Superconductivity and Charge-Density-Wave-Like Transition in Th2Cu4As5.

We report the synthesis, crystal structure, and physical properties of a novel ternary compound, Th2Cu4As5. The material crystallizes in a tetragonal structure with lattice parameters a = 4.0639(3) Å and c = 24.8221(17) Å. Its structure can be described as an alternating stacking of fluorite-type Th2As2 layers with antifluorite-type double-layered Cu4As3 slabs. The measurement of electrical resistivity, magnetic susceptibility, and specific heat reveals that Th2Cu4As5 undergoes bulk superconducting transition at 4.2 K. Additionally, all these physical quantities exhibit anomalies at 48 K, accompanied by a sign change in the Hall coefficient, suggesting a charge-density-wave-like (CDW) phase transition. Drawing from both experimental data and band calculations, we propose that the superconducting and CDW-like phase transitions are, respectively, associated with the Cu4As3 slabs and the As plane in the Th2As2 layers.

G-site residue S67 is involved in the fungicide-degrading activity of a tau class glutathione S-transferase from Carica papaya.

Thiram is a toxic fungicide extensively used for the management of pathogens in fruits. Although it is known that thiram degrades in plant tissues, the key enzymes involved in this process remain unexplored. In this study, we report that a tau class glutathione S-transferase (GST) from Carica papaya can degrade thiram. This enzyme was easily obtained by heterologous expression in Escherichia coli, showed low promiscuity toward other thiuram disulfides, and catalyzed thiram degradation under physiological reaction conditions. Site-directed mutagenesis indicated that G-site residue S67 shows a key influence for the enzymatic activity toward thiram, while mutation of residue S13, which reduced the GSH oxidase activity, did not significantly affect the thiram-degrading activity. The formation of dimethyl dithiocarbamate, which was subsequently converted into carbon disulfide, and dimethyl dithiocarbamoylsulfenic acid as the thiram degradation products suggested that thiram undergoes an alkaline hydrolysis that involves the rupture of the disulfide bond. Application of the GST selective inhibitor 4-chloro-7-nitro-2,1,3-benzoxadiazole reduced papaya peel thiram-degrading activity by 95%, indicating that this is the main degradation route of thiram in papaya. GST from Carica papaya also catalyzed the degradation of the fungicides chlorothalonil and thiabendazole, with residue S67 showing again a key influence for the enzymatic activity. These results fill an important knowledge gap in understanding the catalytic promiscuity of plant GSTs and reveal new insights into the fate and degradation products of thiram in fruits.

Dendrobium huoshanense Polysaccharide Improves High-Fat Diet Induced Liver Injury by Regulating the Gut-Liver Axis.

Dendrobium huoshanense is an important Traditional Chinese medicine that thickens the stomach and intestines. Its active ingredient Dendrobium huoshanense polysaccharide (DHP), was revealed to relieve the symptoms of liver injury. However, its mechanism of action remains poorly understood. This study aimed to investigate the mechanism of DHP in protecting the liver. The effects of DHP on lipid levels, liver function, and intestinal barrier function were investigated in mice with high-fat diet-induced liver damage. Changes in the gut flora and their metabolites were analyzed using 16S rRNA sequencing and metabolomics. The results showed that DHP reduced lipid levels, liver injury, and intestinal permeability. DHP altered the intestinal flora structure and increased the relative abundance of Bifidobacterium animalis and Clostridium disporicum. Furthermore, fecal metabolomics revealed that DHP altered fecal metabolites and significantly increased levels of gut-derived metabolites, spermidine, and indole, which have been reported to inhibit liver injury and improve lipid metabolism and the intestinal barrier. Correlation analysis showed that spermidine and indole levels were significantly negatively correlated with liver injury-related parameters and positively correlated with the intestinal species B. animalis enriched by DHP. Overall, this study confirmed that DHP prevented liver injury by regulating intestinal microbiota dysbiosis and fecal metabolites.

Research trends and prospects on brain metastasis from breast cancer: A bibliometric analysis.

Introduction: Brain metastasis is the terminal event of breast cancer with poor prognoses. Therefore, this article aimed to provide an updated summary on the development, hotspots, and research trends of brain metastasis from breast cancer based on bibliometric analysis. Method: Publications on breast cancer with brain metastasis retrieved from the Web of Science Core Collection. CiteSpace, VOSviewer, and other online bibliometric analysis platforms were used to analyze and visualize the result. Result: In totality, 693 researchers from 3,623 institutions across 74 counties and regions published a total of 2,790 papers in 607 journals. There was a noticeable increase in publications in 2006. The United States was the dominant country with the most publications followed by China. University Texas MD Anderson Cancer Center was the most productive institution, while Dana Farber Cancer Institution was the most cited. Journal of Neuro-Oncology published the most papers, while Journal of Clinical Oncology ranked first based on cocited analysis. Nancy U. Lin was the most productive and cited author with high influence. There was a focus on basic research, clinical trials, local therapy, treatment optimization, and epidemiological studies regarding brain metastases from breast cancer. References focused on pathogenesis, prevention, treatment, and prognosis were cited most frequently, among which the clinical trial of novel treatment attracted most attention from researchers. Reference citation burst detection suggested that new therapies such as the novel tyrosine kinase inhibitor and antibody-drug conjugate may lead the research trends in the future. Conclusion: High-income countries contributed more to the field of breast cancer with brain metastasis, while developing countries like China developed quickly. Furthermore, the success of novel therapies in recent years may lead to the new era of treatment of breast cancer with brain metastasis in the future.

Delayed improvements in visual memory task performance among chronic schizophrenia patients after high-frequency repetitive transcranial magnetic stimulation.

BACKGROUND: Cognitive impairments are core characteristics of schizophrenia, but are largely resistant to current treatments. Several recent studies have shown that high-frequency repetitive transcranial magnetic stimulation (rTMS) of the left dor-solateral prefrontal cortex (DLPFC) can reduce negative symptoms and improve certain cognitive deficits in schizophrenia patients. However, results are inconsistent across studies. AIM: To examine if high-frequency rTMS of the DLPFC can improve visual memory deficits in patients with schizophrenia. METHODS: Forty-seven chronic schizophrenia patients with severe negative symptoms on stable treatment regimens were randomly assigned to receive active rTMS to the DLPFC (n = 25) or sham stimulation (n = 22) on weekdays for four consecutive weeks. Patients performed the pattern recognition memory (PRM) task from the Cambridge Neuropsychological Test Automated Battery at baseline, at the end of rTMS treatment (week 4), and 4 wk after rTMS treatment (week 8). Clinical symptoms were also measured at these same time points using the Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS). RESULTS: There were no significant differences in PRM performance metrics, SANS total score, SANS subscores, PANSS total score, and PANSS subscores between active and sham rTMS groups at the end of the 4-wk treatment period, but PRM performance metrics (percent correct and number correct) and changes in these metrics from baseline were significantly greater in the active rTMS group at week 8 compared to the sham group (all P < 0.05). Active rTMS treatment also significantly reduced SANS score at week 8 compared to sham treatment. Moreover, the improvement in visual memory was correlated with the reduction in negative symptoms at week 8. In contrast, there were no between-group differences in PANSS total score and subscale scores at either week 4 or week 8 (all P > 0.05). CONCLUSION: High-frequency transcranial magnetic stimulation improves visual memory and reduces negative symptoms in schizophrenia, but these effects are delayed, potentially due to the requirement for extensive neuroplastic changes within DLPFC networks.

Baseline serum uric acid level is associated with progression-free survival, disease control rate, and safety in postoperative patients with colorectal cancer treated by FOLFOX, FOLFIRI, or XELOX.

Background: High serum uric acid (SUA) levels increase the risk of overall cancer morbidity and mortality, particularly for digestive malignancies. Nevertheless, the correlation between SUA level and clinical outcomes of the postoperative patients with colorectal cancer (CRC) treated by chemotherapy is unclear. This study aimed at exploring the relationship between baseline SUA level and progression-free survival (PFS), disease control rate (DCR), and safety in postoperative CRC patients receiving chemotherapy. Patients and Methods: We conducted a retrospective study to evaluate the relationship between baseline SUA level and PFS, DCR, and incidence of serious adverse events of 736 postoperative CRC patients treated with FOLFOX, FOLFIRI or XELOX at our center. Results: Data from our center suggested that high baseline SUA level is linked to poor PFS in non-metastatic CRC patients using FOLFOX (HR=2.59, 95%CI: 1.29-11.31, p=0.018) and in male patients using FOLFIRI (HR=3.77, 95%CI: 1.57-39.49, p=0.012). In patients treated by FOLFIRI, a high SUA is also linked to a low DCR (p=0.035). In patients using FOLFOX, high baseline SUA level is also linked to a high incidence of neutropenia (p=0.0037). For patients using XELOX, there is no significant correlation between SUA level and PFS, effectiveness, or safety. Conclusions: These findings imply that a high SUA level is a promising biomarker associated with poor PFS, DCR and safety of postoperative CRC patients when treated with FOLFOX or FOLFIRI.

Structural, Electronic, and Physical Properties of a New Layered Cr-Based Oxyarsenide Sr2Cr2AsO3.

We report synthesis, crystal structure, and physical properties of Sr2Cr2AsO3. The new compound crystallizes in a Sr2GaO3CuS-type structure with two distinct Cr sites, Cr(1) in the perovskite-like block layers of "Sr3Cr2O6" and Cr(2) in the ThCr2Si2-type layers of "SrCr2As2". An inter-block-layer charge transfer is explicitly evidenced, which dopes electrons in the CrO2 planes and simultaneously dopes holes into the CrAs layers. Measurements of electrical resistivity, magnetization, and specific heat, in combination with density-functional theoretical calculations, indicate that the title material is an antiferromagnetic metal. The Cr(2) magnetic moments in the CrAs layers order at 420 K, while the Cr(1) spins in the CrO2 planes show quasi-two-dimensional magnetism with long-range ordering below 80 K. Both Néel temperatures are significantly reduced, compared with those of the cousin material Sr2Cr3As2O2, probably due to the intrinsic charge-carrier doping. Complex re-entrant magnetic transitions with a huge magnetic hysteresis were observed at low temperatures.

A coupled study of ecological security and land use change based on GIS and entropy method-a typical region in Northwest China, Lanzhou.

Due to rapid population growth, industrialization, and urbanization, it is particularly important to address the increasingly serious ecological security issues in the process of urbanization, while it is important to grasp the impact of changes in land use structure on ecological security for scientific planning and to aid decision-making. As a typical valley basin industrialized city in northwest China, Lanzhou has complex geomorphology and climate with distinct regional characteristics, and the relationship between land use and ecological security is complex. In order to understand the current status and influencing factors of ecological security in various regions of Lanzhou, and to explore the intrinsic connection between ecological security and land use, this study constructed an ecological security evaluation index system based on the pressure-state-response (PSR) model with 14 secondary factors including natural, social, and economic factors. Based on the entropy method, GIS was used to analyze the trend of ecological security in each district and to clarify the coupling relationship between ecological security and land use change in Lanzhou City. The results show that the ecological security index (ESI) of Xigu District, a typical heavy industrial area, increased from 0.26 to 0.35, and the ESI of Yuzhong County, an agricultural development area, increased from 0.51 to 0.55 from 2000 to 2017. Low ESI was mainly distributed in areas with developed heavy industry, while high ESI was mainly found in areas with favorable natural conditions and mainly agricultural development. Economic factors were the leading factors affecting the ecological security of Lanzhou. In general, changes in land use structure and ecological security were inextricably linked, and the two influence and interact with each other. These results could provide some reference for the study of ecological security development and land use change in typical river valley cities and also provide a new path for other cities to study ecological security and the conservation of the ecological environment.

A Web of Science-based scientometric analysis about mammalian target of rapamycin signaling pathway in kidney disease from 1986 to 2020.

BACKGROUND: The mammalian target of rapamycin (mTOR) signaling pathway is vital for the regulation of cell metabolism, growth and proliferation in the kidney. This study aims to show current research focuses and predict future trends about mTOR pathway in kidney disease by the methods of scientometric analysis. METHODS: We referred to publications from the Web of ScienceTM Core Collection (WoSCC) Database. Carrot2, VOSviewer and CiteSpace programs were applied to evaluate the distribution and contribution of authors, institutes and countries/regions of extensive bibliographic metadata, show current research focuses and predict future trends in kidney disease's area. RESULTS: Until July 10, 2020, there are 2,585 manuscripts about mTOR signaling pathway in kidney disease in total and every manuscript is cited 27.39 times on average. The big name of course is the United States. Research hot spots include "diabetic nephropathy", "kidney transplantation", "autosomal dominant polycystic kidney disease", "tuberous sclerosis complex", "renal cell carcinoma" and "autophagy". Seven key clusters are detected, including "kidney transplantation", "autosomal dominant polycystic kidney disease", "renal transplantation", "renal cell carcinoma", "hamartin", "autophagy" and "tuberous sclerosis complex". CONCLUSIONS: Diabetic nephropathy, kidney transplantation, autosomal dominant polycystic kidney disease, tuberous sclerosis complex, renal cell carcinoma and autophagy are future research hot spots by utilizing scientometric analysis. In the future, it is necessary to research these fields.

Comprehensive chemical profiling of Yindan Xinnaotong soft capsule and its neuroprotective activity evaluation in vitro.

Discovering effective combinational components (ECCs) and quality control markers of TCMs is still facing challenges because the holistic healing system comprises hundreds of compounds. Here, taking Yindan Xinnaotong soft capsule (YDXNT), a TCMs preparation composed by 8 herbs, as a case, a strategy that integrated multiple chromatographic analysis and bioactivity assay was proposed for potential ECCs of neuroprotection discovery. Firstly, ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF MS) and gas chromatography-mass spectrometry (GC-MS) were applied for comprehensive profiling of the chemical constituents in YDXNT. Given the fact that the complex matrix interference makes it more difficult to identify potentially active compounds, we proposed a structure-diagnostic ions-oriented strategy to remove interference ions from the raw UHPLC-MS data. The proposed strategy consisted of different filtering methods, including diagnostic fragment ions filtering (DFIF), mass defect filtering (MDF) and neutral loss (NL). Using this strategy, a total of 124 compounds were rapidly identified. Among them, 62 non-volatile and 5 volatile constituents in 30 batches of YDXNT were quantified by UHPLC tandem triple quadrupole mass spectrometry (QQQ-MS) and GC-MS methods, respectively. In order to facilitate the quality control of YDXNT, candidate ECCs were selected based on the threshold setting of absolute -contents, and their neuroprotective effects were examined. Finally, a combination of 16 compounds, accounts for 2.80% (w/w) of original YDXNT, was identified as its potential ECCs, which could be considered for the improvement of quality standardization of YDXNT.

V2Te2O: A Two-Dimensional van der Waals Correlated Metal.

A metastable vanadium oxytelluride V2Te2O is prepared via a topochemical deintercalation of interlayer Rb+ cations in Rb1-δV2Te2O. The new ternary mixed-anion compound crystallizes in a body-centered tetragonal lattice with a = 3.9282(1) Å and c = 13.277(5) Å, containing V2O square nets that are sandwiched by Te-atomic sheets. The charge-neutral [V2OTe2] block layers stack along the c axis with van der Waals forces, which shows a metallic behavior with a dominant T2 dependence for resistivity at low temperatures. The electronic specific-heat coefficient reaches 33.9 mJ K-2 mol-1, ∼4 times that of the electronic structure calculations, suggesting a significant electron-mass renormalization. The electron correlation effect is concurrently demonstrated by the Wilson and Kadowaki-Woods ratios. Neither charge/spin-density wave nor superconductivity was observed down to 0.03 K.

Strong binding and fluorescence sensing of bisphosphonates by guanidinium-modified calix[5]arene.

Based on the indicator displacement assay (IDA) approach, we herein report the fluorescence "switch-on" sensing and quantitative detection of bisphosphonates (BPs), a class of drugs extensively used in the treatment of patients with various skeletal diseases. Guanidinium-modified calix[5]arene (GC5A) affords strong binding on the micromolar to nanomolar level towards BPs dominantly via multiple salt bridge interactions, which was evaluated by fluorescence competitive titrations. Fluorescent IDA enables the highly sensitive and label-free detection of BPs in buffer solution, and more importantly, in artificial urine. Calibration lines were therefore set up in untreated artificial urine, allowing for quantifying the concentrations of BPs in the biologically relevant low range.

[Effects of Mushroom Residue Application Rates on Net Greenhouse Gas Emissions in the Purple Paddy Soil].

China is the leading country for production of edible mushrooms and also outputs numerous mushroom residues. The recycling of mushroom residue can solve environmental pollution problems, provide nutrients for the farmland, and play an important role in reducing greenhouse gas emissions and increasing soil carbon sequestration capacity. In order to investigate the effects of mushroom residue amounts on net greenhouse gas emissions in purple paddy soil, potted experiments using static opaque chamber and gas chromatography methods were used to study the changes of greenhouse gases, soil carbon sequestration, and net greenhouse gas emissions (NGHGE) in the paddy soil with five treatments: no fertilizer (CK), conventional fertilization (NPK), 9 t·hm-2 mushroom residue+NPK (LM), 18 t·hm-2 mushroom residue+NPK (MM), and 36 t·hm2 mushroom residue+NPK (HM) from March 2017 to September 2017.The results showed that: ① The greenhouse gas emissions (including CH4, CO2, and N2O) increased with increasing additions of mushroom residue. The emissions of CH4 from highest to lowest followed: HM > MM > LM≈NPK > CK. The HM treatment significantly increased the CH4 emission flux (P<0.01) more than the other treatments and showed an obvious single peak curve, while the CH4 emission flux with the LM treatment showed a bimodal curve, and the MM treatment showed a multiple peak curve. The CO2 emission flux followed: MM > NPK≈LM > HM > CK; and the curves for the LM, MM, and HM treatments were a single peak curve, bimodal curve, and multiple peak curve, respectively. The N2O cumulative emission from the NPK treatment was significantly higher than with the other treatments. The N2O emission flux of the NPK treatment was a bimodal curve and that of the HM treatment was a single peak curve, while the N2O emission flux of treatments LM and MM showed multiple peak curves. ② The carbon sequestration capacity with the LM treatment was lower than that of the other treatments and that from the MM treatment was the highest. The carbon sequestration capacity of the MM treatment increased by 59.2% compared to that of the NPK treatment and increased by 87.79% and 65.65% compared to that of the LM and HM treatments. The LM treatment has the highest carbon sequestration capacity, which was higher than that of the NPK and MM treatments and about 2.1 times greater than the CK treatment and HM treatment. ③ The minimum NGHGE value was -490.29 kg·hm-2 for the whole rice production period, and 18 t·hm-2 mushroom residue applied to the soil was the best way to reduce net greenhouse gas emissions in purple paddy soil.

A fast and accurate method for the identification of peroxidase inhibitors from Radix Salvia Miltiorrhizae by on-flow biochemical assay coupled with LC/Q-TOF-MS: comparison with ultrafiltration-based affinity selection.

Development of fast and accurate methods to discover lead compounds for drug candidates is highly important. In this study, a reliable and effective post-column on-flow biochemical assay (POBA) was established to screen potent peroxidase inhibitors from complex chemical mixtures (e.g., natural product extracts). Multiple factors such as flow rate, organic phase, detection wavelength, and reaction coil were carefully investigated. To better understand the features of POBA, another emerging technology of ultrafiltration LC-MS was used for comparison. The result showed that POBA had advantages in saving time, avoiding false positives, and improving the accuracy. To illustrate the practicality of the method, Radix Salvia Miltiorrhizae, a traditional herb for cardiovascular disease treatment, was applied as the research objective. Finally, six compounds including tanshinol, protocatechuic aldehyde, salvianolic acid D, rosmarinic acid, lithospermic acid, and salvianolic acid B were determined as novel peroxidase inhibitors. Their bioactivities were validated by microplate-based assay, molecular docking, and pharmacophore modeling. This study demonstrates a great potential of POBA in the efficient and accurate discovery of drug candidates. Graphical abstract Compared with a classical method of ultrafiltration LC-MS, the newly developed method of on-flow bioassay shows advantages in saving time, avoiding false positives and improving the accuracy.

A Zebrafish Heart Failure Model for Assessing Therapeutic Agents.

Heart failure is a leading cause of death and the development of effective and safe therapeutic agents for heart failure has been proven challenging. In this study, taking advantage of larval zebrafish, we developed a zebrafish heart failure model for drug screening and efficacy assessment. Zebrafish at 2 dpf (days postfertilization) were treated with verapamil at a concentration of 200 µM for 30 min, which were determined as optimum conditions for model development. Tested drugs were administered into zebrafish either by direct soaking or circulation microinjection. After treatment, zebrafish were randomly selected and subjected to either visual observation and image acquisition or record videos under a Zebralab Blood Flow System. The therapeutic effects of drugs on zebrafish heart failure were quantified by calculating the efficiency of heart dilatation, venous congestion, cardiac output, and blood flow dynamics. All 8 human heart failure therapeutic drugs (LCZ696, digoxin, irbesartan, metoprolol, qiliqiangxin capsule, enalapril, shenmai injection, and hydrochlorothiazide) showed significant preventive and therapeutic effects on zebrafish heart failure (p < 0.05, p < 0.01, and p < 0.001) in the zebrafish model. The larval zebrafish heart failure model developed and validated in this study could be used for in vivo heart failure studies and for rapid screening and efficacy assessment of preventive and therapeutic drugs.

Label-free pharmacological profiling based on dynamic mass redistribution for characterization and authentication of hazardous natural products.

Natural products are becoming increasingly popular in multiple fields involving medicines, foods and beverages. However, due to the frequent occurrence of poisoning incidents, their toxicity and safety have caused a serious concern. Here we report a method of biosensor-based two-phase pharmacological profiling (BTPP) for discovery, monitor and control of receptor-targeted natural products. BTPP uses a resonant waveguide grating biosensor for label-free and non-invasive detection of intracellular dynamic mass redistribution (DMR), a phenomenon caused by protein relocalization after receptors receiving stimulation from toxicants. The method can not only facilitate the identification of hazardous materials but also quantify their bioactivity by EC50. As a proof of concept, the method was successfully applied to recognize Daturae Flos (DF), an herb that can antagonize muscarinic acetylcholine M2 receptor and further cause poisoning, from other easily confused species. BTPP combined with high performance liquid chromatography revealed that scopolamine and hyoscyamine in DF were the key marker compounds. Moreover, the method accurately picked out 2 M2 receptor antagonists from 25 natural compounds, displaying its potential in high-throughput screening. This study provides a systematic illustration about the establishment, applicability and advantages of BTPP, which contributes to the safety assessment of natural products in related fields.

Superconductivity at 35 K by self doping in RbGd2Fe4As4O2.

We report synthesis, crystal structure and physical properties of a novel quinary compound RbGd2Fe4As4O2. The new iron oxyarsenide is isostructural to the fluo-arsenide KCa2Fe4As4F2, both of which contain separate double Fe2As2 layers that are self hole-doped in the stoichiometric composition. Bulk superconductivity at [Formula: see text] K is demonstrated by the measurements of electrical resistivity, dc magnetic susceptibility and heat capacity. An exceptionally high value of the initial slope of the upper critical field ([Formula: see text]d[Formula: see text]/d[Formula: see text] [Formula: see text] T K-1) is measured for the polycrystalline sample.

Integration of Multiple Analytical and Computational Tools for the Discovery of High-Potency Enzyme Inhibitors from Herbal Medicines.

Herbal medicines (HMs) are an important source of drugs. In this study, an efficient strategy integrating ultrafiltration LC-MS, microplate bioassays, and molecular docking was proposed to screen high-potency enzyme inhibitors from HMs. Using this strategy, the structure-activity relationships (SARs) including binding-affinity-based SAR, enzymatic-activity-based SAR, and structural-complementarity-based SAR of compounds in an HM can be analyzed to provide abundant information for drug discovery. A prominent advantage of the approach is that it offers a multidimensional perspective to understand enzyme-ligand interactions, which could help to avoid false-positive screening results brought by a single method. By using xanthine oxidase (XOD) as an illustrative case, two types of potent XOD inhibitors, including flavones and coumarins, were successfully screened out from an HM of Ginkgo biloba. The study is expected to set a solid foundation for multidisciplinary cooperation in drug discovery.

A strategy for screening active lead compounds and functional compound combinations from herbal medicines based on pharmacophore filtering and knockout/knockin chromatography.

Screening and deciphering active natural products of herbal medicines are of great importance for modern drug discovery. In this study, a novel strategy was proposed to rapidly filter ineffective compounds and target the most potential leads. The aim is to answer the key question of what components are responsible for the holistic bioactivity of an herbal product. To support the strategy, the pharmacophore-guided knockout/knockin chromatography was established for the first time. The greatest advantage of this method is that any interesting components could be automatically fished or knocked out. The method validation shows that the herbal extract was accurately reconstructed according to the experimental design. By combining with bioactivity assays, we demonstrated that "functional compound combination (FCC)", which is the core and indispensable effective part, could be discovered from an herbal medicine and suitable as marker compounds for quality control. The applicable objects of the strategy include single herbs, herbal formulas and commercially herbal preparations. As an illustrative case study, the strategy was successfully applied to simultaneously determine active leads and the FCC in Dan-Qi formula which shows excellent free radical scavenging activity. The potential mechanisms of compounds in Dan-Qi formula reacting with three different free radicals were systematically reported for the first time. This strategy was expected to unveil the mystery of herbal medicines and inspire a natural product-based drug discovery.

Superconductivity in KCa2Fe4As4F2 with Separate Double Fe2As2 Layers.

We report the synthesis, crystal structure, and physical properties of a quinary iron arsenide fluoride, KCa2Fe4As4F2. The new compound crystallizes in a body-centered tetragonal lattice (space group I4/mmm, a = 3.8684(2) Å, c = 31.007(1) Å, Z = 2) that contains double Fe2As2 conducting layers separated by insulating Ca2F2 layers. Our measurements of electrical resistivity, direct-current magnetic susceptibility, and heat capacity demonstrate bulk superconductivity at 33 K in KCa2Fe4As4F2.