Objective To evaluate the effects of indoor temperature and relative humidity on acute exacerbations of chronic obstructive pulmonary disease（AECOPD）.Methods A total of 70 moderate to very severe COPD patients were recruited.The data including indoor temperature and relative humidity twice daily，increase over their stable symptoms in "major" symptoms（dyspnea，sputum purulence，sputum amount） and "minor" symptoms（nasal discharge/congestion，sore throat，cough），and adjustment of medication were recorded on diary cards.All data were collected from Jan 2005 to Dec 2005 by telephone inquiring or home visiting.Furthermore，the corresponding median outdoor temperature，relative humidity and air pressure from atmosphere bureau were compared with indoors parameters to examine the different effects on AECOPD.Results Fifty-five cases completed the whole investigation.Indoor temperature and relative humidity were both risk factors when logistic regression was used to evaluate the effect.Our research showed that AECOPD was significantly related to indoor and ourdoor environment factors.The correlation coefficient of all factors were r=－0.686（indoor temperature），r=－0.671（outer temperature），r=0.105（indoor humidity），r=－0.115（outer humidity），r=0.545（atmospheric pressure） respectively.Conclusions The indoor temperature and relative humidity，especially low temperature and high relative humidity，had important effects on AECOPD of moderate to very severe patients.It may be helpful to prevent AECOPD by adjusting the indoor temperature and relative humidity.
Objective To study the responsiveness change of neutrophils when experiencing the second insult after the initial temperature activation in cardiopulmonary bypass (CPB) by using an in vitro model. Methods The neutrophils were isolated from blood which was drawn from each of 60 health volunteers. The samples were divided into 5 groups including normothermia, tepid temperature, moderate hypothermia, deep hypothermia, and rewarming hyperthermia by random digital table with 12 in each group according to the change of temperature during CPB. An in vitro model for studying neutrophil responsiveness was established by using a polymerase chain reaction thermocycler. Five time points were set for each group, including T0: starting CPB, T1: starting rewarming, T2: 0.5 h after rewarming, T3: 1 h after rewarming, and T4: 1.5 h after rewarming. Platelet activating factor (PAF) was added into each group at T2, T3, and T4, and then the value of membranebound elastase (MBE) activity was measured as responsiveness of neutrophils. Analysis of covariance was applied by using SPSS 13.0 for statistic analysis. If the [CM(159mm]covariance had significant difference between main effects, Bonferroni method would be applied for pairwise comparison. Results The main effect difference of neutrophil responsiveness among different groups was statistically different (F=4.372,P=0.002). MBE value had no statistical difference between the normothermia and tepid temperature groups (81.9±4.5 ng/10.6 cells vs. 76.5±3.6 ng/106 cells, P=0.134). while the MBE values in these two groups were higher than those in the other three groups (P=0.001). MBE value in the rewarming hyperthermia group was higher than that in the deep hypothermia group (61.2±2.7 ng/106 cells vs. 50.9±3.7 ng/106 cells, P=0.005). There was no statistical difference between the moderate hypothermia group (56.4±3.2 ng/106 cells) and the rewarming hyperthermia group (P=0.167), so was it between the moderate hypothermia group and the deep hypothermia group (P=0.107). The main effects of neutrophil responsiveness at different time points was statistically different (F=3.566, P=0.03) when PAF was added. MBE value at T4 was higher thanthat at T2 (70.9±2.5 ng/106 cells vs. 59.9±2.3 ng/106 cells, P=0.027). There was no statistical difference among T3 (65.5±1.8 ng/106 cells), T2 (P=0.168), and T4 (P=0.292) in MBE value. Conclusion Normothermia， tepid temperature， and rewarming hyperthermia during CPB can enhance neutrophil responsiveness and MBE release when neutrophils suffer the second insult. There is a time window for neutrophils to be easily activated during rewarming period.
ObjectiveTo review the progress of cell sheet technology (CST) and its application in bone tissue engineering. MethodsThe literature concerning CST and its application was extensively reviewed and analyzed. ResultsCST using temperature-responsive culture dishes is applied to avoid the shortcomings of traditional tissue engineering. All cultured cells are harvested as intact sheets along with their deposited extracellular matrix. Avoiding the use of proteolytic enzymes, cell sheet composed of the cells and extracellular matrix derived from the cells, and remained the relative protein and biological activity factors. Consequently, cell sheet can provide a suitable microenvironment for the bone regeneration in vivo. With CST, cell sheet engineering is allowed for tissue regeneration by the creation of three-dimensional structures via the layering of individual cell sheets, be created by wrapping scaffold with cell sheets, or be created by folding the cell sheets, showing great potential in tissue engineered bone. ConclusionConstructing tissue engineered bone using CST and traditional method of bone tissue engineering will promote the development of the bone tissue engineering.
Currently, transcranial magnetic stimulation (TMS) has been widely used in the treatment of depression, Parkinson’s disease and other neurological diseases. To be able to monitor the brain’s internal activity during TMS in real time and achieve better treatment outcomes, the researchers proposed combining TMS with neuroimaging methods such as magnetic resonance imaging (MRI), both of which use Tesla-level magnetic fields. However, the combination of strong current, large magnetic field and small size is likely to bring physical concerns which can lead to mechanical and thermal instability. In this paper, the MRI static magnetic field, the TMS coil and human head model were built according to the actual situations. Through the coupling of the magnetic field and the heat transfer module in the finite element simulation software COMSOL, the force and temperature of the TMS coil and head were obtained when the TMS was used in combination with MRI (TMS-MRI technology). The results showed that in a 3 T MRI environment, the maximum force density on the coil could reach 2.51 × 109 N/m3. Both the direction of the external magnetic field and the current direction in the coil affected the force distributions. The closer to the boundary of the external magnetic field, the greater the force. The magnetic field generated by the coil during TMS treatment increased the temperature of the brain tissue by about 0.16 °C, and the presence of the MRI static magnetic field did not cause additional thermal effects. The results of this paper can provide a reference for the development of the use guidelines and safety guidelines of TMS-MRI technology.
To solve the problems of small one-time ablation range and easy charring of the tissue around the electrode associated with the tumor radiofrequency ablation needle, based on the multiphysical field coupling analysis software COMSOL, the effects of needle material, the number of sub needles and the bending angle of sub needles on the ablation effect of radiofrequency ablation electrode needle were studied. The results show that compared with titanium alloy and stainless steel, nickel titanium alloy has better radiofrequency energy transmission efficiency and it is the best material for electrode needle. The number of sub needles has a great influence on the average necrosis depth and the maximum necrosis diameter. Under the same conditions, the more the number of sub needles, the larger the volume of coagulation necrosis area. The bending angle of the needle has a great effect on the maximum diameter of the coagulated necrotic area, but has little effect on the average necrotic depth. Under the same other conditions, the coagulation necrosis area formed by ablation increased with the increase of the bending angle of the sub needle. For the three needles with bending angles of 60 °, 90 ° and 120 ° analyzed in this paper, the one with bending angle of 120 ° can obtain the largest coagulation necrosis area. In general, the design of nickel titanium alloy with 120 ° bending 8-pin is the optimal. The average depth of radiofrequency ablation necrosis area is 32.40 mm, and the maximum necrosis diameter is 52.65 mm. The above optimized design parameters can provide guidance for the structure and material design of tumor radiofrequency ablation needle.