Validation of the children international IgA nephropathy prediction tool based on data in Southwest China

BackgroundImmunoglobulin A nephropathy (IgAN) is one of the most common kidney diseases leading to renal injury. Of pediatric cases, 25%–30% progress into end-stage kidney disease (ESKD) in 20–25 years. Therefore, predicting and intervening in IgAN at an early stage is crucial. The purpose of this study was to validate the availability of an international predictive tool for childhood IgAN in a cohort of children with IgAN treated at a regional medical centre.MethodsAn external validation cohort of children with IgAN from medical centers in Southwest China was formed to validate the predictive performance of the two full models with and without race differences by comparing four measures: area under the curve (AUC), the regression coefficient of linear prediction (PI), survival analysis curves for different risk groups, and R2D.ResultsA total of 210 Chinese children, including 129 males, with an overall mean age of 9.43 ± 2.71 years, were incorporated from this regional medical center. In total, 11.43% (24/210) of patients achieved an outcome with a GFR decrease of more than 30% or reached ESKD. The AUC of the full model with race was 0.685 (95% CI: 0.570–0.800) and the AUC of the full model without race was 0.640 (95% CI: 0.517–0.764). The PI of the full model with race and without race was 0.816 (SE = 0.006, P < 0.001) and 0.751 (SE = 0.005, P < 0.001), respectively. The results of the survival curve analysis suggested the two models could not well distinguish between the low-risk and high-risk groups (P = 0.359 and P = 0.452), respectively, no matter the race difference. The evaluation of model fit for the full model with race was 66.5% and without race was 56.2%.ConclusionsThe international IgAN prediction tool has risk factors chosen based on adult data, and the validation cohort did not fully align with the derivation cohort in terms of demographic characteristics, clinical baseline levels, and pathological presentation, so the tool may not be highly applicable to children. We need to build IgAN prediction models that are more applicable to Chinese children based on their particular data

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Revegetation in the water level fluctuation zone of a reservoir: An ideal measure to reduce the input of nutrients and sediment

The Three Gorges Dam (TGD) is one of the largest dams in the world. Due to the management of the Three Gorges Reservoir (TGR), a huge water level fluctuation (WLF) zone was formed and this caused significant changes to the vegetation in this area. A local vegetation survey was conducted in the WLF zone of the Xiangxi River, one of the major tributaries of the Three Gorges Reservoir, from 2010 to 2011. Based on the survey results, a revegetation method using Cynodon dactylon was established. C. dactylon can survive after very long periods of submergence, and using local species to restore vegetation can prevent the introduction of invasive species. After long-term growth and propagation, the vegetation in our experimental plots was restored, resulting in beneficial landscape and ecology effects. According to our in situ experiments, revegetation in the WLF zone significantly reduced the flow of nutrients and sediments into the TGR. Furthermore, the C. dactylon plots produced less biomass than did the control plots, meaning that less organic matter was introduced to the water. In conclusion, C. dactylon is a suitable candidate for use in the revegetation of the WLF zone of the TGR, and revegetation of the WLF zone will be beneficial in the maintenance of water quality of the TGR. (C) 2014 Elsevier B.V. All rights reserved

Absorbable Organic Halide (AOX) Reduction in Elemental Chlorine-Free (ECF) Bleaching of Bagasse Pulp from the Addition of Sodium Sulphide

A laboratory investigation was developed to confirm and to quantify the reductions in absorbable organic halide (AOX) discharge when sodium sulphide was added during elemental chlorine-free (ECF) bleaching of sugarcane bagasse pulp. After the chlorine dioxide bleaching stage, the pulp was sent directly into the extraction stage without washing. FTIR was employed to determine the breakage of chemical bonds in the pulp, and GC-MS was used to measure the composition of the bleaching effluent. The addition of sodium sulphide caused a reduction in AOX of up to 46.7%. The AOX reduction reached this maximum when the sodium sulphide was added 30 min after the start of the extraction stage and when the pH was higher than 12. FTIR spectroscopy showed that the phenolic lignin of the pulp was degraded by the sodium sulphide and that the syringyl lignin and C-O-C, C=O structure of the pulp holocellulose of the pulp was preserved during the extraction stage. The GC-MS showed that the chlorobenzene and chlorophenol contents decreased noticeably after the addition of sodium sulphide

Regulating Nutrients and Phytoplankton by Extending the Habitats of Periphyton in a Deep River-Type Reservoir

Eutrophication and phytoplankton blooms threaten the water quality of many reservoirs, especially deep ones. Periphyton is an important component of aquatic ecosystems that can compete with phytoplankton for light and nutrients. However, studies on the dynamics of periphyton development in deep reservoirs are rare. Here, the growth characteristics of periphyton on the artificial substrate (AS) in both open water and enclosures of the Three Gorges Reservoir (TGR) are investigated. The development and relative importance of periphyton are analyzed. The results indicate that mass growth of periphyton is observed on the AS platforms after several weeks. A potential phosphorus limitation for periphyton development in the TGR is evidenced by the relatively high TN/TP ratio in the water column. The differences of phytoplankton biomass in two enclosures suggest the existence of interactions between phytoplankton and periphyton. The results indicate that the artificially loaded AS on the water surface of the deep reservoir leads to the redistribution of nutrients and light between phytoplankton and periphyton. The results are very encouraging because the use of AS for periphyton incubation is an economical and practical way to reduce the probability of phytoplankton blooms in deep reservoirs, especially when the nutrient loads cannot be reduced effectively in a short period

Enzyme and Alkali-Aided ECF Bleaching of Kraft Bamboo Pulp

Unbleached kraft bamboo pulp was pretreated by a xylanase and laccase (X/L) treatment, as well as a joint treatment of X/L and alkali, prior to element chlorine free (ECF) bleaching. In comparison with the control test, the joint treatment of X/L and alkali (X/L+0.1%) had more potential to reduce absorbable organic halide (AOX) levels (29.79%) and COD content (21.55%), in addition to improving bleached pulp properties (56.88% decrease in kappa number and 8.94 %ISO increased in brightness). Moreover, the treatment of X/L+0.1% removed more lignin and HexA than X/L treatment. The analysis of XPS indicated that the X/L treatment could noticeably remove the surface lignin of pulp, but the joint treatments of X/L and alkali could promote the production of superficial lignin. FTIR results showed that pretreatments only reduced part of the lignin and carbohydrate contents, but did not change their structures. The joint pretreatment of enzymes and diluted alkali (X/L+0.1%) had more appealing advantages to produce bleached kraft bamboo pulp

Optimization of Laccase-Aided Chlorine Dioxide Bleaching of Bagasse Pulp

The laccase-mediator system in laccase-aided chlorine dioxide bleaching of bagasse pulp was optimized using response surface methodology (RSM). The effects and interactions of the laccase enzyme dosage, the dosage of the mediator 1-hydroxybenzotriazole (HBT), and the reaction time on the adsorbed organic halogen (AOX) content of the wastewater as well as the brightness and kappa number of the pulp were examined. The optimal reaction conditions to achieve a balance of lower AOX content, higher brightness, and lower kappa number were as follows: laccase enzyme dosage of 20.3 U/g, HBT dosage of 1.51%, and reaction time of 154.5 min. Under these conditions, an AOX content of 20.67 mg/L, brightness of 58.94% ISO, and kappa number of 2.71 were observed. These results will offer a favorable option for pulp and paper mills as well as the natural environment and therefore provide a theoretical foundation for the industrial application of laccase in bleaching processes

Optimum Conditions for the Removal of Cr(VI) using Modified Eucalyptus Bark

The aims of this study were response surface modeling and optimization of Cr(VI) removal from solution using formaldehyde-modified eucalyptus bark. A high removal rate of Cr(VI) was achieved under the conditions of low adsorbent dosing quantity and high initial concentration of Cr(VI). Analysis of variance showed a high multiple coefficient of determination (R2=0.9875), adjusted determination coefficient (R2Adj=0.9714), and the good second order regression equation. The initial concentration of Cr(VI) was 40.15 mg/L, adsorbent dosing quantity 3.40 g/L, and initial reaction pH 2.78, and the largest removal rate was 99.998% under the optimum reaction conditions. Langmuir and Freundlich isothermal models described well adsorption of Cr(VI) by the modified stringy bark. Adsorption kinetics studies showed that the adsorption was controlled by multiple factors, dominated by chemical adsorption. The adsorption was found to be spontaneous and endothermic, with △G0 0, and △S0 > 0. Adsorption of Cr(VI) by formaldehyde-modified stringy bark was partly controlled by REDOX reactions. The adsorbents were characterized by SEM and FTIR

Effects of Additives on Absorbable Organic Halide Reduction in Elemental Chlorine-Free Bleaching of Bagasse Kraft Pulp

In order to further reduce absorbable organic halide (AOX) formation in the bleaching effluent, NH2SO3H and DMSO were added during the elemental chlorine-free (ECF) bleaching (D0EpD1) of bagasse kraft pulp. In the D0 stage, AOX formation decreased by 10% with 0.1% NH2SO3H, and a reduction of 11.2% with 1.0% DMSO, respectively. Ultraviolet (UV) spectra, Fourier transform infrared spectroscopy (FTIR), and gas chromatography-mass spectroscopy (GC-MS) were adopted in characterizing changes of lignin degradation and the main functional groups of bleached pulp. The UV spectrum showed that the quantity of polyphenols decreased after adding the additives. The FTIR spectrum showed that both the content of phenolic-type lignin and the degradation degree of lilac-type lignin decreased after adding NH2SO3H. If was found that DMSO was beneficial in retaining C-O-C and C=O structures in cellulose and hemicellulose, while NH2SO3H decreased the content of β-glycosidic bonds and C-O-C structures in cellulose and hemicellulose. The composition of lignin degradation products in the bleaching effluent was analyzed by GC-MS. The contents of chlorobenzene and chlorophenol decreased notably when additives were added. Compared with DMSO, NH2SO3H exhibited poor inhibition on the formation of some phenols

Xylanase-Aided Chlorine Dioxide Bleaching of Bagasse Pulp to Reduce AOX Formation

Xylanase pretreatment was used to improve the chlorine dioxide bleaching of bagasse pulp. The pulp was pretreated with xylanase, which was followed by a chlorine dioxide bleaching stage. The HexA content of the pulp and the AOX content of the bleaching effluent were measured using UV-Vis and GC-MS methods, respectively. The results showed that a good correlation occurred between HexA and kappa number. HexA content of the pulp decreased significantly after the xylanase pretreatment. The AOX content of the bleaching effluent decreased as HexA was removed from the pulp. It was found that AOX could be reduced by up to 29.8%, comparing XD0 with a D0 stage. Fourier transform infrared spectroscopy (FTIR) was employed to determine the breakage of chemical bonds in the pulp. It revealed that some lignin and hemicellulose were removed after xylanase treatment. The GC-MS results showed that some toxic chloride such as 2,4,6-trichlorophenol could be completely removed after xylanase pretreatment