Biomimetic metalloporphyrin oxidase modified carbon nanotubes for highly sensitive and stable quantification of anti-oxidants tert-butylhydroquinone in plant oil.

This study constructed a novel biomimetic enzyme electrochemical biosensor based on tetraphenyl metalloporphyrins functionalized multi-walled carbon nanotubes (MWCNTs). The effect of central metal ions on the catalytic activity of tetraphenyl metalloporphyrin biomimetic enzyme was investigated. It was found that the change of central metal ions had a significant effect on the catalytic performance of metalloporphyrin and Zinc(II) tetraphenylporphyrin (ZnTPP) had the most excellent catalytic property. The electrochemical behaviors of tert-butylhydroquinone (TBHQ) on ZnTPP/MWCNTs modified electrode were investigated. It was found that the redox peak current was increased significantly, which was attributed to the redox peak current to the electrocatalytic activity of ZnTPP and the synergistic effect between ZnTPP and MWCNTs. A strong linear relationship was shown in the concentration range of 0.01 to 1000 µM. This electrochemical sensor also had excellent repeatability, storage, and interference resistance. This work provided a simple and sensitive method for the determination of TBHQ.

Improved catalytic performance of carrier-free immobilized lipase by advanced cross-linked enzyme aggregates technology.

The cross-linked enzyme aggregates (CLEAs) are one of the technologies that quickly immobilize the enzyme without a carrier. In this study, ionic liquid with amino group (1-aminopropyl-3-methylimidazole bromide, FIL) was used as the novel functional surface molecule to modify CRL (Candida rugosa lipase, CRL). The enzymatic properties of CRL-FIL-CLEAs were investigated. The activity of CRL-FIL-CLEAs (5.51 U/mg protein) was 1.9 times higher than that of CRL-CLEAs (2.86 U/mg protein) without surface modification. After incubating in a centrifuge tube for 50 min at 60 °C, CRL-FIL-CLEAs still maintained 61% of its initial activity, while the value for CRL-CLEAs was only 22%. After repeated use for five times, compared with the 22% residual activity of CRL-CLEAs, the value of CRL-FIL-CLEAs was 51%. Based on the above results, it was indicated that this method provided a new idea for the effective synthesis of immobilized enzyme.

Development and validation of a prediction model for treatment failure in peritoneal dialysis-associated peritonitis patients: a multicenter study / 南方医科大学学报

OBJECTIVE@#To develop and validate a risk prediction model of treatment failure in patients with peritoneal dialysis-associated peritonitis (PDAP).@*METHODS@#We retrospectively analyzed the data of patients undergoing peritoneal dialysis (PD) in 3 dialysis centers in Jilin Province who developed PDAP between January 1, 2013 and December 31, 2019. The data collected from the Second Hospital of Jilin University and Second Division of First Hospital of Jilin University) were used as the training dataset and those from Jilin Central Hospital as the validation dataset. We developed a nomogram for predicting treatment failure using a logistic regression model with backward elimination. The performance of the nomogram was assessed by analyzing the C-statistic and the calibration plots. We also plotted decision curves to evaluate the clinical efficacy of the nomogram.@*RESULTS@#A total of 977 episodes of PDAP were included in the analysis (625 episodes in the training dataset and 352 episodes in the validation dataset). During follow-up, 78 treatment failures occurred in the training dataset and 35 in the validation dataset. A multivariable logistic regression prediction model was established, and the predictors in the final nomogram model included serum albumin, peritoneal dialysate white cell count on day 5, PD duration, and type of causative organisms. The nomogram showed a good performance in predicting treatment failure, with a C-statistic of 0.827 (95% CI: 0.784-0.871) in the training dataset and of 0.825 (95% CI: 0.743-0.908) in the validation dataset. The nomogram also performed well in calibration in both the training and validation datasets.@*CONCLUSION@#The established nomogram has a good accuracy in estimating the risk of treatment failure in PDAP patients.

Mechanism of Fangji Fulingtang for Treating Acute Kidney Injury Induced by Ischemia-reperfusion Based on Network Pharmacology and Molecular Docking Verification / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Fangji Fulingtang in the treatment of acute kidney injury （AKI） induced by ischemia-reperfusion based on network pharmacology and experimental verification. MethodActive components of Fangji Fulingtang were retrieved from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform （TCMSP） and previous report and targets of these components were predicted by SwissTargetPrediction. The targets of AKI were searched from GeneCards， Online Mendelian Inheritance in Man （OMIM）， the database of gene-disease associations （DisGeNET）， and Therapeutic Target Database （TTD）. Protein-protein interaction （PPI） network was constructed by STRING. Metascape was used for Gene Ontology （GO） term enrichment and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment of core targets. Cytoscape was employed to construct the "medicinal-active component-target-disease" network and “active component-target-pathway” network. AutoDock was applied for molecular docking. Finally， animal experiment was carried out to validate the mechanism of Fangji Fulingtang in treatment of AKI. ResultA total of 137 active components and 858 targets of Fangji Fulingtang， 1 294 targets of AKI， and 267 targets of Fangji Fulingtang in the treatment of AKI were screened out. Phosphoinositide-3-kinase regulatory subunit 1 （PIK3R1）， phosphatidylinositol-4，5-bisphosphate 3-kinase catalytic subunit alpha （PIK3CA）， proto-oncogene tyrosine protein kinase （SRC）， protein kinase B1 （Akt1）， and mitogen-activated protein kinase 3 （MAPK3） were the key anti-AKI targets of Fangji Fulingtang， which were involved in 1 609 GO terms， particularly cell response to lipids， membrane rafts， and protein kinase activity， and 140 KEGG pathways such as PI3K/Akt signaling pathway， chemokine signaling pathway， and Toll-like receptor signaling pathway. Molecular docking showed that the core active components had strong binding affinity to the key targets. The hematoxylin and eosin （HE） staining results indicated that Fangji Fulingtang can significantly improve the pathological state and the serological results suggested that the levels of serum creatinine （SCr） and blood urea nitrogen （BUN） were significantly reduced. ConclusionThis study clarified the mechanism of Fangji Fulingtang in the treatment of AKI and found that Fangji Fulingtang had the multi-component， multi-target， and multi-pathway characteristics in the treatment of AKI. The result lays a foundation for further study of its specific mechanism.

Isolation and Identification of Chemical Constituents in Seeds of Sophora tonkinensis / 中国实验方剂学杂志

ObjectiveTo study the chemical constituents of the seeds of Sophora tonkinensis. MethodThe chemical constituents were isolated and purified by chromatography with MCI resin， silica gel， Sephadex LH-20， and semi-preparative high performance liquid chromatography. Their structures were identified by physicochemical properties， spectral data as well as relevant references. Meanwhile， the antibacterial activities against Helicobacter pylori of these compounds were screened by agar dilution method. ResultA total of 22 compounds were isolated from the methanol extract of the seeds of S. tonkinensis， and characterized as 4′，7-dihydroxy-6-methoxy isoflavone （1）， daidzein （2）， wighteone （3）， dalparvone （4）， 5，7-dihydroxy-4′-methoxyisoflavone （5）， prunetin （6）， formononetin （7）， genistein （8）， 5-methoxydaidzein （9）， ononin （10）， 7，4′-dihydroxyflavone （11）， liquiritigenin （12）， bayin （13）， 2，4-dihydroxybenzoate （14）， methyparaben （15）， 4-hydroxyacetophenone （16）， p-anisaldehyde （17）， methyl indole-3-carboxylate （18）， 4-［β-D-apiofuranoyl-（1→6）-O-β-D-glucopyranosyloxy］ phenylacetonitrile （19）， （-）-methyl dihydrophaseate （20）， methyl canavaliol ester （21）， vomifoliol 3′-O-β-D-apiofuranosyl-（1→6）-β-D-glucopyranoside （22）. ConclusionCompounds 1， 5， 6， 9 and 16 are isolated from S. tonkinensis for the first time， compounds 4， 14， 17-22 are isolated from the genus of Sophora for the first time. In addition， compounds 10 and 13 display moderate antibacterial activities against H. pylori.

Lipase nanogel catalyzed synthesis of vitamin E succinate in non-aqueous phase.

BACKGROUND: In order to improve the stability of vitamin E and broaden its scope of application, an effective solution is to convert vitamin E into its derivatives. This work developed a new Candida rugosa lipase (CRL) nanogel based on modification of ionic liquid with vinyl functional groups. This novel CRL nanogel was used in the preparation process of vitamin E succinate based on the principle of non-aqueous enzymology. At the same time, various factors including enzyme concentration, substrate molar ratio, reaction temperature and reaction time, that affect the yield of vitamin E succinate were optimized and analyzed. RESULTS: Different solvents with various hydrophobicity parameters (LogP values) from -1.3 to 3.5 were studied, it was found that dimethyl sulfoxide (DMSO) had the lowest LogP value among organic solvents but vitamin E succinate had the highest yield in DMSO. Furthermore, the effect of different operating conditions, such as molar ratios of substrate, enzyme concentration, reaction temperature and reaction time was studied. Under the optimal process conditions (enzyme concentration 6 mg mL-1 , substrate molar ratio 4:1, reaction temperature 55 °C and reaction time 15 h), the product yield was 62.58 ± 1.16%. CRL and CRL nanogel were characterized using Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). It was shown that CRL nanogel influenced the catalytic behavior of lipase significantly by changing the structure and surface properties of CRL. CONCLUSION: Novel lipase nanogel was an excellent biocatalyst for enzymatic synthesis of vitamin E succinate. © 2020 Society of Chemical Industry.

Enhancing electrochemical sensing for catechol by biomimetic oxidase covalently functionalized graphene oxide.

Catechol level is an important indicator for evaluating the quality of tea. Therefore, the exploration of a simple and efficient quantitative detection method for catechol has an important significance. In this study, functionalized graphene oxide was synthesized by chemically modifying the surface of graphene oxide. The prepared carrier was covalently combined with biomimetic oxidase iron porphyrin (FePP, the active center of horseradish peroxidase). Ionic liquid as covalent coupling agents was designed as electronic bridge between biomimetic oxidase and graphene oxide. The novel biomimetic biosensor provided a detection range of 50.0-1600.0 µmol/L by modulating under the optimal conditions of the reaction system (FePP concentration is 1.5 × 10-3 mol/L, pH 3.0, Nafion solution dosage 1% and temperature 25 °C), the detection limit is 0.09 µmol/L. The biosensor has excellent stability, repeatability and reproducibility, and is expected to be applied to the rapid detection of catechol in actual tea sample..

The Association Between Serum Leptin Levels and Cardiovascular Events in Patients with Rheumatoid Arthritis.

OBJECTIVE: Cardiovascular diseases (CVDs) are important complications for patients with rheumatoid arthritis (RA). The study aimed to explore whether serum leptin is associated with a increased risk of cardiovascular (CV) events in patients with RA. METHODS: Two hundred twenty-three patients with RA were followed for a mean of 40 (range = 8-42) months. Serum leptin levels were measured at baseline. Cox regression analysis was performed to assess the association between leptin levels and the risk of CV events. RESULTS: The univariate analysis showed that patients with RA with higher serum leptin levels had higher rates of CV events and CV mortality, respectively (P <.001). The logistic regression model showed that leptin was independently related to CVD history (odds ratio = 1.603, 95% confidence interval [CI], 1.329-2.195; P =.005) after adjusting for confounding factors in patients with RA at baseline. The multivariate Cox proportional hazard model suggested that leptin was an independent prognostic factor for CV events in patients with RA after adjustments were made for clinical confounding factors (hazard ratio = 2.467, 95% CI, 2.019-4.495; P <.001). The Kaplan-Meier analysis showed that compared with patients with RA with leptin levels below the median value (≤15.4 mg/L), patients with leptin above the median value (>15.4 µg/L) had a higher rate of CV events (P <.001). CONCLUSION: Leptin was significantly associated with CV events in patients with RA. Elevated serum leptin levels may be a reliable prognostic factor for predicting CV complications in patients with RA.

Dynamic changes of the PGAM1 expression in the mouse testis exposed to single heat stress / 中华男科学杂志

Objective@#To investigate the expression of phosphoglycerate mutase 1 (PGAM1) in the mouse testis after exposure to single heat stress (SHS).@*METHODS@#We randomly assigned 32 C57 male mice to an SHS (n = 16) and a control group (n = 16), the former bathed in water at 43 ℃ and the latter at 25 ℃ for 15 minutes. At 1 and 7 days after exposure, we harvested the testicular tissue for observation of the morphological changes of testicular cells by HE staining and determination of the location and expression of the PGAM1 protein by immunohistochemistry and Western blot.@*RESULTS@#The testis volume of the mice were reduced significantly, the spermatogenic tubules were disorganized, and the cells were reduced in number after heat stress and basically disappeared after 7 days. Immunohistochemistry showed extensive expression of the PGAM1 protein in the testicular spermatogenic tubules of the SHS-exposed mice, significantly higher than in the control group at 1 day after exposure, which was down-regulated in the testis tissue at 7 days, but still markedly higher than that in the control. Western blot exhibited significantly up-regulated expression of the PGAM1 protein after heat stress compared with that in the control group.@*CONCLUSIONS@#The expression of the PGAM1 protein undergoes dynamic changes in the mouse testis after exposed to single heat stress, which is related to heat stress-induced proliferation and division of testicular spermatogenic cells.

Taeniid cestodes in Tibetan foxes (Vulpes Ferrilata) detected by copro-PCR: Applications and challenges.

Tibetan foxes (Vulpes ferrilata) have been confirmed as the main wild definitive hosts in echinococcosis transmission in the eastern Tibetan Plateau. However, little information is available about the epidemiology in wildlife from the perspective of the Taeniidae family, which is essential knowledge in understanding the epidemiology and phylogeography of cestode species in the Tibetan plateau. Therefore, in this study, we used copro-PCR techniques, by amplifying nad1 and cox1 gene fragments, to detect the taeniid species from Tibetan fox feces collected in Shiqu County, (Sichuan Province, China), eastern Tibetan Plateau. Phylogenetic relationships between amplified sequences and existed Taenia species genotypes were evaluated. Then, the maximum prevalence (positive PCR results from at least one primer pair) and the conservative prevalence (positive PCR results from at least two primer pairs) were calculated. Thirty-six Tibetan fox feces were analyzed. Echinococcus multilocularis (conservative prevalence ± 95% CI: 22.2% ± 13.6%; maximum prevalence ± 95% CI: 33.3% ± 15.4%) and E. shiquicus (2.8 ± 5.4%; 8.3 ± 9.0%) was detected. Meanwhile, DNA fragments of T. polyacantha were detected with high similarity to NCBI sequences (cox1, 94.0%) and to the larva sample DNA sequenced in this study (93.4%), and were supported by phylogenetic analysis. Thus, T. polyacantha might infect Tibetan foxes (5.6% ± 7.5%, 11.1% ± 10.3%). Our limited findings in the epidemiology of parasitic Taenia species suggest that sylvatic transmission cycles for a more species-rich Taeniid community must be established between wild canids and small mammals than just for the two Echinococcus species. Besides, discrepancies in different primer pairs in detecting the taeniid species were evaluated. The sensitivity of some widely used universal primer pairs was poor in detecting Taenia species from canid copro-DNA samples. It is still challenging to the development of effective taeniid species-specific molecular markers especially for non-zoonotic species.

Acetylcholinesterase biosensors based on ionic liquid functionalized carbon nanotubes and horseradish peroxidase for monocrotophos determination.

Long-term and excessive use of monocrotophos (MPs) pesticide leads to an accumulation of MPs residues in agricultural products. Electrochemical biosensor technology was developed as a simple and efficient method for detecting MPs. However, commercial acetylcholinesterase (AChE) sensors are not applied in practical MPs detection due to poor stability and reliability. In this study, the advantages of functionalized carbon nanotubes (Cl/MWCNTs) and a bi-enzyme system (horseradish peroxidase (HRP)/AChE) were combined, a novel bi-enzyme electrode (Cl/MWCNTs/HRP/AChE/GCE) was constructed. Under optimal conditions, the bi-enzyme sensor had a wide detection range of 1.0 × 10-11 to 1.0 × 10-7 mol/L and low detection limit of 4.5 × 10-12 mol/L. The proposed AChE biosensor exhibited excellent stability and sensitivity for MPs determination and presented a promising tool for monitoring food safety.

Analysis of Driver-Passenger Relationship and Restoration of Accident Process Based on 3D Laser Scanning Technology / 法医学杂志

Objective To discuss the application of 3D laser scanner and computer technology in restoration of the accident scene and reconstruction of the accident process, as well as identification of the driver-passenger relationship. Methods The scene of a traffic accident, the accident vehicle and the vehicle of the same type as accident vehicle were scanned using 3D laser scanner. The accident scene, traces and accident vehicle were integrated using computer technology to restore the accident scene, and the accident process was reconstructed and analyzed by combining the characteristics of the body injuries. Results By restoring the accident scene and reconstructing the accident process with 3D laser scanner, it was determined that Wu was in the driving seat at the time of the accident. Conclusion It is more objective and scientific to use 3D laser scanning technology to restore the accident scene, reconstruct the accident process and analyze the moving track of the driver and passengers in the vehicle. It will help to improve the accuracy of forensic identification of road traffic accidents.

Biomimetic oxidase sensor based on functionalized surface of carbon nanotubes and iron prophyrins for catechol detection.

A novel and highly stable biomimetic oxidase sensor system was designed for catehol detection. FePP used as biomimetic horseradish peroxidase (HRP) was immobilized onto modified multi-walled carbon nanotubes (MWCNTs). Functional groups such as -OH, -NH2 and -COOH were introduced onto the surface of MWCNTs to provide biomimetic microenvironment for iron porphyrins (FePP). Stable biomimetic enzyme electrode has been developed to detect catechol as a simple, economical and efficient method. At optimal condition, the detection limit of OH-MWCNTs/FePP/Nafion was 3.754 × 10- 6 M. After stored at - 4 °C for 35 days, the oxidation current value still maintained 98.3% of initial activity. In repetitive nature test, relative standard deviation (RSD) of oxidation current remained within 1.0% after ten consecutive measurements in the same concentration of catechol solution, while most of reported oxidase sensor was within 2.0% under the same condition.

Decipherment of ancient literature about fresh use,crude use and processed use of Puerariae Lobatae Radix / 中国中药杂志

Puerariae Lobatae Radix is a traditional Chinese medicine,which was first recorded in Shennong Classic of Materia Medica,and was recorded in many ancient books. Its main effect is to relieve muscles to expel heat,produce saliva and promote eruption,invigorate splenic yang and stop diarrhea. CNKI and Wanfang Data were searched in this paper with the words " Pueraria", " puerarin usage" and " puerarin application" as the key words,and it was found that the puerarin usage characteristics were rarely reported.Therefore,the application characteristics of fresh use,crude use and processed use of Puerariae Lobatae Radix in ancient books were summarized in this paper,in order to provide a reference for the modern development of Puerariae Lobatae Radix.

Imaging characteristics of patients with large vestibular aqueduct syndrome and its relationship with the acoustically evoked short latency negative response / 中华耳鼻咽喉头颈外科杂志

Objective@#To explore the imaging characteristics of large vestibular aqueduct syndrome (LVAS) patients and their relationship with the acoustically evoked short latency negative response (ANSR), so as to provide reference for the diagnosis of LVAS.@*Methods@#Clinical data of 174 patients(334 ears) with LVAS diagnosed and treated by the Department of Otorhinolaryngology Head and Neck Surgery of the First Affiliated Hospital of Guangxi Medical University, from October 2009 to December 2017 were retrospectively analyzed, including 117 males and 57 females, aged from 5 months to 47 years old, with the median age of 4 years and 4 months. ABR and imaging data of patients were collected. Midpoint diameter and the outlet diameter of the vestibular aqueduct were measured on CT images, the midpoint diameter of the intraosseous parts and the extraosseous parts of enlarged endolymphatic sac(EES) were measured on MRI images. The correlation between the above measurements was analyzed by Pearson test using SPSS 17.0. According to whether ASNR was detected in ABR, the above data were divided into two groups, and the differences of the above imaging measurements were compared by the Independent-Sample Test.@*Results@#The average midpoint diameter of the vestibular aqueduct was (1.87±0.58) mm (±s, the following was the same), and the outlet diameter was (3.07±0.99) mm on CT; the average midpoint diameter of the intraosseous parts in enlarged endolymphatic sac(EES) was (2.39±1.37) mm, and the extraosseous parts was (2.50±2.18) mm on MRI. There was a correlation between the four measurements (P<0.05), among which the midpoint diameter of vestibular aqueduct was strongly positively correlated with the outlet diameter (r=0.760), and the remaining pairs were weakly correlated. ASNR was detected in 241 ears (72.16%,241/334) and undetected in 93 ears (27.84%, 93/334) of the 334 ears with LVAS. Midpoint diameter and the outlet diameter of the vestibular aqueduct in no ASNR group were smaller than the ASNR group, and the difference was statistically significant (t value was 2.814 and 2.754, P<0.05). There was no significant difference in the midpoint diameter of the intraosseous parts and the extraosseous parts of enlarged endolymphatic sac between the two groups, and the difference was no statistically significant(t value was 0.101 and 0.683, P>0.05).@*Conclusions@#There is a strong positive correlation between the midpoint diameter of vestibular aqueduct and the outlet diameter in LVAS patients. There is a certain correlation between the size of vestibular aqueduct and the size of endolymphatic sac. The smaller the diameter of vestibular aqueduct, the lower the occurrence rate of ASNR.

Pharmaceutics research advances in oral administration of puerarin / 中国中药杂志

Puerarin is a naturally occurring isoflavone C-glycoside,isolated from the root of Pueraria lobata,which has attracted extensive attention in the medical circles because of its various pharmacological effects,such as vasodilation,cardioprotection,neuroprotection,antioxidant,anticancer,anti-inflammation,alleviating pain,promoting bone formation,inhibiting alcohol intake,and attenuating insulin resistance. However,its low oral bioavailability has limited its clinical application. This review gives a comprehensive summary of the researches on physicochemical properties,pharmacokinetics( absorption,distribution,metabolism and excretion,pharmacokinetic parameters) in oral administration,and pharmaceutics research strategies of puerarin in recent years,and the in vivo behavior difference between multicomponent and single component environment was also summarized. The reasons( low water solubility,poor membrane permeability,short half-life,inhibition of P-gp efflux and first-pass metabolic effects of intestinal enzymes,etc.) for low bioavailability were concluded and the idea that multicomponent enviroment would affect the bioavailability was clarified. The aim of this review is to provide literature basis for the development of new dosage forms and new technologies for multivariate compound drug delivery system to improve the bioavailability of oral puerarin,and to propose ways to improve the bioavailability of BCS Ⅳ drugs derived from traditional Chinese medicine by fully enlarging the synergistic effect of multi-components or reasonably using the inhibitory effect between components.

Acetylcholinesterase biosensor based on functionalized surface of carbon nanotubes for monocrotophos detection.

Monocrotophos (Ops) has been widely used as pesticide in crop production but simultaneously could accumulate in the nature and seriously impact food safety and human health. It is necessary to develop a high sensitivity biosensor for accurate and fast detection of OPs. In this study, multi-walled carbon nanotubes (MWCNTs) were selected as acetylcholinesterase (AChE) carrier and their surface was modified by introducing different functional groups (-SH, -NH2, -Cl, -OH), hydrophobic alkyl groups (-CH3, -(CH2)2CH3, -(CH2)7CH3, -(CH2)15CH3) and ionic liquids (-IL1, -IL2). The interaction mechanism of MWCNTs functionalized surface and AChE has been revealed by studying characteristics of AChE immobilized on different carrier surface. Finally, compared with reported references and above other modifiers, we found that MWCNTs surface modified by -IL1 was the best carrier for AChE and the detection limit of IL1-MWCNTs/AChE/GCE was 3.3 × 10-11 M. At optimum reaction condition (pH 7.0, AChE loading 0.25 U, Inhibition time 14 min), storability test indicated reactivity of IL1-MWCNTs/AChE/GCE remained above 98.5% within two weeks. For real vegetable sample detection, the recoveries of IL1-MWCNTs/AChE/GCE were found to be between 90.0% and 104%. These results demonstrated novel biosensors could act as device of high sensitivity for accurate and fast detection of OPs.

Quick separation and enzymatic performance improvement of lipase by ionic liquid-modified Fe3O4 carrier immobilization.

To promote the activity and stability of immobilized porcine pancreatic lipase (PPL), novel carrier was combined with special immobilization method. Enzymatic activity was enhanced after immobilized onto ionic liquid modified magnetic Fe3O4 by electrostatic adsorption. Activity of immobilized enzyme (PPL-IM/BF4-Fe3O4@CA) reached 596 U/g PPL. Through the combination of electrostatic adsorption and embedding immobilization methods, we improve binding force between the carrier and enzyme, and further enhance the efficiency and stability of immobilized enzyme. The activity of PPL-IM/BF4-Fe3O4@CA after repeated third use was 78%. After storage at room temperature for 5 days, the residual activity was 89%. Enzymatic properties and catalytic kinetics of immobilized enzymes were studied, and the effect mechanism of ionic liquid modified Fe3O4 on PPL was revealed. The effect of ionic liquid on the carrier structure was investigated by characterization of XRD, FT-IR, SEM and TG. The mechanism and enzymatic properties of immobilized PPL via electrostatic adsorption and embedding were analyzed. A novel and efficient immobilized PPL was developed.

The analysis of ABR about newborns in the neonatal intensive care unit after failing hearing screening / 重庆医学

Objective To investigate the auditory brainstem response (ABR) of newborns in the neonatal intensive care unit (NICU) after hear screening failure.Methods To test ABR of 833 healthy newborns with no perinatal diseases at the clinic,and 425 newborns born in NICU who failed the hearing screening of monaural or both-ear from March 2014 to May 2015.Results 49.6% of children′s wave V response thresholds were ≥30 dB in the NICU group and 36.1% children′s wave V response thresholds were ≥30 dB in healthy group.The hearing abnormality rate of the NICU group was significantly higher than that of the healthy group(P<0.05);The average auditory thresholds healthy of the group[(19.76±6.59)dB] was significantly lower than those of the NICU group[(41.52±20.35)dB](P<0.05);both ear latency for waves Ⅰ,Ⅲ and Ⅴ and interpeak latency for waves Ⅰ-Ⅴ in healthy group were significantly shorter than those in NICU group (P<0.05).Conclusion The hearing loss extent of the NICU group is greater than that of the healthy group.The ABR abnormality reflects auditory pathway is abnormal.

Establishment of A549 cell line with stable expression of HIF1α mediated by lentiviral vector / 重庆医学

Objective To establish the A549 cell line with stable expression of HIF1α by using lentiviral vector system.Methods Primers were designed and synthesized with human HIF1α gene coding sequence by the National Center of Biotechnogical Information(NCBI) as the template.HIF1α was amplified by PCR.The HIF1α fragment recycled by enzyme digestion was recombined with prepared lentiviral vector HBLV-RFP-Puro.The recombinant plasmid was identified by PCR and gene sequencing.The recombinant plasmid and the auxiliary plasmid were co-transfect into 293T cell.After filtration and concentration of packaged virus,the viral titer was detected by using the dilution counting method.The prepared lentivirus was infected A549 cells.The drug screening was adopted to stabilize the transfected cell line.The transfection effect was detected and observed by fluorescence microscope and Western blotting.Results The HIF1α fragment amplified by PCR was successfully verified and the recombinant plasmid was successfully constructed by PCR and gene sequencing identification.High-titer LV-HIF1α was obtained by successful package.After LV-HIF1α infecting A549 cells,the cells showed the red fluorescence by fluorescence microscope.The expression level of HIF1α in the LV-HIF1α group was significant higher than that in the control group by Western blot.Conclusion The 549 cell line with HIF1α stable expression mediated by lentivirus is constructed successfully.