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The Rh(III)-catalyzed oxidative coupling of oxime ether (S1) and cyclopropanol (S2) with Cu(II) as the oxidant features the combination of C-H activation and strained ring opening. The sequential order of C-H activation versus ring opening was investigated with the aid of density functional theory calculations. Prior ring opening due to the release of ring strain is found to be favored over the prior C-H activation. For the prior ring-opening mechanisms, the outer-sphere concerted metalation-deprotonation (CMD) mechanism in C-H bond activation is energetically favored. The outer-sphere CMD mechanism proposed in this work favors solvent effects and affords the N→Rh binding that allows a directing role of the Schiff base group. In conclusion, the reaction was suggested to undergo prior ring opening followed by C-H activation via the outer-sphere CMD mechanism.

In this study, we report the complete mitochondrial genome of Harpalus sinicus (occasionally named as the Chinese ground beetle) which is the first mitochondrial genome for Harpalus. The mitogenome is 16,521 bp in length, comprising 37 genes, and a control region. The A + T content of the mitogenome is as high as 80.6%. A mitochondrial origins of light-strand replication (OL)-like region is found firstly in the insect mitogenome, which can form a stem-loop hairpin structure. Thirteen protein-coding genes (PCGs) share high homology, and all of them are under purifying selection. All tRNA genes (tRNAs) can be folded into the classic cloverleaf secondary structures except tRNA-Ser (GCU), which lacks a dihydrouridine (DHU) stem. The secondary structure of two ribosomal RNA genes (rRNAs) is predicted based on previous insect models. Twelve types of tandem repeats and two stem-loop structures are detected in the control region, and two stem-loop structures may be involved in the initiation of replication and transcription. Additionally, phylogenetic analyses based on mitogenomes suggest that Harpalus is an independent lineage in Carabidae, and is closely related to four genera (Abax, Amara, Stomis, and Pterostichus). In general, this study provides meaningful genetic information for Harpalus sinicus and new insights into the phylogenetic relationships within the Carabidae.

As one of the most prospective transitional metal oxide cathode materials for sodium-ion batteries (SIBs), P2-type Na2/3Ni1/3Mn2/3O2 layered oxide generally suffers from sluggish Na+ kinetics and complicated structural evolution. Here, a stable Co-free P2-Na2/3Li1/9Ni2/9Mn2/3O2 cathode material with multilayer oriented stacking nanoplates is reported, which exhibits high hydrostability realized by partial Li element substitution for Ni. A prominent rate capability (71.7% capacity retention at 5 C compared to 0.2 C), an excellent cycling stability (78.7% capacity retention at 2 C after 300 cycles) and a promoted performance even at a higher cutoff potential of 4.4 V were displayed owing to bifunctional strategy of chemical substitution coupled with structure modulation, and the as-synthesized material retains its original structure and electrochemical performance after being aged in water. Moreover, dominant Na+ capacitive storage mechanism, high thermostability and complete solid-solution reaction are explicitly elucidated through quantitative calculation of electrochemical kinetics and in-situ X-ray diffraction technique. These findings reveal the importance of rational chemical substitution and structure modulation strategy, and inspire novel design of high-performance cathode materials for rechargeable SIBs.

Preparing excellent hydroxide precursor is a significant step in the synthesis of high-energy–density Ni-Rich cathode materials. Efforts to address their limited cycle life have focused on the structure of the precursor. Herein, we showed a systematic survey to reveal the structural evolution of Ni-Rich Ni-Co-Al hydroxide precursor under different synthesis conditions. Under a certain pH, the higher the ammonia concentration is, the larger the primary particle size gradually becomes. Simultaneously, at the low pH (pH = 11.2), Ni-Rich Ni-Co-Al hydroxide precursor is consisted of four phases: Ni(OH)2, AlO(OH), Al(OH)3 and Al2(SO4)3 with the space group P-3 m1, Cmcm, P21/n and R-3, respectively. At the harsh pH (pH = 11.8), the precursor is consisted of two phases: Ni(OH)2, and Al(OH)3 with the space group P-3 m1 and P21/n, respectively. This study provided a significant guidance for the design of the precursor with special structure.

Decorative ornamental plants have been applied as hyperaccumulators/phytoremediators to a wide spectrum of heavy metal contaminants. In this study, pot culture experiments were conducted to investigate the Sn tolerance and accumulation in Impatiens balsamina L., Mirabilis jalapa L. and Tagetes erecta L., in order to assess the possibility of these three ornamental plants to be used as phytoremediators of Sn-contaminated soil. Results show that all three plants exhibited strong tolerance to Sn contamination, and no significant visual toxicity was observed for all three plants grown under most of the Sn treatments. The amount of Sn accumulated in the three plants was positively correlated with the Sn concentration in the soil. The order of the Sn accumulative capacity was Impatiens balsamina &gt, Mirabilis jalapa &gt, Tagetes erecta. Impatiens balsamina and Tagetes erecta showed a low translocation ability (TF) (&lt, 1), and the roots accumulated the highest Sn concentration, but Impatiens balsamina showed a relatively high bioconcentration factor (BCF, Sn concentration in each part &gt, 100 mg/kg after Sn treatment of 500 mg/kg). Meanwhile, the TF of Mirabilis jalapa was &gt, 1, and the fluorescence accumulated the most Sn. In combination with the adaptation to high concentrations of various heavy metals, these three ornamental plants are potential candidates for Sn mining tailings or contaminated soil.

As a safe and sustainable cathode material for reversible Na-ion storage, the electrochemical performance of Na3.32Fe2.34(P2O7)2 with high operational safety can be enhanced via ion-doping engineering strategy. However, the rationale behind has remained unclear. In this study, we partially replace the Na+ and Fe2+ cations with K+ and Mg2+, respectively, where the K+ and Mg2+ dopants serve as pillars to support the crystallographic framework and thus reduce potential hysteresis. It is found that, compared to K doping at the Na site, Mg doping at the Fe site contributes to a more stable crystal structure and renders higher rate capability and cycling stability due to the inhibition of Fe migration and the reduction of structural disorder. The cation pillar strategy reported herein may shed light on enhancing cycling performance of other cathode materials for stable storage of not only Na ions but also other metals.

Due to the highest theoretical specific capacity of 4200 mA h g−1 for Li4.4Si, silicon(Si)-based materials could fulfill the increasing demands of high-energy lithium-ion batteries (LIBs). However, the intrinsic huge volume expansion during the lithiation/delithiation process results in rapid capacity decay and short cycle life and restricts the satisfactory electrical performance of Si-based anodes. Binder plays an important role of maintaining the contact integrity between active material, conductive additive and the current collector, thereby reducing the pulverization of the Si particles during charge/discharge. Here, the review systematically summarizes the synthesis methods, design principles and working mechanisms, including chemical composition, superstructure, and various interactions between different functional moieties of synthetic binders and natural biomass binders, to reveal the structure-composition-performance relationship, offer practical solutions to challenging problems associated with defects of Si-based electrode materials in LIBs and aim at exploiting new family of binders that could be used in industrial level as well as providing design principles for other electrode binders in rechargeable batteries.

The storage of renewable energy depends largely on sustainable technologies such as sodium-ion batteries with high safety, long lifespan, low cost, and non-toxicity. Pyrophosphate Na3.32Fe2.34(P2O7)2 cathode could meet this requirement, however, its structural stability needs to be further enhanced for practical purposes. To overcome this problem, Na-deficient Na3.32Fe2.11Ca0.23(P2O7)2 with exceptional stability is prepared by Ca selective doping in this work. In operando synchrotron-based X-ray diffraction (SXRD) and in situ X-ray absorption near edge spectroscopy (XANES) results reveal that the prepared Na3.32Fe2.11Ca0.23(P2O7)2 is a single-phase solid-solution reaction with high reversibility. A strong correlation between the voltage curve and lattice parameters is deciphered for the first time. Additionally, the atomic-doping-engineering strategy could significantly enhance the thermal and electrochemical stability of the electrode materials, contributing to their good structural reversibility and enhanced operational safety. Specifically, after 1000 cycles at 1 C, the Ca doped electrode achieves a high capacity retention of 81.7%, which is much better than that of the un-doped electrode (15.5%). Our work may pave a new avenue for designing safe and low-cost cathode materials for battery applications with long cycle life.

One of the most prevalent forms of dementia is Alzheimer's disease (AD) which causes severe memory impairment within humans. As such, research into the early diagnosis of AD is essential to help treatment, which has led to significant advances in fluorescence imaging. Unfortunately, modern medicine and biology place increasingly strict requirements for fluorescent probes. Therefore, over recent years, researchers have taken strides to develop novel fluorescent molecular probes, with properties suitable for modern clinical applications, including low phototoxicity, weak background interference, deep tissue penetration, enhanced specificity, strong binding affinity, and suitable permeability through the blood–brain barrier (BBB). From these recent research results, many novel concepts for molecular design and fluorescence techniques have emerged. Herein, we present strategies towards the development of probes capable of meeting the advanced clinical requirements. As part of this review, we will summarize the characteristic enzymes and proteins involved in AD progression, including Amyloid-β, β-secretase, tau protein, monoamine oxidases, and methionine sulfoxide reductase. Then, we will evaluate some of the early probes and summarize the recent advancements made in the design of probes suitable for clinical applications, from which several strategies have emerged, such as increasing permeability to the blood–brain barrier, enhancing specificity by boosting binding affinity, and improving optical properties for in vivo imaging, etc. Then to conclude current strategies for early stage diagnosis of AD will be presented, and the opportunities as well as the remaining challenges will be outlined.

// Xinying Xue 1, 2 , Yuxia Liu 3 , Yong Wang 1 , Mingming Meng 4 , Kaifei Wang 2 , Xuefeng Zang 5 , Sheng Zhao 6 , Xiaohua Sun 7 , Lei Cui 8 , Lei Pan 1 , Sanhong Liu 9 1 Department of Special Medical Treatment-Respiratory Disease, Beijing Shijitan Hospital, Capital Medical University, Beijing, China 2 Department of Respiratory Diseases of Chinese PLA General Hospital, Beijing, China 3 Department of Research, Peking Union Medical Collage Hospital, Beijing, China 4 Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, Beijing, China 5 Department of Intensive Care Unit, Beijing Shijitan Hospital, Capital Medical University, Beijing, China 6 Department of Cardiology, Peking University Ninth School of Clinical Medicine, Beijing Shijitan Hospital, Beijing, China 7 Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai, China 8 Department of Central Laboratory, Beijing Shijitan Hospital, Capital Medical University, Beijing, China 9 Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China Correspondence to: Lei Pan, email: leipan2010@163.com Sanhong Liu, email: liush@shanghaitech.edu.cn Lei Cui, email: cuileite@aliyun.com Keywords: non-small cell lung carcinoma, miR-21, miR-155, SOCS1, SOCS6 Received: July 11, 2016 Accepted: October 25, 2016 Published: November 02, 2016 ABSTRACT Lung cancer remains the leading cause of cancer-associated death worldwide. MiR-21 and miR-155 are the most amplified miRNAs in non-small cell lung carcinoma (NSCLC), and are critical promoters of NSCLC progression. However, it remains unclear how miR-21 and miR-155 induce cancer progression, and whether these miRNAs share common targets, such as tumor suppressor genes required to prevent NSCLC. Here we report that miR-21 and miR-155 levels are elevated in NSCLC and are proportional to the progression of the disease. In addition, miR-21 and miR-155 share nearly 30% of their predicted target genes, including SOCS1 , SOCS6 , and PTEN , three tumor suppressor genes often silenced in NSCLC. Consequently, antagonizing miR-21, miR-155 or both potently inhibited tumor progression in xenografted animal models of NSCLC. Treatment with miR-21 and miR-155 inhibitors in combination was always more effective against NSCLC than treatment with a single inhibitor. Furthermore, levels of miR-21 and miR-155 expression correlated inversely with overall and disease-free survival of NSCLC patients. Our findings reveal that miR-21 and miR-155 promote the development of NSCLC, in part by downregulating SOCS1 , SOCS6 , and PTEN . Combined inhibition of miR-21 and miR-155 could improve the treatment of NSCLC.

Gold-catalyzed cyclization of 2-alkynyl-N-propargylanilines provides a step-economic method for the construction of three-dimensional indolines. In this article, the M06 functional of density functional theory was employed to gain deeper insights into the reaction mechanism and the associated intriguing experimental observations. The reaction was found to first undergo Au(I)-induced cyclization to form an indole intermediate, 1,3-propargyl migration, and substitution with the substrate 2-alkynyl-N-propargylaniline (R1) to generate the intermediate product P1, an allene species. Subsequently, Au(I)-catalyzed conversion of P1 into the final product P2, an indoline compound, occurs first through direct cyclization rather than via the previously proposed four-membered carbocycle intermediate. Thereafter, water-assisted oxygen heterocycle formation and proton transfer generate the final product. The calculated activation free energies indicate that P1 formation is 5.9 times slower than P2 formation, in accordance with the fact that P1 formation is rate-limiting. Futhermore, the intriguing experimental phenomenon that P2 can be accessed only after almost all the substrate R1 converts to P1 although P1 formation is rate-limiting was rationalized by employing an energetic span model. We found the initial facile cyclization to form a highly stable indole intermediate in the formation of P1 is the key to the intriguing experimental phenomenon.

Plant phenology plays a significant role in regulating carbon sequestration period of terrestrial ecosystems. Remote sensing of land surface phenology (LSP), i.e., the start and the end of the growing season (SOS and EOS, respectively) in evergreen needleleaf forests is particularly challenging due to their limited seasonal variability in canopy greenness. Using 107 site-years of CO 2 flux data at 14 evergreen needleleaf forest sites in North America, we developed a new model to estimate SOS and EOS based entirely on the Moderate Resolution Imaging Spectroradiometer (MODIS) data. We found that the commonly used vegetation indices (VI), including the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI), were not able to detect SOS and EOS in these forests. The MODIS land surface temperature (LST) showed better performance in the estimation of SOS than did a single VI. Interestingly, the variability of LST (i.e., the coefficient of variation, CV_LST) was more useful than LST itself in detecting changes in forest LSP. Therefore, a new model using the product of VI and CV_LST was developed and it significantly improved the representation of LSP with mean errors of 11.7 and 5.6 days for SOS and EOS, respectively. Further validation at five sites in the Long Term Ecological Research network (LTER) using camera data also indicated the applicability of the new approach. These results suggest that temperature variability plays a previously overlooked role in phenological modeling, and a combination of canopy greenness and temperature could be a useful way to enhance the estimation of evergreen needleleaf forest phenology of future ecosystem models.

Malonyl-CoA decarboxylase (MCD) can control the level of malonyl-CoA in cell through the decarboxylation of malonyl-CoA to acetyl-CoA, and plays an essential role in regulating fatty acid metabolism, thus it is a potential target for drug discovery. However, the interactions of MCD with CoA derivatives are not well understood owing to unavailable crystal structure with a complete occupancy in the active site. To identify the active site of MCD, molecular docking and molecular dynamics simulations were performed to explore the interactions of human mitochondrial MCD (HmMCD) and CoA derivatives. The findings reveal that the active site of HmMCD indeed resides in the prominent groove which resembles that of CurA. However, the binding modes are slightly different from the one observed in CurA due to the occupancy of the side chain of Lys183 from the N-terminal helical domain instead of the adenine ring of CoA. The residues 300 - 305 play an essential role in maintaining the stability of complex mainly through hydrogen bond interactions with the pyrophosphate moiety of acetyl-CoA. Principle component analysis elucidates the conformational distribution and dominant concerted motions of HmMCD. MM_PBSA calculations present the crucial residues and the major driving force responsible for the binding of acetyl-CoA. These results provide useful information for understanding the interactions of HmMCD with CoA derivatives. Proteins 2016; 84:792-802. © 2016 Wiley Periodicals, Inc.

Previously, we demonstrated specific accumulation into bacteria of a 12-mer phosphorodiamidate morpholino (MORF) oligomer complementary to a ribosomal RNA (rRNA) segment found in all bacteria using the universal probe called Eub338 (Eub). Here, two MORF oligomers Eco and Kpn with sequences specific to the rRNA of Escherichia coli (Eco) and Klebsiella pneumoniae (Kpn) were investigated along with Eub and control (nonEub).To determine bacterial rRNA binding, oligomers were tagged with Alexa Fluor 633 (AF633) for fluorescence in situ hybridization (FISH) and fluorescence microscopy, and radiolabeled with technetium-99m (Tc-99m) for biodistribution and SPECT imaging in infected mice.By both FISH and fluorescence microscopy, Eub showed a positive signal in both E. coli and K. pneumoniae as expected, and Kpn showed significantly higher accumulation in K. pneumoniae with near background in E. coli (p 0.01). Conversely, Eco was positive in both E. coli and K. pneumoniae, hence nonspecific. As determined by biodistribution, the accumulation of [(99m)Tc]Kpn was higher in the thigh infected with live K. pneumoniae than with live E. coli (p = 0.05), and significantly higher than with heat-killed K. pneumoniae (p = 0.02) in the target thigh. By SPECT imaging, the accumulation of [(99m)Tc]Kpn was obviously higher in its specific target of K. pneumoniae compared to an E. coli infected thigh.Kpn complementary to the rRNA of K. pneumoniae, labeled with Tc-99m or AF633, demonstrated specific binding to fixed and live K. pneumoniae in culture and in infected mice such that Tc-99m-labeled Kpn as the MORF oligomer may be useful for K. pneumoniae infection detection through imaging.

With the aid of density functional theory (DFT) calculations, the Pd-catalyzed reactions of aryl iodide with unsymmetrical alkyne leading to two products containing C(sp 3 )−I bond ( P3 and P4 ) and one product containing a three-membered carbocyclic unit ( P5 ), have been studied theoretically. It is found that both the alkyne insertion and the subsequent C C bond insertion involved in the reaction are the major thermodynamic driving forces. The alkyne insertion instead of the C(sp 3 )−I reductive elimination is predicted to be rate-determinant. Similar barrier heights calculated for the two insertion modes of unsymmetrical internal alkyne ( TS 3-4 and TS 3′-4′ ) lead to the products P3 (47.2%) and P4 + P5 (48.8%) having similar product yields. The intriguing formation of the product containing a three-membered carbocyclic unit ( P5 ) was investigated in details. The second alkene insertion is found to be kinetically more favored than the C(sp 3 )−I reductive elimination, leading to product P5 (39.0%) more productive than P4 (9.8%). The remarkably thermodynamically favored β−H elimination is the key factor enabling formation of P5 . Why significant bulky phosphine ligand such as P(t-Bu) 3 instead of small one such as P(Me) 3 was employed experimentally have also been rationalized based on our calculation results.

Pd-catalyzed decarboxylative Heck-type coupling of 3-chlorobenzo[b]thiophene-2-carboxylic acids with styrenes have been developed as an efficient strategy for the construction of functionalized benzo[b]thiophenes. Theoretical analysis shows that AgCl generated during the reaction, instead of Pd, π-coordinates with the carboxyl O atom, making easy the rate-determining CO2 dissociation. The divergent reactivities of the Cl-substituted and H-substituted 3-benzo[b]thiophene-2-carboxylic acids are mainly due to the presence of the Cl substituent, which reduces the adjacent π-π interplay, thereby significantly contributing to decarboxylation. Therefore, the presence of both AgCl and the Cl substituent are of key importance in ensuring the occurrence of the reaction under the given conditions.

The reaction features combination of C H activation and ring opening of cyclopropanol was studied with the aid of DFT calculations. With the reaction of N-pyrimidylindoline and 1-benzylcyclopropanol as an example to accomplish the alkylation, we found the order of C H activation/ring opening is difficult to occur. Instead, the order of ring opening/C H activation is predicted to be more reasonable, which circumvents the N→Rh bond breaking. Two catalytic cycles were suggested. The first cycle relates to the catalytic oxidation of cyclopropanol by Cu(II) to generate an intermediate product, the vinyl ketone. The mechanism mainly involves prior ring opening of cyclopropanol and β-H elimination. The second cycle relates to the product formation from the resultant intermediate product, in which the C H activation of N-pyrimidylindoline, C C bond insertion of the intermediate product and protonation are included. The insights gained in this study are expected to be pertinent in other reaction systems involving combination of C H activation and ring opening.

In order to improve the engineering feasibility of the memristive cellular neural network, a new memristor model with the smooth characteristic curve is designed. Based on the new memristor model, a new four-dimensional chaotic memristive cellular neural network (CNN) system is constructed, and its chaotic dynamic behaviors are analyzed. It can be applied to the secure communication based on the chaos synchronization control. Because both the external disturbances and uncertainties of internal parameters are maybe in the practical secure communication system, sliding mode control is used to perform the chaos synchronization between the sender and receiver. A new terminal sliding mode surface is designed to make the error system converge to zero in a finite time. Simulation results show that the new terminal sliding mode control has good robustness to the external disturbances and uncertainties of internal parameters, and the new chaotic memristive CNN system can be used in the secure communication by the chaos synchronization based on sliding mode control.

A theoretical and computational study was performed on the nitrene-participating three-component carboamination of dienes. The reaction proceeds mainly through C–H activation, olefin insertion, metal nitrenoid formation, and selective C N coupling. The role of solvent effect enables the extrusion of carbon dioxide to generate the key metal nitrenoid being not concerted but stepwise. The Rh = N was indicated by HOMO-LUMO interactions that the backdonation is dominant and hence showing the electron withdrawing behavior of nitrene. Regioselectivity for C C bond formation, E-type product, and 1,4-carboamination was discussed.

Layered manganese oxides cathodes of sodium-ion batteries show high energy density, but limited stability and rate capacity. Our previous studies have evidenced that layer-tunnel hybrid structure possesses both better rate performance and cyclic stability. Nevertheless, the complex phase transition is still ineluctable, leading to unsatisfying cycling performance. Be different from the previous study of ion-doping, this study demonstrates that the highly Na+-conductive Na2Ti6O13 coating can also effectually suppress the phase transition and improve the structure stability, air stability. Notably, the 3 wt % Na2Ti6O13 coated sample exhibits a primary capacity of 175.6 mA h g−1at 0.1 C between 2.0 and 4.1 V. And a capacity retention of 86.7% at 2C after 100 cycles. The Raman results show that the local lattice distortion around Mn3+ and Mn4+ ions is effectively suppressed. And the air stability also has been significantly improved. This study could provide a valid tactics into the surface modification of high-performance composite structure cathode materials for SIBs.

Polymer-ceramic composite electrolyte is an effective solution for developing high-performance and flexible all-solid-state lithium metal battery. However, the key bottleneck of composite electrolyte including low ionic conductivity and high interfacial impedance have impeded their industrialization in solid electrolyte lithium batteries. Here we present a polymer-ceramic hybrid electrolyte (polyethylene oxide (PEO)/polyvinylidene fluoride (PVDF)/Li6.4La3Zr1.4Ta0.6O12 (LLZTO)) is designed and modified by trace amount of liquid electrolyte. The addition of PVDF can not only reduce the crystallinity of PEO polymer, but also intensify the affinity between liquid electrolyte and the composite electrolyte. Furthermore, the interfacial modification can synchronously achieve the intimate connection, low interfacial impedance between the electrodes and solid electrolytes by forming the viscoelastic and stable layer. Due to the artful design, the solid-state battery deliver excellent performance. The Li symmetric cells show excellent interface stability without short circuits for 1000h. The assembled LiFePO4/Li cells exhibit a discharge capacity of 160.1 mA h g−1 after 200 cycles at 0.4C and 143.3 mA h g−1 at 5C. The composite solid electrolyte provides an effective and feasible methods to solve the interfacial issues and develop high performance solid lithium metal batteries.

Li- and Mn-rich layered cathode materials (LMR) have been widely studied for their ultrahigh energy density. Unfortunately, the rapid potential decay and capacity degradation during cycling hinder their commercialization process. In this work, Mg2+ cation and PO43− polyanion dual elements coupling effect induced lattice modification strategy is developed to address these drawbacks for a typical lithium-rich material. The structural characteristic, chemical composition, valence state and elemental distribution of the materials are investigated by scanning electron microscopy, X-ray diffraction, inductively coupled plasma optical emission spectroscopy, focused ion beam and high-resolution transmission electron microscopy, respectively. Mg2+ and PO43− co-modified lithium-rich cathode material shows excellent electrochemical properties. It provides an improved initial coulombic efficiency of 87 % and ultrahigh initial discharge capacity of 307 mA h g-1 during a cut-off voltage of 2.0–4.8 V and a current density of 25 mA g-1. In conclusion, the Mg2+ and PO43− co-modified material exhibits not only significantly improved rate performance (150.7 mA h g−1 @ 5 C) but also markedly improved cycling stability (83 % @ 1 C @ 300 cycles).

Although the properties of high energy density and low costs have contributed the extensive research of Lithium-rich layered oxide materials as a candidate of next-generation cathode materials in lithium-ion batteries, present poor cyclic life, and fast voltage fade hinder their large-scale commercial applications. Here, we propose a novel cation/anion (Na+/PO43-) co-doping approach to mitigate the discharge capacity and voltage fade of Co-free Li1.2Ni0.2Mn0.6O2 cathode. Results show that the synergistic effect of cation/anion can obviously promote the long cycle stability and rate performance by inhibiting the phase transformation of layered structure to spinel or rock-salt structure and stabilizing the well-order crystal structure during long cycle. The co-doped sample exhibits an outstanding cycle stability (capacity retention of 86.7% after 150 cycles at 1 C) and excellent rate performance (153 mAh g−1 at 5 C). The large ionic radius of Na+ can expand the Li slab for accelerating the Li diffusion and the large tetrahedral PO43- polyanions with high electronegativity stabilize the local structure for improving the electrochemical performance.

Mass spectrum (MS) is one of the most commonly used tools for qualitative and quantitative analysis of glycans. However, due to the complexity of biological samples and the low ionization efficiency of glycans, these need to be purified and derivatized prior to MS analysis. Existing purification strategies require a combination of multiple methods and are cumbersome to operate. Here, we propose a new method for the purification of glycoprotein N/O-glycans and their derivatives using a hand-packed absorbent cotton hydrophilic interaction chromatography column (HILIC). The method's reliability and applicability were verified by purifying N/O-glycans and the derivatives of standard glycoproteins, such as chicken albumin and porcine stomach mucin. Stable isotope labelling was used to compare the glycans’ recovery following different purification methods. Absorbent cotton HILIC was also successfully applied for the analysis of human serum and fetal bovine serum glycoprotein N-glycans. Finally, testing revealed high binding capacity (9 mg/g−1 maltohexaose/absorbent cotton) and good recovery (average recovery was 91.7%) of glycans. Compared with traditional procedures, the proposed purification method offers considerable advantages, such as simplicity, high efficiency, economy, universality, and broad applicability for the pretreatment of glycans and their derivatives in biological samples prior to MS analysis.

Density functional theory (DFT) calculations were used to explore the Au(I)-catalyzed selective [4 + 1] annulations of cyclopropyl- and H-substituted 1,4-diyn-3-ols with isoxazole. The results indicated that after the N-nucleophilic attack of isoxazole, instead of obtaining the α–hydroxy gold carbene intermediate proposed experimentally, a concerted three-step forward product by isoxazole O[sbnd]N cleavage, 1,2-phenylalkyne shift and the hydroxyl H shift was identified as the key intermediate, for the reaction proceeding either via an Au-assisted C[dbnd]C double-bond rotation to produce the Z-isomeric enone or via two different Au-assisted C[dbnd]C rotations to furnish the E-configured enone depending on the substituents used. Further theoretical investigations indicated that the chemoselective step is the nucleophilic cyclization but not the C[dbnd]C double-bond rotation. The chemoselective preference for the Z-configured product using the cyclopropyl substitutent was attributed to two factors: i) the additional O[tbnd]H[sbnd]N hydrogen bonding interaction stabilizes the rate-determining cyclization TS leading to the Z-product, and ii) further Z-E product-isomerization is blocked due to significant structural deformation being involved. In contrast, using the H substituent results in a reversed chemoselectivity with exclusive formation of the E-configured enone, which is closely related to the smaller entropy effects involved.

Tissular H2S plays important role in neuroprotection, cardioprotection and angiogenesis. Herein, we develop a new fluorescent probe (Z)-4-(2-(6-(2,4-dinitrophenoxy)naphthalen-2-yl)vinyl)-1-methylpyridinium (EMII-H2S) for tissular imaging of H2S. EMII-H2S allows for sensitive response toward H2S under the excitation of both one-photon (410 nm) and two-photon (750 nm). Asymmetric electron structure contributes to the large stokes shift of 160 nm. With the better absorbance (39000 M−1cm−1), quantum yield (0.201) as well as the two-photon absorption cross-section (119 GM), EMII-H2S provides the higher brightness in response to H2S under either one-photon (eΦ = 7638) or two-photon modes (δΦ = 23.8), which compare favorably with many other highly bright fluorescent probes. EMII-H2S is applied in imaging of cellular endogenous H2S and tissue imaging at depths of 160 μm–200 μm in mouse liver. With the satisfactory properties, EMII-H2S is used to estimate the dynamic H2S release during metabolism of two type of H2S donors, demonstrating that the thiovaline provided the long-lasting H2S production contrary to the rapid burst caused by NaHS. EMII-H2S proves to be an effective tool for imaging tissular H2S, which is of great significance for the visual analysis of gasotransmitters in tissue.

Hydrogen peroxide (H2O2) is emerging as a new second messenger, which plays vital roles in intracellular signaling, thereby triggering physiological variations in terms of proliferation, differentiation, and migration. As known, cell mitosis has close association to the intracellular level of H2O2, which contribute to the significant effects on brain development, especially during the critical period of immaturity. Unfortunately, imaging H2O2 in a mammalian brain is still challenging. Herein, to further investigate the biological roles of endogenous H2O2 in cell mitosis, we develop a near-infrared ratiometric fluorescent probe Cy-PFS for specifically imaging endogenous H2O2 in cells and in vivo. Employing the probe Cy-PFS, we examine the critical effects of endogenous H2O2 on proliferation of cells in live hippocampal neurons cells, and our results provide strong evidence for H2O2 signaling in cell mitosis through growth factor signaling. Furthermore, we successfully demonstrate the close association of e...

Organisms have built up immunological systems, where mitochondrial SO

Glaucoma is a chronic neurodegenerative disease which produces damage to the optic nerve and causes sightlessness. Current remains lack of effective method for glaucoma. Lycium barbarum polysaccharides (LBPs) have pleiotropic effects on various diseases. However, the effect of LBPs on glaucoma remains unclear. The study aimed to clarify the protective effect of LBPs against hydrogen peroxide (H2O2)-induced oxidative damage in human trabecular meshwork (HTM) cells. HTM cells were exposed to H2O2 (0–400 μM) for 24 h to construct an oxidative damage model. Then, the different concentrations of LBPs (0–500 μg mL−1) were used to pre-treated HTM cells, and cell viability, apoptosis, protein levels of pro−/cleaved-caspase-3 and pro−/cleaved-caspase-9, and reactive oxygen species (ROS) generations were detected. MicroRNA (miR)-4295 inhibitor and its control were transfected into HTM cells, and the biological functions of miR-4295 were assessed in H2O2 and LBPs treated cells. Phosphatidylinositol 3-kinase (PI3K)/protein Kinase B (AKT) and extracellular regulated protein kinases (ERK) pathways were determined by western blot assay. LBPs significantly promoted cell viability, reduced apoptosis, declined cleaved-caspase-3/-9 and ROS level in HTM cells after H2O2 administration. MiR-4295 expression was up-regulated in H2O2 and LBPs treated cells. The protective effect of LBPs on H2O2-injured HTM cells was obviously reversed by miR-4295 inhibition. LBPs activated PI3K/AKT and ERK signaling pathways through up-regulation of miR-4295 in H2O2-injured HTM cells. These data demonstrated that LBPs alleviated H2O2-induced injury by up-regulation of miR-4295 in HTM cells, indicating the protective effect of LBPs on HTM cells against oxidative damage.

In this study, Li3AlF6 was employed to simulate the molten salt LiF–BeF2 to explore its pyrohydrolysis behavior and that of its components, i.e., LiF and AlF3, respectively. The influence of the accelerators α-Al2O3 and AlF3 on the pyrohydrolysis of LiF and Li3AlF6 was investigated. Finally, the solid pyrohydrolytic products were characterized by means of X-ray diffraction, and the corresponding reaction mechanisms were proposed. These experimental results indicated that AlF3 was completely hydrolyzed to the corresponding oxide α-Al2O3 at 650 °C in 1 h, whereas the complete hydrolysis of LiF and Li3AlF6 required the assistance of either α-Al2O3 or AlF3 under the same conditions. The influence of the accelerator α-Al2O3 and AlF3 on the pyrohydrolytic behavior of Li3AlF6 provides references for future research studies on the pyrohydrolysis of LiF–BeF2 and multi-component molten salts.

Interactions between metals and anaerobic ammonium oxidizing consortia substantially affect the quality of wastewater treatment plant effluent. In this study, we conducted acid-base titrations to ascertain the surface reactivity and proton adsorptive capacity of anammox consortia. A combination of titration data modeling and infrared spectroscopy suggested the presence of carboxyl, amine, and hydroxyl groups. Cd adsorption experiments demonstrate that 1 g of dry biomass could bind an equivalent of 7.12 × 10−6 mol/L of Cd. Density functional theory calculations further reveal that carboxyl and hydroxyl groups are able to form stable Cd complexes. Furthermore, considerable carboxyl and hydroxyl groups promote bacterial aggregation, and thus solid-liquid separation. The results of this study highlight the potential role of anammox consortia in adsorbing metal cations, and thus help to improve the understanding of the universally significant contribution of anammox consortia at the detoxification of metal cations in wastewater treatment systems.

Lapatinib and capecitabine have been widely used in the therapy of breast cancer. However, long-term use of lapatinib and capecitabine often causes the most common side effect diarrhea, which limit the medicine use. Fructus mume (F. mume) has been proved to be effective to treat chronic diarrhea with few side effects. The compounds from F. mume were extracted by using an ethanol method. Extracts of F. mume (EFM) were analyzed by HPLC. We investigated the protective effects of EFM on the diarrhea caused by lapatinib and capecitabine. From March 1st, 2016 to June 1st, 2017, 208 breast cancer patients with diarrhea caused by lapatinib and capecitabine were recruited. The patients were evenly assigned into two groups: EG group (the patients took 100 mg EFM daily) and CG group (the patients took placebo daily). The effects of EFM on diarrhea and gastrointestinal symptoms were measured by a semiquantitative method seven-point Likert scale. Overall quality of life was measured by SF-36 questionnaire and Hospital Anxiety and Depression Scale (HADS). The HPLC analysis showed that there were three components in EFM, including citric acid, 5-hydroxymethylfurfural (5-HMF), and chlorogenic acid. Breast cancer types were observed by using Hematoxylin and eosin (H&E) stain. The breast cancer can be divided into leaflet, gland and fibroblast types. Patient age, skin metastases, treatment, and grade 1 diarrhea were significant risk factors associated with for grade 2 diarrhea. EFM reduced diarrhea and gastrointestinal symptoms by reducing the average scores of the diarrhea symptom and seven-point Likert scale, and improved life quality of patients significantly by improving SF-36 scores and reducing HADS scores when compared to that in the CG group after 6-week therapy and further 4-week follow-up (P < 0.05). EFM may be a potential choice for the diarrhea therapy in breast cancer patients.

PKD2L1, also termed TRPP3 from the TRPP subfamily (polycystic TRP channels), is involved in the sour sensation and other pH-dependent processes. PKD2L1 is believed to be a nonselective cation channel that can be regulated by voltage, protons, and calcium. Despite its considerable importance, the molecular mechanisms underlying PKD2L1 regulations are largely unknown. Here, we determine the PKD2L1 atomic structure at 3.38 Å resolution by cryo-electron microscopy, whereby side chains of nearly all residues are assigned. Unlike its ortholog PKD2, the pore helix (PH) and transmembrane segment 6 (S6) of PKD2L1, which are involved in upper and lower-gate opening, adopt an open conformation. Structural comparisons of PKD2L1 with a PKD2-based homologous model indicate that the pore domain dilation is coupled to conformational changes of voltage-sensing domains (VSDs) via a series of π–π interactions, suggesting a potential PKD2L1 gating mechanism., Polycystic kidney disease 2-like 1 protein (PKD2L1) is a voltage-dependent calcium-dependent nonselective ion channel involved in sour taste perception and regulation of pH-dependent action potential of spinal cord neurons. Here the authors present the 3.4 Å cryo-EM structure of PKD2L1 in the open state and propose a model for the gating mechanism.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive type of interstitial pneumonia with unknown causes, poor prognosis and no effective therapy available. Circular RNAs (circRNAs), which serve as potential therapeutic targets and diagnostic biomarkers for certain diseases, represent a recent hotspot in the field of RNA research. In the present study, a total of 67 significantly dysregulated circRNAs were identified in the plasma of IPF patients by using a circRNA microarray. Among these circRNAs, 38 were upregulated, whereas 29 were downregulated. Further validation of the results by polymerase chain reaction analysis indicated that Homo sapiens (hsa)_circRNA_100906, hsa_circRNA_102100 and hsa_circRNA_102348 were significantly upregulated, whereas hsa_circRNA_101225, hsa_circRNA_104780 and hsa_circRNA_101242 were downregulated in plasma samples of IPF patients compared with those in samples from healthy controls. The majority of differentially expressed circRNAs were generated from exonic regions. The host genes of the differentially expressed circRNAs were involved in the regulation of the cell cycle, adherens junctions and RNA transport. The competing endogenous RNA (ceRNA) network of the circRNAs/micro(mi)RNAs/mRNAs indicated that circRNA-protected mRNA participated in transforming growth factor-β1, hypoxia-inducible factor-1, Wnt, Janus kinase, Rho-associated protein kinase, vascular endothelial growth factor, mitogen-activated protein kinase, Hedgehog and nuclear factor κB signalling pathways or functioned as biomarkers for pulmonary fibrosis. Furthermore, luciferase reporter assays confirmed that hsa_circRNA_100906 and hsa_circRNA_102348 directly interact with miR-324-5p and miR-630, respectively, which were downregulated in IPF patients. The present study provided a novel avenue for exploring the underlying molecular mechanisms of IPF disease.

Presently, developing effective anti-colon cancer drugs still remains to be important. Ginkgolic acids (GA), as a botanical drug extracted from the seed coat of Ginkgo biloba L., possess various bioactive properties. Our findings, for the first time, indicated that GA suppressed colon cancer cell proliferation, migration and invasion. GA led to cell death through G0/G1 phase arrest. In addition, apoptosis was significantly induced by GA treatment. The intrinsic apoptosis pathway was included, proved by the release of cytochrome c (Cyto-c) from the mitochondria into the cytosol. GA-induced autophagy was supported by the dose-dependent increase of LC3BII, autophagy-related gene-5 (ATG-5) and Beclin-1. Notably, silencing ATG-5 further reduced the cell viability and enhanced apoptosis in GA-treated colon cancer cells, indicating that GA-induced apoptosis rather than autophagy contributes to colon cancer cell death. And mammalian target of rapamycin complex 1 (mTORC1) was dose-dependently reduced by GA, evidenced by the reduction of p-mTOR, p-p70 ribosomal S6 kinase (p70s6k) and p-pras40. Moreover, GA markedly resulted in reactive oxygen species (ROS) generation, along with increased H2O2 and O2−. However, blocking ROS generation using its scavenger, NAC, significantly recovered GA-induced cells death, supported by the increase of cell viability, and the decrease of apoptosis. The expressions of autophagy- and cell cycle arrest-related molecules, as well as mTORC1 were also reversed by N-acetyl- l -cysteine (NAC) in GA-treated cells. In vivo, GA reduced tumor growth without toxicity to animals. In conclusion, our study illustrated that GA caused G0/G1 phase arrest and triggered intrinsic apoptosis and autophagy modulated by ROS generation in human colon cancer, elucidating that GA might be considered as a potential agent for colon cancer therapy.

Cletus punctiger is a famous economic crop pest in China, especially for rice. Here, we first reported the complete mitochondrial genome sequence of this pest. The mitochondrial genome is 16,166 bp in length, including 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and 1 control region (D-Loop). The maximum likelihood (ML) phylogenetic tree confirmed that C. punctiger belonged to the Coreidae subfamily.

With regard to the study of temperament and motivation in young children, exuberance, an important temperamental characteristic of the approach motivational system, has been relatively understudied in comparison with behavioral inhibition. However, due to the relationship between exuberance and behavioral regulation (e.g., problem behavior, task persistence), it is an important topic of study. Accordingly, this study examined whether the incentive value of goals moderated the relationship between exuberance and persistence in 109 Chinese preschoolers. Children's temperamental exuberance was assessed by behavioral observation and parental report. Their persistence was measured in two goal-blocked contexts (tower-building [TB] and locked box [LB]). In each task, children were randomly assigned to either a high- or low-incentive condition designed to vary the incentive value of a given goal. Results suggested that exuberance was positively associated with persistence in the high-incentive condition of TB and in both conditions of LB. The results highlight the incentive value of goals as an important factor for behavioral regulation development in exuberant Chinese children.

In this Letter, different from conventional pretargeting, an additional novel DNA polymer with multiple copies of a target was first designed to be administrated between the antitumor antibody, and the labeled effector served as an amplification pretargeting strategy. Two phosphorothioate DNA strands, a bridging and a target strand, were hybridized to form a polymer. Polymer size, as a function of molar ratios, was then monitored by size exclusion HPLC and electrophoretic mobility shift assay. Moreover, binding efficiency of polymers with the radiolabeled effector and polymer size after hybridization were measured by HPLC as well. As the polymer was expected to produce more binding sites that would be targeted by effectors, amplification pretargeting can greatly improve accumulation of effectors in tumor. This novel proof-of-concept was then well demonstrated by the in vitro test of signal amplification in antibody-binding protein L coated plate and LS174T cells. Compared to conventional pretargeting, significantly increasing radioactive signal was observed in this designed amplification pretargeting, which would serve as a useful paradigm of the potential of oligomer polymers to improve pretargeting and other related approaches.

Phytochelatins chelate heavy metal ions to decrease their toxicity. The chelates are then transferred to, and stored in, the vacuole. Phytochelatin synthase (PCS), which is involved in phytochelatin synthesis, is thought to be a key enzyme for phytoremediation. In this study, a PCS gene encoding phytochelatin synthase was cloned from poplar (Populus tomentosa Carr.), a widely grown model woody plant that accumulates high levels of heavy metals, especially cadmium. Poplar is considered to have potential applications in phytoremediation. The full-length PtPCS cDNA (1512-bp) encoded a polypeptide of 503 amino acid residues. The PtPCS cDNA was transferred into tobacco by Agrobacterium-mediated leaf disk transformation. The transgenic and wild-type (WT) lines of tobacco were subjected to a one time Cd treatment (90 μmol Cd2+) for 30 days, and then evaluated to determine their Cd tolerance. We evaluated morphological and physiological indices including leaf relative electrolyte leakage, malondialdehyde content, total superoxide dismutase activity, chlorophyll content and root activity. Compared with WT plants, the transgenic plants expressing PtPCS grew better in the Cd treatment and showed significantly higher Cd tolerance. Compared with WT plants, the transgenic lines accumulated higher concentrations of Cd (1.7 to 3.0-fold higher Cd concentration in roots; 1.24 to 2.28-fold higher Cd concentration in leaves). However, the transfer coefficient was lower in the transgenic lines than in wild type. We concluded that PtPCS encodes a functional PCS that may be involved in Cd tolerance and accumulation, but not in Cd transport.

By carrying out density functional theoretical calculations, we have performed a detailed mechanistic study of the Au(I)-catalyzed cycloisomerization of 1,6-enylnyl ester in a dry and wet dichloromethane solvent corresponding to hydrogenation and hydrolysis processes, respectively. The hydrogenation and hydrolysis mechanisms proposed in the previous literature starting from an enol ketal intermediate without the involvement of an Au(I) catalyst are found to involve high barriers and thus contradict the observed experimental findings. Alternatively, based on the theoretical calculations, a novel hydrogenation mechanism (i.e., Au-induced H-shift followed by enol intermediate self-promoted H-shift) and a hydrolysis mechanism (i.e., Au-stabilized H-shift/C-O binding with subsequent H2O-assisted H-shift) from an Au-enol ketal adduct corroborate the experimental observations. The calculated results indicate that under unchanged wet conditions, the formation of a hydrolysis product is not involved in the intermediacy of the hydrogenation product. However, if the initial dry environment is provided, a hydrogenation product will be afforded. And then it will relentlessly evolve into a hydrolysis product in the subsequent wet conditions. The present theoretical results not only rationalize the experimental observations well but provide new insight into the mechanisms of the significant water-mediated cycloisomerization reaction.

In this study, the adsorption behavior of carbon monoxide (CO) gas molecules on anionic M@Bn− (M = Co, Ir, Rh, Ru, Ta, Nb, n = 8–10) clusters has been systematically investigated by employing density functional theory (DFT). It was found that CO adsorption on boron clusters proceeds spontaneously and easily, accompanied with a dramatic structural deformation for the corresponding M@Bn− clusters. Large adsorption energies ranging from −22.82 to −27.38 kcal mol−1 have been observed for CO on boron clusters. The kinetic stabilities of the formed complexes have been verified by ab initio molecular dynamics. The IR spectra and adiabatic detachment energy of the M@Bn− clusters have been discussed before and after CO adsorption. In addition, the adsorption behavior of the other small gas molecules, such as CO2, N2, CH4, H2O, and O2, have also been explored. The potential applications of these wheel boron M@Bn− clusters in the detection of CO gas have been proposed for the first time.

Background Aging is a known risk factor of idiopathic pulmonary fibrosis (IPF). However, the pathogenic mechanisms underlying the effects of advanced aging remain largely unknown. Telomeric repeat-containing RNA (TERRA) represents a type of long noncoding RNA. In this study, the regulatory roles of TERRA on human telomeres and mitochondria and IPF epithelial injury model were identified. Methods Blood samples were collected from patients with IPF (n = 24) and matched control individuals (n = 24). The significance of clinical research on the TERRA expression correlated with pulmonary fibrosis was assessed. The expression levels of TERRA in vivo and in vitro were determined through quantitative real-time polymerase chain reaction analysis. Telomerase activity was observed using a fluorescent quantitative TRAP assay kit. The functions of telomeres, mitochondria, and associated genes were analyzed through RNA interference on TERRA. Results TERRA expression levels significantly increased in the peripheral blood mononuclear cells of IPF patients. The expression levels also exhibited a direct and significantly inverse correlation with the percentage of predicted force vital capacity, which is a physiological indicator of fibrogenesis during IPF progression. This finding was confirmed in the epithelial injury model of IPF in vitro. RNA interference on TERRA expression can ameliorate the functions of telomeres; mitochondria; associated genes; components associated with telomeres, such as telomerase reverse transcriptase, telomerase, and cell nuclear antigen, cyclin D1; and mitochondria-associated cyclin E genes, including the MMP and Bcl-2 family. The RNA interference on TERRA expression can also improve the functions of oxidative-stress-associated genes, such as reactive oxygen species, superoxide dismutase, and catalase, and apoptosis-related genes, such as cytochrome c, caspase-9, and caspase-3. Conclusions In this study, the regulation of TERRA expression on telomeres and mitochondria during IPF pathogenesis was identified for the first time. The results may provide valuable insights for the discovery of a novel biomarker or therapeutic approach for IPF treatment.

In this study, we developed a novel photoelectrochemical (PEC) sensor for the highly sensitive detection of erythromycin by functionalising graphene oxide (GO) with nickel tetra-amined phthalocyanine (NiTAPc) through covalent bonding, which resulted in the formation of NiTAPc-Gr. The fabricated sensor showed a higher PEC efficiency under blue light, exhibiting a peak wavelength of 456 nm, as compared to that of the monomer. Further, the NiTAPc-Gr/indium tin oxide (ITO) sensor exhibited a photocurrent that was 50-fold higher than that for a GO/ITO sensor under the same conditions. Under optimal conditions, the NiTAPc-Gr PEC sensor showed a linear response for erythromycin concentrations ranging from 0.40 to 120.00 μmol L-1, with the minimum limit for detection being 0.08 μmol L-1. Thus, the NiTAPc-Gr sensor exhibited superior performance and excellent PEC characteristics, high stability, and good reproducibility with respect to the sensing of erythromycin. Moreover, it is convenient to use, fast, small, and cheap to produce. Hence, it should find wide use in the analysis of erythromycin in real-world applications.

Herein, we present the design and multi-application of a bright and sensitive ratiometric fluorescent probe, PIPBA, for the imaging of formaldehyde (FA) in living systems., As a notorious toxin, formaldehyde (FA) poses an immense threat to human health. Aberrantly elevated FA levels lead to serious pathologies, including organ damage, neurodegeneration, and cancer. Unfortunately, current techniques limit FA imaging to general comparative studies, instead of a mechanistic exploration of its biological role, and this is presumably due to the lack of robust molecular tools for reporting FA in living systems. More importantly, despite being reductive, FA, however, can induce oxidative damage to organisms, thus providing a challenge to the mechanistic study of FA using fluorescence imaging. Herein, we presented the design and multi-application of a bright sensitive ratiometric fluorescent probe 1-(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenyl) but-3-en-1-amine (PIPBA). With a π-extended phenylphenanthroimidazole fluorophore and an allylamine group, PIPBA exhibited high quantum yield (φ = 0.62) in blue fluorescent emission and selective reactivity toward FA. When sensing FA, PIPBA transformed to PIBE, which is a product capable of releasing bright green fluorescence (φ = 0.51) with its enhanced intramolecular charge transfer (ICT). Transformation of PIPBA to PIBE contributed to 80 nm of red shift in emission wavelength and a highly sensitive ratiometric response (92.2-fold), as well as a quite low detection limit (0.84 μM). PIPBA was successfully applied to various living systems, realizing, for the first time, ratiometric quantification (in cells), in vivo imaging (zebrafish), and living tissue imaging (vivisectional mouse under anaesthetic) of endogenous FA that was spontaneously generated by biological systems. Furthermore, with the aid of PIPBA, we obtained visual evidence for the oxidative damage of FA in both HeLa cells and renal tissue of a living mouse. The results demonstrated that FA exerted indirect oxidative damage by interacting with free radicals, thus producing more oxidizing species, which eventually caused aggravated oxidative damage to the organism. The indirect oxidative damage due to FA could be alleviated by an exogenous or endogenous antioxidant. The excellent behaviors of PIPBA demonstrate that a chemical probe can detect endogenous FA in cells/tissue/vivo, promising to be an effective tool for further exploration of the biological mechanism of FA in living systems.

The cells control their pH change in a very accurate range. pH plays important roles in cell autophagy and apoptosis. Previous evidence implies that the internal milieu of a tumor is acidified. Although the acidification in cells is investigated, the biological effects from multiple stimulating factors under the complex intracellular environment have not been thoroughly elaborated yet. Currently, there are few pH probes that perform in a wide acidity range, and a probe that is capable of measuring a wide pH range needs to be developed. Herein, we report two new fluorescent probes (BHNBD and CM-BHNBD) for the detection of mitochondrial and intramucosal acidification. The two probes respond to pH via an H+-driven TICT (twist intramolecular charge transfer) mechanism, and they can linearly report pH within a wide pH range: 7.00–2.00 following ∼148-fold fluorescence increase. The two probes also possess excellent membrane permeability, good photostability, and negligible cytotoxicity. The probes are successfu...

The Pd-catalyzed cross-coupling of aryl iodide, benzoic anhydride and ethyl acrylate provided a useful alternative to synthesize alkenylated aryl ketones with good selectivity and functional-group tolerance. In this manuscript, density functional theory (DFT) calculations were performed to address the detailed reaction mechanism. Computational results support the experimentally proposed Pd(0)–Pd(II)–Pd(IV) catalytic cycle and further clarify that the rate-determining step is the oxidative addition of benzoic anhydride, the regioselectivity-determining step is the migratory insertion of ethyl acrylate and the following β-H elimination determines the stereoselectivity. The regioselectivity can be attributed to the steric and electronic effect of ethyl acrylate and the stereoselectivity can be explained by the steric repulsion between the toluene moiety and the CO2Et moiety. Furthermore, we found that norbornene not only acts as the removable scaffold in Catellani–Lautens-type reactions, but also plays the role of suppressing the competitive migratory insertion of ethyl acetate. Norbornene insertion and ethyl acetate insertion are found to have close free energy barriers, which shed light on the origin of using stoichiometric amounts of norbornene.

Homeostasis of ClO

N-Aryl tetrahydroisoquinolines were oxidised to dihydroisoquinolones through the relay catalysis of a binuclear paddle-wheel copper complex and a vitamin B1 analogue with oxygen as oxidant. Mechanistic studies revealed that the copper catalyst oxidises amines to the corresponding iminium salts, which are then oxygenated to lactam products by catalysis of the vitamin B1 analogue.