Distribution of Bi–MnS Inclusions Existing in 1215MS Steels: Correlation with Thermal Physical Coefficient

Jian‑bo Xie,Bei‑bei Liu,Xiang‑yu Wu,Jian‑xun Fu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.5

This work aims to comprehensively summarize the types and distribution of the isolated Bi particles and MnS inclusions inthe Bi-bearing steels, to study the precipitated behavior of sulfide, and to study the effect of Bi particles on grain sizes andthe volume thermal expansion coefficients of the steels. Results show that the average percentage of the isolated Bi particles,semi-encapsulation, complete encapsulation, back-bridge, tiny encapsulation, cavity bridge Bi–MnS inclusions in the Bibearingsteels was 16.89%, 20.49%, 3.44%, 16.89%, 31.63%, 10.66%, respectively. The average equivalent diameters of thegrains in the 0 ppm, 130 ppm, 240 ppm, 760 ppm, 1200 ppm and 2300 ppm Bi content steels were 20.88, 20.17, 19.54, 18.13,13.98 and 13.25 μm, respectively. The precipitated equilibrium mass concentration product of the MnS (w[Mn]·w[S]) wascalculated to be 1.07, and the solid fraction fS value was 0.61. At 950 °C, the volume thermal expansion coefficient change(ΔVE) in 760 ppm Bi content steel was minimum 4 × 10–10%, while at 461.6 °C the ΔVE was maximum, 0.09%, which meansthat Bi affected the volume thermal expansion of the steel strongest in this temperature range.

Disruption of ecdysis in Leptinotarsa decemlineata by knockdown of chitin deacetylase 1

Jian-Jian Wu,Li-Li Mu,Zhong-Chao Chen,Kai-Yun Fu,Wen-Chao Guo,Chao Li,Guo-Qing Li 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

Chitin deacetylases (CDAs) catalyze N-deacetylation of chitin, a crucial process for chitin modification. In the present paper, LdCDA1 was identified in Leptinotarsa decemlineata. It was copiously expressed in larval foregut, hindgut and epidermis. Just before the molt in the first, second and third larval instars, the mRNA levels of LdCDA1 were high. In the fourth (final)-instar larvae, a peak occurred 4 days after ecdysis. In vivo results revealed that LdCDA1 transcriptionally responded, positively and negatively respectively, to 20-hydroxyecdysone and juvenile hormone titers. Moreover, knockdown of LdCDA1 significantly reduced foliage consumption, lengthened developing period and prevented growth in the final instar larvae. Three distinct lethal phenotypes were noted in the LdCDA1 RNAi larvae. About 30% of the RNAi larvae became moribund and finally died; approximately 50% of deformed pupae died as pharate adults; and around 20% of LdCDA1 depleted pupae finally emerged as abnormal adults and eventually died within 1 week after emergence. Furthermore, chitin content was low and the mRNA levels of five chitin biosynthesis transcripts (LdUAP1, LdUAP2, LdChSAa, LdChSAb and LdChSB) were significantly declined in the LdCDA1 RNAi larvae. In addition, glucose, trehalose and glycogen contents were increased in the LdCDA1 depleted hypomorphs, along with highly expressed genes coding for trehalose and glycogen synthesis enzymes. The findings provide a compelling piece of evidence that CDA1 is critical for chitin deposition in L. decemlineata. Moreover, LdCDA1 may be a potential target for control of the larvae.

Enhancing Functional Expression of β-glucosidase in Pichia pastoris by Co-expressing Protein Disulfide Isomerase

Jian-hong Zhang,Dan Wu,Jian Chen,Jing Wu 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.6

The expression of heterologous proteins may exert severe stress on the host cells at different levels. Protein folding and disulfide bond formation were identified as rate-limited steps in recombinant protein secretion in yeast cells. For the production of β-glucosidase in Pichia pastoris, final β-glucosidase activity reached 1,749 U/mL after fermentation optimization in a 3 L bioreactor, while the specific activity decreased from 620to 467 U/mg, indicating a potential protein misfolding. To solve this problem, protein disulfide isomerase, a chaperone protein which may effectively regulate disulfide bond formation and protein folding, was co-expressed with β-glucosidase. In the co-expression system, a β-glucosidase production level of 2,553 U/mL was achieved and the specific activity of the enzyme reached 721 U/mg, which is 1.54 fold that of the control.

Enhancement of Polysialic Acid Yield by Reducing Initial Phosphate and Feeding Ammonia Water to Escherichia coli CCTCC M208088

Jian-Rong Wu,Jin-Long Liu,Xiao-Bei Zhan,Chi-Chung Lin,Hui Zhao 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.4

Polysialic acid (PSA) is a capsular polysaccharide obtained from aerobic fermentation with Escherichia coli. To enhance PSA production and eliminate the influence of phosphate on the PSA purification process, a lower level of initial phosphate was adopted with pH control. The resulting PSA yield reached 4.1 g/L in fed-batch fermentation with 2.5 g/L K2HPO4 and E. coli strain CCTCC M208088. In addition, an ammonia water (NH4OH) feeding strategy to control the pH at 6.4 was developed resulting in PSA production that reached as high as 5.2 g/L. NMR spectra confirmed the purified biopolymer as a α-2,8linked PSA, identical to the published NMR spectra, with a molecular weight in the range of 16 ~ 50 kDa.

Differentiating Technique: Constructing Efficient HIBE with Constant Size Ciphertext and Authorized Delegation

Jian-Wu Zheng,Jing Zhao,Xin-Ping Guan 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.8

As Hierarchical Identity Based Encryption (HIBE) system usually maps the true institutional structure of an organization or entity relationship between objects in real world, It is important that computation & communication complexity of private key, ciphertext, cryptographic computations and so on related to an entity in the hierarchy is independent to the hierarchy depth of the entity. Moreover, key escrow problem that any non-leaf entity in a hierarchical identity based cryptosystem can derive private keys for its descendants with use of its private key should be resolved, in order to prevent any entity from behaving on behalf of its descendants. In this paper, a new technique is introduced for composing a private key for each individual entity in HIBE system by differentiating between non-local identifiers and local identifiers of the identity of the entity. That we call Identifier Discrimination. With the technique, A selective identity secure HIBE system is constructed under Decisional Bilinear Diffie-Hellman (DBDH) assumption without using random oracles, where the private key and the ciphertext consist of constant number of group elements, and decryption requires only three bilinear map computations, regardless of the identity hierarchy depth. Moreover, in contrast to previous HIBE constructions, where private key for an entity can be derived by its ancestors with direct use of their private keys, key escrow problem inherent in identity based cryptosystems is resolved in our HIBE construction. Privilege of deriving private keys for an entity can be delegated to any of its ancestors through authorization by distributing specifically crafted values to the ancestor in our HIBE system, that we call Authorized Delegation.

Identification of novel rheumatoid arthritis-associated MiRNA-204-5p from plasma exosomes

Wu Long-Fei,Zhang Qin,Mo Xing-Bo,Lin Jun,Wu Yang-Lin,Lu Xin,He Pei,Wu Jian,Guo Yu-Fan,Wang Ming-Jun,Ren Wen-Yan,Deng Hong-Wen,Lei Shu-Feng,Deng Fei-Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Rheumatoid arthritis (RA) is an autoimmune disease characterized by infiltration of immune cells in the synovium. However, the crosstalk of immune cells and synovial fibroblasts is still largely unknown. Here, global miRNA screening in plasma exosomes was carried out with a custom microarray (RA patients vs. healthy controls = 9:9). A total of 14 exosomal miRNAs were abnormally expressed in the RA patients. Then, downregulated expression of exosomal miR-204-5p was confirmed in both the replication (RA patients vs. healthy controls = 30:30) and validation groups (RA patients vs. healthy controls = 56:60). Similar to the findings obtained in humans, a decreased abundance of exosomal miR-204-5p was observed in mice with collagen-induced arthritis (CIA). Furthermore, Spearman correlation analysis indicated that plasma exosomal miR-204-5p expression was inversely correlated with disease parameters of RA patients, such as rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein. In vitro, our data showed that human T lymphocytes released exosomes containing large amounts of miR-204-5p, which can be transferred into synovial fibroblasts, inhibiting cell proliferation. Overexpression of miR-204-5p in synovial fibroblasts suppressed synovial fibroblast activation by targeting genes related to cell proliferation and invasion. In vivo assays found that administration of lentiviruses expressing miR-204-5p markedly alleviated the disease progression of the mice with CIA. Collectively, this study identified a novel RA-associated plasma exosomal miRNA-204-5p that mediates the communication between immune cells and synovial fibroblasts and can be used as a potential biomarker for RA diagnosis and treatment.

Dual-pumped nondegenerate four-wave mixing in semiconductor laser with a built-in external cavity

Wu, Jian-Wei,Qiu, Qi,Hyub Won, Yong IOP 2017 Journal of optics Vol.19 No.4

<P>In this paper, a semiconductor laser system consisting of a conventional multimode Fabry–Pérot laser diode with a built-in external cavity is presented and demonstrated. More than two resonance modes, whose peak levels are significantly higher than other residual modes, are simultaneously supported and output by adjusting the bias current and operating temperature of the active region. Based on this device, dual-pumped nondegenerate four-wave mixing—in which two pump waves and a single signal wave are simultaneously fed into the laser, and the injection power and wavelength of the injected pump and signal waves are changed—is observed and discussed thoroughly. The results show that while the wavelengths of pump wave A and signal wave S are kept constant, the other pump wave B jumps from about 1535 nm to 1578 nm, generating conversion signals with changed wavelengths. The achieved conversion bandwidth between the primary signal and the converted signal waves is broadly tunable in the range of several terahertz frequencies. Both the conversion efficiency and optical signal-to-noise ratio of the newly generated conversion signals are adopted to evaluate the performance of the proposed four-wave mixing process, and are strongly dependent on the wavelength and power of the injected waves. Here, the attained maximum conversion efficiency and optical signal-to-noise ratio are close to −22 dB and 15 dB, respectively.</P>

Study on the Effect of nitrogen on Beijerinckia indica for PS-7 Production by Flux Analysis

Jian-Rong Wu,Jin-Woo Lee,Sung-Koo Kim 한국생명과학회 2004 한국생명과학회 심포지움 Vol.43 No.-

Inhibitory Effect of Curcumin on Invasion of Skin Squamous Cell Carcinoma A431 Cells

Wu, Jian,Lu, Wen-Ying,Cui, Lei-Lei Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Objective: To investigate the regulatory effect of curcumin on expression of signal transducer and activator of transcription 3 (STAT3) in skin squamous cell carcinoma tissues as well as possible mechanisms of curcumin in prevention and treatment of skin squamous cell carcinoma. Materials and Methods: Highly invasive A431 cells were treated with curcumin at various doses .The cytotoxic effects of treatment with 5, 10, 15, 20, 25, 30, 35, 40 and 50 umol/L curcumin for 24, 48 and 72 hours on A431 cells were measured by MTT assay. The invasion capacity of cells treated with 5, 10 and 15 umol/L curcumin was measured by Transwell test, while adhesive ability was assessed by cell adhesion assay. The effects of 5,10 and 15 umol/L curcumin on expression levels of STAT3 were determined by Western blotting and on transcription levels of STAT3 mRNA by RT-PCR. Results: Treatment with curcumin at a doses of more than 15 umol/L for more than 24 hour inhibited the growth of A431 cells in a time-and dose-dependent fashion (p<0.001). The doses of 15 umol/L and less for 24 hours showed no significant cytotoxic effects on the cells, survival rates being more than 85%.The invasion and adhesive abilities decreased gradually with the increasing curcumin concentration, 15 umol/L exerting the strongest inhibitory effects (p<0.05). Curcumin showed significant dose-dependent inhibitory effects on the transcription level of STAT3 mRNA (p<0.05). Conclusions: Curcumin may reduce the invasive ability of A431 cells by inhibiting the activation of STAT3 signal pathway and expression of STAT3 as a target gene in the pathway.

On Resolving Key Escrow Problem in HIBE and HIBS

Jian-Wu Zheng,Jing Zhao,Xin-Ping Guan 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.6

In traditional hierarchical identity based cryptosystems (HIBC), non-leaf entities as level PKGs are usually capable of deriving private keys for their descendants with use of their private keys, non-leaf entities can therefore act (decrypt or sign) on the behalf of their arbitrary descendants. This is called key escrow problem of HIBC. In order to resolve key escrow problem, a new technique – Identifier Discrimination is proposed in this paper for composing private keys for entities in hierarchy. With the technique, an identity selective secure HIBE scheme is constructed under Decisional Bilinear Diffie- Helleman (DBDH) assumption in standard security model, in which any identity is incapable of deriving private keys for any of its descendants with use of its private key, and the privilege of generating private keys for each individual descendant is delegated by the root PKG through authorization, that we call Authorization Delegation. Moreover, a new hierarchical identity based signature (HIBS) scheme is constructed from our HIBE construction, by applying Naor transformation of an identity-based signature (IBS) out of an IBE. Because of the inability of deriving its descendants’ private keys with use its private key, an entity therefore cannot sign messages on behalf of any of its descendants, thus guaranteeing that authenticity and non-repudiation properties are achieved in our HIBS system.