Phthalocyanines as medicinal photosensitizers: Developments in the last five years

Li, Xingshu,Zheng, Bing-De,Peng, Xiao-Hui,Li, Song-Zi,Ying, Jia-Wen,Zhao, Yuanyuan,Huang, Jian-Dong,Yoon, Juyoung Elsevier 2019 Coordination Chemistry Reviews Vol.379 No.-

<P><B>Abstract</B></P> <P>Owing to their high extinction coefficients, long absorption wavelengths, and modification tunable photophysical and photochemical properties, phthalocyanines (Pcs) have been widely used as photosensitizers for photodynamic therapy (PDT). Advances made in the past five years on the development of Pcs as medicinal photosensitizers are reviewed and the main design considerations for medicinal applications of these substances are discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recent progresses made in the development of phthalocyanines for photodynamic therapy are outlined. </LI> <LI> Representative water-soluble phthalocyanines are presented. </LI> <LI> Main targeting strategies are discussed. </LI> <LI> Future challenges are also presented. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Fabrication of novel compound SERS substrates composed of silver nanoparticles and porous gold nanoclusters: A study on enrichment detection of urea

Li, Yali,Li, Qianwen,Sun, Chengbin,Jin, Sila,Park, Yeonju,Zhou, Tieli,Wang, Xu,Zhao, Bing,Ruan, Weidong,Jung, Young Mee Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.427 No.2

<P><B>Abstract</B></P> <P>A new type of surface-enhanced Raman scattering (SERS) substrate was fabricated through the layer-by-layer self-assembly of silver nanoparticles (AgNPs, av. 45nm in diameter) and porous gold nanoclusters/nanoparticles (AuNPs, av. 143nm in diameter). The development of the porosity of the AuNPs was investigated, and successful SERS applications of the porous AuNPs were also examined. As compared with AgNP films, the enhancement factor of Ag-Au compound substrates is increased 6 times at the concentration of 10<SUP>−6</SUP> M. This additional enhancement contributes to the trace-amount-detection of target molecules enormously. The contribution is generated through the increase of the usable surface area arising from the nanoscale pores distributed three-dimensionally in the porous AuNPs, which enrich the adsorption sites and hot spots for the adsorption of probe molecules, making the developed nanofilms highly sensitive SERS substrates. The substrates were used for the detection of a physiological metabolite of urea molecules. The results reached to a very low concentration of 1mM and exhibited good quantitative character over the physiological concentration range (1∼20mM) under mimicking biophysical conditions. These results show that the prepared substrate has great potential in the ultrasensitive SERS-based detection and in SERS-based biosensors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new type of SERS substrate, consisting of silver nanoparticles and porous gold nanoparticles was fabricated. </LI> <LI> An additional enhancement contribution generated from the porous characteristic of gold nanoparticles. </LI> <LI> The substrates were used for the detection of a physiological metabolite of urea molecules. </LI> <LI> The results exhibited good quantitative character over all the physiological concentration range (1∼20 mM). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Fe-N₄ complex embedded free-standing carbon fabric catalysts for higher performance ORR both in alkaline & acidic media

Li, Bing,Sasikala, Suchithra Padmajan,Kim, Dong Ha,Bak, Junu,Kim, Il-Doo,Cho, EunAe,Kim, Sang Ouk Elsevier 2019 Nano energy Vol.56 No.-

<P><B>Abstract</B></P> <P>Pt-based catalysts are suffering from the intrinsic high cost and poor stability for practical use in fuel cells. We develop a free-standing fabric type Pt-free high-performance oxygen reduction reaction (ORR) catalyst, consisting of N, Fe-codoped carbon nanofibers and graphene (N/Fe-CG) hybrids. Electrospinning is used to synthesize the free-standing fabric catalysts. Incorporation of graphene into the nanofiber structure greatly increases the electrical conductivity and catalytic surface area. X-ray photoelectron spectroscopy (XPS) analysis provides evidence that Fe-N<SUB>4</SUB> active centers are possibly formed in the catalyst, as is confirmed by electrochemical tests also. Compared to commercial Pt/C, our N/Fe-CG exhibits a similar level of catalytic activity but superior stability and methanol tolerance in both alkaline and acidic media, making it a good candidate for an ORR electrocatalyst in energy storage/conversion and other relevant applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> N, Fe-codoped free-standing carbon fabric ORR catalyst is successfully developed </LI> <LI> The catalyst shows excellent catalytic properties in both alkaline and acidic media </LI> <LI> Sample with N, Fe-codoping reveals better performance than single atom doped samples </LI> <LI> FeN<SUB>4</SUB> complex formation is confirmed by electrochemical performance and XPS analysis </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Identification of native charge-transfer status of p-aminothiolphenol adsorbed on noble metallic substrates by surface-enhanced infrared absorption (SEIRA) spectroscopy

Li, Qianwen,Wang, Yanan,Li, Yali,Park, Yeonju,Chen, Yujing,Wang, Xu,Zhao, Bing,Ruan, Weidong,Jung, Young Mee Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.204 No.-

<P><B>Abstract</B></P> <P>p-Aminothiophenol (PATP) is a preferred molecule in research on surface-enhanced Raman scattering (SERS) because of its unique characteristics of high spectral activity, easily induced charge-transfer (CT), and sensitivity to molecular structural changes. However, some aspects are still unclear, such as the initial steady state of PATP on noble metallic substrates without strong additional excitation with incident and/or induced electromagnetic radiation. Information about the initial steady state, especially the intrinsic CT state, is of great importance to elucidate the dynamic processes of CT and/or molecular structural changes under additional excitation. To investigate the native state of an adsorbed molecule, a suitable probe method that does not disrupt the native state of the whole system, including both molecules and substrates, is required. SERS is not applied in this context because of its use of high-energy visible and near-infrared light. Herein, a low-energy probe method, surface-enhanced infrared-absorption (SEIRA) spectroscopy, is employed as a suitable method for studying the native adsorption state of PATP on silver nanoisland films. The molecular structure and adsorption state were investigated. The intrinsic CT state received particular attention by analyzing the CT-related vibration of B<SUB>2</SUB> modes. Using Fourier transform infrared (FTIR), transmission SEIRA and reflection SEIRA spectroscopy, we explained why the relative intensities of some bands were different under different conditions. A quasi-standing orientation of PATP adsorbed on the substrates was also confirmed. More importantly, we demonstrated that there is no perceptible CT between PATP and silver nanoisland films; in contrast, CT generally occurs in a disruptive manner in SERS. Density functional theory (DFT) calculations and the selection rules for infrared (IR) transmission and reflection-absorption spectroscopy were used to analyze the spectra throughout the paper. SEIRA proved to be an effective technique to explore the native adsorption state of molecules without the excessive external disturbance induced by excitation. The results are very important in providing insight into molecules in surface-interface chemistry, enhanced spectroscopy and photoelectronics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The native state of PATP was investigated when adsorbed on silver substrates. </LI> <LI> FTIR and SEIRA allow a probe method with less interference on surfaces. </LI> <LI> The intrinsic charge-transfer state was analyzed through the vibration modes of B<SUB>2</SUB>. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

A reagent-assisted method in SERS detection of methyl salicylate

Li, Yali,Li, Qianwen,Wang, Yanan,Oh, Joohee,Jin, Sila,Park, Yeonju,Zhou, Tieli,Zhao, Bing,Ruan, Weidong,Jung, Young Mee Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.195 No.-

<P><B>Abstract</B></P> <P>With the explosive application of methyl salicylate (MS) molecules in food and cosmetics, the further detection of MS molecules becomes particularly important. Here we investigated the detection of MS molecules based on surface-enhanced Raman scattering (SERS) in a novel molecule/assistant/metal system constructed with MS, 4,4′-(hexafluoroisopropylidene) bis (benzoic acid) and Ag nanoparticles (AgNPs). The minimum detection concentration is 10<SUP>−4</SUP> M. To explore the function of assisted reagent, we also referred another system without assistant molecules. The result demonstrates that SERS signals were not acquired, which proves that the assistant molecules are critical for the capture of MS molecules. Two possible mechanisms of MS/assistant/AgNPs system were speculated through two patterns of hydrogen bonds. The linker molecules acted as the role of the bridge between metallic substrates and target molecules through the molecular recognition. This strategy is very beneficial to the expanding of MS detection techniques and other hydrogen bond based coupling detections with SERS.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel molecule/assistant/metal system was constructed to achieve the SERS detection of methyl salicylate. </LI> <LI> The intermolecular hydrogen bond was employed as the driving force to accomplish the assembly. </LI> <LI> The obstacle of non-adsorption of target molecules on substrates was solved through the hydrogen-bond-based assembly method. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Pollen record of the mid- to late-Holocene centennial climate change on the East coast of South Korea and its influential factors

Song, Bing,Yi, Sangheon,Jia, Hongjuan,Nahm, Wook-Hyun,Kim, Jin-Cheul,Lim, Jaesoo,Lee, Jin-Young,Sha, Longbin,Mao, Limi,Yang, Zhongyong,Nakanishi, Toshimichi,Hong, Wan,Li, Zhen Elsevier 2018 Journal of Asian earth sciences Vol.151 No.-

<P><B>Abstract</B></P> <P>To understand historical climate change in western Pacific coastal areas, a sediment core (SOJ-2) from the stable sedimentary environment of the Songjiho Lagoon on the east coast of South Korea was obtained for centennial-resolution palynological analysis. The ages of the SOJ-2 core is well controlled by carbon 14 dating with high-resolution accelerator mass spectrometry (AMS), and the results indicated a general warm to cold climate trend from the mid-Holocene to the present, which can be divided into two different stages: a warmer stage between 6842 and 1297 cal yr BP and a colder stage from 1297 cal yr BP to the present, with fluctuations during these stages. The climate was wetter from 6842 to 6227 cal yr BP and 4520 to 1297 cal yr BP and was drier from 6227 to 4520 cal yr BP. The climate changed to cold and dry during the period from 1297–425 cal yr BP. The impact of human activity on the climate began at approximately 1297 cal yr BP and became pronounced starting in 425 cal yr BP. The general cooling trend may represent a response to decreasing solar insolation; however, the relative dryness or wetness of the climate may have been co-determined by westerlies and the East Asian summer monsoon (EASM). The climate had a teleconnection with the North Atlantic region, resulting from changes in solar activity. Nevertheless, EI Niño–Southern Oscillation (ENSO) activity played an important role in impacting the EASM changes in western Pacific coastal areas.</P> <P><B>Highlights</B></P> <P> <UL> <LI> There is a centennial resolution climate record from 6842 cal yr BP to present. </LI> <LI> The general cooling trend was probably triggered by decreasing solar insolation. </LI> <LI> The precipitation was co-determined by westerlies and the East Asian Summer Monsoon. </LI> <LI> The ENSO activity may be an important factor for East Asian Summer Monsoon change. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Highly efficient hydrogen evolution catalysis based on MoS₂/CdS/TiO₂ porous composites

Du, Jimin,Wang, Huiming,Yang, Mengke,Zhang, Fangfang,Wu, Haoran,Cheng, Xuechun,Yuan, Sijie,Zhang, Bing,Li, Kaidi,Wang, Yina,Lee, Hyoyoung Elsevier 2018 International journal of hydrogen energy Vol.43 No.19

<P><B>Abstract</B></P> <P>Efficient production of hydrogen through visible-light-driven water splitting mechanism using semiconductor-based composites has been identified as a promising strategy for converting light into clean H<SUB>2</SUB> fuel. However, researchers are facing lots of challenges such as light absorption and electron-hole pair recombination and so on. Here, new sheet-shaped MoS<SUB>2</SUB> and pyramid-shaped CdS <I>in-situ</I> co-grown on porous TiO<SUB>2</SUB> photocatalysts (MoS<SUB>2</SUB> CdSTiO<SUB>2</SUB>) are successfully obtained <I>via</I> mild sulfuration of MoO<SUB>3</SUB> and CdO coexisted inside porous TiO<SUB>2</SUB> monolith by a hydrothermal route. The scanning electron microscopy and transmission electron microscopy results exhibit that the MoS<SUB>2</SUB> CdSTiO<SUB>2</SUB> composites have average pore size about 500 nm. The 3%MoS<SUB>2</SUB> 10%CdSTiO<SUB>2</SUB> demonstrated excellent photocatalytic activity and high stability for a hydrogen production with a high H<SUB>2</SUB>-generation rate of 4146 μmol h<SUP>−1</SUP> g<SUP>−1</SUP> under visible light irradiation even without noble-metal co-catalysts. The super photocatalytic performance of the visible-light-driven hydrogen evolution is predominantly attributed to the synergistic effect. The conduction band of MoS<SUB>2</SUB> facilitates in transporting excited electrons from visible-light on CdS to the porous TiO<SUB>2</SUB> for catalytic hydrogen production, and holes to MoS<SUB>2</SUB> for inhibiting the photocorrosion of CdS, respectively, leading to enhancing the efficient separation of electrons and holes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MoS<SUB>2</SUB>-CT photocatalysts have been successfully synthesized by two-step method. </LI> <LI> The porous structure can enhance photogenerated electron-hole pairs separation. </LI> <LI> The 3% MoS<SUB>2</SUB>-CT shows an excellent H<SUB>2</SUB> evolution rate of 4146 μmol h<SUP>−1</SUP> g<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Grinding Marks on Ultra-Precision Grinding Spherical and Aspheric Surfaces

Bing Chen,Bing Guo,Shichun Li,Zhaohui Deng,Qingliang Zhao 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.4 No.4

Grinding marks are regard as a great obstacle to manufacture spherical and aspheric surfaces with higher surface quality, lower energy and wastage. The scallop-height was studied for optimizing the grinding parameters firstly to reduce its effect on grinding marks. Secondly, the expression of grinding points distribution was established to characterize the grinding marks caused by the radial run-out of grinding wheel. And then, the aspheric grinding experiments of monocrystalline silicon were carried out to investigate the influence of grinding marks on surface quality. The experiments revealed that the remarkable grinding marks with patterned grinding points distribution would cause more fractures and roughness, deeper grooves, and more inhomogeneous surface quality compared with the weak grinding marks. The discriminating standard of grinding marks was established, and the grinding parameters were optimized for homogenizing the grinding points distribution by this discriminating standard to reduce the grinding marks in actual grinding process. Finally, the large size infrared lens was ground with high surface quality by the optimized grinding parameters, and the results of surface quality demonstrate that the discriminating standard was effective. This research provides references and ideas for grinding aspherical surface with high surface quality and efficiency, low energy and wastage.

A Novel Method of Reducing the Cogging Torque in SPM Machine with Segmented Stator

Li-Bing Jing,Lin Liu,Rong-Hai Qu,Qi-Xing Gao,Zheng-Hao Luo 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

The method of stator segmentation is generally taken to enhance the electromagnetic performance of surface-mounted permanent magnet (SPM) machine and reduce its production cost. Based on the model with single slot, the expressions of cogging torque in machine with uniform or non-uniform segmentations are deduced and the optimal combination is given. Moreover, this paper discusses a structured skewing method and put forward a novel stator structure model to reduce the cogging torque in segmented permanent magnet machine. The model can reduce the cogging torque amplitude by shifting a proper angle of slot-opening. The shifting angle formula for analysis can also be suitable for other permanent machine with segmented stator. Finally the results of finite element simulation are given to prove that the method is effective and feasible.

Design and implementation of an improved MA-APUF with higher uniqueness and security

Li, Bing,Chen, Shuai,Dan, Fukui Electronics and Telecommunications Research Instit 2020 ETRI Journal Vol.42 No.2

An arbiter physical unclonable function (APUF) has exponential challenge-response pairs and is easy to implement on field-programmable gate arrays (FPGAs). However, modeling attacks based on machine learning have become a serious threat to APUFs. Although the modeling-attack resistance of an MA-APUF has been improved considerably by architecture modifications, the response generation method of an MA-APUF results in low uniqueness. In this study, we demonstrate three design problems regarding the low uniqueness that APUF-based strong PUFs may exhibit, and we present several foundational principles to improve the uniqueness of APUF-based strong PUFs. In particular, an improved MA-APUF design is implemented in an FPGA and evaluated using a well-established experimental setup. Two types of evaluation metrics are used for evaluation and comparison. Furthermore, evolution strategies, logistic regression, and K-junta functions are used to evaluate the security of our design. The experiment results reveal that the uniqueness of our improved MA-APUF is 81.29% (compared with that of the MA-APUF, 13.12%), and the prediction rate is approximately 56% (compared with that of the MA-APUF (60%-80%).