A sustainable sensitive spectrofluorimetric approach for the determination of the multipotent protein lactoferrin in different pharmaceuticals and infant milk formula: Compliance with greenness metrics

The current study presents the first spectrofluorimetric approach for the estimation of lactoferrin, depending on the measurement of its native fluorescence at 337 nm after excitation at 230 nm, without the need for any hazardous chemicals or reagents. It was found that the fluorescence intensity versus concentration calibration plot was linear over the concentration range of 0.1–10.0 μg/mL with quantitation and detection limits of 0.082 and 0.027 μg/mL, respectively. The method was accordingly validated according to the ICH recommendations. The developed method was applied for the estimation of lactoferrin in different dosage forms, including capsules and sachets with high percent recoveries (97.84–102.53) and low %RSD values (<1.95). Lactoferrin is one of the key nutrients in milk powder and a significant nutritional fortifier. In order to assess the quality of milk powder, it is essential to rapidly and accurately quantify the lactoferrin content of the product. Therefore, the presented study was successfully applied for the selective estimation of lactoferrin in milk powder with acceptable percent recoveries (96.45–104.92) and %RSD values (≤3.607). Finally, the green profile of the method was estimated using two assessment tools: Green Analytical Procedure Index (GAPI) and Analytical GREEnness (AGREE), which demonstrated its excellent greenness.     

The protective effect of breast feeding in relation to sudden infant death syndrome (SIDS): II. The effect of human milk and infant formula preparations on binding of Clostridium perfringens to epithelial cells

Breast feeding is known to protect an infant against gastrointestinal pathogens and epidemiological studies indicate that compared to breast fed infants, formula fed infants are at a greater risk of dying from sudden infant death syndrome (SIDS). Many SIDS infants have symptoms of gastrointestinal infections prior to death and one gastrointestinal pathogen associated with SIDS is Clostridium perfringens. Studies have found that a significantly higher number of formula fed SIDS infants have C perfringens and its enterotoxin in their faeces compared to breast fed infants. The aim of the study was to compare the effects of human milk and infant formula on binding of C perfringens to epithelial cells. Two protocols were used to assess the effect of human milk and infant formula to inhibit binding of C perfringens to epithelial cells. Binding was assessed by flow cytometry. For the in vivo protocol which more closely represents interactions on the mucosal surface, breast milk enhanced bacterial binding but infant formula caused inhibition of binding; however for the in vitro method, both human milk and infant formula resulted in consistent enhancement of binding. Flow cytometry studies indicated that enhancement of binding was due to the formation of bacterial aggregates. Lewis(a) and Lewis(b) antigens, found in both breast milk and infant formula, inhibited C. perfringens binding in a dose dependent manner. The Lewis(a) and Lewis(b) antigens in human milk and infant formula can inhibit C. perfringens binding to epithelial cells. While infant formula reduced binding of C. perfringens to epithelial cells in the experiments carried out with the in vivo protocol, the protective effects of breast feeding in relation to colonisation with C. perfringens are more likely to be due to formation of bacterial aggregates. These findings have implications for improving infant formula preparations.     

Uncertainty calculation in life cycle assessments

Goal and Background  Uncertainty is commonly not taken into account in LCA studies, which downgrades their usability for decision support. One often stated reason is a lack of method. The aim of this paper is to develop a method for calculating the uncertainty propagation in LCAs in a fast and reliable manner. Approach  The method is developed in a model that reflects the calculation of an LCA. For calculating the uncertainty, the model combines approximation formulas and Monte Carlo Simulation. It is based on virtual data that distinguishes true values and random errors or uncertainty, and that hence allows one to compare the performance of error propagation formulas and simulation results. The model is developed for a linear chain of processes, but extensions for covering also branched and looped product systems are made and described. Results  The paper proposes a combined use of approximation formulas and Monte Carlo simulation for calculating uncertainty in LCAs, developed primarily for the sequential approach. During the calculation, a parameter observation controls the performance of the approximation formulas. Quantitative threshold values are given in the paper. The combination thus transcends drawbacks of simulation and approximation. Conclusions and Outlook  The uncertainty question is a true jigsaw puzzle for LCAs and the method presented in this paper may serve as one piece in solving it. It may thus foster a sound use of uncertainty assessment in LCAs. Analysing a proper management of the input uncertainty, taking into account suitable sampling and estimation techniques; using the approach for real case studies, implementing it in LCA software for automatically applying the proposed combined uncertainty model and, on the other hand, investigating about how people do decide, and should decide, when their decision relies on explicitly uncertain LCA outcomes-these all are neighbouring puzzle pieces inviting to further work.     

Quantification of Bifidobacterium spp., Escherichia coli and Clostridium difficile in faecal samples of breast-fed and formula-fed infants by real-time PCR

To determine the influence of either exclusive breast-feeding or formula feeding on both composition and quantity of the gut microbiota in infants, we have developed real-time, quantitative PCR assays for the detection of Bifidobacterium spp. and Clostridium difficile. Furthermore, we have monitored the prevalence and counts of Escherichia coli by applying a previously described real-time PCR assay. We found all 100 infants tested to be colonized by Bifidobacterium spp. The bifidobacterial counts were comparable between the 50 breast-fed and 50 formula-fed infants with median values of 10.56 log10 and 10.24 log10 CFU g(-1) wet weight faeces, respectively. C. difficile was detected in 14% of the breast-fed and 30% of the formula-fed infants. In addition, the C. difficile counts were significantly lower in breast-fed infants than in the formula-fed group (median values of 3.28 log10 and 7.43 log10 CFU g(-1), respectively; p=0.03). The prevalence of E. coli in the breast-fed and formula-fed group was 80% and 94%, respectively. Also, the E. coli counts in colonized infants was significantly lower in the breast-fed infants than in the formula-fed group (median values of 9.11 log10 and 9.57 log10 CFU g(-1), respectively; p=0.004). We conclude that the prevalence and counts of C. difficile as well as E. coli are significantly lower in the gut microbiota of breast-fed infants than in that of formula-fed infants, whereas the prevalence and counts of Bifidobacterium spp. is similar among both groups.     

生物反应器填埋场的试验研究

In this study, a methane bioreactor-landfill system was utilized to treat municipal solid waste (MSW). Through analyzing and detecting the pollutant(CODcr) in the bioreactor-landfill system, a simulated mathematic formulaof waste degradation was established. After treated with this system, the CODcr and VFA concentrations in MSW could be decreased from more than 20000 and 7000 mg·L^-1 to less than 1500 and 200 mg·L^-1, respec-tively.     

江豚鳍肢骨骼形态特征的观察

江豚Neophocaena phocaenoides鳍肢的基本结构与海洋豚类相同,但又有其特殊性。为完善江豚鳍肢骨骼形态特征的研究,本文通过运用原位解剖、制作透明鳍肢骨骼以及X光拍照的方法,对威海海域四头江豚的鳍肢骨骼进行了较全面、较系统地观察和测量,对每一块骨骼的名称、位置、形状、大小做了详细描述,并分析了没有中央腕骨和腕骨1的原因,这些在以往的研究中还未见报道。标本具有不同的年龄和性别,采集的时间和地点也不同,因此,本结果带有一定的普遍性。与以往研究鳍肢骨骼的方法相比,制作透明鳍肢骨骼具有直观、完整、清晰、美观、准确、易于观察等特点,辅以X光照片观察得出与以往研究的结果有很大差别,如国内外学者原来记述腕骨的形态为5块相连成一平坦的椭圆形盘状;指式总结为:Ⅰ2-3,Ⅱ5-9,Ⅲ5-8,Ⅳ3-4,Ⅴ2-3。而作者记述为在整体上,腕骨与包围它们自身的软骨共同连成一平坦的不规则多角形;指式为:Ⅰ0-1,Ⅱ6,Ⅲ5,Ⅳ2,Ⅴ0(掌骨不计)。据分析,造成这些差异的主要原因之一是研究方法的不同。       

Maximum likelihood estimation of neutral model parameters for multiple samples with different degrees of dispersal limitation

In a recent paper, I presented a sampling formula for species abundances from multiple samples according to the prevailing neutral model of biodiversity, but practical implementation for parameter estimation was only possible when these samples were from local communities that were assumed to be equally dispersal limited. Here I show how the same sampling formula can also be used to estimate model parameters using maximum likelihood when the samples have different degrees of dispersal limitation. Moreover, it performs better than other, approximate, parameter estimation approaches. I also show how to calculate errors in the parameter estimates, which has so far been largely ignored in the development of and debate on neutral theory.     

On the two-locus sampling distribution

Two methods are discussed for evaluating the distribution of the configuration of unlabeled gametic types in a random sample of size n from the two-locus infinitely-many-neutral-alleles diffusion model at stationarity. Both involve finding systems of linear equations satisfied by the desired probabilities. The first approach, which is due to Golding, is to include additional probabilities in the system that allow some members of the sample to be specified at only one locus. The second approach, which is new, considers the joint distribution of the sample configuration and the number of recombination events since the time of the most recent common ancestor. The first approach is used for numerical computation, whereas the second approach is used to derive a two-locus version of Hoppe's urn model. The latter permits efficient simulation of the two-locus sampling distribution, provided the recombination parameter is not too large.Supported in part by NSF grants DMS-8704369 and DMS-8902991     

On the Convergence of an Algorithm of Jones

Pearce (1976) proposed the use of the variance matrix for design block experiments. Jones (1976) gave an iterative formula for, but stated that the iteration failed to converge for some block designs. We derive necessary and sufficient conditions for the convergence of JONES' iteration. We also note that a simple modification to JONES' iteration will ensure its convergence.