Publications by authors named "Chunhua Han"

65 Publications

Acceptance of a COVID-19 vaccine and associated factors among pregnant women in China: a multi-center cross-sectional study based on health belief model.

Hum Vaccin Immunother 2021 May 14:1-10. Epub 2021 May 14.

Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.

: Vaccine hesitancy has been recognized as an urgent public health issue. We aimed to explore the acceptance of a COVID-19 vaccine and related factors among pregnant women, a vulnerable population for vaccine-preventable diseases. A multi-center cross-sectional study among pregnant women was conducted in five provinces of mainland China from November 13 to 27, 2020. We collected sociodemographic characteristics, attitude, knowledge, and health beliefs on COVID-19 vaccination. Locally weighted scatterplot smoothing regression analysis was used to assess the trends of vaccination acceptance. Multivariable logistic regression was performed to identify factors related to vaccination acceptance. Among the 1392 pregnant women, the acceptance rate of a COVID-19 vaccine were 77.4% (95%CI 75.1-79.5%). In the multivariable regression model, the acceptance rate was associated with young age (aOR = 1.87, 95% CI: 1.20-2.93), western region (aOR = 2.73, 95% CI: 1.72-4.32), low level of education (aOR = 2.49, 95% CI: 1.13-5.51), late pregnancy (aOR = 1.49, 95% CI: 1.03-2.16), high knowledge score on COVID-19 (aOR = 1.05, 95% CI: 1.01-1.10), high level of perceived susceptibility (aOR = 2.18, 95% CI: 1.36-3.49), low level of perceived barriers (aOR = 4.76, 95% CI: 2.23-10.18), high level of perceived benefit (aOR = 2.18, 95% CI: 1.36-3.49), and high level of perceived cues to action (aOR = 15.70, 95% CI: 8.28-29.80). About one quarters of pregnant women have vaccine hesitancy. Our findings highlight that targeted and multipronged efforts are needed to build vaccine literacy and confidence to increase the acceptance of a COVID-19 vaccine during the COVID-19 pandemic, especially for vulnerable populations.
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http://dx.doi.org/10.1080/21645515.2021.1892432DOI Listing
May 2021

A "MOFs plus ZIFs" Strategy toward Ultrafine Co Nanodots Confined into Superficial N-Doped Carbon Nanowires for Efficient Oxygen Reduction.

ACS Appl Mater Interfaces 2020 Dec 24;12(49):54545-54552. Epub 2020 Nov 24.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China.

N-doped carbon-confined transition metal nanocatalysts display efficient oxygen reduction reaction (ORR) performance comparable to commercial Pt/C electrocatalysts because of their efficient charge transfer from metal atoms to active N sites. However, the sheathed active sites inside the electrocatalysts and relatively large-size confined metal particles greatly restrict their activity improvement. Here, we develop a facile and efficient "MOFs plus ZIFs" synthesis strategy to successfully construct ultrafine sub-5 nm Co nanodots confined into superficial N-doped carbon nanowires ([email protected]@NC) via a well-designed synthesis process. The unique synthesis mechanism is based on low-pressure vapor superassembly of thin zeolitic imidazolate framework (ZIF) coatings on metal-organic framework substrates. During the successive pyrolysis, the preferential formation of the robust N-doped carbon shell from the ZIF-67 shell keeps the core morphology without shrinkage and limits the growth of Co nanodots. Benefiting from this architecture with accessible and rich active N sites on the surface, stable carbon confined architecture, and large surface area, the [email protected]@NC exhibits excellent ORR performance, catching up to commercial Pt/C. Density functional theory demonstrates that the confined Co nanodots efficiently enhance the charge density of superficial active N sites by interfacial charge transfer, thus accelerating the ORR process.
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http://dx.doi.org/10.1021/acsami.0c14112DOI Listing
December 2020

Development of a standardized Gram stain procedure for bacteria and inflammatory cells using an automated staining instrument.

Microbiologyopen 2020 09 27;9(9):e1099. Epub 2020 Jun 27.

Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China.

Gram stain is a subjective and poorly controlled test, and the resultant errors often perplex laboratory scientists. To reduce errors and make Gram stain a precisely controllable and meritorious test, a standardized Gram stain procedure for bacteria and inflammatory cells was developed using an automated staining instrument in this study. Freshly expectorated sputum specimens, used as the optimized targets, were smeared on slides by laboratory technicians, defining each slide loaded with uniform matrix and monolayer cell. And then, the staining and decolorizing time, as well as the stain and decolorant volume, were optimized as 15, 105, 1, and 25 s and 1.1, 1.4, 0.3, and 0.7 ml, respectively. Culture-positive blood specimens and original purulent fluids were used for confirming the developed standardized Gram stain procedure. Distinct tinctures of bacteria and inflammatory cells adhered to slide uniformly in a monolayer were observed, and the obtained staining results of these samples were highly consistent with their cultured results. Furthermore, according to the staining results under different staining conditions, an updated molecular mechanism of Gram stain for bacteria and the probable staining mechanism for inflammatory cells were also proposed in this study.
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http://dx.doi.org/10.1002/mbo3.1099DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7520987PMC
September 2020

Highly Efficient Non-Nucleophilic Mg(CFSO)-Based Electrolyte for High-Power Mg/S Battery.

ACS Appl Mater Interfaces 2020 Apr 3;12(15):17474-17480. Epub 2020 Apr 3.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China.

The application of high-energy Mg/S batteries was obstructed by the insufficiency of low-cost and non-nucleophilic electrolyte. In this work, a non-nucleophilic electrolyte was prepared by facilely dissolving Mg(CFSO), MgCl, and AlCl in 1,2-dimethoxyethane (DME). The equilibrium species of the MTB electrolyte mainly comprise [Mg(μ-Cl)(DME)] and [(CFSO)AlCl], which are generated by dehalodimerization reaction and Lewis acid-base reaction, respectively. The electrolyte exhibits a highly efficient reversible Mg deposition/dissolution, low overpotential of around 250 mV, and good oxidative stability up to 3.5 V after conditioning. The conditioning process that the active [Mg(μ-Cl)(DME)] species transforms into [Mg(μ-Cl)(μ-Cl)(DME)] was demonstrated, owing to the irreversible deposition of Al on Mg foil. More importantly, this electrolyte exhibited good compatibility and kinetics for reversible Mg/MgS redox, resulting in a high specific capacity of 866 mAh g at 200 mA g and high power density of 550 W kg. This work offers a new direction for low-cost, non-nucleophilic electrolyte and paves the way to explore high-power Mg/S batteries.
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http://dx.doi.org/10.1021/acsami.0c00196DOI Listing
April 2020

MXene Surface Terminations Enable Strong Metal-Support Interactions for Efficient Methanol Oxidation on Palladium.

ACS Appl Mater Interfaces 2020 Jan 6;12(2):2400-2406. Epub 2020 Jan 6.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan 430070 , P. R. China.

Efficient catalysis of the methanol oxidation reaction (MOR) greatly determines the widespread implementation of direct methanol fuel cells. Exploring a suitable support for noble metal catalysts with regard to decreasing the mass loading and optimizing the MOR activity remains a key challenge. Herein, we achieve an over 60% activity enhancement of a palladium (Pd) catalyst by introducing a two-dimensional TiCT MXene as the support compared to a commercial Pd/C catalyst. Not only are more catalytically active Pd sites exposed on the Pd/MXene catalyst while maintaining a low mass loading, but the introduction of the MXene support also significantly alters the surface electronic structure of Pd. Specifically, spectroscopy and density functional theory (DFT) computations indicate that sufficiently electronegative terminations of the TiCT MXene surface can induce strong metal-support interactions (SMSI) with the Pd catalyst, leading to optimal methanol adsorption. This MXene-supported Pd catalyst exhibits a much higher MOR current density (12.4 mA cm) than that of commercial Pd/C (7.6 mA cm). Our work largely optimizes the intrinsic activity of a Pd catalyst by the utilization of MXene surface terminations, and the crucial SMSI effects revealed herein open a rational avenue to the design of more efficient noble metal catalysts for MOR.
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http://dx.doi.org/10.1021/acsami.9b17088DOI Listing
January 2020

ALDH1A1 Contributes to PARP Inhibitor Resistance via Enhancing DNA Repair in BRCA2 Ovarian Cancer Cells.

Mol Cancer Ther 2020 01 18;19(1):199-210. Epub 2019 Sep 18.

Department of Radiation Oncology, College of Medicine, The Ohio State University, Columbus, Ohio.

Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) are approved to treat recurrent ovarian cancer with or mutations, and as maintenance therapy for recurrent platinum-sensitive ovarian cancer (BRCA wild-type or mutated) after treatment with platinum. However, the acquired resistance against PARPi remains a clinical hurdle. Here, we demonstrated that PARP inhibitor (olaparib)-resistant epithelial ovarian cancer (EOC) cells exhibited an elevated aldehyde dehydrogenase (ALDH) activity, mainly contributed by increased expression of ALDH1A1 due to olaparib-induced expression of BRD4, a member of bromodomain and extraterminal (BET) family protein. We also revealed that ALDH1A1 enhanced microhomology-mediated end joining (MMEJ) activity in EOC cells with inactivated BRCA2, a key protein that promotes homologous recombination (HR) by using an intrachromosomal MMEJ reporter. Moreover, NCT-501, an ALDH1A1-selective inhibitor, can synergize with olaparib in killing EOC cells carrying BRCA2 mutation in both cell culture and the xenograft animal model. Given that MMEJ activity has been reported to be responsible for PARPi resistance in HR-deficient cells, we conclude that ALDH1A1 contributes to the resistance to PARP inhibitors via enhancing MMEJ in BRCA2 ovarian cancer cells. Our findings provide a novel mechanism underlying PARPi resistance in BRCA2-mutated EOC cells and suggest that inhibition of ALDH1A1 could be exploited for preventing and overcoming PARPi resistance in EOC patients carrying BRCA2 mutation.
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http://dx.doi.org/10.1158/1535-7163.MCT-19-0242DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6946874PMC
January 2020

Inhibition of miR-328-3p Impairs Cancer Stem Cell Function and Prevents Metastasis in Ovarian Cancer.

Cancer Res 2019 05 20;79(9):2314-2326. Epub 2019 Mar 20.

Department of Radiation Oncology, College of Medicine, The Ohio State University, Columbus, Ohio.

Cancer stem cells (CSC) play a central role in cancer metastasis and development of drug resistance. miRNA are important in regulating CSC properties and are considered potential therapeutic targets. Here we report that miR-328-3p (miR-328) is significantly upregulated in ovarian CSC. High expression of miR-328 maintained CSC properties by directly targeting DNA damage binding protein 2, which has been shown previously to inhibit ovarian CSC. Reduced activity of ERK signaling in ovarian CSC, mainly due to a low level of reactive oxygen species, contributed to the enhanced expression of miR-328 and maintenance of CSC. Inhibition of miR-328 in mouse orthotopic ovarian xenografts impeded tumor growth and prevented tumor metastasis. In summary, our findings provide a novel mechanism underlying maintenance of the CSC population in ovarian cancer and suggest that targeted inhibition of miR-328 could be exploited for the eradication of CSC and aversion of tumor metastasis in ovarian cancer. SIGNIFICANCE: These findings present inhibition of miR-328 as a novel strategy for efficient elimination of CSC to prevent tumor metastasis and recurrence in patients with epithelial ovarian cancer.
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http://dx.doi.org/10.1158/0008-5472.CAN-18-3668DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6777340PMC
May 2019

Micrometer-Sized Porous Fe N/C Bulk for High-Areal-Capacity and Stable Lithium Storage.

Small 2019 Jan 7;15(2):e1803572. Epub 2018 Dec 7.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China.

High-capacity anodes of lithium-ion batteries generally suffer from poor electrical conductivity, large volume variation, and low tap density caused by prepared nanostructures, which make it an obstacle to achieve both high-areal capacity and stable cycling performance for practical applications. Herein, micrometer-sized porous Fe N/C bulk is prepared to tackle the aforementioned issues, and thus realize both high-areal capacity and stable cycling performance at high mass loading. The porous structure in Fe N/C bulk is beneficial to alleviate the volumetric change. In addition, the N-doped carbon conducting networks with high electrical conductivity provide a fast charge transfer pathway. Meanwhile, the micrometer-sized Fe N/C bulk exhibits a higher tap density than that of commercial graphite powder (1.03 g cm ), which facilitates the preparation of thinner electrode at high mass loadings. As a result, a high-areal capacity of above 4.2 mA h cm at 0.45 mA cm is obtained at a high mass loading of 7.0 mg cm for LIBs, which still maintains at 2.59 mA h cm after 200 cycles with a capacity retention of 98.8% at 0.89 mA cm .
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http://dx.doi.org/10.1002/smll.201803572DOI Listing
January 2019

Porous CaFeO as a promising lithium ion battery anode: a trade-off between high capacity and long-term stability.

Nanoscale 2018 Jul;10(27):12963-12969

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, 430070, Hubei, China.

Metal oxides are considered as attractive candidates as anode materials for lithium ion batteries (LIBs) due to their high capacities compared to commercialized graphite. However, fast capacity fading, which is caused by inherent large volume expansions and agglomeration of active particles upon cycling, is a great challenge. Herein, we propose the design of porous CaFe2O4 electrode material to address the above issue. Compared to pristine iron oxides, CaFe2O4 exhibits a distinct trade-off in terms of high capacity and long-term stability, which is beneficial to the potential practical applications. Such a trade-off effect is attributed to the synergistic effect between the porous structure and the in situ formed CaO nanograins during charging/discharging processes. This work provides an effective strategy in achieving anode materials with high capacity and long-term stability for next-generation LIBs.
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http://dx.doi.org/10.1039/c8nr03840fDOI Listing
July 2018

DDB2 represses ovarian cancer cell dedifferentiation by suppressing ALDH1A1.

Cell Death Dis 2018 05 1;9(5):561. Epub 2018 May 1.

Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.

Cancer stem cells (CSCs), representing the root of many solid tumors including ovarian cancer, have been implicated in disease recurrence, metastasis, and therapeutic resistance. Our previous study has demonstrated that the CSC subpopulation in ovarian cancer can be limited by DNA damage-binding protein 2 (DDB2). Here, we demonstrated that the ovarian CSC subpopulation can be maintained via cancer cell dedifferentiation, and DDB2 is able to suppress this non-CSC-to-CSC conversion by repression of ALDH1A1 transcription. Mechanistically, DDB2 binds to the ALDH1A1 gene promoter, facilitating the enrichment of histone H3K27me3, and competing with the transcription factor C/EBPβ for binding to this region, eventually inhibiting the promoter activity of the ALDH1A1 gene. The de-repression of ALDH1A1 expression contributes to DDB2 silencing-augmented non-CSC-to-CSC conversion and expansion of the CSC subpopulation. We further showed that treatment with a selective ALDH1A1 inhibitor blocked DDB2 silencing-induced expansion of CSCs, and halted orthotopic xenograft tumor growth. Together, our data demonstrate that DDB2, functioning as a transcription repressor, can abrogate ovarian CSC properties by downregulating ALDH1A1 expression.
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http://dx.doi.org/10.1038/s41419-018-0585-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5948213PMC
May 2018

Three-dimensional carbon network confined antimony nanoparticle anodes for high-capacity K-ion batteries.

Nanoscale 2018 Apr;10(15):6820-6826

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.

Antimony (Sb) represents a promising anode for K-ion batteries (KIBs) due to its high theoretical capacity and suitable working voltage. However, the large volume change that occurs in the potassiation/depotassiation process can lead to severe capacity fading. Herein, we report a high-capacity anode material by in situ confining Sb nanoparticles in a three-dimensional carbon framework (3D [email protected]) via a template-assisted freeze-drying treatment and subsequent carbothermic reduction. The as-prepared 3D [email protected] hybrid material delivers high reversible capacity and good cycling stability when used as the anode for KIBs. Furthermore, cyclic voltammetry and in situ X-ray diffraction analysis were performed to reveal the intrinsic mechanism of a K-Sb alloying reaction. Therefore, this work is of great importance to understand the electrochemical process of the Sb-based alloying reaction and will pave the way for the exploration of high performance KIB anode materials.
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http://dx.doi.org/10.1039/c8nr00237aDOI Listing
April 2018

Depleting ovarian cancer stem cells with calcitriol.

Oncotarget 2018 Mar 16;9(18):14481-14491. Epub 2018 Feb 16.

Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH 43210, USA.

Cancer stem cells (CSCs) represent the root of many solid tumors including ovarian cancer. Eradication of CSCs represents a novel cancer therapeutic strategy. Calcitriol, also known as 1,25-dihydroxyvitamin D [1,25(OH)D], is an active metabolite of vitamin D, functioning as a potent steroid hormone. Calcitriol has shown anti-tumor effects in various cancers by regulating multiple signaling pathways. It has been reported that calcitriol can regulate the properties of normal and CSCs. However, the effect of calcitriol on the ovarian cancer growth and ovarian CSCs is still unclear. Here, by using a mouse subcutaneous xenograft model generated with human ovarian cancer cells, we have demonstrated that administration of calcitriol is able to strikingly delay the tumor growth. Calcitriol treatment can also deplete the ovarian CSC population characterized by ALDH and CD44CD117; decrease their capacity to form sphere under the CSC culture condition, and reduce the frequency of tumor-initiating cells, as evaluated by limiting dilution analysis. Mechanistic investigation revealed that calcitriol depletes CSCs via the nuclear vitamin D receptor (VDR)-mediated inhibition of the Wnt pathway. Furthermore, the activation of VDR pathway is more sensitive to calcitriol in ovarian CSCs than in non-CSCs, although the expression levels of VDR are comparable. Taken together, our data indicate that calcitriol is able to deplete the ovarian CSC population by inhibiting their Wnt signaling pathway, consequently, impeding the growth of xenograft tumors.
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http://dx.doi.org/10.18632/oncotarget.24520DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5865684PMC
March 2018

Cascade Radical 1,6-Addition/Cyclization of para-Quinone Methides: Leading to Spiro[4.5]deca-6,9-dien-8-ones.

Org Lett 2018 04 26;20(7):1974-1977. Epub 2018 Mar 26.

State Key Laboratory of Natural Medicines and Department of Medicinal Chemistry, School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , P. R. China.

A cascade three-component iodoazidation of para-quinone methides to construct spiro[4.5]deca-6,9-dien-8-ones under mild conditions has been developed. The chemoselective 1,6-addition of azide radical triggered a regioselective 5-exo-dig cyclization/radical coupling sequence, enabling C-N, C-C, and C-I bond formations in a one-pot procedure with high efficiency.
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http://dx.doi.org/10.1021/acs.orglett.8b00518DOI Listing
April 2018

UV radiation-induced SUMOylation of DDB2 regulates nucleotide excision repair.

Carcinogenesis 2017 10;38(10):976-985

Department of Radiology.

Subunit 2 of DNA damage-binding protein complex (DDB2) is an early sensor of nucleotide excision repair (NER) pathway for eliminating DNA damage induced by UV radiation (UVR) and cisplatin treatments of mammalian cells. DDB2 is modified by ubiquitin and poly(ADP-ribose) (PAR) in response to UVR, and these modifications play a crucial role in regulating NER. Here, using immuno-analysis of irradiated cell extracts, we have identified multiple post-irradiation modifications of DDB2 protein. Interestingly, although the DNA lesions induced by both UVR and cisplatin are corrected by NER, only the UV irradiation, but not the cisplatin treatment, induces any discernable DDB2 modifications. We, for the first time, show that the appearance of UVR-induced DDB2 modifications depend on the binding of DDB2 to the damaged chromatin and the participation of functionally active 26S proteasome. The in vitro and in vivo analysis revealed that SUMO-1 conjugations comprise a significant portion of these UVR-induced DDB2 modifications. Mapping of SUMO-modified sites demonstrated that UVR-induced SUMOylation occurs on Lys-309 residue of DDB2 protein. Mutation of Lys-309 to Arg-309 diminished the DDB2 SUMOylation observable both in vitro and in vivo. Moreover, K309R mutated DDB2 lost its function of recruiting XPC to the DNA damage sites, as well as the ability to repair cyclobutane pyrimidine dimers following cellular UV irradiation. Taken together, our results indicate that DDB2 is modified by SUMOylation upon UV irradiation, and this post-translational modification plays an important role in the initial recognition and processing of UVR-induced DNA damage occurring within the context of chromatin.
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http://dx.doi.org/10.1093/carcin/bgx076DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7446238PMC
October 2017

Oxalate-assisted formation of uniform carbon-confined SnO nanotubes with enhanced lithium storage.

Chem Commun (Camb) 2017 Aug;53(69):9542-9545

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China.

SnO nanotubes are synthesized via an oxalate-assisted "redox etching and precipitating" route between MnOOH nanowires and Sn ions. The addition of oxalate is found to be crucial to guide the formation of uniform SnO nanotubes. To further improve the conductivity and stability, the as-obtained SnO nanotubes are coated with a thin carbon layer. The resulting carbon-confined SnO nanotubes possess superior rate performance as an anode material for lithium-ion batteries.
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http://dx.doi.org/10.1039/c7cc05406hDOI Listing
August 2017

VO Nanoflakes as the Cathode Material of Hybrid Magnesium-Lithium-Ion Batteries with High Energy Density.

ACS Appl Mater Interfaces 2017 May 15;9(20):17060-17066. Epub 2017 May 15.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Hubei, Wuhan 430070, China.

The hybrid magnesium-lithium-ion batteries (MLIBs) combining the dendrite-free deposition of the Mg anode and the fast Li intercalation cathode are better alternatives to Li-ion batteries (LIBs) in large-scale power storage systems. In this article, we reported hybrid MLIBs assembled with the VO cathode, dendrite-free Mg anode, and the Mg-Li dual-salt electrolyte. Satisfactorily, the VO cathode delivered a stable plateau at about 1.75 V, and a high specific discharge capacity of 244.4 mA h g. To the best of our knowledge, the VO cathode displays the highest energy density of 427 Wh kg among reported MLIBs in coin-type batteries. In addition, an excellent rate performance and a wide operating temperature window from 0 to 55 °C have been obtained. The combination of VO cathode, dual-salt electrolyte, and Mg anode would pave the way for the development of high energy density, safe, and low-cost batteries.
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http://dx.doi.org/10.1021/acsami.7b02480DOI Listing
May 2017

Organocatalyzed [3 + 2] Annulation of Cyclopropenones and β-Ketoesters: An Approach to Substituted Butenolides with a Quaternary Center.

Org Lett 2017 02 30;19(4):778-781. Epub 2017 Jan 30.

State Key Laboratory of Natural Medicines and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University , Nanjing 210009, P. R. China.

An unprecedented organocatalyzed [3 + 2] annulation of cyclopropenones and β-ketoesters has been developed. This reaction provides a direct approach to highly substituted butenolides with a quaternary center in moderate to good yields. The preliminary mechanism study verified that the enol intermediate is crucial to the reaction outcome and the intermolecular esterification and intramolecular Michael addition process were involved.
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http://dx.doi.org/10.1021/acs.orglett.6b03737DOI Listing
February 2017

The Stress-responsive Gene ATF3 Mediates Dichotomous UV Responses by Regulating the Tip60 and p53 Proteins.

J Biol Chem 2016 May 18;291(20):10847-57. Epub 2016 Mar 18.

From the Georgia Cancer Center and Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, Georgia 30912,

The response to UV irradiation is important for a cell to maintain its genetic integrity when challenged by environmental genotoxins. An immediate early response to UV irradiation is the rapid induction of activating transcription factor 3 (ATF3) expression. Although emerging evidence has linked ATF3 to stress pathways regulated by the tumor suppressor p53 and the histone acetyltransferase Tip60, the role of ATF3 in the UV response remains largely unclear. Here, we report that ATF3 mediated dichotomous UV responses. Although UV irradiation enhanced the binding of ATF3 to Tip60, knockdown of ATF3 expression decreased Tip60 stability, thereby impairing Tip60 induction by UV irradiation. In line with the role of Tip60 in mediating UV-induced apoptosis, ATF3 promoted the death of p53-defective cells in response to UV irradiation. However, ATF3 could also activate p53 and promote p53-mediated DNA repair, mainly through altering histone modifications that could facilitate recruitment of DNA repair proteins (such as DDB2) to damaged DNA sites. As a result, ATF3 rather protected the p53 wild-type cells from UV-induced apoptosis. Our results thus indicate that ATF3 regulates cell fates upon UV irradiation in a p53-dependent manner.
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http://dx.doi.org/10.1074/jbc.M115.713099DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4865929PMC
May 2016

Single-Nanowire Electrochemical Probe Detection for Internally Optimized Mechanism of Porous Graphene in Electrochemical Devices.

Nano Lett 2016 Mar 19;16(3):1523-9. Epub 2016 Feb 19.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, China.

Graphene has been widely used to enhance the performance of energy storage devices due to its high conductivity, large surface area, and excellent mechanical flexibility. However, it is still unclear how graphene influences the electrochemical performance and reaction mechanisms of electrode materials. The single-nanowire electrochemical probe is an effective tool to explore the intrinsic mechanisms of the electrochemical reactions in situ. Here, pure MnO2 nanowires, reduced graphene oxide/MnO2 wire-in-scroll nanowires, and porous graphene oxide/MnO2 wire-in-scroll nanowires are employed to investigate the capacitance, ion diffusion coefficient, and charge storage mechanisms in single-nanowire electrochemical devices. The porous graphene oxide/MnO2 wire-in-scroll nanowire delivers an areal capacitance of 104 nF/μm(2), which is 4.0 and 2.8 times as high as those of reduced graphene oxide/MnO2 wire-in-scroll nanowire and MnO2 nanowire, respectively, at a scan rate of 20 mV/s. It is demonstrated that the reduced graphene oxide wrapping around the MnO2 nanowire greatly increases the electronic conductivity of the active materials, but decreases the ion diffusion coefficient because of the shielding effect of graphene. By creating pores in the graphene, the ion diffusion coefficient is recovered without degradation of the electron transport rate, which significantly improves the capacitance. Such single-nanowire electrochemical probes, which can detect electrochemical processes and behavior in situ, can also be fabricated with other active materials for energy storage and other applications in related fields.
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http://dx.doi.org/10.1021/acs.nanolett.5b03576DOI Listing
March 2016

Differential DNA lesion formation and repair in heterochromatin and euchromatin.

Carcinogenesis 2016 Feb 30;37(2):129-38. Epub 2015 Dec 30.

Department of Radiology and James Cancer Hospital and Solove Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA

Discretely orchestrated chromatin condensation is important for chromosome protection from DNA damage. However, it is still unclear how different chromatin states affect the formation and repair of nucleotide excision repair (NER) substrates, e.g. ultraviolet (UV)-induced cyclobutane pyrimidine dimers (CPD) and the pyrimidine (6-4) pyrimidone photoproducts (6-4PP), as well as cisplatin-induced intrastrand crosslinks (Pt-GG). Here, by using immunofluorescence and chromatin immunoprecipitation assays, we have demonstrated that CPD, which cause minor distortion of DNA double helix, can be detected in both euchromatic and heterochromatic regions, while 6-4PP and Pt-GG, which cause major distortion of DNA helix, can exclusively be detected in euchromatin, indicating that the condensed chromatin environment specifically interferes with the formation of these DNA lesions. Mechanistic investigation revealed that the class III histone deacetylase SIRT1 is responsible for restricting the formation of 6-4PP and Pt-GG in cells, probably by facilitating the maintenance of highly condensed heterochromatin. In addition, we also showed that the repair of CPD in heterochromatin is slower than that in euchromatin, and DNA damage binding protein 2 (DDB2) can promote the removal of CPD from heterochromatic region. In summary, our data provide evidence for differential formation and repair of DNA lesions that are substrates of NER. Both the sensitivity of DNA to damage and the kinetics of repair can be affected by the underlying level of chromatin compaction.
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http://dx.doi.org/10.1093/carcin/bgv247DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5006209PMC
February 2016

miR-93 promotes TGF-β-induced epithelial-to-mesenchymal transition through downregulation of NEDD4L in lung cancer cells.

Tumour Biol 2016 Apr 18;37(4):5645-51. Epub 2015 Nov 18.

Department of Radiology, The Ohio State University Wexner Medical Center, Room 1014, 460 W. 12th Ave, Columbus, OH, 43210, USA.

The level of microRNA-93 (miR-93) in tumors has been recently reported to be negatively correlated with survival of lung cancer patients. Considering that the most devastating aspect of lung cancer is metastasis, which can be promoted by transforming growth factor-β (TGF-β)-induced epithelial-to-mesenchymal transition (EMT), we sought to determine whether miR-93 is involved in this process. Here, we report that a previously unidentified target of miR-93, neural precursor cell expressed developmentally downregulated gene 4-like (NEDD4L), is able to mediate TGF-β-mediated EMT in lung cancer cells. miR-93 binds directly to the 3'-UTR of the NEDD4L messenger RNA (mRNA), leading to a downregulation of NEDD4L expression at the protein level. We next demonstrated that the downregulation of NEDD4L enhanced, while overexpression of NEDD4L reduced TGF-β signaling, reflected by increased phosphorylation of SMAD2 in the lung cancer cell line after TGF-β treatment. Furthermore, overexpression of miR-93 in lung cancer cells promoted TGF-β-induced EMT through downregulation of NEDD4L. The analysis of publicly available gene expression array datasets indicates that low NEDD4L expression correlates with poor outcomes among patients with lung cancer, further supporting the oncogenic role of miR-93 in lung tumorigenesis and metastasis.
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http://dx.doi.org/10.1007/s13277-015-4328-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6528179PMC
April 2016

Arbitrary Shape Engineerable Spiral Micropseudocapacitors with Ultrahigh Energy and Power Densities.

Adv Mater 2015 Dec 13;27(45):7476-82. Epub 2015 Oct 13.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, P. R. China.

Inspired by the Archimedean spiral, a new integrated design of micropseudocapacitors is presented. The fabricated micropseudocapacitors deliver an energy density of 34.9 mW h cm(-3) and a power density of 193.4 W cm(-3). Meanwhile, this spiral design can be engineered into arbitrary microshapes and unconventional series/parallel combinations with symmetrical electrodes.
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http://dx.doi.org/10.1002/adma.201503567DOI Listing
December 2015

Pigeons are resistant to experimental infection with H7N9 avian influenza virus.

Avian Pathol 2015 Oct;44(5):342-6

a Institute of Animal and Husbandry Medicine , Beijing Academy of Agriculture and Forestry Sciences , Beijing , People's Republic of China.

To determine the susceptibility of pigeons to the newly emerged avian influenza virus subtype H7N9, we experimentally infected three different types of pigeons (meat, town, and racing) with two different doses (2 × 10(4) or 2 × 10(5) EID50) of H7N9 avian influenza virus A/Chicken/China/2013 by either intranasal and intraocular inoculation (IN + IO) or intravenous injection (IV). In addition, the potential transmission of H7N9 to pigeons by direct close contact with experimentally infected pigeons and chickens was assessed. Results showed that none of the experimentally infected pigeons exhibited any clinical signs regardless of the infection route and dose. Of the 12 racing pigeons that were randomly selected and necropsied, none of them had any gross lesions. In agreement with this finding, virus was not isolated from all pigeons. No detectable H7-specific antibodies were found in any pigeon. In contrast, 11 of 31 chickens that were either directly infected with H7N9 by IN + IO inoculation or by contact with IN + IO-infected chickens had conjunctivitis. Virus was isolated from all 31 chickens and H7-specific antibodies were detected in these chickens. However, none of the IV-infected chickens or chickens in direct contact with IV-infected chickens had any clinical signs. No virus was isolated from these chickens and no H7-specific antibody was detected. Overall, we conclude that pigeons are less or not susceptible to the H7N9 virus at the doses used and are not likely to serve as a reservoir for the virus. However, the virus does cause conjunctivitis in chickens and can transmit to susceptible hosts by direct contact.
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http://dx.doi.org/10.1080/03079457.2015.1055235DOI Listing
October 2015

DDB2 modulates TGF-β signal transduction in human ovarian cancer cells by downregulating NEDD4L.

Nucleic Acids Res 2015 Sep 29;43(16):7838-49. Epub 2015 Jun 29.

Division of Radiobiology, Department of Radiology, The Ohio State University Medical Center, Columbus, OH 43210, USA Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA

The expression of DNA damage-binding protein 2 (DDB2) has been linked to the prognosis of ovarian cancer and its underlying transcription regulatory function was proposed to contribute to the favorable treatment outcome. By applying gene microarray analysis, we discovered neural precursor cell expressed, developmentally downregulated 4-Like (NEDD4L) as a previously unidentified downstream gene regulated by DDB2. Mechanistic investigation demonstrated that DDB2 can bind to the promoter region of NEDD4L and recruit enhancer of zeste homolog 2 histone methyltransferase to repress NEDD4L transcription by enhancing histone H3 lysine 27 trimethylation (H3K27me3) at the NEDD4L promoter. Given that NEDD4L plays an important role in constraining transforming growth factor β signaling by targeting activated Smad2/Smad3 for degradation, we investigated the role of DDB2 in the regulation of TGF-β signaling in ovarian cancer cells. Our data indicate that DDB2 enhances TGF-β signal transduction and increases the responsiveness of ovarian cancer cells to TGF-β-induced growth inhibition. The study has uncovered an unappreciated regulatory mode that hinges on the interaction between DDB2 and NEDD4L in human ovarian cancer cells. The novel mechanism proposes the DDB2-mediated fine-tuning of TGF-β signaling and its downstream effects that impinge upon tumor growth in ovarian cancers.
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http://dx.doi.org/10.1093/nar/gkv667DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4652750PMC
September 2015

General synthesis of complex nanotubes by gradient electrospinning and controlled pyrolysis.

Nat Commun 2015 Jun 11;6:7402. Epub 2015 Jun 11.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.

Nanowires and nanotubes have been the focus of considerable efforts in energy storage and solar energy conversion because of their unique properties. However, owing to the limitations of synthetic methods, most inorganic nanotubes, especially for multi-element oxides and binary-metal oxides, have been rarely fabricated. Here we design a gradient electrospinning and controlled pyrolysis method to synthesize various controllable 1D nanostructures, including mesoporous nanotubes, pea-like nanotubes and continuous nanowires. The key point of this method is the gradient distribution of low-/middle-/high-molecular-weight poly(vinyl alcohol) during the electrospinning process. This simple technique is extended to various inorganic multi-element oxides, binary-metal oxides and single-metal oxides. Among them, Li3V2(PO4)3, Na0.7Fe0.7Mn0.3O2 and Co3O4 mesoporous nanotubes exhibit ultrastable electrochemical performance when used in lithium-ion batteries, sodium-ion batteries and supercapacitors, respectively. We believe that a wide range of new materials available from our composition gradient electrospinning and pyrolysis methodology may lead to further developments in research on 1D systems.
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http://dx.doi.org/10.1038/ncomms8402DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4490406PMC
June 2015

XPC inhibits NSCLC cell proliferation and migration by enhancing E-Cadherin expression.

Oncotarget 2015 Apr;6(12):10060-72

Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.

Xeroderma pigmentosum complementation group C (XPC) protein is an important DNA damage recognition factor in nucleotide excision repair. Deletion of XPC is associated with early stages of human lung carcinogenesis, and reduced XPC mRNA levels predict poor patient outcome for non-small cell lung cancer (NSCLC). However, the mechanisms linking loss of XPC expression and poor prognosis in lung cancer are still unclear. Here, we report evidence that XPC silencing drives proliferation and migration of NSCLC cells by down-regulating E-Cadherin. XPC knockdown enhanced proliferation and migration while decreasing E-Cadherin expression in NSCLC cells with an epithelial phenotype. Restoration of E-Cadherin in these cells suppressed XPC knockdown-induced cell growth both in vitro and in vivo. Mechanistic studies showed that the loss of XPC repressed E-Cadherin expression by activating the ERK pathway and upregulating Snail expression. Our findings indicate that XPC silencing-induced reduction of E-Cadherin expression contributes, at least in part, to the poor outcome of NSCLC patients with low XPC expression.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4496340PMC
http://dx.doi.org/10.18632/oncotarget.3542DOI Listing
April 2015

Enhanced expression of DNA polymerase eta contributes to cisplatin resistance of ovarian cancer stem cells.

Proc Natl Acad Sci U S A 2015 Apr 23;112(14):4411-6. Epub 2015 Mar 23.

Department of Radiology, Comprehensive Cancer Center,

Cancer stem cells (CSCs) with enhanced tumorigenicity and chemoresistance are believed to be responsible for treatment failure and tumor relapse in ovarian cancer patients. However, it is still unclear how CSCs survive DNA-damaging agent treatment. Here, we report an elevated expression of DNA polymerase η (Pol η) in ovarian CSCs isolated from both ovarian cancer cell lines and primary tumors, indicating that CSCs may have intrinsically enhanced translesion DNA synthesis (TLS). Down-regulation of Pol η blocked cisplatin-induced CSC enrichment both in vitro and in vivo through the enhancement of cisplatin-induced apoptosis in CSCs, indicating that Pol η-mediated TLS contributes to the survival of CSCs upon cisplatin treatment. Furthermore, our data demonstrated a depletion of miR-93 in ovarian CSCs. Enforced expression of miR-93 in ovarian CSCs reduced Pol η expression and increased their sensitivity to cisplatin. Taken together, our data suggest that ovarian CSCs have intrinsically enhanced Pol η-mediated TLS, allowing CSCs to survive cisplatin treatment, leading to tumor relapse. Targeting Pol η, probably through enhancement of miR-93 expression, might be exploited as a strategy to increase the efficacy of cisplatin treatment.
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http://dx.doi.org/10.1073/pnas.1421365112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4394248PMC
April 2015

Interwoven three-dimensional architecture of cobalt oxide [email protected](x)Co(2x)(OH)(6x) for high-performance supercapacitors.

Nano Lett 2015 Mar 2;15(3):2037-44. Epub 2015 Mar 2.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, China.

Development of pseudocapacitor electrode materials with high comprehensive electrochemical performance, such as high capacitance, superior reversibility, excellent stability, and good rate capability at the high mass loading level, still is a tremendous challenge. To our knowledge, few works could successfully achieve the above comprehensive electrochemical performance simultaneously. Here we design and synthesize one interwoven three-dimensional (3D) architecture of cobalt oxide [email protected](x)Co(2x)(OH)(6x) ([email protected]) electrode with high comprehensive electrochemical performance: high specific capacitance (2550 F g(-1) and 5.1 F cm(-2)), good rate capability (82.98% capacitance retention at 20 A g(-1) vs 1 A g(-1)), superior reversibility, and cycling stability (92.70% capacitance retention after 5000 cycles at 20 A g(-1)), which successfully overcomes the tremendous challenge for pseudocapacitor electrode materials. The asymmetric supercapacitor of [email protected]//reduced-graphene-oxide-film exhibits good rate capability (74.85% capacitance retention at 10 A g(-1) vs 0.5 A g(-1)) and high energy density (78.75 Wh kg(-1) at a power density of 473 W kg(-1)). The design of this interwoven 3D frame architecture can offer a new and appropriate idea for obtaining high comprehensive performance electrode materials in the energy storage field.
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http://dx.doi.org/10.1021/nl504901pDOI Listing
March 2015

Stable alkali metal ion intercalation compounds as optimized metal oxide nanowire cathodes for lithium batteries.

Nano Lett 2015 Mar 9;15(3):2180-5. Epub 2015 Feb 9.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology , Wuhan 430070, China.

Intercalation of ions in electrode materials has been explored to improve the rate capability in lithium batteries and supercapacitors, due to the enhanced diffusion of Li(+) or electrolyte cations. Here, we describe a synergistic effect between crystal structure and intercalated ion by experimental characterization and ab initio calculations, based on more than 20 nanomaterials: five typical cathode materials together with their alkali metal ion intercalation compounds A-M-O (A = Li, Na, K, Rb; M = V, Mo, Co, Mn, Fe-P). Our focus on nanowires is motivated by general enhancements afforded by nanoscale structures that better sustain lattice distortions associated with charge/discharge cycles. We show that preintercalation of alkali metal ions in V-O and Mo-O yields substantial improvement in the Li ion charge/discharge cycling and rate, compared to A-Co-O, A-Mn-O, and A-Fe-P-O. Diffraction and modeling studies reveal that preintercalation with K and Rb ions yields a more stable interlayer expansion, which prevents destructive collapse of layers and allow Li ions to diffuse more freely. This study demonstrates that appropriate alkali metal ion intercalation in admissible structure can overcome the limitation of cyclability as well as rate capability of cathode materials, besides, the preintercalation strategy provides an effective method to enlarge diffusion channel at the technical level, and more generally, it suggests that the optimized design of stable intercalation compounds could lead to substantial improvements for applications in energy storage.
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http://dx.doi.org/10.1021/acs.nanolett.5b00284DOI Listing
March 2015

Manganese oxide/carbon yolk-shell nanorod anodes for high capacity lithium batteries.

Nano Lett 2015 Jan 12;15(1):738-44. Epub 2014 Dec 12.

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, WUT-Harvard Joint Nano Key Laboratory, Wuhan University of Technology , Wuhan 430070, China.

Transition metal oxides have attracted much interest for their high energy density in lithium batteries. However, the fast capacity fading and the low power density still limit their practical implementation. In order to overcome these challenges, one-dimensional yolk-shell nanorods have been successfully constructed using manganese oxide as an example through a facile two-step sol-gel coating method. Dopamine and tetraethoxysilane are used as precursors to obtain uniform polymer coating and silica layer followed by converting into carbon shell and hollow space, respectively. As anode material for lithium batteries, the manganese oxide/carbon yolk-shell nanorod electrode has a reversible capacity of 660 mAh/g for initial cycle at 100 mA/g and exhibits excellent cyclability with a capacity of 634 mAh/g after 900 cycles at a current density of 500 mA/g. An enhanced capacity is observed during the long-term cycling process, which may be attributed to the structural integrity, the stability of solid electrolyte interphase layer, and the electrochemical actuation of the yolk-shell nanorod structure. The results demonstrate that the manganese oxide is well utilized with the one-dimensional yolk-shell structure, which represents an efficient way to realize excellent performance for practical applications.
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http://dx.doi.org/10.1021/nl504427dDOI Listing
January 2015