors A2A and A3.

Pulsed-electromagnetic-field (PEMF) treatment was found to enhance cellular differentiation of the mouse preosteoblast, MC3T3-E1, to a more osteoblastic phenotype. Differentiation genes such as Alp, BSPI, cFos, Ibsp, Osteocalcin, Pthr1 and Runx2 showed increased expression in response to PEMF stimulation. Detailed molecular mechanisms linking PEMF to the activation of these genes are limited. Two adenosine receptors known to be modulated in response to PEMF, Adora2A and Adora3, were functionally impaired by CRISPR-Cas9-mediated gene disruption, and the consequences of which were studied in the context of PEMF-mediated osteoblastic differentiation. Disruption of Adora2A resulted in a delay of Alp mRNA expression, but not alkaline phosphatase protein expression, which was similar to that found in wild type cells. However, Adora3 disruption resulted in significantly reduced responses at both the alkaline phosphatase mRNA and protein levels throughout the PEMF stimulation period. Defects observed in response to PEMF were mirrored using a chemically defined growth and differentiation-inducing media (DM). Moreover, in cells with Adora2A disruption, gene expression profiles showed a blunted response in cFos and Pthr1 to PEMF treatment; whereas cells with Adora3 disruption had mostly blunted responses in AlpI, BSPI, Ibsp, Osteocalcin and Sp7 gene activation. To demonstrate specificity for Adora3 function, the Adora3 open reading frame was inserted into the ROSA26 locus in Adora3 disrupted cells culminating in rescued PEMF responsiveness and thereby eliminating the possibility of off-target effects. These results lead us to propose that there are complementary and parallel positive roles for adenosine receptor A2A and A3 in PEMF-mediated osteoblast differentiation

Dynamic imaging demonstrates that pulsed electromagnetic fields (PEMF) suppress IL-6 transcription in bovine nucleus pulposus cells.

Inflammatory cytokines play a dominant role in the pathogenesis of disc degeneration. Pulsed electromagnetic fields (PEMF) are noninvasive biophysical stimulus that has been used extensively in the orthopaedic field for many years. However, the specific cellular responses and mechanisms involved are still unclear. The objective of this study was to assess the time-dependent PEMF effects on pro-inflammatory factor IL-6 expression in disc nucleus pulposus cells using a novel green fluorescence protein (GFP) reporter system. An MS2-tagged GFP reporter system driven by IL-6 promoter was constructed to visualize PEMF treatment effect on IL-6 transcription in single living cells. IL-6-MS2 reporter-labeled cells were treated with IL-1α to mimic the in situ inflammatory environment of degenerative disc while simultaneously exposed to PEMF continuously for 4 h. Time-lapse imaging was recorded using a confocal microscope to track dynamic IL-6 transcription activity that was demonstrated by GFP. Finally, real-time RT-PCR was performed to confirm the imaging data. Live cell imaging demonstrated that pro-inflammatory factor IL-1α significantly promoted IL-6 transcription over time as compared with DMEM basal medium condition. Imaging and PCR data demonstrated that the inductive effect of IL-1α on IL-6 expression could be significantly inhibited by PEMF treatment in a time-dependent manner (early as 2 h of stimulus initiation). Our data suggest that PEMF may have a role in the clinical management of patients with chronic low back pain. Furthermore, this study shows that the MS2-tagged GFP reporter system is a useful tool for visualizing the dynamic events of mechanobiology in musculoskeletal research. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:778-787, 2018

Dynamic imaging demonstrates that pulsed electromagnetic fields (PEMF) suppress IL-6 transcription in bovine nucleus pulposus cells.

Inflammatory cytokines play a dominant role in the pathogenesis of disc degeneration. Pulsed electromagnetic fields (PEMF) are noninvasive biophysical stimulus that has been used extensively in the orthopaedic field for many years. However, the specific cellular responses and mechanisms involved are still unclear. The objective of this study was to assess the time-dependent PEMF effects on pro-inflammatory factor IL-6 expression in disc nucleus pulposus cells using a novel green fluorescence protein (GFP) reporter system. An MS2-tagged GFP reporter system driven by IL-6 promoter was constructed to visualize PEMF treatment effect on IL-6 transcription in single living cells. IL-6-MS2 reporter-labeled cells were treated with IL-1α to mimic the in situ inflammatory environment of degenerative disc while simultaneously exposed to PEMF continuously for 4 h. Time-lapse imaging was recorded using a confocal microscope to track dynamic IL-6 transcription activity that was demonstrated by GFP. Finally, real-time RT-PCR was performed to confirm the imaging data. Live cell imaging demonstrated that pro-inflammatory factor IL-1α significantly promoted IL-6 transcription over time as compared with DMEM basal medium condition. Imaging and PCR data demonstrated that the inductive effect of IL-1α on IL-6 expression could be significantly inhibited by PEMF treatment in a time-dependent manner (early as 2 h of stimulus initiation). Our data suggest that PEMF may have a role in the clinical management of patients with chronic low back pain. Furthermore, this study shows that the MS2-tagged GFP reporter system is a useful tool for visualizing the dynamic events of mechanobiology in musculoskeletal research. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:778-787, 2018

Early Osteogenic Marker Expression in hMSCs Cultured onto Acid Etching-Derived Micro- and Nanotopography 3D-Printed Titanium Surfaces

Polyetheretherketone (PEEK) titanium composite (PTC) is a novel interbody fusion device that combines a PEEK core with titanium alloy (Ti6Al4V) endplates. The present study aimed to investigate the in vitro biological reactivity of human bone-marrow-derived mesenchymal stem cells (hBM-MSCs) to micro- and nanotopographies produced by an acid-etching process on the surface of 3D-printed PTC endplates. Optical profilometer and scanning electron microscopy were used to assess the surface roughness and identify the nano-features of etched or unetched PTC endplates, respectively. The viability, morphology and the expression of specific osteogenic markers were examined after 7 days of culture in the seeded cells. Haralick texture analysis was carried out on the unseeded endplates to correlate surface texture features to the biological data. The acid-etching process modified the surface roughness of the 3D-printed PTC endplates, creating micro- and nano-scale structures that significantly contributed to sustaining the viability of hBM-MSCs and triggering the expression of early osteogenic markers, such as alkaline phosphatase activity and bone-ECM protein production. Finally, the topography of 3D-printed PTC endplates influenced Haralick’s features, which in turn correlated with the expression of two osteogenic markers, osteopontin and osteocalcin. Overall, these data demonstrate that the acid-etching process of PTC endplates created a favourable environment for osteogenic differentiation of hBM-MSCs and may potentially have clinical benefit

sj-xlsx-4-tct-10.1177_15330338221124658 - Supplemental material for In Vitro and in Vivo Study of the Effect of Osteogenic Pulsed Electromagnetic Fields on Breast and Lung Cancer Cells

Supplemental material, sj-xlsx-4-tct-10.1177_15330338221124658 for In Vitro and in Vivo Study of the Effect of Osteogenic Pulsed Electromagnetic Fields on Breast and Lung Cancer Cells by Mike Y. Chen, Jing Li, Nianli Zhang and Erik I. Waldorff, James T. Ryaby, Philip Fedor, Yongsheng Jia, Yujun Wang in Technology in Cancer Research & Treatment</p