Escherichia albertii isolated from the bloodstream of a patient with liver cirrhosis in China: A case report.

A rare case of bacteremia caused by Escherichia albertii, in a 50-year-old male with liver cirrhosis was reported. Clear, colorless, and circular colonies were recovered on blood agar after 24 h of aerobic incubation at 37 °C. The isolate was identified as E. albertii using MALDI-TOF/MS and confirmed by the diagnostic triplex-PCR targeting clpX, lysP, and mdh genes. The administration of piperacillin/tazobactam intravenously (4.5g every 8 hours) for 3 days was effective. This study suggested that specific strains of E. albertii have been implicated in causing extraintestinal infections in humans, similar to extraintestinal pathogenic E. coli (ExPEC). However, a comprehensive understanding of the underlying pathogenic mechanisms requires further exploration.

How does new infrastructure impact the competitiveness of the tourism industry?--Evidence from China.

Infrastructure construction related to the new generation of information technology and 5G technology is an important measure taken by the Chinese government to promote regional economic development. Large-scale infrastructure investment is being carried out simultaneously in China's core and peripheral regions. The COVID-19 pandemic has dealt a severe blow to China's tourism industry, and the application of new technologies seems to blur the spatial boundaries of the tourism industry. Therefore, it is debatable whether the zealous development of large investment projects can really improve the competitiveness of the regional tourism industry. This paper discusses this topical issue by empirically analyzing data from 31 Chinese provinces and cities from 2008-2019 and draws the following conclusions (1) The continuous expansion of new infrastructure investment in China indeed has a positive effect on improving China's overall tourism competitiveness. However, the inverted U-shaped relationship between the two shows that China should not blindly expand the scale of infrastructure construction and make appropriate investment according to the regional industrial development level. (2) Although convergent infrastructure plays an important role in regional industrial competitiveness, the marginal effect has begun to weaken, so the problem of scale inefficiency needs to be addressed. In contrast, the input of innovation infrastructure is insufficient to enhance industrial competitiveness and can be moderately increased to achieve better results. (3) China's core economic areas have a good driving effect on new infrastructure investment, but the original technological innovation and transformation-type facilities are still the key to limiting the improvement of industrial competitiveness. Peripheral areas are more passive recipients with strong demand. Therefore, investment in various types of infrastructure can drive regional development.

Associations of MALAT1 and its functional single nucleotide polymorphisms with cancer.

BACKGROUND: Systematic research on the associations between vital single nucleotide polymorphisms (SNPs) in MALAT1 and cancer risk was still lacking. Thus, we performed this study. MATERIALS AND METHODS: The literature searches were until April 1, 2022. The pooled association-analysis results were assessed by odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) in three genetic models. In addition, we explored the potential functions of MALAT1 and its vital SNPs based on several public websites. RESULTS: Eighteen articles about four SNPs (rs619586, rs664589, rs1194338, and rs3200401) involving 11,843 cancer cases and 14,682 controls were collected. Rs619586, rs664589, and rs1194338 were associated with cancer risk (all P-value < 0.05). Each SNP of the three was significantly related to the risk of colorectal cancer (CRC), and rs619586 correlated with hepatocellular carcinoma (HCC) risk (all P-value < 0.05). The three SNPs might affect the transcription factor, promoter, or enhancer functions. MALAT1 expressed significantly higher in CRC and HCC than in normal tissues. The respective area under the receiver operating characteristic curve of MALAT1 for CRC and HCC patients was 0.783 and 0.864. Moreover, survival analysis indicated that MALAT1 might be a potential prognostic marker of CRC and HCC (all relevant P-value < 0.05). CONCLUSIONS: The functional SNPs in MALAT1 correlated with cancer risk. MALAT1 and its vital functional SNPs might be potential biomarkers for predicting the risk and prognosis of two types of cancer, especially CRC. Further investigations are needed to confirm our present findings.

Comparative genomics of Chinese and international isolates of Escherichia albertii: population structure and evolution of virulence and antimicrobial resistance.

Escherichia albertii is a recently recognized species in the genus Escherichia that causes diarrhoea. The population structure, genetic diversity and genomic features have not been fully examined. Here, 169 E. albertii isolates from different sources and regions in China were sequenced and combined with 312 publicly available genomes (from additional 14 countries) for genomic analyses. The E. albertii population was divided into two clades and eight lineages, with lineage 3 (L3), L5 and L8 more common in China. Clinical isolates were observed in all clades/lineages. Virulence genes were found to be distributed differently among lineages: subtypes of the intimin encoding gene eae and the cytolethal distending toxin gene cdtB were lineage associated, and the second type three secretion system (ETT2) island was truncated in L3 and L6. Seven new eae subtypes and one new cdtB subtype (cdtB-VI) were identified. Alarmingly, 85.9 % of the Chinese E. albertii isolates were predicted to be multidrug-resistant (MDR) with 35.9 % harbouring genes capable of conferring resistance to 10 to 14 different drug classes. The majority of the MDR isolates were of poultry source from China and belonged to four sequence types (STs) [ST4638, ST4479, ST4633 and ST4488]. Thirty-four plasmids with some carrying MDR and virulence genes, and 130 prophages were identified from 17 complete E. albertii genomes. The 130 intact prophages were clustered into five groups, with group five prophages harbouring more virulence genes. We further identified three E. albertii specific genes as markers for the identification of this species. Our findings provided fundamental insights into the population structure, virulence variation and drug resistance of E. albertii.

[Analysis of paclitaxel concentration in rat plasma by Raman spectrums combined with partial least square].

Partial least square (PLS) combining with Raman spectroscopy was applied to develop predictive models for plasma paclitaxel concentration detection. In this experiment, 312 samples were scanned by Raman spectroscopy. High performance liquid chromatography (HPLC) was applied to determine the paclitaxel concentration in 312 rat plasma samples. Monte Carlo partial least square (MCPLS) method was successfully performed to identify the outliers and the numbers of calibration set. Based on the values of degree of approach ( D a ), moving window partial least square (MWPLS) was used to choose the suitable preprocessing method, optimum wavelength variables and the number of latent variables. The correlation coefficients between reference values and predictive values in both calibration set ( R c2) and validation set ( R p2) of optimum PLS model were 0.933 1 and 0.926 4, respectively. Furthermore, an independent verification test was performed on the prediction model. The results showed that the correlation error of the 20 validation samples was 9.36%±2.03%, which confirmed the well predictive ability of established PLS quantitative analysis model.

Multidrug-Resistant Escherichia albertii: Co-occurrence of ß-Lactamase and MCR-1 Encoding Genes.

Escherichia albertii is an emerging member of the Enterobacteriaceae causing human and animal enteric infections. Antimicrobial resistance among enteropathogens has been reported to be increasing in the past years. The purpose of this study was to investigate antibiotic resistance and resistance genes in E. albertii isolated from Zigong city, Sichuan province, China. The susceptibility to 21 antimicrobial agents was determined by Kirby-Bauer disk diffusion method. The highest prevalence was tetracycline resistance with a rate of 62.7%, followed by resistance to nalidixic acid and streptomycin with a rate of 56.9 and 51.0%, respectively. All isolates were sensitive or intermediate susceptible to imipenem, meropenem, amoxicillin-clavulanic acid, and levofloxacin. Among 51 E. albertii isolates, 15 were extended-spectrum ß-lactamase-producing as confirmed by the double disk test. The main ß-lactamase gene groups, i.e., blaTEM, blaSHV, and blaCTX-M, were detected in17, 20, and 22 isolates, respectively. Furthermore, four colistin-resistant isolates with minimum inhibitory concentrations of 8 mg/L were identified. The colistin-resistant isolates all harbored mcr-1 and blaCTX-M-55. Genome sequencing showed that E. albertii strain SP140150 carried mcr-1 and blaCTX-M-55 in two different plasmids. This study provided significant information regarding antibiotic resistance profiles and identified the co-occurrence of ß-lactamase and MCR-1 encoding genes in E. albertii isolates.

Transferrin-conjugated liposomes loaded with novel dihydroquinoline derivatives as potential anticancer agents.

A series of 1,2-dihydroquinoline derivatives were synthesized and evaluated for cytotoxicity in HeLa, Hep G2 and 6HEK-293T cell lines. EEDQ2 was identified as a promising anti-cancer agent with low IC50 in HeLa (18.55µg/ml) and Hep G2 (14.53µg/ml) cells. For improving the antitumor activity and tumor selectivity of EEDQ2, we prepared transferrin (Tf)-modified liposomes (LPs) to deliver EEDQ2. When HeLa and Hep G2 cells were treated with LP-delivered EEDQ2, the ROS level was significantly enhanced, and mitochondrial membrane potential was reversed. Tf-LPs improved cell uptake of EEDQ2 by about 3.7 times compared with non-targeted LPs. These data suggest that Tf-LPs delivering EEDQ2 is a promising strategy to treat cancer.

Defining the Genetic Features of O-Antigen Biosynthesis Gene Cluster and Performance of an O-Antigen Serotyping Scheme for Escherichia albertii.

Escherichia albertii is a newly described and emerging diarrheagenic pathogen responsible for outbreaks of gastroenteritis. Serotyping plays an important role in diagnosis and epidemiological studies for pathogens of public health importance. The diversity of O-antigen biosynthesis gene clusters (O-AGCs) provides the primary basis for serotyping. However, little is known about the distribution and diversity of O-AGCs of E. albertii strains. Here, we presented a complete sequence set for the O-AGCs from 52 E. albertii strains and identified seven distinct O-AGCs. Six of these were also found in 15 genomes of E. albertii strains deposited in the public database. Possession of wzy/wzx genes in each O-AGC strongly suggest that O-antigens of E. albertii were synthesized by the Wzx/Wzy-dependent pathway. Furthermore, we performed an O-antigen serotyping scheme for E. albertii based on specific antisera against seven O-antigens and a high throughput xTAG Luminex assay to simultaneously detect seven O-AGCs. Both methods accurately identified serotypes of 64 tested E. albertii strains. Our data revealed the high-level diversity of O-AGCs in E. albertii. We also provide valuable methods to reliably identify and serotype this bacterium.

A Differential Reflective Intensity Optical Fiber Angular Displacement Sensor.

In this paper, a novel differential reflective intensity optical fiber angular displacement sensor was proposed. This sensor can directly measure the angular and axial linear displacement of a flat surface. The structure of the sensor probe is simple and its basic principle was first analyzed according to the intensity modulation mechanisms. Secondly, in order to trim the dark output voltage to zero, the photoelectric conversion circuit was developed to adjust the signals. Then, the sensor model including the photoelectric conversion circuit has been established, and the influence of design parameters on the sensor output characteristic has been simulated. Finally, the design parameters of the sensor structure were obtained based on the simulation results; and an experimental test system was built for the sensor calibration. Experimental results show that the linear angular range and the sensitivity of the sensor were 74.4 and 0.051 V/°, respectively. Its change rules confirm the operating principle of the sensor well.

Actively Targeted Nanoparticles for Drug Delivery to Tumor.

BACKGROUND: Nanomedicine is an emerging therapeutic modality. Nanoparticles (NPs) are potential vehicles for delivery of anticancer therapeutics. NPs can be designed to facilitate tumor drug delivery both by passive and active targeting mechanisms. Passive targeting of NPs to tumors can be achieved through the enhanced permeability and retention (EPR) effect. Meanwhile, actively targeted NPs can be designed based on two different targeting mechanisms, ligand-directed targeting to the tumor cells and tumor microenvironment (TME)-directed targeting. METHODS: We searched for and reviewed recently published literature on actively targeted NPs. Progress in this field was summarized in several focus areas, including methods for targeting of tumor cells and for targeting TME. Advantages and limitations of each approach were discussed. RESULTS: This article covers data from 240 recent publications and provided numerous examples of ligand-directed NPs targeting tumor cell-selective surface receptors. Targeting ligands discussed include proteins such as transferrin and antibodies, as well as low molecular weight agents, such as peptides, aptamers, carbohydrates, and folate. In addition, extensive discussions of TME targeting NPs, designed to release drug in response to TME-specific stimuli, such as low pH, tumor-selective enzymes, and unique characteristics of tumor neovasculature, are also included in this review. In general, many novel actively targeting strategies have been developed and encouraging data have been reported in numerous settings, both in vitro and in animal studies. CONCLUSION: Active targeting of NPs has experienced rapid growth as a field of research and is continuously expanding. There are now some early examples of efforts on clinical translation and reported clinical trials on these NPs. Future development of actively targeted NPs depends on better understanding of the many factors affecting the behavior of NPs in vivo and likely involves combining the approaches of targeting the tumor cells and of targeting components of the TME.

Comparative pharmacokinetics of a proliposome formulation of Ginkgo biloba extract and Ginaton in rats by a sensitive ultra performance liquid chromatography-tandem mass spectrometry method.

As a novel oral drug delivery system, proliposome was applied to improve the solubility of active components of Ginkgo biloba extract (GbE). There are currently few reports focusing on the pharmacokinetic characteristics of proliposome of GbE (GbP). A rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of active components of GbP and a commercial tablet product (Ginaton) in rat plasma was developed and successfully validated. The method was applied to the comparative pharmacokinetic evaluation of GbP and Ginaton in rat plasma. The results indicated that GbP has a significant effect on absorption, elimination and bioavailability of flavonoids and terpenoid lactones in comparison with Ginaton. The obtained results would be helpful for evaluating the absorption mechanism in the gastrointestinal tract in pharmacokinetic level and guiding the development of the novel oral drug delivery system.

Near Infrared Spectroscopic Combined with Partial Least Squares and Radial Basis Function Neural Network to Analyze Paclitaxel Concentration in Rat Plasma.

Paclitaxel is known as one of the most effective anticancer drugs. Near Infrared Spectroscopy (NIRS), a rapid, precise and non-destructive approach of analysis, has been widely used for qualitative and quantitative detection. The present study aims to analyze the plasma paclitaxel concentration with NIRS. Various batches of plasma samples were prepared and the concentration of paclitaxel was determined via high performance liquid chromatography tandem mass spectrometry (LC-MS/MS). The outliers and the number of calibration set were confirmed by Monte Carlo algorithm combined with partial least squares (MCPLS). Since NIR spectra may be contaminated by signals from background and noise, a series of preprocessing were performed to improve signal resolution. Moving window PLS and radical basis function neural network (RBFNN) methods were applied to establish calibration model. Although both PLS and RBFNN models are well-fitting, RBFNN-established model displayed better qualities on stability and predictive ability. The correlation coefficients of calibration curve and prediction set (Rc(2) and Rp(2)) are 0.9482 and 0.9544, respectively. Moreover, independent verification test with 20 samples confirmed the well predictive ability of RBFNN model.

Aeration and fermentation strategies on nisin production.

OBJECTIVES: To optimize nisin production in Lactococcus lactis by using different aeration and fermentation strategies. RESULTS: The nisin titer and specific nisin production rate reached maximum values of 11,900 IU/ml and 4110 IU/g/h, respectively, in aerobic batch fermentation with glucose as C source. These values were higher than in anaerobic batch fermentation (10,700 IU/ml and 3260 IU/g/h, respectively). The maximum specific nisin production rates appeared earlier in aerobic batch fermentation, which suggests that nisin production is stimulated by aeration. Different fermentation strategies were compared: maximum nisin production (15,400 IU/ml) was achieved with fed-batch fermentation with a variable rate of feeding under aerobic conditions. CONCLUSION: Nisin production can be stimulated by aeration, which goes against the typical conditions involving strict anaerobiosis.

Proliposomes containing a bile salt for oral delivery of Ginkgo biloba extract: Formulation optimization, characterization, oral bioavailability and tissue distribution in rats.

Proliposomes containing a bile salt were developed to improve the oral bioavailability of Ginkgo biloba extract (GbE). GbE loaded proliposomes (P-GbE) were successfully prepared by spray drying method. The formulation was optimized using the response surface methodology. FE-SEM, DSC, and FT-IR were used to study the surface morphology and molecular state of proliposomes, and demonstrated key interactions between the formulation ingredients. In vitro studies showed delayed release and enhanced dissolution of Ginkgo flavonoids and terpene lactones from GbE proliposomes. Proliposomes significantly enhanced GbE absorption in the gastrointestinal tract and decreased its elimination. The bioavailabilities of quercetin, kaempferol, isorhmnetin, ginkgolide A, ginkgolide B and ginkgolide C from proliposomes relative to the control were 245%, 211%, 264%, 203%, 333%, and 294%, respectively. Proliposomes were shown to selectively deliver GbE to critical target tissues. In conclusion, development of proliposomes formulation for GbE solved the problem of its poor oral bioavailability, prolonged its duration of action, and increased drug distribution in critical tissues, especially in the brain, therefore, warrant further investigation.

Self-assembly of electrospun polymer nanofibers: a general phenomenon generating honeycomb-patterned nanofibrous structures.

A general phenomenon that electrospun polymer nanofibers self-assemble into honeycomb-patterned nanofibrous structures (HNFSs) is reported. We used electrospinning to produce charged polymer nanofibers, which were kept in liquid state (wet) on landing on the substrates by appropriately controlling the electrospinning conditions. Driven by the competitive actions of surface tension and electrostatic repulsion, these charged wet nanofibers self-assemble into the HNFSs. Fabrication of the well-defined three-dimensional HNFSs was successfully demonstrated for three different polymers, that is, polyacrylonitrile, polyvinyl alcohol, and polyethylene oxide. The pore diameter of the obtained honeycomb structures spans a wide range from micrometers to over 200 µm with depths as large as over 150 µm. The pore walls are composed of uniaxially aligned polymer nanofibers.

[Analysis on heavy metal concentrations in agricultural soils of Baoshan, Shanghai].

Based on the acquisition of heavy metal data from 216 topsoil samples of the agricultural land in Baoshan District, a typical region of Shanghai City, the content, distribution characteristics and sources of the heavy metals in agricultural soil of Shanghai Baoshan District were analyzed with the methods of combining multivariate statistics and geo-statistical. The results show that the average concentrations of the Cd, Hg, As, Cr, Pb, Cu and Zn in agricultural soil of Baoshan District are 0.195, 0.148, 7.44, 82.5, 29.1, 33.2 and 124.5 mg x kg(-1), they are lower than the secondary standards of the national soil environment; but the average concentrations of the Cd, Hg, Cr, Pb, Cu and Zn are more than background values of soil in Shanghai. Especially the Cd, Hg, Zn, they are 1.50, 1.48, 1.45 times higher than the background values, showing a net cumulative trend. The results of correlation analysis and factor analysis show that the sources of these elements can be divided into three categories; the Zn, Cd, Hg and Pb as one class; the Cr and Cu as another class; the As in a separate category. The concentrations of the former two classes are much higher than the background value, implying mainly from various human activities; the content of the As is almost the same as the background value of soil, it has the lowest degree of variation. Spatial structure analysis shows that the distribution of the As is influenced by the soil structural variations, such as soil parent material, topography, and other elements are mainly affected by random factors of human activities. Through the probability distribution of contour lines of the critical value, it can be found that the Cd, Zn, Cr, Cu, Hg come mainly from the point sources of pollution, but the source of Pb is relatively dispersed.

[Computer aided design and manufacture of the removable partial denture framework].

This paper demonstrates the successful application of a novel approach to the computer aided design (CAD) of removable partial denture (RPD) framework. Firstly, we get the data of the partially edentulous cast, a mandibular Kennedy Class II, through a 3D-optical grating measuring system after corresponding pretreatment. Then, the reverse engineering software and 3D CAD software was used to design basis, big conjunction, clasp, small conjunction of the RPD framework. Finally 3D surface model of the RPD framework was created in preparation for direct manufacture using rapid prototyping (RP) methods and foundry. The result indicated that the RPD framework was fabricated successfully and the resulting frameworks provided a satisfactory fit.