Genome Mining of Pseudomonas Species: Diversity and Evolution of Metabolic and Biosynthetic Potential

Microbial genome sequencing has uncovered a myriad of natural products (NPs) that have yet to be explored. Bacteria in the genus Pseudomonas serve as pathogens, plant growth promoters, and therapeutically, industrially, and environmentally important microorganisms. Though most species of Pseudomonas have a large number of NP biosynthetic gene clusters (BGCs) in their genomes, it is difficult to link many of these BGCs with products under current laboratory conditions. In order to gain new insights into the diversity, distribution, and evolution of these BGCs in Pseudomonas for the discovery of unexplored NPs, we applied several bioinformatic programming approaches to characterize BGCs from Pseudomonas reference genome sequences available in public databases along with phylogenetic and genomic comparison. Our research revealed that most BGCs in the genomes of Pseudomonas species have a high diversity for NPs at the species and subspecies levels and built the correlation of species with BGC taxonomic ranges. These data will pave the way for the algorithmic detection of species- and subspecies-specific pathways for NP development.     

Boosting the Energy Density of Flexible Asymmetric Supercapacitor with Three Dimensional Fe2O3 Composite Brush Anode

Flexible asymmetric supercapacitor is fabricated with three dimensional(3D)Fe2O3/Ni(OH)2 composite brush anode and Ni(OH)2/MoO2 honeycomb cathode.Particularly for 3D composite brush anode,a layer of thin Fe2O3 film is firmly adhered on a 3D Ni brush current collector with the assist of Ni(OH)2,functioning as both adherence layer and pseudocapacitive active material.The unique 3D Ni brush current collector possesses large surface area and stretching architecture,which facilitate to achieve the composite anode with high gravimetric capacitance of 2158 F/g.In terms of cathode,Ni(OH)2 and MoO2 have a synergistic effect to improve the specific capacitance,and the resulting Ni(OH)2/MoO2 honeycomb cathode shows a very high gravimetric capacitance up to 3264 F/g.The asymmetric supercapacitor(ASC)has balanced cathode and anode,and exhibits an ultrahigh gravimetric capacitance of 1427 F/g and an energy density of 476 W·h/kg.The energy density of ASC is 3-4 times higher than those of other reported aqueous electrolyte-based supercapacitors and even comparable to that of commercial lithium ion batteries.The device also shows marginal capacitance degradation after 1000 cycles'bending test,demonstrating its potency in the application of flexible energy storage devices.     

Time-Dependent Photodynamic Therapy for Multiple Targets: A Highly Efficient AIE-Active Photosensitizer for Selective Bacterial Elimination and Cancer Cell Ablation

Pathogen infections and cancer are two major human health problems. Herein, we report the synthesis of an organic salt photosensitizer (PS), called 4TPA-BQ, by a one-step reaction. 4TPA-BQ presents aggregation-induced emission features. Owing to the aggregation-induced reactive oxygen species generated and a sufficiently small ΔE_ST, 4TPA-BQ shows a satisfactorily high ¹O₂ generation efficiency of 97.8 %. In vitro and in vivo experiments confirmed that 4TPA-BQ exhibited potent photodynamic antibacterial performance against ampicillin-resistant Escherichia coli with good biocompatibility in a short time (15 minutes). When the incubation duration persisted long enough (12 hours), cancer cells were ablated efficiently, leaving normal cells essentially unaffected. This is the first reported time-dependent fluorescence-guided photodynamic therapy in one individual PS, which achieves ordered and multiple targeting simply by varying the external conditions. 4TPA-BQ reveals new design principles for the implementation of efficient PSs in clinical applications.     

Unusual light-driven amplification through unexpected regioselective photogeneration of five-membered azaheterocyclic AIEgen

Developing versatile synthetic methodologies with merits of simplicity, efficiency, and environment friendliness for five-membered heterocycles is of incredible importance to pharmaceutical and material science, as well as a huge challenge to synthetic chemistry. Herein, an unexpected regioselective photoreaction to construct a fused five-membered azaheterocycle with an aggregation-induced emission (AIE) characteristic is developed under mild conditions. The formation of the five-membered ring is both thermodynamically and kinetically favored, as justified by theoretical calculation and experimental evidence. Markedly, a light-driven amplification strategy is proposed and applied in selective mitochondria-targeted cancer cell recognition and fluorescent photopattern fabrication with improved resolution. The work not only delivers the first report on efficiently generating a fused five-membered azaheterocyclic AIE luminogen under mild conditions via photoreaction, but also offers deep insight into the essence of the photosynthesis of fused five-membered azaheterocyclic compounds.

A multifunctional, AIE-based, fused five-membered azaheterocycle is photogenerated with light-driven amplification to combat the photobleaching issue and fabricate display materials.     

Synthesis and degradation of nontoxic biodegradable waterborne polyurethanes elastomer with poly(ε-caprolactone) and poly(ethylene glycol) as soft segment

In this study, in order to obtain waterborne polyurethanes (WBPUs) with biocompatibility, biodegradability as well as good mechanical properties, a series of nontoxic cross-linked waterborne polyurethanes were designed and synthesized with isophorone diisocyanate (IPDI), poly(ε-caprolactone) (PCL), poly(ethylene glycol) (PEG), 1,4-butandiol (BDO) and l-lysine without any other organic agent involved in the whole synthetic process. The bulk structures and properties were characterized by DSC, IR and Instron, mainly focused on the effect of amount of PEG. Their corresponding biodegradability was examined with Lipase AK. The result showed that the prepared waterborne polyurethanes had very good tensile properties, allowing them to be well used as biomaterials. And the change of tensile properties with increasing of amount of PEG in the polymers could be assigned to the change of microphase separation, as indicated by DSC and IR data. A quite good biodegradability was achieved as judged from the change of tensile properties as a function of time. The current work demonstrated a new synthetic approach that can be more promising to prepare both nontoxic and biodegradable polyurethanes for soft tissue engineering applications or drug delivery.     

NH_3－PDS法焦炉气脱硫脱氰的模拟研究

本文介绍了以焦炉气中自有的ＮＨ＿３为碱源，在ＰＤＳ（双核酞菁钴磺酸盐）的催化作用下，脱除煤气中Ｈ＿２Ｓ、ＨＣＮ的工艺模拟研究，提出了新的焦炉气净化工艺流程，称为Ａ－ＰＤＳ工艺。选择出了适宜的工艺条件，可将煤气中Ｈ＿２Ｓ由５～７ｇ／ｍ￣３脱至２０ｍｇ／ｍ￣３以下，脱除率达９９％以上；可将ＨＣＮ由０．８～１．３ｇ／ｍ￣３脱至２０ｍｇ／ｍ￣３以下，脱除率达９８％。     

碱性条件下4(3H)-喹唑啉酮的一锅合成

研究了一种碱性条件下由邻氨基芳香腈1与醛2一锅合成4(3H)-喹唑啉酮3的新方法.反应经由亲核加成、分子内的Pinner关环、Dimroth重排和氧化脱氢串联转化而成.产物结构经1H NMR,13C NMR,IR和元素分析确证.     

Detection of Large Ions in Time-of-Flight Mass Spectrometry: Effects of Ion Mass and Acceleration Voltage on Microchannel Plate Detector Response

In time-of-flight mass spectrometry (TOF-MS), ion detection is typically accomplished by the generation and amplification of secondary electrons produced by ions colliding with a microchannel plate (MCP) detector. Here, the response of an MCP detector as a function of ion mass and acceleration voltage is characterized, for singly charged peptide/protein ions ranging from 1 to 290 kDa in mass, and for acceleration voltages from 5 to 25 kV. A nondestructive inductive charge detector (ICD) employed in parallel with MCP detection provides a reliable reference signal to allow accurate calibration of the MCP response. MCP detection efficiencies were very close to unity for smaller ions at high acceleration voltages (e.g., angiotensin, 1046.5 Da, at 25 kV acceleration voltage), but decreased to ~11% for the largest ions examined (immunoglobulin G (IgG) dimer, 290 kDa) even at the highest acceleration voltage employed (25 kV). The secondary electron yield γ (average number of electrons produced per ion collision) is found to be proportional to mv^3.1 (m: ion mass, v: ion velocity) over the entire mass range examined, and inversely proportional to the square root of m in TOF-MS analysis. The results indicate that although MCP detectors indeed offer superlative performance in the detection of smaller peptide/protein species, their performance does fall off substantially for larger proteins, particularly under conditions of low acceleration voltage.

Time‐Dependent Photodynamic Therapy for Multiple Targets: A Highly Efficient AIE‐Active Photosensitizer for Selective Bacterial Elimination and Cancer Cell Ablation

Pathogen infections and cancer are two major human health problems. Herein, we report the synthesis of an organic salt photosensitizer (PS), called 4TPA‐BQ, by a one‐step reaction. 4TPA‐BQ presents aggregation‐induced emission features. Owing to the aggregation‐induced reactive oxygen species generated and a sufficiently small ΔE_ST, 4TPA‐BQ shows a satisfactorily high ¹O₂ generation efficiency of 97.8 %. In vitro and in vivo experiments confirmed that 4TPA‐BQ exhibited potent photodynamic antibacterial performance against ampicillin‐resistant Escherichia coli with good biocompatibility in a short time (15 minutes). When the incubation duration persisted long enough (12 hours), cancer cells were ablated efficiently, leaving normal cells essentially unaffected. This is the first reported time‐dependent fluorescence‐guided photodynamic therapy in one individual PS, which achieves ordered and multiple targeting simply by varying the external conditions. 4TPA‐BQ reveals new design principles for the implementation of efficient PSs in clinical applications.     

Visible light-driven flower-like Bi/BiOClxBr(1−x) heterojunction with excellent photocatalytic performance

In this work, a series of flower-like Bi/BiOCl_xBr_(1−x) heterojunction photocatalysts have been developed. Bi nanoparticles were grown on the BiOCl_xBr_(1−x) nanosheets via an in situ chemical reduction with the assistance of cetyltrimethylammonium chloride and cetyltrimethylammonium bromide aqueous solution. The in situ growth of Bi nanoparticles on the BiOCl_xBr_(1−x) nanosheets could not only give rise to the optical absorption in the visible region, but also promote the photocatalytic performance of BiOCl_xBr_(1−x). Bi/BiOCl_0.8Br_0.2 exhibited the highest photocatalytic performance, which could completely degrade RhB in 12 min under the UV light irradiation and 6 min under visible light irradiation, respectively. Moreover, holes and superoxide radicals were verified to be the primarily active species in the photocatalytic process.