160 research outputs found
Control of potato late blight by caraway oil in organic farming
Caraway (Carum carvi) seeds contain biologically active essential oils, which have shown potential in controlling Phytophthora infestans (P.i.). An attempt is being made to develop a P.i. control strategy for organic farming based on caraway oil
Biologically active Phytophthora mating hormone prepared by catalytic asymmetric total synthesis
A Phytophthora mating hormone with an array of 1,5-stereogenic centers has been synthesized by using our recently developed methodology of catalytic enantioselective conjugate addition of Grignard reagents. We applied this methodology in a diastereo- and enantioselective iterative route and obtained two of the 16 possible stereoisomers of Phytophthora hormone α1. These synthetic stereoisomers induced the formation of sexual spores (oospores) in A2 mating type strains of three heterothallic Phytophthora species, P. infestans, P. capsici, and P. nicotianae but not in A1 mating type strains. The response was concentration-dependent, and the oospores were viable. These results demonstrate that the biological activity of the synthetic hormone resembles that of the natural hormone α1. Mating hormones are essential components in the sexual life cycle of a variety of organisms. For plant pathogens like Phytophthora, sexual reproduction is important as a source of genetic variation. Moreover, the thick-walled oospores are the most durable propagules that can survive harsh environmental conditions. Sexual reproduction can thus greatly affect disease epidemics. The availability of synthetic compounds mimicking the activity of Phytophthora mating hormone will be instrumental for further unravelling sexual reproduction in this important group of plant pathogens.
ALADIN is Required for the Production of Fertile Mouse Oocytes
Asymmetric cell divisions depend on the precise placement of the spindle apparatus. In mammalian oocytes, spindles assemble close to the cell's center, but chromosome segregation takes place at the cell periphery where half of the chromosomes are expelled into small, nondeveloping polar bodies at anaphase. By dividing so asymmetrically, most of the cytoplasmic content within the oocyte is preserved, which is critical for successful fertilization and early development. Recently we determined that the nucleoporin ALADIN participates in spindle assembly in somatic cells, and we have also shown that female mice homozygously null for ALADIN are sterile. In this study we show that this protein is involved in specific meiotic stages, including meiotic resumption, spindle assembly, and spindle positioning. In the absence of ALADIN, polar body extrusion is compromised due to problems in spindle orientation and anchoring at the first meiotic anaphase. ALADIN null oocytes that mature far enough to be fertilized in vitro are unable to support embryonic development beyond the two-cell stage. Overall, we find that ALADIN is critical for oocyte maturation and appears to be far more essential for this process than for somatic cell divisions
Biotechnological production of γ-decalactone, a peach like aroma, by Yarrowia lipolytica
The request for new flavourings increases every year. Consumer perception that everything natural is better is causing an increase demand for natural aroma additives. Biotechnology has become a way to get natural products. γ-Decalactone is a peach-like aroma widely used in dairy products, beverages and others food industries. In more recent years, more and more studies and industrial processes were endorsed to cost-effect this compound production. One of the best-known methods to produce -decalactone is from ricinoleic acid catalyzed by Yarrowia lipolytica, a generally regarded as safe status yeast. As yet, several factors affecting -decalactone production remain to be fully understood and optimized. In this review, we focus on the aromatic compound -decalactone and its production by Y. lipolytica. The metabolic pathway of lactone production and degradation are addressed. Critical analysis of novel strategies of bioprocess engineering, metabolic and genetic engineering and other strategies for the enhancement of the aroma productivity are presented.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684)
Validation of the standardization framework SSTR-RADS 1.0 for neuroendocrine tumors using the novel SSTR‑targeting peptide [18F]SiTATE.
OBJECTIVES: Somatostatin receptor positron emission tomography/computed tomography (SSTR-PET/CT) using [68Ga]-labeled tracers is a widely used imaging modality for neuroendocrine tumors (NET). Recently, [18F]SiTATE, a SiFAlin tagged [Tyr3]-octreotate (TATE) PET tracer, has shown great potential due to favorable clinical characteristics. We aimed to evaluate the reproducibility of Somatostatin Receptor-Reporting and Data System 1.0 (SSTR-RADS 1.0) for structured interpretation and treatment planning of NET using [18F]SiTATE. METHODS: Four readers assessed [18F]SiTATE-PET/CT of 95 patients according to the SSTR-RADS 1.0 criteria at two different time points. Each reader evaluated up to five target lesions per scan. The overall scan score and the decision on peptide receptor radionuclide therapy (PRRT) were considered. Inter- and intra-reader agreement was determined using the intraclass correlation coefficient (ICC). RESULTS: The ICC analysis on the inter-reader agreement using SSTR-RADS 1.0 for identical target lesions (ICC ≥ 85%), overall scan score (ICC ≥ 90%), and the decision to recommend PRRT (ICC ≥ 85%) showed excellent agreement. However, significant differences were observed in recommending PRRT among experienced readers (ER) (p = 0.020) and inexperienced readers (IR) (p = 0.004). Compartment-based analysis demonstrated good to excellent inter-reader agreement for most organs (ICC ≥ 74%), except for lymph nodes (ICC ≥ 53%). CONCLUSION: SSTR-RADS 1.0 represents a highly reproducible and consistent framework system for stratifying SSTR-targeted PET/CT scans, even using the novel SSTR-ligand [18F]SiTATE. Some inter-reader variability was observed regarding the evaluation of uptake intensity prior to PRRT as well as compartment scoring of lymph nodes, indicating that those categories require special attention during further clinical validation and might be refined in a future SSTR-RADS version 1.1. CLINICAL RELEVANCE STATEMENT: SSTR-RADS 1.0 is a consistent framework for categorizing somatostatin receptor-targeted PET/CT scans when using [18F]SiTATE. The framework serves as a valuable tool for facilitating and improving the management of patients with NET. KEY POINTS: SSTR-RADS 1.0 is a valuable tool for managing patients with NET. SSTR-RADS 1.0 categorizes patients with showing strong agreement across diverse reader expertise. As an alternative to [68Ga]-labeled PET/CT in neuroendocrine tumor imaging, SSTR-RADS 1.0 reliably classifies [18F]SiTATE-PET/CT
Crystallographic and topological textures of biological materials and the resulting anisotropy of the mechanical properties
Cable-driven parallel robot for curtain wall module installation
A cable-driven parallel robot (CDPR) was developed for the installation of curtain wall modules (CWM). The research addressed the question of whether the CDPR was capable installing CWMs with sufficient accuracy while being competitive compared to conventional manual methods. In order to develop and test such a system, a conceptual framework that consisted of three sub-systems was defined. The tests, carried out in two close-to-real demonstration buildings, revealed an absolute accuracy of the CWM installation of 4 to 23 mm. The working time for installing a CWM was reduced to 0.51 h. The results also show that the system is competitive for a workspace greater than 96 m2 compared to conventional manual methods. However, improvements such as reducing the hours for setting up the CDPR on the one hand and achieving a faster and more robust MEE on the other hand will be still necessary in the future.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant
agreement No. 73251
Cognitive functioning in opioid-dependent patients treated with buprenorphine, methadone, and other psychoactive medications: stability and correlates
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Association of integrated biomarkers and progression-free survival prediction in patients with gastroenteropancreatic neuroendocrine tumors undergoing [177Lu]Lu-DOTA-TATE therapy
Integrated biomarkers that predict survival in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET) receiving peptide receptor radionuclide therapy (PRRT) are still limited. This study aims to identify predictors of progression-free survival (PFS) in patients with GEP-NET undergoing two cycles of PRRT. Methods: This single-center retrospective study included 178 patients with GEP-NET (G1 and G2) who received at least two consecutive cycles of PRRT with [177Lu]Lu-DOTA-TATE and underwent somatostatin receptor (SSTR)-PET/CT before and after therapy. At baseline, Krenning score (KS) > 2, clinical, pathological and laboratory parameters were collected and correlated to PFS. Survival predictors were analyzed using univariate and multivariate models. For goodness-of-fit analysis, the Akaike information criterion and Harrell concordance index were determined. To determine the impact on the regression model the Wald-Test was performed. Results: In univariate analysis, KS 3 (vs. KS 4; HR, 2.02; 95% CI, 1.27-3.22; p = 0.012), Ki-67 > 5 % (HR, 2.00; 95% CI, 1.31-3.04; p = 0.008), CgA > 200 ng/mL (HR, 1.77; 95% CI, 1.14-2.76; p = 0.027) and NSE > 35 ng/mL (HR, 2.37; 95% CI, 1.44-3.89; p < 0.008) were significantly associated with shorter PFS, with CgA providing the highest C-index (0.6). In multivariate analysis , KS 3 (vs. KS 4; HR, 1.94; 95% CI, 1.17-3.21; p = 0.01), CgA > 200 ng/mL (HR, 1.76; CI, 1.08-2.87; p = 0.024), NSE > 35 ng/mL (HR, 1.98; 95% CI, 1.17-3.36; p = 0.011), and Ki-67 > 5 % (HR, 1.89; 95% CI, 1.18-3.02; p = 0.008) were significantly associated with reduced PFS. Including KS into multivariate analysis significantly improved the Cox regression model performance, as shown by a reduction in Akaike Information Criterion (592/596) and an increase in concordance index (0.66/0.65). The Wald test for individual variables supported the significance of both Ki-67 (7.1) and KS (6.7) as independent predictors of PFS. Conclusions: NSE, CgA, KS and Ki-67 emerged as independent predictors of PFS in GEP-NET patients scheduled for two cycles of PRRT, thereby emphasizing the importance of integrated diagnostics including in- and ex-vivo biomarkers to identify high-risk individuals prone to disease progression
Regulation of Asymmetrical Cytokinesis by cAMP during Meiosis I in Mouse Oocytes
Mammalian oocytes undergo an asymmetrical first meiotic division, extruding half of their chromosomes in a small polar body to preserve maternal resources for embryonic development. To divide asymmetrically, mammalian oocytes relocate chromosomes from the center of the cell to the cortex, but little is known about the underlying mechanisms. Here, we show that upon the elevation of intracellular cAMP level, mouse oocytes produced two daughter cells with similar sizes. This symmetrical cell division could be rescued by the inhibition of PKA, a cAMP-dependent protein kinase. Live cell imaging revealed that a symmetrically localized cleavage furrow resulted in symmetrical cell division. Detailed analyses demonstrated that symmetrically localized cleavage furrows were caused by the inappropriate central positioning of chromosome clusters at anaphase onset, indicating that chromosome cluster migration was impaired. Notably, high intracellular cAMP reduced myosin II activity, and the microinjection of phospho-myosin II antibody into the oocytes impeded chromosome migration and promoted symmetrical cell division. Our results support the hypothesis that cAMP plays a role in regulating asymmetrical cell division by modulating myosin II activity during mouse oocyte meiosis I, providing a novel insight into the regulation of female gamete formation in mammals
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