A novel mechanistic model for nitrogen removal in algal-bacterial photo sequencing batch reactors

A comprehensive mathematical model was constructed to evaluate the complex substrate and microbial interaction in algal-bacterial photo sequencing batch reactors (PSBR). The kinetics of metabolite, growth and endogenous respiration of ammonia oxidizing bacteria, nitrite oxidizing bacteria and heterotrophic bacteria were coupled to those of microalgae and then embedded into widely-used activated sludge model series. The impact of light intensity was considered for microalgae growth, while the effect of inorganic carbon was considered for each microorganism. The integrated model framework was assessed using experimental data from algal-bacterial consortia performing sidestream nitritation/denitritation. The validity of the model was further evaluated based on dataset from PSBR performing mainstream nitrification. The developed model could satisfactorily capture the dynamics of microbial populations and substrates under different operational conditions (i.e. feeding, carbon dosing and illuminating mode, light intensity, influent ammonium concentration), which might serve as a powerful tool for optimizing the novel algal-bacterial nitrogen removal processes.

[Determination of tungsten and cobalt in the air of workplace by ICP-OES]

Objective: To establish the inductively coupled plasma optical emission spectrometry (ICP-OES) method for determination of cobalt and tungsten in the air of workplace. Methods: The cobalt and tungsten were collected by filter membrane and then digested by nitric acid, inductively coupled plasma optical emission spectrometry (ICP-OES) was used for the detection of cobalt and tungsten. Results: The linearity of tungsten was good at the range of 0.01-1 000 μg/ml with a correlation coefficient of 0.999 9, the LOD and LOQ were 0.006 7 μg/ml and 0.022 μg/ml, respectively. The recovery was ranged from 98%-101%, the RSD of intra-and inter-batch precision were 1.1%-3.0% and 2.1%-3.8%, respectively. The linearity of cobalt was good at the range of 0.01-100 μg/ml with a correlation coefficient of 0.999 9, the LOD and LOQ were 0.001 2 μg/ml and 0.044 μg/ml, respectively. The recovery was ranged from 95%-97%, the RSD of intra-and inter-batch precision were 1.1%-2.4% and 1.1%-2.9%, respectively. The sampling efficiency of tungsten and cobalt were higher than 94%. Conclusion: The linear range, sensitivity and precision of the method was suitable for the detection of tungsten and cobalt in the air of workplace.

[Mosquitoes, midges and related arboviruses in southeast Sichuan province]

Objective: To investigate the distribution patterns of mosquitoes, midges and related arboviruses in Sichuan province. Methods: Blood-sucking insects were collected from houses and pens, using the ultraviolet lights. Mosquito samples were classified according to morphologic characteristics and then stored at liquid nitrogen. All samples were incubated with BHK-21 and C6/36 cells for virus isolation and then detected for their viral genes. Sequences of the virus were identified and analyzed by molecular biological software, such as BioEdit 7.0.5.3, MEGA 6.0. Results: In total, 17 019 mosquitoes from 3 genera and 4 species and 12 700 midges were collected from the southeast regions of Sichuan province in 2016 and 2017. Among them, 79.4% (13 519/17 019) belonged to Culex tritaeniorhynchus with 11.1% (1 897/17 019) as Armigeres subalbatus, 5.5% (930/17 019) were Anopheles sinensis and 4.0% (673/17 019) were Anopheles sinensis 3 virus strains that isolated from Culex tritaeniorhynchus were identified as typeⅠ Japanese encephalitis virus. Seven pools of mosquitoes isolated from Hejiang county were identified Japanese encephalitis virus gene positive through PCR amplification. With 4 pool midges were detected positive for Akabane virus through PCR gene amplification while midges samples didn't have virus isolates. Conclusions: Culex tritaeniorhynchus appeared the predominant species in the southeast regions of Sichuan. Japanese encephalitis virus transmitted by mosquitoes and Akabane virus by midges were prevalent in southeast Sichuan province.

Population structure, genetic diversity and selection signatures within seven indigenous Pakistani goat populations

Goat farming in Pakistan depends on indigenous breeds that have adapted to specific agro-ecological conditions. Pakistan has a rich resource of goat breeds, and the genetic diversity of these goat breeds is largely unknown. In this study, genetic diversity and population structure were characterized from seven indigenous goat breeds using the goat 50K SNP chip. The genetic diversity analysis showed that Bugi toori goats have the highest inbreeding level, consistent with the highest linkage disequilibrium, lowest diversity and long run of heterozygosity segments. This indicates that this breed should be prioritized in future conservation activities. The population structure analysis revealed four fairly distinct clusters (including Bugi toori, Bari, Black Tapri and some Kamori) and three other breeds that are seemingly the results of admixture between these or related groups (some Kamori, Pateri, Tapri and White Tapri). The selection signatures were evaluated in each breed. A total of 2508 putative selection signals were reported. The 26 significant windows were identified in more than four breeds, and selection signatures spanned several genes that directly or indirectly influence traits included coat colour variation (KIT), reproduction (BMPR1B, GNRHR, INSL6, JAK2 and EGR4), body size (SOCS2), ear size (MSRB3) and milk composition (ABCG2, SPP1, CSN1S2, CSN2, CSN3 and PROLACTIN).

Detection of Babesia spp., Theileria spp. and Anaplasma ovis in Border Regions, northwestern China

Babesia spp., Theileria spp. and Anaplasma ovis are important intracellular agents that are transmitted by tick bites. However, Babesia spp., Theileria spp. and A. ovis in ticks have not been systematically reported along the border of northwestern China. In this study, a total of 1,084 adult ticks, including 134 Haemaphysalis punctata, 337 Hyalomma asiaticum, 233 Dermacentor nuttalli, 69 Rhipicephalus turanicus and 265 Dermacentor marginatus were collected from 11 counties or cities of Xinjiang Uygur Autonomous Region. The ticks were identified from morphological and molecular characteristics. Two fragments of 18S rRNA gene were used to determine the species level of Babesia and Theileria. Msp4 gene encoding major surface protein 4 was used to determine A. ovis. Of the 1,084 samples, five species of Babesia (B. occultans, B. caballi, B. motasi, B. major and Babesia sp. detected in this study), two kinds of Theileria (Theileria ovis and Theileria sp. detected in this study) and A. ovis with six phylogenic branches were detected in the border of northwestern China. Babesia occultans, first found in China, was first molecularly detected in D. nuttalli. Babesia caballi and Babesia sp. detected in this study were first molecularly detected in Hy. asiaticum. Genotype III of A. ovis was predominant in the border regions of northwestern China.

[Association of lipid parameters with insulin resistance in different glycemic among the elderly population]

Objective: This study was to analyze the association of lipid parameters with insulin resistance of Chinese elderly population in different glycemic status. Methods: Data were from China National Chronic Diseases and Nutrition Survey (2015). A total of 15 535 participants aged 60 and above who had completed survey questionnaire, physical examination, fasting blood biochemistry and insulin measurements were included in this study. According to the American Diabetes Association (2010) criteria, the participants were divided into normal glucose regulation, pre-diabetes, newly-diagnosed diabetes and previously-diagnosed diabetes. Multivariable logistic regression was preformed to assess the effects of lipid parameters on insulin resistance in different glycemic among the elderly population. Results: The proportion of normal glucose regulation, pre-diabetes, newly-diagnosed diabetes and previously-diagnosed diabetes was 50.46% (n=7 839), 22.19% (n=3 448), 12.46% (n=1 937) and 14.88% (n=2 311), respectively. The risk of insulin resistance increased with the elevated per quartile of triglycerides (TG) (OR=1.48,95%CI: 1.35-1.62), non-high-density lipoprotein cholesterol (Non-HDL)/HDL-C (OR=1.23, 95%CI: 1.12-1.35) and TG/HDL-C (OR=1.50, 95%CI: 1.36-1.65) and decreased with the elevated per quartile of HDL-C (OR=0.83, 95%CI: 0.76-0.90) after multivariate adjustment among normal glucose regulation participants. As for pre-diabetes participants, the risk of insulin resistance increased with the elevated per quartile of TG (OR=1.26, 95%CI: 1.14-1.39) and TG/HDL-C (OR=1.38, 95%CI: 1.24-1.54) and decreased with the elevated per quartile of HDL-C (OR=0.79, 95%CI: 0.71-0.87). The risk of insulin resistance increased with the elevated per quartiles of TG/HDL-C (OR=1.29, 95%CI: 1.12-1.48) among newly-diagnosed diabetes. As for previously-diagnosed diabetes, the risk of insulin resistance increased with the elevated per quartile of TG, Non-HDL/HDL-C and TG/HDL-C with adjusted OR(95%CI) about 1.28 (1.16-1.41), 1.37(1.21-1.55) and 1.51 (1.33-1.72) repsectivley and decreased with the elevated per quartile of HDL-C (OR=0.77, 95%CI: 0.67-0.87). Conclusion: The relationship between lipid parameters and insulin resistance presented diversely in different glycemic status. The elderly with normal glucose regulation and previously-diagnosed diabetes should pay close attention to the change of TG/HDL-C, TG, HDL-C and Non-HDL/HDL-C. As for prediabetes participants, the TG/HDL-C, TG and HDL-C level change should be focused.

Early Vs Late Liver Retransplantation: Different Characteristics and Prognostic Factors

BACKGROUND

East Asia is a known endemic area for hepatitis B, and living donor liver transplantation is mainly performed. Liver retransplantation (ReLT) is expected to become an increasing problem because of a shortage of organs. This study aimed to compare early and late ReLT with consideration of specific circumstances and disease background of East Asians.

METHODS

Between October 1996 and January 2015, 51 patients underwent ReLT; we performed a retrospective analysis of data obtained from medical records of the patients. Clinical characteristics, indication, causes of death, survival rate, and prognostic factors were investigated.

RESULT

The survival rate for early ReLT (n = 18) was 51.5% and that for late ReLT (n = 33) was 50.1% at 1 year postoperatively. Continuous venovenous hemodialysis and the use of mechanical ventilators were more frequent, and pre-retransplant intensive care unit stay and prothrombin time was longer in early ReLT than in late ReLT. Operation time was longer and the amount of intraoperative blood loss was greater in late ReLT than in early ReLT. Multivariate analysis showed that a higher C-reactive protein level increased mortality in early ReLT (P = .045), whereas a higher total bilirubin level increased the risk of death in late ReLT (P = .03).

CONCLUSION

Patients with early ReLT are likely to be sicker pre-retransplantation and require adequate treatment of the pretransplant infectious disease. On the other hand, late ReLT is likely to be technically more difficult and should be decided before the total bilirubin level increases substantially.

Diffraction based Hanbury Brown and Twiss interferometry at a hard x-ray free-electron laser

X-ray free-electron lasers (XFELs) provide extremely bright and highly spatially coherent x-ray radiation with femtosecond pulse duration. Currently, they are widely used in biology and material science. Knowledge of the XFEL statistical properties during an experiment may be vitally important for the accurate interpretation of the results. Here, for the first time, we demonstrate Hanbury Brown and Twiss (HBT) interferometry performed in diffraction mode at an XFEL source. It allowed us to determine the XFEL statistical properties directly from the Bragg peaks originating from colloidal crystals. This approach is different from the traditional one when HBT interferometry is performed in the direct beam without a sample. Our analysis has demonstrated nearly full (80%) global spatial coherence of the XFEL pulses and an average pulse duration on the order of ten femtoseconds for the monochromatized beam, which is significantly shorter than expected from the electron bunch measurements.

Femtosecond electron-phonon lock-in by photoemission and x-ray free-electron laser

The interactions that lead to the emergence of superconductivity in iron-based materials remain a subject of debate. It has been suggested that electron-electron correlations enhance electron-phonon coupling in iron selenide (FeSe) and related pnictides, but direct experimental verification has been lacking. Here we show that the electron-phonon coupling strength in FeSe can be quantified by combining two time-domain experiments into a "coherent lock-in" measurement in the terahertz regime. X-ray diffraction tracks the light-induced femtosecond coherent lattice motion at a single phonon frequency, and photoemission monitors the subsequent coherent changes in the electronic band structure. Comparison with theory reveals a strong enhancement of the coupling strength in FeSe owing to correlation effects. Given that the electron-phonon coupling affects superconductivity exponentially, this enhancement highlights the importance of the cooperative interplay between electron-electron and electron-phonon interactions.

Medium optimization for ε-poly-L-lysine production by Streptomyces diastatochromogenes using response surface methodology

Poly-ε-L-lysine is a natural homo-polyamide of L-lysine with excellent antimicrobial properties, which can be used as a novel preservative and has a wide range of applications. In this paper, the fermentation medium for ε-PL production by Streptomyces diastatochromogenes 6#-7 was optimized by Response Surface Methodology. The results of Plackett-Burman design showed that glucose, yeast extract and (NH₄ )₂ SO₄ were the major influencing factors in ε-PL production of S. diastatochromogenes 6#-7. The optimal concentrations of glucose, yeast extract and (NH₄ )₂ SO₄ were determined to be 60, 7·5 and 7·5 g l^-1 according to Box-Behnken experiment and regression analysis, respectively. Under the optimized conditions, the ε-PL yield in shake-flask fermentation was 0·948 ± 0·030 g l^-1 , which was in good agreement with the predicted value of 0·970 g l^-1 . The yield was improved by 43·1% from that with the initial medium. In 5 l jar-fermenter the ε-PL yield reached 25·5 g l^-1 , which was increased by 56·4% from the original medium. In addition, the fermentation time was reduced from 174 to 120 h.

SIGNIFICANCE AND IMPACT OF THE STUDY

Medium optimization is a very practical and valuable tool for fermentation industry to improve product yield and minimize by-products as well as reduce overall manufacturing costs. The response surface methodology is not new, but it is still a very effective method in medium optimization research. This study used ε-polylysine fermentation as an example to demonstrate how the product yield can be significantly increased by medium optimization through surface response methodology. Similar approach can be used in other microbial fermentations such as in pharmaceutical, food, agricultural and energy industries. As an example, ε-polylysine is one of a few newly approved natural food-grade antimicrobials for food and beverages preservations. Yield improvement is economically beneficial to not only ε-polylysine manufacturers but also to their users and consumers due to lower costs and price.

Direct experimental observation of the gas density depression effect using a two-bunch X-ray FEL beam

The experimental observation of the depression effect in gas devices designed for X-ray free-electron lasers (FELs) is reported. The measurements were carried out at the Linac Coherent Light Source using a two-bunch FEL beam at 6.5 keV with 122.5 ns separation passing through an argon gas cell. The relative intensities of the two pulses of the two-bunch beam were measured, after and before the gas cell, from X-ray scattering off thin targets by using fast diodes with sufficient temporal resolution. At a cell pressure of 140 hPa, it was found that the after-to-before ratio of the intensities of the second pulse was about 17% ± 6% higher than that of the first pulse, revealing lower effective attenuation of the gas cell due to heating by the first pulse and subsequent gas density reduction in the beam path. This measurement is important in guiding the design and/or mitigating the adverse effects in gas devices for high-repetition-rate FELs such as the LCLS-II and the European XFEL or other future high-repetition-rate upgrades to existing FEL facilities.

[Correlation analysis of serum secreted frizzled-related protein 5 levels with airway inflammation and insulin resistance in chronic obstructive pulmonary disease patients]

Objective: To investigate the relationship between serum secreted frizzled-related protein 5(sfrp5) levels, insulin resistance, and airway inflammation in patients with chronic obstructive pulmonary disease(COPD). Method: A total of 178 COPD patients visiting our respiratory outpatient clinic from February 2015 to January 2017 were enrolled, and 99 healthy control subjects from the same time period were selected. Serum sfrp5 levels were compared between the 2 groups. Serum sfrp5 and inflammatory cytokines in induced sputum were observed in the 4 subgroups: insulin resistant COPD group [homeostasis model assessment of insulin resistance (HOMA-IR)≥2.29], non-insulin resistant COPD group, non-COPD insulin resistant group, and healthy control group. Results: Serum sfrp5 levels were found to be significantly higher in the COPD group as compared to the healthy control group (t=-14.29, P<0.001). Serum sfrp5 levels in the insulin resistant COPD group [(8±3)ng/ml] were significantly lower than that of the non-insulin resistant COPD group [(10±5)ng/ml], non-COPD insulin resistant group [(13±3)ng/ml], and normal control group [(14±4)ng/ml, F=35.85, P<0.01]. The insulin resistant COPD group had higher levels of In(Homa-IR), as well as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in induced sputum as compared to the non-insulin resistant COPD group, non-COPD insulin resistant group, and healthy control group (F values were 64.968, 41.40, 64.15, respectively, P value <0.01 for all items). The non-insulin resistant COPD group had higher levels of In(HOMA-IR) as well as TNF-α and IL-6 in induced sputum as compared to the non-COPD insulin resistant group and healthy control group. FEV(1)/FVC and FEV(1)% predicted were significantly lower in the insulin resistant COPD group as compared to those of non-insulin resistant COPD group and non-COPD insulin resistant group, and healthy control group (F values were 2.481 and 8.37, respectively, P value<0.05 for all items). FEV(1)/FVC and FEV(1)% predicted were significantly lower in the non-insulin resistant COPD group as compared to those of the healthy control group and non-COPD insulin-resistant group. Serum sfrp5 levels were positively correlated to FEV(1)/FVC and FEV(1) predicted (r values were 0.466 and 0.412, respectively; P values were <0.001 and 0.007, respectively) and inversely correlated to In(HOMA-IR) and TNF-α and IL-6 in induced sputum (r values were -0.304, -0.459, -0.517, respectively; P values were <0.001, 0.002, <0.001, respectively). BMI, ln(HOMA-IR), and IL-6 in induced sputum were independent related factors (r(2) values were 0.286, 0.176, 14.69, respectively; P values were <0.01 for all items) Conclusion: Sfrp5 may be concurrently associated with COPD and insulin resistance; insulin resistance may be associated with airway inflammation and airflow limitation. Sfrp5 may be involved in the development of COPD and may be the key link by which insulin resistance exerts its effects on airway inflammation.