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The box girder is an important structure widely used in the ship and marine engineering, but the fracture problem is not extensively investigated. The paper adopts the stress intensity factor (SIF) as the fracture parameter to perform the threedimensional (3D) mixed mode fracture assessment of the box girder structure with crack damage. The bending load, torsion load and side load are first introduced to study box girder fracture behavior. And the related influencing factors including crack lengths, crack angles and combined loads are investigated emphatically. Besides, the crack growth angle is also investigated to evaluate the crack propagation behavior. The results show that the load types have a significant effect on the crack propagation. The effect of bending load is generally greater than torsion load. The combined effect of bending and torsion loads may be considered adopting a linear superposition principle under transverse crack and larger angle crack. Additionally, the SIFs produced by torsion load only have a slight change with the increased crack angles. When the side load is added, the area near the crack upper surface will be easy to occur unstable expansion. These findings from the present study will provide a guiding significance to evaluate the crack propagation of box girder under combined loads. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The incidence of thyroid cancer is rising globally. Most patients progress slowly, but some patients develop lymph node and distant metastasis earlier, and their prognosis is poor. Therefore, early diagnosis and warning of malignancy are very meaningful for such patients. SAS1B gene is a newly discovered protein expressed on the surface of mature egg cells and has metalloendopeptidase activity. We aimed at exploring whether SAS1B is involved in the occurrence of thyroid cancer, and at providing evidence for early diagnosis and targeted therapy of thyroid cancer. PATIENTS AND METHODS: In this study, a rabbit anti-human SAS1B polyclonal antibody was prepared by gene recombination technology. The indirect ELISA method was used to detect the SAS1B protein expression in the serum of 69 patients with thyroid cancer and 55 normal controls, and the relevant pathological factors were analyzed. Immunohistochemistry and PCR technology were used to investigate the expression levels of SAS1B protein and mRNA in 30 thyroid cancer tissues and 23 control thyroid tissues. RESULTS: The titer of SAS1B recombinant antibody was 1:51200. The expression of SAS1B in the serum of patients with thyroid cancer was higher than that in the normal control group (p<0.01). The antibody had a good sensitivity in serum detection of cancer patients (p=0.008<0.01), the linear regression analysis result was that the expression of SAS1B gene was related to tumor envelope invasion and lymph node metastasis (p=0.003<0.01, p=0.003<0.01), and it was irrelevant to the patient's gender, age, tumor mass size, number of cancer foci, pathological stage, etc. (p>0.05). The results of immunohistochemistry showed that SAS1B protein was mainly located in the cytoplasm and membrane of thyroid cancer cells. The expression intensity in thyroid cancer tissues was higher than that in control tissues (p<0.05), but it was not expressed in normal thyroid tissues. Antibodies showed a good sensitivity that was used to detect thyroid cancer tissues (p=0.000<0.01). The results of ordinary PCR detection using thyroid cancer tissue and control thyroid tissue showed that the amplification products of the three domains (N-terminal, C-terminal and catalytic domain) of the SAS1B gene showed high expression in thyroid cancer tissue. q-PCR results showed that the expression of SAS1B gene in thyroid cancer and control thyroid tissue was higher than that in control group (p<0.05), and the genes of Aurora A and BARD1 related to centrosome replication and DNA replication forks protection during the proliferation were highly expressed in thyroid cancer tissue. The study results suggested that SAS1B was involved in the carcinogenesis of thyroid cancer. The Hum_mPLoc.2.0 software, PSORT II software and UniProt software were used to predict that SAS1B protein had secretory protein properties. CONCLUSIONS: The above data indicate that the SAS1B gene is closely related to the process of thyroid cancer and can serve as a good tumor marker that can be used for early diagnosis and early warning of thyroid malignancy. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We conducted this study to analyze the EEG abnormalities of cognitive impairment and epileptic seizures in patients with epilepsy, as well as to investigate the application value of EEG in the diagnosis of epilepsy with cognitive impairment. PATIENTS AND METHODS: 62 cases of patients that were admitted to our hospital for the first diagnosis as status epilepticus were selected. Of those, 20 cases were accompanied by cognitive impairment. The America Biology Graphene type 24 leads channel video EEG was applied to monitor staging, index, frequency, and distribution range of epileptic discharge. The revised Wechsler Adult Intelligence Scale-Revised in China (WAIS-RC) and Wechsler Memory Scale-Revised in China (WMS-RC) were adopted to test cognitive function. RESULTS: The epileptic discharge index, discharge frequency and discharge distribution range of the conscious period, sleep I-II period and sleep III-IV period of epilepsy with the cognitive impairment group were evidently higher than those of epilepsy without cognitive impairment group. The differences were statistically significant (p<0.05). Intelligence Quotient (IQ) and Memory Quotient (MQ) level of the cognitive impairment group were the lowest in sleep III-IV period, with the next being the sleep I-II period; the highest was the conscious period, and the differences were statistically significant (p<0.05). With an increase of the epileptic discharge index, the discharge range, IQ and MQ level of cognitive impairment group decreased; differences were statistically significant (p<0.05). Therefore, the discharge index, frequency, and distribution range of epileptic discharge of epilepsy with cognitive impairment in different periods differed from epilepsy patients without cognitive impairment. According to the extent of cognitive impairment in different stages, discharge index, frequency, and distribution range were also different. CONCLUSIONS: The 24 h video EEG, which was used to monitor epileptic discharge characteristics, has a great application value for early identification of epilepsy with cognitive impairment. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To clarify whether microRNA-646 could regulate the proliferative potential and cell cycle progression of nasopharyngeal carcinoma cells through targeting mammalian target of rapamycin (mTOR). It, therefore, could influence the occurrence and progression of nasopharyngeal carcinoma. PATIENTS AND METHODS: Quantitative Real-time polymerase chain reaction (qRT-PCR) was used to detect expression of the levels of microRNA-646 and mTOR in tumor tissues and paracancerous tissues of patients with nasopharyngeal carcinoma. Besides, their expressions in nasopharyngeal carcinoma cell lines were determined by qRT-PCR. Survival analysis was conducted to evaluate the sensitivity and specificity of microRNA-646 in diagnosing nasopharyngeal carcinoma. The overall survival of patients with nasopharyngeal carcinoma was calculated based on their expression levels of microRNA-646. The regulatory effects of microRNA-646 and mTOR on proliferative potential and cell cycle progression were explored by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Dual-luciferase reporter gene assay was conducted to verify the relationship between microRNA-646 and mTOR, which was further confirmed by Pearson correlation analysis. Finally, gain-of-function experiments were carried out to determine whether microRNA-646 could regulate the proliferative potential and cell cycle progression of nasopharyngeal carcinoma cells by targeting mTOR. RESULTS: MicroRNA-646 was lowly expressed in nasopharyngeal carcinoma tissues and cell lines. Survival analysis confirmed the diagnostic value of microRNA-646 in nasopharyngeal carcinoma. Besides, the nasopharyngeal carcinoma patients with high level of microRNA-646 were expected to have a longer 5-year survival time compared with those with low level. Overexpression of microRNA-646 inhibited the proliferative potential and cell cycle progression of HONE1 and SUNE1 nasopharyngeal carcinoma cells. Dual-luciferase reporter gene assay detected the binding of microRNA-646 to mTOR. Moreover, mTOR was highly expressed in nasopharyngeal carcinoma tissues and cell lines. A negative correlation was found between microRNA-646 and mTOR. That is, the overexpression of mTOR could reverse the inhibitory effects of microRNA-646 on the proliferative potential and cell cycle progression of HONE1 and SUNE1 cells. CONCLUSIONS: MicroRNA-646 remains a low level in nasopharyngeal carcinoma. It inhibits the proliferative potential and cell cycle progression of nasopharyngeal carcinoma cells by targeting mTOR. It can, therefore, inhibit the development of nasopharyngeal carcinoma. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study aimed to investigate the effect of microRNA-605-3p (miR-605-3p) on cell proliferation, invasion and migration in prostate cancer cells, as well as its effects on the Enhancer Zeste Homolog 2 (EZH2) expression and the potential regulatory mechanisms. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was applied to detect the miR-605-3p expression in 52 pairs of Prostate Cancer (PCa) tissues and normal tissues, and to analyze the relationship between miR-605-3p expression and PCa pathological parameters. MiR-605-3p mimics were transfected into PCa cell line PC-3 and DU145 to achieve miR-605-3p overexpression. Then, Cell Counting Kit-8 (CCK-8), cell colony formation assay and transwell invasion and migration assay were performed to analyze miR-605-3p's effect on the biological function of prostate cancer cells. Finally, the potential mechanisms of downstream genes were explored through bioinformatics analysis and recovery experiments. RESULTS: We found that miR-605-3p expression in PCa was markedly lower than that in normal tissues. Patients with low miR-605-3p expression had higher tumor stage, higher incidence of lymph node metastasis and distant metastasis. In vitro analysis showed that miR-605-3p overexpression leads to a significant decrease in cell proliferation, invasion and migration ability. Subsequently, it was verified in cell line and tissue that EZH2 expression was remarkably increased in PCa, which was negatively correlated with miR-605-3p expression. In addition, the recovery experiment found that EZH2 can counteract the role of miR-605-3p in PCa, together they affected the malignant progression of PCa. CONCLUSIONS: MiR-605-3p was significantly associated with PCa stage, lymph node metastasis and distant metastasis and the poor prognosis; besides, it can inhibit the malignant progression of PCa. In addition, the study showed that miR-605-3p may inhibit the proliferation, invasion and migration ability of PCa by regulating EZH2. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Hepatocellular carcinoma (HCC) is a hypervascularized tumor. Aberrant angiogenesis is the main cause, which results in cancer growth and progression. It has been showed that microRNA-302 cluster (miR-302) may be associated with angiogenesis. Here, we aimed to identify the role of miR-302a/b/c in the regulation of cell angiogenesis in HCC. PATIENTS AND METHODS: MRNA expression of miR-302a/b/c and MACC1 was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The protein of MACC1 was measured using Western blot. Cells proliferation, migration, and invasion abilities were investigated via Cell Counting Kit-8 (CCK-8) assay or transwell assay, respectively. Tube formatting assays were used to explore the tube formation capacity. The interaction among miR-302a/b/c was analyzed by luciferase assay. RESULTS: The expression of miR-302a/b/c was greatly reduced while MACC1 expression, whether mRNA or protein was conspicuously elevated in HCC tissues and cells. Then, functional experiment results showed miR-302a/b/c overexpression and MACC1 down-regulation inhibited the proliferation, migration, invasion ability, and tube formation capacity of HUVECs. In addition, we detected that miR-302a/b/c directly targeted MACC1 and suppressed MACC1 expression, and miR-302a/b/c could suppress tumor angiogenesis in HCC by targeting MACC1. CONCLUSIONS: MiR-302a/b/c may function as a potential suppressor of tumor angiogenesis in HCC by targeting MACC1, indicating a promising target for HCC therapy. [ABSTRACT FROM AUTHOR]

Chlorophyll a concentration [ρ(Chla)] in phytoplankton is used to understand algal biomass and the primary productivity of a water body. To investigate the seasonal dynamics of [ρ(Chla)] and their relationship with environmental factors Tiegang Reservoir at Guangdong China, continuous observation and analysis was carried out from April 2013 to June 2014. The distribution of algae had an obvious spatial heterogeneity, and the ρ(Chla) gradual increased from the southeast to the northwest of the reservoir. From April to early December 2013 and from late April to June 2014, the dominant algae was cyanobacteria. In other months, bacillariophyta were dominant. Chlorophyta were at a low level throughout the year. Multivariate analysis showed that water temperature (WT) was the primary driving factor of the spatio-temporal distribution of algae. The main environmental factors of cyanobacteria, bacillariophyta and chlorophyta were greatly different. Single environmental factors such as WT, total organic carbon (TOC), nitrate nitrogen (NO3--N), and chemical oxygen demand (COD) were significantly related to the competitiveness of cyanobacteria and bacillariophyta. And they can be used as early warning indexs for cyanobacteria and diatom blooms. The dual synergistic effects of WT and other environmental factors on the competitiveness of cyanobacteria and bacillariophyta were analyzed. A combination of environmental factors at high risk for cyanobacteria or diatoms were found. [ABSTRACT FROM AUTHOR]

Aims. There are two goals in this study. One is to investigate how frequently white-light flares (WLFs) occur in a flare-productive active region (NOAA active region 11515). The other is to investigate the relationship between WLFs and magnetic transients (MTs). Methods. We used the high-cadence (45 s) full-disk continuum filtergrams and line-of-sight magnetograms taken by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) to identify WLFs and MTs, respectively. Images taken by the Atmospheric Imaging Assembly (AIA) on board SDO were also used to show the flare morphology in the upper atmosphere. Results. We found at least 20 WLFs out of a total of 70 flares above C class (28.6%) in NOAA active region 11515 during its passage across the solar disk (E45°-W45°). Each of these WLFs occurred in a small region, with a short duration of about 5 min. The enhancement of the white-light continuum intensity is usually small, with an average enhancement of 8.1%. The 20 WLFs we observed were found along an unusual configuration of the magnetic field that was characterized by a narrow ribbon of negative field. Furthermore, the WLFs were found to be accompanied by MTs, with radical changes in magnetic field strength (or even a sign reversal) observed during the flare. In contrast, there is no obvious signature of MTs in the 50 flares without white-light enhancements. Conclusions. Our results suggest that WLFs occur much more frequently than previously thought, with most WLFs being fairly weak enhancements. This may explain why WLFs are reported rarely. Our observations also suggest that MTs and WLFs are closely related and appear cospatial and cotemporal, when considering HMI data. A greater enhancement of WL emission is often accompanied by a greater change in the line-of-sight component of the unsigned magnetic field. Considering the close relationship between MTs and WLFs, many previously reported flares with MTs may be WLFs. [ABSTRACT FROM AUTHOR]

3-Aminophenylboronic acid (APBA) and the complex Ru(bpy)2(phendione)2+ (bpy = 2,2′-bipyridine, phendione = 1,10-phenanthroline-5,6-dione) were found to be useful building blocks for preparing photomagnetic carbon surfaces. Scanning tunneling microscopy (STM) showed that when APBA was diazotized in acidic sodium nitrite solutions and cathodically reduced with highly ordered pyrolytic graphite (HOPG) electrodes, nanoscale films formed on the electrodes. The resulting HOPG had strong affinities for phendione and Ru(bpy)2(phendione)2+ as the electrodes were biased in the presence of them, respectively, with voltages more negative than the cathodic peak potentials for phendione/phendiol and Ru(bpy)2(phendione)2+/Ru(bpy)2(phendiol)2+ (phendiol = 1,10-phenanthroline-5,6-diol). However, if APBA was excluded, the affinities did not exist. Boronate ester formation featured prominently in these intermolecular interactions. The average increments in the HOPG surface roughness contributed by APBA and Ru(bpy)2(phendione)2+ were roughly 1 : 2, suggesting that the reaction stoichiometry between APBA and Ru(bpy)2(phendione)2+ be 1 : 1. Ru(bpy)2(phendione)2+ could also be grafted to carbon nanotubes (CNTs) under conditions similar to those for the HOPG using ascorbate as sacrificial donor. The resulting CNTs and HOPG exhibited photomagnetism when exposed to the 473 nm light. The ruthenium complex was shown to be a room-temperature photomagnetism precursor, and APBA was shown to be an effective molecular bridge for the complex and carbon substrates. [ABSTRACT FROM AUTHOR]

A cross-sectional cohort study was conducted to investigate whether ghrelin level in obese women predicts the quality of life (QOL). A total of 307 subjects fulfilled the criteria: (1) age between 20 and 65 years old, (2) body mass index ≥27 kg/m2(3) waist circumference ≥80 cm were enrolled in the study. All subjects were assigned to one of the plasma ghrelin level categories according to the quartiles. The median of age and BMI of the 307 obese women were 45 ± 18 years and 29.9 ± 4.1 kg/m2, respectively. The main outcome evaluated is the associations of plasma ghrelin level and QOL, which were evaluated using multiple linear regression analysis. Results of linear trend test show significant statistical difference in plasma lipoproteins (triglyceride, cholesterol, HDL-cholestero and LDL-cholesterol = and levels of obesity-related hormone peptides, including leptin, adiponectin, insulin among quartiles of ghrelin. Multiple liner regression analysis of serum obesity-related hormone peptide level and QOL using stepwise method shows ghrelin concentration was the only predictor of QOL, including PCS-12 level (β = −0.18,p = 0.001), MCS-12 level (β = −0.14,p = 0.009), WHOQOL-BREF scores: physical (β = −0.13,p = 0.03), psychological (β = −0.16,p = 0.007), social (β = −0.21,p =  < 0.001), and environmental (β = −0.22,p =  <0.001), after adjusting other factors for obese female subjects. This study demonstrated that ghrelin concentration is strongly associated with QOL level among obese women. Hence, ghrelin concentration might be a valuable marker to be monitored in obese women. [ABSTRACT FROM PUBLISHER]

OBJECTIVE: This study was aimed to explore the role of long noncoding RNA (lncRNA) AB073614 and its potential mechanisms in the glioma development. MATERIALS AND METHODS: Expression levels of lncRNA AB073614 in glioma tissues and glioma cell lines were evaluated by quantitative real-time PCR (qRT-PCR). MTT assays were conducted to explore the impact of AB073614 down-regulation on the proliferation of human glioma cells. The effects of AB073614 knockdown on cell proliferation and migration were evaluated by in vitro assays. EMT-related molecular markers expression level was detected by qRT-PCR assay and Western blot analysis. RESULTS: We confirmed that AB073614 was significantly upregulated in glioma tissues and cell lines (p < 0.01). In vitro studies demonstrated that knockdown of AB073614 inhibits U251 cell proliferation and migration. Moreover, knockdown of AB073614 could inhibit epithelial- mesenchymal transition (EMT) phenotype in glioma cells. CONCLUSIONS: AB073614 functions as a tumor promoter in glioma. This finding may provide a therapeutic approach for future treatment of glioma. [ABSTRACT FROM AUTHOR]

Lymphangioleiomyomatosis (LAM) is a rare multisystem disease occurring almost exclusively in premenopausal women and characterized by cystic lung destruction, abdominal tumors (renal angiomyolipomas (AML)), and involvement of the axial lymphatics (adenopathy, lymphangioleiomyomas). Serum vascular endothelial growth factor-D (VEGF-D), a lymphangiogenic factor, has been recently considered as a novel marker for LAM. Herein we report the diagnostic and differential diagnostic value of serum VEGF-D in LAM patients and evaluate the change of serum VEGF-D levels before and after treatment with sirolimus. The study group included 66 patients with LAM (47 definite LAM and 19 probable LAM based on European Respiratory Society guidelines), 14 patients with other polycystic lung diseases, and 20 healthy female controls. Serum VEGF-D levels were quantified by enzymelinked immunoassay (ELISA). Serum VEGFD levels were significantly increased in definite LAM patients compared with healthy controls (3890.3±373.3 pg/ml vs. 413.3±33.2 pg/ml, p<0.05). The optimal cutoff point for LAM diagnosis was 692.5 pg/ml with sensitivity of 97.9% and specificity of 100%. In probable LAM patients, serum VEGF-D levels were all greater than 692.5 pg/ml. Serum VEGF-D levels were significantly increased in definite LAM patients who had chylothorax compared with those without chylothorax (5153.9±598.3 pg/ml vs. 2869.8±372.8 pg/ml, p<0.05). But serum VEGF-D levels in LAM patients with/ without pneumothorax, AML, and lymphangioleiomyomas were not significantly changed. Serum VEGF-D levels in definite LAM patients and patients with other cystic lung diseases were 3890.3±373.3 pg/ml and 412.6±27.5 pg/ml, respectively (p<0.05). We determined an optimal cutoff value of 688.5pg/ml, resulting in sensitivity of 97.9% and specificity of 100%. Following a median of 12-month treatment with sirolimus, serum VEGF-D levels decreased from 3135.0±909.4 pg/ml to 1731.8±621.2 pg/ml and symptoms improved. Our study found that serum VEGF-D levels were significantly higher in LAM patients compared with healthy controls and patients with other polycystic lung diseases and that the levels were further increased when complicated by chylothorax. Serum VEGF-D levels may be useful for diagnosis and differential diagnosis with high specificity and sensitivity as well as for following treatment response with sirolimus. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We tested whether injection of contrast medium via right or left arm would affect venous artifacts on head and neck multislice spiral computed tomography (CT) angiography. PATIENTS AND METHODS: 326 patients were enrolled. Each patient was injected with 10 ml of contrast medium at 5 ml/sec. Time of peak contrast value plus an additional 1 sec was defined as delay time. Another 40 ml of contrast medium were injected with the same injection speed. The scanning area ranged from the aortic arch to the top of the head. Left and right forearms were used for intravenous injections of contrast medium in, respectively, 151 and 175 patients. Comparative analyses of image quality included determining contrast medium residues remaining in the superior vena cava, brachiocephalic vein, or subclavian vein, and comparisons of quality of three-dimensional CT angiography. RESULTS: In 75% of head and neck angiographies, the delay time of the common carotid artery ranged from 16 to 22 sec. In 60% of the images, the quality was graded as excellent, with the left arm injection resulting in delay time of > 23 sec and the right arm delay time of > 18 sec. The CT imaging quality after contrast injections via left or right arms was statistically significant (p < 0.05). The image quality after right arm injection was better than after left arm injection. CONCLUSIONS: Intravenous injection of contrast medium via right arm reduces artifacts from contrast medium residues and improves the image quality of head and neck CT angiography. [ABSTRACT FROM AUTHOR]

To improve the corrosion resistance and mechanical properties of AM50 magnesium alloy, T6 heat treatment was applied. The microstructure, mechanical properties and corrosion properties of as-cast and T6 heat-treated alloy were studied. The results indicated that the β phase presented at the grain boundaries along with Al-Mn phase after T6 heat-treatment. Because of solid solution and aging treatments, the tensile strength of the AM50 magnesium alloy was increased. The decreasing of the β phase owing to the solidsolution during T6 treatment, which causes Al solid solution in the α-Mg phase, and it is favourable for increasing the corrosion resistance of AM50 magnesium alloy. The fracture mechanisms of the as-cast and T6 heat-treated alloy were quasi-cleavage fracture. The corrosion residual strength of the T6 heat-treated alloy was higher than that of the as-cast alloy. Compared with the as-cast alloy, the corrosion rate of the T6 heat-treated alloy decreased gradually. [ABSTRACT FROM AUTHOR]

Influence of the system temperature on the micro-structures and dynamics of dust clusters in dusty plasmas is investigated through laboratory experiment and molecular dynamics simulation. The micro-structures, defect numbers, and pair correlation function of the dust clusters are studied for different system temperatures. The dust grains' trajectories, the mean square displacement, and the corresponding self-diffusion coefficient of the clusters are calculated for different temperatures for illustrating the phase properties of the dust clusters. The simulation results confirm that with the increase in system temperature, the micro-structures and dynamics of dust clusters are gradually changed, which qualitatively agree with experimental results. [ABSTRACT FROM AUTHOR]

Effects of the system temperature on dust aggregation in plasmas are investigated using two-dimensional molecular dynamics simulations. It is shown that as the system temperature increases, the boundary of the clusters becomes gradually irregular (i.e., deviating from sphere-like), and the cluster system gradually changes from solid to liquid and finally to gas state. The mean square displacement, mean nearest-neighbor distance in the clusters, cluster size and coupling parameter of the system are obtained and the properties of the system structure and dynamics are investigated. The time τ needed for reaching equilibrium for different temperatures is obtained. It is shown that τ firstly decreases and then increases with the temperature, indicating that there is an optimum temperature allowing a dust aggregation to reach an equilibrium state most rapidly. The simulation results agree qualitatively with the experimental observations. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

A facile fabrication of flower-shaped porphyrin Janus colloids with oriented arrangement was demonstrated based on the interfacial assembly and water droplet template. The as-fabricated colloidal crystals from flower-shaped Janus particles show a special optical signal produced from the hierarchical structures. [ABSTRACT FROM AUTHOR]

The plasmonic properties of asymmetric /2/ sandwiched cross-shape nanobars are investigated theoretically using the discrete dipole approximation (DDA) method. Two localized surface plasmon resonances are observed in the extinction spectra, which perform extreme sensitivity to the length and width of the nanobar and can be tuned easily throughout visible and into near-infrared spectral regions. The local electric fields around the nanobar are calculated and a pure electromagnetic Raman enhancement factor of about 106 can be achieved. In addition, compared to a monolayer gold nanobar, it exhibits more "hot spots" and stronger localized electric field enhancements. This plasmonic substrate provides potential applications in surface enhanced Raman scattering (SERS) and nonlinear optical devices. [ABSTRACT FROM AUTHOR]