Landsat observations of total suspended solids concentrations in the Pearl River Estuary, China, over the past 36 years.

Information on long-term trends in total suspended solids (TSS) is critical for assessing aquatic ecosystems. However, the long-term patterns of TSS concentration (CTSS) and its latent drivers have not been well investigated. In this study, we developed and validated three semi-analysis algorithms for deriving CTSS using Landsat images. Subsequently, the long-term trends in CTSS in the Pearl River Estuary (PRE) from 1987 to 2022 and the driving factors were clarified. The developed algorithms yielded excellent performance in estimating CTSS, with mean absolute percentage errors <25% and root mean square errors of <13 mg/L. Long-term Landsat observations showed an overall decreasing trend and significant spatiotemporal dynamics of the CTSS in the PRE from 1987 to 2022. The analysis of driving factors suggested that industrial sewage, cropland, forests and grasslands, and built-up land were the four potential driving forces that explained 87.81% of the long-term variation in CTSS. This study not only provides 36-year recorded datasets of CTSS in estuary water, but also offers new insights into the complex mechanisms that regulate CTSS spatiotemporal dynamics for water resource management.

Ferrocene crosslinked and functionalized chitosan microspheres towards bio-based Fenton-like system for the removal of organic pollutants.

Dye-containing wastewater treatment has been a major long-term global challenge. For this purpose, a novel bio-based microspheres (CS-FC) with high specific surface area (63.24 m2·g-1) and nano-channels (17.95 nm) was prepared using chitosan as the framework and ferrocene as a crosslinking active group. CS-FC not only has the ability to rapidly enrich methyl orange (MO) through hydrogen-bonding and electrostatic attraction, but also almost completely degrades it in the presence of H2O2/K2S2O8 through a synergistic radical/non-radical mechanism under the activating effect of ferrocene. Without H2O2/K2S2O8, the maximum MO adsorption capacity of CS-FC is in the range 871-1050 mg·g-1, and conforms to a Langmuir isothermal model with pseudo-second-order kinetics. In the presence of H2O2/K2S2O8, the removal of MO dramatically increased from 32 % to nearly 100 % after incubation for 60 min, due to the simultaneous formation of highly reactive 1O2 and ·OH. The significant contribution from 1O2 endowed CS-FC/H2O2/K2S2O8 with high universality for degrading various organic pollutants (including azo dyes and antibiotics), a wide pH window (2-8), and low sensitivity to co-existing ions. Such cost-effective, recyclable porous bio-based microspheres are suitable for heterogeneous Fenton-like catalysis in organic wastewater treatment that rely on synergistic radical/non-radical reaction pathways.

Redox-responsive microemulsion: Fabrication and application to curcumin encapsulation.

HYPOTHESIS: Stimulus-responsive microemulsions have aroused significant attention because of their versatile and reversible switchability between stable and unstable states. However, most stimuli-responsive microemulsions are based on stimuli-responsive surfactants. We posit that the change in the hydrophilicity of a selenium-containing alcohol triggered by a mild redox reaction could also influence the stability of microemulsions and provide a new nanoplatform for the delivery of bioactive substances. EXPERIMENTS: A selenium-containing diol (3,3'-selenobis(propan-1-ol), PSeP) was designed and used as a co-surfactant in a microemulsion with ethoxylated hydrogenated castor oil (HCO40), diethylene glycol monohexyl ether (DGME), 2-n-octyl-1-dodecanol (ODD) and water. The redox-induced transition in PSeP was characterized by 1H NMR, 77Se NMR, and MS. The redox-responsiveness of the ODD/HCO40/DGME/PSeP/water microemulsion was investigated through determination of a pseudo-ternary phase diagram, analysis by dynamic light scattering, and electrical conductivity, and its encapsulation performance was evaluated by determination of the solubility, stability, antioxidant activity, and skin penetrability of encapsulated curcumin. FINDINGS: The redox conversion of PSeP enabled efficient switching of ODD/HCO40/DGME/PSeP/water microemulsions. Addition of oxidant (H2O2), oxidized PSeP into more hydrophilic PSeP-Ox (selenoxide), disrupting the emulsifying capacity of the combination of HCO40/DGME/PSeP, markedly reducing the monophasic microemulsion region in the phase diagram, and inducing phase separation in some formulations. Addition of reductant (N2H4·H2O), reduced PSeP-Ox and restored the emulsifying capacity of the combination of HCO40/DGME/PSeP. In addition, PSeP-based microemulsions can significantly enhance the solubility in oil (by 23 times), stability, antioxidant capacity (DPPH∙ radical scavenging by 91.74 %), and skin penetrability of curcumin, showing clear potential for encapsulation and delivery of curcumin and other bioactive substances.

Simultaneous inversion of concentrations of POC and its endmembers in lakes: A novel remote sensing strategy.

Data on the concentration of particulate organic carbon (POC) and its endmembers provide a basis for the characterisation of lake biogeochemical cycles. Here, a novel remote sensing strategy (the SCPOC algorithm) was developed to determine total POC concentrations, as well as terrestrial and endogenous POC concentrations in lakes. This strategy provides a successful example for the combination of isotope tracer and remote sensing technology. First, we obtained the terrestrial and endogenous POC concentration at the sampling point based on isotope tracing technology. Afterwards, we established a relationship between the phytoplankton absorption coefficient and the endogenous POC concentration (Cend), and applied a semi-analytical algorithm to invert the Cend value. Finally, the POC source ratio model and Cend value were combined to obtain the POC concentration (CPOC) and terrestrial POC (Cter). The results of synchronisation verification based on ocean and land colour instrument (OLCI) images show that the SCPOC algorithm has high Cend, Cter, and CPOC inversion accuracy, with MAPE values of 26.07%, 30.43%, and 42.28%, respectively. In fact, the SCPOC algorithm not only improved the accuracy of lake POC mapping, but also fills the gap of optical retrieval of POC endmember concentrations. Additionally, data from the OLCI images indicated that the studied lakes were dominated by external POC. However, because of the greater contribution of algal blooms to POC, this dominant advantage weakens in summer, although the terrestrial organic carbon carried by rainfall runoff also affects lake POC composition. Different POC sources have different ecological roles in lakes, and the superior POC end-element estimation capability of the SCPOC algorithm can not only be used as a supplement to traditional tracing methods, but also provides accurate spatial data for lake management.

Characteristics of the chromophoric dissolved organic matter of urban black-odor rivers using fluorescence and UV-visible spectroscopy.

Urban black-odor water (BOW) is a typical phenomenon seen in the urban water environment; it is caused by excessive pollution by organic matter and other pollutants, such as nitrogen and phosphorous. Chromophoric dissolved organic matter (CDOM) is a major optical fraction of dissolved organic matter. In this study, optical properties and components of CDOM were obtained from 178 river samples collected from five cities in China, the sample were investigated using absorption and fluorescence spectroscopy. The collected included 89 ordinary water (OW) samples, 63 mild BOW (MBOW), and 26 heavy BOW (HBOW) samples. Significant differences were found in the absorption spectra of the HBOW, MBOW, and OW samples, particularly in their optical parameters (the slope of the spectrum (S275-295), and the ratio of two absorption coefficients of CDOM (E2:E3)). Additionally, the fluorescence intensity of the humic acid-like component (F5) and soluble microbial by product-like component (F4) obtained via the fluorescence regional integration (FRI) method were 3 and 4.2 times higher in HBOW than in OW, respectively; this could be used as an indicator to distinguish OW from BOW in urban rivers. The results obtained using the redundancy method and the strong negative correlation between F4 and dissolved oxygen (DO) (r = - 0.56) suggested that the composition of CDOM could change significantly under different urban water environments (p < 0.01). Different correlations were also found between F5, and a355, E2:E3, S275-295 in different BOW levels, suggesting that the optical parameters of CDOM were mainly determined by the polluted organic matter originating from terrestrial sources with large molecular humic acid-like compounds; optical parameter a355 could distinguish BOW from OW. These findings are conducive in understanding the dynamics of organic matter pollution and to discover the composition and optical properties of the CDOM in urban BOW and OW, thereby providing an effective method for tracking the spatial characteristics of BOW in urban rivers using remote sensing technologies in areas with multiple sources of pollution.

Tuning CO2-induced reversible redispersion or irreversible destabilisation for latex separation.

HYPOTHESIS: The CO2-sensitive dispersion/precipitation transition of polymer latexes fabricated based on a responsive emulsifier is a promising way to conveniently acquire bulk polymer materials. Nevertheless, the tedious synthesis procedures for switchable surfactants and the harsh operating requirements for the sensitive latexes constrain the applicability of the approach for latex preparation. Therefore, a new strategy for generating latexes with tunable CO2 responsiveness in a maneuverable way is urgently needed. EXPERIMENTS: In this work, a CO2-switchable electrostatic interaction is introduced to construct responsive latexes. A series of lightly crosslinked poly(diethylaminoethyl methacrylate-styrene) [P(DEA-St)] latexes with different PDEA contents were fabricated via one-pot emulsion copolymerization, with divinylbenzene and sodium dodecylsulfate (SDS) used as the crosslinker and anionic emulsifier, respectively. The influence of the DEA feeding ratio on the resulting P(DEA-St) colloids was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Then, a cyclic CO2/N2 input was introduced to verify the response transitions of polymer latexes. FINDINGS: Accompanied by the stepwise decrease of DEA feeding ratio, the morphology of the resulting copolymerized nanoparticles changed from an ambiguous bulge to the typical spherical pattern. In addition, the P(DEA-St) latexes treated by cyclic CO2/N2 exhibit four different types of response modes, namely (i) CO2-switchable swelling/deswelling transition, (ii) CO2-reversible dispersion/coagulation transition, (iii) CO2-induced irreversible destabilisation and (iv) CO2-insensitive latexes. The CO2-responsive destabilisation is highly applicable in the separation and transportation fields of commercial latex products, such as poly(methyl methacrylate), poly(n-butyl acrylate) and poly(butyl methacrylate) colloids.

Percutaneous Microwave Ablation versus Laparoscopic Partial Nephrectomy for cT1a Renal Cell Carcinoma: A Propensity-matched Cohort Study of 1955 Patients.

Background Percutaneous microwave ablation (MWA) and laparoscopic partial nephrectomy (LPN) are two modalities indicated for early-stage renal cell carcinoma (RCC) with low extent of invasion. Purpose To compare the long-term results of percutaneous MWA and LPN in the treatment of cT1a RCC. Materials and Methods This retrospective study included 1955 patients with cT1a RCC treated with percutaneous MWA or LPN between April 2006 and November 2017. Propensity score matching was used. Oncologic outcomes were analyzed by using the Fine-and-Gray competing risk models. Results A total of 185 patients underwent percutaneous MWA (mean age, 63.2 years ± 15.2 [standard deviation]) and 1770 underwent LPN (mean age, 50.9 years ± 13.2). During the follow-up (median, 40.6 months), after propensity score matching, no difference was observed between local tumor progression (3.2% vs 0.5%, P = .10), cancer-specific survival (2.2% vs 3.8%, P = .24), and distant metastases (4.3% vs 4.3%, P = .76). Patients who underwent percutaneous MWA had worse overall survival (hazard ratio, 2.4; 95% confidence interval: 1.0, 5.7; P = .049 vs LPN) and disease-free survival (82.9% vs 91.4%, P = .003). Percutaneous MWA led to smaller drop in estimated glomerular filtration rate at discharge (6.2% vs 16.4%, P < .001), smaller estimated blood loss (4.5 mL ± 1.3 vs 54.2 mL ± 69.2), lower cost ($3150 ± 2970 vs $6045 ± 1860 U.S. dollars), shorter operative time (0.5 minute ± 0.1 vs 1.8 minutes ± 0.6), and shorter postoperative hospitalization time (5.1 days ± 2.6 vs 6.9 days ± 2.8) (all P < .001 vs LPN). There were fewer cases of fever in the percutaneous MWA group (16.2% vs 73.0%, P < .001). Conclusion There were no significant differences regarding oncologic outcomes and complications between percutaneous microwave ablation and laparoscopic partial nephrectomy for patients with cT1a renal cell carcinoma. Percutaneous microwave ablation led to smaller renal function change and lower blood loss. For patients who cannot be subjected to the risks of more invasive laparoscopic partial nephrectomy, percutaneous microwave ablation could be an alternative less invasive treatment option. © RSNA, 2020 Online supplemental material is available for this article.

An approach for retrieval of horizontal and vertical distribution of total suspended matter concentration from GOCI data over Lake Hongze.

There are a few studies working on the vertical distribution of TSM, however, understanding the underwater profile of TSM is of great benefit to the study of biogeochemical processes in the water column that still require further research. In this study, three data-gathering expeditions were conducted in Lake Hongze (HZL), China, between 2016 and 2018. Based on the in situ optical and biological data, a multivariate linear stepwise regression method was applied for retrieval of the surface horizontal distribution of TSM (TSM0.2) using GOCI (Geostationary Ocean Color Imager) data. Then, the estimation model of vertical structure of underwater TSM was constructed using layer-by-layer recursion. This study drew several crucial findings: (1) the approach proposed in this paper generated very high goodness of fit results, with determination coefficients (R2) of 0.83 (p < 0.001, N = 54), and with smaller prediction errors (the mean absolute percentage error is determined to be 16.34%, the root mean square error is 9.01 mg l-1, and the mean ratio is 1.00, N = 26). (2) The monthly surface TSM and the column mass of suspended matter (CMSM) are affected by both wind speed and precipitation in HZL. In addition, the hourly variation of surface TSM and CMSM are driven by local wind, most especially in spring and winter. (3) Compared with the non-uniform hypothesis, the CMSM derived by conventional vertical uniformity hypothesis was underestimated by almost 10% in HZL during 2016. This should warrant the attention of lake managers and lake environmental evolution researchers.

Tracking spatio-temporal dynamics of POC sources in eutrophic lakes by remote sensing.

Estimating the proportions of particulate organic carbon (POC) endmembers is essential to fully understand the carbon cycle, the function of aquatic ecosystems, and the migration of contaminants in eutrophic lakes. There is currently no effective remote sensing optical algorithm in the literature to solve this problem. In this study, a POC-source color index (SPOC) was constructed based on the terrestrial and endogenous POC ratios calculated from field-measured stable isotope (δ13CPOC) values. The SPOC algorithm traces the sources of POC by utilizing three spectral bands centered approximately at 560 nm, 674 nm, and 709 nm, covering the intrinsic optical information of different POC sources. At the same time, the SPOC algorithm shows good applicability to Ocean and Land Color Instrument (OLCI), Medium-Resolution Imaging Spectrometer (MERIS), Moderate Resolution Imaging Spectroradiometer (MODIS), and Geostationary Ocean Color Imager (GOCI) image data. The POC sources estimated using the algorithm and monthly OLCI data showed that from March 2018 to January 2019, the POC at the surface of Lake Taihu was mainly terrigenous. In addition, due to multiple factors such as algal blooms, plant physiology, river transport, regional rainfall, and carbon cycling, the distribution of POC sources exhibited strong spatial and temporal heterogeneity. Compared with other methods, it is more convenient to use remote sensing to identify the proportion of POC in different endmembers, which offers a more comprehensive understanding of the energy flows and material circulation in lakes.

Optical classification of inland waters based on an improved Fuzzy C-Means method.

Water optical clustering based on water color information is important for many ecological and environmental application studies, both regionally and globally. The fuzzy clustering method avoids the sharp boundaries in type-memberships produced by hard clustering methods, and thus presents its advantages. However, to make good use of the fuzzy clustering methods on water color spectra data sets, the determination of the fuzzifier parameter (m) of FCM (fuzzy c-means) is the key factor. Usually, the m is set to 2 by default. Unfortunately, this method assigned some membership degrees to non-belonging water type, failing to obtain the unitarity of cluster structure in some cases, especially in inland eutrophic water. To overcome this shortcoming, we proposed an improved FCM method (namely FCM-m) for water color spectra classification by optimizing the fuzzifier parameter. We collected an inland data set containing 1280 in situ spectral data and co-measured water quality parameters with a wide range of biogeochemical variability in China. Using FCM-m, seven spectrally distinct water optical clusters on Sentinel-3 OLCI (Ocean and Land Colour Imager) bands were obtained with the optimized fuzzifier (m=1.36), and the well-performed clustering result is assessed by the validated index (Fuzzy Silhouette Index=0.513). Also, the FCM-m-based soft classification framework was successfully applied to the atmospherically corrected OLCI images, which was evaluated by previous case studies. Besides, by testing FCM-m on three coastal and oceanic data sets, we verified that the optimized m should be adjusted based on the data set itself, and in general, the value gradually approaches 1 with the increase of the band number (or dimension). Finally, the effect of the improved method was tested by Chlorophyll-a concentration estimation. The results show that the algorithm------- blending by FCM-m performs better than that by original FCM, which is mainly because the FCM-m reduces the estimation error from non-belonging clusters by a stricter membership value assignation. To sum up, we believe that FCM-m is an adaptive algorithm, whose R codes are available at https://github.com/bishun945, and needs to be tested by more public data sets.

Ultrasound-guided percutaneous microwave ablation of central intraductal papilloma: a prospective pilot study.

Background: Central intraductal papilloma (IDP) has a low risk of cancer evolution; therefore, surgical treatment of IDP is controversial. We sought to validate ultrasound (US)-guided percutaneous microwave ablation (MWA) for minimally invasive treatment of IDP. Methods: Thirteen women with central IDP, including six with nipple discharge, underwent US-guided core needle biopsy and MWA from December 2016 to November 2017. Lesions histologically diagnosed as benign IDP were included. The hydro-dissection technique was used to protect the nipple during the entire ablation procedure. We evaluated and recorded data of complete ablation, volume reduction, and complications. Results: MWA was successfully performed in all patients, with 100% complete ablation, assessed by magnetic resonance imaging or contrast-enhanced US. Mean tumor size was 13.5 ± 4.1 (7.0-20.0) mm; the mean ablation time was 1.4 (0.7-10.3) min. At the median 13.7-month follow-up, mean lesion sizes at 3, 6, and 12 months after MWA were all significantly smaller than that at baseline. Total volume reduction rates were 52.3 ± 18.2% (range, 24.2-81.8%), 72.6 ± 23.1% (range, 39.4-95.9%), and 92.9 ± 7.5% (range, 75.0-100%) at 3-, 6-, and 12-month follow-up, respectively, with significant differences (p < .01). Three lesions with diameters 7 mm, 9 mm, and 12 mm disappeared completely at 3, 6, and 6 months after MWA, respectively, on US imaging. Nipple discharge disappeared immediately after MWA. Cosmetic effects were reported as excellent by all patients and no complications were observed. Conclusion: US-guided MWA of central IDP proved feasible and effective, with considerable volume reduction and satisfactory cosmetic outcomes.

Long-term observation of cyanobacteria blooms using multi-source satellite images: a case study on a cloudy and rainy lake.

High-frequency and reliable data on cyanobacteria blooming over a long time period is crucial to identify the outbreak mechanism of blooms and to forecast future trends. However, in cloudy and rainy areas, it is difficult to retrieve useful satellite images, especially in the rainy season. To address this problem, we used data from the HJ-1/CCD (Chinese environment and disaster monitoring and forecasting satellite/charge coupled device), GF-1/WFV (Chinese high-resolution satellite/wide field of view), and Landsat-8/OLI (Operational Land Imager) satellites to generate a time series of the bloom area from 2009 to 2016 in Dianchi Lake, China. We then correlated the responses of bloom dynamics to meteorological factors. Several findings can be drawn: (1) a higher bloom frequency and a larger bloom area occurred in 2011, 2013, and 2016, compared to the other years; (2) the frequency of blooms peaked in April, August, and November each year and expanded from north to south starting in July; (3) air temperature in spring and sunshine hours in summer greatly correlated to the yearly bloom area; (4) wind speed and sunshine hours strongly affected the short-term expansion of blooms and thereafter influenced the monthly bloom scale; and (5) rainfall had a strong short-term influence on the occurrence of blooms. Cyanobacteria blooms often occurred when wind speeds were less than 2.35 ± 0.78 m/s in the dry season and 2.01 ± 0.75 m/s in the rainy season, when there were 48 to 72 h of sunshine in the dry season and 35 to 57 h of sunshine in the rainy season, and when there was more than 10 mm of daily precipitation.

Remote observation of water clarity patterns in Three Gorges Reservoir and Dongting Lake of China and their probable linkage to the Three Gorges Dam based on Landsat 8 imagery.

The Secchi disk depth (ZSD) plays a critical role in describing water clarity. Several studies have shown linkages between Three Gorges Dam (TGD) and the downstream lacustrine ecosystem in the middle and lower Yangtze River basin. However, the potential influence on the ZSD fluctuation in the entire anthropogenic reservoirs of Three Gorges (ER) and Dongting Lake (DTL) has not been reported, possibly due to technical obstacles in obtaining statistically significant spatial and temporal results. We addressed this challenge by using remote sensing technology: the Landsat 8 Operational Land Imager (OLI). We proposed a new, robust remote-sensing algorithm to estimate ZSD from OLI imagery using red and green band-ratio, leading to MAPE of 21.68% and RMSE of 0.076m for ZSD ranging from 0.1m to 1.05m. After satisfactory image-based validation, the algorithm was implemented on OLI data to derive ZSD patterns over ER and DTL from 2013 to 2017. Several crucial findings can be drawn: 1) Spatial-temporal patterns of ZSD exhibited notable fluctuations over both ER and DTL, and they also demonstrated a significant correlation with each other because of the opposite temporal cycle of ZSD fluctuations between ER and DTL; 2) Temporally, monthly fluctuations of ZSD between ER and DTL had opposite temporal cycles, which was mainly attributed to the surface runoff and sediment discharge driven by the outbound runoff variations of TGD. Spatially, the heterogeneity of the ZSD pattern in ER might have resulted from the different geographical regions being divided by large anthropologic hydrological facilities, such as TGD; 3) The relationship between ZSD and total suspended matter (TSM) showed a significant negative correlation, as did the relationship between ZSD and Kd(490). These findings demonstrate that TSM often plays a principal role in light attenuation of extremely turbid inland waters; 4) An inversed phenomenon of water clarity was observed at the intersection of DTL and the Yangtze River around Chenglingji site (YRAC), which was due to the opposite temporal cycle of ZSD fluctuations between DTL and ER after the impoundment of TGD; and 5) Owing to the analysis of noise-equivalent ZSD, OLI data can be used to derive ZSD, since the imagery uncertainty is 0.07m by means of our band-ratio algorithm, which demonstrates similar results to MODIS. The proposed ZSD-derived algorithm in this study could be suitable for other turbid lakes or reservoirs to formulate related strategies of water quality management in the middle and lower Yangtze River basin, and the unveiled findings here improve our understanding of ZSD spatiotemporal fluctuations in large river-connected lakes, such as Poyang Lake.

Flavonoid-rich Scabiosa comosa inflorescence extract attenuates CCl4-induced hepatic fibrosis by modulating TGF-ß-induced Smad3 phosphorylation.

Scabiosa comosa inflorescence is a traditional Mongolian medicine in the treatment of liver diseases. In the study, we investigated the anti-fibrotic efficacy of flavonoid-rich Scabiosa comosa inflorescence extract (TF-SC) in a rat model of CCl4-induced hepatic fibrosis and explored its underlying mechanism in vitro and in vivo. Rats (Wistar, Male, weight 200-250 g) were injected intraperitoneally with CCl4 (1:1v/v in peanut oil, 2 mL/kg body weight) to induce liver fibrosis, followed by treatment with TF-SC or vehicle. In addition, transforming growth factor-ß1 (TGF-ß1)-activated hepatic stellate cells (HSCs) were used for measuring Smad3 phosphorylation. We found decrease in liver function and liver fibrosis markers in serums. Also, TF-SC decreased hydroxyproline content and collagen deposition in liver tissues. TF-SC also decreased the expression of α-SMA, collagen I and fibronectin in CCl4-induced hepatic fibrosis rats. Mechanistically, TF-SC attenuated liver fibrosis by selectively inhibiting Smad3 phosphorylation. In TGF-ß1-stimulated HSCs, TF-SC blocked the interaction between Smad3 and TGF-ß type I receptor (TßRI), suppressed subsequent phosphorylation and nuclear translocation of Smad3, and down-regulated the transcription of fibrotic genes. In conclusion, the study demonstrated that TF-SC was an effective therapeutic agent for treatment of hepatic fibrosis, and provided a molecular basis through which TF-SC exerts its anti-fibrotic effects.

CO2 switchable hollow nanospheres.

HYPOTHESIS: Hollow nanospheres, characterized by a cavity inside a solid shell, have potential applications due to their unique structure, but the unchangeable morphology and permeability of the shell restrain their further practical utilization. While several smart hollow nanospheres that can respond to pH, ion strength, and temperature have been developed, they are inclined to suffer from problems associated with high energy consumption or the difficult removal of residual stimulants. Thus, it is desirable to develop a novel and free-of-residual trigger stimulating mode. EXPERIMENTS: In this work, CO2 is used to fabricate smart hollow nanospheres composed of crosslinked poly(diethylamino-ethyl methacrylate) (PDEAEMA) network from polystyrene (PS)/PDEAEMA core-shell nanospheres by a template-removal technique. The morphology evolution of the resultant nanospheres during the fabrication process was characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA) and dynamic light scattering (DLS) and was visualized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). FINDINGS: Hollow nanospheres can be generated by experiencing a morphology change from a core nanosphere, core-shell, yolk-shell to a final hollow structure. The increase in shell-stiffness can restrain the collapse of hollow spheres. It is demonstrated that CO2 is easy to introduce and remove (via N2 input) without stimulation residues in this system. In addition, mild CO2/N2 purging can only reversibly change the swelling/collapse of hollow particles; violent CO2/N2 bubbling can reversibly regulate both the size and aggregation/re-dispersion state of the hollow nanospheres, which can be intuitively observed by atomic force microscopy (AFM).

Ultrasound guided percutaneous microwave ablation of benign breast lesions.

The benign breast lesions (BBLs) share a high incidence for women and therapy methods with minimal invasion and better cosmetic outcome are thirsted for. In this study, 122 patients with 198 biopsy-proved BBLs were enrolled. Ultrasound (US)-guided microwave ablation (MWA) was performed with local anesthesia from November, 2013 to April, 2016. The mean longest tumor size assessed was 1.6±0.7 cm (ranging 0.7-4.9 cm). MWA was successfully performed in all cases including 85 lesions adjacent to the skin, pectoralis and areola. The mean ablation time was 3.2mins (ranging 0.5-18.3 mins). 99.5% of BBLs showed complete ablation when assessed by magnetic resonance imaging and 100% of them by US. At the median 14-month follow-up, the BBLs were not palpable in 45.9 % of the cases (palpable in 90.2 % of the cases before MWA) and the mean volume reduction ratio was 78.4±33.5% for total lesions and 89.3±20.8%, 84.7±27.6% and 55.9±32.9% for ≤1.0 cm, 1.1-2.0cm and >2.0 cm lesions in 12-month follow-up, respectively. Cosmesis were reported as good or excellent in 100 % by physician and patients. No side effect was found. The MWA of the BBLs proved feasible and effective, while showing meaningful reduction in volume, palpability and cosmetic satisfying outcomes.

Tempo-spatial dynamics of water quality and its response to river flow in estuary of Taihu Lake based on GOCI imagery.

Knowledge of tempo-spatial dynamics of water quality and its response to river flow is important for the management of lake water quality because river discharge associated with rainstorms can be an important source of pollutants to the estuary. Total phosphorus (TP), chlorophyll a (Chl-a), and total suspended matter (TSM) are important indexes of water quality and important factors influencing eutrophication and algal blooms. In this study, remote sensing was used to monitor these indexes to investigate the effects of river discharge on the estuary of Taihu Lake by the largest inflow river which is Chendong River using a total of 136 Geostationary Ocean Color Images (GOCI). In situ datasets collected during the four cruise experiments on Taihu Lake between 2011 and 2015 were used to develop the TP, Chl-a, and TSM inversion models based on simple empirical algorithms: 154 points for TP (mg/L), 114 for Chl-a (µg/L), and 181 for TSM (mg/L). The spatial and temporal changes of the concentration of the three parameters in the Chendong River estuary were analyzed by combining the GOCI data, the flow of the Chendong River, and meteorological data throughout the year in 2014. The several key findings are as follows: (1) In summer and autumn, TP, Chl-a, and TSM contents were significantly higher than in winter and spring. TP and Chl-a have a few similar distribution characteristics. And organic suspended matter in summer was the main reason for the increase of the TSM concentration. (2) The severe surface erosion in the rivers cannot be ignored; the high erodibility is an important factor in the increase of TP and TSM concentrations in the estuary. The concentration of the water quality parameter showed exponential decay with distance from the shore. The concentration decreased slowly after 12 km and then remained essentially constant. (3) TP content in the Chendong River estuary decreased under steady flow inputs and dramatically increased when the flow became large. The increase in Chl-a content was linked to higher levels of TP and good weather conditions after the rain event. Higher flow rates mainly play a dilution role for the Chl-a concentration. Erosion of the surface soil via rainfall is a major source of TSM to the estuary. This paper firstly analyzes tempo-spatial dynamics of water quality and its response to river flow in estuary of Taihu Lake, helps to further understand the impact of river input on lake water quality, and is important for lake eutrophication.

CO2 -Induced Morphological Transition of Co-Assemblies from Block-Random Segmented Polymers.

The co-assembly process is an effective approach to construct hierarchically nanostructured soft materials, but morphological transition of co-assemblies upon external stimuli, particularly the "green" trigger CO2 , is not unraveled yet. Here, a segmented copolymer, poly(styrene)-block-poly[(4-vinyl pyridine)-random-((2-(diethylamino)ethyl methacrylate)] (P1), is used to co-assemble in the mixed solvent of dimethyl formamide and water with poly(ethylene oxide)-block-poly[(4-vinyl pyridine)-random-((2-(diethylamino)ethyl methacrylate)] (P2) and poly(ethylene oxide)-block-poly(acrylic acid) (P3), respectively. It is found that Janus micelles are generated from the P1-P2 pair in the presence of ferric ion, while wormlike micelles are formed from the P1-P3 duad. Upon stimulation with CO2 , Janus and wormlike aggregates are transferred into core-shell and spherical micelles, respectively.

CO(2)-responsive polyacrylamide microspheres with interpenetrating networks.

HYPOTHESIS: CO2-responsive microspheres fabricated via co-polymerization protocol are attractive due to their promising applications. However, the inevitable particles-agglomeration restrained their further utilizations. Towards this challenge, interpenetrating network (IPN) protocol would be a potential choice to construct the "intelligent" microspheres, which presents superiority in comparison with co-polymerization mode. EXPERIMENTS: A series of CO2-responsive microspheres with polyacrylamide (PAM)/poly(dimethyl aminopropyl methacrylamide) (PDMAPMA) IPN-structure were fabricated via inverse seed suspension polymerization by adjusting DMAPMA loading and crosslinking-degree of seeds. The resultant particles and responsiveness were examined using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), optical microscopy (OM) and laser particle size analyzer (LS), respectively. FINDINGS: The interior-structure and fracture-morphology of IPN-particles could be intuitively observed by SEM, showing homogeneous and compact structure without phase separation, offering the direct proof for the formation of IPN-microstructures; the particle morphology altered from IPN to IPN-membrane when gradually increasing DMAPMA concentration. Upon alternating treatment with CO2 and N2, these particles experience reversible volume expansion and collapse. Besides, the non-agglomerated responsive particles with varying composition can be prepared by changing the crosslinking-degree of seeds, from which maximum responsiveness, relative swelling volume (RSV), could reach 11.6 when PDMAPMA loading is at 87%.