Suppression of Recombination Losses in Polymer:Nonfullerene Acceptor Organic Solar Cells due to Aggregation Dependence of Acceptor Electron Affinity

Here, it is investigated whether an energetic cascade between mixed and pure regions assists in suppressing recombination losses in non‐fullerene acceptor (NFA)‐based organic solar cells. The impact of polymer‐NFA blend composition upon morphology, energetics, charge carrier recombination kinetics, and photocurrent properties are studied. By changing film composition, morphological structures are varied from consisting of highly intermixed polymer‐NFA phases to consisting of both intermixed and pure phase. Cyclic voltammetry is employed to investigate the impact of blend morphology upon NFA lowest unoccupied molecular orbital (LUMO) level energetics. Transient absorption spectroscopy reveals the importance of an energetic cascade between mixed and pure phases in the electron–hole dynamics in order to well separate spatially localized electron–hole pairs. Raman spectroscopy is used to investigate the origin of energetic shift of NFA LUMO levels. It appears that the increase in NFA electron affinity in pure phases relative to mixed phases is correlated with a transition from a relatively planar backbone structure of NFA in pure, aggregated phases, to a more twisted structure in molecularly mixed phases. The studies focus on addressing whether aggregation‐dependent acceptor LUMO level energetics are a general design requirement for both fullerene and NFAs, and quantifying the magnitude, origin, and impact of such energetic shifts upon device performance.     

Gene‐Centric Metagenome Analysis Reveals Gene Clusters for Carbon Monoxide Conversion and Validates Isolation of a Clostridial Acetogen for C2 Chemical Production

Syngas fermentation is largely dependent on acetogens that occur in various anaerobic environmental samples including soil, sediment, and feces. Here the authors report the metagenomic isolation of acetogens for C2 chemical production from syngas. Screening acetogens for C2 chemical production typically involves detecting the presence of the Wood‐Ljungdahl Pathway for carbon monoxide conversion. The authors collect samples from river‐bed sediments potentially having conditions suitable for carbon monoxide‐converting anaerobes, and enrich the samples under carbon monoxide selection pressure. Changes in the microbial community during the experimental procedure are investigated using both amplicon and shotgun metagenome sequencing. Combined next‐generation sequencing techniques enabl in situ tracking of the major acetogenic bacterial group and lead to the discovery of a 16 kb of gene cluster for WLP. The authors isolat an acetogenic clostridial strain from the enrichment culture (strain H21‐9). The functional activity of H21‐9 is confirmed by its high level of production of C2 chemicals from carbon monoxide (77.4 mM acetate and 2.5 mM of ethanol). This approach of incorporating experimental enrichment with metagenomic analysis can facilitate the discovery of novel strains from environmental habitats by tracking target strains during the screening process, combined with validation of their functional activity.     

Newly Identified HNP‐F from Human Neutrophil Peptide‐1 Promotes Hemostasis

Active hemostatic agents can play a crucial role in saving patients’ lives during surgery. Active hemostats have several advantages including utilization of natural blood coagulation and biocompatibility. Among them, although human neutrophil peptide‐1 (HNP‐1) has been previously reported with the hemostatic mechanism, which part of HNP‐1 facilitates the hemostatic activity is not known. Here, a partial peptide (HNP‐F) promoting hemostasis, originating from HNP‐1, has been newly identified by the blood coagulation ability test. HNP‐F shows the best hemostatic effect between the anterior half and posterior half of peptides. Moreover, microscopic images show platelet aggregation and an increase in the concentration of platelet factor 4, and the scanning electron microscope image of platelets support platelet activation by HNP‐F. Thromboelastography indicates decreased clotting time and increased physical properties of blood clotting. Mouse liver experiments demonstrate improved hemostatic effect by treatment of peptide solution. Cell viability and hemolysis assays confirm the HNP‐F's biosafety. It is hypothesized that the surface charge and structure of HNP‐F could be favorable to interact with fibrinogen or thrombospondin‐1. Collectively, because HNP‐F as an active peptide hemostat has many advantages, it could be expected to become a potent hemostatic biomaterial, additive or pharmaceutical candidate for various hemostatic applications.     

Proteomic identification of macrophage migration-inhibitory factor upon exposure to TiO2 particles

Inhalation of particulate matter aggravates respiratory symptoms in patients with chronic airway diseases, but the mechanisms underlying this response remain poorly understood. We used a proteomics approach to examine this phenomenon. Treatment of epithelial cells with BSA-coated titanium dioxide (TiO(2)) particles altered 20 protein spots on the two-dimensional gel, and these were then analyzed by nano-LC-MS/MS. These proteins included defense-related, cell-activating, and cytoskeletal proteins implicated in the response to oxidative stress. The proteins were classified into four groups according to the time course of their expression patterns. For validation, RT-PCR was performed on extracts of in vitro TiO(2)-treated cells, and lung issues from TiO(2)-treated rats were analyzed by immunohistochemical staining and enzyme immunoassay. TiO(2) treatment was found to increase the amount of mRNA for macrophage migration-inhibitory factor (MIF). MIF was expressed primarily in epithelium and was elevated in lung tissues and bronchoalveolar lavage fluids of TiO(2)-treated rats as compared with sham-treated rats. Carbon black and diesel exhaust particles also induced expression of MIF protein in the epithelial cells.     

中印度洋与南海西部表层海水细菌多样性

细菌在海洋生物地球化学循环中发挥着重要作用。为更好地了解海洋细菌的特征及其在海洋环境中的潜在作用, 本文利用纯培养与16S rRNA基因高通量测序技术对中印度洋与南海西部海域表层海水细菌多样性进行研究。纯培养结果表明, 自中印度洋与南海西部表层海水中共分离275株可培养海洋细菌, 隶属于4门49属75种。变形菌门是绝对优势类群(占总株数的68.7%), 其次是放线菌门(21.5%)、拟杆菌门(9.1%)和厚壁菌门(0.7%)。在属水平, 微杆菌属(Microbacterium)与弧菌属(Vibrio)是主要的优势属, 共占总株数的30.0%。在3种分离培养基中, 自1/10 × 2216E培养基中分离细菌的数目与种类最多(89株, 30属); 分离菌株中的细菌菌株有7、9与3个属分别仅在2216E、1/10 × 2216E及葡萄糖甘露糖(glucose-mannose, GM)培养基中生长。此外, 共分离培养出50株细菌(26种)可能代表潜在新分类单元。高通量测序结果显示, 中印度洋和南海西部表层海水中共有23个门531个属。优势门类为变形菌门(72.2%)和拟杆菌门(15.3%), 优势属为嗜冷杆菌属(Psychrobacter, 24.4%)、盐单胞菌属(Halomonas, 16.3%)和亚硫酸杆菌属(Sulfitobacter, 13.9%)。此外, 中印度洋表层海水细菌Shannon-Wiener指数与Pielou均匀度指数显著高于南海西部(P < 0.05), 且细菌群落结构显著不同(P < 0.05)。综合纯培养与原位细菌数据得出, 中印度洋与南海西部海洋细菌具有丰富的多样性, 具有进一步开发研究的价值。     

Human L-type amino acid transporter 1 (LAT1): characterization of function and expression in tumor cell lines

System L is a major nutrient transport system responsible for the transport of large neutral amino acids including several essential amino acids. We previously identified a transporter (L-type amino acid transporter 1: LAT1) subserving system L in C6 rat glioma cells and demonstrated that LAT1 requires 4F2 heavy chain (4F2hc) for its functional expression. Since its oncofetal expression was suggested in the rat liver, it has been proposed that LAT1 plays a critical role in cell growth and proliferation. In the present study, we have examined the function of human LAT1 (hLAT1) and its expression in human tissues and tumor cell lines. When expressed in Xenopus oocytes with human 4F2hc (h4F2hc), hLAT1 transports large neutral amino acids with high affinity (K(m)= approximately 15- approximately 50 microM) and L-glutamine and L-asparagine with low affinity (K(m)= approximately 1.5- approximately 2 mM). hLAT1 also transports D-amino acids such as D-leucine and D-phenylalanine. In addition, we show that hLAT1 accepts an amino acid-related anti-cancer agent melphalan. When loaded intracellularly, L-leucine and L-glutamine but not L-alanine are effluxed by extracellular substrates, confirming that hLAT1 mediates an amino acid exchange. hLAT1 mRNA is highly expressed in the human fetal liver, bone marrow, placenta, testis and brain. We have found that, while all the tumor cell lines examined express hLAT1 messages, the expression of h4F2hc is varied particularly in leukemia cell lines. In Western blot analysis, hLAT1 and h4F2hc have been confirmed to be linked to each other via a disulfide bond in T24 human bladder carcinoma cells. Finally, in in vitro translation, we show that hLAT1 is not a glycosylated protein even though an N-glycosylation site has been predicted in its extracellular loop, consistent with the property of the classical 4F2 light chain. The properties of the hLAT1/h4F2hc complex would support the roles of this transporter in providing cells with essential amino acids for cell growth and cellular responses, and in distributing amino acid-related compounds.     

Reconstruction of soft-tissue defects using serratus anterior adipofascial free flap

The serratus anterior muscle has been suggested as a versatile and reliable flap for reconstruction of head and neck and extremity injuries. The adipofascial layer overlying the serratus anterior muscle is the anatomic layer, which is supplied by the same branch of thoracodorsal artery. Even though great progress has occurred in the prevention of postoperative adhesion of extremity injuries, the problem has not been completely solved and is still of special importance in complex injuries. Between March of 1995 and February of 1996, seven patients underwent reconstructive operation as a result of soft-tissue defects of the upper or lower extremities or the scalp. We transferred free adipofascial tissue overlying the serratus anterior muscle in three patients and both serratus anterior muscle and adipofascial tissue in four patients. A free adipofascial flap overlying serratus anterior muscle was transferred when a gliding surface was required, owing to the exposure of tendons and neurovascular structures. The average duration from operation to follow-up examination was 8 months (from 4 to 16 months). The results of the operations were satisfactory in functional and cosmetic aspects. This kind of flap was very effective in reconstruction of soft-tissue defects and gliding surfaces for these reasons: easy dissection, the capability of obtaining a long vascular pedicle, large-sized flap, composite flap including muscle or rib, and the fact that there was no serious functional or cosmetic deficit at the donor site.     

WNT5A signaling affects pituitary gland shape

Wnt signaling is important in organogenesis, and aberrant signaling in mature cells is associated with tumorigenesis. Several members of the Wnt family of signaling molecules are expressed in the developing pituitary gland. Wnt5a is expressed in the neuroectoderm that induces pituitary gland development and has been proposed to influence pituitary cell specification. We discovered that mice deficient in Wnt5a display abnormal morphology in the dorsal part of the developing pituitary. The expression of downstream effectors of the canonical Wnt pathway is not altered, and expression of genes in other signaling pathways such as Shh, Fgf8, Fgf10 and Fgfr2b is intact. Prop1 and Hesx1 are also important for normal shape of the pituitary primordium, but their expression is unaltered in the Wnt5a mutants. Specification of the hormone-producing cell types of the mature anterior pituitary gland occurs appropriately. This study suggests that the primary role of Wnt5a in the developing pituitary gland is in establishment of the shape of the gland.