Electrochemical behaviour of prussian blue deposits in presence of some non-aqueous background solutions

'J;he redox surface film of Prussian Blue (PR) is studied for its electrochemical properties in contact with I non-aqueous solutions in acetonitrile (ACN), dimethyl formamide (DMF) and dimethyl sulphoxide i (DMSO). The Cyclic VoItammetric (CV) results are quite interesting as they tend to be irreversible in contrast to the behaviour in aqueous medium. Surface coverage from CV data showed an increase in the order of H20> ACN > DMF > DMSO. A similar trend is reflected in the facile intercalationldeintercalation proceSSl::S of hydrated and solvated potassium ion computed from double potentia) step chronoamperometric studies. Diffusion coefficients and heterogeneous electron transfer rate constants are elucidated by processing I-t transients

Enhancement of dissolution rate of Olmesartan medoxomil using urea as carrier by different solid dispersion techniques

The poor solubility of drug substances in water and their low dissolution rate in aqueous G.I.T fluid often leads to insufficient bioavailability. As per Biopharmaceutical Classification System (BCS), Olmesartan belongs to the class-II category having poor solubility and high permeability. Since only dissolved drug can pass the gastrointestinal membrane, the proper solubility of the drug is ultimately desired. Its oral bioavailability is 26%. Hence, an attempt was made to enhance its solubility by formulating solid dispersions using different techniques viz., Melting, Kneading, Co-precipitation, Solvent evaporation and Physical mixing etc., Drug and carrier (Urea) in different ratios like 1: 1, 1: 2, 1: 3 and 1:4 were used for formulating solid dispersions. The compatibility of the drug with the carrier was checked by FTIR studies, these results revealed that there was no interaction between them. The angle of repose, bulk density, tapped density; Carr’s index and Hausner ratio were calculated for the micrometric characterization of all the solid dispersions. The drug content was found to be high and uniform in all formulations. The prepared Solid dispersion SEM4 (1:4) showed minimal wetting time of 13 seconds compared with the other formulations. In vitro dissolution, release studies in Phosphate buffer pH of 6.8 revealed that the prepared solid dispersions showed faster drug release compared with the pure drug.  The in vitro dissolution profile showed ascendency on increasing the carrier concentratio

Hydrothermal synthesis of reduced graphene oxide-CoFe2O4 heteroarchitecture for high visible light photocatalytic activity: Exploration of efficiency, stability and mechanistic pathways

RGO-CoFe2O4 heterostructure nanocomposite was prepared by hydrothermal method and was characterized by various analytical techniques such as Powder X-ray Diffraction method (PXRD), UV-vis absorbance, Photoluminescence (PL), Fourier Transform Infra Red (FTIR) spectroscopic techniques, BET surface area measurements, Field Emission Scanning Electron Microscopy (FESEM), Raman Spectroscopy and Vibrating Sample Magnetometer (VSM). The results confirmed the formation of hybrid structure with CoFe2O4 particles embedded in RGO sheets. Photocatalytic activity of the nanocomposites was probed for the degradation of 4-Chlorophenol (4-CP) as the model compound under the visible light illumination. The photocatalytic activity decreases in the following order RGO-CoFe2O4 > CoFe2O4 > RGO. Further the activity of RGO-CoFe2O4 composite was explored in the presence of peroxymonosulfate (PMS) as an oxidant. LUMO of PMS can accommodate photogenerated electrons, thereby suppresses the recombination process. The enhanced activity of RGO-CoFe2O4 hybrid is compared to its individual counterparts and the higher activity is accounted to its unique electronic structure. RGO serves as electron acceptor from CoFe2O4 and electron donor to the oxygen molecule. During the photocatalysis, transformation of the native structure from normal spinel to inverse spinel and vice versa may take place continuously from the process of electron trapping and detrapping by Fe3+ and Co2+ions. The observed continuous absorption for RGO-CoFe2O4 composite in the UV-vis spectra implies active d-d transitions involving transition metals present in the nanocomposite. © 2017 Elsevier Ltd. All rights reserved

Heterogeneous advanced photo- Fenton process using peroxymonosulfate and peroxydisulfate in presence of zero valent metallic iron: A comparative study with hydrogen peroxide photo-Fenton process

The present research work has demonstrated the use of zero valent metallic iron (Fe0) in the photo-Fenton process under the UV illumination as a promising and novel technique. Oxidants like oxone a peroxymonosulfate (PMS) and ammonium persulfate a peroxydisulfate (PDS) were used in comparison with classical hydrogen peroxide (HP). PMS was found to be a better oxidant in comparison with HP and PDS at higher pH conditions especially in the pH range of 5–7. PMS acts as better oxidant with dipolar unsymmetrical structure, higher oxidation potential and its lower LUMO energy can easily accept electrons more readily compared to the other two oxidants. The degradation rate for various oxidation processes at pH 3 shows the following decreasing order: Fe0/PMS/UV ≈ Fe0/HP/UV > Fe0/PDS/UV > HP/UV > PDS/UV> PMS/UV > Fe0/PMS/dark > Fe0/HP/dark > Fe0/PDS/dark > Fe0/UV > Fe0/dark. At pH 5, PMS/UV and PDS/UV systems show similar efficiencies as Fe0/PMS/UV and Fe0/PDS/UV process, since most of the Fe0 surface is covered by the precipitates of hydroxide and oxyhydroxides. Though recycling capability of iron powder is almost comparable for first to fifth repetitions, Fe0 retains its recycling capability better in the presence of HP for the further runs rather than PDS and PMS

A Descriptive study on ectopic pregnancy in a tertiary care centre

JUSTIFICATION: Ectopic pregnancy is an emergency situation in which timely intervention will reduce the maternal mortality & morbidity. Clinical presentation varies from case to case and still there is a chance of missing diagnosis in a small proportion of patients even with availability of advanced imaging techniques. For early diagnosis a clinician should well aware about the various presentations of ectopic pregnancy. My study will provide a detailed clinical description on ectopic pregnancy. AIM OF THE STUDY: A detailed study on ectopic pregnancy over a particular time period in order to determine the incidence, risk factors, clinical features, diagnostic methods, treatments, morbidity and mortality associated with ectopic pregnancy in a tertiary care hospital and analysis of various aspects of ectopic pregnancy with a view to suggest interventions to join the global trend of early diagnosis and conservative management. MATERIALS AND METHODS: The study was a cross-sectional study. The study consists of ‘n’ no of ectopic pregnancy cases attended Tirunelveli Medical College Hospital Obstetrics and Gynaecology department for a period of two years from July 2012 to June 2014. Inclusion criteria: All cases of ectopic pregnancy / suspected ectopic pregnancy by clinical or sonological method. Exclusion criteria: The study involved all cases of ectopic pregnancy. There was no exclusion criteria. METHODS AND MATERIALS: Data collection tool was used to collect the different information. Face to face interviews were conducted using data collection tool by the investigator including detailed history taking and relevant physical examination. All data were collected on a structural data form (sample enclosed) and analysed for descriptive statistics. Information regarding patient profile, risk factors, sterilisation status, use of other contraceptive methods, presenting symptoms and signs, physical examination, ultrasound findings, types of treatment, per operative findings, no of transfusions, post operative morbidity and length of hospital stay were analysed. Post operatively HPE reports were collected from the pathology department and final diagnosis was made. RESULTS: A total of 138 patients were recruited in the study. 5 patients in the study had undergone medical management. Remaining 133 patients had undergone laparotomy. During laparotomy 124 patients were found to be having ectopic pregnancy which was confirmed by histopathology. One patient had heterotopic pregnancy. One patient had negative laparotomy. Remaining 7 patients had other gynaecological lesions. Majority of the patients (63.8%) were in the age group of 21 to 30 years and multigravida (75.4%) were found to be more prone to have an ectopic pregnancy. Majority (54.3%) of the patients presented with 5 to 8 weeks of amenorrhoea. Among the nulliparous women 62.5% had history of subfertility for more than one year. The commonest risk factors among the study population were previous LSCS, tubal surgeries, previous ectopic pregnancies, prior H/O abortions, H/O infertility and pelvic inflammatory disease. The most common presenting symptom was abdominal pain which was found in 94.9% of patients, followed by amenorrhoea in 72.5% of the patients. The classic triad was present only in 31.9% of cases. The most common examination findings were tachycardia (51.4%) and hypotension (12.3%). 48.6% of patients were severely anaemic with Hb less than 5 gms%. In per abdominal examination abdominal tenderness (56.5%) was the most common finding. In per vaginal examination forniceal tenderness (57.2%) was the most common finding. Cervical excitation test was positive in 72.5%. In p/v the presence of adnexal mass has highest specificity and positive predictive value. (100%) UPT has highest (98.4%) sensitivity, but the specificity was low. In ultrasound examination empty uterus, adnexal mass and free fluid were strongly suggestive of ectopic pregnancy, especially in the presence of positive UPT. Treatment delay for more than 2 hrs was present in 36 (26%) patients. The most common reason for time delay was late diagnosis of ectopic pregnancy. In surgically managed group all 132 patients underwent laparotomy. Total/partial salphingectomy and salphingo oophorectomy were the common surgeries performed. During laparotomy 109 (79%) cases were found to be ruptured including one chronic rupture. Ampulla was the most common site of the ectopic found in 43.5% of the patients. Only one patient had hysterectomy for uncontrolled bleeding from the ruptured site of cornual ectopic pregnancy. No maternal mortality was found during the study period. CONCLUSIONS: 1. Ectopic pregnancy is famous for its diversity of clinical presentations and atypical presentations. Strong suspicion is required for its early diagnosis. 2. Amenorrhoea is not necessary for the diagnosis of ectopic pregnancy. UPT and ultrasound should be advised to all reproductive age group patients presenting with abdominal pain, bleeding p/v with or without amenorrhoea. 3. Sterilisation could not rule out the possibility of an ectopic pregnancy. So, we should advise the patients to come for check up if she misses the periods as early as possible. 4. The recommended sterilisation techniques should be followed strictly. 5. To join the global trend of conservative management for ectopic pregnancy, early diagnosis before rupture is important. 6. Ultrasound is the simple and gold standard diagnostic method for ectopic pregnancy in low resource settings. 7. Routine first trimester ultrasound should be done in all pregnant women at the booking visit itself. 8. UPT kits and sonographic equipments should be made available in all primary health centres and emergency gynaecological units. 9. Staffs should be trained adequately to use and interpret the sonographic images. 10. Early diagnosis and referral is the key factor in reducing the maternal morbidity and in preserving the future fertility. 11. Because of the high incidence of tubal rupture in our set up, community education is required to inform the women to attend the health facilities as early as possible once they have symptoms

Comparative evaluation of classical subarachnoid block, unilateral subarachnoid block and low dose subarachnoid block in high risk patients undergoing lower limb surgeries

INTRODUCTION: It was in the year 1899 August Bier, used subarachnoid block and he gave first deliberate spinal anaethesia. Spinal anesthesia continued to be most common anesthetic technique because of its rapid onset, safety and simplicity. Even this relatively safe technique can have complication such as hypotension which a normal patient can tolerate but can be detrimental to patients with haemodynamic instability. The safety improves if the block can be localized to the area of surgery. A special technique of spinal anaesthesia named spinal hemi block was described for one limb surgeries, which was named as spinal hemi analgesia. This is also known as unilateral spinal anaesthesia. The distance between the left and right spinal roots is only 10-15 millimeter in the lumbar or lower thoracic level. Such a small distance should reasonably prevent from producing strictly unilateral block of the spinal nerve roots. However, various clinical reports suggested that using small doses of either hypo or hyperbaric anesthetic solution injected at low speeds through directional needles in patients lying in the lateral decubitus position for 10-15 minutes results in preferential distribution of spinal anaesthesia towards the operated side, providing intense surgical block on that side. Even though the term unilateral spinal anaesthesia has been in vogue for a long time most of the research on this are recent. Even though performing spinal anaesthesia is technically easier, the complications which are usually expected like hypotension and bradycardia can be detrimental to this high risk group patients. AIM: To compare the efficacy of classical subarachnoid block using, 0.5% bupivacaine,unilateral spinal anesthesia using 0.5% bupivacaine and low dose spinal anesthesia using 0.5% bupivacaine 1.5 ml with 0.5 ml of fentanyl (25 micro grams) in high risk patients undergoing emergency unilateral lower limb surgeries based on the following parameters. 1. Feasibility of maintaining unilaterality of Subarachnoid block. 2. Haemodynamic stability in the peri-operative period. 3. Onset, Quality and duration of block. MATERIALS AND METHODS: The effect of lateral position on maintaining unilaterality of spinal anaesthesia and the effect of adding fentanyl to hyperbaric bupivacaine in achieving unilateral spinal anaethesia undergoing emergency lower limb surgeries on one limb was studied in 60 patients. The study was approved by the institutional research and ethics committee. The total number of patients are 60.They were divided into three groups. Control Group - Received 2ml of 0.5% Bupivacaine and turned to Supine position immediately. STUDY Group I - Received 1.5 ml of 0.5 % Bupivacaine with 25 μg( 0.5 ml) Fentanyl and kept in lateral decubitus position for 10 mints and then turned supine. STUDY Group II - Received 2ml of 0.5 % Bupivacaine and kept in lateral decubitus position for 10 mints and then turned supine. Inclusion Criteria: 1. Patients between 18 to 80 years of age. 2. Patients belonging to ASA physical status III and IV. 3. Undergoing emergency unilateral lower limb surgery. Exclusion Criteria: 1. All Contra indication for central neuraxial block. 2. Patients who are not co-operative to positioning for subarachnoid block. 3. Patients with anomalies of the spinal column SUMMARY: This prospective randomized study was done to compare the efficacy of classical subarachnoid block using 0.5% bupivacaine, unilateral spinal anesthesia using 0.5% bupivacaine and low dose spinal anesthesia using 0.5% bupivacaine 1.5 ml with 0.5 ml of fentanyl (25 micro grams) in sixty high risk patients undergoing emergency unilateral lower limb surgeries. This study yielded the following results: 1. Unilateral spinal anaesthesia can be produced by using small volume of hyperbaric local anaesthetic, slow injection of drugs and maintaining the patient in lateral position with the operated limb being dependant. 2. Unilateral spinal anaesthesia produces higher level of sensory block on dependant limb when compared to non-dependant limb. 3. Unilateral spinal anaesthesia produces higher level and greater degree of motor block on dependant when compared to non-dependant limb. 4. Unilateral spinal anaesthesia is more haemodynamically stable in high risk sick patients when compared to classical subarachnoid block. 5. Classical Subarachnoid block produces more haemodynamic complications (hypotension and bradycardia) which requires treatment. 6. Low dose Bupivacaine with Fentanyl subarachnoid block may lead to alteration in baricity / specific gravity of the solution. This however does not decrease the differential blockade between the two limbs. 7. The low dose Bupivacaine with Fentanyl Subarachnoid block is a more haemodynamically stable option in high risk patients. 8. The onset time and time for two space regression is not different among the three groups. 9. The biggest limitation to the production of unilateral subarachnoid block is the inability of the patients to lie in the lateral position for 10 minutes. 10.Time consideration for production of unilateral Subarachnoid block may be a restraining factor in emergency surgeries. The patient should be maintained strictly in lateral position with the limb to be operated kept dependant for at least 15 minutes to achieve unilateral block. CONCLUSION: From this study we can conclude that in high risk patients undergoing emergency unilateral lower limb surgeries. 1. Unilateral low dose Subarachnoid block offers better haemodynamic stability during the intra-operative period. 2. The onset, quality and duration of block matches those produced by classical subarachnoid block. 3. It is possible to produce unilateral subarachnoid block by maintaining patients in lateral position for 10 minutes

Characterisation and antimicrobial susceptibility pattern of non fermenting gram negative bacilli and molecular analysis of acinetobacter spp., from various clinical samples in a Tertiary care hospital.

Non fermenting Gram Negative Bacilli (NFGNB) once considered as contaminants have now emerged as a major cause of life threatening nosocomial infections and as multidrug resistant pathogens Pseudomonas aeruginosa and Acinetobacter baumannii were the most common NFGNB isolated in this study. Difference in antimicrobial susceptibility by nonfermenters pose a great problem in treating these infections. ESBL and MBL production by these organisms lead to high morbidity and mortality and left with the only option of treating them by potentially toxic drugs like Colistin and Polymyxin B

Green synthesis of silver nanoparticles using Datura stramonium leaf extract and assessment of their antibacterial activity

Silver nanoparticles of 15-20 nm size with spherical shape were synthesized from green synthesis method using Datura stramonium leaf extract. Synthesized Ag NPs were studied for their optical, structural, surface morphological and antibacterial properties. The optical study shows that the appearance of SPR peak at 444 nm in the absorption spectrum is affirming the formation of Ag NPs and its high intensity with narrowed width indicating the homogenous size and shape of the Ag NPs. Structural studies reveal the good crystalline nature of face center cubic structure of Ag crystal and preferentially oriented along (111) plane with average crystallite size of 18 nm. FTIR analysis exhibits the possible reducing biomolecules within the leaf extract. The well defined homogenous spherical shape of the Ag NPs is clearly observed from the TEM studies and lattice fringes spacing of 0.23 nm shows the high crystalline nature of the synthesized Ag NPs. EDAX profile affirms the Ag crystal by the presence of energy peak at 3 eV. The synthesized Ag NPs showed antibacterial activity against E. coli and S. aureus bacteria. However, well pronounced activity was observed against E. coli