Integration of dye-sensitized solar cells, thermoelectric modules and electrical storage loop system to constitute a novel photothermoelectric generator.

This study self-develops a novel type of photothermoelectric power generation modules. Dye-sensitized solar cells (DSSCs) serve as the photoelectric conversion system and a copper (Cu) heat-transfer nanofilm coating on both sides of the thermoelectric generator (TEG) acts as a thermoelectric conversion system. Thus module assembly absorbs light and generates electricity by DSSCs, and also recycles waste heat and generates power by the TEG. In addition, a set of pulsating heat pipes (PHP) filled with Cu nanofluid is placed on the cooling side to increase cooling effects and enhance the power generation efficiency. Results show that when the heat source of thermoelectric modules reaches 90 degrees C, TEG power output is increased by 85.7%. Besides, after thermoelectric modules are heated by additional heat source at 80 degrees C, the electrical energy generated by them can let a NiMH cell (1.25 V) be sufficiently charged in about 30 minutes. When photothermoelectric modules is illumined by simulated light, the temperature difference of two sides of TEG can reach 7 degrees C and the thermoelectric conversion efficiency is 2.17%. Furthermore, the power output of the thermoelectric modules is 11.48 mW/cm2, enhancing 1.4 % compared to merely using DSSCs module.

Comparison of segmental pedicle screw instrumentation versus anterior instrumentation in adolescent idiopathic thoracolumbar and lumbar scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVE: To compare the results of anterior instrumentation versus segmental pedicle screw instrumentation in adolescent idiopathic thoracolumbar and lumbar scoliosis. SUMMARY OF BACKGROUND DATA: Anterior instrumentation is an established method of correcting adolescent idiopathic thoracolumbar and lumbar scoliosis. Posterior segmental pedicle screw instrumentation, with its more powerful corrective force over hooks, could offer significant advantages. METHODS: A retrospective analysis was conducted on 36 consecutive female patients with adolescent idiopathic thoracolumbar and lumbar scoliosis who had surgery from December 1997. All had a minimum of 2-year follow-up. Eleven patients had posterior surgery. RESULTS: Mean age at surgery was similar between both groups. Length of surgery was significantly shorter in the posterior group (189 minutes vs. 272 minutes). Length of hospital stay was shorter in the posterior group (6.2 days vs. 8 days). Estimated blood loss, duration of analgesia, and ICU stay did not differ significantly between the 2 groups. No complications were encountered in both groups at the latest follow-up. The magnitudes and flexibility of the thoracolumbar/lumbar curves did not differ significantly between the 2 groups. The number of levels in the major curve was also similar between the groups. Fusion levels were shorter in the anterior group (mean, 4.1 vs. 5.0). The percentage correction of scoliosis was similar between the 2 groups at all stages of follow-up, being 74% at 1 week postsurgery, 70% at 6 months postsurgery, 68% at 1 year postsurgery and latest follow-up for the anterior group, and 71% at 1 week postsurgery, 67% at 6 months postsurgery, 68% at 1 year postsurgery, and 67% at the latest follow-up for the posterior group. Thoracolumbar sagittal alignment at T11-L2 was maintained for both groups throughout the follow-up period. The incidence of proximal junctional kyphosis was higher in the posterior group (P < 0.01). CONCLUSION: Surgical correction of both the frontal and sagittal plane deformity are comparable to anterior instrumentation. Shorter lengths of surgery and hospital stay are the potential benefits of posterior surgery. Posterior segmental pedicle screw instrumentation offer significant advantages and is a viable alternative to standard anterior instrumentation in idiopathic thoracolumbar and lumbar scoliosis.

Recruitment of voluntary non-remunerated apheresis donors: the second five years' experience in Shenzhen.

The voluntary non-remunerated blood donation campaign in Shenzhen, China, was launched in 1993 and the smooth change from paid donors to unpaid took only a decade. In the first half the volunteer donation system and a sufficient blood supply was promoted and this paved the way for further development in the second half during which the non-remunerated donation system became substantial and integral due to recruitment for plateletapheresis and peripheral stem cells donation as well as whole blood donations. Ninety percent of the donors registered for plateletapheresis do donate and none of the twenty-three non-related donors with matched HLA genotypes broke their promise to donate their peripheral stem cells.