213 research outputs found
Enhancement of UV-assisted TiO2 degradation of ibuprofen using Fenton hybrid process at circumneutral pH
A synergistic UV/TiO2/Fenton (PCF) process is investigated for the degradation of ibuprofen (IBP) at circumneutral pH. The IBP decay in the PCF process is much faster than that with the conventional UV, UV/H2O2, Fenton, photo-Fenton, and photocatalysis processes. The kinetics analysis showed that the IBP decay follows a two-stage pseudo-first order profile, that is, a fast IBP decay (k(1)) followed by a slow decay (k(2)). The effects of various parameters, including initial pH level, dosage of Fenton's reagent and TiO2, wavelength of UV irradiation, and initial IBP concentration, are evaluated. The optimum pH level, [Fe2+](0), [Fe2+](0)/[H2O2](0) molar ratio, and [TiO2](0) are determined to be approximately 4.22, 0.20 mmol/L, 1/40, and 1.0 g/L, respectively. The IBP decay at circumneutral pH (i.e., 6.0-8.0 for wastewater) shows the same IBP decay efficiency as that at the optimum pH of 4.22 after 30 min, which suggests that the PCF process is applicable for the treatment of wastewater in the circumneutral pH range. The lnk(1) and lnk(2) are observed to be linearly correlated to 1/pH(0), [IBP](0), [H2O2](0), [H2O2](0)/[Fe2+](0) and ln[TiO2](0). Mathematical models are therefore derived to predict the IBP decay. (C) 2018, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved
Enhanced photocatalytic degradation of ciprofloxacin over Bi2O3/(BiO)(2)CO3 heterojunctions: Efficiency, kinetics, pathways, mechanisms and toxicity evaluation
In this study, the degradation of antibiotic ciprofloxacin (CIP) over Bi2O3/(BiO)(2)CO3 heterojunctions under simulated solar light irradiation (SSL-Bi2O3/(BiO)(2)CO3) was examined for the first time. The results showed that the Bi2O3/(BiO)(2)CO3 heterojunctions dramatically improved CIP decay efficiency. The effect of parameters showed that the CIP decay was optimized with the Bi2O3/(BiO)(2)CO3 dosage of 0.5 g/L and a wide pH range of 4.0-8.3, based on which, a kinetic model was derived to predict the remaining CIP concentration. It was found that the presence of anions like SO42-, NO3- and HCO3- decelerated the CIP decay, while the co-existence of Cl- accelerated the CIP decay. Six degradation intermediates were identified by ultra-performance liquid chromatography coupled with mass analyzer (UPLC/MS) and ion chromatographic (IC) analysis, and the decay pathways and degradation mechanism of CIP were proposed by combining the experiment data with theoretical calculation of frontier electron densities. Hydroxyl radical's reaction, photo-hole (h(+)) oxidation and reductive defluorination were found to involve in the CIP decay. The efficient alleviation on total organic carbon (TOC) and toxicity indicated that the complete mineralization and de-toxicity are possible by this system with sufficient reaction time
Cloning, over-expression, and characterization of a new carboxypeptidase A gene of Bacillus pumilus ML413 in Bacillus subtilis 168
Carboxypeptidase A (CPAs) are a well-studied group of zinc-containing exopeptidases that facilitate thebreakdown of proteins and peptides during metabolism. Carboxypeptidase A is typically produced in mammalian pancreatic, brain and other tissues. A new gene encoding carboxypeptidase A in the prokaryote Bacillus pumilus was amplified by polymerase chain reaction (PCR), ligated into the shuttle vector pMA5, and cloned in a GRAS bacteria-Bacillus subtilis 168 host. This gene sequence contained a 1621 bp open reading frame that encodes a protein of 540 amino acids. The optimum pH and temperature for enzyme activity were 7.5 and 50°C, respectively. The enzyme was quite stable at neutral pH and maintained about 65% activity following a 24 h incubation at 40°C. The Km of this CPA was 0.1 mM, much higher than in mammalian species. Glycerol, ammonium sulfate, and sodium citrate improved enzyme activity under optimal culture condition. The carboxypeptidase activity in recombinant B. subtilis 168 reached a maximum of 179 U ml-1 in a 5 L fermentator when cultured on improved medium. The over expression of carboxypeptidase A in Bacillus subtilis has commercial applications.Key words: Bacillus pumilus, Bacillus subtilis 168, over-expression, orthogonal arrays, carboxypeptidase A,metallocarboxypeptidase
Cocaine- and amphetamine-regulated transcript promotes the differentiation of mouse bone marrow-derived mesenchymal stem cells into neural cells
<p>Abstract</p> <p>Background</p> <p>Neural tissue has limited potential to self-renew after neurological damage. Cell therapy using BM-MSCs (bone marrow mesenchymal stromal cells) seems like a promising approach for the treatment of neurological diseases. However, the neural differentiation of stem cells influenced by massive factors and interactions is not well studied at present.</p> <p>Results</p> <p>In this work, we isolated and identified MSCs from mouse bone marrow. Co-cultured with CART (0.4 nM) for six days, BM-MSCs were differentiated into neuron-like cells by the observation of optical microscopy. Immunofluorescence demonstrated that the differentiated BM-MSCs expressed neural specific markers including MAP-2, Nestin, NeuN and GFAP. In addition, NeuN positive cells could co-localize with TH or ChAT by double-labled immunofluorescence and Nissl bodies were found in several differentiated cells by Nissl stain. Furthermore, BDNF and NGF were increased by CART using RT-PCR.</p> <p>Conclusion</p> <p>This study demonstrated that CART could promote the differentiation of BM-MSCs into neural cells through increasing neurofactors, including BNDF and NGF. Combined application of CART and BM-MSCs may be a promising cell-based therapy for neurological diseases.</p
Gene therapy for C-26 colon cancer using heparin-polyethyleneimine nanoparticle-mediated survivin T34A
Ling Zhang1,*, Xiang Gao1,2,*, Ke Men1, BiLan Wang1, Shuang Zhang1, Jinfeng Qiu1, Meijuan Huang1, MaLing Gou1, Ning Huang2, ZhiYong Qian1, Xia Zhao1, YuQuan Wei11State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, 2Department of Pathophysiology, College of Preclinical and Forensic Medical Sciences, Sichuan University, Chengdu, People&rsquo;s Republic of China*These authors contributed equally to this workBackground: Gene therapy provides a novel method for the prevention and treatment of cancer, but the clinical application of gene therapy is restricted, mainly because of the absence of an efficient and safe gene delivery system. Recently, we developed a novel nonviral gene carrier, ie, heparin-polyethyleneimine (HPEI) nanoparticles for this purpose.Methods and results: HPEI nanoparticles were used to deliver plasmid-expressing mouse survivin-T34A (ms-T34A) to treat C-26 carcinoma in vitro and in vivo. According to the in vitro studies, HPEI nanoparticles could efficiently transfect the pGFP report gene into C-26 cells, with a transfection efficiency of 30.5% &plusmn; 2%. Moreover, HPEI nanoparticle-mediated ms-T34A could efficiently inhibit the proliferation of C-26 cells by induction of apoptosis in vitro. Based on the in vivo studies, HPEI nanoparticles could transfect the Lac-Z report gene into C-26 cells in vivo. Intratumoral injection of HPEI nanoparticle-mediated ms-T34A significantly inhibited growth of subcutaneous C-26 carcinoma in vivo by induction of apoptosis and inhibition of angiogenesis.Conclusion: This research suggests that HPEI nanoparticle-mediated ms-T34A may have a promising role in C-26 colon carcinoma therapy.Keywords: gene therapy, mouse survivin-T34A, colon cancer, polyethyleneimine, nanoparticles, cancer therap
Refractory wheezing in Chinese children under 3 years of age: bronchial inflammation and airway malformation
CCA-Secure Deterministic Identity-Based Encryption Scheme
Deterministic public-key encryption, encrypting a plaintext into a unique ciphertext without involving any randomness, was introduced by Bellare, Boldyreva, and O'Neill (CRYPTO 2007) as a realistic alternative to some inherent drawbacks in randomized public-key encryption. Bellare, Kiltz, Peikert and Waters (EUROCRYPT 2012) bring deterministic public-key encryption to the identity-based setting, and propose deterministic identity-based encryption scheme (DIBE). Although the construc- tions of chosen plaintext attack (CPA) secure DIBE scheme have been studied intensively, the construction of chosen ciphertext attack (CCA) secure DIBE scheme is still challenging problems. In this paper, we introduce the notion of identity-based all-but-one trapdoor functions (IB-ABO-TDF), which is an extension version of all-but-one lossy trapdoor function in the public-key setting. We give a instantiation of IB-ABO-TDF under decisional linear assumption. Based on an identity-based lossy trapdoor function and our IB-ABO-TDF, we present a generic construction of CCA-secure DIBE scheme
Flower development and a functional analysis of related genes in Impatiens uliginosa
Impatiens uliginosa is a plant of the Impatiens, with peculiar flowers. In this study, we combined morphogenesis and molecular biology to explore its development of flowers. An analysis of basic observational data and paraffin sectioning showed that it took approximately 13 d for the floral organs to differentiate. An analysis of the development of inflorescences and floral organs by scanning electron microscopy showed that the inflorescence of I. uliginosa is a spiral raceme. The floral organs differentiated in the following order: lateral sepals (Ls), posterior sepal (Ps), anterior sepals (As), anterior petal (Ap), lateral petals (Lp), stamens (St) and gynoecium (Gy). I. uliginosa was found to have four sepals, and the connate stamens are caused by the fusion and growth of filament appendages. The results of fluorescence quantification and virus-induced gene silencing showed that I. uliginosa had its own unique model for flower development, and there was functional diversity of IuAP1 and IuDEF. Among them, IuAP1 controls the formation of bract s (Br), regulates the morphogenesis of posterior sepal, controls the anthocyanin precipitation of the anterior petals and the formation of lateral petals. IuDEF regulates the morphogenesis of lateral sepals, the length of development of the spur, and controls the size of yellow flower color plaques of the lateral petals. In this study, the process of flower development and the function of flower development genes of I. uliginosa were preliminarily verified. This study provides basic guidance and new concepts that can be used to study the development of Impatiens flowers
A novel stemness classification in acute myeloid leukemia by the stemness index and the identification of cancer stem cell-related biomarkers
BackgroundStem cells play an important role in acute myeloid leukemia (AML). However, their precise effect on AML tumorigenesis and progression remains unclear.MethodsThe present study aimed to characterize stem cell-related gene expression and identify stemness biomarker genes in AML. We calculated the stemness index (mRNAsi) based on transcription data using the one-class logistic regression (OCLR) algorithm for patients in the training set. According to the mRNAsi score, we performed consensus clustering and identified two stemness subgroups. Eight stemness-related genes were identified as stemness biomarkers through gene selection by three machine learning methods.ResultsWe found that patients in stemness subgroup I had a poor prognosis and benefited from nilotinib, MK-2206 and axitinib treatment. In addition, the mutation profiles of these two stemness subgroups were different, which suggested that patients in different subgroups had different biological processes. There was a strong significant negative correlation between mRNAsi and the immune score (r= -0.43, p<0.001). Furthermore, we identified eight stemness-related genes that have potential to be biomarkers, including SLC43A2, CYBB, CFP, GRN, CST3, TIMP1, CFD and IGLL1. These genes, except IGLL1, had a negative correlation with mRNAsi. SLC43A2 is expected to be a potential stemness-related biomarker in AML.ConclusionOverall, we established a novel stemness classification using the mRNAsi score and eight stemness-related genes that may be biomarkers. Clinical decision-making should be guided by this new signature in prospective studies
- …