A novel approach for quantitative peptides analysis by selected electron transfer reaction monitoring

Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with selective reaction monitoring (SRM) is a selective and sensitive method for quantitation of peptides. SRM is achieved via MS/MS utilizing collision-induced dissociation (CID) while monitoring unique precursor-product ion transitions. Low-energy CID tandem mass spectrometry has been, by far, the most common method used to dissociate peptide ions for sequence analysis. However, collisional scattering of product ions in CID results in decreased intensity of the primary production. The lower intensity of the targeted product ion can lead to a reduction in the sensitivity of a quantitative method that uses SRM. Electron transfer dissociation (ETD) is a fragmentation method that is complementary to CID. During the ETD reaction for doubly protonated peptides ([M+2H](2+)), there is a significant shift toward nondissociative electron transfer (ET) product species ([M+2H](+center dot)). We utilized that particular defect in ETD to develop a new quantitative method for monitoring the transition of unique precursors ([M+2H](2+)) to charge-reduced ions ([M+2H](+center dot)). We refer to this method as selective electron transfer reaction monitoring (SETRM). In ESI-MS, trypsin-digested peptides tend to generate doubly protonated peptide precursors. We found that SETRM was more suitable than SRM for these doubly charged tryptic peptides with nano-LC-MS/MS. The quantitative capabilities of SETRM provide a more sensitive way of performing quantitative experiments using the same instrument, thereby improving the application of electron transfer dissociation in proteomics. (c) 2010 Elsevier B.V. All rights reserved

Increasing Yield; of the Second Crop Rice with Improvement of Fertilizer Efficiency and Sail Nitrogen Fertility

USG深施提高氮素回收率及稻谷產量之效果，以一期稻優於二期稻，一期稻谷增產量可達13%，氮回收率最高可達77%；二期稻谷增產量最高僅有3%（屏東新埤），而氮回收率最高亦只有41%。 二期作USG深施在含有膨脹性粘土礦物之臺中土壤其稻谷增產量最高可達18%，氮肥同收率在30%～71%之間，皆優於不含膨脹性粘土礦物之屏東新埤試區，後者稻谷增產為3%，及氮肥回收率在8%～41%之間。 施用稻穀亦可提高氮肥回收率，同時增加植體氮鉀含量因而提高稻谷產量，二期作施用之效益，平均增加谷產量8%，大於一期作之增加4%。彰化竹塘一期作加施稻殼者，紋枯病減輕，而谷產量可增加9%以上。 屏東新埤試區無論一、二期水稻施用爐渣後，谷產量有顯著下降之現象，而臺中、彰化兩試區有增產之趨勢。 Increase of N recovery % and grain yield upon USG deep placement, the first rice crop was superior than the second rice crop. For the first rice crop, grain yield increased up to 13%, while N recovery increased up to 77%. However, it was found grain yield of the second rice crop only increased about 3% at Pingtung Experiment Site, while the N recovery rate increased about 41%, lower than that of the first crop by 36%. The effect of USG deep placement on grain yield and N recovery rate may be relatedto existing of expanding clay minerals in soils. As higher amount of expanding clay minerals in Taichung soil, grain yield increased by 18% and N recovery rate increased from 30% to 71%. At Pintung Experiment Site, the soil contains no expanding clay minerals, grain yield only increased by 3% and N recovery rate also increase from 8% to 41%. Increasing the fertilizer efficiency of USG deep placement may be partly attributed to the higher ammonium adaptive nature due to the existence of expanding clay minerals in soils This may explain why higher N recovery rate of USG deep placement at Taichung site and lower at Pingtung site Application of rice husk increased not only withe increasing N recovery rate but also increased with uptake of N and K by rice plant. As respond to the grain yield, it increased about 9% for the second rice crop, and 4% for the first rice crop in general. The use of rice husk also depressed banded sclerotial disease of rice plant which in turn increased grain yield by 9% at Changhua Site. Based on our results, response of grain yield increase by application of rice husk was much significant than the use of slag. In Pingtung, use of slag even caused slightly yield decline. But with use of slag combined with rice husk, it significantly reduced the tendency of grain yield decline

Proteomic analysis of chondrocytes exposed to pressure

Chondrocytes are the only cell type present in mature articular cartilage (2-5% of total tissue). The biological activities of the chondrocyte population are regulated by genetic, biologic and biochemical factors, as well as environmental factors (stress, flow and electric field). Although compressive forces within joint articular cartilage are required for maintenance of the normal composition of articular cartilage, there is a lack of knowledge about the number of pressure-related proteins expressed in articular cartilage. Two-dimensional gel electrophoresis (2-DE) and high-performance liquid chromatography-electrospray/tandem mass spectrometry (HPLC/ESI-MS/MS) were used to identify the levels of pressure-related proteins expressed by chondrocytes grown in the presence or absence of hydrostatic pressure. A total of 266 spots were excised from the gels and analyzed by HPLC/ESI-MS/MS. Functional classification of up-regulated proteins indicated that energy and protein fate were the main biological processes occurring in pressurized chondrocytes. Furthermore, membrane-bound transferrin-like protein p97, a marker of chondrocyte differentiation, was only expressed in chondrocytes under hydrostatic pressure. These data suggest that hydrostatic pressure can induce cell differentiation by increasing the expression level of energy metabolism-and protein fate-related proteins, indicating that hydrostatic pressure may be needed for normal biosynthesis and differentiation of articular chondrocytes. Copyright (C) 2010 John Wiley & Sons, Ltd

Clinical Trials of Antifungal Prophylaxis among Patients Undergoing Surgery

Invasive mycoses have emerged as a major cause of morbidity and mortality. Epidemiological studies have shown that surgery services have the highest rate of Candida infections in the hospital. In addition to classical risk factors, heavy Candida colonization, recurrent gastrointestinal perforations, and acute pancreatitis are frequently associated with invasive candidiasis. Because prompt initiation of antifungal therapy is critical for cure but difficult to accomplish, prevention of fungal infections may play an important role in this clinical setting; however, few prophylactic or preemptive studies have been done to date. The choice, route of administration, and dose of the antifungal and comparator regimens and the use of clinically relevant and robust study end points are critical for the trial design. Various criteria have been used to identify patients at risk of candidiasis: surgical condition, presence of multiple risk factors, colonization indexes, or expected length of stay in the intensive care unit. Some are not selective enough, and others are time consuming and expensive. Rigorous selection of high-risk patients is crucial to optimize the risk-benefit ratio of preventive antifungal strategies. The aim is to maximize chances of reducing morbidity and mortality while minimizing treatment costs, exposure of low-risk patients to adverse events, and emergence of resistant fungal strain

Comparative proteomic profiling of human lung adenocarcinoma cells (CL 1-0) expressing miR-372

Lung cancer is a common malignancy and has a poor overall prognosis. Widespread metastasis is a common phenomenon in non-small cell lung cancer (NSCLC). It has been demonstrated that cancer relapse and survival can be predicted by the presence of a five-microRNA (miRNA) signature independent of stage or histologic type in NSCLC patients. Among the five miRNAs in the signature, miR-372 has been shown to play a significant role in metastasis and in the development of human testicular germ cell tumors. In addition, there is evidence that miR-372 posttranscriptionally downregulates large tumor suppressor, homolog 2 (Lats2), resulting in tumorigenesis and proliferation. To further investigate the cellular mechanisms involved in miR-372-induced silencing, we conducted a comparative proteomic analysis of NSCLC CL 10 cells expressing miRNA-372 and/or vector only by using two-dimensional gel electrophoresis (2DE), two-dimensional difference gel electrophoresis (2D-DIGE), and LC/MS/MS. Proteins identified as being up- or downregulated were further classified according to their biological functions. Many of the proteins identified in our study may be potential diagnostic biomarkers of NSCLC, particularly phosphorylated eIF4A-I

Partial eigenstructure assignment for the quadratic pencil

It is shown in this paper that, by the appropriate choice of gain and input influence matrices, certain eigenpairs of a vibrating system may be assigned while the other eigenpairs remain unchanged. The system under consideration is modelled by a set of second order differential equations and the assignment is carried by multi-input state feedback control. The solution may be of particular interest in the stabilization and control of flexible structures using smart materials, where only a small part of the eigenstructure is to be reassigned and the rest is required to remain unchanged. The method presented is illustrated with a numerical example