The use of a 2-aminopurine-containing split G-quadruplex for sequence-specific DNA detection

A simple, sequence-specific DNA detection method, utilizing a fluorescent 2-aminopurine (2-AP) nucleobase analogue-containing split G-quadruplex as the key detection component, is described. In the sensor, the 2-AP-containing G-quadruplex is split into two segments and linked to a target-specific overhang sequence. The separate G-quadruplex sequences form an active G-quadruplex structure only in the presence of a complementary target DNA, which leads to a significant increase in the intensity of fluorescence from the 2-AP fluorophore. This simple, one-step, homogenous assay was successfully employed to detect target DNA with a high selectivity. In addition, the practical applicability of the detection method was demonstrated by its use in analyzing target DNAs in human serum. To the best of our knowledge, this is the first time that an investigation was carried out in which a fluorescent nucleobase analogue was incorporated into a split G-quadruplex structure and this structure was utilized as the foundation for a specific DNA sensor.

Observation of the Semileptonic Decay D^{0}→a_{0}(980)^{-}e^{+}ν_{e} and Evidence for D^{+}→a_{0}(980)^{0}e^{+}ν_{e}

Using an e^{+}e^{-} collision data sample of 2.93  fb^{-1} collected at a center-of-mass energy of 3.773 GeV by the BESIII detector at BEPCII, we report the observation of D^{0}→a_{0}(980)^{-}e^{+}ν_{e} and evidence for D^{+}→a_{0}(980)^{0}e^{+}ν_{e} with significances of 6.4σ and 2.9σ, respectively. The absolute branching fractions are determined to be B(D^{0}→a_{0}(980)^{-}e^{+}ν_{e})×B(a_{0}(980)^{-}→ηπ^{-})=[1.33_{-0.29}^{+0.33}(stat)±0.09(syst)]×10^{-4} and B(D^{+}→a_{0}(980)^{0}e^{+}ν_{e})×B(a_{0}(980)^{0}→ηπ^{0})=[1.66_{-0.66}^{+0.81}(stat)±0.11(syst)]×10^{-4}. This is the first time the a_{0}(980) meson has been measured in a D^{0} semileptonic decay, which would open one more interesting page in the investigation of the nature of the puzzling a_{0}(980) states.

Measurement of the Absolute Branching Fraction of the Inclusive Decay Λ_{c}^{+}→Λ+X

Based on an e^{+}e^{-} collision data sample corresponding to an integrated luminosity of 567  pb^{-1} taken at the center-of-mass energy of sqrt[s]=4.6  GeV with the BESIII detector, we measure the absolute branching fraction of the inclusive decay Λ_{c}^{+}→Λ+X to be B(Λ_{c}^{+}→Λ+X)=(38.2_{-2.2}^{+2.8}±0.9)% using the double-tag method, where X refers to any possible final state particles. In addition, we search for direct CP violation in the charge asymmetry of this inclusive decay for the first time, and obtain A_{CP}≡[B(Λ_{c}^{+}→Λ+X)-B(Λ[over ¯]_{c}^{-}→Λ[over ¯]+X)]/[B(Λ_{c}^{+}→Λ+X)+B(Λ[over ¯]_{c}^{-}→Λ[over ¯]+X)]=(2.1_{-6.6}^{+7.0}±1.6)%, a statistically limited result with no evidence of CP violation.

Development of novel on-line capillary gas chromatography-based analysis method for volatile organic compounds produced by aerobic fermentation

Many volatile compounds, such as isoprene, a precursor used in the synthesis of natural rubber, have been produced through fermentation using genetically engineered microorganisms. Despite this biotechnological success, measuring the concentrations of volatile compounds during fermentation is difficult because of their high volatility. In current systems, off-line analytical methods usually lead to product loss, whereas on-line methods raise the production cost due to the requirement of complex devices. Here, we developed a novel on-line gas chromatography (GC)-based system for analyzing the concentration of isoprene with the aim to minimize the cost and requirement for devices as compared to current strategies. In this system, a programmable logic controller is used to combine conventional GC with a syringe pump module (SPM) directly connected to the exhaust pipe of the fermentor, and isoprene-containing samples are continuously pumped from the SPM into the GC using an air cylinder recycle stream. We showed that this novel system enables isoprene analysis during fermentation with convenient equipment and without the requirement of an expensive desorption tube. Furthermore, this system may be extended to the detection of other volatile organic compounds in fermentation or chemical processes.

Expression, purification and characterization of halophilic protease Pph_Pro1 cloned from Pseudoalteromonas phenolica

In this study, protease Pph_Pro1 from Pseudoalteromonas phenolica, possessing extracellular proteolytic activity and salt tolerance, was investigated for cloning, expression, and purification purposes. Through optimization, it was determined that optimum soluble recombinant expression was achieved when Pph_Pro1 was co-expressed with the pTf16 vector chaperone in LB medium supplemented with CaCl₂. Pph_Pro1 was purified using osmotic shock and immobilized metal-affinity chromatography (IMAC). Isolated Pph_Pro1 activity was measured as 0.44 U/mg using casein as a substrate. Interestingly, Pph_Pro1 displayed halophilic, alkaliphilic, and unexpected thermostable properties. Furthermore, it was resistant to several hydrophilic and hydrophobic organic solvents. Substrate specificity and kinetic values such as K_m and V_max were determined with casein, bovine serum albumin (BSA), and algal waste protein as substrates, indicating that the Pph_Pro1 protease enzyme had a greater affinity for casein. Based on the remarkable characteristics of this Pph_Pro1 protease enzyme, it can potentially be utilized in many biotechnological industries.

Discovery of glycocholic acid and taurochenodeoxycholic acid as phenotypic biomarkers in cholangiocarcinoma

Although several biomarkers can be used to distinguish cholangiocarcinoma (CCA) from healthy controls, differentiating the disease from benign biliary disease (BBD) or pancreatic cancer (PC) is a challenge. CCA biomarkers are associated with low specificity or have not been validated in relation to the biological effects of CCA. In this study, we quantitatively analyzed 15 biliary bile acids in CCA (n = 30), BBD (n = 57) and PC (n = 17) patients and discovered glycocholic acid (GCA) and taurochenodeoxycholic acid (TCDCA) as specific CCA biomarkers. Firstly, we showed that the average concentration of total biliary bile acids in CCA patients was quantitatively less than in other patient groups. In addition, the average composition ratio of primary bile acids and conjugated bile acids in CCA patients was the highest in all patient groups. The average composition ratio of GCA (35.6%) in CCA patients was significantly higher than in other patient groups. Conversely, the average composition ratio of TCDCA (13.8%) in CCA patients was significantly lower in all patient groups. To verify the biological effects of GCA and TCDCA, we analyzed the gene expression of bile acid receptors associated with the development of CCA in a CCA cell line. The gene expression of transmembrane G protein coupled receptor (TGR5) and sphingosine 1-phosphate receptor 2 (S1PR2) in CCA cells treated with GCA was 8.6-fold and 3.4-fold higher compared with control (untreated with bile acids), respectively. Gene expression of TGR5 and S1PR2 in TCDCA-treated cells was not significantly different from the control. Taken together, our study identified GCA and TCDCA as phenotype-specific biomarkers for CCA.

Observation of a_{0}^{0}(980)-f_{0}(980) Mixing

We report the first observation of a_{0}^{0}(980)-f_{0}(980) mixing in the decays of J/ψ→ϕf_{0}(980)→ϕa_{0}^{0}(980)→ϕηπ^{0} and χ_{c1}→a_{0}^{0}(980)π^{0}→f_{0}(980)π^{0}→π^{+}π^{-}π^{0}, using data samples of 1.31×10^{9}  J/ψ events and 4.48×10^{8}  ψ(3686) events accumulated with the BESIII detector. The signals of f_{0}(980)→a_{0}^{0}(980) and a_{0}^{0}(980)→f_{0}(980) mixing are observed at levels of statistical significance of 7.4σ and 5.5σ, respectively. The corresponding branching fractions and mixing intensities are measured and the constraint regions on the coupling constants, g_{a_{0}K^{+}K^{-}} and g_{f_{0}K^{+}K^{-}}, are estimated. The results improve the understanding of the nature of a_{0}^{0}(980) and f_{0}(980).

Oral administration of Bifidobacterium bifidum TMC3115 to neonatal mice may alleviate IgE-mediated allergic risk in adulthood

This study aimed to demonstrate whether exposure to bifidobacteria during early life influences immunity and alleviates the risk of immunoglobulin E (IgE)-mediated allergies in adulthood. BALB/c neonatal mice (n=54) were administered with a lyophilised cell preparation of Bifidobacterium bifidum TMC3115 (TMC3115) for 3 weeks. Following the intervention, the mice were immunised with intraperitoneal ovalbumin (OVA). The morphology and function of the intestinal epithelium were determined using histopathological examinations. Intestinal microbiota was detected using quantitative PCR and characterised using next-generation sequencing of 16S rRNA genes from faecal DNA. Caecal short-chain fatty acids (SCFAs) were measured using gas chromatography-mass spectrometry. Serum levels of tumour necrosis factor (TNF)-α, interleukin (IL)-6, IL-10, and immunoglobulin E (IgE) and the percentage of splenic CD4+ T cells were examined using enzyme-linked immunosorbent assay and flow cytometry, respectively. TMC3115 did not significantly affect body weight, and cause any severe systemic inflammation or other clinical symptoms among the neonatal or adult mice, although the crypt depths and Muc2-positive cells in some intestinal segments of neonatal mice were significantly lower than control. Oral TMC3115 administration significantly increased faecal microbial diversity, relative abundance of Bacteroidetes and caecal SCFAs production in neonatal mice. Following the intervention, neonatal mice treated with TMC3115 exhibited less increase in serum IgE levels induced by OVA in adults and significantly higher TNF-α and IL-10 levels than in control. Our findings indicate that the oral administration of bifidobacteria, particularly certain strains, such as TMC3115, during early life could alleviate the risk of IgE-mediated allergies in adult host animals. Modifications of intestinal microbiota, SCFAs metabolism and anti-inflammatory cytokine IL-10 production by bifidobacteria may at least in part be a key mechanism underlying the effect of bifidobacteria on the IgE-mediated immune sensitivity of hosts to attacks by allergens at both neonatal and adult stages.

Engineering of artificial microbial consortia of Ralstonia eutropha and Bacillus subtilis for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer production from sugarcane sugar without precursor feeding

Ralstonia eutropha is a well-known microbe reported for polyhydroxyalkonate (PHA) production, and unable to utilize sucrose as carbon source. Two strains, Ralstonia eutropha H16 and Ralstonia eutropha 5119 were co-cultured with sucrose hydrolyzing microbes (Bacillus subtilis and Bacillus amyloliquefaciens) for PHA production. Co-culture of B. subtilis:R. eutropha 5119 (BS:RE5) resulted in best PHA production (45% w/w dcw). Optimization of the PHA production process components through response surface resulted in sucrose: NH₄Cl:B. subtilis: R. eutropha (3.0:0.17:0.10:0.190). Along with the hydrolysis of sucrose, B. subtilis also ferments sugars into organic acid (propionic acid), which acts as a precursor for HV monomer unit. Microbial consortia of BS:RE5 when cultured in optimized media led to the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV) with 66% w/w of dcw having 16 mol% HV fraction. This co-culture strategy overcomes the need for metabolic engineering of R. eutropha for sucrose utilization, and addition of precursor for copolymer production.

Biotechnological potential of microbial consortia and future perspectives

Design of a microbial consortium is a newly emerging field that enables researchers to extend the frontiers of biotechnology from a pure culture to mixed cultures. A microbial consortium enables microbes to use a broad range of carbon sources. It provides microbes with robustness in response to environmental stress factors. Microbes in a consortium can perform complex functions that are impossible for a single organism. With advancement of technology, it is now possible to understand microbial interaction mechanism and construct consortia. Microbial consortia can be classified in terms of their construction, modes of interaction, and functions. Here we discuss different trends in the study of microbial functions and interactions, including single-cell genomics (SCG), microfluidics, fluorescent imaging, and membrane separation. Community profile studies using polymerase chain-reaction denaturing gradient gel electrophoresis (PCR-DGGE), amplified ribosomal DNA restriction analysis (ARDRA), and terminal restriction fragment-length polymorphism (T-RFLP) are also reviewed. We also provide a few examples of their possible applications in areas of biopolymers, bioenergy, biochemicals, and bioremediation.

Precision Measurement of the e^{+}e^{-}→Λ_{c}^{+}Λ[over ¯]_{c}^{-} Cross Section Near Threshold

The cross section of the e^{+}e^{-}→Λ_{c}^{+}Λ[over ¯]_{c}^{-} process is measured with unprecedented precision using data collected with the BESIII detector at sqrt[s]=4574.5, 4580.0, 4590.0 and 4599.5 MeV. The nonzero cross section near the Λ_{c}^{+}Λ[over ¯]_{c}^{-} production threshold is cleared. At center-of-mass energies sqrt[s]=4574.5 and 4599.5 MeV, the higher statistics data enable us to measure the Λ_{c} polar angle distributions. From these, the Λ_{c} electric over magnetic form-factor ratios (|G_{E}/G_{M}|) are measured for the first time. They are found to be 1.14±0.14±0.07 and 1.23±0.05±0.03, respectively, where the first uncertainties are statistical and the second are systematic.

A Hierarchically Modified Graphite Cathode with Au Nanoislands, Cysteamine, and Au Nanocolloids for Increased Electricity-Assisted Production of Isobutanol by Engineered Shewanella oneidensis MR-1

It is necessary to understand the surface structural effects of electrodes on the bioalcohol productivity of Shewanella oneidensis MR-1, but this research area has not been deeply explored. Here, we report that the electricity-assisted isobutanol productivity of Shewanella oneidensis MR-1::pJL23 can be enhanced by sequentially modifying a graphite felt (GF) surface with Au nanoislands (Au), cysteamine (NH₂), and Au nanoparticles (Au NPs). After bacteria were incubated for 50 h with the unmodified GF under various electrode potentials (vs Ag/AgCl), the bacterial isobutanol concentrations increased from 2.9 ± 1 mg/L under no electricity supply to a maximum of 5.9 ± 1 mg/L at -0.6 V. At this optimum electrode potential, the concentrations continued increasing to 9.1 ± 1, 14 ± 2, and 27 ± 2 mg/L when the GF electrodes were modified with Au, NH₂-Au, and Au NP-NH₂-Au, respectively. We further studied how each surface structure affected the bacterial adsorptions, current profiles, and biofilms' electrochemical performances. In particular, these modifications induced the adsorption of elongated bacteria, with the amount dependent on the electrode structure. In the presence of electric supply, the amount of elongated bacteria further increased. We also found that the NH₂-Au-GF and Au NP-NH₂-Au-GF electrodes themselves could increase the concentrations to 11 ± 0.3 and 12 ± 2 mg/L, respectively, upon the bacterial incubation without electricity. Among the electrodes tested, the contribution of electricity to the bacterial isobutanol production was the greatest with the Au NP-NH₂-Au-GF electrode. After 96 h of incubation, the concentration increased to 72 ± 2 mg/L, which was 4.7 and 3.7 times the previously reported values obtained without and with electricity, respectively.

The Urgent Rehabilitation Technique Education Program for Wenchuan Earthquake Victims

An Urgent Rehabilitation Technique Education Program was conducted in response to the needs of the enormous number of the Wenchuan earthquake patients and the shortage of rehabilitation professionals. This program referred to an urgent training program of several rehabilitation techniques that was beneficial to earthquake victims. This short-term program covered the basic clinical technical trainings in physiotherapy, occupational therapy, prosthetics and orthotics, which were included in concentrated technical training, decentralized technical training, and disaster area technical advising. More than 1,500 health-care professionals in Sichuan province took this education program at different locations, which can improve the shortage of rehabilitation professionals, addressing to the clinical need of the earthquake patients, improving local rehabilitation technique, and standardized of the rehabilitation treatments for earthquake patients. This program could be considered as an economical and effective method to help the disaster situation especially there was shortage of health professionals. (Hong Kong j.emerg.med. 2011;18:324-327)

[Study on anemia and vitamin A and vitamin D nutritional status of Chinese urban pregnant women in 2010-2012]

Objective: To evaluate the prevalence of anemia and the nutritional status of vitamins A and D by analyzing hemoglobin, serum retinol, and serum 25-hydroxyvitamin D levels in Chinese urban pregnant women during 2010-2012. Methods: Data were obtained from the China Nutrition and Health Survey in 2010-2012. Using multi-stage stratified sampling and population proportional stratified random sampling, 2 250 pregnant women from 34 metropolis and 41 middle-sized and small cities were included in this study. Information was collected using a questionnaire survey. The blood hemoglobin concentration was determined using the cyanmethemoglobin method, and anemia was determined using the World Health Organization guidelines combined with the elevation correction standard. The serum retinol level was determined using high-performance liquid chromatography, and vitamin A deficiency (VAD) was judged by the related standard recommended by the World Health Organization. The vitamin D level was determined using enzyme-linked immunosorbent assay and vitamin D deficiency was judged by the recommendation standards from the Institute of Medicine of The National Academies. The hemoglobin, serum retinol, and serum 25-hydroxyvitamin D levels were compared, along with differences in the prevalence of anemia, VAD, and the vitamin D deficiency rate (including deficiency and serious deficiency). Results: A total of 1 738 cases of hemoglobin level, 594 cases of serum retinol level, and 1 027 cases of serum 25-hydroxyvitamin D were available for analysis in this study. The overall blood hemoglobin level (P(50) (P(25)-P(75))) was 122.70 (114.00-131.10) g/L; 123.70 (115.21-132.00) g/L for metropolis and 122.01 (113.30-130.40) g/L for middle-sized and small cities. The blood hemoglobin level of metropolis residents was significantly higher than that of middle-sized and small city residents (P=0.027). The overall prevalence of anemia was 17.0% (295/1 738). The overall serum retinol level (P(50) (P(25)-P(75))) was 1.61 (1.20-2.06) μmol/L; 1.50 (1.04-2.06) μmol/L for metropolis and 1.63 (1.31-2.05) μmol/L for middle-sized and small cities. The serum retinol level of metropolis residents was significantly higher than that of middle-sized and small city residents (P=0.033). The overall prevalence of VAD was 7.4% (47/639); 11.5% (33/286) for metropolis and 4.0% (14/353) for middle-sized and small cities. A significant difference was observed in the prevalence of VAD between metropolis and middle-sized and small city residents (P<0.001). The overall serum 25-hydroxyvitamin D level (P(50) (P(25)-P(75))) was 15.41 (11.79-20.23) ng/ml; 14.71 (11.15-19.07) ng/ml for metropolis and 16.02 (12.65-21.36) ng/ml for middle-sized and small cities. A significant difference was observed in the vitamin D level between metropolis and middle-sized and small city residents (P<0.001). The overall prevalence of vitamin D deficiency was 74.3% (763/1 027); A significant difference was observed in the prevalence of serious vitamin D deficiency between metropolis (30.64%(144/470)) and middle-sized and small city residents (26%(267/1 027))(P=0.002). There were no significant differences between blood hemoglobin level and the prevalence of anemia, VAD, and vitamin D deficiency. Conclusion: The prevalence of anemia in Chinese urban pregnant women improved from 2002 to 2012. The prevalence of vitamin D deficiency in pregnant women was generally more serious, while a certain percentage of women had VAD. The prevalence of VAD and serious vitamin D deficiency among pregnant women from metropolis was significantly higher than that of pregnant women from medium and small-sized cities.