Search

Ultrasound sound-speed tomography (USST) is a promising technology for breast imaging and breast cancer detection. Its reconstruction is a complex non-linear mapping from the projection data to the sound-speed image (SSI). The traditional reconstruction methods include mainly the ray-based methods and the waveform-based methods. The ray-based methods with linear approximation have low computational cost but low reconstruction quality; the full wave-based methods with the complex non-linear model have high quality but high cost. To achieve both high quality and low cost, we introduced traditional linear approximation as prior knowledge into a deep neural network and treated the complex non-linear mapping of USST reconstruction as a combination of linear mapping and non-linear mapping. In the proposed method, the linear mapping was seamlessly implemented with a fully connected layer and initialized using the Tikhonov pseudo-inverse matrix. The non-linear mapping was implemented using a U-shape Net (U-Net). Furthermore, we proposed the Tikhonov U-shape net (TU-Net), in which the linear mapping was done before the non-linear mapping, and the U-shape Tikhonov net (UT-Net), in which the non-linear mapping was done before the linear mapping. Moreover, we conducted simulations and experiments for evaluation. In the numerical simulation, the root-mean-squared error was 6.49 and 4.29 m/s for the UT-Net and TU-Net, the peak signal-to-noise ratio was 49.01 and 52.90 dB, the structural similarity was 0.9436 and 0.9761 and the reconstruction time was 10.8 and 11.3 ms, respectively. In this study, the SSIs obtained with the proposed methods exhibited high sound-speed accuracy. Both the UT-Net and the TU-Net achieved high quality and low computational cost.

Objective To explore the application value of breast cancer tumor markers tissue polypeptide specific antigen (TPS), carbohydrate antigen 15-3 (CA15-3), carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125) detection alone or in combination for the monitoring of distant metastasis of breast cancer. Method The clinical data of 389 female breast cancer patients admitted to Tianjin Medical University Cancer Institute and Hospital from January 2016 to March 2017 were retrospectively analyzed. Serum levels of TPS, CA125, CA15-3, and CEA were compared to analyze their significance in prediction distant metastasis of breast cancer. The patients were divided into the distant metastatic group and the non-metastatic group according to whether the patients had distant metastasis. The non-metastatic group was divided into the control group and the occult metastasis group according to whether distant metastases occurred in 3 years after treatment. Result The receiver operating characteristic curve analysis revealed that all four markers had the diagnostic value in distant metastasis of breast cancer (AUCTPS = 0.754, AUC15-3 = 0.821, AUCCEA = 0.755, AUCCA125 = 0.651) and in occult metastasis in 3 years after treatment (AUCTPS = 0.751, AUC15-3 = 0.744, AUCCEA = 0.725, AUCCA125 = 0.661). To estimate whether the discrimination ability could be improved by marker panels, we established marker panels composed of TPS, CA125, CA15-3, and CEA. To discriminate distant metastasis from non-distant metastasis, the diagnostic ability of different panels composed of TPS, CA125, CA15-3 and CEA did not show significant difference compared with single CA15-3 (P > 0.05). To discriminate occult metastasis from the control group, no significant difference was shown in AUC between marker panels and single marker (P > 0.05). However, the sensitivity was improved when the marker-panels were used overall. Conclusion All tumor markers have abilities in prediction of distant metastasis of breast cancer. The combined detection of the markers is more valuable than using single tumor marker in improving sensitivity. Two markers' panels are more suitable for the prediction of distant metastasis of breast cancer than three or four makers' panels with the similar sensitivity and AUC.

Devising new versatile catalytic systems for the efficient removal of chlorinated environmental pollutants from water has enormous implications for the environment and human health. By combining the advantages of both electrochemistry and nanotechnology, here we report a conceptually new, general approach of electrochemical-driven nanoparticulate catalysis for highly efficient dehalogenation of organic chlorides. By implementing this strategy, a continuous-flow removal of 4-chlorophenol was rapidly achieved with 100% of dechlorination efficiency within 120 min, and importantly, the dechlorination product phenol could further undergo hydrogenation reaction to completely transform into the mixture of cyclohexanone and cyclohexanol, significantly better than any reported catalytic methods. The essence of activation mechanism was attributed to the electric field-driven nanoparticles for activating the electrogenerated H2 to make numerous reactive species (e.g., atomic hydrogen) and for promoting direct electron transfer on the particles surface, thereby efficiently enabling their fast reactions with the adjacent pollutants. By conducting cyclic voltammetry and atomic-hydrogen quenching investigations, we first showed the direct and indirect reduction of chlorinated environmental pollutants in the voltammogram and provided a new evidence for the presence of these two mechanisms in the dehalogenation process. This work provides the first insight into electrochemical-driven nanoparticulate catalysis for dehalogenation of chlorinated environmental pollutants, showing a promising application for the remediation of these contaminants in water.

Outbreaks of Pseudorabies (PR) by numerous highly virulent and antigenic variant Pseudorabies virus (PRV) strains have been causing severe economic losses to the pig industry in China since 2011. However, current commercial vaccines are often unable to induce thorough protective immunity. In this study, a TK/gI/gE deleted recombinant PRV expressing GM-CSF was developed by using the HDR-CRISPR/Cas9 system. Here, a four-sgRNA along with the Cas9

2,3-Indolinedione derivatives have been identified as a novel class of promising agents for cancer treatment. In this study, eighteen 2,3-indolinedione derivatives were designed and synthesized, and their anticancer activities against mantle cell lymphoma (MCL) cells were evaluated. Most of them exhibited significant antiproliferative activity against the tested cell lines, and compound K5 was the most potent (MCL cellular IC50 = 0.4–0.7 μM). Further, compound K5 could induce cell apoptosis and cell cycle arrest in G2/M phase. Additionally, the results of drug-likeness analysis demonstrated that these novel 2,3-indolinedione derivatives could have potential as novel treatment strategies for MCL.

The Permian Lucaogou Formation in the Jimusaer Sag of the southeastern Junggar Basin in China is an uncommon set of mixed sedimentary rocks. The mixed sediment content of the Lucaogou Formation is unusual due to the large amounts of tuffaceous material, which makes the system more complex than the commonly mixed siliciclastic-carbonate rocks. In this study, the volcanic material acts as a third end-member component in a multi-source mixed sedimentary system. Therefore, a new type of mixed siliciclastic-carbonate-tuffaceous rocks has been introduced. Methods including core observations, thin section analysis, grain size measurements, and X-ray diffraction are used to investigate the characteristics of mineral components, sedimentary structures and lithological assemblages in upper and lower sections of the formation. These analyses are then used to determine the lateral distribution area of mixed sedimentation. Sedimentary mixing processes originally described for siliciclastic-carbonate systems are used and expanded here for the multi-source mixed rocks in a saline lacustrine basin. Controlling factors on mixed sedimentation included climate change, lake level fluctuation, tectonic activity and sediment supply rate mentioned in previous studies, as well as variations of energy levels in different parts of the lake. Mixed-depositional models for the lower and upper sections of the Lucaogou Formation in saline lacustrine basin have been established, respectively.

In this study, we examined the effects of different salt stress application methods on the Lactiplantibacillus plantarum LIP-1 freeze-drying survival rate. The application of salt stress during the stationary phase significantly improved Lactiplantibacillus plantarum LIP-1 freeze-drying survival rates (P 0.05). The indirect application of salt stress via phosphate-buffered saline containing 0.4 mol/L NaCl (NB group) led to significantly higher freeze-drying survival rates compared to when salt stress was directly applied (NA group: the concentration of NaCl is 0.4 mol/L) (P 0.05). Following exposure to salt stress, Lactiplantibacillus plantarum LIP-1 cells exuded excessive Na

The physical mechanisms responsible for hydrocarbon migration in carrier beds are well understood. However, secondary migration is one of poorly understood facets in petroleum system. The Carboniferous Donghe sandstone reservoir in the Tarim Basin's Hudson oilfield is an example of a secondary (or unsteady) reservoir; that is, oil in this reservoir is in the process of remigration, making it a suitable geologic system for studying hydrocarbon remigration in carrier beds. Experimental methods including grains containing oil inclusions (GOI), quantitative grain fluorescence (QGF) and quantitative grain fluorescence on extract (QGF-E) -- together with the results from drilling, logging and testing data -- were used to characterize the nature of oil remigration in the Donghe sandstone. The results show that (1) significant differences exist between paleo- and current-oil reservoirs in the Donghe sandstone, which implies that oil has remigrated a significant distance following primary accumulation; (2) due to tectonic inversion, oil remigration is slowly driven by buoyancy force, but the oil has not entered into the trap entirely because of the weak driving force. Oil scarcely enters into the interlayers, where the resistance is relatively large; (3) the oil-remigration pathway, located in the upper part of the Donghe sandstone, is planar in nature and oil moving along this pathway is primarily distributed in those areas of the sandstone having suitable properties. Residual oil is also present in the paleo-oil reservoirs, which results in their abnormal QGF-E. A better understanding of the characteristics of oil remigration in the Donghe sandstone in the Hudson oilfield can contribute to more effective oil exploration and development in the study area.

Fully homomorphic encryption (FHE) is a technique enabling processing to be performed directly on encrypted data in a commercial cloud environment, thereby preserving privacy. Large integer multiplication is the most time-consuming operation during the FHE. Concerning this issue, this paper proposes an operands merging method of the number theoretic transform (NTT) multiplication butterfly unit. By using the operands merging method and a fast modulo method, the operands of the radix-16 units are reduced to 43.8%. The hardware architecture of the NTT radix-16 unit is designed and implemented. The proposed design has been synthesized using 90-nm process technology and Xilinx Kintex UltraScale+ FPGA. The results show that the maximum frequency of the circuit is 600 MHz at the cost of 243k gates and 144 mW and 430 MHz at the cost of 19.6k CLB LUTs, 11.5k CLB registers, and 1.2k CARRY8 respectively. The multiplier implementation results also show that the optimization methods improve the area requirements and performance.

Accurately monitoring blood glucose in real-time is highly required for diabetes. Utilizing membrane to realize fast separation of a trace of blood is significant for accurately testing blood glucose. In this work, we designed a Janus membrane with thin film composite structure by electrospinning polyurethane (PU) on Ca3(PO4)2-coated nylon mesh. This Janus membrane exhibited directional liquid transport performance and liquid wastage reduction during separation through optimizing the surface wettability, pore parameters and asymmetric structures of membrane. When a trace of water with volume as small as 3 μL was dipped on the hydrophobic side with pore size of around 1.1 μm, this water droplet could easily penetrate through the Janus membrane within 2.9 s under only gravity and liquid wastage reduction was achieved at the same time (D2/D1 = 1.27), suggesting an excellent liquid transportation performance. The blood glucose meter integrated with this Janus membrane could efficiently remove red blood cells from 10 μL blood within 7.2 s. As a result, the sensitivity of the blood glucose meter increased by 4.5%.

Summary Advanced oxidation processes (AOPs) represent one of the most powerful strategies for dealing with the ever-growing water pollution problem. However, their application is hindered by high cost and risk of handling catalysts and sacrificial chemicals, as well as the low efficiency of electron transfer to peroxides. Here, we report that the addition of nanoparticles (NPs) into the electric field facilitates electron transfer on the surface of NPs to generate reactive oxidizing species (ROS) without the use of sacrificial chemicals. Electrostatic induction can drive the charge separation of individual NPs. Because of the polarization, NPs are turned into numerous bipolar electrodes, which activate the electrogenerated H2 and O2 to form ROS, thereby efficiently enabling their fast reaction with the adjacent pollutants. This discovery may provide a general methodology that is fundamental for AOPs and has wide applications for real-life water remediation.

Tight sandstone gas from coal-measure source rock is widespread in China, and it is represented by the Xujiahe Formation of the Sichuan Basin and the Upper Paleozoic of the Ordos Basin. It is affected by planar evaporative hydrocarbon expulsion of coal-measure source rock and the gentle structural background; hydrodynamics and buoyancy play a limited role in the gas migration-accumulation in tight sandstone. Under the conditions of low permeability and speed, non-Darcy flow is quite apparent, it gives rise to gas-water mixed gas zone. In the gas displacing water experiment, the shape of percolation flow curve is mainly influenced by core permeability. The lower the permeability, the higher the starting pressure gradient as well as the more evident the non-Darcy phenomenon will be. In the gas displacing water experiment of tight sandstone, the maximum gas saturation of the core is generally less than 50% (ranging from 30% to 40% and averaging at 38%); it is similar to the actual gas saturation of the gas zone in the subsurface core. The gas saturation and permeability of the core have a logarithm correlation with a correlation coefficient of 0.8915. In the single-phase flow of tight sandstone gas, low-velocity non-Darcy percolation is apparent; the initial flow velocity (Vd) exists due to the slippage effect of gas flow. The shape of percolation flow curve of a single-phase gas is primarily controlled by core permeability and confining pressure; the lower the permeability or the higher the confining pressure, the higher the starting pressure (0.02–0.08 MPa/cm), whereas, the higher the quasi-initial flow speed, the longer the nonlinear section and the more obvious the non-Darcy flow will be. The tight sandstone gas seepage mechanism study shows that the lower the reservoir permeability, the higher the starting pressure and the slower the flow velocity will be, this results in the low efficiency of natural gas migration and accumulation as well as low gas saturation. The laboratory modeling on gas migration accumulation mechanism in coal-measure tight sandstone can provide a theoretic foundation to reveal the tight sandstone gas enrichment regularity, evaluation of prospecting area, and the study of development mechanism.

A pyrolysis-vapor generation procedure to determine cadmium by atomic fluorescence spectrometry has been established. Under fast pyrolysis, cadmium ion can be reduced to volatile cadmium species by sodium formate. The presence of thiourea enhanced the efficiency of cadmium vapor generation and eliminated the interference of copper. The possible mechanism of vapor generation of cadmium was discussed. The optimization of the parameters for pyrolysis–chemical vapor generation, including pyrolysis temperature, amount of sodium formate, concentration of hydrochloric acid, and carrier argon flow rate were carried out. Under the optimized conditions, the absolute and concentration detection limits were 0.38 ng and 2.2 ng ml − 1 , respectively, assuming that 0.17 ml of sample was injected. The generation efficiency of was 28–37%. The method was successfully applied to determine trace amounts of cadmium in two certified reference materials of Environmental Water (GSB07-1185-2000 and GSBZ 50009-88). The results were in good agreement with the certified reference values.

Background We conducted a systematic review and meta-analysis on drug-resistant tuberculosis in China to provide useful data for tuberculosis (TB) surveillance and treatment. Methods Several databases, including PubMed, Embase, and the Chinese Biological Medical Database, were systematically searched between January 1, 1999, and August 31, 2015, using strict inclusion and exclusion criteria. Results The corresponding drug-resistant TB prevalence between the new and previously treated cases was significantly different in almost all of the economic regions. The Eastern coastal region is the most developed economic region with the lowest total drug-resistant TB prevalence (any drug resistance: 28%; 95% confidence interval [CI], 25%-32%; multidrug resistance: 9%; 95% CI, 8%-12%) and the lowest number of new cases (any drug resistance: 21%; 95% CI, 19%-23%; multidrug resistance: 4%; 95% CI, 3%-5%). The Northwest is the least developed area with the lowest drug-resistant TB prevalence for previously treated cases (any drug resistance: 45%; 95% CI, 36%-55%; multidrug resistance: 17%; 95% CI, 11%-26%). The prevalence (multidrug and first-line drug resistance) exhibited a downward trend from 1996-2014. The extensively drug-resistant prevalence in China was 3% (95% CI, 2%-5%) in this review. Conclusions Overall, the status of drug-resistant tuberculosis in China is notably grim and exhibits regional epidemiologic characteristics. We are in urgent need of several comprehensive and effective control efforts to reverse this situation.

A novel calixarene ionic liquid functionalized silica material was synthesized by the preparation of a new calixarene monomer and its grafting on mercaptopropyl modified silica gel. The material was characterized by infrared spectra, elemental analysis, and thermogravimetric analysis. To explore the retention mechanism of the stationary phase, linear solvation energy relationships (LSER) equation as an effective mathematical model was used. In addition to this, the distinct separation mechanisms were outlined by selected examples of chromatographic separations in the different modes. In reversed-phase liquid chromatography, this new stationary phase presented specific chromatographic performance when evaluated using alkylbenzenes, PAHs and phenols as solutes. Due to the existing polar functional groups, this stationary phase can also be used in hydrophilic interaction chromatography, six nucleosides and four ginsenosides were separated successfully in hydrophilic mode. Furthermore, anions can be separated on the column in anion exchange mode. Thus, this new material was can be applied as a new kind of mixed-mode stationary phase in liquid chromatography, which allows an exceptionally flexible adjustment of retention and selectivity by tuning the experimental conditions.

The Permian Lucaogou Formation of Jimusaer Sag in the southeast region of the Junggar Basin is a typical area recently attracting tight oil reservoir research efforts in China. Commercial oil has been obtained from many wells in this region. The main lithological formation comprises thick mudstones; two sweet spots exhibiting high porosity and permeability are interbedded in the mudstones. The sweet spots comprise alternating thin layers of silt-fine sandstones, carbonatites, and mudstones. Numerous core samples were analyzed to establish the hydrocarbon generation and storage potential of Lucaogou Formation's lithological units in this region. The test results indicate that although the tight sandstones have a certain hydrocarbon generation potential, mudstones are evidently higher-quality source rocks. The silt-fine sandstones' reservoir quality is best among the three rock types. Biomarker evidence shows the difference between the upper- and the lower-section Lucaogou Formation oil, corresponding to the mudstone layer extracts within the upper and lower sweet spot, respectively. Despite its thickness, the thick-bedded mudstone (average thickness = 80 m) between the upper and lower sweet spots does not appear to contribute to the oil reservoirs. Since the distance between the thick mudstone and the sweet spot is quite large and the entire formation has generally low permeability, migrating from the thick mudstone to the sweet spot is difficult. Hence, oil in the sweet spots can be concluded to be from the adjacent mudstone. To our knowledge, this is the first study reporting this finding.

SFRP1 acts as a well-established inhibitory regulator of the Wnt signaling pathway, whose polymorphisms have been demonstrated to be associated with the risk of inflammation, infection as well as cancer. We verified the hypothesis that single nucleotide polymorphisms (SNPs) within SFRP1 gene are associated with susceptibility and clinical characteristics of tuberculosis disease in a Chinese Han population.Six candidate SNPs were genotyped using MassARRAY method in a case-control design (260 tuberculosis patients and 252 healthy controls). A comprehensive analysis of single locus including the genotypic, allelic frequencies and the genetic models, haplotypic construction as well as gene-gene interaction was conducted to investigate the relationships between SNPs and TB. Significant SNPs were further interrogated in relation to TB clinical features and host inflammatory status.Genotype frequencies of rs4736958 and rs7832767 within SFRP1 gene were significantly different (p=0.011, p=0.008, respectively) between tuberculosis group and control group. Subjects carrying C allele for rs4736958 showed a decreased tuberculosis risk (OR=0.66, 95% CI=0.51-0.87, p=0.003), whereas individuals carrying rs7832767 T allele had a significant increased risk in tuberculosis susceptibility (OR=1.32, 95% CI=1.01-1.74, p=0.046). Genetic model analysis revealed that dominant, co-dominant and recessive models of rs4736958 were associated with decreased susceptibility to tuberculosis (p all0.05), while the recessive and co-dominant models of rs7832767 were related to significantly increased risk for tuberculosis (p all0.05). There was a reduced tuberculosis risk in association with the haplotype CC (representing rs3242 and rs4736958) of SFRP1 (OR=0.73, 95% CI=0.56-0.96, p=0.026). Further stratification analysis indicated that TB patients with genotype CT for rs4736958 were associated with higher CRP concentrations, and heterozygous patients (CT genotype) of rs7832767 trended towards greater ESR levels.SNPs rs4736958 and rs7832767 of SFRP1 gene were significantly associated with tuberculosis susceptibility and might influence the expression levels of inflammatory markers of tuberculosis patients in a Chinese Han population.

The features of pore and throat structure of an unconventional reservoir are very complex due to multiscale pore-throat size and various pore types and thus hard to characterize. In this study, thin sections, field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), granulometry analysis, physical properties measurements, mercury intrusion capillary pressure (MICP) and nitrogen gas adsorption analysis (N2GA) were combined to investigate the pore-throat structures of the Gaotaizi tight siltstone reservoir in the northern Songliao Basin. The results of observation suggest that the pores are composed of intergranular pores, dissolution pores, intercrystalline pores within clay minerals and micro-fractures. The content of calcite cement has some negative effect on porosity. The content and types of clay minerals have some negative influence on petrophysical properties of reservoir as well. MICP and N2GA are combined to get the full-range of pore-throat size distribution. Based on previous studies and the actual situation of the Gaotaizi reservoir, a new classification for pore-throat size has been proposed, including micropore ( ~ 100 nm), mesopore (100 nm ~ 0.625 μm) and macropore (>0.625 μm). On this basis, the contents of pore-throat in different scales have been calculated. The Gaotaizi tight siltstone reservoir has been divided into three types based on the pore-throat structure. There are big differences among the three types of reservoir with respect to the grain size, the content of matrix, the types of diagenetic minerals, the dominant pore types, the pore-throat size distribution and the percentage of pore-throats in different scales. Accordingly, a pore structure model has been constructed for each type of reservoir. In addtion, it has been found that the pore-throat structure has an important effect on the percolation capacity of the tight siltstone reservoir. Porosity and pore-throat radius have a positive correlation with the permeability. Pore-throats in different scales have different impact on the flow characteristics of tight reservoir. The mesopores and macropores make a great contribution to the flow in the reservoir while the micropores and transition pores do not contribute and even have an inhibitional effect. In general, the permeability or the flow characteristics of the tight siltstone reservoir are mostly controlled by the pore-throats larger than 0.1 μm.

Hydrophilically-modified mesh filter membranes have been widely researched for oil/water separation due to their high permeating flux and excellent separation efficiency. However, the low oil pressure resistance of mesh membrane is a major drawback limiting its practical oil/water separation applications. In this work, we report an ultrathin microporous membrane developed via the decoration of a stainless steel mesh filter with electrospun poly(acrylic acid) grafted poly(vinylidene fluoride) (PAA-g-PVDF) nanofibers. The network structure of the nanofiber layer reduces the pore size of the stainless steel mesh to improve its oil pressure resistance, and simultaneously maintains a high active separation area to preserve the highly permeable feature of the mesh filter membrane. Therefore, this composite membrane exhibits high permeating flux (up to 53574 L m−2 h−1 under gravity) and high oil intrusion pressure (>6000 Pa) at the same time. Satisfactory permeating flux and separation efficiency are achieved in various oil/water separation experiments and multiple operating cycles, which demonstrate the great potential of the membrane for practical oily wastewater treatment applications.

This new study shows for the first time that sodium formate can react with trace arsenic to form volatile species via fast pyrolysis – chemical vapor generation. We found that the presence of thiourea greatly enhanced the generation efficiency and eliminated the interference of copper. We studied the reaction temperature, the volume of sodium formate, the reaction acidity, and the carried argon rate using nondispersive atomic fluorescence spectrometry. Under optimal conditions of T = 500 °C, the volumes of 30% sodium formate and 10% thiourea were 0.2 ml and 0.05 ml, respectively. The carrier argon rate was 300 ml min − 1 and the detection limit and precision of arsenic were 0.39 ng and 3.25%, respectively. The amount of arsenic in soil can be directly determined by adding trace amount of hydrochloric acid as a decomposition reagent without any sample pretreatment. The method was successfully applied to determine trace amount of arsenic in two soil-certified reference materials (GBW07453 and GBW07450), and the results were found to be in agreement with certified reference values.

A novel composite charged mosaic membrane (CCMM) was prepared via interfacial polymerization (IP) of polyamine [poly(epichlorohydrin amine)] and trimesoyl chloride (TMC) on the polyethersulfone (PES) support. Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and water contact angle analysis were applied to characterize the resulted CCMM. The FT-IR spectrum indicates that TMC reacts sufficiently with polyamine. ESEM and AFM pictures show that the IP process produces a dense selective layer on the support membrane. The water contact angle of the CCMM is smaller than that of the substrate membrane because of the cross-linked hydrophilic polyamine network. Several factors affecting the IP reaction and the performance of the CCMM, such as monomer concentration, reaction time, pH value of aqueous phase solution and post-treatment, were studied. The pure water flux of the optimized CCMM is 14.73 L·m−2·h−1·MPa−1 at the operating pressure of 0.4 MPa. The values of separation factor a for NaCl/PEG1000/water and MgCl2/PEG1000/water are 11.89 and 9.96, respectively. These results demonstrate that CCMM is promising for the separation of low-molecular-weight organics from their salt aqueous solutions.