Proband-independent haplotyping based on NGS-based long-read sequencing for detecting pathogenic variant carrier status in preimplantation genetic testing for monogenic diseases

Preimplantation genetic testing for monogenic diseases (PGT-M) can be used to select embryos that do not develop disease phenotypes or carry disease-causing genes for implantation into the mother’s uterus, to block disease transmission to the offspring, and to increase the birth rate of healthy newborns. However, the traditional PGT-M technique has some limitations, such as its time consumption, experimental procedural complexity, and the need for a complete family or reference embryo to construct the haplotype. In this study, proband-independent haplotyping based on NGS-based long-read sequencing (Phbol-seq) was used to effectively construct haplotypes. By targeting the mutation sites of single gene disease point mutations and small fragment deletion carriers, embryos carrying parental disease-causing mutations were successfully identified by linkage analysis. The efficiency of embryo resolution was then verified by classical Sanger sequencing, and it was confirmed that the construction of haplotype and SNP linkage analysis by Phbol-seq could accurately and effectively detect whether embryos carried parental pathogenic mutations. After the embryos confirmed to be nonpathogenic by Phbol-seq-based PGT-M and confirmed to have normal copy number variation by Phbol-seq-based PGT-A were transplanted into the uterus, gene detection in amniotic fluid of the implanted embryos was performed, and the results confirmed that Phbol-seq technology could accurately distinguish normal genotype embryos from genetically modified carrier embryos. Our results suggest that Phbol-seq is an effective strategy for accurately locating mutation sites and accurately distinguishing between embryos that inherit disease-causing genes and normal embryos that do not. This is critical for Phbol-seq-based PGT-M and could help more single-gene disease carriers with incomplete families, de novo mutations or suspected germline mosaicism to have healthy babies with normal phenotypes. It also helps to reduce the transmission of monogenic genetic diseases in the population

Sm, Nd doped BiFeO3 epitaxial film for photodetector with extremely large on-off current ratio

BiFeO3 is one of the star materials in the field of ferroelectric photovoltaic for its relatively narrow bandgap (2.2-2.7 eV) and better visible light absorption. However, a high temperature over 600 °C is indispensable in the usual BiFeO3 growth process, which may lead to impure phase, interdiffusion of components near the interface, oxygen vacancy and ferrous iron ions, which will result in large leakage current and greatly aggravate the ferroelectricity and photoelectric response. Here we prepared Sm, Nd doped epitaxial BiFeO3 film via a rapid microwave assisted hydrothermal process at low temperature. The Bi0.9Sm0.5Nd0.5FeO3 film exhibits narrow bandgap (1.35 eV) and photo response to red light, the on-off current ratio reaches over 105. The decrease in band gap and +2/+3 variable element doping are responsible for the excellent photo response. The excellent photo response performances are much better than any previously reported BiFeO3 films, which has great potential for applications in photodetection, ferroelectric photovoltaic and optoelectronic devices

Multifunctional sensors for respiration monitoring and antibacterial activity based on piezoelectric PVDF/BZT-0.5BCT nanoparticle composite nanofibers

In clinical practice, combining sensitive and efficient sensors that have antibacterial properties with masks is a convenient way to monitor vital signs. Therefore, developing flexible pressure sensors with high sensitivity and antibacterial properties is the key for such smart devices. In our work, poly (vinylidene fluoride) (PVDF) nanofibers (NFs) with a high piezoelectric phase were fabricated by electrospinning with an optimized spinning voltage and collecting roller speed. Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-0.5BCT) nanoparticles (NPs) synthesized by the hydrothermal method were introduced into PVDF NFs to improve their piezoelectric response to external strain. With 20 wt% 0.5BZT-BCT NPs, the PVDF/BZT-BCT fiber composite sensor showed an output voltage up to 6.37 V with superior sensitivity (0.24 V Kpa−1), a short response time (∼50 ms), good durability over a wide time range and a low detection limit (2.50 mg). The sensor was built in a mask that demonstrated high sensitivity in monitoring the respiratory rate as well as antimicrobial resistance to Echerichia coli (E. coli) and Staphylococcus aureus (S. aureus). Furthermore, this composite fiber sensor can also be applied for the detection of body movement. The multifunctional 0.5BZT-BCT/PVDF fiber composite sensor may find clinical applications

Temperature and frequency dependences of the electric properties of CLBO crystals

In this paper, CsLiB6O10 (CLBO) crystals were grown by top-seeded solution growth (TSSG) method using self-flux. The temperature and frequency dependences of the dielectric constant, dielectric loss, AC conductivity and impedance spectroscopy for different cuts CsLiB6O10 crystals were investigated, also temperature characteristics of the resonance frequency and electromechanical coupling were studied. The results show that (0 0 1)-plane of CsLiB6O10 crystal has the highest dielectric constant with a value of 109, highest AC conductivity and highest electromechanical coupling factor of about 17% at elevated temperature, these make CsLiB6O10 crystal excellent candidate for electrical application at elevated temperature. Also the anisotropy of electric properties has strong relationship with the crystal structure

Composition gradient (1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 film with improved dielectric, piezoelectric and ferroelectric temperature stability

© 2020 Lead-free (1-x)Ba(Ti0.8Zr0.2)O3-x(Ba0.7Ca0.3)TiO3 (BZT-BCT) possesses comparable piezoelectric constant with lead zirconate titanate (PZT), but its poor temperature electric performances stability and low Curie temperature limit its application. Here we designed composition graded BZT-BCT films with improved temperature stability of piezoelectric, ferroelectric, and dielectric performances over a wide temperature range, and the d33 reaches 21 pm/V with hysteresis loop even at 180 °C, which is far above the Curie temperature of BZT-BCT ceramic and BZT-0.5BCT film. The excellent temperature stability is ascribed to the lattice distortion and strain gradient in the grains caused by ions diffusion, and could suppress phase transition. This work could bring forward a feasible design for dielectric/piezoelectric/ferroelectric devices operating in harsh temperature environment

Thickness-dependent frictional behavior of topological insulator Bi2Se3 nanoplates

© 2020, Springer-Verlag GmbH Germany, part of Springer Nature. Two-dimensional Bi2Se3 TIs were recently found to be the most promising room-temperature topological insulators for its relatively large bulk gap, but its surface frictional response is little investigated. Here, we prepared single-crystalline Bi2Se3 nanoplates with a lateral dimension up to ~ 1 μm and a thickness of less than 200 nm via a simple polyol method, and the molecular structure and morphology were characterized in detail using different methods. The micro-frictional behavior of Bi2Se3 nanoplates with different thickness is inventively investigated with AFM technique. The atomic stick–slip friction stemming from periodic crystal lattice, and the larger friction force of thinner nanoplates is attributed to the larger adhesion force and enhanced energy dissipation. This work has, for the first time, built the link of the behavior of topological protected surface and mechanical friction behavior of Bi2Se3