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To ascertain the neuroendocrine function of the kisspeptin/ GPR54 system in non-mammalian species, full-length cDNAs encoding for Kiss1 and Kiss2 as well as their putative cognate receptors GPR54a and GPR54b, were isolated from goldfish (Carassius auratus). The deduced protein sequences between Kiss1 and Kiss2 in goldfish share very low similarity, but their putative mature peptides (kisspeptin-10) are relatively conserved. RT-PCR analysis demonstrated that the goldfish kiss1 gene ( gfkiss1) is highly expressed in the optic tectum-thalamus, intestine, kidney, and testis, while the goldfish kiss2 gene ( gfkiss2) is mainly detected in the hypothalamus, telencephalon, optic tectum thalamus, adipose tissue, kidney, heart, and gonads. The two receptor genes ( gfgpr54a and gfgpr54b) are highly expressed in the brain regions including telencephalon, optic tectum thalamus, and hypothalamus. Both mature goldfish kisspeptin-10 peptides (gfKiss1-10 and gfKiss2-10) are biologically active as they could functionally interact with the two goldfish receptors expressed in cultured eukaryotic cells to trigger the downstream signaling pathways with different potencies. The actions of gfKiss1-10 and gfKiss2-10 on LH secretion were further investigated in vitro and in vivo. Intraperitoneal administration of gfKiss1-10 to sexually mature female goldfish could increase the serum LH levels. However, this peptide does not significantly influence LH release from goldfish pituitary cells in primary culture, indicating that the peptide does not exert its actions at the pituitary level. On the other hand, gfKiss2-10 appears to be a much less potent peptide as it exhibits no significant in vivo bioactivity and is also inactive on the primary pituitary cells.

fabrication of perovskite materials provide the feasibility of preparing flexible PSCs (F-PSCs), where their light-weight and bending-flexible properties, make this technology desirable in various occasions such as wearable bioelectronics, portable power equipment, deployable tents, etc. [7] Nowadays, with continuous developments in device structure and materials processing, PCEs of F-PSCs in laboratory have exceeded 21% in small-area (<0.1 cm 2 ) [8,9] and 15% in large-area (100 cm 2 ) [10] solar cell devices, thus showing promises in future flexible PV applications.F-PSCs are fabricated via replacing conventional rigid glass substrates with flexible substrates (e.g., polyethylene terephthalate (PET), and polyethylene naphthalate (PEN)). However, owing to the heat and chemically vulnerable nature of most organic materials, flexible substrate cannot withstand excessively high temperature without losing its elastic properties and therefore presents multiscale challenges that would hinder device performance. First of all, halide perovskites generally have inferior mechanical adhesion with adjacent functional layers or substrates due to their low cohesion energies, [11,12] while the large thermal expansion/contraction of flexible substrates during heat treatment will exacerbate such interfacial adhesion, thus rendering charge transport and mechanical durability in F-PSCs outstanding issues. [13] To achieve low-temperature processable functional layers, SnO 2 has been most frequently used as electron transport layer (ETL) in F-PSCs. [14] However, it presents unsatisfying interfacial electronic compatibility such as surface defects, lattice mismatch and large conduction band offset (ΔE CB ) with perovskite layer. [15,16] In addition, due to the discrepant physical properties (e.g., thermal expansivity) between organiccontaining perovskite and inorganic SnO 2 , perovskite/SnO 2 interface also contributes to phenomenal interfacial residual stress [17,18] and thus the consequent mechanical delamination, [13] once again affecting the PV performance and long-term durability of F-PSCs. To tackle the perovskite/SnO 2 interface problem, previous work included formamidinium iodide (FAI) in SnO 2 layer that consequently formed porous and interpenetrating interface between SnO 2 and perovskite for robust mechanical durability in F-PSCs. [19] While precise control of SnO 2 surface morphology and thickness enabled high-quality perovskite film formation with reduced trap-state density and Halide perovskites have shown superior potentials in flexible photovoltaics due to their soft and high power-to-weight nature. However, interfacial residual stress and lattice mismatch due to the large deformation of flexible substrates have greatly limited the performance of flexible perovskite solar cells (F-PSCs). Here, ammonium formate (HCOONH 4 ) is used as a preburied additive in electron transport layer (ETL) to realize a bottom-up infiltration process for an in situ, integral modification of ETL, perovskite layer, and their interface. The ...

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We report a simple and yet effective method to introduce Mn(2+) ions into semiconducting nanoclusters with atomically precise control. Our method utilizes one type of micrometer-sized crystals, composed of well-defined isolated supertetrahedral chalcogenide nanoclusters (∼2 nm, [Cd6In28S52(SH)4]) whose core metal site is unoccupied in as-synthesized pristine form. This unique model structure with vacant core site makes it possible to achieve ordered distribution of Mn(2+) dopants, and at the same time effectively preclude the formation of Mn(2+) clusters in the host matrix. A two-step synthesis strategy is applied to realize an atomically precise doping of Mn(2+) ion into the core site of the nanoclusters, and to achieve uniform distribution of Mn(2+) dopants in the crystal lattice. The PL, X-ray photoelectron (XPS), as well as the electron paramagnetic resonance (EPR) spectra reveal the successful incorporation of Mn(2+) ion into the core site of the nanocluster. Different from the pristine host material with weak green emission (∼490 nm), the Mn(2+)-doped material shows a strong red emission (630 nm at room temperature and 654 nm at 30 K), which is significantly red-shifted relative to the orange emission (∼585 nm) observed in traditional Mn(2+)-doped II-VI semiconductors. Various experiments including extensive synthetic variations and PL dynamics have been performed to probe the mechanistic aspects of synthesis process and resultant unusual structural and PL properties. The quaternary semiconductor material reported here extends the emission window of Mn(2+)-doped II-VI semiconductor from yellow-orange to red, opening up new opportunities in applications involving photonic devices and bioimaging.

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Summary 6S RNA binds s 70-RNA polymerase and downregulates transcription at many s 70-dependent promoters, but others escape regulation even during stationary phase when the majority of the transcription machinery is bound by the RNA. We report that core promoter elements determine this promoter specificity; a weak -35 element allows a promoter to be 6S RNA sensitive, and an extended -10 element similarly determines 6S RNA inhibition except when a consensus -35 element is present. These two features together predicted that hundreds of mapped Escherichia coli promoters might be subject to 6S RNA dampening in stationary phase. Microarray analysis confirmed 6S RNA-dependent downregulation of expression from 68% of the predicted genes, which corresponds to 49% of the expressed genes containing mapped E. coli promoters and establishes 6S RNA as a global regulator in stationary phase. We also demonstrate a critical role for region 4.2 of s 70 in RNA polymerase interactions with 6S RNA. Region 4.2 binds the -35 element during transcription initiation; therefore we propose one mechanism for 6S RNA regulation of transcription is through competition for binding region 4.2 of s 70.