E-learning in medical education: a perspective of pre-clinical medical students from a lower-middle income country.

BACKGROUND: Many of the educational institutions in developed countries have shifted to online learning. While transition from traditional to electronic learning (e-learning) has remained a great challenge in low-middle income countries, where limited resources for teaching and learning are important factors. Medical education involves not only lecturing but also deep understanding through laboratories and patient exposure. The debate about the effectiveness of e-learning in medical education is still in contradiction due to its limitations. This cross-sectional survey was conducted to assess pre-clinical undergraduate medical students' perception of their first online learning in a lower-middle income country. METHODOLOGY: The survey was conducted among the students who had participated in online learning during COVID-19 for at least a year. A total of 824 preclinical medical students who completed the survey from public and private medical universities in Sindh, Pakistan were included in the study. We used a validated online-based questionnaire, distributed through E-mail and social media platforms to assess the perception of students regarding their first online learning experience. RESULTS: The response rate of the survey was 87.9%. The mean age of students was 20.7 ± 3.8 years. 392/824 (47%) were males and 57% were females. Our study indicated that 613/824 (75%) of students were experiencing online learning for the very first time while 631/824 (77%) were facing technical issues like internet accessibility and lack of IT-related skills. 381/824 (46%) were not satisfied with the institute's readiness for online teaching. However, 79% (654/824) of participants were of the idea that traditional learning is more effective in developing their practical skills as compared to e-learning. Of note, 668/824 (81%) showed overall dissatisfaction with e-learning. CONCLUSION: Based on our study findings, we concluded that most students have a negative perception of e-learning. Difficulty in connectivity, electricity issues, less interaction with colleagues and teachers, and issues with the structure of online courses were the most frequently reported problems by the students.

Patterned Photonic Array Based on an Intertwined Polymer Network Functionalized with a Nonenzymatic Moiety for the Visual Detection of Glucose.

A patterned photonic array chip based on an intertwined polymer network (IPN) is proposed for the visual detection of glucose. The IPN networks are composed of photonic and poly(acrylic acid) (PAA) networks. Aminophenylboronic acid, as a nonenzymatic glucose-responsive moiety that can covalently bond to glucose at alkaline pH, forming tetragonal complexes, is immobilized in the PAA network; in hydrogels, this bonding generates Donnan osmotic pressure, resulting in a volumetric increase of the photonic IPN and reflected color change. The photonic band gap wavelength linearly increases with the glucose concentration (in the 1-12 mM range), with a limit of detection of 0.35 mM. The dots of the photonic IPN array respond independently, with high sensitivity and stability, to glucose via color changes; different glucose levels, from hypo- to hyperglycemia, can be visually detected in this way. Serum samples spiked with different glucose concentrations were tested for practical evaluation of the chip. The proposed chip could be utilized as a new biosensor platform for cost-effective and easy visual detection in remote areas, without the need of advanced instruments or technology.

Label- and enzyme-free detection of glucose by boronic acid-coupled poly(styrene-b-acrylic acid) at liquid crystal/aqueous interfaces.

A glucose biosensor was developed based on a 4-cyano-4'-pentylbiphenyl (5CB)-filled transmission electron microscopy (TEM) grid cell by coating poly (styrene-b-acrylic acid) (PS-b-PAA) at the 5CB/aqueous interface and immobilising 3-aminophenyl boronic acid (APBA) on the PAA block chains by N-(3-dimethylaminopropyl)-N-ethylcarbodiimide coupling. Binding events between APBA and glucose were translated into homeotropic-to-planar configurational changes of 5CB, which were observed by polarised optical microscopy (POM) under crossed polarisers. This liquid-crystal-based glucose biosensor exhibited high sensitivity (limit of detection: 0.1 mM), even in complex serum and urine samples, high selectivity (against cholesterol, haemoglobin, and urea), and good stability for 40 d. This new and sensitive glucose biosensor has the advantages of low production cost, a simple immobilisation technique, and easy detection with POM, and may be useful for pre-screening glucose levels in human samples (serum and urine).

Cholesteric Liquid Crystal Droplets for Biosensors.

By utilizing a microfluidics approach, we prepared uniformly sized cholesteric liquid crystal (CLC) droplets from MLC-2132 doped with a chiral dopant (S)-4-cyano-4'-(2-methylbutyl)biphenyl (CB15). We studied the helical structures and reflecting color patterns of high- and low-dopant CLC droplets coated with poly(vinyl alcohol) (PVA) and sodium dodecyl sulfate (SDS). One central large spot with reflecting color in the CLC droplets (initially coated with PVA for planar anchoring) changed to many small spots with the same reflecting color (chicken-skin pattern) when an SDS aqueous solution was introduced to increase the homeotropic anchoring power. These small spots subsequently merged into several spots (flashlight pattern) with time. The CLC droplets coated with poly(acrylic acid)-b-poly(4-cyanobiphenyl-4'-oxyundecyl acrylate) (PAA-b-LCP) (CLCPAA droplets) were pH-responsive. Their helical structure and the reflecting color pattern changed because of protonation (at low pH) and deprotonation (at high pH) of the carboxylic group of PAA, which causes the planar (tangential) and perpendicular (homeotropic) orientations, respectively. The CLCPAA droplets immobilized with glucose oxidase (GOx) and cholesterol oxidase (ChO) (CLCPAA-GOx and CLCPAA-ChO droplets, respectively), for glucose and cholesterol detection, exhibited high sensitivity (0.5 and 2.5 µM for the CLCPAA-GOx and CLCPAA-ChO droplets, respectively), good selectivity, and fast response (≤4 s). Further optimization will enhance their performance as biosensors. With this novel approach, detection is possible by observing the coloring pattern of CLC droplets, without the crossed polarizers that are necessary for nematic LC biosensor systems.

The development of a cholesterol biosensor using a liquid crystal/aqueous interface in a SDS-included ß-cyclodextrin aqueous solution.

Sodium dodecyl sulphate (SDS) including ß-cyclodextrin (ß-CD) (ß-CDSDS) was used to detect cholesterol at the 4-cyano-4'-pentylbiphenyl (5CB)/aqueous interface in transmission electron microscopy (TEM) grid cells. The ß-CD acts as a host for SDS (guest). The guest SDS enclosed within the ß-CD cavity was replaced with cholesterol by injecting cholesterol solution into the TEM cell at concentrations greater than 3 µM. The replacement of SDS with cholesterol was confirmed by pH measurement and high performance liquid chromatography (HPLC). The SDS excluded from the ß-CD altered the planar orientation of the 5CB confined within the TEM grid cell to a homeotropic orientation. This planar-to-homeotropic transition was observed using a polarized optical microscope under crossed polarizers. This convenient TEM grid cell provides a new method for the selective detection of cholesterol without immobilization of the detecting receptors (enzyme, antibody, or aptamer) or the use of sophisticated instruments.