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Under the background of global climate change, crop leaves usually experience fluctuating light (FL) under compound stresses of drought and heat in the field. However, photoinhibition and photosynthetic regulation in FL under these compound stresses are little known. To elucidate this, we measured gas exchange, chlorophyll fluorescence, P700 redox state and electrochromic shift signals for tomato (Solanum lycopersicum) leaves exposed to FL under individual and compound stresses of moderate drought and heat stresses. After treatment with short‐term FL, photosystem I (PSI) activity decreased slightly in all treatments. By comparison, photosystem II (PSII) activity was reduced slightly under individual stress but largely decreased by 46% under compound stresses. Therefore, PSI is more tolerant than PSII when exposed to FL under compound stresses of drought and heat. Under compound stresses, PSII photoinhibition largely downregulated linear electron flow and photorespiration became a major electron sink downstream. Concomitantly, cyclic electron flow (CEF) was highly enhanced to help the building up of trans‐thylakoid proton gradient. This study highlights the importance of PSII activity and CEF in crop tolerance under future compound climate extremes such as drought and heat. [ABSTRACT FROM AUTHOR]

Photosynthetic CO2 assimilation (AN) under fluctuating light (FL) plays a critical role in plant growth and crop yield. C4 crops usually reach greater yields than C3 crops when grown in regions with low relative humidity, which might be partly due to the CO2 concentration mechanism and higher AN under FL of C4 crops. To test this hypothesis, we measured gas exchange and chlorophyll fluorescence under different changing frequencies of FL at contrasting relative air humidity (60% and 15%) for leaves of maize (Zea mays, C4) and tomato (Solanum lycopersicum, C3). In general, a more rapid changing frequency of FL would cause a larger loss in AN during shade‐sun transitions, with 20–38% in maize and 16–52% in tomato. Low relative humidity induced a larger decrease of stomatal conductance (gs) under FL in tomato than in maize, leading to a much stronger loss in AN in tomato than in maize. After transition from low to high light, AN of maize was mainly limited by gs with negligible non‐stomatal limitation, and the stomatal limitation was slightly affected by relative humidity. By comparison, low relative humidity significantly increased the stomatal limitation of AN in tomato but hardly affected non‐stomatal limitation. These results highlight the differential impact of decreasing relative humidity on dynamic photosynthesis and productivity between C3 and C4 crops. [ABSTRACT FROM AUTHOR]

The ability to establish significant phase modulation at low applied field provides a promising route toward polarization control and wavefront shaping for liquid‐crystal‐based devices. Owing to the polarization‐selective reflectivity of chiral liquid crystals (CLCs), reflective wavefront shaping via geometric phase is demonstrated when a circularly polarized light is Bragg reflected by a spatially orientated chiral layer. Nowadays, photoresponsive CLCs have attracted extensive attention due to their exotic feature that endows the CLC devices with the capability of electric‐free remote control. Despite the mature photoresponsive CLC materials and the sophisticated reflective geometric phase devices, a light‐induced topological optical phase modulation for a transmissive wave exiting a CLC cell remains elusive. Here, with the employment of a photosensitive chiral dopant, a hybrid aligned photoresponsive CLC system, demonstrating the simultaneous light modulation of topological geometric phase and dynamic phase via helical pitch manipulation is established. The continuous dual‐phase modulation engenders a smooth optically controllable diffraction efficiency (i.e., from <5% to >90%) of the proposed light‐reconfigurable CLC geometric phase optical element prototypes with multistable diffractive behavior, thus launching a paradigm shift for the application of novel liquid‐crystal photonic devices in the field of all‐optical polarization and spin processing. [ABSTRACT FROM AUTHOR]

Objective: Experiments were performed to evaluate CYLD expression in human gingival tissue samples and to examine the effects of CYLD on inflammatory responses in lipopolysaccharide (LPS)‐ or TNF‐α‐stimulated human gingival fibroblasts (HGFs). Methods: Immunohistochemistry for CYLD and p65 expression was performed with healthy and inflamed gingival tissue samples. siRNA was used to knock down the expression of CYLD in HGFs. Upon LPS or TNF‐α stimulation, NF‐κB activation was detected in control and CYLD‐knockdown HGFs. RT‐PCR was applied to determine gene expression. Western blot analyses were employed to assess protein expression. Immunofluorescence staining was carried out to evaluate the nuclear translocation of p65. Results: Immunohistochemical staining showed the expression of CYLD in human gingival tissues. In addition, CYLD protein expression was reduced in inflamed gingival tissue samples compared with healthy tissue samples. CYLD knockdown greatly enhanced the mRNA expression of proinflammatory cytokines in LPS‐ or TNF‐α‐stimulated HGFs. Furthermore, knocking down CYLD expression increased LPS‐stimulated NF‐κB activation in HGFs. Unexpectedly, CYLD knockdown did not affect TNF‐α‐induced NF‐κB activation. Conclusions: Our results suggest that CYLD participates in periodontal inflammatory responses by negatively regulating LPS‐induced NF‐κB signalling. [ABSTRACT FROM AUTHOR]

Background: Tai chi is considered a safe and low‐cost treatment for improving balance ability among an older population. However, there is no existing evidence on the optimal exercise parameters of tai chi for improving balance in older adults. Objectives: To investigate the optimal parameters of a tai chi intervention to improve balance performance of older adults. Design: Systematic review and meta‐analysis of randomized controlled trials (RCTs). Setting: PubMed, Embase, Cochrane Library, Web of Science, Scopus, China National Knowledge Infrastructure, Wanfang, Chinese Science and Technology Periodical and China Biology Medicine were searched from inception until November 30, 2020. Participants: Adults aged 60 years and over. Measurements: Two reviewers independently extracted the data and assessed the quality of the included studies according to the Physiotherapy Evidence Database (PEDro) scale. Subgroup analyses and meta‐regressions were conducted to elucidate the impact of tai chi training programs on balance measures. Results: Twenty‐six eligible RCTs were included in the meta‐analysis. Pooled results showed that tai chi has moderate effects for improving proactive balance (weighted mean standardized mean differences [SMDwm] = 0.61, 95% CI 0.33–0.89) and static steady‐state balance (SMDwm = 0.62, 95% CI 0.30–0.95) and small effects for improving dynamic steady‐state balance (SMDwm = 0.38, 95% CI 0.03–0.73) and balance test batteries (SMDwm = 0.47, 95% CI 0.13–0.81) in adults over 60 years of age. The practice frequency could predict the effects of tai chi on static steady‐state balance, and the 24‐form simplified Yang style tai chi (45–60 min/session, more than four sessions per week and at least 8 weeks) was the most optimal. Conclusions: Tai chi is effective at improving the balance ability of adults over 60 years of age. A medium duration and high frequency of 24‐form tai chi may be the optimal program for improving balance, but this evidence should be recommended with caution due to limitations of the methodology and small sample sizes. [ABSTRACT FROM AUTHOR]

Cancer stem cells (CSCs) are considered to play essential roles in the process of origination, proliferation, migration, and invasion of cancer, and their properties are regulated by Wnt/β-catenin pathway. Phenethyl isothiocyanate (PEITC) is a natural product obtained from cruciferous vegetables with anticancer activities. The present study aimed to investigate the inhibitory effect and the underlying mechanisms of PEITC on colorectal CSCs. In this study, we found that PEITC can significantly reduce the size and number of colorectal cancer cell spheroids in serum-free medium. With increasing PEITC concentrations (10-40 μM), the number of spheroids was reduced to about 10% of the control group, and the percentage of CD133+ cells was decreased by about 3-16 folds. PEITC also decreased the expression of CSC markers. Meanwhile, inhibition of proliferation as well as induction of apoptosis of colorectal CSCs was observed after PEITC treatment. Furthermore, through activating Wnt/β-catenin pathway with LiCl, the inhibitory effects of PEITC on colorectal CSCs were diminished. Our data suggested that PEITC can be an effective inhibitor of colorectal CSCs by targeting Wnt/β-catenin pathway. [ABSTRACT FROM AUTHOR]

Objective: Macrophages could be fully polarized and acquire specific phenotype like M1, which considered to be essential for the alveolar bone destruction during the development of periodontitis. However, the molecular mechanisms underlying the effects of M1 macrophages on the alveolar bone destruction are still not clear yet. Methods: Mouse periodontitis model was established to determine the involvement of M1 macrophages in the pathogenic process. Condition medium of the M1 macrophages (M1‐CM) was incubated with pre‐osteoblasts to evaluate its effects on the osteoblastogenesis. Cells after treatment with CM were used for RNA‐sequencing, quantitative PCR, Western blotting, and immunofluorescence staining to figure out pathways involved in the inhibition of osteoblastogenesis. Results: Increased infiltration of M1 macrophages was associated with alveolar bone destruction in periodontitis. M1‐CM markedly suppressed the generation of osteoblasts as evidenced by decreased expressions of Runx2 and Ocn, as well as reduced activity of ALP. Interestingly, RNA‐sequencing indicated the activation of TLR4/AP1 signaling pathway in pre‐osteoblasts treated with CM. Inhibition of TLR4 reduced the translocation of AP1 and rescued the osteoblastogenesis reduced by M1‐CM. Conclusion: M1 macrophages induce TLR4/AP1 signaling of pre‐osteoblasts to inhibit the osteoblastogenesis via paracrine, at least partially contributing to alveolar bone destruction in periodontitis. [ABSTRACT FROM AUTHOR]

A reliable distributed covariance intersection (CI) fusion integrated navigation algorithm with information feedback during the Mars atmospheric entry is proposed to meet robust, reliable, and high-precision Mars atmospheric entry navigation strategy. A distributed integrated navigation scheme includes four independent subsystems consisting of an IMU and one radio beacon, but each subsystem is weakly observable under limited Mars entry measurements. The scalar weights are fast obtained by maximizing the information contribution of the corresponding estimate. The distributed framework based upon the CI fusion algorithm is designed by using dynamic information distribution coefficients and information feedback strategy. This distributed fusion approach could meet the lower computation cost and robust and reliable capacity and especially is beneficial to the weakly observable or unobservable subsystems during the Mars entry navigation scheme. Numerical simulations show that the proposed distributed CI fusion integrated navigation algorithm can provide consistent navigation accuracy for the Mars entry vehicle and improve the entry navigation robustness under the weakly observable navigation subsystems. [ABSTRACT FROM AUTHOR]

Cancer stem cells (CSCs) are highly implicated in the progression of human cancers. Thus, targeting CSCs may be a promising strategy for cancer therapy. Wnt/β-catenin and Sonic Hedgehog pathways play an important regulatory role in maintaining CSC characteristics. Natural compounds, such as curcumin, possess chemopreventive properties. However, the interventional effect of curcumin on lung CSCs has not been clarified. In the present study, tumorsphere formation assay was used to enrich lung CSCs from A549 and H1299 cells. We showed that the levels of lung CSC markers (CD133, CD44, ALDHA1, Nanog and Oct4) and the number of CD133-positive cells were significantly elevated in the sphere-forming cells. We further illustrated that curcumin efficiently abolished lung CSC traits, as evidenced by reduced tumorsphere formation, reduced number of CD133-positive cells, decreased expression levels of lung CSC markers, as well as proliferation inhibition and apoptosis induction. Moreover, we demonstrated that curcumin suppressed the activation of both Wnt/β-catenin and Sonic Hedgehog pathways. Taken together, our data suggested that curcumin exhibited its interventional effect on lung CSCs via inhibition of Wnt/β-catenin and Sonic Hedgehog pathways. These novel findings could provide new insights into the potential therapeutic application of curcumin in lung CSC elimination and cancer intervention. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]