Constructing Ultra-Strong SERS Tags in the Cellular Raman-Silent Region by Orthogonal Array Testing Strategy.

Surface-enhanced Raman spectroscopy (SERS) tags have the advantages of unique fingerprint vibration spectrum, ultranarrow spectral line widths, and weak photobleaching effect, showing great potential for bioimaging. However, SERS imaging is still hindered for further application due to its weak spontaneous Raman scattering, biomolecular signal interference, and long acquisition times. Here, we develop a novel SERS tag of the core (Au)-shell (N-doped graphene) structure (Au@NGs) with ultrastrong and stable Raman signal (2180 cm-1) in the cellular Raman-silent region (1800-2800 cm-1) through base-promoted oxidative decarboxylation of amino acids. Exploring the factors (metal salts, amino acids, catalysts, temperature, etc.) to obtain Au@NGs with the strongest Raman signal commonly requires more than 100,000 separate experiments, while that using an orthogonal array testing strategy is reduced to 56. The existence of deep charge transfer between the Au surface and C≡N-graphene is proved by theoretical calculations, which means the ultrastrong signal of Au@NGs is the joint effect of electromagnetic and chemical enhancement. The Au@NGs have a detection sensitivity down to a single-nanoparticle level, and high-speed and high-resolution cellular imaging (4453 pixels) is obtained within 10 s by global Raman imaging. The combination of Au@NGs-based tags with ultrastrong intrinsic Raman imaging capability and global imaging technology holds great promise for high-speed Raman imaging.

Biological characteristics of pregnancy in captive Yangtze finless porpoises revealed by urinary metabolomics†.

The Yangtze finless porpoises (Neophocaena asiaeorientalis a.) are an endemic and critically endangered species in China. Intensive captive breeding is essential for understanding the biology of critically endangered species, especially their pregnancy characteristics, knowledge of which is crucial for effective breeding management. Urine metabolomics can reveal metabolic differences, arising from physiological changes across pregnancy stages. Therefore, we used the urinary metabolomic technology, to explore urinary metabolite changes in pregnant Yangtze finless porpoises. A total of 2281 metabolites were identified in all samples, which including organic acids and derivatives (24.45%), organoheterocyclic compounds (20.23%), benzenoids (18.05%), organic oxygen compounds (7.73%), and phenylpropanoids and polyketides (6.48%). There were 164, 387, and 522 metabolites demonstrating differential abundance during early pregnancy, mid pregnancy, and late pregnancy, respectively, from the levels observed in nonpregnancy. The levels of pregnenolone, 17α-hydroxyprogesterone, and tetrahydrocortisone were significantly higher during all pregnancy stages, indicating their important roles in fetal development. The differential metabolites between nonpregnancy and pregnancy were mainly associated with amino acid and carbohydrate metabolism. Moreover, metabolic activity varied across pregnancy stages; steroid hormone biosynthesis was predominant in early pregnancy, and amino acid biosynthesis and carbohydrate metabolism were predominant in mid pregnancy and late pregnancy, respectively. Our results provide new insights into metabolic characteristics in the Yangtze finless porpoises' urine during pregnancy, and indicate that the differential levels of urine metabolites can determine pregnancy in Yangtze finless porpoises, providing valuable information for the husbandry and management of pregnant Yangtze finless porpoises in captivity.

Click to Self-immolation: A "Click" Functionalization Strategy towards Triggerable Self-Immolative Homopolymers and Block Copolymers.

Self-immolative polymers (SIPs) are a class of degradable macromolecules that undergo stimuli-triggered head-to-tail depolymerization. However, a general approach to readily end-functionalize SIP precursors for programmed degradation remains elusive, restricting access to complex, functional SIP-based materials. Here we present a "click to self-immolation" strategy based on aroyl azide-capped SIP precursors, enabling the facile construction of diverse SIPs with different trigger units through a Curtius rearrangement and alcohol/thiol-isocyanate "click" reaction. This strategy is also applied to polymer-polymer coupling to access fully depolymerizable block copolymer amphiphiles, even combining different SIP backbones. Our results demonstrate that the depolymerization can be actuated efficiently under physiologically-relevant conditions by the removal of the trigger units and ensuing self-immolation of the p-aminobenzyl carbonate linkage, indicating promise for controlled release applications involving nanoparticles and hydrogels.

Incorporating ecosystem services into functional zoning and adaptive management of natural protected areas as case study of the Shennongjia region in China.

Against the background of global climate change and anthropogenic interference, studying the spatial and temporal heterogeneity of ecosystem services in important ecological function regions and rationally dividing the functional zones will help to promote the construction of the natural protected areas system dominated by national parks. The Shennongjia Region is an important candidate for China's national parks and one of the key pilots. Integrating the InVEST model, Getis-Ord Gi* index, hotspot analysis, GeoDetector and K-means clustering algorithm, we measured five ecosystem services interactions and delineate the functional zones. The results show that the spatial and temporal evolution of various ecosystem services in the Shennongjia Region between 2000 and 2020 was significant. All ecosystem services showed a decreasing and then increasing trend, except for carbon storage, which slowly declined. The ecological status of the region is in the process of polarization, with the local environment showed a trend of continuous deterioration. Water yield-habitat quality and carbon storage-water purification showed synergistic relationships; soil conservation showed trade-offs with water yield, carbon storage and water purification over a wide spatial range. The interaction between land surface temperature and vegetation cover was the most significant dominant factor. Hot spots for the comprehensive ecosystem services index were mainly located in the central and southern parts of the Shennongjia region and four types of ecosystem service functional zones were identified accordingly. This study is of great significance for maximizing the benefits of ecosystem service functions, the efficient allocation of environmental resources and the rational formulation of management policies in natural protected areas.

Regulating the properties of XQ-2d for targeted delivery of therapeutic agents to pancreatic cancers.

Enhanced recognition ability, cell uptake capacity, and biostability are characteristics attributed to aptamer-based targeted anticancer agents, and are possibly associated with increased accumulation at the tumor site, improved therapeutic efficacy and reduced negative side effects. Herein, a phosphorothioate backbone modification strategy was applied to regulate the biomedical properties of pancreatic cancer cell-targeting aptamer for efficient in vivo drug delivery. Specifically, the CD71- targeting aptamer XQ-2d was modified into a fully thio-substituted aptamer S-XQ-2d, improving the plasma stability of S-XQ-2d and mitomycin C (MMC)-functionalized S-XQ-2d (MFSX), thus considerably prolonging their half-life in mice. Moreover, the binding and uptake capacities of S-XQ-2d were significantly enhanced. MFSX showed the same level of cytotoxicity as that of MMC against targeted cancer cells, but lower toxicity to non-targeted cells, highlighting its specificity and biosafety. Brief mechanistic studies demonstrated that XQ-2d and S-XQ-2d had different interaction modes and internalization pathways with the targeted cells.

Emerging Trends in the Chemistry of End-to-End Depolymerization.

Over the past couple of decades, polymers that depolymerize end-to-end upon cleavage of their backbone or activation of a terminal functional group, sometimes referred to as "self-immolative" polymers, have been attracting increasing attention. They are of growing interest in the context of enhancing polymer degradability but also in polymer recycling as they allow monomers to be regenerated in a controlled manner under mild conditions. Furthermore, they are highly promising for applications as smart materials due to their ability to provide an amplified response to a specific signal, as a single sensing event is translated into the generation of many small molecules through a cascade of reactions. From a chemistry perspective, end-to-end depolymerization relies on the principles of self-immolative linkers and polymer ceiling temperature (Tc). In this article, we will introduce the key chemical concepts and foundations of the field and then provide our perspective on recent exciting developments. For example, over the past few years, new depolymerizable backbones, including polyacetals, polydisulfides, polyesters, polythioesters, and polyalkenamers, have been developed, while modern approaches to depolymerize conventional backbones such as polymethacrylates have also been introduced. Progress has also been made on the topological evolution of depolymerizable systems, including the introduction of fully depolymerizable block copolymers, hyperbranched polymers, and polymer networks. Furthermore, precision sequence-defined oligomers have been synthesized and studied for data storage and encryption. Finally, our perspectives on future opportunities and challenges in the field will be discussed.

Insight into the pollution characteristics of road and roof runoff in Changsha, China.

Non-point source pollution from rainwater runoff presents a serious challenge for urban water management in many cities undergoing urbanization and experiencing climate change. To alleviate water resource conflicts in Changsha, China, this study comprehensively evaluated the pollution characteristics and first flush effect (FFE) of runoff from asphalt roads and colored steel plate roofs under seven rainfall events in April-May 2022. The runoff was collected and purified using bioretention ponds. The results showed that the peak runoff pollutant concentrations occurred within the first 20 min of runoff generation and then decreased to relatively stable levels, with maximum total suspended solids (TSS) concentration and chemical oxygen demand (CODCr) reaching 873.5 and 207.32 mg/L, respectively, for road runoff and 162 and 73.31 mg/L for roof runoff, respectively. The main pollutants were TSS and CODCr, followed by ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3--N), total phosphorus (TP), and nitrite nitrogen (NO2--N). Concentrations of pollutants and FFE for roof runoff were lower than those for road runoff. Road runoff had a more obvious FFE for TP and NH4+-N, whereas the roof runoff showed the presence of TP and NO3--N. An important implication is that treating the first 30% of surface runoff from rainfall events with long antecedent dry days or high rainfall amounts is necessary to improve water quality before discharge or utilization. The study also found that road and roof runoff, after treatment with bioretention ponds, exhibit good water quality, thus, allowing their use as reclaimed water or for miscellaneous purposes in urban areas. Overall, this study provides useful information for designing management measures to mitigate runoff pollution and reuse in Changsha.

Digital micelles of encoded polymeric amphiphiles for direct sequence reading and ex vivo label-free quantification.

Identification and quantification of synthetic polymers in complex biological milieu are crucial for delivery, sensing and scaffolding functions, but conventional techniques based on imaging probe labellings only afford qualitative results. Here we report modular construction of precise sequence-defined amphiphilic polymers that self-assemble into digital micelles with contour lengths strictly regulated by oligourethane sequences. Direct sequence reading is accomplished with matrix-assisted laser desorption/ionization (MALDI) tandem mass spectrometry, facilitated by high-affinity binding of alkali metal ions with poly(ethylene glycol) dendrons and selective cleavage of benzyl-carbamate linkages. A mixture of four types of digital micelles could be identified, sequence-decoded and quantified by MALDI and MALDI imaging at cellular, organ and tissue slice levels upon in vivo administration, enabling direct comparison of biological properties for each type of digital micelle in the same animal. The concept of digital micelles and encoded amphiphiles capable of direct sequencing and high-throughput label-free quantification could be exploited for next-generation precision nanomedicine designs (such as digital lipids) and protein corona studies.

Impact of body mass index on postoperative oxygenation impairment in patients with acute aortic syndrome.

Objective: Oxygenation impairment is a common complication of acute aortic syndrome (AAS) patients after surgical repair. The aim of this study is to identify the relationship between body mass index (BMI) and the risk of postoperative oxygenation impairment in AAS patients. Methods: A total of 227 consecutive patients who were diagnosed as AAS and underwent surgical repair were recruited. They were divided into two groups based on the postoperative oxygenation impairment (non-oxygenation impairment group and oxygenation impairment group). Logistic regression was conducted to evaluate the association between BMI and the risk of oxygenation impairment after surgery. Dose-response curve and subgroup analysis were used to test the reliability of the results of regression analysis. A meta-analysis was then performed to further confirm these results using Pubmed, Embase, and Web of Science databases. Results: For the retrospective study, a significant association was observed after adjusting for a series of variables. BMI was significantly correlated with postoperative oxygenation impairment in patients with AAS (OR, 95% CI, P: 1.27, 1.17-1.46, 0.001). Compared with the normal weight group (18.5 kg/m2 ≤ BMI <23.0 kg/m2), patients with excessive BMI were at a higher risk of oxygenation impairment for the overweight group (23.0 kg/m2 ≤ BMI <25 kg/m2) and obesity group (BMI ≥25 kg/m2) (OR, 95% CI, P: 4.96, 1.62-15.15, 0.005; 9.51, 3.06-29.57, <0.001). The dose-response curve showed that the risk of oxygenation impairment after surgery increased with the increased BMI. Besides, subgroup analysis showed that AAS patients who have an excess weight with a TNF-α ≥ 8.1 pg/ml carried an excess risk of postoperative oxygenation impairment. For the meta-analysis, the pooled result also indicated that AAS patients with high BMI had a significantly increased risk of oxygenation impairment after surgery (OR, 95% CI, P: 1.40, 1.18-1.66, 0.001). Conclusion: Excessive BMI was an independent risk factor for AAS with postoperative oxygenation impairment.

Insights into rapidly recovering the autotrophic nitrogen removal performance of single-stage partial nitritation-anammox systems: Reconstructing granular sludge and its functional microbes synergy.

Partial nitritation-anammox (PNA) deteriorates easily and is difficult to recover. After an airlift inner-circulation partition bioreactor was impacted by low NH4+-N wastewater containing organic matter, Nitrospira and Denitratisoma propagated rapidly, granular sludge disintegrated, and the total nitrogen removal efficiency (TNRE) decreased from 68.27 % to 5.97 %. This study used a unique strategy to recover deteriorated single-stage PNA systems and explored the mechanism of rapid performance recovery. The TNRE of the system recovered up to 61.77 % in 43 days. The high nitrogen loading rate and hydraulic shear force from the airlift caused the sludge in the reactor to granulate again. The microbial community structure recovered, with a decrease in the abundance of Nitrospira (0.05 %) and enrichment of Candidatus Brocadia (8.82 %). A favorable synergy among functional microbes in the reactor was thus re-established, promoting the rapid recovery of the nitrogen removal performance. This study provides a feasible recovery strategy for PNA processes.

A Comparative Study of Flavonoids and Carotenoids Revealed Metabolite Responses for Various Flower Colorations Between Nicotiana tabacum L. and Nicotiana rustica L.

Tobacco is a model plant for studying flower coloration. Flavonoids and carotenoids were reported to contribute to the flower color in many plants. We investigated the mechanism underlying flower color formation in tobacco by comparing the profiling flavonoids and carotenoids between various species Nicotiana tabacum L. and Nicotiana rustica L., as their flowers commonly presented red (pink) and yellow (orange), respectively. The metabolomes were conducted by UPLC-ESI-MS/MS system. The main findings were as follows: (1) A total of 31 flavonoids and 36 carotenoids were identified in all four cultivars involved in N. tabacum and N. rustica. (2) Flavonoids and carotenoids tended to concentrate in the red flowers (N. tabacum) and yellow flowers (N. rustica), respectively. (3) About eight flavonoids and 12 carotenoids were primarily screened out for metabolic biomarkers, such as the robust biomarker involving kaempferol-3-o-rut, quercetin-glu, rutin, lutein, and ß-carotene. This is the first research of systematic metabolome involving both flavonoids and carotenoids in tobacco flower coloration. The metabolic mechanism concluded that flavonoids and carotenoids mainly contributed to red (pink) and yellow (orange) colors of the tobacco flowers, respectively. Our finding will provide essential insights into characterizing species and modifying flower color in tobacco breeding through genetic improvement or regulation of featured metabolic synthesis.

Bacteriophage Lytic Enzyme P9ly as an Alternative Antibacterial Agent Against Antibiotic-Resistant Shigella dysenteriae and Staphylococcus aureus.

Developing new strategies to replace or supplement antibiotics to combat bacterial infection is a pressing task in the field of microbiological research. In this study, we report a lytic enzyme named P9ly deriving from the bacteriophage PSD9 that could infect multidrug-resistant Shigella. This enzyme was identified through whole-genome sequencing of PSD9. The results show that P9ly contains a conserved T4-like_lys domain and belongs to the phage lysozyme family. Recombinant P9ly obtained from protein purification presented biological activity and could digest bacterial cell walls (CW), resulting in the destruction of cell structure and leakage of intracellular components. Furthermore, P9ly exhibited bacteriolytic and bactericidal activity on different strains, especially multidrug-resistant Gram-negative Shigella dysenteriae and Gram-positive Staphylococcus aureus. Additionally, combined use of P9ly with ceftriaxone sodium (CRO) could decrease necessary dose of the antibiotic used and improve the antibacterial effect. In summary, under the current backdrop of extensive antibiotic usage and the continuous emergence of bacterial resistance, this study provides an insight into developing bacteriophage-based antibacterial agents against both Gram-negative and Gram-positive pathogens.

Spatial and temporal evolution of ecological vulnerability based on vulnerability scoring diagram model in Shennongjia, China.

Shennongjia is one of the most important ecological function areas and ecologically vulnerable zones in the world. With the rapid development of social economies, especially tourism, the ecological environment of Shennongjia has experienced profound changes. Exploring the characteristics and changing trends of ecological environment in Shennongjia will help to analyze the causes of the damage to the ecological environment, and build a vulnerability analysis framework with multi-scale, multi-element, multi-flow, and multi-circulation characteristics, which provides an effective research paradigm and analysis tool for the study of regional ecological vulnerability. With the support of RS and GIS technology, this study uses spatial principal component analysis (SPCA) and the vulnerability scoring diagram (VSD) model to comprehensively and quantitatively analyze the spatial and temporal evolution characteristics and driving forces of ecological vulnerability in Shennongjia from 1996 to 2018. The VSD model was selected to decompose the vulnerability into three components of "exposure-sensitivity-adaptation", and 16 indicators were selected to construct an ecological vulnerability evaluation system in Shennongjia, and the evaluation data were organized in a progressive and detailed way. (1) During the study period, the overall ecological vulnerability of Shennongjia is in a mild vulnerability level, exhibiting differentiation characteristics of high in the northeast and low in the southwest. High vulnerability zones are mainly distributed in the main towns and roads. (2) The risk of ecological vulnerability of the entire region presents the characteristics of continuous decline. (3) Land-use types, population density, and vegetation coverage are the main factors driving the evolution of ecological vulnerability. (4) A high level of coupling coordination exists between ecological vulnerability and landscape patterns. Analyses of the ecological vulnerability of Shennongjia shows that the entire region is in a mild vulnerability level. The extreme vulnerability risk of the ecological environment shows polarization. The evolution of ecological environment in Shennongjia is the result of the interaction between human activities and natural environment. This study offers an effective way to assess ecological vulnerability and provides some strategies and guidance for improving ecological security.

Self-immolative polyplexes for DNA delivery.

Nucleic acids have immense potential for the treatment and prevention of a wide range of diseases, but delivery vehicles are needed to assist with their entry into cells. Polycations can reversibly complex with nucleic acids via ionic interactions to form polyplexes and transport them into cells, but they are still hindered by the need to balance cytotoxicity and delivery effectiveness. In this work, we describe a new self-immolative polyglyoxylamide (PGAm) platform designed to address these challenges by complexing nucleic acids via multivalent interactions in the polymeric form and releasing them upon depolymerization. Nine PGAms were synthesized and characterized, with different end-caps and variable cationic pendent groups. The PGAms underwent depolymerization under mildly acidic conditions, with rates dependent on their pendent groups and end-caps. They complexed plasmid DNA, forming cationic nanoparticles, and released it upon depolymerization. Cytotoxicity assays of the PGAms and polyplexes in HEK 293T cells showed a decrease in toxicity following depolymerization, and all samples exhibited much lower toxicity than a commercial non-degradable linear polyethyleneimine (jetPEI) transfection agent. Transfection assays revealed that selected PGAms provided similar levels of reporter gene expression to jetPEI in vitro with a PGAm analogue of poly[2-(dimethylamino)ethyl methacrylate] having particularly interesting activity that was dependent on depolymerization, along with low cytotoxicity. Overall, these results indicate that end-to-end depolymerization of self-immolative polymers can provide a new and promising tool for nucleic acid delivery.

Effects of temperature and total solid content on biohydrogen production from dark fermentation of rice straw: Performance and microbial community characteristics.

Semi-continuous experiments were carried out in lab-scale continuous stirred tank reactors to evaluate the effects of fermentation temperature (37 ± 1 °C and 55 ± 1 °C) and total solids (TS) contents (3 %, 6 %, and 12 %) on biohydrogen production from the dark fermentations (DF) of rice straw (RS) and the total operation duration was 105 days. The experimental results show that biohydrogen production (0.46-63.60 mL/g VSadded) from the thermophilic (55 ± 1 °C) DF (TDF) was higher than the mesophilic (37 ± 1 °C) DF (MDF) (0.19-2.13 mL/g VSadded) at the three TS contents, and achieved the highest of 63.60 ± 2.98 mL/g VSadded at TS = 6 % in TDF. The pH, NH4+-N and total volatile fatty acid of fermentation liquids in the TDF were all higher than those in the MDF. The high abundance of lactic acid-producing bacteria resulted in low biohydrogen produced at TS = 3 %. Under the TDF with TS = 6 %, the highest abundance of hydrolytic bacteria (Ruminiclostridium 54.24 %) led to the highest biohydrogen production. The increase of TS content from 6 % to 12 % induced degradation pathway changes from biohydrogen production to methane production. This study demonstrated that butyric acid fermentation was the main pathway to produce biohydrogen from RS in both DFs.

Coordinating External and Built-In Triggers for Tunable Degradation of Polymeric Nanoparticles via Cycle Amplification.

The selective activation of nanovectors in pathological tissues is of crucial importance to achieve optimized therapeutic outcomes. However, conventional stimuli-responsive nanovectors lack sufficient sensitivity because of the slight difference between pathological and normal tissues. To this end, the development of nanovectors capable of responding to weak pathological stimuli is of increasing interest. Herein, we report the fabrication of amphiphilic polyurethane nanoparticles containing both external and built-in triggers. The activation of external triggers leads to the liberation of highly reactive primary amines, which subsequently activates the built-in triggers with the release of more primary amines in a positive feedback manner, thereby triggering the degradation of micellar nanoparticles in a cycle amplification model. The generality and versatility of the cycle amplification concept have been successfully verified using three different triggers including reductive milieu, light irradiation, and esterase. We demonstrate that these stimuli-responsive nanoparticles show self-propagating degradation performance even in the presence of trace amounts of external stimuli. Moreover, we confirm that the esterase-responsive nanoparticles can discriminate cancer cells from normal ones by amplifying the esterase stimulus that is overexpressed in cancer cells, thereby enabling the selective release of encapsulated payloads and killing cancer cells. This work presents a robust strategy to fabricate stimuli-responsive nanocarriers with highly sensitive property toward external stimuli, showing promising applications in cancer therapy with minimized side effects.

Enhancing autotrophic nitrogen removal with a novel dissolved oxygen-differentiated airlift internal circulation reactor: Long-term operational performance and microbial characteristics.

Autotrophic nitrogen removal (ANR) processes have not been widely applied in wastewater treatment due to their long start-up time and unstable performance. In this study, a novel dissolved oxygen-differentiated airlift internal circulation reactor was developed to enhance ANR from wastewater. During 200 days of continuous operation, the reactor start-up was achieved within 30 days; a high total nitrogen removal efficiency of 80% was achieved and stably maintained under an aeration rate of 0.90 L/min and hydraulic retention time of 6 h. Additionally, the color of sludge went from a light yellow to dark red, and the amount and size of the micro-granules increased obviously. Medium-sized (1.0-2.5 mm) micro-granules accounted for 72.4% on day 190. The specific anammox activity increased from 0.53 to 1.43 g-N/g-VSS/d, while the SNOA decreased from 0.93 to 0.08 g-N/g-VSS/d. Furthermore, the microbial analysis showed that the Nitrosomonas (4.2%) and Candidatus Brocadia (22.6%) were enriched and formed the micro-granules after the reactor's long-term operation. The results indicate that novel configuration realizes the partitioning of dissolved oxygen (DO), optimizes nitritation and anammox reactions, and accelerates biochemical reactions, thereby enhancing ANR performance. This study provides a practical alternative to enhance ANR performance and a scientific basis for the development and application of novel nitrogen removal reactors.

Inflammation-responsive delivery systems for the treatment of chronic inflammatory diseases.

Inflammation is the biological response of immune system to protect living organisms from injurious factors. However, excessive and uncontrolled inflammation is implicated in a variety of devastating chronic diseases including atherosclerosis, inflammatory bowel disease (IBD), and rheumatoid arthritis (RA). Improved understanding of inflammatory response has unveiled a rich assortment of anti-inflammatory therapeutics for the treatment and management of relevant chronic diseases. Notwithstanding these successes, clinical outcomes are variable among patients and serious adverse effects are often observed. Moreover, there exist some limitations for clinical anti-inflammatory therapeutics such as aqueous insolubility, low bioavailability, off-target effects, and poor accessibility to subcellular compartments. To address these challenges, the rational design of inflammation-specific drug delivery systems (DDSs) holds significant promise. Moreover, as compared to normal tissues, inflamed tissue-associated pathological milieu (e.g., oxidative stress, acidic pH, and overexpressed enzymes) provides vital biochemical stimuli for triggered delivery of anti-inflammatory agents in a spatiotemporally controlled manner. In this review, we summarize recent advances in the development of anti-inflammatory DDSs with built-in pathological inflammation-specific responsiveness for the treatment of chronic inflammatory diseases.

Remote sensing inversion and spatial variation of land surface temperature over mining areas of Jixi, Heilongjiang, China.

BACKGROUND: Jixi is a typical mining city in China that has undergone dramatic changes in its land-use pattern of mining areas over the development of its coal resources. The impacts of coal mining activities have greatly affected the regional land surface temperature and ecological system. METHODS: The Landsat 8 Operational Land Imager (OLI) data from 2015 and 2019 were used from the Jiguan, Didao, and Chengzihe District of Jixi in Heilongjiang, China as the study area. The calculations to determine the land-use classification, vegetation coverage, and land surface temperature (LST) were performed using ArcGIS10.5 and ENVI 5.3 software packages. A correlation analysis revealed the impact of land-use type, vegetation coverage, and coal mining activities on LSTs. RESULTS: The results show significant spatial differentiation in the LSTs of Jixi City. The LSTs for various land-use types were ranked from high to low as follows: mining land > construction land > grassland > cultivated land > forest land > water area. The LST was lower in areas with high vegetation coverage than in other areas. For every 0.1 increase in vegetation coverage, the LST is expected to drop by approximately 0.75 °C. An analysis of mining land patches indicates that the patch area of mining lands has a significant positive correlation with both the average and maximum patch temperatures. The average patch temperature shows a logarithmic increase with the growth of the patch area, and within 200,000 m2, the average patch temperature increases significantly. The maximum patch temperature shows a linear increase with the patch area growth, and for every 100,000 m2 increase in the patch area of mining lands, the maximum patch temperature increases by approximately 0.81 °C. The higher the average patch temperature of mining land, the higher the temperature in its buffer zone, and the greater its influence scope. This study provides a useful reference for exploring the warming effects caused by coal mining activities and the definition of its influence scope.

Controlled drug delivery with nanoassemblies of redox-responsive prodrug and polyprodrug amphiphiles.

Self-assembled nanostructures are highly promising for controlled delivery of therapeutic and diagnostic agents. However, for conventional drug delivery nanosystems, there exist some intrinsic limitations such as low drug-loading contents, premature and burst release, nanocarrier matrix-associated toxicity and immunogenicity, and poor shelf stability. To address these issues, the covalent integration of active drug molecules into prodrug and polyprodrug amphiphiles and fabrication of self-delivery nanomedicines via controlled molecular self-assembly have emerged as a new paradigm. Moreover, it is crucial to achieve on-demand and selective activation of prodrugs and polyprodrugs in a spatiotemporally controlled manner, thus considerably reducing the occurrence of systemic toxicities. In this context, dynamic variations of reductive/oxidative (redox) milieu across normal and pathological tissues, cells, and cytoplasmic compartments provide accessible biochemical stimuli for triggered release of intact drugs. In this review, we highlight recent progresses on emerging applications of redox-activatable nanostructures self-assembled from prodrug and polyprodrug amphiphiles.