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1.
Food Chem ; 366: 130576, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34348222

RESUMO

Cinnamon oil is obtained by steam distillation from cinnamon leaves and is usually considered highly cost-effective compared to bark oil, however, which results in tons of waste cinnamon leaves (WCL) discarded annually. By using MS/MS molecular networking (MN) assisted profiling, six main chemical diversities including flavonols and flavones, phenolic acids, lactones, terpenoids, phenylpropanoids and flavanols were rapid revealed from WCL aqueous extract. 101 compounds were tentatively identified by assigning their MS/MS fragments within typical pathways under ESI-MS/MS dissociation. The featured phenolic acids, terpenoids and their glycosides in cinnamon species were recognized as the main constituents of WCL. The hydrophilic lactones, lignans and flavanols were reported for the first time in cinnamon leaves. Furthermore, ABTS and FRAP assays integrated with MN analysis were conducted to uncover an antioxidant fraction, from which 40 potential antioxidant compounds were rapidly annotated. This fundamental information will help expand the utilization of WCL from cinnamon oil industry.


Assuntos
Antioxidantes , Cinnamomum zeylanicum , Cromatografia Líquida , Extratos Vegetais , Espectrometria de Massas em Tandem
2.
Nanoscale ; 13(45): 19210-19217, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34787151

RESUMO

Lithium-ion capacitors (LICs) have attracted much attention considering their efficient combination of high energy density and high-power density. However, to meet the increasing requirements of energy storage devices and the flexible portable electronic equipment, it is still challenging to develop flexible LIC anodes with high specific capacity and excellent rate capability. Herein, we propose a delicate bottom-up strategy to integrate unique Schiff-base-type polymers into desirable one-dimensional (1D) polymeric structures. A secondary-polymerization-induced template-oriented synthesis approach realizes the 1D integration of Schiff-base porous organic polymers with appealing characteristics of a high nitrogen-doping level and developed pore channels, and a further thermalization yields flexible nitrogen-enriched carbon nanofibers with high specific capacity and fast ion transport. Remarkably, when used as the flexible anode in LICs, the NPCNF//AC LIC demonstrates a high energy density of 154 W h kg-1 at 500 W kg-1 and a high power density of 12.5 kW kg-1 at 104 W h kg-1. This work may provide a new scenario for synthesizing 1D Schiff-base-type polymer derived nitrogen-enriched carbonaceous materials towards promising free-standing anodes in LICs.

3.
DNA Cell Biol ; 40(11): 1381-1395, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34735293

RESUMO

Gliomas are common intracranial tumors with high morbidity and mortality in adults. Transmembrane protein 2 (TMEM2) is involved in the malignant behavior of solid tumors. TMEM2 regulates cell adhesion and metastasis as well as intercellular communication by degrading nonprotein components of the extracellular matrix. This study aimed to evaluate the relationship between TMEM2 expression levels and glioma subtypes or patient prognosis. Our findings revealed that TMEM2 expression was abnormally upregulated in high-grade glioma. Moreover, combining TMEM2, the status of isocitrate dehydrogenase (IDH) and 1p19q, we subdivided molecular subtypes with significant differences in survival. Patients in the MT-codel-low subgroup had better prognosis than those in the WT-no-codel-high subgroup, who fared the worst. Additionally, correlation analysis of TMEM2 and immune cell infiltration indicated an altered tumor microenvironment (TME) and cell redistribution in the TMEM2 high-expression subtype. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that focal adhesion and PI3K-Akt signaling pathways were enriched in the TMEM2-expressing group. In conclusion, aberrant TMEM2 expression can be used as an independent prognostic marker for refining glioma molecular subtyping and accurate prognosis. These findings will improve rational decision making to provide individualized therapy for patients with glioma.


Assuntos
Glioma/genética , Proteínas de Membrana/genética , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/patologia , China , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 19/genética , Biologia Computacional/métodos , Bases de Dados Genéticas , Glioma/classificação , Glioma/metabolismo , Humanos , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Proteínas de Membrana/metabolismo , Mutação , Prognóstico , Microambiente Tumoral
4.
PLoS Negl Trop Dis ; 15(11): e0009943, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34788282

RESUMO

B cells played an important role in Schistosoma infection-induced diseases. TLR7 is an intracellular member of the innate immune receptor. The role of TLR7 on B cells mediated immune response is still unclear. Here, C57BL/6 mice were percutaneously infected by S. japonicum for 5-6 weeks. The percentages and numbers of B cells increased in the infected mice (p < 0.05), and many activation and function associated molecules were also changed on B cells. More splenic cells of the infected mice expressed TLR7, and B cells were served as the main cell population. Moreover, a lower level of soluble egg antigen (SEA) specific antibody and less activation associated molecules were found on the surface of splenic B cells from S. japonicum infected TLR7 gene knockout (TLR7 KO) mice compared to infected wild type (WT) mice (p < 0.05). Additionally, SEA showed a little higher ability in inducing the activation of B cells from naive WT mice than TLR7 KO mice (p < 0.05). Finally, the effects of TLR7 on B cells are dependent on the activation of NF-κB p65. Altogether, TLR7 was found modulating the splenic B cell responses in S. japonicum infected C57BL/6 mice.

5.
Zhongguo Zhong Yao Za Zhi ; 46(20): 5247-5252, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34738426

RESUMO

In this study, the rhizobacteria and actinomycetes of Polygonum multiflorum were screened for the strains with indole acetic acid(IAA)-producing capacity by Salkowski method, the siderophore-producing strains by Chrome Azurol S(CAS) assay, and the strains with inorganic phosphorus-solubilizing capacity by PKO inorganic phosphorus medium. The strains were identified by morphological identification, physiological and biochemical characteristics, and 16 S rDNA sequences. Furthermore, the effect of growth-promoting strains on the seed germination and development of P. multiflorum was tested. The results showed that among 196 strains, two strains F17 and F42 were found to be capable of producing IAA and siderophore and solubilizing inorganic phosphorus simulta-neously. For F17 and F42, the results are listed below: 38.65 and 33.64 mg·L~(-1) for IAA production, 0.85 and 0.49 for siderophore-producing capacities(A_s/A_r), and 1.35 and 1.70 for inorganic phosphorus-solubilizing capacities(D/d), respectively. Comprehensive analysis revealed that strains F17 and F42 were identified as Pseudochrobactrum asacharolyticum and Bacillus aryabhattai, respectively, and both could significantly promote the seed germination of P. multiflorum.


Assuntos
Fallopia multiflora , Germinação , Bacillus , Sementes , Microbiologia do Solo
6.
Pathol Oncol Res ; 27: 1609825, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34629960

RESUMO

Background: Glioma is the primary malignant tumor of the central nervous system and presents high mortality and disability rates under existing treatment measures. Thioredoxin domain-containing 12 (TXNDC12) has been shown to play an important role in various malignant tumors. Therefore, we explored the clinicopathological characteristics of TXNDC12 in glioma to bring to light new ideas in its treatment. Methods: We obtained data packages related to TXNDC12 expression status in gliomas from public databases. We analyzed glioma TXNDC12 expression and patient survival status and validated the above results using glioma specimens from our institution. Next, we analyzed the value of TXNDC12 in combination with 1p19q and isocitrate dehydrogenase (IDH) on the prognosis of glioma by regression model and receiver operating characteristic curve (ROC). Finally, we explored the function of related genes by GO analysis and KEGG analysis. Results: Compared with normal brain tissue, the expression of TXNDC12 in glioma cells, regarding both mRNA and protein levels, was significantly upregulated. The survival time of patients with high-expression of TXNDC12 in glioma cells was shortened. In the World Health Organization pathological classification, IDH status, 1p19q status, and IDH combined with 1p19q subgroups, the expression of TXNDC12 increased with the deterioration of the above indicators. Tumor local immune analysis showed that the immune cell infiltration in TXNDC12 high-expressing glioma tissue increased, the tumor purity was reduced. GO and KEGG analyses indicated that TXNDC12 may be involved in the malignant prognosis of glioma through glycosylation and antigen processing and presentation. Conclusion: We showed that TXNDC12 is significantly highly expressed in gliomas. This high expression predicts the poor prognosis of glioma patients and is related to the gliomas' local immune microenvironment. As a tumor-related gene, TXNDC12 may be used as a new prognostic judgment molecule.

7.
Mucosal Immunol ; 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34686839

RESUMO

Group 2 innate lymphoid cells (ILC2s) play an important role in allergic airway inflammation. Despite recent advances in defining molecular mechanisms that control ILC2 development and function, the role of endogenous metabolites in the regulation of ILC2s remains poorly understood. Herein, we demonstrated that bilirubin, an end product of heme catabolism, was a potent negative regulator of ILC2s. Bilirubin metabolism was found to be significantly induced during airway inflammation in mouse models. The administration of unconjugated bilirubin (UCB) dramatically suppressed ILC2 responses to interleukin (IL)-33 in mice, including cell proliferation and the production of effector cytokines. Furthermore, UCB significantly alleviated ILC2-driven airway inflammation, which was aggravated upon clearance of endogenous UCB. Mechanistic studies showed that the effects of bilirubin on ILC2s were associated with downregulation of ERK phosphorylation and GATA3 expression. Clinically, newborns with hyperbilirubinemia displayed significantly lower levels of ILC2 with impaired function and suppressed ERK signaling. Together, these findings indicate that bilirubin serves as an endogenous suppressor of ILC2s and might have potential therapeutic value in the treatment of allergic airway inflammation.

8.
Natl Sci Rev ; 8(9): nwab012, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34691733

RESUMO

Microparticulate silicon (Si), normally shelled with carbons, features higher tap density and less interfacial side reactions compared to its nanosized counterpart, showing great potential to be applied as high-energy lithium-ion battery anodes. However, localized high stress generated during fabrication and particularly, under operating, could induce cracking of carbon shells and release pulverized nanoparticles, significantly deteriorating its electrochemical performance. Here we design a strong yet ductile carbon cage from an easily processing capillary shrinkage of graphene hydrogel followed by precise tailoring of inner voids. Such a structure, analog to the stable structure of plant cells, presents 'imperfection-tolerance' to volume variation of irregular Si microparticles, maintaining the electrode integrity over 1000 cycles with Coulombic efficiency over 99.5%. This design enables the use of a dense and thick (3 mAh cm-2) microparticulate Si anode with an ultra-high volumetric energy density of 1048 Wh L-1 achieved at pouch full-cell level coupled with a LiNi0.8Co0.1Mn0.1O2 cathode.

9.
Phys Chem Chem Phys ; 23(38): 21385-21398, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34549210

RESUMO

Lithium-sulfur batteries (LSBs) have received intensive attention in recent years due to their high theoretical energy density derived from the lithiation of sulfur. In the discharge process, sulfur transforms into lithium polysulfides (LiPSs) that dissolve in liquid electrolytes and then into insoluble Li2S precipitated on the electrode surface. The electronically and ionically insulating Li2S leads to two critical issues, including the sluggish reaction kinetics from LiPSs to Li2S and the passivation of the electrode. In this regard, controlling the Li2S deposition is significant for improving the performance of LSBs. In this perspective, we have summarized the recent achievements in regulating the Li2S deposition to enhance the performance of LSBs, including the solution-mediated growth of Li2S, sulfur host enhanced nucleation and catalysis induced kinetic improvement. Moreover, the challenges and possibilities for future research studies are discussed, highlighting the significance of regulating the Li2S deposition to realize the high electrochemical performance and promote the practical uses of LSBs.

10.
Nat Commun ; 12(1): 5714, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34588446

RESUMO

Sulfur is an important electrode material in metal-sulfur batteries. It is usually coupled with metal anodes and undergoes electrochemical reduction to form metal sulfides. Herein, we demonstrate, for the first time, the reversible sulfur oxidation process in AlCl3/carbamide ionic liquid, where sulfur is electrochemically oxidized by AlCl4- to form AlSCl7. The sulfur oxidation is: 1) highly reversible with an efficiency of ~94%; and 2) workable within a wide range of high potentials. As a result, the Al-S battery based on sulfur oxidation can be cycled steadily around ~1.8 V, which is the highest operation voltage in Al-S batteries. The study of sulfur oxidation process benefits the understanding of sulfur chemistry and provides a valuable inspiration for the design of other high-voltage metal-sulfur batteries, not limited to Al-S configurations.

11.
Front Immunol ; 12: 687919, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34475870

RESUMO

Background: Th cells (helper T cells) have multiple functions in Schistosoma japonicum (S. japonicum) infection. Inducible co-stimulator (ICOS) is induced and expressed in activated T lymphocytes, which enhances the development of B cells and antibody production through the ICOS/ICOSL pathway. It remains unclear about the role and possible regulating mechanism of ICOS+ Th cells in the spleen of S. japonicum-infected C57BL/6 mice. Methods: C57BL/6 mice were infected with cercariae of S. japonicum through the abdomen. The expression of ICOS, activation markers, and the cytokine production on CD4+ ICOS+ Th cells were detected by flow cytometry (FCM) and quantitative real-time PCR (qRT-PCR). Moreover, the differentially expressed gene data of ICOS+ and ICOS- Th cells from the spleen of infected mice were obtained by mRNA sequencing. Besides, Western blot and chromatin immunoprecipitation (ChIP) were used to explore the role of Ikzf2 on ICOS expression. Results: After S. japonicum infection, the expression of ICOS molecules gradually increased in splenic lymphocytes, especially in Th cells (P < 0.01). Compared with ICOS- Th cells, more ICOS+ Th cells expressed CD69, CD25, CXCR5, and CD40L (P < 0.05), while less of them expressed CD62L (P < 0.05). Also, ICOS+ Th cells expressed more cytokines, such as IFN-γ, IL-4, IL-10, IL-2, and IL-21 (P < 0.05). RNA sequencing results showed that many transcription factors were increased significantly in ICOS+ Th cells, especially Ikzf2 (P < 0.05). And then, the expression of Ikzf2 was verified to be significantly increased and mainly located in the nuclear of ICOS+ Th cells. Finally, ChIP experiments and dual-luciferase reporter assay confirmed that Ikzf2 could directly bind to the ICOS promoter in Th cells. Conclusion: In this study, ICOS+ Th cells were found to play an important role in S. japonicum infection to induce immune response in the spleen of C57BL/6 mice. Additionally, Ikzf2 was found to be one important transcription factor that could regulate the expression of ICOS in the spleen of S. japonicum-infected C57BL/6 mice.


Assuntos
Fator de Transcrição Ikaros/metabolismo , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Ativação Linfocitária , Schistosoma japonicum/patogenicidade , Esquistossomose Japônica/parasitologia , Baço/parasitologia , Linfócitos T Auxiliares-Indutores/parasitologia , Animais , Sítios de Ligação , Proliferação de Células , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Interações Hospedeiro-Parasita , Fator de Transcrição Ikaros/genética , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas , Schistosoma japonicum/imunologia , Esquistossomose Japônica/genética , Esquistossomose Japônica/imunologia , Esquistossomose Japônica/metabolismo , Transdução de Sinais , Baço/imunologia , Baço/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo
12.
Chin Neurosurg J ; 7(1): 37, 2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34372942

RESUMO

BACKGROUND: Tumors are the second most common cause of death in humans worldwide, second only to cardiovascular and cerebrovascular diseases. Although methods and techniques for the treatment of tumors continue to improve, the effect is not satisfactory. These may lack effective therapeutic targets. This study aimed to evaluate the value of SNHG12 as a biomarker in the prognosis and clinical characteristics of various cancer patients. METHODS: We analyzed SNHG12 expression and plotted the survival curves of all cancer samples in the TCGA database using the GEPIA tool. Then, we searched for eligible papers up to April 1, 2019, in databases. Next, the data were extracted from studies examining SNHG12 expression, overall survival and clinicopathological features in patients with malignant tumors. We used Review Manager 5.3 and Stata 15 software to analyze the statistical data. RESULTS: In the TCGA database, abnormally high expression of SNHG12 in tumor samples indicates that the patient has a poor prognosis. Results of meta-analysis is that SNHG12 high expression is related to low overall survival (HR = 2.72, 95% CI = 1.95-3.8, P < 0.00001), high tumor stage (OR = 3.94, 95% CI = 2.80-5.53, P < 0.00001), high grade (OR = 2.04, 95% CI = 1.18-3.51, P = 0.01), distant metastasis (OR = 2.20, 95% CI = 1.40-3.46, P = 0.0006), tumor size (OR = 2.79, 95% CI = 1.89-4.14, P < 0.00001), and lymph node metastasis (OR = 2.66, 95% CI = 1.65-4.29, P < 0.0001). CONCLUSIONS: Our study confirmed that the high expression level of SNHG12 is closely related to the clinicopathological characteristics and prognosis of patients and is a new predictive biomarker for various cancer patients.

13.
Adv Mater ; 33(38): e2101006, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34338356

RESUMO

The shuttling of soluble lithium polysulfides between the electrodes leads to serious capacity fading and excess use of electrolyte, which severely bottlenecks practical use of Li-S batteries. Here, selective catalysis is proposed as a fundamental remedy for the consecutive solid-liquid-solid sulfur redox reactions. The proof-of-concept Indium (In)-based catalyst targetedly decelerates the solid-liquid conversion, dissolution of elemental sulfur to polysulfides, while accelerates the liquid-solid conversion, deposition of polysulfides into insoluble Li2 S, which basically reduces accumulation of polysulfides in electrolyte, finally inhibiting the shuttle effect. The selective catalysis is revealed, experimentally and theoretically, by changes of activation energies and kinetic currents, modified reaction pathway together with the probed dynamically changing catalyst (LiInS2 catalyst), and gradual deactivation of the In-based catalyst. The In-based battery works steadily over 1000 cycles at 4.0 C and yields an initial areal capacity up to 9.4 mAh cm-2 with a sulfur loading of ≈9.0 mg cm-2 .

14.
J Ethnopharmacol ; 281: 114534, 2021 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-34419609

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Hanchuan Zupa Granule (HCZP) is a classic prescription of Uyghur medicine, that is used for cough and abnormal mucinous asthma caused by a cold and "Nai-Zi-Lai". AIM OF THE STUDY: This study aimed to explore the possible molecular mechanism of HCZP in the treatment of asthma, using a network pharmacology method and in vivo experiments. MATERIALS AND METHODS: First, we conducted qualitative analysis of the chemical composition of HCZP as a basis for network pharmacology analysis. Using network pharmacology tools, the possible signaling pathways of HCZP in the treatment of asthma were obtained. An OVA-sensitized asthma model was established, and HCZP was continuously administered for one week. BALF was collected for cell counting, and serum and lung tissues were collected to analyze the expression of IgE, IL-4, IL-5, IL-13 and IFN-γ. Hematoxylin & eosin (H&E) staining was performed to assess the pathological changes in the lung tissues. Related protein expression in the lung tissues was analyzed by Western blotting for molecular mechanism exploration. RESULTS: Fifty-six chemical compounds were identified by UPLC Q-TOF MS. According to the network pharmacology results, 18 active compounds were identified among the 56 compounds, and 68 target genes of HCZP in the treatment of asthma were obtained. A total of 19 pathways were responsible for asthma (P < 0.05) according to KEGG pathway analysis. In vivo results showed that OVA sensitivity induced increased respiratory system resistance and inflammatory responses, which included inflammatory cell infiltration and high levels of IgE, IL-4, IL-5 and IL-13 in serum and lung tissues. Furthermore, OVA upregulated p-PI3K, p-JNK and p-p38 expression in lung tissues. Moreover, HCZP treatment significantly downregulated respiratory system resistance, and the expression of IL-4, IL-5, IL-13 and IgE, as well as significantly improved inflammatory cell infiltration in lung tissues. Moreover, the protein expression of p-PI3K, p-JNK and p-p38 in lung tissues decreased after HCZP treatment. CONCLUSION: HCZP significantly inhibited the OVA-induced inflammatory response via the PI3K-Akt and Fc epsilon RI signaling pathways.

15.
Anat Rec (Hoboken) ; 304(11): 2552-2558, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34324795

RESUMO

Fu's subcutaneous needling (FSN) is a new acupuncture therapy developed from acupuncture and Traditional Chinese Medicine models. The aim of this study was to investigate the effect of FSN on shoulder pain. In this retrospective comparative study, patient case files with shoulder pain (Group A) treated with FSN were analyzed and compared with the same number of patients with shoulder pain (Group B) treated with conventional acupuncture and physical therapy. Motion-related pain (MRP), pain under pressure (PUP), and Range of motion (ROM) were collected before and after intervention. In the 68 patients, there were 39 males and 29 females, aged 21-53 years old (mean ± SD = 36.4 ± 8.15) with onset time ranging from 1 day to 7 days (mean ± SD = 3.15 ± 1.73). MRP, PUP, and ROM scores were improved after FSN intervention (p < .05). There were significant differences between group A and group B in MRP, PUP, and ROM scores after FSN intervention and 1 week follow-up (p < .05). No adverse events, such as fainting and sharp pain, occurred during the treatment process. FSN can be an effective rehabilitation intervention for improving shoulder pain and shoulder range of motion.

16.
J Coll Physicians Surg Pak ; 30(6): 699-702, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34102783

RESUMO

OBJECTIVE: To compare the therapeutic effects and olfactory function of oral glucocorticoid and intranasal glucocorticoid in patients with chronic rhinosinusitis (CRS) with nasal polyps. STUDY DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Suzhou Hospital of Integrated Traditional Chinese and Western Medicine, from January 2018 to November 2019. METHODOLOGY: One hundred and twenty-two CRS patients with nasal polyps were randomly divided into Group A and Group B with 61 cases in each group. Group A received local application of glucocorticoid (dexamethasone) after nasal endoscopic surgery. Group B received oral glucocorticoid (prednisone) one week before operation and three weeks after operation. Clinical effects of the two groups were compared. RESULTS: Total effective rate of Group B was higher than that of Group A (p=0. 023), recurrence rate in Group B was lower than that in Group A (p=0.015). Nasal airway resistance and olfactory function scores of Group B were lower than those of Group A at one month, three months and six months after operation (all p <0.001). There was no difference in the incidence of adverse reactions between the two groups (p=0. 649). CONCLUSION: Compared with intranasal glucocorticoid, oral glucocorticoid can obviously improve the therapeutic effect and olfactory function of patients, and the postoperative recurrence rate is lower. Key Words: Sinusitis, Nasal polyps, Endoscopic sinus surgery, Glucocorticoid.


Assuntos
Pólipos Nasais , Rinite , Sinusite , Administração Intranasal , Doença Crônica , Endoscopia , Glucocorticoides/uso terapêutico , Humanos , Pólipos Nasais/tratamento farmacológico , Rinite/tratamento farmacológico , Sinusite/tratamento farmacológico
17.
Adv Mater ; 33(31): e2101745, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34146362

RESUMO

Alkali metals have low potentials and high capacities, making them ideal anodes for next-generation batteries, but they suffer major problems, including dendrite growth and low Coulombic efficiency (CE). Achieving uniform metal deposition and having a reliable solid electrolyte interphase (SEI) are the basic requirements for overcoming these problems. Here, a general remedy is reported for various alkali-metal anodes by the supramolecularization of alkali-metal cations with crown ethers that follows a size-matching rule. The positively charged supramolecular complex provides electrostatic shielding layers to regulate metal deposition and suppress dendrite formation. More promisingly, it reforms electric double layers and drives the production of organic-dominated SEIs with improved flexibility that can accommodate large volume changes. The high flexibility of SEIs during metal deposition and dissolution reduces the amount of dead metal and improves CE and cycling stability. Specifically, a 200% excess Li-based full cell has a capacity retention of ≈100% after 100 cycles. This crown-like supramolecularization strategy is a new chemistry that may be used for the production of dendrite-free metal-anode-based batteries not limited to the cases with alkali metal. It is also expected as a practical technology to improve the uniformity of coatings produced in the electrodeposition industry.

18.
Small ; 17(31): e2101538, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34160905

RESUMO

Catalysis is an effective remedy for the fast capacity decay of lithium-sulfur batteries induced by the shuttling of lithium polysulfides (LiPSs), but too strong adsorption ability of many catalysts toward LiPSs increases the risk of catalyst passivation and restricts the diffusion of LiPSs for conversion. Herein, perovskite bimetallic hydroxide (CoSn(OH)6 ) nanocages are prepared, which are further wrapped by reduced graphene oxide (rGO) as the catalytic host for sulfur. Because of the coordinated valence state of Co and Sn and the intrinsic defect of the perovskite structure, such bimetallic hydroxide delivers moderate adsorption ability and enhanced catalytic activity toward LiPS conversion. Coupled with the hollow structure and the wrapped rGO as double physical barriers, the redox reaction kinetics, and sulfur utilization are effectively improved with such a host. The assembled battery delivers a good rate performance with a high capacity of 644 mAh g-1 at 2 C and long stability with a capacity decay of 0.068% per cycle over 600 cycles at 1 C. Even with a higher sulfur loading of 3.2 mg cm-2 and a low electrolyte/sulfur ratio of 5 µL mg-1 , the battery still shows high sulfur utilization and good cycling stability.

19.
Nanomaterials (Basel) ; 11(5)2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34068361

RESUMO

Determining the metallicity and semiconductivity of a multi-walled carbon nanotube (MWCNT) bundle plays a particularly vital role in its interconnection with the metal electrode of an integrated circuit. In this paper, an effective method is proposed to determine the electrical transport properties of an MWCNT bundle using a current-voltage characteristic curve during its electrical breakdown. We established the reliable electrical nanoscale contact between the MWCNT bundle and metal electrode using a robotic manipulation system under scanning electron microscope (SEM) vacuum conditions. The experimental results show that the current-voltage curve appears as saw-tooth-like current changes including up and down steps, which signify the conductance and breakdown of carbon shells in the MWCNT bundle, respectively. Additionally, the power law nonlinear behavior of the current-voltage curve indicates that the MWCNT bundle is semiconducting. The molecular dynamics simulation explains that the electron transport between the inner carbon shells, between the outermost carbon shells and gold metal electrode and between the outermost carbons shells of two adjacent individual three-walled carbon nanotubes (TWCNTs) is through their radial deformation. Density functional theory (DFT) calculations elucidate the electron transport mechanism between the gold surface and double-wall carbon nanotube (DWCNT) and between the inner and outermost carbon shells of DWCNT using the charge density difference, electrostatic potential and partial density of states.

20.
Front Psychol ; 12: 666329, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34122258

RESUMO

People often feel that a period of time becomes longer when it is described in more detail or cut into more segments, which is known as the time unpacking effect. The current study aims to unveil how time unpacking manipulation impacts intertemporal decision making and whether the gain-loss valence of choices moderates such impacts. We recruited 87 college students (54 female) and randomly assigned them to the experimental conditions to complete a series of intertemporal choice tasks. The subjective values of the delayed choices were calculated for each participant and then analyzed. The results showed that participants perceived longer time delays and higher subjective values on the delayed gains (but not losses) in the time unpacking conditions than in the time packing conditions. These results suggest that time unpacking manipulation not only impacts time perception but also other factors, which in turn, influence the valuation of delayed outcomes and thereby intertemporal choices. The results are discussed in comparison to previous studies to highlight the complexity of the mechanism underlying the effect of time unpacking on intertemporal decision making.

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