Photosynthetic Conversion of CO2 Into Pinene Using Engineered Synechococcus sp. PCC 7002

Metabolic engineering of cyanobacteria has received much attention as a sustainable strategy to convert CO2 to various longer carbon chain fuels. Pinene has become increasingly attractive since pinene dimers contain high volumetric energy and have been proposed to act as potential aircraft fuels. However, cyanobacteria cannot directly convert geranyl pyrophosphate into pinene due to the lack of endogenous pinene synthase. Herein, we integrated the gene encoding Abies grandis pinene synthase into the model cyanobacterium Synechococcus sp. PCC 7002 through homologous recombination. The genetically modified cyanobacteria achieved a pinene titer of 1.525 ± 0.l45 mg L−1 in the lab-scale tube photobioreactor with CO2 aeration. Specifically, the results showed a mixture of α- and β-pinene (∼33:67 ratio). The ratio of β-pinene in the product was significantly increased compared with that previously reported in the engineered Escherichia coli. Furthermore, we investigated the photoautotrophic growth performances of Synechococcus overlaid with different concentrations of dodecane. The work demonstrates that the engineered Synechococcus is a suitable potential platform for β-pinene production.

Expression of mTOR/70S6K signaling pathway in melanoma cancer cell and the effects of dacarbazine and metformin

Background: Melanoma, also known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin but may rarely occur in the mouth, intestines or, eye. The study aimed to examine the expression of the mammalian target of rapamycin (mTOR)/70S6K signaling pathway in melanoma cancer. Methods: The B16F10 cell line treated with dacarbazine IC50 and different concentrations of metformin (0.5, 2, and 8 mM) for 24 hr and mTOR and 70S6k proteins expression was examined by western blotting. Cell viability was measured by MTT assay. Results: Western blot analysis showed that after different concentra¬tions of metformin and dacarbazine treatments, the mTOR and 70S6K protein expression significantly (P<0.05) decreased. Conclusion: Metformin-induced repression of mTOR/70S6k axis activity disrupts B16F10 growth. Thus, we believe that combination therapy may be a suitable potential therapeutic target for melanoma cancer.

Quantum corrections to slow-roll inflation: scalar and tensor modes

Inflation is often described through the dynamics of a scalar field, slow-rolling in a suitable potential. Ultimately, this inflaton must be identified with the expectation value of a quantum field, evolving in a quantum effective potential. The shape of this potential is determined by the underlying tree-level potential, dressed by quantum corrections from the scalar field itself and the metric perturbations. Following [1], we compute the effective scalar field equations and the corrected Friedmann equations to quadratic order in both scalar field, scalar metric and tensor perturbations. We identify the quantum corrections from different sources at leading order in slow-roll, and estimate their magnitude in benchmark models of inflation. We comment on the implications of non-minimal coupling to gravity in this context.

Natural bio-based monomers for biomedical applications: a review

In recent years, synthetic and semi-synthetic polymer materials have been widely used in various applications. Especially concerning biomedical applications, their biocompatibility, biodegradability, and non-toxicity have increased the interest of researchers to discover and develop new products for the well-being of humanity. Among the synthetic and semi-synthetic materials, the use of natural bio-based monomeric materials presents a possible novel avenue for the development of new biocompatible, biodegradable, and non-toxic products. The purpose of this article is to review the information on the role of natural bio-based monomers in biomedical applications. Increased eco-friendliness, biocompatibility, biodegradability, non-toxicity, and intrinsic biological activity are some of the attributes which make itaconic, succinic, citric, hyaluronic, and glutamic acids suitable potential materials for biomedical applications. Herein, we summarize the most recent advances in the field over the past ten years and specifically highlight new and interesting discoveries in biomedical applications. Graphical abstract Natural origin acid-based bio-monomers for biomedical applications

Ecto-GPR37: a potential biomarker for Parkinson’s disease

Objective α-Synuclein has been studied as a potential biomarker for Parkinson’s disease (PD) with no concluding results. Accordingly, there is an urgent need to find out reliable specific biomarkers for PD. GPR37 is an orphan G protein-coupled receptor that toxically accumulates in autosomal recessive juvenile parkinsonism. Here, we investigated whether GPR37 is upregulated in sporadic PD, and thus a suitable potential biomarker for PD. Methods GPR37 protein density and mRNA expression in postmortem substantia nigra (SN) from PD patients were analysed by immunoblot and RT-qPCR, respectively. The presence of peptides from the N-terminus-cleaved domain of GPR37 (i.e. ecto-GPR37) in human cerebrospinal fluid (CSF) was determined by liquid chromatography-mass spectrometric analysis. An engineered in-house nanoluciferase-based immunoassay was used to quantify ecto-GPR37 in CSF samples from neurological control (NC) subjects, PD patients and Alzheimer’s disease (AD) patients. Results GPR37 protein density and mRNA expression were significantly augmented in sporadic PD. Increased amounts of ecto-GPR37 peptides in the CSF samples from PD patients were identified by mass spectrometry and quantified by the in-house ELISA method. However, the CSF total α-synuclein level in PD patients did not differ from that in NC subjects. Similarly, the cortical GPR37 mRNA expression and CSF ecto-GPR37 levels in AD patients were also unaltered. Conclusion GPR37 expression is increased in SN of sporadic PD patients. The ecto-GPR37 peptides are significantly increased in the CSF of PD patients, but not in AD patients. These results open perspectives and encourage further clinical studies to confirm the validity and utility of ecto-GPR37 as a potential PD biomarker.

The Evaluation of the Potential of Developing Tourism in Kysuce Region

Tourism is an industry with a strong long-term potential of becoming one of the key industries in securing the country’s economic growth. Tourists are nowadays interested in not only getting to know the cultural-historical peculiarities, but also the way of life and cultural traditions of the inhabitants of the individual regions. Kysuce region is characterised by scattered settlement, which used to be a significant type of settlement in remote and inaccessible parts of the area in the past. Nowadays, however, the majority of the objects of the scattered settlement either serve as holiday chalets or are uninhabited.The aim of this paper is to evaluate the recreational potential of tourism in Kysuce region. Based on the established methodology, the individual villages were divided into five categories: areas with less suitable potential of tourism development (PTD), areas with suitable PTD, areas with quality PTD, areas with PTD of high quality and areas with the most significant PTD. These categories have been established based on the point evaluation of the potential of input indicators – natural potential, cultural-historical potential, recreational infrastructure and environmental infrastructure. The most significant PTD in the monitored area is the village of Oščadnica (279 points), and the villages of Horný Vadičov (231 points), Raková (224 points) and Nová Bystrica (219.5 points) were evaluated as the areas with PTD of high quality. Agro-tourism in this region is, however, the least developed, despite the location of the region being very favourable for such an activity. Its development could lower unemployment and offer a source of income of the inhabitants, or reduce movement of the inhabitants into other regions of Slovakia. Subsequently, the character of the landscape with all its key functions for sustaining the quality of the environment could be preserved.

Antifungal activity of methylxanthines based on their properties

Wood materials for construction purposes can be attacked by various wood-destroying fungi. An ideal wood-preserving substance is supposed to be environment- and health-friendly. For this reason, the effects of the most relevant and non-toxic methylxanthines, such as caffeine and its metabolites theobromine and theophylline, on fungal growth, together with their degradability related to their properties were analyzed in this study. Agar tests with four wood-destroying fungal species (Serpula lacrymans, Coniophora puteana, Gleophyllum sepiarium, and Trametes versicolor) were performed after 28 days of substance exposure. Caffeine exhibited a 100% inhibitive effect on fungal growth, contrary to theobromine, which was not effective in that respect. Theophylline exhibited variable effects on the analyzed fungi. The analysis of degradability indicated the persistence of caffeine and theobromine, but theophylline was degraded up to 34%. The relation of toxicity to chemical structure of studied methylxanthines indicated the dipole moment and lipophilicity as important parameters affecting the antifungal properties. Both caffeine and theophylline are suitable potential candidates for antifungal active substances.

Chemical Diversity and Prediction of Potential Cultivation Areas of Cistanche Herbs

Owing to hostile growth environments and increasing related production, Cistanche plants have decreased in number. The aim of the present study was to evaluate the quality of and to predict potential suitable regions for two official species and two nonofficial species (C. salsa and C. sinensis) by high-performance liquid chromatography and the MaxEnt model. The results indicated that 2′-acetylacteoside was present only in C. deserticola. The compound can be used as a potential chemical marker to discriminate C. deserticola from the three other Cistanche plants. Anthocyanin A and carotenoid F were the common constituents of the two official species only and can thus be used as chemical markers to differentiate between official and nonofficial species. The prediction results of a potentially suitable distribution indicated that C. sinensis has much wider regions for potential distribution than the other species. Finally, the echinacoside content in C. deserticola was significantly different between the two suitable potential distributions, and the contents of samples from Inner Mongolia were significantly higher than those from Gansu Province. This is the first application of the combination of the contents of chemical components and the results of MaxEnt models for the quality assessment of herbal medicine. Our results may provide a reference for the sustainable utilization of endangered Cistanche species.