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A series of successes in RNA interference (RNAi) therapies for liver diseases using lipid nanoparticles and N -acetylgalactosamine have heralded a current era of RNA therapeutics. However, alternative delivery strategies are required to take RNAi out of the comfort zone of hepatocytes. Here we report SIRPα IgV/anti-CD47 siRNA (vS-siCD47) conjugates that selectively and persistently disrupt the antiphagocytic CD47/SIRPα axis in solid tumors. Conjugation of the SIRPα IgV domain protein to siRNAs enables tumor dash through CD47-mediated erythrocyte piggyback, primarily blocking the physical interaction between CD47 on cancer cells and SIRPα on phagocytes. After internalization of the vS-siCD47 conjugates within cancer cells, the detached free-standing anti-CD47 siRNAs subsequently attack CD47 through the RNAi mechanism. The dual-action approach of the vS-siCD47 conjugate effectively overcomes the "don't eat me" barrier and stimulates phagocyte-mediated tumor destruction, demonstrating a highly selective and potent CD47-blocking immunotherapy. This delivery strategy, employing IgV domain protein-siRNA conjugates with a dual mode of target suppression, holds promise for expanding RNAi applications beyond hepatocytes and advancing RNAi-based cancer immunotherapies for solid tumors.

A targeted and logical discovery method was devised for natural products containing piperazic acid (Piz), which is biosynthesized from ornithine by l-ornithine N -hydroxylase (KtzI) and N - N bond formation enzyme (KtzT). Genomic signature-based screening of a bacterial DNA library (2020 strains) using polymerase chain reaction (PCR) primers targeting ktzT identified 62 strains (3.1%). The PCR amplicons of KtzT-encoding genes were phylogenetically analyzed to classify the 23 clades into two monophyletic groups, I and II. Cultivating hit strains in media supplemented with 15 NH 4 Cl and applying 1 H- 15 N heteronuclear multiple bond correlation (HMBC) along with 1 H- 15 N heteronuclear single quantum coherence (HSQC) and 1 H- 15 N HSQC-total correlation spectroscopy (HSQC-TOCSY) NMR experiments detected the spectroscopic signatures of Piz and modified Piz. Chemical investigation of the hit strains prioritized by genomic and spectroscopic signatures led to the identification of a new azinothricin congener, polyoxyperuin B seco acid ( 1 ), previously reported chloptosin ( 2 ) in group I, depsidomycin D ( 3 ) incorporating two dehydropiperazic acids (Dpz), and lenziamides A and B ( 4 and 5 ), structurally novel 31-membered cyclic decapeptides in group II. By consolidating the phylogenetic and chemical analyses, clade-structure relationships were elucidated for 19 of the 23 clades. Lenziamide A ( 4 ) inhibited STAT3 activation and induced G 2 /M cell cycle arrest, apoptotic cell death, and tumor growth suppression in human colorectal cancer cells. Moreover, lenziamide A ( 4 ) resensitized 5-fluorouracil (5-FU) activity in both in vitro cell cultures and the in vivo 5-FU-resistant tumor xenograft mouse model. This work demonstrates that the genomic and spectroscopic signature-based searches provide an efficient and general strategy for new bioactive natural products containing specific structural motifs.

The logical and effective discovery of macrolactams, structurally unique natural molecules with diverse biological activities, has been limited by a lack of targeted search methods. Herein, a targeted discovery method for natural macrolactams was devised by coupling genomic signature-based PCR screening of a bacterial DNA library with spectroscopic signature-based early identification of macrolactams. DNA library screening facilitated the efficient selection of 43 potential macrolactam-producing strains (3.6% of 1,188 strains screened). The PCR amplicons of the amine-deprotecting enzyme-coding genes were analyzed to predict the macrolactam type (α-methyl, α-alkyl, or β-methyl) produced by the hit strains. 1 H- 15 N HSQC-TOCSY NMR analysis of 15 N-labeled culture extracts enabled macrolactam detection and structural type assignment without any purification steps. This method identified a high-titer Micromonospora strain producing salinilactam ( 1 ), a previously reported α-methyl macrolactam, and two Streptomyces strains producing new α-alkyl and β-methyl macrolactams. Subsequent purification and spectroscopic analysis led to the structural revision of 1 and the discovery of muanlactam ( 2 ), an α-alkyl macrolactam with diene amide and tetraene chromophores, and concolactam ( 3 ), a β-methyl macrolactam with a [16,6,6]-tricyclic skeleton. Detailed genomic analysis of the strains producing 1 - 3 identified putative biosynthetic gene clusters and pathways. Compound 2 displayed significant cytotoxicity against various cancer cell lines (IC 50 = 1.58 μM against HCT116), whereas 3 showed inhibitory activity against Staphylococcus aureus sortase A. This genomic and spectroscopic signature-based method provides an efficient search strategy for new natural macrolactams and will be generally applicable for the discovery of nitrogen-bearing natural products.

Three isoindolinone alkaloids ( 1 - 3 ), including one new isoindolinone-type alkaloid, meyeroguilline E ( 1 ), and six other known compounds ( 4 - 9 ) were isolated from the poisonous mushroom Chlorophyllum molybdites (Agaricaceae). The structure of the new compound was determined using extensive spectroscopic analyses via one-dimensional (1D) and two-dimensional (2D) NMR data interpretation and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). To the best of our knowledge, compound 1 is the first example of a natural isoindolinone with a butanoic acid moiety, and this study is the first to detect the other known compounds ( 2 - 9 ) in C. molybdites . The isolated compounds ( 1 - 9 ) were examined for their multidrug resistance (MDR) reversal activity against MES-SA, MES-SA/DX5, HCT15, and HCT15/CL02 human cancer cells. Based on the results, 20 μM of compounds 3 and 6 slightly potentiated paclitaxel (TAX)-induced cytotoxicity in MES-SA/DX5, HCT15, and HCT15/CL02 cells; however, the compounds had no effect on the cytotoxicity against MES-SA and nonMDR cells., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

This work shows that hydroboration can be efficiently applied to the postsynthetic modification (PSM) of the Sonogashira-Hagihara coupling-based microporous organic polymers (MOPs). Hollow MOPs (H-MOPs) were prepared by template synthesis through the Sonogashira-Hagihara coupling of tetra(4-ethynylphenyl)methane with 1,4-diiodobenzene. The H-MOPs were used as platforms in the PSM-based functionalization. The heat-treatment of H-MOPs in the presence of a neat pinacolborane reagent resulted in the successful addition of pinacolborane groups to the internal alkynes of H-MOPs, generating H-MOPs with pinacolboranes (H-MOP-BPs). The pinacolborane moieties in the H-MOP-BP were further converted to boronic acid groups. The resultant H-MOP-BAs were used as heterogeneous organocatalysts in the CO 2 fixation with epoxides to cyclic carbonates at ambient temperature (50 °C). Moreover, H-MOP-BAs could be recycled with retention of the catalytic performance in five successive reactions.

The fruit of Tetradium ruticarpum , known as Evodiae Fructus, is a traditional herbal medicine used to treat gastric and duodenal ulcers, vomiting, and diarrhea. The traditional usage can be potentially associated with the antibacterial activity of T. ruticarpum fruits against Helicobacter pylori . However, so far, the antibacterial activity of T. ruticarpum fruits and antibacterial components against H. pylori has not been investigated despite the traditional folk use. The current study was conducted to investigate the bioactive chemical components of T. ruticarpum fruits and evaluate their antibacterial activity against H. pylori . Phytochemical investigation of the EtOH extract of T. ruticarpum fruits led to the isolation and identification of nine compounds ( 1 - 9 ), including phellolactone ( 1 ), the absolute configuration of which has not yet been determined. The chemical structures of the isolated compounds were elucidated by analyzing the spectroscopic data from one-dimensional (1D) and two-dimensional (2D) NMR and high-resolution electrospray ionization mass spectrometry (HR-ESIMS) experiments. Specifically, the absolute configuration of compound 1 was established by the application of computational methods, including electronic circular dichroism (ECD) calculation and the NOE/ROE-based interproton distance measurement technique via peak amplitude normalization for the improved cross-relaxation (PANIC) method. In the anti- H. pylori activity test, compound 3 showed the most potent antibacterial activity against H. pylori strain 51, with 94.4% inhibition (MIC 50 and MIC 90 values of 22 and 50 μM, respectively), comparable to that of metronidazole (97.0% inhibition, and MIC 50 and MIC 90 values of 17 and 46 μM, respectively). Moreover, compound 5 exhibited moderate antibacterial activity against H. pylori strain 51, with 58.6% inhibition (MIC 50 value of 99 μM), which was higher than that of quercetin (34.4% inhibition) as a positive control. Based on the bioactivity results, we also analyzed the structure-activity relationship of the anti- H. pylori activity. Conclusion: These findings demonstrated that T. ruticarpum fruits had antibacterial activity against H. pylori and could be used in the treatment of gastric and duodenal ulcers. Meanwhile, the active compound, 1-methyl-2-(8 E )-8-tridecenyl-4(1 H )-quinolinone ( 3 ), identified herein also indicated the potential application in the development of novel antibiotics against H. pylori ., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

l-Ergothioneine (EGT) is a strong antioxidant used in industry, and it is commonly extracted from mushrooms; however, its production is limited. As an alternative, we developed metabolically engineered Corynebacterium glutamicum with reinforced sulfur assimilation and pentose phosphate pathways, which led to the accumulation of 45.0 and 63.2 mg/L EGT, respectively. Additionally, the overexpression of cysEKR resulted in further promoted EGT production in ET4 (66.5 mg/L) and ET7 (85.0 mg/L). Based on this result, we developed the strain ET11, in which all sulfur assimilatory, PP, and l-cysteine synthetic pathways were reinforced, and it synthesized 264.4 mg/L EGT. This study presents the first strategy for EGT synthesis that does not require precursor addition in C. glutamicum , and the production time was shortened. In addition, the synthesized EGT showed high radical scavenging activity (70.7%), thus confirming its antioxidant function. Consequently, this study showed the possibility of EGT commercialization by overcoming the limitations of industrial processes.

Metabolic engineering of non-photosynthetic microorganisms to increase the utilization of CO 2 has been focused on as a green strategy to convert CO 2 into valuable products such as fatty acids. In this study, a CO 2 utilization pathway involving carbonic anhydrase and biotin carboxylase was formed to recycle CO 2 in the oleaginous yeast Yarrowia lipolytica , thereby increasing the production of fatty acids. In the recombinant strain in which the CO 2 utilization pathway was introduced, the production of fatty acids was 10.7 g/L, which was 1.5-fold higher than that of the wild-type strain. The resulting strain had a 1.4-fold increase in dry cell mass compared to the wild-type strain. In addition, linoleic acid was 47.7% in the fatty acid composition of the final strain, which was increased by 11.6% compared to the wild-type strain. These results can be applied as an essential technology for developing efficient and eco-friendly processes by directly utilizing CO 2 .

The anion radical of the 2'-deoxyadenosine···thymine (dAT •- ) pair has been investigated experimentally and theoretically in the gas phase. By employing negative-ion photoelectron spectroscopy (PES), we have registered a spectrum typical for the valence-bound anion, featuring a broad peak at the electron-binding energy (EBE) between ∼1.5 and 2.2 eV with the maximum at ∼1.9 eV. The measured value of the adiabatic electron affinity (AEA) for dAT was estimated to be ∼1.1 eV. Calculations performed at the M06-2X/6-31++G(d,p) level revealed that the structure, where thymine is coordinated to the sugar of dA by two hydrogen bonds, is responsible for the observed PES signal. The AEA G and the vertical detachment energy of 0.91 and 1.68 eV, respectively, calculated for this structure reproduce the experimental values well. The role of the possible proton transfer in the stabilization of anionic radical complexes is discussed.

(-)-α-Bisabolol is a functional ingredient in various health and cosmetic products and has antibacterial, anti-inflammatory, and wound healing properties. (-)-α-Bisabolol is chemically synthesized and produced by steam distillation of essential oils extracted from Brazilian Candeia ( Eremanthus erythropappus ). To sustainably produce pure (-)-α-bisabolol, we previously engineered Escherichia coli to produce 9.1 g/L (-)-α-bisabolol via heterologous mevalonate pathways and (-)-α-bisabolol synthase (BOS) from German chamomile, Matricaria recutita (MrBOS). BOS has only been reported in MrBOS and Brazilian Candeia (EeBOS). The limited availability of BOS has made it difficult to achieve high titer and yield and large-scale (-)-α-bisabolol production. We identified a novel BOS in globe artichoke (CcBOS) and examined its functionality in vitro and in vivo . CcBOS showed higher catalytic efficiency and (-)-α-bisabolol production rates than those from MrBOS or EeBOS. In fed-batch fermentation, CcBOS generated the highest reported (-)-α-bisabolol titer to date (23.4 g/L). These results may facilitate economically viable industrial (-)-α-bisabolol production.

Biobased processes to minimize environmental pollutants have attracted much attention. l-Carnosine has been produced by chemical synthesis, and as an alternative to this method, we newly developed engineered Corynebacterium glutamicum synthesizing l-carnosine. To develop the strain, the pentose phosphate pathway (PPP) was enhanced by attenuating flux to nonoxidative PPP. Enhanced PPP strengthened the histidine pathway and produced 5.0 g/L l-histidine and 3.9 mg/L l-carnosine. Then, the histidine synthetic pathway was reinforced by overexpressing HisG and Rel. This pathway reduced feedback inhibition by l-histidine and strengthened the flux of the histidine pathway; thus, it produced 552.20 mg/g DCW l-histidine. As a result, enhancement of the PPP accumulates more l-histidine than the histidine pathway; thus, the PPP was further enhanced by pgi gene alteration. For sufficient β-alanine products, PanD was overexpressed and produced 99.17 mg/L l-carnosine. The final strain, Car15, which consolidated all three pathways, produced 323.26 mg/L l-carnosine via fed-batch fermentation. Finally, we confirmed the antioxidant and antiglycation effects of biologically synthesized l-carnosine, and the biologically synthesized l-carnosine showed inhibitory activity similar to that of commercial l-carnosine. Consequently, this study suggested a new biosynthetic process for l-carnosine and showed potential as a treatment for metabolic disorders through the assessment of its functions.

Iron immobilized on supports such as silica, alumina, titanium oxide, and zeolite can activate hydrogen peroxide (H 2 O 2 ) into strong oxidants. However, the role of the support and the nature of the oxidants produced in this process remain elusive. This study investigated the activation of H 2 O 2 by a TiO 2 -supported catalyst (FeTi-ox). Characterizing the catalyst surface in situ using X-ray absorption spectroscopy (XAS), together with X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR), revealed that the interaction between H 2 O 2 and the TiO 2 phase played a key role in the H 2 O 2 activation. This interaction generated a stable peroxo-titania ≡Fe(III)-Ti-OOH complex, which reacted further with H 2 O to produce a surface oxidant, likely ≡Fe[IV] ═ O 2+ . The oxidant effectively degraded acetaminophen, even in the presence of chloride, bicarbonate, and organic matter. Unexpectedly, contaminant oxidation continued after the H 2 O 2 in the solution was depleted, owing to the decomposition of ≡Fe(III)-Ti-OOH by water. In addition, the FeTi-ox catalyst effectively degraded acetaminophen over five testing cycles. Overall, new insights gained in this study may provide a basis for designing more effective catalysts for H 2 O 2 activation.

Multifunctional drug delivery systems were designed and engineered by template synthesis of a microporous organic polymer (MOP) and by postsynthetic modification. Hollow MOP spheres bearing Fe 3 O 4 yolks (Fe 3 O 4 @Void@MOP) were prepared by the synthesis of MOP on Fe 3 O 4 @SiO 2 nanoparticles and by successive silica etching. In addition to the magneto-thermal function of Fe 3 O 4 yolks, an aggregation-induced emission (AIE) feature was incorporated into the Fe 3 O 4 @Void@MOP through a homocoupling of tetra(4-ethynylphenyl)ethylene to form Fe 3 O 4 @Void@MOP-TE. Folate groups were further introduced into Fe 3 O 4 @Void@MOP-TE through the postsynthetic modification based on the thiol-yne click reaction. The resultant Fe 3 O 4 @Void@MOP-TE-FA showed multifunctionality in antitumoral therapy via folate receptor targeting, doxorubicin delivery, AIE-based imaging, and the magneto-thermal feature.

Flexible and metal-economical electromagnetic interference (EMI) shielding films were fabricated based on microporous organic polymer (MOP) chemistry. MOP with amino groups (MOP-A) could be introduced to the surface of poly(ethylene terephthalate) (PET) fibers. Due to the microporosity and amino groups of MOP-A, Ag + could be easily incorporated into PET@MOP-A. Through Ag-catalyzed electroless Cu deposition, PET@MOP-A@Cu films were fabricated. The morphological and chemical structures of the PET@MOP-A@Cu were characterized by scanning electron microscopy, X-ray diffraction studies, and X-ray photoelectron spectroscopy. Among the films, the PET@MOP-A@Cu-40 with 41 wt % Cu (a thickness of 0.64 μm) showed excellent EMI shielding performance with 64.3-73.8 dB against an EM of 8-12 GHz. Moreover, it showed retention of the original EMI shielding performance against 1000 bending ( R = 5 mm) tests.

AMP-activated protein kinase (AMPK in human and AAK in C. elegans ) is a master regulator of metabolism. It has many isotypes, but its isotype-dependent functions are largely unknown. By developing real-time in-organism NMR metabolomics for C. elegans , we were able to study different roles of the isotypic catalytic subunits of AAK/AMPK, AAK-1, and AAK-2 in live worms at the whole organism level. The aak-1 knockout animals exhibited enhanced glucose production under starvation, strikingly opposite to aak-2 knockout animals. Unusually high compensatory expression of the reciprocal isotypes in each KO strain and the results for the double KO animals suggested an unconventional phenotype-genotype relationship and the dominance of aak-2 in glucose production. The gene expression patterns showed that the differential phenotypes of aak-1 KO strain are due to reduced TCA and glycolysis and enhanced gluconeogenesis compared to the aak-2 KO strain. Subsequent 13 C-isotope incorporation experiment showed that the glucose production in aak-1 KO occurs through the activation of fatty acid oxidation and glyoxylate shunt. Revealing differential roles of the isotypes of AAK/AMPK, our convenient approach is readily applicable to many C. elegans models for human metabolic diseases.

This work shows that the shape-controlled microporous organic polymer (MOP) can be utilized for the morphological engineering of another class of MOP materials. The morphology of a hyper-cross-linked polymer (HCP) was successfully engineered on the hollow conjugated microporous polymer (CMP). Through the postsynthetic modification of HCP bearing BINOLs (HCP-B) on the hollow CMP-like material (H-CMPL), the HCP bearing BINOL phosphoric acid (HCP-BP) was engineered on the H-CMPL platform. The resultant H-CMPL@HCP-BP showed good catalytic performance as a heterogeneous catalytic system and excellent recyclability in the ring-opening polymerization of ε-caprolactones to poly(caprolactone).

Plant oxylipins, including hydroxy fatty acids, epoxy hydroxy fatty acids, and trihydroxy fatty acids, which are biosynthesized from C18 polyunsaturated fatty acids (PUFAs), are involved in pathogen-specific defense mechanisms against fungal infections. However, their quantitative biotransformation by plant enzymes has not been reported. A few bacteria produce C18 trihydroxy fatty acids, but the enzymes and pathways related to the biosynthesis of plant oxylipins in bacteria have not been reported. In this study, we first report the biotransformation of C18 PUFAs into plant C18 oxylipins by expressing linoleate 9 S-lipoxygenase with and without epoxide hydrolase from the proteobacterium Myxococcus xanthus in recombinant Escherichia coli. Among the nine types of plant oxylipins, 12,13-epoxy-14-hydroxy- cis, cis-9,15-octadecadienoic acid was identified as a new compound by NMR analysis, and 9,10,11-hydroxy- cis, cis-6,12-octadecadienoic acid and 12,13,14-trihydroxy- cis, cis-9,15-octadecadienoic were suggested as new compounds by LC-MS/MS analysis. This study shows that bioactive plant oxylipins can be produced by microbial enzymes.

The Platycodon grandiflorum root, Platycodi radix, a common vegetable, and its extract with glycosylated saponins, platycosides, have been used as food items and food health supplements for pulmonary diseases and respiratory disorders. Enzymes convert glycosylated saponins into deglycosylated saponins, which exhibit higher biological activity than glycosylated saponins. In this study, β-glucosidase from the hyperthermophilic bacterium Dictyoglomus turgidum converted platycosides in the Platycodi radix extract into deglucosylated platycosides. In addition, the enzyme completely converted platycoside E (PE), platycodin D 3 (PD 3 ), and platycodin D (PD) in Platycodi radix extract into deglucosylated platycodin D (deglu PD), which was first identified by nuclear magnetic resonance. The anti-inflammatory activities of deglu PD and deglucosylated Platycodi radix extract were higher than those of PE, PD 3 , PD, Platycodi radix extract, and baicalein, an anti-inflammatory agent. Therefore, deglucosylated Platycodi radix extract is expected to be used as improved functional food supplements.

This work shows that the surface properties of polyurethane acrylate (PUA) films can be controlled by the coating of nanoporous organic networks (NONs). By the NON coating, the hydrophilic nature of nanostructured PUA (N-PUA) film was converted to superhydrophobic surface. The NON-coated N-PUA films (N-PUA-NONs) were applied as stationary adsorbents for the capture of particulate matter (PM) in air. Compared with the original PUA films, the N-PUA-NON films showed much enhanced capture performance toward PM and recyclability through water washing, indicating the potential of outdoor application as stationary self-cleaning adsorbents under natural surroundings.

Taurine is a biologically and physiologically valuable food additive. However, commercial taurine production mainly relies on environmentally harmful chemical synthesis. Herein, for the first time in bacteria, we attempted to produce taurine in metabolically engineered Corynebacterium glutamicum. The taurine-producing strain was developed by introducing cs, cdo1, and csad genes. Interestingly, while the control strain could not produce taurine, the engineered strains successfully produced taurine via the newly introduced metabolic pathway. Furthermore, we investigated the effect of a deletion strain of the transcriptional repressor McbR gene on taurine production. As a result, sulfur accumulation and l-cysteine biosynthesis were reinforced by the McbR deletion strain, which further increased the taurine production by 2.3-fold. Taurine production of the final engineered strain Tau11 was higher than in other previously reported strains. This study demonstrated a potential approach for eco-friendly biosynthesis as an alternative to the chemical synthesis of a food additive.

This work introduces a new efficient method for the postsynthetic modification of conjugated microporous polymers (CMPs). Osmium catalysis of hollow CMP (H-CMP) in the presence of NaClO 3 resulted in the conversion of alkynes in the skeleton of CMPs to dicarbonyl groups to form H-CMP-DC. Through controlling the reaction time, the carbonylation degree of H-CMP could be managed, maintaining hollow morphology. We verified the benefits of carbonyl groups in H-CMP-DC in the removal of Cr(VI) from water. Imination of H-CMP-DC resulted in amine-rich H-CMP (H-CMP-A), which showed enhanced adsorption performance toward Cr(VI) in water with q max up to 73 mg/g, compared with the H-CMP and H-CMP-DC. The H-CMP-A could be recycled at least five times, maintaining its original adsorption ability.

Microporous organic polymer nanoparticles bearing tetraphenylethylene moieties (MOPTs) were prepared in the presence of poly(vinylpyrrolidone) (PVP). The PVP was entrapped into the microporous network of MOPT to form MOPT-P and played the roles of size control, porosity enhancement, and surface property management. MOPT materials without PVP showed superhydrophobicity with a water contact angle of 151°. In comparison, the MOPT-P showed excellent water compatibility. Moreover, due to the aggregation-induced emission property of tetraphenylethylene moieties, the MOPT-P showed emission and excellent emission-based sensing of nitrophenols in water with K sv values in the range of 1.26 × 10 4 ∼ 3.37 × 10 4 M -1 . It is noteworthy that the MOPT-P used water only as a sensing medium and did not require additional organic solvents to enhance water dispersibility of materials. The MOPT-P could be recovered and reused for the sensing at least five times.

This work shows that the functions of microporous organic network materials can be enhanced through engineering of the material structure. Mimicking the surface structure of velvet worms, we prepared the aligned 1D structure (rod) of microporous porphyrin networks by the Sonogashira coupling of tetrakis(4-ethynylphenyl)porphyrin with 1,4-diiodobenzene in an anodic aluminum oxide plate. The length of the 1D structure was controlled in the range of 1-5 μm. The velvet worm surface-like microporous porphyrin networks (Velvet-MPNs) showed higher sensitivities to hydrogen chloride and ammonia gases by up to ∼14 and 4.6 times, respectively, compared with a control MPN material without rods.

Yolk-shell-type polystyrene@microporous organic network (Y-PS@MON) materials were prepared by the Sonogashira coupling of tetra(4-ethynylphenyl)methane and 1,4-diiodobenzene on the surface of PS@SiO 2 and by the etching of SiO 2 . The diameter of PS yolk spheres and the thickness of MON shells were 150 and ∼10 nm, respectively. The thickness of the void space between the PS yolk and the MON shell was ∼30 nm. Y-PS@MONs were used as templates for the synthesis of MoS 2 /C composite materials. Because of the microporosity of the MON shells and the void space between the yolk and the shell, MoS 2 precursor compounds were efficiently incorporated into Y-PS@MONs. The heat treatment under argon resulted in the formation of hollow MoS 2 /C composites. The contents of MoS 2 in the composites were systematically controlled by changing the amounts of precursor. MoS 2 /C with 58 wt % of MoS 2 showed the best energy storage performance with a capacitance of 418 F/g at a 0.5 A/g current density as an electrode material of a coin cell supercapacitor, which is attributable to its hollow structure, high surface area, and the good distribution of the sliced MoS 2 in the carbon matrix. Also, the MoS 2 /C-58 composite showed excellent retention of capacitances during 5000 cycles., Competing Interests: The authors declare no competing financial interest.

Poly(ethylene terephthalate) fibers (PET-Fs) were coated with microporous organic networks (MONs) by the Sonogashira coupling of tetra(4-ethynylphenyl)methane with 1,4-diiodobenzene. Ni was deposited on the PET-F@MON via electroless deposition. Interestingly, although Ni on the PET-F showed a sharp decrease in conductivity in repeated bending tests, the PET-F@MON@Ni showed excellent retention of conductivity. We suggest that thin MON layers play roles of an efficient binder for Ni attachment to fibers and a structural buffer for the relaxation of bending strain. The positive effect of MON was supported by scanning electron microscopy studies of the PET-F@Ni or PET-F@MON@Ni retrieved after 2000 bending numbers. Although Ni on the PET-F showed severe detachment after bending tests, PET-F@MON@Ni retained the original morphologies. The pouch cells of lithium-ion batteries fabricated using PET-F@MON@Ni as the current collectors showed excellent performance against bending.

Isotopomer analysis using either 13 C NMR or LC/GC-MS has been an invaluable tool for studying metabolic activities in a variety of systems. Traditional challenges are, however, that 13 C-detected NMR is insensitive despite its high resolution, and that MS-based techniques cannot easily differentiate positional isotopomers. In addition, current 13 C NMR or LC/GC-MS has limitations in detecting metabolites in living cells. Here, we describe a non-uniform sampling-based 2D heteronuclear single quantum coherence (NUS HSQC) approach to measure metabolic isotopomers in both cell lysates and living cells. The method provides a high resolution that can resolve multiplet structures in the 13 C dimension while retaining the sensitivity of the 1 H-indirect detection. The approach was tested in L1210 mouse leukemia cells labeled with 13 C acetate by measuring NUS HSQC with 25% sampling density. The results gave a variety of metabolic information such as (1) higher usage of acetate in acetylation pathway than aspartate synthesis, (2) TCA cycle efficiency changes upon the inhibition of mitochondrial oxidative phosphorylation by pharmacological agents, and (3) position-dependent isotopomer patterns in fatty acids in living cells. In addition, we were able to detect fatty acids along with other hydrophilic molecules in one sample of live cells without extraction. Overall, the high sensitivity and resolution along with the application to live cells should make the NUS HSQC approach attractive in studying carbon flux information in metabolic studies.

The reactor fouling is a notorious obstacle in managing continuous synthetic processes of polyketones. The fouling raises synthetic costs and reduces the bulk density of polymers. Thus, efficient seed materials are required for antifouling performance. Hollow microporous organic polymers (HMOPs) were prepared using ZIF-8 nanoparticles as templating materials. Sulfonic groups were incorporated into HMOP via a post synthetic approach. The resultant HMOP-SO 3 H (20-90 μg/mL in methanol) showed successful catalyst activation and antifouling performance in polyketone synthesis.

The 2'-deoxyadenosine···2'-deoxythymidine (dAdT(•-)) radical anion nucleoside pair has been investigated both experimentally and theoretically in the gas phase. The vertical detachment energy (VDE) and adiabatic electron affinity (AEA) were determined by anion photoelectron spectroscopy (PES). The measured photoelectron spectrum features a broad band having an onset at ∼1.1 eV and a maximum at the electron binding energy (EBE) ranging from 1.7 to 1.9 eV. Calculations performed at the M06-2X/6-31++G** level reveal that the observed PES signal is probably due to a dAdT(•-) complex in which the thymine of the dT nucleoside forms hydrogen bonds that engage its O7 and O8 atoms as well as the 3'- and 5'-hydroxyl groups of 2'-deoxyadenosine (dA), while dT's 3'-hydroxyl group interacts with the N1 of dA. In this heterodimer, the excess electron is entirely located on thymine. The biologically relevant Watson-Crick arrangement of the dAdT(•-) dimer was found to be substantially less stable (by ∼19 kcal mol(-1) in Gibbs free energy scale) than the above-mentioned configuration; hence, it is not populated in the gas phase.

In spite of extremely high piezoelectric and pyroelectric coefficients, there are few reports on flexible ferroelectric perovskite film based nanogenerators (NGs). Here, we report the successful growth of a flexible Pb(Zr0.52Ti0.48)O3 (PZT) film and its application to hybrid piezoelectric-pyroelectric NG. A highly flexible Ni-Cr metal foil substrate with a conductive LaNiO3 bottom electrode enables the growth of flexible PZT film having high piezoelectric (140 pC/N) and pyroelectric (50 nC/cm(2)K) coefficients at room temperature. The flexible PZT-based NG effectively scavenges mechanical vibration and thermal fluctuation from sources ranging from the human body to the surroundings such as wind. Furthermore, it stably generates electric current even at elevated temperatures of 100 °C, relative humidity of 70%, and pH of 13 by virtue of its high Curie temperature and strong resistance for water and base. As proof of power generation under harsh environments, we demonstrate the generation of extremely high current at the exhaust pipe of a car, where hot CO and CO2 gases are rapidly expelled to air. This work expands the application of flexible PZT film-based NG for the scavenging mechanical vibration and thermal fluctuation energies even at extreme conditions.

The intact thymidine homodimer anion (dT(2)(-)) was generated in the gas phase using an infrared desorption/photoemission source and recorded by a pulsed photoelectron spectrometer. The photoelectron spectrum (PES) revealed a broad signal with the maximum at electron binding energy ∼2.0 eV and the threshold value at 1.1 eV. The relative energies and vertical detachment energies of the possible anion structures were calculated at the B3LYP/6-31++G(d,p) level. Here we report that the most stable anion radical homodimer geometries observed in the PES are the anionic nucleoside coordinated by the O8 atom of thymine to the deoxyribose of the second neutral nucleoside. Unlike previous experimental-computational studies on anionic complexes involving nucleobases with proton donors, the electron-induced proton-transferred structures are not responsible for the shape of the PES of dT(2)(-).

Understanding and controlling aggregation structures of conjugated polymers (CPs) in aqueous solutions is critical to improving the physical and photophysical properties of CPs for biological applications. Here, we present spectroscopic evidence, including nuclear magnetic resonance (NMR) spectroscopic results, that different organic acid treatment induces different aggregation structures and photophysical properties of CPs in water. Conjugated polymer nanoparticles (CPNs) were fabricated by treating a non-aqueous soluble, primary amine-containing poly(phenylene ethynylene) (PPE-NH(2)) with organic acids followed by dialysis. CPNs formed by acetic acid (AA) treatment (CPN-AAs) exhibit characteristics of loose aggregation with minimal π-π stacking, while CPNs formed by tartaric acid (TA) treatment (CPN-TAs) exhibit a high degree of π-π stacking among PPE-NH(2) chains. The controlled aggregation for a specific application was demonstrated by comparing the fluorescence quenching abilities of the CPN-AAs and the CPN-TAs. A doubled Stern-Volmer constant was obtained from the densely packed CPN-TAs compared to that of the loosely aggregated CPN-AAs.

Anion photoelectron spectra of Ga(x)N(y)(-) cluster anions, in which x = 4-12, y = 1 and x = 7-12, y = 2, were measured. Ab initio studies were conducted on Ga(x)N(y)(-) cluster anions in which x = 4-7, y = 1 and Ga(7)N(2)(-), providing their structures and electronic properties. The photoelectron spectra were interpreted in terms of the computational results. This allowed for identification of the isomers present in the beam experiments for specific Ga(x)N(-) cluster anions (x = 4-7). The unexpected presence of Ga(x)N(2)(-) species is also reported.

The photoelectron spectrum for (1-methylthymine)-(9-methyladenine)...(formic acid) (1MT-9MA...FA) anions with the maximum at ca. 1.87 eV was recorded with 2.54 eV photons and interpreted through the quantum-chemical modeling carried out at the B3LYP/6-31+G(d,p) level. The relative free energies of the anions and their calculated vertical detachment energies suggest that only seven anionic structures contribute to the observed PES signal. We demonstrate that electron binding to the (1MT-9MA...FA) complex can trigger intermolecular proton transfer from formic acid, leading to the strong stabilization of the resulting radical anion. The SOMO distribution indicates that an excess electron may localize not only on the pyrimidine but also on the purine moiety. The biological context of DNA-environment interactions concerning the formation of single-strand breaks induced by excess electrons has been briefly discussed.

Photoelectron spectroscopy was utilized to study a variety of LnSi(n)(-) cluster anions (Ln = Yb, Eu, Sm, Gd, Ho, Pr; 3 or= 10, adopt a nominal +2 oxidation state while Ho, Pr, Gd, and in case of Sm, sizes n

The photoelectron spectrum for the radical anion of 9-methylguanine-1-methylcytosine, MGMC(-), was recorded for the first time. To interpret the experimental results, B3LYP/6-31++G(d,p) level computational studies were carried out for the neutral and anionic complexes of MGMC/MGMC(-) stabilized by three hydrogen bonds and comprising canonical or low-energy tautomeric forms of the methylated nucleobases. The visualization of singly occupied molecular orbitals for the MGMC(-) anions indicates that they are valence-bound species since the excess electron is localized on a pi* orbital of cytosine. All but one of the studied anionic complexes are adiabatically stable at the applied B3LYP level of theory. The intensity maximum of the broad band in the photoelectron spectrum was measured at 2.1 eV. This value is very well reproduced by the calculated vertical detachment energy of the calculated global minimum geometry of the MGMC(-) anion. This structure is the Watson-Crick base pair anion with proton transferred from the N1 atom of guanine to the N3 site of cytosine. The calculated adiabatic electron affinities span a range of 0.39-0.60 eV. The consequences of electron attachment to the AT or GC base pairs incorporated within DNA are briefly discussed in the context of DNA damage by low-energy electrons.

The preparation and utilization of novel iodide glycosyl donors, 2-O-iodoacetyl-glycopyranosyl iodides, is described. The mechanism for the reaction of iodine with carbohydrate cyclic ketene acetal was investigated through low-temperature NMR experiments. 2-O-Iodoacetyl-glycopyranosyl iodides can serve as effective glycosyl donors giving 2-O-iodoacetyl 1,2-trans-glycosides in high yields and excellent stereoselectivities. The 2-O-iodoacetyl group was removed selectively with thiourea to afford 2-hydroxy 1,2-trans-glycosides in high yield without affecting other protecting groups and anomeric configurations.

The intramolecular ionic Diels-Alder reaction of alpha-acetylenic acetals as a precursor of the propargyl cation has been investigated in the presence of Lewis acids and in protic acids. The reaction of diene-tethered alpha-acetylenic acetals (1-2) with formic acid yielded the regioselective intramolecular ionic Diels-Alder reaction products, bicyclodienal (9) and bicyclodienone (11) derivatives, in good yields.

The lifetimes of the excited state of free nucleobases were measured in the gas phase for the first time. They are, respectively, 1.0 and 0.8 ps for the purine bases adenine (shown above) and guanine and 3.2, 2.4, and 6.4 ps for the pyrimidine bases cytosine, uracil, and thymine at 267 nm. The longer lifetimes of the pyrimidine bases may be associated with their higher propensity toward photodegradation, especially in the case of thymine. The ultrashort lifetime of nucleobases conventionally known in solution was found to be an intrinsic molecular property due to extremely facile internal conversion, and therefore the lifetime should be largely independent of the medium at this energy, that is, whether in vacuo, in solution, or in vivo. The evolutionary selection of nucleobases as the durable carriers of genetic information is suggested to be due to their inherent immunity from photochemical reactions.

The effects of fish oil and corn oil diets on diethylnitrosamine initiation/phenobarbital promotion of hepatic enzyme-altered foci in female Sprague-Dawley rats were investigated. Groups of 12 rats were initiated with diethylnitrosamine (15 mg/kg) at 24 h of age. After weaning, they received diets containing either 13.5% fish oil plus 1. 5% corn oil or 15% corn oil for 24 weeks. Rats fed fish oil had significantly greater liver weight, relative liver weight, spleen weight, and relative spleen weight than rats fed corn oil (p < 0.05). Hepatic phospholipid fatty-acid profile was significantly affected by the type of dietary lipid. The rats fed fish oil had significantly greater hepatic phospholipid 20:5 and 22:6 than rats fed corn oil; in contrast, the rats fed corn oil had significantly greater hepatic phospholipid 18:2 and 20:4 than rats fed fish oil (p < 0.05). Rats fed fish oil had significantly lower hepatic vitamin E and PGE(2) content but significantly greater hepatic lipid peroxidation than rats fed corn oil (p < 0.05). The hepatic levels of antioxidant enzymes (GSH reductase and GST) were significantly greater in rats fed fish oil than in rats fed corn oil (p < 0.05). Except for PGST-positive foci (foci area/tissue area), all the other foci parameters (GGT-positive foci area/tissue area, GGT-positive foci no./cm(2), GGT-positive foci no./cm(3), PGST-positive foci no. /cm(2), and PGST-positive foci no./cm(3)) measured in the fish oil group were 10-30% of those in the corn oil group (p < 0.05). Analyses of Pearson correlation coefficient revealed a positive correlation between hepatic GGT- or PGST-positive foci number (no. /cm(2)) and PGE(2) content (r = 0.66, P = 0.01; r = 0.56, P = 0.02, respectively) but a negative correlation between GGT- and PGST-positive foci (no./cm(2)) and lipid peroxidation (r = -0.8, P = 0.0006; r = -0.58, P = 0.01, respectively), GSH/(GSH + GSSG) ratio (r = -0.61, P = 0.05; r = -0.4, P = 0.14, respectively), GSH reductase (r = -0.75, P = 0.002; r = -0.53, P = 0.02, respectively), and GST activities (r = -0.65, P = 0.01; r = -0.44, P = 0.07, respectively). Similar correlation between foci number (no./cm(3)) and PGE(2), lipid peroxidation, GSH/(GSH + GSSG) ratio, GSH reductase, and GST activities were obtained. The results of this study show that dietary fish oil significantly inhibited hepatic enzyme-altered foci formation compared with corn oil in rats. These results suggest that the possible mechanisms involved in this process are the stimulation of hepatic detoxification system, changes in membrane composition, inhibition of PGE(2) synthesis, the enhancement of GSH-related antioxidant capacity, and the enhancement of lipid peroxidation by fish oil.