Hepatitis C Virus Subtype and Evolution Characteristic Among Drug Users, Men Who Have Sex With Men, and the General Population in Beijing, China.

The aim of this study was to characterize the current molecular epidemiology of hepatitis C virus (HCV) infection and evaluate the evolutionary patterns of HCV subtypes in Beijing, China, among different subpopulations.The whole blood samples and behavioral data were collected from a total of 10,354 subjects, including drug users (DUs), men who have sex with men (MSM), and the general population, in Beijing from 2010 to 2011. Samples were tested for HCV infection using both enzyme-linked immunosorbent assay (ELISA) and real-time PCR. All viremic subjects were then sequenced by nested PCR over core/E1 and NS5B regions. Phylogenetic and phylogeographic analysis was performed by BEAST software.In total, 217 subjects (2.1%) were tested positive for HCV by antibody or vRNA-based testing. HCV prevalence rates for DUs, MSM, and the general population were 26.2%, 0.54%, and 0.37%, respectively. The 156 HCV RNA-positive samples were sequenced. Nine HCV genotypes, including 1a, 1b, 2a, 3a, 3b, 6a, 6n, 6u and 6v, were detected. The most prevalent subtypes were 3b (36.09%), 1b (32.54%), and 3a (16.57%). Bayesian evolutionary analysis estimated that the time of introduction of subtype 1b into Beijing was 2004 (95% CI: 1997.7, 2007.7), with subtypes 3a and 3b being introduced later in 2006. Evolutionary analyses further suggested that subtype 1b from Beijing and Shanghai were closely related, whereas subtype 3a sequences were more similar with sequences from Yunnan, Guangzhou, Hong Kong, and Jiangsu. Subtype 3b sequences were closely related to those from Yunnan, Guangdong, and Hong Kong.Thus, the current HCV epidemic in Beijing is complex, heavily affecting DUs, and involving multiple genotypes that likely spread from different regions in China with its large migrant population.

High-accuracy self-mixing interferometer based on single high-order orthogonally polarized feedback effects.

A simple and high-accuracy self-mixing interferometer based on single high-order orthogonally polarized feedback effects is presented. The single high-order feedback effect is realized when dual-frequency laser reflects numerous times in a Fabry-Perot cavity and then goes back to the laser resonator along the same route. In this case, two orthogonally polarized feedback fringes with nanoscale resolution are obtained. This self-mixing interferometer has the advantages of higher sensitivity to weak signal than that of conventional interferometer. In addition, two orthogonally polarized fringes are useful for discriminating the moving direction of measured object. The experiment of measuring 2.5nm step is conducted, which shows a great potential in nanometrology.

HIV-1 transmitted drug resistance-associated mutations and mutation co-variation in HIV-1 treatment-naïve MSM from 2011 to 2013 in Beijing, China.

BACKGROUND: Transmitted drug resistance (TDR) is an important public health issue, because TDR-associated mutation may affect the outcome of antiretroviral treatment potentially or directly. Men who have sex with men (MSM) constitute a major risk group for HIV transmission. However, current reports are scarce on HIV TDR-associated mutations and their co-variation among MSM. METHODS: Blood samples from 262 newly diagnosed HIV-positive, antiretroviral therapy (ART)-naïve MSM, were collected from January 2011 and December 2013 in Beijing. The polymerase viral genes were sequenced to explore TDR-associated mutations and mutation co-variation. RESULTS: A total of 223 samples were sequenced and analyzed. Among them, HIV-1 CRF01_AE are accounted for 60.5%, followed by CRF07_BC (27.8%), subtype B (9.9%), and others. Fifty-seven samples had at least one TDR-associated mutation, mainly including L10I/V (6.3%), A71L/T/V (6.3%), V179D/E (5.4%), and V106I (2.7%), with different distributions of TDR-associated mutations by different HIV-1 subtypes and by each year. Moreover, eight significant co-variation pairs were found between TDR-associated mutations (V179D/E) and seven overlapping polymorphisms in subtype CRF01_AE. CONCLUSIONS: To date, this work consists the most comprehensive genetic characterization of HIV-1 TDR-associated mutations prevalent among MSM. It provides important information for understanding TDR and viral evolution among Chinese MSM, a population currently at particularly high risk of HIV transmission.

Controlling the duty cycle of the eigenstates in laser with multiple optical feedback.

The polarization dynamics of a quasi-isotropic single-mode laser subjected to multiple optical feedback is presented. The variable duty cycle of two eigenstates is observed in high-frequency optical fringes. The high-frequency optical fringes are induced by the multiple reflections in the asymmetry feedback cavity. The duty cycle of two eigenstates can be controlled easily by adjusting the position of polarization flipping due to the residual stress of laser mirror. Particularly, when the frequency difference results from residual stress is reduced to 1.5MHz, the position of polarization flipping moves to the edge of each fringe which can be used to measure small displacement with direction sensitivity and high resolution.

Polarization characteristics of He-Ne laser with different directions of polarized feedback.

A polarizer is placed in an external feedback cavity to form polarized optical feedback. The effect of the different directions of polarized optical feedback on laser polarization characteristics (LPCs) is investigated experimentally and theoretically. The angle between the optical axis of the polarizer and the laser polarization is changed from 0° to 90°. It is found that LPCs vary greatly under different directions of polarized optical feedback. The angle range can be divided into five zones (two flipping zones, ⊥-polarization zone, bistable zone, and ∥-polarization zone) according to the different LPCs. When the angle is in the range of the ⊥-polarization zone (∥-polarization zone), the laser outputs ⊥-polarization (∥-polarization). Thus, one can choose either ⊥-polarization or ∥-polarization by properly aligning the axis of the polarizer.

Note: High-performance HeNe laser feedback interferometer with birefringence feedback cavity scanned by piezoelectric transducer.

We demonstrate a high-performance HeNe laser feedback interferometer (HLFI) based on a birefringence feedback cavity scanned by a piezoelectric transducer (PZT). The PZT scanning technique leads to a significant improvement in the HLFI's anti-jamming capability. The null drift under general laboratory conditions is approximately ±32 nm, corresponding to ±2 pulses. The phase difference between the two measurement signals does not vary when the feedback cavity length changes. This ensures a large measurement range for the HLFI. The HLFI presented here features a large measurement range (>1 m), nanometer-scale resolution (15.82 nm), a compact configuration, and low cost.

Laser feedback interferometry based on high density cosine-like intensity fringes with phase quasi-quadrature.

A novel laser feedback interferometry based on high-order feedback is presented and realized for the first time. The interferometer uses a birefringence dual frequency laser and a tilted feedback mirror with high amplitude reflectivity to generate high density cosine-like optical fringes. These optical fringes have nanoscale resolution. Particularly, phase quasi-quadrature between the dual frequency fringes is obtained because of the phase shift caused by the changes of external optical path length. This phase characteristic can be used to distinguish the direction of movement easily. Under typical room conditions, the system's resolution is 0.51nm in 850µm range, and its 2 min displacement accuracy is 5nm.

The frequency stabilization method of laser feedback interferometer based on external cavity modulation.

Laser frequency stabilization is one of the foremost factors that influence the accuracy of measurement using a laser feedback interferometer, especially when the system is in the presence of strong optical feedback. In this paper, we use external cavity modulation to demonstrate a simple and effective method of frequency stabilization for laser feedback interferometer with strong optical feedback. The external cavity modulation is realized by oscillating a feedback mirror driven by a piezoelectric ceramic, the stable feedback optical field is obtained that has strong performance of anti-disturbance. Meanwhile, we stabilize the laser frequency by the thermal frequency-stabilizing. These lead to the realization of stable laser feedback interferometer. The relative uncertainty of the frequency stabilization is less than 1 part in 10(7).

High density fringes and phase behavior in birefringence dual frequency laser with multiple feedback.

The high density intensity fringes and phase behavior in birefringent dual frequency laser with multiple feedback are studied for the first time. It was discovered that the fringes of output intensity are made of bipolar pulses with symmetric external cavity feedback and the fringe density is as high as compared to the conventional feedback. The high density cosine-like fringes are obtained with asymmetric external cavity feedback by adjusting the tilt angle of the feedback mirror and the fringe density is about 22 times higher compared to the conventional feedback. Moreover, there is a phase difference between the two cosine-like fringes and the phase difference is varied with the change of the external cavity length. The experimental results and a theoretical analysis are presented in this work. These results offer a large increase in the resolution for the optical feedback interferometer with the birefringence dual frequency laser.

[Effects and mechanism of drug serum of prepared radix polygoni multiflori on rat osteoblast in vitro].

OBJECTIVE: To study the effect of drug serum of prepared Radix Polygoni Multiflori on rat osteoblast (Ob) and its mechanism. METHODS: The animal serum was prepared by serum pharmacology means. The cells were getting by separating and inducing the SD neonatal rat skull bone. The proliferation and differentiation of Ob were detected by CCK-8, alkaline phosphatase (ALP) activity analysis. And RT-PCR method was used to determine the osteogenesis-related genes expression. RESULTS: Compared with control group, the groups with drug serum of prepared Radix Polygoni Mutiflori, 10%, 20% and 30% had an effect on promotion the proliferation significantly on Ob (P < 0.01). There was no concentration-related manner among groups. The 5% and 10% drug serum decreased ALP activity at the post-translation phase compared with control group, but higher doses (20% and 30%) did not have the same effect. However, drug serum of PR/MIN increased significantly osteogenesis-related genes (OC, ALP, Cbfalpha1) mRNA expression (P < 0.05). CONCLUSION: The drug serum of prepared Radix Polygoni Multiflori can stimulate osteoblast proliferation in vitro, and its mechanism may be associated with increasing osteogenesis-related genes expression.

[Study on extraction process for the icariin of hugu capsule with ultrasonic technology].

OBJECTIVE: To study the best ultrasonic technology of the extraction of icariin of Hugu capsule. METHODS: Used the content of icariin as index, orthogonal experiment was carried out to investigate 4 influential factors as follows: the ultrasonic power (A), the ultrasonic frequency (B), the material fluid ratio (C), the time (D). RESULTS: The best extraction conditions were as follows: the ultrasonic power was 120 W, the ultrasonic frequency was 28 KHz, solid-liquid ratio of 1 : 35, the extraction time was 10 min. CONCLUSION: Optimization of extracting process is simple, quick and low energy consumption. Under these conditions, the extraction of icariin is 1.8 times higher than that of the traditional extraction method.

[Observation on two kinds of recombinant hepatitis B vaccines used in populations with different immunity].

OBJECTIVE: To evaluate the immunity status on different hepatitis B vaccines currently being used in Beijing. METHODS: College students who had not received hepatitis B vaccine and children who had received whole-course immunization at birth, were tested HBsAg, anti-HBs and anti-HBc. All the test-negative cases were served as research subjects. 3 doses recombinant hepatitis B vaccines were given to the college students, following the 0, 1, 6 months schedule. Among which, 140 cases received recombinant beer yeast hepatitis B vaccine (BY vaccine, 10 microg, 5 microg, 5 microg), and 140 cases with recombinant hansenula polymorpha hepatitis B vaccine (HP vaccine, 10 microg, 10 microg, 10 microg). 1 dose was given for boosting immunization to 98 children, in which 49 cases with BY vaccine (5 microg) and 49 cases with HP vaccine (10 microg). Anti-HBs was tested 1 month after. RESULTS: The total positive (> or = 10 mIU/ ml) rate was lower among BY vaccine group than HP vaccine group for the college students (93.5 %, 99.3% , P<0.05), but no statistical difference on GMT(81.2 mIU/ml, 94.6 mIU/ml, P>0.05) was found. For males, the positive rate and GMT were lower in BY vaccine group than in HP vaccine group (85.7% ,100.0%, P<0.01)(56.6 mIU/ml, 98.6 mIU/ml, P<0.01), but with no statistical difference for females (98.8%, 98.5%, P> 0.05) (103.4 mIU/ml, 90.3 mlU/ml, P> 0.05). For the same vaccine, the positive rate and GMT were lower in males than in females when using BY vaccine (85.7% , 98.8%, P<0.01)(56.6 mIU/ml,103.4 mIU/ml, P< 0.01), but no statistical difference was found on HP vaccine(100.0%, 98.5%, P>0.05)(98.6 mIU/ml, 90.3 mIU/ml, P>0.05). The positive rate of anti-HBs was decreasing along with age among the children who had received a whole-course immunization at birth (P <0.01). 98.6 % of the 70 negative cases appeared positive conversion after receiving 1 dose and the GMT raised significantly by 15 times. No statistical difference was found between the two kinds of vaccines(100.0%, 97.4%, P>0.05)(80.5 mIU/ml, 68.5 mIU/ml, P>0.05). CONCLUSIONS: The type of vaccine and sex were related to the effects, better with HP vaccine than BY vaccine in males but was the same for females in adults receiving basic immunization according to the conventional doses. Both kinds of vaccines were ideal when children receiving boosting immunization. The immune memory was good for persons who had received primary immunization with recombinant vaccine but antibody appeared negative conversion. It was not necessary to boost immunization within 6 years after a whole-course immunization with recombinant hepatitis B vaccine in infancy.