Objective To evaluate the effect of Chinese gentian extracts on the proliferation of,apoptosis and phosphorylation of epidermal growth factor receptor (EGFR) in HaCaT cells induced by epidermal growth factor (EGF).Methods Methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate the proliferation of HaCaT cells pretreated with EGF of 20 μg/L for 24 hours followed by 24 hours of treatment with various concentrations of Chinese gentian extracts.Flow cytometry was carried out to detect apoptosis in HaCaT cells pretreated with EGF of 20 μg/L for 24 hours followed by 4 hours of treatment with different concentrations of Chinese gentian extracts.Western blot was conducted to measure the level of phosphorylated EGFR in HaCaT cells treated with different concentrations of Chinese gentian extracts for 24 hours followed by treatment with EGF of 20 μg/L for 10 minutes.Results Chinese gentian extracts inhibited the proliferation (r =-0.991,P ＜ 0.01),but promoted the apoptosis (r =0.996,P ＜ 0.05) of HaCaT cells induced by EGF in a dose-dependent manner.At the same time,the extracts suppressed the phosphorylation of EGFR in HaCaT cells induced by EGF,and the suppressing effect increased with the rise in the concentration of the extracts.Conclusions Chinese gentian may inhibit the proliferation,but promote the apoptosis of keratinocytes by decreasing EGFR phosphorylation and blocking relevant intracellular signaling pathways.

Objective To explore the influencing factors of job burnout among nurses in level 2 and level 3 hospitals in Guangdong province. Methods A total of 2 066 first line nurses from 133 medical, surgical and intensive care units (ICU) of 23 level 2 and level 3 hospitals in Guangdong province were surveyed employing the questionnaire Hospital Nursing Human Resources Research during December 2013 to August 2014. Results In the multivariate logistic regression models, each additional doctor per nurse was associated with 1.34 times increase in the likelihood of high level of emotional exhaustion(EE). Nurses had a 57.4%higher risk of high level of EE when they worked overtime. Every one point increase in ancillary service score, and every one more year working as a nurse was associated with 5.4%, 2.3%increase in the likelihood of high level of EE, respectively. Nurses were 42.1%,40.9%more likely to exhibit high level of depersonalization(DP) when they worked in medical units or hospitals of level 3, compared with nurses of surgical units and hospitals of level 2. Nurses had a 29.5%higher risk of high level of DP when they worked overtime. Nurses holding higher positions had a lower likelihood(37.7%) of high level of reduced personal accomplishment(PA) compared with nurses holding lower positions. Nurses in medical units or ICUs had a 31.2%, 51.6%higher risk of high level of PA than nurses in surgical units, respectively. Conclusions Job burnout of nurses is at a quite high level in level 2 and level 3 hospitals in Guangdong province. The probability of the occurrence of burnout is related to the hospital, unit and nurse characteristics and nursing workloads.

In order to improve the resolution, contrast and frame rate of ultrasound imaging, it is necessary to design an adaptive beamforming method for plane wave ultrasound imaging. An optimized minimum variance algorithm that suits plane wave ultrasound imaging was proposed, based on the traditional minimum variance algorithm that combines with the subband beamforming as well as the forward-backward spatial smoothing method in the frequency domain. To verify the effectiveness of the improved algorithm, the matlab software was used. Simulation results showed that full width at half maximum and peak side-lobe level of Optimized MV, Conventional MV, DAS boxcar, and Linear scan methods were 0.08, 0.36, 0.92, 1.42 dB, and -41.1, - 37.3, -16.9, - 34.1 dB, respectively. The improved algorithm can significantly improve the image resolution and contrast, particularly applicable to plane wave ultrasound imaging, compared with the conventional minimum variance algorithm and traditional delay-and-sum method.
Algorithms ; Contrast Media ; Image Enhancement ; Image Processing, Computer-Assisted ; methods ; Microbubbles ; Phantoms, Imaging ; Ultrasonography ; instrumentation ; methods