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A multi-objective security-constrained optimal generation dispatch (MOSCOGD) model for large-scale power systems with wind farms and pumped-storage hydroelectric (PSH) stations is proposed. In this model, fuel consumption, emission content of atmospheric pollutants, and power purchase costs are taken into account as objective functions, and network security under basic status and N − 1 criterion conditions, and the operational limits of PSH resources are included in the constraints. The difficulties associated with discrete variables for describing the operational characteristics of PSH resources are avoided by introducing two continuous variables, generation power and pumping power, which satisfy complementary constraints. The normalised normal constraint algorithm is used to transform the three-objective optimal dispatch model into a series of single-objective optimisation models, which are solved by the interior point method, resulting in a series of evenly distributed Pareto optimal solutions (POSs) and the complete Pareto frontier surface. The computational efficiency is greatly enhanced by employing a checking–adding–checking again-adding again scheme to address network security constraints. Moreover, parallel computing is employed to improve the computation speed for solving the POSs of the MOSCOGD model. Test results on an actual large-scale power system and the modified IEEE 39-bus system demonstrate the effectiveness of the proposed method.

Rapid economic growth during the past two decades in the region surrounding the Bohai and Yellow Seas has resulted in severe pollution. Large amounts of monitoring data on persistent organic pollutants (POPs) in various environmental media have been accumulated, which allows us to conduct a fairly comprehensive assessment of the region around the Bohai and Yellow Seas to elucidate spatial patterns of pollution on a regional scale. This review summarized distributions of traditional and new POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), and perfluoroalkyl substances (PFASs), in various environmental media. In general, due to their physico-chemical properties (poor solubility in water), OCPs and PCBs were mainly detected in sediments, PBDEs and HBCDs were mainly detected in sediments and soils. PFASs, which have greater solubility, were mainly detected in the hydrosphere. For conventional POPs, such as OCPs and PCBs, Bohai Bay and Haihe River in China, Gyeonggi Bay and Lake Sihwa in South Korea were found to be most polluted areas. While for new POPs, such as PBDEs, HBCDs and PFASs, some areas were heavily polluted due to local production and applications. Estuarine and coastal areas of the Bohai Sea were more severely contaminated by POPs than coastal regions of the Yellow Sea. Overall, the present review will guide identification of key areas for strengthening risk assessment of POPs and management practices.

The key for addressing the contradiction between personalization and low cost is to achieve modularity within a product–service system (PSS). In order to obtain maximum customer satisfaction and the lowest lifecycle cost in a PSS, a portfolio of modules should be optimally planned for the service solution layer of the PSS. First, a methodology for planning the module portfolio for a PSS service solution layer is proposed. The methodology consists of four phases which are (1) service requirement acquisition, (2) finding the principal solution and building the preliminary modular structure, (3) configuring the portfolio of principal solutions, and (4) evaluating the modular solutions (the four phases include five steps). Detailed technical steps and implementation methods for each stage are presented. Second, an evaluation method is proposed for the PSS module portfolio of solutions based on utility price ratios. Based on customer utility and the lifecycle costs of the PSS, a solution is implemented incorporating a maximum ratio between customer satisfaction and service usage. Finally, a case study involving a power transformer using the PSS solution is carried out to validate the methodology proposed in the paper.

Core-shell microcapsules with a composite shell and liquid core containing isophorone diisocyanate (IPDI) were synthesized via interfacial polymerization in an oil-in-water emulsion using polyvinyl alcohol (PVA) as an emulsifier. IPDI and polymethylene polyphenylene isocyanate (PAPI) were directly mixed to form an oil phase at room temperature, followed by conversion to the core and shell of the capsules due to the different reactivities of IPDI and PAPI with diethylene triamine (DETA). The composite shell was composed of a cross-linked PVA outer layer and a dense polyurea inner layer originating from PAPI and DETA. The formation process and morphology of the capsules were studied by optical microscopy and scanning electron microscopy. The changes in the shell compositions during the synthesis process were characterized by Fourier transform infrared spectra analysis. At 600 rpm and a PVA concentration of 5 wt%, the capsules had an average diameter of 96 ± 23 μm. The weight per cent of the liquid core in the capsules was approximately 80%, and the molar ratio of IPDI and PAPI in the core was approximately 9, which was confirmed by 1H NMR. The core residue of the microcapsules was more than 50 wt% after three months in air or 10 days in water. To confirm the applicability of the prepared isocyanate microcapsules for self-healing, the capsules were incorporated into epoxy resin. The core-shell morphology of the capsules in the epoxy coating demonstrated the good practical applicability of the capsules. The microcapsules were effective for the self-healing of the epoxy coating as well as the protection of metallic substrates from corrosion.

In the present study, the concentrations and proportions of perfluoroalkyl substances (PFASs) in water and sediments (in different seasons) from the Qing River were investigated. The highest concentration of PFASs in water (207.59 ng L−1) was found in summer. The composition of PFASs in water changed with time, perfluorobutane sulfonate (PFBS) was the predominant compound in spring and summer, while long-chain PFASs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), started to increase in autumn and winter. The PFASs concentration in sediments ranged from 0.96 to 4.05 ng g−1 dw. The proportion of long-chain PFASs was higher than that of short-chain PFASs in sediments, the dominant component in sediments was PFOA with a contribution of 24.6–75.4% to total PFASs in sediments, followed by PFOS. The concentrations of PFASs in roots of emergent plants were relatively higher than those in submerged plants. However, the translocation effect of PFASs was not remarkable. Bioaccumulation factors (BAFs) of the aquatic plants indicated the absorption of PFASs were effective. BAFs in submerged plants basically increased with increasing chain length accordingly. In general, aquatic plants had the absorption preference for long-chain PFASs, especially PFOS, which was the predominant compounds in both submerged and emergent plants. Based on the results above, hornworts were selected to be cultivated indoor in the nutrient solution spiked gradient concentrations of PFOS to assess the general ecological risk. The results revealed that hornworts were resistant to PFOS and might be used as remediation flora to eliminate PFOS contamination.

Polyurethane/epoxy hybrid materials from CO2-sourced monomer were prepared via an environmentally-friendly and non-toxic route, which avioded the use of toxic isocyanate. A series of non-isocyanate polyurethane (NIPU)/epoxy hybrid materials, with different and controlled architectures, were synthesized from CO2, polypropylene glycol diglycidyl ether (PPGDGE), amines and diglycidyl ether of bisphenol-A (BADGE). Around 12 wt% CO2 was incorporated into PPGDGE to form a five-membered cyclic carbonate (5CC-PPGDGE). The complete conversion and selectivity of PPGDGE were obtained. The kinetics of 5CC-PPGDGE was investigated by reacting it with 1,2-ethylenediamine (EDA) at different temperatures. NH2-terminated pre-polymers were obtained by reacting 5CC-PPGDGE with various excessive amines. Finally, the hybrid materials were obtained by curing pre-polymers with BADGE. The results showed that a high content of amine with more functional groups led to better mechanical performances than diamine-based hybrid materials. This is the first time that architectures have been controlled by altering the amine ratio and functionality. And these hybrid materials exhibited satisfactory mechanical performances. The DETA-based and TETA-based materials with high amine ratio exhibited a tensile strength of 15.0 MPa and 12.5 MPa, accompanied with elongation at break of 151.3% and 170.9%, respectively. The gel content, glass transition temperature and thermodynamic stability went up first and then declined with the increase of amine ratio, which demonstrated the architectures of hybrid materials ranged from defective to cross-linked and linear structures.

The wide use of antibacterial hand soaps containing triclosan has raised a potential threat to health, and the detection of triclosan is thus extremely important. Here we introduce an efficient approach for nondestructive screening of triclosan in hand soaps. Using Raman spectroscopy in a digitally labelled approach, we utilized the strategy of modified competitive adaptive reweighted sampling (MCARS) to assign spectral features according to a higher density wavelet transform (HDWT) domain, which is named digital labeled Raman spectroscopy (DLRS). DLRS efficiently isolates the features of triclosan from matrix components, enabling the nondestructive quantitative analysis of triclosan in real antibacterial hand soaps, irrespective of the details of the soap matrix. We demonstrate the feasibility of DLRS using a practical test in which we seek to quantify triclosan in several kinds of antibacterial hand soaps nondestructively. The results illustrate DLRS as a promising tool for nondestructive detection of triclosan in antibacterial hand soaps without any sample pretreatment, which may well extend to digital separation of some analytes of interest in the presence of complex chemical substances.

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are extremely persistent in the environment, and have the potential for long-range transport. The present study focused on the Daling River and its tributary, a larger river flowing into Liaodong Bay of the Bohai Sea. Recent studies have shown the elevated levels of PFOS and PFOA in the Daling River. Hence, the objective of this study was to investigate the seasonal changes, fate and transport modeling of PFOS and PFOA concentrations using one-dimensional DHI MIKE-11 river model. We designed three scenarios to assess the risk of PFOS and PFOA in surface water: the measured concentrations, constant maximum and the magnitude of a continuous constant load. The mean absolute errors divided by the mean of measured concentrations were 41–64% for PFOS and 29–36% for PFOA. The result indicated that PFOS and PFOA in the downstream of the Daling River would not reach a harmful level with the current load. The fluorochemical parks contributed an average of 44.57% of the total PFOS and 95.44% of the total PFOA flow that reached the estuary. The mass flow was observed as 1.74 kg y −1 for PFOS and 40.57 kg y −1 for PFOA to the Bohai Sea. These modeling results may be useful for monitoring the status and trends of emerging POPs and will help the determination of the risk to both humans and wildlife, in the estuarine and coastal areas of the Bohai Sea, China.

Sepsis is a major cause of mortality in seriously ill patients characterized by a series of severe systemic inflammatory responses due to an infection. Thus, there is a critically need to search more accurate biomarkers and targets for diagnosis and treatment of sepsis. Our study showed that miR-212-3p was up-regulated in LPS-treated macrophage RAW264.7 cells. Overexpression of miR-212-3p in RAW264.7 cells led to suppression of pro-inflammatory cytokines (TNF-α and IL-6) induced by LPS. Bioinformatic predictions and experimental researches both revealed that HMGB1 was a direct target of miR-212-3p. Meanwhile, the results showed that overexpression of miR-212-3p inhibited the cytoplasmic translocation of HMGB1 in LPS-induced RAW264.7 cells. Subsequently, transfection of the pcDNA3.1/HMGB1 plasmid, which produced HMGB1 overexpression, exhibited similar effects as the LPS-induced macrophage inflammatory response and markedly activated the MAPKs including p38, ERK and JNK phosphorylation. Furthermore, we also found that the phosphorylation of p38 MAPK and ERK was downregulated by miR-212-3p mimics upon LPS injection. In conclusion, these results reveal that miR-212-3p directly targets HMGB1 to suppress inflammatory response in LPS-induced RAW264.7 cells. All our findings indicate that miR-212-3p may act as a potential pharmacological target for promising and effective therapeutic intervention in microbial infection in the future.

Eutrophication has become one of the most serious threats to aquatic ecosystems in the world. With the combined drivers of climate change and human activities, eutrophication has expanded from warm shallow lakes to cold-water lakes in relatively high latitude regions and has raised greater concerns over lake aquatic ecosystem health. A two-year field study was carried out to investigate water quality, phytoplankton characteristics and eutrophication status in a typical alpine glacial lake of Tianchi, a scenic area and an important drinking water source in the Xinjiang Autonomous Region of China, in 2014 and 2015. Clear seasonal and annual variations of nutrients and organic pollutants were found especially during rainy seasons. For the phytoplankton community, Bacillariophyta held the dominant position in terms of both species and biomass throughout the year, suggesting the dominant characteristics of diatoms in the phytoplankton structure in such a high-altitude cold-water lake. This was quite different from plain and warm lakes troubled with cyanobacterial blooming. Moreover, the dominant abundance of Cyclotella sp. in Tianchi might suggest regional warming caused by climate change, which might have profound effects on the local ecosystems and hydrological cycle. Based on water quality parameters, a comprehensive trophic level index TLI (Σ) was calculated to estimate the current status of eutrophication, and the results inferred emerging eutrophication in Tianchi. Results from Canonical Correspondence Analysis (CCA) and correlation analysis of phytoplankton genera and physico-chemical variables of water indicated that abiotic factors significantly influenced the phytoplankton community and its succession in Tianchi Lake. These abiotic factors could explain 77.82% of the total variance, and ammonium was identified as the most discriminant variable, which could explain 41% of the total variance followed by TP (29%). An estimation of annual nutrient loadings to Tianchi was made, and the results indicated that about 212.97 t of total nitrogen and 32.14 t of total phosphorus were transported into Tianchi Lake annually. Human socio-economic activities (runoff caused by historical overgrazing and increasing tourism) were identified as the most important contributors to Tianchi nutrient loadings.

Herein, we construct a structure-switchable gemcitabine (Ge)-containing DNA nanogel that can respond to the intracellular acidic environment, subsequently facilitating the chemodrug release inside the cells. Based on the structural similarity between Ge and deoxycytidine (dC), dC nucleotides in the component DNA strands used for nanogel assembly are fully replaced by Ge during their synthesis. By changing the designed sequences, two Ge-containing Y-shaped motifs with different sticky ends are first assembled and then associated together to form nanogel by sticky-end hybridizations. In particular, one of the sticky-end sequences is arbitrarily designed to be rich of Ge and the other is designed to be partially complementary to the first Ge-rich sticky end. At the neutral or basic condition, the Ge-rich sticky ends hybridize with the partially complementary sticky ends on the second Y motifs, keeping the assembled nanogel stable. Upon being exposed to the acidic condition, Ge-rich sticky ends intend to form intramolecular i-motif-like quadruplex structures, resulting in the disassembly of the nanogel. On the one hand, the nanosized feature enables the Ge-containing nanogel with rapid cellular uptake behavior. On the other hand, the pH-responsive feature endows the rapid disassembly of the nanogel to facilitate the enzymatic drug release inside the cell, resulting in the enhanced anticancer activity of the DNA-based drug delivery system.

Energy storage has been proven to yield positive effects on planning, operation and control of electric grids. It has become a crucial task to properly model the energy storage systems (ESS) under the framework of grid optimization on transmission and distribution networks including microgrids. This paper presents a review on mathematical models and test cases of ESSs used for grid optimization studies, where the network constraints of power systems are included. The existing ESS models are mainly classified into two categories - linear and nonlinear models. The two main categories are further divided into several subcategories respectively; such as mixed-integer linear and convex nonlinear sub-categories. Based on the review and discussions, this paper aims at providing suggestions for choosing proper ESS models for specific grid optimization studies considering the chosen power network model.

After a severe disaster, the impacted distribution systems are generally in a state of chaos, which makes restoration of electricity service extremely hard. To facilitate the development of systematic and fast restoration schemes, this paper provides a scenario-based analysis of post-disaster distribution systems. The properties of post-disaster power systems are investigated in order to classify various types of post-disaster cases into a limited number of scenarios with some pre-defined features. A mixed-integer nonlinear programming (MINLP) model is proposed to determine the optimal locations and optimal size of mobile diesel generators in distribution systems so as to supply critical loads right after the natural disasters. Test results on the IEEE 37-node test feeder demonstrated the effectiveness of proposed optimization model.

Herein, we report a non-cationic DNA-crosslinked nanogel for intracellular delivery of a Cas9 and single guide RNA (Cas9/sgRNA) complex. A DNA-grafted polycaprolactone brush (DNA-g-PCL) is first loaded with the Cas9/sgRNA complex and then crosslinked by DNA linkers via nucleic acid hybridization to form a nanosized hydrogel, in which the gene editing tools are embedded and protected inside. With compact architecture, the Cas9/sgRNA complex-containing nanogel exhibited excellent physiological stability against nuclease digestion and enhanced cellular uptake efficiency, making the delivery system a promising tool for target genome editing.

Aim: The objective of this study was to systematically compare the safety and efficacy of porous tantalum metal (TM) implants and autograft in single-level anterior cervical discectomy and fusion. Methods: Potential academic articles were acquired from the Cochrane Library, Medline, PubMed, Embase, Science Direct and other databases. The time range used was from the inception of the electronic databases to March 2018. Gray studies were identified from the references of included literature reports. STATA version 11.0 (Stata Corporation, TX, USA) was used to analyze the pooled data. Results: Four randomized, controlled trials (RCTs) were identified according to the retrieval process. There were significant differences in operation time (mean difference [MD]: -28.846, 95% confidence interval [CI: -47.087, -10.604], p = 0.002) and satisfaction rate (odds ratio [OR]: 2.196, 95% CI: [1.061–4. 546]; p = 0.034). However, no significant difference was detected in blood loss (MD: -73.606, 95% CI: [-217.720, 70.509], p = 0.317), hospital stay (MD: -0.512, 95% CI [-1.082, 0.058]; p = 0.079), fusion rate (OR: 0.497, 95% CI [0.079, 3.115]; p = 0.455), visual analog scale (MD: -0.310, 95% CI [-0.433, -0.186]; p Conclusion: Porous TM implants are equally as effective and safe as autograft in anterior cervical discectomy and fusion processes. In addition, porous TM implants could reduce operation time and improve clinical satisfaction significantly.

The spontaneous self-assembly of chiral nanoparticles (NPs) into stationary fabrication has garnered great interest in technique investigation and science advancement due to its expected apparent properties via orderly collective behaviors. However, this kind of characterization of assembled nanoparticles superstructure (NPS) is rarely reported and is distinguished with monodispersed chiral NPs. In this work, we used l-cysteine (Cys) as the chiral molecule in the form of functional surfactant, which had capped CdS/CdTe NPs and was treated as a linkage bridge for constructing orderly assembled NPS. Among the circular dichrosim (CD) phenomenon, Cys ligands exhibit related changes in CD absorption, while whole-molecule solution was used for treatment in different pH-controlling procedures. Synthesized chiral NPs are organized into ordered rod-shaped NPS during the spontaneous self-assembly process, and the CD response of NPS is monitored in different cultivating times; it showed a persuasive response appears in sum frequency generation (SFG) spectroscopy. Both experimental works and theory calculation convey that the ordered stacking of chiral stabilizer and the chirality of NPS, which are identified from chiral molecular status and their collective optical activity, originated from ligand asymmetry.

Hyperspectral imaging (HSI) is a popular method of substance identification and mapping in many fields. Light-emitting diodes (LEDs) can be introduced as an active light source, which have been widely used with the distinct advantages of small size, low energy consumption, long lifetime, and fast switching. In this paper, we propose an active HSI system that is based on a multi-wavelength LED-array light source. This LED-based HSI system has a simple and stable configuration, without the complex dispersive spectrometer and mechanical scanning device. The proposed HSI system has been validated using the standard color checker, showing a reliable spectral performance. Moreover, the spatial-spectral information of Chinese paper-cuttings has been successfully extracted, which indicates the great potential in practical applications.

Brucella is an intracellular pathogen that invades a host and settles in its immune cells; however, the mechanism of its intracellular survival is unclear. Modification of small ubiquitin-related modifier (SUMO) occurs in many cellular activities. E2 conjugating enzyme 9 (Ubc9) is the only reported ubiquitin-conjugating enzyme that links the SUMO molecule with a target protein. Brucella's intracellular survival mechanism has not been studied with respect to SUMO-related proteins and Ubc9. Therefore, to investigate the relationship between Brucella melitensis 16M and SUMO, we constructed plasmids and cells lines suitable for overexpression and knockdown of SUMO1 and Ubc9 genes. Brucella 16M activated SUMO1/Ubc9 expression in a time-dependent manner, and Brucella 16M intracellular survival was inhibited by SUMO1/Ubc9 overexpression and promoted by SUMO1/Ubc9 depletion. In macrophages, Brucella 16M-dependent apoptosis and immune factors were induced by SUMO1/Ubc9 overexpression and restricted by SUMO1/Ubc9 depletion. We noted no effect on the expressions of SUMO1 and Ubc9 in B. melitensis 16M lipopolysaccharide-prestimulated mouse RAW264.7 macrophages. Additionally, intracellular survival of the 16M△VirB2 mutant was lower than that of Brucella 16M (p < 0.05). VirB2 can affect expression levels of Ubc9, thereby increasing intracellular survival of Brucella in macrophages at the late stage of infection. Collectively, our results demonstrate that B. melitensis 16M may use the VirB IV secretion system of Brucella to interact with SUMO-related proteins during infection of host cells, which interferes with SUMO function and promotes pathogen survival in host cells.

Fake liquors have caused severe body injuries or even deaths worldwide, rapid detection of such lethal drinks is thus quite necessary. Methanol has been identified as a primary cause of the problem, so methanol monitoring is critical to the detection of fake liquors. The present work provides an effective strategy for rapid detection of different lethal fake liquors. Using gas-phase Fourier transform infrared spectroscopy in a digitally labeled approach, the spectral bands of methanol were extracted by the iterative discrete wavelet transform for classification, which is named as digitally labeled gas-phase Fourier transform infrared spectroscopy. In digitally labeled gas-phase Fourier transform infrared spectroscopy, principal component analysis and least square support vector machine were combined to discriminate problematic samples using the iterative discrete wavelet transform filtered signals. As a result, the method could cleverly extract spectral features of methanol from the alcoholic drinks in the presence of uncontrolled matrix effects. The recognition accuracy was higher than 97.0%, and each measurement was done within 3 min. The results illustrate that the digitally labeled gas-phase Fourier transform infrared spectroscopy method serves well to rapidly discriminate fake liquors as an efficient and promising tool, and could be well extended to detection of any other targeted volatile substance in complicated systems.

Though the convex optimization has been widely used in power systems, it still cannot guarantee to yield a tight (accurate) solution to some problems. To mitigate this issue, this paper proposes an ensemble learning based convex approximation for AC power flow equations that differs from the existing convex relaxations. The proposed approach is based on quadratic power flow equations in rectangular coordinates and it can be used in both balanced and unbalanced three-phase power networks. To develop this data-driven convex approximation of power flows, the polynomial regression (PR) is first deployed as a basic learner to fit convex relationships between the independent and dependent variables. Then, ensemble learning algorithms such as gradient boosting (GB) and bagging are introduced to combine learners to boost model performance. Based on the learned convex approximation of power flows, optimal power flow (OPF) is formulated as a convex quadratic programming problem. The simulation results on IEEE standard cases show that, in the context of solving OPF, the proposed data-driven convex approximation outperforms the conventional SDP relaxation in both accuracy and computational efficiency, especially in the cases that the conventional SDP relaxation fails., Comment: 8 pages, 8 figures, 4 tables

Objective To find risk factors for contralateral hematoma progression (CHP) in bilateral chronic subdural hematomas after initial unilateral evacuation. Methods We retrospectively analyzed 53 patients with bilateral chronic subdural hematomas who underwent unilateral surgical evacuation in our department. Risk factors for CHP were identified by univariate analysis, a P value Results The progression rate was 32.08%, the average progression interval was 2.32 months. The progression rate of the homogeneous hypodense group was significantly higher than that of the other density group (P = 0.017). The limited type of contralateral hematoma had a significantly lower progression rate than that of the widespread type (P = 0.001). Both pre- and postoperative volume of contralateral hematoma were significantly more in the CHP group compared with the contralateral hematoma without progression group (P = 0.031 and P = 0.001, respectively). Of the 4 risk factors, only postoperative volume of contralateral hematoma was an independent risk factor in multivariate logistic regression model (P = 0.033; 95% confidence interval, 1.005–1.124). The cut-off values of contralateral hematoma volume before and after operation were 29.27 cm3 and 37.84 cm3, respectively. Conclusions Contralateral hematoma volume after operation is an independent risk predictor for CHP after unilateral evacuation. An additional surgery on contralateral hematoma or medical treatment should be taken into consideration if the volume is >37.84 cm3 in the first cranial computed tomography scan after surgery.

We study the question whether rational homogeneous spaces are rigid under Fano deformation. In other words, given any smooth connected family f:X -> Zof Fano manifolds, if one fiber is biholomorphic to a rational homogeneous space S, whether is f an S-fibration? The cases of Picard number one were studied in a series of papers by J.-M. Hwang and N. Mok. For higher Picard number cases, we notice that the Picard number of a rational homogeneous space G/P is less or equal to the rank of G. Recently A. Weber and J. A. Wisniewski proved that rational homogeneous spaces G/P with Picard numbers equal to the rank of G (i.e. complete flag manifolds) are rigid under Fano deformation. In this paper we show that the rational homogeneous space G/P is rigid under Fano deformation, providing that G is a simple algebraic group of type ADE, the Picard number equal to rank(G)-1 and G/P is not biholomorphic to F(1, 2, P^3) or F(1, 2, Q^6). The variety F(1, 2, P^3) is the set of flags of projective lines and planes in P^3, and F(1, 2, Q^6) is the set of flags of projective lines and planes in 6-dimensional smooth quadric hypersurface. We show that F(1, 2, P^3) have a unique Fano degeneration, which is explicitly constructed. The structure of possible Fano degeneration of F(1, 2, Q^6) is also described explicitly. To prove our rigidity result, we firstly show that the Fano deformation rigidity of a homogeneous space of type ADE can be implied by that property of suitable homogeneous submanifolds. Then we complete the proof via the study of Fano deformation rigidity of rational homogeneous spaces of small Picard numbers. As a byproduct, we also show the Fano deformation rigidity of other manifolds such as F(0, 1, ..., k_1, k_2, k_2+1, ..., n-1, P^n) and F(0, 1, ..., k_1, k_2, k_2+1, ..., n, Q^{2n+2}) with 0, 39 pages, Comments are welcome!

BACKGROUND: The incidence of stroke or death in carotid endarterectomy (CEA) versus carotid artery stenting (CAS) cannot be estimated accurately. We aimed to compare periprocedural stroke or death in patients with symptomatic or asymptomatic carotid artery stenosis (CS) treated with CEA versus CAS. METHODS: Ten randomized trials (with ≥100 randomized patients per trial) compared the relative effectiveness of CAS and CEA for the prevention of stroke or death. RESULTS: In the symptomatic group during the periprocedural period, the results showed that the risk of death or any stroke [risk ratio (RR): 0.627; 95% CI: 0.497–0.792; P70% increased the incidence of periprocedural death or stroke for post-CEA patients (RR: 2.166, 95% CI: 1.112 to 4.220, P=0.023), but no risk factors were identified for post-CAS. Regarding the asymptomatic group, the results demonstrated that patients randomized to CEA had a significantly reduced risk of periprocedural stroke (RR: 0.518; 95% CI: 0.281–0.954; P=0.035), which seems to be driven by periprocedural minor stroke (RR: 0.482; 95% CI: 0.231–0.982; P=0.046). CONCLUSIONS: Among patients with symptomatic CS, CEA was associated with reduced rates of periprocedural stroke and periprocedural nondisabling stroke. Among patients with asymptomatic CS, the rates of minor stroke and stroke in general were higher with stenting than with CEA. Based on the current data, CEA is more beneficial than CAS for 30-day stroke prevention.

The manufacture of fluorochemicals can lead to high levels of perfluoroalkyl acids (PFAAs) contaminating the surrounding environment and consequently elevated exposure to the local residents. In this study, measurements of PFAAs associated with indoor and outdoor dusts around a mega fluorochemical industrial park (FIP) were made. Perfluorooctanoic acid (PFOA) and short-chain perfluoroalkyl carboxylic acids (C4-C7 PFCAs) were the predominant forms in all samples. The signature of the PFAAs in dusts in the local area matched that found within the FIP complex. The contamination plume in the local area could be linked to the prevailing wind direction starting from the FIP. The concentrations decreased exponentially with distance from the FIP (noticeably in the first 5 km). PFAAs contamination could be detected at the most distant location, 20 km away from the FIP. The relatively small size of this high contamination zone suggested that the PFAAs were associated with large/dense dust particles with limited ability to be transported far by the air. The concentrations of PFAAs were higher in indoor dust (73-13,500 ng/g, median: 979 ng/g) than those in outdoor dust (5-9,495 ng/g, median: 62 ng/g) at every location. The highest estimated daily intake of PFOA via dust ingestion (26.0 ng/kg.bw/day) was for toddlers (2-5 yrs) living in 2 km away from the FIP, which is posing human health risk, though within the provisional tolerable daily intake values.

Multiscale graphene oxide/carbon fiber (GO/CF) reinforcements were developed for polyurethane (PU) elastomer composites. GO was first coated on CF surface by electrophoretic deposition (EPD), aiming to improve the CF/PU interfacial adhesion. The EPD process improved the mechanical anchoring and chemical interaction between CFs and PU through increased surface roughness and oxygen content of CFs, thereby improved the CF/PU interfacial shear strength. The fibers were then mechanically mixed with GO to achieve a multiscale reinforcement. The strengthening of the matrix, especially the local stiffening of fiber/matrix interphase, is beneficial for the interfacial mechanical anchoring. The multiscale reinforcement resulted in an improvement of 46.4% in the tensile strength of PU elastomer. Compared with untreated-CF/PU, individual process of EPD treatment and mechanical mixing of GO resulted in an improvement of 16.9% and 13.9% of the strength, respectively. The enhanced reinforcing performance of GO-deposited CFs was attributed to the improved fiber–matrix interfacial adhesion.

In this study, silane coupling agent 3-chloropropyltrimethoxysilane (CTS) was used for improving the distribution of water glass (WG) in the polyurethane (PU) matrix and increasing the crosslinking density of PU/WG grouting materials. The optimum dosage of CTS and the pretreatment time of WG were investigated. The effect of CTS on the surface property of WG and the fracture morphology of the PU/WG composites was studied by contact angle measurement and scanning electron microscopy, respectively. The effect of CTS on the mechanical properties of PU/WG grouting materials was systematically studied by compression test, fracture mechanical test, flexural test and dynamic mechanical analysis. The introduction of CTS in the PU/WG grouting materials improved the surface property of WG, the homogeneous distribution of polysilicate particles in PU matrix, the compressive property of PU/WG composites by 11.65–40.65%, the fracture toughness by 9.68%, the fracture energy by 21.33%, the flexural strength by 6.60%, the flexural modulus by 15.85%, and the dynamic mechanical properties of the composites. A possible mechanism of the functions of CTS in the PU/WG grouting materials was proposed.

In this paper, distributed energy storage (DES) devices, like batteries and ultra-capacitors, are used to alleviate detrimental impacts of high penetration photovoltaic (PV) resources on distribution systems. The impacts are studied at mainly two time resolutions—one minute and one hour. To determine accurately the size of the required DES for the purpose of mitigating the impacts of large-scale distributed PV, sizing procedures based on OpenDSS are proposed. After determining the total size of the required DES, optimization techniques can be used to choose the optimal locations for the DES along the feeder, which is a continuous optimization problem taking into account equality constraints of the AC power flow. The continuity of the problem and the radial network structure make it possible to apply a convex optimization technique called second order cone programming (SOCP) relaxation to obtain the globally optimal solution and avoid the problem of NP-hardness. The exactness of the introduced SOCP relaxation is sensitive to the chosen objective function and additional quadratic equalities. The necessary and sufficient condition of exactness for the SOCP relaxation of the DES optimal allocation and operation in radial distribution systems is studied. The proposed methods are applied to an actual feeder in the southwestern US with high penetration of PV using actual measured data. The simulation results demonstrate the efficacy of the proposed approaches.

Perfluoroalkyl acids (PFAAs) can be released to water bodies during manufacturing and application of PFAA-containing products. In this study, the contamination pattern, attenuation dynamics, sources, pathways, and risk zoning of PFAAs in surface and ground water was examined within a 10 km radius from a mega-fluorochemical industrial park (FIP). Among 12 detected PFAAs, perfluorooctanoic acid (PFOA) dominated, followed by shorter-chained perfluoroalkyl carboxylic acids (PFCAs). PFAA-containing waste was discharged from the FIP, with levels reaching 1.86 mg/L in the nearby rivers flowing to the Bohai sea together with up to 273 μg/L in the local groundwater in the catchment. These levels constitute a human health risks for PFOA and other shorter-chained PFCAs within this location. The concentrations of ∑PFAAs in surface water strongly correlated with the local groundwater. The dominant pollution pathways of PFAAs included (i) discharge into surface water then to groundwater through seepage, and (ii) atmospheric deposition from the FIP, followed by infiltration to groundwater. As the distance increased from the source, PFAAs levels in groundwater showed a sharp initial decrease followed by a gentle decline. The contamination signal from the FIP site on PFAAs in groundwater existed within a radius of 4 km, and at least 3 km from the polluted Dongzhulong River. The major controlling factor in PFAA attenuation processes was likely to be dilution together with dispersion and adsorption to aquifer solids. The relative abundance of PFOA (C8) declined while those of shorter-chained PFCAs (C4–C6) increased during surface water seepage and further dispersion in groundwater. Keywords: PFAAs, Fluorochemical industrial park, Transport, Attenuation, Risk

Castor oil polyol (COP) having a hydroxyl number of 400 mg KOH/g was prepared through the transesterification reaction of castor oil with glycerol. The effect of reaction temperature on the composition, hydroxyl number and viscosity of the COP products was studied. A series of rigid polyurethane foams were synthesised using the mixtures comprising COP and a petroleum-based polyol with various proportions as polyol component. It was found that the foaming rate, compressive strength and dimensional stability and morphology of resulting foams were dominated by the foam formulation, in a more accurate way, COP content in the polyol mixtures. The combination of expandable graphite and dimethyl methyl phosphonate exhibited stronger flame retardant function which was ascribed to the synergistic effect associated with the simultaneous presence of the two additives. An improvement in thermal stability was observed due to the inclusion of the flame retardants.

Background: Tibia fracture (BF) before stroke shortly causes long-term post-stroke memory dysfunction in mice. The mechanism is unclear. We hypothesize that BF enhances neuroinflammation and blood brain barrier (BBB) breakdown in the hippocampus and white matter (WM) damage. Methods: Mice were assigned to groups: BF, stroke, BF+stroke (BF 6 h before stroke) and sham. BBB integrity was analyzed 3 days after the surgeries and WM injury was analyzed 3 days and 8 weeks after the surgeries. Results: Stroke and BF+stroke groups had more activated microglia/macrophages and lower levels of claudin-5 in the ipsilateral hippocampi than the BF group. BF+stroke group had the highest number microglia/macrophages and the lowest level of claudin-5 among all groups and had fewer pericytes than BF group. Stroke and BF+stroke groups had smaller WM areas in the ipsilateral basal ganglia than the sham group 8 weeks after the injuries. The BF+stroke group also had smaller WM areas in the ipsilateral than sham and BF groups 3 days after the injuries and in the contralateral basal ganglia than stroke and BF groups 8 weeks after the injuries. Conclusions: BF exacerbates neuroinflammation and BBB leakage in the hippocampus and WM damage in basal ganglia, which could contribute to the long-lasting memory dysfunction in BF+stroke mice.

The discharge of Cu2+ from industrial wastewater to nature will pose a serious threat to human health. In order to separate Cu2+ from sewage, the copper removal process with hexagonal boron nitride (h-BN) membrane is studied using molecular dynamics simulations. The relationship between water flux and pore size, pore chemistry and external pressure is analyzed in detail, and the filtration mechanism of Cu2+ is also discussed. The results show that water flux is proportional to the pore size and external pressure. The water flux across the membrane with N-edged pore is larger. There is a potential barrier for Cu2+ with the membrane of B-edged pore, which is beneficial to the separation of Cu2+. When the radius of the pore is smaller than the second hydration radius of Cu2+, Cu2+ removal capability is better. In particular, nanoporous h-BN membrane with B5 pores has several orders of magnitude higher water permeability and 1–2 orders of magnitude lower energy consumption than traditional reverse osmosis membranes. Overall, this work has a guiding role in the liquid phase separation of heavy metal ions.

A novel coarse-grained (CG) model for poly (1-vinyl-3-ethylimidazolium) tetrafluoroborate ([PVEim][BF4]) was developed with the all-atom (AA) molecular dynamics simulations as a benchmark. In this model, the bonded and non-bonded potential parameters of CG force field were obtained by Boltzmann and iterative Boltzmann inversion, respectively. The simulation results show that the novel CG model can accurately describe the structural characteristics and reproduce the thermodynamic properties comparing with the AA force field model. The deviation of densities values between CG model and experiment was within 5% at 298 K. This work can be a useful guide to the computational for large-scale PILs systems.

Shape memory polymer composites (SMPCs) are gradually applied to deployable space structures due to their special shape memory effect and excellent mechanical properties. The design, material properties and performances of a smart hinge based on SMPC were investigated in this paper. The micro-buckling problem of the inner sheet of the hinge was solved by designing the bending path. The mechanical properties of materials with different fiber layers were characterized. The performance investigations began with obtaining the optimal voltage, followed by the test of the recovery speed, heat distribution and digital image correlation (DIC) for the SMPC hinge. The recovery force and deployed stiffness of the hinges with the different fiber layers followed by the observation of the variation of the surface morphology were obtained. The results indicated that the 3-layer hinge performed better than the 2-layer and 4-layer hinges in terms of deployed stiffness and surface morphology. Additionally, the strain variation of the hinge sheets was obtained. Finally, the smart hinge was assembled into the solar array prototype and the ground deployment verification test was successfully carried out. The research results of the hinge are expected to have reference significance in deployable space structures.

With the implementation of smart distribution technology, the real-time pricing scheme has emerged as a critical subject for energy management systems. In this paper, we propose a bilevel optimization model that computes a transactive price signal representing the impact of wholesale market locational marginal prices on retail customers’ demand response participation. At the upper level of the proposed model, the electricity utility company (EUC) determines the optimal energy procurement and transactive price signals for demand response aggregator (DRA). At the lower level, each DRA adjusts its electricity consumption profile using the transactive price signals. The adjusted DRA consumption profile is fed back to the upper level problem as the iteration continues. The interactions among DRAs are simulated as a non-cooperative game. The proposed model is transformed into a mixed-integer quadratically constrained programming through using the Karush-Kuhn-Tucker (KKT) conditions. The generalized disjunctive programming is introduced when linearizing the bilinear terms in KKT conditions by applying piecewise McCormick relaxation and big-M disjunctive constraints. The numerical results demonstrate the effectiveness of our model and the proposed solution method.

Carbon dioxide based amino-alcohol compound (CO2-AA) with both alcohol and amino units in the molecular was prepared by chemical fixation of CO2 with 1, 4-butanediol diglycidyl ether and ethylenediamine, which was further used as chain extender to the preparation of waterborne polyurethanes (CO2-WPUs). Since the reacting activity of isocyanate groups in WPU prepolymer with NH2 was much faster than that with OH, hydroxyl groups could be maintained in the system and strengthen the hydrogen bonding interaction in WPU endowing the materials with some special properties. Specifically, the unique structure of CO2-AA improved mechanical, water/solvents resistance and hydrolysis/oxidation resistance properties of CO2-WPUs. Mechanical properties of the CO2-WPUs changed slightly during immersion in water, 0.25% NaOH and 6.00% H2O2 solution, while the WPUs prepared from typical chain extender ethylenediamine almost lost their mechanical properties after immersed in the solutions for 5 h. Moreover, the CO2-WPU films showed considerable thermal stability. The study suggested the novel CO2-AA might be a promising chain extender to improve the water/solvent resistance and hydrolysis/oxidation resistance of WPU.

Spectral-based method has been widely used for the qualitative and quantitative analysis of different substances in various fields. The spectral recovery method is a crucial role in the spectral-based method, which can save the measurement cost and computation time in measuring. In this paper, we introduce a simple and reliable spectral recovery method base on prior datasets, which can tolerate substantial spectral noise. The method has been successfully applied in the quantitative analysis of the pharmaceutical mixture. The SNR of the recovery spectra can be increased by ~100 times.

The purpose of the present study was to conduct a meta-analysis to systematically compare the incidence rates of in-stent restenosis after carotid artery stenting (CAS) and restenosis after carotid endarterectomy (CEA) for patients with atherosclerotic carotid stenosis.We retrieved potential academic reports comparing restenosis between CEA and CAS from the MEDLINE, PubMed, and EMBASE databases and the Cochrane Library from the date of the first CEA (January 1951) to July 20, 2018. The references of the identified studies were carefully reviewed to ensure that all available reports were included in the present study.Our meta-analysis included 27 studies (15 randomized controlled trials, 12 nonrandomized controlled trials) and 20,479 participants with atherosclerotic carotid stenosis. A statistically significant difference was found in the cumulative incidence of restenosis70% between CEA and CAS (risk difference, -0.033, 95% confidence interval [CI] -0.054 to -0.013; P = 0.002). For the restenosis70% outcomes, although CEA was relevant with a lower rate of restenosis than CAS within 6 months (odds ratio [OR], 0.495; 95% CI, 0.285-0.861; P = 0.013) and 1 year (OR, 0.626; 95% CI, 0.483-0.811; P0.001), no statistically significant differences were found at 1.5 years (P = 0.210), 2 years (P = 0.123), 4 years (P = 0.124), 5 years (P = 0.327), or 10 years (P = 0.839). For the restenosis50% outcomes, a significant difference was found in the rate of restenosis between the CEA and CAS groups within 1 year (OR, 0.317; 95% CI, 0.228-0.441; P0.001) but not at 1.5 years (P = 0.301), 2 years (P = 0.686), or 5 years (P = 0.920). No nominally significant effects were demonstrated with respect to the cumulative incidence of occlusion (P = 0.195) or the cumulative incidence of restenosis for symptomatic patients (P = 0.170) between CEA and CAS.Although CAS was preferred over CEA, regardless of restenosis50% or70% after revascularization within 1 year, no significant difference was observed with extension of the follow-up period to1 year. CAS was not associated with a greater cumulative incidence of occlusion or the cumulative incidence of restenosis for symptomatic patients.

This paper introduces a micro-nexus of water and energy which can be considered as one of the fundamental infrastructures of future communities, such as smart buildings, cities, and villages. For the electricity side, an alternating current (AC) power flow model integrated with battery energy storage and renewable generation is adopted. The nonlinear hydraulic characteristics of pipe networks is also considered in the proposed micro water-energy nexus (WEN) model. Integer variables are involved to represent the on/off state of pumps. Base on the proposed nexus model, a co-optimization framework of water and energy networks is developed. We tested the overall co-optimization model, which is a mixed-integer nonlinear programming problem, on a water-energy nexus that consists of the IEEE 13-bus distribution system and an 8-node water distribution network. The simulation results demonstrate that the cost-efficiency of the co-optimization framework is higher than optimizing two systems independently.

Perfluoroalkyl acids (PFAAs) have been widely detected and pose potential risks to both human and ecosystem health. Since the probation of perfluorooctane sulfonate (PFOS) by the Stockholm Convention, perfluorooctanoate (PFOA) has frequently been used as a chemical intermediate and processing aid. Owing to a lack of effective treatment technologies for PFOA, surrounding environments have been highly affected. Previous studies by our group have reported elevated PFOA levels in the Xiaoqing River, which receives sewage from a major fluorochemical manufacturer in northern China. To further explore the transport, flux, and ecological risk of the perfluorooctanoate in the river, this study conducted a 2-year sampling campaign of surface water from 2014 to 2015. An extremely high PFOA concentration (mean: 62.3 μg L−1) was observed for the Xiaoqing River in comparison with other studies. The highest average concentration and flux of PFOA were recorded in the autumn and summer, respectively. With data on selected hydrological parameters and cross-sections, PFOA concentrations were modeled using DHI MIKE 11. To explore the current loads and environmental capacity of PFOA, two scenarios (i.e., emissions based on observed concentrations and on the predicted no-effects concentration, PNEC) were set. The simulation results based on observed data showed that PFOA loads in the Xiaoqing River were 11.4 t in 2014, and 12.5 t in 2015. Based on the PNEC, the environmental carrying capacity of PFOA was estimated to be 13.9 t in 2014, and 13.8 t in 2015. The current loads of PFOA were found to approach the maximum environmental carrying capacity. Relatively high risks around both the fluorine industrial park (FIP) and estuary area were identified. In comparison with other suggested guidelines, threats to the ecological status of the river would be severe, which suggests that stringent management and emission criteria are needed for this industry.

Raman spectroscopy has been widely used for quantitative analysis in biomedical and pharmaceutical applications. However, the signal-to-noise ratio (SNR) of Raman spectra is always poor due to weak Raman scattering. The noise in Raman spectral dataset will limit the accuracy of quantitative analysis. Because of high correlations in the spectral signatures, Raman spectra have the low-rank property, which can be used as a constraint to improve Raman spectral SNR. In this paper, a simple and feasible Raman spectroscopic analysis method by Low-Rank Estimation (LRE) is proposed. The Frank-Wolfe (FW) algorithm is applied in the LRE method to seek the optimal solution. The proposed method is used for the quantitative analysis of pharmaceutical mixtures. The accuracy and robustness of Partial Least Squares (PLS) and Support Vector Machine (SVM) chemometric models can be improved by the LRE method.

Perfluoroalkyl acids (PFAAs) are ubiquitous in the global environment, even in remote regions. With increasing production and application of PFAAs in China, their distribution patterns have been widely reported, however with less attention to inland northwestern regions. Long-range transport and direct releases from local activities have been regarded as the main reasons for PFAAs distribution in such a remote area. To identify and quantify the contributions of different sources to PFAAs occurrences, an investigation was conducted in the Tianchi lake, nature reserve. A total of 20 water samples, 8 soil, 4 sediment and 10 fresh snow samples were collected and analyzed in 2015. The mean PFAAs concentrations were 3.38 ng L−1 in surface water, 1.06 ng g−1 dw in soil, 0.53 ng g−1 dw in sediment, and 3.31 ng L−1 in fresh snow, respectively. High levels of PFAAs were observed in surface water (15.41 ng L−1) from Western Tianchi pond and surface snow (14.24 ng L−1) from the site near a ski resort around Tianchi Lake indicating potential pollution by local human activities. The correlation between individual concentrations among water, soil and snow indicated the snow deposition as an important source. Although with limited sample size, principal component analysis associated with multiple linear regression (PCA-MLR) and positive matrix factorization (PMF) analyses have identified two major sources, which are characterized as tourism activities with dominance of perfluorooctanoic acid (PFOA) and long-range transport with abundant perfluorobutanoic acid (PFBA). Their contributions to total levels were 41% and 52%, respectively. These two sources contributed differently to the PFAAs presences in Tianchi and Western Tianchi Lakes. Source analysis indicates that the western Tianchi lake with a relatively small catchment was affected mainly by local activities.

We theoretically propose a new approach to obtain high-spectral-resolution sum frequency generation (SFG) vibrational spectra using intrapulse interference. By introducing a π-step phase modulation to the broadband 800 nm pulse, the broadband 800 nm laser pulse splits into two distinguishable pulses in the time domain with a fixed time delay. The resolution of the intrapulse interference SFG can be better than 1 cm−1 and is limited only by the spectral resolution of the spectrometer. This approach can accurately retrieve the amplitude and the relative phase of vibrational peaks. Additionally, the sensitivity of SFG is enhanced by adopting femtosecond IR and femtosecond visible pulses.

Potassium represents one of the most crucial minerals in infant formula that supports healthy growth and development of infants. Here, a novel strategy for the real-time quantification of potassium in infant formula samples is introduced. Using laser-induced breakdown spectroscopy (LIBS) in a data-driven approach, a modified random frog algorithm (MRFA) is adopted in a higher-density discrete wavelet transform (HDWT) domain for the selection of the most important features related to potassium, which is named as DD-LIBS. In DD-LIBS, the HDWT oversamples the LIBS signals in both time and frequency domains by a factor of two, enhancing the spectral expandability in an approximately shift-invariant way. The MRFA is thus capable of isolating the features of potassium with experience accumulated from the collected LIBS data. Such pretreatment combined with a partial least squared (PLS) model can significantly suppress the uncontrolled shift and broadening effects on multivariate calibration, improving the capability of LIBS for accurate quantification of potassium. The present work demonstrates the feasibility of DD-LIBS for the quantification of potassium content of 90 commercial infant formula samples. A satisfactory result illustrates DD-LIBS as a feasible tool for real-time analysis of potassium content with little sample preparation. This strategy may be well extended to other element detection in the presence of uncontrolled interference.

Detection of Circulating tumor cells (CTCs) plays vital role in tumor diagnosis and dynamic assessment in various tumor spectrum. While, CTC detection in pediatric brain tumor, the most occurred solid tumor in children was still underway. Developing a highly efficient CTC capturing system for pediatric brain tumor will be certainly of great importance in clinical practice. In this study, a novel CTC system consisting high-sensitivity and multisit immunomagnetic liposome was constructed. Validation and the efficiency of this system in capturing CTCs were measured in both in vitro and in vivo. The association of the number of CTCs with clinical characters were further analyzed. The results showed that CTCs were successfully isolated by IMLs. CTCs were isolated from CSF and blood samples of 24 cases with brain tumors. It was found that the number of CTCs in CSF was significant higher than that from the blood and the number of CTCs in tumors was significantly higher than the normal control. The level of CTCs in CSF was not related to the tumor stage, instead, related to the type and location of the tumor. Therefore, IMLs isolating CTC from CSF combined immunofluorescence assay of anti-tumor markers can serve as a novel method for the identification of CTCs in CSF from children with brain tumor. As a minimally invasive biopsy, this technique is of important clinical significance in diagnosis and efficacy assessment for brain tumors in children.

Raman spectral imaging has been widely used as a very important analytical tool in various fields. For obtaining the high spectral signal-to-noise ratio Raman images, the long integration time is necessary, which is placing a limit on the application of Raman spectral imaging. We introduce a simple and feasible numerical method of the Three-dimensional Low Rank Estimation (3D-LRE), which can speed up the data acquisition process of the Raman spectral imaging. The spectral signal-to-noise ratio of the Raman images can be increased by over 75 times and the speed of the data acquisition can be improved by over 30 times. By combining with line-scan or multifocus-scan techniques, the Raman images can be obtained in a few seconds.