Search

Raman spectroscopy can characterize the rich molecular vibration information of soybean milk powder samples, but difficulties arise in its direct use for sample classification and identification. Therefore, it is urgent to develop an intelligent identification technology based on Raman spectroscopy. For brand identification of soybean milk powder, this work investigates and discusses a variety of spectral processing technologies including wavelet denoising, normalization, principal component analysis, and the results show that appropriate spectral processing can improve the recognition accuracy of the random forest algorithm. Under the optimal conditions (db2 wavelet, normalization, principal component analysis, 30 decision trees), the best recognition effect of soybean milk brand identification can be achieved. The Raman spectral signal acquisition time of each sample is 40 s, and the spectra pretreatment and identification operation time only takes a few minutes. The analytical approach established in this paper has the advantages of convenient and fast Raman spectra acquisition, fast and accurate model identification., Author(s): Zheng-Yong Zhang [sup.1] , Xiao-Jing Shi [sup.1] , Ya-Ju Zhao [sup.2] , Yin-Sheng Zhang [sup.2] , Hai-Yan Wang [sup.2] Author Affiliations: (1) grid.440844.8, 0000 0000 8848 7239, School of [...]

For the conversion of fructose/methylglucoside (MG) into both methyl formate (MF) and methyl levulinate (MLev), the C-source of formate [HCOO]− remains unclear at the molecular level. Herein, reaction mechanisms catalyzed by [CH3OH2]+ in a methanol solution were theoretically investigated at the PBE0/6-311++G(d,p) level. For the conversion of fructose into MF and MLev, the formate [HCOO]− comes from the C1-atom of fructose, in which the rate-determining step lies in the reaction of 5-hydroxymethylfurfural (HMF) with CH3OH to yield MF and MLev. The reaction of fructose with CH3OH kinetically tends to generate HMF intermediates rather than yield (MF + MLev). When MG is dissolved in a methanol solution, its O2, O3, and O4 atoms are closer to the first layer of the solvent than O1, O5, and O6 atoms. For the dehydration of MG with methanol into MF and MLev, the formate [HCOO]− stems from the dominant C1- and secondary C3-atoms of MG. Kinetically, MG is ready to yield (MF + MLev), whereas fructose can induce the reaction to remain at the HMF intermediate, inhibiting the further conversion of HMF with CH3OH into MF and MLev. If MG isomerizes into fructose, the reaction will be more preferable for yielding HMF rather than (MF + MLev). [ABSTRACT FROM AUTHOR]

Introduction: Aristolochic acid contained in Chinese herbs has been proved to be nephrotoxic and carcinogenic. Immunosuppression is associated with an increased risk of developing malignancies. What will be the result if these two significant risk factors are concomitantly present in transplanted patients with aristolochic acid nephropathy (AAN)?, Patients and Methods: A 2-center cohort of 1,612 renal transplant recipients was studied retrospectively from January 1998 to December 2006. We performed an evaluation of the database and review of the charts and pathology reports of these recipients., Results: Kidney transplantations were performed in 17 patients with AAN. Nine (52.9%) of these recipients developed urothelial carcinoma (UC), compared with a 0.46% prevalence of urinary tract tumors among kidney-transplanted patients in China. Eight cases (88.9%) involved the upper urinary tract (bilateral, 3 cases, 37.5%; unilateral, 5 cases, 62.5%). All patients underwent surgical treatment. Six patients (75%) had recurrence during the follow-up period. Three patients died within a mean of 20 months after tumor excision., Conclusions: The risk for UC is distinctly increased in patients with AAN after transplantation. Regular screening for early detection of malignancy is mandatory., (Copyright (c) 2009 S. Karger AG, Basel.)

Objective: To evaluate the effect of HSGJ on chronic allograft nephropathy (CAN) using standard rat model of CAN., Method: Renal transplantation was performed with Fisher rats as donors and Lewis rats as recipients. All the recipients were randomly divided into control group and medication groups (high and low dosage of HSGJ, fed every other day). After 16 weeks of treatment, renal function and the histological alteration of CAN were measured. The expression of the TGFbeta1 mRNA in the allograft was evaluated by real-time PCR., Result: The content of 24 h urine protein and the level of serum creatinine in the medication groups were significantly decreased (P < 0.01) as compared with control group, whereas the creatinine clearance was increased (P < 0.01). The degree of glomerular sclerosis and the Banff score of medication groups were lower than the control group respectively (P < 0.01), in consistent with decreased expression of the TGF 1mRNA., Conclusion: HSGJ can prevent the chronic allograft nephropathy and the mechanism may be related with its influence on the expression of the TGFbeta1.