Protein-Based Pickering Emulsion and Oil Gel Prepared by Complexes of Zein Colloidal Particles and Stearate

This paper describes the successful preparation of a protein-based Pickering emulsion, with superior stability against both coalesence and creaming, through a novel strategy of facilitating the formation of protein particles and small molecular weight surfactant complexes; these complexes are able to overcome multiple challenges including limited solubility, poor diffusive mobility, and low interfacial loading. Soluble complexes of water-insoluble corn protein, zein colloidal particles, and surfactant sodium stearate (SS) were fabricated by simple ultrasonication. Gel trapping technology combined with SEM was applied to characterize the adsorbed particles monolayer at the oil–water interface; results revealed an enhanced adsorption and targeted accumulation of zein particles at the interface with the increase of SS concentration. Partial unfolding of zein particles modified by SS above its critical complexation concentration triggered the aggregation and close packing of particles at the oil–water interface and endowed a steric barrier against the coalescence of oil droplets. Moreover, protein-based oil gels without oil leakage were obtained by one-step freeze-drying of the zein-stabilized Pickering emulsions, which could be developed to a viable strategy for structuring liquid oils into semisolid fats without the use of saturated or <i>trans</i> fats

Efficient Synthesis of a Chiral Precursor for Angiotensin-Converting Enzyme (ACE) Inhibitors in High Space-Time Yield by a New Reductase without External Cofactors

A new reductase, CgKR2, with the ability to reduce ethyl 2-oxo-4-phenylbutyrate (OPBE) to ethyl (<i>R</i>)-2-hydroxy-4-phenylbutyrate ((<i>R</i>)-HPBE), an important chiral precursor for angiotensin-converting enzyme (ACE) inhibitors, was discovered. For the first time, (<i>R</i>)-HPBE with >99% <i>ee</i> was produced via bioreduction of OPBE at 1 M without external addition of cofactors. The space-time yield (700 g·L^–1·d^–1) was 27 times higher than the highest record

B7-H1 Expression Is Associated with Poor Prognosis in Colorectal Carcinoma and Regulates the Proliferation and Invasion of HCT116 Colorectal Cancer Cells

<div><p>Background And Objective</p><p>The investigation concerning the B7-H1 expression in colorectal cancer cells is at an early stage. It is unclear whether B7-H1 expression may have diagnostic or prognostic value in colorectal carcinoma. Additionally, how B7-H1 is associated with the clinical features of colorectal carcinoma is not known. In order to investigate the relationship between B7-H1 and colorectal cancer, we analyzed B7-H1 expression and its effect in clinical specimens and HCT116 cells.</p> <p>Methods</p><p>Paraffin-embedded specimens from 143 eligible patients were used to investigate the expression of CD274 by immunohistochemistry. We also examined whether B7-H1 itself may be related to cell proliferation, apoptosis, migration and invasion in colon cancer HCT116 cells.</p> <p>Results</p><p>Our results show that B7-H1 was highly expressed in colorectal carcinoma and was significantly associated with cell differentiation status and TNM (Tumor Node Metastasis) stage. Patients with positive B7-H1 expression showed a trend of shorter survival time. Using multivariate analysis, we demonstrate that positive B7-H1 expression is an independent predictor of colorectal carcinoma prognosis. Our results indicate that B7-H1 silencing with siRNA inhibits cell proliferation, migration and invasion. Furthermore, cell apoptosis was also increased by B7-H1 inhibition.</p> <p>Conclusions</p><p>Positive B7-H1 expression is an independent predictor for colorectal carcinoma prognosis. Moreover, knockdown of B7-H1 can inhibit cell proliferation, migration and invasion.</p> </div

Effect of B7-H1 knockdown on cell proliferation and apoptosis in HCT 116 cells.

<p>(A) MTT analysis to detect cell proliferation. Parental or HCT116 cells were transfected with scrambled siRNA or siRNA targeting B7-H1 for 48 h were seeded in 96-well plates and cell proliferation was detected by MTT. Data were presented as means ± SD, *P<0.05 versus the si-scramble group. (B) Flow cytometric analysis to detect cell apoptosis. Parental or HCT116 cells transfected with scrambled siRNA or siRNA targeting B7-H1 for 48 h were collected and stained with Annexin-V-FITC and PI before flow cytometric analysis. Data were presented as means ± SD, *P<0.05 versus the si-scramble group.</p

Effective knockdown of B7-H1 by siRNA in HCT116 cells.

<p>(A) RT-qPCR analysis to show the B7-H1 mRNA level. Parental or HCT116 cells transfected with scrambled siRNA or siRNA targeting B7-H1 for 48 h were harvested and RT-qPCR was performed; (B) Western blot analysis to detect the B7-H1 protein level. Parental or HCT116 cells transfected with scrambled siRNA or siRNA targeting B7-H1 for 48 h were harvested and cell lysates were prepared and used for Western blot; (C) Flow cytometric analysis and mean channel fluorescence to show the B7-H1 expression on cell membrane. Parental or HCT116 cells transfected with scrambled siRNA or siRNA targeting B7-H1 for 48 h were harvested and cell surface staining was performed before flow cytometric analysis. Data were presented as means ± SD, *P<0.05 versus the si-scramble group.</p

Effect of B7-H1 knockdown on cell migration and invasion in HCT116 cells.

<p>(A) Boyden chamber assay to detect cell migration. Parental or HCT116 cells transfected with scrambled siRNA or siRNA targeting B7-H1 for 48 h were seeded in Boyden chambers without Matrigel-coated membrane, and after another 48 h, migrated cells were stained and counted under a microscope (magnification×10). Representative images were shown. (B) Number of migrated cells shown in A. Data was shown as means ± SD from five fields. *P<0.05 versus the si-scramble group. (C) Boyden chamber assay to detect cell invasion. Parental or HCT116 cells transfected with scrambled siRNA or siRNA targeting B7-H1 for 48 h were seeded in modified Boyden chambers with Matrigel-coated membrane, and after another 24 h, invasive cells that moved through the Matrigel membrane were stained and counted under a microscope (magnification×10). Representative images were shown. (D) Number of invasive cells shown in C. Data was shown as means ± SD from five fields. *P<0.05 versus the si-scramble group.</p

Remodeling of Hyperpolarization-Activated Current, I_h, in Ah-Type Visceral Ganglion Neurons Following Ovariectomy in Adult Rats

<div><p>Hyperpolarization-activated currents (I_h) mediated by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels modulate excitability of myelinated A− and Ah-type visceral ganglion neurons (VGN). Whether alterations in I_h underlie the previously reported reduction of excitability of myelinated Ah-type VGNs following ovariectomy (OVX) has remained unclear. Here we used the intact nodose ganglion preparation in conjunction with electrophysiological approaches to examine the role of I_h remodeling in altering Ah-type neuron excitability following ovariectomy in adult rats. Ah-type neurons were identified based on their afferent conduction velocity. Ah-type neurons in nodose ganglia from non-OVX rats exhibited a voltage ‘sag’ as well as ‘rebound’ action potentials immediately following hyperpolarizing current injections, which both were suppressed by the I_h blocker ZD7288. Repetitive spike activity induced afterhyperpolarizations lasting several hundreds of milliseconds (termed post-excitatory membrane hyperpolarizations, PEMHs), which were significantly reduced by ZD7288, suggesting that they resulted from transient deactivation of I_h during the preceding spike trains. Ovariectomy reduced whole-cell I_h density, caused a hyperpolarizing shift of the voltage-dependence of I_h activation, and slowed I_h activation. OVX-induced I_h remodeling was accompanied by a flattening of the stimulus frequency/response curve and loss of PEMHs. Also, HCN1 mRNA levels were reduced by ∼30% in nodose ganglia from OVX rats compared with their non-OVX counterparts. Acute exposure of nodose ganglia to 17beta-estradiol partly restored I_h density and accelerated I_h activation in Ah-type cells. In conclusion, I_h plays a significant role in modulating the excitability of myelinated Ah-type VGNs in adult female rats.</p></div

I_h in myelinated Ah-type VGNs from adult, non-ovariectomized rats.

<p><b>A</b>) Vagal stimulation-evoked transmembrane action potential in a myelinated Ah-type vagal ganglion neuron (VGN). The value for the conduction velocity (CV) measured between the stimulation and recording site was indicative of an Ah-type cell. <b>B</b>) Transmembrane action potential recorded from the same neuron as in (<b>A</b>) and its first derivative over time (blue trace). Note the presence of a repolarization ‘hump’. <b>C</b>) Examples of membrane potential responses of an Ah-type VGN to a depolarizing and a hyperpolarizing current injection step. The cell was first injected with 150 pA current step, giving rise to repetitive action potential firing, which ceased upon termination of the current injection (blue trace). A −120 pA step current injection caused membrane hyperpolarization (blue trace), which gradually increased to its maximum value (−130 mV, dot in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071184#pone-0071184-g004" target="_blank">Figure 4C</a>) and then depolarized slowly (−96 mV, sag) despite continued current injection. Return of the membrane potential to baseline was associated with the occurrence of a spontaneous action potential. Gray traces show the membrane potential changes in response to a positive and negative current step injection in the presence of the I_h blocker ZD7288 (10 microM/L). ZD7288 suppressed spontaneous action potential discharge during depolarizing current injection, and reduced the sag potential (difference between peak membrane potential and endpulse potential). <b>D</b>) Plots of the peak vs. endpulse voltage as a function of the magnitude of the hyperpolarizing step current injection under control and following application of ZD7288. ZD7288 suppressed sag potentials in Ah-type neurons. Date are mean ±1 SD. <i>n</i> = 6 cells for each data point, *<i>P</i><0.05 and **<i>P</i><0.01 <i>vs</i>. control (Ctrl).</p

Effect of 1.0 microM 17beta-estradiol (17beta-E₂) on I_h in myelinated Ah-type VGNs from ovariectomized (OVX) rats.

<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071184#pone-0071184-t001" target="_blank">Table 1</a> for explanation of V_1/2, S_1/2, and activation time constant (Tau). Data are mean ±1 SD with *<i>P</i><0.05 <i>vs</i> control, <i>n</i> = 5 VGN from 5 ganglion preparations.</p

Single InAs Quantum Dot Grown at the Junction of Branched Gold-Free GaAs Nanowire

We report a new type of single InAs quantum dot (QD) embedded at the junction of gold-free branched GaAs/AlGaAs nanowire (NW) grown on silicon substrate. The photoluminescence intensity of such QD is ∼20 times stronger than that from randomly distributed QD grown on the facet of straight NW. Sharp excitonic emission is observed at 4.2 K with a line width of 101 μeV and a vanishing two-photon emission probability of <i>g</i>²(0) = 0.031(2). This new nanostructure may open new ways for designing novel quantum optoelectronic devices