Engineering of a genome-reduced host: practical application of synthetic biology in the overproduction of desired secondary metabolites.

Synthetic biology aims to design and build new biological systems with desirable properties, providing the foundation for the biosynthesis of secondary metabolites. The most prominent representation of synthetic biology has been used in microbial engineering by recombinant DNA technology. However, there are advantages of using a deleted host, and therefore an increasing number of biotechnology studies follow similar strategies to dissect cellular networks and construct genome-reduced microbes.

Electrochemically deposited nanocomposite of chitosan and carbon nanotubes for detection of human chorionic gonadotrophin.

A new label-free amperometric immunosensor was developed for detection of human chorionic gonadotrophin (hCG) based on multiwall carbon nanotubes-chitosan (MWNTs-CS) complex film and three-dimensional AuNPs-TiO(2) hybrid. Firstly, MWNTs-CS film was deposited on a glassy carbon electrode (GCE) by a simple and controllable electrodeposition method. Next, thionine (Thi), as a redox probe, was covalently bound onto the MWNTs-CS film with glutaraldehyde (GA) to obtain the Thi/MWNTs-CS film.

Ultrasensitive electrochemical strategy for NT-proBNP detection with gold nanochains and horseradish peroxidase complex amplification.

A novel electrochemical immunosensor for sensitive detection of cardiac biomarker N-terminal pro-B-type natriuretic peptide (NT-proBNP) is fabricated based on the nanostructural gold and carbon nanotubes composite as desirable platform for the capture antibodies immobilization and gold nanochains (AuNCs) and horseradish peroxidase (HRP) complex labeled secondary antibodies (AuNCs-HRP-Ab(2)) for signal amplification. The gold nanochains were prepared by the employment of L-ascorbic acid (AA) as a mediator and template. With the surface area enhancement by nanostructural gold functionalized carbon nanotubes composite, the amount of immobilized primary antibodies (Ab(1)) can be enhanced.

Horseradish peroxidase-functionalized Pt hollow nanospheres and multiple redox probes as trace labels for a sensitive simultaneous multianalyte electrochemical immunoassay.

A novel strategy for a simultaneous multianalyte electrochemical immunoassay is proposed using thionine-labeled anti-AFP and ferrocene-labeled anti-CEA as tracers; each biorecognition event yielded a distinct voltammetric peak, whose position and size reflected the identify and level of the corresponding antigen.

A signal-on electrochemical probe-label-free aptasensor using gold-platinum alloy and stearic acid as enhancers.

In the present study, a new electrochemical probe-label-free aptasensor for thrombin (TB) based on the amplification of gold-platinum alloy nanoparticles (Au-PtNPs) and stearic acid was reported. Nafion@multiwalled carbon nanotubes (MWCNTs) coated electrode was firstly modified with electrochemical probe of methylene blue (MB). Then, Au-PtNPs were electrodeposited onto the electrode surface for the immobilization of aptamer and further hybridization of stearic acid labeled thrombin aptamer (TBA).

[Establishment and its biological characteristics of patient-derived lung cancer xenograft models].

Background And Objective: With the ongoing need to improve therapy for lung cancer, there has been an increasing interest in the development of reliable preclinical models to test novel therapeutics. The aim of this study is to establish a patient-derived lung cancer xenograft model in mice and to observe the biological characteristics of xenografts.

Methods: Surgically resected tumor specimens from patients with lung cancer were implanted in the subcutaneous layer of the NOD/ SCID mice.

Thy-1 attenuates TNF-alpha-activated gene expression in mouse embryonic fibroblasts via Src family kinase.

Heterogeneous surface expression of Thy-1 in fibroblasts modulates inflammation and may thereby modulate injury and repair. As a paradigm, patients with idiopathic pulmonary fibrosis, a disease with pathologic features of chronic inflammation, demonstrate an absence of Thy-1 immunoreactivity within areas of fibrotic activity (fibroblast foci) in contrast to the predominant Thy-1 expressing fibroblasts in the normal lung. Likewise, Thy-1 deficient mice display more severe lung fibrosis in response to an inflammatory injury than wildtype littermates.

Reverse biological engineering of hrdB to enhance the production of avermectins in an industrial strain of Streptomyces avermitilis.

Avermectin and its analogues are produced by the actinomycete Streptomyces avermitilis and are widely used in the field of animal health, agriculture, and human health. Here we have adopted a practical approach to successfully improve avermectin production in an industrial overproducer. Transcriptional levels of the wild-type strain and industrial overproducer in production cultures were monitored using microarray analysis.

Enzyme biosensor based on the immobilization of HRP on SiO₂/BSA/Au composite nanoparticles.

In this work, an enzyme biosensor based on the immobilization of horseradish peroxidase (HRP) on SiO₂/BSA/Au/thionine/nafion-modified gold electrode was fabricated successfully. Firstly, nafion was dropped on the surface of the gold electrode to form a nafion film followed by chemisorption of thionine (Thi) as an electron mediator via the ion-exchange interaction between the Thi and nafion. Subsequently, the SiO₂/BSA/Au composite nanoparticles were assembled onto Thi film through the covalent bounding with the amino groups of Thi.

Functionalized SiO2 labeled CA19-9 antibodies: a new strategy for signal amplification of antigen-antibody sensing processes.

A new strategy was described for amplifying the response of the antigen-antibody sensing processes by functionalizing SiO(2) nanoparticles labeled secondary antibodies based on a sandwich immunoassay in this work. At first, the multi-walled carbon nanotubes (CNTs) were individually dispersed in the aqueous bovine serum albumin (BSA) to obtain BSA molecules coated CNTs (BSA-CNTs). Then the gold colloids (nano-Au) were absorbed on the BSA-CNTs surface by the amido and disulfide groups of BSA.

An electrochemical enzyme bioaffinity electrode based on biotin-streptavidin conjunction and bienzyme substrate recycling for amplification.

A signal amplificatory electrochemical immunoassay with biotin-streptavidin conjunction and multienzymatic-based substrate recycling was developed in this work. Biotinylated secondary antibody (bio-IgG) was preliminarily assembled onto the immunosensor interface based on the sandwich format. Streptavidin was then loaded based on biotin-streptavidin conjunction.

A novel label-free electrochemical aptasensor for thrombin based on the {nano-Au/thionine}n multilayer films as redox probes.

Herein, a novel label-free electrochemical aptasensor based on direct immobilization of the redox probes on an electrode surface was reported. Gold electrode coated Nafion was firstly modified with redox probe-thionine (Thi) through ion exchange adsorption. Then, with the help of chemisorption and electrostatic adsorption, negatively charged nano-Au and positively charged Thi were layer-by-layer (LBL) self-assembled onto the modified electrode surface, which formed {nano-Au/Thi(+)}(n) multilayer films for improving the amount of redox probes and immobilizing thiolated thrombin aptamers (TBA).

Assessing the potential of an induced-mutation strategy for avermectin overproducers.

Mutant libraries of avermectin-producing Streptomyces avermitilis strains were constructed by different mutagenesis strategies. A metric was applied to assess the mutation spectrum by calculating the distribution of average phenotypic distance of each population. The results showed for the first time that a microgravity environment could introduce larger phenotype distribution and diversity than UV and N-methyl-N-nitro-N-nitrosoguanidine (NTG) could.

Rational design for over-production of desirable microbial metabolites by precision engineering.

Microbes represent a valuable source of commercially significant natural products that have improved our quality of life. Precision engineering can be used to precisely identify and specifically modify genes responsible for production of natural products and improve this production or modify the genes creating products that would not otherwise be produced. There have been several success stories concerning the manipulation of regulatory genes, pathways, and genomes to increase the productivity of industrial microbes.

Study on an amperometric immunosensor based on Nafion-cysteine composite membrane for detection of carcinoembryonic antigen.

In this work, protonated L-cysteine was entrapped in Nafion (Nf) membrane by cation exchange function, forming Nf-Cys (cysteine) composite membrane, which was more stable, compact, biocompatible, and favorable for mass and electron transfer compared with Nf film solely. Then gold (Au) nanoparticles were adsorbed onto the electrode surface by thiol groups on the composite membrane. After that, nano-Au monolayer was formed, onto which carcinoembryonic antibody was loaded to prepare carcinoembryonic antigen (CEA) immunosensor.

Complementary acupuncture in Parkinson's disease: a spect study.

We studied cerebral effects of complementary acupuncture in Parkinson's disease using single photon emission computed tomography (SPECT) measures of 99mTc-ECD and 99mTc-TRODAT-4, before and after five weeks of treatment. Ten patients were randomly assigned to receive levodopa alone (controls) or levodopa and complementary scalp electro-acupuncture. Before treatment, no hemispheric regional cerebral blood flow (rCBF) differences were found, whereas striatal dopamine transporter (DAT) activity was lower in the most affected hemisphere.

Energy efficiency of pre-treating excess sewage sludge with microwave irradiation.

The objective of this study is to investigate the energy consumption of pre-treating excess sewage sludge with microwave irradiation using several parameters, including temperature rise, degree of cell destruction, SCOD/TCOD ratio (solids solubilization), and biogas production to evaluate the energy efficiency. It was found that water content was the most important factor that influenced the energy efficiency of raising the temperature and promoting the solubilization of solid materials. Increasing specific energy (E(s)) accelerated the biogas production, but there was a limit to this process.

Multi-walled carbon nanotubes and Ru(bpy)3(2+)/nano-Au nano-sphere as efficient matrixes for a novel solid-state electrochemiluminescence sensor.

An effective method for immobilization of Ru(bpy)(3)(2+) on glassy carbon electrode surface (GCE) is developed for the preparation of a novel electrochemiluminescence sensor. First of all, the positively charged Ru(bpy)(3)(2+) is modified on the surface of negatively charged gold nanoparticles (nano-Au) via the electrostatic interactions to obtain the Ru(bpy)(3)(2+)/nano-Au nano-sphere (abbreviate as Ru-AuNPs). Subsequently, the large amount of Ru-AuNPs are immobilized on the multi-wall carbon nanotubes (MWCNTs)-Nafion homogeneous composite coated GCE by dual interaction: firstly, the Nafion, a kind of typical cation-exchange membrane, can absorb the Ru-AuNPs as the enrichment of cation Ru(bpy)(3)(2+) on the Ru-AuNPs surface; secondly, the employment of carboxylic MWCNTs in the Nafion film can also chemosorb the Ru(bpy)(3)(2+) cation on the Ru-AuNPs surface to increase the carrier content.

Ru(bpy)3(2+)-doped silica nanoparticles labeling for a sandwich-type electrochemiluminescence immunosensor.

A new approach was established to construct a sandwich-type electrochemiluminescence (ECL) immunosensor by using Ru(bpy)(3)(2+)-doped silica (abbreviated as Ru-SiO(2)) nanoparticles to label secondary antibody. Firstly, carboxylate-terminated multi-walled carbon nanotubes (MWCNTs) were modified on the electrode to bond with avidin. Subsequently, biotinylated antibodies were immobilized on the surface of the electrode by employing the specific interaction of biotin/avidin and the non-covalent and covalent conjugation function of MWCNTs.

Identification of avermectin-high-producing strains by high-throughput screening methods.

Avermectins produced by Streptomyces avermitilis are potent against a broad spectrum of nematode and arthropod parasites with low-level side effects on the host organisms. This study was designed to investigate a high-throughput screening strategy for the efficient identification of avermectin high-yield strains. The production protocol was miniaturized in 96 deep-well microplates.

Complementary acupuncture treatment increases cerebral metabolism in patients with Parkinson's disease.

We used positron emission tomography (PET) and the 18-flourodeoxyglucose tracer to study cerebral effects of complementary acupuncture in Parkinson's disease. Five patients received scalp-acupuncture and Madopa, while the other five had Madopa only. PET scans before and after 5 weeks of complementary acupuncture treatment show increased glucose metabolisms in parietal, temporal, occipital lobes, the thalamus, and the cerebellum in the light-diseased hemisphere, and in parietal and occipital lobes of the severe-diseased hemisphere.

Medium optimization for the production of avermectin B1a by Streptomyces avermitilis 14-12A using response surface methodology.

Response surface methodology was employed to optimize the composition of medium for the production of avermectin B1a by Streptomyces avermitilis 14-12A in shaker flask cultivation. Corn starch and yeast extract were found to have significant effects on avermectin B1a production by the Plackett-Burman design. The steepest ascent method was used to access the optimal region of the medium composition, followed by an application of response surface.

Porous redox-active Cu2O-SiO2 nanostructured film: preparation, characterization and application for a label-free amperometric ferritin immunosensor.

A novel Cu(2)O-SiO(2) nanostructured particle was synthesized by a solution-phase method and was adopted for construction of a label-free amperometric immunosensor. The porous Cu(2)O-SiO(2) nanoparticles had good redox electrochemical activity, large surface-to-volume ratio, film-forming ability and high stability. The physical morphology and structure of Cu(2)O-SiO(2) nanoparticles were examined by scanning electron microscope (SEM) and transmission electron microscopy (TEM).

Ferrocenyl-doped silica nanoparticles as an immobilized affinity support for electrochemical immunoassay of cancer antigen 15-3.

The aim of this study is to elaborate a simple and sensitive electrochemical immunoassay using ferrocenecarboxylic (Fc-COOH)-doped silica nanoparticles (SNPs) as an immobilized affinity support for cancer antigen 15-3 (CA 15-3) detection. The Fc-COOH-doped SNPs with redox-active were prepared by using a water-in-oil microemulsion method. The use of colloidal silica could prevent the leakage of Fc-COOH and were easily modified with trialkoxysilane reagents for covalent conjugation of CA 15-3 antibodies (anti-CA 15-3).

Bienzyme functionalized three-layer composite magnetic nanoparticles for electrochemical immunosensors.

The preparation, characterization and application of a three-layer magnetic nanoparticle composed of an Fe(3)O(4) magnetic core, a Prussian Blue (PB) interlayer and a gold shell (it can be abbreviated as Au-PB-Fe(3)O(4)) for an ultrasensitive and reproducible electrochemical immunosensing fabrication were described for the first time in this work. With the employment of the Au-PB-Fe(3)O(4) nanoparticle, a new signal amplification strategy was developed based on bienzyme (horseradish peroxidase and glucose oxidase) functionalized Au-PB-Fe(3)O(4) nanoparticles for an electrochemical immunosensing fabrication by using Carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) as model systems, respectively. The experiment results show that the multilabeled Au-PB-Fe(3)O(4) nanoparticles exhibit satisfying redox electrochemical activity and high enzyme catalysis activity, which predetermine their utility in high sensitivity antibody detection schemes.