Rapid and ultra-sensitive trace metals detection of water by partial Leidenfrost superhydrophobic array surface enhanced laser-induced breakdown spectroscopy.

The rapid and ultra-sensitive detection of trace elements in liquid is a primary concern for researchers. In this study, a partial Leidenfrost effect superhydrophobic (PLSHB) array surface was used for rapid in situ evaporation enrichment of sample droplets. Within 4 min, a 50 µL droplet sample was completely evaporated, resulting in all solutes in it being concentrated within a circular range measuring approximately 350 µm in diameter, without the formation of a coffee ring structure. The limits of detection for six metals (Pb, Ba, Be, Mn, Cr, Cu) in water were determined to be as follows: 0.82 µgL-1, 0.27 µgL-1, 0.033 µgL-1, 0.136 µgL-1, 0.241 µgL-1, and 0.083 µgL-1. Furthermore, laser-induced breakdown spectroscopy (LIBS) was employed to detect the enriched solutes from ten liquid samples with identical concentrations on the PLSHB array surface; these measurements exhibited a relative standard deviation (RSD) of only 3.7%. Spike experiments involving the addition of the aforementioned six metals into drinking water demonstrated recovery rates ranging from 85.7% to 117.7%. Therefore, the application potential of PLSHB array surface enhanced LIBS for rapid, stable, and ultra-sensitive detection and analysis of trace metal elements across various fields such as industry, environmental science, and biomedicine might be highly promising.

Synthetic spectra generated by boundary equilibrium generative adversarial networks and their applications with consensus algorithms.

One of the major restrictions in spectroscopic analysis is the limited number of calibrations, especially for biological samples. Meanwhile, there is a lack of effective algorithms to simulate synthetic spectra from the real spectra of limited samples. Thus in this work, a boundary equilibrium generative adversarial network (BEGAN) was proposed to automatically generate synthetic spectra and successfully produce spectra from two datasets. Then, the impact of the diversity ratio was estimated in the aspect of the quality and diversity of the generated spectra by BEGAN, and a negative correlation was found between quality and diversity. Finally, these synthetic spectra are applied in a consensus algorithm named creating diversity partial least squares (CDPLS) to replenish virtual samples in every iteration. Results show that the synthetic spectra generated by BEGAN are of high quality and improve the predictive performance of CDPLS. It can concluded that BEGAN has the potential to generate derived homologous spectra and expand the number of spectra in some small sample sets.

Picosecond Laser-Textured Stainless Steel Superhydrophobic Surface with an Antibacterial Adhesion Property.

The pursuit of antibacterial properties on the surfaces of food container, medical equipment, and pharmaceutical tanks has been a compelling challenge for decades. Inspired by the biomimetic superhydrophobic surfaces that have self-cleaning, antifog, antisnow, and reduced bacterial adhesion properties, we use a simple and effective technology of a picosecond laser texturing for the fabrication of a superhydrophobic antibacterial surface on AISI 420 martensitic stainless steel plates. The laser-textured surface with micropapillae patterns with superimposed nanostructures exhibits outstanding in-air superhydrophobic and superaerophilicity underwater, which under the oscillation state resists an adhesion of 99% Escherichia coli and 93% Staphylococcus aureus and has hardly any bacterial adhesion under a stationary state. The comparative experiments verify that the robust air layer and hierarchical micro-nanostructures have come together to comprise the antibacterial mechanism. The laser-textured superhydrophobic surface also exhibits superior anticorrosion and antidestructive abilities with excellent antibacterial durability especially if deep cleaning is carried out after each dipping time in the bacterial suspension, promoting its leading-edge applications in medical, food, and pharmaceutical fields.

C6orf106 accelerates pancreatic cancer cell invasion and proliferation via activating ERK signaling pathway.

C6orf106 was highly expressed in lung and breast cancer, and proposed as clinicopathologic factor for the development of those types of cancer. However, its expression in pancreatic cancer and the mechanism that C6orf106 functions as an oncogene has not been confirmed. In the present study, we found that C6orf106 was also up-regulated in pancreatic cancer tissues and cell lines. Furthermore, C6orf106 expression was associated with advanced T stage (P = 0.010), positive regional lymph node metastasis (P = 0.012), and advanced TNM stage (P = 0.006). In vitro experiments also showed that C6orf106 served a tumor enhancer in pancreatic cancer, through increasing the expression of Snail, Cyclin D1 and Cyclin E1, and reducing the expression of E-cadherin via activating extracellular-signal-regulated kinase (ERK)- p90-kDa ribosomal S6 kinases (P90RSK) signaling pathway. The addition of ERK inhibitor PD98059 counteracted the upregulation of Snail, Cyclin D1 and Cyclin E1, and restored the expression of E-cadherin, which indicated that C6orf106 was an upstream factor of ERK signaling pathway. Taken together, the present study indicates that C6orf106 facilitates invasion and proliferation of pancreatic cancer cells, likely via activating ERK-P90RSK signaling pathway.

ZC3H13 suppresses colorectal cancer proliferation and invasion via inactivating Ras-ERK signaling.

ZC3H13 is a canonical CCCH zinc finger protein, which harbors a somatic frame-shift mutation in colorectal cancer (CRC). However, its expression and biological function were still uncertain. In the current study, we found that ZC3H13 was served as a tumor suppressor in CRC cells, which decreased the expression of Snail, Cyclin D1, and Cyclin E1, and increased the expression of Occludin and Zo-1 through inactivating Ras-ERK signaling pathway. Furthermore, reduction of ZC3H13 associated with advanced TNM stage (p = 0.02), positive regional lymph node metastasis ( p = 0.01). Taken together, the current study indicated that ZC3H13 may be an upstream regulator of Ras-ERK signaling pathway and suppressed invasion and proliferation of CRC.

TMEM206 promotes the malignancy of colorectal cancer cells by interacting with AKT and extracellular signal-regulated kinase signaling pathways.

BACKGROUND: The roles of TMEM206, a new transmembrane protein, in cancer, including colorectal cancer (CRC), are unknown. Related family members, including TMEM16A, TMEM132A, and TMEM176B, have been shown to be involved in various biological behaviors. In addition, TMEM88 has been reported to promote non-small-cell lung cancer. In this study, we examined the roles of TMEM206 in CRC. METHOD: Real-time reverse transcription polymerase chain reaction was used to measure TMEM206 messenger RNA (mRNA) levels in clinical specimens and transfected cell lines. Immunohistochemistry was used to determine the relationship between TMEM206 expression levels and clinical data. Plasmids and small interfering RNA were used to upregulate and silence TMEM206, respectively. Protein expression levels and signaling pathway modulation were validated through western blot analysis. Colony formation, MTT, cell migration and invasion assays, and flow cytometry analyses were used to test the potential roles of TMEM206 in CRC. Co-immunoprecipitation was used to evaluate the interaction between TMEM206 and AKT. RESULTS: Investigation of the clinical significance of TMEM206 expression in CRC tissues revealed that TMEM206 mRNA and protein levels were higher in CRC tissues than in paired normal adjacent tissues (p < 0.05). TMEM206 overexpression was positively associated with T stage of cancer and UICC stage ( p < 0.05) and negatively related to differentiation of CRC ( p = 0.015). Upregulation or silencing of TMEM206 promoted or inhibited the proliferation of CRC cells and positively or negatively regulated the levels of phospho-AKT and downstream signaling pathway components (phospho-glycogen synthase kinase 3ß and cyclin D1), respectively. Moreover, silencing of TMEM206 in cell lines arrested CRC cells in the G1 stage of the cell-cycle. In addition, upregulating or silencing TMEM206 increased or decreased cell invasion and migration in vitro and positively or negatively altered levels of the phospho-extracellular signal-regulated kinase (ERK) and phospho-focal adhesion kinase 397, respectively. Co-immunoprecipitation demonstrated that AKT and TMEM206 proteins interacted. Furthermore, TMEM206 promoted the development and progression of CRC by enhancing the interactions between the AKT and ERK signaling pathways. CONCLUSION: TMEM206 controlled the progression of CRC by accelerating CRC cell proliferation and promoting CRC cell migration and invasion. The target of TMEM206 may be AKT, which is known to be involved in modulating the biological behaviors of various cancers.

Picosecond Laser-Induced Hierarchical Periodic Near- and Deep-Subwavelength Ripples on Stainless-Steel Surfaces.

Ultrafast laser-induced periodic surface subwavelength ripples, categorized based on the ripple period into near-subwavelength ripples (NSRs) and deep-subwavelength ripples (DSRs), are increasingly found in the variety of materials such as metals, semiconductors and dielectrics. The fabrication of hierarchical periodic NSRs and DSRs on the same laser-irradiated area is still a challenge since the connection between the two remains a puzzle. Here we present an experimental study of linearly polarized picosecond laser-induced hierarchical periodic NSRs and DSRs on stainless-steel surfaces. While experiencing peak power density higher than a threshold value of 91.9 GW/cm2, in the laser-scanned area appear the hierarchical periodic NSRs and DSRs (in particular, the DSRs are vertically located in the valley of parallel NSRs). A large area of the uniformly hierarchical periodic NSRs and DSRs, with the spatial periods 356 ± 17 nm and 58 ± 15 nm, respectively, is fabricated by a set of optimized laser-scanning parameters. A qualitative explanation based on the surface plasmon polariton (SPP) modulated periodic coulomb explosion is proposed for unified interpretation of the formation mechanism of hierarchical periodic NSRs and DSRs, which includes lattice orientation of grains as a factor at low peak power density, so that the initial DSRs formed have a clear conformance with the metallic grains.

Synaptotagmin7 Is Overexpressed In Colorectal Cancer And Regulates Colorectal Cancer Cell Proliferation.

Purpose: Synaptotagmin7 (SYT7) belongs to the synaptotagmin gene family and plays an important role in synaptic transmission. However, the function of this gene in most human cancer especially in colorectal cancer (CRC) remains unknown. In this research, we examined SYT7's role in CRC and tried to reveal its underlying mechanism. Methods: We examined SYT7's expression levels in normal colorectal tissue and CRC tissues from 83 patients and analyzed the possible correlation between the expression level of SYT7 and pathological characteristics. The influences of SYT7 knockdown on cell growth were detected by Celigo image cytometer, colony formation assay, cell cycle analysis and apoptosis assay in vitro. The possible molecular mechanism was assessed using a microarray and Ingenuity Pathway Analysis. Results: Our results show that the expression of SYT7 is upregulated in colorectal cancer tissues in comparison with normal tissues and positively correlated with the pathological stage of colorectal cancer. (P=0.015). We examined SYT7's role in human colorectal cancer cell line RKO by using SYT7-shRNA and revealed that SYT7 knockdown inhibit cell proliferation (P=8.6E-5), clonogenic ability (P=4.5E-6) and promoted G2/M Phase arrest and apoptosis (P=4.6E-7). Multiple cancer-associated pathways regulated by SYT7 were unraveled by microarray and Ingenuity Pathway Analysis. Conclusions: Our study suggests that SYT7 plays an important role in the development of CRC and SYT7 may become a new therapeutic target in CRC.

miR­1 inhibits the progression of colon cancer by regulating the expression of vascular endothelial growth factor.

MicroRNA (miR)­1 is associated with various human malignancies through repressing tumor growth, migration and angiogenesis. Recently, high­throughput transcriptional profiling confirmed that miR­1 is markedly downregulated in metastatic colorectal cancer; however, its biological functions and the specific underlying mechanisms in colorectal cancer (CRC) require further investigation. In this study, the expression of miR­1 in 111 CRC and paired normal tissue samples was measured using quantitative polymerase chain reaction analysis, and the association between miR­1 expression and clinical characteristics was evaluated. miR­1 was found to be significantly downregulated in CRC tissues compared with paired normal tissues, and in CRC cell lines compared with non­cancer cells (P<0.001), and was negatively associated with tumor size (P=0.001), differentiation (P=0.011), lymph node metastasis (P=0.001) and TNM stage (P=0.001). Further experiments revealed that miR­1 inhibited the migration and invasion of HCT116 and ClonA1 cells, and inhibited cell proliferation by affecting the cell cycle. Vascular endothelial growth factor (VEGF) was found to be a potential target of miR­1 by biological prediction, and further investigation confirmed that miR­1 significantly inhibited the expression and paracrine function of VEGF. In CRC tissues, the expression of VEGF was negatively correlated with miR­1. The low expression of miR­1 in CRC may be one of the reasons for the abnormally high expression of VEGF; the upregulation of miR­1 expression may inhibit cancer progression by downregulating VEGF. These findings indicate that treatment with miR­1 may be a novel method of tumor suppression, and provide a theoretical and experimental basis for the further targeted treatment of CRC through the regulation of miR­1 and VEGF expression.

Laser-Induced Breakdown Spectroscopy for Rapid Discrimination of Heavy-Metal-Contaminated Seafood Tegillarca granosa.

Tegillarca granosa samples contaminated artificially by three kinds of toxic heavy metals including zinc (Zn), cadmium (Cd), and lead (Pb) were attempted to be distinguished using laser-induced breakdown spectroscopy (LIBS) technology and pattern recognition methods in this study. The measured spectra were firstly processed by a wavelet transform algorithm (WTA), then the generated characteristic information was subsequently expressed by an information gain algorithm (IGA). As a result, 30 variables obtained were used as input variables for three classifiers: partial least square discriminant analysis (PLS-DA), support vector machine (SVM), and random forest (RF), among which the RF model exhibited the best performance, with 93.3% discrimination accuracy among those classifiers. Besides, the extracted characteristic information was used to reconstruct the original spectra by inverse WTA, and the corresponding attribution of the reconstructed spectra was then discussed. This work indicates that the healthy shellfish samples of Tegillarca granosa could be distinguished from the toxic heavy-metal-contaminated ones by pattern recognition analysis combined with LIBS technology, which only requires minimal pretreatments.

A novel spectral multivariate calibration approach based on a multiple fitting method.

This paper introduces a novel multivariate regression approach based on a multiple fitting algorithm that combines fitting functions to accordingly configure different regression models for the quantitative analysis of spectra data. The novel regression method employs multivariate fitting functions to characterize the potential functional relationship of spectral information and sample information with the corresponding attributes, and uses single fitting function elements as the independent variables for biased parameters to determine the amplitude of each fitting function. The peak width of the different fitting functions and the biased parameters are optimized by a simulated annealing algorithm. After parameter optimization, the fitting functions are superposed together to form a functional super surface, and a multiple fitting regression model is then used to characterize any functional relationship among the spectral variable information, sample information, and the corresponding analyte information. In this paper, a common fitting function, namely the Gaussian function, is used to create multiple fitting regression models. The simulated dataset and two real near infrared spectral datasets were used to validate the multiple fitting regression model. The results are compared to those obtained using partial least squares regression and least squares support vector regression. It is shown that the proposed multiple fitting regression algorithm achieved an accuracy comparable to the two conventional methods. Therefore, the multiple fitting regression is demonstrated to be a useful tool for spectra multivariate regression analysis and may also be suitable for linear and nonlinear multivariate calibration.

Efficient white light emitting diodes based on Cu-doped ZnInS/ZnS core/shell quantum dots.

We report the fabrication of efficient white light-emitting diodes (WLEDs) based on Cu : ZnInS/ZnS core/shell quantum dots (QDs) with super large Stokes shifts. The composition-controllable Cu : ZnInS/ZnS QDs with a tunable emission from deep red to green were prepared by a one-pot noninjection synthetic approach. The high performance Cu : ZnInS QD-WLEDs with the colour rendering index up to 96, luminous efficacy of 70-78 lm W(-1), and colour temperature of 3800-5760 K were successfully fabricated by integration of red and green Cu-doped QDs. Negligible energy transfer between Cu-doped QDs was clearly found by measuring the photoluminescence lifetimes of the QDs, consistent with the small spectral overlap between QD emission and absorption. The experimental results indicated low toxic Cu : ZnInS/ZnS QDs could be suitable for solid state lighting.

Exploring the effect of band alignment and surface states on photoinduced electron transfer from CuInS2/CdS core/shell quantum dots to TiO2 electrodes.

Photoinduced electron transfer (ET) processes from CuInS2/CdS core/shell quantum dots (QDs) with different core sizes and shell thicknesses to TiO2 electrodes were investigated by time-resolved photoluminescence (PL) spectroscopy. The ET rates and efficiencies from CuInS2/CdS QDs to TiO2 were superior to those of CuInS2/ZnS QDs. An enhanced ET efficiency was surprisingly observed for 2.0 nm CuInS2 core QDs after growth of the CdS shell. On the basis of the experimental and theoretical analysis, the improved performances of CuInS2/CdS QDs were attributed to the passivation of nonradiative traps by overcoating shell and enhanced delocalization of electron wave function from core to CdS shell due to lower conduction band offset. These results indicated that the electron distribution regulated by the band alignment between core and shell of QDs and the passivation of surface defect states could improve ET performance between donor and acceptor.

Determination of Ca and Mg in aqueous solution by laser-induced breakdown spectroscopy using absorbent paper substrates.

Laser-induced breakdown spectroscopy has been performed to detect trace metal elements (Ca and Mg) in aqueous solution. In order to overcome the sensitivity drawbacks in liquid sample analysis, an absorbent paper was used as the sample support in this experiment. Calibration curves were constructed by using the standard solution with variable concentration and the limit of detection was estimated for each element. Finally this system was used to analyze three types of water samples collected from different locations in Nanjing, China and the results were compared with inductively coupled plasma atomic emission spectroscopy and showed good correlation.

[Effects of experimental parameters on elemental analysis of aluminum alloy by laser-induced breakdown spectroscopy].

Laser-induced breakdown spectroscopy (LIBS) has been used to detect the elements of 2519A aluminum alloy by Nd : YAG laser in the present paper. The atomic spectral lines of Al and Cu were observed using a portable spectrometer. The impacts of lens-to-sample distance, probe angle, laser pulse energy, observation height and ambient pressure on the line intensities were studied. The results show that all these experimental parameters have great influence on the precision of LIBS such as line intensity, signal to background ratio and repeatability. Finally, the best results can be observed by using the optimum experimental conditions.