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Multifunctional nanomaterials with diagnostic and therapeutic capabilities offer promising customized nanomedicines for cancers. However, achieving good execution of these functions in vivo employing a single nanoframework remains challenging, and only a few of these magnetic nanocarriers have been validated for clinical use. In this study, based on biocompatibility and remarkable multifunctionalities, we describe a novel approach to synthesize small Fe3O4 nanoparticles conjugated with natural polysaccharide pectin and assembled into a pH-responsive T1-weighted magnetic resonance imaging contrast agent, Fe3O4@PD, for better chemotherapeutic efficacy. In vitro studies revealed that the conjugated doxorubicin (DOX) was quickly released in the tumor microenvironment by cleavage of the acid-sensitive acylhydrazone bond at a release rate of 89.72% and exerted a considerable inhibitory effect on breast cancer cells. In vivoT1-weighted images of mice showed that Fe3O4@PD displayed darkening to brightening contrast enhancement at tumor sites, and the relative signal-to-noise ratio of the tumor site reached its maximum (increased to about 2.27-fold) for distinguishing the normal and tumor tissues. Thus, this Fe3O4@PD-based system has the potential to be a multifunctional nanodrug delivery system, and as a smart theragnostic platform, it has broad application prospects in clinical and biological works, such as cell-based diagnostics and in vivo medication monitoring. [ABSTRACT FROM AUTHOR]

Coherent multiwave mixing is in demand for optical frequency conversion, imaging, quantum information science, etc., but has rarely been demonstrated in solid-state systems. Here, we observed three- and five-wave mixing (5WM) in a c -axis growth zinc oxide microwire on a Au film with picosecond pulses in the near-infrared region. An output 5WM of 4.7 × 10 -7 μW, only 2-3 orders smaller than the three-wave mixing, is achieved when the excitation power is as low as 1.5 mW and the peak power density as weak as ∼10 7 W/cm 2 . The excitation power dependence of 5WM agrees well with the perturbation limit under the low intensity but exhibits a strong deviation at a high pumping power. This extraordinary behavior is attributed to the cooperative resonant enhancement effect when pumping in the near-infrared range. Our study offers a potential solid-state platform for on-chip multiwave mixing and quantum nonlinear optics, such as generating many-photon entangled states or the construction of photon-photon quantum logic gates.

Poly(lactide- co -glycolide) (PLGA) has been widely used as a scaffold material for tissue engineering owing to its biocompatibility, biodegradability, and biosafety. However, lactic acid (LA) produced during PLGA degradation is prone to inflammation, which is a shortcoming that must be avoided. To this end, crystalline PLGA-PEG was synthesized here for the first time. To make the crystalline PLGA-PEG more suitable for tissue engineering, porous crystalline PLGA-PEG was prepared via the swelling behavior during recrystallization annealing. The structure and properties of the porous crystalline PLGA-PEG were confirmed by SEM, POM, and XRD. Furthermore, the swelling behavior of different PEG molecular weights was studied, and the cell viability test and alkaline phosphatase activity test showed that PLGA-PEG has good biocompatibility. Such a porous crystalline PLGA-PEG will make PLGA have a broader application prospect in bone repair.

Developing a high-performance nonprecious metal electrocatalyst for water splitting is a strong demand for the large-scale application of electrochemical H 2 production. In this work, we design a facile and scalable strategy to activate titanium metal for the hydrogen evolution reaction (HER) in alkaline media through incorporating hydrogen into the α-Ti crystal lattice by H 2 plasma bombardment. Benefiting from the accelerated charge transfer and enlarged electrochemical surface area after H 2 plasma treatment, the H-incorporated Ti shows remarkably enhanced HER activity with a much lower overpotential at -10 mA cm -2 by 276 mV when compared to the pristine Ti. It is revealed that the retention of the incorporated H(D) atoms in the Ti crystal lattice during HER accounts for the durable feature of the catalyst. Density functional theory calculations demonstrate the effectiveness of hydrogen incorporation in tuning the adsorption energy of reaction species via charge redistribution. Our work offers a novel route to activate titanium or other metals by H incorporation through a controllable H 2 plasma treatment to tune the electronic structure for water splitting reactions.

Cell-adhesive properties are of great significance to materials serving as extracellular matrix mimics. Appropriate cell-adhesive property of material interface can balance the cell-matrix interaction and cell-cell interaction and can promote cells to form 3D structures. Herein, a novel magnetic polyacrylamide (PAM) hydrogel fabricated via combining magnetostatic field induced magnetic nanoparticles assembly and hydrogel gelation was applied as a multicellular spheroids culturing platform. When cultured on the cell-adhesive microarray interface of sliced magnetic hydrogel, normal and tumor cells from different cell lines could rapidly form multicellular spheroids spontaneously. Furthermore, cells which could only form loose cell aggregates in a classic 3D cell culture model (such as hanging drop system) were able to be promoted to form multicellular spheroids on this platform. In the light of its simplicity in fabricating as well as its effectiveness in promoting formation of multicellular spheroids which was considered as a prevailing tool in the study of the microenvironmental regulation of tumor cell physiology and therapeutic problems, this composite material holds promise in anticancer drugs or hyperthermia therapy evaluation in vitro in the future.

For mimicking the fibrous extracellular matrix (ECM), a facile method for patterning anticell adhesive substrate was novelly applied on agarose hydrogel. Without using masks or templates for etching, we applied the magnetic field-induced colloidal assembly of magnetic nanoparticles on the flat agarose hydrogel to form cell-adhesive micropatterns. Meanwhile, tuning the hydrogel substrate's modulus to fit real tissue was experimentally demonstrated. Magnetic nanobeads were also assembled on this hydrogel surface and formed more complete and regular patterns. The patterned hydrogel substrate could actually influence behaviors of different cancer cells, including adhesion, growth, and migration.

Mercury emissions in China have increased by 164% during 1992-2007. While major mercury producers were among energy combustion and nonferrous metal sectors, little is known for the socioeconomic factors driving the growth of emissions. In this paper we examine the underlying drivers and their contributions to the change of mercury emissions. Results show that changes in per capita GDP and GDP composition led to increased emissions which offset the reduction of emissions made possible by technology-induced decrease of mercury emissions intensity and changes in final demand mix. In particular, changes in final demand mix caused decreasing mercury emissions from 1992 to 2002 and increasing emissions from 2002 to 2007. Formation of fixed capital was the dominant driver behind the increase of mercury emissions, followed by the increasing urban population and net exports. This systems-based examination of socioeconomic drivers for China's mercury emission increase is critical for emission control by guiding policy-making and targets of technology development.

Breath figure (BF) process is a facile method to prepare honeycomb structures by dynamic movements of condensed micrometer-sized water droplets at the interface of volatile fluid. Here, we aim to find answers to understand how the BF process occurs on micropipettes with curvature gradient and to understand the role of the surfactant in obtaining honeycomb patterns. Poly (L-lactic acid) (PLLA) chloroform solution with dioleoylphosphatidylethanolamine (DOPE) as surfactant was utilized. It is found that the honeycomb structure formed on the micropipettes changes remarkably with the gradually increased surface curvature. The variation trends of the arrangement and diameter of pores on the micropipettes with the increasing curvature are similar to the different time stages of BF process: smaller and sparse pores formed at higher curvature are similar to those formed at early stage of BF; regular honeycomb patterns formed at lower curvature are similar to those formed at the late stage of BF. Especially, the "semi-coalescence" hemispherical pores strings are found at high curvatures on PLLA-DOPE films, indicating the surfactant-induced coalescence of water droplets in BF process. The differences of drying speed of polymer solvent on micropipette with gradually increased curvatures make the printing of the pores at different BF stages on polymer film possible. These findings not only strongly support the mechanism of BF array formation, but also elucidate the surfactant-induced coalescence.

Crop residues are a critical component of the sustainable energy and natural resource strategy within a country. In this study, we use hybrid life-cycle environmental and economic analyses to evaluate and compare the atmospheric chemical, climatic, ecological, and economic issues associated with a set of energy conversion technologies that use crop residues for various energy demands in China. Our analysis combines conventional process-based life cycle assessment with economic input-output life cycle assessment. The results show that the return of crop residues to the fields, silo/amination and anaerobic digestion (household scale) offer the greatest ecological benefits, with net greenhouse gas reduction costs of US$3.1/tC, US$11.5/tC, and US$14.9/tC, respectively. However, if a positive net income for market-oriented operations is the overriding criterion for technology selection, the cofiring of crop residues with coal and crop residue gasification for power generation offer greater economic scope and technical feasibility, with net incomes of US$4.4/Mg and US$4.9/Mg, respectively. We identify that poor economies of scale and the absence of key technologies mean that enterprises that use pure combustion for power generation (US$212/tC), gasification for heat generation (US$366/tC) and large-scale anaerobic digestion for power generation (US$169/tC) or heat generation (US$206/tC) are all prone to operational deficits. In the near term, the Chinese government should also be cautious about any large-scale investment in bioethanol derived from crop residues because, with a carbon price of as high as US$748/tC, bioethanol is the most expensive of all energy conversion technologies in China.

In the present study, we introduced Ag nanoparticles into polymer and found for the first time that Ag nanoparticles can induce the formation of breath figure (BF) arrays on polymer surfaces. The effect of Ag nanoparticles has a balance with the BF process, which is influenced by humidity levels and polymers. These nanoparticle-induced BF process involves an interesting interaction between two self-assembly processes on different length scales. The aggregation of Ag nanoparticles on the water/polymer interface might be the key to their inducing ability. Hence, the interfacial-active Ag nanoparticles can be utilized to widen the applications of the BF method and to fabricate a wide variety of novel functionalized porous polymer films.

Current patterns and future possibilities of China's material metabolism are evaluated from perspectives of consumption structure change and technology development using the approach of input-output modeling to integrate ecological and economic systems. A physical input monetary output (PIMO) model is created and is applied to the Chinese economy with 43 sectors and 25 material categories. A set of scenarios, five exploring aspects of consumption structure change and three doing the same for technology development, is analyzed to quantitatively predict China's future possible material metabolism patterns in 2010. The results provide a foundation for quantitative studies of resource consumption and waste generation in China, which given its increasing pivotal role in manufacturing is also helpful for research on the material metabolism of the entire world.

A study on the isothermal crystallization kinetics of aqueous solution of poly (vinyl methyl ether) (PVME) was carried out by Fourier transform infrared (FTIR) and optical microscopy respectively. IR spectra of PVME solution were measured as a function of time under the isothermal crystallization conditions. With the process of crystallization, the phase of solution changes from transparent state to opaque one within around 1-2 min for 40 or 45 wt % PVME sample, the C-H symmetric stretching bands (nus(CH3)) shift to lower wave number 2823 cm(-1). The red shift of nus(CH3) absorption band was not observed in the transparent noncrystallization area. Using the temperature jump method, we determined the growth rate of ice crystal between the glass transition temperature Tg and the melting temperature Tm. At the different crystallization temperatures Tc, the different morphologies and dimension of ice crystal are also observed.