AIM:To compare the outcomes of laparoscopic and open splenectomy and azygoportal devascularization for portal hypertension. METHODS:From June 2006 to March 2009, laparoscopic splenectomy and azygoportal disconnection (LSD) were performed on 28 patients with cirrhosis, bleeding due to portal hypertension, and secondary hypersplenism. Success was achieved in 26 patients. Demographic, intraoperative, and postoperative variables of the patients were compared. RESULTS:Success of laparoscopic splenectomy and azygoportal disconnection was achieved in all but two patients (7.14%) who required open splenectomy and azygoportal devascularization (OSD). The operation time was significantly longer in patients undergoing LSD than in those undergoing OSD (235 ± 36 min vs 178 ± 47 min, P < 0.05). The estimated intraoperative blood loss was much more in patients receiving OSD than in those receiving LSD (420 ± 50 mL vs 200 ± 30 mL, P < 0.01). The proportion of patients undergoing laparoscopic and open splenectomy and azygoportal disconnection who received transfusion of packed red blood cells during or after the operation was 23.08% and 38.46%, respectively (P < 0.05). The time of first oral intake was faster in patients after LSD than in those after OSD (1.5 ± 0.7 d vs 3.5 ± 1.6 d, P < 0.05). The hospital stay of patients after LSD was shorter than that of patients after OSD (6.5 ± 2.3 d vs 11.7 ± 4.5 d, P < 0.05). The pain requiring medication was less severe in patients after LSD than in those after OSD (7.69% vs 73.08%, P < 0.001). The overall complication rate was lower in patients after LSD than in those after OSD (19.23% vs 42.31%, P < 0.05). CONCLUSION:Laparoscopic splenectomy and azygoportal disconnection are the feasible, effective, and safe surgical procedure, and are advantageous over minimally invasive surgery for bleeding portal hypertension and hypersplenism.

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In this paper, a simple four-variable first-order shear deformation theory is further applied to solve the bending and free vibration problems of antisymmetrically laminated functionally graded carbon nanotube (FG-CNT)-reinforced composite plates. The adopted four-variable theory contains only four unknowns in its displacement field which is less than the Reddy’s first-order theory. The equations of motion are derived from the Hamilton’s principle with the help of specific boundary conditions. Laminated FG-CNT-reinforced plates with different distribution types of carbon nanotube through the thickness are considered. The material properties of individual layer are estimated by using the extended rule of mixture. Analytical solutions of various simply supported antisymmetric cross-ply and angle-ply laminates are given for case study. The effects of carbon nanotube volume fraction, length to width ratio and thickness to width ratio on the non-dimensional fundamental frequency and the central deflection are investigated for antisymmetrically laminated FG-CNT-reinforced plates.

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A partially debonded piezoelectric actuator in smart composite laminates was modeled using an improved layerwise displacement field and Heaviside unit step functions. The finite element method with four node plate element and the extended Hamilton principle were used to derive the governing equation. The effects of actuator debonding on the smart composite laminate were investigated in both the frequency and time domains. The frequency and transient responses were obtained using the mode superposition method and the Newmark time integration algorithm, respectively. Two partial actuator debonding cases were studied to investigate the debonding effects on the actuation capability of the piezoelectric actuator. The effect of actuator debonding on the natural frequencies was subtler, but severe reductions of the actuation ability were observed in both the frequency and time responses, especially in the edge debonded actuator case. The results provided confirmation that the proposed modeling could be used in virtual experiments of actuator failure in smart composite laminates.

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Boron nitride (BN) nanocrystals with explosion (E) phase were prepared by a novel laser-assisted materials fabrication, i.e., pulsed-laser-induced liquid (acetone)/solid (hexagonal boron nitride bulk) interfacial reaction at normal temperature and pressure. Typical diameters of these synthesized quasi-spherical BN nanocrystals were in the range of 30 to 80 nm. Transmission electron microscopy, x-ray diffraction, and Fourier transformed infrared spectroscopy were used to identify the morphologies and structures of the synthesized nanocrystals. Additionally, we proposed the formation mechanism of cubic-BN and E-BN nanocrystals upon pulsed-laser-induced liquid/solid interfacial reaction, in which both liquid and solid were simultaneously involved.