Surface Modification of Colloidal Silica Nanoparticles: Controlling the size and Grafting Process

Wentao He,Danhua Wu,Juan Li,Kai Zhang,Yushu Xiang,Lijuan Long,Shuhao Qin,Jie Yu,Qin Zhang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

Surface modification of colloidal silica nanoparticles without disrupting the electric double layer of nanoparticles is a major challenge. In the work, silane was employed to modify colloidal silica nanoparticles without inducing bridge flocculation obviously. The effect of pH value of the silica sol, the amount of silane in feed, and reaction temperature on the graft amount and the final size of modified particles was investigated. The increased weight loss by TG and the appearance of T2 and T3 except for Q2 and Q3 signals by CP/MAS 29Si NMR of the modified samples verified the successful grafting of silane. The graft amount reached 0.57 mmol/ g, which was slightly lower than theory value, and the particle size remained nearly the same as unmodified particles for acidic silica sol at the optimum condition. For alkaline silica sol after modification, aggregates composed of several nanoparticles connected together with silane moleculars as the bridge appeared.

piRNA-1742 promotes renal cell carcinoma malignancy by regulating USP8 stability through binding to hnRNPU and thereby inhibiting MUC12 ubiquitination

Zhang Wentao,Zheng Zongtai,Wang Keyi,Mao Weipu,Li Xue,Wang Guangchun,Zhang Yuanyuan,Huang Jianhua,Zhang Ning,Wu Pengfei,Liu Ji,Zhang Haimin,Che Jianping,Peng Bo,Zheng Junhua,Li Wei,Yao Xudong 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Accumulating studies have confirmed that PIWI-interacting RNAs (piRNAs) are considered epigenetic effectors in cancer. We performed piRNA microarray expression analysis on renal cell carcinoma (RCC) tumor tissues and paired normal tissues and performed a series of in vivo and in vitro experiments to explore piRNAs associated with RCC progression and investigate their functional mechanisms. We found that piR-1742 was highly expressed in RCC tumors and that patients with high piR-1742 expression had a poor prognosis. Inhibition of piR-1742 significantly reduced tumor growth in RCC xenograft and organoid models. Mechanistically, piRNA-1742 regulates the stability of USP8 mRNA by binding directly to hnRNPU, which acts as a deubiquitinating enzyme that inhibits the ubiquitination of MUC12 and promotes the development of malignant RCC. Subsequently, nanotherapeutic systems loaded with piRNA-1742 inhibitors were found to effectively inhibit the metastasis and growth of RCC in vivo. Therefore, this study highlights the functional importance of piRNA-related ubiquitination in RCC and demonstrates the development of a related nanotherapeutic system, possibly contributing to the development of therapeutic approaches for RCC.

Surface Modification of Colloidal Silica Nanoparticles: Controlling the size and Grafting Process

He, Wentao,Wu, Danhua,Li, Juan,Zhang, Kai,Xiang, Yushu,Long, Lijuan,Qin, Shuhao,Yu, Jie,Zhang, Qin Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

Surface modification of colloidal silica nanoparticles without disrupting the electric double layer of nanoparticles is a major challenge. In the work, silane was employed to modify colloidal silica nanoparticles without inducing bridge flocculation obviously. The effect of pH value of the silica sol, the amount of silane in feed, and reaction temperature on the graft amount and the final size of modified particles was investigated. The increased weight loss by TG and the appearance of $T_2$ and $T_3$ except for $Q_2$ and $Q_3$ signals by CP/MAS $^{29}Si$ NMR of the modified samples verified the successful grafting of silane. The graft amount reached 0.57 mmol/g, which was slightly lower than theory value, and the particle size remained nearly the same as unmodified particles for acidic silica sol at the optimum condition. For alkaline silica sol after modification, aggregates composed of several nanoparticles connected together with silane moleculars as the bridge appeared.

Study on numerical methods for transient flow induced by speed-changing impeller of fluid machinery

Dazhuan Wu,Tao Chen,Youbo Sun,Wentao Cheng,Leqin Wang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.6

In order to establish a reliable numerical method for solving the transient rotating flow induced by a speed-changing impeller, two numerical methods based on finite volume method (FVM) were presented and analyzed in this study. Two-dimensional numerical simulations of incompressible transient unsteady flow induced by an impeller during starting process were carried out respectively by using DM and DSR methods. The accuracy and adaptability of the two methods were evaluated by comprehensively comparing the calculation results. Moreover, an intensive study on the application of DSR method was conducted subsequently. The results showed that transient flow structure evolution and transient characteristics of the starting impeller are obviously affected by the starting process. The transient flow can be captured by both two methods, and the DSR method shows a higher computational efficiency. As an application example, the starting process of a mixed-flow pump was simulated by using DSR method. The calculation results were analyzed by comparing with the experiment data.

Mechanical Response of Barricade to Coupled THMC Behavior of Cemented Paste Backfill

Di Wu,Wentao Hou,Shuai Liu,Huaibin Liu 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.5

Cemented paste backfill (CPB), which is prepared by mixing tailings, binder and water, is widely used in underground mines for waste management and ground control. Since the CPB is delivered into mined-out areas in the form of fluid, a barricade needs to be constructed for retaining it during the process of its filling and hardening. Therefore, the barricade should have enough mechanical stability to ensure the safety of the backfill operation. The behavior of CPB, which is influenced by the thermal, hydraulic, mechanical and chemical (THMC) coupled processes, acts on the barricade and thus affects its mechanical response. In the present study, a numerical model is developed to predict and analyze the barricade mechanical performance in response to the coupled THMC behavior of CPB. The validity of the proposed model is then verified against two field case studies. Acceptable agreement between the model prediction results and in situ monitoring data proves the capability of the developed model in simulating the barricade pressure and displacement. Then, the validated model is used to investigate the effect of filling strategy on the barricade displacement. The obtained results can contribute to a better understanding of the barricade performance under various backfill conditions.

Convective Heat Transfer Coeicient Model Under Nanoluid Minimum Quantity Lubrication Coupled with Cryogenic Air Grinding Ti–6Al–4V

Jianchao Zhang,Wentao Wu,Changhe Li,Min Yang,Yanbin Zhang,Dongzhou Jia,Yali Hou,Runze Li,Huajun Cao,Hafiz Muhammad Ali 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.4

Under the threat of serious environmental pollution and resource waste, sustainable development and green manufacturing have gradually become a new development trend. A new environmentally sustainable approach, namely, cryogenic air nanofluid minimum quantity lubrication (CNMQL), is proposed considering the unfavorable lubricating characteristic of cryogenic air (CA) and the deficient cooling performance of minimum quantity lubrication (MQL). However, the heat transfer mechanism of vortex tube cold air fraction by CNMQL remains unclear. The cold air fraction of vortex tubes influences the boiling heat transfer state and cooling heat transfer performance of nanofluids during the grinding process. Thus, a convective heat transfer coefficient model was established based on the theory of boiling heat transfer and conduction, and the numerical simulation of finite difference and temperature field in the grinding zone under different vortex tube cold air fractions was conducted. Simulation results demonstrated that the highest temperature initially declines and then rises with increasing cold air fraction. Afterward, this temperature reaches the lowest peak (192.7 °C) when the cold air fraction is 0.35. Experimental verification was conducted with Ti–6Al–4V to verify the convective heat transfer coefficient model. The results concluded that the low specific grinding energy (66.03 J/mm 3 ), high viscosity (267.8 cP), and large contact angle (54.01°) of nanofluids were obtained when the cold air fraction was 0.35. Meanwhile, the lowest temperature of the grinding zone was obtained (183.9 °C). Furthermore, the experimental results were consistent with the theoretical analysis, thereby verifying the reliability of the simulation model.

Description of Corynebacterium poyangense sp. nov., isolated from the feces of the greater white-fronted geese (Anser albifrons)

Liu Qian,Fan Guoying,Wu Kui,Bai Xiangning,Yang Xi,Song Wentao,Chen Shengen,Xiong Yanwen,Chen Haiying 한국미생물학회 2022 The journal of microbiology Vol.60 No.7

Two novel Gram-positive, non-spore-forming, facultatively anaerobic, non-motile, and short rods to coccoid strains were isolated from the feces of the greater white-fronted geese (Anser albifrons) at Poyang Lake. The 16S rRNA gene sequences of strains 4H37-19T and 3HC-13 shared highest identity to that of Corynebacterium uropygiale Iso10T (97.8%). Phylogenetic and phylogenomic analyses indicated that strains 4H37-19T and 3HC-13 formed an independent clade within genus Corynebacterium and clustered with Corynebacterium uropygiale Iso10T. The average nucleotide identity and digital DNA-DNA hybridization value between strains 4H37-19T and 3HC-13 and members within genus Corynebacterium were all below 95% and 70%, respectively. The genomic G + C content of strains 4H37-19T and 3HC-13 was 52.5%. Diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylinositol (PI), phosphatidylcholine, and phosphatidyl inositol mannosides (PIM) were the major polar lipids, with C18:1ω9c, C16:0, and C18:0 as the major fatty acids, and MK-8 (H4), MK-8(H2), and MK-9(H2) as the predominant respiratory quinones. The major whole cell sugar was arabinose, and the cell wall included mycolic acids. The cell wall peptidoglycan contained meso-diaminopimelic acid (meso-DAP). The polyphasic taxonomic data shows that these two strains represent a novel species of the genus Corynebacterium, for which the name Corynebacterium poyangense sp. nov. is proposed. The type strain of Corynebacterium poyangense is 4H37-19T (=GDMCC 1.1738T = KACC 21671T).

Affinity-Purification of Fibrinogenase with High Proteolytic Activity from Agkistrodon halys (Chinese) Venom

Ma, Biao,Zhan, Ying,Wu, Dan,Jia, Jianping,Xu, Wentao,Luo, Yunbo 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.9

To purify and characterize the fibrinogenase with high proteolytic activity from Agkistrodon halys (Chinese) Venom. Monoclonal antibodies against fibrinogenase were prepared and a novel affinity chromatography equipped with a monoclonal antibody against fibrinogenase was developed and applied for the purification of fibrinogenases. The purified fibrinogenase was identified by fibrinolytic activity assay, and antithrombosis activity assay. HPLC chromatography and SDS-PAGE analysis demonstrated the uniformity and purity of the purified fibrinogenase. In comparison with a conventional A-50 chromatography method, affinity-purified fibrinogenase showed higher activity ($3631\;U\;mg^{-1}$ vs $501\;U\;mg^{-1}$). In addition, the physiological activity of the fibrinogenase both in vitro and ex vivo showed the purified fibrinogenase can specifically degrade $\beta$-, $\gamma$-fibrinogen and has a high anti-thrombotic activity. In conclusion, the purified fibrinogenase by affinity column were shown to be homogeneous and showed a high and specific proteolytic activity against $\beta$-chains of fibrinogen molecules and antithrombosis activity.

Association between perioperative glucocorticoids and cancer metastasis and survival in patients undergoing radical cystectomy for urothelial carcinoma of the bladder: A single-center retrospective study

Shiyu Mao,Yuan Wu,Ruiliang Wang,Yadong Guo,Jing Yuan,Wentao Zhang,Junfeng Zhang,Yang Yan,Xudong Yao 대한비뇨의학회 2020 Investigative and Clinical Urology Vol.61 No.4

Purpose: Perioperative glucocorticoids have the potential to increase the risk of tumor metastasis. However, the relationship between perioperative glucocorticoids and oncologic outcomes remains controversial. The present study was undertaken to evaluate the association of perioperative glucocorticoids with clinicopathologic outcomes following radical cystectomy (RC). Materials and Methods: We screened and included 185 patients who underwent radical surgery for bladder cancer in our center between 2009 and 2018. The Kaplan–Meier method was applied, and a log-rank test was used to estimate differences in metastasis-free survival (MFS) and overall survival (OS) between the groups. Multivariate Cox proportional hazards regression models were used to analyze any association of glucocorticoids with clinical outcomes. Results: A total of 76 (41.1%) patients received perioperative glucocorticoids. Median postoperative follow-up was 2.0 years. Kaplan–Meier survival curve indicated that the glucocorticoids group was significantly associated with increased distant MFS (p=0.008) but not with OS. In the multivariate analysis, no significant differences were observed for MFS between the groups. Interestingly, when the variable of blood transfusion was excluded from the multivariate analysis model, we found that patients receiving glucocorticoids were independently associated with worse MFS (hazard ratio, 1.790; p=0.030). Furthermore, the partial correlation analysis showed a significant positive correlation between perioperative glucocorticoids and blood transfusion (r=0.604, p<0.001). In the nontransfusion subgroup, propensity score matching showed that patients receiving glucocorticoids had a higher risk of distant metastasis. Conclusions: Perioperative glucocorticoids were associated with a higher rate of distant metastasis in patients undergoing RC for bladder cancer.

3D numerical simulation study of Brazilian splitting in calcite vein-bearing shale based on CT scans

Wenli Lei,Zhonghu Wu,Huailei Song,Hengtao Cui,Wentao Wang,Motian Tang 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.6

Shale affects reservoir fracture sprouting and expansion during fracture modification. The aim of this study was to investigate the influence of calcite veins with distinct flaw inclinations on the stretch strength and destruction pattern of shale. In the text, we reconstructed 3D numericalmodels of shale with seven groups of different calcite vein inclinations using CT scanning of shale specimens from the Niutitang Formation in the Feng’gang No. 3 block in the northern part of Guizhou Province and performed Brazilian splitting simulation tests. Research shows the effect of the calcite vein angle on the ultimate tensile strength and damage mode of shale, and the damage modes mainly include tensile damage, tensile-shear damage, pressure-shear damage and compression damage. Calcite veins have a significant structural effect on the tensile strength of shale. Due to the change in calcite vein inclination, the stress decomposition on the specimen acts on the positive and shear stresses along the calcite vein direction changes significantly, which results in a large difference in the splitting stress between calcite veins and shale matrix when destabilization damage occurs. The research efforts have a key impact on the crack mechanism of shale hydraulic fracturing, fracture expansion law and the improvement of shale gas recovery rate.