Overexpression of transcription factor FaMYB63 enhances salt tolerance by directly binding to the SOS1 promoter in Arabidopsis thaliana.

Salinity is a pivotal abiotic stress factor with far-reaching consequences on global crop growth, yield, and quality and which includes strawberries. R2R3-MYB transcription factors encompass a range of roles in plant development and responses to abiotic stress. In this study, we identified that strawberry transcription factor FaMYB63 exhibited a significant upregulation in its expression under salt stress conditions. An analysis using yeast assay demonstrated that FaMYB63 exhibited the ability to activate transcriptional activity. Compared with those in the wild-type (WT) plants, the seed germination rate, root length, contents of chlorophyll and proline, and antioxidant activities (SOD, CAT, and POD) were significantly higher in FaMYB63-overexpressing Arabidopsis plants exposed to salt stress. Conversely, the levels of malondialdehyde (MDA) were considerably lower. Additionally, the FaMYB63-overexpressed Arabidopsis plants displayed a substantially improved capacity to scavenge active oxygen. Furthermore, the activation of stress-related genes by FaMYB63 bolstered the tolerance of transgenic Arabidopsis to salt stress. It was also established that FaMYB63 binds directly to the promoter of the salt overly sensitive gene SOS1, thereby activating its expression. These findings identified FaMYB63 as a possible and important regulator of salt stress tolerance in strawberries.

Midterm Outcomes of Multicenter Castor Single-Branch Stent Graft Use in the Treatment of Thoracic Aortic Diseases.

PURPOSE: The aim of this study was to evaluate the midterm efficacy and safety of a single-branch Castor stent graft in the treatment of thoracic aortic disease. MATERIALS AND METHODS: Clinical data of 106 patients with thoracic aortic disease treated with Castor single-branch stent graft at 3 centers were collected between May 2018 and June 2023. The indicators included technical success, stent-related complication, reintervention, retrograde dissection, endoleak, distal stent graft-induced entry (dSINE), branch patency, and mortality. The outcomes of the Castor stent graft for multibranch reconstruction above the arch was also analyzed. RESULTS: The technical success was 98.1% (104/106), while the surgical success was 93.4% (99/106). The reintervention was 2.8% (3/106), consisting of a case of retrograde type A dissection, an endoleak, and a dSINE. The retrograde dissection was 1.9% (2/106), while type I endoleak was 1.9% (2/106). The new dSINE was 2.8% (3/106), and the branch patency rate was 100%. The mortality was 1.9% (2/106). The mean follow-up time was 29.1±17.7 months. The 2-year post-surgery cumulative survival rate was 91.0%±3.1%, while the cumulative branch patency rate was 96.2%±2.2%. In addition, the cumulative freedom from stent-related reintervention rate was 93.2%±2.8%. A comparison showed no significant difference in the stent-related complication, branch patency, endoleak, reintervention, and mortality when the proximal end of the Castor stent graft was anchored to zones 1 or 2 of the aorta. CONCLUSION: Castor single-branch stent graft showed favorable early and midterm outcomes in the treatment of thoracic aortic disease. In addition, it was feasible to combine Castor stent graft with other advanced techniques for multibranch aortic arch reconstruction. CLINICAL IMPACT: The Castor single-branch stent graft was approval by the Chinese Food and Drug Administration in 2017. However, there were few studies on the mid-term outcomes for thoracic aortic disease after launching, which mainly focused on small single-center retrospective study. In the study, we assessed the mid-term outcomes of Castor stent graft through multi-center cases, Castor stent graft combined with other advanced techniques (such as fenestration and hybrid) for multi-branch reconstruction of aortic arch were also conducted. We found Castor single-branch stent graft showed favorable early and mid-term outcomes in the treatment of thoracic aortic disease. Additionally, it was feasible to combine Castor stent graft with other advanced technique for multi-branch aortic arch reconstruction. As an off-the-shelf branched stent graft with a wide range of models, it could be also used in most emergent situation. The Castor stent graft was expected to become more widely used in the future.

SeMet alleviates AFB1-induced oxidative stress and apoptosis in rabbit kidney by regulating Nrf2//Keap1/NQO1 and PI3K/AKT signaling pathways.

The purpose of this study was to explore the protective effect of SeMet on renal injury induced by AFB1 in rabbits and its molecular mechanism. Forty rabbits of 35 days old were randomly divided into control group, AFB1 group (0.3 mg AFB1/kg b.w), 0.2 mg/kg Se + AFB1 group (0.3 mg AFB1/kg b.w + 0.2 mg SeMet/kg feed) and 0.4 mg/kg Se + AFB1 group (0.3 mg AFB1/kg b.w + 0.4 mg SeMet/kg feed). The SeMet treatment group was fed different doses of SeMet diets every day for 21 days. On the 17-21 day, the AFB1 treatment group, the 0.2 mg/kg Se + AFB1 group and the 0.4 mg/kg Se + AFB1 group were administered 0.3 mg AFB1 /kg b.w by gavage (dissolved in 0.5 ml olive oil) respectively. The results showed that AFB1 poisoning resulted in the changes of renal structure, the increase of renal coefficient and serum biochemical indexes, the ascent of ROS and MDA levels, the descent of antioxidant enzyme activity, and the significant down-regulation of Nrf2, HO-1 and NQO1. Besides, AFB1 poisoning increased the number of renal apoptotic cells, rised the levels of PTEN, Bax, Caspase-3 and Caspase-9, and decreased the levels of PI3K, AKT, p-AKT and Bcl-2. In summary, SeMet was added to alleviate the oxidative stress injury and apoptosis of kidney induced by AFB1, and the effect of 0.2 mg/kg Se + AFB1 is better than 0.4 mg/kg Se + AFB1.

The R2R3-MYB transcription factor FaMYB63 participates in regulation of eugenol production in strawberry.

The biosynthetic pathway of volatile phenylpropanoids, including 4-allyl-2-methoxyphenol (eugenol), has been investigated in petunia (Petunia hybrida). However, the regulatory network for eugenol accumulation in strawberry (Fragaria × ananassa Duch.) fruit remains unclear. Here, an R2R3-type MYB transcription factor (TF; FaMYB63) was isolated from strawberry by yeast one-hybrid (Y1H) screening using the promoter of the FaEGS1 (eugenol synthase 1 [EGS 1]) gene, which encodes the enzyme responsible for the last step in eugenol biosynthesis. FaMYB63 is phylogenetically distinct from other R2R3-MYB TFs, including FaEOBІІ (EMISSION OF BENZENOID II [EOBII]), which also participates in regulating eugenol biosynthesis in strawberry receptacles. Reverse transcription quantitative PCR (RT-qPCR) assays showed that the expression of FaMYB63 was tissue-specific and consistent with eugenol content through strawberry fruit development, was repressed by abscisic acid, and was activated by auxins (indole-3-acetic acid). Overexpression and RNA interference-mediated silencing of FaMYB63 resulted in marked changes in the transcript levels of the biosynthetic genes FaEGS1, FaEGS2, and FaCAD1 (cinnamyl alcohol dehydrogenase 1 [CAD1]) and, thereby, the accumulation of eugenol. Electrophoretic mobility shift, Y1H, GUS activity, and dual-luciferase activity assays demonstrated that the transcript levels of FaEOBІІ and FaMYB10 were regulated by FaMYB63, but not the other way around. Together, these results demonstrate that FaMYB63 directly activates FaEGS1, FaEGS2, FaCAD1, FaEOBІІ, and FaMYB10 to induce eugenol biosynthesis during strawberry fruit development. These findings deepen the understanding of the regulatory network that influences eugenol metabolism in an edible fruit crop.

Antiadhesion Superhydrophobic Bipolar Electrocoagulation Tweezers with High Conductivity and Stability.

Irregularly shaped electrosurgical devices face significant challenges in electrosurgery due to serious blood and tissue adhesion. Superhydrophobic surfaces inspired by lotus leaves have attracted great attention for their promising antiadhesion properties. However, there are few methods for efficiently preparing superhydrophobic irregularly shaped bipolar electrocoagulation tweezers (BETs). Herein, we propose a simple and environmentally friendly method to fabricate antiadhesion superhydrophobic surfaces on BETs. The superhydrophobicity is obtained by combining laser texturing to form rough structures and low surface energy modification via stearic acid. The formation mechanism of superhydrophobicity is investigated through analyzing microstructures and chemical compositions by scanning electron microscopy, white-light interferometry, and X-ray photoelectron spectroscopy. The functionalized BET surfaces exhibit excellent water repellency with a contact angle of 159.6°, a roll-off angle of 1°, and a surface energy of 14.3 mJ/m2, possessing excellent antiadhesion properties against blood, chicken breast tissue, and pork tissue. Compared with ordinary BETs, the mass of blood, pork tissue, and chicken breast tissue adhered to the superhydrophobic BET is reduced by 97.70, 70.34, and 75.35%, respectively. Moreover, the superhydrophobic BETs have excellent conductivity and maintain good antiadhesion properties after low-temperature storage for 2 weeks, after being impacted by sand and blood and 30 cycles of tape peeling tests. With outstanding antiadhesion performance, the superhydrophobic BET may have promising application prospects in the electrosurgery field.

Systematic Review and Meta-analysis of Short-term and Mid-term Outcomes After Use of t-Branch Off-the-shelf Multibranched Endograft for Elective and Urgent Treatment of Thoracoabdominal Aortic Aneurysms.

OBJECTIVE: To conduct a meta-analysis to assess the safety and efficacy of t-Branch off-the-shelf multibranched endograft for the treatment of thoracoabdominal aortic aneurysm (TAAA). DATA SOURCES: PubMed, Embase, and Web of Science. REVIEW METHODS: Online databases were searched from June 2012 to March 2023. The data were pooled together using a random-effects model of proportions. The outcomes overall included technical success, spinal cord ischemia, target vessel occlusion, type I or III endoleak, reintervention, early mortality (30-day), and mid-term outcomes. Subgroup meta-analyses and meta-regression were performed to explore variation among studies. RESULTS: A total of 15 studies containing 1238 patients were included in the meta-analysis. The overall study quality assessment was found to be moderate to good. The pooled technical success was 97.0% (95% confidence interval [CI]=95.5-98.6, I2=53.01%, 1185/1238 cases, 15 studies). Overall, early mortality was 7.3% (95% CI=4.4-10.1, I2=74.48%, 124/1238 cases, 15 studies). Early spinal cord ischemia was 13.4% (95% CI=9.6-17.2, I2=67.24%, 160/1238 cases, 15 studies), and early type I or III endoleak was 6.0% (95% CI=3.4-8.5, I2=53.71%, 68/1032 cases, 9 studies). Mid-term outcomes showed target vessel occlusion was 4% (95% CI=1.4-6.5, I2=65.18%, 28/528 cases, 10 studies, 5-21.2 months), type I or III endoleak was 4.7% (95% CI=2-7.5, I2=49.74%, 38/512 cases, 10 studies, 5-21.2 months), reintervention was 11.2% (95% CI=8.1-14.3, I2=31.06%, 85/650 cases, 10 studies, 5-21.2 months), and pooled mortality was 13.9% (95% CI=7.2-20.7, I2=76.32%, 84/550 cases, 11 studies, 5-21.2 months). Meta-regression found a significant linear association between higher technical success and earlier publication year (p=0.014) and studies with anatomic inclusion criteria (p=0.037). Urgent patients (p=0.021) and later publication year (p=0.048) were significantly associated with higher early mortality. CONCLUSION: The use of the off-the-shelf t-Branch multibranched endograft for elective or urgent endovascular TAAA repair is associated with high technical success rates and proved to be safe and effective at early and mid-term follow-up. However, the heterogeneity between the included studies is high, and prospective, randomized studies along with future larger studies with long-term follow-up are needed. CLINICAL IMPACT: The Zenith t-Branch (Cook Medical, Bloomington, Ind) was approved as a commercially available device in Europe in June 2012. Although a decade has past, the outcomes of t-Branch have rarely been synthesized at the global level. This meta-analysis included 15 studies containing 1238 patients. The meta-analyses included technical success, major adverse events, reintervention, early mortality, and mid-term outcomes. The outcome was very meaningful and representative for the use of t-Branch. It is helpful for endovascular surgeons to make decisions on the treatment of TAAA patients.

Extracellular proteolytic cascade in tomato activates immune protease Rcr3.

Proteolytic cascades regulate immunity and development in animals, but these cascades in plants have not yet been reported. Here we report that the extracellular immune protease Rcr3 of tomato is activated by P69B and other subtilases (SBTs), revealing a proteolytic cascade regulating extracellular immunity in solanaceous plants. Rcr3 is a secreted papain-like Cys protease (PLCP) of tomato that acts both in basal resistance against late blight disease (Phytophthora infestans) and in gene-for-gene resistance against the fungal pathogen Cladosporium fulvum (syn. Passalora fulva) Despite the prevalent model that Rcr3-like proteases can activate themselves at low pH, we found that catalytically inactive proRcr3 mutant precursors are still processed into mature mRcr3 isoforms. ProRcr3 is processed by secreted P69B and other Asp-selective SBTs in solanaceous plants, providing robust immunity through SBT redundancy. The apoplastic effector EPI1 of P. infestans can block Rcr3 activation by inhibiting SBTs, suggesting that this effector promotes virulence indirectly by preventing the activation of Rcr3(-like) immune proteases. Rcr3 activation in Nicotiana benthamiana requires a SBT from a different subfamily, indicating that extracellular proteolytic cascades have evolved convergently in solanaceous plants or are very ancient in the plant kingdom. The frequent incidence of Asp residues in the cleavage region of Rcr3-like proteases in solanaceous plants indicates that activation of immune proteases by SBTs is a general mechanism, illuminating a proteolytic cascade that provides robust apoplastic immunity.

Road-Network-Map-Assisted Vehicle Positioning Based on Pose Graph Optimization.

Satellite signals are easily lost in urban areas, which causes difficulty in vehicles being located with high precision. Visual odometry has been increasingly applied in navigation systems to solve this problem. However, visual odometry relies on dead-reckoning technology, where a slight positioning error can accumulate over time, resulting in a catastrophic positioning error. Thus, this paper proposes a road-network-map-assisted vehicle positioning method based on the theory of pose graph optimization. This method takes the dead-reckoning result of visual odometry as the input and introduces constraints from the point-line form road network map to suppress the accumulated error and improve vehicle positioning accuracy. We design an optimization and prediction model, and the original trajectory of visual odometry is optimized to obtain the corrected trajectory by introducing constraints from map correction points. The vehicle positioning result at the next moment is predicted based on the latest output of the visual odometry and corrected trajectory. The experiments carried out on the KITTI and campus datasets demonstrate the superiority of the proposed method, which can provide stable and accurate vehicle position estimation in real-time, and has higher positioning accuracy than similar map-assisted methods.

Analysis of Viral Spike Protein N-Glycosylation Using Ultraviolet Photodissociation Mass Spectrometry.

Characterization of protein glycosylation by tandem mass spectrometry remains challenging owing to the vast diversity of oligosaccharides bound to proteins, the variation in monosaccharide linkage patterns, and the lability of the linkage between the glycan and protein. Here, we have adapted an HCD-triggered-ultraviolet photodissociation (UVPD) approach for the simultaneous localization of glycosites and full characterization of both glycan compositions and intersaccharide linkages, the latter provided by extensive cross-ring cleavages enabled by UVPD. The method is applied to study glycan compositions based on analysis of glycopeptides from proteolytic digestion of recombinant human coronaviruse spike proteins from SARS-CoV-2 and HKU1. UVPD reveals unique intersaccharide linkage information and is leveraged to localize N-linked glycoforms with confidence.

Regeneration of Free Reducing Glycans from Reductive Amination-Tagged Glycans by Oxone.

Glycans are usually fluorescently tagged by reductive amination for analytic tools. However, free reducing glycan regeneration is sometimes important and necessary for further structural or functional studies. Here, we introduce a new method for efficiently removing fluorescent tags from glycoconjugates by a simple treatment with Oxone. This method is proven to be fast and general after being tested on a series of common saccharides and widely used tags. We successfully achieved N-glycopeptide synthesis by using the regenerated glycans.

[A new phloroglucinol from Dryopteris fragrans and its antibacterial activity in vitro].

A new phloroglucinol was isolated from 50% ethanol extract of Dryopteris fragrans by silica gel column chromatography, Sephadex LH-20 gel column chromatography, thin-layer chromatography(TLC), and preparative liquid column chromatography. On the basis of MS, ~1H-NMR, ~(13)C-NMR, and reference materials, compound 1 was identified as 2,5-cyclohexadien-1-one, 2-{[2,6-dihydroxy-4-methoxy-3-methyl-5-(1-isobutyl)phenyl]methyl}-3,5-dihydroxy-4,4-dimethyl-6-(1-oxobutyl)(1), and named disaspidin BB. Compound 1 was evaluated for its antibacterial activity. The experimental results showed that compared with the commonly used topical antibiotics erythromycin or mupirocin, disaspidin BB exhibited significant antibacterial activities against Staphylococcus epidermidis(SEP), S. haemolyticus(SHA), and methicillin-resistant S. aureus(MRSA)(P<0.05). Additionally, disaspidin BB was sensitive to ceftazidime-resistant SEP1-SEP4, SHA5-SHA7, MRSA8, and MRSA9. The MIC values of disaspidin BB against SEP and SHA were 1.67-2.71 µg·mL~(-1) and 10.00-33.33 µg·mL~(-1) respectively. Disaspidin BB has good antibacterial activities and deserves development as a new anti-infective drug for external use.

Streamlined Subclass-Specific Absolute Quantification of Serum IgG Glycopeptides Using Synthetic Isotope-Labeled Standards.

Absolute glycoproteomics quantification has drawn tremendous attention owing to its prospects in biomarker discovery and clinical implementation but is impeded by a general lack of suitable heavy isotope-labeled glycopeptide standards. In this study, we devised a facile chemoenzymatic strategy to synthesize a total of 36 human IgG glycopeptides attached with well-defined glycoforms, including 15 isotope-labeled ones with a mass increment of 6 Da to their native counterparts. Spiking of these standards into human sera enabled simplified, robust, and precise absolute quantification of IgG glycopeptides in a subclass-specific fashion. Additionally, the implementation of the absolute quantification approach revealed subclass-dependent alteration of serum IgG galactosylation and sialylation in colon cancer samples.

FvMYB24, a strawberry R2R3-MYB transcription factor, improved salt stress tolerance in transgenic Arabidopsis.

Salinity is one of the major environmental stresses that limit crop growth and productivity. In this study, the FvMYB24 gene that encodes an R2R3-type MYB transcription factor was cloned and characterized. An expression analysis showed that FvMYB24 had a tissue- and stage-specific profile and was induced by salt treatment. Arabidopsis plants that overexpressed transgenic FvMYB24 exhibited a higher germination rate, fresh weight, chlorophyll content, and longer root length than the wild type (WT) under salt stress. The transgenic plants had higher activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) and the accumulation of proline, while these plants accumulated lower amounts of malondialdehyde (MDA) compared with the WT. Furthermore, our results also revealed that the overexpression of FvMYB24 up-regulated the expression of several stress-related genes (AtSOS1, AtSOS2, AtSOS3, AtSOD, AtPOD, AtCAT1, AtNHX1, and AtLEA3) in response to salt stress, thus, enhancing the tolerance of transgenic Arabidopsis. An analysis of the cis-acting elements in the SOS1, SOS2, and SOS3 promoters revealed MYB-binding sites. However, FvMYB24 could only bind to the SOS1 promoter to mediate salt tolerance but not to the SOS2 and SOS3 promoters. These findings suggest that FvMYB24 could potentially be used as a positive regulator in transgenic plant breeding to improve the tolerance of strawberry plants to salt.

Cleavage of a pathogen apoplastic protein by plant subtilases activates host immunity.

The plant apoplast is a harsh environment in which hydrolytic enzymes, especially proteases, accumulate during pathogen infection. However, the defense functions of most apoplastic proteases remain largely elusive. We show here that a newly identified small cysteine-rich secreted protein PC2 from the potato late blight pathogen Phytophthora infestans induces immunity in Solanum plants only after cleavage by plant apoplastic subtilisin-like proteases, such as tomato P69B. A minimal 61 amino acid core peptide carrying two key cysteines, conserved widely in most oomycete species, is sufficient for PC2-induced cell death. Furthermore, we showed that Kazal-like protease inhibitors, such as EPI1, produced by P. infestans prevent PC2 cleavage and dampen PC2 elicited host immunity. This study reveals that cleavage of pathogen proteins to release immunogenic peptides is an important function of plant apoplastic proteases.

Self-supported nickel sulfide derived from nickel foam for hydrogen evolution and oxygen evolution reaction: effect of crystal phase switching.

Designing and fabricating economically viable, high active and stable electrocatalysts play an important role for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Crystal phase is the crucial factor that governs the electrochemical property and electrocatalytic reaction pathways. Here, a one-step nickel foam derived sulfidation method was presented to synthesize self-supported NiS2 and Ni3S2. The crystal phase-dependent chemical properties related to electrocatalytic behavior were evaluated by a series of advanced characterization and density functional theory calculations. Overall, the self-supported Ni3S2 shows high electrochemical activity towards both HER and OER in alkaline conditions, which afford the current density of 10 mA cm-2 with overpotentials of 245 mV for OER and 123 mV for HER, respectively. When employed the self-supported Ni3S2 as the bifunctional electrocatalysts for overall water splitting, the entire device provides the current density of 10 mA cm-2 at 1.61 V. These results indicate that the electrocatalytic properties can be exert greater improved by controlling the crystal phase, offering the prospect for advanced materials design and development.

Structural, elastic and electronic properties of atomically thin pyridyne: theoretical predictions.

In this paper, we propose a new acetylenic carbon material called pyridyne, which is composed of acetylenic linkages and pyridine rings. From first-principles calculations, we investigate the structural, elastic and electronic properties of pyridyne. It is found that the structure of pyridyne is stable at 300 K and its stability is comparable to experimentally synthesized graphdiyne and graphtetrayne. Compared with graphene or graphyne, pyridyne possesses more diverse pores and reduced delocalization of electrons. The in-plane stiffness of pyridyne is 183 N m-1 with a Poisson's ratio of 0.304. Pyridyne is found to be a semiconductor with a direct band gap of 0.91 eV. The intrinsic electron mobility can reach 6.08 × 104 cm2 V-1 s-1, while the hole mobility can reach 1.82 × 104 cm2 V-1 s-1.

Hydrophobic ion-pairing assembled liposomal Rhein with efficient loading for acute pancreatitis treatment.

AIM: The present study aimed to develop liposomal Rhein by employing a hydrophobic ion-pairing technique (HIP) for improved pancreatitis therapy. METHODS: F127 modified liposomal Rhein (F127-RPC-Lip) was prepared using a two-step process consisting of complexation first, followed by a film-ultrasonic dispersion step. The drug-phospholipid interaction was characterised by FT-IR and P-XRD. Particle size and morphology were investigated using DLS and TEM, respectively. Biodistribution and therapeutic efficacy of F127-RPC-Lip were evaluated in a rat model of acute pancreatitis. RESULTS: F127-RPC-Lip achieved efficient drug encapsulation after complexation with lipids through non-covalent interactions and had an average hydrodynamic diameter of about 141 nm. F127-RPC-Lip demonstrated slower drug release (55.90 ± 3.60%, w/w) than Rhein solution (90.27 ± 5.11%) within 24 h. Compared with Rhein, F127-RPC-Lip exhibited prolonged systemic circulation time, superior drug distribution, and attenuated injury in the pancreas of rats post-injection. CONCLUSIONS: HIP-assembled liposomes are a promising strategy for Rhein in treating pancreatitis.

Distribution of systemically administered nanoparticles during acute pancreatitis: effects of particle size and disease severity.

Nanoparticles (NPs) promise to address current limitations for treating acute pancreatitis (AP) via inflammatory cell-mediated sequestration. However, very few studies have explored the influence of NP size on their behavior in different stages of AP. The present work investigated the biodistribution of IR780 loaded mesoporous silica nanoparticles (MSNs) with sizes of 60, 150 or 300 nm after intravenous administration to rats of mild AP (MAP) or severe AP (SAP). Four hours after administration, MSN150 was present to a much greater extent in the pancreas than MSN60 or MSN300, irrespective of disease severity. MSN150 was present to a lower extent in pancreas, intestine and ascites in SAP than MAP rats, indicating weaker passive targeting in SAP rats. This may reflect greater blood loss and slower blood flow in SAP. These findings may guide the rational engineering of NPs with respect to particle size and disease severity for AP therapy.

General Tolerance of Galactosyltransferases toward UDP-galactosamine Expands Their Synthetic Capability.

Accessing large numbers of structurally diverse glycans and derivatives is essential to functional glycomics. We showed a general tolerance of galactosyltransferases toward uridine-diphosphate-galactosamine (UDP-GalN), which is not a commonly used sugar nucleotide donor. The property was harnessed to develop a two-step chemoenzymatic strategy for facile synthesis of novel and divergent N-acetylgalactosamine (GalNAc)-glycosides and derivatives in preparative scales. The discovery and the application of the new property of existing glycosyltransferases expand their catalytic capabilities in generating novel carbohydrate linkages, thus prompting the synthesis of diverse glycans and glycoconjugates for biological studies.

Discharge-Induced Enhancement of the Oxygen Evolution Reaction.

The fundamental understanding of the surface reconstruction induced by the applied potential is of great significance for enhancing the oxygen evolution reaction (OER). Here, we show that a previously overlooked discharge current in the low applied potential region also leads to in situ electrochemical activation of a nitrogen-doped nickel oxyhydroxide surface. We exploit the fact that doping of heteroatoms weakens the surface structure, and hence, a weak discharge current originating from the capacitive nature of nickel oxyhydroxide has a strong structure-reforming ability to promote the formation of nitrogen and oxygen vacancies. The current density at 1.4 V (vs. Hg/HgO) can dramatically increase by as much as 31.3 % after discharge in the low applied potential region. This work provides insight into in situ enhancement of the OER and suggests that the low applied potential region must be a primary consideration in evaluating the origin of the activity of electrocatalysts.