Biosynthetic pathway of prescription cucurbitacin IIa and high-level production of key triterpenoid intermediates in engineered yeast and tobacco

Cucurbitacin IIa is a triterpenoid isolated exclusively from Hemsleya plants and a non-steroidal anti-inflammatory drug that functions as the main ingredient of prescription Hemslecin capsules and tablets in China. Synthetic biology provides new strategies for production of such valuable cucurbitacins at a large scale; however, the biosynthetic pathway of cucurbitacin IIa has been unknown, and the heterologous production of cucurbitacins in galactose medium has been expensive and low yielding. In this study, we characterized the functions of genes encoding two squalene epoxidases (HcSE1-2), six oxidosqualene cyclases (HcOSC1-6), two CYP450s (HcCYP87D20 and HcCYP81Q59), and an acyltransferase (HcAT1) in cucurbitacin IIa biosynthesis by heterologous expression in Saccharomyces cerevisiae and Nicotiana benthamiana. We achieved high-level production of the key cucurbitacin precursor 11-carbonyl-20β-hydroxy-Cuol from glucose in yeast via modular engineering of the mevalonate pathway and optimization of P450 expression levels. The resulting yields of 46.41 mg/l 11-carbonyl-20β-hydroxy-Cuol and 126.47 mg/l total cucurbitacin triterpenoids in shake flasks are the highest yields yet reported from engineered microbes. Subsequently, production of 11-carbonyl-20β-hydroxy-Cuol by transient gene expression in tobacco resulted in yields of 1.28 mg/g dry weight in leaves. This work reveals the key genes involved in biosynthesis of prescription cucurbitacin IIa and demonstrates that engineered yeast cultivated with glucose can produce high yields of key triterpenoid intermediates. We describe a low-cost and highly efficient platform for rapid screening of candidate genes and high-yield production of pharmacological triterpenoids.

A Theoretical Study on the Underlying Factors of the Difference in Performance of Organic Solar Cells Based on ITIC and Its Isomers

Recently, non-fullerene-based organic solar cells (OSCs) have made great breakthroughs, and small structural differences can have dramatic impacts on the power conversion efficiency (PCE). We take ITIC and its isomers as examples to study their effects on the performance of OSCs. ITIC and NFBDT only differed in the side chain position, and they were used as models with the same donor molecule, PBDB-T, to investigate the main reasons for the difference in their performance in terms of theoretical methods. In this work, a detailed comparative analysis of the electronic structure, absorption spectra, open circuit voltage and interfacial parameters of the ITIC and NFBDT systems was performed mainly by combining the density functional theory/time-dependent density functional theory and molecular dynamics simulations. The results showed that the lowest excited state of the ITIC molecule possessed a larger ∆q and more hybrid FE/CT states, and PBDB-T/ITIC had more charge separation paths as well as a larger kCS and smaller kCR. The reason for the performance difference between PBDB-T/ITIC and PBDB-T/NFBDT was elucidated, suggesting that ITIC is a superior acceptor based on a slight modulation of the side chain and providing a guiding direction for the design of superior-performing small molecule acceptor materials.

Ultra-High Capacity Optical Satellite Communication System Using PDM-256-QAM and Optical Angular Momentum Beams

Twisted light beams such as optical angular momentum (OAM) with numerous possible orthogonal states have drawn the prodigious contemplation of researchers. OAM multiplexing is a futuristic multi-access technique that has not been scrutinized for optical satellite communication (OSC) systems thus far, and it opens up a new window for ultra-high-capacity systems. This paper presents the 4.8 Tbps (5 wavelengths × 3 OAM beams × 320 Gbps) ultra-high capacity OSC system by incorporating polarization division multiplexed (PDM) 256-Quadrature amplitude modulation (256-QAM) and OAM beams. To realize OAM multiplexing, Laguerre Gaussian (LG) transverse mode profiles such as LG00, LG140, and LG400 were used in the proposed study. The effects of the receiver's digital signal processing (DSP) module were also investigated, and performance improvement was observed using DSP for its potential to compensate for the effects of dispersion, phase errors, and nonlinear effects using the blind phase search (BPS), Viterbi phase estimation (VPE), and the constant modulus algorithm (CMA). The results revealed that the proposed OAM-OSC system successfully covered the 22,000 km OSC link distance and, out of three OAM beams, fundamental mode LG00 offered excellent performance. Further, a detailed comparison of the proposed system and reported state-of-the-art schemes was performed.

Prediction at the intersection of sentence context and word form: Evidence from eye-movements and self-paced reading

A key issue in language processing is how we recognize and understand words in sentences. Research on sentence reading indicates that the time we need to read a word depends on how (un)expected it is. Research on single word recognition shows that each word also has its own recognition dynamics based on the relation between its orthographic form and its meaning. It is not clear, however, how these sentence-level and word-level dynamics interact. In the present study, we examine the joint impact of these sources of information during sentence reading. We analyze existing eye-tracking and self-paced reading data (Frank et al., 2013, Behavior Research Methods, 45[4], 1182-1190) to investigate the interplay of sentence-level prediction (operationalized as Surprisal) and word Orthography-Semantics Consistency in activating word meaning in sentence processing. Results indicate that both Surprisal and Orthography-Semantics Consistency exert an influence on several reading measures. The shape of the observed interaction differs, but the results give compelling indication for a general trade-off between expectations based on sentence context and cues to meaning from word orthography.

Genome-Wide Identification of OSC Gene Family and Potential Function in the Synthesis of Ursane- and Oleanane-Type Triterpene in Momordica charantia

The triterpenes in bitter gourd (Momordica charantia) show a variety of medicinal activities. Oxidosqualene cyclase (OSC) plays an indispensable role in the formation of triterpene skeletons during triterpene biosynthesis. In this study, we identified nine genes encoding OSCs from bitter gourd (McOSC1-9). Analyses of their expression patterns in different tissues suggested that characteristic triterpenoids may be biosynthesized in different tissues and then transported. We constructed a hairy root system in which McOSC7 overexpression led to an increased accumulation of camaldulenic acid, enoxolone, and quinovic acid. Thus, the overexpression of McOSC7 increased the active components content in bitter gourd. Our data provide an important foundation for understanding the roles of McOSCs in triterpenoid synthesis.

Comparative Study of the Efficiency of Different Noble Metals Supported on Hydroxyapatite in the Catalytic Lean Methane Oxidation under Realistic Conditions

The combustion of lean methane was studied over palladium, rhodium, platinum, and ruthenium catalysts supported on hydroxyapatite (HAP). The samples were prepared by wetness impregnation and thoroughly characterized by BET, XRD, UV-Vis-NIR spectroscopy, H₂-TPR, OSC, CO chemisorption, and TEM techniques. It was found that the Pd/HAP and Rh/HAP catalysts exhibited a higher activity compared with Pt/HAP and Ru/HAP samples. Thus, the degree of oxidation of the supported metal under the reaction mixture notably influenced its catalytic performance. Although Pd and Rh catalysts could be easily re-oxidized, the re-oxidation of Pt and Ru samples appeared to be a slow process, resulting in small amounts of metal oxide active sites. Feeding water and CO₂ was found to have a negative effect, which was more pronounced in the presence of water, on the activity of Pd and Rh catalysts. However, the inhibiting effect of CO₂ and H₂O decreased by increasing the reaction temperature.

Stickler Syndrome (SS): Laser Prophylaxis for Retinal Detachment (Modified Ora Secunda Cerclage, OSC/SS)

Purpose

To introduce a novel technique of encircling laser prophylaxis (ora secunda cerclage Stickler syndrome, OSC/SS) to prevent rhegmatogenous retinal detachment (RRD) in Stickler syndrome eyes.

Patients and Methods

After first eye RRD at age 50 and at age 18, respectively, a 53-year-old father and his 22-year-old son with type 2 SS (STL2) gave informed consent and underwent OSC/SS prophylaxis, performed in each fellow eye. A 26-year-old STL2 daughter then suffered first eye retinal detachment and similarly chose fellow eye OSC/SS prophylaxis. A second son, 28 years of age with STL2, chose OSC/SS prophylaxis in both eyes.

Results

The three OSC/SS treated fellow eyes have gone 12 years, 11 years, and 8 years without RRD. STL1 and less common STL2 eyes are known to have a similar rate of RRD, and 80% of STL1 fellow eyes develop RRD at a median of 4 years in the absence of prophylaxis. Moreover, five of six (83%) known STL2 family members suffered RRD, only the STL2 son with bilateral OSC/SS remaining bilaterally attached. All five OSC/SS treated eyes (average 8.7 years post-prophylaxis) retained preoperative visual acuity of 20/20 to 20/30, with an average, asymptomatic reduction of meridional field in each eye to 50 degrees. In contrast, in the three eyes having suffered RRD prior to presentation, visual acuity ranged from 20/125 to 8/200 and average meridional field was 29 degrees.

Conclusion

Encircling grid laser (OSC) modified in Stickler eyes to encompass the ora serrata and extend posteriorly to and between the vortex vein ampullae (OSC/SS) is a reasonable RRD prophylaxis option to offer STL1 and STL2 patients as an alternative to no treatment or less effective prophylaxis. Because of rarity and severity, the ultimate proof of safety and efficacy will likely come not from randomized trials, but from a non-randomized, prospective, cohort comparison study of such individual efforts.

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Consistency measures individuate dissociating semantic modulations in priming paradigms: A new look on semantics in the processing of (complex) words

In human language the mapping between form and meaning is arbitrary, as there is no direct connection between words and the objects that they represent. However, within a given language, it is possible to recognise systematic associations that support productivity and comprehension. In this work, we focus on the consistency between orthographic forms and meaning, and we investigate how the cognitive system may exploit it to process words. We take morphology as our case study, since it arguably represents one of the most notable examples of systematicity in form-meaning mapping. In a series of three experiments, we investigate the impact of form-meaning mapping in word processing by testing new consistency metrics as predictors of priming magnitude in primed lexical decision. In Experiment 1, we re-analyse data from five masked morphological priming studies and show that orthography-semantics-consistency explains independent variance in priming magnitude, suggesting that word semantics is accessed already at early stages of word processing and that crucially semantic access is constrained by word orthography. In Experiments 2 and 3, we investigate whether this pattern is replicated when looking at semantic priming. In Experiment 2, we show that orthography-semantics-consistency is not a viable predictor of priming magnitude with longer stimulus onset asynchrony (SOA). However, in Experiment 3, we develop a new semantic consistency measure based on the semantic density of target neighbourhoods. This measure is shown to significantly predict independent variance in semantic priming effect. Overall, our results indicate that consistency measures provide crucial information for the understanding of word processing. Specifically, the dissociation between measures and priming paradigms shows that different priming conditions are associated with the activation of different semantic cohorts.

Expression characteristics and function of CAS and a new beta-amyrin synthase in triterpenoid synthesis in birch (Betula platyphylla Suk.)

Triterpenoids produced by the secondary metabolism of Betula platyphylla Suk. exhibit important pharmacological activities, such as tumor inhibition, anti-HIV, and defense against pathogens, but the yield of natural synthesis is low, which is insufficient to meet people's needs. In this study, we identified two OSC genes of birch, named as BpCAS and Bpβ-AS, respectively. The expression of BpCAS and Bpβ-AS were higher levels in roots and in stems, respectively, and they induced expression in response to methyl jasmonate (MeJA), gibberellin (GA3), abscisic acid (ABA), ethylene and mechanical damage. The function of the two genes in the triterpene synthesis of birch was identified by reverse genetics. The inhibition of Bpβ-AS gene positively regulates synthesis of betulinic acid. BpCAS interference can significantly promote the upregulation of lupeol synthase gene (BPW) and β-amyrin synthase gene(BPY), and conversion of 2,3-oxidosqualene to the downstream products betulinic acid and oleanolic acid. This study provided a basis for the genetic improvement of triterpenoid synthesis in birch through genetic engineering. The obtained transgenic birch and suspension cells served as material resources for birch triterpenoid applications in further.

Biosynthesis of cycloartenol by expression of plant and bacterial oxidosqualene cyclases in engineered Rhodobacter capsulatus

Cyclic triterpenes are a large group of secondary metabolites produced by plants, fungi and bacteria. They have diverse biological functions, and offer potential health benefits for humans. Although various terpenes from the mono-, sesqui- and diterpene classes are easy to produce in engineered bacteria, heterologous synthesis of cyclic triterpenes is more challenging. We have recently shown that the triterpene cycloartenol can be produced in Rhodobacter capsulatus SB1003 but initial titers were low with 0.34mgL^-1. To assess, if this phototrophic α-proteobacterium can be engineered for enhanced triterpene production, we followed two alternative strategies by comparing the performance of the R. capsulatus SB1003 wildtype strain with two recombinant strains carrying either a mevalonate pathway implemented from Paracoccus zeaxanthinifaciens or a deletion in the intrinsic carotenoid biosynthesis gene crtE. These strains are thus engineered for an enhanced isoprenoid biosynthesis or a suppressed precursor conversion by the competing carotenoid pathway. Moreover, three different cycloartenol synthase (CAS) genes from Arabidopsis thaliana or the myxobacterial strains Stigmatella aurantiaca Sga15 and DW4/3-1 were tested for heterologous cycloartenol synthesis. We found that the heterologous expression of mevalonate pathway enzymes had little impact on cycloartenol levels irrespective of the chosen CAS. In contrast, the use of the newly constructed carotenoid-deficient crtE deletion strain showed threefold increased cycloartenol product titers. We conclude that R. capsulatus is a promising alternative host for the functional expression of triterpene biosynthetic enzymes from plants and microbes. Apparently, product titers can also be improved by suppression of competing precursor consumption.

A five-DNA methylation signature act as a novel prognostic biomarker in patients with ovarian serous cystadenocarcinoma

Background

Ovarian cancer is the most fatal tumor of the female reproductive system and the fifth leading cause of cancer death among women in the USA. The prognosis is poor due to the lack of biomarkers for treatment options.

Results

The methylation array data of 551 patients with ovarian serous cystadenocarcinoma (OSC) in The Cancer Genome Atlas (TCGA) database were assessed in this study to explore the methylation biomarkers associated with prognosis and improve the prognosis of patients. These patients were divided into training (first two thirds) and validation datasets (remaining one third). A five-DNA methylation signature was found to be significantly associated with the overall survival of patients with OSC using the Cox regression analysis in the training dataset. The Kaplan–Meier analysis showed that the five-DNA methylation signature could significantly distinguish the high- and low-risk patients in both training and validation sets. The receiver operating characteristic (ROC) analysis further confirmed that the five-DNA methylation signature exhibited high sensitivity and specificity to predict the prognostic survival of patients. Also, the five-DNA methylation signature was not only applicable in patients of different ages, stages, histologic grade, and size of residual tumor after surgery but also more accurate in predicting OSC prognosis compared with known biomarkers.

Conclusions

This five-DNA methylation signature demonstrated the potential of being a novel independent prognostic indicator and served as an important tool for guiding the clinical treatment of OSC to improve outcome prediction and management for patients. Hence, the findings of this study might have potential clinical significance.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0574-0) contains supplementary material, which is available to authorized users.

Skin cancer risk perception and sun protection behavior at work, at leisure, and on sun holidays: a survey for Danish outdoor and indoor workers

BACKGROUND

To prevent occupational skin cancer, it is essential that the sun-protective behavior of outdoor workers is adequate. The aim is to study the sun-protective behavior of Danish outdoor workers at work, at leisure, and on sun holiday and compare it to that of indoor workers.

METHODS

This is a cross-sectional study, based on a 53-item survey completed by Danish outdoor (n = 380) and indoor workers (n = 119) in 2016-2017. Status as outdoor or indoor worker was decided based on self-report and behavioral differences were tested using (paired) t tests and multiple regression adjusted for age, sex, educational level, history of smoking, and skin type.

RESULTS

Danish outdoor workers at work use sun protection less than they do at leisure and on sun holiday (α < .05) where their sun protection behavior is similar to that of indoor workers. The proportion of Danish outdoor workers that always/often use sun protection at work is for shade seeking around noon 4.2%, sunscreen 34.5%, wide-brimmed hat 25.3%, and long trousers and shirt with sleeves 42.4%. Of Danish outdoor workers, 49.5% do not think about the risk of occupational skin cancer and 11.8% think the risk is insignificant, 32.4% think that the use of sun protection is of low or no importance, 84.2% consider sunburn important as skin cancer risk factor still 88.9% have a history of sunburn at work, > 80.0% agree that risk of skin cancer is reduced by the use of sun protection, and only 4.0% dismiss the possibility of sun protection use at work.

CONCLUSIONS

Skin cancer risk and use of sun protection at work are largely neglected in Danish outdoor workers, more so than at leisure and on sun holiday where their risk behavior resembles that of indoor workers. This indicates an untapped workplace preventive potential.

Profiling Open Chromatin Structure in the Ovarian Somatic Cells Using ATAC-seq

The assay for transposase-accessible chromatin using sequencing (ATAC-seq) was recently established as a method to profile open chromatin, which overcomes the sample size limitations of the alternative methods DNase/MNase-seq. To investigate the role of Piwi in heterochromatin formation around transposable element loci, we have used ATAC-seq to examine chromatin accessibility at target transposable elements in a Drosophila cultured cell line, ovarian somatic cells (OSCs). In this chapter, we describe our method to profile open chromatin structure in OSCs using ATAC-seq.

Dynamics of Additive Migration to Form Cathodic Interlayers in Organic Solar Cells

Migration of additives to organic/metal interfaces can be used to self-generate interlayers in organic electronic devices. To generalize this approach for various additives, metals, and organic electronic devices it is first necessary to study the dynamics of additive migration from the bulk to the top organic/metal interface. In this study, we focus on a known cathode interlayer material, polyethylene glycol (PEG), as additive in P3HT:PC₇₁BM blends and study its migration to the blend/Al interface during metal deposition and its effect on organic solar cell (OSC) performance. Using dynamic secondary ion mass spectroscopy (DSIMS) depth profiles and X-ray photoelectron spectroscopy surface analysis (XPS), we quantitatively correlate the initial concentration of PEG in the blend and sequence of thermal annealing/metal deposition processes with the organic/Al interfacial composition. We find that PEG is initially distributed within the film according to the kinetics of the spin coating process, i.e., the majority of PEG accumulates at the bottom substrate, while the minority resides in the film. During electrode evaporation, PEG molecules kinetically "trapped" near the film surface migrate to the organic/Al interface to reduce the interfacial energy. This diffusion-limited process is enhanced with the initial concentration of PEG in the solution and with thermal annealing after metal deposition. In contrast, annealing the film before metal deposition stalls PEG migration. This mechanism is supported by corresponding OSC devices showing that V_oc increases with PEG content at the interface, up to a saturation value associated with the formation of a continuous PEG interlayer. Presence of a continuous interlayer excludes the driving force for further migration of PEG to the interface. Revealing this mechanism provides practical insight for judicious selection of additives and processing conditions for interfacial engineering of spontaneously generated interlayers.

Ovarian regeneration: The potential for stem cell contribution in the postnatal ovary to sustained endocrine function

The endocrine function of the ovary is dependent upon the ovarian follicle, which on a cellular basis consists of an oocyte surrounded by adjacent somatic cells responsible for generating sex steroid hormones and maintenance of hormonal stasis with the hypothalamic-pituitary axis. As females age, both fertility and the endocrine function of the ovary decline due to waning follicle numbers as well as aging-related cellular dysfunction. Although there is currently no cure for ovarian failure and endocrine disruption, recent advances in ovarian biology centered on ovarian stem cell and progenitor cell populations have brought the prospects of cell- or tissue-based therapeutic strategies closer to fruition. Herein, we review the relative contributions of ovarian stem cells to ovarian function during the reproductive lifespan, and postulate steps toward the development of ovarian stem cell-based approaches to advance fertility treatments, and also importantly to provide a physiological long-term means of endocrine support.

High-Efficiency Polymer Solar Cells with Sm/Ca Bilayer Cathode Buffer

The Sm/Ca bilayer buffers together with Al as the cathode, instead of Al or Ca/Al cathodes are applied into bulk heterojunction polymer solar cells. Accompanied with the optimization of Sm/Ca buffer thicknesses, a high power conversion efficiency of 3.98%, an enhanced short-circuit current density (J(SC)) of 10.87 mA/cm², and a fill factor (FF) of 0.61 are achieved in the poly(3-hexylthiophene): [6,6]-phenyl-C₆₁-butyric acid methyl ester (P3HT:PCBM)-based cell. Analysis on the film’s scanning electron microscopy images, light absorption characteristics, the electromagnetic fields distribution, and scattering illustrates that absorption enhancement induced by Sm clusters via the localized surface plasmon resonance and scattering plays a major role in the enhancement of J SC, while a highly efficient electron extraction and a further resulting large FF is dominated by the Cabuffer.

Assessing and changing organizational social contexts for effective mental health services

Culture and climate are critical dimensions of a mental health service organization's social context that affect the quality and outcomes of the services it provides and the implementation of innovations such as evidence-based treatments (EBTs). We describe a measure of culture and climate labeled Organizational Social Context (OSC), which has been associated with innovation, service quality, and outcomes in national samples and randomized controlled trials (RCTs) of mental health and social service organizations. The article also describes an empirically supported organizational intervention model labeled Availability, Responsiveness, and Continuity (ARC), which has improved organizational social context, innovation, and effectiveness in five RCTs. Finally, the article outlines a research agenda for developing more efficient and scalable organizational strategies to improve mental health services by identifying the mechanisms that link organizational interventions and social context to individual-level service provider intentions and behaviors associated with innovation and effectiveness.

Increasing clinicians' EBT exploration and preparation behavior in youth mental health services by changing organizational culture with ARC

OBJECTIVE

Clinician EBT exploration and preparation behavior is essential to the ongoing implementation of new EBTs. This study examined the effect of the ARC organizational intervention on clinician EBT exploration and preparation behavior and assessed the mediating role of organizational culture as a linking mechanism.

METHOD

Fourteen community mental health agencies that serve youth in a major Midwestern metropolis along with 475 clinicians who worked in those agencies, were randomly assigned to either the three-year ARC intervention or control condition. Organizational culture was assessed with the Organizational Social Context (OSC) measure at baseline and follow-up. EBT exploration and preparation behavior was measured as clinician participation in nine separate community EBT workshops held over a three-year period.

RESULTS

There was 69 percent greater odds (OR = 1.69, p < .003) of clinicians in the ARC condition (versus control) attending each subsequent workshop. Workshop attendance in the control group remained under two percent and declined over three years while attendance in the ARC condition grew from 3.6 percent in the first workshop to 12 percent in the ninth and final workshop. Improvement in proficient organizational culture mediated the positive effect of the ARC intervention on clinicians' workshop attendance (a × b = .21; 95% CI:LL = .05, UL = .40).

CONCLUSIONS

Organizational interventions that create proficient mental health agency cultures can increase clinician EBT exploration and preparation behavior that is essential to the ongoing implementation of new EBTs in community youth mental health settings.

Reduction of NO by CO using Pd-CeTb and Pd-CeZr catalysts supported on SiO2 and La2O3-Al2O3

The catalytic activity of Pd catalysts supported on Ce0.73Tb0.27Ox/SiO2, Ce0.6Zr0.4Ox/SiO2, Ce0.73Tb0.27Ox/La2O3-Al2O3 and Ce0.6Zr0.4Ox/La2O3-Al2O3 was studied using the reduction of NO by CO. The catalysts were characterized by X-ray fluorescence, surface area, X-ray diffraction, temperature-programmed reduction, CO chemisorption and oxygen storage capacity. Temperature-programmed reduction results indicated that Tb or Zr incorporation improves the reducibility and oxygen storage capacity. CO chemisorption data suggested the presence of large PdO particles due to the low CO/Pd ratio. No significant differences were obtained in light off temperatures (TLight off) for all Pd catalysts and the most active was 1.5%Pd/Ce0.6Zr0.4Ox/SiO2.

Merits of random forests emerge in evaluation of chemometric classifiers by external validation

Real-world applications will inevitably entail divergence between samples on which chemometric classifiers are trained and the unknowns requiring classification. This has long been recognized, but there is a shortage of empirical studies on which classifiers perform best in 'external validation' (EV), where the unknown samples are subject to sources of variation relative to the population used to train the classifier. Survey of 286 classification studies in analytical chemistry found only 6.6% that stated elements of variance between training and test samples. Instead, most tested classifiers using hold-outs or resampling (usually cross-validation) from the same population used in training. The present study evaluated a wide range of classifiers on NMR and mass spectra of plant and food materials, from four projects with different data properties (e.g., different numbers and prevalence of classes) and classification objectives. Use of cross-validation was found to be optimistic relative to EV on samples of different provenance to the training set (e.g., different genotypes, different growth conditions, different seasons of crop harvest). For classifier evaluations across the diverse tasks, we used ranks-based non-parametric comparisons, and permutation-based significance tests. Although latent variable methods (e.g., PLSDA) were used in 64% of the surveyed papers, they were among the less successful classifiers in EV, and orthogonal signal correction was counterproductive. Instead, the best EV performances were obtained with machine learning schemes that coped with the high dimensionality (914-1898 features). Random forests confirmed their resilience to high dimensionality, as best overall performers on the full data, despite being used in only 4.5% of the surveyed papers. Most other machine learning classifiers were improved by a feature selection filter (ReliefF), but still did not out-perform random forests.

Advances of vibrational spectroscopic methods in phytomics and bioanalysis

During the last couple of years great advances in vibrational spectroscopy including near-infrared (NIR), mid-infrared (MIR), attenuated total reflection (ATR) and imaging and also mapping techniques could be achieved. On the other hand spectral treatment features have improved dramatically allowing filtering out relevant information from spectral data much more efficiently and providing new insights into the biochemical composition. These advances offer new possible quality control strategies in phytomics and enable to get deeper insights into biochemical background in terms of medicinal relevant questions. It is the aim of the present article pointing out the technical and methodological advancements in the NIR and MIR field and to demonstrate the individual methods efficiency by discussing distinct selected applications.