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Efficient and stable electrocatalysts for oxygen reduction reaction and free-standing electrode structure were developed to reduce the use of polymer binder in the cathode of metal-air battery. Con...

Dihydroartemisinin (DHA) is a potent anti-cancer drug that has limited clinical applications due to poor water solubility and low bioavailability. We designed a biodegradable poly(ethylene glycol) methyl ether-poly(ε-caprolactone) (MPEG-PCL) micelle carrier for DHA using the self-assembly method. The DHA/MPEG-PCL nanoparticles were spherical with an average particle size of 30.28 ± 0.27 nm, and released the drug in a sustained manner in aqueous solution. The drug-loaded nanoparticles showed dose-dependent toxicity in HeLa cells by inducing cycle arrest and apoptosis. Furthermore, compared to free DHA, the DHA/MPEG-PCL nanoparticles showed higher therapeutic efficacy and lower toxicity in vivo, and significantly inhibited tumor growth and prolonged the survival of tumor-bearing nude mice. In addition, the tumor tissues of the DHA/MPEG-PCL-treated mice showed a marked decline in the in situ expression of proliferation and angiogenesis markers. Taken together, the self-assembled DHA/MPEG-PCL nanoparticles are a highly promising delivery system for targeted cancer treatment.

Skin repair remains a common problem in plastic surgery. Wound dressing plays an important role in promoting local skin healing and has been widely studied. This study aimed to manufacture a composite film (CPCF) containing curcumin nanoparticles, collagen, and polyvinyl alcohol (PVA) to effectively promote the healing of skin wounds. Sustained drug release from the composite film provides long-term protection and treatment for skin wounds. Both antibacterial property and good histocompatibility of the CPCF were examined by analyzing antibacterial activity and cytotoxicity to validate its applicability for wound management. Moreover, in vivo studies proved that the CPCF had a rapid healing rate of 98.03%±0.79% and mature epithelialization on day 15 after surgery. Obvious hair follicles and earlier re-epithelialization was also noticed in the CPCF group using H&E staining. The result of Masson’s trichrome staining confirmed that CPCF could promote the formation of collagen fibers. In summary, CPCF may be promising as a wound dressing agent in wound management owing to its rapid wound-healing effects.

All-solid-state batteries are expected to be promising next-generation energy storage systems with increased energy density compared to the state-of-the-art Li-ion batteries. Nonetheless, the electrochemical performances of the all-solid-state batteries are currently limited by the high interfacial resistance between active electrode materials and solid-state electrolytes. In particular, elemental interdiffusion and the formation of interlayers with low ionic conductivity are known to restrict the battery performance. Herein, we apply a nondestructive variable-energy hard X-ray photoemission spectroscopy to detect the elemental chemical states at the interface between the cathode and the solid-state electrolyte, in comparison to the widely used angle-resolved (variable-angle) X-ray photoemission spectroscopy/X-ray absorption spectroscopy methods. The accuracy of variable-energy hard X-ray photoemission spectroscopy is also verified with a focused ion beam and high-resolution transmission electron microscopy. We also show the significant suppression of interdiffusion by building an artificial layer via atomic layer deposition at this interface.

Most breast cancers at an advanced stage exhibit an aggressive nature, and there is a lack of effective anticancer options. Herein, the development of patient‐derived organoids (PDOs) is described as a real‐time platform to explore the feasibility of tailored treatment for refractory breast cancers. PDOs are successfully generated from breast cancer tissues, including heavily treated specimens. The microtubule‐targeting drug‐sensitive response signatures of PDOs predict improved distant relapse‐free survival for invasive breast cancers treated with adjuvant chemotherapy. It is further demonstrated that PDO pharmaco‐phenotyping reflects the previous treatment responses of the corresponding patients. Finally, as clinical case studies, all patients who receive at least one drug predicate to be sensitive by PDOs achieve good responses. Altogether, the PDO model is developed as an effective platform for evaluating patient‐specific drug sensitivity in vitro, which can guide personal treatment decisions for breast cancer patients at terminal stage., Personalized therapies are urgently needed for patients with advanced breast cancers. Patient‐derived organoids (PDOs) can be generated from breast cancer tissues for the identification of anticancer drugs with high efficacy. PDO pharmaco‐phenotyping can not only reflect the previous treatment responses of patients, but also serve as an in‐time platform to guide tailored therapy for the refractory disease.

As a competitive anode material for sodium-ion batteries (SIBs), a commercially available red phosphorus, featured with a high theoretical capacity (2596 mA h g–1) and a suitable operating voltage ...

Great efforts have been focused on studying high-efficiency and stable catalysts toward oxygen reduction reaction (ORR) in metal-air batteries. In view of synergistic effects and improved properties, carbon nanotubes and three-dimensional graphene (CNTs-3D graphene) hybrid catalysts developed via a well-controlled route are urgently required. Herein, a CoMn2O4 (CMO) nanoneedle-supported nitrogen-doped carbon nanotubes/3D graphene (NCNTs/3D graphene) composite was prepared by in situ chemical vapor deposition (CVD) along with hydrothermal methods over a Ni foam substrate. The cyclic voltammetry and linear sweep voltammograms results indicate that the CMO/NCNTs/3D graphene hybrid possesses remarkable electrocatalytic performance toward ORR in alkaline conditions compared with NCNTs/3D graphene, CMO/3D graphene, and 3D graphene catalysts, even outperforming the commercial 20 wt % Pt/C catalyst. Moreover, the Al-air coin cell employing CMO/NCNTs/3D graphene as cathode catalysts obtains an open circuit voltage of 1.55 V and a specific capacity of 312.8 mA h g-1, which are superior to the Al-air coin cell with NCNTs/3D graphene as catalysts. This work supplies new insights to advanced electrocatalysts introducing NCNTs/3D graphene as a catalyst support to develop scalable transition-metal oxide/NCNTs/3D graphene hybrids with excellent catalytic activity toward ORR in Al-air systems.

Postoperative adhesions are the most common complications of peri-abdominal surgery; they not only affect the patient's quality of life but also increase the risk of a subsequent surgery. The use of implantable dressings to physically block surgical wounds is the primary solution to prevent postoperative adhesions. In this study, we prepared naproxen nanoparticles that were loaded with chitosan hydrogel (CS/Nap hydrogel) to prevent postoperative adhesions. Our data confirmed that the prepared CS/Nap hydrogel was thermosensitive and suitable for injection. The efficacy of anti-adhesion in a rat model revealed that the hydrogel effectively separated from the wounds of the abdominal wall and cecum. On day 7 postsurgery, the wounds were completely covered by a new epithelial layer, whereas wounds in the negative control group were glued together. Additionally, the in vivo toxicity study showed that the CS/Nap hydrogel had fewer toxic and side effects on major tissues and organs, including the liver, spleen, heart, lung, and kidney. We showed that a drug delivery system based on CS/Nap hydrogel has the potential not only to prevent postoperative abdominal adhesions and relieve pain but also to contribute to the administration of the hydrophobic drug naproxen.

The enhancement of catalyst activity and stability by controlling the metal-support interaction is significantly important for the long-term operation of polymer electrolyte membrane fuel cells (PEMFCs). In this work, an extremely stable electrocatalyst of platinum nanoparticles (Pt NPs) immobilized on a carbon support via the bridge layer of nitrogen-doped tantalum oxide (N-Ta2O5) is proposed. The novel N-Ta2O5 bridge layer in between the Pt NPs and carbon surface is synthesized by an atomic layer deposition technique (ALD). It effectively prevents Pt nanocrystals from detachment, migration, and aggregation during the PEMFCs’ operation. Electrochemical results indicate that the Pt/N-ALDTa2O5/C electrocatalyst exhibits superior durability and sufficient catalytic activity for the oxygen reduction reaction, compared to the Pt/C catalyst. X-ray absorption spectroscopy illustrates the strong interactions between the Pt NPs and the N-Ta2O5-decorated carbon support. It is found that the bridge layer of N-Ta2O5 alters the electronic structure of the Pt nanocrystals and contributes to the significantly enhanced catalytic activity and durability for the Pt/N-ALDTa2O5/C catalyst. This strategy, by using ALD of N-doped metal oxide to tune the metal-support interface and results in strong metal-support interactions, will benefit the future design of new-generation electrocatalysts with even better activity and long-term durability for PEMFCs application.

Malignant ascites indicate the presence of malignant cells in the peritoneal cavity that lower patient survival and reduce quality of life. Current chemotherapy regimens suffer from the dilution of ascites and rapid metabolism limiting their therapeutic efficacy. The storage and sustained release of drugs at the tumor site represents a promising strategy to improve drug efficacy. The aim of this study was to develop injectable hyaluronic acid hydrogel containing polymeric gemcitabine nanoparticles and cisplatin for the local treatment of malignant ascites through a dual sustained drug release pattern. Cell uptake assays showed that the drug-loaded nanoparticles readily entered tumor cells. Apoptosis and cell cycle analysis showed that the hydrogel system could enhance tumor cell apoptosis and arrest more cells in the G1 phase. In vivo experiments indicated that mice treated with the drug-loaded hydrogels manifested the most significant efficacy in ascites volume, tumor nodules, body weight, abdominal circumference, and survival. The expression of Ki-67 and CD31 also significantly decreased compared with other groups, indicative of anti-tumor activity. In addition, intraperitoneal administration of the hydrogel system led to no significant damage to vital organs. These findings confirm the clinical potential of the drug-loaded hydrogel system for the treatment of malignant ascites.

Multi-drug chemotherapy has been one of the most popular strategies for the treatment of malignant tumors, and has achieved desirable therapeutic outcomes. The objective of the present study is to develop biodegradable PCEC nanoparticles (NPs) for the co-delivery of paclitaxel (PTX) and curcumin (CUR), and investigate the antitumor effect of the drug delivery system (DDS: PTX-CUR-NPs) against breast cancer both in vitro and in vivo. The prepared PTX-CUR-NPs had a small size of 27.97 ± 1.87 nm with a low polydispersity index (PDI, 0.197 ± 0.040). The results exhibited slow release of PTX and CUR from the DDS without any burst effect. Further, the PTX-CUR-NPs displayed a dose-dependent cytotoxicity in MCF-7 cells with a higher apoptosis rate (64.29% ± 1.97%) as compared to that of free drugs (PTX + CUR, 34.21% ± 0.81%). The cellular uptake study revealed that the drug loaded PCEC polymeric nanoparticles were more readily uptaken by tumor cells in vitro. To evaluate the in vivo anti-tumor effect, the PTX-CUR-NPs were intravenously administered to BALB/c nude mouse xenografted with MCF-7 cells and the results exhibited significant inhibition of tumor growth with prolonged survival time and reduced side effect when compared with free drugs (PTX + CUR). Moreover, the administration of PTX-CUR-NPs treatment led to lower Ki67 expression (p 0.05), and enhanced TUNEL positivity (higher apoptosis, p 0.01) in tumor cells as compared to other treatment groups, suggesting the therapeutic efficacy of the DDS. Altogether, the present study suggests that the DDS PTX-CUR-NPs could be employed for the effective treatment of breast cancers in near future.

Efficient and stable electrocatalysts for oxygen reduction reaction and freestanding electrode structure were developed to reduce the use of polymer binders in the cathode of metal-air batteries. Considering the unique geometrical configurations of helical carbon nanotubes (CNTs) and improved properties compared with straight CNTs, we prepared high-purity Co@CoO

Background. Cervical cancer (CC) is one of the most common female malignant tumors. And cervical intraepithelial neoplasia (CIN) is the precancerous lesion of CC, which can progress to invasive CC. MicroRNAs (miRNAs) have been found to be potential diagnostic biomarkers for CIN or CC. However, recently, the lack of sufficient studies about the diagnostic value of miRNAs for CIN made it challenging to separately investigate the diagnostic efficacy of miRNAs for CIN. Likewise, the conclusions among those studies were discordant. Therefore, we conducted this meta-analysis, aimed at evaluating the diagnostic efficacy of miRNAs for CIN and CC patients. Methods. Literature search was performed in PubMed, Embase, and Web of Science databases. Pooled sensitivity, specificity, and other diagnostic parameters were calculated through Stata 14.0 software. Furthermore, subgroup analyses and metaregression analysis were conducted to explore the main sources of heterogeneity. Results. Ten articles covering 50 studies were eligible, which included 5,908 patients and 4,819 healthy individuals. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were 0.81 (95% CI, 0.77-0.85), 0.86 (95% CI, 0.83-0.89), 5.9 (95% CI, 4.5-7.7), 0.22 (95% CI, 0.17-0.28), 27 (95% CI, 17-44), and 0.91 (95% CI, 0.88-0.93), respectively. Additionally, the ethnicity and internal reference were the main sources of heterogeneity. Conclusions. Circulating miRNAs can be a promising noninvasive diagnostic biomarker for CIN and early CC, especially miR-9 and miR-205, which need to be verified by large-scale studies.

All-solid-state batteries (ASSBs) have attracted much attention due to their enhanced energy density and safety as compared to traditional liquid-based batteries. However, cyclic performance depreciates due to microcrack formation and propagation at the interface of the solid-state electrolytes (SSEs) and electrodes. Herein, we studied the elastic and fracture behavior of atomic layer deposition (ALD) synthesized glassy lithium phosphate (LPO) and lithium tantalate (LTO) thin films as promising candidates for SSEs. The mechanical behavior of ALD prepared SSE thin films with a thickness range of 5 nm to 30 nm over suspended single-layer graphene was studied using an atomic force microscope (AFM) film deflection technique. Scanning transmission electron microscopy (STEM) coupled with AFM was used for microstructural analysis. LTO films exhibited higher stiffness and higher fracture forces as compared to LPO films. Fracture in LTO films occurred directly under the indenter in a brittle fashion, while LPO films failed by a more complex fracture mechanism including significant plastic deformation prior to the onset of complete fracture. The results and methodology described in this work open a new window to identify the potential influence of SSEs mechanical performance on their operation in flexible ASSBs.

A critical challenge for the commercialization of layer-structured nickel-rich lithium transition metal oxide cathodes for battery applications is their capacity and voltage fading, which originate from the disintegration and lattice phase transition of the cathode particles. The general approach of cathode particle surface modification could partially alleviate the degradation associated with surface processes, but it still fails to resolve this critical barrier. Here, we report that infusing the grain boundaries of cathode secondary particles with a solid electrolyte dramatically enhances the capacity retention and voltage stability of the cathode. We find that the solid electrolyte infused in the boundaries not only acts as a fast channel for lithium-ion transport, it also, more importantly, prevents penetration of the liquid electrolyte into the boundaries, and consequently eliminates the detrimental factors, which include cathode–liquid electrolyte interfacial reactions, intergranular cracking and layered-to-spinel phase transformation. This grain-boundary engineering approach provides design ideas for advanced cathodes for batteries. The development of Ni-rich layered lithium transition metal oxides is plagued by their voltage and capacity fading on battery cycling. Here, the authors demonstrate an effective approach to treat these problems by infusing a solid electrolyte into the grain boundaries of the secondary particles of these layered materials.

Lithium-ion sulfur batteries use nonlithium materials as the anode for extended cycle life. However, polysulfide shuttle reactions still occur on the nonmetal anodes (such as graphite and Si), and result in undesirable low Coulombic efficiency. In this work, we used Al2O3 layers coated by atomic layer deposition (ALD) technique to suppress the shuttle reactions. With the optimal thickness of 2 nm Al2O3 coated on graphite anode, the Coulombic efficiency of the sulfur cathode was improved from 84% to 96% in the first cycle, and from 94% to 97% in the subsequent cycles. As a result, the discharge capacity of the sulfur cathode was increased to 550 mAh g–1 in the 100th cycle, as compared with 440 mAh g–1 when the pristine graphite anode was used. The Al2O3 passivation layer minimizes the formation of insoluble sulfide (Li2S2, Li2S) on the surface of graphite anode and improves the efficiency and capacity retention of the graphite-sulfur batteries. The surface passivation strategy could also be used in other s...

Post-operative recurrence and metastasis is a major challenge for breast cancer treatment. Local chemotherapy is a promising strategy that can overcome this problem. In this study, we synthesized an injectable hyaluronic acid (HA)-based hydrogel loaded with paclitaxel (PTX) nanoparticles and epirubicin (EPB) (PPNPs/EPB@HA-Gel). PPNPs/EPB@HA-Gel steadily released the encapsulated drugs to achieve long-term inhibition of tumor recurrence and metastasis in a murine post-operative breast tumor model, which prolonged their survival without any systemic toxicity. The drug-loaded hydrogel inhibited the proliferation and migration of tumor cells in vitro, and significantly increased tumor cell apoptosis in vivo. Therefore, PPNPs/EPB@HA-Gel can be used as a local chemotherapeutic agent to prevent postoperative recurrence and metastasis of breast cancer.

Nanostructured sodium titanate has great potential for various applications such as sodium-ion batteries, photocatalysts, and waste treatment. Understanding the phase-transition mechanism in sodium titanate after annealing is fundamentally important to tune the structure, morphology, and property for targeted applications. In this work, we adopted amorphous sodium titanate grown on carbon nanotubes by an atomic layer deposition technique as a reference and used X-ray absorption spectroscopy (XAS) and scanning transmission X-ray microscopy (STXM), as well as a high-temperature in situ X-ray diffraction (XRD) technique, to elucidate the phase-transition mechanism of sodium titanate from amorphous to crystalline upon annealing from 25 °C to 900 °C. XAS and XRD analysis disclosed that anatase TiO2 first formed in the matrix of amorphous sodium titanate at 500 °C and then recrystallized into Na0.23TiO2 at 700 °C and 900 °C. XAS studies also revealed that the Ti atoms in sodium titanate were oxidized during the annealing process and reached an oxidation state about 3.8+ for Na0.23TiO2. The elevated annealing temperature increased the coordination number of Ti atoms and the crystallinity of sodium titanate. STXM chemical map provided spatial information and visualized evidence on the phase transition among amorphous sodium titanate, anatase TiO2, and Na0.23TiO2 in the samples annealed at intermediate temperatures (500 °C and 700 °C). This work provides a comprehensive understanding on the evolution of sodium titanate, in terms of crystal structure, electronic structure, chemical environment, and morphology, under different post annealing conditions.

Development of solid-state electrolyte (SSE) thin films is a key toward the fabrication of all-solid-state batteries (ASSBs). However, it is challenging for conventional deposition techniques to deposit uniform and conformal SSE thin films in a well-controlled fashion. In this study, atomic layer deposition (ALD) was used to fabricate lithium silicate thin films as a potential SSE for ASSBs. Lithium silicates thin films were deposited by combining ALD Li2O and SiO2 subcycles using lithium tert-butoxide, tetraethylorthosilane, and H2O as precursors. Uniform and self-limiting growth was achieved at temperatures between 225 and 300 °C. X-ray absorption spectroscopy analysis disclosed that the as-deposited lithium silicates were composed of SiO4 tetrahedron structure and lithium oxide as the network modifier. X-ray photoelectron spectroscopy confirmed the chemical states of Li in the thin films were the same with that in standard lithium silicate. With one to one subcycle of Li2O and SiO2 the thin films had a...

Metallic Na anode is considered as a promising alternative candidate for Na ion batteries (NIBs) and Na metal batteries (NMBs) due to its high specific capacity, and low potential. However, the unstable solid electrolyte interphase layer caused by serious corrosion and reaction in electrolyte will lead to big challenges, including dendrite growth, low Coulombic efficiency and even safety issues. In this paper, we first demonstrate the inorganic–organic coating via advanced molecular layer deposition (alucone) as a protective layer for metallic Na anode. By protecting Na anode with controllable alucone layer, the dendrites and mossy Na formation have been effectively suppressed and the lifetime has been significantly improved. Moreover, the molecular layer deposition alucone coating shows better performances than the atomic layer deposition Al2O3 coating. The novel design of molecular layer deposition protected Na metal anode may bring in new opportunities to the realization of the next-generation high ene...

Spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) is a promising high voltage cathode material for lithium ion batteries (LIBs). However, dissolution of Mn and unwanted side reactions between LNMO and the electrolyte raises several safety issues while also resulting in deteriorated electrochemical performance of LIBs at high working voltages. Here, we report the use of ultrathin atomic layer deposited (ALD) AlPO 4 thin film as a coating material for LNMO electrodes to circumvent the stated issues. The as-prepared AlPO 4 coated LNMO demonstrates excellent capacity retention with prolonged cycle life compared to the bare one. Synchrotron based X-ray spectroscopy was employed to understand how ultrathin coating layer improve the cycle life, and then develop a detailed mechanism for the effect of coating layer. Our studies revealed that using atomic scale coating layer with improved thermal stability effectively impede the side-reactions occurrence at high voltage, resulting in significantly improved safety and electrochemical performances.

Atomic layer deposition was employed to deposit maghemite (γ-Fe2O3) nanoparticles on carbon nanotubes (CNTs) to prepare the γ-Fe2O3@CNTs composites, which exhibit a superior lithium storage performance as the anode of lithium ion batteries (LIBs). The high reversible capacity of 859.7 mA h/g was observed after 400 cycles at a current density of 500 mA/g. Even at the high current density of 10000 mA/g, the specific cyclic capacity of 464.4 mA h/g can still be obtained. Furthermore, electron energy loss spectroscopy results reveal that the Fe chemical state plays a critical role in the evolution of the capacity of γ-Fe2O3@CNTs composite anodes during the cycling process. The incomplete conversion of the chemical state in γ-Fe2O3 reduces the capacity, while the recovery of the chemical state of γ-Fe2O3 during the cycling process may cause the increase in capacity. This work provides insight into understanding the detailed working mechanism of transition metal oxides in LIBs, which helps in the design of elec...

Lithium-rich layered material is one of the most promising candidates of cathode materials for next-generation electric vehicles. However, one of the major issues that pertains to this material is the oxygen release during initial charge, which results in low initial coulombic efficiency (CE), intense electrolyte oxidation and thermal instability. In this study, we have conducted aluminum phosphate (AlPO 4 ) coating via atomic layer deposition (ALD) approach to protect the surface of this cathode material powders. It was found that part of the C2/m Li 2 MnO 3 phase turned into a spinel-like phase during the ALD process. The oxygen release has been effectively suppressed by such transformation, the initial CE increased from 75.2% for the bare electrode to 86.2% for the electrode with only 5 ALD cycles of AlPO 4 coating. Furthermore, AlPO 4 was also found to be more effective in improving the thermal stability of the cathode material comparing to bare or Al 2 O 3 coated samples. Our study has provided a new possible solution towards cathode materials with high thermal resistance via conformal coating.

Magnetic nanoparticles have been one of the most attractive nanomaterials for various biomedical applications including magnetic resonance imaging (MRI), diagnostic contrast enhancement, magnetic cell separation, and targeted drug delivery. Three-dimensional (3-D) fibrous scaffolds have broad application prospects in the biomedical field, such as drug delivery and tissue engineering. In this work, a novel three-dimensional composite membrane composed of the tri-block copolymer poly(e-caprolactone)-poly(ethylene glycol)-poly(e-caprolactone) (PCL-PEG-PCL, PCEC) and magnetic iron oxide nanoparticles (Fe3O4 NPs) were fabricated using electrospinning technology. The physico-chemical properties of the PCEC/Fe3O4 membranes were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Morphological observation using scanning electron microscopy (SEM) showed that the composite fibers containing 5% Fe3O4 nanoparticles had a diameter of 250nm. In vitro cell culture of NIH 3T3 cells on the PCEC/Fe3O4 membranes showed that the PCEC/Fe3O4 fibers might be a suitable scaffold for cell adhesion. Moreover, MTT analysis also demonstrated that the membranes possessed lower cytotoxicity. Therefore, this study revealed that the magnetic PCEC/Fe3O4 fibers might have great potential for using in skin tissue engineering.

Titanium niobium oxide (TiNb2O7) has been regarded as a promising anode material for high-rate lithium ion batteries (LIBs) due to its potential to operate at high rates with improved safety and high theoretical capacity of 387 mA h g−1. Herein, three-dimensionally ordered macroporous (3DOM) TiNb2O7 composed of interconnected single-crystalline nanoparticles was prepared using polystyrene (PS) colloidal crystals as a hard template. The final product yields a homogeneous, continuous, and effective honeycomb-like construction. This architecture provides facile Li+ insertion/extraction and fast electron transfer pathway, enabling high-performance lithium ion pseudocapacitive behavior, leading to good electrochemical performance. As a result, the 3DOM-TiNb2O7 shows a remarkable rate capability (120 mA h g−1 at 50 C) and durable long-term cyclability (82% capacity retention over 1000 cycles at 10 C). The work presented herein holds great promise for future design of material structure, and demonstrates the great potential of TiNb2O7 as a practical high-rate anode material for LIBs.

Tantalum oxide (TaOx) nanoparticles (NPs) are deposited on a commercial Pt/C catalyst by an area-selective atomic layer deposition (ALD) approach to enhance the stability of the catalyst in proton exchange membrane fuel cells (PEMFCs). Due to the application of a blocking agent for protecting the Pt surface, TaOx particles are selectively nucleated and grown around Pt NPs. The TaOx loading on the Pt/C surface could be controlled precisely by varying the number of ALD cycles. When deposited on the Pt/C surface with 35 ALD cycles, the TaOx-anchored Pt NPs formed an excellent triple-junction structure of TaOx–Pt–carbon. The electrochemical durability tests indicated that the TaOx-anchored Pt/C catalyst showed comparable catalytic activity and superior long-term stability to Pt/C. Moreover, the long-term stability test in membrane electrode assembly (MEA) indicated a very low power density loss (12%) after a 120 h accelerated durability test. The significantly enhanced catalyst stability during PEMFCs operation is due to the anchoring effect of TaOxvia strong metal oxide–support interactions. This strategy shows great potential for developing highly stable catalysts for PEMFCs.

Graphene has been integrated in many heterogeneous structures in order to take advantage of its superior mechanical properties. However, the complex mechanical response of heterogeneous films incorporating graphene is not well understood. Here, we studied the mechanical behavior of atomic layer deposition (ALD) synthesized TiO2/graphene, as a representative building block of a typical composite, to understand the mechanical behavior of heterostructures using an experiment-computational approach. The inclusion of graphene was found to significantly enhance the Young's modulus of TiO2/graphene hetero-films for films below a critical thickness of 3 nm, beyond which the Young's modulus approaches that of pure TiO2 film. A rule-of-mixtures was found to reasonably estimate the modulus of the TiO2/graphene hetero-film. Experimentally, these hetero-films were observed to fail via brittle fracture. Complimentary density functional theory and finite element modeling demonstrates strong adhesion at the graphene TiO2 interface and that graphene serves as a reinforcement, providing the hetero-film with an ability to sustain significantly high stresses at the point of failure initiation. The results and methodology described herein can contribute to the rational design of strong and reliable ultrathin hetero-films for versatile applications.

The TP53-induced glycolysis and apoptosis regulator (TIGAR) is a p53 target gene, which functions to suppress reactive oxygen species (ROS) damage and protect cells from apoptosis. In this study, we investigated the role of TIGAR in nasopharyngeal carcinoma (NPC) tumorigenesis. Imnunohistochemical analysis of the tissue specimens from nasopharyngeal carcinoma patients showed a higher expression level of TIGAR in tumor tissues, compared with normal nasopharyngeal epithelium. Knockdown of TIGAR by lentivirus-shRNA in CNE-2 or 5-8F cells resulted in decreased cell growth, colony formation, migration, invasion, and induced apoptosis. TIGAR overexpression exerted the opposite effects except for apoptosis reduction. In the xenograft tumor models, TIGAR knockdown reduced tumor growth rate and weight, whereas TIGAR overexpression showed the opposite effects. In addition, the NF-κB signaling pathway was decreased in TIGAR silenced cells. In conclusion, our data demonstrated that TIGAR acted as an oncogene in NPC tumorigenesis, and knockdown of TIGAR inhibited NPC tumor growth through the NF-κB pathway.

Solid-state batteries have been considered as one of the most promising next-generation energy storage systems because of their high safety and energy density. Solid-state electrolytes are the key component of the solid-state battery, which exhibit high ionic conductivity, good chemical stability, and wide electrochemical windows. LATP [Li1.3Al0.3Ti1.7 (PO4)3] solid electrolyte has been widely investigated for its high ionic conductivity. Nevertheless, the chemical instability of LATP against Li metal has hindered its application in solid-state batteries. Here, we propose that atomic layer deposition (ALD) coating on LATP surfaces is able to stabilize the LATP/Li interface by reducing the side reactions. In comparison with bare LATP, the Al2O3-coated LATP by ALD exhibits a stable cycling behavior with smaller voltage hysteresis for 600 h, as well as small resistance. More importantly, on the basis of advanced characterizations such as high-resolution transmission electron spectroscope-electron energy loss spectroscopy, the lithium penetration into the LATP bulk and Ti4+ reduction are significantly limited. The results suggest that ALD is very effective in improving solid-state electrolyte/electrode interface stability.

A stable and conductive interface is one of the decisive factors in manipulating the performance of high voltage LiNi0.5Mn1.5O4 (LNMO) cathode for Li-ion batteries. Herein, a hybrid Li3PO4–TiO2 coating layer is designed as an interfacial material via controllable atomic layer deposition (ALD) on LNMO. The coating acts not just as a physical barrier to prevent the side-reactions between cathode and electrolyte at high voltage, more importantly, the hybrid coating material improves both interfacial ionic and electronic conductivities to build facile Li-ion and electron diffusion pathways for LNMO. The optimized LNMO demonstrates improved rate capability and long-life stability. The capacity retention is 81.2% comparing with 47.4% of bare LNMO at 0.5C after 300 cycles. Detailed surface structural evolution is studied via X-ray absorption near edge spectroscopy and transmission electron microscopy. This work provides new insights of hybrid interfacial design via ALD and promotes novel electrode architectures for batteries.

Aluminum-air batteries are a promising power supply for electronics due to their low cost and high energy density. However, portable coin-type Al-air batteries operating under ambient air condition for small electronic appliances have rarely been reported. Herein, coin cell-type Al-air batteries using cost-effective and eco-friendly chitosan hydrogel membranes modified by SiO2, SnO2, and ZnO have been prepared and assembled. The Al-air coin cell employing chitosan hydrogel membrane containing 10 wt % SiO2 as a separator exhibits better discharge performance with a higher flat voltage plateau, longer discharge duration, and higher power density than the cells using a chitosan hydrogel membrane containing SnO2 or ZnO. Moreover, we also demonstrate that the presented Al-air coin cell can be recycled by a series of eco-friendly procedures using food-grade ingredients, resulting in recycled products that are environmentally safe and ready for reuse. The Al-air coin cell adopting a recycled cathode from a fully discharged Al-air coin cell using the above-mentioned procedure has shown comparable performance to cells assembled with a new cathode. With these merits of enhanced electrochemical performance and recyclability, this new Al-air coin cell with modified chitosan hydrogel membrane can find wide applications for powering portable and small-size electronics.

Carbonate-based electrolytes demonstrate safe and stable electrochemical performance in lithium-sulfur batteries. However, only a few types of sulfur cathodes with low loadings can be employed and the underlying electrochemical mechanism of lithium-sulfur batteries with carbonate-based electrolytes is not well understood. Here, we employ in operando X-ray absorption near edge spectroscopy to shed light on a solid-phase lithium-sulfur reaction mechanism in carbonate electrolyte systems in which sulfur directly transfers to Li2S without the formation of linear polysulfides. Based on this, we demonstrate the cyclability of conventional cyclo-S8 based sulfur cathodes in carbonate-based electrolyte across a wide temperature range, from −20 °C to 55 °C. Remarkably, the developed sulfur cathode architecture has high sulfur content (>65 wt%) with an areal loading of 4.0 mg cm−2. This research demonstrates promising performance of lithium-sulfur pouch cells in a carbonate-based electrolyte, indicating potential application in the future., Carbonate-based electrolytes can impart advantages in lithium sulfur batteries, but performance is often limited by incompatibility with sulfur-based cathodes. Here the authors elucidate a mechanism for conversion of sulfur to lithium sulfide and demonstrate improved performance in a Li-S cell.

The development of solid-state electrolytes by atomic layer deposition (ALD) holds unparalleled advantages toward the fabrication of next-generation solid-state batteries. Lithium niobium oxide (LNO) thin films with well-controlled film thickness and composition were successfully deposited by ALD at a deposition temperature of 235 °C using lithium tert-butoxide and niobium ethoxide as Li and Nb sources, respectively. Furthermore, incorporation of higher Li content was achieved by increasing the Li-to-Nb subcycle ratio. In addition, detailed X-ray absorption near edge structure studies of the amorphous LNO thin films on the Nb L-edge revealed the existence of Nb as Nb5+ in a distorted octahedral structure. The octahedrons in niobium oxide thin films experienced severe distortions, which could be gradually alleviated upon the introduction of Li atoms into the thin films. The ionic conductivities of the as-prepared LNO thin films were also measured, with the highest value achieving 6.39 × 10–8 S cm–1 at 303 ...

A binder-free three-dimensional (3D) nanostructured air electrode composed of vertically grown nitrogen doped carbon nanotubes on carbon paper (NCNT-CP) is developed and applied to Na–O2 cells. The 3D architecture of the air electrode results in increased discharge capacity by optimizing the utilized area of the electrode material. The chemical and electrochemical reaction mechanisms of the cell are also explored with the use of synchrotron-based X-ray absorption spectroscopy (XAS). Investigation of the discharge product of Na–O2 cells during discharge and charge cycles using X-ray absorption near-edge structure (XANES) indicates that both sodium superoxide and peroxide are produced under various physicochemical conditions and can be subsequently decomposed with different overpotentials. Furthermore, formation of carbonate-based parasitic products is also shown to restrict the cyclability of the cell.

Self-stacked nitrogen-doped carbon nanotubes (NCNTs) and pristine carbon nanotubes (CNTs) on commercial porous polypropylene substrates have been applied as air electrodes for sodium-air batteries (SAB). Both NCNT and CNT air electrodes exhibit highly reversible electrochemical activities and large capacities under low current densities in SABs, while NCNT electrodes show much higher rate performance and extended cycling life under high current densities. The superior electrochemical behavior of NCNT electrodes is attributed to the robust network of aligned NCNTs, which enables rapid oxygen and liquid electrolyte transport while accommodating the volume change originating from discharge product aggregation during cycling. Moreover, uniform coverage of the discharge product has been observed on the NCNT air electrodes, in contrast to the random and discrete dispersion of discharge product on the CNT air electrodes. The unique morphologies and growth mechanism of discharge products on NCNT electrodes are believed to be due to the outstanding catalytic activity of the nitrogen-doped sites in the NCNTs, which play a critical role in the high cycling stability of NCNT air electrodes for SABs.

Graphene has been integrated in many heterogeneous structures in order to take advantage of its superior mechanical properties. However, the complex mechanical response of heterogeneous films incorporating graphene is not well understood. Here, we studied the mechanical behavior of atomic layer deposition (ALD) synthesized TiO

Rechargeable metal–air batteries are widely considered as the next generation high energy density electrochemical storage devices. The performance and rechargeability of these metal–air cells are highly dependent on the positive electrode material, where oxygen reduction and evolution reactions take place. Here, for the first time, we provide a detailed account of the kinetics and rechargeability of sodium–air batteries through a series of carefully designed tests on a treated commercial carbon material. Surface area and porous structure of the positive electrode material were controlled in order to gain detailed information about the reaction kinetics of sodium–air batteries. The results indicate that discharge capacity is linearly correlated with surface area while morphology of the solid discharge product is strongly dependent on specific surface area and pore size. Furthermore, it was found that the chemical composition of discharge products as well as charging overpotential is affected by discharge reaction rate.

Na-metal batteries are considered as the promising alternative candidate for Li-ion battery beneficial from the wide availability and low cost of sodium, high theoretical specific capacity, and high energy density based on the plating/stripping processes and lowest electrochemical potential. For Na-metal batteries, the crucial problem on metallic Na is one of the biggest challenges. Mossy or dendritic growth of Na occurs in the repetitive Na stripping/plating process with an unstable solid electrolyte interphase layer of nonuniform ionic flux, which can not only lead to the low Coulombic efficiency, but also can create short circuit risks, resulting in possible burning or explosion. In this communication, the atomic layer deposition of Al2O3 coating is first demonstrated for the protection of metallic Na anode for Na-metal batteries. By protecting Na foil with ultrathin Al2O3 layer, the dendrites and mossy Na formation have been effectively suppressed and lifetime has been significantly improved. Furthermore, the thickness of protective layer has been further optimized with 25 cycles of Al2O3 layer presenting the best performance over 500 cycles. The novel design of atomic layer deposition protected metal Na anode may bring in new opportunities to the realization of the next-generation high energy-density Na metal batteries.

Graphene nanoribbons (GNRs) from chemical unzipping of carbon nanotubes (CNTs) have been reported to be a suitable candidate for lithium ion battery materials, but very few of them focused on controlling GNRs with different unzipping levels. Here we present a study of GNRs with controlled unzipping level and the prevailing factors that affect the lithium storage performance at early and final unzipping level; besides, the effect of thermal reduction has been investigated. On the basis of Raman and BET surface area tests, we found that the unzipping of CNTs starts with surface etching and then proceeds to partial and full unzipping and finally fragmentation and aggregation. Galvanostatic charge–discharge reveals that defect increase is mainly responsible for the capacity enhancement at the early unzipping level; surface area drop is associated with the capacity fade at the final unzipping level. Surface functional groups can result in low electrical conductivity and therefore cause capacity drop within sev...

In this study, amphiphilic poly(e-caprolactone)–pluronic–poly(e-caprolactone) (PCL–pluronic–PCL, PCFC) copolymers were synthesized by ring-opening copolymerization and then reacted with isophorone diisocyanate to form polyurethane (PU) copolymers. The molecular weight of the PU copolymers was measured by gel permeation chromatography, and the chemical structure was analyzed by 1H-nuclear magnetic resonance and Fourier transform infrared spectra. Then, the PU copolymers were processed into fibrous scaffolds by the electrospinning technology. The morphology, surface wettability, mechanical strength, and cytotoxicity of the obtained PU fibrous mats were investigated by scanning electron microscopy, water contact angle analysis, tensile test, and MTT analysis. The results show that the molecular weights of PCFC and PU copolymers significantly affected the physicochemical properties of electrospun PU nanofibers. Moreover, their good in vitro biocompatibility showed that the as-prepared PU nanofibers have great potential for applications in tissue engineering. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43643.