Central wavelength tunable mechanism for temperature compensatedpackage of fiber Bragg gratings

The central wavelength of fiber Bragg grating (FBG) must be located in the specified channel band of wavelength division multiplexer (WDM) in optical communication network. Furthermore, the central wavelength also must he stable in the ambient temperature. A temperature compensated fixture Is therefore essential for the application of FBG. By the strength of materials, a theoretical model of the fully temperature compensated fixture can he derived for zero shift of central wavelength of FBG in ambient temperature. Besides, a microtunable mechanism for the pre-pulling force on the FBG is synthesized to adjust the central wavelength to a certain channel band. By this tunable mechanism one can calibrate effectively and efficiently the FBG in mass production of FBG based products     

Effect of process parameters on synthesis of aluminum nitride powder prepared by chemical vapor deposition

Ultrafine aluminum nitride (AlN) powders were obtained by the chemical vapor deposition (CVD) process via the AlCl₃-N₂-NH₃ system operated at various temperatures and different mixing modes of AlCl₃ and NH₃ gases. X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscope (TEM) and electron diffraction (ED) were utilized to study the effect of process parameters on the synthesis and characterization of the AlN powders. It had been shown that all of the obtained powders were exclusively identified to be the single phase AlN and were indifferent to the different mixing modes AlCl₃ and NH₃ gases. The yield of synthesized AlN powder was affected by the entries mixing position of the reacting gases of AlCl₃ and NH₃.The yield increased from 13% to 82% where the mixed position was shifted from the front edge to middle point of the quartz tube. On the other hand, the yield increased from 5% to 82% as the reaction temperature increased from 600°C to 1050°C. The morphology of the AlN powders was affected by the diameter of a feeding nozzle and mixing mode of AlCl₃ and NH₃ gases.     

Characterization of sputtered Ta-C-N film in the Cu/barrier/Si contact system

Characterization of sputtered tantalum carbon nitride (Ta-C-N) film in Cu/barrier/Si system was reported for the first time. With a 50∶50 wt.% TaC target and an optimum N₂/Ar flow rate (in sccm) ratio of 2/24, a 600 Å-thick sputtered Ta-C-N layer was shown metallurgically stable up to 650°C annealing for 30 min, which is about 100°C higher as compared to the case without nitrogen doping. Cu diffusion through the local defects or grain boundaries of the Ta-C-N barrier layer into Si substrate is the dominant factor responsible for the failure of the Ta-C-N barrier layer after high temperature annealing.     

Two systolic architectures for modular multiplication

The authors present two systolic architectures to speed up the computation of modular multiplication in RSA cryptosystems. In the double-layer architecture, the main operation of Montgomery's algorithm is partitioned into two parallel operations after using the precomputation of the quotient bit. In the non-interlaced architecture, we eliminate the one-clock-cycle gap between iterations by pairing off the double-layer architecture. We compare our architectures with some previously proposed Montgomery-based systolic architectures, on the basis of both modular multiplication and modular exponentiation. The comparisons indicate that our architectures offer the highest speed, lower hardware complexity, and lower power consumption     

Skeletonisation of three-dimensional object using generalized potential field

In this paper, the potential-based skeletonization approach for 2D medial axis transform (MAT), which identifies object skeleton as potential valleys using a Newtonian potential model in place of the distance function, is generalized to three dimensions. The generalized potential functions given by Chung (1998), which decay faster with distance than the Newtonian potential, is used for the 3D case. The efficiency of the proposed approach results from the fact that these functions and their gradients can be obtained in closed forms for polyhedral surfaces. According to the simulation results, the skeletons obtained with the proposed approach are closely related to the corresponding MAT skeletons. While the medial axis (surface) is 2D in general for a 3D object, the potential valleys, being one-dimensional, form a more realistic skeleton. Other desirable attributes of the algorithm include stability against perturbations of the object boundary, the flexibility to obtain partial skeleton directly, and low time complexity.     

High Risk of Viral Reactivation in Hepatitis B Patients with Systemic Lupus Erythematosus

HBV reactivation (HBVr) can occur in hepatitis B surface antigen (HBsAg)-positive and negative patients. Here, we determined the incidence of HBVr and its related hepatitis in patients with systemic lupus erythematosus (SLE). From 2000 to 2017, 3307 SLE cases were retrospectively reviewed for episodes of hepatitis. The incidence, long-term outcomes and risk factors associated with HBVr, including HBsAg reverse seroconversion (RS) were analyzed. Among them, 607 had available HBsAg status. Fifty-five (9.1%) patients were positive for HBsAg and 63 (11.4%) were HBsAg-negative/antibody to hepatitis B core antigen (anti-HBc)-positive (resolved hepatitis B infection, RHB). None of them received antiviral prophylaxis before immunosuppressive treatment. During a mean 15.4 years of follow-up, 30 (54.5%) HBsAg-positive patients developed HBVr and seven (23.3%) died of liver failure, whereas only two (3.2%) RHB cases experienced HBsAg reverse seroconversion (RS). Multivariate logistic regression analysis showed that age ≥ 40 years at diagnosis of SLE (HR 5.30, p < 0.001), receiving glucocorticoid-containing immunosuppressive therapy (HR 4.78, p = 0.003), and receiving glucocorticoid ≥ 10 mg prednisolone equivalents (HR 3.68, p = 0.003) were independent risk factors for HBVr in HBsAg-positive patients. Peak level of total bilirubin ≥ 5 mg/dL during HBVr was an independent factor of mortality (p = 0.002). In conclusion, the risk of HBVr was associated with glucocorticoid daily dose. Antiviral prophylaxis is mandatory for SLE patients diagnosed at age of ≥40 years who receive ≥ 10 mg daily dose of oral prednisone or equivalent.     

Dihydroisotanshinone I as a Treatment Option for Head and Neck Squamous Cell Carcinomas

Head and neck squamous cell carcinomas (HNSCCs) are the most common cancers of the head and neck, and their prevalence is rapidly increasing. HNSCCs present a clinical challenge because of their high recurrence rate, therapeutic resistance to radiation and chemotherapy drugs, and adverse effects. Hence, traditional Chinese herbal treatment may be advantageous to therapeutic strategies for HNSCCs. Danshen (Salvia miltiorrhiza), a well-known Chinese herb, has been extensively applied in treatments for various diseases, including cancer, because of its high degree of safety and low rate of adverse effects despite its unclear mechanism. Thus, we aimed to explore the possible anticancer effects and mechanisms of dihydroisotanshinone I (DT), a compound in danshen (extract from danshen), on HNSCCs. Three HNSCCs cell lines were used for in vitro studies, and a Detroit 562 xenograft mouse model was chosen for in vivo studies. Our in vitro results showed that DT could initiate apoptosis, resulting in cell death, and the p38 signaling partially regulated DT-initiated cell apoptosis in the Detroit 562 model. In the xenograft mouse model, DT reduced tumor size with no obvious adverse effect of hepatotoxicity. The present study suggests that DT is a promising novel candidate for anti-HNSCCs therapy.     

Effect of salts on the rheology of hydrocolloids from mulberry (Morus alba L.) leaves in concentrated domain

Rheological properties of 2–8% mulberry leaf hydrocolloids extracted by hot water (Hw) or sodium bicarbonate (Alk or Alk-v) were evaluated. Steady shear rheological results of mulberry leaf hydrocolloids indicated the structural behavior with a Newtonian viscosity at low shear rate and shear-thinning behavior over intermediate to high shear rate regime. As simulated by Carreau model, the characteristic time constant of mulberry leaf hydrocolloids increased, but the power-law behavior index decreased with increasing concentration. Results from the dynamic rheological experiments revealed that the behavior of 2% mulberry leaf hydrocolloid solutions were characteristic concentrated polymer solution. However, as the concentration was raised up to 4–8%, a gel-like behavior may occur depending on the extraction methods, possibly owing to the formation of aggregates at high polymer concentration. Furthermore, rheological properties of Alk and Alk-v were generally higher than those of Hw. Though mulberry leaf hydrocolloids were ionic polymers, the rheological properties in concentrated domain were not influenced pronouncedly by the addition of 0–200 mM of NaCl, KCl or MgCl₂. In contrast, under sufficiently high CaCl₂ concentration (68 mM or 200 mM for alkaline extracted and water extracted mulberry leaf hydrocolloids, respectively), formation of a three-dimensional gel network was observed, possibly due to the cross-linking of Ca²⁺ with carboxyl groups of mulberry leaf hydrocolloids in addition to charge screening effects.