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It is essential to construct self-supporting electrodes based on earth-abundant iron borides in a mild and economical manner for grid-scale hydrogen production. Herein, a series of highly efficient, flexible, robust, and scalable Fe-B-O@FeB

Bi–B/BiB3O6 materials are modified on various flexible substrates via electroless plating in organic phase for hydrogen production in neutral simulated seawater with outstanding durability and high efficiency, which electrolyzed continuously for more than 36 h at 100 mA cm−2.

Developing economical, efficient and stable bifunctional catalysts for hydrogen production from seawater is of great significance for hydrogen utilization. Herein, sulfur doped iron oxide nanosheet arrays supported on nickel foam (FeOx-Ni3S2@NF) are prepared by a one-pot solvothermal reaction. Owing to the high intrinsic activity of FeOx-Ni3S2, the large catalytic specific surface area of nanosheet arrays and the fast charge transportation capability achieved by the self-supporting configuration, the FeOx-Ni3S2@NF electrode delivers excellent catalytic performance in alkaline simulated seawater (1 M KOH + 0.5 M NaCl). Impressively, a low overpotential of 120 mV at 50 mA cm-2 with a Tafel slope of 57 mV dec-1 for the hydrogen evolution reaction and an overpotential of 470 mV at 200 mA cm-2 with a Tafel slope of 62 mV dec-1 for the oxygen evolution reaction are achieved. More importantly, the voltage is only 1.5 V at 50 mA cm-2 for continuous overall water splitting for 100 h at 200 mA cm-2 with negligible decay in alkaline simulated seawater with almost 100% Faraday efficiency. This work provides a simple and universal strategy to prepare highly efficient bifunctional catalytic materials, promoting the development of Earth-abundant materials to catalyse seawater splitting to produce high-purity hydrogen.

Developing economical, efficient and stable bifunctional catalysts for hydrogen production from seawater is of great significance for hydrogen utilization. Herein, sulfur doped iron oxide nanosheet arrays supported on nickel foam (FeO

Mild construction of highly efficient and durable practical electrodes for overall water splitting (OWS) at industrial-grade current density is currently a significant challenge. Herein, metal-organic framework (MOF) materials are grown in situ on the surface of carbon cloth (CC) at 25 °C, and quickly "interspersed" by cobalt-boron (Co-B) via electroless plating for 30 min to obtain a highly efficient and stable CoB@MOF@CC self-supporting electrode. Owing to the large specific surface area, abundant active sites, and porous structure, the MOF-based CC modified by bamboo leaf-like ultrathin CoB has remarkable electrochemical catalysis efficiency. The CoB@MOF@CC electrode exhibits excellent performance during the hydrogen evolution reaction (η

One formidable challenge to realize high efficiency and long-term stability of seawater electrolysis for hydrogen production is to improve the catalytic activities, corrosion resistance and stability of electrodes. Therefore, a 2D self-supporting bifunctional electrode with excellent stability was designed to efficiently produce hydrogen. Specifically, TiO2 nanorods supported on corrosion-resistant Ti plate (Ti/TiO2) was firstly prepared by one-step alkaline etching and then cellular NiBx catalytic materials were gently modified on Ti/TiO2 by simple electroless plating to obtain Ti/TiO2@NiBx self-supporting electrode. The photoelectrocatalytic performance of the highly-active electrode during Hydrogen evolution reaction (HER), Oxygen evolution reaction (OER) and overall seawater splitting at 10 mA cm−2 were increased by 16.2%, 14.7% and 4.4%, respectively. In the meantime, Ti/TiO2@NiBx continuously electrolyzed over 72 h during HER at the industrial-grade current density (500 mA cm−2) due to the high corrosion resistance of TiO2, the increased specific surface area originated from the modification of amorphous NiBx, which promoted the effective separation of electron-hole pairs in the TiO2 semiconductor structure, and achieved high-efficient seawater electrolysis. Therefore, this work proposed a simple route for preparing catalytic electrodes with high activity and outstanding stability, and also provided theoretical supports for practical application of producing high-purity hydrogen from seawater by highly-efficient photoelectrocatalysis system.

To achieve efficient and stable hydrogen production by water splitting is of great challenges. Herein, a 2D self-supporting catalytic electrode with stability is designed to obtain hydrogen on a large scale from alkaline simulated seawater (1.0 M KOH + 0.5 M NaCl, pH = 14). Specifically, the amorphous NiB active materials are modified on the surface of Ti plate by electroless plating with different time without adding binders and other additives, and Ti@NiB bifunctional catalytic electrode is simply prepared at room temperature. The overpotential of hydrogen evolution reaction at 10 mA·cm−2 is 149 mV in alkaline simulated seawater while that of oxygen evolution reaction is 397 mV at 50 mA·cm−2. The Ti@NiB electrode showing good stability during overall water splitting electrolyzes for over 40 h at 20 mA·cm−2, partly due to the corrosion resistance of Ti plate, the increased specific surface area with the modification of amorphous NiB, and the inseparable attachment between NiB active materials and the robust substrate. This work provides a strategy for preparing electrodes with high activity, low cost and long-term stability application.

Due to the requirement for comprehensive clinical research efforts in China, the importance of biobanking in modern clinical research is outlined in this overview. Hospitals, universities, and research institutes have been well organized as fundamental resources for Chinese biobanking initiatives and the resulting bio-sample collections. Here, a brief history and time line of development of biobanking in China will be introduced, as well as strategic designs for future biobanking development.

Method validation is one of the crucial processes for a professional biobank. However, there are no routine guidelines specially designed for such studies. Therefore, in line with the need for competence in testing and calibration, the International Organization for Standardization (ISO) concept has been introduced to biobanking as a model for Quality Management Systems in this field. Accurate interpretation of the experimental data about the human genome depends on the quality of the genomic DNA. In this study, we focused on the validation of DNA quantitation by spectrophotometry, a basic bio-analytical method in molecular biology. The key factors of precision, accuracy testing, and linearity assessment are presented in assessing the method quality. Internal and external quality controls have been included as required. Our data show that the method of spectrophotometry is qualified for DNA quantitation.

Hypoxia maintained biological characteristics of CD34(+) cells through keeping lower intracellular reactive oxygen specials (ROS) levels. The effects of normoxia and hypoxia on antioxidant enzymes and glutathione redox state were compared in this study. Hypoxia decreased the mRNA expression of both catalase (CAT) and glutathione peroxidase (GPX), but not affected mRNAs expression of superoxide dismutase (SOD). While the cellular GPX activities under hypoxia were apparently less than those under normoxia, neither SOD activities nor CAT activities were affected by hypoxia. The analysis of glutathione redox status and ROS products showed the lower oxidized glutathione (GSSG) levels, the higher reduced glutathione (GSH) levels, the higher GSH/GSSG ratios, and the less O(2)- and H(2)O(2) generation under hypoxia (versus normoxia). Meanwhile more primary CD34(+)CD38(-) cells were obtained when cultivation was performed under hypoxia or with N-acetyl cysteine (the precursor of GSH) under normoxia. These results demonstrated the different responses of anti-oxidative mechanism between normoxia and hypoxia. Additionally, the present study suggested that the GSH-GPX antioxidant system played an important role in HSPCs preservation by reducing peroxidation.

Hypoxia favored the preservation of progenitor characteristics of hematopoietic stem and progenitor cells (HSPCs) in bone marrow. This work aimed at studying the role of reactive oxygen species (ROS)-generating NADPH oxidase system regulated by hypoxia in ex vivo cultures of cord blood CD34+ cells. The results showed that NADPH oxidase activity and ROS generation were reduced in hypoxia with respect to normal oxygen tension. Meanwhile the ROS generation was found to be inhibited by diphenyleneiodonium (the NADPH oxidase inhibitor), or N-acetylcysteine (the ROS scavenger). Accordingly NADPH oxidase mRNA and p67 protein levels decreased in hypoxia. The analysis of progenitor characteristics, including the proportion of cultured cells expressing the HSPCs marker CD34+CD38-, colony production ability of the colony-forming cells (CFCs), and the re-expansion capability of the cultured CD34+ cells, showed that either 5% pO(2) or reduced ROS favored preserving the characteristics of CD34+ progenitors, and promoted the expansion of CD34+CD38- cells as well. The above results demonstrated that hypoxia effectively maintained biological characteristics of CD34+ cells through keeping lower intracellular ROS levels by regulating NADPH oxidase.

Oxygen tension is an important factor that regulates hematopoietic stem cells (HSCs) in both in vivo hematopoietic microenvironment and ex vivo culture system. Although the effect of oxygen tension on ex vivo expansion of HSCs was extensively studied, there were no clear descriptions on physiological function and gene expression analysis of HSCs under different oxygen tensions. In this study, the effects of oxygen tension on ex vivo expansion characteristics of human umbilical cord blood (UCB)-derived CD34(+) cells are evaluated. Moreover, the physiological function of expanded CD34(+) cells was assessed by secondary expansion ability ex vivo and hematopoietic reconstitution ability in vivo. Also, genetic profiling was applied to analyze the expression of genes related to cell function. It was found that low oxygen tension favored expansion of CD34(+) CD38(-) cells. Additionally, CD34(+) cells expanded under low oxygen tension showed better secondary expansion ability and reconstitution ability than those under atmospheric oxygen concentration. Finally, the genetic profiling of CD34(+) CD38(-) cells cultured under low oxygen tension was more akin to freshly isolated cells. These results collectively demonstrate that low oxygen tension was able to better maintain both self-renewal and hematopoietic reconstitution potential and may lay an experimental basis for clinical transplantation of HSCs.

Oxygen tension regulates the biological characteristics of hematopoietic stem and progenitor cells (HSPCs) by modulating intracellular reactive oxygen species (ROS). To better understand oxygen tension mechanism on HSPCs culture, gene expression analysis of human CD34 + CD38 − HSPCs was performed using microarrays. The CD34 + CD38 − HSPCs cultured under normoxia, hypoxia, or with N-acetyl cysteine (NAC, an ROS scavenger) were isolated for transcriptional profilings. Compared to normoxia group, 1 gene was up-regulated and 22 genes were down-regulated in hypoxia group, while 1 gene was up-regulated and 29 genes were down-regulated in NAC group. These differently expressed genes were involved in cell surface markers, blood activation and differentiation. The common down-regulated genes related to dendritic cells (DCs) maturation (CD80, CD86, and JAG1) were confirmed by real-time RT-PCR. Furthermore, the analysis of the phenotypes of DCs, including the DC-characteristic surface molecule CD1a, the costimulatory molecules CD80 and CD86, and HLA-DR, associated with the capacity of DCs to stimulate allogeneic T cells, showed that hypoxia-mediating ROS inhibited the potential of CD34 + CD38 − HSPCs differentiating to mature DCs. All these results demonstrated that hypoxia-reducing ROS down-regulated the genes driving CD34 + CD38 − HSPCs differentiation, which provides an interesting molecular hint to direct their development to DCs during cultures.