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The parasite Fasciola hepatica is an important zoonotic parasite. The development of an animal model of F. hepatica's life cycle is critical for studying the biological characteristics of the parasite in snails and mammals. Eggs of F. hepatica of bovine origin were cultured, and metacercariae were obtained after infection of Galba pervia snails. The life cycle system of F. hepatica was initiated in 2 different animals by orally infecting rabbits, SD rats and Kunming mice with the metacercariae. The animals' survival after infection, parasite migration in the animals and pathological damage to the liver were observed. We discovered that rabbits died due to acute suppurative hepatitis 60–69 days after infection, and eggs were found in the feces on day 63 of infection. The liver of SD rats showed punctate lesions on day 3 of infection, and further changes occurred as the infection progressed. However, liver repair was observed at week 9. SD rats survived for more than a year after infection and continued the F. hepatica life cycle. The liver lesions in Kunming mice after infection were similar but more severe than those in SD rats. Death was observed on the 31st post-infection day. We discovered that while rabbits, SD rats and Kunming mice can all be used as animal models of F. hepatica, SD rats are more suitable experimental animals in terms of tolerance and pathological response.

Heat generation in integrated circuits (ICs) has become a severe issue, which limits the utilization of miniaturized semiconductor devices in high-density 3-D IC technologies. Herein, Al₂O₃ was doped in ZrO₂ thin films by plasma-enhanced atomic layer deposition (PEALD) to enhance their antiferroelectric (AFE) characteristics for highly reliable electrocaloric (EC) cooling applications. The cycling endurance in AFE behaviors of the Al:ZrO₂ thin films under a high electric field of 5 MV/cm was significantly improved because of the enlargement of the energy bandgap with high resistance in trap-induced leakage current. Hence, the reliability of the EC effect of the 1% Al:ZrO₂ thin film was examined with a negligible change in adiabatic temperature change (Δ T) of 2.6% after a cycling endurance test of 10⁶ cycles. With the competitive cycling reliabilities in AFE and EC behaviors, devices with optimized Al₂O₃-incorporated ZrO₂ thin films show significant potential for future nanoscale cooling systems in chip-level ICs.

In this study, the antiferroelectric (AFE) and electrocaloric (EC) characteristics of lead-free titanium (Ti)-doped zirconia (ZrO2) thin films deposited via high-power impulse magnetron sputtering (HiPIMS) were investigated. The argon-to-oxygen ratio was initially optimized during deposition to obtain a more stoichiometric ZrO2 film for enhanced antiferroelectricity. Furthermore, enhanced crystallinity was achieved through the incorporation of Ti atoms into ZrO2 thin films as confirmed via grazing incidence X-ray diffraction and high-resolution transmission electron microscopy. For metal-insulator-metal capacitors with Ti-doped ZrO2 thin films, the AFE behaviors were significantly improved because of the excellent crystallinity of the tetragonal phase. Based on a fast polarization response and robust fatigue resistance under a 106-cycle endurance test, the EC effect was successfully explored, and an adiabatic temperature change (ΔT) of −14.8 K was realized. With competitive EC properties, Ti-doped ZrO2 thin films deposited via HiPIMS are proposed as promising candidates for use in future cooling systems.

Previously, organic-ionic crystal phase transition materials have mainly focused on mono- or divalent organic amine cations, while higher valent amine cations have rarely been introduced. Here, we have selected a ring-shaped trivalent organic amine, triethylenetriamine, in order to construct a high-Tc phase transition material, triethylenetriammonium trichloride ([HTETA]3+ 3[Cl]−).

Temperature-dependent physical switching materials have been of wide concern for materials chemists. Among them, switchable dielectric perovskite materials have shown huge application potential in the fields of sensing, information storage, and electronics. In particular, for better practical application, obtaining dual-phase-change switching materials with a high phase transition temperature (Tc) is still a worthwhile issue to study. In this work, we synthesized chiral hybrid organic inorganic perovskites, namely, (R)-, (S)- and (rac)-N,N-dimethyl-3-fluoropyrrolidinium (DMFP) CdCl3. The enantiomeric compound undergoes a dual phase transition with a Tc of 460 K and 367 K. Tc significantly increased by 28 K from 411 K of (N,N-dimethyl pyrrolidinium) (DMP) CdCl3 to 439 K of (rac)-DMFP CdCl3. Besides, (R) and (S)-DMFP CdCl3 are the first example of chiral perovskites that show dual Tc with robust switching dielectric characteristics. This work could be a pathway for designing multifunctional chiral perovskite-type switchable materials.

Three-dimensional (3D) organic-inorganic lead halide hybrids have become a hot academic topic because of their various functional properties. However, 3D lead halide hybrid ferroelectrics are still very rare until now. Here, we report a new 3D lead halide perovskite-related ferroelectric, (EATMP)Pb2Br6 [EATMP = (2-aminoethyl)trimethylphosphanium]. Based on nonferroelectric CH3NH3PbBr3, by replacing PbBr6 octahedra with a Pb2Br10 dimer of edge-sharing octahedra as the basic building unit, the expanded 3D lead bromide perovskite analog was formed with the large [EATMP]2+ cations occupying the voids of framework. Notably, (EATMP)Pb2Br6 displays a direct bandgap of 2.81 eV, four polarization directions, and a high Curie temperature (Tc) of 518 K (much beyond that of BaTiO3, 393 K), which is the highest among all reported 3D organic-inorganic hybrid ferroelectrics. Such a high Tc may result from the high rotational energy barrier of cations induced by a larger molecular volume and relatively low crystal symmetry. Our work provides an efficient avenue to construct new 3D organic-inorganic lead halide hybrids and would inspire the further exploration of 3D lead halide ferroelectrics.

1,4-Diazabicyclo[2.2.2]octane (dabco) and its derivatives have been extensively utilized as building units of excellent molecular ferroelectrics for decades. However, the homochiral dabco-based ferroelectric remains a blank. Herein, by adding a methyl (Me) group accompanied by the introduction of homochirality to the [H2 dabco]2+ in the non-ferroelectric [H2 dabco][TFSA]2 (TFSA=bis(trifluoromethylsulfonyl)ammonium), we successfully designed enantiomeric ferroelectrics [R and S-2-Me-H2 dabco][TFSA]2 . The two enantiomers show two sequential phase transitions with transition temperature (Tc ) as high as 405.8 K and 415.8 K, which is outstanding in both dabco-based ferroelectrics and homochiral ferroelectrics. To our knowledge, [R and S-2-Me-H2 dabco][TFSA]2 are the first examples of dabco-based homochiral ferroelectrics. This finding opens an avenue to construct dabco-based homochiral ferroelectrics and will inspire the exploration of more eminent enantiomeric molecular ferroelectrics.

In this work, a sensitive fluorescent sensor for the detection of ciprofloxacin (CIP) was developed by wrapping the surface of CdTe quantum dots (QDs) with molecularly imprinted polymers (MIPs). The MIP@QDs were synthesized via a simple sol–gel method using 3-aminopropyltriethoxysilane (APTES) as the functional monomer and tetraethoxysilane (TEOS) as the crosslinker. The fluorescence emission of the probe was at 643 nm. Linear calibration curves were obtained in the range of 0.5–24 [Formula: see text]M for CIP with the detection limit of 0.23 [Formula: see text]M (S/N[Formula: see text]3). The fluorescent probe was successfully applied to the determination of CIP in seawater samples with the spiked recoveries ranging from 98.2% to 110.6% and the relative standard deviation (RSD) was less than 10.7%. It is the first time that QDs with molecularly imprinted polymers (MIP@QDs) were introduced for separation and detection of CIP in seawater and obtained good specific identification ability and potential practical value.

Purpose To investigate multispectral imaging (MSI) as a novel diagnostic approach for diabetic retinopathy (DR) in clinic. Methods A total of 50 Type-2 diabetic patients (99 eyes) were enrolled in this cross-sectional study. All subjects underwent digital fundus photography (DFP), MSI, and fundus fluorescein angiography. A total exact agreement, sensitivity, specificity, positive predictive value, and negative predictive value of no DR/mild nonproliferative diabetic retinopathy (NPDR) and severe NPDR/proliferative diabetic retinopathy (PDR) grading were calculated based on DFP and MSI and were compared with fundus fluorescein angiography. Results Compared with fundus fluorescein angiography, the exact agreement for MSI was 0.835; for DFP, it was 0.614; the sensitivity for no DR/mild NPDR in both MSI and DFP was 100%, and for severe NPDR/PDR, it was 97.4% and 88.3%. The specificity for no DR/mild NPDR in MSI and DFP was 96.3% and 95%, and for severe NPDR/PDR, it was 100% in both. The positive predictive value for no DR/mild NPDR in MSI and DFP was 86.4% and 82.6%, and for severe NPDR/PDR, it was 100% in both; the negative predictive value for no DR/mild NPDR in MSI and DFP was 100%, and for severe NPDR/PDR, it was 91.7% and 71.0% in both. Conclusion Multispectral imaging displayed an excellent agreement with fundus fluorescein angiography in DR grading, which suggested that it might serve as a new diagnostic technique and an informative tool for evaluating DR.

Organic–inorganic metal halide ferroelectric semiconductors are mainly lead halide ones, suffering from the presence of toxic lead. Herein, we report a lead-free bismuth iodide ferroelectric semiconductor [1,4-butanediammonium]BiI5, showing a high Curie temperature of 365 K and a small band gap of 1.95 eV, smaller than those of most lead halide counterparts.

Piezoelectric materials with inherent mechanical-electric coupling effect are a crucial family of functional materials in high-end information technology. For practical applications, the transverse piezoelectric performance (d31 or d32) is mainly considered, because this parameter is a vitally important index to characterize the performance of piezoelectric thin films. However, the transverse piezoelectricity of the thin films as a key figure of merit is seldom mentioned in molecular ferroelectrics. Herein, we report that a new 1D halide perovskite ferroelectric N,N-dimethylallylammoniumCdCl3 (DMAACdCl3) exhibits an above room-temperature ferroelectric phase transition with a saturated polarization of 1.9 μC cm-2 and a coercive field of 5.0 kV cm-1. The thin film of DMAACdCl3 is successfully fabricated using an easy processing spinning method and maintains well ferroelectric properties verified by piezoresponse force microscopy (PFM). More significantly, the ferroelectric thin film offers superior transverse piezoelectricity with an in-plane piezoelectric response of about 41 pC N-1, which is about twice that of well-known piezoelectric polymer PVDF (21 pC N-1). Transverse piezoelectricity has been scarcely studied in molecular ferroelectrics, and its exploitation would play an important role in the design of next-generation smart piezoelectric devices.

1,4-Diazabicyclo[2.2.2]octane (dabco) and its derivatives have been extensively utilized as building units of excellent molecular ferroelectrics for decades. However, the homochiral dabco-based ferroelectric remains a blank. Herein, by adding a methyl (Me) group accompanied by the introduction of homochirality to the [H

In this work, density functional theory (DFT) calculations are performed to understand the origin of the regioselective C-H borylation of aromatics catalyzed by Co(i)/

We developed a facile and low-cost approach to prepare lightweight and high-strength magnesium–matrix composites with a nacre-inspired laminated structure. First, lamellar Mg2B2O5 whisker (Mg2B2O5w) scaffolds with initial solid loadings of 10, 15 and 20 vol% were prepared by ice templating. The wettability between a molten AZ91D alloy and the Mg2B2O5w scaffold was greatly improved by the incorporation of nano-SiO2 sol in the aqueous slurry, making the preparation of nacre-mimetic AZ91D/Mg2B2O5w composite by way of pressureless infiltration feasible. The SiO2 content in the Mg2B2O5w scaffold has a significant effect on the processing and the microstructure and properties of the composites. The optimum SiO2 content was about 6–8 wt% of the total ceramic loading. A lower SiO2 content resulted in incomplete infiltration, while a higher content led to the formation of a large quantity of Mg2Si in the composite. The flexural strength of the composites seemed independent of the initial ceramic loading (10–20 vol%), whereas the compressive strength and elastic modulus increased considerably and the crack-growth fracture toughness decreased with increasing ceramic content. The mechanism for such variations was addressed.

This study explored the effects of ammonia oxidizing bacterial (AOB) strain S2_7_25 on the compensatory growth of corn (Zea mays L.) upon post-drought rewatering using seedlings as test materials. This study consisted of two treatment conditions: isolation and screening of AOB strain and AOB strain inoculated to soils. Isolated and screened from soil, S2_7_25 had 100% similarity to Acinetobacter pittii. The experimental design of S2_7_25 inoculation to soils was composed of five treatments: (1) wetness, (2) post-drought rewatering, (3) post-drought rewatering with S2_7_25 inoculation, (4) post-drought rewatering with nitrification inhibitor addition to soil and (5) post-drought rewatering with nitrification inhibitor addition to soil and S2_7_25 inoculation. Rewatering increased the total biomass and net photosynthetic rate of corn compared with wetness, and S2_7_25 inoculation greatly increased these parameters of rewatering corn. However, nitrification inhibitor addition greatly decreased these parameters of rewatering corn inoculated with or without S2_7_25. Rewatering increased the rhizosphere soil nitrification rate of corn, and rewatering with S2_7_25 inoculation further increased it. However, nitrification inhibitor addition decreased this parameter in rewatering corn with or without S2_7_25 inoculation. The cytokinin delivery rates from the roots to the leaves were regulated by soil nitrification in the rhizosphere, and it determined the leaf cytokinin concentration that is closely related to corn rewatering growth. The highest leaf cytokinin concentration during rewatering caused over-compensatory growth and the highest water use efficiency in rewatering corn with S2_7_25 inoculation among all treatments. Compensatory and under-compensatory growth occurred in rewatering corn and in corn with nitrification inhibitor addition, respectively. In a word, S2_7_25 increased corn compensatory growth by regulating soil nitrification and root-induced leaf cytokinin.

This study aimed to identify species of Fasciola flukes in Dali Prefecture (Yunnan Province, China) and analyze their genetic diversity. Fasciola flukes (n = 122) were collected from cattle livers in a farmers' market in Xiaguan Town, Dali Prefecture. Nucleotide sequences of ribosomal internal transcribed spacer (ITS) as well as nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1) and mitochondrial cytochrome c oxidase subunit 1 (CO1) were amplified, sequenced, and subjected to homology analysis. The heterozygosity ratios of different ITS alleles were determined using the peak-height ratio of heterozygous loci. Multiplex PCR analysis of the nuclear protein coding gene, phosphoenolpyruvate carboxykinase (pepck), was used to identify Fasciola species. Multiple ND1 sequence alignments enabled further genetic diversity analysis of regional Fasciola flukes. Seven ITS sequences belonged to F. hepatica and 115 belonged to Fh/Fg heterozygous flukes. Sequencing analysis of heterozygous flukes revealed 11 heterozygous loci with double peaks, with significantly variable ratios among individuals. ND1 and CO1 results indicated that one specimen was identical to F. hepatica, while 121 specimens were identical to F. gigantica or contained one variable site. Multiplex PCR results for pepck showed that double bands for F. hepatica and F. gigantica were amplified from Dali Fasciola specimens; hence, they were all heterozygous. By combining ITS, ND1, and CO1 sequences with multiplex pepck PCR results, all 122 specimens were identified as Fh/Fg heterozygous Fasciola flukes. Our experimental results preliminarily confirmed a high degree of Fh/Fg heterozygosity among Fasciola flukes in the Dali area. Selecting multiple molecular markers for concurrent analysis will provide more comprehensive and accurate genetic information.

This study aims to investigate the relationship between rhizosphere soil nitrification and compensatory growth of potted corn (Zea mays L.) seedlings upon post-drought rewatering on the basis of leaf cytokinin induced by roots. The nitrification inhibitor 3, 4-dimethylpyrazole phosphate was added to the soil to restrain nitrification in soil. The experimental design consisted of six treatments: (1) wetness, (2) wetness with the nitrification inhibitor addition, (3) wetness with the nitrification inhibitor and nitrate additions, (4) post-drought rewatering, (5) post-drought rewatering with the nitrification inhibitor addition, and (6) post-drought rewatering with the nitrification inhibitor and nitrate additions. The results showed that compared with wetness rewatering alone increased the aboveground and total biomasses and the net photosynthetic rates of corn, but rewatering had little influence on these parameters following the nitrification inhibitor addition or both the inhibitor and nitrate additions. Without the nitrification inhibitor addition, the increase of carbohydrate content in root exudates of rewatering corn caused by drought stress accounted for rhizosphere soil nitrification rate augment during rewatering that were closely related to the delivery rate of cytokinin from the roots to the leaves; however, increased nitrification rates in non-rhizosphere soil were not recorded in rewatering treatment. Without the addition of the nitrification inhibitor, the net leaf photosynthetic rate of corn increased due to the elevated cytokinin levels in leaves, leading to the occurrence of compensatory growth and high water use efficiency of corn. By contrast, nitrification inhibitor application decreased the rhizosphere soil nitrification rate, followed by the consequent under-compensatory growth and low water use efficiency of corn; and the under-compensatory growth and low water use efficiency of corn also occurred in corns with the addition of both nitrification inhibitor and nitrate. Therefore, rhizosphere nitrification plays a key role in corn compensatory growth.

Introduction Whether anesthesia depth affects postoperative mortality remains uncertain. Measurements Several databases were systematically searched to identify all articles studying the relationship between depth of anesthesia and postoperative mortality. Post hoc subgroup analyses were conducted for follow-up period (30 days vs. longer than 90 days) and type of surgery. Main results The analysis included 38,722 patients from nine studies. We observed a significant relationship between low bispectral index (BIS) and mortality (pooled aHR, 1.22;95% CI, 1.08 to 1.38; P = 0.001; I2 = 85.4%). Post hoc subgroup analyses indicated low BIS to be linked with significantly elevated mortality risk in patients with ≥90 days follow-up (pooled adjusted hazard ratio [aHR], 1.09; 95% CI, 1.00–1.19; P = 0.01; I2 = 79.4%), but this association did not achieve significance in those with a 30 day follow-up duration (pooled aHR, 1.52; 95% CI, 0.97–2.38; P = 0.28; I2 = 79.0%). In addition, this link between postoperative mortality and low BIS was significant in those who had undergone cardiac surgery (pooled aHR, 1.30; 95% CI, 1.14 to 1.49; P Conclusions We observed a significant relationship between deep anesthesia and long-term mortality, though this was not significant 30 days following surgery. In patients who had received cardiac surgery, deep anesthesia may increase mortality. However, this trend was not observed in patients who had undergone other forms of surgery.

The Fasciola hepatica miracidia were used to infect 10 Galba pervia in a random manner. Beginning from day 44 after infection on which 10 metacercariae were found and a total of 495 metacercariae found in 24 days. No signs of cercaria escape or metacercaria formation in the early morning observed during 8 : 00-24 : 00, regardless of the environmental change. Metacercaria formation occurred mainly in the early morning. The metacercariae could attach to any object in water, but were easy to detach themselves. The findings suggest that F. hepatica cercaria escape and metacercaria formation mainly occur in the early morning in Dali.

To investigate the effect and mechanism of miR-498 on Th17 cell differentiation of peripheral blood mononuclear cells (PMBCs) in rheumatoid arthritis (RA) patients, peripheral blood samples were collected from RA patients and healthy controls, respectively. The proportion of CD4

Using 3 wt% TiO2 nanopowders as sintering aid, we prepared porous lamellar Al2O3–ZrO2 composites with an initial solid loading of 30 vol% and the Al2O3/ZrO2 weight ratios of 1:9, 3:7, 5:5, 7:3, and 9:1 by freeze casting. The viscosity of water-based slurries decreased with increasing Al2O3 content while the porosity and the wavelength of the lamellae in the sintered scaffolds showed first an increase and then decrease with maximum values appearing at Al2O3:ZrO2 = 5:5. A relatively large amount of tetragonal (t) ZrO2 transformed to monoclinic (m) ZrO2 with the increase in the Al2O3 content and sintering temperature, thus reducing stress-induced phase transformation effect during loading. The compressive strength of the sintered scaffolds depended on sintering temperature, porosity, and the phase composition in the composites. A maximum value of 105 ± 10 MPa was achieved in the scaffolds with a composition of Al2O3:ZrO2 = 3:7 after sintering at 1450 °C for 2 h.

Gold-nanoparticle (Au-NP) non-volatile memories (NVMs) with low-damage CF4 plasma treatment on the blocking oxide (BO) layer have been investigated to present the gate injection of the holes. These holes, injected from the Al gate with the positive gate bias, were explained by the bandgap engineering of the gradually-fluorinated BO layer and the effective work function modulation of the Al gate. The Si–F complex in the BO layer was analyzed by X-ray photoelectron spectroscopy (XPS), while the depth of fluorine incorporation was verified using a secondary ion mass spectrometer (SIMS). In addition, the valence band modification of the fluorinated BO layer was examined by ultraviolet photoelectron spectroscopy (UPS) to support the bandgap engineering. The reactive power of the CF4 plasma treatment on the BO layer was modified to increase the electric field of the BO layer and raise the effective work function of the Al gate, leading to the hole-injection from the gate. The injected holes are trapped at the interface between the gold-nanoparticles (Au-NPs) and the tunneling oxide (TO) layer, resulting in superior data retention properties such as an extremely low charge loss of 5.7% at 104 s and a nearly negligible increase in charge loss at 85 °C of the CF4-plasma-treated Au-NP NVMs, which can be applied in highly reliable consumer electronics.

Human uveal melanoma (UM) is a major ocular malignant tumor with high risk of metastasis and requires multiple oncogenic factors for progression. ZEB1 is a zinc finger E-box binding transcription factor known for participating epithelial-mesenchymal transition (EMT), a critical cellular event for metastasis of malignant tumors of epithelium origin. ZEB1 is also expressed in UM and high expression of ZEB1 correlates with UM advancement, but has little effect on cell morphology. We show that spindle UM cells can become epithelioid but not vice versa; and ZEB1 exerts its tumorigenic effects by promoting cell dedifferentiation, proliferation, invasiveness, and dissemination. We provide evidence that ZEB1 binds not only to repress critical genes involving in pigment synthesis, mitosis, adherent junctions, but also to transactivate genes involving in matrix degradation and cellular locomotion to propel UM progression towards metastasis. We conclude that ZEB1 is a major oncogenic factor required for UM progression and could be a potential therapeutic target for treating UM in the clinic.

Medical institutions and health care billing system is mostly independent of the hospital information system software, such as the presence of a heavy workload and inconsistent information due to the Hospital Information System would like to produce a secondary entry problems. Design of Medicare billing software based on the interface, is the fundamental solution to the problem. This paper describes a specific Medicare interface specification, implementation of information exchange with the medical center by the dynamic link library functions, including the structure and format of the input and output parameters of the library function call, as well as medical insurance information processing flow. Select Delphi as a development tools, the definition of the interface specification stored in arrays, Achieve various Medicare functions of the Medicare interface specification with custom functions. A Medicare billing software system is completed with Medicare directory information management, Medicare card information management, Medicare fee settlement management, and the other Medicare functions.

Currently available monotherapies of oral nucleoside/nucleotide analogs or interferon are unable to achieve a sustained and effective response in most of patients with chronic hepatitis B (CHB). The objective of the present study was to compare the efficacy and safety of pegylated interferon (Peg-IFN) alpha-2b plus adefovir dipivoxil combination therapy versus Peg-IFN alpha-2b alone. Sixty-one HBeAg-positive chronic hepatitis B patients were randomized to receive Peg-IFN alpha-2b alone (1.5 μg/kg once weekly) or Peg-IFN alpha-2b plus adefovir (10 mg daily) for up to 52 weeks. Efficacy and safety analyses were performed on all participants who received at least one dose of study medication. The rate of HBeAg seroconversion and undetectable HBV-DNA were evaluated after 52 weeks of therapy. At the end of treatment, 11 of 30 (36.7%) patients receiving combination therapy achieved HBeAg seroconversion versus 8 of 31 (25.8%) in the monotherapy group (P=0.36). In contrast, the percentage of patients with undetectable serum HBV DNA was significantly higher in the combination group than in the monotherapy group (76.7% vs. 29.0%, P

Chondroitin sulfate, a type of acid mucopolysaccharide possessing a variety of bioactivities, has attracted tremendous interest due to its use in the relief of joint diseases. It has been widely applied in different fields, such as medicine, biotechnology, pharmacy, textiles, food and cosmetics. This mini-review focuses on the main methods of its extraction and purification, and recent advances in bio-syntheses and chemical synthesis of such molecules. In addition, further studies in these aspects are proposed based on current research. © 2014 Society of Chemical Industry

By analyzing the problem of k-means, we find the traditional k-means algorithm suffers from some shortcomings, such as requiring the user to give out the number of clusters k in advance, being sensitive to the initial cluster centers, being sensitive to the noise and isolated data, only being applied to the type found in globular clusters, and being easily trapped into a local solution et cetera. This improved algorithm uses the potential of data to find the center data and eliminate the noise data. It decomposes big or extended cluster into several small clusters, then merges adjacent small clusters into a big cluster using the information provided by the Safety Area. Experimental results demonstrate that the improved k-means algorithm can determine the number of clusters, distinguish irregular cluster to a certain extent, decrease the dependence on the initial cluster centers, eliminate the effects of the noise data and get a better clustering accuracy.