Enhancement of Propadiene/Propylene Separation Performance of Metal–Organic Frameworks by an Amine-Functionalized Strategy

Here, a hexanuclear Co6(μ3-OH)6 cluster-based metal–organic framework (MOF), [Co6(μ3-OH)6(BTB)2(bpy)3]n (JXNU-15) (bpy = 4,4′-bipyridine), with the 1,3,5-tri(4-carboxyphenyl)benzene (BTB3–) ligand was synthesized for the challenging propadiene/propylene separation. The combination of a large pore volume and a suitable pore environment boosts the significantly high propadiene (C3H4) uptake (311 cm3 g–1 at 298 K and 100 kPa) for JXNU-15. An amine-functionalized MOF of JXNU-15(NH2) was further obtained with the 1,3,5-tri(4-carboxyphenyl)benzene analogue of 3,3″-diamino-5′-(3-amino-4-carboxyphenyl)-[1,1′:3′,1″-terphenyl]-4,4″-dicarboxylic ligand. The comparative studies of propadiene/propylene(C3H4/C3H6) separation performance between isostructural JXNU-15 and JXNU-15(NH2) are provided. JXNU-15(NH2) exhibits an impressive C3H4 capacity at low pressures with 69.1 cm3 g–1 at 10 kPa, which is twice that of JXNU-15 under the same conditions. Moreover, the separation selectivity of JXNU-15(NH2) is 1.3-fold higher as compared to JXNU-15. JXNU-15(NH2) with enhanced C3H4/C3H6 separation performance was elegantly illustrated by gas separation experiments and theoretical simulations. This work presents an amine-functionalized strategy for the enhancement of the C3H4/C3H6 separation performance of MOF

A “Driver Switchover” Mechanism of Influenza Virus Transport from Microfilaments to Microtubules

When infecting host cells, influenza virus must move on microfilaments (MFs) at the cell periphery and then move along microtubules (MTs) through the cytosol to reach the perinuclear region for genome release. But how viruses switch from the actin roadway to the microtubule highway remains obscure. To settle this issue, we systematically dissected the role of related motor proteins in the transport of influenza virus between cytoskeletal filaments <i>in situ</i> and in real-time using quantum dot (QD)-based single-virus tracking (SVT) and multicolor imaging. We found that the switch between MF- and MT-based retrograde motor proteins, myosin VI (myoVI) and dynein, was responsible for the seamless transport of viruses from MFs to MTs during their infection. After virus entry by endocytosis, both the two types of motor proteins are attached to virus-carrying vesicles. MyoVI drives the viruses on MFs with dynein on the virus-carrying vesicle hitchhiking. After role exchanges at actin-microtubule intersections, dynein drives the virus along MTs toward the perinuclear region with myoVI remaining on the vesicle moving together. Such a “driver switchover” mechanism has answered the long-pending question of how viruses switch from MFs to MTs for their infection. It will also facilitate in-depth understanding of endocytosis

Phylogeographic patterns of <i>Lygus pratensis</i> (Hemiptera: Miridae): Evidence for weak genetic structure and recent expansion in northwest China

<div><p><i>Lygus pratensis</i> (L.) is an important cotton pest in China, especially in the northwest region. Nymphs and adults cause serious quality and yield losses. However, the genetic structure and geographic distribution of <i>L</i>. <i>pratensis</i> is not well known. We analyzed genetic diversity, geographical structure, gene flow, and population dynamics of <i>L</i>. <i>pratensis</i> in northwest China using mitochondrial and nuclear sequence datasets to study phylogeographical patterns and demographic history. <i>L</i>. <i>pratensis</i> (n = 286) were collected at sites across an area spanning 2,180,000 km², including the Xinjiang and Gansu-Ningxia regions. Populations in the two regions could be distinguished based on mitochondrial criteria but the overall genetic structure was weak. The nuclear dataset revealed a lack of diagnostic genetic structure across sample areas. Phylogenetic analysis indicated a lack of population level monophyly that may have been caused by incomplete lineage sorting. The Mantel test showed a significant correlation between genetic and geographic distances among the populations based on the mtDNA data. However the nuclear dataset did not show significant correlation. A high level of gene flow among populations was indicated by migration analysis; human activities may have also facilitated insect movement. The availability of irrigation water and ample cotton hosts makes the Xinjiang region well suited for <i>L</i>. <i>pratensis</i> reproduction. Bayesian skyline plot analysis, star-shaped network, and neutrality tests all indicated that <i>L</i>. <i>pratensis</i> has experienced recent population expansion. Climatic changes and extensive areas occupied by host plants have led to population expansion of <i>L</i>. <i>pratensis</i>. In conclusion, the present distribution and phylogeographic pattern of <i>L</i>. <i>pratensis</i> was influenced by climate, human activities, and availability of plant hosts.</p></div

Identification and validation of reference genes for gene expression analysis in <i>Aphidius gifuensis</i> (Hymenoptera: Aphidiidae)

<div><p>Reference genes have been utilized in estimating gene expression levels using quantitative reverse transcriptase-quantitative polymerase chain reaction (qRT-PCR) analysis. <i>Aphidius gifuensis</i> Ashmaed is one of the most widely used biological control agents for aphids. The biological properties of this species have been studied in detail, and current investigations are focused on elucidating the regulatory mechanisms in its host However, the appropriate reference genes for target gene expression studies have not been identified. In this study, the expression profiles of 12 candidate reference genes were evaluated under different experimental conditions(development stage, sex, tissue type, diet) by using dedicated algorithms, including geNorm, Normfinder, BestKeeper, and ΔCt. In addition, RefFinder was used to rank the overall stability of the candidate genes. Finally, we recommend three optimal reference genes for the normalization of qRT-PCR data in the presence of specific variables, which include <i>ACTB</i>, <i>RPL13</i>, and <i>PPI</i> for different developmental stages; <i>RPS18</i>, <i>ACTB</i>, and <i>RPL13</i> for sexes; <i>RPL13</i>, <i>PRII3</i>, and <i>RPS18</i> in different tissue types; and <i>RPL13</i>, <i>RPL27</i>, and <i>ACTB</i> in diverse diets. The present study has identified optimal reference genes that could be used in estimating the expression levels of specific genes under these conditions following the Minimum Information for publication of Quantitative real-time PCR Experiments (MIQE) guidelines, which would facilitate in advancements in functional genomics research on <i>A</i>. <i>gifuensis</i>.</p></div

Primers used for studying reference gene expression in <i>A</i>. <i>gifuensis</i> by qRT-PCR.

<p>Primers used for studying reference gene expression in <i>A</i>. <i>gifuensis</i> by qRT-PCR.</p

Expression stability and relative ranking of the 12 reference genes as predicted by using geNorm.

<p>The mean expression stability (M) was calculated by stepwise exclusion of the least stable gene across all the samples within a particular group set. The mean stability of different genes is plotted; the least stable genes are represented on the left and the most stable on the right side of the plot.</p