Simple Centrifuge Research Articles

Establishing a productive heterogeneous catalyst based on silver nanoparticles supported on a crosslinked vinyl polymer for the reduction of nitrophenol.

The treatment of toxic nitrophenols in industrial wastewater is urgently needed from environmental, health, and economic points of view. The current study addresses the synthesis of the crosslinked vinyl polymer poly(acrylonitrile-co-2-acrylamido-2-methylpropane sulfonic acid) (poly(AN-co-AMPS)) through free radical copolymerization techniques using acrylonitrile (AN) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) monomers with different ratios and potassium persulfate (KPS) as an initiator in an aqueous medium. The prepared copolymer was utilized as a supporting matrix for silver nanoparticles (AgNPs) via the chemical reduction of silver nitrate within the copolymer framework. Different techniques were employed to characterize the prepared poly(AN-co-AMPS) and Ag/poly(AN-co-AMPS) composites, such as Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analysis. The results exhibit that silver metal was excellently dispersed across the surface of poly(AN-co-AMPS) without any agglomeration, presenting as nanocrystals with an average particle size equal to 6.21 nm. Also, BET analysis confirmed that the Ag/poly(AN-co-AMPS) composite exhibits mesoporous characteristics with a surface area of 59.615 m2 g-1. Moreover, the Ag/poly(AN-co-AMPS) composite was effectively applied as a heterogeneous catalyst for the catalytic reduction of hazardous 4-nitrophenols (4-NP) with a rate constant equal to 0.28 min-1 and half-life time equal to 2.47 min to a less toxic compound in the presence of NaBH4 as a reductant. Furthermore, the reusability experiment confirmed the excellent stability of Ag/poly(AN-co-AMPS). The catalyst can be easily separated from the reaction mixture using a simple centrifuge and directly reused for up to four successive cycles without a remarkable decrease in its catalytic activity. The conversion percentage of 4-NP after the four cycles was found to be 93%.

Roles of pre- and post-liquefaction stages in dynamic system response of liquefiable sand retained by a sheet-pile wall

This study examines the dynamic system response of a liquefiable deposit retained by a sheet-pile wall, with emphasis on the roles of pre- and post-liquefaction stages of soil response. A recently developed constitutive model, SANISAND-MSf, is utilized to simulate the pre- and post-liquefaction cyclic response of sands. The model is a stress-ratio controlled, critical state compatible, bounding surface plasticity model, which incorporates the concepts of memory surface and semifluidized state. The model’s performance is validated using a combination of cyclic simple shear tests and dynamic centrifuge tests from the LEAP-2020 project. A sensitivity analysis is then conducted by varying the base input motion intensity and duration. The results reveal that the amplitude of equivalent uniform base acceleration in pre-liquefaction correlates well with the timing of liquefaction triggering, and the cumulative absolute velocity of the base acceleration during the post-liquefaction stage correlates well with the post-liquefaction displacements. The study highlights the importance of accurately simulating response in the pre-liquefaction stage for the extent and timing of occurrence of liquefaction, which regulates the remaining intensity and duration of shaking, and in turn, affects the post-liquefaction permanent deformations at the system level.

Synthesis and characterization of super high surface area silica-based nanoparticles for adsorption and removal of toxic pharmaceuticals from aqueous solution

Tetracycline is a broad-spectrum antibiotic that is commonly applied to cure common illnesses in both people and animals. Tetracycline is still one of the most enduring micro-pollutants in the environment due to its indiscriminate misuse. In this study, a high surface area nanoadsorbent aminopropyltriethoxysilane@silica nanoparticles (3-APTS@SNPs) were synthesized and characterized through XRD, BET, XPS, HR-TEM, and FE-SEM. Then it was tested to see if it could adsorb tetracycline from an aqueous solution. The maximal tetracycline adsorption capability of the nanoadsorbent 3-APTS@SNPs was 875.47 mg/g. Additionally, the batch adsorption experiments revealed that 3-APTS@SNPs' adsorption followed and fit the Langmuir isotherm (R2 = 0.999) and pseudo-second-order kinetics (R2 = 0.999), respectively. At pH 7.0, additional tuning using response surface methods and a genetic algorithm increased the 3-APTS@SNPs' overall removal efficiency. The thermodynamic parameter was determined through a study of the effect of temperature, and the reactions were endothermic and chemisorption processes. The mechanism analysis showed that the majority of the adsorption was chemical adsorption (π-π interaction, electrostatic interaction, ion exchange, and chemical bonds) and physical adsorption. An important factor that ensured the adsorbent's significant potential for useful wastewater treatment was that it had exceptional cycle stability and could be quickly recovered from aqueous media using a simple centrifuge.

A low-cost and open-source mini benchtop centrifuge for molecular biology labs

The aim of this manuscript is to provide all the necessary information to build a simple benchtop mini centrifuge that is able to remove droplets and liquid film from the inner wall of PCR tubes and PCR strips following vortexing. Users can choose between two rotors: one can hold up to six tubes (1.5/2ml, or 500 µl and 200 µl tubes with adapters) or two PCR strips.The design consists of only three printed parts (optimized to be printed without supports) and cheap off-the-shelf components (80 mm computer fan, switches, food container and power supply). It can be assembled with basic soldering skills, no programming needed.While the total cost of materials is only 20 €, when compared to its commercial counterparts, this DIY benchtop spinner was equally capable to remove droplets. Comparing noise levels this model was quieter than an Eppendorf 5424, BioSan MSC-6000 or Kisker biotech centrifuges.Because it is designed to perform a very generic and common task, it could be useful for a very wide array of laboratories and researchers: molecular biology, genetics, microbiology, student labs, biohacking labs, etc.

Three-dimensional ordered macroporous imprinted polymer for bisphenol A recognition.

A novel kind of three-dimensional ordered macroporous molecular imprinted polymer (3DOM MIP) was prepared and studied. Monodisperse silica microspheres were used to form silica crystal template via simple centrifuge. In the presence of template molecule, acrylamide and trimethylolpropane trimethacrylate were co-polymerized in the interstices of crystal template bisphenol A (BPA). Hydrofluoric acid were employed to etch silica crystal and the mixed solvent of methanol with acetic acid were employed to extract template molecule. The results of SEM and FTIR confirmed the successful synthesis of 3DOM MIP. The obtained 3DOM MIP exhibited a rapid adsorption kinetics and a specific adsorption capacities toward template molecule because of the small size of MIP wall, which possessed much more effective imprinted cavies. Meanwhile, 3DOM MIP could selective recognized BPA from its structural analogues.

A Simple and Fast Manual Centrifuge to Spin Solutions in 96-Well PCR Plates.

A simple and fast manual centrifuge was developed to spin down solutions in 96-well polymerase chain reaction (PCR) plates. A commercially available salad spinner was utilized for this purpose. Acceleration and deceleration of the centrifuge were faster than those of a conventional electric centrifuge using 96-well PCR plates. Solutions in a 96-well PCR plate settled quickly after centrifuging for only 3 s. This lightweight centrifuge can be stored under a laboratory bench or on a shelf and can be put on the bench only when required, whereas the electric centrifuge is immobile due to its weight and the requirement of electric cables. This simple centrifuge is inexpensive, requires minimal effort for making, and can be used anywhere.

Continuum solutions for tunnel–building interaction and a modified framework for deformation prediction

In this paper, the response of buildings to tunnelling-induced ground movements is studied with elastic and elastoplastic continuum solutions that consider the structure as an equivalent simple beam. A comparison is made between these simple solutions and centrifuge test data to provide insights into flexural and axial building deformations of low-rise bearing wall structures on strip foundations; the influence of wall openings and the foundation scheme on the equivalent beam bending stiffness is also addressed. Subsequently, the effects of structural continuity across greenfield sagging and hogging regions on tunnel–structure interaction are investigated. Finally, the continuum solutions are used to propose a modification factor formulation that accounts for the change in settlement trough shape (compared to the greenfield) due to soil–structure interaction. This formulation, for example, accounts for the change in transverse length of the hogging and sagging regions of a building due to soil–structure interaction, eliminating the need to divide the building at the greenfield inflection points when calculating modification factors. The proposed formulation, which is compared with numerical, experimental and field data from previous research, is shown to better predict flexural building deformations.

Compressible Fe3O4/MWCNTs-coated polymer foams for high-performance and tunable electromagnetic microwave absorption

High-performance microwave absorption materials (MAMs) over gigahertz (2∼18 GHz) with tunable microwave absorption (MA) abilities have become indispensable to fight complex and changeable electromagnetic (EM) environments. Herein, Fe3O4/multiwalled carbon nanotube (MWCNTs)-coated polymer foams with high-performance and tunable MA properties were prepared using a simple dip and centrifuge method. The morphologies of the samples impregnated with resin showed that Fe3O4/MWCNTs were coated uniformly on the porous polyurethane foams skeleton. Moreover, the polymer foams had superior MA properties, especially the samples with 20 vol% Fe3O4 and 14 vol% MWCNTs possessed 5 GHz effective absorption area (reflection loss (RL) < −10 dB) at 16 mm thickness, which was attributed to the simultaneous effect of impedance characteristic, dielectric loss, magnetic loss, and porous structures. The EM characteristics and RL properties of the prepared polymer foams could be simply tuned by mechanically compressing, and the results indicated that the RL peak value moved towards the high frequency as the compressibility increased.

Blood Plasma Separation Using a Fidget-Spinner.

In this study, we present a simple, hand-powered, and electricity-free centrifuge platform based on a commercially available "fidget-spinner." The centrifugal force provided by this inexpensive and easy-to-use toy is sufficient to separate whole blood, producing a plasma yield rate and purity of 30% and 99%, respectively, separated in as little as 4-7 min. We verified the separated plasma by performing a paper-based HIV-1 p24 capsid protein enzyme-linked immunosorbent assay, which achieved a recovery rate of up to 98%, indicating the plasma features extremely low matrix interference effects. These results demonstrate the reliability of the platform for practical use, in addition to greatly reducing the overall cost and time of analysis while retaining detection precision, making it suitable for medical applications in resource-limited regions of the world.

An Endochronic-based approach for simulating pore water pressure variation during liquefaction of sand

Liquefaction is one of the consequences of earthquake in soil layers comprised of saturated loose sands. Various aspects of liquefaction have been investigated using different methods of field, laboratory, and numerical studies. Numerical simulation of liquefaction constitutes a major part of these researches. Application of a proper constitutive law in the numerical analysis is crucial for modeling thecomplicated undrained behavior of saturated sands during dynamic loading. Simplicity of formulation, limited number of parameters, and good performance are the main features of a proper constitutive law. In this study, an Endochronicbased model for simulating liquefaction of sand is implemented into the finite element program, PISA. Coupled dynamic field equations of Biot’s theory with u-p formulation are used to determine pore fluid and soil skeleton responses. Generalized Newmark method is employed for integration in time. The developed code is capable of predicting the magnitude of the generated pore water pressure, coupled with advanced constitutive laws such as critical state twosurface plasticity as well as simple models such as Mohr- Coulomb. Simulating cyclic simple shear and centrifuge tests using Endochronic model showed favorable performance of this model for predicting the variation of pore water pressure in saturated soil layers subjected to earthquake excitations.

Separation of Semiconducting Carbon Nanotubes for Flexible and Stretchable Electronics Using Polymer Removable Method.

Electronics that are soft, conformal, and stretchable are highly desirable for wearable electronics, prosthetics, and robotics. Among the various available electronic materials, single walled carbon nanotubes (SWNTs) and their network have exhibited high mechanical flexibility and stretchability, along with comparable electrical performance to traditional rigid materials, e.g. polysilicon and metal oxides. Unfortunately, SWNTs produced en masse contain a mixture of semiconducting (s-) and metallic (m-) SWNTs, rendering them unsuitable for electronic applications. Moreover, the poor solubility of SWNTs requires the introduction of insulating surfactants to properly disperse them into individual tubes for device fabrication. Compared to other SWNT dispersion and separation methods, e.g., DNA wrapping, density gradient ultracentrifugation, and gel chromatography, polymer wrapping can selectively disperse s-SWNTs with high selectivity (>99.7%), high concentration (>0.1 mg/mL), and high yield (>20%). In addition, this method only requires simple sonication and centrifuge equipment with short processing time down to 1 h. Despite these advantages, the polymer wrapping method still faces two major issues: (i) The purified s-SWNTs usually retain a substantial amount of polymers on their surface even after thorough rinsing. The low conductivity of the residual polymers impedes the charge transport in SWNT networks. (ii) Conjugated polymers used for SWNT wrapping are expensive. Their prices ($100-1000/g) are comparable or even higher than those of SWNTs ($10-300/g). These utilized conjugated polymers represent a large portion of the overall separation cost. In this Account, we summarize recent progresses in polymer design for selective dispersion and separation of SWNTs. We focus particularly on removable and/or recyclable polymers that enable low-cost and scalable separation methods. First, different separation methods are compared to show the advantages of the polymer wrapping methods. In specific, we compare different characterization methods used for purity evaluation. For s-SWNTs with high purity, i.e., >99%, short-channel (smaller than SWNT length) electrical measurement is more reliable than optical methods. Second, possible sorting mechanism and molecular design strategies are discussed. Polymer parameters such as backbone design and side chain engineering affect the polymer-SWNT interactions, leading to different dispersion concentration and selectivity. To address the above-mentioned limiting factors in both polymer contamination and cost issues, we describe two important polymer removal and cycling approaches: (i) changing polymer wrapping conformation to release SWNTs; (ii) depolymerization of conjugated polymer into small molecular units that have less affinity toward SWNTs. These methods allow the removal and recycling of the wrapping polymers, thus providing low-cost and clean s-SWNTs. Third, we discuss various applications of polymer-sorted s-SWNTs, including flexible/stretchable thin-film transistors, thermoelectric devices, and solar cells. In these applications, polymer-sorted s-SWNTs and their networks have exhibited good processability, attractive mechanical properties, and high electrical performance. An increasing number of studies have shown that the removable polymer approaches can completely remove polymer residues in SWNT networks and lead to enhanced charge carrier mobility, higher conductivity, and better heterojunction interface.

LEAP-GWU-2015 centrifuge test at UC Davis

For the LEAP-GWU-2015 exercise, a relatively simple centrifuge test was conducted in parallel at 6 centrifuge facilities including the University of California Davis (UCD). The experiment consisted of a submerged medium dense clean sand with a 5° slope subjected to 1Hz ramped sine wave base motion in a rigid container. This paper explains several details of the experiment at UCD including intended and unintended deviations from the specification and the implementation of new techniques for measurement of saturation of the centrifuge model. One unintended critical deviation was the use of pore fluid that was more viscous than specified; this had significant effect on the pore pressure dissipation time. The other important deviation from the specification was the incomplete ground motion sequence. While it is not ideal for purposes of determining the replicability of centrifuge tests, the differences between experiments diversifies the data available for validation of numerical models.

Rheological and physical characteristics of crustal-scaled materials for centrifuge analogue modelling

We characterize a set of analogue materials used for centrifuge analogue modelling simulating deformation at different levels in the crust simultaneously. Specifically, we improve the rheological characterization in the linear viscoelastic region of materials for the lower and middle crust, and cohesive synthetic sands without petroleum-binding agents for the upper crust. Viscoelastic materials used in centrifuge analogue modelling demonstrate complex dynamic behaviour, so viscosity alone is insufficient to determine if a material will be an effective analogue. Two series of experiments were conducted using an oscillating bi-conical plate rheometer to measure the storage and loss moduli and complex viscosities of several modelling clays and silicone putties. Tested materials exhibited viscoelastic and shear-thinning behaviour. The silicone putties and some modelling clays demonstrated viscous-dominant behaviour and reached Newtonian plateaus at strain rates < 0.5 × 10−2 s−1, while other modelling clays demonstrated elastic-dominant power-law relationships. Based on these results, the elastic-dominant modelling clay is recommended as an analogue for basement cratons. Inherently cohesive synthetic sands produce fine-detailed fault and fracture patterns, and developed thrust, strike-slip, and extensional faults in simple centrifuge test models. These synthetic sands are recommended as analogues for the brittle upper crust. These new results increase the accuracy of scaling analogue models to prototype. Additionally, with the characterization of three new materials, we propose a complete lithospheric profile of analogue materials for centrifuge modelling, allowing future studies to replicate a broader range of crustal deformation behaviours.

Centrifugal Filter Device for Detection of Rare Cells With Immuno-Binding.

Many investigations have shown circulating tumor cells (CTCs) to serve as a significant biomarker of cancer progression and for cancer treatment. Multiple blood samples detection of CTCs during a course of treatment might facilitate a choice by a medical doctor of an effective drug and a treatment for particular patients. A simple and cost-effective method to identify the trend of decreasing CTCs during a treatment with various therapies is in great demand. A novel multilayer, concentric filter device combined with an immune-binding method enables the enrichment and detection of rare cells in a mass cell population with a separation based on size. Such separation implemented with a filter is among the most efficient, simple and inexpensive methods to isolate cells, but its main disadvantages are clogging, deformation of cells, and a requirement of a significant difference of size between targeted rare cells and normal cells. We designed a concentric filter device and an immune-binding method to create a significant size difference of target cells, and increased the efficiency of separation to identify rare cells with a simple miniature centrifuge in the laboratory. The enrichment of target rare cells from a mass cell population and the detection were demonstrated on mixing targeted MCF-7 blast cancer cells and Jurkat blood cells in ratio 1:1 000 000. The device is prospectively applicable for the detection of circulating tumor cells in a clinical application.

Inhomogeneous delithiation behavior of chemically delithiated Li0.49FePO4 particles of different sizes using a simple centrifuge separation method

To understand the delithiation behavior of particles of different sizes, we developed a centrifugation method to separate particles in a chemically-delithiated Li0.49FePO4 with respect to their size. Small particles were obtained at high centrifuge speed whereas large particles were obtained at low centrifuge speed. The proportions of FePO4 and LiFePO4 in the separated particles were investigated to understand their delithiation behavior. Small particles were almost fully-transformed to FePO4 whereas large particles were still mostly LiFePO4. The inhomogeneous delithiation of particles could be also observed in the electrode. The electrode showed a voltage overshoot in the middle of the two-phase region during charging. Considering that the voltage overshoot is related to nucleation, this observation indicates that some particles in the middle of two-phase region are still in the LiFePO4 phase that must be nucleated. The inhomogeneous delithiation behavior of LiFePO4 particles of different sizes may be an intrinsic property irrespective of the delithiation method. To improve the utilization of active materials, the inhomogeneous delithiation of particles should be minimized by engineering the configuration of the electrode.

The Delithiation Behavior of LiFePO4 Particles with Broad Particle Size Distribution during Chemically Delithiation

LiFePO4 is the most promising cathode material, especially for electric vehicle (EV) because of its inexpensive cost, superior thermal and structural safety, and non-toxicity. Although LiFePO4 has been believed to be poor conductor due to its low electronic conductivity and 1D lithium diffusion, nano-sized LiFePO4 shows the fastest electrochemical reaction during charge and discharge.To understand these intriguing behaviors, we have to consider delithiation behavior of particles in the electrode which consists of 1010 ~ 1017 particles in addition to the transport properties in the material because a particle has a non-monotonic chemical potential[1]. The non-monotonic chemical potential of single particle in multi-particle electrode leads to characteristic electrochemical behaviors such as a flat potential in voltage curve of the electrode and a sequential phase transformation between particles. Thus, delithiation behaviors in a particle in the electrode should be understood.In this study, we will explore delithiation behaviors of LiFePO4 with broad particle size distribution. For this purpose, chemical delithiation and followed centrifuge method were applied to understand the delithiation behavior of LiFePO4 depending on particle size. This simple method shows phase transformation behaviors more directly. We synthesized LiFePO4 with broad particle size distribution by solid state reaction. And then, we can easily separate chemically delithiated small and large particles by centrifuge method. In this talk, we will introduce simple centrifuge method and will discuss about delithiation behavior of LiFePO4 with broad particle size distribution during chemical delithiation.[1] W. Dreyer et al 2010 The thermodynamic origin of hysteresis in insertion batteries Nature Mat. 9, 448.

Release of growth factors from a reinforced collagen GAG matrix supplemented with platelet rich plasma: Influence on cultured human meniscal cells

Damage to meniscal cartilage has been strongly linked to accelerated articular wear and consequently to osteoarthritis. Damage might be ameliorated by delivery of growth factors from platelet rich plasma (PRP) via a fiber reinforced collagen matrix designed for meniscal repair. PRP composition, release of growth factors, and influence on meniscal cell growth and gene expression were investigated. PRP was prepared using Harvest Smartprep (HS-PRP), Cascade Fibrinet (CF-PRP), and a simple centrifuge protocol (DC-PRP) from four donors each. CF-PRP had the highest ratio of platelets, with very few other blood cell types. HS-PRP had the highest total number of platelets but also contained high levels of red and white blood cells. Absorbed to collagen matrices HS-PRP released the highest levels of TGF-β1 and PDGF-AB with DC-PRP the most IGF-1. Cumulative release from collagen matrix was 48 ng/cm(3) IGF-1, 96 ng/cm(3) TGF-β1, and 9.6 ng/cm(3) PDGF-AB. Collagen matrix with PRP was able to increase meniscal cell number above peripheral whole blood and up-regulated gene expression of Aggrecan, Collagen type I (α1), and Elastin (3.3 ± 0.8-fold, 2.9 ± 0.6-fold, 4.0 ± 1.4-fold, respectively). Demonstrating that PRP combined with fiber reinforced collagen matrix could influence meniscal cells and might be of use for treating meniscal defects.

Scalable and Selective Dispersion of Semiconducting Arc-Discharged Carbon Nanotubes by Dithiafulvalene/Thiophene Copolymers for Thin Film Transistors

We report a simple and scalable method to enrich large quantities of semiconducting arc-discharged single-walled carbon nanotubes (SWNTs) with diameters of 1.1-1.8 nm using dithiafulvalene/thiophene copolymers. Stable solutions of highly individualized and highly enriched semiconducting SWNTs were obtained after a simple sonication and centrifuge process. Molecular dynamics (MD) simulations of polymer backbone interactions with and without side chains indicated that the presence of long alkyl side chains gave rise to the selectivity toward semiconducting tubes, indicating the importance of the roles of the side chains to both solubilize and confer selectivity to the polymers. We found that, by increasing the ratio of thiophene to dithiafulvalene units in the polymer backbone (from pDTFF-1T to pDTFF-3T), we can slightly improve the selectivity toward semiconducting SWNTs. This is likely due to the more flexible backbone of pDTFF-3T that allows the favorable wrapping of SWNTs with certain chirality as characterized by small-angle X-ray scattering. However, the dispersion yield was reduced from pDTFF-1T to pDTFF-3T. MD simulations showed that the reduction is due to the smaller polymer/SWNT contact area, which reduces the dispersion ability of pDTFF-3T. These experimental and modeling results provide a better understanding for future rational design of polymers for sorting SWNTs. Finally, high on/off ratio solution-processed thin film transistors were fabricated from the sorted SWNTs to confirm the selective dispersion of semiconducting arc-discharge SWNTs.

Optimization of capillary-channeled polymer (C-CP) fiber stationary phase extractions of proteins from MALDI-MS suppressing media

Solid phase extraction (SPE) is an essential component in many proteomic analyses involving matrix-assisted laser desorption/ionization mass spectrometry detection (MALDI-MS). Parametric variables affecting the efficiency of protein extractions from buffer (Tris–HCl) and urine media using a capillary-channeled polymer (C-CP) fiber stationary phase in a tip-based format are evaluated. Proteins are immobilized on to polypropylene (PP) C-CP fibers and eluted in organic solvents conducive to high analytical performance using a simple benchtop centrifuge to drive the fluids. Experimental variables, including elution solvent strength, aqueous wash volume, the interactive aspects of fiber tip length (2.5–10 mm), and loading and elution volumes, were evaluated to gain insights into fundamental processes and to optimize protein recoveries/analytical signals. Based on the MALDI-MS responses of the test proteins cytochrome c, lysozyme, and myoglobin, the optimized elution solvent was determined to be a 60 : 40 ACN–H2O mixture with 0.07% trifluoroacetic acid (TFA). It was determined that different aqueous wash volumes were required to flush test solution remnants, depending on the buffer concentration, concluding that a 100 μL wash was effective at concentrations of up to 1 M. Fiber tip length was explored to determine the limits of loading volume/protein mass for each bed size while efficiently extracting from the buffer environment. Interestingly, the shortest C-CP fiber tips provided the best efficiency, isolating nanogram levels of protein from 1 μL aliquots of sample. After optimization, a proof of practice experiment was performed to extract the three-protein suite (<5 μM of each) from a synthetic urine matrix. The previously undetected proteins could be readily distinguished with high spectral clarity due to the SPE procedure utilizing C-CP fiber packed micropipette tips.

An evaluation of platelet-rich plasma without thrombin activation with or without anorganic bone mineral in the treatment of human periodontal intrabony defects

The efficacy of platelet-rich plasma (PRP) in periodontal regeneration is not well understood and the definite clinical viability of blood derived platelets lacks clarity. Also, the use of thrombin for platelet activation is disputed. Hence, the purpose of this study was to evaluate the efficacy of blood derived platelets without thrombin activation, alone or in combination with bovine anorganic bone mineral (ABM), in the treatment of human periodontal intrabony defects. PRP was prepared using a simple tabletop centrifuge and activated using calcium chloride without the addition of thrombin. This PRP was used alone (in Group A) and in combination with bovine ABM (in Group B) in the treatment of human periodontal angular defects. Both the control and the test groups showed definite improvement in clinical parameters. On comparison, however, there was a statistically significant improvement in the probing pocket depths and relative attachment level in Group B over Group A at 3 and 6 months intervals, whereas at the end of 9 months this difference was not statistically significant. There was no statistically significant difference between the groups with respect to the relative defect depth. Within the limitations of this study and the type of PRP used, i.e. without thrombin mediated activation, it can be concluded that both PRP and PRP combined with bovine ABM results in significant clinical improvement. Albeit statistically insignificant, there is a preponderance of better clinical results with the addition of ABM to PRP. Further studies need to be carried out on a larger sample size to confirm the results of the present study.