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1.
J Affect Disord ; 347: 469-476, 2024 02 15.
Article in English | MEDLINE | ID: mdl-38065474

ABSTRACT

BACKGROUNDS: Chronic inflammation and oxidative stress play an important role in the pathogenesis of PSD. The main purposes of this study were to examine the dynamic changes of cytokines networks in PSD and the predictive role of early inflammation and oxidative stress for 2-week PSD. METHODS: Patients with ischemic stroke were recruited on day 3, and those with Hamilton Depression Rating Scale 24-Item (HAMD-24) ≥8 were classified as ischemic stroke patients with depressive symptoms and others as ischemic stroke patients without depressive symptoms. Subjects were then followed up at 2 weeks and 3 months, with those meeting diagnostic criteria for depressive symptoms on the HAMD ≥8 and the Statistical Manual of Mental Disorders-V (DSM-V) as the PSD group, and the others as the non-PSD group. RESULTS: At 3 days, IFN-γ, IL-12(p70), IL-12(p40), IL-2, IL-28A/IFNλ2, and IL-19 were elevated in ischemic stroke patients with depressive symptoms. At 2 weeks, IL-12(p40), IL-19, IL-22, IFN-ß and MMP-1 all were increased in PSD patients. At 3 months, IL-2, IFN-ß and sCD163 increased in PSD group. Longitudinally, the inflammatory response decreased significantly in PSD group from 2 weeks to 3 months of follow-up, while it gradually decreased in non-PSD group from 3 days to 3 months of follow-up. SOD was positively related to IL-12(p70), IFN-γ and IL-20. Plasma IFN-γ at 3 days may be a potential predictive biomarker for 2-week PSD. CONCLUSIONS: Peripheral inflammation and oxidative stress are involved in the pathogenesis of PSD, providing new insights for its diagnosis and treatment.


Subject(s)
Ischemic Stroke , Stroke , Humans , Cytokines , Depression/diagnosis , Depression/etiology , Interleukin-2 , Stroke/complications , Inflammation , Interleukin-12 , Oxidative Stress
2.
Brain Pathol ; 34(1): e13202, 2024 01.
Article in English | MEDLINE | ID: mdl-37619589

ABSTRACT

Lipid metabolism and oxidative stress are key mechanisms in Alzheimer's disease (AD). The link between plasma lipid metabolites and oxidative stress in AD patients is poorly understood. This study was to identify markers that distinguish AD and amnestic mild cognitive impairment (aMCI) from NC, and to reveal potential links between lipid metabolites and oxidative stress. We performed non-targeted lipid metabolism analysis of plasma from patients with AD, aMCI, and NC using LC-MS/MS. The plasma malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) levels were assessed. We found significant differences in lipid metabolism between patients with AD and aMCI compared to those in NC. AD severity is associated with lipid metabolites, especially TG (18:0_16:0_18:0) + NH4, TG (18:0_16:0_16:0) + NH4, LPC(16:1e)-CH3, and PE (20:0_20:4)-H. SPH (d16:0) + H, SPH (d18:1) + H, and SPH (d18:0) + H were high-performance markers to distinguish AD and aMCI from NC. The AUC of three SPHs combined to predict AD was 0.990, with specificity and sensitivity as 0.949 and 1, respectively; the AUC of three SPHs combined to predict aMCI was 0.934, with specificity and sensitivity as 0.900, 0.981, respectively. Plasma MDA concentrations were higher in the AD group than in the NC group (p = 0.003), whereas plasma SOD levels were lower in the AD (p < 0.001) and aMCI (p = 0.045) groups than in NC, and GSH-Px activity were higher in the AD group than in the aMCI group (p = 0.007). In addition, lipid metabolites and oxidative stress are widely associated. In conclusion, this study distinguished serum lipid metabolism in AD, aMCI, and NC subjects, highlighting that the three SPHs can distinguish AD and aMCI from NC. Additionally, AD patients showed elevated oxidative stress, and there are complex interactions between lipid metabolites and oxidative stress.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Humans , Alzheimer Disease/psychology , Lipid Metabolism , Chromatography, Liquid , Neuropsychological Tests , Tandem Mass Spectrometry , Oxidative Stress , Lipids , Superoxide Dismutase
3.
Plants (Basel) ; 12(9)2023 May 04.
Article in English | MEDLINE | ID: mdl-37176935

ABSTRACT

Seed vigor is an important aspect of seed quality. High-vigor seeds show rapid and uniform germination and emerge well, especially under adverse environmental conditions. Here, we determined hydrotime model parameters by incubating seeds at different water potentials (0.0, -0.2, -0.4, -0.6, and -0.8 MPa) in the laboratory, for 12 seed lots of Chinese milk vetch (Astragalus sinicus) (CMV), a globally important legume used as forage, green manure, and a rotation crop. Pot experiments were conducted to investigate the seedling emergence performance of 12 CMV seed lots under control, water stress, salinity stress, deep sowing, and cold stress conditions. Meanwhile, the field emergence performance was evaluated on two sowing dates in June and October 2022. Correlation and regression analyses were implemented to explore the relationships between hydrotime model parameters and seedling emergence performance under various environmental conditions. The seed germination percentage did not differ significantly between seed lots when seeds were incubated at 0.0 MPa, whereas it did differ significantly between seed lots at water potentials of -0.2, -0.4, and -0.6 MPa. The emergence percentage, seedling dry weight, and simplified vigor index also differed significantly between the 12 seed lots under various environmental conditions. Ψb(50) showed a significant correlation with germination and emergence performance under various environmental conditions; however, little correlation was observed between θH or σφb and germination and emergence. These results indicate that Ψb(50) can be used to estimate seed vigor and predict seedling emergence performance under diverse environmental conditions for CMV and similar forage legumes. This study will enable seed researchers, plant breeders, and government program directors to target higher seed vigor more effectively for forage legumes.

4.
Front Psychiatry ; 13: 925273, 2022.
Article in English | MEDLINE | ID: mdl-36458128

ABSTRACT

Background: The epigenetic study of childhood trauma has become a valuable field. However, the evolution and emerging trends in epigenetics and childhood trauma have not been studied by bibliometric methods. Objective: This study aims to evaluate status of epigenetic studies in childhood trauma and reveal the research trends based on bibliometrics. Methods: A total of 1,151 publications related to childhood trauma and epigenetics published between 2000 and 2021 were retrieved from the Web of Science Core Collection (WoSCC). CiteSpace (5.8. R 3) was used to implement bibliometric analysis and visualization. Results: Since 2010, the number of related publications has expanded quickly. The United States and McGill University are the most influential countries and research institutes, respectively. Elisabeth Binder is a leading researcher in childhood trauma and epigenetic-related research. Biological Psychiatry is probably the most popular journal. In addition, comprehensive keyword analysis revealed that "glucocorticoid receptor," "brain development," "epigenetic regulation," "depression," "posttraumatic stress disorder," "maternal care," "histone acetylation," "telomere length," "microRNA," and "anxiety" reflect the latest research trends in the field. A comprehensive reference analysis demonstrated NR3C1 gene methylation, FKBP5 DNA methylation, BDNF DNA methylation, and KITLG methylation have been hot spots in epigenetic studies in the field of childhood trauma in recent years. Notably, the relationship between childhood adversity and NR3C1 gene methylation levels remains unresolved and requires well-designed studies with control for more confounding factors. Conclusion: As the best of our knowledge, this is the first bibliometric analysis of the association between childhood trauma and epigenetics. Our analysis of the literature suggests that childhood trauma may induce depression, anxiety, and post-traumatic stress disorder through epigenetic regulation of glucocorticoid receptor expression and brain development. The hypothalamic-pituitary-adrenal axis is the key points of epigenetic research. The current researches focus on NR3C1 gene methylation, FKBP5 DNA methylation, BDNF DNA methylation, and KITLG methylation. These results provide a guiding perspective for the study of epigenetic effects of childhood trauma, and help researchers choose future research directions based on current keywords.

5.
Sci Total Environ ; 836: 155612, 2022 Aug 25.
Article in English | MEDLINE | ID: mdl-35504375

ABSTRACT

Sulfur-based autotrophic denitrification is a cost-effective alternative to heterotrophic denitrification for nitrate removal due to no need of external organic carbon supply. Herein, sulfite-driven autotrophic denitrification (SDAD) was firstly established in a sequencing batch biofilm reactor treating high-strength nitrate-containing wastewater added by the sulfite. The nitrogen removal performance was mainly investigated under a molar ratio of sulfur-to­nitrogen (S/N) ranging from 0.44 to 3.07 in a total of 180-day operation. Long-term experiment showed the optimal of S/N was found to be 2.63, much close to the stoichiometric value, achieving the highest autotrophic denitrification rate and complete total nitrogen removal efficiency (TNRE) with 92.4 ± 0.3%. Cyclical trial confirmed nitrate reduction and sulfite oxidation simultaneously occurred along with sulfate formation. Meanwhile, nitrite accumulation was observed at a very low S/N conditions. Microbial community analysis identified that Sulfurovum, Thiobacillus, and Thermomonas as key denitrifying sulfur-oxidizing bacteria responsible for SDAD. Moreover, the dynamic shift in functional microorganisms affected by influent S/N was also detected. Finally, the metabolic pathway of SDAD process was unraveled via the cooperative encoding of sulfite oxidases (Sor, Apr, Sat) and nitrate-reducing genes. This study sheds light on a new sulfur-cycle autotrophic denitrification process for the bioremediation of nitrate-contaminated wastewater.


Subject(s)
Denitrification , Nitrogen , Bioreactors , Nitrates/metabolism , Sulfites , Sulfur/metabolism , Wastewater/analysis
6.
Front Pharmacol ; 13: 859244, 2022.
Article in English | MEDLINE | ID: mdl-35559267

ABSTRACT

Tanhuo formula (THF), a traditional Chinese medicinal formula, has been demonstrated to be effective in the clinical treatment of acute ischemic stroke (AIS). However, its active ingredients, potential targets, and molecular mechanisms remain unknown. Based on the validation of active ingredient concentrations, our study attempted to elucidate the possible mechanisms of THF based on network pharmacological analysis and experimental validation. Components of THF were screened using network pharmacological analysis, and a compound-target network and protein-protein interaction (PPI) network were constructed. In total, 42 bioactive compounds and 159 THF targets related to AIS were identified. The PPI network identified AKT1, TNF, IL6, IL1B, and CASP3 as key targets. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis demonstrated that the inflammation and apoptotic pathways were enriched by multiple targets. The main components of THF were identified via high-performance liquid chromatography. Subsequently, a validation experiment was conducted, and the expressions of GFAP, C3, TNF-α, and IL-6 were detected via immunofluorescence staining, confirming the inflammatory response at 30 min and 3 days post injury. Immunohistochemical staining for caspase-3 and TUNEL was also performed to assess apoptosis at the same time points. These results indicate that THF can effectively decrease neural cell apoptosis through the caspase-3 pathway and restrain excessive abnormal activation of astrocytes and the release of TNF-α and IL-6, which might be accompanied by the recovery of motor function. Thus, THF may serve as a promising therapeutic strategy for AIS through multiple targets, components, and pathways.

7.
Front Plant Sci ; 13: 853326, 2022.
Article in English | MEDLINE | ID: mdl-35498713

ABSTRACT

Salt stress is a major environmental factor that seriously restricts quinoa seed germination. However, the key regulatory mechanisms underlying the effect of salt stress on the initial imbibition stage of quinoa seeds are unclear. In this study, dry seeds (0 h) and imbibed (8 h) seeds with 450 mM NaCl (artificial salt) and 100% brackish water of Yellow River Estuary (BW, natural salt) were used to assess the key salt responses based on germination, transcriptome, and metabolome analyses. The results indicated that the capacity of germinating seeds to withstand these two salt stresses was similar due to the similarities in the germination percentage, germination index, mean germination time, and germination phenotypes. Combined omics analyses revealed that the common and unique pathways were induced by NaCl and BW. Starch and sucrose metabolism were the only commonly enriched pathways in which the genes were significantly changed. Additionally, amino sugar and nucleotide sugar metabolism, and ascorbate and aldarate metabolism were preferably enriched in the NaCl group. However, glutathione metabolism tended to enrich in the BW group where glutathione peroxidase, peroxiredoxin 6, and glutathione S-transferase were significantly regulated. These findings suggest that the candidates involved in carbohydrate metabolism and antioxidant defense can regulate the salt responses of seed initial imbibition, which provide valuable insights into the molecular mechanisms underlying the effect of artificial and natural salt stresses.

8.
Neurol Sci ; 43(3): 1885-1891, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34532772

ABSTRACT

OBJECTIVE: To evaluate the efficacy and safety outcome and related risk factors of Naoxueshu in the treatment of acute SICH. METHODS: Two hundred twenty patients were enrolled in this study. Diagnosis of SICH was based on neuroimaging. All the patients received regular treatment and Naoxueshu oral liquid 10 ml 3 times a day for 14 consecutive days. Surgical intervention was conducted as needed. Efficacy and safety outcomes were evaluated. RESULTS: Hematoma volume decreased significantly 7 days after Naoxueshu treatment (from 27.3 ± 20.0 to 15.1 ± 15.1 ml, P < 0.0001), and it decreased further in 14-day result (6.9 ± 10.4 ml, P < 0.0001). Patients' neurological function was improved remarkably with NIHSS scores from baseline 13 points to 7-day 7 points (P < 0.0001) and 14-day 4 points (P < 0.0001). Cerebral edema was relieved only 14 days after Naoxueshu treatment (from 3 to 2 points, P < 0.0001). No clinically significant change was found in 7-day and 14-day safety results. Female sex was related independently to large 7-day hematoma volume and worse 7-day NIHSS score while it would not affect patients' 14-day outcomes. Rare cause of SICH (B = 17.4, P = 0.009) alone was related to large 14-day hematoma volume. Worse baseline NIHSS score (B = 0.3, P = 0.003) and early use of Naoxueshu (B = 2.9, P = 0.005) were related to worse 7-day and14-day neurological function. CONCLUSION: Naoxueshu oral liquid could relieve hematoma volume and cerebral edema safely; meanwhile, it could improve patients' neurological function. Sex, cause of SICH, and time from onset to receive Naoxueshu should be taken into consideration in the treatment of SICH.


Subject(s)
Brain Edema , Cerebral Hemorrhage , Brain Edema/diagnostic imaging , Brain Edema/drug therapy , Brain Edema/etiology , Cerebral Hemorrhage/complications , Cerebral Hemorrhage/diagnostic imaging , Cerebral Hemorrhage/drug therapy , Female , Hematoma/complications , Humans , Risk Factors , Treatment Outcome
9.
Brain Behav ; 11(1): e01957, 2021 01.
Article in English | MEDLINE | ID: mdl-33274855

ABSTRACT

OBJECTIVES: Surgical treatment is expected to remove clot immediately in acute spontaneous intracerebral hemorrhage (SICH) patients. The aim of this study was to evaluate whether Naoxueshu could enhance the efficacy of clot removal surgery in acute SICH patients. METHODS: One hundred twenty patients who had been diagnosed as SICH according to neuroimaging were enrolled in this study. They received craniotomy, decompressive craniectomy, or minimally invasive surgical evacuation as appropriate and then were randomized into two groups: the Naoxueshu group (NXS group, n = 60) and the control group (n = 60). All the patients received standard medical management while patients in NXS group also took Naoxueshu oral liquid 10 ml with three times a day for seven consecutive days. The primary outcome was the 7-day hematoma volume and secondary outcomes were 7-day National Institutes of Health Stroke Scale (NIHSS) score and 7-day cerebral edema score. RESULTS: After clot removal surgery, hematoma volume in NXS group (9.5 ± 8.0) was significantly decreased than that in Control group (21.3 ± 22.9, p < .0001) 7 days after surgery. Moreover, cerebral edema was also relieved after 7-day's Naoxueshu treatment (2.5 ± 0.9 vs. 2.9 ± 0.7, p = .043). Since patients in NXS group had worse baseline NIHSS score (17.2 ± 8.1 vs. 13.7 ± 10.1, p = .039), it was reasonable to conclude that Naoxueshu treatment could improve patients' neurological function because 7-day NIHSS score of the two groups was similar. CONCLUSION: Naoxueshu oral liquid could relieve hematoma volume and cerebral edema after clot removal surgery in acute SICH patients. Moreover, it had the potential to improve patients' short-term neurological function.


Subject(s)
Brain Edema , Cerebral Hemorrhage , Brain Edema/diagnostic imaging , Brain Edema/etiology , Cerebral Hemorrhage/diagnostic imaging , Craniotomy , Hematoma/surgery , Humans , Treatment Outcome
10.
ACS Appl Mater Interfaces ; 12(36): 40620-40628, 2020 Sep 09.
Article in English | MEDLINE | ID: mdl-32786246

ABSTRACT

Silicene as a novel and unique two-dimensional nanomaterial attracts considerable research interest; however, obtaining free-standing silicene still poses challenges due to its instability in air. In this work, we report the synthesis of protected silicene through chemical vapor deposition (CVD), in which silicene is sandwiched by graphene (G@S@G) covered on a Cu substrate. Graphene plays the role of both a substrate and protector, which can help silicene stabilize in air. These findings were verified by means of advanced microscopic and spectroscopic investigations accompanied by density functional theory (DFT) simulations. A large area of G@S@G can be obtained and tailored in any type of shape based on the Cu film. G@S@G shows n-type semiconductor character confirmed by a field-effect transistor (FET) device.

11.
Chem Commun (Camb) ; 55(56): 8094-8097, 2019 Jul 09.
Article in English | MEDLINE | ID: mdl-31232422

ABSTRACT

The pressure-induced crystallization of amorphous red phosphorus to black phosphorus was investigated by in situ Raman spectroscopy and high resolution transmission electron microscopy. Raman measurements revealed slow crystallization kinetics. The morphology and crystal structural analysis provided detailed information on nucleation and crystal growth as well as the crystallization mechanism.

12.
Front Physiol ; 9: 933, 2018.
Article in English | MEDLINE | ID: mdl-30079027

ABSTRACT

Aims: To evaluate the clinical efficacy of Naoxueshu oral liquid in the treatment of intracerebral hemorrhage (ICH) patients. Methods: In our study, December 2008 to August 2010, 88 patients with intracerebral hemorrhage were enrolled and 87 patients with complete information of whom 44 patients received Naoxueshu oral liquid plus regular treatment (Naoxueshu group), 43 patients received regular treatment (control group) only. Naoxueshu oral liquid 10 ml was taken in the Naoxueshu group, with 3 times a day for 21 consecutive days. The regular treatment included (1) dehydration treatment by 20% mannitol; (2) therapy to deal with complications including; (3) supportive therapy. The general clinical information, neurological assessment information, laboratory information, and the hematoma volume information were collected and analyzed pre-and post-treatment. Results: We did not find differences in the information between two groups before treatment (p > 0.05). 21-day after treatment, the white blood cell (WBC) count, hematoma volume, the National Institutes of Health Stroke Scale (NIHSS) score, modified Rankin Scale (mRS), Barthel index (BI), and traditional Chinese medicine (TCM) syndrome score in the Naoxueshu group and control group were significantly decreased than before (pnaoxueshu < 0.01, pcontrol < 0.05), and the changes of the WBC count, hematoma volume, NIHSS score, mRS score, and TCM syndrome score in Naoxueshu group were greater than that of control group (P < 0.001). Conclusion: Naoxueshu oral liquid plus regular treatment could decrease the inflammatory response and hematoma, and improve outcomes of ICH patients than regular treatment only. This suggests that Maixueshu oral liquid is a potential treatment for ICH patients.

13.
Talanta ; 144: 275-82, 2015 Nov 01.
Article in English | MEDLINE | ID: mdl-26452822

ABSTRACT

A parallel microscope-based laser-induced fluorescence (LIF), ultraviolet-visible absorbance (UV) and time-of-flight mass spectrometry (TOF-MS) detection for high performance liquid chromatography (HPLC) was achieved and used to determine glucosamine in urines. First, a reliable and convenient LIF detection was developed based on an inverted microscope and corresponding modulations. Parallel HPLC-LIF/UV/TOF-MS detection was developed by the combination of preceding Microscope-based LIF detection and HPLC coupled with UV and TOF-MS. The proposed setup, due to its parallel scheme, was free of the influence from photo bleaching in LIF detection. Rhodamine B, glutamic acid and glucosamine have been determined to evaluate its performance. Moreover, the proposed strategy was used to determine the glucosamine in urines, and subsequent results suggested that glucosamine, which was widely used in the prevention of the bone arthritis, was metabolized to urines within 4h. Furthermore, its concentration in urines decreased to 5.4mM at 12h. Efficient glucosamine detection was achieved based on a sensitive quantification (LIF), a universal detection (UV) and structural characterizations (TOF-MS). This application indicated that the proposed strategy was sensitive, universal and versatile, and it was capable of improved analysis, especially for analytes with low concentrations in complex samples, compared with conventional HPLC-UV/TOF-MS.


Subject(s)
Glucosamine/urine , Chromatography, High Pressure Liquid , Fluorescence , Glucosamine/pharmacokinetics , Humans , Mass Spectrometry/methods
14.
J Biomed Opt ; 20(9): 096007, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26358820

ABSTRACT

Intraductal carcinoma is a precancerous lesion of the breast and the immediate precursor of invasive ductal carcinoma. Multiphoton microscopy (MPM) was used to monitor the progression from intraductal carcinoma to invasive ductal carcinoma, which can improve early detection of precursor lesions and halt progression to invasive neoplastic disease. It was found that MPM has the capability to reveal the qualitative changes in features of cells, structure of basement membranes, and architecture of collagens during the development from intraductal carcinoma to invasive ductal carcinoma, as well as the quantitative alterations in nuclear area, circle length of basement membrane, and collagen density. Combined with intra-fiberoptic ductoscopy or transdermal biopsy needle, MPM has the potential to provide immediate histological diagnosis of tumor progression in the field of breast carcinoma.


Subject(s)
Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Image Interpretation, Computer-Assisted/methods , Microscopy, Fluorescence, Multiphoton/methods , Adult , Aged , Breast Neoplasms/diagnosis , Carcinoma, Ductal, Breast/diagnosis , Disease Progression , Female , Humans , Middle Aged
15.
Dalton Trans ; 44(40): 17473-7, 2015 Oct 28.
Article in English | MEDLINE | ID: mdl-26402146

ABSTRACT

A new carbazole-based mononuclear gold(i) complex was designed and synthesized. The novel luminogen shows significative solid-state reversible mechanochromism, dual-responsive thermochromism and sensitive thin-film vapochromism properties. In addition, we obtained two kinds of crystals of the luminogen that may explain these interesting characteristics.


Subject(s)
Carbazoles/chemistry , Gold/chemistry , Organometallic Compounds/chemistry , Models, Molecular , Molecular Conformation
16.
Lasers Med Sci ; 30(3): 1109-15, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25616712

ABSTRACT

Morphological alteration of cells and matrices is critical for tumor initiation and progression. Monitoring these alterations during tumor progression is vitally important for making real-time histological diagnoses of tumor staging. In this study, 20 pairs of normal and cancerous human breast tissues were imaged by multiphoton microscopy (MPM), and nuclear area and collagen density were quantified by LSM 5 software (version 3.2). Comparison of MPM images from normal breast tissue with low- and high-grade invasive ductal carcinoma (IDC) lesions clearly showed changes in both cellular features and extracellular matrix architecture during IDC development. Moreover, analysis of nuclear area and collagen density established a quantitative link between these two morphological features and progression of IDC. Present results demonstrated that MPM can provide both qualitative and quantitative evaluations of tumor progression. With additional development, this technique has the potential to make real-time histological diagnoses of tumor staging and guide development of efficacious clinical therapies.


Subject(s)
Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Adult , Aged , Breast/pathology , Breast Neoplasms/diagnosis , Breast Neoplasms/metabolism , Carcinoma, Ductal, Breast/diagnosis , Carcinoma, Ductal, Breast/metabolism , Collagen/metabolism , Disease Progression , Female , Humans , Microscopy, Fluorescence, Multiphoton , Middle Aged , Neoplasm Staging
17.
Nanoscale ; 6(23): 14538-42, 2014 Nov 06.
Article in English | MEDLINE | ID: mdl-25350922

ABSTRACT

Micrometer-sized single-crystalline In2Se3 nanosheets are synthesized by epitaxial growth from In2Se3nanowires. The In2Se3 nanosheets possess anisotropic structural configuration with intralayer covalent bonding and interlayer van der Waals bonding. Phototransistors based on the In2Se3 nanosheets are realized, and the devices show high photoresponsivity and high photo On/Off ratio up to two orders. The photo-gating effect can be modulated by the gate bias, indicating potential utility of the In2Se3 nanosheets in a variety of optoelectronic applications.

18.
ACS Appl Mater Interfaces ; 6(15): 12429-35, 2014 Aug 13.
Article in English | MEDLINE | ID: mdl-25058566

ABSTRACT

Platinum-based bimetallic nanocatalysts have attracted much attention due to their high-efficiency catalytic performance in energy-related applications such as fuel cell and hydrogen storage, for example, the hydrolytic dehydrogenation of ammonia borane (AB). In this work, a simple and green method has been demonstrated to successfully prepare Pt-M (M = Fe, Co, Ni) NPs with tunable composition (nominal Pt/M atomic ratios of 4:1, 1:1, and 1:4) in aqueous solution under mild conditions. All Pt-M NPs with a small size of 3-5 nm show a Pt fcc structure, suggesting the bimetallic formation (alloy and/or partial core-shell), examined by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray absorption fine structure (XAFS) analysis. The catalytic activities of Pt-M NPs in the hydrolytic dehydrogenation of AB reveal that Pt-Ni NPs with a ratio of 4:1 show the best catalytic activity and even better than that of pure Pt NPs when normalized to Pt molar amount. The Ni oxidation state in Pt-Ni NPs has been suggested to be responsible for the corresponding catalytic activity for hydrolytic dehydrogenation of AB by XAFS study. This strategy for the synthesis of Pt-M NPs is simple and environmentally benign in aqueous solution with the potential for scale-up preparation and the in situ catalytic reaction.

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