Reconstruction of complex chest wall defects:A case report

BACKGROUND Chronic radiative chest wall ulcers are common in patients undergoing radiation therapy.If not treated early,then symptoms such as erosion,bleeding and infection will appear on the skin.In severe cases,ulcers invade the ribs and pleura,presenting a mortality risk.Small ulcers can be repaired with pedicle flaps.Because radioactive ulcers often invade the thorax,surgeons need to remove large areas of skin and muscle,and sometimes ribs.Repairing large chest wall defects are a challenge for surgeons.CASE SUMMARY A 74-year-old female patient was admitted to our department with chest wall skin ulceration after radiation therapy for left breast cancer.The patient was diagnosed with chronic radioactive ulceration.After multidisciplinary discussion,the authors performed expansive resection of the chest wall ulcers and repaired large chest wall defects using a deep inferior epigastric perforator(DIEP)flap combined with a high-density polyethylene(HDPE)patch.The patient was followed-up 6 mo after the operation.No pigmentation or edema was found in the flap.CONCLUSION DIEP flap plus HDPE patch is one of the better treatments for radiation-induced chest wall ulcers.

Durable flame-retardant,smoke-suppressant,and thermal-insulating biomass polyurethane foam enabled by a green bio-based system

Bio-based polyurethane foam has attracted increasing attentions due to eco-friendliness and fossil feedstock issues.However,the inherent flammability limits its application in different fields.Herein,we demonstrate a green bio-based flame-retardant system to fabricate polyurethane foam composite with durable flame retardancy,smoke suppression,and thermal insulation property.In this system,the green bio-based polyol(VED)with good reactivity and compatibility plays a role of flame retardant and EG acts as a synergistic filler.As a result,the LOI value of foam composite increased to 30.5 vol.%and it achieved a V-0 rating in the UL-94 vertical burning test.Additionally,the peak heat release rate(pHRR)and the total smoke production(TSP)decreased by 66.1%and 63.4%,respectively.Furthermore,the foam composite maintained durable flame retardancy after accelerated thermal aging test,whose thermal-insulating property was maintained even after being treated in high-humidity environment with 85%R.H.for a week.This work provides a facile strategy for durable flame retardancy and long-term thermal insulation performance,and creates opportunities for the practical applications of bio-based foam composites.

An Efficient Halogen-free Flame Retardant for Polyethylene：Piperazine-modified Ammonium Polyphosphates with Different Structures

In this study, piperazine-modified ammonium polyphosphates（PA-APPs） with hierarchical structure were synthesized through ion exchange reaction. ^1H nuclear magnetic resonance（^1H-NMR）, Fourier transform infrared spectra（FTIR）, elemental analysis（EA）, and inductively coupled plasma atomic emission spectroscopy（ICP-AES） confirmed that the PA-APPs with different structures were prepared successfully. Then these flame retardants were used alone as monocomponent intumescent flame retardant for low-density polyethylene（LDPE）. Combustion tests demonstrated that the flameretardant efficiency of PA-APP containing about 7 wt% carbon（PA-APP_7） was significantly higher than that of the other PAAPPs with more or less carbon. The flame-retarded LDPE system with 30 wt% PA-APP_7 passed the UL-94 V-0 rating, and had the oxygen index（LOI） of 33.0%. Thermal analysis illustrated that the thermal decomposition behavior of PA-APP changed with incorporating different contents of PA. For all these PA-APPs, PA-APP_7 showed higher thermal stability than the other PA-APP flame retardants. All the experimental results proved that PA-APP_7 could reach the balance of an acid source, a blowing source, and a charring source as a mono-component intumescent flame retardant for LDPE. Further, it led to the formation of a compact intumescent char layer containing the structures of rich P―O―P, P―N―C, C=C, etc. during burning which in turn resulted in the excellent flame-retardant efficiency of PA-APP7.