DCB

A Small Range Six-Axis Accelerometer Designed with High Sensitivity DCB Elastic Element.[Pubmed:27657089]

Sensors (Basel). 2016 Sep 21;16(9). pii: s16091552.

This paper describes a small range six-axis accelerometer (the measurement range of the sensor is +/-g) with high sensitivity DCB (Double Cantilever Beam) elastic element. This sensor is developed based on a parallel mechanism because of the reliability. The accuracy of sensors is affected by its sensitivity characteristics. To improve the sensitivity, a DCB structure is applied as the elastic element. Through dynamic analysis, the dynamic model of the accelerometer is established using the Lagrange equation, and the mass matrix and stiffness matrix are obtained by a partial derivative calculation and a conservative congruence transformation, respectively. By simplifying the structure of the accelerometer, a model of the free vibration is achieved, and the parameters of the sensor are designed based on the model. Through stiffness analysis of the DCB structure, the deflection curve of the beam is calculated. Compared with the result obtained using a finite element analysis simulation in ANSYS Workbench, the coincidence rate of the maximum deflection is 89.0% along the x-axis, 88.3% along the y-axis and 87.5% along the z-axis. Through strain analysis of the DCB elastic element, the sensitivity of the beam is obtained. According to the experimental result, the accuracy of the theoretical analysis is found to be 90.4% along the x-axis, 74.9% along the y-axis and 78.9% along the z-axis. The measurement errors of linear accelerations ax, ay and az in the experiments are 2.6%, 0.6% and 1.31%, respectively. The experiments prove that accelerometer with DCB elastic element performs great sensitive and precision characteristics.

AMECM/DCB scaffold prompts successful total meniscus reconstruction in a rabbit total meniscectomy model.[Pubmed:27718449]

Biomaterials. 2016 Dec;111:13-26.

Tissue-engineered meniscus regeneration is a very promising treatment strategy for meniscus lesions. However, generating the scaffold presents a huge challenge for meniscus engineering as this has to meet particular biomechanical and biocompatibility requirements. In this study, we utilized acellular meniscus extracellular matrix (AMECM) and demineralized cancellous bone (DCB) to construct three different types of three-dimensional porous meniscus scaffold: AMECM, DCB, and AMECM/DCB, respectively. We tested the scaffolds' physicochemical characteristics and observed their interactions with meniscus fibrochondrocytes to evaluate their cytocompatibility. We implanted the three different types of scaffold into the medial knee menisci of New Zealand rabbits that had undergone total meniscectomy; negative control rabbits received no implants. The reconstructed menisci and corresponding femoral condyle and tibial plateau cartilage were all evaluated at 3 and 6 months (n = 8). The in vitro study demonstrated that the AMECM/DCB scaffold had the most suitable biomechanical properties, as this produced the greatest compressive and tensile strength scores. The AMECM/DCB and AMECM scaffolds facilitated fibrochondrocyte proliferation and the secretion of collagen and glycosaminoglycans (GAGs) more effectively than did the DCB scaffold. The in vivo experiments demonstrated that both the AMECM/DCB and DCB groups had generated neomeniscus at both 3 and 6 months post-implantation, but there was no obvious meniscus regeneration in the AMECM or control groups, so the neomeniscus analysis could not perform on AMECM and control group. At both 3 and 6 months, histological scores were better for regenerated menisci in the AMECM/DCB than in the DCB group, and significantly better for articular cartilage in the AMECM/DCB group compared with the other three groups. Knee MRI scores (Whole-Organ Magnetic Resonance Imaging Scores (WORMS)) were better in the AMECM/DCB group than in the other three groups at both 3 and 6 months. At both 3 and 6 months, RT-PCR demonstrated that aggrecan, Sox9, and collagen II content was significantly higher, and mechanical testing demonstrated greater tensile strength, in the AMECM/DCB group neomenisci compared with the DCB group.

SeQuent Please vs. Pantera Lux drug coated balloon angioplasty in real life: Results from the Dusseldorf DCB registry.[Pubmed:28089147]

Int J Cardiol. 2017 Mar 15;231:68-72.

BACKGROUND: In-stent restenosis (ISR) is still a major concern in interventional cardiology. Drug coated balloon (DCB) angioplasty has been shown to be a promising option in treatment of ISR. However heterogeneity of different DCBs in suppression of neointimal growth has been described in a porcine model of coronary ISR. Therefore, in this registry analysis, we compared two frequently used paclitaxel eluting DCBs, the SeQuent Please and the Pantera Lux DCB. METHODS: 571 patients were treated with DCB angioplasty at the Heinrich-Heine University Dusseldorf between 2009 and 2012. Follow-up was conducted during ambulatory care at our department. Major adverse cardiac events (death, myocardial infarction [MI] and target lesion revascularization) were registered during hospitalization and follow-up. RESULTS: Patient characteristics, prior diseases, clinical presentation, ejection fraction, procedural success and lost-for-follow-up did not differ between patients treated with the SeQuent Please and. The Pantera Lux DCB. MACE during hospital course were similar as well (Pantera Lux: 6 patients [1.6%] vs. SeQuent(R)Please: 3 patients [1.5%], relative risk 1.06, 95% confidence interval 0.3-4.2, P=0.93). Event free survival was significantly longer in patients treated with the Pantera Lux DCB as compared to SeQuent Please DCB (Hazard ratio: 0.65, 95% confidence interval 0.43-0.98; P value of log-rank test: 0.0405). CONCLUSION: MACE free survival was longer in Pantera Lux DCB treated patients as compared to SeQuent Please treated patients. This finding has to be confirmed in future clinical trials.

A family of highly selective allosteric modulators of the metabotropic glutamate receptor subtype 5.[Pubmed:12920211]

Mol Pharmacol. 2003 Sep;64(3):731-40.

We have identified a family of highly selective allosteric modulators of the group I metabotropic glutamate receptor subtype 5 (mGluR5). This family of closely related analogs exerts a spectrum of effects, ranging from positive to negative allosteric modulation, and includes compounds that do not themselves modulate mGluR5 agonist activity but rather prevent other family members from exerting their modulatory effects. 3,3'-Difluorobenzaldazine (DFB) has no agonist activity, but it acts as a selective positive allosteric modulator of human and rat mGluR5. DFB potentiates threshold responses to glutamate, quisqualate, and 3,5-dihydroxyphenylglycine in fluorometric Ca2+ assays 3- to 6-fold, with EC50 values in the 2 to 5 microM range, and at 10 to 100 microM, it shifts mGluR5 agonist concentration-response curves approximately 2-fold to the left. The analog 3,3'-dimethoxybenzaldazine (DMeOB) acts as a negative modulator of mGluR5 agonist activity, with an IC50 of 3 microM in fluorometric Ca2+ assays, whereas the analog 3,3'-dichlorobenzaldazine (DCB) does not exert any apparent modulatory effect on mGluR5 activity. However, DCB seems to act as an allosteric ligand with neutral cooperativity, preventing the positive allosteric modulation of mGluRs by DFB as well as the negative modulatory effect of DMeOB. None of these analogs affects binding of [3H]quisqualate to the orthosteric (glutamate) site, but they do inhibit [3H]3-methoxy-5-(2-pyridinylethynyl)pyridine binding to the site for 2-methyl-6-(phenylethynyl)-pyridine, a previously identified negative allosteric modulator. With the use of these compounds, we provide evidence that allosteric sites on GPCRs can respond to closely related ligands with a range of pharmacological activities from positive to negative modulation as well as to neutral competition of this modulation.