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1.
Small ; 15(16): e1900269, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30848874

RESUMO

In this study, self-synthesized lithium trifluoro(perfluoro-tert-butyloxyl)borate (LiTFPFB) is combined with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to formulate a novel 1 m dual-salt electrolyte, which contains lithium difluorophosphate (LiPO2 F2 ) additive and dominant carbonate solvents with low melting point and high boiling point. The addition of LiPO2 F2 into this novel dual-salt electrolyte dramatically improves cycleability and rate capability of a LiNi0.5 Mn0.3 Co0.2 O2 /Li (NMC/Li) battery, ranging from -40 to 90 °C. The NMC/Li batteries adopt a Li-metal anode with low thickness of 100 µm (even 50 µm) and a moderately high cathode mass loading level of 10 mg cm-2 . For the first time, this paper provides valuable perspectives for developing practical lithium-metal batteries over a wide temperature range.

2.
Front Chem ; 10: 986541, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36204151

RESUMO

The commercialization of sodium-ion batteries has been hampered by the anode's performance. Carbon-based anodes have always had great application prospects, but traditional graphite anodes have great application limitations due to the inability of reversible insertion/de-insertion of sodium ions in them, while hard carbon materials have the high theoretical capacity, low reaction potential has received extensive attention in recent years. Nevertheless, the low first cycle Coulomb efficiency and rapid capacity decline of hard carbon materials limited its application. SEI has always played a crucial role in the electrochemical process. By controlling the formation of SEI, researchers have increased the efficiency of sodium-ion battery anodes, although the composition of SEI and how it evolved are still unknown. This paper briefly summarizes the research progress of hard carbon anode surface SEI in sodium-ion batteries in recent years. From the perspectives of characterization methods, structural composition, and regulation strategies is reviewed, and the future development directions of these three directions are suggested. The reference opinions are provided for the reference researchers.

3.
Bioorg Med Chem Lett ; 21(8): 2533-6, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21392987

RESUMO

A new class of benzoxaborole ß-lactamase inhibitors were designed and synthesized. 6-Aryloxy benzoxaborole 22 inhibited AmpC P99 and CMY-2 with K(i) values in the low nanomolar range. Compound 22 restored antibacterial activity of ceftazidime against Enterobacter cloacae P99 expressing AmpC, a class C ß-lactamase enzyme. The SAR around the arylbenzoxaboroles, which included the influence of linker and substitutions was also established.


Assuntos
Antibacterianos/síntese química , Benzoxazóis/química , Compostos de Boro/química , Inibidores Enzimáticos/síntese química , Pirazinas/síntese química , Inibidores de beta-Lactamases , Antibacterianos/química , Antibacterianos/farmacologia , Compostos de Boro/síntese química , Compostos de Boro/farmacologia , Enterobacter cloacae/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Testes de Sensibilidade Microbiana , Pirazinas/química , Pirazinas/farmacologia , Relação Estrutura-Atividade , beta-Lactamases/metabolismo
4.
ACS Appl Mater Interfaces ; 13(16): 18733-18742, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33861562

RESUMO

A dual substitution strategy is introduced to Co-free layered material LiNi0.5Mn0.5O2 by partially replacing Li and Ni with Na and Al, respectively, to achieve a superior cathode material for lithium ion batteries. Na+ ion functions as a "pillar" and a " cationic barrier" in the lithium layer while Al3+ ion plays an auxiliary role in stabilizing structure and lattice oxygen to improve the electrochemical performance and safety. The stability of lattice oxygen comes from the binding energy between the Ni and O, which is larger due to higher valences of Ni ions, along with a stronger Al-O bond in the crystal structure and the "cationic barrier" effect of Na+ ion at the high-charge. The more stable lattice oxygen reduces the cation disorder in cycling, and Na+ in the Li layer squeezes the pathway of the transition metal from the LiM2 (M = metal) layer to the Li layer, stabilizing the layered crystal structure by inhibiting the electrochemical-driven cation disorder. Moreover, the cathode with Na-Al dual-substitution displays a smaller volume change, yielding a more stable structure. This study unravels the influence of Na-Al dual-substitution on the discharge capacity, midpoint potential, and cyclic stability of Co-free layered cathode materials, which is crucial for the development of lithium ion batteries.

5.
Int. j. morphol ; 42(1): 216-224, feb. 2024. ilus
Artigo em Inglês | LILACS | ID: biblio-1528818

RESUMO

SUMMARY: Senile osteoporosis is mainly caused by reduced osteoblast differentiation and has become the leading cause of fractures in the elderly worldwide. Natural organics are emerging as a potential option for the prevention and treatment of osteoporosis. This study was designed to study the effect of resveratrol on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in osteoporosis mice. A mouse model of osteoporosis was established by subcutaneous injection of dexamethasone and treated with resveratrol administered by gavage. In vivo and in vitro, we used western blot to detect protein expression, and evaluated osteogenic differentiation of BMSCs by detecting the expression of osteogenic differentiation related proteins, calcium deposition, ALP activity and osteocalcin content. Resveratrol treatment significantly increased the body weight of mice, the level of serum Ca2+, 25(OH)D and osteocalcin, ration of bone weight, bone volume/total volume, trabecular thickness, trabecular number, trabecular spacing and cortical thickness in osteoporosis mice. In BMSCs of osteoporosis mice, resveratrol treatment significantly increased the expression of Runx2, osterix (OSX) and osteocalcin (OCN) protein, the level of calcium deposition, ALP activity and osteocalcin content. In addition, resveratrol treatment also significantly increased the expression of SIRT1, p-PI3K / PI3K and p-AKT / AKT in BMSCs of osteoporosis mice. In vitro, resveratrol increased the expression of SIRT1, p-PI3K / PI3K and p-AKT / AKT, Runx2, OSX and OCN protein, the level of calcium deposition, ALP activity and osteocalcin content in BMSCs in a concentration-dependent manner, while SIRT1 knockdown significantly reversed the effect of resveratrol. Resveratrol can attenuate osteoporosis by promoting osteogenic differentiation of bone marrow mesenchymal stem cells, and the mechanism may be related to the regulation of SIRT1/PI3K/AKT pathway.


La osteoporosis senil es causada principalmente por una diferenciación reducida de osteoblastos y se ha convertido en la principal causa de fracturas en las personas mayores en todo el mundo. Los productos orgánicos naturales están surgiendo como una opción potencial para la prevención y el tratamiento de la osteoporosis. Este estudio fue diseñado para estudiar el efecto del resveratrol en la diferenciación osteogénica de las células madre mesenquimales de la médula ósea (BMSC) en ratones con osteoporosis. Se estableció un modelo de osteoporosis en ratones mediante inyección subcutánea de dexametasona y se trató con resveratrol administrado por sonda. In vivo e in vitro, utilizamos Western blot para detectar la expresión de proteínas y evaluamos la diferenciación osteogénica de BMSC detectando la expresión de proteínas relacionadas con la diferenciación osteogénica, la deposición de calcio, la actividad de ALP y el contenido de osteocalcina. El tratamiento con resveratrol aumentó significativamente el peso corporal de los ratones, el nivel sérico de Ca2+, 25(OH)D y osteocalcina, la proporción de peso óseo, el volumen óseo/ volumen total, el espesor trabecular, el número trabecular, el espaciado trabecular y el espesor cortical en ratones con osteoporosis. En BMSC de ratones con osteoporosis, el tratamiento con resveratrol aumentó significativamente la expresión de las proteínas Runx2, osterix (OSX) y osteocalcina (OCN), el nivel de deposición de calcio, la actividad de ALP y el contenido de osteocalcina. Además, el tratamiento con resveratrol también aumentó significativamente la expresión de SIRT1, p-PI3K/PI3K y p-AKT/AKT en BMSC de ratones con osteoporosis. In vitro, el resveratrol aumentó la expresión de las proteínas SIRT1, p-PI3K/PI3K y p- AKT/AKT, Runx2, OSX y OCN, el nivel de deposición de calcio, la actividad de ALP y el contenido de osteocalcina en BMSC de manera dependiente de la concentración, mientras que La caída de SIRT1 revirtió significativamente el efecto del resveratrol. El resveratrol puede atenuar la osteoporosis al promover la diferenciación osteogénica de las células madre mesenquimales de la médula ósea, y el mecanismo puede estar relacionado con la regulación de la vía SIRT1/PI3K/AKT.


Assuntos
Animais , Masculino , Camundongos , Osteoporose/tratamento farmacológico , Resveratrol/administração & dosagem , Osteogênese/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Western Blotting , Modelos Animais de Doenças , Sirtuína 1 , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Resveratrol/farmacologia , Camundongos Endogâmicos C57BL
7.
World J Gastroenterol ; 11(22): 3339-45, 2005 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-15948236

RESUMO

AIM: To investigate the cytotoxicity of the cytokine-induced killer (CIK) cells from the post-operation patients with primary hepatocellular carcinoma (HCC) to multidrug-resistant (MDR) cell of HCC both in vitro and in vivo. METHODS: A drug-resistant cell line was established by culturing human HCC cell line Bel-7402 in complete RPMI 1640 medium with increasing concentrations of adriamycin from 10 to 2,000 nmol/L. CIK cells were obtained by inducing the peripheral blood mononuclear cells with rhIFN-gamma, monoclonal anti-CD3 antibody, rhIL-1alpha as well as rhIL-2, which were added into the culture. To detect the cytotoxicity of the CIK cells from HCC patients, the Bel-7402/R was taken as target (T) cells and CIK cells as effect (E) cells. Cytotoxic test was performed and measured by MTT. As to in vivo test, CIK cells were transfused into patients with HCC. The tumor specimens of the patients were obtained and immunohistochemistry was carried out to detect CD3, CD45, CD45RO as well as CD68. RESULTS: A MDR 1 HCC cell line Bel-7402/R was established. Its MDR1 mRNA overexpressed which was shown by RT-PCR; the P-glycoprotein expression increased from 1.32% of parent cells to 54%. CIK cells expanded vigorously by more than 70-fold and the CD3+CD56+ increased by more than 600-fold after 3-wk incubation on average. The cytotoxicity of CIK from HCC patients to Bel-7402/R was about 50% and to L-02 below 10% (t = 8.87, P<0.01), the same as that of CIK from normal individuals. Each of the 17 patients received 1-5 x 10(10) of CIK cell transfusion. No side effects were observed. After CIK treatment, the tumor tissue nodules formed and a large amount of lymphocytes infiltrated in the liver cancer tissue and CD3, CD45, CD45RO, and CD68 increased greatly which was shown by immunohistochemistry. CONCLUSION: A stable MDR1 HCC cell line has been established which could recover from liquid nitrogen and CIK from HCC patients has strong cytotoxicity to MDR HCC cell. CIK adoptive immunotherapy is safe and has no side effects. Receivers improved their immunity to tumor evidently. CIK treatment may be a better choice for HCC patients after operation to prevent the recurrence, especially when tumors have developed drug resistance.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Carcinoma Hepatocelular/imunologia , Células Matadoras Naturais/imunologia , Neoplasias Hepáticas/imunologia , Transferência Adotiva , Adulto , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/imunologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade
8.
Cancer Biother Radiopharm ; 19(5): 627-40, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15650456

RESUMO

The potential targeting of therapeutic bisphosphonate conjugates to bone metastatic lesions was evaluated in vivo in mice. A bisphosphonate conjugate with 5-fluorouracil was synthesized as a potential chemotherapy agent, and a bisphosphonate conjugate with diethylenetriaminepentaacetic acid (DTPA) was prepared as a potential carrier of cytotoxic radionuclides. The compounds are hypothesized to be able to deliver either high doses of radiation or a high concentration of chemotherapy agents at sites of increased osteoclastic activity in patients with bony metastases while exhibiting minimal toxicity to normal tissues. Tissue distribution studies with the 99mTc-labeled bisphosphonate conjugates with DTPA and 5-fluorouracil showed rapid blood clearance and excretion of unbound activity, clearance from most tissues, and substantial retention of the bisphosphonates in bone. For the DTPA conjugate, activity in the bone represents 13.6% of the total injected dose at 8 hours following injection, representing 54.3% of the total whole-body activity at this time period. Under the same conditions, the 5-fluorouracil conjugate showed a 17.1% bone uptake at 60.2% of the whole-body activity. This normal bone uptake predicts that high concentrations of conjugates are expected to be achieved at sites of bone metastatic disease. Chemotherapy and radiotherapy studies with these compounds in animal models of metastatic bone cancer are underway.


Assuntos
Neoplasias Ósseas/tratamento farmacológico , Difosfonatos/química , Difosfonatos/uso terapêutico , Animais , Antimetabólitos Antineoplásicos/farmacologia , Feminino , Fluoruracila/farmacologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Modelos Químicos , Metástase Neoplásica , Transplante de Neoplasias , Neoplasias Experimentais , Ácido Pentético/farmacologia , Medronato de Tecnécio Tc 99m/farmacologia , Pentetato de Tecnécio Tc 99m/farmacologia , Fatores de Tempo , Distribuição Tecidual
9.
Pest Manag Sci ; 68(4): 618-28, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22045547

RESUMO

BACKGROUND: The herbicide sulfonylurea (SU) belongs to one of the most important class of herbicides worldwide. It is well known for its ecofriendly, extreme low toxicity towards mammals and ultralow dosage application. The original inventor, G Levitt, set out structure-activity relationship (SAR) guidelines for SU structural design to attain superhigh bioactivity. A new approach to SU molecular design has been developed. RESULTS: After the analysis of scores of SU products by X-ray diffraction methodology and after greenhouse herbicidal screening of 900 novel SU structures synthesised in the authors' laboratory, it was found that several SU structures containing a monosubstituted pyrimidine moiety retain excellent herbicidal characteristics, which has led to partial revision of the Levitt guidelines. CONCLUSIONS: Among the novel SU molecules, monosulfuron and monosulfuron-ester have been developed into two new herbicides that have been officially approved for field application and applied in millet and wheat fields in China. A systematic structural study of the new substrate-target complex and the relative mode of action in comparison with conventional SU has been carried out. A new mode of action has been postulated.


Assuntos
Herbicidas/química , Herbicidas/farmacologia , Compostos de Sulfonilureia/química , Compostos de Sulfonilureia/farmacologia , Brassica/efeitos dos fármacos , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Difração de Raios X
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