Au₃₈S₂(SAdm)₂₀ Photocatalyst for One-Step Selective Aerobic Oxidations

We here report a protocol for the synthesis of Au₃₈S₂(SAdm)₂₀ nanoclusters (−SAdm = 1-adamantanethiolate) with a higher production yield (10%) in comparison to previous reported methods. The photosensitizing properties of the gold nanoclusters are investigated for the formations of singlet oxygen (¹O₂) using visible light wavelengths of 532 and 650 nm. The formation of ¹O₂ was detected by 1,3-diphenylisobenzofuran as the chemical trapping probe as well as direct observation of the characteristic ¹O₂ emission (ca. 1276 nm). The efficiency of the ¹O₂ formation using the Au₃₈S₂(SAdm)₂₀ nanoclusters is found to be notably higher than that of Au₂₅(SR)₁₈ nanoclusters. Finally, selective aerobic oxidations of sulfide to sulfoxide and benzylamine to imine in the presence of oxygen (³O₂) and photoexcited Au₃₈S₂(SAdm)₂₀ are well studied. This work demonstrates the promise of Au₃₈S₂(SAdm)₂₀ nanoclusters in the generation of activated singlet oxygen for selective catalytic reactions

MOESM1 of Efficient 3-hydroxypropionic acid production from glycerol by metabolically engineered Klebsiella pneumoniae

Additional file 1: Figure S1. λ-Red-mediated recombinase assisted gene replacement for dhaT knockout in Klebsiella pneumoniae. Figure S2. A. Confirmation of ldhA deletion in Kp4 by single colony PCR. M, DL2000 Marker; 1, wild-type Kp4 at 2221bp; 2-5, Kp4 ΔldhA::apr at 2773bp. B. Confirmation of dhaT deletion in JJQ01 by single colony PCR. M, DL2000 Marker; 1, wild-type Kp4 at 2642bp; 2-4, Kp4ΔldhAΔdhaT::apr at 2847bp

Video_1_Endoscopic endonasal resection of an epidermoid cyst in the cavernous sinus: A case report and literature review.mp4

BackgroundEpidermoid cysts of cavernous sinus (CS) are rare congenital neoplasms of the central nervous system. In previous literature reports, the treatment for CS epidermoid cysts was mainly microsurgical resection, and the surgical methods included simple microsurgery and endoscope-assisted microsurgery. The present case report demonstrates the first case of complete resection of a CS epidermoid cyst by a simple endoscopic endonasal transcavernous (EET) approach.Case presentationA 54-year-old woman presented with chronic persistent headaches and occasional syncope. Brain MRI demonstrated a space-occupying lesion of the left CS, and digital substruction angiography (DSA) showed a small aneurysm at the beginning of the left ophthalmic artery. Thrombotic therapy of carotid–ophthalmic aneurysms was performed first, and the patient underwent resection of the CS lesion secondary. Considering the location of the lesion and the neuroendoscopy technology and experience of the doctor, we made bold innovations and used an EET approach to achieve complete resection of the lesion. The postoperative pathological results were consistent with the characteristics of epidermoid cyst. During the 1-year follow up, the patient showed no apparent signs of recurrence on head MRI.ConclusionEpidermoid cyst of cavernous sinus is a rare benign occupying lesion in cavernous sinus. Reviewing the previous literature, the main treatment is microneurosurgery, and neuroendoscopy is only used as an auxiliary equipment. We present the first case of complete endoscopic resection of CS epidermoid cyst by EET approach according to CARE guidelines, aiming to share the new surgical plan for CS epidermoid cyst and provide more surgical options for this disease for neurosurgery colleagues.</p

Production of Succinate from Acetate by Metabolically Engineered <i>Escherichia coli</i>

Acetate, a major component of industrial biological wastewater and of lignocellulosic biomass hydrolysate, could potentially be a less costly alternative carbon source. Here we engineered <i>Escherichia coli</i> MG1655 strain for succinate production from acetate as the sole carbon source. Strategies of metabolic engineering included the blockage of the TCA cycle, redirection of the gluconeogenesis pathway, and enhancement of the glyoxylate shunt. The engineered strain MG03 featuring the deletion of genes: succinate dehydrogenase (<i>sdhAB</i>), isocitrate lyase regulator (<i>iclR</i>), and malic enzymes (<i>maeB</i>) accumulated 6.86 mM of succinate in 72 h. MG03­(pTrc99a-<i>gltA</i>) overexpressing citrate synthase (<i>gltA</i>) accumulated 16.45 mM of succinate and the yield reached 0.46 mol/mol, about 92% of the maximum theoretical yield. Resting-cell was adopted for the conversion of acetate to succinate, and the highest concentration of succinate achieved 61.7 mM

Determining the Absolute Concentration of Nanoparticles without Calibration Factor by Visualizing the Dynamic Processes of Interfacial Adsorption

Previous approaches of determining the molar concentration of nanoparticles often relied on the calibration factors extracted from standard samples or required prior knowledge regarding the geometry, optical, or chemical properties. In the present work, we proposed an absolute quantification method that determined the molar concentration of nano-objects without any calibration factor or prior knowledge. It was realized by monitoring the dynamic adsorption processes of individual nanoparticles with a high-speed surface plasmon resonance microscopy. In this case, diffusing nano-objects stochastically collided onto an adsorption interface and stayed there (“hit-n-stay” scenario), resulting in a semi-infinite diffusion system. The dynamic processes were analyzed with a theoretical model consisting of Fick’s laws of diffusion and random-walk assumption. The quantification of molar concentration was achieved on the basis of an analytical expression, which involved only physical constants and experimental parameters. By using spherical polystyrene nanoparticles as a model, the present approach provided a molar concentration with excellent accuracy

Temporal Resolution of Autophosphorylation for Normal and Oncogenic Forms of EGFR and Differential Effects of Gefitinib

Epidermal growth factor receptor (EGFR) is a member of the ErbB family of receptor tyrosine kinases (RTK). EGFR overexpression or mutation in many different forms of cancers has highlighted its role as an important therapeutic target. Gefitinib, the first small molecule inhibitor of EGFR kinase function to be approved for the treatment of nonsmall cell lung cancer (NSCLC) by the FDA, demonstrates clinical activity primarily in patients with tumors that harbor somatic kinase domain mutations in EGFR. Here, we compare wild-type EGFR autophosphorylation kinetics to the L834R (also called L858R) EGFR form, one of the most common mutations in lung cancer patients. Using rapid chemical quench, time-resolved electrospray mass spectrometry (ESI-MS), and Western blot analyses, we examined the order of autophosphorylation in wild-type (WT) and L834R EGFR and the effect of gefitinib (Iressa) on the phosphorylation of individual tyrosines. These studies establish that there is a temporal order of autophosphorylation of key tyrosines involved in downstream signaling for WT EGFR and a loss of order for the oncogenic L834R mutant. These studies also reveal unique signature patterns of drug sensitivity for inhibition of tyrosine autophosphorylation by gefitinib: distinct for WT and oncogenic L834R mutant forms of EGFR. Fluorescence studies show that for WT EGFR the binding affinity for gefitinib is weaker for the phosphorylated protein while for the oncogenic mutant, L834R EGFR, the binding affinity of gefitinib is substantially enhanced and likely contributes to the efficacy observed clinically. This mechanistic information is important in understanding the molecular details underpinning clinical observations as well as to aid in the design of more potent and selective EGFR inhibitors

Image_1_Effect of maltodextrin on the oxidative stability of ultrasonically induced soybean oil bodies microcapsules.PNG

IntroductionEncapsulation of soybean oil bodies (OBs) using maltodextrin (MD) can improve their stability in different environmental stresses and enhance the transport and storage performance of OBs.MethodsIn this study, the effects of different MD addition ratios [OBs: MD = 1:0, 1:0.5, 1:1, 1:1.5, and 1:2 (v/v)] on the physicochemical properties and oxidative stability of freeze-dried soybean OBs microcapsules were investigated. The effect of ultrasonic power (150–250 W) on the encapsulation effect and structural properties of oil body-maltodextrin (OB-MD) microcapsules were studied.ResultsThe addition of MD to OBs decreased the surface oil content and improved the encapsulation efficiency and oxidative stability of OBs. Scanning electron microscopy images revealed that the sonication promoted the adsorption of MD on the surface of OBs, forming a rugged spherical structure. The oil-body-maltodextrin (OB-MD) microcapsules showed a narrower particle size distribution and a lower-potential absolute value at an MD addition ratio of 1:1.5 and ultrasonic power of 250 W (32.1 mV). At this time, MD-encapsulated OBs particles had the highest encapsulation efficiency of 85.3%. Ultrasonic treatment improved encapsulation efficiency of OBs and increased wettability and emulsifying properties of MD. The encapsulation of OBs by MD was improved, and its oxidative stability was enhanced by ultrasound treatment, showing a lower hydrogen peroxide value (3.35 meq peroxide/kg) and thiobarbituric acid value (1.65 μmol/kg).DiscussionThis study showed that the encapsulation of soybean OBs by MD improved the stability of OBs microcapsules and decreased the degree of lipid oxidation during storage. Ultrasonic pretreatment further improved the encapsulation efficiency of MD on soybean OBs, and significantly enhanced its physicochemical properties and oxidative stability.</p

DataSheet_1_An allergenic plant calmodulin from Artemisia pollen primes human DCs leads to Th2 polarization.doc

Artemisia pollen is the major cause of seasonal allergic respiratory diseases in the northern hemisphere. About 28.57% of Artemisia allergic patients’ IgE can recognize ArtCaM, a novel allergenic calmodulin from Artemisia identified in this study. These patients exhibited stronger allergic reactions and a longer duration of allergic symptoms. However, the signaling mechanism that triggers these allergic reactions is not fully understood. In this study, we found that extracellular ArtCaM directly induces the maturation of human dendritic cells (DCs), which is attributed to a series of Ca2+ relevant cascades, including Ca2+/NFAT/CaMKs. ArtCaM alone induces inflammatory response toward Th1, Th17, and Treg. Interestingly, a combination of ArtCaM and anti-ArtCaM IgE led to Th2 polarization. The putative mechanism is that anti-ArtCaM IgE partially blocks the ArtCaM-induced ERK signal, but does not affect Ca2+-dependent cascades. The crosstalk between ERK and Ca2+ signal primes DCs maturation and Th2 polarization. In summary, ArtCaM related to clinical symptoms when combined with anti-ArtCaM IgE, could be a novel allergen to activate DCs and promote Th2 polarization. Such findings provide mechanistic insights into Th2 polarization in allergic sensitization and pave the way for novel preventive and therapeutic strategies for efficient management of such pollen allergic disease.</p

Tailoring the Electronic and Catalytic Properties of Au₂₅ Nanoclusters <i>via</i> Ligand Engineering

To explore the electronic and catalytic properties of nanoclusters, here we report an aromatic-thiolate-protected gold nanocluster, [Au₂₅(SNap)₁₈]⁻ [TOA]⁺, where SNap = 1-naphthalenethiolate and TOA = tetraoctylammonium. It exhibits distinct differences in electronic and catalytic properties in comparison with the previously reported [Au₂₅(SCH₂CH₂Ph)₁₈]⁻, albeit their skeletons (<i>i.e.</i>, Au₂₅S₁₈ framework) are similar. A red shift by ∼10 nm in the HOMO–LUMO electronic absorption peak wavelength is observed for the aromatic-thiolate-protected nanocluster, which is attributed to its dilated Au₁₃ kernel. The unsupported [Au₂₅(SNap)₁₈]⁻ nanoclusters show high thermal and antioxidation stabilities (<i><i>e.g.</i></i>, at 80 °C in the present of O₂, excess H₂O₂, or TBHP) due to the effects of aromatic ligands on stabilization of the nanocluster’s frontier orbitals (HOMO and LUMO). Furthermore, the catalytic activity of the supported Au₂₅(SR)₁₈/CeO₂ (R = Nap, Ph, CH₂CH₂Ph, and <i>n</i>-C₆H₁₃) is examined in the Ullmann heterocoupling reaction between 4-methyl-iodobenzene and 4-nitro-iodobenzene. Results show that the activity and selectivity of the catalysts are largely influenced by the chemical nature of the protecting thiolate ligands. This study highlights that the aromatic ligands not only lead to a higher conversion in catalytic reaction but also markedly increase the yield of the heterocoupling product (4-methyl-4′-nitro-1,1′-biphenyl). Through a combined approach of experiment and theory, this study sheds light on the structure–activity relationships of the Au₂₅ nanoclusters and also offers guidelines for tailoring nanocluster properties by ligand engineering for specific applications

Table_1_An allergenic plant calmodulin from Artemisia pollen primes human DCs leads to Th2 polarization.xlsx

Artemisia pollen is the major cause of seasonal allergic respiratory diseases in the northern hemisphere. About 28.57% of Artemisia allergic patients’ IgE can recognize ArtCaM, a novel allergenic calmodulin from Artemisia identified in this study. These patients exhibited stronger allergic reactions and a longer duration of allergic symptoms. However, the signaling mechanism that triggers these allergic reactions is not fully understood. In this study, we found that extracellular ArtCaM directly induces the maturation of human dendritic cells (DCs), which is attributed to a series of Ca2+ relevant cascades, including Ca2+/NFAT/CaMKs. ArtCaM alone induces inflammatory response toward Th1, Th17, and Treg. Interestingly, a combination of ArtCaM and anti-ArtCaM IgE led to Th2 polarization. The putative mechanism is that anti-ArtCaM IgE partially blocks the ArtCaM-induced ERK signal, but does not affect Ca2+-dependent cascades. The crosstalk between ERK and Ca2+ signal primes DCs maturation and Th2 polarization. In summary, ArtCaM related to clinical symptoms when combined with anti-ArtCaM IgE, could be a novel allergen to activate DCs and promote Th2 polarization. Such findings provide mechanistic insights into Th2 polarization in allergic sensitization and pave the way for novel preventive and therapeutic strategies for efficient management of such pollen allergic disease.</p