Self-directed learning: Alternative for traditional classroom learning in undergraduate ophthalmic education during the COVID-19 pandemic in China.

In recent years, the COVID-19 pandemic has led to a shift in medical education from traditional face-to-face to online or remote learning, which provided challenges to faculty and students that have traditionally given face-to-face instruction. Self-directed learning (SDL) has gained popularity in undergraduate education such as nursing and adult education. Although the application of SDL in many medical teachings is practical, the application of SDL in undergraduate ophthalmology education has not been well investigated. COVID-19 pandemic led to changes in the learning style of undergraduate medical students to adapt to the shift from traditional classroom learning (TCL) to online or remote learning. Self-directed learning is a process in which individuals take the initiative in diagnosing their learning needs, formulating learning goals, identifying resources for learning, choosing and implementing appropriate learning strategies and evaluating learning outcomes. This study compared students' perspectives and study outcomes of the SDL and TCL to preliminarily investigate the effect of SDL in undergraduate ophthalmology education. The students showed equal perspectives and satisfaction with both learning models. There was no difference in learning outcomes at the end of the study. The students with different interests in ophthalmology had different perspectives on SDL and TCL. Self-directed learning is an essential alternative to traditional classroom learning in undergraduate ophthalmic education during the COVID-19 pandemic in China.

The Incidence and Risk Factors for Dry Eye After Pediatric Strabismus Surgery.

INTRODUCTION: This study aimed to investigate the incidence and risk factors for dry eye after pediatric strabismus surgery. METHODS: Children aged 5-12 years who underwent strabismus surgery were included in this single-center, prospective, cohort study. The ocular surface assessments were conducted 1 day before and 1, 4, and 8 weeks after surgery. The main outcome measures were the incidence of dry eye after strabismus surgery and associated risk factors. RESULTS: A total of 84 eyes (48 children) that underwent strabismus surgery were included in the study. The mean age at surgery was 7.21 years. The incidence of dry eye was 47.62% at 1 week, 10.71% at 4 weeks, 0% at 8 weeks after surgery. The preoperative tear breakup time (BUT) was lower in the dry eye group than that in the non-dry eye group (P ≤ 0.01). The univariate analysis showed that preoperative BUT was significantly associated with the incidence of dry eye after pediatric strabismus surgery (odds ratio [OR] 0.647, confidence interval [CI] 0.503-0.833, P ≤ 0.01). CONCLUSIONS: Dry eye commonly occurs after pediatric strabismus surgery. Tear film instability is more common than deficient aqueous tear production in patients with dry eye after surgery. Children with a low preoperative BUT are more likely to develop dry eye after strabismus surgery.

Effect of the BOPPPS model combined with case-based learning versus lecture-based learning on ophthalmology education for five-year paediatric undergraduates in Southwest China.

BACKGROUND: To investigate the effect of the bridge-in, objective, preassessment, participatory learning, post assessment, and summary (BOPPPS) model combined with case-based learning (CBL) on ophthalmology teaching for five-year paediatric undergraduates. METHODS: The effects of the BOPPPS model combined with CBL (BOPPPS-CBL) and traditional lecture-based learning (LBL) on ophthalmology teaching were compared among students in a five-year programme. The questionnaire surveys of the students were collected and statistically analysed after the class. The final examination scores, including on elementary knowledge and case analysis, in the two groups were analysed. RESULTS: There were no statistically significant differences between the teachers and students in the baseline data. More students agreed that the BOPPPS-CBL model helped develop their problem-solving skills, analytical skills and motivation for learning better than the LBL model. There was no significant difference in learning pressure between the two groups. The final examination scores of the BOPPPS-CBL group were significantly higher than those of the LBL group. The overall course satisfaction of the BOPPPS-CBL group was obviously higher than that of the LBL group. CONCLUSIONS: The BOPPPS-CBL model is an effective ophthalmology teaching method for five-year paediatric undergraduates.

Severe ophthalmia neonatorum in Southwest China: a 5-year review of demographics, microbiological results, and risk factors.

PURPOSE: To evaluate the microbiological characteristics and risk factors of severe ophthalmia neonatorum (ON) in Southwest China. METHODS: In this retrospective review, data on demography, microbiological results, and risk factors were analyzed. Data were obtained from medical records of patients with severe ON treated at Children's Hospital of Chongqing Medical University from January 2015 to December 2019. To understand the risk factors for severe ON, maternal and neonatal factors were compared between the severe and non-severe ON groups. RESULTS: A total of 1397 neonates with ON were included, of whom 12% (n = 172) had severe ON, and 88% (n = 1225) had non-severe ON. Microbial detection and drug susceptibility tests were performed on 169 patients with severe ON. Culture results were positive for 76 patients, with gram-positive bacteria in 71.1% (n = 54), gram-negative bacteria in 25.0% (n = 19), and multiple microorganisms in 3.9% (n = 3) neonates. The most commonly detected organisms were Staphylococcus aureus (29%) and Staph. epidermis (27%), followed by Escherichia coli (8%). Neisseria gonorrhea (8%), Moraxella catarrhal (5%), Streptococcus pneumoniae (4%), Haemophilus influenza (4%), and Chlamydia trachomatis (1%). The main risk factors for severe ON were obstruction of the nasolacrimal duct (χ2 = 10.794, P = 0.001), meconium aspiration syndrome (χ2 = 6.252, P = 0.012), and cesarian section (χ2 = 5.118, P = 0.024). Neonatal ocular prophylaxis was a protective factor for severe conjunctivitis (χ2 = 6.905, P = 0.009). CONCLUSIONS: Staphylococcus is the most common pathogen of severe ON. Nasolacrimal duct obstruction (NLDO) is a risk factor for ON.

A "4D" systemic view on meridian essence: Substantial, functional, chronological and cultural attributes.

The term Jingluo, translated as meridian or channel, is a core component of traditional Chinese medicine (TCM) and has played a fundamental role in guiding the clinical practice of acupuncture for thousands of years. However, the essence of the meridian remains elusive and is a source of both confusion and debate for researchers. In this study, a "4D" systemic view on the essence of the meridian, namely substantial, functional, chronological, and cultural dimensions, was proposed based on a review of the ancient medical classics, recent research developments, and results from clinical practice. Previous studies have primarily focused on the substantial dimension of the meridian system, with scant interpretation about its functional domain. Neither systemic data nor evaluations have been adequately documented. Additionally, a limited but increasing number of studies have focused on the chronological and cultural dimensions. More investigations that embody the holistic concept of TCM and integrate the systemic modes and advanced techniques with dominant diseases of TCM need to be performed to obtain a more comprehensive understanding of the essence of meridians. The goal of this study is to yield useful information in understanding the essence of meridians and provide a reference and perspective for further research.

The Influence of Formulation Components and Environmental Humidity on Spray-Dried Phage Powders for Treatment of Respiratory Infections Caused by Acinetobacter baumannii.

The feasibility of using respirable bacteriophage (phage) powder to treat lung infections has been demonstrated in animal models and clinical studies. This work investigated the influence of formulation compositions and excipient concentrations on the aerosol performance and storage stability of phage powder. An anti-Acinetobacter baumannii phage vB_AbaM-IME-AB406 was incorporated into dry powders consisting of trehalose, mannitol and L-leucine for the first time. The phage stability upon the spray-drying process, room temperature storage and powder dispersion under different humidity conditions were assessed. In general, powders prepared with higher mannitol content (40% of the total solids) showed a lower degree of particle merging and no sense of stickiness during sample handling. These formulations also provided better storage stability of phage with no further titer loss after 1 month and <1 log titer loss in 6 months at high excipient concentration. Mannitol improved the dispersibility of phage powders, but the in vitro lung dose dropped sharply after exposure to high-humidity condition (65% RH) for formulations with 20% mannitol. While previously collected knowledge on phage powder preparation could be largely extended to formulate A. baumannii phage into inhalable dry powders, the environmental humidity may have great impacts on the stability and dispersion of phage; therefore, specific attention is required when optimizing phage powder formulations for global distribution.

Thygeson's superficial punctate keratitis (TSPK): a paediatric case report and review of the literature.

BACKGROUND: Thygeson's superficial punctate keratitis (TSPK) is reportedly a rare disease with an insidious onset, numerous remissions and exacerbations, and a long duration. The corneal lesions are elevated, whitish-grey in colour, and granular in the intraepithelium. A few reported cases of TSPK exist, and paediatric experience is limited. Due to the unknown aetiology and controversial treatment strategies for TSPK, we performed a literature review to summarize the criteria for the diagnosis, treatment and prognosis of TSPK to provide a basis for the treatment of TSPK in paediatric patients. CASE PRESENTATION: The clinical course of a boy with TSPK who repeatedly presented with episodes of tearing, photophobia and foreign body sensation in both eyes is described. Irritation was uncontrollable with antiviral and antibiotic medications, and it was managed by corticosteroids. No recurrence was reported at the 1-year follow-up after corticosteroid replacement and tapering. CONCLUSIONS: The clinical features, treatment and prognosis between adult and paediatric TSPK patients have many similarities. The diagnosis of TSPK in children is more difficult, leading to missed diagnosis. TSPK needs to be carefully differentiated from other types of keratitis, especially intraepithelial secondary and other infectious ocular surface diseases.

Influence of Vitamin A deficiency on the transcriptomic profile of rat meibomian glands.

PURPOSE: Vitamin A deficiency (VAD) is associated with chalazion in young children. However, the underlying molecular mechanism remains unclear. In the present study, transcriptome data from rat meibomian glands (MGs) were analyzed to reveal specific molecular responses to VAD. METHODS: Total RNA was extracted and purified for library preparation and transcriptome sequencing. Differentially expressed genes (DEGs) between vitamin A normal (VAN) and VAD rats were analyzed using DESeq software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of DEGs were performed using the GO seq R package and KOBAS software. Real-time quantitative reverse transcription polymerase chain reaction was used to validate the RNA sequencing results. RESULTS: The number of DEGs in the VAD group compared to the VAN group was 3129 (1531 upregulated and 1598 downregulated) in the rat MGs. VAD upregulated a large number of lipid metabolism-related genes. GO analysis showed that the most enriched and meaningful terms were related to lipid metabolism (e.g., "oxidation-reduction process, GO: 0,055,114," "lipid metabolic process, GO: 000,662"). KEGG pathway analysis showed that most of the enriched signaling pathways were involved in lipid metabolism, including the PPAR signaling pathway associated with retinoic acid (RA)-mediated nuclear receptors. CONCLUSION: These findings demonstrate that VAD regulates the expression of numerous genes in the rat MG and that many of these genes are involved in lipid metabolic pathways.

Metabolic profile of curcumin self-emulsifying drug delivery system in rats determined by ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

Curcumin (Cur) is a natural anticancer pigment, but its poor absorption and extensive metabolism limit its clinical applications. In this study, an ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry method was employed to investigate the metabolic profiles of a Cur self-emulsifying drug delivery system (C-SEDDS) in rat plasma, urine, bile and feces after oral administration at 100 mg/kg. Protein precipitation, solid-phase and ultrasonic extractions were used to prepare different biosamples. A total of 34 metabolites were identified using available reference standards, or tentatively identified based on the mass spectrometric fragmentation patterns and the chromatographic elution order. Nine metabolites of Cur were found for the first time in vivo. Glucuronidation, sulfation, reduction, dehydroxylation, demethylation, demethoxylation and methylation were its possible metabolic reactions. Moreover, the differences were compared in terms of plasma metabolites found in C-SEDDS-treated, Cur suspension-treated and rats treated with a commercial curcuminoid phospholipid complex administered at the same oral dose. Dihydrocurcumin (DHC), DHC glucuronide and methylated DHC were found only in the metabolic profile of C-SEDDS-treated rat plasma, suggesting that different drug delivery systems may cause a change in Cur metabolic pathways. This study provides a sensitive and rapid method for the identification of Cur metabolites in biosamples.

Self-organized thermo-responsive poly (lactic-co-glycolic acid)-graft-pullulan nanoparticles for synergistic thermo-chemotherapy of tumor.

Poly (lactic-co-glycolic acid)-graft-pullulan (PPLGA) based self-organized nanoparticles hold immense potential for synergistic thermo-chemotherapy of tumor. Herein, the biocompatible and biodegradable PPLGA were synthesized by a novel microwave-assisted solution polymerization. The polymers showed thermo-responsive properties, which was attributed to the change of polymer-water hydrogen bonding in controlling the macromolecular contraction, chain collapse as a result of changes in micro-rigidity of core. The curcumin loaded PPLGA nanoparticles (CUR-PPLGA-N), with impressively high drug loading (10.85 ± 0.27 %), exhibited temperature dependence in drug release kinetics. The results of both MTT and antitumor efficiency elucidated that the CUR-PPLGA-N under high temperature facilitated on-demand drug release from the nano-assembly and had a synergistic therapeutic effect for cancer. Thus the developed thermo-responsive PPLGA addressed concerns related to the low drug loading and inefficient drug release at target sites, and might be considered as a powerful nanoplatform for synergistic thermo-chemotherapy of tumor.

Microwave-assisted rapid synthesis, characterization and application of poly (D,L-lactide)-graft-pullulan.

A novel microwave-assisted method was developed to synthetize amphiphilic copolymer poly (d,l-lactide)-graft-pullulan (PL) in a monomode microwave reactor. The effects of microwave power, ratio of catalyst/lactide, ratio of lactide/hydroxyl group of pullulan (lactide/OH-P) and solvent on the synthesis were further investigated. Three samples (designated as PL 8, 9, and 6), characterized by FT-IR and NMR, were applied to form nanoparticles and microparticles investigated by dynamic light scattering, fluorescence spectroscopy and transmission electron microscopy. PL9 and PL6 were used for loading model drug curcumin. The results indicated that microwave-assisted synthesis shortened the copolymerization of PL, with higher yield and lactide conversion, from 24h to 5 min and showed some specific microwave effects compared with conventional oil heating. PL with a relative higher substitution degree gave nanoparticles with smaller sizes and critical aggregation concentrations. The solubility of curcumin was increased to 1.97 mg mL(-1) as the forms of nanoparticles.

Self-microemulsifying drug-delivery system for improved oral bioavailability of 20(S)-25-methoxyl-dammarane-3ß, 12ß, 20-triol: preparation and evaluation.

The objective of this study was to develop a self-microemulsifying drug delivery system (SMEDDS) to enhance the oral bioavailability of the poorly water-soluble compound 20(S)-25-methoxydammarane-3ß;12ß;20-triol (25-OCH3-PPD). Optimized SMEDDS formulations for 25-OCH3-PPD contained Cremophor® EL (50%) as the surfactant, glycerin (20%) as the cosurfactant, and Labrafil® M1944 (30%) as the oil. The SMEDDS were characterized by morphological observation and mean droplet size. The pharmacokinetics and bioavailability of the 25-OCH3-PPD suspension and SMEDDS were evaluated and compared in rats. The plasma concentrations of 25-OCH3-PPD and its main metabolite, 25-OH-PPD, were determined by ultra performance liquid chromatography-tandem mass spectrometry. The relative bioavailability of SMEDDS was dramatically enhanced by an average of 9.8-fold compared with the suspension. Improved solubility and lymphatic transport may contribute to this enhanced bioavailability. Our studies highlight the promise of SMEDDS for the delivery of 25-OCH3-PPD via the oral route.

[Assessment model for heavy metal pollution in sediment based on trapezoidal fuzzy numbers and case study].

Due to the practical shortcomings of the classical deterministic pollution assessment model, the theory of trapezoidal fuzzy numbers was introduced to the environmental assessment system. A fuzzy risk assessment model was built based on the geoaccumulation index and biotoxicity coefficients of heavy metals. Using the fuzzy pollution risk assessment model, the risk of heavy metal pollution was evaluated for the surface sediment of Dongting Lake. The results showed that the pollution risk in a descending order was Hg > Cd > Pb > Cu > Cr > Zn > As, with Hg,Cd and Pb being the priority pollutants in Dongting Lake. Both the intervals of possible values for the geoaccumulation indexes of heavy metals and their credible levels were calculated using this model. Compared with the results of the deterministic assessment model, the fuzzy pollution risk assessment model gave a better characetriztaion of the actual pollution status and spatial distribution difference of the heavy metals in the sediment of the studied region which is more objective and comprehensive.