Sharp Peak Research Articles

Modified stable methods and effect of artificial diffusion in the numerical study of viscoelastic fluid flow

The trace of the polymer conformation tensor in numerical simulations is bounded by applying a logarithmic transformation to the elastic force in the finitely extensible nonlinear elastic-Peterlin model. This method, called elastic stress logarithmic transformation (EL), is combined with the artificial diffusion (AD) and square-root conformation reformulation (SRCR) methods to establish EL-AD and EL-SRCR methods, respectively. The accuracy and stability of these methods have been investigated by conducting direct numerical simulations of viscoelastic laminar flows around a circular cylinder at a Reynolds number Re = 100, considering a wide range of rheological parameters: the maximum polymer extensibility L = 10 and 100, and the Weissenberg number Wi=1−80. Specifically, effects of artificial diffusion coefficients measured by dimensionless Schmidt number Scc=10−106 on the flow are studied. The results indicate that the EL method can effectively ensure the boundedness and accuracy of the conformation tensor trace, making the EL-AD method a valuable modification of the AD method for simulations with larger L and Wi. The impact of the polymer stress diffusion on the simulation is complex. It can stabilize the simulation by reducing sharp gradients and peak positions of elastic stress. However, inappropriate artificial diffusion coefficients lead to flow artifacts when L is large (L = 100). One consequence is an amplification of the solid-like phenomenon caused by polymer near the upstream stagnation point of the cylinder. Another consequence is an enhanced suppression of vortices by polymer downstream of the cylinder. The challenge in determining a suitable AD coefficient emphasizes the superiority of the EL-SRCR method in terms of stability and accuracy.

How do different feedstocks and pyrolysis conditions effectively change biochar modification scenarios? A critical analysis of engineered biochars under H2O2 oxidation

Biochar oxidation is known as a modification method to enhance the beneficial sorption characteristics of biochar. To explore this, a comparative physio-chemical analysis of non-oxidized and oxidized biochar with hydrogen peroxide (H2O2) was conducted using different feedstocks. Biochars were pyrolyzed at temperatures of 350, 450, and 550 °C and were derived from wheat straw, rye straw, wood residues, cherry stone, sewage sludge, and cattle manure, marked as BWS, BRS, BWR, BCS, BSS, and BCM. The pyrolysis temperature of 550 °C in BWS and BRS led to the formation of newly arranged vessels and regular pores scattered in their walls. X-ray photoelectron spectroscopy of wood-based biochars showed a notable increase in surface oxygen-contained functional groups for O-BWR350, O-BWR450, O-BWR550, O-BCS350, O-BCS450, and O-BCS550 with increased values by 6.5 %, 27.9 %, 42.3 %, 3.9 %, 31.2 %, and 52.4 % compared to their correspondent non-oxidized biochars. The sharp peaks of crystallization in non-oxidized biochars diminished after oxidation as detected by X-ray diffractometer analysis. Also, Cd removal efficiency in O-BCS550 (65 %) and O-BWR550 (69 %) appeared with outstanding results among all biochar types. Based on thermo-gravimetric analysis, the lowest and highest mass losses on average were related to BRS (22.5 %), and O-BCM (39.7 %). Also, the high heating value (HHV) analysis showed that BWR550 and BCS550 biochars had the highest HHV with 33.6 and 32.5 MJ kg−1, and O-BSS350 had the lowest value with 10.1 MJ kg−1. By taking feedstock degradability and pyrolysis temperature into account, this work presents a novel approach to maximize the benefits of H2O2-modified biochar. This will enable us to create a variety of engineered biochars in a clean and economical way as opposed to costly activation oxidants.

Influence of Mg doping on the structural and optical properties of manganese oxide (Mn2O3) nanoparticles

The work presents here the synthesis of pristine manganese oxide (Mn2O3) nanoparticles and magnesium (Mg) doped Mn2O3nanoparticles with the help of the chemical co-precipitation method. We have investigated the influence of Mg doping (9 wt%, 12 wt%, and 15 wt%) on the optical and structural properties of Mn2O3. The structural properties of undoped and doped Mn2O3 nanoparticles have been studied using X-ray Diffraction Spectroscopy (XRD). The numerous physiochemical bondings present within the prepared nanoparticles have been examined using Fourier Transform Infrared Spectroscopy (FTIR). Both photoluminescence (PL) and UV-Visible (UV-Vis) spectroscopy have been used to investigate the optical characteristics. All the measurements are done at room temperature. All of the samples’ absorption spectra have been investigated within the wavelength range of 200 to 800 nm. The UV-Vis absorption spectrum for pristine Mn2O3 nanoparticles shows a sharp peak at 289 nm. We have further determined the band gap of the prepared samples using Tauc’s equation. The pristine Mn2O3 exhibits a direct bandgap of 4.04eV. At an excitation wavelength of 320 nm, the prepared samples’ emission spectra have also been recorded.

X-ray Photoelectron Spectroscopy and Optical Studies of Assembled Gold Clusters

The electronic structures and optical properties of assembled gold nanoclusters prepared through wet chemical method have been investigated. The scanning electron microscopic analysis revealed gold clusters growing into beaded nanowires. The core level electronic states of the samples analyzed using X-ray Photoelectron spectroscopy, confirm the presence of gold. Further, the shift of core 4f orbitals towards higher energy indicates the interaction between Au and ligand in comparison with the bulk counterpart. The appearance of a sharp peak at 371 nm in the optical absorption spectrum refers to the excitonic transition between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) states. The luminescence peak observed at 403 nm and 615 nm may be due to the transitions between HOMO-LUMO gaps and the surface states and/or states originating from cluster-ligand interactions, respectively.

Impedance measurements on reflective surfaces: effect of nodes

The ISO 13472-2 standardizes the in-situ measurement of normal-incidence acoustic absorption of road pavements. The standard describes the use of the two-microphone method with an impedance tube specially configured for sealing against pavement surfaces. The method is of interest to the tire-pavement noise and vehicle pass-by noise communities. For roads constructed of dense graded asphalt, for example, pass-by noise test tracks conforming to ISO 10844, the pavement is a highly reflective surface. Under this measurement condition, the acoustic field within the tube develops nodes at one or the other microphone positions at characteristic frequencies. These nodes present as sharp peaks and valleys in the two-microphone transfer function. Such narrow bandwidth features are susceptible to measurement error, in particular, signal processing leakage as evidenced by significant drops in the coherence function at the frequencies of the nodes. In this paper we study the nature of the nodes and the effect they have on the two-microphone transfer function and coherence function. We further investigate how different formulations of the transfer function affect the overall 1/3rd octave band accuracy. The effect of the number of averages on both coherence and leakage error is assessed. The potential to solve this leakage effect by switching microphones to other positions is evaluated in relation to a procedure with two fixed microphones. It was concluded that although shifting microphone positions does have advantages in terms of preventing leakage, the mandatory application of a reference measurement reduces the overall error. Finally, recommendations for improving the procedure in ISO 13472-2 are formulated.

The Characteristic of Ph-Sensing of Potentiometric on Zinc Oxide and Aluminium-Doped Zinc Oxide Nanostructures

Numerous investigations have been conducted to increase the sensitivity and stability of metal oxide semiconductors as pH-sensing membranes. This paper will describe the pH sensing and characterisation of zinc oxide (ZnO) and aluminium-doped zinc oxide (ZnO:Al) as potentiometric pH sensors. The hydrothermal technique was used to grow ZnO and ZnO:Al thin film nanostructures with doping concentrations of 1, 3, and 5 at% Al on the cleaned ITO substrates. The pH potentiometric sensing was performed in a wide pH range of 4-12 and produced sensitivity, including stability of the nanostructures. The prepared samples were also characterized by X-ray diffraction analysis (XRD), field effect scanning electron microscope (FESEM), and energy dispersive X-ray (EDX) to explore the influence of aluminium concentration on structural and morphology characteristics and then prepared as electrodes for pH sensing. From the XRD result, the sharp peaks and high peak intensities demonstrated well crystalline of the synthesized ZnO nanorods. Furthermore, the FESEM shows the growth of array nanorods perpendicular over the surface of ITO. The sensitivity of the pH sensor with 3 at% ZnO:Al exhibits higher sensitivity (43.80 mV/pH) and larger linearity (0.9507).

Determination of the characteristic impedance and the complex wave number by five different approaches

This study presents several methods to determine the characteristic impedance and the complex wave number of porous materials. These methods include the two-cavity method by Utsuno et al., the two-thickness method by Dunn and Davern, the four-microphone transfer-matrix method by Song and Bolton, the empirical method by Miki and theoretical calculation by the inverse method of Johnson-Champoux-Allard (JCA) model. Glass wool and polyester materials are used to compare different approaches. The results indicate a clear correlation among all methods. The theoretical calculation based on the inverse method of the JCA model can predict well without direct measurement of the non-acoustical parameters. However, there are disadvantages to several methods including sharp peaks in some frequency ranges for the two-cavity method, data fluctuation at low frequency for the four-microphone method, and inaccuracy in predicting the characteristic impedance of thick materials at middle and high frequencies for the two-thickness method. The results imply that the inverse method of the JCA model is a reliable method to predict the characteristic impedance and the complex wave number with comparable accuracy to traditional experimental methods.

High Values of the Arctic Amplification in the Early Decades of the 21st Century: Causes of Discrepancy by CMIP6 Models Between Observation and Simulation

AbstractArctic Amplification (AA) in the first decade of the 21st century has reached values between 4 and 5, with a subsequent decrease to current values of about 3.6, while the value was from 2 to 3 during the twentieth century. The ensemble mean of the CMIP6 models has difficulty in reproducing the recently observed high values of the AA. In this report, we identify the main reason for this difficulty to be the CMIP6 models overestimate of the mean global temperature trend since about 1990. The largest values of the AA are observed in winter and spring. A sharp AA peak in 1987 spring was caused by a peak in the Arctic temperature trend occurring at the same time as a dip in the trend of mean global temperature. The winter AA has increased almost monotonically since 1990. Dividing the AA between the Arctic land and ocean areas shows that the ocean area makes a larger contribution to the AA. Our future projection of the AA suggests an increasing AA for about the next decade, followed by a slow decrease to about 3.5 in the 2050s.

Unraveling the Potential of Organic Oregano and Tarragon Essential Oils: Profiling Composition, FT-IR and Bioactivities

Oregano and tarragon are widely cultivated culinary herbs used for food seasoning, having familiar characteristic aromas appreciated by the wide public. The aim of this research was to characterize essential oils (EOs) from locally sourced organic oregano and tarragon (Cluj, Romania) and study their bioactivity potential. Results showed that oregano EO had a sesquiterpene dominant profile responsible for strong bands between 2800 and 3000 cm−1 on the Fourier transform infrared spectroscopy (FT-IR) spectrum and a composition consistent with reports from similar climatic regions. The tarragon EO profile was defined by phenylpropanoids responsible for the strong sharp peaks between 1000 and 1600 cm−1 on the FT-IR spectrum. In oregano EO, 22 compounds were identified with β-caryophyllene as a major constituent. In tarragon EO, 20 compounds were identified with eugenol as a major constituent. Oregano EO had a stronger antibacterial effect against both Gram-negative and Gram-positive bacterial strains, while tarragon EO had a slightly stronger cytotoxic effect on three types of cancer cell lines tested (skin melanoma, prostate carcinoma, and colorectal adenocarcinoma). It was concluded that, given the fact that a sufficient supply of high-quality plant material can be available for EO extraction, culinary herbs can become reliable candidates for many industries without the risk of discontinued supply. Therefore, research aiming to widen their potential applications is welcome and worth pursuing.

An innovative combination of Box-Behnken design and ecofriendly approaches for the simultaneous determination of aspirin, clopidogrel, atorvastatin and rosuvastatin in their fixed-dose combination tablets

Three-levels Box-Behnken design was used in the experimental design approach for the optimization of chromatographic parameters to achieve the optimum resolution and sharp peak shape within a reasonable run time. A method that is sensitive, reliable, and selective was constructed and validated for the simultaneous measurement of a combination therapy that contains blood-thinning and cholesterol-lowering compounds. The four cited drugs namely, aspirin (ASP), clopidogrel (CLP), atorvastatin (ATV) and rosuvastatin (ROS) were estimated in bulk and in pharmaceutical dosage forms in line with International Council for Harmonization guidelines. The separation was done utilizing Kinetex 2.6 C18 column (100 mm, 4.6 mm, 5 m) and RP-HPLC with diode array detector. The separation of the cited drugs and the degradation product of ASP was achieved with mobile phase composed of acetonitrile: KH2PO4 buffer in a gradient mode with pH 3.2 at room temperature. The four drugs were linear over the concentration range (0.05–50 µg/mL). The technique is feasible to be used in quality control laboratories. To picture the green profile of the developed method, four greenness assessment tools were applied. National environmental methods index (NEMI), analytical eco-scale assessment (ESA), green analytical procedure index (GAPI) and analytical greenness metric (AGREE) are the most widely used metrics. They were employed to evaluate the greenness profile of the proposed method and to perform a detailed greenness comparison between the developed method and some of the reported methods for the determination of the investigated drugs. The developed method was found to be relatively green with 0.54 AGREE score.

Mixed Nanosphere Assemblies at a Liquid-Liquid Interface.

The in-plane packing of gold (Au), polystyrene (PS), and silica (SiO2) spherical nanoparticle (NP) mixtures at a water-oil interface is investigated in situ by UV-vis reflection spectroscopy. All NPs are functionalized with carboxylic acid such that they strongly interact with amine-functionalized ligands dissolved in an immiscible oil phase at the fluid interface. This interaction markedly increases the binding energy of these nanoparticle surfactants (NPSs). The separation distance between the Au NPSs and Au surface coverage are measured by the maximum plasmonic wavelength (λmax) and integrated intensities as the assemblies saturate for different concentrations of non-plasmonic (PS/SiO2) NPs. As the PS/SiO2 content increases, the time to reach intimate Au NP contact also increases, resulting from their hindered mobility. λmax changes within the first few minutes of adsorption due to weak attractive inter-NP forces. Additionally, a sharper peak in the reflection spectrum at NP saturation reveals tighter Au NP packing for assemblies with intermediate non-plasmonic NP content. Grazing incidence small angle X-ray scattering (GISAXS) and scanning electron microscopy (SEM) measurements confirm a decrease in Au NP domain size for mixtures with larger non-plasmonic NP content. The results demonstrate a simple means to probe interfacial phase separation behavior using in situ spectroscopy as interfacial structures densify into jammed, phase-separated NP films.

Ferroelectric-driven disorder inducing transition of bosonic insulator–superconductor in TiN/Hf0.5Zr0.5O2 heterojunction

Unique quantum states induced by disorders can be characterized by quantum phase transitions in many-body systems. In this study, we experimentally observed a sharp resistance peak near the superconducting transition in superconductor/ferroelectric TiN/Hf0.5Zr0.5O2 heterostructures. The peak is attributed to the disorder introduced by ferroelectric fluctuations within the empirical model of metal–boson insulator–superconductor transitions. By modulating the quantum phase transitions in superconductivity and competing with the disorder through ferroelectric polarization, we provide a versatile platform for investigating the influence of ferroelectric materials on superconducting states.

A comprehensive compatibility study of ganciclovir with some common excipients

Objectives: The aim of the present study is to illustrate compatibility testing of ganciclovir (GCV) with some common excipients that would be used to manufacture solid oral dosage forms. Different spectroscopy techniques were utilized to see the interaction of GCV with excipients such as lactose, microcrystalline cellulose (MCC), magnesium stearate, and talc, and dicalcium phosphate. Further, a molecular docking study was also done to know the interaction of GCV with excipients. In vitro study of a physical mixture of GCV with excipients was performed to get the release of drug. Material and Methods: A number of analytical techniques (differential scanning calorimetry [DSC] using DSC-Q20, TA instruments, Fourier-transform infrared spectroscopy [FTIR] spectroscopy using Spectrum RX 1, nuclear magnetic resonance [NMR] using Bruker Advance Neo 500 MHz NMR spectrometer, etc.) have been used to explore the drug-excipient compatibility. Further, a suspected interaction was evaluated by thin-layer chromatography (TLC). In vitro dissolution studies in different sets of experiments were accomplished to determine the influence of hydrophobic and hydrophilic attributes of excipients (MCC, lactose, dicalcium phosphate, and talc) on the dissolution profile of GCV using USP1-type dissolution apparatus. Furthermore, in silico molecular docking studies were also performed to evaluate any probable molecular interactions among drugs and excipients using Auto Dock VINA 1.2.0 software and GROMACS 5.0 software. Results: Comparing FTIR and 1H NMR spectra of GCV and physical mixtures of GCV and excipients, no significant deviation of characteristic peaks in infrared spectroscopy and 1H NMR signals was observed. The DSC of GCV showed two sharp endothermic peaks at 238.82°C and 255°C. The endothermic peak of GCV in DSC thermogram of physical mixtures was observed in nearly the same position except with lactose and dicalcium phosphate. A slightly deviated peak of GCV with a physical mixture of drug and lactose and dicalcium phosphate indicated that there were suspected interactions between the drug with lactose and dicalcium phosphate. These interactions were evaluated by thin-layer chromatography (TLC) and it confirmed that there was no interaction between drugs and excipients. In vitro dissolution studies determined the influence of hydrophobic and hydrophilic attributes of excipients on the dissolution profile of GCV. The physical mixture of GCV with MCC displayed a maximum amount (66.48%) of drug release in 10 min. On the other hand, a physical mixture of GCV with talc showed a minimum amount (12.08%) of drug release in 10 min. Docking study predicted that the number of interactions were more between GCV and lactose (four nos.) in comparison to GCV and MCC (two nos.). This interaction supported the in vitro drug release of a physical mixture of GCV with MCC which was higher than a mixture of GCV with lactose. Conclusion: Compatibility testing of GCV with used excipients by analytical techniques confirmed that GCV should be compatible with used excipients. Drug dissolution of GCV and physical mixture of MCC exhibited the maximum amount of drug release whereas a mixture of GCV with talc released the minimum amount of drug for both short (10 min.) and long (60 min.) periods. Docking studies disclosed that the lactose complex showed less deviation with less root mean square deviation value in comparison to the microcrystalline complex. Thus, the lactose complex has more hydrogen bonds and it was more stable as compared with the MCC complex. GCV indicates that the total energy of the MCC complex is less than that of the lactose complex. This indicates that GCV is more soluble when combined with the microcrystalline complex. Therefore, GCV and used excipients could be used for solid dosage formulations.

Scintillation light yield of Tb-doped Lu2O3 single crystals

The photoluminescence and radioluminescence properties of Tb-doped Lu2O3 (Lu2O3:Tb) single crystals were assessed for scintillator applications. Lu2O3:Tb exhibits several sharp peaks at 490, 540, 590, and 620 nm attributed to Tb3+, and the decay curves show the typical decay time for Tb3+ in millisecond range. The decay decreases with increasing dopant concentration owing to concentration quenching. Energy distributions under 137Cs γ-rays demonstrate that the 0.1 % Tb-doped Lu2O3 exhibits the highest scintillation light yield (75,000 photons/MeV) among the samples.

Optimizing the performance of (Sb0.2Sn0.8)0.5(S0.9Se0.1)0.5 crystal-based self-powered photodetectors

The need to develop electronic systems capable of functioning without an external power source is an utmost priority, especially in the pursuit of self-powered photodetection. Through the direct vapor transport (DVT) method, we have synthesized a single crystal of the quaternary compound (Sb0.2Sn0.8)0.5(S0.9Se0.1)0.5 for self-driven photodetectors. The crystal's elemental composition was ascertained via energy-dispersive X-ray analysis (EDX), along with Field emission scanning electron microscopy (FESEM) provided insight into its surface morphology. The orthorhombic crystal system of the grown sample has been validated by a powder X-ray diffractometer (XRD). The regular spot pattern of SAED and the well-defined sharp peaks observed in the XRD graph collectively indicate the crystal's pronounced crystalline quality. The lattice parameters closely resemble the reported data. A UV–VIS-NIR spectrometer was utilized to deduce a direct optical band gap of 1.49 eV. Raman spectroscopy was used to examine different phonon modes. We analyzed its pulsed photo response by subjecting the grown crystal to different wavelengths and varying intensities of white light at self-biased mode and by applying 1 V bias. Our analysis enabled us to determine favourable photodetection parameters.

Machine learning molecular dynamics reveals the structural origin of the first sharp diffraction peak in high-density silica glasses

The first sharp diffraction peak (FSDP) in the total structure factor has long been regarded as a characteristic feature of medium-range order (MRO) in amorphous materials with a polyhedron network, and its underlying structural origin is a subject of ongoing debate. In this study, we utilized machine learning molecular dynamics (MLMD) simulations to explore the origin of FSDP in two typical high-density silica glasses: silica glass under pressure and permanently densified glass. Our MLMD simulations accurately reproduce the structural properties of high-density silica glasses observed in experiments, including changes in the FSDP intensity depending on the compression temperature. By analyzing the simulated silica glass structures, we uncover the structural origin responsible for the changes in the MRO at high density in terms of the periodicity between the ring centers and the shape of the rings. The reduction or enhancement of MRO in the high-density silica glasses can be attributed to how the rings deform under compression.

Assessment of the biointeractivity of a novel vital pulp therapy agent derived from eggshell biowaste: An invitro study.

This study aimed to assess the calcium (Ca2+) and hydroxyl (OH-) ion-releasing ability, namely the biointeractivity of eggshell-derived hydroxyapatite (ESDHA) in comparison with mineral trioxide aggregate (MTA) and calcium hydroxide (CH). ESDHA, MTA and CH samples (n = 10; 8 × 1.6 mm) were immersed in 10 mL of deionised water (37°C, pH 6.8). Ca2+ and OH- ion releases were detected in 1, 7 and 21 days. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses were also conducted. IBM SPSS 20.0 was used for statistical analyses. The cumulative Ca2+ ions (56.22 ± 11.28 ppm) were detected as most significant in ESDHA (day 21; p < 0.05). The OH- ion values of the ESDHA group were statistically higher than MTA and CH (days 1 and 7; p < 0.05). ESDHA and CH showed a similar pattern with sharp peaks in Ca2+, oxygen and carbon elements. ESDHA being a sustainable material with a high ion-releasing ability may be a preferable alternative to the commercial vital pulp therapy agents.

Synthesis of Defective Wheel‐Shaped Nanographdiynes

AbstractThe synthesis and optical properties of wheel‐shaped nanographdiynes that has lost some butadiyne spokes were reported. These defective wheel‐shaped nanographdiynes possess butadiyne‐bridged metacyclophanes with para‐bis(phenylbutadiynyl)‐benzene units as the axis. The optimized geometries of the defective wheel‐shaped nanographdiynes along with their vibrational spectra, HOMO and LUMO orbitals were calculated at B3LYP/6‐311G(d,p) level. HOMO and LUMO orbitals are delocalized mainly over the para‐bis(phenylbutadiynyl)‐benzene axis, with weak contribution from the attached ethynyl units. The π‐conjugation extension and quantity increase of the para axis influenced the optical properties of these graphdiyne substructures, leading to the change of bandgap from 2.88 eV to 2.56 eV as reflected by optical spectroscopy. The defective wheel‐shaped nanographdiynes lost the characteristic intensive sharp absorption peak at low energy region, which indicated that the fusion of adjacent dehydrobenzo [18] annulenes are crucial for the bulk properties of graphdiyne.

Synthesis and Photodegradation of Bi2O3 and Pb-Bi2O3 Nanoparticles and Their Kinetic Study

The green synthesis method synthesized the bismuth oxide and lead-doped bismuth oxide nanoparticles using Ferula Asafoetida leaves extract. The lead-doped bismuth oxide showed greater degradation efficiency than undoped bismuth oxide. This greater efficiency was due to decreases in the band gap energy between the valence band and the conduction band of the metal oxide and reduced the chances of electron-hole pair recombination with the metal oxide catalyst. The synthesized nanoparticles were characterized by TGA, SEM, FT-IR, EDX, XRD, and UV- visible Spectrometer. XRD diffraction of Bi2O3 nanoparticles reflected a strong and sharp peak at 32.8˚ shows that Bi2O3 nanoparticles are in crystalline phase. The crystallite size of Bi2O3 nanoparticles is 13.433 nm, and Pb-doped Bi2O3 is 9.6 nm, calculated from the Debye-Scherrer equation. The synthesized Bi2O3 nanoparticles are round in shape with average size of ~ 90-100 nm While Pb doped Bi2O3 is ~ 75 f- 100 nm. The EDX spectra showed no additional peak for any impurities. The degradation rate of Malachite Green dye (MG) increased with the increase in contact time and temperature, while it decreased with increasing dye initial concentration and pH. Initially, the degradation efficiency of the bismuth oxide catalyst is increased with increasing catalyst amount, but after a certain amount of catalyst, it started decreasing as the catalyst amount was further increased. The irradiation time on photodegradation is deliberate, keeping other parameters steady at catalyst quantity 0.01 g at specific reaction conditions. Moreover, the dye showed an increase in degradation at 50 oC. The utmost degradation of 92% was observed for lead-doped bismuth oxide (Bi2O3) and 76% for undoped bismuth oxide (Bi2O3).

The importance of BMPs and TGF-βs for endochondral bone repair – A longitudinal study in hip arthroplasty patients

IntroductionOsseointegration of hip implants, although a decade-long process, shows striking similarities with the four major phases of endochondral bone repair. In the current study we investigated the spatiotemporal involvement of bone morphogenic proteins (BMPs) and transforming growth factor betas (TGF-βs) throughout the process of bone repair leading to successfully osseointegrated hip implants. Materials and methodsTwenty-four patients that had undergone primary total hip arthroplasty (THA) due to one-sided osteoarthritis (OA) were investigated during a period of 18 years (Y) with repeated measurements of plasma biomarkers as well as clinical and radiological variables. All implants were clinically and radiographically well anchored throughout the follow-up. Eighty-one healthy donors divided in three gender- and age-matched groups and twenty OA patients awaiting THA, served as controls. Plasma was analyzed for BMP-1, -2, -3, -4, -6, -7 -9 and TGF-β1, -β2, -β3 by use of a high-sensitivity and wide dynamic range electrochemiluminescence technique allowing for detection of minor changes. ResultsSpatiotemporal changes during the follow-up are presented in the context of the four phases of endochondral bone repair shown in earlier studies and transposed to the current study based on similarities in biomarker responses. Phase 1: Primary proinflammatory phase lasting from surgery until day 7, Phase 2: Chondrogenic phase from day 7 until 18 months postsurgery, Phase 3: Secondary proinflammatory and cartilage remodeling phase lasting from 18 months until 7Y, Phase 4: coupled bone remodeling from 7Y until 18Y postsurgery. BMP-1 increased sharply shortly after surgery and remained significantly above healthy during the chondrocyte recruitment, proliferation, and hypertrophy phases with a subsequent return to control level at 5Y postsurgery. BMP-2 was above healthy controls before surgery and 1 day after surgery before decreasing to control level and remaining there throughout the follow-up. BMP-3 was at control level from presurgery until 6M after surgery when it increased to a peak at 2Y during the cartilage hypertrophy phase followed by a gradual decrease to control level at 10Y during the phase of bone formation. In the following, BMP-3 decreased below controls to a nadir 15Y postsurgery during coupled bone remodeling. BMP-4 was at control level from presurgery until 10Y postsurgery when it increased to a sharp peak at 15Y after surgery followed by a return to the level of healthy at 18Y. BMP-6 did not differ from healthy during the follow-up. BMP-7 was at control level from presurgery until 1Y postsurgery before gradually increasing to a peak at 10Y during the early phase of osteogenesis with a gradual return to control level at 18Y during the phase of coupled bone remodeling. BMP-9 was above OA before surgery followed by a decrease to basal level on day 1 after surgery and a renewed increase to a plateau above controls lasting from 6 W until returning to the level of healthy at 18Y postsurgery, i.e., throughout the phases of cartilage formation, cartilage hypertrophy and remodeling, bone formation and coupled bone remodeling. TGF-β1 was above controls presurgery before decreasing to baseline shortly after surgery followed by a renewed increase at 6 M to a peak at 2Y during cartilage hypertrophy/remodeling followed by a gradual return to baseline at 10Y during early osteoblastogenesis. TGF-β2 was at control level from presurgery until the phase of cartilage remodeling at 5Y when it increased sharply to a peak at 7Y with a gradual return to baseline at 18Y postsurgery. TGF-β3 remained at control level throughout the study. ConclusionThis study shows that the involvement of BMPs and TGF-βs in endochondral bone repair is a process of stepwise recruitment of individual biomarkers characterized by distinct, yet overlaping, spatiotemporal patterns that extend from the early phase of pre-chondrocyte recruitment until the late phase of coupled bone remodeling.