Failure Analysis of Abnormal Cracking of the Track Circuit Reader Antenna Baffle for High-Speed Trains.

The track circuit reader (TCR) is an important part of train control systems. This paper reports a failure of the TCR antenna baffle, which is used to prevent the TCR antenna from being struck by foreign objects. The designed service life of the baffle is 4.8 million kilometers, but serious cracking was found during routine maintenance after only 0.67 million kilometers of operation. In order to avoid the hidden danger brought by the incident to the safe operation of the train, it is necessary to conduct a complete failure analysis of the failed TCR antenna baffle. Therefore, a comprehensive investigation of the base material, cleaning agents, crack morphologies, etc., was carried out, and the failure environment of the antenna baffle was verified by experiment. The final results show that the environmental stress cracking is the root cause of the failed antenna baffle, and the multiple bubbles produced by the formed process of the antenna baffle are another important cause. According to the conclusions, the solutions to prevent the reoccurrence of such failures are proposed. After these solutions are adopted, the number of failed antenna baffles is greatly reduced, which fully proves the correctness of this analysis.

A New Nomogram for Predicting the Risk of Intracranial Hemorrhage in Acute Ischemic Stroke Patients After Intravenous Thrombolysis.

Background: We aimed to develop and validate a new nomogram for predicting the risk of intracranial hemorrhage (ICH) in patients with acute ischemic stroke (AIS) after intravenous thrombolysis (IVT). Methods: A retrospective study enrolled 553 patients with AIS treated with IVT. The patients were randomly divided into two cohorts: the training set (70%, n = 387) and the testing set (30%, n = 166). The factors in the predictive nomogram were filtered using multivariable logistic regression analysis. The performance of the nomogram was assessed based on the area under the receiver operating characteristic curve (AUC-ROC), calibration plots, and decision curve analysis (DCA). Results: After multivariable logistic regression analysis, certain factors, such as smoking, National Institutes of Health of Stroke Scale (NIHSS) score, blood urea nitrogen-to-creatinine ratio (BUN/Cr), and neutrophil-to-lymphocyte ratio (NLR), were found to be independent predictors of ICH and were used to construct a nomogram. The AUC-ROC values of the nomogram were 0.887 (95% CI: 0.842-0.933) and 0.776 (95% CI: 0.681-0.872) in the training and testing sets, respectively. The AUC-ROC of the nomogram was higher than that of the Multicenter Stroke Survey (MSS), Glucose, Race, Age, Sex, Systolic blood Pressure, and Severity of stroke (GRASPS), and stroke prognostication using age and NIH Stroke Scale-100 positive index (SPAN-100) scores for predicting ICH in both the training and testing sets (p < 0.05). The calibration plot demonstrated good agreement in both the training and testing sets. DCA indicated that the nomogram was clinically useful. Conclusions: The new nomogram, which included smoking, NIHSS, BUN/Cr, and NLR as variables, had the potential for predicting the risk of ICH in patients with AIS after IVT.

Failure Analysis and Prevention of Extraction Column for Methyl Methacrylate Production: Application of the 'Safety Design' Concept.

To ensure safety and prevent failure of engineering equipment throughout its lifespan, the concept of 'Safety Design' is proposed, which covers all the cradle-to-grave phases of engineering equipment, considers at least ten essential factors of failure causes, and conducts root cause analysis at three different scales, in order to proactively control the safety risks before the occurrence of failure rather than passively conduct the remedial measures after failure. Herein, in order to demonstrate how to implement this effective and efficient concept in engineering practice, a case study of failure analysis and prevention is addressed on the extraction column in the production line for methyl methacrylate. Based on the analysis results, the causes were finally determined to be all derived from the stages before operation, including inappropriate design, limited quality inspection of fabrication and installation. Pertinent countermeasures were then proposed from the 'Safety Design' point of view, which would not only solve the failure problem for this sole equipment but also contribute to safety risk control of other engineering equipment before operation.

Additive Preparation of Conductive Circuit Based on Template Transfer Process Using a Reusable Photoresist.

To solve the problems of a conventional subtractive process for preparing conductive circuits, numerous alternative additive processes have been investigated, such as screen or inkjet printing, selective electroless plating, laser-induced forward transfer, etc. They all lead to a simpler procedure, less pollution, and finer line width but are still faced with difficulties like low conductivity and thickness, poor adhesion, and high cost. PDMS is a kind of material with low surface energy, leading to low adhesion with adhesive. Under these circumstances, a simple template transfer process for additively preparing conductive circuits is reported. The process to form the template includes the preparation of a photolithographic mask on the carrier copper foil and adsorption of PDMS anti-adhesion coating. Followed by metal deposition through electroplating on the template, the conductive circuits are transferred to the target substrate. Thus, the designed conductive circuits on various substrates including paper and cloth are formed. The template can be used again after being reimmersed into PDMS anti-adhesion coating. The components and the concentration of the coating are carefully discussed, and the mechanism of anti-adhesion is also researched by EIS and XPS. The copper circuits show a line width of 10 µm, a peeling strength of 7.11 N/cm, and a resistivity of 1.93 µΩ·cm, which is similar to that of bulk copper. With low pollution and cost, high versatility, and good electrical and adhesion performance, the template transfer process shows a good application prospect in the large-scale production of flexible electronics like sensors, RFID tags, etc.

Application of bone transgenic zebrafish in anti-osteoporosis chemical screening.

BACKGROUND: The zebrafish (Danio rerio) has recently been shown to be an ideal model to study bone disease including osteoporosis. The zebrafish osteoporosis model could be induced by glucocorticoid treatment with chemical staining for reflecting the level of bone mineralization. However, this methodology was unstable. Here, we developed a novel methodology to directly evaluate the bone mass and density. METHODS: We generated and used the bone of transgenic zebrafish Tg (ola.sp7:nlsGFP) to evaluate the bone mass and density by measuring the areal extent and the integrated optical density (IOD) of enhanced green fluorescent protein (eGFP). This methodology was further compared with the traditional chemically stained method showing the bone mineralization. Furthermore, genes related to zebrafish osteoporosis were analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: Our results of new methods were consistent with those from chemically stained fish, following glucocorticoid-induction or epimedium flavonoid (FE)-rescue treatments. qRT-PCR analyses on mRNA levels revealed that glucocorticoid induces osteoporosis by downregulating the expression of osteoblast-related factors osterix, osteocalcin, and osteopontin, and upregulating the expression of osteoclast-related factor tartrate-resistant acid phosphatase. In FE-rescued fish, the expression of osteogenic factors osterix, osteocalcin, and osteopontin were increased. CONCLUSION: Compared to the traditional chemical staining methods, the new osteoporosis model using Tg(ola.sp7:nlsGFP) is more convenient and efficient for studying osteoporosis in vivo, and especially for high-throughput anti-osteoporosis drug screening.

The Circular RNA Interacts with STAT3, Increasing Its Nuclear Translocation and Wound Repair by Modulating Dnmt3a and miR-17 Function.

Delayed or impaired wound healing is a major health issue worldwide, especially in patients with diabetes and atherosclerosis. Here we show that expression of the circular RNA circ-Amotl1 accelerated healing process in a mouse excisional wound model. Further studies showed that ectopic circ-Amotl1 increased protein levels of Stat3 and Dnmt3a. The increased Dnmt3a then methylated the promoter of microRNA miR-17, decreasing miR-17-5p levels but increasing fibronectin expression. We found that Stat3, similar to Dnmt3a and fibronectin, was a target of miR-17-5p. Decreased miR-17-5p levels would increase expression of fibronectin, Dnmt3a, and Stat3. All of these led to increased cell adhesion, migration, proliferation, survival, and wound repair. Furthermore, we found that circ-Amotl1 not only increased Stat3 expression but also facilitated Stat3 nuclear translocation. Thus, the ectopic expressed circ-Amotl1 and Stat3 were mainly translocated to nucleus. In the presence of circ-Amotl1, Stat3 interacted with Dnmt3a promoter with increased affinity, facilitating Dnmt3a transcription. Ectopic application of circ-Amotl1 accelerating wound repair may shed light on skin wound healing clinically.

Additive Fabrication of Conductive Patterns by a Template Transfer Process Based on Benzotriazole Adsorption As a Separation Layer.

The traditional subtractive process to fabricate conductive patterns is environmentally harmful, wasteful, and limited in line width. The additive process, including direct printing of conductive paste or ink, direct printing of catalytic ink, laser-induced forward transfer, etc., can solve these problems. However, the current additive process also faces many difficulties such as low electrical and adhesion properties, low pattern thickness, high cost, etc. Benzotriazole (BTA), as widely used corrosion inhibitor, can be adsorbed onto a copper surface. The electroplated copper film on BTA-adsorbed copper foil shows poor adhesion. On the basis of this phenomenon, a novel template transfer process to additively fabricate conductive patterns has been developed. A permeant antiadhesive mask is printed on carrier copper foil, and then, BTA is adsorbed onto the exposed area of the carrier foil, thus forming the template. The template is electroplated to grow conductive patterns in the exposed parts, and then can be adhered to the flexible substrate. The substrate is peeled off, with the transfer of the conductive patterns to the substrate, to form the designed conductive patterns on PET. By reimmersing the template into BTA solution, the template can be used again. The mechanism of BTA adsorption and the reason for the low peeling strength are researched using Raman spectra, XPS and electrochemical impedance spectroscopy. Copper patterns more than 20 µm in thickness can be prepared on PET, the resistivity of the prepared copper patterns is 2.01 µΩ cm, which is about the same as bulk copper, and the peeling strength of the pattern on PET is measured to be 6.97 N/cm. This template transfer process, with no waste, low pollution, high electrical and adhesion properties, and low cost, shows high potential in the large scale manufacturing of electronic devices, such as RFID circuitry, FPCs, etc.

Synergistic inhibitory effect of scopoletin and bisdemethoxycurcumin on Tetranychus cinnabarinus (Boisduval) (Acari: Tetranychidae).

The study aimed to investigate the synergistic activity of scopoletin and bisdemethoxycurcumin (BDMC) against the carmine spider mite Tetranychus cinnabarinus. The acaricidal activities of mixtures of scopoletin and BDMC against T. cinnabarinus female adults were measured via slide dipping and leaf disc dipping. A mathematical model was established by SPSS software. Bioassays for multiple effects including contact, ovicidal, cowpea root intake, repellency and oviposition inhibitory activity were carried out. The optimal mass ratio of the mixture of scopoletin and BDMC (at their respective LC(50)), the median lethal concentration (LC(50)) and the co-toxicity coefficient were 7:6, 0.19 mg/mL and 129, respectively. LC(50) values of contact activities of the mixture at optimal ratio against adults, nymphs, larvae, and eggs were 0.19, 0.18, 0.06, and 1.52 mg/mL, respectively. LC(50) values of cowpea root intake activity against adults and nymphs were 5.62 and 6.52 mg/mL, respectively. The highest repellent rates against adults and nymphs were 69.5% and 72.5%, respectively. The mixture of scopoletin and BDMC at the optimal mass ratio possessed strong acaricidal activity against T. cinnabarinus at various developmental stages.

Flexible, Transparent, Thickness-Controllable SWCNT/PEDOT:PSS Hybrid Films Based on Coffee-Ring Lithography for Functional Noncontact Sensing Device.

Flexible transparent conductive films (FTCFs) as the essential components of the next generation of functional circuits and devices are presently attracting more attention. Here, a new strategy has been demonstrated to fabricate thickness-controllable FTCFs through coffee ring lithography (CRL) of single-wall carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate ( PEDOT: PSS) hybrid ink. The influence of ink concentration and volume on the thickness and size of hybrid film has been investigated systematically. Results show that the final FTCFs present a high performance, including a homogeneous thickness of 60-65 nm, a sheet resistance of 1.8 kohm/sq, a visible/infrared-range transmittance (79%, PET = 90%), and a dynamic mechanical property (>1000 cycle, much better than ITO film), respectively, when SWCNT concentration is 0.2 mg/mL, ink volume is 0.4 µL, drying at room temperature. Moreover, the benefits of these kinds of FTCFs have been verified through a full transparent, flexible noncontact sensing panel (3 × 4 sensing pixels) and a flexible battery-free wireless sensor based on a humidity sensing mechanism, showing excellent human/machine interaction with high sensitivity, good stability, and fast response/recovery ability.

Facile and Scalable Preparation of Solid Silver Nanoparticles (<10 nm) for Flexible Electronics.

Metal conductive ink for flexible electroncs has exhibited a promising future recently. Here, an innovative strategy was reported to synthesize silver nanocolloid (2.5±0.5 nm) and separate solid silver nanoparticles (<10 nm) effectively. Specifically, silver nitrate (AgNO3) was used as a silver precursor, sodium borohydride (NaBH4) as a reducing agent, fatty acid (CnH2n+1COOH) as a dispersant agent, and ammonia (NH3·H2O) and hydrochloride (HCl) as a pH regulator and complexing agent in aqueous solution. The main mechanism is the solubility changes of fatty acid salts (CnH2n+1COO-NH4+) and fatty acid (CnH2n+1COOH) coated on the synthesized silver nanoparticles (NPs) in aqueous solution. This change determines the suspension and precipitation of silver NPs directly. The results show that when n in dispersant is 12 and molar ratio (C12H24O2/AgNO3) is 1.0, the separation yield of silver NPs is up to 94.8%. After sintering at 125 °C for 20 min, the as-prepared conductive silver nanoink (20 wt %) presents a satisfactory resistivity (as low as 6.6 µΩ·cm on the polyester-PET substrate), about 4 times the bulk silver. In addition, the efficacy of the as-prepared conductive ink was verified with the construction of a radio frequency antenna by inkjet printing and conductive character pattern (Fudan-Fudan) by direct wiring, showing excellent electrical performance.

Flexible pressure sensing film based on ultra-sensitive SWCNT/PDMS spheres for monitoring human pulse signals.

Flexible pressure sensors are essential components of electronic skins for future attractive applications ranging from human healthcare monitoring to biomedical diagnostics to robotic skins to prosthetic limbs. Here, we report a new kind of flexible pressure sensing film based on ultrasensitive single wall carbon nanotube (SWCNT)/polydimethylsiloxane (PDMS) spheres. These spheres with the diameter of 600 ± 20 µm were prepared using the dipping method, and were further sandwiched by flexible electrodes using a stack of double-sided tape. The sensing mechanism of this device was analyzed by classic thin plate theory for circular plate deflection. Its sensitivity was further optimized by the synthesis of sensitive materials and geometrical design of device parameters. Ultimately, the developed sensing film exhibited a maximum sensitivity of 46.7% kPa-1 to resistance, great durability over 15 000 cycles, and very rapid mechanical responses (a few milliseconds). We also demonstrated that our sensing film can be used to detect the location and distribution of finger pressure, as well as to map the fingertip pulse signals, jugular venous pulse (JVP) signals and wrist pulse signals of the testers of different ages effectively.

Molecular cloning and expression of glutathione S-transferases involved in propargite resistance of the carmine spider mite, Tetranychus cinnabarinus (Boisduval).

The carmine spider mite (CSM) Tetranychus cinnabarinus has become a serious pest in China and has developed resistance to acaricide propargite as it is used to control mites worldwide including T. cinnabarinus. In this study, a resistant colony of T. cinnabarinus, PRR34 (37.78-fold resistant ratio), was established after 34 generations of propargite selection, and cross-resistance patterns of 7 other acaricides were determined in comparison with a susceptible strain (SS). The contribution of detoxification enzymes to propargite tolerance were investigated using biological, biochemical and molecular approaches. Enzyme inhibitor synergist tests suggested glutathione S-transferases (GST) involvement in propargite-resistance of PRR34, and GST activity against 1-chloro-2,4-dinitrobenzene (CDNB) was correlated with the development of resistance. Eight novel GST genes (TcGSTd1, TcGSTd2, TcGSTm1, TcGSTm2, TcGSTm3, TcGSTm4 and TcGSTm5) were cloned, and phylogenetic analysis showed that the eight GST genes were most closely related to GST family delta and mu from Tetranychusurticae. Quantitative RT-PCR revealed that the expression level of GSTs in PPR34 strain increased in larvae, nymphs and adults, while decreased in eggs compared with that of SS. Collectively, these results support a role of GSTs in mediating resistance to propargite in the PRR34 strain. TcGSTd1,TcGSTd2 and TcGSTm2 genes might play significant roles in propargite resistance of CSM, especially at adult stage. This is the first attempt to define specific genes involved in GST mediated propargite resistance of T. cinnabarinus at the transcriptional level.

Fabrication of copper patterns on flexible substrate by patterning-adsorption-plating process.

A novel patterning-adsorption-plating process to additively fabricate copper patterns is developed. Functional ink with ion-adsorption nanoparticles was inkjet printed on PET substrate to form the patterned adsorption film. Catalytic ion was adsorbed by amino groups in the adsorption film, and catalyzed the electroless plating of copper. The mercapto groups introduced to the film enhance the reliability of the patterns. Specific solvent used in the ink increase the surface roughness of the adsorption film, leading to a better adhesion of the patterns. The prepared copper patterns show excellent conductivity about the same with bulk copper and good adhesion on PET.

[Lethal effects of scopoletin and bisdemethoxycurcumin against Tetranychus cinnabarinus Boisd. (Acari: Tetranychidae): a simulation study].

By using slide-dip bioassay method under laboratory condition, an investigation was made on the lethal effects of scopoletin, bisdemethoxycurcumin (BDMC), and their combination at an optimal mass ratio (7:6) of scopoletin to BDMC against the adult females of Tetranychus cinnabarinus Boisd. A time-dose mortality model (TDM) was established, which passed the Hosmer-Lemeshow test. The sensitivity of the adult females to the concentration change of the acaricides was in the sequence of scopoletin > optimal mass ratio of scopoletin to BDMC > BDMC. The peak mortality of the female adults was found at 32, 28 and 32 h after treated with BDMC, scopoletin, and their combination at the optimal mass ratio, respectively. The values of the LC50 and LC90 at 48 h after treated with BDMC, scopoletin, and their combination at the optimal mass ratio were 0.3324, 0.2035 and 0.2195 mg x mL(-1), and 2.1198, 0.9521 and 1.1617 mg x mL(-1), and the median lethal time (LT50) of BDMC, scopoletin, and their combination at the optimal mass ratio was 7.4, 6.0 and 6.1 h at the concentration 1.0 mg x mL(-1), and 6.4, 4.8 and 5.0 h at the concentration 2.0 mg x mL(-1), respectively. The acaricidal activity and time-dose response of the optimal combination of scopoletin and BDMC were closer to those of scopoletin, suggesting a synergistic acaricidal activity of the combination of scopoletin and BDMC, which was worthy to be developed for application.

In situ transmission electron microscopy observation of microstructure and phase evolution in a SnO2 nanowire during lithium intercalation.

Recently we have reported structural transformation features of SnO(2) upon initial charging using a configuration that leads to the sequential lithiation of SnO(2) nanowire from one end to the other (Huang et al. Science2010, 330, 1515). A key question to be addressed is the lithiation behavior of the nanowire when it is fully soaked into the electrolyte (Chiang Science2010, 330, 1485). This Letter documents the structural characteristics of SnO(2) upon initial charging based on a battery assembled with a single nanowire anode, which is fully soaked (immersed) into an ionic liquid based electrolyte using in situ transmission electron microscopy. It has been observed that following the initial charging the nanowire retained a wire shape, although highly distorted. The originally straight wire is characterized by a zigzag structure following the phase transformation, indicating that during the phase transformation of SnO(2) + Li ↔ Li(x)Sn + Li(y)O, the nanowire was subjected to severe deformation, as similarly observed for the case when the SnO(2) was charged sequentially from one end to the other. Transmission electron microscopy imaging revealed that the Li(x)Sn phase possesses a spherical morphology and is embedded into the amorphous Li(y)O matrix, indicating a simultaneous partitioning and coarsening of Li(x)Sn through Sn and Li diffusion in the amorphous matrix accompanied the phase transformation. The presently observed composite configuration gives detailed information on the structural change and how this change takes place on nanometer scale.