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In this paper, we presented the results from three related analysis performed by adopting the failure models, which provided an explanation of performance influencing factors caused by different number of contact cores, for the purpose of measuring the temperature change and deformation value, which were the factors causing contact failure. The failures were localized in contact parts of the connectors. Performed investigations included thermal analysis, modal analysis, harmonic response analysis and contact failure analysis. From the results of these simulations, related temperature and vibration analysis nephograms were got respectively. And the correctness of results of thermal analysis was verified by Fourier law. The research results of this paper provide a reference for thermal analysis and vibration analysis of electrical connectors, which is important for ensuring the reliability and safety of electrical connectors.

Acid rain is a serious environmental problem and has obvious impacts on the growth, reproduction, and photosynthesis of terrestrial plants. Ulva prolifera, a main blooming species of green tides, was studied on its physiological response to acid rain. The photosynthetic parameters were determined under different conditions (salinity: 1, 10, 30‰; pH: 3.0, 3.5, 4.5; duration: 0.5, 1.0, 2.0 h) followed by 24-h recovering under natural conditions. Results showed 1-h treatment with pH 3.5 caused 50-70% reduction in the maximal quantum yield of PSII photochemistry (Fv/Fm) and effective quantum yield of PSII photochemistry (ФPSII) at normal salinity but when the low pH was combined with a salinity of 10‰ or lower, PSII activity was almoction under low pH (3.5) conditions. Finally, we speculated if the pH of acid rain ≤ 3.5, with 1‰ salinity and 2-h rainfall time, the amount of U. prolifera and the scale of green tides would decreast completely inhibited. Moreover, the low salinity (1‰ and 10‰) reduced the degree of photoprotese. [ABSTRACT FROM AUTHOR]

Sargassum horneri (Turner) C. Agardh is a genus of brown algae and plays an important role in marine ecosystem. However, the inhabiting area of S. horneri has been decreasing sharply in China. To understand the photoacclimation and photoregulation strategies of S. horneri in responses to temperature and light, S. horneri was cultured under different temperatures [18°C (LT) and 26°C (HT)] and light intensities [60 µmol(photon) m-2 s-1 (LL) and 120 µmol(photon) m-2 s-1 (HL)] for 7 d, and then the chlorophyll a fluorescence parameters were measured. The results showed that the maximum electron transfer rate occurred at low temperature and high light (LT-HL) condition. The high temperature was the predominant factor for causing inhibition of PSII, lowering the effective quantum yield of PSII, and reducing the nonphotochemical quenching (NPQ). However, high light could improve the photoprotective ability via enhancing the NPQ. On the other hand, a strong linear relationship was observed between NPQ and the electron transport efficiency (a); the increase of NPQ could reduce the a value and avoid damage from high light stress to PSII. Therefore, S. horneri was found to be well adapted to grow under LT-HL conditions. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We aimed to compare and analyze the long-term efficacy and safety between kelp micro gelation (KMG) and gelfoam particles in partial splenic embolization (PSE). PATIENTS AND METHODS: This study retrospectively included 65 liver cirrhosis patients with comorbidity of hypersplenism who were admitted in Nanfang Hospital from July 2008 to May 2012. Among the included patients, 33 patients were in KMG-PSE group, and 32 cases were included in Gelfoam-PSE group. According to the Child-Pugh criteria, all cases were divided into grade A, B, and C, respectively. All eligible subjects received CT or MR examination and laboratory examination. RESULTS: O ur r esults s howed t hat b oth K MG and gelfoam particles could substantially improve the short-term efficacy of thrombocytopenia leukopenia. However, the efficacy of KMG is superior to that of gelfoam. Due to the characteristic of KMG as a permanent agent, KMG may result in an obvious pain in the spleen after PSE, especially in patients with megalosplenia. KMG was more expensive than gelfoam particles. The complication rate in patents with great embolization was much higher than that with less embolization. CONCLUSIONS: The efficacy of KMG is superior to that of gelfoam in both short-term and long-term. To effectively control the occurrence of severe complication, the embolization should be controlled less than 70% regardless of the embolization agents. [ABSTRACT FROM AUTHOR]

Ionic actuators have attracted much attention due to their remarkably large strain under low-voltage stimulation. Here, we investigate a highly biocompatible ionic polymer actuator, which consists of multi-walled carbon nanotube (MCNT) film as a double electrode layer and an electrolyte layer equipped with chitosan polymer skeleton and ionic liquid. As a result, with the thickness increase of the electrolyte layer and the electrode layer, the membrane capacitance values are obviously improved, which are 0.01 F (membrane thickness of 1.3 mm) and 0.4 F (0.25 mm). The blocking force and its response speed show peak values of 5.75 mN (1.1 mm) and 5.1 mN (0.25 mm), while reverse increases for the displacement and its response speed are observed, which present maximum values of 10.3 mm (0.3 mm) and 13.3 mm (0.15 mm). Furthermore, for various thicknesses of the electrode layers under applied direct current of 5 V, the generated strain of 0.15 mm thickness (59%) is 4.92 times greater than that of the 0.25 mm thickness. This is against the strain difference on the electrode surface due to the growing stiffness of the electrode layer. Additionally, from the experiments of the electromechanical energy efficiency of various electrode layers and electrolyte layers, our actuator exhibits excellent electromechanical energy efficiency under a high electrical conductivity of the electrode layer, which enhance the specific electromechanical energy up to 9.95%. [ABSTRACT FROM AUTHOR]

In this paper a doubly Q-switched 1.06 μm Nd:YVO4 pulse laser with acoustic-optic (AO) Q-switch and Cr4+:YAG saturable absorber passive Q-switch was demonstrated. The pulse width was compressed from 22.6 to 17.5 ns and the pulse peak power was increased from 3.92 to 4.17 kW for the doubly Q-switched laser when compared with the acoustic-optics Q-switched laser at the conditions of incident pump power of 12 W and repetition rate of 50 kHz. [ABSTRACT FROM AUTHOR]

MoS2 and MoS2/Zr coatings were deposited on the surface of YT15 carbide by medium frequency magnetron sputtering together with multiarc ion plating. Microstructural and fundamental properties of these coatings were examined. Sliding wear tests against hardened steel using the ring block method were carried out with these coated materials. The friction coefficient and wear rates were measured. The wear surface features of the coatings were examined by SEM. Results showed that the MS-1 specimen (with MoS2/Zr composite coating) has the higher hardness and adhesion load for the coating to the substrate compared with that of the MS-2 specimen (only with MoS2 coating). The friction coefficient of MS-1 specimen was depended on the applied load, and was quite insensitive to the sliding speed. The MS-1 specimen exhibits improved friction behaviour to that of the MS-2 specimens, and the antiwear lifetime of the MoS2 coatings can be prolonged through adding Zr additives. [ABSTRACT FROM AUTHOR]

ZnO-coated zinc antimonate (ZnSb2O4) nanocables have been fabricated via a simple one-step thermal evaporation of layered powders of Sb2O3 and ZnO on a brass substrate. The samples were characterized using X-ray diffraction, scanning electron microscopy and high resolution transmission electron microscopy with a high-angle annular dark-field attachment. The nanocables are several tens of micrometers in length; the ZnSb2O4 core is ∼30 nm in diameter and the thickness of the ZnO sheath is ∼5 nm. Both the ZnSb2O4 core and the ZnO sheath are single crystalline. The controlled growth mechanism of ZnO-coated ZnSb2O4 nanocables was considered to be the combination of oxide-assisted evaporation and vapor–solid processes. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about a new method of synthesizing nanoparticles for application in volatile organic compounds gas sensors.

We designed and fabricated a composite magnetic recording medium with exchange decoupled magnetic grains that consist of two vertically exchange-coupled magnetic regions (one is magnetically soft and one is magnetically hard) as an approach to alleviate the writing field limitation of perpendicular magnetic recording heads. A nonmagnetic layer with different thickness was put between the hard and soft layer to tune the exchange coupling. With proper coupling, significant drop of the coercivity field was observed for this composite medium while still maintaining good thermal stability. Better recording performance was obtained for such medium compared to perpendicular and longitudinal medium. The results have proved the possibility of fabricating a writable recording medium having an ultrahigh magnetic anisotropy constant (Ku) value. [ABSTRACT FROM AUTHOR]

The Altai Mountains (ALE) and the Greater Khingan Mountains (GKM) in northern China are forest regions dominated by coniferous trees. These geographically isolated regions provide an ideal setting for studying microbial biogeographic patterns. In this study, we employed high-throughput techniques to obtain DNA sequences of soil myxomycetes, bacteria, and fungi and explored the mechanisms underlying the assembly of both local and cross-regional microbial communities in relation to environmental factors. Our investigation revealed that the environmental heterogeneity in ALE and GKM significantly affected the succession and assembly of soil bacterial communities at cross-regional scales. Specifically, the optimal environmental factors affecting bacterial Bray-Curtis similarity were elevation and temperature seasonality. The spatial factors and climate change impact on bacterial communities under the geographical barriers surpassed that of local soil microenvironments. The assembly pattern of bacterial communities transitions from local drift to cross-regional heterogeneous selection. Environmental factors had a relatively weak influence on myxomycetes and fungi. Both soil myxomycetes and fungi faced considerable dispersal limitation at local and cross-regional scales, ultimately leading to weak geographical distribution patterns.IMPORTANCEThe impact of environmental selection and dispersal on the soil microbial spatial distribution is a key concern in microbial biogeography, particularly in large-scale geographical patterns. However, our current understanding remains limited. Our study found that soil bacteria displayed a distinct cross-regional geographical distribution pattern, primarily influenced by environmental selection. Conversely, the cross-regional geographical distribution patterns of soil myxomycetes and fungi were relatively weak. Their composition exhibited a weak association with the environment at local and cross-regional scales, with assembly primarily driven by dispersal limitation., Competing Interests: The authors declare no conflict of interest.

Objective: To establish a high performance liquid chromatography method for the simultaneous determination of dimethyl oxalate (DMO) and diethyl oxalate (DEO) in workplace air. Methods: From January 2022 to January 2023, air samples were collected by silica gel tubes, desorbed by acetonitrile, separated by C18 chromatographic column, detected by photo-array detector, and retention time was used to characterize and peak area was used to quantify at 210 nm wavelength. Results: The linear relationships of DMO and DEO were good, r >0.999. The detection limits of DMO and DEO were 0.39 and 0.52 μg/ml, respectively. The quantitative limit was 1.28 μg/ml for DMO and 1.72 μg/ml for DEO. Average desorption efficiency for DMO was 82.40%-92.72%, and DEO was 94.13%-97.69%. The intra-assay precision of DMO was 1.87%-6.18%, and DEO was 2.25%-3.31%. Inter-assay precision of DMO was 3.29%-5.73%, and DEO was 1.38%-2.94%. Average sampling efficiencies were 100% for both DMO and DEO. Breakthrough capacity of DMO was 37.61 mg (200 mg solid adsorbent), DEO was >28.11 mg (200 mg solid adsorbent). Samples should be stored at 4 ℃ for at least 7 days. Conclusion: This method is easy to operate and has strong practicability. All indicators meet the requirements of the specification, and it is suitable for the simultaneous determination of DMO and DEO in the workplace air.

Objective: To establish a high performance liquid chromatography method for the determination of 2-thioxothiazolidine-4-carboxylic acid (TTCA) in urine. Methods: After acidification with hydrochloric acid, TTCA in urine was first extracted by ethyl acetate with excessive sodium chloride, then gradient separated by a symmetry C18 column and then detected by a diode array detector. The quantification was based on a working curve of external standard method. Results: The linear relationship of TTCA in urine was good in the range of 0.03-10.00 mg/L, and the correlation coefficient was 0.9999. The detection limit and minimum quantitative concentration of TTCA in urine were 0.008 mg/L and 0.027 mg/L. The intra-assay precision of the method was 0.9%-1.4%, the inter-assay precision was 1.3%-3.5%, and the average recovery was 85.0%-92.7% while the concentrations of TTCA in urine was 0.8, 2.0 and 8.0 mg/L, respectively ( n =6) . Conclusion: The gradient elution high performance liquid chromatography method has simple operation and high sensitivity, and it is suitable for the determination of TTCA on a low level in urine for occupational workers exposure to carbon disulfide.

Objective: To explore the correlation of cytochrome B-245 alpha chain ( CYBA ) rs4673 and cholesteryl ester transfer protein ( CETP ) rs12720922 polymorphisms with the susceptibility of gene-ralized aggressive periodontitis (GAgP)., Methods: The study was a case-control trial. A total of 372 GAgP patients and 133 periodontally healthy controls were recruited. The CYBA rs4673 and CETP rs12720922 polymorphisms were detected by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Logistic regression models were used to analyze the correlation of CYBA rs4673 and CETP rs12720922 variants with the susceptibility of GAgP. The interaction between the two gene polymorphisms to the susceptibility of GAgP was analyzed by the likelihood ratio test. The interaction model adopted was the multiplication model., Results: The mean age of GAgP group and control group was (27.5±5.2) years and (28.8±7.1) years respectively. There was significant difference in age between the two groups ( P < 0.05). The gender distribution (male/female) was 152/220 and 53/80 respectively, and there was no significant difference between GAgP group and controls ( P >0.05). For CYBA rs4673, the frequency of CT/TT genotype in the GAgP group was significantly higher than that in the controls [18.0% (66/366) vs . 10.6% (14/132), P < 0.05]. After adjusting age and gender, the individuals with CT/TT genotype had a higher risk of GAgP ( OR =1.86, 95% CI : 1.01-3.45, P < 0.05), compared with CC genotype. There was no statistically significant difference in distributions of the CETP rs12720922 genotypes (GG, AA/AG) between GAgP patients and healthy controls ( P >0.05). A significant interaction between CYBA rs4673 and CETP rs12720922 in the susceptibility to GAgP was observed. The GAgP risk of the individuals with CYBA rs4673 CT/TT and CETP rs12720922 GG genotypes was significantly increased ( OR =3.25, 95% CI : 1.36-7.75, P < 0.01), compared with those carrying CC and AA/AG genotypes., Conclusion: CYBA rs4673 CT/TT genotype is associated with GAgP susceptibility. There is a significant interaction between CYBA rs4673 CT/TT genotype and CETP rs12720922 GG genotype in the susceptibility of GAgP.

Glaucoma is the world's leading cause of irreversible blindness. As a chronic disease, it requires lifelong follow-up and management. In the long-term follow-up of glaucoma patients, a diagnosis and treatment management system is helpful. Despite the availability of various means of informationalized record management, there remain problems and challenges, like a lack of unified file management standards, data incompatibility, and barriers to inter-hospital data sharing, which lead to the failure to establish a comprehensive and standardized glaucoma record for patients. It is necessary to form a standardized management system so as to improve the efficiency and accuracy of the diagnosis and treatment of glaucoma, better maintain the visual function of patients and reduce the burden on society and family.

Objective: To develop a method for simultaneous determination of Dydroquinone, Resorcinol, Pyrocatechol, 4-Nitrophenol and 2, 4-Dinitrophenol in workplace air by high performance liquid chromatography. Methods: Air samples were collected by composite tube (front end glass fiber filter membrane, back section silica gel) , 10% methanol was desorbed, separated by C18 chromatographic column, detected by photo-diode array (PDA) detector, and quantitatively determined by external standard method at the wave-length of 230 nm. Results: The linear relationship of 5 phenolic compounds was good ( r >0.999) . The detection limit of glass fiber filtration membrane and silica gel adsorbent were 0.13-0.41 g/ml and 0.16-1.04 g/ml respectively. The quantitative limit of glass fiber filtration membrane was 0.44-1.36 g/ml, and the silica gel adsorbent was 0.52-3.46 g/ml. The average desorption efficiency of glass fiber membrane and silica gel adsorbent were 97.5%-100.1% and 86.9%-100.3%, respectively. In and between batches, the precision glass fiber filtration membrane was 0.71%-4.88%, 0.91%-4.82%, silica gel adsorbent was 0.47%-4.62%, 0.76%-5.52%. Samples can be stored for at least 30 days at -20 ℃. The possible co-existing interferences of aniline, phenol, p-nitrochlorobenzene, o-nitrophenol and trinitrophenyl did not interfere with the determination. Conclusion: The sensitivity, precision, accuracy and linear range of this method all meet the requirements of the specification. The collection and preservation of samples can also meet the requirements of the limits. It is suitable for the simultaneous determination of hydroquinone, resorcinol, hydroquinone, hydroquinone, hydroquinone, p-nitrophenol and 2, 4-dinitrophenol in the air of the workplace.

Sepsis is a common cause of death in intensive care unit. Some retrospective studies had shown the combination of hydrocortisone, ascorbic acid and thiamine (HAT therapy) could lower mortality rate of patients with sepsis or septic shock. Recently, multiple randomized controlled trials(RCTs) related to the efficacy of combination therapy don't reach a consensus. Though one meta-analysis indicated beneficial effect of HAT regimen on decreasing mortality rate of patients with sepsis or septic shock, improving SOFA score and reducing use of vasopressor. However, controversy still exist in the target population, timing, dose and duration of HAT regimen. Thus, the optimized RCTs are needed to provide more definitive evidence.

Objective: To investigate the association of low serum indirect bilirubin (IBIL) level with all-cause mortality in maintenance hemodialysis (MHD) patients. Methods: A multicenter retrospective cohort study was conducted in seven hemodialysis centers of Guizhou province. The adult outpatients who underwent hemodialysis for more than 3 months were included between June 2015 and June 2016. Demographics, baseline clinical and laboratory test results were collected. Patients were divided into 4 groups according to their baseline serum IBIL levels (interquartile range), and followed up until June 30, 2018. Kaplan-Meier method was used to compare the survival rate of each group. Cox regression model was used to analyze the association of IBIL with all-cause mortality. Results: A total of 885 hemodialysis dialysis patients with baseline IBIL data were enrolled in this study, with age of (55.4±16.2) years old, among whom 57.9% (512/885) were male. Median IBIL was 4.8 μmol/L and interquartile range was 3.3-7.0 μmol/L. The comparison between IBIL quartile groups showed that the differences in proportion of diabetics, hemoglobin, serum albumin, platelet, serum calcium, alanine aminotransferase (ALT), uric acid and urea nitrogen were statistically significant (all P <0.05). After a median follow-up of 24 months, 210 patients died, and 96 cases became lost to follow-up. Kaplan-Meier curves showed higher all-cause mortality in patients with IBIL≤3.3 μmol/L (Q1 group) (65/219, P =0.015). After adjusting for age, gender, comorbidities, and biochemical indicators, taking baseline IBIL Q2 level (IBIL 3.4~4.8 μmol/L) as a reference, the hazard ratio for all-cause death in patients with IBIL≤3.3 μmol/L was 1.661 (95% CI : 1.114-2.476, P =0.013). Kaplan-Meier survival curve showed that there was no significant difference in mortality between the quartile groups according to total bilirubin (TBIL) or direct bilirubin (DBIL) ( P =0.167, 0.156). Conclusion: Baseline low serum IBIL in maintenance hemodialysis patients is associated with all-cause mortality.

Objective: To compare the short-term outcomes of a collagen matrix (CM) and free gingival graft (FGG) in augmenting keratinized mucosa around dental implants. Methods: Nineteen partially edentulous patients who had undergone implant surgery or implant review from June 2017 to June 2018 at Department of Periodontology, Peking University School and Hospital of Stomatology with lack of keratinized mucosa at buccal aspect of implants (<2 mm) were recruited in this study. According to the width of keratinized mucosa (KW) pre-operation, 9 patients including 5 males and 4 females were assigned into control group (KW<0.5 mm) which performed free gingival graft (17 implants) and 10 patients including 3 males and 7 females were assigned into experimental group (KW≥0.5 mm) which used collagen matrix as the grafts (15 implants). The KW at buccal aspect of each implant were measured pre-operation and 2 weeks, 1 month, 2 months, 3 months after surgery respectively. Each of the patients was required to fill out a questionnaire using a visual analogue scale to assess the postoperative morbidity. Results: The KWs around implants were increased significantly during the 3 months follow-up period in both groups ( P< 0.01). At 3 months after surgery, KW gain in control group was (3.44±1.64) mm, in experimental group was (2.30±0.82) mm, the difference between two groups was statistically significant ( P< 0.05). Meantime, the total shrinkage of KW in control group [(34±25)%] and experimental group [(51±11)%] also showed a statistically significant difference ( P< 0.01). However, by using collagen matrix as the grafts, augmented tissues had a much more comparable appearance with adjacent tissues than that in control group. And the patients of experimental group experienced much less postoperative bleeding than those of control group. Conclusions: Both collagen matrix and free gingival graft can significantly increase the KW around implants within the 3 months post-surgery follow-up period. There were more KW gain and less shrinkage in group FGG than that in group CM. However, surgery time were reduced and the postoperative bleeding were less in group CM than in group FGG as no harvesting procedure was needed.

Objective: We aimed to compare and analyze the long-term efficacy and safety between kelp micro gelation (KMG) and gelfoam particles in partial splenic embolization (PSE)., Patients and Methods: This study retrospectively included 65 liver cirrhosis patients with comorbidity of hypersplenism who were admitted in Nanfang Hospital from July 2008 to May 2012. Among the included patients, 33 patients were in KMG-PSE group, and 32 cases were included in Gelfoam-PSE group. According to the Child-Pugh criteria, all cases were divided into grade A, B, and C, respectively. All eligible subjects received CT or MR examination and laboratory examination., Results: Our results showed that both KMG and gelfoam particles could substantially improve the short-term efficacy of thrombocytopenia leukopenia. However, the efficacy of KMG is superior to that of gelfoam. Due to the characteristic of KMG as a permanent agent, KMG may result in an obvious pain in the spleen after PSE, especially in patients with megalosplenia. KMG was more expensive than gelfoam particles. The complication rate in patents with great embolization was much higher than that with less embolization., Conclusions: The efficacy of KMG is superior to that of gelfoam in both short-term and long-term. To effectively control the occurrence of severe complication, the embolization should be controlled less than 70% regardless of the embolization agents.

Objective: To compare the community viral load (CVL) among MSM in 15 cities in China using standardized national reference sources. Methods: The study analyzed the existing database of National Major Science and Technology Project of China. The database was established with serial random survey of MSM HIV CVL among MSM in 15 cities from 2013 to 2015. VL tests were conducted in 15 laboratories with different equipment and methods, including RT-PCR, nucleic acid sequence based amplification (NASBA), branched DNA testing (bDNA) and Abbott M2000 RealTime system (M2000). Based on proficiency test for 15 laboratories conducted by National HIV Reference Laboratory, VL test values detected with EasyQ, bDNA and M2000 were converted and standardized into resultant values of TaqMan 2.0. Software SPSS 17.0 was used to produce descriptive statistics for the dataset. Results: From 2014 to 2015, the 15 testing sites were found to use a number of different viral load detection techniques. In 2014, the community viral load values were (2.38±1.47) and (2.99±1.31) in 15 testing sites, while in 2015 these values were found to be (2.07±1.34) and (2.72±1.19). The measurement of community VL was done using standard benchmarks of ≤200 copies/ml, ≤400 copies/ml and ≤1 000 copies/ml, that were used for reference for now. Conclusion: It is necessary to use standard detection method to improve the comparability of annual results. Using a standardized rate of ≤400 copies/ml or ≤1 000 copies/ml for successful control of VL was found with high stability for the result comparison among different areas.

Objective: To understand the distribution of population viral load (PVL) data in HIV infected men who have sex with men (MSM), fit distribution function and explore the appropriate estimating parameter of PVL. Methods: The detection limit of viral load (VL) was ≤ 50 copies/ml. Box-Cox transformation and normal distribution tests were used to describe the general distribution characteristics of the original and transformed data of PVL, then the stable distribution function was fitted with test of goodness of fit. Results: The original PVL data fitted a skewed distribution with the variation coefficient of 622.24%, and had a multimodal distribution after Box-Cox transformation with optimal parameter ( λ ) of-0.11. The distribution of PVL data over the detection limit was skewed and heavy tailed when transformed by Box-Cox with optimal λ =0. By fitting the distribution function of the transformed data over the detection limit, it matched the stable distribution (SD) function ( α =1.70, β =-1.00, γ =0.78, δ =4.03). Conclusions: The original PVL data had some censored data below the detection limit, and the data over the detection limit had abnormal distribution with large degree of variation. When proportion of the censored data was large, it was inappropriate to use half-value of detection limit to replace the censored ones. The log-transformed data over the detection limit fitted the SD. The median ( M ) and inter-quartile ranger ( IQR ) of log-transformed data can be used to describe the centralized tendency and dispersion tendency of the data over the detection limit.

Objective: To compare results of different methods: in organizing HIV viral load (VL) data with missing values mechanism. Methods We used software SPSS 17.0 to simulate complete and missing data with different missing value mechanism from HIV viral loading data collected from MSM in 16 cities in China in 2013. Maximum Likelihood Methods Using the Expectation and Maximization Algorithm (EM), regressive method, mean imputation, delete method, and Markov Chain Monte Carlo (MCMC) were used to supplement missing data respectively. The results: of different methods were compared according to distribution characteristics, accuracy and precision. Results HIV VL data could not be transferred into a normal distribution. All the methods showed good results in iterating data which is Missing Completely at Random Mechanism (MCAR). For the other types of missing data, regressive and MCMC methods were used to keep the main characteristic of the original data. The means of iterating database with different methods were all close to the original one. The EM, regressive method, mean imputation, and delete method under-estimate VL while MCMC overestimates it. Conclusion: MCMC can be used as the main imputation method for HIV virus loading missing data. The iterated data can be used as a reference for mean HIV VL estimation among the investigated population.