A highly reversible force-assisted Li - CO2 battery based on piezoelectric effect of Bi0.5Na0.5TiO3 nanorods.

The use of light-assisted cathode is regarded as an effective approach to reduce the overpotential of lithium carbon dioxide (Li - CO2) batteries. However, the inefficient electron-hole separation and the complex discharge-charge reactions hamper the efficiency of CO2 photocatalytic reaction in battery. Herein, a highly reversible force-assisted Li - CO2 battery has been established for the first time by employing a Bi0.5Na0.5TiO3 nanorods piezoelectric cathode. The high-energy electron and holes generated by the piezoelectric cathode with ultrasonic force can effectively enhance the carbon dioxide reduction reaction (CDRR) and carbon dioxide evolution reaction (CDER) kinetics, thereby reducing the overpotentials during the discharge-charge processes. Moreover, the morphology of the discharge product (Li2CO3) can be modified via the dense surface electrons of the piezoelectric cathode, resulting in the promoted decomposition kinetics of Li2CO3 in charging progress. Thus, the force-assisted Li - CO2 battery with the unique piezoelectric cathode can adjust the output and input energy by ultrasonic wave, and provides an ultra-low charging platform of 3.52 V, and exhibits excellent cycle stability (a charging platform of 3.42 V after 100 h cycles). The investigation of the force-assisted process described herein provides significant insights to solve overpotential in the Li - CO2 batteries system.

All-Solid-State Photo-Assisted Li-CO2 Battery Working at an Ultra-Wide Operation Temperature.

At present, photoassisted Li-air batteries are considered to be an effective approach to overcome the sluggish reaction kinetics of the Li-air batteries. And, the organic liquid electrolyte is generally adopted by the current conventional photoassisted Li-air batteries. However, the superior catalytic activity of photoassisted cathode would in turn fasten the degradation of the organic liquid electrolyte, leading to limited battery cycling life. Herein, we tame the above limitation of the traditional liquid electrolyte system for Li-CO2 batteries by constructing a photoassisted all-solid-state Li-CO2 battery with an integrated bilayer Au@TiO2/Li1.5Al0.5Ge1.5(PO4)3 (LAGP)/LAGP (ATLL) framework, which can essentially improve battery stability. Taking advantage of photoelectric and photothermal effects, the Au@TiO2/LAGP layer enables the acceleration of the slow kinetics of the carbon dioxide reduction reaction and evolution reaction processes. The LAGP layer could resolve the problem of liquid electrolyte decomposition under illumination. The integrated double-layer LAGP framework endows the direct transportation of heat and Li+ in the entire system. The photoassisted all-solid-state Li-CO2 battery achieves an ultralow polarization of 0.25 V with illumination, as well as a high round-trip efficiency of 92.4%. Even at an extremely low temperature of -73 °C, the battery can still deliver a small polarization of 0.6 V by converting solar energy into heat to achieve self-heating. This study is not limited to the Li-air batteries but can also be applied to other battery systems, constituting a significant step toward the practical application of all-solid-state photoassisted Li-air batteries.

Oxygen Vacancy-Mediated Growth of Amorphous Discharge Products toward an Ultrawide Band Light-Assisted Li-O2 Batteries.

Photoassisted electrochemical reaction is regarded as an effective approach to reduce the overpotential of lithium-oxygen (Li-O2 ) batteries. However, the achievement of both broadband absorption and long term battery cycling stability are still a formidable challenge. Herein, an oxygen vacancy-mediated fast kinetics for a photoassisted Li-O2 system is developed with a silver/bismuth molybdate (Ag/Bi2 MoO6 ) hybrid cathode. The cathode can offer both double advantages for light absorption covering UV to visible region and excellent electrochemical activity for O2 . Upon discharging, the photoexcited electrons from Ag nanoplate based on the localized surface plasmon resonance (LSPR) are injected into the oxygen vacancy in Bi2 MoO6 . The fast oxygen reaction kinetics generate the amorphous Li2 O2 , and the discharge plateau is improved to 3.05 V. Upon charging, the photoexcited holes are capable to decompose amorphous Li2 O2 promptly, yielding a very low charge plateau of 3.25 V. A first cycle round-trip efficiency is 93.8% and retention of 70% over 500 h, which is the longest cycle life ever reported in photoassisted Li-O2 batteries. This work offers a general and reliable strategy for boosting the electrochemical kinetics by tailoring the crystalline of Li2 O2 with wide-band light.

Magnetic and Optical Field Multi-Assisted Li-O2 Batteries with Ultrahigh Energy Efficiency and Cycle Stability.

The photoassisted lithium-oxygen (Li-O2 ) system has emerged as an important direction for future development by effectively reducing the large overpotential in Li-O2 batteries. However, the advancement is greatly hindered by the rapidly recombined photoexcited electrons and holes upon the discharging and charging processes. Herein, a breakthrough is made in overcoming these challenges by developing a new magnetic and optical field multi-assisted Li-O2 battery with 3D porous NiO nanosheets on the Ni foam (NiO/FNi) as a photoelectrode. Under illumination, the photogenerated electrons and holes of the NiO/FNi photoelectrode play a key role in reducing the overpotential during discharging and charging, respectively. By introducing the external magnetic field, the Lorentz force acts oppositely on the photogenerated electrons and holes, thereby suppressing the recombination of charge carriers. The magnetic and optical field multi-assisted Li-O2 battery achieves an ultralow charge potential of 2.73 V, a high energy efficiency of 96.7%, and good cycling stability. This external magnetic and optical field multi-assisted technology paves a new way of developing high-performance Li-O2 batteries and other energy storage systems.

A Renewable Light-Promoted Flexible Li-CO2 Battery with Ultrahigh Energy Efficiency of 97.9.

Directly converting and storing abundant solar energy in next-generation energy storage devices is of central importance to build a sustainable society. Herein, a new prototype of a light-promoted rechargeable and flexible Li-CO2 battery with a TiO2 /carbon cloth (CC) cathode is reported for the direct utilization of solar energy to promote the kinetics of the carbon dioxide reduction reaction and carbon dioxide evolution reaction (CO2 ER). Under illumination, photoelectrons are generated in the conduction band of TiO2 /CC, followed by the enhancing diffusion of electrons and lithium ions during the discharge process. The photoelectrons on the cathode surface can regulate the morphology of the discharge product Li2 CO3 , contributing to boosting the kinetics of the subsequent CO2 ER process. In the reverse charge process, photogenerated holes can favor the decomposition of Li2 CO3 , leading to a negative charge potential of 2.88 V without increased polarization over ≈60 h of cycling. Owing to an ultralow overpotential of 0.06 V between the discharge and charge process, an ultrahigh energy efficiency of 97.9% is attained under illumination. The introduction of a light-promoted flexible Li-CO2 battery can pave the way toward developing the use of solar energy to address the charging overpotential of conventional Li-CO2 batteries.

Driving Oxygen Electrochemistry in Lithium-Oxygen Battery by Local Surface Plasmon Resonance.

Although the lithium-oxygen (Li-O2) battery brings hope for the improvement of high-energy rechargeable batteries, the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics become the major stumbling block. Herein, the incorporation of a plasmonic silver cathode as an advanced strategy to promote ORR and OER kinetics due to strong local surface plasmon resonance (LSPR) is introduced. Chronoamperometry results revealed that the highly energetic electrons and holes excited by LSPR of silver nanostructure facilitated ORR and OER kinetics ascribe to the emission of hot carriers in femtosecond time scale. Furthermore, a relatively rare discharge voltage 3.1 V is obtained, correspondingly, the charge plateau also decline to 3.3 V, the energy efficiency of Li-O2 battery by a 23% increase in comparison with a commercial 5% Pt/C catalyst (discharge and charge plateau of 2.75 and 3.61 V). Additionally, the improvement in the efficient charge transfer manner result in a reversible spherical Li2O2 which further improve the ORR and OER kinetics. The LSPR strategy represents a critical step toward developing fast kinetics and high energy efficiency Li-O2 batteries.

Light/Electricity Energy Conversion and Storage for a Hierarchical Porous In2 S3 @CNT/SS Cathode towards a Flexible Li-CO2 Battery.

A photoinduced flexible Li-CO2 battery with well-designed, hierarchical porous, and free-standing In2 S3 @CNT/SS (ICS) as a bifunctional photoelectrode to accelerate both the CO2 reduction and evolution reactions (CDRR and CDER) is presented. The photoinduced Li-CO2 battery achieved a record-high discharge voltage of 3.14 V, surpassing the thermodynamic limit of 2.80 V, and an ultra-low charge voltage of 3.20 V, achieving a round trip efficiency of 98.1 %, which is the highest value ever reported (<80 %) so far. These excellent properties can be ascribed to the hierarchical porous and free-standing structure of ICS, as well as the key role of photogenerated electrons and holes during discharging and charging processes. A mechanism is proposed for pre-activating CO2 by reducing In3+ to In+ under light illumination. The mechanism of the bifunctional light-assisted process provides insight into photoinduced Li-CO2 batteries and contributes to resolving the major setbacks of the system.

[Research progress on effects of traditional Chinese medicines on proliferation, apoptosis and differentiation of bone marrow mesenchymal stem cells].

Bone marrow mesenchymal stem cells (BMSCs) are a kind of pluripotent stem cells derived from bone marrows, which can not only support hematopoiesis, but also have capabilities of multidifferentiation, high-proliferation and self-renewing. They have become one of hotspots in stem cell studies. Studies on in vitro intervention with BMSCs with TCMs have made remarkable progress in recent years. According to the findings, some traditional Chinese medicines can promote proliferation of BMSCs, some can inhibit the apoptosis of BMSCs, while others can induce BMSCs to differentiate into multiple cell types, such as osteoblast. Furthermore, some studies also involved relevant action mechanisms. The authors summarized the advance in relevant studies by reference to relevant literatures of this field.

A piperidine alkaloid and limonoids from Arisaema decipiens, a traditional antitumor herb used by the Dong people.

A new piperidine alkaloid and three known tetranortriterpenoids were isolated from the methanol extracts of the rhizomes of Arisaema decipiens Schott (Araceae) and their chemical structures were identified as (-)-(2R*,3S*,6S*)-N,2-dimethyl-3-hydroxy-6-(9-phenylnonyl) piperidine (1), 6-deacetylnimbin (2), 28-deoxonimbolide (3) and nimbin (4). The N-methylated derivative (1a) of 1 was synthesized. Compound 1 exhibited weak inhibitory activity against the MCF-7 cell line, while compound 1a showed potential inhibitory activity against the MCF-7 cell line with an IC50 value of 4.6 µM and weak inhibitory activity against K562 and SK-OV-3 cells. This plant in genus Arisaema is firstly reported as the source of limonoids that are considered a natural antitumor herbal medicine.

Hepatocyte growth factor protects human embryonic stem cell derived-neural progenitors from hydrogen peroxide-induced apoptosis.

Promoting human embryonic stem cell (hESC)-derived-neural progenitor survival in the pro-apoptotic niche is pivotal for stem cell replacement therapy. The present study was designed to investigate the protective effect of hepatocyte growth factor (HGF) on hESC-derived neural progenitor injured by hydrogen peroxide (H(2)O(2)) exposure. Treatment of hESC-derived neural progenitor cells with HGF prior to H(2)O(2) exposure conferred protective effect against oxidative stress-induced apoptosis. HGF treatment increased both phosphoinositide 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase1/2 (ERK1/2) phosphorylation. However, selective inhibition of each pathway supported that the activation of PI3K/AKT, but not ERK1/2, provides survival advantage to the neural progenitor cells. Further investigation indicated that HGF pretreatment could attenuate the decrease of the expression of Bcl-2 protein induced by H(2)O(2), whereas the level of Bax was not affected. Additionally, we observed that H(2)O(2)-induced decrease of mitochondrial transmembrane potential, release of cytochrome c and increase of caspase-3 activation were alleviated by HGF pretreatment. These effects of HGF could be reversed by inhibition of the PI3K/Akt and ERKs pathways, indicating PI3K/Akt and ERKs signaling might be involved in HGF-mediated regulation of mitochondrial apoptotic pathway mediated by H(2)O(2). The neuroprotective effect of HGF might potentially be useful in stem cell-based therapies for neurodegenerative disorders.

Optimization of physiological xenofree molecularly defined media and matrices to maintain human embryonic stem cell pluripotency.

We describe in this chapter the development of a xenofree molecularly defined medium, SBX, associated with xenofree matrices, to maintain human embryonic stem cell (hESC) pluripotency as determined by phenotypic, functional and TLDA studies. This simple, inexpensive, and more physiological culture condition has been chosen because (1) it is xenofree and molecularly defined; it is devoid of albumin, which is a carrier of undefined molecules; (2) it maintains pluripotency, but very significantly reduces differentiation gene expression during hESC self-renewal, as compared to the widely used culture conditions tested so far; and (3) it can be further improved by replacing high concentrations of expensive additives by physiological concentrations of new factors. Xenofree molecularly defined media and matrices represent valuable tools for elucidating still unknown functions of numerous embryonic genes using more physiological culture conditions. These genes encode potential new factors controlling hESC self-renewal and pluripotency.

Sarcocystis tupaia, sp. nov., a new parasite species employing treeshrews (Tupaiidae, Tupaia belangeri chinensis) as natural intermediate hosts.

The range of vertebrates that serve as intermediate hosts for parasites in the genus Sarcocystis remains incompletely defined. Here, we provide the first report of infections in treeshrews, describe the morphology of encysted parasites using light and transmission electron microscopy, and place this agent within a phylogenetic context by sequencing and comparing its 18S ribosomal DNA to that of related parasites. Muscle infections were diagnosed in four of 45 wild treeshrews captured in the vicinity of Kunming, Yunnan Province, Mainland China. Thread-like cysts (10.773+/-2.411mm in length, 0.106+/-0.009mm in width) had walls (0.538-0.746microm thick) that lacked perpendicular protrusions. The interior of the cyst was packed full with cyst merozoites, the shape of which was typical of Sarcocystis. The primary cyst wall consisted of a thin membrane supported by osmiophilic material, 31-60nm in thickness. The ground substance was about 105-526nm thickness. Cysts conformed to typical of 'type 1' sarcocysts. Freshly examined and frozen specimens did not differ in their cyst wall structure, however, the appearance of bradyzoites did differ: the conoid, rhoptries and micronemes were all visible in fresh bradyzoites; in stored bradyzoites, by contrast, the rhoptries appeared smaller, and although the conoid was visible, the micronemes were not. 18S rRNA gene was distinct from any previously reported sequence in GenBank. Their genetic and morphological uniformity suggest that these parasites, derived from treeshrews, represent a single biological species, Sarcocystis tupaia, sp. nov.

[bFGF-stimulated MEF-conditioned medium is capable of maintaining human embryonic stem cells].

4 ng/ml bFGF is indispensable for hESC cultured on mouse embryonic fibroblasts (MEF), withdrawal of bFGF drives the hESC to differentiate. In order to exploit effect of bFGF on MEF, we collected a series of MEF conditioned medium (bFGF-MCM) by co-culturing MEF with increasing bFGF concentrations: 0.03, 0.1, 0.3, 1 and 4 ng/ml. The primitivity of hESC cultured in bFGF-MCM was estimated by morphology and alkaline phosphatase staining. Compared with the control medium (medium conditioned without bFGF: MCM), percentage of undifferentiated colony was increased from 23% to 29%, 44%, 74%, 77% and 78%, respectively. However, percentage of undifferentiated colony in the blank medium (medium conditioned with bFGF but without MEF: bFGF-SR) was from 13% to 31%. This indicated that low concentration of bFGF acted on MEF and stimulated MEF producing effective conditioned medium for maintaining hESC. To identify active elements in the effective conditioned medium can help to understand mechanisms of hESC self-renewal.

Sesquiterpenoids from Pilea cavaleriei subsp. crenata.

Three new humulane-type sesquiterpenes, 8-O-(p-coumaroyl)-5beta-hydroperoxy-1(10)E,4(15)-humuladien-8alpha-ol (1), 8-O-(3-nitro-p-coumaroyl)-1(10)E,4(15)-humuladien-5beta,8alpha-diol (2) and 8-O-(p-coumaroyl)-1(10)E,4(5)E-humuladien-8-ol (3), and a new copaborneol derivative, 1-O-p-coumaroyl-copaborneol (4), have been isolated from the methanol extract of Pileacavaleriei Lévl. subsp. crenata C. J. Chen. Their structures were elucidated using spectroscopic methods. Cytotoxic and antimicrobial activities of the isolated compounds were evaluated.

Use of xenofree matrices and molecularly-defined media to control human embryonic stem cell pluripotency: effect of low physiological TGF-beta concentrations.

To monitor human embryonic stem cell (hESC) self-renewal without differentiation, we used quantitative RT-PCR to study a selection of hESC genes, including markers for self-renewal, commitment/differentiation, and members of the TGF-beta superfamily and DAN gene family. Indeed, low commitment/differentiation gene expression, together with a significant self-renewal gene expres sion, provides a better pluripotency index than self-renewal genes alone. We demonstrate that matrices derived from human mesenchymal stem cells (hMSCs) can advantageously replace murine embryonic fibroblasts (MEF) or hMSC feeders. Moreover, a xenofree molecularly-defined SBX medium, containing a synthetic lipid carrier instead of albumin, can replace SR medium. The number of selected differentiation genes expressed by hESCs in these culture conditions was significantly lower than those expressed on MEF feeders in SR medium. In SBX, the positive effect of a non-physiological concentration of activin A (10-30 ng/mL) to reduce differentiation during self-renewal could also be obtained by physiological concentrations of TGF-beta(100-300 pg/mL). In contrast, these TGF-beta concentrations added to activin favored differentiation as previously observed with TGF-beta concentrations of 1 ng/mL or more. Compared to SR-containing medium, SBX medium promoted down-regulation of CER1 and LEFTIES and up-regulation of GREM1. Thus these genes better control self-renewal and pluripotency and prevent differentiation. A strategy is proposed to analyze, in more physiological, xenofree, molecularly-defined media and matrices, the numerous genes with still unknown functions controlling hESCs or human-induced pluripotent stem cells (iPS).

Cytotoxic ent-kauranoids from the medicinal plant Isodon xerophilus.

Bioassay-directed fractionation of the leaves of the medicinal plant Isodon xerophilus led to the isolation of a series of potential antitumor molecules. Thirteen new (1-13) and 23 (14-36) known diterpenoids were isolated and identified, representing ent-kauranoids of several structural types. The structures of 1-13 were determined by means of spectroscopic studies. The absolute configurations of the new compounds were clarified by CD spectroscopic studies or were postulated on biogenetic grounds. All compounds obtained were evaluated for their cytotoxic activity against the K562, MKN45, and HepG2 cell lines. Compounds 1, 2, 11, 16-19, 23, 26-28, 30, and 32 demonstrated significant cytotoxic activity for one or more cell lines.

Isolation of two bioactive ent-kauranoids from the leaves of Isodon xerophilus.

Isodon xerophilus has been used as a herbal cold tea for the prevention and treatment of sore throat and inflammation in southernwestern China. A phytochemical study on the ethyl acetate (EtOAc) soluble fraction of I. xerophilus leaves led to the isolation of two new ent-kauranoids, xerophinoids A (1) and B (2), together with 14 known diterpenoids. The structures of xerophinoids A (1) and B (2) were illustrated using spectroscopic methods including 1D and 2D NMR analyses. To study their biological activities, the effects of xerophinoids A (1) and B (2) on nitrite production, tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta were examined. In addition, xerophinoids A (1) and B (2) also exhibited potent cytotoxicity against several human tumor cell lines (IC50 < 11 microM), but they had no toxicity on human T-lymphocyte (C8166).

[Synthesis, structure characterization and anti-tumor activity of lanthanide complex Ln[ (Phen)2 (5-Fu)3 (NO3) (NO3 )2].

AIM: To study the biochemistry of lanthanides, the cooperative action of inorganic and organic anti-tumor drugs. METHODS: A series of rare earth complexes were synthesized with Ln(NO3) 6H2O, Phen and 5-Fu. Their anti-tumor activity was measured by the improved MTT, SRB methods. RESULTS: The formula of complex Ln[(Phen)2(5-Fu)3(NO3)](NO3)2(Ln = Y, La, Ce, Sm, Gd, Dy, Er; Phen = 1, 10-phenanthroline; 5-Fu = fluorouracil) was characterized by elemental analyses, molar conductivity, IR, TGA, and 13C NMR spectra. The preliminary biological activity studies indicated that Lanthanide complex has strong anti-tumor activity in vitro. CONCLUSION: The complex might have anti-tumor cooperation action.

Ent-kauranoids from Isodon rubescens var. taihangensis.

Two new compounds, rubescensins Q and R (1 and 2), and a new acetonide derivative (3) of lasiodonin, together with thirteen known analogues, oridonin (4), ponicidin (5), wikstroemioidin B (6), lasiodonin (7), lasiokaurin (8), enmenol (9), 1-O-beta-D-glucopyranosyl-enmenol (10), trichokaurin (11), the acetonide of maoyecrystal F (12), rabdoternins A-D (13-16), have been isolated from Isodon rubescens var. taihangensis. The structures of the new compounds were elucidated on the basis of spectroscopic methods, especially the 2D NMR spectral analysis. Compound 3 exhibited cytotoxicity against K562, Bcap37, CA, CNE, BIU87, BGC823, and HeLa cell lines.

Maoecrystal V, cytotoxic diterpenoid with a novel C19 skeleton from Isodon eriocalyx (Dunn.) hara.

Maoecrystal V (1), a novel C(19) diterpenoid possessing a unique 6,7-seco-6-nor-15(8-->9)-abeo-5,8-epoxy-ent-kaurane skeleton, was isolated from the leaves of a Chinese medicinal herb, Isodon eriocalyx. Its structure was determined by comprehensive NMR and MS spectroscopic analysis and confirmed by single-crystal X-ray diffraction study. Compound 1 showed remarkable inhibitory activity toward HeLa cells with IC(50) = 0.02 microg/mL (cis-platin: IC(50) = 0.99 microg/mL).