317 research outputs found

    Studies toward the total syntheses of waixenicin A and jerantinine E

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    Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

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    This review describes strategies for the chemical synthesis of xenicane diterpenoids and structurally related metabolites. Selected members from the four different subclasses of the Xenia diterpenoid family, the xenicins, xeniolides, xeniaphyllanes and xeniaethers, are presented. The synthetic strategies are discussed with an emphasis on the individual key reactions for the construction of the uncommon nine-membered carbocycle which is the characteristic structural feature of these natural products. Additionally, the putative biosynthetic pathway of xenicanes is illustrated

    Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

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    This review describes strategies for the chemical synthesis of xenicane diterpenoids and structurally related metabolites. Selected members from the four different subclasses of the Xenia diterpenoid family, the xenicins, xeniolides, xeniaphyllanes and xeniaethers, are presented. The synthetic strategies are discussed with an emphasis on the individual key reactions for the construction of the uncommon nine-membered carbocycle which is the characteristic structural feature of these natural products. Additionally, the putative biosynthetic pathway of xenicanes is illustrated

    Studies toward the total syntheses of waixenicin A and jerantinine E

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    Integracija spletnega portala za e-poslovanje s podjetji z ostalimi informacijskimi sistemi v trgovski organizaciji

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    Web portal Merkur Partner enables the insight into specific business information over the Internet to external users. This paper - case study discusses the integration between web portal Merkur Partner and other information systems in the company Merkur,d.d.. Data which is displayed in the web portal, already exist in other company's information systems, therefore it is useful to integrate these system and increase business efficiency. The interchange of data between the systems is performed automatically, without human intervention. The most important data flows between the systems are article data, orders and inquires, sales promotions, partners and their users data, subcatalogues and contact persons in Merkur. In this paper the major problems of integration of web portal Merkur Partner with other information systems in Merkur are presented. The paper introduces the further development of the solution and organizational measures, needed for efficient web portal management. Key words: web portal, information system integration, business information, trade, B2BSpletni portal Merkur Partner omogoča zunanjim uporabnikom vpogled v specifične poslovne informacije preko interneta. Članek – študija primera obravnava integracijo spletnega portala Merkur Partner in ostalih informacijskih sistemov v podjetju Merkur, d.d.. Podatki, ki jih prikazujemo v spletnem portalu, namreč že obstajajo v drugih informacijskih sistemih podjetja, zato je smiselno te sisteme integrirati in s tem povečati učinkovitost poslovanja. Izmenjava podatkov med sistemoma se izvaja avtomatizirano, brez posega človeka. Najbolj pomembni podatkovni tokovi med sistemoma so podatki o artiklih, naročila in povpraševanja, prodajne akcije, podatki o partnerjih in njihovih uporabnikih, podkatalogi ter kontaktne osebe v Merkurju. V članku so obravnavani glavni problemi integracije portala Merkur Partner z ostalimi IS v Merkurju ter predstavljen nadaljnji razvoj rešitve in organizacijski ukrepi, ki so potrebni za učinkovito obvladovanje spletnega portala. Ključne besede: spletni portal, integracija informacijskih sistemov, poslovne informacije, trgovina, B2

    Chromosomal Rearrangements in Post-Chernobyl Papillary Thyroid Carcinomas: Evaluation by Spectral Karyotyping and Automated Interphase FISH

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    Structural genomic rearrangements are frequent findings in human cancers. Therefore, papillary thyroid carcinomas (PTCs) were investigated for chromosomal aberrations and rearrangements of the RET proto-oncogene. For this purpose, primary cultures from 23 PTC have been established and metaphase preparations were analysed by spectral karyotyping (SKY). In addition, interphase cell preparations of the same cases were investigated by fluorescence in situ hybridisation (FISH) for the presence of RET/PTC rearrangements using RET-specific DNA probes. SKY analysis of PTC revealed structural aberrations of chromosome 11 and several numerical aberrations with frequent loss of chromosomes 20, 21, and 22. FISH analysis for RET/PTC rearrangements showed prevalence of this rearrangement in 72% (16 out of 22) of cases. However, only subpopulations of tumour cells exhibited this rearrangement indicating genetic heterogeneity. The comparison of visual and automated scoring of FISH signals revealed concordant results in 19 out of 22 cases (87%) indicating reliable scoring results using the optimised scoring parameter for RET/PTC with the automated Metafer4 system. It can be concluded from this study that genomic rearrangements are frequent in PTC and therefore important events in thyroid carcinogenesis

    To eat or not to eat? Indicators for reduced food intake in 91,245 patients hospitalized on nutritionDays 2006-2014 in 56 countries worldwide: A descriptive analysis

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    Background: Inadequate nutrition during hospitalization is strongly associated with poor patient outcome, but ensuring adequate food intake is not a priority in clinical routine worldwide. This lack of priority results in inadequate and unbalanced food intake in patients and huge amounts of wasted food. Objectives: We evaluate the main factors that are associated with reduced meal intake in hospitalized patients and the differences between geographical regions. Design: We conducted a descriptive analysis of data from 9 consecutive, annual, and cross-sectional nutritionDay samples (2006-2014) in a total of 91,245 adult patients in 6668 wards in 2584 hospitals in 56 countries. A general estimation equation methodology was used to develop a model for meal intake, and P-value thresholding was used for model selection. Results: The proportion of patients who ate a full meal varied widely (24.7-61.5%) across world regions. The factors that were most strongly associated with reduced food intake on nutritionDay were reduced intake during the previous week (OR: 0.20; 95% CI: 0.17, 0.22), confinement to bed (OR: 0.49; 95% CI: 0.44, 0.55), female sex (OR: 0.53; 95% CI: 0.5, 0.56), younger age (OR: 0.74; 95% CI: 0.64, 0.85) and older age (OR: 0.80; 95% CI: 0.74; 0.88), and low body mass index (OR: 0.84; 95% CI: 0.79, 0.90). The pattern of associated factors was homogenous across world regions. Conclusions: A set of factors that are associated with full meal intake was identified and is applicable to patients hospitalized in any region of the world. Thus, the likelihood for reduced food intake is easily estimated through access to patient characteristics, independent of world regions, and enables the easy personalization of food provision

    Kadmij i olovo u uzorcima vučje jetre: optimizacija metode razgradnje uzoraka uz pomoć mikrovalova

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    A microwave-assisted digestion method for the determination of cadmium (Cd) and lead (Pb) by inductively coupled plasma mass spectrometry (ICP-MS) was optimised on certified reference material (CRM) (bovine liver, BCR-185R) and wolf liver samples. Different factors influencing digestion efficiency (temperature, time, composition of the digestion mixture, sample mass) were tested. Validation included linearity (up to 200 μg L-1 for Cd and Pb), detection (0.003 μg L-1 for Cd and 0.035 μg L-1 for Pb), and quantification (0.008 μg L-1 for Cd and 0.081 μg L-1 for Pb) limits. Good agreement between measured and certified values was achieved in all conditions, with recoveries ranging from 94 % to 111 % for Cd and from 95 % to 105 % for Pb. The precision of the method, expressed as relative standard deviation, was up to 3 % for Cd and 8 % for Pb. The best digestion parameters (260 °C, 30 min, 1 mL HNO3+4 mL H2O, 0.1 g of CRM) based on accuracy and precision were applied on two wolf liver samples to evaluate the need for the predigestion step (freeze-drying) and appropriate mass of the sample. Freeze-drying improved precision and minimising the tissue mass to 0.1 g reduced the matrix effect. Using these optimised digestion conditions, we determined Cd and Pb in 40 wolf livers collected in Croatia, and their medians (0.055 μg g-1 and 0.107 μg g-1, respectively) were in the range of previously reported data for the grey wolf.Certifi cirani referenti materijal (CRM) govedskih jetara (BCR-185R) i uzorci vučjih jetara koristili su se za optimizaciju metode razgradnje uzoraka prije mjerenja kadmija (Cd) i olova (Pb) masenom spektrometrijom induktivno spregnute plazme (ICP-MS). Ispitivani su različiti uvjeti koji utječu na učinkovitost razgradnje (temperatura, vrijeme, sastav otopine za razgradnju, masa uzorka). Validacijom je obuhvaćeno ispitivanje linearnosti (do 200 μg L-1 Cd/Pb), granice detekcije (0,003 μg L-1 za Cd, 0.035 μg L-1 za Pb) i kvantifikacije (0,008 μg L-1 za Cd, 0,081 μg L-1 za Pb). Postignuto je dobro slaganje izmjerenih i certificiranih vrijednosti u svim ispitivanim uvjetima uz izračunati raspon iskorištenja 94 % do 111 % za Cd i 95 % do 105 % za Pb. Najveća relativna standardna devijacija, kao mjera preciznosti, iznosila je 3 % za Cd i 8 % za Pb. Najbolji uvjeti za razgradnju (260 °C, 30 min, 1 mL HNO3+4 mL H2O, 0,2 g CRM), izabrani prema točnosti i preciznosti, primijenjeni su na uzorke vučjih jetara pri procjeni odgovarajuće mase uzorka i potrebe za uvođenjem dodatnog koraka prije razgradnje (liofilizacije). Liofilizacija poboljšava preciznost pa je preporučujemo pri pripremi uzoraka tkiva. Također, najmanja masa uzorka izabrana je ne samo zbog bolje preciznosti nego i zbog najmanjeg utjecaja matrice te potrebne količine tkiva. Medijani Cd (0,055 μg g-1) i Pb (0,107 μg g-1 mokre mase) dobiveni analizom 40 uzoraka vučjih jetara skupljenih u Hrvatskoj bili su u rasponu vrijednosti objavljenih u literaturi za sivog vuka

    Subgroup-specific gene expression profiles and mixed epistasis in chronic lymphocytic leukemia

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    Understanding the molecular and phenotypic heterogeneity of cancer is a prerequisite for effective treatment. For chronic lymphocytic leukemia (CLL), recurrent genetic driver events have been extensively cataloged, but this does not suffice to explain the disease's diverse course. Here, we performed RNA sequencing on 184 CLL patient samples. Unsupervised analysis revealed two major, orthogonal axes of gene expression variation: the first one represented the mutational status of the immunoglobulin heavy variable (IGHV) genes, and concomitantly, the three-group stratification of CLL by global DNA methylation. The second axis aligned with trisomy 12 status and affected chemokine, MAPK and mTOR signaling. We discovered non-additive effects (epistasis) of IGHV mutation status and trisomy 12 on multiple phenotypes, including the expression of 893 genes. Multiple types of epistasis were observed, including synergy, buffering, suppression and inversion, suggesting that molecular understanding of disease heterogeneity requires studying such genetic events not only individually but in combination. We detected strong differentially expressed gene signatures associated with major gene mutations and copy number aberrations including SF3B1, BRAF and TP53, as well as del(17)(p13), del(13)(q14) and del(11)(q22.3) beyond dosage effect. Our study reveals previously underappreciated gene expression signatures for the major molecular subtypes in CLL and the presence of epistasis between them

    Over-Detection of Melanoma-Suspect Lesions by a CE-Certified Smartphone App: Performance in Comparison to Dermatologists, 2D and 3D Convolutional Neural Networks in a Prospective Data Set of 1204 Pigmented Skin Lesions Involving Patients’ Perception

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    The exponential increase in algorithm-based mobile health (mHealth) applications (apps) for melanoma screening is a reaction to a growing market. However, the performance of available apps remains to be investigated. In this prospective study, we investigated the diagnostic accuracy of a class 1 CE-certified smartphone app in melanoma risk stratification and its patient and dermatologist satisfaction. Pigmented skin lesions ≥ 3 mm and any suspicious smaller lesions were assessed by the smartphone app SkinVision® (SkinVision® B.V., Amsterdam, the Netherlands, App-Version 6.8.1), 2D FotoFinder ATBM® master (FotoFinder ATBM® Systems GmbH, Bad Birnbach, Germany, Version 3.3.1.0), 3D Vectra® WB360 (Canfield Scientific, Parsippany, NJ, USA, Version 4.7.1) total body photography (TBP) devices, and dermatologists. The high-risk score of the smartphone app was compared with the two gold standards: histological diagnosis, or if not available, the combination of dermatologists’, 2D and 3D risk assessments. A total of 1204 lesions among 114 patients (mean age 59 years; 51% females (55 patients at high-risk for developing a melanoma, 59 melanoma patients)) were included. The smartphone app’s sensitivity, specificity, and area under the receiver operating characteristics (AUROC) varied between 41.3–83.3%, 60.0–82.9%, and 0.62–0.72% according to two study-defined reference standards. Additionally, all patients and dermatologists completed a newly created questionnaire for preference and trust of screening type. The smartphone app was rated as trustworthy by 36% (20/55) of patients at high-risk for melanoma, 49% (29/59) of melanoma patients, and 8.8% (10/114) of dermatologists. Most of the patients rated the 2D TBP imaging (93% (51/55) resp. 88% (52/59)) and the 3D TBP imaging (91% (50/55) resp. 90% (53/59)) as trustworthy. A skin cancer screening by combination of dermatologist and smartphone app was favored by only 1.8% (1/55) resp. 3.4% (2/59) of the patients; no patient preferred an assessment by a smartphone app alone. The diagnostic accuracy in clinical practice was not as reliable as previously advertised and the satisfaction with smartphone apps for melanoma risk stratification was scarce. MHealth apps might be a potential medium to increase awareness for melanoma screening in the lay population, but healthcare professionals and users should be alerted to the potential harm of over-detection and poor performance. In conclusion, we suggest further robust evidence-based evaluation before including market-approved apps in self-examination for public health benefits
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