Search results for “Stabilization

About 12 results in articles

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12 articles
Antioxidant Activity Open Access

Antioxidant Activity of Pod Coat Extracts of Pigeon Pea (Cajanus Cajan L.) and Their Efficacy in Stabilization of Soybean Oil

Oct 2021 DOI 10.14302/issn.2471-2140.jaa-21-3960

When lipids are exposed to heat, light and oxygen, it leads to oxidation. The addition of antioxidants is required to preserve colour, flavour and vitamin destruction. Present study was, therefore, planned to investigate pod coat of pigeon pea as possible sources of natural antioxidants and to assess their efficacy in stabilization of crude soybean oil during normal storage (28 days at 50°C). Study revealed that acetone pod coat extract of pigeon pea showed richness in total phenolics (17.72 mg/g), flavonoids (9.00 mg/g) and tannins (2.21 mg/g) while the extract of ethyl acetate was found enriched in tocopherols content (9.56 mg/g). The IC50 value of acetone extract was found to be lowest, exhibited potent antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric thiocyanate (FTC) methods. After adding synthetic and natural antioxidants in oil, Peroxide, p-Anisidine, Thiobarbituric acid value, Conjugated dienes, trienes and free fatty acids content were measured every 4 days. Acetone pod coat extract (2000ppm) of pigeon pea gave strong antioxidant efficacy in stabilization of crude soybean oil and hence could be recommended as natural antioxidants for food applications.The research explored the possibility of using pod coat of pigeon pea as imminent sources of green antioxidants and to evaluate their efficacy in stabilization of crude soybean oil.

Ophthalmic Science Open Access

Conjunctival Resection for Mooren's Ulcer Refractory to Medical Therapy: A Case Report

Jan 2026 DOI 10.14302/issn.2470-0436.jos-25-5905

Purpose To report a rare case of Mooren’s ulcer in a healthy young male without systemic autoimmune disease, and to highlight the effectiveness of conjunctival resection as therapy for cases unresponsive to medical management. Case report A 34-year-old immunocompetent male presented with progressive peripheral corneal ulceration in the left eye. Extensive systemic and infectious evaluations, including rheumatologic, immunologic, and microbiological testing, were unremarkable. Human leukocyte antigen genotyping was DR17(03)-negative and DQ2-positive. Rheumatological evaluation yielded no definitive systemic diagnosis. Despite immunosuppressive therapy with adjuvant medications, the epithelial defect and stromal inflammation persisted. The patient underwent conjunctival resection, resulting in marked reduction in inflammation, rapid re-epithelialization, and structural stabilization of the cornea. Histopathology of excised conjunctiva showed nonspecific inflammation without granulomatous changes, vasculitis, or neoplastic features. During follow-up, patient remained in remission with visual acuity preserved at 6/6 bilaterally and no recurrence. Conclusion Mooren’s ulcer is rare but vision-threatening. Early recognition, comprehensive evaluation, and timely surgical intervention can be vision-saving. This case highlights the role of a multidisciplinary approach and supports conjunctival resection as a useful adjunct in refractory disease. Long-term follow-up is essential.

Maxillary Sinus Lift Using the Lateral Window Technique with Hydroxyapatite and Beta-Tricalcium Phosphate (β-TCP) Graft

Dec 2025 DOI 10.14302/issn.2473-1005.jdoi-25-5870

This narrative literature review investigates the clinical feasibility of maxillary sinus lift using the lateral window (or traumatic) technique, employing a grafting material composed of hydroxyapatite associated with beta-tricalcium phosphate. The study is based on the premise that bone resorption and sinus pneumatization—common in edentulous posterior maxillae—pose a challenge to achieving primary stability during dental implant placement. Given the limitation imposed by reduced residual bone height, bone-grafting surgical techniques become necessary to enable implant-supported rehabilitation. The objective of this work is to analyze, through a literature review, the efficacy of combining synthetic biomaterials as an alternative to autogenous bone grafts, which are considered the gold standard in implant dentistry. A bibliographic search was conducted in the PubMed and LILACS databases and through the VHL portal, prioritizing articles addressing the biological properties of alloplastic grafts, the indications of the lateral window technique, and the clinical success rates of implants placed in previously grafted areas using such materials. The findings demonstrated that hydroxyapatite associated with beta-tricalcium phosphate exhibits favorable osteoconductive characteristics, such as adequate porosity and gradual resorption, while allowing the formation of viable bone within a clinically acceptable timeframe. The combination of these materials eliminates the need for a second surgical site, reduces morbidity, and maintains treatment predictability. It is concluded that the lateral window technique associated with synthetic biomaterials is a safe and effective alternative for patients with maxillary bone atrophy, capable of promoting suitable bone beds for dental implant placement and stabilization, with lower surgical risk and satisfactory clinical outcomes.

Enzymes Open Access

Disruption of Hydrogen Bonding Network Decreases Catalytic Diversity of Chloroperoxidase via Abolishing Both Chlorination and Dismutation Activities

Nov 2024 DOI 10.14302/issn.2690-4829.jen-24-5291

The perpendicular orientation of the proximal alpha helix to the heme plane in chloroperoxidase (CPO) maximizes the influence of its intrinsic helix dipole that has been shown to reduce the “push-effect”, thereby increasing the heme redox potential and fine-tuning the catalytic capabilities of CPO. We investigated the effects of a disruption of the hydrogen bonding network between R26-N37 and A27-N33, formed by the proximal alpha helix, on the CPO structural stability and catalytic profile using site-directed mutagenesis and spectroscopy. The mutant CPO (R26A, N33A, and R26A/N33A) exhibited significant tertiary structural changes and distinct heme coordination, likely, due to destabilization of the proximal helix as a result of the disruption of the proximal hydrogen bonding network. In line with these observations, biochemical characterizations showed that all mutants displayed dramatically different activity profiles relative to that of the WT CPO. Mutant epoxidation and peroxidation activities were markedly enhanced, especially in the R26A/N33A CPO mutant. Moreover, all mutant CPO enzymes exhibited broader pH profiles in both epoxidation and peroxidation activities, including a shift in the optimal peroxidation activity towards pH 3.5 as opposed to pH 2.75. Conversely, the dismutation activity (pH 3.0-5.5) was almost completely lost while chlorination activity (pH 2.75-5.0) was virtually non-existent in all CPO mutants. Our results demonstrate the important role the R26-N37 and A27-N33 hydrogen bond pairs play in the heme coordination and tertiary structure of CPO defining its catalytic capabilities, and also suggest the importance of the proximal helix stability and orientation.

Big Data Research Open Access

Risk Management and Organizational Resilience: Analysis of the Italian Scenario During Covid-19 Pandemic, with A Look at the Challenges of Technology and Sustainability

Oct 2020 DOI 10.14302/issn.2768-0207.jbr-20-3568

The Coronavirus emergency represents an epochal challenge for all world health organizations. In these times of profound destabilization of healthcare organizations, become urgent some thoughts on how to deal with the organization and re-engineering process as well as on concepts, relatively new, such as "resilience" and "business continuity". The company management need having to predict, design and plan a profound process of change in their Clinical and Corporate Governance. With the implementation of phases 2 and 3 of management of the pandemic and the coexistence of doctors and citizens with the new Coronavirus, it has become a priority to develop territorial models of assistance to established or suspected Covid patients, starting with the creation of monitoring networks based on the model of the “sentinel” general practitioner. One of the main concerns of Healthcare, since the beginning of the Covid-19 emergency has been to get closer to the citizen-patient. It is therefore necessary to find stimuli to restart with new methods of care, new health and social-health services, moving the current care paradigm for Covid-19 from the hospital to the territory, optimizing the constituent elements of the districts, primary care and general practice in a multidisciplinary approach.

Insights on the Thermal and Physical Stability of the Modified Polymerizable Liposomes for Improved Photoactivity

Sep 2020 DOI 10.14302/issn.2835-513X.ijl-20-3454

We investigated physical steric and thermal stability effects induced by cholesterol and polyethylene glycol (PEG) in liposomes encapsulated with riboflavin. The composition of liposome was varied systematically to decipher the individual and combined effects of cholesterol and PEG on the stabilization of liposomes, specially the photopolymerizable liposomes for their potential applications in photo-treatments. Our results indicate that inclusion of PEG in the lipids enhances the steric stabilization by adopting a brush-like regime that prevents the agglomeration of encapsulated liposomes. A mechanistic differential scanning calorimetry studies reveal the phase transitions and enthalpy changes in the lipid bilayer due to the presence of cholesterol suggesting its role in regulating membrane fluidity. Supporting in- vitro studies confirm the efficacy of PEGylated formulations encapsulating riboflavin.

Molecular Spectroscopy and Molecular Docking Studies on (E)-1-(4-Bromobenzylidene) Thiourea

Feb 2018 DOI 10.14302/issn.2377-2549.jndc-18-1933

The organic molecule (E)-1-(4-bromobenzylidene)thiourea (BBTU) have been synthesized and characterized using FT-IR and FT-Raman spectral studies. The quantum chemical calculations of BBTU have been studied using DFT/B3LYP/6-31G(d,p) level of theory. The stable conformer is identified by the potential energy surface scan. The complete vibrational assignments were performed on the basis of PED analysis with the help of SQM method. NBO analysis was carried out to explore the various conjucative/hyperconjucative interactions within the molecule and their second order stabilization energy. The NLO activity of BBTU is calculated and compared with the standard Urea molecule. The energies of the FMOs are used for the determination of global reactivity descriptors. The electrophilic and nucleophilic charge sites were identified by the molecular electrostatic potential mapped surface. The molecular docking of BBTU is carried out with the receptors of 3U2D and 1JIJ to screen the bacterial activity.

Dimerization of the BASIC PENTACYSTEINE Domain in Plant GAGA-Factors is Mediated by Disulfide Bonds and Required for DNA-Binding.

Aug 2017 DOI 10.14302/issn.2638-4469.japb-17-1563

GAGA-binding proteins in plants are encoded by the BARLEY B-RECOMBINANT / BASIC PENTACYSTEINE (BBR/BPC) family, which can be spilt into several groups on the basis of sequence divergence. The proteins of the different groups share an evolutionary conserved BASIC PENTACYSTEINE (BPC) domain at their very C-terminus that is important for DNA binding. Hallmark of this domain are five Cysteines at defined positions and spacing, which are considered to form a zinc-finger like structure that is involved in GAGA-motif recognition. Here, we report the formation of stabile homodimers between Arabidopsis thaliana group I member BPC1 or between group II member BPC6 in SDS-PAGE. Serial mutations of the highly conserved five Cysteines in the BPC domain of Arabidopsis thaliana BPC1 were tested for their capacity to bind to GAGA-motifs by DPI-ELISA. Our results do not support the idea of a direct involvement of these residues in making physical contact with the DNA, e.g. by formation of a zinc-finger structure. Instead, the data implies an indispensable function for the five Cysteines in homodimerization and stabilization of the protein structure by disulfide bonds. Accordingly, protein folding and structure prediction suggests the formation of a scaffold for dimerization that is supported by three intermolecular and one intramolecular S-S bond. The high degree of conservation between the BPC domains from the different groups and from different species denotes that this role for the five Cysteines might be evolutionary retained.

AB Initio (DFT) and Vibrational Studies of the Synthesized Heterocyclic Compound 2-6-oxo-2-Thioxotetrahydropyrimidin-41H-Ylidene Hydrazine Carbothioamide

Aug 2017 DOI 10.14302/issn.2377-2549.jndc-17-1645

The structure of the newly synthesized hydrazone derivative 2 - 6 – oxo - 2-thioxotetrahydropyrimidin – 4 1H - ylidene hydrazine carbothioamide (OTTHPYHCT)compound is determined by using spectral information and elemental study. Density functional theory (DFT) studies were performed using the B3LYP/6-31G (d, p) basis set to expand imminent into their structural properties. Frontier molecular orbital (FMO’s) analysis of title compoundwas computed at the same level of theory to get knowledge about their kinetic stability of the molecule by the energy gap value obtained. Global reactivity descriptors are determined to explain the biological activity of the molecule. NBO analysis provides information about charge transfer, delocalization effect, hyperconjugative interactions and the energy responsible for the stabilization of the compound. First hyperpolarizability analysis nonlinear optical response was simulated at the B3LYP/6-31G d, p level of theory as well. Thermodynamic parameters explain vibrational intensity of the molecule.

Skeletal Muscle Calcium Channel Mutation R528G: Enhanced Channel Inactivation and Omega-Current at Hyperpolarization Contribute to Hypokalemic Periodic Paralysis.

Jun 2016 DOI 10.14302/issn.2470-5020.jnrt-16-993

Autosomal dominant inherited hypokalemic periodic paralysis (HypoPP) is caused by S4 voltage sensor mutations in skeletal muscle CaV1.1 calcium or NaV1.4 sodium channels. In the present study, a small German family with the known CaV1.1-R528G is described. The phenotype consists of short and infrequent episodes of limb weakness with ictal respiratory and cardiac involvement. There is incomplete penetrance in women, and acetazolamide is beneficial in two patients also taking daily potassium. Expression of the mutation in the GLT mouse muscle cell line revealed accelerated kinetics of inactivation by twofold, a left-shift of the steady-state inactivation curve by 13mV and a reduced recovery from fast inactivation by up to 39%. These changes suggest a stabilization of the inactivated state. Additional significant slowing of activation may support a second open state with differing ion selectivity or decreased activation of calcium-activated potassium channels and thereby contribute to weakness similar to other CaV1.1 mutations. Also, as documented for other HypoPP mutants, we found a hyperpolarization-induced inward guanidinium current of 22nS/nF which can be interpreted as an omega current along the voltage sensor gating pore that leads to a gain- of- function at potentials near the resting membrane potential. This finding can explain the long-lasting depolarizations that are known to lead to paralysis. The omega current is large enough so that a relatively mild hypokalemic trigger of 2.4mM already produces episodes of weakness in vivo.

Ophthalmic Science Open Access

Idiopathic Macular Telangiectasia Associated with Large Soft Drusen and Retinal Angiomatous Proliferation

Apr 2016 DOI 10.14302/issn.2470-0436.jos-15-710

Idiopathic macular telangiectasia type 2 is a rare retinal condition usually characterized by parafoveal telangiectatic vessels, hyperplastic pigment plaques and seldom a full thickness macular hole or a retinal neovascularisation. Herein we describe an atypical presentation of this disease. Methods Review of the patient’s clinical and angiographic records. Results A 87-year-old white man was diagnosed with idiopathic macular telangectasia type 2. Ophthalmological and angiographic examination disclosed telangiectasia of the parafoveal capillaries together with extensive bilateral granular soft drusen and unilateral retinal angiomatous proliferation (RAP). Initially photodynamic therapy with verteporfin (PDT) and subsequently intravitreal injections of bevacizumab were used to treat RAP lesion. This approach provided visual acuity stabilization up to 24 months. Conclusion This case of ours shows that drusen may be a feature of macular teleangiectasia type 2. It also emphasizes that PDT and anti-VEGF therapy are both safe and effective for treating neovascular complications of this disease.

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