Peripapillary RNFL cross-sectional area and its association with other parameters in a Chinese population.

BACKGROUND: Quantitative analysis of retinal nerve fibers is important for the diagnosis and treatment of optic nerve diseases. Peripapillary retinal nerve fiber layer (RNFL) cross-sectional area may give a more accurate quantitative assessment of retinal nerve fibers than RNFL thickness but there have been no previous reports of the peripapillary RNFL cross-sectional area or other parameters. The purpose of the current study was to determine peripapillary RNFL cross-sectional area and its association with other factors in an adult Chinese population. METHODS: RNFL cross-sectional area was measured during peripapillary circular optical coherence tomography (OCT) scan with a diameter of 12° centered on the optic disc. Correlation between RNFL cross-sectional area and other parameters was evaluated by linear regression analysis in a cross-sectional study of an adult Chinese population. RESULTS: A total of 2404 eyes from 2404 subjects were examined. Multivariate linear regression analysis showed that larger RNFL cross-sectional area correlated with younger age (p < 0.001), female gender (p = 0.001), no history of diabetes (p = 0.012) and larger optic disc area (p < 0.001). CONCLUSIONS: Peripapillary RNFL cross-sectional area is correlated positively with optic disc area, suggesting that eyes with larger optic discs have thicker RNFL. Further studies are needed to confirm whether this correlation is due to differences in the numbers of retinal nerve fibers or other factors.

The beneficial potential of protein hydrolysates as prebiotic for probiotics and its biological activity: a review.

Probiotics are not only a food supplement, but they have shown great potential in their nutritional, health and therapeutic effects. To maximize the beneficial effects of probiotics, it is commonly achieved by adding prebiotics. Prebiotics primarily comprise indigestible carbohydrates, specific peptides, proteins, and lipids, with oligosaccharides being the most extensively studied prebiotics. However, these rapidly fermenting oligosaccharides have many drawbacks and can cause diarrhea and flatulence in the body. Hence, the exploration of new prebiotic is of great interest. Besides oligosaccharides, protein hydrolysates have been demonstrated to enhance the expression of beneficial properties of probiotics. Consequently, this paper outlines the mechanism underlying the action of protein hydrolysates on probiotics, as well as the advantageous impacts of proteins hydrolysates derived from various food sources on probiotics. In addition, this paper also reviews the currently reported biological activities of protein hydrolysates. The aim is a theoretical basis for the development and implementation of novel prebiotics.

Improvement of average magnetic field measurement based on magnetic-field-sensitive Ramsey fringes.

Accurate magnetic field measurement is the key to evaluating the second-order Zeeman effect. The conventional method is to deduce the magnetic field by determining the center frequency of the magnetic-field-sensitive Ramsey fringes. In this Letter, we present a more rigorous theory for this method and demonstrate that the current peak-searching method has a non-negligible sub-Hz or even larger deviation. We introduce an improved method that considers more parameters and a strict formula that can correct the deviation and suppress it to below 0.1 Hz. Corresponding experiments on the 85Rb atomic fountain demonstrate that this improved method is expected to enhance the precision of magnetic field measurement and improve the atomic fountain clock.

The Role of Cryoprotective Agents in Liposome Stabilization and Preservation.

To improve liposomes' usage as drug delivery vehicles, cryoprotectants can be utilized to prevent constituent leakage and liposome instability. Cryoprotective agents (CPAs) or cryoprotectants can protect liposomes from the mechanical stress of ice by vitrifying at a specific temperature, which forms a glassy matrix. The majority of studies on cryoprotectants demonstrate that as the concentration of the cryoprotectant is increased, the liposomal stability improves, resulting in decreased aggregation. The effectiveness of CPAs in maintaining liposome stability in the aqueous state essentially depends on a complex interaction between protectants and bilayer composition. Furthermore, different types of CPAs have distinct effective mechanisms of action; therefore, the combination of several cryoprotectants may be beneficial and novel attributed to the synergistic actions of the CPAs. In this review, we discuss the use of liposomes as drug delivery vehicles, phospholipid-CPA interactions, their thermotropic behavior during freezing, types of CPA and their mechanism for preventing leakage of drugs from liposomes.

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in the seafood from an important fishing area in the East China Sea and a comparison between seafood from different origins.

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in a variety of coastal marine seafood from the Wentai fishing area, which is in proximity to highly urbanized areas and provides a significant portion of the marine aquatic products in Eastern China. Specifically, total PAHs ranged from 320 to 2500 ng/g d.w., whereas carcinogenic PAHs ranged from 21 to 92 ng/g d.w. According to the source diagnosis, the PAHs in the seafood were generally from sources highly related to fossil fuel. Thus, it is necessary to control the unintentional use of fossil fuels and optimize the energy structure in the terrestrial area nearby. Moreover, the food chain structure and the environmental behavior of PAHs through the food chain, which are relevant to dietary risk, were assessed. The δ15N values fell in a narrow range, which indicates a relatively short food chain, which is due to overfishing in this area. Furthermore, in this shortened food chain, the trophic magnification factors (TMFs) ranged from 0.23 to 6.6, which were generally higher than those in more complex food chains. The cancer risk (ILCR) ranged from 2.2 × 10-8 to 2.2 × 10-6. It is noted that the carcinogenic risk of consuming yellow croaker, which is one of the most popular seafood among people on the east coast of China, was the highest. In conclusion, trophic magnification implied a possible elevated risk through this marine food chain, and overfishing may have increased the uncertainty associated with TMF estimations.

Cordyceps militaris Immunomodulatory Protein Promotes the Phagocytic Ability of Macrophages through the TLR4-NF-κB Pathway.

Enhancing the phagocytosis of immune cells with medicines provides benefits to the physiological balance by removing foreign pathogens and apoptotic cells. The fungal immunomodulatory protein (FIP) possessing various immunopotentiation functions may be a good candidate for such drugs. However, the effect and mechanism of FIP on the phagocytic activity is limitedly investigated. Therefore, the present study determined effects of Cordyceps militaris immunomodulatory protein (CMIMP), a novel FIP reported to induce cytokines secretion, on the phagocytosis using three different types of models, including microsphere, Escherichia Coli and Candida albicans. CMIMP not only significantly improved the phagocytic ability (p < 0.05), but also enhanced the bactericidal activity (p < 0.05). Meanwhile, the cell size, especially the cytoplasm size, was markedly increased by CMIMP (p < 0.01), accompanied by an increase in the F-actin expression (p < 0.001). Further experiments displayed that CMIMP-induced phagocytosis, cell size and F-actin expression were alleviated by the specific inhibitor of TLR4 (p < 0.05). Similar results were observed in the treatment with the inhibitor of the NF-κB pathway (p < 0.05). In conclusion, it could be speculated that CMIMP promoted the phagocytic ability of macrophages through increasing F-actin expression and cell size in a TLR4-NF-κB pathway dependent way.

Strategies towards PM2.5 attainment for non-compliant cities in China: A case study.

The northern part of the Yangtze River Delta (YRD) region in China suffers from high concentrations of fine particular matter (PM2.5) during the past years yet received much less attention compared to the other parts of the YRD region. In this study, we integrated observational data, control policies and strategies, and air quality simulations to develop PM2.5 attainment demonstration by year 2030 for the city of Bengbu, which represents a typical non-compliant city in the northern YRD region. In 2018, the annual average PM2.5 concentration in Bengbu was 51.8 µg/m3, which was 48 % higher than the standard of 35 µg/m3 set by the National Ambient Air Quality Standards (NAAQS). Different future emission scenarios were developed for year 2025 as mid-term and year 2030 as long-term. Integrated meteorology and air quality modeling system together with monitoring data was applied to predict the air quality under the future emission scenarios. Results show that when a conservative emission reduction ratio of 40 % was assumed for surrounding regions, the annual average PM2.5 concentration in Bengbu could meet the target value by 2030, in which case emissions of SO2, NOx, PM2.5, VOCs, and NH3 need to be reduced by 70.6 %, 43.5 %, 47.2 %, 33.4 %, and 47.5 %, respectively. PM2.5 concentration in Bengbu is not only controlled by local emission reductions but also affected by emission reductions of surrounding regions as well as contribution from long-range transport. More attentions need to be paid to the control of VOCs emissions in the near future to avoid increase of ozone concentrations while reducing PM2.5. Our results provide scientific support for the local government to formulate future air pollution prevention and control strategies, sub-regional joint-control among surrounding cities, as well as trans-regional joint-control between the north China and the YRD region.

TMT-MS/MS proteomic analysis of the carbohydrate-active enzymes in the fruiting body of Pleurotus tuoliensis during storage.

BACKGROUND: The fruiting body of Pleurotus tuoliensis deteriorates rapidly after harvest, causing a decline in its commercial value and a great reduction in its shelf life. According to the present research, carbohydrate-active enzymes (CAZymes) may cause the softening, liquefaction and autolysis of mature mushrooms after harvest. To further understand the in vivo molecular mechanism of CAZymes affecting the postharvest quality of P. tuoliensis fruiting bodies, a tandem mass tags labelling combined liquid chromatography-tandem mass spectrometry (TMT-MS/MS) proteomic analysis was performed on P. tuoliensis fruiting bodies during storage at 25 °C. RESULTS: A total of 4737 proteins were identified, which had at least one unique peptide and had a confidence level above 95%. Consequently, 1307 differentially expressed proteins (DEPs) were recruited using the criteria of abundance fold change (FC) >1.5 or < 0.67 and P < 0.05. The identified proteins were annotated by dbCAN2, a meta server for automated CAZymes annotation. Subsequently, 222 CAZymes were obtained. Several CAZymes participating in the cell wall degradation process, including ß-glucosidase, glucan 1,3-ß-glucosidase, endo-1,3(4)-ß-glucanase and chitinases, were significantly upregulated during storage. The protein expression level of CAZymes, such as xylanase, amylase and glucoamylase, were upregulated significantly, which may participate in the P. tuoliensis polysaccharide degradation. CONCLUSIONS: The identified CAZymes degraded the polysaccharides and lignin, destroying the cell wall structure, preventing cell wall remodeling, causing a loss of nutrients and the browning phenomenon, accelerating the deterioration of P. tuoliensis fruiting body. © 2020 Society of Chemical Industry.

Comparison of developmental toxicity of different surface modified CdSe/ZnS QDs in zebrafish embryos.

Quantum dots (QDs) are new types of nanomaterials. Few studies have focused on the effect of different surface modified QDs on embryonic development. Herein, we compared the in vivo toxicity of CdSe/ZnS QDs with carboxyl (-COOH) and amino (-NH2) modification using zebrafish embryos. After exposure, the two CdSe/ZnS QDs decreased the survival rate, hatching rate, and embryo movement of zebrafish. Moreover, we found QDs attached to the embryo membrane before hatching and the eyes, yolk and heart after hatching. The attached amount of carboxyl QDs was more. Consistently, the Cd content in embryos and larvae was higher in carboxyl QD-treatment. We further observed that the two QDs caused zebrafish pericardial edema and cardiac dysfunction. In line with it, both carboxyl and amino QDs up-regulated the transcription levels of cardiac development-related genes, and the levels were higher in carboxyl QD-treated groups. Furthermore, the chelator of Cd2+ diethylene triamine pentacetate acid could partially rescued the developmental toxicity caused by the two types of QDs suggesting that both the nature of QDs and the release of Cd2+ contribute to the developmental toxicity. In conclusion, the two CdSe/ZnS QDs have developmental toxicity and affect the cardiac development, and the carboxyl QDs is more toxic possibly due to the higher affinity and more release to embryos and larvae. Our study provides new knowledge that the surface functional modification of QDs is critical on the development on aquatic species, which is beneficial to develop and applicate QDs more safely and environment-friendly.

[Study on binding kinetics profiles of tea polyphenols-α-glucosidase interaction].

The combination index(CI) method was used to evaluate the combination inhibition mechanism of epicatechin gallate(ECG) and other tea polyphenols [epigallocatechin gallate(EGCG) and gallocatechin gallate(GCG)] on α-glucosidase. Herein, using ECG as research object, the surface plasmon resonance(SPR) analysis were employed to study the binding affinities and kinetic parameters of three tea polyphenols components on α-glucosidase, respectively. The concentration-time curve mathematical model of the drug in the unstirred water layer(the adjacent region of α-glucosidase) established previously by our group was used to evaluate the concentration-time curves of the tea polyphenols in the α-glucosidase vicinity. The prediction model of drug-α-glucosidase binding kinetics established by our group was used to evaluate the dynamic process of drug-α-glucosidase binding kinetics of different oral administration processes of ECG. Using acarbose as a reference, the accuracy of the model prediction was judged based on the difference between the prediction results and the actual clinical performance. Using the mathematical model of drug-α-glucosidase interaction, the drug-α-glucosidase binding kinetic characteristic curves of ECG in different administration processes were obtained, which indirectly proved that the synergistic effect of multi-component combination of traditional Chinese medicine and the clinical characteristics of repeat administration were scientific and reasonable.

[Effect of shikonin on function of rheumatoid arthritis fibroblast like synoviocytes].

To observe the effect of shikonin on the proliferation, migration, adhesion and invasion of rheumatoid arthritis(RA) fibroblast like synoviocytes induced by tumor necrosis factor-α(TNF-α), and to explore its mechanism of action from aspects of protein kinase B(Akt) and mitogen activated protein kinase(MAPK) signaling pathways. TNF-α(20 ng·mL~(-1)) was used in this experiment to induce human RA fibroblast like synovial cell line(MH7 A). After addition of different concentrations of shikonin(0.025, 0.05, 0.1 pmol·L~(-1)), the proliferation, migration, adhesion and invasion ability of MH7 A cells were detected by MTT test, scratch test, adhesion test, Transwell invasion test, respectively. Protein expression of Akt and MAPK signaling pathway molecules in MH7 A cells was detected by Western blot. The results showed that as compared with the control group, TNF-α could significantly induce the proliferation, migration, adhesion and invasion of MH7 A cells, and increase the phosphorylation level of Akt, JNK, p38 and extracellular regulatory protein kinase(ERK). As compared with the TNF-α group, shikonin had no significant effect on TNF-α-induced proliferation of MH7 A cells after 24 h treatment, and it could reduce the TNF-α-induced proliferation of MH7 A cells in a concentration dependent manner after 48 h treatment. Shikonin also significantly reduced the TNF-α-induced migration, adhesion, invasion and phosphorylation levels of Akt, JNK, p38, ERK in MH7 A cells within 24 h. These results suggested that shikonin could reduce the proliferation, migration, adhesion and invasion ability of MH7 A cells induced by TNF-α, and its mechanism may be related to the down-regulation of Akt and MAPK signaling pathway activation.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside eliminates ischemia/reperfusion injury-induced H9c2 cardiomyocytes apoptosis involving in Bcl-2, Bax, caspase-3, and Akt activation.

OBJECTIVE: This study was designed to explore the protective effect of 2,3,5,4'-tetrahydroxystilbene-2-O-ß-d-glucoside (TSG) against ischemia/reperfusion (I/R) injury-induced cardiomyocytes apoptosis. METHODS: The H9c2 cell I/R injury model was induced by simultaneous shortage of nutrients and oxygen. TSG administration (0.10, 0.25, and 0.50 mM) was performed before and during I/R stimulation. Cell apoptosis was evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Expression of cell-related proteins was detected to assess the effect of TSG on cell apoptosis. RESULTS: I/R injury induced significant cell apoptosis. Significantly decreased Bcl-2 and increased Bax, caspase-3, and p-Akt expression ( P < 0.01) was detected in the cell model of I/R injury. In contrast, TSG administration eliminated all the changes induced by I/R injury in a dose-dependent manner. Compared with the H9c2 cell model of I/R injury, the H9c2 cells treated with 0.50 mM TSG showed the lowest cell apoptosis percentage, the highest expression of Bcl-2, and the lowest expression of Bax, caspase-3, and p-Akt ( P < 0.01). CONCLUSION: We confirmed that the protective effect of TSG against I/R injury-induced cell apoptosis in H9c2 in vitro was associated with the Bcl-2/Bax ratio, caspase-3, and Akt activation.

Musa basjoo regulates the gut microbiota in mice by rebalancing the abundance of probiotic and pathogen.

Musa basjoo is a kind of popular slimming fruit in southern China. However, even though the trophic component and physiological effect are well studied, its internal mechanism in reconstructing gut microbiota remains unclear. In this study, maturity of M. basjoo were divided into four levels. Results indicated that M. basjoo in level Ⅱ (with 35% maturity) represented the greatest increase in the growth in vitro of probiotics, Lactobacillus plantarum FMNP01 and Lactobacillus casei FMNP02. After feeding M. basjoo with the middle dose (2.67 g/kg·BW) to mice for 21 days, gut microbiota from mice feces was isolated and sequenced. Results of 16SrDNA sequencing showed that the scattered genera of gut microbiota were significantly gathered. The amounts of different pathogens were decreased, while probiotics such as genera Bacteroides and Roseburia were significantly increased (p < 0.05). Results of function prediction indicated that the reconstruction of gut microbiota may due to the change in carbohydrate transportation, biosynthesis of cell wall, cell membrane, and cell envelope. This study has drawn a basic mechanism in reconstructing gut microbiota by feeding M. basjoo and lay out a foundation for further reach on the interaction between human as diner and M. basjoo as food.

AURKA contributes to the progression of oral squamous cell carcinoma (OSCC) through modulating epithelial-to-mesenchymal transition (EMT) and apoptosis via the regulation of ROS.

Oral squamous cell carcinoma (OSCC) is known as one of the most common cancer influencing the head and neck region. However, the molecular mechanisms revealing OSCC progression is largely unclear. Aurora kinase A (AURKA) is a serine-threonine kinase that functions in mitotic spindle formation and chromosome segregation, and is associated with the progression of human cancers. But its role in regulating OSCC development has not yet been investigated. In the study, we found that AURKA expression was up-regulated in OSCC cell lines and tumor specimens from patients. OSCC patients with high expression of AURKA exhibited a significant decreased overall survival rate. In vitro, AURKA knockdown markedly reduced the proliferation, migration and invasion of OSCC cells using cell counting kit-8 (CCK-8), EdU, colony formation and transwell analysis. EMT was suppressed by AURKA silence, as evidenced by the up-regulated expression of E-cadherin and down-regulated Vimentin in OSCC cells. In addition, apoptosis was markedly induced by AURKA inhibition through promoting the expression of cleaved Caspase-3 and poly (ADP)-ribose polymerase (PARP). Reactive oxygen species (ROS) production was also markedly enhanced in AURKA-knockdown OSCC cells. Importantly, we found that repressing ROS generation using its scavenger of n-acetylcysteine (NAC) significantly abolished AURKA silence-induced apoptosis, accompanied with restored proliferation and EMT. In vivo, AURKA knockdown notably inhibited tumor growth. Therefore, knockdown of AURKA suppressed cell proliferation, migration and invasion, and also induced apoptosis and ROS generation in OSCC possibly via the production of ROS, demonstrating that AURKA inhibition might represent a novel therapeutic target for the prevention of OSCC.

Immunological effects of the intraparenchymal administration of allogeneic and autologous adipose-derived mesenchymal stem cells after the acute phase of middle cerebral artery occlusion in rats.

BACKGROUND: Adipose-derived mesenchymal stem cell (ADMSC) therapy can promote recovery from cerebral ischemia; however, more information regarding appropriate sources of ADMSCs is required. This study was aimed at analyzing the immunogenicity of rat ADMSCs by comparing the immunological effects of intraparenchymal administration of allogeneic ADMSCs (allo-ADMSCs) and autologous ADMSCs (auto-ADMSCs) after the acute phase of middle cerebral artery occlusion (MCAO) in rats. METHODS: Allo- or auto-ADMSCs from rats (1 × 106 cells) were transplanted into Lewis rats 8 days post MCAO. The immunogenicity of ADMSCs was analyzed using coculture with T lymphocytes. The in vivo immune response induced by rat ADMSCs and the viability, migration, and differentiation of transplanted ADMSCs were detected using immunohistochemistry. Apoptosis within the populations of transplanted cells were detected using a TUNEL assay. Infarct volume was detected by 2,3,5-triphenyltetrazolium chloride staining. Post-treatment neurological function was evaluated using a modified neurological severity score and rotarod test. Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: Compared with allo-ADMSCs, auto-ADMSCs showed lower immunogenicity and evoked weaker immunological responses. Allo-ADMSCs evoked significantly stronger protein expression of interleukin-2 and interferon-gamma, as well as the local accumulation of CD4+ T lymphocytes, CD8+ T lymphocytes, and microglial cells. This indicates that auto-ADMSCs may contribute to higher survival rates, longer survival time, wider migratory scope, and fewer apoptotic cells. In addition, a small number of transplanted auto-ADMSCs expressed astrocyte-like and neuron-like markers 28 days after transplantation. We did not observe surviving transplanted allo-ADMSCs at this time point. We also found that auto-ADMSCs induced a greater degree of functional recovery and a greater reduction in infarct volume than allo-ADMSCs 28 days after transplantation. CONCLUSIONS: Auto-ADMSCs were more effective than allo-ADMSCs in promoting recovery and reducing the infarct volume of MCAO rats. This could be associated with better viability, migratory ability, and differentiation potential, as well as a lower rate of apoptosis. Confirmation of the superiority of auto-ADMSCs and clarification of the underlying mechanisms will provide a theoretical basis for the improved clinical treatment of cerebral infarction.

Deficits in go/no-go task performance in male undergraduate high-risk alcohol users are driven by speeded responding to go stimuli.

BACKGROUND: Response disinhibition plays an important role in addictive behaviors. However, results of studies on the performance on response inhibition tasks of individuals evidencing potentially problematic levels of alcohol drinking are mixed. OBJECTIVES: We assessed conditions under which persons with a relatively high risk of alcohol dependence show inhibition deficits in such tasks and investigated the nature of those deficits. METHODS: Fifty-eight male undergraduate students, 27 of which were high-risk drinkers according to the Alcohol Use Disorders Identification Test, performed a go/no-go inhibition task with differing percentages of no-go trials (50% vs. 25%), stimulus presentation times (600 vs. 200 ms), and types of go and no-go stimuli (alcohol related vs. -unrelated). Response inhibition was indexed by response time (RT) to go trials and response accuracy on go and no-go trials. RESULTS: There were no differences between low- and high-risk drinkers on any of the three outcome measures under the 600-ms stimulus presentation condition. Under the 200-ms condition, the high-risk drinkers showed faster RTs to go stimuli, and more errors on both go- and no-go trials than the low-risk drinkers, irrespective of type and percentage of no-go stimuli. However, the accuracy differences between the two groups disappeared after controlling for the RT on go trials, suggesting a speed-accuracy trade-off. CONCLUSION: High-risk drinkers' response inhibition deficits are not restricted to alcohol-related cues and are especially likely to occur under conditions prompting fast responding. These findings could be used to inform treatment, suggesting the promotion of strategies aimed at preventing high-risk alcohol users from making quick decisions.

Doped graphene for metal-free catalysis.

Graphene has attracted increasing attention in different scientific fields including catalysis. Via modification with foreign metal-free elements such as nitrogen, its unique electronic and spin structure can be changed and these doped graphene sheets have been successfully employed in some catalytic reactions recently, showing them to be promising catalysts for a wide range of reactions. In this review, we summarize the recent advancements of these new and interesting catalysts, with an emphasis on the universal origin of their catalytic mechanisms. We are full of hope for future developments, such as more precisely controlled doping methods, atom-scale surface characterization technology, generating more active catalysts via doping, and finding wide applications in many different fields.

The influence of N-doped carbon materials on supported Pd: enhanced hydrogen storage and oxygen reduction performance.

N-doped graphene has become an important support for Pd in both hydrogen storage and catalytic reactions. The molecular orbitals of carbon materials (including graphene, fullerene, and small carbon clusters) and those of the supported Pd species will hybrid much stronger as N dopants are introduced, owing to the increased electrostatic attraction at the interface. This enhances the carbon substrates' catching force for the supported Pd, preventing its leaching and aggregation in many practical applications. The better dispersion and stabilization of Pd nanoparticles, which are induced by various carbon supports with N-doping, are pleasing to us and could increase their efficiency and facilitate their recycling during various reaction processes in several fields.

[Structure and function of class 1 integron in clinical isolates of Klebsiella pneumoniae].

To investigate molecular mechanism of multi-resistance of Klebsiella pneumoniae and its spreading, 179 strains isolated from different clinical samples in the period of 2002-2007 with serious resistance to 14 anti-bacterial agents were examined. Among them, 118 (65.9%) were resistant to at least two anti-bacterial agents; 36.3% (65/179) were found to contain class 1 integrons. There was a significant difference for resistance rate between the integron positive and the negative groups, especially for antimicrobial agents of aminoglycosides, quinolones and sulfonamides (P<0.01). Gene cassette structures of the class 1 integrons in these bacteria were analyzed and their resistance genes were further cloned and tested for antibiotic resistance activities. Fifteen gene cassettes were identified with dfrA17-aadA5 being the most popular form. Three recombinant plasmids pET28a-dhfr17, pET28a-dhfr17-orfF and pET28a-dhfr17-orfF-aadA2 were cloned from a gene cassette of dhfr17-orfF-aadA2. When introduced into a recipient E. coli strain BL21, all of them rendered resistance to co-trimoxazole, with minimum inhibitory concentration (MIC) value up to 256 µg/µL. The E. coli BL21 carrying pET28a- dhfr17 or pET28a-dhfr17-orfF had the same MIC value of 8 µg/µL to streptomycin as the recipient strain without plasmid. However, the E. coli carrying pET28a-dhfr17-orfF-aadA2 was resistant to streptomycin with MIC level up to 256 µg/µL. In conclusion, class 1 integrons were regularly identified in Klebsiella pneumoniae. They mainly carry resistance genes against antimicrobial agents of aminoglycosides and sulfonamide. Transferable plasmid carrying integrons with resistance genes may play an important role in resistance spreading among bacterial species.

Identification and characterization of the WOX Gene Family revealed two WUS Clade Members associated with embryo development in Cunninghamia lanceolata.

The WUSCHEL-related homeobox (WOX) gene family is vital for plant development and stress response. In this study, we conducted a comprehensive analysis of WOX genes in Cunninghamia lanceolata (C. lanceolata) and subsequently explored the potential roles of two ClWOX genes within the WUS clade. In total, six ClWOX genes were identified through a full-length transcriptome analysis. These genes, exhibiting conserved structural and functional motifs, were assigned to the ancient clade and Modern/WUS clade, respectively, through a phylogenetic analysis. Our expression analysis indicated that these ClWOX genes were highly expressed in the middle and late developmental stages of zygotic embryos in C. lanceolata. Moreover, only ClWOX5 and ClWOX6 within the Modern/WUS clade exhibited transcriptional activity, and their expressions were also induced in response to auxin and wounding. Overexpression of ClWOX5 and ClWOX6 in Arabidopsis caused a partially sterile phenotype, resulting in a very low seed setting rate. Transcriptomic analysis revealed that expressions of many embryo-defective (EMB) genes, phytohormone-related genes, and transcription factors (TFs) were dramatically altered in ClWOX5 and ClWOX6 transgenic plants, which suggested that ClWOX5 and ClWOX6 may play specific important roles in embryo development via complex gene networks. In addition, overexpression of ClWOX5 and ClWOX6 in leaf segments promoted shoot regeneration in tobacco, indicating that ClWOX5 and ClWOX6 can promote plant regeneration and could be used to improve genetic transformation. In conclusion, these results help to elucidate the function of the WOX gene and provide a valuable basis for future studies of the developmental regulation and applications of WOX genes in C. lanceolata.