Clinical application of a shape-preserving rapid corneal donor dehydrater.

AIM: To describe the design and clinical application of a corneal donor dehydrator which can quickly dehydrate corneas and keep its original shape. METHODS: The corneal donor material is placed on stainless steel beads with different diameters in the dehydrating box to make the cornea the same shape as the steel ball. Then, the cornea is placed inside the dehydrater for rapid dehydrating using the internal cleaning and ventilation system. Totally 83 eyes underwent deep anterior lamellar keratoplasty (DALK) using corneal donor tissue preserved with corneal dehydrater, and 60 patients (60 eyes) received DALK by the same surgeon using corneal donor tissue preserved with glycerol were included in the control group. The best corrected visual acuity (BCVA), the thickness and transparency of the corneal buttons were recorded. RESULTS: After the completion of dehydrating, all the donor corneas maintained a normal shape without any shrinkage or distortion, and the average intraoperative rehydration time was 43.3±12.1s during operation. The mean BCVA of the dehydrater group was 0.30±0.18 at 1wk and 0.32±0.16 at 1mo, which were statistically better than that of the control group (P<0.001). The score of corneal buttons transparency were lower than that of the control group with statistical difference (P<0.001). The thickness of corneal buttons at 1wk and at 1mo in the dehydrater group was significantly better than that of the control group respectively (P<0.001). One week after operation, no corneal button turbidity or edema was observed in both groups. CONCLUSION: The dehydrater can quickly dehydrate the corneal material in a clean and airtight environment and maintain the original shape of the corneal donor during the dehydrating process. This dehydrater is recommended for long-term high-quality preservation in areas where corneal materials cannot be used within a reasonable time period.

Increased cGAS/STING signaling components in patients with Mooren's ulcer.

AIM: To explore the expression of cGAS/STING signaling components in Mooren's ulcer (MU). METHODS: Samples were obtained from ten MU patients, and eight residual corneal-scleral rings of healthy donor corneas for controls. Human corneal epithelial cells (HCECs) were used to evaluate the effect of cGAS/STING signaling pathway. Immunohistochemistry (IHC) and Western blot were used to examine the expression of cGAS, STING, and phosphorylated interferon regulatory factor 3 (p-IRF3) in MU tissues. The expression of interferon-ß (IFN-ß) and interferon-stimulated genes (ISGs) was quantified by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). RESULTS: The protein levels of cGAS and STING in MU samples were significantly elevated when compared with the healthy controls by Western blot and IHC. After stimulation with cGAMP, real-time PCR and ELISA showed a dramatic increase of IFN-ß and ISGs (containing CXCL10, IFIT1, and IL-6) in HCECs. Moreover, HCECs treated with cGAMP was characterized by increased phosphorylation and more nuclear translocation of IRF3. Meanwhile, increased p-IRF3 was observed in MU samples via IHC and Western blot. CONCLUSION: The pronounced expression of cGAS/STING signaling components in the patients with MU and probably contribute to the onset and development of MU.

Recent Progress on Metal-Organic Framework and Its Derivatives as Novel Fire Retardants to Polymeric Materials.

High flammability of polymers has become a major issue which has restricted its applications. Recently, highly crystalline materials and metal-organic frameworks (MOFs), which consisted of metal ions and organic linkers, have been intensively employed as novel fire retardants (FRs) for a variety of polymers (MOF/polymer). The MOFs possessed abundant transition metal species, fire-retardant elements and potential carbon source accompanied with the facile tuning of the structure and property, making MOF, its derivatives and MOF hybrids promising for fire retardancy research. The recent progress and strategies to prepare MOF-based FRs are emphasized and summarized. The fire retardancy mechanisms of MOF/polymer composites are explained, which may guide the future design for efficient MOF-based FRs. Finally, the challenges and prospects related to different MOF-based FRs are also discussed and aim to provide a fast and holistic overview, which is beneficial for researchers to quickly get up to speed with the latest development in this field.

Simultaneous Improvement of Mechanical and Fire-Safety Properties of Polymer Composites with Phosphonate-Loaded MOF Additives.

Flame-retardant (FR) additives are commonly used to improve the fire safety of synthetic polymers, which are widely employed in manufactured consumer goods. Incorporation of an FR in a polymer typically leads to deterioration of its mechanical properties. It also manifests itself in non-negligible volatile organic compound (VOC) release, which in turn increases environmental risks carried by both the application and disposal of the corresponding consumer goods. Herein, we present a hierarchical strategy for the design of composite materials, which ensures simultaneous improvement of both mechanical and fire-safety properties of polymers while limiting the VOC release. Our strategy employs porous metal-organic framework (MOF) particles to provide a multifunctional interface between the FR molecules and the polymer. Specifically, we demonstrate that the particles of environmentally friendly HKUST-1 MOF can be infused by a modern FR-dimethyl methylphosphonate (DMMP)-and then embedded into widely used unsaturated polyesters. The DMMP-HKUST-1 additive endows the resulting composite material with improved processability, flame retardancy, and mechanical properties. Single-crystal X-ray diffraction, thermogravimetric analysis, and computational modeling of the additive suggest the complete pore filling of HKUST-1 with DMMP molecules being bound to the open metal sites of the MOF.

Flame Retardant Polypropylene Composites with Low Densities.

Polypropylene (PP) is currently widely used in areas requiring lightweight materials because of its low density. Due to the intrinsic flammability, the application of PP is restricted in many conditions. Aluminum trihydroxide (ATH) is reported as a practical flame retardant for PP, but the addition of ATH often diminishes the lightweight advantage of PP. Therefore, in this work, glass bubbles (GB) and octacedylamine-modified zirconium phosphate (mZrP) are introduced into the PP/ATH composite in order to lower the material density and simultaneously maintain/enhance the flame retardancy. A series of PP composites have been prepared to explore the formulation which can endow the composite with balanced flame retardancy, good mechanical properties, and low density. The morphology, thermal stability, flame retardancy, and mechanical properties of the composites were characterized. The results indicated the addition of GB could reduce the density, but decreased the flame retardancy of PP composites at the same time. To overcome this defect, ATH and mZrP with synergetic effect of flame retardancy were added into the composite. The dosage of each additive was optimized for achieving a balance of flame retardancy, good mechanical properties, and density. With 47 wt % ATH, 10 wt % GB, and 3 wt % mZrP, the peak heat release rate (pHRR) and total smoke production (TSP) of the composite PP-4 were reduced by 91% and 78%, respectively. At the same time, increased impact strength was achieved compared with neat PP and the composite with ATH only. Maintaining the flame retardancy and mechanical properties, the density of composite PP-4 (1.27 g·cm-3) is lower than that with ATH only (PP-1, 1.46 g·cm-3). Through this research, we hope to provide an efficient approach to designing flame retardant polypropylene (PP) composites with low density.

Apoptotic mechanisms in rabbits with blast-induced acute lung injury 1.

PURPOSE: To investigate the apoptotic mechanisms in rabbits with blast-induced acute lung injury (ALI). METHODS: A total of 40 rabbits were randomly divided into a blank control group (A, n=10) and an experimental group (EXP, n=30). Explosion-induced chest-ALI models were prepared and sampled at different time points (4, 12, and 24h after modeling, T1-T3) to test the lung dry weight/wet weight ratio (W/D) and arterial oxygen pressure (PaO2), apoptosis of lung tissue by the TUNEL assay, and Caspase-3, Bax, and Bcl-2 levels by immunohistochemical analysis. Furthermore, lung tissue was sampled to observe pathological morphology by microscopy. RESULTS: Under a light microscope, Group EXP exhibited obvious edema in the pulmonary interstitial substance and alveoli, a large number of red blood cells, inflammatory cells, and serous exudation in the alveolar cavity, as well as thickening of the pulmonary interstitial fluid. Compared to Group A, the W/D ratio was significantly increased in Group EXP (P<0.01), while PaO2 was significantly reduced (P<0.01). The apoptosis index was significantly increased (P<0.01), and caspase-3 and Bax/Bcl-2 levels were increased (P<0.01). CONCLUSION: Apoptosis plays an important role in the occurrence and development of acute lung injury in rabbits by participating in lung injury and promoting the progression of ALI.

Apoptotic mechanisms in rabbits with blast-induced acute lung injury

Abstract Purpose: To investigate the apoptotic mechanisms in rabbits with blast-induced acute lung injury (ALI). Methods: A total of 40 rabbits were randomly divided into a blank control group (A, n=10) and an experimental group (EXP, n=30). Explosion-induced chest-ALI models were prepared and sampled at different time points (4, 12, and 24h after modeling, T1-T3) to test the lung dry weight/wet weight ratio (W/D) and arterial oxygen pressure (PaO2), apoptosis of lung tissue by the TUNEL assay, and Caspase-3, Bax, and Bcl-2 levels by immunohistochemical analysis. Furthermore, lung tissue was sampled to observe pathological morphology by microscopy. Results: Under a light microscope, Group EXP exhibited obvious edema in the pulmonary interstitial substance and alveoli, a large number of red blood cells, inflammatory cells, and serous exudation in the alveolar cavity, as well as thickening of the pulmonary interstitial fluid. Compared to Group A, the W/D ratio was significantly increased in Group EXP (P<0.01), while PaO2 was significantly reduced (P<0.01). The apoptosis index was significantly increased (P<0.01), and caspase-3 and Bax/Bcl-2 levels were increased (P<0.01). Conclusion: Apoptosis plays an important role in the occurrence and development of acute lung injury in rabbits by participating in lung injury and promoting the progression of ALI.

Investigation of synergistic antimicrobial effects of the drug combinations of meropenem and 1,2-benzisoselenazol-3(2H)-one derivatives on carbapenem-resistant Enterobacteriaceae producing NDM-1.

The worldwide prevalence of NDM-1-producing bacteria has drastically undermined the clinical efficacy of the last line antibiotic of carbapenems, prompting a need to devise effective strategy to preserve their clinical value. Our previous studies have shown that ebselen can restore the efficacy of meropenem against a laboratory strain that produces NDM-1. Here we report the construction of a focused compound library of 1,2-benzisoselenazol-3(2H)-one derivatives which comprise a total of forty-six candidate compounds. The structure-activity relationship of these compounds and their potential to serve as an adjuvant to enhance the antimicrobial efficacy of meropenem against a collection of clinical NDM-1-producing carbapenem-resistant Enterobacteriaceae isolates was examined. Drug combination assays indicated that these derivatives exhibited synergistic antimicrobial activity when used along with meropenem, effectively restoring the activity of carbapenems against the resistant strains tested in a Galleria mellonella larvae in vivo infection model. The mode of inhibition of one compound, namely 11_a38, which was depicted when tested on the purified NDM-1 enzyme, indicated that it could covalently bind to the enzyme and displaced one zinc ion from the active site. Overall, this study provides a novel 1,2-benzisoselenazol-3(2H)-one scaffold that exhibits strong synergistic antimicrobial activity with carbapenems, and low cytotoxicity. The prospect of application of such compounds as carbapenem adjuvants warrants further evaluation.

Modified ulcer debridement in the treatment of the superficial fungal infection of the cornea.

AIM: To evaluate the efficacy of modified corneal ulcer debridement in superficial fungal keratitis unresponsive to medications. METHODS: A total of 209 patients (209 eyes) with fungal keratitis, involving no more than 50% of the stromal depth and not responding to antifungal agents for 2wk, were recruited in this retrospective, noncomparative study. The patients were treated with modified corneal ulcer debridement. All visible corneal infiltrates were removed under an operating microscope to obtain a clean stromal bed and smooth incised edges. Antifungal drugs were used immediately after surgery. Healing time of the ulcers was recorded. Fungal recurrence, visual acuity, corneal thickness and risk factors for treatment failure were monitored. RESULTS: The follow-up was 13.6±5.8mo. The corneal ulcers healed in 195 of 209 eyes (93.3%), with a mean healing time of 8.4±6.8d. The other 14 eyes were further treated by penetrating keratoplasty (PK) (1 eye), anterior lamellar keratoplasty (LK) (7 eyes), conjunctival flap covering (4 eyes) or amniotic membrane transplantation (2 eyes). The best corrected visual acuity (BCVA) was ≥20/70 in 80.3% of the eyes, ≥20/40 in 56.9% of the eyes, and ≥20/25 in 27.3% of the eyes. The corneas at the lesions became thinner, but all in the safe range. No fungal recurrence or corneal ectasis developed during the follow-up. The risk of treatment failure was higher in patients with preoperative hypopyon (P=0.036) and ever using steroid (P=0.025). CONCLUSION: Modified surgical debridement is a simple and effective method for the treatment of superficial fungal infection of the cornea, with improved visual acuity and no recurrence. Such an intervention in time can rapidly control fungal infection and largely shorten corneal ulcer healing time.

Variation in contents of main active components and antioxidant activity in leaves of different pigeon pea cultivars during growth.

Pigeon pea is an important and multiuse grain legume crop, and its leaves are a very valuable natural resource. To obtain a high-quality biological resource, it is necessary to choose the excellent cultivar and determine the appropriate harvest time. In this study, the variation in contents of main active components and antioxidant activity in leaves of six pigeon pea cultivars during growth were investigated. The level of each individual active component significantly varied during growth, but with a different pattern, and this variation was different among cultivars. Flavonoid glycosides orientin, vitexin, and apigenin-6,8-di-C-α-L-arabinopyranoside showed two peak values at mid-late and final stages of growth in most cases. Pinostrobin chalcone, longistyline C, and cajaninstilbene acid showed remarkablely higher values at the mid-late stage of growth than at other stages. Pinostrobin had an extremely different variation pattern compared to other active components. Its content was the highest at the earlier stage of growth. Principal component analysis (PCA) revealed that vitexin and apigenin-6,8-di-C-α-L-arabinopyranoside were mainly responsible for distinguishing cultivars analyzed. In a comprehensive consideration, the leaves should preferentially be harvested at the 135th day after sowing when the level of active components and antioxidant activity reached higher values. Cultivars ICP 13092, ICPL 87091, and ICPL 96053 were considered to be excellent cultivars with high antioxidant activity. Our findings can provide valuable information for producing a high-quality pigeon pea resource.

Phosphorescence doping in a flexible ultramicroporous framework for high and tunable oxygen sensing efficiency.

Doping very small amounts of Ru(II) into a flexible, ultramicroporous, fluorescent Zn(II) coordination polymer produced phosphorescent materials with very high and tunable oxygen quenching efficiency; and a simple color-changing ratiometric oxygen sensor has been constructed.

[Protective effect of Qihuang Mingmu capsule on retina of diabetic mice and its impact on VEGF expression].

OBJECTIVE: To investigate the protective effect of Qihuang Mingmu capsule (QHMM) on retina of diabetic mice and its impact on VEGF expression. METHOD: Forty KK/Upj-Ay mice were randomly divided into the model group and high, middle and low dose QHMM (8.32, 4.16, 2.08 g x kg(-1)) groups. Additional 10 C57BL/6 mice were selected as the control group. Mice were orally administered for three months. Their general appearance, fasting blood-glucose (FBG) and glycosylated hemoglobin (HbA1c) were observed. Pathological changes of retina were observed by light microscope and electron microscope. The expressions of vascular endothelial growth factor (VEGF), growth factor receptors-1 (Flt-1) and growth factor receptors-2 (Flk-1) were examined by Real-time PCR (qPCR) and Western blot. RESULT: QHMM could ameliorate the symptoms of diabetic mice to varying degrees, decrease FBG and HbA1c, alleviate pathological lesions of retina and decrease the expressions of VEGF, Flt-1, Flk-1 mRNA and protein. CONCLUSION: QHMM has the protective effect on diabetic retinopathy of mice by inhibiting the expressions of VEGF, Flt-1 and Flk-1 and intervening VEGF-VEGFR signal transduction pathway.

Interweaving isomerism and isomerization of molecular chains.

The silver(I) isopropylimidazolate crystallizes as three genuine interweaving supramolecular isomers, including a sinusoidal chain, a rare quintuple helix, and an unprecedented chicken-wire pattern. Heating transforms the chicken-wire into the quintuple helix through an interesting mechanism.