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A coral-like ZnO/C-ZnFe2O4 (Z/C-ZFO) photocatalyst was synthesized by simulating the structural characteristics of coral, since its structure is conducive to the capture and absorption of light. Th...

Fingerprints remain topologically unchanged in one's whole life, and therefore, have been used as a means to biometrically identify individuals in forensic investigations, law enforcement and access control. Appropriate methods are essential to obtain high-quality fingerprint images. In this contribution, an aggregation-induced emission luminogen tetraphenylethene-based dye FLA-2 was synthesized and characterized for the visualization of latent fingerprints (LFPs). LFPs can be directly visualized by incubating with the dye FLA-2 solution. And, after a cyanoacrylate fuming method pre-treatment stage, fine fingerprint structures can be obtained from level-1 to level-3 details. Two methods were compared using resolution, fluorescence intensity, and scanning electron microscopy imaging to investigate the influence of the cyanoacrylate fuming method pre-treatment stage. Furthermore, the visualization of old LFPs (7 d, 16 d and 30 d) on glass slides, aluminum foil and coin substrates also became effective after the pre-treatment step. The fluorescent LFP images mentioned above were all validated by using an automated fingerprint identification system obtaining positive matches. These results demonstrate the potential of this method to be applied to visualizing LFPs in the field of public security.

Abstract Gadolinium-based nanomaterials can not only serve as contrast agents but also contribute to sensitization in the radiotherapy of cancers. Among radiotherapies, carbon ion irradiation is considered one of the superior approaches with unique physical and biological advantages. However, only a few metallic nanoparticles have been used to improve carbon ion irradiation. In this study, gadolinium oxide nanocrystals (GONs) were synthesized using a polyol method to decipher the radiosensitizing mechanisms in non-small cell lung cancer (NSCLC) cell lines irradiated by carbon ions. The sensitizer enhancement ratio at the 10% survival level was correlated with the concentration of Gd in NSCLC cells. GONs elicited an increase in hydroxyl radical production in a concentration-dependent manner, and the yield of reactive oxygen species increased obviously in irradiated cells, which led to DNA damage and cell cycle arrest. Apoptosis and cytostatic autophagy were also significantly induced by GONs under carbon ion irradiation. The GONs may serve as an effective theranostic material in carbon ion radiotherapy for NSCLC. Graphical Abstract

A series of conjugated donor–acceptor (D–A) block copolymers (BCPs) were synthesised using a one-pot Stille coupling polycondensation reaction. This involved reaction between a series of mono-bromo-functionalised Poly3-hexylthiophene (P3HT) polymers (P3HT-Br, Mn : 17, 21 and 43 kg/mol) and [N, N′-bis(2-decyl-tetradecyl)-1,7-dibromo-3,4,9,10-perylene diimide (PBI) and [2,5-bis(trimethylstannyl)-thiophene] (T) monomers. Purification using preparative gel permeation chromatography (GPC) removed any excess P3HT and resulted in BCPs with low polydispersity index values. The P3HT-b-PBIT BCPs were characterised using 1H-NMR and Fourier-transform infrared spectroscopy. When compared to a P3HT/PBIT polymer blend, the D–A BCP films exhibited a remarkably fine structure with a nanoscale morphology. These results indicated that these D–A BCPs have the potential for use as nanostructured active layers in polymer solar cells.

All-conjugated donor-acceptor block copolymers (BCP) were synthesized in a one-pot reaction by a Stille coupling polycondensation through a terminal functional polymer copolymerization process. Mono bromo end-functionalized P3HT samples with various molecular weights (P3HT-Br, Mn: 5, 9, and 26 kg/mol) were copolymerized with AA (N,Nʹ-Bis(2-decyl-1-tetradecyl)-2,6-dibromonaphthalene-1,4,5,8-tetracarboxylic acid bisimide, NDI) and BB (5,5′-bis(trimethylstannyl)-2,2′-bithiophene) type monomers. Further purification by preparative GPC removed excess P3HT to yield block copolymers of low polydispersities with different donor and acceptor block chain lengths. The block copolymers were characterized by 1H-NMR and UV–vis absorption and FTIR spectroscopy. The optical properties, film morphologies, and optoelectronic properties of the block copolymer were strongly influenced by the donor and acceptor block chain lengths. Furthermore, the fully conjugated D-A block copolymer films exhibited fine structures, smooth film morphologies, and better OPV performance than those features of P3HT/PNDIT2 polymer blends. In polymer solar cells based on the various block copolymer as active layers, the device power convention efficiency was improved by maintaining the acceptor block content at 40–50 kg/mol and increasing the P3HT chain from 5 to 26 kg/mol.

The generalized parallel mechanisms (GPMs) become a new feasible research topic to explore the advantages and overcome the shortcomings of the traditional parallel mechanisms (TPMs). This paper aims to address the challenge of the synthesis method for the GPMs with large rotational angles and integrated end-effectors (or configurable platforms). A sufficient condition for the independent rotations is presented and a design framework for constructing independent rotational degree of freedom (DOF) is developed. Using the set mapping and the Lie group theory, a method for synthesizing GPMs with hybrid structures is proposed on the basis of the obtained sufficient condition and the design framework. This method provides a way to connect the symmetric 0-DOF closed-loop kinematic chains with the parallel limbs to preserve the motions of both the parallel limbs and the elements in the closed-loop chains. A 3T3R GPM with 3-dimension large rotational angles and a class of 4-DOF and 6-DOF GPMs with 1-DOF integrated end-effectors are synthesized using the proposed method. The orientation workspace of the example GPMs are analyzed and discussed to reveal the high rotational capability. The obtained GPMs are suitable for the occasions that require high rotational performance, assembly, pick-and-place, drilling and other industrial applications.

Biomass char is accepted as an environmentally friendly energy resource, and is promising for NO removal in industrial furnaces. NO reduction with biomass char (rice husk) was investigated in a fixed-bed quartz reactor. The influence of CO concentration, reaction temperature, initial NO concentration, and char loading on the NO reduction were evaluated. The results showed that the overall NO reduction reaction was dominated by the direct reaction of NO with char without CO. Increasing CO concentration resulted in an enhanced catalytic reaction between NO and CO over the char surface and a decreased carbon consumption of char. With decreasing temperature, the influence of CO concentration on NO reduction was strengthened. Over the test temperature range, char provided a surface to catalyze the NO&ndash, CO reaction at excess CO/NO ratio. Increasing the initial NO concentration led to an increasingly significant influence on NO reduction with the enhanced CO/NO ratio. With increased char loading, the enhancement of NO reduction became unobservable for excess CO/NO ratio. Reaction orders of NO and activation energy for NO reduction by char were 0.71 and 60.21 kJ&middot, mol&minus, 1, respectively, against 0.82 and 34.60 kJ&middot, 1, respectively, for NO reduction by CO, catalyzed by char.

In this paper, a photoinduced electron transfer (PET)& twisted intramolecular charge transfer (TICT)-based fluorescent probe (1) for detecting biothiols (GSH/Cys/Hcy) and hydrogen sulfide with fluorescence turn on was developed. The probe could recognize hydrogen sulfide over primary ions and selectively detect GSH/Cys/Hcy over other amino acids with fluorescence turn-on (an ESIPT process). H2S can be distinguished from GSH/Cys/Hcy with wavelength shift by UV–Vis spectra. In addition, detection limits for H2S/GSH/Cys/Hcy of probe 1 were 1.42 μM (0–100 μM), 0.13 μM (0–40 μM), 0.27 (0–30 μM), 0.22 μM (0–40 μM), respectively. The proposed thiolysis of the 2,4-dinitrochlorophenyl ether reaction in identification process was verified by the characteristic peak in 1H NMR and HRMS spectra. Finally, the biological imaging experiments and low cytotoxicity investigations in HeLa cells demonstrated that probe 1 could provide a promising method for the determination of H2S and biothiols in aqueous solution and living cells.

Development of highly efficient photocatalysts is a primary goal in the photocatalysis domain among which reusable composites with a synergistic photocatalytic effect have attracted extensive interest. The ability of catalysts to capture light determines their photocatalytic effect, and porous or hollow photocatalysts are more conducive to the entry and reflection of light. The goal of this research is to develop a type of visible-light-driven, double-shell photocatalyst with high antibacterial activity and excellent cycling stability. Photocatalysts were fabricated using hollow graphitized ZnFe2O4 nanospheres (G-ZnFe2O4) as the carrier. After G-ZnFe2O4 was functionalized with a polydopamine (PDA) template layer, Ag nanoparticles (NPs) and cubic AgCl NPs were in situ generated on the surface of the PDA/G-ZnFe2O4 nanospheres successively. Then, the PDA template was removed using KOH solution, and double-shell Ag/AgCl/G-ZnFe2O4 nanocubes (referred to as DAGZNs) with excellent photocatalytic antibacterial activity were constructed. The DAGZNs showed excellent antibacterial properties against Staphylococcus aureus and Escherichia coli. The efficient synergistic photocatalytic antibacterial activity coupled with magnetic separability and recyclability of DAGZNs make them potential for practical application in water purification and environmental protection. The method of designing and synthesizing double-shell structures to enhance photocatalysis may also be extended to synthesis of other photocatalytic and optical materials.

Dexterous hands are an important end-effector of robots, but their relatively low carrying capacity, small workspace and poor task adaptability are the key factors that restrict their wide application. To overcome these shortcomings of dexterous hands, a novel Lie-group-based synthesis method that extends the 3-[P][S] parallel mechanisms (PMs) to dexterous hands is presented, and a class of three-finger dexterous hands with parallel finger structure is obtained. The multimode operation is proposed by designing a double-slider palm that provides the hands with a large workspace and high task adaptability. The operation types are presented, and the dexterous in-hand manipulations in all modes are analyzed by means of Lie group theory. In addition, the equivalent structural characteristics of pinching objects are classified to elucidate the motion types and the rotational properties of the pinched objects. The inverse kinematics of fingers is presented and is used to identify the input–output relationships. Finally, the workspaces of the fingers are determined according to the result of the inverse kinematics, and the relationships between the size and displacements of the pinched object are presented. The proposed dexterous hands overcome the problems of low carrying capability, small workspace, and weak in-hand manipulation ability that are encountered with the traditional dexterous hands, which are underactuated and are built with a series finger structure, and can be potentially applied to various application domains, such as services, industry, and rescue.

Raw kaolinite (kaol) was experimentally transformed to P-type hydrated silica aluminate (HSA-P). After treated by LaCl 3 ·7H 2 O solution, the final product of La-loaded for P-type hydrated silica aluminate (HSA-P-La) was obtained. The middle and final products were characterized using fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM). Kaol, HSA-P, HSA-P-La was introduced into PP with intumescent flame retardants (IFR), respectively. And their effect on the flame retardant and thermal properties of PP composites was studied by limiting oxygen index (LOI), vertical burning test, cone calorimeter test (CCT) and thermogravimetric analysis (TGA). The LOI increases from 18.0% of neat PP to 31.2 in composite of 75 wt% PP/25 wt % IFR, further increases to 32.5, 35.1, 37.5 in 75 wt% PP/23.5 wt % IFR/1.5 wt% Kaol, HSA-P or HSA-P-La, respectively. CCT results show heat release content and rate is best controlled in PP/IFR/HSA-P-La composite. Morphology observation indicates the char layer of PP/IFR/HSA-P-La composite is most compact and thick, which guarantees excellent fire resistance. At same time the effect of HSA-P/HSA-P-La was also compared with generally used A-type hydrated silica aluminate (HSA-A)/HSA-A-La. Anyway HSA-P/HSA-P-La exhibited higher efficiency than HSA-A/HSA-A-La in both flame retardancy and thermostability.

With the deepening and refinement of research, the traditional parallel mechanisms (PMs) have become increasingly hard to satisfy the demands of high rotational performance, decoupled motions, or some other specific motion properties. This paper focuses on the synthesis of a class of generalized parallel mechanisms (GPMs), which are capable of preserving the advantages and overcoming the shortcomings of the traditional PMs. Inspired by the closed-loop mechanisms with one or two dimensional high output performance and based on the characteristics of the set mapping and the group operations, a novel method about the synthesis of GPMs is proposed. By means of this method, a type of four degree of freedom (4-DOF) GPMs which contain 2T2R (T denotes a translational DOF and R represents a rotational DOF), 3T1R, and 1T3R categories are synthesized and further a kind of 5-DOF GPMs which are divided into 3T2R and 2T3R categories are obtained. The synthesis method is universal for the design of the GPMs and the proposed GPMs possess high performance because the articulated platforms are evolved from the well-known planar closed-loop linkage mechanisms.

Radiotherapy is one of the major therapeutic strategies for cancer treatment. In the past decade, there has been growing interest in using high Z (atomic number) elements (materials) as radiosensitizers. New strategies in nanomedicine could help to improve cancer diagnosis and therapy at cellular and molecular levels. Metal-based nanoparticles usually exhibit chemical inertness in cellular and subcellular systems and may play a role in radiosensitization and synergistic cell-killing effects for radiation therapy. This review summarizes the efficacy of metal-based NanoEnhancers against cancers in both in vitro and in vivo systems for a range of ionizing radiations including gamma-rays, X-rays, and charged particles. The potential of translating preclinical studies on metal-based nanoparticles-enhanced radiation therapy into clinical practice is also discussed using examples of several metal-based NanoEnhancers (such as CYT-6091, AGuIX, and NBTXR3). Also, a few general examples of theranostic multimetallic nanocomposites are presented, and the related biological mechanisms are discussed.

The design of unique structures for semiconductor photocatalysts is one of the most effective approach to stimulate their performance toward solar–to–chemical energy conversion. Herein, an interesting scheme has been introduced to produce hollow porous ZnFe2O4/AgCl/Ag/C nanotubes on the PDA@PANI nanofibers by a simple combined PANI capturing–PDA embedding–in situ graphitization process. In a first step, PDA@PANI were first prepared via a coaxial electrospinning process, followed by PANI capturing transition metal ions (Zn2+ and Fe2+) with the assistance of 2,5–dihydroxy–1,4–benzenedicarboxylic acid to convert these metal ions into PDA@PANI@MOF–74–Zn/Fe through thermal treatment. Then, AgCl cubes and Ag NPs were synthesized via in–situ embedding with various active groups of the PDA and its reducibility. At last, after calcination of the PDA@PANI@MOF–74–Zn/Fe/AgCl/Ag, ZnFe2O4/AgCl/Ag/C nanotubes with uniform distribution of graphitic carbon were successfully fabricated. Benefiting from the novel hollow porous structure, the obtained ZnFe2O4/AgCl/Ag/C exhibited outstanding H2 evolution activity (e.g., 7524 µmol h−1 g−1) and high stability without engaging any cocatalyst, which is among the highest reported for ZnFe2O4–based materials with different morphologies and nanostructures.

Herein, ZnFe2O4/ZnO hollow porous spheres (HPS) of the dual–template and self–dissolution design, on which monolayer nitrogen–doped graphene (NG) is in situ grown by chemical vapor deposition, are applied for realizing effective photocatalytic degradation of antibiotics. The constructed photocatalyst possesses a hollow interior for strengthening visible–light absorption ability and offering large surface area, a porous for facilitating rapidly mass transfer capability, a thin shell for shortening the migration distance of photo–generated electrons (e⎺), tight adhesion for expediting charge separation and mobility, and a monolayer NG cage surface for adsorbing and stimulating activating antibiotics molecules. Benefiting from the novel HPS structure, the prepared ZnFe2O4/NG/ZnO HPS photocatalyst exhibits high activity under visible–light irradiation, currently the largest to the best of our knowledge, which is much enhanced compared with those of the ZnFe2O4/NG/ZnO solid spheres and ZnFe2O4/NG hollow spheres.

We synthesized a rhodamine-based fluorescent probe 1 , which could be used for the optical detection of Fe 3+ . Compared with other commonly coexistent metal ions in aqueous system, it exhibited high sensitivity and selectivity for Fe 3+ , and the detection limit was only 4.2 × 10 −8 M. In addition, the rapid enhancement of fluorescence intensity on addition of Fe 3+ provided a good method for the detection of Fe 3+ . What’s more, the colour change was visible and distinct, so it could be used for the naked-eye detection of Fe 3+ . Furthermore, the fluorescent probe was proved to be effective when used for sensing Fe 3+ in living cells and zebrafish. These results showed its values in biological aspects.

This article focuses on the synthesis and analysis of a class of novel 2T2R (T denotes Translation and R denotes Rotation) and 3T2R parallel mechanisms (PMs) with large decoupled output rotational angles. Two articulated moving platforms (AMPs) composed by revolute joints are proposed. A common parallelogram and an evolution parallelogram which are used to orient the rotation axes of the AMPs are designed and analyzed. By means of Lie group theory, the limbs connected in the AMPs are enumerated and two types of 2T2R PMs are synthesized. Then, based on the proposed 2T2R PMs, a family of 3T2R PMs are obtained through adding a translational degree of freedom (DOF). The fact that the orthogonal arrangement of the revolute joints in the AMPs eliminates the interference between the two rotations guarantees the high rotational performance of the manipulators. Finally, the inverse kinematics of the example PM is conducted and the workspace is obtained to illustrate the high rotational capability.

In this work, a novel single macromolecular intumescent flame retardant (DT-M) was prepared by self-assembly of diethylenetriamine penta-(methylenephosphonic) acid with melamine, and modified layered double hydroxides (LDH) were also prepared by intercalating phytic acid into LDHs. The chemical structures of DT-M and phytic acid intercalated LDHs (PA–LDH) were fully characterized by different analytical instruments, and then were introduced into PLA by melt compounding to prepare a flame retardant biodegradable PLA composite. The fire performance evaluation of PLA composites by limiting oxygen index (LOI), vertical burning (UL-94) and cone calorimeter tests indicated that the introduction of 14% DT-M and 1% PA–LDH increased the LOI value from 19.4 to 38.9%, upgraded the UL-94 rating from no rating to V-0, and decreased the peak heat release rate from 812 to 301 kW m−2. The analysis for decomposition products of PLA composite and the observation of morphology of the char suggested that DT-M and PA–LDH took effects in both condensed phase through promoting char formation and gas phase through releasing inert gases.

A tetraphenylethene-based dye (FLA-1) was used to develop for enhancing the visualization of the latent fingerprints on the surfaces of various substrates. The resolution of the fingerprints visualized by the probe FLA-1 is enough to offer a positive match according to the information supplied from a police database. Experimental results confirm the accuracy of using the probe for LFPs detection.

A bio-polyelectrolyte (PC) was synthesized by reacting phytic acid (PA) with casein (CS), and used as the shell materials to microencapsulate ammonium polyphosphate (APP). The obtained core-shell structured flame retardant (PC@APP) was incorporated into polylactic acid (PLA). The dispersion of PC@APP was greatly improved. As a result, the elongation at break and notched impact strength were improved from 6.9% and 3.5 KJ/m 2 of neat PLA sample to 14.4% and 4.7 KJ/m 2 of PLA samples containing 5%PC@APP. Moreover, the fire resistance of PLA/5%PC@APP composites was also enhanced. The limiting oxygen index (LOI) value was increased from 19.6% to 28.3%; the vertical burning (UL-94) rating was upgraded from no rating to V-0; and the peak heat release rate value was decreased from 935.8 kW/m 2 to 747.9 kW/m 2 . It is suggested that the well-dispersed PC@APP alters the degradation routine of PLA matrix, leading to the rapid formation of physical barriers.

Feifei Li,1,2,* Zihou Li,2,3,* Xiaodong Jin,1 Yan Liu,1 Pengcheng Zhang,1,2 Ping Li,1 Zheyu Shen,3 Aiguo Wu,3 Weiqiang Chen,1 Qiang Li1 1Institute of Modern Physics, Chinese Academy of Sciences, Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou 730000, China; 2University of Chinese Academy of Sciences, Beijing 100049, China; 3Key Laboratory of Magnetic Materials and Devices, Chinese Academy of Sciences, Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China *These authors contributed equally to this work Background: Gadolinium-based nanoparticles (GdNPs) have been used as theranostic sensitizers in clinical radiotherapy studies; however, the biomechanisms underlying the radiosensitizing effects of GdNPs have yet to be determined. In this study, ultra-small gadolinium oxide nanocrystals (GONs) were employed to investigate their radiosensitizing effects and biological mechanisms in non-small-cell lung cancer (NSCLC) cells under X-ray irradiation.Method and materials: GONs were synthesized using polyol method. Hydroxyl radical production, oxidative stress, and clonogenic survival after X-ray irradiation were used to evaluate the radiosensitizing effects of GONs. DNA double-strand breakage, cell cycle phase, and apoptosis and autophagy incidences were investigated in vitro to determine the radiosensitizing biomechanism of GONs under X-ray irradiation.Results: GONs induced hydroxyl radical production and oxidative stress in a dose- and concentration-dependent manner in NSCLC cells after X-ray irradiation. The sensitizer enhancement ratios of GONs ranged between 19.3% and 26.3% for the NSCLC cells under investigation with a 10% survival rate compared with that of the cells treated with irradiation alone. Addition of 3-methyladenine to the cell medium decreased the incidence rate of autophagy and increased cell survival, supporting the idea that the GONs promoted cytostatic autophagy in NSCLC cells under X-ray irradiation.Conclusion: This study examined the biological mechanisms underlying the radiosensitizing effects of GONs on NSCLC cells and presented the first evidence for the radiosensitizing effects of GONs via activation of cytostatic autophagy pathway following X-ray irradiation. Keywords: gadolinium oxide nanocrystal, radiosensitization, cytostatic autophagy, apoptosis, oxidative stress

In this work, a novel sulfur-based flame retardant (SA-M) was synthesized by the self-assembly of melamine and sulfamic acid. The chemical structure of SA-M was fully characterized. SA-M, in company with Al2O3, was then introduced into polyamide 11 (PA 11) by melt compounding in order to improve the fire resistance of the polymer substrate. The observation by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) indicated the well dispersion of SA-M in PA 11 matrix. The fire performance of PA 11 composites was evaluated by limiting oxygen index (LOI), vertical burning (UL-94), and cone calorimeter tests, respectively. The results showed that the presence of 17.5% SA-M and 2.5% Al2O3 increased the LOI value from 22.4% to 30.9%, upgraded the UL-94 rating from no rating to V-0, significantly eliminated the melt dripping, and decreased the peak heat release rate from 1024 to 603 kW/m2. The thermal behaviors were investigated by thermogravimeric analysis (TGA) and TGA-Fourier transform infrared spectroscopy (FTIR). It was suggested that SA-M took effects mainly in gas phase by diluting the combustible fuel, leading to the improvement of the fire resistance of PA 11.

In this work, the form-stable phase change material (PCM) was prepared by absorbing tetradecanol (TD) into expanded graphite (EG). Then, the obtained TD/EG was coated with graphene oxide (GO) through electrostatic self-assembly to prepare a novel composite PCM (TD/EG-GO). The morphology, phase change and thermal properties of TD/EG-GO were fully discussed. The DSC analysis shows that the TD/EG-GO composite melts at 35.2 °C with latent heat value of 189.5 J/g and freezes at 34.9 °C with latent heat value of 187.9 J/g. The thermal cycling test results reveal that the latent heat of TD/EG-GO composite decrease by less than 1% after 500 thermal cycles, indicating that the structure of GO-coated EG efficiently prevents the leakage of TD. The thermal stability and thermal conductivity of TD/EG-GO composite are also improved compared with that of uncoated TD/EG, demonstrating the multiple benefits of surface coating of GO.

Nano-rolled and nano-sheeted silicates were fabricated from nature kaolinite (Kaol). And their structure was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and so on. The two nano-sized silicates acted as synergists to enhance fire retardant performance of polypropylene (PP) with intumescent flame-retardants (IFR) together. The limited oxygen index (LOI) of PP is only 18%, incorporation of 25 wt% IFR lifted the LOI to 31.1%, further increase to 34.5 and 35.5% by 1.5 wt% substitution of nano-rolled Kaol (N-Kaol) or exfoliated Kaol (E-Kaol) with same amount of IFR, respectively. Moreover, each modified Kaol can effectively control melt dripping to help PP reach UL-94 V-0 grade. In cone test, the resultes showed that the peak heat release rate (pHRR) values of PP/IFR/N-Kaol (269 kW/m2) and PP/IFR/E-Kaol (319 kW/m2) composites were reduced by 38.6 and 27.2% compared to that of PP/IFR (438 kW/m2), respectively; the smoke release was similar to the heat release. Continue increased char percentage documented the promotion on charring from E-Kaol and N-Kaol. The PP/IFR/N-Kaol exhibited the best char strength. Morphology observation on macro/micro-structure of char and real-time FTIR demonstrated that N-Kaol can be beneficial to forming homogenous and compact intumescent char layer through “double effect” of barrier and pillar-like support during burning, especially after 340 s, compared with the PP/IFR containing E-Kaol. This special structure of char layer can effectively limit the flow and transfer of inflammable gases and heat between underlying matrix and outside environment.

Kaolinite nanoroll (Kaol nanoroll) was prepared from raw kaolinite (Kaol), and was then incorporated into polypropylene (PP) with intumescent flame retardant (IFR) to improve the fire performance. The characterization by Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD) and transmission electron microscope (TEM) revealed that Kaol was transformed from platy to nanoroll. The flammability and thermostability evaluation by limit oxygen index (LOI), vertical burning test (UL-94), cone calorimeter test (CONE) and thermal-gravimetric analysis (TGA) showed that Kaol nanoroll showed better synergistic effect on thermal stability and fire resistance to PP than Kaol. CONE data showed that the peak heat release rate (PHRR) values of PP/IFR (436 kW/m2), PP/IFR/1.5Kaol (372 kW/m2) and PP/IFR/1.5Kaol nanoroll (269 kW/m2) nanocomposites were reduced by 70.3, 74.4 and 81.7% compared to that of neat PP (1474 kW/m2), respectively. The TGA results indicated that Kaol nanoroll can significantly improve the thermal stability and char residues of Kaol PP/IFR nanocomposites. Morphology and structure analysis of char by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) illustrated that Kaol nanoroll was beneficial to improving the char quality of Kaol PP nanocomposite. The FTIR spectra at different temperatures revealed that Kaol nanoroll will promote the formation of charred layers with the P O and P O complexes in the condensed phase to protect the substrate.

A new Schiff base derivative, namely 4-(((4-(bis(pyridin-2-ylmethyl) amino) phenyl) imino) methyl)-N,N-diethylaniline, with more than one pyridine ring and two benzene rings was synthesized successfully. And then its corrosion inhibition properties were estimated in 1.0 M HCl by weight loss experiments, potentiodynamic polarization and electrochemical impedance spectroscopy methods. The results showed that 4-(((4-(bis(pyridin-2-ylmethyl) amino) phenyl) imino) methyl)-N,N-diethylaniline is a mixed type inhibitor and follows Langmuir adsorption isotherm. SEM-EDX and XPS techniques were used for surface analysis. Meanwhile, quantum chemical calculation using density functional theory (DFT) established the correlation between the structure and corrosion inhibition efficiency. Molecular dynamic simulation was adopted to investigate the adsorption behavior on mild steel surface.

Expandable graphite (EG) has attracted more and more attention in fire science society due to its excellent char-forming ability, however, it cannot meet commercial flame-retardant requirements because of the low intensity of the char. This work reported our very recent efforts on improving the char quality of EG by introducing melamine (MEL) in order to enhance the fire resistance and thermal stability of polyamide 11 (PA 11) composite. The flammability characterized by limiting oxygen index, UL-94 vertical burning, and cone calorimeter (cone) tests shows that the presence of both EG and MEL can significantly improve the flame retardancy and thermal stability of PA 11 composites. The scanning electron microscopic analysis shows that EG and MEL are beneficial to form compact char layers that can isolate the matrix from heat and oxygen. It is proposed that the formation of hydrogen bonds between MEL and PA 11 are crucial for improving the flame retardancy of the composites.

Xi Liu,1–4 Yan Liu,1–4 Pengcheng Zhang,1–4 Xiaodong Jin,1–3 Xiaogang Zheng,1–4 Fei Ye,1–4 Weiqiang Chen,1–3 Qiang Li1–3 1Institute of Modern Physics, 2Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, 3Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou, 4School of Life Science, University of Chinese Academy of Sciences, Beijing, People’s Republic of China Abstract: Reductive drug-functionalized gold nanoparticles (AuNPs) have been proposed to enhance the damage of X-rays to cells through improving hydroxyl radical production by secondary electrons. In this work, polyethylene glycol-capped AuNPs were conjugated with tirapazamine (TPZ) moiety, and then thioctyl TPZ (TPZs)-modified AuNPs (TPZs-AuNPs) were synthesized. The TPZs-AuNPs were characterized by transmission electron microscopy, ultraviolet-visible spectra, dynamic light scattering, and inductively coupled plasma mass spectrometry to have a size of 16.6±2.1nm in diameter and a TPZs/AuNPs ratio of ~700:1. In contrast with PEGylated AuNPs, the as-synthesized TPZs-AuNPs exhibited 20% increment in hydroxyl radical production in water at 2.0Gy, and 19% increase in sensitizer enhancement ratio at 10% survival fraction for human hepatoma HepG2 cells under X-ray irradiation. The production of reactive oxygen species in HepG2 cells exposed to X-rays in vitro demonstrated a synergistic radiosensitizing effect of AuNPs and TPZ moiety. Thus, the reductive drug-conjugated TPZs-AuNPs as a kind of AuNP radiosensitizer with low gold loading provide a new strategy for enhancing the efficacy of radiation therapy. Keywords: AuNPs, radiation enhancement, synergistic effect, human hepatoma cells, hydroxyl radical production

Radiotherapy is an important modality for tumor treatment. The central goal of radiotherapy is to deliver a therapeutic dose to the tumor as much as possible whilst sparing the surrounding normal tissues. On one hand, heavy ion radiation induces maximum damage at the end of the track (called the Bragg Peak). Hadron therapy based on heavy ions is considered superior to conventional X-rays and γ-rays radiations for tumors sited in sensitive tissues, childhood cases and radioresistant cancers. On the other hand, radiation sensitizers enhanced the radiation effects in tumors by increasing the dose specifically to the tumor cells. Recently, the use of gold nanoparticles as potential tumor selective radio-sensitizers has been proposed as a breakthrough in radiotherapy with conventional radiations. The enhanced radiation effect of heavy ions in tumor by using gold nanoparticles as radio-sensitizer may provide alternative in hadron therapy. In this study, we investigated the radiosensitizing effects of carbon ions with a linear energy transfer of 70 keV/μm in the presence of 15 nm citrate-capped AuNPs. The existing of AuNPs resulted in 5.5-fold enhancement in hydroxyl radical production and 24.5% increment in relative biological effectiveness (RBE) values for carbon-ion-irradiated HeLa cells. The study indicated gold nanoparticles can be used as potential radio-sensitizer in carbon ions therapy.

On account of the biological harmfulness of hydrazine, we have designed and synthesized a novel red-emitting fluorescent probe (1) based on 3-hydroxyflavone. The probe could selectively and sensitively detect hydrazine over other primary amines, cations and anions. Moreover, we verified the mechanism of probe 1 for detecting hydrazine through a 1H NMR titration and MS spectral analysis. Importantly, the probe could selectively detect hydrazine in different water samples which showed its potential for practical applications.

The dexterous hands with high dexterity, high carrying capability, high precision and high task adaptability (multipurpose) are demanded in industry. This paper focuses on designing dexterous hands based on the parallel finger structures to improve above performances. Based on the motion property of human finger, the required motion types of the dexterous hands are proposed. The finger structures of RR-RPR and 2-UU-UPU are presented by structural evolution from the well-known PMs of parallelogram and 3-UU by means of group deduction, respectively. Two three-finger dexterous hands are designed by assembling the obtained parallel fingers on the palm in the same direction. The in-hand configurations are actually hybrid mechanisms, whose motion properties are analyzed by equivalent to the parallel mechanisms (PMs). The hands have high task adaptability that can perform the pinching operations both from the outside and inside the cavity of the objects. The kinematics of the fingers are presented to investigate the workspace performance, and the statics are analyzed to prove that the proposed parallel dexterous hands can provide desirable pinching force.

Most parallel mechanisms (PMs) encountered today have a common disadvantage, i.e., their low rotational capability. In order to develop PMs with high rotational capability, a family of novel manipulators with one or two dimensional rotations is proposed. The planar one-rotational one-translational (1R1T) and one-rotational two-translational (1R2T) PMs evolved from the crank-and-rocker mechanism (CRM) are presented by means of Lie group theory. A spatial 2R1T PM and a 2R parallel moving platform with bifurcated large-angle rotations are proposed by orthogonal combination of the RRRR limbs. According to the product principle of the displacement group theory, a hybrid 2R3T mechanism in possession of bifurcated motion is obtained by connecting the 2R parallel moving platform with a parallel part, which is constructed by four 3T1R kinematic chains. The presented manipulators possess high rotational capability. The proposed research enriches the family of spatial mechanisms and the construction method provides an instruction to design more complex mechanisms.

In this paper, a novel flame retardant (ACS) was prepared by crosslinking chitosan with bis-(4-formylphenyl)-phenyl-phosphonate (ABPO). ACS in association with ammonium polyphosphate (APP) and organic modified montmorillonite (OMMT) were used to prepare flame retardant thermoplastic polyurethane (TPU) composite through melt blending. For the TPU sample containing 10% flame retardants, the limiting oxygen index was increased from 20.8 to 29.0%, the vertical burning (UL-94) rating was upgraded from no rating to V-0, and the peak heat release rate was decreased from 1090 to 284 kW/m2. The thermal gravity analysis (TGA) indicated that ACS had excellent char formation ability and could greatly enhance the thermal stability of TPU. The tensile strength and elongation at break for flame retardant sample could reach 16.5 MPa and 1443% respectively.

The flammability and melt dripping of the widely used bio-based polyamide 11 (PA 11) have attracted much attention in the last decade, and they are still a big challenge for the fire science society. In this work, a novel single macromolecular intumescent flame retardant (AM-APP) that contains an acid source and a gas source was prepared by supramolecular reactions between melamine and p-aminobenzene sulfonic acid, followed by an ionic exchange with ammonium polyphosphate. The chemical structure of AM-APP was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. AM-APP and TiO2 were then introduced into PA 11 by melt compounding to improve the fire resistance of the composite. The fire performance of PA 11 composites was evaluated by the limiting oxygen index (LOI), vertical burning (UL-94), and cone calorimetry tests. The results showed that the presence of 22% AM-APP and 3% TiO2 increased the LOI value from 22.2 to 29.2%, upg...

This work reports our recent efforts on introducing chitosan (CS) in association with ammonium polyphosphate (APP) into polylactic acid (PLA) by melt blending to improve the flame retardancy of the biocomposites. The flammability of the composites was characterized by limiting oxygen index (LOI), UL-94 vertical burning test and cone calorimetry test (CONE). The results showed that the PLA sample containing 2% CS and 5% APP achieved the maximal LOI value of 33.1, passed the UL-94 V-0 rating, and decreased the peak heat release rate to 425.6 kW/m 2 . The morphology characterization of char residue by scanning electron microscope indicated a dense, homogeneous and continuous residue char could be formed by the presence of APP and CS in PLA. Fourier transform infrared spectroscopy and thermal gravity analysis suggested that CS could act as a novel carbon agent owning to its high content of carbon atoms and multi-hydroxyl groups, and the interaction between CS and APP could provide synergistic effects in improving the flame retardancy of PLA biocomposites. X-ray diffraction and differential scanning calorimetry results demonstrated that the presence of APP and CS could promote the crystallization of PLA.

Background and purpose Cell cycle phase could affect the cellular uptake of nanoparticles. Based on the fact that ionizing radiation exposure can delay cell cycle progression including inducing G2/M phase arrest, we propose that ionizing radiation exposure is a cell cycle phase-dependent targeting approach for intracellular delivery of nano-agents in tumor cells. Materials and methods We synthesized luminescent gold nanoclusters (AuNCs) using a one-pot green synthetic method. Subsequently, we used the as-prepared AuNCs as both “nano-agents” and fluorescent trafficking probes for our study using human cervical carcinoma HeLa cells. Estimating the cellular uptake of AuNCs and cell cycle analysis were performed following X-rays irradiation and cell synchronization. Results Our work showed that X-rays irradiation could delay the division of HeLa cells and thereby enhance the retention of AuNCs in HeLa cells, which is a reverse strategy compared with other studies on synergistic nano-radiotherapy. Our results demonstrated that the cell cycle synchronization influenced the cellular uptake processes of AuNCs, suggesting that dynamic cell cycle progression could affect the cellular uptake kinetics of AuNCs. Conclusion We consider that the radiation-induced cell division delay might provide a possible mechanism underlying the enhanced effect for the cellular uptake of AuNCs in irradiated HeLa cells.