Effect of the grain arrangements on the thermal stability of polycrystalline nickel-rich lithium-based battery cathodes.

One of the most challenging aspects of developing high-energy lithium-based batteries is the structural and (electro)chemical stability of Ni-rich active cathode materials at thermally-abused and prolonged cell cycling conditions. Here, we report in situ physicochemical characterizations to improve the fundamental understanding of the degradation mechanism of charged polycrystalline Ni-rich cathodes at elevated temperatures (e.g., ≥ 40 °C). Using multiple microscopy, scattering, thermal, and electrochemical probes, we decouple the major contributors for the thermal instability from intertwined factors. Our research work demonstrates that the grain microstructures play an essential role in the thermal stability of polycrystalline lithium-based positive battery electrodes. We also show that the oxygen release, a crucial process during battery thermal runaway, can be regulated by engineering grain arrangements. Furthermore, the grain arrangements can also modulate the macroscopic crystallographic transformation pattern and oxygen diffusion length in layered oxide cathode materials.

Revealing the Dynamics and Roles of Iron Incorporation in Nickel Hydroxide Water Oxidation Catalysts.

The surface of an electrocatalyst undergoes dynamic chemical and structural transformations under electrochemical operating conditions. There is a dynamic exchange of metal cations between the electrocatalyst and electrolyte. Understanding how iron in the electrolyte gets incorporated in the nickel hydroxide electrocatalyst is critical for pinpointing the roles of Fe during water oxidation. Here, we report that iron incorporation and oxygen evolution reaction (OER) are highly coupled, especially at high working potentials. The iron incorporation rate is much higher at OER potentials than that at the OER dormant state (low potentials). At OER potentials, iron incorporation favors electrochemically more reactive edge sites, as visualized by synchrotron X-ray fluorescence microscopy. Using X-ray absorption spectroscopy and density functional theory calculations, we show that Fe incorporation can suppress the oxidation of Ni and enhance the Ni reducibility, leading to improved OER catalytic activity. Our findings provide a holistic approach to understanding and tailoring Fe incorporation dynamics across the electrocatalyst-electrolyte interface, thus controlling catalytic processes.

Bioorthogonal catalytic patch.

Bioorthogonal catalysis mediated by transition metals has inspired a new subfield of artificial chemistry complementary to enzymatic reactions, enabling the selective labelling of biomolecules or in situ synthesis of bioactive agents via non-natural processes. However, the effective deployment of bioorthogonal catalysis in vivo remains challenging, mired by the safety concerns of metal toxicity or complicated procedures to administer catalysts. Here, we describe a bioorthogonal catalytic device comprising a microneedle array patch integrated with Pd nanoparticles deposited on TiO2 nanosheets. This device is robust and removable, and can mediate the local conversion of caged substrates into their active states in high-level living systems. In particular, we show that such a patch can promote the activation of a prodrug at subcutaneous tumour sites, restoring its parent drug's therapeutic anticancer properties. This in situ applied device potentiates local treatment efficacy and eliminates off-target prodrug activation and dose-dependent side effects in healthy organs or distant tissues.

Solid-State Synthesis of Highly Dispersed Nitrogen-Coordinated Single Iron Atom Electrocatalysts for Proton Exchange Membrane Fuel Cells.

Fe-N-C with atomically dispersed Fe single atoms is the most promising candidate to replace platinum for the oxygen reduction reaction (ORR) in fuel cells. However, the conventional synthesis procedures require quantities solvents and metal precursors, sluggish adsorption process, and tedious washing, resulting in limited metal doping and uneconomical for large-scale production. For the first time, Fe2O3 is adopted as the Fe precursor to derive abundant single Fe atoms dispersed on carbon surfaces. The Fe-N-C catalyst synthesized by this simple method shows an excellent ORR activity with half-wave potentials of 0.82 and 0.90 V in acidic and alkaline solutions, respectively. A single fuel cell with an optimized Fe-N-C cathode shows a high peak power density of 0.84 W cm-2. The solid-state transformation synthesis method developed in this study may shed light on mass production of single-atom-based catalysts.

Comparison of the clinical outcomes of percutaneous vertebroplasty vs. kyphoplasty for the treatment of osteoporotic Kümmell's disease:a prospective cohort study.

BACKGROUND: Percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) are widely used in the treatment of Kümmell's disease. The purpose of this article is to investigate the clinical efficacy of PVP and PKP for Kümmell's disease. METHODS: The clinical data that 56 cases of Kümmell's disease treated with either PVP (28 cases) or PKP (28 cases) from December 2015 to December 2017 were prospectively analyzed. Gender, age, course of disease, injury segment, bone mineral density (BMD), visual analogue scale (VAS), Oswestry disability index (ODI), imaging measurement indexes before surgery between the two groups showed no significant difference (all P > 0.05). The bone cement leakage rate, bone cement injection amount, operation time, VAS, ODI, the rate of vertebral compression, correction rate of kyphosis and refracture rate of adjacent vertebra in 2 years were compared between the two groups to calculate clinical efficacy. RESULTS: The two groups were followed up for 24-48 months. There was no significant difference in the follow-up time, amount of bone cement injected, incidence of bone cement leakage and refracture rate of adjacent vertebrae between the two groups (all P > 0.05). The operation time, intraoperative blood loss and fluoroscopy times of the PVP group were significantly lower than those of the PKP group (all P = 0.000). VAS score and ODI of the two groups were significantly lower at 1 day, 1 year and 2 years after surgery than before surgery (all P < 0.05), but there was not statistically significant difference between the two groups at each time point after surgery (all P > 0.05). The rate of vertebral compression and kyphosis correction in the two groups were significantly corrected (P < 0.05, respectively) and decreased significantly with time (all P < 0.05), But there was not significant difference between the two groups at any time point (all P > 0.05). CONCLUSION: Both PVP and PKP can achieve similar effects in the treatment of Kümmell's disease. Because the cost, operation time, blood loss, radiation exposure and surgical procedure of PVP are less than those of PKP, PVP has more clinical priority value.

Broadband Tunable Mid-infrared Plasmon Resonances in Cadmium Oxide Nanocrystals Induced by Size-Dependent Nonstoichiometry.

A central theme of nanocrystal (NC) research involves synthesis of dimension-controlled NCs and studyof size-dependent scaling laws governing their optical, electrical, magnetic, and thermodynamic properties. Here, we describe the synthesis of monodisperse CdO NCs that exhibit high quality-factor (up to 5.5) mid-infrared (MIR) localized surface plasmon resonances (LSPR) and elucidate the inverse scaling relationship between carrier concentration and NC size. The LSPR wavelength is readily tunable between 2.4 and ∼6.0 µm by controlling the size of CdO NCs. Structural and spectroscopic characterization provide strong evidence that free electrons primarily originate from self-doping due to NC surface-induced nonstoichiometry. The ability to probe and to control NC stoichiometry and intrinsic defects will pave the way toward predictive synthesis of doped NCs with desirable LSPR characteristics.

Targeted Surface Doping with Reversible Local Environment Improves Oxygen Stability at the Electrochemical Interfaces of Nickel-Rich Cathode Materials.

Elemental doping represents a prominent strategy to improve interfacial chemistry in battery materials. Manipulating the dopant spatial distribution and understanding the dynamic evolution of the dopants at the atomic scale can inform better design of the doping chemistry for batteries. In this work, we create a targeted hierarchical distribution of Ti4+, a popular doping element for oxide cathode materials, in LiNi0.8Mn0.1Co0.1O2 primary particles. We apply multiscale synchrotron/electron spectroscopy and imaging techniques as well as theoretical calculations to investigate the dynamic evolution of the doping chemical environment. The Ti4+ dopant is fully incorporated into the TMO6 octahedral coordination and is targeted to be enriched at the surface. Ti4+ in the TMO6 octahedral coordination increases the TM-O bond length and reduces the covalency between (Ni, Mn, Co) and O. The excellent reversibility of Ti4+ chemical environment gives rise to superior oxygen reversibility at the cathode-electrolyte interphase and in the bulk particles, leading to improved stability in capacity, energy, and voltage. Our work directly probes the chemical environment of doping elements and helps rationalize the doping strategy for high-voltage layered cathodes.

Predicting hepatocellular carcinoma development for cirrhosis patients via methylation detection of heparocarcinogenesis-related genes.

Background: Most hepatocellular carcinoma (HCC) patients have undergone a progression from chronic hepatitis, then liver cirrhosis (LC), and finally to carcinoma. The objective of this study was to elucidate risk factors to predict HCC development for cirrhosis patients. Methods: Multiple methylated specific PCR (MSP) was applied to determine methylation status of heparocarcinogenesis-related genes in 396 tissue and plasma specimens and multivariate cox model was used to analyze the relationship between risk variables and HCC development among cirrhosis patients, followed up in a median period of 30 months. Results: Among 105 LC cases, HCC incidence rate at 30 months was 30.48% (32/105), which were statistically associated with patients' age and aberrant methylation of p16, SFRP, and LINE1 (p<0.05). Receiver operating characteristic (ROC) curve showed the overall predictive accuracy reached the highest (90.7%) if the four risk variables were concurrent to predict HCC development. Moreover, along with the growth of age from 0-40, 40-55, to 55-70 years or the increased number of aberrantly-methylated gene from 0-1 to 2-3, the HCC incidence rate of cirrhosis patients rised from 10.00%, 12.28% to 82.14% and 17.44% to 89.47%, separately. Thus, based on combined analysis with diverse age and number of aberrantly-methylated gene, 105 cases were divided into five groups and computed their respective HCC incidecne rate to categorize them into different risk groups. Of note, A significant lifting of HCC incidence rate in the high-risk group (40-55 years coupled with 2-3 aberrantly-methylated genes, 55-70 years coupled with 0-1 aberrantly-methylated gene, 55-70 years coupled with 2-3 aberrantly-methylated genes; n=33) was observed compared with the low-risk group (0-40 years coupled with 0-1 aberrantly-methylated gene, 40-55 years coupled with 0-1 aberrantly-methylated gene; (n=72) (p<0.01). Conclusions: Ultimately, high-risk cirrhosis patients with 55-over years or 2-3 aberrantly-methylated genes should be paid more attention to be regularly screened with HCC development.

Application of multiplex methylated-specific PCR with capillary electrophoresis to explore prognostic value of TSGs hypermethylation for hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a malignant tumor that severely threatens human health. To date, early detection for HCC patients is particularly significant due to their poor survival rates even after liver resection. METHODS: Therefore, an efficient and sensitive detection method for monitoring liver cancer, multiplex methylation-specific PCR (MSP) coupled with capillary electrophoresis, is developed. RESULTS: Simulations demonstrated that the methylation status of RASSF1A, p16, SFRP1, and ELF could be detected even when DNA equaled or exceeded 12.5 ng simultaneously. Also, its accuracy for methylation detection outweighed polyacrylamide gel electrophoresis (87.5%) and agarose electrophoresis (84.3%), reaching 92.1%. Subsequently, we implemented multiplex MSP with capillary electrophoresis to investigate methylation status of the four tumor suppressor genes in tissue specimens and explore the prognostic value for HCC patients. As the data suggested, multivariate cox regression analysis revealed that the recurrence-free survival of 46 patients was greatly associated with portal vein tumor thrombus (PVTT) and p16 methylation and receiver operating characteristic (ROC) curves demonstrated that the predictive range of portal vein tumor thrombus (PVTT) combined with p16 hypermethylation was more sensitive than that of either PVTT or p16 hypermethylation alone with regard to disease recurrence in patients with HCC, which could be testified as a valuable biomarker in Clinical application. CONCLUSION: Multiplex MSP coupled with capillary electrophoresis has an excellent prospect of clinical application for monitoring early liver cancer and screening valuable biomarkers for prognosis of HCC patients.

Probing Framework-Restricted Metal Axial Ligation and Spin State Patterns in a Post-Synthetically Reduced Iron-Porphyrin-Based Metal-Organic Framework.

An iron-porphyrin-based metal organic framework PCN-222(Fe) is investigated upon postsynthetic reduction with piperidine. Fe K-edge X-ray absorption and Kß mainline emission spectroscopy measurements reveal the local coordination geometry, oxidation, and spin state changes experienced by the Fe sites upon reaction with this axially coordinating reducing agent. Analysis and fitting of these data confirm the binding pattern predicted by a space-filling model of the structurally constrained pore environments. These results are further supported by UV-vis diffuse reflectance, IR, and resonance Raman spectroscopy data.

Insight into the Capacity Fading Mechanism of Amorphous Se2S5 Confined in Micro/Mesoporous Carbon Matrix in Ether-Based Electrolytes.

In contrast to the stable cycle performance of space confined Se-based cathodes for lithium batteries in carbonate-based electrolytes, their common capacity fading in ether-based electrolytes has been paid less attention and not yet well-addressed so far. In this work, the lithiation/delithiation of amorphous Se2S5 confined in micro/mesoporous carbon (Se2S5/MPC) cathode was investigated by in situ X-ray near edge absorption spectroscopy (XANES) and theoretical calculations. The Se2S5/MPC composite was synthesized by a modified vaporization-condensation method to ensure a good encapsulation of Se2S5 into the pores of MPC host. In situ XANES results illustrated that the lithiation/delithiation reversibility of Se component was gradually decreased in ether-based electrolytes, leading to an aggravated formation of long-chain polyselenides during cycling and further capacity decay. Moreover, ab initio calculations revealed that the binding energy of polyselenides (Li2Sen) with carbon host is in an order of Li2Se6 > Li2Se4 > Li2Se. The insights into the failure mechanism of Se-based cathode gain in this work are expected to serve as a guide for future design on high performance Se-based cathodes.

[The Evaluation Value of Methylation Status of CpG Island of SFRP1 and LINE1 Gene Promoter Area in the Prognosis of Hepatocellular Carcinoma.]

OBJECTIVES: To investigate the relationship between aberrant promoter CpG islands methylation status of secreted frizzled related protein 1 (SFRP1) and long intersper sed nuclear element 1 (LINE1) gene and clinicopathologic parameters to determine their prognosis value for hepatocellular carcinoma (HCC). METHODS: 105 cases of HCC and 50 cases of normal people plasma were collected,and then the promoter hypermethylation status of SFRP1 and hypormethylation status of LINE1 were examined by methylation specific PCR (MSP); The relationship between SFRP1/LINE1 methylation status and patients' clinicopathologic factors was analyzed;The association between SFRP1/LINE1 methylation status and disease-free survival and overall survival was analyzed by Kaplan-Meier curves,the log-rank test,and multivariate Cox regression. RESULTS: SFRP1 gene promoter CpG islands hypermethylation and LINE1 gene promoter CpG islands hypomethylation were found in 59.05% (62/105) and 66.67% (70/105) of 105 cancerous plasma cases,repectively,SFRP1 hypermethylation status and LINE1 hypomethylation status in plasma of HCC account for 43.81%(62/105) and no positive methylation cases were detected in normal cases;The hypermethylation status of SFRP1 and hypomethylation status of LINE1 gene were related with HBsAg and α-fetoprotein (AFP) level;There was statistically significant difference between CpG islands hypermethylation of two genes and disease-free survival rate and overall survival rate;The group patients with SFRP1 hypermethylation positive and LINE1 hypomethylation positive demonstrated the worst prognosis while the group with SFRP1 hypermethylation negative and LINE1 hypomethylation negative had the best prognosis. CONCLUSIONS: The promoter methylation of SFRP1 and LINE1 is correlated with the occurrence and development of HCC.SFRP1 and LINE1 might be potential and reliable biomarkers for predicting prognosis in HCC patients.

Synthesis and antitumor activities of novel dibenzo[b,d]furan-imidazole hybrid compounds.

A series of novel hybrid compounds between dibenzo[b,d]furan and imidazole has been prepared and evaluated in vitro against a panel of human tumor cell lines. The results suggest that the existence of benzimidazole ring, and the substitution of the imidazolyl-3-position with a naphthylacyl or 4-methoxyphenacyl group, were vital for modulating cytotoxic activity. In particular, hybrid compound 60 was found to be the most potent derivatives against all of human tumor cell lines investigated, while compound 49 was found to be more selective against breast carcinoma (MCF-7) and myeloid liver carcinoma (SMMC-7721). Compound 60 can induce the G1 phase cell cycle arrest and apoptosis in SMMC-7721 cells.

Design, synthesis and biological evaluation of novel hybrid compounds of imidazole scaffold-based 2-benzylbenzofuran as potent anticancer agents.

A series of novel hybrid compounds between 2-benzylbenzofuran and imidazole has been prepared and evaluated in vitro against a panel of human tumor cell lines. The results suggest that the existence of benzimidazole ring and substitution of the imidazolyl-3-position with a naphthylacyl or 4-methoxyphenacyl group were vital for modulating cytotoxic activity. In particular, hybrid compounds 46 and 47 were found to be the most potent derivatives against 5 strains human tumor cell lines and more active than cisplatin (DDP), and exhibited cytotoxic activities selectively against breast carcinoma (MCF-7) and myeloid liver carcinoma (SMMC-7721), respectively.

[Determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection].

OBJECTIVE: To develop a method for the simultaneous determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection. METHODS: Organophosphorus pesticides in food were extracted ultrasonically with water. Then the extract was cleaned-up with SPE disk and eluted with ethyl acetate. Finally the eluent was condensed to 1mL under N2 at 55 degrees C. Gas chromatography was applied for quantitative detection of the organophosphorus pesticides in the sample. RESULTS: The linear range of the method for all the pesticides were in the range of 0.01-0.5 mg/kg with correlation coefficients of 0.992-1.000. The detection limits of the method were in the range of 0.0005-0.01 mg/kg. The recoveries for most pesticides were 60%-120% with relative standard deviations of less than 15%. CONCLUSION: The method is simple, sensitive, environmentally friendly and suitable for the determination of organophosphorous pesticides in food.

[Rapid determination of ethanol in blood by capillary-gas chromatography].

OBJECTIVE: To develop a method for the rapid determination of ethanol in blood with capillary-GC. METHODS: 0.50 mL of whole blood sample was taken and added with 1.00 mL of dimethyl sulfoxide (DMSO), and 2 g of anhydrous sodium sulfate. The supernatant of the sample solution was directly injected into GC for analysis. RESULTS: Ethanol was separated from other substances in the sample. The liner range of ethanol detected by the capillary-GC was 0.0-300.0 mg/100 mL, and the detection limit was 0.2 mg/100 mL. The RSD for standard solution determination was 1.36%. Satisfactory results were obtained for the determination of ethanol in whole blood samples, with recoveries ranging from 90.9% to 107.3% and a RSD of 1.98%. The combined uncertainty was 2.2%. CONCLUSION: This is a rapid, sensitive and simple method for determination of ethanol in large quantities of samples. The method has shortened the duration of analysis cycle in comparison with the traditional headspace-GC, with a reduction from 20-30 min to less than 10 min.

Interaction among proteins and peptide libraries in proteome analysis: pH involvement for a larger capture of species.

When capturing proteins via combinatorial peptide ligand libraries, a method well known for drastically reducing the concentration of high-abundance proteins and substantially magnifying the signal of low-abundance species, thus leading to the discovery of a large number of proteins previously undetected in proteomes, we had constantly noticed that there would be a loss of species initially present in the untreated sample, to the tune of 5%, up to 15% in some cases. Such losses are a nuisance and hamper to some extent the unique performance of the method. In order to verify if such losses could be reduced and also to understand some mechanisms of the capture process, we introduce here an important variant to the capture operation, up to the present carried out in physiological saline at pH 7.2. In this novel protocol, the binding step is conducted at three different pH values, namely the standard one at pH 7.2, plus two additional processes, at acidic (pH 4.0) and alkaline (pH 9.3) pH values. Indeed the capture process is more extensive, with a number of additional species captured at the two pH extremes in sera and other proteomes. Interestingly, at pH 4.0 newly detected proteins were mostly acidic, while at the alkaline pH additional protein species were more evenly distributed throughout the pI range towards the alkaline area. The role of pH in the complex mechanism of binding among the hexapeptide library and the various proteomes being analyzed is discussed and evaluated. Due to significant changes in protein patterns with pH, recommendations are thus made to increase the possibility to find additional gene products illustrated by two examples (snake venom and leaf protein extract). Keeping under control the environmental pH when facing reproducibility studies or for comparative proteomics profiling is also a general rule suggested by this study.

[Determination of methanol and fusel oils in alcohol beverages using headspace solid-phase microextraction and gas chromatography].

A method for the determination of methanol and fusel oils in alcohol beverages using headspace solid-phase microextraction and gas chromatography (HS-SPME-GC) is presented. The solid phase was a coated epoxy resin. The extraction and chromatography conditions were optimized. Limits of detection were 0.02 mg/L-0.04 mg/L and relative standard deviations were in the range of 1.4%-4.1%. The proposed method showed better sensitivity in comparing with direct headspace gas chromatography(HS-GC, the National Standard method). This method was applied to evaluate real samples. The spiked recoveries in beer, wine and functional alcohol samples ranged from 80.8% to 110.3% for methanol and fusel oils. The results by HS-SPME-GC and HS-GC for alcohol samples coincided very well. The proposed method is simple, fast and accurate with high reproducibility, high sensitivity and low cost. It extends the applications of SPME.