An engineered lamellar bone mimicking full-scale hierarchical architecture for bone regeneration.

Lamellar bone, compactly and ingeniously organized in the hierarchical pattern with 6 ordered scales, is the structural motif of mature bone. Each hierarchical scale exerts an essential role in determining physiological behavior and osteogenic bioactivity of bone. Engineering lamellar bone with full-scale hierarchy remains a longstanding challenge. Herein, using bioskiving and mineralization, we attempt to engineer compact constructs resembling full-scale hierarchy of lamellar bone. Through systematically investigating the effect of mineralization on physicochemical properties and bioactivities of multi-sheeted collagen matrix fabricated by bioskiving, the hierarchical mimicry and hierarchy-property relationship are elucidated. With prolongation of mineralization, hierarchical mimicry and osteogenic bioactivity of constructs are performed in a bidirectional manner, i.e. first rising and then descending, which is supposed to be related with transformation of mineralization mechanism from nonclassical to classical crystallization. Construct mineralized 9 days can accurately mimic each hierarchical scale and efficiently promote osteogenesis. Bioinformatic analysis further reveals that this construct potently activates integrin α5-PI3K/AKT signaling pathway through mechanical and biophysical cues, and thereby repairing critical-sized bone defect. The present study provides a bioinspired strategy for completely resembling complex hierarchy of compact mineralized tissue, and offers a critical research model for in-depth studying the structure-function relationship of bone.

Prevalence rates of cataract and cataract surgery in elderly Chinese people living in suburban Shanghai: the Pujiang Cataract Cohort Study.

PURPOSE: To estimate the prevalence rates of cataract and cataract surgery in suburban Shanghai, China. METHODS: This population-based, cross-sectional study was carried out in Pujiang Town, Shanghai, China, using a random cluster sampling strategy. A total of 5846 participants (11,657 eyes) aged ≥65 years were enrolled. Detailed eye examinations included presenting visual acuity (VA), best-corrected VA, non-contact tonometry, measurement of ocular parameters using IOLMaster 700, slit-lamp assessment of lens opacities using the Lens Opacities Classification System III and dilated fundus evaluation. RESULTS: Cataract was present in 57.0% of participants (53.8% of eyes). Cortical, nuclear and posterior subcapsular cataract (PSC) were found in 41.3%, 41.0% and 12.6% of participants. Among participants with any cataract, VA was <20/40 in 32.5%. According to Global Burden of Disease Study visual impairment (VI) criteria, 52.5% of participants with PSC had VI, 4.9% were considered blind (VA <20/400) and 31.9% had moderate VI (VA ≥20/400 to <20/63). This rate was significantly greater than that in participants with cortical (32.0%) or nuclear (38.0%) cataract (P<0.05). Cataract surgery was performed in 8.1% of eyes (men, 3.1%; women, 5.0%) or 10.9% of participants (men, 4.2%; women, 6.7%). CONCLUSIONS: The Pujiang Cataract Cohort Study has revealed the prevalence rates of cataract and cataract surgery among elderly individuals in suburban Shanghai, China. Although the frequency of cataract surgery has increased in China in recent decades, the high prevalence of cataract-related VI among older people suggests further attention to primary eyecare and medical awareness is necessary.

Association Between the Severity of Diabetic Retinopathy and Optical Coherence Tomography Angiography Metrics.

Diabetic retinopathy, the most serious ocular complication of diabetes, imposes a serious economic burden on society. Automatic and objective assessment of vessel changes can effectively manage diabetic retinopathy and prevent blindness. Optical coherence tomography angiography (OCTA) metrics have been confirmed to be used to assess vessel changes. The accuracy and reliability of OCTA metrics are restricted by vessel segmentation methods. In this study, a multi-branch retinal vessel segmentation method is proposed, which is comparable to the segmentation results obtained from the manual segmentation, effectively extracting vessels in low contrast areas and improving the integrity of the extracted vessels. OCTA metrics based on the proposed segmentation method were validated to be reliable for further analysis of the relationship between OCTA metrics and diabetes and the severity of diabetic retinopathy. Changes in vessel morphology are influenced by systemic risk factors. However, there is a lack of analysis of the relationship between OCTA metrics and systemic risk factors. We conducted a cross-sectional study that included 362 eyes of 221 diabetic patients and 1,151 eyes of 587 healthy people. Eight systemic risk factors were confirmed to be closely related to diabetes. After controlling these systemic risk factors, significant OCTA metrics (such as vessel complexity index, vessel diameter index, and mean thickness of retinal nerve fiber layer centered in the macular) were found to be related to diabetic retinopathy and severe diabetic retinopathy. This study provides evidence to support the potential value of OCTA metrics as biomarkers of diabetic retinopathy.

Inflammation is involved in response of gastric mucosal epithelial cells under simulated microgravity by integrated transcriptomic analysis.

Astronauts suffer from inflammatory changes induced by microgravity during space flight. Microgravity can significantly affect the inflammatory response of various cell types and multiple systems of the human body, such as cardiovascular system, skeletal muscle system, and digestive system. The aim of this research was to identify the key genes and pathways of gastric mucosa affected by microgravity. Human gastric mucosal epithelial GES-1 cells were cultured in a rotary cell culture system (RCCS) bioreactor to simulate microgravity. The gene expression profiles of GES-1 cells were obtained using Illumina sequencing platform and differentially expressed genes were identified by DESeq2 software, then Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. Subsequently, a protein-protein interaction (PPI) network was constructed. Compared with a normal gravity (NG) group, a total of 943 DEGs, including 192 downregulated genes and 751 upregulated genes, were identified. These DEGs were associated with findings that included response to interleukin-1, positive regulation of inflammatory response, and positive regulation of neuroinflammatory response. Furthermore, these DEGs were mainly enriched in herpes simplex virus 1 infection, cytokine-cytokine receptor interaction, and NOD-like receptor signaling pathway. Thus, 21 hub genes were identified from PPI network, including IL6, IL1B, ITGAM, CXCL8, ITGAX, CCL5, SERPINA1, APOE, CSF1R, VWF, GBP1, APOB, CYBB, HLA-DRB1, CD68, FGG, FGA, OASL, NOD2, OAS2 and FCGR2A. These findings suggested that simulated microgravity upregulated inflammation-related genes and pathways of GES-1 cells, which may play important roles in the response to microgravity and provide useful information for preventing mucosal damage in astronauts. In conclusion, this study revealed the key genes and pathways associated with simulated microgravity and indicated that simulated microgravity induced an inflammatory response in gastric mucosal epithelial cells.

Determination of water content in municipal sludge by multiple headspace extraction gas chromatography.

This paper reports a new method for the determination of sludge water content by a multiple headspace extraction gas chromatographic (MHE-GC) method. It is based on measuring the GC signals for the water vapor in a sample vial from the first five headspace extractions, from which the water content in the sludge sample can be extrapolated according to the established calculation equation. The results show that the method has a good repeatability (the relative standard deviation is less than 1%) and accuracy. The maximum relative difference is less than 16% compared to the reference method. The present method is very simple and efficient, and suitable for rapid sample testing in related applications.

A joint ROI extraction filter for computer aided lung nodule detection.

Extraction of regions of interest plays an important rule in computer aided lung nodules detection. However, because of the complex background and structure, accurate and robust extraction of ROIs in medical image still remains a problem. Aim at this problem, a two-stage operations joint filter: Hessian-LoB, is proposed. The first stage is blobs (which being taken as candidate ROIs) detection and the second stage is ROIs extraction. In the first stage, the derivatives of a Hessian matrix at multiple scales are convolved with input images to localize blobs. Then in the second stage, Laplacian of bilateral filter (LoB) is convolved with the detected blobs to extract the final ROIs. Experiments show that the proposed filter can deal with images with noise and low brightness contrast, and is effectively in ROI extraction for lung nodule detection.