Insights on the structural characteristics and molecular dynamic studies of methyl vanillin Schiff base bio-compounds.

A new crystalline form of Schiff base, N-cyclohexyl-1-(3,4-dimethoxyphenyl)methanimine (CHADMB) was obtained from methanolic solution of cylohexylamine and (methylvanillin) 3,4dimethoxybenzaldehyde. Single crystal X-ray diffraction study reveals that the compound crystallized in monoclinic crystal system with P21/c space group having four molecules per unit cell (Z = 4). Hirshfeld surface (HS) analysis and 2D fingerprint plots reveals that weak non-covalent interactions are responsible for crystal packing. The UV-Vis spectroscopy study reveals that the optical band gap of the compound is 4.25 eV. The dielectric properties were studied as a function of frequency at room temperature and the results show that these properties can be exploited for optoelectronic applications. Thermal stability of the compound is revealed by thermogravimetric and differential thermogravimetric analysis. The in vitro antimicrobial activity against Gram negative (E. coli and P. aeruginosa and Gram positive (S. aureus ) bacterial strains and two fungal strains (C. albicans and A. niger) were studied by agar well diffusion method. It is found that the Schiff base is inhibiting the growth of the tested species to varying degrees. Molecular docking studies indicate that alkyl-pi and pi-pi weak interactions enhance the binding affinity of Schiff base-protein complexes. Molecular dynamics study reveals interaction of CHADMB complexed with bacterial protein, EC showed maximum stability which is in agreement with experimental result.Communicated by Ramaswamy H. Sarma.

New crystalline form of (N-cyclohexyl-1-(3,4-dimethoxyphenyl)methanimine Schiff base is synthesized.Synthesized compound is characterized by elemental analysis, SXRD, Raman, FT-IR, Mass, ¹H and ¹³C NMR spectroscopy.Band gap of the compound is calculated from absorption data.The dielectric properties of the compound are tested.Biological activity of the compound is tested against three bacterial and two fungal strains.Molecular docking and molecular dynamics studies were carried out to study the interaction of synthesized compound with various bacterial and fungal proteins.

Endovascular Management of Mucormycotic Aneurysms of the Internal Carotid Artery in Post-COVID-19 Patients.

The repercussions of the coronavirus disease 2019 (COVID-19) are being felt throughout the world to this day. India is one such country ravaged by the second wave of the pandemic. Here, we report two cases of post-COVID-19 mucormycotic aneurysm of the internal carotid artery (ICA), which we believe are the first of their kind in the reported medical literature. A nasopharyngeal swab for reverse-transcriptase polymerase chain reaction of the severe acute respiratory syndrome coronavirus 2 was positive for both cases. After recovering from COVID-19, both patients developed signs and symptoms suggestive of mucormycosis, which were confirmed by a fungal smear. They were managed with liposomal amphotericin B (LAmB) and other adjunctive medicines. The first patient developed a massive bout of epistaxis during surgical debulking of his fungal mass. He underwent anterior nasal packing and emergency digital subtraction angiogram which revealed an aneurysm of the right ICA which was treated by coiling of the aneurysm and parent artery occlusion of the right ICA. The second patient had a history of post-COVID-19 mucormycosis which was managed by LAmB, surgical debulking, and posaconazole. He was not in regular follow-up and did not fully complete his antifungal therapy. Later, he presented with recurrent episodes of epistaxis followed by a massive bout of bleeding from both nostrils which upon evaluation revealed a thin-walled aneurysm of the left cavernous ICA. He was treated with flow diversion and coiling. Both patients responded well and the aneurysms were successfully excluded from the circulation. Their follow-ups were uneventful.

A Comparative Evaluation of Five Obturation Techniques in the Management of Simulated Internal Resorptive Cavities: An Ex Vivo Study.

BACKGROUND: Root resorption is the loss of dental hard tissues as a result of clastic activities. It might be broadly classified into external or internal resorption by the location of the resorption in relation to the root surface. the various techniques used these days for filling internal resorption include warm condensation, vertical condensation, core techniques, thermoplasticized gutta-percha, warm vertical compaction, and cold lateral condensation. OBJECTIVES: The aims and objectives of this study were to compare the quality of root fillings in artificially created internal resorption cavities filled with warm vertical compaction, lateral condensation, Obtura II along with System B, E and Q plus along with System B, and Thermafil, and to calculate the percentage of gutta-percha, sealer, and voids using an ImageJ software. RESULTS: Results between the warm vertical compaction (group I), lateral condensation (group II), Obtura II with System B (group III), E and Q plus with System B (group IV), and Thermafil (group V), group III showed the highest percentage of gutta-percha plus sealer and gutta-percha, and least number of voids, which was statistically significant (P < 0.000). CONCLUSION: It can be concluded that Obtura II along with System B was found to be the most suitable obturation technique for the management of teeth exhibiting internal resorption. Thermafil was found to give the poorest obturation quality when used to fill the teeth with internal resorption. Similarly, lateral condensation technique was observed to show maximum sealer and hence was not ideal for the management of internal resorptive cavities.

Clinical Efficacy of Subgingivally Delivered 1.2 mg Simvastatin in the Treatment of Patients with Aggressive Periodontitis: A Randomized Controlled Clinical Trial.

Simvastatin (SMV) is a specific competitive inhibitor of 3-hydroxy-2-methylglutaryl coenzyme A reductase that promotes bone formation. The present clinical trial was designed to investigate the effectiveness of 1.2 mg SMV as a local drug delivery system and as an adjunct to scaling and root planing (SRP) in the treatment of aggressive periodontitis (AgP). A total of 68 intrabony defects from 24 patients with AgP were treated either with 1.2 mg SMV gel or placebo gel. The subjects were randomly assigned to SRP + placebo (group 1; n = 12) or SRP + SMV (group 2; n = 12). Clinical parameters were recorded at baseline and at 3 and 6 months and included bleeding index, Plaque Index, probing depth (PD), and clinical attachment level (CAL). At baseline and after 6 months, radiologic assessment of bone defect fill was done. The mean decrease in PD at 6 months was 1.14 ± 0.04 mm and 3.78 ± 0.62 mm in groups 1 and 2, respectively. Significant gain in mean CAL was found between the groups (P < .05). Furthermore, significantly greater mean percentage of bone fill was found in group 2 (34.01%) compared to group 1 (2.62%). Locally delivered SMV provides a comfortable method to improve clinical parameters and promotes bone formation.

Dumbbell-Shaped Neurofibroma Over the External Ear.

Dumbbell-shaped swellings in neurofibroma have been commonly described in the spine, thorax, cranial cavity, and pelvis; however, dumbbell-shaped swellings in the peripheries are rare. Here, we report a dumbbell-shaped neurofibroma over the pinna in an 18-year-old female patient, its successful surgical management, and its association with Hashimoto thyroiditis. To the best of our knowledge, this is the first ever case to be reported of a dumbbell-shaped neurofibroma over the external ear and only the fourth case of neurofibromatosis type 1 (NF1) to be associated with Hashimoto thyroiditis.

Long-range force transmission in fibrous matrices enabled by tension-driven alignment of fibers.

Cells can sense and respond to mechanical signals over relatively long distances across fibrous extracellular matrices. Recently proposed models suggest that long-range force transmission can be attributed to the nonlinear elasticity or fibrous nature of collagen matrices, yet the mechanism whereby fibers align remains unknown. Moreover, cell shape and anisotropy of cellular contraction are not considered in existing models, although recent experiments have shown that they play crucial roles. Here, we explore all of the key factors that influence long-range force transmission in cell-populated collagen matrices: alignment of collagen fibers, responses to applied force, strain stiffening properties of the aligned fibers, aspect ratios of the cells, and the polarization of cellular contraction. A constitutive law accounting for mechanically driven collagen fiber reorientation is proposed. We systematically investigate the range of collagen-fiber alignment using both finite-element simulations and analytical calculations. Our results show that tension-driven collagen-fiber alignment plays a crucial role in force transmission. Small critical stretch for fiber alignment, large fiber stiffness and fiber strain-hardening behavior enable long-range interaction. Furthermore, the range of collagen-fiber alignment for elliptical cells with polarized contraction is much larger than that for spherical cells with diagonal contraction. A phase diagram showing the range of force transmission as a function of cell shape and polarization and matrix properties is presented. Our results are in good agreement with recent experiments, and highlight the factors that influence long-range force transmission, in particular tension-driven alignment of fibers. Our work has important relevance to biological processes including development, cancer metastasis, and wound healing, suggesting conditions whereby cells communicate over long distances.

Remodeling of fibrous extracellular matrices by contractile cells: predictions from discrete fiber network simulations.

Contractile forces exerted on the surrounding extracellular matrix (ECM) lead to the alignment and stretching of constituent fibers within the vicinity of cells. As a consequence, the matrix reorganizes to form thick bundles of aligned fibers that enable force transmission over distances larger than the size of the cells. Contractile force-mediated remodeling of ECM fibers has bearing on a number of physiologic and pathophysiologic phenomena. In this work, we present a computational model to capture cell-mediated remodeling within fibrous matrices using finite element-based discrete fiber network simulations. The model is shown to accurately capture collagen alignment, heterogeneous deformations, and long-range force transmission observed experimentally. The zone of mechanical influence surrounding a single contractile cell and the interaction between two cells are predicted from the strain-induced alignment of fibers. Through parametric studies, the effect of cell contractility and cell shape anisotropy on matrix remodeling and force transmission are quantified and summarized in a phase diagram. For highly contractile and elongated cells, we find a sensing distance that is ten times the cell size, in agreement with experimental observations.

Predictive maps for stochastic nonaffine stiffening and damage in fibrous networks.

The macroscopic responses of synthetic and natural filamentous networks are determined by a combination of microstructure and filament properties. Biofilament networks such as those of actin and fibrin have become vehicles for studying important concepts in mechanics such as rigidity percolation, linearity and nonlinearity, isotropy and anisotropy, affinity and nonaffinity, hardening and softening, bending and stretching transitions, etc. In this work, we consider generic fibrous network architectures to map out their mechanical responses over a wide range of filament properties. Using the finite element method, we perform two-dimensional simulations of discrete networks subjected to shear deformation. These simulations encompass stochastic effects arising from network topology (filament arrangement, orientation, and length distribution) and the thermally activated crosslink scission. We study the mechanics of these random networks up to a strain of 10%, including damage that is induced by crosslink scission. The response is nonlinear and the initial elastic modulus alone is not sufficient to give an understanding about the overall response. We show that the nonlinear elastic response of the network can be captured using a few parameters that depend on some well known length scales in network mechanics. For networks with filament density above the rigidity percolation threshold, by increasing filament density and bending stiffness, we observe a crossover from the bending dominated elastically compliant stiffening regime to a stretching dominated rigid nonstiffening regime. We show that in the bending dominated regime there are large deviations from the predictions of affine continuum theories. We also give a simple qualitative model for describing the contours of the incubation strain which marks the onset of damage in networks.

Differential roles of p16INK4A and p14ARF genes in prognosis of oral carcinoma.

BACKGROUND: Oral cancer patients are found to have poor clinical outcome and high disease recurrence rate, in spite of an aggressive treatment regimen. The inactivation of INK4A/ARF loci is reported to be second to p53 inactivation in human cancers. The purpose of this study was to assess the prognostic significance of the molecular aberrations in the INK4A locus for effective identification of aggressive oral carcinoma cases needing alternate therapy. MATERIALS AND METHODS: The study composed of 116 patients freshly diagnosed with oral carcinoma. The genetic and epigenetic status of the p16(INK4A) and p14(ARF) genes was evaluated. The relation between these genic alterations and different treatment end points, such as residual disease (initial response), disease recurrence, and overall survival, along with the standard clinical markers, were analyzed. RESULTS: 62% of the study cases had p16(INK4A) gene abnormalities, with deletion accounting for 33% and methylation for 29%. Alterations in p14(ARF) gene either by deletion (12%) and/or methylation (18%) were observed in 30% of the cases. p16(INK4A) deletion was associated with aggressive tumors, as evidenced by the nodal involvement of the disease. Low or absence of p16(INK4A) protein adversely affected the initial treatment response. Promoter methylation of p16(INK4A) was associated with increased disease recurrence and acts as an independent predictor for worse prognosis. Surprisingly, p14(ARF) methylation associated with lower recurrence rate in oral cancer patients with a good clinical outcome. Overall survival of these patients was associated with tumor size, nodal disease, and p16(INK4A) protein expression pattern. Our results indicate that p16(INK4A) and p14(ARF) alterations constitute a major molecular abnormality in oral cancer cases. CONCLUSION: The molecular profile of INK4A/ARF locus, both at DNA and protein level, could be used as a prognostic biomarker for assessing the aggressiveness of disease in oral carcinoma patients. The study further shows the opposing clinical effect of these two genes, transcribed from the same locus, in oral cancer patients.

Shape filtering for false positive reduction at computed tomography colonography.

In this paper, we treat the problem of reducing the false positives (FP) in the automatic detection of colorectal polyps at Computer Aided Detection in Computed Tomography Colonography (CAD-CTC) as a shape-filtering task. From the extracted candidate surface, we obtain a reliable shape distribution function and analyse it in the Fourier domain and use the resulting spectral data to classify the candidate surface as belonging to a polyp or a non-polyp class. The developed shape filtering scheme is computationally efficient (takes approximately 2 seconds per dataset to detect the polyps from the colonic surface) and offers robust polyp detection with an overall false positive rate of 5.44 per dataset at a sensitivity of 100% for polyps greater than 10 mm when it was applied to standard and low dose CT data.