Dual-Intermetallic Heterostructure on Hierarchical Nanoporous Metal for Highly Efficient Alkaline Hydrogen Electrocatalysis.

Constructing well-defined active multisites is an effective strategy to break linear scaling relationships to develop high-efficiency catalysts toward multiple-intermediate reactions. Here, dual-intermetallic heterostructure composed of tungsten-bridged Co3W and WNi4 intermetallic compounds seamlessly integrated on hierarchical nanoporous nickel skeleton is reported as a high-performance nonprecious electrocatalyst for alkaline hydrogen evolution and oxidation reactions. By virtue of interfacial tungsten atoms configuring contiguous multisites with proper adsorptions of hydrogen and hydroxyl intermediates to accelerate water dissociation/combination and column-nanostructured nickel skeleton facilitating electron and ion/molecule transportations, nanoporous nickel-supported Co3W-WNi4 heterostructure exhibits exceptional hydrogen electrocatalysis in alkaline media, with outstanding durability and impressive catalytic activities for hydrogen oxidation reaction (geometric exchange current density of ≈6.62 mA cm-2) and hydrogen evolution reaction (current density of ≈1.45 A cm-2 at overpotential of 200 mV). Such atom-ordered intermetallic heterostructure alternative to platinum group metals shows genuine potential for hydrogen production and utilization in hydroxide-exchange-membrane water electrolyzers and fuel cells.

One-Pot Direct Mechanochemical Silicon Replacement of Sodium Fluorosilicate into Sodium Fluorozirconate and Functionalization of Graphite for Enhanced Sodium-Ion Storage.

Efficient sodium ion storage in graphite is as yet unattainable, because of the thermodynamic instability of sodium ion intercalates-graphite compounds. In this work, sodium fluorozirconate (Na3ZrF7, SFZ) functionalized graphite (SFZ-G) is designed and prepared by the in situ mechanochemical silicon (Si) replacement of sodium fluorosilicate (Na2SiF6, SFS) and functionalization of graphite at the same time. During the mechanochemical process, the atomic Si in SFS is directly replaced by atomic zirconium (Zr) from the zirconium oxide (ZrO2) balls and container in the presence of graphite, forming SFZ-G. The resulting SFZ-G, working as an anode material for sodium ion storage, shows a significantly enhanced capacity of 418.7 mAh g-1 at 0.1 C-rate, compared to pristine graphite (35 mAh g-1) and simply ball-milled graphite (BM-G, 200 mAh g-1). In addition, the SFZ-G exhibits stable sodium-ion storage performance with 86% of its initial capacity retention after 1000 cycles at 2.0 C-rate.

Scalable Design of Ru-Embedded Carbon Fabric Using Conventional Carbon Fiber Processing for Robust Electrocatalysts.

Metal-carbon composites are extensively utilized as electrochemical catalysts but face critical challenges in mass production and stability. We report a scalable manufacturing process for ruthenium surface-embedded fabric electrocatalysts (Ru-SFECs) via conventional fiber/fabric manufacturing. Ru-SFECs have excellent catalytic activity and stability toward the hydrogen evolution reaction, exhibiting a low overpotential of 11.9 mV at a current density of 10 mA cm-2 in an alkaline solution (1.0 M aq KOH solution) with only a slight overpotential increment (6.5%) after 10,000 cycles, whereas under identical conditions, that of commercial Pt/C increases 6-fold (from 1.3 to 7.8 mV). Using semipilot-scale equipment, a protocol is optimized for fabricating continuous self-supported electrocatalytic electrodes. Tailoring the fiber processing parameters (tension and temperature) can optimize the structural development, thereby achieving good catalytic performance and mechanical integrity. These findings underscore the significance of self-supporting catalysts, offering a general framework for stable, binder-free electrocatalytic electrode design.

In Situ Engineering Multifunctional Active Sites of Ruthenium-Nickel Alloys for pH-Universal Ampere-Level Current-Density Hydrogen Evolution.

Developing robust non-platinum electrocatalysts with multifunctional active sites for pH-universal hydrogen evolution reaction (HER) is crucial for scalable hydrogen production through electrochemical water splitting. Here ultra-small ruthenium-nickel alloy nanoparticles steadily anchored on reduced graphene oxide papers (Ru-Ni/rGOPs) as versatile electrocatalytic materials for acidic and alkaline HER are reported. These Ru-Ni alloy nanoparticles serve as pH self-adaptive electroactive species by making use of in situ surface reconstruction, where surface Ni atoms are hydroxylated to produce bifunctional active sites of Ru-Ni(OH)2 for alkaline HER, and selectively etched to form monometallic Ru active sites for acidic HER, respectively. Owing to the presence of Ru-Ni(OH)2 multi-site surface, which not only accelerates water dissociation to generate reactive hydrogen intermediates but also facilitates their recombination into hydrogen molecules, the self-supported Ru90Ni10/rGOP hybrid electrode only takes overpotential of as low as ≈106 mV to deliver current density of 1000 mA cm-2, and maintains exceptional stability for over 1000 h in 1 m KOH. While in 0.5 m H2SO4, the Ru90Ni10/rGOP hybrid electrode exhibits acidic HER catalytic behavior comparable to commercially available Pt/C catalyst due to the formation of monometallic Ru shell. These electrochemical behaviors outperform some of the best Ru-based catalysts and make it attractive alternative to Pt-based catalysts toward highly efficient HER.

Lamellar Nanoporous Metal/Intermetallic Compound Heterostructure Regulating Dendrite-Free Zinc Electrodeposition for Wide-Temperature Aqueous Zinc-Ion Battery.

Aqueous zinc-ion batteries are attractive post-lithium battery technologies for grid-scale energy storage because of their inherent safety, low cost and high theoretical capacity. However, their practical implementation in wide-temperature surroundings persistently confronts irregular zinc electrodeposits and parasitic side reactions on metal anode, which leads to poor rechargeability, low Coulombic efficiency and short lifespan. Here, this work reports lamellar nanoporous Cu/Al2Cu heterostructure electrode as a promising anode host material to regulate high-efficiency and dendrite-free zinc electrodeposition and stripping for wide-temperatures aqueous zinc-ion batteries. In this unique electrode, the interconnective Cu/Al2Cu heterostructure ligaments not only facilitate fast electron transfer but work as highly zincophilic sites for zinc nucleation and deposition by virtue of local galvanic couples while the interpenetrative lamellar channels serving as mass transport pathways. As a result, it exhibits exceptional zinc plating/stripping behaviors in aqueous hybrid electrolyte of diethylene glycol dimethyl ether and zinc trifluoromethanesulfonate at wide temperatures ranging from 25 to -30 °C, with ultralow voltage polarizations at various current densities and ultralong lifespan of >4000 h. The outstanding electrochemical properties enlist full cell of zinc-ion batteries constructed with nanoporous Cu/Al2Cu and ZnxV2O5/C to maintain high capacity and excellent stability for >5000 cycles at 25 and -30 °C.

Out-of-Plane Single-Copper-Site Catalysts for Room-Temperature Benzene Oxidation.

Crafting single-atom catalysts (SACs) that possess "just right" modulated electronic and geometric structures, granting accessible active sites for direct room-temperature benzene oxidation is a coveted objective. However, achieving this goal remains a formidable challenge. Here, we introduce an innovative in situ phosphorus-immitting strategy using a new phosphorus source (phosphorus nitride, P3N5) to construct the phosphorus-rich copper (Cu) SACs, designated as Cu/NPC. These catalysts feature locally protruding metal sites on a nitrogen (N)-phosphorus (P)-carbon (C) support (NPC). Rigorous analyses, including X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS), validate the coordinated bonding of nitrogen and phosphorus with atomically dispersed Cu sites on NPC. Crucially, systematic first-principles calculations, coupled with the climbing image nudged-elastic-band (CI-NEB) method, provide a comprehensive understanding of the structure-property-activity relationship of the distorted Cu-N2P2 centers in Cu/NPC for selective oxidation of benzene to phenol production. Interestingly, Cu/NPC has shown more energetically favorable C-H bond activation compared to the benchmark Cu/NC SACs in the direct oxidation of benzene, resulting in outstanding benzene conversion (50.3 %) and phenol selectivity (99.3 %) at room temperature. Furthermore, Cu/NPC achieves a remarkable turnover frequency of 263 h-1 and mass-specific activity of 35.2 mmol g-1 h-1, surpassing the state-of-the-art benzene-to-phenol conversion catalysts to date.

Dynamic Molecular Interphases Regulated by Trace Dual Electrolyte Additives for Ultralong-Lifespan and Dendrite-Free Zinc Metal Anode.

Metallic zinc is a promising anode material for rechargeable aqueous multivalent metal-ion batteries due to its high capacity and low cost. However, the practical use is always beset by severe dendrite growth and parasitic side reactions occurring at anode/electrolyte interface. Here we demonstrate dynamic molecular interphases caused by trace dual electrolyte additives of D-mannose and sodium lignosulfonate for ultralong-lifespan and dendrite-free zinc anode. Triggered by plating and stripping electric fields, the D-mannose and lignosulfonate species are alternately and reversibly (de-)adsorbed on Zn metal, respectively, to accelerate Zn2+ transportation for uniform Zn nucleation and deposition and inhibit side reactions for high Coulombic efficiency. As a result, Zn anode in such dual-additive electrolyte exhibits highly reversible and dendrite-free Zn stripping/plating behaviors for >6400 hours at 1 mA cm-2, which enables long-term cycling stability of Zn||ZnxMnO2 full cell for more than 2000 cycles.

Recent Advances in Iridium-based Electrocatalysts for Acidic Electrolyte Oxidation.

Ongoing research to develop advanced electrocatalysts for the oxygen evolution reaction (OER) is needed to address demand for efficient energy conversion and carbon-free energy sources. In the OER process, acidic electrolytes have higher proton concentration and faster response than alkaline ones, but their harsh strongly acidic environment requires catalysts with greater corrosion and oxidation resistance. At present, iridium oxide (IrO2) with its strong stability and excellent catalytic performance is the catalyst of choice for the anode side of commercial PEM electrolysis cells. However, the scarcity and high cost of iridium (Ir) and the unsatisfactory activity of IrO2 hinder industrial scale application and the sustainable development of acidic OER catalytic technology. This highlights the importance of further research on acidic Ir-based OER catalysts. In this review, recent advances in Ir-based acidic OER electrocatalysts are summarized, including fundamental understanding of the acidic OER mechanism, recent insights into the stability of acidic OER catalysts, highly efficient Ir-based electrocatalysts, and common strategies for optimizing Ir-based catalysts. The future challenges and prospects of developing highly effective Ir-based catalysts are also discussed.

New aporphine alkaloids with antitumor activities from the roots of Thalictrum omeiense.

Two new aporphine alkaloids, 6aR-2'-(3-oxobutenyl)-thaliadin (1) and N-methylthalisopynine (2), along with ten known analogs (3-12), were isolated from the roots of Thalictrum omeiense W. T. Wang et S. H. Wang. Their structures were determined by extensive spectroscopic and X-ray crystallographic analyses. Compounds 1-7 and 9-12 were tested for their antiproliferative effects in vitro against two human cancer cell lines (A549 and MCF-7). Among them, compounds 1, 3, and 7 exhibited moderate inhibitory activity against the tested cell lines with IC50 values ranging from 23.73 to 34.97 µM.

Benzoquinone-Lubricated Intercalation in Manganese Oxide for High-Capacity and High-Rate Aqueous Aluminum-Ion Battery.

Aqueous aluminum-ion batteries are attractive post-lithium battery technologies for large-scale energy storage in virtue of abundant and low-cost Al metal anode offering ultrahigh capacity via a three-electron redox reaction. However, state-of-the-art cathode materials are of low practical capacity, poor rate capability, and inadequate cycle life, substantially impeding their practical use. Here layered manganese oxide that is pre-intercalated with benzoquinone-coordinated aluminum ions (BQ-AlxMnO2) as a high-performance cathode material of rechargeable aqueous aluminum-ion batteries is reported. The coordination of benzoquinone with aluminum ions not only extends interlayer spacing of layered MnO2 framework but reduces the effective charge of trivalent aluminum ions to diminish their electrostatic interactions, substantially boosting intercalation/deintercalation kinetics of guest aluminum ions and improving structural reversibility and stability. When coupled with Zn50Al50 alloy anode in 2 m Al(OTf)3 aqueous electrolyte, the BQ-AlxMnO2 exhibits superior rate capability and cycling stability. At 1 A g-1, the specific capacity of BQ-AlxMnO2 reaches ≈300 mAh g-1 and retains ≈90% of the initial value for more than 800 cycles, along with the Coulombic efficiency of as high as ≈99%, outperforming the AlxMnO2 without BQ co-incorporation.

Efficacy of bronchoalveolar lavage combined with prone positioning in children with Mycoplasma pneumoniae pneumonia and atelectasis: a prospective randomized controlled study / 中国当代儿科杂志

OBJECTIVES@#To study the efficacy of bronchoalveolar lavage (BAL) combined with prone positioning in children with Mycoplasma pneumoniae pneumonia (MPP) and atelectasis and its effect on pulmonary function.@*METHODS@#A prospective study was conducted on 94 children with MPP and atelectasis who were hospitalized in Ordos Central Hospital of Inner Mongolia from November 2020 to May 2023. The children were randomly divided into a treatment group and a control group, with 47 children in each group. The children in the treatment group were given conventional treatment, BAL, and prone positioning, and those in the control group were given conventional treatment and BAL. The two groups were compared in terms of fever, pulmonary signs, length of hospital stay, lung recruitment, and improvement in pulmonary function.@*RESULTS@#Compared with the control group, the treatment group had significantly shorter time to improvement in pulmonary signs and length of hospital stay and a significantly higher rate of lung recruitment on day 7 of hospitalization, on the day of discharge, and at 1 week after discharge (P<0.05). Compared with the control group, the treatment group had significantly higher levels of forced vital capacity (FVC) as a percentage of the predicted value, forced expiratory volume (FEV) in 1 second as a percentage of the predicted value, ratio of FEV in 1 second to FVC, forced expiratory flow at 50% of FVC as a percentage of the predicted value, forced expiratory flow at 75% of FVC as a percentage of the predicted value, and maximal mid-expiratory flow as a percentage of the predicted value on the day of discharge and at 1 week after discharge (P<0.05). There was no significant difference in the time for body temperature to return to normal between the two groups (P>0.05).@*CONCLUSIONS@#In the treatment of children with MPP and atelectasis, BAL combined with prone positioning can help to shorten the time to improvement in pulmonary signs and the length of hospital stay and promote lung recruitment and improvement in pulmonary function.

Clinical Characteristics and Potential Risk Factors Analysis of Liver Injury Related to Epimedii Folium Preparation / 中国实验方剂学杂志

ObjectiveThis paper aims to analyze the clinical characteristics and medication rationality of liver injury related to Epimedii Folium preparation （EP） and explore the possible risk factors of liver injury， so as to provide a reference for the safe clinical application of Epimedii Folium （EF）. MethodA retrospective analysis was conducted on liver injury cases related to EP from 2012 to 2016. ResultThe number of reported liver injury cases and the proportion of severe cases related to the use of EP show an increasing trend， indicating the objective existence of liver injury caused by EP. There are more cases of liver injury related to EP in women than in men， with an onset age range of 15-91 years old and a median onset age of 60 years old （median onset ages for men and women are 59 and 60 years old， respectively）. The time span from taking EP alone to the occurrence of liver injury is 1-386 days， with a median of 38 days. The time span from taking both EP and Western medicine to the occurrence of liver injury is 1-794 days， with a median of 34 days. EF-related liver injury preparations are mostly composed of traditional Chinese medicines that promote immunity and tonify the liver and kidney， indicating that immune stress in the body may be the mechanism of liver injury caused by the use of EP alone or in combination. There is no increasing trend of toxicity with time or dose in the liver injury caused by EP. By further exploring its risk factors， it is found that patients have unreasonable medication methods such as excessive dosage， repeated use， and multi-drug combination， which may also be one of the important risk factors for EF-related liver injury. ConclusionEP has a certain risk of liver injury and should be emphasized in clinical diagnosis and treatment. Immune stress may be the mechanism of liver injury caused by EP， and in clinical use， it is necessary to be vigilant about the risk of liver injury caused by unreasonable use and combined use with Western medicine.

Rhodium and Carbon Sites with Strong d-p Orbital Interaction for Efficient Bifunctional Catalysis.

Efficient and stable catalysts are highly desired for the electrochemical conversion of hydrogen, oxygen, and water molecules, processes which are crucial for renewable energy conversion and storage technologies. Herein, we report the development of hollow nitrogenated carbon sphere (HNC) dispersed rhodium (Rh) single atoms (Rh1HNC) as an efficient catalyst for bifunctional catalysis. The Rh1HNC was achieved by anchoring Rh single atoms in the HNC matrix with an Rh-N3C1 configuration, via a combination of in situ polymerization and carbonization approach. Benefiting from the strong metal atom-support interaction (SMASI), the Rh and C atoms can collaborate to achieve robust electrochemical performance toward both the hydrogen evolution and oxygen reduction reactions in acidic media. This work not only provides an active site with favorable SMASI for bifunctional catalysis but also brings a strategy for the design and synthesis of efficient and stable bifunctional catalysts for diverse applications.

A Novel Prognostic Model Predicts Outcomes in Non-Metastatic Nasopharyngeal Carcinoma Based on Inflammation, Nutrition, and Coagulation Signature.

Purpose: This study aimed to assess the prognostic and predictive value of a circulating hematological signature (CHS) and to develop a CHS-based nomogram for predicting prognosis and guiding individualized chemotherapy in non-metastatic nasopharyngeal carcinoma (NPC) patients. Patients and Methods: NPC patients were recruited between January 2014 and December 2017 at the Jiangxi Cancer Hospital. The CHS was constructed based on a series of hematological indicators. The nomogram was developed by CHS and clinical factors. Results: A total of 779 patients were included. Three biomarkers were selected by least absolute shrinkage and selection operator regression, including prognostic nutritional index, albumin-to-fibrinogen ratio, and prealbumin-to-fibrinogen ratio, were used to construct the CHS. The patients in the low-CHS group had better 5-year DMFS and OS than those in the high-CHS group in the training (DMFS: 85.0% vs 56.6%, p<0.001; OS: 90.3% vs 65.4%, p<0.001) and validation cohorts (DMFS: 92.3% vs 43.6%, p<0.001; OS: 92.1% vs 65.5%, p<0.001). The nomogram_CHS showed better performance than clinical stage in predicting distant metastasis (concordance index: 0.728 vs 0.646). In the low-TRS (total risk scores) group, the patients received RT alone, CCRT and IC plus CCRT had similar 5-year DMFS and OS (p>0.05). In the middle-TRS group, the patients received RT alone had worse 5-year DMFS (58.7% vs 80.8% vs 90.8%, p=0.002) and OS (75.0% vs 94.1% vs 95.0%, p=0.001) than those received CCRT or IC plus CCRT. In the high-TRS group, the patients received RT alone and CCRT had worse 5-year DMFS (18.6% vs 31.3% vs 81.5%, p<0.001) and OS (26.9% vs 53.2% vs 88.8%, p<0.001) than those received IC plus CCRT. Conclusion: The developed nomogram_CHS had satisfactory prognostic accuracy in NPC patients and may individualize risk estimation to facilitate the identification of suitable IC candidates.

Effects of fine substance content in soil substrate on the formation of artificial cyanobacteria crusts.

The use of artificial cyanobacteria crusts is one of the effective methods to prevention and control of desertification. Soil fine substance is one of the important factors limiting the colonization and growth of artificial cyanobacteria crusts. We compared the growth of artificial cyanobacterial crusts with different fine substance contents by setting the volume ratios of fine substance to quicksand as 0:1, 1:1, 2:1, 4:1 and 1:0. The results showed that the cover of artificial cyanobacteria crusts increased gradually with the increases of fine substance contents, while the contents of chlorophyll a and extracellular polysaccharide firstly increased and then decreased slightly. The optimum growth of artificial cyanobacterial crusts was achieved under the treatment of 4:1 ratio. Under such treatment after 60 days of incubation, artificial cyanobacteria crusts cover was 70%, and the contents of chlorophyll a, loosely bound exopolysaccharide (LB-EPS), tightly bound exopolysaccharide (TB-EPS), and glycocalyx exopolysaccharide (G-EPS) were 17.5, 70.0, 175.0, and 200.0 µg·cm-2, respectively. Increasing the amount of cyanobacteria under the condition of low fine substance content could promote the formation and growth of artificial cyanobacterial crusts (0.5 g of cyanobacteria per petri dish was the optimal). It could provide a new idea for the large-scale culture of artificial cyanobacterial crusts inoculum.

Mechanochemical Ammonia Synthesis: Old is New Again.

Hydrogen is a promising clean energy source, an alternative to fossil fuels, and can potentially play a crucial role in reducing carbon emissions. The transportation and storage of hydrogen are the biggest hurdles to realizing a hydrogen economy. Ammonia is considered to be one of the most promising hydrogen carriers, because of its high hydrogen content and easy liquefaction in mild conditions. To date, ammonia is mostly produced by the 'thermocatalytic' Haber-Bosch process, which requires high temperature and pressure. As a result, it can only produce ammonia in 'centralized' manufacturing systems. Mechanochemistry, a newly emerging method for efficient ammonia synthesis, offers potential advantages over the Haber-Bosch process. Mechanochemical ammonia synthesis under near ambient conditions can be connected with 'localized' sustainable energy systems. In this perspective, the state-of-the-art mechanochemical ammonia synthesis processes will be introduced. Challenges and opportunities are also discussed in relation to its role in a hydrogen economy.

Achieving volatile potassium promoted ammonia synthesis via mechanochemistry.

Potassium oxide (K2O) is used as a promotor in industrial ammonia synthesis, although metallic potassium (K) is better in theory. The reason K2O is used is because metallic K, which volatilizes around 400 °C, separates from the catalyst in the harsh ammonia synthesis conditions of the Haber-Bosch process. To maximize the efficiency of ammonia synthesis, using metallic K with low temperature reaction below 400 °C is prerequisite. Here, we synthesize ammonia using metallic K and Fe as a catalyst via mechanochemical process near ambient conditions (45 °C, 1 bar). The final ammonia concentration reaches as high as 94.5 vol%, which was extraordinarily higher than that of the Haber-Bosch process (25.0 vol%, 450 °C, 200 bar) and our previous work (82.5 vol%, 45 °C, 1 bar).

Lamella-heterostructured nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride electrodes as stable catalysts for oxygen evolution.

Developing robust nonprecious-metal electrocatalysts with high activity towards sluggish oxygen-evolution reaction is paramount for large-scale hydrogen production via electrochemical water splitting. Here we report that self-supported laminate composite electrodes composed of alternating nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride (FeCo/CeO2-xNx) heterolamellas hold great promise as highly efficient electrocatalysts for alkaline oxygen-evolution reaction. By virtue of three-dimensional nanoporous architecture to offer abundant and accessible electroactive CoFeOOH/CeO2-xNx heterostructure interfaces through facilitating electron transfer and mass transport, nanoporous FeCo/CeO2-xNx composite electrodes exhibit superior oxygen-evolution electrocatalysis in 1 M KOH, with ultralow Tafel slope of ~33 mV dec-1. At overpotential of as low as 360 mV, they reach >3900 mA cm-2 and retain exceptional stability at ~1900 mA cm-2 for >1000 h, outperforming commercial RuO2 and some representative oxygen-evolution-reaction catalysts recently reported. These electrochemical properties make them attractive candidates as oxygen-evolution-reaction electrocatalysts in electrolysis of water for large-scale hydrogen generation.

Merging Platinum Single Atoms to Achieve Ultrahigh Mass Activity and Low Hydrogen Production Cost.

Single atom catalysts (SACs) with isolated active sites exhibit the highest reported mass activity for hydrogen evolution catalysis, which is crucial for practical applications. Here, we demonstrate that ultrahigh mass activity can also be achieved by rationally merging the isolated platinum (Pt) active sites in SAC. The catalyst was obtained by the thermodynamically driven diffusing and merging phosphorus-doped carbon (PC) supported Pt single atoms (Pt1@PC) into Pt nanoclusters (PtM@PC). X-ray absorption spectroscopy analysis revealed that the merged nanoclusters exhibit much stronger interactions with the support than the traditional method, enabling more efficient electron transfer. The optimized PtM@PC exhibited an order of magnitude higher mass activity (12.7 A mgPt-1) than Pt1@PC (0.9 A mgPt-1) at an overpotential of 10 mV in acidic media, which is the highest record to date, far exceeding reports for other outstanding SACs. Theoretical study revealed that the collective active sites in PtM@PC exhibit both favorable hydrogen binding energy and fast reaction kinetics, leading to the significantly enhanced mass activity. Despite its low Pt content (2.2 wt %), a low hydrogen production cost of ∼3 USD kg-1 was finally achieved in the full-water splitting at a laboratory scale.

Quality evaluation of Crataegus pinnatifida leaves by fingerprint combined with quantitative analysis of multi-components by single-marker / 中国药房

OBJECTIVE To establish the fingerprint and multi-component content determination method of Crataegus pinnatifida leaves from different producing areas， and to evaluate the quality of C. pinnatifida leaves and screen the differential markers. METHODS Seventy-eight batches of C. pinnatifida leaves were collected from Chengde of Hebei Province， Huludao of Liaoning Province， Yuncheng of Shanxi Province and Linyi of Shandong Province. High-performance liquid chromatography （HPLC） and Similarity Evaluation System for Traditional Chinese Medicine Chromatographic Fingerprints （2012 edition） were used to draw the fingerprints and conduct similarity evaluation. Grey correlation analysis， cluster analysis （CA）， principal component analysis （PCA） and orthogonal partial least squares-discriminant analysis （OPLS-DA） were performed by using SPSS 19.0， MetaboAnalyst 5.0 and SIMCA 14.1 software. The differential markers affecting the quality of C. pinnatifida leaves were screened with variable importance in the projection （VIP） value greater than 1 and the error line not exceeding the origin as the criterion. Using vitexin rhamnoside as an internal reference， the contents of chlorogenic acid， glucosylvitexin， hypericin and isoquercetin in 78 batches of C. pinnatifida leaves were determined by the same HPLC combined with quantitative analysis of multi- components by single-marker （QAMS）， and the results were compared with external standard method. RESULTS Eight common peaks were calibrated in the fingerprints for 78 batches of C. pinnatifida leaves from 4 producing areas. Five known components were identified， including chlorogenic acid （peak 1）， glucosylvitexin （peak 3）， vitexin rhamnoside （peak 4）， hypericin （peak 7） and isoquercetin （peak 8）； their similarities ranged from 0.871 to 0.998. Average relative correlations of samples from Chengde of Hebei Province， Huludao of Liaoning Province， Yuncheng of Shanxi Province and Linyi of Shandong Province were 0.538， 0.528， 0.462 and 0.435， respectively. CA and PCA showed that the samples from Chengde of Hebei Province and Huludao of Liaoning Province were roughly classified into one category， while the samples from Linyi of Shandong Province and Yuncheng of Shanxi Province were roughly classified into one category； VIP values of peak 1， 2， 3 and 5 were all greater than 1. By QAMS， the relative correction factors of chlorogenic acid， glucosylvitexin， hypericin and isoquercetin were 0.401， 0.993， 1.670 and 1.615 （RSD＜2%）. Compared with external standard method， except for isoquercetin in the two batches of samples （S39 and S41）， there was no significant difference in the content of each component in other batches of samples （the relative deviations≤ 5%）. CONCLUSIONS The established fingerprint and QAMS method are simple to operate and can be used to evaluate the quality of C. pinnatifida leaves. The sample from Chengde of Hebei Province is relatively good in quality. Chlorogenic acid （peak 1）， glucosylvitexin （peak 3）， and the corresponding components of peaks 2 and 5 may be differential markers affecting the quality of C. pinnatifida leaves.