Hydrogeochemical Assessment of Groundwater for Drinking and Agricultural Use: A Case Study of Rural Areas of Alwar, Rajasthan.

Groundwater contributes substantially to the development of arid and semi-arid regions around the globe. The present study integrates groundwater quality and its suitability for drinking and irrigation around Alwar city of Rajasthan state, where agriculture is the major land use. The application for drinking was assessed by comparing the observed value with prescribed standards of WHO. Groundwater was found suitable for drinking at most of the locations. The suitability of groundwater for irrigation was determined by calculating ion-based ratios and comparing them against the suggested ratios and indices for agricultural quality. Suitability for irrigation was assessed against electrical conductivity (EC), percentage sodium (%Na), residual Na2CO3 (RSC), per cent soluble sodium (SSP), sodium adsorption ratio (SAR), Mg hazard and permeability index (PI) etc., and the quality was compromised for EC, %Na and Mg Hz. Since the soil was sandy, the groundwater was found suitable for irrigation over long-term use, with the only problem of magnesium hazard. Based on the different ratios of anions and cations, silicate weathering was observed to be regulating groundwater chemistry, and the groundwater belonged to mixed CaMgCl and CaHCO3- type based on Piper's classification and relative abundance of ions. Further, meteoric genesis classification showed that the groundwater in the study region had direct base exchange and shallow meteoric water percolation. Presence of kaolinite and quartz minerals in soil confirmed that silicate weathering is the major process controlling groundwater chemistry.

Greening up organic reactions with caffeine: applications, recent developments, and future directions.

Numerous studies in the field of alkaloid chemistry have provided researchers with valuable insights into their unique properties as catalysts. Among the diverse natural catalysts, caffeine has emerged as a green, expedient, and biodegradable catalyst with high efficiency and applicability. Interest in using caffeine as a catalyst has burgeoned over the past few years with its role in diverse multicomponent reactions. Preparation of its imidazolium salts and further conversion to Nitrogen Heterocyclic Carbene (NHC) ligands and ionic liquids offers new paradigms. Caffeine has also played a multifaceted role as a support material in influencing the structural properties of nanoparticles. We hope that the chemistry of caffeine and its applications for sustainable organic transformations discussed in this review will stimulate new thinking and open new avenues in this field.

A Study of Changes in Refractive Status Pre and Post Pterygium Surgery among Patients of Tertiary Care Hospital of Ahmedabad City

Background : Pterygium is a fibrovascular subconjunctival tissue also called Tenon’s Capsular growth occurring mostly in the palpebral fissure area from the nasal aspect towards the limbus over the Cornea and in this process the Corneal Pathology is changed especially the epithelium and bowman’s layer of the cornea are destroyed1. A major problem seen in most of postpterygium surgery is the complication of recurrence and it is usually seen in young patients with fleshy large pterygium1. This issue is addressed by Pterygium Surgery with either Conjunctival Autograft (CAG) or Amniotic Membrane Graft (AMG)1. Stem cells are present in limbal conjunctiva and in amniotic membrane, which provide a barrier between cornea and conjunctiva, preventing regrowth and also provide a smooth regular surface to the eyeball2. another reason and technique to prevent recurrence is by excising the pathological part of conjunctiva and resecting tenon’s capsule up to far periphery2. Aims and Objectives : The aim of the study is to investigate pre-operative and postoperative difference between the amount of astigmatism prior to the surgery and after the Pterygium Excision Surgery with either CAG or AMG. Materials and Method : A prospective cross-sectional study was undertaken of 26 cases, who underwent Pterygium Surgery under local anaesthesia with Conjunctival Autograft or Amniotic Membrane Graft for a period of one year in a Tertiary Healthcare Hospital. Pre-operative Best Corrected Visual Acuity, Anterior Segment Examination, Slit Lamp Examination, Dilated Retinoscopy and Fundus examination, Keratometry and Post mydriatic refraction was done. Then the patient underwent Pterygium Excision Surgery with Conjunctival Autograft or Amniotic Membrane Graft under local anaesthesia. All patients were re-examined 1 month after the surgery for final Refraction and Keratometry. Result : Among total of 26 patients, the comparison between pre- and postoperative values of Refraction and of Corneal Astigmatism was performed using z test. The pre-operative Mean for Astigmatism was 1.70 and SD was 0.43. The postoperative mean for Astigmatism was 0.57 and SD was 0.26. The pre-operative Keratometry mean was 2.73 and SD was 0.14. The Post operative Keratometry Mean was 1.50 and SD was 0.55. (p value, 0.0001) Conclusion: Pterygium is a lesion which also affects the ocular surface, thus leading to one of the causes for ocular surface abnormality. Pterygium surgeries results in elimination of the Pulling Factor and Corneal Curvature thus reducing or eliminating Astigmatism and thereby providing better visual restoration and cosmetic outcome