Arrays of noble metal nanoparticles show potential applications in (bio-)sensing, optical storage, surface-enhanced spectroscopy, and waveguides. For all such potential devices, controlling the size, morphology, and...Arrays of noble metal nanoparticles show potential applications in (bio-)sensing, optical storage, surface-enhanced spectroscopy, and waveguides. For all such potential devices, controlling the size, morphology, and interparticle spacing of the nanoparticles is very important. Here, we combine seed-mediated growth with nanosphere lithography to study the controllable growth of gold nanoparticles (Au NPs), in which the self-assembly monolayer of polystyrene (PS) on a silicon surface is used to guide the modification of allaunesilanes and the subsequent adsorption of gold seeds; seed-mediated growth is applied to controlling the morphology and size of Au NPs. The size of adsorption region (determining the number of adsorbed gold seeds) is controlled by etching PS microspheres with oxygen plasma or annealing PS microspheres at the glass transition temperature. The size and morphology of the Au NPs are controlled by changing growth conditions. In such a way, we have achieved the dual control of the obtained Au NPs. Preliminary results show that this strategy holds a great promise. This approach can also be extended to a wide range of materials and substrates.展开更多
Adventures of Huckleberry Finn is one of the masterpieces of American novelist Mark Twain. In this novel, Twain not onlydescribes the courageous adventures of Huck, but also his psychological or spiritual growth. Due ...Adventures of Huckleberry Finn is one of the masterpieces of American novelist Mark Twain. In this novel, Twain not onlydescribes the courageous adventures of Huck, but also his psychological or spiritual growth. Due to the social and cultural back-ground of that time and general cultural concept the protagonist was instilled before, the conflicts of the protagonist's self-con-sciousness appear many times in this novel when the issue of slavery is concerned. However, through the protagonist's inner con-flicts, he finally gains spiritual growth and obtains a higher level of moral maturity.展开更多
Objective Acute myeloid leukemia(AML)is an aggressive hematological malignancy characterized by abnormal myeloid blast expansion.Recent studies have demonstrated that circular RNAs play a role in AML pathogenesis.In t...Objective Acute myeloid leukemia(AML)is an aggressive hematological malignancy characterized by abnormal myeloid blast expansion.Recent studies have demonstrated that circular RNAs play a role in AML pathogenesis.In this study,we aimed to investigate the clinical significance of circ_0012152 in AML and elucidate its underlying molecular mechanism in the pathogenesis of this condition.Methods Circ_0012152 expression was detected by quantitative real-time polymerase chain reaction in samples obtained from 247 patients with AML and 40 healthy controls.A systematic analysis of clinical characteristics and prognostic factors was also conducted.Cell growth was assessed using the Cell Counting Kit-8(CCK-8)assay,and apoptosis and cell cycle progression were evaluated by flow cytometry.Moreover,RNA pull-down was performed to identify target microRNAs,and transcriptome RNA sequencing and bioinformatics analyses were utilized to identify downstream mRNA targets.Results Circ_0012152 was significantly upregulated in samples from patients with AML and served as an independent adverse prognostic factor for overall survival(OS)(hazard ratio:2.357;95%confidence interval 1.258–4.415).The circ_0012152 knockdown reduced cell growth,increased apoptosis,and inhibited cell cycle progression in AML cell lines.RNA pull-down and sequencing identified miR-652-3p as a target microRNA of circ_0012152.Cell growth inhibition by circ_0012152 knockdown was significantly relieved by miR-652-3p inhibitors.We suggested that miR-652-3p targeted SOX4,as the decrease in SOX4 expression resulting from circ_0012152 knockdown was upregulated by miR-652-3p inhibitors in AML cells.Conclusion Circ_0012152 is an independent poor prognostic factor for OS in AML,and it promotes AML cell growth by upregulating SOX4 through miR-652-3p.展开更多
Long(15-40 μm), thin(diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To ...Long(15-40 μm), thin(diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To investigate the growth mechanism, we examined the microstructure of these CuNWs at different reaction time. It was found that the CuNWs were actually formed through the self-assembling of Cu nanoparticles along the [110] direction. The transparent electrodes fabricated using the CuNWs achieved a high transparency of 76 % at 31±5 Ω/□.展开更多
Quantum dot lasers have excellent characteristics such as temperature stability of threshold current and ultra-high material gain. Quantum dot structures fabricated by self-organized growth have high crystalline perfe...Quantum dot lasers have excellent characteristics such as temperature stability of threshold current and ultra-high material gain. Quantum dot structures fabricated by self-organized growth have high crystalline perfection, high quantum yield of radiative recombination and high size homogeneity. Main advantages and operating properties of quantum dot lasers fabricated by self-organized growth are briefly introduced.展开更多
Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis m...Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.展开更多
In the rapid development of technology and knowledge-based economy against the background of the times, the IPR of enterprises participating in the process of value creation has been the key issues in the business wor...In the rapid development of technology and knowledge-based economy against the background of the times, the IPR of enterprises participating in the process of value creation has been the key issues in the business world. The resulting growth in the value chain of IP is a complicated process of evolution, and non-linear dynamics, and self-organizing system. This paper explores the intellectual property value chain from its conditions, mechanisms and dynamics as well as the inspiration for the enterprises.展开更多
The role of self assembled monolayer in inducing the crystal growth was investigated by X ray diffractions (XRD), and scanning electron microscopy (SEM). Results show that crystallization in the absence of monolayer r...The role of self assembled monolayer in inducing the crystal growth was investigated by X ray diffractions (XRD), and scanning electron microscopy (SEM). Results show that crystallization in the absence of monolayer results in a mixture of poorly crystallized calcium phosphates, including hydroxyapatite (HAP) and octacalcium phosphate (OCP), while the presence of self assembled monolayer gives rise to oriented and well crystallized HAP crystals. Moreover, the HAP crystal grows very quickly under the self assembled monolayer, whereas very little calcium phosphate crystals grow without the monolayer. It is rationalized that the hexadecylamine monolayer with high polarity and charged density leads to increase supersaturation and lower the interfacial energy, which attributes to the HAP crystals nucleation. On the other hand, the positive headgroups construct the ordered "recognized site" with distinct size and topology, which results in the oriented HAP crystals deposit.展开更多
It is widely known that hypoxia can promote chondrogenesis of human bone marrow de- rived mesenchymal stem cells (hMSCs) in monolayer cultures. However, the direct impact of oxygen tension on hMSC differentiation in...It is widely known that hypoxia can promote chondrogenesis of human bone marrow de- rived mesenchymal stem cells (hMSCs) in monolayer cultures. However, the direct impact of oxygen tension on hMSC differentiation in three-dimensional cultures is still unknown. This research was de- signed to observe the direct impact of oxygen tension on the ability of hMSCs to "self assemble" into tissue-engineered cartilage constructs, hMSCs were cultured in chondrogenic medium (CM) containing 100 ng/mL growth differentiation factor 5 (GDF-5) at 5% (hypoxia) and 21% (normoxia) 02 levels in monolayer cultures for 3 weeks. After differentiation, the cells were digested and employed in a self- assembly process to produce tissue-engineered constructs under hypoxic and normoxic conditions in vi- tro. The aggrecan and type ]I collagen expression, and type X collagen in the self-assembled con- structs were assessed by using immunofluorescent and immunochemical staining respectively. The methods of dimethylmethylene blue (DMMB), hydroxyproline and PicoGreen were used to measure the total collagen content, glycosaminoglycan (GAG) content and the number of viable cells in each con- struct, respectively. The expression of type II collagen and aggrecan under hypoxic conditions was in- creased significantly as compared with that under normoxic conditions. In contrast, type X collagen expression was down-regulated in the hypoxic group. Moreover, the constructs in hypoxic group showed more significantly increased total collagen and GAG than in normoxic group, which were more close to those of the natural cartilage. These findings demonstrated that hypoxia enhanced chondro- genesis of in vitro, scaffold-free, tissue-engineered constructs generated using hMSCs induced by GDF-5. In hypoxic environments, the self-assembled constructs have a Thistological appearance and biochemical parameters similar to those of the natural cartilage.展开更多
A method of continuous-discontinuous cellular automaton for modeling the growth and coalescence of multiple cracks in brittle material is presented. The method uses the level set to track arbitrary discontinuities, an...A method of continuous-discontinuous cellular automaton for modeling the growth and coalescence of multiple cracks in brittle material is presented. The method uses the level set to track arbitrary discontinuities, and calculation grids are independent of the discontinuities and no remeshing are required with the crack growing. Based on Grif- fith fracture theory and Mohr-Coulumb criterion, a mixed fracture criterion for multiple cracks growth in brittle mate- rial is proposed. The method treats the junction and coales- cence of multiple cracks, and junction criterion and coales- cence criterion for brittle material are given, too. Besides, in order to overcome the tracking error in the level set ap- proximation for crack junction and coalescence, a dichotomy searching algorithm is proposed. Introduced the above the- ories into continuous-discontinuous cellular automaton, the present method can be applied to solving multiple crack growth in brittle material, and only cell stiffness is needed and no assembled global stiffness is needed. Some numerical examples are given to shown that the present method is efficient and accurate for crack junction, coalescence and percolation problems.展开更多
Self-feeding device is extensively used in aquaculture farms, but for salmonids the individual feeding behavior has seldom been continuously observed. In this article, the individual self-feeding behavior of 10 rainbo...Self-feeding device is extensively used in aquaculture farms, but for salmonids the individual feeding behavior has seldom been continuously observed. In this article, the individual self-feeding behavior of 10 rainbow trout was continuously monitored with a PIT tag record for 50 days with three replicates. The?sh fell into three categories according to their feeding behavior, i.e. high triggering ?sh(trigger behavior more than 25% of the group, HT), low triggering ?sh(1%–25%, LT) and zero triggering ?sh(less than1%). The results showed that in a group of 10 individual 1–2 HT ?sh accounted for most of the self-feeding behavior(78.19%–89.14%), which was far more than they could consume. The trigger frequency of the?sh was signi?cantly correlated with the initial body weight( P <0.01), however, no signi?cant dif ference in growth rate among the HT, LT, and ZT ?sh was observed( P >0.05). Cosinor analysis showed that the two HT ?sh in the same group had similar acrophase. Though some of the HT ?sh could be active for 50 d, there were also HT ?sh decreased triggering behavior around 40 d and the high trigger status was then replaced by other ?sh, which was ?rst discovered in salimonds. Interestingly, the growth of the group was not af fected by the alternation triggering ?sh. These results provide evidence that in the self-feeding system the HT ?sh didn't gain much advantage by their frequent self-feeding behavior, and high trigger status of the HT ?sh is not only an individual character but also driven by the demand of the group. In the self-feeding system, the critical individual should be closely monitored.展开更多
A novel cast processing method,self-inoculation method (SIM),was proposed.The process involves the addition of self-inoculant to melt,then pouring the melt to a mould through a multi-stream mixing cooling channel.In t...A novel cast processing method,self-inoculation method (SIM),was proposed.The process involves the addition of self-inoculant to melt,then pouring the melt to a mould through a multi-stream mixing cooling channel.In this paper,the process parameters were investigated.Results indicate that the melt treatment temperature,the amount of self-inoculant added,and the slope angle of the cooling channel are the key factors for SIM process.The optimized parameters are that the melt treatment temperature is between 680 and 700°C;the addition of self-inoculant is between 5wt.% and 7wt.%;and the slope angle of the cooling channel is between 30° and 45°.Further analysis reveals that SIM changes the solidification microstructure of slurry by controlling the nucleation and growth of the primary phase in the melt.展开更多
The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells (PSCs) into chondrocytes was studied. KLD-12 was synthesized by so...The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells (PSCs) into chondrocytes was studied. KLD-12 was synthesized by solid-state method. After TGF-β3 plasmid was loaded into KLD-12 self-assembling peptide nanofiber scaffold, DNA release ability was investigated. PSCs and hTGF-β3 gene were loaded into KLD-12 3-D scaffold, and MTT assay was performed to investigate the cell proliferation, and ELASA assay was used to investigate the expression of TGF-β3. Specific cartilage matrix was examined by quantitative real-time PCR, immunohistochemistry and Alcian Blue staining. Compared with control group, DNA synthesis level of PSCs reached the peak within 3 days when PSCs were cultured in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, and maintained this high level within 2 weeks. MTT results showed that the proliferation ability of experimental group was statistically higher than that in control group (P〈0.05). Quantitative real-time PCR suggested that the percentage of TGF-β3 positive PSCs in experimental group was higher than that in control group (P〈0.01). ELISA assay showed that the TGF-β3 protein level increased in supernatant of experimental group's PSCs, reached the peak after 72 h and then declined a little to the plateau phase. Compared with the control group, the specific gene of chondrocyte typical extracellular matrix significantly up-regulated (P〈0.01). The results showed that PSCs differentiated into chondrocytes in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, which provided a fresh approach to cartilage tissue engineering.展开更多
In this work,we carried out three-dimensional(3D)atomic-scale study on the growth characteristics of{10-12}twin in magnesium(Mg).The study was performed by MD simulations on Mg single crystals with an initial twin nuc...In this work,we carried out three-dimensional(3D)atomic-scale study on the growth characteristics of{10-12}twin in magnesium(Mg).The study was performed by MD simulations on Mg single crystals with an initial twin nucleus structures.A detailed atomistic analysis reveals that a stabilized 3D{10-12}twin nucleus is bounded by basal/prismatic(BP)interfaces,prismatic/basal(PB)interfaces,and{10-11}interfaces.Later,a{10-12}twin boundary(TB)occurs at the junction of the BP and PB interface with the growth of the twin nucleus.In this process,two twinning mechanisms are involved:a pure-shuffle mechanism in which{10-11}interface migration along the[11-20]direction is mediated by atomic shuffle,and a glide-shuffle mechanism in which BP/PB and{10-12}TB movements are realized by the migration of disconnections along the relevant interfaces.In addition,we systematically investigate the stress state associated with the activation of twinning,aiming to discover the intrinsic relationship of the elastic stress field to twin growth on an atomic scale.The results suggest that the elastic stress in the matrix is an important driving force for twin growth,much similar to what stress does for a crack.In addition,it is rather remarkable that the{10-11}interface has a greater ability to migrate than other interfaces,and this is thought to be a main factor for the rapid growth of a{10-12}twin.展开更多
AIM To determine the relationship between chronic kidney disease(CKD) awareness(CKD-A), self-management behaviors(CKD-SMB) knowledge, performance of CKDSMBs, health literacy(HL) and kidney function. METHODS Participan...AIM To determine the relationship between chronic kidney disease(CKD) awareness(CKD-A), self-management behaviors(CKD-SMB) knowledge, performance of CKDSMBs, health literacy(HL) and kidney function. METHODS Participants were eligible patients attending an outpatient nephrology clinic. Participants were administered: Newest Vital Sign to measure HL, CKD self-managementknowledge tool(CKD-SMKT) to assess knowledge, past performance of CKD-SMB, CKD-A. Estimated GFR(e GFR) was determined using the MDRD-4 equation. Duration of clinic participation and CKD cause were extracted from medical charts. RESULTS One-hundred-fifty patients participated in the study. e GFRs ranged from 17-152 m L/min per 1.73 m2. Majority(83%) of respondents had stage 3 or 4 CKD, low HL(63%), and were CKD aware(88%). Approximately 40%(10/25) of patients in stages 1 and 2 and 6.4%(8/125) in stages 3 and 4 were unaware of their CKD. CKD-A differed with stage(P < 0.001) but not by HL level, duration of clinic participation, or CKD cause. Majority of respondents(≥ 90%) correctly answered one or more CKD-SMKT items. Knowledge of one behavior, "controlling blood pressure" differed significantly by CKD-A. CKD-A was associated with past performance of two CKD-SMBs, "controlling blood pressure"(P = 0.02), and "keeping healthy body weight"(P = 0.01). Adjusted multivariate analyses between CKD-A and:(1) HL; and(2) CKD-SMB knowledge were nonsignificant. However, there was a significant relationship between CKD-A and kidney function after controlling for demographics, HL, and CKD-SMB(P < 0.05). CONCLUSION CKD-A is not associated with HL, or better CKD-SMBs. CKD-A is significantly associated with kidney function and substantially lower e GFR, suggesting the need for focused patient education in CKD stages 1.展开更多
The title compound 1-(3-amino-[1,2,4]triazol-1-yl)-3,3-dimethyl-butan-2-one(3) was synthesized by Hofmann-alkylation reaction of 1-chloro-3,3-dimethyl-butan-2-one(1) and ~1H-[1,2,4]triazol-3-ylamine(2) with eq...The title compound 1-(3-amino-[1,2,4]triazol-1-yl)-3,3-dimethyl-butan-2-one(3) was synthesized by Hofmann-alkylation reaction of 1-chloro-3,3-dimethyl-butan-2-one(1) and ~1H-[1,2,4]triazol-3-ylamine(2) with equal amount of K_2CO_3 as acid acceptor. The structure of compound 3 was characterized by ~1H NMR, 13 C NMR, HRMS and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P21/n with a = 5.7227(8), b = 27.924(4), c = 6.2282(7) ?, β = 101.892(11)°, V = 973.9(2) ?~3, Z = 4, T = 180.00(10) K, μ(MoKα) = 0.087 mm^(-1), Dc = 1.243 g/cm^3, 3832 reflections measured(3.648≤θ≤26.022°), 1916 unique reflections(Rint = 0.0359, Rsigma = 0.0572) used in all calculations. The final R = 0.0557(I 〉 2σ(I)) and w R = 0.1276(all data). Bioassay showed that 3 displayed excellent activity as plant growth regulator with inducing lateral root formation and enhancing primary root elongation at 0.27 mmol/L(50 ppm) in soybeen(He Feng-50). Good water solubility was found with 50 mg in 1 m L of water. Therefore, application of 3 in agriculture is more environmentally friendly due to cosolvent-free condition, and results in improved abiotic-stress tolerance by affecting the root growth. And furthermore, it can be used as a precursor to investigate the function of regulating plant root growth.展开更多
This paper describes the self—adjustment of some tuning-knobs of the generalized predictive controller(GPC).A three feedforward neural network was utilized to on line learn two key tuning-knobs of GPC,and BP algorith...This paper describes the self—adjustment of some tuning-knobs of the generalized predictive controller(GPC).A three feedforward neural network was utilized to on line learn two key tuning-knobs of GPC,and BP algorithm was used for the training of the linking-weights of the neural network.Hence it gets rid of the difficulty of choosing these tuning-knobs manually and provides easier condition for the wide applications of GPC on industrial plants.Simulation results illustrated the effectiveness of the method.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10334060) and The State Key Development Program for Basic Research of China (Grant No 2005CB623602).
文摘Arrays of noble metal nanoparticles show potential applications in (bio-)sensing, optical storage, surface-enhanced spectroscopy, and waveguides. For all such potential devices, controlling the size, morphology, and interparticle spacing of the nanoparticles is very important. Here, we combine seed-mediated growth with nanosphere lithography to study the controllable growth of gold nanoparticles (Au NPs), in which the self-assembly monolayer of polystyrene (PS) on a silicon surface is used to guide the modification of allaunesilanes and the subsequent adsorption of gold seeds; seed-mediated growth is applied to controlling the morphology and size of Au NPs. The size of adsorption region (determining the number of adsorbed gold seeds) is controlled by etching PS microspheres with oxygen plasma or annealing PS microspheres at the glass transition temperature. The size and morphology of the Au NPs are controlled by changing growth conditions. In such a way, we have achieved the dual control of the obtained Au NPs. Preliminary results show that this strategy holds a great promise. This approach can also be extended to a wide range of materials and substrates.
文摘Adventures of Huckleberry Finn is one of the masterpieces of American novelist Mark Twain. In this novel, Twain not onlydescribes the courageous adventures of Huck, but also his psychological or spiritual growth. Due to the social and cultural back-ground of that time and general cultural concept the protagonist was instilled before, the conflicts of the protagonist's self-con-sciousness appear many times in this novel when the issue of slavery is concerned. However, through the protagonist's inner con-flicts, he finally gains spiritual growth and obtains a higher level of moral maturity.
基金supported by grants from the Natural Science Foundation of Zhejiang Province(No.LY20H080001)Medical and Health Science and Technology Projects of Zhejiang Province(No.2021KY997,No.2022KY306,No.2022KY316,No.2023KY263).
文摘Objective Acute myeloid leukemia(AML)is an aggressive hematological malignancy characterized by abnormal myeloid blast expansion.Recent studies have demonstrated that circular RNAs play a role in AML pathogenesis.In this study,we aimed to investigate the clinical significance of circ_0012152 in AML and elucidate its underlying molecular mechanism in the pathogenesis of this condition.Methods Circ_0012152 expression was detected by quantitative real-time polymerase chain reaction in samples obtained from 247 patients with AML and 40 healthy controls.A systematic analysis of clinical characteristics and prognostic factors was also conducted.Cell growth was assessed using the Cell Counting Kit-8(CCK-8)assay,and apoptosis and cell cycle progression were evaluated by flow cytometry.Moreover,RNA pull-down was performed to identify target microRNAs,and transcriptome RNA sequencing and bioinformatics analyses were utilized to identify downstream mRNA targets.Results Circ_0012152 was significantly upregulated in samples from patients with AML and served as an independent adverse prognostic factor for overall survival(OS)(hazard ratio:2.357;95%confidence interval 1.258–4.415).The circ_0012152 knockdown reduced cell growth,increased apoptosis,and inhibited cell cycle progression in AML cell lines.RNA pull-down and sequencing identified miR-652-3p as a target microRNA of circ_0012152.Cell growth inhibition by circ_0012152 knockdown was significantly relieved by miR-652-3p inhibitors.We suggested that miR-652-3p targeted SOX4,as the decrease in SOX4 expression resulting from circ_0012152 knockdown was upregulated by miR-652-3p inhibitors in AML cells.Conclusion Circ_0012152 is an independent poor prognostic factor for OS in AML,and it promotes AML cell growth by upregulating SOX4 through miR-652-3p.
基金Funded by "Hundreds of Talents Program" of Hubei Province,China
文摘Long(15-40 μm), thin(diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To investigate the growth mechanism, we examined the microstructure of these CuNWs at different reaction time. It was found that the CuNWs were actually formed through the self-assembling of Cu nanoparticles along the [110] direction. The transparent electrodes fabricated using the CuNWs achieved a high transparency of 76 % at 31±5 Ω/□.
文摘Quantum dot lasers have excellent characteristics such as temperature stability of threshold current and ultra-high material gain. Quantum dot structures fabricated by self-organized growth have high crystalline perfection, high quantum yield of radiative recombination and high size homogeneity. Main advantages and operating properties of quantum dot lasers fabricated by self-organized growth are briefly introduced.
基金Supported by The Tackling-plan Project of Henan Department of Science and Technology (222102310388)Key Scientific Research Plan of Colleges in Henan Province (22B350002)Henan Provincial Medical Science and Technology Research Plan Joint Construction Project (LHGJ20191520).
文摘Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.
文摘In the rapid development of technology and knowledge-based economy against the background of the times, the IPR of enterprises participating in the process of value creation has been the key issues in the business world. The resulting growth in the value chain of IP is a complicated process of evolution, and non-linear dynamics, and self-organizing system. This paper explores the intellectual property value chain from its conditions, mechanisms and dynamics as well as the inspiration for the enterprises.
文摘The role of self assembled monolayer in inducing the crystal growth was investigated by X ray diffractions (XRD), and scanning electron microscopy (SEM). Results show that crystallization in the absence of monolayer results in a mixture of poorly crystallized calcium phosphates, including hydroxyapatite (HAP) and octacalcium phosphate (OCP), while the presence of self assembled monolayer gives rise to oriented and well crystallized HAP crystals. Moreover, the HAP crystal grows very quickly under the self assembled monolayer, whereas very little calcium phosphate crystals grow without the monolayer. It is rationalized that the hexadecylamine monolayer with high polarity and charged density leads to increase supersaturation and lower the interfacial energy, which attributes to the HAP crystals nucleation. On the other hand, the positive headgroups construct the ordered "recognized site" with distinct size and topology, which results in the oriented HAP crystals deposit.
文摘It is widely known that hypoxia can promote chondrogenesis of human bone marrow de- rived mesenchymal stem cells (hMSCs) in monolayer cultures. However, the direct impact of oxygen tension on hMSC differentiation in three-dimensional cultures is still unknown. This research was de- signed to observe the direct impact of oxygen tension on the ability of hMSCs to "self assemble" into tissue-engineered cartilage constructs, hMSCs were cultured in chondrogenic medium (CM) containing 100 ng/mL growth differentiation factor 5 (GDF-5) at 5% (hypoxia) and 21% (normoxia) 02 levels in monolayer cultures for 3 weeks. After differentiation, the cells were digested and employed in a self- assembly process to produce tissue-engineered constructs under hypoxic and normoxic conditions in vi- tro. The aggrecan and type ]I collagen expression, and type X collagen in the self-assembled con- structs were assessed by using immunofluorescent and immunochemical staining respectively. The methods of dimethylmethylene blue (DMMB), hydroxyproline and PicoGreen were used to measure the total collagen content, glycosaminoglycan (GAG) content and the number of viable cells in each con- struct, respectively. The expression of type II collagen and aggrecan under hypoxic conditions was in- creased significantly as compared with that under normoxic conditions. In contrast, type X collagen expression was down-regulated in the hypoxic group. Moreover, the constructs in hypoxic group showed more significantly increased total collagen and GAG than in normoxic group, which were more close to those of the natural cartilage. These findings demonstrated that hypoxia enhanced chondro- genesis of in vitro, scaffold-free, tissue-engineered constructs generated using hMSCs induced by GDF-5. In hypoxic environments, the self-assembled constructs have a Thistological appearance and biochemical parameters similar to those of the natural cartilage.
基金supported by the National Key Basic Research Program of China(2013CB036405)the National Natural Science Foundation of China(11002154,41272349,and 41372315)the CAS/SAFEA International Partnership Program for Creative Research Teams(KZCX2-YW-T12)
文摘A method of continuous-discontinuous cellular automaton for modeling the growth and coalescence of multiple cracks in brittle material is presented. The method uses the level set to track arbitrary discontinuities, and calculation grids are independent of the discontinuities and no remeshing are required with the crack growing. Based on Grif- fith fracture theory and Mohr-Coulumb criterion, a mixed fracture criterion for multiple cracks growth in brittle mate- rial is proposed. The method treats the junction and coales- cence of multiple cracks, and junction criterion and coales- cence criterion for brittle material are given, too. Besides, in order to overcome the tracking error in the level set ap- proximation for crack junction and coalescence, a dichotomy searching algorithm is proposed. Introduced the above the- ories into continuous-discontinuous cellular automaton, the present method can be applied to solving multiple crack growth in brittle material, and only cell stiffness is needed and no assembled global stiffness is needed. Some numerical examples are given to shown that the present method is efficient and accurate for crack junction, coalescence and percolation problems.
基金Supported by the National Natural Science Foundation of China(No.31602208)the K.C.Wong Magna Fund in Ningbo Universitythe Qingdao Post-doctoral Application Research Project(No.Y6KY01110N)
文摘Self-feeding device is extensively used in aquaculture farms, but for salmonids the individual feeding behavior has seldom been continuously observed. In this article, the individual self-feeding behavior of 10 rainbow trout was continuously monitored with a PIT tag record for 50 days with three replicates. The?sh fell into three categories according to their feeding behavior, i.e. high triggering ?sh(trigger behavior more than 25% of the group, HT), low triggering ?sh(1%–25%, LT) and zero triggering ?sh(less than1%). The results showed that in a group of 10 individual 1–2 HT ?sh accounted for most of the self-feeding behavior(78.19%–89.14%), which was far more than they could consume. The trigger frequency of the?sh was signi?cantly correlated with the initial body weight( P <0.01), however, no signi?cant dif ference in growth rate among the HT, LT, and ZT ?sh was observed( P >0.05). Cosinor analysis showed that the two HT ?sh in the same group had similar acrophase. Though some of the HT ?sh could be active for 50 d, there were also HT ?sh decreased triggering behavior around 40 d and the high trigger status was then replaced by other ?sh, which was ?rst discovered in salimonds. Interestingly, the growth of the group was not af fected by the alternation triggering ?sh. These results provide evidence that in the self-feeding system the HT ?sh didn't gain much advantage by their frequent self-feeding behavior, and high trigger status of the HT ?sh is not only an individual character but also driven by the demand of the group. In the self-feeding system, the critical individual should be closely monitored.
基金sponsored by the Major State Basic Research Development Program of China (973program,Grant No.2007CB613700)the International S&T cooperation program of Gansu Province (Grant No.090WCGA894)
文摘A novel cast processing method,self-inoculation method (SIM),was proposed.The process involves the addition of self-inoculant to melt,then pouring the melt to a mould through a multi-stream mixing cooling channel.In this paper,the process parameters were investigated.Results indicate that the melt treatment temperature,the amount of self-inoculant added,and the slope angle of the cooling channel are the key factors for SIM process.The optimized parameters are that the melt treatment temperature is between 680 and 700°C;the addition of self-inoculant is between 5wt.% and 7wt.%;and the slope angle of the cooling channel is between 30° and 45°.Further analysis reveals that SIM changes the solidification microstructure of slurry by controlling the nucleation and growth of the primary phase in the melt.
基金Funded by the National Natural Science Foundation of China (No.30571873)
文摘The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells (PSCs) into chondrocytes was studied. KLD-12 was synthesized by solid-state method. After TGF-β3 plasmid was loaded into KLD-12 self-assembling peptide nanofiber scaffold, DNA release ability was investigated. PSCs and hTGF-β3 gene were loaded into KLD-12 3-D scaffold, and MTT assay was performed to investigate the cell proliferation, and ELASA assay was used to investigate the expression of TGF-β3. Specific cartilage matrix was examined by quantitative real-time PCR, immunohistochemistry and Alcian Blue staining. Compared with control group, DNA synthesis level of PSCs reached the peak within 3 days when PSCs were cultured in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, and maintained this high level within 2 weeks. MTT results showed that the proliferation ability of experimental group was statistically higher than that in control group (P〈0.05). Quantitative real-time PCR suggested that the percentage of TGF-β3 positive PSCs in experimental group was higher than that in control group (P〈0.01). ELISA assay showed that the TGF-β3 protein level increased in supernatant of experimental group's PSCs, reached the peak after 72 h and then declined a little to the plateau phase. Compared with the control group, the specific gene of chondrocyte typical extracellular matrix significantly up-regulated (P〈0.01). The results showed that PSCs differentiated into chondrocytes in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, which provided a fresh approach to cartilage tissue engineering.
基金The authors are grateful for the support from the National Natural Science Foundation of China(No.51471038)the Fundamental Research Funds for the Central Universities(No.2018CDPTCG0001/42)the National special support program for high-level personnel recruitment.
文摘In this work,we carried out three-dimensional(3D)atomic-scale study on the growth characteristics of{10-12}twin in magnesium(Mg).The study was performed by MD simulations on Mg single crystals with an initial twin nucleus structures.A detailed atomistic analysis reveals that a stabilized 3D{10-12}twin nucleus is bounded by basal/prismatic(BP)interfaces,prismatic/basal(PB)interfaces,and{10-11}interfaces.Later,a{10-12}twin boundary(TB)occurs at the junction of the BP and PB interface with the growth of the twin nucleus.In this process,two twinning mechanisms are involved:a pure-shuffle mechanism in which{10-11}interface migration along the[11-20]direction is mediated by atomic shuffle,and a glide-shuffle mechanism in which BP/PB and{10-12}TB movements are realized by the migration of disconnections along the relevant interfaces.In addition,we systematically investigate the stress state associated with the activation of twinning,aiming to discover the intrinsic relationship of the elastic stress field to twin growth on an atomic scale.The results suggest that the elastic stress in the matrix is an important driving force for twin growth,much similar to what stress does for a crack.In addition,it is rather remarkable that the{10-11}interface has a greater ability to migrate than other interfaces,and this is thought to be a main factor for the rapid growth of a{10-12}twin.
文摘AIM To determine the relationship between chronic kidney disease(CKD) awareness(CKD-A), self-management behaviors(CKD-SMB) knowledge, performance of CKDSMBs, health literacy(HL) and kidney function. METHODS Participants were eligible patients attending an outpatient nephrology clinic. Participants were administered: Newest Vital Sign to measure HL, CKD self-managementknowledge tool(CKD-SMKT) to assess knowledge, past performance of CKD-SMB, CKD-A. Estimated GFR(e GFR) was determined using the MDRD-4 equation. Duration of clinic participation and CKD cause were extracted from medical charts. RESULTS One-hundred-fifty patients participated in the study. e GFRs ranged from 17-152 m L/min per 1.73 m2. Majority(83%) of respondents had stage 3 or 4 CKD, low HL(63%), and were CKD aware(88%). Approximately 40%(10/25) of patients in stages 1 and 2 and 6.4%(8/125) in stages 3 and 4 were unaware of their CKD. CKD-A differed with stage(P < 0.001) but not by HL level, duration of clinic participation, or CKD cause. Majority of respondents(≥ 90%) correctly answered one or more CKD-SMKT items. Knowledge of one behavior, "controlling blood pressure" differed significantly by CKD-A. CKD-A was associated with past performance of two CKD-SMBs, "controlling blood pressure"(P = 0.02), and "keeping healthy body weight"(P = 0.01). Adjusted multivariate analyses between CKD-A and:(1) HL; and(2) CKD-SMB knowledge were nonsignificant. However, there was a significant relationship between CKD-A and kidney function after controlling for demographics, HL, and CKD-SMB(P < 0.05). CONCLUSION CKD-A is not associated with HL, or better CKD-SMBs. CKD-A is significantly associated with kidney function and substantially lower e GFR, suggesting the need for focused patient education in CKD stages 1.
基金supported by the National Natural Science Foundation of China(No.2012BAD20B04)
文摘The title compound 1-(3-amino-[1,2,4]triazol-1-yl)-3,3-dimethyl-butan-2-one(3) was synthesized by Hofmann-alkylation reaction of 1-chloro-3,3-dimethyl-butan-2-one(1) and ~1H-[1,2,4]triazol-3-ylamine(2) with equal amount of K_2CO_3 as acid acceptor. The structure of compound 3 was characterized by ~1H NMR, 13 C NMR, HRMS and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P21/n with a = 5.7227(8), b = 27.924(4), c = 6.2282(7) ?, β = 101.892(11)°, V = 973.9(2) ?~3, Z = 4, T = 180.00(10) K, μ(MoKα) = 0.087 mm^(-1), Dc = 1.243 g/cm^3, 3832 reflections measured(3.648≤θ≤26.022°), 1916 unique reflections(Rint = 0.0359, Rsigma = 0.0572) used in all calculations. The final R = 0.0557(I 〉 2σ(I)) and w R = 0.1276(all data). Bioassay showed that 3 displayed excellent activity as plant growth regulator with inducing lateral root formation and enhancing primary root elongation at 0.27 mmol/L(50 ppm) in soybeen(He Feng-50). Good water solubility was found with 50 mg in 1 m L of water. Therefore, application of 3 in agriculture is more environmentally friendly due to cosolvent-free condition, and results in improved abiotic-stress tolerance by affecting the root growth. And furthermore, it can be used as a precursor to investigate the function of regulating plant root growth.
基金Supported by the National 863 CIMS Project Foundation(863-511-010)Tianjin Natural Science Foundation(983602011)Backbone Young Teacher Project Foundation of Ministry of Education
文摘This paper describes the self—adjustment of some tuning-knobs of the generalized predictive controller(GPC).A three feedforward neural network was utilized to on line learn two key tuning-knobs of GPC,and BP algorithm was used for the training of the linking-weights of the neural network.Hence it gets rid of the difficulty of choosing these tuning-knobs manually and provides easier condition for the wide applications of GPC on industrial plants.Simulation results illustrated the effectiveness of the method.