Although halophilic archaea are rich in natural environments, their biotechnological applications are not as prevalent as those of other extremophiles, such as thermophiles and alkaliphiles. This study presents an simple method to prepare a hydrogel composite using crude cell lysate of a halophilic archaea, Halorubrum ejinoor sp. (H.e.) which was isolated from a saline lake in Inner Mongolia, China. Furthermore, formation mechanism and potential applications of the hydrogel as an adsorbing material are discussed.
ResultsHalorubrum ejinoor sp. (H.e.) cell lysate was firstly prepared by adding pure water onto the H.e. cell pellet, followed by a short incubation at 60 °C. The cell lysate was injected into different metal ion (or H+) solutions to obtain the hydrogel composite. It was observed that H+, Fe3+, La3+, Cu2+, and Ca2+ induced gelation of the cell lysate, while Fe2+, Co2+, Ni2+, Mg2+, Na+, and K+ did not. DNA and extracellular polysaccharides (EPS) in the H.e. cell lysate were found to be responsible for the gelation reaction. These results suggest that DNA and EPS should be crosslinked by metal ions (or H+) and form a networked structure in which the metal ion (or H+) serves as an anchor point. Potential application of the hydrogel as an adsorbing material was explored using La3+-induced H.e. hydrogel composite. The hydrogel composite can adsorb the fluoride, phosphate and DNA-binding carcinogenic agents, such as acridine orange.
ConclusionsThe simplicity and cost effectiveness of the preparation method might make H.e. hydrogel a promising adsorbing material. This work is expected to expand the technical applications of haloarchaea.
相似文献Balloon pulmonary angioplasty (BPA) is an emerging treatment in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic disease (CTED). We describe the first safety and efficacy results of BPA in the Netherlands.
MethodsWe selected all consecutive patients with inoperable CTEPH and CTED accepted for BPA treatment who had a six-month follow-up in the St. Antonius Hospital in Nieuwegein and the Amsterdam University Medical Center (UMC) in Amsterdam. Functional class (FC), N?terminal pro-brain natriuretic peptide (NT-proBNP), 6?minute walking test distance (6MWD) and right-sided heart catheterisation were performed at baseline and six months after last BPA. Complications for each BPA procedure were noted.
ResultsA hundred and seventy-two BPA procedures were performed in 38 patients (61% female, mean age 65?±?15 years). Significant improvements six months after BPA treatment were observed for functional class (63% FC I/II to 90% FC I/II, p?=?0.014), mean pulmonary artery pressure (?8.9?mm?Hg, p?=?0.0001), pulmonary vascular resistance (?2.8 Woods Units (WU), p?=?0.0001), right atrial pressure (?2.0?mm?Hg, p?=?0.006), stroke volume index (+5.7?ml/m2, p?=?0.009) and 6MWD (+48m, p?=?0.007). Non-severe complications occurred in 20 (12%) procedures.
ConclusionsBPA performed in a CTEPH expert centre is an effective and safe treatment in patients with inoperable CTEPH.
相似文献New treatments for bone diseases require testing in animal models before clinical translation, and the mouse tibia is among the most common models. In vivo micro-Computed Tomography (microCT)-based micro-Finite Element (microFE) models can be used for predicting the bone strength non-invasively, after proper validation against experimental data. Different modelling techniques can be used to estimate the bone properties, and the accuracy associated with each is unclear. The aim of this study was to evaluate the ability of different microCT-based microFE models to predict the mechanical properties of the mouse tibia under compressive load. Twenty tibiae were microCT scanned at 10.4 µm voxel size and subsequently compressed at 0.03 mm/s until failure. Stiffness and failure load were measured from the load–displacement curves. Different microFE models were generated from each microCT image, with hexahedral or tetrahedral mesh, and homogeneous or heterogeneous material properties. Prediction accuracy was comparable among models. The best correlations between experimental and predicted mechanical properties, as well as lower errors, were obtained for hexahedral models with homogeneous material properties. Experimental stiffness and predicted stiffness were reasonably well correlated (R2 = 0.53–0.65, average error of 13–17%). A lower correlation was found for failure load (R2 = 0.21–0.48, average error of 9–15%). Experimental and predicted mechanical properties normalized by the total bone mass were strongly correlated (R2 = 0.75–0.80 for stiffness, R2 = 0.55–0.81 for failure load). In conclusion, hexahedral models with homogeneous material properties based on in vivo microCT images were shown to best predict the mechanical properties of the mouse tibia.
相似文献A novel electro-optical technique for deformability measurement is described. This method is faster and more convenient than “standard” procedures. Erythrocytes (RBC, 106 cells/mL suspended in isotonic sucrose 10%, ionic strength 10? M/L, pH 6.5) are ordered in an electric field (E = 104 Vp-p/m,v = 103 Hz) following the field direction, as a result of an induced electric dipole moment. After the switching off of the electric field, a certain time is required for the electro-optic effect to subside. Under the action of thermal motion, the suspended erythrocytes virtually return to their initial unordered state. The decay time (return time) is the investigated parameter. Results show that if erythrocyte deformability is reduced, the return time is longer than in control RBC. Suspensions of erythrocytes with reduced deformability, achieved by treatment with glutaraldehyde at concentrations ranging from 10?8 to 10?1 M/L, are measured. The suggested electro-optic method has good precision and requires a very small quantity of blood (about 0.1 mL), which makes it potentially useful in clinical practice.
相似文献Partial Least Squares-Discriminant Analysis (PLS-DA) is a PLS regression method with a special binary ‘dummy’ y-variable and it is commonly used for classification purposes and biomarker selection in metabolomics studies. Several statistical approaches are currently in use to validate outcomes of PLS-DA analyses e.g. double cross validation procedures or permutation testing. However, there is a great inconsistency in the optimization and the assessment of performance of PLS-DA models due to many different diagnostic statistics currently employed in metabolomics data analyses. In this paper, properties of four diagnostic statistics of PLS-DA, namely the number of misclassifications (NMC), the Area Under the Receiver Operating Characteristic (AUROC), Q 2 and Discriminant Q 2 (DQ 2) are discussed. All four diagnostic statistics are used in the optimization and the performance assessment of PLS-DA models of three different-size metabolomics data sets obtained with two different types of analytical platforms and with different levels of known differences between two groups: control and case groups. Statistical significance of obtained PLS-DA models was evaluated with permutation testing. PLS-DA models obtained with NMC and AUROC are more powerful in detecting very small differences between groups than models obtained with Q 2 and Discriminant Q 2 (DQ 2). Reproducibility of obtained PLS-DA models outcomes, models complexity and permutation test distributions are also investigated to explain this phenomenon. DQ 2 and Q 2 (in contrary to NMC and AUROC) prefer PLS-DA models with lower complexity and require higher number of permutation tests and submodels to accurately estimate statistical significance of the model performance. NMC and AUROC seem more efficient and more reliable diagnostic statistics and should be recommended in two group discrimination metabolomic studies.
相似文献The main purpose of this paper is to explore the opportunities for fresh Nostoc sphaeroides (N. sphaeroides) to be applied to 3D food printing. N. sphaeroides is rich in nutrients and its paste possesses shear thinning properties. It was found the product obtained by 3D food printing with fresh N. sphaeroides had poor printability and was easy to collapse. In this study, we compared the addition of different potato starch (2%, 4%, 6% and 8%) to the characteristics of 3D printing of the N. sphaeroides gel system. The results obtained from the rheological analysis showed that the 6% potato starch added to of N. sphaeroides gel can be utilized for 3D food printing. The addition of potato starch increased the viscosity of the mixture so the printed lines were not easily broken, and the “self-supporting ability” of the material itself was enhanced to maintain a good shape without collapse. Texture profile analysis also showed that the 6% starch added printed product had the best gumminess parameter. In order to get a better printed product, the effects of printing parameters (nozzle diameter (Dn), extrusion rate (Vd) and nozzle moving speed (Vn)) on material printing performance and product formability was tested. When Dn, Vd, Vn were = 1.2 mm, 20 mm3/s, 25 mm/s, respectively, the printed product was having similar to the target product, with less breakage and less the changing of shape. Overall results show that 3D printing technology is a rising method for producing N. sphaeroides-based new products.
相似文献Pluchea lanceolata (DC.) C.B. Clarke is a threatened native medicinal plant. Increasing the propagation of this plant will preserve the wild population and provide material for medicinal use. In vitro and field-collected shoots and leaves were tested for response to 2,4-dichlorophenoxyacetic acid (2,4-D) and thidiazuron (TDZ), for initiation of direct shoot regeneration (DSR), or direct somatic embryogenesis (DSE). Leaves and internodes collected from field-grown plants produced only callus, while in vitro–raised shoots exhibited DSR and DSE on Murashige and Skoog (MS) medium with 2,4-D and TDZ. Direct shoot regeneration occurred on medium with TDZ from internode and leaf segments obtained from in vitro–developed shoots. In vitro–grown shoots were rooted on half-strength MS medium with 2 mg L−1 indole-3-butyric acid and acclimatized. Survival in natural conditions was 62.5% for DSE and 79% for DSR plantlets.
相似文献In this study, linear and mass attenuation coefficients of fabricated particleboards intended for use as phantom material were estimated using 137Cs and 60Co radiation sources. Particleboards made of Rhizophora spp. wood trunk bonded with soy flour and lignin were fabricated at a target density of 1.0 g cm?3, with and without gloss finish coating. Elemental composition of the particleboards was obtained by means of energy dispersive X-ray (EDX) spectroscopy. Experimental setups were simulated via the GATE Monte Carlo (MC) package, with particle histories of 1?×?106–1?×?107. Linear and mass attenuation coefficients obtained from measurements and GATE simulations were compared and discussed. The percentage differences between the measured and simulated linear and mass attenuation coefficients of the samples were reasonably small (2.05–4.88% for 137Cs and 3.24–5.38% for 60Co). It is shown that all the particleboards have the potential to be used as phantom materials as the attenuation coefficients measured were in good agreement with those of water (calculated with XCOM) and with those simulated with the GATE toolkit. The use of gloss finish coating also did not show any significant effect on the attenuation coefficient of the phantom material. Verification of experimental results via GATE simulations has been shown crucial in providing reliable data for energy transmission studies. Based on the results achieved in this study, it is concluded that the studied material—Rhizophora spp. wood trunk bonded with soy flour and lignin including gloss finish coating—can be used in radiation dosimetry studies.
相似文献The organic non-crystalline medium of 5,6-dichloro-2-[[5,6-dichloro-1-ethyl-3-(4-sulfobutyl)-benzimidazol-2-ylidene]-propenyl]-1-ethyl-3-(4-sulfobutyl)-benzimidazolium hydroxide (TDBC) is emerging as possible alternative plasmonic material for noble metal in visible region. In this paper, a novel long-range surface exciton-polariton (LRSEP) sensor based on TDBC film covered with graphene is reported. To enhance the imaging sensitivity, the thickness of TDBC film and the number of graphene layers are optimized. The result shows that the optimized imaging sensitivity is enhanced to 3243 RIU−1 when ns = 1.34. Compared with the traditional noble metal film-based sensor, the proposed LRSEP sensor demonstrates that the imaging sensitivity has been greatly improved. This is the first study of the TDBC film-based LRSEP sensor, which we hope to support the potential development of chemical sensing and bio-sensing.
相似文献This is the first study where the pyrolysis of the freshwater macroalga Chara vulgaris was explored to reveal its bioenergy potential. The suitability of C. vulgaris to bioenergy conversion via pyrolysis was accessed in terms of kinetic triplet and thermodynamic parameters. For this purpose, pyrolysis experiments under a thermogravimetric scale were conducted at multiple heating rates (5, 10, and 20 °C min?1) in an inert atmosphere. The mass-loss profiles of C. vulgaris pyrolysis showed that there are two dominant decomposition stages that are related to distinct chemical components inside its structure and that directly affect the calculated kinetic triplet and thermodynamics parameters. The average activation energy obtained using isoconversional methods of Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Starink, and Friedman was in the range of 52.87–72.91 kJ mol?1 for the first decomposition stage and 156.14–174.65 kJ mol?1 for the second decomposition stage. The pyrolytic conversion of C. vulgaris initially follows a second-order reaction model (first decomposition stage), while in second decomposition stage is controlled by a second-order Avrami-Erofeev reaction model. The kinetic results derived from the non-isothermal decomposition of C. vulgaris proved its suitable characteristics for pyrolysis. Additionally, multi-stage kinetic interpretation was successfully attained based on two kinetic triplets, where reconstructed pyrolysis behavior correlated well with experimental pyrolysis behavior. The changes in enthalpy, Gibbs free energy, and entropy for first decomposition stage were 67.58±0.25 kJ mol?1, 180.77±5.30 kJ mol?1, and ?176.65±0.41 J mol?1 K?1, and for the second decomposition stage the values were 166.70±0.09 kJ mol?1, 285.51±1.29 kJ mol?1, and ?124.29±0.09 J mol?1 K?1, respectively. Based on thermodynamic aspects, C. vulgaris is particularly interesting for use as a raw material to produce biofuels and bioenergy.
相似文献To characterize a novel dimethoate amidohydrolase from Sphingomonas sp. DC-6.
ResultsA gene, dmhA, encoding the dimethoate amidohydrolase responsible for transforming dimethoate to dimethoate carboxylic acid and methylamine, was cloned from Sphingomonas sp. DC-6. Sequence analysis and molecular modeling indicate that DmhA shares 31–57 % amino acid sequence identities with other functionally confirmed amidohydrolase. DmhA was expressed in Escherichia coli BL21 (DE3) and purified by Ni–NTA affinity chromatography. The purified DmhA could hydrolyze 4-acetaminophenol, dimethoate and propanil. DmhA activity was optimal at 30 °C and pH 7.5. Hg2+, Zn2+, Cu2+, Cd2+, Tween 80, Triton X-100 or SDS strongly inhibited its activity. The K m and k cat values of DmhA for dimethoate are 0.02 mM and 1.2 s−1, respectively.
ConclusionsDmhA was confirmed to be a novel dimethoate amidohydrolase which could eliminate the toxicity of dimethoate, providing a novel gene resource for the development of pesticide-degrading enzyme preparation and mechanistic study of dimethoate hydrolysis.
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