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1.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 49(1): 11-20, 2024 Jan 28.
Artículo en Inglés, Chino | MEDLINE | ID: mdl-38615161

RESUMEN

OBJECTIVES: Trigeminal neuralgia (TN) is a severe chronic neuropathic pain that mainly affects the distribution area of the trigeminal nerve with limited treating efficacy. There are numerous treatments for TN, but currently the main clinical approach is to suppress pain by carbamazepine (CBZ). Brain-derived neurotrophic factor (BDNF) is closely related to chronic pain. This study aims to determine the effects of CBZ treatment on BDNF expression in both the trigeminal ganglion (TG) and serum of TN via a chronic constriction injury of the infraorbital nerve (ION-CCI) rat model. METHODS: The ION-CCI models were established in male Sprague-Dawley rats and were randomly divided into a sham group, a TN group, a TN+low-dose CBZ treatment group (TN+20 mg/kg CBZ group), a TN+medium-dose CBZ treatment group (TN+40 mg/kg CBZ group), and a TN+high-dose CBZ treatment group (TN+80 mg/kg CBZ group). The mechanical pain threshold in each group of rats was measured regularly before and after surgery. The expressions of BDNF and tyrosine kinase receptor B (TrkB) mRNA in TGs of rats in different groups were determined by real-time PCR, and the expression of BDNF protein on neurons in TGs was observed by immunofluorescence. Western Blotting was used to detect the protein expression of BDNF, TrkB, extracellular regulated protein kinases (ERK), and phospho-extracellular regulated protein kinases (p-ERK) in TGs of rats in different groups. The expression of BDNF in the serum of rats in different groups was detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: The results of mechanical pain sensitivity showed that there was no significant difference in the mechanical pain threshold in the right facial sensory area of the experimental rats in each group before surgery (all P>0.05). From the 3rd day after operation, the mechanical pain threshold of rats in the TN group was significantly lower than that in the sham group (all P<0.01), and the mechanical pain threshold of rats in the TN+80 mg/kg CBZ group, the TN+40 mg/kg CBZ group, and the TN+20 CBZ mg/kg group was higher than that in the TN group (all P<0.05). The BDNF and TrkB mRNA and protein expressions in TGs of rats in the TN group were higher than those in the sham group (all P<0.05), and those in the TN+80 mg/kg CBZ group, the TN+40 mg/kg CBZ group, and the TN+20 mg/kg CBZ group were lower than the TN group (all P<0.05). The p-ERK levels in TG of rats in the TN+80 mg/kg CBZ group, the TN+40 mg/kg CBZ group, and the TN+20 mg/kg CBZ group were significantly decreased compared with the TN group (all P<0.05). The BDNF and neuron-specific nuclear protein (NeuN) were mainly co-expressed in neuron of TGs in the TN group and they were significantly higher than those in the sham group (all P<0.05). The co-labeled expressions of BDNF and NeuN in TGs of the TN+ 80 mg/kg CBZ group, the TN+40 mg/kg CBZ group, and the TN+20 mg/kg CBZ group were lower than those in the TN group (all P<0.05). The results of ELISA showed that the level of BDNF in the serum of the TN group was significantly higher than that in the sham group (P<0.05). The levels of BDNF in the TN+80 mg/kg CBZ group, the TN+40 mg/kg CBZ group, and the TN+20 mg/kg CBZ group were lower than those in the TN group (all P<0.05). Spearman correlation analysis showed that the BDNF level in serum was negatively correlated with mechanical pain threshold (r=-0.650, P<0.01). CONCLUSIONS: CBZ treatment can inhibit the expression of BDNF and TrkB in the TGs of TN rats, reduce the level of BDNF in serum of TN rats and the phosphorylation of ERK signaling pathway, so as to inhibit TN. The serum level of BDNF can be considered as an indicator for the diagnosis and prognosis of TN.


Asunto(s)
Carbamazepina , Dolor Crónico , Neuralgia del Trigémino , Animales , Masculino , Ratas , Factor Neurotrófico Derivado del Encéfalo/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/genética , Carbamazepina/farmacología , Proteínas Quinasas , Ratas Sprague-Dawley , ARN Mensajero , Ganglio del Trigémino/efectos de los fármacos , Neuralgia del Trigémino/tratamiento farmacológico
2.
Math Biosci ; 315: 108234, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31330136

RESUMEN

As photoautotrophic microorganisms, microalgae feature complex mechanisms of photosynthesis and light energy transfer and as such studying their intrinsic growth kinetics is fairly difficult. In this article, the quantum yield of photochemical reaction was introduced in a study of microalgal kinetics to establish an intrinsic kinetic model of photoautotrophic microalgal growth. The blue-green algae Synechococcus sp. PCC7942 was used to verify the kinetic model developed using chlorophyll fluorescence analysis and growth kinetics determination. Results indicate that the kinetic model can realistically reflect the light energy utilization efficiency of microalgae as well as their intrinsic growth kinetic characteristics. The model and method proposed in this article may be utilized in intrinsic kinetics studies of photoautotrophic microorganisms.


Asunto(s)
Procesos Autotróficos , Clorofila , Microalgas , Modelos Biológicos , Fotosíntesis , Cinética , Espectrometría de Fluorescencia
3.
Front Chem ; 6: 366, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30234097

RESUMEN

Carbonaceous anode materials are commonly utilized in the energy storage systems, while their unsatisfied electrochemical performances hardly meet the increasing requirements for advanced anode materials. Here, activated amorphous carbon (AAC) is synthesized by carbonizing renewable camellia pollen grains with naturally hierarchical structure, which not only maintains abundant micro- and mesopores with surprising specific surface area (660 m2 g-1), but also enlarges the interlayer spacing from 0.352 to 0.4 nm, effectively facilitating ions transport, intercalation, and adsorption. Benefiting from such unique characteristic, AAC exhibits 691.7 mAh g-1 after 1200 cycles at 2 A g-1, and achieves 459.7, 335.4, 288.7, 251.7, and 213.5 mAh g-1 at 0.1, 0.5, 1, 2, 5 A g-1 in rate response for lithium-ion batteries (LIBs). Additionally, reversible capacities of 324.8, 321.6, 312.1, 298.9, 282.3, 272.4 mAh g-1 at various rates of 0.1, 0.2, 0.5, 1, 2, 5 A g-1 are preserved for sodium-ion batteries (SIBs). The results reveal that the AAC anode derived from camellia pollen grains can display excellent cyclic life and superior rate performances, endowing the infinite potential to extend its applications in LIBs and SIBs.

4.
Front Chem ; 6: 78, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29755966

RESUMEN

Highly porous carbon with large surface areas is prepared using cotton as carbon sources which derived from discard cotton balls. Subsequently, the sulfur-nitrogen co-doped carbon was obtained by heat treatment the carbon in presence of thiourea and evaluated as Lithium-ion batteries anode. Benefiting from the S, N co-doping, the obtained S, N co-doped carbon exhibits excellent electrochemical performance. As a result, the as-prepared S, N co-doped carbon can deliver a high reversible capacity of 1,101.1 mA h g-1 after 150 cycles at 0.2 A g-1, and a high capacity of 531.2 mA h g-1 can be observed even after 5,000 cycles at 10.0 A g-1. Moreover, excellently rate capability also can be observed, a high capacity of 689 mA h g-1 can be obtained at 5.0 A g-1. This superior lithium storage performance of S, N co-doped carbon make it as a promising low-cost and sustainable anode for high performance lithium ion batteries.

5.
Angew Chem Int Ed Engl ; 57(1): 300-304, 2018 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-29149518

RESUMEN

A strategy to control the switch between a non-cycloaddition reaction and a cycloaddition reaction of enals, using N-heterocyclic carbene (NHC) catalyisis, has been developed. The new scalable protocol leads to γ-amino-acid esters bearing a tetrasubstituted stereocenter in good yields and high stereoselectivities by homo-Mannich reactions of enals and isatin-derived ketimines. By simply changing the N-ketimine substituent to an ortho-hydroxy phenyl group, the corresponding spirocyclic oxindolo-γ-lactams are obtained.

6.
Angew Chem Int Ed Engl ; 54(44): 13058-62, 2015 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-26335589

RESUMEN

Lithium-rich layered oxides are promising cathode materials for lithium-ion batteries and exhibit a high reversible capacity exceeding 250 mAh g(-1) . However, voltage fade is the major problem that needs to be overcome before they can find practical applications. Here, Li1.2 Mn0.54 Ni0.13 Co0.13 O2 (LLMO) oxides are subjected to nanoscale LiFePO4 (LFP) surface modification. The resulting materials combine the advantages of both bulk doping and surface coating as the LLMO crystal structure is stabilized through cationic doping, and the LLMO cathode materials are protected from corrosion induced by organic electrolytes. An LLMO cathode modified with 5 wt % LFP (LLMO-LFP5) demonstrated suppressed voltage fade and a discharge capacity of 282.8 mAh g(-1) at 0.1 C with a capacity retention of 98.1 % after 120 cycles. Moreover, the nanoscale LFP layers incorporated into the LLMO surfaces can effectively maintain the lithium-ion and charge transport channels, and the LLMO-LFP5 cathode demonstrated an excellent rate capacity.

7.
Chem Commun (Camb) ; 51(78): 14628-31, 2015 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-26287399

RESUMEN

An N-heterocyclic carbene catalyzed activation of α,ß-unsaturated N-acyltriazoles is described. The in situ generated α,ß-unsaturated acylazolium intermediates allowed an enantioselective formal [3+3] cycloaddition with 1,3-dicarbonyl compounds. The resulting dihydropyranones are formed in good to excellent yields and with high enantioselectivities.

8.
Synlett ; 26(11): 1465-1469, 2015 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-26752810

RESUMEN

An N-heterocyclic carbene catalyzed enantioselective [3+3] annulation of benzothiazolyl acetates with 2-bromoenals has been developed. The protocol provides a direct asymmetric synthesis of dihydro-1H-benzothiazolopyridinones in good to very good yields and medium ee values. In many cases, the virtually enantiopure heterocycles are available through a single recrystallization (99% ee).

9.
Chem Commun (Camb) ; 51(7): 1263-6, 2015 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-25476422

RESUMEN

An NHC-catalyzed regio- and stereoselective Mannich/lactamization domino reaction of N-(benzothiazolyl)imines with α-chloroaldehydes has been developed. This new protocol provides a facile approach for the asymmetric synthesis of benzothiazolo-pyrimidinones and a pyrrolo[1,2-a]indolone in moderate to good yields (34-78%) and excellent stereoselectivities (87-99% ee, up to >20 : 1 d.r.).


Asunto(s)
Iminas/química , Lactamas/química , Metano/análogos & derivados , Pirimidinonas/química , Tiazoles/química , Catálisis , Metano/química , Modelos Moleculares , Conformación Molecular , Estereoisomerismo , Especificidad por Sustrato
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