RELATIONSHIP BETWEEN GROWTH AND MORPHOLOGY OF METARRHIZIUM ANISOPLIAE IN BIOTRANSFORMATION OF STEROID

The fermentation with mold metarrhizium anisopliae has been carried out to determine the relationship between mycelial morphology and growth.Like the biomass concentration,the mycelial morphology seems to be coupled to growth phases:the fractal dimension,a feature calculated from the morphological images,increases during the late lag phase and the early exponential phase,and culminates at a value near 2.4 at half of the exponential phase.This can be attributed to the marked change of rough and smooth pellet proportions during growth and the change can be well expressed by the fractal analysis of mycelial morphology.The mycelial morphology is also strongly related to the biotransformation activity:a mycelial sample was withdrawn from the culture to use for fractal analysis before the steroid substrate (16α,17α epoxy 4 pregnene 3,20 dione) was added;the higher fractal dimension corresponds to the higher conversion rate of steroid biotransformation.And the maximum of fractal dimension appeared prior to the maximum of biomass concentration.It is therefore possible to utilize the fractal dimension curve to supervise the fermentation process more timely and availably than to use the conventional biomass curve to do.

Conversion of Bio-syngas to Liquid Hydrocarbon over CuCoMn-Zeolite Bifunctional Catalysts

A series of bifunctional catalysts composed of a component for higher alcohol synthesis （Cu-CoMn oxides, CCM） and an acidic zeolite （SAPO-34, ZSM-5, Y, MCM-41） were prepared for production of liquid hydrocarbon directly from a bio-syngas through a one-stage pro-cess. The effects of zeolite type, zeolite content, Si/Al ratio and preparation method on catalyst texture and its reaction performance were investigated. Higher selectivities and yields of liquid products were obtained by using bifunctional catalysts. The yields of liquid hydrocarbons decreased in the order CCM-ZSM-5〉CCM-SAPO-34〉CCM-Y〉CCM-MCM-41. CCM-ZSM-5 （20wt%, Si/Al=100） prepared by coprecipitation method displayed the optimal catalytic performance with the highest CO conversion （76%） and yield of liquid products （30%）. The catalysts were characterized by N2 adsorption/desorption, NH3-TPD, XRD, and H2-TPR analysis. The results showed that higher speci c surface areas and pore volumes of bifunctional catalysts were achieved by adding zeolites into CuCoMn precursors. Medium pore dimension and moderate acidity in CCM-ZSM-5 were observed, which proba-bly resulted in its excellent reaction performance. Additionally, a higher number of weaker acid sites （weak and/or medium acid sites） were formed by increasing ZSM-5 content in CCM-ZSM-5 or decreasing Si/Al ratio in ZSM-5. It was also seen that metal dispersion was higher and reducibility of metal ions was easier on the CCM-ZSM-5 catalyst prepared by coprecipitation. The higher alcohols-to-hydrocarbon process provides a promising route to hydrocarbon fuels via higher alcohols from syngas or biobased feedstocks.

Effect of capacitance on ZnO-Bi_2O_3-Yb_2O_3 based varistor for nanosecond transients

The microstructure and electrical properties of ZnO-Bi2O3-Yb2O3 based varistor ceramics were investigated with various temperature effects from 900°C to 1050°C.From the results,it was observed that the increase of sintering temperature offers a reduced capacitive effect from 0.460 nF to 0.321 nF.Furthermore,the grain sizes of varistors were varied from 6.8μm to 9.8μm.The consequence of such smaller grain sizes provided a better voltage gradient of about 895 V/mm for the disc sintered at 900°C and fallen drastically to 410 V/mm for the sample sintered at 1050°C.In addition,there was an increase of non-linearity index to a maximum value of 36.0 and reduced leakage current of 0.026 mA/cm2.However,the density of the varistor decreased with an increase of temperature from 5.41 g/cm3 to 5.24 g/cm3.With this base,the influence of varistor capacitance and high voltage gradient were scrutinized and it led an improved transition speed of the varistor assembly from non-conduction to conduction mode during intruding nanosecond transients.

From Farming to Engineering： The Microbiota and Allergic Diseases

The steady increase of lgE-dependent allergic diseases after the Second World War is a unique phenomenon in the history of humankind. Numerous cross-sectional studies, comprehensive longitudinal cohort studies of children living in various types of environment, and mechanistic experimental studies have pointed to the disappearance of ＂protective factors＂ related to major changes in lifestyle and environment. A common unifying concept is that of the immunoregulatory role of the gut microbiota. This review focuses on the protection against allergic disorders that is provided by the farming environment and by exposure to microbial diversity. It also questions whether and how microbial bioengineering will be able in the future to restore an interplay that was beneficial to the proper immunological development of children in the past and that was irreversibly disrupted by changes in lifestyle. The protective ＂farming environment＂ includes independent and additional influences： contact with animals, stay in barns/stables, and consumption of unprocessed milk and milk products, by mothers during pregnancy and by children in early life. More than the overall quanti- ty of microbes, the biodiversity of the farm microbial environment appears to be crucial for this protection, as does the biodiversity of the gut microbiota that it may provide. Use of conventional probiotics, especially various species or strains of Lactobacillus and Bifidobacterium, has not fulfilled the expectations of allergists and pediatricians to prevent allergy. Among the specific organisms present in cowsheds that could be used for prevention, Acinetobacter （A.） lwoffii F78, Lactococcus （ L.） lactis G121, and Staphylococcus （S.） sciuri W620 seem to be the most promising, based on experimental studies in mouse models of allergic respiratory diseases. However, the development of a new generation of probiotics based on very productive research on the farming environment faces several obstacles that cannot be overcome without a close collaboration between microbiologists, immunologists, and bioengineers, as well as pediatricians, allergists, specialists of clinical trials, and ethical committees.

基于流淌缩皱效应的金属工艺与材料设计应用

本文从金属材料吸热熔化的流动性和放热凝固的缩皱性入手,进行金属液态流淌成型和固态缩皱烧制工艺实验。分析金属固液物态转化过程中受不同因素影响产生流动性、皱缩性、随机性的特殊形态和微观肌理的工艺效果,并从材料的形态美、自然美和意象美等维度将中国传统文人山水画“淡、逸、远”的意境在金属中进行设计实践和应用,达到意与象的交融、情与景的融合、形与神的统一。

Recent advance in porous coordination polymers from the viewpoint of crystalline-state transformation

Recently,research of crystalline-state transformation involving the removal/inclusion of guest molecules in porous coordination polymers(PCPs) was underway.Crystalline-state transformation,especially,single-crystal to single-crystal(SC-SC) transformation as new method for the direct observation of host-guest chemistry,can reveal the intrinsic relevance and interaction between the framework and guest molecules.This review describes our work concerning PCPs and recent investigations of others,within the last four years,from the viewpoint of crystalline-state transformations of PCPs on guest removal or inclusion processes.Ligand substitution reaction and postsynthetic modification of PCPs in SC-SC fashion which were distinguished from conventional crystalline-state transformation triggered by guest removal or exchange were highlighted in this review.The research status of crystalline-state transformation in China was briefly introduced as well.Series of structure analysis techniques including single-crystal X-ray diffraction,powder X-ray diffraction,neutron diffraction,inelastic neutron scattering as well as the application of synchrotron radiation light source will inevitably promote the advance of study of crystalline-state transformation.And as a hotspot,deep investigations of crystalline-state transformation also help us to overcome the challenge of achieving multifunction and the correlation among them,such as sorption,magnetism,optical or electrical properties simultaneously in PCPs and contribute to design stimulate-oriented porous intelligent materials in the future.

SMAD7 and SERPINE1 as novel dynamic network biomarkers detect and regulate the tipping point of TGF-beta induced EMT

Epithelial–mesenchymal transition(EMT) is a complex nonlinear biological process that plays essential roles in fundamental biological processes such as embryogenesis, wounding healing, tissue regeneration,and cancer metastasis. A hallmark of EMT is the switch-like behavior during state transition, which is characteristic of phase transitions. Hence, detecting the tipping point just before mesenchymal state transition is critical for understanding molecular mechanism of EMT. Through dynamic network biomarkers(DNB) model, a DNB group with 37 genes was identified which can provide the early-warning signals of EMT. Particularly, we found that two DNB genes, i.e., SMAD7 and SERPINE1 promoted EMT by switching their regulatory network which was further validated by biological experiments. Survival analyses revealed that SMAD7 and SERPINE1 as DNB genes further acted as prognostic biomarkers for lung adenocarcinoma.

Modeling the rate-dependent ductile-brittle transition in amorphous polymers

The stress response of amorphous polymers in the glass transition region shows apparent temperature and rate dependence.With increasing loading rate,amorphous polymers also exhibit a clear ductile-brittle transition of tensile failure.The rate-dependent behaviors originate from intrinsic relaxations,ranging from perturbation of molecular bonds between polymer segments to reptation of polymer chains.In this work,we develop a constitutive model that incorporates segmental and chain dynamics into the deformation of bond and polymer networks,respectively.The dynamic scission of polymer chains is also incorporated into the theoretical framework to describe the damage evolution and ultimate failure of polymers.A comparison between theoretical predictions and experiments shows that the present model is able to simultaneously capture the observed rate-dependent features,including the transition from glassy state to rubbery state,strain hardening,and failure threshold.