Dry eye among medical students before and during COVID-19

Purpose

Dry eye is a multifactorial disease of the ocular surface. It showed an increased incidence during the pandemic situation, which may be due to long hours of exposure to electronic gadgets. We aimed to find the prevalence of dry eye disease among medical students during the coronavirus disease 2019 (COVID-19) pandemic and pre-pandemic periods.

Methods

This was a cross-sectional study conducted in a tertiary care teaching institute. This was an institution-based, cross-sectional study conducted among medical students. A modified Ocular Surface Disease Index (OSDI) questionnaire was used to find the severity and prevalence of dry eye disease. Considering 95% confidence interval (CI) and prevalence as 50%, the calculated sample size was 271. Online responses were collected and entered in an Excel sheet. The Chi-square test, univariate and multivariate logistic regression were used for statistical analysis.

Results

Data were collected from 271 medical students; the prevalence of dry eye disease was 41.5 and 55.19 during the pre-pandemic and pandemic periods, respectively. There was a significant rise in dry eye disease cases during the pandemic when compared to pre-pandemic period (P < 0.05). The odds of getting dry eye disease were 1.7 times more during the pandemic than pre-pandemic.

Conclusion

The lockdown situation during the pandemic forced people to use electronic gadgets for work, recreation, and academics. Prolonged screen time predisposes to the development of dry eye disease.

Atypical corneal clouding in mucopolysaccharidoses

The etiology for corneal clouding from the birth is varied and includes conditions such as sclerocornea, birth trauma, corneal ulcer, Peters anomaly, and rare causes like mucopolysaccharidoses (MPS). The lysosomal storage disorders are associated with a varied ocular manifestation including bilateral corneal clouding which is often mild and stippled except in few cases like Hunter syndrome where cornea is often clear. We report a case of MPS Type I S (MPS 1) with near-normal visual acuity and bilateral dense corneal clouding with sparing of central 3 mm of cornea. The patient also had typical facial and skeletal abnormalities of lysosomal storage disorder. To our best knowledge, MPS 1 with marked corneal clouding with sparing of central cornea is very rare and has not been reported. This case report emphasizes on the atypical ocular presentation of MPS and the need for ophthalmological screening in the storage disorders.

Effective adsorption of crystal violet onto aromatic polyimides: Kinetics and isotherm studies

The motive of this work is to synthesis aromatic polyimides by a two-step poly condensation process and the prepared aromatic polyamides (APIs) is been used as an effective functionalized adsorbent for the removal of carcinogenic crystal violet (CV) from aqueous medium. The adsorption efficiency of the APIs was enhanced by incorporation different functional moieties (varying aromatic dianhydrides with -O-, -(CF₃)₂-, -(CH₃)₂-) in the polymer structure. The initial and final concentration of CV was measured using UV-Vis spectrometer. The adsorption process was optimized by varying the parameters such as the effect of solution pH, contact time, initial dye concentration, and adsorbent dosage. Kinetics and isotherms of the adsorption system were appraised using data obtained from effect of contact time and initial dye concentration with corresponding empirical modelling techniques respectively. The evaluated results of the adsorption kinetic studies confirmed that the adsorption of API onto CV is followed a pseudo-second-order kinetic model. The adsorption behaviour and their interactions between APIs and CV are well established. The experimental results of this research output could be confirmed that APIs is a very effective adsorbent for the removal of cationic dye from aqueous.

Optimization of NaCl based spray corrosion test process parameters of heat treated hybrid metal matrix composites

ABSTRACT. Aluminium hybrid metal matrix composites (AHMMCs) have widely employed in aerospace, transportation, and automotive applications since for their excellent mechanical qualities and high corrosion resistance. In this research, Al8079 is selected as a matrix material. The titanium diboride (TiB2) is selected as hard reinforcement and molybdenum disulfide (MoS2) is used as soft reinforcement. The Al8079/15 wt.% TiB2/x wt.% MoS2 (x = 0, 2.5, 5 and 7.5) HMMCs are fabricated by using stir casting. The composites are heat treated under T6 condition. The density and micro hardness tests are conducted. The optimization on NaCl based spray corrosion test process parameters is done using grey relational analysis (GRA). The selected input process parameters are Al8079/15 wt.% TiB2/wt.% MoS2 (x = 0, 2.5 and 5), pH value of NaCl solution (x = 6, 9 and 12), hang time (x = 24, 48, and 72 h) and pressure (x = 0.7, 0.9 and 1.1 kg/cm2). The selected response parameters are micro hardness, mass loss and wear loss. The L9 Taguchi design is used for optimization. The wear test is conducted at the constant speed of 0.5 m/s, loading rate of 20 N and the sliding distance of 1000 m. The percentage of improvement of GRG from initial setting to experimental is 10.4%.   KEY WORDS: Reinforcement, Stir casting, Optimization, GRA, NaCl Bull. Chem. Soc. Ethiop. 2022, 36(4), 903-914.                                                         DOI: https://dx.doi.org/10.4314/bcse.v36i4.15

Comparative Whole-Genome Sequence Analyses of Fusarium Wilt Pathogen (Foc R1, STR4 and TR4) Infecting Cavendish (AAA) Bananas in India, with a Special Emphasis on Pathogenicity Mechanisms

Fusarium wilt is caused by the fungus Fusarium oxysporum f. sp. cubense (Foc) and is the most serious disease affecting bananas (Musa spp.). The fungus is classified into Foc race 1 (R1), Foc race 2, and Foc race 4 based on host specificity. As the rate of spread and the ranges of the devastation of the Foc races exceed the centre of the banana’s origin, even in non-targeted cultivars, there is a possibility of variation in virulence-associated genes. Therefore, the present study investigates the genome assembly of Foc races that infect the Cavendish (AAA) banana group in India, specifically those of the vegetative compatibility group (VCG) 0124 (race 1), 0120 (subtropical race 4), and 01213/16 (tropical race 4). While comparing the general features of the genome sequences (e.g., RNAs, GO, SNPs, and InDels), the study also looked at transposable elements, phylogenetic relationships, and virulence-associated effector genes, and sought insights into race-specific molecular mechanisms of infection based on the presence of unique genes. The results of the analyses revealed variations in the organisation of genome assembly and virulence-associated genes, specifically secreted in xylem (SIX) genes, when compared to their respective reference genomes. The findings contributed to a better understanding of Indian Foc genomes, which will aid in the development of effective Fusarium wilt management techniques for various Foc VCGs in India and beyond.

First report of rhizome rot of banana caused by Klebsiella variicola in India

Rhizome rot or soft rot disease is one of the major problems in banana (Musa spp.) cultivation, as it causes germination failure and death of early stage plants. A roving survey conducted during 2017 to 2019 in the major banana growing states of India indicated a 5-30% incidence of rhizome rot in commercial cultivars. The symptoms observed were yellowing of leaves, necrotic drying with or without heart rot, and yellow or brown water soaked spots with dark brown margins in the rhizomes. Decay of tissues, cavity formation and brown ooze with foul smell, and toppling were also observed. To isolate bacteria, dissected diseased tissues were surface sterilized and plated on Crystal Violet Pectate (CVP) medium. Of 60 samples plated on CVP medium, three samples collected from cvs. NeyPoovan-AB (Karur, Tamil Nadu, 10°56'36.8"N;78°24'12.5"E), Grand Naine-AAA (Tiruchirappalli, Tamil Nadu, 10°47'26.1"N;78°34'14.8"E) and Thellachakkarakeli-AAA (East-Godavari, Andhra Pradesh, 16°51'32.1"N;81°46'08.4"E), did not yield any bacteria; however, when plated on nutrient agar, they produced whitish to dull white, mucoid, raised, round and translucent colonies, and three isolates were named as NPK-3-48, GTC-5 and 1-1B-3, respectively. Because these colonies were distinct from colonies obtained on CVP medium (which were analyzed and confirmed separately as Pectobaterium sp.) (Gokul et al. 2019), they were further characterized. Amplification of 16S rDNA genes of NPK-3-48, GTC-5 and 1-1B-3 isolates using universal primers (27F 5' - AGAGTTTGATCCTGGCTCAG - 3'; 1492 R 5' - GGTTACCTTGTTACGACTT - 3') and rpoB gene (Rosenblueth et al. 2004) was carried; the amplicons were sequenced and deposited in NCBI (Accessions MW036529-MW036531; MW497572-MW497574). Phylogenetic analysis of rpoB clearly showed that the isolates NPK-3-48, GTC-5, 1-1B-3 are Klebsiella variicola (Rosenblueth et al. 2004) Besides, biochemical tests also indicated that all three isolates were Gram negative, catalase positive, oxidase negative and able to utilize glucose, maltose and citrate (Ajayasree and Borkar 2018). Therefore, the above said morphological, molecular and biochemical analyses carried out indicated that NPK-3-48, GTC-5, 1-1B-3 are of K. variicola. Earlier, K. variicola causing soft rot has been reported on banana in China (Fan et al. 2016), plantain soft rot in Haiti (Fulton et al. 2020) and carrot soft rot in India (Chandrashekar et al. 2018). For pathogenicity tests, these three isolates were grown in nutrient broth for 48 h at 37±1°C and the cells were harvested by centrifugation. Five milliliters of the culture suspension (2×108 CFUmL-1) taken in a syringe was injected into rhizomes of three month old tissue cultured Grand Naine plants. Each bacterial isolate was injected into eight banana plants at soil level. Appropriate controls were maintained. Inoculated plants were maintained in a glasshouse at 32±2°C and after 30-35 days, rhizome rot symptoms appeared in all the three bacterial isolates inoculated plants but in none of the control plants. The Koch's postulates were proved by re-isolation and identification.To the best of our knowledge, this is the first report of K. variicola causing rhizome rot disease of banana in India.

Identification of sources resistant to a virulent Fusarium wilt strain (VCG 0124) infecting Cavendish bananas

Bananas are vital for food security in many countries, and half of banana production relies solely on ‘Cavendish’ (AAA), which is presently threatened by the fungal pathogen Fusarium oxysporum f. sp. cubense (Foc) tropical race 4. This particular virulent Foc strain was also found to attack other banana varieties of commercial importance. As there is no single effective management practice available so far, this study was undertaken to determine resistant sources from the genotype collection available at the ICAR-National Research Centre for Banana, Tiruchirappalli, Tamil Nadu, India for direct use by farmers and/or in breeding programmes to develop resistant hybrids. A total of 258 genotypes of different ploidies and genomic constitutions were tested against Foc race 1 (VCG 0124). In total, 19 genotypes (AA Unique-6, BB type-2, AAA Unique-1, AAA Cavendish-1, AAB Mysore-3, AAB Pome-1, AAB Plantain-4 and AAAB-1) were found to be immune; eight genotypes (AA Unique-1, BB type-3, AAA Cavendish-1, AAB Mysore-1, AAB Unique-1, AAB Plantain-1) were highly resistant; and nine genotypes (AA Unique-1, AAA Cavendish-3, AAB Silk-1, AAB Pome-4) were resistant. The genotypes that are resistant to the virulent Foc race 1 (VCG 0124) strain can be exploited directly for commercialization and/or in breeding programs to develop resistant hybrids.

Draft Genome of Fusarium oxysporum f. sp. cubense Strain Tropical Race-4 Infecting Cavendish (AAA) Group of Banana in India

Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. cubense, is the most serious pandemic disease of banana. In this study, we report the draft genome of F. oxysporum f. sp. cubense vegetative compatibility group (VCG) 01213/16 of strain tropical race 4 (TR4) that infects the Cavendish (AAA) group of banana collected from the subtropical region in India. The genome assembly of SFoc TR4 comprises 47,384,463 bp with 4,034 contigs and 15,508 protein-coding regions. Based on VCG analysis, the fungal isolate belongs to F. oxysporum f. sp. cubense TR4 but the genome sequence of SFoc TR4 shows differences in secreted-in-xylem (SIX) protein gene clusters (specifically, SIX8) in comparison with the reference genome of F. oxysporum f. sp. lycopersici and F. oxysporum f. sp. cubense TR4.

Development of telehealth dialogues for monitoring suicidal patients with schizophrenia: consumer feedback

Suicide is a health concern among individuals with schizophrenia. A telehealth system for monitoring suicidal patients with schizophrenia was developed using the Health Buddy©. The existing dialogues were improved using an expert panel; the new dialogues were tested in 10 consumers with schizophrenia and a history of suicidal behavior. Using qualitative editing, several themes emerged: (1) Certain topics elicited strong emotional responses; (2) There were concerns with confidentiality; (3) Some content was too vague and (4) There were problems with vocabulary and wording. The process yielded information for improving the intervention and demonstrated that the approach is feasible in this population.

Bioefficacy, residue dynamics and safety assessment of the combination fungicide trifloxystrobin 25% + tebuconazole 50%-75 WG in managing early blight of tomato (Lycopersicon esculentum Mill.)

This paper reports the in vitro and in vivo bioefficacy of a combination fungicide trifloxystrobin (25%) + tebuconazole (50%) against early blight disease of tomato (Lycopersicon esculentum Mill.) caused by Alternaria solani and their corresponding pre-harvest intervals (PHI) with reference to the maximum residue limits (European Union). Bioefficacy of the test fungicide combination revealed that in vitro conditions manifested the best control (75.1%) at 350 mg kg(-1) against 76.2% control under field conditions. A sample preparation method based on ethyl acetate extraction and estimation by LC-MS multiple reaction monitoring (MRM) was validated in tomato fruits at 0.01 mg/kg and dissipation studies were conducted in field at single and double doses. The residues of both the compounds on all the sampling days were below the European Union maximum residue limits (EU-MRLs) and the maximum permissible intakes (MPIs) were calculated on the basis of prescribed acceptable daily intake (ADI). The combined bioefficacy and residue dynamics information will support label-claim of this fungicide combination for the management of early blight in tomato.

Pyramiding transgenic resistance in elite indica rice cultivars against the sheath blight and bacterial blight

Elite indica rice cultivars were cotransformed with genes expressing a rice chitinase (chi11) and a thaumatin-like protein (tlp) conferring resistance to fungal pathogens and a serine-threonine kinase (Xa21) conferring bacterial blight resistance, through particle bombardment, with a view to pyramiding sheath blight and bacterial blight resistance. Molecular analyses of putative transgenic lines by polymerase chain reaction, Southern Blot hybridization, and Western Blotting revealed stable integration and expression of the transgenes in a few independent transgenic lines. Progeny analyses showed the stable inheritance of transgenes to their progeny. Coexpression of chitinase and thaumatin-like protein in the progenies of a transgenic Pusa Basmati1 line revealed an enhanced resistance to the sheath blight pathogen, Rhizoctonia solani, as compared to that in the lines expressing the individual genes. A transgenic Pusa Basmati1 line pyramided with chi11, tlp, and Xa21 showed an enhanced resistance to both sheath blight and bacterial blight.