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The stochastic Eigen model proposed by Feng et al. (2007) (Journal of Theoretical Biology, 246, 28) showed that error threshold is no longer a phase transition point but a crossover region whose width depends on the strength of the random fluctuation in an environment. The underlying cause of this phenomenon has not yet been well examined. In this article, we adopt a single peak Gaussian distributed fitness landscape instead of a constant one to investigate and analyze the change of the error threshold and the statistical property of the quasi-species population. We find a roughly linear relation between the width of the error threshold and the fitness fluctuation strength. For a given quasi-species, the fluctuation of the relative concentration has a minimum with a normal distribution of the relative concentration at the maximum of the averaged relative concentration, it has however a largest value with a bimodal distribution of the relative concentration near the error threshold. The above results deepen our understanding of the quasispecies and error threshold and are heuristic for exploring practicable antiviral strategies. [ABSTRACT FROM AUTHOR]

To assess the prophylactic effect of simultaneous placement of mesh and the incidence of parastomal hernia (PSH) after abdominoperineal resection of rectal cancer. This study included real-world data of 56 surgically resected patients with colorectal cancer who were consecutively assigned to two groups: control (no mesh, n = 32) and experimental (received mesh, n = 24). An artificial patch was placed under the tunica vaginalis of rectus abdominis for patients in the experimental group, whereas those in the control group received routine sigmoidostomy. The median follow-up time was >20 mo. The difference in hazards function was analyzed by cox regression analysis. The Kaplan–Meir analysis was used to determine the survival curves. A P value of <0.05 was considered as significant. The postoperative incidence rate of PSH was lower in the experimental (41.7%) group than in the control group (71.9%; P = 0.045). The PSH postoperative time in the experimental group was significantly delayed compared to the control group (48 mo versus 10 mo; P < 0.001). The risk of progression from H1 to H2 was less in the experimental group compared to the control group (49.28% versus 60.86%; P = 0.14). Prophylactic mesh placement significantly prolonged postoperative time for the recurrence of PSH. The incidence of recurrence of H2 (severe PSH) requiring secondary surgical repair was also reduced. [ABSTRACT FROM AUTHOR]

Pancreatic Ductal Adenocarcinoma (PADC) metastasis is the leading cause of morality of this severe malignant tumor. Proteases are key players in the degradation of extracellular matrix which promotes the cascade of tumor metastasis. As a kind of serine proteases, the kallikrein family performs vital function on the cancer proteolysis scene, which have been proved in diverse malignant tumors. However, the specific member of kallikrein family and its function in PDAC remain unexplored. In this study, by data mining of GEO datasets, we have identified KLK10 is upregulated gene in PDAC. We found that KLK10 was significantly overexpressed in tissues of pancreatic intraepithelial neoplasia (PanIN) and PDAC from Pdx1- C re; LSL- K ras G12D/+ mice (KC) and Pdx1- C re; LSL- K ras G12D/+ ; LSL-Tr p 53 R172H/+ mice (KPC) by immunohistochemical analysis. Moreover, KLK10 is extremely elevated in the PDAC tissues, especially that from the PDAC patients with lymphatic and distant metastasis. Aberrant KLK10 expression is significantly correlated with poor prognosis and shorter survival by univariable and multivariable analysis. Functionally, knockdown of KLK10 observably inhibits invasion and metastatic phenotype of PDAC cells in vitro and metastasis in vivo . In addition, blockade of KLK10 attenuates epithelial-mesenchymal transition and activation of FAK-SRC-ERK signaling, which explains the mechanism of KLK10 in promoting metastasis. Collectively, KLK10 should be considered as a promising biomarker for diagnosis and potential target for therapy in PDAC. [ABSTRACT FROM AUTHOR]

Abstract: The site and local structure of activator Eu2+ in phosphor Ca10−x (PO4)6Cl2:xEu2+ is investigated by experiment measurements, first-principle calculations and XAFS simulations. From first-principle calculations, the “local” structure [bond length L(M–O)≤R(M 2+)+R(O2−)] of host shows a significant deformation (expansion) when Ca2+ is substituted by Eu2+, and Eu2+ should prefer 6h site to 4f site in the host. The d→f emission of Eu2+ at 4f site should show a longer wavelength than that of Eu2+ at 6h site. The XAFS measurement and simulations suggest that the Eu2+ in our Ca9.9(PO4)6Cl2:0.1Eu2+ sample mainly locates at 6h site. In the emission spectrum, two emission profiles of Ca9.9(PO4)6Cl2:0.1Eu2+ sample are obtained and assigned. The major one (2.71eV≈456nm) should be the emission of Eu2+ at 6h site. The minor one (2.61eV≈465nm) should be that of Eu2+ at 4f site. [Copyright &y& Elsevier]

Nanosheet BiOI materials were synthesized using the precipitation-hydrothermal method. Subsequently, nanoparticle AgI/BiOI nanosheet composites were fabricated using an ion-exchange method and a controlled amount of BiOI. The phase composition, optical morphology, and absorption properties of the samples were determined using XRD, SEM, XPS, TEM, HRTEM, BET, and UV–Vis diffuse reflectance. Organic dyes, such as methyl orange (MO) and Coomassie brilliant blue R-250 (CBB), were used to check the composites' photocatalytic performance undergoing photodegradation in visible light. The prepared composites had high purity, and the AgI nanoparticles were evenly loaded on the flower-like BiOI nanosheets, both absorbing the visible light. The 50% AgI NP/BiOI NS compound demonstrated the best visible photocatalytic activity and degraded rate of 96.9% and 97% of the MO and CBB dye, respectively, under visible light for 30 ​min. The photocatalytic activity of sole BiOI or AgI was poor, whereas the composites were much better. The composite with 50% AgI exhibited the best photocatalytic activity because of the formation of a heterojunction, which promotes the separation of photogenerated carriers, making AgI stable under visible-light irradiation. AgI nanoparticle/BiOI nanosheet composites were successfully fabricated. The kinetic photocatalytic degradation was controlled by a pseudo-first-order kinetic model. Visible-light-driven photocatalytic performance of composites was enhanced and optimized. The 50% AgI NP/BiOI NS composite showed the highest photocatalytic activity. [Display omitted] • AgI nanoparticle/BiOI nanosheet composites were successfully fabricated via the hydrothermal method of precipitation and the ion-exchange method. • The kinetic photocatalytic degradation was controlled by a pseudo-first-order kinetic model. • Visible-light-driven photocatalytic performance of composites was enhanced and optimized by adjusting the component ratio. • Under Xe lamp irradation as visible light source, the 50% AgI NP/BiOI NS composite showed the highest photocatalytic activity in the degradation of MO and CBB dye in water. [ABSTRACT FROM AUTHOR]