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Introduction: It is important to identify the relationship between the COVID-19 vaccination status and the prognosis of this disease in hospitalized patients to gain a more accurate picture of their status and the effect of vaccination, as well as take necessary measures to improve their medical care. Thus, the present study was conducted to investigate the relationship between the vaccination status of hospitalized COVID-19 patients and the disease severity index in terms of clinical, imaging, and laboratory criteria., Methods: This research is a descriptive-analytical cross-sectional study. the study population consisted of patients with a positive RT-PCR test for coronavirus, admitted to COVID-19 departments of teaching hospitals in Yazd, Iran, during two months in the sixth peak of COVID-19. The patients' data comprised demographic information (age, sex, and underlying disease), clinical information (length of hospital stay, length of ICU stay, and vaccination status), disease outcome (mortality and intubation), laboratory information (ESR, CRP, and NLR), and imaging information (lung involvement percentage), and finally, the relationship between patients' vaccination status and disease severity indices were analyzed with the chi-square test, independent t-test, and logistic regression analysis at a 95% confidence interval (CI)., Findings: According to research findings, the duration of hospitalization was 5.25 ± 2.34 and 6.11 ± 3.88 days in groups of patients with complete and incomplete vaccination, respectively (P = 0.003). The lengths of ICU stay were 6 ± 4.63 and 5.23 ± 3.73 days in both groups of patients admitted to the ICU (P = 0.395). Furthermore, there were significant relationships between the ICU admission rates, endotracheal intubation, mortality rate, the lung involvement score in the chest CT scan, and the NLR with the vaccination status.Multivariate regression analysis indicated that DM, IHD, NLR, CT scan score and vaccination status were related to patients' in-hospital mortality., Conclusion: Complete vaccination of COVID-19 led to a milder disease in terms of clinical, imaging, and laboratory criteria of patients and decreased the possibility of hospitalization in ICUs, intubation, and mortality in patients., (© 2024. The Author(s).)

Nanocomposite hydrogels based on tyramine conjugated gum tragacanth, poly (vinyl alcohol) (PVA), and halloysite nanotubes (HNTs) were prepared by electron beam irradiation and characterized. The FTIR, 1 H NMR, and TGA results confirmed the chemical incorporation of HNTs into gum tragacanth. Gel content and swelling of hydrogels decreased with HNTs loading up to 20 % wt. The mechanical strength of hydrogels increased by increasing HNTs content up to 10 % with 371 kPa fracture stress at 0.95 fracture strain, compared to 312 kPa stress at 0.79 strain for gum tragacanth/PVA hydrogel. Hydrogel's biocompatibility and osteogenic activity were tested by seeding rabbit bone marrow mesenchymal stem cells. The cell viability was >85 % after 7 days of culture. In vitro secretion of ALP and calcium deposition on hydrogels in alizarin red assay after 21 days of culture indicated hydrogel potential for bone tissue engineering., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ebrahim Vasheghani-Farahani reports financial support was provided by Iran National Science Foundation (INSF) with grant number 96004459., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Purpose: To evaluate the effect of intravitreal recombinant tissue plasminogen activator (tPA) on diabetic tractional fibrovascular membranes (FVM) using proposed optical coherence tomography (OCT) criteria., Methods: This prospective, interventional case series enrolled eyes with tractional retinal detachment who were candidates for pars plana vitrectomy. OCT images were obtained to evaluate the border of the attached-detached retina and overlying FVP at baseline and 1 week post-intravitreal tPA injection using the follow-up scan acquisition protocol. Two independent graders assessed retinal detachment (RD) height, FVM height, and retinal thickness at the site of membrane attachment., Results: Thirteen eyes from 13 individuals were included. Assessment of RD height, FVM height, and retinal thickness at membrane attachment point were feasible at both visits in 10/13 (77%), 10/13 (77%), and 8/13 (62%) of eyes, respectively. There was excellent agreement between the two graders for all measurements (all ICC > 0.94). Release of the retina-membrane attachment point was not observed in any eyes. No statistically significant change was found in any of the measured parameters., Conclusions: Excellent agreement was achieved between the graders for quantitative assessment of diabetic FVM using our proposed OCT criteria. We did not observe a significant change in the FVM measurements, 1-week after intravitreal tPA injection.

Low mechanical strength and untargeted osteoinduction of chitosan hydrogel limit its application for bone regeneration. This study aimed to develop an injectable chitosan hydrogel with enhanced mechanical strength and improved osteoinductivity for bone tissue engineering. For this purpose, chitosan-modified halloysite nanotubes (mHNTs) were synthesized first. Then, icariin as a bone inducer was loaded into mHNTs (IC@mHNTs), resulting in a sustained drug release system. Further, nanocomposite chitosan/mHNTs hydrogels were prepared by the sol-gel transition, leading to decreased gelation time and temperature and enhanced mechanical strength of the resulting scaffolds. The mesenchymal stem cells were encapsulated into the hydrogels, and in vitro viability assays showed scaffold biocompatibility. Moreover, embedded mHNTs or IC@mHNTs in the scaffold resulted in enhanced proliferation and bone differentiation of encapsulated cells. It was collectively demonstrated that the injectable in situ forming nanocomposite chitosan hydrogel loaded with IC@mHNTs is a promising candidate for bone regeneration., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In the present study, preparation of blend hydrogels of tyramine conjugated gum tragacanth and poly (vinyl alcohol) was carried out by electron beam irradiation, and modification of hydrogel properties with poly (vinyl alcohol) was demonstrated. Gel content, swelling behavior, pore size and mechanical and rheological properties of hydrogels prepared at 14, 28 and 56 kilogray (kGy) with different ratios of polymers were investigated. Gel content increased from 67 ± 2% for pure tyramine conjugated gum tragacanth hydrogel to >92% for blend hydrogels. However, the corresponding equilibrium swelling degree decreased from 35.21 ± 1.51 to 9.14 ± 1.66 due to the higher crosslink density of blend hydrogel. The mechanical strength of the hydrogels with interconnected pores increased significantly in the presence of poly (vinyl alcohol) and increasing irradiation dose up to 28 kGy with a twenty-fold enhancement of stress fracture and excellent elastic recovery in cyclic compression analysis. The equilibrium swelling degree of blend hydrogel containing 3% w/v tyramine conjugated gum tragacanth and 2% w/v poly (vinyl alcohol) prepared at 28 kGy was 16.59 ± 0.81. The biocompatibility of hydrogels was tested in the presence of rabbit bone marrow mesenchymal stem cells. The viability of cells exposed to hydrogel extract was >92% after 7 days of culture and indicated hydrogel biocompatibility with potential biomedical applications., Competing Interests: Declaration of competing interest The authors have no affiliation with any organization with a direct or indirect financial interest in the subject matter discussed in the manuscript., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In the present study, injectable hydrogels based on gum tragacanth-tyramine conjugate were prepared by enzymatic oxidation of tyramine radicals in the presence of hydrogen peroxide. Then, in vitro release of bovine serum albumin and insulin as model protein drugs from this polymeric network was investigated. Also, to improve the properties of this hydrogel, a blended hydrogel composed of tyramine-conjugated gelatin and tyramine-conjugated tragacanth was prepared. Experimental results showed that the gelation time ranged from 3 to 28 s depending on the polymer and enzyme concentrations. Results of morphological investigation of hydrogels indicated that the average pore size of hydrogels varied from 120 to 160 µm. Swelling degree of hydrogels and the rate of drug release decreased by increasing of hydrogen peroxide and polymer concentrations. The release profile of drug from hydrogels followed Higuchi and Fickian diffusion mechanism. Finally, it was shown that the swelling characteristics and drug release behavior of this polymeric network could be improved by blending it with tyramine-conjugated gelatin., (© The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)