TOWARDS THE UNDERSTANDING OF THE EFFECT OF FUNCTIONAL MONOMERS ON LATEX PARTICLE MORPHOLOGY FORMED BY EMULSION POLYMERIZATION

Emulsion polymerization is a multiphase reaction process and the overall kinetics depend on the reaction rates in both the aqueous and particle phases. The morphology development within composite latex particles is controlled by both kinetic and thermodynamic factors. Functional monomers like acrylic acid and 2-hydroxyethyl methacrylate are widely used in emulsion polymerization at low concentrations (usually \u3c 10% to total monomers) to improve various properties like shear and freeze thaw stability of the latex, adhesion of the polymer to metal and paper, and to create the possibility for post-polymerization chemical modifications. These monomers are highly water soluble and very much more polar than the commonly used acrylate and styrene monomers. This dissertation deals with the effect of such functional monomers on the reaction kinetics during the emulsion polymerization and on the resulting morphology of the composite latex particles. A detailed examination of the distribution behavior of vinyl acid and hydroxy (meth)acrylate functional monomers between the nonfunctional monomer phase and the aqueous phase is reported here. Due to the dimerization and multimer formation capabilities of vinyl acid and hydroxy (meth)acrylate monomer via hydrogen bonding, the distribution of these monomers between aqueous and organic phases can be highly concentration dependent. In addition, the distribution of vinyl acids is a strong function of pH. Common emulsion polymerization with functional monomers uses more than one nonfunctional monomer. We found that the distribution of functional monomers can be effectively predicted for multicomponent nonfunctional monomer mixtures using appropriate `mixing rules\u27. The distribution of a monomer between the aqueous phase and the polymer particle phase is normally estimated using monomer-polymer Flory-Huggins interaction parameters and we have carefully determined such parameters for the functional monomers and various polymers examined in this work. From the experimental and simulation studies for seeded emulsion copolymerizations with functional monomers, we found that both the aqueous phase and the particle phase kinetics are affected by these monomers. The functional monomers produced longer oligoradicals (Z-mers) in the water phase which then entered the particles to promote polymerization. Moreover, the distribution studies revealed an increase in the water phase monomer concentrations when these functional monomers were present. Both of these phenomena combined to result in an increase in the radical entry rate into the particles as compared to reactions without functional monomers under similar conditions. The particle morphologies obtained from seeded emulsion polymerizations with functional monomers were characterized and compared to those without the functional monomers. In these studies the levels of the functional monomers were varied between 0% and 10% and the polarity differences between the seed and second stage polymers changed in different directions depending on the particular system. For all of the systems studied, it was found that for the cases where the final particle morphology was either at or close to equilibrium (in terms of the minimization of free energy), the incorporation of the functional monomers did not impact the morphology significantly. However for the cases where the final morphologies were kinetically controlled, increases in the amount of functional monomer in a nonpolar second stage monomer increased the amount of phase mixing with a polar seed polymer

Attenuated Antioxidant property of UV-B Irradiated Piperine in Ischemia-Reperfusion Injury in SD rat

PIP is well known antioxidant that showed neuroprotection against cerebral ischemia (2h) /reperfusion (24h) (I/R) injury. However, it can degrade very easily in presence of UV-R/sunlight. Here, comparative study of non-irradiated and UV-B (0.6mW/cm2) irradiated PIP was performed against cerebral I/R injury. First, the dose dependence evaluation of neuroscore was investigated after the non-irradiated PIP intravenously (2.5, 5, 10 mg/kg b w, i.v.) treatment. The neuroprotective outcome of UV-B irradiated and non-irradiated PIP (5 mg/kg b w, i.v.) against cerebral I/R in SD rats was investigated through evaluation of neuroscore and quantification of infarct volume by TTC staining. The result of photodegradation of PIP under UV-B irradiation revealed the formation of photoproducts. There were no changes in Cortical and mitochondrial ROS level and antioxidant defence enzyme (CuZn-SOD, Mn-SOD, and catalase) and non-enzyme (LPO, protein carbonyl and reduced glutathione) activities in UV-B irradiated compare vehicle group. Thus, our results demonstrated that PIP could lose its parent structure in presence of UV-B and attenuates its neuroprotective efficacy. Thus, UV-B exposure must be avoided during dietary intake of PIP to obtain best neuroprotective response

EFFECT OF PREVIOUS SCORPION BITE ON THE EFFICACY OF INTRATHECALLY ADMINISTERED LEVOBUPIVACAINE IN SUBARACHNOID BLOCK

Objectives: Local anesthetics administered by spinal anesthesia acts through sodium channels. Mutations of sodium channels may be responsible for resistance to local anesthetic agents. The scorpion venom contains neurotoxins that block the sodium channels. In view of the high prevalence of scorpion stings in our region and observation of failure of spinal anesthesia in patients with a history of scorpion stings in routine practice, the present study is planned. Methods: Forty patients of the American Society of Anesthesiologists Grade I or II who were undergoing infraumbilical surgery were divided into two groups as S (patients with h/o scorpion bite) and C (patients with no such history). The subarachnoid block was given with 3.2 ml of injection Levobupivacaine 0.5% heavy using 26 gauzes Quincke spinal needle. A blind observer recorded a sensory block using a needle prick and a motor block using the Bromage scale. Onset of sensory and motorized block, time to peak of sensory, and motor block and its relation to number of scorpion bites were observed in both the groups. Results: The onset of sensory (2.61±1.68 mins) and motor blockade (2.91±1.80 mins) was significantly delayed in Group S (p=0.010 and 0.004, respectively). Time to peak of sensory and motor blockade was also prolonged in Group S (6.45±2.83 mins and 7.8±3.95 mins) compared to Group C (3.60±0.84 mins and 4.56±1.30 mins) which was statistically significant (p<0.05). Patients who had previous scorpion bites (Group S) had a significant failure rate of spinal anesthesia compared to the control group. Conclusion: In this study, it was observed that the patients with scorpion bites had a significant failure rate of spinal anesthesia, suggesting probable resistance to the local anesthetic agents

ESTIMATION OF TOTAL PHENOLIC AND FLAVONOID CONTENT OF POLYHERBAL FORMULATION DASHANG LEPA

Background: Indian system of medicine mainly based on polyherbal compound to treat various types of diseases. Dashang lepa is one of the prestigious formulation of ten indigenous drugs which are having predominantly anti-inflammatory properties and clinically used in inflammatory swelling like boil, furunculosis, cellulitis, erysipelas etc. As several reports are on various individual phytochemical, phenolic and flavonoid content but none is having study of polyherbal compound Dashang lepa. Objectives: Total phenolic and total flavonoid content were studied of alcoholic extract of Dashang lepa. Method: Methanolic extraction was done by hot percolation method through soxhlet apparatus. Phenolic content was estimated using Follin ciocalteau reagent, flavonoid using aluminum chloride (2%) reagent as quercetin equivalent. Results: Estimation of total phenolic and total flavonoid content showed that Dashang lepa extract was having phenolic content (15.8±1.14) ug Gallic acid equivalents (GAE) and flavonoid content (22.4±2.54) in ug of quercetin equivalents (QE)

A STUDY ON MARKETING OF MUSHROOM IN HARDOI DISTRICT OF UTTAR PRADESH

India’s biodiversity coupled with its vast resources including competitive workforce, highly intelligent scientific and rich business community make our country the best choice for growing vegetable crops like mushroom for world market. The field of mushroom crops is assuming importance because of growing demand for mushroom throughout the world. India is not a major producer of any particular variety of the mushroom, but it does cultivate mushrooms and has great potential as an important producer in the future. From a production standpoint, the white button mushroom has the highest growth rate and potential for production. However, the cultivation of oyster mushrooms has been more common since the end of the last century, when the infrastructure of oyster mushroom was much improved, therefore capital requirements went down as compared to requirements for white button mushroom cultivation. View Article DOI: 10.47856/ijaast.2022.v09i04.00

Modified chitosan hydrogels as drug delivery and tissue engineering systems: present status and applications

AbstractChitosan, a natural cationic polysaccharide, is prepared industrially by the hydrolysis of the aminoacetyl groups of chitin, a naturally available marine polymer. Chitosan is a non-toxic, biocompatible and biodegradable polymer and has attracted considerable interest in a wide range of biomedical and pharmaceutical applications including drug delivery, cosmetics, and tissue engineering. The primary hydroxyl and amine groups located on the backbone of chitosan are responsible for the reactivity of the polymer and also act as sites for chemical modification. However, chitosan has certain limitations for use in controlled drug delivery and tissue engineering. These limitations can be overcome by chemical modification. Thus, modified chitosan hydrogels have gained importance in current research on drug delivery and tissue engineering systems. This paper reviews the general properties of chitosan, various methods of modification, and applications of modified chitosan hydrogels

Annexin A2 expression in prostate cancer cells

Background: Metastasis is a major cause of morbidity in prostate cancer patients, the primary mortality in this disease is metastasis to the bone tissue. Despite substantial efforts to understand prostate cancer metastasis, the mechanisms that are involved in preparing the metastatic niche for colonizing the prostate cancer cells are still not known. Therefore, there is an urgent need to identify essential regulators of bone metastasis in prostate cancer for therapeutic targets.Purpose: Annexin A2 (AnxA2), a calcium-dependent phospholipid binding protein, is overexpressed in the poorly differentiated high-grade adenocarcinomas of prostate cancer. AnxA2 exists as a monomer in the cytosol and as a heterotetrameric complex with S100A10 [(AnxA2)2-(S100A10)2] at the cell surface. Phosphorylation of AnxA2 at tyrosine 23 (pAnxA2-Y23) is an important event for the localization of AnxA2 to the cell surface. At the cell surface, AnxA2 heterotetramer complex provides binding site for tissue plasminogen activator (tPA) and converts plasminogen into plasmin, which plays an important role in invasion and metastasis of cancer. The cell surface AnxA2 also plays an important role in hematopoietic stem cell localization to the marrow niche and regulates osteogenic differentiation. However, the cell surface expression of AnxA2 in prostate cancer is unknown. Therefore, in the present study, we have demonstrated the cell surface expression of AnxA2 in prostate cancer cells to delineate the mechanism of bone metastasis.Methods: Prostate cancer cell lines, PC3 and DU145 were grown in RPMI-1640 medium containing 10% fetal bovine serum, in a humidified incubator at 37ºC with 5% CO2. The RWPE1, and PWR-1E cells were cultured in keratinocyte growth medium supplemented with 5 ng/ml human recombinant epidermal growth factor and 0.05 mg/ml bovine pituitary extract (Invitrogen, Carlsbad, CA) and maintained in an incubator under the conditions described above. Immunoblotting was used to detect the expression of pAnxA2-Y23 and AnxA2 proteins in cells.Results: Our results demonstrated that the expression of pAnxA2-Y23 is very high in prostate cancer cells (PC3 and DU145 cells) compared to normal prostate epithelial (PWR1E, and RWPE1 cells). However, the expression of total AnxA2 in both prostate normal and cancer cell lines is comparable. In addition, our membrane wash experiment showed that a large amount of AnxA2 is present at the cell surface of the PC3 and DU145 cell lines. In normal prostate epithelial cells, even though the expression of total AnxA2 is comparable to PC3 and DU145 prostate cancer cells, membrane localization of AnxA2 is very low.Conclusion: Our results clearly suggest that the cell surface expression of AnxA2 is high in prostate cancer cells due to increased phosphorylation of AnxA2 at tyrosine 23.Oklahoma Louis Stokes Alliance for Minority Participation ProgramMicrobiology, Immunology and GeneticsBiolog

COVID-19 Pandemic: Evidences from Clinical Studies

The public health crisis is started with emergence of new coronavirus on 11 February 2020 which triggered as coronavirus disease-2019 (COVID-19) pandemics. The causative agent in COVID-19 is made up of positively wrapped single-stranded RNA viruses ~ 30 kb in size. The epidemiology, clinical features, pathophysiology, and mode of transmission have been documented well in many studies, with additional clinical trials are running for several antiviral agents. The spreading potential of COVID-19 is faster than its two previous families, the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV). Apart from clinical manifestation, comorbid status is playing key role for prevalence of COVID-19 infection and mortalities. The comorbid effects associated with COVID-19 are diabetes, cardiovascular, digestive, hepatitis-B, cerebrovascular, hypertension, liver injury, coronary heart disease, cancer, rheumatoid arthritis, and neurological impairment. Antimalarial drugs (chloroquine and hydroxychloroquine), remdesivir, Tocilizumab, clopinavir/ritonavir, convalescent plasma therapy, spike protein-angiotensin-converting enzyme 2 (ACE2) inhibitors, human monoclonal antibodies, mRNA-1273, mesenchymal stem cells, Indian and Chinese traditional medicine, small molecules antioxidant, natural products and dietary supplements, high doses of vitamin-E, -C, -D, minerals, flavonoids,and IFN-beta are therapeutic intervention running to develop treatment against COVID-19. Although clinical usage of these therapeutic agents against COVID-19 is well documented, cytokine storms, absence of appropriate animal model have limited its therapeutic use. This review explores the clinical information currently available on COVID-19 on the mechanisms of infection, prevention, management, comorbid status, and current drug treatment options

Unusual Renal Tumors — Report of Four Cases

Collecting duct carcinoma, plasmocytoma and malignant fibrous histocytoma are rare but aggressive tumors of the kidneys. We present four cases we have recently encountered in our practice. In most of the cases imaging did not help in the pre-operative diagnosis. Surgery is the mainstay of treatment when recognized early. Clinician should be aware about these rare varieties of renal tumors whose prognoses may be worse than that of renal cell carcinoma. The Annals of African Surgery, Volume 6, 201

Determinants of Intravascular Resistance in Indian Diabetic Nephropathy Patients: A Hospital-Based Study

Aims and Objectives. Metabolic dysregulation has failed to explain clinical variability of patients with diabetic nephropathy and hence a renewed interest emerged in haemodynamic factors as determinant of progression and development of diabetic nephropathy. We therefore studied for various factors which can correlate with raised renal vascular resistance in diabetic nephropathy. Material and Methods. Renal vascular resistance was measured in patients with established and incipient diabetic nephropathy and compared with controls using noninvasive color Doppler examinations of intrarenal vasculature. Results. Renal vascular resistance correlated with age, duration of disease, GFR, serum creatinine, and stage of retinopathy. Renal vascular resistance was significantly reduced in patients on treatment with RAAS inhibitors and insulin, than those on OHA and antihypertensives other than RAAS inhibitors. Conclusion. The study implies that renal vascular resistance may help identify diabetics at high risk of developing nephropathy, and these set of patients could be candidates for RAAS inhibition and early insulin therapy even in patients without albuminuria