Teachers' and students' perceptions of a sense of community in blended education.

Universities have renewed interest in blended learning in preparation for post-COVID education. However, unsatisfactory social interactions hinder the quality of blended learning, despite its potential for flexible and personalized learning. In this situation, a sense of community would provide essential academic and social benefits. To develop a sense of community among students, we need to further understand students' and teachers' perceptions concerning this subject by exploring their experiences in blended learning. Therefore, we investigated this for three blended courses using a qualitative case study approach. We conducted: (1) classroom observation; (2) document analysis of course content, assignments, and assessments; and (3) individual interviews with teachers (n = 3) and group interviews with students (n = 18). The results showed the main factors that appeared to contribute to sense of community: group learning activities within courses, non-academic and extracurricular activities across courses, and the campus as a physical place integrating academic and social life after COVID. Further, we identified two obstacles: students valued group learning but struggled to manage group dynamics, and despite teachers' efforts to encourage learning autonomy, students viewed teachers as the ultimate authority in the learning process, which strained the student-teacher relationship. Additionally, this study revealed the limitations that digital tools have for promoting sense of community, as students questioned whether these tools have added value for supporting intricate and in-depth conversations. Finally, based on these findings, we provided practical recommendations for the future development of sense of community in blended learning.

Chitosan-poloxamer-based thermosensitive hydrogels containing zinc gluconate/recombinant human epidermal growth factor benefit for antibacterial and wound healing.

Chitosan/poloxamer-based thermosensitive hydrogels containing zinc gluconate/recombinant human epidermal growth factor (ZnG/rhEGF@Chit/Polo) were developed as a convenient, safe and effective dressing for skin wound treatment. Their fabrication procedure and characterization were reported, and their morphology was examined by a scanning electron microscope. Antibacterial and biofilms activities were evaluated by in vitro tests to reveal the inhibitory effects and scavenging activity on the biofilms of Staphylococcus aureus and Pseudomonas aeruginosa. ZnG/rhEGF@Chit/Polo was also investigated as a potential therapeutic agent for wound healing therapy. In vivo wound healing studies on rats for 21 days proves that ZnG/rhEGF@Chit/Polo supplements the requisite Zn2+ and rhEGF for wound healing to promote the vascular remodeling and collagen deposition, facilitate fibrogenesis, and reduce the level of interleukin 6 for wound basement repair, and thus is a good wound therapy.

Evaluation of the synergetic effect of Yupingfeng san and Flos Sophorae Immaturus based on free radical scavenging capacity.

OBJECTIVE: This study aimed to determine the optimal extraction process and examine whether the combination of Flos Sophorae Immaturus (FSI) and Yupingfeng san (YPS) has a synergistic effect on free radical scavenging capacity. DESIGN AND METHODS: The time of immersion and extraction and the ratios (material/solvent) of the combination of YPS and FSI were optimized on the basis of polysaccharide and flavonoid yields via orthogonal design. The optimal result was used in the 1,1-diphenyl-1-picrylhydrazyl (DPPH) assay and animal experiments to test the antioxidant activity, which is reflected by superoxide dismutase, malondialdehyde, glutathione peroxidase, and total antioxidant capacity serum levels. The optimal extraction process was determined using various ingredients to obtain complex extracts with high active ingredient content and antioxidant activity. DPPH assay results showed that the optimized ingredients have antioxidant effects, and the combination had better antioxidation function than YPS in vitro. The combination also showed synergistic antioxidant activity compared with YPS in vivo. CONCLUSIONS: The combination of YPS and FSI had a synergistic antioxidant effect in vitro. The optimized extracts had antioxidant effects in vivo. These results indicated that YPS could be used with FSI to improve its antioxidant capacity in the body on the basis of free radical scavenging capacity.

Synthesis, Characterization, and Pharmacodynamics Study of Enrofloxacin Mesylate.

INTRODUCTION: Enrofloxacin is used in the treatment of a wide variety of bacterial infections in mammals. However, its poor solubility limits the clinical use. METHODS: In order to improve the solubility of enrofloxacin, the enrofloxacin mesylate (EM) were obtained by a chemical synthesis method. The characterization of EM was carried out using ultraviolet scan (UV), synchronous thermal analysis (SDT), fourier transform infrared spectrometer (FTIR) and mass spectrometry (MS), nuclear magnetic resonance (NMR) and X-ray powder diffraction analysis (XRPD). Acute toxicity of EM in Kunming mice was studied. Besides, pharmacokinetic studies were performed in New Zealand rabbits at a single oral dose of 10 mg/kg, and the antibacterial activity of EM was also evaluated. RESULTS: EM was successfully synthesized and purified. The stoichiometric ratio of mesylate to enrofloxacin was 1:1 and the aqueous solubility of EM was 483.01±4.06 mg/mL, the solubility of EM was about 2000 times higher than enrofloxacin. The oral lethal dose (LD50) of EM was 1168.364 mg/kg, and the pharmacokinetics indicated that the oral relative bioavailability of EM was about 1.79 times and 1.48 times higher than that of enrofloxacin and enrofloxacin hydrochloride, respectively. In addition, the in vitro antibacterial activity of EM was not significantly changed compared with enrofloxacin and enrofloxacin hydrochloride. CONCLUSION: EM has higher solubility, low toxicity for oral use, and increases the oral bioavailability in rabbit. This study may be of benefit for the development of new enrofloxacin drugs.

Isobologram Analysis: A Comprehensive Review of Methodology and Current Research.

Drug combination is a common method for clinical disease treatment. Whether the combination of drugs is reasonable often affects the result of the disease treatment. Many methods have been used to evaluate interaction between drugs to date. Isobologram analysis has been mathematically proven and widely used to evaluate drug interactions. In this paper, the principle of isobologram analysis and its application in drug interaction evaluation are summarized. The applications of the similar cotoxicity coefficient and fractional inhibitory concentration index in the evaluation of drug interaction are also reviewed. This work is expected to evaluate the effect of formulations scientifically and provide scientific judgment standards for the development of formulations and clinical drug compatibility.

[Analysis of Influence of Pushroom Erros on The Data Reconstruction of Computational Imaging Spectrometer].

The technology of computational spectral imaging changes the traditional imaging modalities by introducing a coded aperture in the optical path to achieve transformation of the targets spectral imformation, then we can get the spectral data cube by reverse transform. This paper introduces the principle of a push-broom imaging coded aperture computational spectral imager. In practical applications, the matching error between the push speed and the frame rate can affect the accuracy of the spectral data reconstruction. The error terms are deduced based on the model of pushroom, the influences of matching errors to the spectral data reconstruction are anlyzed. And the second spectra derivative and strehl ratio are introduced as the evaluation parameters to, respectively, evaluate the reconstructed spectral and spatial image in the data simulation analysis. It showed that, when the accumulated error of a complete set of data is more than one pixel, the shading dramaticly area's reconstructed results are relatively poor, but the relatively homogeneous regions are affected small; when cumulative error does not exceed half pixel, strehlretio of each channel were above 0.9, and the lower of the spectral energy, the channels strehl ratio smaller, so the more the ranks of the coding template, the higher the platform's stability required.

[The Snapshot Imaging Spectrometer with Image Replication Based on Wallaston Prism].

In this paper, a kind of snapshot imaging spectrometer is designed by using image replication based on Wollaston prism. The system includes telephoto lens, collimator lens, Wollaston prism, the imaging lens and compensation filters. With this optical system, we can obtain two-dimensional information at different wavelengths of the same target through one time exposure. When Light beam is passing Wollaston prisms, in order to make sure that the different wavelengths will not overlap, the Wollaston prism needs to be designed with relatively large beam splitting angle. Then the incidence angle of the imaging lens is relatively large. It will increase the difficulty of the imaging lens design. We design, analyze the principle and the characteristics of the snapshot imaging spectrometer using image replication based on Wollaston prism, and design a complete set of imaging spectrometer system. The structure is complex; the aperture of the optical system must be well matched. In order to make sure that we can obtain good image quality through the single lens, but also the whole system, we design the telephoto lens which is imaging telecentric structure, the collimator lens which is objective telecentric structure. We use the multiple structures in ZEMAX to optimize the 16 spectral bands. At 56 lp·mm(-1), the MTF is close to the diffraction limit, the RMS of the SPT is in the Airy disk, proving good image quality.

[Effect evaluation of optical magnification errors for coded aperture spectrometer].

In the present paper, we simulated the system optical magnification error's influence on the quality of reconstructed image, analyzed the variant of the coded aperture with different optical magnification, then proposed an accurate curve of image quality and optical magnification in 128 x 128 code template, which provide important references for the design and development of push-broom coded aperture spectrometer.

[Interference hyperspectral data compression based on spectral classification and local DPCM].

In order to get a high compression ratio, according to the spatial dimension correlation and the interference spectral dimension correlation of interference hyperspectral image data, the present article provides a new compression algorithm that combines spectral classification with local DPCM. This algorithm requires spectral classification for the whole interference hyperspectral image to get a classification number matrix corresponding to the two-dimensional space and a spectral classification library corresponding to the interference spectra first, then local DPCM is performed for the spectral classification library to get a further compression. As the first step of the compression, the spectral classification is very important to the compression effect. This article analyzes the differences of compression effect with different standard and different accuracy of classification, the relative Euclidean distance standard is better than the angle standard and the interference RQE standard. Finally, this article chooses an appropriate standard of compression and achieves the combined compression algorithm with programming. Compared to JPEG2000, the compression effect of combined compression algorithm is better.

Characteristics of carotid artery disease (CAD) and presenting cerebrovascular symptoms in an aged group.

OBJECTIVES: In the present study we measured carotid plaque morphology and plaque area by Duplex Doppler ultrasonography (US), as well as angiographic extent of carotid artery stenosis referred for carotid arteriography (DSA) in patients with two or more atherosclerotic risk factors, to assess the relation between features of carotid artery disease (CAD) and presenting cerebrovascular symptoms directly in the elderly. METHODS: Some 74 symptomatic (transient ischaemic attack (TIA) 17, amaurosis fugax 34, transient stroke 4, established stroke 10, progressive stroke 9) and 52 asymptomatic patients were studied with US and DSA. All patients was of 60-85 years old. Carotid plaque morphology (echolucent, echogenic or complex) and plaque area were assessed with US, and luminal stenosis was measured with DSA. Spearman correlation analysis was performed to identify the association between characteristics of CAD and presenting symptoms. RESULTS: Symptomatic patients with echolucent and complex plaque were common than that with echogenic plaque (P < 0.05 and P < 0.01 respectively). With advanced plaque area and degree of carotid luminal stenosis, the incidence of general symptom had increased significantly, but percentage of patients with regular treatment had decreased gradually. Spearman correlation analysis confirmed that presenting symptoms was in direct correlation with Carotid Plaque Area (P < 0.05) and carotid luminal stenosis (P < 0.05), but was in negative correlation with regular treatment of cardiovascular risk (P < 0.01). Analysis showed that features of CAD did not distinguish between types of symptomatic patients. CONCLUSIONS: There was an association between features of CAD and the presence of symptoms but not their type in the elderly. Identifying high risk elderly patients of CAD and giving regular treatment earlier might stabilize the plaque, reduce the plaque area and the progression in luminal stenosis, then decline or prevent the incidence of presenting cerebrovascular symptoms.