Silver Abietate and β-Cyclodextrin Inclusion Complex Doped Poly(vinyl alcohol) Nanowebs

In this study, guesthost inclusion complexes of silver abietate with β-cyclodextrin were prepared by kneading and physical mixing techniques, and analyzed via fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analyser (TGA). The 1:1 and 1:2 stoichiometry of the guesthost were prepared. Obtained FTIR and TGA results showed that formation of silver abietate:β-cyclodextrin (Ag-A:β-CD) inclusion complexes occurred at a mass ratio of both 1:1 and 1:2. Furthermore, prepared Ag-A:β-CD (1:2) inclusion complex was doped in Poly(vinyl alcohol) nanofibers during electrospinning process for obtaining nanowebs. The formation of nanowebs were investigated under scanning electron microscope (SEM), X-Ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analyser (TGA). The results confirmed Ag-A:β-CD inclusion complex containing Poly(vinyl alcohol) (PVA) nanoweb production.

Viscoelastic Properties and Thermal Stability of Nanohydroxyapatite Reinforced Poly-Lactic Acid for Load Bearing Applications

We studied the reinforcing effects of treated and untreated nanohydroxyapatite (NHA) on poly-lactic acid (PLA). The NHA surface was treated with three different types of chemicals; 3-aminopropyl triethoxysilane (APTES), sodium n-dodecyl sulfate (SDS) and polyethylenimine (PEI). The nanocomposite samples were prepared using melt mixing techniques by blending 5 wt% untreated NHA and 5 wt% surface-treated NHA (mNHA). Based on the FESEM images, the interfacial adhesion between the mNHA filler and PLA matrix was improved upon surface treatment in the order of mNHA (APTES) > mNHA (SDS) > mNHA (PEI). As a result, the PLA-5wt%mNHA (APTES) nanocomposite showed increased viscoelastic properties such as storage modulus, damping parameter, and creep permanent deformation compared to pure PLA. Similarly, PLA-5wt%mNHA (APTES) thermal properties improved, attaining higher Tc and Tm than pure PLA, reflecting the enhanced nucleating effect of the mNHA (APTES) filler.

Effect of Mixing and Impression Techniques Using Vinyl Polysiloxane (VPS) on the Accuracy of Fixed Partial Dentures

Two critical factors that influence the accuracy of an impression include the proper manipulation of the impression materials and the technique used to make the impression. The purpose of this study was to clinically evaluate the effect of different mixing techniques on the accuracy of vinyl polysiloxane (VPS) impressions by assessing metal framework fit of fixed partial restorations. The study included 92 consecutive patients diagnosed with partial edentulism and treated with fixed partial denture restorations. The mixing technique was one of the two following mixing methods: hand mixing technique (45 patients), with the putty material mixed according to the manufacturer’s instructions; or mechanical mixing technique (47 patients), with the putty material mixed by a Pentamix device. Under both mixing methods, vinyl polysiloxane was used as the impression material. Two impression techniques were randomly used by the operators (One/Two-stage putty –wash impression techniques). The accuracy of the metal framework restorations was tested clinically and radiologically, resulting in significant statistical difference (p = 0.04) between different mixing techniques. The mechanical mixing produced more accurate restorations (metal framework misfit only in 14.9% of patients vs. hand mixing 31.1%). Regarding the impression techniques, the two-stage impression technique was found to be significantly more accurate (p = 0.04), resulting in 14.6% ill-fitted metal frameworks vs. 31.8%, in the one-stage technique. It can be concluded that mechanical mixing yields more accurate impressions leading to more accurate restorations, especially when combined with two-stage impression technique.

Nanostructured Strontium-Doped Calcium Phosphate Cements: A Multifactorial Design

Calcium phosphate cements (CPCs) have been extensively studied in last decades as nanostructured biomaterials for the regeneration of bone defects, both for dental and orthopedic applications. However, the precise control of their handling properties (setting time, viscosity, and injectability) still represents a remarkable challenge because a complicated adjustment of multiple correlated processing parameters is requested, including powder particle size and the chemical composition of solid and liquid components. This study proposes, for the first time, a multifactorial investigation about the effects of powder and liquid variation on the final performance of Sr-doped apatitic CPCs, based on the Design of Experiment approach. In addition, the effects of two mixing techniques, hand spatula (low-energy) and planetary shear mixing (high-energy), on viscosity and extrusion force were compared. This work aims to shed light on the various steps involved in the processing of CPCs, thus enabling a more precise and tailored design of the device, based on the clinical need.

Mechanical and Mesoscale Analyses of Cement Stabilized Macadam Prepared by Vibratory and Nonvibratory Mixing Techniques

The objective of this study is to analyze the effects of mixing techniques on the mechanical behavior and meso-structure of cement-treated aggregate. Different specimens were prepared by vibratory and nonvibratory mixing techniques. X-ray CT scans were performed to illustrate the distribution of cement mortar on aggregate. The strength, modulus, and fatigue tests under different stress states were tested to reveal the impacts of mixing techniques. Then, the relationships between strengths and loading rates and that between moduli and stress levels were established. Hereafter, the S-N fatigue equation that modified with stress ratio related to loading rates was used to describe the fatigue performance. The results indicate that the cement mortar of specimens prepared by vibratory mixing was well-distributed on aggregates. The strength, modulus, and fatigue life of the specimens prepared by vibratory mixing were higher under the test condition threshold. Moreover, the growth rate of strength and modulus with loading for specimens prepared by vibratory mixing was slightly larger than that for specimens prepared by nonvibratory mixing. Compared with the cement-treated aggregates specimens prepared by nonvibratory mixing, the fatigue life of cement-treated aggregates specimens prepared by vibratory mixing had more stable stress sensitivity.

Evaluating Mixed Methods Research Integration Quality in Three Top Journals of Higher Education

Mixed methods research (MMR) has been adopted in a variety of disciplines, including health science, social studies, psychology, early childhood, and business. More recently, higher education researchers adopted this methodology, but with limited evaluation on the quality of published mixed methods research. To enhance researchers’ understanding of using MMR, we developed a 4-dimension codebook and reviewed 14 recently published mixed methods research articles that were published in 3 top journals in higher education. We found that researchers used 3 effective strategies to approach integration: (a) using a mixed methods research question to guide the mixed methods (MM) design, (b) using effective mixed methods sampling strategies to collect different types of data for the purpose of integration, and (c) using mixing techniques to interpret results for optimal maximum integration. Apart from the 3 effective integration strategies, a few insufficiencies have been singled out: (a) infrequent use of MM terminologies in the article title, (b) limited familiarity with MM data mixing strategies, and (c) non-optimal reporting of MM results. At the end, we synthesized the useful integration strategies and developed a checklist for higher education researchers to design high-quality mixed methods research studies.

Preparation of Silver Cyclohexane di Carboxylate: Β-cyclodextrin Inclusion Complexes and Their Use in the Production of Poly(vinyl alcohol) Nanowebs

In this study, guest:host inclusion complexes of silver cyclohexane di carboxylate (Ag-CdC) with β-cyclodextrin were prepared by kneading and physical mixing techniques, and analyzed via Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analyser (TGA). The 1:1 and 1:2 stoichiometry of the guest:host were prepared. Obtained FTIR and TGA results showed that formation of silver cyclohexane di carboxylate (Ag-CdC): β-cyclodextrin (β-CD) inclusion complexes occurred at a mass ratio of both 1:1 and 1:2. Furthermore, these prepared inclusion complexes were doped in poly(vinyl alcohol) nanofibers during electrospinning process for obtaining nanowebs. The formation of nanowebs were investigated with scanning electron microscopy (SEM). Besides, FTIR and TGA analysis were also carried out. Results showed that both inclusion complex preparation and inclusion complex added PVA nanowebs production were successful.

DIFFERENT MODERN TECHNIQUES USED IN CHURNA KALPANA: A REVIEW

To prepare any formulation in bulk quantity it needs a machine. The machines which manufacture the formulations in a bulk quantity will work on the basis of modern techniques. These techniques can be adopted to prepare different dosage forms through their method of preparations. Churna is also one among the different dosage forms which is having versatile usage and need to be prepared in bulk quantity. To achieve this, different modern methods like size reduction, size separation and mixing of powders and techniques viz. cutting, compression, impact, attrition and combined effect of impact and attrition are adopted, along with this sieving and mixing techniques are also adopted. To assure the quality of churna kalpana physico chemical analysis should be done like fineness of Particles, Presence of Heavy Metals, Test for microbial contamination etc.

The Catalytic Cycle of the Antioxidant and Cancer-Associated Human NQO1 Enzyme: Hydride Transfer, Conformational Dynamics and Functional Cooperativity

Human NQO1 [NAD(H):quinone oxidoreductase 1] is a multi-functional and stress-inducible dimeric protein involved in the antioxidant defense, the activation of cancer prodrugs and the stabilization of oncosuppressors. Despite its roles in human diseases, such as cancer and neurological disorders, a detailed characterization of its enzymatic cycle is still lacking. In this work, we provide a comprehensive analysis of the NQO1 catalytic cycle using rapid mixing techniques, including multiwavelength and spectral deconvolution studies, kinetic modeling and temperature-dependent kinetic isotope effects (KIEs). Our results systematically support the existence of two pathways for hydride transfer throughout the NQO1 catalytic cycle, likely reflecting that the two active sites in the dimer catalyze two-electron reduction with different rates, consistent with the cooperative binding of inhibitors such as dicoumarol. This negative cooperativity in NQO1 redox activity represents a sort of half-of-sites activity. Analysis of KIEs and their temperature dependence also show significantly different contributions from quantum tunneling, structural dynamics and reorganizations to catalysis at the two active sites. Our work will improve our understanding of the effects of cancer-associated single amino acid variants and post-translational modifications in this protein of high relevance in cancer progression and treatment.