Ligand-Controlled Nickel-Catalyzed Reductive Relay Cross-Coupling of Alkyl Bromides and Aryl Bromides

1,1-Diarylalkanes are important structural frameworks which are widespread in biologically active molecules. Herein, we report a reductive relay cross-coupling of alkyl bromides with aryl bromides by nickel catalysis with a simple nitrogen-containing ligand. This method selectively affords 1,1-diarylalkane derivatives with good to excellent yields and regioselectivity

Impact of Secondary Structure of Polypeptides on Glucose Concentration Sensitivity of Nanocarriers for Insulin Delivery

A reasonably intelligent response to glucose concentration fluctuations is crucial for developing a self-regulated insulin delivery system. Inspired by the relationship between the higher ordered structures of proteins and their versatile functions, the introduction of polypeptides capable of mimicking different secondary structures into the delivery system will be anticipated for adjusting glucose concentration sensitivity. Herein, this work presents the impact of different secondary structural architectures of polypeptide blocks on the stability of glucose-responsive complex nanoparticles (CNPs) in the normal physiological environment and their response to the stimuli of normoglycemic and hyperglycemic conditions in vitro. Results from the conformational investigations of the CNPs carried out using circular dichroism and insulin release under the different stimuli suggested that the stability and glucose sensitivity of the CNPs are closely related to the secondary structure composition of the polypeptide blocks. The CNPs with a dominant α-helix structure exhibit a promising potential to improve normal glycemic control and to reduce the incidences of hyperglycemia and hypoglycemia both in vitro and in vivo

Spatial pattern of soil organic carbon and total nitrogen, and analysis of related factors in an agro-pastoral zone in Northern China

<div><p>The spatial pattern of soil organic carbon (SOC) and total nitrogen (TN) densities plays a profound important role in estimating carbon and nitrogen budgets. Naiman Banner located in northern China was chosen as research site, a total of 332 soil samples were taken in a depth of 100 cm from the low hilly land in the southern part, sandy land in the middle part and an alluvial plain in the northern part of the county. The results showed that SOC and TN density initially decreased and then increased from the north to the south, The highest densities, were generally in the south, with the lowest generally in the middle part. The SOC and TN densities in cropland were significantly greater than those in woodland and grassland in the alluvial plains and for Naiman as a whole. The woodland SOC and TN density were higher than those of grassland in the low hilly land, and higher densities of SOC and TN in grassland than woodland in the sandy land and low hilly land. There were significant differences in SOC and TN densities among the five soil types of Cambisols, Arenosols, Gleysols, Argosols, and Kastanozems. In addition, SOC and TN contents generally decreased with increasing soil depth, but increased below a depth of 40 cm in the Cambisols and became roughly constant at this depth in the Kastanozems. There is considerable potential to sequester carbon and nitrogen in the soil via the conversion of degraded sandy land into woodland and grassland in alluvial plain, and more grassland should be established in sandy land and low hilly land.</p></div

Parameters of the variogram models for the soil organic carbon (SOC) and total nitrogen (TN) densities to a depth of 100 cm in Naiman Banner.

<p>Parameters of the variogram models for the soil organic carbon (SOC) and total nitrogen (TN) densities to a depth of 100 cm in Naiman Banner.</p

Spatial pattern of soil organic carbon and total nitrogen, and analysis of related factors in an agro-pastoral zone in Northern China - Fig 7

<p><b>Vertical distribution of the (a) soil organic carbon (SOC) density and (b) total nitrogen (TN) density to a depth of 100 cm. Data points were plotted at the bottom of each soil layer.</b> Values are means ± SE.</p

Mean values of the soil organic carbon (SOC) and total nitrogen (TN) densities to a depth of 100 cm in the alluvial plains, sandy land, and low hills of Naiman Banner.

<p>Mean values of the soil organic carbon (SOC) and total nitrogen (TN) densities to a depth of 100 cm in the alluvial plains, sandy land, and low hills of Naiman Banner.</p

Differences in the soil organic carbon (SOC) and total nitrogen (TN) densities to a depth of 100 cm for all sites combined in Naiman Banner and for the three land use types.

<p>For a given parameter, bars labeled with different letters differ significantly (P < 0.05, one-way ANOVA followed by LSD test). Values are means ± SE.</p

Differences in the soil organic carbon (SOC) and total nitrogen (TN) densities to a depth of 100 cm among the five soil types.

<p>For a given element, bars labeled with different letters differ significantly (one-way ANOVA followed by LSD test, P < 0.01). Values are means ± SE.</p

Statistical characteristics of the soil organic carbon (SOC) and total nitrogen (TN) densities (kg m^-2 to a depth of 100 cm) in Naiman Banner of northeastern China (n = 332 sample sites).

<p>Statistical characteristics of the soil organic carbon (SOC) and total nitrogen (TN) densities (kg m^-2 to a depth of 100 cm) in Naiman Banner of northeastern China (n = 332 sample sites).</p

Location of the study area and sampling sites.

<p><b>Reprinted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0197451#pone.0197451.ref027" target="_blank">27</a>] under a CC BY license, with permission from [Jie LIAN], original copyright [2017].</b> (a) Naiman Banner is located in the southern part of the Horqin Sandy Land (HSL). The northern and central areas of Naiman Banner belong to the national ecological function protected area (EFPA); the southern part belongs to the Source Region of the West Liaohe River (WLR). (b) The research area is located in the southeastern part of Inner Mongolia, in northern China. The region has been divided into three zones (AP, alluvial plains; SL, sandy land; LH, low hills) based on the soil and land use characteristics and Landsat ETM+ imagery from (c) June 2010 and (d) July 2015.</p