Population genetic implications from sequence variation in four Y chromosome genes

Some insight into human evolution has been gained from the sequencing of four Y chromosome genes. Primary genomic sequencing determined gene SMCY to be composed of 27 exons that comprise 4,620 bp of coding sequence. The unfinished sequencing of the 5' portion of gene UTY1 was completed by primer walking, and a total of 20 exons were found. By using denaturing HPLC, these two genes, as well as DBY and DFFRY, were screened for polymorphic sites in 53-72 representatives of the five continents. A total of 98 variants were found, yielding nucleotide diversity estimates of 2.45 x 10(-5), 5. 07 x 10(-5), and 8.54 x 10(-5) for the coding regions of SMCY, DFFRY, and UTY1, respectively, with no variant having been observed in DBY. In agreement with most autosomal genes, diversity estimates for the noncoding regions were about 2- to 3-fold higher and ranged from 9. 16 x 10(-5) to 14.2 x 10(-5) for the four genes. Analysis of the frequencies of derived alleles for all four genes showed that they more closely fit the expectation of a Luria-Delbrück distribution than a distribution expected under a constant population size model, providing evidence for exponential population growth. Pairwise nucleotide mismatch distributions date the occurrence of population expansion to approximately 28,000 years ago. This estimate is in accord with the spread of Aurignacian technology and the disappearance of the Neanderthals.     

Hybrid BiOBr/UiO-66-NH2 composite with enhanced visible-light driven photocatalytic activity toward RhB dye degradation

Metal–organic framework (MOFs) based composites have received more research interest for photocatalytic applications during recent years. In this work, a highly active, visible light photocatalyst BiOBr/UiO-66-NH₂ hybrid composite was successfully prepared by introducing various amounts of UiO-66-NH₂ with BiOBr through a co-precipitation method. The composites were applied for the photocatalytic degradation of RhB (rhodamine B) dye. The developed BiOBr/UiO-66-NH₂ composites exhibited higher photocatalytic activity than the pristine material. In RhB degradation experiments the hybrid composite with 15 wt% of UiO-66-NH₂ shows degradation efficiency conversion of 83% within two hours under visible light irradiation. The high photodegradation efficiency of BUN-15 could be ascribed to efficient interfacial charge transfer at the heterojunction and the synergistic effect between BiOBr/UiO-66-NH₂. In addition, an active species trapping experiment confirmed that photo-generated hole⁺ and O₂⁻ radicals are the major species involved in RhB degradation under visible light.

Metal–organic framework (MOFs) based composites have received more research interest for photocatalytic applications during recent years.     

Novel N-doped ZrO2 with enhanced visible-light photocatalytic activity for hydrogen production and degradation of organic dyes

Two new types of N-doped ZrO₂ photocatalysts ZON and AZON have been synthesized using ethylenediamine as the nitrogen source by a facile and low-cost sol–gel method. The N-doped ZrO₂ samples have been characterized using various techniques including X-ray diffraction (XRD), UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL) and N₂ adsorption–desorption tests. The XRD analysis shows that the crystallinity of ZON samples calcined at 400–600 °C can be indexed to monoclinic ZrO₂; while the AZON samples calcined at 400–550 °C only show amorphous diffraction patterns. The UV-Vis response of both N-doped ZrO₂ samples can be extended to the visible light regime. The high resolution XPS spectra indicate that N element has been doped in the lattice of ZrO₂. Visible-light photocatalytic reactions using the N-doped ZrO₂ photocatalysts (i.e. ZON, AZON) calcined at 450 °C show the highest hydrogen production rate (2.12 mmol g⁻¹ h⁻¹) and best methylene orange degradation performance due to substitutional N-doping of the ZrO₂. The novel N-doped ZrO₂ materials are demonstrated to be very promising photocatalysts with enhanced visible-light photocatalytic activity. Our results provide useful insights into the development of novel photocatalytic materials for hydrogen production and degradation of organic wastes by narrowing the wide bandgap of semiconductors with high photocatalytic activity under UV-Vis light.

Two new types of N-doped ZrO₂ photocatalysts ZON and AZON have been synthesized using ethylenediamine as the nitrogen source by a facile and low-cost sol–gel method.     

N-Acetyl-l-leucine-polyethylenimine-mediated miR-34a delivery improves osteogenesis and bone formation in vitro and in vivo

Oral bone defects are difficult to treat. Recently, endogenous miR-34a was shown to be involved in bone anabolism. Clinical application of such microRNAs requires the inherent instability of microRNAs to be overcome by an efficient delivery system. In this study, we employed N-acetyl-l-leucine-modified polyethylenimine (N-Ac-l-Leu-PEI) as an miR-34a carrier and evaluated its delivery ability, transfection efficiency, cytotoxicity and whether it enhanced osteogenic differentiation and bone formation in vitro and in vivo. Stable N-Ac-l-Leu-PEI/miR-34a nanocomplexes were synthesized at a mass ratio of 4 and had a small size (190.34 nm), a low zeta potential (21.1 mV), a high transfection efficiency (69.39%) and no cytotoxicity in MG63 cells. N-Ac-l-Leu-PEI-mediated miR-34a delivery in vitro promoted ALP activity and expression of osteogenic differentiation markers, Runx2, SP7 and ColI to higher levels than those produced by Lipofectamine 2000-mediated delivery. N-Ac-l-Leu-PEI also achieved delivery of miR-34a in vivo to a local cranial bone defect area with miR-34a retaining the ability to initiate significant new bone formation 12 weeks post-implantation. This demonstrates the potential for N-Ac-l-Leu-PEI as a gene therapy vehicle for the regeneration of bone defects.

We employ N-acetyl-l-leucine-modified polyethylenimine as an miR-34a carrier and evaluate its delivery ability, transfection efficiency, cytotoxicity and whether it enhances osteogenic differentiation and bone formation in vitro and in vivo.     

Synergetic effects of bimetals in modified beta zeolite for lactic acid synthesis from biomass-derived carbohydrates

An experimental study was carried out to convert carbohydrates using bimetal modified beta zeolite to obtain a maximum yield of lactic acid. The relationship between the properties and the catalytic performance of various bimetal modified beta zeolites was evaluated. The results showed that the maximum yield of lactic acid reached 52% with more than 99% glucose conversion over Pb–Sn-beta (0.3 mmol g⁻¹, Pb/Sn = 4 : 7) at 190 °C for 2 h under ambient air pressure. To evaluate the synergetic mechanism of lead and tin, key intermediates such as fructose, dihydroxyacetone, glyceraldehyde and pyruvaldehyde were used as probe reactants that were catalyzed by Pb-beta, Sn-beta and Pb–Sn-beta. The revealed key role of lead was to promote the isomerization of glucose to fructose and the retro-aldol condensation reaction from fructose to dihydroxyacetone and glyceraldehyde; meanwhile, tin had a superior catalytic performance in the dehydration of dihydroxyacetone, the hydration of pyruvaldehyde and the isomerization of pyruvic aldehyde hydrate.

An experimental study was carried out to convert carbohydrates using bimetal modified beta zeolite to obtain a maximum yield of lactic acid.     

Controlling nanodomain morphology of epoxy thermosets templated by poly(caprolactone)-block-poly(dimethylsiloxane)-block-poly(caprolactone) ABA triblock copolymer

In this paper, triblock copolymer was incorporated into epoxy to prepare nano thermosets. After studying the compatibility between polydimethylsiloxane (PDMS), polycaprolactone (PCL) and bisphenol A epoxy resin (E-54), poly(caprolactone)–poly(dimethylsiloxane)–poly(caprolactone) (PCL-b-PDMS-b-PCL) triblock copolymer was incorporated into bisphenol A epoxy resin (E-54) and cured with DDS. A nano structure was formed and the size of the spherical phase became larger with increasing PCL-b-PDMS-b-PCL. According to the fact that TGDDM/PCL was compatible and TGDDM/PDMS was incompatible during the curing reaction, the mechanism of nano structure formation was self-assembly. The factors of influencing nano structure formation were discussed with regard to different curing temperatures and accelerators. Curing kinetics was utilized to study the effect of accelerator on nano structure formation.

FTIR spectrum of PDMS and PCL-b-PDMS-b-PCL triblock copolymer..     

品管圈在促进会阴伤口愈合中的临床应用

【】目的 探讨品管圈(QCC)活动在促进阴道分娩产妇会阴伤口愈合中的临床效果。方法 成立QCC小组,找出影响阴道分娩产妇会阴伤口愈合的相关因素,针对出现的问题进行分析,找出原因,提出整改措施,制定规范的操作流程,再进行PDCA循环,在临床中检测方法的有效性,从而不断提高助产质量,提高产妇的生活质量。结果 观察组产后会阴伤口愈合不良的发生率明显低于对照组,两组比较,差异有统计学意义(X₂=6.3421, p<0.05)。结论 通过QCC,可有效提高阴道分娩产妇伤口愈合率,减轻产妇的痛苦,提高了产妇的生活质量。     

Historically‐informed nursing: A transnational case study in China

The term ‘nurse’ (hushi—’caring scholar’) did not enter the Chinese language until the early 20th century. Modern nursing—a fundamentally Western notion popularized by Nightingale and introduced to China in 1884—profoundly changed the way care of the sick was practiced. For 65 years, until 1949, nursing developed in China as a transnational project, with Western and Chinese influences shaping the profession of nursing in ways that linger today. Co‐authored by Chinese, Canadian, and American nurses, this paper examines the early stages of nursing in one province of China as an exemplar of the transnational nature of nursing development. By identifying sociopolitical influences on the early development of nursing in Shandong, the authors aimed not only to contribute to the nascent body of knowledge on China nursing history, but also to heighten readers’ sensitivity to the existence of historical echoes, residue, and resonances in their own nursing practices. Tracing current issues, values, or practices back to their roots provides context and helps us to better understand the present. Whether we are aware of the details or not, the gestalt of nursing practice in a particular place has been shaped by its history—including in Shandong province in China.