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1.
Phytopathology ; 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38831556

ABSTRACT

Fusarium head blight (FHB) caused by Fusarium graminearum is a significant pathogen affecting wheat crops. During the infection process, effector proteins are secreted to modulate plant immunity and promote infection. The toxin deoxynivalenol (DON) is produced in infected wheat grains, posing a threat to human and animal health. Serine carboxypeptidases (SCPs) belong to the α/ß hydrolase family of proteases and are widely distributed in plant and fungal vacuoles as well as animal lysosomes. Research on SCPs mainly focuses on the isolation, purification of a small number of fungi as well as their study in plants.However, their functions in F. graminearum, a fungal pathogen, remain relatively unknown. In this study, the biological functions of the FgSCP gene in F. graminearum were investigated. The study revealed that mutations in FgSCP affected nutritional growth, sexual reproduction, and stress tolerance of F. graminearum. Furthermore, the deletion of FgSCP resulted in reduced pathogenicity and hindered the biosynthesis of DON. The upregulation of FgSCP expression three days after infection indicated its involvement in host invasion, possibly acting as a "smokescreen" to deceive the host and suppress the expression of host defensive genes. Subsequently, we confirmed the secretion ability of FgSCP and its ability to inhibit the cell death induced by INF1 in Nicotiana. benthamiana cells, indicating its potential role as an effector protein in suppressing plant immune responses and promoting infection. In summary, we have identified FgSCP as an essential effector protein in F. graminearum, playing critical roles in growth, virulence, secondary metabolism, and host invasion.

2.
Chem Rev ; 121(2): 649-735, 2021 01 27.
Article in English | MEDLINE | ID: mdl-32667792

ABSTRACT

The successful synthesis of noble-metal nanocrystals with controlled shapes offers many opportunities to not only maneuver their physicochemical properties but also optimize their figures of merit in a wide variety of applications. In particular, heterogeneous catalysis and surface science have benefited enormously from the availability of this new class of nanomaterials as the atomic structure presented on the surface of a nanocrystal is ultimately determined by its geometric shape. The immediate advantages may include significant enhancement in catalytic activity and/or selectivity and substantial reduction in materials cost while providing a well-defined model system for mechanistic study. With a focus on the monometallic system, this review article provides a comprehensive account of recent progress in the development of noble-metal nanocrystals with controlled shapes, in addition to their remarkable performance in a large number of catalytic and electrocatalytic reactions. We hope that this review article offers the impetus and roadmap for the development of next-generation catalysts vital to a broad range of industrial applications.

3.
Acta Pharmacol Sin ; 44(3): 610-621, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36008706

ABSTRACT

Mitochondrial dynamics, including mitochondrial fission and fusion, are critical for maintaining mitochondrial functions. Evidence shows that TANK-binding kinase 1 (TBK1) regulates mitochondrial fusion and fission and then mitophagy. Since a previous study demonstrates a strong correlation between mitophagy and osteoarthritis (OA), we herein investigated the potential role of TBK1 in OA process and mitochondrial functions. We demonstrated a strong correlation between TBK1 and OA, evidenced by significantly downregulated expression of TBK1 in cartilage tissue samples of OA patients and in the chondrocytes of aged mice, as well as TNF-α-stimulated phosphorylation of TBK1 in primary mouse chondrocytes. TBK1 overexpression significantly attenuated TNF-α-induced apoptosis and abnormal mitochondrial function in primary mouse chondrocytes. Furthermore, TBK1 overexpression induced remodeling of mitochondrial morphology by directly phosphorylating dynamin-related protein 1 (DRP1) at Ser637, abolishing the fission of DRP1 and preventing its fragmentation function. Moreover, TBK1 recruitment and DRP1 phosphorylation at Ser637 was necessary for engulfing damaged mitochondria by autophagosomal membranes during mitophagy. Moreover, we demonstrated that APMK/ULK1 signaling contributed to TBK1 activation. In OA mouse models established by surgical destabilization of the medial meniscus, intraarticular injection of lentivirus-TBK1 significantly ameliorated cartilage degradation via regulation of autophagy and alleviation of cell apoptosis. In conclusion, our results suggest that the TBK1/DRP1 pathway is involved in OA and pharmacological targeting of the TBK1-DRP1 cascade provides prospective therapeutic benefits for the treatment of OA.


Subject(s)
Mitochondrial Dynamics , Tumor Necrosis Factor-alpha , Mice , Animals , Phosphorylation , Tumor Necrosis Factor-alpha/metabolism , Autophagy/physiology , Dynamins/metabolism , Protein Serine-Threonine Kinases/metabolism
4.
Phytopathology ; 113(7): 1325-1334, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36774558

ABSTRACT

Somatic embryogenesis receptor kinases (SERKs) belong to the leucine-rich repeat receptor-like kinase (LRR-RLK) subfamily, and many LRR-RLKs have been proven to play a key role in plant immune signal transmission. However, the functions of SERKs in resistance to stripe rust caused by Puccinia striiformis f. sp. tritici remains unknown. Here, we identified a gene, TaSERK1, from Xiaoyan 6, a wheat cultivar possessing high-temperature seedling-plant (HTSP) resistance to the fungal pathogen P. striiformis f. sp. tritici and expresses its resistance at the seedling stage. The expression level of TaSERK1 was upregulated upon P. striiformis f. sp. tritici inoculation under relatively high temperatures. The transcriptional level of TaSERK1 was significantly increased under exogenous salicylic acid and brassinosteroids treatments. The barley stripe mosaic virus-induced gene silencing assay indicated that TaSERK1 positively regulated the HTSP resistance to stripe rust. The transient expression of TaSERK1 in tobacco leaves confirmed its subcellular localization on the plasma membrane. Furthermore, TaSERK1 interacted with and phosphorylated the chaperone protein TaDJA7, which belongs to the heat shock protein 40 subfamily. Silencing TaDJA7 compromised the HTSP resistance to stripe rust. The results indicated that when the membrane immune receptor TaSERK1 perceives the P. striiformis f. sp. tritici infection under relatively high temperatures, it transmits the signal to TaDJA7 to activate HTSP resistance to the pathogen.


Subject(s)
Basidiomycota , Seedlings , Seedlings/genetics , Seedlings/microbiology , Leucine , Temperature , Leucine-Rich Repeat Proteins , Plant Diseases/microbiology , Basidiomycota/physiology
5.
Nano Lett ; 22(9): 3591-3597, 2022 05 11.
Article in English | MEDLINE | ID: mdl-35439017

ABSTRACT

Despite the successful control of crystal phase using template-directed growth, much remains unknown about the underlying mechanisms. Here, we demonstrate that the crystal phase taken by the deposited metal depends on the lateral size of face-centered cubic (fcc)-Pd nanoplate templates with 12 nm plates giving fcc-Ru while 18-26 nm plates result in hexagonal closed-packed (hcp)-Ru. Although Ru overlayers with a metastable fcc- (high in bulk energy) or stable hcp-phase (low in bulk energy) can be epitaxially deposited on the basal planes, the lattice mismatch will lead to jagged hcp- (high in surface energy) and smooth fcc-facets (low in surface energy), respectively, on the side faces. As the proportion of basal and side faces on the nanoplates varies with lateral size, the crystal phase will change depending on the relative contributions from the surface and bulk energies. The Pd@fcc-Ru outperforms the Pd@hcp-Ru nanoplates toward ethylene glycol and glycerol oxidation reactions.


Subject(s)
Nanoparticles , Oxidation-Reduction , Physical Phenomena
6.
Angew Chem Int Ed Engl ; 62(42): e202306906, 2023 Oct 16.
Article in English | MEDLINE | ID: mdl-37528509

ABSTRACT

We report for the first time that Pd nanocrystals can absorb H via a "single-phase pathway" when particles with a proper combination of shape and size are used. Specifically, when Pd icosahedral nanocrystals of 7- and 12-nm in size are exposed to H atoms, the H-saturated twin boundaries can divide each particle into 20 smaller single-crystal units in which the formation of phase boundaries is no longer favored. As such, absorption of H atoms is dominated by the single-phase pathway and one can readily obtain PdHx with anyx in the range of 0-0.7. When switched to Pd octahedral nanocrystals, the single-phase pathway is only observed for particles of 7 nm in size. We also establish that the H-absorption kinetics will be accelerated if there is a tensile strain in the nanocrystals due to the increase in lattice spacing. Besides the unique H-absorption behaviors, the PdHx (x=0-0.7) icosahedral nanocrystals show remarkable thermal and catalytic stability toward the formic acid oxidation due tothe decrease in chemical potential for H atoms in a Pd lattice under tensile strain.

7.
J Am Chem Soc ; 144(6): 2556-2568, 2022 02 16.
Article in English | MEDLINE | ID: mdl-35108015

ABSTRACT

Palladium is one of the few metals capable of forming hydrides, with the catalytic properties being dependent on the elemental composition and spatial distribution of H atoms in the lattice. Herein, we report a facile method for the complete transformation of Pd nanocubes into a stable phase made of PdH0.706 by treating them with aqueous hydrazine at a concentration as low as 9.2 mM. Using formic acid oxidation (FAO) as a model reaction, we systematically investigated the structure-catalytic property relationship of the resultant nanocubes with different degrees of hydride formation. The current density at 0.4 V was enhanced by four times when the nanocubes were completely converted from Pd to PdH0.706. On the basis of a set of slab models with PdH(100) overlayers on Pd(100), we conducted density functional theory calculations to demonstrate that the degree of hybrid formation could influence both the activity and selectivity toward FAO by modulating the relative stability of formate (HCOO) and carboxyl (COOH) intermediates. This work provides a viable strategy for augmenting the performance of Pd-based catalysts toward various reactions without altering the loading of this scarce metal.

8.
Eur J Neurosci ; 55(8): 1895-1916, 2022 04.
Article in English | MEDLINE | ID: mdl-35332602

ABSTRACT

Peripheral nerve injury is a common clinical problem that often leads to significant functional impairment or even complete paralysis. Allograft has been proposed as a potential repair strategy for peripheral nerve injuries. Furthermore, peripheral nerve cryopreservation may result in nearly unlimited supply of grafts. However, the concentration of neurotrophic factors secreted by Schwann cells (SCs) in the local micro-environment after transplantation may not be sufficient for the survival of neuronal soma and axonal regeneration. Here, we investigated the effect of endogenous neurotrophic factors (ENTFs) on nerve regeneration in rats after the allograft of a cryopreserved sciatic nerve. ENTFs were highly expressed in the sciatic nerves pretreated for 14 days. Although the number of surviving cells in the sciatic nerves and their immunogenicity were low in the 14-day group after 4 weeks of cryopreservation, they continued to express high levels of ENTFs in vitro. At 1 week postoperation, the 14-day Allo group showed low plasma levels of interleukin-2, interferon-γ and tumour necrosis factor-alpha and low cellular immune response. At 20 weeks postoperation, nerve regeneration and functional recovery in the 14-day Allo group was similar to that in the fresh isograft group but better than that in the cryopreserved-fresh allograft and fresh allograft groups. Thus, ENTFs were induced in vitro after pretreatment of the sciatic nerve. Following cryopreservation, the sciatic nerves with high levels of ENTFs continued to express high levels of ENTFs in vitro. The immune response after allograft was weak, which promoted recipient nerve regeneration.


Subject(s)
Nerve Regeneration , Peripheral Nerve Injuries , Allografts/transplantation , Animals , Cryopreservation , Nerve Growth Factors/pharmacology , Nerve Regeneration/physiology , Peripheral Nerve Injuries/therapy , Rats , Schwann Cells , Sciatic Nerve/injuries
9.
Phys Chem Chem Phys ; 24(29): 17716-17722, 2022 Jul 27.
Article in English | MEDLINE | ID: mdl-35838540

ABSTRACT

Immigration to Mars, which is expected to be powered mainly by photovoltaics, is one of the greatest dreams of humanity. However, the extreme temperature difference and high-energy cosmic radiation on the surface of Mars make it difficult for conventional photovoltaics to operate steadily over time. With their advantages of being lightweight, having a high irradiation tolerance, and an outstanding power conversion efficiency (PCE), perovskite solar cells (PSCs) have shown themselves to be a promising candidate for Martian applications. In this study, we simulated the low-intensity-low-temperature (LILT) environment of the Mars surface, and monitored the in situ device performance of PSCs. Surprisingly, the device PCE was not only maintained at a high level but was even improved slightly. Further investigation revealed that the self-healing effect of perovskites under LILT conditions could be attributed to the light-induced decomposition of the perovskite film and the ß-phase perovskite recrystallization process at the perovskite/hole transport layer interface. Interfacial ß-phase perovskites are stable at low temperatures, which can facilitate charge extraction and protect the perovskite bulk from long-term light damage. This study demonstrated the feasibility of PSCs and provides a reference for Martian applications.

10.
J Craniofac Surg ; 33(1): 276-278, 2022.
Article in English | MEDLINE | ID: mdl-34967524

ABSTRACT

ABSTRACT: Epidermal or epidermoid cysts are 1 of the most frequent benign masses, they rarely grow to a huge size, and only a few cases have been reported. We report a rare case of a 52-year-old man with giant neoplasm growing invasively in the frontal region, including both intracranial and extracranial extensions, and caused extensive brain deformation and skull lesions. It is worth noting that the patient did not present any significant neurological symptoms and deficits for more than 40 years on admission. A combination of gross total tumor resection and cranioplasty was performed. The patient was satisfied with the results of the surgery, and no evidence of recurrence or complications were found in the 2 years follow-up. The authors reported the case not only to propose the first-stage aesthetic treatment option for this unusual mass on the scalp but also hinted at the vigilance and importance of systematic monitoring of the small skull mass for avoiding the potential risk of tumor progression, malignant transformation, operative trauma, and financial burden.


Subject(s)
Epidermal Cyst , Epidermal Cyst/diagnostic imaging , Epidermal Cyst/surgery , Esthetics, Dental , Humans , Male , Middle Aged , Scalp/surgery , Skull/surgery
11.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 53(4): 583-587, 2022 Jul.
Article in Zh | MEDLINE | ID: mdl-35871727

ABSTRACT

Objective: To assess the efficacy and safety of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) under general anesthesia and to provide the basis for clinical research related to DBS surgeries under general anesthesia. Methods: A total of 60 patients with primary Parkinson's disease who underwent DBS surgery between January 2019 and December 2021at West China Hospital were enrolled for the study. Among them, 30 had the surgery while they were asleep, i.e., under general anesthesia, and 30, while they were awake, i.e., under local anesthesia. All the patients underwent bilateral STN-DBS surgery. Bispectral index (BIS) was used to monitor and control the depth of anesthesia. Microelectrode recording (MER) technology was used to record the characteristic signals of the bilateral subthalamic nuclei and verify their location during the operation. All patients completed the implantation of deep electrodes, connecting wires, and implantable stimulation generator (IPG) at one time. Postoperative thin-slice CT scans were done to reconstruct electrode images and to verify the accuracy of electrode implantation. The Unified Parkinson's Disease Rating Scale-Ⅲ (UPDRS-Ⅲ) was used to evaluate the preoperative vs. postoperative improvement in motor symptoms, and the results of intraoperative MER and the occurrence of surgery-related complications were documented and analyzed. Results: All patients successfully completed the implantation surgery. The electrodes were accurately implanted at the right position and there was no significant difference between the general anesthesia group and the local anesthesia group in UPDRS-Ⅲ scores and medication dosage differences before and after the operation. No intracranial hemorrhage, cerebral infarction, or infection occurred after the operation, and 5 patients had temporary mental and behavioral abnormalities, which disappeared within 48 hours after the operation. Conclusion: The postoperative therapeutic effect of STN-DBS surgery for primary Parkinson's disease under general anesthesia is comparable to that of the traditional STN-DBS surgery under local anesthesia. When the operation is performed under general anesthesia, the incidence of surgery and anesthesia-related complications is low if patients are managed strictly, and patients would also experience improved surgical comfort.


Subject(s)
Deep Brain Stimulation , Parkinson Disease , Subthalamic Nucleus , Anesthesia, General , Deep Brain Stimulation/adverse effects , Deep Brain Stimulation/methods , Humans , Parkinson Disease/drug therapy , Parkinson Disease/surgery , Subthalamic Nucleus/surgery , Treatment Outcome
12.
J Cell Physiol ; 236(6): 4369-4386, 2021 06.
Article in English | MEDLINE | ID: mdl-33164235

ABSTRACT

The inflammatory environment and excessive chondrocyte apoptosis have been demonstrated to play crucial roles in the onset of osteoarthritis (OA). Hydrogen sulfide (H2 S), a gaseous signalling molecule, exerts an inhibitory effect on inflammation and apoptosis in several degenerative diseases. However, the protective effect of H2 S against OA has not been fully clarified, and its underlying mechanism should be examined further. In the current study, the role of endogenous H2 S in the pathogenesis of OA and its protective effects on interleukin (IL)-1ß-induced chondrocytes were identified. Our data revealed decreased H2 S expression in both human degenerative OA cartilage tissue and IL-1ß-induced chondrocytes. Pretreatment with the H2 S donor sodium hydrosulfide (NaHS) dramatically attenuated IL-1ß-induced overproduction of inflammatory cytokines and improved the balance between anabolic and catabolic chondrocyte capacities, and these effects were dependent on PI3K/AKT pathway-mediated inhibition of nuclear factor kappa B (NF-κB). Moreover, mitochondrial dysfunction-related apoptosis was significantly reversed by NaHS in IL-1ß-stimulated chondrocytes. Mechanistically, NaHS partially suppressed IL-1ß-induced phosphorylation of the mitogen-activated protein kinase (MAPK) cascades. Furthermore, in the destabilization of the medial meniscus mouse model, OA progression was ameliorated by NaHS administration. Taken together, these results suggest that H2 S may antagonize IL-1ß-induced inflammation and mitochondrial dysfunction-related apoptosis via selective suppression of the PI3K/Akt/NF-κB and MAPK signalling pathways, respectively, in chondrocytes and may be a potential therapeutic agent for the treatment of OA.


Subject(s)
Antirheumatic Agents/pharmacology , Apoptosis/drug effects , Chondrocytes/drug effects , Hydrogen Sulfide/pharmacology , Inflammation Mediators/metabolism , Interleukin-1beta/toxicity , Joints/drug effects , Mitochondria/drug effects , Osteoarthritis/drug therapy , Sulfides/pharmacology , Aged , Animals , Antirheumatic Agents/metabolism , Case-Control Studies , Cells, Cultured , Chondrocytes/immunology , Chondrocytes/metabolism , Chondrocytes/pathology , Disease Models, Animal , Female , Humans , Hydrogen Sulfide/metabolism , Joints/immunology , Joints/metabolism , Joints/pathology , Male , Mice, Inbred C57BL , Middle Aged , Mitochondria/immunology , Mitochondria/metabolism , Mitochondria/pathology , Mitogen-Activated Protein Kinases/metabolism , NF-kappa B/metabolism , Osteoarthritis/immunology , Osteoarthritis/metabolism , Osteoarthritis/pathology , Phosphatidylinositol 3-Kinase/metabolism , Phosphorylation , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Sulfides/metabolism
13.
J Am Chem Soc ; 143(16): 6293-6302, 2021 04 28.
Article in English | MEDLINE | ID: mdl-33852314

ABSTRACT

We report the synthesis of Rh nanocrystals with different shapes by controlling the kinetics involved in the growth of preformed Rh cubic seeds. Specifically, Rh nanocrystals with cubic, cuboctahedral, and octahedral shapes can all be obtained from the same cubic seeds under suitable reduction kinetics for the precursor. The success of such a synthesis also relies on the use of a halide-free precursor to avoid oxidative etching, as well as the involvement of a sufficiently high temperature to remove Br- ions from the seeds while ensuring adequate surface diffusion. The availability of Rh nanocrystals with cubic and octahedral shapes allows for an evaluation of the facet dependences of their thermal and catalytic properties. The data from in situ electron microscopy studies indicate that the cubic and octahedral Rh nanocrystals can keep their original shapes up to 700 and 500 °C, respectively. When tested as catalysts for hydrazine decomposition, the octahedral nanocrystals exhibit almost 4-fold enhancement in terms of H2 selectivity relative to the cubic counterpart. As for ethanol oxidation, the order is reversed, with the cubic nanocrystals being about three times more active than the octahedral sample.

14.
Chemistry ; 27(55): 13855-13863, 2021 Oct 01.
Article in English | MEDLINE | ID: mdl-34314521

ABSTRACT

Colloidal synthesis of metal nanocrystals with controlled shapes and internal structures calls for a tight control over both the nucleation and growth processes. Here we report a method for the facile synthesis of Pt right bipyramids (RBPs) by separating nucleation from growth and controlling the nucleation step in a continuous flow reactor. Specifically, homogeneous nucleation was thermally triggered by introducing the reaction solution into a tubular flow reactor held at an elevated temperature to generate singly-twinned seeds. At a lower temperature, the singly-twinned seeds were protected from oxidative etching to allow their slow growth and evolution into RBPs while additional nucleation of undesired seeds could be largely suppressed to ensure RBPs as the main product. Further investigation indicated that the internal structure and growth pattern of the seeds were determined by the temperatures used for the nucleation and growth steps, respectively. The Br- ions involved in the synthesis also played a critical role in the generation of RBPs by serving as a capping agent for the Pt{100} facets while regulating the reduction kinetics through coordination with the Pt(IV) ions.


Subject(s)
Metal Nanoparticles , Platinum , Ions , Kinetics , Oxidation-Reduction
15.
Chem Rev ; 119(15): 8972-9073, 2019 08 14.
Article in English | MEDLINE | ID: mdl-30854849

ABSTRACT

This Review offers a comprehensive review of the colloidal synthesis, mechanistic understanding, physicochemical properties, and applications of one-dimensional (1D) metal nanostructures. After a brief introduction to the different types of 1D nanostructures, we discuss major concepts and methods typically involved in a colloidal synthesis of 1D metal nanostructures, as well as the current mechanistic understanding of how the nanostructures are formed. We then highlight how experimental studies and computational simulations have expanded our knowledge of how and why 1D metal nanostructures grow. Following specific examples of syntheses for monometallic, multimetallic, and heterostructured systems, we showcase how the unique structure-property relationships of 1D metal nanostructures have enabled a broad spectrum of applications, including sensing, imaging, plasmonics, photonics, display, thermal management, and catalysis. Throughout our discussion, we also offer perspectives with regard to the future directions of development for this class of nanomaterials.

16.
Phytother Res ; 35(10): 5694-5707, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34423505

ABSTRACT

Morin is a natural compound isolated from moraceae family members and has been reported to possess a range of pharmacological activities. However, the effects of morin on bone-associated disorders and the potential mechanism remain unknown. In this study, we investigated the anti-osteoclastogenic effect of morin in vitro and the potential therapeutic effects on ovariectomy (OVX)-induced osteoporosis in vivo. In vitro, by using a bone marrow macrophage-derived osteoclast culture system, we determined that morin attenuated receptor activator of nuclear factor (NF)-κB ligand (RANKL)-induced osteoclast formation via the inhibition of the mitogen-activated protein kinase (MAPK), NF-κB and calcium pathways. In addition, the subsequent expression of nuclear factor of activated T cells c1 (NFATc1) and c-fos was significantly suppressed by morin. In addition, NFATc1 downregulation led to the reduced expression of osteoclastogenesis-related marker genes, such as V-ATPase-d2 and Integrin ß3. In vivo, results provided that morin could effectively attenuate OVX-induced bone loss in C57BL/6 mice. In conclusion, our results demonstrated that morin suppressed RANKL-induced osteoclastogenesis via the NF-κB, MAPK and calcium pathways, in addition, its function of preventing OVX-induced bone loss in vivo, which suggested that morin may be a potential therapeutic agent for postmenopausal osteoporosis treatment.


Subject(s)
Bone Resorption , Osteoclasts , Animals , Calcium , Cell Differentiation , Female , Flavonoids , Mice , Mice, Inbred C57BL , Mitogen-Activated Protein Kinases , NF-kappa B , NFATC Transcription Factors , Osteogenesis , RANK Ligand
17.
Angew Chem Int Ed Engl ; 60(36): 19643-19647, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-34128305

ABSTRACT

We report a simple route based upon seed-mediated growth to the synthesis of Pd@Aux Pd1-x (0.8≤x≤1) core-shell nanocubes. Benefiting from the well-defined {100} facets and an optimal Au/Pd ratio for the surface, the nanocubes bearing a shell made of Au0.95 Pd0.05 work as an efficient electrocatalyst toward H2 O2 production, with high selectivity of 93-100 % in the low-overpotential region of 0.4-0.7 V. When the Au0.95 Pd0.05 alloy is confined to a shell of only three atomic layers in thickness, the electrocatalyst is able to maintain its surface structure and elemental composition, endowing continuous and stable production of H2 O2 during oxygen reduction at a high rate of 1.62 mol g(Pd+Au) -1  h-1 . This work demonstrates a versatile route to the rational development of active and durable electrocatalysts based upon alloy nanocrystals.

18.
Chemistry ; 26(61): 13890-13895, 2020 Nov 02.
Article in English | MEDLINE | ID: mdl-32459866

ABSTRACT

In order to maximize the performance of nanocrystals in a specific application, it is necessary to control both their size and shape. Here we report a one-pot protocol that allows us to separate growth from nucleation for achieving better control over the size and shape of Pd nanocrystals. The two processes are temporally separated from each other, although the synthesis is carried out in the same reaction container. Size control is achieved by simply varying the ratio between the amounts of precursor allocated to the growth and nucleation processes. With the involvement of seeds at a fixed number, increasing the amount of precursor for growth leads to increasingly larger nanocrystals. Shape control is made possible by varying the capping agent, with bromide leading to a cubic shape and citrate inducing the formation of an octahedral shape. The synthesis can also be scaled up by at least tenfold without compromising the quality.

19.
Eur Spine J ; 29(4): 786-793, 2020 04.
Article in English | MEDLINE | ID: mdl-32112152

ABSTRACT

PURPOSE: No study so far has paid attention to strabismus-related spinal imbalance. This study aimed to determine the epidemiology of thoracic scoliosis in children and adolescents with strabismus and investigate the association of two diseases. METHODS AND DESIGN: A cross-sectional study. Study group consists of 1935 consecutive candidates for strabismus surgery (4-18 years); Control group consists of the age- and sex-matched patients with respiratory diseases. All subjects underwent a screening program based on chest plain radiographs using the Cobb method. Their demographic information, clinical variables and results of Cobb angle were recorded and analyzed. RESULTS: A significantly higher prevalence of thoracic scoliosis (289/1935, 14.94% versus 58/1935, 3.00%) was found in study group compared with control group. Among strabismic patients, the coronal thoracic scoliosis curve mainly distributed in right and in main thoracic (198/289) and in the curves 10°-19° (224/289); Age range 7-9 years (103/1935), female (179/1935) and concomitant exotropia patients (159/851) were more likely to have thoracic scoliosis. According to the logistic regression, thoracic scoliosis had no significant association with age, BMI, duration of illness and onset age (p > 0.05). However, gender, BCVA, type of strabismus and degree of strabismus showed a significant relationship with the prevalence of thoracic scoliosis (p < 0.05). CONCLUSIONS: With a pooled prevalence of 14.94%, strabismus patients showed a great higher risk of developing thoracic scoliosis. Screening for scoliosis in strabismus patients can be helpful to discover a high prevalence of potential coronal scoliosis. More attention should be paid to ophthalmological problems in patients with scoliosis. These slides can be retrieved under Electronic Supplementary Material.


Subject(s)
Scoliosis , Spinal Fusion , Strabismus , Adolescent , Child , China/epidemiology , Cross-Sectional Studies , Female , Humans , Male , Prevalence , Scoliosis/diagnostic imaging , Scoliosis/epidemiology , Scoliosis/surgery , Strabismus/epidemiology , Strabismus/surgery , Thoracic Vertebrae/diagnostic imaging , Thoracic Vertebrae/surgery , Treatment Outcome
20.
Angew Chem Int Ed Engl ; 59(43): 19129-19135, 2020 Oct 19.
Article in English | MEDLINE | ID: mdl-32706132

ABSTRACT

We report a robust method for effectively removing the chemisorbed Br- ions, a capping agent, from the surface of Pd nanocubes to maximize their catalytic activity. The Br- ions can be removed by simply heating the sample in water, but the desorption of Br- ions will expose the underneath Pd atoms to the O2 from air for the formation of a relatively thick oxide layer. During potential cycling, the oxide layer evolves into detrimental features such as steps and terraces. By introducing a trace amount of hydrazine into the system, the Br- ions can be removed by heating without forming a thick oxide layer. The as-cleaned nanocubes show greatly enhanced activity toward formic acid oxidation. This cleaning method can also remove Br- ions from Rh nanocubes and it is expected to work for other combinations of nanocrystals and capping agents.

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