Many fields,such as neuroscience,are experiencing the vast prolife ration of cellular data,underscoring the need fo r organizing and interpreting large datasets.A popular approach partitions data into manageable subse...Many fields,such as neuroscience,are experiencing the vast prolife ration of cellular data,underscoring the need fo r organizing and interpreting large datasets.A popular approach partitions data into manageable subsets via hierarchical clustering,but objective methods to determine the appropriate classification granularity are missing.We recently introduced a technique to systematically identify when to stop subdividing clusters based on the fundamental principle that cells must differ more between than within clusters.Here we present the corresponding protocol to classify cellular datasets by combining datadriven unsupervised hierarchical clustering with statistical testing.These general-purpose functions are applicable to any cellular dataset that can be organized as two-dimensional matrices of numerical values,including molecula r,physiological,and anatomical datasets.We demonstrate the protocol using cellular data from the Janelia MouseLight project to chara cterize morphological aspects of neurons.展开更多
It has been reported that there is an interaction between Benzo[a]pyrene （BaP）, a widespread carcinogenic polycyclic aromatic hydrocarbon, and tributyltin （TBT）, an organometal used as an antifouling biocide. This...It has been reported that there is an interaction between Benzo[a]pyrene （BaP）, a widespread carcinogenic polycyclic aromatic hydrocarbon, and tributyltin （TBT）, an organometal used as an antifouling biocide. This study was therefore designed to examine the potential in vivo influence of BaP, TBT and their mixture on splenic antioxidant defense systems of Sebastiscus marmoratus. The fish were exposed to water containing environmentally relevant concentrations of BaP, TBT and their mixture. Spleens were collected for biochemical analysis after exposure for 7, 25, 50 d and after recovery for 7, 20 d. Cotreatment with BaP and TBT for 7 d potentiated the induction of glutathione peroxidase （GPx） activity by BaP or TBT alone. The cotreatment for 25 and 50 d resulted in inhibition of GPx activity, which was similar to the effect of TBT. Splenic glutathione S-transferase （GST） activities were significantly elevated in S. marmoratus exposed to BaP starting from 7 d and remained high up to 25 d. However, no further activity change was found with prolonged exposure. Cotreatment of BaP and TBT primarily inhibited the GST activity, which was similar to the effect of TBT. Cotreatment with BaP and TBT for 25 or 50 d potentiated the depletion of GSH （glutathione） by BaP or TBT alone. MDA （malondialdehyde） contents in spleen of S. marmoratus were not significantly altered compared with the control during the test period. Spleen, as an immune organ, is sensitive to exposure of BaP or TBT. It should have an effective mechanism to counteract oxidative damage. Antioxidative defense systems in spleen of S. marmoratus should be considered as potential biomarkers. Short-term exposure of BaP or TBT could result in induction of antioxidant defense system. A significant decrease of these indices, such as GSH, GST, GPx might indicate more severe contamination.展开更多
AIM： To investigate the effect of a Chinese medicine, Kaiyu Qingwei Jianji （KYQWJJ） used for diabetic treatment, on the morphometry and residual strain distribution of the small intestine in streptozotocin （STZ） ...AIM： To investigate the effect of a Chinese medicine, Kaiyu Qingwei Jianji （KYQWJJ） used for diabetic treatment, on the morphometry and residual strain distribution of the small intestine in streptozotocin （STZ） -induced diabetic rats. Correlation analysis was also performed between the opening angle and residual strain with the blood glucose level. METHODS： Forty-two male Wistar rats weighing 220-240 g were included in this study. Thirty-two STZ- induced diabetic rats were subdivided into four groups （n = 8 in each group）, i.e. diabetic control group （DM）; high dose of KYQWJJ （T1, 36g/kg per day）; low dose of KYQWJJ （T2, 17 g/kg per day） and Gliclazide （T3, 50 mg/kg per day）. Another ten rats were used as nondiabetic control （CON）. The medicines were poured directly into stomach lumen by gastric lavage twice daily. The rats of CON and DM groups were only poured the physiological saline. Blood glucose and plasma insulin levels were measured. Experimental period was 35 d. At the end of experiment, three 5-cm long segments were harvested from the duodenum, jejunum and ileum. Three rings of 1-2 mm in length for no-load and zero-stress state tests were cut from the middle of different segments. The morphometric data, such as the circumferential length, the wall thickness and the opening angle were measured from the digitized images of intestinal segments in the no-load state and zerostress state. The residual strain was computed from the morphometry data. Furthermore, the linear regression analysis was performed between blood glucose level with morphometric and biomechanical data in the different intestinal segments. RESULTS： The blood glucose level of DM group was consistent 4-fold to 5-fold higher than those in CON group during the experiment （16.89 ± 1.11 vs 3.44 ± 0.15 mmol/L, P 〈 0.001）. The blood glucose level in the T1 （16.89 ± 1.11 vs 11.08 ± 2.67 mmol/L, P 〈 0.01） and T3 groups （16.89 ± 1.11 vs 13.54 ± 1.73 mmol/L, P 〈 0.05）, but not in T2 group （P 〉 0.05） was significantly lower than those in DM group. The plasma insulin levels of DM, T1, T2 and T3 groups were significantly lower than those in CON group （10.98 ± 1.02, 12.52 ± 1.42,13.54 ± 1.56,10.96 ± 0.96 vs 17.84 ± 2.34 pmol/L respectively, P 〈 0.05）, but no significantly difference among the groups with exception of CON group. The wet weight/cm and total wall thickness of duodenum, jejunum and ileum in DM group were significantly higher than those in CON group （wet weight （g/cm）： duodenum 0.209 ± 0.012 vs 0.166 ± 0.010, jejunum 0.149 ± 0.008 vs 0.121 ± 0.004, ileum 0.134 ± 0.013 vs 0.112 ± 0.007; Wall thickness （mm）： duodenum 0.849 ± 0.027 vs 0.710 ± 0.026, jejunum 0.7259 ± 0.034 vs 0.627 ± 0.025, ileum 0.532 ± 0.023 vs 0.470 ± 0.010, all P 〈 0.05）, T1 and T3 treatment could partly restore change of wall thickness, but T2 could not. The opening angle and absolute value of inner and outer residual stain were significantly smaller in duodenal segment （188 ± 11 degrees, -0.31 ± 0.02 and 0.35 ± 0.03 vs 259 ± 15 degrees, -0.40 ± 0.02 and 0.43 ± 0.05） and larger in jejunal （215 ± 20 degrees, -0.30 ± 0.03 and 0.36 ± 0.06 vs 172 ± 19 degrees, -0.25 ± 0.02 and 0.27 ± 0.02） and ileal segments （183 ± 20 degrees, -0.28 ± 0.01 and 0.34 ± 0.05 vs 153 ± 14 degrees, -0.23 ± 0.03 and 0.29 ± 0.04） in DM group than in CON group （P 〈 0.01）. TI and T3 treatment could partly restore this biomechanical alteration, but strong effect was found in T1 treatment （duodenum 243 ± 14 degrees, -0.36 ± 0.02 and 0.42 ± 0.06, jejunum 180 ± 15 degrees, -0.26 ± 0.03 and 0.30 ± 0.06 and ileum 163 ± 17 degrees, -0.23 ± 0.03 and 0.30 ± 0.05, compared with DM, P 〈 0.05）. The linear association was found between the glucose level with most morphometric and biomechanical data. CONCLUSION： KYQWJJ （high dose） treatment could partly restore the changes of blood glucose level and the remodeling of morphometry and residual strain of small intestine in diabetic rats. The linear regression analysis demonstrated that the effect of KYQWJJ on intestinal opening angle and residual strain is partially through its effect on the blood glucose level.展开更多
The non-edible crude rice bran oil was extracted from white rice bran, and then was catalyzed by immobilized lipase for biodiesel production in this study. The effects of water content, oil/methanol molar ratio, tempe...The non-edible crude rice bran oil was extracted from white rice bran, and then was catalyzed by immobilized lipase for biodiesel production in this study. The effects of water content, oil/methanol molar ratio, temperature, enzyme amount, solvent,number of methanol added times and two-step methanolysis by using Candida sp. 99-125 as catalyst were investigated. The optimal conditions for processing 1 g rice bran oil were: 0.2 g immobilized lipase, 2 ml n-hexane as solvent, 20% water based on the rice bran oil mass, temperature of 40 °C and two-step addition of methanol. As a result, the fatty acid methyl esters yield was 87.4%. The immobilized lipase was proved to be stable when it was used repeatedly for 7 cycles.展开更多
The antimicrobial and antioxidant effects of two spice extracts and their combination on raw chicken meat during storage for 15 days at 4◦C were studied.Raw chicken meat was treated with BHT(positive control),rosemary...The antimicrobial and antioxidant effects of two spice extracts and their combination on raw chicken meat during storage for 15 days at 4◦C were studied.Raw chicken meat was treated with BHT(positive control),rosemary(RO),cloves(CL),and their combination,and the results were compared to those obtained for raw chicken meat without any additive(negative control).The antioxidant and antimicrobial activities of spice extracts were determined.The total phenolic and total flavonoid contents of rosemary was lower than those of cloves.Cloves exhibited a higher DPPH radical scavenging activity than that of rosemary.However,the ferrous ion-chelating effect of rosemary was significantly higher than that of cloves.The pH,instrumental colour(CIE L*,a*,b*),total viable counts(TVC),lactic acid bacteria(LAB)counts,Enterobacteriaceae counts,Pseudomonas spp.counts and 2-thiobarbituric acid reactive substances(TBARS)were determined at 3-day intervals over a period of 15 days.The bacterial counts of T-RO-CL samples were lower than those of control samples during storage.T-RO-CL samples maintained significantly(P<0.05)higher L*,a*and b*values during storage.The TBARS values of T-RO-CL samples were the lowest among the samples.These results demonstrate that spice extracts are highly effective against microbial growth and lipid oxidation and show potential as a natural antioxidant in raw chicken meats.展开更多
The demand for biomaterials that promote the repair,replacement,or restoration of hard and soft tissues continues to grow as the population ages.Traditionally,smart biomaterials have been thought as those that respond...The demand for biomaterials that promote the repair,replacement,or restoration of hard and soft tissues continues to grow as the population ages.Traditionally,smart biomaterials have been thought as those that respond to stimuli.However,the continuous evolution of the field warrants a fresh look at the concept of smartness of biomaterials.This review presents a redefinition of the term“Smart Biomaterial”and discusses recent advances in and applications of smart biomaterials for hard tissue restoration and regeneration.To clarify the use of the term“smart biomaterials”,we propose four degrees of smartness according to the level of interaction of the biomaterials with the bio-environment and the biological/cellular responses they elicit,defining these materials as inert,active,responsive,and autonomous.Then,we present an up-to-date survey of applications of smart biomaterials for hard tissues,based on the materials’responses(external and internal stimuli)and their use as immune-modulatory biomaterials.Finally,we discuss the limitations and obstacles to the translation from basic research(bench)to clinical utilization that is required for the development of clinically relevant applications of these technologies.展开更多
As a new mutagenetic method, low-energy ion implantation has been used widely in many research areas in recent years. In order to obtain some industrial strains with high xylanase yield, the wild type strain Aspergill...As a new mutagenetic method, low-energy ion implantation has been used widely in many research areas in recent years. In order to obtain some industrial strains with high xylanase yield, the wild type strain Aspergillus niger A3 was mutated by means of nitrogen ions implantation （10 keV, 2.6× 10^14 ～ 1.56 × 10^15 ions/cm^2） and a mutant N212 was isolated subsequently. However, it was found that the initial screening means of the high-yielding xylanase strains such as transparent halos was unfit for first screening. Compared with that of the wild type strain, xylanase production of the mutant N212 was increased from 320 IU/ml to 610 IU/ml, and the optimum fermentation temperature was increased from 28 ℃ to 30 ℃.展开更多
The unicellular green alga Dunaliella salina is well adapted to salt stress and contains compounds（including β-carotene and vitamins） with potential commercial value.A large transcriptome database of D.salina durin...The unicellular green alga Dunaliella salina is well adapted to salt stress and contains compounds（including β-carotene and vitamins） with potential commercial value.A large transcriptome database of D.salina during the adjustment, exponential and stationary growth phases was generated using a high throughput sequencing platform.We characterized the metabolic processes in D.salina with a focus on valuable metabolites, with the aim of manipulating D.salina to achieve greater economic value in large-scale production through a bioengineering strategy.Gene expression profiles under salt stress verified using quantitative polymerase chain reaction（qPCR） implied that salt can regulate the expression of key genes.This study generated a substantial fraction of D.salina transcriptional sequences for the entire growth cycle, providing a basis for the discovery of novel genes.This first full-scale transcriptome study of D.salina establishes a foundation for further comparative genomic studies.展开更多
Hydrothermal reactions of biphenyl-2,3,3A,5A-tetracarboxylic acid（H4bptc） with cobalt salt in the presence of 1,4-bis（2-pyridylmethyl）piperazin（bpmp） afforded one novel coordination polymer, namely, [Co（H2bptc...Hydrothermal reactions of biphenyl-2,3,3A,5A-tetracarboxylic acid（H4bptc） with cobalt salt in the presence of 1,4-bis（2-pyridylmethyl）piperazin（bpmp） afforded one novel coordination polymer, namely, [Co（H2bptc）（bpmp）0.5（H2O）]n（1）. Its structure was established by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra and TG analysis. Complex 1 crystallizes in monoclinic, space group P21/c with a = 11.4839（11）, b = 16.6690（16）, c = 11.5559（11） A, V = 2201.8（4） A3, Mr = 539.35, Dc = 1.627 g/cm^3, μ（MoK α） = 0.841 mm-1, F（000） = 1108, Z = 4, the final R = 0.0309 and w R = 0.0705 for 4090 observed reflections（I 2σ（I））. Complex 1 displays a one-dimensional（1D） chain bridged by bpmp. Two carboxylic groups of H4 bptc ligand adopt μ01-η1：η1 and μ1-η1：η coordination modes to bridge adjacent Co（Ⅱ） ions together with bpmp ligand to give alternately arranged left- and right-handed helical chains. In addition, variable-temperature magnetic susceptibility measurements indicate that complex 1 shows weak antiferromagnetic interactions between the adjacent Co（Ⅱ） ions.展开更多
An assessment with assistance of DNA barcoding was conducted on green macroalgae in coastal zone around Qingdao, China, during the period of April- December, 2011. Three markers were applied in molecular discriminatio...An assessment with assistance of DNA barcoding was conducted on green macroalgae in coastal zone around Qingdao, China, during the period of April- December, 2011. Three markers were applied in molecular discrimination, including the plastid elongation factor tufA gene, the internal transcribed spacer(ITS) region of the ribosomal cistron and rubisco large subunit gene 3' regions(rbcL-3P). DNA barcoding discriminated 8 species, excluding species of genus Cladophora and Bryopsis due to failures in amplification. We ascertained and corrected 4 species identified by morphological methods for effectively assisting the classification. The gene tufA presented more advantages as an appropriate DNA marker with the strongest amplification success rate and species discrimination power than the other two genes. The poorest sequencing success largely handicapped the application of ITS. Samples identified by tufA and rbcL as Ulva flexuosa were clustered into the clade of U. prolifera by ITS in the neighbor-joining tree. Confusion with discrimination of the complex of U. linza, U. procera and U. prolifera(as the LPP complex) still existed for the three DNA markers. Based on our results, rbcL is recommended as a preferred marker for assisting tufA to discriminate green macroalgae. In distinguishing green-tide-forming Ulva species, the free-floating sample collected from the green tide in 2011 was proved to be identical with U. prolifera in Yellow Sea for ITS and rbcL genes. This study presents a preliminary survey of green macroalgae distributed in the coastal area around Qingdao, and proves that DNA barcoding is a powerful tool for taxonomy of green macroalgae.展开更多
This paper reviews some of the nanoindentation research that has been done on teeth and discusses the usefulness of this technique in studying the structure-property-function relationship at the micro and nanometer sc...This paper reviews some of the nanoindentation research that has been done on teeth and discusses the usefulness of this technique in studying the structure-property-function relationship at the micro and nanometer scale. In particular, examples on the use of nanoindentation technique in investigating the effects of cleansing and bleaching agents as well as drinks on the micro- and nanostructures and mechanical properties of teeth are highlighted. Although nanoindentation on teeth is a relatively new area of research, it provides an excellent way of probing and relating the structures and mechanical properties of teeth at the submicron and nanometer scales that were previously not possible but which can now greatly benefit dental research. For example, a nanoindenter with a high resolution imaging capability can help to elucidate the mechanisms with which certain diseases can damage and compromise the structural integrity of teeth at the micro- and nanometer scale. With this information, clinicians and researchers can then work towards how best to tackle these problems or even preventing them.展开更多
Extracellular polysaccharide from Tremella aurantialba (TEP) significantly inhibited H2O2-induced haemolysis of RBCs, significantly decreased the amount of malondialdehyde (MDA) produced in mice liver homogenates as a...Extracellular polysaccharide from Tremella aurantialba (TEP) significantly inhibited H2O2-induced haemolysis of RBCs, significantly decreased the amount of malondialdehyde (MDA) produced in mice liver homogenates as a result of autoxidation, and inhibited VitC-Fe2+-induced swelling of liver mitochondria.展开更多
A total of 142 specimens of Ceramiales （Rhodophyta） were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species, 14 genera, ...A total of 142 specimens of Ceramiales （Rhodophyta） were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species, 14 genera, and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers, namely, partial large subunit rRNA gene （LSU）, universal plastid amplicon （UPA）, and partial mitochondrial cytochrome c oxidase subunit I gene （COl）. No intraspecific divergence was found in our collection for these markers, except for a 1-3 bp divergence in the COI of Ceramium kondoi, Syrnphyocladia latiuscula, and Neosiphoniajaponica. Because short DNA markers were used, the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in GenBank or BOLD （Barcode of Life Data） Systems. Three specimens were presumed as Heterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification, which was the first record in the investigated area, implying that it might he a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers, Heterosiphonia japonica converged with Dasya spp. and was distant from the other Heterosiphonia spp., implying that H.japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species, but the COI had a higher ability to discriminate between species.展开更多
Objective: To investigate and compare the antileishmanial effects of CAPE and(CAPE)PLGA NPs on Leishmania infantum(L.infantum) promastigotes and amastigotes in vitro,Methods: Efficacies of CAPE,(CAPE)PLGA NPs and free...Objective: To investigate and compare the antileishmanial effects of CAPE and(CAPE)PLGA NPs on Leishmania infantum(L.infantum) promastigotes and amastigotes in vitro,Methods: Efficacies of CAPE,(CAPE)PLGA NPs and free PLGA nanoparticles(NPs) on promastigotes were evaluated using MTT and promastigote count assays,and their anti-amastigote effects were determined via infection index analysis,Griess reaction was also performed to calculate nitric oxide production of macrophages exposed to investigated molecules,Results: It was determined that CAPE and(CAPE)PLGA NPs demonstrated significant inhibitory effects on L.infantum promastigotes and amastigotes,while free NPs did not exhibit any meaningful antileishmanial effectiveness,The IC50 values of CAPE for L.infantum promastigotes and amastigotes were assessed as(51.0±0.8) and(19.0±1.4) μg/m L,respectively(P<0.05),On the other side,it was revealed that(CAPE)PLGA NPs had superior antileishmanial activity on both forms of parasites since its IC50 values for L.infantum promastigotes and amastigotes were(32.0±1.3) and(8.0±0.9) μg/m L,respectively(P<0.05),It was also determined that both agents strongly stimulated nitric oxide production of macrophages,Conclusions: The obtained results show that(CAPE)PLGA NPs have a great potential to be especially used in treatment of visceral leishmaniasis; however,in vivo antileishmanial screening of these molecules should be performed in the near future.展开更多
Objective: To prepare and characterize poly lactic-co-glycolic acid(PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of anti...Objective: To prepare and characterize poly lactic-co-glycolic acid(PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.展开更多
The structure of a binuclear cadmium（Ⅱ） quaternary complex, [Cd2（phen）2- Q2（BP）]n 1 （phen = 1,10-phenanthroline, BP = biphenyl-4,4′-dicarboxylic acid, Q = 8-hydroxy- quinoline-anion）, has been determined by ...The structure of a binuclear cadmium（Ⅱ） quaternary complex, [Cd2（phen）2- Q2（BP）]n 1 （phen = 1,10-phenanthroline, BP = biphenyl-4,4′-dicarboxylic acid, Q = 8-hydroxy- quinoline-anion）, has been determined by X-ray crystallography and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. It crystallizes in the monoclinic system, space group P21/n with a = 13.1906（18）, b = 10.9623（15）, c = 16.947（2）A, β = 111.3430（10）°, V = 2282.5（5）A^3, Z = 4, Mr = 556.85, Dc = 1.620 g/cm^3, F（000） = 1116,μ= 0.994 mm^-1 and S = 1.056. In the structure, 1D chains are connected via biphenyl-4,4′-dicarboxylic acid, 8-hydroxy quinoline anion and binuclear cadmium atoms into an infinite 1-D molecular chain architecture. Via aryl ring π-π stacking interactions a supramolecular structure is formed in 1.展开更多
Surface Electromyography (EMG) is a standard method used in clinical practice and research to assess motor function in order to help with the diagnosis of neuromuscular pathology in human and animal models. EMG record...Surface Electromyography (EMG) is a standard method used in clinical practice and research to assess motor function in order to help with the diagnosis of neuromuscular pathology in human and animal models. EMG recorded from trunk muscles involved in the activity of breathing can be used as a direct measure of respiratory motor function in patients with spinal cord injury (SCI) or other disorders associated with motor control deficits. However, EMG potentials recorded from these muscles are often contaminated with heart-induced electrocardiographic (ECG) signals. Elimination of these artifacts plays a critical role in the precise measure of the respiratory muscle electrical activity. This study was undertaken to find an optimal approach to eliminate the ECG artifacts from EMG recordings. Conventional global filtering can be used to decrease the ECG-induced artifact. However, this method can alter the EMG signal and changes physiologically relevant information. We hypothesize that, unlike global filtering, localized removal of ECG artifacts will not change the original EMG signals. We develop an approach to remove the ECG artifacts without altering the amplitude and frequency components of the EMG signal by using an externally recorded ECG signal as a mask to locate areas of the ECG spikes within EMG data. These segments containing ECG spikes were decomposed into 128 sub-wavelets by a custom-scaled Morlet Wavelet Transform. The ECG-related subwavelets at the ECG spike location were removed and a de-noised EMG signal was reconstructed. Validity of the proposed method was proven using mathematical simulated synthetic signals and EMG obtained from SCI patients. We compare the Rootmean Square Error and the Relative Change in Variance between this method, global, notch and adaptive filters. The results show that the localized wavelet-based filtering has the benefit of not introducing error in the native EMG signal and accurately removing ECG artifacts from EMG signals.展开更多
In order to select an optimum extraction method for the target glycoprotein （TGP） from jellyfish （Rhopilema esculentum） oral-arms, a high performance liquid chromatography （HPLC）-assay for the determination of t...In order to select an optimum extraction method for the target glycoprotein （TGP） from jellyfish （Rhopilema esculentum） oral-arms, a high performance liquid chromatography （HPLC）-assay for the determination of the TGP was developed Purified target glycoprotein was taken as a standard glycoprotein. The results showed that the calibration curves for peak area plotted against concentration for TGP were linear （r= 0.9984, y=4.5895x＋47.601） over concentrations ranging from 50 to 400mgL^-1. The mean extraction recovery was 97.84% （CV2.60%）. The fractions containing TGP were isolated from jellyfish （R esculentum） oral-arms by four extraction methods： 1） water extraction （WE）, 2） phosphate buffer solution （PBS） extraction （PE）, 3） ultrasound-assisted water extraction （UA-WE）, 4） ultrasound-assisted P/3S extraction （UA-PE）. The lyophilized extract was dissolved in Milli-Q water and analyzed directly on a short TSK-GEL G4000PWXL （7.8 mm×300 ram） column. Our results indicated that the UA-PE method was the optimum extraction method selected by HPLC.展开更多
Human dental enamel forms over a period of 2 4 years by substituting the enamel matrix, a protein gel mostly composed of a single protein, amelogenin with fibrous apatite nanocrystals. Self-assembly of a dense ameloge...Human dental enamel forms over a period of 2 4 years by substituting the enamel matrix, a protein gel mostly composed of a single protein, amelogenin with fibrous apatite nanocrystals. Self-assembly of a dense amelogenin matrix is presumed to direct the growth of apatite fibers and their organization into bundles that eventually comprise the mature enamel, the hardest tissue in the mammalian body. This work aims to establish the physicochemical and biochemical conditions for the synthesis of fibrous apatite crystals under the control of a recombinant full-length human amelogenin rnatrix in combination with a pro- grammable titration system. The growth of apatite substrates was initiated from supersaturated calcium phosphate solutions in the presence of dispersed amelogenin assemblies. It was shown earlier and confirmed in this study that binding of amelogenin onto apatite surfaces presents the first step that leads to substrate-specific crystal growth. In this work, we report enhanced nucleation and growth under conditions at which amelogenin and apatite carry opposite charges and adsorption of the protein onto the apatite seeds is even more favored. Experiments at pH below the isoelectric point of amelogenin showed increased protein binding to apatite and at low Ca/P molar ratios resulted in a change in crystal morphology from plate-like to fibrous and rod-shaped. Concentrations of calcium and phosphate ions in the supernatant did not show drastic decreases throughout the titration period, indicating controlled precipitation from the protein suspension metastable with respect to calcium phosphate. It is argued that amelobtasts in the developing enamel may vary the density of the protein matrix at the nano scale by varying local pH, and thus control the interaction between the mineral and protein phases. The biomimetic experimental setting applied in this study has thus proven as convenient for gaining insight into the fundamental nature of the process ofamelogenesis.展开更多
Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a speci...Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5′-phosphated RT primer and two pairs of specific inverse PCR primers. Compared with the anchored PCR RACE, inverse PCR RACE has better specificity and higher amplification.展开更多
基金supported in part by NIH grants R01NS39600,U01MH114829RF1MH128693(to GAA)。
文摘Many fields,such as neuroscience,are experiencing the vast prolife ration of cellular data,underscoring the need fo r organizing and interpreting large datasets.A popular approach partitions data into manageable subsets via hierarchical clustering,but objective methods to determine the appropriate classification granularity are missing.We recently introduced a technique to systematically identify when to stop subdividing clusters based on the fundamental principle that cells must differ more between than within clusters.Here we present the corresponding protocol to classify cellular datasets by combining datadriven unsupervised hierarchical clustering with statistical testing.These general-purpose functions are applicable to any cellular dataset that can be organized as two-dimensional matrices of numerical values,including molecula r,physiological,and anatomical datasets.We demonstrate the protocol using cellular data from the Janelia MouseLight project to chara cterize morphological aspects of neurons.
基金Project supported by the National Natural Science Foundation of China(No.20447001, 40476049)the Natural Science Foundation of Fujian Province of China(No. D0410007).
文摘It has been reported that there is an interaction between Benzo[a]pyrene （BaP）, a widespread carcinogenic polycyclic aromatic hydrocarbon, and tributyltin （TBT）, an organometal used as an antifouling biocide. This study was therefore designed to examine the potential in vivo influence of BaP, TBT and their mixture on splenic antioxidant defense systems of Sebastiscus marmoratus. The fish were exposed to water containing environmentally relevant concentrations of BaP, TBT and their mixture. Spleens were collected for biochemical analysis after exposure for 7, 25, 50 d and after recovery for 7, 20 d. Cotreatment with BaP and TBT for 7 d potentiated the induction of glutathione peroxidase （GPx） activity by BaP or TBT alone. The cotreatment for 25 and 50 d resulted in inhibition of GPx activity, which was similar to the effect of TBT. Splenic glutathione S-transferase （GST） activities were significantly elevated in S. marmoratus exposed to BaP starting from 7 d and remained high up to 25 d. However, no further activity change was found with prolonged exposure. Cotreatment of BaP and TBT primarily inhibited the GST activity, which was similar to the effect of TBT. Cotreatment with BaP and TBT for 25 or 50 d potentiated the depletion of GSH （glutathione） by BaP or TBT alone. MDA （malondialdehyde） contents in spleen of S. marmoratus were not significantly altered compared with the control during the test period. Spleen, as an immune organ, is sensitive to exposure of BaP or TBT. It should have an effective mechanism to counteract oxidative damage. Antioxidative defense systems in spleen of S. marmoratus should be considered as potential biomarkers. Short-term exposure of BaP or TBT could result in induction of antioxidant defense system. A significant decrease of these indices, such as GSH, GST, GPx might indicate more severe contamination.
文摘AIM： To investigate the effect of a Chinese medicine, Kaiyu Qingwei Jianji （KYQWJJ） used for diabetic treatment, on the morphometry and residual strain distribution of the small intestine in streptozotocin （STZ） -induced diabetic rats. Correlation analysis was also performed between the opening angle and residual strain with the blood glucose level. METHODS： Forty-two male Wistar rats weighing 220-240 g were included in this study. Thirty-two STZ- induced diabetic rats were subdivided into four groups （n = 8 in each group）, i.e. diabetic control group （DM）; high dose of KYQWJJ （T1, 36g/kg per day）; low dose of KYQWJJ （T2, 17 g/kg per day） and Gliclazide （T3, 50 mg/kg per day）. Another ten rats were used as nondiabetic control （CON）. The medicines were poured directly into stomach lumen by gastric lavage twice daily. The rats of CON and DM groups were only poured the physiological saline. Blood glucose and plasma insulin levels were measured. Experimental period was 35 d. At the end of experiment, three 5-cm long segments were harvested from the duodenum, jejunum and ileum. Three rings of 1-2 mm in length for no-load and zero-stress state tests were cut from the middle of different segments. The morphometric data, such as the circumferential length, the wall thickness and the opening angle were measured from the digitized images of intestinal segments in the no-load state and zerostress state. The residual strain was computed from the morphometry data. Furthermore, the linear regression analysis was performed between blood glucose level with morphometric and biomechanical data in the different intestinal segments. RESULTS： The blood glucose level of DM group was consistent 4-fold to 5-fold higher than those in CON group during the experiment （16.89 ± 1.11 vs 3.44 ± 0.15 mmol/L, P 〈 0.001）. The blood glucose level in the T1 （16.89 ± 1.11 vs 11.08 ± 2.67 mmol/L, P 〈 0.01） and T3 groups （16.89 ± 1.11 vs 13.54 ± 1.73 mmol/L, P 〈 0.05）, but not in T2 group （P 〉 0.05） was significantly lower than those in DM group. The plasma insulin levels of DM, T1, T2 and T3 groups were significantly lower than those in CON group （10.98 ± 1.02, 12.52 ± 1.42,13.54 ± 1.56,10.96 ± 0.96 vs 17.84 ± 2.34 pmol/L respectively, P 〈 0.05）, but no significantly difference among the groups with exception of CON group. The wet weight/cm and total wall thickness of duodenum, jejunum and ileum in DM group were significantly higher than those in CON group （wet weight （g/cm）： duodenum 0.209 ± 0.012 vs 0.166 ± 0.010, jejunum 0.149 ± 0.008 vs 0.121 ± 0.004, ileum 0.134 ± 0.013 vs 0.112 ± 0.007; Wall thickness （mm）： duodenum 0.849 ± 0.027 vs 0.710 ± 0.026, jejunum 0.7259 ± 0.034 vs 0.627 ± 0.025, ileum 0.532 ± 0.023 vs 0.470 ± 0.010, all P 〈 0.05）, T1 and T3 treatment could partly restore change of wall thickness, but T2 could not. The opening angle and absolute value of inner and outer residual stain were significantly smaller in duodenal segment （188 ± 11 degrees, -0.31 ± 0.02 and 0.35 ± 0.03 vs 259 ± 15 degrees, -0.40 ± 0.02 and 0.43 ± 0.05） and larger in jejunal （215 ± 20 degrees, -0.30 ± 0.03 and 0.36 ± 0.06 vs 172 ± 19 degrees, -0.25 ± 0.02 and 0.27 ± 0.02） and ileal segments （183 ± 20 degrees, -0.28 ± 0.01 and 0.34 ± 0.05 vs 153 ± 14 degrees, -0.23 ± 0.03 and 0.29 ± 0.04） in DM group than in CON group （P 〈 0.01）. TI and T3 treatment could partly restore this biomechanical alteration, but strong effect was found in T1 treatment （duodenum 243 ± 14 degrees, -0.36 ± 0.02 and 0.42 ± 0.06, jejunum 180 ± 15 degrees, -0.26 ± 0.03 and 0.30 ± 0.06 and ileum 163 ± 17 degrees, -0.23 ± 0.03 and 0.30 ± 0.05, compared with DM, P 〈 0.05）. The linear association was found between the glucose level with most morphometric and biomechanical data. CONCLUSION： KYQWJJ （high dose） treatment could partly restore the changes of blood glucose level and the remodeling of morphometry and residual strain of small intestine in diabetic rats. The linear regression analysis demonstrated that the effect of KYQWJJ on intestinal opening angle and residual strain is partially through its effect on the blood glucose level.
基金Supported by the National High Technology Research and Development Program of China (2006AA020101, 2007AA10Z360,2009AA03Z232)Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period (2008BA163B07)
文摘The non-edible crude rice bran oil was extracted from white rice bran, and then was catalyzed by immobilized lipase for biodiesel production in this study. The effects of water content, oil/methanol molar ratio, temperature, enzyme amount, solvent,number of methanol added times and two-step methanolysis by using Candida sp. 99-125 as catalyst were investigated. The optimal conditions for processing 1 g rice bran oil were: 0.2 g immobilized lipase, 2 ml n-hexane as solvent, 20% water based on the rice bran oil mass, temperature of 40 °C and two-step addition of methanol. As a result, the fatty acid methyl esters yield was 87.4%. The immobilized lipase was proved to be stable when it was used repeatedly for 7 cycles.
文摘The antimicrobial and antioxidant effects of two spice extracts and their combination on raw chicken meat during storage for 15 days at 4◦C were studied.Raw chicken meat was treated with BHT(positive control),rosemary(RO),cloves(CL),and their combination,and the results were compared to those obtained for raw chicken meat without any additive(negative control).The antioxidant and antimicrobial activities of spice extracts were determined.The total phenolic and total flavonoid contents of rosemary was lower than those of cloves.Cloves exhibited a higher DPPH radical scavenging activity than that of rosemary.However,the ferrous ion-chelating effect of rosemary was significantly higher than that of cloves.The pH,instrumental colour(CIE L*,a*,b*),total viable counts(TVC),lactic acid bacteria(LAB)counts,Enterobacteriaceae counts,Pseudomonas spp.counts and 2-thiobarbituric acid reactive substances(TBARS)were determined at 3-day intervals over a period of 15 days.The bacterial counts of T-RO-CL samples were lower than those of control samples during storage.T-RO-CL samples maintained significantly(P<0.05)higher L*,a*and b*values during storage.The TBARS values of T-RO-CL samples were the lowest among the samples.These results demonstrate that spice extracts are highly effective against microbial growth and lipid oxidation and show potential as a natural antioxidant in raw chicken meats.
基金support from a bridge grant from the Temple Office of the Vice President for Research(OVPR).
文摘The demand for biomaterials that promote the repair,replacement,or restoration of hard and soft tissues continues to grow as the population ages.Traditionally,smart biomaterials have been thought as those that respond to stimuli.However,the continuous evolution of the field warrants a fresh look at the concept of smartness of biomaterials.This review presents a redefinition of the term“Smart Biomaterial”and discusses recent advances in and applications of smart biomaterials for hard tissue restoration and regeneration.To clarify the use of the term“smart biomaterials”,we propose four degrees of smartness according to the level of interaction of the biomaterials with the bio-environment and the biological/cellular responses they elicit,defining these materials as inert,active,responsive,and autonomous.Then,we present an up-to-date survey of applications of smart biomaterials for hard tissues,based on the materials’responses(external and internal stimuli)and their use as immune-modulatory biomaterials.Finally,we discuss the limitations and obstacles to the translation from basic research(bench)to clinical utilization that is required for the development of clinically relevant applications of these technologies.
基金the National Key Technologies R & D Program of China during the 10th Five-Year Plan(No.2001BA302B)
文摘As a new mutagenetic method, low-energy ion implantation has been used widely in many research areas in recent years. In order to obtain some industrial strains with high xylanase yield, the wild type strain Aspergillus niger A3 was mutated by means of nitrogen ions implantation （10 keV, 2.6× 10^14 ～ 1.56 × 10^15 ions/cm^2） and a mutant N212 was isolated subsequently. However, it was found that the initial screening means of the high-yielding xylanase strains such as transparent halos was unfit for first screening. Compared with that of the wild type strain, xylanase production of the mutant N212 was increased from 320 IU/ml to 610 IU/ml, and the optimum fermentation temperature was increased from 28 ℃ to 30 ℃.
基金Project supported by the National High-Tech R&D Program(863)of China(No.2007AA09Z449)
文摘The unicellular green alga Dunaliella salina is well adapted to salt stress and contains compounds（including β-carotene and vitamins） with potential commercial value.A large transcriptome database of D.salina during the adjustment, exponential and stationary growth phases was generated using a high throughput sequencing platform.We characterized the metabolic processes in D.salina with a focus on valuable metabolites, with the aim of manipulating D.salina to achieve greater economic value in large-scale production through a bioengineering strategy.Gene expression profiles under salt stress verified using quantitative polymerase chain reaction（qPCR） implied that salt can regulate the expression of key genes.This study generated a substantial fraction of D.salina transcriptional sequences for the entire growth cycle, providing a basis for the discovery of novel genes.This first full-scale transcriptome study of D.salina establishes a foundation for further comparative genomic studies.
基金supported by the National Natural Science Foundation of China(No.21273101 and 21302082)the Foundation of the Program for Backbone Teachers in Universities of Henan Province(No.2012GGJS158)
文摘Hydrothermal reactions of biphenyl-2,3,3A,5A-tetracarboxylic acid（H4bptc） with cobalt salt in the presence of 1,4-bis（2-pyridylmethyl）piperazin（bpmp） afforded one novel coordination polymer, namely, [Co（H2bptc）（bpmp）0.5（H2O）]n（1）. Its structure was established by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra and TG analysis. Complex 1 crystallizes in monoclinic, space group P21/c with a = 11.4839（11）, b = 16.6690（16）, c = 11.5559（11） A, V = 2201.8（4） A3, Mr = 539.35, Dc = 1.627 g/cm^3, μ（MoK α） = 0.841 mm-1, F（000） = 1108, Z = 4, the final R = 0.0309 and w R = 0.0705 for 4090 observed reflections（I 2σ（I））. Complex 1 displays a one-dimensional（1D） chain bridged by bpmp. Two carboxylic groups of H4 bptc ligand adopt μ01-η1：η1 and μ1-η1：η coordination modes to bridge adjacent Co（Ⅱ） ions together with bpmp ligand to give alternately arranged left- and right-handed helical chains. In addition, variable-temperature magnetic susceptibility measurements indicate that complex 1 shows weak antiferromagnetic interactions between the adjacent Co（Ⅱ） ions.
基金supported by the Public Science and Technology Research Funds Projects of Ocean(201105021 and 201305030)National Natural Science Foundation China(41276137)+1 种基金Shandong Provincial Natural Science Foundation,China(ZR2011CM 018)Qingdao Municipal Science and Technology Program,China(09-2-5-3-hy)
文摘An assessment with assistance of DNA barcoding was conducted on green macroalgae in coastal zone around Qingdao, China, during the period of April- December, 2011. Three markers were applied in molecular discrimination, including the plastid elongation factor tufA gene, the internal transcribed spacer(ITS) region of the ribosomal cistron and rubisco large subunit gene 3' regions(rbcL-3P). DNA barcoding discriminated 8 species, excluding species of genus Cladophora and Bryopsis due to failures in amplification. We ascertained and corrected 4 species identified by morphological methods for effectively assisting the classification. The gene tufA presented more advantages as an appropriate DNA marker with the strongest amplification success rate and species discrimination power than the other two genes. The poorest sequencing success largely handicapped the application of ITS. Samples identified by tufA and rbcL as Ulva flexuosa were clustered into the clade of U. prolifera by ITS in the neighbor-joining tree. Confusion with discrimination of the complex of U. linza, U. procera and U. prolifera(as the LPP complex) still existed for the three DNA markers. Based on our results, rbcL is recommended as a preferred marker for assisting tufA to discriminate green macroalgae. In distinguishing green-tide-forming Ulva species, the free-floating sample collected from the green tide in 2011 was proved to be identical with U. prolifera in Yellow Sea for ITS and rbcL genes. This study presents a preliminary survey of green macroalgae distributed in the coastal area around Qingdao, and proves that DNA barcoding is a powerful tool for taxonomy of green macroalgae.
文摘This paper reviews some of the nanoindentation research that has been done on teeth and discusses the usefulness of this technique in studying the structure-property-function relationship at the micro and nanometer scale. In particular, examples on the use of nanoindentation technique in investigating the effects of cleansing and bleaching agents as well as drinks on the micro- and nanostructures and mechanical properties of teeth are highlighted. Although nanoindentation on teeth is a relatively new area of research, it provides an excellent way of probing and relating the structures and mechanical properties of teeth at the submicron and nanometer scales that were previously not possible but which can now greatly benefit dental research. For example, a nanoindenter with a high resolution imaging capability can help to elucidate the mechanisms with which certain diseases can damage and compromise the structural integrity of teeth at the micro- and nanometer scale. With this information, clinicians and researchers can then work towards how best to tackle these problems or even preventing them.
文摘Extracellular polysaccharide from Tremella aurantialba (TEP) significantly inhibited H2O2-induced haemolysis of RBCs, significantly decreased the amount of malondialdehyde (MDA) produced in mice liver homogenates as a result of autoxidation, and inhibited VitC-Fe2+-induced swelling of liver mitochondria.
基金Supported by the Public Science and Technology Research Funds Projects of Ocean(Nos.201105021,201305030)the National Natural Science Foundation of China(No.41276137)
文摘A total of 142 specimens of Ceramiales （Rhodophyta） were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species, 14 genera, and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers, namely, partial large subunit rRNA gene （LSU）, universal plastid amplicon （UPA）, and partial mitochondrial cytochrome c oxidase subunit I gene （COl）. No intraspecific divergence was found in our collection for these markers, except for a 1-3 bp divergence in the COI of Ceramium kondoi, Syrnphyocladia latiuscula, and Neosiphoniajaponica. Because short DNA markers were used, the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in GenBank or BOLD （Barcode of Life Data） Systems. Three specimens were presumed as Heterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification, which was the first record in the investigated area, implying that it might he a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers, Heterosiphonia japonica converged with Dasya spp. and was distant from the other Heterosiphonia spp., implying that H.japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species, but the COI had a higher ability to discriminate between species.
基金supported by Yildiz Technical University Scientific Research Projects Coordination Department with Project NO.2014-07-04-GEP02
文摘Objective: To investigate and compare the antileishmanial effects of CAPE and(CAPE)PLGA NPs on Leishmania infantum(L.infantum) promastigotes and amastigotes in vitro,Methods: Efficacies of CAPE,(CAPE)PLGA NPs and free PLGA nanoparticles(NPs) on promastigotes were evaluated using MTT and promastigote count assays,and their anti-amastigote effects were determined via infection index analysis,Griess reaction was also performed to calculate nitric oxide production of macrophages exposed to investigated molecules,Results: It was determined that CAPE and(CAPE)PLGA NPs demonstrated significant inhibitory effects on L.infantum promastigotes and amastigotes,while free NPs did not exhibit any meaningful antileishmanial effectiveness,The IC50 values of CAPE for L.infantum promastigotes and amastigotes were assessed as(51.0±0.8) and(19.0±1.4) μg/m L,respectively(P<0.05),On the other side,it was revealed that(CAPE)PLGA NPs had superior antileishmanial activity on both forms of parasites since its IC50 values for L.infantum promastigotes and amastigotes were(32.0±1.3) and(8.0±0.9) μg/m L,respectively(P<0.05),It was also determined that both agents strongly stimulated nitric oxide production of macrophages,Conclusions: The obtained results show that(CAPE)PLGA NPs have a great potential to be especially used in treatment of visceral leishmaniasis; however,in vivo antileishmanial screening of these molecules should be performed in the near future.
基金supported by Scientific and Technological Research Council of Turkey(TUBITAK,Grant No.213S148)
文摘Objective: To prepare and characterize poly lactic-co-glycolic acid(PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.
基金Siping Sci-tech Development Planning Project(No.2005012)
文摘The structure of a binuclear cadmium（Ⅱ） quaternary complex, [Cd2（phen）2- Q2（BP）]n 1 （phen = 1,10-phenanthroline, BP = biphenyl-4,4′-dicarboxylic acid, Q = 8-hydroxy- quinoline-anion）, has been determined by X-ray crystallography and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. It crystallizes in the monoclinic system, space group P21/n with a = 13.1906（18）, b = 10.9623（15）, c = 16.947（2）A, β = 111.3430（10）°, V = 2282.5（5）A^3, Z = 4, Mr = 556.85, Dc = 1.620 g/cm^3, F（000） = 1116,μ= 0.994 mm^-1 and S = 1.056. In the structure, 1D chains are connected via biphenyl-4,4′-dicarboxylic acid, 8-hydroxy quinoline anion and binuclear cadmium atoms into an infinite 1-D molecular chain architecture. Via aryl ring π-π stacking interactions a supramolecular structure is formed in 1.
文摘Surface Electromyography (EMG) is a standard method used in clinical practice and research to assess motor function in order to help with the diagnosis of neuromuscular pathology in human and animal models. EMG recorded from trunk muscles involved in the activity of breathing can be used as a direct measure of respiratory motor function in patients with spinal cord injury (SCI) or other disorders associated with motor control deficits. However, EMG potentials recorded from these muscles are often contaminated with heart-induced electrocardiographic (ECG) signals. Elimination of these artifacts plays a critical role in the precise measure of the respiratory muscle electrical activity. This study was undertaken to find an optimal approach to eliminate the ECG artifacts from EMG recordings. Conventional global filtering can be used to decrease the ECG-induced artifact. However, this method can alter the EMG signal and changes physiologically relevant information. We hypothesize that, unlike global filtering, localized removal of ECG artifacts will not change the original EMG signals. We develop an approach to remove the ECG artifacts without altering the amplitude and frequency components of the EMG signal by using an externally recorded ECG signal as a mask to locate areas of the ECG spikes within EMG data. These segments containing ECG spikes were decomposed into 128 sub-wavelets by a custom-scaled Morlet Wavelet Transform. The ECG-related subwavelets at the ECG spike location were removed and a de-noised EMG signal was reconstructed. Validity of the proposed method was proven using mathematical simulated synthetic signals and EMG obtained from SCI patients. We compare the Rootmean Square Error and the Relative Change in Variance between this method, global, notch and adaptive filters. The results show that the localized wavelet-based filtering has the benefit of not introducing error in the native EMG signal and accurately removing ECG artifacts from EMG signals.
基金support from the National High Technology Research and Development Program of China (No.2006AA09Z438)
文摘In order to select an optimum extraction method for the target glycoprotein （TGP） from jellyfish （Rhopilema esculentum） oral-arms, a high performance liquid chromatography （HPLC）-assay for the determination of the TGP was developed Purified target glycoprotein was taken as a standard glycoprotein. The results showed that the calibration curves for peak area plotted against concentration for TGP were linear （r= 0.9984, y=4.5895x＋47.601） over concentrations ranging from 50 to 400mgL^-1. The mean extraction recovery was 97.84% （CV2.60%）. The fractions containing TGP were isolated from jellyfish （R esculentum） oral-arms by four extraction methods： 1） water extraction （WE）, 2） phosphate buffer solution （PBS） extraction （PE）, 3） ultrasound-assisted water extraction （UA-WE）, 4） ultrasound-assisted P/3S extraction （UA-PE）. The lyophilized extract was dissolved in Milli-Q water and analyzed directly on a short TSK-GEL G4000PWXL （7.8 mm×300 ram） column. Our results indicated that the UA-PE method was the optimum extraction method selected by HPLC.
文摘Human dental enamel forms over a period of 2 4 years by substituting the enamel matrix, a protein gel mostly composed of a single protein, amelogenin with fibrous apatite nanocrystals. Self-assembly of a dense amelogenin matrix is presumed to direct the growth of apatite fibers and their organization into bundles that eventually comprise the mature enamel, the hardest tissue in the mammalian body. This work aims to establish the physicochemical and biochemical conditions for the synthesis of fibrous apatite crystals under the control of a recombinant full-length human amelogenin rnatrix in combination with a pro- grammable titration system. The growth of apatite substrates was initiated from supersaturated calcium phosphate solutions in the presence of dispersed amelogenin assemblies. It was shown earlier and confirmed in this study that binding of amelogenin onto apatite surfaces presents the first step that leads to substrate-specific crystal growth. In this work, we report enhanced nucleation and growth under conditions at which amelogenin and apatite carry opposite charges and adsorption of the protein onto the apatite seeds is even more favored. Experiments at pH below the isoelectric point of amelogenin showed increased protein binding to apatite and at low Ca/P molar ratios resulted in a change in crystal morphology from plate-like to fibrous and rod-shaped. Concentrations of calcium and phosphate ions in the supernatant did not show drastic decreases throughout the titration period, indicating controlled precipitation from the protein suspension metastable with respect to calcium phosphate. It is argued that amelobtasts in the developing enamel may vary the density of the protein matrix at the nano scale by varying local pH, and thus control the interaction between the mineral and protein phases. The biomimetic experimental setting applied in this study has thus proven as convenient for gaining insight into the fundamental nature of the process ofamelogenesis.
文摘Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5′-phosphated RT primer and two pairs of specific inverse PCR primers. Compared with the anchored PCR RACE, inverse PCR RACE has better specificity and higher amplification.
