Histological changes that occur during microsporogenesis are documented in a gene-cytoplasmic male sterile rice ( Oryza saliva L.) line, Zhen Shan 97A, its maintainer line, Zhen Shan 97B, and the restorer line, Ce64 o...Histological changes that occur during microsporogenesis are documented in a gene-cytoplasmic male sterile rice ( Oryza saliva L.) line, Zhen Shan 97A, its maintainer line, Zhen Shan 97B, and the restorer line, Ce64 of a Mine hybrid rice production system. In the restorer line, Ce64, the developing microsporocytes have dense cytoplasm and a distinct set of circumferential microtubules around the nucleus. Successive cytokinesis results in the formation of tetrads. The microtubules within the cells of tetrads and microspores radiate from the surface of the nucleus towards the outer edge of the cytoplasm. Subsequent pollen development is normal. During the course of microspore formation tubulin speckles can be found in the cytoplasm. The general pattern of development and microtubule organization in the maintainer lined Zhen Shan 97B, is similar to Ce64, except that a few more tubulin speckles appear during microspore formation. In the case of the mate sterile line, Zhen Shan 97A, a number of abnormalities can be discerned during early microsporogenesis. These include vacuoles forming within the developing microsporocyte and faintly stained microtubules with no defined distribution pattern. Prominent tubulin speckles are common within the cytoplasm. For those microsporocytes that undergo meiosis, no defined organizational patterns of microtubules can be found within the tetrad. All microspores abort soon after. Abnormalities and defects in microtubule organization observed in Zhen Shan 97A showed that complex interactions between the cytoplasm and the nucleus began at very early stage of microsporocyte development.展开更多
Changes in the pattern of microtubule distribution and organization during megagametogenesis in the embryo sac of rice (Oryza sativa L. cv. IR36) were re-examined using a modified polyethylene glycol sectioning techni...Changes in the pattern of microtubule distribution and organization during megagametogenesis in the embryo sac of rice (Oryza sativa L. cv. IR36) were re-examined using a modified polyethylene glycol sectioning technique before immuno-fluorescence staining of microtubules. In the sectioned materials the pattern of distribution and structural organization of the microtubule cytoskeleton were quite well preserved. Fine details of the patterns of structural changes and re-organization of the microtubule cytoskeleton in the major stages of development during embryo sac megagametogenesis (viz. functional megaspore, uni-nucleate, 2-nucleate, 4-nucleate, 8-nucleate and mature stage) could be clearly observed and easily followed. Some new organizational patterns of microtubules associated with the probable movement and positioning of the polar nuclei were observed.展开更多
Paclitaxel (PTX) is one of the most efficient anticancer drugs for the treatment of cancers through β-tubulin-binding. Our previous work indicated that a PTX-derivative hydrogelator Fmoc-Phe-Phe-Lys(paclitaxel)-...Paclitaxel (PTX) is one of the most efficient anticancer drugs for the treatment of cancers through β-tubulin-binding. Our previous work indicated that a PTX-derivative hydrogelator Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr(H2PO3)-OH (1)could promote neuron branching but the underlying mechanism remains unclear. Using tubulin assembly-disassembly assay, in this work, we found that compound 1 obviously delayed more microtubule aggregation than PTX did. Under the catalysis of alkaline phosphatase, Fmoc-Phe-Phe-Lys(paclitaxel)- Tyr(H2PO3)-OH could self-assemble into nanofiber Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr-OH with width comparable to the size of αβ-tubulin dimer. Therefore, we proposed in this work that nanofiber Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr-OH not only inhibits the αβ-tubulin dimer binding to each other but also interferes with the plus end aggregation of microtubule. This work provides a new mechanism of the inhibition of microtubule formation by a PTX- derivative hydrogelator.展开更多
All coal preparation in which fine coal is handled depends to some extent on the wettability of coal surface by water. The content of external water in fine moist material plays significant role on screening. This art...All coal preparation in which fine coal is handled depends to some extent on the wettability of coal surface by water. The content of external water in fine moist material plays significant role on screening. This article probed into the causations why fine moist materials adhere to the screen deck on common vibrator in the process of screening. Although the wetting that results from interactions between the coal surface and water molecules that are determined by the composition of coal matrix (interrelated with coal rank) and heterogeneous constituents such as oxygen function groups, mineral impurities and pores have something to do with adhering, we found that the effect of wettability is not the key causation to agglomeration, in other words, water bridges among particles are the key causation to the fine moist materials’ adhesion. This paper also shows how the capillary adhesive forces forms and how to calculate and measure these forces.展开更多
AIM:To investigate the effect of glyceraldehyde-derived advanced glycation end-products(Glycer-AGEs) on hepatocellular carcinoma(HCC)cells.METHODS:Two HCC cell lines(Hep3B and HepG2 cells)and human umbilical vein endo...AIM:To investigate the effect of glyceraldehyde-derived advanced glycation end-products(Glycer-AGEs) on hepatocellular carcinoma(HCC)cells.METHODS:Two HCC cell lines(Hep3B and HepG2 cells)and human umbilical vein endothelial cells(HUVEC)were used.Cell viability was determined using the WST-8 assay.Western blotting,enzyme linked immunosorbent assay,and real-time reverse transcriptionpolymerase chain reactions were used to detect protein and mRNA.Angiogenesis was evaluated by assessing the proliferation,migration,and tube formation of HUVEC.RESULTS:The receptor for AGEs(RAGE)protein was detected in Hep3B and HepG2 cells.HepG2 cells werenot affected by the addition of Glycer-AGEs.GlycerAGEs markedly increased vascular endothelial growth factor(VEGF)mRNA and protein expression,which is one of the most potent angiogenic factors.Compared with the control unglycated bovine serum albumin(BSA) treatment,VEGF mRNA expression levels induced by the Glycer-AGEs treatment were 1.00±0.10 vs 1.92 ±0.09(P<0.01).Similarly,protein expression levels induced by the Glycer-AGEs treatment were 1.63±0.04 ng/mL vs 2.28±0.17 ng/mL for the 24 h treatment and 3.36±0.10 ng/mL vs 4.79±0.31 ng/mL for the 48 h treatment,respectively(P<0.01).Furthermore,compared with the effect of the control unglycated BSA-treated conditioned medium,the Glycer-AGEstreated conditioned medium significantly increased the proliferation,migration,and tube formation of HUVEC,with values of 122.4%±9.0%vs 144.5%±11.3%for cell viability,4.29±1.53 vs 6.78±1.84 for migration indices,and 71.0±7.5 vs 112.4±8.0 for the number of branching points,respectively(P<0.01).CONCLUSION:These results suggest that Glycer-AGEs-RAGE signaling enhances the angiogenic potential of HCC cells by upregulating VEGF expression.展开更多
Purpose: The present study aimed to investigate the relationship between different types of sport expertise (externally-paced vs. self-paced sports) and vigilance performance in children by evaluating the cardiovas...Purpose: The present study aimed to investigate the relationship between different types of sport expertise (externally-paced vs. self-paced sports) and vigilance performance in children by evaluating the cardiovascular fitness level of the participants. Methods: Three groups of children (11.0 ± 0.2 years) differentiated in terms of their regular sport participation (football players, n = 20; track and field athletes, n = 20; non-athletic controls, n = 20) took part in the study. In one session, participants performed the Leger Multi-stage fitness test to estimate their aerobic fitness level. In another session, participants completed the Psychomotor Vigilance Task (PVT) to evaluate their vigilance performance under 2 conditions of velocity demands (normal vs. speed). Results: The results revealed that both groups of sport practitioners had higher cardiovascular fitness than non-athlete controls. In contrast, no significant differences in the performance PVT were found between track and field athletes and controls. Crucially, football players showed better performance in the PVT than track and field athletes and controls. These between-group differences were not modulated by the speed demands of the task. Conclusion: The major novel finding of this research points to a positive relationship between sport participation and vigilance performance during childhood. We discuss our results in terms of the different hypotheses put forward in the literature to explain the relationship between regular exercise and cognitive fimctioning: the "cardiovascular fitness" and the "cognitive component skills" hypotheses.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/).展开更多
The goal of this research was to determine the impact of nonionic surfactants on drag reduction effect in water and metal oxide nanofluid. Two nonionic surfactants (Rokacet 07 and Rokanol KT) and copper(II) oxide ...The goal of this research was to determine the impact of nonionic surfactants on drag reduction effect in water and metal oxide nanofluid. Two nonionic surfactants (Rokacet 07 and Rokanol KT) and copper(II) oxide wa- ter-based nanofluid were examined. Friction factors in a 4 mm diameter pipe for the Reynolds number between 8000 and 50000 were determined. Results showed that addition of nonionic surfactants caused the decrease of fric- tion factor in water and nanofluid. The drag reduction effect was similar in both cases. Presence of nanoparticles in the system has no great influence on drag reduction effect.展开更多
The upcoming COP23 at Bonn of the UN and its UNFCCC must outline how its COP21 objectives are to be promoted by means of concrete international and national management. Only a massive replacement of fossil fuels and w...The upcoming COP23 at Bonn of the UN and its UNFCCC must outline how its COP21 objectives are to be promoted by means of concrete international and national management. Only a massive replacement of fossil fuels and wood coal by solar power parks, can wind power and atomic power save mankind from the grave threats of global warming. This paper presents a tentative estimation of what is involved with regard to the fulfilment of COP21 's GOAL II--decarbonisation to 30-40 per cent of 2005 level of emissions.展开更多
Stretchable ionic conductors with high transparency and excellent resilience are highly desired for flexible electronics,but traditional ionic conductive hydrogels are easy to dry and freeze.Herein,a newly hybrid cros...Stretchable ionic conductors with high transparency and excellent resilience are highly desired for flexible electronics,but traditional ionic conductive hydrogels are easy to dry and freeze.Herein,a newly hybrid crosslinking strategy is presented for preparing a stretchable and transparent hydrogel by using sodium alginate(SA)and acrylamide based on the unique physically and covalently hybrid crosslinking mechanism,which is transformed into organohydrogel by simple solvent replacement.Due to the combination of hybrid crosslinking double network and hydrogen bond interactions introduced by the glycerin-water binary solvent,the SA-poly(acrylamide)-organohydrogel(SPOH)demonstrates excellent anti-freezing(-20℃)property,stability(>2 days),transparency,stretchability(~1600%)and high ionic conductivity(17.1 mS cm^(-1)).Thus,a triboelectric nanogenerator made from SPOH(O-TENG)shows an instantaneous peak power density of 262 mW m^(-2)at a load resistance of 10 MΩand efficiently harvests biomechanical energy to drive an electronic watch and light-emitting diode.Moreover,The O-TENG exhibits favorable long-term stability(2 weeks)and temperature tolerance(-20℃).In addition,the raw materials can be prepared into SPOH fibers by a simple tubular mold method,exhibiting high transparency,which can be used for laser transmission.The various abilities of the SPOH promise the application of energy harvesting and laser transmission for wearable electronics and biomedical field.展开更多
Nanopumps conducting fluids directionally through nanopores and nanochannels have attracted considerable interest for their potential applications in nanofiltration, water purification, and hydroelectric power generat...Nanopumps conducting fluids directionally through nanopores and nanochannels have attracted considerable interest for their potential applications in nanofiltration, water purification, and hydroelectric power generation Here, we demonstrate by molecular dynamics simulations that an excited vibrating carbon nanotube (CNT) cantilever can act as an efficient and simple nanopump. Water molecules inside the vibrating cantilever are driven by centrifugal forces and can undergo a continuous flow from the fixed to free ends of the CNT. Further extensive simulations show that the pumping function holds good not only for a single-file water chain in a narrow (6,6) CNT, but also for bulk-like water columns inside wider CNTs, and that the water flux increases monotonically with increasing diameter of the nanotube.展开更多
Purpose: The aim of this study is to discuss the results of different intramedullary devices used in the management of paediatric radial neck fractures and to suggest methods to avoid the pitfalls of the technique. M...Purpose: The aim of this study is to discuss the results of different intramedullary devices used in the management of paediatric radial neck fractures and to suggest methods to avoid the pitfalls of the technique. Methods: Thirty patients with isolated Judet III and IV fractures were included in this prospective study. Judet I and II fractures and radial neck fractures associated with other injuries were excluded. The final results were graded using the Metaizeau functional scoring system and Oxford Elbow Score. Results: The functional result was good to excellent in 24 of 30 cases (80%). The mean Oxford Elbow Score was 44.32. The mean follow-up was 40.11 months. The complications seen were radiocapitellar joint penetration - 6 cases at mean 4.87 weeks, redisplacement - 6, radial epiphyseal sclerosis - 5, and heterotopic ossification 1 case. Conclusion: lntramedullary K wires may result in radiocapitellar joint penetration. Titanium Elastic Nail System should not be used as purely fixation devices as they may not prevent redisplacement. Regular follow-up until at least 6 weeks is essential. Patients who have a Judet IV fracture and need open reduction should be given a guarded prognosis. The paper highlights the pitfalls of the technique and makes recommendations regarding the type of implant, follow-up and patient counselling in Judet IV fractures.展开更多
We have studied the property of single-walled ZnO nanotubes with adsorbed water molecules, and theo- retically designed a new sensor for detecting water molecules using single-waJ1ed ZnO nanotubes using a combination ...We have studied the property of single-walled ZnO nanotubes with adsorbed water molecules, and theo- retically designed a new sensor for detecting water molecules using single-waJ1ed ZnO nanotubes using a combination of density functional theory and the non-equilibrium Green's function method. Details of the geometric structures and adsorption energies of the H2O molecules on the ZnO nanotube surface have been investigated, Our computational results demonstrate that the formation of hydrogen bonding between the H2O molecules and the ZnO nanotube, and adsorption energies of the H2O molecules on the ZnO nanotube are larger than the adsorption energies of other gas molecules present in the atmospheric environment. Moreover, the current-voltage curves of the ZnO nanotube with and without H2O molecules adsorbed on its surface are calculated, the results of which showed that the H2O molecules form stable adsorption configurations that could lead to the decrease in current. These results suggest that the single-walled ZnO nanotubes are able to detect and monitor the presence of H2O molecules by applying bias voltages.展开更多
Since the first appearance of vascular plants during evolution, the plant body has become specialized for adaption to land conditions. Much of our knowledge of plant body specialization and the origins of tissues from...Since the first appearance of vascular plants during evolution, the plant body has become specialized for adaption to land conditions. Much of our knowledge of plant body specialization and the origins of tissues from stem cells have been obtained from studies on the dicot Arabidopsis thaliana. However, less is known about plant body specialization in monocots, another important branch of angiosperms. In this study, we analyzed stem cell lineage and differentiation during development of the root and leaf of the monocot model plant rice(Oryza sativa). Our results showed that three body layers of rice are established from stem cells accompanied by progressively reduced pluripotency. Layer 1(L1) is a single-cell layer of epidermis; L2 is the cortex/endodermis in the root and the mesophyll in the leaf; and L3 is the site of vascular initiation. At least two common steps in vascular development are shared between rice root and leaf. The preprocambium divides to form the procambium and root pericycle or leaf outer sheath. The procambium further differentiates into the xylem, phloem and circumambient cells. We found that the outer sheath of leaf vascular bundles originates not only from the preprocambium of L3,but also from the mesophyll precursor cells of L2. In addition, WUSCHEL-RELATED HOMEOBOX(WOX)genes are expressed in not only the stem cell niche but also metaxylem precursor in rice. This pattern differs from that of homologs in Arabidopsis, suggesting that WOX functions have been recruited in different stem cells in dicots and monocots.展开更多
The shell and tube heat exchanger is an essential part of a power plant for recovering heat transfer between the feed water of a boiler and the wasted heat.The baffles are also an important element inside the heat exc...The shell and tube heat exchanger is an essential part of a power plant for recovering heat transfer between the feed water of a boiler and the wasted heat.The baffles are also an important element inside the heat exchanger.Internal materials influence the flow pattern in the bed.The influence of baffles in the velocity profiles was observed using a three-dimensional particle image velocimetry around baffles in a horizontal circular tube.The velocity of the particles was measured before the baffle and between them in the test tube.Results show that the flows near the front baffle flow were parallel to the vertical wall,and then concentrate on the upper opening of the front baffle.The flows circulate in the front and rear baffles.These flow profiles are related to the Reynolds number(Re) or the flow intensity.The velocity profiles at lower Re number showed a complicated mixing,concentrating on the lower opening of the rear baffle as front wall.Swirling flow was employed in this study,which was produced using tangential velocities at the inlet.At the entrance of the front baffle,the velocity vector profiles with swirl were much different from that without swirl.However,velocities between two baffles are not much different from those without swirl.展开更多
A strategy to prepare horizontally aligned single-walled carbon nanotubes(SWNTs) at moderate temperatures(≤600 ℃) were developed.Using ferocene as the catalyst precursor,Fe nanoparticles are formed in the gaseous ph...A strategy to prepare horizontally aligned single-walled carbon nanotubes(SWNTs) at moderate temperatures(≤600 ℃) were developed.Using ferocene as the catalyst precursor,Fe nanoparticles are formed in the gaseous phase and catalyze the nucleation and growth of SWNTs in situ.Then the resultant SWNTs are deposited onto the substrates downstream and aligned by the surface lattice of the ST-cut single crystal quartz.The preparation of SWNT arrays at moderate temperatures is important for combining the tube growth with device fabrication.展开更多
We have previously developed bare narrow-bore capillary chromatography. In this work, high-performance DNA separation was realized for a size range of 10–800 base pairs(bp) utilizing bare narrow-bore capillary chroma...We have previously developed bare narrow-bore capillary chromatography. In this work, high-performance DNA separation was realized for a size range of 10–800 base pairs(bp) utilizing bare narrow-bore capillary chromatography with 750 nm- radius capillaries. Separation behavior of double-stranded DNA(ds DNA) fragments was investigated over a range of eluent concentrations and elution pressures. DNA molecules were hydrodynamically separated in a size-dependent manner in free solution without any sieving matrices, with the longer fragments being eluted out from the capillary earlier. It was found that the eluent concentration variously influenced the transport behavior for different-sized DNA fragments depending upon the configuration of DNA molecules and the association of counterions. Ionic strength of the solutions strongly impacted DNA persistence length. Enhanced elution pressure could shorten analysis time with a slight loss in resolution. Excellent efficiency of two million theoretical plates per meter was achieved, which indicates the enormous potential of bare narrow-bore capillary chromatography for the analysis of DNA fragments. These findings would be useful in understanding the transport behavior of DNA fragments in confined dimensions for chromatography in free solution.展开更多
Objective To observe the efficacy of mild moxibustion combined with functional exercise in the treatment of upper-limb lymphedema after breast cancer surgery and its effect on serum vascular endothelial growth factor ...Objective To observe the efficacy of mild moxibustion combined with functional exercise in the treatment of upper-limb lymphedema after breast cancer surgery and its effect on serum vascular endothelial growth factor C(VEGF-C).Methods Seventy-eight patients were divided into a control group and an observation group by the random number table method,with 39 cases in each group.The control group received functional exercise and the observation group received mild moxibustion plus functional exercise.The differences in circumference between the two upper limbs,the lymphatic flow of the affected upper limb,the disability of arm,shoulder and hand(DASH)score,the functional assessment of cancer therapy-breast(FACT-B)score and serum VEGF-C level between the two groups were compared before and after treatment.Efficacy was evaluated after treatment.Results The total effective rate was significantly higher in the observation group than in the control group(P<0.05).The difference in circumference between the two upper limbs of the two groups decreased significantly after treatment(both P<0.05),but it was significantly lower in the observation group than in the control group(P<0.05).The lymphatic flow of the affected upper limb of the two groups increased significantly after treatment(both P<0.05),but it was significantly greater in the observation group than in the control group(P<0.05).The DASH scores of the two groups decreased significantly after treatment(both P<0.05),but it was significantly lower in the observation group than in the control group(P<0.05).The FACT-B scores of the two groups increased significantly after treatment(both P<0.05),but it was significantly higher in the observation group than in the control group(P<0.05).After treatment,the serum VEGF-C level increased significantly in the observation group(P<0.05),whereas the control group did not show significant change(P>0.05).The post-treatment serum VEGF-C level was significantly higher in the observation group than in the control group(P<0.05).Conclusion The efficacy of mild moxibustion combined with functional exercise for upper-limb lymphedema after breast cancer surgery is certain,which can reduce the difference in circumference between the two upper limbs,increase the lymphatic flow of the affected upper limb,improve the limb function and the quality of life,and regulate the serum VEGF-C level.展开更多
OBJECTIVE: To find scientific reasons for adverse events reported in Traditional Iranian Medicine (TIM) following administration of aqueous extract of Herba Portulacae Oleraceae seed including itching and tingling of ...OBJECTIVE: To find scientific reasons for adverse events reported in Traditional Iranian Medicine (TIM) following administration of aqueous extract of Herba Portulacae Oleraceae seed including itching and tingling of whole body, tachycardia, anxiety, dyspnea and severe nausea. METHODS: Electronic databases including PubMed, Scopus, and Web of Science were searched up to April 2013 to find papers focused on phytochemistry and biological activities of this plant. RESULTS: Among chemical constituents present in Herba Portulacae oleraceae, catecholamines, adenosine and niacin can cause adverse events similar to those reported inTIM. CONCLUSION: Because of the short duration of action of adenosine, catecholamines and niacin seems to be the major role in appearance of ad-verse events reported in TIM for Herba Portulacae Oleraceae seed. Mechanisms with consideration of receptor types and pharmacokinetics of catecholamine and niacin are warranted to confirm this hypothesis.展开更多
文摘Histological changes that occur during microsporogenesis are documented in a gene-cytoplasmic male sterile rice ( Oryza saliva L.) line, Zhen Shan 97A, its maintainer line, Zhen Shan 97B, and the restorer line, Ce64 of a Mine hybrid rice production system. In the restorer line, Ce64, the developing microsporocytes have dense cytoplasm and a distinct set of circumferential microtubules around the nucleus. Successive cytokinesis results in the formation of tetrads. The microtubules within the cells of tetrads and microspores radiate from the surface of the nucleus towards the outer edge of the cytoplasm. Subsequent pollen development is normal. During the course of microspore formation tubulin speckles can be found in the cytoplasm. The general pattern of development and microtubule organization in the maintainer lined Zhen Shan 97B, is similar to Ce64, except that a few more tubulin speckles appear during microspore formation. In the case of the mate sterile line, Zhen Shan 97A, a number of abnormalities can be discerned during early microsporogenesis. These include vacuoles forming within the developing microsporocyte and faintly stained microtubules with no defined distribution pattern. Prominent tubulin speckles are common within the cytoplasm. For those microsporocytes that undergo meiosis, no defined organizational patterns of microtubules can be found within the tetrad. All microspores abort soon after. Abnormalities and defects in microtubule organization observed in Zhen Shan 97A showed that complex interactions between the cytoplasm and the nucleus began at very early stage of microsporocyte development.
文摘Changes in the pattern of microtubule distribution and organization during megagametogenesis in the embryo sac of rice (Oryza sativa L. cv. IR36) were re-examined using a modified polyethylene glycol sectioning technique before immuno-fluorescence staining of microtubules. In the sectioned materials the pattern of distribution and structural organization of the microtubule cytoskeleton were quite well preserved. Fine details of the patterns of structural changes and re-organization of the microtubule cytoskeleton in the major stages of development during embryo sac megagametogenesis (viz. functional megaspore, uni-nucleate, 2-nucleate, 4-nucleate, 8-nucleate and mature stage) could be clearly observed and easily followed. Some new organizational patterns of microtubules associated with the probable movement and positioning of the polar nuclei were observed.
基金This work was supported by the Ministry of Science and Technology of China (No.2016YFA0400904) and the National Natural Science Foundation of China (No.U1532144 and No.21675145).
文摘Paclitaxel (PTX) is one of the most efficient anticancer drugs for the treatment of cancers through β-tubulin-binding. Our previous work indicated that a PTX-derivative hydrogelator Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr(H2PO3)-OH (1)could promote neuron branching but the underlying mechanism remains unclear. Using tubulin assembly-disassembly assay, in this work, we found that compound 1 obviously delayed more microtubule aggregation than PTX did. Under the catalysis of alkaline phosphatase, Fmoc-Phe-Phe-Lys(paclitaxel)- Tyr(H2PO3)-OH could self-assemble into nanofiber Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr-OH with width comparable to the size of αβ-tubulin dimer. Therefore, we proposed in this work that nanofiber Fmoc-Phe-Phe-Lys(paclitaxel)-Tyr-OH not only inhibits the αβ-tubulin dimer binding to each other but also interferes with the plus end aggregation of microtubule. This work provides a new mechanism of the inhibition of microtubule formation by a PTX- derivative hydrogelator.
文摘All coal preparation in which fine coal is handled depends to some extent on the wettability of coal surface by water. The content of external water in fine moist material plays significant role on screening. This article probed into the causations why fine moist materials adhere to the screen deck on common vibrator in the process of screening. Although the wetting that results from interactions between the coal surface and water molecules that are determined by the composition of coal matrix (interrelated with coal rank) and heterogeneous constituents such as oxygen function groups, mineral impurities and pores have something to do with adhering, we found that the effect of wettability is not the key causation to agglomeration, in other words, water bridges among particles are the key causation to the fine moist materials’ adhesion. This paper also shows how the capillary adhesive forces forms and how to calculate and measure these forces.
基金Supported by Grants from the Japan Society for the Promotion of Science,Grant-in-Aid for Scientific Research(B),No.22300264
文摘AIM:To investigate the effect of glyceraldehyde-derived advanced glycation end-products(Glycer-AGEs) on hepatocellular carcinoma(HCC)cells.METHODS:Two HCC cell lines(Hep3B and HepG2 cells)and human umbilical vein endothelial cells(HUVEC)were used.Cell viability was determined using the WST-8 assay.Western blotting,enzyme linked immunosorbent assay,and real-time reverse transcriptionpolymerase chain reactions were used to detect protein and mRNA.Angiogenesis was evaluated by assessing the proliferation,migration,and tube formation of HUVEC.RESULTS:The receptor for AGEs(RAGE)protein was detected in Hep3B and HepG2 cells.HepG2 cells werenot affected by the addition of Glycer-AGEs.GlycerAGEs markedly increased vascular endothelial growth factor(VEGF)mRNA and protein expression,which is one of the most potent angiogenic factors.Compared with the control unglycated bovine serum albumin(BSA) treatment,VEGF mRNA expression levels induced by the Glycer-AGEs treatment were 1.00±0.10 vs 1.92 ±0.09(P<0.01).Similarly,protein expression levels induced by the Glycer-AGEs treatment were 1.63±0.04 ng/mL vs 2.28±0.17 ng/mL for the 24 h treatment and 3.36±0.10 ng/mL vs 4.79±0.31 ng/mL for the 48 h treatment,respectively(P<0.01).Furthermore,compared with the effect of the control unglycated BSA-treated conditioned medium,the Glycer-AGEstreated conditioned medium significantly increased the proliferation,migration,and tube formation of HUVEC,with values of 122.4%±9.0%vs 144.5%±11.3%for cell viability,4.29±1.53 vs 6.78±1.84 for migration indices,and 71.0±7.5 vs 112.4±8.0 for the number of branching points,respectively(P<0.01).CONCLUSION:These results suggest that Glycer-AGEs-RAGE signaling enhances the angiogenic potential of HCC cells by upregulating VEGF expression.
基金supported by a Spanish Ministerio de Educacion y Cultura predoctoral grant(FPU13-05605)to RBproject research grants:Junta de Andalucia Proyecto de Excelencia(SEJ-6414)+1 种基金Ministerio de Economía y Competitividad(PSI2013-46385)to DS and FHMinisterio de Economia y Competitividad(PSI2016-75956-P)to DS
文摘Purpose: The present study aimed to investigate the relationship between different types of sport expertise (externally-paced vs. self-paced sports) and vigilance performance in children by evaluating the cardiovascular fitness level of the participants. Methods: Three groups of children (11.0 ± 0.2 years) differentiated in terms of their regular sport participation (football players, n = 20; track and field athletes, n = 20; non-athletic controls, n = 20) took part in the study. In one session, participants performed the Leger Multi-stage fitness test to estimate their aerobic fitness level. In another session, participants completed the Psychomotor Vigilance Task (PVT) to evaluate their vigilance performance under 2 conditions of velocity demands (normal vs. speed). Results: The results revealed that both groups of sport practitioners had higher cardiovascular fitness than non-athlete controls. In contrast, no significant differences in the performance PVT were found between track and field athletes and controls. Crucially, football players showed better performance in the PVT than track and field athletes and controls. These between-group differences were not modulated by the speed demands of the task. Conclusion: The major novel finding of this research points to a positive relationship between sport participation and vigilance performance during childhood. We discuss our results in terms of the different hypotheses put forward in the literature to explain the relationship between regular exercise and cognitive fimctioning: the "cardiovascular fitness" and the "cognitive component skills" hypotheses.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/).
基金Supported by the State Committee for Scientific Research(Poland)(NN209764040)Michal Drzazga received the Scholarship under the Project DoktoRIS-Scholarship Program for Innovative Silesia Co-financed by the European Union under the European Social Fund
文摘The goal of this research was to determine the impact of nonionic surfactants on drag reduction effect in water and metal oxide nanofluid. Two nonionic surfactants (Rokacet 07 and Rokanol KT) and copper(II) oxide wa- ter-based nanofluid were examined. Friction factors in a 4 mm diameter pipe for the Reynolds number between 8000 and 50000 were determined. Results showed that addition of nonionic surfactants caused the decrease of fric- tion factor in water and nanofluid. The drag reduction effect was similar in both cases. Presence of nanoparticles in the system has no great influence on drag reduction effect.
文摘The upcoming COP23 at Bonn of the UN and its UNFCCC must outline how its COP21 objectives are to be promoted by means of concrete international and national management. Only a massive replacement of fossil fuels and wood coal by solar power parks, can wind power and atomic power save mankind from the grave threats of global warming. This paper presents a tentative estimation of what is involved with regard to the fulfilment of COP21 's GOAL II--decarbonisation to 30-40 per cent of 2005 level of emissions.
基金financially supported by the National Natural Science Foundation of China(52002059 and 51872204)the Belt&Road Young Scientist Exchanges Project of Science and Technology Commission Foundation of Shanghai(20520741000)+1 种基金the Fundamental Research Funds for the Central Universities(20D110631)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(DonghuaUniversity,KF2019)。
文摘Stretchable ionic conductors with high transparency and excellent resilience are highly desired for flexible electronics,but traditional ionic conductive hydrogels are easy to dry and freeze.Herein,a newly hybrid crosslinking strategy is presented for preparing a stretchable and transparent hydrogel by using sodium alginate(SA)and acrylamide based on the unique physically and covalently hybrid crosslinking mechanism,which is transformed into organohydrogel by simple solvent replacement.Due to the combination of hybrid crosslinking double network and hydrogen bond interactions introduced by the glycerin-water binary solvent,the SA-poly(acrylamide)-organohydrogel(SPOH)demonstrates excellent anti-freezing(-20℃)property,stability(>2 days),transparency,stretchability(~1600%)and high ionic conductivity(17.1 mS cm^(-1)).Thus,a triboelectric nanogenerator made from SPOH(O-TENG)shows an instantaneous peak power density of 262 mW m^(-2)at a load resistance of 10 MΩand efficiently harvests biomechanical energy to drive an electronic watch and light-emitting diode.Moreover,The O-TENG exhibits favorable long-term stability(2 weeks)and temperature tolerance(-20℃).In addition,the raw materials can be prepared into SPOH fibers by a simple tubular mold method,exhibiting high transparency,which can be used for laser transmission.The various abilities of the SPOH promise the application of energy harvesting and laser transmission for wearable electronics and biomedical field.
基金This work was supported by the 973 Program (No. 2007CB936204), National and Jiangsu Province National Science Foundation (NSF) (Nos. 10732040, 10802037, 30970557, and BK2008042) of China, and Nanjing University of Aeronautics and Astronautics Funds (No. BCXJ08-02). The authors thank Drs. Yitao Dai, Chun Tang, and Zhuhua Zhang for helpful discussions.
文摘Nanopumps conducting fluids directionally through nanopores and nanochannels have attracted considerable interest for their potential applications in nanofiltration, water purification, and hydroelectric power generation Here, we demonstrate by molecular dynamics simulations that an excited vibrating carbon nanotube (CNT) cantilever can act as an efficient and simple nanopump. Water molecules inside the vibrating cantilever are driven by centrifugal forces and can undergo a continuous flow from the fixed to free ends of the CNT. Further extensive simulations show that the pumping function holds good not only for a single-file water chain in a narrow (6,6) CNT, but also for bulk-like water columns inside wider CNTs, and that the water flux increases monotonically with increasing diameter of the nanotube.
文摘Purpose: The aim of this study is to discuss the results of different intramedullary devices used in the management of paediatric radial neck fractures and to suggest methods to avoid the pitfalls of the technique. Methods: Thirty patients with isolated Judet III and IV fractures were included in this prospective study. Judet I and II fractures and radial neck fractures associated with other injuries were excluded. The final results were graded using the Metaizeau functional scoring system and Oxford Elbow Score. Results: The functional result was good to excellent in 24 of 30 cases (80%). The mean Oxford Elbow Score was 44.32. The mean follow-up was 40.11 months. The complications seen were radiocapitellar joint penetration - 6 cases at mean 4.87 weeks, redisplacement - 6, radial epiphyseal sclerosis - 5, and heterotopic ossification 1 case. Conclusion: lntramedullary K wires may result in radiocapitellar joint penetration. Titanium Elastic Nail System should not be used as purely fixation devices as they may not prevent redisplacement. Regular follow-up until at least 6 weeks is essential. Patients who have a Judet IV fracture and need open reduction should be given a guarded prognosis. The paper highlights the pitfalls of the technique and makes recommendations regarding the type of implant, follow-up and patient counselling in Judet IV fractures.
基金Supported by the National Natural Science Foundation of China under Grant No.11174214the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20090181110080
文摘We have studied the property of single-walled ZnO nanotubes with adsorbed water molecules, and theo- retically designed a new sensor for detecting water molecules using single-waJ1ed ZnO nanotubes using a combination of density functional theory and the non-equilibrium Green's function method. Details of the geometric structures and adsorption energies of the H2O molecules on the ZnO nanotube surface have been investigated, Our computational results demonstrate that the formation of hydrogen bonding between the H2O molecules and the ZnO nanotube, and adsorption energies of the H2O molecules on the ZnO nanotube are larger than the adsorption energies of other gas molecules present in the atmospheric environment. Moreover, the current-voltage curves of the ZnO nanotube with and without H2O molecules adsorbed on its surface are calculated, the results of which showed that the H2O molecules form stable adsorption configurations that could lead to the decrease in current. These results suggest that the single-walled ZnO nanotubes are able to detect and monitor the presence of H2O molecules by applying bias voltages.
基金supported by National Basic Research Program of China(2014CB943500/2012CB910500)the National Natural Science Foundation of China(91419302/31422005)Youth Innovation Promotion Association of Chinese Academy of Sciences
文摘Since the first appearance of vascular plants during evolution, the plant body has become specialized for adaption to land conditions. Much of our knowledge of plant body specialization and the origins of tissues from stem cells have been obtained from studies on the dicot Arabidopsis thaliana. However, less is known about plant body specialization in monocots, another important branch of angiosperms. In this study, we analyzed stem cell lineage and differentiation during development of the root and leaf of the monocot model plant rice(Oryza sativa). Our results showed that three body layers of rice are established from stem cells accompanied by progressively reduced pluripotency. Layer 1(L1) is a single-cell layer of epidermis; L2 is the cortex/endodermis in the root and the mesophyll in the leaf; and L3 is the site of vascular initiation. At least two common steps in vascular development are shared between rice root and leaf. The preprocambium divides to form the procambium and root pericycle or leaf outer sheath. The procambium further differentiates into the xylem, phloem and circumambient cells. We found that the outer sheath of leaf vascular bundles originates not only from the preprocambium of L3,but also from the mesophyll precursor cells of L2. In addition, WUSCHEL-RELATED HOMEOBOX(WOX)genes are expressed in not only the stem cell niche but also metaxylem precursor in rice. This pattern differs from that of homologs in Arabidopsis, suggesting that WOX functions have been recruited in different stem cells in dicots and monocots.
基金supported by the RESEAT program funded by the Ministry of Science,ICT and Future Planning through the National Research Foundation of Koreaby the National Research Laboratory Program of the National Research Foundation(No.2008-0060153)of Korea
文摘The shell and tube heat exchanger is an essential part of a power plant for recovering heat transfer between the feed water of a boiler and the wasted heat.The baffles are also an important element inside the heat exchanger.Internal materials influence the flow pattern in the bed.The influence of baffles in the velocity profiles was observed using a three-dimensional particle image velocimetry around baffles in a horizontal circular tube.The velocity of the particles was measured before the baffle and between them in the test tube.Results show that the flows near the front baffle flow were parallel to the vertical wall,and then concentrate on the upper opening of the front baffle.The flows circulate in the front and rear baffles.These flow profiles are related to the Reynolds number(Re) or the flow intensity.The velocity profiles at lower Re number showed a complicated mixing,concentrating on the lower opening of the rear baffle as front wall.Swirling flow was employed in this study,which was produced using tangential velocities at the inlet.At the entrance of the front baffle,the velocity vector profiles with swirl were much different from that without swirl.However,velocities between two baffles are not much different from those without swirl.
基金supported by Ministry of Science and Technology of China(2016YFA0201904)the National Natural Science Foundation of China(21631002,U1632119)
文摘A strategy to prepare horizontally aligned single-walled carbon nanotubes(SWNTs) at moderate temperatures(≤600 ℃) were developed.Using ferocene as the catalyst precursor,Fe nanoparticles are formed in the gaseous phase and catalyze the nucleation and growth of SWNTs in situ.Then the resultant SWNTs are deposited onto the substrates downstream and aligned by the surface lattice of the ST-cut single crystal quartz.The preparation of SWNT arrays at moderate temperatures is important for combining the tube growth with device fabrication.
基金supported by the National Natural Science Foundation of China(21275014)the Excellent Young Scientists Fund of NSFC(21322501)+3 种基金the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions(CIT&TCD20140309)the Program for New Century Excellent Talents in University(NCET-12-0603)the Beijing Natural Science Foundation ProgramScientific Research Key Program of Beijing Municipal Commission of Education(KZ201310005001)
文摘We have previously developed bare narrow-bore capillary chromatography. In this work, high-performance DNA separation was realized for a size range of 10–800 base pairs(bp) utilizing bare narrow-bore capillary chromatography with 750 nm- radius capillaries. Separation behavior of double-stranded DNA(ds DNA) fragments was investigated over a range of eluent concentrations and elution pressures. DNA molecules were hydrodynamically separated in a size-dependent manner in free solution without any sieving matrices, with the longer fragments being eluted out from the capillary earlier. It was found that the eluent concentration variously influenced the transport behavior for different-sized DNA fragments depending upon the configuration of DNA molecules and the association of counterions. Ionic strength of the solutions strongly impacted DNA persistence length. Enhanced elution pressure could shorten analysis time with a slight loss in resolution. Excellent efficiency of two million theoretical plates per meter was achieved, which indicates the enormous potential of bare narrow-bore capillary chromatography for the analysis of DNA fragments. These findings would be useful in understanding the transport behavior of DNA fragments in confined dimensions for chromatography in free solution.
文摘Objective To observe the efficacy of mild moxibustion combined with functional exercise in the treatment of upper-limb lymphedema after breast cancer surgery and its effect on serum vascular endothelial growth factor C(VEGF-C).Methods Seventy-eight patients were divided into a control group and an observation group by the random number table method,with 39 cases in each group.The control group received functional exercise and the observation group received mild moxibustion plus functional exercise.The differences in circumference between the two upper limbs,the lymphatic flow of the affected upper limb,the disability of arm,shoulder and hand(DASH)score,the functional assessment of cancer therapy-breast(FACT-B)score and serum VEGF-C level between the two groups were compared before and after treatment.Efficacy was evaluated after treatment.Results The total effective rate was significantly higher in the observation group than in the control group(P<0.05).The difference in circumference between the two upper limbs of the two groups decreased significantly after treatment(both P<0.05),but it was significantly lower in the observation group than in the control group(P<0.05).The lymphatic flow of the affected upper limb of the two groups increased significantly after treatment(both P<0.05),but it was significantly greater in the observation group than in the control group(P<0.05).The DASH scores of the two groups decreased significantly after treatment(both P<0.05),but it was significantly lower in the observation group than in the control group(P<0.05).The FACT-B scores of the two groups increased significantly after treatment(both P<0.05),but it was significantly higher in the observation group than in the control group(P<0.05).After treatment,the serum VEGF-C level increased significantly in the observation group(P<0.05),whereas the control group did not show significant change(P>0.05).The post-treatment serum VEGF-C level was significantly higher in the observation group than in the control group(P<0.05).Conclusion The efficacy of mild moxibustion combined with functional exercise for upper-limb lymphedema after breast cancer surgery is certain,which can reduce the difference in circumference between the two upper limbs,increase the lymphatic flow of the affected upper limb,improve the limb function and the quality of life,and regulate the serum VEGF-C level.
文摘OBJECTIVE: To find scientific reasons for adverse events reported in Traditional Iranian Medicine (TIM) following administration of aqueous extract of Herba Portulacae Oleraceae seed including itching and tingling of whole body, tachycardia, anxiety, dyspnea and severe nausea. METHODS: Electronic databases including PubMed, Scopus, and Web of Science were searched up to April 2013 to find papers focused on phytochemistry and biological activities of this plant. RESULTS: Among chemical constituents present in Herba Portulacae oleraceae, catecholamines, adenosine and niacin can cause adverse events similar to those reported inTIM. CONCLUSION: Because of the short duration of action of adenosine, catecholamines and niacin seems to be the major role in appearance of ad-verse events reported in TIM for Herba Portulacae Oleraceae seed. Mechanisms with consideration of receptor types and pharmacokinetics of catecholamine and niacin are warranted to confirm this hypothesis.