Imperceptible learners: Students' reasons for keeping webcams off and strategies to address students' challenges.

BACKGROUND: "Should students keep their webcams on or off during synchronous online classes?" is an unanswered question with educators' opinions divided on this aspect. Along with educators' perspectives, it is also important to unfold students' perspectives on this question. The objectives of this study were to determine the routine and opinion of students' regarding webcam usage and identification of students' reasons for not using webcams during online learning. MATERIALS AND METHODS: A cross-sectional study was carried out at Margalla Institute of Health Sciences, Rawalpindi, Pakistan. Census was done for data collection by including all dental students (n = 180) enrolled at the institute attending synchronous online preclinical and clinical operative dentistry classes. Data collection was carried out using a self-administrated questionnaire. Descriptive analysis was used to describe survey item responses. Pair-wise differences between demographic categories (female vs. male, and preclinical vs. clinical) were analyzed using the Pearson Chi-Square test. Correlation of routine and opinion with students' reasons were done using Spearman correlation. Ordinal regression analysis was done to associate routine and opinion with reasons. The level of significance (P value) was set at 0.05. RESULTS: Out of 180 students, 141 submitted the survey form, with a response rate of 77.47%. The majority of the students (n = 117, 83%) used to keep their webcams off during online classes and were (n = 69, 48.9%) of the opinion that webcams should be kept off during online classes. The most common reasons for keeping the webcam off during online classes were "comfort" (n = 87, 61.7%) and "distractions" (n = 84, 59.6%). A statistically significant association of gender was obtained, with females more likely than males due to distraction, self-consciousness, and appearance (P = 0.000, 0.003, and 0.016, respectively). The odds of gender highly influenced routine use of cameras, and this was statistically significant (OR: 3.478, P = 0.011). Students tended to keep their webcam off when they were inattentative during online classes (OR; 3.743, P < 0.001). CONCLUSION: The majority of the students did not agree to keep the webcam on during online synchronous learning. The main reasons for students' reluctance to keep the webcam on were self-consciousness, surrounding consciousness, distractions, and technological issues. Students can be encouraged to turn the webcam on by framing strategies according to students' concerns.

Incivility in online learning environment: Perception of dental students and faculty.

OBJECTIVES: The objectives of this study were to assess the extent of incivility and perception of dental students and faculty regarding uncivil behaviors in the online learning environment. METHODS: Incivility in online environment (IOLE) survey was used to collect data from dental students (n = 232) and faculty (n = 35) at Margalla Institute of Health Sciences, Rawalpindi, Pakistan from September to December 2021. A 4- point Likert scale was used for respondents to indicate their perceptions regarding incivility in IOLE, and a list of students' and faculty's uncivil behaviors. Descriptive analysis, chi-square test, and Spearman's correlation coefficient were used for data analysis. The level of significance was kept at ≤0.05. RESULTS: The majority of the students reported online incivility as either "a moderate or serious problem" (n = 103, 72.0%), and the majority of faculty (n = 12, 56%) reported incivility as "no to a mild problem" (p = 0.018). Both students and faculty agreed that students are more likely to engage in uncivil behavior in OLE as compared to faculty. Various forms of rude/threatening comments and posting ambiguous or vague responses that do not add meaning to the online discussion were considered uncivil student behaviors by both students and faculty (p ≤ 0.05). Assigning grades without providing useful feedback and threatening to fail students for not complying with faculty's demands were perceived as uncivil faculty behaviors (p ≤ 0.05). Female students and students with less self-reported expertise in online learning had greater mean scores for faculty uncivil behaviors (p ≤ 0.05). CONCLUSION: Incivility exists in OLE in dentistry with the more likely engagement of students in uncivil behaviors. With the increasing use of online platforms for education in dentistry, there is a need for further research and training courses for both students and faculty to reduce the extent of incivility and create a healthy and conducive learning environment.

Impact of end capped modification on BT-CIC molecule for high-performance photovoltaic attributes: a DFT approach.

With the aim of utilizing structural modeling techniques to design efficient organic solar cells, a quantum chemical density functional theory (DFT) and its time-dependent DFT (TD-DFT) study have been carried out for the examination of the photovoltaic properties of four BT-ClC-based novel non-fullerene acceptor (NFA) molecules. The designed entities (BT1-BT4) have an A-π-D-π-A configuration with seven fused ring-based BDT central core and newly substituted peripheral acceptor moieties. The optical parameters (absorption maxima, light-harvesting efficiency, first excitation energies, and dipole moments), electronic properties (frontier molecular orbitals, density of states, and molecular electrostatic potential), and charge transfer characteristics (open-circuit voltage, transition density matrix, and fill factor) of the investigated molecules were evaluated using the selected B3LYP/6-31G (d,p) level of theory. The systematic computational analysis reveals that under the influence of terminal acceptor groups, there is an augmentation in the absorption range, and reduction in the band gap values. The electron withdrawing effect of acceptor moieties is evident from the electronic density distribution on the HOMO-LUMO orbitals, along with the density of state (DOS) graphs. Transition density matrix (TDM) analyses reveal consistent charge transfer in the newly devised entities. Reorganization energies computed for electron and hole are significantly lower than the reference, making the transfer of charge carriers efficient. Open-circuit voltage (Voc) of reported acceptor entities, theoretically computed with PTB7-Th donor, revealed maximum output. Furthermore, the estimated fill factor (FF) of the investigated molecules predicted an increase in power conversion efficiencies. Consequently, all the computed parameters favor the applicability of our designed molecules in the field of organic photovoltaics by virtue of their excellent charge mobilities, increased absorption maximum values, and reduced band gaps.

Tuning of diphenylamine subphthalocyanine based small molecules with efficient photovoltaic parameters for organic solar cells.

In this theoretical research, four donor molecules with diphenylamine subphthalocyanine (SubPc) as a common core, flanked with various electron-withdrawing groups at the central position containing Methyl-2-cyanoacrylate in C1, 3-methyl-5-methylene-2-thioxothiazolidin-4-one in C2, 2-(2-methylene-1-oxo-1H-inden-3(2H)-ylidene) malononitrile in C3, and Methyl-2-(5-methylene-4-oxo-2-thioxothiazoliden-3-yl) acetate in C4, have been designed. To analyze photovoltaic applications of all the studied molecules (C1-C4), quantum chemical simulations i.e., absorption profiles, frontier molecular orbitals (FMOs), the density of states (DOS), transition density matrix, and open-circuit voltage, have been performed availing DFT and TD-DFT approach with selected B3LYP functional /6-31G (d,p) level of theory. Among all the substituted molecules, C3 revealed highest molar absorption coefficient (601 nm), efficient electron density transfer in FMOs, and lowest energy band gap (1.70 eV) owing to the elongated conjugation along with the compelling electron-withdrawing nature of its axial acceptor moiety. All investigated molecules showed profound peaks in the visible region of the absorption spectrum as well as had low electron and hole mobilities in contrast to that of the reference (R) molecule. The observed binding energies (in electron-volt) of C2 (0.67), C3 (0.10), and C4 (0.47) molecules are found to be lower than R. Hence, these findings reveal that all designed candidates (C1-C4) could be effective and favorable applicants to enhance the energy efficiency of small molecule (SM) based organic solar cells (OSCs).

Tuning of a A-A-D-A-A-Type Small Molecule with Benzodithiophene as a Central Core with Efficient Photovoltaic Properties for Organic Solar Cells.

With the aim of upgrading the power conversion efficiency of organic solar cells (OSCs), four novel non-fullerene, A1-A2-D-A2-A1-type small molecules were designed that are derivatives of a recently synthesized molecule SBDT-BDD reported for its efficient properties in all-small-molecule OSCs (ASM-OSCs). Optoelectronic properties of the designed molecules were theoretically computed with a selected CAM-B3LYP functional accompanied by the 6-31G(d,p) basis set of density functional theory (DFT), and excited-state calculations were performed through the time-dependent self-consistent field. The parameters of all analyzed molecules describing the charge distribution (frontier molecular orbitals, density of states, molecular electrostatic potential), absorption properties (UV-vis absorption spectra), exciton dynamics (transition density matrix), electron-hole mobilities (reorganization energies), and exciton binding energies were computed and compared. All the designed molecules were found to be superior regarding the aforesaid properties to the reference molecule. Among all molecules, SBDT1 has the smallest band gap (3.88 eV) and the highest absorption maxima with broad absorption in the visible region. SBDT3 has the lowest binding energy (1.51 eV in chloroform solvent) ensuring easier and faster dissociation of excitons to produce free charge-carriers and has the highest open-circuit voltage (2.46 eV) with PC61BM as the acceptor. SBDT1 possesses the highest hole mobility because it has the lowest value of λ+ (0.0148 eV), and SBDT4 exhibits the highest electron mobility because it has the lowest value of λ- (0.0146 eV). All the designed molecules are good candidates for ASM-OSCs owing to their superior and optimized properties.

Induction of Erythrocyte Shrinkage by Omeprazole.

Omeprazole, a proton pump inhibitor blocks the H+/K+-ATPase channels of gastric parietal cells. It is used for the treatment of peptic ulcer. Prolonged use of omeprazole may involve in inducing anemia. The key marker of eryptosis includes membrane blebbing, cell shrinkage and phosphatidylserine (PS) exposure at the cell surface. In current study, the eryptotic, oxidative as well as hemolytic effects of therapeutical doses (0.5, 1 and 1.5 µM) of omeprazole were investigated after exposing erythrocytes for 48 hours. Investigation of eryptosis was done by cell size measurement, PS exposure determination and calcium channel inhibition. As a possible mechanism of omeprazole induced eryptosis, oxidative stress was investigated by determining the catalase, glutathione peroxidase and superoxide dismutase activities. Similarly, necrotic effect of omeprazole on erythrocytes was also evaluated through hemolysis measurement. Results of our study illustrated that 1.5 µM of omeprazole may induce significant decrease in superoxide dismutase, glutathione peroxidase and catalase activities as well as triggered the erythrocytes shrinkage, PS exposure and hemolysis. Role of calcium was also confirmed in inducing erythrocyte shrinkage. It is concluded that the exposure of erythrocytes with 1.5 µM omeprazole may enhance the rate of eryptosis and hemolysis by inducing oxidative stress.

Stimulation of Erythrocyte Membrane Blebbing by Naproxen Sodium.

Naproxen sodium is a nonsteroidal anti-inflammatory drug (NSAID) having antipyretic and analgesic properties, mainly used for the treatment of rheumatoid arthritis and osteoarthritis. Eryptosis is an alternative term used for suicidal erythrocyte death. In the current study, eryptotic effect of naproxen sodium characterized by membrane blebbing was investigated in erythrocytes after 48 hours of treatment with different concentrations (1-25 µM). The experimental work related to investigation of eryptosis was done by cell size measurement and confirmation of calcium role in the induction of membrane blebbing. As a possible mechanism of eryptosis, oxidative stress induced by naproxen sodium was determined by catalase, glutathione peroxidase, and superoxide dismutase activities. Similarly, hemolytic effect of naproxen sodium was also determined by hemolysis measurement. Results of our study illustrated that the therapeutic doses (10-25 µM) of naproxen sodium induce oxidative stress, confirmed by significant decrease in superoxide dismutase, catalase, and glutathione peroxidase activities that lead to the triggering of cell death by eryptosis and hemolysis.