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1.
Magn Reson Imaging ; 96: 85-92, 2023 02.
Article in English | MEDLINE | ID: mdl-36470451

ABSTRACT

The native T1 values of the myocardium provide valuable information for tissue characterization and assessment of cardiomyopathies. In this study, we proposed a novel hybrid MOLLI sequence for myocardial T1 mapping. Unlike the two groups of inversion-recovery sampling of the conventional MOLLI5(3 s)3 sequence, the hybrid MOLLI sequence consisted of an inversion-recovery block followed by a saturation-recovery block. Since the second block employed a saturation pulse to spoil the longitudinal magnetization, it did not require a waiting period as MOLLI5(3 s)3 did. As a result, the hybrid MOLLI required less acquisition time leading to a practical application for patients with breath-hold difficulties. Phantom and healthy subject experiments were performed to evaluate the proposed sequence against the MOLLI5(3 s)3 sequence. The phantom study showed that the heart-rate dependency of one variant of the hybrid MOLLI sequences, hbMOLLI4, was comparable to that of MOLLI5(3 s)3. In addition, both hbMOLLI4 and MOLLI53 derived T1 values under 2% variations with simulated heart rates from 50 to 90 beats-per-minute within the range of T1 values for myocardium and blood before contrast administration. Simulation results suggested slightly reduced T1 fitting precision in hbMOLLI4 compared with MOLLI5(3 s)3, but prominently better than saturation recovery. Bland-Altman analysis on accuracy assessment revealed that hbMOLLI4 partially reduced the T1 underestimation of MOLLI5(3 s)3. In the human study, The T1 values of both methods were consistent (hbMOLLI4 vs. MOLLI5(3 s)3, slope = 1.14, R2 > 0.97), with equal reproducibility. The results supported that hybrid MOLLI produced comparable T1 mapping results in terms of accuracy, reproducibility, and heart-rate dependency, at the expense of slightly reduced precision. We concluded that the hybrid MOLLI sequence presents a competitive alternative to the MOLLI5(3 s)3 sequence when a speedy acquisition is required.


Subject(s)
Cardiomyopathies , Magnetic Resonance Imaging , Humans , Reproducibility of Results , Magnetic Resonance Imaging/methods , Heart/diagnostic imaging , Myocardium , Phantoms, Imaging
2.
Front Cardiovasc Med ; 9: 992284, 2022.
Article in English | MEDLINE | ID: mdl-36277786

ABSTRACT

The purpose of the present article is to identify intrinsic genes across general hypertension (HT), hypertension with left ventricular remodeling (HT-LVR), and uncontrolled hypertension (UN-HT). In total, four microarray datasets (GSE24752, GSE75360, GSE74144, and GSE71994) were downloaded from the GEO database and were used to identify differentially expressed genes (DEGs), respectively. Furthermore, gene set enrichment analysis (GSEA) was utilized to screen for significantly enriched biological pathways across the four datasets above, respectively. Furthermore, weighted gene co-expression network analysis (WGCNA) and functional enrichment analysis were applied to screen out gene modules of interest and potential biological functions, respectively. Finally, a Metascape-based multiple gene list meta-analysis was used to investigate intrinsic genes at different stages of the progression of hypertension. A total of 75 DEGs (63 upregulated genes and 12 downregulated genes, GSE24752) and 23 DEGs (2 upregulated genes and 21 downregulated genes, GSE74144) were identified. However, there were few DEGs identified in GSE75360, GSE71994, and part of the GSE74144 datasets. GSEA and functional enrichment of gene module of interest have indicated that "Heme metabolism," "TNF alpha/NFkB," and "interferon alpha response signaling," and MYC target v1/v2 were enriched significantly in different stages of hypertension progression. Significantly, findings from the multiple gene list meta-analysis suggested that FBXW4 and other 13 genes were unique to the hypertension group, and TRIM11 and other 40 genes were mainly involved in hypertension with the left ventricular remodeling group, while the other 18 genes including F13A1 significantly enriched in uncontrolled hypertension. Collectively, the precise switch of the "immune-metabolic-inflammatory" loop pathway was the most significant hallmark across different stages of hypertension, thereby providing a potential therapeutic target for uncontrolled hypertension treatment.

3.
Front Pharmacol ; 13: 877898, 2022.
Article in English | MEDLINE | ID: mdl-35677445

ABSTRACT

Temporal lobe epilepsy (TLE) is characterized as an impaired ability of learning and memory with periodic and unpredictable seizures. Status epilepticus (SE) is one of the main causes of TLE. Neuroinflammation and oxidative stress are directly involved in epileptogenesis and neurodegeneration, promoting chronic epilepsy and cognitive deficit. Previous studies have shown that ursolic acid (UA) represses inflammation and oxidative stress, contributing to neuroprotection. Herein, we demonstrated that UA treatment alleviated seizure behavior and cognitive impairment induced by epilepsy. Moreover, UA treatment rescued hippocampal neuronal damage, aberrant neurogenesis, and ectopic migration, which are commonly accompanied by epilepsy occurrence. Our study also demonstrated that UA treatment remarkably suppressed the SE-induced neuroinflammation, evidenced by activated microglial cells and decreased inflammation factors, including TNF-α and IL-1ß. Likewise, the expression levels of oxidative stress damage markers and oxidative phosphorylation (OXPHOS) enzyme complexes of mitochondria were also remarkably downregulated following the UA treatment, suggesting that UA suppressed the damage caused by the high oxidative stress and the defect mitochondrial function induced by SE. Furthermore, UA treatment attenuated GABAergic interneuron loss. In summary, our study clarified the notable anti-seizure and neuroprotective properties of UA in pilocarpine-induced epileptic rats, which is mainly achieved by abilities of anti-inflammation and anti-oxidation. Our study indicates the potential advantage of UA application in ameliorating epileptic sequelae.

4.
BMC Nephrol ; 23(1): 139, 2022 04 11.
Article in English | MEDLINE | ID: mdl-35410141

ABSTRACT

BACKGROUND: Minimal change disease (MCD) is a common cause of the nephrotic syndrome. Several studies have shown an increased incidence of cancer in patients with MCD. However, there are no reports on the association between MCD and gastrointestinal stromal tumor (GIST). CASE PRESENTATION: We report a case of a 66-year-old female with severe nephrotic syndrome and concomitant duodenal GIST. Immunoglobulin test showed a significant increase of IgE levels. The diagnosis of renal histopathology was MCD with subacute tubulointerstitial injury. The combination of preoperative Imatinib mesylate chemotherapy and tumor excision was accompanied by significant remission of proteinuria, and IgE level decreasing, without immunosuppressivetherapy. CONCLUSIONS: It is the first case report that MCD was associated with GIST and elevated IgE level. Clinically, in patients with elevated IgE level associated with nephrotic syndrome, the possibility of tumor must be taken into account when allergic factors are excluded.


Subject(s)
Gastrointestinal Stromal Tumors , Nephrosis, Lipoid , Nephrotic Syndrome , Aged , Female , Gastrointestinal Stromal Tumors/complications , Humans , Immunoglobulin E , Kidney/pathology , Nephrosis, Lipoid/complications , Nephrosis, Lipoid/diagnosis , Nephrosis, Lipoid/drug therapy , Nephrotic Syndrome/complications
5.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-880088

ABSTRACT

OBJECTIVE@#To establish a method for rapid detection and typing of NPM1 mutations in acute myeloid leukemia (AML) by fluorescence melting curve analysis technology.@*METHODS@#A pair of primers and a fluorescent single-stranded probe (molecule beacon) were designed for the mutant genes mutA, mutB, mutD in exon 12 of nucleopsin (NPM1) and wild type. With a real-time qPCR, the A, B, and D gene mutations of NPM1 were detected and typed by different-melting curve peak value of the probe through RT-PCR.@*RESULTS@#This method could detected the mutations of A, B, and D in NPM1 effectively with a sensitivity of 1%. Furthermore, 62 AML clinical samples were evaluated by the method. In the results, the detection rate and typing of NPM1 mutations were consistent with the sequencing results of clinical samples.@*CONCLUSION@#There are three features in the method of fluorescence melting curve analysis: stable PCR system, easy to operate, and the easily distinguishable results. The method might meet the demand for rapid typing of NPM1 gene mutation in early diagnosis or concomitant diagnosis of AML.


Subject(s)
Humans , Exons , Genotype , Leukemia, Myeloid, Acute/genetics , Mutation , Nuclear Proteins/genetics
6.
Front Behav Neurosci ; 14: 157, 2020.
Article in English | MEDLINE | ID: mdl-33324181

ABSTRACT

The role of estrogen receptors in neuroprotection and cognition has been extensively studied in humans over the past 20 years. Recently, studies have shifted their focus to the use of selective estrogen receptor modulators in the treatment of mental illnesses in the central nervous system. We conducted this study to test the behavioral changes shown by G protein-coupled estrogen receptor 1 knockout (GPER1 KO) and wild-type (WT) mice with MK-801-induced schizophrenia (SZ). GPER1 KO and WT mice received intraperitoneal injections of MK-801 for 14 continuous days. Behavioral, learning and memory, and social interaction changes were evaluated by using the IntelliCage system, open-field, three-chamber social interaction, and novel object recognition tests (NORT). The protein expression levels of the NR2B/CaMKII/CREB signaling pathway were tested via Western blot analysis. The KO SZ group was more likely to show impaired long-term learning and memory function than the WT SZ group. Learning and memory functions were also impaired in the KO Con group. MK-801 administration to the GPER1-KO and WT groups resulted in memory deficiencies and declining learning capabilities. GPER1 deficiency downregulated the expression levels of proteins related to the NR2B/CaMKII/CREB signaling pathway. Our study suggested that GPER1 played an important role in cognitive, learning, and memory functions in the MK-801-induced mouse model of SZ. The mechanism of this role might partially involve the downregulation of the proteins related to the NR2B/CaMKII/CREB signaling pathway. Further studies should focus on the effect of GPER1 on the pathogenesis of SZ in vivo and in vitro.

7.
Polymers (Basel) ; 10(4)2018 Mar 21.
Article in English | MEDLINE | ID: mdl-30966381

ABSTRACT

In the current study, the poly (amide-urethane) (PAUt) membranes were successfully fabricated by interfacial polymerization of m-phenylenediamine (MPD) and 5-choroformyloxyisophaloyl chloride (CFIC) on the polysulfone substrates. Two modification methods based on layer-by-layer assembly were applied to modify the PAUt membrane surface to achieve antifouling property: 1. Chitosan (CS) was directly self-assembled on the PAUt membrane (i.e., PAUt-CS); and 2. polydimethyl diallyl ammonium chloride (PDDA), polystyrene sulfonate (PSS), and CS were successively self-assembled on the membrane surface (i.e., PAUt-PDDA/PSS/CS). The resultant membranes were symmetrically characterized by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Contact Angle Meter (CAM), respectively. The results indicated that the modified membranes had much smoother and more hydrophilic surfaces as compared to the nascent PAUt membrane. Meanwhile, the modified membranes exhibited better reverse osmosis performance in terms of water permeability and salt rejection. After the modified membranes were fouled by lake water, the PAUt-PDDA/PSS/CS membrane presented the best antifouling performance among the three types of membranes. Combining the reverse osmosis performance with the anti-fouling property obviously, the PAUt-PDDA/PSS/CS membrane behaved as a promising candidate to be used in real applications.

8.
Polymers (Basel) ; 10(6)2018 Jun 20.
Article in English | MEDLINE | ID: mdl-30966720

ABSTRACT

In this study, modification of polysulfone (PSf)/sulfonated polysulfone (SPSf) blended porous ultrafiltration (UF) support membranes was proposed to improve the reverse osmosis (RO) performance of aromatic polyamide thin film composite (TFC) membranes. The synergistic effects of solvent, polymer concentration, and SPSf doping content in the casting solution were investigated systematically on the properties of both porous supports and RO membranes. SEM and AFM were combined to characterize the physical properties of the membranes, including surface pore natures (porosity, mean pore radius), surface morphology, and section structure. A contact angle meter was used to analyze the membrane surface hydrophilicity. Permeate experiments were carried out to evaluate the separation performances of the membranes. The results showed that the PSf/SPSf blended porous support modified with 6 wt % SPSf in the presence of DMF and 14 wt % PSf had higher porosity, bigger pore diameter, and a rougher and more hydrophilic surface, which was more beneficial for fabrication of a polyamide TFC membrane with favorable reverse osmosis performance. This modified PSf/SPSf support endowed the RO membrane with a more hydrophilic surface, higher water flux (about 1.2 times), as well as a slight increase in salt rejection than the nascent PSf support. In a word, this work provides a new facile method to improve the separation performance of polyamide TFC RO membranes via the modification of conventional PSf porous support with SPSf.

9.
RSC Adv ; 8(27): 15102-15110, 2018 Apr 18.
Article in English | MEDLINE | ID: mdl-35541356

ABSTRACT

In this work, a dendrimer trimesoyl amide amine (TMAAM) monomer was proposed to be used as a key functional monomer to modify the conventional aromatic polyamide thin-film composite (TFC) nanofiltration (NF) membrane, and a new kind of TMAAM-based semi-aromatic polyamide composite NF membrane was thus prepared by interfacial polymerization. The effects of the PIP/TMAAM ratio (PIP = piperazine) on the membrane chemical structure, surface properties and separation performances were investigated systematically. With the increase in TMAAM content loaded in the membrane, the water flux strongly increased but the salt rejection decreased only slightly. When the PIP/TMAAM ratio was 1, the membrane NF-2 exhibited a smoother and more hydrophilic surface, as a result of which it displayed an optimum separation performance for different valent salts. In addition, the TMAAM modified TFC membrane presented an extremely high rejection to negatively charged dye molecules and high permeation for monovalent salts, leading to good prospects for dye/salt separation application. Moreover, both the water flux and salt rejection of the TMAAM-based membrane were stable in a long-term running process, and the membrane showed a favourable anti-fouling property and efficient cleaning recovery. Therefore, this work provides a new type of semi-aromatic polyamide composite NF membrane fabricated by a facile and straightforward method via interfacial polymerization with high hydrophilicity, good stability and strong anti-fouling property.

10.
RSC Adv ; 8(66): 37817-37827, 2018 Nov 07.
Article in English | MEDLINE | ID: mdl-35558596

ABSTRACT

A novel reverse osmosis (RO) composite membrane, poly(amide-urethane-imide@Ag) (PAUI@Ag), was prepared on a polysulfone supporting film through two-step interfacial polymerization. First, in the 1st interfacial polymerization procedure, a new tri-functional crosslinking agent with -OCOCl and -COCl groups, 5-choroformyloxyisophaloyl chloride (CFIC), was reacted with 4-methyl-phenylenediamine (MMPD) without curing treatment to obtain the poly(amide-urethane) base membrane with a CFIC-MMPD precursor separation layer. And then N,N'-dimethyl-m-phenylenediamine (DMMPD) with nano-Ag particle dispersion was introduced onto the base membrane to further construct a CFIC-DMMPD modified ultrathin separation layer via the 2nd interfacial polymerization. Thus, the PAUI@Ag RO membrane with poly(amide-urethane-imide) bi-layer skin was obtained. The membrane was characterized for the chemical composition of separation layer, the membrane cross-section structure and the membrane surface morphology. Permeation experiment was employed to evaluate the PAUI@Ag membrane performance including salt rejection rate and water flux. The results revealed that the PAUI@Ag membrane composed the highly cross-linked separation layer with entire ridges and valleys, small surface roughness, and well dispersed nano-Ag particles. Upon exposure of the membranes to high concentration of free chlorine solutions, the PAUI@Ag RO membrane showed a slightly less chlorine-resistant property compared with the nascent PAUI RO membrane, but was still superior to the conventional polyamide MPD-TMC RO membrane, meanwhile it processed higher anti-biofouling property.

11.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-702333

ABSTRACT

Objective To investigate the relationship between the fasting blood glucose level and the severity of coronary artery disease among the Kazakh population in Xinjiang. Methods A total of 411 Kazakh patients with no known history of diabetes mellitus were enrolled in this study for highly suspected of coronary artery disease(CAD) and subesquently underwent coronary artery angiography. Coronary artery disease was diagnosed in 280 patients after coronary artery argiography. The severity of the disease was expressed in terms of Gensini score. All subjects were classified into 4 groups according to the level of fasting plasma glucose (FPG)< 5.6 mmol / L, 5.6-6.1 mmol / L, 6.1-7.0 mmol / L and ≥7.0 mmol / L. All the biochemical parameters, clinical data and coronary artery angiographic data were compared, and the possible risk factors related to the severity of coronary artery disease were studied. Results Multivariate logistic regression analysis showed that FPG was significantly associated with coronary artery disease(OR 1.53, 95% CI 1.25-1.87,P<0.001).The results showed that the prevalence of angiographic CAD and the Gensini score increased with the increasing FPG levels among the four groups.The FPG level was significantly correlated with the Gensini score (P<0.001). Conclusions FPG is significantly associated with coronary artery disease and its severity in the Kazakh population in Xinjiang.

12.
Org Biomol Chem ; 13(3): 686-90, 2015 Jan 21.
Article in English | MEDLINE | ID: mdl-25424983

ABSTRACT

A miscible tetrahydrofuran-tris buffer mixture has been used to fabricate polydopamine hollow capsules with a size of 200 nm and with a shell thickness of 40 nm. An unusual non-emulsion soft template mechanism has been disclosed to explain the formation of capsules. The results indicate that the capsule structure is highly dependent on the volume fraction of tetrahydrofuran as well as the solvent, and the shell thickness of capsules can be controlled by adjusting the reaction time and dopamine concentration.


Subject(s)
Dopamine/chemistry , Furans/chemistry , Indoles/chemical synthesis , Nanocapsules/chemistry , Polymers/chemical synthesis , Tromethamine/chemistry , Microscopy, Electron, Transmission , Nanocapsules/ultrastructure , Particle Size , Surface Properties , Time Factors
13.
Sensors (Basel) ; 14(7): 12968-89, 2014 Jul 18.
Article in English | MEDLINE | ID: mdl-25046019

ABSTRACT

Gravity matching navigation algorithm is one of the key technologies for gravity aided inertial navigation systems. With the development of intelligent algorithms, the powerful search ability of the Artificial Bee Colony (ABC) algorithm makes it possible to be applied to the gravity matching navigation field. However, existing search mechanisms of basic ABC algorithms cannot meet the need for high accuracy in gravity aided navigation. Firstly, proper modifications are proposed to improve the performance of the basic ABC algorithm. Secondly, a new search mechanism is presented in this paper which is based on an improved ABC algorithm using external speed information. At last, modified Hausdorff distance is introduced to screen the possible matching results. Both simulations and ocean experiments verify the feasibility of the method, and results show that the matching rate of the method is high enough to obtain a precise matching position.


Subject(s)
Algorithms , Artificial Intelligence , Technology/methods , Gravitation
14.
J Biotechnol ; 166(1-2): 12-9, 2013 Jun 20.
Article in English | MEDLINE | ID: mdl-23659800

ABSTRACT

A highly active and stable cross-linked enzyme aggregates (CLEAs) of epoxide hydrolases (EHs) from Mung bean, which plays a crucial role in synthesis of valuable enantiopure diols, were successfully prepared and characterized. Under the optimum preparation conditions, the activity recovery of CLEAs recorded 92%. The CLEAs were more efficient than the free enzyme in catalyzing asymmetric hydrolysis of styrene oxide to (R)-1-phenyl-1,2-ethanediol in organic solvent-containing biphasic system. The biocatalytic reaction performed in n-hexane/buffer biphasic system had a clearly faster initial reaction rate, much higher product yield and product e.e. value than that in aqueous medium. Moreover, the optimal volume ratio of n-hexane to buffer, reaction temperature, buffer pH value and substrate concentration for the enzymatic hydrolysis were found to be 1:1, 40 °C, 7.5 and 30 mM, respectively, under which the initial reaction rate, product yield and product e.e. value were 13.26 mM/h, 46% and 93.5%, respectively. The CLEAs retained more than 50% of their initial activity after 8 batches of re-use in phosphate buffer and maintained 53% of their original activity after 8 reaction cycle in biphasic system. The efficient biocatalytic process with CLEAs proved to be feasible on a 250-mL preparative scale, exhibiting great potential for asymmetric synthesis of chiral diols.


Subject(s)
Biocatalysis , Epoxide Hydrolases/chemistry , Epoxide Hydrolases/metabolism , Epoxy Compounds/metabolism , Fabaceae/enzymology , Cross-Linking Reagents/chemistry , Enzyme Activation , Enzyme Stability , Fabaceae/metabolism , Hexanes/metabolism , Hydrolysis , Recycling
15.
Article in English | WPRIM (Western Pacific) | ID: wpr-819741

ABSTRACT

OBJECTIVE@#To observe the expression changes of inflammatory markers TGF-β1, Smad3 and IL-6 in patients with atrial fibrillation (AF), and to explore the significance of TGF-β1 signaling pathway in the structural remodeling of AF.@*METHODS@#The expression of TGF-β1, Smad3 and IL-6 in 50 cases with AF and 30 normal cases were detected by RT-PCR and ELISA.@*RESULTS@#The TGF-β1, Smad3 and IL-6 mRNA and protein expression levels in patients with AF were significantly higher than that in the control group (P0.05). The TGF-β1mRNA expression in the ⩾ 50 years subgroup was significantly higher than that in the <50 years subgroups, and it was higher in the NYHA III subgroup than in the I/II grade subgroup. It was also higher in the left ventricular ejection fraction (LVEF) <50% subgroup than in LVEF ⩾ 50% group, and it was significantly higher in the AF time ⩾ 36 months subgroup than that in <36 months subgroup (P<0.05). The Smad3 and IL-6 expressions in the in the LVEF <50% subgroup were both high that than that in LVEF ⩾ 50% group, and higher in the AF time ⩾ 36 months subgroup than that in <36 months subgroup (P<0.05). There were a positive correlation between TGF-β1, Smad3 and IL-6 (r=0.687, r=0.547). There were also a positive correlation between Smad3 and IL-6 mRNA (r=0.823).@*CONCLUSIONS@#AF is associated with inflammation, and the inflammation is also involved in the fibrillation and sustain of AF. The TGF-β1 signal pathway may be involved in the process of atrial structural remodeling in patients with AF, and iss related with the occurrence and maintenance of AF.


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Atrial Fibrillation , Blood , Metabolism , Biomarkers , Blood , Case-Control Studies , Hemodynamics , Inflammation , Blood , Metabolism , Interleukin-6 , Blood , Genetics , Metabolism , Signal Transduction , Physiology , Smad3 Protein , Blood , Genetics , Metabolism , Transforming Growth Factor beta1 , Blood , Genetics , Metabolism
16.
J Biotechnol ; 162(2-3): 183-90, 2012 Dec 31.
Article in English | MEDLINE | ID: mdl-22995740

ABSTRACT

A comparative study was made of Mung bean epoxide hydrolases-catalyzed asymmetric hydrolysis of styrene oxide to (R)-1-phenyl-1,2-ethanediol in an n-hexane/buffer biphasic system containing various hydrophilic ionic liquids (ILs). Compared to the n-hexane/buffer biphasic system alone, addition of a small amount of hydrophilic ILs reduced the amount of non-enzymatic hydrolysis, and improved the reaction rate by up to 22%. The ILs with cation containing an alkanol group, namely [C(2)OHMIM][BF(4)] and [C(2)OHMIM][TfO], and the choline amino acid ILs [Ch][Arg] and [Ch][Pro] were found to be the most suitable co-solvents for the reaction, owing to their good biocompatibility with the enzyme, which led to high initial rates (0.99-1.25 µmol/min) and high product e.e.s (95%). When substrate concentration was around 30 mM, where optimal performance was observed with the IL-containing systems, the product e.e. was improved from 90% without ILs to ≥95% in the presence of ILs.


Subject(s)
Epoxide Hydrolases/chemistry , Epoxy Compounds/chemistry , Fabaceae/enzymology , Ionic Liquids/chemistry , Biotechnology , Epoxide Hydrolases/isolation & purification , Epoxide Hydrolases/metabolism , Epoxy Compounds/metabolism , Fabaceae/chemistry , Hydrogen-Ion Concentration , Hydrolysis/drug effects , Hydrophobic and Hydrophilic Interactions , Imidazoles/chemistry , Imidazoles/pharmacology , Ionic Liquids/pharmacology , Temperature
17.
J Biotechnol ; 155(2): 203-8, 2011 Sep 10.
Article in English | MEDLINE | ID: mdl-21745503

ABSTRACT

An enzymatic regioselective approach for the glucosylation of a series of 2'-deoxynucleosides was described by using the crude ß-glycosidase from bovine liver that is less expensive and can be simply prepared in a standard organic laboratory. With the glucosylation of 2'-deoxyuridine as a model reaction, the effects of several key factors on the enzymatic reaction were examined. The optimum enzyme dosage, buffer pH and temperature were 0.05U/ml, 9.5 and 42°C, respectively. The presence of alkali ß-glycosidase as the main active component in the crude enzyme extract might account for the high glucosylation activity at pH 9.5. In addition, the desired 5'-O-glucosylated derivatives of 2'-deoxynucleosides were synthesized with the yields of 22-72% and exclusive 5'-regioselectivities (>99%).


Subject(s)
Liver/enzymology , Nucleosides/biosynthesis , Nucleosides/metabolism , beta-Glucosidase/metabolism , Animals , Cattle , Chromatography, High Pressure Liquid , Disaccharides/metabolism , Glycosylation , Hydrogen-Ion Concentration , Magnetic Resonance Spectroscopy , Molecular Structure , Nucleosides/chemistry , Temperature , beta-Glucosidase/chemistry
18.
J Phys Chem A ; 115(12): 2615-26, 2011 Mar 31.
Article in English | MEDLINE | ID: mdl-21388113

ABSTRACT

Hydrogen peroxide (HP) clusters (H(2)O(2))(n) (n = 1-6) and liquid-state HP have been systemically investigated by the newly constructed ABEEM/MM fluctuating charge model. Because of the explicit description of charge distribution and special treatment of the hydrogen-bond interaction region, the ABEEM/MM potential model gives reasonable properties of HP clusters, including geometries, interaction energies, and dipole moments, when comparing with the present ab initio results. Meanwhile, the average dipole moment, static dielectric constant, heats of vaporization, radial distribution function, and diffusion constant for the dynamic properties of liquid HP at 273 K and 1 atm are fairly consistent with the available experimental data. To the best of our knowledge, this is the first theoretical investigation of condensed HP. The properties of HP monomer are studied in detail involving the structure, torsion potentials, molecular orbital analysis, charge distribution, dipole moment, and vibrational frequency.


Subject(s)
Electrons , Hydrogen Peroxide/chemistry , Molecular Dynamics Simulation , Diffusion , Dimerization , Molecular Conformation , Quantum Theory
19.
J Chem Theory Comput ; 6(3): 795-804, 2010 Mar 09.
Article in English | MEDLINE | ID: mdl-26613307

ABSTRACT

A polarizable force field (PFF) using multiple fluctuating charges per atom, ABEEMσπ PFF, is presented in this work. The fluctuating partial charges are obtained from the electronegativity equalization principle applied to the decomposition scheme of atom-bond regions into multiple charge sites: atomic, lone-pair electron, and σ and π bond regions. These multiple partial charges per atom should better account for the polarization effect than single atomic charge in other PFFs. To evaluate the PFF, structural and energetic properties for some organic and biochemical systems, including rotational barriers; binding energies of base pairs; a base-base interaction in a B-DNA decamer; and interaction energies of ten stationary conformers of a water dimer, peptides, and bases with water molecules, have been calculated and compared with the experimental data or ab initio MP2 results. Molecular dynamics simulations using the PFF have been performed for crambin and BPTI protein systems. Better performances in modeling root-mean-square deviations of backbone bond lengths, bond angles, key dihedral angles, the coordinate root-mean-square shift of atoms, and the distribution of hydrogen bonds have been observed in comparison with other PFFs. These results indicate that the fluctuating charge force field, ABEEMσπ/MM, is accurate and reliable and can be applied to wide ranges of organic and biomolecular systems.

20.
Chinese Journal of Cardiology ; (12): 716-719, 2010.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-244180

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the accuracy and practicability of detecting viable myocardium by CARTO voltage mapping in swine model of acute myocardial infarction (MI).</p><p><b>METHODS</b>MI was induced in 13 anesthetized swines via occluding the distal of left anterior descending coronary arteries by angioplasty balloon for 60-90 minutes. The viable myocardium detection by CARTO voltage mapping was made after reconstruction of the left ventricle using CARTO and the results were compared with TTC staining. The standard of CARTO voltage to detect viable myocardium was 0.5 - 1.5 mV while viable myocardium showed pink color by TTC staining.</p><p><b>RESULTS</b>Eleven out of 13 swines survived the operation and 2 swines died of ventricular fibrillation at 45 and 65 minutes post ischemia. Left ventricle was divided into 16 segments and 176 segments from 11 swines were analyzed. Viable myocardium detected by CARTO voltage mapping was identical as identified by TTC staining (Kappa = 0.816, P < 0.001). Taken the TTC result as standard, the sensitivity, specificity and accuracy rate of CARTO voltage mapping are 71.8%, 96.5% and 90.9% respectively.</p><p><b>CONCLUSION</b>CARTO voltage mapping could be used as a reliable tool to detect viable myocardium in this model.</p>


Subject(s)
Animals , Female , Male , Cell Survival , Disease Models, Animal , Electrophysiologic Techniques, Cardiac , Myocardial Infarction , Myocardium , Cell Biology , Swine
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