ABSTRACT
Total volatile organic compounds (TVOCs) are the main indoor pollutants. Long-term exposure to excessive TVOCs will cause acute and chronic adverse health effects. In order to understand current indoor TVOCs pollution in urban residential buildings in China, we searched related literature of indoor TVOCs in urban residential buildings published in CNKI, Wanfang, VIP, Web of Science, and PubMed from 2000 to 2021, and analyzed the pollution characteristics and main sources of indoor TVOCs in urban residential buildings in China. The results showed that the average TVOCs concentration range in urban residential buildings in China was 0.18-1.45 mg·m−3, which was widely distributed and exceeded the relevant national standard. The concentrations of TVOCs in bedrooms, study rooms, and kitchens were relatively high among different rooms. Indoor sources such as decoration materials and human activities after moving in were the main sources of TVOCs, and the concentration of TVOCs decreased the most in 4-6 months after the completion of decoration. However, extending the vacancy time after the completion of decoration is not the best method to effectively remove indoor TVOCs, especially for the areas where indoor air pollutants severely exceeding the national limit, it is necessary to control pollution sources to reduce indoor TVOCs concentration. For the study of indoor air TVOCs, future study directions could be the ratio of indoor and outdoor TVOCs concentration and the analysis of indoor human activities and other pollution sources.
ABSTRACT
Objective To measure the normal sagittal and coronal diameters of thumb and great toe distal phalanx bottom by ultrasonography. Methods One hundred and twenty volunteers' sagittal and coronal diameters of thumb and great toe distal phalanx bottom were measured by ultrasonography. The measurements was analysed by the statistical method. Results The thumb and great toe distal phalanx bottom showed hyperechoic zone,clear boundary with the adjacent fascia and tendon tissue showed low echo area at cross section by high frequency ultrasound. The sagittal diameters of thumb distal phalanx bottom was (8. 07 ± 0. 67)mm in men, while that of great toe distal phalanx bottom was (8. 34 ± 1. 02) mm( t = 1.73, P =0.86).The coronal diameters of thumb distal phalanx bottom was (11.61 ±0.89)mm in men, while that of great toe distal phalanx bottom was (14. 25 ± 0. 84)mm( t = 16. 77, P = 0. 00). The sagittal diameters of thumb distal phalanx bottom was (7. 52 ± 0. 62) mm in women, while that of great toe distal phalanx bottom was (7. 72 ± 0. 67) mm( t = 1. 72, P =0. 14). The coronal diameters of thumb distal phalanx bottom was (10.94 ± 0.97) mm in women, while that of great toe distal phalanx bottom was (13. 51 ±0. 75) mm( t =16.21, P = 0.00). Conclusions The normal sagittal and coronal diameters of thumb and great toe distal phalanx bottom measured by the ultrasonography can guide the operation of wrap-around flap of a great toe with phalanx ungual for thumb II degree defect reconstruction.
ABSTRACT
Objective To evaluate the efficiency of free myocutaneous flap transfer for the treatment of refractory post-traumatic osteomyelitis of the lower leg and foot. Methods Eleven patients with refractory post-traumatic osteomyelitis of the lower legs and feet were treated between February 2004 and December 2007. There were 9 males and 2 females. The average age was 3.5 years. All patients had at least four to five unsuccessful surgical procedures and prolonged antibiotic treatment prior to presentation. The mean duration of osteomyelitis was 26 months (12-47 months). According to the Ciemy-Mader classification, there were 3 cases for ⅢA, 2 for ⅢBL, 4 for ⅥA and 2 for ⅥBL. After radical debridement, free myocutaneous flaps were immediately performed. Nine latissimus dorsi and 2 rectus abdominis myocutaneous flaps were used.External fixation was applied in 6 patients with skeletal instability due to tibial defects. Results An average follow-up was 3.5 years. Two cases suffered partial necrosis and were managed successfully with split-thickness skin grafts later. In 4 patients of presenting segmental bone defect, autogenous bone grafting was applied in one patient and achieved consolidation after 5 months; bone transplantation in 2 patients and achieved consolidation after 8 and 10 months; and vascularized fibula graft in one patient in whom the gap of the tibia was about 10 cm and achieved consolidation after 4 months. The other 7 patients of this group achieved bone consolidation without bone graft. Conclusion The cornerstone of the treatment of chronic osteomyelitis was to be the radical debridement of all involved necrotic and infected soft tissue and bone.The free myocutaneous flaps transfer which has the advantage of obliteration of dead space and stable coverage of the defect was a safe and viable treatment option in chronic osteomyelitis of the lower leg and foot.
ABSTRACT
BACKGROUND: Previous studies has explored the effects of nerve growth factor (NGF) on cultured rabbit Schwann cells as well as preparation of acellular nerve allografts, in addition, the neural complex was prepared in vitro.OBJECTIVE: To investigate the effect of acellular nerve allografts on the functional recovery and reconstruction of the nerve-muscle structure of the sciatic nerve defect in rabbits.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed at the Center Laboratory of Third Hospital of Hebei Medical University from March 2006 to June 2007.MATERIALS: Totally 37 healthy, adult, New Zealand, white rabbits were selected. One rabbit was prepared for extracted nerve bridge, and the others were randomly divided into the experimental and control groups, with 18 animals in each group.METHODS: The double sides of sciatic nerve were removed, divested surrounding tissues, and cut into 3 cm segments, then placed in TdtonX-100 solution for 12 hours, washing with distilled water. The procedure was repeated, and TritonX-100 totally used for 96 hours. Then the extracted nerve bridge was conserved in Hank's solution at temperature of 4 ℃. The concentration of 2~(nd) passage Schwann cell was regulated to 1 ×10~(11)/L, and injected to extracted nerve bridge, followed by DMEM culture, to obtain neural complex. Rabbits in the experimental group were prepared a 20 m defects above knee joints, and the recellularized neural complex were transplanted into the defective sciatic nerve. Rabbits in the control group were prepared by transplanting extracted nerve bridge without Schwann cells.MAIN OUTCOME MEASURES: The elcosis and healing of feet were observed at weeks 4, 8, and 16 after operation, meantime,the recovery of axon of distal end peroneal nerves, myelin sheath, tibialis anterior, as well as motor end plate were detected by electromyogram, light microscope and transmission electron microscope.RESULTS: At weeks 4, 8 and 16 after operation, the rejection was not found in the operating field. The experimental group was better than the control group in healing of ulcers, the number of nerve fibres, the ultramicrostructure of medullary sheaths, the regeneration nerve, the structure of the motor end plate and muscle. At 4 weeks after operation, no nerve conduction was found in 2 groups, but at weeks 8 and 16 after operation, the experimental group was better than the control group in wet weight of tibialis anterior muscle and nerve conduction velocity (P < 0.05).CONCLUSION: The recellularized neural complex can significantly promote the reconstruction of the nerve-muscle structure and functional recovery of injured sciatic nerve.