Background/Aims: Programmed death ligand1(PD-L1) plays a role in the development and progression of non-small cell lung cancer (NSCLC). This study aimed to identify miRNA(s) that are responsible for ...regulation of expression of PD-L1 in NSCLC, and to investigate the role of PD-L1 in regulation of the cell cycle in NSCLC. Methods: We predicted the target miRNA of PD-L1, which was miR-140, using the online tools TargetScan and miBase. In NSCLC cells obtained from clinical specimens, in addition to A549 and NCI-H1650 cell cultures, western blots were used to detect the level of expression of proteins, while real-time PCR was used to determine the level of expression of PD-L1, miR-140, cyclin E, and β-actin. Transfection with miR-140 mimics, miR-140 inhibitors, and PD-L1 siRNA were conducted using commercial kits. To determine whether miR-140 directly binds PD-L1, a luciferase reporter gene with wild type or mutated PD-L1 was used. Cell viability was measured with the MTT assay, and PI staining was used for cell cycle analysis. Results: We found low expression of miR-140 and high expression of PD-L1 and cyclin E in NSCLC cells. Over-expression of miR-140 suppressed the expression of PD-L1 by directly binding its 3’ UTR, and was also associated with decreased expression of cyclin E and inhibition of cellular proliferation in A549 and NCI-H1650 cells. Inhibition of PD-L1, in the absence of manipulations to miR-140, also decreased the expression of cyclin E. Conclusion: We conclude that miR-140 directly suppresses PD-L1 and inhibits the miR-140/PD-L1/cyclin E pathway in NSCLC.
This protocol provides a detailed procedure for the chemical synthesis of proteins through native chemical ligation of peptide hydrazides. The two crucial stages of this protocol are (i) the ...solid-phase synthesis of peptide hydrazides via Fmoc chemistry and (ii) the native chemical ligation of peptide hydrazides through in situ NaNO2 activation and thiolysis. This protocol may be of help in the synthesis of proteins that are not easily produced by recombinant technology and that include acid-sensitive modifications; it also does not involve the use of hazardous HF. The utility of the protocol is shown for the total synthesis of 140-aa-long α-synuclein, a protein that has an important role in the development of Parkinson's disease. The whole synthesis of the target protein α-synuclein in milligram scale takes ~30 working days.
Regional specification of PM2.5 pollution characteristics is crucial for pollution control and policymaking. Spatiotemporal variations of six criteria air pollutants and influencing factors in China ...were studied using hourly concentrations of PM2.5, PM10, SO2, NO2, CO, and O3 from 2015 to 2016. China was categorized into eight regions: north-east, northern coastland, eastern coastland, southern coastland, Yellow River middle reaches, Yangtze River middle reaches, south-west, and north-west. The 29 exemplary cities in China were also researched. It was found that the PM2.5 concentration in the northern coastland (Beijing–Tianjin–Hebei–Shandong) was the highest (72.28 μg.m−3) among the eight regions, particularly in the city of Baoding, Hebei, which had an annual average PM2.5 concentration of 98.53 μg.m−3. Average PM2.5 concentrations in 2015 and 2016 of China were 50.16 μg.m−3 and 46.61 μg.m−3, respectively. Compared with 2015, the PM2.5 concentration decreased by 8.41% in 2016, the decline of PM2.5 in summer was the largest, followed by autumn, spring and winter. The average mean PM2.5 concentrations of the 29 exemplary cities in 2015 and 2016 were 54.66 μg.m−3 and 48.37 μg.m−3, respectively, exceeding the limit for grade 2 of the national standards (35 μg.m−3). National air pollution distribution has exploded geographically with influence of regional economic factors. Gaseous pollutant as well as geographical and socio-economic conditions influenced PM2.5 emissions. Effects of these factors on PM2.5 emissions varied across regions and decreased continuously from the northern region to the south-west and eastern coastland regions. This paper clearly identifies the regional characteristics and distribution of PM2.5, focusing on the effects of gaseous pollutant, geography and socio-economic development. Secondary transformation and vehicle exhaust across regions should be further studied.
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•The results show that average PM2.5 concentrations in 2015 and 2016 were 50.16 and 46.61 μg/m3, respectively.•Compared to 2015, the concentration decreased by 8.41% in 2016.•Considering regional differences, the northern coastland, Yellow River middle reaches and Yangtze River middle reaches had higher PM2.5 concentrations relative to other areas.•Gaseous pollutant, socio-economic and geographic influence PM2.5 emissions.•It was found that the influence factors on PM2.5 emissions vary by region and decrease continuously from the central to western and eastern regions.•Results reveal heavy air pollution at lower elevations and in basins.•Secondary transformation and vehicle exhaust in different regions need further study.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A hybrid design method for broadband radar cross section (RCS) reduction based on reflection diffusion is proposed and successfully demonstrated. To this end, we first analyze the scattering behavior ...of full parabolic-phased metasurface and find out its weaknesses in achieving perfect diffusive patterns. Then, we alleviate the issue of full parabolic-phased method through hybridizing two strategies, i.e., concave/convex chessboard arrangement and random focal lengths. The proposed hybrid design makes the phase profile aperiodic without any mirror symmetry, which is the key for achieving perfect diffusive scattering behavior within a wide operation band. The numerical and experimental results show that our proposed design features broadband, polarization insensitivity, and wide incidence angle and can efficiently decrease the RCS more than 10 dB within 7.8-23.2 GHz. Our approach comprehensively solves the issues of narrow band, high bistatic RCS value, time-consuming optimization process, and sensitivity to different polarization and incident angles, promising great potential in stealth applications.
The pure culture of prokaryotes remains essential to elucidating the role of these organisms. Scientists have reasoned that hard to cultivate microorganisms might grow in pure culture if provided ...with the chemical components of their natural environment. However, most microbial species in the biosphere that would otherwise be "culturable" may fail to grow because of their growth state in nature, such as dormancy. That means even if scientist would provide microorganisms with the natural environment, such dormant microorganisms probably still remain in a dormant state.
We constructed an enrichment culture system for high-efficiency isolation of uncultured strains from marine sediment. Degree of enrichment analysis, dormant and active taxa calculation, viable but non-culturable bacteria resuscitation analysis, combined with metatranscriptomic and comparative genomic analyses of the interactions between microbial communications during enrichment culture showed that the so-called enrichment method could culture the "uncultured" not only through enriching the abundance of "uncultured," but also through the resuscitation mechanism. In addition, the enrichment culture was a complicated mixed culture system, which contains the competition, cooperation, or coordination among bacterial communities, compared with pure cultures.
Considering that cultivation techniques must evolve further-from axenic to mixed cultures-for us to fully understand the microbial world, we should redevelop an understanding of the classic enrichment culture method. Enrichment culture methods can be developed and used to construct a model for analyzing mixed cultures and exploring microbial dark matter. This study provides a new train of thought to mining marine microbial dark matter based on mixed cultures.
In order to effectively prevent and control spontaneous combustion of residual coal in the goaf and reduce the waste of nitrogen caused by setting the position of nitrogen injection, 1303 fully ...mechanized coal caving faces of the Jinniu Mine are studied. By deploying a bundle tube monitoring system in the inlet air side and return air side of the goaf, changes in gas concentration in the goaf are continuously monitored. In addition, the distribution area for spontaneous combustion three-zone in the goaf is divided into heat dissipation zone, oxidized spontaneous combustion zone, and suffocation zone. Simulations from the COMSOL Multiphysics 5.3 software provide insight based on the three zones division standard of spontaneous combustion in the goaf. The gradual deepening of the nitrogen injection position into the goaf affects the lower limit of the oxidized spontaneous combustion zone significantly, but the impact on the upper limit of the oxidized spontaneous combustion zone is not obvious and is negligible. With regard to the width of the oxidized spontaneous combustion zone, it initially decreases followed by a gradual increase. Numerical calculations suggest the optimal nitrogen injection position is 40 m from the roof cutting line, with an oxidized spontaneous combustion zone width of 28 m. Based on the simulation analysis results, nitrogen injection controlling measures have been adopted for spontaneous combustion of residual coal in the goaf of the 1303 fully mechanized coal caving faces, and coal self-ignition in the goaf has been successfully extinguished.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
By preparing a sensor system around isolated exceptional points, one can obtain a great enhancement of the sensitivity benefiting from the non‐Hermiticity. However, this comes at the cost of ...reduction of the flexibility of the system, which is critical for practical applications. By generalizing the exceptional points to exceptional surfaces, it has been theoretically proposed recently that enhanced sensitivity and flexibility can be combined. Here, an exceptional surface is experimentally demonstrated in a non‐Hermitian photonic sensing system, which is composed of a whispering‐gallery‐mode microresonator and two nanofiber waveguides, resulting in a unidirectional coupling between two degenerate counter‐propagating modes with an external optical isolator. The system is simple, robust, and can be easily operated around an exceptional surface. On the one hand, sensitivity enhancement is observed by monitoring the resonant frequency splitting caused by small perturbations. This demonstration of exceptional‐surface‐enhanced sensitivity paves the way for practical non‐Hermitian sensing applications. On the other hand, the suppression of frequency splitting around the exceptional surface is also shown for the first time.
Exceptional surfaces are experimentally realized in the higher‐dimensional synthetic space. The unidirectional coupling between two degenerate modes can be achieved benefitting from an ingenious design within a single whispering‐gallery‐mode microresonator. The sensor operating at an exceptional surface can combine enhanced sensitivity with flexible experimental conditions.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Following recent advances in osteoimmunology, there is growing recognition of the vital role of immune cells in the osteogenesis process. The 3D‐printed scaffold, as a substitute for injured and/or ...diseased bone tissues, has demonstrated satisfactory pro‐osteogenetic performance. However, whether immune cells prompt the above pro‐osteogenetic performance has not been elucidated in detail. In the present study, highly controllable Ti‐6Al‐4V scaffolds with different pore geometries were fabricated using a selective laser‐melting technique, to reveal their osteoimmunological functions with macrophages. The results showed that macrophages displayed characteristics of M2 phenotype in response to scaffolds. As a result, an anti‐inflammatory microenvironment was generated. When the pore geometry was considered, such observations were more apparent with the hexagonal pore scaffold than with the triangular one. In addition, inhibition of the toll‐like receptor signaling pathway in macrophages has been proposed to cause the above phenomenon. Upon applying conditioned media derived from macrophages on pre‐osteoblasts, the hexagonal pore scaffold group was found to significantly enhance osteoblastic differentiation, via macrophage‐to‐implant interactions. However, the effect of triangular pore scaffold was not statistically significant compared to that of hexagonal pore scaffolds or nonporous samples. In an attempt to quantify scaffold pore geometries, it was suggested that pores with higher circularity values tended to induce M2 polarization of macrophages, promote an anti‐inflammatory milieu, and therefore, achieve better osteogenetic performance via immunomodulation.
Selective laser‐melted scaffolds simulated macrophages to generate an anti‐inflammatory milieu compared to the nonporous samples (NPS), which further promoted pre‐osteoblasts (OBs) toward osteogenesis. This effect was more efficient with scaffolds of hexagon pores (HS, with a circulatory value of 0.85) than triangular pores (TS, with a circulatory value of 0.65).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We report herein a strategy to construct enantiopure inherently chiral macrocycles, ABCD-type heteracalix4aromatics, through a catalytic enantioselective intramolecular C–N bond forming reaction. A ...chiral ligand-palladium complex was found to efficiently induce the inherent chirality of molecules during the macrocyclization process with ee values up to >99%. The resulting ABCD-type heteracalix4aromatics displayed excellent and pH-triggered switchable electronic circular dichroism and circularly polarized luminescence properties.
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IJS, KILJ, NUK, PNG, UL, UM
Escherichia coli is the most widely used bacterium in prokaryotic expression system for the production of recombinant proteins. In BL21 (DE3), the gene encoding the T7 RNA polymerase (T7 RNAP) is ...under control of the strong lacUV5 promoter (P
), which is leakier and more active than wild-type lac promoter (P
) under certain growth conditions. These characteristics are not advantageous for the production of those recombinant proteins with toxic or growth-burdened. On the one hand, leakage expression of T7 RNAP leads to rapid production of target proteins under non-inducing period, which sucks resources away from cellular growth. Moreover, in non-inducing or inducing period, high expression of T7 RNAP production leads to the high-production of hard-to-express proteins, which may all lead to loss of the expression plasmid or the occurrence of mutations in the expressed gene. Therefore, more BL21 (DE3)-derived variant strains with rigorous expression and different expression level of T7 RNAP should be developed. Hence, we replaced P
with other inducible promoters respectively, including arabinose promoter (P
), rhamnose promoter (P
), tetracycline promoter (P
), in order to optimize the production of recombinant protein by regulating the transcription level and the leakage level of T7 RNAP. Compared with BL21 (DE3), the constructed engineered strains had higher sensitivity to inducers, among which rhamnose and tetracycline promoters had the lowest leakage ability. In the production of glucose dehydrogenase (GDH), a protein that causes host autolysis, the engineered strain BL21 (DE3::ara) exhibited higher biomass, cell survival rate and foreign protein expression level than that of BL21 (DE3). In addition, these engineered strains had been successfully applied to improve the production of membrane proteins, including E. coli cytosine transporter protein (CodB), the E. coli membrane protein insertase/foldase (YidC), and the E. coli F-ATPase subunit b (Ecb). The engineered strains constructed in this paper provided more host choices for the production of recombinant proteins.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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