Adherence to guidelines and central-line-associated bloodstream infection occurrence during insertion and maintenance of intravascular catheters: evidence from 20 tertiary hospitals.

OBJECTIVE: To investigate adherence to intravascular catheter (IVC) insertion and maintenance guidelines in Chinese tertiary hospitals. METHODS: A cross-sectional questionnaire survey of adult inpatients with IVC placements was conducted from July to September 2022 in 20 tertiary hospitals in China. One clinical staff member from each department in each hospital was assigned to participate in the survey. Questionnaires were uniformly collected and reviewed after three months. RESULTS: This study included 1815 cases (62.69%) of central venous catheter, 471 cases (16.27%) of peripherally inserted central catheter, 461 cases (15.92%) of PORT, and 147 cases (5.08%) of haemodialysis catheter insertions. Statistically significant differences in compliance were observed across the four IVC types, specifically in relation to the insertion checklist, standard operating procedure, and insertion environment (P<0.05). Practice adherence during IVC maintenance differed significantly across the four IVC types in aspects such as availability of IVC maintenance verification forms, daily scrubbing of the catheterized patients, and catheter connection methods (P<0.05). A total of 386 (13.34%) patients developed fever, 1086 (37.53%) were treated with therapeutic antibiotics, 16 (0.55%) developed central-line-associated bloodstream infections, two (0.07%) developed local skin infections, and six (0.21%) developed deep vein thrombosis. CONCLUSIONS: Adherence to guidelines regarding insertion and maintenance differed across the four IVC types; there is a gap between the recommended measures and the actual operation of the guidelines. Therefore, it is necessary to further enhance training and develop checklists to prevent central-line-associated bloodstream infections.

An E-band multi-channel Doppler backscattering system on EAST.

An E-band (60-90 GHz) multi-channel Doppler backscattering (DBS) system with X-mode polarization has been installed on the Experimental Advanced Superconducting Tokamak (EAST), which can measure the turbulence at five different radial locations simultaneously. This system can launch 31 fixed microwave frequencies in the range of 60-90 GHz with a 1 GHz interval into the plasma, and five probing signals are selected by employing a reference signal and multiple filters. During experiments, the frequency of the reference signal is tunable in the E-band, and the selected probing signals can be changed as needed without any other adjustments, which can be performed in one shot or between shots. Furthermore, the incident angle can be adjusted from -10° to 20°, and the wavenumber range is 4-25 cm-1 with a wavenumber resolution of Δk/k ≤ 0.35. Ray tracing simulations are employed to calculate the scattering locations and the perpendicular wavenumber. In this article, the hardware design, ray tracing, and initial results obtained from the EAST plasma will be presented.

[Progress in risk factors and potential biomarkers of esophageal squamous cell carcinoma].

Esophageal cancer is the main malignant cancer in China. In 2015, the incidence and mortality of esophageal cancer were 17.87 per 100 000 and 13.68 per 100 000, respectively, ranking 6th and 4th in the incidence and death. Esophageal squamous cell carcinoma (ESCC) is the main pathological type of esophageal cancer, accounting for 86.3% of new cases. ESCC's pathogenesis is still not clear and its related risk factors remain to be explored. There are no detection biomarkers that can be widely applied in the whole country nowadays. In order to provide a scientific basis for exploring the pathogenesis of ESCC and improve screening technology, this paper summarizes the research status of various risk factors and potential biomarkers of ESCC.

The cross-polarization scattering system for the magnetic fluctuation measurement in the Experimental Advanced Superconducting Tokamak.

The cross-polarization scattering (CPS) system for magnetic fluctuation measurements in the Experimental Advanced Superconducting Tokamak (EAST) has been designed and installed. Different from the Doppler reflectometer (DR) system, the CPS system detects the perpendicular polarization of the electromagnetic wave induced by magnetic fluctuations B̃. The CPS system in the EAST has been developed from the existing Doppler reflectometer system, and they are integrated together for simultaneous measurement of magnetic and density fluctuations. Ray-tracing simulations are used to calculate the scattering locations and the wavenumber coverage of the magnetic fluctuation for CPS. In the experiments, the CPS and DR system data were different in Doppler shift, amplitude, and spectrum broadening. In this article, the hardware design, the ray tracing, and the preliminary results of the system in the EAST are presented.

TIPE2 and PCNP expression abnormalities in peripheral blood mononuclear cells associated with disease activity in rheumatoid arthritis: a meta-analysis.

OBJECTIVE: Rheumatoid arthritis (RA) is a prevalent chronic autoimmune disease posing a considerable burden on both individuals and society. Tumor necrosis induced protein 8-like 2 (TIPE2), closely related to PEST-containing nuclear protein (PCNP) expression, is an immune-related protein potentially involved in the pathogenesis of autoimmune diseases. In this study, we aimed to assess differential expressions of TIPE2 and PCNP in peripheral blood mononuclear cells (PBMCs) between active and inactive RA patients. MATERIALS AND METHODS: Relevant studies were selected from Medline, Google Scholar, Web of Science, and China National Knowledge Infrastructure (CNKI). Only observational studies (irrespective of publication status, language, or blinding), which compared patients in high disease activity, irrespective of the sample size, with patients in low disease activity of RA were evaluated. RESULTS: Four studies were included with 248 patients, 138 in the active group and 110 in the inactive group. Three studies provided data on TIPE2 expression levels, where 106 patients were divided into the active group and 88 patients were divided into the inactive group. The pooled analysis revealed a statistically significant difference between the two groups (WMD: 5.60; 95% CI: 5.02-6.18). Two studies provided data on PCNP expression levels, where 64 patients were divided into the active group and 44 patients were divided into the inactive group. The pooled analysis revealed a statistically significant difference between the two groups (WMD: 7.76; 95% CI: 3.09-12.43). CONCLUSIONS: The expression levels of TIPE2 and PCNP are significantly increased in PBMCs of active RA patients.

[The status and related factors of myopia for children and adolescents aged 5-18 years old in Shaanxi Province in 2018].

In 2018, the myopia detection rate of children and adolescents aged 5-18 years old in Shaanxi Province was 54.9% (11 060/20 144). The myopia detection rate of girls ï¼»58.6%(5 830/9 949)ï¼½ was higher than that of boys ï¼»58.6% (3 416/5 830)ï¼½ (P<0.001). In children and adolescents, the myopia detection rate increased with the age before their 16 years old, and saw a stable or downward trend after the age of 16. After adjusting the confounding factors, the myopia detection rate of children and adolescents from regions with per capita GDP>100 000 yuan was higherthan that of children and adolescents from regions with per capita GDP<50 000 yuanï¼»OR (95%CI):1.58(1.34-1.87)ï¼½.

[Epidemiological characteristics of COVID-19 in Shaanxi province].

Objective: To understand the incidence trend and epidemiological characteristics of COVID-19 in Shaanxi province. Methods: The incidence data of COVID-19 reported in Shaanxi as of 22 February, 2020 were collected for an epidemiological descriptive analysis. Results: A total of 245 confirmed cases of COVID-19 were reported in Shaanxi. Most cases were mild (87.76%). As time passed, the areas where confirmed cases were reported continued to increase. The case number in Xi'an was highest, accounting for nearly half of the total reported cases in the province. The epidemic pattern in Shaanxi had gradually shifted from imported case pattern to local case pattern, and the transmission of local cases was mainly based on family cluster transmission. The confirmed cases from different sources had caused the secondary transmission in Shaanxi. After February 7, the number of reported cases began to fluctuate and decrease stably, indicating a decrease-to-zero period. Conclusions: At present, the overall epidemic of COVID-19 in Shaanxi has gradually been mitigated. However, considering the approaching of return to work and study and the increasing of imported cases from other countries, the prevention and control of COVIS-19 in Shaanxi will face new challenges.

[WITHDRAWN: Potential false-positive rate among the 'asymptomatic infected individuals' in close contacts of COVID-19 patients].

Editor office's response for Ahead of Print article withdrawn The article "Potential false-positive rate among the 'asymptomatic infected individuals' in close contacts of COVID-19 patients" was under strong discussion after pre-published. Questions from the readers mainly focused on the article's results and conclusions were depended on theoretical deduction, but not the field epidemiology data and further researches were needed to prove the current theory. Based on previous discussions, the article was decided to be offline by the editorial board from the pre-publish lists. Objective: As the prevention and control of COVID-19continues to advance, the active nucleic acid test screening in the close contacts of the patients has been carrying out in many parts of China. However, the false-positive rate of positive results in the screening has not been reported up to now. But to clearify the false-positive rate during screening is important in COVID-19 control and prevention. Methods: Point values and reasonable ranges of the indicators which impact the false-positive rate of positive results were estimated based on the information available to us at present. The false-positive rate of positive results in the active screening was deduced, and univariate and multivariate-probabilistic sensitivity analyses were performed to understand the robustness of the findings. Results: When the infection rate of the close contacts and the sensitivity and specificity of reported results were taken as the point estimates, the positive predictive value of the active screening was only 19.67%, in contrast, the false-positive rate of positive results was 80.33%. The multivariate-probabilistic sensitivity analysis results supported the base-case findings, with a 75% probability for the false-positive rate of positive results over 47%. Conclusions: In the close contacts of COVID-19 patients, nearly half or even more of the 'asymptomatic infected individuals' reported in the active nucleic acid test screening might be false positives.

[The role of autophagy in PM2.5-induced inflammation in human nasal epithelial cells].

Objective: To explore the role of autophagy in PM2.5-induced inflammation in human nasal epithelial cells and related mechanism. Methods: Human nasal epithelial cells were exposed to different concentration of PM2.5 for different times, and the expression levels of microtubule-associated protein-1 light chain-3 Ⅱ (LC3 Ⅱ) and Beclin1 proteins were measured by Western blot. The typical autophagosome and autolysosome were observed by using transmission electron microscopy (TEM). To observe autophagic flux, mRFP-GFP-LC3 plasmid was transfected to nasal epithelial cells and the punctate staining of mRFP-GFP-LC3 were determined by confocal laser scanning microscope. The expression of inflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) in cell culture supernatant were assessed by enzyme-linked immunosorbent assay (ELISA). To assess the role of autophagy in PM2.5-mediated inflammation, autophagy related gene Atg5 and Beclin-1 were silenced by siRNA knockdown, and inflammatory cytokines were analyzed.GraphPad Prism 6.0 was used for statistical analysis. Results: PM2.5 exposure increased the expression of LC3 Ⅱ and Beclin-1 proteins in a dose- (in PM2.5 group with concentration of 0, 15, 30, 60, 120 µg/ml, the expression of LC3 Ⅱ was 0.021±0.001(x±s), 0.037±0.002, 0.058±0.005, 0.075±0.006, 0.085±0.004, respectively, F=126.8, P<0.05; the expression of Beclin-1 was 0.002±0.000, 0.003±0.000, 0.005±0.000, 0.007±0.001, 0.008±0.001, respectively, F=137.3, P<0.05) and time-dependent manner (in PM2.5 group with exposure time of 0, 3, 6, 12, 24 h, the expression of LC3Ⅱ was 0.160±0.007, 0.222±0.003, 0.251±0.015, 0.483±0.029, 0.585±0.035, respectively, F=215.3, P<0.05; the expression of Beclin-1 was 0.059±0.002, 0.080±0.002, 0.087±0.002, 0.183±0.007, 0.228±0.005, respectively, F=137.3, P<0.05) in human nasal epithelial cells. TEM analysis showed typical autophagosome and autolysosome in cells after PM2.5 exposure for 24 h. PM2.5 significantly increased the number of yellow and red dots representing autophagosomes and autolysosomes respectively, indicating autophagic flux was elevated. Moreover, PM2.5 enhanced the secretion of inflammatory cytokines such as IL-6 and TNF-α, which was dramatically prevented by Atg5-siRNA and Beclin-1-siRNA. Conclusion: Autophagy plays an important role in PM2.5-caused inflammation response in nasal epithelial cells, which can induce release of inflammatory factors such as IL-6 and TNF-α and advance the inflammatory reaction.

[Effect of PM2.5 on inflammatory factors and pathology of nasal mucosa in a rat model of allergic rhinitis].

Objective: To investigate the effect of PM2.5 exposure on nasal inflammatory cytokines and nasal mucosal pathology in a rat model of allergic rhinitis (AR). Methods: Twenty-four healthy female SD rats were randomly divided into 3 groups by random number table method, with 8 rats in each group: normal control group (NC group), ovalbumin (OVA) induced AR model (AR group), and AR model group inhaled to PM2.5 at 200 µg/m(3), 3 h/d, for 30 d (ARE group). Nasal symptoms including sneezing, nasal rubs and nasal secretion were recorded. Levels of OVA specific IgE in serum, interleukin 6 (IL-6) and tumor necrosis factor-ɑ (TNF-ɑ) in nasal irrigating solution were measured by enzyme-linked immunosorbent assay (ELISA). The histopathological changes of nasal mucosa were observed by HE staining. SPSS 17.0 software was used to analyze the data. Results: The number of sneezing, nasal rubs and the amount of nasal secretion in the ARE group were significantly higher than that in the AR group and the NC group (number of sneezing (15.38±1.68) times/15 min vs (11.63±1.13) times/15 min vs (1.75±0.71) times/15 min, number of nasal rubs (27.75±2.12) times/15 min vs (21.25±2.96) times/15 min vs (5.25±1.04) times/15 min, amount of nasal secretion (18.90±2.07) mg vs (13.83±1.81) mg vs (3.78±0.41) mg, F values was 236.089, 224.139, 183.971, respectively, all P<0.001). Statistically significant differences in OVA specific IgE, IL-6 and TNF-ɑ levels were observed in ARE group exceeded AR group and NC group (OVA specific IgE (25.42±2.51) ng/ml vs (18.07±1.07) ng/ml vs (1.47±0.26) ng/ml, IL-6 (123.30±18.86) pg/ml vs (63.49±11.29) pg/ml vs (16.87±3.29) pg/ml, TNF-ɑ (162.50±38.15) pg/ml vs (72.96±11.28) pg/ml vs (27.52±4.15) pg/ml, F values was 481.604, 138.277, 63.938, respectively, all P<0.001). HE staining showed that the nasal epithelial cells of NC group were intact and neatly arranged. Nasal mucosa epithelial cells were arranged in disorder in AR group, with tissue structure swelling. Partial shedding of nasal epithelial cells, mucosal basement membrane thickening, submucosal tissue interstitial edema, vasodilation and gland hyperplasia were found in ARE group. Conclusion: An increase inflammatory factors level such as IL-6 and TNF-ɑ aggravates pathological damage of nasal mucosa in a rat model of AR by exposure to PM2.5.

Five-channel tunable W-band Doppler backscattering system in the experimental advanced superconducting tokamak.

A 5-channel Doppler backscattering system has been designed and installed in the Experimental Advanced Superconducting Tokamak (EAST). Through an I/Q-type double sideband modulator and a frequency multiplier, an array of finely spaced (Δf = 400 MHz) frequencies that span 1.6 GHz has been created. The center of the array bandwidth is tunable within the range of 75-97.8 GHz, which covers most of the W band (75-110 GHz). The incident angle can be adjusted from -4° to 12°, and the wavenumber range is 4-15 cm-1 with a wavenumber resolution of Δk/k ≤ 0.35. Ray tracing is used to calculate the scattering location and the scattering wavenumber. This article details the hardware design, the ray tracing, and the preliminary experimental results from EAST plasmas.

[Effect of nonoperative periodontal treatment on changes of schneiderian membrane thickness of maxillary sinus in the chronic periodontitis patients using cone-beam CT].

Objective: To analysis the effect of nonoperative periodontal treatment on morphological changes of the schneiderian membrane of maxillary sinus in the chronic periodontitis patients by using oro-maxillaofacial cone-beam CT (CBCT) in order to provide the foundation in the diagnosis and treatment of maxillary sinusitis caused by chronic periodontitis. Methods: Totally 30 chronic periodontitis patients with schneiderian membrane thickening [(40.0±5.6) years old (ranged 26-55 years old), 18 males and 12 females] were randomly recruited in Department of Periodontics, School of Stomatology, China Medical University from June 2014 to December 2016. All patients were scanned by CBCT. The probing depth (PD), clinical attachment loss (CAL), plaque index (PLI) and bleeding index (BI) of the maxillary first and second premolars and molars were recorded. All patients received systematic nonoperative periodontal treatment. After six months, patients were reviewed, periodontal indexes and CBCT scanning were recorded. The thickness of the schneiderian membrane of maxillary sinus were analyzed by the software of CBCT. The changes of clinical parameters, parameter dimensional values of membrane thickness before and after treatment were statistically compared by t test. Results: In 30 chronic periodontitis patients, there was no statistically significant difference in the dimension and length of the maxillary sinus mucosa between the right and the left (P>0.05). The dimension of the mucosal thickening was positively correlated with PD and CAL values, and the correlation was statistically significant (P<0.05). Totally 58 maxillary sinus showed mucosal thickening. There were 20 mild thickening cases, and the dimension of mucosal thickening 6 months after treatment [(1.1±0.6) mm] was significantly lower than that before treatment [(2.5±0.7) mm] (P<0.05). There were 30 moderate thickening cases and the dimension of mucosal thickening 6 months after treatment [(2.3±0.6) mm] was significantly lower than that before treatment [(5.8±0.5) mm] (P<0.01). There were 8 severe thickening cases and the dimension of mucosal thickening 6 months after treatment [(4.2±0.4) mm] was also significantly lower than that before treatment [(11.2±1.8) mm] (P<0.01). The periodontal indexes of patients with mild, moderate and severe mucosal thickening in maxillary sinus showed statistically significant difference after treatment compared with before treatment (P<0.05). Conclusions: Nonoperative periodontal treatment has a positive therapeutic significance for improving the schneiderian membrane thickening of maxillary sinus.

miR-199b exerts tumor suppressive functions in hepatocellular carcinoma by directly targeting JAG1.

OBJECTIVE: To investigate the regulating roles of miR-199b in hepatocellular carcinoma (HCC). PATIENTS AND METHODS: The expression of miR-199b of 45 human HCC tissues and the corresponding para-cancerous tissue samples were detected by quantitative Real-time-polymerase chain reaction (qRT-PCR). Western blot was employed to investigate the level of JAG1. Transwell assay was used to monitor the ability of cell migration and invasion. Cell proliferation was tested by CCK-8 assay and luciferase reporter assay was done to clarify whether JAG1 was a target of mir-199b. RESULTS: miR-199b expression level was decreased in 45 paired tumor tissues in contrast with the corresponding para-carcinoma tissues. The expression level of miR-199b was closely associated with TNM stage, tumor size, and 5-year overall survival. Transwell assay result showed that miR-199b inhibited HCC cell migration and invasion. Cell counting kit-8 (CCK-8) results demonstrated that miR-199b could suppress HCC cell proliferation. Luciferase reporter assay suggested that Jagged1 (JAG1) was a direct target of miR-199b in HCC cells. miR-199b could negatively regulate JAG1 expression by targeting JAG1. CONCLUSIONS: miR-199b exerted tumor suppressive functions in HCC by targeting JAG1, and it may be a potential target treatment for hepatocellular carcinoma.

Measurement of density fluctuation propagation direction via the far-forward collective scattering diagnostic based on polarimeter-interferometer.

Previously, the 17-channel three-wave polarimeter-interferometer system (POLARIS) on the J-TEXT tokamak has been implemented to measure far-forward collective scattering (FFCS) from electron density fluctuations. Recently, this system has been exploited to measure the propagation direction of density fluctuation. After considering the refraction of the laser probe beam passing through plasma, the ray tracing result shows that the detector of POLARIS may receive asymmetric far-forward scattering beams. Thus, the heterodyne detection of FFCS is available to identify the propagation direction of density fluctuation by resolving the asymmetric scattering spectrum. Experimentally, the transform of the heterodyne scattering spectrum from symmetry to asymmetry has been observed, while the refraction effect becomes strong demonstrating the capacity of measuring the propagation direction of fluctuation. Furthermore, by changing the plasma potential through the use of an applied positive electrode biasing, the reverse of frequency shift for the heterodyne scattering spectrum is identified, confirming the validity of direction discrimination of density fluctuation.

Hyperbolic lens design of local oscillator optics system for electron cyclotron emission imaging on J-TEXT.

An electron cyclotron emission imaging diagnostic system that contains two 16-antenna arrays is being developed on J-TEXT tokamak. In this heterodyne system, the mixers in the front microwave antenna are used to down-convert the electron cyclotron emission to a 2-12 GHz radio frequency. All of the 24 antenna mixers in the individual enclosure box are driven by shining local oscillator (LO) power via launching optics. The previous approach for LO optics was designed with spherical and cylinder lenses, which has limitations such as the inhomogeneity of the energy deposition on different channels and the difficulty of optics alignment. A new generation of LO optics has been designed and applied on J-TEXT with a hyperbolic lens for uniform power deposition across the entire antenna array. The robustness of the optical alignment will be significantly increased with three hyperbolic lenses. Furthermore, the simulation results and robustness analysis of these LO optics are discussed in this paper.

[The effect of PM2.5 on mucus secretion and ultrastructureof nasal mucosa in allergic rhinitis model].

Objective:The aim of this study is to the roles of nasal lavage fluid levels of MUC5AC, goblet cell hyperplasia and ultrastructure of nasal mucosa following ambient PM2.5 exposure in a rat model of allergic rhinitis(AR).Method:Female Sprague-Dawley rats were assigned randomly into 3 groups: a negative control group(NC group),an ovalbumin(OVA)-induced AR model group(AR group), and AR model group(ARE group) inhaled to PM2.5 at 200 µg/m³, 3 h/d, for 30 days. Nasal symptoms, levels of MUC5AC in nasal lavage fluid(NLF), were measured in each individual rat.Goblet cell hyperplasia were examined histologically with PAS-stained. Nasal mucosa tissue ultrastructure were observed by scanning electron microscope.Result:PM2.5 significantly increased the number of sneezes, nasal rubs and the amount of nasal secretion in rats with AR.Statistically significant differences in MUC5AC levels and goblet cell hyperplasia were observed between the AR model exposure to PM2.5 and the AR model group.The nasal mucosa of AR model exposure to PM2.5 was disordered,lodged,assembled and twisted.Conclusion:Our data indicate that an increase MUC5AC level in NLF and the development of nasal goblet cell hyperplasia may provide some clues for determining the pathogenic mechanisms of AR by exposure to PM2.5.

A novel, tunable, multimodal microwave system for microwave reflectometry system.

Based on a new technique, a tunable, multi-channel system that covers the Q-band (33-55 GHz) is presented in this article. It has a potential use of the Doppler backscattering system diagnostic that can measure the turbulence radial correlation and the perpendicular velocity of turbulence by changing the incident angle. The system consists primarily of a double-sideband (DSB) modulation and a multiplier, which creates four probing frequencies. The probing frequency enables the simultaneous analysis of the density fluctuations and flows at four distinct radial regions in tokamak plasma. The amplitude of the probing frequency can be adjusted by the initial phase of the intermediate frequency (IF) input from the double-sideband, and the typical flatness is less than 10 dB. The system was tested in the lab with a rotating grating, and the results show that the system can operate in the frequency range of 33-55 GHz with a Q-band multitude and that the power of each channel can be adjusted by the phase of the IF input of DSB.

[A meta-analysis of the test results of five indicators for hepatitis B virus of college freshmen in current mainland China].

Objective: Using Meta analysis to evaluate the test results of five indicators and main infection patterns for hepatitis B virus (HBV) of college freshmen in mainland China. Methods: In this paper, "college students", "college freshmen", "hepatitis b virus" and "HBV" were used to search systematically for cross-sectional data of the results of five indicators for HBV of entrants from 2006-2015 through CNKI, Wanfang Data, VIP as well as Pubmed and Web of Science. Then Combie's standard for cross-sectional study was used to assess the qualities of the articles included, and Stata 14.0 software and Meta analysis method (including performing heterogeneity test, calculating combined detection rates and carrying out sensitivity analysis and publication bias test) were used to analyze and evaluate the epidemiological significance of the results above. Results: Sixteen studies containing 82 144 cases were included. The result of heterogeneity test showed that there was significant heterogeneity (P<0.001), hence random effects model was adopted. The Meta analysis resulted in total positive rate for surface antigen (HBsAg) of 7.0% (95%CI: 6.0%-8.0%), surface antibody positive rate (HBsAb) of 46.0% (95%CI: 42.0%-49.0%), and positive rate for HBsAg, core antibody (HBcAb) combined with E antigen (HBeAg) or E antibody (HBeAb) of 3.0% (95%CI: 2.0%-3.0%) and 3.0% (95%CI: 2.0%-3.0%), respectively; whereas the negative rate of all indicators was 41.0% (95%CI: 35.0%-46.0%). Sensitivity analysis showed that the results were highly heterogeneous (P<0.001), while the result of Egger's regression indicated that there were publication bias of all indicators (P<0.05), except for HBsAb (P=0.436). Conclusion: The positive rates of HBsAg and HBsAb of college students are lower than those of general population, while the positive rates of HBsAg, HBcAb combined with HBeAg or HBeAb and the all-negative rate of HBV count for a considerable proportion among entrants.

Optimization of the medium for the growth of Nitrobacter winogradskyi by statistical method.

Although Nitrobacter winogradskyi is an important chemoorganotrophic organism for the study of nitrite-oxidizing bacteria physiology as well as nitrification, until now, the mixotrophic medium for this organism growth has not been optimized, comprehensively. In this study, we aimed to improve the growth medium of N. winogradskyi using the one-factor-at-a-time (NaNO2 , glycerol, pH) method. In addition, a further experimental design was carried out based on central composite design with response surface methodology. Different combinations of the three cultural parameters were fitted by multiple regression analysis to calculate the predicted response. Our results suggest that optimal culture condition for the growth of N. winogradskyi was a modified DSMZ 756a medium containing NaNO2 (5·74 g l-1 ) and glycerol (37·88 mmol l-1 ), pH 7·83, a temperature of 28°C and agitation at 120 rev min-1 . The results from a validation experiment (bacterial growth: OD600 1·0293) were close to the value predicted by the quadratic model (OD600 1·0994). In addition, we uncovered the potential mechanism at the cellular and ultrastructural levels. The results indicated that glycerol in the media enhanced the rate of cell division and cell growth by increasing the accumulation of polyphosphates and phosphorus, and high concentrations of NaNO2 provided sufficient energy for growth and contributed to the generation of carboxysomes in cells for CO2 fixation. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to the extremely slow growth rate and the low growth yield of ammonia-oxidizing bacteria and NOB (nitrite-oxidizing bacteria), nitrification is still the rate-limiting step of nitrogen cycle in the current research. Nitrobacter winogradskyi, an important NOB, participates in the second step of nitrification in water and soil. This study reported an optimized culture condition for N. winogradskyi, which increased the growth yield by 5·06 times than that in the basal medium and uncovered the potential mechanism. We expect our study will contribute to the research on water and soil nitrogen cycle. In addition, the optimized culture conditions have the potential to be suitable for the chemoorganotrophic growth of other nitrifiers.

Expression Pattern of Tumor Necrosis Factor-α-Induced Protein 8-Like 2 in Acute Rejection of Cardiac Allograft.

BACKGROUND: Tumor necrosis factor-α-induced protein-8 like-2 (TIPE2) is a negative regulator of innate immunity and cellular immunity, yet the expression pattern of TIPE2 in acute rejection of cardiac allograft remain enigmatic. METHODS: We developed cardiac transplantation models and divided into 3 groups: a naive group, a syngeneic group, and an allogeneic group. Then, we detected the messenger RNA and protein of TIPE2 in cardiac allografts. Real-time polymerase chain reaction showed expression of CD4 and CD8 in the donor heart, and immunofluorescence assay revealed the association between T cells and TIPE2. RESULTS: In our study, we first found that the expression of TIPE2 in cardiac allografts is upregulated compared with the syngeneic control, and increases in a time-dependent manner. The immunocytochemistry of heart grafts revealed a strong expression of TIPE2 in the inflammatory cells, but not in the cardiomyocytes. Finally, we proved that CD4+ and CD8+ T cells infiltrated cardiac allografts abundantly, which express ample TIPE2. CONCLUSIONS: The upregulated expression of TIPE2 in cardiac allografts, mainly came from T cells, which infiltrated the donor heart. This finding indicates that there may be an association between TIPE2 and acute cardiac allograft rejection.