The development of an on-chip microinitiator with a built-in safety-and-arming device.

With the development of small size and high energy output of initiators, how to improve the safety of the system becomes an urgent problem. Therefore, a novel Micro-electro-mechanical System (MEMS) initiator with a built-in safety-and-arming (S&A) device is introduced in this paper. The MEMS initiator is composed of the MEMS ignitor and the MEMS S&A device. A movable barrier with a fire hole is controlled by the MEMS S&A device. Driven by the electro-thermal principle, the barrier can be moved backward or forward to open or close the fire channel, and the status conversion between the armed mode and the safe mode can be realized. The test results show that under specific control signals, the MEMS S&A device can generate 1 mm output displacement. Under the armed mode, the flame can burst out from the fire channel when stimulated by 64 V pulse voltage. Under the safe mode, the barrier hit by the flame can stay intact, and the explosion energy is blocked in the fire channel successfully. The silicon wafer and silicon-on-insulator wafer are used to fabricate the MEMS S&A device. Integrated with the MEMS ignitor, the total chip size is 11 × 12 × 1.2 mm3.

The Hybrid Fabrication Process of Metal/Silicon Composite Structure for MEMS S&A Device.

The micro-electromechanical system (MEMS) safety-and-arming (S&A) device has the features of integration and miniaturization, which is one of the important directions of weapon development. Confined by the fabrication process, the silicon-based devices are too fragile, and the metal-based devices are low precision. In order to solve the contradiction between high precision and high structure strength, a metal/silicon composite structure is proposed in this paper, and a hybrid fabrication process is introduced. This new method mainly consists of metal sputtering, electroplating, and (inductively-coupled-plasma) ICP etching. As the resolution of the thick dry film is limited, the process of a femtosecond laser is applied to refine the structure, and the Ni plate (a block of 1 mm × 3 mm × 0.3 mm with a cavity of ϕ 0.85 mm × 0.3 mm in the center) is fabricated on the silicon-on-insulator (SOI) wafer successfully. After the double sides are etched by ICP, the SOI wafer is immersed in a buffered-oxide-etch (BOE) etchant to remove the buried layer. The cover plate acts as the encapsulation and is bonded with the SOI wafer by the epoxy glue. Then, the temporary support beam of the device is broken by the probe, and the suspended composite structure can be fully released. The hybrid process is the integration of the silicon-based process and the metal-based process, which can combine the advantages of both high precision and a high structure strength. The process proposed here is suitable for the application of weapon miniaturization.

Research on an On-Chip MEMS Based Safety and Arming Device with a Mechanical Encryption System.

The design and characterization of microelectromechanical systems (MEMS) based on-chip SAD (Safety and Arming Device) are proposed. An encryption system has been integrated into the device to enhance its reliability during the electromagnetic interference. The conversion between safe status and arm status is reversible due to the bidirectional actuation design of the slider and pawl on the SOI (Silicon on Insulator) chip, being driven by the chevron electrothermal actuators. The width of each tooth on the slider, which contains coding information, is different from that of its adjacent neighbor. Additionally, the different teeth width, respectively 32 µm, 82 µm, requiring different decoding displacement of 100 µm and 150 µm, corresponds to the different decoding voltage of 13.5 V and 14.8 V. The travel range of interrupter in the SAD will only be limited by the chip dimension and be able to cover the motion of ±1 mm in the present research, due to the capability of motion retention. Finally, the SAD is integrated with a copper azide exploding chip to measure the average velocity of the titanium flyer for the application feasibility validation.

Construction of Substituted Benzenes via Pd-Catalyzed Cross-Coupling/Cyclization Reaction of Vinyl Halides and Terminal Alkynes.

A tandem Sonogashira coupling/cyclization/aromatization sequence of ß-halo vinyl sulfones/ketones with terminal alkynes has been developed for the construction of benzene rings. Polysubstituted functionalized benzenes containing a sulfonyl or an acyl group could be obtained in up to 95% yield.

Enhanced HBsAg synthesis correlates with increased severity of fibrosis in chronic hepatitis B patients.

BACKGROUND AND AIMS: Little is known about whether low serum HBsAg levels result from impaired HBsAg synthesis or a reduced number of hepatocytes caused by advanced liver fibrosis. Therefore, we investigated the capacity for HBsAg synthesis in a cross-sectional cohort of treatment-naïve chronic hepatitis B patients. METHODS: Chronic hepatitis B patients (n = 362) were enrolled; liver biopsies were performed and liver histology was scored, and serum HBsAg and HBV DNA levels were investigated. In the enrolled patients, 183 out of 362 have quantitative serum HBsAg levels. Tissue HBsAg was determined by immunohistochemistry. RESULTS: A positive correlation between serum HBsAg and HBV DNA levels was revealed in HBeAg(+) patients (r = 0.2613, p = 0.0050). In HBeAg(+) patients, serum HBsAg and severity of fibrosis were inversely correlated (p = 0.0094), whereas tissue HBsAg levels correlated positively with the stage of fibrosis (p = 0.0280). After applying the mean aminopyrine breath test as a correction factor, adjusted serum HBsAg showed a strong positive correlation with fibrosis severity in HBeAg(+) patients (r = 0.5655, p<0.0001). The adjusted serum HBsAg values predicted 'moderate to severe' fibrosis with nearly perfect performance in both HBeAg(+) patients (area under the curve: 0.994, 95% CI: 0.983-1.000) and HBeAg(-) patients (area under the curve: 1.000, 95% CI: 1.000-1.000). CONCLUSIONS: Although serum HBsAg levels were negatively correlated with fibrosis severity in HBeAg(+) patients, aminopyrine breath test-adjusted serum HBsAg and tissue HBsAg, two indices that are unaffected by the number of residual hepatocytes, were positively correlated with fibrosis severity. Furthermore, adjusted serum HBsAg has an accurate prediction capability.

Effects of sleep deprivation on serum testosterone concentrations in the rat.

Sleep deprivation (SD) leads to decreases in circulating levels of testosterone with unknown mechanisms. We tested the hypothesis that decreased testosterone levels associated with SD may be caused by serotonin-mediated inhibition of its production. Male rats were subjected to SD for 24 or 48 h using the dish-over-water-method with a Rechtschaffen apparatus. Serum testosterone, corticosterone and serotonin (5-HT) concentrations were assessed thereafter, as were testicular StAR and 5-HT 2 receptor levels. SD, regardless of duration led to significant decreases in serum testosterone levels and testicular steroid acute regulatory protein (StAR) protein expression, while 5-HT levels were significantly elevated (all P<0.05). Corticosterone concentrations were significantly increased in 48 h SD rats (P<0.05). In primary Leydig cell cultures, 5-HT decreased chorionic gonadotropin-induced testosterone secretion and StAR expression, which appeared to be dependent on 5-HT 2 receptor activation but independent of cyclic AMP signaling. These findings suggest that decreased serum testosterone levels in SD rats may be the result of 5-HT-related inhibition of testosterone production and decreased testicular expression of StAR protein.

[Predictors and scoring system for sustained complete response to conventional interferon-alpha therapy on chronic hepatitis B].

OBJECTIVE: To establish a predictive scoring system which may serve for the prediction of sustained response to conventional interferon-alpha (IFN-alpha) treatment on chronic hepatitis B. METHODS: A total of 474 IFN-alpha treated hepatitis B virus e antigen (HBeAg)-positive patients were enrolled in the present study. The patients' baseline characteristics, such as age, gender, aminotransferases, activity grading (G) of intrahepatic inflammation, score (S) of liver fibrosis, hepatitis B virus (HBV) DNA and genotype were evaluated; therapy duration and response of each patient at the 24th wk after cessation of IFN-alpha treatment were also recorded. A predictive scoring system for a sustained complete response (CR) to IFN-alpha therapy was established based on genetic algorithm. About 10% of the patients were randomly drawn out as the test set. Responses to IFN-alpha therapy were divided into CR, partial response (PR) and non-response (NR). The mixed set of PR and NR was recorded as PR + NR. RESULTS: For the scoring system, the sensitivity and specificity were 78.8% and 80.6%, respectively. CONCLUSION: This SCR scoring system has satisfying prediction efficiency and is easily employed in clinical practice. With this scoring system, practitioners can propose individualized decisions that have an integrated foundation on both evidence-based medicine and personal characteristics.

Precise prediction model and simplified scoring system for sustained combined response to interferon-alpha.

AIM: To establish a predictive algorithm which may serve for selecting optimal candidates for interferon-alpha (IFN-alpha) treatment. METHODS: A total of 474 IFN-alpha treated hepatitis B virus e antigen (HBeAg)-positive patients were enrolled in the present study. The patients' baseline characteristics, such as age, gender, blood tests, activity grading (G) of intrahepatic inflammation, score (S) of liver fibrosis, hepatitis B virus (HBV) DNA and genotype were evaluated; therapy duration and response of each patient at the 24th wk after cessation of IFN-alpha treatment were also recorded. A predictive algorithm and scoring system for a sustained combined response (CR) to IFN-alpha therapy were established. About 10% of the patients were randomly drawn as the test set. Responses to IFN-alpha therapy were divided into CR, partial response (PR) and non-response (NR). The mixed set of PR and NR was recorded as PR+NR. RESULTS: Stratified by therapy duration, the most significant baseline predictive factors were alanine aminotransferase (ALT), HBV DNA level, aspartate aminotransferase (AST), HBV genotype, S, G, age and gender. According to the established model, the accuracies for sustained CR and PR+NR, respectively, were 86.4% and 93.0% for the training set, 81.5% and 91.0% for the test set. For the scoring system, the sensitivity and specificity were 78.8% and 80.6%, respectively. There were positive correlations between ALT and AST, and G and S, respectively. CONCLUSION: With these models, practitioners may be able to propose individualized decisions that have an integrated foundation on both evidence-based medicine and personal characteristics.