Binary Nano-inhalant Formulation of Icariin Enhances Cognitive Function in Vascular Dementia via BDNF/TrkB Signaling and Anti-inflammatory Effects.

Vascular dementia (VaD) has a serious impact on the patients' quality of life. Icariin (Ica) possesses neuroprotective potential for treating VaD, yet its oral bioavailability and blood-brain barrier (BBB) permeability remain challenges. This research introduced a PEG-PLGA-loaded chitosan hydrogel-based binary formulation tailored for intranasal delivery, enhancing the intracerebral delivery efficacy of neuroprotective agents. The formulation underwent optimization to facilitate BBB crossing, with examinations conducted on its particle size, morphology, drug-loading capacity, in vitro release, and biodistribution. Using the bilateral common carotid artery occlusion (BCCAO) rat model, the therapeutic efficacy of this binary formulation was assessed against chitosan hydrogel and PEG-PLGA nanoparticles loaded with Ica. Post-intranasal administration, enhanced cognitive function was evident in chronic cerebral hypoperfusion (CCH) rats. Further mechanistic evaluations, utilizing immunohistochemistry (IHC), RT-PCR, and ELISA, revealed augmented transcription of synaptic plasticity-associated proteins like SYP and PSD-95, and a marked reduction in hippocampal inflammatory markers such as IL-1ß and TNF-α, highlighting the formulation's promise in alleviating cognitive impairment. The brain-derived neurotrophic factor (BDNF)/tropomyosin related kinase B (TrkB) pathway was activated significantly in the binary formulation compared with the other two. Our study demonstrates that the intranasal application of chitosan hydrogel loaded with Ica-encapsulated PEG-PLGA could effectively deliver Ica into the brain and enhance its neuroprotective effect.

Selenium content, chemical composition and volatile components of essential oil and hydrosol from flowers of Cardamine violifolia.

Cardamine violifolia is a unique selenium hyperaccumulating vegetable in China, but its flowers are commonly wasted in large-scale cultivation. To better utilize this resource, this study explored the selenium content, chemical composition, and volatile organic compounds (VOCs) of hydro-distilling essential oil (EO) and hydrosol from C. violifolia flowers. ICP-MS results indicated that the EO and hydrosol contained selenium reaching 13.66±2.82 mg/kg and 0.0084±0.0013 mg/kg, respectively. GC-MS analysis revealed that organic acids, hydrocarbons, and amines were the main components of EO. Additionally, benzyl nitrile, benzaldehyde, benzyl isothiocyanate, benzyl alcohol, megastigmatrienone, and 2-methoxy-4-vinylphenol also existed in considerable amounts. The hydrosol extract had fewer components, mainly amines. HS-SPME-GC-MS corresponded to the composition analysis and aromatic compounds were the prevalent VOCs, while HS-GC-IMS primarily identified C2-C10 molecular alcohols, aldehydes, ethers, and sulfur-containing compounds. This study first described the chemical composition and VOC profiles of EO and hydrosol from selenium hyperaccumulating plant.

The Enhanced Performance of NiCuOOH/NiCu(OH)2 Electrode Using Pre-Conversion Treatment for the Electrochemical Oxidation of Ammonia.

Electrochemical oxidation of ammonia is an attractive process for wastewater treatment, hydrogen production, and ammonia fuel cells. However, the sluggish kinetics of the anode reaction has limited its applications, leading to a high demand for novel electrocatalysts. Herein, the electrode with the in situ growth of NiCu(OH)2 was partially transformed into the NiCuOOH phase by a pre-treatment using highly oxidative solutions. As revealed by SEM, XPS, and electrochemical analysis, such a strategy maintained the 3D structure, while inducing more active sites before the in situ generation of oxyhydroxide sites during the electrochemical reaction. The optimized NiCuOOH-1 sample exhibited the current density of 6.06 mA cm-2 at 0.5 V, which is 1.67 times higher than that of NiCu(OH)2 (3.63 mA cm-2). Moreover, the sample with a higher crystalline degree of the NiCuOOH phase exhibited lower performance, demonstrating the importance of a moderate treatment condition. In addition, the NiCuOOH-1 sample presented low selectivity (<20%) towards NO2- and stable activity during the long-term operation. The findings of this study would provide valuable insights into the development of transition metal electrocatalysts for ammonia oxidation.

Synergistic Inhibiting Effect of Phytochemicals in Rheum palmatum on Tyrosinase Based on Metabolomics and Isobologram Analyses.

Tyrosinase (TYR) plays a key role in the enzymatic reaction that is responsible for a range of unwanted discoloration effects, such as food browning and skin hyperpigmentation. TYR inhibitors could, therefore, be candidates for skin care products that aim to repair pigmentation problems. In this study, we used a metabolomics approach combined with the isobologram analysis to identify anti-TYR compounds within natural resources, and evaluate their possible synergism with each other. Rheum palmatum was determined to be a model plant for observing the effect, of which seven extracts with diverse phytochemicals were prepared by way of pressurized solvent extraction. Each Rheum palmatum extract (RPE) was profiled using nuclear magnetic resonance spectroscopy and its activity of tyrosinase inhibition was evaluated. According to the orthogonal partial least square analysis used to correlate phytochemicals in RPE with the corresponding activity, the goodness of fit of the model (R2 = 0.838) and its predictive ability (Q2 = 0.711) were high. Gallic acid and catechin were identified as the active compounds most relevant to the anti-TYR effect of RPE. Subsequently, the activity of gallic acid and catechin were evaluated individually, and when combined in various ratios by using isobologram analysis. The results showed that gallic acid and catechin in the molar ratios of 9:5 and 9:1 exhibited a synergistic inhibition on TYR, with a combination index lower than 0.77, suggesting that certain combinations of these compounds may prove effective for use in cosmetic, pharmaceutical, and food industries.

Increased expression of Clec9A on cDC1s associated with cytotoxic CD8+ T cell response in COPD.

Although C-type lectin domain family 9A (Clec9A) on conventional type 1 dendritic cells (cDC1s) plays a critical role in cytotoxic CD8+ T cell response in cancers and viral infections, its role in chronic obstructive pulmonary disease (COPD) is unknown. We measured the expression of Clec9A in sera, bronchoalveolar lavage fluid (BALF), and peripheral blood mononuclear cells (PBMCs) from controls and COPD patients. The percentages of Clec9A+ DC and cytotoxic CD8+ T cell in the BALF were determined by flow cytometry between patients with COPD and non-obstructive chronic bronchitis (NOCB). Compared with healthy individuals, the serum levels of Clec9A were increased at different stages of COPD patients, and the mRNA and protein levels of Clec9A were both increased in COPD patients at GOLD stages III-IV. The percentage of Clec9A+ DCs was also increased in the BALF of COPD patients compared with NOCB patients. Moreover, enhanced Clec9A+ DCs recruitment was positively correlated with cytotoxic CD8+ T cell response in the BALF of COPD patients. This study suggests that Clec9A+ DCs participate in the CD8+ T cell-mediated chronic airway inflammation in COPD.

Opportunities and hurdles to European market access for multi-herbal traditional Chinese medicine products: An analysis of EU regulations for combination herbal medicinal products.

TCM herbal remedies are popular among European patients. However, a very limited number of TCM products have been approved as herbal medicinal products (HMPs) in Europe. Multi-herbal TCM products, the most prevalent form of medication in TCM practice, are even rare. This indicates multi-herbal TCM products are facing considerable obstacles in the access to EU market. To further identify such obstacles, we make a systematic analysis of current advances in both EU herbal monographs and combination HMPs granted in member states and present main features of the regulation as well as challenges for multi-herbal TCM products. The results show the EU is open to combination HMPs based on TCM or other non-European traditions. The regulation allows appropriate flexibility in the range of drug extraction rations, variation in concentrations of extraction solvent and number of herbal drugs presented in the product, if plausible pharmacological effects could be justified. Meanwhile, to guarantee the safety and efficacy based on medicinal usage, especially to justify the rationale or plausibility of the combination, is the key element for well-established use or traditional use combination HMPs. Additionally, EU herbal monographs also have great value in their marketing procedure. Nonetheless, there are many challenges in the European market access of multi-herbal TCM products which lies in quality control, safety and efficacy evaluation and others e.g., practical standard for full marketing authorization. Enforced scientific research and communication among research institutions, industries and authorities are necessary to further facilitate the access of multi-herbal TCM products to EU market. The results of this article may provide guidance for HMPs based on TCM or other non-European traditions with intention to entering EU market.

A microRNA Signature Identifies Patients at Risk of Barrett Esophagus Progression to Dysplasia and Cancer.

BACKGROUND: Progression of Barrett esophagus (BE) to esophageal adenocarcinoma occurs among a minority of BE patients. To date, BE behavior cannot be predicted on the basis of histologic features. AIMS: We compared BE samples that did not develop dysplasia or carcinoma upon follow-up of ≥ 7 years (BE nonprogressed [BEN]) with BE samples that developed carcinoma upon follow-up of 3 to 4 years (BE progressed [BEP]). METHODS: The NanoString nCounter miRNA assay was used to profile 24 biopsy samples of BE, including 13 BENs and 11 BEPs. Fifteen samples were randomly selected for miRNA prediction model training; nine were randomly selected for miRNA validation. RESULTS: Unpaired t tests with Welch's correction were performed on 800 measured miRNAs to identify the most differentially expressed miRNAs for cases of BEN and BEP. The top 12 miRNAs (P < .003) were selected for principal component analyses: miR-1278, miR-1301, miR-1304-5p, miR-517b-3p, miR-584-5p, miR-599, miR-103a-3p, miR-1197, miR-1256, miR-509-3-5p, miR-544b, miR-802. The 12-miRNA signature was first self-validated on the training dataset, resulting in 7 out of the 7 BEP samples being classified as BEP (100% sensitivity) and 7 out of the 8 BEN samples being classified as BEN (87.5% specificity). Upon validation, 4 out of the 4 BEP samples were classified as BEP (100% sensitivity) and 4 out of the 5 BEN samples were classified as BEN (80% specificity). Twenty-four samples were evaluated, and 22 cases were correctly classified. Overall accuracy was 91.67%. CONCLUSION: Using miRNA profiling, we have identified a 12-miRNA signature able to reliably differentiate cases of BEN from BEP.

Octahedral spinel electrocatalysts for alkaline fuel cells.

Designing high-performance nonprecious electrocatalysts to replace Pt for the oxygen reduction reaction (ORR) has been a key challenge for advancing fuel cell technologies. Here, we report a systematic study of 15 different AB2O4/C spinel nanoparticles with well-controlled octahedral morphology. The 3 most active ORR electrocatalysts were MnCo2O4/C, CoMn2O4/C, and CoFe2O4/C. CoMn2O4/C exhibited a half-wave potential of 0.89 V in 1 M KOH, equal to the benchmark activity of Pt/C, which was ascribed to charge transfer between Co and Mn, as evidenced by X-ray absorption spectroscopy. Scanning transmission electron microscopy (STEM) provided atomic-scale, spatially resolved images, and high-energy-resolution electron-loss near-edge structure (ELNES) enabled fingerprinting the local chemical environment around the active sites. The most active MnCo2O4/C was shown to have a unique Co-Mn core-shell structure. ELNES spectra indicate that the Co in the core is predominantly Co2.7+ while in the shell, it is mainly Co2+ Broader Mn ELNES spectra indicate less-ordered nearest oxygen neighbors. Co in the shell occupies mainly tetrahedral sites, which are likely candidates as the active sites for the ORR. Such microscopic-level investigation probes the heterogeneous electronic structure at the single-nanoparticle level, and may provide a more rational basis for the design of electrocatalysts for alkaline fuel cells.

Revealing the atomic ordering of binary intermetallics using in situ heating techniques at multilength scales.

Ordered intermetallic nanoparticles are promising electrocatalysts with enhanced activity and durability for the oxygen-reduction reaction (ORR) in proton-exchange membrane fuel cells (PEMFCs). The ordered phase is generally identified based on the existence of superlattice ordering peaks in powder X-ray diffraction (PXRD). However, after employing a widely used postsynthesis annealing treatment, we have found that claims of "ordered" catalysts were possibly/likely mixed phases of ordered intermetallics and disordered solid solutions. Here, we employed in situ heating, synchrotron-based, X-ray diffraction to quantitatively investigate the impact of a variety of annealing conditions on the degree of ordering of large ensembles of Pt3Co nanoparticles. Monte Carlo simulations suggest that Pt3Co nanoparticles have a lower order-disorder phase transition (ODPT) temperature relative to the bulk counterpart. Furthermore, we employed microscopic-level in situ heating electron microscopy to directly visualize the morphological changes and the formation of both fully and partially ordered nanoparticles at the atomic scale. In general, a higher degree of ordering leads to more active and durable electrocatalysts. The annealed Pt3Co/C with an optimal degree of ordering exhibited significantly enhanced durability, relative to the disordered counterpart, in practical membrane electrode assembly (MEA) measurements. The results highlight the importance of understanding the annealing process to maximize the degree of ordering in intermetallics to optimize electrocatalytic activity.

International policies and challenges on the legalization of traditional medicine/herbal medicines in the fight against COVID-19.

The coronavirus disease 2019 (COVID-19) has now rapidly spread around the world, causing an outbreak of acute infectious pneumonia. To develop effective and safe therapies for the prevention and treatment of COVID-19 has become the major global public health concern. Traditional medicine (TM)/herbal medicines (HMs) have been used to treat multiple epidemics in human history, which brings hope for the fight against COVID-19 in some areas. For example, in China, India, and South Korea with traditional medication history and theory, the governments issued a series of guidelines to support TM/HMs in the medication of COVID-19. In contrast, other countries e.g. North American and European governments are typically silent on these practices, unless to warn of possible harm and overselling. Such difference is due to the discrepancy in culture, history and philosophical views of health care and medication, as well as unharmonized policies and standards in the regulation and legalization of TM/HMs among different areas. Herein, we reviewed the responses and scientific researches from seven selected countries on the policies and legalization of TM/HMs to treat COVID-19, and also analyzed the major challenges and concerns to utilize the traditional knowledge and resource.

Tumor size and focality in breast carcinoma: Analysis of concordance between radiological imaging modalities and pathological examination at a cancer center.

CONTEXT: Accurate assessment of clinical and pathological tumor stage is crucial for patient treatment and prognosis. OBJECTIVE: The aim of this study was to assess the concordance between the tumor size and focality between radiological studies and pathology and to evaluate the impact of discrepancies on staging. DESIGN: Patients who underwent surgery for invasive breast carcinoma from January 1, 2014, to December 31, 2015, were identified. RESULTS: Three imaging modalities (mammogram, ultrasound and MRI) were compared with gross examination and final pathology. 1152 preoperative radiological studies were evaluated for focality and 1019 were evaluated for tumor size. For all 3 radiographic modalities, there was a statistically significant difference between the mean tumor size on radiology and the final pathology report (mammogram, P < .001; ultrasound, P = .004; MRI, P < .001). In 29% of radiology studies, there was a discrepancy in stage. The error rate for determining focality was 28% for mammograms, 27% for ultrasounds, and 29% for MRIs. Tumor size from gross examination correlated with microscopic tumor size in 57% of cases, but gross examination had 88% concordance with the final pathology report in determining focality. CONCLUSION: Our study revealed statistically significant differences in mean tumor size reported across all 3 imaging modalities when compared to the final pathology report. MRI had the highest error rate, with a tendency to overestimate tumor size and number of foci. Among all diagnoses, cases of invasive carcinoma with an extensive intraductal component were most prone to discrepancies with imaging.

[Research progress on hepatotoxicity of traditional Chinese medicine based on metabonomics].

With the continuous development of Chinese medicine, traditional Chinese medicine(TCM) has been widely used in the treatment of diseases and health care. At the same time, the toxic and side effects of TCM have been gradually concerned. The liver, as an important place for drug metabolism, is a major target organ for drug toxicity. Clinical reports on liver injury caused by TCM are common, and the problem of liver toxicity of TCM has become an important reason to limit the internationalization of TCM. Metabono-mics is a newly booming subject to study the metabolic pathway of biological system. It shows integrity and systematicness in the study of hepatotoxicity of TCM, which provides a new technical method for finding the early biomarkers of liver injury of TCM and exploring the mechanism of hepatotoxicity of TCM. In this paper, the methods of metabonomics in the study of hepatotoxicity of TCM, as well as the research progress of hepatotoxicity monomer, extract and attenuation of hepatotoxic TCM based on metabonomics were reviewed in order to provide reference for the further study of hepatotoxicity of TCM.

Cobalt-Based Nitride-Core Oxide-Shell Oxygen Reduction Electrocatalysts.

Developing high-performance, low-cost, and conductive nonprecious electrocatalysts for the oxygen reduction reaction (ORR) has been a key challenge for advancing fuel cell technologies. Here, we report on a novel family of cobalt nitrides (CoxN/C, x = 2, 3, 4) as ORR electrocatalysts in alkaline fuel cells. Co4N/C exhibited the highest ORR activity among the three types of cobalt nitrides studied, with a half-wave potential (E1/2) of 0.875 V vs RHE in 1 M KOH, rivaling that of commercial Pt/C (0.89 V). Moreover, Co4N/C showed an 8-fold improvement in mass activity at 0.85 V, when compared to cobalt oxide, Co3O4/C, and a negligible degradation (ΔE1/2 = 14 mV) after 10 000 potential cycles. The superior performance was ascribed to the formation of a conductive nitride core surrounded by a naturally formed thin oxide shell (about 2 nm). The conductive nitride core effectively mitigated the low conductivity of the metal oxide, and the thin oxide shell on the surface provided the active sites for the ORR. Strategies developed herein represent a promising approach for the design of other novel metal nitrides as electrocatalysts for fuel cells.

A Strategy for Increasing the Efficiency of the Oxygen Reduction Reaction in Mn-Doped Cobalt Ferrites.

Alkaline fuel cells have drawn increasing attention as next-generation energy-conversion devices for electrical vehicles, since high pH enables the use of non-precious-metal catalysts. Herein, we report on a family of rationally designed Mn-doped cobalt ferrite (MCF) spinel nanocrystals, with an optimal composition Mn0.8(CoFe2)0.73O4 (MCF-0.8), that are effective electrocatalysts for the oxygen reduction reaction. MCF-0.8 exhibits a half-wave potential ( E1/2) of 0.89 V vs RHE in 1 M NaOH, only 0.02 V less than that of commercial Pt/C under identical testing conditions and, to the best of our knowledge, one of the highest recorded values in the literature. Moreover, MCF-0.8 exhibits remarkable durability (Δ E1/2 = 0.014 V) after 10 000 electrochemical cycles. In situ X-ray absorption spectroscopy (XAS) reveals that the superior performance of the trimetallic MCF-0.8 originates from the synergistic catalytic effect of Mn and Co, while Fe helps preserve the spinel structure during cycling. We employed in situ XAS to track the evolution of the oxidation states and the metal-oxygen distances not only under constant applied potentials (steady state) but also during dynamic cyclic voltammetry (CV) (nonsteady state). The periodic conversion between Mn(III, IV)/Co(III) and Mn(II, III)/Co(II) as well as the essentially constant oxidation state of Fe during the CV suggests collaboration efforts among Mn, Co, and Fe. Mn and Co serve as the synergistic coactive sites to catalyze the oxygen reduction, apparently resulting in the observed high activity, while Fe works to maintain the integrity of the spinel structure, likely contributing to the remarkable durability of the catalyst. These findings provide a mechanistic understanding of the electrocatalytic processes of trimetallic oxides under real-time fuel cell operating conditions. This approach provides a new strategy to design high-performance non-precious-metal electrocatalysts for alkaline fuel cells.

Metal-Organic-Framework-Derived Co-Fe Bimetallic Oxygen Reduction Electrocatalysts for Alkaline Fuel Cells.

The oxygen reduction reaction (ORR) is considered the cornerstone for regenerative energy conversion devices involving fuel cells and electrolyzers. The development of non-precious-metal electrocatalysts is of paramount importance for their large-scale commercialization. Here, Co-Fe binary alloy embedded bimetallic organic frameworks (BMOF)s based on carbon nanocomposites have been designed with a compositionally optimized template, by a facile host-guest strategy, for ORR in alkaline media. The electrocatalyst exhibits promising electrocatalytic activity for ORR with a half-wave potential of 0.89 V in 0.1 M NaOH, comparable to state-of-the-art Pt/C electrocatalysts. More importantly, it exhibits robust durability after 30 000 potential cycles. Scanning transmission electron microscopy (STEM) and quantitative energy-dispersive X-ray (EDX) spectroscopy suggest that the Co-Fe alloy nanoparticles have a homogeneous elemental distribution of Co and Fe at the atomic-scale optimized BMOF and Co/Fe ratio of 9:1. The long-term durability is attributed to its ability to maintain its structural and compositional integrity after the cycling process, as evidenced by STEM-EDX analysis. This work provides valuable insights into the design and fabrication of novel platinum-group-metals-free highly active ORR electrocatalysts in alkaline media.

In Situ X-ray Absorption Spectroscopy of a Synergistic Co-Mn Oxide Catalyst for the Oxygen Reduction Reaction.

Identifying the catalytically active site(s) in the oxygen reduction reaction (ORR), under real-time electrochemical conditions, is critical to the development of fuel cells and other technologies. We have employed in situ synchrotron-based X-ray absorption spectroscopy (XAS) to investigate the synergistic interaction of a Co-Mn oxide catalyst which exhibits impressive ORR activity in alkaline fuel cells. X-ray absorption near edge structure (XANES) was used to track the dynamic structural changes of Co and Mn under both steady state (constant applied potential) and nonsteady state (potentiodynamic cyclic voltammetry, CV). Under steady state conditions, both Mn and Co valences decreased at lower potentials, indicating the conversion from Mn(III,IV) and Co(III) to Mn(II,III) and Co(II), respectively. Rapid X-ray data acquisition, combined with a slow sweep rate in CV, enabled a 3 mV resolution in the applied potential, approaching a nonsteady (potentiodynamic) state. Changes in the Co and Mn valence states were simultaneous and exhibited periodic patterns that tracked the cyclic potential sweeps. To the best of our knowledge, this represents the first study, using in situ XAS, to resolve the synergistic catalytic mechanism of a bimetallic oxide. Strategies developed/described herein can provide a promising approach to unveil the reaction mechanism for other multimetallic electrocatalysts.

Cigarette Smoke Extract Promotes TIM4 Expression in Murine Dendritic Cells Leading to Th2 Polarization through ERK-Dependent Pathways.

Smoking is considered to be the main source of indoor pollution, and it has been identified as an important environmental factor contributing to asthma onset. We know that T helper 2 (Th2) response plays a crucial role in the process of asthma disease. We have investigated the reaction of cigarette smoke extract (CSE) on Th polarization which is controlled by dendritic cells (DCs). Stimulated by CSE, immature DCs from murine bone marrow showed upregulated levels of TIM4. Cocultured with CD4+ T cells, stimulated DCs increased the ratio of IL-4+ versus IFN-γ+ of CD4+ T cells. This suggests a differentiation towards Th2 response. Moreover, antibodies against TIM4 reversed the upexpression of the IL-4+/IFN-γ+ ratio provoked by CSE, indicating that the Th2 polarization which was induced by CSE is via TIM4 mechanisms. CSE could activate mitogen-activated protein kinase pathways like ERK and p38. Upregulation of TIM4 expression by CSE stimulation was found to be inhibited by an ERK inhibitor but not p38 and JNK. In conclusion, DC-induced Th2 polarization is a hallmark of CSE allergy, and this aspect can be explained by CSE-induced TIM4 expression.

Twenty-year surgical trends in a gynecologic oncology fellowship training program: Implications for practice.

OBJECTIVE: To assess whether there were any significant changes in surgical training volume over the past 20 years that might have ramifications toward preparedness for practice. METHODS: We used deidentified annual summaries of fellow case numbers for the academic years 1999 through 2018. Unpaired t-tests with Welch's correction were performed on all surgical categories for 10-year and 5-year periods. RESULTS: The total number of hysterectomies performed each year did not change significantly. The percent of hysterectomies performed by minimally invasive surgery increased significantly starting in 2008. There was a significant decline in the number of radical hysterectomies conducted starting after 2004, which then remained stable. There was also a significant decline in the number of bowel resections/anastomoses performed by fellows on the gynecologic oncology services that occurred and stabilized during the same time frame. There were other significant trends associated with the introduction of minimally invasive techniques. CONCLUSION: The results of this study suggest the need to reevaluate fellowship training and/or the scope of surgical practice in gynecologic oncology.

Quality Evaluation of Gastrodia Elata Tubers Based on HPLC Fingerprint Analyses and Quantitative Analysis of Multi-Components by Single Marker.

Gastrodia elata (G. elata) tuber is a valuable herbal medicine used to treat many diseases. The procedure of establishing a reasonable and feasible quality assessment method for G. elata tuber is important to ensure its clinical safety and efficacy. In this research, an effective and comprehensive evaluation method for assessing the quality of G. elata has been developed, based on the analysis of high performance liquid chromatography (HPLC) fingerprint, combined with the quantitative analysis of multi-components by single marker (QAMS) method. The contents of the seven components, including gastrodin, p-hydroxybenzyl alcohol, p-hydroxy benzaldehyde, parishin A, parishin B, parishin C, and parishin E were determined, simultaneously, using gastrodin as the reference standard. The results demonstrated that there was no significant difference between the QAMS method and the traditional external standard method (ESM) (p > 0.05, RSD < 4.79%), suggesting that QAMS was a reliable and convenient method for the content determination of multiple components, especially when there is a shortage of reference substances. In conclusion, this strategy could be beneficial for simplifying the processes in the quality control of G. elata tuber and giving references to promote the quality standards of herbal medicines.

Pt-Decorated Composition-Tunable Pd-Fe@Pd/C Core-Shell Nanoparticles with Enhanced Electrocatalytic Activity toward the Oxygen Reduction Reaction.

Design of electrocatalysts with both a high-Pt-utilization efficiency and enhanced electrochemical activity is still the key challenge in the development of proton exchange membrane fuel cells. In the present work, Pd-Fe/C bimetallic nanoparticles (NPs) with an optimal Fe composition and decorated with Pt are introduced as promising catalysts toward the oxygen reduction reaction. These bimetallic nanoparticles have a Pd-Fe@Pd core-shell structure with a surface Pt decoration as established through the use of electron energy loss spectroscopy (EELS) and energy-dispersive X-ray (EDX) spectroscopy. These catalysts exhibit excellent electrocatalytic activity ( E1/2 = 0.866 V vs RHE), increasing the mass activity by more than 70% over that of Pt/C in terms of the total mass of Pt and Pd and by 14 times if only Pt is considered. Simple geometrical calculations, based on spherical core-shell models, indicate that Pd-Fe@Pt has a surface Pt decoration rather than a complete Pt monolayer. Such calculations applied to other examples in the literature point out the need for careful and rigorous arguments about claimed "Pt monolayer/multilayers". Such calculations must be based on not only elemental mapping data but also on the Pt/Pd and other metal atomic ratios in the precursors. Our analysis predicts a minimal Pt/Pd atomic ratio in order to achieve a complete Pt monolayer on the surface of the core materials.