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The Yangtze River Delta is one of the most economically developed regions on the eastern coast of China. However, a local imbalance currently exists between its water resource environment and economic and social development due to its rapid urbanization. Thus, the reasonable evaluation and protection of local water resources are necessary. This study explores the northern Yangtze Delta, which is a more developed water system, as a pilot area. The temporal and spatial variation characteristics of rainfall and evaporation and their influencing factors were analyzed on the basis of 29 surface water sampling points, 16 rainfall stations, and three evaporation stations in the field from 1956 to 2019. Accordingly, the overall water supply quality of the river basin, the availability of different water resources, and the application of evaluation methods were assessed. Results show that local precipitation and evaporation are characterized by uneven spatial and temporal distributions in local areas, which, in turn, leads to the uneven temporal distribution of runoff, increasing the imbalance between the availability and demand of the limited local water resources. Nevertheless, the overall performance of local water quality is good. Surface water quality is mostly Ⅱ to Ⅲ, and locally Ⅳ. Most noncompliant months are during the non-flood season, and all values exceed the standard permanganate index. Groundwater is Class III or better, and the hydrochemistry type is predominantly calcium bicarbonate, sodium bicarbonate, and magnesium bicarbonate. By exploring the evaluation model of the Yangtze River Delta watershed characteristics, this study aims to provide a helpful reference for extending water resource evaluation in the Yangtze River Delta. Accordingly, this study can promote the sustainable development of the economic and social sectors of the Yangtze River Delta and the construction of its ecological environment.

Recently, sustained release vectors, especially cyclodextrin (CD) based supramolecular carriers, have been reported to play an important role and have spurred interesting developments as novel gene delivery systems. This review will summarize the recent designs of CD-based supramolecular structures as sustained gene release systems in terms of CD-based graft copolymers, polyrotaxanes or polypseudorotaxanes, and supramolecular hydrogels; the advantages of these CD-based supramolecular carriers in terms of biocompatibility, gene transfection ability and controllable release rate by tuning the de-threading of CDs; and the applications of these CD-based supramolecular sustained gene release systems in disease treatments by taking advantage of their increase of the therapeutic gene's treatment period, thereby improving the gene transfection efficiency and avoiding repeated administration to increase patient compliance. Last but not least, the further endeavour towards CD-based supramolecular structures as more precise sustained gene release systems will also be discussed.

Even though fungal keratitis is a severe corneal disease that can lead to permanent vision loss, its therapeutic management is still problematic. This limitation is in part attributable to the fact that tear film renewal curtails exposure time of drug containing eye drops to the ocular surface. Accordingly, anti-microbial therapy needs to be performed repeatedly. Efforts to resolve this hindrance include developing formulations that prolong drug retention on the ocular surface which can in turn improve therapeutic efficacy as well as reduce administration frequency. To extend drug residence time on the ocular surface, we designed a novel organic-inorganic hybrid consisting of a PEG-PPG copolymer modified with polyhedral oligomeric silsesquioxane (POSS) groups. Its tailored POSS-micelles possess both good biocompatibility and bio-adhesiveness, which improve ocular delivery of poorly soluble drugs. We describe here use of mouse fungal keratitis model to determine the effects of this formulation encapsulating amphotericin B (AMB) on this condition. The results show that POSS-micelles significantly prolonged AMB retention time on the ocular surface, leading to improved resolution of this disease. Moreover, this treatment strategy had no toxic effects during ocular administration either in vitro or in vivo. Therefore, this POSS formulation bearing AMB has the potential to prolong drug retention time and improve its therapeutic efficacy in managing fungal keratitis.

Rational design of new wound dressing materials aims to accelerate wound healing. Traditional hydrophilic wound dressings, however, tend to cause retention of wound exudate retention, which increases the risk of bacterial infection, resulting in slower wound healing. Herein, a multifunctional amphiphilic wound dressing nanofibrous materials with Janus superhydrophilic/ superhydrophobic feature is designed to accelerate wound healing. In this design, the top superhydrophilic polycaprolactone (PCL)-Gelatin (PCL-Gelatin, WCA ~ 0°) fibers function as a pump-like suction layer that can effectively isolate wound exudate from the wound site, thereby providing drier condition which lowers the risk of wound infection. More importantly, the superhydrophobic PCL-poly(perfluorodecyl methacrylate)-block-poly(dimethylsiloxane)-block-poly(perfluorodecyl methacrylate) (PFMA-b-PDMS-b-PFMA) (PCL-PFMA, WCA ~ 140°) in contact with the wound site showed excellent anti-adhesion effect to bacterial, cells and tissues, thereby further lowering the risk of bacterial infection and preventing the secondary injuries caused by dressing changes. Sprague-Dawley (SD) rat skin lesion model demonstrated significant improvement in wound healing of the Janus amphipathic PCL-Gelatin / PCL-PFMA fiber films compared with the conventional hydrophilic- and hydrophobic-only wound dressing materials. After 14 days of treatment, the wound healing area in this group was close to 100%. To the best our acknowledge, this is a pioneer exploration of Janus amphipathic wound dressing with unidirectional drainage function and anti-adhesive ability, which may have great potential for real life usage on clinical patients.

An amphiphilic star-shaped copolymer β-CD-g-PCL-SS-PEG-FA, consisting of a β-cyclodextrin (β-CD) core as well as grafted with bioreducible disulfide linkage in PCL-SS-PEG multiarms and targeting folic acid (FA) as end moiety, is designed with unimolecular micelles formation ability for targeted transport of chemotherapeutics to drug resistant tumor cells. Firstly, β-CD was utilized as core to growth PCL arms by ring-opening polymerization (ROP) of ε-CL, before disulfide terminal group transformation to render β-CD-g-PCL-SS-COOH. Secondly, α-hydroxy-ω-amine protected PEG (HO-PEG-NHBoc) was connected to β-CD-g-PCL-SS-COOH to obtain amphiphilic β-CD-g-PCL-SS-PEG, where PCL and PEG were connected via bioreducible disulfide bond. After deprotection of -Boc group, FA was introduced onto the distal end of block arms to obtain the desired β-CD-g-PCL-SS-PEG-FA copolymer. Because of highly branched core-shell amphiphilic structures, β-CD-g-PCL-SS-PEG-FA could act as unimolecular micelles. Interestingly, this unimolecular micelle could release the encapsulated drug in a glutathione (GSH) dependent manner due to disulfide linkage. More importantly, this unimolecular micelle could load doxorubicin (DOX) to promote its cellular uptake in multidrug resistance (MDR) protein overexpression tumor cells, by taking the advantage of FA targeting group and intracellular high GSH level in cancer cells. Together with satisfactory biocompatibility, this novel star-like β-CD-g-PCL-SS-PEG-FA unimolecular micelle could potentially be utilized as targeting nanocarriers in drug resistant cancer therapy.

The requirements in the design of railgun are analyzed in connection with the working states including the action integral and armature speed of the railgun. Based on rated bore and current, the inductance gradient can be indirectly calculated by the way of calculating the maximum electromagnetic force by Ansoft software, and then the launching efficiency will be increased indirectly by optimizing the height and width of railway and improving the inductance gradient of railgun to get a maximum electromagnetic force.