Synthesis and Sol-Gel Transition of Novel Temperature Responsive ABA Triblock-Graft Copolymers Based on PCL and PEG Analogues

Qinqin Wang,Shouxin Liu,Weijuan Sheng,Naer Guang,Xuan Li 한국고분자학회 2015 Macromolecular Research Vol.23 No.7

Novel hydrophilic, temperature responsive, and biodegradable ABA triblock-graft copolymers, [poly(ε- caprolactone)-g-poly(2-(2-methoxyethoxy) ethyl methacrylate-co-oligo(ethylene glycol) methacrylate)]-b-poly(ethylene glycol)-b-[poly(-caprolactone)-g-poly(2-(2-methoxyethoxy) ethyl methacrylate-co-oligo(ethylene glycol) methacrylate)] ([PCL-g-P(MEO2MA-co-OEGMA)]-b-PEG-b-[PCL-g-P(MEO2MA-co-OEGMA)]) (tBGs), were synthesized via a combination of ring-opening polymerization (ROP) of ε-caprolactone (εCL) and α-chloro-ε-caprolactone (αClεCL) in the presence of PEG and atom transfer radical polymerization (ATRP) of MEO2MA and OEGMA. Temperature responsive P(MEO2MA-co-OEGMA) graft chains on the hydrophobic PCL block of PCL-b-PEG-b-PCL not only improved the solubility of PCL-b-PEG-b-PCL in water, but also endowed it with temperature sensitivity. The synthesized temperature responsive triblock-graft copolymers formed well-defined core-shell micelles as the temperature was above their LCST (ca. 35 oC), with hydrophilic PEG block as shell, P(MEO2MA-co-OEGMA) graft chains on the PCL block and hydrophobic PCL block aggregates as core. The micellization induced by temperature for the tBGs in aqueous solutions had been investigated by transmittance measurement, laser particle size measurement, 1H NMR in D2O, DLS and TEM. For a given tBG5 aqueous solution (30 wt%), a weak hydrogel was available at 35 oC, and its sol-gel transition temperature gradually decreased with increasing concentration. In addition, the tBG5 hydrogels loaded with anethole were used for hydrophobic drug release, and in vitro the sustained release of anethole from the tBG5 hydrogels was examined, which is a significant for anethole for their biomedical applications.

Recent advances in MXenes supported semiconductors based photocatalysts: Properties, synthesis and photocatalytic applications

Cheera Prasad,Xiaofei Yang,Qinqin Liu,Hua Tang,Aluru Rammohan,Syed Zulfiqar,Grigory V. Zyryanov,Sufaid Shah 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.85 No.-

The families of MAX phases and their derivatives MXenes are constantly increasing in terms of bothcomposition and crystalline mixtures. In the last three years, numerous advances were accomplishedthat improved the preparation of new MAX phases with prearranged double transition metals and, as aresult, the production of novel MXenes with a high structural complexity and chemical multiplicity,infrequently observed in other families of two-dimensional samples. In this evaluation, hybrids ofMXenes and semiconductors are efficient photocatalysts, because of their specific interface character-istics and Schottky heterojunction is capable of giving accelerated charge separation and a lowerSchottky barrier for photocatalytic applications. The latest advances were proved that the MXenessupported semiconductors based photocatalysts can be expected as the most advantaged andencouraged novel photocatalysts in the photocatalytic and photoelectrochemical applications. Besides,we have explained significant developments in efficient MXenes supported semiconductors basednanocomposites, including the frequent synthesis strategies and progress mechanisms, in addition totheir new applications including, photodegradation of dyes, CO2 conversion, photocatalytic andphotoelectrochemical water splitting reaction applications. The review was completed with a shortpresentation of future challenges and prospects in the progress of MXenes supported semiconductorsbased photocatalysts. It is also believed that this review will encourage further exploration and willinaugurate new promising to increase new MXenes supported semiconductors based photocatalystswith new and inspiring applications.

The impacts of LPCVD wrap-around on the performance of n-type tunnel oxide passivated contact c-Si solar cell

Zhou Ying,Tao Ke,Liu Aimin,Rui Jia,Bao Jianhui,Sun Yufeng,Yang Sanchuan,Wang Qinqin,Zhang Qiang,Yang Songbo,Cao Yujia,Qu Hui 한국물리학회 2020 Current Applied Physics Vol.20 No.7

In this paper, Tunnel Oxide Passivated Contact (TOPCon) silicon solar cells with the industrial area (244.32 cm2) are fabricated on N-type silicon substrates. Both the ultra-thin tunnel oxide layer and phosphorus doped polycrystalline silicon (polysilicon) thin film are prepared by the LPCVD system. The wrap-around of polysilicon is observed on the surface of borosilicate glass (BSG). The polysilicon wrap-around can form a leakage current path, thus degrades the shunt resistance of solar cells, and leads to the degradation of solar cell efficiency. Different methods are adopted to treat the polysilicon wrap-around and improve shunt resistance of solar cells. The experimental results indicate that a chemical etching method can effectively solve the problem of polysilicon wrap-around and improve the performance of solar cells. Finally, a conversion efficiency of 22.81% has been achieved by our bifacial TOPCon solar cells, with Voc of 702.6 mV, Jsc of 39.78 mA/cm2 and FF of 81.62%.

A comparison of concurrent chemoradiotherapy and radical surgery in patients with specific locally advanced cervical cancer (stage IB3, IIA2, IIICr): trial protocol for a randomized controlled study (C-CRAL trial)

Junjun Qiu,Shugen Sun,Qinqin Liu,Jie Fu,Yan Huang,Keqin Hua 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.5

Objective: Genetic high-risk assessment combines hereditary breast, ovarian and pancreatic cancer into one syndrome. However, there is a lack of data for comparing the germline mutational spectrum of the cancer predisposing genes between these three cancers. Methods: Patients who met the criteria of the hereditary breast, ovarian and pancreatic cancer were enrolled and received multi-gene sequencing. Results: We enrolled 730 probands: 418 developed breast cancer, 185 had ovarian cancer, and 145 had pancreatic cancer. Out of the 18 patients who had two types of cancer, 16 had breast and ovarian cancer and 2 had breast and pancreatic cancer. A total of 167 (22.9%) patients had 170 mutations. Mutation frequency in breast, ovarian and pancreatic cancer was 22.3%, 33.5% and 17.2%, respectively. The mutation rate was significantly higher in patients with double cancers than those with a single cancer (p<0.001). BRCA1 and BRCA2 were the most dominant genes associated with hereditary breast and ovarian cancer, whereas ATM was the most prevalent gene related to hereditary pancreatic cancer. Genes of hereditary colon cancer such as lynch syndrome were presented in a part of patients with pancreatic or ovarian cancer but seldom in those with breast cancer. Families with a history of both ovarian and breast cancer were associated with a higher mutation rate than those with other histories. Conclusion: The mutation spectrum varies across the three cancer types and family histories. Our analysis provides guidance for physicians, counsellors, and counselees on the offer and uptake of genetic counseling.

Trophic strategy of diverse methanogens across a river-to-sea gradient

Bingchen Wang,Fanghua Liu,Shiling Zheng,Qinqin Hao 한국미생물학회 2019 The journal of microbiology Vol.57 No.6

Methanogens are an important biogenic source of methane, especially in estuarine waters across a river-to-sea gradient. However, the diversity and trophic strategy of methanogens in this gradient are not clear. In this study, the diversity and trophic strategy of methanogens in sediments across the Yellow River (YR) to the Bohai Sea (BS) gradient were investigated by high-throughput sequencing based on the 16S rRNA gene. The results showed that the diversity of methanogens in sediments varied from multitrophic communities in YR samples to specific methylotrophic communities in BS samples. The methanogenic community in YR samples was dominated by Methanosarcina, while that of BS samples was dominated by methylotrophic Methanococcoides. The distinct methanogens suggested that the methanogenic community of BS sediments did not originate from YR sediment input. High-throughput sequencing of the mcrA gene revealed that active Methanococcoides dominated in the BS enrichment cultures with trimethylamine as the substrate, and methylotrophic Methanolobus dominated in the YR enrichment cultures, as detected to a limited amount in in situ sediment samples. Methanosarcina were also detected in this gradient sample. Furthermore, the same species of Methanosarcina mazei, which was widely distributed, was isolated from the area across a river-to-sea gradient by the culture-dependent method. In summary, our results showed that a distribution of diverse methanogens across a river-to-sea gradient may shed light on adaption strategies and survival mechanisms in methanogens.

Wavelet packet transform and improved complete ensemble empirical mode decomposition with adaptive noise based power quality disturbance detection

Yu Mei,Yajing Wang,Xiangke Zhang,Shiqi Liu,Qinqin Wei,Zhenhai Dou 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.8

Given the low accuracy of power quality disturbance (PQD) detection, a PQD detection method based on the wavelet packet transform (WPT) and improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) is proposed in this paper. First, the wavelet packet transform is used to preprocess the signal to suppress noise interference. Then, ICEEMDAN technology is adopted to calculate the local mean value by adding adaptive noise. In addition, different intrinsic mode functions (IMFs) are obtained through residual subtraction. Furthermore, the effective IMFs are calculated by the permutation entropy method to reduce false modal components and to suppress residual noise. Finally, a Hilbert transform (HT) is performed to extract the detection signal parameters. The obtained results demonstrate that this method can improve the detection accuracy and PQD speed, which results in a strong anti-noise capability.

Progress and challenges in full spectrum photocatalysts: Mechanism and photocatalytic applications

Jinghang Xu,Jun Shen,Haopeng Jiang,Xiaohui Yu,Waqar Ahmad Qureshi,Chanez Maouche,Jingsong Gao,Juan Yang,Qinqin Liu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.119 No.-

How to efficiently convert solar energy into storable chemical energy has always been an urgent problemin the field of semiconductor-based photocatalysis. Broaden the light-absorption range of photocatalystsis an important strategy to improve the efficiency of solar energy conversion. This paper focused on therecent reported photocatalytic systems that can make use of full spectrum solar energy, and comparativelyexpounded their design, fabrication methods, mechanism and applications (H2 generation, CO2reduction, chemical synthesis and sterilization). Emphases were given to the specific mechanisms forfull-spectrum absorption in various photocatalysts, including semiconductors with narrow bandgaps,defective semiconductors, plasmonic nano-materials. The outlook was put forward that the future ofphotocatalytic research is infinite, and ongoing efforts should be devoted on the utilization of infraredlightpart in solar spectrum.

Construction of a Transposon-mediated Baculovirus Vector Hanpvid and a New Cell Line for Expressing Barnase

Qin, Qin,Liu, Ying-Le,Zhu, Ying,Li, Shun-Yi,Qi, Yi-Peng Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.1

In this study we developed the transposon-mediated shuttle vector 'Hanpvid', which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AM1). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AM1-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM1 and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages ($LD_{50}$) and the lethal time(s) ($LT_{50}$) of rHa-Bar were reduced by 20% and 30%, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.

Construction of a Transposon-mediated Baculovirus Vector Hanpvid and a New Cell Line for Expressing Barnase

( Qin Qin ),( Ying Le Liu ),( Ying Zhu ),( Shun Yi Li ),( Yi Peng Qi ) 생화학분자생물학회 2005 BMB Reports Vol.38 No.1

In this study we developed the transposon-mediated shuttle vector `Hanpvid`, which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AMU). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AMl-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM! and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages (LD_(50)) and the lethal time(s) (LT_(50)) of rHa-Bar were reduced by 20% and 30%, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.