High-Entropy Alloy Electrocatalysts Bidirectionally Promote Lithium Polysulfide Conversions for Long-Cycle-Life Lithium-Sulfur Batteries.

High-entropy alloys (HEAs) have attracted considerable attention, owing to their exceptional characteristics and high configurational entropy. Recent findings demonstrated that incorporating HEAs into sulfur cathodes can alleviate the shuttling effect of lithium polysulfides (LiPSs) and accelerate their redox reactions. Herein, we synthesized nano Pt0.25Cu0.25Fe0.15Co0.15Ni0.2 HEAs on hollow carbons (HCs; denoted as HEA/HC) by a facile pyrolysis strategy. The HEA/HC nanostructures were further integrated into hypha carbon nanobelts (HCNBs). The solid-solution phase formed by the uniform mixture of the five metal elements, i.e., Pt0.25Cu0.25Fe0.15Co0.15Ni0.2 HEAs, gave rise to a strong interaction between neighboring atoms in different metals, resulting in their adsorption energy transformation across a wide, multipeak, and nearly continuous spectrum. Meanwhile, the HEAs exhibited numerous active sites on their surface, which is beneficial to catalyzing the cascade conversion of LiPSs. Combining density functional theory (DFT) calculations with detailed experimental investigations, the prepared HEAs bidirectionally catalyze the cascade reactions of LiPSs and boost their conversion reaction rates. S/HEA@HC/HCNB cathodes achieved a low 0.034% decay rate for 2000 cycles at 1.0 C. Notably, the S/HEA@HC/HCNB cathode delivered a high initial areal capacity of 10.2 mAh cm-2 with a sulfur loading of 9 mg cm-2 at 0.1 C. The assembled pouch cell exhibited a capacity of 1077.9 mAh g-1 at the first discharge at 0.1 C. The capacity declined to 71.3% after 43 cycles at 0.1 C. In this work, we propose to utilize HEAs as catalysts not only to improve the cycling stability of lithium-sulfur batteries, but also to promote HEAs in energy storage applications.

Exquisitely constructing hierarchical carbon nanoarchitectures decorated with sulfides for high-performance Li-S batteries.

The sluggish reaction kinetics and notorious shuttle effect of polysulfides significantly hinder the practical application of lithium-sulfur batteries (LSBs). Therefore, polysulfides are anchored and their conversion reactions are catalyzed to enhance the performance of LSBs. Herein, an exquisite hierarchical carbon nanoarchitecture decorated with sulfides is designed and introduced into LSBs. Systematic experiments show that the nanoarchitecture not only enables rapid electron/ion migration but also functions as an active catalyst to increase polysulfide conversion, thus effectively reducing the shuttle effect. As a result, LSBs with the nanoarchitecture modified separator exhibited outstanding rate capacity (724.9 mA h g-1 at 5C), low self-discharge capacity loss (4.1% capacity loss after 72 h), and exceptional reversible capacity (1518.3 mA h g-1 at 0.1C and 25.6% capacity loss after 100 cycles). Through the design of a multifunctional separator, this study offers an effective way to minimize the shuttle effect and speed up redox conversion. The strategy of constructing nanoarchitectures provides an innovative route for hierarchical heterocatalyst design for LSBs.

Achieving High-Performance Self-Powered Visible-Blind Ultraviolet Photodetection Using Alloy Engineering.

The exploration and development of self-powered visible-blind ultraviolet photodetectors (VBUV PDs) with high responsivity and wavelength selectivity have far-reaching significance for versatile applications. Although In2O3 shows potential for UV detection due to good UV absorption and electrical transport properties, the poor wavelength selectivity impedes further application in VBUV PDs. Here, a self-powered photoelectrochemical-type (PEC) VBUV PD is demonstrated by using gallium-indium oxide alloys (Ga-In OAs). The self-powered Ga-In OAs-based PEC VBUV PDs exhibit good VBUV photodetection performance, including a high responsivity of 50.04 mA/W and a high detectivity of 6.03 × 1010 Jones under 254 nm light irradiation, a good wavelength selectivity (UV/visible light rejection ratio of 262.45), and a fast response time (0.45/0.38 s). The good self-powered VBUV detection performance of Ga-In OAs is attributed to the larger band gap and smaller charge-transfer resistance induced by alloy engineering, which not only suppresses the absorption of visible light but also accelerates interfacial charge transfer. Moreover, an underwater optical communication system is demonstrated by using the self-powered Ga-In OAs PEC VBUV PDs. This study demonstrates that alloy engineering is a powerful tool to improve the performance of In2O3-based PEC PDs, and Ga-In OAs have great application potential for underwater optoelectronic devices.

Application of preoperative 3D printing in the internal fixation of posterior rib fractures with embracing device: a cohort study.

BACKGROUND: To explore the impact of preoperative 3D printing on the fixation of posterior rib fractures utilizing a memory alloy embracing device of rib under thoracoscopy. METHODS: The enrolled patients were divided into the 3D printing (11 patients) and the non-3D printing (18 patients) groups, based on whether a 3D model of ribs was prepared prior to surgery. Analysis was conducted comparing the average fixation time per fracture, postoperative fixation loss, and poor reduction of fractured end between the two groups. RESULTS: The average fixation time of each fracture was 27.2 ± 7.7 min in the 3D printing group and 29.3 ± 8.2 min in the non-3D printing group, with no statistically significant difference observed between the two groups (P > 0.05). The incidence of poor fracture fixation in the 3D printing group was statistically lower than that in the non-3D printing group (12.9% vs. 44.7%, P < 0.05). Further stratified analysis revealed that the off-plate rate in the 3D printing group and the non-3D group was (3.2% vs. 12.8%, P > 0.05), and the dislocation rate of the fractured end was (9.7% vs. 31.9%, P < 0.05). CONCLUSIONS: The application of 3D printing technology to prepare the rib model before surgery is proves beneficial in reducing the occurrence of poor fixation of fractures and achieving precise and individualized treatment.

Diagnostic value of D-dimer for lower extremity deep venous thrombosis caused by rib fracture: a retrospective study.

OBJECTIVE: This study aimed to investigate the role of D-dimer in the diagnosis of lower extremity deep venous thrombosis (DVT) in patients with rib fractures. METHOD: Retrospective analysis was conducted on the clinical data of 499 patients with rib fractures who were admitted to the Third Hospital of Shijiazhuang between October 2020 and September 2021. These patients were divided into the DVT and the non-DVT groups. D-dimer levels were compared between the two groups at 24, 48, and 72 h after the injury. Receiver operating characteristic curves were utilized to evaluate the diagnostic efficacy of dynamically monitoring changes in D-dimer for DVT. RESULTS: The D-dimer levels in the DVT group were significantly higher than those in the non-DVT group at 24, 48, and 72 h after the injury. The area under the curve values for predicting DVT based on D-dimer level at 24, 48, and 72 h after injury in patients with rib fractures were 0.788, 0.605, and 0.568, respectively. CONCLUSION: Detecting D-dimer levels 24 h after the injury can enhance diagnostic efficacy and sensitivity for DVT, thereby reducing the rate of missed diagnoses, which is of great clinical value.

Environmental Enrichment Protects Offspring of a Rat Model of Preeclampsia from Cognitive Decline.

Preeclampsia affects 5-7% of all pregnancies and contributes to adverse pregnancy and birth outcomes. In addition to the short-term effects of preeclampsia, preeclampsia can exert long-term adverse effects on offspring. Numerous studies have demonstrated that offspring of preeclamptic women exhibit cognitive deficits from childhood to old age. However, effective ways to improve the cognitive abilities of these offspring remain to be investigated. The aim of this study was to explore whether environmental enrichment in early life could restore the cognitive ability of the offspring of a rat model of preeclampsia and to investigate the cellular and molecular mechanisms by which EE improves cognitive ability. L-NAME was used to establish a rat model of preeclampsia. The spatial learning and memory abilities and recognition memory of 56-day-old offspring were evaluated by the Morris water maze and Novel object recognition (NOR) task. Immunofluorescence was performed to evaluate cell proliferation and apoptosis in the DG region of the hippocampus. qRT-PCR was performed to examine the expression levels of neurogenesis-associated genes, pre- and postsynaptic proteins and inflammatory cytokines. An enzyme-linked immune absorbent assay was performed to evaluate the concentration of vascular endothelial growth factor (VEGF) and inflammatory cytokines in the hippocampus. The administration of L-NAME led to increased systolic blood pressure and urine protein levels in pregnant rats. Offspring in the L-NAME group exhibited impaired spatial learning ability and memory as well as NOR memory. Hippocampal neurogenesis and synaptic plasticity were impaired in offspring from the L-NAME group. Furthermore, cell apoptosis in the hippocampus was increased in the L-NAME group. The hippocampus was skewed to a proinflammatory profile, as shown by increased inflammatory cytokine levels. EE improved the cognitive ability of offspring in the L-NAME group and resulted in increased hippocampal neurogenesis and synaptic protein expression levels and decreased apoptosis and inflammatory cytokine levels. Environmental enrichment resolves cognitive impairment in the offspring of a rat model of preeclampsia by improving hippocampal neurogenesis and synaptic plasticity and normalizing the apoptosis level and the inflammatory balance.

Modulating Electron Conducting Properties at Lithium Anode Interfaces for Durable Lithium-Sulfur Batteries.

The lithium (Li) ion and electron diffusion behaviors across the actual solid electrolyte interphase (SEI) play a critical role in regulating the Li nucleation and growth and improving the performance of lithium-sulfur (Li-S) batteries. To date, a number of researchers have pursued an SEI with high Li-ion conductivity while ignoring the Li dendrite growth caused by electron tunneling in the SEI. Herein, an artificial anti-electron tunneling layer with enriched lithium fluoride (LiF) and sodium fluoride (NaF) nanocrystals is constructed using a facile solution-soaking method. As evidenced theoretically and experimentally, the LiF/NaF artificial SEI exhibits an outstanding electron-blocking capability that can reduce electron tunneling, resulting in dendrite-free and dense Li deposition beneath the SEI, even with an ultrahigh areal capacity. In addition, the artificial anti-electron tunneling layer exhibits improved ionic conductivity and mechanical strength, compared to those of routine SEI. The symmetric cells with protected Li electrodes achieve a stable cycling of 1500 h. The LiF/NaF artificial SEI endows the Li-S full cells with long-term cyclability under conditions of high sulfur loading, lean electrolyte, and limited Li excess. This study provides a perspective on the design of the SEI for highly safe and practical Li-S batteries.

Perfluorooctane sulfonate exposure induces preeclampsia-like syndromes by damaging trophoblast mitochondria in pregnant mice.

Preeclampsia, defined as a hypertensive disorder during pregnancy, is a major cause of maternal and fetal mortality. Observational studies have shown that the exposure of per- and polyfluoroalkyl substances, such as perfluorooctane sulfonate (PFOS), is emerging as a significant environmental factor associated with preeclampsia risk. However, epidemiologic evidence is of correlative in nature, and unable to establish a causal relationship. Here, we established an animal model of PFOS-induced preeclampsia to explore the molecular mechanism of PFOS in placental trophoblast. In the mouse model, PFOS exposure by gavage at a dose of 10 mg/kg/d from embryonic day 7.5-16.5 was sufficient to induce preeclampsia-like symptoms such as hypertension, proteinuria, and renal glomerular endotheliosis, accompanied with placental abnormal stromal collagen deposition. In-vitro experiments of JEG-3 cells, PFOS exposure impaired trophoblast motility including the compromised abilities of migration, invasion and vascularization. Mechanistically, these pathological effects on cells resulted from SLC25A5-mediated mitochondrial damages, characterized by excessive ROS generation, decreased ATP production and mitochondrial membrane potential loss, and accompanied by the activation of p38 MAPK and JNK signaling pathways. This pioneering study provided biological plausibility to the causality verified by the animal model and the in vitro experiments, which indicates that PFOS exposure may cause preeclampsia during pregnancy via impairing trophoblast mitochondria.

Mixed-dimensional V2CTx/Ti3C2Tx composite interlayer to boost electrochemical performance of Li-S batteries.

A mixed-dimensional V2CTx/Ti3C2Tx composite interlayer was successfully prepared to tackle severe polysulfide (LiPS) shuttling and sluggish sulfur redox kinetics for high-performance lithium-sulfur batteries. In the unique nanoarchitecture, two-dimensional Ti3C2Tx nanosheets served as a stable skeleton with superb electronic conductivity, good mechanical strength, and high polysulfide adsorption, whereas one-dimensional V2CTx nanorods played a crucial role in chemisorbing LiPSs and catalyzing the conversion of LiPSs due to their high polarity and electrocatalysis. With the synergistic effect of V2CTx and Ti3C2Tx composite nanostructures, the cells with the mixed-dimensional V2CTx/Ti3C2Tx composite interlayer showed an impressive long-term cycling stability and small capacity decay rate of 0.062% per cycle over 600 cycles at 1 C and exhibited an outstanding rate capability of 935.3 mAh·g-1 at 2 C.

Plasmonic Bi nanoparticles encapsulated by N-Carbon for dual-imaging and photothermal/photodynamic/chemo-therapy.

In this work, the plasmonic Bi@N-Carbon@PEG-DOX nanocomposites were constructed to integrate the imaging and synergistic therapy in one nanoplatform. Here, Bi nanoparticles were encapsulated into the N-doped carbon nanomaterials via a simple solvothermal method. The accumulated adjacent semimetal Bi nanoparticles in Bi@N­carbon enhanced the local surface plasmon resonance (LSPR) to make the great NIR harvest and high photothermal converting efficiency (52.3%, Bi@C-2). And that also was confirmed by the Finite Difference Time Domain (FDTD) calculation. Moreover, the LSPR would induce the hot charges (polarization charges), which were captured by O2 and H2O molecules to form ROS for photodynamic therapy (PDT). And the heterostructure of Bi and N­carbon further improved the effective segregation of the hot charges, making the 6.9 times ROS production (Bi@C-2) in comparing with pure Bi sample. In view of the ultrahigh X-ray attenuation coefficient of Bi and great photothermal effect, Bi@N-Carbon@PEG possessed the outstanding computerized tomography (CT) and photothermal imaging capacity. Meanwhile, they also exhibited the favourable biodegradation ability, inducing the elimination via urine and feces within 14 day. The integration of the multi-model (CT and Thermal) imaging and the PTT/PDT/chemotherapy makes Bi@N­carbon@PEG-DOX to be a potential candidate for cancer treatment.

A solution-processed octahedral nano-blocks structure CaIn2S4film for UV/vis photodetection.

A novel CaIn2S4with three-dimensional octahedral nano-blocks (ONBs) are successfully synthesized on fluorine-doped tin oxide (FTO) substrate by a simple hydrothermal method. The CaIn2S4ONBs are uniform grown and scattered on the whole FTO substrate with high regular and symmetric morphology as well as average diagonal length of about 600 nm. Based on the as-synthesized CaIn2S4ONBs, a photodetector (PD) is fabricated. Satisfyingly, it is found that the CaIn2S4ONBs PD achieves a broad-band response ranging from ultraviolet (UV) to visible ( vis) light at zero bias voltage. It is also significant that the CaIn2S4ONBs PD enables a fast response, in which the rise time and decay time are less than 0.15 and 0.2 s, respectively. Furthermore, the morphological evolution of the CaIn2S4ONBs and plausible UV/vis detection mechanism of the CaIn2S4ONBs PD are discussed.

Differentially expressed circular RNAs and the competing endogenous RNA network associated with preeclampsia.

INTRODUCTION: Circular RNAs (circRNAs) are non-coding RNAs that are implicated in preeclampsia (PE) pathogenesis; however, their expression and functions in PE remain unclear. In this study, we aimed to investigate the expression of circRNAs in PE and construct a competing endogenous RNA (ceRNA) network, and analyze the associated pathways in PE pathogenesis. METHODS: We performed circRNA sequencing to identify the differential expression profile of circRNAs in PE as compared to normal pregnancy. The circRNA candidates were validated using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Subsequently, we used datasets from the GEO database to generate the interaction network between circRNAs, microRNAs (miRNAs), and mRNAs. GO and KEGG enrichment analyses were performed to understand the functional significance of the differentially expressed circRNAs in PE. RESULTS: We identified 361 differentially expressed circRNAs (252 upregulated and 109 downregulated) in preeclamptic placentas. Within the selected 31 circRNAs, 6 of them were verified by qRT-PCR. GO and KEGG analyses revealed the potential pathways affected by these circRNAs, e.g., T cell receptor signaling and MAP kinase pathways. A total of 134 miRNAs and 199 mRNAs were revealed to be differentially expressed in PE by analyzing datasets from the GEO database. The circRNA-miRNA-mRNA network comprised 206 circRNAs, 50 miRNAs, and 38 mRNAs. KEGG analysis of the 38 mRNAs included pathways involved in AMPK and PI3K-Akt signaling. DISCUSSION: Our results reported the differential expression profile of circRNAs and the circRNA-miRNA-mRNA network in PE, which provides potential therapeutic targets for this disease.

Exposure to elevated per- and polyfluoroalkyl substances in early pregnancy is related to increased risk of gestational diabetes mellitus: A nested case-control study in Shanghai, China.

BACKGROUND: Long-chain per- and polyfluoroalkyl substances (PFASs) and their short-chain alternatives have been produced and used extensively in China. However, it is unclear whether these compounds contribute to the risk of gestational diabetes mellitus (GDM) in women residing in contaminated areas. OBJECTIVE: The study was performed to explore the association between PFASs varying in chain length and the risk of developing GDM. METHOD: A nested case-control study was conducted in a prospective cohort of 2,460 pregnant women between July 1, 2017, and January 31, 2019 in Shanghai, China. Twelve PFASs of interest were measured using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS) in the sera of pregnant women at 16-20 weeks. GDM was diagnosed by an oral glucose tolerance test administered over 24-28 gestational weeks. The cases and controls were matched by maternal age. The relationship between maternal serum PFAS level and GDM risk was determined by conditional logistic and linear regression analyses. RESULTS: A total of 165 GDM cases and 330 controls were enrolled in the study cohort. The frequencies of detection of PFHpA, PFDS, and PFOSA were all ≤80%. Hence, they were excluded from any further risk analysis. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were detected at relatively high serum levels (medians 6.57 ng/mL and 8.07 ng/mL, respectively). The serum levels of perfluorobutanesulfonic acid (PFBS) and perfluorododecanoic acid (PFDoA) were significantly higher in the GDM group than they were in the control group (P = 0.02 and P < 0.01, respectively) according to a nonparametric Wilcoxon rank sum test. A quartile analysis showed that the odds ratio of GDM would significantly increase at the highest PFBS and PFDoA levels. In the core model, the adjusted ORs were 2.02 (95% CI = 1.04-3.79) and 13.00 (95% CI = 4.74-24.59), respectively, after adjusting for maternal age, sampling time, parity and body mass index [BMI]). CONCLUSION: Elevated maternal serum PFBS and PFDoA levels in early pregnancy may be associated with a substantially higher GDM risk.

The Inhibition of Protein Kinase C ß Contributes to the Pathogenesis of Preeclampsia by Activating Autophagy.

BACKGROUND: Preeclampsia is a devastating hypertensive disorder of pregnancy with unknown mechanism. Recent studies have considered abnormal autophagy as a new cellular mechanism for this disorder, while little is known about how autophagy is specifically involved and what factors are implicated. Here, we report a previously unrecognized preeclampsia-associated autophagic regulator, PKCß, that is involved in placental angiogenesis. METHODS: PKCß levels were evaluated by quantitative real-time PCR, western blotting, immunofluorescence and by the analysis of public data. The autophagy-regulating role of PKCß inhibition in preeclampsia pathogenesis was studied in a mouse model, and in human umbilical vein endothelial cells (HUVECs) and human choriocarcinoma cells (JEG-3). FINDINGS: PKCß was significantly downregulated in human preeclamptic placentas. In a mouse model, the selective inhibition of PKCß by Ruboxistaurin was sufficient to induce preeclampsia-like symptoms, accompanied by excessive autophagic flux and a disruption in the balance of pro- and anti-angiogenic factors in mouse placentas. In contrast, autophagic inhibition by 3-methyladenine partially normalized hypertension, proteinuria and placental angiogenic imbalance in PKCß-inhibited mice. Our in vitro experiments demonstrated that PKCß inhibition activated autophagy, thus blocking VEGFA-induced HUVEC tube formation and resulting in the significant upregulation of sFLT1 and downregulation of VEGFA in JEG-3 cells. INTERPRETATION: These data support a novel model in which autophagic activation due to PKCß inhibition leads to the impairment of angiogenesis and eventually results in preeclampsia. FUNDING: Shanghai Key Program of Clinical Science and Technology Innovation, National Natural Science Foundation of China and Shanghai Medical Center of Key Programs for Female Reproductive Diseases.

The role of immunity in the pathogenesis and development of pre-eclampsia.

Pre-eclampsia (PE) is a leading cause of maternal and perinatal morbidity and mortality; however, the aetiology of PE still remains unclear. It has been widely accepted that the disease results from insufficient spiral artery remodelling, leading to placental ischaemia and the release of a variety of factors. In recent decades, a large number of studies have observed an abnormal immune response in preeclamptic women and studies of both patients and animal models have shown alterations in the function or the number of immune agents. Thus, researchers believe that alterations in the immune system may contribute to the genesis and pathophysiology of PE. Therefore, identifying the role of the immune system can not only shed light on the nature of PE but also contribute to the development of diagnostic and therapeutic methods for PE. This review focuses on the current knowledge of the immune system including both innate and adaptive immunity and sheds light on their role in PE. Additionally, advances in potential therapeutic measures are discussed.

Negative Thermal Expansion over a Wide Temperature Range in Fe-Doped MnNiGe Composites.

Fe-doped MnNiGe alloys were successfully synthesized by solid-state reaction. Giant negative thermal expansion (NTE) behaviors with the coefficients of thermal expansion (CTE) of -285.23 × 10-6 K-1 (192-305 K) and -1167.09 × 10-6 K-1 (246-305 K) have been obtained in Mn0.90Fe0.10NiGe and MnNi0.90Fe0.10Ge, respectively. Furthermore, these materials were combined with Cu in order to control the NTE properties. The results indicate that the absolute value of CTE gradually decreases with increasing Cu contents. In Mn0.92Fe0.08NiGe/x%Cu, the CTE gradually changes from -64.92 × 10-6 K-1 (125-274 K) to -4.73 × 10-6 K-1 (173-229 K) with increasing value of x from 15 to 70. The magnetic measurements reveal that the NTE behaviors in this work are strongly correlated with the process of the magnetic phase transition and the introduction of Fe atoms could also change the spiral anti-ferromagnetic (s-AFM) state into ferromagnetic (FM) state at low temperature. Our study launches a new candidate for controlling thermal expansion properties of metal matrix materials which could have potential application in variable temperature environment.

Rectifying Characteristics and Semiconductor-Metal Transition Induced by Interfacial Potential in the Mn3CuN/n-Si Intermetallic Heterojunction.

The Mn3CuN/n-Si heterojunction device is first designed in the antiperovskite compound, and excellent rectifying characteristics are obtained. The rectification ratio (RR) reaches as large as 38.9 at 10 V, and the open-circuit voltage Voc of 1.13 V is observed under temperature of 410 K. The rectifying behaviors can be well described by the Shockley equation, indicating the existence of a Schottky diode. Simultaneously, a particular semiconductor-metal transition (SMT) behavior at 250 K is also observed in the Mn3CuN/n-Si heterojunction. The interfacial band bending induced inversion layer, which is clarified by the interfacial schematic band diagrams, is believed to be responsible for the SMT and rectifying effects. This study can develop a new class of materials for heterojunction, rectifying devices, and SMT behaviors.

Baromagnetic Effect in Antiperovskite Mn3 Ga0.95 N0.94 by Neutron Powder Diffraction Analysis.

A baromagnetic effect in a novel tetragonal magnetic structure is introduced by vacancies in Mn3 Ga0.95 N0.94 , due to the change of the Mn-Mn distance and their spin re-orientation induced by a pressure field. This effect is proven for the first time in antiperovskite compounds by neutron powder diffraction analysis. This feature will enable wide applications in magnetoelectric devices and intelligent instruments.

[Exploration of Ophiopogon japonicus new parts for medicine material].

OBJECTIVE: To explore the contents of polysaccharides and flavones in different parts of Ophiopogon japonicus for instead of Radix Ophiopgonis as medisine materials. METHODS: The content of polysaccharides was quantified by colorimetry, content of total flavones was determined by spectrophotometry. RESULTS: The content of total flavones in the leaf was distinctly higher than that in the root tuber. CONCLUSIONS: The leaf of Ophiopogon japonicus can be used as medicinal materials to extract the flavones.