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1.
Xenotransplantation ; 22(4): 249-59, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26174875

RESUMEN

BACKGROUND: Hepatocyte transplantation is a promising therapy for acute liver failure. Cell therapy using xenogeneic sources has emerged as an alternative treatment for patients with organ failure due to the shortage of transplantable human organs. The purpose of this study was to improve the survival of mice with acute liver failure by transplanting encapsulated neonatal pig re-aggregated liver cells (NPRLC). METHODS: Liver injury was induced in C57/BL6 male mice by the injection of 600 mg/kg of acetaminophen. Xenogeneic liver cells were isolated from a neonatal pig and processed via re-aggregation and encapsulation to improve the efficiency of the xenogeneic liver cell transplantation. The neonatal pig liver showed abnormal lobule structure. Isolated cells were re-aggregated and intraperitoneally transplanted into acute liver failure mice models. RESULTS: Re-aggregated cells showed significantly enhanced viability and significantly greater synthesis of albumin and urea than cells cultured in monolayers. Further, we observed improved serum levels of ALT/AST, and the survival rate of mice with acute liver failure was improved by the intraperitoneal transplantation of encapsulated hepatocytes (48,000 equivalent (Eq) per mouse). CONCLUSIONS: This study shows that using encapsulated NPRLCs improves the efficacy of xenogeneic liver cell transplantation for the treatment of mice with acute liver failure. Therefore, this may be a good strategy for bridge therapy for the treatment of acute liver failure in humans.


Asunto(s)
Hepatocitos/trasplante , Fallo Hepático Agudo/terapia , Trasplante Heterólogo/métodos , Acetaminofén/toxicidad , Albúminas/biosíntesis , Animales , Animales Recién Nacidos , Agregación Celular , Supervivencia Celular , Células Cultivadas , Modelos Animales de Enfermedad , Supervivencia de Injerto , Hepatocitos/citología , Hepatocitos/metabolismo , Humanos , Fallo Hepático Agudo/inducido químicamente , Masculino , Ratones , Ratones Endogámicos C57BL , Esferoides Celulares/trasplante , Sus scrofa , Porcinos , Porcinos Enanos , Urea/metabolismo
2.
Nat Commun ; 15(1): 2991, 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38582753

RESUMEN

All-solid-state batteries using Si as the anode have shown promising performance without continual solid-electrolyte interface (SEI) growth. However, the first cycle irreversible capacity loss yields low initial Coulombic efficiency (ICE) of Si, limiting the energy density. To address this, we adopt a prelithiation strategy to increase ICE and conductivity of all-solid-state Si cells. A significant increase in ICE is observed for Li1Si anode paired with a lithium cobalt oxide (LCO) cathode. Additionally, a comparison with lithium nickel manganese cobalt oxide (NCM) reveals that performance improvements with Si prelithiation is only applicable for full cells dominated by high anode irreversibility. With this prelithiation strategy, 15% improvement in capacity retention is achieved after 1000 cycles compared to a pure Si. With Li1Si, a high areal capacity of up to 10 mAh cm-2 is attained using a dry-processed LCO cathode film, suggesting that the prelithiation method may be suitable for high-loading next-generation all-solid-state batteries.

3.
Inorg Chem ; 52(17): 9807-12, 2013 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-23941074

RESUMEN

Morphology-controlled MoS2 nanosheets were successfully synthesized with the aid of graphene/acid coexistence by a one-pot hydrothermal method. The ultrathin MoS2 nanosheets were self-assembled into a cockscomb-like structure with an exposed (100) facet on graphene sheets, which is in strong contrast to large aggregate MoS2 plates grown freely on graphene sheets without acetic acid. The ultrathin MoS2 nanosheets displayed excellent rate performance for Li storage (709 mAh·g(-1) capacity at 8320 mA·g(-1) discharging rate) and superior charge/discharge cyclability.

4.
Inorg Chem ; 48(17): 8271-5, 2009 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-19655712

RESUMEN

Synthesis time using microwave irradiation was varied to elucidate the electrochemical degradation mechanism of LiFePO(4) related to the evolution of Fe(2)P. When the amount of Fe(2)P was above a critical level, LiFePO(4) tended to change into an insulating phase, Li(4)P(2)O(7). The correlation between structural analysis and electrochemical analysis attributed the initial degradation of LiFePO(4) to the low electronic conductivity of Li(4)P(2)O(7), whereas the deficiency of P and O evolved by Li(4)P(2)O(7) resulted in the cyclic degradation of LiFePO(4). This kind of correlation between structure and electrochemical performance in intercalation materials will significantly contribute to an explanation of their degradation mechanism for their application.

5.
Adv Mater ; 30(43): e1804142, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30199111

RESUMEN

Solid-state electrolyte materials are attractive options for meeting the safety and performance needs of advanced lithium-based rechargeable battery technologies because of their improved mechanical and thermal stability compared to liquid electrolytes. However, there is typically a tradeoff between mechanical and electrochemical performance. Here an elastic Li-ion conductor with dual covalent and dynamic hydrogen bonding crosslinks is described to provide high mechanical resilience without sacrificing the room-temperature ionic conductivity. A solid-state lithium-metal/LiFePO4 cell with this resilient electrolyte can operate at room temperature with a high cathode capacity of 152 mAh g-1 for 300 cycles and can maintain operation even after being subjected to intense mechanical impact testing. This new dual crosslinking design provides robust mechanical properties while maintaining ionic conductivity similar to state-of-the-art polymer-based electrolytes. This approach opens a route toward stable, high-performance operation of solid-state batteries even under extreme abuse.

6.
Adv Mater ; 29(1)2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28042889

RESUMEN

Energy-storage technologies such as lithium-ion batteries and supercapacitors have become fundamental building blocks in modern society. Recently, the emerging direction toward the ever-growing market of flexible and wearable electronics has nourished progress in building multifunctional energy-storage systems that can be bent, folded, crumpled, and stretched while maintaining their electrochemical functions under deformation. Here, recent progress and well-developed strategies in research designed to accomplish flexible and stretchable lithium-ion batteries and supercapacitors are reviewed. The challenges of developing novel materials and configurations with tailored features, and in designing simple and large-scaled manufacturing methods that can be widely utilized are considered. Furthermore, the perspectives and opportunities for this emerging field of materials science and engineering are also discussed.

7.
Adv Sci (Weinh) ; 4(9): 1700128, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28932676

RESUMEN

Fast lithium ion and electron transport inside electrode materials are essential to realize its superb electrochemical performances for lithium rechargeable batteries. Herein, a distinctive structure of cathode material is proposed, which can simultaneously satisfy these requirements. Nanosized Li3V2(PO4)3 (LVP) particles can be successfully grown up on the carbon nanofiber via electrospinning method followed by a controlled heat-treatment. Herein, LVP particles are anchored onto the surface of carbon nanofiber, and with this growing process, the size of LVP particles as well as the thickness of carbon nanofiber can be regulated together. The morphological features of this composite structure enable not only direct contact between electrolytes and LVP particles that can enhance lithium ion diffusivity, but also fast electron transport through 1D carbon network along nanofibers simultaneously. Finally, it is demonstrated that this unique structure is an ideal one to realize high electron transport and ion diffusivity together, which are essential for enhancing the electrochemical performances of electrode materials.

8.
J Phys Chem B ; 109(18): 8983-6, 2005 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-16852070

RESUMEN

Hydrogen storage properties of mutiwalled carbon nanotubes (MWCNTs) with Ni nanoparticles were investigated. The metal nanoparticles were dispersed on MWCNTs surfaces using an incipient wetness impregnation procedure. Ni catalysts have been known to effectively dissociate hydrogen molecules in gas phase, providing atomic hydrogen possible to form chemical bonding with the surfaces of MWCNTs. Hydrogen desorption spectra of MWCNTs with 6 wt % of Ni nanoparticles showed that approximately 2.8 wt % hydrogen was released in the range of 340-520 K. In Kissinger's plot to evaluate the nature of interaction between hydrogen and MWCNTs with Ni nanoparticles, the hydrogen desorption activation energy was measured to be as high as approximately 31 kJ/mol.H(2), which is much higher than the estimates of pristine SWNTs. C-H(n)() stretching vibrations after hydrogenation in FTIR further supported that hydrogen molecules were dissociated when bound to the surfaces of MWCNTs. During cyclic hydrogen absorption/desorption, there was observed no significant decay in hydrogen desorption amount. The hydrogen chemisorption process facilitated by Ni nanopaticles could be suggested as an effective reversible hydrogen storage method.

9.
Chem Commun (Camb) ; 50(20): 2589-91, 2014 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-24463739

RESUMEN

We report a synthetic scheme for preparing a SnO2-Sn-carbon triad inverse opal porous material using the controlled sintering of Sn precursor-infiltrated polystyrene (PS) nanobead films. Because the uniform PS nanobead film, which can be converted into carbon via a sintering step, uptakes the precursor solution, the carbon can be uniformly distributed throughout the Sn-based anode material. Moreover, the partial carbonization of the PS nanobeads under a controlled Ar/oxygen environment not only produces a composite material with an inverse opal-like porous nanostructure but also converts the Sn precursor/PS into a SnO2-Sn-C triad electrode.

10.
ChemSusChem ; 7(9): 2489-95, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25066369

RESUMEN

A 2H-MoS2 (H=hexagonal) ultrathin nanomesh with high defect generation and large porosity is demonstrated to improving electrochemical performance, including in lithium-ion batteries (LIBs) and the hydrogen evolution reaction (HER), with the aid of a 3D reduced graphene oxide (RGO) scaffold as fast electron and ion channels. The 3D defect-rich MoS2 nanomesh/RGO foam (Dr-MoS2 Nm/RGO) can be easily obtained through a one-pot cobalt acetate/graphene oxide (GO) co-assisted hydrothermal reaction, in which GO, cobalt and acetate ions are co-morphology-controlling agents and defect inducers. As an anode material for LIBs, Dr-MoS2 Nm/RGO has only a 9% capacity decay at a 10 C discharge rate versus 0.2 C with stable cyclability at the optimized composition (5 wt% RGO to MoS2 and 2 mol% Co to Mo), and significantly achieves 810 mA h g(-1) at a high current density of 9.46 A g(-1) over at least 150 cycles. Moreover, Dr-MoS2 Nm/RGO exhibits superior activity for the HER with an overpotential as low as 80 mV and a Tafel slope of about 36 mV per decade. In contrast to the MoS2 nanosheet/RGO (MoS2 Ns/RGO), which is synthesized in the absence of cobalt ions, Dr-MoS2 Nm/RGO provides high interconnectivity for efficient lithium-ion transport, and rich defects as electrochemically active sites. DFT is used to prove the existence of rich defects due to anion replacement to become a Co-Mo-S atomic structure, releasing inert basal planes to active sites.


Asunto(s)
Disulfuros/química , Suministros de Energía Eléctrica , Hidrógeno/química , Molibdeno/química , Electroquímica , Modelos Moleculares , Conformación Molecular , Porosidad
11.
Chem Commun (Camb) ; 49(23): 2326-8, 2013 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-23403469

RESUMEN

Herein, we first report a facile synthetic route for preparing micron-sized particles comprising TiO(2)-B nanotubes, namely, skein shaped TiO(2)-B nanotube cluster particles with an ultra high surface area of 257 m(2) g(-1). The galvanostatic charge-discharge test showed that the hierarchical micron-sized particles composed of TiO(2)-B nanotubes with approximately 10 nm in diameter exhibited outstanding rate capability as well as high specific capacity.

12.
Ann Coloproctol ; 29(5): 192-7, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24278857

RESUMEN

PURPOSE: The aim of this study is to evaluate the efficacy and the safety of additional 4-week chemotherapy with capecitabine during the resting periods after a 6-week neoadjuvant chemoradiotherapy (NCRT) in patients with locally advanced rectal cancer. METHODS: Radiotherapy was delivered to the whole pelvis at a total dose of 50.4 Gy for 6 weeks. Oral capecitabine was administered at a dose of 825 mg/m(2) twice daily for 10 weeks. Surgery was performed 2-4 weeks following the completion of chemotherapy. RESULTS: Between January 2010 and September 2011, 44 patients were enrolled. Forty-three patients underwent surgery, and 41 patients completed the scheduled treatment. Pathologic complete remission (pCR) was noted in 9 patients (20.9%). T down-staging and N down-staging were observed in 32 patients (74.4%) and 33 patients (76.7%), respectively. Grade 3 to 5 toxicity was noted in 5 patients (11.4%). The pCR rate was similar with the pCR rates obtained after conventional NCRT at our institute and at other institutes. CONCLUSION: This study showed that additional 4-week chemotherapy with capecitabine during the resting periods after 6-week NCRT was safe, but it was no more effective than conventional NCRT.

13.
Chem Commun (Camb) ; 48(4): 516-8, 2012 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-22124307

RESUMEN

A carbon-free Li(4)Ti(5)O(12) electrode has shown excellent electrochemical performance without any effort to enhance the electrical conductivity. Partial reduction of Ti(4+) and a metallic Li(7)Ti(5)O(12) phase are suggested to be possible origins of the exceptional behavior.

14.
J Korean Surg Soc ; 83(5): 281-7, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23166887

RESUMEN

PURPOSE: The safety and the feasibility of performing laparoscopic surgery for rectal cancer after preoperative chemoradiotherapy (CRT) have not yet been established. Thus, the aim of this study was to evaluate the efficacy and the safety of laparoscopic rectal cancer surgery performed after preoperative CRT. METHODS: We enrolled 124 consecutive patients who underwent laparoscopic surgery for rectal cancer. Of these patients, 56 received preoperative CRT (CRT group), whereas 68 did not (non-CRT group). The patients who were found to have distant metastasis and open conversion during surgery were excluded. The clinicopathologic parameters were evaluated and the short-term outcomes were compared between the CRT and non-CRT groups. RESULTS: The mean operation time was longer in the CRT group (294 minutes; range, 140 to 485 minutes; P = 0.004). In the non-CRT group, the tumor sizes were larger (mean, 4.0 cm; range, 1.2 to 8.0 cm; P < 0.001) and more lymph nodes were harvested (mean, 12.9; range, 0 to 35; P < 0.001). However, there was no significant difference between the two groups in time to first bowel movement, tolerance of a soft diet, length of hospital stay, and postoperative complication rate. CONCLUSION: Performing laparoscopic surgery for rectal cancer after preoperative CRT may be safe and feasible if performed by a highly skilled laparoscopic surgeon. Randomized controlled trials and long-term follow-up studies are necessary to support our results.

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