Enhanced photocatalytic activity of ZnO hexagonal tube/r-GO composite on degradation of organic aqueous pollutant and study of charge transport properties

ZnO hexagonal tube and ZnO/r-GO nanocomposites were synthesized by hydrothermal method and the nanostructures were characterized by XRD, UV-DRS, PL, FTIR, FESEM, and TEM techniques. The main violet emission peak of the synthesized nanostructures is due to the transition between interstitial zinc and hole (valence band) of ZnO. The potential of ZnO/r-GO nanocomposite was evaluated using methyl orange (MO) and rhodamine-B (RhB), and the results were compared with the activity of synthesized ZnO nanostructures. More than 95% of MO and RhB were by ZnO/r-GO nanocomposite and it was found to be higher than that of ZnO hexagonal tube. The degradation MO and RhB were found to follow first-order kinetics and it has a rate constant of 7.68 × 10^-2and 7.83 × 10^-2 min^-1, respectively. These results are mainly due to the enhanced charge transport property. Trapping experiments show that superoxide radical anion and hydroxide radicals are chief species responsible for the degradation of MO and RhB. The chemical stability of the nanocomposite was evaluated by cycle test experiments and it reveals that the catalyst can be reused up to few cycles without considerable loss of photocatalytic activity. This work affords a simple stratagem to integrate ZnO hexagonal tubes and r-GO nanosheets to construct effective catalysts for the degradation of organic compounds.

High power short duration (HPSD) versus lower power longer duration (LPLD) atrial fibrillation ablation: a multi-centre randomised controlled trial (HiLo-HEAT study)

Funding Acknowledgements

Type of funding sources: None.

Background

 Lower power (25W) longer duration (LPLD) radiofrequency (RF) ablation has conventionally been used on the posterior wall during pulmonary vein isolation (PVI) for atrial fibrillation (AF), to attenuate the risk of esophageal thermal injury (ETI). High power (40-50 W) short duration (HPSD) RF ablation results in shorter procedural times with no increase in ETI. However evidence had been limited by non-randomised studies.

Purpose

 To compare HPSD versus LPLD ablation and the effects on esophageal thermal injury (ETI) and procedural outcomes.

Methods

 In this multi-centre, prospective, randomised control trial, 88 patients with paroxysmal/persistent AF undergoing their first RF ablation procedure were randomised 1:1 to HPSD or LPLD ablation. Anterior wall ablation was done in both arms using 40-50 W, with ablation target of AI 500-500/ LSI 5-5.5. Posterior wall ablation was done using 40-50W (HPSD group) versus 25 W (LPLD group), with target AI 400/ LSI 4. Ablation involves wide antral circumferential PVI using contact force sensing ablation catheters, with additional ablation lines as per operator discretion. Circa multi-sensor esophageal temperature monitoring (ETM) probe was utilized. Endoscopy was performed within 24 hours to assess for ETI. The primary outcome was incidence of ETI, with secondary outcomes including acute procedural endpoints.

Results

 Mean age of the cohort was 61+/-9 years, with 31% females. 36 (41%) had PAF. PVI was achieved in 100% of patients, with posterior wall isolation (PWI) added in 19 PsAF patients (21.6%). There were more hypertensive patients in HPSD (p = 0.02). Significant esophageal luminal temperature rises (≥ 38 c) were seen in 93.2% of patients, with no difference between groups (p = 0.69). First pass isolation rates for left and right PVs were 85% and 61% respectively, with similar rates in both groups (p = 0.37, p = 0.65 respectively). HPSD group had shorter RF time (1613 vs 2303 secs, p <0.04), and fluoroscopy times (11.4 vs 13.1 mins, p = 0.05). Procedural times were lower in HPSD, although not significant (133.7 vs 150.8 mins, p = 0.10). Post ablation endoscopy showed 4 cases of ETI (4.5%), with equal occurrence in HPSD and LPLD (p = 1.0). All ETIs were class 2a (superficial ulcer), and treated with PPI therapy. Esophageal injuries not attributable to RF ablation occurred in 9 (10%), with no difference between groups (p = 0.29). There was no difference in AF recurrence between the 2 groups (post 3 months blanking period) after a mean follow up of 6.3 months (p = 0.71).

Conclusion

 HPSD ablation was associated with lower RF ablation and fluoroscopy times compared to LPSD, with comparably low rates of ETI on post ablation endoscopy. Our findings suggest that HPSD ablation is a safe and efficacious approach to PVI. However clinicians should be cognisant of the potential injury risk related to esophageal instrumentation from transesophageal echo/ ETM probes.

Traditional uses, phytochemistry and pharmacology of Bauhinia racemosa Lam.: a comprehensive review

Background

Bauhinia racemosa is not familiarly known in Asian countries due to its limited existence and lack of medicinal information. It is commonly used as a medicine, ornamental plant, fence plant, and fodder for livestock since ancient times. It is also used as a landfill tree to avoid soil erosion of the forest.

Main body

In South India, people cultivate this plant in their premises in order to protect themselves from the effects of thunder. In this review, the various research prospects of this plant have been analyzed and are summarized. The aim of this review is to provide the traditional uses, phytochemicals and pharmacological activities of B. racemosa, and to highlight the current pharmacological developments of this medicinal plant.

Conclusions

The B. racemosa has immense therapeutic potential for treating diseases with both traditional and pharmacological applications. But many traditional uses of B. racemosa have not been validated by current investigations in the aspects of pharmaceutical. Until now, research on phyto-constituents from B. racemosa has not been done in an extensive way. Hence, the identified phytochemicals of B. racemosa should also be subjected to pharmacological studies to illuminate the biological mechanisms of these unreported secondary metabolites for the prevention of diseases or microbial infections and other health disorders of human and animal races.

On detour index of cycloparaphenylene and polyphenylene molecular structures

Cycloparaphenylene is a particle that comprises a few benzene rings associated with covalent bonds in the para positions to frame a ring-like structure. Similarly, poly (para-phenylenes) are macromolecules that include benzenoid compounds straightforwardly joined to each other by C-C bonds. Because of their remarkable architectural highlights, these structures have fascinated attention from numerous vantage focuses. Descriptors are among the most fundamental segments of prescient quantitative structure-activity and property relationship (QSAR/QSPR) demonstrating examination. They encode chemical data of particles as quantitative numbers, which are utilized to create a mathematical correlation. The nature of a predictive model relies upon great demonstrating insights, yet additionally on the extraction of compound highlights. To a great extent, Molecular topology has exhibited its adequacy in portraying sub-atomic structures and anticipating their properties. It follows a two-dimensional methodology, just thinking about the interior plan, including molecules. Explicit subsets speak the design of every atom of topological descriptors. When all around picked, these descriptors give a unique method of describing an atomic system that can represent the most significant highlights of the molecular structure. Detour index is one such topological descriptor with much application in chemistry, especially in QSAR/QSPR studies. This article presents an exact analytical expression for the detour index of cycloparaphenylene and poly (para-phenylene).

Patients' views on a proposed oral cancer screening technology

Brush cytology and telemedicine platforms are used with proven benefits in remote diagnosis of malignancies like cervical cancer. In low-resource settings access to the current standard of care, biopsy and histopathology grading of oral lesions, can be unfeasible. Risk-stratifying early malignant and oral potentially-malignant lesions can help instigate therapeutic treatment and improve prognosis. Therefore, a telecytology platform enabling remote connectivity to specialist centres may aid early detection of oral cancer. We outline head and neck (H&N) cancer patients' views on an oral brush cytology investigation.

Long-term outcomes of index cryoballoon ablation or point-by-point radiofrequency ablation in patients with atrial fibrillation and systolic heart failure

Catheter ablation is an established effective approach for the treatment of atrial fibrillation (AF) in patients with heart failure, however, the role of cryoablation in this setting is unclear. Procedural success and left ventricular systolic dysfunction (LVEF) improvement in patients with LVEF ≤ 45% undergoing index catheter ablation with cryoablation were evaluated. Freedom from AF recurrence was seen in 43% rising to 59% following repeat procedure. There were significant improvements in LVEF and functional status at long-term follow-up. Results were comparable to a contemporaneous cohort of heart failure patients undergoing index ablation with radiofrequency ablation. Cryoablation is an effective first-line AF ablation approach in the setting of heart failure.

On Certain Topological Indices of Three-Layered Single-Walled Titania Nanosheets

AIM AND OBJECTIVE

Nanostructures are objects whose sizes are between microscopic and molecular. The most significant of these new elements are carbon nanotubes. These elements have extraordinary microelectronic properties and many other exclusive physiognomies. Recently, researchers have given the attention to the mathematical properties of these materials. The aim and objective of this research article is to investigate the most important molecular descriptors namely Wiener, edge-Wiener, vertex-edge-Wiener, vertex-Szeged, edge-Szeged, edge-vertex-Szeged, total-Szeged, PI, Schultz, Gutman, Mostar, edge-Mostar, and total-Mostar indices of three-layered single-walled titania nanosheets. By computing these topological indices, materials science researchers can have a better understanding of structural and physical properties of titania nanosheets, and thereby more easily synthesizing new variants of titania nanosheets with more amenable physicochemical properties.

METHODS

The cut method turned out to be extremely handy when dealing with distance-based graph invariants which are in turn among the central concepts of chemical graph theory. In this method, we use the Djokovic ́-Winkler relation to find the suitable edge cuts to leave the graph into exactly two components. Based on the graph theoretical measures of the components, we obtain the desired topological indices by mathematical computations.

RESULTS

In this paper, distance-based indices for three-layered single-walled titania nanosheets were investigated and given the exact expressions for various dimensions of three-layered single-walled titania nanosheets. These indices may be useful in synthesizing new variants of titania nanosheets and the computed topological indices play an important role in studies of Quantitative structure-activity relationship (QSAR) and Quantitative structure-property relationship (QSPR).

CONCLUSION

In this paper, we have obtained the closed expressions of several distance-based topological indices of three-layered single-walled titania nanosheet TNS_3 [m,n] molecular graph for the cases m≥ n and m < n. The graphical validations for the computed indices are done and we observe that the Wiener types, Schultz and Gutman indices perform in a similar way whereas PI and Mostar type indices perform in the same way.