Effects of predator movement patterns on the biofouling layer during gravity-driven membrane filtration in treating surface water

Biological predation has a significant effect on biofouling layers in gravity-driven membrane (GDM) filtration systems. However, the detailed process of predatory activities is still not well known. This study explored the effects of predator movement patterns on the biofouling layer at different temperatures and the factors affecting the stable flux level. The results indicated that Demospongiae, Spirotrichea and Saccharomycetes were the main species, with the body contracting or rotating in one position at 5 °C, and Litostomatea accounted for 55.1% at 10 °C. The weak agility of these species resulted in a less porous biofouling layer with a high extracellular polymeric substance (EPS) concentration, which was responsible for the low permeate flux and the time to reach flux stability. Bdelloidea was dominant at 20 and 30 °C, and the more heterogeneous biofouling layer with a lower EPS concentration was related to their intense creeping and swimming movements and their ability to create current in the water. The grazing of spongy flocs by predators affected the GDM system performance, and a high stable flux was obtained with large and loose flocs. In addition, the diversity of the eukaryotic community decreased after the flux stabilized due to the particular predominance of Bdelloidea at high temperatures, corresponding to a high stable flux. Pollutant removal was less affected by eukaryotes, and decreased ammonia nitrogen removal rates were related to the lower activity of nitrifying bacteria. Moreover, the reliable linear correlation between the temperature and the stable flux implied that the stable flux could be well predicted in the GDM system. The findings are beneficial for developing new strategies for regulating flocs and the biofouling layer to improve the performance of GDM systems.

[Clinical efficacy and safety analysis of camrelizumab combined with apatinib as a second-line therapy for unresectable hepatocellular carcinoma: a multicenter retrospective study]

Objective: To analyze the clinical efficacy and safety of camrelizumab combined with apatinib as a second-line therapy for unresectable hepatocellular carcinoma (HCC). Methods: Ninety-four cases with mid-and advanced-stage HCC who received camrelizumab combined with apatinib as second-line treatment were enrolled. Routine blood test, blood biochemical indexes, tumor stage, tumor imaging characteristics, previous treatment strategies and other clinical data before treatment were documented. Imaging examination follow-up results and adverse reactions during treatment were followed up until the end of follow-up or loss of follow-up or death. Kaplan-Meier method was used to analyze the clinical efficacy. Results: As of the last follow-up, 94 cases with mid-and advanced-stage HCC had received camrelizumab combined with apatinib as second-line treatment. Among them, 15 cases were lost to follow-up, 31 cases died, and 48 cases survived. The overall remission rate was 31.9%. The overall disease control rate was 71.3%. The median time to disease-free progression was 6.6 months. The median time to disease progression was not yet available. The 1-year cumulative survival rate was 62.3%. Grade 3 and above adverse reactions mainly included were thrombocytopenia (7.4%), abdominal pain (4.3%), active hepatitis (4.3%), leukopenia (4.3%), diarrhea (3.2%), hand-foot syndrome (3.2%). All adverse reactions were effectively controlled. Conclusion: Camrelizumab combined with apatinib can effectively prolong the survival period of patients with mid-and advanced-stage HCC, and it is well tolerated.

Doppler-based predictive model for methotrexate resistance in low-risk gestational trophoblastic neoplasia with myometrial invasion: prospective study of 147 patients

OBJECTIVES

This prospective clinical study aimed to evaluate the vascularization characteristics of low-risk gestational trophoblastic neoplasia (GTN) using Doppler imaging and to develop a predictive model for resistance to methotrexate (MTX).

METHODS

Patients with low-risk GTN receiving primary MTX treatment were enrolled from the Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China, from September 2012 to August 2018. The primary endpoint was to develop and internally validate a predictive model for resistance to MTX therapy in these patients. In the training set, clinical features and Doppler hemodynamic parameters before MTX therapy were analyzed using logistic regression to identify independent predictors of MTX resistance, which were integrated into the model. The predictive performance of the model was evaluated by leave-one-out cross-validation in the training dataset and internal validation in an independent-sample test dataset.

RESULTS

The entire imaging protocol was completed by 147 eligible patients, of which 110 comprised the training set and 37 the test set. In the training set, cases with myometrial invasion (81.8%; 90/110) showed vascular-enriched areas in the myometrium and high velocity and low impedance ratios of the uterine artery (UtA) compared to cases without myometrial invasion (18.2%; 20/110). On multivariate logistic regression analysis, time-averaged mean velocity in UtA (UtA-TAmean) and the International Federation of Gynecology and Obstetrics (FIGO) score were identified as independent predictors (P = 0.009 and P = 0.043, respectively) of MTX resistance. The Doppler-based predictive model, developed based on the 90 cases with myometrial invasion, was y = -2.95332 + 0.41696 × FIGO score + 0.03551 × UtA-TAmean. The model showed an area under the curve of 0.757 (95% CI, 0.653-0.862) and the optimal cut-off value was 0.50622, which had 45.2% sensitivity and 96.6% specificity. The model stratified patients with low-risk GTN into low (< 10%), intermediate (10-90%) and high (> 90%) probability of MTX resistance, based on the threshold values of -1.59544 and 0.10046. The model had an accuracy of 74.4% (95% CI, 64.5-82.3%) in the cross-validation and 72.7% (95% CI, 55.8-84.9%) in the internal validation.

CONCLUSIONS

The Doppler-based predictive model, combining a non-invasive marker of tumor vascularity with the FIGO scoring system, can differentiate cases with low from those with high probability of developing MTX resistance and therefore has the potential to guide treatment options in patients with low-risk GTN and myometrial invasion. © 2020 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Summary of 3rd Sino-German symposium on fundamentals of advanced nuclear safety technology

The 3rd "Sino-German Symposium on Fundamentals of Advanced Nuclear Safety Technology (SG-FANS)" took place in Xi’an, China, in 2019. Common fields of interests have been identified on both Chinese and German side, such as code benchmarking, common access to experimental facilities and joint experimental data base for nuclear safety analyses.

[The relationship between resting heart rate and all-cause mortality among the Chinese oldest-old aged more than 80: a prospective cohort study]

Objective: To explore the association between resting heart rate(RHR) and all-cause mortality among the Chinese oldest-old aged more than 80. Methods: Using a total of seven surveys or follow-ups data (1998, 2000, 2002, 2005, 2008, 2011 and 2014) from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 17 886 elderly over 80 years old were selected as subjects, their resting heart rate were measured though baseline survey and the survival outcome and death time of the subjects were followed up. The subjects were divided into 6 groups according to their resting heart rate. Cox regression model was used to estimate the effect of resting heart rate on mortality risk. The interaction of age, gender and resting heart rate was also analyzed by likelihood ratio test. Results: The age of subjects M (P₂₅, P₇₅) was 92 (86, 100) years old, including 10 531 females (58.9%) and there were 13 598 participants died, the mortality rate was 195.5 per 1 000 person-years. Multivariate Cox regression analysis showed that compared to the control group (60-69 pbm/min), the hazard ratio of the elderly are 1.06 (95%CI: 1.02, 1.11), 1.09 (95%CI: 1.04, 1.15), 1.23 (95%CI: 1.14, 1.34), 1.25 (95%CI: 1.08, 1.44) in the group of RHR between 70-79, 80-89, 90-99 and ≥100 pbm/min and P values are all less than 0.05. Likelihood ratio test showed that RHR and age had an interaction effect. (P for interaction=0.011). Conclusion: The risk of all-cause death increased with the increase of resting heart rate and this relationship was stronger between the 80-89 years old people.

BMI modifies the association between serum HDL cholesterol and stroke in a hypertensive population without atrial fibrillation

PURPOSE

Both high-density lipoprotein cholesterol (HDL-C) and body mass index (BMI) have an impact on the prevalence of stroke. However, it is unclear whether BMI can modify the relationship between HDL-C and stroke. Therefore, we aimed to assess the effect of the BMI on the association between HDL-C and stroke in a hypertensive population without atrial fibrillation (AF).

METHODS

We analyzed data of 10,925 hypertensive patients without AF from the Chinese Hypertension Registry Study. BMI was categorized as < 24 and ≥ 24 kg/m². Multivariate logistic regression and smooth curve fitting (penalized spline method) were used to analyze the association between HDL-C and stroke in different BMI groups. Subgroup analysis and interaction tests were used to explore the effect of other variables on this relationship.

RESULTS

The results showed a negative association between HDL-C and stroke in the BMI < 24 kg/m² group, but HDL-C was not associated with stroke in the BMI ≥ 24 kg/m² group. In the BMI < 24 kg/m² group, each 1 mmol/L increase in HDL-C was associated with a 50% decreased risk of stroke [odds ratio (OR) 0.50, 95% confidence interval (CI) 0.38-0.66]. No significant relationship between HDL-C and stroke was observed in the BMI ≥ 24 kg/m² group (OR 0.73, 95% CI 0.49-1.10). There was a significant interaction between BMI and HDL-C in regard to the prevalence of stroke in the hypertensive population without AF (P_Interaction = 0.027).

CONCLUSIONS

We found an inverse association between HDL-C and stroke only in the BMI < 24 kg/m² group. The finding suggested that BMI could modify the association between HDL-C and stroke in hypertensive populations without AF.

[Effect of tissue inhibitor of metalloproteinase-1 and 2 siRNA on the expression of smad2/3/4 protein in hepatic stellate cells]

Objective: To study the effect of tissue inhibitor of metalloproteinases (TIMP)-1 siRNA and TIMP-2 siRNA on the expression of smad2/3/4 protein in CCl4-induced liver fibrosis rat hepatic stellate cells (HSC). Methods: Rat's liver tissues with liver fibrosis after treatment with pre-built TIMP-1siRNA and TIMP-2 siRNA were used as the research subjects. Immunohistochemistry, Western blotting and real-time PCR were used to detect the protein and corresponding mRNA expression levels on smad2/3/4. TUNEL and α-smooth muscle actin (α-SMA) positive cells were quantified by double-labeled immunofluorescence. Analysis of variance (ANOVA) was used to compare the means between multiple groups, and the SNK test was used for the pairwise comparison of means. Results: The results of immunohistochemistry showed that the protein expressions of smad2, smad3, and smad4 in the TIMP-1 siRNA group and TIMP-2 siRNA group were significantly reduced than those of the model and the negative control group (P < 0.05). In addition, Western blotting results had also shown the same trend. The protein expression of smad2, smad3, and smad4 in the TIMP-1siRNA group and TIMP-2siRNA group were significantly reduced than those of the model and the negative control group (P < 0.01). The mRNA expression of smad2, smad3, and smad4 in TIMP-1siRNA group and TIMP-2siRNA group was significantly reduced than those of the model and negative control group (P < 0.05). Immunofluorescence showed that the apoptosis of activated HSC in the TIMP-1 siRNA group(0.014 3 ± 0.002 4) and TIMP-2 siRNA group(0.010 7 ± 0.004 4) was increased than those of the model(0) and the negative control group (0.002 4 ± 0.002 4, P < 0.05). Conclusion: TIMP-1 siRNA and TIMP-2 siRNA promote the apoptosis of activated HSCs. In addition, it also has a significant inhibitory effect on the expression of smad protein.

Same pandemic but different studies: an exploration of COVID-19 research at the early stage

OBJECTIVE

Scientific research is an essential necessity for the prevention and control of COVID-19. Accelerated paper-sharing makes it possible to explore the responses of scientific communities of different countries and their research focus. This is achieved by examining relevant publications during the early stage of the pandemic. This paper explores a timely research assessment on COVID-19 among China, USA, and EU.

MATERIALS AND METHODS

Papers indexed in PubMed and published from December 30, 2019, to March 11, 2020, were selected. Papers from China, USA, and EU were assessed by calculating the significance of items in the co-occurrence exported from VOSviewer.

RESULTS

The results showed that Chinese studies focus more on clinical manifestations, while USA and EU focus on experimental research. Furthermore, US research is more geared toward detection techniques and mathematical models, China focuses more on monitoring the epidemic situation, and EU engages in both.

CONCLUSIONS

This paper argues that the above distinctions are caused by differences in the stages of epidemic development, researchers' experience bases for formulating measures, traditions within the different medical cultures, and the distinction between "information" and "knowledge".

Expression, purification and characterization of three odorant binding proteins from the diamondback moth, Plutella xylostella

Odorant binding proteins (OBPs) are critical components in insect olfactory systems where they bind, solubilize and transport odorant molecules to receptors. Here, we cloned three OBPs (PxylGOBP1, PxylGOBP2 and PxylOBP24) from the diamondback moth, Plutella xylostella, one of the most destructive pests of cruciferous crops. These three OBPs were expressed in Escherichia coli as recombinant proteins, purified and characterized by fluorescence binding assays with 39 ligands including sex pheromone and plant-derived chemical compounds. PxylGOBP1 and PxylGOBP2 showed significantly different binding affinities to theses ligands, suggesting distinct binding preferences of these two general odorant binding proteins. PxylOBP24 showed no or extremely low binding activities to selected ligands, suggesting it may be involved in non-olfactory functions. Circular dichroism spectral results demonstrated that PxylGOBP1 and PxylGOBP2 shared similar secondary structures while PxylOBP24 was significantly different. This study improves our knowledge of insect OBPs, which will assist in a better understanding of insect olfactory system and developing more environmentally friendly pest control strategies for P. xylostella.

Biotransformation of insecticide flonicamid by Aminobacter sp. CGMCC 1.17253 via nitrile hydratase catalysed hydration pathway

AIMS

This study evaluates flonicamid biotransformation ability of Aminobacter sp. CGMCC 1.17253 and the enzyme catalytic mechanism involved.

METHODS AND RESULTS

Flonicamid transformed by resting cells of Aminobacter sp. CGMCC 1.17253 was carried out. Aminobacter sp. CGMCC 1.17253 converts flonicamid into N-(4-trifluoromethylnicotinoyl) glycinamide (TFNG-AM). Aminobacter sp. CGMCC 1.17253 transforms 31·1% of the flonicamid in a 200 mg l^-1 conversion solution in 96 h. Aminobacter sp. CGMCC 1.17253 was inoculated in soil, and 72·1% of flonicamid with a concentration of 0·21 μmol g^-1 was transformed in 9 days. The recombinant Escherichia coli expressing Aminobacter sp. CGMCC 1.17253 nitrile hydratase (NHase) and purified NHase were tested for the flonicamid transformation ability, both of them acquired the ability to transform flonicamid into TFNG-AM.

CONCLUSIONS

Aminobacter sp. CGMCC 1.17253 transforms flonicamid into TFNG-AM via hydration pathway mediated by cobalt-containing NHase.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report that bacteria of genus Aminobacter has flonicamid-transforming ability. This study enhances our understanding of flonicamid-degrading mechanism. Aminobacter sp. CGMCC 1.17253 has the potential for bioremediation of flonicamid pollution.

Effect of the baseline pulse wave velocity on short term and long term blood pressure control in primary hypertension

OBJECTIVES

Arterial stiffness may affect antihypertensive response to antihypertensive treatment. However, sufficient clinical evidence is lacking. This longitudinal study aimed to evaluate the effect of baseline arterial stiffness measured by the brachial-ankle pulse wave velocity (baPWV) on response to short-term and long-term enalapril-based treatment in 3310 hypertensive adults from the China Stroke Primary Prevention Trial (CSPPT).

METHODS AND RESULTS

Blood pressure (BP) measured at three months (short-term) in 2780 subjects, and the time-average on-treatment BP in 3310 subjects during a median of 4.5-year follow-ups (long-term) were analyzed in the study. After short-term antihypertensive treatment, every 1 m/s increase in baPWV denoted a 7% and 6% decreased chance of achieving systolic BP (SBP) control (odds ratio (OR), 0.93; 95% CI 0.90, 0.96; P < 0.001) and BP control (OR, 0.94; 95% CI 0.91, 0.97; P < 0.001), respectively, after adjustment for age, gender and other variables. After long-term treatment, every 1 m/s increase in baPWV posed an 7% and 6% greater risk of failing to attain SBP control (OR, 0.93; 95% CI 0.90, 0.95; P < 0.001) and BP control (OR, 0.94; 95% CI, 0.92, 0.96; P < 0.001), respectively, not regarding for DBP control after both short- and long-term treatment. Higher baseline baPWV significantly decreased SBP reduction both after three months and the median 4.5-year treatment, while increased DBP reduction after the median 4.5-year treatment.

CONCLUSIONS

Elevated baseline baPWV significantly decreased BP response to short-and long-term treatment in adults with primary hypertensive. Arterial stiffness improvement may be an essential target to achieve adequate BP control.

Ferrous-activated sodium percarbonate pre-oxidation for membrane fouling control during ultrafiltration of algae-laden water

Membrane technology has been shown to be promising for the treatment of algae-laden water, but membrane fouling is still an obstacle influencing the purification efficiency and effluent quality. To mitigate ultrafiltration membrane fouling during Microcystis aeruginosa-laden water treatment, a strategy of sodium percarbonate pre-oxidation activated with ferrous ion (Fe²⁺/SPC) was put forward in this study. Due to the synergistic effect of Fe²⁺ and SPC, this process was significantly more efficient with the terminal specific flux increased from 0.097 to 0.397, and the reversible fouling resistance reduced by approximately 80%. It was also found that subsequent sedimentation followed by Fe²⁺/SPC could further improve the fouling control efficiency. The model fitting results indicated that Fe²⁺/SPC pre-oxidation delayed the transition from standard blocking to cake filtration. Extracellular organic matter and algal cells were extracted from algal foulants to explore the contribution of each component, and the fouling control efficiencies were systematically studied. The characteristics of the algal foulants were determined with fluorescence excitation-emission matrix spectrum, and the results suggested that macromolecular proteinaceous substances were more efficiently removed by Fe²⁺/SPC, in comparison with humic-like matters. The alleviation of membrane fouling was also verified by the characterization methods of scanning electron microscopy and attenuated total reflection-Fourier infrared spectroscopy. Overall, the proposed strategy of Fe²⁺/SPC has an application prospect for membrane fouling control in algal-laden water treatment.