An Analysis on the History and Prospect of the Pashtunistan Issue

Zhang Hao,Zhang Yifan 아시아사회과학학회 2020 Jornal of Asia Social Science Vol.1 No.2

The issue of Pashtunistan has long plagued the relationship between Afghanistan and Pakistan. The Pashtun issue originated from the delineation of the Durand Line between Afghanistan and British India. As a result, for a long time there was no clear border demarcation between Afghanistan and British India. The Pashtun inhabited areas include the western part of Pakistan today and parts of southern and eastern Afghanistan, just scattered on the east and west sides of the original Durand Line. The two countries’ cognition of the Durand Line and the identification of the Pashtun ethnic group across the border have laid a hidden danger for the formation, development and realities of the Pashtun issue in the future. Since 1980s, the controversy has been fading. In 2020, with the complete withdrawal of the US armed forces from Afghanistan and the end of the 19-year war in Afghanistan, will the issue of Pashtunistan between Pakistan and Afghanistan resurface? In the post-Afghanistan war era, the trend, prospect and risks of this topic deserve further discussion and study.

Effect of Blade Profile on the Performance of a Centrifugal Fan with Different Velocity Distribution Functions

Yifan Zhang,Hua-Shu Dou 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.3

The velocity distribution method is a way to design the blade profile according to the average relative velocity in the impeller passage. Present research is aimed to investigate the effect of blade profile on the performance of a centrifugal fan with different velocity distribution functions through numerical simulations. The results show that compared with common arc blade, the centrifugal fan with new blade profile designed by velocity distribution method gets a higher efficiency, the relative velocity distribution along impeller passages of the new model is more uniform, and the boundary layer separation is delayed than that in the original model.

A study on sliding surface design

Zhang, Yifan.,Lee, Sanghyuk Convergence Society for SMB 2014 융합정보논문지 Vol.4 No.2

비선형시스템에 대한 슬라이딩 모드제어 기법에 대한 연구를 수행하였다. 비선형 시스템의 파라미터가 제어성능과 간인성에 대한 관계를 구명하였다. 제어성능을 파악하기 위하여 역진자 시스템에적용하여 보았고, 다른 초기값, 슬라이딩 표면 그리고 입력값의 변화를 통하여 비교결과를 얻었다. 제어값은 제한적이었으며 슬라이딩 표면 역시 예외없이 제한폭을 나타냈다. 채터링 현상은 피할수 없이 존재하였으며, 이를 극복하기 위하여 수정된 불연속 제어기를 사용하여 현상을 감소시켰다. Sliding mode design and analysis for nonlinear system was carried out. A designer will determine the parameters to know about the performance and robustness of the system dynamics. To investigate the characteristics of sliding mode control, an inverted pendulum model is applied by the sliding mode control and the state concerned is output. Comparison is made by evaluating different initial conditions, sliding numerical components for sliding surface, and input gain, the dynamic of output will be investigated to conclude the generality. Control approaches have their limitations and sliding mode control is no exception. The chattering problem is its main negative effect to overcome. This effect is displayed and in this project chattering problem is suppressed by a modified discontinuous controller.

Three-dimensional Printed Mg-Doped β-TCP Bone Tissue Engineering Scaffolds: Effects of Magnesium Ion Concentration on Osteogenesis and Angiogenesis In Vitro

Yifan Gu,Jing Zhang,Xinzhi Zhang,Guiping Liang,Tao Xu,Wei Niu 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.4

BACKGROUND: Three-dimensional (3D) printed bone tissue engineering scaffolds have been widely used in research and clinical applications. b-TCP is a biomaterial commonly used in bone tissue engineering to treat bone defects, and its multifunctionality can be achieved by co-doping different metal ions. Magnesium doping in biomaterials has been shown to alter physicochemical properties of cells and enhance osteogenesis. METHODS: A series of Mg-doped TCP scaffolds were manufactured by using cryogenic 3D printing technology and sintering. The characteristics of the porous scaffolds, such as microstructure, chemical composition, mechanical properties, apparent porosity, etc., were examined. To further study the role of magnesium ions in simultaneously inducing osteogenesis and angiogenesis, human bone marrow mesenchymal stem cells (hBMSCs) and human umblical vein endothelial cells (HUVECs) were cultured in scaffold extracts to investigate cell proliferation, viability, and expression of osteogenic and angiogenic genes. RESULTS: The results showed that Mg-doped TCP scaffolds have the advantages of precise design, interconnected porous structure, and similar compressive strength to natural cancellous bone. hBMSCs and HUVECs exhibit high proliferation rate, cell morphology and viability in a certain amount of Mg2?. In addition, this concentration of magnesium can also increase the expression levels of osteogenic and angiogenic biomarkers. CONCLUSION: A certain concentration of magnesium ions plays an important role in new bone regeneration and reconstruction. It can be used as a simple and effective method to enhance the osteogenesis and angiogenesis of bioceramic scaffolds, and support the development of biomaterials and bone tissue engineering scaffolds.

On the End and Core of Chinese Traditional Calligraphy Art

Zhang Yifan 국제문화기술진흥원 2023 International Journal of Advanced Culture Technolo Vol.11 No.2

The Chinese calligraphy art, which still adheres to tradition, has fallen into the formalism deeper and deeper. The majority of studies on calligraphy still focus on the formal beauty and neglect the core spirit hidden behind the calligraphy art. The calligraphy art is an art defined by words. This definition is not only reflected in the form of the characters but also, and more importantly, in the meaning of the characters. It is not a form of writing, but a writing of lives, wills and feelings, a writing of the experience of daily life, and an improvised poetic writing. With the advent of the age of artificial intelligence, the Chinese traditional calligraphy art, which still adheres to the "supremacy of the brush and ink", has shown a sense of dystopia, and its end is inevitable. Only by truly understanding the core of the calligraphy art, by integrating it with contemporary daily life, and by focusing on the communication of ideas in calligraphy, will it be possible to obtain a new life.

Stabilization of dispersed CuPd bimetallic alloy nanoparticles on ZIF-8 for photoreduction of Cr(VI) in aqueous solution

Zhang, Yifan,Park, Soo-Jin Elsevier 2019 Chemical Engineering Journal Vol. No.

<P><B>Abstract</B></P> <P>Nowadays, the Chromium (Cr(VI)) pollution is regarded as a serious threat to both the human health and environment. Therefore, developing an efficient catalyst to remove this pollution is an urgent task. As we know, photocatalytic degradation performance of Cr(VI) is severely hampered owing to its highly recombination efficiency of electrons and holes and lower adsorption activity. In this paper, bimetallic alloy nanoparticles decorated on ZIF-8 were synthesized using a sol-gel method for the photoreduction of Cr(VI) in aqueous solution. The CuPd@ZIF-8 catalyst was characterized in terms of specific surface area, surface morphology, and optical response using X-ray diffraction (XRD) spectrum, Raman spectrum, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), specific surface area and UV–vis diffuse reflectance (DRS) spectrum. The as-obtained CuPd@ZIF-8 catalyst exhibited excellent photoreduction activity for the reduction of Cr (VI), compared to that of pristine ZIF-8 nanoparticles. Furthermore, the CuPd@ZIF-8 catalyst containing 5 wt% CuPd bimetallic nanoparticles showed the highest photocatalytic activity, where 89% reduction of Cr(VI) (20 ppm) reduction was achieved within 60 min. The as prepared CuPd@ZIF-8 catalyst provided a high specific surface area and charge transfer rate, which impeded the recombination of the generated electrons and holes. Moreover, the stability of the CuPd@ZIF-8 catalyst was tested and photocatalytic activity was maintained at ˃90% after four cycles. In addition, the proposed mechanism is explained thoroughly.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel ZIF-8/CuPd bimetallic photocatalyst were first prepared. </LI> <LI> The recombination of photo-induced electron-hole pairs had been impeded. </LI> <LI> ZIF-8/CuPd catalyst with 5 wt% of CuPd bimetallic nanoparticles displays the highest photocatalytic efficiency. </LI> <LI> The mechanism of the enhanced photocatalytic performance were discussed in detail. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A new method of phenol degradation by microarc plasma electrolysis

Yifan Zhang,Xiaoyue Jin,Jiahao Yu,Guijun Liu,Ying Wang,Wenbin Xue 한국표면공학회 2017 한국표면공학회 학술발표회 초록집 Vol.2017 No.11

Effects of carboxylesterase gene silence on wheat aphid Sitobion avenae (Fabricius)

Yifan Zhang,Fei Deng,Yongliang Fan,Zhangwu Zhao 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.2

Multifunctional carboxylesterase (CarE) has been found in all animals, plants and microbes, and belongs to a superfamily enzyme of serine hydrolase involved in detoxification, allelochemical tolerance and some specific hormone or pheromone metabolism. Insects usually utilize carboxylesterases to detoxify xenobiotics, and positively correlated with insect resistance to some insecticides. Despite the importance of CarEs in insects, carboxylesterases and their functions in wheat aphid Sitobion avenae (Fabricius) have not been clear. In this study, a sequence that encodes a carboxylesterase protein from S. avenae (SaCarE) was sequenced and cloned. After aligning the encoded amino acid sequence of the SaCarE gene with other known CarEs of insects, we found that the CarE gene was highly conserved in insects. The SaCarE mRNA levels at different developmental stages of S. avenae were gradually increased from the first instar of nymphs to adult stage. RNAi was employed to further explore its functions, in which oral ingestion of SaCarE double-stranded RNA from the third instar nymph significantly knocked down SaCarE expression, and significantly decreased ecdysis index in S. avenae. These results indicate that SaCarE is functional in S. avenae and could serve one of the potential target genes for management of S. avenae.

LETM1 Promotes Gastric Cancer Cell Proliferation, Migration, and Invasion via the PI3K/Akt Signaling Pathway

Zhang, Yunfeng,Chen, Lele,Cao, Yifan,Chen, Si,Xu, Chao,Xing, Jun,Zhang, Kaiguang The Korean Gastric Cancer Association 2020 Journal of gastric cancer Vol.20 No.2

Purpose: Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods: The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results: The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions: LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.

Anti‑infammatory and antioxidant activities of acteoside isolated from Acanthus ilicifolius var. xiamenensis

Zhang Yifan,Shen Jinhuang,Ma Xinhua,Yao Mingshuang,Zhang Yonghong,Cao Dairong 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.3

Acanthus ilicifolius var. xiamenensis (Acanthaceae), a mangrove found in southeastern China, is an herb with strong antiinflammatory property. Phytochemical study of the mangrove showed that the plant has a high content of phenylethanol glycoside acteoside (AC). In this research, the anti-inflammatory activity of acteoside on dextran sodium sulphate (DSS)-mediated mouse ulcerative colitis model were studied. For DSS- mediated colitis in mice, AC can reduce weight loss and DAI score in UC mice, suppress colon shortening and alleviate colon pathological injury. Moreover, AC treatment notably up-regulates IL-10, down-regulates the levels of IL-1β and TNF-α, and inhibits the protein expression of JAK2/STAT3, NF-κB p65, IKKα/β and IKB of colon. In addition, after AC treatment, the level of MDA and NO in colonic tissue were remarkably decreased, while the levels of GSH, SOD, and Nrf2 and HO-1 protein expression levels were significantly increased. These results indicate that AC can activate the Nrf2 signaling pathway by inhibiting the JAK/STAT, iNOS/eNOS and NF-κB signaling cascades, enhance the intestinal barrier function, and effectively reduce DSS-induced UC in mice.