Our field investigation indicates that the northern piedmont fault of the Hengshan Mountain has dislocated proluvial fan and terrace I of the gully mouth on the northern border of the Hengshan Mountain. Stratigraphic ...Our field investigation indicates that the northern piedmont fault of the Hengshan Mountain has dislocated proluvial fan and terrace I of the gully mouth on the northern border of the Hengshan Mountain. Stratigraphic age data indicates that the surface layer in the middle and rear part of the proluvial fan and on the terrace I of the gully mouth on the mountain border consists of sediments of about 5200～6800a B.P. The Hezhuang and Niucaoyu trenches excavated in the front of Hengshan Mountain revealed that 3 paleoseismic events have occurred along the northern piedmont fault of Hengshan Mountain since the early Holocene. The 3 paleoseismic events occurred in 2260±190～4370±150a BP, nearly 5628±150a BP, and 8083±250～8430±720a BP, respectively, and their recurrence interval is 2313a,2628a and 2471a on average. The coseismic vertical displacement produced by these events is 1 0～3 0m. The elapsed time of the latest movement along the fault has exceeded the recurrence interval of these paleoearthquakes. Thus, there exists the possibility of strong earthquake occurrence along the fault from now onward, so the fault is in need of observation.展开更多
Laser lipolysis can effectively treat obesity and its associated diseases, such as hypertension, fatty liver, and hyperlipidemia. However, currently available invasive laser lipolysis, which transmits laser to a fiber...Laser lipolysis can effectively treat obesity and its associated diseases, such as hypertension, fatty liver, and hyperlipidemia. However, currently available invasive laser lipolysis, which transmits laser to a fiber-optic catheter inserted into the subcutaneous tissue for irradiation through an incision, may cause hematomas, infections, and empyrosis. The current study presents a novel, noninvasive approach for laser lipolysis, which directly irradiates the intact skin surface without an incision and preferentially targets adipose tissue at the near-infrared band. High laser energy is necessary to damage adipocytes; however, this may carbonate and burn the dermis. Therefore, the introduction of skin cooling is essential to avoid unwanted hyperthermal injury and improve the threshold of radiant exposure. In the current study, we investigated a novel noninvasive approach assisted with skin cooling by establishing a homogeneous multi-layer skin model. In this method, light propagation in the skin was simulated by using the Monte Carlo method. Skin cooling was employed before laser irradiation to protect the epidermis from thermal damage, which was treated as a boundary condition based on Newton's law. The numerical results showed that the photons were deposited in the adipose layer more than in the other layers. Laser can effectively destroy adipose tissue at an energy density of >200 J/cm^2 at 1210 nm wavelength, whereas at least 300 J/cm^2 is required at 1064 nm to achieve the same effect. In this experiment, at >5 s pulse width, the selectivity of adipose was not obvious. Moreover, the results indicated that 60 ms R134a or R404a spray can effectively reduce the temperature of the epidermis. R404a exhibited a stronger cooling effect than R134a. Cold air cooling at -10 °C for 10 s could effectively decrease the skin temperature, and deeper cooling could be achieved by cold air cooling compared with cryogen spray cooling.展开更多
文摘Our field investigation indicates that the northern piedmont fault of the Hengshan Mountain has dislocated proluvial fan and terrace I of the gully mouth on the northern border of the Hengshan Mountain. Stratigraphic age data indicates that the surface layer in the middle and rear part of the proluvial fan and on the terrace I of the gully mouth on the mountain border consists of sediments of about 5200～6800a B.P. The Hezhuang and Niucaoyu trenches excavated in the front of Hengshan Mountain revealed that 3 paleoseismic events have occurred along the northern piedmont fault of Hengshan Mountain since the early Holocene. The 3 paleoseismic events occurred in 2260±190～4370±150a BP, nearly 5628±150a BP, and 8083±250～8430±720a BP, respectively, and their recurrence interval is 2313a,2628a and 2471a on average. The coseismic vertical displacement produced by these events is 1 0～3 0m. The elapsed time of the latest movement along the fault has exceeded the recurrence interval of these paleoearthquakes. Thus, there exists the possibility of strong earthquake occurrence along the fault from now onward, so the fault is in need of observation.
基金financially supported by the National Natural Science Foundation of China (Grant No.51336006 and 51727811)
文摘Laser lipolysis can effectively treat obesity and its associated diseases, such as hypertension, fatty liver, and hyperlipidemia. However, currently available invasive laser lipolysis, which transmits laser to a fiber-optic catheter inserted into the subcutaneous tissue for irradiation through an incision, may cause hematomas, infections, and empyrosis. The current study presents a novel, noninvasive approach for laser lipolysis, which directly irradiates the intact skin surface without an incision and preferentially targets adipose tissue at the near-infrared band. High laser energy is necessary to damage adipocytes; however, this may carbonate and burn the dermis. Therefore, the introduction of skin cooling is essential to avoid unwanted hyperthermal injury and improve the threshold of radiant exposure. In the current study, we investigated a novel noninvasive approach assisted with skin cooling by establishing a homogeneous multi-layer skin model. In this method, light propagation in the skin was simulated by using the Monte Carlo method. Skin cooling was employed before laser irradiation to protect the epidermis from thermal damage, which was treated as a boundary condition based on Newton's law. The numerical results showed that the photons were deposited in the adipose layer more than in the other layers. Laser can effectively destroy adipose tissue at an energy density of >200 J/cm^2 at 1210 nm wavelength, whereas at least 300 J/cm^2 is required at 1064 nm to achieve the same effect. In this experiment, at >5 s pulse width, the selectivity of adipose was not obvious. Moreover, the results indicated that 60 ms R134a or R404a spray can effectively reduce the temperature of the epidermis. R404a exhibited a stronger cooling effect than R134a. Cold air cooling at -10 °C for 10 s could effectively decrease the skin temperature, and deeper cooling could be achieved by cold air cooling compared with cryogen spray cooling.
