Study on the Genetic Mechanism of Carbonate Rock Type Hot Mineral Water-A Case Study of Diaozhen, Jinan.

Geothermal resources are one of the most valuable resources in renewable energy because of their advantages of green environmental protection, stability, and reliability. Carbonate rock type geothermal reservoirs have great research significance. Carbonate rock type geothermal resources are abundant in the Shandong area. In this paper, we take the carbonate-type geothermal reservoir in the Diaozhen area of Jinan City as the research object, analyze the regional geothermal geological conditions, and identify the geological structure. Through physical logging exploration, hydrochemical analysis, isotope testing, and drilling exploration, we reveal the geothermal genesis mechanism and construct the genetic model of the carbonate geothermal system. The results show that Diaozhen area belongs to a low-temperature geothermal field and weak open karst thermal reservoir and that the reservoir is mainly Ordovician Majiagou group limestone. The thermal insulation caprock is the overlying Quaternary and Neogene strata with a cumulative thickness of 1376 m. The results of geophysical exploration wells and drilling data verify that the Mingshui fracture is seen around 1630-1645m, and the diorite intrusion is seen at 1610m. The Mingshui fracture connects the deep and shallow aquifers and is a geothermal fluid migration channel. The geothermal water in the Diaozhen area is mainly from the recharge of atmospheric precipitation, with a rich ion content and easy enrichment of trace elements. The regional thermal reservoir is mainly recharged by the deep circulation lateral runoff of Ordovician karst water. After long-distance deep circulation migration, groundwater continuously absorbs heat from the surrounding rock and is heated to geothermal raw water in the deep part. Deep geothermal water rises along the water-conducting fracture and mixes with shallow cold water to form shallow, low-temperature geothermal water.

Resting cell formation in the marine diatom Thalassiosira pseudonana.

Resting cells represent a survival strategy employed by diatoms to endure prolonged periods of unfavourable conditions. In the oceans, many diatoms sink at the end of their blooming season and therefore need to endure cold and dark conditions in the deeper layers of the water column. How they survive these conditions is largely unknown. We conducted an integrative analysis encompassing methods from histology, physiology, biochemistry, and genetics to reveal the biological mechanism of resting-cell formation in the model diatom Thalassiosira pseudonana. Resting-cell formation was triggered by a decrease in light and temperature with subsequent catabolism of storage compounds. Resting cells were characterised by an acidic and viscous cytoplasm and altered morphology of the chloroplast ultrastructure. The formation of resting cells in T. pseudonana is an energy demanding process required for a biophysical alteration of the cytosol and chloroplasts to endure the unfavourable conditions of the deeper ocean as photosynthetic organisms. However, most resting cells (> 90%) germinate upon return to favorable growth conditions.

Construction of ecological network based on habitat risks identifying by points of interest: A case study of Wuhan Metropolitan Area.

Ecological network construction plays a key role in ecological restoration, which can effectively mitigate negative effects of habitat fragmentation on biodiversity. Here, we proposed an improved analytical framework for ecological network identification. Specifically, ecological sources were identified using a three-dimension indicator system in terms of form, quality and functions of habitats. Ecological resistance surfaces were determined based on the incorporation of points of interest data that could characterize human activities into habitat risk assessment (HRA) model, while ecological corridors were extracted using circuit theory approach. With Wuhan Metropolitan Area as a case, we explored the key points and structures of ecological network. Moreover, we compared the construction method of ecological resistance surface based on points of interest and HRA model with traditional methods that determined by land use types and by traditional HRA model, to validate the proposed framework. The results showed that the ecological source area of Wuhan Metropolitan Area was 15200 km2, the length of ecological corridor was 1956.68 km, and that there were 87 ecological "pinch points" and 67 ecological barrier points. Compared with traditional methods, the material circulation, network complexity, and ecological connectivity of the ecological network identified by the improved framework were significantly improved, with network closure, dot-line ratio, and network connectivity being increased by 61.5%, 28.1% and 28.7% on average. The identified ecological "pinch points" and barrier points could provide precise decision-making support for ecological restoration and conservation.

Visualizing chiral structures in cellulose nanocrystal films by a Mueller matrix microscope.

Visualizing chiral structures in solid materials is crucial but difficult in chiral analysis. The three-dimensional structures in the helicoidal nano-assemblies in cellulose nanocrystal (CNC) films were visualized using a Mueller matrix microscope (MMM). Optical analysis of the assembly of CNCs through structural reconstruction by optical simulation revealed the complex structures in CNC films.

Hierarchical nano-martensite-engineered a low-cost ultra-strong and ductile titanium alloy.

Due to the low thermal stability of crystallographic boundaries, the grain boundary engineering (GBE) manifests some limits to the fineness and types of microstructures achievable, while unique chemical boundary engineering (CBE) enables us to create a metallic material with an ultrafine hierarchically heterogeneous microstructure for enhancing the mechanical properties of materials. Here, using a low cost metastable Ti-2.8Cr-4.5Zr-5.2Al (wt.%) alloy as a model material, we create a high density of chemical boundaries (CBs) through the significant diffusion mismatch between Cr and Al alloying elements to architecture hierarchical nano-martensites with an average thickness of ~20 nm. For this metastable titanium alloy, the significantly enhanced yield strength originates from dense nano-martensitic interface strengthening, meanwhile the large ductility is attributed to the multi-stage strain hardening of hierarchical 3D α'/ß lamellae assisted by equiaxed primary α (αp) nodules. The hierarchical nano-martensite engineering strategy confers our alloy a desired combination of strength and ductility, which can potentially be applied to many transformable alloys, and reveal a new target in microstructural design for ultrastrong-yet-ductile structural materials.

Modifying Anti-Compression Property and Water-Soluble Ability of Polyglycolic Acid via Melt Blending with Polyvinyl Alcohol.

Biodegradable polymeric materials have become the most attractive research interest in recent years and are gradually widely used in various fields in the case of environmental pollution. In this paper, binary blends, mainly including varying contents of polyglycolic acid (PGA) and poly(vinyl alcohol) (PVA), were prepared via a melt compounding strategy. The ethylene-methyl acrylate-glycidyl methacrylate (EMA-GMA) was employed as the compatibilizer to improve the compatibility between the PGA and PVA and the polyolefin elastomer (POE) was used as toughening agent. The anti-compression property and water-soluble ability of the blends were particularly studied to explore their potential application in an oil/gas exploitation field. Special attentions were paid to the evolution of the water-soluble ability of PGAX with the PVA concentration. Furthermore, isothermal shear measurement and thermogravimetric analysis were performed to evaluate the thermal stability of PGA and PGA blends (PGAX) during melt processing. The results showed that the incompatibility between PGA and PVA largely deteriorated the mechanical property, i.e., anti-compression strength, leading to fragile characteristics under a lower compressive load for the PGAX samples with varied contents of PVA. The presence of PVA and EMA-GMA greatly enhanced the viscoelasticity of the PGA melt, showing an increased storage modulus and viscosity at a low shear frequency; however, the thermal instability of PGAX was intensified owing to the greater ease of thermal degradation of PVA than that of PGA. Meanwhile, the water-soluble ability of PGAX was improved due to the high water dissolution of PVA, which played the role as a sacrificial material. The purpose of this work is to pursue an effective modification for PGA processing and application via melt blending.

A New Method for Rapid Subcellular Localization and Gene Function Analysis in Cotton Based on Barley Stripe Mosaic Virus.

The difficulty of genetic transformation has restricted research on functional genomics in cotton. Thus, a rapid and efficient method for gene overexpression that does not rely on genetic transformation is needed. Virus-based vectors offer a reasonable alternative for protein expression, as viruses can infect the host systemically to achieve expression and replication without transgene integration. Previously, a novel four-component barley stripe mosaic virus (BSMV) was reported to overexpress large fragments of target genes in plants over a long period of time, which greatly simplified the study of gene overexpression. However, whether this system can infect cotton and stably overexpress target genes has not yet been studied. In this study, we verified that this new BSMV system can infect cotton through seed imbibition and systemically overexpress large fragments of genes (up to 2340 bp) in cotton. The target gene that was fused with GFP was expressed at a high level in the roots, stems, and cotyledons of cotton seedlings, and stable fluorescence signals were detected in the cotton roots and leaves even after 4 weeks. Based on the BSMV overexpression system, the subcellular localization marker line of endogenous proteins localized in the nucleus, endoplasmic reticulum, plasma membrane, Golgi body, mitochondria, peroxisomes, tonoplast, and plastids were quickly established. The overexpression of a cotton Bile Acid Sodium Symporter GhBASS5 using the BSMV system indicated that GhBASS5 negatively regulated salt tolerance in cotton by transporting Na+ from underground to the shoots. Furthermore, multiple proteins were co-delivered, enabling co-localization and the study of protein-protein interactions through co-transformation. We also confirmed that the BSMV system can be used to conduct DNA-free gene editing in cotton by delivering split-SpCas9/sgRNA. Ultimately, the present work demonstrated that this BSMV system could be used as an efficient overexpression system for future cotton gene function research.

A Methodological Advance of Tobacco Rattle Virus-Induced Gene Silencing for Functional Genomics in Plants.

As a promising high-throughput reverse genetic tool in plants, virus-induced gene silencing (VIGS) has already begun to fulfill some of this promise in diverse aspects. However, review of the technological advancements about widely used VIGS system, tobacco rattle virus (TRV)-mediated gene silencing, needs timely updates. Hence, this article mainly reviews viral vector construction, inoculation method advances, important influential factors, and summarizes the recent applications in diverse plant species, thus providing a better understanding and advice for functional gene analysis related to crop improvements.

Highly sensitive and selective colorimetric sensor for thiocyanate based on electrochemical oxidation-assisted complexation reaction with Gold nanostars etching.

In this work, we developed an electrochemical oxidation-assisted complexation strategy for highly sensitive and selective detection of thiocyanate (SCN-). Gold nanostars (AuNSs) with uniform and sharp tips were first prepared, and we found they can be quickly etched to gold nanoparticles (AuNPs) under electrochemical oxidation with the existence of halide and halogen-like ions. Through introducing SCN--selective molecule: zinc phthalocyanine (ZnPc), the fabricated ZnPc-AuNSs/ITO electrode can rapidly and selectively response to SCN- under electrochemical oxidation, manifesting as a noticeable change in color from navy blue to red. Thus SCN- concentration can be easily reflected. The wide wavelength tuning range of AuNSs to AuNPs make the ZnPc-AuNSs/ITO sensor obtain a much wider detection range for SCN- (10 nM to 80 mM) than most other reported studies. In addition, the detection limit is as low as 3 nM. It renders the sensor to be easily used in much diluted matrixes, which can further lower the interference. We further applied the colorimetric sensor to SCN- detection in wastewater and milk, excellent performance was obtained. The proposed electrochemical oxidation-assisted complexation strategy will have good promise in developing colorimetric sensors with high selectivity and wide detection range, and will display more useful application in environmental monitoring.

Analysis of CRISPR-Cas System in Streptococcus thermophilus and Its Application.

CRISPR-Cas (Clustered regularly interspaced short palindromic repeats-CRISPR associated proteins) loci, which provide a specific immunity against exogenous elements, are hypervariable among distinct prokaryotes. Based on previous researches, this review focuses on concluding systematical genome editing protocols in Streptococcus thermophilus. Firstly, its protocols and optimized conditions in gene editing are introduced. What's more, classification and diversity analyses of S. thermophilus CRISPR-Cas benefit the further understanding of evolution relationship among Streptococcus. Ability of its foreign segment integration and spacer source analyses also indicate a new direction of phage resistance. Above all, all of these point out its potential to be regarded as another model system other than type II CRISPR-Cas in Streptococcus pyogenes.

New advances in exopolysaccharides production of Streptococcus thermophilus.

Streptococcus thermophilus is the most important thermophilic dairy starter, and is widely used in the dairy industry. Streptococcus thermophilus exopolysaccharides received wide attention over recent decades, because they can improve the properties of the dairy product and confer beneficial health effects. The understanding of the regulatory and biosynthetic mechanisms of EPS will improve the EPS biosynthesis, increase the productivity of EPSs, and develop EPSs with desirable properties. The structure of EPSs is the focus of this study. Revealing the structure-function relationship can lead to increase the knowledge base and from there to increased research of EPS. The EPS yield is a key limiting factor in the research and utilization of EPS. In the present review, biosynthetic pathways and genetics of S. thermophilus EPSs were described and reviewed. At the same time, functional properties and applications of EPS, and strategies for enhancement of EPS production are discussed.