Regioselective Synthesis, Crystallographic Characterization, and Electrochemical Properties of Pyrazole- and Pyrrole-Ring-Fused Derivatives of Y2 @C3v (8)-C82.

Chemical modification of endohedral metallofullerenes (EMFs) is an efficient strategy to realize their ultimate applications in many fields. Herein, we report the highly regioselective and quantitative mono-formation of pyrazole- and pyrrole-ring-fused derivatives of the prototypical di-EMF Y2 @C3v (8)-C82 , that is, Y2 @C3v (8)-C82 (C13 N2 H10 ) and Y2 @C3v (8)-C82 (C9 NH11 ), from the respective 1,3-dipolar reactions with either diphenylnitrilimine or N-benzylazomethine ylide, without the formation of any bis- or multi-adducts. Crystallographic results unambiguously reveal that only one [6,6]-bond out of the twenty-five different types of nonequivalent C-C bonds of Y2 @C3v (8)-C82 is involved in the 1,3-dipolar reactions. Our theoretical results rationalize that the remarkably high regioselectivity and the quantitative formation of mono-adducts are direct results from the anisotropic distribution of π-electron density on the C3v (8)-C82 cage and the local strain of the cage carbon atoms as well. Interestingly, electrochemical and theoretical studies demonstrate that the reversibility of the redox processes, in particular the reversibility of the reductive processes of Y2 @C3v (8)-C82 , has been markedly altered upon exohedral functionalization, but the oxidative process was less influenced, indicating that the oxidation is mainly influenced by the internal Y2 cluster, whereas the reduction is primarily associated with the fullerene cage. The pyrazole and pyrrole-fused derivatives may find potential applications as organic photovoltaic materials and biological reagents.

Oxygen-Delivery Materials: Synthesis of an Open-Cage Fullerene Derivative Suitable for Encapsulation of H2 O2 and O2.

An open-cage [60]fullerene was prepared through a multiple-step sequence based on peroxide-mediated cage-opening reactions. Key steps include repeated C60 -sensitized singlet-oxygen oxidation of electron-rich amino enol double bonds to form two lactone and two lactam moieties on the rim of the orifice. Single-crystal X-ray analysis shows that the 22-membered orifice has an ellipsoid shape with the major axis at 6.7 Šand the minor axis at 3.5 Å. Encapsulation of H2 O2 was observed under atmospheric pressure at room temperature. Oxygen is also effectively trapped during the process.

Lu2@C2n (2n = 82, 84, 86): Crystallographic Evidence of Direct Lu-Lu Bonding between Two Divalent Lutetium Ions Inside Fullerene Cages.

Although most of the M2C2n-type metallofullerenes (EMFs) tend to form carbide cluster EMFs, we report herein that Lu-containing EMFs Lu2C2n (2n = 82, 84, 86) are actually dimetallofullerenes (di-EMFs), namely, Lu2@Cs(6)-C82, Lu2@C3v(8)-C82, Lu2@D2d(23)-C84, and Lu2@C2v(9)-C86. Unambiguous X-ray results demonstrate the formation of a Lu-Lu single bond between two lutetium ions which transfers four electrons in total to the fullerene cages, thus resulting in a formal divalent state for each Lu ion. Population analysis indicates that each Lu atom formally donates a 5d electron and a 6s electron to the cage with the remaining 6s electron shared with the other Lu atom to form a Lu-Lu single bond so that only four electrons are transferred to the fullerene cages with the formal divalent valence for each lutetium ion. Accordingly, we confirmed both experimentally and theoretically that the dominating formation of di-EMFs is thermodynamically very favorable for Lu2C2n isomers.

Regioselective Synthesis and Crystallographic Characterization of Isoxazoline-Ring-Fused Derivatives of Sc3N@Ih-C80 and C60.

Highly regioselective 1,3-dipolar cycloaddition of 3,5-dichloro-2,4,6-trimethoxybenzonitrile oxide (1) to Sc3N@Ih-C80 or C60 affords the corresponding isoxazoline-ring-fused derivatives Sc3N@Ih-C80(C10H9O4NCl2) (2a) and C60(C10H9O4NCl2) (2b). 2a represents the first example of an endohedral metallofullerene derivative with an isoxazoline ring. Crystallographic and NMR spectroscopic studies reveal a [5,6]-bond addition pattern in 2a but a [6,6]-bond addition manner in 2b.

Induction of Autophagy interferes the tachyzoite to bradyzoite transformation of Toxoplasma gondii.

Autophagy process in Toxoplasma gondii plays a vital role in regulating parasite survival or death. Thus, once having an understanding of certain effects of autophagy on the transformation of tachyzoite to bradyzoite this will allow us to elucidate the function of autophagy during parasite development. Herein, we used three TgAtg proteins involved in Atg8 conjugation system, TgAtg3, TgAtg7 and TgAtg8 to evaluate the autophagy level in tachyzoite and bradyzoite of Toxoplasma in vitro based on Pru TgAtg7-HA transgenic strains. We showed that both TgAtg3 and TgAtg8 were expressed at a significantly lower level in bradyzoites than in tachyzoites. Importantly, the number of parasites containing fluorescence-labelled TgAtg8 puncta was significantly reduced in bradyzoites than in tachyzoites, suggesting that autophagy is downregulated in Toxoplasma bradyzoite in vitro. Moreover, after treatment with drugs, bradyzoite-specific gene BAG1 levels decreased significantly in rapamycin-treated bradyzoites and increased significantly in 3-MA-treated bradyzoites in comparison with control bradyzoites, indicating that Toxoplasma autophagy is involved in the transformation of tachyzoite to bradyzoite in vitro. Together, it is suggested that autophagy may serve as a potential strategy to regulate the transformation.

Isolation and Crystallographic Characterization of the Labile Isomer of Y@C82 Cocrystallized with Ni(OEP): Unprecedented Dimerization of Pristine Metallofullerenes.

Although the major isomers of M@C82 (namely M@C2v (9)-C82 , where M is a trivalent rare-earth metal) have been intensively investigated, the lability of the minor isomers has meant that they have been little studied. Herein, the first isolation and crystallographic characterization of the minor Y@C82 isomer, unambiguously assigned as Y@Cs (6)-C82 by cocrystallization with Ni(octaethylporphyrin), is reported. Unexpectedly, a regioselective dimerization is observed in the crystalline state of Y@Cs (6)-C82 . In sharp contrast, no dimerization occurs for the major isomer Y@C2v (9)-C82 under the same conditions, indicating a cage-symmetry-induced dimerization process. Further experimental and theoretical results disclose that the regioselective dimer formation is a consequence of the localization of high spin density on a special cage-carbon atom of Y@Cs (6)-C82 which is caused by the steady displacement of the Y atom inside the Cs (6)-C82 cage.

Crystallographic Evidence for Direct Metal-Metal Bonding in a Stable Open-Shell La2 @Ih -C80 Derivative.

Endohedral metallofullerenes (EMFs) have novel structures and properties that are closely associated with the internal metallic species. Benzyl radical additions have been previously shown to form closed-shell adducts by attaching an odd number of addends to open-shell EMFs (such as Sc3 C2 @Ih -C80 ) whereas an even number of groups are added to closed-shell EMFs (for example Sc3 N@Ih -C80 ). Herein we report that benzyl radical addition to the closed-shell La2 @Ih -C80 forms a stable, open-shell monoadduct instead of the anticipated closed-shell bisadduct. Single-crystal X-ray diffraction results show the formation of a stable radical species. In this species, the La-La distance is comparable to the theoretical value of a La-La covalent bond and is shorter than reported values for other La2 @Ih -C80 derivatives, providing unambiguous evidence for the formation of direct La-La bond.

Macrolide-resistant Mycoplasma pneumoniae in adults in Zhejiang, China.

Mycoplasma pneumoniae is a major pathogen causing community-acquired pneumoniae (CAP), which is generally treated with macrolides. In recent years, however, although macrolide-resistant M. pneumoniae has been reported frequently, particularly in China, very little is known about the prevalence of macrolide-resistant M. pneumoniae infection in adults. In this study, we survey the macrolide-resistant M. pneumoniae in adults in Zhejiang province and characterize the mechanisms of resistance to macrolide. Six hundred fifty throat swab samples were collected from adult patients with CAP from January 2012 to August 2014. These samples were assayed by nested PCR and then cultivated for M. pneumoniae. All isolates were sequenced to determine the mutation in domain V of the 23S rRNA gene. The activities of 10 antibiotics against macrolide-resistant M. pneumoniae isolates were also investigated in vitro. Moreover, restriction fragment length polymorphism (RFLP) analysis of the amplified P1 gene was used to type 50 resistant strains. One hundred percent (71/71) of M. pneumoniae strains isolated from adults with CAP were resistant to erythromycin (MIC=128 to >256 µg/ml), clarithromycin (MIC=128 to >256 µg/ml), and azithromycin (MIC=32 to >64 µg/ml). Furthermore, all macrolide-resistant M. pneumoniae strains identified had an A2063G mutation in domain V of the 23S rRNA gene. Forty-six resistant strains (92.0%) were classified into type I strain on the basis of P1 gene PCR-RFLP analysis. According to these findings, it is suggested that macrolide-resistant M. pneumoniae infection is very prevalence among adults in Zhejiang province. Thus, there is necessary to perform the epidemiological monitoring of macrolide-resistant M. pneumoniae in the future.

[Analysis and identification of peptide epitope of the fifth stage larvae of Angiostrongylus cantonensis].

OBJECTIVE: To identify the specific antigens of the fifth stage larvae (larvae V) of Angiostrongylus cantonensis in soluble proteins. METHODS: The techniques of two-dimensional electrophoresis (2-DE) and immunoblot were employed to analyze the soluble components of larvae V antigens. The resulting protein spots were identified by mass spectrometry and the specific antigen and immunogenic peptide segment profiles determined.Larvae V was identified by immunoblot of peptide immune murine sera. RESULTS: Immunoblot of 2-DE showed that there were 8 specific antigen spots in females and 4 in males of larvae V. The 12 protein spots had a pH range of 5-7 and a molecular weight of 24-40 kD. Among 12 spot, actin-1 and galectin-1 were identified successfully. And a peptide (NH2-KNGDIALHFNPRFDEK) was predicted as epitope and synthesized. The binding capacity of murine immune sera could identify the 32 000 of larvae V. CONCLUSIONS: Galectin and actin are common antigens of female and male larvae V of A.cantonensis. And a peptide from galectin-1 may become a potential target for immunologic diagnosis and immunological mediator.

[Cloning and expression of Toxoplasma gondii autophagy-related protein 3 gene and preparation of its polyclonal antibody].

OBJECTIVE: To clone and express autophagy-related protein 3 (TgAtg3) gene of Toxoplasma gondii, and obtain the specific polyclonal antibody against TgAtg3. METHODS: TgAtg3 cDNA was inserted into prokaryotic expression vector pET28a. After identification, the constructed plasmid pET28a-TgAtg3 was transformed into E. coli Rosetta cells, and induced by special induction medium for expression of the protein. The recombinant protein was purified via Ni-NTA affinity chromatography. Western blotting assay was performed with anti-His tag mouse monoclonal antibody as the primary antibody. Rabbits were immunized with 125 µg purified TgAtg recombinant protein. Each rabbit received 4 immunizations at 2-week intervals with the same dose of antigen. The specific anti-TgAtg3 polyclonal antibody was obtained, and analyzed by Western blotting and indirect immunofluorescence assay (IFA). RESULTS: pET28a-TgAtg3 plasmid was identified by restriction enzyme digestion, PCR amplification and sequencing. SDS-PAGE and Western blotting analysis showed that the recombinant TgAtg3 protein (about Mr 44,000) was expressed in E. coli Rosetta cells. TgAtg3 protein from tachyzoite lysates was recognized by the specific anti-TgAtg3 polyclonal antibody. IFA assay determined that the specific polyclonal antibody bound to TgAtg3 protein from the cytoplasm of tachyzoites. CONCLUSION: The obtained soluble polyclonal antibody against TgAtg3 can specifically react to the endogenous TgAtg3 protein.

Ultrahigh Capacity from Complexation-Enabled Aluminum-Ion Batteries with C70 as the Cathode.

Restricted by the available energy storage modes, currently rechargeable aluminum-ion batteries (RABs) can only provide a very limited experimental capacity, regardless of the very high gravimetric capacity of Al (2980 mAh g-1 ). Here, a novel complexation mechanism is reported for energy storage in RABs by utilizing 0D fullerene C70 as the cathode. This mechanism enables remarkable discharge voltage (≈1.65 V) and especially a record-high reversible specific capacity (750 mAh g-1 at 200 mA g-1 ) of RABs. By means of in situ Raman monitoring, mass spectrometry, and density functional theory (DFT) calculations, it is found that this elevated capacity is attributed to the direct complexation of one C70 molecule with 23.5 (super)halogen moieties (superhalogen AlCl4 and/or halogen Cl) in average, forming (super)halogenated C70 ·(AlCl4 )m Cln-m complexes. Upon discharging, decomplexation of C70 ·(AlCl4 )m Cln-m releases AlCl4 - /Cl- ions while preserving the intact fullerene cage. This work provides a new route to realize high-capacity and long-life batteries following the complexation mechanism.

Preparation, Structures, Photoluminescence and Semiconductive Properties of Two Novel Lanthanide Mercury Materials with a 3-D Framework Structure.

Two novel lanthanide mercury materials, [Gd(IA)3(H3O)2Hg3Br6]n·2nCl (1) and [La(IA)3(H3O)2Hg3Br6]n·2nCl (2) (IA = isonicotinic anion), have been prepared under solvothermal conditions and characterized by single-crystal X-ray diffraction techniques. They are isomorphic and characterized by a three-dimensional (3-D) framework structure. The lanthanide ions are bound by eight oxygen atoms to exhibit a square antiprismatic geometry. The solid-state photoluminescence experiment discovers that compound 1 shows a strong emission in the red region. Compound 1 possesses CIE (Commission Internationale de I'Éclairage) chromaticity coordinates of 0.7347 and 0.2653. Its CCT (correlated color temperature) is 6514 K. Compound 2 displays yellow photoluminescence and it has CIE chromaticity coordinates of 0.4411 and 0.5151. The CCT of compound 2 is 3633 K. Solid-state UV/Vis diffuse reflectance spectra revealed that their semiconductor band gaps are 2.16 eV and 2.85 eV, respectively.

Stabilizing a non-IPR C2(13333)-C74 cage with Lu2C2/Lu2O: the importance of encaged non-metallic elements.

A difference in encaged non-metallic element (i.e., C2versus O) leads to a clear change of intramolecular interactions and shifts in redox potentials of Lu2C2@C2(13333)-C74 and Lu2O@C2(13333)-C74, as a result of their distinct molecular orbital energy levels. Different from these two endoherals whose HOMOs are located on the cage, experimentally absent Lu2@C2(13333)-C74 possesses a HOMO predominantly delocalized on the internal Lu-Lu bond, accompanied by a much smaller HOMO-LUMO gap, suggesting that the presence of a non-metallic unit broadens the electrochemical gaps and consequently improves the kinetic stability. These findings shed light on the role of non-metallic moieties in clusterfullerenes, providing valuable insights into the stability and properties of metallofullerenes.

A hard molecular nanomagnet from confined paramagnetic 3d-4f spins inside a fullerene cage.

Reducing inter-spin distance can enhance magnetic interactions and allow for the realization of outstanding magnetic properties. However, achieving reduced distances is technically challenging. Here, we construct a 3d-4f metal cluster (Dy2VN) inside a C80 cage, affording a heretofore unseen metallofullerene containing both paramagnetic 3d and 4f metal ions. The significantly suppressed 3d-4f (Dy-V) distances, due to the unique cage confinement effect, were observed by crystallographic and theoretical analysis of Dy2VN@Ih(7)-C80. These reduced distances result in an enhanced magnetic coupling (Jtotal, Dy-V = 53.30 cm-1; Jtotal, Dy-Dy = -6.25 cm-1), leading to a high magnetic blocking temperature compared to reported 3d-4f single-molecule magnets and strong coercive field of 2.73 Tesla. Our work presents a new class of single-molecule magnets with both paramagnetic 3d and 4f metals confined in a fullerene cage, offering superior and tunable magnetic properties due to the unique cage confinement effect and the diverse composition of the entrapped magnetic core.

Differential proteomics analysis of female and male adults of Angiostrongylus cantonensis.

In this study, we identified the differentially expressed proteins of female and male adults of Angiostrongylus cantonensis through differential proteomics. We extracted and purified total proteins from male and female adults, separated proteins by two-dimensional difference gel electrophoresis (2D-DIGE) in pH 4-7, analyzed the gel images by DeCyder 7.0 software, and sacrificed the infected rats to count the number of male and female adults. It was found 28 protein spots that were differentially expressed; seven protein spots were then identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Five proteins were up-regulated and two proteins down-regulated in male adults compared with female adults. Three of the five up-regulated proteins with known functions ascribed to them were identified as galectin-1, proteasome alpha subunit and peroxiredoxin. The two down-regulated proteins were identified as indoleamine dioxygenase like-myoglobin and galectin. Furthermore, the female was significantly greater than male adults (P<0.01) in the rats. The findings demonstrate the differences in protein expression profiles and the ability to survive in the final host between female and male adults of A. cantonensis, and may provide a theoretical basis to study their developmental biology further.

Urine sample used for detection of toxoplasma gondii infection by loop-mediated isothermal amplification (LAMP).

In this study, a loop-mediated isothermal amplification (LAMP) assay was established to detect Toxoplasma gondii DNA in mice infected with T. gondii PRU strain. This LAMP assay was based on the sequence of highly repetitive B1 gene. The detection limit of T. gondii LAMP assay was 1 pg of T. gondii DNA, which was evaluated using 10-fold serially diluted DNA of cultured parasites. The LAMP assay was also highly specific for T. gondii and able to detect T. gondii DNA in urine of mice treated with dexamethasone at 90 day post infection (p.i.), although this assay could not detect the DNA in mice urine 2-6 days p.i. These results demonstrated that LAMP is effective for evaluation of therapy effectiveness for T. gondii infection. The established LAMP assay may represent a useful and practical tool for the routine diagnosis and therapeutic evaluation of human toxoplasmosis.

Finite element simulation and optimization of mechanical performance of the magnesium-alloy biliary stent.

A biliary stent is used to expand the bile duct during interventional treatment of biliary stricture. To reduce the complications after stent implantation, it is necessary to understand and improve the comprehensive performance of magnesium alloy biliary stents. In this study, at first, the mechanical performance of magnesium alloy biliary stent in bile ducts with different ellipticitiesis studied, and the influence of the ellipticity of bile duct on the interaction of the stent-bile duct coupling system is better understood. Proposed results show the increment of ellipticity of the bile duct will increase the difficulty of expanding the stent. Second, to improve the mechanical performance and degradation performance of the stent simultaneously, an optimal design method based on a zero-order algorithm is used to reduce the maximum equivalent stress on the stent effectively, to make the stress distribution more uniform, and to expand the bile duct of the lesion more effectively and uniformly. The results of this analysis and optimization are useful to predict the clinical effect of stents and to design and optimize stents for both bile duct and other non-vascular.

[Application of double antibody sandwich ELISA for detection of nucleoside triphosphate hydrolase-II protein of Toxoplasma gondii].

OBJECTIVE: To establish a double antibody sandwich ELISA method for detection of nucleoside triphosphate hydrolase-II (NTPase-II) protein of Toxoplasma gondii. METHODS: BALB/c mice were immunized with recombinant NTPase-II (rTgNTPase-II) protein of T. gondii. The hybridomas that secreted high titer of monoclonal antibodies (mAbs) with high specificity were screened and used to establish the double antibody sandwich ELISA for the detection of rTgNTPase-II. In order to evaluate the sensitivity of the method, the concentration of whole-tachyzoite lysate and rTgNTPase-II was detected, respectively. Serum samples from patients with malaria (7 cases), schistosomiasis (12 cases), paragonimiasis (14 cases) and cysticercosis (10 cases) were examined by the same method. RESULTS: Two hybridoma cell lines, MNTI and MNT2, were developed for secreting mAbs against rTgNTPase-II. Western blotting analysis showed that the two mAbs specifically recognized rTgNTPase-II and whole-tachyzoite lysate. The MNT1 was used as coating antibody, and HRP-labeled MNT2 as secondary antibody. The double antibody sandwich ELISA detecting rTgNTPase-II was developed with a minimum concentration of 6 microg/ml for whole-tachyzoite lysate and 1.5 microg/ml for rTgNTPase-II. An overall specificity of 100% was determined. CONCLUSION: The double antibody sandwich ELISA based on MNT1 as coating antibody and MNT2 as secondary antibody has a high specificity.

The degradable performance of bile-duct stent based on a continuum damage model: A finite element analysis.

Biomedical magnesium alloy stents have become a hot bed of research focus in interventional therapy for nonvascular diseases. In this study, a numerical model for a balloon-expandable bile duct stent made of magnesium alloy with laser sculpture is developed to predict the effects of the degradation of the stent on the biomechanical behavior in the stent-bile duct coupling system. Based on a continuum damage model, the degradable model of the stent is built to understand its performance in an idealized bile duct as it is subject to corrosion over time. The degradation model developed in this study addresses the uniform corrosion and pitting corrosion. By means of the secondary development function of commercial numerical software ANSYS, the finite element analysis procedures were written to control the degradation process based on the technology of element "birth and death," and it is shown how the three-dimensional model and approach give the possibility of analyzing for the degradation mechanism of a magnesium alloy stent in the bile duct or other nonvascular cavities.

Regioselective Radical Reaction of Monometallofullerene Y@C2v(9)-C82 With N-arylbenzamidine Mediated by Silver Carbonate.

A novel radical reaction of monometallofullerene Y@C2v(9)-C82 with N-arylbezamidine (1) is successfully conducted through catalysis with silver carbonate. The high-performance liquid chromatographic and mass spectrum results demonstrate that the reaction is highly regioselective to afford only one monoadduct (2) with an imidazoline group added on C82 cage, and computations through density functional theory reveal the addition group is attached to a specific [5, 6]-bond (C20-C76) near the Y atom. Furthermore, the analysis of prymidalization angle of the carbon atoms demonstrates the geometry of carbon cage is in favor of the regioselective formation of isomer (20, 76).