Facilitating Intracellular Electron Bifurcation by Mediating Flavin-Based Extracellular and Transmembrane Electron Transfer: A Novel Role of Pyrogenic Carbon in Dark Fermentation for Hydrogen Production.

Pyrogenic carbon is considered an enhancer to H2-yielding dark fermentation (DF), but little is known about how it regulates extracellular electron transfer (EET) and influences transmembrane respiratory chains and intracellular metabolisms. This study addressed these knowledge gaps and demonstrated that wood waste pyrogenic carbon (biochar) could significantly improve the DF performance; e.g., addition of pyrogenic carbon produced by pyrolysis at 800 °C (PC800) increased H2 yield by 369.7%. Biochemical quantification, electrochemical analysis, and electron respiratory chain inhibition tests revealed that PC800 promoted the extracellular flavin-based electron transfer process and further activated the acceleration of the transmembrane electron transfer. Comparative metagenome/metatranscriptome analyses indicated that the flavin-containing Rnf complex was the potential transmembrane respiratory enzyme associated with PC800-mediated EET. Based on NADH/NAD+ circulation, the promoted Rnf complex could stimulate the functions of the electron bifurcating Etf/Bcd complex and startup of glycolysis. The promoted Etf/Bcd could further contribute to balance the NADH/NAD+ level for glycolytic reactions and meanwhile provide reduced ferredoxin for group A1 [FeFe]-hydrogenases. This proton-energy-linked mechanism could achieve coupling production of ATP and H2. This study verified the important roles of pyrogenic carbon in mediating EET and transmembrane/intracellular pathways and revealed the crucial roles of electron bifurcation in DF for hydrogen production.

Filicinic acid based meroterpenoids from Hypericum elodeoides and their anti-Alzheimer's disease effects.

(±)-Elodeoidileons A-L (1-12), 12 pairs of previously undescribed filicinic acid based meroterpenoids were isolated from Hypericum elodeoides with unique linear or angular 6/6/6 ring core. Modern spectroscopic techniques, modified Mosher's method and quantum chemical calculations were used to identify the planner structures and configurations of 1-12. Additionally, the potential biosynthetic pathways for 1-12 were anticipated. Moreover, biological activity assessments suggested that 1a, 5a, and 11b could activate Retinoid X receptor-α (RXRα) transcription and enhance the ATP-binding cassette transporter A1 (ABCA1) protein's expression. Fluorescence titration assay suggested that 1a might have a direct interaction with the RXRα-LBD protein, with an estimated Kd value of 5.85 µM. Moreover, molecular docking study confirmed the binding of 1a to RXRα and further validated by cellular thermal shift assay (CETSA). Thus, compound 1a may promote ß-amyloid (Aß) clearance by targeting RXRα and upregulating the expression of the ABCA1 protein, showing promise as anti-Alzheimer's agent.

Four undescribed coumarin derivatives, with ten amides from the roots of Ficus hirta and their cytotoxic activities.

Four undescribed coumarin derivatives, ficusalt A (1) and ficusalt B (2), a pair of racemic coumarins, (±) ficudimer A (3a/3b), along with ten known amides, were isolated from the roots of Ficus hirta. Their structures were elucidated by several spectroscopic data analyses, including HRESIMS, NMR, and X-ray single-crystal diffraction. The cytotoxic activities of all compounds against HeLa, HepG2, MCF-7, and H460 cell lines were detected using the MTT assay. Among these, 5 showed the highest activity against HeLa cells. Subsequently, the apoptotic, anti-invasive, and anti-migration effects of 5 on HeLa cells were determined by flow cytometer, transwell invasion assay, and wound-healing assay, respectively. The result suggested that 5 distinctly induced the apoptosis in HeLa cells and inhibited their invasion and migration. Further studies on anticancer mechanisms were conducted using Western blotting. As a result, 5 increased the cleavage of PARP and the expression of pro-apoptotic protein Bax. Moreover, 5 notably upregulated the phosphorylation of p38 and JNK, whereas inhibited the expression of p-ERK and p-AKT. Our results demonstrated that 5 could be a potential leading compound for further application in the treatment of cervical cancer.

Comprehensive Analysis on Prognostic Signature Based on T Cell-Mediated Tumor Killing Related Genes in Gastric Cancer.

Although immunotherapy is a valuable treatment for gastric cancer (GC), identifying the patients who would benefit most from this approach presents a challenge. In this study, GC patients were divided into two subtypes by consensus clustering according to T cell-mediated tumor killing related genes (TTKRGs), and there were significant differences in tumor-infiltrating immune cells, signaling pathways, and gene expression of immunomodulators and inhibitory immune checkpoints between the two subtypes. Then, we developed an individualized signature based on TTKRGs, and its clinical and predictive value in GC patients for chemotherapeutic and immunotherapeutic responses was assessed. We confirmed the expression levels of signature genes in GC tumor tissue using quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, to improve the accuracy of GC prognosis predictions, we established a nomogram. We further identified some compounds as sensitive drugs targeting GC risk groups. The signature showed significant predictive ability across RNA-seq, microarray, and qRT-PCR cohorts, which could assist in predicting survival, immunotherapeutic and chemotherapeutic outcomes in GC patients.

Sub-high amylose maize starch: an ideal substrate to generate starch with lower digestibility by fermentation of Qu.

BACKGROUND: The fermentation of Qu (FQ) is a novel method to modify the properties of starch to expand its application and especially to increase the resistant starch (RS) content. Using waxy maize starch (WMS) as a fermentation substrate can increase the RS content significantly but it may be time consuming and not cost effective due to the almost negligible RS content of WMS. To solve this problem, we hypothesized that sub-high amylose starch (s-HAMS), with an amylose content close to 50% could be an ideal substrate for FQ. RESULTS: The results showed that FQ did not change the shape and the particle size of starch granules, the gelatinization peak (Tp), or the conclusion temperature (Tc), but the slowly digested starch content declined. Rapidly digested starch content fluctuated during FQ and the amylose content decreased within 36 h and then increased. Within 24h, FQ significanlty increased these values: the RS content, relative crystallinity (RC), the ratio of FTIR absorbances at 1047/1022cm-1, the diffraction peak at 19.8° in X-ray diffraction (XRD), and the gelatinization onset temperature (To) increased significantly, within 24 h of FQ. However, after 24 h of fermentation, the RS content, RC, the ratio of FTIR absorbances at 1047/1022 cm-1, and gelatinization enthalpy (ΔH) decreased significantly. CONCLUSION: Sub-high amylose starch is more suitable for FQ to produce low digestibility starch, and the increase in RS may be due to the formation of 'amylose-lipid' complexes (RS5). © 2024 Society of Chemical Industry.

Boosting Stimulated Emission via a Hydrogen-Bonded Co-Crystallization Approach in Molecular Crystals.

Stimulated emission of organic π-conjugated molecule in solid state remains a significant challenge, mainly involving the mode of molecular stacking that invariably alters the photo-physical processes. Herein, we successfully realized the stimulated emission in molecular crystals using a hydrogen-bonded co-crystallization strategy. Two hydrogen-bonded co-crystals, obtained from 1,4-bis-p-cyanostyrylbenzene (CNDSB) and two types of co-formers, can boost stimulated emission and show decent amplified spontaneous emission (ASE), whereas the parent CNDSB crystal is not SE-active. Crystal structural analysis demonstrated that the co-crystallization eliminated excimer formation. The resulting higher kr and shorter excited-lifetime led to a larger stimulated-emission cross section, which benefited to the occurrence of ASE. Simultaneously, the uniaxial arrangements along long axis of co-crystal together contributed to highly polarized emission. This system presents very rare evidence of boosting stimulated emission by binary co-crystallization, which enriches our insights into organic solid-state lasers.

Conformation-Confined Organic Butterfly-Molecule with High Photoluminescence Efficiency, Deep-Blue Amplified Spontaneous Emission, and Unique Piezochromic Luminescence.

Organic fluorophores with tunable π-conjugated paths have attracted considerable attention owing to their diverse properties and promising applications. Herein, we present a tailored butterfly like molecule, 2,2'-(2,5-bis (2,2-diphenylvinyl)-1,4-phenylene)dinaphtha-lene (BDVPN), which exhibits diverse photophysical features in its two polymorphs. The BP phase crystal, with its "aligned wings" conformation, possesses emissive characteristics that are nearly identical to those in dilute solutions. In contrast, the BN phase crystal, which adopts an "orthogonal wings" conformation, exhibits an unusual hypsochromic-shifted emission compared to its dilute solution counterparts. This intriguing hypsochromic-shifted emission originates from the reduction in the effective conjugated length of the molecular skeleton. Notably, BN phase crystals also exhibit exceptional optical performance, featuring high-efficiency emission (76.6%), low-loss optical waveguides (0.571 dB mm-1), deep-blue amplified spontaneous emission (ASE) with a narrow full width at half maximum (FWHM: 6.4 nm), and a unique 200 nm bathochromic shift of piezochromic luminescence.

Vimentin and tumor-stroma ratio for neoadjuvant chemoradiotherapy response prediction in locally advanced rectal cancer.

Vimentin expression in tumor tissues and the tumor-stroma ratio (TSR) have been demonstrated as strong prognostic factors for cancer patients, but whether they are predictive markers of neoadjuvant chemoradiotherapy (nCRT) outcome in locally advanced rectal cancer (LARC) patients is poorly understood. This study aimed to explore the predictive significance of vimentin and TSR combined for nCRT response in LARC patients. Imaging mass cytometry (IMC) was performed to determine the association of vimentin and TSR with nCRT response in six LARC patients [three achieved pathological complete response (pCR), three did not]. Immunohistochemistry (IHC) for vimentin and TSR on biopsy tissues before nCRT and logistic regression analysis were performed to further evaluate their predictive value for treatment responses in a larger patient cohort. A trend of decreased vimentin expression and increased TSR in the pCR group was revealed by IMC. In the validation group, vimentin [odds ratio (OR) 0.260, 95% confidence interval (CI) 0.102-0.602, p = 0.002] and TSR (OR 4.971, 95% CI 1.933-15.431, p = 0.002) were associated with pCR by univariate analysis. Patients in the vimentin-low/TSR-low or vimentin-high/TSR-high (OR 5.211, 95% CI 1.248-35.582, p = 0.042) and vimentin-low/TSR-high groups (OR 11.846, 95% CI 3.197-77.079, p = 0.001) had significantly higher odds of pCR. By multivariate analysis, only the combination of vimentin and TSR was an independent predictor for nCRT response (OR 9.324, 95% CI 2.290-63.623, p = 0.006). Our study suggested that the combined assessment of vimentin and TSR can provide additive significance and may be a promising indicator of nCRT response in LARC patients.

Controllable Crystallization of Two-Dimensional Bi Nanocrystals with Morphology-Boosted CO2 Electroreduction in Wide pH Environments.

Two-dimensional low-melting-point (LMP) metal nanocrystals are attracting increasing attention with broad and irreplaceable applications due to their unique surface and topological structures. However, the chemical synthesis, especially the fine control over the nucleation (reduction) and growth (crystallization), of such LMP metal nanocrystals remains elusive as limited by the challenges of low standard redox potential, low melting point, poor crystalline symmetry, etc. Here, a controllable reduction-melting-crystallization (RMC) protocol to synthesize free-standing and surfactant-free bismuth nanocrystals with tunable dimensions, morphologies, and surface structures is presented. Especially, ultrathin bismuth nanosheets with flat or jagged surfaces/edges can be prepared with high selectivity. The jagged bismuth nanosheets, with abundant surface steps and defects, exhibit boosted electrocatalytic CO2 reduction performances in acidic, neutral, and alkaline aqueous solutions, achieving the maximum selectivity of near unity at the current density of 210 mA cm-2 for formate evolution under ambient conditions. This work creates the RMC pathway for the synthesis of free-standing two-dimensional LMP metal nanomaterials and may find broader applicability in more interdisciplinary applications.

Low-Pressure Sensitive Piezochromic Fluorescence Switching of Tetraphenylethylene-Anthraquinone.

Invited for the cover of this issue are Prof. Wenjing Tian and co-workers at Jilin University. The image depicts the highly sensitive piezochromic fluorescence switching of tetraphenylethylene-anthraquinone under low-pressure regimes (∼60 kPa). Read the full text of the article at 10.1002/chem.202301070.

Low-Pressure Sensitive Piezochromic Fluorescence Switching of Tetraphenylethylene-Anthraquinone.

Sensing of low-pressure signals is of great importance for cutting-edge technologies. Organic piezochromic molecules offer a promising library of pressure sensitive materials which can be tailor-designed toward specific requirements. However, very few examples of low-pressure sensitive piezochromic fluorescent molecules have been obtained till date, and the underlying mechanisms are still in its infancy. Herein, we report highly sensitive piezochromic fluorescent switching under low-pressure regimes (∼60 kPa) of tetraphenylethylene-anthraquinone (TPE-AQ) based on the controlled molecular design and polymorphic phase strategy. The influence of both intramolecular conformation effect and variations of intermolecular stacking modes on the piezochromic property of TPE-AQ is investigated. The underlying mechanism of the low-pressure sensitive piezochromic fluorescence switching is demonstrated to be closely related to the loosely packed molecular orientation, as confirmed by X-ray diffraction measurements combined with simulations. This work provides a way to design highly efficient pressure sensors based on organic molecular systems.

Enhancement of Circularly Polarized Luminescence from Pulsating Nanotubules.

Enhancing the dissymmetry factor (glum ) is a crucial issue in developing circularly polarized luminescence (CPL) materials. Herein, based on supramolecular self-assembly of diethyl l-glutamate-cyanodiarylethene (L-GC) in mixed solution of EtOH-H2 O with different water fraction, enhanced circularly polarized emission from pulsating nanotubules is realized. In the mixture of ethanol and water (30/70, v/v), L-GC self-assembles into roll-up-type dense nanotubes and shows l-CPL. Remarkably, by increasing the water fraction to 80% and 90%, the diameter of the roll-up nanotubes increases and the dissymmetry factor of the nanotubes is significantly enhanced from 6.9 × 10-3  (dense nanotubes) to 3.7 × 10-2 (loose nanotubes) because of the enhanced intermolecular interactions and more ordered supramolecular stacking when increasing the water fraction. An efficient way is provided here to realize the increase of the dissymmetry factor by only changing the composition of solvents.

Apocarotenoids from Equisetum debile Roxb. ex Vaucher regulate the lipid metabolism via the activation of the AMPK/ACC/SREBP-1c signaling pathway.

Sixteen undescribed apocarotenoids (1-16), along with 22 known analogues, were isolated from the aerial parts of Equisetum debile. Their structures, including absolute configurations, were elucidated by NMR, HRESIMS, X-ray diffraction analysis, the modified Mosher's method and the quantum-chemical calculation of electronic circular dichroism (ECD) spectra. Compounds 1-9, 11-12 are the first example of C16-apocarotenoids appeared in nature. The plausible biosynthetic pathway of 1-16 was proposed. Moreover, the isolates were evaluated for their lipid-lowering activity, and the results showed that 13, 14, 15, 22, 31, 32 and 33 could remarkably decrease the levels of both TC and TG in FFA induced HepG2 cells at 20 µM. The oil red staining assay further demonstrated the lipid-lowering effects of 13, 14 and 15. The western blot results indicated that compounds 13, 14 and 15 could regulate the lipid metabolism via the activation of the AMPK/ACC/SREBP-1c signaling pathway. A preliminary structure-activity relationship (SAR) study of the isolates indicated that the apocarotenoids with 6/5 ring system displayed more potent lipid-lowering effects.

Joint Effects Between CDKN2B/P15 Methylation and Environmental Factors on the Susceptibility to Gastric Cancer.

BACKGROUND: The incidence of gastric cancer has long been at a high level in China, seriously affecting the health of Chinese people. AIMS: This case‒control study was performed to identify gene methylation biomarkers of gastric cancer susceptibility. METHODS: A total of 393 gastric cancer cases and 397 controls were included in this study. Gene methylation in peripheral blood leukocytes was detected by a methylation-sensitive high-resolution melting method, and the Helicobacter pylori antibody presence was semi-quantified in serum by ELISA. RESULTS: Individuals with total methylation of CDKN2B/P15 had a 1.883-fold (95%CI: 1.166-3.040, P = 0.010) risk of gastric cancer compared with unmethylated individuals. Individuals with both CDKN2B/P15 and NEUROG1 methylation had a higher risk of gastric cancer (OR = 2.147, 95% CI: 1.137-4.073, P = 0.019). The interaction between CDKN2B/P15 and NEUROG1 total methylation on gastric cancer risk was affected by the pattern of adjustment. In addition, the joint effects between CDKN2B/P15 total methylation and environmental factors, such as freshwater fish intake (OR = 6.403, 95% CI = 2.970-13.802, P < 0.001), irregular diet (OR = 5.186, 95% CI = 2.559-10.510, P < 0.001), unsanitary water intake (OR = 2.238, 95% CI = 1.144-4.378, P = 0.019), smoking (OR = 2.421, 95% CI = 1.456-4.026, P = 0.001), alcohol consumption(OR = 2.163, 95% CI = 1.309-3.576, P = 0.003), and garlic intake(OR = 0.373, 95% CI = 0.196-0.709, P = 0.003) on GC risk were observed, respectively. However, CDKN2B/P15 and NEUROG1 total methylation were not associated with gastric cancer prognosis. CONCLUSION: CDKN2B/P15 methylation in peripheral blood may be a potential biomarker for evaluating susceptibility to gastric cancer. The joint effects between CDKN2B/P15 methylation and environmental factors may also contribute to gastric cancer susceptibility.

Polymorphic Covalent Organic Frameworks: Molecularly Defined Pore Structures and Iodine Adsorption Property.

Radioactive iodine-capturing materials are urgently needed for the emerging challenges in nuclear waste disposal. The various pore structures of covalent organic frameworks (COFs) render them promising candidates for efficient iodine adsorption. However, the detailed structure-property relationship of COFs in iodine adsorption remains elusive. Herein, two polymorphic COFs with significantly different crystalline structures are obtained based on the same building blocks with varied molecular ratios. The two COFs both have high crystallinity, high specific surface area, and excellent chemical and thermal stability. Compared with the [C4+C4] topology (PyT-2) with an AA stacking form, the [C4+C2] topology (PyT-1) with an AB stacking form has more twisted pore channels and complex ink-bottle pores. At ambient conditions, PyT-1 and PyT-2 both exhibit good adsorption properties for iodine capture either in a gaseous or liquid medium. Remarkably, PyT-1 presents an excellent maximum adsorption capacity (0.635 g g-1), and the adsorption limit of PyT-2 is 0.445 g g-1 in an n-hexane solution with an iodine concentration of 400 mg L-1, which is highly comparable to the state-of-the-art iodine absorption performance. This study provides a guide for the future molecular design strategy toward novel iodine adsorbents.

Photoinduced Fluorescence Switching in Molecular Aggregates by Topological [2+2] Cycloaddition.

The optical modulation of fluorescence characteristics in molecular aggregates, which mainly involves diverse molecular stacking and the consequent intermolecular interactions, remains a significant challenge for potential applications in optical anticounterfeiting, data storage, and imaging. Here we successfully realize in situ fluorescence switching in molecular aggregates of thianaphthene-dioxide derivatives by topological [2+2] photocycloaddition, which represents a promising way to regulate the molecular stacking and alter photophysical processes. Notably, 2-(3,5-bis-trifluoromethylphenyl)benzo[b]thiophene-dioxide (BTO-TF) in both crystal and powder forms exhibits a unique switching from an initial nonfluorescent state to a highly fluorescent state (ΦPL =0.46) upon UV irradiation, because of the destruction of the [2+2] cycloaddition process by volume expansion of the photodimer. Furthermore, we demonstrate such a [2+2] photocycloaddition can occur when 2-(4-carboxypheny)benzo[b]thiophene-dioxide (BTO-OH) is doped within selective polymer matrixes, and can be utilized for the visualization of macrophase separation in polymer blends.

Risk and Prognosis of Second Primary Cancers among Ovarian Cancer Patients, Based on SEER Database.

The purposes of the present study were to elucidate the risk and prognostic effect of second primary cancers (SPCs) development, as well as the factors influencing the prognosis of OC patients with SPCs. A statistically significant increase in SPCs risk was observed among OC patients during 2004-2015. The independent factors were used to construct the SPCs-prediction nomogram and the OS-prediction nomogram. Both nomogram were subjected to internal validation and performed well. OC patients with SPCs have a better prognosis than patients without SPCs. Propensity score matching (PSM) was applied to reduce confounding.

An Oxidant- and Catalyst-Free Electrooxidative Cross-Coupling Approach to Synthesize meso-Substituted Porphyrin Derivatives.

The synthesis of porphyrin and chlorin derivatives has attracted significant attention due to their numerous applications. Herein, we report an environment friendly oxidant- and catalyst-free electrooxidative cross-coupling approach for multiple coupling reactions to synthesize meso C-N, C-O, and C-S substituted porphyrin and chlorin derivatives. For C-N cross-coupling reactions, diaminated porphyrins were obtained as the main products, while using 4-bromo-2,6-dimethyl aniline resulted in monoaminated product. Similarly, electrochemical catalysis of porphyrins with phenol and thiophene produced meso-disubstituted porphyrins in moderate yields under a smaller current. Chlorins were also applicable, and 20-substituted products were efficiently produced regioselectively. To the best of our knowledge, this work represents the first example of electrooxidative C-X cross-coupling of porphyrins and chlorins.

Discrete Platinum(II) Metallacycles with Inner- and Outer-Modified 9,10-Distyrylanthracene: Design, Self-Assembly, and Luminescence Properties.

To completely unravel the relationship between structures and luminescence properties of inner- and outer-modified metallacycles, two rhombic metallacycles S1 and S2 with 9,10-distyrylanthracene (DSA) were constructed herein via the design of DSA moieties on the inside or outside of metallacycles. Similar building blocks of the two metallacycles led to the same emission wavelengths in a dilute solution. In contrast, their fluorescence emissions in the aggregation and solid states were significantly different and revealed interesting emission behaviors from structures with inner- and outer-modified design. Finally, based on their luminescence properties, a tunable solid-state fluorescence emissive material was easily obtained by the mixing of two supramolecules in different ratios. This unique design suggested that the modified position of fluorophores exerts a key impact on the adjustment of luminescence from a dilute solution to the aggregated state and will be of great significance for the development of luminescent materials based on supramolecules.

Urchin-like PdOs nanostructure for hydrogen evolution electrocatalysis.

The compositional and structural engineering of advanced nanomaterials for hydrogen evolution reaction (HER) is highly necessary for efficient hydrogen production. Herein, PdOs nanospine assemblies (PdOs NAs) with urchin-like structures are fabricated via one-step route using DM-970 and KBr as surfactant agent and capping agent, respectively. Benefiting from electronic effect and multi-branched structure, the PdOs NAs exhibit superior performance for HER in alkaline and neutral solutions, requiring overpotentials of 28 and 35 mV at -10 mA cm-2, respectively, as well as superior long-term stability. This study offers a universal approach for the fabrication of active Pd-based catalysts with multi-branched morphology for efficient water electrolysis and beyond.