Numerical study on the influence of the linewidth of a QCW pulsed sodium laser on the brightness of a guide star.

In this paper, we investigated the impact of the linewidth of a QCW pulsed sodium laser on the brightness performance of a generating sodium laser guide star by using the numerical simulation tool PRS. We compared the field test results with the simulation results for two TIPC's 30W class sodium guide star lasers and found the results are in good agreement which proves the tool can be used for prediction. Then, we used the tool to study the influence of D2b repumping and different linewidths from 10MHz to 1GHz on the coupling efficiency and the photon return flux. For the TIPC's QCW pulsed solid-state laser, when the on-sky power density is 1 W/m2, the coupling efficiency is 79.6 (photons/s/W/(atoms/m2)) without D2b repumping, however, the value is up to 213.3 (photons/s/W/(atoms/m2)) with 15% D2b enabled and is increased by 168% than the value without D2b; when the power density reaches 10 W/m2, the coupling efficiencies without D2b and with 15% D2b are 66.6 and 233.6 (photons/s/W/(atoms/m2)), respectively. The results show that for the QCW pulsed laser, D2b repumping is necessary. With D2b enabled, if the spectral linewidth is too wide or too narrow, the photon return flux will be adversely affected. The return flux of 60MHz is 52.5% higher than that of 1GHz, while the return flux of 300MHz is 37.8% higher than that of 10 MHz when the laser power is 100W.

[Application value of Provider-Initiated HIV Testing and Counseling in dermatology].

OBJECTIVE: To explore the clinical application value of Provider-Initiated HIV Testing and Counseling (PITC) by analyzing the positive rate of HIV tests for people in need of PITC and that of routine HIV tests. METHODS: We retrospectively analyzed the demographic and epidemiologic data about the patients seeking PITC services or undergoing routine HIV tests in Nanjing Drum Tower Hospital between January and December 2013. RESULTS: The positive rate of initial HIV screening was 1.98% in the PITC group and 0.24% in the routine test group, while that of confirmed HIV was 0. 40% in the former and 0.07% in the latter, both with statistically significant differences between the two groups (P < 0.01). The positive rate of HIV was markedly higher in males than in females, particularly in the PITC group. CONCLUSION: PITC has a high clinical value in HIV detection for targeted subjects and therefore deserves general application in dermatology.

[The distribution of angiotensin converting enzyme gene I/D polymorphism and its relationship with essential hypertension].

OBJECTIVE: To observe the distribution character of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in Chinese population and its relationship with essential hypertension. METHODS: Polymerase chain reaction (PCR) technique was used to detect the angiotensin converting enzyme gene I/D polymorphism in 2966 subjects of Kailuan Coal Mine, and further restriction analysis was performed. RESULTS: The frequencies of ACE II, ID, DD genotypes in total study population were 41.5%, 38.4%, 20.1%, respectively. The DD genotypes in hypertensive group and that in control group were 18.9% and 21.0%, respectively. There was no significant difference between hypertensive group and control group (P>0.05). The same result was seen after stratification by age and gender in each group, respectively(P>0.05). The DD genotype and D allele showed a tendency to decrease with the increase of age (P<0.001). CONCLUSION: The above results suggested that essential hypertension was not associated with ACE I/D polymorphism. The distributions of ACE genotype and allele varied with age, and the subjects with the character of DD genotype were at higher risk of early death.