Modulus watch: In situ determination of the gel modulus by timing the fluorescence color change.

The gel modulus, a key parameter for gel materials, is traditionally determined by cumbersome rheometer. Recently, probe technologies occur to meet the requirements of in situ determination. Till now, in situ and quantitatively testing of gel materials with unabridged structure informations still remains a challenge. Here, we provide a facile, in situ approach to determine the gel modulus, by timing the aggregation of a doped fluorescence probe. The probe shows green emission during aggregation and shifts to blue once it forms aggregates. The higher modulus of the gel, the longer probe's aggregation time. Furthermore, a quantitative correlation of gel modulus with the aggregation time is established. The in situ method not only facilitates the scientific researches in the field of gels, but also provides a new approach for spatiotemporal materials.

A true color palette: binary metastable photonic pigments.

Different from the traditional concept that binary photonic crystals can only reproduce mixed colors due to the simple superposition of the photonic band gaps, precisely addressable "true colors" obtained from volume fraction deviation of binary photonic crystals with metastable structures are reported here. Inspired by the mussels' adhesion and longhorn beetles' photonic scales, a binary metastable amorphous photonic crystal was obtained by enhancing the driving forces and customizing the surface roughness of building blocks to regulate the thermodynamic and dynamic factors simultaneously. By controlling the volume fraction of two building blocks, the tunable photonic bandgap varies linearly in the visible region. Furthermore, the "true violet" that cannot be obtained by conventional color mixing is reproduced with the particular ultraviolet characteristics of red photonic pigment's metastable structures, which complement the palette effect of "true colors". Meanwhile, due to the self-adhesion and post-modification of building blocks, the stability of photonic pigments is further improved. The binary photonic pigments not only solve the dilemma of mixed colors, but also realize the tunability and multiplicity of "true colors", offering a new choice for the color palette of the world.

An injectable double-crosslinking iodinated composite hydrogel as a potential radioprotective spacer with durable imaging function.

Prostate cancer is one of the leading causes of cancer incidence among males worldwide. Radiotherapy can achieve similar oncological outcomes to those of radical prostatectomy. One concern is, however, radiation damage to the rectum because of the extreme proximity between the two organs. Inserting a biomaterial to separate the prostate and rectum is a promising strategy, and an injectable hydrogel is regarded to be the preferred spacer after screening of various materials. Nevertheless, there exist shortcomings for the currently available injectable hydrogel that cannot fully meet the unique requirements in clinical practice. In this work, a novel injectable hydrogel spacer based on carboxymethyl chitosan (CMC), aldehyde guar gum (AG), and aldehyde iohexol (DHQ) with an imaging function is fabricated. Contrast agent DHQ is chemically attached to CMC-AG network to form a double-crosslinking network to obtain a controlled degradation rate and high strength as well as durable CT imaging function. The hydrogel is injected subcutaneously into rats, where rapid gelation occurs and it serves as a hydrogel spacer. During the month-long in vivo studies, the spacer exhibits remarkable radiation dose attenuation and sustainable imaging function, as well as excellent toxicity profiles. This novel hydrogel shows excellent potential in the protection of critical organs during prostate cancer radiotherapy.

[Effect of soil-transmitted helminthes control through mass deworming and latrine improvement].

OBJECTIVE: To evaluate the effect of soil-transmitted helminthes control through mass deworming and latrine improvement in rural areas. METHODS: The data including mass deworming (1998-2000) and latrine improvement (2001-2010) were collected, summarized and analyzed in Danyang City. The infection rate of the soil-transmitted helminthes was monitored annually by using Kato-Katz method from 2001 to 2010. In addition, 2 villages with the improved latrines strategy and one village without the strategy were selected for hygienic evaluation. RESULTS: Totally 1 130 000 person-times of mass deworming were carried out in Danyang City from 1998 to 2000, and the infection rate of soil transmitted helminthes of human was decreased from 40.82% to 1.10%. The infection rate (2.49%-4.81%) was bounced in the first five years (from 2001 to 2005) after mass deworming, while it gradually declined in the following five years (from 2006 to 2010) and maintained at a low level (0.07%-0.52%), and there was a significant difference between the average infection rates during the above two stages (χ2 = 353.83, P < 0.01). There was a negative correlation between the coverage rate of harmless latrine and the infection rate (r = -0.83, P < 0.01). CONCLUSION: The mass deworming and latrine improvement are effective measures for the control of soil-trans-mitted helminthes infection in rural areas.