Life cycle assessment (LCA) has been an important issue in the development of a circular economy. LCA is used to identify environmental impacts and hotspots associated with plywood manufacturing. Based on our results and a literature review of LCA studies involving plywood, a sustainable and environmentally friendly scenario was proposed for the plywood processing industry to improve environmental performance and sustainability. This study covers the life cycle of plywood production from a cradle-to-gate perspective, including raw material preparation and plywood manufacturing and processing to analysis of environment impacts and hotspots. Analysis of abiotic depletion (ADP), acidification effect (AP), primary energy depletion (PED), freshwater eutrophication (EP), global warming potential (GWP), and particulate matter (RI) were selected as major impact categories in this study. All data were obtained from on-site measurements (plywood production) and investigations of the Eco-invent database and CLCD database (upstream data of materials and energy). These data can be ignored when environmental contributions comprise less than 0.001% of environmental impact and auxiliary material quality is less than 0.01% of total raw material consumption. An eco-design strategy with eco-alternatives was proposed: pyrolysis bio-oil can be used to produce green resin to replace traditional phenolic formaldehyde (PF) resin to decrease the impacts of GWP, PED, AP, PM, and especially ADP and EP. A new technology of gluing green wood was used to replace conventional plywood production technology; wood waste could undergo a gasification process to produce resultant gas rather than combusting. Plywood was also compared with other wood-based panels in China to identify additional scenarios to improve environmental sustainability.
In the present study, three pretreatments of sodium hydroxide (NaOH), sulfuric acid (H2SO4), and glycerin were employed with bamboo fibers at two different temperatures of 117 °C and 135 °C, respectively. The chemical composition and structural characterization of the pretreated bamboo fibers were comparatively studied using spectroscopic and wet chemistry methods. Furthermore, the comparative hydrolysis behaviors of pretreated bamboo were studied due to the synergistic interaction between cellulases and xylanase. The NaOH treatment increased the holocellulose contents to 87.4%, and the mean diameter of the cellulose fibers decreased from 50 ± 5 µm (raw fiber bundles) to 5 ± 2 µm. The lignin content and the degree of cellulose polymerization both decreased, while the crystallinity index of cellulose and thermostability increased. The hydrolysis yields of NaOH pretreated bamboo at 135 °C increased from 84.2% to 98.1% after a supplement of 0.5 cellulose to 1 mg protein/g dry xylan. The NaOH pretreatment achieved optimal enzymatic digestibility, particularly at higher temperatures as indicated by the results.
Purpose
Optical coherence tomography angiography (OCTA) is a novel noninvasive imaging tool for retinal and optic nerve head (ONH) perfusion. The study aimed to explore OCTA features in patients with idiopathic macular holes (IMHs) before and after vitrectomy.
Methods
The retrospective case series study included patients with IMHs diagnosed by OCT between June 2019 and June 2021 in our hospital. The best corrected visual acuity (BCVA), superficial and deep foveal avascular zone (FAZ) area, blood flow density within 300µm width of FAZ (FD300) and the state of external limiting membrane (ELM) were examined by OCTA.
Results
Totally 26 patients (9 men and 17 women) aged 65.08 ± 5.09 years were included, with an average disease course of 154.15 ± 206.26 days. Visual acuity showed no improvement at 1 month but was improved at 6 months (P < 0.05). FAZ, superficial FAZ, deep FAZ, and FD300 showed a decreasing tendency at 1 month, indicating an amelioration following surgery. Though data within 6 months showed decreased efficacy over time, there were significant improvements compared with preoperative parameters (P < 0.05). The 1-month FAZ in the deep layer (P < 0.01) and FD300 (P < 0.01) were significantly increased in the ELM (+) group. The differences were more pronounced at 6 months (FAZ in the deep layer: P < 0.01; FD300: P < 0.01).
Conclusion
OCTA may dynamically monitor the neurovascular repair process of IMH and predict the prognosis of visual function after IMH operation.
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