This article introduces a novel ultrathin linear-to-circular polarization converter based on third-order meta-frequency selective surfaces (meta-FSS) that operates at the <inline-formula> <tex-math ...notation="LaTeX">X </tex-math></inline-formula>-band. The meta-FSS unit cell is composed of three metal layers and is separated by two dielectric substrates with a thickness of <inline-formula> <tex-math notation="LaTeX">\lambda _{0} </tex-math></inline-formula>/20 (<inline-formula> <tex-math notation="LaTeX">\lambda _{0} </tex-math></inline-formula> is the free space wavelength at 9.8 GHz). The transmission coefficients at two orthogonal directions are equal, while a 90° transmission phase difference is introduced between them over a wide bandwidth. A detailed procedure of equivalent circuit design has been developed for a better understanding of the operating principles. A horn antenna is employed as a linear source to verify the performance of the proposed structure. The measured results show that the designed meta-FSS can effectively convert a linear polarized (LP) wave to a left-hand circular polarized (LHCP) wave in the frequency range 9.1-10.82 GHz (approximately 17.5%) and to a right-hand circular polarized (RHCP) wave in the range 8.8-10.9 GHz (approximately 21.4%).
This aticle presents a new wideband omnidirectional array antenna that operates at Ku‐band. Each element of the array antenna consists of a modified planar bow‐tie dipoles radiator, a pair of ...parasitic strips, and a pair of directors. The parasitic strips and directors are designed to enhance the antenna omnidirectional radiating performance. All elements are combined through a double‐sided parallel strip‐line feeding network. A wideband semicircular balun is employed at the feeding port to broaden the impedance bandwidth. Finally, a 2 × 2 prototype is designed, fabricated, and measured. The measured results demonstrate that the proposed array antenna provides 47.3% (11.3‐18.4 GHz) relative impedance bandwidth with 4.1 dBi maximum gain, around 44.8° half‐power beamwidth at 15.0 GHz and less than 2.5 dB unroundness over the whole operating band in xoy plane.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this letter, a new dual linearly polarized rectenna using defected ground structure (DGS) is presented. The rectenna is designed on the low-cost FR-4 substrates with the size of <inline-formula> ...<tex-math notation="LaTeX">70 \times 70\,\,\text {mm}^{2} </tex-math></inline-formula> and works at 2.45 GHz. A high-order harmonic-rejection property is obtained and antenna miniaturization is realized at the same time by using the DGS. The rectifier's maximum efficiency can be up to 83.7% when the input power is equal to 22.5 dBm. The efficiency for various polarization tilt angles can always be higher than 72.0% under the condition of the input power of 22.5 dBm.
Increased neoantigens in hypermutated cancers with DNA mismatch repair deficiency (dMMR) are proposed as the major contributor to the high objective response rate in anti-PD-1 therapy. However, the ...mechanism of drug resistance is not fully understood. Using tumor models defective in the MMR gene Mlh1 (dMLH1), we show that dMLH1 tumor cells accumulate cytosolic DNA and produce IFN-β in a cGAS-STING-dependent manner, which renders dMLH1 tumors slowly progressive and highly sensitive to checkpoint blockade. In neoantigen-fixed models, dMLH1 tumors potently induce T cell priming and lose resistance to checkpoint therapy independent of tumor mutational burden. Accordingly, loss of STING or cGAS in tumor cells decreases tumor infiltration of T cells and endows resistance to checkpoint blockade. Clinically, downregulation of cGAS/STING in human dMMR cancers correlates with poor prognosis. We conclude that DNA sensing within tumor cells is essential for dMMR-triggered anti-tumor immunity. This study provides new mechanisms and biomarkers for anti-dMMR-cancer immunotherapy.
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•dMLH1 tumor cells accumulate cytosolic DNA and produce IFN-β•Knockout of cGAS or STING in dMLH tumor cells renders resistance to checkpoint blockade•Downregulating cGAS-STING in human dMLH1 cancers impairs checkpoint blockade therapy
About 50% of patients with dMMR cancers are objectively responsive to immunotherapy. In addition to neoantigens, Lu et al. find that dMMR-mediated cytosolic DNA sensing by cGAS-STING pathway in tumor cells contributes to such clinical benefits, while impaired expression of cGAS-STING pathway is associated with drug resistance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
High-frequency point mutations of genes encoding histones have been identified recently as novel drivers in a number of tumors. Specifically, the H3K36M/I mutations were shown to be oncogenic in ...chondroblastomas and undifferentiated sarcomas by inhibiting H3K36 methyltransferases, including SETD2. Here we report the crystal structures of the SETD2 catalytic domain bound to H3K36M or H3K36I peptides with SAH (S-adenosylhomocysteine). In the complex structure, the catalytic domain adopts an open conformation, with the K36M/I peptide snuggly positioned in a newly formed substrate channel. Our structural and biochemical data reveal the molecular basis underying oncohistone recognition by and inhibition of SETD2.
Somatic mutations on glycine 34 of histone H3 (H3G34) cause pediatric cancers, but the underlying oncogenic mechanism remains unknown. We demonstrate that substituting H3G34 with arginine, valine, or ...aspartate (H3G34R/V/D), which converts the non-side chain glycine to a large side chain-containing residue, blocks H3 lysine 36 (H3K36) dimethylation and trimethylation by histone methyltransferases, including SETD2, an H3K36-specific trimethyltransferase. Our structural analysis reveals that the H3 “G33-G34” motif is recognized by a narrow substrate channel, and that H3G34/R/V/D mutations impair the catalytic activity of SETD2 due to steric clashes that impede optimal SETD2–H3K36 interaction. H3G34R/V/D mutations also block H3K36me3 from interacting with mismatch repair (MMR) protein MutSα, preventing the recruitment of the MMR machinery to chromatin. Cells harboring H3G34R/V/D mutations display a mutator phenotype similar to that observed in MMR-defective cells. Therefore, H3G34R/V/D mutations promote genome instability and tumorigenesis by inhibiting MMR activity.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Summary
Heterotrophic nitrifiers are able to oxidize and remove ammonia from nitrogen‐rich wastewaters but the genetic elements of heterotrophic ammonia oxidation are poorly understood. Here, we ...isolated and identified a novel heterotrophic nitrifier, Alcaligenes ammonioxydans sp. nov. strain HO‐1, oxidizing ammonia to hydroxylamine and ending in the production of N2 gas. Genome analysis revealed that strain HO‐1 encoded a complete denitrification pathway but lacks any genes coding for homologous to known ammonia monooxygenases or hydroxylamine oxidoreductases. Our results demonstrated strain HO‐1 denitrified nitrite (not nitrate) to N2 and N2O at anaerobic and aerobic conditions respectively. Further experiments demonstrated that inhibition of aerobic denitrification did not stop ammonia oxidation and N2 production. A gene cluster (dnfT1RT2ABCD) was cloned from strain HO‐1 and enabled E. coli accumulated hydroxylamine. Sub‐cloning showed that genetic cluster dnfAB or dnfABC already enabled E. coli cells to produce hydroxylamine and further to 15N2 from (15NH4)2SO4. Transcriptome analysis revealed these three genes dnfA, dnfB and dnfC were significantly upregulated in response to ammonia stimulation. Taken together, we concluded that strain HO‐1 has a novel dnf genetic cluster for ammonia oxidation and this dnf genetic cluster encoded a previously unknown pathway of direct ammonia oxidation (Dirammox) to N2.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
•A new aerobic denitrifier, named NNA5, was isolated, identified as Marinobacter sp.•Strain NNA5 could perform only aerobic denitrification but not nitrification.•Aerobic denitrification was ...efficient with NO3−-N removal rate of 112.8mg/L/d.•The aerobic denitrifying product of strain NNA5 is N2 while no N2O emission.
An efficient aerobic denitrification bacterium, strain NNA5, was isolated and identified as Marinobacter sp. NNA5. NNA5 did not perform heterotrophic nitrification. GC/IRMS analysis revealed that 15N2 was produced from Na15NO2 and K15NO3. GC/MS and quantitative analyses showed that no N2O emission occurred when nitrite or nitrate was used as substrate. Single factor experiments indicated that optimal conditions for aerobic denitrification were: sodium succinate or sodium pyruvate as carbon source, temperature 35°C, NaCl concentration 2–4%, C/N ratio 6–8, pH 7.5, rotation speed 150rpm (giving dissolved oxygen concentration 6.08mg/L), NO3−-N concentration ranging from 140 to 700mg/L. NNA5 displayed highly efficient aerobic denitrifying ability, with maximal NO3−-N removal rate 112.8mg/L/d. In view of its ability to perform aerobic denitrification with zero N2O emission, NNA5 has great potential for future application in aerobic denitrification processes in industrial and aquaculture wastewater treatment systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
► Heterotrophic nitrification–aerobic denitrification of Bacillus methylotrophicus. ► Transform NH3 to N2O and NO2- to N2 for G+ bacteria were never described. ► Nitrite other than nitrate was ...employed as denitrification substrate. ► GC–MS and GC–IRMS revealed a different gaseous nitrogen compound emitting pattern.
Bacillus methylotrophicus strain L7, exhibited efficient heterotrophic nitrification–aerobic denitrification ability, with maximum NH4+-N and NO2--N removal rate of 51.58mg/L/d and 5.81mg/L/d, respectively. Strain L7 showed different gaseous emitting patterns from those strains ever described. When 15NH4Cl, or Na15NO2, or K15NO3 was used, results of GC–MS indicated that N2O was emitted as the intermediate of heterotrophic nitrification or aerobic denitrification, while GC–IRMS results showed that N2 was produced as end product when nitrite was used. Single factor experiments suggested that the optimal conditions for heterotrophic nitrification were sodium succinate as carbon source, C/N 6, pH 7–8, 0g/L NaCl, 37°C and a wide range of NH4+-N from 80 to 1000mg/L. Orthogonal tests showed that the optimal conditions for aerobic denitrification were C/N 20, pH 7–8, 10g/L NaCl and DO 4.82mg/L (shaking speed 50r/min) when nitrite was served as substrate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Calcium ferrite containing aluminum (CFA) is a precursor of the low-temperature bonding phase in the sintering process of iron ore fines for blast furnace ironmaking. Thus, improving the formation of ...CFA at lower temperature is very important for saving energy, improving efficiency and production. In this paper, the formation process of CFA was investigated at 1200 °C by reactions of alumina (Al2O3), respectively with a mixture of calcium oxide (CaO) and hematite (Fe2O3) and monocalcium ferrite (CF) as a recognized initial product, as well as reaction of Al-containing hematite (Hss) with CF. The result confirmed that CF is an intermediate product formed easily in the sintering process, and it may react with excessive Fe2O3 to generate an alpha-calcium iron oxide (Ca2Fe15.50O25) as a new phase. It was found that CFA can be formed directly by reactions of CF with Hss and Ca2Fe15.50O25 with Al2O3, while the reaction of CF with Al2O3 is more helpful in generating Ca2Fe15.5O25 rather than CFA, simultaneously forming a calcium aluminum oxide (CaAl2O4, CA; CaAl4O7, CA2). It was revealed that the appearance of CA and CA2 is a main reason to hinder CFA formation in the sintering process of iron ore fines.
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CEKLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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