[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.

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.

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.

Genetic diversity and potential transmission of Escherichia albertii in a poultry breeding rural village.

Escherichia albertii is an emerging foodborne pathogen causing diarrhea. Though various animals, especially poultry, serve as reservoirs, the transmission of E. albertii among reservoirs and the risk to humans remain unclear. This study investigated an E. albertii infected infant with poultry exposure and collected samples from contact persons, poultries, and environment to better understand the transmission dynamics of E. albertii. One E. albertii isolate from contact person, seven isolates from poultries, and six isolates from environment were recovered, respectively. Whole genome sequencing analysis showed that eight strains derived from poultry or environment and classified as ST4633, shared great similarity (cgSNP ≤ 20). However, the patient-derived strain ESA311 had a cgSNP difference of 1165 with human strain ESA339, and differed from poultry and environmental strains (cgSNP range 2417 to 14997), suggesting a distant relatedness. Whole genome phylogeny showed several human-derived E. albertii strains were clustered with those from animal origins. Our results suggested that family-breeding poultry constituted a possible reservoir of E. albertii, with the environment acting as a crucial vector for the spread of these bacteria, posing a risk to humans. Further poultry surveillance is needed to elucidate public health risks associated with E. albertii infection.

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.

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.

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.

[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.