42 research outputs found
Supplemental Material - “Switching Hats”: Insights From Experienced Clinical Interviewers Turned Novice Research Interviewers
No full textSupplemental Material for “Switching Hats”: Insights From Experienced Clinical Interviewers Turned Novice Research Interviewers by Brightlin N. Dhas, Jackie Fox, Benshamir Bright, Dina B. El Haj, Abraham P. James, Hussain A. H. J. Bu Hazaa, and Sultan S. H. Al Abdulla in Qualitative Health Research</p
Adrenal function in Subgroups of the PCO Syndrome assessed by a long ACTH test
No full textFifteen patients with the polycystic ovarian (PCO) syndrome were classified into Group A (n= 6) and Group B (n= 9) based on their LH responses to LHRH before and at 44 and 92h after administration of oestradiol benzoate. Adrenal function in both groups was assessed by comparing the hormone responses to ACTH (0.5mg twice daily for 4 days) with those obtained in nine normally ovulating women during the early follicular phase of their cycles. In Group A patients there was no significant difference from normals in the serum concentration of dehydroepiandrosterone sulphate (DHAS), 17α‐hydroxy‐progesterone (17‐OHP) or androgens (testosterone and dihydrotestosterone). In contrast, the serum concentrations in Group B were significantly higher (P<0.01) for each of these steroids before ACTH, and remained higher at 2 and 4 days for DHAS, but not for the other two steroids. The concentration of oestrone was significantly higher (P<0.05) in Group B patients before, and 2 days after, ACTH, while in Group A patients higher concentrations (P<0.02) were found only after 2 days. The concentrations of oestradiol, on the other hand, were not different from normal in either group before ACTH and became lower than normal in both groups at 2 days and remained lower at 4 days in Group B. The concentration of cortisol was within the normal range throughout in Group A, but was lower than normal after 4 days in Group B patients (P<0.05). The ratios between the sums of concentrations of DHAS to cortisol on days 2 and 4 (P<0.001) or 17‐OHP to cortisol (P<0.05) were elevated in Group B compared with normal subjects. LH, FSH and prolactin values were normal throughout in Group A, but in Group B patients the mean value for LH was significantly elevated before ACTH and at 4 days after ACTH (P<0.02).</p
Leveraging the Photochemistry of N-Nitrosamines for Their Aqueous Detection, and Development of a Novel Hemi-Iptycene for Porous Polymers
No full textN-Nitrosamines are a class of compounds known for both the potent carcinogenicity of many of its members, and for their widespread occurrence in the human environment. Consequently, the development of methods for their detection is an active area of research. Chapter 1 provides an introduction to the structure, reactivity, and synthetic applications of N-nitrosamines with an emphasis on alkyl N-nitrosamines. The role of N-nitrosamines as water contaminants and the methods for their detection are also discussed.
In Chapter 2, two synthetic routes are used to synthesize several 9,9-disubstituted-9,10-dihydroacridines (DHAs). In one route, the final synthetic step consists of acid-promoted cyclization of a benzyl tertiary alcohol intermediate; for some substrates, elimination competes with the desired cyclization and leads to reduced yields. For N-substituted DHAs, however, they can instead be synthesized by Grignard addition to the parent acridinium, and portions of this route were adapted for rapid microwave conditions. The synthesized DHAs were evaluated as potential nitrosamine indicators and were found unsuitable for this application.
In Chapter 3, the detection of aqueous nitrosamines via photonitrosation of a naphtholsulfonate indicator is described. The initial photoreaction yields an ortho-naphthoquinone-oxime, and the colorimetric response is enhanced by the formation of an intensely green iron(II) complex. The sensitivity and selectivity of the resulting solution-phase assay are evaluated, and efforts towards a solid-supported assay are described. Additionally, the iron complex formed in the assay and the analogous commercial dye Naphthol Green B are characterized by Mössbauer and EPR spectroscopy, and the resulting characterization indicates that both compounds are low-spin iron(II) complexes.
In Chapter 4, the synthesis of a novel hemi-iptycene diacetylene monomer, whose core structure is derived from triptycene and diphenylfulvene, is described. The hemi-iptycene quinone precursor to the diacetylene monomer is constructed by the one-pot Diels–Alder cycloaddition–dehydrochlorination of 2-chlorotriptycene quinone with diphenylfulvene, which is performed as a neat melt. Other attempted synthetic routes to the quinone are described as well. Lastly, preliminary results from the Sonogashira polymerization of the hemi-iptycene monomer with two dihalide fluorene monomers are described.Ph.D
Fuzzy logic based dynamic sliding mode control of boost inverter in photovoltaic application
No full text
INHIBITION OF STEROID SULFATASE ACTIVITY BY STEROIDAL METHYLTHIOPHOSPHONATES - POTENTIAL THERAPEUTIC AGENTS IN BREAST-CANCER
No full textThe hydrolysis of steroid sulphates, by steroid sulphatase, is an important source of oestrogenic steroids (oestrone, oestradiol and 5-androstene-3 beta,17 beta-diol) which are found in tumours. In the present study, we have examined the effect of dehydroepiandrosterone-3-O-methylthiophosphonate (DHA-3-MTP), pregnenolone-3-O-methylthiophosphonate (pregnenolone-3-MTP) and cholesterol-3-O-methylthiophosphonate (cholesterol-3-MTP) on the inhibition of oestrone sulphatase as well as DHA sulphatase activities in intact MCF-7 breast cancer cells and in placental microsomes. All three methylthiophosphonates significantly (P < 0.01) inhibited the hydrolysis of oestrone sulphate (E(1)S) in intact MCF-7 cells (31-85% inhibition at 1 mu M and 53-97% inhibition at 10 mu M). Significant inhibition of DHA sulphatase was also achieved. At a concentration of 50 mu M, all three compounds inhibited the hydrolysis of dehydroepiandrosterone sulphate (DHAS) by > 95%. Using human placental microsomes, the K-m and V-max of E(1)S were determined to be 8.1 mu M and 43 nmol/h/mg protein. The corresponding K-i values for DHA-3-MTP, pregnenolone-3-MTP and cholesterol-3-MTP were found to be 4.5, 1.4 and 6.2 mu M, respectively. Such inhibitors which are resistant to metabolism may have considerable potential as therapeutic agents and may have additional advantage over aromatase inhibitors in also reducing tumour concentrations of the oestrogenic steroid, 5-androstene-3 beta,17 beta-diol, by inhibiting the hydrolysis of DHAS.</p
Comparative proteomic analysis of four Bacillus clausii strains: Proteomic expression signature distinguishes protein profile of the strains
No full textA comparative proteomic approach, using two dimensional gel electrophoresis and mass spectrometry, has been developed to compare and elucidate the differences among the cellular proteomes of four closely related isogenic O/C, SIN, N/R and T, B. clausii strains during both exponential and stationary phases of growth. Image analysis of the electropherograms reveals a high degree of concordance among the four proteomes, some proteins result, however, differently expressed. The proteins spots exhibiting high different expression level were identified, by mass-spectrometry analysis, as alcohol dehydrogenase (ADHA, EC1.2.1.3; ABC0046 isoform) aldehyde dehydrogenase (DHAS, EC 1.2.1.3; ABC0047 isoform) and flagellin-protein of B. clausii KSM-k16. The different expression levels of the two dehydrogenases were confirmed by quantitative RT-PCR and dehydrogenases enzymatic activity. The different patterns of protein expression can be considered as cell proteome signatures of the different strains. (C) 2011 Elsevier B.V. All rights reserved
Management for Clinicians - A Handbook
Full text linkThis Handbook has been compiled with the object of assembling together many of the more important recent official documents and informed statements about the organisation, planning and management of the National Health Service. The contents of the Handbook are
therefore concerned essentially with supplying information, not with criticism or evaluation. The sections in Part 1 of the Handbook cover the major areas to be discussed at the Seminar. The first section discusses the involvement of clinicians in management, and the next section examines the demands and constraints facing providers of health care. This is followed by a section setting out the revised structure of the NHS. The final four sections are
concerned with planning, the medical advisory machinery, industrial relations, and allocating money in the NHS. Part 2 of the Handbook presents some facts about the Region and Part 3 reproduces, FOR REFERENCE ONLY, some of the key circulars about the structure and management of the NHS
Enzymatic Synthesis Process of EPA- and DHA-Enriched Structured Acylglycerols at the sn-2 Position Starting from Commercial Salmon Oil and Concentrated by Response Surface Methodology under Supercritical Conditions
No full textThe bioavailability of n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs) has shown to be greatly influenced by their location in the triacylglycerol backbone. Therefore, the synthesis of structured acylglycerols (SAcyl), which include eicosapentaenoic acids (EPAs) or docosahexaenoic acids (DHAs) at the sn-2 position, has attracted a great interest. The objective of this study was to optimize the synthesis process of a SAcyl from commercial refined salmon oil and an EPA/DHA concentrate in order to enhance the positioning of EPA and DHA in the sn-2 location of the glycerol moiety. For this purpose, immobilized lipase B from Candida antarctica (nonspecific) was used for the acidolysis process under the CO2 supercritical condition. As a result of carrying out a Draper-Lin composite design through the response surface methodology of 18 experiments, an optimized extraction including SAcyl compounds was obtained. Mass spectrometry (MALDI-TOF) analysis was employed to identify the EPA/DHA location at the sn-2 position in the resulting glycerol moiety. In the fraction obtained, an increase in the EPA and DHA content at the sn-2 position was detected. Remarkably, the optimized SAcyl obtained after 6 h, 82 bar, and 60 °C led to the highest EPA/DHA yield at the sn-2 position in the resulting molecule
Copper Nanoparticles Prepared fromOxalic Precursors
Full text linkThe synthesis of nanoparticles of copper metal via a soft chemistry route is presented in this paper. The method is based on the thermal decomposition under nitrogen or hydrogen of oxalic precursors with a well-controlled morphology and particle size. The precipitation of the copper oxalates in a water-alcohol medium allows the submicron size of the precursor grains to be controlled and, consequently, the nanometric size of the metallic copper particles to be determined, as required, between 3.5 and 40 nm. The majority of the final particles are made of pure copper metal although some present a superficial layer of cuprous oxide (Cu2O)
