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1.
Adv Mater ; 36(25): e2400810, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38569213

RESUMEN

The catalytic activation of the Li-S reaction is fundamental to maximize the capacity and stability of Li-S batteries (LSBs). Current research on Li-S catalysts mainly focuses on optimizing the energy levels to promote adsorption and catalytic conversion, while frequently overlooking the electronic spin state influence on charge transfer and orbital interactions. Here, hollow NiS2/NiSe2 heterostructures encapsulated in a nitrogen-doped carbon matrix (NiS2/NiSe2@NC) are synthesized and used as a catalytic additive in sulfur cathodes. The NiS2/NiSe2 heterostructure promotes the spin splitting of the 3d orbital, driving the Ni3+ transformation from low to high spin. This high spin configuration raises the electronic energy level and activates the electronic state. This accelerates the charge transfer and optimizes the adsorption energy, lowering the reaction energy barrier of the polysulfides conversion. Benefiting from these characteristics, LSBs based on NiS2/NiSe2@NC/S cathodes exhibit high initial capacity (1458 mAh·g⁻1 at 0.1C), excellent rate capability (572 mAh·g⁻1 at 5C), and stable cycling with an average capacity decay rate of only 0.025% per cycle at 1C during 500 cycles. Even at high sulfur loadings (6.2 mg·cm⁻2), high initial capacities of 1173 mAh·g⁻1 (7.27 mAh·cm⁻2) are measured at 0.1C, and 1058 mAh·g⁻1 is retained after 300 cycles.

2.
ACS Appl Mater Interfaces ; 16(6): 6948-6957, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38305160

RESUMEN

Electrocatalytic hydrogenation (ECH) approaches under ambient temperature and pressure offer significant potential advantages over thermal hydrogenation processes but require highly active and efficient hydrogenation electrocatalysts. The performance of such hydrogenation electrocatalysts strongly depends not only on the active phase but also on the architecture and surface chemistry of the support material. Herein, Pd nanoparticles supported on a nickel metal-organic framework (MOF), Ni-MOF-74, are prepared, and their activity toward the ECH of benzaldehyde (BZH) in a 3 M acetate (pH 5.2) aqueous electrolyte is explored. An outstanding ECH rate up to 283 µmol cm-2 h-1 with a Faradaic efficiency (FE) of 76% is reached. Besides, higher FEs of up to 96% are achieved using a step-function voltage. Materials Studio and density functional theory calculations show these outstanding performances to be associated with the Ni-MOF support that promotes H-bond formation, facilitates water desorption, and induces favorable tilted BZH adsorption on the surface of the Pd nanoparticles. In this configuration, BZH is bonded to the Pd surface by the carbonyl group rather than through the aromatic ring, thus reducing the energy barriers of the elemental reaction steps and increasing the overall reaction efficiency.

3.
Adv Mater ; 36(1): e2305128, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37555532

RESUMEN

Low-cost, safe, and environmental-friendly rechargeable aqueous zinc-ion batteries (ZIBs) are promising as next-generation energy storage devices for wearable electronics among other applications. However, sluggish ionic transport kinetics and the unstable electrode structure during ionic insertion/extraction hamper their deployment. Herein, a new cathode material based on a layered metal chalcogenide (LMC), bismuth telluride (Bi2 Te3 ), coated with polypyrrole (PPy) is proposed. Taking advantage of the PPy coating, the Bi2 Te3 @PPy composite presents strong ionic absorption affinity, high oxidation resistance, and high structural stability. The ZIBs based on Bi2 Te3 @PPy cathodes exhibit high capacities and ultra-long lifespans of over 5000 cycles. They also present outstanding stability even under bending. In addition, here the reaction mechanism is analyzed using in situ X-ray diffraction, X-ray photoelectron spectroscopy, and computational tools and it is demonstrated that, in the aqueous system, Zn2+ is not inserted into the cathode as previously assumed. In contrast, proton charge storage dominates the process. Overall, this work not only shows the great potential of LMCs as ZIB cathode materials and the advantages of PPy coating, but also clarifies the charge/discharge mechanism in rechargeable ZIBs based on LMCs.

4.
J Am Chem Soc ; 145(34): 18992-19004, 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37603793

RESUMEN

An AB2X4 spinel structure, with tetrahedral A and octahedral B sites, is a paradigmatic class of catalysts with several possible geometric configurations and numerous applications, including polysulfide conversion in metal-sulfur batteries. Nonetheless, the influence of the geometric configuration and composition on the mechanisms of catalysis and the precise manner in which spinel catalysts facilitate the conversion of polysulfides remain unknown. To enable controlled exposure of single active configurations, herein, Cotd2+ and Cooh3+ in Co3O4 catalysts for sodium polysulfide conversion are in large part replaced by Fetd2+ and Feoh3+, respectively, generating FeCo2O4 and CoFe2O4. Through an examination of electrochemical activation energies, the characterization of symmetric cells, and theoretical calculations, we determine that Cooh3+ serves as the active site for the breaking of S-S bonds, while Cotd2+ functions as the active site for the formation of S-Na bonds. The current study underlines the subtle relationship between activity and geometric configurations of spinel catalysts, providing unique insights for the rational development of improved catalysts by optimizing their atomic geometric configuration.

5.
Angew Chem Int Ed Engl ; 61(49): e202211570, 2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-36216781

RESUMEN

Lithium-sulfur batteries (LSBs) are still limited by the shuttle of lithium polysulfides (LiPS) and the slow Li-S reaction. Herein, we demonstrate that when using cobalt sulfide as a catalytic additive, an external magnetic field generated by a permanent magnet can significantly improve the LiPS adsorption ability and the Li-S reaction kinetics. More specifically, the results show both experimentally and theoretically how an electron spin polarization of Co ions reduces electron repulsion and enhances the degree of orbital hybridization, thus resulting in LSBs with unprecedented performance and stability. Under an external magnetic field, LSBs with 0.0084 % per cycle decay rate at 2 C during 8150 cycles are produced. Overall, this work not only demonstrates an effective strategy to promote LiPS adsorption and electrochemical conversion in LSBs at no additional energy cost but also enriches the application of the spin effect in the electrocatalysis fields.

6.
ACS Appl Mater Interfaces ; 14(33): 37771-37781, 2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-35960183

RESUMEN

Active metal ions often show a strong cutting effect on the chemical bonds during high-temperature thermal processes. Herein, a one-pot metal ion cutting-assisted method was adopted to design defect-rich MoS2-x nanosheet (NS)/ZnS nanoparticle (NP) heterojunction composites on carbon nanofiber skeletons (CNF@MoS2-x/ZnS) via a simple Ar-ambience annealing. Results show that Zn2+ ions capture S2- ions from MoS2 and form into ZnS NPs, and the MoS2 NSs lose S2- ions and become MoS2-x ones. As sulfur hosts for lithium-sulfur batteries (LSBs), the CNF@MoS2-x/ZnS-S cathodes deliver a high reversible capacity of 1233 mA h g-1 at 0.1 C and keep 944 mA h g-1 at 3 C. Moreover, the cathodes also show an extremely low decay rate of 0.012% for 900 cycles at 2 C. Series of analysis indicate that the MoS2-x NSs significantly improve the chemisorption and catalyze the kinetic process of redox reactions of lithium polysulfides, and the heterojunctions between MoS2-x NSs and ZnS NPs further accelerate the transport of electrons and the diffusion of Li+ ions. Besides, the CNF@MoS2-x/ZnS-S LSBs also show an ultralow self-discharge rate of 1.1% in voltage. This research would give some new insights for the design of defect-rich electrode materials for high-performance energy storage devices.

7.
Schizophrenia (Heidelb) ; 8(1): 55, 2022 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-35853913

RESUMEN

High-risk populations of schizophrenia can be mainly identified as genetic high-risk based on putative endophenotypes or ultra-high-risk (UHR) based on clinically manifested symptoms. Previous studies have consistently shown brain structural abnormalities in both genetic high-risk and UHR individuals. In this study, we aimed to disentangle the convergent and divergent pattern of gray matter alterations between UHR and unaffected first-degree relatives from genetic high-risk individuals. We used structural MRI scans and voxel-based morphometry method to examine gray matter volume (GMV) differences among 23 UHR subjects meeting the Structured Interview for Prodromal Syndromes (SIPS) criteria, 18 unaffected first-degree relatives (UFDR), 26 first-episode schizophrenia patients (FES) and 54 healthy controls (CN). We found that a number of brain regions exhibited a monotonically decreasing trend of GMV from CN to UFDR to UHR to FES. Compared with CN, the UHR subjects showed significant decreases of GMV similar to the patients in the inferior temporal gyrus, fusiform gyrus, middle occipital gyrus, insula, and limbic regions. Moreover, the UHR transformed subgroup had significantly lower GMV than UHR non-transformed subgroup in the right inferior temporal/fusiform gyrus. On the other hand, the UFDR subjects only showed significant GMV decreases in the inferior temporal gyrus and fusiform. Moreover, we found GMV in the occipital lobe was negatively correlated with the UHR subjects' composite positive symptom of SIPS, and GMV in the cerebellum was positively correlated with FES subjects' symptom severity. Our results suggest that GMV deficits and regional dysfunction are evident prior to the onset of psychosis and are more prominent in the UHR than the UFDR individuals.

8.
Huan Jing Ke Xue ; 43(4): 2007-2017, 2022 Apr 08.
Artículo en Chino | MEDLINE | ID: mdl-35393824

RESUMEN

Bacteria play a key role in the removal of pollutants and nutrients in constructed wetlands. DNA and RNA high-throughput sequencing was used to investigate the diversity, metabolic activity, and function of bacteria in aquaculture wastewater and in constructed wetlands treated by different aeration levels. The results revealed that:① a total of 4042 operational taxonomic units (OTUs) were detected in aquaculture wastewater and constructed wetland treatment groups. α-Proteobacteria, γ-Proteobacteria, and Bacteroidia were the most diverse groups, and the constructed wetlands aeration treatment increased the bacterial diversity to a variable extent; ② α-Proteobacteria, γ-Proteobacteria, Bacteroidia, and Actinobacteria were the dominant groups both in the DNA and RNA sequencing results, and the metabolic activities of these four groups were significantly affected by the concentration of total nitrogen (TN) and nitrate nitrogen (NO3--N) in our study. ③ According to the FAPROTAX database, 56 bacterial functional groups were detected in our study, mainly including:chemoheterotrophy, aerobic chemoheterotrophy, fermentation, intracellular parasites, dark hydrogen oxidation, phototrophy, photoheterotrophy, and nitrate reduction. Functions related to the nitrogen cycle were observed in the results of function annotation, suggesting the important role of bacterial communities in the removal of nitrogen nutrients in constructed wetlands. These results will improve the understanding of bacterial community structures and functions during nutrient removal in aerated constructed wetlands.


Asunto(s)
Aguas Residuales , Humedales , Bacterias/genética , Nitratos , Nitrógeno/análisis , Eliminación de Residuos Líquidos/métodos
9.
J Colloid Interface Sci ; 608(Pt 1): 459-469, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34626989

RESUMEN

Carbon nanotubes (CNTs) are often used to settle down the sluggish reaction kinetics in lithium-sulfur batteries (LSBs). However, the self-aggregation of CNTs often makes them fail to effectively inhibit the shuttling effect of soluble lithium polysulfide (LiPS) intermediates. Herein, a type of ultra-stable carbon micro/nano-scale interconnected "carbon cages" has been designed by incorporating polar acid-treated carbon fibers (ACF) into three-dimensional (3D) CNT frameworks during vacuum filtration processes. Results show that the ACF-CNT composite frameworks possess a reinforced-concrete-like structure, in which the ACFs can well work as the main mechanical supporting frames for the composite electrodes, and the oxygen-containing functional groups (OFGs) formed on them as cross linker between ACFs and CNTs. Benefitted from this design, the ACF-CNT/S cathodes deliver an excellent rate capability (retain 72.6% at 4C). More impressively, the ACF-CNT/S cathodes also show an ultrahigh cycling stability (capacity decay rate of 0.001% per cycle over 350 cycles at 2C). And further optimization suggests that the suitable treatment on CFs could balance the chemical adsorption (OFGs) and physical confinement (carbon cages), leading to fast and durable electrochemical reaction dynamics. In addition, the assembled soft-pack LSBs further show a high dynamic bending stability.

10.
J Biomed Nanotechnol ; 15(6): 1345-1353, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31072441

RESUMEN

Gastric cancer is the fourth most common cancer worldwide and the third most common in Asia, with a high mortality. Photodynamic therapy (PDT) is a new treatment for cancer. With advantages of minimum invasiveness, small adverse side effects and high selectivity, PDT can be used as palliative treatment for patients with advanced gastric cancer. YLG I, also known as 2-(1 hexyloxyethyl)-2-devinyl porphin e6 trisodium salt (HCE6), is a recently developed photosensitizer. A previous study showed that HCE6 significantly inhibited the growth of QBC939 human cholangiocarcinoma cells. However, the effects and mechanisms of HCE6 on gastric cancer cell suppression are not known. In this study, we investigated the effects of HCE6 on the human gastric cancer cell line MKN45 and found that at the concentration of 2.0 mg/L, HCE6 almost completely killed MKN45 cells at a light intensity of 3.6 J/cm². RNAseq results confirmed that mitochondria and endoplasmic reticulum (ER)-mediated apoptosis was involved in the effects of HCE6 on cell death, and we also found that HCE6 induced chromosome conformational changes in the early phase of apoptosis. The results of our study help elucidate the molecular mechanisms underlying HCE6-mediated inhibition of gastric cancer cell growth and provide a theoretical basis and molecular targets for the treatment of gastric cancer.


Asunto(s)
Neoplasias Gástricas , Apoptosis , Línea Celular Tumoral , Humanos , Fotoquimioterapia , Fármacos Fotosensibilizantes
11.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(2): 188-192, 2019 Mar.
Artículo en Chino | MEDLINE | ID: mdl-31106537

RESUMEN

OBJECTIVE: To study the relationship between hypoxia and the hypoxia inducible factor-1α (HIF-1α) from lung cancer cells, to reveal the possible mechanism of brain metastases of lung cancer. METHODS: The hypoxia model of A549 lung cancer cells was established. After hypoxia culture of A549 cells for 0.5, 2, 4, 8, 12 and 24 h (normal oxygen culture at the same time point was set as the control group), the mass concentration of HIF-1α in A549 lung cancer cell culture medium were determined by ELISA. Transwell chamber was used to construct an in vitro blood brain barrier model, was treated with A549 lung cancer cell culture medium after different time points of hypoxia, Tran endothelial resistance (TER) change of blood-brain barrier model in instrument, to reflect the changes of blood-brain barrier permeability in vitro; A549 lung cancer cells in the culture medium were counted under Transwell room. A549 lung cancer cells with hypoxia at different time points injected into Wistar rats via tail vein, Western blot method was used to menstruate expression of tight junction associated protein Claudin-5 in the brain tissues, Evans blue to detect the change of blood brain barrier permeability in rats. RESULTS: Compared with the control group, the HIF-1α mass concentration in the cell culture solution of A549 increased, the in vitro blood-brain barrier model TER decreased, and the cell number of A549 that passed through transwell into the lower chamber increased (all P<0.05) after hypoxia 2 h, the above effect was most obvious when hypoxia 8 h (all P<0.01). After hypoxia 24 h, it was restored to the control group level. In the in vivo experiment of rats, compared with the control group, the mass percent of Evans blue in rat brain tissues increased after A549 cell culture solution with hypoxia 2 h was injected via caudal vein, meaning increased the permeability of rat blood brain barrier, while the expression of Claudin-5 protein in rat brain tissues decreased (all P<0.05). The effect was most obvious when A549 cell culture solution with hypoxia 8 h was injected into rat tail vein (P<0.01 ). Ejectionof hypoxia 24 h A549 cell culture solution yielded the same effects as those in the control group. CONCLUSION: Hypoxia can induce the increase of HIF-1α in lung cancer cells. The increase of HIF-1α results in the decrease of Claudin-5 expression and increase of blood-brain barrier permeability, leading to lung cancer cells metastasis into the brain.


Asunto(s)
Neoplasias Encefálicas/secundario , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Neoplasias Pulmonares/patología , Células A549 , Animales , Hipoxia de la Célula , Humanos , Trasplante de Neoplasias , Ratas , Ratas Wistar
12.
Orthopedics ; 35(8): 702-8, 2012 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-22868596

RESUMEN

The optimal treatment approach for the initial management of radial nerve palsy associated with humeral shaft fractures has yet to be conclusively determined. The authors performed a systematic review of the literature to identify studies that compared the outcomes after initial nonoperative and operative management for radial nerve palsy associated with acute humeral shaft fractures. A meta-analysis of the data from these studies was also performed to determine whether recovery from radial nerve palsy was more favorable in one approach compared with the other. The primary outcome was recovery from radial nerve palsy and the secondary outcome was complaints after treatment. Nine articles (1 prospective observational and 8 retrospective) were included in the meta-analyses. Operative management showed no improved recovery from radial nerve palsy compared with nonoperative management. Nonoperative management was associated with a decreased risk of complaints relative to operative management. Recovery from radial nerve palsy associated with acute humeral shaft fractures is not influenced by the initial management approach.


Asunto(s)
Fracturas del Húmero/terapia , Neuropatía Radial/terapia , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Fracturas del Húmero/complicaciones , Fracturas del Húmero/cirugía , Masculino , Persona de Mediana Edad , Neuropatía Radial/etiología , Neuropatía Radial/cirugía , Adulto Joven
13.
Zhongguo Gu Shang ; 25(10): 817-20, 2012 Oct.
Artículo en Chino | MEDLINE | ID: mdl-23342795

RESUMEN

OBJECTIVE: To explore clinical presentations and the operational opportunity of traumatic cervical disc herniation. METHODS: From June 2002 to June 2009,40 patients with traumatic cervical disc herniation were treated. There were 24 males and 16 females, with an average age of 43.2 years old ranging from 30 to 56 years. There were 36 patients with single intervertebral disc herniation and 4 patients with double. The injury level of those patients were at C3,4 in 16 cases, C4,5 in 10 cases, C5,6 in 12 cases and C6,7 in 6 cases. Among them, 18 patients showed spinal cord signal changes by MRI, 5 patients suffered from nothing but neck and shoulder pain, 8 patients with nerve root stimulation; 10 patients with spinal cord compression, and 17 patients had both nerve root stimulation and spinal cord compression symptoms. Conservative treatment were applied to 13 patients with neck and shoulder pain and nerve root stimulation, 5 cases of which were transferred to operation in case of poor effects, and Odom criteria were used to assess operational effects. Twenty-seven patients with spinal cord compression accepted operation from 1 to 27days after their trauma, 16 of which were operated in 5 days (early operational group with an JOA score of 11.3 +/- 2.8), other 11 cases were operated from 5 to 27 days (delayed operational group with an JOA score of 11.4 +/- 2.9 ), then functional assessment of spinal cord were assessed according to JOA criteria. RESULTS: Three patients who were transferred from conservative treatment recovered excellently according to Odom criteria and the other 2 were good at final followed-up. JOA score of early operational group increased from (11.3 +/- 2.8) to (15.3 +/- 1.8) one week after operation (P < 0.01), and (15.9 +/- 1.4) at final followed-up (P < 0.01). JOA score of delayed operational group increased from (11.4 +/- 2.9) to (14.0 +/- 2.6) one week after operation (P < 0.01), and (15.3 +/- 1.5) at final followed-up (P < 0.01). The recovery ratio of JOA score of early operational group were (74.6 +/- 16.8)% 1 week after operation,and increased to (85.6 +/- 13.6)% at final followed-up; while that of delayed operational group were (50.9 +/- 17.5)% and (68.2 +/- 21.5)%, and there were significant difference between early operational group and delayed operational group both at 1 week postoperation and final followup (P < 0.05). CONCLUSION: There are some difference in pathological segment and imaging manifestation between traumatic cervical disc herniation and cervical spondylosis. Early operation is favorable to the recovery of neurological function in patients with spinal cord compression.


Asunto(s)
Vértebras Cervicales/lesiones , Desplazamiento del Disco Intervertebral/cirugía , Adulto , Vértebras Cervicales/cirugía , Femenino , Humanos , Desplazamiento del Disco Intervertebral/fisiopatología , Masculino , Persona de Mediana Edad
14.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 33(12): 1148-53, 2008 Dec.
Artículo en Chino | MEDLINE | ID: mdl-19141984

RESUMEN

OBJECTIVE: To evaluate the feasibility of endoscopic paravertebral approach surgery in the far lateral lumbar disc herniation. METHODS: Fifty sets of integral lumbar vertebral specimens were selected, and the anatomical data of lumbar intervertebral foramina and its adjacent structures were measured. Twenty specimens are randomly divided into a traditional group and an endoscopic group, then the traditional and endoscopic operations by paravertebral approach were used to dissect every strata of soft tissues in order to expose the intervertebral foramen. At last,the relationship between the intervertebral foramen and its adjacent structures was observed, and the 2 procedures were compared. RESULTS: The sagittal diameter of lumbar intervertebral foramina became shorter from the top to bottom,while the diameter of cross section of relative nerve roots became longer. The depth of the line which connected the middle point of the 2 adjacent transverse process roots and the anterior branch of lumber nerve root in L1,L3 and L5 was (1.03+/-0.30), (1.71+/-0.29), and (1.99+/-0.34) mm respectively, with the increasing tendency; the depth of L3 to L5 was mostly less than 2 cm. The distance of the middle points of the 2 adjacent transverse process roots from L1 to L5 was long enough, but the distance between L5 and S1 was only (10.14+/-1.71) mm. The surgery by paravertebral approach had a relative safe operation area,which was similar to a triangle. CONCLUSION: The technique of endoscopic surgery by paravertebral approach is feasible in the treatment of far lateral lumbar disc herniation. However, it is difficult to perform this surgery in the treatment of L5/S1 far lateral lumbar disc herniation, which is often conducted with endoscopy, after 18 to approximately 20 mm of the partial sacrum is eliminated by conventional method.


Asunto(s)
Discectomía/métodos , Endoscopía/métodos , Desplazamiento del Disco Intervertebral/cirugía , Vértebras Lumbares/cirugía , Adulto , Cadáver , Estudios de Factibilidad , Femenino , Humanos , Desplazamiento del Disco Intervertebral/clasificación , Masculino
15.
Hunan Yi Ke Da Xue Xue Bao ; 27(1): 55-7, 2002 Feb 28.
Artículo en Chino | MEDLINE | ID: mdl-12575237

RESUMEN

OBJECTIVE: To explore the application of three dimensional(3D) CT reconstruction(3D-CT-R) in spinal stenosis and injury of the bone and joint. METHODS: Forty cases were examined with the X-ray film, CT scan and 3D-CT-R. To evaluate their diagnostic value, the images of the three methods were compared. RESULTS: X-ray films could show a visible shift of fracture pieces, but we were sometimes incapable of diagnosing fractures accurately from X-ray and, therefore, we couldn't diagnose fractures located at a special position; the CT scan could show the fractured place with a better result, but it required that doctors should have enough clinic experience, and should be familiar with local anatomy to avoid possible misdiagnosis. CONCLUSION: 3D-CT-R could be used in formulating a particular treatment scheme, and is an ideal examination method.


Asunto(s)
Fracturas de Cadera/diagnóstico por imagen , Luxaciones Articulares/diagnóstico por imagen , Estenosis Espinal/diagnóstico por imagen , Adulto , Femenino , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Fracturas de la Tibia/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos
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