Aiming at the deficiency of the robustness of thermal error compensation models of CNC machine tools, the mechanism of improving the models' robustness is studied by regarding the Leaderway-V450 machining center as t...Aiming at the deficiency of the robustness of thermal error compensation models of CNC machine tools, the mechanism of improving the models' robustness is studied by regarding the Leaderway-V450 machining center as the object. Through the analysis of actual spindle air cutting experimental data on Leaderway-V450 machine, it is found that the temperature-sensitive points used for modeling is volatility, and this volatility directly leads to large changes on the collinear degree among modeling independent variables. Thus, the forecasting accuracy of multivariate regression model is severely affected, and the forecasting robustness becomes poor too. To overcome this effect, a modeling method of establishing thermal error models by using single temperature variable under the jamming of temperature-sensitive points' volatility is put forward. According to the actual data of thermal error measured in different seasons, it is proved that the single temperature variable model can reduce the loss of fore- casting accuracy resulted from the volatility of tempera- ture-sensitive points, especially for the prediction of cross quarter data, the improvement of forecasting accuracy is about 5 μm or more. The purpose that improving the robustness of the thermal error models is realized, which can provide a reference for selecting the modelingindependent variable in the application of thermal error compensation of CNC machine tools.展开更多
The forecast of sterile alteration for the temperature-sensitive genic male sterile (TGMS) line in two-line hybrid rice seed production was traditionally based on screen temperature determined by weather station. Th...The forecast of sterile alteration for the temperature-sensitive genic male sterile (TGMS) line in two-line hybrid rice seed production was traditionally based on screen temperature determined by weather station. The article put forward a new approach based on plant temperature, which was more exact and direct than the traditional method. The result of the simulation of the self-seeded setting rate of a widely used TGMS line, Peiai64S, by several temperature parameters and durations, showed that the fertility was directly affected by the plant temperature at a height of 20 cm or the air temperature around it in three days duration. Using the stem temperature of three days at a height of 20 cm as the simulation parameter, the fertility of Peiai64S had the maximum, minimum and optimum temperatures as 22.8, 21.7 and 22.5℃, respectively, whereas 23.2, 21.5 and 21.8℃ when using the air temperature of three days around the height of 20 cm as the parameter. Such temperature indices can be used to conclude the sterile alteration of TGMS for safeguarding seed production of twoline hybrid rice. The article also established a statistic model to conclude plant temperature by water temperatures at inflow and outflow, and air temperature and cloudage from weather station.展开更多
The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytic...The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.展开更多
A temperature-sensitive (ts) mutant of the CHO-K1 cell line, tsTM18, grows at 340C but not at 390C. Smu1 is the gene responsible for ts defects of tsTM18 cells. Previously, we found that the Smu1 ts defect altered the...A temperature-sensitive (ts) mutant of the CHO-K1 cell line, tsTM18, grows at 340C but not at 390C. Smu1 is the gene responsible for ts defects of tsTM18 cells. Previously, we found that the Smu1 ts defect altered the localization (as indicated by enlargement of speckles) of SRSF1 (SF2/ASF) in tsTM18 cells cultured at 390C, suggesting a functional association between Smu1 and SRSF1. Speckles are subnuclear structures that may function as storage/assembly/ modification compartments to supply splicing factors to active transcription sites. The effect of the ts defect of Smu1 on the localization of other factors related to splicing has not been characterized yet. The mechanisms underlying the enlargement of speckles of SRSF1 remain unclear. In the present study, we found that the ts defect of Smu1 affected the nuclear localization of a splicing factor, SRSF2 (SC35), and factors involved in the exon-exon junction complex, Y14 and ALY. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the ts defect of Smu1 affected alternative splicing of endogenous Clk1/ Sty and SRSF2 genes. Mammalian Clk family kinases are shown to phosphorylate serine/arginine (SR) proteins in vitro and SRSF1 in vivo. RT-PCR analysis of Clk1/Sty showed an accumulation of the truncated form lacking kinase activity in tsTM18 cells incubated at 39?C. These data indicate that an accumulation of kinase-negative Clk1/Sty may lead to alteration of the localization of factors related to splicing resulting in the enlargement of speckles.展开更多
A kind of novel copolymer hydrogel of poly(N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide) (poly[DMAEMA/NIPAAm]) was synthesized by the initiation of K2S2O8, N, N'-methylene-bis(acrylamide) (Bis...A kind of novel copolymer hydrogel of poly(N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide) (poly[DMAEMA/NIPAAm]) was synthesized by the initiation of K2S2O8, N, N'-methylene-bis(acrylamide) (Bis) was used as the crosslinker. The effects of monomer content, pH and temperature on swelling ratio of the hydrogel were investigated; the thermo-sensitivity in deionized water and in physiological saline was determined. It showed that the swelling ratio of the hydrogel could be changed by changing the temperature or pH alternately. Both swelling ratio and LCST (Lower Critical Solution Temperature) of the hydrogel decreased with the increase of NIPAAm in the co-polymer content.展开更多
A novel series of poly(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (p(NIPAM-co-HEMA)) microgels were prepared through precipitation polymerization. Nuclear magnetic resonance (NMR), transmission electron micro...A novel series of poly(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (p(NIPAM-co-HEMA)) microgels were prepared through precipitation polymerization. Nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV) and dynamic light scattering (DLS) were employed to characterize the microgels. The experimental results indicate that the prepared microgels with narrow distribution remain good temperature sensitivity after incorporation of functional-OH groups. In marked contrast to the general rule, incorporation of hydrophilic HEMA makes the volume-phase-transition temperature shift to the lower temperature due to the strong intermolecular H-bonding between amide and -OH groups, -OH and -OH groups.展开更多
A novel method for the synthesis of macrocyclic graft copolymers was developed through combination of anionic ring-opening polymerization (AROP) and atom transfer radical polymerization (ATRP).A linear α,ω-dihydroxy...A novel method for the synthesis of macrocyclic graft copolymers was developed through combination of anionic ring-opening polymerization (AROP) and atom transfer radical polymerization (ATRP).A linear α,ω-dihydroxyl poly(ethylene oxide) with pendant acetal protected hydroxyl groups (l-poly(EO-co-EEGE)) was prepared first by the anionic copolymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE).Then l-poly(EO-co-EEGE) was cyclized.The crude cyclized product containing the linear byproduct was hydrolyzed and purified by being treated with α-CD.The pure cyclic copolymer [c-poly(EO-co-Gly)] was esterified by reaction with 2-bromoisobutyryl bromide,and then used as ATRP macroinitiators to initiate polymerization of 2-(dimethylamino) ethyl methacrylate (DMAEMA),and a series of pH-and temperature-sensitive macrocyclic graft copolymers composed of a hydrophilic PEO as the ring and PDMAEMA as side chains (c-PEO-g-PDMAEMA) were obtained.The behavior of pH-and temperature-sensitive macrocyclic copolymers was studied in aqueous solution by fluorescence and dynamic light scattering (DLS).The critical micellization pH values of macrocyclic graft copolymers and their corresponding linear graft copolymers (l-PEO-g-PDMAEMA) were measured.Under the same conditions,the cyclic graft copolymer with the shorter side chains gave the higher critical micellization pH value.The c-PEO-g-PDMAEMA showed the lower critical micellization pH value than the corresponding l-PEO-g-PDMAEMA.The average hydrodynamic diameters (Dh) of the micelles were measured by DLS with the variation of the aqueous solution pH value and temperature.展开更多
A new series of cellulose-graft-poly(N-isopropylacrylamide) (cellulose-g-PNIPAM) copolymers were prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide monomers from a cellulose-based m...A new series of cellulose-graft-poly(N-isopropylacrylamide) (cellulose-g-PNIPAM) copolymers were prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide monomers from a cellulose-based macro-initiator, which was homogeneously synthesized in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimC1). The composition of cellulose-g-PNIPAM copolymers could be adjusted by altering the feeding ratio and reaction time. The resultant copolymers with relatively high content of PNIPAM segments (molar substitution of PNIPAM ≥ 18.3) were soluble in water at room temperature. Aqueous solutions of cellulose-g-PNIPAM copolymers exhibited clear temperature-sensitive behavior, and their sol-to-gel phase transition properties were investigated by dynamic light scattering (DLS) and UV measurements. Compared with pure PNIPAM, the cellulose-g-PNIPAM copolymers possessed higher lower critical solution temperatures (LCST) in a range from 36.9 ℃ to 40.8 ℃, which are close to normal human body temperature, and could be tuned by adjusting the content of PNIPAM segments in copolymers. Spherical structure of cellulose-g-PNIPAM copolymers formed at temperatures above LCST and its morphology was observed by TEM and SEM. These novel cellulose-g-PNIPAM copolymers may be attractive substrates for some biomedical applications, such as drug release and tissue engineering.展开更多
For the first time, we are reporting a novel type of dual fluorescence temperaturesensitive DNA-templated silver nanocluster (AgNC) pair, which contains two pieces of single-stranded AgNC in proximity through hybrid...For the first time, we are reporting a novel type of dual fluorescence temperaturesensitive DNA-templated silver nanocluster (AgNC) pair, which contains two pieces of single-stranded AgNC in proximity through hybridization. Both the chameleon AgNC pairs, A-NCP and B-NCP, possess two bright fluorescence peaks that achieve sensitive variations corresponding to temperature change from 15 to 45 ℃. With the increase in temperature, one of the fluorescence emissions of A-NCP (A-FL570) increases, while the other (A-FL640) decreases. However, both the emissions of B-NCP (B-FL685 and B-FL620) decrease simultaneously. Therefore, A-NCP shows a remarkable fluorescence color variation from orange to yellow, while the fluorescence color of B-NCP changes from orange to colorless, with increase in temperature. Moreover, the temperature responding linear range of A-NCP can be regulated by adjusting the structures and sequences of assistant DNA templates. It is assumed that the two single-stranded segmental AgNCs are integrated together as they are assembled into AgNC pairs, leading to a dramatic variation in fluorescence properties. The temperature-sensitive phenomenon is due to the dehybridization-induced separation of two pieces of segmental AgNC, caused by temperature increase. The temperature-sensitive AgNC pairs have been successful in indicating the temperature of living cells, showing the potential for a new application of silver nanocluster as a nanothermometer with adjustable response range, bringing novel insight into the regulatory mechanism of AgNC fluorescence variation.展开更多
An automatic cooling device has been developed by using a temperature-sensitive magnetic fluid as the coolant. A particle image velocimetry (PIV) system was used to measure the flow velocity of the fluid inside the lo...An automatic cooling device has been developed by using a temperature-sensitive magnetic fluid as the coolant. A particle image velocimetry (PIV) system was used to measure the flow velocity of the fluid inside the loop. The efficiency of the device under varying conditions such as the heat load and the power of cooling were ex- perimentally investigated. The effect of cooperation between external magnetic field and thermal field on the performance of the device was studied. As expected, a continuous flow induced by the thermal and magnetic field was observed in the loop, where heat was transferred by the circulating magnetic fluid. The synergic effect between the magnetic field and the temperature gradient has impact on the performance of the device.展开更多
The strong background radiation in high enthalpy hypersonic shock tunnels has posed severe challenges for measurement using luminescent coatings.We proposed a solution for reducing background radiation from time-resol...The strong background radiation in high enthalpy hypersonic shock tunnels has posed severe challenges for measurement using luminescent coatings.We proposed a solution for reducing background radiation from time-resolved temperature-sensitive paint(TSP)measurement in a hypersonic flow with Ma=6.5 and T_(0)=3525 K.The TSP was applied on an inlet ramp model,and the images were taken by a high-speed camera at 2 kHz under a modulated excitation.The strong background radiation led to a low signal-to-noise ratio and significant errors for the first half of the 130-ms test duration.Accordingly,three noise reduction methods were developed and evaluated based on temporal reconstruction,spatial reconstruction and robust principal component analysis(RPCA),respectively.The RPCA method showed the best performance that successfully recovered high-quality TSP data for a majority of test duration(t≥40 ms).展开更多
Background Boanmycin hydrochloride, a new antitumor agent, has a short half-life and fast clearance speed in vivo. The aim of this research was to investigate the effectiveness of peritumor injection of boanmycin hydr...Background Boanmycin hydrochloride, a new antitumor agent, has a short half-life and fast clearance speed in vivo. The aim of this research was to investigate the effectiveness of peritumor injection of boanmycin hydrochloride within temperature-sensitive gel in situ using Hep-G2 hepatoma nude mice model. Methods Nude mice with human Hep-G2 tumor in right flank were randomly divided into four groups: normal saline group, in situ gel only group, boanmycin hydrochloride in situ saline group, and boanmycin hydrochloride in situ gel group, and were treated with injection of corresponding agents into peripheral tissue of the tumor. The volume of the tumor and the body weight of the mice were regularly measured, and tumor growth curve was generated. The size, internal echo, and blood flow of the tumors were observed by color Doppler ultrasonography. Histopathologic changes of the tumor after treatment were observed under both optical and transmission electron microscopy. Results The tumor growth was significantly inhibited by peritumoral therapy in boanmycin hydrochloride in situ gel group with the tumor inhibitory rate of 86.76%. The blood flow of the tumor was still seen in both normal saline group and in situ gel only group on color Doppler ultrasound. Punctate calcification and dotted blood flow were seen in boanmycin hydrochloride group; however, there was massive calcification and no blood flow in the tumor in the boanmycin hydrochlodde in situ gel group. Large areas of necrosis and apoptotic cells were shown by microscopic observation in boanmycin hydrochloride in situ gel group. Conclusion Temperature-sensitive boanmycin hydrochloride in situ gel can effectively delay the release of boanmycin hydrochloride and increase its anticancer effects for liver cancer in animal model.展开更多
To develop a smart free-standing surface enhanced Raman scattering(SERS) substrate,silver nanoparticles(AgNPs) embedded temperature-sensitive nanofibrous membrane was fabricated by electrospinning their aqueous soluti...To develop a smart free-standing surface enhanced Raman scattering(SERS) substrate,silver nanoparticles(AgNPs) embedded temperature-sensitive nanofibrous membrane was fabricated by electrospinning their aqueous solution containing the copolymer poly(N-isopropylacrylamide-co-Nhydroxymethylacrylamide),followed by heat treatment to form crosslinking structure within its constituent nanofibers.To avoid negative effect of the additive like stabilizer and the reactant like reductant on their SERS efficiency,the AgNPs were in-situ synthesized through reducing Ag^+ions dissolved in the polymer solution by ultraviolet irradiation.The prepared hybrid nanofibrous membrane with high stability in aqueous medium can reach its swelling or deswelling equilibrium state within 15 seconds with the medium temperature changing between 25℃and 50℃alternately.When it was used as a free-standing SERS substrate,10^-12 mol/L of 4-nitrothiophenol in aqueous solution can be detected at room temperature,and elevating detection temperature can further lower its low detection limit.Since its generated SERS signal has desirable reproducibility,it can be used as SERS substrate for quantitative analysis.Moreover,the hybrid membrane as SERS substrate is capable of real-time monitoring the reduction of 4-nitrothiophenol into 4-aminothiophenol catalyzed by its embedded AgNPs,and the detected intermediate indicates that the reaction proceeds via a condensation route.展开更多
Silk has been widely used in the clothing industry due to their soft and smooth features,good biocompatibility,good heat dissipation,warmth and ultraviolet resistance.The application of fragrance to silk can significa...Silk has been widely used in the clothing industry due to their soft and smooth features,good biocompatibility,good heat dissipation,warmth and ultraviolet resistance.The application of fragrance to silk can significantly improve the performance of silk.However,there are two key scientific problems that need to be solved:slowing down the release rate of fragrances and increasing the scent lasting time of silk.In this study,cationic and temperature-sensitive liposomes were designed and prepared to encapsulate eugenol.These fragrance-loaded liposomes significantly slowed down the release rate of the fragrance and controlled the release rate of the fragrance in a thermo-sensitive manner.The liposomes adhered to the silk through electrostatic adsorption interaction.The positive charge on the fragranceloaded liposomes neutralized much negative charge on silk and thereby increasing the adhesion efficiency.展开更多
Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity ...Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.展开更多
Danxiangyouzhenliang rice is a high-quality rice variety derived from the hybrid breeding of Danxiang 12A and Xianghuixiangmiao R133.Its unique temperature-sensitive three-line characteristics endow it with significan...Danxiangyouzhenliang rice is a high-quality rice variety derived from the hybrid breeding of Danxiang 12A and Xianghuixiangmiao R133.Its unique temperature-sensitive three-line characteristics endow it with significant advantages of high and stable yield,and its rice fragrance is exquisite and its taste is delicate.Danxiangyouzhenliang rice showed good resistance to rice blast and bacterial blight.On June 10,2021,Danxiangyouzhenliang rice passed the Guangxi Crop Variety Approval(Guishendao 2021074).Danxiangyouzhenliang rice is suitable to be planted as early and late rice in southern,central and northern Guangxi.This study summarized the breeding process and high-yielding seed production techniques of Danxiangyouzhenliang rice,in order to provide useful reference for rice breeders and growers.展开更多
BACKGROUND Norcantharidin(NCTD)is suitable for the treatment of primary liver cancer,especially early and middle primary liver cancer.This compound can reduce tumors and improve immune function.However,the side effect...BACKGROUND Norcantharidin(NCTD)is suitable for the treatment of primary liver cancer,especially early and middle primary liver cancer.This compound can reduce tumors and improve immune function.However,the side effects of NCTD have limited its application.There is a marked need to reduce the side effects and increase the efficacy of NCTD.AIM To develop a nanomaterial carrier,NCTD-loaded metal-organic framework IRMOF-3 coated with a temperature-sensitive gel(NCTD-IRMOF-3-Gel),aiming to improve the anticancer activity of NCTD and reduce the drug dose.METHODS NCTD-IRMOF-3-Gel was obtained by a coordination reaction.The apparent characteristics and in vitro release of NCTD-IRMOF-3-Gel were investigated.Cell cytotoxicity assays,flow cytometry,and apoptosis experiments in mouse hepatoma(Hepa1-6)cells were used to determine the anti-liver cancer activity of NCTD-IRMOF-3-Gel in in vitro models.RESULTS The particle size of NCTD-IRMOF-3-Gel was 50-100 nm,and the particle size distribution was uniform.The release curve showed that NCTD-IRMOF-3-Gel had an obvious sustained-release effect.The cytotoxicity assays showed that the free drug NCTD and NCTD-IRMOF-3-Gel treatments markedly inhibited Hepa1-6 cell proliferation,and the inhibition rate increased with increasing drug concentration.By flow cytometry,NCTD-IRMOF-3-Gel was observed to block the Hepa1-6 cell cycle in the S and G2/M phases,and the thermosensitive gel nanoparticles may inhibit cell proliferation by inducing cell cycle arrest.Apoptosis experiments showed that NCTD-IRMOF-3-Gel induced the apoptosis of Hepa1-6 cells.CONCLUSION Our results indicated that the NCTD-IRMOF-3-Gel may be beneficial for liver cancer disease treatment.展开更多
Coronaviruses (CoVs) are generally associated with respiratory and enteric infections and have long been recognized as important pathogens of livestock and companion animals. Mouse hepatitis virus (MHV) is a widely st...Coronaviruses (CoVs) are generally associated with respiratory and enteric infections and have long been recognized as important pathogens of livestock and companion animals. Mouse hepatitis virus (MHV) is a widely studied model system for Coronavirus replication and pathogenesis. In this study,we created a MHV-A59 temperature sensitive (ts) mutant Wu"-ts18(cd) using the recombinant vaccinia reverse genetics system. Virus replication assay in 17C1-1 cells showed the plaque phenotype and replication characterization of constructed Wu"-ts18(cd) were indistinguishable from the reported ts mutant Wu"-ts18. Then we cultured the ts mutant Wu"-ts18(cd) at non-permissive temperature 39.5°C,which "forced" the ts recombinant virus to use second-site mutation to revert from a ts to a non-ts phenotype. Sequence analysis showed most of the revertants had the same single amino acid mutation at Nsp16 position 43. The single amino acid mutation at Nsp16 position 76 or position 130 could also revert the ts mutant Wu"-ts18 (cd) to non-ts phenotype,an additional independent mutation in Nsp13 position 115 played an important role on plaque size. The results provided us with genetic information on the functional determinants of Nsp16. This allowed us to build up a more reasonable model of CoVs replication-transcription complex.展开更多
Fluorescence imaging is a noninvasive and dynamic real-time imaging technique;however,it exhibits poor spatial resolution in centimeter-deep tissues because biological tissues are highly scattering media for optical r...Fluorescence imaging is a noninvasive and dynamic real-time imaging technique;however,it exhibits poor spatial resolution in centimeter-deep tissues because biological tissues are highly scattering media for optical radiation.The recently developed ultrasound-controlled fluorescence(UCF)imaging is a novel imaging technique that can overcome this bottleneck.Previous studies suggest that the effective contrast agent and sensitive imaging system are the two pivotal factors for generating high-resolution UCF images ex vivo and/or in vivo.Here,this review highlights the recent advances(2015e2020)in the design and synthesis of contrast agents and the improvement of imaging systems to realize high-resolution UCF imaging of deep tissues.The imaging performances of various UCF systems,including the signal-to-noise ratio,imaging resolution,and imaging depth,are specifically discussed.In addition,the challenges and prospects are highlighted.With continuously increasing research interest in this field and emerging multidisciplinary applications,UCF imaging with higher spatial resolution and larger imaging depth may be developed shortly,which is expected to have a far-reaching impact on disease surveillance and/or therapy.展开更多
Polyurethane is enjoying a widespread use as a polymer-based waterproof material in civil engineering In the present study we consider a temperature-sensitive waterproof and moisture-permeable polyurethane material(PT...Polyurethane is enjoying a widespread use as a polymer-based waterproof material in civil engineering In the present study we consider a temperature-sensitive waterproof and moisture-permeable polyurethane material(PTPE-PU)characterized by one or more phase transition temperatures(critical temperatures).Near the critical temperature,the waterproof and moisture permeability of polyurethane undergo abrupt changes.The related stability,thermal performance,water resistance,hydrostatic pressure,and moisture permeability are investigated here considering a PTPE-PU traditionally used in bridge geotechnical engineering.The results show that the moisture permeability of the coated bridge rock and soil undergo sudden variations near the crystallization and melting temperature of the soft segment.The moisture permeability is 3000 g/(m^(2)d).The hydrostatic pressure of the coated bridge rock and soil is 3.5 kPa.展开更多
基金Supported by Key Project of National Natural Science Fund of China(Grant No.51490660/51490661)National Natural Science Foundation of China(Grant No.51175142)
文摘Aiming at the deficiency of the robustness of thermal error compensation models of CNC machine tools, the mechanism of improving the models' robustness is studied by regarding the Leaderway-V450 machining center as the object. Through the analysis of actual spindle air cutting experimental data on Leaderway-V450 machine, it is found that the temperature-sensitive points used for modeling is volatility, and this volatility directly leads to large changes on the collinear degree among modeling independent variables. Thus, the forecasting accuracy of multivariate regression model is severely affected, and the forecasting robustness becomes poor too. To overcome this effect, a modeling method of establishing thermal error models by using single temperature variable under the jamming of temperature-sensitive points' volatility is put forward. According to the actual data of thermal error measured in different seasons, it is proved that the single temperature variable model can reduce the loss of fore- casting accuracy resulted from the volatility of tempera- ture-sensitive points, especially for the prediction of cross quarter data, the improvement of forecasting accuracy is about 5 μm or more. The purpose that improving the robustness of the thermal error models is realized, which can provide a reference for selecting the modelingindependent variable in the application of thermal error compensation of CNC machine tools.
文摘The forecast of sterile alteration for the temperature-sensitive genic male sterile (TGMS) line in two-line hybrid rice seed production was traditionally based on screen temperature determined by weather station. The article put forward a new approach based on plant temperature, which was more exact and direct than the traditional method. The result of the simulation of the self-seeded setting rate of a widely used TGMS line, Peiai64S, by several temperature parameters and durations, showed that the fertility was directly affected by the plant temperature at a height of 20 cm or the air temperature around it in three days duration. Using the stem temperature of three days at a height of 20 cm as the simulation parameter, the fertility of Peiai64S had the maximum, minimum and optimum temperatures as 22.8, 21.7 and 22.5℃, respectively, whereas 23.2, 21.5 and 21.8℃ when using the air temperature of three days around the height of 20 cm as the parameter. Such temperature indices can be used to conclude the sterile alteration of TGMS for safeguarding seed production of twoline hybrid rice. The article also established a statistic model to conclude plant temperature by water temperatures at inflow and outflow, and air temperature and cloudage from weather station.
文摘The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.
文摘A temperature-sensitive (ts) mutant of the CHO-K1 cell line, tsTM18, grows at 340C but not at 390C. Smu1 is the gene responsible for ts defects of tsTM18 cells. Previously, we found that the Smu1 ts defect altered the localization (as indicated by enlargement of speckles) of SRSF1 (SF2/ASF) in tsTM18 cells cultured at 390C, suggesting a functional association between Smu1 and SRSF1. Speckles are subnuclear structures that may function as storage/assembly/ modification compartments to supply splicing factors to active transcription sites. The effect of the ts defect of Smu1 on the localization of other factors related to splicing has not been characterized yet. The mechanisms underlying the enlargement of speckles of SRSF1 remain unclear. In the present study, we found that the ts defect of Smu1 affected the nuclear localization of a splicing factor, SRSF2 (SC35), and factors involved in the exon-exon junction complex, Y14 and ALY. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the ts defect of Smu1 affected alternative splicing of endogenous Clk1/ Sty and SRSF2 genes. Mammalian Clk family kinases are shown to phosphorylate serine/arginine (SR) proteins in vitro and SRSF1 in vivo. RT-PCR analysis of Clk1/Sty showed an accumulation of the truncated form lacking kinase activity in tsTM18 cells incubated at 39?C. These data indicate that an accumulation of kinase-negative Clk1/Sty may lead to alteration of the localization of factors related to splicing resulting in the enlargement of speckles.
文摘A kind of novel copolymer hydrogel of poly(N, N-dimethylaminoethyl methacrylate-co-N-isopropylacrylamide) (poly[DMAEMA/NIPAAm]) was synthesized by the initiation of K2S2O8, N, N'-methylene-bis(acrylamide) (Bis) was used as the crosslinker. The effects of monomer content, pH and temperature on swelling ratio of the hydrogel were investigated; the thermo-sensitivity in deionized water and in physiological saline was determined. It showed that the swelling ratio of the hydrogel could be changed by changing the temperature or pH alternately. Both swelling ratio and LCST (Lower Critical Solution Temperature) of the hydrogel decreased with the increase of NIPAAm in the co-polymer content.
文摘A novel series of poly(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (p(NIPAM-co-HEMA)) microgels were prepared through precipitation polymerization. Nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV) and dynamic light scattering (DLS) were employed to characterize the microgels. The experimental results indicate that the prepared microgels with narrow distribution remain good temperature sensitivity after incorporation of functional-OH groups. In marked contrast to the general rule, incorporation of hydrophilic HEMA makes the volume-phase-transition temperature shift to the lower temperature due to the strong intermolecular H-bonding between amide and -OH groups, -OH and -OH groups.
基金support from the National Natural Science Foundation of China (20874013)
文摘A novel method for the synthesis of macrocyclic graft copolymers was developed through combination of anionic ring-opening polymerization (AROP) and atom transfer radical polymerization (ATRP).A linear α,ω-dihydroxyl poly(ethylene oxide) with pendant acetal protected hydroxyl groups (l-poly(EO-co-EEGE)) was prepared first by the anionic copolymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE).Then l-poly(EO-co-EEGE) was cyclized.The crude cyclized product containing the linear byproduct was hydrolyzed and purified by being treated with α-CD.The pure cyclic copolymer [c-poly(EO-co-Gly)] was esterified by reaction with 2-bromoisobutyryl bromide,and then used as ATRP macroinitiators to initiate polymerization of 2-(dimethylamino) ethyl methacrylate (DMAEMA),and a series of pH-and temperature-sensitive macrocyclic graft copolymers composed of a hydrophilic PEO as the ring and PDMAEMA as side chains (c-PEO-g-PDMAEMA) were obtained.The behavior of pH-and temperature-sensitive macrocyclic copolymers was studied in aqueous solution by fluorescence and dynamic light scattering (DLS).The critical micellization pH values of macrocyclic graft copolymers and their corresponding linear graft copolymers (l-PEO-g-PDMAEMA) were measured.Under the same conditions,the cyclic graft copolymer with the shorter side chains gave the higher critical micellization pH value.The c-PEO-g-PDMAEMA showed the lower critical micellization pH value than the corresponding l-PEO-g-PDMAEMA.The average hydrodynamic diameters (Dh) of the micelles were measured by DLS with the variation of the aqueous solution pH value and temperature.
基金financially supported by the National Natural Science Foundation of China(No.51425307)
文摘A new series of cellulose-graft-poly(N-isopropylacrylamide) (cellulose-g-PNIPAM) copolymers were prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide monomers from a cellulose-based macro-initiator, which was homogeneously synthesized in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimC1). The composition of cellulose-g-PNIPAM copolymers could be adjusted by altering the feeding ratio and reaction time. The resultant copolymers with relatively high content of PNIPAM segments (molar substitution of PNIPAM ≥ 18.3) were soluble in water at room temperature. Aqueous solutions of cellulose-g-PNIPAM copolymers exhibited clear temperature-sensitive behavior, and their sol-to-gel phase transition properties were investigated by dynamic light scattering (DLS) and UV measurements. Compared with pure PNIPAM, the cellulose-g-PNIPAM copolymers possessed higher lower critical solution temperatures (LCST) in a range from 36.9 ℃ to 40.8 ℃, which are close to normal human body temperature, and could be tuned by adjusting the content of PNIPAM segments in copolymers. Spherical structure of cellulose-g-PNIPAM copolymers formed at temperatures above LCST and its morphology was observed by TEM and SEM. These novel cellulose-g-PNIPAM copolymers may be attractive substrates for some biomedical applications, such as drug release and tissue engineering.
基金This work was supported by National Natural Science Foundation of China (No. 21375123) and The Ministry of Science and Technology of China (No. 216YFA0203201).
文摘For the first time, we are reporting a novel type of dual fluorescence temperaturesensitive DNA-templated silver nanocluster (AgNC) pair, which contains two pieces of single-stranded AgNC in proximity through hybridization. Both the chameleon AgNC pairs, A-NCP and B-NCP, possess two bright fluorescence peaks that achieve sensitive variations corresponding to temperature change from 15 to 45 ℃. With the increase in temperature, one of the fluorescence emissions of A-NCP (A-FL570) increases, while the other (A-FL640) decreases. However, both the emissions of B-NCP (B-FL685 and B-FL620) decrease simultaneously. Therefore, A-NCP shows a remarkable fluorescence color variation from orange to yellow, while the fluorescence color of B-NCP changes from orange to colorless, with increase in temperature. Moreover, the temperature responding linear range of A-NCP can be regulated by adjusting the structures and sequences of assistant DNA templates. It is assumed that the two single-stranded segmental AgNCs are integrated together as they are assembled into AgNC pairs, leading to a dramatic variation in fluorescence properties. The temperature-sensitive phenomenon is due to the dehybridization-induced separation of two pieces of segmental AgNC, caused by temperature increase. The temperature-sensitive AgNC pairs have been successful in indicating the temperature of living cells, showing the potential for a new application of silver nanocluster as a nanothermometer with adjustable response range, bringing novel insight into the regulatory mechanism of AgNC fluorescence variation.
基金Supported by the National Natural Science Foundation of China (Grant No. 50436020)
文摘An automatic cooling device has been developed by using a temperature-sensitive magnetic fluid as the coolant. A particle image velocimetry (PIV) system was used to measure the flow velocity of the fluid inside the loop. The efficiency of the device under varying conditions such as the heat load and the power of cooling were ex- perimentally investigated. The effect of cooperation between external magnetic field and thermal field on the performance of the device was studied. As expected, a continuous flow induced by the thermal and magnetic field was observed in the loop, where heat was transferred by the circulating magnetic fluid. The synergic effect between the magnetic field and the temperature gradient has impact on the performance of the device.
基金supported by the National Natural Science Foundation of China(Grants 11725209 and 11872038)and funding from Gas Turbine Research Institute of Shanghai Jiao Tong University.
文摘The strong background radiation in high enthalpy hypersonic shock tunnels has posed severe challenges for measurement using luminescent coatings.We proposed a solution for reducing background radiation from time-resolved temperature-sensitive paint(TSP)measurement in a hypersonic flow with Ma=6.5 and T_(0)=3525 K.The TSP was applied on an inlet ramp model,and the images were taken by a high-speed camera at 2 kHz under a modulated excitation.The strong background radiation led to a low signal-to-noise ratio and significant errors for the first half of the 130-ms test duration.Accordingly,three noise reduction methods were developed and evaluated based on temporal reconstruction,spatial reconstruction and robust principal component analysis(RPCA),respectively.The RPCA method showed the best performance that successfully recovered high-quality TSP data for a majority of test duration(t≥40 ms).
文摘Background Boanmycin hydrochloride, a new antitumor agent, has a short half-life and fast clearance speed in vivo. The aim of this research was to investigate the effectiveness of peritumor injection of boanmycin hydrochloride within temperature-sensitive gel in situ using Hep-G2 hepatoma nude mice model. Methods Nude mice with human Hep-G2 tumor in right flank were randomly divided into four groups: normal saline group, in situ gel only group, boanmycin hydrochloride in situ saline group, and boanmycin hydrochloride in situ gel group, and were treated with injection of corresponding agents into peripheral tissue of the tumor. The volume of the tumor and the body weight of the mice were regularly measured, and tumor growth curve was generated. The size, internal echo, and blood flow of the tumors were observed by color Doppler ultrasonography. Histopathologic changes of the tumor after treatment were observed under both optical and transmission electron microscopy. Results The tumor growth was significantly inhibited by peritumoral therapy in boanmycin hydrochloride in situ gel group with the tumor inhibitory rate of 86.76%. The blood flow of the tumor was still seen in both normal saline group and in situ gel only group on color Doppler ultrasound. Punctate calcification and dotted blood flow were seen in boanmycin hydrochloride group; however, there was massive calcification and no blood flow in the tumor in the boanmycin hydrochlodde in situ gel group. Large areas of necrosis and apoptotic cells were shown by microscopic observation in boanmycin hydrochloride in situ gel group. Conclusion Temperature-sensitive boanmycin hydrochloride in situ gel can effectively delay the release of boanmycin hydrochloride and increase its anticancer effects for liver cancer in animal model.
基金the National Natural Science Foundation of China(Nos.51503033,51373030)
文摘To develop a smart free-standing surface enhanced Raman scattering(SERS) substrate,silver nanoparticles(AgNPs) embedded temperature-sensitive nanofibrous membrane was fabricated by electrospinning their aqueous solution containing the copolymer poly(N-isopropylacrylamide-co-Nhydroxymethylacrylamide),followed by heat treatment to form crosslinking structure within its constituent nanofibers.To avoid negative effect of the additive like stabilizer and the reactant like reductant on their SERS efficiency,the AgNPs were in-situ synthesized through reducing Ag^+ions dissolved in the polymer solution by ultraviolet irradiation.The prepared hybrid nanofibrous membrane with high stability in aqueous medium can reach its swelling or deswelling equilibrium state within 15 seconds with the medium temperature changing between 25℃and 50℃alternately.When it was used as a free-standing SERS substrate,10^-12 mol/L of 4-nitrothiophenol in aqueous solution can be detected at room temperature,and elevating detection temperature can further lower its low detection limit.Since its generated SERS signal has desirable reproducibility,it can be used as SERS substrate for quantitative analysis.Moreover,the hybrid membrane as SERS substrate is capable of real-time monitoring the reduction of 4-nitrothiophenol into 4-aminothiophenol catalyzed by its embedded AgNPs,and the detected intermediate indicates that the reaction proceeds via a condensation route.
基金the National High Technology Research and Development Program(No.2016YFA0200303)the Beijing Natural Science Foundation(Nos.L172046,2192057)the National Natural Science Foundation of China(Nos.31771095,21875254 and 51573188)。
文摘Silk has been widely used in the clothing industry due to their soft and smooth features,good biocompatibility,good heat dissipation,warmth and ultraviolet resistance.The application of fragrance to silk can significantly improve the performance of silk.However,there are two key scientific problems that need to be solved:slowing down the release rate of fragrances and increasing the scent lasting time of silk.In this study,cationic and temperature-sensitive liposomes were designed and prepared to encapsulate eugenol.These fragrance-loaded liposomes significantly slowed down the release rate of the fragrance and controlled the release rate of the fragrance in a thermo-sensitive manner.The liposomes adhered to the silk through electrostatic adsorption interaction.The positive charge on the fragranceloaded liposomes neutralized much negative charge on silk and thereby increasing the adhesion efficiency.
基金The authors thank D.Berger,D.Hofmann and C.Kupka in IFW Dresden for helpful technical support.H.R.acknowledges funding from the DFG(Deutsche Forschungsgemeinschaft)within grant number RE3973/1-1.Q.J.,H.R.and K.N.conceived the work.With the support from N.Y.and X.J.,Q.J.and T.G.fabricated the thermoelectric films and conducted the structural and compositional characterizations.Q.J.prepared microchips and fabricated the on-chip micro temperature controllers.Q.J.and N.P.carried out the temperature-dependent material and device performance measurements.Q.J.and H.R.performed the simulation and analytical calculations.Q.J.,H.R.and K.N.wrote the manuscript with input from the other coauthors.All the authors discussed the results and commented on the manuscript.
文摘Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.
文摘Danxiangyouzhenliang rice is a high-quality rice variety derived from the hybrid breeding of Danxiang 12A and Xianghuixiangmiao R133.Its unique temperature-sensitive three-line characteristics endow it with significant advantages of high and stable yield,and its rice fragrance is exquisite and its taste is delicate.Danxiangyouzhenliang rice showed good resistance to rice blast and bacterial blight.On June 10,2021,Danxiangyouzhenliang rice passed the Guangxi Crop Variety Approval(Guishendao 2021074).Danxiangyouzhenliang rice is suitable to be planted as early and late rice in southern,central and northern Guangxi.This study summarized the breeding process and high-yielding seed production techniques of Danxiangyouzhenliang rice,in order to provide useful reference for rice breeders and growers.
基金Supported by National Natural Science Foundation of China,No.82074025 and No.82074271the Heilongjiang Traditional Chinese Medicine Research Project,No.ZHY18-047and Scientific Research Project of Heilongjiang Health Committee,No.2020-293.
文摘BACKGROUND Norcantharidin(NCTD)is suitable for the treatment of primary liver cancer,especially early and middle primary liver cancer.This compound can reduce tumors and improve immune function.However,the side effects of NCTD have limited its application.There is a marked need to reduce the side effects and increase the efficacy of NCTD.AIM To develop a nanomaterial carrier,NCTD-loaded metal-organic framework IRMOF-3 coated with a temperature-sensitive gel(NCTD-IRMOF-3-Gel),aiming to improve the anticancer activity of NCTD and reduce the drug dose.METHODS NCTD-IRMOF-3-Gel was obtained by a coordination reaction.The apparent characteristics and in vitro release of NCTD-IRMOF-3-Gel were investigated.Cell cytotoxicity assays,flow cytometry,and apoptosis experiments in mouse hepatoma(Hepa1-6)cells were used to determine the anti-liver cancer activity of NCTD-IRMOF-3-Gel in in vitro models.RESULTS The particle size of NCTD-IRMOF-3-Gel was 50-100 nm,and the particle size distribution was uniform.The release curve showed that NCTD-IRMOF-3-Gel had an obvious sustained-release effect.The cytotoxicity assays showed that the free drug NCTD and NCTD-IRMOF-3-Gel treatments markedly inhibited Hepa1-6 cell proliferation,and the inhibition rate increased with increasing drug concentration.By flow cytometry,NCTD-IRMOF-3-Gel was observed to block the Hepa1-6 cell cycle in the S and G2/M phases,and the thermosensitive gel nanoparticles may inhibit cell proliferation by inducing cell cycle arrest.Apoptosis experiments showed that NCTD-IRMOF-3-Gel induced the apoptosis of Hepa1-6 cells.CONCLUSION Our results indicated that the NCTD-IRMOF-3-Gel may be beneficial for liver cancer disease treatment.
基金Research Grants from State Key Laboratory of Pathogen and Biosecurity (SKLPBS0918)
文摘Coronaviruses (CoVs) are generally associated with respiratory and enteric infections and have long been recognized as important pathogens of livestock and companion animals. Mouse hepatitis virus (MHV) is a widely studied model system for Coronavirus replication and pathogenesis. In this study,we created a MHV-A59 temperature sensitive (ts) mutant Wu"-ts18(cd) using the recombinant vaccinia reverse genetics system. Virus replication assay in 17C1-1 cells showed the plaque phenotype and replication characterization of constructed Wu"-ts18(cd) were indistinguishable from the reported ts mutant Wu"-ts18. Then we cultured the ts mutant Wu"-ts18(cd) at non-permissive temperature 39.5°C,which "forced" the ts recombinant virus to use second-site mutation to revert from a ts to a non-ts phenotype. Sequence analysis showed most of the revertants had the same single amino acid mutation at Nsp16 position 43. The single amino acid mutation at Nsp16 position 76 or position 130 could also revert the ts mutant Wu"-ts18 (cd) to non-ts phenotype,an additional independent mutation in Nsp13 position 115 played an important role on plaque size. The results provided us with genetic information on the functional determinants of Nsp16. This allowed us to build up a more reasonable model of CoVs replication-transcription complex.
基金supported by the National Natural Science Foundation of China(Grant No.:81703466)the Outstanding Talents Research Start-up Fund of Xuzhou Medical University,China(Grant No.:RC20552107)Xuzhou Science and Technology Bureau,China(Grant No.:KC21292).
文摘Fluorescence imaging is a noninvasive and dynamic real-time imaging technique;however,it exhibits poor spatial resolution in centimeter-deep tissues because biological tissues are highly scattering media for optical radiation.The recently developed ultrasound-controlled fluorescence(UCF)imaging is a novel imaging technique that can overcome this bottleneck.Previous studies suggest that the effective contrast agent and sensitive imaging system are the two pivotal factors for generating high-resolution UCF images ex vivo and/or in vivo.Here,this review highlights the recent advances(2015e2020)in the design and synthesis of contrast agents and the improvement of imaging systems to realize high-resolution UCF imaging of deep tissues.The imaging performances of various UCF systems,including the signal-to-noise ratio,imaging resolution,and imaging depth,are specifically discussed.In addition,the challenges and prospects are highlighted.With continuously increasing research interest in this field and emerging multidisciplinary applications,UCF imaging with higher spatial resolution and larger imaging depth may be developed shortly,which is expected to have a far-reaching impact on disease surveillance and/or therapy.
基金Indoor hydrothermal experimental study on seepage drainage geogrid clay subgrade under temperature change(No.SQ21008).
文摘Polyurethane is enjoying a widespread use as a polymer-based waterproof material in civil engineering In the present study we consider a temperature-sensitive waterproof and moisture-permeable polyurethane material(PTPE-PU)characterized by one or more phase transition temperatures(critical temperatures).Near the critical temperature,the waterproof and moisture permeability of polyurethane undergo abrupt changes.The related stability,thermal performance,water resistance,hydrostatic pressure,and moisture permeability are investigated here considering a PTPE-PU traditionally used in bridge geotechnical engineering.The results show that the moisture permeability of the coated bridge rock and soil undergo sudden variations near the crystallization and melting temperature of the soft segment.The moisture permeability is 3000 g/(m^(2)d).The hydrostatic pressure of the coated bridge rock and soil is 3.5 kPa.