Microbiology Spectrum
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2022
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IF 9.043
Feiyang Zhang,Xiangjin Yan,Jiawei Bai,Li Xiang,Manlin Ding,Qin Li,Biying Zhang,Qinghua Liang,Yingshun Zhou
BolA has been characterized as an important transcriptional regulator, which is induced in the stationary phase of growth and is often associated with bacterial virulence. This study was initiated to elucidate the role of the BolA in the virulence of K. pneumoniae. Using a mouse infection model, we revealed bolA mutant strain yielded significantly decreased bacterial loads in the liver, spleen, lung, and kidney, and failed to form liver abscesses. Gene deletion demonstrated that the bolA was required for siderophore production, biofilm formation, and adhesion to human colon cancer epithelial cells HCT116. Quantitative reverse transcriptase PCR (RT-qPCR) indicated that BolA could impact the expression of pulK, pulF, pulE, clpV, vgrG, entE, relA, and spoT genes on a genome-wide scale, which are related to type II secretion system (T2SS), type VI secretion system (T6SS), guanosine tetraphosphate (ppGpp), and siderophore synthesis and contribute to fitness in the host. Furthermore, the metabolome analysis showed that the deletion of the bolA gene led to decreased pools of five metabolites: biotin, spermine, cadaverine, guanosine, and flavin adenine dinucleotide, all of which are involved in pathways related to virulence and stress resistance. Taken together, we provided evidence that BolA was a significant virulence factor in the ability of K. pneumoniae to survive, and this was an important step in progress to an understanding of the pathways underlying bacterial virulence.IMPORTANCE BolA has been characterized as an important transcriptional regulator, which is induced in the stationary phase of growth and affects different pathways directly associated with bacterial virulence. Here, we unraveled the role of BolA in several phenotypes associated with the process of cell morphology, siderophore production, biofilm formation, cell adhesion, tissue colonization, and liver abscess. We also uncovered the importance of BolA for the success of K. pneumoniae infection and provided new clues to the pathogenesis strategies of this organism. This work constitutes a relevant step toward an understanding of the role of BolA protein as a master regulator and virulence factor. Therefore, this study is of great importance for understanding the pathways underlying K. pneumoniae virulence and may contribute to public health care applications.
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COMPOSITES PART B-ENGINEERING
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2022
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IF 11.322
Shao-Dong Xu,Song Gu,Xiao-Lu Pu,Yan-Fang Xiao,Jia-Hui Lu,Yu-Zhong Wang,Li Chen
Simultaneously improving the thermal conductivity and fire safety of the polymeric thermal management materials (PTMMs) still remains a challenge. In this work, through reaction-induced phase separation (RIPS), co-continuous networks were in situ formed between polyetherimide (PEI) and epoxy resin (EP) cured with either commercially available 4,4′-diaminodiphenyl sulfone (DDS) or the synthesized bis(4-aminophenyl) phenylphosphonate (BAPP). Boron nitride nanosheets (BNNSs) were selectively localized in the interfacial region between the EP-rich and PEI-rich phases as the thermally conductive fillers ; therefore the thermally conductive networks were constructed. BNNSs and BAPP simultaneously endowed the composites with enhanced thermal conductivity and expected fire safety. In detail, the EP BAPP /PEI/BNNS composite with barely 1 wt% BNNSs showed a thermal conductivity increment over 67%; and both the heat and smoke release were greatly suppressed in cone calorimetry : the peak heat release rate (PHRR) reduced by 58%, total heat release (THR) by 56% and total smoke production (TSP) by 46%, compared with the reference. The successful application of the RIPS method in constructing in situ thermally conductive networks provided promising perspectives for designing versatile PTMMs.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Yun-fei Zhang,Chun-hui Zhang,Yu-feng Liu,Dan Li,Jian-hui Xu,Lei Li,Qi Wu,Jin-hong Fan,Lu-ming Ma
Herein, the SiC-Fe 0 powders were mechanically synthesized and employed for activation of peroxymonosulfate (PMS) to remove florfenicol (FLO). Compared to Fe 0 /PMS system, up to a 3.97-fold increase in degradation rates of 20 mg/L FLO was observed by 25% ( w / w ) SiC-Fe 0 /PMS system in 5 mins, which could be attributed to the increased specific surface area and electron transfer rate of SiC-Fe 0 . Both the radical and non-radical processes were involved in the SiC-Fe 0 /PMS system, in which 1 O 2 and • O 2 − played the dominant role in the FLO degradation and SO 4 •− as well as • OH also participated in the system. ROSs investigation suggested that 1 O 2 , • O 2 − , SO 4 •− were mainly generated from the decomposition of PMS and • OH was mainly derived from the ZVI (or Fe 2+ )-catalyzed activation of O 2 . Meanwhile, H* has a nonnegligible role in PMS activation or the transformation of iron species. Five intermediates of FLO in SiC-Fe 0 /PMS system were identified and a significant removal of the overall toxicity was observed. The degradation pathways of FLO were proposed to be hydrolysis, hydroxylation and dechlorination. Besides, this SiC-Fe 0 /PMS system shows effective removal rate for 2-chlorophenol, acetaminophen, tetrabromobisphenol A and carbamazepine, and the FLO-polluted surface water and artificial wastewater. Overall, this study demonstrated that SiC-Fe 0 was promising in practical application and provided new insights into the generation mechanisms of ROSs in the ZVI/PMS system.
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Antioxidants
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2022
·Vol. 11
·期 8
·1530
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IF 7.675
Qingxiu Liu,Wenxiang Li,Shimeng Huang,Lihong Zhao,Jianyun Zhang,Cheng Ji,Qiugang Ma
The development of single enantiomers with high efficiency and low toxic activity has become a hot spot for the development and application of drugs and active additives. The aim of the present study was to investigate the effectiveness of the application of α-lipoic acid with a different optical rotation to alleviate the inflammation response and oxidative stress induced by oxidized fish oil in laying hens. Sixty-four 124-week-old Peking Red laying hens were randomly allocated to four groups with eight replicates of two birds each. The normal group was fed basal diets supplemented with 1% fresh fish oil (FO), and the oxidative stress model group was constructed with diets supplemented with 1% oxidized fish oil (OFO). The two treatment groups were the S-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + S-LA) and the R-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + R-LA) added at 100 mg/kg, respectively. Herein, these results were evaluated by the breeding performance, immunoglobulin, immune response, estrogen secretion, antioxidant factors of the serum and oviduct, and pathological observation of the uterus part of the oviduct. From the results, diets supplemented with oxidized fish oil can be relatively successful in constructing a model of inflammation and oxidative stress. The OFO group significantly increased the levels of the serum inflammatory factor (TNF-α, IL-1β, IL-6, and IFN-γ) and the oxidative factor MDA and decreased the activity of the antioxidant enzyme (T-AOC, T-SOD, GSH-Px, GSH, and CAT) in the oviduct. The addition of both S-LA and R-LA significantly reduced the levels of serum inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), increased the activity of antioxidant indexes (T-AOC, T-SOD, GSH-Px, GSH, and CAT), and decreased the MDA contents in the serum and oviduct. Meanwhile, the supplementation of S-LA and R-LA also mitigated the negative effects of the OFO on the immunoglobulins (IgA and IgM) and serum hormone levels (P and E2). In addition, it was worth noting that the R-LA was significantly more effective than the S-LA in some inflammatory (IL-1β) and antioxidant indices (T-SOD, GSH, and CAT). Above all, both S-LA and R-LA can alleviate the inflammation and oxidative damage caused by oxidative stress in aged laying hens, and R-LA is more effective than S-LA. Thus, these findings will provide basic data for the potential development of α-lipoic acid as a chiral dietary additive for laying hens.Keywords:S-form of α-lipoic acid;R-form of α-lipoic acid;oxidized fish oil;antioxidant;laying hen
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FITOTERAPIA
·
2021
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IF 2.882
Shuang Sun,Eryu Shang,Aixia Ju,Yalun Li,Qian Wu,Qiuhong Li,Yang Yang,Yuyan Guo,Dayu Yang,Shaowa Lv
Aim Cantharidin (CTD), the major component of the anti-cancer medicine obtained from Mylabris cichorii , exerts good inhibitory effects on several cancers, such as liver and breast cancer. However, owing to its toxicity, its oral administration can cause various adverse effects, limiting its clinical applications. Therefore, the development of a novel nano-drug delivery system for CTD would be highly beneficial. Methods A nanostructured lipid carrier (NLC) was designed to actively target CTD to tumor cells using a hyaluronic acid (HA)-decorated copolymer (mPEG-NH 2 ); the NLCs were called HA-mPEG-CTD-NLC. HA-mPEG was synthesized using amidation, and HA-mPEG-CTD-NLC was generated through ultrasonic emulsification in water. The mean hydrodynamic diameter of the particles was approximately 119.3 nm. Results Pharmacokinetic studies revealed that the half-life of HA-mPEG-CTD-NLC and its area under the curve were higher than those of a CTD solution. Further, the plasma clearance rate of HA-mPEG-CTD-NLC was 0.41 times that of the CTD solution, implying a significantly prolonged drug retention time in vivo . Fluorescence in vivo endo -microscopy and optical in vivo imaging revealed that HA-mPEG-CTD-NLC had superior cytotoxicity and targeting efficacy against SMMC-7721 cells. An evaluation of the in vivo anti-tumor activity showed that HA-mPEG-CTD-NLC significantly inhibited tumor growth and prolonged survival in tumor-bearing mice, with a tumor inhibition rate of 65.96%. Conclusions Our results indicate that HA-mPEG-CTD-NLC may have great potential in liver cancer-targeted therapy.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2021
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IF 6.953
Bingqing Huang,Zhigang Zhang,Nengshui Ding,Yuanhong Zhuang,Guoguang Zhang,Peng Fei
To further improve the performance of chitosan in food processing and preservation, this study investigated the grafting of the caffeic acid onto the chitosan in non-enzymatic and enzymatic systems. Result suggested that the caffeic acid was successfully incorporated into the chitosan in the non-enzymatic system, and the grafting ratio of modified chitosan (CA@CTS-N) was 7.49%. Moreover, lipase had a significant positive effect on the grafting reaction of the chitosan, and the modified chitosan prepared in enzymatic system (CA@CTS-E) obtained a higher grafting ratio, which was 11.82%. In both systems, the carboxyl of the caffeic acid was bonded to the amino of the chitosan and formed carbonyl ammonia. After the introduction of foreign group, many changes occurred in the functional properties of the modified chitosan. First, the water solubility of the chitosan was significantly improved from 0.00285 (native chitosan, CTS) to 0.221 (CA@CTS-N) and 0.774 g/100 mL (CA@CTS-E). The caffeoyl had a significant impact on the emulsifying properties of the chitosan. Compared with those of CTS, the modified chitosan had stronger antioxidation and antibacterial activities against Escherichia coli , Staphylococcus aureus , and Candida albicans . Finally, the pork treated with the modified chitosan exhibited longer shelf life than that treated with CTS.
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SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Yuanting Zhu,Guizhou Xu,Xueyao Wang,Xiaowen Ji,Xun Jia,Lin Sun,Xueyuan Gu,Xianchuan Xie
Chlorophenols (CPs) have been listed as priority control pollutants because of their high toxicity and wide range. An In-situ monitoring technique using diffusive gradients in thin films based on porous β-cyclodextrin polymers as binding materials (CDP-DGT), was established to monitor four typical CPs, namely, 4-Chlorophenol (4-CP), 2,4-Dichlorophenol (2,4-DCP), 2,4,5-Trichlorophenol (2,4,5-TCP), 2,4,6-Trichlorophenol (2,4,6-TCP) in water and soils. The performance of CDP-DGT are stable under the conditions of pH 3.5–9.3, ionic strength 0.001–0.500 mol L −1 and dissolved organic matter concentration 0–20 mol L −1 . The adsorption capacities of CDP-DGT for 4-CP, 2,4-DCP, 2,4,5-TCP, 2,4,6-TCP were 57.80 μg cm −2 , 98.82 μg cm −2 , 95.69 μg cm −2 and 98.91 μg cm −2 , respectively. The time-average weighted concentrations of four CPs determined by CDP-DGT at Sanjiangkou wharf (Yangtze river, China) were consistent with the results of grab sampling, indicating the feasibility of CDP-DGT application in actual water. In addition, the distribution of CPs in the red soil of Kunming and paddy soil of Yixing were also studied by CDP-DGT, and the desorption kinetics in the two soils were analyzed with the DIFS model. The higher the soil organic matter content is, the more CPs are distributed in the soil solid phase. CPs in both soils can be partially resupplied to soil solution from the soil solid phase and the higher the partition coefficient for labile CPs is, the stronger the supplement capacity is.
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Scientific Reports
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2021
·Vol. 11
·期 1
·1-10
·
IF 4.38
Chen Huanyu,Cai Ping,Feng Yue,Sun Zhanliang,Wang Yinwen,Chen Yue,Zhang Wei,Liu Nan,Zhou Zhijun
68 Ga-radiolabeled small molecules that specifically target prostate-specific membrane antigen (PSMA) have been extensively investigated, and some of these tracers have been used in the diagnosis of prostate cancer via 68 Ga-positron emission tomography ( 68 Ga-PET). Nevertheless, current 68 Ga-labeled radiotracers show only fair detection rates for metastatic prostate cancer lesions, especially those with lower levels of prostate specific antigen (PSA), which often occurs in the biochemical recurrence of prostate cancer. The goal of this study was to design and synthesize a new PSMA-targeted radiotracer, 68 Ga-SC691, with high affinity for prostate cancer cells and excellent pharmacokinetics. To this end, structural optimization was carried out on the bifunctional group, target motif, and linker while the high affinity targeting scaffold remained. To explore its potential in the clinic, a comparative study was further performed in vitro and in vivo between 68 Ga-SC691 and 68 Ga-PSMA-11, a clinically approved tracer for PSMA-positive prostate cancer. SC691 was radiolabeled to provide 68 Ga-SC691 in 99% radiolabeling yield under mild conditions. High uptake and a high internalization ratio into LNCaP cells were observed in in vitro studies. In vivo studies showed that 68 Ga-SC691 had favorable biodistribution properties and could specifically accumulate on PSMA-positive LNCaP xenografts visualized by micro-PET/CT. This radiotracer showed excellent PET imaging quality and comparable, if not higher, uptake in LNCaP xenografts than 68 Ga-PSMA-11.
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FOOD HYDROCOLLOIDS
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2021
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IF 9.147
Hongxia Gao,Li Ma,Wenxuan Sun,David Julian McClements,Ce Cheng,Huaying Zeng,Liqiang Zou,Wei Liu
Probiotics have many beneficial physiological effects, such as enhancing immunity and regulating intestinal microflora. However, the highly acidic conditions in the stomach and the high bile acid concentration in the small intestine pose challenges to the maintenance of probiotic activity after ingestion. In this study, we examined the possibility of increasing the viability of probiotics under gastrointestinal conditions by encapsulating them within oil-in-water high internal phase emulsions (HIPEs). These emulsions were prepared using whey protein isolate (WPI) and pectin, which were gelled by adding GDL and calcium to form double network HIPE gels. The gel strength, stability, and shear viscosity of the gelled HIPEs increased as the pectin concentration was raised from 0 to 2%. Cryo-SEM analysis showed that the pectin formed a dense hydrogel network in the aqueous phase surrounding the oil droplets in the HIPEs. Probiotics were encapsulated within the gelled HIPEs by dispersing a probiotic powder in the oil phase. Confocal microscopy indicated that the probiotics were mostly distributed in the water, and interfacial phases, with only a few of the probiotics remaining in the oil phase. Encapsulation of the probiotics in the HIPEs increased the number of live cells remaining after a heat treatment and after passage through a simulated gastrointestinal model. The incorporation of pectin into the HIPEs increased the viability of the probiotics, especially after exposure to the gastric phase. This study highlights the potential of HIPEs in preserving probiotic activity, which may be useful for the development of more effective functional foods.
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JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Jiayi Wu,Rui Wang,Yuyao Zhang,Baoliang Chen,Xiaoying Zhu
The interaction force of a typical antibiotic molecule during adsorption has never been experimentally determined and fractionated, which hindered the evolution of removal strategies. In this study, sulfamethoxazole (SMX) as a typical antibiotic was stably immobilized onto an atomic force microscopy (AFM) tip without affecting original properties. The SMX modified AFM tip visualized the potential adsorption sites on a graphene oxide (GO) nanosheet for the first time by mapping the SMX adhesion force distribution. Moreover, the interaction force of a single SMX molecule to GO was determined at 38.6 pN which was subsequently fractionated into the hydrophobic (17.9 pN) and π-π (160.0 pN) attractions as well as the electrostatic repulsion (− 139.3 pN) at pH: 5.7. As compared with highly-ordered pyrolytic graphite (HOPG), the introduced oxygen containing groups on GO not only reduced the hydrophobic interaction but also generated an opposite electrostatic repulsion force to SMX. This study experimentally and theoretically revealed the adhesion mechanisms of SMX and potentially other sulfonamide antibiotics in molecular level, which may contribute to the study of antibiotic environmental transportation and the development of next-generation antibiotic remediation protocols.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
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IF 7.312
Yi Wang,Hao Yang,Yvling Yang,Lijing Zhu,Zhixiang Zeng,Shuan Liu,Yiguo Li,Zhiying Liang
Oil droplets can adsorb on the surface or enter the pore channels during membrane separation , causing a decrease in water flux and increasing the number of washing and replacements, thus increasing costs. So, membrane fouling seriously limits the use of the membrane in the purification of wastewater containing oils. Generally, the underwater superoleophobic surface provides better resistance to oils, which can be fabricated by the synergistic effects of the rough structure and hydrophilic groups are required. Here, poly(vinylidene fluoride)/poly(2-hydroxyethyl methacrylate) (PVDF/PHEMA) composite membranes with the continuous sponge-like rough structure were prepared by the vapor-induced phase separation process (VIPS), and then they were furthermore co-deposited by tannic acid (TA) and N-aminoethyl piperazine propane sulfonate (AEPPS). The zwitterionic surfaces with excellent underwater anti-oil adhesion ability can efficiently separate crude oil-in-water having the flux 1056 ± 102 L m −2 h −1 bar −1 and toluene-in-water emulsions having the flux of 1593 ± 163 L m −2 h −1 bar −1 , the separation efficiency is more than 99%. Moreover, they exhibit excellent underwater anti-oil adhesion ability, excellent stability, and reversibility. Our work develops rough and porous surfaces with stable underwater superoleophobicity in an efficient way, which enables the resulting membranes to be used in the continuous purification of oily wastewater.
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BIOMACROMOLECULES
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2021
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IF 6.988
Zhao Wei,Feng F. Hong,Zhangjun Cao,Sheng-Yin Zhao,Lin Chen
Autograft is currently the gold standard in the clinical treatment of peripheral nerve injury (PNI), which, however, is limited by the availability of a donor nerve and secondary injuries. Nerve guidance conduits (NGC) provide a suitable microenvironment to promote the regeneration of injured nerves, which could be the substitutes for autografts. In this study, nerve growth factor (NGF) encapsulated chitosan nanoparticles (CSNPs) were first constructed in situ in an oxidized bacterial cellulose (OBC) conduit using the ion gel method after the introduction of a CS/NGF solution under pressure to enable a sustainable release of NGF. A novel NGF@CSNPs/OBC nanocomposite with antibacterial activity, biodegradability, and porous microstructure was successfully developed. In vitro experiments showed that the nanocomposite promoted the adhesion and proliferation of Schwann cells. When the nanocomposite was applied as NGC to repair the sciatic nerve defect of rats, a successful repair of the 10 mm nerve defect was observed after 4 weeks. At week 9, the diameter, morphology, histology, and functional recovery of the regenerated nerve was comparable to the autografts, indicating that the NGC effectively promoted the regeneration and function recovery of the nerve. In summary, the NGF@CSNPs/OBC as a novel NGC provides great potential in the treatment of PNI.
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危险品化学品经营许可证（带存储）