Brønsted Acid-Catalyzed Intramolecular Tandem Double Cyclization of γ-Hydroxy Acetylenic Ketones with Alkynes into Naphtho[1,2-]furan-3-ones.

A metal-free and atom-economic route for the synthesis of naphtho[1,2-]furan-3-ones has been realized via -TsOH·HO-catalyzed intramolecular tandem double cyclization of γ-hydroxy acetylenic ketones with alkynes in formic acid. The benzene-linked furanonyl-ynes are the key intermediates obtained by the scission/recombination of C-O double bonds. Further, the structural modifications of the representative product were implemented by reduction, demethylation, substitution, and [5 + 2]-cycloaddition.

Metformin improves sheep sperm cryopreservation via vitalizing the AMPK pathway.

Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) is a key regulator of sperm function and physiological metabolism. Metformin, an inexpensive and effective antioxidant, is known to play an important role in the activation of AMPK. Therefore metformin has potential to improve sperm cryopreservation.

Visualised genotyping assay with oral swabs in a closed tube by nested invasive reaction assisted with gold nanoparticle probes.

Single nucleotide polymorphism (SNP) typing is crucial for drug dosage and disease progression. Therefore, a simple and convenient genotyping assay is essential for personalised medicine. Herein, we developed a non-invasive, closed-tube, and visualised method for genotyping.

Recent advances in isolation, identification, and culture of mammalian spermatogonial stem cells.

Continuous spermatogenesis depends on the self-renewal and differentiation of spermatogonial stem cells (SSCs). SSCs, the only male reproductive stem cells that transmit genetic material to subsequent generations, possess an inherent self-renewal ability, which allows the maintenance of a steady stem cell pool. SSCs eventually differentiate to produce sperm.

[Analysis of a Pollution Process in the Beijing-Tianjin-Hebei Region Based on Satellite and Surface Observations].

The air pollution control of the Beijing-Tianjin-Hebei region (BTH region) is gradually moving toward regional joint mode. Remote sensing technology can be used to realize real-time dynamic monitoring over a wide range of space and ground-based monitoring can obtain accurate point information. Combining satellite with ground-based data, the formation and dissipation of pollution can be traced in three dimensions.

The FATZO mouse, a next generation model of type 2 diabetes, develops NAFLD and NASH when fed a Western diet supplemented with fructose.

Background: Metabolic disorders such as insulin resistance, obesity, and hyperglycemia are prominent risk factors for the development of non-alcoholic fatty liver disease (NAFLD)/steatohepatitis (NASH). Dietary rodent models employ high fat, high cholesterol, high fructose, methionine/choline deficient diets or combinations of these to induce NAFLD/NASH. The FATZO mice spontaneously develop the above metabolic disorders and type 2 diabetes (T2D) when fed with a normal chow diet.

Effect of addition of melatonin on liquid storage of ram semen at 4°C.

Adding a certain amount of antioxidants to semen extender has been shown to improve semen quality. The aim of present study was to elucidate whether the supplementation of melatonin to the Tris-based extender (CTR) could enhance the quality of ram spermatozoa during storage at 4°C. Ram semen samples were collected and diluted with CTR extender containing different concentrations (0, 0.

[Spatial and Temporal Distribution Characteristics and Fugitive Dust Emission of Building Sites in Beijing].

Because of the continuous expansion of the city and the evacuation of non-core functions, the city pattern of Beijing has gradually changed in recent years. Based on many construction projects, building sites are widely distributed within the city. Therefore, fugitive dust emission is an important factor affecting the air quality in Beijing.

Low-density point eating algorithm for surface reconstruction from dense scans.

We present a low-density point eating algorithm for surface reconstruction from dense scans. First, the density map for each scan is estimated and the boundary densities are down-weighted. Subsequently, the poorly scanned low-density overlapping points are eaten up based on a user-specified threshold.

Exposure-fusion-based dot-grid image acquisition and recognition for sheet metal strain analysis.

Dot-grid images are usually captured for grid strain analysis during sheet metal forming. Due to the strong reflective characteristic of the metallic surfaces, the recorded dot-grid images often have poor quality, low positioning accuracy, and low recognition rate. Therefore, an exposure-fusion-based dot-grid image acquisition and recognition approach is proposed.

Catalog of insect type specimens preserved at the Kunming Institute of Zoology, Chinese Academy of Science with corrections of some specimens.

This article presents a list of insect types preserved in Kunming Natural History Museum of Zoology (KNHMZ). As of March, 2015, 3 412 type specimens belonging to 266 species/subspecies of 37 families in 9 orders (Odonata, Isoptera, Mantodea, Orthoptera, Hemiptera, Coleoptera, Diptera, Hymenoptera and Lepidoptera) are included. Information corrections of some specimens are provided in this article.

Integrating novel chemical weapons and evolutionarily increased competitive ability in success of a tropical invader.

The evolution of increased competitive ability (EICA) hypothesis and the novel weapons hypothesis (NWH) are two non-mutually exclusive mechanisms for exotic plant invasions, but few studies have simultaneously tested these hypotheses. Here we aimed to integrate them in the context of Chromolaena odorata invasion. We conducted two common garden experiments in order to test the EICA hypothesis, and two laboratory experiments in order to test the NWH.

[Ecological risk assessment of human activity of rapid economic development regions in southern Jiangsu, China: a case study of Dantu District of Zhenjiang City].

This article investigated the spatiotemporal variation of landscape ecological risk in Dantu District of Zhenjiang City with statistical method based on the ETM remote sensing data in 2000 and 2005, and the TM remote sensing data in 2010, and quantitative index of regional ecological risk assessment was established with the employment of landscape index, so as to enhance the ecosystem management, prevent and reduce the regional ecological risk in southern Jiangsu with rapid economic development. The results showed that the fragmentations, divergence, and ecological losses of natural landscape types, such as forestland, wetland, waters, etc., were deteriorated with the expansion of built-up lands from 2000 to 2010.

A highly selective ratiometric fluorescent chemosensor for Cd2+ ions.

A phenanthroxazole-based fluorescent sensor for Cd(2+) has been developed. Of particular significance is the specific ratiometric response of the sensor toward Cd(2+) without interference from other biologically important metal ions including Zn(2+). The test paper made of this sensor exhibits both absorption and fluorescent color changes when exposed to Cd(2+) aqueous solution.

A highly selective and sensitive luminescent chemosensor for Zn2+ ions based on cyclometalated platinum(II) complexes.

A novel luminescent Zn(2+) ions chemosensor, a cyclometalated platinum(II) bipyridyl acetylide complex, was designed. Of particular significance is that it shows a high sensitivity towards Zn(2+) ions without interference from other biologically important cations in acetonitrile. The tautomerization of amide favors detecting Zn(2+) ions among other HTM (heavy and transition metal) ions in aqueous systems.