3D multi-nozzle system with dual drives highly potential for 3D complex scaffolds with multi-biomaterials

Recently, additive manufacturing is one of the most focused research topics due to its explosive development, especially in manufacturing engineering and medical science. In order to build 3D complex scaffolds with multi-biomaterials for clinical application, a new 3D multi-nozzle system with dual-mode drives, i.e. ejection and extrusion was developed. In this paper, much effort was made to gain fine control of droplet and excellent coordination during fabrication. Specifically, the parameters that influence the size and stability of droplet most was intensively studied. Considering that the biomaterials used in the future may have much difference in properties, the combination of parameters was investigated to facilitate the settings for certainsized droplets, which are potentially eligible for bio-printing. The dispensing nozzles can work well both in independent and convergent mode, which can be freely switched. Outstanding to the most currently used 3D bio-printing techniques, this system can fabricate scaffolds with multi-materials of both low viscosity (by pneumatic dispensing) and high viscosity (through motor extrusion). It is highly expected that this system can satisfy clinical application in the near future

Zambia Signal Functions study 2016 dataset

This dataset contains information related to health facilities’ infrastructure, staffing, equipment, supplies, and capacity to perform various clinical functions related to reproductive and maternal health service provision. The study was conducted in Central Province, Zambia and its primary aim was to assess facilities’ capacity to provide termination of pregnancy services. EMBARGOED UNTIL 31st DEC 201

Benzene risk assessment: does new evidence on myelodysplastic syndrome justify a new approach?

<p>Epidemiologic findings play an important role in benzene risk assessment, which is utilized to guide the selection of recommended benzene exposure levels to prevent adverse health effects. For decades, excess leukemia risk, especially that in the Pliofilm^® cohort, has been the focus of benzene risk assessment. While more stringent benzene standards, often ≤1 ppm, have been promulgated to protect workers from developing leukemia, recent epidemiologic studies have reported elevated risk of myelodysplastic syndrome (MDS). This report aims to examine whether the use of new data on MDS is scientifically warranted in future benzene risk assessments. First, we reviewed current benzene guidelines, regulations, and underlying risk assessments in developed countries. Second, we examined current epidemiologic literature on benzene and MDS, which identified seven studies with simultaneous measures of MDS risk and benzene exposure and 17 studies on MDS in populations potentially exposed to benzene. Next, we examined the potential of the MDS data to serve as the basis of future benzene risk assessments, by comparing its quality and risk estimates with those used in current benzene standards. We conclude from the current literature that there is strong evidence that MDS can be caused by benzene, and the MDS data from the pooled petroleum study should be further examined in future benzene risk assessments. We recommend that future MDS-based benzene risk assessment use total MDS as the endpoint, take into consideration the full exposure period, and examine a range of benzene exposure metrics, including the role of peak, intermittent benzene exposures.</p

sj-docx-1-sci-10.1177_00368504221137466 - Supplemental material for The influence factors of interprovincial power transmission on China's CO₂ emissions

Supplemental material, sj-docx-1-sci-10.1177_00368504221137466 for The influence factors of interprovincial power transmission on China's CO2 emissions by Wenchao Li, Lingyu Xu and Yi Jin in Science Progress</p

Multi-Zinc-Expanded Oligoacenes: An Intriguing Class of Well-Defined Open-Shell Singlet Diradicals

Two classes of multi-Zn-expanded oligoacenes from benzene to pentacene are computationally designed through introducing a Zn array into acene rings in two ways: acene-chain axial versus single-ring quasi-transversal direction. Combined density functional theory, CASSCF, and CCSD calculations predict that all these multi-Zn-expanded oligoacenes have the open-shell singlet diradical ground states, in contrast with the common fact that their parent oligoacenes are closed-shell systems or may have a triplet ground state and only acenes larger than octacene have open-shell singlet diradical ground states. These results offer the first theoretical prediction that the multi-Zn introduction into the acene ring­(s), forming the Zn-expanded oligoacenes, can lead them to diradical structures. The diradical character of the ground states of these molecules arises from the Zn-participation-induced disjoint nature of the nonbonding molecular orbitals that are singly occupied in the diradicals. This work provides a strategy to design perfect and stable singlet diradicals from oligoacenes or their derivatives

Effect of NAA on the growth of <i>A</i>. <i>gallica</i>.

(A) Morphology of A. gallica after 6, 12 and 18 days of growth. A. gallica were cultured on medium with NAA or without NAA (CK). Scale bar = 1 cm. (B) Dry weights of A. gallica in different culture times. The values are the means ± SE of three biological replicates. Asterisks indicate significant differences (* p < 0.05, ANOVA).</p

Expression of glutamine synthetase (GS), glutamate dehydrogenase (GDH) and amino-acid permease inda1 (AAP) genes of <i>A</i>. <i>gallica</i> after NAA treatment at 2, 4, 5, 6 and 8 h.

The y-axis represents the relative gene expression levels analyzed by qRT–PCR. The values are the means ± SE of three biological replicates. Statistically significant differences are indicated by letters above columns (P (DOCX)</p

Transcriptomic changes in <i>A</i>. <i>gallica</i> in response to NAA treatment at 5 and 10 h.

(A) Numbers of DEGs of the treatments; (B) Venn diagram illustrating the number of DEGs among the treatments; (C) Heatmap showing the relative expression levels of DEGs under NAA treatment.</p

Speculative model of NAA promoting amino acid and nitrogen metabolism in <i>A</i>. <i>gallica</i>.

Under NAA treatment, the expression of transcription factor genes was upregulated. Then, transcription factors promote the expression of amino acid and ammonium transporter genes. It promotes the expression of other amino acid and nitrogen metabolism related genes, thereby promoting amino acid and nitrogen metabolism.</p

DEGs associated with amino acid and nitrogen metabolism in <i>A</i>. <i>gallica</i> in response to NAA treatment.

DEGs associated with amino acid and nitrogen metabolism in A. gallica in response to NAA treatment.</p