Dataset Condensation via Expert Subspace Projection.

The rapid growth in dataset sizes in modern deep learning has significantly increased data storage costs. Furthermore, the training and time costs for deep neural networks are generally proportional to the dataset size. Therefore, reducing the dataset size while maintaining model performance is an urgent research problem that needs to be addressed. Dataset condensation is a technique that aims to distill the original dataset into a much smaller synthetic dataset while maintaining downstream training performance on any agnostic neural network. Previous work has demonstrated that matching the training trajectory between the synthetic dataset and the original dataset is more effective than matching the instantaneous gradient, as it incorporates long-range information. Despite the effectiveness of trajectory matching, it suffers from complex gradient unrolling across iterations, which leads to significant memory and computation overhead. To address this issue, this paper proposes a novel approach called Expert Subspace Projection (ESP), which leverages long-range information while avoiding gradient unrolling. Instead of strictly enforcing the synthetic dataset's training trajectory to mimic that of the real dataset, ESP only constrains it to lie within the subspace spanned by the training trajectory of the real dataset. The memory-saving advantage offered by our method facilitates unbiased training on the complete set of synthetic images and seamless integration with other dataset condensation techniques. Through extensive experiments, we have demonstrated the effectiveness of our approach. Our method outperforms the trajectory matching method on CIFAR10 by 16.7% in the setting of 1 Image/Class, surpassing the previous state-of-the-art method by 3.2%.

Regional Differences and Influencing Factors of Allocation Efficiency of Rural Public Health Resources in China.

In the face of increasingly growing health demands and the impact of various public health emergencies, it is of great significance to study the regional differences in the allocation efficiency of the rural public health resources and its improvement mechanism. In this paper, the game competition relationship is included in the evaluation model, and the game cross-efficiency model is used to measure the allocation efficiency of the rural public health resources in 31 provinces of China from 2008 to 2017. Then, the Theil index model and the Gini index model are applied in exploring the regional differences in the allocation efficiency of rural public health resources and its sources. Finally, the bootstrap truncated regression model is used to analyze the influencing factors of the allocation efficiency of the rural public health resources in China. The results show that, first, the total allocation efficiency level of the rural public health resources in China from 2008 to 2017 is relatively low, and it presents a U-shaped trend, first falling and then rising. Second, the changing trend of the allocation efficiency of the rural public health resources in the eastern, central, and western regions of China is similar to that in the nationwide region, and it shows a gradient trend that "the allocation efficiency in the eastern region is high, the allocation efficiency in the western region is low, and the allocation efficiency in the Central region is at the medium level". However, the gap among the three regions is continually narrowing. Third, the calculation results of the Theil index and the Gini index show that intra-regional differences are the major source of the regional differences in the allocation efficiency of the rural public health resources in China, and the inter-regional differences demonstrate an expansion trend. Finally, the improvement of the education level and the social support level will generally improve the allocation efficiency of the rural public health resources in China and its three regions. The increased governmental financial support and urbanization level will reduce the allocation efficiency of the rural public health resources in China and its three regions. The economic development level, the living conditions and the population density are the important influencing factors of the allocation efficiency differences of the rural public health resources in the three regions. Therefore, on the basis of ensuring the increase of the total supply of the rural public health resources, more attention should be paid to the improvement of the allocation efficiency. Moreover, on the basis of continually narrowing the inter-regional differences among the eastern, central, and western regions, more attention should be paid to the intra-regional differences of the allocation efficiency of the rural public health resources among the different provinces. The various economic and social policies should be constantly optimized to jointly improve the allocation efficiency of the rural public health resources.

Low-Temperature Synthesis of Honeycomb CuP2 @C in Molten ZnCl2 Salt for High-Performance Lithium Ion Batteries.

Phosphorus-rich metal phosphides have very high lithium storage capacities, but they are difficult to prepare. A low-temperature phosphorization method based on Mg reducing PCl3 in ZnCl2 molten salt at 300 °C is developed to synthesize phosphorus-rich CuP2 @C from a Cu-MOF derived Cu@C composite. Abnormal oxidation of Cu by Zn2+ in the molten salt is observed, which leads to the porous honeycomb nanostructure and homogeneously distributed ultrafine CuP2 nanocrystals. The honeycomb CuP2 @C exhibits excellent lithium storage performance with high reversible capacity (1146 mAh g-1 at 0.2 A g-1 ) and superior cycling stability (720 mAh g-1 after 600 cycles at 1.0 A g-1 ), showing the promising application of P-rich metal phosphides in lithium ion batteries.

Analysis of the Agricultural Economy and Agricultural Pollution Using the Decoupling Index in Chengdu, China.

The development of the agricultural economy has brought the agricultural pollution, and agricultural pollution has restrained the growth of the agricultural economy and endangered public health. Since the Economic Reform opened up, China has promulgated many policies that have benefited farmers, developed the agricultural economy, and improved agricultural material levels. However, the growth in the agricultural economy has also resulted in significant environmental pollution from pesticides, agricultural fertilizers and agricultural plastic film. Agricultural pollution can affect public health, therefore it is necessary to study the relationship between agricultural economy and agricultural pollution. In this paper, the relationship between the agricultural economy and agricultural pollution is studied by using decoupling index method, taking Chengdu, Sichuan Province, China as an example, and verified by the data of 2008-2017 years of Chengdu. It was found that the decoupling index for pesticide use and per capita gross agricultural production showed "strong decoupling" ideal states in six years. From 2009-2017, the value of it increased from 0.065743-1.597385, and its decoupling state gradually transited to stable strong decoupling. The chemical fertilizer use was found to have a "strong decoupling" ideal state in five years. The value of it decreased from 1.028854-(-0.512702), while its state gradually changed to strong decoupling. However, agricultural plastic film only has one "strong decoupling" state with its value of decoupling index changed from -0.380824-(-0.250250). The increased use of plastic film has resulted in increased agricultural pollution. The research results show that growing with the development of Chengdu's agricultural economy, the use of pesticides and fertilizers has been decreasing. Chengdu's agricultural economy and agricultural pollution were found to have a healthy and coordinated development. The development of agricultural economy has not caused much damage to the agricultural environment. In addition, with the decline of agricultural pollution, public health problems will also be reduced.

Analysis of perfluorooctane sulfonate and perfluorooctanoic acid with a mixed-mode coating-based solid-phase microextraction fiber.

A novel mixed-mode coating-based solid-phase microextraction (SPME) fiber was prepared by chemical bonding dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride and 3-(trimethoxysilyl)-1-propanamine, the sol-gel precursors, on an anodized Ti wire, aiming to effectively adsorb perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). The anodized Ti wire with uniform TiO2 nanotube arrays provides high mechanical strength and strong adhesion to the mixed-mode coating. The prepared fiber shows excellent organic solvent stability due to the covalent bonding between the coating and the fiber, and significantly higher extraction efficiency than the commercial fibers, 100 µm polydimethylsiloxane and 85 µm polyacrylate fiber, due to the synergistic extraction effects of the coating functional groups. Good linearity (R(2)=0.9994 for PFOS, R(2)=0.9992 for PFOA) was obtained with detection limits of 2.5 and 7.5 pg mL(-1) for PFOS and PFOA, respectively. Recoveries were in the range of 88%-102%. The proposed method was successfully applied in the analysis of PFOS and PFOA in a local river with the results of 0.05 and 0.06 ng mL(-1), respectively.

Development of a highly robust solid phase microextraction fiber based on crosslinked methyl methacrylate-polyhedral oligomeric silsesquioxane hybrid polymeric coating.

A novel solid-phase microextraction (SPME) fiber was prepared by polymerization of an organic-inorganic hybrid polymeric coating on an anodized and derived Ti wire, and applied for the analysis of polycyclic aromatic hydrocarbons from environmental samples followed by high performance liquid chromatography (HPLC) analysis. A polyhedral oligomeric silsesquioxane (POSS) reagent containing methacryl substituent groups was used as an organic-inorganic hybrid cross-linker, and copolymerized with methyl methacrylate (MMA) to fabricate the hybrid coating via thermally initiated free radical polymerization in a glass capillary mold. The prepared fiber can be easily withdrawn from the glass capillary mold by controlling the polymerization conditions, especially polymerization solvent. A homogeneous and porous coating with thickness of about 100µm was achieved using ethanol as polymerization solvent at the mass ratio of MMA to POSS as 1:0.5. High chemical and mechanical stability, as well as excellent durability for more than 100 times extractions with almost undiminished extraction efficiency were achieved due to the chemical immobilization and crosslinked hybrid coating. The proposed fiber showed much better extraction performance than the 100µm commercial polydimethylsiloxane fiber for extracting PAHs from aqueous sample. The developed SPME-HPLC method for the determination of PAHs using the MMA-POSS hybrid coating achieved good linearity with good correlation coefficients (R=0.991-0.999) and low detection limits in the range of 0.006 to 0.05ng mL(-1) (S/N=3). The proposed fiber was successfully applied to the extraction of PAHs from environmental water samples with recoveries of 82-104% for river water, 83-103% for pool water, and 79-98% for wastewater, respectively.

A new strategy based on cholesterol-functionalized iron oxide magnetic nanoparticles for determination of polycyclic aromatic hydrocarbons by high-performance liquid chromatography with cholesterol column.

This study reported for the first time the use of cholesterol-functionalized magnetic nanoparticles (Fe3O4@SiO2@Chol) for the determination of polycyclic aromatic hydrocarbons (PAHs) in traditional Chinese medicine samples (TCMs) by high performance liquid chromatography (HPLC) coupled with fluorescence detection. The method was efficient, environmentally friendly, and fast. The solvent consumption of the proposed column is only half of the conventional column but with higher efficiency. Influencing factors, including sorbent amount, desorption solvent, sample volume and extraction time, were investigated in detail. Under the optimum conditions, good linearity (R(2)>0.991) was obtained over the range of 5-400 ng g(-1), with limits of detection (LOD) 0.75, 0.50, 1.0, 0.56, 0.60, 0.84 and 0.80 ng g(-1) for anthracene, fluoranthene, pyrene, chrysene, benzo[a]anthracene, benzo(b)fluoranthene and benzo(k)fluoranthene, respectively.

Evaluation of metal-organic framework 5 as a new SPE material for the determination of polycyclic aromatic hydrocarbons in environmental waters.

Metal-organic frameworks, a new class of materials with high surface area and great porosity, have been widely applied in gas sorption. It is generally known that metal-organic framework 5 cannot be applied in aqueous phase since it is water sensitive. However, this work reveals that the derived material of metal-organic framework 5 is a good SPE sorbent that can be applied to aqueous phases. Metal-organic framework 5 was prepared and used as a SPE sorbent for the determination of polycyclic aromatic hydrocarbons in environmental matrices coupling with HPLC. The water treatment induced changes in the properties were investigated in detail. Even though metal-organic framework 5 is conversed to a second phase after water treatment, it still shows high extraction ability. Under the optimized experimental conditions, good sensitivity levels were achieved with low LODs ranging from 0.4 to 4.0 ng L(-1) and a linearity of 0.004-20 µg L(-1) (R(2) > 0.996) for the investigated polycyclic aromatic hydrocarbons. The method has been validated in the analysis of real water samples with recoveries in the range of 80.2-120.2% and RSDs in the range of 0.5-11.7%.

Development of octadecyl-functionalized-nanotubular TiO2/Ti wire solid-phase microextraction fiber.

An octadecyl-functionalized solid-phase microextraction (SPME) fiber was prepared by sol-gel technology with an anodized Ti wire as the substrate and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (C(18)-TMS) and tetraethoxysilane (TEOS) as sol-gel precursors. The anodized Ti wire has high mechanical strength and has numerous titanol groups on its surface for sol-gel reactions, consequently offering better performances than the commercial fragile fused silica substrate. The C(18)-TMS/TEOS sol-gel coated fiber has good thermal stability and stability against organic solvents. There is no loss in the performance after 100 cycles of exposure to acetonitrile and high temperature (300 °C) in turn. The developed fiber with a very thin (ca. 2 µm) coating thickness exhibits comparable or even superior extraction capability relative to the commercial 100 µm polydimethylsiloxane (PDMS) fiber. Under optimized conditions, the detection limits for the polycyclic aromatic hydrocarbons are in the range of 0.003 to 0.025 µg L(-1) with a linear range from 0.01 to 20 µg L(-1). The proposed method was successfully applied in the analysis of environmental water samples with the recoveries ranging from 85.3 to 101.8%.

Criteria for determining the need for surgical treatment of tricuspid regurgitation during mitral valve replacement.

BACKGROUND: Tricuspid regurgitation (TR) is common in patients with mitral valve disease; however, there are no straightforward, rapidly determinably criteria available for deciding whether TR repair should be performed during mitral valve replacement. The aim of our retrospective study was to identify a simple and fast criterion for determining whether TR repair should be performed in patients undergoing mitral valve replacement. METHODS: We reviewed the records of patients who underwent mitral valve replacement with or without (control) TR repair (DeVega or Kay procedure) from January 2005 to December 2008. Preoperative and 2-year postoperative echocardiographic measurements included right ventricular and atrial diameter, interventricular septum size, TR severity, ejection fraction, and pulmonary artery pressure. RESULTS: A total of 89 patients were included (control, n = 50; DeVega, n = 27; Kay, n = 12). Demographic and clinical characteristics were similar between groups. Cardiac variables were similar between the DeVega and Kay groups. Right atrium and ventricular diameter and ejection fraction were significantly decreased postoperatively both in the control and operation (DeVega + Kay) group (P < 0.05). Pulmonary artery pressure was significantly decreased postoperatively in-operation groups (P < 0.05). Our findings indicate that surgical intervention for TR should be considered during mitral valve replacement if any of the following preoperative criteria are met: right atrial transverse diameter > 57 mm; right ventricular end-diastolic diameter > 55 mm; pulmonary artery pressure > 58 mmHg. CONCLUSIONS: Our findings suggest echocardiography may be used as a rapid and simple means of determining which patients require TR repair during mitral valve replacement.