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This study aims to analyze the length polymorphisms in sequence-tagged-site (STS) sY1291 of the Y chromosome in Vietnamese men of infertile couples. All 322 DNA samples were amplified with the sY1291 primer by the quantitative fluorescent polymerase chain reaction (QF-PCR) assay. DNA sequencing technique was employed to evaluate the accuracy of QF-PCR results. The study showed 273 out of 322 DNA samples had the presence of STS sY1291, accounted for 84.78%. The QF-PCR results showed that there were various lengths in STS sY1291: 507 bp, 512 bp, 523 bp and 527 bp. The most prevalent length in STS sY1291 was 507 bp (87.5%), the others were 512 bp (4.8%), 523 bp (4.8%) and 527 bp (2.9%). We found that the observed length polymorphisms derived from differences in the number of mononucleotide Thymine (T) repeats in its structure. It stretched from 22 T to 39 T. DNA sequencing results identified that the number of mononucleotide T repeats causes these polymorphisms. However, the pair-wise alignment between the obtained and reference sequence was 77%. It can be seen that the length polymorphisms in STS sY1291 observed in QF-PCR results was accurate but it is still difficult to sequence fragments with mononucleotide repeats.

Development of noble-metal single atomic site catalysts with high metal loading is highly required for many important chemical reactions but proves to be very challenging. Herein, we report a Na2CO3 salt-assisted one-pot pyrolysis strategy from EDTA–Pt complex to N-doped graphene with isolated Pt single atomic sites (Pt-ISA/NG) with Pt loading up to 5.3 wt %. The X-ray absorption fine structure analysis and spherical aberration-correction electron microscopy demonstrate an atomic dispersion of single Pt species on graphene support and stabilized by nitrogen in Pt–N4 structure. The Pt-ISA/NG catalyst exhibits high catalytic activity and reusability for anti-Markovnikov hydrosilylation of various terminal alkenes with industrially relevant tertiary silanes under mild conditions. In hydrosilylation of 1-octene, the Pt-ISA/NG catalyst delivers an overall turnover frequency of 180 h–1, which is a 4-fold enhancement compared with commercial Pt/C.

The ever-growing market demands for lithium ion batteries have stimulated numerous research efforts aiming at the exploration of novel electrode materials with higher capacity and long-term cycling stability. Two-dimensional (2D) nanomaterials and their heterostructures are an intense area of study and promise great potential in electrochemical lithium storage owing to their unique properties that result from structural planar confinement. Here we report a microwave chemistry strategy to integrate ultrathin SnO2 nanosheets into graphene layer to construct surface-to-surface 2D heterostructured architectures, which can provide unique structural planar confinement for highly reversible electrochemical lithium storage. The as-synthesized 2D SnO2/graphene heterostructures can exhibit high reversible capacity of 688.5 mA h g−1 over 500 cycles with excellent long-term cycling stability and good rate capability when used as anode materials for lithium ion batteries. The present work definitely reveals the advantages of 2D heterostructures featured with a surface-to-surface stack between two different nanosheets in energy storage and conversion devices.

The emergence and establishment of new techniques for material fabrication are of fundamental importance in the development of materials science. Thus, we herein report a general synthetic strategy for the preparation of monolayer graphene. This novel synthetic method is based on the direct solid-state pyrolytic conversion of a sodium carboxylate, such as sodium gluconate or sodium citrate, into monolayer graphene in the presence of Na2CO3. In addition, gram-scale quantities of the graphene product can be readily prepared in several minutes. Analysis using Raman spectroscopy and atomic force microscopy clearly demonstrates that the pyrolytic graphene is composed of a monolayer with an average thickness of ∼0.50 nm. Thus, the present pyrolytic conversion can overcome the issue of the low monolayer contents (i.e., 1 wt.%–12 wt.%) obtained using exfoliation methods in addition to the low yields of chemical vapor deposition methods. We expect that this novel technique may be suitable for application in the preparation of monolayer graphene materials for batteries, supercapacitors, catalysts, and sensors.

Ultrathin and holey two-dimensional (2D) nanosheets are attracting extraordinary attention because of their unprecedented properties. In spite of tremendous progress on the synthesis of the 2D ultrathin nanosheets and research on their energy storage properties, up to now, the utilization of 2D holely nanosheets as cathodes remains clearly limited because of the grain growth and structural destruction. Herein, we rationally designed a general morphology-inheritance strategy to produce 2D ultrathin holey nanosheets as cathodes via a simple and scalable microwave-assisted approach. In this study, the 2D ultrathin nanosheet precursors were facilely synthesized and then, lithium and other sources were implemented to prepare ultrathin and holey 2D nanosheet cathodes (LiCoO2, LiNi0.8Co0.15Al0.05O2, LiNi0.8Co0.1Mn0.1O2, LiNi0.6Co0.2Mn0.2O2, and LiNi0.5Co0.2Mn0.3O2) through a simple solid-state reaction. The as-synthesized holey 2D cathodes present ultrahigh specific capacities, outstanding rate capability, and excellent cycle life, which are attributed to the abundant electrochemical active sites, facile interfacial transfer, and reduced diffusion distance provided by the unique hierarchical ultrathin 2D nanosheet structure with abundant atypical holes.

In recent years, various non-precious metal electrocatalysts for the oxygen reduction reaction (ORR) have been extensively investigated. The development of an efficient and simple method to synthesize non-precious metal catalysts with ORR activity superior to that of Pt is extremely significant for large-scale applications of fuel cells. Here, we develop a facile, low-cost, and large-scale synthesis method for uniform nitrogen-doped (N-doped) bamboo-like CNTs (NBCNT) with Co nanoparticles encapsulated at the tips by annealing a mixture of cobalt acetate and melamine. The uniform NBCNT shows better ORR catalytic activity and higher stability in alkaline solutions as compared with commercial Pt/C and comparable catalytic activity to Pt/C in acidic media. NBCNTs exhibit outstanding ORR catalytic activity due to high defect density, uniform bamboo-like structure, and the synergistic effect between the Co nanoparticles and protective graphitic layers. This facile method to synthesize catalysts, which is amenable to the large-scale commercialization of fuel cells, will open a new avenue for the development of low-cost and high-performance ORR catalysts to replace Pt-based catalysts for applications in energy conversion.

In this work we propose a novel idea of using thermoelectric material in lithium ion batteries. The reason behind this idea is to improve the efficiency of batteries especially when heat dissipation and exothermic reaction of cathode and anode with the electrolyte at higher temperatures restricts their continuous operation due to thermal runaway. In order to execute this idea we develop a new synthetic technique for fabrication of Bi 2 Se 3 (thermoelectric material) and also compare it's efficiency by preparing this material by existing synthetic technique. Charge/discharge comparison of both the samples indicate that the synthesis technique has a profound effect on electrochemical performance. Bismuth selenide (Bi 2 Se 3 ) is intentionally selected for this purpose. Bi 2 Se 3 rectangular nanosheets (BRNS) with thicknesses of 200–500 nm are synthesized by a simple thermochemical method in which we use bismuth and selenium powders as precursors. Self assembled nanosheets (SANS) in spherical shape are prepared by conventional hydrothermal technique. Charge discharge experiments show that BRNS synthesized with this technique have reasonable performance as compared to nanosheets synthesized by conventional hydrothermal technique. It shows that first discharge capacity is up to 725.6 mAh g −1 for BRNS and 419.6 mAh g −1 for SANS.