Hot compression tests in the temperature range of 340-450 ℃ and strain rate range of 0.001-1 s^-1 of spray-formed 7055 aluminum alloy were carried out to study its hot deformation behavior. Three phenomenological mod...Hot compression tests in the temperature range of 340-450 ℃ and strain rate range of 0.001-1 s^-1 of spray-formed 7055 aluminum alloy were carried out to study its hot deformation behavior. Three phenomenological models including Johnson-Cook, modified Fields-Backofen and Arrhenius-type were introduced to predict the flow stresses during the compression process. And then, a comparative predictability of the phenomenological models was estimated in terms of the relative errors, correlation coefficient（R）, and average absolute relative error（AARE）. The results indicate that Johnson-Cook model and modified Fields-Backofen model cannot well predict the hot deformation behavior due to the large deviation in the process of line regression fitting. Arrhenius-type model obtains the best fit through combining the effect of strain rate and temperature.展开更多
A 68-year-old male was complained of chest pain for two years and fatigue for one week. He was admitted to other hospitals two years ago because of severe chest pain. A diagnosis of acute non-ST segment elevation myoc...A 68-year-old male was complained of chest pain for two years and fatigue for one week. He was admitted to other hospitals two years ago because of severe chest pain. A diagnosis of acute non-ST segment elevation myocardial infarction （NSTEMI） was made. But the coronary angiography was refused by himself. After effective conservative treatment, he got better and discharged. A regular administration of aspirin, metoprolol and simvastatin was taken. No recurrent sympotoms occurred. However, he felt fatigue and palpitation after 30-m walking one week ago without predisposing factors.展开更多
Objective: To assess the effect of curcumin on CDDP-induced drug resistance and explore the underlying molecular mechanism through Nrf2 system and autophagy pathway.Methods: A drug-resistant cell model was established...Objective: To assess the effect of curcumin on CDDP-induced drug resistance and explore the underlying molecular mechanism through Nrf2 system and autophagy pathway.Methods: A drug-resistant cell model was established by exposing A549/CDDP cell to2 μg/mL CDDP. A549/CDDP cell was treated with 20 μg/mL CDDP and 10 μM curcumin. The cell viability and apoptosis level, the signals of Keap1/P62-Nrf2 and autophagy pathway were analyzed.Results: CDDP induction promoted drug-resistant phenotype in A549/CDDP cell and activated autophagy as well as Nrf2 signals in A549/CDDP cell. Meanwhile, curcumin combination attenuated autophagy and Nrf2 activation induced by CDDP, and reversed the drug-resistant phenotype. Notably, curcumin combination augmented Keap1 transcription. Furthermore, Keap1 ablation with short hairpin RNAs hampered the efficacy of curcumin, suggesting Keap1 played a crucial role on reversal effect of curcumin.Conclusions: The present findings demonstrate that CDDP promotes abnormal activation of Nrf2 pathway and autophagy, leading to drug resistance of A549/CDDP cell.Curcumin attenuates this process and combat drug-resistance through its potent activation on Keap1 transcription, which is essential for interplay between oxidative stress induced Nrf2 activation and autophagy/apoptosis switch.展开更多
Intermuscular bones(IBs)are slender linear bones embedded in muscle,which ossify from tendons through a process of intramembranous ossification,and only exist in basal teleosts.IBs are essential for fish swimming,but ...Intermuscular bones(IBs)are slender linear bones embedded in muscle,which ossify from tendons through a process of intramembranous ossification,and only exist in basal teleosts.IBs are essential for fish swimming,but they present a choking risk during human consumption,especially in children,which can lead to commercial risks that have a negative impact on the aquaculture of these fish.In this review,we discuss the morphogenesis and functions of IBs,including their underlying molecular mechanisms,as well as the advantages and disadvantages of different methods for IB studies and techniques for breeding and generating IB-free fish lines.This review reveals that the many key genes involved in tendon development,osteoblast differentiation,and bone formation,e.g.,scxa,msxC,sost,twist,bmps,and osterix,also play roles in IB development.Thus,this paper provides useful information for the breeding of new fish strains without IBs via genome editing and artificial selection.展开更多
The novel coronavirus disease(COVID-19)pandemic is emerging as a global health threat and shows a higher risk for men than women.Thus far,the studies on andrological consequences of COVID-19 are limited.To ascertain t...The novel coronavirus disease(COVID-19)pandemic is emerging as a global health threat and shows a higher risk for men than women.Thus far,the studies on andrological consequences of COVID-19 are limited.To ascertain the consequences of COVID-19 on sperm parameters after recovery,we recruited 41 reproductive-aged male patients who had recovered from COVID-19,and analyzed their semen parameters and serum sex hormones at a median time of 56 days after hospital discharge.For longitudinal analysis,a second sampling was obtained from 22 of the 41 patients after a median time interval of 29 days from first sampling.Compared with controls who had not suffered from COVID-19,the total sperm count,sperm concentration,and percentages of motile and progressively motile spermatozoa in the patients were significantly lower at first sampling,while sperm vitality and morphology were not affected.The total sperm count,sperm concentration,and number of motile spermatozoa per ejaculate were significantly increased and the percentage of morphologically abnormal sperm was reduced at the second sampling compared with those at first in the 22 patients examined.Though there were higher prolactin and lower progesterone levels in patients at first sampling than those in controls,no significant alterations were detected for any sex hormones examined over time following COVID-19 recovery in the 22 patients.Although it should be interpreted carefully,these findings indicate an adverse but potentially reversible consequence of COVID-19 on sperm quality.展开更多
In order to measure the Universal Time(UT1)in real time,National Time Service Center(NTSC)has built a VGOS-like(VLBI Global Observing System)broadband VLBI network,which includes three13-m radio telescopes located in ...In order to measure the Universal Time(UT1)in real time,National Time Service Center(NTSC)has built a VGOS-like(VLBI Global Observing System)broadband VLBI network,which includes three13-m radio telescopes located in Jilin,Sanya and Kashi,and a data analysis center in Xi’an.Each station is equipped with a highly stable hydrogen atomic clock and a self-developed VLBI backend,and is colocated with two GPS receivers.This VGOS-like VLBI network may play an important role in improving the Chinese broadband VLBI technology and making valuable contributions to domestic VLBI measurements of UT1.In this paper,we introduce the specifications of this VLBI network,and present the UT1 measurements at C-band conducted in 2018 using the Jilin-Kashi baseline of this network.The comparisons between our UT1 estimates and those provided by IERS suggest that the NTSC VLBI network is capable to determine UT1 accurate at the level of 58.8μs.展开更多
As an emerging technology to promote the combination of medicine and industry,the three-dimensional(3D)printing has developed rapidly in the fields of orthopedics,while its unique advantages in improving precise treat...As an emerging technology to promote the combination of medicine and industry,the three-dimensional(3D)printing has developed rapidly in the fields of orthopedics,while its unique advantages in improving precise treatment still need to be further popularized.In this report,our team have exhibited several classic cases of integrating 3D printing into orthopedic clinical application,thereby further elaborating thoughts and opinions on the significance of 3D printing in the orthopedic clinical application,technical advantages,existing main problems and coping strategies.展开更多
As drilling wells continue to move into deep ultra-deep layers,the requirements for temperature resistance of drilling fluid treatments are getting higher and higher.Among them,blocking agent,as one of the key treatme...As drilling wells continue to move into deep ultra-deep layers,the requirements for temperature resistance of drilling fluid treatments are getting higher and higher.Among them,blocking agent,as one of the key treatment agents,has also become a hot spot of research.In this study,a high temperature resistant strong adsorption rigid blocking agent(QW-1)was prepared using KH570 modified silica,acrylamide(AM)and allyltrimethylammonium chloride(TMAAC).QW-1 has good thermal stability,average particle size of 1.46μm,water contact angle of 10.5.,has a strong hydrophilicity,can be well dispersed in water.The experimental results showed that when 2 wt%QW-1 was added to recipe A(4 wt%bentonite slurry+0.5 wt%DSP-1(filtration loss depressant)),the API filtration loss decreased from 7.8to 6.4 m L.After aging at 240.C,the API loss of filtration was reduced from 21 to 14 m L,which has certain performance of high temperature loss of filtration.At the same time,it is effective in sealing 80-100mesh and 100-120 mesh sand beds as well as 3 and 5μm ceramic sand discs.Under the same conditions,the blocking performance was superior to silica(5μm)and calcium carbonate(2.6μm).In addition,the mechanism of action of QW-1 was further investigated.The results show that QW-1 with amide and quaternary ammonium groups on the molecular chain can be adsorbed onto the surface of clay particles through hydrogen bonding and electrostatic interaction to form a dense blocking layer,thus preventing further intrusion of drilling fluid into the formation.展开更多
Male infertility is a worldwide health issue,affecting 8%–12%of the global population.Oligoasthenoteratozoospermia(OAT)represents a severe type of male infertility,characterized by reduced sperm count and motility an...Male infertility is a worldwide health issue,affecting 8%–12%of the global population.Oligoasthenoteratozoospermia(OAT)represents a severe type of male infertility,characterized by reduced sperm count and motility and an increased frequency of sperm with aberrant morphology.Using whole-exome sequencing,this study identified a novel missense mutation(c.848C>A,p.A283E)in the coiled-coil domain-containing 34 gene(CCDC34)in a consanguineous Pakistani family.This rare mutation was predicted to be deleterious and to affect the protein stability.Hematoxylin and eosin staining of spermatozoa from the patient with OAT revealed multiple morphological abnormalities of the flagella and transmission electron microscopy indicated axonemal ultrastructural defects with a lack of outer dynein arms.These findings indicated that CCDC34 plays a role in maintaining the axonemal ultrastructure and the assembly or stability of the outer dynein arms,thus expanding the phenotypic spectrum of CCDC34 missense mutations.展开更多
The morphology and kinematics of the spiral structure of the Milky Way are long-standing problems in astrophysics.In this review we firstly summarize various methods with different tracers used to solve this puzzle.Th...The morphology and kinematics of the spiral structure of the Milky Way are long-standing problems in astrophysics.In this review we firstly summarize various methods with different tracers used to solve this puzzle.The astrometry of Galactic sources is gradually alleviating this difficult situation caused mainly by large distance uncertainties, as we can currently obtain accurate parallaxes(a few μas) and proper motions(≈1 km s-1) by using Very Long Baseline Interferometry(VLBI).On the other hand, the Gaia mission is providing the largest, uniform sample of parallaxes for O-type stars in the entire Milky Way.Based upon the VLBI maser and Gaia O-star parallax measurements, nearby spiral structures of the Perseus, Local, Sagittarius and Scutum Arms are determined in unprecedented detail.Meanwhile, we estimate fundamental Galactic parameters of the distance to the Galactic center,R0, to be 8.35 ± 0.18 kpc, and circular rotation speed at the Sun, Θ0, to be 240±10 km s-1.We found kinematic differences between O stars and interstellar masers: the O stars, on average, rotate faster,>8 km s-1than maser-traced high-mass star forming regions.展开更多
The action potential of pacemaker cells in the sino-atrial node forms the automatic rhythm of the heart. The automatic depolarization in phase 4 is me DaSlS of the automaticity in pacemaker cells. Many currents are in...The action potential of pacemaker cells in the sino-atrial node forms the automatic rhythm of the heart. The automatic depolarization in phase 4 is me DaSlS of the automaticity in pacemaker cells. Many currents are included in phase 4, such as calcium current, TTX-sensitive sodium current, sustained inward current （Isi）, decay of delayed rectifier potassium current, etc. Funny current （If） has long been recognized as important in this phase and is activated at hyperpolarized potentials during cell diastole and in turn activates other currents to form automatic depolarization.展开更多
Brain diseases affect 1 in 6 people worldwide.These diseases range from acute neurological conditions such as stroke to chronic neurodegenerative disorders such as Alzheimer’s disease.Recent advancements in tissue-en...Brain diseases affect 1 in 6 people worldwide.These diseases range from acute neurological conditions such as stroke to chronic neurodegenerative disorders such as Alzheimer’s disease.Recent advancements in tissue-engineered brain disease models have overcome many of the different shortcomings associated with the various animal models,tissue culture models,and epidemiologic patient data that are commonly used to study brain disease.One innovative method by which to model human neurological disease is via the directed differentiation of human pluripotent stem cells(hPSCs)to neural lineages including neurons,astrocytes,and oligodendrocytes.Three-dimensional models such as brain organoids have also been derived from hPSCs,offering more physiological relevance due to their incorporation of various cell types.As such,brain organoids can better model the pathophysiology of neural diseases observed in patients.In this review,we will emphasize recent developments in hPSC-based tissue culture models of neurological disorders and how they are being used to create neural disease models.展开更多
BACKGROUND The prevalence of osteoporosis and low bone mass is steadily rising each year.Low body weight is commonly linked to diminished bone mass and serves as a robust predictor of osteoporosis.Nonetheless,the conn...BACKGROUND The prevalence of osteoporosis and low bone mass is steadily rising each year.Low body weight is commonly linked to diminished bone mass and serves as a robust predictor of osteoporosis.Nonetheless,the connection between body mass index(BMI),bone mineral density,and lipid profiles among the elderly remains elusive.AIM To examine the association between BMI and bone mass,explore the correlation between lipid profiles and bone mass,and delve into the interplay between lipid metabolism and bone health.METHODS The study included 520 patients aged≥65 years(178 men and 342 women).Age,sex,weight,and height were recorded.Femoral neck bone mineral density and T scores were determined using a dual-energy X-ray absorptiometry scanner.Blood calcium(Ca),phosphorus(P),albumin(ALB),alkaline phosphatase(ALP),aspartate aminotransferase,alanine aminotransferase,triglyceride(TG),total cholesterol(TC),high-density lipoprotein(HDL)and low-density lipoprotein(LDL)levels were measured.Patients were classified by sex(male and female),age(65-79 years and≥80 years),and T score(normal bone mineral density,osteopenia and osteoporosis).RESULTS Age,sex,BMI,and ALP and TG levels were independent risk factors for osteoporosis.For the 65-79-and≥80-yearold groups,females presented lower T scores than males.Ca,P,ALB,ALP,TC,HDL and LDL levels were significantly different between men and women in the 65-79-year-old group.In addition,BMI and TG levels were significantly decreased in osteoporotic patients compared with patients with normal bone mass.TC levels declined in 65-to 79-year-old male and female osteoporosis patients.In the group of women aged≥80 years,osteoporotic patients showed significantly increased ALP levels.Furthermore,we found positive correlations between BMI and TG levels in the male and female patient groups.However,we found no significant differences in ALB,Ca,P,HDL and LDL levels in osteoporotic patients compared to patients with normal bone mass.CONCLUSION Osteoporotic patients showed significantly decreased 展开更多
In order to explore a novel and potential method using carbon nanotubes （CNTs） for controlling blue-green algal blooms efficiently in future, effects of single-walled carbon nanotubes （SWCNTs） on Microcystis aerug...In order to explore a novel and potential method using carbon nanotubes （CNTs） for controlling blue-green algal blooms efficiently in future, effects of single-walled carbon nanotubes （SWCNTs） on Microcystis aeruginosa growth control were investigated under lab cultured conditions. Related physiological changes were tested involving several important enzyme of antioxidant defense system （superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT）, malondiadehyde （MDA）, photosynthetic pigments, protein, soluble sugar and extracellular microcystin toxins （MC-LR））. Algal cell density was significantly inhibited by SWCNTs at high concentration （〉5.00 mg/L）, and the inhibition rate was dose-dependent. For treatment with 100 mg/L SWCNTs, the inhibitory rates even reached above 90%. 96 h IC50 was determined as 22 mg/L. Antioxidant enzyme activities were dramatically dropped with increasing lipid peroxidation at higher SWCNTs concentration, indicating intracellular generation of reactive oxygen species （ROS） and oxidative stress damage in algae. Reduction of photosynthetic pigments, soluble sugar and protein contents suggested that SWCNTs may severely ruin algal photosynthesis system, destroy the metabolism-related structure of cell, and thus lead to negative physiological status in M. aeruginosa. Besides, SWCNTs can effectively decrease the amount of extracellular microcystins in culture medium.展开更多
Recent advances in monochromatic aberration corrected electron microscopy make it possible to detect the lattice vibrations with both high-energy resolution and high spatial resolution. Here, we use sub-10 meV electro...Recent advances in monochromatic aberration corrected electron microscopy make it possible to detect the lattice vibrations with both high-energy resolution and high spatial resolution. Here, we use sub-10 meV electron energy loss spectroscopy to investigate the local vibrational properties of the SiO_2/Si surface and interface. The energy of the surface mode is thickness dependent, showing a blue shift as z-thickness(parallel to the fast electron beam)of SiO_2 film increases, while the energy of the bulk mode and the interface mode keeps constant. The intensity of the surface mode is well-described by a Bessel function of the second kind. The mechanism of the observed spatially dependent vibrational behavior is discussed and compared with dielectric response theory analysis. Our nanometer scale measurements provide useful information on the bonding conditions at the surface and interface.展开更多
Multiple morphological abnormalities of the sperm flagella(MMAF)is a specific type of asthenoteratozoospermia,presenting with multiple morphological anomalies in spermatozoa,such as absent,bent,coiled,short,or irregul...Multiple morphological abnormalities of the sperm flagella(MMAF)is a specific type of asthenoteratozoospermia,presenting with multiple morphological anomalies in spermatozoa,such as absent,bent,coiled,short,or irregular caliber flagella.Previous genetic studies revealed pathogenic mutations in genes encoding cilia and flagella-associated proteins(CFAPs;e.g.,CFAP43,CFAP44,CFAP65,CFAP69,CFAP70,and CFAP251)responsible for the MMAF phenotype in infertile men from different ethnic groups.However,none of them have been identified in infertile Pakistani males with MMAF.In the current study,two Pakistani families with MMAF patients were recruited.Whole-exome sequencing(WES)of patients and their parents was performed.WES analysis reflected novel biallelic loss-of-function mutations in CFAP43 in both families(Family 1:ENST00000357060.3,p.Arg300Lysfs*22 and p.Thr526Serfs*43 in a compound heterozygous state;Family 2:ENST00000357060.3,p.Thr526Serfs*43 in a homozygous state).Sanger sequencing further confirmed that these mutations were segregated recessively in the families with the MMAF phenotype.Semiquantitative reverse-transcriptase polymerase chain reaction(qRT-PCR)was carried out to detect the effect of the mutation on mRNA of the affected gene.Previous research demonstrated that biallelic loss-of-function mutations in CFAP43 accounted for the majority of all CFAP43-mutant MMAF patients.To the best of our knowledge,this is the first study to report CFAP43 biallelic loss-of-function mutations in a Pakistani population with the MMAF phenotype.This study will help researchers and clinicians to understand the genetic etiology of MMAF better.展开更多
Background： Since the 1980s, severity of illness scoring systems has gained increasing popularity in Intensive Care Units （ICUs）. Physicians used them for predicting mortality and assessing illness severity in clin...Background： Since the 1980s, severity of illness scoring systems has gained increasing popularity in Intensive Care Units （ICUs）. Physicians used them for predicting mortality and assessing illness severity in clinical trials. The objective of this study was to assess the performance of Simplified Acute Physiology Score 3 （SAPS 3） and its customized equation for Australasia （Australasia SAPS 3, SAPS 3 [AUS]） in predicting clinical prognosis and hospital mortality in emergency ICU （EICU）. Methods： A retrospective analysis of the EICU including 463 patients was conducted between January 2013 and December 2015 in the EICU of Peking University Third Hospital. The worst physiological data of enrolled patients were collected within 24 h after admission to calculate SAPS 3 score and predicted mortality by regression equation. Discrimination between survivals and deaths was assessed by the area under the receiver operator characteristic curve （AUC）. Calibration was evaluated by Hosmer-Lemeshow goodness-of fit test through calculating the ratio of observed-to-expected numbers of deaths which is known as the standardized mortality ratio （SMR）. Results： A total of 463 patients were enrolled in the study, and the observed hospital mortality was 26.1% （121/463）. The patients enrolled were divided into survivors and nonsurvivors. Age, SAPS 3 score, Acute Physiology and Chronic Health Evaluation Score 11 （APACHE 11）, and predicted mortality were significantly higher in nonsurvivors than survivors （P 〈 0.05 or P 〈 0.01 ）. The AUC （95% confidence intervals [C/s]） for SAPS 3 score was 0.836 （0.796-0.876）. The maximum of Youden＇s index, cutoff, sensitivity, and specificity of SAPS 3 score were 0.526%, 70.5 points, 66.9%, and 85.7%, respectively. The Hosmer-Lemeshow goodness-of-fit test for SAPS 3 demonstrated a Chi-square test score of 10.25, P = 0.33, SMR （95% CI） = 0.63 （0.52 0.76）. The Hosmer-Lemeshow goodness-of fit test tbr SAPS 3 （AUS） demonstrated a Chi-squa展开更多
Two new polyhydroxysteroids, 12β,16β,20-trihydroxycholesta-1,4-dien-3-one 16-acetate（1） and 24- methyl-12β,16β,20-trihydroxycholesta-1,4-dien-3-one（2） were isolated from octocoral Sinularia sp. Their structure...Two new polyhydroxysteroids, 12β,16β,20-trihydroxycholesta-1,4-dien-3-one 16-acetate（1） and 24- methyl-12β,16β,20-trihydroxycholesta-1,4-dien-3-one（2） were isolated from octocoral Sinularia sp. Their structures were elucidated primarily on the basis of 1D and 2D NMR and the mass spectroscopic studies. The cytotoxicity of these compounds against three tumor cell lines was also reported.展开更多
Ordered porous block copolymer films（PBCFs） have attracted much attention because of their potential applications in several fields. In this paper, we first reported a non-destructive, controllable, and efficient ap...Ordered porous block copolymer films（PBCFs） have attracted much attention because of their potential applications in several fields. In this paper, we first reported a non-destructive, controllable, and efficient approach for preparation of β-cyclodextrin（β-CD）-functionalized PBCFs（β-CD-PBCFs）. The key point of the approach is to incorporate β-CD units into the hydrophilic segment of amphiphilic block copolymers before the preparation of films. β-CD-PBCFs with structural integrity and controllable pore parameters were fabricated through combining of self-assembly and breath figure methods. And then, the effective adsorption capacity of β-CD-PBCFs toward Congo red was confirmed through UV-Vis spectroscopy and was found to be affected by β-CD content and solution p H values. Adsorption kinetic results showed that the adsorption behavior of β-CD-PBCFs was consistent with the pseudo-second-order kinetic model and the chemisorption mechanism.展开更多
Lower hybrid current drive(LHCD)experiments have been done on the superconducting Tokamak HT-7 by using a new developed long pulse megawatt lower hybrid wave system.An LHCD efficiency of 0.5×10^(19)A·m^(-2)/...Lower hybrid current drive(LHCD)experiments have been done on the superconducting Tokamak HT-7 by using a new developed long pulse megawatt lower hybrid wave system.An LHCD efficiency of 0.5×10^(19)A·m^(-2)/W in a pulse length of several hundreds of milliseconds has been achieved.After boronization of the tokamak vacuum vessel,considerable improvements of plasma energy confinement and particle confinement during LHCD phase have been achieved by adjusting wave spectra.An energy transfer from the lower hybrid wave to plasma bulk electrons has been demonstrated experimentally.A computer simulation of the LHCD experiments by using a ray tracing code combined with a two dimensional Fokker-Planck code is in good accordance with experimental measurements and suggests an important role of plasma current profile.展开更多
基金Project(2013HH100055) supported by the Basic Research and Science and Technology Innovation Fund of Foshan City,China
文摘Hot compression tests in the temperature range of 340-450 ℃ and strain rate range of 0.001-1 s^-1 of spray-formed 7055 aluminum alloy were carried out to study its hot deformation behavior. Three phenomenological models including Johnson-Cook, modified Fields-Backofen and Arrhenius-type were introduced to predict the flow stresses during the compression process. And then, a comparative predictability of the phenomenological models was estimated in terms of the relative errors, correlation coefficient（R）, and average absolute relative error（AARE）. The results indicate that Johnson-Cook model and modified Fields-Backofen model cannot well predict the hot deformation behavior due to the large deviation in the process of line regression fitting. Arrhenius-type model obtains the best fit through combining the effect of strain rate and temperature.
文摘A 68-year-old male was complained of chest pain for two years and fatigue for one week. He was admitted to other hospitals two years ago because of severe chest pain. A diagnosis of acute non-ST segment elevation myocardial infarction （NSTEMI） was made. But the coronary angiography was refused by himself. After effective conservative treatment, he got better and discharged. A regular administration of aspirin, metoprolol and simvastatin was taken. No recurrent sympotoms occurred. However, he felt fatigue and palpitation after 30-m walking one week ago without predisposing factors.
基金supported by the National Natural Science Foundation of China(81272485,81503236,81641141)the Natural Science Foundation of Anhui Province,China(1608085QH212)+1 种基金the Key Scientific Research Foundation of the Higher Education Institutions of Anhui Province(KJ2015A155)Key Projects of Anhui Province University Outstanding Youth Talent Supporting Program(gxyqZD2016178,gxyqZD2016179)
文摘Objective: To assess the effect of curcumin on CDDP-induced drug resistance and explore the underlying molecular mechanism through Nrf2 system and autophagy pathway.Methods: A drug-resistant cell model was established by exposing A549/CDDP cell to2 μg/mL CDDP. A549/CDDP cell was treated with 20 μg/mL CDDP and 10 μM curcumin. The cell viability and apoptosis level, the signals of Keap1/P62-Nrf2 and autophagy pathway were analyzed.Results: CDDP induction promoted drug-resistant phenotype in A549/CDDP cell and activated autophagy as well as Nrf2 signals in A549/CDDP cell. Meanwhile, curcumin combination attenuated autophagy and Nrf2 activation induced by CDDP, and reversed the drug-resistant phenotype. Notably, curcumin combination augmented Keap1 transcription. Furthermore, Keap1 ablation with short hairpin RNAs hampered the efficacy of curcumin, suggesting Keap1 played a crucial role on reversal effect of curcumin.Conclusions: The present findings demonstrate that CDDP promotes abnormal activation of Nrf2 pathway and autophagy, leading to drug resistance of A549/CDDP cell.Curcumin attenuates this process and combat drug-resistance through its potent activation on Keap1 transcription, which is essential for interplay between oxidative stress induced Nrf2 activation and autophagy/apoptosis switch.
基金This work was supported by the National Natural Science Foundation of China(U1702233 and U1902202)Program of the Chinese Academy of Sciences(XDA24030505 and XDA23080502)Program of Yunnan Provincial Science and Technology Department(202003AD150017 and 2018FY001-007)。
文摘Intermuscular bones(IBs)are slender linear bones embedded in muscle,which ossify from tendons through a process of intramembranous ossification,and only exist in basal teleosts.IBs are essential for fish swimming,but they present a choking risk during human consumption,especially in children,which can lead to commercial risks that have a negative impact on the aquaculture of these fish.In this review,we discuss the morphogenesis and functions of IBs,including their underlying molecular mechanisms,as well as the advantages and disadvantages of different methods for IB studies and techniques for breeding and generating IB-free fish lines.This review reveals that the many key genes involved in tendon development,osteoblast differentiation,and bone formation,e.g.,scxa,msxC,sost,twist,bmps,and osterix,also play roles in IB development.Thus,this paper provides useful information for the breeding of new fish strains without IBs via genome editing and artificial selection.
基金the National Key Research and Developmental Program of China(No.2018YFC1003900,2019YFA0802600,and 2018YFC1004700)a COVID-19 special task grant supported by the Chinese Academy of Science Clinical Research Hospital in Hefei(No.YD2070002020)the Fundamental Research Funds for the Central Universities(No.YD2070002006,YD9110004001,and YD9110002002).
文摘The novel coronavirus disease(COVID-19)pandemic is emerging as a global health threat and shows a higher risk for men than women.Thus far,the studies on andrological consequences of COVID-19 are limited.To ascertain the consequences of COVID-19 on sperm parameters after recovery,we recruited 41 reproductive-aged male patients who had recovered from COVID-19,and analyzed their semen parameters and serum sex hormones at a median time of 56 days after hospital discharge.For longitudinal analysis,a second sampling was obtained from 22 of the 41 patients after a median time interval of 29 days from first sampling.Compared with controls who had not suffered from COVID-19,the total sperm count,sperm concentration,and percentages of motile and progressively motile spermatozoa in the patients were significantly lower at first sampling,while sperm vitality and morphology were not affected.The total sperm count,sperm concentration,and number of motile spermatozoa per ejaculate were significantly increased and the percentage of morphologically abnormal sperm was reduced at the second sampling compared with those at first in the 22 patients examined.Though there were higher prolactin and lower progesterone levels in patients at first sampling than those in controls,no significant alterations were detected for any sex hormones examined over time following COVID-19 recovery in the 22 patients.Although it should be interpreted carefully,these findings indicate an adverse but potentially reversible consequence of COVID-19 on sperm quality.
基金supported by the National Natural Science Foundation of China(Grant Nos.11703033,11673051,11603001 and U1831136)the West Light Foundation of the Chinese Academy of Sciences(XAB2016A06)supported by the 100 Talents Project of the Chinese Academy of Sciences(CAS)。
文摘In order to measure the Universal Time(UT1)in real time,National Time Service Center(NTSC)has built a VGOS-like(VLBI Global Observing System)broadband VLBI network,which includes three13-m radio telescopes located in Jilin,Sanya and Kashi,and a data analysis center in Xi’an.Each station is equipped with a highly stable hydrogen atomic clock and a self-developed VLBI backend,and is colocated with two GPS receivers.This VGOS-like VLBI network may play an important role in improving the Chinese broadband VLBI technology and making valuable contributions to domestic VLBI measurements of UT1.In this paper,we introduce the specifications of this VLBI network,and present the UT1 measurements at C-band conducted in 2018 using the Jilin-Kashi baseline of this network.The comparisons between our UT1 estimates and those provided by IERS suggest that the NTSC VLBI network is capable to determine UT1 accurate at the level of 58.8μs.
文摘As an emerging technology to promote the combination of medicine and industry,the three-dimensional(3D)printing has developed rapidly in the fields of orthopedics,while its unique advantages in improving precise treatment still need to be further popularized.In this report,our team have exhibited several classic cases of integrating 3D printing into orthopedic clinical application,thereby further elaborating thoughts and opinions on the significance of 3D printing in the orthopedic clinical application,technical advantages,existing main problems and coping strategies.
基金supported by the National Natural Science Foundation of China (No.52074330,No.52288101)。
文摘As drilling wells continue to move into deep ultra-deep layers,the requirements for temperature resistance of drilling fluid treatments are getting higher and higher.Among them,blocking agent,as one of the key treatment agents,has also become a hot spot of research.In this study,a high temperature resistant strong adsorption rigid blocking agent(QW-1)was prepared using KH570 modified silica,acrylamide(AM)and allyltrimethylammonium chloride(TMAAC).QW-1 has good thermal stability,average particle size of 1.46μm,water contact angle of 10.5.,has a strong hydrophilicity,can be well dispersed in water.The experimental results showed that when 2 wt%QW-1 was added to recipe A(4 wt%bentonite slurry+0.5 wt%DSP-1(filtration loss depressant)),the API filtration loss decreased from 7.8to 6.4 m L.After aging at 240.C,the API loss of filtration was reduced from 21 to 14 m L,which has certain performance of high temperature loss of filtration.At the same time,it is effective in sealing 80-100mesh and 100-120 mesh sand beds as well as 3 and 5μm ceramic sand discs.Under the same conditions,the blocking performance was superior to silica(5μm)and calcium carbonate(2.6μm).In addition,the mechanism of action of QW-1 was further investigated.The results show that QW-1 with amide and quaternary ammonium groups on the molecular chain can be adsorbed onto the surface of clay particles through hydrogen bonding and electrostatic interaction to form a dense blocking layer,thus preventing further intrusion of drilling fluid into the formation.
基金supported by the National Natural Science Foundation of China(No.82071709,No.32070850,and No.82171601)the National Key Research and Developmental Program of China(2022YFC2702601 and 2022YFA0806303)the Joint Fund for New Medicine of USTC(YD9100002034).
文摘Male infertility is a worldwide health issue,affecting 8%–12%of the global population.Oligoasthenoteratozoospermia(OAT)represents a severe type of male infertility,characterized by reduced sperm count and motility and an increased frequency of sperm with aberrant morphology.Using whole-exome sequencing,this study identified a novel missense mutation(c.848C>A,p.A283E)in the coiled-coil domain-containing 34 gene(CCDC34)in a consanguineous Pakistani family.This rare mutation was predicted to be deleterious and to affect the protein stability.Hematoxylin and eosin staining of spermatozoa from the patient with OAT revealed multiple morphological abnormalities of the flagella and transmission electron microscopy indicated axonemal ultrastructural defects with a lack of outer dynein arms.These findings indicated that CCDC34 plays a role in maintaining the axonemal ultrastructure and the assembly or stability of the outer dynein arms,thus expanding the phenotypic spectrum of CCDC34 missense mutations.
基金sponsored by the MOST (Grant No.2017YFA0402701)the NSFC (Grant Nos.11873019, 11673066 and 11503033)+4 种基金the CAS (Grant No.QYZDJ-SSW-SLH047)the Youth Innovation Promotion Association of CASsupported by the Key Laboratory for Radio Astronomy, CASthe Open Project Program of the Key Laboratory of FAST, NAOC, CASFunding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement
文摘The morphology and kinematics of the spiral structure of the Milky Way are long-standing problems in astrophysics.In this review we firstly summarize various methods with different tracers used to solve this puzzle.The astrometry of Galactic sources is gradually alleviating this difficult situation caused mainly by large distance uncertainties, as we can currently obtain accurate parallaxes(a few μas) and proper motions(≈1 km s-1) by using Very Long Baseline Interferometry(VLBI).On the other hand, the Gaia mission is providing the largest, uniform sample of parallaxes for O-type stars in the entire Milky Way.Based upon the VLBI maser and Gaia O-star parallax measurements, nearby spiral structures of the Perseus, Local, Sagittarius and Scutum Arms are determined in unprecedented detail.Meanwhile, we estimate fundamental Galactic parameters of the distance to the Galactic center,R0, to be 8.35 ± 0.18 kpc, and circular rotation speed at the Sun, Θ0, to be 240±10 km s-1.We found kinematic differences between O stars and interstellar masers: the O stars, on average, rotate faster,>8 km s-1than maser-traced high-mass star forming regions.
基金This study was supported by the grants from the National"863"Program(No.2001AA2160313)Beijing Important Program Fund of Science and Technology(No.H020220010490)Capital Medical Development Fund of Science and Technology(No.2003-3002)
文摘The action potential of pacemaker cells in the sino-atrial node forms the automatic rhythm of the heart. The automatic depolarization in phase 4 is me DaSlS of the automaticity in pacemaker cells. Many currents are included in phase 4, such as calcium current, TTX-sensitive sodium current, sustained inward current （Isi）, decay of delayed rectifier potassium current, etc. Funny current （If） has long been recognized as important in this phase and is activated at hyperpolarized potentials during cell diastole and in turn activates other currents to form automatic depolarization.
基金CTSA Award from the National Center for Advancing Translational Sciences to the Vanderbilt Institute for Clinical and Translational Research,No.UL1 TR002243A Pilot and Feasibility Award from the NIDDK to the Vanderbilt Diabetes Research and Training Center,No.DK020593a VA MERIT Award,No.BX004845.
文摘Brain diseases affect 1 in 6 people worldwide.These diseases range from acute neurological conditions such as stroke to chronic neurodegenerative disorders such as Alzheimer’s disease.Recent advancements in tissue-engineered brain disease models have overcome many of the different shortcomings associated with the various animal models,tissue culture models,and epidemiologic patient data that are commonly used to study brain disease.One innovative method by which to model human neurological disease is via the directed differentiation of human pluripotent stem cells(hPSCs)to neural lineages including neurons,astrocytes,and oligodendrocytes.Three-dimensional models such as brain organoids have also been derived from hPSCs,offering more physiological relevance due to their incorporation of various cell types.As such,brain organoids can better model the pathophysiology of neural diseases observed in patients.In this review,we will emphasize recent developments in hPSC-based tissue culture models of neurological disorders and how they are being used to create neural disease models.
基金Supported by Jiangsu Elderly Health Research Project,No.LD2021010Jiangsu Elderly Health Research Project,Key Project of Elderly Health Research Project,No.LKZ2022010Open Project of National Key Professional Base for Standardized Training of Resident Physicians in Zhongda Hospital Affiliated to Southeast University,No.ZDZYJD-QK-2022-7.
文摘BACKGROUND The prevalence of osteoporosis and low bone mass is steadily rising each year.Low body weight is commonly linked to diminished bone mass and serves as a robust predictor of osteoporosis.Nonetheless,the connection between body mass index(BMI),bone mineral density,and lipid profiles among the elderly remains elusive.AIM To examine the association between BMI and bone mass,explore the correlation between lipid profiles and bone mass,and delve into the interplay between lipid metabolism and bone health.METHODS The study included 520 patients aged≥65 years(178 men and 342 women).Age,sex,weight,and height were recorded.Femoral neck bone mineral density and T scores were determined using a dual-energy X-ray absorptiometry scanner.Blood calcium(Ca),phosphorus(P),albumin(ALB),alkaline phosphatase(ALP),aspartate aminotransferase,alanine aminotransferase,triglyceride(TG),total cholesterol(TC),high-density lipoprotein(HDL)and low-density lipoprotein(LDL)levels were measured.Patients were classified by sex(male and female),age(65-79 years and≥80 years),and T score(normal bone mineral density,osteopenia and osteoporosis).RESULTS Age,sex,BMI,and ALP and TG levels were independent risk factors for osteoporosis.For the 65-79-and≥80-yearold groups,females presented lower T scores than males.Ca,P,ALB,ALP,TC,HDL and LDL levels were significantly different between men and women in the 65-79-year-old group.In addition,BMI and TG levels were significantly decreased in osteoporotic patients compared with patients with normal bone mass.TC levels declined in 65-to 79-year-old male and female osteoporosis patients.In the group of women aged≥80 years,osteoporotic patients showed significantly increased ALP levels.Furthermore,we found positive correlations between BMI and TG levels in the male and female patient groups.However,we found no significant differences in ALB,Ca,P,HDL and LDL levels in osteoporotic patients compared to patients with normal bone mass.CONCLUSION Osteoporotic patients showed significantly decreased
基金Project(035703011) supported by the Scientific Research Double Support Program of SICAU,China
文摘In order to explore a novel and potential method using carbon nanotubes （CNTs） for controlling blue-green algal blooms efficiently in future, effects of single-walled carbon nanotubes （SWCNTs） on Microcystis aeruginosa growth control were investigated under lab cultured conditions. Related physiological changes were tested involving several important enzyme of antioxidant defense system （superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT）, malondiadehyde （MDA）, photosynthetic pigments, protein, soluble sugar and extracellular microcystin toxins （MC-LR））. Algal cell density was significantly inhibited by SWCNTs at high concentration （〉5.00 mg/L）, and the inhibition rate was dose-dependent. For treatment with 100 mg/L SWCNTs, the inhibitory rates even reached above 90%. 96 h IC50 was determined as 22 mg/L. Antioxidant enzyme activities were dramatically dropped with increasing lipid peroxidation at higher SWCNTs concentration, indicating intracellular generation of reactive oxygen species （ROS） and oxidative stress damage in algae. Reduction of photosynthetic pigments, soluble sugar and protein contents suggested that SWCNTs may severely ruin algal photosynthesis system, destroy the metabolism-related structure of cell, and thus lead to negative physiological status in M. aeruginosa. Besides, SWCNTs can effectively decrease the amount of extracellular microcystins in culture medium.
基金Supported by the National Key R&D Program of China under Grant No 2016YFA0300804the National Natural Science Foundation of China under Grant Nos 51502007 and 51672007+2 种基金the National Equipment Program of China under Grant No ZDYZ2015-1the National Program for Thousand Young Talents of Chinathe ‘2011 Program’ Peking-Tsinghua-IOP Collaborative Innovation Center of Quantum Matter
文摘Recent advances in monochromatic aberration corrected electron microscopy make it possible to detect the lattice vibrations with both high-energy resolution and high spatial resolution. Here, we use sub-10 meV electron energy loss spectroscopy to investigate the local vibrational properties of the SiO_2/Si surface and interface. The energy of the surface mode is thickness dependent, showing a blue shift as z-thickness(parallel to the fast electron beam)of SiO_2 film increases, while the energy of the bulk mode and the interface mode keeps constant. The intensity of the surface mode is well-described by a Bessel function of the second kind. The mechanism of the observed spatially dependent vibrational behavior is discussed and compared with dielectric response theory analysis. Our nanometer scale measurements provide useful information on the bonding conditions at the surface and interface.
基金This work was supported by the National Natural Science Foundation of China(No.32070850)the National Natural Science Foundation of China(No.31630050,31890780,and 32061143006)+2 种基金the National Key Research and Developmental Program of China(2018YFC1003900,2019YFA0802600,and 2016YFC1000600)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB19000000)the Fundamental Research Funds for the Central Universities(No.YD2070002006).
文摘Multiple morphological abnormalities of the sperm flagella(MMAF)is a specific type of asthenoteratozoospermia,presenting with multiple morphological anomalies in spermatozoa,such as absent,bent,coiled,short,or irregular caliber flagella.Previous genetic studies revealed pathogenic mutations in genes encoding cilia and flagella-associated proteins(CFAPs;e.g.,CFAP43,CFAP44,CFAP65,CFAP69,CFAP70,and CFAP251)responsible for the MMAF phenotype in infertile men from different ethnic groups.However,none of them have been identified in infertile Pakistani males with MMAF.In the current study,two Pakistani families with MMAF patients were recruited.Whole-exome sequencing(WES)of patients and their parents was performed.WES analysis reflected novel biallelic loss-of-function mutations in CFAP43 in both families(Family 1:ENST00000357060.3,p.Arg300Lysfs*22 and p.Thr526Serfs*43 in a compound heterozygous state;Family 2:ENST00000357060.3,p.Thr526Serfs*43 in a homozygous state).Sanger sequencing further confirmed that these mutations were segregated recessively in the families with the MMAF phenotype.Semiquantitative reverse-transcriptase polymerase chain reaction(qRT-PCR)was carried out to detect the effect of the mutation on mRNA of the affected gene.Previous research demonstrated that biallelic loss-of-function mutations in CFAP43 accounted for the majority of all CFAP43-mutant MMAF patients.To the best of our knowledge,this is the first study to report CFAP43 biallelic loss-of-function mutations in a Pakistani population with the MMAF phenotype.This study will help researchers and clinicians to understand the genetic etiology of MMAF better.
文摘Background： Since the 1980s, severity of illness scoring systems has gained increasing popularity in Intensive Care Units （ICUs）. Physicians used them for predicting mortality and assessing illness severity in clinical trials. The objective of this study was to assess the performance of Simplified Acute Physiology Score 3 （SAPS 3） and its customized equation for Australasia （Australasia SAPS 3, SAPS 3 [AUS]） in predicting clinical prognosis and hospital mortality in emergency ICU （EICU）. Methods： A retrospective analysis of the EICU including 463 patients was conducted between January 2013 and December 2015 in the EICU of Peking University Third Hospital. The worst physiological data of enrolled patients were collected within 24 h after admission to calculate SAPS 3 score and predicted mortality by regression equation. Discrimination between survivals and deaths was assessed by the area under the receiver operator characteristic curve （AUC）. Calibration was evaluated by Hosmer-Lemeshow goodness-of fit test through calculating the ratio of observed-to-expected numbers of deaths which is known as the standardized mortality ratio （SMR）. Results： A total of 463 patients were enrolled in the study, and the observed hospital mortality was 26.1% （121/463）. The patients enrolled were divided into survivors and nonsurvivors. Age, SAPS 3 score, Acute Physiology and Chronic Health Evaluation Score 11 （APACHE 11）, and predicted mortality were significantly higher in nonsurvivors than survivors （P 〈 0.05 or P 〈 0.01 ）. The AUC （95% confidence intervals [C/s]） for SAPS 3 score was 0.836 （0.796-0.876）. The maximum of Youden＇s index, cutoff, sensitivity, and specificity of SAPS 3 score were 0.526%, 70.5 points, 66.9%, and 85.7%, respectively. The Hosmer-Lemeshow goodness-of-fit test for SAPS 3 demonstrated a Chi-square test score of 10.25, P = 0.33, SMR （95% CI） = 0.63 （0.52 0.76）. The Hosmer-Lemeshow goodness-of fit test tbr SAPS 3 （AUS） demonstrated a Chi-squa
基金Supported by the National Natural Science Foundation of China(No.20772048)
文摘Two new polyhydroxysteroids, 12β,16β,20-trihydroxycholesta-1,4-dien-3-one 16-acetate（1） and 24- methyl-12β,16β,20-trihydroxycholesta-1,4-dien-3-one（2） were isolated from octocoral Sinularia sp. Their structures were elucidated primarily on the basis of 1D and 2D NMR and the mass spectroscopic studies. The cytotoxicity of these compounds against three tumor cell lines was also reported.
基金financially supported by the National Natural Science Foundation of China (Nos. 21374088 and 21674086)the Fundamental Research Funds for the Central Universities (Nos. 3102017jc03006 and 3102017jc01001)
文摘Ordered porous block copolymer films（PBCFs） have attracted much attention because of their potential applications in several fields. In this paper, we first reported a non-destructive, controllable, and efficient approach for preparation of β-cyclodextrin（β-CD）-functionalized PBCFs（β-CD-PBCFs）. The key point of the approach is to incorporate β-CD units into the hydrophilic segment of amphiphilic block copolymers before the preparation of films. β-CD-PBCFs with structural integrity and controllable pore parameters were fabricated through combining of self-assembly and breath figure methods. And then, the effective adsorption capacity of β-CD-PBCFs toward Congo red was confirmed through UV-Vis spectroscopy and was found to be affected by β-CD content and solution p H values. Adsorption kinetic results showed that the adsorption behavior of β-CD-PBCFs was consistent with the pseudo-second-order kinetic model and the chemisorption mechanism.
文摘Lower hybrid current drive(LHCD)experiments have been done on the superconducting Tokamak HT-7 by using a new developed long pulse megawatt lower hybrid wave system.An LHCD efficiency of 0.5×10^(19)A·m^(-2)/W in a pulse length of several hundreds of milliseconds has been achieved.After boronization of the tokamak vacuum vessel,considerable improvements of plasma energy confinement and particle confinement during LHCD phase have been achieved by adjusting wave spectra.An energy transfer from the lower hybrid wave to plasma bulk electrons has been demonstrated experimentally.A computer simulation of the LHCD experiments by using a ray tracing code combined with a two dimensional Fokker-Planck code is in good accordance with experimental measurements and suggests an important role of plasma current profile.
