Induced pluripotent stem cells (iPSCs) are considered to be ideal and promising cell sources for various applications such as regenerative medicine and drug screening. However, effective mass production systems for the stable supply of desired numbers of iPSCs are yet to be developed. This review introduces the various approaches that are currently available for stable iPSC production. We start by discussing the limiting factors to be controlled during iPSC culture, such as nutrient supply, waste removal, and oxygen availability. We then introduce recent investigations on iPSC culture systems based on adhesion, suspension, and scaffolds. We also discuss the downstream processes that follow the culture process, such as filling and freezing processes, which limit the production scale due to decreased cell viability during suspension in cryopreservation medium. Finally, we summarize the possibility of the stable mass production of iPSCs and highlight the limitations that remain to be overcome. We suggest that multidisciplinary investigations are essential to understand the different factors that influence cell growth and quality in order to obtain an optimal and stable iPSC mass production system.
We have previously developed a poly(L-lactic) acid (PLLA) bioengineered anterior cruciate ligament (ACL) matrix that has demonstrated enhanced healing when seeded with primary ACL cells prior to implantation in a rabbit model, as compared with the matrix alone. This suggests that improving cell adhesion on the matrix may beneficially affect the healing response and long-term performance of the bioengineered ACL matrix. One regenerative engineering approach involves enhancing the surface properties of the matrix to support cell adhesion and growth in combination with point-of-care stem cell therapy. Herein, we studied the cell adhesion properties of PLLA braided microfiber matrices enhanced through the physical adsorption of fibronectin and air plasma treatment. We evaluated the kinetics and binding efficiency of fibronectin onto matrices at three time points and three fibronectin concentrations. Incubating the matrix for 120 min in a solution of 25 μg·mL−1 fibronectin achieved the greatest binding efficiency to the matrix and cellular adhesion. Exposing the matrices to air plasma treatment for 5 min before fibronectin adsorption significantly enhanced the cell adhesion of rabbit bone marrow-derived mesenchymal stem cells (R-BMMSCs) 24 h post cell seeding. Finally, cellular proliferation was monitored for up to 21 d, the matrices were exposed to air plasma treatment, and fibronectin adsorption was found to result in enhanced cell number. These findings suggest that exposure to air plasma treatment and fibronectin adsorption enhances the cellular adhesion of PLLA braided microfiber matrices and may improve the clinical efficacy of the matrix in combination with point-of-care stem cell therapies.
We aimed to develop a disease risk comorbidity index (DRCI) based on disease risk index (DRI) and Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) in patients receiving haploidentical hematopoietic stem cell transplantation (haplo-HSCT). We identified the prognostic factors of disease-free survival (DFS) in a training subset (n = 593), then assigned a weighted score using these factors to the remaining patients (validation subset; n = 296). The multivariable model identified two independent predictors of DFS: DRI and HCT-CI before transplantation. In this scoring system, we assigned a weighted score of 2 to very high-risk DRI, and assigned a weighted score of 1 to high-risk DRI and intermediate- and high-risk HCT-CI (i.e., haplo-DRCI). In the validation cohort, the three-year DFS rate was 65.2% (95% confidence interval (CI), 58.2%–72.2%), 55.8% (95% CI, 44.9%–66.7%), and 32.0% (95% CI, 5.8%–58.2%) for the low-, intermediate-, and high-risk group, respectively (P = 0.005). Haplo-DRCI can also predict DFS in disease-specific subgroups, particularly in acute leukemia patients. Increasing score was also significantly predictive of increased relapse, increased non-relapse mortality (NRM), decreased DFS, and decreased overall survival (OS) in an independent historical cohort (n = 526). These data confirmed that haplo-DRCI could effectively risk stratify haplo-HSCT recipients and provide a tool to better predict who will best benefit from haplo-HSCT.
Genetic, lifestyle, and environmental factors contribute to the etiology of polycystic ovary syndrome (PCOS). Increased body mass index (BMI) exacerbates the reproductive and metabolic parameters and reduces the fecundity of women with PCOS. This is a secondary analysis of a large-sample, multicenter, randomized controlled trial conducted at 21 sites in Chinese mainland. A total of 1000 women diagnosed with PCOS were enrolled in this trial. Of these, 998 women with PCOS were included in the analysis. Increased BMI was associated with more severe menstrual irregularities, elevated testosterone level, higher prevalence of metabolic syndrome, and poorer quality of life. The rates of ovulation per woman for the normal, overweight, and obese BMI groups were 83.0%, 78.2%, and 63.6%, respectively (P < 0.001), and the rates of live birth were 23.6%, 18.1%, and 15.3% (P = 0.030). Northern PCOS patients showed more severe reproductive, glucose, and lipid profiles; less exercise; and lower total ovulation rates compared with PCOS patients from Southern China (74.8% vs 81.2%, absolute difference 6.4%, 95% confidence interval 1.2%–11.5%). The results show the typical phenotypic features of Han women with PCOS in Northern and Southern China. The women living in Northern China showed a higher BMI, more severe glycolipid metabolism profiles, and subsequently worse clinical outcomes by the same interventions than those living in Southern China. The difference in phenotypic features can be explained mostly by differences in BMI and the resulting difference in ovulation.
Conservation of endangered or economic fish and control of invasive fish is a great challenge of hydraulic engineering worldwide. Flow velocity has been recognized to affect the spawning of fishes delivering drifting eggs in rivers. However, solid scientific supports and associated mechanisms to establish quantitative relations between flow velocity and fish reproduction, taking into account spawning, fertilizing, hatching, as well as surviving, are lacking. In this paper, we quantified the relationship between flow velocity and reproduction of Chinese carps through both lab and field experiments. The results showed that a minimum velocity was required to trigger Hypophthalmichthys molitrix (H. molitrix) releasing eggs, and a velocity range was preferred to sustain spawning activity. However, the embryo incubation and larvae development of H. molitrix were found to be inhibited with the increase in flow velocity. Considering the requirements of spawning and hatching, as well as larvae surviving, an optimized flow velocity processes was identified for the reproduction of H. molitrix in rivers. These findings were of great significance to the adaptive operation of reservoirs to create reasonable and precise ecological flows for managing fish reproduction, as shown by the promising results in the engineering application to the Three Gorges Reservoir.
Many studies have been conducted on environmental flow (e-flow) assessment and supply, but e-flow shortages remain common in many urban rivers. In addition to known reasons such as ever-increasing competition among water users and inadequate execution of designed e-flow supply plans, we propose that designing weir heights without explicitly considering e-flows is another major cause of this problem. In this paper, we suggest that the measures for satisfying e-flows be extended from the water supply stage to the river channel design stage. We establish a new weir height determination framework that would more effectively satisfy the required e-flows. The new framework differs from previous frameworks, in which flood control and water retention are the major concerns and the flow during floods is set as the inflow. In the new framework, e-flow provision and flow velocity maintenance are added concerns and the actual flows for e-flow supply are set as the inflow. As a case study of the new framework's effectiveness, we applied it to the Shiwuli River in Hefei, China, a typical channelized urban river in China. The old framework specified too-high weir height to meet the e-flow requirements, whereas the new framework offered more reasonable heights that improved e-flow provision.
The problem of effluent total nitrogen (TN) at most of the wastewater treatment plants (WWTPs) in China is important for meeting the related water quality standards, even under the condition of high energy consumption. To achieve better prediction and control of effluent TN concentration, an efficient prediction model, based on controllable operation parameters, was constructed in a sequencing batch reactor process. Compared with previous models, this model has two main characteristics: ① Superficial gas velocity and anoxic time are controllable operation parameters and are selected as the main input parameters instead of dissolved oxygen to improve the model controllability, and ② the model prediction accuracy is improved on the basis of a feedforward neural network (FFNN) with algorithm optimization. The results demonstrated that the FFNN model was efficiently optimized by scaled conjugate gradient, and the performance was excellent compared with other models in terms of the correlation coefficient (R). The optimized FFNN model could provide an accurate prediction of effluent TN based on influent water parameters and key control parameters. This study revealed the possible application of the optimized FFNN model for the efficient removal of pollutants and lower energy consumption at most of the WWTPs.
Wastewater sludge creates a difficult environmental problem for many large cities. This study developed a three-phase innovative strategy for sludge treatment and reduction, including thermal hydrolysis, fungal fermentation, and anaerobic digestion. Increasing the temperature during the treatment from 140 to 180 °C significantly improved the sludge reduction and organic release efficiencies (p < 0.05, one-way analysis of variance (ANOVA) for the triplicate experiments at each temperature). After two cycles of thermal hydrolysis, the overall volatile solid (VS) reduction ratios of the sludge were 36.6%, 47.7%, and 58.5% for treatment at 140, 160, and 180 °C, respectively, and the total organic carbon (TOC) conversion efficiency reached 28.0%, 38.0%, and 45.1%, respectively. The highest concentrations of carbohydrates and proteins were obtained at 160 °C in sludge liquor, whereas the amount of humic substances significantly increased for the treatment at 180 °C (p < 0.05, one-way ANOVA for the triplicate experiments at each temperature) due to the Maillard reaction. Fungal fermentation of the hydrolyzed sludge liquor with Aspergillus niger converted the waste organics to valuable fiber materials. The biomass concentration of fungal hyphae reached 1.30 and 1.27 g·L−1 in the liquor of sludge treated at 140 and 160 °C, corresponding to organic conversion ratios of 24.6% and 24.0%, respectively. The fungal hyphae produced from the sludge liquor can be readily used for making papers or similar value-added fibrous products. The paper sheets made of hyphae fibers had a dense structure and strong strength with a tensile strength of 10.75 N·m·g−1. Combining fungal fermentation and anaerobic digestion, the overall organic utilization efficiency can exceed 75% for the liquor of sludge treated at 160 °C.
The paper briefly discusses the relationship between chronic diseases and gut health, and points out that an imbalance of intestinal microflora and an inadequate intake of dietary fiber are two important causes of chronic diseases. This paper also summarizes the research status of probiotic fermented fruit and vegetables, and discusses the main achievements of our group in this field and future developments of the related industry. The application of fermentation technology to fruit and vegetable processing and the development of a series of probiotic fermented fruit and vegetable products not only increase the added value of fruit and vegetables, but also organically combine probiotics and their active metabolites with prebiotics (dietary fiber, etc.), thereby promoting intestinal health as well as preventing and relieving chronic diseases. Fermentation technology provides a new approach to the study of the effect of probiotics on human health, and will have a revolutionary influence on probiotic application and on the fruit and vegetable processing industry. Thus, fruit and vegetable fermentation technology has excellent market potential.
The purpose of this study was to investigate the physicochemical properties and bioactivities of rice beans (Vigna umbellata) fermented by Bacillus amyloliquefaciens. The fermentation conditions were optimized on the basis of the fibrinolytic activity. Under the optimal fermentation conditions, the fibrinolytic activity reached a maximum of 78.0 FU·g−1 (4890 IU·g−1, fibrin plate method FU: fibrin degradation unit). The contents of peptides (which increased from 2.1 to 10.9 g per 100 g), total phenolics (from 116.7 to 388.5 mg gallic acid per 100 g), total flavonoids (from 235.5 to 354.3 mg rutin per 100 g), and anthocyanin (from 20.1 to 47.1 mg per 100 g), as well as the superoxide dismutase activity (from 55.3 to 263.6 U·g−1) in rice beans were significantly increased after fermentation. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) free radical scavenging activities and ferric reducing antioxidant power (FRAP) of fermented rice beans were 1.9–4.8 times higher than those of unfermented rice beans. Moreover, fermentation induced an increase in the dipeptidyl peptidase IV (DPP-IV) inhibition, α-glucosidase inhibition, and anticoagulant activities of rice beans. Rice beans fermented by Bacillus amyloliquefaciens may serve as a functional food with potential benefits for the prevention of thrombotic diseases.
A compact multi-throttle aerostatic guideway is the preferred structure for high precision and acceleration motion in the variable-slit system (VS) of photolithography. The presence of microstructure, such as recesses and grooves, on the guideway working surface has been found to improve the loading performance. Nevertheless, the effects on the guideway performance of changing the microstructure on the micron level are not yet clear. The mesh adaptation method, which was proposed by the authors, is employed in this paper to quantitatively study the influences of four microstructure parameters. The effect of tuning these parameters on the loading performance is revealed. The level of impact determines the proposed design process of the parameters. The characteristic feature of the proposed design process is that the working points of carrying capacity, stiffness, and rotational stiffness are unified under twoway adjusting by means of recess parameters. According to the proposed design process and tuning method, the restriction of supply pressure is lifted to a certain extent and the mutual tradeoff among the loading performances is relieved. The experimental results show that the rotational stiffness of the designed guideway, based on the tuned parameters, reached 2.14 × 104 Nm·rad−1 and increased by 69.8%. In a scanning test of the applied VS on argon fluoride laser (ArF) photolithography, the average scanning acceleration reached 67.5 m·s−2, meeting the design specification.
Disc cutter consumption is a critical problem that influences work performance during shield tunneling processes and directly affects the cutter change decision. This study proposes a new model to estimate the disc cutter life (Hf) by integrating a group method of data handling (GMDH)-type neural network (NN) with a genetic algorithm (GA). The efficiency and effectiveness of the GMDH network structure are optimized by the GA, which enables each neuron to search for its optimum connections set from the previous layer. With the proposed model, monitoring data including the shield performance database, disc cutter consumption, geological conditions, and operational parameters can be analyzed. To verify the performance of the proposed model, a case study in China is presented and a database is adopted to illustrate the excellence of the hybrid model. The results indicate that the hybrid model predicts disc cutter life with high accuracy. The sensitivity analysis reveals that the penetration rate (PR) has a significant influence on disc cutter life. The results of this study can be beneficial in both the planning and construction stages of shield tunneling.
Soyang Lake is the largest lake in Republic of Korea, bordering Chuncheon, Yanggu, and Inje in Gangwon Province. It is widely used as an environmental resource for hydropower, flood control, and water supply. Therefore, we conducted a survey of the floodplain of Soyang Lake to analyze the sediments in the area. We used global positioning system (GPS) data and aerial photography to monitor sediment deposits in the Soyang Lake floodplain. Data from three GPS units were compared to determine the accuracy of sampling location measurement. Sediment samples were collected at three sites: two in the eastern region of the floodplain and one in the western region. A total of eight samples were collected: Three samples were collected at 10 cm intervals to a depth of 30 cm from each site of the eastern sampling point, and two samples were collected at depths of 10 and 30 cm at the western sampling point. Samples were collected and analyzed for vertical and horizontal trends in particle size and moisture content. The sizes of the sediment samples ranged from coarse to very coarse sediments with a negative slope, which indicate eastward movement from the breach. The probability of a breach was indicated by the high water content at the eastern side of the floodplain, with the eastern sites showing a higher probability than the western sites. The results of this study indicate that analyses of grain fineness, moisture content, sediment deposits, and sediment removal rates can be used to understand and predict the direction of breach movement and sediment distribution in Soyang Lake.
In intercontinental trade and economics goods are bought from a global supplier. On occasion, the expected lot may include a fraction of defective items. These imperfect items still have worth and can be sold to customers after repair. It is cost-effective and sustainable to rework such items in nearby repair workshops rather than return them. The reworked items can be returned from the workshop to the buyer when shortages are equal to the quantity of imperfect items. In the meantime, the supplier correspondingly deals a multi-period delay-in-payments strategy with purchaser. The entire profit has been maximized with paybacks for interim financing. This study aims to develop a synergic inventory model to get the most profit by making an allowance for reworking, multi-period delay-in-payments policy, and shortages. The findings of the proposed model augment inventory management performance by monitoring cycle time as well as fraction of phase with optimistic inventory for a supply chain. The results demonstrate that profit is smaller if the permitted period given by supplier to buyer is equal to or greater than the cycle time, and profit is greater if the permitted period is smaller than the cycle time. The algebraic method is engaged to make a closed system optimum solution. The mathematical experiment of this study is constructed to provide management insights and tangible practices.