Objective:To assess the effect of D-pinitol on pulmonary fibrosis induced by bleomycin.Methods:Sprague-Dawley rats received intratracheal bleomycin(6 IU/kg)to induce pulmonary fibrosis,followed by administration of ei...Objective:To assess the effect of D-pinitol on pulmonary fibrosis induced by bleomycin.Methods:Sprague-Dawley rats received intratracheal bleomycin(6 IU/kg)to induce pulmonary fibrosis,followed by administration of either D-pinitol(5,10,or 20 mg/kg)or vehicle or methylprednisolone(10 mg/kg)over 28 days after bleomycin administration.Lung function,biochemical parameters,serum biochemistry,mRNA expressions,and histological features were observed.Results:D-pinitol at 10 and 20 mg/kg significantly(P<0.05)attenuated bleomycin-induced bronchoalveolar lavage fluid,decreased myeloperoxidase,nitric oxide,malondialdehyde levels,and increased glutathione and superoxide dismutase level.D-pinitol also improved lung function(enhanced pause,frequency of breathing,expired volume,and tidal volume).Besides,D-pinitol significantly(P<0.05)upregulated Nrf2 and downregulated mRNA expressions of TGF-β,collagen-1,and Smad-3.Furthermore,considerably less inflammation(peribronchial,perivascular,and total),Ashcroft,and interstitial fibrosis scores were observed in the D-pinitol group.Conclusions:D-pinitol exerts its effect against bleomycin-induced pulmonary fibrosis via antioxidative and anti-fibrotic pathways.展开更多
An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarize...An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarized light microscopy, a multiangle composite light source was built to achieve the simultaneous observation of wax crystals and emulsified water droplets, as well as their dynamic aggregation process. Main outcomes on the microscopic mechanism were obtained by developed microscopic image processing method. It was found that the microstructure of W/O waxy crude oil emulsion has the evolution of “individual structure--homogeneous aggregate structure--heterogeneous coaggregate structure--floc structure” during the static cooling, which results in the four stages during gelation process. Different from previous studies, the aggregation of emulsified water droplets was found to be more significant and contributes to the formation and development of the wax crystals-emulsified water droplets coaggregate, which plays a decisive role in the further evolution of the gelled microstructure. Time series microscopic images show the dynamic aggregation of emulsified water droplets and wax crystals. Two different aggregation behaviours between wax crystals and water droplets were observed. That wax crystals can not only embed in gaps between adjacent water droplets and enhance the structure, but also surround the outside of the water droplets and continue to grow resulting in the interconnection of different coaggregates to form a larger floc structure. In addition, correlation between viscoelasticity and microstructure evolution of waxy crude oil emulsions of different water contents was discussed. With increasing water contents, the microstructure is changed from wax crystal flocculation structure as the main skeleton and the emulsified water droplets embedded in it, into the aggregation of emulsified water droplets occupying the main position. When the number of wax crystals and water droplets reaches a certain ratio, did wax crystals form coaggregates with emulsified water droplets, and the remaining wax crystals formed an overall flocculation structure, the viscoelasticity of the waxy crude oil emulsion is the highest.展开更多
With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperatur...With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperature drop in storage tanks under actual dynamically changing environments, this paper considers the influence of dynamic thermal environment and internal crude oil physical properties on the fluctuating changes in crude oil temperature. A theoretical model of the unsteady-state temperature drop heat transfer process is developed from a three-dimensional perspective. According to the temperature drop variation law of crude oil storage tank under the coupling effect of various heat transfer modes such as external forced convection, thermal radiation, and internal natural convection, the external dynamic thermal environment influence zone, the internal crude oil physical property influence zone, and the intermediate transition zone of the tank are proposed. And the multiple non-linear regression method is used to quantitatively characterize the influence of external ambient temperature, solar radiation, wind speed, internal crude oil density, viscosity, and specific heat capacity on the temperature drop of crude oil in each influencing zone. The results of this paper not only quantitatively explain the main influencing factors of the oil temperature drop in the top, wall, and bottom regions of the tank, but also provide a theoretical reference for oil security reserves under a dynamic thermal environment.展开更多
The variations of magnetization and magnetostriction with temperature and stress were investigated through the analysis of the effective field,induced by temperature and stress.A nonlinear magnetostrictive model of gi...The variations of magnetization and magnetostriction with temperature and stress were investigated through the analysis of the effective field,induced by temperature and stress.A nonlinear magnetostrictive model of giant magnetostrictive materials was proposed.The proposed model can be used to calculate the magnetostrictive characterization of giant magnetostrictive materials in different temperatures and under different stresses.The coupling effects of axial stress,magnetic field,and temperature on the magnetostriction of a Terfenol-D rod were numerically simulated as well as experimentally tested.Comparison between the calculating and experimental results shows that the proposed model can better describe the magneto-thermo-mechanical characteristics of Terfenol-D rod under different temperatures and compressive stress.Therefore,the proposed model possesses an important significance for the design of magnetostrictive devices.展开更多
AIM: To assess the effectiveness of endoscopic fullthickness resection(EFR) and laparoscopic surgery in the treatment of gastric stromal tumors arising from the muscularis propria.METHODS: Out of 62 gastric stromal tu...AIM: To assess the effectiveness of endoscopic fullthickness resection(EFR) and laparoscopic surgery in the treatment of gastric stromal tumors arising from the muscularis propria.METHODS: Out of 62 gastric stromal tumors arising from the muscularis propria, each > 1.5 cm in diameter, 32 were removed by EFR, and 30 were removed by laparoscopic surgery. The tumor expression of CD34, CD117, Dog-1, S-100, and SMA was assessed immunohistochemically. The operative time, complete resection rate, length of hospital stay, incidence of complications, and recurrence rate were compared between the two groups. Continuous data were compared using in-dependent samples t-tests, and categorical data were compared using χ2 tests.RESULTS: The 32 gastric stromal tumors treated by EFR and the 30 treated by laparoscopic surgery showed similar operative time [20-155 min(mean, 78.5 ± 30.1 min) vs 50-120 min(mean, 80.9 ± 46.7 min), P > 0.05], complete resection rate(100% vs 93.3%, P > 0.05), and length of hospital stay [4-10 d(mean, 5.9 ± 1.4 d) vs 4-19 d(mean, 8.9 ± 3.2 d), P >0.05]. None of the patients treated by EFR experienced complications, whereas two patients treated by laparoscopy required a conversion to laparotomy, and one patient had postoperative gastroparesis. No recurrences were observed in either group. Immunohistochemical staining showed that of the 62 gastric stromal tumors diagnosed by gastroscopy and endoscopic ultrasound, six were leiomyomas(SMA-positive), one was a schwannoglioma(S-100 positive), and the remaining 55 were stromal tumors.CONCLUSION: Some gastric stromal tumors arising from the muscularis propria can be completely removed by EFR. EFR could likely replace surgical or laparoscopic procedures for the removal of gastric stromal tumors.展开更多
The aim of this review was to systematically compare the outcomes of enhanced recovery after surgery(ERAS)with standard care(SC)after radical cystectomy.We performed a systematic search of PubMed,Ovid?Web of Science,a...The aim of this review was to systematically compare the outcomes of enhanced recovery after surgery(ERAS)with standard care(SC)after radical cystectomy.We performed a systematic search of PubMed,Ovid?Web of Science,and the Cochrane Library to identify studies published until September 2017 which involved a comparison of ERAS and SC.A meta-analysis was performed to assess the outcomes of ERAS versus SC.Sixteen studies including 8 prospective and 8 retrospective trials met the eligibility criteria.A total of 2100 participants were assigned to ERAS(1258 cases)or SC(842 cases).The time to first flatus passage[WMD=-0.95 days,95%Cl(-1.50,-0.41),P=0.0006],time until return to a regular diet[WMD=-2.15 days,95%Cl(-2.86,—1.45),P<0.00001]and the length of hospital stay[WMD=-3.75 days,95%Cl(-5.13,-2.36),P<0.00001]were significantly shorter,and the incidence of postoperative complications[OR=0.60,95%Cl(0.44,0.83),P=0.002],especially postoperative paralytic ileus[OR=0.43,95%Cl(0.30,0.62),P<0.00001]and cardiovascular complications[OR=0.28,95%Cl(0.09,0.90),P=0.03]was significantly lower in the ERAS group than those in the SC group.This meta-analysis demonstrated that ERAS was associated with a shorter time to first flatus passage,return of bowel fimction,and the length of hospital stay than SC in patients undergoing radical cystectomy,as well as a lower rate of postoperative complications,especially paralytic ileus and cardiovascular complications.展开更多
Monolithic silica spin column extraction(MonoSpin-SPE)was developed as a simple,sensitive,and eco-friendly pretreatment method which combined with ultra-fast liquid chromatography-mass spectrometry(UFLC-MS)to determin...Monolithic silica spin column extraction(MonoSpin-SPE)was developed as a simple,sensitive,and eco-friendly pretreatment method which combined with ultra-fast liquid chromatography-mass spectrometry(UFLC-MS)to determine the levels of six phthalate esters,dimethyl-(DMP),diethyl-(DEP),dipropyl-[DPrP],butyl-benzyl-(BBP),dicyclohexyl-(DcHP),and di-n-octyl-(DOP)phthalate in physiological saline samples.Under optimized experimental conditions,the method was linear in the following ranges:0.2-50 μg/L for DMP,DEP,DPrP,DcHP and DOP;5-100 μg/L for BBP.The correlation coefficients(R2)were in the range of 0.9951-0.9995 for all the analytes and the limits of detection(LODs)and limits of quantification(LOQs)were in the ranges of 0.02-0.9 μg/L and 0.08-2.7 μg/L,respectively.The pretreatment process showed good reproducibility with inter-day and intra-day relative standard deviations(RSDs)below 8.5% and 11.2%,respectively.This method was used to determine the levels of six phthalate esters in physiological saline samples and the recoveries ranged from 71.2% to 107.3%.DMP and DEP were found in actual physical saline samples(brand A and brand B).展开更多
Primary hyperparathyroidism(PHPT) is rare during pregnancy. A case of twin pregnancy with three simultaneous parathyroid adenomas at the same time has not been reported. Multiple parathyroid lesions are difficult to d...Primary hyperparathyroidism(PHPT) is rare during pregnancy. A case of twin pregnancy with three simultaneous parathyroid adenomas at the same time has not been reported. Multiple parathyroid lesions are difficult to diagnose, as pregnant women who insist upon continuing a pregnancy are not able to undergo 99mTc-sestamibi scintigraphy, so cases of PHPT are easily unobserved and often can have serious consequences for the patient and the fetus. Therefore, we reported a case of a 28-year-old woman mid-pregnancy with twins, who had hypercalcemia and was eventually diagnosed with twin pregnancy with PHPT due to a triple parathyroid adenoma, had good pregnancy outcomes after undergoing surgery in mid-pregnancy. Twin pregnancy with PHPT due to a triple parathyroid adenoma, as presented in this case, is very rare and surgery in mid-pregnancy is demonstrated here as safe. Intraoperative parathormone monitoring was and remains key to a successful operation.展开更多
Certain microRNAs(miRNAs)can function as neuroprotective factors after reperfusion/ischemia brain injury.miRNA-142-3p can participate in the occurrence and development of tumors and myocardial ischemic injury by negat...Certain microRNAs(miRNAs)can function as neuroprotective factors after reperfusion/ischemia brain injury.miRNA-142-3p can participate in the occurrence and development of tumors and myocardial ischemic injury by negatively regulating the activity of Rac1,but it remains unclear whether miRNA-142-3p also participates in cerebral ischemia/reperfusion injury.In this study,a model of oxygen-glucose deprivation/re-oxygenation in primary cortical neurons was established and the neurons were transfected with miR-142-3p agomirs or miR-142-3p antagomirs.miR-142-3p expression was down-regulated in neurons when exposed to oxygen-glucose deprivation/re-oxygenation.Over-expression of miR-142-3p using its agomir remarkably promoted cell death and apoptosis induced by oxygen-glucose deprivation/re-oxygenation and improved mitochondrial biogenesis and function,including the expression of peroxisome proliferator-activated receptor-γcoactivator-1α,mitochondrial transcription factor A,and nuclear respiratory factor 1.However,the opposite effects were produced if miR-142-3p was inhibited.Luciferase reporter assays verified that Rac Family Small GTPase 1(Rac1)was a target gene of miR-142-3p.Over-expressed miR-142-3p inhibited NOX2 activity and expression of Rac1 and Rac1-GTPase(its activated form).miR-142-3p antagomirs had opposite effects after oxygen-glucose deprivation/re-oxygenation.Our results indicate that miR-142-3p down-regulates the expression and activation of Rac1,regulates mitochondrial biogenesis and function,and inhibits oxygen-glucose deprivation damage,thus exerting a neuroprotective effect.The experiments were approved by the Committee of Experimental Animal Use and Care of Central South University,China(approval No.201703346)on March 7,2017.展开更多
The lander of China’s Chang’E-3 spacecraft is equipped with a 15-cm telescope that is very useful for monitoring celestial objects in the ultraviolet(UV) band(245–340 nm).The Lunar-based Ultraviolet Telescope(LUT) ...The lander of China’s Chang’E-3 spacecraft is equipped with a 15-cm telescope that is very useful for monitoring celestial objects in the ultraviolet(UV) band(245–340 nm).The Lunar-based Ultraviolet Telescope(LUT) is the first long-term lunar-based astronomical observatory,that can make uninterrupted observations of a target from the Moon.Here we present the continuous complete UV light curve of the eclipsing binary TX Herculis(TX Her).The analysis of the light curve suggests that TX Her is a detached binary.The dip in the light curve was explained by the emergence of a stellar dark spot on the less massive F0 type component.The cyclic change of arrival eclipse times for the system reveals that it contains an additional stellar companion with a minimal mass of 0.35 M⊙ and a period of 48.92 yr,which is supported by the detected light contribution of the third body from light curve analysis.This third body may play an important role in the formation of the present short-period system TX Her.展开更多
Foaming issues are encountered at the stages in crude oil production, transportation, processing, especially in chemical flooding enhanced oil recovery(EOR) oilfields. These accumulated foams would cause a lot of trou...Foaming issues are encountered at the stages in crude oil production, transportation, processing, especially in chemical flooding enhanced oil recovery(EOR) oilfields. These accumulated foams would cause a lot of trouble for downstream operation. The destruction of foams under ultrasonic has been increasingly paying attention in the background of green oilfield development. This study focuses on the decay kinetic characteristics of alkaline-surfactant-polymer-strengthened foams under the ultrasonic standing wave.The performance of the diverse foams was characterized. A decay kinetic model incorporating the energy correlation was developed and validated. The factors that affect the decay kinetic characteristics were discussed. The results indicated that the collapse rate and the collapse volume fraction decreased when the foam size decreased, the gas-liquid ratio decreased and the surface tension increased. Ultrasonic standing wave parameters have a significant impact on the decay behavior of the foam. Both the ultrasonic frequency and ultrasonic amplitude were increased by 50%, the collapse volume fraction of foams increased by about 1.25 times in the identical irradiation time. The relative deviation between the measured results and the model prediction was less than 10%. The potential collapse mechanism was also explained using the principle of energy correlation of foam surface. This study is not only beneficial to provide a robust and rigorous way to defoam of produced liquid in the alkaline/surfactant/polymer(ASP)flooding EOR process but also meaningful to well understand the decay process of oil-based foams.展开更多
TZ Eri and TU Her are both classic Algol-type systems(Algols). By observing and collecting times of minimum light, we constructed the O-C curves for the two systems. The long-time upward and downward parabolas shown i...TZ Eri and TU Her are both classic Algol-type systems(Algols). By observing and collecting times of minimum light, we constructed the O-C curves for the two systems. The long-time upward and downward parabolas shown in these diagrams are considered to be the result of the combination of mass transfer and angular momentum loss. The secular orbital period change rates are d P/dt = 4.74(±0.12) ×10-7 d yr-1 and d P/dt =-2.33(±0.01) × 10-6 d yr-1, respectively. There are also cyclic variations in their O-C curves which might be caused by the light-travel time effect(LTTE). A circumbinary star may exist in the TZ Eri system with a mass of at least 1.34 M⊙, while there are possibly two celestial bodies that almost follow a 2 : 1 resonance orbit around the TU Her binary pair. Their masses are at least 2.43 M⊙and 1.27 M⊙.展开更多
NSVS 14256825 is the second discovered sdOB+dM eclipsing-binary system with an orbital period of 2.65 h. This special binary was reported to contain circumbinary planets or brown dwarfs by using the timing method. How...NSVS 14256825 is the second discovered sdOB+dM eclipsing-binary system with an orbital period of 2.65 h. This special binary was reported to contain circumbinary planets or brown dwarfs by using the timing method. However, different results were derived by different authors because of the insufficient coverage of eclipse timings. Since 2008, we have monitored this binary for about 10 yr using several telescopes and 84 new times of light minimum were obtained with high precision. It is found that the O-C curve has been increasing recently and it shows a cyclic variation with a period of 8.83 yr and an amplitude of 46.31 seconds. The cyclic change cannot be explained by magnetic activity cycles of the red dwarf component because the required energy is much larger than that radiated by this component in one whole period. This cyclic change detected in NSVS 14256825 could be explained by the light-travel time effect via the presence of a third body. The lowest mass of the third body is determined to be 14.15 Mjupwhich is in the transition range between planets and brown dwarfs. The substellar object is orbiting around this evolved binary at an orbital separation of around 3 AU with an eccentricity of 0.12. These results indicate that NSVS 14256825 is the first sdOB-type eclipsing binary consisting of a hierarchical substellar object.The detection of a close-in substellar companion to NSVS 14256825 will provide some insights on the formation and evolution of sdOB-type binaries and their companions.展开更多
Background: Gastrointestinal symptoms are not rare among coronavirus disease 2019(COVID-19) patients, but there have been no reports regarding convalescent plasma therapy for the recovery of gastrointestinal problems ...Background: Gastrointestinal symptoms are not rare among coronavirus disease 2019(COVID-19) patients, but there have been no reports regarding convalescent plasma therapy for the recovery of gastrointestinal problems in COVID-19 patients.Case presentation: We present two cases of patients with COVID-19-associated recurrent diarrhea and positive fecal occult blood who successfully recovered after a one-time convalescent plasma administration.Conclusion: When COVID-19 patients develop recurrent or refractory gastrointestinal symptoms and fail to respond to the available treatment, alternative therapy with convalescent plasma administration may be considered.展开更多
Targeting immune checkpoints has achieved great therapeutic effects in the treatment of early-stage tumors.However,most patients develop adaptive resistance to this therapy.The latest evidence demonstrates that tumord...Targeting immune checkpoints has achieved great therapeutic effects in the treatment of early-stage tumors.However,most patients develop adaptive resistance to this therapy.The latest evidence demonstrates that tumorderived exosomes may play a key role in systemic immune suppression and tumor progression.In this article,we highlight the role of exosomal immune checkpoint proteins in tumor immunity,with an emphasis on programmed death ligand 1(PD-L1) and cytotoxic T lymphocyte-associated antigen 4(CTLA-4),as well as emerging evidence on roles of T cell immunoglobulin-3(TIM-3),arginase 1(ARG1),and estrogen receptor binding fragment-associated antigen 9(EBAG9) expressed by exosomes.展开更多
The new complete BV Rc Ic light curves and spectra of the short-period eclipsing binary XZ CMi are presented.The results from the combined analysis based on the photometric and spectroscopic data show that XZ CMi is a...The new complete BV Rc Ic light curves and spectra of the short-period eclipsing binary XZ CMi are presented.The results from the combined analysis based on the photometric and spectroscopic data show that XZ CMi is a near contact binary with the secondary component filling its critical Roche lobe while the primary filling 91%of its Roche lobe.The investigation of the O-C diagram reveals that its orbital period is continuously increasing,which is consistent with the derived configuration and caused by the mass transfer from the less massive star to the more massive one.In addition,an obvious periodic modulation with the amplitude of0.0187(±0.0016)d and a high eccentric of 0.86(±0.04)is detected,which could be the results of the light time effect as a third star with the mass no less than 0.42(±0.09)M⊙orbiting around the central eclipsing binary once every 95.7(±2.1)yr.Furthermore,we found a visual companion star at 2.4′′east by south of this system at a much greater distance by direct image.The large third light contribution found from the light curve analysis could be well explained by the existence of the third star and the fourth visual one.The similar parallax and proper motion imply that the components of this hierarchical quadruple system might be bounded by gravitation.Spectroscopic observations for two visual components were carried out by the LAMOST and 2.16 m telescopes,respectively.Their different values of[Fe/H]suggest that they were not born from the same origin.Thus,XZ CMi system is an interesting and important target to study the formation of the multiple stars.展开更多
A variable mass tuned particle absorber is designed for the nonlinear vertical vibration control of the corrugated rolling mill in the composite plate rolling process.Considering the nonlinear damping and nonlinear st...A variable mass tuned particle absorber is designed for the nonlinear vertical vibration control of the corrugated rolling mill in the composite plate rolling process.Considering the nonlinear damping and nonlinear stiffness between the corrugated interface,a three-degree-of-freedom nonlinear vertical vibration mathematical model of corrugated rolling mill based on dynamic vibration absorber control is established.The multi-scale method is used to solve the amplitude–frequency characteristic curve equation of the installed dynamic vibration absorber(DVA)system.The effects of stiffness coefficient and damping coefficient on the amplitude–frequency characteristic curve are analyzed.The expressions of the dynamic developed factor of the corrugated roll are derived,and the influence laws of mass ratio,frequency ratio and damping ratio on the dynamic amplification factor are analyzed.The optimal parameters of the DVA are obtained by adaptive genetic algorithm.The control effect of the DVA on the nonlinear vertical vibration is studied by numerical simulation.The feasibility of the designed dynamic absorber is verified through experiments.The results show that the designed dynamic absorber can effectively suppress the vertical vibration of the corrugated roller.展开更多
The hot deformation behavior of TC18 alloy at strain rates ranging from 1 9 10-4to 1 9 10-2s-1and temperatures ranging from 25 to 800 °C was studied using a WDW-300 electronic universal testing machine. The relat...The hot deformation behavior of TC18 alloy at strain rates ranging from 1 9 10-4to 1 9 10-2s-1and temperatures ranging from 25 to 800 °C was studied using a WDW-300 electronic universal testing machine. The relationships between true stress and true strain show that flow stress decreases with the increase of temperature and increases as strain rate increases. The effect of strain rate on the flow stress becomes pronounced at higher temperatures. At room temperature, the river pattern characteristic of brittle fracture and the dimple pattern typical of ductile fracture are found to exist in different regions of fracture surfaces of the samples. An improved constitutive relationship is proposed to accurately describe the flow stress of TC18 by considering the effect of strain. And a microscopic model is also deduced which can link the physical mechanisms to the macroscopic experimental results. A good agreement is obtained between the predictions of the microscopic model and the results of the macroscopic experiment.展开更多
文摘Objective:To assess the effect of D-pinitol on pulmonary fibrosis induced by bleomycin.Methods:Sprague-Dawley rats received intratracheal bleomycin(6 IU/kg)to induce pulmonary fibrosis,followed by administration of either D-pinitol(5,10,or 20 mg/kg)or vehicle or methylprednisolone(10 mg/kg)over 28 days after bleomycin administration.Lung function,biochemical parameters,serum biochemistry,mRNA expressions,and histological features were observed.Results:D-pinitol at 10 and 20 mg/kg significantly(P<0.05)attenuated bleomycin-induced bronchoalveolar lavage fluid,decreased myeloperoxidase,nitric oxide,malondialdehyde levels,and increased glutathione and superoxide dismutase level.D-pinitol also improved lung function(enhanced pause,frequency of breathing,expired volume,and tidal volume).Besides,D-pinitol significantly(P<0.05)upregulated Nrf2 and downregulated mRNA expressions of TGF-β,collagen-1,and Smad-3.Furthermore,considerably less inflammation(peribronchial,perivascular,and total),Ashcroft,and interstitial fibrosis scores were observed in the D-pinitol group.Conclusions:D-pinitol exerts its effect against bleomycin-induced pulmonary fibrosis via antioxidative and anti-fibrotic pathways.
文摘An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarized light microscopy, a multiangle composite light source was built to achieve the simultaneous observation of wax crystals and emulsified water droplets, as well as their dynamic aggregation process. Main outcomes on the microscopic mechanism were obtained by developed microscopic image processing method. It was found that the microstructure of W/O waxy crude oil emulsion has the evolution of “individual structure--homogeneous aggregate structure--heterogeneous coaggregate structure--floc structure” during the static cooling, which results in the four stages during gelation process. Different from previous studies, the aggregation of emulsified water droplets was found to be more significant and contributes to the formation and development of the wax crystals-emulsified water droplets coaggregate, which plays a decisive role in the further evolution of the gelled microstructure. Time series microscopic images show the dynamic aggregation of emulsified water droplets and wax crystals. Two different aggregation behaviours between wax crystals and water droplets were observed. That wax crystals can not only embed in gaps between adjacent water droplets and enhance the structure, but also surround the outside of the water droplets and continue to grow resulting in the interconnection of different coaggregates to form a larger floc structure. In addition, correlation between viscoelasticity and microstructure evolution of waxy crude oil emulsions of different water contents was discussed. With increasing water contents, the microstructure is changed from wax crystal flocculation structure as the main skeleton and the emulsified water droplets embedded in it, into the aggregation of emulsified water droplets occupying the main position. When the number of wax crystals and water droplets reaches a certain ratio, did wax crystals form coaggregates with emulsified water droplets, and the remaining wax crystals formed an overall flocculation structure, the viscoelasticity of the waxy crude oil emulsion is the highest.
基金supported by the National Natural Science Foundation of China(52104064)(52074089)the China Postdoctoral Science Foundation(2020M681074)+3 种基金Heilongjiang Provincial Natural Science Foundation of China(YQ2023E006)University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(UNPYSCT-2020152)Postdoctoral Science Foundation of Heilongjiang Province in China(LBH-TZ2106)(LBH-Z20122)Northeast Petroleum University Talents Introduction Fund(2019KQ18).
文摘With the increasing oil demand, the construction of oil energy reserves in China needs to be further strengthened. However, given that there has been no research on the main influencing factors of crude oil temperature drop in storage tanks under actual dynamically changing environments, this paper considers the influence of dynamic thermal environment and internal crude oil physical properties on the fluctuating changes in crude oil temperature. A theoretical model of the unsteady-state temperature drop heat transfer process is developed from a three-dimensional perspective. According to the temperature drop variation law of crude oil storage tank under the coupling effect of various heat transfer modes such as external forced convection, thermal radiation, and internal natural convection, the external dynamic thermal environment influence zone, the internal crude oil physical property influence zone, and the intermediate transition zone of the tank are proposed. And the multiple non-linear regression method is used to quantitatively characterize the influence of external ambient temperature, solar radiation, wind speed, internal crude oil density, viscosity, and specific heat capacity on the temperature drop of crude oil in each influencing zone. The results of this paper not only quantitatively explain the main influencing factors of the oil temperature drop in the top, wall, and bottom regions of the tank, but also provide a theoretical reference for oil security reserves under a dynamic thermal environment.
基金supported by the National Natural Science Foundation of China (Nos. 50971056 and 51171057)the Youth Natural Science Foundation of Hebei Province (No. E2011202002)
文摘The variations of magnetization and magnetostriction with temperature and stress were investigated through the analysis of the effective field,induced by temperature and stress.A nonlinear magnetostrictive model of giant magnetostrictive materials was proposed.The proposed model can be used to calculate the magnetostrictive characterization of giant magnetostrictive materials in different temperatures and under different stresses.The coupling effects of axial stress,magnetic field,and temperature on the magnetostriction of a Terfenol-D rod were numerically simulated as well as experimentally tested.Comparison between the calculating and experimental results shows that the proposed model can better describe the magneto-thermo-mechanical characteristics of Terfenol-D rod under different temperatures and compressive stress.Therefore,the proposed model possesses an important significance for the design of magnetostrictive devices.
基金Supported by Natural Science Foundation of Shandong Province,No.ZR2013HM004
文摘AIM: To assess the effectiveness of endoscopic fullthickness resection(EFR) and laparoscopic surgery in the treatment of gastric stromal tumors arising from the muscularis propria.METHODS: Out of 62 gastric stromal tumors arising from the muscularis propria, each > 1.5 cm in diameter, 32 were removed by EFR, and 30 were removed by laparoscopic surgery. The tumor expression of CD34, CD117, Dog-1, S-100, and SMA was assessed immunohistochemically. The operative time, complete resection rate, length of hospital stay, incidence of complications, and recurrence rate were compared between the two groups. Continuous data were compared using in-dependent samples t-tests, and categorical data were compared using χ2 tests.RESULTS: The 32 gastric stromal tumors treated by EFR and the 30 treated by laparoscopic surgery showed similar operative time [20-155 min(mean, 78.5 ± 30.1 min) vs 50-120 min(mean, 80.9 ± 46.7 min), P > 0.05], complete resection rate(100% vs 93.3%, P > 0.05), and length of hospital stay [4-10 d(mean, 5.9 ± 1.4 d) vs 4-19 d(mean, 8.9 ± 3.2 d), P >0.05]. None of the patients treated by EFR experienced complications, whereas two patients treated by laparoscopy required a conversion to laparotomy, and one patient had postoperative gastroparesis. No recurrences were observed in either group. Immunohistochemical staining showed that of the 62 gastric stromal tumors diagnosed by gastroscopy and endoscopic ultrasound, six were leiomyomas(SMA-positive), one was a schwannoglioma(S-100 positive), and the remaining 55 were stromal tumors.CONCLUSION: Some gastric stromal tumors arising from the muscularis propria can be completely removed by EFR. EFR could likely replace surgical or laparoscopic procedures for the removal of gastric stromal tumors.
基金grants from the Natural Science Foundation of Hubei Province,China(No 2016CFB619)Clinical Research Physician Program of Tongji Medical College,HUST(No.5001540017).
文摘The aim of this review was to systematically compare the outcomes of enhanced recovery after surgery(ERAS)with standard care(SC)after radical cystectomy.We performed a systematic search of PubMed,Ovid?Web of Science,and the Cochrane Library to identify studies published until September 2017 which involved a comparison of ERAS and SC.A meta-analysis was performed to assess the outcomes of ERAS versus SC.Sixteen studies including 8 prospective and 8 retrospective trials met the eligibility criteria.A total of 2100 participants were assigned to ERAS(1258 cases)or SC(842 cases).The time to first flatus passage[WMD=-0.95 days,95%Cl(-1.50,-0.41),P=0.0006],time until return to a regular diet[WMD=-2.15 days,95%Cl(-2.86,—1.45),P<0.00001]and the length of hospital stay[WMD=-3.75 days,95%Cl(-5.13,-2.36),P<0.00001]were significantly shorter,and the incidence of postoperative complications[OR=0.60,95%Cl(0.44,0.83),P=0.002],especially postoperative paralytic ileus[OR=0.43,95%Cl(0.30,0.62),P<0.00001]and cardiovascular complications[OR=0.28,95%Cl(0.09,0.90),P=0.03]was significantly lower in the ERAS group than those in the SC group.This meta-analysis demonstrated that ERAS was associated with a shorter time to first flatus passage,return of bowel fimction,and the length of hospital stay than SC in patients undergoing radical cystectomy,as well as a lower rate of postoperative complications,especially paralytic ileus and cardiovascular complications.
基金supported by the National Natural Science Foundation of China(Nos.90813015,20935002)
文摘Monolithic silica spin column extraction(MonoSpin-SPE)was developed as a simple,sensitive,and eco-friendly pretreatment method which combined with ultra-fast liquid chromatography-mass spectrometry(UFLC-MS)to determine the levels of six phthalate esters,dimethyl-(DMP),diethyl-(DEP),dipropyl-[DPrP],butyl-benzyl-(BBP),dicyclohexyl-(DcHP),and di-n-octyl-(DOP)phthalate in physiological saline samples.Under optimized experimental conditions,the method was linear in the following ranges:0.2-50 μg/L for DMP,DEP,DPrP,DcHP and DOP;5-100 μg/L for BBP.The correlation coefficients(R2)were in the range of 0.9951-0.9995 for all the analytes and the limits of detection(LODs)and limits of quantification(LOQs)were in the ranges of 0.02-0.9 μg/L and 0.08-2.7 μg/L,respectively.The pretreatment process showed good reproducibility with inter-day and intra-day relative standard deviations(RSDs)below 8.5% and 11.2%,respectively.This method was used to determine the levels of six phthalate esters in physiological saline samples and the recoveries ranged from 71.2% to 107.3%.DMP and DEP were found in actual physical saline samples(brand A and brand B).
基金Supported by the Key Project of Scientific and Technological Innovation in Hangzhou,NO.20131813A08the Key Project of Medical Scientific and Technology Program in Hangzhou,NO.2013Z04+1 种基金the Traditional Chinese Medical Science Research Program of Zhejiang Province,NO.2018239534the Applied Research Project of Commonweal Technology in Zhejiang Province,NO.2017C33180
文摘Primary hyperparathyroidism(PHPT) is rare during pregnancy. A case of twin pregnancy with three simultaneous parathyroid adenomas at the same time has not been reported. Multiple parathyroid lesions are difficult to diagnose, as pregnant women who insist upon continuing a pregnancy are not able to undergo 99mTc-sestamibi scintigraphy, so cases of PHPT are easily unobserved and often can have serious consequences for the patient and the fetus. Therefore, we reported a case of a 28-year-old woman mid-pregnancy with twins, who had hypercalcemia and was eventually diagnosed with twin pregnancy with PHPT due to a triple parathyroid adenoma, had good pregnancy outcomes after undergoing surgery in mid-pregnancy. Twin pregnancy with PHPT due to a triple parathyroid adenoma, as presented in this case, is very rare and surgery in mid-pregnancy is demonstrated here as safe. Intraoperative parathormone monitoring was and remains key to a successful operation.
基金supported by the National Natural Science Foundation of China,No.81771422(to ZY)
文摘Certain microRNAs(miRNAs)can function as neuroprotective factors after reperfusion/ischemia brain injury.miRNA-142-3p can participate in the occurrence and development of tumors and myocardial ischemic injury by negatively regulating the activity of Rac1,but it remains unclear whether miRNA-142-3p also participates in cerebral ischemia/reperfusion injury.In this study,a model of oxygen-glucose deprivation/re-oxygenation in primary cortical neurons was established and the neurons were transfected with miR-142-3p agomirs or miR-142-3p antagomirs.miR-142-3p expression was down-regulated in neurons when exposed to oxygen-glucose deprivation/re-oxygenation.Over-expression of miR-142-3p using its agomir remarkably promoted cell death and apoptosis induced by oxygen-glucose deprivation/re-oxygenation and improved mitochondrial biogenesis and function,including the expression of peroxisome proliferator-activated receptor-γcoactivator-1α,mitochondrial transcription factor A,and nuclear respiratory factor 1.However,the opposite effects were produced if miR-142-3p was inhibited.Luciferase reporter assays verified that Rac Family Small GTPase 1(Rac1)was a target gene of miR-142-3p.Over-expressed miR-142-3p inhibited NOX2 activity and expression of Rac1 and Rac1-GTPase(its activated form).miR-142-3p antagomirs had opposite effects after oxygen-glucose deprivation/re-oxygenation.Our results indicate that miR-142-3p down-regulates the expression and activation of Rac1,regulates mitochondrial biogenesis and function,and inhibits oxygen-glucose deprivation damage,thus exerting a neuroprotective effect.The experiments were approved by the Committee of Experimental Animal Use and Care of Central South University,China(approval No.201703346)on March 7,2017.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11573063 and 11611530685)the Key Science Foundation of Yunnan Province (Grant No. 2017FA001)+1 种基金CAS “Light of West China” ProgramCAS Interdisciplinary Innovation Team
文摘The lander of China’s Chang’E-3 spacecraft is equipped with a 15-cm telescope that is very useful for monitoring celestial objects in the ultraviolet(UV) band(245–340 nm).The Lunar-based Ultraviolet Telescope(LUT) is the first long-term lunar-based astronomical observatory,that can make uninterrupted observations of a target from the Moon.Here we present the continuous complete UV light curve of the eclipsing binary TX Herculis(TX Her).The analysis of the light curve suggests that TX Her is a detached binary.The dip in the light curve was explained by the emergence of a stellar dark spot on the less massive F0 type component.The cyclic change of arrival eclipse times for the system reveals that it contains an additional stellar companion with a minimal mass of 0.35 M⊙ and a period of 48.92 yr,which is supported by the detected light contribution of the third body from light curve analysis.This third body may play an important role in the formation of the present short-period system TX Her.
基金financially supported by the National Natural Science Foundation of China (Grant No.52174060)the PetroChina Innovation Foundation (Grant No.2019D-5007-0501)The Postdoctoral Scientific Foundation of Heilongjiang Province in China (Grant No. LBH-Q20012)。
文摘Foaming issues are encountered at the stages in crude oil production, transportation, processing, especially in chemical flooding enhanced oil recovery(EOR) oilfields. These accumulated foams would cause a lot of trouble for downstream operation. The destruction of foams under ultrasonic has been increasingly paying attention in the background of green oilfield development. This study focuses on the decay kinetic characteristics of alkaline-surfactant-polymer-strengthened foams under the ultrasonic standing wave.The performance of the diverse foams was characterized. A decay kinetic model incorporating the energy correlation was developed and validated. The factors that affect the decay kinetic characteristics were discussed. The results indicated that the collapse rate and the collapse volume fraction decreased when the foam size decreased, the gas-liquid ratio decreased and the surface tension increased. Ultrasonic standing wave parameters have a significant impact on the decay behavior of the foam. Both the ultrasonic frequency and ultrasonic amplitude were increased by 50%, the collapse volume fraction of foams increased by about 1.25 times in the identical irradiation time. The relative deviation between the measured results and the model prediction was less than 10%. The potential collapse mechanism was also explained using the principle of energy correlation of foam surface. This study is not only beneficial to provide a robust and rigorous way to defoam of produced liquid in the alkaline/surfactant/polymer(ASP)flooding EOR process but also meaningful to well understand the decay process of oil-based foams.
基金partly supported by the National Natural Science Foundation of China (Nos. 11573063 and 11611530685)the Key Science Foundation of Yunnan Province (No. 2017FA001)the CAS “Light of West China” Program and the CAS Interdisciplinary Innovation Team
文摘TZ Eri and TU Her are both classic Algol-type systems(Algols). By observing and collecting times of minimum light, we constructed the O-C curves for the two systems. The long-time upward and downward parabolas shown in these diagrams are considered to be the result of the combination of mass transfer and angular momentum loss. The secular orbital period change rates are d P/dt = 4.74(±0.12) ×10-7 d yr-1 and d P/dt =-2.33(±0.01) × 10-6 d yr-1, respectively. There are also cyclic variations in their O-C curves which might be caused by the light-travel time effect(LTTE). A circumbinary star may exist in the TZ Eri system with a mass of at least 1.34 M⊙, while there are possibly two celestial bodies that almost follow a 2 : 1 resonance orbit around the TU Her binary pair. Their masses are at least 2.43 M⊙and 1.27 M⊙.
基金supported by the National Natural Science Foundation of China (No. 11573063)the Key Science Foundation of Yunnan Province (No. 2017FA001)+1 种基金CAS “Light of West China” ProgramCAS Interdisciplinary Innovation Team
文摘NSVS 14256825 is the second discovered sdOB+dM eclipsing-binary system with an orbital period of 2.65 h. This special binary was reported to contain circumbinary planets or brown dwarfs by using the timing method. However, different results were derived by different authors because of the insufficient coverage of eclipse timings. Since 2008, we have monitored this binary for about 10 yr using several telescopes and 84 new times of light minimum were obtained with high precision. It is found that the O-C curve has been increasing recently and it shows a cyclic variation with a period of 8.83 yr and an amplitude of 46.31 seconds. The cyclic change cannot be explained by magnetic activity cycles of the red dwarf component because the required energy is much larger than that radiated by this component in one whole period. This cyclic change detected in NSVS 14256825 could be explained by the light-travel time effect via the presence of a third body. The lowest mass of the third body is determined to be 14.15 Mjupwhich is in the transition range between planets and brown dwarfs. The substellar object is orbiting around this evolved binary at an orbital separation of around 3 AU with an eccentricity of 0.12. These results indicate that NSVS 14256825 is the first sdOB-type eclipsing binary consisting of a hierarchical substellar object.The detection of a close-in substellar companion to NSVS 14256825 will provide some insights on the formation and evolution of sdOB-type binaries and their companions.
基金supported by the Key Foundation of Wuhan Huoshenshan Hospital (2020 [18])Key Research&Development Program of Jiangsu Province (BE2018713)+3 种基金Medical Innovation Project of Logistics Service (18JS005)the Foundation of Jiangsu Population Association (JSPA2019017)Medical Science and Technology Development FoundationNanjing Department of Health (YKK18179)。
文摘Background: Gastrointestinal symptoms are not rare among coronavirus disease 2019(COVID-19) patients, but there have been no reports regarding convalescent plasma therapy for the recovery of gastrointestinal problems in COVID-19 patients.Case presentation: We present two cases of patients with COVID-19-associated recurrent diarrhea and positive fecal occult blood who successfully recovered after a one-time convalescent plasma administration.Conclusion: When COVID-19 patients develop recurrent or refractory gastrointestinal symptoms and fail to respond to the available treatment, alternative therapy with convalescent plasma administration may be considered.
基金supported by the National Natural Science Foundation of China (81670160,82070175,81800198,81600183,81700168)the Natural Science Foundation of Changsha Municipal (kq2014234)。
文摘Targeting immune checkpoints has achieved great therapeutic effects in the treatment of early-stage tumors.However,most patients develop adaptive resistance to this therapy.The latest evidence demonstrates that tumorderived exosomes may play a key role in systemic immune suppression and tumor progression.In this article,we highlight the role of exosomal immune checkpoint proteins in tumor immunity,with an emphasis on programmed death ligand 1(PD-L1) and cytotoxic T lymphocyte-associated antigen 4(CTLA-4),as well as emerging evidence on roles of T cell immunoglobulin-3(TIM-3),arginase 1(ARG1),and estrogen receptor binding fragment-associated antigen 9(EBAG9) expressed by exosomes.
基金the National Natural Science Foundation of China(Grant No.11922306)the Key Science Foundation of Yunnan Province(Grant No.2017FA001)the CAS Interdisciplinary Innovation Team。
文摘The new complete BV Rc Ic light curves and spectra of the short-period eclipsing binary XZ CMi are presented.The results from the combined analysis based on the photometric and spectroscopic data show that XZ CMi is a near contact binary with the secondary component filling its critical Roche lobe while the primary filling 91%of its Roche lobe.The investigation of the O-C diagram reveals that its orbital period is continuously increasing,which is consistent with the derived configuration and caused by the mass transfer from the less massive star to the more massive one.In addition,an obvious periodic modulation with the amplitude of0.0187(±0.0016)d and a high eccentric of 0.86(±0.04)is detected,which could be the results of the light time effect as a third star with the mass no less than 0.42(±0.09)M⊙orbiting around the central eclipsing binary once every 95.7(±2.1)yr.Furthermore,we found a visual companion star at 2.4′′east by south of this system at a much greater distance by direct image.The large third light contribution found from the light curve analysis could be well explained by the existence of the third star and the fourth visual one.The similar parallax and proper motion imply that the components of this hierarchical quadruple system might be bounded by gravitation.Spectroscopic observations for two visual components were carried out by the LAMOST and 2.16 m telescopes,respectively.Their different values of[Fe/H]suggest that they were not born from the same origin.Thus,XZ CMi system is an interesting and important target to study the formation of the multiple stars.
基金National Key Research and Development Project(2018YFA0707300)National Natural Science Foundation of China(52205404)Fundamental Research Program of Shanxi Province(202203021212293).
文摘A variable mass tuned particle absorber is designed for the nonlinear vertical vibration control of the corrugated rolling mill in the composite plate rolling process.Considering the nonlinear damping and nonlinear stiffness between the corrugated interface,a three-degree-of-freedom nonlinear vertical vibration mathematical model of corrugated rolling mill based on dynamic vibration absorber control is established.The multi-scale method is used to solve the amplitude–frequency characteristic curve equation of the installed dynamic vibration absorber(DVA)system.The effects of stiffness coefficient and damping coefficient on the amplitude–frequency characteristic curve are analyzed.The expressions of the dynamic developed factor of the corrugated roll are derived,and the influence laws of mass ratio,frequency ratio and damping ratio on the dynamic amplification factor are analyzed.The optimal parameters of the DVA are obtained by adaptive genetic algorithm.The control effect of the DVA on the nonlinear vertical vibration is studied by numerical simulation.The feasibility of the designed dynamic absorber is verified through experiments.The results show that the designed dynamic absorber can effectively suppress the vertical vibration of the corrugated roller.
基金financially supported by the National Natural Science Foundation of China(Nos.91016013 and 11221202)the Opening Research Fund of State Key Laboratory of Porous Metal Materials(No.PMM-SKL-1-2012)the Project of State Key Laboratory of Explosion Science and Technology(No.SKLEST-13-07)
文摘The hot deformation behavior of TC18 alloy at strain rates ranging from 1 9 10-4to 1 9 10-2s-1and temperatures ranging from 25 to 800 °C was studied using a WDW-300 electronic universal testing machine. The relationships between true stress and true strain show that flow stress decreases with the increase of temperature and increases as strain rate increases. The effect of strain rate on the flow stress becomes pronounced at higher temperatures. At room temperature, the river pattern characteristic of brittle fracture and the dimple pattern typical of ductile fracture are found to exist in different regions of fracture surfaces of the samples. An improved constitutive relationship is proposed to accurately describe the flow stress of TC18 by considering the effect of strain. And a microscopic model is also deduced which can link the physical mechanisms to the macroscopic experimental results. A good agreement is obtained between the predictions of the microscopic model and the results of the macroscopic experiment.