As the biocompatible materials, hydrogels have been widely used in three- dimensional (3D) bioprinting/organ printing to load cell for tissue engineering. It is important to precisely control ...hydrogels deposition during printing the mimic organ structures. However, the printability of hydrogels about printing parameters is seldom addressed. In this paper, we systemically investigated the printability of hydrogels from printing lines (one dimensional, 1D structures) to printing lattices/films (two dimensional, 2D structures) and printing 3D structures with a special attention to the accurate printing. After a series of experiments, we discovered the relationships between the important factors such as air pressure, feedrate, or even printing distance and the printing quality of the expected structures. Dumbbell shape was observed in the lattice structures printing due to the hydrogel diffuses at the intersection. Collapses and fusion of adjacent layer would result in the error accumulation at Z direction which was an important fact that could cause printing failure. Finally, we successfully demonstrated a 3D printing hydrogel scaffold through harmonize with all the parameters. The cell viability after printing was compared with the casting and the results showed that our bioprinting method almost had no extra damage to the cells.
Drought is one of the major factors limiting global maize production. Exposure to long-term drought conditions inhibits growth and leads to yield losses. Although several drought-responsive genes ...have been identified and functionally analyzed, the mechanisms underlying responses to drought and water recovery treatments have not been fully elucidated. To characterize how maize seedling respond to drought stress at the transcriptional level, we analyzed physiological responses and differentially expressed genes (DEGs) in the inbred line B73 under water deficit and recovery conditions.
The data for relative leaf water content, leaf size, and photosynthesis-related parameters indicated that drought stress significantly repressed maize seedling growth. Further RNA sequencing analysis revealed that 6107 DEGs were responsive to drought stress and water recovery, with more down-regulated than up-regulated genes. Among the DEGs, the photosynthesis- and hormone-related genes were enriched in responses to drought stress and re-watering. Additionally, transcription factor genes from 37 families were differentially expressed among the three analyzed time-points. Gene ontology enrichment analyses of the DEGs indicated that 50 GO terms, including those related to photosynthesis, carbohydrate metabolism, oxidoreductase activities, nutrient metabolism and other drought-responsive pathways, were over-represented in the drought-treated seedlings. The content of gibberellin in drought treatment seedlings was decreased compared to that of control seedlings, while abscisic acid showed accumulated in the drought treated plants. The deep analysis of DEGs related to cell wall development indicated that these genes were prone to be down-regulated at drought treatment stage.
Many genes that are differentially expressed in responses to drought stress and water recovery conditions affect photosynthetic systems and hormone biosynthesis. The identified DEGs, especially those encoding transcription factors, represent potential targets for developing drought-tolerant maize lines.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The purpose of this article is to establish a prediction model of joint movements and realize the prediction of joint movemenst, and the research results are of reference value for the development of ...the rehabilitation equipment. This will be carried out by analyzing the impact of surface electromyography (sEMG) on ankle movements and using the Hill model as a framework for calculating ankle joint torque. The table and scheme used in the experiments were based on physiological parameters obtained through the model. Data analysis was performed on ankle joint angle signal, movement signal, and sEMG data from nine subjects during dorsiflexion/flexion, varus, and internal/external rotation. The Hill model was employed to determine 16 physiological parameters which were optimized using a genetic algorithm. Three experiments were carried out to identify the optimal model to calculate torque and root mean square error. The optimized model precisely calculated torque and had a root mean square error of under 1.4 in comparison to the measured torque. Ankle movement models predict torque patterns with accuracy, thereby providing a solid theoretical basis for ankle rehabilitation control. The optimized model provides a theoretical foundation for precise ankle torque forecasts, thereby improving the efficacy of rehabilitation robots for the ankle.
Bad sitting posture is harmful to human health. Intelligent sitting posture recognition algorithm can remind people to correct their sitting posture. In this paper, a sitting pressure image ...acquisition system was designed. With the system, we innovatively proposed a hip positioning algorithm based on hip templates. The average deviation of the algorithm for hip positioning is 1.306 pixels (the equivalent distance is 1.50 cm), and the proportion of the maximum positioning deviation less than three pixels is 94.1%. Statistics show that the algorithm works relatively well for different subjects. At the same time, the algorithm can not only effectively locate the hip position with a small rotation angle (0°-15°), but also has certain adaptability to the sitting posture with a medium rotation angle (15°-30°) or a large rotation angle (30°-45°). Using the hip positioning algorithm, the regional pressure values of the left hip, right hip and caudal vertebrae are effectively extracted as the features, and support vector machine (SVM) with polynomial kernel is used to classify the four types of sitting postures, with a classification accuracy of up to 89.6%.
CRISPR/Cas （clustered regularly interspaced short palindromic repeats/CR1SPR-associated proteins） is an adaptive immune system in bacteria and archaea to defend against invasion from foreign DNA ...fragments. Recently, it has been developed as a powerful targeted genome editing tool for a wide variety of species. However, its application in maize has only been tested with transiently expressed somatic cells or with a limited number of stable transgenic To plants. The exact efficiency and specificity of the CRISPR/Cas system in the highly complex maize genome has not been documented yet. Here we report an extensive study of the well-studied type II CRISPR-Cas9 system for targeted genome editing in maize, with the codon-optimized Cas9 protein and the short non-coding guide RNA generated through a functional maize U6 snRNA promoter. Targeted gene mutagenesis was detected for 90 loci by maize protoplast assay, with an average cleavage efficiency of 10.67 %. Stable knockout transformants for maize phytoene synthase gene （PSYI） were obtained. Mutations occurred in germ ceils can be stably inherited to the next generation. Moreover, no off-target effect was detected at the computationally predicted putative off-target loci. No significant difference between the transcriptomes of the Cas9 expressed and non-expressed lines was detected. Our results confirmed that the CRISPR-Cas9 could be successfully applied as a robust targeted genome editing system in maize.
Long-range chromatin interactions are important for transcriptional regulation of genes, many of which are related to complex agronomics traits. However, the pattern of three-dimensional chromatin ...interactions remains unclear in plants. Here we report the generation of chromatin interaction analysis by paired-end tag sequencing (ChIA-PET) data and the construction of extensive H3K4me3- and H3K27ac-centered chromatin interaction maps in maize. Results show that the interacting patterns between proximal and distal regulatory regions of genes are highly complex and dynamic. Genes with chromatin interactions have higher expression levels than those without interactions. Genes with proximal-proximal interactions prefer to be transcriptionally coordinated. Tissue-specific proximal-distal interactions are associated with tissue-specific expression of genes. Interactions between proximal and distal regulatory regions further interweave into organized network communities that are enriched in specific biological functions. The high-resolution chromatin interaction maps will help to understand the transcription regulation of genes associated with complex agronomic traits of maize.
•This review assessed the contamination levels of PAE in various ecosystems.•Overviewed the current status of PAE-degrading bacterial isolates and communities.•Discussed the challenges for ...understanding in situ PAE biodegradation mechanisms.•Proposed a guide of building synthetic community to decipher interaction mechanism.
The extensive use of phthalic acid esters (PAEs) has led to their widespread distribution across various environments. As PAEs pose significant threats to human health, it is urgent to develop efficient strategies to eliminate them from environments. Bacteria-driven PAE biodegradation has been considered as an inexpensive yet effective strategy to restore the contaminated environments. Despite great advances in bacterial culturing and sequencing, the inherent complexity of indigenous microbial community hinders us to mechanistically understand in situ PAE biodegradation and efficiently harness the degrading power of bacteria. The synthetic microbial ecology provides us a simple and controllable model system to address this problem. In this review, we focus on the current progress of PAE biodegradation mediated by bacterial isolates and indigenous bacterial communities, and discuss the prospective of synthetic PAE-degrading bacterial communities in PAE biodegradation research. It is anticipated that the theories and approaches of synthetic microbial ecology will revolutionize the study of bacteria-driven PAE biodegradation and provide novel insights for developing effective bioremediation solutions.
Background
Geriatric nutritional risk index (GNRI) is an indicator of nutritional status derived by serum albumin level and ideal body weight, which has been proposed as a predictor of prognosis for ...elderly population with various clinical conditions. The objective of the meta-analysis was to comprehensively evaluate the association between baseline GNRI and survival of patients with colorectal cancer (CRC).
Methods
Cohort studies were identified by search of PubMed, Embase, and Web of Science databases from inception to January 05, 2022 according to the aim of the meta-analysis. A random-effect model incorporating the potential between-study heterogeneity was adopted to pool the results.
Results
Nine studies including 3658 patients with CRC contributed to the meta-analysis. Results showed that CRC patients with lower GNRI at baseline had worse overall survival (OS, hazard ratio HR 2.39, 95% confidence interval CI 1.78-3.23, p<0.001; I
2 =
60%) and progression-free survival (PFS, HR 1.77, 95% CI 1.38-2.26, p<0.001; I
2 =
33%). The results were consistent in sensitivity analyses limited to elderly patients (HR for OS 2.25, p<0.001; HR for PFS 1.65, p=0.003). Subgroup analyses showed consistent results in patents with different cancer stages, and in studies with median follow-up < and ≥ 5 years (p for subgroup effects all < 0.05).
Conclusion
A lower GNRI at baseline may be independent associated with poor survival outcomes of patients with CRC. Evaluating the nutritional status using GNRI may be important for risk stratification of patients with CRC.
Summary
Plants can respond to environmental changes with various mechanisms occurred at transcriptional and translational levels. Thus far, there have been relatively extensive understandings of ...stress responses of plants on transcriptional level, while little information is known about that on translational level. To uncover the landscape of translation in plants in response to drought stress, we performed the recently developed ribosome profiling assay with maize seedlings growing under normal and drought conditions. Comparative analysis of the ribosome profiling data and the RNA‐seq data showed that the fold changes of gene expression at transcriptional level were moderately correlated with that of translational level globally (R2 = 0.69). However, less than half of the responsive genes were shared by transcription and translation under drought condition, suggesting that drought stress can introduce transcriptional and translational responses independently. We found that the translational efficiencies of 931 genes were changed significantly in response to drought stress. Further analysis revealed that the translational efficiencies of genes were highly influenced by their sequence features including GC content, length of coding sequences and normalized minimal free energy. In addition, we detected potential translation of 3063 upstream open reading frames (uORFs) on 2558 genes and these uORFs may affect the translational efficiency of downstream main open reading frames (ORFs). Our study indicates that plant can respond to drought stress with highly dynamic translational mechanism, that acting synergistically with that of transcription.
Significance Statement
Transcriptional changes upon drought stress are well known, but relatively few studies have considered translational changes. Here comparative analyses show that plants can respond to drought stress with highly dynamic translational changes, which function independently and synergistically with the transcriptional response.
PDF
