Content of oxygen in water is a critical factor in increasing bioremediation efficiency for contaminated groundwater. Micro-nano bubbles (MNBs) injection seems to be an effective technique for increasing oxygen in water compared with traditional air sparging technology with macrobubbles. Micro-nano bubbles have larger interfacial area, higher inner pressure and density, and lower rising velocity in water, superior to that of macrobubbles. In this paper, MNBs with diameters ranging from 500 nm to 100 lm are investigated, with a specific focus on the oxygen mass transfer coefficient from inner bubbles to surrounding water. The influence of surfactant on the bubbles formation and dissolution is studied as well. The stability of MNBs is further investigated by means of zeta potential measurements and rising velocity analysis. The results show that MNBs can greatly increase oxygen content in water. Higher surfactant concentration in water will decrease the bubbles size, reduce the dissolution rate, and increase the zeta potential. Moreover, MNBs with greater zeta potential value tend to be more stable. Besides, the low rising velocity of MNBs contributes to the long stagnation in water. It is suggested that micro-nano bubble aeration, a potential in groundwater remediation technology, can largely enhance the bioremediation effect. Water Environ. Res., 86, 844 (2014).
Micro-nano bubbles (MNBs) technology has shown great potential in groundwater bioremediation because of their large specific surface area, negatively charged surface, long stagnation, high oxygen transfer efficiency, etc. Groundwater salinity, which varies from sites due to different geological and environmental conditions, has a strong impact on the bioremediation effect. However, the groundwater salinity effect on MNBs’ behavior has not been reported. In this study, the size distribution, oxygen transfer efficiency and zeta potential of MNBs was investigated in different salt concentrations. In addition, the permeability of MNBs’ water through sand in different salt concentrations was studied. The results showed that water salinity has no influence on bubble size distribution during MNBs generation. MNBs could greatly enhance the oxygen transfer efficiency from inner bubbles to outer water, which may greatly enhance aerobic bioremediation. However, the enhancement varied depending on salt concentration. 0.7 g/L was found to be the optimal salt concentration to transfer oxygen. Moreover, MNBs in water salinity of 0.7 g/L had the minimum zeta potential. The correlation of zeta potential and mass transfer was discussed. The hydraulic conductivities of sand were similar for MNBs water with different salt concentrations. The results suggested that salinity had a great influence on MNBs performance, and groundwater salinity should be taken into careful consideration in applying MNBs technology to the enhancement of bioremediation.
There is a lack of useful biomarkers for predicting the efficacy of anti–programmed death-1 (PD-1) therapy for advanced gastric and colorectal cancer. To address this issue, in this study we investigated the correlation between inflammatory marker expression and survival in patients with advanced gastric and colorectal cancer. Data for 111 patients with advanced gastric and colorectal cancer treated with anti–PD-1 regimens were retrospectively analyzed. Neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and clinical characteristics of each patient were selected as the main variables. Overall response rate, disease control rate, and progression-free survival were primary endpoints, and overall survival and immune-related adverse events (irAEs) were secondary endpoints. The chi-squared test and Fisher’s exact test were used to evaluate relationships between categorical variables. Uni- and multivariate Cox regression analyses were performed, and median progression-free survival and overall survival were estimated with the Kaplan–Meier method. The overall response rate and disease control rate of anti–PD-1therapy in advanced gastric and colorectal tumors were 12.61 and 66.66%, respectively. The patients with MLR < 0.31, NLR < 5, and PLR < 135 had a significantly higher disease control rate than those with MLR > 0.31, NLR > 5, and PLR > 135 (P < 0.05). The multivariate analysis revealed that MLR < 0.31, BMI > 18.5, and anti–PD-1 therapy in first-line were associated with prolonged PFS. MLR < 0.31 and BMI > 18.5 were associated with prolonged overall survival. The irAE rate differed significantly between PLR groups, and PLR < 135 was associated with an increased rate of irAEs (P = 0.028). These results indicate that the inflammatory markers NLR, MLR, and PLR have clinical utility for predicting survival or risk of irAEs in patients with advanced gastric cancer and colorectal cancer.
Micro-nano bubbles (MNBs) are tiny bubbles with diameters on the order of micrometers and nanometers, showing great potential in environmental remediation. However, the application is only in the beginning stages and remains to be intensively studied. In order to explore the possible use of MNBs in groundwater contaminant removal, this study focuses on the transport of MNBs in porous media and dissolution processes. The bubble diameter distribution was obtained under different conditions by a laser particle analyzer. The permeability of MNB water through sand was compared with that of air-free water. Moreover, the mass transfer features of dissolved oxygen in water with MNBs were studied. The results show that the bubble diameter distribution is influenced by the surfactant concentration in the water. The existence of MNBs in pore water has no impact on the hydraulic conductivity of sand. Furthermore, the dissolved oxygen (DO) in water is greatly increased by the MNBs, which will predictably improve the aerobic bioremediation of groundwater. The results are meaningful and instructive in the further study of MNB research and applications in groundwater bioremediation.
and aseptic inflammation are induced, proliferation of fibrosis tissue is promoted, which in turn induces the formation of fibrotic encapsulation and postoperative tissue adhesion. [3][4][5] In response to these phenomena, recent studies have mainly focused on optimizing the properties of the biomaterials. However, the impact on the microenvironment triggered by the implants from an immune biological viewpoint has been neglected. [6][7][8] Currently, the internal mechanism underlying implants in the peripheral immune microenvironment remains unknown, and this has substantially limited the application of biomaterials.As a host immune defense mechanism, FBR to implants occurs in the following steps: after implantation of biomaterials in the body, the first stage of FBR is non-specific protein adsorption on the implant surface which serves as binding sites for inflammatory cells. Thereafter, infiltrating neutrophils and macrophages from peripheral blood recognize the binding sites and integrate with the surface of biomaterials. This induces the formation of the inflammatory microenvironment. [9] Inflammatory factors released by locally enriched macrophages recruit and drive the differentiation of fibroblasts to myofibroblasts. Finally, myofibroblasts secrete large amounts of collagen (Col) and matrix metallopeptidase (MMP), ultimately resulting in Foreign body reactions (FBR) to implants seriously impair tissue-implant integration and postoperative adhesion. The macrophage, owing to its phenotypic plasticity, is a major regulator in the formation of the inflammatory microenvironment; NF-κB signaling also plays a vital role in the process. It is hypothesized that NF-κB phosphorylation exerts a proinflammatory regulator in FBR to polylactide membranes (PLA-M) and adhesion. First, in vitro and in vivo experiments show that PLA-M induces NF-κB phosphorylation in macrophages, leading to M1 polarization and release of inflammatory factors. The inflammatory microenvironment formed due to PLA-M accelerates myofibroblast differentiation and release of collagen III and MMP2, jointly resulting in peritendinous adhesion. Therefore, JSH-23 (a selective NF-κB inhibitor)-loaded PLA membrane (JSH-23/PLA-M) is fabricated by blend electrospinning to regulate the associated M1 polarization for peritendinous anti-adhesion. JSH-23/PLA-M specifically inhibits NF-κB phosphorylation in macrophages and exhibits anti-inflammatory and anti-adhesion properties. The findings demonstrate that NF-κB phosphorylation has a critical role in PLA-induced M1 polarization and aggravating FBR to PLA-M. Additionally, JSH-23/PLA-M precisely targets modulation of NF-κB phosphorylation in FBR to break the vicious cycle in peritendinous adhesion therapy.
Aging promotes most degenerative pathologies in mammals, which are characterized by progressive decline of function at molecular, cellular, tissue, and organismal levels and account for a host of health care expenditures in both developing and developed nations. Sarcopenia is a prominent age-related disorder in musculoskeletal system. Defined as gradual and generalized chronic skeletal muscle disorder, sarcopenia involves accelerated loss of muscle mass, strength and function, which is associated with increased adverse functional outcomes and evolutionally refers to muscle wasting accompanied by other geriatric syndromes. More efforts have been made to clarify mechanisms underlying sarcopenia and new findings suggest that it may be feasible to delay age-related sarcopenia by modulating fundamental mechanisms such as cellular senescence. Cellular senescence refers to the essentially irreversible growth arrest mainly regulated by p53/p21CIP1 and p16INK4a/pRB pathways as organism ages, possibly detrimentally contributing to sarcopenia via muscle stem cells (MuSCs) dysfunction and the senescence-associated secretory phenotype (SASP) while cellular senescence may have beneficial functions in counteracting cancer progression, tissue regeneration and wound healing. By now diverse studies in mice and humans have established that targeting cellular senescence is a powerful strategy to alleviating sarcopenia. However, the mechanisms through which senescent cells contribute to sarcopenia progression need to be further researched. We review the possible mechanisms involved in muscle stem cells (MuSCs) dysfunction and the SASP resulting from cellular senescence, their associations with sarcopenia, current emerging therapeutic opportunities based on targeting cellular senescence relevant to sarcopenia, and potential paths to developing clinical interventions genetically or pharmacologically.
Abstract:The thermodynamic behavior of asphalt mixtures is critical to the engineers since it directly relates to the damage in asphalt mixtures. However, most of the current research of the freeze-thaw damage of asphalt mixtures is focused on the bulk body from the macroscale and lacks a fundamental understanding of the thermodynamic behaviors of asphalt mixtures from the microscale perspective. In this paper, to identify the important thermodynamic behaviors of asphalt mixtures under freeze-thaw loading cycle, the information entropy theory, an X-ray computerized tomography (CT) scanner and digital image processing technology are employed. The voids, the average size of the voids, the connected porosity, and the void number are extracted according to the scanned images. Based on the experiments and the CT scanned images, the information entropy evolution of the asphalt mixtures under different freeze-thaw cycles is calculated and the relationship between the change of information entropy and the pore structure characteristics is established. Then, the influences of different freezing and thawing conditions on the thermodynamic behaviors of asphalt mixtures are compared. The combination of information entropy theory and CT scanning technique proposed in this paper provides an innovative approach to investigate the thermodynamics behaviors of asphalt mixtures and a new way to analyze the freeze-thaw damage in asphalt mixtures.
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