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Functional composite films were successfully prepared from cellulose, graphite (GP), and polyaniline (PANI) using a combination of physical and chemical processes. Cellulose was dissolved in N-methylmorpholine-N-oxide monohydrate (NMMO) and regenerated in water to form the matrix. GP was dispersed in the NMMO solvent prior to the dissolution of the cellulose, and PANI was deposited on the surfaces of the cellulose/GP films by in situ chemical polymeriz ation. The structures of the PANI/cellusose/GP composite films were investigated using X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), and SEM/energy-dispersive X-ray spectroscopy. The mechanical strengths, thermal stabilities, conductivities, and antibacterial activities of the films were studied in detail. The results showed that GP formed a multilayered structure in the cellulose matrix and that the PANI nanoparticles were tightly wrapped on the film surface. The film thickness increased from 40 mm to 100 mm after the addition of GP and PANI. The tensile strength of the composite films was 80∼ 107 MPa, with the elongation at break being 3%∼ 10%. The final residual weight of the composite films was as high as 65%, and the conductivity of the composite films reached 14.36 S/m. The cellulose matrix ensured that the films were flexible and exhibited desirable mechanical properties, while the GP filler significantly improved the thermal stability of the films. The PANI coating acted as a protective layer during burning and provided good electrical conductivity and antibacterial activity against Escherichia coli; both of these characteristics were slightly enhanced by the incorporation of GP. These PANI/cellulose/GP composite films should be suitable for use in electronics, antistatic packing, and numerous other applications. [ABSTRACT FROM AUTHOR]

Despite its biodegradability, adeq uate cohesive strength and comparatively low cost, the use of cooked starch as a paper coating binder is limited due to its high viscosity and serious negative impact on the gloss. Starch-based bio-latex with siz e in the nanometer or sub-micrometer range has been developed recently to overcome these shortcomings. In this study, ultrafine starch particle (UFSP) was prepared by mechanical milling using a DYNO mill in combination with light chemical pretreatment. Model coating colors containing different dosages of UFSP were applied to base paper and the properties of the coated papers were evaluated. The results showed that the UFSP was disc-shaped with a median particle diameter of 167 nm. Water retention capacity of the coating colors was improved considerably with the addition of UFSP, i.e., the water retention value decreased by nearly 40% when styrene-butadiene latex was replaced by UFSP at a dosage of 3 pph (per hundred parts of pigment). The high shear rate viscosities of the coating colors containing no more than 2 pph of USFP were similar to that of the control coating color at shear strain rate higher than 2000 s-1The properties and performances of the coated papers were comparable to the control coated paper with single synthesiz ed latex binder. The gloss and the print gloss of paper samples with or without USFP were 59.7% and 58.2%, 79.0% and 78.8%, respectively. Surface strength of paper samples with or without USFP were 0.96 and 0.90 m/s, respectively, while the ink absorptivity values were 34% and 33%. This study demonstrates a promising approach to obtain submicrometer sized starch for paper coating. [ABSTRACT FROM AUTHOR]

Background: This study aims to provide a reference for the diagnosis of iodine deficiency disorder by evaluating the normal thyroid iodine content by energy spectrum computed tomography (CT) and calculating the iodine content ratio of thyroid to sternocleidomastoid. Methods: The thyroid glands of 226 patients were scanned by energy spectrum CT, and the images were analyzed using the GSI Viewer software. Based on the imaging findings, the iodine levels of the thyroid lobes as well as the bilateral sternocleidomastoids were evaluated, and their iodine content ratios were calculated. Results: No statistically significant difference was found in the thyroid iodine content between the left and right thyroid lobes (p > 0.05). However, there was a significant difference in the thyroid iodine content between men and women (p < 0.01). Additionally, the thyroid iodine content was found to decrease gradually with age. The iodine content ratio of thyroid to sternocleidomastoid was 96.6271 ± 33.2442. Conclusion: Gemstone energy spectrum CT can be used for the measurement of thyroid iodine content in the human body. It can play a significant role in the diagnosis of iodine deficiency disorder. [ABSTRACT FROM AUTHOR]

Background. Laparoscopic cyst excision and Roux-en-Y hepaticojejunostomy for treating congenital choledochal cysts (CCCs) have proved to be efficacious in children. Its safety and efficacy in adult patients remain unknown. The purpose of this study was to determine whether the laparoscopic procedure was feasible and safe in adult patients. Methods. We reviewed 35 patients who underwent laparoscopic operation (laparoscopic group) and 39 patients who underwent an open procedure (open group). The operative time, intraoperative blood loss, time until bowel motion recovery, duration of drainage, postoperative stay, time until resumption of diet, postoperative complications, and perioperative laboratory values were recorded and analyzed in both groups. Results. The operative time was longer in the laparoscopic group and decreased significantly with accumulating surgical experience (P < 0.01). The mean intraoperative blood loss was significantly lower in the laparoscopic group (P < 0.01). The time until bowel peristalsis recovery, time until resumption of diet, abdominal drainage, and postoperative stay were significantly shorter in the laparoscopic group (P < 0.01). The postoperative complication rate was not higher in the laparoscopic group than in the open group (P > 0.05). Conclusions. Laparoscopic cyst excision and hepaticojejunostomy are a feasible, effective, and safe method for treating CCCs in adult patients. [ABSTRACT FROM AUTHOR]

Meltable thermoplastic polyimide resins (MTPI) with designed polymer backbones and controlled molecular weights for advanced microelectronic packaging substrate application have been synthesized by thermal polycondensation of aromatic dianhydride and aromatic diamine in presence of endcapping agent. The thermoplastic polyimide resins could be dissolved in organic solvents to give low viscosity solutions, which were then employed to impregnate E-glass cloth (EG) to yieldMTPI/EG prepregs. After removal of the organic volatile, theMTPI/EG prepregs were plied up and then melt processed to give MTPI/EG composite laminates with high quality. Experimental results demonstrated that the MTPI/EG composite laminates showed desirable characteristics, including: (1) excellent thermal stability; (2) good mechanical properties; (3) great electrical insulating and dielectric properties; as well as (4) high peel strength between copper foil and the composite surface. [ABSTRACT FROM AUTHOR]

Gastric bypass is the most popular technique in obesity therapy. We hypothesize that bypass surgery can help to control the body weight in morbid obesity, and this effect can be enhanced by vagus dissection. Thirty-six Wistar rats were used in this investigation. They were randomly allocated into six groups. Rats in the gastric bypass group (GB1 and GB2) and the bypass with vagus dissection group (VD1 and VD2) received surgery. Rats in the control group (CO1 and CO2) received sham operation. Twenty days later, rats in the CO1, GB1, and VD1 groups were killed and data on body weights, food intakes, fasting glucose, plasma ghrelin and leptin levels, and GHS-R1a and leptin receptor protein expression in the hypothalamus were collected and summarized. One hundred days later, rats in the CO2, GB2, and VD2 groups were also killed and the same experiments were repeated. Body weights of rats were 258 ± 4.2 and 232 ± 2.4 g in the GB1 and VD1 groups, respectively, much lower than the CO1 group (303 ± 6.9 g). Body weights of rats were 316 ± 12.3 and 315 ± 10.3 g in the GB2 and VD2 groups, respectively, much lower than the CO2 group. Food intake in the VD1 group was lower than in the GB1 group, while there were no statistical differences between the VD2 and GB2 groups. Fasting glucose in the GB1 and GB2 groups was much lower than the CO1 and CO2 groups. Plasma ghrelin concentrations were much lower in the GB1 and VD1 groups compared to the CO1 group. One hundred days after surgery, the ghrelin concentrations in the GB2 and VD2 groups were also much lower than the CO2 group. Leptin concentrations decreased significantly with weight loss after bypass surgery. GHS-R1a protein expression in the hypothalamus was much lower in the GB1 and VD1 groups compared to the CO1 group. GHS-R1a protein expressions in the GB2 and VD2 groups were lower than the CO2 group. There were no statistical differences in leptin receptor expression in the hypothalamus (not shown). Vagus nerve dissection is effective on body weight control in the early stage, but not in the long term. The hypothalamus is important in weight control by modulating ghrelin and leptin expressions. Bypass surgery can modulate the expression of ghrelin and its receptor. Leptin is also modulated by bypass surgery. [ABSTRACT FROM AUTHOR]

The article discusses phenylethynyl-endcapped polyimide oligomers which were made through the polycondesation of an aromatic diamine mixture with varying aromatic dianhydrides in the presence of 4-phenyl-ethynylaniline. The synthesized characterization of polyimide oligomers is analyzed with particular focus paid to the chemical structure, thermal behavior, and melt rheological properties. It was found that the fluorinated oligomers had lower melt viscosities than those that were unfluorinated. Also, the melt viscosities were increased by adding more polymer molecular weights.

A novel trifunctional fluorine containing epoxy compound, 1,1,1-Tris(2,3-epoxypropoxyphenyl)-2,2,2-trifluoroethane (TEF) synthesized starting from 4-bromoanisole was cured with alicyclic anhydride or aromatic diamines to produce the epoxy resins. As comparison, commercial available Biphenol A 828 epoxy (BPA) was cured under the same conditions. Experimental results indicated that the cured TEF epoxy resins showed good thermal stability with onset thermal decomposition temperature (Td) of 363-388°C in nitrogen, glass transition temperature (Tg) of 210-287°C (determined by DMA) and coefficient of thermal expansion (CTE) ranged in 46.7-59.6 ppm/°C. The fluorine containing epoxy resins possessed outstanding mechanical properties with flexural strengths of 64-115 MPa, flexural moduli of 2.29-2.65 GPa. The epoxy resins also exhibited excellent electric insulating properties with volume resistivity of 1.19-8.15 x 1016 Ωcm and the dielectric constants at 1 MHz of 3.2-3.5 as well as low moisture absorption of 0.31-0.87%. As comparison with BPA resins, the trifunctional fluorine containing TEF resins exhibit higher Tg and improved dielectric properties as well as low CTE, which are promising candidates for advanced microelectronic packaging. [ABSTRACT FROM AUTHOR]

Derives a generalized characteristic equation describing the pulse shape and temporal width of both actively and passively Q-switched lasers. Pulse symmetry property; Reconstruction of the laser pulse waveform; Comparison of predictions with experiments for a diode-pumped Nd:YAG laser system that is passively Q-switched by a Cr:YAG absorber.

Rock breaking by laser-assisted disc cutters is a novel high-efficiency rock breaking mode that combines mechanical stress induced by the disc cutters with thermal cracking by laser. This paper presented a "step-by-step" simulation modeling concept, and conducted an in-depth study on potential influencing factors of simulation accuracy at each key step. First, the prediction accuracy of laser holes in laser drilling simulation was discussed. Second, the SHPB simulation and experiment were carried out to evaluate the accuracy of the selected material constitutive model in simulating the dynamic fracture damage of rock. Then, taking the laser-assisted rockpenetrating process of the scaled disc cutter as an example, the simulation prediction accuracy of rock-breaking by the disc cutter was analyzed. Finally, the simulation and experiment of laser-assisted disc cutter penetration into rock was carried out, and then the feasibility of the "step-by-step" concept was analyzed. The results show that: (1) in the laser drilling simulation, the predicted accuracy of laser hole size is higher when the power is low; with the laser power increases, the large amount of glass glaze will affect the subsequent modeling accuracy; (2) the HJC model can be used to simulate the transient nonlinear fracture damage behavior of granite; (3) the damage morphology of the granite obtained by the penetration simulation is highly similar to the experimental results, and the load curve should be corrected by the peak point fitting method. The results show the application prospects of the proposed numerical modeling method in future laser-assisted TBM tunnelling. [ABSTRACT FROM AUTHOR]

Focuses on the optimization of intracavity doubled passively Q-switched solid-state lasers. Two factors by which passively Q-switched can be optimized; Optimization of the peak power of second-harmonic generation; Comparison of the pulse characteristics of the laser with those of a fundamental peak power optimized laser at the same pump level.

Polyimide (PI) aerogels containing rigid-rod biphenyl, benzimidazole, and triphenylpyridine moieties have been developed. The flexible PI aerogels exhibited excellent thermal stability with glass-transition temperatures (Tg) higher than 350 °C. Initial porous structures in the PI aerogels could be maintained even after isothermal aging at 300 °C for 24 h in nitrogen. Furthermore, the weight losses of the aerogels after isothermal aging at 300 and 400 °C for 24 h in nitrogen were below 5 and 10wt%, respectively. [ABSTRACT FROM AUTHOR]

Polyimide aerogel with an intrinsically hydrophobic nature and a dielectric constant as low as 1.19 at a frequency of 2.75 GHz was synthesized by the polycondensation of an alicyclic dianhydride, an aromatic fluorinated diamine, and an amino-substituted polyhedral oligomeric silsesquioxane (POSS) end-capper, followed by a supercritical carbon dioxide drying procedure. [ABSTRACT FROM AUTHOR]

The article presents information on the treatment of long-term complications after primary surgery for congenital choledochal cysts (CCC). CCC is a relatively rare disease described by congenital cystic dilation of the extrahepatic and/or intrahepatic biliary ducts. It is frequently linked to an anomalous pancreaticobiliary junction.