Fabrication of a Near-Infrared-Emissive Probe for Detecting Dipeptidyl Peptidase 4 in the Liver of Diabetic Mice and Clinical Serum.

Dipeptidyl peptidase 4 (DPP4) plays a key role in glucose metabolism, which has been a close target for diabetes pathology and treatment. It is significant for the evaluation of cellular DPP4 activity in various biological systems. Fluorescence imaging technology is currently a popular method for detecting enzymes in living cells due to its advantages of high selectivity, high sensitivity, high spatiotemporal resolution, and real-time visualization. Herein, a near-infrared (NIR)-emissive probe NEDP with a large Stokes shift (153 nm) was developed for the assay of DPP4 activity. Upon addition of DPP4, NEDP can emit a significant turn-on NIR fluorescence signal (673 nm) with high sensitivity and specificity. Moreover, NEDP can successfully be used for imaging of intracellular DPP4, confirming the regulation of DPP4 expression in hyperglucose and its treatment in living cells. Most importantly, NEDP can not only monitor the changes of DPP4 in vivo but also show that DPP4 in diabetes is mainly up-regulated in the liver, and the level of DPP4 is positively correlated with the pathological damage of the liver. In addition, NEDP can identify the serum of diabetic patients from healthy people through the fluorescence response to DPP4. These results demonstrated that the designed probe NEDP provides a prospective visual tool to explore the relationship between DPP4 and diabetes and would be applied for detecting serum of diabetes in the clinic.

Construction of an Ohmic Contact Cathode by Two Metal Sulfides for efficient Capture and Catalysis of Polysulfide.

The slow reaction kinetics and severe shuttle effect of lithium polysulfide make Li-S battery electrochemical performance difficult to meet the demands of large electronic devices such as electric vehicles. Based on this, an electrocatalyst constructed by metal phase material (MoS2) and semiconductor phase material (SnS2) with ohmic contact is designed for inhibiting the dissolution of lithium polysulfide with improving the reaction kinetics. According to the density-functional theory calculations, it is found that the heterostructured samples with ohmic contacts can effectively reduce the reaction-free energy of lithium polysulfide to accelerate the sulfur redox reaction, in addition to the excellent electron conduction to reduce the overall activation energy. The metallic sulfide can add more sulfophilic sites to promote the capture of polysulfide. Thanks to the ohmic contact design, the carbon nanotube-MoS2-SnS2 achieved a specific capacity of 1437.2 mAh g-1 at 0.1 C current density and 805.5 mAh g-1 after 500 cycles at 1 C current density and is also tested as a pouch cell, which proves to be valuable for practical applications. This work provides a new idea for designing an advanced and efficient polysulfide catalyst based on ohmic contact.

Regulate the Solvation Structure and Interface by Nitrate in Phosphate-Based Electrolytes for 4.5 V-Class Ni-Rich Batteries.

Phosphate-based electrolyte propels the advanced battery system with high safety. Unfortunately, restricted by poor electrochemical stability, it is difficult to be compatible with advanced lithium metal anodes and Ni-rich cathodes. To alleviate these issues, the study has developed a phosphate-based localized high-concentration electrolyte with a nitrate-driven solvation structure, and the nitrate-derived N-rich inorganic interface shows excellent performance in stabilizing the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode interface and modulating the lithium deposition morphology on the anode. The results show that the Li|| NCM811 cell has exceptional long-cycle stability of >80% capacity retention after 800 cycles at 4.3 V, 1 C. A more prominent capacity retention rate of 93.3% after 200 cycles can be reached with the high voltage of 4.5 V. While being compatible with the phosphate-based electrolyte with good flame retardancy and the good electrochemical stability of Ni-rich lithium metal battery (LMBs) systems, the present work expands the construction of anion-rich solvation structures, which is expected to promote the development of the high-performance LMBs with safety.

Localized High-Concentration Sulfone Electrolytes with High-Voltage Stability and Flame Retardancy for Ni-Rich Lithium Metal Batteries.

The localized high-concentration electrolyte (LHCE) propels the advanced high-voltage battery system. Sulfone-based LHCE is a transformative direction compatible with high energy density and high safety. In this work, the application of lithium bis(trifluoromethanesulphonyl)imide and lithium bis(fluorosulfonyl)imide (LiFSI) in the LHCE system constructed from sulfolane and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) is investigated. The addition of diluent causes an increase of contact ion pairs and ionic aggregates in the solvation cluster and an acceptable quantity of free solvent molecules. A small amount of LiFSI as an additive can synergistically decompose with TTE on the cathode and participate in the construction of both electrode interfaces. The designed electrolyte helps the Ni-rich system to cycle firmly at a high voltage of 4.5 V. Even with high mass load and lean electrolyte, it can keep a reversible specific capacity of 91.5% after 50 cycles. The constructed sulfone-based electrolyte system exhibits excellent thermal stability far beyond the commercial electrolytes. Further exploration of in-situ gelation has led to a quick conversion of the designed liquid electrolyte to the gel state, accompanied by preserved stability, which provides a direction for the synergistic development of LHCE with gel electrolytes.

PD-1 inhibitor plus concurrent chemoradiotherapy for high-risk locally advanced cervical cancer.

Aim: The prognosis of high-risk, locally advanced cervical cancer (LACC) remains poor following concurrent chemoradiotherapy (CCRT). We investigated whether the effect of CCRT can be enhanced by programmed cell death protein 1 (PD-1) inhibitor. Methods: A retrospective cohort study was conducted to compare the efficacy and safety of CCRT group (n = 82) and PD-1 inhibitor plus CCRT group (n = 70). Results: Compared with the CCRT group, the PD-1 inhibitor plus CCRT group had significantly higher objective response rate, median progression-free survival, leukopenia and fatigue. The addition of PD-1 inhibitor to CCRT showed a favorable trend in overall survival without statistical significance. Conclusion: PD-1 inhibitor plus CCRT presented a significant survival benefit and a manageable safety profile in high-risk LACC.

[Box: see text].

Study on the preservation effects of the amputated forelimb by machine perfusion at physiological temperature.

PURPOSE: Ischemia and hypoxia are the main factors limiting limb replantation and transplantation. Static cold storage (SCS), a common preservation method for tissues and organs, can only prolong limb ischemia time to 4 - 6 h. The normothermic machine perfusion (NMP) is a promising method for the preservation of tissues and organs, which can extend the preservation time in vitro by providing continuous oxygen and nutrients. This study aimed to evaluate the difference in the efficacy of the 2 limb preservation methods. METHODS: The 6 forelimbs from beagle dogs were divided into 2 groups. In the SCS group (n = 3), the limbs were preserved in a sterile refrigerator at 4 °C for 24 h, and in the NMP group (n = 3), the perfusate prepared with autologous blood was used for the oxygenated machine perfusion at physiological temperature for 24 h, and the solution was changed every 6 h. The effects of limb storage were evaluated by weight gain, perfusate biochemical analysis, enzyme-linked immunosorbent assay, and histological analysis. All statistical analyses and graphs were performed using GraphPad Prism 9.0 one-way or two-way analysis of variance. The p value of less than 0.05 was considered to indicate statistical significance. RESULTS: In the NMP group, the weight gained percentage was 11.72% ± 4.06%; the hypoxia-inducible factor-1α contents showed no significant changes; the shape of muscle fibers was normal; the gap between muscle fibers slightly increased, showing the intercellular distance of (30.19 ± 2.83) µm; and the vascular α-smooth muscle actin (α-SMA) contents were lower than those in the normal blood vessels. The creatine kinase level in the perfusate of the NMP group increased from the beginning of perfusion, decreased after each perfusate change, and remained stable at the end of perfusion showing a peak level of 4097.6 U/L. The lactate dehydrogenase level of the NMP group increased near the end of perfusion and reached the peak level of 374.4 U/L. In the SCS group, the percentage of weight gain was 0.18% ± 0.10%, and the contents of hypoxia-inducible factor-1α increased gradually and reached the maximum level of (164.85 ± 20.75) pg/mL at the end of the experiment. The muscle fibers lost their normal shape and the gap between muscle fibers increased, showing an intercellular distance of (41.66 ± 5.38) µm. The contents of vascular α-SMA were much lower in the SCS group as compared to normal blood vessels. CONCLUSIONS: NMP caused lesser muscle damage and contained more vascular α-SMA as compared to SCS. This study demonstrated that NMP of the amputated limb with perfusate solution based on autologous blood could maintain the physiological activities of the limb for at least 24 h.

Effect of mutation at c.493T>C locus of transcription factor HNF1α gene on its protein level.

Hepatocyte nuclear factor 1α (HNF1α) is a transcription factor that is crucial for the regulation to maintain the function of pancreatic ß-cell, hepatic lipid metabolism, and other processes. Mature-onset diabetes of the young type 3 is a monogenic form of diabetes caused by HNF1α mutations. Although several mutation sites have been reported, the specific mechanisms remain unclear, such hot-spot mutation as the P291fsinsC mutation and the P112L mutation and so on. In preliminary studies, we discovered one MODY3 patient carrying a mutation at the c.493T>C locus of the HNF1α gene. In this study, we analyzed the pathogenic of the mutation sites by using the Mutation Surveyor software and constructed the eukaryotic expression plasmids of the wild-type and mutant type of HNF1α to detect variations in the expression levels and stability of HNF1α protein by using Western blot. The analyses of the Mutation Surveyor software showed that the c.493T>C site mutation may be pathogenic gene and the results of Western blot showed that both the amount and stability of HNF1α protein expressed by the mutation type plasmid were reduced significantly compared to those by the wild type plasmid (P<0.05). This study suggests that the c.493T>C (p.Trp165Arg) mutation dramatically impacts HNF1α expression, which might be responsible for the development of the disease and offers fresh perspectives for the following in-depth exploration of MODY3's molecular pathogenic process.

Functional insights of three RING-finger peroxins in the life cycle of the insect pathogenic fungus Beauveria bassiana.

Peroxisomes play important roles in fungal physiological processes. The RING-finger complex consists of peroxins Pex2, Pex10, and Pex12 and is essential for recycling of receptors responsible for peroxisomal targeting of matrix proteins. In this study, these three peroxins were functionally characterized in the entomopathogenic fungus Beauveria bassiana (Bb). These three peroxins are associated with peroxisomes, in which BbPex2 interacted with BbPex10 and BbPex12. Ablation of these peroxins did not completely block the peroxisome biogenesis, but abolish peroxisomal targeting of matrix proteins via both PTS1 and PTS2 pathways. Three disruptants displayed different phenotypic defects in growth on nutrients and under stress conditions, but have similar defects in acetyl-CoA biosynthesis, development, and virulence. Strikingly, BbPex10 played a less important role in fungal growth on tested nutrients than other two peroxins; whereas, BbPex2 performed a less important contribution to fungal growth under stresses. This investigation reinforces the peroxisomal roles in the lifecycle of entomopathogenic fungi and highlights the unequal functions of different peroxins in peroxisomal biology.

Limimaricola litoreus sp. nov., isolated from intertidal sand of the Yellow Sea.

A novel species of the genus Limimaricola, designated ASW11-118T, was isolated from an intertidal sand sample of the Yellow Sea, PR China. Growth of strain ASW11-118T occurred at 10-40 °C (optimum, 28 °C), pH 5.5-8.5 (optimum, pH 7.5) and with 0.5-8.0 % (w/v) NaCl (optimum, 1.5%). Strain ASW11-118T has the highest 16S rRNA gene sequence similarity to Limimaricola cinnabarinus LL-001T (98.8%) and 98.6 % to Limimaricola hongkongensis DSM 17492T. Phylogenetic analysis based on genomic sequences indicated that strain ASW11-118T belongs to the genus Limimaricola. The genome size of strain ASW11-118T was 3.8 Mb and DNA G+C content was 67.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain ASW11-118T and other members of the genus Limimaricola were below 86.6 and 31.3 %, respectively. The predominant respiratory quinone was ubiquinone-10. The predominant cellular fatty acid was C18 : 1 ω7c. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and one unknown aminolipid. On the basis of the data presented, strain ASW11-118T is considered to represent a novel species of the genus Limimaricola, for which the name Limimaricola litoreus sp. nov. is proposed. The type strain is ASW11-118T (=MCCC 1K05581T=KCTC 82494T).

First Report of Erysiphe astragali Causing Powdery Mildew on Astragalus mongholicus in China.

Astragalus mongholicus Bge. [A. membranaceus Bge. var. mongholicus (Bge.) Hsiao] is a highly valuable perennial medicinal plant mainly distributed in China, whose dry roots are known as Huangqi in traditional Chinese medicine for reinforcing vital energy, strengthening superficial resistance, and promoting tissue regeneration (Lin et al. 2000). A. mongholicus roots of high quality are produced in Northwest and North China. Since July 2021, powdery mildew outbreaks happened annually on the leaves of A. mongholicus in a plantation (123° 56' 40'' E, 47° 22' 20'' N) in Qiqihar city, Heilongjiang Province, China. Disease incidence reached 100% by October (Fig. 1A-C), causing severe impairment of growth. Powdery mildew spots of circular or irregular shapes emerged on upper surface of leaf, resulting in plentiful lesion specks. Dense white hyphae appeared chaotically intertwined. Hyphae were hyaline and highly flexuous, 5.3 - 10.7 µm in diameter (n = 20). Chasmothecia were globose or slightly ovoid-shaped and turned dark brown when matured. Chasmothecia (diameter: 135.2 - 222.9 µm, n = 20) existed abundantly on the diseased leaves in the fields. Conidiophores were 89.0 - 129.9 µm in length (n = 20) and composed of one cylindrical, straight foot cell, followed by two cells and one to three conidia. Conidia were slim ellipsoid-shaped, occasionally ovoid-shaped, measuring 14.6 - 24.7 µm by 6.4 to10.4 µm, length/width ratio was 1.8 - 3.0 (n = 30). Hyphal appressoria were nipple-shaped and appeared in singular, occasionally in pairs. Unbranched germ tube emerged reaching out of the germinating conidia while forming an acute angle with the long axis. Comprehensively, the pathogen exhibited micro-morphology of the genus Erysiphe. For molecular identification, pathogen was carefully scraped off diseased leaves for DNA extraction. We used the DNA samples of three biological replicates for the sequencing of the ITS rDNA fragment (primers by (White et al. 1990). All the samples resulted in an identical ITS sequence (deposited in GenBank as OQ390098.1). It displayed 99.83% identity with OP806835.1 of an E. astragali voucher collected in Iran (Fig. 1D-M, O). Hence, our pathogen was identified as an E. astragali stain. Additionally, we amplified the Mcm7 sequence (using primers by (Ellingham et al. 2019), deposited as OQ397582.1). We propagated 40-day-old A. mongholicus plants via germinating seeds in pot soil and performed pathogenicity tests. Firstly, we incubated detached healthy leaves of propagated plants with severely symptomatic leaves collected from the fields in petri dishes under saturated moisture content and room temperature. Powdery mildew symptoms emerged on each healthy leaf (n = 5) after two weeks. Further, we infected healthy plants (n = 5) by gently pressing and rubbing symptomatic leaves on each healthy leaf, and kept them in a greenhouse (24 ℃, 80% humidity, 16/8-hour light/dark cycle). After a month, symptoms emerged on a number of leaves of each infected plant. We performed micromorphology observation (Fig. 1N-P) and ITS sequencing to confirm that the results fulfilled Koch's postulates. Powdery mildew caused by E. astragali on A. strictus in Tibet (Wang and Jiang 2023) and on A. scaberrimus in Inner Mongolia (Sun et al. 2023) have been reported. Here we report powdery mildew caused by E. astragali on Astragalus mongholicus for the first time. These Astragalus spp. are all acknowledged to have medicinal values in China but their usages are quite different.

Systematic contributions of CFEM domain-containing proteins to iron acquisition are essential for interspecies interaction of the filamentous pathogenic fungus Beauveria bassiana.

Common in fungal extracellular membrane (CFEM) domain is unique in fungal proteins and some of which contribute to iron acquisition in yeast. However, their roles in iron acquisition remain largely unknown in filamentous fungi. In this study, 12 CFEM-containing proteins were bioinformatically identified in the filamentous entomopathogenic fungus Beauveria bassiana, and the roles of 11 genes were genetically characterized. Transmembrane helices were critical for their association with intracellular membranes, and their number varied among proteins. Eleven CFEM genes significantly contribute to vegetative growth under iron starvation and virulence. Notably, the virulence of most disruptants could be significantly weakened by a decrease in iron availability, in which the virulence of ΔBbcfem7 and 8 strains was partially recovered by exogenous hemin. ΔBbcfem7 and 8 mutants displayed defective competitiveness against the sister entomopathogenic fungus Beauveria brongniartii. All 11 disruptants displayed impaired growth in the antagonistic assay with the saprotrophic fungus Aspergillus niger, which could be repressed by exogenous ferric ions. These findings not only reveal the systematic contributions of CFEM proteins to acquire two forms of iron (i.e. heme and ferric ion) in the entire lifecycle of entomopathogenic fungi but also help to better understand the mechanisms of fungus-host and inter-fungus interactions.

The complete plastomes of seven Peucedanum plants: comparative and phylogenetic analyses for the Peucedanum genus.

BACKGROUND: The Peucedanum genus is the backbone member of Apiaceae, with many economically and medically important plants. Although the previous studies on Peucedanum provide us with a good research basis, there are still unclear phylogenetic relationships and many taxonomic problems in Peucedanum, and a robust phylogenetic framework of this genus still has not been obtained, which severely hampers the improvement and revision of taxonomic system for this genus. The plastid genomes possessing more variable characters have potential for reconstructing a robust phylogeny in plants. RESULTS: In the current study, we newly sequenced and assembled seven Peucedanum plastid genomes. Together with five previously published plastid genomes of Peucedanum, we performed a comprehensively comparative analyses for this genus. Twelve Peucedanum plastomes were similar in terms of genome structure, codon bias, RNA editing sites, and SSRs, but varied in genome size, gene content and arrangement, and border of SC/IR. Fifteen mutation hotspot regions were identified among plastid genomes that can serve as candidate DNA barcodes for species identification in Peucedanum. Our phylogenetic analyses based on plastid genomes generated a phylogeny with high supports and resolutions for Peucedanum that robustly supported the non-monophyly of genus Peucedanum. CONCLUSION: The plastid genomes of Peucedanum showed both conservation and diversity. The plastid genome data were efficient and powerful for improving the supports and resolutions of phylogeny for the complex Peucedanum genus. In summary, our study provides new sights into the plastid genome evolution, taxonomy, and phylogeny for Peucedanum species.

The phylogeny of Seseli (Apiaceae, Apioideae): insights from molecular and morphological data.

BACKGROUND: The genus Seseli L., which consists of 125-140 species distributed in the Old World from western Europe and northwestern Africa to China and Japan, is one of the largest and most taxonomically difficult genera of Apiaceae Lindl. Although several previous studies have been conducted on Seseli based on limited morphological characteristics and molecular fragments, a robust and comprehensive phylogeny of Seseli remains elusive. Plastomes provide abundant genetic information and have been widely used in studying plant phylogeny and evolution. Consequently, we newly generated the complete plastomes of eleven Seseli taxa. We combined plastome data and morphological characteristics to investigate the phylogeny of Seseli. RESULTS: In our study, we observed that the genome length, gene numbers, IR/SC borders, and repeat composition of the eleven Seseli plastomes were variable. Several appropriate mutation hotspot regions may be developed as candidate DNA barcodes for evolution, phylogeny, and species identification of Seseli. The phylogenetic results identified that Seseli was not a monophyletic group. Moreover, the eleven newly sequenced Seseli taxa did not cluster with S. tortuosum (the type species of Seseli, belonging to the tribe Selineae), where S. delavayi clustered with Eriocycla belonging to the tribe Echinophoreae and the other ten belonged to Selineae. The comparative plastome and morphological characteristics analyses confirmed the reliability of the phylogenetic analyses and implied the complex evolution of Seseli. CONCLUSION: Combining molecular and morphological data is efficient and useful for studying the phylogeny of Seseli. We suggest that "a narrow sense" of Seseli will be meaningful for further study and the current taxonomic system of Seseli needs to be revised. In summary, our study can provide new insights into the phylogenetic relationships and taxonomic framework of Seseli.

Functional characterization of two homologs of yeast acetyl-coenzyme A synthetase in the entomopathogenic fungus Beauveria bassiana.

Acetyl-coenzyme A (CoA) synthetase (Acs) links cellular metabolism and physiology by catalyzing acetate and CoA into acetyl-CoA. However, the biological roles of Acs are not well studied in entomopathogenic fungi. In this study, two Acs proteins (BbAcs1 and BbAcs2) was functionally characterized in the filamentous insect pathogenic fungus Beauveria bassiana. BbAcs1 and BbAcs2 localize in cytoplasm and peroxisome, respectively. BbAcs1 contributes to vegetative growth on fatty acids as carbon source, and BbAcs2 did not. Both genes did not contribute to fungal response to stresses. The BbAcs1 loss conferred a slight influence on conidiation, and did not result in the defects in blastospore formation. On the contrary, BbAcs2 significantly contributes to lipid metabolism in germlings, blastospore formation, and virulence. The results indicated that Acs2 played a more predominant role than Acs1 in B. bassiana, which links the acetyl-CoA metabolism with the lifestyle of entomopathogenic fungi.

Pneumocystis jirovecii-associated immune reconstitution inflammatory syndrome-like phenomenon in a child with leukaemia: a case report and literature review.

BACKGROUND: Immune reconstitution inflammatory syndrome (IRIS) refers to the phenomenon of intense immune responses against pathogens in patients with AIDS undergoing antiretroviral therapy to reconstitute immune function, resulting in functional impairment of multiple organs. Non-AIDS immunosuppressed hosts may also develop similar manifestations to IRIS during immune recovery. CASE PRESENTATION: An 8-year-old girl presented with acute lymphoblastic leukaemia was admitted for scheduled chemotherapy treatment. During chemotherapy, she experienced pancytopenia and Pneumocystis jirovecii pneumonia, which was diagnosed based on the abnormal shadows observed on chest computed tomography, the elevation of serum ß-D-glucan, and the positive mNGS results of Pneumocystis jirovecii in both sputum and blood. After treatment with Granulocyte Colony-Stimulating Factor, sulfamethoxazole, and caspofungin, aggravation of lung lesions was discovered and severe interstitial lung disease developed in a short period along with a rapidly increasing leukocyte count. Intravenous methylprednisolone pulse therapy was given, but lung function did not improve, and she finally died after the withdrawal of medical care. CONCLUSIONS: For patients with acute lymphocytic leukaemia infected with Pneumocystis jirovecii, the rapid aggravation of pulmonary lesions in the process of blood recovery and immune reconstitution should raise vigilance against the possibility of IRIS-like reactions. The use of granulocyte stimulating factors may aggravate the inflammatory response in the lungs. The timing, dosage, and duration of treatment of glucocorticoids and the impact of high-dose methylprednisolone pulse therapy on the prognosis of patients should be explored in further research.

Degradation of epigallocatechin and epicatechin gallates by a novel tannase TanHcw from Herbaspirillum camelliae.

BACKGROUND: Herbaspirillum camelliae is a gram-negative endophyte isolated from the tea plant. Both strains WT00C and WT00F were found to hydrolyze epigallocatechin-3-gallate (EGCG) and epicatechin-3-gallate (ECG) to release gallic acid (GA) and display tannase activity. However, no tannase gene was annotated in the genome of H. camelliae WT00C. RESULTS: The 39 kDa protein, annotated as the prolyl oligopeptidase in the NCBI database, was finally identified as a novel tannase. Its gene was cloned, and the enzyme was expressed in E. coli and purified to homogeneity. Moreover, enzymatic characterizations of this novel tannase named TanHcw were studied. TanHcw was a secretary enzyme with a Sec/SPI signal peptide of 48 amino acids at the N-terminus, and it catalyzed the degradation of tannin, methyl gallate (MG), epigallocatechin-3-gallate (EGCG) and epicatechin-3-gallate (ECG). The optimal temperature and pH of TanHcw activities were 30 °C, pH 6.0 for MG and 40 °C, pH 7.0 for both EGCG and ECG. Na+, K+ Mn2+ and Triton-X100, Tween80 increased the enzyme activity of TanHcw, whereas Zn2+, Mg2+, Hg2+, EMSO, EDTA and ß-mercaptoethanol inhibited enzyme activity. Km, kcat and kcat /Km of TanHcw were 0.30 mM, 37.84 s-1, 130.67 mM-1 s-1 for EGCG, 0.33 mM, 34.59 s-1, 105.01 mM-1 s-1 for ECG and 0.82 mM, 14.64 s-1, 18.17 mM-1 s-1 for MG, respectively. CONCLUSION: A novel tannase TanHcw from H. camelliae has been identified and characterized. The biological properties of TanHcw suggest that it plays a crucial role in the specific colonization of H. camelliae in tea plants. Discovery of the tannase TanHcw in this study gives us a reasonable explanation for the host specificity of H. camelliae. In addition, studying the characteristics of this enzyme offers the possibility of further defining its potential in industrial application.

Precise and convenient size barcode on microfluidic chip for multiplex biomarker detection.

The existing multiplex biomarker detection methods are limited by the high demand for coding material and expensive detection equipment. This paper proposes a convenient and precise coding method based on a wedge-shaped microfluidic chip, which can be further applied in multiplex biomarker detection. The proposed microfluidic chip has a microchannel with continuously varying height, which can naturally separate and code microparticles of different sizes. Our data indicate that this method can be applied to code more than 5 or 7 kinds of microparticles, even when their size discrepancies are smaller than 1 µm. Based on these, multiplex biomarker detection can be implemented by using microparticles of different sizes, hence each kind of microparticle that coats one kind of antibody represents the species of targets. This method is simple and easy to operate, with no clogging or sophisticated coding design, showing its significant potential in the area of point-of-care tests (POCT).

Multiple exposures to high concentrations of selenate significantly improve selenate tolerability, red elemental selenium (Se0) and selenoprotein biosynthesis in Herbaspirillum camelliae WT00C.

Herbaspirillum camelliae WT00C is a gram-negative endophyte isolated from the tea plant. It has an intact selenate metabolism pathway but poor selenate tolerability. In this study, microbiological properties of the strain WT00C were examined and compared with other three strains CT00C, NCT00C and NT00C, which were obtained respectively from four, six and eight rounds of 24-h exposures to 200 mM selenate. The selenate tolerability and the ability to generate red elemental selenium (Se0) and selenoproteins in H. camelliae WT00C has significantly improved by the forced evolution via 4-6 rounds of multiple exposures a high concentration of selenate. The original strain WT00C grew in 200 mM selenate with the lag phase of 12 h and 400 mM selenate with the lag phase of 60 h, whereas the strains CT00C and NCT00C grew in 800 mM selenate and showed a relatively short lag phase when they grew in 50-400 mM selenate. Besides selenate tolerance, the strains CT00C and NCT00C significantly improved the biosynthesis of red elemental selenium (Se0) and selenoproteins. Two strains exhibited more than 30% selenium conversion efficiency and 40% selenoprotein biosynthesis, compared to the original strain WT00C. These characteristics of the strains CT00C and NCT00C make them applicable in pharmaceuticals and feed industries. The strain NT00C obtained from eight rounds of 24-h exposures to 200 mM selenate was unable to grow in ≥ 400 mM selenate. Its selenium conversion efficiency and selenoprotein biosynthesis were similar to the strain WT00C, indicating that too many exposures may cause gene inactivation of some critical enzymes involving selenate metabolism and antioxidative stress. In addition, bacterial cells underwent obviously physiological and morphological changes, including gene activity, cell enlargement and surface-roughness alterations during the process of multiple exposures to high concentrations of selenate.

Boosting the Loading of Metal Single Atoms via a Bioconcentration Strategy.

Increasing the mass loading of transition metal single atoms coordinated with nitrogen in carbon-based materials (M-N-C) is still challenging. Herein, inspired by the bioconcentration effect in the living body, a biochemistry strategy for the synthesis of Fe-N-C single atoms is demonstrated. Through introducing ferrous glycinate into the growth of fungus, the Fe atoms are bioconcentrated in hyphae. The highly dispersed Fe-N-C single atoms in hyphae-derived carbon fibers (labeled as Fe-N-C SA/HCF) are prepared by the pyrolysis of Fe-riched hyphae. In the bioconcentration process, the uptake of Fe ions by hyphae promotes the secretion of glutathione and ferritin, which provides additional coordination sites for Fe ions. Accordingly, the mass content of Fe in bioconcentrated Fe-N-C SA/HCF reaches 4.8%, which is 5.3 times larger than that of the sample prepared by the conventional pyrolysis process. The present bioconcentration strategy is further extended to the preparation of Co, Ni, and Mn single atoms. Owing to the high content of Fe-N-C single atoms, Fe-N-C SA/HCF shows the onset potential (Eonset ) of 0.931 V versus reversible hydrogen electrode (RHE) and half-wave potential (E1/2 ) of 0.802 V versus RHE in oxygen reduction reaction measurements, which is comparable to the commercial Pt/C catalysts.

A VIT-like transporter facilitates iron transport into nodule symbiosomes for nitrogen fixation in soybean.

Effective legume-rhizobia symbiosis depends on efficient nutrient exchange. Rhizobia need to synthesize iron-containing proteins for symbiotic nitrogen fixation (SNF) in nodules, which depends on host plant-mediated iron uptake into the symbiosome. We functionally investigated a pair of vacuolar iron transporter like (VTL) genes, GmVTL1a/b, in soybean (Glycine max) and evaluated their contributions to SNF, including investigations of gene expression patterns, subcellular localization, and mutant phenotypes. Though both GmVTL1a/b genes were specifically expressed in the fixation zone of the nodule, GmVTL1a was the lone member to be localized at the tonoplast of tobacco protoplasts, and shown to facilitate ferrous iron transport in yeast. GmVTL1a targets the symbiosome in infected cells, as verified by in situ immunostaining. Two vtl1 knockout mutants had lower iron concentrations in nodule cell sap and peribacteroid units than in wild-type plants, suggesting that GmVTL1 knockout inhibited iron import into symbiosomes. Furthermore, GmVTL1 knockout minimally affected soybean growth under nonsymbiotic conditions, but dramatically impaired nodule development and SNF activity under nitrogen-limited and rhizobia-inoculation conditions, which eventually led to growth retardation. Taken together, these results demonstrate that GmVTL1a is indispensable for SNF in nodules as a transporter of ferrous iron from the infected root cell cytosol to the symbiosome.